Fault-tolerant control for in-wheel-motor-driven electric ground vehicles in discrete time

摘要

To achieve good performance, high reliability and easy implementation, a discrete-time fault-tolerant control strategy is presented for in-wheel-motor-driven electric ground vehicles (IWM-EGVs) with active steering systems. Compared with the existing studies that only address linear systems and are mainly based on the method of least squares with persistent excitation conditions, a discrete-time adaptive triple-step controller is proposed in this paper for coordinated lateral and longitudinal control of IWM-EGVs with coupled and nonlinear dynamics considering the adhesion limit characteristics of vehicle tires and the effects of potential faults on the in-wheel motors and the active steering systems. With the proposed algorithm, the loss-of-effectiveness, additive, and stuck-at-fixed-level faults and the total failure of steering systems can be accommodated based on the adaptive update laws and controller reconfiguration in discrete time. The effectiveness of the proposed approach is validated by the simulation results obtained under a high-fidelity veDYNA full-vehicle model with different driving tests and faults. (C) 2018 Elsevier Ltd. All rights reserved.