Patent ID: 6445987
Filing Date: 2002-09-03
Classification: B62D

Abstract:
An electric power steering controller for a vehicle to assist steering torque of a driver applied to a steering wheel, comprising:a motor for generating an assistant torque to assist steering torque of a driver steering torque detecting means for detecting the steering torque of a driver, steering angle detecting means for detecting a steering angle of the steering wheel, first reaction torque estimating means for estimating a first road surface reaction torque using the steering torque detected by said steering torque detecting means, second reaction torque estimating means for estimating a second road surface reaction torque using the steering angle detected by said steering angle detecting means, and return torque compensating means for computing a first auxiliary return torque signal to control the assistant torque of said motor, depending on the first road surface reaction torque estimated by said first reaction torque estimating means, and for computing a second auxiliary return torque signal to control the assistant torque of said motor, depending on the second road surface reaction torque estimated by said second reaction torque estimating means, wherein said return torque compensating means controls the assistant torque of said motor in direction to return the steering wheel to an original position by using both of the first and said second auxiliary return torque signals.