WO2025182812A1 - Vehicle tracking system - Google Patents

Abstract

The present invention tracks the location of a stolen vehicle.　This vehicle tracking system comprises a server provided with: a reception unit that receives, using a plurality of reception devices, an identification ID that is transmitted by a transmission device, which is mounted on a stolen vehicle and transmits two types of radio waves having different communication ranges, and that receives, from the plurality of reception devices, location information of each reception device together with reception information of the identification ID using the two types of radio waves; and a vehicle location estimation unit that estimates the location of the vehicle by plotting the reception states of the two types of radio waves on a road map.

Description

Vehicle Tracking System

The present invention relates to vehicle tracking technology that utilizes wireless communication technology, and in particular to a vehicle tracking system that uses multiple terminals to receive the vehicle ID transmitted by two types of radio waves installed in the vehicle and with different reachable communication distances, and then plots the vehicle's location on a road map using a server device.

Vehicle theft has become a social problem, and technologies to prevent theft itself and to track vehicles after they have been stolen have been developed.
In recent years, stolen vehicle tracking technologies that utilize wireless communication technology have been developed. For example, Patent Document 1 discloses a technology that enables tracking of, for example, a stolen vehicle without using a mobile phone or PHS by notifying a vehicle tracking server of another vehicle ID obtained through vehicle-to-vehicle communication via, for example, a hotspot device.
However, the technology described in Patent Document 1 requires that each vehicle be equipped with a communication device for vehicle-to-vehicle communication, which makes it difficult to apply this technology to vehicles such as motorcycles, where it is difficult to install a wireless communication device for vehicle-to-vehicle communication due to price constraints and the like.

Patent No. 4015925

The technology described in Patent Document 1 requires that each vehicle be equipped with a communication device for vehicle-to-vehicle communication. Therefore, it is difficult to apply this technology to vehicles such as motorcycles, where it is difficult to install a wireless communication device due to price constraints, etc.

The present invention has been made in consideration of the above-mentioned problems, and provides a stolen vehicle tracking system including a server device that includes a receiving unit that receives, with a plurality of receiving devices, an identification ID transmitted from a transmitting device mounted on a vehicle and capable of transmitting the identification ID via two types of radio waves with different communication reachability, and receives from the plurality of receiving devices information on the identification ID received via the two types of radio waves along with position information of each receiving device, and a vehicle position estimating unit that estimates the position of the vehicle by plotting the reception status of the two types of radio waves on a road map.
This makes it possible to accurately track the location of a stolen vehicle, for example, simply by providing the vehicle with an inexpensive wireless tag as a transmitter in advance.

(1) A vehicle tracking system according to one aspect of the present invention (e.g., a "vehicle tracking system 1" described later) includes a transmitter (e.g., a "BLE tag 100" described later) mounted on a vehicle (e.g., a "vehicle 10" described later) that transmits identification ID information using two types of radio waves with different communication reach distances;
The system is configured with a server device (e.g., "server device 300" described later) that includes a plurality of receiving devices (e.g., "terminal 200" described later) that receive the identification ID from each of the two types of radio waves, a map unit (e.g., "map information storage unit 322" described later) that has a road map, a receiving unit (e.g., "log data receiving unit 311" described later) that receives reception information of the identification ID from the two types of radio waves along with position information of the receiving devices from the plurality of receiving devices, and a vehicle position estimation unit (e.g., "vehicle position estimation unit 312" described later) that estimates the position of the vehicle by plotting the reception status of the two types of radio waves on the road map.

According to (1) above, a transmitter that emits radio waves with two different communication ranges is installed in a vehicle, and the identification ID transmitted by the transmitter is received by multiple receivers, making it possible to estimate the vehicle's location.

(2) In the vehicle tracking system described in (1) above (e.g., the "Vehicle Tracking System 1" described below), the two types of radio waves may be characterized as a first radio wave having a first bit rate (e.g., the LR described below) and a second radio wave having a higher bit rate and a shorter communication range than the first radio wave (e.g., the 1MPHY described below).

According to (2) above, it is possible to accurately track a vehicle by simply equipping the vehicle with, for example, an inexpensive wireless tag.

(3) In the vehicle tracking system described in (1) above (for example, the "vehicle tracking system 1" described below), the vehicle position estimation unit may be configured to plot the reception status of the two types of radio waves on the road map by using map matching to estimate the most likely road.

According to (3) above, the position of the vehicle being tracked is always plotted on a road map, improving visibility and enabling accurate vehicle tracking.

(4) In the vehicle tracking system described in (1) to (3) above (e.g., the "vehicle tracking system 1" described below), the server device may further include performance information regarding the receivable ranges of the two types of radio waves for each model of receiving device as a performance information unit (e.g., the "performance information storage unit 323" described below), and the vehicle position estimation unit may estimate the position of the vehicle by plotting the reception status of the two types of radio waves on the road map based on the performance information.

According to (4) above, it is possible to track vehicles more accurately by taking into account the performance of the receiving device.

(5) In the vehicle tracking system described in (1) to (3) above (for example, the "vehicle tracking system 1" described below), the server device may further include area information in the map section regarding the receivable ranges of the two types of radio waves according to the area, and the vehicle position estimation section may estimate the position of the vehicle by plotting the reception status of the two types of radio waves on the road map based on the area information.

According to (5) above, it is possible to track vehicles more accurately by taking into account urban areas where radio waves have a narrow reach and suburban areas where they have a wide reach.

According to the present invention, vehicles such as motorcycles, which are difficult to equip with wireless communication devices due to cost constraints, can be accurately tracked, for example, in the event of theft, simply by equipping them with an inexpensive wireless tag.

