关键词: 智能车辆, 四轮独立驱动, 轨迹跟踪, 模型预测控制, 滑模控制

Abstract: Aiming at the problems of low precision of vehicle trajectory tracking and easy to be destabilized under the hazardous working conditions such as high speed driving,low adhesion road surface and large curvature conditions, taking the four-wheel independent drive intelligent vehicle as the research object,a trajectory tracking control strategy considering curvature adaptation and stability was proposed. Firstly,the vehicle traveling speed was calculated in real time according to the road curvature,and the model predictive control algorithm was used to solve the front wheel angle to track the desired path. Then,an additional transverse moment controller was designed based on integral sliding mode control,which used hyperbolic tangent function to reduce the system jitter and assigns moments according to the front and rear axle loads of the vehicle. The control objective was to track the desired trajectory more accurately and stably taking into account the control actuator constraints and vehicle stability constraints; finally, simulation experiments were conducted under double-shift line condition and large curvature condition,and the results show that the designed control strategy can effectively improve the trajectory tracking accuracy,reduce the peak center-of-mass lateral deflection angle and the peak swing angular velocity,and ensure the swing stability and ride comfort of the vehicle.

Key words: intelligent vehicle, Four-Wheel Independently Driven(4WID), trajectory tracking, model predictive control, sliding mode control