ELECTRONIC POWER STEERING APPARATUS AND METHOD FOR DECREASING TORQUE RISE OF ELECTRONIC POWER STEERING APPARATUS IN LOW TEMPERATURE CONDITIONS

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to an electric steering system, and more particularly, to a technique for reducing a torque increase due to an increase in friction force in a low temperature state of an electric steering system. According to the embodiments, the viscous friction compensation current is calculated by using the viscous gain and the steering angle velocity determined according to the damping coefficient estimated from the sensed temperature in the low temperature state of the electric power steering apparatus, and using the sensed temperature and the steering angle accumulation amount The Coulomb friction compensation current is calculated, and the calculated viscous friction compensation current and Coulomb friction compensation current are supplied to the motor in addition to the driving current of the motor so that the driver can feel the same steering feeling at room temperature even in a low temperature condition.