1 is a diagram showing the basic configuration of an entire embodiment of the present invention. 10A and 10B are diagrams illustrating a state in which a receiving device receives radio waves with a short communication range in an embodiment of the present invention. FIG. 10 is a diagram showing a state in which a plurality of receiving devices receive radio waves with a long communication range in an embodiment of the present invention. FIG. 10 is a diagram showing a state in which a plurality of receiving devices receive radio waves from a stolen vehicle in chronological order in an embodiment of the present invention. FIG. 1 is a diagram showing the configuration of a transmitting device (BLE tag) according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of a receiving device (terminal) according to an embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of a server device according to an embodiment of the present invention. In the embodiment of the present invention, area information relating to a normal radio wave reception range and area information relating to a narrower than normal radio wave reception range are displayed on map information. 10 is a flowchart showing the operation of a receiving device when transmitting two types of radio waves with different reach distances from a BLE tag as a transmitting device to a terminal as a receiving device in an embodiment of the present invention. 10 is a flowchart showing the operation of the server device when position information on a tracked vehicle such as a stolen vehicle is transmitted from a terminal as a receiving device according to an embodiment of the present invention to the server device. 5 is a flowchart showing an operation of a server device according to an embodiment of the present invention when estimating the position of a tracked vehicle such as a stolen vehicle.

Next, an embodiment of the present invention will be described in detail with reference to the drawings.
<Embodiment 1>

Referring to FIG. 1, in this embodiment, the vehicle tracking system 1 includes n transmitting devices 100, m receiving devices 200, a server device 300, a user terminal 400, and a network 500. Note that n and m are any natural numbers.

In this embodiment, a Bluetooth (registered trademark) 5.0 or higher BLE tag is exemplified as the transmitting device 100 that is mounted on the vehicle 10 and transmits identification ID information using two types of radio waves with different communication reach distances. Hereinafter, in the description of this embodiment, the transmitting device 100 is also referred to as the BLE tag 100.
BLE is an abbreviation for Bluetooth (registered trademark) Low Energy, and operates for a long period of time, such as several years, using power supplied by a coin-type lithium battery, for example.
BLE has three types of PHYs (physical layers): a normal type 1MPHY, a high-speed type 2MPHY, and a long-range type Coded PHY.
The communication reach distance increases in the order of 2MPHY < 1MPHY < CodedPHY.
Hereinafter, Coded PHY will also be referred to as "Long Range" or abbreviated as "LR."

In this embodiment, the two types of radio waves are exemplified as LR, which has a data rate of 125 kbps and a long communication range, and 1MPHY, which has a data rate of 1 Mbps and a short communication range, but the present invention is not limited to this. For example, 2MPHY, which has a data rate of 2 Mbps, may be used instead of 1MPHY.
As will be described later, the BLE tag 100 switches between two types of radio waves (LR and 1MPHY) at a preset switching cycle, and broadcasts an "advertisement packet" including an identification ID of the BLE tag 100. For example, if the switching cycle is set to one second, the two types of radio waves are switched every second, and the advertisement packet is broadcast.
Note that, since the BLE tag is mounted on the vehicle 10, the identification ID can be used as a vehicle ID. Therefore, in the following description of this embodiment, the identification ID of the BLE tag 100 mounted on the vehicle 10 will also be referred to as a "vehicle ID."

The receiving device 200 supports, for example, Bluetooth (registered trademark) 5.0 (i.e., supports 1MPHY and LR), and is equipped with a GPS unit that acquires location information of the receiving device 200 and enables each receiving device 200 to acquire synchronized time information. Furthermore, as described below, the receiving device 200 has a terminal function that responds to requests from the server device 300. For example, a mobile terminal such as a smartphone can be used as the receiving device 200.
The receiving device 200 is not limited to a mobile terminal such as a smartphone. For example, any terminal device may be used as long as it supports Bluetooth (registered trademark) 5.0 (i.e., supports 1MPHY and LR), is equipped with a GPS, acquires location information for the receiving device 200, and allows each receiving device 200 to acquire synchronized time information. A communication device mounted on the vehicle 10 may also be used. Such a receiving device 200 may also be installed at a predetermined location, such as a house or a telephone pole.
Hereinafter, a terminal will be exemplified as the receiving device 200 of this embodiment. In the following description of this embodiment, the receiving device 200 will also be referred to as the "terminal 200."

When the terminal 200 receives an advertising packet including the identification ID (vehicle ID) of the BLE tag 100 from the BLE tag 100, the terminal 200 can store the time information when the advertising packet was received and the location information of the terminal 200 when the packet was received in the memory unit 220 (log data memory unit 221 by identification ID) of the terminal 200.
In this way, when the terminal 200 receives the advertising packet, it can determine that the BLE tag 100 that sent the advertising packet (i.e., the vehicle 10 equipped with the BLE tag 100) is located within a communication reach distance from the position of the terminal 200 at that time according to the type of radio waves received.

Note that the communication range depends on the performance of the terminal 200, the radio wave environment, etc. For this reason, in this embodiment, as described below, performance information regarding the receivable range of two types of radio waves (1MPHY and LR) may be set in advance in the server device 300 for each model of terminal 200. Furthermore, taking into account areas with poor radio wave environments where the radio wave communication range is narrow (e.g., urban areas) and areas with good radio wave environments where the radio wave communication range is wide (e.g., suburbs), area information regarding the radio wave environment may be set on a map in the server device 300.

In order for the user's terminal 200 to be used as a receiving device, it is necessary to install in advance a program for receiving the identification ID broadcast from the BLE tag 100 mounted on the vehicle 10 and a program for responding to requests for log data by identification ID from the server device 300 (described later), and to keep the terminal 200 in a state where it can receive data at all times. By doing so, when the terminal 200 is located within the communication reach of the packets broadcast from the BLE tag 100, it can receive advertising packets containing the vehicle ID (the identification ID of the BLE tag 100) from the BLE tag 100 periodically (e.g., every second) via one or both of two types of radio waves (LR and 1MPHY). It can also respond to requests from the server device 300. For this reason, the terminal 200 owned by a user who uses the vehicle tracking system 1 (i.e., who owns the vehicle 10) may also be used as a receiving device.

