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SmartCopter

Matthew Campbell

Brian Williams

Alvilda Rolle

Group # 3

Senior Design

University of Central Florida

Sponsors:

Nelson Engineering Co.

Rogers, Lovelock, and Fritz Architecture

August 10, 2009

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Table Of Contents

Executive Summary 1

Chapter 1: Introduction 2

1.1. Project Narrative 2

1.2. Team Members/Sponsors 3

Chapter 2: Helicopter Description 4

Chapter 3: General Design 14

3.1. Detailed Project Description 14

Chapter 4: Subsystem Design 16

4.1. Chapter 4 Overview 16

4.1.1. Description 16

4.1.2. Objectives 17

4.2. Copter Stability System 18

4.2.1. Hardware 18

4.2.1.1. Power Management 18

4.2.1.1.1. Battery 18

4.2.1.1.2. Power Supply 19

4.2.1.1.3. Motor Control 20

4.2.1.2. Flight Surface Control 22

4.2.1.2.1. Servos 22

4.2.1.2.2. Accelerometers 24

4.2.1.2.3. Gyros 27

4.2.1.2.4. Ultrasonic Range Finder 29

4.2.1.3. Noise Filtering 30

4.2.1.4. Global Positioning System (GPS) 33

4.2.1.5. Microcontroller 35

4.2.2. Software 42

Chapter 5: Testing Procedures 47

5.1. Helicopter Flight 47

5.2. Hardware Connections 50

5.3. Ultrasonic Range Finder 52

5.4. Gyroscope 53

5.5. Accelerometer 53

5.6. SiRF Star III Chipset 54

5.7. HeliCam 55

5.8. SD Card Interface 55

5.9. Fully Integrated System 57

5.10. Testing Accommodations 59

5.11. Detailed Plan 62

5.12. Testing Locations 64

Chapter 6: Mounting Hardware 67

Chapter 7: Future Project Upgrade Possibilities 69

7.1. Potential Uses 69

7.2. Multi-Helicopter Coordination 70

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Chapter 8: Timeline 71

Chapter 9: Budget 73

9.1. Parts List 73

9.2. Funding 77

Chapter 10: Conclusion 78

Chapter 11: Appendix 79

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Executive Summary

Our project SmartCopter revolves around the design and production of a black box type

device. Attached to the bottom of an RC helicopter the device will record flight data to be

viewed later. The flight data will include position obtained from GPS and altitude. Also

included will be data regarding forces acting on the craft such as acceleration in the X,Y

and Z axis, as well as rotation such as pitch and roll. This data will then be saved to an

SD card where it can be viewed later using base station software. Once at the base station

this data will be analyzed graphically to provide a picture of the forces involved in the

flight. All the while the SmartCopter will broadcast video to a base station where it will

be recorded and later synced with the data. Thus aiding in analyzing the data recorded

earlier.

Along with functionality, our design needs to be conceptually viable as well. Our system

must meet a few requirements for this to occur. One such requirement is the need for

reliability. Our system must successfully complete the mission every time it is sent out.

A major aspect of its reliability will be the durability of the system. SmartCopter must be

capable of withstanding forces incurred during landing, whether it be in full control or

not, and still maintain its ability for a repeat use. Another issue facing our SmartCopter is

weight. As with any aerial vehicle, weight is extremely critical. Therefore the design

will incorporate the lightest possible components that will be necessary for the system to

take off, and land safely. Since components will be physically added to the helicopter,

placement of these additional components inside the shell of the helicopter is crucial.

Even distribution of the additional weight is necessary to maintain the balance integrity

of the helicopter.

Some other factors that will need to be addressed, but that aren‟t as crucial, will be

SmartCopter‟s ease of use, flight range, as well as the price. SmartCopter‟s user input

system needs to be as user friendly as possible. Along with user feasibility will be the

range of SmartCopter. The team will establish the range of the helicopter. Another issue

that will need to be addressed will be the cost of entire project. SmartCopter needs to be

moderately inexpensive within a total cost of $1000. Funding of up to $1000 will be

provided by SmartCopter‟s sponsors, with any additional costs being incurred by the

team members. Therefore it is of utmost importance to minimize the total cost of the

project.

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Chapter 1: Introduction

1.1 Project Narrative

1.1.1 [18] History:

In 1939 one of the earliest flight data recorders was created by François Hussenot in

France and was called the „type HB‟ flight recorder. It was created to measure altitude,

speed, and various other attributes attributed with flight. He managed to do this by using

88mm photographic film that was shown upon by a thin ray of light. This light was

controlled using mirrors that reflected the light based on the values from the sensors.

Since then flight recorders have been an integral part of aviation.The major driving force

behind the development of flight recorders stemmed from the need to investigate crashes

where witnesses were not available. This was the case in 1953 when a series of crashes

involving passenger aircraft led to an investigation of the cause. Without any witness the

need for a data recorder became evident and development began on a cockpit voice

recorder as well as a flight data recorder.

However it wasn‟t till 1960 that the idea of a „black box‟ data recorder caught on with

industry. This was largely due to budget issues and the primitive technology. In a few

years with increasing scrutiny from governments concerned about airline accidents the

black box data recorder was accept and installed on commercial jets. Today modern black

boxes have evolved into hardened capsules capable of withstanding intense shock, heat,

and water. Designed to withstand even the worst crashes the data recorded on these boxes

are vital to crash investigations and will be a part of air travel for as long as it exists.

1.1.2 Motivation

The motivation behind our project is to create a black box device to study the forces

involved with RC helicopter flight. With this knowledge we hope to understand how

changes in flight surfaces affect the overall flight characteristics. This could then be used

as a stepping stone to create an autonomous control system for the helicopter. By

analyzing the sensor data we can create assumptions as to how to control the craft.

One other reason for developing the black box is similar to the reason black boxes is

installed on full sized aircraft, to investigate accidents. With information about why the

craft crashed we can use that information to prevent future accidents. Also by studying

the forces involved we can try to understand the tolerances of certain components and

where structural integrity needs to be increased. Not only that but by recording the flight

data user error can be detected and corrected helping train rookie pilots in the operation

of the craft.

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1.2 Team Members/Sponsors

The team that has taken on this daunting task of creating SmartCopter consists of

Matthew Campbell, Brian Williams, and Alvilda Rolle. All three team members are

currently in their senior years at the University of Central Florida, in Orlando, Florida.

Matthew Campbell is a native Floridian who has had an great interest in computer

science ever for as long as he can remember. Matthew has also held interest in learning

various related electrical engineering applications. He is seeking a Bachelor of Science

in the field of Computer Engineering and has a minor in business.

Brian Williams has lived in the central Florida area for about 12 years. Brian‟s father

served in the United States Air Force for a total of 20 years before retiring. Due to his

father serving in the military, Brian‟s family has traveled extensively abroad. He has

lived at various Air Force bases throughout the United States and Germany. A majority

of his life was spent living on major Air Force installations that have a history of

extensive aerial technological advancements. A few of these installations include Wright

Patterson Air Force Base in Dayton, Ohio, Ramstein Air Force Base in Ramstein,

Germany, and Whiteman Air Force Base in Whiteman, Missouri, which was a secret

location of the SR-71 Blackbird and the stealth B-2 Bomber. As a child growing up in a

military environment, Brian has witnessed various sorts of air craft in action displaying

their amazing design and technology. However at the same time, he has witnessed the

devastation that can happen when things malfunction and go aria. Brian and his family

were at the famous air show in Ramstein, Germany on August 28, 1988 where two

airplanes collided mid-air, then came crashing to the ground. Brian‟s family were among

the spectators enjoying the amazing displays of aerial navigation. They happened to be

watching the show at the exact location where the fiery wreckage came crashing down. It

was the simple good fortune of being thirsty which drew his family away from the site a

mere 5 minutes prior to the crash. It was a collaboration of all his experiences growing

up as a military child which sparked Brian‟s interest in aerial aviation and in engineering

in general. Brian is seeking his Bachelor of Science in the field of Electrical

Engineering.

Alvilda (Allie) Rolle is a native Floridian. Her interest in electronics was inspired by her

father‟s knowledge of computers and printers. She would watch her father as he built

bare bone computers and repaired Hewlett Packard printers. From her father she

developed a love for computers and electronics. She initially wanted to pursue a

bachelor‟s degree in Spanish, but she changed her mind, and instead pursued Computer

Engineering. After a series of programming courses, she realized that she preferred

Electrical Engineering. She changed majors the next semester. Allie enjoys studying

languages. She is currently pursuing a minor in Spanish, and has become quite fluent in

it. She also enjoys traveling as often as she can. Allie has family members who have

helped solidify her interest in Electrical Engineering. She enjoys conversing with them

about technological advancements. After graduation Allie hopes to obtain a job in the

field of engineering. She eventually intends to attend graduate school in the possible

pursuit of law or architecture. In which both fields she can apply her electrical degree.

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Along with these dedicated team members, project SmartCopter has enlisted the

sponsorship of two prestigious engineering firms. The firms consist of Nelson

Engineering Co. of Merritt Island, Florida and Rogers, Lovelock, and Fritz Architecture

and Engineering (RLF) of Winter Park, Florida. Nelson Engineering Co. is an

engineering firm which was established in the early 1990‟s. They specialize in various

sorts of engineering practices including Aerospace, Electrical, Mechanical, Civil,

Chemical, Industrial, Environmental, and Fire Protection Engineering. Nelson

Engineering Co. focuses a great deal of resources on product research and development,

with extensive work done with NASA and the United States Air Force.

The other sponsor for the SmartCopter project is Rogers, Lovelock, and Fritz

Architecture and Engineering (RLF). RLF is an Architecture, Planning, Engineering, and

Interior Design firm, and the employer of team member Brian Williams. RLF was

established in 1935 by James Gamble Rogers II. RLF has done extensive design

including various religious, healthcare, educational, and Department of Defense projects.

RLF is a naturally recognized firm that has received a number of awards for their design

work, as well as their various volunteer efforts. RLF is one of the oldest practicing

design firms located between Jacksonville and Miami. This is due in part to its

exceptional staff, and its long roots in the Central Florida community.

Chapter 2: Helicopter Description

The helicopter is the focal point of our project, therefore selecting the right RC helicopter

to meet our requirements was vital. Originally we considered smaller RC helicopters with

two counter rotating main rotors such as the one shown in Figure 2.1. Their ease of

control and inherent stability was appealing at first. However after researching further we

found that with the dual rotor configuration forward flight against wind was slow to

impossible, so it did not meet our requirements.

[9]Figure 2.1

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From there our research led us to more traditional RC helicopters with a single main rotor

and a tail rotor to balance the main rotors torque. The single rotor helicopter would be

more difficult to control than the counter rotating rotor helicopter but would fare much

better in windy conditions. Therefore to meet our wind requirements we chose this layout

for our helicopter.

The next decision we had to make was on the design of the tail rotor system. Many RC

helicopters use a small electric motor that is completely separate from the main rotor

drive. While this design does have some advantages, such as being easier to manufacture,

there are also some drawbacks. For example, tail rotor motors are prone to failure and are

less precise in their thrust generation. We decided that for the best control of our

helicopter we would choose a helicopter with tail rotor driven by the main rotor‟s motor

and the pitch of the blades will change the amount of thrust generated.

With the fundamental design of our helicopter chosen we could start talking about the

actual flight dynamics of they helicopter. Along with motion in the X, Y and Z axis we

must also consider pitch, roll, and yaw also known as Tait–Bryan angles or Euler angles

shown in Figure 2.2. Pitch corresponds to rotation about the y-axis and will be defined as

θ; yaw corresponds to rotation about the z-axis and will be defined as ψ; roll corresponds

to rotation about the x-axis and will be defined as φ.

Figure 2.2

In order to rotate or move the helicopter the flight surfaces on the main rotor and the tail

rotor change their pitch to create an unequal force producing the desired motion. The

cyclic control, which is similar to the flight stick in an airplane, is used to control the

pitch and roll of the helicopter by varying the pitch of the main rotor blade. The yaw rate

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and heading is controlled by the pitch of the tail rotor. Finally motor RPM and collective

pitch, the overall angle of attack, of the main rotor blades control the lift generated and

altitude of the helicopter.

By combining these different changes to the control surfaces we can create a wide variety

for our helicopter. For example pitching the nose downward and increasing the

throttle/collective will propel our helicopter forward while maintaining altitude.

Due to the size and relatively low weight the helicopter is very sensitive to control inputs

and any air flow disturbances are magnified, creating a very high bandwidth system.

Unstable air just below the main rotor, called rotor wash, affects lift on all of the flight

surfaces and becomes more unstable after passing past the fuselage of the helicopter. This

problem becomes magnified at ground level and causes problems at take-off and landing

so accurate data collection during this time is critical to understanding the flight of the

helicopter.

The first series of measurements we will take of the helicopter will be while it is in a

hovering mode. In this mode the helicopter maintains its current altitude and position,

making corrections for any disturbance introduced to the system. In order to maintain the

altitude we balance the lift generated by the main rotor and the gravitational force.

To maintain the heading we balance the torque generated by the main rotor and the force

generated by the tail rotor, using the same equation for lift as before. Finally the

helicopter must balance the pitch and roll in order to maintain its position. This is made

more complicated due to the fact that the spinning main rotor blade provides gyroscopic

precision which causes a phase lag in the system, which should evident when analyzing

the data received from the helicopter.

In order to simplify the modeling process we will break up the model relating inputs to

helicopter position into three parts shown in Figure 2.3 and study each block in depth.

The first block will model the flapping dynamics of the rotors and relate the control

inputs to the thrust generated by the rotors as well as the orientation of the main rotor

related to the body of the craft. This will then drive the inputs for the force torque

equations in the second block which will output the sum of the forces and torques on the

helicopter. Finally the last block will model the helicopter as a rigid body and define the

position and orientation of the helicopter.

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Figure 2.3

The first block that we‟ll look at in depth is the one containing the rigid body equations.

In order to transform the force vectors stated in the frame of reference of the body of the

helicopter to the spatial frame we define the center of gravity in we need to derive a

coefficient matrix. These rotation matrices are defined by Bak[4]

and are shown below in

equations 2.a. Where θ1 is the roll angle, θ2 is the pitch angle, and θ3 is the yaw angle. By

combining these equations we can relate the spatial frame of reference to the body frame

of reference as shown also in equations 2.a. Alternatively by taking the inverse we can

relate the body frame to the spatial frame.

Equations 2.a[4]

Now that we have the angles to define the orientation of our helicopter we can look at the

time derivative of these angles, called Euler rates which will represented by . We can

also represent these values as an angular velocity vector represented by ω. The value of ω

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can be calculated with equations again provided by Bak[4]

shown in equations 2.b, and the

same can be said for the inverse also shown.

