The Research Of Torque Compensation Of Electric Power-assisted Steeirng

According the emergence of Electric power steering (EPS), on the one hand, weget a technical way of being more energy and more environmental protection for car;On the other hand, it improves the low speed cars’ flexibility and the high speed cars’stability. With the improvement of EPS control, the damping control and thereturn-to-center control, in order to make the drivers get a better driving, this paper isin view of the power deviation of EPS under the lateral winds, the accidented groundor other outside interferences（1）Firstly,we set up a dynamic model of EPS with the ground and lateral windsinfluences. According to the dynamic model, use of the Simulink toolbox of Matlab tocomplete the establishment of the emulational model of EPS.（2）Through the emulational model can get the torque values of the output shaft ofEPS in the external excitation, furthermore we can obtain the torque values, which areunder the external disturbance,through the torque sensor.（3）Then use the torque values as the training sample of the support vectormachine(SVM).Finally we use Matlab toolbox to complete the SVM data classificationand obtain its optimal boundary surface. Through the standard of the optimal boundary,we can predict the test sample for judging that whether the torque values have theoutside interferences which come from the torque sensor’s outputs.（4）In consequence, under the different conditions, we have the steering wheeltorque values and the speed as inputs, then use of Matlab fuzzy logic toolbox toestablish a fuzzy controller for getting the EPS characteristics curve graph. We can gettwo kinds of EPS dynamical characteristics curve graph that one is having interference,the other one isn’t having interference, and then we get different assist power current values. The difference is the current value that we want to compensate the outsideinterference.