JP7134386B1 - Driving support device, driving support method, and driving support program - Google Patents

Abstract

A downstream monitoring unit (211) acquires downstream quality information from a vehicle. A base station area calculator (212) calculates a base station coverage area based on the downlink quality information. An uplink monitoring unit (213) acquires uplink quality information from the base station. A vehicle area calculation unit (214) calculates a coverage area of the vehicle based on the upstream quality information. A dead area estimation unit (215) estimates a dead area based on the coverage area of the base station and the coverage area of the vehicle. A driving support unit (230) transmits treatment information for the dead area to the vehicle.

Description

The present disclosure relates to technology for assisting driving of a vehicle that communicates with a base station.

In a conventional traffic system, vehicle information is collected by a sensor or the like mounted on a vehicle, and the collected information is transmitted from the vehicle to a driving support device via a base station. Transportation systems are used for things such as automated driving.
In addition, roadside units are installed at intersections and the like. Then, traffic information is collected by a sensor or the like mounted on the roadside device, and the traffic information is transmitted from the roadside device to the driving support device via the base station. The driving support device is a management server such as an edge computer. A specific example of an edge computer is Multi-access Edge Computing (MEC).

Vehicle information and traffic information are used to generate information for driving assistance.
Information for driving support is transmitted from the driving support device to the on-vehicle communication device via the base station. An in-vehicle communication device is mounted in a vehicle.
In vehicles, information for driving assistance is used for safe driving or automatic driving.

In this way, the driving support device collects vehicle information from vehicles and traffic information from roadside units by upstream communication via base stations.
Then, the driving support device generates information for driving support and distributes it by downlink communication via the base station.

In a transportation system linked to infrastructure, a driving support system that provides driving support information to vehicles in real time without interruption is desired.
In the driving assistance system, a dead area may occur within the communication area of the base station. A dead area is an area where the reception level is lowered. For example, the dead area is generated at the end of the communication area or due to the presence of a shield such as a building that makes it difficult for radio waves to reach the area.
In this case, it is desirable to take measures so as not to impede safe driving or automatic driving of the vehicle, which may move within the dead area. For example, it is desirable to take measures such as avoiding traveling in the dead area or avoiding the influence in the dead area.

Japanese Patent Laid-Open No. 2002-200003 discusses a technique for dealing with problems in advance. Specifically, it is being considered to divide the communication area of a base station into a plurality of partial areas and estimate a dead area using reception sensitivity distribution information for each partial area. The reception sensitivity distribution information is communication quality information in downlink communication and indicates reception sensitivity.

JP 2018-207154 A

In Patent Document 1, the coverage area of the base station is considered, but the coverage area of the vehicle is not considered.
The coverage area of the base station is the area where the radio waves transmitted from the base station reach the vehicle.
A vehicle coverage area is an area in which radio waves transmitted from a vehicle reach a base station.

An object of the present disclosure is to enable driving assistance in consideration of the coverage area of the vehicle.

The driving support device of the present disclosure is
a downlink monitoring unit that acquires from the vehicle downlink quality information indicating the quality of downlink communication from the base station to the vehicle;
a base station area calculation unit that calculates a coverage area in which the base station can communicate based on the downlink quality information;
an uplink monitoring unit that acquires from the base station uplink quality information indicating the quality of uplink communication from the vehicle to the base station;
a vehicle area calculation unit that calculates a coverage area in which the vehicle can communicate based on the upstream quality information;
a dead area estimation unit for estimating a dead area where communication quality between the base station and the vehicle is degraded based on the coverage area of the base station and the coverage area of the vehicle;
and a driving support unit configured to transmit treatment information indicating treatment for the dead area to the vehicle.

According to the present disclosure, it is possible to provide driving assistance in consideration of the coverage area of the vehicle.

1 is a configuration diagram of a driving support system 100 according to Embodiment 1. FIG. 1 is a configuration diagram of a driving support device 200 according to Embodiment 1. FIG. 3 is a block diagram of base station 300 in Embodiment 1. FIG. 2 is a configuration diagram of a roadside device 400 according to Embodiment 1. FIG. 1 is a configuration diagram of vehicle 500 according to Embodiment 1. FIG. 4 is a flowchart of a driving support method according to Embodiment 1; 4 is a flowchart of dead area monitoring processing according to Embodiment 1; FIG. 2 is an explanatory diagram of areas according to Embodiment 1; 4 is a diagram showing an example of the size of a dead area according to Embodiment 1; FIG. FIG. 4 is a configuration diagram of a dead area monitoring unit 210 according to Embodiment 2; FIG. 10 is a diagram showing an example of factors of dead areas according to the second embodiment; FIG. 10 is a flowchart of dead area monitoring processing according to the second embodiment; 2 is a hardware configuration diagram of a driving assistance device 200 according to an embodiment; FIG.

The same or corresponding elements are denoted by the same reference numerals in the embodiments and drawings. Descriptions of elements having the same reference numerals as those described will be omitted or simplified as appropriate.

Embodiment 1.
A driving support system 100 will be described with reference to FIGS. 1 to 9. FIG.

*** Configuration description ***
The configuration of the driving support system 100 will be described based on FIG.
The driving support system 100 includes a driving support device 200 , one or more base stations 300 , and one or more roadside devices 400 .
The driving support device 200 communicates with one or more base stations 300 by wire or wirelessly. The driving support device 200 also communicates with one or more roadside units 400 and one or more vehicles 500 via the base station 300 .
The base station 300 wirelessly communicates with one or more vehicles 500 either directly or through the roadside unit 400 .

