Discrete Fast Terminal Sliding Mode Control for Yaw Stability and Energy-Saving of FWID-EVs With Input Delay and Lumped Disturbances

This work focuses on the yaw stability and energy-saving for the four-wheel-independent-drive electric vehicle (FWID-EV) with the constrained active front steering (AFS) and torque vectoring control (TVC) subject to input delay and lumped disturbances. First, a coordination control supervisor is developed to solve the conflicts between the AFS and the TVC, in which an identification model for the boundary of instability is established based on the phase plane of vehicle sideslip angle and yaw rate. Second, an input-delay compensator is developed to reduce the negative effect of input delay from controller area network bus. Third, a discrete fast terminal sliding mode and active disturbance rejection control strategy is proposed to guarantee yaw stability of the FWID-EV by overcoming the lumped disturbances. Both the software-in-the-loop and the hardware-in-the-loop tests are performed to verify the effectiveness and practicability of the proposed method, respectively.