Method to control reaction force of an accelerator pedal system

Method to control acceleration of a motor vehicle from a current vehicle speed, wherein the motor vehicle comprises an accelerator pedal system able to generate on an accelerator pedal an added reaction force when depression of the accelerator pedal reaches a given depression level, comprising:

• a) measuring the current vehicle speed;
• b) determining a target speed of the motor vehicle depending at least on the current vehicle speed or determining from the current vehicle speed a maximum acceleration rate;
• c) determining at least one threshold depression level of the accelerator pedal that corresponds to a stabilization of a vehicle speed at the target speed or that corresponds to the maximum acceleration rate;
• d) generating an added reaction force on the accelerator pedal if the depression of the accelerator pedal reaches or is about to reach the threshold depression level;
• wherein at least steps a), b) and c) are automatically repeated as the vehicle speed increases, wherein, in step b), the maximum acceleration rate is calculated according to the following formula:
• Accmax={dot over (V)}spd=G1·Vspd0.7−G2·Vspd−G3·Vspd2+G4·Teng+C1
• wherein:
• Vspd is the current vehicle speed;
• Teng is a current engine torque;
• G1 is an inertia coefficient that is function of a weight of the motor vehicle and of a gear ratio currently engaged;
• G2, G3 and G4 are functions of the weight of the motor vehicle, of the gear ratio currently engaged and of a slope gradient of a road;
• C1 is function of the current vehicle speed, the slope gradient of the road, the weight of the vehicle and the gear ratio currently engaged.

Method to control acceleration of a motor vehicle from a current vehicle speed, wherein the motor vehicle comprises an accelerator pedal system able to generate on an accelerator pedal an added reaction force when depression of the accelerator pedal reaches a given depression level, comprising:

• a) measuring the current vehicle speed;
• b) determining a target speed of the motor vehicle depending at least on the current vehicle speed or determining from the current vehicle speed a maximum acceleration rate;
• c) determining at least one threshold depression level of the accelerator pedal that corresponds to a stabilization of a vehicle speed at the target seed or that corresponds to the maximum acceleration rate;
• d) generating an added reaction force on the accelerator pedal if the depression of the accelerator pedal reaches or is about to reach the threshold depression level;
• wherein at least steps a), b) and c) are automatically repeated as the vehicle speed increases, wherein each repetition of steps b) and c) consists in determining a new maximum acceleration rate and a new threshold depression level that corresponds to the new maximum acceleration rate.

Method to control acceleration of a motor vehicle from a current vehicle speed, wherein the motor vehicle comprises an accelerator pedal system able to generate on an accelerator pedal an added reaction force when depression of the accelerator pedal reaches a given depression level, comprising:

• a) measuring the current vehicle speed;
• b) determining a target speed of the motor vehicle depending at least on the current vehicle speed or determining from the current vehicle speed a maximum acceleration rate;
• c) determining at least one threshold depression level of the accelerator pedal that corresponds to a stabilization of a vehicle speed at the target speed or that corresponds to the maximum acceleration rate;
• d) generating an added reaction force on the accelerator pedal if the depression of the accelerator pedal reaches or is about to reach the threshold depression level;
• wherein at least steps a), b) and c) are automatically repeated as the vehicle speed increases, wherein the maximum acceleration rate or a new maximum acceleration rate is determined to allow the motor vehicle to reach a higher speed that is determined to be between 5 and 30 km/h higher than the current vehicle speed.