DE102022204678B4 - Method for providing distance information - Google Patents

Abstract

The invention relates to a method for providing distance information to a vehicle-to-X participant, wherein a first distance is determined based on a distance measurement and a second distance is determined based on location information, and distance information is provided depending on a comparison of the two distances.

Description

The invention relates to a method for providing distance information to a vehicle-to-X subscriber.

Vehicle-to-X communication enables the exchange of various data, for example regarding the movement of vehicles or a traffic situation, between motor vehicles and infrastructure units. Vehicle-to-X messages can generally contain location information. Together with another location, which can be determined by an ego vehicle itself, for example, a distance to another vehicle-to-X participant can thus be determined. However, such distance determinations can be subject to uncertainty.

The disclosure document DE 10 2016 103638 A1 refers to determining the status of road users who have been involved in an accident and warning other road users via C2X communication. The absolute position of a vehicle can be determined by using emitted signals, for example using Trillian modulation or other environmental detection means such as cameras, radar or ultrasonic sensors. A cell phone sends its position to the vehicle, in this case a motorcycle. The distance between the mobile phone, i.e. its driver, and the motorcycle can then be calculated.

The disclosure document WO 2021/047923 A1 refers to determining an ego position. A position recorded via GNSS is transmitted using V2X communication. The distance of the determined position to receive position information is determined. Accuracy can be measured using confidence information.

It is therefore an object of the invention to provide a method for providing distance information, which is designed alternatively or better than known embodiments. This is achieved according to the invention by a method according to claim 1. Advantageous refinements can be found, for example, in the subclaims. The content of the claims is made the content of the description by express reference.

• - Empfangen einer Fahrzeug-zu-X-Nachricht, welche eine Ortsinformation über einen externen Fahrzeug-zu-X-Teilnehmer beinhaltet,
• - Durchführen einer Entfernungsmessung zur Bestimmung einer ersten Entfernung zu dem externen Fahrzeug-zu-X-Teilnehmer,
• - Berechnen einer zweiten Entfernung zwischen dem Fahrzeug-zu-X-Teilnehmer und dem externen Fahrzeug-zu-X-Teilnehmer basierend auf der Ortsinformation über den externen Fahrzeug-zu-X-Teilnehmer,
• - Vergleichen der ersten Entfernung mit der zweiten Entfernung, und abhängig davon
  • - Bereitstellen der ersten Entfernung und/oder der zweiten Entfernung als Entfernungsinformation,
  • - Bereitstellen eines aus der ersten Entfernung und/oder der zweiten Entfernung berechneten Werts als Entfernungsinformation, oder
  • - Bereitstellen keiner Entfernungsinformation
  wobei um die erste Entfernung (E1) ein erster Toleranzbereich definiert wird und um die zweite Entfernung (E2) ein zweiter Toleranzbereich definiert wird, und wobei die Entfernungsinformation nur dann bereitgestellt wird, wenn sich der erste Toleranzbereich und der zweite Toleranzbereich überlappen.

The invention relates to a method for providing distance information to a vehicle-to-X subscriber, the method having the following steps:

• - receiving a vehicle-to-X message which contains location information about an external vehicle-to-X participant,
• - Carrying out a distance measurement to determine a first distance to the external vehicle-to-X participant,
• - Calculating a second distance between the vehicle-to-X subscriber and the external vehicle-to-X subscriber based on the location information about the external vehicle-to-X subscriber,
• - Comparing the first distance with the second distance, and depending on it
  • - Providing the first distance and/or the second distance as distance information,
  • - Providing a value calculated from the first distance and/or the second distance as distance information, or
  • - Not providing any distance information
  wherein a first tolerance range is defined around the first distance (E1) and a second tolerance range is defined around the second distance (E2), and wherein the distance information is only provided if the first tolerance range and the second tolerance range overlap.

Using this method, a distance determination based purely on location information, which is obtained through vehicle-to-X communication or a direct location determination of the ego vehicle, can be supplemented by a distance measurement, which can be used for verification and/or correction.

Distance information is in particular information about a distance between two objects, in particular between two vehicle-to-X participants, for example two vehicles. Location information can be specified, for example, in a coordinate system, which can in particular indicate a location on the earth's surface. Accordingly, it can be a two-dimensional, but also a three-dimensional coordinate system. A unique coordinate in such a coordinate system therefore fundamentally clearly indicates a location. However, corresponding location information is typically subject to errors, so that location information can also be understood to mean that an object is not located at a specific point, but within a specific area, which can result, for example, from a coordinate of the location information and an associated error . Comparing the first distance with the second distance can in particular mean that an absolute or relative deviation between the two distances is determined. It can, for example depend on whether such a deviation is at least as high as a threshold value or is below, which type of provision of distance information or provision of no distance information is chosen. Based on this, it can also be determined whether the first distance or the second distance is provided as distance information.

