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:
Nov. 19, 2002
Filed:
Oct. 16, 2000
Hossein Javaherian, Rochester Hills, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
The switching characteristic of zirconia solid electrolyte type oxygen sensors is shaped to generate a limited proportional range around the stoichiometric A/F through a modified operation of the port injection or direct fuel injection control system. The linear response is obtained by imposing fuel-injection offsets, of particular patterns and magnitudes, on the average fuel quantity determined by the closed-loop fuel controller. The linear range of the sensor is then used for precise stoichiometric A/F control for tailpipe emission improvements. Also, further reductions in HC and CO emissions during cold-start (with leaner air-fuel ratio operation) and reduction in NOx (slightly rich air-fuel ratio operation) under warm-up and hot conditions are made possible using production O sensors.