Team Blackbird 09’ UAS Project Description

Team Members

Randy Breingan, Jerson Mezquita, Michael Fabula

Faculty Advisors:

Dr. Massood Towhidnejad

Submitted:

May 27, 2009

Proof of Flight Statement: We certify that the Unmanned Aerial Vehicle described in this paper has undergone a fully

autonomous test flight.

I. Abstract

For the 2009 Student Unmanned Aerial Systems Competition, The Embry-Riddle

Aeronautical University’s (ERAU) Team Blackbird decided to start from square one and

design a system from the start that worked best for the team and its members. Due to the

fact that last year's system was overly complicated because of the number of subsystems

that were interdependent (see Blackbird 2008 Journal Paper), the team required a simplistic

approach that reduces setup time and human interaction. Using a quality function

deployment systems engineering approach, Team Blackbird has designed an airframe

around the system rather than a system dependent on the airframe. This allows for a

greater degree of adaptability which will be applied to future competitions and future

successes. The current team goals warranted the use of both a simplistic and safe system.

Therefore, the new system is fully electric, operating off of custom A123 battery packs; a

tried-and-true autopilot, the Piccolo II; and streaming digital video from an Axis 207MW

camera with a 1 Watt amplifier. Based on the team's experience along with resources

available, this systems approach was the most cost effective way of producing the quality

intelligence required by the mission statement.

II. Introduction

Team Blackbird has gone through radical roster changes since last year, resulting in a

completely new team comprised of two freshmen and one junior. The team members are

enrolled in Mechanical, Software and the Aerospace Engineering programs respectively. Due

to the nature of the new team, it was concluded that a two-year plan should be enacted to

achieve the greatest results. The team investigated the strengths and weaknesses of the

each of the teams from last year in order to emulate and originate a successful system.

Quality function deployment (QFD) was then used to generate the relationship between the

competition goals and design parameters. The result of the QFD is the optimal correlation to

be used in the systems design process. The Team has decided to currently focus primarily

on composite materials testing and the electronics system which includes the targeting and

autopilot subsystems, leaving advanced airframe construction for next year. This will allow

us to compete sufficiently in both the 2009 and 2010 competitions.

III. Development Process

Approach

Team Blackbird began its development process similar to last year's, by using Alistair

Cockburn's Crystal Clear Methodology [1]. Cockburn summarizes his ten years of research

into successful software teams into seven properties.

• Frequent Delivery- incremental software updates to client or a test workstation

• Reflective Improvement- Periodic project retrospection

• Osmotic Communication- co-location of team members

• Personal Safety- fostering good team member relationships

• Focus- Team members should know the top two priorities at all times; no person

working on more than one and one-half projects simultaneously

• Easy Access to Expert Users- semi-weekly meetings or co-location of expert advice

• Technical Environment- automated tests, configuration management and frequent

integration

For 2009 the Blackbird Team works on weekly deadlines with tasks clearly listed on

whiteboards. Progress made is tested frequently and members work in the same lab with

advice from a graduate student adviser. The team works as a single unit and not a cluster of

individuals which allows greater achievements to be made than one with many more

members. Cockburn's approach applied together with issue tables and quality research has

allowed Team Blackbird’s system engineering a greater chance of success in this year's

mission.

Quality Goals

To ensure the greatest quantity of progress while maximizing project quality, Team

Blackbird relied on Quality Function Deployment. QFD is a “method to transform user

demands into design quality, to deploy the functions forming quality and to deploy methods

for achieving the design quality into subsystems and component parts and ultimately to

specific elements of the manufacturing process.” [2] QFD has been an integral part of the

Japanese car manufacturing process since 1972 and has seen use in the United States after

1983. The Joint Strike Fighter F-35 and Joint Advanced Strike Technology (JAST) program

also use QFD. A brief overview of the QFD procedure is seen below.

The standardized graphical approach to QFD is a House of Quality (HOQ). The HOQ is a

planning matrix that correlates customer desires with the methods that a producer has to

meet them. The customer needs were determined based on the cash barrel rewards and

judging rubrics. Additional needs were based upon Team Blackbird's quality goals of safety,

simplicity, repeatability, performance and maintainability, in order of importance.