The server device 300 is a server device that, for example, manages operations related to the stolen vehicle search process. For this reason, the server device 300 may acquire from each terminal 200 the identification ID (vehicle ID) of the BLE tag 100 received by that terminal 200, the time information when the advertising packet was received, and the location information of that terminal 200 when the packet was received, and manage this as log information for each identification ID (vehicle ID) in an identification ID-specific log data storage unit 321 included in the storage unit 320.

In response to a request from the user terminal 400, the server device 300 starts a search process for, for example, the location information of a stolen vehicle. Specifically, based on the vehicle ID designated by the user terminal 400 as the stolen vehicle, the server device 300 refers to the log information for each vehicle ID described above to acquire information related to the vehicle ID received by the terminal 200 (such as the time of reception, the location information of the terminal 200, and the type of radio waves received). The server device 300 can then estimate the location of the stolen vehicle by plotting the reception status of the radio waves as viewed from the location of the terminal 200 on a road map. The server device 300 may then transmit the estimated information to the user terminal 400.
In this way, one of the features of the present invention is that broadcast transmission is performed by switching between radio waves with a long communication range and radio waves with a short communication range at short intervals.

FIG. 2A is a diagram showing the transmission and reception state of radio waves, in which the area in which the terminal 200 can receive advertising packets from the BLE tag 100 is indicated by a solid line, and the area in which the BLE tag 100 can transmit advertising packets is indicated by a dashed line.
As shown in Figure 2A, if the terminal 200 receives radio waves (e.g., 1MPHY) with a short communication range, it can determine that the location of the vehicle equipped with the BLE tag 100 is located on a road near the terminal 200.

On the other hand, even if none of the terminals 200 is receiving radio waves with a short communication range, it can be estimated that there is a high probability that multiple terminals 200 are receiving radio waves (e.g., LR) with a long communication range.
FIG. 2B is a diagram showing the transmission and reception state of radio waves, in which the area in which each terminal 200 can receive advertising packets from the BLE tag 100 is indicated by a solid line, and the area in which the BLE tag 100 can transmit advertising packets is indicated by a dashed line.
2B , it can be determined that the vehicle equipped with the BLE tag 100 is located on a road located in an overlapping area (common area) that is the intersection of circular areas with a center at the position of each terminal 200 and a radius equal to the communication reachability distance of packets broadcast from the BLE tag 100. Note that, for a terminal 200 that has not received packets broadcast from the BLE tag 100, if there is an area (referred to as a "deletion area") in which a circular area with a center at the position of the terminal 200 and a radius equal to the communication reachability distance of packets broadcast from the BLE tag 100 overlaps the overlapping area, the area obtained by deleting the deletion area from the overlapping area may be determined to be the overlapping area in which the BLE tag 100 is located.
In this way, the BLE tag 100 broadcasts radio waves with a long communication range and radio waves with a short communication range at short intervals, switching between them, so that the server device 300 can estimate the location of a stolen vehicle, for example, with a fairly high probability.

Furthermore, if another terminal 200 receives an advertising packet from the stolen vehicle before the time at which terminal 200 receives the advertising packet from the stolen vehicle, it can be assumed that the stolen vehicle has moved from the location of the stolen vehicle at which another terminal 200 received the packet before that time to the location of the stolen vehicle at which terminal 200 received the advertising packet from the stolen vehicle. Similarly, if another terminal 200 receives an advertising packet from the stolen vehicle after the time at which terminal 200 receives the advertising packet from the stolen vehicle, it can be assumed that the stolen vehicle has moved from the location of the stolen vehicle at which terminal 200 received the advertising packet from the stolen vehicle to the location of the stolen vehicle at which another terminal 200 received the packet after that time.

2C shows four terminals 200 receiving advertising packets from a stolen vehicle in the order of time series T1<T2<T3<T4. Here, the inner circle of two solid-line circles centered on terminal 200 indicates the range of reach within which terminal 200 can receive 1 MPHY packets, and the outer circle indicates the range of reach within which terminal 200 can receive LR packets. Also, the inner circle of two dashed-line circles centered on BLE tag 100 indicates the range of reach within which the BLE tag can transmit 1 MPHY packets, and the outer circle indicates the range of reach within which terminal 200 can transmit LR packets.
Figure 2C shows a timeline of a stolen vehicle entering a range where each terminal 200 can receive LR packets, then entering a range where 1MPHY packets can be received, and then passing through a range where LR packets can be received before exiting an area where LR packets cannot be received.
In this way, by plotting the reception status of two types of radio waves from the stolen vehicle in chronological order on a road map for each terminal 200 that receives an advertising packet from the stolen vehicle, map matching can be used to accurately track when and on which road the stolen vehicle is located.
In addition, in FIG. 2C, a display form in which server device 300 plots the location of the stolen vehicle based on the reception status as seen from the location of terminal 200 has been described.
In response to this, the server device 300 may display on a road map the reception status (the range of transmission distance within which an MPHY packet centered on the stolen vehicle can be transmitted and the range of transmission distance within which an LR packet centered on the stolen vehicle can be transmitted) as viewed from the position of the stolen vehicle 10 broadcasting the advertising packet. In either case, the display method described above always plots the position of the stolen vehicle on a road map, improving visibility and enabling accurate vehicle tracking.
In addition, in Figures 2A, 2B, 2C, etc., if there are multiple different roads in the overlapping area where the stolen vehicle (BLE tag 100) is suspected to be located, the road on which each terminal 200 is located, a road without buildings or the like that would cause radio wave interference between the location of each terminal 200, or a road that is continuously connected to the road identified before and after the time in question may be determined to be the most likely road on which the vehicle is located.

