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:
Feb. 24, 1998
Filed:
Oct. 12, 1995
Mitsuhiko Nishimoto, Kashihara, JP;
Hideki Higashira, Ikoma, JP;
Koyo Seiko Co., Ltd., Osaka, JP;
Abstract
In an electric power steering apparatus, a motor current target value of a steering force assisting motor is determined on the basis of a torque detected by a torque sensor. The drive of the motor is controlled using the motor current target value as a target value of an automatic control, and using the driving current of the motor as a feedback value of the automatic control. When the detected torque is within a predetermined range, the motor is inhibited from being driven in the direction opposite to the detected torque. The electric power steering apparatus has a motor non-drive detecting circuit for detecting that the motor current target value is zero, and a drive inhibition holding circuit for holding the motor drive inhibition state, wherein the motor is inhibited from being driven in the direction opposite to the detected torque, until the motor non-drive detecting circuit detects that the motor current target value is zero. Even when a CPU runs away and the motor current target value becomes excessive, self-rotation of a steering wheel and reverse assist caused by the flow of excess motor current are prevented. Even when a CPU runs away exists and assist and assist inhibition are repeated, steering is prevented from becoming unstable.