A Dynamics Research Of The Electric Hydraulic Power Steering System And The Controller Design

The steering system of automotive is one of the important factors that impactthe handing and stability of vehicle. It plays an important role at the aspects ofensure the driving safety of vehicle, protect the driver and improve the driver’sworking condition. In order to satisfy the increasing requirements of the safety,comfort and handing stability of the car by the people, it is significant to focus onthe dynamic analysis and the design of the control strategy. Research on the electrichydraulic power steering system has been done in this paper, which is still in theearly stage in china, the main work content as follows:First of all, a detailed introduction of the electric hydraulic power steeringsystem has been done, especially the structure and working principle of the keycomponents, such as the control valve, the electric pump assembly and the sensoretc.Then, the mathematical model of electric hydraulic power steering systemparts have been built, including the motor model, the mechanical subsystem model,the hydraulic subsystem model and the three degrees of freedom vehicle model.The steering characteristics and sinusoidal input response of system have beensimulated by Matlab/Simulink based on the mathematical model.Furthermore, based on the control theory of electric hydraulic power steeringsystem has been deeply study and practice, and the PID control algorithm inthe application of brushless dc machine has been researched. The steeringcharacteristic curve and speed-current double closed loop control system of motorhave been designed in this paper. Also, freescale, a popular microcontroller in thefield of the car has been used. At the same time, the corresponding hardware circuithas been designed in order to realize its functions.At last, a testing platform of electric hydraulic power steering system has beenbuilt based on LabVIEW, and the comprehensive test of the motor also has beendone. This paper provides the basis of theory and engineering in the field ofdevelopment and optimization design of electric hydraulic power steering system inchina, in order to break up the monopoly of the automobile core components byforeign.