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The HOQ, above, determined both the quality characteristics that should be focused on in

the system and their weighted percentage of importance to meeting the customer’s needs. The most important characteristics and their weights are:

Attribute Percentage Importance

User interface ease of use 16.0%

Motor type 15.9%

Autopilot reliability 14.9%

Autopilot autonomous accuracy

12.4%

Image resolution 10.2%

Assembly time 8.0%

Tensile strength of Material 6.3%

Although quite surprising, the results demonstrate the necessity of the QFD process.

Rationally, one should come to the conclusion that image resolution would be the most

important characteristic for a system competing in targeting exercises. However, this is not the case. The HOQ on the first level compares relationships between the competition goals

and Team Blackbird's quality goals. The second level is the relationship between our quality

goals and system characteristics to meet them. The results from the House of Quality diagram can be compared and connections between the different areas can be established.

The “user interface ease of use” attribute of the system was determined to be the most important because it is integral to the speed and accuracy of the system’s ability to return

intelligence. The motor type was second in importance because of the cost per vehicle, ease

of operation, aircraft endurance, performance and vibration (in relation to image quality). Both autopilot reliability and autonomous accuracy have strong relationships to autopilot

selection. It turned out that image quality was only necessary for identifying all target

characteristics of one target during flight and locating and identifying a realistic pop-up target, both of which combined are scored less than autonomous navigation. A number of

factors affect the system set up time prior to flight including the autopilot and its operation

set up, complexity and the number of parts for the overall system. The strength of a material, specifically it’s tensile strength, is important to factor into the design process

because it affects the price of the materials and the survivability factor which contributes to

the mean time between failures. The QFD showed that image quality should not be at the forefront of the design process, which is contradictory to what the team had originally

anticipated. Therefore quality function deployment, systems engineering, and the House of Quality have become an integral part of the planning aspect of this year’s design process.

Issue Tables

Issue Table 1: System Complexity o Quality Goals: This issue is directly related to three of our quality goals. They are:

safety, simplicity and survivability. o Description: The metric for determining system complexity is the number of people

required to operate system at optimal performance. The number of points that the

team will receive is related to the number of persons on the team and it is also related to the time that it takes for the team to complete the task. The number of

team members required to operate the vehicle must be related to the amount of

time it will take that number of members to complete the task. Adding another operator must be justified by a shorter time; such that points gained from shorter

time is greater than points lost due to additional members.

o Metrics: The less people the better. Zero operators is optimal. o Influencing Factors:

! IF1: Operational complexity; Level of autonomy of the system ! IF2: Mechanical complexity

o Strategies: ! ST1: Launcher Launched

! Description: The vehicle uses a launcher for takeoff. ! Benefits: Can launch from almost anywhere. Repeatability. Provides

capability to fly with a greater payload-power ratio than hand

launching, but not as much as taxi launch. ! Drawbacks: Need a launcher. Many moving parts. Hazardous if parts

are fatigued. ! ST2: Taxi Launched

! Description: The vehicle performs a rolling takeoff from a suitable

runway. ! Benefits: Can carry more payload with lower engine power. ! Drawbacks: Need a runway. Need extra sensors such as RTK GPS

and/or magnetometer to support autonomous rolling takeoff. ! ST3: Hand Launched

! Description: The vehicle is launched by hand. ! Benefits: no need for runway or launcher, no landing gear needed,

terrain independent, ! Drawbacks: launch varies every time

! ST4: Runway landing ! Description: The vehicle lands on a flat runway ! Benefits: Allows for heavier airplanes to land ! Drawbacks: requires a big and flat landing area

! ST5: Apparatus Landing (net, wire, chute) ! Description: The vehicle lands using some apparatus such as a flying

into a net, being caught on a wire, or deploying a parachute. ! Benefits: A parachute landing eliminates the need for a runway. Using

a net or being caught on a wire allows the vehicle to land in a shorter distance.

! Drawbacks: Each apparatus will add complexity to the system and

additional points of failure. In a parachute landing will increase the stress on the vehicle as the cute is deployed, a net will cause the

aircraft to stop suddenly and being caught on a ! ST6: Belly Landing

! Description: The vehicle lands on the fuselage instead of using a

landing apparatus. ! Benefits: Mechanically simple. Reduces weight. Faster, simpler landing. ! Drawbacks: Wear and tear on the underside of the fuselage.

! ST7: Autonomous Targeting (addressed in more detail in IT 3) ! Description: The ability of the system to identify targets autonomously. ! Benefits: Decreases the complexity of the system allowing the operator

to simply monitor the system. ! Drawbacks: Difficult to acquire, possible bugs and errors.

