Study On Robust Control Strategy For EPS System Based On Handling Stability

Electric power steering (EPS) system, as the key technology of new energyautomotive, has more advantages and developing space than other power steering system.In this thesis, vehicle handling stability is concluded in the indicator system of thecontroller on the basis of the research on the performance of the EPS system. A robustcontroller of the EPS system is designed by the mixed sensitivity algorithm depending onthe requirements of the vehicle handling stability, EPS system performance, and therobustness and stability of the control system.The dynamic model of EPS system,3-DOF model concluding roll angle and lineartire model are established based on the analysis and simplification of the EPS system aswell as the vehicle motion, then a comprehensive control model is builded based on thethe relationship between the model above. On the MATLAB/Simulink simulation platform,the rationality of the comprehensive model is verified with the reference of the nationalstandard GB/T6323.2-94vehicle handling and stability test methods-steering transientresponse test (steering wheel angle step input)’’. Based on the analysis of the performanceof the vehicle handling stability and EPS system and depending on the established linearassistant characters, the requirements of the comprehensive system are quantized and theideal mathematical expressions are acquired.In order to verify the effectiveness of the control algorithm, a compared simulation ofno power steering model and EPS model is performed in the condition of unloading sensornoise and loading sensor noise. The results indicate that the vehicle with EPS robustcontroller not only has the decent road feel and assistant characters, but also has asignificant improvement in the transient response of the roll angle and yaw velocity to thesteering wheel angle step inputting, and the vehicle has good handling stability androbustness restraining the noise interference...