Method, apparatus and computer program for forwarding message segments through a roadside infrastructure

Description

State of the art

[0001] The invention relates to a method, a device and a computer program for forwarding message segments through a location-based infrastructure.

[0002] Cooperative autonomous driving is based on the exchange of information between autonomous vehicles and local infrastructure. Messages for information exchange should be exchanged between road users as reliably as possible and without delay.

[0003] In certain situations, physical constraints make it error-prone or impossible to exchange messages directly between road users. Local infrastructure, particularly roadside infrastructure, can be used in these situations to relay messages. Relaying messages increases communication range and improves reliability through redundant transmissions. However, relaying messages increases the channel load in the communication channel, which in turn can reduce communication reliability and increase latency. Therefore, it is not always possible to relay all messages reliably and with the shortest possible delay, even with high communication volumes.

[0004] Document DE 10 2016 207 608 B3 discloses a method for a relay station for vehicle-to-vehicle messages. Here, a vehicle-to-vehicle message is filtered based on the relevance of the message to a recipient. If the message is not relevant to the recipient, it is filtered out and not forwarded.

[0005] Document WO 2017 / 045139 A1 discloses a method for transmitting communication messages. A message is transmitted from a first device via a radio node to a second device in an area with a weak radio signal. Disclosure of the invention

[0006] The method, the device and the computer program according to the independent claims improve communication.

[0007] The method for forwarding message segments by a location-based infrastructure facility that is designed to send messages to a plurality of sectors provides that an incoming message from a road user is received by the infrastructure facility, wherein an incoming message from a road user is received by the location-based infrastructure facility, wherein the incoming message comprises one message segment or several message segments, wherein either at least one sector from the plurality of sectors is determined for at least one message segment, and an outgoing message comprising the at least one message segment is sent by the location-based infrastructure facility to the at least one sector or the outgoing message is not sent if no sector has been determined, wherein several message segments from different incoming messages of a predetermined message type,that are to be sent in the same sector, in particular by means of data fusion, are combined into a single output message. This aggregates message segments that originate either from the same or from different road users.

[0008] Each message segment is sent in the sectors where it is relevant. Forwarding message segments to sectors where they are not relevant is avoided. This reduces communication traffic and increases the reliability of the communication channel compared to forwarding messages without relevance checks. A location-based infrastructure facility can be understood as a stationary, particularly roadside, infrastructure facility.

[0009] The at least one sector is preferably determined depending on the position of an infrastructure element, in particular a building, a roadway, a traffic sign, and / or a dynamic state of the road user in an environment of the fixed infrastructure facility, in which sending the incoming message by the road user is error-prone or impossible. This means that the relevant sectors are determined depending on the dynamic state, for example, the position, orientation, and / or speed of the road user. This reduces the communication volume to sectors that are difficult or impossible to reach by direct communication by the road user.

[0010] Preferably, the location of the infrastructure element relative to the road user is determined using an environmental model that includes a map of the surroundings of the fixed infrastructure facility. This allows the relevant sectors to be determined particularly reliably.

[0011] Preferably, a road user's position is detected by a sensor of the infrastructure facility or received in a message, particularly from the road user, and stored in the environmental model. In other words, the road user's position detected by the sensor of the infrastructure facility or transmitted in a message, particularly from the road user to the infrastructure facility, is stored in the environmental model. This allows the relevant sectors to be determined particularly reliably.

[0012] Preferably, a relevance of the sector for the message segment is determined, wherein the message segment is sent to the sector if the relevance of the sector for the message segment fulfills a condition, in particular exceeds a threshold, and wherein the message segment is otherwise not sent to the sector. This significantly reduces the communication volume in the sector.

[0013] Preferably, a reception probability is determined that the message can be received by the recipient, particularly depending on the distance of a recipient from the road user and the position of an infrastructure element, in particular a building, a roadway, a traffic sign, a dynamic state of the road user, and / or a dynamic state of the recipient in the surroundings of the fixed infrastructure facility. The relevance of the sector for the message segment is determined based on the reception probability. As a result, the message segment is only forwarded if the road user cannot reach the recipient directly with a sufficiently high probability. This reduces the communication volume for each recipient.

