Patent ID: 7100554

Claim:
A controller for controlling a valve operating characteristic of engine valves for a plurality of cylinder groups included in an internal combustion engine, the controller comprising: a plurality of variable mechanisms, each provided for an associated one of the cylinder groups, for varying the valve operating characteristic of the associated cylinder group; a plurality of lock mechanisms, each provided for an associated one of the variable mechanisms, for locking operation of the associated variable mechanism to maintain the valve operating characteristic of the associated cylinder group at a lock value; a setting means for setting a target value for the valve operating characteristic based on an operating condition of the engine; a drive means for driving each of the variable mechanisms so that the valve operating characteristic approaches the target value; a determination means for determining whether the operation of the variable mechanism associated with each lock mechanism is locked; and a restriction means for restricting the target value for the valve operating characteristic of at least one of the variable mechanisms of which operation is unlocked when the operation of at least one of the variable mechanisms is locked so that difference between the target value and the lock value decreases.