Abstract: An engine ECU executes a program that includes the steps of: calculating (S204) a median value V(50) and a standard deviation s based on a calculated magnitude value LOG(V); and subtracting (S206) a product of the standard deviation s and a coefficient U(3) from the median value V(50) to calculate BGL. Knocking determination is carried out by comparing a knock magnitude N calculated by dividing the magnitude value LOG(P) by the BGL with a predetermined determination value V(VK). Based on the knocking determination result, ignition timing of the engine is controlled.

Abstract: An engine ECU executes a program including the steps of: calculating an absolute value ?S(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 ?S(I) greater than threshold value ?S(0) is present and the number of ?S(I) greater than threshold value ?S(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 ?S(I) greater than threshold value ?S(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.

Abstract: An engine ECU executes a program including calculating a correlation coefficient by dividing the sum of respective absolute values, which are each a difference between a magnitude in an engine vibration waveform and a magnitude in a knock waveform model for every crank angle, by an area corresponding to magnitudes equal to or larger than a positive reference value in the knock waveform model, and determining whether or not knocking has occurred based on the correlation coefficient.

Abstract: An engine ECU executes a program including the steps of: calculating an absolute value ?S(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 ?S(I) greater than threshold value ?S(0) is present and the number of ?S(I) greater than threshold value ?S(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 ?S(I) greater than threshold value ?S(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.

Abstract: 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.

Abstract: An engine ECU executes a program including the steps of: setting a knock waveform model corresponding to engine speed sensed by a crank position sensor; calculating knock intensity N based on the result of comparison between a detected waveform and the set knock waveform model; when the knock intensity N is larger than a predetermined reference value, determining that knocking has occurred; and when the knock intensity N is not larger than the predetermined reference value, determining that knocking has not occurred.

Abstract: An engine ECU executes: calculating 15-degrees integrated value integrating vibration intensity for each of six crank angle ranges; detecting an amount of change in the 15-degrees integrated value between ignition cycles; specifying two ranges having larger amounts of change; specifying a crank angle having intensity larger than that of a neighboring crank angle in a search range determined to be the same as the specified ranges; calculating a coefficient of correlation K corresponding to a difference between a vibration waveform and a knock waveform model while the specified crank angle is matched with a timing at which intensity peaks in the knock waveform model; and, if the coefficient of correlation K is larger than a threshold value K(0), determining that knock has occurred.

Abstract: An engine ECU includes a bandpass filter (1) extracting only vibrations at a first frequency band A, a bandpass filter (2) extracting only vibrations at a second frequency band B, a bandpass filter (3) extracting only vibrations at a third frequency band C, and a bandpass filter (4) extracting only vibrations at a fourth frequency band D including the first to third frequency bands A-C. The engine ECU determines whether knocking occurred or not based on a vibration waveform of the fourth frequency band D and a peak value in magnitude of vibrations in a synthesized waveform of the first to third frequency bands.

Abstract: 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”.

Abstract: An engine ECU executes a program including a step of calculating intensity values LOG(V) based on signals transmitted from a knock sensor; a step of deciding a maximum value V(MAX) in frequency distribution of intensity values LOG(V) for N cycles (N is a natural number); a step of calculating a knock determination level V(KD) based on the frequency distribution; a step of, when the knock determination level V(KD) is smaller than the maximum value V(MAX), removing V(MAX) from the frequency distribution; and a step of counting the total frequency of removed maximum values V(MAX) as knock occupancy KC. Maximum values V(MAX) are removed until the knock determination level V(KD) and the maximum value V(MAX) coincide, and the knock determination level V(KD) is recalculated.

Abstract: 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.

Abstract: 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 ? 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 ? and the coefficient U(3) to the maximum value V(MAX) of the magnitude value LOG(V) as the determination value V(KX).

Abstract: An output signal of a knock sensor is converted by an A/D conversion part in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from an output signal of the knock sensor, and the time-varying patterns of vibration intensities in multiple frequency ranges are extracted. A knock determination part computes the number of time-varying patterns of vibration intensity which rise at same time. The knock determination part executes a knock determination based on whether the number of the time-varying patterns of vibration intensity is greater than a knock determination threshold.