Equations 2.b[4]

We now need to define the angular acceleration of our helicopter as it relates to torque

put on the rigid body of our helicopter. First we‟ll define an inertia matrix I such that we

can find the value of the angular momentum vector H. The relation as well as the inertia

matrix is defined below in equations 2.c provided by Wie[5]

.

Equations 2.c[5]

This combined with the equations for torque of a rigid body about its center of gravity

shown in equations 2.d gives us a final relation between the torque vector, written as τ or

, and the angular velocity vector shown also in equations 2.d provided by Wie[5]

.

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Equations 2.d[5]

Describing the translatory acceleration only involves one equation where F, the force

vector applied to the helicopter, is related to V, the velocity vector of the helicopter, as

shown in equations 2.e below.

Equations 2.e

With our rigid body block defined we can move on and look at the second block, the

force and torque equations. There are three main forces acting on the helicopter: FMR

which is the force generated by the main rotor, FTR which is force generated by the tail

rotor, and finally the force of gravity is taken in to account represented by FG.

The force of the main rotor is a function of the thrust generated along with the orientation

of the plane of the main rotor‟s blades, B1c and B1s. This is shown in Figure 2.4[6]

where

HP is the initial plane and TPP is the pitched plane. From this we can derive force

equations for each axis shown in equations 2.f below.

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Figure 2.4[6]

(Top B1C; Bottom B1S)

Equations 2.f

The next force we look at is the one created by the tail rotor. Since there is no pitch

involved, the tail rotor‟s force is equal to the thrust created by the tail rotor in the positive

y direction.

Finally we have the gravitational force acting on our helicopter. We can represent this as

a vector by considering our Euler angles from before. This is shown in equations 2.g

below derived from equations 2.a.

Equations 2.g

Combining all terms we come up with the following force vector matrix shown by

equations 2.h.

Equations 2.h

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Similarly we will define torque vector by breaking it up into three components shown in

equations 2.i, torque generated by the main rotor, torque provided by the tail rotor, and

finally torque generated by the resistive air drag on the main rotor.

Equations 2.i

The first of which, the torque generated by main rotor, is shown in the equations 2.j

below where h is the distance from the COG to the main rotor along the z-axis, l is the

distance from the COG to the main rotor along the x-axis, and y is the distance from the

COG to the main rotor along the y-axis.

Equations 2.j

Next the torque generated by the tail rotor is considered. Using the same nomenclature

for distance used for the main rotor we can derive equations 2.k similar to the one just

shown.

Equations 2.k

Last we need to calculate the torque created by the aerodynamic drag of the main rotor.

However accurately modeling the drag on the main rotor can be a very complex problem

so we will use a model as described by Koo et al. [8] shown in equations 2.l below.

Where Qi is the drag created, Di describes the drag created when blade pitch is zero, and

Ci describes the relation between drag and thrust generated. Taking into account the pitch

of the main rotor blades we can complete the torque matrix also shown in equations 2.l.

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Equations 2.l

Combining all of our torque equations and inserting them into equation 2.i we have our

torque matrix for all our components shown below in equations 2.m.

Equations 2.m

The final block we‟ll take a look at is the block containing the flapping dynamics for the

main rotor and tail rotor, specifically how much thrust is created. The equation for the

thrust generated by the main rotor according to NASA‟s Minimum-Complexity

Helicopter Simulation Math Model is shown in equations 2.n[3]

where ρ is the density of

air which will remain constant throughout the flight. The rotor‟s angular rate will be

defined as Ω, R will be defined as the radius of the blade, and B will be the number of

blades. The lift curve slope is a constant and will be defined as a and c is the chord of the

blade. Finally wb is the velocity of the main rotor blade relative to the ambient air and vi

is the velocity of the flow through the plane of the blades and is derived below.

Equations 2.n[3]

By ignoring the blade twist, shown as θtwist, we can simplify the derivation of the wb

shown by equations 2.o[3]

.

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simplifies to

Equations 2.o

[3]

As you can see in equations 2.o that the thrust of the main rotor is merely a function of vi

and vi is a function of the main rotor thrust, meaning that these equations are recursively

defined. These values feed back into the equation after a certain amount of delay, 5

iterations is enough to ensure that the values have settled according to NASA‟s model [3]

.

Next we need to define the thrust produced by the tail rotor. In order to simplify this we

will assume that yaw will be controlled by the magnetic compass such that a single

heading is maintained.

We show how the tail rotor thrust is derived below in Equations 2.p. Solving for the tail

rotor force and adding in the force associated with the input force upedal we have our

equation for tail rotor thrust.

Equations 2.p

With all of this we have a general description of the flight characteristics of our

helicopter that we can compare our physical measurements to later in the project.

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Chapter 3: General Design

3.1 Detailed Project Description

SmartCopter began as a modified 6-channel RC helicopter designed to work

autonomously. The helicopter we chose, the Esky Belt-CP 450 has built in servos and

gyros. Its very light structure is built for 3D maneuvers. With this initial design our aim

for SmartCopter was to enhance its structure so that it could not only fly automatically

but also take surveillance videos, and sense unwanted objects to avoid collisions.

However due to time constraints, lack of professional flight training and other factors,

SmartCopter has emerged as a data logger. With the helicopter component a successful

SmartCopter mission would have begun by a successful upload of waypoints via

computer software. Once the aircraft was in automatic mode, it would begin its flight

sequence by launching from the start pad. It would check its GPS coordinates and

commence flight plan.

The design was modified instead to eliminate the autonomous part, but still use the sensor

readings as stored media within a data recording device. With the helicopter component

by using its x,y,z coordinates it would arrive at its destination by receiving the

longitudinal and latitudinal points through its GPS flight path. During its flight sequence

the screen would have displayed GPS coordinates for every point of the mission. There

would also have been a mini video recording the mission. The ultrasonic range finder

would have ensured that SmartCopter wasn‟t too close to the ground or other moving or

nonmoving objects. If a surface or object was detected a signal would have been sent to

the microcontroller which would then be sent to the gyro, so that the aircraft could adjust

its direction.

These design criteria will still be actively a part of the data logger but as generated values

being referenced by each sensor. They will not serve as control devices for the helicopter

except via test flying which consist of a person holding the helicopter and rotating a room

with it in order to generate those values. Time permitted training will be underwent to

adequately learn how to control the helicopter. Ideally as an autonomous device when

SmartCopter encounters objects it would pause during its flight sequence and hover,

while adjusting its tail to adjust to the infraction. In which case it would either move up,

down, backwards, left, or right to avoid a collision. The ultrasonic range finder would be

especially useful because during missions that may take place in a public area, there is

constant action. Once SmartCopter reached its waypoint destination the user would

receive a text message indicating the mission is complete. If the user was tracking the

flight progress via a computer then the screen would light up on SmartCopter and the

message would also show up on the computer device indicating a completed mission.

SmartCopter then would repeat the mission but to return to its starting position. The

video would still be in record mode.

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The data logger will have a similar display unit. It will have a user input LED in which

the user can select each device and see the data it‟s storing or the stored data. During an

autonomous mission the completed video can be removed and played or used for

additional purposes. The video will have efficient memory card space to record the entire

mission. If time permits the video component will be included in the data recording

device. If at any time SmartCopter encounters problems, the emergency override will

kick in. The user will be able to stop the data input in mid sequence. SmartCopter will

need the servos, gyros, accelerometers, and the electronic compass to control its flight

operations. The servos are used to correct any sudden movement that the gyro detects.

The servos will correct any negative feedback that is detected. The gyros will detect any

negative feedback that SmartCopter encounters. Together they ensure that SmartCopter is

not encountering any detrimental feedback that may cause serious damage, or that may

interfere with its direction. The gyro will ensure that SmartCopter is always pointed in

the desired direction because it detects unwanted movements of the tail, and corrects

them. With autonomous flight these sensors would each be used to maintain control of

the aircraft, however their values will be collected, stored and viewed by the user and

used for their own purpose. The electronic compass will no longer be necessary with the

updated design modifications.

The accelerometer will measure the direction of acceleration of SmartCopter. It will also

ensure that SmartCopter is oriented correctly. Additionally it will sense vibrations and

shock. This device will constantly monitor SmartCopter‟s velocity. It will be able to track

how fast it should be going, and whether it‟s traveling too fast.

Although the GPS function can measure direction, it is fairly inaccurate when the aircraft

is not in motion. But with the data logger it is less of importance to maintain constant

direction. The values are more important.

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Chapter 4: Subsystem Design

4.1 Chapter 4 Overview

4.1.1 Description

Chapter four is exclusively about the subsystem design of SmartCopter. It contains three

sections the Copter Stability System, the GPS Guidance System, and the Camera System.

The Copter Stability System begins with the hardware surfaces. It provides a conceptual

description for each component as well as practical applications for them. The Copter

Stability system contains three subsystems including Hardware, Software, and

Emergency Override. There are four subsections of Hardware, Power Management,

Flight Surface Control, Noise Filtering, and the Microcontroller.

Power Management addresses the battery specifics, the power distribution, and the motor

operations. It provides details of the battery chosen to power SmartCopter, the Lithium-

Polymer battery. It describes the various advantages of using this particular battery. Then

it addresses the importance of maintaining a balanced power system by not applying too

much voltage to the system. The final subsection in Hardware is the Motor Control

section. Here the brushless motor is examined. It‟s compared with its predecessor the

brushed motor, and it‟s improvement in efficiency than the brushed motor. The Power

Management section contains the power behind SmartCopter.

The Flight Surface Control section addresses the various components that are required to

maintain flight stability. Although the servos are of less concern for the data logger, they

are correction devices that correct the error feedback and maintain the angular position of

the shaft. The accelerometers are then discussed and detailed in great length. They are

devices which measure activity acceleration due to gravity. SmartCopter will operate

with piezo-electric accelerometer. This section also includes the gyros. The gyros are

used to monitor the direction of the head, and ensure it‟s directed in the correct direction.

It also addresses the two types of gyros, the heading hold and the yaw rate. The next

component addressed is the electronic compass. The final section in the Flight Surface

Control segment contains info on the ultrasonic range finder. This device is used to

measure the distance between moving and/or non moving objects.

The Noise Filtering subsection briefly describes the Low-pass, High-pass, and Band-pass

filters. SmartCopter will encounter induced noise interference. It‟s possible that it will

exist between the transmitter and the receiver, and other electronic components. These

filters are often used to attenuate unwanted noise feedback. The Microcontroller is the

base, where the components connect together. It‟s the inner computer within SmartCopter

that‟s designed for smaller applications such as this. This embedded system contains a

CPU (central processing unit), a clock generator, memory storage device (RAM), an

analog-to-digital converter, and other serial communication interfaces.

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The next subsection of the Copter Stability System is the Software department. Software

will need to be written for each flight operation, the take off, the landing, the hovering,

and the traveling in motion. Stabilizing SmartCopter will be a tremendous part of this

design. Once SmartCopter has been stabilized, then the above functions will be

programmed in order to enable for secure take off functionality. Each division of the

Software section is important to completing an operational flight mission. These

operations would have been necessary to maintain autonomous flight, however because a

flight sequence will possibly consist of one person circling a room, they are of less

importance. The second chapter of the Subsystem Design is the GPS Guidance System.

This section is divided into four parts: the User Waypoint Input, the Accuracy

Requirement, the Hardware, and the Software.

The User Waypoint Input section addresses how the user would input the desired

destination by inputting the corresponding waypoints. For SmartCopter to be as

operational as possible then it will need to be as accurate as possible. Error will be

present, but ideally the percentage of error will be desired to be as little as possible. There

is a Hardware section similar to the Copter Stability System. The Hardware section will

contain information and developmental procedures for the GPS, and the Electronic

Compass. It will address how both components will work independently but together to

maintain SmartCopter is always on course, providing some additional information from

the Copter Stability System chapter.

Both components of SmartCopter will need software development. Within the Software

division the Waypoint following will be described. The last subsection of the GPS

Guidance section is the Camera System. The technology behind the video system of

SmartCopter will be probed into. The section includes how the video recording

component will operate. Originally SmartCopter was to be designed with video

capabilities of recording the entire flight mission. However to design changes the data

logger will not include the video recording device. Each section and corresponding

subsections will be addressed in greater details in the upcoming chapters. It addresses the

role each component will play within SmartCopter‟s design.

4.1.2 Objectives

The objective of Chapter 4 is to provide in depth descriptions of the internal operations of

SmartCopter. The goal is to provide as much information about the inner hardware and

software of SmartCopter. Being a fairly new concept to some of the members, there was

a lot of research that needed to be done. There are related aircraft in the field now. When

SmartCopter is complete, it will be an automated helicopter. It‟s internal design will be

similar to the research provided in this chapter.

This chapter provides visuals to assist the user and the reader with the physical and

conceptual knowledge behind SmartCopter. It provides formulas so that the user and the

reader have a somewhat clear understanding of the conceptual concepts behind the

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operation of SmartCopter. The objective of this chapter is to also provide descriptions of

the operation of each component, and to provide information on how these components

will be implemented.

4.2 Copter Stability System

4.2.1 Hardware

4.2.1.1 Power Managment

4.2.1.1.1 Battery

The SmartCopter will be battery powered by a Lithium-Polymer (Li-Po) battery,

specifically the 11.1V 1800mAh 20C high capacitance Li-Po battery. The Li-Po is not

only cheaper than the Li-Ion, but is being used more frequently in cell phones, PDA‟s,

laptop computers, Radio-controlled aircraft, vehicles, and IPods. Some companies are

even considering using the Li-Po in future battery electric vehicles. The Li-Po is

undoubtedly light weight, cost effective, and due to the rechargeable capabilities offers an

increased run time, which will come in handy for SmartCopter missions.

For the purpose of this design we will use two Li-Po batteries. While one is in use the

other will recharge itself, and vice versa. For future use the design will need to be

adjusted, because the Li-Po cannot be exposed to too much heat. One of the future uses

was locating civilians in the midst of fire. The Li-Po also has some internal resistance

issues.

The internal resistance of a Li-Po or Li-Ion battery is relatively high in comparison to

other rechargeable chemistries. The increased terminal resistance is a time dependant

process. Once the internal resistance has increased it can often cause voltage drops at the

terminal, which then reduces the amount of maximum current being extracted from the

battery. Eventually the battery reaches a point in which it can no longer operate the

device for a period of time. All setbacks aside the Li-Po in comparison to the Li-Ion

maintains a greater life cycle reduction rate.

One main advantage for using Li-Po over Li-Ion is that aside from possible explosion if

over charged, unlike other batteries they can be thrown around, roughly handled, run over

by vehicles and still not suffer from explosion. If SmartCopter experiences unexpected

turbulence the Li-Po battery will not explode from sudden shifts in elevation or density.

How fast the battery can discharge is based upon the maximum current capacity. This

battery has a 20C capacity. It should discharge in 1/20 hours or three minutes. The

battery life according to one formula is approximately 5.4 minutes:

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1800mAh = 1.800Ah

20C = 20A supplied current

1.800Ah x 60min = 108

108/20A = 5.4 minutes

Li-Po batteries have voltage varies between approx. 4.23(charged) and 2.7(discharged).

