JP2024052175A - Message control device, message control method, and vehicle - Google Patents

Abstract

[Problem] To suitably suppress errors in estimating a target's position. [Solution] A message control device according to one aspect of the present disclosure has a control unit 11 that generates a message including a target's position detected by a sensor and a message indicating the reliability of information related to the sensor's orientation, and a communication unit 15 that transmits the message. When the reliability of information related to the sensor's orientation included in the message is low, a device that receives the message can avoid using the target's position included in the message for estimating the target's position. This makes it possible to suppress errors in estimating the target's position. [Selected Figure] Figure 5

Description

This disclosure relates to a message control device, a message control method, and a vehicle in an Intelligent Transport System (ITS).

For autonomous driving and safe driving support, wireless sharing of information acquired by vehicles with other vehicles is being considered. For example, there is a technology called Collective Perception Service (CPS) that shares the detection status of targets and free space based on sensors (Non-Patent Document 1). In CPS, the direction of the sensor installed in the sending vehicle and the relative positional relationship between the sending vehicle and the target detected by the sensor are transmitted via communication, and the receiving vehicle can use the relative position of the target calculated from this information to avoid collisions.

ETSI TR 103 562 V2.1.1 (2019-12) “Intelligent Transport Systems (ITS); Vehicular Communications; Basic Set of Applications; Analysis of the Collective Perception Service (CPS); Release 2”, December 18, 2019

The message used in the CPS described above is called a Collective Perception Message (CPM). The CPM includes the reference sensor starting position, the x distance from the sensor starting position to the target, and the y distance. The x distance is the distance in the x-axis direction parallel to the vehicle's longitudinal direction, and the y distance is the distance in the y-axis direction parallel to the vehicle's lateral direction. The x distance and y distance are detected by sensors.

Even if the target does not move, if the direction in which the vehicle is facing changes, the x and y distances will change. As can be seen from the above, information on the direction in which the vehicle is facing (hereinafter simply referred to as the vehicle orientation) is important when determining the absolute position of the target. If there is an error in the vehicle orientation, the absolute position of the target cannot be calculated correctly.

By the way, V2X systems generally use the Global Navigation Satellite System (GNSS) to obtain the vehicle's direction of travel, so the direction in which the vehicle is moving, rather than the direction the vehicle is facing, is used as information on the vehicle's direction of travel.

There may be a difference between the direction the vehicle is moving and the direction the vehicle is facing. When this difference occurs, if the direction the vehicle is moving is used as a substitute for the direction the vehicle is facing to determine the position of the detected target, an error will occur in the target position. This may result in an error in estimating the target's position in a receiving vehicle that receives a CPM containing information indicating that position.

Therefore, one of the objectives of the present disclosure is to provide a message control device, a message control method, and a vehicle that can effectively suppress errors in estimating the position of a target object.

A message control device according to one aspect of the present disclosure has a control unit that generates a message including the position of a target detected by a sensor and a message indicating the reliability of information related to the orientation of the sensor, and a communication unit that transmits the message.

Another message control device according to one aspect of the present disclosure has a control unit that generates a message including the position of a target detected by a sensor, and a communication unit that transmits the message, and the control unit determines whether or not to transmit a message from the communication unit based on the reliability of information related to the orientation of the sensor or information for calculating the reliability.

Another message control device according to one aspect of the present disclosure has a communication unit that receives a message including a target position and the reliability or information for calculating the reliability of the information regarding the sensor orientation, and a control unit that determines the relative position of the target based on the received message, and the control unit determines whether or not to use the target position included in the message for estimating the target position based on the reliability that can be determined from the reliability or the information for calculating the reliability.

A message control method according to one aspect of the present disclosure generates a message including the position of a target detected by a sensor and a message indicating the reliability of information regarding the orientation of the sensor, and transmits the message.

A vehicle according to one aspect of the present disclosure has the above-mentioned message control device.

According to one aspect of the present disclosure, errors in estimating the position of a target can be effectively suppressed.

FIG. 1 is a diagram illustrating an example of a schematic configuration of an intelligent road transport system according to an embodiment. FIG. 2 is a diagram showing an example of the distance to a target. FIG. 3A is a diagram showing an example of an error in the position of a detected target based on an error in the orientation of a vehicle. FIG. 3B is a diagram showing an example of an error in the position of a detected target based on an error in the orientation of a vehicle. FIG. 3C is a diagram showing an example of an error in the position of a detected target based on an error in the orientation of a vehicle. FIG. 4A is a diagram illustrating an example of the difference between the direction a vehicle is traveling and the direction the vehicle is facing. FIG. 4B is a diagram illustrating an example of the difference between the direction a vehicle is traveling and the direction the vehicle is facing. FIG. 5 is a diagram illustrating an example of a vehicle 10 according to an embodiment.

The following describes in detail an embodiment of the present disclosure with reference to the accompanying drawings. In the following description, identical parts are given the same reference numerals. Since identical parts have the same names, functions, etc., detailed descriptions will not be repeated.

(Intelligent Transport Systems)
Fig. 1 is a diagram showing an example of a schematic configuration of an intelligent transport system according to an embodiment. The intelligent transport system 1 shown in Fig. 1 may include a vehicle 10, a roadside unit 20, and an ITS server 30. The intelligent transport system 1 may be interchangeably read as an Intelligent Transport System (hereinafter, ITS), a road transport system, a transport system, and the like. The roadside unit 20 may be called a RoadSide Unit (hereinafter, RSU) 20.

