Research of refit technology on electric power steering

CHENG Shou-guo， CHEN Xiao-long
（Department of Mechanical & Electrical Engineering， Jiangyin Polytechnic College， Jiangyin 214405， China）

Abstract： Aiming at resolving the problems of leaking，complicated structure，and not easy to assembling or disassembling on hydraulic power steering（HPS）system，a light vehicle acting was used as prototype vehicle，the electric power steering（EPS）technology was introduced to replacing the HPS. After the analysis of the prototype vehicle，the relationship between the hydraulic power steering system and the electric power steering system was established. The assistance characteristics curve of EPS was designed，and the key parameters of the motor，the gearbox，the ECU and the torque sensor of EPS were defined by references of the assistance characteristics curve of HPS，the analysis and calculation of the ground maximum moment resistance and the biggest assistance torque of HPS. The relations between the assistance curve and the manual torque were tested after the snake-like road experiment on the refitted vehicle with EPS. The results indicate that the EPS system can replace the traditional hydraulic steering system for its smooth operation，realize the of assistance power change by vehicle velocity，good ride comfort and good ride feeling.
Key words： electric power steering（EPS）； automobile； refit； hydraulic power steering（HPS）