GOVERNMENT POLYTECHNIC PUNE AN AUTONOMOUS INSTITUE OF GOVT. OF MAHARASHTRA PROJECT REPORT ON AUTOMATED TRANSPORT SYSTEM USING COLLISION AVOIDER, LINE FOLLOWER AND PATH MONITORING
“CYBORG” GUIDED BY PROF. MR C.R.JOSHI PRESENTED BY Mast. SANKET BORHADE (0603026) Mast. PRATIK JAIN (0603030) Mast. GANESH PATIL (0603039) Mast. SAGAR PATIL (0603040) Mast. PRASHANT SUSHIR (0603048) Mast. LALIT SUTAR (0603049) 1
GOVERNMENT POLYTECHNIC PUNE AN AUTONOMOUS INSTITUE OF GOVT. OF MAHARASHTRA
CERTIFICATE This is to certify that, Mast. SANKET BORHADE (0603026) Mast. PRATIK JAIN (0603030) Mast. GANESH PATIL (0603039) Mast. SAGAR PATIL (0603040) Mast. PRASHANT SUSHIR (0603048) Mast. LALIT SUTAR (0603049) Students of third year Electronics and telecommunication have carried out the project work on “AUTOMATED TRANSPORT SYSTEM USING COLLISION AVOIDER,LINE FOLLOWER AND PATH MONITORING”(CYBORG) satisfactorily under my supervision and submitted the response for the partial fulfillment of diploma course in electronics and telecommunication during the ACADEMIC YEAR 2008-2009. Date of issue:-
PROF C.R.JOSHI
PROF C.R.JOSHI
(Project guide)
(H.O.D)
PROF MR.D.N.SHINGADE (Principal)
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ACKNOWLEDGEMENT: As students of the final year of DIPLOMA (Electronics & Telecommunication), we are required to undertake a project. Our project is titled “AUTOMATED TRANSPORT SYSTEM USING COLLISION AVOIDER, LINE FOLLOWER AND PATH MONITORING” (CYBORG). Herewith is encapsulated a report of the same. In our attempt, we have come to realize that automation (robotics) is a field which is not just an isolated field on its own. It is the fusion of a number of concepts from the entire major Engineering fields. Hence our journey had a number of guides, each one from a different field. In submitting this report, we, would like to take the Opportunity to thank all these people, without whose help our modest endeavour would never have seen the light of the day. First of all we would like to thank God Almighty for giving us the strength and confidence in pursuing the ambitions. We also take immense pleasure in thanking Prof. Mr. C.R. Joshi (HOD, E&TC Dept.) who is our guide and the major helper and guidance giver. Mr.Bhagesh Lokhande and Mr. Kundan Lokhande (system automation, Wagholi) who helped us with our technical difficulties. Technologically advancement will enable us to get the environment we desire. In this era of modernization & sophistication our endeavour to achieve complete and perfect knowledge in the field we choose will be successful only with the help of guidance, direction, stimulation & encouragement by all our esteemed professors. We would also like to acknowledge the enthusiastic support that was given to us by the faculty of E&TC Dept., who not only gave us moral support but were actively interested in our project through all its ups and downs. Last but not the least; we would like to acknowledge the unquestioning and untiring support from our families.
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CONTENTS FOREWORD
5
INTRODUCTION
6
ABSTRACT
7
NECESSITY OF SYSTEM
8
MARKET SURVEY
9
BASIC CONCEPT
10
BLOCK DIAGRAM
11
EXPLAINATION
12
CALIBRATION
18
ALGORITHM
19
FLOWCHART
21
PROGRAM
23
PROCEDURE
28
PCB DESIGNING
29
CIRCUIT LAYOUT
31
COMPONENT LIST
32
TESTING
33
COMPONENT DESCRIPTION
36
ADVANTAGES
43
DISADVANTAGES
44
OBSERVATION & TROUBLE-SHOOTING
45
TOTAL COST
47
LEARNING EXPERIENCE
49
CONCLUSION
51
DATASHEETS
53
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FOREWORD: The word robot was coined by the Czech writer Kapek in his play ‘Rossum's Universal Robots’. Since then countless devices have been created and have been associated with the word ‘Robot’. The works of Isaac Asimov have laid the foundation of sociology pertaining to the use of robots instead of humans and the word ‘Robotics’ was also coined by him. In today’s world, work on robots, that resemble and look almost human, and others which don’t resemble humans in any way, progresses in leaps and bounds. The world has forerunners in this technology like MIT, CMU, Sony, Honda etc. In this world of ASIMO, AIBO, Packbot etc., we have made an attempt to create a device which we dare call ‘Cyborg’. Perhaps the most important work of Isaac Asimov could be considered to be the coining of the 4 Laws of Robotics. One of the fundamental concepts of robots made famous by the Zeroth Law of Robotics by Asimov: “A robot may not injure humanity, or, through inaction, allow humanity to come to harm.” We have tried to create a system which will allow safeguarding of life. We plan to achieve this by way of allowing the robot to take the place of humans in situations which hold a potential threat to human life. Our attempt was to provide a tool to the enforcers of law and order that could allow them to access and assess a situation which could hold avoidable threat to human life.
