Saturday, March 22, 2014

LINE FOLLOWING ROBOT -III


Hello again.. so far we discussed about the sensor panel and the motor drive system of the line follower.. In order to finalize this, we need to program it and finish the structure.. From this article I will explain about the control system and the structure..


Controller

The earlier connected sensor panel and the motor drive system should be connected in order to make the robot work according to the senses received by the sensors. That part is done with the use of Arduino Board. The sensor arrays are connected to the arduino through analog pins and sensor panel gets power to its operation from the arduino (52 port).


Figure 1- The Arduino Board

According to the sensor values received, the arduino is programmed to pass a PWM value to In1, in2, IN3 and In4.This PWM value allows to control the speed of the motors.

PWM (Pulse With Modulation ) :

PWM technology is used to control  the speed of motors. Here the process of varying the width of voltage pulses takes place.


Figure 2- PWM Waveforms

According to the figure above, it is clear that by varying the existing time of high (12V) and low(0V) voltages, the average voltage of each instance can be changed. Therefore the speed can be changed. Here the maximum PWM value is 255 and minimum is 0. By assigning any value in between these to values, the rotation speed of the motors can be controlled.



Structure


The structure is done with Perspex .This has 3 wheels where two main wheels are directly connected to the 2 motors. The 3rd wheel is at back . At the front , the sensor panel is connected closer to the ground.



Figure 3 - The final structure without circuits


Figure  4 –The Final Line Following Robot


I have not given the arduino coding or the program for the bot.  It is because the code is something to think and do..I hope you will be able to do the correct coding and complete the simple line following robot.. 

Now I think you got a basic understanding about the line follower and Thank you very much for reading..




Special Thanx to Vibhatha, Lakshan, Anuradha and Prabhodi






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