Unifying performance specifications in tracking control of MIMO nonlinear systems with actuation faults

Abstract

Guaranteeing prescribed performance is critical to maintaining system efficiency and reliability. The state-of-the-art approaches achieve different performance specifications with different control structures and settings. In this paper, we propose a novel control methodology to uniformly address the prescribed performance problem for uncertain multiple-input multiple-output (MIMO) nonlinear systems in the presence of actuator faults. By constructing a non-monotonic function transformation and an asymmetric barrier function, we recast the underlying problem into one that only needs for simple selection of certain design parameters. With such a treatment, different performance behaviors can be achieved under a single (unified) control framework without the requirement for alternating the control structure, making the design more user-friendly and implementation less demanding. Furthermore, by embedding the available information on the state-dependent diagonal matrix into the filtered-error-like design procedure, the obstacle of ensuring the controllability of the closed-loop system, caused by the actuator faults and performance behaviors, is circumvented. Both theoretical analysis and numerical simulation demonstrate the effectiveness and benefits of the proposed method.