DE102021212885A1 - Method of sending vehicle-to-X messages and vehicle-to-X communication module - Google Patents

Abstract

The invention relates to a method for a subscriber to send vehicle-to-X messages, with objects being detected and prioritized and vehicle-to-X information containing information about the objects being sent at a transmission rate that is dependent on the priority . The invention further relates to a vehicle-to-X communication module for executing such a method.

Description

The invention relates to a method for a subscriber to send vehicle-to-X messages and to a vehicle-to-X communication module for carrying out such a method.

Vehicle-to-X communication is currently under development and in the initial market launch. Typically, information is exchanged between vehicles and also between vehicles and infrastructure, which contains, for example, information about other vehicles, other objects, the traffic situation or particular hazards. This can significantly increase road safety.

Certain messages can be intended to contain information about objects detected in the area surrounding a vehicle, which can thus also be made available to other road users.

It is an object of the invention to provide a method for sending vehicle-to-X messages which is implemented alternatively or better compared to known implementations. It is a further object of the invention to provide an associated vehicle-to-X communication module. According to the invention, this is achieved by a method and a vehicle-to-X communication module according to the respective main claims. Advantageous configurations can be found, for example, in the respective dependent claims. The content of the claims is made part of the content of the description by express reference.

• - Erfassen von Objekten in einer Umgebung des Teilnehmers und basierend darauf Erzeugen von Informationen zu jedem Objekt,
• - Zuweisen einer Priorität zu jedem Objekt, und
• - Senden von Fahrzeug-zu-X-Nachrichten enthaltend die Informationen,
• - wobei eine jeweilige Senderate, mit welcher Nachrichten gesendet werden, welche Informationen zu einem jeweiligen Objekt enthalten, von der Priorität des Objekts abhängt.

The invention relates to a method for sending vehicle-to-X messages by a subscriber, the method having the following steps:

• - detecting objects in a participant's environment and based thereon generating information about each object,
• - Assign a priority to each object, and
• - sending vehicle-to-X messages containing the information,
• - A respective transmission rate, with which messages are sent, which contain information about a respective object, depends on the priority of the object.

The method according to the invention enables a prioritization of recognized objects, so that transmission rates can be adjusted accordingly. In the case of high-priority objects, which for example pose an immediate danger to other road users, the transmission rate can be increased in comparison to other objects, and a lower transmission rate can be selected in the case of uncritical objects. As a result, bandwidth is saved overall and reliable and sufficient information about relevant objects is nevertheless provided.

Objects can be, for example, vehicles, obstacles, pedestrians, or other objects. For example, the priority may be assigned based on factors discussed below. Information about an object that may be included in a vehicle-to-X message may include its location, speed, direction, and/or type, for example. A transmission rate can be understood in particular as how often a message with corresponding information is transmitted in a time unit of, for example, one second or one minute.

The participant in the vehicle-to-X communication can be, for example, a roadside device such as a traffic light or a roadside unit. These typically have a particularly good overview of the traffic situation. However, it can also be a vehicle or another road user.

A given object's priority may be assigned based on a change in its speed and/or course, for example. A change can be, for example, a first time derivative of the respective variable. In this way, account can be taken in particular of the fact that an object whose speed and/or course does not change does not necessarily have to be communicated again, since it is sufficient if another participant has received information about it once and is therefore able to do so is to calculate the current location or other value in advance. Only when speed and/or course change is this no longer the case and new information is appropriate.

In particular, the priority of a respective object can be assigned based on a type of the object. In this way, for example, the fact can be taken into account that certain objects such as broken-down vehicles or pedestrians on the road have a particularly high risk potential, whereas normally driving vehicles or accident sites on a hard shoulder have a lower risk potential.

In particular, the priority of a given object may be assigned based on a difference between its speed and one or more speeds of other objects. As a result, for example, the priority of an object that moves particularly quickly in comparison to other objects can be increased, so that information about this relatively more dangerous object is provided particularly frequently.

In particular, the priority of a respective object can be assigned based on a change in its acceleration. This is based on the idea already explained above. If the acceleration of an object is known and does not change, a prediction can be made. However, if the acceleration changes, new information about this is displayed.

