Method and apparatus for calculating minimum valve lift for internal combustion engines

摘要

A controller calculates valve lift of intake and exhaust valves for a cylinder of an internal combustion engine. A first desired pressure ratio (Pcyl/Pint) is selected to minimize induction pumping losses. Maximum cylinder demand is calculated. Intake valve lift is calculated by matching an effective flow capacity through at least one intake valve of the engine to the maximum cylinder demand. The intake valve is actuated based on the calculated intake valve lift. A second desired pressure ratio (Pexh/Pcyl) for minimizing exhaust pumping losses is selected. Maximum cylinder demand is calculated. Exhaust valve lift is calculated by matching an effective flow capacity through at least one exhaust valve of the engine to the maximum cylinder demand. The exhaust valve is actuated based on the calculated exhaust valve lift.