[0014] Preferably, a potential benefit for receiving the message segment is determined, particularly depending on the time until a collision between a receiver and the road user, the distance to the road user, or the type of road user and / or the receiver. The relevance of the sector for the message segment is determined based on the potential benefit. This avoids a reduction in the communication volume for the specific receiver if the message segment is highly relevant, for example, for the safety of the receiver.

[0015] The relevance of the sector is preferably determined depending on a particularly weighted difference or division between the potential benefit and the probability of reception.

[0016] The difference or division is preferably determined depending on a possible benefit and a reception probability determined for at least one other receiver currently located in the sector.

[0017] Preferably, including the message segment, a plurality of message segments are determined whose relevance to the sector satisfies the condition, wherein the output message comprises at least the message segment and one further message segment from the plurality of message segments, or wherein the output message does not comprise at least one further message segment from the plurality of message segments that is redundant to the message segment, or wherein the output message does not comprise at least one further message segment from the plurality of message segments that comprises similar or the same content as the message segment. This further reduces the volume of communication.

[0018] Preferably, one of several message segments from different input messages of a given message type that are to be sent in the same sector is sent in the output message, while the others are discarded. This further reduces the communication traffic.

[0019] The device for forwarding message segments through a location-based infrastructure, which is designed to send messages to a plurality of sectors, is designed, in particular configured, to carry out the method.

[0020] The system for forwarding message segments comprises a plurality of such devices, which are interconnected, in particular via a wired data line, and are configured to exchange incoming messages with each other via the data line. An incoming message received at one of the devices is forwarded via the data line to at least one other of the devices. As a result, recipients outside the radio range of the fixed infrastructure device can also be reached via the fixed infrastructure device that receives the incoming message from the road user.

[0021] The computer program comprises computer-readable instructions, the execution of which by a computer or a device described above carries out the method according to the invention.

[0022] Further advantageous embodiments will become apparent from the following description and the drawing. The drawing shows: Fig. 1 a message, Fig. 2 a device for forwarding message segments, Fig. 3 a sequence diagram of a communication, Fig. 4 a scenario for forwarding message segments.

[0023] In Figur 1 A message 100 is schematically shown, which includes a message segment 102. Multiple message segments can also be provided in the message 100. The message 100 can be an input message or an output message.

[0024] In Figur 2 A device 200 for forwarding message segments and a location-based infrastructure 202 are schematically illustrated. In the example, the location-based infrastructure 202 comprises the device 200. The location-based infrastructure 202 is configured to send messages to a plurality of sectors. Preferably, the location-based infrastructure 202 is a roadside infrastructure 202. In the example, eight sectors 204-1, 204-2, 204-3, 204-4, 204-5, 204-6, 204-7, 204-8 are illustrated. More or fewer sectors may be provided.

[0025] The device 200 comprises a processor 206 and a memory 208. The device 200 is designed to be described below with reference to Figur 3 to execute the method described. In the example, memory 208 includes computer-readable instructions, the execution of which by processor 206 executes the method. A distributed computer architecture with a plurality of processors and / or memories may also be provided.

[0026] In the example for driver information or warnings, communication takes place in the 5.9 GHz frequency band as V2X according to the IEEE 802.11p standard, known in the USA as DSRC and in Europe as ITS-G5. Communication can also be provided, for example, according to IEEE 802.11bd, or according to 3GPP Specification C-V2X or 5G New Radio (NR) V2X Release 16. NR V2X.

[0027] In the example, the location-based infrastructure 202 has sector-specific antennas that are designed to transmit the output message in the method to one of the sectors or to several of the sectors.

[0028] The sector-specific antennas are designed to receive the incoming message, in particular from a road user 210 or another (in Figur 2 not shown) location-based infrastructure 202. In this context, input message refers to a message sent by road user 210.

[0029] A receiver 212 located in one of the sectors is configured to receive the output message. Output message, in this context, refers to a message sent by the location-based infrastructure 202.

[0030] In the example, the receiver 212 is also designed to receive the incoming message, ie the message sent by the road user 210.

