Vehicle tracking system

Abstract

The present invention tracks the position and direction of travel of a stolen vehicle.　This vehicle tracking system is provided with a server device comprising: a receiving unit that receives, in chronological order by means of a plurality of receiving devices, an identification ID transmitted from a transmitting device that is installed in a vehicle and that is capable of transmitting the identification ID using two types of radio waves having different communication arrival distances, and that receives, in chronological order from the plurality of receiving devices, reception information of the identification ID by means of the two types of radio waves, together with position information of each reception device; and a vehicle position estimating unit that estimates the position and direction of travel of the vehicle by chronologically plotting reception states of the two types of radio waves on a road map.

Description

Vehicle Tracking System

[0001] The present invention relates to a vehicle tracking technology that utilizes wireless communication technology, and in particular to a vehicle tracking system that receives the vehicle ID, which is installed in the vehicle and transmitted by two types of radio waves with different reachable communication distances, in chronological order by multiple terminals, and further plots the vehicle ID in chronological order on a road map in a server device, thereby estimating the vehicle's position and direction of movement.

[0002] Vehicle theft has become a social problem, and technologies for preventing theft and tracking vehicles after theft have been developed. In recent years, stolen vehicle tracking technologies utilizing wireless communication technology have been developed. For example, Patent Document 1 discloses a vehicle tracking system that notifies a vehicle tracking server, via a hotspot device, of other vehicle IDs obtained through vehicle-to-vehicle communication, enabling tracking of a stolen vehicle without using a mobile phone or PHS. However, the technology described in Patent Document 1 requires each vehicle to be equipped with a communication device for vehicle-to-vehicle communication. Therefore, this technology is difficult to apply to vehicles such as motorcycles, where it is difficult to install a wireless communication device for vehicle-to-vehicle communication due to price constraints, etc.

[0003] Patent No. 4015925

[0004] 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.

[0005] The present invention has been made in consideration of these problems. The present invention provides a stolen vehicle tracking system including a server device that includes a receiving unit that receives, in time series, an identification ID transmitted from a transmitter mounted on a vehicle and capable of transmitting the identification ID via two types of radio waves with different communication reach, using a plurality of receivers, and receives, in time series, reception information of the identification ID via the two types of radio waves along with position information of each receiver from the plurality of receivers, and a vehicle position estimation unit that estimates the position and direction of movement of the vehicle by plotting the reception status of the two types of radio waves on a road map in time series. This makes it possible to accurately track a stolen vehicle by, for example, simply equipping the stolen vehicle with an inexpensive radio tag as a transmitter.

[0006] (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, a plurality of receivers (e.g., a "terminal 200" described later) that receive the identification ID from the two types of radio waves, a map unit (e.g., a "map information storage unit 322" described later) that includes a road map, and a map information storage unit 322 that stores road maps and information about the receivers. The server device (e.g., "server device 300" described later) includes a receiving unit (e.g., "log data receiving unit by identification ID" described later) that receives reception information of the identification ID by the two types of radio waves in chronological order along with location information, and a vehicle position estimating unit (e.g., "vehicle position estimating unit 312" described later) that estimates the position and direction of movement of the vehicle by plotting the reception status of the two types of radio waves on the road map by map matching that estimates the most probable road based on the chronological order.

[0007] According to (1) above, a vehicle is equipped with a transmitter that emits radio waves with two types of communication reach, and the identification ID emitted by the transmitter is received in time series from a plurality of receivers, which receive the identification ID transmitted by the transmitter in time series along with the location information of the receiver, and reception information of the identification ID transmitted by the two types of radio waves is received in time series.The reception status of the two types of radio waves is plotted on a road map by map matching, which estimates the most likely road based on the time series, and therefore it is possible to accurately track the vehicle's position and direction of movement.

[0008] (2) In the vehicle tracking system described in (1) above (e.g., the "Vehicle Tracking System 1" described later), the two types of radio waves may be characterized as a first radio wave having a first bit rate (e.g., the LR described later) and a second radio wave having a higher bit rate and a shorter communication reach than the first radio wave (e.g., the 1MPHY described later).

[0009] According to (2) above, it is possible to accurately track a vehicle by simply equipping the vehicle with, for example, an inexpensive wireless tag.

[0010] (3) In the vehicle tracking system described in (1) or (2) above (e.g., the "vehicle tracking system 1" described below), the server device may further include a performance information unit (e.g., the "performance information storage unit 323" described below) that stores performance information regarding the receivable ranges of the two types of radio waves for each model of the receiving device, 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.

[0011] According to (3) above, it is possible to track vehicles more accurately by taking into account the performance of the receiving device.

[0012] (4) In the vehicle tracking system described in (1) or (2) above (for example, the "vehicle tracking system 1" described later), 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.

[0013] According to (4) above, it is possible to track vehicles more accurately by taking into account urban areas where the radio wave coverage is narrow and suburban areas where the radio wave coverage is wide.

[0014] According to the present invention, for vehicles such as motorcycles, which are difficult to install wireless communication devices in due to price constraints, it is possible to accurately track the location and direction of movement of the vehicle, for example, in the event of theft, by simply equipping the vehicle with an inexpensive wireless tag.

