Method and device for operating a motor vehicle
First Claim
1. A method for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position to generate a drive torque, the method comprising:
- detecting a wheel slip at another vehicle, which has an electronic stability program, based on the speeds of the wheels of the another vehicle;
determining, via a control unit of the another vehicle, an effective coefficient of friction of a roadway from the wheel slip;
continuously determining a present position of the another vehicle on the roadway through a satellite-based navigation system of the another vehicle;
transmitting the effective coefficient of friction of the another vehicle on the roadway to a central database, where the effective coefficient of friction of the another vehicle is stored together with the present position of the another vehicle;
carrying out, at the motor vehicle, an engine drag-torque control to avoid skidding of the drive wheel when the accelerator pedal arrives back in a neutral position; and
specifying a maximum permissible engine drag torque to the engine drag-torque control as a function of a currently effective coefficient of friction, received from the central database and as determined by the another vehicle and stored in the central database, of a road surface that is determined as a function of a present position of the motor vehicle;
wherein the engine drag-torque control is adapted to an instantaneous driving situation and roadway condition, so that skidding of the drive wheel owing to a drag torque is prevented, andwherein with a vehicle sensor system, as a function of a wheel speed and a vehicle longitudinal acceleration, an actual engine drag torque is monitored, wherein a slip model is used to determine whether one of the drive wheels is skidding, wherein an engine drag-torque control is carried out, where the maximum permissible engine drag torque is predetermined.
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Accused Products
Abstract
A method for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position in order to generate a drive torque, an engine drag-torque control being carried out to avoid skidding of the drive wheel when the accelerator pedal is moved in the direction of a neutral position. It is provided that a maximum permissible engine drag torque is specified to the engine drag-torque control as a function of a currently effective coefficient of friction of the road surface which is determined as a function of a present position of the motor vehicle.
30 Citations
25 Claims
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1. A method for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position to generate a drive torque, the method comprising:
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detecting a wheel slip at another vehicle, which has an electronic stability program, based on the speeds of the wheels of the another vehicle; determining, via a control unit of the another vehicle, an effective coefficient of friction of a roadway from the wheel slip; continuously determining a present position of the another vehicle on the roadway through a satellite-based navigation system of the another vehicle; transmitting the effective coefficient of friction of the another vehicle on the roadway to a central database, where the effective coefficient of friction of the another vehicle is stored together with the present position of the another vehicle; carrying out, at the motor vehicle, an engine drag-torque control to avoid skidding of the drive wheel when the accelerator pedal arrives back in a neutral position; and specifying a maximum permissible engine drag torque to the engine drag-torque control as a function of a currently effective coefficient of friction, received from the central database and as determined by the another vehicle and stored in the central database, of a road surface that is determined as a function of a present position of the motor vehicle; wherein the engine drag-torque control is adapted to an instantaneous driving situation and roadway condition, so that skidding of the drive wheel owing to a drag torque is prevented, and wherein with a vehicle sensor system, as a function of a wheel speed and a vehicle longitudinal acceleration, an actual engine drag torque is monitored, wherein a slip model is used to determine whether one of the drive wheels is skidding, wherein an engine drag-torque control is carried out, where the maximum permissible engine drag torque is predetermined. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A device for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position to generate a drive torque, comprising:
a control unit configured to perform the following; carrying out, at the motor vehicle, an engine drag-torque control to avoid skidding of the drive wheel when the accelerator pedal arrives back in a neutral position, wherein a wheel slip is determined at another vehicle, which has an electronic stability program, based on the speeds of the wheels of the another vehicle, wherein, via a control unit of the another vehicle, an effective coefficient of friction of a roadway from the wheel slip is determined, wherein a present position of the another vehicle on the roadway is continuously determined through a satellite-based navigation system of the another vehicle, wherein the effective coefficient of friction of the another vehicle on the roadway is transmitted to a central database, where the effective coefficient of friction of the another vehicle is stored together with the present