The figure below is a photograph of a Li-Po battery provided by Wikipedia.

Lithium Polymer battery

4.2.1.1.2 Power Supply

The power system for RC helicopters consists of three elements, the battery, the speed

controller, and the motor that is responsible for driving the rotor blades and gearbox.

The battery power is important because each component that is added to SmartCopter

will need battery power. So in addition to powering the built-in components the

additional components will also require power, such as the electronic compass. Once

again SmartCopter will be battery operated by a rechargeable Li-Po battery. It‟s a

relatively new development, having replaced the Li-Ion battery. It‟s lighter and more

powerful, which is what SmartCopter needs. And its rechargeable capacity is excellent

because all we‟ll have to do is charge it up and resume flying. For the sake of time

limitations we hope to have two Li-Po batteries, so that while one is recharging, the other

can be in use.

SmartCopter without the design additions flies for approx 15 minutes. How all of the

design specifications will affect the time, is difficult to say. But by investing in a second

battery we can cut out some of the wait time in between test flights. There will still be a

wait time because the battery takes approximately 30 minutes to recharge, however with

the second battery SmartCopter can be in flight for 10-15 minutes of that charge time.

In RC helicopters the battery is the power source. The higher the battery, the more power

there is available. Within the helicopter, working with the motor is the electronic speed

controller. This c component interprets the control signals coming from the radio receiver

and transfers the battery power to the motor which then controls the speed the user wants.

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The electronic speed controller works as a buffer to fluctuate the speed of the brushless

motor. This function takes place between the motor and the battery.

The final component the motor, converts all electric power to mechanical power. With a

brushless motor the power cannot be applied directly to it, thus the speed controller

causes the motor to rotate by powering each phase of the brushless motor in succession.

SmartCopter gains efficiency from the brushless motor, because of its maintenance free

built, and its soundless structure. SmartCopter can prospectively stealthily hover behind a

person without being detected. For future use this feature will be highly invaluable. For

example for military uses an efficiently silent device will be more advantageous than a

noise filled design. Using the brushless motor affords this. Although it cost more, it‟s

more powerful than the brushed motor.

SmartCopter will need to maintain a balanced power system by not overloading each

individual component. As it is being built, more than likely we will encounter many

necessary adjustments that need to be addressed. Some of which may include applying

too much current or voltage, because if too little is applied then the device will not power

up. If too much is applied then something may burn out. The more power applied the

faster it may fly, but the shorter the battery life time.

4.2.1.1.3 Motor Control

The SmartCopter will be driven by an Esky 450 3800KV brushless motor. Thanks to

technology advancement the brushless motor has almost explicitly replaced the brushed

motor. The brushless DC motor (BLDC) consists of a set of electromagnetic motors on a

non rotating stator and a set of permanent magnets on a rotor. When it‟s connected to a

DC source, the electromagnets charge as the shaft turns. With these adjustments the

brush-system is eliminated and replaced by an electronic controller. The controller then

performs the same power distribution function as the brush-system except using a solid

state circuit.

With the brushed motor the electromagnets are located on the inside of the motor as part

of the armature. The armature rotates, hence being referred to as the rotor. The permanent

magnets are located on the outside, as stationary objects or the stator. Once electricity has

made contact with the electromagnet it creates a magnetic field inside the armature which

repels and attracts the magnets in the stator. The armature must spin through 180 degrees.

In order for it to maintain spinning, brushes are used to change the polarity of the

electromagnets.

Although the brushed motor was efficiently workable, the system was gravely in need of

upgradeable developments. All of which will help SmartCopter run as smoothly and as

efficiently as possible. The BLDC eliminates the use of brushes. Not only do brushes

limit the maximum possible speed of the motor but they also eventually run out. Once

they‟ve run out, they obviously need to be replaced. By using brushes it also limits the

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number of poles being emitted by the armature. In addition by placing the electromagnet

on the outside instead of the inside makes its cooling process easier.

Additionally as if that‟s not enough the BLDC provides higher efficiency, and increased

reliability. It reduces noise and eliminates the ionizing sparks created by brush contact.

The electromagnets will receive cooling by conduction, which will allow the internal

motor to be enclosed and provide protection from foreign substances. The BLDC also has

a longer lifetime than the brushed motor, which will support a long lifetime for

SmartCopter. The brushless motor also consumes less energy, and with a reduced EM

interference it helps reduce radio interference.

The disadvantage of using the BLDC however, is the cost. Although the motor is more

efficient than its former model, it is still not greatly used in the commercial sector. It also

requires a very complex electronic speed controller, which is used to basically vary the

drive motor‟s speed and direction. Combine these two important criteria together and

they both more than likely contribute to the high cost of the BLDC.

Cost aside, the brushless motor is our best choice. Not only is it included with the

helicopter purchase but given the data presented and additional research SmartCopter

should maintain superb motor efficiency with this model of the brushless motor.

The figure below is a Brushless Motor property of Howstuffworks.com

Brushless Motor from Howstuffworks.com

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4.2.1.2 Flight Surface Control

4.2.1.2.1 Servos

A servo is an automatic device that generally uses error sensing feedback to provide

correction to the mechanism performance. Servos are generally used in an automatic

system where the error-correction or feedback signals assist controlling the mechanical

position or other parameters. A servo mechanism is unique in that it controls a specific

parameter by the command of the time- based derivative of that parameter. Most servos

are commonly electrical. There are other types of servo use as well, pneumatics, magnetic

principles, and hydraulics. Within helicopters, servos are electrical devices that help

control flight.

There are two types of servos, standard and digital. SmartCopter will be using a digital

servo because it operates more efficiently by eliminating the “deadband” which is found

in the standard servo. By removing the “deadband” the rate at which the servo receives

pulses increases dramatically from approximately 50 to 300 pulses. On standard servos

the rate is around a maximum of 50 pulses per second.

The standard servo is less efficient for SmartCopter, because of the exceptionally fast

rate within the standard RC servo that allows minutely small movements from the control

stick to have no affect at all. This has been known as a “deadband” on the control stick,

where no servo movement takes place. This causes no problems for most other RC

designs; however for 3D aircraft any small delays can cause a collision. Which is why the

digital servo is a much better choice for SmartCopter, the resolution increase provides the

helicopter with more precise servo operation.

RC servos are small electro-mechanical devices that are built out of a few gears, an

electric motor and a head in which a wheel or arm can also be attached. This device

responds to a control signal by converting the angular momentum of the servo arm to the

linear movement of the control surface. Servos are designed to maintain or hold position.

Because the aircraft is in constantly interacting with external forces, servos are needed as

grounds for holding the current position; otherwise SmartCopter would be able to remain

in one location for a period of time. Without the servos the external forces would set

control surfaces to undesired and unwanted positions. The command is fulfilled when the

user communicates what angular position to move to, the servo then rotates and holds the

desired position until it receives a new command.

Three wires control the RC helicopter servo: one sends the signal, which controls the

servo, two that provide the DC electricity which is needed by the motor. The three wires

are a ground wire, a signal wire, and a power wire. Servos are normally connected into a

three pin-connector, radio receiver. The servo works by receiving a series of pulses sent

over a control wire that control the angle of the actuator arm. The pulses must be

consistent to gain accurate information on the angle. The signal wire carries a Pulse

Width Modulation (PWM) signal, which consists of a varied 1-2ms pulse repeated at fifty

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or more times per second. The servo will move to -45 degrees by a 1ms providing it has a

90 degree range of motion. A 2ms pulse will shift the servo to +45 degrees. A servo pulse

of 1.5ms will shift the servo to its “neutral” position or center, 90 degrees.

The electric motor inside the servo is mechanically linked to a potentiometer. Once the

servo receives the PWM signals, they have been translated or converted into positional

commands by the internal electronics of the servo. When the servo receives the command

to rotate, the system powers the motor until the resultant commanded position is reached

by the potentiometer.

There are several specifications that the servo is comprised of: torque, speed,

dimensions, weight, bearings, gears, and the motor. The torque measures the “strength”

of the servo, or the amount of “push” it holds. The torque‟s rating states the amount of

force the servo can exert. Naturally the higher the number, the more force the servo

exerts or the stronger it is. The bigger the aircraft the higher the torque servo, in general

the servo size increases with rated torque.

The speed of a servo is determined by the number of seconds that are taken to move a

specific amount of rotation, generally 60 degrees. The speed measures how quickly the

servo is able to move from one position to another. High speed servos in general are more

expensive than standard ones but are more efficient for 3D helicopters and other aircraft.

The dimensions of a servo are increased with the amount of torque that is provided.

Although SmartCopter is a 3D helicopter it must still maintain a certain weight

restriction. The servo should be strong enough to handle the demands successfully and

light enough to not add too much additional weight to the design structure.

The support of the main shaft can be handled by bushings or bearings. Standard servos

are generally supported by bushings, and larger more heavy duty servos are supported by

bearings. The bearings cost more than the brushes but are more durable. The gears of

most servos are either metal or nylon. Metal gears weigh more and wear over time but

they do not “strip” or shred, which is the cause of many RC helicopter crashes. Many

higher end servos use metal gears. In additional to metal and nylon there is karbonite and

titanium as well. The karbonite is approximately 4 times stronger than the Nylon material

and it offers better wear resistance in comparison to the metal material. The titanium gear

is considered to be the best on the market. It offers no wear and tear at all. Of course with

the increase in performance there is always the increase in cost. For SmartCopter and

other hobby based RC aircraft, the nylon or metal material should work well. Figure 1

and 2 are photos of RC servos provided by Wikipedia.

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Figure 1 Figure 2

Figure 1: RC Servomechanism Unassembled

Figure 2: RC Servomechanism. 1. Electric motor 2. Position feedback potentiometer 3.

Reduction gear 4. Actuator arm

4.2.1.2.2 Accelerometers

Conceptually accelerometers are devices that measure the acceleration, or the force

being experienced due to gravity‟s freefall. More advanced models also detect direction

and magnitude of the acceleration as a vector quantity, which can be used to sense shock,

vibration, and orientation. Accelerometers can be used to determine the angle at which

the device is tilted with respect to the earth, by calculating the amount of static

acceleration it experiences due to gravity.

Accelerometers also known as electromechanical devices have many uses. For

SmartCopter its purpose is to help it understand its surroundings. It helps determine its

orientation, whether it‟s driving uphill, or downhill, or flying horizontally. Other uses

include health monitoring systems. Accelerometers are used to rotate equipment for

machinery health such as fans, compressors, pumps, rollers, and cooling towers. They

help cut costs by reducing downtime, and by detecting conditions such as rotor

imbalance, gear failure, shaft misalignment, or bearing fault. Accelerometers help

improve safety in plants around the world. Without these detection devices the plants and

other technologies can result in costly repairs.

There are several categories of accelerometers. The three different technologies consist

of piezo-electric accelerometers, piezo-resistive accelerometers, and strain gage based

accelerometers. There are also different designs of accelerometers. There is the shear type

design, the flexural design, the single ended compression design, the isolated

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compression, and the inverted compression. Accelerometer types include the premium

grade, the high vibration, the triaxial, and the industrial grade.

The premium grade accelerometers use a low noise circuitry to produce a top quality,

low noise accelerometer. They are made from top-rate crystals, and their stainless steel

case is securely sealed against the environment, to protect it from harsh industrial

environments and exposure to weather related causes. The design of the high vibration

accelerometers is a bit different in that it is used to supervise high vibration levels. They

can supervise vibration levels up to 500 g‟s. The high vibration accelerometer is designed

for use on shaker tables, heavy industrial machine tools, and vibration labs due to its stud

mount design. The tri-axial accelerometers measure the vibration in the three axis, X,Y,

and Z. They consist of three crystals uniquely positioned so that each axis experiences a

crystal‟s reaction. The output consists of three signals, in which each one represents the

vibration from a different axis. The fourth type is the industrial grade. These

accelerometers are most common from machine tools to paint shakers. They come in

different models and are also sealed against the weather and industrial environments.

An IEPE accelerometer is a class of accelerometers that have built in electronics. It

stands for Integrated Electronics Piezo Electric. This class of accelerometers particularly

has low impedance output electronics and they work with two wires to provide a constant

current supply. Compared to the three wire accelerometers the two wire ones are easier to

install, cheaper to purchase, they can travel over long cable lengths, and contain a wide

frequency response.

Additionally there exist two types of piezoelectric accelerometers. The first is the low

impedance output accelerometer and the second is the high impedance charge output. The

low impedance accelerometer has a small built-in FET transistor and micro-circuit that

convert the charge from the charge accelerometer at its front end, into a very low

impedance voltage which is used with standard instrumentation. The high impedance

accelerometer uses the piezoelectric crystals to produce an electrical charge that is sent

directly to the measuring instruments. For this design the output charge demands special

instruments and accommodations which are often located in research facilities. The high

impedance accelerometer is often used where low impedance designs are unsuccessful.

Accelerometers are often used to measure the vibration and motion of structures that are

exposed to dynamic loads. Dynamic loads originate from a variety of sources including

earthquakes, wind loads and wind gusts, and human activities which consist of walking,

running, dancing, and skipping. They have also been used in sports watches that help

determine the distance and speed for the runner wearing the unit. Accelerometers are also

used as motion sensors for navigation systems. SmartCopter will need the accelerometer

to calculate continuously the position, velocity, and orientation of it without external

forces being needed. This is part of the Inertial Navigation System (INS) also known as

the inertial guidance system.

Within SmartCopter the accelerometers work alongside the gyroscopes to calculate the

necessary tilt. Within automobiles accelerometers are used as detection devices in order

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to deploy the airbags. In order to determine when a collision has occurred and the degree

of severity of the collision, the accelerometers are used to detect the swift negative

acceleration of the automobile. They can also be found on many personal electronic

devices such as Apple iPhone, the Blackberry Storm, and the Sony Ericsson W910i

amongst others.

The latest gaming system the Wii also contains accelerometers in its remote system. The

remotes contain three-axis accelerometers to sense movement, which is a complement of

its pointer functionality. I have played the Wii, and playing with remotes that have

excellent pointer functionality makes for an enjoyable experience. It would be a stressful

game if the remotes didn‟t point where the user aimed. The accelerometer design makes

the game more realistic.

Accelerometers are also built into laptops in case of mishaps. This has recently begun

with IBM and Apple. If the laptop accidentally drops, the accelerometer detects the

unanticipated freefall simultaneously, and switches the hard drive off so the heads are left

intact and not shattered.

The important specifications for an accelerometer consist of: bandwidth, sensitivity,

analog vs. digital, grounding, and buffering. The bandwidth represents the number of

times per second a reliable acceleration reading is taken. SmartCopter will probably use a

very high bandwidth because it will be a fast moving aircraft. In general the more

sensitivity there is the better. Sensitivity is the known output voltage produced by a

specific force, which is measured in g‟s.

