摘要:
A plurality of variables representing the characteristics of a knock is obtained from an output signal of a sensor. The variables include a peak value of the knock frequency component in the output signal of the sensor and a waveform correlation coefficient representing the correlation between the waveform of the output signal and an ideal knock waveform, which is the waveform specific to a knock. The peak value and the waveform correlation coefficient are normalized, and a detection distribution is created using the obtained normalized data values. A correlation coefficient for knock determination representing the correlation between the detection distribution and an ideal knock distribution is calculated. The correlation coefficient for knock determination is compared with a predetermined knock determination threshold value, and the knock determination threshold value is corrected in accordance with the comparison result. As a result, the accuracy and the reliability of knock determination are improved.
摘要:
A variable valve timing control apparatus for an engine includes a hydraulic variable valve timing unit and an oil pressure control device. The variable valve timing unit has a plurality of control ranges and an ambiguity range. The apparatus learns a hold control amount for each of the plurality of control ranges when a predetermined condition is satisfied, and the hold control amount is required to control the oil pressure control device to maintain the actual VCT phase. When the target VCT phase is positioned in the ambiguity range, if a difference between the actual and target VCT phases is stably greater than a predetermined value, the apparatus switches the presently-used hold control amount learning value of one control range into the learning value for the other control range in order to compute the VCT control amount.
摘要:
A variable valve timing control apparatus is provided for an internal combustion engine that has a crankshaft, a camshaft, a hydraulic variable valve timing unit, a lock pin, and a hydraulic control valve. The hydraulic control valve is configured to control oil pressure that actuates the variable valve timing unit and the lock pin. The control apparatus switches a control, based on an operational state, between (a) a variable cam timing (VCT) phase control for controlling the VCT phase to a target phase and (b) a lock pin projection control for allowing the lock pin to project. The control apparatus executes, when an abnormality occurs, a foreign object release control for changing a control amount of the hydraulic control valve based on a predetermined pattern, wherein the control apparatus changes the predetermined pattern depending on the abnormality in the execution of the foreign object release control.
摘要:
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.
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 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.
摘要:
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.
摘要:
An engine ECU executes a program including the steps of: detecting a vibration corresponding to a first radial resonance mode by using a band-pass filter, from vibrations sensed by an in-cylinder pressure sensor provided at an upper central portion of the cylinder; calculating knock intensity N based on a result of comparison between the detected waveform and a knock waveform model prepared in advance as a vibration waveform when knocking occurs; determining that knocking occurred when the knock intensity N is larger than a predetermined reference value; and determining that knocking has not occurred when the knock intensity N is not larger than the predetermined reference value.
摘要:
The signal levels of vibration waveform signals outputted by knock sensors are extracted at a filter processing section for each of a plurality of frequency bands. The mean value of the signal levels in the frequency bands at a point in time when variation of the signal levels in the frequency bands is minimum computed, and the mean value is detected as a background level. A knock characteristic parameter, which represents the characteristics of knock, is computed based on the extracted signal levels in the frequency bands. The knock characteristic parameter is compared with the background level to obtain a knock intensity. If the knock intensity is equal to or greater than a knock determination value, it is determined that knock that exceeds a permissible level is occurring. If the knock intensity is less than the knock determination value, it is determined that knock that exceeds the permissible level is not occurring. This configuration permits the background level of the output of the knock sensors to be accurately detected without being influenced by knock or noise.
摘要:
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.