Fault deviation estimation and integral sliding mode control design for Lipschitz nonlinear systems

This paper is concerned with the problems of observer-based sliding mode control and fault estimation for Lipschitz nonlinear systems. The concerned plants are characterized with an actuator fault deviation existing in state dynamics and measured outputs. It represents a more general faulty plant case than those considered in the existing literature. Comparing with existing results on the sliding mode control procedure design, we propose new techniques to overcome the difficulty caused by parametric perturbation and measured noise existing in system output. For precisely estimating the plant states and the faults simultaneously, a novel estimation technique is developed to tackle the influence from the fault deviation. Based on the state estimation, an integral-type sliding mode control scheme by the utilization of an augmented sliding mode observer is presented for the stabilization of the faulty plants. Finally, an electromechanical system is applied to validate the availability and applicability of the presented control methods.