High output accelerometers are used to measure any low level vibrations, while low

output accelerometers are used to measure any high vibration levels. Temperature

sensitivity is the output voltage for each measured degree.

SmartCopter will probably use digital accelerometers which use PWM for their output.

Analog accelerometers output an acceleration that is proportional to continuous voltage.

For the digital accelerometers there will exist a square wave of a specific frequency, and

the amount of acceleration will be proportional to the measure of time the voltage is high.

Figure 1 is an accelerometer designed by the Archimedes Automated Assembly Planning

Project at Sandia National Laboratory. Provided by Wikipedia

Figure 2 is Triple Axis Accelerometer Breakout- ADXL 335. Provided by Sparkfun.com

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Figure 1: Property of Wikipedia Figure 2: Property of SparkFun.com

4.2.1.2.3 Gyros

The gyros are essentially important to SmartCopter because their job is to ensure that the

direction of the nose is pointed in the desired direction. The reactive torque of RC

helicopters is constantly changing. Any decrease or increase in the pitch or engine speed

of the main rotor blades results in a change in torque. These changes are often caused by

wind gusts and are constantly responsible for trying to spin the helicopter.

When RC helicopters rotate on their yaw axis the direction in which the nose points

changes. The yaw gyro in effect helps control unwanted movement. When any undesired

rotation is detected the yaw gyro automatically corrects it. Without the yaw gyro, even if

SmartCopter is flying as straight as it possibly can, it will still experience drifting and

rotating from left to right. Formally the only type of gyro available was a mechanical

device; however they used up an enormous amount of battery power and were quite

heavy. Today most helicopter designs use piezo gyros.

Unlike the mechanical gyro, the piezo gyro does not function by utilizing moving parts.

Instead a piezo-like element is placed on either side of a triangular crystal. This piezo

element is found in many watches as the beep sound for the alarm function. Because the

piezo element not only makes sounds but senses it, it is often found in microphones and

speakers. As part of the piezo, two of the elements of the crystal are used to sense

vibration; the other is used to make vibration(s).

Within the helicopter design, when it is rotating, one sensor will maintain a stronger

signal than the other. When the helicopter is not rotating the two piezo elements make

contact with the vibration traveling through the crystal. This design is efficient and

consumes less power because there are no moving parts, or spinning motors. Today we

have the piezo gyro, in which there are two types of helicopter gyros available, the

heading hold (HH) and the yaw rate (YR).

The heading gyro uses computer software to detect the unwanted motion, correct it, and

then return the nose to its original position. This gyro continues to send commands to the

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tail rotor even after the motion stops. The heading gyro uses specialized software to

calculate the number of degrees the yaw or heading changes on the helicopter. The tail

rotor then receives this calculation as a direct command that it has been converted into.

The calculation in the form of a command appropriately corrects the amount of deviation

the heading of the helicopter was experiencing, it also dampens the movement.

With the heading hold gyro the helicopter is essentially locked, and its nose is unable to

change course no matter the outside movement. The helicopter will not change direction

until the rotor receives a new command to do so. By using the heading gyro, the tail rotor

servo is completely controlled by the HH gyro and its software.

The rate gyro functions a bit differently from the heading hold gyro. It works to dampen

the effects of any unwanted movement towards the yaw axis, not offer continual

correction. Once the unwanted movement has been detected, the rate gyro corrects it, and

then it stops correcting. For example SmartCopter is hovering and a gust of wind hits it

from the side. The rate gyro will stay the helicopter from thrusting its nose into the wind.

Eventually however the nose will drift into the wind. So the yaw rate gyro will not

prevent SmartCopter from turning but it will dampen the turning to a reasonable control

level.

There are two disadvantages to using the rate gyro. One is that unlike the heading hold

gyro the rate gyro does not return the helicopter to its original position. The second

disadvantage is that the corrective action is always late, because the motion is corrected

after it‟s been detected. The advantage of course is that unlike the heading hold gyro the

rate gyro does not completely take over the tail rotor servo.

Some of the disadvantages of using the heading hold gyro are that there are a lot of

demands placed upon the helicopter system as a whole. It requires a fast tail rotor servo,

and a much powerful battery to supply the servo. This route not only strains the servo, but

also consumes more power.

These requirements will need to be supported by a higher capacity battery because the

servos and gyros will need to be accounted for as well. Working with the heading hold

gyro will be a challenge because SmartCopter needs to be as light as possible. However

with the heading hold gyro a larger battery may be necessary to compensate for the

increase in power supply.

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These pictures are property of Sparkfun.com. They are photos of the gyro breakout board

that will be used with SmartCopter.

Gyro Breakout Board - IDG500 Dual 500 degree/sec - Property of SparkFun.com

4.2.1.2.4 Ultrasonic Range Finder

The ultrasonic range finder is a device used to measure distances between moving and/or

stationary objects. They operate without making contact with the measured surface. They

are useful in security systems and as possible infrared replacements. The ultrasonic range

finder contains a ping sensor. This ping sensor is responsible for measuring the distance

using sonar. By transmitting an ultrasonic pulse from the unit, the distance is determined

by measuring the time taken for the echo to return to the sensor. The ultrasonic pulse is

beyond human hearing capability.

The output that comes from the ping sensor is known as a variable-width pulse that

corresponds to the target‟s distance. How the device works is by using a pin to trigger the

ping sensor and then it listens for the echo‟s responding pulse. The distance to the target

can be effortlessly calculated by measuring this echo pulse.

The ultrasonic range finder will be useful to SmartCopter because the aircraft will need to

know its distance from the ground and any moving or non moving object at all times.

Without this device SmartCopter may not be able to function as a completely

autonomous aircraft without the user monitoring i‟s flight sequence to determine what

obstacles are in its path. By using the ultrasonic range finder SmartCopter is completely

dependent upon its own built-in components. The figure below is the sensor that will be

used with SmartCopter.

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Ultrasonic Range Finder – Maxbotix LV-EZ2 – Property of Sparkfun.com

4.2.1.3 Noise Filtering

Noise control is any passive or active means of minimizing sound emissions. Before

work is begun to reduce the noise, the source must first be located. Once the source of the

undesired sound has been located then the focus is to reduce the noise using engineering

applications. Noise reduction is the process of removing unnecessary noise from a signal.

There are different types of filtering devices.

In electronic devices a hissing noise is the undesired noise. The hissing is caused by

random electrons that have strayed from their path, due to heat influence. The voltage of

the output signal is influenced by these drifting electrons, and thus these electrons are

responsible for creating detectable noise.

Within SmartCopter noise will exist between the interfaces. We will need to use filters

such as the low-pass, high-pass, and band pass filters to recover the purest, original

signal. If not there will be a lot of mixed signals which will interfere with the

corresponding data. SCMs, signal conditioning modules, are used to measure process

control variables such as pressure, position, level, speed, temperature, and strain.

These control variables are constantly subjected to exterior induced noise signals. In

industrial measurement it‟s inevitable to avoid these noise sources which are formed of

electro-magnetically induced voltages or currents. The majority of noise voltages are

directly induced as the result of altering magnetic fields such as weather caused electrical

storms, and electric motor variable speeds.

Special shielded wires, appropriate grounding techniques, exist to help reduce induced

noise levels. In many cases however these techniques do not effectively reduce these

undesired noise signals. Noise signals embedded with signal detection modules are quite

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effectively used to minimize noise signals. There are three common filters that can be

used as the foundation for noise reduction: the low-pass filter, the high-pass filter, and the

band-pass filter.

The low-pass filter that accepts low-frequency signals and attenuates the higher

frequency signals above the cutoff frequency. The concept behind the low-pass filter

evident in different forms, some of which include digital algorithms for smoothing data

sets, blurring imagery, and electronic circuits.

With acoustic structure, the low-pass filter functions as a filter for transmitting sound and

is presented in the form of a physical barrier that tends to reflect higher frequencies.

Within the electronic structure, the low-pass filter is used to drive subwoofer (special

loud speaker) and other types of loud speakers, to block the high pitches that can‟t be

officially be broadcasted. Low-pass filters are also used in radio transmitter to block

harmonic emissions which can cause interference with other communications.

SmartCopter will certainly need a well balanced noise filtering system, to avoid any

major interference issues. The noise factors will almost always be present but if they can

be minimized to a low, SmartCopter can function at its best. Ideally the desire is to

eliminate all noise interference. The figure below represents the graph of an ideal low-

pass filter property of Wikipedia.

Ideal Low-pass Filter

For discrete-time realization, according to Kirchoff‟s Laws and the definition of

capacitance, the equations for a low-pass filter:

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where Qc(t) is the charge stored in the capacitor at time t. Substituting Equation (Q) into

Equation (I) gives , which can be substituted into Equation (V) so

that:

The high-pass filter is the opposite of the low-pass filter. It passes high frequencies well

and attenuates the lower frequencies below the cutoff frequency. They are also used in

audio applications. The simple first-order electronic high-pass filter is implemented by

placing an input voltage across the series combination of a resistor and a capacitor using

the voltage across the resistor as an output. For a passive high-pass filter the cutoff

frequency is equivalent to:

Where fc is in Hertz, τ is in seconds, R is in Ohms, and C is in Farads.

The figures above are property of Wikipedia.com

For an electronic implementation of a first-order high-pass filter an operational amplifier

is used in the figure below. The corner frequency is:

Active High-pass Filter

Discrete-time high-pass filters can also be designed. Discrete-time systems are described

in terms of difference equations. It refers to non-continuous time. According to

Kirchoff‟s Laws and the definition of capacitance the equations are:

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Where Qc(t) is the charge stored in the capacitor at time t. Substituting Equation (Q) into

Equation (I) and then Equation (I) into Equation (V) gives:

The band-pass filter uses both the low-pass and high-pass filters to pass frequencies

within a specific range and rejects the frequencies outside that range. An ideal band-pass

filter would consist of a flat pass-band and would attenuate completely all frequencies

outside the pass-band. No band-pass filter is ideal in practice.

The filter is unable to attenuate all outside frequencies. There is a region known as the

filter roll-off region located outside the pass-band area where frequencies are attenuated,

but not rejected. Band-pass filters have other uses outside of engineering applications

such as in atmospheric sciences. The figure below is property of Wikipedia.

Band-pass Filter

The physical applications of these filters have yet to be tested within SmartCopter, but

the aircraft will encounter some noise feedback, and these filters provide an introductory

solution to attenuating that unwanted noise.

4.2.1.4 Global Positioning System (GPS)

Before May 1 2000 civilian GPS‟ accuracy was purposely worsened by errors introduced

by a feature called Selective Availability in an effort, by the military, to prevent guided

weapons being created by the enemy. These errors could cause readings to be as far off as

100 meters and were on the average 10-20 meters off. However on that date president

Bill Clinton, with the support of other agencies, removed Selective Availability.[1]

Turning off the error for civilian GPS and in turn creating the ability for more accurate

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readings. Readings are now possible down to within 5 meters in accuracy for even

common civilian GPS devices, which is well within our requirements.

The GPS we will be using for our project is the EM-406A GPS shown in Figure 4.x

module from USGloabalSat. The EM-406A is based off the SiRF Star III chipset and has

an accuracy of 5 meters and time accuracy of 1microsecond. It is powered by 5 volts DC

at 44mA. The initialization time is dependent on whether or not initial location is given,

called a hot or cold start. The time for cold start initialization is 42 seconds on average

and the time for hot start initialization is 1 second on average. Reacquisition time is on

average 0.1 seconds. The output format for the GPS is a formatted string broadcast via

TTL over RS232. The output string format varies depending on the mode the GPS is in,

which can be identified by the protocol header at the beginning of the string. The GPS

unit updates its position every 1 second.

20 Channel EM-406A SiRF III Receiver with Antenna – Property of Sparkfun.com

Page | 35

[15]

Figure 4.2.2

Position of the GPS device is crucial to its function as it requires line of site in order to

get a good signal. However this poses some design problems on a platform such as our

helicopter. It needs to be mounted on the top of the helicopter to get good signal but at 16

grams this poses problems with shifting our center of gravity too high and hurting the

stability of our helicopter. To try to minimize this effect the receiver will be placed on top

of the fuselage just aft of the main rotor, as far forward as it can be. From there it‟s as

easy as connecting the TX and RX lines to the microprocessor and reading in the value in

software when it‟s needed. It will then be up to the microprocessor to parse the string and

come up with its numerical position.

4.2.1.5 Micro-Controller

To bring all of our hardware together we have our micro-controller. To be specific the

PIC18F4610,the 40 pin PDIP package shown in Figure 4.1.3.4.1, is the chip we will be

using for our project. With an internal clock of 48MHz it comes with a performance of

12MIPS providing plenty of processing power for our stability needs. On board the chip

has 64k of program memory and 2k of data memory, along with a 256 byte EEPROM.

Efficiency is improved with a limited instruction set of only 75 instructions with 8 more

extended instructions. Also provided are 13 analog to digital channels providing 10-bit

precision, which will be used to read our accelerometer and gyroscope data. The chip also

supports full USB 2.0 with a maximum transfer speed of 480Mb/s.

Page | 36

[10]

Figure 4.1.3.4.1

Our chip also features various power modes and clock scaling abilities. While for a

majority of our project our CPU will be in the RUN mode it's important to at least

acknowledge the other modes. For example the CPU is capable of an IDLE mode where

periferals all remain on while the CPU is off and a SLEEP mode where the peripherals

and CPU are off. The sleep mode is the standard legacy sleep mode offer in all PIC

devices and is enabled by clearing the IDLEN bit and executing the SLEEP instruction.

This will bring the currently selected clock to a stop until an interrupt is detected.

Alternatively the IDLE mode can be selected by setting the IDLEN bit to '1' and again

executing the SLEEP instruction. However this time the peripherals will remain clocked

while the CPU isn't and will remain in IDLE mode until an interrupt occurs. However for

our project we need the CPU to remain in the running, for that reason these modes may or

may not be implemented.

Another important feature of our CPU is it's clock selection and scaling abilities. Our

chip features support for two external clocks up to 48MHz along with eight different

internal clock modes ranging from 8Mhz to 31kHz. This gives us a total of 12 different

clock modes. The first four, HS, HSPLL, XT and XTPLL, modes are for when a crystal

resonator is connected to the pins OSC1 and OSC2. An internal postscaler allows the user

to scale this frequency by 1/2, 1/3, or 1/4 of the original frequency. There is also a PLL

module for frequency multiplication that will be discussed a little later. For our project

we will likely have a 20MHz resonator crystal connected externally to pins OSC1 and

Page | 37

OSC2 shown in the diagram in Figure 4.1.3.4.3. C1 and C2 will be set at 15pF based off

specifications in the PIC18F4610 data sheet.