Issue Table 2: Bandwidth

o Quality Goals: This issue directly relates to the reliability and the performance goals. o Description: The available bandwidth and overall reliability of the data-link directly

affects the performance of the imaging system since it is geared towards an active

intelligence mission for the UAS competition. These two features of the data-link are dependent on the type of transmitter/receiver and the antennas used to broadcast the

signal. o Metrics: The metric for quality bandwidth is how many kilobits per second at varying

ranges. o Influencing Factors:

! IF3: Amplification ! IF4: Antennas ! IF5: Spectrum ! IF6: Radio Frequency Bandwidth ! IF7: Robustness

o Strategies: ! ST9: Use 802.11a Wifi Connection

! Description: Point to point wifi connection ! Benefits: 5 GHz, 54 megabits per second ! Drawbacks: Not widely supported

! ST10: Use 802.11b Wifi Connection ! Description: Multi point wifi connection. ! Benefits: Well supported, widely available hardware ! Drawbacks: 2.4 GHz, Interference from other devices using the same radio

spectrum. 11 megabits per second. ! ST11: Use 802.11g Wifi Connection

! Description: Multi point wifi connection ! Benefits: 54 megabits per second. Possible MIMO ! Drawbacks: 2.4GHz (interference). Movement may cause data loss.

! ST12: Use 802.11n Wifi Connection ! Description: Multi-in/Multi-out connection. ! Benefits: Multiple channels used for reduced loss of communication. 108

megabits per second. 5 or 2.4 GHz. ! Drawbacks: Not widely supported.

! ST13: Serial Radio Modem Connection ! Description: Serial radio communication ! Benefits: Very long range ! Drawbacks: 900MHz (conflicts with autopilot), 115 Kilobits per second

! ST14: Using Amplifiers ! Description: Use an amplifier to increase the range of the wifi connection. ! Benefits: Vastly increases the range of a wifi connection. ! Drawbacks: Adds weight, draws power, generates heat.

! ST15: Omi-directional Antenna ! Description: With a unity gain antenna power is radiated uniformly in all

directions. The higher the gain the more directed it becomes in a 360

degree arc around the antenna ! Benefits: Antenna does not need to be pointed in a specific direction. ! Drawbacks: Disperses power in 360 degrees

! ST16: Directional Antenna ! Description: an antenna which radiates greater power in one or more

directions allowing for increased performance on transmit and receive,

and reduced interference from unwanted sources. ! Benefits: increased range, widely available

! Drawbacks: concentrated beam, requires ! ST17: Radio Robustness

! Description: The ability for the radio system to continue functionality

despite interference. ! Benefits: Constant communication despite radio interference ! Drawbacks: Overhead

Issue table 3: Targeting o Quality Goals: This issue relates to the goals of quality performance o Description: The capability of identifying targets accurately and efficiently is critical to the

success of the UAS. o Metrics: The metric to justify quality targeting is dependent on how long it takes for the

system to identify a target. o Influencing Factors:

! IF8: Speed at which an operator can use the system to identify and collect

attributes of a target. ! IF9: Color accuracy of the imagery. ! IF10: Resolution of the target imagery. ! IF11: Altitude and airspeed of the vehicle. ! IF12: Positional Accuracy of target.

o Strategies: ! ST18: Use low-res camera (640x480)

! Description: analog video camera with video radio transmitter and receiver. ! Benefits: Simple and inexpensive. ! Drawbacks: Low target resolution.

! ST19: Use a hi-res video camera (1280x1024) ! Description: analog video camera with video radio transmitter and receiver. ! Benefits: High resolution of targets. ! Drawbacks: Expensive. Bandwidth required to transmit video is high.

! ST20: Use a hi-res still camera ! Description: Digital point and shoot camera.

! Benefits: High resolution, mechanically simple, wide selection.

! Drawbacks: Expensive. Bandwidth required to transmit video is high, difficult to interface with the camera

! ST21: Use a Gimbaled Camera.

! Description: Use a camera with pan, tilt and zoom capability. ! Benefits: Ability to direct the movement of the camera to track targets

and/or survey the target area independently of the movement of the

aircraft. ! Drawbacks: Added mechanical complexity. Increased chance of critical

failure. Off the shelf solutions are expensive. ! ST22: Use a fixed-position camera.