User terminal 400 is a terminal operated by a user who, for example, is attempting to search for a stolen vehicle. Hereinafter, such a user attempting to search for a stolen vehicle will be referred to as a "search request user." Note that if the user owns terminal 200 as a receiving device, the user may use terminal 200 as user terminal 400.

The search requesting user operates the user terminal 400 to send a request to the server device 300 to start a search process for stolen vehicle location information. In doing so, as described above, the server device 300 obtains time series information related to the vehicle ID (such as the time of reception, the location information of the terminal 200, and the type of radio waves received) based on the log information for each vehicle ID received from each terminal 200, estimates the location of the stolen vehicle by plotting the reception status of the two types of radio waves on a road map, and outputs the estimated information by plotting it on the screen of the user terminal 400, for example. In this way, the search requesting user can refer to this display to know the location of the stolen vehicle at that time.

As described above, in this embodiment, each device works together to perform the search process, making it possible for the search requesting user to search for the location information of a stolen vehicle selected as the search target.

The connection of these devices will now be described. Each terminal 200 communicates with each BLE tag 100 in accordance with BLE (Bluetooth (registered trademark) Low Energy). Each terminal 200 is connected to a network 500 using, for example, LTE (Long Term Evolution), 4G (4th Generation), or 5G (5th Generation), and communicates with the server device 300 via the network 500.
The network 500 is realized by combining, for example, a mobile phone network, the Internet, an intranet, or the like.

The server device 300 communicates with each terminal 200 via the network 500. The server device 300 also communicates with the user terminal 400. The server device 300 and the user terminal 400 may be connected, for example, by a local area network (LAN) or an intranet. As described above, if a user has a terminal 200 as a receiving device, the user may use the terminal 200 as the user terminal.
The outline and configuration of the vehicle tracking system 1 according to this embodiment have been described above.
Next, the functions of these devices will be explained.

First, referring to Figure 3, we will explain the functional blocks included in the BLE tag 100 as a transmitting device. As shown in Figure 3, the BLE tag 100 includes a control unit 110, an identification ID management unit 120, a BLE communication unit 130, and a battery unit 150.

The battery unit 150 is a battery that supplies power to the control unit 110, the identification ID management unit 120, and the BLE communication unit 130. The BLE tag 100 is powered by the power supplied by this battery unit 150, and is therefore a so-called active tag. The battery unit 150 is realized by, for example, a coin-type lithium battery. The BLE tag 100 can operate for a long period of time, such as several years, on the power supplied by the battery unit 150, although this varies depending on the packet transmission period of the BLE communication unit 130. Note that a battery installed in the vehicle 10 may also be used as the battery unit 150.

The identification ID management unit 120 manages the identification ID (vehicle ID), which is an identifier for identifying the vehicle 10 equipped with the BLE tag 100 described above.

The BLE communication unit 130 is a communication unit for performing communication in accordance with BLE. The BLE communication unit 230 also includes an antenna. As will be described later, the BLE communication unit 130 broadcasts two types of radio waves (LR and 1MPHY) with different communication reach distances, switching between them at predetermined intervals for each interval, under switching control of the control unit 110. In this embodiment, the interval is set to 1 second, but is not limited to this.

The control unit 110 switches between two types of radio waves (LR and 1MPHY) based on a preset cycle, for example, every second, and broadcasts an "advertising packet" including an identification ID (vehicle ID) via the BLE communication unit 130. Specifically, the "advertising packet" is broadcast every second using 1MPHY or LR. By doing so, as shown in FIG. 3 , the terminal 200 can receive advertising packets from BLE tags 100 located within the two communication reachable ranges (short distance and long distance) of the terminal 200 every second. As a result, the terminal 200 can identify the vehicle ID of the packet sender based on the received advertising packet, and can also identify the distance range within which the vehicle 10 is located from the terminal 200.
The vehicle 10 of the present invention is assumed to be a vehicle (e.g., a two-wheeled vehicle) with an average speed of approximately 20 km/h. Therefore, even if a stolen vehicle is traveling, the distance the vehicle 10 moves per second is approximately 5.5 m, which is considered to be within the margin of error when locating the stolen vehicle. In this way, the margin of error may be set based on, for example, the upper limit or average moving speed of the vehicle 10.
Next, functional blocks included in the terminal 200 will be described with reference to FIG.

As shown in FIG. 4, the terminal 200 includes a control unit 210, a storage unit 220, and a communication unit 230.

The control unit 210 is composed of a processing unit such as a microprocessor, and controls each component of the terminal 200. Details of the control unit 210 will be described later.

The memory unit 220 is composed of semiconductor memory, etc., and stores various programs such as control programs called firmware or operating systems, and programs for causing the control unit 210 to function as a time/location information acquisition function, an identification ID information reception function, an identification ID-specific log data transmission function, etc., as well as other data (also referred to as ``log data by identification ID'') that links the identification ID information, etc. contained in the advertising packets received from each BLE tag 100 to the identification ID information, the type of radio wave (LR or 1MPHY) that received the identification ID information, the time information when the advertising packet containing the identification information was received, and the location information of the terminal 200 when the advertising packet was received.
For this reason, the memory unit 220 includes, in addition to the program, a log data memory unit 221 for storing log data for each identification ID as chronological information, which is created based on the identification ID information contained in the advertising packet received from each BLE tag 100.
The storage unit 220 has been described above.