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INTRODUCTION Statistics show that automotive accidents occur regularly as a result of blind-spots and driver inattentiveness. Such incidents can have a large financial cost associated with them, as well as injury and loss of life. There are several methods currently available to assist drivers in avoiding such collisions. The simplest method is the installation of devices to increase the driver's field of view, such as extra mirrors and wide angle lenses. However, these still rely on an alert human observer and do not completely eliminate blind-spots. Another approach is to use an automated system which utilizes sensors such as sonar or radar to gather range information. The range data is processed, and the driver is warned if a collision is imminent. Also with this, the increasing pollution is of concern. The number of vehicles increasing on road seems never ending and still there has been no takers trying to reduce the pollution caused by them. This can be done if a vehicle is moving on a predefined path and we introduce an electronic mechanism called line follower circuit for it to move. This is a revolutionary step, but; would help to keep the environment in good health. With two bricks on the pile, we have added a surveillance camera on top to complete its automatic features and so have piled up an automated transport system using collision avoider, line follower and path monitoring. For a model we have used a Web camera and have connected it to the laptop so we can demonstrate the working, but in real time we need to use the wireless camera which transmits the data (video and audio signal from the surrounding) to the control base. Our multipurpose project combinationally called an automated transport system can be classified into three sections 1. Collision avoider Collision avoider mechanism is a system used to detect obstacles and stop if any are detected to avoid collisions. 2. Line follower Line follower is a machine that can follow a path. The path can be visible like a black line on a white surface (or vice-versa) or it can be invisible like a magnetic field. In other words, Sensing a line and maneuvering the robot to stay on course, while constantly correcting wrong moves using feedback mechanism forms a simple yet effective closed loop system. As a programmer we get an opportunity to ‘teach’ the robot how to follow the line thus giving it a human-like property of responding to stimuli. 3. Path monitoring It is a camera using system through which the path on which the vehicle is moving can be kept under surveillance and even control it up to a limit. 6
ABSTRACT This report is the documentation of all the efforts that went into the making of CYBORG, our robot, specifically for the automation of transport system. The CYBORG is an intelligent, autonomous ground vehicle that provides a test bed system for conducting research on mobile vehicles, sensor systems, video signals, path monitoring and intelligent control. The purpose of this report is to describe the conceptual design of the vehicle, its components and highlight the unique innovative aspects of our design process. In this fast developing society, electronics has come to stay as the most important branch of engineering. Electronic devices are being used in almost every day to day life application and even industrial application. They are even fast replacing the present vast army of workers engaged in processing and assembling. This project has been made with keeping in mind many aspects like:1. Responsibility towards environment. 2. Possibility of reducing road accidents mishap. 3. Use of advanced technology. 4. Better service for public (in public transport system). 5. Centralized control.
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NECESSITY OF SYSTEM Today technology is replacing itself everyday. A new day begins with some innovative device. But with this increasing development and growth other problems are also coming to existence. We have tried and dedicate this project for the betterment of humanity and our mother earth. Due to errors and poor response of manual systems the need of automation is being felt. One such feeling is being expressed by us in this project. We have a vision that one day every transport system will be automatic and pollution free. This project is just the beginning and giving a base to our vision. Automation is a huge field in itself and thus not going into deep, here we only mean the dictionary meaning of it. The safety and reliability demanded by the people can be given with utmost efficiency using automation. Road accidents, pollution, violation of traffic norms, rash driving, linearity, fuel efficiency; these are some of the problems and necessity which can be fulfilled with our Cyborg.
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MARKET SURVEY
In today’s automobile market there are around 20 car companies, with around 65 subsidiary company under them, manufacturing various models around the world. Some of these companies even manufacture public transport vehicles like buses, trams etc. But none of these have come up with any automated transport system idea to be implemented on road. These kinds of models are basically only on papers and are not put into effect for decades. They are various hybrid and eco-friendly vehicles coming up in the market but to no avail they have many limitations and moreover are not common among people and so less sold. Also the municipal cooperation is experimenting with the latest technology and new ideas. They have started BRTS (Bus Rapid Transport System) which has dedicated traffic route for buses and no other vehicles are allowed to cross the barrier and drive on that lane. Our system just fits in it perfectly as an addition or improvement. When we questioned the general public about the implementation of this project, their answers were positive, because today every particular person is getting aware and nobody thinks their life to be so worthless that they can lose it on mere traffic road in a reckless accident.
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This is the basic phenomenon of obstacle detection which helps every human being to avoid the obstacles. The rays of the SUN fall on obstacle and are reflected in the surrounding atmosphere. Human eyes detect these reflected rays with the help of many cone & rod shaped cells (tissues) present in the eyes. This information is send to the brain and appropriate control action is taken by the human. An equivalent principle is used in this project. We are using ultrasonic and LED-LDR combination as sensors to detect the obstacles. The same principle is used for line follower too.
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BLOCK DIAGRAM
ULTRASONIC RECEIVER VOLTAGE AMPLIFIER
VOLTAGE AMPLIFIER
CD 4049 BUFFER
MICRO CONTROLLER ATMEL ATMEGA16
LDR 1 and 2
ULTRASONIC TRANSMITTER
LED 1 and 2
LED 3 and 4 LDR 3 and 4
L293D MOTOR DRIVER IC
MOTOR 1
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MOTOR 2
BLOCK DIAGRAM EXPLANATION Voltage amplifier
There are two voltage amplifiers used. The operational amplifier is connected in non-inverting configuration with gain 3 for transmitter and with gain 4 for receiver for ultrasonic sensors. 4049 Buffer IC
This buffer acts as a driver IC for the sensor. It increases the capability of micro controller output signal and is then given to the sensor input. In other words the final signal to the sensor is a stimulated signal value. Ultrasonic transmitter 12
Ultrasonic transmitter as the name suggests it continuously transmits the frequencies. The frequencies are in ultrasonic range i.e. greater than 20 kHz. These frequencies can be easily controlled by the micro controller. The transmitter continuously transmits the frequencies of 40 kHz. These transmitted bursts are detected by the receiver. These detected pulses are mainly the echo pulses from the obstacles. Thus the pulses detected are mainly echo pulses from the obstacles. The diagram shows the circuit used to generate ultrasonic frequency using 555 IC. We have obtained this purpose through the microcontroller. The detection of these pulses is carried out by the receiver described below.
