EP4069557A1

EP4069557A1 - Method for coordinating vehicles of a group of vehicles during emergency braking, and control unit

Info

Publication number: EP4069557A1
Application number: EP20819665.9A
Authority: EP
Inventors: Richard MATTHAEI
Original assignee: ZF CV Systems Europe BV
Current assignee: ZF CV Systems Europe BV
Priority date: 2019-12-04
Filing date: 2020-12-01
Publication date: 2022-10-12
Also published as: CN114746314A; WO2021110637A1; US20220410923A1; DE102019132943A1

Abstract

The invention relates to a method for coordinating vehicles in a vehicle group during emergency braking, wherein a setpoint acceleration for the respective vehicle is specified as a function of an emergency braking request (zNSoll), wherein in order to implement the emergency braking request in the respective vehicle of the vehicle group in an AEBS cascade (K) at least – a first warning phase (K1) for visually and/or acoustically warning the driver of the respective vehicle of the group of vehicles and – an emergency braking phase (K3) for braking the respective vehicle of the group of vehicles as a function of the emergency braking request (zNSoll) are provided taking into account the setpoint jolt (jiSoll) at an emergency braking time (tNi), wherein for at least one vehicle a haptic warning phase (K2) is provided at a haptic time (tHi), in which warning phase (K2) the respective vehicle is continuously decelerated with an intermediate acceleration. According to the invention there is provision that the haptic time (tHi) for initiating the haptic warning phase (K2) and/or the setpoint jolt (jiSoll) for implementing the emergency braking request (zNSoll) in the emergency braking phase are defined in a vehicle-specific fashion.

Description

Method for coordinating vehicles in a vehicle group during emergency braking and a control unit

The invention relates to a method for coordinating vehicles in a vehicle group during emergency braking and a control unit for carrying out the method.

It is known that several vehicles, coordinated with one another, can move one behind the other on a lane at short actual following intervals in order to save fuel by reducing air resistance and / or to reduce driving times by automating the function. Vehicles coordinated in this way are also referred to as a vehicle group, vehicle convoi or platoon. In such a coordinated journey, the safety distance that is customary today between the individual vehicles should be undershot if the vehicles coordinate with one another, for example via wireless V2X communication. The individual vehicles of the vehicle group are coordinated, for example, by a lead vehicle that can communicate with the other vehicles via wireless V2X communication and exchange data, in particular driving dynamics data for or from the respective vehicles. In addition, information about the surroundings, including the surrounding road users who do not belong to the vehicle group, can be exchanged.

The lead vehicle can in particular set a certain target following distance and also a central acceleration request and communicate via V2X communication, the target following distance, for example, via a distance control system and the central acceleration request as target acceleration via the drive system and / or the braking system of the individual vehicles of the Vehicle group is set or implemented. This can ensure that the individual vehicles of the vehicle group can react quickly to one another, which prevents impairment of safety and thus the falling below the safety distance can be justified, since the reaction times are shortened. It is also possible that the following vehicles of the vehicle group (especially in the case of decentralized vehicle group coordination) determine their target following distances and target accelerations themselves on the basis of the available driving dynamics data and also to additional information that is contained in data signals via the V2X- Communication can be made available.

As a result, it is normally possible to coordinate the vehicle group and to operate the individual vehicles in any positive or negative acceleration situation in such a way that the vehicles within a vehicle group do not collide with one another as far as possible. For this purpose, the acceleration of the individual vehicles within the vehicle group can also be coordinated with one another in such a way that the target acceleration of the individual vehicles is limited to a maximum acceleration. The maximum acceleration depends on the vehicle with the lowest drive capacity or the lowest braking capacity within the vehicle group. This ensures that the vehicles in front of the vehicle with the lowest braking capacity do not decelerate faster or that the vehicles behind the vehicle with the lowest propulsive capacity do not accelerate positively faster, thereby avoiding a collision. However, it is problematic that within the vehicle group it is often not known how high the maximum drive capacity or the maximum braking capacity of the individual vehicles is and how quickly this can be achieved. It is also known that a vehicle with a predictive emergency braking system (AEBS, Advanced Emergency Braking System) is braked in a so-called AEBS cascade. According to DE 102008045481 A1, for example, after an emergency braking situation has been determined, there is initially a warning phase to visually and / or audibly warn the driver, a haptic braking phase in which the vehicle decelerates from a certain point in time along a predetermined partial braking ramp with a certain target jerk is provided, and an emergency braking phase for braking the respective vehicle as a function of the specified emergency braking request.

The object of the invention is to provide a method for coordinating vehicles in a vehicle group with which a safe ferry operation within the vehicle group can be guaranteed even in the case of emergency braking. The object of the invention is also to specify a control unit and a vehicle.

This object is achieved by a method according to claim 1 and by a control unit and a vehicle according to the further independent claims.

Accordingly, a method is provided for coordinating vehicles of a vehicle group during emergency braking or while an emergency braking request is present, the vehicles each having an electronically controllable braking system for implementing a required target acceleration, taking into account a target jerk and each vehicle one Position in the vehicle group is assigned, where the target acceleration for the respective vehicle is specified as a function of a manually or automatically triggered central emergency braking request of an emergency braking system. To implement the emergency braking requirement in the respective vehicle of the vehicle group, one an AEBS cascade, at least

- A first warning phase for the optical and / or acoustic warning of the driver of the respective vehicle in the vehicle group, and

- An emergency braking phase for braking the respective vehicle as a function of the emergency braking request, taking into account the target jerk, is provided at an emergency braking time assigned to the respective vehicle, whereby for at least one vehicle of the vehicle group as part of the AEBS cascade to a haptic assigned to the respective vehicle Time a haptic warning phase is provided, which lies in particular between the first warning phase and the emergency braking phase, and in which the respective vehicle is continuously decelerated with a defined intermediate acceleration that is less than the emergency braking request.

According to the invention, it is provided that the flaptic point in time for initiating the haptic warning phase and / or the target jerk for implementing the emergency braking request in the emergency braking phase are determined in a vehicle-specific manner.

The AEBS cascade of a predictive emergency braking system or AEBS (Autonomous / Advanced Emergency Braking System), which is prescribed by law and for reasons of controllability, is normally required in each of the vehicles to prevent override by the driver of the vehicle in front (lead vehicle) of the vehicle group in the event of a false detection and, on the other hand, to ensure a reaction time for the following traffic.

The AEBS cascade developed according to the state of the art normally fails here

- a first warning phase in which the driver is warned visually and / or acoustically of the emergency braking situation, - a haptic warning phase with active and continuous braking intervention, in which, in addition to the escalation of the warning in the direction of the driver, the respective vehicle is already decelerated from a certain flaptic point in time with continuous partial braking with a predetermined intermediate delay, in particular a haptic limit, and

- The emergency braking phase for braking the respective vehicle as a function of the emergency braking request, taking into account the target jerk together.

Through this AEBS cascade, both the driver of the respective vehicle and the following traffic can be prepared for a subsequent braking situation. They can then react accordingly.

This AEBS cascade can be adapted as described below for use in a vehicle network as part of the method according to the invention:

- The optical or acoustic warning in the first warning phase is output as usual to the driver of the vehicle in front (lead vehicle) of the vehicle group.

- The haptic warning including continuous partial braking with the specified intermediate deceleration (haptic warning phase) occurs for the vehicle in front at a later flaptic point in time or not at all. The duration of the haptic warning phase can therefore be reduced to Os for the lead vehicle, or the haptic time for the lead vehicle can be delayed until the emergency braking time, ie the start of the emergency braking phase, with the effect that the haptic warning phase may be omitted or greatly shortened. Optionally or in addition, it can be provided that at an initial point in time for the lead vehicle a short haptic braking jolt, ie a short impulse-like braking, takes place as a 2nd (haptic) warning level to the driver and the continuous partial braking with the specified Intermediate delay (haptic warning phase) is postponed to a later haptic point in time or is omitted entirely.

