Passive actuator fault tolerant control for a class of MIMO nonlinear systems with uncertainties

TLDR

Fault‑tolerant control of affine MIMO nonlinear systems has received little attention compared to other nonlinear system classes. This paper proposes an adaptive passive fault‑tolerant control method for actuator faults in affine MIMO nonlinear systems with uncertainties using sliding‑mode control. The controller models actuator faults as a multiplicative loss factor, assumes a known maximum loss level, adapts without prior uncertainty bounds, and guarantees closed‑loop stability via Lyapunov analysis. Simulation on a two‑degree‑of‑freedom helicopter and a two‑link robot manipulator shows the controller performs satisfactorily.

Abstract

Fault tolerant control of affine class of multi-input multi-output (MIMO) nonlinear systems has not received considerable attention of researchers compared to other class of nonlinear systems. Therefore, this paper proposes an adaptive passive fault tolerant control method for actuator faults of affine class of MIMO nonlinear systems with uncertainties using sliding mode control . The actuator fault is represented by a multiplicative factor of the control signal which reflects the loss of actuator effectiveness. The design of the controller is based on the assumption that the maximum loss level of the actuator effectiveness is known. Furthermore, since the proposed controller is adaptive, it does not require any a-priori knowledge of the uncertainty bounds. The closed-loop stability conditions of the controller are derived based on Lyapunov theory. The effectiveness of the proposed controller is demonstrated considering two examples: a two degree of freedom helicopter and a two-link robot manipulator and has been found to be satisfactory.