Method for operating a longitudinally guiding driver assist system and motor vehicle

• US 9,043,115 B2
• Filed: 05/24/2012
• Issued: 05/26/2015
• Est. Priority Date: 05/25/2011
• Status: Active Grant

• Current Assignee: Audi AG (Volkswagen AG)
• Original Assignee: Audi AG (Volkswagen AG)
• Inventors: Schuberth, Stefan, Held, Ralf
• Primary Examiner(s): Nguyen, John Q
• Assistant Examiner(s): WHALEN, MICHAEL F
• Application Number:
  US13/480,097
• Publication Number:
  US 20130138319A1
• Time in Patent Office: 1,097 Days
• Field of Search: 701/70, 701/93
• US Class Current: 701/93
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60K 31/0066 responsive to vehicle path curvature
• CPC Class Codes: B60W 2420/403 Image sensing, e.g. optical camera
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/14 Adaptive cruise control
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/146 Speed limiting
• CPC Class Codes: B60W 30/18145 Cornering

Abstract

In a method for operating a longitudinally guiding driver assist system of a motor vehicle, wherein a comfort curve speed is determined as a function of curve data, wherein the curve data are commensurate with at least one curve to be driven through next by the motor vehicle, wherein a target speed is determined as a function of the curve comfort speed at a defined point of the curve, and wherein the speed of the motor vehicle is adjusted as a function of at least the target speed of the motor vehicle.

Claims

1. A method for operating a longitudinally guiding driver assist system of a motor vehicle, comprising the steps of:

receiving curve data with a control device;

said curve data being commensurate with a curve negotiated next by the motor vehicle;

determining with the control device a comfort curve speed as a function of the curve data

determining with a calculation module a target speed to be reached by the motor vehicle at a defined point of the curve as a function of the comfort curve speed; and

adjusting the speed of the motor vehicle by taking at least the target speed into account,

wherein the comfort curve speed is selected as the target speed when the comfort curve speed is smaller than an actual speed of the motor vehicle by less than a predefined threshold value, and wherein the actual speed of the motor vehicle less the predefined threshold value is selected as target speed when the comfort curve speed is smaller than the actual speed by more than the predefined threshold value.

2. The method of claim 1, wherein the curve data are determined from road course data of a navigation device and/or from environmental data determined by at least one forward looking environmental sensor.

3. The method of claim 1, wherein the step of determining the comfort curve speed and the step of determining the target speed are carried out by a calculation module, said method further comprising:

outputting a first acceleration recommendation by the calculation module as a function of the target speed;

outputting a second acceleration recommendation by at least one other calculation module;

prioritizing among the first acceleration recommendation and the second acceleration recommendation;

selecting one of the first acceleration recommendation and the second acceleration recommendation as a function of said prioritizing; and

adjusting the speed of the motor vehicle as a function of the selected acceleration recommendation.

4. The method of claim 3, wherein the second acceleration recommendation is a function of a desired speed, said desired speed being selectable at a driver-side of the motor vehicle.

5. The method of claim 3, further comprising

outputting a third acceleration recommendation by a further calculation module as a function of a time gap to be maintained to another motor vehicle in front of the motor vehicle;

prioritizing among the first acceleration recommendation, the second acceleration recommendation and the third acceleration recommendation;

selecting one of the first acceleration recommendation, the second acceleration recommendation and the third acceleration recommendation as a function of said prioritizing;

adjusting the speed of the motor vehicle as a function of the selected acceleration recommendation.

6. The method of claim 3, wherein the selected acceleration recommendation is a minimal one of the acceleration recommendations.

7. The method of claim 1, wherein the comfort curve speed is determined as a function of a maximal curvature of the curve and/or as a function of a curvature at a defined point of the curve and a predefined comfort lateral acceleration.

8. The method of claim 1, wherein the target speed is determined as a function of a curvature of the curve at a first point of the curve.

9. The method of claim 1, wherein the comfort curve speed is selected as the target speed when the comfort curve speed is lower than an actual speed of the motor vehicle.

10. The method of claim 1, wherein an actual speed of the motor vehicle less a predetermined percentage of a difference between the actual speed and the comfort curve speed is selected as the target speed when the comfort curve speed is smaller than the actual speed of the motor vehicle.

11. The method of claim 1, wherein the comfort curve speed is select as the target speed when the comfort curve speed is smaller than an actual speed of the motor vehicle and greater than a predetermined threshold value, and wherein the predetermined threshold value is selected as target speed when the comfort curve speed is smaller than the predetermined threshold value.

12. The method of claim 11, wherein, when the comfort curve speed is not selected as the target speed, the actual speed of the motor vehicle is a speed of the motor vehicle at a beginning of an actual deceleration of the motor vehicle in response to the curve.

13. The method of claim 1, further comprising

determining a deceleration profile and a time point for applying the deceleration profile, said deceleration profile defining a deceleration phase;

and

initiating the deceleration phase at the time point to cause a deceleration of the motor vehicle to the target speed, said deceleration being commensurate with the deceleration profile, wherein the deceleration does not exceed a predefined maximal permitted deceleration.

14. The method of claim 13, wherein the deceleration is linearly increased to the maximal permitted deceleration, and wherein the deceleration phase is defined by at least two slopes of the deceleration profile, said at least two slopes being separated by a plateau, said plateau being a function of an operation of a motor brake of the motor vehicle.

15. The method of claim 14, wherein a tolerance time is taken into account for calculating the time point.

16. The method of claim 13, wherein the deceleration profile further defines an acceleration decrease phase and/or an acceleration limitation phase, wherein in the acceleration decrease phase a maximal possible acceleration request of the driver assist system is decreased to an intermediate acceleration, wherein the intermediate acceleration is constantly set in the acceleration limitation phase, and wherein the intermediate acceleration is set to zero at the beginning of the deceleration phase.

17. The method of claim 16, wherein the acceleration decrease phase and the acceleration limitation phase have a defined duration.

18. The method of claim 16, wherein the maximal possible acceleration request is linearly decreased to the intermediate deceleration.

19. The method of claim 16, wherein the intermediate acceleration is predefined.

20. The method of claim 16, wherein the intermediate acceleration is linearly decreased to zero at a beginning of the deceleration phase.

21. The method of claim 1, wherein the target speed is displayed to a driver of the motor vehicle.

22. The method of claim 1, wherein the target speed is displayed to a driver of the motor vehicle when the speed of the vehicle is adjusted as a function of the curve data.

23. The method of claim 22, wherein the target speed is displayed to the driver by backlighting a symbol.

24. A motor vehicle comprising:

a longitudinally guiding driver assist system, said longitudinally guiding driver assist system including a control device configured for implementing the method of claim 1.