The configuration of the driving support device 200 will be described based on FIG.
The driving support device 200 is a computer including hardware such as a processor 201 , a memory 202 , a storage 203 and a communication device 204 . The driving support device 200 also includes hardware such as an input/output interface.
These pieces of hardware are connected to each other via signal lines.

A processor 201 is an IC that performs arithmetic processing and controls other hardware. For example, processor 201 is a CPU.
IC is an abbreviation for Integrated Circuit.
CPU is an abbreviation for Central Processing Unit.

Memory 202 is a volatile or non-volatile storage device. Memory 202 is also referred to as main storage or main memory. For example, memory 202 is RAM. Data stored in the memory 202 is saved in the storage 203 as needed.
RAM is an abbreviation for Random Access Memory.

Storage 203 is a non-volatile storage device. For example, storage 203 is ROM, HDD, flash memory, or a combination thereof. Data stored in the storage 203 is loaded into the memory 202 as needed.
ROM is an abbreviation for Read Only Memory.
HDD is an abbreviation for Hard Disk Drive.

Communication device 204 is a receiver and transmitter. For example, communication device 204 is a communication chip or NIC. Communication of the driving support device 200 is performed using the communication device 204 . Communication device 204 functions as communication unit 280 .
NIC is an abbreviation for Network Interface Card.

The driving assistance device 200 includes elements such as a dead area monitoring unit 210 , a travel prediction unit 220 and a driving assistance unit 230 .
The dead area monitoring section 210 includes a downlink monitoring section 211 , a base station area calculation section 212 , an uplink monitoring section 213 , a vehicle area calculation section 214 and a dead area estimation section 215 .
These elements are implemented in software.

The storage 203 stores a driving support program for causing the computer to function as a dead area monitoring section 210 , a travel prediction section 220 and a driving support section 230 . The driving assistance program is loaded into memory 202 and executed by processor 201 .
The storage 203 also stores an OS. At least part of the OS is loaded into memory 202 and executed by processor 201 .
The processor 201 executes the driving assistance program while executing the OS.
OS is an abbreviation for Operating System.

Input/output data of the driving assistance program is stored in the storage unit 290 .
Storage 203 functions as storage unit 290 . However, a storage device such as the memory 202 , a register within the processor 201 and a cache memory within the processor 201 may function as the storage unit 290 instead of the storage 203 or together with the storage 203 .

Driving assistance device 200 may include a plurality of processors that substitute for processor 201 .

The driving support program can be recorded (stored) in a non-volatile recording medium such as an optical disc or flash memory in a computer-readable manner.

The configuration of base station 300 will be described based on FIG.
Base station 300 includes hardware such as processor 301 , storage device 302 and communication device 303 . These pieces of hardware are connected to each other via signal lines.
The storage device 302 is memory and storage.

The configuration of the roadside unit 400 will be described based on FIG.
The roadside device 400 includes hardware such as a processor 401 , a storage device 402 , a communication device 403 , a roadside camera 411 and a radar sensor 412 . These pieces of hardware are connected to each other via signal lines.
The roadside camera 411 is a camera mounted on the roadside device 400 .

The configuration of vehicle 500 will be described based on FIG.
Vehicle 500 includes hardware such as processor 501 , storage device 502 and communication device 503 .
The vehicle 500 includes sensors such as an onboard camera 511 , a radar sensor 512 , a positioning receiver 513 , a vehicle speed sensor 514 and a gyro sensor 515 . A sensor is a type of hardware.
Vehicle 500 includes hardware such as display 521 , speaker 522 and input device 523 .
These pieces of hardware are connected to each other via signal lines.
These pieces of hardware are collectively referred to as an in-vehicle device 509 .

Vehicle-mounted camera 511 is a camera mounted on vehicle 500 .
The positioning receiver 513 is a satellite positioning system receiver. The satellite positioning system is called Global Navigation Satellite System (GNSS). A specific example of a satellite positioning system is the Global Positioning System (GPS).
The input device 523 is, for example, a microphone, buttons, and a touch panel.

***Description of operation***
A procedure of operation of the driving assistance system 100 (in particular, operation of the driving assistance device 200) corresponds to a driving assistance method. Further, the operation procedure of the driving assistance device 200 corresponds to the procedure of processing by the driving assistance program.

A driving assistance method will be described based on FIG.
Processing (1) will be described. Process (1) is periodically executed.
In the driving support device 200 , the driving support unit 230 acquires vehicle surrounding information from each vehicle 500 . Further, the driving support unit 230 acquires roadside unit peripheral information from each roadside unit 400 .

In each vehicle 500 , an in-vehicle device 509 transmits vehicle surrounding information to the driving support device 200 via the base station 300 .
The vehicle peripheral information indicates the situation around the vehicle 500 . Vehicle peripheral information is obtained using an onboard camera 511 and a radar sensor 412 .

Each roadside device 400 transmits the roadside device peripheral information to the driving support device 200 via the base station 300 .
The roadside machine peripheral information indicates the situation around the roadside machine 400 . For example, the roadside unit peripheral information includes traffic information and environmental information. The roadside machine peripheral information is acquired using the roadside camera 411 and the radar sensor 412 .

