Abstract: A misfire detection apparatus includes storage devices that store first mapping data and second mapping data, and execution devices. The execution device executes a first acquisition process, a first calculation process, a second acquisition process, a second calculation process, a determination process of determining whether or not a calculation result of the second calculation process and a calculation result of the first calculation process match, a count process of counting the number of consecutive times when a determination is made in the determination process that there is mismatch, and a transmission process of transmitting, to an outside of the vehicle, data on the value of the second misfire variable corresponding to the maximum number of times among the numbers of consecutive times counted in the count process during a predetermined period and data on the second input data used for calculating the value of the second misfire variable.

Abstract: A motor control apparatus and method for damping engine vibration are provided. The apparatus includes a data collection device that collects engine information and motor information and a processor that determines a magnitude of engine torque vibration using the engine information and the motor information. A weighting value is determined by determining a position of a piston in a cylinder of an engine, ignition timing, an engine angular acceleration, and an engine velocity. A motor arti-phase torque is calculated by reflecting the determined weighting value in the magnitude of the engine torque vibration and a motor is operated based on the motor anti-phase torque to cancel out the engine torque vibration.

Abstract: An object of the present invention is to predict change of a combustion limit due to cycle variation of temperature and an EGR ratio and perform correction every cycle to decrease an amount of combustion consumption. Therefore, in an internal combustion engine control device that controls an internal combustion engine including a cylinder and an exhaust pipe, the internal combustion engine control device includes a control unit configured to perform EGR control of controlling an exhaust gas in the exhaust pipe to return to an inner cylinder of the cylinder, obtain temperature of the gas in the internal cylinder and an EGR ratio in a state where both an intake valve and an exhaust valve are closed in an combustion cycle, and correct a combustion parameter in a same combustion cycle as the combustion cycle on the basis of the obtained gas temperature and the obtained EGR ratio.

Abstract: A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.

Abstract: To provide a controller and a control method, for an internal combustion engine, that can detect occurrence of knocking appropriately, even though the frequency distribution of the knock signal is distorted according to the occurrence state of knocking. The controller for the internal combustion engine calculates the background level by processing a low pass filter to the knock signal; and performs a low side frequency increase which makes a low side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is smaller than an output value of the low pass filter, higher than a high side frequency, which is a cutoff frequency of the low pass filter in the case where the knock signal is larger than the output value of the low pass filter.

Abstract: A method for detecting a combustion process of an internal combustion engine of a hybrid vehicle includes the steps of acquiring a rotational speed signal representing a rotational speed of the crankshaft, acquiring a crankshaft angle signal representing a crankshaft angle of the crankshaft, and determining, based on the rotational speed signal and the crankshaft angle signal, whether a combustion occurs in the internal combustion engine. A control device for detecting a combustion process of an internal combustion engine of a hybrid vehicle is also provided.

Abstract: Knocking and pre-ignition are identified, without contributing to pre-ignition, even when vibration magnitudes and timings of occurrence of the knocking and pre-ignition are the same. When detecting an abnormal combustion that cannot be identified as a knocking or pre-ignition, ignition timing is advanced, at which time knocking is identified when an abnormal combustion intensity increases, and pre-ignition is identified when a difference between ignition timing and abnormal combustion occurrence timing increases.

Abstract: Provided are a knocking determination device and a knocking control device for an internal combustion engine, with which a large amount of knocking can be detected quickly and with which knocking is easily determined. A knocking time window and a bandpass filter (BPF) are used (B1-B2) to extract a knocking frequency waveform signal from a knock sensor signal (Sg1), and integration is performed to obtain a first calculated value (B3). A reference time window and a BPF are used (B4-B5) to extract a reference frequency waveform signal from the knock sensor signal (Sg1), and integration is performed to obtain a second calculated value (B6). The average value of multiple instances of the second calculated value is obtained (B7), and the first calculated value is divided by the average value to obtain a signal-to-noise (S/N) ratio (B8).