Abstract: An output signal of a knock sensor is converted by an A/D conversion part in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from an output signal of the knock sensor and the time-varying patterns of vibration intensities in multiple frequency ranges are extracted. A knock determination part computes lengths (crank angle, or time period) from a starting point to a latest terminating point of the time-varying patters of vibration intensity in at least two frequency ranges, which rise at a same time. The knock determination part executes a knock determination based on whether the lengths are greater than a knock determination threshold.

Abstract: A knock sensor signal is converted by an A/D conversion part in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from an output signal of the knock sensor and the time-varying patterns of vibration intensity of multiple frequency ranges are extracted. Contours of the time-varying patterns of vibration intensity in multiple frequency ranges are extracted. Vectors indicating directions along which the vibration intensities vary are approximated by the contour of the time-varying pattern of vibration intensity in each frequency range according to the least-squares method. A knock determination is executed based on whether directions of any two or more of multiple vectors are within a predetermined range. Alternatively, a knock determination is executed based on whether a ratio of length of any two or more of the vectors is within a predetermined range.

Abstract: An output of a knock sensor is A/D converted in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from the knock sensor output signal and the time-varying patterns of vibration intensities in multiple frequency ranges are extracted. An edge direction and an edge intensity are computed by an edge extraction processing. A correlation value expressing a correlation between time-varying patterns of vibration intensities in multiple frequency ranges and a reference model expressing the feature of knock is computed in a mutual correlation/knock determination part. The correlation value is compared with a determination threshold. When the correlation value is larger than the determination threshold, it is determined that knock is caused. When the correlation value is not larger than the determination threshold, it is determined that knock is not caused.

Abstract: An engine ECU executes a program including: a step (S310) of multiplying a correction amount of a determination value V(KX) by Q, when deviation L between an approximation value V(R), which is an average value of determination values V(KX) corrected according to the occurrence frequency of knocking, and an approximation value V(R?1) previously calculated is greater than a predetermined value (NO in S306) or when the number of times where deviation L is determined to be smaller than a predetermined value is smaller than a predetermined number of times (NO in S308); and a step (S312) of multiplying the correction amount of the determination value V(KX) by 1/P, when the number of times where the deviation L is determined to be smaller than a predetermined value is greater than a predetermined number of times (YES in S308). By comparing the determination value V(KX) and knock magnitude, determination of knocking is made, and ignition timing is advanced or retarded.

Abstract: A knocking judgement method for an internal combustion engine, in which an engine ECU executes a program judging whether or not such ones of integrated values calculated by integrating the output of a knock sensor at every five degrees of a crank angle are larger than a tentative knock judgement value, in vibrations of a fourth frequency band containing the resonance frequency of the engine, tentatively judging that a knocking has occurred, in case the integrated value larger than the tentative knock judgement value is a predetermined number or more, and judging that no knocking has occurred, in case the integrated value larger than the tentative knock judgement value is not more than the predetermined number.

Abstract: An engine ECU executes a program including the steps of: calculating a coefficient of correlation K in accordance with a result of comparing a waveform of a vibration of a frequency band including a resonance frequency of an engine with a knock waveform model previously created as a waveform of a vibration caused when the engine knocks (S112); calculating a knock intensity N from an intensity of a vibration of a frequency band excluding the resonance frequency of the engine (S114); if knock intensity N is larger than a reference value and coefficient of correlation K is larger than a threshold value (YES at S116), determining that the engine knocks (S118); and if knock intensity N is smaller than the reference value and/or coefficient of correlation K is smaller than the threshold value, determining that the engine does not knock (S122).

Abstract: An engine ECU executes a program including the steps of: determining that the condition that there is a possibility of occurrence of knocking is satisfied, based on the result of comparison between a vibration waveform of an engine and a knock waveform model; calculating a 40CA integrated value by integrating magnitudes of vibration occurring in the engine for a range of crank angle of 40°; calculating a knock magnitude N by dividing the 40CA integrated value by a BGL; determining that knocking has occurred when the knock magnitude N is larger than a determination value V(KX); and determining that knocking has not occurred when the knock magnitude N is smaller than the determination value V(KX).