In the driving support device 200, the driving support unit 230 generates driving support information based on the acquired vehicle peripheral information and the acquired roadside unit peripheral information.
Then, the driving support unit 230 distributes the driving support information to each vehicle 500 via each base station 300 .
The travel support information is information for assisting the travel of vehicle 500 . The driving support information includes roadside unit peripheral information.

Processing (2-1) will be described.
In the driving support device 200 , the outbound monitoring unit 211 acquires vehicle information from each vehicle 500 . Also, the downlink monitoring unit 211 acquires roadside device information from each roadside device 400 .
Furthermore, the uplink monitoring unit 213 acquires base station information from each base station 300 .
Vehicle information, roadside device information and base station information are obtained periodically.

In each vehicle 500 , an in-vehicle device 509 transmits vehicle information to the driving support device 200 via the base station 300 .
Vehicle information includes vehicle identifiers, base station identifiers, downlink quality information, vehicle position information, and travel information.
The vehicle identifier identifies vehicle 500 .
The base station identifier identifies base station 300 .
Downlink quality information indicates the quality of communication (downlink communication) from base station 300 identified by the base station identifier to vehicle 500 . The quality of downlink communication is determined by communication device 503 based on the signal transmitted from base station 300 to vehicle 500 . Specifically, communication device 503 receives a signal transmitted from base station 300 to vehicle 500 and calculates the reception level of the received signal. The calculated reception level indicates the quality of downstream communication. The received level corresponds to received power.
The vehicle position information indicates the position of vehicle 500 . The position of vehicle 500 is calculated by positioning receiver 513 . However, the position of vehicle 500 may be calculated by processor 501 using data obtained by positioning receiver 513, vehicle speed sensor 514, and gyro sensor 515, respectively.
The travel information indicates the travel status of vehicle 500 . Specifically, the travel information indicates the traveling direction of the vehicle 500 . The traveling direction of vehicle 500 is measured by gyro sensor 515 .

Each roadside device 400 transmits roadside device information to the driving support device 200 via the base station 300 .
The roadside unit information includes a roadside unit identifier, traffic information and environment information.
The roadside device identifier identifies the roadside device 400 .
The traffic information indicates traffic conditions of the road on which the roadside unit 400 is installed.
The environment information indicates the environment of the place where the roadside unit 400 is installed.
Traffic information and environmental information are acquired using roadside cameras 411 and radar sensors 412 .

Each base station 300 transmits base station information to the driving support device 200 .
The base station information includes base station identifiers, vehicle identifiers and uplink quality information.
The upstream quality information indicates the quality of communication (uplink communication) from vehicle 500 identified by the vehicle identifier to base station 300 . The quality of uplink communication is determined by communication device 303 based on the signal transmitted from vehicle 500 to base station 300 . Specifically, communication device 303 receives a signal transmitted from vehicle 500 to base station 300 and calculates the reception level of the received signal. The calculated reception level indicates the quality of upstream communication. The received level corresponds to received power.

In the driving support device 200, the downlink monitoring unit 211 registers the downlink quality information on the monitoring map in association with the position indicated by the vehicle position information for each vehicle information.
A surveillance map is a map showing an area to be monitored. The surveillance map data is pre-stored in the storage unit 290 .

In addition, the downlink monitoring unit 211 registers traffic information and environment information in the monitoring map in association with the position of the roadside unit 400 for each roadside unit information.
The position of each roadside unit 400 is known. For example, a roadside device list is stored in advance in the storage unit 290 . The roadside device list indicates the position of each roadside device 400 and the like.

Furthermore, the uplink monitoring unit 213 extracts the vehicle position information from the vehicle information including the same vehicle identifier as the vehicle identifier included in the base station information for each base station information.
Then, the uplink monitoring unit 213 registers the uplink quality information on the monitoring map in association with the position indicated by the vehicle position information for each base station information.

Processing (2-2) will be explained.
In the driving assistance device 200, the base station area calculator 212 calculates the coverage area of each base station 300 based on the location of the base station 300, base station performance information, and propagation characteristic information.
The coverage area of the base station 300 is the range within which radio waves transmitted from the base station 300 reach. In other words, the coverage area of base station 300 is the range in which communication from base station 300 to vehicle 500 is possible.
The location of base station 300 is known. For example, a base station list is pre-stored in the storage unit 290 . The base station list indicates the position of each base station 300 and the like.
Base station performance information indicates the transmission performance of base station 300 . The base station performance information is pre-stored in the storage unit 290 .
The propagation characteristic information indicates the propagation characteristic of radio waves. For example, propagation characteristics are indicated by attenuation of radio waves. The propagation characteristic information may be pre-stored in the storage unit 290, or may be generated by calculating a radio wave propagation formula. The radio wave propagation formula is a formula for calculating the attenuation of radio waves, and is used when the base station 300 is installed or when the base station 300 is designed. When the radio wave propagation formula is used, the base station area calculation unit 212 may calculate the radio wave propagation formula after correcting the radio wave propagation formula based on the downlink quality information acquired from the vehicle 500 communicating with the base station 300. good.

