摘要:
An engine ECU executes a program including the steps of: calculating an absolute value ΔS(I) of the deviation of the vibration waveform detected by a knock sensor and a knock waveform model from each other at each crank angle; when ΔS(I) greater than threshold value ΔS(0) is present and the number of ΔS(I) greater than threshold value ΔS(0) is equal to or smaller than Q(1), correcting the vibration waveform; calculating a correlation coefficient K which is a value related to the deviation of the corrected vibration waveform and the knock waveform model from each other; and when the number of ΔS(I) greater than threshold value ΔS(0) is greater than predetermined number Q(1), calculating the correlation coefficient K without correcting the vibration waveform. Based on the correlation coefficient K, whether knocking is present or absent is determined.
摘要:
An engine ECU executes a program including the steps of: calculating an absolute value ΔS(I) of the deviation of the vibration waveform detected by a knock sensor and a knock waveform model from each other at each crank angle; when ΔS(I) greater than threshold value ΔS(0) is present and the number of ΔS(I) greater than threshold value ΔS(0) is equal to or smaller than Q(1), correcting the vibration waveform; calculating a correlation coefficient K which is a value related to the deviation of the corrected vibration waveform and the knock waveform model from each other; and when the number of ΔS(I) greater than threshold value ΔS(0) is greater than predetermined number Q(1), calculating the correlation coefficient K without correcting the vibration waveform. Based on the correlation coefficient K, whether knocking is present or absent is determined.
摘要:
An engine ECU executes a program including: the step of increasing a determination value by a correction amount if the number of knock intensities not lower than the determination value is not smaller than a threshold value among knock intensities of a plurality of predetermined number of continuous ignition cycles; and the step of increasing the determination value by a correction amount if the number of knock intensities not smaller than the determination value is not smaller than a threshold value, among knock intensities of a plurality of ignition cycles satisfying the condition that a coefficient of correlation calculated by comparing a vibration waveform and a knock waveform model is not smaller than a threshold value, of the knock intensities of a plurality of predetermined continuous ignition cycles.
摘要:
An engine ECU executes a program including a step of, when it has temporarily been determined that knocking had occurred because of the presence of an integrated value greater than a product of the reference magnitude and coefficient Y among the integrated values of vibration in fourth frequency band D that includes first to third frequency bands A to C, calculating knock magnitude N using the integrated values in the synthesized waveform of first to third frequency bands A to C and correlation coefficient K calculated from a vibration waveform of fourth frequency band D. Based on a comparison between knock magnitude N and determination value V(KX), whether or not knocking has occurred is determined. If there is no integrated value greater than a product of the reference magnitude and coefficient Y, it is determined that knocking has not occurred.
摘要:
An engine ECU 200 includes a bandpass filter (1), a bandpass filter (2), and a bandpass filter (3). The bandpass filter (1) extracts only vibrations at a first frequency band A from the vibrations detected by a knock sensor. The bandpass filter (2) extracts only vibrations at a second frequency band B from the vibrations detected by the knock sensor. The bandpass filter (3) extracts only vibrations at a third frequency band C from the vibrations detected by the knock sensor. The first to third frequency bands A-C are identical in bandwidth. The engine ECU calculates a peak value in magnitude of vibrations in a synthesized waveform of these frequency bands, and determines whether knocking occurred or not based on the peak value.
摘要:
An engine ECU executes a program including a step of, when an absolute value of a difference between a determination value V(KX) used for determining presence or absence of knocking and a maximum value V(MAX) of magnitude value LOG(V), which is obtained by logarithmically converting a magnitude V detected based on a signal sent from a knock sensor, is greater than the product of a standard deviation σ and a coefficient U(3) in a frequency distribution of magnitude values LOG(V) for N cycle(s), setting a value obtained by adding the product of the standard deviation σ and the coefficient U(3) to the maximum value V(MAX) of the magnitude value LOG(V) as the determination value V(KX).
摘要:
An engine ECU executes a program including: determining whether or not a condition for stopping knocking determination is satisfied; setting a flag of stopping correction of a determination value to “ON”; calculating a knock determination level based on the extracted magnitude value; and when the correction stop flag is not “ON”, decreasing or increasing the determination value in accordance with a knock proportion KC that is a proportion of magnitude values greater than the knock determination level. The knock determination level is calculated even when the correction stop flag is “ON”.
摘要:
An engine ECU executes a program including a step of calculating intensity values LOG(V), a step of detecting vibration waveforms, a step of calculating a correlation coefficient K based on vibration waveforms, a step of preparing frequency distribution of intensity values LOG(V) smaller than a threshold V(1) and intensity values LOG(V) in an ignition cycle where correlation coefficient K is larger than a threshold K(1), a step of calculating a knock determination level V(KD) based on a median V(50) and a standard deviation σ of intensity values LOG(V), and a step of counting the number of intensity values LOG(V) larger than knock determination level V(KD) as the number of times that knocking has occurred.
摘要:
An engine ECU executes a program including a step of, when an absolute value of a difference between median value V(50) of magnitude values LOG(V), which is obtained by logarithmically converting a magnitude V detected based on a signal sent from a knock sensor, and a determination value V(KX) used for determining presence or absence of knocking is greater than the product of a standard deviation σ and a coefficient U(3) in a frequency distribution of magnitude values LOG(V) for N cycle(s), setting a value obtained by adding the product of the standard deviation σ and the coefficient U(3) to the median value V(50) of magnitude values LOG(V) as the determination value V(KX).
摘要:
An engine ECU executes a program including the steps of: calculating a correlation coefficient K based on the result of comparing a vibration waveform of an engine and a knock waveform model stored previously; calculating a magnitude value LOG(V) from the magnitude V detected based on a signal transmitted from a knock sensor; creating frequency distribution of magnitude values LOG(V) by using magnitude values LOG(V) in an ignition cycle in which the correlation coefficient K larger than a threshold K(1) is calculated; and counting knock proportion KC by using the created frequency distribution. If the vibration waveform includes a waveform of vibration of noise components, the correlation coefficient K is calculated to be smaller comparing with a case of not including it.