The communication unit 230 has a DSP and the like, and is equipped with a network communication unit 231 that communicates with the server device 300 and the like via the network 500 in accordance with standards such as LTE (Long Term Evolution), 4G (4th Generation), 5G (5th Generation), and Wi-Fi (registered trademark), and a BLE communication unit 232 for receiving advertising packets transmitted from each BLE tag 100. The network 500 is realized by a network such as the Internet or a mobile phone network, or a network that combines these. Furthermore, a LAN (Local Area Network) may be included as part of the network.

Next, the control unit 210 will be described in detail. The control unit 210 is composed of a microprocessor having a CPU, RAM, ROM, I/O, etc. The CPU executes each program read from the ROM or storage unit 220, and during execution reads information from RAM, ROM, and storage unit 220, writes information to RAM and storage unit 220, and sends and receives signals to and from the communication unit 230. In this way, the processing in this embodiment is realized by the cooperation of hardware and software (programs).

The control unit 210 has the following functional blocks: a time/location information acquisition unit 211, an ID information reception unit 212, and an ID-specific log data transmission unit 213.

When the ID information receiving unit 212 (described later) receives ID identification information of a given BLE tag 100 via an advertising packet, the time/location information acquisition unit 211 acquires the time at which the advertising packet was received and the location information of the terminal 200 at the time of reception. Here, the time may be acquired from time information provided by the terminal 200, and the location information may be current location information (GPS information) provided by the terminal 200.

When the identification ID information receiving unit 212 receives either or both of the advertisement packets transmitted by switching between two types of radio waves (LR and 1MPHY) periodically (for example, every second) from a BLE tag 100 located within the communication reach of the terminal 200, the identification ID information receiving unit 212 creates a single record (referred to as "log data by identification ID") linked to the identification ID, including the type of radio waves (either LR or 1MPHY or both) at the time the packet was received, the identification ID information received by the advertisement packet, the time information when the advertisement packet was received, and the location information of the terminal 200 at the time the advertisement packet was received, and stores this in the identification ID-specific log data storage unit 221 as described above.
As a result, by referring to the log data for each identification ID, it is possible to determine that the terminal 200 was located within a communication reachable distance corresponding to the type of radio wave from the position of the vehicle 10 identified by the identification ID (vehicle ID) at the time indicated by the time information included in the log data for each identification ID. When receiving signals via 1MPHY as described above, it is possible to determine that the terminal 200 was located within a short distance range (referred to as a "short distance area") from the vehicle 10.
Furthermore, if there is another terminal 200 that receives the same identification ID at the same time, it can be determined that the other terminal 200 is located within the communication reach range ("long distance area") corresponding to the type of radio wave from the vehicle 10 identified by the identification ID (vehicle ID).
In this case, when the position of the vehicle 10 is viewed from the positions of the terminal 200 and another terminal 200, it can be estimated that the vehicle 10 was located in a common area consisting of a short-distance area centered on the position of the terminal 200 and a long-distance area centered on the position of the other terminal 200. In this way, if multiple terminals 200 receive packets including the vehicle ID at the same time, the area including the position of the vehicle 10 can be estimated quite accurately. Note that although the same time is used here, as described above, even if there is a slight time difference, it can be treated as an error range. As described above, the error range may be set based on, for example, the upper limit or average moving speed of the vehicle 10.
Details will be given later in the explanation of the server device 300, but by further performing map matching with road maps and building location information, etc., it becomes possible to determine with a high degree of accuracy (assuming a range of error is allowed) where on which road the vehicle was located, or where it is currently located.

When the ID-specific log data transmission unit 213 receives a request for ID-specific log data linked to a specified ID from the server device 300 (described later), it transmits the terminal ID and the ID-specific log data linked to the ID to the server device 300. Specifically, for example, when a time range is specified by the server device 300, the ID-specific log data transmission unit 213 may transmit a set of ID-specific log data linked to the ID, whose time information belongs to the specified time range. This enables the server device 300 to estimate where the vehicle 10 was located during the time range, as described later.
When the ID of the vehicle 1 to be tracked is specified in advance by the server device 300, the ID-specific log data transmitting unit 213 may immediately transmit the ID-specific log data associated with the ID created by the ID information receiving unit 212 to the server device 300. This makes it possible to estimate the current location of the vehicle.
Next, functional blocks included in the server device 300 will be described with reference to FIG.

As shown in FIG. 5, the server device 300 includes a control unit 310, a storage unit 320, and a communication unit 330.

The control unit 310 is composed of a processing unit such as a microprocessor, and controls the various components that make up the server device 300. Details of the control unit 310 will be described later.

The storage unit 320 is composed of, for example, a hard disk, semiconductor memory, etc., and stores various programs such as control programs called firmware and operating systems, and programs that cause the control unit 310 to function as an ID-specific log data receiving function, a vehicle position estimation function, etc., and also includes an ID-specific log data storage unit 321, a map information storage unit 322, and a performance information storage unit 323.

The identification ID-specific log data storage unit 321 stores a collection of identification ID-specific log data received from each terminal 200 by the identification ID-specific log data receiving unit 311, as described below. Here, the collection of identification ID-specific log data is a collection of records that includes, for each vehicle ID (the identification ID of the BLE tag mounted on the vehicle), the time information when the terminal 200 received an advertising packet containing the vehicle ID, the terminal ID of the terminal 200 that received the advertising packet, the location information of the terminal 200 at the time of receiving the advertising packet, and the type of radio wave (LR or 1MPHY) at the time of receiving the advertising packet. Note that the collection of identification ID-specific log data is time-series information based on the time information.

The map information storage unit 322 includes information on features such as roads and facilities, road information, facility location information, parking lot information, and other information. Road information stores so-called road map information such as road types and traffic lights. Facility information stores location information for each general facility as latitude and longitude information. Parking lot information stores location information for parking lots as latitude and longitude information. The map information storage unit 322 may also include display map data for displaying backgrounds for roads, road maps, etc.