In the driving support device 200 , the vehicle area calculation unit 214 calculates the coverage area of each vehicle 500 based on the position of the vehicle 500 , vehicle performance information, and propagation characteristic information.
The coverage area of vehicle 500 is a range within which radio waves transmitted from vehicle 500 reach. In other words, the coverage area of vehicle 500 is a range in which communication from vehicle 500 to base station 300 is possible.
The position of vehicle 500 is indicated by vehicle position information acquired from vehicle 500 .
The vehicle performance information indicates the transmission performance of vehicle 500 . The transmission performance of vehicle 500 is estimated by vehicle area calculation section 214 as follows. First, the vehicle area calculator 214 calculates the difference between the reception level indicated by the downlink quality information and the reception level indicated by the uplink quality information. The calculated difference is called a level difference. Next, vehicle area calculation section 214 calculates the difference in the transmission performance of vehicle 500 with respect to the transmission performance of base station 300 based on the level difference. The calculated difference is called the performance difference. Vehicle area calculation section 214 then estimates the transmission performance of vehicle 500 based on the performance difference and the base station performance information. However, the vehicle performance information of each vehicle 500 may be stored in the storage unit 290 in advance.
The propagation characteristic information is the same as the information used by base station area calculator 212 . For example, in the 5G system, two-way communication is performed by time division duplex (TDD), so it is considered that the propagation characteristics of radio waves from vehicle 500 are equivalent to the propagation characteristics of radio waves from base station 300 . Therefore, the propagation characteristic information used by the base station area calculator 212 is used. When the radio wave propagation formula is used, the vehicle area calculation unit 214 may calculate the radio wave propagation formula after correcting the radio wave propagation formula based on the upstream quality information acquired from the base station 300 communicating with the vehicle 500. .

The coverage area of each base station 300 and the coverage area of each vehicle 500 change according to changes in acquired base station information or acquired vehicle information.

Processing (2-3) will be described.
In the driving assistance device 200, the dead area estimation unit 215 estimates the dead area based on the monitoring map, the coverage area of each base station 300, and the coverage area of each vehicle 500 for each pair of the base station 300 and the vehicle 500. .
Then, dead area estimation section 215 registers a dead area on the monitoring map for each set of base station 300 and vehicle 500 .
A dead area is an area where communication quality may deteriorate. In other words, the dead area is an area where communication between base station 300 and vehicle 500 is difficult.
Details of the dead area will be described later.

The dead area monitoring process will be described with reference to FIG.
The dead area monitoring process is performed by the dead area monitoring unit 210 and corresponds to the processes (2-1) to (2-3).

Steps S111 to S114 correspond to the process (2-1).
In step S<b>111 , the outbound monitoring unit 211 acquires vehicle information from each vehicle 500 .
In step S<b>112 , the uplink monitoring unit 213 acquires base station information from each base station 300 .
In step S<b>113 , the downlink monitoring unit 211 acquires roadside device information from each roadside device 400 .
In step S114, the downlink monitoring unit 211 registers the downlink quality information on the monitoring map in association with the position indicated by the vehicle position information for each vehicle information.
In addition, the downlink monitoring unit 211 registers traffic information and environment information in the monitoring map in association with the position of the roadside unit 400 for each roadside unit information.
Further, the uplink monitoring unit 213 registers the uplink quality information on the monitoring map in association with the position indicated by the vehicle position information corresponding to the base station information for each base station information.

Steps S121 and S122 correspond to processing (2-2).
In step S<b>121 , the base station area calculator 212 calculates the coverage area for each base station 300 .
In step S<b>122 , the vehicle area calculator 214 calculates the coverage area for each base station 300 .

Steps S131 and S132 correspond to processing (2-3).
In step S<b>131 , the dead area estimation unit 215 estimates the dead area for each set of base station 300 and vehicle 500 based on the monitoring map, the coverage area of each base station 300 , and the coverage area of each vehicle 500 .
In step S<b>132 , the dead area estimation unit 215 registers dead areas on the monitoring map for each set of the base station 300 and the vehicle 500 .

Returning to FIG. 6, the description is continued.
Processing (3) will be described.
In the driving support device 200, the travel prediction unit 220 predicts the travel route for each vehicle 500 based on the vehicle position information and the travel information.

Processing (4) will be described.
In the driving support device 200 , the travel prediction unit 220 determines whether the vehicle 500 travels in the dead area based on the monitoring map and the predicted travel route for each vehicle 500 .
When the vehicle 500 travels in the dead area, the base station 300 is located outside the coverage area of the vehicle 500 or the vehicle 500 is located outside the coverage area of the base station 300 . As a result, the quality of uplink or downlink communication is degraded.

The driving support unit 230 performs the following processing for each vehicle 500 predicted to travel in the dead area.
First, the driving support unit 230 calculates a predicted position and predicted time.
The predicted position is the position of the dead area where the vehicle 500 is predicted to enter.
The predicted time is the time when vehicle 500 is predicted to enter the dead area.
Driving support unit 230 also generates treatment information for vehicle 500 .
The treatment information indicates treatment for the dead area. In other words, the action information indicates actions to ensure the quality of uplink and downlink communications. Specifically, the action information indicates information necessary for switching communication with the base station 300 to communication with another base station 300 or communication with the base station 300 via vehicle-to-vehicle communication. Alternatively, the treatment information indicates information necessary for traveling in the dead area. Treatment information may indicate both required information.
For example, the driving support unit 230 selects candidate base stations or candidate vehicles. Then, the driving support unit 230 generates information indicating the action of switching the communication partner from the current base station 300 to a candidate base station or a candidate base station. The generated information is action information.
A candidate base station is another base station 300 for which communication quality is ensured.
The candidate vehicle is another vehicle 500 for which communication quality is ensured in inter-vehicle communication. Information sent and received by vehicle 500 is communicated via other vehicles 500 .
The action information may indicate handover instructions or blind area travel information. The dead area travel information is information necessary for traveling in the dead area. For example, when there are no candidate base stations and no candidate vehicles, the driving support unit 230 generates action information indicating dead area travel information.
Driving support unit 230 then transmits the notification information to vehicle 500 via base station 300 . The notification information includes predicted position information, predicted time information, and action information.

