Speed control system and method for a motor vehicle

• US 20070021898A1
• Filed: 09/27/2006
• Published: 01/25/2007
• Est. Priority Date: 04/03/2004
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Proemm, Uwe
• Granted Patent: US 7,743,866 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• CPC Class Codes: B60W 2710/0666 Engine torque
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle

Abstract

A speed control system is provided for a motor vehicle, including units for calculating a drive torque or a brake torque as a function of a pre-definable target speed, the target speed being pre-defined by the single actuation of an operable control element. A sustained actuation of the control element is used to pre-define a target acceleration, instead of a target speed. The drive torque or brake torque are calculated from the target acceleration.

Claims

1. Speed control system for a motor vehicle, comprising:

a unit for calculating a drive torque or brake torque as a function of a pre-definable target speed, the target speed being pre-defined by a single actuation of an operable control element; and

wherein a sustained actuation (db) of the control element (BE) pre-defines a target acceleration (as), instead of a target speed (vs), the unit calculating the drive torque (Ma) or brake torque (Mb) from the target acceleration.

2. The speed control system, as claimed in claim 1, wherein, upon releasing the control element (BE) from the sustained actuation (db), a current speed (va) or a speed (va-k), which deviates by a pre-defined value (K) from the current speed (va), is pre-defined as the target speed (vs).

3. The speed control system, as claimed in claim 1, wherein the target acceleration (as) is pre-defined as a function of at least one parameter (va).

4. The speed control system, as claimed in claim 1, wherein the calculation of the drive torque (Ma) or the brake torque (Mb) takes into consideration load resistances (L) of the vehicle (F).

5. The speed control system, as claimed in claim 2, wherein the calculation of the drive torque (Ma) or the brake torque (Mb) takes into consideration load resistances (L) of the vehicle (F).

6. The speed control system, as claimed in claim 1, wherein the control element (BE) is operable on several control levels, and further wherein a sustained actuation (db) pre-defines a control level-specific target acceleration (as).

7. A method of operating a speed control system of a motor vehicle, the method comprising the acts of:

pre-defining a target speed of the vehicle via a single actuation of an operable control element;

pre-defining a target acceleration, instead of the target speed, by a sustained actuation of the control element; and

calculating one of a drive torque or brake torque as a function of the target acceleration.

8. The method according to claim 7, further comprising the act of pre-defining a current speed or a speed which deviates by a pre-defined value from the current speed, as the target speed upon releasing the control element from the sustained actuation.

9. The method according to claim 7, wherein the act of pre-defining the target acceleration is carried out as a function of at least one parameter of the vehicle.

10. The method according to claim 7, wherein the act of calculating the drive torque or the brake torque factors into consideration a load resistance of the vehicle.

11. The method according to claim 7, further comprising the act of operating the control element on several control levels, wherein the sustained actuation pre-defines a control level-specific target acceleration.