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:
Dec. 16, 1986
Filed:
Dec. 24, 1985
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The invention is directed to a method for the formation of an air-fuel mixture for an internal combustion engine, including an oxygen sensor exposed to the exhaust gas and responsive to the oxygen content of the exhaust gas, a signal-processing unit processing the output signals of the oxygen sensor, and a memory store for storing a set of characteristic curves dependent on at least one operating parameter of the internal combustion engine, the characteristic values thereof (F.sub..lambda.) determining the amount of fuel to be metered. In this method, a time-variable perturbation (.DELTA.F.sub..+-.) is superposed on the characteristic values (F.sub..lambda.), the oxygen sensor output signals (U.sub..lambda.) are evaluated with regard to their change due to the perturbation (.DELTA.F.sub..+-.), and the characteristic values (F.sub..lambda.) are suitably corrected to achieve an optimum air-fuel ratio. In this arrangement, the modulation frequency of the characteristic values (F.sub..lambda.) is to assume as high values as possible while the modulation amplitude is to be as low as possible. This method permits a substantial increase in the limit frequency of the Lambda sensor operation cycles.