Method and device for limiting the driving speed of a motor vehicle

• US 7,509,193 B2
• Filed: 11/26/2002
• Issued: 03/24/2009
• Est. Priority Date: 06/15/2002
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kustosch, Mario
• Primary Examiner(s): Tran; Dalena
• Assistant Examiner(s): Jen; Ian
• Application Number:
  US10/517,159
• Publication Number:
  US 20060100755A1
• Time in Patent Office: 2,310 Days
• Field of Search: 701/93, 701/22, 701/123, 701 52- 56, 477/121, 477/111, 477/902, 477/64, 477/102, 477107-110, 477/156, 123/333, 123/397, 123/399, 324/428, 320/48
• US Class Current: 701/22
• CPC Class Codes: B60K 31/04 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of an electrical signal which is fed into the controlling means
• CPC Class Codes: B60L 2240/441 Speed
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 2240/486 Operating parameters
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2530/16 Driving resistance
• CPC Class Codes: B60W 2540/106 Rate of change
• CPC Class Codes: B60W 2710/1061 Output power
• CPC Class Codes: B60W 30/146 Speed limiting
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration
• CPC Class Codes: Y10S 477/902 Control signal is engine parameter other than manifold pressure or fuel control

Abstract

A method and a device are provided for limiting the driving speed of a motor vehicle that allow a selectable, fixed fuel consumption per distance traveled to be maintained without limiting short-term acceleration. In this context, the driving speed is limited to a maximum value (vmaxbe), at which a predefined maximum fuel consumption (Besetpoint) for steady driving speed is not exceeded.

Claims

1. A method for limiting a driving speed of a motor vehicle, comprising:

limiting the driving speed to a predefined maximum value, the maximum value corresponding to a predefined maximum fuel consumption for a steady driving speed;

wherein;

the maximum value for the driving speed is determined from a maximum drive power of the vehicle derived from a relationship between the predefined maximum fuel consumption and a specific fuel consumption of the engine of the vehicle at an instantaneous operating point, based on an inverse characteristic curve for a speed-dependent proportion of a total driving resistance;

the maximum drive power of the vehicle is adjusted using a speed-independent proportion of the total driving resistance; and

the speed-independent proportion of the total driving resistance is determined by subtracting the speed-dependent proportion of the total driving resistance and an inertial force of the vehicle from an instantaneous drive power of the vehicle.

2. The method of claim 1, wherein the speed-independent proportion of the total driving resistance is filtered using a first order low pass filter.

3. The method of claim 1, wherein the instantaneous drive power is determined using an actual engine torque, a wheel radius, and a transmission ratio factor.

4. The method of claim 1, wherein the specific fuel consumption is determined from a characteristic map as a function of an engine speed and an actual engine torque.

5. The method of claim 1, wherein the driving speed is limited as a function of the predefined maximum fuel consumption only when one of:

a) the gradient of a driving pedal position is less than a predefined value; and

b) a kick-down function is deactivated.

6. A device for limiting a driving speed of a motor vehicle, comprising:

an arrangement for determining a maximum fuel consumption for a steady driving speed;

an arrangement for limiting the driving speed to a maximum value corresponding to the determined maximum fuel consumption; and

wherein;

the maximum value for the driving speed is determined from a maximum drive power of the vehicle derived from a relationship between the predefined maximum fuel consumption and a specific fuel consumption of the engine of the vehicle at an instantaneous operating point, based on an inverse characteristic curve for a speed-dependent proportion of a total driving resistance;

the maximum drive power of the vehicle is adjusted using a speed-independent proportion of the total driving resistance; and

the speed-independent proportion of the total driving resistance is determined by subtracting the speed-dependent proportion of the total driving resistance and an inertial force of the vehicle from an instantaneous drive power of the vehicle.

7. The device of claim 6, wherein the speed-independent proportion of the total driving resistance is filtered using a first order low pass filter.

8. The device of claim 6, further comprising:

an arrangement that determines the instantaneous drive power using an actual engine torque, a wheel radius, and a transmission ratio factor.

9. The device of claim 6, further comprising:

an arrangement that determines the specific fuel consumption is determined from a characteristic map as a function of an engine speed and an actual engine torque.

10. The device of claim 6, wherein the driving speed is limited as a function of the predefined maximum fuel consumption only when one of:

a) the gradient of a driving pedal position is less than a predefined value; and

b) a kick-down function is deactivated.