PATH FOLLOWING ROBOT

Engineering Design ProjectDepartment of Computer Science and Engineering

University of Moratuwa

Group Name:- Phoenix• Gunasinghe U. L. D. N 100162X• Sashika W. A. D 100487X• Siriwardena M.P 100512X• Udara Y.B.N 100544V• Wijayarathna D.G.C.D 100596F

The Line Follower

A machine which is built to follow a specific path is defined as a Line Follower. The line may have different appearances

A Black line on a white surface or vice-versa. An Invisible line as a magnetic field.

Prerequisites

• Basic knowledge about electronic components.

• Basic knowledge on electronic circuit designing and making.

• Basic knowledge on C Programing.• Innovative brain and perseverance.

Microcontroller -16F877A

As we analyze the problem we realize that we have to get seven inputs and four outputs. So we decided that the most suitable microcontroller for our requirements is the 16F877A microcontroller.

It consists of four input/output ports and PWM module. This persuades us to use it in our circuit.

Block Diagram of Circuit

Detecting Road

We have used seven IR sensors and below you can see the arrangement of those sensors.

6 4 2

1

3 5 7

Sensors 1,2 and 3 are used to detect the road.

Sensors 4 and 5 are used to recognize the mark given to indicate the side which the robot should turn at the four-way junction.

Sensors 6 and 7 are used to recognize the four-way junction.

Detecting Road ctd..

A Sensor

The IR LED emits a beam of IR and the surface below reflect the beam. When the sensors senses the beam it generates a voltage. This voltage depends on the amount of the light sense by the sensor. When the intensity is higher the generated voltage is higher and when the intensity is lower the generated voltage is lower.

A Sensor ctd..

We used three circuit panels to complete the robot.

Analog to Digital Converter PIC Simulation Circuit Motor Interface and Control Circuit

Circuit Panels

Analog to Digital Converter

Analog output given by the sensors is converted to digital by the above circuit .

PIC Simulation Circuit

This part of circuit can be considered as the mother board of our robot.

The circuit gets all the outputs of sensors as the inputs of the PIC. Then the PIC gives us required outputs.

According to the design of this circuit we can also program the PIC while it is attached to the circuit.

PIC Simulation Circuit ctd..

Motor Interface and Control Circuit

This part of circuit controls the motors according to the outputs given by the PIC.

We used PIC C language to program the IC. We used PIC C because it is familiar to us and similar to C language. We have written the program as getting inputs from the sensors and rotating the motors forward and backward according to our requirements.

Program and Programming the IC

How can we improve the performances of the robot

In this project we didn’t use PWM(Pulse With Module) Method. Because we didn’t have enough knowledge about using it. If we used it we could improve the performances.

Although we use a 6V power pack with a lengthy wire, we could make the robot more portable if we used a rechargeable battery.

References Discussion with Mr. Aruna Upul (Department of

Electronics and Tele communication.)We used following links to get an idea about the

path following robot.• http://robotika.yweb.sk/skola/AVR/visionrobo%20com/Line%20Follower%20tutorial%20v1.1.pdf• http://www.botskool.com/tutorials/electronics/8051/line-follower• http://www.kmitl.ac.th/~kswichit/ROBOT/Follower.pdf• http://www.docstoc.com/docs/64977263/Line-following-robot-tutorial• http://www.richardvannoy.info/building-a-line-following-robot.pdf• http://www.tombot.net/beam/linefollowingcircuit.html• http://www.ermicro.com/blog/?p=1097• http://

docs.google.com/viewer?a=v&q=cache:WXamZCglK3UJ:vjtirobotics.files.wordpress.com/2008/0 9/linefollower_tricks.doc+build+line+follower&hl=en&gl=lk&pid=bl&srcid=ADGEEShm4TXBoqBpvNTwScbQKoI_Wayxn0HBz_QMKTbHpnaf8pVJAK2wPJUIjkFJdz2No0UjmtN8BWTi1BOmqTi0a-QGbgootbW42Px3xw2nz6dY-j_oFezBrJojYMM-QFs84oBD5kjz&sig=AHIEtbS8vwB7pLdTJEJoU0PeJOoDoLeBmA&pli=1

• http://www.youtube.com/watch?v=I_NU2ruzyc4• http://www.youtube.com/watch?v=BLfXXRfRIzY• http://www.youtube.com/watch?v=6QznAAwL8rI

Thank YouWe are