Processing (5) will be described.
In each vehicle 500, an in-vehicle device 509 receives notification information.
Next, the in-vehicle device 509 determines treatment based on the notification information. Note that the in-vehicle device 509 may choose to change the travel route so that the vehicle does not travel through the dead area. When only uplink communication is disabled, vehicle 500 can also travel in a dead area using information obtained through downlink communication until uplink communication is restored. In this case, changing the travel route is an effective measure.
Then, the in-vehicle device 509 executes the determined action before the quality of upstream communication or downstream communication deteriorates.
In-vehicle device 509 also transmits response information to driving support device 200 . Response information indicates the determined action.

The dead area will be described with reference to FIGS. 8 and 9. FIG.
In FIG. 8, (A) to (G) are as follows.
(A) shows the vehicle coverage area.
(B) shows the coverage area of the base station a.
(C) shows the coverage area of the base station b.
(D) shows the dead area. Due to shielding factors such as buildings, the coverage area of the base station a and the vehicle is reduced. An area in which the base station a is not included in the coverage area of the vehicle is the dead area.
(E) shows the coverage area of the vehicle in the blind area for the base station a.
(F) shows the coverage area of the base station a in the dead area.
(G) shows switching from base station a to base station b. Since there is no base station a in the coverage area of the vehicle, uplink communication to the base station a is impossible.

As shown in FIG. 8, when a vehicle travels behind a building or behind a truck, the communication quality may deteriorate and the travel area may become a dead area.
In other words, an area with a lower reception level than its surroundings may become a dead area. Such areas are identified based on communication quality information registered at each position on the surveillance map. The communication quality information is upstream quality information and downstream quality information.
The reception level of the coverage area is obtained as a result of radio wave propagation calculation. However, the wave propagation equation does not consider local wave attenuation. Therefore, it is considered that the reception level in the dead area is lower than the reception level obtained as a result of radio wave propagation calculation.
The amount of reception level attenuation due to the influence of shielding such as the shadow of a building can be estimated based on the amount of reduction in the reception level in the dead area.
The amount of reception level attenuation due to shielding can be known by referring to the surveillance map. Therefore, it is possible to calculate the coverage area of the vehicle in consideration of the amount of attenuation in the reception level due to the influence of shielding. In general, local shielding effects are not considered for vehicle coverage areas.
The coverage area of the vehicle when the amount of attenuation of the reception level due to the influence of shielding is taken into account is narrower than the area covered by the vehicle when the amount of attenuation is not taken into consideration. In a situation where the vehicle travels in the coverage area without consideration of the attenuation, it is possible to estimate whether or not there is a base station within the coverage area of the vehicle when the attenuation is taken into account. That is, it is possible to estimate whether uplink communication from the vehicle to the base station is possible. That is, it is possible to determine whether or not the travel area is a dead area for the vehicle.
Similarly, it is possible to calculate the coverage area of the base station when considering the amount of attenuation in the reception level due to the influence of shielding. Then, it is possible to estimate whether or not the vehicle is within the coverage area of the base station when the attenuation is taken into account in a situation where the vehicle travels in the coverage area when the attenuation is not taken into account. That is, it is possible to estimate whether downlink communication from the base station to the vehicle is possible. In other words, it is possible to determine whether or not the travel area is a dead area for the base station.

In FIG. 8, the coverage area of the base station a and the vehicle is reduced due to shielding factors such as buildings. However, since the vehicle is located in the coverage area of the base station a, downlink communication is possible. However, since the base station a is not included in the coverage area of the vehicle, uplink communication is impossible. Such an area is estimated as a dead area.

FIG. 9 shows an example of the size of the dead area.
The transmission performance of wireless devices may differ between base stations and vehicles. Moreover, there is a possibility that the transmission performance of the wireless device may differ between vehicles.
As shown in FIG. 9, the size of the dead area differs when the transmission performance of the wireless device is high in the order of the base station, vehicle a, and vehicle b. Specifically, the dead area is larger in order of uplink communication of vehicle b, uplink communication of vehicle a, and only downlink communication.

Even if there is no reception level attenuation due to the influence of shielding, radio wave attenuation due to communication distance is large at the end of the coverage area of a base station.
Therefore, upstream communication from a vehicle having lower transmission performance than that of a base station becomes difficult. If there is no base station in the area covered by the vehicle, the area covered by the vehicle becomes a blind area in which uplink communication is impossible.
That is, by considering uplink communication in addition to downlink communication, dead area (1) and dead area (2) can be estimated. A dead area (1) is a dead area only for uplink communication where there is no dead area for downlink communication. The dead area (2) is a dead area according to the transmission performance of each vehicle.
Then, it becomes possible to deal with such a dead area.

The travel prediction unit 220 estimates the possibility that the vehicle will travel through the dead area based on the estimated location of the dead area, the location of the base station, the current position of the vehicle, and the future travel route of the vehicle.
If there is a possibility that the vehicle will travel through the dead area, the driving assistance unit 230 notifies the vehicle to take action before traveling through the dead area.

