Method for triggering autonomous emergency braking processes in a vehicle fleet
阅读说明:本技术 用于在车队中触发自主紧急制动过程的方法 (Method for triggering autonomous emergency braking processes in a vehicle fleet ) 是由 F·黑克尔 U·古克尔 A·穆斯塔法 于 2018-12-06 设计创作,主要内容包括:本发明涉及一种用于触发在至少一个后方跟随车辆(60至120)前面行驶的车辆(40)的自主紧急制动过程以避免该前方行驶车辆(40)撞上障碍物(20)的方法,其中,a)如果满足至少一个警告条件,则在该前方行驶车辆(40)中触发驾驶员警告,其中,b)满足警告条件表明,由于该前方行驶车辆(40)相对于所述障碍物(20)的瞬时行驶状况,触发自主紧急制动过程,其中c)在所述前方行驶车辆(40)中的自主紧急制动过程仅在触发驾驶员警告并且接下来警告时长(tWarning)期满之后才触发,其中d)所述警告时长(tWarning)作为总警告时长包含第一警告时长(tWarningSignal)和第二警告时长(tPartialBrk),其中,e)在所述第一警告时长(tWarningSignal)期间输出光学的和/或声学的警告信号,并且在紧接着所述第一警告时长(tWarningSignal)的第二警告时长(tPartialBrk)的范畴内,实施所述前方行驶车辆(40)的具有部分制动减速度的部分制动,该部分制动减速度小于在所述前方行驶车辆(40)的自主紧急制动过程中作用的紧急制动减速度,其特征在于,f)在仍处于未制动状态下的至少一个后方跟随车辆(60至120)中,最早在第一时间点(t<Sub>1</Sub>)并且最晚在第二时间点(t<Sub>2</Sub>)采取自主制动,在该第一时间点,所述前方行驶车辆(40)中的第一警告时长(tWarningSignal)开始,在所述第二时间点,所述前方行驶车辆(40)中的第一警告时长(tWarningSignal)结束。(The invention relates toMethod for triggering an autonomous emergency braking process of a vehicle (40) traveling in front of at least one rear following vehicle (60 to 120) in order to avoid the front traveling vehicle (40) from colliding with an obstacle (20), wherein a) a driver warning is triggered in the front traveling vehicle (40) if at least one warning condition is fulfilled, wherein b) the fulfillment of a warning condition indicates that an autonomous emergency braking process is triggered due to an instantaneous traveling condition of the front traveling vehicle (40) relative to the obstacle (20), wherein c) an autonomous emergency braking process in the front traveling vehicle (40) is triggered only after triggering a driver warning and the following expiration of a warning duration (tWarng), wherein d) the warning duration (tWarng) comprises as a total warning duration a first warning duration (tWarnNGSignal) and a second warning duration (tPartialk), wherein e) an optical and/or acoustic warning signal is output during the first warning period (tWarngSignal) and partial braking of the vehicle (40) in front is carried out within the scope of a second warning period (tPartialBrk) following the first warning period (tWarngSignal), with a partial braking deceleration which is smaller than the emergency braking deceleration acting during autonomous emergency braking of the vehicle (40) in front, characterized in that f) in at least one following vehicle (60 to 120) still in the unbraked state, at the earliest at least one time point (t) in the first time point (t) 1 ) And at the latest at a second point in time (t) 2 ) Autonomous braking is used, a first warning period (tWarngSignal) in the vehicle (40) traveling ahead being started at the first point in time, and the first warning period (tWarngSignal) in the vehicle (40) traveling ahead being ended at the second point in time.)
