| 摘要 |
PROBLEM TO BE SOLVED: To properly function correction by feedback control even when structural restrictions are imposed on a control input of a cam phase angle using an actuator. SOLUTION: The phase of a cam shaft is varied and controlled by using, for example, a hydraulic type actuator and an actuation amount of the actuator is controlled according to a control duty factor. In a phase angle control routine, a target phase angle Pa is set (at steps S10 and S12) based on a detected operation state and a proportional correction value uP is set (at steps S14-S18) according to a phase angle deviation difference between a detected actual phase angle Pt and the target phase angle. A situation that there is a possibility for structural restriction to be imposed on phase displacement of a cam shaft is decided (at a step S20) by using condition formulas 1-3. When the decision is established, updating of an integrating correction value uP is prohibited. Thereby, the situation that the fluctuation center of the integrating correction value uI contains an error based on 0 is prevented from occurring.
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