Tracking Control with Prescribed Performance for Nonlinear Systems with Mismatched Disturbances

In this paper, a tracking control scheme is proposed to achieve the prescribed performance for the strict feedback nonlinear systems with mismatched disturbances. The “prescribed performance” is referred that we can preselect convergent performance of the tracking error before the controller design, which can be achieved by transformations of tracking error. Furthermore, a sufficient condition is developed to assure the equivalence of transforming. To achieve the prescribed performance, a novel back-stepping strategy based on the transformed error system is formulated with low complexity. The proposed controller can guarantee that all the system states are globally bounded and converge according to the prescribed performance besides the tracking error. Simulation is performed to verify and clarify the effectiveness of the proposed scheme.