SDF‐based tracking control for state‐constrained nonholonomic systems with disturbances via relay switching control: Theory and experiment

Summary This article investigates the tracking control problem for a kind of chained‐form nonholonomic systems in the presence of unknown time‐varying disturbances and full‐state constraints. First, a finite‐time tracking controller is constructed to drive the action of relay switching, which converts the whole control system into two design stages. In order to handle with the predefined asymmetric state constraints, the original tracking error system is turned into an unconstrained system on the basis of state‐dependent function (SDF) function transformations. In this framework, an adaptive tracking control strategy is proposed by means of backstepping and dynamic surface control. Correspondingly, another tracking control law is also constructed to assure the stability of the tracking error system before the action of switching. The theoretical analysis of stability indicates that the proposed tracking control scheme can guarantee that the output state tracking errors converge to zero and the desired state constraints are not violated. At the same time, all the closed‐loop system signals maintain bounded in entire control process. Finally, the validity of the presented tracking control algorithm is demonstrated by simulation and experiment results.