A Direct Yaw Moment Control Framework Through Robust T-S Fuzzy Approach Considering Vehicle Stability Margin

The direct yaw moment control system of distributed drive electric vehicles provides a flexible control scheme to enhance the vehicle stability through four independently driven in-wheel motors. However, the vehicle nonlinearities may lead to the invalidation of control. To this end, a Takagi-Sugeno (T-S) fuzzy-based robust H-8 control method is proposed to ensure the vehicle per-formance while addressing the nonlinear challenge. First, thanks to the T-S fuzzy modeling technology, the tire non-linear characteristics are described by fuzzy rules, based on which the vehicle lateral dynamics model is established. Next, the safety region represented by the tire slip angles phase plane is presented to evaluate the vehicle stability performance. Considering the control priority of vehicle handling performance and stability control with different stability margins, a multiobjective optimization function is transformed into a standard robust performance optimization problem with dynamic weight coefficients. A T-S fuzzy-based robust H-8 state feedback controller is then designed to ensure the system stability and H-8 performance. Finally, the hardware-in-the-loop tests are conducted to validate the proposed controller. Comparative results show the effec-tiveness to improve the vehicle handling performance while ensuring the stability.