Patent ID: 9556756
Date: 2017-01-31
CPC Classifications: F01L,F02D

Claim:
1. A method, to be executed by a computer device, for estimating the angular position of a crankshaft of a 4-stroke internal combustion engine prior to synchronization of the engine, said engine comprising at least one cylinder comprising a piston configured to move between a top dead center and a bottom dead center, the movement of the piston driving the crankshaft and a plurality of camshafts provided with a number n of targets (CAM_i) secured respectively to n camshafts of said plurality of camshafts, each target defining a plurality of events over one revolution of the camshaft to which the target is secured, the crankshaft being provided with a securely-attached target (CRK) comprising a plurality of standard teeth and at least one reference tooth which define a plurality of events over one crankshaft revolution, the estimating method comprising: determining a precision to be achieved in estimating a range of plausible positions (Pos_Crk) of the crankshaft prior to synchronization, then estimating a range of plausible positions (Pos_Crk) of the crankshaft prior to synchronization, at a given moment, from events detected on said n camshaft targets, correlated with events detected on the crankshaft target, as corresponding to the shortest angular window that is common to all the members of rank i using the following formula: where: repeating said estimate of a range of plausible positions of the crankshaft prior to synchronization, at a later moment, until said precision that is to be achieved in estimating a range of plausible positions of the crankshaft prior to synchronization is obtained.