Patent ID: 6246953
Filing Date: 2001-06-12
Classification: F02D,F02P,Y02T

Abstract:
A knock detection system for a spark ignition internal combustion engine having at least one cylinder with a spark plug, the system comprising:an engine condition sensing arrangement including an engine speed sensor, engine angle sensor and engine noise sensor; andan engine management system arranged to receive input signals from the engine condition sensors and to determine therefrom engine angle and engine noise, wherein the engine management system comprises a nonvolatile memory, a spark plug driver for generating an ignition spark, and a processor arranged to:a) control the spark driver to generate the ignition spark at a desired spark angle according to at least some of the input signals;b) determine over a first range (N2,N3) of engine angles a background engine noise, and determine over a second range (N1) of engine angles an engine knock noise;c) retard the spark angle if the level of knock noise relative to background noise exceeds a first level, and advance the spark angle if the level of knock noise to background noise falls below a second level, wherein the processor is further arranged to select the first range (N2,N3) of angles from a plurality of engine angle ranges stored in the nonvolatile memory based on a signal from the engine speed sensor.