- Finally, the emergency braking phase is initiated in the vehicle in front with the maximum braking capacity, taking into account a target jerk.

Even with such an adapted AEBS cascade, the human driver can override the vehicle or lead vehicle in front and should therefore continue to include a second warning level with the aim of warning the driver, e.g. in the form of an acoustic escalation or a short one but clearly perceptible brake jolt at the initial point in time as a replacement for the delayed or omitted continuous partial braking in the haptic warning phase according to the invention. The reaction time for the following vehicle within the vehicle group is largely irrelevant with regard to the controllability assessment, since the individual vehicles within the vehicle group automatically coordinate with one another. A haptic warning phase with continuous partial braking is therefore less relevant for the vehicle in front and its duration can be reduced as required (at the expense of a longer emergency braking phase).

The normal AEBS cascade (first warning phase, haptic warning phase with partial braking of e.g. -4 m / s ² at a given point in time, emergency braking phase with maximum braking capacity, taking into account the target jerk) is only used for the last vehicle (final vehicle) in the vehicle group. implemented in order to continue to ensure controllability and the reaction time for the following traffic, which normally does not coordinate with the vehicle network. The vehicles following the vehicle group can therefore, due to the haptic warning phase, respond to a possible braking process of the final vehicle or the entire vehicle group can be set in an emergency braking situation.

In this way, a relaxation or equalization of the vehicle group can be achieved while at the same time maintaining the AEBS cascade. For example, it can be provided that the flaptic point in time to initiate the haptic warning phase and / or the target jerk to implement the emergency braking request in the emergency braking phase of the respective vehicle are set depending on the position of the vehicle within the vehicle network. Accordingly, relaxation can be achieved in a flexible manner through a position-related definition of the behavior in the haptic warning phase as well as in the emergency braking phase, with the following traffic being able to be prepared for braking at the same time.

In particular, it can be provided that the flaptic point in time for initiating the haptic warning phase decreases with increasing position in the vehicle group and / or the target jerk for implementing the emergency braking request in the emergency braking phase of the respective vehicle becomes flatter with increasing position in the vehicle group, ie a lower nominal jerk is specified with increasing position. The lowest position is assigned to the vehicle in front or the vehicle in front. The further back a vehicle travels in the vehicle group (increasing position), the lower the flaptic point in time (decreasing) or the earlier the flaptic point in time is set for this vehicle and / or the lower the value selected for the target jerk. This adaptation is possible within the vehicle group because the vehicles communicate wirelessly with one another. Therefore, by setting or adapting the flaptic point in time or the target jerk, relaxation can be ensured in a targeted manner. Preferably, it can also be provided that the target jerk to implement the emergency braking request in the emergency braking phase of the respective vehicle and / or the emergency braking time is determined as a function of an actual following distance between the relevant vehicles of the vehicle group. Accordingly, additional parameters can advantageously be used that are available within the vehicle group, for example via wireless data communication. As a result, it can advantageously be taken into account that a distance reserve may have built up within the haptic warning phase, whereupon the emergency braking phase for a specific vehicle can be initiated earlier and with a steeper ramp. This allows emergency braking to be made safer.

Preferably, it can also be provided that the emergency braking point for the respective vehicle is determined as a function of the flaptic point in time and / or the position of the respective vehicle within the vehicle network. This can also take into account whether and when the respective vehicle is already braked in the haptic warning phase and has thus built up a distance reserve. On the basis of this and also the position of the respective vehicle, it can then be assessed whether the emergency braking phase can already be initiated at an earlier point in time and / or with a different target jerk.

In order to achieve a greater "distance reserve" within the vehicle group in emergency braking situations triggered by the predictive AEBS (Advanced Emergency Braking System), provision can be made for the actual distances to be increased slowly in the first warning phase of the AEBS cascade, e.g. due to the expected false alarm rates energy- and wear-efficient by limiting the engine torques of the individual vehicles through appropriate control of the drive system. This long- The same increase in the actual distance causes a slow change in the actual vehicle dynamics of the individual vehicles, this change being easily implemented by each of the vehicles in the vehicle group.

In the event of a false triggering of the AEBS, the driver in the lead vehicle has the option of canceling the triggered emergency braking process, e.g. by pressing the accelerator pedal, during the entire AEBS cascade (driver override). In this case, the braking interventions in the vehicle network must be resolved from front to back, ie in reverse order to the entry into the AEBS cascade and advantageously by means of a braking ramp, in order to avoid a collision after the manual driver intervention to abort the AEBS cascade within the Exclude vehicle group and then allow a superimposed distance control.

It is also preferably provided that at least the following steps are carried out:

- Implementation of the emergency braking request in each vehicle of the vehicle network by electrically actuating the braking system of the respective vehicle, taking into account the target jerk and predetermined vehicle-specific acceleration parameters, the acceleration parameters determining how the requested emergency braking request is implemented;

- Observation of the actual driving dynamics of the vehicles of the vehicle group during the implementation of the emergency braking request, taking into account the target jerk and the vehicle-specific acceleration parameters;

- Evaluating the observed actual driving dynamics of the vehicles on the basis of the requested target acceleration for the respective vehicle, taking into account the target jerk and the vehicle-specific acceleration parameters and outputting a vehicle-specific evaluation result;

- Determining and outputting an acceleration limit value and / or a nes jerk limit value depending on the vehicle-specific evaluation result and adaptation of the vehicle-specific acceleration parameters in at least one of the vehicles of the vehicle group depending on the determined acceleration limit value and / or jerk limit value to implement the emergency braking request, taking into account the adapted vehicle-specific acceleration parameters.

The term vehicle-specific is understood here to mean that a parameter set of acceleration parameters or an evaluation result is assigned to each vehicle. This advantageously ensures that a check is carried out individually for each vehicle as to whether it is able to implement the required acceleration or the emergency braking request, taking into account the desired jerk. For this purpose, the maximum braking capacity and / or the maximum drive capacity of the respective vehicle is taken into account by observing and evaluating in situ, so that this does not necessarily have to be determined in advance and safe ferry operation can still be guaranteed. On the other hand, an already available parameter set of acceleration parameters can be used as initialization, for example in the event of a change in the vehicle group. The acceleration parameters can also be used to specify vehicle-specific how the driving dynamics of the respective vehicle are to be adapted in the direction of the requested target acceleration or the emergency braking requirement in order to avoid the vehicles colliding with during observation and evaluation.

In this way, the method enables secondary accidents in the vehicle group to be avoided, particularly in vehicle dynamic limit situations or in the present emergency braking situation, and at the same time also enables the vehicle group to be braked as quickly as possible. It is preferably provided that the evaluation of the observed actual driving dynamics includes a comparison of the actual driving dynamics with a target driving dynamics for the respective vehicle in order to determine whether the respective vehicle is able to achieve the target driving dynamics, the target Driving dynamics is preferably given by the emergency braking request, taking into account the target jerk and the acceleration parameters. A simple target / actual comparison is thus possible in situ, from which it can be derived directly whether the respective vehicle is capable of implementing the emergency braking request.

It is preferably also provided that the vehicle-specific acceleration parameter is a start acceleration to define an initial intermediate acceleration of the respective vehicle in the haptic warning phase and / or a start jolt to adapt the intermediate acceleration in the direction of the requested emergency braking request in the emergency braking phase can be specified in order to implement the requested emergency braking request taking into account the acceleration parameters. In this way, the respective vehicles can advantageously be given a start-up driving dynamics that each vehicle is preferably able to perform with a high degree of probability. On the basis of this, the starting acceleration gradient or the starting jolt can be used as a target acceleration gradient or target jolt to be specified in a vehicle-specific manner as to how the respective vehicle is to be accelerated in order to achieve the target acceleration, as follows that it is possible to continuously check for each vehicle whether the maximum drive or braking capacity has been reached.

