Inspection Robot

RAFIK HARIRI UNIVERSITY

INSPECTION ROBOT

Done by

SALAHIDDIN EL-JAMMAL

AHMAD TARRAF

AHMAD RHIMY

Submitted to

DR.NIZAR AWAR

This senior project is submitted in a partial fulfillment of BS degree of Mechatronics

Engineering major of the college of Engineering

at Rafic Hariri University

MECHREF-LEBANON

April 2013

Copyright © 2013. All Rights Reserved

Salahiddin El-Jammal(2010-0396)

Ahmad Tarraf(2010-6009)

Ahmad Rhimy(2010-0334)

ii

ABSTRACT

This book describes a Remotely controlled Intelligent Tracked Inspection Vehicle

(RITIV) that relies on Mechatronics engineering to provide a more advanced solution for

inspecting in many dangerous arenas including dark or small caves, deep mines, forests,

snow areas, mine fields, battle fields, places poisoned with gases and radioactive materials,

and other dangerous or unreachable places.

The robot consists of three major parts: first one is the main body containing tracks

to overcome various obstacles. Second part is the camera and sensors for detecting any

surrounding that could affect the mechanism of the robot. Finally, a robotic arm is

implemented on the chassis of the robot which have the ability to carry any object from the

ground and safely transport it to the desired destination.

This book presents the whole process of development including electric schematics,

programs and codes, and a full description of the series of hardware used in this inspection

robot.

iii

ACKNOWLEDGEMENT

For all the knowledge he helped us to gain and for all the help he provided us, we

dedicate this book to our advisor Dr. Nizar Awar. We would also like to thank all

instructors at RHU who lightened our way towards exploring the future through our

education. As Charles William Eliot said, “Books are the quietest and most constant of

friends; they are the most accessible and wisest of counselors, and the most patient of

teachers.”

Finally, we dedicate this book and all our success to our beloved parents who were

the major support for us and are the ones who raised us to become better individuals in the

society.

iv

TABLE OF CONTENTS

ABSTRACT .....................................................................................................................ii

ACKNOWLEDGMENTS ...................................................................................... iii

TABLE OF CONTENTS ......................................................................................... iv

LIST OF FIGURES .................................................................................................... vi

LIST OF TABLES......................................................................................................vii

Chapter Page

1. INTRODUCTION ................................................................................................... 1

1.1.Background Information ....................................................................................... 1

1.2. Literature survey .................................................................................................. 2

2. PROJECT OVERVIEW ...................................................................................... 3

2.1. Statement of the problem ..................................................................................... 3

2.2. Description of the system ................................................................................... 4

2.2.1. Advantages of the system ..................................................................... 4

3. PROJECT HARDWARE ................................................................................... 6

3.1. Remote Control Tracked Vehicle ........................................................................ 6

3.2. Robotic Arm ........................................................................................................ 7

3.3. Wireless Camera ................................................................................................. 8

v

3.4. PIC Microcontroller ............................................................................................ 9

3.5. Dynamics of the system .................................................................................... 10

3.5.1. Characteristics of the drag motors ..................................................... 10

3.5.2. Dynamic Analysis of the Robotic Arm .............................................. 10

4. SUBSYSTEM BEHAVIOR ............................................................................ 13

4.1. Receiver Circuit ................................................................................................. 13

4.1.1. Hardware ............................................................................................. 13

4.1.2. Functionality ....................................................................................... 14

4.2. Transmitter circuit.............................................................................................. 14

4.2.1. Hardware ............................................................................................. 14

4.2.2. Functionality ....................................................................................... 15

4.3. RasBerryPi ......................................................................................................... 16

5. PROGRAM CODES ........................................................................................... 20

5.1. Receiver Microcontroller Program ................................................................... 20

5.2. Transmitter Microcontroller Program ............................................................... 27

5.3. Synapse receiver/ Transmitter Program ............................................................ 29

6. PROBLEMS AND SOLUTIONS ................................................................ 30

7. COSTS AND EXPENSES ............................................................................... 32

8. CONCLUSION AND SKILLS LEARNED ........................................... 33

9. REFERENCES ........................................................................................................ 34

vi

LIST OF FIGURES

Figure Page

1. Main Body of the Inspection Robot ................................................................................... 6

