Sliding Mode Control: Implementation Like PID for Trajectory-Tracking for Mobile Robots

Most of the controllers design are based on a process model. Generally, the processes are nonlinear, of high order and thus the number of tuning parameters for the controller are in proportion to the model order. Mobile robot models are nonlinear and complex, and the use of traditional procedures to design the SMC would result in a really extensive and probably inefficient expression. For that reason, the robot platform will be treated as a black-box, where only the input and output signals are known, and from them a linear low order model obtained. The linear model is used to synthesize the controller. Therefore, this paper proposes a general approach using a linear low order model of the robot for the SMC implementation. The designed controller has tuned parameters based in the use of a PID-like surface, which simplifies the implementation and avoids the use of the complete model of the robot. A robot Pioneer 3DX is used to test the controller's performance when tracking a square trajectory.