It is preferably also provided that a maximum acceleration and / or a maximum jerk are defined as the acceleration parameters to limit a currently requested intermediate acceleration and / or the target jerk at least when the requested emergency braking request taking into account the vehicle-specific acceleration parameters in the emergency braking phase. Accordingly, a limit can be specified for the respective vehicles, especially for the emergency braking phase, which can be specified or adapted for optimal coordination of the entire vehicle group, for example depending on the maximum drive capacity and / or the maximum braking capacity of one of the vehicles in the vehicle group.

This maximum acceleration or this maximum jolt are preferably set in such a way that they correspond to the maximum braking capacity of the vehicle that brakes the worst. This is advantageously characterized by the acceleration and / or jerk limit values ascertained in the method, so that the maximum acceleration or the maximum jerk can preferably be defined and / or adapted as a function of this.

It can preferably be provided that the maximum acceleration as a function of the determined acceleration limit value and / or the maximum jerk as a function of the determined jerk limit value are only adapted for the vehicles of the vehicle group which, when the emergency braking request is specified before Drive the vehicle assigned to the acceleration limit value and / or the jerk limit value. In this way, the acceleration or the jerk is advantageously limited only for the vehicles in the vehicle group which, without the limitation, would collide with one of the vehicles in the vehicle group.

It is preferably also provided that the start jolt of the respective vehicle is determined as a function of the position of the vehicle within the vehicle group, the start jolt of the respective vehicle with increasing position within the vehicle group decreases, the position of the first vehicle of the vehicle group is less than the position of the last vehicle of the vehicle group. This ensures that not every vehicle has to be braked to the same extent based on the starting acceleration or the haptic limit in the emergency braking phase.

As a result, the vehicles can advantageously be braked with one another during the observation and evaluation phase with different driving dynamics, and with a correspondingly positionally accurate selection of the target jerk, an overrun during emergency braking can be avoided. This is advantageously achieved in that, in the event of an emergency braking request, a lower value (and higher amount) start jerk is set for the last vehicle, which results in a steeper ramp in terms of amount and thus a greater change in the deceleration (negative Acceleration) in the direction of the emergency braking request. In this way, the last vehicle with the higher position is braked with the lowest (or highest in terms of amount) nominal jerk, so that it does not run into the previously driving vehicles that are braked with a higher (or lower in terms of amount) nominal jerk can. This applies successively to all other vehicles in an analogous manner.

It is also preferably provided that the observation of the actual driving dynamics is the temporal observation of an actual vehicle speed of the respective vehicle and / or an actual acceleration of the respective vehicle and / or an actual jolt of the respective vehicle, taking into account a response time and / or an actual distance between two vehicles in the vehicle group and / or an actual distance change in the actual distance between two vehicles in the vehicle group. The response time indicates how quickly the brake system of the respective vehicle reacts to an acceleration request, this being dependent, for example, on a time for pressure build-up, etc. This makes it possible to identify in a simple manner whether or not the respective vehicle can achieve the target acceleration or the emergency braking request with the target jerk, taking into account the acceleration parameters.

The evaluation via the actual distance or the actual distance change is particularly advantageous in slip situations, ie during a braking intervention or a drive intervention, since the measurement or estimation of the actual vehicle speed or the actual speed -Acceleration under the influence of slip (brake slip, drive slip) is faulty and can therefore only indirectly serve the actual safety goal of collision avoidance. The actual distance or the change in actual distance, on the other hand, are directly related to a potential collision risk and can therefore also be useful for the safety goal in slip situations. Preferably, the actual vehicle speed or the actual acceleration can nevertheless be used for plausibility checks and / or outside of strong braking interventions or drive interventions.

It is preferably also provided that the vehicle-specific evaluation result with regard to the question of whether the respective vehicle changes its actual driving dynamics in terms of the acceleration parameters is formed as a function of whether

- the actual vehicle speed of the respective vehicle remains constant, and / or

- the actual acceleration of the respective vehicle remains constant or decreases in amount within a predetermined period of time, the predetermined period of time being dependent on the target jerk taking into account the response time, and / or

- the actual distance between two vehicles remains constant or less will, and / or

- the actual distance change is less than or equal to zero.

It is preferably also provided that the target acceleration and / or the target jerk and / or the vehicle-specific acceleration parameters for the respective vehicle are set decentrally in the respective vehicles as a function of wireless between the vehicles via transmitted data signals or centrally in one of the vehicles become. The method can thus be used in a vehicle group that coordinates itself centrally, for example starting from a lead vehicle, or uses decentralized coordination in which the respective vehicles themselves determine and adapt their driving dynamics as a function of exchanged data signals.

In addition, it can be provided that during the implementation of the emergency braking request, taking into account the target jerk and the vehicle-specific acceleration parameters, it is checked whether the actual distance between the individual vehicles of the vehicle group falls below a specified target distance for the respective vehicles. Accordingly, a distance control can be superimposed on the method in order to, in addition to the optimized setting of the target acceleration, avoid an overrun if necessary and thus make the method safer.

Furthermore, a control unit is provided for a vehicle that is located in a vehicle group, in which in particular the method according to the invention can be carried out, the control unit being designed, the emergency braking request as the target acceleration in the respective vehicle of the vehicle group by electrically actuating the Implement the braking system of the respective vehicle, the target acceleration for the respective vehicle depending on a manual or automatically triggered emergency braking request can be specified, the control unit being designed in an AEBS cascade

- To request an optical and / or acoustic warning to the driver of the respective vehicle in the vehicle group in a first warning phase, and

- To implement a braking of the respective vehicle of the vehicle group in an emergency braking phase depending on the emergency braking request, taking into account the target jerk at an emergency braking time, the control unit for at least one vehicle of the vehicle group as part of the AEBS cascade at a flaptic time cal warning phase, in which the respective vehicle can be continuously decelerated with a defined intermediate acceleration that is lower than the emergency braking requirement. According to the invention, it is provided that the control unit is designed to determine the flaptic point in time for initiating the haptic warning phase and / or the target jerk for implementing the emergency braking request in the emergency braking phase in a vehicle-specific manner.

The invention is explained in more detail below using an exemplary embodiment. Show it:

1 shows a schematic view of a vehicle group consisting of three vehicles;

2a, 2b, 2c exemplary AEBS cascades during an emergency braking situation; and

3 shows a flow chart of the method according to the invention.

In Figure 1, a vehicle group 1 or platoon of three vehicles 2i, with i = 1, 2, 3 is shown, which are in a certain actual following distance dlstj with j = 1, 2 move towards each other. The first vehicle 21 of the vehicle association 1 is referred to as the lead vehicle X, while the second vehicle 22 and the third vehicle 23 are following vehicles Y of the vehicle association 100. The third vehicle 23 is referred to as the last vehicle of the vehicle group 1 as the terminating vehicle Z.

The actual following distances dlstj can be set in normal ferry operation of the vehicle group 1 in such a way that they fall below the safety distance between the individual vehicles 2i that is customary today. This can be justified in that the individual vehicles 2i communicate with one another via wireless data communication 9, in particular V2X communication, and use this to coordinate their journey with one another. As V2X communication (Vehicle-to-Everything), a wireless communication option is referred to in the context of the invention, which allows the individual vehicles 2i to provide and receive data signals S be via a specific interface or according to a specific protocol to coordinate. The data signals S contain, for example, information or data about dynamic driving properties of the individual vehicles 2i and / or relevant information or data relating to the vehicle group 1.