2. Robotic Arm ....................................................................................................................... 7

3. Camera (Raspberry Pi controlled) ...................................................................................... 8

4. PIC 16F877A ..................................................................................................................... 9

5. Modeling of the Arm ....................................................................................................... 10

6. Receiver Circuit Diagram ................................................................................................ 13

7. Transmitter Circuit Diagram ............................................................................................ 15

vii

LIST OF TABLES

Table Page

1. Statistical data of mines injuries and death ........................................................................ 3

2. Costs ................................................................................................................................. 33

1

CHAPTER 1

INTRODUCTION

1.1 Background Information

As the field of inspection is developing day after day, the necessity is making us

more in need to overcome all obstacles and to interact with the surroundings in order to

achieve our goals in inspection.

Going back in history, the act of inspection started in the United States on 1906, by

forming a local agency to inspect food and sold meat and groceries. It was called “Federal

Meat Inspection Act” FMIA. Through time, that agency developed to become responsible

for inspecting drugs, cosmetics and also food.

Until the 21th century, and when the world entered the wave of wars and military

action, inspection was not relying on food and drugs in one side, but it overcame that to be

responsible for scientific and military uses. So here came the great quote “necessity is the

mother of invention”, when technology enabled us to search –using the available sources-

to manufacture advanced modes of inspection robots that could face those obstacles and aid

in achieving some challenging zones such as mine fields, battle fields, or places poisoned

with gases and radioactive materials.

However, these kinds of robots with their cameras and advanced robotic arms will

be a very creative and helpful source in order to switch off a bomb or to activate a security

system and also helping us as Mechatronics engineers to follow the advanced plans in

control and manufacturing.

2

1.2 Literature Survey

In the scope of inspection, danger is the major threat for human investigators. Many

inspectors have lost their lives or parts of their bodies during inspection journeys. There

have been many attempts to solve this problem by different approaches; one of the most

promising solutions is building inspection robots.

Inspection robots are remotely controlled robots that can take the mission of human

inspectors in dangerous or unreachable regions. Many attempts of building inspection

robots have been made but none of them have met the appropriate specifications with the

acceptable cost.

Although the science of robotics came in the 20th century, the robotics field in 20th

and 21th centuries has advanced and developed to associate the remote controlled robots

and machines that are capable of receiving and sending data and also correct some mistakes

done by human beings.

As our survey is including what important sites and references had many opinions

about robotics and inspection, some IEEE members proposed several ideas to enrich this

new field in the century. One of these ideas was Transmission line inspection robot and

deicing robot which was based on manufacturing an inspection robot that is equipped with

inspection sensors/instruments, deicing manipulator and communication device that could

perform on-line detection/inspection of mechanical/electrical failures.

However, the idea of designing and manufacturing inspection robots is spreading

worldwide, not only in NASA and military agencies, but also it has spread to include

universities and civilian research institutes.

3

CHAPTER 2

PROJECT OVERVIEW

2.1 Statement of the Problem

According to statistics, it can be inferred that minefields’ are wide all over the

Lebanese lands due to the wars that the country faced in the past 30 years.

Due to a survey done by the United Nations Mine Action Service from the years 1990

till 1997 about the death and injury cases caused by minefields in Lebanon. The following

table is obtained showing the various numbers of civilians and army members that were

either killed or injured by the act of mines. (minestatisticsPlaceholder1)

Table1: Statistical data of mines injuries and death

VICTIMS

CIVILIANS MILITARY

Year Killed Injured Killed Injured

1990 12 15 - 8

1991 36 78 5 34

1992 11 41 3 14

1993 23 33 - 12

1994 23 32 2 10

1995 16 15 1 5

1996 6 18 1 1

1997 7 17 - 1

TOTAL 134 294 12 85

4

Nowadays, these numbers are in a slight decrease because we are still having some

uninhabited lands in south Lebanon. So to overcome this conflict, inspection robots would

be manufactured to help finding these mines and save many lives. The idea of this project

is to create a smart robot capable of inspecting and finding such mines.

2.2 Description of the System

The inspection robot mainly consists of a fixed plastic body that is dragged by two

rubber tracks which enable it to walk through hard and rough surfaces such as minefields or

radioactive mediums, with its camera and the robotic arm it is able to receive and send data

to the user and carry any object and as we said, move it safely to a desired place.