[10]

Figure 4.1.3.4.3

The next four modes are for support of external clock sources and are, EC, ECIO,

ECPLL, ECPIO. The IO modes provide input and output on the RA6 pin. The PLL

modes are used as a frequency multiplier and is designed to produce a 96MHz clock from

a 4MHz source. The block diagram showing the PLL frequency multiplier is shown in

Figure x.x. This rounds our external clock sources.

[10]

Figure 4.1.3.4.4

Page | 38

The final four modes, INTHS, INTXT, INTCKO, and INTIO, we have are the internal

clocking modes which can be used to drive two separate clocks. These modes all use the

internal clock for the micro-controller and depending on which of the four modes a

seperate clock is used as the clock for the USB. In the INTHS mode the USB clock is

provided by the oscillator in HS mode. Likewise in the INTXT mode the USB clock is

provided by the oscillator in XT mode. The other two are for when a external clock is

supplied the difference between the two being that INTCKO sets the OSC2 pin as Fosc/4

while INTIO sets the OSC2 pin as regular digital IO pin. More than likely the preferred

mode we'll be using will be the INTHS mode such that we can use the 20MHz external

resonator shown earlier to drive our USB module and our internal clock for our micro-

controller.

One of the most import features of our micro-controller for our project is the 10-bit

analog to digital converter module. The chip we selected has support for up to 13

channels of A/D conversion. The module has five important registers, the A/D Result

High Register (ADRESH), A/D Result Low Register (ADRESL), A/D Control Register 0

(ADCON0), A/D Control Register 1 (ADCON1), and the A/D Control Register 2

(ADCON2). A table showing the register layouts and what the values correspond to is

shown below in Figure x.x.

ADCON0

--- --- CHS3 CHS2 CHS1 CHS0 GO/ DONE ADON

Bit 7 Bit 0

CHS3:CHS0: Analog Channel Select bits

GO/ DONE : A/D Conversion Status bit

0 = A/D idle

1 = A/D in progress

ADON: A/D Enable bit

ADCON1

--- --- VCFG0 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0

Bit 7 Bit 0

VCFG0 (bit 5): Voltage Reference Configuration bit Low

0 = VSS

1 = VREF- (AN2)

VCFG0 (bit 4): Voltage Reference Configuration bit Low

0 = VDD

1 = VREF+ (AN3)

PCFG3:PCFG0: A/D Port Configuration Control Bits

Sets number of analog channels to use.

Page | 39

1111 = No digital Channels

1110 = 1 Analog Channel

…

0010 = 12 Analog Channels

ADCON2

--- --- ACQT2 ACQT1 ACQT0 ADCS2 ADCS1 ADCS0

Bit 7 Bit 0

ACQT2:ACQT0: A/D Acquisition time select

111 = 20 TAD 011 = 6 TAD

110 = 16 TAD 010 = 4 TAD

101 = 12 TAD 001 = 2 TAD

100 = 8 TAD 000 = 0 TAD

ADCS2:ACQT0: A/D Conversion clock select bits

111 = FRC 011 = FRC

110 = FOSC/64 010 = FOSC/32

101 = FOSC/16 001 = FOSC/8

100 = FOSC/4 000 = FOSC/2

The basic idea behind using the A/D module is first initialize the converter, setting the

registers ADCON2:ADCON0, and then turning on the converter with the ADON bit.

Next step would be to configure the A/D interrupt so it goes to our ISR when the

conversion is done. Then if you the capacitor CHOLD isn‟t charged you have to wait a

given acquisition time which is typically in the 2.5 microsecond range. Once these

requirements are met you can begin conversion by setting the GO/ DONE bit and then

wait for the interrupt. Once the interrupt hits read the values in the ADRESULT registers

and reset the interrupt.

The GPS module will be controlled via a simple RS232 interface using a formatted

string.

One of the major advantages of the chip we selected is that it comes ready out of the box

to be used with USB. It does this with an onboard Serial Interface Engine or SIE

complete with its own 1k of RAM dedicated to USB. While the micro-controller does

have access to all sections of the RAM, sections being used by the SIE should not be

accessed. The block diagram showing each of the USB peripheral‟s components is shown

below in Figure 4.1.3.4.9.

Like the various other modules talked about earlier in this section the USB has multiple

control registers that are used to initialize the device. Along with the control registers is a

status register much like the one provided on the analog to digital convert. The

transceiver for the USB peripheral is built-in and support regular USB and USB 2.0 full-

speed transfers. The module has support for use with an off-chip transceiver however for

our project we will likely just make use of the internal transceiver.

Page | 40

[10]

Figure 4.1.3.4.9

Now that the various chip peripherals are defined we can address the issue of the memory

layout on our micro-controller. The diagram below in Figure 4.1.3.4.10 shows the general

layout of the micro-controller‟s memory. Program instructions are stored on the on-chip

flash memory. Memory is addressed in bytes and instructions are stored as two bytes or

four bytes depending on the type of instruction. The instruction set is comprised as 70

instructions with 15 more extended instructions. The device is programmed over an ICSP

connection which is shown in Figure 4.1.3.4.11. The other memory used is 256 bytes of

EEPROM non-volatile storage for holding any data such as constants that may be needed.

Page | 41

[10]

Figure 4.1.3.4.10

The schematic showing the planned connections on our printed circuit board are shown

below in Figure 4.1.3.4.11. There is also a button and an LED not shown, the LED is on

pin PORTA 0 and the button is on PORTE 2. The schematic also shows how the analog

modules and SD card will be hooked up to the micro-controller. The PIC in the schematic

is still labeled as being a PIC18F4550 but it should be noted that it is in actually a

PIC18F4610.

Page | 42

Figure 4.1.3.4.11

4.2.2 Software

The software for our project will be split into two sections. The first section we'll focus

on is the embedded software that will be going for a flight with our helicopter, later on

we'll discuss base station software used to analyze data once the flight has concluded.

The embedded software will be laid out in a hierarchy shown below in figure x.x. At the

bottom of the hierarchy are the sensor modules for each individual interface. The first of

which is the analog digital convert module which allows for analog signals to be read

from the accelerometers, gyros, and digital range finder. The values will be read

sequentially and then stored into an array of sensor data that can then be accessed by

higher functions in the hierarchy. It is also worth noting that the analog digital convert

module does not store any information other than the last read value from each sensor. It

is up to the general sensor module to keep track of past values to find rate of change,

which we will go into more in depth later.

Page | 43

The next sensor module to discuss is the GPS module. This module is similar in that no

calculations are done here, only the last value read from the GPS is stored so it that can

be retrieved by the modules higher on the hierarchy. However this module differs in the

way that the data is read. Instead of using the analog digital convert, the data is read

through a serial interface that retrieves a formatted string from the GPS unit. This string

is then parsed such that the positioning data is extracted and then saved so that it may be

retrieved later. The only data saved from the parsed string will be the latitudinal position

and the longitudinal position.

It will be the job of the general sensor module to keep track of previous values and track

the change of these variables over time. For example with the data obtained by GPS, by

tracking the previous location compared to the current location we can deduce an

estimation of the speed of our craft. The other example of the general sensor module's

responsibility is tracking the past measurements from the gyro and accelerometer. By

integrating these values over time, for example from the accelerometer we can track a

rough estimation of the motion, which we can then use to check the values from our GPS

sensor module. Integrating again with respect to time yields a rough estimation of the

position of the craft. The extent of this will be just limited to simple error checking,

further integration and analysis will be designed in the base station software. It is also the

job of the general sensor module to relay the sensor information to the higher levels of

the hierarchy. Unlike other modules the GPS has no initialization required due to the fact

that once the GPS unit has power it immediately starts outputting its position. The GPS

string parsing will be done depending on what type of output the device is set for.

Initially however no string parsing will be done and the direct data from the GPS is sent

Page | 44

to the SD Card. For example purposes I‟ll go over the most important output formatting

which is the GGA format. All strings output by the GPS start with a header indicating the

protocol of the message and each data field is separated by commas. For GGG the header

line will be „$GPGGA‟. A sample input string and table showing the stored values are

shown below in Figure 4.1.4.3.

[11]

Figure 4.1.4.3

Finally the last lower level module to design is the module in charge of writing to the SD

card. This is done through an SPI interface using existing library AN1045 available on

the Microchip website. Using a FAT32 file-system every time the SmartCopter is

initialized a new file is created on the SD card with the current date and start time as the

filename. It will then write all data received to the file writer module and put it in that file

until the end of the flight. It will store the current time of the flight in a time stamp at the

beginning of every data recording. This will be then followed by the location in latitude

and longitude followed by the altitude. Following this will be the accelerometer and gyro

data, initially just raw data from the sensors will be stored however later on adjustments

could be made such that some processing of the data could be done before it is stored and

included as with the raw data.

Controlling everything is the top level module controller. It‟s job is to initialize each

component and synchronize each event. At the start of every flight it will initialize the

sensor module and the file writer module, creating a new file every time a flight is

Page | 45

initialized. It will then be the controller‟s responsibility to have the sensor module update

each sensor and then pass that information to the file writer to all it to update the file.

Once the flight is complete the controller will then close the file writer and stop updating

the sensors. It will then wait until another flight is requested where it will return to the

beginning and start the process over.

The next piece of software in our project will be the software running on the base station

that‟s task is to read back the data stored in the flight and represent it a meaningful

graphical way. To accomplish this we will store the data streamed wirelessly to a hard

drive via a TV Tuner card and recording software. This video will then be synced up with

the data that was stored on the SD card. To accomplish this we will use the Java Media

Frame work to embed the video into a Java GUI along with various measurements of

data. A rough example of this GUI is shown in the figure below

GUI Sample

The code for the base station will also be laid out in a hierarchy with a main controller at

the top making sure everything is initialized and synced up. On the next level there will

be a video controller responsible for getting the correct image onto the GUI based on

what time in the flight currently marked. Also on this level is data manager that handles

the data being read off the SD card. The data manager is passed a time from the controller

and using that time will return a series of measurements from each device from the file on

the SD card. Finally at the very bottom of the hierarchy is the video encoder which

handles the raw video data such that it can be displayed onto the GUI and there is also a

raw file manager that handles reading from the SD card and passing that information onto

Page | 46

the data manager. An overview of the hierarchy for the base station software is shown in

the figure below.

Hierarchy overview for the Base Station Software

Page | 47

Chapter 5: Testing Procedures

5.1 Helicopter Flight

Since maintaining stable flight is going to be a major aspect for project SmartCopter,

many tests will need to be done to ensure the project will occur without fail. Due to the

potential financial burden that a failed mission would incur, learning the flight

characteristics and flight controls of the helicopter is an absolute necessity. In order to

ensure the structural integrity of the helicopter, certain test procedures need to be

implemented. To start off with, team SmartCopter needs to become familiar with manual

flight controls of the helicopter. To accomplish this, the whole team will learn how to

manually fly the helicopter via a computer flight simulator. The flight simulator allows

the user to virtually fly and control the helicopter without physically flying it. This is a

must for any person who has never operated a radio controlled helicopter. Fortunately

the helicopter the team will be purchasing includes a flight simulator for that particular

model helicopter. The flight simulator will aid the team in learning the extremely

complicated controls for a helicopter. The simulator will teach the team how to utilize

the different components of flight, such as pitch, roll, and yaw, to maintain stable flight.

Figure 5.1.1 displays the typical flight controls:

[17]

Figure 5.1.1

Typical helicopter flight controls

Page | 48

The flight simulator that will be utilized for learning the necessary flight controls is the

ClearView RC Flight Simulator®. The program comes preloaded with a variety of exact

model rc helicopters to choose from. However the simulator also allows for specific

model radio controlled helicopters to be loaded into the program for more accurate and

realistic results. Another reason the ClearView RC Flight Simulator® was chosen was

due to its various landscape and weather choices. The ability to control the helicopter in

varying weather and climate conditions will contribute to better piloting skills of the

team. Since the team will not be able to predict what the weather conditions will be like

on the presentation day, they will need to feel confident they can successfully pilot the

helicopter in less than ideal conditions. This particular simulator also supports multiple

controller options. These include keyboard input, PlayStation 3® controls, and the rc

transmitter via usb input. Since helicopter flight is complicated and difficult to master,

the team will begin by learning on the PlayStation 3®

controller. This is due in part to the

familiarity of the team to the PlayStation 3® controller, and the complexity of the layout

of the transmitter controls. This will allow the team to learn the aspects of helicopter

flight first, without having to simultaneously learn the controls of the transmitter. The

team will then transition to the use of the actual transmitter purchased with the rc

helicopter model Esky Belt-CP 450.

After the team has successfully completed the necessary flight simulator controls, they

will learn to fly the helicopter manually. Manual controls are accomplished via the

included 6 channel transmitter (72 MHz, Mode 2) and receiver. The beginning stages of

this particular phase of testing will occur in the back yard of a single home property

located off of University Blvd referred to as testing location 2. A map and directions to

testing location 2 are outlined in Figure 5.12.2. This testing phase does not require a very

large area for testing, as the helicopter will be secured to a homemade testing stand. The

homemade test

stand will be

constructed

utilizing the

following

components:

36”L x 36”W x

2”D plywood

base, 36”L x 2”W

x 4”D lumbar, (4)

1/8” u-bolts and

nuts. The test

stand will function

as a mode of

securing the

helicopter to an

immobile

platform, while at

the same time still

allowing for

Page | 49

freedom of flight. The test stand will be constructed as depicted in Figure 5.1.2. Detailed

plans needed for fabrication of the stand are depicted in section 5.11.

The necessary holes will be drilled into the plywood stand base allowing for the insertion

of the u-bolts. Documentation relating to the construction of the test stand is outlined in

Figure 5.11.1. The helicopter will then be secured to the base by placing the landing

skids between the previously drilled holes. The u-bolts will then be fastened to the base

via the corresponding 1/8” nuts. The maximum distance of the eye of any u-bolt and the

top of the base shall not exceed 2”. This basically will limit the altitude the helicopter

will be able to achieve, while still allowing proper testing during the take-off and landing

procedures. Measurements need to be recorded during take-off and landing to test how

the shock of the impact affects the recorded data. The configuration of the test stand, as

depicted in Figure 5.1.2 with the u-bolts not completely securing the unit to the stand,

will be the only occurrence of this setup. However this will not be the last use of the

actual base of the stand. An additional setup will be utilized in later testing.

After the team feels confident that they can successfully take off and land the helicopter

properly via the test stand, the next phase of testing will begin. The single home property

located off of University Blvd referred to as testing location 2 will be once again utilized

during testing. This next phase still involves testing of the take off and landing

procedures. However the testing stand will be configured in a slightly different manor

which will allow for a greater altitude to be achieved. Holes for the u-bolts will be drilled

in the corners of the test stand base. The u-bolts will then be mounted to base, but this

time the helicopter

skids will not be

enclosed in the u-bolts.

