摘要 |
When a variable valve lift control apparatus is in a steady condition, a fluctuation control is performed. In the fluctuation control, a target lift amount is increased by a fluctuation width during an up-time and then the target lift amount is decreased by the fluctuation width during a down-time which is longer than the up-time to be returned to an original value. A decreasing amount of the integral term is greater than the increasing amount thereof. Consequently, the integral term can be made smaller than the original value. Even when a control duty is a larger value due to a hysteresis, the fluctuation control gradually decreases the increment of the integral term and converges the control duty to the small value.
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