1. A method for triggering an autonomous emergency braking process of a vehicle (40) traveling in front of at least one rear following vehicle (60 to 120) in order to avoid the front traveling vehicle (40) from hitting an obstacle (20),
a) triggering a driver warning in the forward moving vehicle (40) if at least one warning condition is fulfilled, wherein,
b) the satisfaction of the warning condition indicates that an autonomous emergency braking process is to be triggered as a result of a momentary driving situation of the vehicle (40) driving in front relative to the obstacle (20), wherein
c) An autonomous emergency braking process in the vehicle (40) travelling ahead is triggered only after triggering a driver warning and the following expiration of a warning duration (tWarng), wherein
d) The warning duration (tWarng) comprises, as a total warning duration, a first warning duration (tWarngSignal) and a second warning duration (tPartialBrk), wherein,
e) outputting an optical and/or acoustic warning signal during the first warning period (tWarngSignal) and carrying out a partial braking of the vehicle (40) moving in front with a partial braking deceleration which is smaller than an emergency braking deceleration acting during the autonomous emergency braking of the vehicle (40) moving in front within the scope of a second warning period (tPartialBrk) following the first warning period (tWarngSignal), characterized in that the first warning period (tWarngSignal) is set as a warning period (tWarngSignal),
f) for the at least one rear following vehicle (60 to 120) still in the unbraked state, earliest at a first point in time (t)1) And at the latest at a second point in time (t)2) Autonomous braking is used, a first warning period (tWarngSignal) in the vehicle (40) traveling ahead being started at the first point in time, and the first warning period (tWarngSignal) in the vehicle (40) traveling ahead being ended at the second point in time.
2. Method according to claim 1, characterized in that for the at least one rear following vehicle (60) partial braking with a partial braking deceleration is taken as autonomous braking, which partial braking deceleration is smaller than the maximum possible emergency braking deceleration of the at least one rear following vehicle (60).
3. Method according to any one of the preceding claims, characterized in that for the at least one rear following vehicle (60) the autonomous braking that has been applied is interrupted as the first warning period (tWarnNGSignal) in the front running vehicle (40) expires.
4. The method according to one of the preceding claims, characterized in that the beginning or the first point in time of the first warning period (tWarnNGSignal) in the preceding vehicle (40) and/or the expiration or the second point in time of the first warning period (tWarnNGSignal) in the preceding vehicle (40) is transmitted from the preceding vehicle (40) to the at least one following vehicle (60 to 120) by means of a vehicle-to-vehicle communication.
5. Method according to one of the preceding claims, characterized in that the vehicle (40) running ahead and the at least one following vehicle (60 to 120) together form an uncoupled or electronically coupled vehicle platoon (10), and in that the vehicles (40 to 120) of the vehicle platoon (10) are moved at least temporarily at a predeterminable, constant longitudinal distance (d) from one another along the travel path on the basis of a predeterminable overall operating strategy assigned to the vehicle platoon (10).
6. The method according to claim 5, characterized by uncoupling the electronic coupling of the vehicles (40 to 120) of the platoon (10) when the first warning duration (tWarnNGSignal) in the preceding vehicle (40) expires and autonomous braking has been assumed in the at least one following vehicle (60 to 120).
7. The method according to claim 5 or 6, characterized in that the vehicle (40) travelling ahead is a lead vehicle of the platoon (10) or a vehicle (60 to 120) within the platoon (10).
8. Method according to claim 7, characterized in that the obstacle (20) is constituted by an object or vehicle, stationary or movable, which is located in front of a lead vehicle (40) of the platoon (10) seen in the driving direction of the platoon (10), or by an object or vehicle entering the platoon (10) in front of the vehicle (40) driving in front.
9. Method according to any one of the preceding claims, characterized in that for the vehicle (40) travelling in front the warning period (tWarnng) is adjusted in relation to a relative movement situation between the vehicle travelling in front and the obstacle (20) and/or is adapted in relation to a time-varying relative movement situation between the vehicle (40) travelling in front and the obstacle (20).
10. Method according to claim 9, characterized in that for the relative movement situation between the vehicle (40) travelling in front and the obstacle (20) at least one of the following parameters is taken into account: -the speed and/or acceleration of the vehicle (40) travelling in front in the direction of travel and/or transversely to the direction of travel; -the speed and/or acceleration of the obstacle (20) in and/or transverse to the direction of travel; a relative speed and/or a relative acceleration between the vehicle (40) travelling in front and the obstacle (20) in the direction of travel and/or transversely to the direction of travel; a distance between the preceding vehicle (40) and the obstacle (20).
11. Method according to any of the preceding claims, characterized in that if the driver of the preceding vehicle (40) triggers braking of the preceding vehicle (40) within the warning period (tWarnng), an autonomous partial braking and/or an autonomous emergency braking process is not triggered.
12. A loosely coupled or uncoupled vehicle platoon (10) consisting of a vehicle travelling ahead (40) and at least one vehicle (60 to 120) following the vehicle travelling ahead, wherein the vehicle platoon is controlled according to the method of any of the preceding claims.