[0031] Whether and how well the receiver 212 can receive the incoming message or the outgoing message depends on an environment 214 in which the receiver 212, the road user 210 and the location-based infrastructure 202 are located, and on how they are arranged relative to one another.

[0032] The method for forwarding message segments provides that the location-based infrastructure device 202 is designed to send messages to a plurality of sectors, for example the eight sectors 204-1, 204-2, 204-3, 204-4, 204-5, 204-6, 204-7, 204-8.

[0033] The method optionally includes a step 300. In step 300, the position of road user 210 is received in a message from road user 210. Alternatively, the position may be detected using a sensor of the stationary infrastructure facility 202. Alternatively, the position may be detected using another sensor and transmitted in a message to the stationary infrastructure facility 202. For example, this message may be transmitted by another vehicle that has detected road user 210.

[0034] Step 300 can be performed repeatedly. Thus, the location-based infrastructure facility 202 is informed of the position of the road user 210, for example, during a time interval in which the road user 210 is in the vicinity of the infrastructure facility 202.

[0035] The method comprises a step 302. In step 302, an input message from road user 210 is received by infrastructure facility 202. It may be provided that the position of road user 210 is included in the input message and that steps 300 and 302 take place together.

[0036] The input message is structured, for example, as described for message 100. The input message comprises one or more message segments.

[0037] A step 304 is then executed.

[0038] In step 304, one sector from the plurality of sectors is determined for the message segment. It may be provided that multiple sectors are determined from the plurality of sectors.

[0039] In Figur 4 An example of a scenario is shown in which sending to sector 204-1 is error-prone or impossible.

[0040] The sector 204-1 is determined, for example, depending on a position of an infrastructure element, in particular a building 402, a roadway 404, a traffic sign, and / or a position of the road user 210 in an environment 406 of the local infrastructure facility 202, in which a transmission of the incoming message by the road user 210 is error-prone or impossible. Figur 4 Other road users 408 are also shown. These may be other possible recipients.

[0041] In the example, an arrangement of the infrastructure element relative to the road user 210 is determined using an environment model that includes a map of the environment of the location-based infrastructure 202.

[0042] In the example, in particular, depending on a distance of the receiver 212 from the road user 210, a reception probability is determined that the message can be received by the receiver.

[0043] In the example, a possible benefit for sending the message segment to the recipient 212 is determined, in particular depending on a time until a possible collision between the recipient 212 and the road user 210.

[0044] In the example, the relevance of the sector for the news segment is determined. It may be possible to have multiple news segments, and the relevance of the sector is determined for each of them. In the example, the relevance of the sector for the news segment is determined based on the probability of reception and the potential benefit. It may also be possible to determine the relevance of the sector based on the probability of reception and independently of the potential users. It may also be possible to determine the relevance of the sector based on the potential benefit and independently of the probability of reception.

[0045] It may be provided that the relevance of the sector is determined depending on a particularly weighted difference or division between the potential benefit and the reception probability. It may be provided that the difference or division is determined depending on the potential benefit and the reception probability that has been determined for at least one other receiver 408 currently located in the sector.

[0046] For example, for a plurality of message segments i and a plurality of recipients j, a respective relevance R i,j with a respective reception probability P i,j a respective possible benefit B i,j .

[0047] For example, for each message segment i and recipient j, the possible benefit B i,j is determined to be inversely proportional to the time until collision between an area relevant to message segment i and receiver j. In the example, the area is defined as the region about which the message segment has information. This can be an area in which a detected object is located or an area in which a trajectory of the detected object is located.

[0048] In the example, the time to collision (TTC) is determined as the time until the receiver first enters the area based on its current dynamic status. Dynamic status in this context refers to, for example, the position, heading, speed, acceleration, and / or yaw rate of receiver j.

[0049] The earlier a receiver j enters the area, the greater the possible benefit in the example B i,j .

[0050] An estimate of this time, in particular of a worst-case scenario, may also be provided, particularly in the case where a standard deviation after a sensor data fusion is greater than zero.

