Yaw Stability Control of Distributed Drive Electric Vehicle Based on Torque Optimal Distribution in Ice and Snow Environment

Abstract

In winter, China has a wide range and a long time of snow. The types of roads encountered by vehicles in a snow and ice environment are complex and changeable. At the same time, reducing the road adhesion coefficient will make it easier for the tire force to reach the saturation state, resulting in the decline of vehicle braking performance and handling performance, which poses a severe threat to driving safety. This paper establishes an integrated vehicle dynamics model with four-wheel torque as control input and yaw rate, sideslip angle, and four-wheel speed as output. Considering the yaw stability of the vehicle body and the tracking ability of the wheel slip ratio, the nonlinear model predictive control (NMPC) is used to optimize the wheel torque and improve the driving stability of the vehicle under extreme conditions. Also, the wheel slip rate remains stable, establishes the torque centralized rolling optimization problem, and determines the four-wheel torque. Off-line simulation shows that the control method is auxiliary in driving low road adhesion caused by ice and snow, ensuring the vehicles' safe and stable driving and reducing the probability of traffic accidents.