Linefollower

May 2017

This robot was created for the VIVES line following competition. This competition consists of building a robot that needs to follow a white line on a black background. This robot won 3 consecutive years in a row.

Creating the frame

The first step was creating a frame to house the motors, PCB and sensors. Making this from aluminum adds a little weight to improve traction when compared to plastic. This frame was cut from a large 3mm thick aluminum sheet with the help of a jigsaw. Holes are drilled from mounting the various components.

Choosing the sensors

To find the line some kind of sensor is needed. While a color sensor would suffice, an IR sensor is used since it has a faster response time. IR light is emitted and the amount reflected is read from a receiver. A black surface will absorb more than a white surface. Placing 8 sensors next to each other can then localize the line.

Programming

Programming is done by first reading the value from each sensor. By summing all values and dividing by positioning offset, the location of the line can be determined. This location is then fed into a pwm generator. The pwm signal for the right motor is increased when the line is detected on the left to correct the line back to the center.