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. 12, 1990
Filed:
Sep. 21, 1988
Applicant:
Inventors:
Hideji Yoshida, Hashima, JP;
Nobuhiro Hayakawa, Chita, JP;
Akio Mizutani, Nagoya, JP;
Tessho Yamada, Nagoya, JP;
Assignee:
NGK Spark Plug Co., Ltd., Nagoya City, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ;
U.S. Cl.
CPC ...
73 232 ; 73116 ;
Abstract
A control system has a controlled element, such as an element for sensing an air/fuel ratio of an internal combustion engine, having a high order lag, a controller element connected with the controlled element to form a closed path, and a third element connected with the controlled element and controller element for modifying an output signal of the controlled element in accordance with an output signal of the controller element so that a phase angle in a frequency response of a loop transfer function of the controlled and controller elements does not reach -180.degree..