Ultrasonic receiver 13
Receiver receives the echo pulses when the pulses emitted by the transmitter are reflected from the obstacle. These pulses are received by receiver only if any obstacle is found. The received pulses are processed by the on chip ADC of the micro controller. For every particular distance of the obstacle the signal value of the receiver is fixed and can be found using calibration process. This value can be then taken as a reference value in the program for controlling the speed of the motor. Micro controller AT mega 16
This is the heart and brain of the circuit. It performs the following functions 1. Give 40 kHz burst frequency output for ultrasonic sensor 2. It also gives biasing voltage to LED. 14
3. It takes input from LDR and ultrasonic receiver on ADC available on-chip. 4. Converts the track input signal from LDR and decides whether to move straight or take a turn. 5. Converts the ultrasonic receiver signal for obstacle detection. 6. Stop the Cyborg if any obstacles are detected. 7. Give control signals to motor driving IC for movement. 8. Generate Pulse Width Modulation signal for motor. LED and LDR
There are four LEDs used for OBSTACLE DETECTION on the two perpendicular sides and line follower at the bottom. This is a simple photo optic arrangement in which LED keep emitting light continuously. For line follower the colour of the line to be followed is white and LED 1, 2 and LDR 1, 2 are used. By calibration process the reflecting value of the light from white surface which is a fixed and unique can be determined and kept as a reference. This reference value can then be used to check if white line is detected and then take proper movement actions according to the line. For this purpose the line has to be continuously scanned. 15
For detection of perpendicular obstacles LED 3, 4 and LDR 3, 4 are used. These are calibrated for white obstacle as the reflection from white surface is highest. This value is taken as reference, so whenever there is an obstacle for the pre defined range; the reference value and the input value at that instant become equal and the vehicle stops. It is light dependant resistors whose value changes in accordance to the light incident on it. When the obstacle comes in to the proximity the light is reflected back from it and its resistance changes leading to change in voltage. This voltage is given on the ADC channel of microcontroller for comparison with the reference value earlier obtained from calibration. If the reference value equals to the incoming signal then the BOT stops immediately.
Motor driving IC L293D
This is a driver IC used to drive and control the DC motor .It has four channels for motor control. But we have combined four channels into two in order to control the motor direction along with its speed. It also has a separate enable for two channels. The PWM signal generated by the micro controller is given to clock1 and clock2 pin. 16
DC Motor
Motor converts electrical energy into mechanical energy. The PWM generated by the Micro controller is given to the pins of 293D which determines the speed of the motor. The main function of the motor in our BOT is for its movement. The speed of the motor is determined by the ON time and OFF time of the PWM wave.
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SOFTWARE DEVELPOMENT
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CALIBRATION Calibration is a process used to determine the proper functioning of the sensors at ideal conditions. We also get the reference values for further calculations. In our project we are using two sensors i.e. ultrasonic and LDR and so we require two different calibration processes, although the basic steps remain the same. ULTRASONIC SENSOR CALIBRATION 1. Write a program to generate 40 kHz burst frequency and give output on portB pins and connect that pin to the input of the sensor. 2. Take input of sensor on the ADC channel7. 3. Put the ADC output on the peripheral board to ON the corresponding LEDs. 4. Download the program using parallel port on the chip 5. Disconnect the mother board from the computer and connect the sensor and the port pin on port pin as described in the program. 6. Switch ON the supply and common all the ground terminals of boards. 7. Now first put obstacle at required range for maximum reference and see the value on LED and note it. 8. Next put the obstacle at another range if required and see the value on LED. LDR CALIBRATION 1. Connect the on chip Vcc to the sensor Vcc input and common all the grounds. 2. Connect the output of the LDR to the ADC channel 7.
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3. Give the output to the peripheral board and check the output when obstacle is placed on sides and also check the output for black and white lines. 4. This is reference value for side obstacles and line follower mechanism.
ALGORITHM 1. Start 2. Include standard library functions 3. Define different functions and variables. 4. Configure ports, PWM and ADC. 5. Generate burst ultrasonic frequency on port B 6. Convert the received input signal from ultrasonic sensor using ADC channel7 into digital equivalent and storing it. 7. Configure ADC channel 6 to convert the analog signal of right line follower sensor storing it. 8. Clear ADC interrupt flag 9. Configure ADC channel 5 to convert the analog output of left line follower sensor and save this value. 10. Clear the ADC interrupt flag 11. Configure ADC for channel 4 to convert the analog output of the front left perpendicular detection sensor LDR and save this value 12. Clear ADC interrupt flag. 13. Configure ADC for channel 3 to convert the analog output of the front right perpendicular detection sensor LDR and save this value 14. Clear ADC interrupt flag. 15. Configure ADC for channel 2 to convert the analog output of the front LDR and save this value 16. Clear ADC interrupt flag. 20
17. Compare the output values if the bottom sensor with the calibrated value.
(i)
If the output of right sensor>left sensor, then turn left.
(ii)
If the output of left sensor >right sensor, then turn right.
(iii)
If the output of left sensor = right sensor, then go straight.
18. Compare the output values of the front sensor with the calibrated values i)
If the obstacle is detected at any sensor stop the Cyborg immediately.
ii)
If no obstacle is detected, keep moving.