position of the another vehicle; and specifying a maximum permissible engine drag torque to the engine drag-torque control as a function of a currently effective coefficient of friction, received from the central database and as determined by the another vehicle and stored in the central database, of a road surface that is determined as a function of a present position of the motor vehicle; wherein the engine drag-torque control is adapted to an instantaneous driving situation and roadway condition, so that skidding of the drive wheel owing to a drag torque is prevented, and wherein with a vehicle sensor system, as a function of a wheel speed and a vehicle longitudinal acceleration, an actual engine drag torque is monitored, wherein a slip model is used to determine whether one of the drive wheels is skidding, wherein an engine drag-torque control is carried out, where the maximum permissible engine drag torque is predetermined. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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24. A device for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position to generate a drive torque, comprising:
a control unit configured to perform the following; carrying out, at the motor vehicle, an engine drag-torque control to avoid skidding of the drive wheel when the accelerator pedal arrives back in a neutral position, wherein a wheel slip is determined at another vehicle, which has an electronic stability program, based on the speeds of the wheels of the another vehicle, wherein, via a control unit of the another vehicle, an effective coefficient of friction of a roadway from the wheel slip is determined, wherein a present position of the another vehicle on the roadway is continuously determined through a satellite-based navigation system of the another vehicle, wherein the effective coefficient of friction of the another vehicle on the roadway is transmitted to a central database, where the effective coefficient of friction of the another vehicle is stored together with the present position of the another vehicle; and specifying a maximum permissible engine drag torque to the engine drag-torque control as a function of a currently effective coefficient of friction, received from the central database and as determined by the another vehicle and stored in the central database, of a road surface that is determined as a function of a present position of the motor vehicle; wherein the engine drag-torque control is adapted to an instantaneous driving situation and roadway condition, so that skidding of the drive wheel owing to a drag torque is prevented, wherein an activation threshold of the engine drag-torque control is adjusted as a function of a prevailing coefficient of friction, which is determined as a function of the present position of the motor vehicle and the data, stored in the database, which is updated by preceding motor vehicles, and wherein the activation threshold is reduced if the prevailing coefficient of friction drops below a specifiable threshold, so that the engine drag-torque control intervenes in the operation of the motor vehicle, and wherein if the coefficient of friction exceeds a specifiable threshold, then the activation threshold is raised, so that the driver of the motor vehicle is able to use the drag torque.
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25. A device for operating a motor vehicle that has at least one driving engine which is operatively connected to at least one drive wheel and is controlled as a function of an accelerator-pedal position to generate a drive torque, comprising:
a control unit configured to perform the following; carrying out, at the motor vehicle, an engine drag-torque control to avoid skidding of the drive wheel when the accelerator pedal arrives back in a neutral position, wherein a wheel slip is determined at another vehicle, which has an electronic stability program, based on the speeds of the wheels of the another vehicle, wherein, via a control unit of the another vehicle, an effective coefficient of friction of a roadway from the wheel slip is determined, wherein a present position of the another vehicle on the roadway is continuously determined through a satellite-based navigation system of the another vehicle, wherein the effective coefficient of friction of the another vehicle on the roadway is transmitted to a central database, where the effective coefficient of friction of the another vehicle is stored together with the present position of the another vehicle; and specifying a maximum permissible engine drag torque to the engine drag-torque control as a function of a currently effective coefficient of friction, received from the central database and as determined by the another vehicle and stored in the central database, of a road surface that is determined as a function of a present position of the motor vehicle; wherein the engine drag-torque control is adapted to an instantaneous driving situation and roadway condition, so that skidding of the drive wheel owing to a drag torque is prevented, and wherein an engine drag-torque precontrol does not make the maximum permissible engine drag torque available to the engine drag-torque control, but it is provided to an engine management program, so that an adjustment to the currently effective coefficient of friction is carried out not by the engine drag-torque control, but by the engine management program, which limits the maximum drag torque of the driving engine independently of the intervention of the engine drag-torque control.
Specification