Technical Field
The invention relates to a method for triggering an autonomous emergency braking process in a vehicle traveling behind a following vehicle in front of the vehicle in order to avoid a collision of the vehicle traveling in front with an obstacle according to the preamble of claim 1.
The invention also relates to a loosely coupled or uncoupled vehicle fleet composed of a vehicle traveling ahead and at least one vehicle following the vehicle traveling ahead, wherein the vehicle fleet is controlled according to this method, according to claim 12.
Background
This method describes an emergency braking assistance (advanced emergency braking system, AEBS), in which an obstacle in front of the vehicle is detected by means of a radar sensor, a camera and/or a laser, and the driver is warned in the event of a collision with the obstacle. If the driver does not react to the warning, the emergency braking assistance triggers emergency braking, so that no collision occurs. If a collision is unavoidable, the emergency braking assistance reduces at least the intensity of the collision and thus also the risk of injury to the occupants of the participating vehicles.
A method of this type is known from DE 102015104547 a 1. There, the autonomous emergency braking process is triggered after the expiration of a warning period during which the driver is informed of the following possibilities: by intervening in the form of a driver braking request, an autonomous emergency braking process is avoided. The warning period is divided in time into two phases, wherein during the first warning period an optical and/or acoustic driver warning is emitted. If the driver does not react to this, at the beginning of the second warning period, partial braking with a partial braking deceleration which is less than the predefined (maximum) emergency braking deceleration is undertaken. The emergency braking process is automatically triggered only if the driver also allows the second warning period to elapse without he actuating the brake. Thus, the driver has the opportunity to avoid a dangerous situation by actuating the brake, within the scope of the overall warning duration.
Furthermore, the driving of the vehicle following the lead vehicle can be automated by means of the driving assistance systems already present in modern motor vehicles to the extent that the vehicles are loosely or electronically coupled within the vehicle fleet. Thus, the vehicle driver of a motor vehicle following a lead vehicle does not have to monitor the traffic regulation by himself during the driving of the platoon. Such a loosely coupled platoon comprises at least a first lead vehicle and a last vehicle, and possibly intermediate vehicles. It is therefore known to couple vehicles electronically, to be able to drive them one after the other as closely as possible with longitudinal and transverse adjustment. In this case, the respective following vehicle is oriented, for example, optically forward. Motor vehicles are also equipped, for example, with sensors for blind spot monitoring and rear area monitoring and sensors for lane orientation, and at least with means for vehicle-to-vehicle communication. Such loosely coupled vehicle associations or fleets of motor vehicles are commonly referred to in the literature as "flees".
The motor vehicles are electronically coupled to a vehicle fleet via a corresponding driver assistance system for automatic distance maintenance (also referred to as ACC system — adaptive cruise control). For this purpose, the real-time distance to the vehicle driving in front can be determined by sensors in the vehicle driving in the rear and adjusted to a predefined setpoint value, for example 8 meters. For example, radar sensors or lidar sensors may be used for distance measurement.
In tight fleet driving during driving in excess of about 80km/h, the air resistance of the fleet vehicles is reduced by up to 30%. In this case, the distance between the vehicle travelling in front and the vehicle following behind is in the range from 8 m to 20 m, which contributes to a significant reduction in the air resistance. The smaller the distance between the participating vehicles, the smaller the air resistance of the individual vehicle. In order to significantly reduce the air resistance, a higher demand is placed on the driving assistance system for automatic distance maintenance due to the smaller distance.
Exemplary methods for electronically coupling motor vehicles to a fleet of vehicles by means of driver assistance systems are described in DE 102007046765 a1 or EP 1569183 a 2.
The following requirements are particularly imposed on the control and regulation of the vehicle fleet:
the participating vehicles comply with a defined tolerance with respect to each other at a short longitudinal distance (for example 8 to 20 meters).
The following vehicle is automatically guided laterally in the lane of the lead vehicle as accurately as possible.
The stability of the vehicle fleet is ensured, i.e. in particular the "accordion effect" (chain stability — queue stability) is avoided, which not only leads to increased consumption, but also significantly increases the risk of collision accidents. The longitudinal guidance and the transverse guidance comply with the chain stability.
Small variations in the speed of vehicles traveling in front of the fleet cannot be implemented intensively by following vehicles behind.
For guidance in the transverse direction, no cornering and thus no lane departure in the rear-following vehicle is permitted.
In the event of a strong braking of the lead vehicle, the following vehicle has a sufficiently fast braking response to avoid a rear-end collision.
