Nonlinear Moving Horizon Longitudinal Control for Electric Vehicles Based on Tire Force Prediction in Snow Environment

This paper uses a nonlinear longitudinal control method for distributed drive electric vehicles(DDEV) to solve the safety problem of DDEV when driving on snow-covered road. Therefore, an optimal slip control scheme based on tire force prediction is proposed. First, use the Burckhardt tire model to draw mu-kappa curve, use the magic formula to draw F-x-kappa curve, get the maximum longitudinal tire force that can be provided under different road types ahead. Then calculate the tire force required for stable driving of the vehicle, predict the state of the vehicle in advance. This paper aims at the situation that tire force is not saturated during the driving process of the vehicle, the lower layer uses the nonlinear model predictive control(NMPC)algorithm to design the optimal slip controller. The main purpose is to control the torque of the four wheels simultaneously so that the slip rate can follow the optimal value, thereby effectively preventing the wheels from over-slipping during driving or locking during braking, enhancing the maneuverability and stability of the vehicle in extreme environments. Finally, the dynamic simulation software CarSim is used for simulation verification under various working conditions. The results show that the controller designed in this paper can effectively track the optimal slip value of each wheel, play a driving assistance function, and realize the multi-objective requirements of "safety-power-comfort".