Closed loop spark control method and system utilizing a combustion event sensor to determine borderline knock

摘要

A method and system to determine the borderline spark timing for a given speed and load of a given cylinder and control spark timing relative to that borderline spark timing to maintain the torque/efficiency of the engine. The system measures combustion related events at several steps from a retarded spark timing to a spark timing signal which is calculated to be beyond the borderline spark timing value. From these measurements, the borderline spark timing signal for a given cylinder at a given speed and load is determined and saved. Borderline spark timing is the spark timing at which audible knock starts to occur.