Control system of electromagnetically operated valve

摘要

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.