The map information storage unit 322 may further include a receivable range area information unit 3221. Taking into account that, for example, urban areas have a narrower radio wave coverage area (shorter reach distance) than normal, while suburban areas have a wider reach, the receivable range may include area information relating to two types of radio wave coverage. Figure 6 shows an area relating to a normal receivable range (normal range area) and area information relating to a narrower receivable range than normal (narrow range area). Here, the normal range area shows, for example, a reach distance of 150 m when receiving LR and 90 m when receiving 1 M, while the narrow range area shows, for example, a reach distance of 70 m when receiving LR and 50 m when receiving 1 M. Receivable range area information may also be obtained by measuring the reach distance on-site.

Since the reach of the two types of radio waves differs depending on the model of terminal 200, the performance information storage unit 323 stores information that has been pre-set to indicate the receivable range (reach) of the two types of radio waves, for example, corresponding to model information (information that identifies the model of terminal 200) linked to the terminal ID of terminal 200.
In this case, the reachable distance information of the two types of radio waves may be stored for each model. For example, the receivable range area information may be set by measuring the reachable distance on-site. Note that it is expected that the reachable distance of the two types of radio waves from the same BLE tag 100 will differ depending on the area where the terminal 200 is located and that the reachable distance of the two types of radio waves from the same BLE tag 100 will also differ depending on the model of the terminal 200. Therefore, the reachable distance range may be set according to the model and area for each model of the main terminal 200 in each area by measuring the reachable distance on-site for each model of the terminal 200.
The storage unit 320 has been described above.

The communication unit 330 has a DSP and the like, and communicates with the terminal 200 and the like via the network 500 in accordance with standards such as LTE (Long Term Evolution), 4G (4th Generation), 5G (5th Generation), and Wi-Fi (registered trademark). The network 500 is realized by a network such as the Internet or a mobile phone network, or a network that combines these. A LAN (Local Area Network) may also be included as part of the network.

Next, the control unit 310 will be described in detail. The control unit 310 is composed of a microprocessor having a CPU, RAM, ROM, I/O, etc. The CPU executes each program read from the ROM or storage unit 320, and during execution reads information from the RAM, ROM, and storage unit 320, writes information to the RAM and storage unit 320, and sends and receives signals to and from the communication unit 330. In this way, the processing in this embodiment is realized by the hardware and software (programs) working together.

The control unit 310 has the following functional blocks: an ID-specific log data receiving unit 311 and a vehicle position estimating unit 312.

When a user requests location information of a tracked vehicle, such as a stolen vehicle, with a specified vehicle ID (the identification ID of the BLE tag installed on the vehicle) via the user terminal 400, the identification ID-specific log data receiving unit 311 specifies, for example, a time range and requests each terminal 200 to transmit identification ID-specific log data associated with the vehicle ID of the tracked vehicle received within that time range. This allows the identification ID-specific log data receiving unit 311 to receive, as time-series data, the identification ID-specific log data associated with the vehicle ID of the tracked vehicle received within that time range from each terminal 200. Furthermore, from this point onward, the server device 300 may request each terminal 200 to transmit the identification ID-specific log data associated with the vehicle ID of the tracked vehicle to the server device 300 in real time when the server device 300 receives the identification ID-specific log data. This allows the server device 300 to acquire the radio wave reception status from the tracked vehicle in real time.
Since the server device 300 cannot acquire the reception status of radio waves from vehicles that are not stolen, the location information of vehicles that are not stolen is protected.
The identification ID-specific log data receiving unit 311 generates a set of identification ID-specific log data based on the identification ID-specific log data linked to the vehicle ID of the tracked vehicle received from each terminal 200, including the time information when each terminal 200 received the advertising packet including the vehicle ID, the location information of the terminal 200 at the time the advertising packet was received, and the type of radio wave (LR or 1MPHY) at the time the advertising packet was received, and stores this in the identification ID-specific log data storage unit 321.
The ID-specific log data receiving unit 311 stores a set of ID-specific log data in the order of time information as time-series information.
When terminal 200 receives a 1MPHY advertising packet, it is clear that the vehicle is located within a short-distance reach from the location of terminal 200, and that the vehicle is located within a long-distance reach from the location of terminal 200. However, if, as time passes, the vehicle leaves the short-distance communication reach from the terminal and is located only within a long-distance reach from the terminal, it is desirable to also store the reception status of the LR signal in the log data by identification ID, as this is necessary to determine the time when the vehicle leaves the short-distance communication reach from the terminal.

2C , the vehicle position estimation unit 312 determines, based on position information of each terminal 200 that has received packets broadcast from the tracked vehicle (equipped with the BLE tag 100) within the specified time range, that the tracked vehicle is located on a road located in an overlapping area (common area) that is the intersection of circular areas having a center at the position of each terminal 200 and a radius equal to the communication reachable distance of the packets broadcast from the tracked vehicle (equipped with the BLE tag 100), and by plotting the overlapping area (common area) in time series on a road map, the road on which the tracked vehicle is located can be identified. As mentioned above, if there is a terminal 200 located within a communication reach distance from the overlapping area (common area) that can receive the packet, but that has not received the packet broadcast from the tracked vehicle (equipped with the BLE tag 100), the area obtained by deleting the deletion area calculated based on the position of the terminal 200 from the overlapping area may be determined to be the overlapping area in which the tracked vehicle (equipped with the BLE tag 100) is located.
The location information of the vehicle at a certain time may be plotted on a road map based on a plurality of pieces of log data within a range of several seconds before and after the time (in seconds). By doing so, the road on which the tracked vehicle (equipped with the BLE tag 100) is traveling and its location on the road can be identified.
In this way, the location of the vehicle can be estimated by mounting the BLE tag 100 that emits radio waves with two different communication reach distances on the vehicle 10 and receiving the identification ID emitted by the BLE tag 100 with multiple terminals 200. Furthermore, the location of the vehicle to be tracked is always plotted on a road map, which improves visibility and allows the vehicle's location to be tracked accurately.

