Honda Motor Co., Ltd.

Kazushige Sugamata

Yasuo Shimizu

Shigeru Yamawaki

Yoshihiro Oniwa

Atsuhiko Yoneda

An electric power steering device wherein mechanical friction is electrically provided. A steering torque value is detected by a steering torque sensor according to the operation of a steering wheel. An assist current value is calculated by an assist control section on the basis of the steering torque value. A target current value based on the assist current value is determined. For providing friction to the operation of the steering wheel, a friction control section and a friction torque value/current value conversion section generate a corrected steering torque value. A second corrected target current value is created by correcting a first corrected target current value by a friction current value. The corrected steering torque value is obtained by correcting the steering torque value by a friction torque value. The target current value is generated, resulting in a motor being subjected to driving control.

Electric power steering device

The present invention discloses a controller of an electric power-assist steering system including a torque detector for detecting a torque applied with a steering wheel that steers a steering system; a steering status determining section for determining a steering status of either 'turn' or 'return' of a steering wheel; and a motor controlling unit for driving a motor in accordance with a target current value calculated based on at least a torque value from the torque detector and the steering status of either &#x201c;turn&#x201d; or &#x201c;return&#x201d; of the steering wheel from the steering status determining section, wherein the motor controlling unit sets a target current value right after a time when the steering status is switched between &#x201c;turn&#x201d; and &#x201c;return&#x201d; to be substantially equal to an actual current value right before a time when the steering status is switched between &#x201c;turn&#x201d; and &#x201c;return&#x201d;.

Controller of electric power-assist steering system

An electric steering system includes a steering torque measuring device for measuring a steering torque input into a steering system, a steering speed measuring device for measuring a steering speed of the steering system; a target current computing section for computing a target current based on the steering torque measured by the steering torque measuring device, and a control section for applying a steering power to the steering system by driving a motor according to the target current. When the measured steering speed is less than a predetermined speed value, the control section applies damping to the steering system based on the measured steering speed and when it is not the control section performs a control operation of adding a specified steering torque defined when the steering speed is equal to the predetermined speed value and an increment for the steering torque determined in accordance with the steering speed to each other, defining the sum of the addition as a target steering torque, and controlling the target current so that the measured steering torque coincides with the target steering torque.

Electric steering system for rapidly increasing damper gain after steering speed exceeds a specific value

An electric steering system includes a device for measuring a steering input into a steering system; a device for measuring a steering speed; a section for computing a target current based on the steering input; and a control section for applying a steering power to the steering system by driving a motor according to the target current, and applying damping to the steering system based on the steering speed. A rate of increase in a damper gain defined when the steering speed is equal to or greater than a predetermined value is higher than that defined when the steering speed is less than the predetermined value, or the damper gain defined when the steering speed is equal to or greater than a predetermined value has a constant value increased in a step form from values of the damper gain defined when the steering speed is less than the predetermined value.

Growing community of inventors

Moka, Japan

Kazushige Sugamata