Research On Acceleration Slip Regulation Control Strategy Of Dual-motor Four-wheel Drive Electric Vehicle

In the process of all industrial development,development and protect the environmental are always contradictory and unified.Throughout the history of automobile development,the fuel and Gas discharged from pipeline of traditional cars undoubtedly reflect the mutual exclusion between traditional cars and protect the environmental,The emergence of energy-saving and pollution-free electric vehicles,which enables the automobile industry and environmental protection to develop in a mutually promoting way.A new type of dual-motor electric vehicle combines the advantages of centralized control electric vehicle and distributed electric vehicle with its simple structure,and has become the research center of researcher and worldwide enterprises.In this paper,the dual-motor electric vehicle is taken as the study target,the key of this paper is the longitudinal instability and lateral instability of the car during running.The designed control policy has certain academic meaning for raising the stability and dynamics performance of the dualmotor electric vehicle.Aim at the problem that the wheels are easy to slip during driving,the pavement identification algorithm is established to distinguish the optimum slip rate of the current road;Radial basis function PID control algorithm can control the wheel slip rate by setting various inputs and outputs.Design the anti-rotation control policy of the whole vehicle running,select the main control motor according to the principle of high selection,and supervise and control the other axis electrical machinery with the torque compensation policy.Through simulation analysis on different road surfaces,the deviation between the slip ratio of each wheel and the optimum slip ratio of the road where the wheels are located is less than 0.02,and the vehicle acceleration capability is improved by about 25%.Aim at the lateral instability in the process of vehicle steering,a layered control strategy for handling stability is designed by analyzing the reasons of vehicle side direction loss of stability and vehicle steering characteristics.The upper tracking layer firstly define the goal of control as yaw rate,and calculates the additional yaw moment to solve the instability by establishing a two-degree-of-freedom reference model of yaw rate and comparing it with the yaw rate in actual vehicles.The wheel hydraulic simulation model is established,the additional yaw moment is converted into the braking moment applied to the wheel by hydraulic differential braking distribution,and the wheel applying the braking moment is judged according to the current steering characteristics of the vehicle.It can control the deviation between the actual yaw rate and the target value to be less than 16%of the target value when the vehicle is unstable.In order to ensure the vehicle’s longitudinal and lateral stability as well as the vehicle’s dynamic performance in the process of accelerating steering,the coordinated control of driving anti-rotation control system and steering stability control system is designed.This paper analyzes the different requirements of vehicle for dynamic performance and stability under different vehicle speeds,sets the threshold value of vehicle speed,and gives priority to ensuring vehicle dynamic performance at low speed and vehicle stability at high speed.According to these requirements,the opening conditions of the control system at different vehicle speeds are designed.The simulation results of accelerating steering under two different working conditions show that the deviation between the wheel slip rate and the optimal road slip rate can be controlled below 0.02 under both working conditions.The deviation between the actual yaw rate and the target value is controlled to be less than 16%of the target value when the vehicle is laterally unstable.