! Description: Use a camera without pan, tilt and zoom capability.

! Benefits: Mechanically simple. ! Drawbacks: View of the camera is directly tied to the attitude and position

of the aircraft.

Summary

Using QFD in conjunction with our issue tables, components were chosen to meet as many

requirements as possible. Detailed reasoning for choices made between likely candidates are as follows:

Power Plant

Using the results of the HOQ it was determined that motor type was crucial to the system

and an electric one would be the best solution over a gas or glow fuel engine. An electric system that runs on battery packs would increase the ease of operation, reduce complexity

and the number of parts and reduce vibration, thereby increasing image quality. It was for

this reason that a fully electric system was chosen.

Battery Supply In previous competitions, the primary source of battery power has been Lithium-Polymer

(LiPo). The problem with LiPos is that they can be extremely volatile when charging,

discharging or when slightly damaged. This violates our first quality goal of safety. As an alternative source, DeWalt donated 36V drill battery packs which contain 10-A123s cells

each. By separating the battery packs and removing the A123s the team was able to create

custom 5-cell packs that could be arranged to fit the payload area. The A123s are larger and heavier than LiPos but provide a larger C-rating which allows a greater amperage to be

pulled before damage. The power to weight ratio can therefore be offset with the increased

amps. A123s also hold the advantage in price, at $139.99 for a 10-cell rechargeable drill pack as compared to a single 4-cell Extreme V2 at $104.99.

Programming Environment

In previous years, Team Blackbird tried an approach using Python and other scripting

languages. This year the team decided to use Labview and its Vision Development Module.

Labview is a very powerful programming tool designed by National Instruments. It provides an easy to use graphical interface and programming environment. The program is especially

useful in measurement, automation and data acquisition. It also provides tools for various

types of programming, including event oriented programming, object oriented programming

and scripting in languages similar to C and MathScript. The Vision Assistant provides plenty

of image processing and machine vision capabilities. These capabilities include optical

character recognition, geometric matching, object classification and particle analysis. With the Vision Assistant application it is quick and simple to create, prototype and implement

vision software. Also included in the package is driver software for countless cameras. It

also provides tools like ActiveX and internet communications to interface with most digital cameras on the market.

Imaging

An Axis 207MW camera was ultimately chosen because the fixed position coincided with our

quality goal of simplicity. The digital capabilities of the Axis provide high resolution of

targets which increases the goal of performance. See Issue Table 3: Targeting.

Autopilot There are many different autopilots available that the team could use. The team attempted

to use a Micropilot three years ago, however, it was found that the Micropilot did not

provide the accuracy and ease of use that the team required. Therefore, the team purchased a Piccolo II autopilot and found that it was an ideal solution. The Piccolo II

provides a reliable system capable of maneuvering an aircraft through GPS waypoints with

incredible accuracy using its higher rate GPS. The Piccolo can control up to 10 servos.

Airframe Materials

Our QFD analysis led us in the direction of composites for our airframe construction because of cost per vehicle, endurance, MTBF, aircraft performance and survivability. Balsa was

discounted because of its low tensile strength which means it has very low survivability in the event of a crash. Composites also allow for expedient repairs as compared to balsa. In

our search for composite materials we first researched carbon fiber and fiberglass since they

were used on Team Blackbird's Vampire at last year's competition. Fiberglass was ruled out due to our desire to construct an airframe that will be hand launched and land on its belly

repeatedly on surfaces ranging from grass to asphalt. Carbon fiber has incredible strength

but it has a fatal flaw of severely diminishing Radio Frequency (RF) communications which are vital for an RC plane. Seeking other alternatives, we came across a product called Zylon

which showed great promise. It is incredibly strong, has a high tensile strength, better

elasticity than brittle carbon fiber and is RF transparent. Zylon is an aramid, similar to Kevlar and is the strongest commercially available composite on the market. At similar

prices to a yard of carbon fiber it was decided that our airframe would be comprised of Zylon for its multiple advantages.

IV. Features

Electrical Subsystem:

A123 M1 Cells

• Description o According to the developers of

these batteries, the cells are

"abuse tolerant" and environmentally friendly. The life

of the battery is 10 times that of

a conventional Lithium ion battery. The battery cell is

constructed using laser welds instead of the crimp seals. This provides for low

humidity penetration and stronger heading plates to strengthen the batteries against impact damage.

