Abstract
Vehicle stability control, as an important part of active safety technology, has a critical impact on improving the overall safety of vehicles. The purpose of this paper is to discuss an integrated DYC (Direct Yaw Moment Control) and AFS (Active Front Steering) system. A fault-tolerant disturbance adaptive nonsingular fast terminal sliding mode control (FDASMC) is proposed with the aim of solving the problem of maintaining the stability of the system and improving the tracking performance of the system in a finite period of time with external perturbations and actuator failures. Firstly a nonlinear disturbance observer (NDOB) based on the dynamics model of four-wheel independently-actuated electric vehicle(4WIDEV) is constructed with the aim of reducing the negative effects of system uncertainty and external disturbances on the controller accuracy. Secondly to improve the convergence performance of the traditional sliding mode control, this paper introduces a nonlinear function into the sliding mode switching function to ensure that the system accurately tracks the desired state in finite time. In addition, a non-singular fast terminal sliding mode controller is further designed to prevent singular phenomena, and a dynamic gain observer is designed on this to cope with the system instability due to actuator failure. Finally, through theoretical analysis and simulation verification, this paper demonstrates that the proposed integrated control system is not only able to achieve accurate tracking of the desired state within a limited time, but also has excellent tracking accuracy, which significantly improves the vehicle's maneuvering stability.