In my last post, I compared different ways how to control your robot, in this post I will be sharing my experiences for selecting the sensors and method for controlling my robot for the PiWars challenge Proximity Alert. So what is Proximity Alert challenge about?here’s a quote about it from the PiWars website,
Your robot will proceed autonomously from a start line and will use sensor(s) to prevent hitting a wooden wall 1.5 metres away. It will do this a total of 3 times. After each approach and stop, you will retrieve your robot and carry it to the start line. No part of the robot is permitted to touch the wall, so tactile sensors ‘feeling’ the wall would constitute a failure.
from the above quote, rules out using a tactile sensor, so using a micro switch and/or pressure sensor is not possible, so that leaves the choice of using a range finder sensor, measuring the distance your robot travelled from the start line ( Dead reckoning ) or image processing. The below methods, don’t allow for drift. Drift is where your robot will not move in a straight line, and is caused by at least one or all of the following; poorly matched motors, surface conditions, an uneven surface and wheels slipping. First let go over the pro’s and con’s of each method and types of sensors.