19. Once the obstacle is detected and the BOT stops start its movement again. 20. End
ALGORITHM FOR CALIBRATION 1. Start 2. Include library functions 3. Configure ports A as input and C as output 4. Configure ADC 5. Left shift the output 6. give the output of ADC present on ADCH on Port C. 7. go to step 3. 21
FLOWCHART
START
DECLARE FUNCTIONS AND
B
CONFIGURE PWM, ADC, PORTS
GENERATE 40 KHZ BURST SIGNAL YE S IF
NO
Ultra_ldr>
STOP
YES
I F Frontright >cd && frontleft>c d
NO STOP
22 A
A
I F LF_R>CD
YES
IF
YES MOVE STRAIGHT
LF_LEFT>CD
NO
IF LF_R>CD
YE S
TURN LEFT
N O
B
I F LF_R
TURN RIGHT
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Program #include
#include void config_ports(void);
defining functions
void config_pwm(void); void config_adc7(void); void config_adc6(void); void config_adc5(void); void config_adc4(void); void config_adc3(void); void config_adc2(void); void freq_gen(void); void motor_speed(void); void motor_stop(void); void motor_right(void); void motor_left(void); void motor_normal(void); int main(void) { while(1)
continuous loop
{ char unsigned ultra_sensor,ultra_ldr,linefollower_right,linefollower_left,front_right,front_left; config_ports();
calling functions
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config_pwm(); freq_gen();
generating 40KHz burst frequency for ultrasonic sensor
config_adc7();
ULTRASONIC SENSOR
ultra_sensor=ADCH; PORTC=ADCH; config_adc6();
LINE FOLLOWER RIGHT SENSOR
linefollower_right=ADCH; PORTC=ADCH; config_adc5();
LINE FOLLOWER LEFT SENSOR
linefollower_left=ADCH; PORTC=ADCH; config_adc4();
OBSTACLE DETECTION FRONT SENSOR1
front_right=ADCH; PORTC=ADCH; config_adc3();
OBSTACLE DETECTION FRONT SENSOR2
front_left=ADCH; PORTC=ADCH; config_adc2();
ULTRASONIC SENSOR
ultra_ldr=ADCH; PORTC=ADCH;
TESTING FOR OBCTACLE ALONG WITH LINE FOLLOWER
if(ultra_ldr>0xcd)
NO OBSTACLE
{ if(front_right>0xcd && front_left>0xcd) { if(linefollower_right >0xcd)
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{ if(linefollower_left >0xcd) { motor_normal(); } else { motor_left(); } } else { motor_right(); } } else { motor_stop(); } } else { motor_stop(); } }
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} void config_ports(void) { DDRA=0x00;
Input
DDRB=0xFF;
Output B
DDRC=0xFF;
Output C
DDRD=0xFF;
Output D
} void config_pwm(void) { TCCR1A=0xA1; TCCR1B=0x09; OCR1A=0x00e0; OCR1B=0x00e0; TIMSK=TIMSK&0xC3; } void config_adc7(void) { ADMUX=0xE7; ADCSRA=0xA8; SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { }
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} void config_adc6(void) { ADMUX=0xE6; ADCSRA=0xA8; SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { } } void config_adc5(void) { ADMUX=0xE5; ADCSRA=0xA8; SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { } } void config_adc4(void) { ADMUX=0xE4; ADCSRA=0xA8;
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SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { } } void config_adc2(void) { ADMUX=0xE2; ADCSRA=0xA8; SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { } } void config_adc3(void) { ADMUX=0xE3; ADCSRA=0xA8; SFIOR=0x00; ADCSRA=ADCSRA | 0x40; while((ADCSRA & 0x10) != 0x10) { }
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} void freq_gen(void) { unsigned char i; for(i=0x00;i<0x02;i++) { PORTB=0xFF; _delay_us(12); PORTB=0x00; _delay_us(12); } } void motor_normal(void) { PORTD = PORTD & 0xB7; } void motor_left(void) { PORTD = PORTD & 0xB7; PORTD = PORTD | 0x08; } void motor_right(void) { PORTD = PORTD & 0xB7; PORTD = PORTD | 0x40;
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} void motor_stop(void) { TCCR1B=TCCR1B & 0xF8; }
PROCEDURE 31
It consists of three main sections namely obstacle detection, line follower and path monitoring. It is considered that all the sensors are calibrated and the reference value is known. The following procedure is combined for all three sections. 1) Draw the path on a black chart paper with a white line showing the track. 2) Place the BOT on the starting point of the track. 3) Connect the 12 volt adapter to the peripheral board. 4) When all these connections are made the BOT starts moving; following the line. 5) Now for demonstration put an obstacle on the perpendicular side and check if the vehicle stops. 6) Put another obstacle at ultrasonic sensor range and check if it stops immediately. 7) Also check if it is moving with linear characteristics along the line drawn. 8) After it stops, it should also start moving when the obstacle is removed. This enables the continuous movement of the Cyborg.
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PCB DESIGNING PCB’s are divided into many classes according to several arbitrary-overlapping criteria. First division is into profession and non-profession or counselors. Second division is related to the number of layers of conductors and to the presence of planted through holded. 1. Single sided PCB 2. Double sided PCB 3. Multilayer PCB Third division is based on the insulating material according to this it can be divided into rigid flexible and hexi-rigid combination. Other is dependant on the density pattern 1. Single sided PCB This type of PCB has conductive layer on soldering side only .it is often produced simply by screen printing pattern on the proper clad laminate and etching the excess copper. 2. Double sided PCB This PCB has conductive layers on both sides of the board. If the holes are none plated there is no electrical connection between conductor on one side and those on the opposite side. 3. Multilayer PCB These PCBs have at least three conductive layers. Two of them are on outer surface of the board while remaining is incorporated into insulating board.
