Method and apparatus for influencing a motor torque

1 . A method of influencing an actual engine torque delivered by an engine ( 6 ) which is part of drive means ( 7 ) of a vehicle, wherein the actual engine torque (M i ), at an uphill oriented starting operation or at an uphill travel, is determined as a function of a determined roadway inclination (Θ*) which represents a roadway inclination in the travel direction,

characterized in that

a brake pedal variable (s) is determined which represents a driver-caused deflection of a brake pedal ( 9 ) cooperating with braking means ( 30 ) of the vehicle, and the actual engine torque (M i ) delivered by the engine ( 6 ) is further determined as a function of the determined brake pedal variable (s).

2 . The method as defined in claim 1 ,

characterized in that

the actual engine torque (M i ) is determined in such a manner as a function of the roadway inclination (Θ*) that the vehicle assumes, independently from the roadway inclination, a low travel speed (v f ) which, in particular, has a typical magnitude for a creeping motion of a vehicle provided with an automatic transmission or an automatic gearbox or a transmission with an automatic clutch.

3 . The method as defined in claim 1 ,

characterized in that

a magnitude for a nominal engine torque (M s ) is determined as a function of the roadway inclination (Θ*) and the brake pedal variable (s) and that the actual engine torque (M i ) is set in accordance with the determined magnitude of the nominal engine torque (M s ).

4 . The method as defined in claim 3 ,

characterized in that

the brake pedal variable (s) has a range defined by a lower limit (s a ) corresponding to the non-actuated state of the brake pedal ( 9 ) and an upper limit (s b ) corresponding to a maximum possible deflection of the brake pedal ( 9 ), wherein the magnitude of the nominal engine torque (M s ) decreases from a maximum magnitude (M s,max ) at the lower limit (s a ) toward the upper limit (s b ).

5 . The method as defined in claim 4 ,

characterized in that

for magnitudes of the brake pedal variable (s) which correspond to an intermediate magnitude (s 0 ) lying in the range between the lower limit (s a ) and the upper limit (s b ), the nominal engine torque (M s ) assumes a constant, particularly zero, magnitude.

6 . The method as defined in claim 4 ,

characterized in that

the maximum nominal engine torque (M s,max ) as a function of the roadway inclination (Θ*) is determined by the equation M s,max =M 0 s,max +k.|Θ*|, wherein k is a factorial function and M 0 s,max is the engine torque (M s ) obtained by the idling regulator of the engine at a set travel stage on a roadway without inclination.

7 . The method as defined in claim 6 ,

characterized in that

the factorial function (k) is selected in such a manner that at least in the lower limit (s a ) of the brake pedal variable (s) the vehicle assumes, independently from the roadway inclination, a low travel speed (v f ) which is particularly typical for a creeping motion of a vehicle having an automatic transmission, or an automatic gearbox or a transmission with an automatic clutch.

8 . The method as defined in claim 3 ,

characterized in that

the nominal engine torque (M s ) is additionally determined as a function of a vehicle mass variable representing the mass of the vehicle and/or as a function of a rolling resistance variable characterizing the rolling resistance of the driven wheels traveling on the roadway.

9 . The method as defined in claim 4 ,

characterized in that

as a function of the brake pedal variable (s), in the wheel braking devices ( 29 ) of the vehicle a braking force (F v ) is generated which increases from the lower limit (s a ) toward the upper limit (s b ).

10 . The method as defined in claim 5 ,

characterized in that

the intermediate magnitude (s 0 ) of the brake pedal variable (s) is determined as a function of the roadway inclination (Θ*).

11 . The method as defined in claim 5 ,

characterized in that

the intermediate magnitude (s 0 ) is determined as a function of the roadway inclination (Θ*) in such a manner that the vehicle is maintained at a standstill on an inclined roadway by the braking force (F v ) generated in the wheel braking devices ( 29 ) at the intermediate magnitude (s 0 ).

12 . The method as defined in claim 11 ,

characterized in that

the intermediate magnitude (s 0 ) is determined as a function of the roadway inclination (Θ*) in such a manner that when the magnitude of the brake pedal variable (s) falls below the intermediate magnitude (s 0 ) toward the lower limit (s a ), the braking force (F v ) generated in the wheel braking devices ( 29 ) and the actual engine torque (M i ) effected by the nominal engine torque (M s ) maintain the vehicle at a standstill on an inclined roadway oriented in a driver-selected direction, until the actual engine torque (M i ) effected correspondingly to the nominal engine torque (M s ) becomes large enough at a sufficiently small magnitude of the brake pedal variable (s) for setting the vehicle in uphill motion on the inclined roadway.

13 . The method as defined in claim 1 ,

characterized in that

the roadway inclination (Θ*) is determined from a longitudinal roadway inclination (Θ) which represents a roadway inclination in the length direction of the vehicle, a transverse roadway inclination (Φ) which represents a roadway inclination in the transverse direction of the vehicle and a yaw angle (β) which represents a yaw angle of the vehicle.

14 . The method as defined in claim 13 ,

characterized in that

the longitudinal roadway inclination (Θ) is determined from a difference between a total acceleration or a total deceleration in the length direction of the vehicle and a longitudinal vehicle acceleration or a longitudinal vehicle deceleration, obtained from a speed change in the length direction of the vehicle and/or the transverse roadway inclination (Φ) is determined from a difference between a total acceleration or a total deceleration in the transverse direction of the vehicle, obtained from a speed change in the transverse direction of the vehicle.

15 . The method as defined in claim 14 ,

characterized in that

the longitudinal vehicle acceleration or the longitudinal vehicle deceleration and/or the transverse vehicle acceleration or the transverse vehicle deceleration are determined as a function of the change in time of a wheel rpm variable representing the wheel rpm of at least one of the driven vehicle wheels, while a steering angle (δ) is taken into account which represents a steering angle set by a steering wheel ( 25 ) at the steerable vehicle wheels.

16 . The method as defined in claim 1 ,

characterized in that

a recognition of the uphill-directed start operation or uphill travel is effected by an evaluation of a gear shift variable (x g ) which represents the gear set by the driver or a travel stage variable (x g ′) which represents the automatically set travel stage and by an evaluation of the roadway inclination (Θ*).

17 . The method as defined in claim 3 ,

characterized in that

the influencing of the actual engine torque (M i ) is effected in a previously determined travel speed range, and the influencing of the actual engine torque (M i ) decreases with increasing travel speed (v f ).

18 . An apparatus for influencing an actual engine torque delivered by an engine ( 6 ) which forms part of drive means ( 7 ) of a vehicle, wherein the apparatus comprises means ( 15 , 16 , 17 , 25 , 26 , 27 ) with which a roadway inclination (Θ*) representing a roadway inclination in the travel direction is determined and further comprises means ( 8 , 17 ) with which the actual engine torque (M i ) is determined during an uphill-directed start operation or an uphill travel as a function of the determined roadway inclination (Θ*),

characterized in that

means ( 9 , 10 , 17 ) are provided with which a brake pedal variable (s) is determined which represents a driver-caused deflection of a brake pedal ( 9 ) cooperating with braking means ( 29 ) of the vehicle and that the actual engine torque (M i ) delivered by the engine ( 6 ) is further determined as a function of the determined brake pedal variable (s).