Compliance with the above requirements is often made difficult by the differences in technical equipment and characteristics of the vehicles participating in the fleet, such as engine power, available power for the downhill creep brakes or service brakes, vehicle configuration, load conditions and tire characteristics.
For example, if an obstacle suddenly appears in front of the first lead vehicle of the fleet, which may force emergency braking at the maximum possible deceleration, either by the driver of the first lead vehicle or by the automatic drive of the vehicle.
Because of the fact that the first lead vehicle can be braked with its maximum available deceleration in order to keep the risk of collision with an obstacle or the collision speed as low as possible. However, there is thus a risk of: if the vehicles are located in a fleet of vehicles, a collision may occur with a vehicle within the fleet that is capable of applying a smaller maximum deceleration than the first lead vehicle, for example, due to a weaker brake or a higher load.
Thus, in order that the following vehicles do not collide successively, the first lead vehicle can be braked with the maximum deceleration of the vehicle in the fleet which brakes the weakest. However, this can result in the first lead vehicle braking with a smaller, i.e. relatively smaller, maximum deceleration of the participant who is "weakest" in terms of braking, as determined by the participant who is "weakest" in terms of braking. Therefore, in this case, the collision risk or collision speed with the obstacle increases.
Disclosure of Invention
In contrast, the object of the invention is to improve a method of this type with regard to a lower risk of collision. In addition, the loosely coupled or uncoupled vehicle fleets should be further expanded in such a way that they are operated in this way.
According to the invention, this object is achieved by the features of claims 1 and 12. Advantageous embodiments of the invention are the subject matter of the dependent claims.
The invention is based on a method for triggering an autonomous emergency braking process in at least one vehicle traveling behind a following vehicle in front of the vehicle in order to avoid collision of the vehicle traveling in front with an obstacle, wherein
a) Triggering a driver warning in a forward-driving vehicle when at least one warning condition is fulfilled, wherein
b) Satisfaction of the warning condition indicates that an autonomous emergency braking process is triggered as a result of a momentary driving situation of the vehicle driving in front relative to the obstacle, wherein
c) Autonomous emergency braking process in a vehicle travelling ahead is triggered after triggering a driver warning and the following expiration of a warning period, wherein
d) The warning duration as a total warning duration includes a first warning duration and a second warning duration, wherein
e) An optical and/or acoustic warning signal is output during a first warning period, and partial braking of the vehicle traveling ahead is carried out with a partial braking deceleration which is less than an emergency braking deceleration acting during autonomous emergency braking of the vehicle traveling ahead, within the scope of a second warning period following the first warning period.
An obstacle is understood here to mean either a stationary obstacle, a vehicle traveling ahead or in the lane of the relevant vehicle and an obstacle in the form of a vehicle which is present in front of the relevant vehicle, or a vehicle which passes through the lane of the relevant vehicle at any angle.
According to the invention it is provided that,
f) for at least one rear following vehicle still in the unbraked state, autonomous braking is assumed earliest at a first point in time at which a first warning period in the front running vehicle starts and latest at a second point in time at which the first warning period in the front running vehicle ends.
By "using autonomous braking" is understood that not only is an air gap of a brake actuator of the at least one following vehicle overcome, but that an effective braking force is built up in the brake actuator, which braking force can decelerate the at least one following vehicle. Thus, assuming braking includes establishing a braking force simultaneously or subsequently. It is obvious here that there is a very short time delay between the signal for taking the brake and the brake force acting in the brake actuator.
Thus, the point in time at which braking is assumed in at least one rear following vehicle still in the unbraked state lies within a time range from a first point in time at which the first warning period in the vehicle traveling ahead starts to a second point in time at which the first warning period in the vehicle traveling ahead starts.
The following vehicle can be a vehicle which directly follows the vehicle which is driving ahead or at least one vehicle which indirectly follows the vehicle which is driving ahead, wherein there can also be at least one further vehicle between the vehicle which is driving ahead and the at least one following vehicle.
Further, of course, there may be a plurality of following vehicles following the preceding vehicle, and braking may be synchronously performed at the first time point and at the second time point at the earliest and at the latest in these following vehicles.