In particular, the priority of a respective object can be assigned based on a change in its rate of rotation. Here, too, account can be taken of the fact that a change in the yaw rate makes a precalculation more difficult or impossible when information has already been received and new information is displayed.

The priority of a respective object can be assigned in particular based on a change in at least one piece of information about the object. This can be understood as a general formulation. In particular, a priority can therefore be increased in particular when information about the object changes, since this change is typically not yet known to other participants in the vehicle-to-X communication and information about it is therefore displayed.

The priority of a respective object can be assigned in particular based on how long ago the object was detected. For example, a low priority can be used for detections made some time ago in order to send newly detected objects more frequently.

The priority of a respective object can be assigned in particular on the basis of a recognized turning request of the object. As a result, for example, the priority can be increased in the case of objects signaling a turn request, since these typically have a higher risk potential. The wish to turn can be displayed, for example, by a blinker, in particular an optical display device, and/or by a vehicle-to-X message.

The priority of a respective object can be assigned in particular based on a recognized or calculated accident risk of the object. As a result, the higher the risk of an accident, the higher the priority can be selected.

In particular, the priority of a respective object can be assigned based on a number of received information about the object. In particular, the more information about the object has already been received, the lower the priority can be assigned. This can be viewed in absolute terms and/or in a defined unit of time. It can thus be taken into account that an object that has already been detected and made known by other vehicle-to-X communication participants no longer needs to be made known as frequently. In particular, the information about the object can be received using vehicle-to-X communication.

A respective transmission rate can in particular be all the higher, the higher the priority of the object. Thereby the sending rate can be suitably controlled. For example, the relationship can be linear, progressive, degressive or otherwise.

In particular, the transmission rate can also depend on a channel load. In this way, the channel load can also be taken into account, so that overall there is good, but not excessive, utilization of the available bandwidth.

In particular, the amount of information about at least one object that is sent can depend on the priority. This means that not only the sending rate, but also the use of data can be controlled depending on the priority. In particular, the higher the priority of an object, the more information can be sent. This embodiment can also be understood as an alternative to varying the transmission rate, which represents an independent aspect of the invention.

In particular, the information about one, some or all objects can contain a position, a course, a speed and/or an acceleration. Such information has proven to be advantageous for increasing road safety. However, other information can also be used.

The objects can be detected in particular by means of one or more environment sensors, radar devices, cameras, contact loops and/or distance sensors. Such sensors are typically good at detecting objects such as other vehicles or pedestrians. However, other sensors can also be used.

The vehicle-to-X messages containing the information can in particular be cooperative perception messages. However, other types of messages can also be used.

The invention further relates to a vehicle-to-X communication module configured to perform a method as described herein. With regard to the method, all of the versions and variants described herein can be used. In particular, the vehicle-to-X communication module can have processor means and storage means, with program code being stored in the storage means, when the processor means execute a method according to the invention.

The invention also relates to a non-transitory computer-readable storage medium which contains program code which, when executed, causes a processor to carry out a method according to the invention. With regard to the method, all of the versions and variants described herein can be used.

In vehicle-to-X communication in particular, it is becoming increasingly necessary to sensibly control the occupancy of existing channels and, in particular, to reduce them where possible.

For example, Collective Perception Messages (CPM) can be used to provide information about surrounding objects. This means that each recipient can be provided with additional information about the environment. For this purpose, for example, information about the environment recognized by the transmitter is sent, colloquially expressed "I saw the following".

This information is particularly interesting when it is not so easy to predict.

For each object detected with the environment sensors, it can be checked in particular how much the dynamics have changed and/or how much the dynamics differ from the other objects in the environment and/or how vulnerable the object is, for example classified according to object type and accident risk.

In this case, dynamics are understood to mean, for example, speed, acceleration, alignment, yaw rate or other parameters. The recognized objects are sorted on the basis of the dynamic changes or the difference in dynamics to other objects in the vicinity. Objects that are higher up the list, i.e. have a large change in dynamics or whose dynamics are very different from objects in the surrounding area, will send out CPMs more frequently than objects further down the list. The total number of sent CPMs or objects in CPMs is expediently adapted to the channel load. As a result, newly detected objects are at the top of the list.