Abstract: An ignition timing control device has a knocking detection unit and an ignition timing adjustment unit. In a condition that the operation state of the internal combustion engine is suitable for adjustment of the ignition timing, the ignition timing control device outputs to an igniter an adjusted ignition signal as adjusted (corrected) by an adjusted ignition timing determination process. The ignition timing control device outputs to the igniter a reference ignition signal as it is outputted from an internal combustion engine control unit without adjustment (correction) in a condition that the operation state of the internal combustion engine is not suitable for adjustment of the ignition timing.

Abstract: A system for and a method of knock detection and control for an engine utilizes a knock sensor configured to generate a knock signal indicative of a vibration of the engine caused by abnormal combustion. A controller is configured to receive the knock signal, determine, with respect to a crank angle of the engine, distinct monitoring windows for low speed pre-ignition (LSPI) knock and spark knock, respectively, based on (i) spark timing and (ii) an appropriate mass fraction burn (MFB) location, monitor the knock signal using the distinct monitoring windows, detect one of LSPI knock and spark knock based on the monitoring, and control the engine to mitigate the detected LSPI knock or spark knock.

Abstract: A method of operating a gas or dual fuel engine having a plurality of cylinders, includes monitoring a characteristic of each of the plurality of cylinders during operation of the gas or dual fuel engine. The method also includes detecting a pre-ignition condition associated with one or more cylinders of the plurality of cylinders based on the monitored characteristic. The method further includes reducing fuel supply to the one or more cylinders having the pre-ignition condition. The fuel supply to remaining cylinders of the plurality of cylinders is increased, to maintain a constant power output of the gas or dual fuel engine. The method further includes adjusting an amount of air supplied to each of the plurality of cylinders based on the increased amount of fuel supplied to the remaining cylinders, to maintain an air-to-fuel ratio within a desired range.

Abstract: An engine rotational speed control device (4) includes a noise removal processing unit (6) which corrects a command value, wherein the noise removal processing unit (6) is configured to set a current first output value (B(i)) to be identical to a previous first output value (B(i?1)) in a case where, in a latest step group, the number of successive increase steps is smaller than a first predetermined number (n) and the number of successive decrease steps is smaller than the first predetermined number (n), the increase step is a step in which a current first input value (A(i)) is greater than the previous first output value (B(i?1)) by a first set width (n) or more, and the decrease step is a step in which the current first input value (A(i)) is smaller than the previous first output value (B(i)) by the first set width (n) or more.

Abstract: A semiconductor device has a first and a second external terminals coupled to power supply wiring that couples one end of a current detecting resistance and a power supply terminal of a battery, a third external terminal coupled to an other end of the current detecting resistance, and a control circuit for controlling an output of a second measurement current destined to the third external terminal, and measures a voltage difference between the first external terminal and the second external terminal.

Abstract: A base in-cylinder volume is corrected by a learned value to calculate a corrected in-cylinder volume. A difference of a crank angle which gives the corrected in-cylinder volume and the base crank angle is calculated as a “crank angle correction value”, and a base ignition timing is corrected by the crank angle correction value and feedback correction value. An in-cylinder volume at a crank angle where a combustion ratio became a set ratio at the previous combustion is calculated as a “previous in-cylinder volume VFp”, a difference ?VFp of the previous in-cylinder volume VFp with respect to the base in-cylinder volume VBp at the previous combustion is calculated, and the learned value ?VL is updated based on the in-cylinder volume difference VFp.

Abstract: The invention relates to a method for generating an ion current which occurs as a direct current between a central electrode and one or more side electrodes of a spark plug of a spark ignition engine which is supplied repeatedly with an ignition voltage from an ignition voltage source, wherein the spark ignition engine is assigned an engine control unit, which, in an engine cycle, determines for each spark plug a target ignition point and/or an activation point for the ignition voltage source before the target ignition point, and a second voltage source is provided, which delivers a second voltage for the generation of the ion current, wherein the second voltage source lying in the engine cycle for a first time interval ?t1, which is shorter than the duration of the engine cycle, is connected to the electrodes of the spark plug, and wherein the ion current flowing as a result of the application of the second voltage to the electrodes of the spark plug takes a path which avoids the ignition voltage source.

