Control of a variable valve timing

1. A method for controlling a variable valve timing system, the variable valve timing system comprising one or more intake camshaft(s) and one or more exhaust camshaft(s) and a crankshaft, the method comprising:

determining a reference minimum speed position of the crankshaft associated with a current phase shift of a specific camshaft;

controlling a phase shift of the specific camshaft relative to the crankshaft;

determining a specific minimum speed position, the specific minimum speed position corresponding to an angular position of the crankshaft during a cycle for which the speed of rotation of the crankshaft passes through a minimum;

determining a difference in the specific minimum speed position between the specific minimum speed position and the reference minimum speed position; and

determining a phase shift of the specific camshaft relative to the crankshaft on the basis of the difference in the specific minimum speed position.

2. The method as claimed in claim 1 , wherein the reference minimum speed position is associated with an angular position of the specific camshaft corresponding to a basic phase shift of the specific camshaft relative to the crankshaft.

3. The method as claimed in claim 1 , wherein the method is implemented as long as a difference between the controlled phase shift and the determined phase shift is greater than a predetermined threshold.

4. The method as claimed in claim 1 , wherein controlling a phase shift of the specific camshaft comprises estimating a minimum control speed position, the minimum control speed position corresponding to the reference minimum speed position of the crankshaft to which a variation in the minimum speed position is added, with the variation in the minimum speed position corresponding to a difference between the current phase shift and the controlled phase shift of the specific camshaft.

5. The method as claimed in claim 1 , wherein determining the phase shift of the specific camshaft comprises a correspondence between the difference in the specific minimum speed position and a difference in the phase shift of the specific camshaft.

6. A computer program product comprising program code instructions recorded on a computer-readable medium such as a processor, a controller or a microcontroller for implementing the steps of the method as claimed in claim 1 when said program is implemented by said computer such as a processor, a controller or a microcontroller.

7. A variable valve timing system comprising an intake camshaft and an exhaust camshaft, characterized in that it comprises a computer configured to implement a method for controlling a variable valve timing system as claimed in claim 1 .

8. The system as claimed in claim 7 the system is devoid of a camshaft target and of a camshaft position sensor.

9. A heat engine, comprising a variable valve timing system as claimed in claim 7 , and configured to charge an electrical energy storage means when it is operating.

10. A vehicle comprising an electric propulsion means and comprising a heat engine as claimed in claim 9 .