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Size and shape The size and shape of the PCB are the important factors in designing the PCB.The maximum size of board is determined by the available facility like the wave soldering station, cleaning lank, component assembling unit etc.when the board size is big and many components have to be mounted on it the probability of the failure of the board increases. Troubleshooting in large boards is difficult. Smaller PCBs are more convenient but have many disadvantage too like wiring is required etc. Precautions 1. Before mounting any components examine PCB for any cracks or defects in conductive paths. 2. Carefully cut the leads of components so that 3mm of the end extends beyond the wire inside the PCB. The ends of the component are bent at right angles to make firm contacts with the surface to which it is to be soldered. 3. In case of components such as transistors, diodes the lengths of the components leads extending above the conductive side should be about 1cm.this will not only serve as heat sink to each head at which soldering is done but also be useful for measuring voltage across the leads.
Soldering technique PCB component installation requires proper soldering techniques are described below 1. A light duty soldering of 25 to 30 watt should be used to prevent the damage to the conductive tracks caused due to heat. 2. Excessive soldering should not be done. 3. Short circuit should be avoided 4. Soldering wax should be used to avoid dry soldering. 5. Solder gun should have a fine tip 6. Soldering angle should be maintained at 450 .
CIRCUIT LAYOUT:34
PERIPHERAL BOARD FOR MOTOR CONTROL
MOTHER BOARD WITH ATMEGA16 MICRO CONTROLLER
COMPONENT LIST 35
SR NO. 1 2 3 4 5 6 7 8 9 10 11 12 13
COMPONENTS IC ATMEL ATMEGA16 DRIVER IC LN293D RESISTORS CAPACITORS LDR LED ULTRASONIC SENSOR PCB DC MOTOR CAMERA MECHANICAL BOT TYRES CASTRO WHEEL
TESTING The system consists of 1. Motor 2. Motor driver IC 3. Mother board with micro controller at mega 16 4. On chip ADC 5. LED 36
QUANTITY 1 1 25 2 5 5 1 9 2 1 1 2 1
6. LDR 7. Ultrasonic sensor 8. Operational Amplifier 9. Resistors 10. capacitors Motor It is a 12 volt 150 rpm motor. It can be tested by applying maximum voltage limit i.e. DC 12 volt from a ripple free DC supply and see if it is working with proper efficiency. Further it can be tested by giving the centre voltage range and check if the speed reduces to half approximately and removing the supply when it is rotate and checking if it stops. The speed of the motor can also be tested either by mechanical or photo pick ups. Motor driver IC The basic method of testing any IC is by simply placing it on the IC tester, enter the IC number and press TEST button. If it shows PASS then the IC working or else it is FAIL.
Mother board with micro controller at mega 16 This is controller board and for testing this various programs have to written on it to check the ports,memory,PWM output and ADC. On chip ADC This is the available Analog to Digital Converter on the micro controller chip itself on port A. It can be tested by giving a dc voltage less than reference and check the output obtained on ADCMUX by sending to any PORT and then connecting that port to the LED input. Vary the signal and check if the digital output is varying. LED 37
LED stands for light emitting diode. Keep the multimeter on the continuity test. Connect the anode to the positive chord and cathode to the common wire. If the LED glows it means it is working with proper reliability. LDR LDR stand for light dependant resistor. Connect the biasing voltage and check the output of the LDR. When there is no light source acting incident on it the output should be maximum and when light falls on it the output voltage varies in accordance to the distance. Ultrasonic sensor We cascaded two 555 IC in monostable multivibrator configuration. First stage generated 2 KHz giving 0.5ms. Second stage generated 40 KHz square pulses. The output pin of the first stage was connected to the reset pin of the second stage. This gave an output as burst frequency signal. This was amplified with a non-inverting OP-AMP having gain of 3. This processed signal was given to the transmitter. CRO probes were connected to the receiver when kept adjacent, perpendicular, with obstacle in front of it. The CRO screen displayed variations which proved that sensors are working and can be used for obstacle detection for a defined range. Operational Amplifier:OP-AMP is connected in non inverting configuration. The gain is set to 3 for transmission and 4 for reception. Give a signal to the input and check the output if it is in multiple of the gain factor. Resistors We have used resistors of various values. The values said by the shopkeeper can be verified using multimeter or colour code. Both the terminal should also be checked for continuity test, which naturally should not occur. Capacitors Capacitors used are of different types and various values. Their values can check using LCR meter. The LCR meter can test all types of capacitors for a wide range.
38
COMPONENT DESCRIPTION DC MOTOR
DC MOTOR converts the electrical energy into mechanical energy. It accepts energy in the electrical form from the DC source and converts it into mechanical energy at its output. It consists of two winding 39
namely field winding and armature winding. The field winding is stationery and armature winding can rotate. We can connect the field winding as well as armature winding to DC supply. The filed current produces the magnetic flux in the air gap between the armature and filed windings and the current carrying conductor is placed in this magnetic field.
Principle of operation: “When a current carrying conductor is placed in magnetic field, it experiences the force.” In case of DC motor, the magnetic field is developed by the field current. The armature winding is connected to an external DC source; hence it plays a role of the current carrying conductor placed in the magnetic field. Due to the force exerted on it, when placed in the magnetic field, it starts rotating.