If objects are detected by the ego vehicle that are not contained in the CPMs of the received messages, these are given a high priority even if the dynamic changes are small.

A special case can be a two-wheeler as an object. For example, this can be a bicycle, a motorcycle or a scooter. If a sensor such as a radar detects a turn request based on a micro-Doppler change that indicates a change in direction, this is already classified as a dynamic change.

For objects that are further down the list, the information sent or the object description can also be reduced. For example, only the position and the object type can be sent. This means that more objects can be transmitted at the same data rate, but with a reduced amount of information. In combination with the selection based on the dynamics, the information about the overall situation is retained.

Another criterion for determining the sending rate of objects can be the vulnerability of objects.

• - Fußgänger, Fahrradfahrer, Scooter, Roller > Motorradfahrer > Busse > PKW > LKW
• - Kinder > Erwachsene.

For example, the sending rate of objects can be increased if they are classified as particularly vulnerable. The classification of the object types within the scope of their vulnerability can be based on the following criteria, for example:

• - Pedestrians, cyclists, scooters, scooters > Motorcyclists > Buses > Cars > Trucks
• - Children > Adults.

Since the classification of the vulnerability can often contradict the classification of the object according to dynamic change, the following procedure is also proposed: The sending rate of objects can be increased if the situation for the detected object, especially a vulnerable one, is classified as relevant to an accident. For example, pedestrians or cyclists in the immediate vicinity of a car, truck or bus can be classified as particularly vulnerable. Motorized vehicles requesting a turn in the direction of parallel, oncoming traffic or crossing pedestrians, and cyclists in the immediate vicinity of the motorized vehicle can be classified as particularly vulnerable. Dynamic objects, especially objects classified as vulnerable that are in the vicinity of vehicles with longer braking distances (such as trams, buses, loaded trucks, etc.), can be classified as particularly vulnerable. The situation can be classified as a danger, for example, on the basis of a collision risk that has been determined. It can also be considered when an object is in a blind spot of another vehicle, in which case the priority can also be increased.

• 1: ein Fahrzeug mit umgebenden Objekten, und
• 2: eine Ampel mit umgebenden Objekten.

The person skilled in the art will find further features and advantages in the exemplary embodiments described below with reference to the attached drawing. It shows:

• 1 : a vehicle with surrounding objects, and
• 2 : a traffic light with surrounding objects.

1 shows a vehicle 10 in a purely schematic view. The vehicle 10 represents a participant in the vehicle-to-X communication and has a vehicle-to-X communication module 20 according to an embodiment of the invention. An antenna 22 is connected to it. With this, the vehicle 10 can participate in the vehicle-to-X communication.

The vehicle 10 also has a camera 30 . This is shown here by way of example for one or more surroundings sensors of vehicle 10, vehicle 10 being able to perceive its surroundings by means of camera 30 or also by means of other sensors, that is to say it can record its surroundings.

A total of three objects 50, 52, 54 are shown here. The object 50 is another vehicle that follows its own trajectory. Object 52 is a permanently installed post on the side of a road. In the present case, the object 54 is a pedestrian.

In the case of the other vehicle 50, sensor information is used to identify the course it is traveling on and the speed at which it is traveling. If a change is detected in the process, i.e. the course or speed change, the priority of the other vehicle 50 is increased compared to a normal value for a certain period of time.

Post 52 is not expected to move since it is fixed. This basically gets a low priority.

Pedestrian 54, who is currently on the street and in a possible driving area of vehicle 10, is particularly vulnerable, which can be recognized by appropriate image recognition. It therefore always has the highest priority.

Information about the three detected objects 50, 52, 54 is sent at a respective sending rate that depends on the priority. In the example shown, information regarding the pedestrian 54 is always sent at the highest sending rate. Information regarding the post 52 is always sent at the lowest send rate. Information regarding the other vehicle 50 is transmitted at a transmission rate that depends on whether the other vehicle 50 has just changed course and/or speed. After a predefined period of time, the priority can be reduced again if the course and/or speed no longer change.