2.2.1 Advantages of the System

Although many robots have been used for so long, this robot is capable of

performing some hard tasks that a human being is unable to do so. First, its plastic

body which is dragged by the rubber tracks is light so the movement would be

flexible. Also the efficiency to move from a frictional to a frictionless medium is

high. Second, the web controlled camera placed in the front of the body is

specialized by the long range that could reach 50 meters on Wi-Fi, (it can reach

more if a GSM module is implemented).

The Camera is controlled by WIFI (wireless network) and the range can

increase as the signal’s strength increase. Concerning the range largely depends on

the type of obstacles it faces (walls, rocks, trees…)

Third, the inspection robot is controlled by synapse wireless transceiver

modules which is a new technology wireless transceiver module. The one we are

using is RF200PD1 (reference). It may reach to 3 miles range. The normal bit rate

of this module is 2Mbps, (it reduces as the distance between the modules increase).

Fourth, the robotic arm is has a very simple and intelligent design consisting

of some metallic stands, three DC motors, and two stepper motors and plastic

5

tweezers that is also light in weight and doesn’t affect the motion of the arm. The

arm is capable of holding some sensitive objects on one hand, and on the other

hand, it can be replaced by a metallic cutter that could help deactivating a bomb or

cut a metallic wire.

6

CHAPTER 3

PROJECT HARDWARE

3.1 Remote Control Tracked Vehicle

The remotely controlled vehicle consists of a plastic body that has tracks on both

sides, these rubber tracks are capable of moving on frictional and frictionless surfaces

without any deviation away from the path using two DC motors. Note that these tracks are

connected by a mean of a metallic wire that allows the robot to take climbing position that

could enable it to climb on stares or rocks. And the remote controlled camera is placed on

the body of the robot. Finally, the whole system is powered by a 12 volts DC rechargeable

power supply that is placed in the back of the vehicle.

Figure.1: Main Body of the Inspection Robot.

7

3.2 Robotic Arm

The robotic arm consists of one DC motor and four 5-volts Stepper motors and

plastic tweezers that can carry any object and as we said, transmit it safely to a desired

destination. Add to that this arm is formed by 4 main assembly parts: the rotor, the crane,

the wrist, and the clamps. All these main parts are controlled by the mean of a PIC

microcontroller.

Figure.2: Robotic Arm

8

3.3 Wireless Camera

The camera used in the inspection robot works by a web server which is connected

to the same wireless network that is –in our case- an ANDROID HOTSPOT. The camera is

directly connected to the RasBerryPi, receiving the image of the surroundings and sending

it back to us without any disturbance or noise. In addition, the camera is controlled by the

RasBerryPi server for better image processing.

Figure.3: Camera (Raspberry Pi controlled)

9

3.4 PIC Microcontroller

PIC or Peripheral Interface Microcontroller is made by microchip technology based

on Harvard architecture. PICs are popular due to their availability, low cost, and serial

programming.

PIC 16F877A is one of the best from its family. It comes with a 40 pin DIP pin out

with many peripherals.

Figure.4: PIC 16F877A

10

MikroC was the programming language used to program the PIC and programmed via

a PIC programmer.

3.5 Dynamics of the System

3.5.1 Characteristics of drag motors

The motors used for dragging the robot are 12V 1A motors. They can drag

the robot with the arm by 4m/s (it may reach 2m/s if 1.5Kg weight is loaded on the

vehicle)

3.5.2 Dynamic Analysis of Robotic Arm

Figure.5: Modeling of the arm

The figure shows the layout of the Robotic Arm. At this position we will

have maximum stresses (maximum distance) the purpose from the following is to

find the maximum forces and moments (thereby the stresses) in the Arm. then we

will make an assumption for the base, and see if the base will be subjected to any

yielding or failure.

11

Maximum compressive force

F =m1*g+m2*g

=0.200*9.81+0.15*9.81

=3.4 N

Maximum moment

µ = - m1*g*d1+m2*g*d2

= -0.200*9.81*5.5*0.001+0.15*9.81*24*0.01

= 0.0137 N.m

Since exact data are not given, we will assume a safety factor of 4.

