TECHNICAL FIELD OF THE INVENTION

The present invention relates to a method for managing a motor vehicle powertrain.

TECHNICAL BACKGROUND OF THE INVENTION

In a motor vehicle, it is of vital importance to optimize the energy consumption of the motor vehicle. Specifically, what with the increasing scarcity and cost of fossil fuels, the regulations regarding pollutant emissions, and the complexity of the powertrains, it is becoming difficult to be able to operate a motor vehicle optimally.

More particularly, in the case of electrically powered motor vehicles, the autonomy is a decisive factor that requires optimal management of the available energy.

SUMMARY OF THE INVENTION

It is an object of the invention to propose a method for managing a powertrain of a motor vehicle that makes it possible better to predict the way in which the tyre will behave in order to assist with optimizing the energy consumption of the motor vehicle.

To this end, the invention relates to a method for managing a powertrain of a motor vehicle, characterized in that it includes the following steps:

a) determining a predictive rolling resistance coefficient for at least one tyre of the motor vehicle;

b) adapting the operation of the powertrain according to the predictive rolling resistance coefficient in order notably to optimize the energy consumption of the motor vehicle.

Advantageously according to the invention, the method makes it possible to determine the future evolution of the rolling resistance coefficient of a tyre incorporated into a motor vehicle. This predictive rolling resistance coefficient is a new value which may be of particular utility to various control systems of a motor vehicle.

Advantageously according to the invention, the method notably makes it possible to control the powertrain of the motor vehicle more finely, by having available the future evolution of the rolling resistance coefficient for each tyre, for example in order to determine when to change gear in a gearbox, in order to adapt the torque applied to the tyre in order to regulate the speed, in order to adapt the movement of an electronic clutch, and more generally to optimize the operation of the motor vehicle.

In addition, in the case of a hybrid motor vehicle comprising several sources of energy, it is particularly beneficial to make use of the future evolution of the rolling resistance coefficient of the tyres in order to determine which source of energy needs to be utilized and/or recharged, and according to what operation. As an ancillary issue, it also becomes possible to better determine the autonomy of the energy sources used and be better able to inform the user of the motor vehicle.

According to other optional features in the implementation of the invention:step a) is carried out on the basis of at least one value out of the pressure, the temperature, the loading and the rotational speed of the tyre, and of characteristic data concerning the tyre;step a) also takes account of the ambient temperature in which the tyre is operating;step a) is carried out using the equation:
Crr(t)=Crrstab(Tamb,C,P,V)·[1+k·(T(t)−Tstab)]in which Crrstabcorresponds to the minimum value for the rolling resistance coefficient, T corresponds to the internal temperature of the tyre, Tstabcorresponds to the stabilized internal temperature of the tyre at the operating point C, P, V, Tamb, and k corresponds to the coefficient of temperature-sensitivity of the rolling resistance;step a) also takes account of the tyre wear of the tyre;step a) is carried out even when the motor vehicle is stationary;step a) is carried out as long as the temperature of the tyre, measured during step a), is higher than a reference temperature;the reference temperature is higher than or equal to the ambient temperature in which the tyre is operating;the adaptation in step b) also takes account of a predictive variation in altitude of the motor vehicle;the adaptation in step b) also takes account of a predictive variation in the speed of the motor vehicle;step b) adapts the operation of a gearbox and/or of an engine of the powertrain.

