Method and device for triggering an automatic emergency braking process of a vehicle

• US 20060097570A1
• Filed: 08/30/2003
• Published: 05/11/2006
• Est. Priority Date: 09/20/2002
• Status: Active Grant

• Current Assignee: Daimler AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler Chrysler Company LLC (Stellantis NV)
• Inventors: Voss, Ursula, Mendt, Wolfram, Scherhaufer, Ingo, Trost, Juergen, Gut, Matthias, Volk, Gert, Doerr, Heiko, Schaeffers, Lorenz
• Granted Patent: US 7,425,043 B2
• Time in Patent Office: Days
• US Class Current: 303/193
• CPC Class Codes: B60Q 1/44 for indicating braking action or preparation for braking, e.g. by detection of the foot approaching the brake pedal
• CPC Class Codes: B60Q 1/535 to prevent rear-end collisions, e.g. by indicating safety distance at the rear of the vehicle
• CPC Class Codes: B60Q 5/006 indicating risk of collision between vehicles or with pedestrians
• CPC Class Codes: B60Q 9/008 for anti-collision purposes
• CPC Class Codes: B60T 17/20 Safety devices operable by passengers other than the driver , e.g. for railway vehicles
• CPC Class Codes: B60T 2201/02 Active or adaptive cruise control system; Distance control
• CPC Class Codes: B60T 7/22 initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle , or by means of contactless obstacle detectors mounted on the vehicle
• CPC Class Codes: B60W 2050/143 Alarm means
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2710/18 Braking system
• CPC Class Codes: B60W 30/09 Taking automatic action to avoid collision, e.g. braking and steering

Abstract

The invention relates to a method and a device for triggering an automatic emergency braking process of a vehicle, in particular of a truck. Said device provides an assistance function for avoiding a rear end collision of the vehicle with a vehicle traveling in front and/or for reducing the consequences of an accident if a rear end collision is unavoidable, with a driver warning being triggered if a predefined warning condition (62) is fulfilled. The fulfillment of the warning condition (62) specifies that the automatic emergency braking process is to be triggered after the expiry of a predefined warning time period (t_w=t_oa+t_h) in order to avoid the vehicle having a rear end collision with the vehicle traveling in front.

Claims

1-22. -22. (canceled)

23. A method for triggering automatic emergency braking in a first vehicle to avoid, or mitigate the effect of, a rear end collision with a second vehicle traveling ahead of the first vehicle, said method comprising:

determining an instantaneous driving situation of the first vehicle, based on a registered acceleration of the first vehicle and on a predefined emergency braking deceleration;

triggering a driver warning if at least one predefined warning condition is fulfilled; and

triggering an automatic emergency braking after the driver warning has been triggered;

wherein,

fulfillment of the warning condition requires that, based on an instantaneous situation of the first vehicle, an automatic emergency braking process is to be triggered;

the warning condition includes, as target conditions, a predefined target safety distance and a predefined target relative speed between the first and second vehicles, which are to be attained after the automatic emergency braking process is completed;

in determining the instantaneous driving situation of the first vehicle, in addition to the registered acceleration of the first vehicle, a registered current relative acceleration between the first and second vehicles is also taken into account. and

the triggering of an automatic emergency braking is delayed until expiration of a predefined warning time period after the driver warning has been triggered.

24. The method as claimed in claim 23, wherein the driver warning includes at least one of visual, acoustic, and haptic signals.

25. The method as claimed in claim 24, wherein:

a driver warning which can be perceived haptically by the driver of the vehicle comprises a partial braking process of the vehicle with a predefined partial braking deceleration; and

the predefined partial braking deceleration is smaller than the predefined emergency braking deceleration.

26. The method as claimed in claim 25, wherein the automatic emergency braking process is triggered only if a given emergency braking condition is fulfilled and the predefined warning time period has expired.

27. The method as claimed in claim 26, wherein the emergency braking deceleration is predefined in a permanent or adjustable fashion.

