Method for estimating the angular position of a crankshaft for accelerating the starting of an internal combustion engine

摘要

A method for estimating the angular position of a crankshaft of a 4-stroke internal combustion engine prior to synchronization of the engine having a plurality of camshafts provided with a number n of targets (CAM_i) secured respectively to n camshafts, each target defining a plurality of events over one revolution of the camshaft to which it is secured, the crankshaft having a securely attached target (CRK) including a plurality of standard teeth and at least one reference tooth which define a plurality of events over one crankshaft revolution, the method including: estimating a range of plausible positions of the crankshaft prior to synchronization, at a given moment, from events detected on the 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:;Pos_Crk⁢_est=⋂i=1i=n⁢⁢_⁢⁢CAM⁢List_event⁢_plaus⁢_CAM⁢_i+Dist_ang⁢_CRK⁢_since⁢_last⁢_event⁢_CAM⁢_i+Tolerances_i.

主权项

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:Pos_Crk⁢_est=⋂i=1i=n⁢⁢_⁢⁢CAM⁢List_event⁢_plaus⁢_CAM⁢_i+Dist_ang⁢_CRK⁢_since⁢_last⁢_event⁢_CAM⁢_i+Tolerances_i where:
Pos_Crk_est = range of plausible positions of the crankshaft at the given moment,List_event_plaus_CAM_i = all of the plausible events of the rank i camshaft target (CAM_i) at the given moment,Dist_ang_CRK_since_last_event_CAM_i=angular distance covered by the crankshaft, determined by all of the detected events of the crankshaft target (CRK) since the last event detected on the rank i camshaft target (CAM_i), at the given moment,Tolerances_i = angular window of possible positions of the crankshaft, resulting from the angular tolerance on the detection of an event on the rank i camshaft target (CAM_i) and the crankshaft target (CRK), andn_CAM = number of camshaft targets (CAM_i) used in the engine; and 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.