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, 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 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 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:
A band pass filter processing extracts the vibration component (frequency component) of the 1st to the 4th order frequency band from the output of the knock sensor. A primary frequency band is established as the frequency band containing the fundamental frequency (primary resonance frequency) which is the lowest frequency of the knocking vibration frequencies. The 2nd to the 4th order frequency band is established as the frequency band containing the 2nd to the 4th order resonance frequency. Based on the vibration strength of the primary frequency component, the comparison result between the composite vibration waveform which compounded the 1st to the 4th order frequency component and the ideal knock waveform, and the vibration strength of the summation of the 1st to the 4th order frequency component, the noise and knocking are distinguished from each other with sufficient accuracy.
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.
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.
摘要:
An engine ECU executes a program including the steps of: comparing a vibration waveform of an engine and a knock waveform model stored in advance to calculate a correlation coefficient K; prohibiting correction when a correction prohibiting condition of a determination value V(KX) is satisfied, the determination value V(KX) compared with a knock magnitude N calculated from the correlation coefficient K so as to control the ignition timing; and correcting the determination value V(KX) based on a magnitude value LOG(V) calculated from a magnitude V of vibration in an ignition cycle in which the correlation coefficient K greater than a threshold value K(1) is calculated when the correction prohibiting condition of determination value V(KX) is not satisfied. The correlation coefficient K is calculated as a smaller value when the vibration waveform includes a waveform of vibration of a noise component as compared with that when the vibration waveform does not include it.
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.