Implementation and Control Logic Design of Intelligent Electric Power Steering System

In this paper, an intelligent electric power steering system is proposed to replace a traditional hydraulic power steering system and implemented in a real light hybrid electric vehicle. An intelligent fuzzy control algorithm is applied to yield basic assist logic, return compensation logic, damping compensation logic, and inertia compensation logic in an assist steering system. According to steering wheel angle and vehicle speed, the proposed fuzzy inference logic can provide needed assist motor current. Under experts’ knowledge of fuzzy control, the electric power steering system can satisfy smooth driving. In addition, four driving modes are designed to complete the control strategy. Different driving modes have corresponding fuzzy inference strategies to complete the assist and compensation logic. Finally, the intelligent electric power steering system with a new 12V/500W EPS motor is applied in a real light hybrid electric vehicle. Experimental results demonstrate that the proposed method is reasonable and feasible.