The provision can in particular be carried out in such a way that the distance information is provided to another function or unit. This can use the distance information, for example, as part of a security function.

The distance measurement can be carried out in particular in response to receiving the vehicle-to-X message. A distance measurement can therefore advantageously be carried out when a vehicle-to-X message is available, by means of which the method described can be carried out. However, it can also be provided that the distance measurement is not carried out for all received vehicle-to-X messages, but, for example, only for vehicle-to-X messages of a certain type, from a certain transmitter or from several specific transmitters certain times and/or after receiving a certain number of vehicle-to-X messages.

The distance measurement can be carried out in particular by means of a transit time measurement. A transit time measurement can in particular be carried out in such a way that the transit time of a signal is determined, this transit time being dependent on a distance traveled. Using the known speed of light, the distance can then be determined. This enables very precise distance measurement.

The transit time measurement can be carried out in particular by means of the vehicle-to-X message and/or by means of one or more further vehicle-to-X messages. In particular, pulses that are as broadband as possible can be sent out and measured in terms of transit time. The actual message can be sent out separately. For example, when a message is received, a distance measurement request is sent to the sender. This means that time proximity can be guaranteed. However, other approaches can also be used.

The second distance can be calculated in particular based on location information about the vehicle-to-X participant. Such location information can be determined, for example, using satellite navigation, inertial sensors and/or triangulation. The distance between the two vehicle-to-X participants can be calculated using location information of the external vehicle-to-X participant contained in a vehicle-to-X message and the location information of the vehicle-to-X participant For example, a route length between the locations that indicate the two location information is determined. This allows for easy calculation.

In particular, a first tolerance range can be defined around the first distance and/or a second tolerance range can be defined around the second distance. In particular, it can be provided that the distance information is only provided if the first tolerance range and the second tolerance range overlap. The tolerance ranges can in particular define areas on the earth's surface. In particular, you can display where a respective vehicle-to-X participant is located, including a measurement-related error range. If the two tolerance ranges do not overlap, this indicates that there is a substantial error in at least one measurement, since it is not physically possible for an object to be in two locations at the same time. The procedure described can prevent unreliable data from being further processed. In particular, it can be provided that no distance information is provided if the first distance and the second distance differ relatively or absolutely by at least a predetermined threshold value. This can also prevent potentially unreliable data from being passed on. If the first distance and the second distance differ relatively or absolutely by at least such a predetermined threshold value, it can be assumed that the distance measurement or the determination of locations is not reliable, i.e. that there is a substantial error.

According to a further development, an angular position of the other vehicle-to-X participant is also determined during the distance measurement. This makes it possible to specify at what angle, for example relative to a predetermined reference such as a direction of travel or a vehicle longitudinal axis, the other vehicle-to-X participant is located. The one-dimensional distance information can thus be expanded to two-dimensional information.

Based on the first distance and the angular position, further location information can be calculated. A first tolerance area can be defined around the further location information and a second tolerance area can be defined around the location information be defined. The distance information is preferably only provided if the first tolerance area and the second tolerance area overlap. This allows a further check to be introduced, whereby the angular position can also be taken into account. If the tolerance areas do not overlap, a substantial error can be assumed, and by not providing the distance information, unreliable data can be prevented from being further processed.

In particular, further location information can be calculated based on the first distance and the angular position. Preferably, no distance information is provided if the further location information and the location information differ relatively or absolutely by at least a predetermined threshold value. This can also introduce additional verification, which can prevent unreliable data from being further processed.

An angular position can be achieved, for example, using a suitable antenna array. For example, angle-dependent signal strengths, phase positions or transit times can be determined in order to calculate the angular position.

When comparing the first distance with the second distance, a confidence dependent thereon can in particular be determined. The distance information can in particular be provided together with the confidence. This allows the distance information to be expanded to include an additional component, namely confidence. This tells a downstream function how reliable the distance information is. Typically, high confidence indicates that the distance information was determined based on a first distance and a second distance that differed only slightly, and vice versa.

In particular, one or more tolerance ranges, tolerance areas or threshold values can be adjusted depending on the comparison. This makes it possible to react dynamically to the comparison between the two distances, whereby the already mentioned tolerance ranges, tolerance areas or threshold values can be set so that they reflect an uncertainty which is indicated by the comparison of the two distances. In particular, tolerance ranges and/or tolerance areas can be larger, the larger a relative or absolute distance is between the first distance and the second distance.

In particular, the vehicle-to-X participant can be a motor vehicle or an infrastructure facility. The vehicle-to-X participant can thereby advantageously determine a secure distance to another vehicle-to-X participant. Likewise, the external vehicle-to-X participant can in particular be a motor vehicle or an infrastructure facility.

