METHOD FOR CONTROLLING TRACTION TORQUE IN AN ELECTRIC VEHICLE AS A FUNCTION OF THE VEHICLE'S MASS

Abstract

The invention relates to a method for controlling the torque delivered to the wheels of an electrically driven motor vehicle by an electric traction motor. The method comprises providing a basic torque map (8) to be delivered to the wheels, as a function of accelerator pedal travel and vehicle speed, for each driving mode and for a reference mass (Mref), and repeating the following steps: determining the vehicle's current effective mass (Meff) during driving; calculating a mass correction coefficient proportional to the ratio of the effective mass to the reference mass; modifying the map values ​​according to the mass correction coefficient; and applying the modified torque values, adapted to the effective mass, as a function of the current accelerator pedal travel and instantaneous vehicle speed. Figure 2

Claims

that the basic torque mapping is established with a reference vehicle in half payload configuration.

7. Method according to any one of claims 1 to 6, characterized in that to determine the current effective mass of the vehicle (Meff), coefficients linked to road laws established for a plurality of test masses Mpn of test vehicles are used, said coefficients linked to road laws are coefficients named FO, Fl and F2 derived from the formula Pw = ((FO + F1*VV + F2*VV2) + (Mpn*g*pp))*VV / 3600, where g is the acceleration of Earth's gravity, pp is the percentage of the local slope of a road traveled, PW is the power delivered to compensate for the resistance to forward movement at speed VV.

8. Method according to any one of claims 1 to 7, characterized in that the basic torque mapping comprises between 200 and 300 digital values.

9. Method according to any one of claims 1 to 8, characterized in that in the step of applying said torque values ​​adapted to the effective mass, a linear interpolation is carried out between the points of the mapping.

10. Motor vehicle comprising a traction battery, an inverter, an electric motor and a control unit, characterized in that the control unit is configured to implement the method according to one of claims 1 to 9.

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