ITS1 may be called a system in which information (e.g., traffic information, information for autonomous driving, etc.) is shared among multiple vehicles (so-called Cooperative ITS (CITS)).

In ITS1, communication is carried out using any one or a combination of the message control methods according to the embodiments of this disclosure described below.

Vehicle 10 is a vehicle that travels on a roadway. Vehicle 10 may be a car, or a vehicle that does not move autonomously (e.g., a bicycle). A car may be one or both of a four-wheeled vehicle and a two-wheeled vehicle.

The vehicle 10 has an on-board communication device and can communicate with other vehicles 10, the RSU 20, the ITS server 30, etc., via wireless communication. Examples of wireless communication methods include Long Term Evolution (LTE), 5th generation mobile communication system (5G), and Wi-Fi (registered trademark).

Direct communication between vehicles 10 may be referred to as vehicle-to-vehicle (V2V) communication. Communication between vehicles 10 and RSUs 20 may be referred to as vehicle-to-infrastructure (V2I) communication. V2V and V2I communication may be referred to as vehicle-to-everything (V2X) communication.

The messages transmitted between the vehicles 10 may include, for example, at least one of the following:
Cooperative Awareness Message (CAM), which periodically transmits vehicle position, speed, etc.
Decentralized Environmental Notification Message (DENM), which notifies when certain events occur;
- Collective Perception Message (CPM) for sharing the environment perceived based on perception sensors.

CAM is a message sent in the Cooperative Awareness (CA) service proposed by ETSI (European Telecommunications Standards Institute). Cooperative awareness in road traffic means that road users and roadside infrastructure can know each other's location, movement and attributes. Road users refer to all users on and around the road who are responsible for road safety and control, such as cars, trucks, motorbikes, bicycles, pedestrians, etc., and roadside infrastructure refers to facilities such as road signs, traffic lights, barriers, entrances, etc.

CPM is a message sent in the CP service proposed by ETSI. The CP service is a service that notifies the surrounding area of the positions, behavior, and attributes of surrounding road users and other targets detected by the vehicle sending the CPM.

The RSU 20 collects information on surrounding road conditions and surrounding traffic lights. Traffic light information can include the color of the traffic lights. The RSU 20 also has a function of communicating the collected information with the vehicle 10, other RSUs 20, the ITS server 30, and the like. Traffic lights may be called traffic lights. Traffic light information may be called information indicating the traffic light status. The RSU 20 may be equipped with a sensor and collect information using the sensor. This sensor may include a camera. Examples of road conditions are the road congestion status, the presence or absence of fallen objects, and the condition of the road surface. The RSU 20 may relay communication between the vehicle 10 and the ITS server 30.

The RSU 20 may be connected to one or both of the traffic lights and sensors so that they can communicate with each other via wires or wirelessly.

A mobile communication terminal may be used as the communication unit of the RSU 20. The mobile communication terminal is, for example, a mobile terminal such as a mobile phone, a smartphone, or a tablet terminal. The communication terminal is equipped with one or more sensors such as a camera, and is therefore expected to contribute to providing useful information.

The ITS server 30 may provide traffic information, driving assistance information, etc. to the vehicle 10, or control the color of traffic lights based on information received from the vehicle 10, the RSU 20, etc. The ITS server 30 may be a cloud server or an on-premise server.

An example of the functional configuration and hardware configuration of each device, such as the vehicle 10, will be described later.

Note that the system configuration of ITS 1 shown in FIG. 1 is an example, and the configuration of ITS system 1 is not limited to the configuration shown in FIG. 1. Furthermore, the number of RSUs 20 and ITS servers 30 is not limited to the number shown in FIG. 1.

In the following description of this disclosure, reference numbers may be omitted. For example, ITS1 may simply be written as ITS, and vehicle 10 may simply be written as vehicle.

(Collective Perception Message (CPM))
The message used in the above-mentioned CPS is called a CPM. The CPM includes a sensor start position, an x distance from the sensor start position to a target, a y distance, and the like. A receiving vehicle that receives the CPM can calculate the absolute position of the target from the sensor start position, and the x distance and y distance from the sensor start position to the target. In this disclosure, the target may be read as a perceived object or the like.

Here, the sensor starting position may be calculated from the absolute position of the vehicle, the mounting position of the sensor in the vehicle, the direction in which the vehicle is facing, etc. The absolute position of the vehicle may be, for example, latitude and longitude obtained by a positioning system (e.g., a satellite positioning system (Global Navigation Satellite System (GNSS), Global Positioning System (GPS), etc.)), and may be called a GPS positioning position, etc.

The sensor mounting position may also be a position with an offset (e.g., offset in the x-axis/y-axis direction) added based on a reference point for the vehicle. The reference point for the vehicle may be a ground position at the center of the front side of a rectangle (bounding box) surrounding the vehicle, or a GPS positioning position within the vehicle (e.g., the location where the locator is located).

The direction of the sensor axis may also be calculated from the direction in which the vehicle is facing. Alternatively, the start and end opening angles of the sensor detection range may be used instead of the direction of the sensor axis. Because the sensor is fixed to the vehicle, the direction of the sensor axis relative to the direction in which the vehicle is facing or the start and end opening angles of the sensor detection range are fixed values. Therefore, the direction of the sensor axis or the start and end opening angles of the sensor detection range can be calculated by adding or subtracting a fixed value to the direction in which the vehicle is facing. Note that the direction in which the vehicle is traveling is used as the direction in which the vehicle is facing.

