The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 1999
Filed:
Apr. 07, 1998
Yoshito Nakamura, Wako, JP;
Yasuo Shimizu, Wako, JP;
Honda Giken Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An electric power steering apparatus includes a steering assist torque control system in which a steering torque signal is input and a motor speed signal is output. The control system includes a main control value setting section having a gain KTT and setting a target assist torque value corresponding to the steering torque, a differential-value correction value setting section having a gain KTD and setting a differential-value correction value corresponding to a differential steering torque value, a motor having an inertial efficiency JM and a counter electromotive force (induced voltage) constant KE, a motor drive section incorporated in a controlled object and having a proportional gain KP, a steering speed correction value setting section having a gain KTR and setting a steering speed correction value corresponding to the motor speed signal. The ratio of the gain KTD to the gain KTT is set to satisfy the condition: KTD/KTT>JM/{.alpha.(KP.multidot.KTR+KE)} where .alpha.=KT/(R+KP), R is the resistance (winding resistance) of the electric motor, and KT is the torque constant of the electric motor. With this arrangement, the phase of a gain of the steering assist torque control system is advanced, thereby improving the response characteristic to a level at least comparable to the manual steering mechanism.