We are dealing with an annealed stainless steel (303), Sy= 241 and MpaSut=

601 Mpa. So our designing yield stress and our designed ultimate stress are Sy’ =

60.25, and Sut’ = 150.25. Also we have ƹf =1.16>0.05, so we are dealing with a

ductile material.

After we have our strengths, it’s time to calculate our stresses; this situation

is a plane stress. Moreover, for the stress in the y-axis:

The cross-section area of the base axis is 3.5 mm2.

Γ3 =Γy = f/A

= F/π*r^2

= 3.4/(38*10^-6)

= -94444.4pa (in compression)

For the stress in the x-axis:

Γ1 =Γx=Mc/I

= Mc*64/π*d4

=64M/2*π *d3

= 32(0.0137)/π*(7*10-3)3

=407049.07 pa

12

Being most conservative, we will assume maximum shear stress.

Γ1-Γ3=Sy

94444.4 + 407049.07=50.19 Kpa<60Mpa

So neither yielding, nor failure will occur.

To emphasis on our problem more, we will calculate the maximum mass that can be

placed before yielding.

F =m1*g+m2*g

=0.200*9.81+m*9.81

=1.962 + 9.81m

µ = - m1*g*d1+m2*g*d2

= -0.200*9.81*5.5*0.001+m*9.81*24*0.01

=-0.0010791+0.23544m

Γ1-Γ3 =Sy

32*µ/π*d3-F/A = Sy

32*(-0.0010791+0.23544m)/π*(7*10-3)3+1962+9.81m/ (38*10-6) = 60*106

Solving for m:

m=7.53 Kg

So the maximum mass that can be supported by the arm before yielding(according

to the previous assumption is) m=7.53 Kg

4.1 Receiver Circuit

4.1.1 Hardware

• PIC 16F87

• Voltage Re

• Oscillator 2

• Reset Butto

• On/Off Sw

• Capacitors

• Resistors (

• Synapse (R

• 12 volts DC

• H-Bridge L

13

CHAPTER 4

SUBSYSTEMS BEHAVIOUR

16F877A

age Regulator 7805

llator 20 MHz

t Button

ff Switch

citors (100 NF, 22 PF)

stors (10 KΩ)

pse (RF engine)

olts DC power supply

ridge L298N

Figure.6: Receiver Circuit Diagram

14

4.1.2 Functionality

• The clamp stepper motors’ control lines are connected to each other

reversely so that they rotate in opposite directions. That is; pin1 of motor

1 is connected to pin 4 of motor 2, pin2 to pin 3, pin3 to pin 2, and pin 4

to pin 1.

• The stepper motors are connected to driver circuited implemented on the

arm itself.

• The Drag, rotor, and crane motors are interfaced to the PIC by the means

of an H-Bridge.

• The Crane Down control pin uses PWM control for smooth descending

of the arm, while the Crane Down pin is directly connected to the H-

Bridge

4.2 Transmitter Circuit

4.2.1 Hardware

• PIC 16F877A

• Voltage Regulator 7805

• Play station controller

• Oscillator 20 MHz

• Reset Button

• On/Off Switch

• Capacitors (100 NF, 22 PF)

• Resistors (10 KΩ, 1 KΩ)

• Synapse (RF engine)

• 9 volts DC power supply

4.2.2 Functional

• The inp

and to

logic 1

• The r

microc

• The pu

control

15

Figure.7: Transmitter Circuit Diagram

ionality

he input to each pin is connected to the ground th

nd to a push button which, when switched on, co

ogic 1 (5V).

he resistors are implemented on the circ

icrocontroller.

he push buttons are implemented on a PS2 Cont

ontrol of the robot

und through a 10K resistor

on, connects the pin to the

circuit with the PIC

Controller for convenient

16

4.3 Raspberry Pi

These steps will explain how to set up the raspberry pi as a webcam server.

• The first step is to get the OS of the raspberry pi from its website.

• Then run an application called “Win32DiskImager”. The application will copy

the download image of the OS into the SD card (SD card> 2GB).

• After this connect the pi to the TV (either through the HDMI port, or through

the standard video transmitter). Once it boots you can change the password.

Then select enable SSH in a configuration window that will show up once the pi

is logged in (standard password are provided at the website).Then, the raspberry

pi will reboot.

• Now, we need to update and upgrade different programs on the raspberry pi

using the command apt-get. But the problem is that here in Lebanon we have

different mirrors.