The distance to the target may be the distance from the sensor starting position to the target, or may be calculated from the sensor detection results.

The sensor starting position, sensor mounting position, sensor axis direction, etc. may differ for each sensor, and the CPM may include information regarding these for each of multiple sensors.

Figure 2 shows an example of the distance to a target. In the vehicle coordinate system, the x-axis extends in the longitudinal direction of the vehicle, the y-axis extends left and right when viewed from the front of the vehicle, and the z-axis is perpendicular to the x-axis and y-axis.

In this example, target A is located at a distance of 1 in the x-axis direction and 1 in the y-axis direction from the vehicle's sensor starting point position, and target B is located at a distance of 2 in the x-axis direction and 2 in the y-axis direction from the vehicle's sensor starting point position.

In this disclosure, the target position is assumed to represent the position with the shortest distance from the sensor origin position, but is not limited to this.

A vehicle that receives a CPM from another vehicle may determine the absolute position of the target based on at least one of its own absolute position, the position of the other vehicle (obtained via CAM, etc.), the distance from the other vehicle to the target (obtained via CPM), etc.

As can be seen from the above, when determining the absolute position of a target, information on the direction in which the vehicle is facing (hereinafter also simply referred to as the vehicle orientation) is important. The vehicle orientation is the direction toward the front of the vehicle on the vehicle longitudinal line, which is, for example, the vehicle width center line. If there is an error in the vehicle orientation, the absolute position of the target cannot be calculated correctly. Note that in this disclosure, "orientation" may also mean azimuth, azimuth angle, etc.

Figures 3A-3C are diagrams showing an example of an error in the position of a detected target due to an error in the vehicle's orientation. Figure 3A shows an example in which the vehicle's orientation was accurately recognized (there was no error in the vehicle's orientation from reality), the sensor mounting point and sensor origin position were correctly calculated from the GPS position, and the direction of the sensor axis was correctly calculated.

Figure 3B shows a case where the vehicle orientation could not be accurately recognized, i.e., there was an error in the vehicle orientation from reality. Even if the GPS positioning position is the same as in Figure 3A, if the vehicle orientation is incorrect, the sensor origin position will be a different position from the sensor origin position shown in Figure 3A.

Figure 3C shows the position of the target detected in the case of Figure 3A (dashed line) and the position of the target detected in the case of Figure 3B (solid line). The positions of targets A and B relative to the vehicle are the same as in Figure 2. It can be seen that if the vehicle is facing in the wrong direction, an error occurs in the detected target position, and the further away from the sensor, i.e., the further away from the vehicle, the larger the error.

As already explained, the direction of travel in a V2X system is the "direction in which the vehicle is moving" (also called "heading"), not the "direction in which the vehicle is facing."

Figures 4A and 4B show an example of the difference between the direction a vehicle is traveling and the direction the vehicle is facing.

As shown in Figure 4A, when the vehicle is moving straight, the two are almost the same. On the other hand, as shown in Figure 4B, when the vehicle is turning a corner, the orientation of the vehicle and the orientation of the tires differ, so a difference occurs between the orientation of the vehicle and the direction in which the vehicle is moving. Note that, since the vehicle is affected by centrifugal force, etc., the orientation of the tires, or the rotation angle of the steering wheel, whose rotation angle changes depending on the orientation of the tires, do not necessarily indicate the orientation of the vehicle.

In the present disclosure, the rotation angle of the steering wheel and the direction/angle of the tires may be interpreted as interchangeable. The steering wheel may be referred to as a handle. The rotation angle of the steering wheel may be interpreted as a steering angle, a steering angle, a rotation angle of the handle, or a direction of the steering wheel. The direction of the tires may refer to the direction in which the tires roll. The angle of the tires may refer to the angle of the direction of the tires when the direction of the vehicle is taken as the reference (e.g., 0°).

One method for determining the "direction in which a vehicle is moving" is to use a positioning system. However, it is known to be difficult to accurately determine the "direction in which a vehicle is moving" when the vehicle is moving at a low speed.

For example, in the Basic System Profile (BSP) of the CAR 2 CAR Communication Consortium (C2CCC) and J2945 of the Society of Automotive Engineers (SAE), it is being considered that when the vehicle speed falls below a certain level (e.g., below 0.08 m/s), the direction in which the vehicle is moving is latched (fixed) to the last value before that. Therefore, in these standards under consideration, when the vehicle is moving at a low speed (e.g., when the vehicle is moving slowly while waiting to turn right/left), the direction in which the vehicle is moving as determined by a positioning system or the like may differ from the actual direction of travel of the vehicle.

If this inaccurate "direction in which the vehicle is moving" is used as the vehicle's orientation, an error will occur in the detected target position, as described in Figures 3A-3C. This may result in an error in estimating the target's position in the receiving vehicle that receives the CPM containing that position information.

The inventors therefore came up with a method for suppressing errors in estimating the position of a target in a message-receiving vehicle in a situation where there is a difference between the orientation of the message-sending vehicle and the direction in which the vehicle is traveling. According to one aspect of the present disclosure, in such a situation, it is possible to preferably suppress the use of a target position that may be inappropriate by lowering the reliability of the detected position of the target or by not sending a message.

In the following description of the embodiment, the message transmitted by the vehicle is assumed to be a CPM, but is not limited to this. In other words, the CPM in this disclosure may be interpreted as any message that includes information on at least one of the sensor position, the target position, etc. The message may be a message defined in CPM, CAM, DENM, SAE, Basic Safety Message (BSM), C2CCC BSP, or other standards.

