A Study of Assist Control in Electric Power Steering - Driving Pattern Rule-Based Control - 2000-05-0241

This paper describes a rule-based electric power steering control system wherein driving patterns are judged based on input torque change ratio in addition to steering angle and input torque and assist characteristics changed accordingly to achieve the most appropriate steering feeling. We installed a conventionally controlled system and one with the proposed control in a test vehicle and compared driving effort by studying electromyogram measurements. It has been shown by the results that driver effort has been reduced and steering wheel turnability has been improved without sacrificing conventional steering feeling. The proposed control is a first step toward improving steering feeling and achieving ideal assist control in electric power steering.