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:
Oct. 21, 1980
Filed:
Nov. 17, 1978
John F Schweikert, Sterling Heights, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A closed loop air/fuel ratio controller for an internal combustion engine includes a control circuit responsive to the output of an exhaust gas sensor representing at least the sense of deviation of the air/fuel ratio of the mixture supplied to the engine from stoichiometry and provides a control signal which is used to adjust the air/fuel ratio of the mixture supplied to the engine in direction tending to restore a stoichiometric air/fuel ratio. The control signal includes an integral correction term and an asymmetrical proportional correction term that abruptly shifts the value of the control signal upon a detected change in at least one direction in the sense of the deviation of the air/fuel ratio from a stoichiometric air/fuel ratio. The asymmetrical proportional term provides either singularly or in combination with an asymmetrical integral term a scheduled air/fuel ratio offset from the stoichiometric air/fuel ratio with the offset value being a function of the system gains and the limit cycle frequency of the control signal that is determined primarily by the transport delay through the engine and exhaust system.