(Message Control Method)
A message control method according to an embodiment of the present disclosure is described below. Each message control method may be applied to the above-mentioned ITS.

First Embodiment
The first embodiment relates to control of the transmit side of CPM.

In the first embodiment, the vehicle may calculate the confidence level (which may be called the confidence value, etc.) of the CPM and transmit the confidence level together with the CPM. In addition to the confidence level, the CPM may also include the position of the target detected by the sensor.

Here, the reliability of the CPM in the first embodiment may correspond to the reliability of all information included in the CPM, or may correspond to the reliability of some of the information included in the CPM. The information included in the CPM may be a container, a parameter (which may be called a data frame, a data element, etc.), etc. The reliability of the CPM may be a value that indicates that the lower the reliability, the lower the reliability of all or some of the information.

The confidence level for the CPM may relate only to one or more of the containers, such as the sensor information container and the perceived object container in Non-Patent Document 1.

The reliability of the CPM may be the reliability of information on the sensor orientation that is the basis for calculating the target position transmitted in the CPM. The information on the sensor orientation may be included in the vehicle sensor information included in the sensor information container described above. For example, the information on the sensor orientation may include the opening angle start (OpeningAngleStart)/opening angle end (OpeningAngleEnd) for the horizontal/vertical directions.

The reliability of the information about the sensor orientation may be included in the sensor information container described above together with the information about the sensor orientation. Also, the reliability of the information about the sensor orientation may be included in the vehicle sensor information.

The reliability of the information about the sensor orientation is not limited to the reliability of information that directly indicates the sensor orientation, such as the opening angle start and opening angle end described above. The reliability of the information about the sensor orientation may be the reliability of the target position detected by the sensor. This is because the value of the target position detected by the sensor also changes in relation to the sensor orientation. In this case, the target position detected by the sensor is information about the sensor orientation.

The reliability of the information about the sensor orientation may also be the reliability of free space, which is a space in which no target is detected by the sensor. This is because the target position, i.e., the position where a target exists, and the free space, i.e., the position where no target exists, are in a complementary relationship. In this case, the information specifying the range of the free space is information about the sensor orientation.

In the present disclosure, the confidence regarding CPM may correspond to a value used as the confidence of a sensor, target, etc. in V2V/V2X communication, may correspond to a new value for scaling that value, or may correspond to a value for a confidence different from those. For example, the confidence regarding CPM may include the heading confidence (headingConfidence), free space confidence (freeSpaceConfidence), distance confidence (DistanceConfidence), angle confidence (AngleConfidence), speed confidence (SpeedConfidence), or any other confidence in Non-Patent Document 1.

In this disclosure, confidence in a CPM may refer to the precision (e.g., absolute precision) of a measurement with a confidence of X% (where X is a real number, e.g., X=95).

In this disclosure, the confidence level for a CPM may be expressed as a real number between 0 and 1 (e.g., 1 being high confidence) or may be expressed as several levels (e.g., high, medium, low).

The reliability of the CPM may be calculated based on any one of the following embodiments 1.1-1.4 or a combination thereof.

[Embodiment 1.1]
In embodiment 1.1, the vehicle may change the reliability of the CPM based on the speed of the vehicle. The reliability to be changed may be, in particular, the reliability of the information included in the CPM, regarding the sensor orientation.

The vehicle may be controlled so that the lower the vehicle speed is, the lower the reliability is, regardless of the speed range. However, it is preferable to lower the reliability when the vehicle speed is below a threshold value compared to when the speed is equal to or above the threshold value. This is because the reliability of the "direction in which the vehicle is traveling," which is used as the vehicle orientation, becomes lower when the vehicle speed is below the threshold value.

The threshold value can be, for example, a walking speed. The threshold value may also be set even lower, to a speed calculated based on the swaying (i.e., acceleration) that occurs in the vehicle when it stops after slowing down. The threshold value for a walking speed is, for example, 1.4 m/s. The threshold value for a speed calculated based on the swaying that occurs in the vehicle when it stops after slowing down is, for example, 0.08 m/s. Note that "less than the threshold" may be read as "below the threshold."

When the speed of the vehicle is less than the threshold, the relationship between the reliability and the speed may be a constant value regardless of the speed. Also, when the speed of the vehicle is less than the threshold, the relationship between the reliability and the speed may be a relationship in which the reliability decreases linearly, curved, or in stages as the speed decreases. When the relationship between the reliability and the speed is a curve, for example, the relationship between the speed and the reliability may be a downward convex quadratic function. Also, the reliability may be calculated using a calculation formula set in advance. For example, the vehicle may calculate the reliability when the speed of the vehicle is low by subtracting or multiplying a value according to the speed based on the reliability when the speed of the vehicle is high and all other conditions are assumed to be the same.

[Embodiment 1.2]
In embodiment 1.2, the vehicle may change the reliability of the CPM based on whether the vehicle is moving straight or not. As in embodiment 1.1, the reliability to be changed may be the reliability of the information on the sensor orientation among the information included in the CPM. As described with reference to FIG. 4A and FIG. 4B, when the vehicle is turning a curve, a difference occurs between the orientation of the vehicle and the direction in which the vehicle is moving. Therefore, when the vehicle is turning a curve, the reliability of the information on the sensor orientation that changes depending on the orientation of the vehicle decreases compared to when the vehicle is moving straight.