L293D DC MOTOR DRIVER CIRCUIT:
40
The device is a monolithic integral high voltage, high current four channel driver design to accept standard DTL or TTL logic levels and drive inductive loads(such as relays, solenoids, DC and stepper motors)and switching power transistors. To simplify use as two bridges, each pair channel is equipped with an enable input. A separate voltage input is provided for the logic allowing the operating at lower voltage and internal clamp diodes are including. This device is suitable for use of switching applications at frequencies up to 5 KHz. This IC also permits control of two motors in forward and reverse directions and even their speed. Resistors:
If a battery is connected across a conducting material a certain amount of current will flow through the material. This current is dependent on the voltage of battery, on the dimension of the sample and the conductivity of the material itself. Resistors with known resistance are used for current control in electronics circuits. The resistors are made from the carbon mixtures, metal films or resistance wire and have two connecting wire attached. Variable resistors commonly called potentiometers or POT with an adjustable sliding contact arm are often used to control biasing or supply voltage to a particular circuit. Capacitors:
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Capacitors consist of two metal plates that are separated by an insulating material. If the positive terminal of the battery is connected to one of the plates and negative terminal to other, equal and opposite charges will accumulate of the two plates. This will continue until the potential difference between the plates equals the battery voltage. If the battery is disconnected, the capacitor retains the charge and the voltage associated with it, until the change has slowly leaked away through the insulating material. Rapidly changing voltages, such as those caused by an audio or radio signal produces larger current flows to and fro from the plates; the capacitor then function as conductors for changing current. Camera:
We have used a camera placed on the cyborg which monitors the path continuously. This is for the model purpose. If implemented, wireless camera will have to be used .It will transmit the RF audio signal and video signals of the surroundings with the help of in build RF transmitter. These signals are received by the RF receiver which is connected to TV. A TV camera performs dual function of converting the optical image of the television scene into an electrical image then scans this image with an electron beam to produce electrical signals which vary in accordance with variations of light intensity. Different types of TV camera tubes employ different techniques of converting the optical image although the scanning method is same in each case. The
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principle of photo-emission and photo-conduction are used for conversion of optical image to an electrical signal. LED
A light-emitting diode (LED), is an electronic light source. The LED was first invented in Russia in the 1920s, and introduced in America as a practical electronic component in 1962. Oleg Vladimirovich Losev was a radio technician who noticed that diodes used in radio receivers emitted light when current was passed through them. In 1927, he published details in a Russian journal of the first ever LED. All early devices emitted low-intensity red light, but modern LEDs are available across the visible, ultraviolet and infra red wavelengths, with very high brightness. LEDs are based on the semiconductor diode. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical components to shape its radiation pattern and assist in reflection. LEDs present many advantages over traditional light sources including lower energy consumption, longer lifetime, improved robustness, smaller size and faster switching. However, they are relatively expensive and require more precise current and heat management than traditional light sources. Applications of LEDs are diverse. They are used as low-energy and also for replacements for traditional light sources in well-established applications such as indicators and automotive lighting. The compact size of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are useful in communications technology.
LDR
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A photo-resistor or light dependent resistor or cadmium sulfide (CdS) cell is a resistor whose resistance decreases with increasing incident light intensity. It can also be referenced as a photoconductor. A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron (and its hole partner) conduct electricity, thereby lowering resistance. A photoelectric device can be either intrinsic or extrinsic. An intrinsic semiconductor has its own charge carriers and is not an efficient semiconductor, e.g. silicon. In intrinsic devices the only available electrons are in the valence band, and hence the photon must have enough energy to excite the electron across the entire bandgap. Extrinsic devices have impurities, also called dopants, and added whose ground state energy is closer to the conduction band; since the electrons do not have as far to jump, lower energy photons (i.e., longer wavelengths and lower frequencies) are sufficient to trigger the device. If a sample of silicon has some of its atoms replaced by phosphorus atoms (impurities), there will be extra electrons available for conduction. This is an example of an extrinsic semiconductor.
Atmega 16 44
The ATmega16 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega16 achieves
Throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed. Operational amplifier
An operational amplifier, which is often called an op-amp, is a DC-coupled high-gain electronic voltage amplifier with differential inputs and, usually, a single output. Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation. High input impedance at the input terminals (ideally infinite) and low output impedance (ideally zero) are important typical characteristics. Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices. Many standard IC op-amps cost only a few cents in moderate production volume; however some integrated or hybrid operational amplifiers with special performance specifications may cost over $100 US in small quantities. Modern designs are electronically more rugged than earlier implementations and some can sustain direct short circuits on their outputs without damage. The op-amp is one type of differential amplifier. Other types of differential amplifier include the fully differential amplifier (similar to the op-amp, but with 2 outputs), the instrumentation amplifier (usually built from 3 op-amps), the isolation amplifier (similar to the instrumentation amplifier, but which works fine with common-mode voltages that would destroy an ordinary op-amp), and negative feedback amplifier (usually built from 1 or more op-amps and a resistive feedback network). 45
CD 4049
These hex buffers are monolithic complementary MOS (CMOS) integrated circuits constructed with Nand P-channel enhancement mode transistors. These devices feature logic level conversion using only one supply voltage (VDD). The input signal high level (VIH) can exceed the VDD supply voltage when these devices are used for logic level conversions. These devices are intended for use as hex buffers, CMOS to DTL/TTL converters, or as CMOS current drivers, and at VDD e 5 volts, they can drive directly two DTL/TTL loads over the full operating temperature range.