Preferably, in at least one following vehicle still in the unbraked state, autonomous braking is assumed (approximately) at or shortly after a first point in time, at which a first warning period in the vehicle travelling ahead begins, but at a second point in time, at which the first warning period in the vehicle travelling ahead ends. In other words, the autonomous braking has been triggered or performed in the at least one rear following vehicle just starting at the first warning period in the front-running vehicle. During the first warning period, no partial braking has yet been undertaken in the vehicle travelling in front, but an optical and/or acoustic warning signal is output to the driver of the vehicle travelling in front, with which he arranges for the brakes to be actuated and thus brakes with partial braking and/or avoids an autonomous emergency braking process.
Thus, the braking has been applied in advance in at least one rear following vehicle, while a first warning period, during which the driver of the vehicle driving in front schedules the braking triggered by him, has just started or has started in the vehicle driving in front, but has not yet expired. This has the positive effect that, for example, the signal propagation time and the reaction time which are always present in the active vehicle tracking control between the vehicle driving ahead and the at least one following vehicle can be compensated, which reduces the risk of a collision between the vehicle driving ahead and the at least one following vehicle. The following possibilities exist due to the present invention: the partial braking carried out in the context of emergency braking Assistance (AEBS) and/or the emergency braking during emergency braking are also carried out at a higher deceleration in each case, which reduces the risk of a collision between the vehicle travelling ahead and an obstacle.
Advantageous embodiments and improvements of the invention are possible by means of the measures listed in the dependent claims.
For example, in the method, partial braking with a partial braking deceleration, which is smaller than the maximum possible emergency braking deceleration of the following vehicle, is assumed as autonomous braking in the at least one following vehicle.
Furthermore, in the at least one rear following vehicle, the autonomous braking (already) undertaken is interrupted at the expiration of the first warning period in the front driving vehicle.
According to one embodiment, the beginning of the first warning period in the preceding vehicle and/or the expiration of the first warning period in the preceding vehicle can be communicated from the preceding vehicle to the at least one following vehicle by means of a vehicle-to-vehicle communication.
In particular, it is preferred that at least one vehicle traveling ahead and at least one following vehicle, together with optionally further vehicles, form an uncoupled vehicle fleet or an electronically coupled vehicle fleet, wherein the vehicles of the vehicle fleet move at least temporarily at a predeterminable, constant longitudinal distance from one another along the travel path on the basis of a predeterminable overall operating strategy assigned to the vehicle.
For example, if a first warning duration expires in a vehicle driving ahead and if autonomous braking has been assumed in at least one following vehicle, the electronic coupling of the vehicles of the fleet is decoupled. If there is an indication that there is a risk of a collision of the vehicle travelling in front with an obstacle due to the first warning period in the vehicle travelling in front, the longitudinal distance between the vehicles of the platoon adjusted to be relatively small by the vehicle tracking adjustment represents a risk of a collision between the vehicles of the platoon. After the fleet dissociates, the ACC systems present in the vehicles of the fleet may individually set a larger longitudinal distance to be observed than the longitudinal distance present while the fleet is traveling, so that after the fleet dissociates, the risk of collision between the vehicles participating in the (front) fleet is reduced.
In general, the vehicle traveling ahead may be a lead vehicle of a platoon or a vehicle within a platoon. In the first case, the obstacle is formed, for example, by an object or vehicle that is stationary or movable, which is located in front of the lead vehicle of the platoon, as seen in the driving direction of the platoon, and in the second case, for example, by an object or vehicle that enters the platoon in front of the forward driving vehicle.
Furthermore, for example, it is also possible to assume autonomous braking in each case only in one, more or all vehicles following the lead vehicle in a loosely coupled or electronically coupled or uncoupled fleet, at a first point in time at which a first warning duration in the lead vehicle begins. A vehicle fleet that is uncoupled is understood to be a union or fleet of vehicles in which no electronically coupled vehicles travel in succession and, for example, each comply with a minimum distance from one another via an onboard ACC system.
In particular, it is preferred that the warning duration is adjusted in relation to a relative movement situation between the vehicle travelling in front and the obstacle and/or adapted in relation to a time-varying relative movement situation between the vehicle travelling in front and the obstacle.
For example, if an obstacle, for example in the form of a vehicle travelling ahead, decelerates, the warning duration is shortened relative to a predefined or adjusted initial warning duration on the basis of the relative movement situation between the vehicle and the obstacle. Since, if an emergency braking process with a maximum emergency braking deceleration is carried out after the warning period has expired, a certain emergency braking delay time is required for this purpose in order to comply with the safety distance to the obstacle, in this case the driver is provided with less intervention time (warning period). If in this case the warning period is fixedly predefined independently of the relative movement situation, there is the danger that this first warning period is too long and the vehicle in question collides with an obstacle.
