Flame Arrival Sensing Fast Response Double Closed Loop Engine Management

The crank position related arrival time of the flame front at a flame front arrival sensor, positioned in the endgas area of the combustion chamber, controls cycle by cycle the best ignition timing. The jitter amplitude in flame front arrivals at the same flame front sensor (FFS) controls the A/F and/or EGR ratio towards target values. A double closed loop control (DCL) is realized which controls simultaneously the charge composition for minimum brake specific fuel consumption (BSFC) and the co-related ignition timing over the speed load range, considering all varying parameters like octane requirement increase (ORI), all interesting temperatures, as exhaust valve, piston deck, engine oil and water etc., fuel variables as CHO ratio, MON, density, viscosity, ambient conditions as humidity and altitude, general engine conditions as spark plug erosion, etc., utilizing basically only one extra sensor and control means. Still the same means serve for preknock detecting and control.