[0015] FIG. 1 is a diagram showing the basic configuration of an entire embodiment of the present invention. FIG. 1 is a diagram showing a state when a receiving device receives radio waves with a short communication reach in an embodiment of the present invention. FIG. 2 is a diagram showing a state when multiple receiving devices receive radio waves with a long communication reach in an embodiment of the present invention. FIG. 3 is a diagram showing a state when multiple receiving devices receive radio waves from a stolen vehicle in chronological order in an embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a transmitting device (BLE tag) in an embodiment of the present invention. FIG. 5 is a diagram showing the configuration of a receiving device (terminal) in an embodiment of the present invention. FIG. 6 is a diagram showing the configuration of a server device in an embodiment of the present invention. FIG. 7 is a diagram showing area information related to a normal radio wave reception range and area information related to a narrower than normal radio wave reception range on map information in an embodiment of the present invention. FIG. 8 is a flowchart showing the operation of a receiving device when transmitting two types of radio waves with different reach from a BLE tag as a transmitting device to a terminal as a receiving device in an embodiment of the present invention. FIG. 9 is a flowchart showing the operation of a server device when transmitting position information of a tracked vehicle such as a stolen vehicle from a terminal as a receiving device in an embodiment of the present invention to a server device.

[0016] Next, an embodiment of the present invention will be described in detail with reference to the drawings.

[0017] 1 , in this embodiment, a 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.

[0018] In this embodiment, a Bluetooth (registered trademark) 5.0 or higher BLE tag is used as an example of a transmitting device 100 mounted on a vehicle 10 and transmitting 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 a BLE tag 100. BLE is an abbreviation for Bluetooth (registered trademark) Low Energy, and operates for long periods of time, such as several years, using power supplied by a coin-type lithium battery. 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 distances are in the order of 2MPHY < 1MPHY < Coded PHY. Hereinafter, Coded PHY will also be referred to as "Long Range" or abbreviated as "LR."

[0019] 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. However, 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 described below, the BLE tag 100 switches between the two types of radio waves (LR and 1MPHY) at a preset switching period and broadcasts an "advertisement packet" including the identification ID of the BLE tag 100. For example, if the switching period 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 the vehicle ID. Therefore, in the following description of this embodiment, the identification ID of the BLE tag 100 mounted on the vehicle 10 is also referred to as the "vehicle ID."

[0020] The receiving device 200 may, for example, support Bluetooth® 5.0 (i.e., support 1MPHY and LR), be equipped with a GPS unit, acquire location information for the receiving device 200, and enable each receiving device 200 to acquire synchronized time information. Furthermore, as described below, the receiving device 200 may have a terminal function for responding to requests from the server device 300. For example, the receiving device 200 may be a mobile terminal such as a smartphone. However, 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® 5.0 (i.e., support 1MPHY and LR), is equipped with a GPS, acquires location information for the receiving device 200, and enables each receiving device 200 to acquire synchronized time information. Alternatively, a communication device installed in the vehicle 10 may be used. Furthermore, such a receiving device 200 may be installed in a predetermined location, such as a house or a utility 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."

[0021] 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 time information when the advertising packet was received and location information of the terminal 200 when the packet was received together in the storage unit 220 (log data storage 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 transmitted the advertising packet (i.e., the vehicle 10 equipped with the BLE tag 100) is located within a communication reachable distance from the location of the terminal 200 at that time according to the type of radio waves received.

[0022] The communication range depends on the performance of the terminal 200, the radio wave environment, etc. Therefore, in this embodiment, as will be described later, performance information regarding the receivable ranges of two types of radio waves (1MPHY and LR) may be set in advance in the server device 300 for each model of the terminal 200. Furthermore, taking into consideration areas with poor radio wave environments (e.g., urban areas) where the communication range of radio waves is narrow and areas with good radio wave environments (e.g., suburbs) where the communication range of radio waves is wide, area information regarding the radio wave environment may be set in the server device 300 on a map.

[0023] 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 an ID broadcast from the BLE tag 100 mounted on the vehicle 10 and a program for responding to a request for log data for each 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 packet broadcast from the BLE tag 100, the terminal 200 can receive advertising packets containing a 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). The terminal 200 can also respond to requests from the server device 300. Therefore, the terminal 200 owned by a user who uses the vehicle tracking system 1 (i.e., who owns the vehicle 10) may serve as a receiving device.

[0024] The server device 300 is a server device that performs management related to, for example, a 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 the terminal 200, time information when the advertising packet was received, and location information of the terminal 200 when the packet was received, and manage the information 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.

[0025] In response to a request from the user terminal 400, the server device 300 initiates a search process for, for example, the location information and movement direction of a stolen vehicle. Specifically, based on the vehicle ID designated by the user terminal 400 as the stolen vehicle, the server device 300 references 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 reception time, the location information of the terminal 200, and the type of radio waves received). The server device 300 can then estimate the location and movement direction of the stolen vehicle by plotting the reception status of the radio waves 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. Thus, 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.

