Engineering Design Project Department of Computer Science and Engineering University of MoratuwaGroup 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
A machine which is built to followa specific path is defined as a LineFollower. The line may have differentappearances A Black line on a white surface or vice-versa. An Invisible line as a magnetic field.
• Basic knowledge about electronic components.• Basic knowledge on electronic circuit designing and making.• Basic knowledge on C Programing.• Innovative brain and perseverance.
As we analyze the problem werealize that we have to get seveninputs and four outputs. So wedecided that the most suitablemicrocontroller for our requirementsis the 16F877A microcontroller. It consists of four input/outputports and PWM module. Thispersuades us to use it in our circuit.
We have used seven IR sensors and belowyou can see the arrangement of those sensors. 1 6 4 2 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.
The IR LED emits a beam of IR and thesurface below reflect the beam. When thesensors senses the beam it generates avoltage. This voltage depends on theamount of the light sense by the sensor.When the intensity is higher the generatedvoltage is higher and when the intensity islower the generated voltage is lower.
We used three circuit panels tocomplete the robot. Analog to Digital Converter PIC Simulation Circuit Motor Interface and Control Circuit
Analog output given by the sensors is converted todigital by the above circuit .
This part of circuit can be consideredas the mother board of our robot. The circuit gets all the outputs ofsensors as the inputs of the PIC. Then thePIC gives us required outputs. According to the design of this circuitwe can also program the PIC while it isattached to the circuit.
This part of circuit controls the motors according to the outputsgiven by the PIC.
We used PIC C language to programthe IC. We used PIC C because it isfamiliar to us and similar to C language. We have written the program asgetting inputs from the sensors androtating the motors forward and backwardaccording to our requirements.
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.
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=ADGEEShm4TXBoqBpvNTwSc bQKoI_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