Almost disturbance decoupling of nonlinear systems with mismatch uncertainties via feedback linearization approach and fuzzy logic control

Abstract

This paper first studies the output tracking and almost disturbance decoupling problem of nonlinear control systems with mismatch uncertainties based on the feedback linearization approach and fuzzy logic control. The main contribution of this study is to construct a composite controller, under appropriate conditions, such that the resulting closed-loop system is valid for any initial condition and bounded tracking signal with the following characteristics: input-to-state stability with respect to disturbance inputs and almost disturbance decoupling, i.e., the influence of disturbances on the $L_2 $ norm of the output tracking error can be arbitrarily attenuated by increasing some adjustable parameters. One example, which cannot be solved by previous papers on the almost disturbance decoupling problem, is proposed in this paper to exploit the fact that the tracking and the almost disturbance decoupling performances are easily achieved by the proposed approach. In order to demonstrate the practical applicability, this paper has investigated an inverted pendulum control system.