In contrast, for example, if an obstacle in the form of, for example, a preceding vehicle accelerates, the warning period may be extended. Because, in this case, the driver is given more time to actively intervene with the braking manoeuvre.
This results in a variable or dynamic warning duration which is better adapted to the respective traffic situation. Thus, advantageously, the warning duration is adapted to the current traffic situation of the vehicle in relation to the obstacle.
At least one of the following parameters may be taken into account in the relative movement state between the preceding vehicle and the obstacle. The speed and/or acceleration of the vehicle travelling in front in the direction of travel and/or transversely to the direction of travel, the speed and/or acceleration of the obstacle in the direction of travel and/or transversely to the direction of travel, the relative speed and/or relative acceleration of the vehicle travelling in front and the obstacle in the direction of travel and/or transversely to the direction of travel, the distance between the vehicle travelling in front and the obstacle.
Since the sensor data of the sensors monitoring the relative movement between the vehicle and the obstacle are usually evaluated in the evaluation device periodically, i.e. at defined time intervals, the warning duration is preferably also adjusted or adapted periodically.
Alternatively, it may also be provided that the autonomous partial braking and/or the autonomous emergency braking process is not triggered if the driver of the vehicle travelling ahead triggers braking of the vehicle travelling ahead within the warning period. Since the driver of the vehicle driving ahead is understood by triggering the braking by him via the brake pedal that he already takes charge of the situation and therefore does not have to trigger an autonomous partial braking and/or an autonomous emergency braking process. This configuration may also be coupled with a minimum deceleration condition that must be achieved by driver braking in the forward traveling vehicle.
Alternatively, the total warning period, the first warning period and/or the second warning period may also be preset to a fixed predefined value and then no longer be changed.
The invention also relates to a loosely coupled or electronically coupled or uncoupled vehicle fleet consisting of a vehicle travelling in front and at least one following vehicle, wherein the vehicle fleet is controlled according to the above method.
Drawings
The invention is explained in detail below with the aid of embodiments with reference to the drawings. The figures show:
fig. 1 is a schematic side view of a fleet of motor vehicles loosely coupled to each other;
FIG. 2 is a schematic flow chart of a preferred embodiment of the method according to the present invention;
fig. 3A plots the acceleration a and speed v of a vehicle traveling ahead of the fleet of fig. 1, as well as the distance d relative to the vehicle traveling ahead, versus the time t after the driver warning is output.
Fig. 3B depicts a schematic diagram of the speed v of a vehicle of the platoon of fig. 1 following a front running vehicle.
Detailed Description
In fig. 1 a schematic side view of a platoon 10 (platoon) of vehicles loosely or electronically coupled to each other is shown according to a preferred embodiment. The
In the exemplary embodiment,
The motor vehicles or
In addition, wireless vehicle-to-infrastructure communication devices can also be provided, which are installed, for example, in each of the motor vehicles or the
Each of the six
For each
Based on the distance and speed data received in each case from the electronic control unit of the vehicle tracking control, the electric steering, the electropneumatic braking and the electric drive of each
Furthermore, the
A method for moving a
The overall strategy is to be understood here to mean, in particular, a longitudinal adjustment of the
The method for triggering an autonomous emergency braking process in order to avoid a
a) Triggering a driver warning in the
b) The satisfaction of the warning condition indicates that an autonomous emergency braking process is to be triggered on the basis of the instantaneous driving situation of the
c) The autonomous emergency braking process in the preceding
d) The warning duration tWarng as the total warning duration comprises a first warning duration tWarngSignal and a second warning duration tPartialBrk, wherein
e) An optical and/or acoustic warning signal is output during a first warning period tWarngSignal, and partial braking of the
f) The
A preferred embodiment of the method will now be explained in detail with the aid of the flow chart shown in fig. 2 and in accordance with the illustrations of fig. 3A and 3B.