Strong, but light

weight fishing wire

will be used to secure

the helicopter to the

test stand. Four

strands of 5‟-2”

fishing wire will be

needed. One end of a

length of the fishing

wire will be secured to

each u-bolt, while the

other end secured to

portions of the

helicopter skids.

Figure 5.1.3 shows the

configuration of the

stand and skids for this

stage of testing. Since

a serious crash of the

helicopter could

Page | 50

potentially jeopardize the successful completion of the project, testing in small

increments is an absolute necessity. Unlike the previous stage of testing which only

allowed the helicopter to achieve an altitude of 2” above the test stand, this stage allows

the helicopter to achieve an altitude of roughly 5‟.

The final stage for the testing of the manual flight controls of SmartCopter will occur

without the aid of the test stand. However certain precautions will still need to be

undertaken to ensure the structural integrity of the helicopter. A relatively large open

area, with a minimal amount of people is necessary for learning manual flight of the

helicopter. A large open field on the corner of University Blvd and Dean Road in

Orlando, Florida will be the location for testing of manual flight. A map and directions to

this testing location are outlined in Figure 5.12.1. The location offers adequate open area

for flight and at the same time is not heavily trafficked. The terrain is ideal for learning

manual flight due to its composition. The area is mostly grass and soft soil. This will be

beneficial in case any unfortunate crash of the helicopter occurs, due to the potential

forgiveness from the impact. This area will be referred to as testing location 1. Since

SmartCopter will not be secured to the test stand and therefore no altitude limitations, the

use of numerous blankets, sheets, and towels will be utilized. The team will square off an

area of approximately 15 feet x 15 feet, and systematically place all of the impact

absorbing materials, one on top of another, inside the squared off area. Testing of the

take off and landing procedures will take place in the center of the square. The use of the

sheets, blankets, and towels will help absorb any impact that may occur in the event of an

unexpected crash. Once manual flight is achieved by all team members, the team will

begin the process of incorporating the data recording system with the rc helicopter.

During the process of designing SmartCopter‟s flight data recording system, testing of

the system will need to occur regularly. This will aid in limiting the amount of code

and/or hardware that will need debugging or troubleshooting. Extensive testing will also

ensure the accuracy and reliability of the system as a whole. The team will test each

individual component separately, then fully integrated. Testing will begin with the

ultrasonic range finder, gyroscope, accelerometer, and GPS. Once complete, software

will be debugged, and testing will begin on the data writing to SD card interface. The

helicam and video streaming will get tested followed by a fully integrated system. It is

with extreme importance that project SmartCopter perform as expected on the day of

presentation. With rigorous amounts of testing required, additional batteries for the

helicopter, receiver, and helicam will need to be purchased. Additional testing

accommodations that will be necessary for testing are outlined in section 5.10. These

will increase the amount of time that the helicopter will be operable, creating more

productive test flight days.

5.2 Hardware Connections

In order to ensure the accuracy and functionality of the electrical components of

SmartCopter, all of the soldering connections shall be tested for solid connectivity. This

will be accomplished by utilizing the different capabilities of a 29 range digital

Page | 51

Multimeter purchased from RadioShack®. The main functions of the Multimeter that will

be needed for testing consist of the connectivity test function, DC voltage measurement,

and current measurement. The first component to be testing will be the source voltage

(Vdd) and ground connection. The circuit board shall have a source voltage of 5V DC.

The circuit board will receive its source voltage via a splice into the wiring for the

brushless motor. The motor receives its input voltage from the 11.1V Lithium Polymer

battery supplied with the helicopter. The motor purchased with the helicopter contains a

built in voltage regulator to step down the voltage from the supplied 11.1V to 5V. This is

accomplished by setting the Multimeter to measure DC voltage, and placing the positive

lead to the source voltage input of the circuit board, and the negative lead to the ground

input of the circuit board. A successful test shall yield a result of 5V. A source voltage

of 5V is required to power the microprocessor, ultrasonic range finder, and the SiRF Star

III global positioning system.

Not all of the

components of

SmartCopter need

an input voltage of

5V. A source

voltage of 3.3V will

be required to

power the

gyroscope,

accelerometer, and

the SD card

interface. Therefore

the next component

to be tested will be

the voltage

regulator that steps

down the source

voltage from 5V to

3.3V. The diagram

of the voltage

regulator to be

incorporated is depicted in Figure 5.2.1. This particular layout consisting of the various

capacitors and resistors was chosen due to its improved ripple rejection. The input

voltage tolerances of the electrical components is relatively small, therefore the layout

depicted in Figure 5.2.1 was the optimum choice.

Testing shall consist of the same technique involved in testing the source voltage of the

circuit board. The positive lead of the Multimeter will be placed on the input pin of the

LD 1117 adjustable voltage regulator, and the negative lead placed on the ground input of

the circuit board. A successful test shall yield a result of 5V. This indicates the voltage

regulator is receiving the proper input voltage of 5V. The next step will be to disconnect

the positive lead from the input of the voltage regulator and connecting it to the output

Page | 52

pin of the voltage regulator. A successful test shall yield a result of 3.3V. This indicates

the voltage regulator is functioning correctly and producing an output voltage of 3.3V.

Due to the multiple components requiring an input voltage of 3.3V, the output of the

voltage regulator will be soldered to its own supply bus bar. This will be the next area of

testing. The positive lead of the Multimeter will be disconnected from the output pin of

the voltage regulator and connected to the 3.3V bus bar. A successful test shall yield a

result of 3.3V. This confirms that any component connected to the 3.3V bus bar will be

accurately receiving an input voltage of 3.3V. After the source voltages of the circuit

board have been confirmed, the team will then transition into testing of the individual

electronic components.

5.3 Ultrasonic Range Finder

The first component to get tested will be the ultrasonic range finder. The first step to

ensure accurate readings is to visually inspect the soldering points. A loose or badly

soldered wire could result in false readings or malfunction. The ultrasonic range finder

selected for SmartCopter operates on a supply voltage of 5V. Measuring the input

voltage of the ultrasonic range finder consists of connecting the positive lead of the

Multimeter to the pin labeled “+5V” of the range finder, and the negative lead to the pin

labeled “GND” of the range finder.

A reading of 5V will confirm the

sensor is receiving the desired input

voltage. The next test to be

performed will be the continuity

check of the range finder. This is

accomplished by switching the

function dial of the Multimeter to the

continuity check, then connecting the

positive lead to the pin labeled “AN”

of the range finder and negative lead

to pin 3 of the microprocessor. The

Multimeter will buzz and display

“Shrt” if the circuit is shorted, or it

will not buzz and display “Open” if

the circuit is not shorted. The

desired readings are depicted in

Figure 5.3.1.

Next the physical component itself will be tested to confirm functionality and accuracy.

Different objects will be placed at varying predetermined distances and the output voltage

will be recorded. The analog output voltage will be measured from by placing the

positive lead of the Multimeter to the pin 3 of the microprocessor and the negative lead to

the ground bus of the circuit board. A scale factor of 9.766mV per inch is applied to the

analog output. Since the team will know the distances of the placed objects, they will be

able to calculate the expected output voltages prior to testing. The output voltage will

Page | 53

then be multiplied by 102.4 to obtain the distance in inches from the range finder to the

object. If any discrepancies in output voltage and/or distances measured are discovered,

the range finder will be removed then either reinstalled or replaced, depending on the

findings.

5.4 Gyroscope

The next component to get tested will be the gyroscope. To begin a visual inspection of

the soldering points will occur. Insufficient connections may cause the gyroscope to

malfunction, output false readings, or potentially not function completely. The gyroscope

selected for SmartCopter operates on a supply voltage of 3.3V. Measuring the input

voltage of the gyroscope consists of connecting the positive lead of the Multimeter to pin

9 labeled “VCC” of the IMU 5 Degrees of Freedom IDG500/ADXL335, and the negative

lead to pin 8 labeled “GND.” A reading of 3.3V will confirm the sensor is receiving the

desired input voltage. The next test to be performed will be the continuity check of

gyroscope‟s outputs. This is accomplished by switching the function dial of the

Multimeter to the continuity

check, then connecting the

positive lead to pin 7 of the

gyroscope labeled “XRATE”, and

the negative lead to pin 4 of the

microprocessor. The Multimeter

will buzz and display “Shrt” if the

circuit is shorted, or it will not

buzz and display “Open” if the

circuit is not shorted. The process

will be repeated by disconnecting

the positive lead of the Multimeter

and connecting it to pin 6 of the

gyroscope labeled “YRATE”, and

connecting the negative lead to pin

5 of the microprocessor. The

desired readings are depicted in

Figure 5.4.1.

5.5 Accelerometer

The next component that will need to be tested is the accelerometer. The first step to

complete is to visually inspect the soldering points. Loose connections could potentially

result in false readings or possible malfunction of the accelerometer. The accelerometer

selected for SmartCopter operates on a supply voltage of 3.3V. Measuring the input

voltage of the accelerometer consists of connecting the positive lead of the Multimeter to

pin 9 labeled “VCC” of the IMU 5 Degrees of Freedom IDG500/ADXL335, and the

Page | 54

negative lead to pin 8 labeled “GND.” A reading of 3.3V will confirm the sensor is

receiving the desired input voltage. The next test to be performed will be the continuity

check of accelerometer‟s outputs. This is accomplished by switching the function dial of

the Multimeter to the continuity check, then connecting the positive lead to pin 3 of the

accelerometer labeled “ZOUT” and the negative lead to pin 7 of the microprocessor. The

Multimeter will buzz and display “Shrt” if the circuit is shorted, or it will not buzz and

display “Open” if the circuit is not

shorted. The process will be

repeated by disconnecting the

positive lead of the Multimeter,

and connecting it to pin 2 of the

accelerometer labeled “YOUT”.

The negative lead of the

Multimeter will be connected to

pin 8 of the microprocessor. The

process will once be repeated by

disconnecting the positive lead of

the Multimeter, and connecting it

to pin 1 of the accelerometer

labeled “XOUT”. The negative lead

of the Multimeter will be

connected to pin 9 of the

microprocessor. The desired

measurements are depicted in

Figure 5.5.1.

5.6 SiRF Star III Chipset

The SiRF Star III Chipset will be the next component to get tested. Once again testing

will begin by visually inspecting all associated soldering points for solid connections.

The SiRF Star III chipset selected for

SmartCopter operates on a supply

voltage of 5V. Measuring the input

voltage of the SiRF Star III chipset

consists of connecting the positive lead

of the Multimeter to the pin 2 of the

chipset labeled “VIN” of the SiRF Star

III chipset, and the negative lead to pins

1 and 5 of the chipset labeled “GND”.

A reading of 5V will confirm the GPS

unit is receiving the desired input

voltage. The next test to be performed

will be the continuity check of the SiRF

Star III chipset. This is accomplished by

switching the function dial of the

Page | 55

Multimeter to the continuity check, then connecting the positive lead to pin 3 of the

chipset labeled “RX”, and the negative lead to pin 26 of the microprocessor. The

Multimeter will buzz and display “Shrt” if the circuit is shorted, or it will not buzz and

display “Open” if the circuit is not shorted. The process will be repeated by

disconnecting the positive lead of the Multimeter and connecting it to pin 4 of the chipset

labeled “TX”, and connecting the negative lead to pin 25 of the microprocessor. The

desired readings are depicted in Figure 5.6.1.

Additional testing of the functionality and proper will occur as well. To test the accuracy

of the SiRF Star III GPS unit, various predetermined locations will be utilized to compare

SmartCopter‟s global positioning readings with other sources of global positioning. To

begin with, the team will use Google® maps to acquire the latitude and longitude of

certain previously selected locations. The team members will then drive to these

locations and utilize another device to measure latitude and longitude coordinates. The

team will now obtain the GPS coordinates through the use of Research in Motion‟s®,

Blackberry Bold® global positioning abilities. Once at the desired destination, the

coordinates will be acquired via this method. After these coordinates are recorded, the

SiRF Star III unit will be tested. The team will record the readings from the SiRF Star III

unit. Once all location coordinates have been recorded, the team will compare all of the

results to determine the accuracy of SmartCopter‟s GPS feature. A successful test will

yield results within 200m between all the recorded locations.

5.7 HeliCam

After testing of the SiRF Star III chipset has commenced, the team with then test the

function of the 2.4GHz wireless HeliCam. The camera operates on a 9V battery, and

transmits the video wirelessly to a supplied transmitter. Testing of the helicam with be

quite simple. The 9V battery will be connected to the camera, and the transmitter will be

connected to a television through the use of an RCA cable. If the camera operates with

minimal intereference, it will be incorporated into the base station computer. The base

station computer will have a video tuner card installed to allow for an RF cable

connection. The helicam with then be connected to a Super NES® RCA to RF video

converter. The Super NES® RF will get connected to the RF connector of the video tuner

card installed in the base station computer. A successful test will record the video

streaming from the camera to memory on the base station.

5.8 SD Card Interface

The last component that will need to be tested is the SD card interface. The first step to

complete is to visually inspect the soldering points. This particular component has the

most connections that must be inspected. Since the data needs to be accurately recorded,

loose or inadequate connections must be redone. The SD card interface selected for

SmartCopter operates on a supply voltage of 3.3V. Measuring the input voltage of the

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SD card interface consists of

connecting the positive lead of the

Multimeter to pin 1 of the SD card

breakout board labeled “CS and the

negative lead to pin 5 labeled

“GND.” A reading of 3.3V will

confirm the pin is receiving the

desired input voltage. This same test

will then be performed on pins 2, 3,

4, 6, and 7 labeled, “DI”, “VCC”,

“CLK”, “DO”, “IRQ”, and “P9”

respectively. A desired reading of

3.3V will yield a successful test. This

will confirm that the SD card

breakout board is receiving proper

input voltage for operation. The

desired results for the input voltage at

the desired pins of the SD card

breakout board are displayed in

Figure 5.8.1.

The next test to be performed will be the continuity check of SD card breakout board

outputs. This is accomplished by switching the function dial of the Multimeter to the

continuity check, then connecting the positive lead to pin 1 of the SD card breakout board

labeled “CS” and the negative lead to pin 35 of the microprocessor. The Multimeter will

buzz and display

“Shrt” if the

circuit is shorted,

or it will not buzz

and display

“Open” if the

circuit is not

shorted. The

process will be

repeated by

disconnecting the

positive lead of the

Multimeter, and

connecting it to

pin 2 of the SD

card breakout

board labeled

“DI”. The

negative lead of

the Multimeter

will be connected

Page | 57

to pin 37 of the microprocessor. This test will be performed from pin 4 of the SD card

breakout board labeled “CLK” to pin 34 of the microprocessor. Then it will be perform

from pin 6 of the SD card breakout board labeled “DO” to pin 33 of the microprocessor.

