Development And Test Verification Of Automotive Electronic Power Assistance Steering System

Electric power steering system(EPS),as a new generation of automotive steering system,is undergoing a rapid development,and gradually occupying the automotive market.At present,research and development of EPS in our country is still in its infancy,the main technology is largely dependent on foreign parts manufacturers,and domestic R & D companies have been squeezed by similar foreign manufacturers.In order to reduce the gap to make our country become independent in research and development,high quality EPS system were developed and achieved a high level comparing with the foreign products,in addition,the steering testbed and driving simulator were developed and improved for the test validation of EPS controller.At the end,a series of standardized experiments were conducted.Experimental results showed that the improved EPS controller can make the vehicle achieve a better steering performance.Firstly,the EPS system currently in the specific circumstances of domestic development was described,advantages of the EPS system,the classification and system are described,then the EPS simulation model was built for the basic introduction,which laid the foundation for the EPS system development.Secondly,specific analysis of the upper control strategy of development of EPS system was made,including: basic assist control,torque differential control,motor compensation control,return control of permanent magnet synchronous motor vector control,and focused on the torque differential control,compensation of motor control and return control optimization.The control algorithm of EPS system was analyzed and improved,so as to solve the optimization problem of EPS controller fundamentally.Then,in order to validate the improved and optimized EPS system experimentally,a high precision,strong versatility of driving simulator and control hardware of the loop test bench was built according to the domestic electric control to hardware in the loop test bench for some of the deficiencies by using some foreign advanced technology of simulation system scheme and the build process were described in detail,which provide strong experimental platform of hardware in loop experiment and algorithm improvement for the next step.Finally,a series of standardized tests on the developed EPS controller was carried out,including the steady state steering performance test,the steering step test,the compensation test,the steering return test and the in-situ steering test.Through the analysis and comparison of the experimental results,the conclusion is drawn that the vehicle with improved optimized EPS controller can obtain better steering performance.