Simulation results and practical implementation of a PD-super-twisting second order sliding mode tracking control for a differential wheeled mobile robot

摘要

A robust solution to the trajectory tracking control problem for a differential wheeled mobile robot should deal with the existence of parametric and structural uncertainties, external disturbances, and operation limitations. The first order sliding mode control with a boundary layer is a common and suitable solution that can ensure chattering attenuation but with a poor degree of robustness. Fortunately, higher-order sliding mode control can achieve a greater degree of robustness with the reduction of the chattering phenomenon. Based on this knowledge, a control strategy is proposed using a super-twisting sliding mode control, which enforces a second-order sliding mode, integrated with a proportional plus derivative control to solve the problem of achieving good robustness. This linear control technique plays an important role in increasing the robustness by mitigating the influence of neglected dynamics. Simulation and experimental results are explored to prove the effectiveness of the proposed control strategy.