As described above, the vehicle position estimation unit 312 may refer to the receivable range area information unit 3221 and, based on area information regarding the receivable ranges of two types of radio waves, plot the reachable range of the radio waves from the position information on a road map on the map information, thereby taking into account the effect of the radio wave environment in the area on the communication reach distance.
This makes it possible to track the vehicle's position more accurately by taking into account urban areas where radio waves have a narrow reach and suburban areas where they have a wide reach.

Similarly, as mentioned above, the vehicle position estimation unit 312 may refer to the performance information storage unit 323 and, based on performance information regarding the receivable range of the two types of radio waves for the model of terminal 200, plot the reception status of the two types of radio waves on the road map, thereby taking into account the differences in communication reach distance depending on the model.
This makes it possible to track the vehicle position more accurately, taking into account the performance of the terminal 200.
Next, the operation of this embodiment will be described with reference to the flowcharts shown in FIGS.

Figure 7 is a flowchart showing the operation of each terminal 200 as a receiving device when it receives two types of advertising packets that are switched every second from each BLE tag 100 as a transmitting device. In other words, unless the terminal 200 is stopped, each terminal 200 is in a state where it can receive advertising packets from each BLE 100 in parallel, and performs the operation shown below.

Referring to Figure 7, in step S10, each terminal 200 checks whether it has received an advertising packet broadcast by switching between two types of radio waves (LR and 1MPHY) every preset switching period (e.g., 1 second).

If the terminal 200 receives any advertising packet in step S11, it proceeds to step S12. If it has not received any advertising packet, it proceeds to step S10.

In step S12, the terminal 200 acquires the time information when the advertising packet was received and the location information of the terminal 200 when the advertising packet was received.

In step S13, log data by identification ID is created as time-series information, linking the identification ID information received in the advertising packet, the radio wave type of the advertising packet, the time information when the advertising packet was received, and the location information of the terminal 200 when the advertising packet was received to the vehicle ID (the identification ID of the BLE tag installed in the vehicle).

In step S14, the terminal 200 stores the created log information in the storage unit 220 (ID-specific log data storage unit 221). Then, the process proceeds to step S10.

By operating in this manner, each terminal 200 can record log information (log data by identification ID) for the BLE tag 100 when the BLE tag 100 is located within a communication range where it can receive advertising packets from the BLE tag 100 using at least one of the two types of radio waves (LR and 1MPHY).

Figure 8 is a flowchart showing the operation of the server device 300, when a user requests location information for a tracked vehicle, such as a stolen vehicle, via the user terminal 400, to acquire from each terminal 200 the radio wave reception status from the stolen vehicle stored in that terminal 200.

Referring to FIG. 8, in step S20, the server device 300 determines whether location information about a tracked vehicle, such as a stolen vehicle, has been requested. If so, the process proceeds to step S21. If not, the process proceeds to step S20.

In step S21, the server device 300 specifies a time range and requests each terminal 200 to provide log data by identification ID that is linked to the vehicle ID of the tracked vehicle (the identification ID of the BLE tag installed on the vehicle) received during that time range.

In step S22, the server device 300 acquires log data by identification ID linked to the vehicle ID of the tracked vehicle from each terminal 200.

In step S23, the server device 300 generates a time-series set of log data by identification ID, including the location information of the terminal 200 at the time the advertising packet containing the vehicle ID was received within the specified time range, and the type of radio wave (LR or 1MPHY) at the time the advertising packet was received, based on the time information received by each terminal 200. The process then proceeds to step S30.

Figure 9 is a flowchart showing the operation of the server device 300, which acquires from each terminal 200 the radio wave reception status from the stolen vehicle stored in that terminal 200 as described above, and plots the radio wave reception status from the stolen vehicle in chronological order on a road map based on the generated time series collection of log data by identification ID, thereby estimating the location of the stolen vehicle within a specified time range.

In step S30, the server device 300 extracts each terminal 200 that received radio waves from the stolen vehicle at the same time from the collection of log data by identification ID, and plots the radio wave coverage area centered on the position of that terminal 200 on a road map.

In step S31, the server device 300 plots on a road map the overlapping area of the radio wave coverage areas centered on the position of each terminal 200. As mentioned above, if there is a terminal 200 that is located within communication coverage distance from the overlapping area and can receive the packet, but that has not received the packet broadcast from the tracked vehicle, the overlapping area may be plotted on the road map by subtracting the deletion area calculated based on the position of that terminal 200.

In step S32, the server device 300 identifies roads that match the overlapping area plotted on the road map.

If one road is identified in step S33, the server device 300 proceeds to step S35. If two or more roads are identified, the server device 300 proceeds to step S34.

In step S34, the server device 300 identifies the most likely road on which the stolen vehicle is located, such as the road on which the terminal 200 is located, a road with no buildings or other obstacles between the terminal 200 and its location, or a road that is continuously connected to the road identified before and after that time, and then identifies the location of the stolen vehicle on that road, and proceeds to step S35.

In step S35, if there is one matched road, the server device 300 displays that road on the road map as the road where the stolen vehicle is located; if there are multiple matched roads, the server device 300 displays the most likely road as the road where the stolen vehicle is located, and also displays the vehicle's location on the road.

In step S36, if the server device 300 is still requested to locate the stolen vehicle, it proceeds to step S21. If it has decided to end the process of locating the stolen vehicle, it proceeds to step S20.