2 shows an alternative implementation. Instead of a vehicle 10, the vehicle-to-X participant, which controls its transmission rates based on priorities, is now a traffic light 15.

The traffic light 15 is installed, in particular, at elevated points, so that it has a better overview of the traffic situation than the vehicle 10 . In this way, other participants in the vehicle-to-X communication can be informed even better.

Otherwise, regarding the functionality, refer to the description of 1 referred.

In general, it should be pointed out that vehicle-to-X communication means, in particular, direct communication between vehicles and/or between vehicles and infrastructure devices. For example, it can be vehicle-to-vehicle communication or vehicle-to-infrastructure communication. If reference is made to communication between vehicles in the context of this application, this can in principle take place, for example, in the context of vehicle-to-vehicle communication, which typically takes place without mediation through a mobile network or a similar external infrastructure and which is therefore different from other solutions , which are based, for example, on a cellular network. For example, vehicle-to-X communication can occur using the IEEE 802.11p or IEEE 1609.4 standards. Other examples of communication technologies include LTE-V2X, 5G-V2X, C-V2X, WLAN, WiMax, UWB or Bluetooth. Vehicle-to-X communication can also be referred to as C2X communication. The sub-areas can be referred to as C2C (Car-to-Car) or C21 (Car-to-Infrastructure). However, the invention does not explicitly exclude vehicle-to-X communication with switching, for example via a mobile radio network.

Mentioned steps of the method according to the invention can be carried out in the order given. However, they can also be executed in a different order, as far as this is technically reasonable. In one of its implementations, for example with a specific combination of steps, the method according to the invention can be carried out in such a way that no further steps are carried out. In principle, however, further steps can also be carried out, including those which are not mentioned.

It should be noted that in the claims and in the description features can be described in combination, for example to facilitate understanding, although they can also be used separately. The person skilled in the art recognizes that such features can also be combined independently of one another with other features or combinations of features.

Back-references in dependent claims can identify preferred combinations of the respective features, but do not exclude other combinations of features.

Reference List

10

vehicle / participant

15

traffic light / participant

20

Vehicle-to-X communication module

22

antenna

30

camera

50

other vehicle/object

52

post / object

54

pedestrian / object

Claims (18)

A method for sending vehicle-to-X messages by a subscriber (10, 15), the method comprising the steps of: - detecting objects (50, 52, 54) in an environment of the participant (10), and based thereon generating information about each object (50, 52, 54), - assigning a priority to each object (50, 52, 54), and - sending vehicle-to-X messages containing the information, - A respective sending rate, with which messages are sent containing information about a respective object (50, 52, 54), depends on the priority of the object (50, 52, 54). procedure after claim 1 , - wherein the priority of a respective object (50, 52, 54) is assigned based on a change in its speed and/or course. Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a type of the object (50, 52, 54). Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a difference between its speed and one or more speeds of other objects (50, 52, 54). Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a change in its acceleration. Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a change in its rotation rate. Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a change in at least one piece of information about the object (50, 52, 54). Method according to one of the preceding claims, - The priority of a respective object (50, 52, 54) being assigned based on how long ago the object (50, 52, 54) was recognized. Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a recognized turning request of the object (50, 52, 54). Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a recognized or calculated risk of the object (50, 52, 54) falling over. Method according to one of the preceding claims, - wherein the priority of a respective object (50, 52, 54) is assigned based on a number of received information about the object (50, 52, 54). Method according to one of the preceding claims, - A respective transmission rate is higher, the higher the priority of the object (50, 52, 54). Method according to one of the preceding claims, - where the transmission rates also depend on a channel load. Method according to one of the preceding claims, - wherein the amount of information about at least one object (50, 52, 54) that is sent depends on the priority. Method according to one of the preceding claims, - wherein the information on one, some or all of the objects (50, 52, 54) includes a position, a course, a speed and/or an acceleration. Method according to one of the preceding claims, - The objects (50, 52, 54) being detected by means of one or more environment sensors, radar devices, cameras (30), contact loops and/or distance sensors. Method according to one of the preceding claims, - wherein the vehicle-to-X messages containing the information are Cooperative Perception Messages. A vehicle-to-X communications module (20) configured to perform a method as claimed in any preceding claim.

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