Abstract: A combustion state detecting system for an internal combustion engine which is equipped with a combustion state detector for detecting a combustion state of said engine. The system also includes an amplifier having a plurality of amplification factors to amplify or attenuate a combustion signal obtained by the combustion state detector, the amplification factor of the amplifier being arranged to be switchable plural times on the basis of a detection result of the combustion state detector within a predetermined time period of a combustion cycle of the engine. The decision of the combustion state of the engine is made on the basis of an output of the amplifier generated within the predetermined time period. This arrangement allows an A/D converter to input a signal having as great as possible without overflow to improve the detection accuracy of the combustion state of the engine.

Abstract: An engine control apparatus for discriminating each cylinder of an engine comprises a crank angle rotor (M1) having a configuration representing a crank angle of an engine; a crank angle sensor (M2) operatively associated with the crank angle rotor (M1) to generate a crank angle signal in accordance with the configuration of the crank angle rotor (M1). The configuration of the crank angle rotor (M1) includes first and second silent sections. The first silent section is cooperative with the crank angle sensor (M1) to constitute a part (M3) for generating a first level non-pulsation component of the crank angle signal. The second silent section being cooperative with said crank angle sensor to constitute a part (M4) for generating a second level non-pulsation component of the crank angle signal.

Abstract: The knock control apparatus for an internal combustion engine comprises a knock detecting unit, a knock intensity value detecting unit for detecting a knock intensity value from a knock detecting output signal of the knock detecting unit within a predetermined crank angle range, a unit for calculating a mean value of the knock intensity value, a unit for calculating a mean deviation between the knock intensity value and the mean value, a cumulative percentage point updating unit for updating a cumulative percentage point of the distribution of the knock intensity value, a first updated quantity calculating unit for calculating a first updated quantity based on the knock intensity value and the cumulative percentage point, a second updated quantity setting unit for setting a second updated quantity for updating the cumulative percentage point updating unit based on the magnitude relationship between the first updated quantity and the mean deviation, a knock decision level calculating unit for calculating a kno

Abstract: A knocking control system for an internal combustion engine which is capable of surely detecting and reducing the knock of the engine. The knocking control system is equipped with a logarithmic conversion section for performing the logarithmic conversion of the effective knock intensity of the output signals of a knock sensor and a central value detecting section for detecting a central value in the logarithmic conversion value distribution. The deviation between the central value and the logarithmic conversion value is averaged to obtain an average value corresponding to the standard deviation of the logarithmic conversion value, thereby producing a knock decision level on the basis of the average value. The knock decision level is compared with the logarithmic conversion value so that the occurence of the knock is determined in accordance with the comparison result and the ignition timing of the engine is controlled in accordance with the determination result so as to reduce the knocking state.

Abstract: A control apparatus for an internal combustion engine having: a sensor for detecting a running condition of the internal combustion engine; a detector for detecting information indicative of the running condition in accordance with an output signal of the sensor; and a controller for controlling the internal combustion engine in accordance with a detection result of the detector, the controller communicating with the detector through a signal line is characterized in that: the detector includes sending circuit for sending the information by change in level of the signal lines from the last outputted information and the controller comprises: a reading circuit for reading level of the signal line; a memory for storing the read level of the signal line; a restoring circuit for restoring the information in accordance with the change of level read at this time from the level stored at the last time; a setting circuit for setting an amount of controlling of the internal combustion engine in accordance with restored

Abstract: A knock generation control system for engines has a knock sensor for detecting a knocking phenomenon occurring in an engine, a representative value detecting unit for detecting representative values V from output signals of the knock sensor which are effective for the detection of a knock, a standard deviation detecting unit for detecting a quantity SGM corresponding to a standard deviation of a frequency distribution of logarithmic conversion values lV of the representative values V, a cumulative percentage point detecting unit for detecting a value V.sub.P of a cumulative percentage point of the frequency distribution, a knock decision level setting unit for setting a knock decision level V.sub.KD in accordance with the detected quantity SGM and the detected value V.sub.P, a knock detecting unit for detecting generation of a knock in accordance with the representative values V and the knock decision level V.sub.

Abstract: A knock control system for the internal combustion engine is disclosed in which a knock intensity value V is detected from a signal produced by a knock sensor, a cumulative percentage point V.sub.P of distribution of a substantially logarithmic conversion value of the knock intensity value V is detected, a value S corresponding to the standard deviation of the substantially logarithmic conversion value is detected, and a knock decision level V.sub.KD is prepared on the basis of V.sub.P and S, thereby controlling knock control factors such as ignition timing and air-fuel ratio. The control system further comprises a device for deciding whether a predetermined period has passed after the engine enters specified operating conditions, a device for averaging knock intensity values, and an update quantity setting device for increasing the unit quantity of updating the averaging device and/or the cumulative percentage point detection device only while the predetermined period has not passed.

Abstract: A knock control apparatus for an internal combustion engine which prevents variation of a control knock sound even if an output of a knock sensor is varied due to the variations in performance among different engines or knock sensors, aging of the engine or knock sensor or the like. A given correction quantity is added to an average value of an output signal of the knock sensor, and the sum is increased K times by a K-value varying with the operating conditions of the engine, thereby generating a knock discrimination level. In accordance with the presence or absence of knocking determined by comparing the knock discrimination level and an output signal of the knock sensor, a knock control factor, e.g., ignition timing, supercharge pressure or the like of the engine is controlled.

Abstract: A knock control system for an internal combustion engine has a knock discrimination level. If an output signal from a knock sensor is higher than the knock discrimination level, then the knock control system determines that the engine is subjected to knock and retards the ignition timing. If the knock sensor output signal is lower than the knock discrimination level, i.e., if no knock or detonation is detected over a prescribed period of time, then the ignition timing is advanced. The knock discrimination level is corrected such that a probability that the maximum value of the knock sensor output signal will exceed the knock discrimination level is greater in a knock control range than outside of a knock control range.

Abstract: Disclosed is an anti-knocking control system for controlling an internal combustion engine to prevent knocking in accordance with a knocking condition detected by a knock detecting apparatus on the basis of a distribution pattern of knock magnitude values derived from the output signal of a knock sensor. The knock detection apparatus is arranged to derive a knock magnitude value from the output signal of the knock sensor generated within a predetermined engine rotational angle at an interval thereby obtaining a plurality of knock magnitude values, determine a pattern of distribution of the plurality of the knock magnitude values on the basis of the results of comparison between the frequency that the knock magnitude value exceeds an upper threshold value and the frequency that the knock magnitude value goes below a lower threshold value, and detect a knocking condition of the engine in accordance with the determined distribution pattern.

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: A knock control system for an internal combustion engine has a knock discrimination level. If an output signal from a knock sensor is higher than the knock discrimination level, then the knock control system determines that the engine is subjected to knock and retards the ignition timing. If the knock sensor output signal is lower than the knock discrimination level, i.e., if no knock or detonation is detected over a prescribed period of time, then the ignition timing is advanced. At least two corrective levels are established for comparison with a knock discrimination level, and occurrences in which the maximum value of the output signal from the knock sensor exceeds the corrective levels. The knock discrimination level is automatically corrected dependent on the counts of such occurrences.

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.