A DYC system for 4WID Electric Vehicles via Fuzzy-Nonsingular Fast Terminal Sliding Mode Control

In this paper, we introduce a novel Direct Yaw Moment Control (DYC) system designed to bolster the stability of four-wheel independent drive (4WID) electric vehicles in diverse extreme driving conditions. Our proposed system is developed based on the design of Non-singular Fast Terminal Sliding Mode Control (NFTSMC) methods to calculate two optimal additional yaw moments, each targeting specific control objectives: the desired yaw rate and the desired sideslip angle. These calculated values are then intelligently weighted in real time using a Fuzzy Logic system to determine the final additional yaw moment applied to the vehicle. The stability of the NFTSMC methods is rigorously ensured through the Lyapunov theory. Simulation results underscore the efficacy of our proposed DYC system, particularly in navigating through extreme driving scenarios. Comparisons with no control and fixed weight-based SMC strategies demonstrated significant improvements in both yaw rate and sideslip angle tracking performance. The proposed method not only amplifies control effectiveness, ensuring swift convergence and high precision, but also substantially mitigates chattering phenomena, as evidenced by yaw moment and torque observations.