• Details o Nominal voltage: 3.3V o Core cell weight: 70 grams o Typical fast charge current: 10A to 3.6V [3]

Axis 207MW • Description

o The Axis 207MW provides high bandwidth efficiency by using

MPEG-4 video stream and motion estimation. Digital video is provided in MPEG-4 or MJPG formats.

• Details

o Megapixel resolution up to 1280x1024

o Wireless IEEE802.11g and Ethernet

o Simultaneous Motion JPEG and MPEG-4 [4]

Piccolo II • Description

o The Piccolo II Autopilot is an advanced system

designed by Cloudcap Technologies. It provides

a competent system capable of maneuvering am aircraft through GPS waypoints with incredible

accuracy using its higher rate GPS. The Piccolo can control up to 10 servos for as many control

surfaces that you might require. For safety

concerns the piccolo has a dead man output for when communications times out.

• Details

o Weighs 233 grams

o Operates on 8 - 20 Volts DC

o GPS Update rate of 4Hz

o Utilizes the 900 MHz radio frequency [5]

Hacker A40-10S

• Description o The hacker A40 series was designed to create incredible torque. The motor can

easily be used with in a direct drive prop configuration and eliminate the need for a gear box. The motor series has oversized bearings, curved magnets and high

efficiency stator design. Also there is a cooling fan mounted on the motor to provide appropriate motor cooling in a closed cowl configuration.

• Details o RPM per Volt: 750 o Weighs 265g o Operates on 11 - 18.5 Volts DC [6]

Castle Creations Phoenix 80 • Description

o A high efficiency motor controller designed by Castle Creations to provide reliable power capability for aerial platforms. This motor controller features a battery

eliminator circuit (BEC) and "safe power on." With an audible arming signal and

auto-motor cut-off this controller provides a high level of safety around the motor and prop. The controller is also programmable including adjustable switching

rate, programmable brake and several different timing modes.

• Details

o Operates with no BEC on 25.2 Volts DC

o .001 Ohms resistance

o Reversible directions by simply switching any two wires

o Weighs 60g [7]

Castle Creations RX Battery Eliminator Circuit • Description

o Although the Phoenix-80 comes with an on board BEC the maximum wattage

would be reduced. For this reason Castle Creations makes a separate BEC that

controls the voltage going to the servos. This little device requires no extra batteries, simply plug it in with the motor controller and it will provide power to

the system. Similar to the Phoenix the BEC is programmable to change the

output voltage of the device, which ranges from 4.8 to 9 volts DC. • Details

o Takes 5 - 25.2 Volts o Weighs 11 grams [7]

Airframe Subsystem:

Kadet LT-40

• Description

o Due to time and manpower restrictions for Team Blackbird, a two year plan

allowed us to focus on an adaptable system which could be transplanted into any airframe. It was decided to use a Sig Kadet LT-40 Almost Ready to Fly (ARF)

airframe for its simplicity and cost.

o We hope to complete the design and construction of a Zylon UAV airframe this year but our main goal to meet our software agenda will be fulfilled by the Kadet.

• Details o Clark Y airfoil widely used in general aviation

o 70 inch wingspan

o Planform area of 900 square inches o Length of 56 inches

o Empty weight of 6 pounds

o Generates approximately 45 Newtons of lift o Max airframe and payload weight of 35 Newtons [8]

o Using MotoCalc with the Hacker A40-10S

! Cl = 0.52 ! Cd= 0.063

! Stall Speed 21 mph ! Cruise Speed 32 mph

Zylon

• Description

o For Phase Two of our two-year plan, Team Blackbird is striving to use Zylon for

our airframe structure because of its incredible material characteristics. Zylon has many real world applications ranging from police body armor to parachute tethers

and even parts of the Martian Rovers.

o Zylon does have a few downsides such as its strength degradation when exposed for extended periods of time to ultraviolet light and moisture absorption. Both of

the negative characteristics can be remedied with a simple coat of paint, so it is

ideal for our UAV needs.

o Zylon has as much strength as Carbon Fiber but without the brittleness. This

allows for our airframe to be unbelievably strong and work as a belly-lander where mild crashes will not result in catastrophic fractures or failure as with Balsa

or Carbon Fiber.