Abstract: An internal combustion engine control apparatus includes a pseudo knock determination unit that determines whether or not a pseudo knock has been produced in a knock detection window, based on at least one of the frequency, a status amount indicating a rotation speed of the internal combustion engine, a status amount indicating a load of the internal combustion engine, and a status amount indicating an air-fuel ratio of the internal combustion engine; and a moving-average processing unit that sets a second period to a period that is approximately the same as a first period, in the case where it has been determined that the pseudo knock was not produced, and that does not implement moving-averaging or sets the second period to a period that is narrower than the first period, in the case where it has been determined that a pseudo knock was produced.

Abstract: There is provided an ignition timing control device for an internal combustion engine capable of appropriately performing knock learning by performing knock learning adapted to an engine combustion phenomenon. The inventor has found the principle of a knock reduction effect due to ignition retard is that “if a combustion period moves toward the retard side, a cylinder volume during the combustion period increases, resulting in curbing of rise in the temperature and pressure of unburned gas”. An ignition timing control device according to the present invention is capable of new knock learning based on the principle, which learns a “cylinder volume rate”. The cylinder volume rate is a parameter determined from the amount of change in cylinder volume. Even when an operational status changes, learned ignition timing obtained from knock control means can be set to an appropriate value by reflecting the learned cylinder volume rate.

Abstract: A sensor signal processing device includes an AD conversion section, a filter section, a timing signal generation section, and an arithmetic section. The timing signal generation section generates a signal synchronized with a crank angle of an engine based on a signal indicating the crank angle and generates a data acquisition timing signal by compensating the signal synchronized with the crank angle with a delay time of the filter. The arithmetic section acquires a plurality of sensor signals, which is transmitted from a sensor, converted from an analog signal to a digital signal by the AD conversion section, and filtered by the filter section, in a term before and after receiving the data acquisition timing signal and generates a data synchronized with the data acquisition timing signal.

Abstract: A knock control device is provided in which erroneous knock detection can be reduced by suppressing sudden knock signal changes due to noise, without causing any increase in the number of matching steps, deterioration in the S/N in knock detection and decrease in detection performing frequency. In the knock control device, an open gain is applied to the detected signal only during a knock detection window set in advance by a knock window setting means. The window corresponds to a period in which vibration due to knock arises. During other periods, either a closed gain or an interpolated gain value is applied to the detected signal.

Abstract: An engine system for a vessel propulsion device includes an engine including an intake amount adjusting unit and an ignition plug, and configured to generate a drive force for the vessel propulsion device. The engine system includes an ignition timing control unit, a knocking detecting unit, a knocking retard control unit that retards the ignition timing of the ignition plug by a unit retard amount when the knocking detecting unit detects knocking, an abnormality judging unit that, when a state where the knocking detecting unit detects knocking at intervals within a predetermined time continues, judges that an abnormality has occurred based on a continued state of knocking detection, and an intake amount limiting unit that limits the intake amount of the engine based on judgment of an abnormality made by the abnormality judging unit.

Abstract: A knock control apparatus for internal combustion engine includes: a knock signal normalization unit that normalizes a knock signal extracted from an output signal of a knock sensor; a knock determination threshold setting unit that sets a knock determination threshold on the basis of the normalized knock signal; a knock intensity computation unit that calculates knock intensity on the basis of the normalized knock signal and the set knock determination threshold; a knock determination unit that determines a presence or absence of a knock on the basis of the calculated knock intensity; and a knock correction amount computation unit that calculates a knock correction amount to correct the calculated knock intensity in a case where an occurrence of a knock is determined. The knock signal normalization unit normalizes a standard deviation of the knock signal by dividing the knock signal by an average value of the knock signal.

Abstract: In a knock control device of an internal combustion engine equipped with a control unit which updates a background level based on an output signal from a knock sensor and detects the generation of a knock by comparing a variation of the background level with a knock determination value, a determination as to whether the knock is generated is performed by ((variation of first filter value of peak hold value)>((1?filter coefficient)/(1+filter coefficient)×(predetermined value larger than maximum value of variation of peak hold value in case where knock is not generated))).