[0051] The possible benefits B i,j can also be determined depending on the distance between the area and the receiver j. The possible benefit B i,j can also be determined depending on the type of the sending road user and / or the receiver j. For example, a particularly fast vehicle is given a higher potential benefit B i,j assigned to a pedestrian. The possible benefit B i,j can also be determined depending on the distance between the sending road user and the road user closest to it (or the TTC between the two). The potential benefit B i,j can also be determined as a combination of these factors.

[0052] For example, for each message segment i and recipient j, the probability P i,j depending on whether there is a line of sight between them or not. It can also be provided that the probability P i,j is determined depending on the utilization of a communication channel at the position of receiver j. The utilization is determined, for example, by information about currently used communication channels or receipt confirmation messages from receiver j or other communication participants.

[0053] The relevance R i,j is, for example, expressed as a function with a positive correlation to the estimated potential benefit B i,j and negative correlation to

[0054] Probability of reception P i,j For example, the relevance R i,j determined as: R i , j = w 1 B i , j − w 2 P i , j or as: R i , j = B i , j w 1 / P i , j w 2 where w 1 and w 2 positive weight factors.

[0055] These weighting factors allow for the relative importance of the benefit and the probability of receipt to be taken into account. A larger value of w 1 results in a lower value of w 1 and / or w 2 more transmissions of message segments relevant to road users who are close to the transmitting road user. A larger value of w 2 results in a lower value of w 2 and / or w 1 more transmissions of message segments to receivers further away from the sending road user, since the probability of reception is greater.

[0056] It may be intended to summarize the relevance of a news segment for all road users relevant to a sector i R i = Σ R i,j and with a threshold R th to compare. The threshold R th can be determined depending on factors such as road topology at the local infrastructure 202, traffic density in the area, or the utilization of the communication channel. The road topology can be defined, for example, by the presence of an intersection or a motorway entrance.

[0057] The threshold R th can be determined using a machine learning algorithm that uses the parameters described above and is trained to optimize traffic safety or efficiency measured by the location-based infrastructure 202. For example, in a scenario with a high risk of collision, a low threshold R th used and the threshold R th increases as the utilization of the communication channel increases.

[0058] For example, the sector is recognized as a relevant sector for a news segment if R i > R th .

[0059] The method may provide that relevant sectors are determined for the plurality of message segments i, and the message segments relevant to the sector are summarized and sent in an output message.

[0060] A step 306 is then executed.

[0061] In step 306, the infrastructure device 202 sends an output message comprising the message segment to the sector.

[0062] In the example, the news segment is sent to the sector if the relevance R i of the sector for the news segment meets a condition, in particular the threshold R th Otherwise, the message segment in the example will not be sent to the sector.

[0063] It can be provided that, including the message segment, a plurality of message segments are determined whose relevance to the sector meets the condition. The message segments can have been sent by the same sender or by different senders. In this case, it can be provided that the output message comprises at least the message segment and one further message segment from the plurality of message segments.

[0064] It can be provided that in this case, the output message does not include at least one additional message segment from the plurality of message segments that is redundant to the message segment. It can be provided that two or more redundant message segments are combined into a new message segment, e.g., by means of data fusion.

[0065] In this case, the output message may not include at least one further message segment from the plurality of message segments that contains similar or identical content to the message segment. It may be provided that two or more similar message segments are combined into a new message segment, e.g., by means of data fusion.

[0066] It may be provided to aggregate message segments that originate either from the same or from different road users. For example, the method provides for combining several message segments from different input messages of a given message type that are to be sent to the same sector into one output message, in particular by means of data fusion.

[0067] It may be provided to further reduce the communication volume by sending one of several message segments of different input messages of a given message type that are to be sent in the same sector in the output message, with the others being discarded.

[0068] To increase the range, a system for forwarding message segments can be provided, the system comprising a plurality of devices 200.

[0069] The devices 200 are connected to each other via a data line. The data line can be wired. The devices 200 are configured to exchange input messages with each other via the data line.

[0070] In the example, an input message arriving at one of the devices 200 is forwarded via the data line to at least one other of the devices 200.

[0071] Preferably, the data line connects devices provided in adjacent local infrastructure facilities 202.

