GajRaj: An autonomous vehicle using image processing

'GajRaj'... What is there in name !
Here , Everything there is in name.

'GajRaj' is the one of the biggest robot presented ever in IIT Kharagpur . This robot is presented in '8mile' by a team of IIITM consisting of Vishal Pradhan (Team Leader, IPG2005), Nishant Kolhe(IPG2008), Shashank(IPG2008), Manish Sharma(IPG2008), Shashank Sukumaran(IPG2008) in Kshitij 2009 and won third prize there.

PROJECT DETAILS

1) Name of the Project : Wall-E

2) Brief description (200 words) : Our project is a three wheeler petrol driven autonomous vehicle, which is designed to run on road, follow divider lines , detect zebra crossing and traffic signals (red & green lights ).It has a 55 cc two stroke engine which runs on petrol and has three powerful servo motors for steering ,acceleration and brake ,attached onto it for precise navigation .It also has a laptop stand attached onto it so that a laptop could be mounted whenever we need to run it on road .The laptop (when mounted) is attached to a PCB (Printed Circuit Board ) via serial port which acts as servo motor controller and gives the commands to the respective servo motors which are being executed by MATLAB(Image analysis & processing tool) on the laptop .It also has three separate high quality cameras(CCD camera & two webcams) for lane detection & traffic light detection respectively attached onto it .The most important and the most

astonishing part of our project is that each and every component of the hardware was carefully handpicked by us from the scrap market (popularly known as LOHIA BAZAR in Gwalior) and was welded and fitted by us .It took approximately 60 days and not mention nights (J) to execute this project.

3) Technical Details :( pictures, principles, circuit/block diagrams, drawings, etc.)

a)The following are the pictures (in different views) of our project :

i) complete bot on the road ( with all components )

ii) Complete bot (With all servo motors indicated )

iii) Complete bot (with lane detection and backup camera indicated)

iv) Complete bot (with PCB, laptop, TV tuner, and over head camera for traffic light

detection indicated)

v) Complete bot ( Zoom view with all hardware visible)

b) Principles used:

i) Internal Combustion Engine & Secondary chassis: The engine can be considered as the heart of hardware and it has the following technical specifications:

· Number of cylinders –One

· Fuel used in the engine –Petrol+20cc oil

· Horse power(B.H.P)-49.5

· Cubic capacity (of cylinder)-55 cc.

The engine operates in four different stages i.e. (injection, compression, ignition, and exhaust) and thus provides the required torque to the primary sprocket/gear which is connected to a smaller secondary sprocket through a chain assembly (this system of gears is used because the efficiency of this system is very high (~60-70%) as compared to other gear systems and it’s also simple to implement as far as the practical application is

concerned), the secondary sprocket is fixed to the rear axle ,which passes through two ball bearings ,which are part of Secondary chassis . This secondary chassis’s main task is to

keep the two tires and the engine stable , and in order to accomplish that we have attached

many support bars which you can easily observe in figure iv).

ii) Servo Motors: These are one of the most important components of the system and are used to navigate (steer, accelerate and brake )the bot .The system has used three servo motors (one mounted at the top of steering neck i.e. steering motor, and two mounted onto the inclined neck i.e. acceleration and braking motor as shown in figure ii) above. The servo

motors are used where we need highly precise turns and high torques(as close to 5 degrees or even less..) , each servo has three terminals i.e. (Vcc, Vgnd & control line terminal), the first two terminals are used for supplying power whereas the magnitude of impulse (in ms) at the third terminal decides the degree of revolution of the motor. The shaft from the motor is connected to circular shaped plastic assembly onto which a wire(i.e. acceleration and brake wire) is attached ,the linear displacement(x) of the wire is related to the angular displacement β of the motor by the relation X=Rβ .From this relation we can easily calculate β max, βmin from Xmax and Xmin respectively.

iii) Printed Circuit Board (PCB): The PCB is responsible for controlling the servo motors; it is connected to the laptop via serial to usb converter. It acts as an interface between laptop and servo motors. The laptop processes the image using MATLAB and sends the signals to PCB where the microcontroller process it and pass the control signals(PWM) to the required servo motor for the required function ( i.e. Breaks, Steering and Acceleration). The detailed figure of PCB is shown below:-

4) Applications of the project : (Expose innovation and commercial applicability)

The aim of the project was to build a system that helps navigate a vehicle by computer aided vision. Our project can be used as basis for further development of ‘smart’ robots for the army as well as for the civil world. Our project can have many useful applications like:

1) Transportation for the Handicapped: the bot can be used as transportation by a slight modification, into a manual robot, by using a joystick, or a few push buttons to control it. Even as an autonomous robot it can be used for the paralyzed, it can transport the paralyzed from one point to another as it can move in traffic, and such.

2) Military Applications: Our bot can be used as an autonomous combat vehicle which can search and intrude enemy’s/terrorists outfits where a manned mission could lead to fatal causalities .The bot will detect enemy’s/terrorists uniform by capturing and processing image’s pixel.

3) Super Market: Our bot can be used in super market for commercial purpose. The bot can follow a white circle with stoppage at various checkpoints from which various items can be loaded into its carts and from there it can take them to the scanning point where the bill can be prepared.

4) Industries: Our bot can be used in various Plants. It can be used to transport/deliver goods and raw materials from one end of the plant to another. The bot can follow the white lane and can stop at red lights to deliver or take goods.

5) Infrastructure requirements: (computer, supplies, etc.)

1) 1 laptop (1GB DDR2 RAM,2ghz centrino, 1 serial port,2 usb ports) with MATLAB Installed. 2) 1 TV Tuner card (analog to digital converter). 3) Serial to USB port converter. 4) Printed Circuit Board having the following components : a) 1 AT89C52 16bit µcontroller. b) 1 RS 232 IC. c) 1 16 MHz Oscillator. d) 1 7805CT transistor (for providing constant voltage (5V)). e) 4 I/O pins (for connecting servo motors and power supply). f) 1 Heat sink. g) 6 (10µF, 50volts, 85 ‘C) cylindrical capacitors+ 3 paper capacitors. h) 2 kill switches (one for applying full brakes and another for zero acceleration). i) 1 servo motor reset switch. j) Jump wires. 5) 1 soldering iron (with flux and soldering wire included). 6) 6volt rechargeable battery with charger (for supplying power to PCB & servo motors. 7) Connecting cables. 8) Steel grip tape. 9) Scrap wire. 10) 9volt battery (for providing power supply to CCD camera).

6) Components involved:

COMPONENTS COST 1) 2-stroke engine+carburettor+ spark plug +silencer Rs.900 2) 3-old Tires Rs.390(3*130 each) 3) Servo motors a) Steering motor Rs 1450 b) Acceleration motor Rs 750 c) Braking motor Rs 750 1) Primary chassis Rs 450 2) Secondary chassis (rear support system) Rs 350 3) Ball bearings Rs 50 (Rs25*2each) 4) Rear Axle Rs 90 5) Laptop Stand Rs 150 6) Cameras a)CCD camera Rs 1200 b)Traffic light webcam Rs 750 10) Rear Suspension Rs 70 11)Nuts and bolts Rs 50(Rs5*10) 12)Front Suspension Rs 40(Rs20*2) 13) Petrol tank Rs 20 14) Alternator Rs 25 15)Chain assembly Rs 410 (primary sprocket +secondary sprocket + chain) 16) Old brake shoe Rs 80 17) Other expenses Rs 750(approx) --------------------------------------------------------------------------------------------------- TOTAL EXPENSE: Rs 8675(approx) ---------------------------------------------------------------------------------------------------