The vehicle may control the reliability so as to be lowered when the vehicle is not moving straight. For example, the vehicle may calculate the reliability when the vehicle is not moving straight by subtracting or multiplying a predetermined value based on the reliability when the vehicle is moving straight and other conditions are assumed to be the same.

In this disclosure, "going straight" may include going almost straight, and may mean, for example, that the angle between the direction in which the vehicle is moving and the direction in which the vehicle is facing is equal to or less than a certain threshold (e.g., 3°), or that the steering angle (or tire angle) is equal to or less than a certain threshold (e.g., 3°). In addition, whether or not the vehicle is going straight may be determined based on the time that the straight-line state continues. Whether or not the vehicle is going straight may be determined based on the linearity of the history of the vehicle position (i.e., the driving trajectory) detected sequentially by a positioning system or the like. The direction in which the vehicle is going may be determined based on the history of the vehicle position detected sequentially by a positioning system or the like. The direction in which the vehicle is going may also be determined from the direction of the velocity vector obtained by the positioning system.

The threshold value may be predetermined in the standard, or information regarding the threshold value may be notified to the vehicle from another vehicle, an RSU, or an ITS server.

Furthermore, instead of changing the reliability depending on whether "the vehicle is moving straight" or "the vehicle is not moving straight", the reliability may be changed according to the degree to which the direction in which the vehicle is moving is curved. In this case, the reliability may be lowered the more curved the direction in which the vehicle is moving, in other words, the more the vehicle turns. The relationship between the degree to which the direction in which the vehicle is moving is curved and the reliability may be such that the reliability decreases linearly, curved, or in stages as the degree to which the direction in which the vehicle is moving is curved increases. The reliability may be changed according to the degree to which the direction in which the vehicle is moving is curved only when the vehicle is not moving straight.

[Embodiment 1.3]
In embodiment 1.3, the vehicle may change the reliability of the CPM based on the time that the steering angle of the vehicle was continuously facing forward. The reliability to be changed may be, in particular, the reliability of the information on the sensor orientation among the information included in the CPM. This is because "going straight" can be determined by the steering angle, as described in embodiment 1.2. Embodiment 1.3 embodies some of the forms shown in embodiment 1.2.

The vehicle may change the reliability of the CPM based on the duration that the steering angle has been maintained within a certain range (e.g., ±3°) of the steering angle when the vehicle is traveling straight (e.g., 0°). If the steering angle changes beyond that range, the duration may be reset to 0. The duration is set to a length of time that allows the vehicle to be determined to be traveling straight. An example duration is on the order of a few seconds.

The angle value within the certain range may be predetermined in a standard, or information regarding the threshold value may be notified to the vehicle from another vehicle, an RSU, or an ITS server.

The vehicle may control the reliability so that the shorter the duration is, the lower the reliability becomes. For example, the vehicle may calculate the reliability when the duration is short by subtracting or multiplying a predetermined value based on the reliability when the duration is long and other conditions are assumed to be the same.

Furthermore, in addition to or instead of changing the reliability according to the duration, the reliability may be changed according to the steering angle. The relationship between the steering angle and the reliability may be such that the reliability decreases linearly, curvedly, or in stages as the steering angle increases. Note that the steering angle in this specification is an absolute value, and the steering angle increases both when the steering wheel is rotated left from 0 degrees, which is the steering angle when traveling straight, and when the steering wheel is rotated right.

This embodiment 1.3 or the above embodiment 1.2 can also be combined with embodiment 1.1. Thus, the confidence level may vary based on the speed of the vehicle and the degree of curvature or steering angle in the direction the vehicle is traveling.

For example, if the vehicle speed is below a threshold, the reliability may be changed according to the steering angle. Also, if the vehicle speed is below a threshold, the reliability may be changed according to the vehicle speed and the steering angle. In this way, the reliability of a target detected when turning right or left at an intersection can be lowered. As a result, even if a pedestrian is mistakenly detected as crossing the road after a right or left turn instead of crossing the road before the turn, the reliability of the pedestrian's position can be lowered.

[Embodiment 1.4]
When the reliability of the CPM is the reliability of the target position, the vehicle may change the reliability of the target position based on the distance to the detected target. The vehicle may control the reliability so that the reliability decreases as the distance to the detected target increases, regardless of the distance range to the target. The relationship between the distance to the target and the reliability may be such that the reliability decreases linearly, curvedly, or in stages as the distance to the target increases. In addition, the vehicle may calculate the reliability of a target whose distance is equal to or greater than a certain value by subtracting or multiplying a predetermined value based on the reliability of a target whose distance is less than a certain value (assuming that conditions other than the distance are the same).

[Modification of the first embodiment]
Instead of calculating the reliability or including the reliability in the CPM and transmitting it, the vehicle may include information for calculating the reliability in the CPM and transmit it. In this case, the receiving vehicle that receives the CPM can calculate the reliability of the CPM based on the information, and the load of calculating the reliability in the CPM transmitting vehicle can be reduced.

The information for calculating the reliability may be at least one of the following: information on the vehicle speed in embodiment 1.1; information on whether the vehicle is moving straight or not (or steering angle information) in embodiment 1.2; the above-mentioned time (duration) in embodiment 1.3; and the distance to the target in embodiment 1.4.

If the CPM is a first message, the vehicle may transmit information for calculating the reliability using a second message (e.g., CAM) different from the first message. In other words, the message including the position of the target detected by the sensor and the message indicating the reliability of the information regarding the orientation of the sensor may be separate messages. The second message may be transmitted simultaneously with the first message, or may be transmitted at a different time (e.g., relatively close to the first message). It is sufficient that the second message is linked to the first message.