For this purpose, a V2X unit 10 is arranged in each of the vehicles 2i, which has a transmission and reception module (not shown) in a conventional manner, via which the data signals S can be sent and received. Depending on the exchanged data signals S, the driving dynamics of the individual vehicles 2i in the vehicle group 1 can subsequently be adapted. For this purpose, for example, a target acceleration aiSoll is specified as a function of the data signals S and this is implemented in the respective vehicle 2i. The setpoint acceleration aiSoll is implemented in the respective vehicle 2i, taking into account a setpoint jerk jiSoll, ie a gradient of the setpoint acceleration aiSoll. In the exemplary embodiment shown, each vehicle 2i has a distance control system 5 which is designed to detect the current actual following distance dlstj as a function of data from an internal environment detection system 6 and to regulate this to a predetermined target following distance dSollj, this being shown in the figure Vehicle group 1 is only relevant for the following vehicles 22, 23 (Y). The distance control system 5 is connected in a signal-conducting manner to an electrically controllable drive system 7 and an electrically controllable brake system 8 in order to be able to positively accelerate or decelerate the respective vehicle 2i and thus to set the predetermined target following distance dSollj.

The target-following distance dSollj is specified in normal operation of the vehicle group 1 via a control unit 4 in the respective vehicle 2i. The control unit 4 is connected to the V2X unit 10 in a signal-conducting manner or is integrated into it and can therefore access the information and data from the data signal S. As a function of the data signal S, the setpoint following distance dSollj, which is matched to the current driving situation of the vehicle group 1, is specified by the control unit 4. The target following distance dSollj can, for example, be determined or established centrally and transmitted to the individual vehicles 2i of the vehicle group 1 in the data signal S via the wireless data communication 9. The control unit 4 then only forwards the target following distance dSollj within the vehicle 2i. The control unit 4 can, however, also (decentrally) derive the setpoint following distance dSollj itself for its own vehicle 2i on the basis of the information and data transmitted via the data signal S.

The setpoint following distance dSollj is then transmitted from the control unit 4 to the distance control system 5. The distance control system 5 then generates a setpoint as a function of the determined setpoint following distance dSollj and the currently available actual following distance dlstj. Acceleration aiSoll, which is implemented accordingly via the drive system 7 or the brake system 8 of the respective vehicle 2i with a certain setpoint jerk jiSoll. The target acceleration aiSoll is thus determined in the distance control system 5 as a function of the data signal S or the information and data contained therein.

A setpoint acceleration aiSoll for the respective vehicle 2i can not only be specified by the distance control system 5. Rather, the target acceleration aiSoll can also be set or output directly by the control unit 4 and / or by further driver assistance systems 11 in the respective vehicle 2i, which then electrically control the drive system 7 or the brake system 8, either indirectly or directly as a function thereof to implement the target acceleration aiSoll in the vehicle 2i. A centrally defined target acceleration aiSoll can also be transmitted to the respective vehicle 2i via the wireless data communication 9 and output from the control unit 4 directly or indirectly, e.g. via the distance control system 5, to the drive system 7 or the brake system 8.

For example, an emergency braking request zNSoll for implementation in all vehicles 2i of vehicle group 1 can be generated by one of the vehicles 2i of the vehicle group 1 when a dangerous situation is recognized, for example by a forward-looking emergency braking system 12 (AEBS, Advanced Emergency Braking System). This emergency braking requirement zNSoll is transmitted as a (negative) target acceleration aiSoll via the wireless data communication 9 to the individual vehicles 2i of the vehicle group 1 and received therein by the respective control unit 4 and transmitted to the brake system 8 for implementation.

In the same way, other central acceleration requirements alN can also be implemented in all vehicles 2i of the vehicle. vehicle group 1 as a target acceleration aiSoll are transmitted to the individual vehicles 2i.

The implementation of the emergency braking request zNSoll takes place normally in each vehicle 2i according to an AEBS cascade K (see Fig. 2a, 2b), which includes a first warning phase K1 (visual (display) and / or acoustical (warning signal)) haptic warning phase K2 and a final emergency braking phase K3, ideally with the specified emergency braking request zNSoll included. This AEBS cascade K is advantageous in order to enable oversteering, in particular by the driver of the vehicle 21 in front (lead vehicle X) of the vehicle group 1 in the event of a false detection (in the first warning phase K1) and to ensure a reaction time for the following traffic ( haptic warning phase K2).

To improve the braking of the vehicles 2i of the vehicle group 1 in an emergency braking situation recognized by the emergency braking system 12, provision can be made to adapt the AEBS cascade K as follows:

First, the actual distances dlstj between the vehicles 2i of the vehicle group 1 can be slowly increased by adjusting the target acceleration aiSoll in the first warning phase K1 of the AEBS cascade K, e.g. energy- and wear-efficient by limiting or adapting the engine torques or the drag torques of the individual vehicles 2i. As a result, the driving dynamics can be adjusted and the situation can be escalated with only a few active braking interventions. This slow increase in the actual distance dlstj causes a slow change in the actual vehicle dynamics flst of the individual vehicles 2i, this change being easily implemented by each of the vehicles 2i of the vehicle group 1. In the haptic warning phase K2, from a haptic point in time tHi, continuous partial braking of at least some of the vehicles 2i of the vehicle formation 1 takes place by specifying an intermediate acceleration aiZ, the intermediate acceleration aiZ in the haptic warning phase K2 for the respective vehicle 2i is set to a haptic limit aiH, for example -4m / s ² . The haptic braking phase K2 serves to escalate the emergency braking situation and to warn the driver, with the actual vehicle speed vi of the respective vehicle 2i being continuously reduced at the same time.

With increasing automation within the vehicle group 1, this escalation or driver warning is not or at least less relevant within the vehicle group 1, so that the haptic warning phase K2 can be adapted vehicle-specifically as follows:

As shown in Fig. 2a, the optical and / or acoustic warning in the first warning phase K1 is output to the driver of the vehicle ahead 21 (lead vehicle X) as usual for the preceding vehicle 21 (lead vehicle X) in order to warn him . The haptic warning phase K2 with continuous partial braking can then take place at a later point in time than usual, as shown in FIG. 2a, or can be omitted entirely, as shown in FIG. 2b. In addition, a haptic brake jolt R can occur for the lead vehicle 21, for example at an initial point in time tl1, which in particular replaces the haptic warning phase K2 with continuous partial braking, which is omitted in FIG. 2b, in order to warn the driver a second time.

As a result, it is still possible for the human driver in the vehicle 21 driving ahead (lead vehicle X) to override it, since he receives a warning in the first warning phase K1. The continuous partial braking in the haptic warning phase K2 can be developed for the lead vehicle X fall (see Fig. 2b) or take place very late (see Fig. 2a), since the following vehicles 2i of the vehicle group 1 coordinate via the wireless data communication 9 and thus not be aware of an imminent braking in this way are to be made. This means that the situation for lead vehicle X initially escalates with a very late reduction in speed or without any reduction in speed. He can still be warned via the haptic braking jolt R.

For the last vehicle 23 (terminating vehicle Z) in the vehicle group 1, the normal AEBS cascade K (first warning phase K1, haptic warning phase K2 with a haptic limit aiH of, for example, -4 m / s ² at a given haptic point in time tH3 This allows override in the first warning phase K1 as well as controllability or a reaction time for the following traffic behind the last vehicle 23 of the vehicle group 1. The following traffic can therefore communicate with the vehicle group without wireless data communication 1 set and prepare for (emergency) braking, as continuous partial braking with the haptic limit aiH is present in the haptic warning phase K2.

As part of a coordinated strategy of all vehicles 2i of the vehicle group 1, the haptic times tHi for initiating the haptic warning phase K2 of the respective vehicle 2i can be selected according to a first predetermined functional relationship H1. This is set, for example, such that the haptic times tHi for the vehicles 2i between the lead vehicle X and the terminating vehicle Z are evenly distributed between the haptic instant tH1 for the lead vehicle X and the haptic instant tH3 for the terminating vehicle Z. . If there is no haptic time tH1 for the lead vehicle X, since no haptic warning phase K2 is provided for this (see FIG. 2b), an emergency braking time tN1 is assumed as the haptic time tH1 for the lead vehicle X, for example, at which the Lead vehicle X initiates the emergency braking phase K3.