Claims

1. Method for forwarding message segments by way of a fixed infrastructure facility (202) designed to send messages to a plurality of sectors (204-1, ..., 204-8), wherein an incoming message from a road user (210) is received by the fixed infrastructure facility (202) (302), the incoming message comprising a message segment or multiple message segments, wherein either at least one sector from the plurality of sectors (204-1, ..., 204-8) is determined for at least one message segment (304), and the fixed infrastructure facility (202) sends an outgoing message comprising the at least one message segment to the at least one sector (306), or the outgoing message is not sent if no sector has been determined, characterized in that multiple message segments of different incoming messages of a predefined message type which are to be sent to the same sector are combined into an outgoing message, in particular by means of data fusion.

2. Method according to Claim 1, characterized in that the at least one sector to which sending of the incoming message by the road user (210) is prone to errors or impossible is determined on the basis of a position of an infrastructure element, in particular a building (402), a road (404), a traffic sign and / or a dynamic state of the road user (210) in an environment (406) of the fixed infrastructure facility (202).

3. Method according to Claim 2, characterized in that an arrangement of the infrastructure element relative to the road user (210) is determined using an environmental model (304) comprising a map of the environment of the fixed infrastructure facility (202).

4. Method according to Claim 3, characterized in that a position of the road user (210) is detected using a sensor of the fixed infrastructure facility (202) or received in a message in particular from the road user (210) and stored in the environmental model (300).

5. Method according to one of the preceding claims, characterized in that a relevance of the sector to the message segment is determined (304), the message segment being sent to the sector (306) if the relevance of the sector to the message segment satisfies a condition, in particular exceeds a threshold value, otherwise the message segment is not sent to the sector.

6. Method according to Claim 5, characterized in that in particular a distance of a receiver (212) from the road user (210) and a position of an infrastructure element, in particular a building (402), a road (404), a traffic sign, a dynamic state of the road user (210) and / or a dynamic state of the receiver (212) in an environment (406) of the fixed infrastructure facility (202) are taken as a basis for determining a reception probability of the message being receivable by the receiver (212), the relevance of the sector to the message segment being determined on the basis of the reception probability (304).

7. Method according to Claim 5 or 6, characterized in that in particular a time before a collision between a receiver (212) and the road user (210), a distance from said road user or a type of the road user (210) and / or of the receiver (212) is taken as a basis for determining a possible benefit of the message segment being received by the receiver (212), the relevance of the sector to the message segment being determined on the basis of the possible benefit (304).

8. Method according to Claim 7, characterized in that the relevance of the sector is determined on the basis of an in particular weighted difference or division between the possible benefit and the reception probability.

9. Method according to Claim 8, characterized in that the difference or division is determined on the basis of a possible benefit and a reception probability which has been determined for at least one further receiver (408) currently located in the sector.

10. Method according to one of the preceding claims, characterized in that, including the message segment, a plurality of message segments whose relevance to the sector satisfies the condition are determined (304), wherein the outgoing message comprises at least the message segment and a further message segment from the plurality of message segments or wherein the outgoing message does not comprise at least one further message segment from the plurality of message segments which is redundant with respect to the message segment or wherein the outgoing message does not comprise at least one further message segment from the plurality of message segments which comprises a content similar to or the same as that of the message segment.

11. Method according to one of the preceding claims, characterized in that, of multiple message segments of different incoming messages of a predefined message type which are to be sent to the same sector, one is sent in the outgoing message, the others being discarded.

12. Device (200) for forwarding message segments by way of a fixed infrastructure (202) designed to send messages to a plurality of sectors (204-1, ..., 204-8), characterized in that the device (200) is designed to carry out the method according to one of Claims 1 to 11.

13. System for forwarding message segments, characterized in that the system comprises a plurality of devices (200) according to Claim 12 which are connected to each other by an in particular wired data line and are designed to exchange incoming messages with each other via the data line, an incoming message which arrives at one of the devices (200) being forwarded to at least one other of the devices (200) via the data line.

14. Computer program, characterized in that the computer program comprises computer-readable instructions which, when executed by a computer or a device (200) according to Claim 12, result in a method according to one of Claims 1 to 11 being carried out.