Simulation Research On The Stability Of Four-wheel Drive Of Electric Vehicle In-wheel Motor

New energy vehicles have outstanding environmental protection advantages and are the mainstream of urban vehicle development today and in the future.With the application of highquality servo direct-drive motors,pure electric vehicles powered by in-wheel motors can greatly reduce structural costs and self-weight,achieve excellent cost performance,and therefore have broad development prospects.Develop an optimized four-wheel drive control strategy for the target vehicle type,which can effectively improve the handling stability and ensure the driving efficiency and driving safety and comfort.In-depth study of the design characteristics and structural parameters of the target vehicle,follow the vehicle dynamics theory and related performance parameter requirements,establish a mathematical model of the target vehicle and a simplified two-degree-of-freedom model;take the vehicle body yaw rate and the center of mass side slip angle as the control objectives Develop a multi-objective control strategy for the drive system with additional yaw torque and wheel slip rate as the main control variables;adopt a hierarchical structure to design the wheel hub four-wheel drive combination controller,where the upper controller is mainly used for the analysis of the collected signals,Processing,the lower controller is used to optimize the processing results of the upper controller,and feedback the implementation.According to the structural parameters of the target vehicle model,the rationality of the technical parameter configuration of the prototype wheel hub motor is analyzed,and necessary parameter corrections are required according to the optimized control strategy.Build a simulation model of the target vehicle in the Adams/Car software environment,choose to configure a compatible control communication interface;build a servo motor model with fuzzy PID control in the Matlab/Simulink software,and verify the matching status of the motor parameters according to the actual configuration of the target vehicle;Import the entire vehicle model in Adams/Car into the simulation platform,run under the set boundary conditions,and verify the rationality of the built model through data analysis.Determine different roads and typical driving conditions,conduct joint simulation tests on the design of the in-wheel motor four-wheel drive control system,analyze and process the test parameters,and further optimize the control algorithm and control strategy.The experimental results show that compared with the prototype car,the optimized fourwheel drive control system of the wheel hub runs stably,the technical parameters of the modified wheel hub motor are reasonable,and it has better robustness under most working conditions.Under high-adhesion road conditions,through single-line-shifting simulation tests,the results show that the control effect of the yaw rate and the side slip angle of the center of mass are good,which are reduced by 70% and 48% respectively compared with the prototype.