Composite observer-based integral sliding mode dynamical tracking control for nonlinear systems subject to actuator faults and mismatched disturbances

• Main Authors: Bei Liu, Yang Yi, Hong Shen, Chengbo Niu
• Format: Article
• Language: English
• Published: SAGE Publishing 2020-08-01
• Series: Measurement + Control
• Online Access: https://doi.org/10.1177/0020294020923077

This brief proposes a novel composite observer-based integral sliding mode tracking control algorithm for a class of nonlinear systems affected by both actuator faults and mismatched disturbances. First, different types of observers, including the extended state observer, the fault diagnosis observer, and the disturbance observer, are integrated to estimate the unknown system state, actuator faults, and mismatched disturbances timely. Then, in accordance with the estimation information, the integral sliding surface and the integral sliding mode controller are proposed, which can tolerate the actuator faults and reject the mismatched disturbances. Meanwhile, the state trajectories can be driven into the specified sliding surface in a finite time. Furthermore, not only the stability, but the favorable dynamical tracking and the output constraints of closed-loop augmented systems can be guaranteed. Finally, the validities of the proposed algorithm are embodied by the simulation results of typical A4D systems.