[Modification 2 of the first embodiment]
The vehicle may control not to transmit the CPM in cases where the reliability is low (for example, when the speed of the vehicle is low, or when the steering angle is equal to or greater than a threshold). In this case, the vehicle receiving the CPM may assume that the reliability of the received CPM is high. Note that the vehicle may not need to calculate the reliability in cases where the reliability is low. Whether or not the case is one in which the reliability is low may be determined based on information for calculating the reliability.

The vehicle may also calculate the reliability and control not to transmit the CPM if the calculated reliability is less than the transmission decision threshold. The transmission decision threshold is a value that is set in advance. The transmission decision threshold may be, for example, a reliability corresponding to the speed threshold shown in embodiment 1.1, or a value lower than that.

According to the first embodiment described above, a vehicle can effectively inform other vehicles via the CPM that, for example, the reliability of the orientation of its own sensor is low.

Second Embodiment
The second embodiment relates to control of the receiving side of the CPM.

In the second embodiment, when the received CPM includes the reliability described in the first embodiment, the vehicle may determine whether or not to use the CPM for estimating the position of a target based on the reliability. For example, the vehicle may determine to use the CPM for estimating the position of a target when the reliability is equal to or greater than a threshold, and may determine not to use the CPM for estimating the position of a target when the reliability is less than the threshold.

The vehicle may determine whether to use a received CPM for estimating the position of a target based on the state of the vehicle from which the CPM was transmitted. For example, the vehicle may preferentially trust a CPM received from a vehicle traveling straight over a CPM received from a vehicle turning, in other words, use the CPM for estimating the position of a target. A specific example of preferential use will be described. When a CPM containing information about the same target is received from both a vehicle traveling straight and a vehicle turning, the position of the target can be estimated using the CPM received from the vehicle traveling straight. Also, when a CPM containing information about the same target is received from both a vehicle traveling straight and a vehicle turning, and each CPM contains a reliability, the one with the higher reliability may be used to estimate the position of the target.

Another example of a vehicle state that determines whether or not to use a CPM to estimate the position of a target is the vehicle speed. If the speed of the vehicle that transmitted the CPM is less than the threshold described in embodiment 1.1, the receiving vehicle may decide not to use the received CPM to estimate the position of the target. The vehicle speed is an example of information for calculating reliability. A vehicle that receives a CPM may decide whether or not to use the received CPM to estimate the position of a target based on the information for calculating reliability.

In addition, if the received CPM includes the reliability of the information on the sensor orientation, the receiving vehicle may determine whether to use the received CPM for estimating the position of the target based on the reliability, without judging the state of the vehicle that transmitted the CPM. If the CPM is a first message, the state of the vehicle (speed, steering angle, yaw rate, etc.) may be transmitted using a second message (e.g., CAM) different from the first message. Note that the yaw rate is information for judging whether the vehicle that transmitted the CPM is turning. The second message may be transmitted from the same vehicle at the same time as the first message, or at a different time (e.g., relatively close to the first message). It is sufficient that the second message is linked to the first message.

The receiving vehicle may calculate the reliability of the CPM based on the information for calculating the reliability described in the modified example of the first embodiment, and may determine whether or not to use the CPM to estimate the position of a target based on the information.

According to the second embodiment described above, the vehicle can appropriately determine, for example, whether or not to use the received CPM to estimate the position of a target.

(Hardware configuration)
FIG. 5 is a diagram showing an example of a vehicle 10 according to an embodiment. The vehicle 10 includes a control unit 11, a sensor 12, a locator 13, an input/output unit 14, and a communication unit 15. The block diagram shown in this example shows functional blocks. Each of these functional blocks (components) is realized by any combination of at least one of hardware and software. Note that the "vehicle" described in the above embodiment may be read as any one or more functional blocks (e.g., the control unit 11, the communication unit 15) in the vehicle 10.

Figure 5 shows only the parts necessary for explaining the present disclosure. The vehicle 10 includes parts necessary for driving, such as a drive unit and an operating unit. The drive unit is, for example, one or both of an engine and a motor. The operating unit is, for example, a steering wheel.

The control unit 11 is composed of a microprocessor (hereinafter simply referred to as the processor) 111, a memory 112, and a communication interface 113. The communication interface 113 is, for example, an input/output (IO) port. The control unit 11 may be called an electronic control unit (ECU), or may be composed of a central processing unit (CPU) including interfaces with peripheral devices, a control device, an arithmetic unit, registers, etc.

The control unit 11 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and the processing of the processor 111 may be realized using the hardware. For example, the processor 111 may be implemented using at least one of these pieces of hardware.

Each function of the vehicle 10 (e.g., message generation, processing based on information from the sensor 12) may be realized, for example, by loading a specific software (program) onto hardware such as the processor 111 and memory 112, so that the processor 111 performs calculations, controls communication via the communication unit 15, and controls at least one of reading and writing data in the memory 112.

The processor 111 may, for example, operate an operating system to control the entire in-vehicle computer. The processor 111 may also read programs, software modules, data, etc. into the memory 112 and execute various processes according to these. The program may be a program for causing the computer to execute at least a portion of the operations described in the above-mentioned embodiments. The program may be read as program code.

The memory 112 is a computer-readable recording medium and may be composed of at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically EPROM (EEPROM), a Random Access Memory (RAM), or other suitable storage medium. The memory 112 may also be called a register, a cache, a main memory, or the like. The memory 112 may store executable programs, software modules, and the like for implementing a method according to an embodiment of the present disclosure.