In general, it should be mentioned that in vehicle-to-X communication, for example, ego positions of the senders are sent in specific data containers. These are typically based on self-positioning, for example on satellite navigation and/or inertial sensors.

An absolute position is particularly important for automated vehicles, but a relative classification of the surrounding road users is also particularly important. A distance measurement can help to improve the information from the ego information containers for one's own purposes, especially through the relative view. In one case, the position and the confidence of the sender's position are read out in the message and compared with the receiver position. Ranging information is then used and the contents of the message can be changed accordingly before they are further processed in an object fusion or in another application. This can be particularly relevant for the ego container of a Cooperative Perception Message (CPM), since the position of the sent objects can be derived from this position of the sender.

A distance measurement can match the difference in transmitter and receiver positions within the accuracy of that measurement. This can be particularly the case if the confidence of the CPM and the confidence of the ranking overlap. This can improve the confidence in the message. This can make it easier for object fusion to track individual objects separately as such. A higher confidence level is also created for sensor-based objects because an uncertainty factor can be reduced. Positioning of the transmitter vehicle can thus be improved.

In another case, within the uncertainty of the distance measurement, it does not match the position including the confidence of the transmitter. This can have several causes. For example, the transmitter may have an incorrect position. Likewise, the receiver may have an incorrect position. The distance measurement can also be incorrect. In this case you have different options. For example, the confidence in the message can be degraded so that both the relative position as well as the distance measurement lead to an overlap. If the positioning with the ranging of different transmitters generally leads to a correct result, a sensible reaction to the identified problem can be made. The receiver confidence can also be worsened, especially if this result occurs equally for several senders.

In particular, a procedure is described here in which the received data can be conditioned with additional information and the sender's self-assessment can thus be corrected. This makes standard object fusion possible, whereby the same software can be used with or without an additional distance measurement. Modification of the vehicle-to-X messages is also not necessary.

• 1: eine Anordnung mit zwei Kraftfahrzeugen, und
• 2: mögliche Reaktionen auf bestimmte Zustände.

A person skilled in the art will find further features and advantages in the exemplary embodiment described below with reference to the accompanying drawing. Show:

• 1 : an arrangement with two motor vehicles, and
• 2 : possible reactions to certain conditions.

1 shows an arrangement with a first motor vehicle 10 and a second motor vehicle 20. The two motor vehicles 10, 20 represent respective vehicle-to-X participants 10, 20. Each of the motor vehicles 10, 20 is connected to a respective vehicle-to-X Communication module 12, 22 provided, with which it can participate in the radio traffic of vehicle-to-X communication.

In particular, vehicle-to-X messages can be exchanged between the two motor vehicles 10, 20. For example, the first motor vehicle 10 may send a vehicle-to-X message to the second motor vehicle 20. This vehicle-to-X message may contain location information indicating a location that the first motor vehicle 10 has determined. This can be based, for example, on satellite navigation, inertial sensors or terrestrial navigation. The second motor vehicle 20 also knows its own position, which also represents location information. By comparing the two location information, the second motor vehicle 20 can determine a distance based on the received vehicle-to-X message, which is hereinafter referred to as the second distance.

In addition, a first distance can be determined via the transit time of messages between the two motor vehicles 10, 20. Such a procedure is referred to in particular as distance measurement. It is independent of the location information of the motor vehicles or the location information contained in vehicle-to-X messages. For example, a vehicle-to-X message may be sent from the second motor vehicle 20 to the first motor vehicle 10, which in turn may send it back. If processing times are known, the distance between the two motor vehicles 10, 20 can be calculated from the remaining signal transit time. The first distance and the second distance can then be compared with each other. If these differ from each other by less than a predetermined threshold value, the first distance and/or the second distance can be provided as distance information. A calculated value from the two distances, for example an average, in particular an arithmetic average, can also be provided as distance information. If the two distances deviate too far from each other, the provision of distance information can be dispensed with, since there is obviously a serious error in at least one distance determination, which would prevent further use of the distance information.

In addition, angle information can also be determined. An example of such an angle is in 2 shown, starting from a central object. The angle information indicates the angle at which another vehicle-to-X participant is located relative to a reference point such as a longitudinal axis, this angle information being based on a measurement and not on an evaluation of location information.

In 2 Several distances are shown, namely three first distances E1 and a second distance E2. The second distance E2 is basically a distance which is determined based on location information. The first distance E1, in contrast, is one that is calculated based on transit time measurements and, if necessary, additional angle measurements. In addition to the respective distances E1, E2, respective confidence intervals are given. For the second distance E2, this is a ring within which another vehicle-to-X participant is expected based on the calculated distance. The ring indicates that the calculation method is not 100% accurate. This allows measurement errors to be taken into account. At the first distances E1, the confidence is indicated by a circle around the respective tip of the arrow. In this area, based on the calculation method of the first distance E1 assumes the other vehicle-to-X participant.

