The Power Steering System Developed

As the drive speed increased greatly with the highway booming, the problem of vehicle's high speed stability is becoming more and more serious. Traditional mechanical steering systems can't solve this problem, so power assistant steering systems have been developed. The existent Power Assistant Steering systems are low effective. Instead, the Electric Power Steering (EPS) has effective handling and stability in high speed and some other advantages. It has become a promising way in vehicle electric systems.The research content and conclusion involved in this paper are as follows:The development history of EPS was introduced. The control strategy of EPSwas studied and certain control strategy was adapted after theory of EPS was analyzed deeply. Fuzzy control used in EPS control strategy was studied in details.The whole EPS system including the hardware design and EPS bench experiment environment was developed on the basis of the adapted control strategy.The software to fulfill the control strategy was studied especially. Because it was a real-time control process, the assemble language was adapted. Besides the fulfillment of the main function required in this control strategy, lots of affiliated functions were added. So, the expansibility of the whole system was improved.At last, the experiment results were analyzed and the debug software and hardware environment was introduced. The results showed that control strategy can make EPS work well and that Power assistant control mode and Returnable control mode were fulfilled.Two Innovative points in this paper were presented:1. The design of EPS was determined, and control strategy was developed. Current closed loop control strategy with current sensor was adapted, andfeedback current was acquired with sampling resistance instead of Hall sensor.2. A preliminary study was done on the application of fuzzy control in EPS. Corresponding software was offered to fulfill the control strategy.