Abstract: A controlling method for pulse application to an actuator using a digital controller.A controlling method of an actuator, wherein a deviation is obtained from a command value and its feedback value, the absolute value of said deviation is determined whether it is larger than the minimum reference deviation corresponding to the dead zone, and only when the absolute value of the deviation is larger than the minimum reference deviation, the actuator is driven by a pulse having an application period proportional to the absolute value of the deviation plus a minimum application period stored in the memory of the digital controller.The minimum application period stored in the memory is increased or decreased and renewed depending on the judgement whether the movement volume of the actuator at each pulse application was under, proper or over.

Abstract: A method of controlling a hydraulic actuator which controls the rotational phase angle of the fuel injection pump for the automobile. A satisfactory exhaust gas composition and an appropriate fuel consumption during a warm-up period of the engine are achieved when the oil temperature in the hydraulic actuator is low. The control method for the hydraulic actuator includes the steps of detecting the temperature corresponding to the oil temperature, comparing the detected temperature with the predetermined reference temperature, and making the application period of the command pulse signal for driving the hydraulic actuator longer than the predetermined length when the detected temperature is lower than the predetermined reference temperature.

Abstract: A digital control method for controlling a relative rotational phase angle p.theta. or the like in a fuel injection pump of an automobile. Decision is made of whether two successive deviations Er between the detected values and a target value are larger than a minimum reference deviation Ero or not. If they are larger than the Ero, decision is made of whether the signs of both the deviations are positive and/or negative. If both signs are positive, a given duration dTs is added to a fundamental duration ts of the next command signal for control. If both signs are different, a predetermined duration dTs is subtracted from the fundamental duration ts of the next command signal.

Abstract: A method of detecting the timing of fuel injection in a diesel engine for the regulation of the timing of fuel injection by a fuel injection timing regulator is disclosed. Rotation angle indicating lugs are provided on the crankshaft of the engine connected to the input shaft of the fuel injection timing regulator and on the output shaft of the fuel injection timing regulator to measure the time difference between pulses corresponding to the lugs on the input and output shafts making relative rotation, and a reference rotation angle indicating lug is provided adjacent to each of the lugs provided on one of the input and output shafts to measure the reference timing difference between pulses corresponding to the lugs on the shaft under rotation. The phase angle of the output shaft relative to the input shaft can be accurately calculated on the basis of the former and latter time differences.

Abstract: A method of controlling a digital actuator which controls the fuel injection pump for the internal combustion engine. In the control method for minimizing the difference between the reference command value and the resultant controlled value in response to the reference command value, the command signal is issued in such a way that the time interval from a command signal which has been issued based on the difference and the subsequent command signal is longer than a predetermined period.