Abstract: A knock control apparatus has a knock sensor and a signal processor. The signal processor integrates a knock sensor signal and differentiates the integrated signal. The signal processor detects a period in which the differentiated signal exceeds a threshold, and detects a peak of the differentiated signal. The signal processor then calculates a ratio between the detected signal generation period and the detected peak to determine a knock when the calculated ratio is within a predetermined range. Alternatively, the signal processor detects a peak generation time and calculates a ratio between the detected signal generation period and the detected peak generation time. In this instance, the signal processor determines the knock when the calculated ratio is within a predetermined range and the detected peak generation time is less than a predetermined time reference.

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 has a knock sensor and a signal processor. The signal processor integrates a knock sensor signal and differentiates the integrated signal. The signal processor detects a period in which the differentiated signal exceeds a threshold, and detects a peak of the differentiated signal. The signal processor then calculates a ratio between the detected signal generation period and the detected peak to determine a knock when the calculated ratio is within a predetermined range. Alternatively, the signal processor detects a peak generation time and calculates a ratio between the detected signal generation period and the detected peak generation time. In this instance, the signal processor determines the knock when the calculated ratio is within a predetermined range and the detected peak generation time is less than a predetermined time reference.

Abstract: A memory stores and holds both the number of crankshaft angle pulse signals occurring after detecting a reference portion when an engine stops and data relating to whether the reference portion which is supposed to be next detected upon re-start of the engine is a reference position of the camshaft. When the engine is re-started, it is determined whether a reverse rotation of the crankshaft across the reference position happened by comparing a predetermined value with the total obtained by adding the number of pulse signals stored in the memory and the number of pulse signals occurring until the reference portion is first detected again. When such reverse rotation happened, the reference position of the camshaft is shifted by 360.degree. CA. Therefore, regardless of whether such reverse rotation across the reference position happened or not, the engine timing cycle is again precisely synchronized.

Abstract: A signal rotor 6 rotates in synchronism with a crank shaft of the internal combustion engine. A pickup sensor 7 is disposed in a confronting relation to the signal rotor 6 to generate an angle signal S1 proportional to rotation of the internal combustion engine. An ignition signal producing means (31, 32) calculates an ignition timing on the basis of the angle signal S1 and generates an ignition signal (S41, S42) for igniting the internal combustion engine. A time mask means monitors a parameter representative of a battery voltage Vs, and prohibits the angle signal S1 from entering into the ignition signal producing means for a predetermined time in response to a detection of a predetermined amount fluctuation of the parameter.

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.