The haptic warning phase K2 is followed by the emergency braking phase K3, in which the respective vehicle 2i, starting from the haptic limit aiH, insofar as the haptic warning phase K2 is carried out, at a respectively assigned emergency braking time tNi in the direction of the (negative) target acceleration aiSoll or the specified emergency braking request zNSoll is braked. This takes place with a predetermined nominal jerk jiSoll, which is preferably constant, so that there is a continuously increasing braking ramp (see FIGS. 2a, 2b).

The emergency braking time tNi is preferably identical for all vehicles 2i for which there is a hap-table warning phase K2, as shown in FIGS. 2a and 2b. According to FIG. 2b, the lead vehicle X can go over to the emergency braking phase K3 at an earlier emergency braking time tN1 without the vehicles 2i within the vehicle formation 1 colliding with it. It is assumed here that the lead vehicle X has built up a sufficiently large actual distance dlstl from the second vehicle 22 due to the lack of haptic warning phase K2 and thus the lack of braking with the haptic limit aiH. As a result, a distance reserve has built up that can be used for lead vehicle X by initiating the emergency braking phase K3 earlier. The emergency braking time tN1 and possibly also the target jerk j1 target for the lead vehicle X can for example be selected depending on the current actual distance dlstl between the lead vehicle X and the second vehicle 22 in order to maintain the distance reserve when the Emergency braking phase K3 for lead vehicle X must be taken into account. In addition or as an alternative to the haptic points in time tHi, the target jerks jiSoll for the respective vehicles 2i can also be specified vehicle-specifically according to a given second functional relationship H2 in order to brake the vehicles 2i in the emergency braking phase K3 in the vehicle group 1 in a coordinated manner. This second functional context H2 is set, for example, in such a way that the target jerk jiSoll for the vehicles 2i between the lead vehicle X and the closing vehicle Z is evenly distributed between the target jerk jiSoll for the lead vehicle X and the target jerk j3Soll for the Closing vehicle Z lie.

In particular, it can also be provided to select the target jerk jiSoll for the vehicles 2i after the lead vehicle X in the emergency braking phase K3 identically and only the haptic times tHi for the haptic warning phase K2 depending on the position Pi according to the first functional context Adjust H1. It is taken into account that the respective vehicles 2i of the vehicle group 1 build up a distance reserve within the haptic warning phase K2 and can then be braked at a safe distance with the same target jerks jiSoll as part of the emergency braking. As a result, the vehicle group 1 is already relaxed in the haptic warning phase K2.

Alternatively, the same haptic times tHi for initiating the haptic warning phase K2 can be selected for all vehicles 2i behind the lead vehicle X and the target jerks jiSoll can be set according to the second functional relationship H2 as a function of the position Pi. This also results in relaxation, which takes place in the emergency braking phase K3 by means of different strong brakes (jiSoll). As shown in Fig. 2a, a combination of both possibilities can also be provided. As a result, the vehicle group 1 is relaxed both in the haptic warning phase K2 and in the emergency braking phase K3.

The driver of the respective vehicle 2i is additionally prepared for the emergency braking solution and an escalation with a speed reduction in a correspondingly coordinated manner depending on the position Pi in the vehicle group 1 is guaranteed. The functional relationships H1, H2 can be linear depending on the position Pi or they can follow another predetermined function.

The target acceleration aiSoll, also as an emergency braking request zNSoll, can also be specified manually by the driver, for example by actuating an actuator when a dangerous situation (emergency braking situation) or the like is detected, and implemented via the control unit 4 and at the same time to the other vehicles 2i des Vehicle group 1 are communicated.

The control unit 4 can preferably also be designed to set vehicle-specific acceleration parameters Bi with which the drive system 7 and / or the brake system 8 of the respective vehicle 2i a predetermined target acceleration aiSoll, in particular the emergency braking request zNSoll in the emergency braking phase K3 and / or the Intermediate acceleration aiZ in the haptic warning phase K2, while driving in the vehicle group 1 implemented. The acceleration parameters Bi are preferably used in the implementation of any target accelerations aiSoll (distance control system 5, control unit 4, driver assistance system 11, predictive emergency braking system 12 (zNSoll)), this being done, for example, by a corresponding transmission of the acceleration parameters Bi to the electronically controllable drive system 7 or braking system 8 takes place. The target acceleration aiSoll, in particular the emergency braking request zNSoll or intermediate acceleration aiZ, can, however, in principle in the haptic warning phase K2 and the emergency braking phase K3 can also be implemented without taking these acceleration parameters Bi into account.

Vehicle-specific, for example, a start acceleration aiStart and / or a maximum acceleration aiMax and / or a start jerk jiStart and / or a maximum jerk jiMax can be specified as the acceleration parameter Bi. This has the following effects on the AEBS cascade K (see Fig. 2c):

If a specific target acceleration aiSoll or emergency braking request nZSoll is requested, the respective vehicle 2i is initially negatively accelerated in the haptic warning phase K2 with an intermediate acceleration aiZ, which is defined by the predefined starting acceleration aiStart. The haptic limit aiH is therefore overwritten, whereby a stipulation can also be made that the higher of the two values, i.e. aiStart or aiH, is used in the haptic warning phase K2. The starting acceleration aiStart (and also the haptic limit aiH) is normally lower in terms of amount than the specified target acceleration aiSoll, in particular the emergency braking request zNSoll, and has a value that every vehicle 2i is normally able to provide.

On the basis of this, the start jerk jiStart indicates how the intermediate acceleration aiZ, based on the start acceleration aiStart in the emergency braking phase K3, is to be increased in terms of amount over time in order to bring the intermediate acceleration aiZ to the requested target acceleration aiSoll or . to approximate the emergency braking requirement zNSoll. The start jerk jiStart is thus initially defined as the nominal jerk jiSoll as a possible initial value, where this can also be subsequently adjusted or another initial value can be defined. The maximum acceleration aiMax specifies an additional limit which the intermediate acceleration aiZ must not exceed in terms of amount, in principle both in the haptic warning phase K2 and in the emergency braking phase K3, it being assumed that the start acceleration aiStart and also the haptic -Limit aiH are lower. The maximum acceleration aiMax can, however, under certain circumstances be lower in terms of amount than the requested target acceleration aiSoll, in particular the emergency braking request zNSoll, as shown for some vehicles in FIG. 2c.

The maximum jerk jiMax also specifies a limitation of the setpoint jerk jiSoll, the amount of which is not to be exceeded in terms of amount, in particular in the emergency braking phase K3. The maximum acceleration aiMax and / or the maximum jerk jiMax can follow, for example, from the maximum drive capacity AVMax or the maximum braking capacity BVMax, which can be provided by the drive system 7 or the braking system 8 of the respective vehicle 2i. The maximum acceleration aiMax and / or the maximum jerk jiMax can also be specified for the control unit 4 of the respective vehicle 2i, for example via the V2X unit 10.

The starting acceleration aiStart and the starting jerk jiStart can also be specified for the control unit 4 by the V2X unit 10, whereupon the control unit 4 uses them in its own vehicle 2i to implement a present target acceleration aiSoll, taking into account the target jerk jiSoll specifies.

The definition of vehicle-specific acceleration parameters Bi enables the vehicles 2i of the vehicle group 1 to be coordinated in a targeted manner, which is explained in more detail below with reference to FIGS. 2c and 3: After an initialization of the control units 4 in the vehicles 2i of the vehicle group 1 in an initial step STO (Fig. 3), for example when starting the vehicle 2i or when entering a vehicle group 1, an arbitrarily requested target is set in a first step ST1 - Acceleration aiSoll recorded or read in for the respective vehicle 2i.