The control unit 11 may include a storage (auxiliary storage device) that is a computer-readable recording medium with a larger capacity than the memory 112. The control unit 11 may read and write data to and from the memory 112 to the storage. The storage is not limited to being provided in the control unit 11, and may be independent of the control unit 11 and connected to the control unit 11 via a communication line.

The communication interface 113 may be called an input/output port, and may be used to exchange information between the control unit 11 and other blocks. The other blocks are, for example, blocks used for operation. The control unit 11 may obtain signals from the sensors 12 via the communication interface 113.

The control unit 11 may provide driving assistance functions, autonomous driving functions, etc., based on an Inertial Navigation System (INS), an Artificial Intelligence (AI) chip, an AI processor, AI functions, etc.

The sensor 12 may include, for example, a current sensor, a wheel rotation speed sensor, a tire pressure sensor, a vehicle speed sensor, an acceleration sensor, an angular velocity sensor, an object detection sensor, and the like. Each sensor may provide a signal (on-off signal, analog signal, digital signal, etc.) obtained by measurement to the control unit 11 via the communication interface 113. For example, the object detection sensor may generate a detection signal when it detects a target such as an obstacle, a vehicle, or a pedestrian.

The sensor 12 may include a device capable of providing information on the environment surrounding the vehicle 10, such as a millimeter wave radar, a Light Detection and Ranging (LiDAR), a camera, or a gyro system (e.g., an Inertial Measurement Unit (IMU)). A plurality of sensors 12 may be mounted on the vehicle 10, and a plurality of sensors 12 of the same type may be mounted on the vehicle. For example, cameras serving as the sensor 12 may be mounted on the front, rear, and both sides of the vehicle 10.

The locator 13 acquires location information of the vehicle 10. The locator 13 may acquire the location information based on a positioning system (e.g., a satellite positioning system (Global Navigation Satellite System (GNSS), Global Positioning System (GPS), etc.)), map information (e.g., a High Definition (HD) map, an Autonomous Vehicle (AV) map, etc.), and the speed, acceleration, angular velocity, etc. obtained from the sensor 12 described above.

The input/output unit 14 includes an input device that accepts input from the outside and an output device that performs output to the outside. The input device is, for example, a keyboard, a mouse, a microphone, a switch, a button, or a sensor. The output device is, for example, a display, a speaker, or a Light Emitting Diode (LED) lamp. The input device and the output device may be integrated into one structure (for example, a touch panel).

The input/output unit 14 may be composed of various devices for providing various information such as driving information, such as a car navigation system, an audio system, a television, a radio, etc., and one or more ECUs for controlling these devices. The input/output unit 14 may provide various information/services to the occupants of the vehicle 10 by using information acquired from an external device (e.g., an ITS server 30) via the communication unit 15.

The input/output unit 14 may receive input through user operation, or may be connected to a specific device, storage medium, etc. to receive data input. The input/output unit 14 may output the input result to, for example, the control unit 11.

The input/output unit 14 may output data, content, etc. in a format that is perceptible to the user.

The communication unit 15 is hardware for wirelessly communicating with an external device (e.g., another vehicle 10, an ITS server 30, etc.), and is also referred to as, for example, a transmission/reception device, a network device, a network controller, a network card, a communication module, etc. The communication unit 15 may be configured to include a high-frequency switch, a duplexer, a filter, an amplifier, a frequency synthesizer, an antenna, etc. The communication unit 15 may be configured with a transmitter, a receiver, a transmission/reception circuit, or a transmission/reception device that are described based on a common understanding in the technical field to which the present disclosure relates.

The communication unit 15 supports, for example, Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or decimal)), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE Communication may be performed using 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), or other wireless communication methods, or wireless communication methods that are expanded, modified, created, or defined based on these.

The communication unit 15 may be controllable by the processor 111 of the control unit 11, and the communication unit 15 may be included in the control unit 11.

The communication unit 15 may transmit at least one of the signal from the sensor 12, information obtained based on the signal, information based on the input from the input/output unit 14, etc., to an external device via wireless communication.

The communication unit 15 may receive various information (traffic information, signal information, vehicle distance information, etc.) from an external device and provide it to the control unit 11. This information may be output via the input/output unit 14. The control unit 11 may perform control based on this information.

The method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically combined, or may be realized using two or more devices that are physically or logically separated and connected directly or indirectly (e.g., using wires, wirelessly, etc.). The functional block may be realized by combining the one device or the multiple devices with software.

For example, although only one processor 111 is shown, there may be multiple processors. Furthermore, processing may be performed by one processor, or processing may be performed by two or more processors simultaneously, sequentially, or using other techniques. Furthermore, processor 111 may be implemented by one or more chips.

The hardware of each functional block may be connected by a bus for communicating information. The bus may be configured using a single bus, or may be configured using different buses between each device. The bus may be realized by a wired or wireless system.

The RSU 20, ITS server 30, etc. may also have the same configuration as the vehicle 10. A person skilled in the art would be able to understand the descriptions related to the vehicle 10 by appropriately interpreting them.

In addition, the configuration of the vehicle 10 including the control unit 11 or the configuration including the control unit 11 and the communication unit 15 may be referred to as a message control device.

The control unit 11 may generate a message including the position of the target detected by the sensor 12 and a message indicating the reliability of the information regarding the orientation of the sensor 12. The communication unit 15 may transmit the message.

The message may include a reliability. The message may include information for calculating the reliability.

