Patent Number: 7,711,470

Title: Control apparatus

Abstract: 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.

Inventors: Wada; Minoru (Obu, JP)

Assignee: DENSO CORPORATION

International Classification: G06F 19/00 (20060101); F01L 1/34 (20060101)

Expiration Date: 5/04/12018