KNOCK CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE

• Main Authors: NAKADA KOICHI, KOKUBO NAOKI, YAMAURA TOSHIAKI, MOGI KAZUHISA
• Format: Patent
• Language: English
• Published: 26.11.1999
• Edition: 6
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; COMBUSTION ENGINES; CONTROLLING COMBUSTION ENGINES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; IGNITION, OTHER THAN COMPRESSION IGNITION, FORINTERNAL-COMBUSTION ENGINES; LIGHTING; MECHANICAL ENGINEERING; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To determine the presence or absence of knocks precisely in consideration of a variation in the knock determination level caused by a variation in the background noise level that is superposed on a knock signal waveform. SOLUTION: A knock sensor 10 detects knock strength values, which are accumulated into the total whose half point is used as a median and from which a value in correspondence with the standard deviation thereof is computed. The background noise(BGN) level that is calculated from the standard- deviation-correspondent value is added to or subtracted from the knock strength values into a value in correspondence with a standard deviation for knock detection. The knock strength values are compared with a knock determination level prepared from the median and the knock-detection-standard-deviation- correspondent value against any influence by a variation in the BGN level, which comparison determines the presence or absence of knocks. The procedures make a precise determination of the presence or absence of knocks from the knock strength values, and permit appropriate control of the operating conditions of an internal-combustion engine.