The Research On Optimized Torque Distribution Strategy For Distributed Drive Electric Vehicle

In recent years,the rapid development of the automobile industry has facilitated people to travel,and it has also brought a large burden on the ecological environment.Due to global warming issues and oil resource issues,electric vehicles have become the most ideal development direction for the future automotive industry.The completely different driving modes of distributed-driven electric vehicles and traditional vehicles have gradually become the focus of research.The advantages of independent distribution of each wheel and independent control of torque provide a huge research space for its optimal torque distribution.This paper makes an in-depth study on the torque optimization distribution strategy of distributed-driven electric vehicles,and improves the performance of all aspects of the vehicle by optimizing torque distribution,and the main work is as follows:Firstly,build the joint simulation platform of Carsim and Simulink.Carsim software with accurate vehicle modeling is selected to establish the vehicle model.Simultaneously,the motor is modeled in Simulink software,and the input and output interfaces of the Carsim vehicle model are reasonably configured to complete the establishment of the joint platform.The reliability of the platform is verified through the standard dual-shift line operating conditions,which lays the foundation for the establishment and verification of subsequent torque distribution strategies.Secondly,calculate the additional yaw moment based on the vehicle’s stability requirements,and use it as the upper constraint of torque distribution to ensure vehicle stability.The structure of the vehicle stability control system is mainly divided into two layers.In the upper layer of the stability controller,the sliding mode control algorithm is used to track the vehicle model,and the appropriate sliding mode surface and approach rate are selected to calculate the additional yaw moment.Value,as a foundation for the establishment of the lower torque optimization distribution layer later.Thirdly,under the constraint condition of additional yaw moment calculated by the upper controller,the torque is optimized to meet the vehicle stability and take into account certain economy.Construct a comprehensive optimization objective function with stability as the main consideration and economy.By tracking and judging the parameters of the vehicle’s stability state,the yaw angular velocity and the center-of-mass lateral angle,the fuzzy controller is used to determine each objective function in the comprehensive optimization objective function’s weight.When the constraints of each actuator are satisfied,the weighted least squares method is used to optimize the torque distribution,and the effective set solution is used to solve it and improve it.Finally,the torque optimization distribution strategy is simulated and analyzed on the Carsim-Simulink joint simulation platform.The low-speed angular jump mode and the high-speed double-shift line mode are selected to simulate the vehicle stability.The results show that the vehicle’s center-of-mass lateral angle and yaw rate have obvious corrections under the vehicle stability control system.The simulation and analysis of the optimal torque distribution strategy under high-speed double-shifting working conditions show that the vehicle stability and economy have been improved after the optimal torque distribution.