Abstract: An engine ECU executes a program including the steps of: detecting a waveform of vibration of an engine at a predetermined knock detection gate; determining whether a detected vibration's waveform and a knock waveform model stored in memory match within a predetermined range; if the model and the detected vibration's waveform match within the predetermined range, determining that the engine knocks; and if the model and the detected vibration's waveform do not match within the predetermined range, then determining that the engine does not knock.

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 engine ECU executes a program including a step of calculating coefficient of correlation K that is a value related to a deviation between a vibration waveform and a knock waveform model by comparing the engine's vibration waveform with the knock waveform model stored in advance at a plurality of timings, a step of calculating a knock intensity N as based on a largest coefficient of correlation K among the calculated coefficient of correlation Ks, a step of determining that the engine knocks if knock intensity N is larger than a predetermined reference value (YES at S108), and a step of determining that the engine does not knock if knock intensity N is not larger than a predetermined reference value (NO at S108).

Abstract: A waveform knock signal detected by a knock sensor is filtered through a band-pass filter. The detected wave form signal is compared with an ideal reference knock waveform to determine an engine knock. The ideal reference knock waveform is derived on the basis of a factor depending on a crank angle, a factor depending on a real time and a factor depending on an engine construction. The factor depending on the real time is calculated based on an energy loss in a combustion chamber and a time constant of the band-pass filter. The factor depending on the engine construction is calculated based on a knock vibration which is generated in a cylinder, transferred to a cylinder block and detected by the knock sensor.

Abstract: A knock determining apparatus includes a sensor which outputs a waveform signal corresponding to a knock state, and at least one of a first to a third knock determiner which determines a knock state based on a vibration intensity distribution of the waveform signal. A knock detector compares the vibration intensity of the waveform signal with a threshold, and detects a knock when the vibration intensity exceeds the threshold. This threshold is corrected based on a knock determining result by the first to the third knock determiner.

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 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.

Abstract: An engine ECU executes a program including a step of calculating a knock intensity N as based on comparing a waveform detected as a waveform of a vibration attributed to knocking with a knock waveform model stored in a memory as a waveform of a vibration attributed to knocking for crank angles except for crank angles where a magnitude of a vibration not attributed to knocking is greater than a predetermined magnitude, a step of determining that the engine knocks if knock intensity N is larger than a predetermined reference value, and a step of determining that the engine does not knock if knock intensity N is not larger than a predetermined reference value.

Abstract: A control device of an engine is disclosed that includes a steady controlled variable computing device for computing a steady controlled variable appropriate for a steady operation of the engine. The control device also includes a transient controlled variable computing device for computing a transient controlled variable appropriate for a transient operation of the engine. Furthermore, the control device includes controller that compares the steady controlled variable with the transient controlled variable and selects one of the steady controlled variable and the transient controlled variable on the basis of the comparison. A method of controlling the engine is also disclosed.

Abstract: In determining a knock of an engine, a vibration intensity is calculated by logarithm-transforming a peak value or an integral value of an output signal of a knock sensor. Further, a central value VMED of a vibration intensity distribution is calculated, and also a standard deviation ? in a region where the vibration intensity is smaller than this central value VMED is calculated. A vibration intensity reference value VIB is calculated as VMED?u×?, thereby setting the vibration intensity reference value VIB to be close to a minimum of the vibration intensity distribution. Further, a knock reference value KCK is set by adding a predetermined value K to the vibration intensity reference value VIB. The vibration intensity detected by the knock sensor is compared with the knock reference value KCK to determine presence/absence of a knocking.

Abstract: For each predetermined crank angular interval, an output of a knock sensor is separated into a plurality of frequency components through a plurality of band-pass filters, and peak values of each frequency component are extracted. Then, a mean and a variance of the peak values are computed for each frequency component. A maximum one of the computed means is selected, and the corresponding frequency component, which is associated with the maximum mean, is selected. It is then determined whether the noise is present based on a ratio between the variance of the selected frequency component and the corresponding mean. If the noise is detected in any of the frequency components, execution of knock determination may be prohibited, or ignition timing feedback control according to a result of the knock determination may be prohibited, or ignition timing may be corrected by retarding the ignition timing.

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: A knock determining apparatus includes a sensor which outputs a waveform signal corresponding to a knock state, and at least one of a first to a third knock determiner which determines a knock state based on a vibration intensity distribution of the waveform signal. A knock detector compares the vibration intensity of the waveform signal with a threshold, and detects a knock when the vibration intensity exceeds the threshold. This threshold is corrected based on a knock determining result by the first to the third knock determiner.

Abstract: 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.

Abstract: 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.

Abstract: 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 ? 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.

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: A knock waveform model (thick line) is prepared by correcting a line (thin line) representing an average value of a vibration waveform measured in advance to have more moderate inclination. The knocking determination device determines whether knocking occurred in an engine or not, based on a result of comparison between the knock waveform model and a waveform detected by a knock sensor.

Abstract: An engine ECU executes a program including a step of calculating a knock intensity N as based on comparing a waveform detected as a waveform of a vibration attributed to knocking with a knock waveform model stored in a memory as a waveform of a vibration attributed to knocking for crank angles except for crank angles where a magnitude of a vibration not attributed to knocking is greater than a predetermined magnitude, a step of determining that the engine knocks if knock intensity N is larger than a predetermined reference value, and a step of determining that the engine does not knock if knock intensity N is not larger than a predetermined reference value.

Abstract: An engine ECU executes a program including a step of calculating coefficient of correlation K that is a value related to a deviation between a vibration waveform and a knock waveform model by comparing the engine's vibration waveform with the knock waveform model stored in advance at a plurality of timings, a step of calculating a knock intensity N as based on a largest coefficient of correlation K among the calculated coefficient of correlation Ks, a step of determining that the engine knocks if knock intensity N is larger than a predetermined reference value (YES at S108), and a step of determining that the engine does not knock if knock intensity N is not larger than a predetermined reference value (NO at S108).