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ADVANTAGES
It is an automatic system, so need of driver is eliminate but a supervisor is essential. Human errors can be avoided (accidents are reduced). Efficient and pollution free. Transportation system becomes reliable. Traffic rules are followed. Safety is assured. Great and a very wide scope of future expansion. Can be implemented in present on the BRT tracks.
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DISADVANTAGES
As everything has two sides so does our project.It has the following limitations
Sensors can get damaged due to excessive heat. Skilled people or engineers are required. Sensors are costly. Ultrasonic transmitter requires a constant 40 kHz, 10 volts supply. Initial cost is high. Repair and maintenance is hard. Failure can cause a big chaos on the roads. If the circuit is malfunctioning or somebody hacks into the programming accidents can occur.
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OBSERVATION & TROUBLE-SHOOTING When we were given the assignment of this project, we first started searching for all the possible information about the microcontroller 8051, circuit required, Astable Multivibrator, amplifiers & mainly the sensors which can be used for our project. We gathered information regarding different sensors which are used for obstacle detection purpose. We found ultrasonic sensors, infrared sensors, digital cameras, common radar, proximity sensors etc. After a detailed study of all sensors we decided to use ULTRASONIC SENSORS for our project as it had a lot of advantages on other sensors. The major disadvantage of infrared sensors was that they cannot detect the obstacle in foggy weather (in winter) and completely black body. Then we went through a wide range of ultrasonic sensors & we selected the SR-04 & TR-04 ultrasonic sensors. We were told to use microcontroller 8051 in this project. We searched on internet & collected information from different books regarding different obstacle detection circuits using ultrasonic sensors. At first we divided the main project in different sections like speed control of motor & transmitter and receiver section. We read the book of LINEAR INTEGRATED CIRCUITS by Ramakant Gaikwad & got information about the motor speed control. The circuit consisted of frequency-to-voltage converter IC 9400, a magnetic sensor and it also required ADC 0808. After detailed study we came to know that the o\p was inconsistent and not accurate. So we decided not to use this circuit.
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Initially we had decided to use stepper motor but we were advice to use simple DC motor, as stepper motor windings added to circuit complexities. We had to control 2 dc motors so we decided to use DC MOTOR DRIVER IC L293D (details of which are given below). This IC required +12 volt dc supply. The ultrasonic transmitter and receiver required amplifier stages for their proper working. We decide to use 4049 buffer IC at the transmitter end and an amplifier using IC 741 at the receiver. We designed a astable multivibrator circuit using IC 555 on the bread board and made the necessary connections. At first we did not get the o\p on CRO. We rectified our mistakes & avoided lose contacts & we were able to get 35 KHz square wave o\p. We also designed a DAC circuit but it did not work. We studied the designed circuit connections but were unable to know the exact reason behind the failure of the circuit. We also discuss this problem with our project guide Prof. C.R.JOSHI. He advised us change the IC and try again. By this time we had bought the 8051 development board kit and also made the necessary connections. By the time we also tested the output of the ultrasonic sensors. We gave the input 40 KHz square pulses to the transmitter from IC 555(astable multivibrator) via buffer IC 4049. We connected receiver to the CRO but we failed to get the output. Rectifying some of the lose connections, we again tried and this time we got the output nearly 2.4 volts. As we changed the distance between the transmitter and the receiver the o\p voltage as well as frequency was varying, but only to some extent. We were suggested to use an amplifier stage between the receiver and the microcontroller. As we were finalizing the circuit connections we came to know about another microcontroller ATMEGA 16 with a no. of additional features like on-chip PWM generation & on-chip 8-channel ADC. This was a plus point for us. We immediately reported this thing to our project guide Prof. C.R.JOSHI sir and he gave us the permission to use ATMEGA 16 for our project. We studied the datasheet of ATMEGA 16 thoroughly. We decided to use LED-LDR combinations as sensors along with the ultrasonic sensor. We first wrote programs to initialize the distance at which the obstacle is to detected .We then wrote programs required for obstacle detection and line follower on our own and burned them on the chip. We then made the necessary connections with the peripheral board. Initially we did not get the expected output so we checked the hardware and software both. The connections were perfect and the program was also right. On testing many times we came to know that the sensitivity of the LED-LDR was very low. We discussed with the experts about this problem and they suggested us to increase the value of resistance across the LDR. After rectifying this mistake the sensitivity of these sensors increased to a great extent i.e. from 4 cm to 26.5 cm. Finally we made the final connections of our project. We made a small wooden vehicle and placed our PCBs in that cart, placed the 50
sensors at the right positions and gave +12 volt supply to the kit and we were able to get the desired output. At last we achieved success after such hard work and trouble-shooting.
FINANCIAL AUDIT The following is the list of components and their prices which were used during the project. Start of project:-23/7/2009 End of project:-21/4/2009 Component name
Quantity
Amount
Bread board
1
70
89c51
1
55
8051
1
5
Wire stripper
1
25
Driver IC L293D
3
225
DAC 0808
2
70
IC 555
4
24
IC 741
2
10
CRYSTAL 12 MHz
1
6
IC 7805
1
7
IC 7809
1
7 51
IC 7812
1
7
CAPACITORS
6
2
RESISTORS
15
4
MOTOR
2
340
ULTRASONIC SENSOR
1
350
CRYSTAL 24 MHz
2
12
DEVELOPMENT BOARD
1
50
CD 4049
2
14
LM 324
2
10
7915
1
7
7912
1
7
7909
1
7
SWITCHES
1
4
DIODE 1N4007
2
2
10 PIN CONNECTOR
4
14
IC HOLDER
3
10
GENERAL PPURPOSE PCB
4
44
CLAMPS
2
30
TYRES
2
150
CASTRO WHEEL
1
20
NUTS & OTHERS
4
30
ATMEGA 16 BOARD
1
800
PERIPHERAL BOARD
1
600
LED
5
10
LDR
5
35
LDR SENSORS
2
100
BATTERIES
5
100 52
DOUBLE SIDE TAPE
1
10
CHART PAPER
5
35 TOTAL COST
3308
THE ABOVE PRICES ARE EXCLUSIVE OF HUMAN RESOURCE COST.