o During loading or a crash the fibers of Zylon will stretch into the plastic deformation region of a stress-strain diagram, giving a warning of failure, where

as composites like Carbon Fiber will shatter unannounced or have internal fractures, severely weakening the structure.

o Zylon's long list of benefits has made it an ideal choice for our final construction

which we hope to have completed before this year's competition. • Details

o A 0.6 to 2.0% moisture pick-up rate (common amongst aramids)

o Tensile strength of 5.8 Giga Pascals (GPa) as related to Steel, 2.8 GPa or Balsa, 32.2 Mega Pascals [9]

Ground Station Subsystem:

Blackbird System Software

• Description

o The Blackbird System software was developed by Team Blackbird for the 2009

Student Unmanned Aerial Vehicles competition. It is capable of communicating with an Axis camera and a Piccolo Autopilot simultaneously. This was important

so that the system can put the two different sets of data together to identify the

target attributes accurately. These abilities were separated into three different software packages, the vision package, the Autopilot Communications package

and the Integration package. The system was designed in three parts so that each part could be produced separately and independent of each other and then

the Integration package combine all the necessary data together in on simple

program. • Structure

o The system software has two application executable files. One for acquiring

images and aircraft attitude and another for processing the images and identifying targets.

o The vision software is designed to not only acquire images from an Axis Camera,

but also to process these images and identify possible targets. Using the Labview Vision Development Module, the targeting software is able to easily display

images from the aircraft to the user and allow the user to save the image as a target easily and quickly. Saving the image as a target image also saves the

attitude and location of the aircraft at that time. This allows for post or mid

mission processing of images using a secondary application. The secondary application is designed to allow the user to identify the 8 characteristics of a

target and save the updated information. All images and data are stored in a

binary file generated by Labview using the Target object format designed by the team.

o The Autopilot Communications (AC) software interfaces with the Piccolo II

Autopilot to receive telemetry and location data. The AC is also able to assign new, update existing and delete waypoints to the autopilot. Another ability of the

AC is to show a map of the area that the aircraft is flying in and display the

aircraft in the map as well as all of its waypoints.

V. Testing and Evaluation

Architecture

Evaluation of the architecture was the process of comparing the final system as a whole

with the expectations of the design. The three categories below are the main attributes evaluated.

Antenna interference: The camera was run on 2.4 GHz and the Piccolo on 900 MHz. Multiple

range tests were conducted while both systems were in operation to verify there was not an

increase in latency.

Waterproofing: The system components with the greatest risk of failure due to moisture, such as our voltage regulators and Piccolo, were individually wrapped or sealed. A final

weather-proofing was then completed on the external airframe. Testing in high winds and

severe rain demonstrated no ill effects on the system.

Power plant efficiency: Using the program, MotorCalc, the specifications for the Hacker motor as well as the Kadet LT-40 were entered and a theoretical efficiency was calculated.

MotorCalc gave detailed information on the most synergetic propeller to use as well as the

most efficient cruise speed. Experimental thrust calculations were then done with the actual propellers on the complete aircraft which was attached to a scale to determine pounds of

thrust.

Autopilot

Our House of Quality table was able to identify that the autonomous accuracy of the aircraft is one of the most important issues. Along with its safety features, it is for this reason that

the Piccolo was chosen. The Piccolo uses a u-blox GPS module that has an accuracy of 2.5

m. With this kind of high level GPS the team will easily be able to navigate the GPS coordinates. Having no prior experience with the Piccolo II, we began using the Piccolo

Flight Simulator which demonstrated how to use the autopilot, maximizing efficiency. Once

the Piccolo operators were comfortable with the simulator, autonomous testing began. The aircraft was flown under manual control and the autopilot was enabled so control loops

could be tuned sequentially. The bank loop was tuned first, followed by the airspeed, the altitude, and finally the heading. After the loops were all tuned, a simple rectangular flight

path was set to test tracking and gains. Altitude was then varied along points on this path

and deviations were recorded and troubleshot. Final testing involved the airframe and autopilot being flown under various conditions ranging from calm weather to rain and winds

at 20 kts. gusting up to 25.