Next it will be perform from pin 9 of the SD card breakout board labeled “CO” to pin 39

of the microprocessor. Finally the last continuity test will be performed from pin 10 of

the SD card breakout board to pin 40 of the microprocessor. The desired results are

depicted in Figure 5.8.2.

Once all of the connections have been tested for adequate input voltage and proper

connectivity, the team will begin testing of writing the data to the SD card. The first data

entry that will be written to the SD card will be the data output from the ultrasonic range

finder. Since previous measurements were taken for the range finder, the team will know

if the data written to the SD card was done so correctly. If the recorded data is the same

as was expected, the team will know that writing to the SD card is occurring. This will

ensure that all of the connections correct and that the associated software functioning. At

this point it is not necessary that the software for writing all of the other data to the SD

card is entirely correct. This at least shows the team that they are on the right track in

terms of software and hardware.

After the initial data has been written to the SD card, data from the SiRF Star III chipset

will get written to the SD card. The data will be compared to the previously measured

global positioning coordinates. A successful test will yield the same latitude and

longitude coordinates as was recorded from the known GPS locations. From this point,

similar tests will be done for the accelerometer and gyroscope. Initial tests for the

accelerometer and gyroscope readings will be done via a “hand flown” method.

Essentially the team will perform the tests without the platform of the helicopter. One

team member will simulate the helicopter flight characteristics by moving the circuit

board through the air. The SD card will be removed and the results will be obtained. A

successful test will record all of the desired results from the various components of

SmartCopter.

5.9 Fully Integrated System

Once manual flight testing and the various electrical component testing have been

complete, testing of the data recording system has a whole will occur. This stage of

testing is just as critical as the previous stage. Just as before, testing will occur in

incremental steps. This will allow for a narrower scope to troubleshoot in case an error

does take place. Initial testing for data recording system of SmartCopter will take place

at the previously selected area on the corner of University Blvd and Dean Road, referred

to as testing location 1. This location provides ample space with minimal interference.

The area is also in close relation to the homes of two of team SmartCopter‟s members as

well as the University of Central Florida. This will prove beneficial for the transportation

of all the necessary equipment, and in the event where redesign must occur. Testing of

the fully incorporated system will only commence after the team is fully confident they

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can manually fly the helicopter, and after all of the individual components have been

tested.

In order to properly test the accuracy of the data recording system the team will need to

test each aspect of the

controls one step at a

time. This is crucial

in troubleshooting any

problem that may

arise during testing.

Due to the potential

financial impact and

loss of completed

work, the team must

take every

precautionary tactic

possible to avoid any

type of crash. The

team must also take

care not to physically

lose SmartCopter.

This could be a

possibility in the event

the unit strays off

course. If the team

were to lose visibility

and not be able to recover the unit, this could be ended up causing a failure of the project.

At this point in time, the team has put forth a relentless and time consuming effort, and

failure is not an option. For this phase of testing, the team will once again utilize the test

stand as configured in Figure 5.9.1.

The location for this test will again take place at testing location 1. A map and directions

are shown in Figure 5.12.2. After all the necessary setup is complete, testing of the fully

integrated SmartCopter system will begin. Testing for the fully integrated system will be

similar to testing of the manual flight controls of the helicopter. Due to the additional

weight and different balancing points, the team will need to familiarize themselves with

the altered flight characteristics of the helicopter. Manual flight will occur with the

fishing line tethered to test stand, and the helicopter attached to the line as similar to

previous testing. Each team member will take turns learning and observing how different

the helicopter‟s flight is altered. After the new flight characteristics are studied, and

adjustments made, SmartCopter will be ready to commence its final test. This will be a

test of the entire SmartCopter system without the aid of any test stand or tethering. Since

SmartCopter will not be secured to the test stand and therefore no altitude limitations, the

use of numerous blankets, sheets, and towels will once again be utilized. The team will

square off an area of approximately 15 feet x 15 feet, and systematically place all of the

impact absorbing materials, one on top of another, inside the squared off area. Testing of

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the fully incorporated system will take place in the center of the square. The use of the

sheets, blankets, and towels will help absorb any impact that may occur in the event of an

unexpected crash. The team will manually fly SmartCopter, while SmartCopter‟s data

recording system records the data to the SD card, and wirelessly transmits the video of

the flight. A successful test will include proper and accurate writing of all the necessary

components to the SD card while simultaneously transmitting a video feed wirelessly to

the base station.

5.10 Testing Accommodations

In order to maximize the productivity and efficiency of all testing days, certain

accommodations must be addressed. These issues include the acquisition of necessary

testing supplies as well as non-essential supplies. Once acquired the transportation and

storage of all project related materials will need to be coordinated. The first process that

needs to occur for testing is acquiring all of the supplies and materials needed for testing.

The items needed to construct the test stand as well as a carrying case, which will be

described later in this section, will be purchased from the local Home Depot store. This

includes all the necessary lumbar and hardware. The stand will be constructed by team

member Brian Williams with the aid of a family member. The location for the

fabrication of the stand and carrying case, along with the use of all the required tools that

are needed for construction, will be supplied by the aforementioned family member. This

will incur no additional cost to the project.

Along with the materials for the stand and case, various tools will be needed throughout

the duration of the project. These tools will be on loan to the team by project member

Brian Williams. In the event that additional tools are required, the attempt to obtain the

tools via resources that will not increase the cost of the project will be made. If the tools

cannot be gathered, the sponsorship funding will cover the cost to purchase them. All of

the blankets, sheets, and towels that will be utilized for testing will be donated to the team

via the team members themselves. Along with the necessary items required for testing,

some non-essential items will need to be acquired as well. Non-essential test items

include items that are not needed for testing, but will ultimately increase the overall

efficiency on test days. Some of these items include an additional battery for the

helicopter and extra batteries for operation of the transceiver during manual flight testing.

This will allow the team to have a longer run time of the helicopter. Proper

accommodations such as electricity, computer availability, and close proximity to a

covered facility will also prove viable resources during testing. Close proximity to

shelter will benefit the team in the event of a sudden change of the weather conditions.

After all of the materials and supplies have been acquired, the issues of storage and

transportation become a concern. Storage of all the testing stand and tools will be the

responsibility of team member Brian Williams. Since initial testing of the integrated data

recording system of SmartCopter will take place at the house of a relative of Brian

Williams, the testing materials will be stored at that location. Storing the supplies and

materials for the project will ultimately expedite the testing procedures as transportation

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of the materials will not need to occur. Testing at this facility is available at any given

time to project SmartCopter.

The last issue to be addressed is that of the transportation of all the needed materials,

tools, equipment, and SmartCopter itself. Due to the sensitive nature of the helicopter,

and the need for as few setbacks as possible, the helicopter needs to be protected during

all times during transportation and storage. A carrying case previously addressed will be

constructed for use during transportation. The design of the carrying case is depicted in

Figure 5.10.1.

[2]

Figure 5.10.1

SmartCopter carrying case

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The case will be made of some of the same materials used for the test stand. These

include sheets of 2” plywood, hinges, screws, u-bolts, and nuts. The fabrication of the

carrying case will be completed by team member Brian Williams. The design of the case

is a simple design that secures the helicopter in place, while at the same time protecting it

from outside forces. It relies on 4 hinges fastened to the base and the two long sides.

This permits two sides to fold down allowing for easy placement of the helicopter inside.

The helicopter will be secured to the base in a similar fashion to the testing stand.

However during storage and transportation, the u-bolts will be completely tightened to

the skids of the helicopter. This is depicted in an enlarged view of the carrying case base

shown if Figure 5.10.2.

This will prevent any movement inside of the case. The two shorter sides will be

securely fastened to the base of the carrying case as they will not be on hinges. The top

of the case will then be placed on top of the assembled portion and tightly secured with

the use of eight hand tightening wood screws. Transportation of SmartCopter along with

all of the necessary supplies and tools will mainly be the responsibility of team member

Brian Williams. This team member has a vehicle that contains ample storage for the safe

transport of SmartCopter and all project related materials.

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5.11 Detailed Plans

The following plan depicted in Figure 5.11.1 is for the construction of the test stand.

[2]

Figure 5.11.1 Test stand

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The following plan depicted in Figure 5.11.2 is for the construction of the carrying case.

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5.12 TESTING LOCATIONS

The following map shown in Figure 5.12.1 is referring to testing location 1. The location

was chosen due to its adequate open area for flight and at the same time is not heavily

trafficked. The terrain is ideal for learning manual flight due to its composition. The

area is mostly grass and soft soil. This will be beneficial in case any unfortunate crash of

the helicopter occurs, due to the potential forgiveness from the impact.

[2]

Figure 5.12.1 Map of testing location 1 on the corner

of University Blvd and Dean Road

DIRECTIONS:

From the University of Central Florida, head west on University Blvd.

At Dean Road intersection head north on Dean Road.

Testing location is located on west side of Dean Road.

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The following map shown in Figure 5.12.2 is referring to testing location 2. The location

was chosen due to the relationship to team member Brian Williams. The location is in

close relation to the University of Central Florida as well as Brian‟s home as well as the

home of Matthew Campbell.

[2]

Figure 5.12.2 Map of testing location 2

off University Blvd

DIRECTIONS:

From the University of Central Florida, head west on University Blvd.

At Suncrest Blvd intersection head south on Suncrest Blvd.

Head east on Cherry Oak Circle, then north

End at physical address 10529 Cherry Oak Circle

Location is on west side of Cherry Oak Circle

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The following map shown in Figure 5.12.3 is referring to an alternate testing location in

case the other two locations are unavailable during the time needed. The location was

chosen due to its adequate open area for flight and at the same time is not heavily

trafficked. The terrain is similar to that of testing location 1.

[2]

Figure 5.12.3 Map of possible testing location 3

DIRECTIONS:

From the University of Central Florida, head west on University Blvd.

At the intersection of University Blvd and Goldenrod Road head south on

Goldenrod Road.

Location is on east side of Goldenrod Road.

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Chapter 6: Mounting Hardware

To accommodate for all of the necessary electrical components that SmartCopter shall

contain a necessary mounting plate to house all of the hardware. The following

depictions in Figure 6.1.1 and Figure 6.1.2 show the layout of the proposed mounting

hardware. Due to size limitations and constraints, a custom mounting plate will need to

be fabricated. The dimensions of the skid plate are unique to the model of helicopter

purchased; therefore no enclosures that are in production that have the required area

needed.

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Chapter 7: Future Project Upgrade Possibilities

7.1 Potential Uses

One of the purposes for project SmartCopter is to eventually integrate SmartCopter‟s data

recording system into an autonomous piloting system. The team will be able to utilize

the data recorded to provide the necessary software in order to achieve this feature. Now

visualize a world where an aircraft is able to change the way we retrieve information in

our daily life. Whether it is military based, traffic inspection or life or death

circumstances, the SmartCopter is what is needed to manage the situation with ease. This

lightweight, GPS regulated aircraft is designed to travel to a pre-programmed GPS point

with the purpose of taking still images at that time and location.

When it comes to military tactics, taking precaution is a must in the safety of our troops.

With the SmartCopter at hand our troops are able to find new ways to take on a mission

without the dangers of taking unnecessary risks. With the ability to take pictures from an

inconspicuous view, through camps or over the swampy terrain, the military will have

advantages that have never been available before.

Dealing with conditions that involve crowds of people has a higher risk of ending in

madness and disarray. When it comes to big events, festivities or even protests, it is a

huge advantage to get a bird‟s eye view of the conditions at that event. With the

SmartCopter, these situations can be controlled and managed to prevent chaos and

possible injury through its ability to photograph the crowd settings of the programmed

GPS location. Returning with these snap shots of the crowd range, crowd shift or maybe

even criminal acts being achieved will give the outsiders an upper hand in maintaining

peace in these testy situations.

In the occurrence of a package or unidentified object is under suspicion of foul play, the

standard routine is to send a workforce in to investigate the situation at hand. However,

with the SmartCopter, this is no longer a risky operation. Say that a call comes in for a

suspicious package, the area is cleared of all civilians, and the risk is too high to send in

staff. Simply send off the SmartCopter to investigate through pictures either close up or

from a distance and return to unharmed personnel to take action accordingly. With no

individuals harmed, and now information on the package, it is easy to see why this device

is essential in risky situations.

A life or death situation is the most crucial of all. A lot of times our law enforcement are

required to operate risky tasks in order to save a life in a rescue mission. With the

SmartCopter, rescue procedures have never been so safe and premeditated. Over high

cliffs, mucky waters or dangerous areas of our earth, the SmartCopter is able to get a

clear view of what is going on around it in order for our people to make a safe planned

route of rescue.

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With life or death in mind, another trivial threat is fires. Raging flames, whether from a

house or in nature, create major damage and are one of the most dangerous natural

disasters to be contained. Say a house is on fire and the situation is being evaluated, the

SmartCopter can easily act as a third eye for assessment.

Whether inside the house collecting pictures of the fire sources or hovering above to seek

the areas of crucial concern, the device is playing a part in the rescue through the heavy

smoke and flames. In addition to the SmartCopter assisting during a fire, it is also capable

of aiding in the aftermath of a fire.

The debris after a fire is put out can be dangerous in more ways than one. The heavy ash

all around and remaining smoke is a hazard to workers searching the ruins. But with the

knowledge of the overall remnants before venturing onto the scene, injury may be

prevented and game plans can be assessed.

Aside from disastrous conditions, the SmartCopter is also beneficial for relaying

information on a concern that we battle everyday, traffic. The every morning and

afternoon fight to beat or avoid traffic can be averted with the helpful knowledge of

alternate routes, or even specific areas to steer clear of at that exact moment. If this

everyday nuisance can be prevented in anyway, the SmartCopter‟s job is achieved.

7.2 Multi-Helicopter Coordination

With the apparent limitless potential uses of project SmartCopter, and the great impact

that a single unit could have on human life, it would only seem logical that multiple

SmartCopters working in coordination with one another would be able to have an even

greater impact on the quality of life. The range and potential life saving abilities of a

team of SmartCopters would be extraordinary. There are many different situations in

which a group of SmartCopters would be more beneficial than a single SmartCopter.

With the ever increasing threat of natural and manmade disasters, precautions need to be

undertaken to ensure that minimal amount of human exposure to these situations occur.

One example of this would be the extremely dangerous threat of wildfires. A wildfire

can spread over a vast area of forest, and can be extremely hard to handle.

One of the problems fire fighters have to deal with when fighting large wildfires, is

knowing the extent of the size of the fire. A team of SmartCopters would be capable of

surveying the disaster area without risking any human exposure to the actual fire or

smoke.

Another possible use for a team of SmartCopters would be in the event of another

terrorist attack. The horrific attacks that took place on September 11, 2001 on the Twin

Towers in New York City, opened up everybody‟s eyes to the realization that ultimately

nobody is safe. The United States government has taken the best precautions possible to

ensure this does not happen again. However there is always a chance.

