Output tracking control of strict‐feedback non‐linear systems under asymmetrically bilateral and time‐varying full‐state constraints

Abstract

The state feedback output tracking control problem is investigated for a class of uncertain non-linear strict-feedback system subject to asymmetrically bilateral and time-varying full-state constraints. Non-linear mapping is employed to deal with full-state constraints and the system is transformed into an uncertain pure-feedback system. For the transformed system, an approximation-free backstepping control scheme is proposed by using performance function rather than employing any estimator. It is shown that the proposed control strategy can guarantee that all signals in the closed-loop system are bounded and the tracking errors can be made arbitrarily small by choosing proper control gains. Meanwhile, the states are set within the asymmetrically bilateral and time-varying full-state constraints. At last, two simulation examples are obtained to demonstrate the feasibility and effectiveness of the proposed control algorithm wherein the practical system for metro is considered.