Practical tracking control of perturbed uncertain nonaffine systems with full state constraints

In this paper, we study the practical tracking control problem for a class of pure-feedback systems subject to full states asymmetric and time-varying constraints, non-vanishing uncertainties and external disturbances. A new robust control scheme is proposed to deal with state constraints. Unlike some existing results for practical tracking control, the proposed method does not involve any switching and is able to deal with asymmetric and time varying state constraints without the need for feasibility conditions. Furthermore, with proper choice of scaling function, three different tracking control results (i.e., ultimately uniformly bounded tracking, practical tracking and asymptotic tracking) can be achieved. Simulation verification further confirms the effectiveness of the proposed approach.