Path Tracking Control of a Differential-Drive Tracked Robot Based on Look-ahead Distance

Abstract

In this paper, a PI path tracking controller based on look-ahead point information for a differential-drive crawler-type robot was developed. The robot is equipped with Global Navigation Satellite System (GNSS) antennas and a receiver module which are used as navigation sensors to obtain real-time estimates of the position and heading errors of the robot. To control the position of the robot with respect to the target path, a look-ahead point was generated by using Euler Transformation. The look-ahead point lateral errors were then controlled by the designed controller. Forward and backward path tracking tests with different look-ahead distances were conducted to examine the controller performance of the robot and the effect of changing look-ahead distance. Through experiment results, it was noted that the lateral errors mean value was within 0.05 m for forward path tracking and 0.06 m for backward path tracking while the heading errors mean value was within 0.5 degree for forward path tracking and 1 degree for backward path tracking. The proposed algorithms were suitable for the differential-drive robot platform for forward and backward path tracking with a reasonable look-ahead distance.