Abstract: A valve control system for controlling an electromagnetic valve unit is arranged to execute an initialization control for moving a movable member to a start position by alternatively energizing valve opening and closing electromagnets according to a natural frequency of a vibration system of the electromagnetic valve unit. The valve control system detects amplitudes of oscillation of the movable member during the initialization control and calculates an increase-degree of the detected amplitudes. Further, the valve control system estimates a friction quantity of the vibration system on the basis of the calculated increase-degree and controls electric current supplied to the electromagnets on the basis of a control parameter reflecting the estimated friction quantity.

Abstract: A valve control system for controlling an electromagnetic valve unit is arranged to detect a characteristic of a free vibration of a vibration system in the electromagnetic valve unit when a pair of electromagnets of the electromagnetic valve unit are de-energized and to estimate at least one of a friction quantity and a spring constant of the vibration system on the basis of the detected characteristic of the free vibration. The control system executes the control of the electromagnetic valve unit on the basis of a control parameter determined by one of the estimated friction quantity and the estimated spring constant. This arrangement improves a certainty of softly landing a movable member of the electromagnetic valve unit on the electromagnets.

Abstract: A valve control system for controlling an electromagnetic valve unit is arranged to detect a characteristic of a free vibration of a vibration system in the electromagnetic valve unit when a pair of electromagnets of the electromagnetic valve unit are de-energized and to estimate at least one of a friction quantity and a spring constant of the vibration system on the basis of the detected characteristic of the free vibration. The control system executes the control of the electromagnetic valve unit on the basis of a control parameter determined by one of the estimated friction quantity and the estimated spring constant. This arrangement improves a certainty of softly landing a movable member of the electromagnetic valve unit on the electromagnets.

Abstract: A valve control system for controlling an electromagnetic valve unit is arranged to execute an initialization control for moving a movable member to a start position by alternatively energizing valve opening and closing electromagnets according to a natural frequency of a vibration system of the electromagnetic valve unit. The valve control system detects amplitudes of oscillation of the movable member during the initialization control and calculates an increase-degree of the detected amplitudes. Further, the valve control system estimates a friction quantity of the vibration system on the basis of the calculated increase-degree and controls electric current supplied to the electromagnets on the basis of a control parameter reflecting the estimated friction quantity.