• To change the mirrors, use the SSH using a program called putty, and a Ethernet

cable connected between the pi and the PC). But to use SSH, we need to know

the IP address of the pi. So, as the pi is connected to the TV, type "ifconfig" and

copy the IP address, now we don't need the TV any more.

To change the mirrors:

• Type: sudo nano /etc/apt/sources.list

• A new window will appear, Now change the mirror.

• Delete the old one. Paste this: deb http://archive.raspbian.org/raspbian wheezy

main

17

• deb-src http://archive.raspbian.org/raspbian wheezy main or one of the closets

to your country (in our case Lebanon) from:

• http://www.raspbian.org/RaspbianMirrors

• (http://mirror.nus.edu.sg/raspbian/raspbian)

• (The best for me was: deb http://distributionus.hexxeh.net/

raspbian/archive/raspbian/ wheezy main contrib. non-free rpi)

• Then ctrl+x to exit, y to save, and enter.

• After that type sudo apt-get update (this will load the new links for the apps)

• And then sudo apt-get upgrade to upgrade the system (this will take some time).

• Now the pi is ready. If you want to lunch into a desktop environment, connect it

to the TV and type startx. This will launch the desktop environment.

• Now we can use the pi for different purposes.

We want to use the pi as a webcam server, where a wifi adapter will connect it to

the internet, and a camera will send data through the pi to the internet via an application

called “motion”. Therefore, we will first configure the wireless internet. To do so, we will

need a compatible wifi adapter.

After we plug in the adapter and camera, we type lsusb. This will show us the

connected deices. If the device is recognized,we will see a number and a name on a new

line, if not, it will show an empty buss with a specific number.

After we made sure that the device is compatible, we will start the configuration

(Configuring your Raspberry Pi for WPA_WPA2 in less than 5 minutes – YouTube this

video would explain a lot)

18

After configuring the wifi and connecting the wifi adapter, we are now ready to

configure the webcam via a web server.

Install the application called motion. To do so, type sudo apt-get install motion.

Proceed with typing 'y'. This will run a command that will download motion via a

wireless.(id wireless is not connected, make sure to connect the Ethernet to the pi ,to check

it write ifconfig, and see if you have a value. Or make sure that you that the wifi connected

at the raspberry pi has internet access, in case of using the adapter).

To make sure that the webcam is working, type lsusb. You should be able to see the

device number and some id besides the code.

Make sure that the cam is Linux supported, if it's not, than try to use a webcam with

an open driver as we did. now after that, we will modify the cam properties according to

our preference. To do so, first we need to be a root user. Type sudo i. after that we can now

configure the motion file. Several things must be changed. First type sudo nano

/etc/motion/motion.conf

This will lead us to the configuration file. And we use nano to edit it. in there we

need to change the directory of the motion file to home. Also we need to set the port

number. Turn demon on and change the resolution to be compatible with the video device.

Now write sudo service motion restart. This will restart motion and we will be able

to open it in the port. Type ifconfig and copy the IP address.

Now, go to a browser (we recommend Firefox) .type in the IP address with ":" and

the port number and you will be able to stream the video at this address (if the computer is

connected to the same wifi.)

Something to add is that we can control the motors from the web by installing

similar apps. With this we will be able to control even the Robot from the web.

19

One advantage of this is: if we us a wireless adapter like one that uses a SIM card

and a 3g network, we will be able to control the robot from any location. but since it is not

available, and it would increase the cost of our project a lot, we will use the synapse, which

has also a great range (3 miles) and is great for control application.

20

CHAPTER 5

PROGRAM CODES

5.1 Receiver Microcontroller Program

char uart_rd; // Char variable to save the received

data

int i; // Counter used in the stepper motor

codes

int current_duty; //Integer variable to for the duty cycle

void rmf() // Right motor front

PORTA.B0=1;

PORTA.B1=0;

void rmb() // Right motor back

PORTA.B0=0;

PORTA.B1=1;

void rms() // Right motor stop

PORTA.B0=0;

PORTA.B1=0;

21

void lmf() // Left motor front

PORTA.B2=1;

PORTA.B3=0;

void lmb() // Left motor back

PORTA.B2=0;

PORTA.B3=1;

void lms() // Left motor stop

PORTA.B2=0;

