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. 18, 1994
Filed:
Mar. 11, 1993
Hirohiko Yamada, Anjo, JP;
Koji Sakakibara, Hekinan, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
A knock control system for an internal combustion engine derives a knock intensity indicative value Vpi from an output of a knock sensor and decides presence or absence of an engine knock by comparing the knock intensity indicative value Vpi and a knock decision level V.sub.KDi for controlling a knock control factor such as an ignition timing based on the decision. The system derives a value Si corresponding to a standard deviation of a distribution of a substantially logarithmic conversion value of the knock intensity indicative value Vpi, and a value V.sub.Mi corresponding to a median value of the above-noted distribution. The system derives the knock decision level V.sub.KDi based on the value Si and the value V.sub.Mi when the value Si is within a predetermined range. On the other hand, when the value Si deviates from the predetermined range, the system derives the knock decision level V.sub.KDi based on the value V.sub.Mi and a corrected value which is set smaller or larger than the value Si so as to prevent divergence of the knock decision level V.sub.KDi.