In this case, the following opportunities are indicated within the total warning period tWarning by the driver warning for the driver of the
First, the instantaneous driving situation of the vehicles driving in front of the
In addition, a partial braking deceleration a in the direction of travel x is determined, for example, from a memoryxvPartialBrakingAnd a safe distance d of the
Furthermore, based on the variables detected by the sensor device 2, a dynamic total warning time duration tWarnng and, for example, a dynamic second warning time duration tPartialBrk are determined from the previous behavior or movement of the
The dynamic total warning period tWarng indicates the total warning period during which the driver has time to intervene, while the dynamic second warning period tPartialBrk is the period during which the evaluation device 4 sends a signal to the brake device, not shown here, in order to trigger a partial brake in the
As can be seen from fig. 2, the second warning period tPartialBrk precedes in time the first warning period tWarningSignal, during which the driver is prompted by means of a signal device, not shown here, which is controlled by the evaluation device 4 by means of a corresponding electrical signal: braking should be performed actively.
If the driver brakes to a sufficient extent in the first warning period tWarnNGSignal, that is to say at least the safety distance d of the
The dynamic total warning duration tWarng is therefore composed of the first warning duration tWarnNGSignal and the dynamic second warning duration tPartialBrk. A timer integrated into the evaluation device monitors the expiration of the total warning period tWarng or the first warning period tWarnNGSignal or the second warning period tPartialBrk.
On the basis of the detected input variables, the evaluation device determines a collision avoidance deceleration aAvoid in order to achieve at least the necessary safety distance d of the
If the comparator 6 determines that the sought value of the collision avoidance deceleration aAvoid is less than or equal to the emergency braking deceleration axv emergency braking, no driver warning in combination with an automatic emergency braking process is triggered in the
Furthermore, the evaluation device 4 is designed to periodically or cyclically execute the above-mentioned steps: the parameters are detected, calculated, compared, etc., so that a corresponding collision monitoring takes place continuously in the active method or in the active device.
As described above, the total warning duration tWarning and/or the second warning duration tPartialBrk are dynamically adjusted in relation to the relative movement between the
The adjustment of the total warning duration tWarnng and/or the second warning duration tPartialbrk means that these variables are based on a comparison in the comparator 6 at the time of the determination: the collision avoidance deceleration aavooid is larger than the emergency braking deceleration axv emergency braking to adjust the relative movement condition between the
If, for example, the
If the
The values determined or adapted for the total warning time duration tWarnng and/or for the second warning time duration tPartialBrk at the point in time at which it is determined that the collision avoidance deceleration aAvoid is greater than the emergency braking deceleration axvEmergency Braking are, for example, held in the region of the phase immediately following the triggered driver warning.
According to an alternative embodiment, it can be provided that starting from the initial values of the total warning period tWarner and/or of the second warning period tPartialBrk, which are predefined at the time of triggering the driver warning or are adjusted only on the basis of the relative movement conditions existing between the
When, for example, for the case of deceleration of the
In fig. 3A, the distance (pitch) of the
Starting from the example of fig. 3A, at a first point in time t1First
According to the first time point t1The relative movement between the
If at the second point in time t2If, after the expiration of the first warning period tWarningSignal of-1.8 seconds, no braking intervention has been carried out on the part of the driver of the
Then, if at the third time point t3After the expiration of the second warning period tPartialBrk, no braking intervention has been carried out on the part of the driver of the
In the exemplary embodiment of the method explained with reference to fig. 2 and 3A, at a first point in time t at which it is determined that the collision avoidance deceleration aAvoid is greater than the emergency braking deceleration axv emergency braking1-3.0s, the determination corresponding to the first point in time t1Total warning duration tWarnig of relative movement conditions existing between the
Alternatively, it is possible to further decelerate or accelerate, for example, when the
At a first point in time t1In the
In this case, not only are air gaps of the brake actuators of the following
In other words, in this case, for example, if the first warning period tWarningSignal has just started or has started in the
Preferably, the first warning duration tWarningSignal is at a first time t1The start in the
Furthermore, it is preferred that, in the rear-following
This has a positive effect: possible signal propagation and reaction times that are always present in active vehicle following regulation, for example between the
For the sake of clarity, the speed of the
For example, if the first warning period tWarningSignal in the
However, the vehicle driving in front need not be the
Of course, the method is also not limited to the incorporation of a
Furthermore, instead of the description here, it is also possible for all
List of reference numerals
1 apparatus
2 sensor device
4 analysis and evaluation device
6 comparator
10 fleet of vehicles
20 obstacle
40 first lead vehicle
60 second vehicle
80 third vehicle
100 fourth vehicle
120 fifth vehicle