초록 ▼

A system and method for detecting and determining an engine knocking for an internal combustion engine are disclosed in which a whole frequency band of an engine vibration detection signal derived from piezoelectric element type knocking sensor is divided into a plurality of frequency regions or ban

A system and method for detecting and determining an engine knocking for an internal combustion engine are disclosed in which a whole frequency band of an engine vibration detection signal derived from piezoelectric element type knocking sensor is divided into a plurality of frequency regions or bands, the vibration levels indicated by the respective frequency signal components or the vibration detection signal and extracted according to the respective frequency bands are compared with threshold levels. According to a result of comparisons, the knocking detecting and determining system determines an occurrence of engine knocking.

대표청구항 ▼

A system for detecting and determining an engine knocking for an internal combustion engine comprising: a) knocking vibration sensing means, installed on the engine, for sensing engine vibrations and outputting an engine vibration detection signal indicative of the engine vibrations, said engine vib

A system for detecting and determining an engine knocking for an internal combustion engine comprising: a) knocking vibration sensing means, installed on the engine, for sensing engine vibrations and outputting an engine vibration detection signal indicative of the engine vibrations, said engine vibration detection signal being output during a predetermined interval of time in each combustion stroke of respective cylinders; b) first means for extracting first vibration levels for a plurality of frequency components of the engine vibration detection signal and for generating second vibration levels corresponding thereto; c) second means for deriving a sum of the second vibration levels of the respective frequency components as a third vibration level; and d) third means for comparing the sum derived by said second means with a preset threshold level and outputting a knock occurrence signal when said sum exceeds the threshold level; wherein said first means comprises a plurality of bandpass filters connected in parallel to each other and connected to said knocking vibration sensing means; wherein said threshold level is set using the following: {BGL×SL+OFS}, wherein BGL denotes a weight mean value of a previous value and a present value of the third vibration level S3, SL denotes a threshold value, and OFS denotes an offset quantity; wherein said first means includes an engine crankshaft rotation sensor for detecting an engine revolution speed by detecting an engine crankshaft rotation and outputting a crank angle signal indicating the engine revolution speed and wherein said threshold value SL is set larger as the engine revolution speed is increased; wherein said third means determines that the engine knocking occurs when the third vibration level S3 equals or is larger than {BGL×SL+OFS}; and wherein said third means determines that no knocking occurs when S31-k)ㆍBGL+kㆍS3, wherein k denotes a weight coefficient of the present value of BGL with respect to the previous value of BGL.