*** Effect of Embodiment 1 ***
In a transportation system, when the transmission performance of a vehicle is lower than that of a base station, the quality of uplink communication (vehicle to base station) deteriorates before the quality of downlink communication (base station to vehicle). Transportation systems include automated driving through 5G infrastructure cooperation.
The driving assistance device 200 estimates a dead area according to each vehicle in consideration of the coverage area of uplink communication. In other words, the driving support device 200 presumes a dead area that cannot be estimated only by downlink communication. This makes it possible to avoid deterioration in communication quality. As a result, it becomes possible to realize an improvement in safety in running the vehicle.

*** Supplement to Embodiment 1 ***
The size of the coverage areas of base stations and vehicles varies depending on the reception level required for communication.
The reception level is related to communication speed. Therefore, the required reception level is determined by the required communication speed within the coverage area.
In the estimation of the dead area based on the coverage area, the communication speed required for normal operation of applications and services in the driving assistance system 100 may be considered. In that case, the coverage area for the required communication speed is calculated according to the application. In other words, the base station area calculation unit 212 and the vehicle area calculation unit 214 calculate the coverage area based on the communication quality required for realizing the application used in the driving support system 100 . Then, the dead area estimation unit 215 estimates the size of the dead area.
When an application transmits and receives large data such as map information necessary for driving a vehicle, it is necessary to increase the required communication speed. Therefore, the reception level that defines the coverage area is set high.
When small data such as control information necessary for running the vehicle is transmitted and received by the application, the required communication speed may be low. Therefore, the reception level that defines the coverage area is set low.
The data necessary for driving a vehicle is related to safety. Therefore, a margin may be given to the reception level that defines the coverage area so that such data can be transmitted and received reliably in real time.
Communication quality information indicating a drop in the reception level within the base station area and dead area information are sequentially acquired from each vehicle or roadside unit traveling within the coverage area of the base station. Communication quality information that indicates a drop in reception level during the past reference period is statistically processed. This increases the reliability of communication quality measurement.
Past information prior to the past reference period may not match the current situation due to changes in the surrounding environment. In order to eliminate the influence, the past information may be deleted and the information may be updated to the latest.
That is, dead area estimation section 215 estimates the dead area using the communication quality information (downlink quality information and uplink quality information) acquired during the past reference period. In this case, communication quality information obtained before the past reference period is not used. The past reference period is a period from the reference time to the estimated time. The reference time is the time before the estimated time by the reference time.
In addition, in the process (2-1) to the process (2-3), it is described that the dead area is estimated based on the reception level information in the uplink communication and the downlink communication. However, the image information obtained by the roadside camera 411 may be used for estimating the dead area. For example, an image may be used to confirm a shielding object that blocks radio waves from the base station 300, and information on the shielding object may be used to estimate the dead area. Specific examples of shielding objects are buildings such as buildings (fixed objects) and vehicles such as trucks (moving objects). Algorithms such as artificial intelligence (AI) may also be used to analyze images and data to improve the accuracy of estimating dead areas and communication quality.

Embodiment 1 shows an example of an automatic driving system based on 5G infrastructure cooperation. However, Embodiment 1 can also be applied to wireless communication (for example, LTE) different from 5G.

Embodiment 2.
A mode for determining the factors of dead areas will be described mainly with reference to FIGS. 10 to 12 for differences from the first embodiment.

*** Configuration description ***
The configuration of driving support system 100 is the same as the configuration in the first embodiment. However, the configuration of driving support device 200 is different from that in the first embodiment.

Based on FIG. 10, the configuration of the dead area monitoring unit 210 of the driving support device 200 will be described.
The dead area monitoring section 210 further includes a factor determination section 216 .

***Description of operation***
The operation of the factor determination unit 216 will be described.
The factor determination unit 216 determines factors of the dead area.
Specifically, the factor determination unit 216 determines which of the fixed object and the moving object is the factor of the dead area. In other words, the factor determination unit 216 determines whether the estimated dead area is a dead area caused by a fixed object or a dead area caused by a moving object.

FIG. 11 shows a specific example of factors of dead areas.
A concrete example of the fixed object in the dead area caused by the fixed object is a building such as a building.
A specific example of a moving object in the dead area caused by moving objects is a vehicle such as a truck.

The cause of the dead area is determined as follows.
The factor determining unit 216 determines the factor of the dead area based on the change in the position of the dead area and the peripheral information of the dead area. The peripheral information of the dead area is the vehicle peripheral information acquired from the vehicles 500 located around the dead area and the vehicle peripheral information acquired from the roadside units 400 located around the dead area.
For example, when the amount of change in the position of the dead area is smaller than the threshold, the factor determination unit 216 determines that the cause of the dead area is a fixed object. Further, when the amount of change in the position of the dead area is larger than the threshold, the factor determination unit 216 determines that the cause of the dead area is a moving object.

The factor determination unit 216 determines the estimation period based on factors for each dead area.
When the dead area is caused by a moving object, the movement of the moving object dynamically changes the position of the dead area. Therefore, the factor determination unit 216 determines a period shorter than the dead area estimation period caused by the fixed object as the dead area estimation period caused by the moving object.
For example, the estimation cycle of the dead area caused by fixed objects is a preset cycle (set cycle). In addition, the period for estimating the dead area caused by moving objects is determined by shortening the set period.

