Method and system for determining angular crankshaft position prior to a cranking event

摘要

Method, control system and computer-readable medium are respectively provided for determining angular crankshaft position prior to a cranking event of an internal combustion engine. Upon issuance of an engine shutdown command, the method allows determining an initial crankshaft position based on a crankshaft position sensor (12). The method further allows providing a rulebase (24) for relating angular travel of a rotor in an accessory device (e.g., 16) to crankshaft angular travel. Angular travel of the rotor in the accessory device is sensed (e.g., 18) since issuance of the engine shutdown command until the engine reaches a resting position. The rulebase (24) is accessed to relate the value of the angular travel of the rotor in the accessory device to crankshaft angular travel and provide an incremental crankshaft angular travel relative to the initial crankshaft position at engine shutdown. Crankshaft position is calculated (e.g., 26) at the resting position based upon the initial crankshaft position plus the incremental crankshaft angular travel based on the angular travel of the rotor in the accessory device. The calculated crankshaft position corresponding to the resting position is stored (e.g., 28). Upon issuance of an engine re-start command, the stored crankshaft position corresponding to the resting position is retrieved (e.g., 14) to provide quick and accurate engine control regardless of any dead-band in the crankshaft position sensor during low engine speeds.