PORTA.B3=0;

void ClampClose(int k) // Clamp Close

for (i=0;i<k;++i)

PORTB.B0=1;PORTB.B1=1;PORTB.B2=0;PORTB.B3=0;

DELAY_MS(3);


DELAY_MS(3);


DELAY_MS(3);


22

if (i<k-1) DELAY_MS(3);


void ClampRelease(int k) //Clamp Release

for (i=0;i<k;++i)


DELAY_MS(3);


DELAY_MS(3);


DELAY_MS(3);


if (i<k-1) DELAY_MS(3);


void RotorR() // Rotor right

PORTB.B4=1;

PORTB.B5=0;

23

void RotorL() //Rotor left

PORTB.B4=0;

PORTB.B5=1;

void RotorS() //Rotor stop

PORTB.B4=0;

PORTB.B5=0;

void CraneU() // Crane up

PORTD.B0=1;

PWM1_Stop();

void CraneD() // Crane down

PWM1_Start();

PWM1_Set_Duty(current_duty);

if (current_duty<255)

++current_duty;

DELAY_MS(10);

24

void CraneS() // Crane stop

PORTD.B0=0;

current_duty = 0X43;

PWM1_Stop();

void WristU() // Wrist up

PORTB.B6=1;

PORTB.B7=0;

void WristD() // Wrist down

PORTB.B6=0;

PORTB.B7=1;

void WristS() // Wrist stop

PORTB.B6=0;

PORTB.B7=0;

25

void main()

ADCON1=7;

TRISA=0X00;

TRISB=0X00;

TRISD=0X00;

TRISE=0X00;

PORTA=0X00;

PORTB=0X00;

PORTD=0X00;

PORTE=0X00;

UART1_Init(9600);

Delay_ms(100);

current_duty = 0X43;

while (1)

if (UART1_Data_Ready())

uart_rd = UART1_Read();

PORTE.B0=1;

DELAY_MS(1);

PORTE.B0=0;

DELAY_MS(1);

26

switch (uart_rd)

case 'A':rmf (); break;

case 'B':rmb (); break;

case 'C':rms (); break;

case 'X':lmf (); break;

case 'Y':lmb (); break;

case 'Z':lms (); break;

case 'G':ClampClose(20); break;

case 'H':ClampRelease (20); break;

case 'I':WristU (); break;

case 'J':WristD (); break;

case 'K':WristS (); break;

case 'L':CraneU (); break;

case 'M':CraneD (); break;

case 'N':CraneS (); break;

case 'O':RotorR (); break;

case 'W':RotorL (); break;

case 'Q':RotorS (); break;

default: break;

27

5.2 Transmitter Microcontroller Program

char uart_rd;

void main()

TRISB=0XFF;

TRISD=0XFF;

PORTD=0X00;

UART1_Init(9600);

Delay_ms(100);

while (1)

if (PORTB.B0 == 1 && PORTB.B1 == 0)

uart1_write('A');

else if (PORTB.B0 == 0 && PORTB.B1 == 1)

uart1_write('B');

else

uart1_write('C');


28

uart1_write('X');


uart1_write('Y');

else

uart1_write('Z');


uart1_write('G');


uart1_write('H');


uart1_write('I');


uart1_write('J');

else

uart1_write('k');

if (PORTD.B4 == 1 && PORTD.B5 == 0)

uart1_write('L');

else if (PORTD.B4 == 0 && PORTD.B5 == 1)

uart1_write('M');

else

uart1_write('N');

29

if (PORTD.B6 == 1 && PORTD.B7 == 0)

uart1_write('O');

else if (PORTC.B6 == 0 && PORTC.B7 == 1)

uart1_write('W');

else

uart1_write('Q');

5.3 Synapse receiver/transmitter Program

otherNodeAddr = "\x04\x3E\xC3" # <= put the address of the PCs USB-attached node here @setHook(HOOK_STARTUP)

Def startupEvent (): InitUart (1, 9600) # <= put your desired baud rate here! FlowControl (1, False) # <= set flow control to True or False as needed CrossConnect (DS_UART1, DS_TRANSPARENT) UcastSerial (otherNodeAddr)

30

CHAPTER 6

PROBLEMS AND SOLUTIONS

Many problems have faced us during the design and implementation of the

inspection robot:

• The video transmission was the most important and challenging problem in the

project. Since video transmission needs a high speed processor, relatively large

RAM size, and a much larger bit rate for wireless transmission, we had no

solution other than implementing a USB webcam on the raspberry pi which has

these specifications.