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In the unfortunate event, that another attack occurs on the United States, a team of

SmartCopters would be able to survey damage almost immediately. This would greatly

increase the survival rate of such an attack. One of the major hurdles the rescuers faced

was their ability to locate remaining survivors. The amount of debris that was released as

a result of the falling of the Twin Towers was unimaginable. This severely limited the

mobility and capabilities of the search teams. A team of SmartCopters would be able to

survey the attack site, and relay vital information to the rescue team way before they

even stepped foot on the site. With the incorporation of infrared sensors, SmartCopter

would even have the capability of locating survivors trapped under a pile of fallen rubble.

With the incorporation of multiple SmartCopters into a single team, many obstacles

would need to be overcome to avoid any potential collisions. The major one would be

communication amongst all the individual units. Each unit would need to have the ability

to relay vital information about their position and altitude.

The biggest problem with that is the ability to communicate instantly. With all

communications there is a slight delay from the time a signal is sent, to the time it is

received. The amount of delay is a direct correlation with the type of technology used.

Back in the days of the Space Race and the first landing on the moon, this was obviously

apparent. Due to the great distance between the Earth and the moon, it would take a little

extra time for a radio wave to reach the moon and back.

The great distance between the earth and the moon caused a slight delay in

communication between Houston and the astronauts. As time passed along and

technology progressed, solutions to these delays were found. The solution to this is what

is known as Real Time Communication. Real Time Communication is communication

where information can be transmitted and received instantly or with seemingly negligible

delay.

Chapter 8: Timeline

The objective for the first semester consisted of establishing a group, and working

together to complete the appropriate documentation. Our time was spent conducting

research, meetings, and building our design. The table consists of completed tasks and

meetings for each week during the first semester.

The second semester consisted of building and testing the SmartCopter, reviewing design

statistics, completing it and presenting it. The goal was to have it completed by

Thanksgiving break.

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Month

Objective

May

Choose project design idea, Commence

project research

June

Continue research, find sponsors, research

work divided amongst group members

July

Research parts and compare, present SD1

presentation

August

Modify design criteria

September

Order parts, commence software

development, begin copter stabilization

and learn copter operations using flight

simulation, begin testing hardware

components

October

Modify design, begin programming

microcontroller, commence GPS

Guidance System (hardware & software),

hardware

November

Complete hardware system, implement

software, establish test sight, test flight

operations (time permitted), combine

hardware and software components

December

Final week and final presentation,

complete project, fix encountered errors

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Chapter 9: Budget

9.1 Parts List

This chapter contains a tentative list of the parts SmartCopter will need, and it provides

descriptions for each, as well as photos which have been provided by Sparkfun.com.

Part Price per

Unit ($)

Quantity Total

($)

Esky Belt-CP 450 RC Helicopter 200.00 1 200.00

PIC 40 Pin 48MHz 16K 13 Channel A/D USB-

18F4610

11.39 1 11.39

Ultrasonic Range Finder – Maxbotix LV – EZ2 27.95 1 27.95

Triple Axis Accelerometer Breakout – ADXL 330 34.95 1 34.95

Gyro Breakout Board – Dual 500 degree/sec 59.95 1 59.95

20 Channel EM – 406A SiRF III Receiver with

Antenna

59.95 1 59.95

2.4Ghz HeliCam 39.95 1 39.95

I. Esky Belt-CP 450 RC Helicopter

This helicopter has a 6-channel brushless radio. It contains a belt-driven tail rotor

vibration free, and offers smoother tail control. It‟s perfect for indoor or outdoor use. It‟s

capable of flying backward, skyway, and 3D aerobic.

Length: 650mm (26 inch)

Height: 230mm (9 inch)

Flying Weight: 670g (24 oz)

II. PIC 40 Pin 48MHz 16K 13 Channel A/D USB – 18F4610

The PIC Micrcontroller uses a full speed USB 2.0 interface. It‟s perfect for low power

outage. The 18F4610:

16k of flash

12 MIPs (Microprocessor without Interlocked Pipeline Stages)

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III. The Ultrasonic Range Finder – Maxbotix LV-EZ2

It offers an admirable size and decent quality. It can control up to 10 sensors with just 2

pins. Specs:

42kHz Ultrasonic sensor

Operates from 2.5-5.5V

Low 2mA supply current

20Hz reading rate

RS232 Serial Output – 9600bps

Analog Output – 10mV/inch

PWM Output – 147uS/inch

Small, light weight

VI. Compass Module – HMC6352

A simple breakout board for the popular HMC6352, it provides a ready to use electronic

compass that combines 2-axis magneto-resistive sensors, analog and digital support

circuits, and heading computation algorithms.

Simple I2C interface

2.7 to 5.2V supply range

1 to 20hz selectable update rate

True drop-in solution

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0.5 degree heading resolution

1 degree repeatability

Supply current: 1mA@3V

V. Triple Axis Accelerometer Breakout – ADXL330

This breakout board from Analog Devices provides a low noise and power consumption

experience.

Dimensions: 0.7 x .7”

VI. Gyro Breakout Board – Dual 500 degree/sec

The IDG-300 has a smaller profile than some single axis gyros, it‟s also cost efficient. It

offers high temperature and humidity resistance.

Integrated X- and Y-axis gyro on a single chip

Low offset voltage

Integrated low-pass filters

Integrated reset switches for high-pass filters

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Superior vibration rejection over a wide frequency range

High cross-axis isolation by design

3V single supply operation

5000 g shock tolerance

RoHS Compliant (Completely Lead free)

VII. 20 Channel EM-406A SiRF III Receiver with Antenna

This module includes on-board voltage regulation, LED status indicator, and a built-in

patch antenna.

Weight: 16g including cable

20-Channel Receiver

Extremely high sensitivity: -159dbm

Smallest complete module available: 30mm x 30mm x 10.5mm

Outputs NMEA 0183 and SiRF binary protocol

70mA at 4.5-6.5V

Cold Start: 42s

Warm Start: 38s

Hot Start: 1s

10m Positional Accuracy/5m with WAAS

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VIII. 2.4GHz HeliCcam

A micro wireless video camera

Camera and transmitter weight: 9 grams

Camera and transmitter size: 15mm x 22mm x 32mm ((5/8" x 7/8"

x 1 1/4")

Camera Lux: < 3 @ f1.2

Camera Auto Electronic Exposure of 1/60 to 1/15000 sec. w/Auto

Gain & White Balance

Camera Signal to Noise Ratio: > 48dB

365K (PAL) or 250K(NTSC) camera pixel resolution

Wireless Transmission Range: 150M (450 Feet), Line-of-sight

Transmitter RF Output Power: EC R & TTE Compliant

Receiver Video Input/Output: 1Vp-p/75 ohm

IX. IMU 5 Degrees of Freedom

This PCB board incorporates the IDG300 dual-axis gyroscope and Analog Devices

Dimensions: 0.75” x 0.9” (20 x 23mm)

Weight: 2g

9.2 Funding

Funding will be provided by Nelson Engineering Co. of Merritt Island, Florida and

Rogers, LoveLock, and Fritz Architecture. The budget presented at the beginning of this

section is the basis of what SmartCopter will require. Additional parts not included may

be purchased as well. Both benefactors will sponsor equal amounts of funding. The

present purchasing plan consists of purchasing the parts individually and receiving

reimbursement at the appropriate time.

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Chapter 10: Conclusion

The team behind the project SmartCopter utilized knowledge gained from various

disciplines in the fields of Computer Science and Electrical Engineering to complete their

design. SmartCopter will be a device that records flight data such as acceleration,

rotation, current heading and current video while being mounted beneath a RC helicopter.

Page | 79

Chapter 11: Appendix

References:

[1] Anderson, John D. (2004), Introduction to Flight (5th ed.), McGraw-Hill, pp. 257–

261, ISBN 0-07-282569-3

[2] Padfield, Gareth D. (2007), Helicopter Flight Dynamics (2nd

ed), Wiley-Blackwell,

pg. 92 ISBN 978-1-4051-1817-0

[3] Heffley, R. K. & Mnich, M. A. (1988), Minimum-Complexity Helicopter Simulation

Math Model, NASA.

[4] Bak, T. [2002], Modeling of Mechanical Systems,

http://www.control.auc.dk/~jan/undervisning/MechanicsI/mechbook.pdf

[5] Wie, B. [1998], Space Vehicle Dynamics and Control, AIAA Educational Series. 110

[6] Hald, Ulrik B. , Autonomous Helicopter Modeling and Control, Aalborg University

[7] Leishman, Gordon J. (2002), Principles of Helicopter Aerodynamics, Cambridge

University Press

[8] Johnson, Wayne. Helicopter Theory, Dover Publications

[9] http://www.xheli.com/wa4chdr53cor.html

[10] http://ww1.microchip.com/downloads/en/DeviceDoc/39632D.pdf

[11] http://www.sparkfun.com/datasheets/GPS/NMEA%20Reference%20Manual1.pdf

[12] http://www.sparkfun.com/datasheets/Components/HMC6352.pdf

[13] Nguyen, Hung T. Fuzzy Modeling and Control, CRC Press

[14] http://www.ngs.noaa.gov/FGCS/info/sans_SA/docs/statement.html

[15] http://www.sparkfun.com/datasheets/GPS/EM-406A_User_Manual.PDF

[16] Courtesy of Brian Williams via Autodesk program Revit MEP 2009

[17] Courtesy of Brian Williams via Autodesk program Revit MEP 2009, and open

source google images

[18] “military aircraft.” Encyclopaedia Britannica. 2009. Encyclopaedia Britannica

Online. 09 Aug. 2009 http://britannica.com/EBchecked/topic/382295/military-aircraft

[19] http://www.dragonflyx6.com.html

Page | 80

Bibliography

1) http://heli.stanford.edu/papers/AbbeelCoatesHunterNg_aaoarch_iser2008.pdf

2) http://www.cs.cmu.edu/afs/cs/project/chopper/www/goals.html

3) http://www.draganfly.com/uav-helicopter/draganflyer-x6/applications/

4) http://www.grandhobby.com/exrcre4503d6.html

5) http://electronics.howstuffworks.com/brushless-motor.htm

6) http://www.omega.com/prodinfo/accelerometers.html

7) http://www.rctoys.com/

8) http://www.rchelicopter.com/

9) http://www.slickzero.com/

10) http://www.acroname.com/robotics/info/articles/devantech/srf.html

11) http://www.parallax.com/dl/docs/prod/acc/PingDocs.pdf

12) http://www.hobbyengineering.com/H2951.html

13) http://www.sparkfun.com/

14) http://www.xheli.com/

15) http://www.servocity.com/html/hitec_servos.html

16) http://www.epanorama.net/documents/motor/rcservos.html

17) http://en.wikipedia.org/wiki/Main_Page

18) http://www.seattlerobotics.org/guide/servos.html

19) http://www.rchelicoptertips.com/rc-heli-beginners/rc-heli-gyro/

20) http://www.rchelicopterfun.com/rc-helicopter-gyro.html

21) http://www.heliproz.com/jwgyros.html

22) http://www.electric-rc-helicopter.com/article/gyroconfusion.php

23) http://www.dimensionengineering.com/accelerometers.htm

24) http://www.magneticsensors.com/gpssolutions.html

25) http://www.proxdynamics.com/images/uploads/Proxflyer-UVS-04.pdf

26) http://www.gpsreview.net/electronic-compass/

---------- Forwarded message ----------

From: Boe AnnDrea <anndrea@sparkfun.com> Date: Tue, Jul 28, 2009 at 4:55 PM

Subject: Re: Permission to use Pictures

To: Allie Rolle <allieboo13@gmail.com>

Hello Alvilda Rolle!

Yes you may use our photos for your senior project. Thank you for asking, and good luck with

Page | 81

your project.

Best,

AnnDrea Boe

__

Director of Marketing Communications SparkFun Electronics

6175 Longbow Drive, Suite 200 Boulder, CO 80301

On Jul 28, 2009, at 2:08 PM, Allie Rolle wrote:

To Whom It May Concern

My name is Alvilda Rolle. My group and I are currently working on a senior design project through the University of Central Florida. I would like to obtain your permission to use photos

from your website please. Thank you for your reponse concerning this matter. Sincerely,

A. Rolle

--

~Allie~

HighLevelController: /*Store series of waypoints as a linked list*/ struct waypoint { struct GPS_position* target; int lingerTime; float lingerHeading; struct waypoint* nextWaypoint; }; struct GPS_position* myPosition; struct waypoint* currentWaypoint; //Calculates desired heading float calcHeading(struct GPS_position* current,struct GPS_position* target); /*Converts string read by USBController to GPS cooridnates*/ struct waypoint* parseWaypointFile(char* str); int main() { GPSController:intiGPS

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char* str = USBController:readFile currentWaypoint = parseWaypointFile LowLVLFlightController.setMode(TAKE_OFF) while(currentWaypoint != NULL) { LowLVLFlightController.setHeading(calcHeading(...)) LowLVLFlightController.setMode(TRAVEL_TO) while(GPSController:comparePosition(from,to) != 0) { LowLVLFlightController.step(); GPSController:updateGPS myPos = GPSController:getPosition } LowLVL.setHeading(lingerHeading) LowLVL.setMode(HOVER) while(lingerTime < timer) { LowLVL.step() timer++ } currentWaypoint = currentWaypoint->nextWaypoint } LowLVL.setMode(LAND) return 0; } LowLevelController: #define TAKE_OFF 0 #define HOVER 1 #define TRAVEL_TO 2 #define LAND 3 int currentMode; float x; float y; float z; float dx; float dy; float dz; float ddx; float ddy; float ddz; float theta; float omega; float psi; float thetadot; float omegadot; float psidot;

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float thetadotdot; float omegadotdot; float psidotdot; void setHeading(float heading); void setMode(int mode); void step() { switch mode: case 0: takeoff() break; case 1: hover() break; case 2: travelto() break; case 3: land() break; } //Takes control until mode is finshed. void takeoff() void land() //Samples sensors each iteration and corrects as necessary void hover() void travelto() USBController: //starts usb device void init() //stops usb device void destroy() //reads waypointfile char* readFile(char* fname); ServoController: float u_col; float u_long; float u_lat; float u_tail; void setUCol(float ucol); void setULong(float ulong); void setULat(float ulat); void setUTail(float utail); float getUCol(); float getULong(); float getULat();

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float getUTail(); void output(int direction); MotorController: float myRPM; void setRPM(float rpm) float getRPM() GPSController: struct GPS_position { float latitude; float longitude; float altitude; }; struct GPS_position* currentPosition; void updateGPS(); struct GPS_position* getPosition(); char* getGPSOutput(); void parseGPSString(char* str,float* lat,float* longi,float* alt); //Compares two GPS points and returns the range between the two int comparePosition(struct GPS_position* p1,struct GPS_position* p2); CompassController: float myHeading; init() updateHeading() float getHeading()