Engine-knock detection method and apparatus

US4444042A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Jorg Bonitz · Mühlacker, DE
• Robert Entenmann · Memmingen, DE
• Rochus Knab · Kornwestheim, DE
• Siegfried Rohde · Schwieberdingen, DE
• Herbert Schramm · Leonberg, DE

Key dates

• Filing date: Aug 20, 1981
• Grant date: Apr 24, 1984
• Expiry date: Aug 20, 2001

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L23/225
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An amplitude envelope signal is derived from the output of an engine-knock sensor. Either the peak value of the envelope signal or its steepest rate of rise initiates the operation of a delay circuit providing a signal after a delay that is dependent upon the magnitude of the peak value or rate of rise. The envelope signal is also compared with a reference signal responsive to or representing or simulating background noise levels, and a comparison signal is produced when the envelope signal exceeds the reference signal. Engine-knock recognition is determined by the coincidence of the comparison signal and the delayed signal, and may be subjected also to a measurement window criterion which limits the appearance of an engine-knock signal to a particular arc of crankshaft revolution.