• The size of the robot was one of the greatest challenges during the design of our

project. Because the purpose of the robot is inspection, it should have a small

size in order to not be easily noticed and for easier movement.

• Power was another major problem in the design of the robot. Least power

consumption motors, drives, and electronics parts were used to maintain power.

• Descending the crane (the longest part of the arm) was a big problem since the

power needed to lift the crane is much more than the power needed to descend

it. We use PWM to manage (reduce) the power given to the motor of the crane

while falling down.

• Stabilizing the crane was another major problem during the implementation of

the robot. First, stepper motors were used to for the rotor and the wrist. But the

problem with the stepper motor is that it cannot hold the initial load loaded to it

when it is in the standby mode. Geared DC motors were used instead to fix this

problem.

• A problem which we have been struggling with from the beginning of the

semester is the wireless control. The available cheap RF modules had 2 major

problems. One was with the repeatability of the correct data transmitted or

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received, and the second was in the range of transmission. Synapse RF engines

were used to overcome this problem.

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CHAPTER 7

COSTS AND EXPENSES

Item Price Number Subtotal

PIC16F877A 4$ 2 8$

Track and motors 20$ 1 20$

Geared DC motors 10$ 3 30$

Stepper motors 5$ 2 10$

Stepper driver circuit 2.5$ 2 5$

H-bridge 3$ 3 9$

Synapse RF Engine 35$ 2 70$

Synapse programmer 30$ 1 30$

Raspberry pi 60$ 1 60$

USB Camera 15$ 1 15$

Wireless adapter 10$ 1 10$

Voltage regulator 0.5$ 3 1.5$

Oscillators (crystals) 1$ 2 2$

12V Power supply 15$ 1 15$

9V power supply 1.5$ 1 1.5$

PS2 joystick 10$ 1 10$

Others* 15$ 1 15$

Total 302$

Table 2: costs

*Others: include small electronics parts, glue, metallic bars, connectors, and others…

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CHAPTER 8

CONCLUSION AND SKILLS LEARNED

Building this robot had a significant effect in improving the technical engineering

skills which completed the theoretical knowledge about the field of inspection, and the

most valuable achievement was the team work and cooperating to complete all the duties

and to make sure that the parts are well assembled are properly functioning without any

problems.

Mechatronics is a major that presents innovative concepts in designing and creating

products that are enhanced and intelligent artifacts. Our main point of our project is that

starting from a small idea to protect civilians and military members ended with a well

designed handmade inspection robot that would overcome many hard conditions and

successfully fulfill all desired goals in the field of inspection.

This BS project has helped the members of the group to understand the integration

between subsystems and dealing with Microcontroller-programming problems and studying

of the mechanism of stepper and DC motors and combining their mechanisms in order to

accomplish the studied analyses with stresses and factors of safety and degrees of freedom.

After all, engineering is the technique and the skill that enabled us to improve our

way of thinking and moving from a scratching theoretical point of view to a designed and

assembled prototype that is ready to accomplish all duties. In college I read what they told

me and was much the better for it." John Updike, Esquire, 2008

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REFERENCES

[1] (n.d.). Retrieved from http://www.undp.org.lb/programme/pro-

poor/crisisprevention/landmines/docs/report.pdf

[2] (n.d.). Retrieved from http://www.sierracollegemechatronics.com/quote/quotes.htm

[3] (n.d.). Retrieved from http://www.asme.org/kb/news---articles/articles/robotics/robots-

inspect-lines-while-hanging-from-above

[4] (n.d.). Retrieved from

http://ieeexplore.ieee.org/xpl/articleDetails.jsp?reload=true&arnumber=1491726

[5] (n.d.). Retrieved from http://publications.asl.ethz.ch/files/buehringer09cablecrawler.pdf

[6] cnki.com.cn. (2006). Retrieved from http://en.cnki.com.cn/Article_en/CJFDTOTAL-

WSDD201201018.htm

[7] solarbotics. (n.d.). Retrieved from https://solarbotics.com/download.php?file=1646

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