The dead area estimator 215 estimates each dead area at the determined estimation cycle.
A dead area caused by a fixed object is estimated using information from the vehicle 500 traveling around the fixed object and information from the roadside unit 400 around the fixed object. By statistically processing information from a plurality of vehicles 500, dead area estimating section 215 increases the accuracy of dead area estimation.
A dead area caused by a moving object is estimated using information from the vehicle 500 traveling around the moving object and information from the roadside unit 400 around the moving object. By statistically processing information from a plurality of vehicles 500, dead area estimating section 215 increases the accuracy of dead area estimation.

Based on FIG. 12, the dead area monitoring process will be described.
In step S210, the dead area estimation unit 215 estimates the dead area.
Step S210 corresponds to step S131 in the first embodiment.

In step S221, the factor determination unit 216 determines factors of the estimated dead area.
If the cause of the dead area is a moving object, the process proceeds to step S222.
If the cause of the dead area is a fixed object, the process proceeds to step S223.

In step S222, the factor determination unit 216 sets the estimated dead area cycle to a shortened cycle. The shortened period is shorter than the set period.

In step S223, the factor determination unit 216 sets the estimated period of the dead area to the set period. The set period is the period set for the fixed object.

After step S222 or step S223, the dead area estimation unit 215 estimates the dead area in an estimation cycle.

*** Effect of Embodiment 2 ***
The driving support device 200 determines whether the factor of the dead area is a fixed object or a moving object, and determines the estimation cycle of the dead area according to the factor. This makes it possible to estimate the dead area at the optimum cycle.

*** Supplement to Embodiment 2 ***
The driving support device 200 determines whether the cause of the dead area is a fixed object or a moving object. Then, the driving support device 200 notifies the vehicle to avoid the estimated dead area.
However, the situation on the infrastructure side such as the base station may be changed using the dead area estimation result so as to eliminate the dead area caused by fixed objects.
For example, using the estimated dead area information, the following measures may be taken to reduce the dead area. As a result, it is possible to reduce the avoidance operation of the dead area.
Specific examples of treatment are as follows. Change the installation position of the base station. Change the orientation, directivity and transmit power of the base station's antenna. Add more base stations. Install a reflector that reflects radio waves.
By reviewing the infrastructure side using the dead area estimation result in this way, the dead area can be reduced.
Dead areas caused by moving objects cannot be eliminated by infrastructure measures. However, by using the driving support device 200, it is possible to realize a more reliable driving support system in cooperation with the infrastructure.

The surveillance map may be a dynamap.
A dynamic map consists of static information, semi-static information, semi-dynamic information and dynamic information. Static information is a static high-precision three-dimensional map. Semi-static information, semi-dynamic information and dynamic information are information capable of identifying locations that change over time.
These information may be updated as follows. A dead area caused by a fixed object is made to correspond to static information or quasi-static information. A dead area caused by a moving object is made to correspond to quasi-dynamic information or synchronous information.

If the factor of the dead area is a moving object and the moving object is a vehicle, the vehicle that is the factor may be specified and the location information of the vehicle that is the factor may be used.

***Summary of Embodiments***
Even if there is a possibility that the mobile station moves through the dead area between the base station 300 and the mobile station (vehicle 500) in the transportation system, the embodiment predicts the dead area in advance and avoids the influence of the dead area. and improve the safety of automated driving.

The driving support device 200 monitors the quality of wireless communication between the base station 300 and the vehicle 500 and the location information of the vehicle 500, and measures in advance areas where communication quality may deteriorate.
The driving assistance device 200 calculates the coverage area of the base station 300 based on the transmission performance and radio wave propagation characteristics of the base station 300 .
Driving support device 200 calculates the coverage area of vehicle 500 based on the transmission performance and radio wave propagation characteristics of vehicle 500 .
The driving support device 200 determines the possibility of the vehicle 500 traveling in the dead area based on the coverage area of the base station 300, the coverage area of the vehicle 500, the current position of the vehicle 500, and the future travel route of the vehicle 500.
When there is a possibility that the vehicle 500 will travel through the dead area, the driving assistance device 200 notifies switching to communication with another base station 300 and switches to inter-vehicle communication before the vehicle 500 travels through the dead area. A notification of switching or information necessary for traveling in a dead area is delivered to the vehicle 500 in advance.
Thus, the driving assistance device 200 considers not only the coverage area of downlink communication from the base station 300 to the vehicle 500 but also the coverage area of uplink communication from the vehicle 500 to the base station 300 . Thereby, the dead area can be presumed for each vehicle 500 . Then, it is possible to estimate a dead area that cannot be estimated even if downlink communication from the base station 300 to the vehicle 500 is taken into account, and to avoid deterioration of communication quality in advance.

The driving support device 200 measures the communication quality deterioration area, calculates the coverage area of the base station 300, calculates the coverage area of the vehicle 500, and estimates the dead area.
In addition, the driving support device 200 estimates whether the factor of the dead area is a fixed object or a moving object. In addition, the driving support device 200 changes the estimation period of the dead area according to the factor of the dead area.

*** Supplement to the embodiment ***
The hardware configuration of the driving assistance device 200 will be described based on FIG. 13 .
The driving support device 200 has a processing circuit 209 .
The processing circuit 209 is hardware that implements the dead area monitoring unit 210 , the travel prediction unit 220 and the driving support unit 230 .
The processing circuitry 209 may be dedicated hardware, or may be the processor 201 that executes programs stored in the memory 202 .

If processing circuitry 209 is dedicated hardware, processing circuitry 209 may be, for example, a single circuit, multiple circuits, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof.
ASIC is an abbreviation for Application Specific Integrated Circuit.
FPGA is an abbreviation for Field Programmable Gate Array.