28. The method as claimed in claim 27, wherein the warning time period is predefined in a permanent or adjustable fashion.

29. The method as claimed in claim 28, wherein the target relative speed is predefined in a permanent or adjustable fashion.

30. The method as claimed in claim 29, wherein the a permanently predefined target relative speed between the vehicle and vehicle traveling in front has a value of approximately zero.

31. The method as claimed in claim 30, wherein the target safety distance is predefined in a permanent or adjustable fashion.

32. The method as claimed in claim 31, wherein, when it is determined that the driver is attentive, or that the risk of a rear end collision is reduced, the driver warning is not triggered.

33. The method as claimed in claim 32, wherein, when the driver is attentive or the risk of a rear end collision is reduced, a driver warning which has already been triggered is terminated or changed, or the automatic emergency braking process is not triggered.

34. The method as claimed in claim 33, wherein the automatic emergency braking process is triggered automatically when the predefined warning time period expires if the driver warning is not aborted during the predefined warning time period.

35. The method as claimed in claim 34, wherein an automatic emergency braking process which has already been triggered is aborted if a detected emergency braking time period or the predefined target relative speed and the predefined target safety distance are attained.

36. The method as claimed in claim 35, wherein:

the driver warning comprises at least two warning stages which are triggered in chronological succession within the predefined warning time period of the driver warning; and

each warning stage is assigned a predefined warning stage time period.

37. The method as claimed in claim 36, wherein the warning stage time period is predefined in a permanent or adjustable fashion.

38. The method as claimed in claim 37, wherein, after a first warning stage has been triggered, at least one further warning stage is triggered only if a predefined warning stage condition assigned to the further warning stage is fulfilled.

39. The method as claimed in claim 38, wherein, when the driver is attentive or when the risk of a rear end collision is reduced, at least one of the warning stages which has already been triggered is terminated or further warning stages are prevented.

40. The method as claimed in claim 39, wherein attentiveness of the driver is detected on the basis of an activation of at least one operator control element which controls longitudinal or lateral dynamics of the vehicle.

41. The method as claimed in claim 40, wherein a reduction in the risk of a rear end collision is detected by reference to at least one of an increasing distance between the first and second vehicles and a decreasing relative speed between the first and second vehicles.

42. The method as claimed in claim 41, wherein the instantaneous driving situation of the first vehicle is determined as a function of at least one of the detected distance between the first and second vehicle, the detected relative speed between the first and second vehicles, detected speed of the first vehicle, detected relative acceleration between the first and second vehicles, detected acceleration of the first vehicle, inclination of a roadway on which the first vehicle travels, and coefficients of friction between the roadway and wheels of the vehicle.

43. The method as claimed in claim 42, wherein, when automatic emergency braking is triggered, a warning is issued to vehicles traveling in front or behind.

44. Apparatus for carrying out automatic emergency braking in a first vehicle to avoid, or mitigate the effects of, a rear end collision with a second vehicle traveling ahead of the first vehicle, said apparatus comprising an evaluation unit which triggers a driver warning when at least one predefined warning condition stored in the evaluation unit is fulfilled;

wherein;

the evaluation unit determines an instantaneous driving situation of the first vehicle, based on a registered acceleration of the first vehicle, and on a predefined emergency braking deceleration;

fulfillment of the warning condition requires that, based on the instantaneous driving situation of the first vehicle, an automatic emergency braking process is to be triggered by suitable actuation of braking means of the vehicle;

the warning condition includes, as target conditions, a predefined target safety distance and a predefined target relative speed between the first and second vehicles, which are to be attained when the automatic emergency braking process is completed;

in determining the instantaneous driving situation of the first vehicle, in addition to the registered acceleration of the first vehicle, a registered current relative acceleration between the first and second vehicles is taken into account;

an automatic emergency braking process is triggered only after the driver warning has been triggered and a predefined warning time period has expired thereafter.