20 / 2016-08-02 20:15:48

Research of Double Closed Loop PID Control Strategy of Road Feeling Motor

Steer-By-Wire,Road Feeling Motor,double closed loop,platform test

One apparent advantage of Steer-By-Wire (SBW) system is that its road feeling characteristic can be designed freely. Whether the road feeling characteristic is able to be formed effectively depends on the control effect of road feeling motor (RFM). When a RFM is working under the condition of plugging around or reversing around, the back electromotive force (BEMF) will occur in the circuit which will interrupt the RFM's control ability. Thus in this paper, a double closed loop (DCL) PID control strategy based on torque and current was designed in order to improve the RFM's control ability. Then, transfer functions of the RFM and the steering wheel system (SWS) were obtained, a simulation model was established via Simulink, and a road feeling simulation system test platform was built so as to verify the effectiveness of the control strategy. The results of step response tests and sine followed tests show that: the DCL PID control strategy can effectively eliminate the control negative effects caused by BEMF of the RFM, which make the output torque error be in the range of ±0.5N•m, which can meet the control requirement of RFM.