The driving assistance device 200 may include multiple processing circuits that substitute for the processing circuit 209 .

In the processing circuitry 209, some functions may be implemented in dedicated hardware and the remaining functions may be implemented in software or firmware.

In this way, the functions of the driving assistance device 200 can be realized by hardware, software, firmware, or a combination thereof.

Each embodiment is an example of a preferred form and is not intended to limit the technical scope of the present disclosure. Each embodiment may be implemented partially or in combination with other embodiments. The procedures described using flowcharts and the like may be changed as appropriate.

The “part” of each element of the driving support device 200 may be read as “processing”, “process”, “circuit” or “circuitry”.

100 driving support system, 200 driving support device, 201 processor, 202 memory, 203 storage, 204 communication device, 209 processing circuit, 210 dead area monitoring unit, 211 downlink monitoring unit, 212 base station area calculation unit, 213 uplink monitoring unit, 214 vehicle area calculation unit, 215 dead area estimation unit, 216 factor determination unit, 220 travel prediction unit, 230 driving support unit, 280 communication unit, 290 storage unit, 300 base station, 301 processor, 302 storage device, 303 communication device, 400 roadside device, 401 processor, 402 storage device, 403 communication device, 411 roadside camera, 412 radar sensor, 500 vehicle, 501 processor, 502 storage device, 503 communication device, 509 vehicle-mounted device, 511 vehicle-mounted camera, 512 radar sensor, 513 Positioning receiver, 514 vehicle speed sensor, 515 gyro sensor, 521 display, 522 speaker, 523 input device.

Claims (9)

a downlink monitoring unit that acquires from the vehicle downlink quality information indicating the quality of downlink communication from the base station to the vehicle;
a base station area calculation unit that calculates a coverage area in which the base station can communicate based on the downlink quality information;
an uplink monitoring unit that acquires from the base station uplink quality information indicating the quality of uplink communication from the vehicle to the base station;
a vehicle area calculation unit that calculates a coverage area in which the vehicle can communicate based on the upstream quality information and the transmission performance of the vehicle;
a dead area estimation unit for estimating a dead area where communication quality between the base station and the vehicle is degraded based on the coverage area of the base station and the coverage area of the vehicle;
a driving support unit that transmits to the vehicle treatment information indicating a treatment for the dead area;
A driving support device. The driving support device is
A travel prediction unit that predicts a travel route of the vehicle based on vehicle position information that indicates the position of the vehicle and is obtained from the vehicle and travel information that indicates the traveling direction of the vehicle and is obtained from the vehicle;
The travel prediction unit determines whether the vehicle travels in the dead area based on the predicted travel route,
The driving assistance device according to claim 1, wherein the driving assistance unit transmits the action information to the vehicle when it is determined that the vehicle travels in a dead area. The driving support device according to claim 1 or 2, wherein the driving support unit acquires roadside unit peripheral information indicating a situation around the roadside unit from the roadside unit, and transmits the roadside unit peripheral information to the vehicle. . 2. The base station area calculation unit and the vehicle area calculation unit calculate the coverage area based on communication quality required for realizing an application used in a driving support system including the driving support device. The driving assistance device according to any one of claims 3 to 4. The dead area estimation unit does not use the downlink quality information acquired before the past reference period and the uplink quality information acquired before the past reference period, and the downlink quality information acquired during the past reference period and the The driving assistance device according to any one of claims 1 to 4 , wherein the dead area is estimated using uplink quality information acquired during a past reference period. The driving support device is
a factor determination unit that determines a factor of the dead area based on a change in the position of the dead area and determines an estimation cycle of the dead area according to the factor;
The driving assistance device according to any one of claims 1 to 5 , wherein the dead area estimation unit estimates the dead area at the estimation period after the estimation period is determined. The action information includes information necessary for switching communication with the base station to communication with another base station or communication with the base station via vehicle-to-vehicle communication, and information necessary for driving in the dead area. Indicate at least one of the information and
The driving support device according to any one of claims 1 to 6 , wherein the driving support unit transmits the action information to the vehicle before the vehicle travels through the dead area. obtaining from the vehicle downlink quality information indicating the quality of downlink communication from the base station to the vehicle;
calculating a coverage area in which the base station can communicate based on the downlink quality information;
obtaining from the base station uplink quality information indicating the quality of uplink communication from the vehicle to the base station;
calculating a coverage area in which the vehicle can communicate based on the upstream quality information and the transmission performance of the vehicle;
estimating a dead area where communication quality between the base station and the vehicle is degraded based on the coverage area of the base station and the vehicle;
A driving support method for transmitting to the vehicle treatment information indicating a treatment for the dead area. a downlink monitoring process for acquiring from the vehicle downlink quality information indicating the quality of downlink communication from the base station to the vehicle;
a base station area calculation process for calculating a coverage area in which the base station can communicate based on the downlink quality information;
an uplink monitoring process of acquiring from the base station uplink quality information indicating the quality of uplink communication from the vehicle to the base station;
a vehicle area calculation process for calculating a coverage area in which the vehicle can communicate based on the upstream quality information and the transmission performance of the vehicle;
dead area estimation processing for estimating a dead area in which communication quality between the base station and the vehicle deteriorates based on the coverage area of the base station and the coverage area of the vehicle;
driving support processing for transmitting to the vehicle treatment information indicating a treatment for the dead area;
A driving support program for making a computer execute

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