LEARNING EXPERIENCE It is often said that “learning is a versatile and a continuous process.” When we learn something we start with its basics. For example take our mother tongue. We first learn the alphabets, sentences and then start conversation. It is similar for learning all other concepts and engineering techniques. Hence we started with the basics of our circuit. It was our first time when we got exposed to the practical world with such freedom. We began with a happy start. All of us had loads of ideas everyday coming to our mind. Some were proceeded and few were suppressed. It was fixed from the beginning that we are not going to do this just for academic purpose. We had a wide view and thought about the common people, automation, technology, environment health and many more aspects. We began with the topic automated transport having collision avoider, line follower, automatic announcement, traffic signal detection. This was a rough view of a complete automated transport system. We started searching for information on these 4 blocks. First easiest way to do this was googling (searching information on www.google.com). We found different types of sensors, microcontrollers, driver ICs, motor, some before hand projects with same features and lots of other circuits and block diagrams. After a lot of study and research analysis we found that it would be wise to go forward only with obstacle detection if we were going to use 8051.
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So we started designing circuit and other peripheral components. We found the whole circuit and started preparing for the seminar. We gave presentation on obstacle detection using ultrasonic sensor with microcontroller 8051 as the main processing unit. In the even semester we had attended a robotics workshop organized by the college. The syllabus for the course included microcontroller Atmega16 and using this we had to make obstacle detection, line follower and remote control robot. So we learned and decided to upgrade as it would allow us to add line follower as an extra feature and also we could show path monitoring. Not completely automatic but at least we could do half of it. One major learning experience was, there is a big difference between theory that we learn everyday in class and the practical that we perform on the field. It takes lots of patience and knowledge to obtain the desired output. After all electronics is a field of complete imagination. It was a great pleasure to be guided by Prof C.R. Joshi who is the head of the department and a renowned teacher. We learned many things from him and we will always remember him and the principles explained by him.
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CONCLUSION In this report we have summarized the project objectives, the methodologies applied and the major project results achieved in COLLATE. Rather than describing all project activities and achievements in much detail, the report gives a relatively concise overview and points out the main characteristics that distinguish our developments from other, comparable projects or implemented systems.
Planning robotic motions is a very active field of research. In this report a literature exploration has been conducted to investigate the possibilities for robotic motion planning, to learn from previous implemented projects and to search for interesting gaps in mobile robotic motion planning which are still to be investigated. Literature shows that robotic motion planning in general can be divided into implicit and explicit motion planning. Explicit schemes calculate the complete trajectory before the motion is executed, implicit trajectories are calculated during a traversal, using the state of the robot and the environment. The field of wheeled mobile robotic systems have introduced some specific strategies for obstacle avoidance. These strategies can be separated into three categories; classical motion planners, heuristic planners and "complete and correct'' sensor-based path planning. Classical motion planner’s posses the very useful properties of correctness and completeness, but need a prime knowledge of the complete environment to deliver a motion plan. The three most important classical planners are roadmap, cell decomposition and virtual potential field algorithms. Rodma? algorithms use different mappings to determine an obstacle free road between the current and the desired position. Cell decomposition algorithms divide the space into two parts, free space and obstacle containing space. Cell decomposition algorithms do not produce hard-to-follow onedimensional curves but give save corridors between obstacles; this puts less pressure on tracking controllers but imply that a second algorithm has to be constructed which selects one path out of the infinite possibilities. The last important subclass constructs a virtual potential field, where the robot gets a virtual positive potential, the goal an attractive negative potential and every single obstacle a repulsive positive potential. Now letting physical laws do their work, some path will follow. Big setback to this method is the risk of local minima. Solutions to this problem have been propos2d, but tuning requires extensive knowledge of the environment, losing generality of the method. Classical methods can all be categorized into the class of explicit motion planners. Heuristic planners on the other hand require no a priori knowledge of the environment, using only sensor inputs and robot states. All heuristic planners select an action out of a preprogrammed list of commands based on local criteria. Not requiring complete a priority knowledge of the environment is the main value of this class, but in practice these methods resolve mainly in very long paths, because no optimalisation of what so ever can be conducted.This class is completely implicit. The last class has been developed combining the positive properties of both previous described classes, gaining "complete and correct" sensor-based path planning, Most classical methods have now been redesigned into a sensor-based variety. This is the class where most research activity is positioned nowadays. Because the trajectory is not completely calculated before motion execution, this is an implicit class of motion planners.
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Looking at implemented projects four areas can be distinguished. First of all the research test beds on which different methods are tested on lab scale. The second area is the automotive industry, especially the American Automated Highway System project. In this project cars are designed which are capable of highspeed driving very close to each other considering avoidance of possible obstacles. A lot of research effort is put into the area of space exploration. Main players in this field are the American NASA and the European ESA space organizations. Especially NASA's Jet Propulsion Lab has put lots of effort in developing wheeled mobile space robots for the exploration of the planet Mars. The last area is much smaller than previous areas but not less interesting. This area contains implementations to help daily life and navigation of handicapped people, especially visual limited people.
SYSTEM DOCUMENTS
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