Lei Xiao

Aiming at the vehicle stability control problem under the extreme conditions of the vehicle, the distributed drive electric vehicle (DDEV) is taken as the study object, and the lateral stability control method of the vehicle is designed according to the stable state of the vehicle. Firstly, the side slip angle-side slip angle rate phase portrait is used as the vehicle stability judgment basis and the stability control region is developed. Secondly, different control strategies are formulated according to different vehicle states, and a stability control method relying on the combination of the center yaw moment of the vehicle’s front axle and the center of mass yaw moment is proposed. The controller based on this method has a hierarchical structure, in which the upper controller calculates the additional yaw moment required for the vehicle to maintain stability based on the vehicle state, and the lower controller assigns the desired yaw moment to the optimal drive torque of each wheel. Finally, the joint simulation of MATLAB/Simulink and Carsim shows that the combination of direct yaw moment control (CDYC) method has a strong body attitude correction capability under extreme conditions and can significantly improve the vehicle stability.

A multi-objective intelligent optimization algorithm-based attitude control strategy for magnetorheological semi-active suspension is proposed to address the vehicle attitude imbalance generated during steering and braking. Firstly, the mechanical properties of the magnetorheological damper (MRD) are tested, and the parameters in the hyperbolic tangent model of the magnetorheological damper are identified through experiments. Secondly, a simulation model of the whole vehicle multi-degree-of-freedom vehicle dynamics including magnetorheological damper is established, and the whole-vehicle Linear Quadratic Regulator (LQR) controller is designed. Then, the optimization design model of the joint vehicle controller and vehicle dynamics is established to design the optimization fitness function oriented to the body attitude control performance, and the attitude optimal controller is calculated with the help of multi-objective intelligent optimization algorithm. Simulation results show that the proposed control method is able to improve the body roll angle, body pitch angle, and suspension dynamic deflection well on the basis of ensuring no deterioration in other performance indexes, ensuring good attitude control capability of the vehicle and verifying the feasibility of the control strategy.