Apparatus and method of controlling the road speed of a motor vehicle

Apparatus for controlling the road speed of a motor vehicle, comprising

• an accelerator pedal, which is spring-biased counter to its actuating direction into an inoperative position and is movable from the inoperative position into a neutral position, from which a further movement of the accelerator pedal counter to the spring bias leads to an increase of the drive torque of the motor vehicle drive, and
• a device for detecting the inoperative position of the accelerator pedal, which is connected to a braking-force generator and which in the inoperative position of the accelerator pedal causes the braking-force generator to make a predetermined braking force available,
• wherein the device for detecting the inoperative position of the accelerator pedal, upon a movement of the accelerator pedal from the inoperative position into the neutral position, causes the braking-force generator to reduce the predetermined braking force in accordance with the accelerator pedal movement and vice versa, and wherein the magnitude of the predetermined braking force is dependent upon the road speed.

Method of controlling the road speed of a motor vehicle, which comprises a brake system and an accelerator pedal, which is biased counter to its actuating direction into an inoperative position and through the actuation of which the instantaneous drive power of the motor vehicle drive may be varied, having the steps:

• injecting a predetermined braking force into the brake system when the accelerator pedal is situated in its inoperative position such that the magnitude of the predetermined braking force is dependent upon the road speed,
• automatically controlled reducing of the predetermined braking force injected into the brake system as soon as the accelerator pedal is moved from its inoperative position towards a neutral position, and automatically controlled building-up of the previously described braking force as soon as the accelerator pedal retains its inoperative position, and
• increasing the instantaneous drive power of the motor vehicle drive by moving the accelerator pedal beyond the neutral position.