In order to positively or negatively accelerate the entire vehicle group 1 in a safe manner according to the target acceleration aiSoll and to optimally coordinate the individual vehicles 2i within the scope of their performance, the vehicle-specific acceleration parameters Bi for each individual drive are set in a second step ST2 stuff 2i set. The definition takes place either centrally in one of the vehicles 2i of the vehicle group 1 with subsequent transmission to the individual vehicles 2i via wireless data communication 9 or at least partially decentrally in each vehicle 2i separately, with transmitted data signals S being taken into account.

In a first intermediate step ST2.1, a suitable start acceleration aiStart is specified for this purpose, which is assumed to be provided by each of the vehicles 2i of the vehicle group 1. In a second intermediate step ST2.2, the start jerk jiStart is defined as the initial value of the target jerk jiSoll, insofar as no other initial definition has been made, with each vehicle 2i being assigned an individual start jerk jiStart as the target jerk jiSoll . The start jerk jiStart is determined in particular as a function of a position Pi of the respective vehicle 2i within the vehicle group 1.

In a third intermediate step ST2.3, the maximum acceleration aiMax and / or the maximum jerk jiMax for the respective vehicle 2i is determined, for example as a function of the maximum possible approach Driving capacity AVMax or braking capacity BVMax of the respective vehicle 2i. If the maximum acceleration aiMax or the maximum jerk jiMax is not yet known at this point in time or cannot be determined, these are initially left open or set to a high value, for example the currently specified target acceleration aiSoll.

As shown in FIG. 2c, the start jerk jiStart is defined as the target jerk jiSoll as a function of the position Pi of the respective vehicle 2i within the vehicle group 1 in such a way that the start gradient jiStart increases in terms of amount with increasing position Pi (i.e. also falls).

Accordingly, the third intermediate acceleration a3Z of the third vehicle 3 at the third position P3 is increased in terms of amount when the actual vehicle speed vi (aiSoll negative (zNSoll)) is requested along a steeper ramp (jiSoll, jiStart) than the first Intermediate acceleration a1Z of the first vehicle 1 at the first position P1.

This is based on the idea of accelerating or decelerating a vehicle 2i moving further back within the vehicle group 1 more negatively than a vehicle 2i moving further ahead in order to prevent a collision of the vehicles 2i in the respective driving situation. This is achieved precisely in that the vehicle 2i traveling further back reduces its intermediate acceleration aiZ to a greater extent than the vehicle or vehicles 2i traveling in front of it, starting from the starting acceleration aiStart.

According to the exemplary embodiment shown in FIG. 2c, the intermediate acceleration aiZ is increased or decreased starting from the starting acceleration aiStart for all vehicles 2i at a common emergency braking time tN1, tN2, tN3 with different values for the target jerk jiSoll. As already described for FIGS. 2a and 2b, this can also be adapted.

As an alternative or in addition to such a definition of different values for the target jerk jiSoll as a function of the position Pi of the respective vehicle 2i, the emergency braking times tNi at which the respective vehicle 2i starts its intermediate acceleration aiZ based on the starting acceleration aiStart (or the haptic limit aiH) adapts with the nominal jerk jiSoll, vary depending on the position Pi. Accordingly, the third vehicle 23 can, for example, enter the emergency braking phase K3 earlier than the other two vehicles 21, 22. This also ensures that vehicles 2i of the vehicle group 1 traveling one behind the other are continuously braked with different intermediate accelerations aiZ and thus not on each other be able to walk. Preferably, however, the selection of different start jerks jiStart or target jerks jiSoll depending on the position Pi and a simultaneous increase in the intermediate acceleration aiZ for each vehicle 2i is provided in order to achieve the required target acceleration aiSoll for the to shorten the entire vehicle group 1, which is particularly important in emergency braking situations.

In a third step ST3, the previously defined acceleration parameters Bi are used directly or indirectly to implement the target acceleration aiSoll given in the first step ST1, taking into account the target jerk jiSoll via the drive system 7 or the braking system 8 of the respective vehicle 2i. Rules are thus imposed on the respective vehicle 2i as to how it has to implement a predefined setpoint acceleration aiSoll.

In a fourth step ST4, the driving dynamics behavior (actual driving dynamics flst) of the vehicles 2i of the vehicle group 1 during a ner implementation of the target acceleration aiSoll using the acceleration parameters Bi and taking into account the target jerk jiSoll observed. This can take place, for example, in that a present actual acceleration ailst and / or the actual vehicle speed vi and / or an actual jolt jilst of the respective vehicle 2i of the respective vehicle 2i are determined. This observation can take place decentrally in each of the vehicles 2i or centrally in one of the vehicles 2i, in that the actual acceleration ailst and / or the actual vehicle speed vi is transmitted wirelessly between the vehicles 2i in a time-resolved manner via the data signals S .

Alternatively, the actual distance dlstj between the individual vehicles 2i and / or an actual distance change dAlstj can also be viewed resolved over time in order to observe the actual driving dynamics flst of a vehicle 2i. Accordingly, it can be determined, for example by means of sensors, how quickly two vehicles 2i are approaching or moving away from one another.

In a fifth step ST5, the observed actual driving dynamics flst (ailst, vi, dlstj, dAlstj, jilst) are compared with a target driving dynamics fSoll, the target driving dynamics fSoll by the target acceleration aiSoll taking into account the target jerk jiSoll and the acceleration parameter Bi is given. Depending on this comparison, a vehicle-specific evaluation result Ei is output, which indicates whether the respective vehicle 2i is able to adapt the intermediate acceleration aiZ taking into account the target jerk jiSoll and the acceleration parameter Bi and the target acceleration aiSoll in this Way to achieve.

If for a vehicle 2i of the vehicle group 1 it is established, for example, that

- the actual acceleration does not increase further in terms of amount and at the same time the target acceleration aiSoll has not yet been reached or the actual acceleration always decreases in terms of amount within a predefined time period tR, the predefined time period tR being dependent on the setpoint jerk jiSoll taking into account a response time tA, or

- the actual distance dlstj does not behave in accordance with the predefined setpoint driving dynamics fSoll of the two vehicles 2i driving at the actual distance dlstj or the actual change in distance dAlstj does not correspond to the expected behavior (decrease or increase), a Evaluation result Ei is output for the respective vehicle 2i, which indicates that the respective vehicle 2i is unable to adapt the intermediate acceleration aiZ taking into account the target jerk jiSoll and the acceleration parameter Bi and to achieve the target acceleration aiSoll in this way.

Then, in a sixth step ST6, the currently present actual acceleration is set as the maximum acceleration aiMax and / or the present actual jolt jilst as the maximum jerk jiMax for the respective vehicle 2i. The value for the maximum acceleration aiMax and / or the maximum jerk jiMax that has meanwhile been assumed in the third intermediate step 2.3 is thus confirmed, overwritten or supplemented. This maximum acceleration aiMax or this maximum jerk jiMax is then transmitted in a seventh step ST7 as an acceleration limit value aT or jerk limit value jT via the data signal S to the other vehicles 2i of the vehicle group 1. The respective vehicle 2i or its position Pi can also be assigned in the data signal S to the acceleration limit value aT or the jerk limit value jT.

In an eighth step ST8, the transmitted acceleration limit value aT or jerk limit value jT is used as acceleration parameter Bi or as maximum acceleration aiMax or maximum jerk jiMax for the other vehicles 2i of vehicle group 1. The maximum accelerations aiMax thus become maximum jerks jiMax of all vehicles 2i of the vehicle group 1 is set uniformly to the previously determined acceleration limit value aT or jerk limit value jT. Alternatively, it can also be provided that the transmitted acceleration limit value aT or jerk limit value jT is only used in vehicles 2i as maximum acceleration aiMax or maximum jerk jiMax, which is aiSoll, especially emergency, in the case of a negative target acceleration braking request zNSoll, drive in front of the vehicle 2i assigned to the acceleration limit value aT or jerk limit value jT. For this purpose, the position Pi of the respective vehicle 2i assigned to the acceleration limit value aT or jerk limit value jT can be taken into account.

