Target-tracking Controller Design for Differential Drive Mobile Robots with Limited Actuator Capacity

The design of a target-tracking controller for experimental differential drive mobile robots is presented, in addition to a corresponding method for tuning its parameters. The target tracking controller, whose design connects experimental algorithms with wheel hardware interfaces, guides the robot to its goal without being affected by the actuator's minimum speed limit. When the robot is far away from its goal, the controller will adjust the robot's orientation to the direction of the goal while shortening the distance between the robot and the goal. Without increasing the complexity of the algorithm, when the robot increases its proximity to its target, the control strategy is switched to prioritize robot orientation and its travel speed decreases along with its distance to the target. Simulation and experimental results on the KheperaⅢ robot show that the robot follows a smooth trajectory, with its traveling speed transitioning from fast to slow, and ultimately reached its goal at approximately the minimum speed of the actuator.