Research On Toroue Coordination Control Of Four-wheel Independent Drive Electric Vehicle

Due to environmental pollution and energy consumption caused by traditional internal combustion vehicles,electric vehicles have great potential for development,and four-wheel-drive electric vehicles with simple structure and high integration have also received attention.Based on its characteristics,this paper proposes a four-wheel independent drive torque coordination system based on vehicle stability,and builds a vehicle control simulation platform and a prototype test platform to verify the feasibility of the system.(1)According to the needs of this paper,aiming at the stability of vehicle driving,the vehicle kinematics model,tire model and ideal linear two-degree-of-freedom model of the four-wheel hub-driven electric vehicle are built for the subsequent vehicle control system.The construction provides a theoretical basis.(2)Set up a four-wheel drive electric vehicle drive hub motor control system to provide power source for electric vehicles.The brushless DC motor model was used as the driving hub motor.The PID-based speed and current double-loop control of the hub motor control system was established in Simulink and simulated.The simulation results show that the stability and operability of the hub motor drive can be improved by using this control strategy.(3)It is analyzed that the steering stability of the vehicle is affected by the yaw angular velocity and the centroid side declination parameters.A torque coordination control strategy based on vehicle stability for the four-wheel hub driven electric vehicle is proposed to realize the coordinated control of the steering and drive system.The system adopts a control layer design layer and a yaw moment to formulate a layered control strategy in which the layer has been controlled.In the target design layer,the stability and control target yaw rate and the centroid side angle are compared with the actual value to obtain the corresponding error;in the yaw moment setting layer,the yaw moment direct control strategy is used to establish the fuzzy PID based The algorithm's yaw moment controller;in the control distribution layer,a four-wheel torque distribution controller based on vehicle stability is designed.Finally,a vehicle simulation model is established in CarSim,and a fuzzy PID-based yaw moment controller and an ideal two-degree-of-freedom model are built in Simulink.CarSim and Simulink are co-simulated to build a vehicle-based stability.The model of torque coordination control system shows that the proposed control method effectively meets the requirements of vehicle stability control(VSC).(4)Based on the STM32 development board,the build a four-wheel hub electric vehicle prototype test platform.The program design and prototype test were carried out in the Keilu Vision5 software development environment to verify the feasibility of the stability-based vehicle torque coordination control system.