Abstract: A vibration waveform of a knock-specific frequency component of an internal combustion engine is calculated over a plurality of ignition cycles of the internal combustion engine according to an output of a knock sensor and an output of a crank angle sensor. An actual ignition timing is calculated by detecting a position corresponding to a crank angle at which a standard deviation of the vibration waveform exceeds a predetermined first determination level as a vibration position by combustion of the internal combustion engine.

Abstract: A knock correction amount computation portion computes, on the basis of intensity of a knock in a case where the presence of an occurrence of the knock is determined, a knock correction amount by which to move a spark timing of the internal combustion engine to be on a retard side and returns the knock correction amount to be back on an advance side in a case where the absence of an occurrence of a knock is determined. In a case where a value of the knock correction amount to be on the retard side becomes equal to or exceeds a predetermined value, the knock correction amount computation portion limits and holds the knock correction amount at the predetermined value and returns the limited knock correction amount to be back on the advance side in a case where the absence of an occurrence of a knock is determined.

Abstract: A control system for a vehicle is provided. The control system includes a signal processing module that receives a sensor signal and extracts a plurality of sample points from the sensor signal. A computation module computes a summation of the sample points, computes a summation of squares of the sample points, and computes a standard deviation based on the summation of the sample points and the summation of the squares of the sample points. A control module generates a control signal based on the sensor signal and the standard deviation.

Abstract: A combustion state detection device for an internal combustion engine includes: an ignition control unit that controls activation of a primary winding for ignition; a comparison value setting unit that sets a comparison value with respect to an ion signal; and a combustion state discrimination unit that determines the occurrence of misfire depending on the magnitude of the ion signal with respect to the comparison value; wherein the ignition control unit, after generating a spark, reactivates the primary winding at least one time during one combustion stroke so that an induction voltage similar to that generated in the secondary winding at around a time when the primary winding begins to be activated for the purpose of starting combustion is generated in the secondary winding.

Abstract: Control apparatus for an internal combustion engine including: a second knock detection unit for detecting occurrence of a second knock due to an effective compression ratio when ignition timing is on a retard side of a predetermined value in the case where a first knock is detected; a second knock suppression unit for suppressing the second knock when the second knock is detected; a first abnormal ignition detection means for detecting occurrence of first abnormal ignition due to the pre-ignition or the post-ignition when a knock intensity of the second knock is equal to or larger than a predetermined value; and a first abnormal ignition suppression unit for suppressing the first abnormal ignition by performing fuel control for the internal combustion engine when the first abnormal ignition is detected.

Abstract: In a method and a device for controlling an internal combustion engine (1), the accuracy of the detection of knocking in an internal combustion engine (1) can be increased by determining a reference ignition advance angle for an actual operating point of the internal combustion engine (1) at which the efficiency of the engine is a maximum. An actual ignition advance angle at which the internal combustion engine (1) is to be operated at the actual operating point is determined. Signals from a knocking sensor (14) are detected, allowing conclusions to be drawn concerning a knocking event in a combustion chamber (30) of the internal combustion engine (1). To detect knocking, only the signal values which lie within a predetermined evaluating interval are used, wherein the position of the evaluating interval is determined depending on the difference between the reference ignition advance angle and the actual ignition advance angle.

Abstract: A knock detection apparatus for an internal combustion engine can accurately detect the occurrence of a knock without an influence of a noise component even if the noise component having the same frequency as a knock vibration superposes on an ionic current signal. The apparatus includes an ionic current detection section, a knock signal detection section for detecting a knock signal based on an ionic current, a crank angle sensor for detecting a crank angle corresponding to a rotational position of the engine, a window setting section for setting a noise detection window, a noise component detection section for detecting a noise component in the window, and a knock determination section for determining the occurrence of a knock based on a relation between the noise component and the knock signal. The window setting section sets the window after a predetermined crank angle corresponding to an end of a combustion stroke of the engine.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, an electrical circuit, and a controller. The electrical circuit is configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within the combustion chamber. The controller is configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a crank angle of the IC engine where the incipient knock occurs, and adjust timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond inception of incipient knock.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, and an electrical circuit configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within a combustion chamber. The engine includes a controller configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a spark crank angle timing of the IC engine where the incipient knock occurs, and adjust the spark timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond an incipient knock set point.

