CONTROL DEVICE

To surely detect a valve-closing inflection point.SOLUTION: An electromagnetic valve drive unit comprises: a maximum detection part for detecting a maximum point when time series data of a differential value of a back electromotive voltage which is generated at a solenoid are changed to reduction from an increase while going back to the data in a reverse direction reverse to a time series; and a valve-closing time detection part for detecting a maximum time being a time of the maximum point as a valve-closing time of a fuel injection valve when performing determination processing for scanning whether or not a reduction amount of the differential value from the maximum point while going back to the time series data in the reverse direction exceeds a prescribed threshold from the maximum point which is detected by the maximum detection part, and there is an event where the reduction amount exceeds the prescribed threshold.SELECTED DRAWING: Figure 1 【課題】閉弁変曲点を確実に検出することができる。【解決手段】ソレノイドにおいて発生する逆起電圧の微分値の時系列データを時系列とは逆方向に遡って増加から減少に変化したときの極大点を検出する極大検出部と、前記極大検出部で検出された前記極大点から前記時系列データを前記逆方向に遡り前記極大点からの前記微分値の減少量が所定の閾値を超えるか否かを走査する判定処理を実行し、前記減少量が前記所定の閾値を超える事象が存在する場合には、当該極大点の時間である極大時間を前記燃料噴射弁の閉弁時間として検出する閉弁時間検出部と、を備える電磁弁駆動装置である。【選択図】図１