EPS Control Strategy And Experimental Research With HIL Method

The increasing demand for comfort, safety and driving feedback in modern vehicles puts forward a higher requirements for the control technology in vehicle steering system. The Electric Power Steering system, known as the EPS, have been widely used with its advantages of energy-saving, rapid response capability and diverse integrated functionality. The study on the control strategy and testing platform have great significance to the development of the auto components industry, especially in the status of the backward technology in control strategy and the test methods in the domestic nowdays.The key technologies and future research focus in EPS and it’s testing platform were analyzed, the structure and composition were introduced, and the signal mechanism of EPS were discussed emphatically. The modles of the whole vehicle and the EPS which including the torque sensor, were build basing on the MATLAB/Simulink environment The dynamics of the steering system was analyzed in connection with the impact of the motor introduction, and the impact of the working signals to the EPS’performance were analyzed emphatically. Basing on the analysis results, a fault control strategy for multi-signal failure conditions, aassist control strategy of complex of the poly line and curve, a returnability strategy which basing on the compensation torque curve and a compensation control for inertia and damping were proposed and simulated through the MATLAB/Simulink.Hereafter, the testing platform which is compatible with various structures and signal environment was build on the NI PXI Real-Time systems and the dynamics simulation software of Tessis_VeDYNA. Some HIL solutions for fault-tolerant performance testing, steering portability testing, retumability testing and straight running stability testing were designed. The integrat test functions and the control programs for the hardware of programmable control DC power supply, load mechanism and signal processing system were designed and debuged in the environment of LabVIEW in accordance with the test scheme. Finally, the fault-tolerant performance, the steering portability, the returnability and the straight running stability were researched through the HIL testing platform. The test results shows the control effects of the designed strategies, and reflects the effectiveness of the test functions of the EPS testing platform.