Patent ID: 7684912
Filing Date: 2010-03-23
Classification: B62D

Abstract:
1. An electric power steering apparatus comprising: a torque sensor for detecting torque applied to a steering member and outputting a torque signal in accordance with the detected torque; a first output unit for outputting a first control amount in accordance with the outputted torque signal, except in a dead zone thereof; an electric motor driven based on the first control amount for assisting steering; a phase advancing filter for advancing a phase of the torque signal in case that a frequency of the torque signal is higher than a first frequency, and attenuating the torque signal in case that the frequency of the torque signal is lower than a second frequency which is lower than the first frequency; a second output unit for outputting a second control amount in accordance with the torque signal from the phase advancing filter, except in a dead zone thereof; a first gain data output unit for, when the torque signal outputted by the torque sensor is within a predetermined range, outputting gain data in accordance with the torque signal outputted by the torque sensor; a steering angular velocity sensor for detecting and outputting the steering angular velocity of the steering member; a second gain data output unit for, when the steering angular velocity outputted by the steering angular velocity sensor is within a predetermined range, outputting gain data in accordance with the steering angular velocity; an interface for outputting a vehicle speed of a vehicle provided with the electric power steering apparatus; a third gain data output unit for, when the vehicle speed outputted by the interface is equal to or greater than a predetermined value, outputting gain data in accordance with the vehicle speed; a multiplying unit for producing a product formed by multiplying the gain data outputted by the first gain data output unit, the gain data outputted by the second gain data output unit, the gain data outputted by the third gain data output unit, and the second control amount outputted by the second output unit; and an adding unit for adding the product produced by the multiplying unit to the first control amount for updating the first control amount.