Abstract: A knock control apparatus for engine has a knock sensor for detecting vibrations of the engine. The knock control apparatus determines an occurrence of knock by using at least one of a statistical process, a waveform process and a FFT process. The knock control apparatus desirably uses at least two of the above-described process for improving the accuracy of knock determination. The knock control apparatus learns a corrective value during a stable condition of the engine. The learned value is used for determining an ignition timing when the engine is in a transitional condition. Therefore, it is possible to detect a knock accurately, and reduce a knock when the engine is in the transitional condition.

Abstract: A knock control apparatus for engine has a knock sensor for detecting vibrations of the engine. The knock control apparatus determines an occurrence of knock by using at least one of a statistical process, a waveform process and a FFT process. The knock control apparatus desirably uses at least two of the above-described process for improving the accuracy of knock determination. The knock control apparatus learns a corrective value during a stable condition of the engine. The learned value is used for determining an ignition timing when the engine is in a transitional condition. Therefore, it is possible to detect a knock accurately, and reduce a knock when the engine is in the transitional condition.

Abstract: A basic cylinder-charged air quantity is determined by a first-order delay processing of an intake air quantity per rotation. Next, an estimated value of a change portion of the cylinder-charged air quantity caused by a change in intake valve timing is computed on the basis of engine speed, throttle opening angle, displacement angle of the intake valve timing. Then, the estimated value of the change portion of the cylinder-charged air quantity is processed second-time by the first-order delay. A difference between the estimated value of a change portion of the cylinder-charged air quantity and a value obtained by processing the estimated value second-time by the first-order delay is added as a delay correction to the basic cylinder-charged air quantity, thereby obtaining an actual cylinder-charged air quantity with a change in the intake valve timing.

Abstract: To ensure both responsiveness and stability of a knock determination in which a knock sensor signal is compared with a knock determining reference computed from a background value, a difference between the knock sensor signal and the background value is determined through averaging by the use of the averaging coefficient. Based on the difference, the averaging coefficient n is varied so that the more latest sensor output signals are used in the background value determination as the difference becomes larger.

Abstract: A control system equipped with a misfire detection apparatus for an internal combustion engine comprising a first storage for storing a data train indicative of a record of a predetermined number of the operation states detected at a predetermined interval and a second storage for storing a reference data train indicative of a reference record of a predetermined number of reference operation states. The misfire detection apparatus further includes a comparison calculator for comparing each data constituting the data train stored in the first storage with each data constituting the reference data train stored in the second storage to obtain a comparison result between the entire data train and the entire reference data train. The comparison result supplied to a decision section to decide that the engine is in a predetermined state when the comparison result is out of a predetermined range.

Abstract: A control system equipped with a misfire detection apparatus for an internal combustion engine comprising a first storage for storing a data train indicative of a record of a predetermined number of the operation states detected at a predetermined interval and a second storage for storing a reference data train indicative of a reference record of a predetermined number of reference operation states. The misfire detection apparatus further includes a comparison calculator for comparing each data constituting the data train stored in the first storage with each data constituting the reference data train stored in the second storage to obtain a comparison result between the entire data train and the entire reference data train. The comparison result supplied to a decision section to decide that the engine is in a predetermined state when the comparison result is out of a predetermined range.

Abstract: In a system for controlling knocking in an internal combustion engine, a reference value to be compared with a knock sensor signal for determining the presence or absence of the knocking is corrected in accordance with the pattern of a distribution obtained by collecting the logarithmic transformation value of the maximum value of signal generated from the knock sensor signal within a predetermined engine rotational angle at an interval. This is based on the fact that the pattern of distribution represents the characteristic of knocking of the engine.

Abstract: In a system for controlling knocking in an internal combustion engine, a reference value to be compared with a knock sensor signal for determining the presence or absence of the knocking is corrected in accordance with the pattern of a distribution obtained by collecting the logarithmic transformation value of the maximum value of signal generated from the knock sensor signal within a predetermined engine rotational angle at an interval. This is based on the fact that the pattern of distribution represents the characteristic of knocking of the engine.