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:
Jun. 28, 1988
Filed:
Jul. 02, 1986
Katsuji Marumoto, Hitachi, JP;
Tsutomu Omae, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electric power assistance steering apparatus provides a differential compensating circuit (54) in which a command current signal is added with a derivative of the command signal to provide a compensated current signal to a control circuit for varying the current to an electric motor (11) arranged to provide power assistance to a steering rack (6). The apparatus preferbly provides signals representative of torque and vehicle speed to a function generator to provide a first command signal which is added with a self-centering command current and the output is provided to give a second command current which is effectively the first command current limited in dependence upon the vehicle speed. The second command current is operated upon by the differential compensating circuit (54) to the compensated current signal.