METHOD FOR PREVENTING AN ENGINE FROM STALLING USING AN ESTIMATE OF THE ROTATABLE SPEED OF SAID ENGINE

摘要

A method for preventing the stalling of the engine of a hybrid vehicle (1) equipped with an auxiliary motor (4), generally an electric motor, and with related equipment, namely wheels (R1 to R4), pistons (2a to 2d), tank (3), axle (5), drive shaft (6), gearbox (7), connections (8a, 8b), and computer (9). The method uses an estimate of the predicted instantaneous speed of the main engine (2) at its next top dead center, for the purpose of assisting the main engine in a stall situation, via the auxiliary motor which can supply sufficient power to it on a one-off basis to prevent it from stopping. The method defines two levels of instantaneous speed. If the predicted instantaneous speed is located in the intervention zone between the two levels, the auxiliary motor assists the rotation of the main engine to enable it to rotate in the same direction, without stalling.

主权项

1. A method for preventing a main engine (2) of a vehicle (1) from stalling, said main engine (2) being an internal combustion engine and having pistons (2a to 2d) which each perform a cycle in a cylinder to rotate a crankshaft driving a primary drive shaft (6), the vehicle (1) also comprising an auxiliary electric motor (4) for assisting the main engine (2) by means of two pulleys (8a, 8b) and a drive belt (8c), a gearbox (7), means for measuring the rotation speed of the main engine (2), and means (9) for controlling the auxiliary motor (4), comprising calculation and information storage tools, wherein:
an estimate of the rotation speed of said main engine (2) for a predefined subsequent angular position of the crankshaft is used, said rotation speed of the main engine (2) being estimated on the basis of a prediction of the instantaneous rotation speed (V1, V2, V3) of the crankshaft, called the predicted instantaneous speed; an intervention zone (Z) is defined between two minimum speeds (Nmin1, Nmin2) of the crankshaft at said predefined subsequent angular position, namely a higher minimum speed (Nmin1) above which the engine is considered not to be in a stall situation, and a lower minimum speed (Nmin2), below which the stalling of the main engine is considered to be inevitable; if the predicted instantaneous speed for the predefined subsequent angular position is in the intervention zone (Z), in which there is a risk of stalling of the engine, or below this intervention zone, said auxiliary motor (4) is started as long as said predicted instantaneous speed is below a predefined threshold, to assist the rotation of the main engine (2) so that the latter continues to rotate in the same direction.