In this way, when adjusting the respective intermediate acceleration aiZ according to the target jerk jiSoll for each vehicle 2i, it can be successively determined which maximum acceleration aiMax or which or maximum jerk jiMax is relevant and whether the driving dynamics of the further vehicles 2i of the vehicle group 1 is to be adapted in order to avoid the vehicles 2i running into the respective driving situation, in particular in the emergency braking phase K3.

This is shown by way of example in FIG. 2c. Accordingly, the requested target acceleration aiSoll is reached in the emergency braking phase K3 for the third vehicle 23 at the third position P3 of the vehicle group 1, where the maximum acceleration aiMax for the third vehicle 3 either corresponds to the target acceleration aiSoll or this has not yet been reached. For the second vehicle 22, the intermediate acceleration aiZ in the emergency braking phase K3 reaches the second maximum acceleration a2Max from a certain point in time, for example because the maximum braking capacity BVMax for the second vehicle 22 has been reached. The second maximum acceleration a2Max is lower than the requested target acceleration a2Soll (corresponds to zNSoll). This also has effects on the first vehicle 21 at the first position P1, which accordingly also Is to be braked x times with the second maximum acceleration a2Max in order to avoid the second vehicle 22 running into the first vehicle 21. Accordingly, the second maximum acceleration a2Max is transmitted as an acceleration limit value aT with the assignment to the second vehicle 22 (second position P2) via the wireless data communication, in particular to the first vehicle 21. In this, the acceleration limit value aT is used as one of the acceleration parameters B1 to define the first maximum acceleration a1 Max, so that the first vehicle 21 in the emergency braking phase K3 with a maximum of the first or second maximum acceleration a1 Max ( = a2Max) decelerates. Since the implemented acceleration from the first vehicle 21 lags behind the implemented acceleration from the second vehicle 22 during the braking process, real-time transmission of the second maximum acceleration a2Max just determined of the second vehicle 22 can ensure that the first vehicle 21 is still on during the braking process the limit of the second vehicle 22 that has just been reached, ie a2Max, reacts. As a result, an improved accident avoidance within the vehicle group 1 can be achieved.

This described process sequence can therefore be used to optimize and homogenize the maximum accelerations aiMax over the entire vehicle group 1, so that the individual vehicles 2i can be prevented from running into one another within the vehicle group 1 in the respective driving situation. List of reference symbols (part of the description)

I vehicle group (platoon)

2i i-th vehicle in the vehicle group

4 control unit

5 Distance control system

6 internal environment detection system

7 drive system

8 braking system

9 wireless data communication (V2X)

10 V2X unit

I I driver assistance system

12 Predictive emergency braking system (AEBS) as actual acceleration aiMax Maximum acceleration aiH Haptic limit aiSoll Target acceleration aiStart Start acceleration aiZ Intermediate acceleration alN Central acceleration request aT Acceleration limit value

AVMax maximum drive capacity

Bi vehicle-specific acceleration parameters

BVMax maximum braking capacity dlstj actual following distance dAlstj actual following distance change dSollj target following distance

Ei evaluation result flst actual driving dynamics fSoll target driving dynamics

H1 first functional relationship for tHi H2 second functional relationship for jiSoll jilst actual jerk jiMax maximum jerk jiSoll set jerk jiStart start jerk

J'T jerk limit

K AEBS cascade

K1 warning phase

K2 haptic warning phase

K3 emergency braking phase

Pi Position of the i-th vehicle 2i in the vehicle group 1

R haptic brake jolt

S data signal t time tl initial time tA response time tHi flaptic times tNi emergency braking times tR period vi actual vehicle speed

X lead vehicle

Y Follower vehicle z Final vehicle zNSet emergency braking request

STO, ST1, ST2, ST2.1, ST2.2, ST2.3, ST3, ST4, ST5, ST6, ST7, ST8

Claims

1. A method for coordinating vehicles (2i) of a vehicle group (1) while an emergency braking request (zNSoll) is present, the vehicles (2i) each having an electronically controllable braking system (8) to implement a requested target acceleration (aiSoll) taking into account a target jerk (jiSoll) and each vehicle (2i) is assigned a position (Pi) in the vehicle assembly (1), the target acceleration (aiSoll) for the respective vehicle (2i) depending on a manual or automated process triggered emergency braking request (zNSoll) is specified, with at least one AEBS cascade (K) in order to implement the emergency braking request (zNSoll) in the respective vehicle (2i) of the vehicle group (1)

- A first warning phase (K1) for the optical and / or acoustic warning of the driver of the respective vehicle (2i) of the vehicle group (1), and

- An emergency braking phase (K3) for braking the respective vehicle (2i) of the vehicle group (1) depending on the emergency braking requirement (zNSoll) taking into account the target jerk (jiSoll) at an emergency braking time (tNi) are provided, with at least one vehicle (2i) of the vehicle group (1) as part of the AEBS cascade (K) at a flaptic point in time (tHi) a haptic warning phase (K2) is provided in which the respective vehicle (2i) with a defined intermediate acceleration (aiZ ), which is less than the emergency braking request (zNSoll), in particular a haptic limit (aiH), is continuously delayed, characterized in that the flaptic point in time (tHi) to initiate the haptic warning phase (K2) and / or the target Jerk (jiSoll) to implement the emergency braking request (zNSoll) in the emergency braking phase (K3) are specified for each vehicle.

2. The method according to claim 1, characterized in that the haptic point in time (tHi) to initiate the haptic warning phase (K2) with continuous braking intervention at least for a leading vehicle (X) of the vehicle group (1) up to the emergency braking point (tNi ) to initiate the emergency braking phase (K3) for the leading vehicle (X) of the vehicle group (1) driving ahead can be delayed.

3. The method according to claim 1 or 2, characterized in that the haptic point in time (tHi) to initiate the haptic warning phase (K2) of the respective vehicle (2i) and / or the target jerk (jiSoll) to implement the emergency braking request (zNSoll ) in the emergency braking phase (K3) of the respective vehicle (2i) depending on the position (Pi) of the respective vehicle (2i) within the vehicle group (1).

4. The method according to claim 3, characterized in that the haptic point in time (tHi) to initiate the haptic warning phase (K2) with increasing position (Pi) in the vehicle group (1) decreases and / or the target jerk (jiSoll) for Implementation of the emergency braking request (zNSoll) in the emergency braking phase (K3) of the respective vehicle (2i) decreases with increasing position (Pi).

5. The method according to claim 3 or 4, characterized in that the target jerk (jiSoll) to implement the emergency braking request (zNSoll) in the emergency braking phase (K3) of the respective vehicle (2i) and / or the emergency braking time (tNi) as a function of a Actual following distance (dlstj) between the relevant vehicles (2i) of the vehicle group (1) is determined.

6. The method according to any one of the preceding claims, characterized in that the emergency braking time (tNi) for the respective vehicle (2i) as a function of the haptic time (tHi) and / or the position (Pi) of the respective vehicle (2i ) is specified within the vehicle association (1).

7. The method according to any one of the preceding claims, characterized in that in the first warning phase (K1) an energy- and wear-efficient adjustment of an actual distance (dlstj) between vehicles (2i) of the vehicle group (1) takes place, in particular by a electrical control of a drive system (7) of the respective vehicle (2i) for limiting or adapting a controlled engine torque.

8. The method according to any one of the preceding claims, characterized in that after the first warning phase (K1) and before the emergency braking phase (K3) at an initial point in time (tli) a haptic braking jolt (R) is generated in the respective vehicle (2i) where the initial point in time (tli) is dependent on the haptic point in time (tHi) for initiating the haptic warning phase (K2) and / or depending on the presence of the haptic warning phase (K2).

