Method for determining whether a crankshaft of an internal combustion engine rotating forward after a reverse rotation is oscillating or continues the forward movement

1. A method for determining whether a crankshaft of an internal combustion engine rotating forward after a reverse rotation is oscillating or is continuing its forward movement, with the internal combustion engine having an electronic operation control unit and a sensor device in order to determine the rotational angle of the crankshaft or of a value depending thereon and the rotational direction of the crankshaft, the method comprising the steps of:

when a reverse rotation of the crankshaft is detected, determining the covered rotational angle during the reverse rotation or the value depending thereon,

computing an actual threshold by means of adding the covered rotational angle or the value depending thereon during a reverse rotation and a predetermined safety distance, and

comparing the rotational angle that the crankshaft covers during a forward movement following the reverse rotation, or the value depending thereon to the actual threshold.

2. The method according to claim 1 , wherein the initiation of system events which depend on the angular position of the crankshaft is prevented during the identified reverse rotation and is only enabled again when the rotational angle of the crankshaft or the value depending thereon exceeds the actual threshold during the forward movement following the reverse rotation.

3. The method according to claim 1 , wherein an error in the sensor device is detected when the rotational angle of the crankshaft or the value depending thereon exceeds the actual threshold during the forward movement following the reverse rotation.

4. The method according to claim 1 , wherein the method is applied during a start process of the internal combustion engine.

5. A system for determining whether a crankshaft of an internal combustion engine rotating forward after a reverse rotation is oscillating or is continuing its forward movement, comprising an internal combustion engine having an electronic operation control unit and a sensor device in order to determine the rotational angle of the crankshaft or of a value depending thereon and the rotational direction of the crankshaft, opwherein the electronic operation control unit and sensor are operable

to determine, when a reverse rotation of the crankshaft is detected, the covered rotational angle during the reverse rotation or the value depending thereon,

to compute an actual threshold by means of adding the covered rotational angle or the value depending thereon during a reverse rotation and a predetermined safety distance, and

to compare the rotational angle that the crankshaft covers during a forward movement following the reverse rotation, or the value depending thereon to the actual threshold.

6. The system according to claim 5 , wherein the initiation of system events which depend on the angular position of the crankshaft is prevented during the identified reverse rotation and is only enabled again when the rotational angle of the crankshaft or the value depending thereon exceeds the actual threshold during the forward movement following the reverse rotation.

7. The system according to claim 5 , wherein an error in the sensor device is detected when the rotational angle of the crankshaft or the value depending thereon exceeds the actual threshold during the forward movement following the reverse rotation.

8. A method for an electric controller unit to control system events of an internal combustion engine, the method comprising the steps of:

detecting a reverse rotation of a crankshaft associated with the internal combustion engine,

upon said detection of said reverse rotation, determining the covered rotational angle during the reverse rotation, or a value depending thereon,

computing an actual threshold by means of adding the covered rotational angle or the value depending thereon and a predetermined safety distance,

comparing the rotational angle that the crankshaft covers during a forward movement following the reverse rotation, or a value depending thereon, to the actual threshold; and

controlling the internal combustion engine so that the system events may only occur in the event that the crankshaft has covered the actual threshold.

9. The method according to claim 8 , wherein an error in the sensor device is detected when the rotational angle of the crankshaft or the value depending thereon exceeds the actual threshold during the forward movement following the reverse rotation.

10. The method according to claim 8 , wherein the method is applied during a start process of the internal combustion engine.