Research On Design And Simulation Experimental Evaluation Of Dual-motor Electric Power Steering System For Commercial Vehicle

With the development of science and technology,Electric Power Steering(EPS)System has been gradually applied to the field of small and medium-sized passenger vehicles,and greatly improved the vehicle's steering performance.However,in the field of commercial vehicles with large demand-driven torque,the EPS system has not yet been popularized due to factors such as vehicle voltage.This thesis focuses on the demand for large assistance torque for commercial vehicles,a matched dual-motor electric power steering system and its control strategy were designed.Furthermore,an objective evaluation system for the steering system was proposed.The whole control strategy and objective evaluation system were tested based on co-simulation.The main research work is as follows:1.Based on the theoretical research of EPS and the relevant parameters of commercial vehicle,the overall structure of the dual-motor EPS system is designed,and the key components are selected and matched;the assisting characteristics and control modes of the EPS system are analyzed,and a linear power assisted curves is designed.Current distribution control strategy and fault tolerant control mode for dual-motor EPS system were designed as well.2.On the basis of parameter-oriented modeling vehicle dynamics simulation software TruckSim,a commercial vehicle dynamics model was constructed.The control model of dual-motor EPS system was established in Matlab/Simulink.The dual-motor EPS system and dynamic model of commercial vehicle were verified by simulation.3.An objective evaluation system for EPS was put forward,mainly including transient response characteristics,steering facilitation,steering return,steering sensitivity,extreme condition performance,and driver steering burden evaluation.And the evaluation index and co-simulation model were designed.Simulation experiment was performed with or without EPS,and an objective evaluation of various performances of the EPS was made.The results show that the commercial vehicle EPS designed in this paper is correct and effective,and has good power-assist characteristics,which improves the handling stability of the vehicle and has certain guiding significance for the development and improvement of the actual EPS.