Abstract: A system and method for selecting the data content of an ionization feedback signal is disclosed. An ignition system monitors both the ionization signal and ignition coil dwell data. The ignition system outputs either the ionization signal or the ignition coil dwell data on the ionization feedback line, depending on what information is desired by the powertrain control module. In one embodiment, the ionization signal is only output during the before ignition period when the operating condition of the engine indicates possible pre-ignition conditions.

Abstract: Systems and methods are described, including one example method of controlling an engine having a cylinder with at least one valve operated by a variable valve mechanism (VVM) having a sensor coupled to the valve, the method comprising: adjusting at least one operating parameter in response to an indication of detonation of a combustible mixture in the cylinder, the indication based on the sensor coupled to the valve.

Abstract: In a method for operating an internal combustion engine, wherein the internal combustion engine has a cylinder in which a combustion chamber is provided that is delimited by a reciprocating piston guided in the cylinder, wherein the piston is connected by a connecting rod to a crankshaft and wherein the internal combustion engine has a device for supplying fuel and a device for igniting the fuel/air mixture in the combustion chamber at least one engine speed value of the internal combustion engine is determined and evaluated. A pre-ignition state of the internal combustion engine is determined based on the result of the evaluation step.

Abstract: An engine ECU executes a program including the steps of: calculating a knock magnitude N by dividing an integrated value lpkknk obtained by integrating the magnitude of vibration in the knock detection gate by BGL; controlling ignition timing according to a result of comparison between knock magnitude N and a determination value VJ; stopping updating of a standard deviation ? when it is determined that determination value VJ to be compared with knock magnitude N is to be changed; updating a median value VM by increasing an update amount of median value VM; and updating BGL according to median value VM and standard deviation ?.

Abstract: In a knock sensor signal processing apparatus, a first apparatus which receives an engine knock sensor signal performs A/D conversions of the signal with a predetermined period and transmits successive pluralities of A/D values in parallel, by serial data communication, to a second apparatus in response to respective commands received from the second apparatus. The number of communication lines provided for transmitting the A/D values is made greater than those for transmitting commands from the second apparatus to the first apparatus, so that a high A/D conversion frequency together with low data rate of transmitting the A/D values can be achieved, thereby reducing communication-generated noise.

Abstract: An ignition control system which reduces decrease in output of the internal combustion engine and increase in exhaust gas temperature when one spark plug alone is used for ignition is provided. The ignition control system is used for an engine having cylinders, each of which has two spark plugs. The ignition control system includes a first controller having a first ignition timing control section for controlling ignition timing of a first group of spark plugs including a first spark plug of the two spark plugs in each cylinder and a second controller having a second ignition timing control section for controlling ignition timing of a second group of spark plugs including a second spark plug of the two spark plugs in each cylinder. The first and second ignition timing control sections correct ignition timing according to predetermined parameters when one of the two spark plugs is not used in at least one cylinder.

Abstract: In a method and a device for controlling an internal combustion engine (1), the accuracy of the detection of knocking in an internal combustion engine (1) can be increased by determining a reference ignition advance angle for an actual operating point of the internal combustion engine (1) at which the efficiency of the engine is a maximum. An actual ignition advance angle at which the internal combustion engine (1) is to be operated at the actual operating point is determined. Signals from a knocking sensor (14) are detected, allowing conclusions to be drawn concerning a knocking event in a combustion chamber (30) of the internal combustion engine (1). To detect knocking, only the signal values which lie within a predetermined evaluating interval are used, wherein the position of the evaluating interval is determined depending on the difference between the reference ignition advance angle and the actual ignition advance angle.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, and an electrical circuit configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within a combustion chamber. The engine includes a controller configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a spark crank angle timing of the IC engine where the incipient knock occurs, and adjust the spark timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond an incipient knock set point.

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: calculating a magnitude value LOG(V) by logarithmically converting a magnitude V of vibration occurring in an engine, calculating a median V(50) and a standard deviation ? of magnitude values LOG(V); and setting, to the product of the standard deviation ? and a factor A, a first upper limit of a determination value V(KX) that is to be compared with a knock magnitude N for determining whether or not knocking has occurred, and setting a first lower limit of the determination value V(KX) to the product of the standard deviation ? and a factor B.

