NXT Line Following

There are a number of methods which can be used to build a line following robot.  In general there are three different types of line followers:

  1. Single light sensor model
  2. Two light sensor model
  3. Three light sensor model

Of these three models the most versatile, relatively reliable and easier to construct is the two light sensor model.  It further can follow more easily black lines which go any direction.  Where the single sensor models are either left or right turning favoring.

Line Following Learning Resources

Below are a number of PDF’s with basic instructions on experimenting quickly with the various line following methods as described in more detail on the accompanying web pages.

Placement of Light Sensors


Where the light sensor is positioned makes a big difference in how well the robot follows an given line.  In general placing the light sensor ahead of the wheels (motors) allows the robot to react more accurately to upcoming course (line) changes.  You may want to experiment with the placement of the sensors and the distance between the sensor and the driving wheels.  Experiment with placing the sensors behind the driving motors and observe the effects this has on the accuracy and fluency of the robot as it tries to follow the line.