A total of three cases are shown. In case 1, the circle overlaps with the ring, so that even more precise positioning of the external vehicle-to-X participant is possible, namely in the hatched area. In case 2, the circle also overlaps the ring, although in this case the circle is a little further out and does not intersect the inner edge of the ring. This allows even better limitation of the external vehicle-to-X participant.

In case 3, the inner, thinner circle does not initially overlap with the ring. Accordingly, according to one possible embodiment, there is no need to provide distance information. Alternatively, it is also possible to expand the confidence interval so that it overlaps with the ring. This is indicated by the slightly outer, thicker circle. In this case too, a hatched area is created as an overlap with the ring of the second distance E2. This distance information can then be used with a correspondingly greater uncertainty.

In general, it should be noted that vehicle-to-X communication is understood to mean, in particular, direct communication between vehicles and/or between vehicles and infrastructure facilities. 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 the mediation of a mobile phone network or a similar external infrastructure and which therefore depends on other solutions , which are based, for example, on a mobile phone network. For example, vehicle-to-X communication can occur using the IEEE 802.11p, IEEE 802.11 bd 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 C2I (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 specified. However, they can also be executed in a different order if this makes technical sense. The method according to the invention can be carried out in one of its embodiments, for example with a specific combination of steps, in such a way that no further steps are carried out. However, in principle, further steps can also be carried out, including those not mentioned.

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

References in subclaims can indicate preferred combinations of the respective features, but do not exclude other combinations of features.

List of reference symbols:

E1

first distance

E2

second distance

10

motor vehicle

12

Vehicle-to-X communication module

20

motor vehicle

22

Vehicle-to-X communication module

Claims (14)

Method for providing distance information to a vehicle-to-X subscriber (10, 20), the method having the following steps: - receiving a vehicle-to-X message which contains location information about an external vehicle-to-X Participants (10, 20) include - carrying out a distance measurement to determine a first distance (E1) to the external vehicle-to-X participant (10, 20), - calculating a second distance (E2) between the vehicle-to-X participant (10, 20), X-subscriber (10, 20) and the external vehicle-to-X-subscriber (10, 20) based on the location information about the external vehicle-to-X-subscriber (10, 20), - comparing the first distance (E1 ) with the second distance (E2), and depending on this - providing the first distance (E1) and / or the second distance (E2) as distance information, - providing one of the first distance (E1) and / or the second distance (E2 ) calculated value as distance information, or - providing no distance information; wherein a first tolerance range is defined around the first distance (E1) and a second tolerance range is defined around the second distance (E2), and wherein the distance information is only provided if the first tolerance range and the second tolerance range overlap. Procedure according to Claim 1 , - where the distance measurement is performed in response to receiving the vehicle-to-X message. Method according to one of the preceding claims, - The distance measurement is carried out using a transit time measurement. Procedure according to Claim 3 , - whereby the transit time measurement is carried out using the vehicle-to-X message and/or using one or more further vehicle-to-X messages. Method according to one of the preceding claims, - wherein the second distance (E2) is also calculated based on location information about the vehicle-to-X participant (10, 20). Procedure according to Claim 5 , - whereby the location information is determined using satellite navigation, inertial sensors and/or triangulation. Method according to one of the preceding claims, - No distance information is provided if the first distance (E1) and the second distance (E2) differ relatively or absolutely by at least a predetermined threshold value. Method according to one of the preceding claims, - An angular position of the further vehicle-to-X participant (10, 20) is also determined during the distance measurement. Procedure according to Claim 8 , - wherein further location information is calculated based on the first distance (E1) and the angular position, - a first tolerance area is defined around the further location information and a second tolerance area is defined around the location information, - the distance information is only provided, if the first tolerance area and the second tolerance area overlap. Procedure according to one of the Claims 8 or 9 , - wherein further location information is calculated based on the first distance (E1) and the angular position, - no distance information is provided if the further location information and the location information differ relatively or absolutely by at least a predetermined threshold value. Method according to one of the preceding claims, - whereby when comparing the first distance (E1) with the second distance (E2), a confidence dependent on it is determined, and - where the distance information is provided together with the confidence. Method according to one of the preceding claims, - whereby one or more tolerance ranges, tolerance areas or threshold values are adjusted depending on the comparison. Method according to one of the preceding claims, - Wherein the vehicle-to-X participant (10, 20) is a motor vehicle or an infrastructure facility. Method according to one of the preceding claims, - Wherein the external vehicle-to-X participant (10, 20) is a motor vehicle or an infrastructure facility.

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