Observer-based fixed-time adaptive fuzzy control for SbW systems with prescribed performance

Abstract

This paper addresses a tracking control problem for Steer-by-Wire (SbW) systems with unmeasurable states, model uncertainty, and limited communication resources. An interval type-2 fuzzy logic system (IT2 FLS)-based fixed-time state observer are proposed to estimate the unavailable state. Different from the accurate model-based state observers and the observers with some additional assumptions, under the proposed observer, the extra conditions can be removed and the fixed-time convergence of observation error can be guaranteed. To save communication resources of the controller-to-actuator channels and achieve the prescribed tracking performance, an event-triggered prescribed performance control (PPC) scheme is proposed. Compared with these existing PPC methods, the computational complexity is reduced and a new prescribed performance function with fixed-time convergence is suggested to improve the steady-state and transient performance of the closed-loop system. The Zeno behavior of the event-triggered communication can be avoided. Simulations and experiments are carried out to demonstrate the effectiveness and superiority of the proposed control technique.