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:
Sep. 26, 1989
Filed:
Apr. 13, 1988
Katsuji Marumoto, Hitachi, JP;
Tsutomu Ohmae, Hitachi, JP;
Toshiyuki Koterazawa, Hitachi, JP;
Kazuaki Tobari, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The steering power assist control comprises a main assist control and an auxiliary assist control. When an abnormality occurrence signal from the main assist control is inputted to an abnormality state detection and changing decision circuit 134, the selector circuit changes the PWM signal from the main assist control side to the auxiliary assist control side and outputs the PWM signal to a motor drive circuit. When the main assist control fails, the auxiliary assist control immediately takes over the main assist control to provide, if the operation condition permits, a continued steering power assist control. This prevents an abnormal steering state of the vehicle that would otherwise result when the steering power assist is suddenly lost.