Abstract: An engine ECU executes a program including: the step (S222) of increasing a determination value V(J) by a correction amount A(3) if the number of knock intensities N not lower than the determination value V(J) is not smaller than a threshold value B(1) (YES at S220) among knock intensities N of a plurality of predetermined number of continuous ignition cycles; and the step (S232) of increasing the determination value V(J) by a correction amount A(5) if the number of knock intensities N not smaller than the determination value V(J) is not smaller than a threshold value B(3) (YES at S230), among knock intensities N of a plurality of ignition cycles satisfying the condition that a coefficient of correlation K calculated by comparing a vibration waveform and a knock waveform model is not smaller than a threshold value K(1), of the knock intensities of a plurality of predetermined continuous ignition cycles.

Abstract: To reliably prevent knocking in all of the cylinders of a multicylinder engine by detecting an output signal from a knock sensor provided for only one of the cylinders. A cylinder barrel is formed with a knock sensor base on the side surface of only the third cylinder and a vibration type knock sensor is mounted on the knock sensor base. A water jacket is formed in an upper portion of the wall of the cylinder barrel. The knock sensor base is formed below the water jacket so as to prevent a problem such that knocking vibrations may be absorbed by the cooling water in the water jacket to cause a reduction in sensitivity of the knock sensor.

Abstract: A system and method for controlling knock in a lean burn internal combustion (IC) engine includes a spark plug having an electrode, an electrical circuit, and a controller. The electrical circuit is configured to provide a first voltage to the electrode and detect an ion current during a thermal-ionization phase of the combustion process, and provide a second voltage to the electrode to create a spark and initiate a combustion process within the combustion chamber. The controller is configured to monitor the ion current for a knock condition that includes at least an incipient knock condition, determine a crank angle of the IC engine where the incipient knock occurs, and adjust timing of the IC engine to operate at a crank angle that does not exceed a threshold level beyond inception of incipient knock.

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).

Abstract: An engine ECU executes a program including the steps of: calculating a magnitude value LOG(V) by logarithmically converting a magnitude V of vibration occurring in an engine, calculating a median V(50) and a standard deviation ? of magnitude values LOG(V); and setting, to the product of the standard deviation ? and a factor A, a first upper limit of a determination value V(KX) that is to be compared with a knock magnitude N for determining whether or not knocking has occurred, and setting a first lower limit of the determination value V(KX) to the product of the standard deviation ? and a factor B.

Abstract: To reliably prevent knocking in all of the cylinders of a multicylinder engine by detecting an output signal from a knock sensor provided for only one of the cylinders. A cylinder barrel is formed with a knock sensor base on the side surface of only the third cylinder and a vibration type knock sensor is mounted on the knock sensor base. A water jacket is formed in an upper portion of the wall of the cylinder barrel. The knock sensor base is formed below the water jacket so as to prevent a problem such that knocking vibrations may be absorbed by the cooling water in the water jacket to cause a reduction in sensitivity of the knock sensor.

Abstract: A knocking determining apparatus of an internal combustion engine that includes an in-cylinder injector and an intake port injector and that determines knocking based on an output signal of a knock sensor. The knocking determining apparatus includes a knocking determination prohibition unit prohibiting, when a ratio of fuel injection from the in-cylinder injector and the intake port injector is changed, knocking determination for a prescribed period after that change, or a knocking determination level change unit changing a knocking determination level for a prescribed period after that change.

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 knock detection apparatus which is capable of changing a knock control starting time period appropriately so as to prevent erroneous knock determination, to thereby expand a knock control range. A peak value acquisition unit acquires a peak value of a vibration of an internal combustion engine during each rotation cycle of a crankshaft of the engine. A background calculator calculates a background by averaging peak values acquired by the peak value acquisition unit. A knock determination unit performs knock determination based on whether a peak value acquired by the peak value acquisition unit is higher than a predetermined level above the background, and feedback controls knock in the engine according to a result of the knock determination. A temperature acquisition unit acquires a temperature of the engine during a start of the engine.