Precise trajectory tracking of mecanum-wheeled omnidirectional mobile robots via a novel fixed-time sliding mode control approach

This paper proposes a novel fixed-time sliding mode control approach for trajectory-tracking tasks of a mecanum-wheeled omnidirectional mobile robot. First, the idea of two-phase attractors is introduced into the domain of sliding mode control, and a new fixed-time sliding surface is proposed. Then, according to this sliding surface, a new type of nonsingular fast terminal sliding mode control algorithm is designed for the omnidirectional mobile robot, which can realize a fast fixed-time convergence property. The stability of the control system is proven scrupulously, and a guideline for control-parameter tuning is expounded. Finally, experiments are implemented to test the trajectory-tracking performance of the robot. Experimental results demonstrate the superiority of the proposed sliding surface and the corresponding control scheme in comparison with benchmark controllers.