The control unit 11 may determine the reliability based on the speed of the vehicle in which the sensor 12 is installed.

The control unit 11 may determine the reliability based on the degree to which the direction in which the vehicle in which the sensor 12 is mounted is curved.

The control unit 11 may determine the reliability based on the vehicle's speed and the degree to which the direction in which the vehicle is traveling is curved.

The reliability of the information regarding the orientation of the sensor 12 is the reliability of the target position, and the control unit 11 may change the reliability of the target position depending on the distance to the target.

The control unit 11 may generate a message including the position of the target detected by the sensor 12. The communication unit 15 may transmit the message. The control unit 11 may determine whether or not to transmit the message from the communication unit 15 based on the reliability of the information about the orientation of the sensor 12 or information for calculating the reliability.

The communication unit 15 may receive a message including the target position and the reliability or information for calculating the reliability of the information regarding the orientation of the sensor 12.

The control unit 11 may determine the relative position of the target based on the message received by the communication unit 15. The control unit 11 may determine whether or not to use the target position included in the message for estimating the target position based on the reliability that can be determined from the reliability or information for calculating the reliability.

(Modification)
In addition, terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings.

In this disclosure, terms such as apparatus, circuit, device, section, and unit may be read interchangeably.

The term "vehicle" in the present disclosure may be interpreted as any moving object. Examples of moving objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon.

The moving body may be a moving body that travels autonomously based on an operating command. The moving body may be a moving body that moves with a person on board, in other words a vehicle (e.g., a car, an airplane, etc.), or it may be an unmanned moving body (e.g., a drone, an autonomous vehicle, etc.). The moving body may be a robot. The robot may be manned or unmanned.

The information, parameters, etc. described in this disclosure may be represented using absolute values, may be represented using relative values from a predetermined value, or may be represented using other corresponding information. For example, a radio resource may be indicated by a predetermined index.

The names used for parameters and the like in this disclosure are not limiting in any way. Furthermore, the formulas and the like that use these parameters may differ from those explicitly disclosed in this disclosure.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

The input and output information, signals, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information, signals, etc. may be overwritten, updated, or added to. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to another device.

Notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. Furthermore, notification of specific information (e.g., notification that "X is the case") is not limited to explicit notification, and may be performed implicitly (e.g., by not notifying the specific information or by notifying other information).

Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Software, instructions, information, etc. may also be transmitted and received via a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and/or wireless technologies (such as infrared, microwave), then these wired and/or wireless technologies are included within the definition of a transmission medium.

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched between depending on the implementation. In addition, the processing procedures, sequences, flow charts, etc. of each aspect/embodiment described in this disclosure may be rearranged as long as there is no inconsistency. For example, the methods described in this disclosure present elements of various steps using an exemplary order, and are not limited to the particular order presented.

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

Any reference to elements using designations such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must precede the second element in some way.

In this disclosure, "A/B" and "at least one of A and B" may be interpreted as interchangeable. Also, in this disclosure, "A/B/C" may mean "at least one of A, B, and C."

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Additionally, the term "or," as used in this disclosure, is not intended to be an exclusive or.

In this disclosure, where articles have been added through translation, such as a, an, and the in English, this disclosure may include that the nouns following these articles are in the plural form.

In this disclosure, terms such as "less than", "less than", "greater than", "more than", "equal to", etc. may be read as interchangeable. In addition, in this disclosure, terms meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read as interchangeable, not limited to positive, comparative and superlative. In addition, in this disclosure, terms meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read as interchangeable, not limited to positive, comparative and superlative, as expressions with "ith" (i is any integer) (for example, "best" may be read as "ith best").

In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

Although the invention according to the present disclosure has been described in detail above, it is clear to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described herein. The invention according to the present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the invention as determined based on the description of the present disclosure. Therefore, the description of the present disclosure is intended as an illustrative example and does not have any restrictive meaning on the invention according to the present disclosure.

Claims (11)

a control unit for generating a message including the position of a target detected by a sensor and a message indicating a degree of confidence in the information on the orientation of the sensor;
A message control device having a communication unit that transmits the message. The message control device according to claim 1, wherein the message includes the reliability. The message control device according to claim 1, wherein the message includes information for calculating the reliability. The message control device according to claim 2, wherein the control unit determines the reliability based on the speed of the vehicle on which the sensor is mounted. The message control device according to claim 2, wherein the control unit determines the reliability based on the degree to which the direction in which the vehicle in which the sensor is mounted is moving is curved. The message control device according to claim 4, wherein the control unit determines the reliability based on the speed of the vehicle and the degree to which the direction in which the vehicle is traveling is curved. the reliability of the information about the orientation of the sensor is the reliability of the position of the target,
The message control device according to claim 2 , wherein the control unit changes a reliability of the position of the target according to a distance to the target. a control unit for generating a message including a position of a target detected by the sensor;
A communication unit for transmitting the message,
The control unit determines whether or not to transmit the message from the communication unit based on reliability of information relating to an orientation of the sensor or information for calculating the reliability. a communication unit that receives a message including a target position and a reliability of information on the sensor orientation or information for calculating the reliability;
and a control unit that determines a relative position of a target based on the received message,
The control unit determines whether or not to use the target position included in the message for estimating the target position based on the reliability or the reliability that can be determined by information for calculating the reliability. generating a message including the position of the target detected by the sensor and a message indicating a confidence level of the information regarding the orientation of the sensor;
A message control method for transmitting the message. A vehicle having a message control device according to any one of claims 1 to 9.

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