Abstract: An internal combustion engine knock controlling apparatus is obtained that improves knock detection performance by making a correction period appropriate without performing matching, when calculating a transition correction factor for correcting a filter coefficient used for calculating a mean value and a standard deviation of a knock signal in a transitional operation state. A previous value of a filter coefficient for calculating a knock determination threshold value that has been corrected by a transition correction factor is used for a filter coefficient for calculating the transition correction factor so that the response characteristics are made equal between a filtering process used for calculating a transition correction factor for correcting a knock determination threshold value and a filtering process used for calculating the knock determination threshold value in a transition operation period.

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: In order to obtain a knock detection device of an internal combustion engine which satisfies two objects of following capability and separation from a continuous knock generation state, when a background level is calculated by ((current background level)=(filter coefficient)×(previous background level)+(1?filter coefficient)×(output signal from knock sensor)), updating quantity of the background level is limited by ((1?filter coefficient)×(value not lower than maximum value of output signal from knock sensor at time when knock is not generated)).

Abstract: A knock control apparatus for an internal combustion engine includes a knock signal normalization portion that normalizes a knock signal using base statistics calculated on the basis of the knock signal. The knock signal normalization portion calculates base statistics on the basis of a last value and a current value of the knock signal and normalizes the knock signal using a base statistic interpolated according to an operating state.

Abstract: There are provided a combustion start determination unit that determines whether or not the inner-cylinder state of an internal combustion engine has changed from a non-combustion state to a combustion state; and a filter coefficient changing demand unit that outputs a filter coefficient changing demand until a predetermined filter coefficient changing period elapses from the time instant when the combustion start determination unit determines that the inner-cylinder state of the internal combustion engine has changed from the non-combustion state to the combustion state to the time instant. Based on the filter coefficient changing demand, at least one of a background level calculation unit and a standard deviation calculation unit changes the value of a filter coefficient utilized in a filtering operation to the one with which a filtering effect is weakened.

Abstract: An operation status value detection unit detects two or more operation status values indicating an operation status of an internal combustion engine. A filtering processing unit applies filtering processing to the detected operation status values, and an operation status value difference calculation unit calculates the difference between the filter-processed operation status value and the corresponding non-filter-processed operation status value so as to calculate two or more operation status value differences. An operation status value difference normalization unit normalizes the two or more operation status value differences, based on predetermined reference values for the two or more operation status values, so as to calculate two or more normalized operation status value differences; and a transient correction unit corrects a control amount for controlling output of the internal combustion engine, based thereon, when the engine is in a transient-operation mode.

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: 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: 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 knock control apparatus includes: a knock sensor for detecting knock of an internal combustion engine; a signal processing section for calculating a knock intensity; and knock determination level setting sections: for calculating an average value of the knock intensity; for calculating, based on the average value, an overall variance of the knock intensity of an entirety of a frequency distribution, a higher variance of the knock intensity above the average value, and a lower variance of the knock intensity below the average value; for calculating a standard deviation of the knock intensity from the overall variance; for presetting a value allowing the frequency distribution of the knock intensity to be a predetermined confidence interval as a confidence coefficient; and for setting a sum of the average value and a value obtained by multiplying the standard deviation by the corrected confidence coefficient as a knock determination level.

Abstract: A knock control apparatus includes: a knock sensor for detecting knock of an internal combustion engine; a signal processing section for calculating a knock intensity; and knock determination level setting sections: for calculating an average value of the knock intensity; for calculating, based on the average value, an overall variance of the knock intensity of an entirety of a frequency distribution, a higher variance of the knock intensity above the average value, and a lower variance of the knock intensity below the average value; for calculating a standard deviation of the knock intensity from the overall variance; for presetting a value allowing the frequency distribution of the knock intensity to be a predetermined confidence interval as a confidence coefficient; and for setting a sum of the average value and a value obtained by multiplying the standard deviation by the corrected confidence coefficient as a knock determination level.

Abstract: A control apparatus for an internal combustion engine, comprising crank angle calculation means for calculating a crank angle between edges which are detected by a first crank angle sensor and a second crank angle sensor, on the basis of a crank cycle between the edges, and engine-rotation-direction detection inhibit means for inhibiting detection of an engine rotation direction on the basis of the calculated crank angle, wherein the engine-rotation-direction detection inhibit means inhibits the detection of the engine rotation direction in a case where the crank angle calculated by the crank angle calculation means has satisfied a predetermined inhibit decision condition.

Abstract: A control apparatus for an internal combustion engine, comprising crank angle calculation means for calculating a crank angle between edges which are detected by a first crank angle sensor and a second crank angle sensor, on the basis of a crank cycle between the edges, and engine-rotation-direction detection inhibit means for inhibiting detection of an engine rotation direction on the basis of the calculated crank angle, wherein the engine-rotation-direction detection inhibit means inhibits the detection of the engine rotation direction in a case where the crank angle calculated by the crank angle calculation means has satisfied a predetermined inhibit decision condition.

Abstract: An oxygen sensor deterioration diagnosis apparatus includes an oxygen sensor provided in an exhaust system of an internal combustion engine, an air-fuel ratio control unit for controlling an air-fuel ratio, an operation state detection unit for detecting an operation state of the internal combustion engine, an inversion period measurement unit for detecting an inversion period of an output signal of the oxygen sensor, an oxygen sensor deterioration diagnosis unit for performing a deterioration judgment by comparing the inversion period with a previously set judgment period, and a deterioration diagnosis inhibiting unit for inhibiting, when the operation state detection unit detects the operation state of the internal combustion engine having an influence on the inversion period, the measurement of the inversion period in a period of time of the detection.