The above describes the operation of the vehicle tracking system 1, which enables the vehicle's position to be estimated by receiving, at multiple terminals 200 (receiving devices), an advertising packet containing the identification ID of a BLE tag 100 (transmitting device) mounted on the vehicle 10 and emitting radio waves with two different communication reach distances.

Each device can be realized by hardware, software, or a combination of these. Furthermore, the navigation method performed by the devices included in the above navigation system working together can also be realized by hardware, software, or a combination of these. Here, "realized by software" means that it is realized by a computer loading and executing a program.

The program can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R/Ws, semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, RAMs (random access memory)), SSDs (Solid State Drives), etc. The program may also be supplied to a computer by various types of transitory computer-readable media. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire or optical fiber, or via a wireless communication path.

The above-described embodiment is a preferred embodiment of the present invention, but the scope of the present invention is not limited to the above-described embodiment alone, and various modifications can be made without departing from the spirit of the present invention.

<Modification 1>
In the above-described embodiment, each terminal 200 creates log data by identification ID based on advertising packets received from the BLE tag 100. However, this is not limiting. Each terminal 200 may not create log data by identification ID for advertising packets received from BLE tags 100 other than the stolen vehicle designated by the server device 300, but may create log data by identification ID only for the BLE tag 100 of the designated stolen vehicle.
By doing so, each terminal 200 can reduce the load on the control unit 210 and the capacity of the storage unit 220. Furthermore, the server device 300 can identify the road and the location on the road on which the vehicle has been stolen since it was stolen.

<Modification 2>
In the above embodiment, the location of a stolen vehicle is tracked, but the present invention is not limited to this. The present invention can be used to track the location information of vehicles 10 related to a user (e.g., vehicles 10 used by the user's family, etc.). Furthermore, the present invention can be used by an operating authority to track the location information of vehicles 10 involved in a crime (e.g., vehicles used or used by a criminal).

<Modification 3> Displaying the location of a stolen vehicle in real time In the above-described embodiment, the location of a stolen vehicle at a specified time is tracked, but this is not limiting. For example, the location of a stolen vehicle may be tracked in real time.
In this case, for example, the server device 300 may request each terminal 200 to provide log data by identification ID linked to the vehicle ID of the tracked vehicle (the identification ID of the BLE tag installed in the vehicle) that will be received after the current time, and may also request each terminal 200 to send log data by identification ID linked to the vehicle ID of the tracked vehicle each time it creates such log data in the future.
In this way, the server device 300 can update the set of log data by identification ID based on the log data by identification ID linked to the vehicle ID of the tracked vehicle received in real time from each terminal 200. As a result, the server device 300 can estimate the current location of the stolen vehicle, for example, by plotting the reception status of radio waves from the stolen vehicle on a road map in real time.

<Modification 4> Displaying location information of tracked vehicles such as stolen vehicles in chronological order In the above-described embodiment, the location of a stolen vehicle at a specified time is tracked, but this is not limited to this. For example, the location of a stolen vehicle may be displayed and tracked in chronological order.
In this case, for example, the server device 300 can estimate the current location of the stolen vehicle for each time indicated by each time series by processing a set of ID-specific log data generated by acquiring ID-specific log data from each terminal 200 as time series data, thereby making it possible to display the location of the stolen vehicle in chronological order.

<Modification 5>
In the above embodiment, the server device 300 is implemented by a single server device, but the functions of the server device 300 may be distributed among a plurality of server devices as appropriate to form a distributed processing system.
Furthermore, each function of the server device 300 may be realized by using a virtual server function or the like on the cloud.

1 Vehicle tracking system 10 Vehicle 100 Transmitter (BLE tag)
110 Control unit 120 Identification ID management unit 130 BLE communication unit 150 Battery unit 200 Receiving device (terminal)
210 Control unit 211 Time/position information acquisition unit 212 Identification ID information receiving unit 213 Identification ID-specific log data transmitting unit 220 Storage unit 221 Identification ID-specific log data storing unit 230 Communication unit 231 Network communication unit 232 BLE communication unit 300 Server device 310 Control unit 311 Identification ID-specific log data receiving unit 312 Vehicle position estimation unit 320 Storage unit 321 Identification ID-specific log data storing unit 322 Map information storing unit 3221 Receivable range area information unit 323 Performance information storing unit 330 Communication unit 400 User terminal 500 Network

Claims (5)

a transmitter mounted on the vehicle and configured to transmit identification information by two types of radio waves having different communication reach distances;
a plurality of receiving devices that receive the identification ID from the two types of radio waves, respectively;
a server device including: a map unit having a road map; a receiving unit that receives, from the plurality of receiving devices, reception information of the identification IDs transmitted by the two types of radio waves together with position information of the receiving devices; and a vehicle position estimating unit that estimates the position of the vehicle by plotting reception conditions of the two types of radio waves on the road map;
A vehicle tracking system consisting of: The vehicle tracking system described in claim 1, characterized in that the two types of radio waves are a first radio wave having a first bit rate and a second radio wave having a higher bit rate and a shorter communication range than the first radio wave. The vehicle tracking system described in claim 1, characterized in that the vehicle position estimation unit plots the reception conditions of the two types of radio waves on the road map using map matching to estimate the most likely road. A vehicle tracking system as described in any one of claims 1 to 3, characterized in that the server device further includes performance information relating to the receivable ranges of the two types of radio waves for each model of receiving device as a performance information unit, and the vehicle position estimation unit estimates the position of the vehicle by plotting the reception status of the two types of radio waves on the road map based on the performance information. A vehicle tracking system as described in any one of claims 1 to 3, characterized in that the server device stores area information regarding the receivable ranges of the two types of radio waves according to the area in the map section, and the vehicle position estimation section estimates the vehicle's position by plotting the reception status of the two types of radio waves on the road map based on the area information.