9. The method according to any one of the preceding claims, characterized in that at least the following steps are also provided:

- Implementation of the emergency braking request (zNSoll) in each vehicle (2i) of the vehicle group (1) by electrically actuating the brake system (8) of the respective vehicle (2i) taking into account the target jerk (jiSoll) as well as the specified vehicle-specific acceleration inclination parameters (Bi), the acceleration parameters (Bi) defining how the requested emergency braking request (zNSoll) is implemented (ST3);

- Observation of an actual driving dynamics (flst) of the vehicles (2i) of the vehicle group (1) during the implementation of the emergency braking request (zNSoll) taking into account the target jerk (jiSoll) and the vehicle-specific acceleration parameters (Bi) (ST4);

- Assessment of the observed actual driving dynamics (flst) of the vehicles (2i) based on the requested target acceleration (aiSoll) for the respective vehicle (2i) taking into account the target jerk (jiSoll) and the vehicle-specific acceleration parameters (Bi) and output ei nes vehicle-specific evaluation result (Ei) (ST5);

- Determination and output of an acceleration limit value (aT) and / or a jerk limit value (jT) as a function of the vehicle-specific evaluation result (Ei) (ST6) and adaptation of the vehicle-specific acceleration parameters (Bi) in at least one of the vehicles (2i) of the vehicle group (1) depending on the determined acceleration limit value (aT) and / or jerk limit value (jT) (ST7, ST8) to implement the emergency braking request (zNSoll) taking into account the adapted vehicle-specific acceleration parameters (Bi).

10. The method according to claim 9, characterized in that evaluating the observed actual driving dynamics (flst) includes comparing the actual driving dynamics (flst) with a target driving dynamics (fSoll) for the respective vehicle (2i) to determine whether the respective vehicle (2i) is able to achieve the target driving dynamics (fSoll), the target driving dynamics (fSoll) preferably by the emergency braking request (zNSoll) taking into account the target jerk (jiSoll) and the acceleration parameters (Bi ) is specified.

11. The method according to claim 9 or 10, characterized in that the vehicle-specific acceleration parameter (Bi) is a start acceleration (aiStart) for setting an initial intermediate acceleration (aiZ) of the respective vehicle (2i) in the haptic warning phase (K2) and / or a start jerk (jiStart) to adjust the intermediate acceleration (aiZ) in the direction of the requested emergency braking request (zNSoll) in the emergency braking phase (K3) can be specified in order to implement the requested emergency braking request (zNSoll) taking into account the acceleration parameters ( Bi) to implement.

12. The method according to any one of claims 9 to 11, characterized in that a maximum acceleration (aiMax) and / or a maximum jerk (jiMax) are specified as the acceleration parameter (Bi) to limit a currently requested intermediate acceleration (aiZ ) and / or the target jerk (jiSoll) at least when implementing the required emergency braking request (zNSoll) taking into account the vehicle-specific acceleration parameters (Bi) in the emergency braking phase (K3).

13. The method according to claim 12, characterized in that the maximum acceleration (aiMax) as a function of the determined acceleration limit value (aT) and / or the maximum jerk (jiMax) as a function of the jerk limit value (jT ) be adjusted.

14. The method according to claim 13, characterized in that the maximum acceleration (aiMax) as a function of the determined acceleration limit value (aT) and / or the maximum jerk (jiMax) as a function of the determined jerk limit value ( jT) can only be adapted for the vehicles (2i) of the vehicle group (1) which, when the emergency braking request (zNSoll) is specified, before the driving speed assigned to the acceleration limit value (aT) and / or the jerk limit value (jT) drive the vehicle (2i).

15. The method according to any one of claims 12 to 14, characterized in that the maximum acceleration (aiMax) and / or the maximum jerk (jiMax) of a vehicle (2i) as a function of a maximum drive capacity (AVMax) and / or a maximum braking capacity (BVMax) of one of the vehicles (2i) in the vehicle group (1) can be set and / or adjusted.

16. The method according to any one of claims 11 to 15, characterized in that the start jerk (jiStart) of the respective vehicle (2i) is set as a function of the position (Pi) of the vehicle (2i) within the vehicle group (1) the start jerk (jiStart) of the respective vehicle (2i) decreases with increasing position (Pi) within the vehicle group (1), the position (Pi) of the first vehicle (21) of the vehicle group (1) is less than the position (Pi) of the last vehicle (23) of the vehicle group (1).

17. The method according to any one of claims 9 to 16, characterized in that the observation of the actual driving dynamics (flst) the temporal observation of an actual vehicle speed (vi) of the respective vehicle (2i) and / or an actual acceleration (ailst) of the respective vehicle (2i) and / or an actual jolt (jilst) of the respective vehicle (2i) taking into account a response time (tA) and / or an actual distance (dlstj) between two vehicles (2i) of the vehicle group (1) and / or an actual distance change (dAlstj) in the actual distance (dlstj) between two vehicles (2i) of the vehicle group (1).

18. The method according to claim 17, characterized in that the vehicle-specific evaluation result (Ei) is formed as a function of whether - the actual vehicle speed (vi) of the respective vehicle (2i) remains constant, and / or

- the actual acceleration (ailst) of the respective vehicle (2i) remains constant or decreases in amount within a specified period (tR), the specified period (tR) depending on the target jerk (jiSoll) taking into account the response time (tA) is, and / or

- the actual distance (dlstj) between two vehicles (2i) remains constant or becomes smaller, and / or

- the actual distance change (dAlstj) is less than or equal to zero.

19. The method according to any one of claims 9 to 18, characterized in that the target acceleration (aiSoll) and / or the target jerk (jiSoll) and / or the vehicle-specific acceleration parameters (Bi) for the respective vehicle (2i) decentrally in the respective vehicles (2i) depending on data signals (S) transmitted wirelessly between the vehicles (2i) or centrally in one of the vehicles (2i).

20. The method according to any one of claims 9 to 19, characterized in that during the implementation of the emergency braking request (zNSoll), taking into account the target jerk (jiSoll) and the vehicle-specific acceleration parameters (Bi), it is checked whether the actual distance (dlstj) between the individual vehicles (2i) of the vehicle group (1) falls below a predetermined target distance (dSollj) for the respective vehicles (2i).

21.Steueinheit (4) for a vehicle (2i), which is in a Fahrzeugver bund (1), in particular for performing a method according to one of the preceding claims, wherein the control unit (4) is designed, the emergency braking request (zNSoll) as Target acceleration (aiSoll) in the respective vehicle (2i) of the vehicle federal government (1) by electrically actuating the brake system (8) of the respective vehicle (2i), whereby the target acceleration (aiSoll) for the respective vehicle (2i) can be specified as a function of a manually or automatically triggered emergency braking request (zNSoll) is, wherein the control unit (4) is designed in an AEBS cascade (K)

- To request a visual and / or acoustic warning to the driver of the respective vehicle (2i) of the vehicle group (1) in a first warning phase (K1), and

- In an emergency braking phase (K3) a braking of the respective vehicle (2i) of the vehicle group (1) as a function of the emergency braking request (zNSoll) taking into account the target jerk (jiSoll) to implement at an emergency braking time (tNi), the control unit ( 4) can implement a haptic warning phase (K2) for at least one vehicle (2i) of the vehicle group (1) as part of the AEBS cascade (K) at a haptic point in time (tHi), in which the respective vehicle (2i) also a defined intermediate acceleration (aiZ), which is less than the emergency braking request (zNSoll), can be continuously decelerated, characterized in that the control unit is designed to initiate the flaptic point in time (tHi) to initiate the haptic warning phase (K2) and / or to define the target jerk (jiSoll) for the implementation of the emergency braking request (zNSoll) in the emergency braking phase (K3) for a specific vehicle.

22. Vehicle (2i) with a control unit (4) according to claim 21.