Imagery

Our system for identifying targets includes the Axis camera and the software to

autonomously identify targets and store the images. Our imaging software was designed with the functionality of autonomously identifying targets in mind. Therefore, the team used

images from previous years as well as computer generated images of targets. The team ran

a simulation in Google earth that was able to simulate a flight of the aircraft. The simulation consisted of pointing the Axis Camera at the computer screen while Google Earth simulates

the view that the camera would have from the aircraft in flight. The team then placed

simulated targets into Google Earth as new layers. The software was able to successfully identify more than 75% of the targets, both real and computer generated images were in

the pool. The software encountered a few errors with markings on the runways. However,

after tweaking the imaging software it was able to eliminate the markings due to their elongated form.

Flight test data provided sample images simulating expected mission scenarios. Although

high resolution, the camera has limitations on the quality of the images in flight, therefore the light sensitivity and shutter speed must be calibrated manually. The image above shows

wash out due to over exposure of the lettering on a pale green target and blur of the blue

target. This is caused by the auto adjustments being made as the camera transitions with respect to its position with the horizon. The camera, once manipulated, produces targets

similar to the white ‘Z’ on the red target. Once the images were acquired and the

appropriate telemetry data was applied, they were saved in a format to make them reusable for testing the imaging software. Images in this format could be run through filters in the NI

Vision Assistant to test the quality of the programming. By recording the location of the

targets, ground plane transformation equations can be tested.

Component Placement The placement of components in the aircraft is an important aspect of designing the aircraft.

It is important to keep in mind that the aircraft has a maximum weight limit and therefore

each component must be weighed and placed securely in the aircraft so as not to disturb the balance of the craft. The team decided to put the batteries in the front of the plane

while the Piccolo and the camera as close to the center of the wing as possible to conserve

the balance. Another important aspect to consider when placing components is where the antennas go. The system has a total of two RF antennas and one GPS antenna. The antenna

for the camera on the 2.4 frequency serves best if it is pointed towards the ground so that

our ground station communications won't be interrupted or disturbed by anything inside the aircraft. The team had to ensure that the antennas would not interfere with each other or be

interfered with while the plane was flying. The team did countless range tests and found

that the while both systems, camera and autopilot, are running there was no problem communicating to either system.

VI. Safety

Safety is Team Blackbird's primary quality goal and has been at the zenith of our systems

engineering process. Safety for each of the subsystems is as follows:

Autopilot

The Piccolo II has a built-in manual override which allows for an experienced RC pilot to take command in the event of an unforeseen aerial malfunction. In the event of

communication loss with the receiver in which the pilot is unable to take command, the

autopilot asserts flight termination by means of immediate spiral descent.

Power Plant

Along with advantages in complexity and ease of use, an electric motor was chosen for its noncombustible nature as opposed to a gas or glow fuel engine.

Battery Supply Team Blackbird installed A123s instead of LiPo batteries for cost and safety considerations.

In the event of a crash or during charging and discharging, LiPos pose an immediate threat to those in range of a possible explosion. It was for this primary reason that LiPos were

discarded as a possible battery source.

Materials

For future airframe construction Zylon has been chosen for its amazing properties, of which

failure inspection is one of the greatest. Zylon will stretch out giving a warning of impending failure and its single ply construction allows for visible inspection of all surfaces. Other

composites and balsa have much smaller plastic deformation regions or none at all which

might allow a fracture to go unnoticed, causing mid-air structural failure on subsequent flights.

Checklists

Team Blackbird has constructed both preflight and post-flight checklists which allow for

inspection of the airframe and subsystems ensuring they are in working order before current and future operations.

VII. Acknowledgements

Dr. Towhidnejad, Dr. Reinhotlz, Soller Composites, Jayson Clifford, DeWalt

VIII. References

[1] Cockburn, A (2005). Crystal clear: A human-powered methodology for small teams.

Addison-

Wesley.

[2] Akao, Yoji. "Development History of Quality Function Deployment". The Customer Driven

Approach to Quality Planning and Deployment. Minato, Tokyo 107 Japan: Asian Productivity Organization. pp. 339. ISBN 92-833-1121-3.

[3] A123 Systems Website. www.a123systems.com.

[4] Axis Communications Website. www.axis.com

[5] Cloudcap Technologies. http://www.cloudcaptech.com/

[6] Hacker Brushless Motors. http://www.hackerbrushless.com/

[7] Castle Creations. http://www.castlecreations.com/

[8] SIG Manufacturing Co. Website. www.sigmfg.com/

[9] Toyobo’s website. http://www.toyobo.co.jp/e/seihin/kc/pbo/menu/fra_menu_en.htm