[0026] 2A is a diagram showing the transmission and reception state of radio waves, in which a solid line indicates an area in which the terminal 200 can receive advertising packets from the BLE tag 100, and a dashed line indicates an area in which the BLE tag 100 can transmit advertising packets. As shown in FIG. 2A , if the terminal 200 receives radio waves (e.g., 1 MPHY) with a short communication range, it can be determined that the vehicle equipped with the BLE tag 100 is located on a road near the terminal 200.

[0027] On the other hand, even if none of the terminals 200 receives radio waves with a short communication reach, it can be estimated that there is a high probability that multiple terminals 200 are receiving radio waves with a long communication reach (e.g., LR). Figure 2B is a diagram showing the transmission and reception state of radio waves, in which the area in which each terminal 200 can receive an advertising packet from the BLE tag 100 is represented by a solid line and the area in which the BLE tag 100 can transmit an advertising packet is represented by a dashed line. In this way, as shown in Figure 2B, it can be determined that the vehicle equipped with the BLE tag 100 is located on a road located in an area (common area) that is the intersection of circular areas centered on the positions of each terminal 200 and having a radius equal to the communication reach of the packets broadcast from the BLE tag 100. Note that, for a terminal 200 that has not received a packet broadcast from the BLE tag 100, if there is an area (referred to as a "deletion area") in which a circular area having a center at the position of the terminal 200 and a radius equal to the communication reach of the packet broadcast from the BLE tag 100 overlaps with 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 by switching between radio waves with a long communication reach and radio waves with a short communication reach at short intervals, and thereby the server device 300 can estimate the location of, for example, a stolen vehicle with a fairly high probability.

[0028] Regarding the direction of movement of the stolen vehicle, if another terminal 200 receives an advertising packet from the stolen vehicle before the time at which the terminal 200 receives an advertising packet from the stolen vehicle, it can be estimated that the stolen vehicle is moving from the position of the stolen vehicle at which the other terminal 200 received the packet before the time at which the other terminal 200 received the packet in the direction of the position of the stolen vehicle at which the 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 the terminal 200 receives the advertising packet from the stolen vehicle, it can be estimated that the stolen vehicle is moving from the position of the stolen vehicle at which the terminal 200 received the advertising packet from the stolen vehicle in the direction of the position of the stolen vehicle at which the other terminal 200 received the packet after the time at which the terminal 200 received the packet from the stolen vehicle.

[0029] 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 within which terminal 200 can receive 1MPHY packets, and the outer circle indicates the range 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 within which the BLE tag can transmit 1MPHY packets, and the outer circle indicates the range within which terminal 200 can transmit LR packets. FIG. 2C shows, in chronological order, how the stolen vehicle enters the range within which each terminal 200 can receive LR packets, then enters the range within which 1MPHY packets can be received, and then passes through the range within which the stolen vehicle can receive LR packets before exiting an area within which LR packets cannot be received. In this way, by plotting the reception status of two types of radio waves from a 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 accurately track which roads and in which direction the stolen vehicle is traveling. Note that FIG. 2C illustrates a display format in which the server device 300 plots the location of the stolen vehicle based on the reception status as seen from the location of the terminal 200. Alternatively, the server device 300 may display on the road map the reception status as seen from the location of the stolen vehicle 10 that broadcasts the advertising packet (the range of transmission distances for an MPHY packet centered on the stolen vehicle and the range of transmission distances for an LR packet centered on the stolen vehicle). In either case, the display method described above ensures that the location of the stolen vehicle is always plotted on the 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.

[0030] The user terminal 400 is a terminal operated by a user who is searching for a stolen vehicle, for example. Hereinafter, such a user who is searching for a stolen vehicle will be referred to as a "search request user." If the user owns the terminal 200 as a receiving device, the user may use the terminal 200 as the user terminal 400.

[0031] The search requesting user operates the user terminal 400 to send a request to start a search process for the location information and moving direction of the stolen vehicle to the server device 300. In this way, as described above, the server device 300 acquires time-series information related to the vehicle ID (such as the reception time, 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 and moving direction of the stolen vehicle by plotting the reception status of the two types of radio waves on a road map, and can output 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 and moving direction of the stolen vehicle at that time.

[0032] As described above, in this embodiment, each device cooperates to perform a search process, making it possible for the search requesting user to search for the location information of a stolen vehicle selected as a search target.

[0033] 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 by, 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, for example, a network realized by a combination of a mobile phone network, the Internet, an intranet, or the like.

[0034] 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, via a local area network (LAN) or an intranet. As described above, if a user has a terminal 200 as a receiving device, the terminal 200 may be used as the user terminal. The outline and configuration of the vehicle tracking system 1 in this embodiment have been described above. Next, the functions of these devices will be described.

[0035] First, functional blocks included in the BLE tag 100 as a transmitting device will be described with reference to Fig. 3. As shown in Fig. 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.

[0036] The battery unit 150 is a battery that supplies power to the control unit 110, the ID management unit 120, and the BLE communication unit 130. The BLE tag 100 is a so-called active tag because it is driven by the power supplied by the battery unit 150. The battery unit 150 is realized by, for example, a coin-type lithium battery. The BLE tag 100 operates 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 cycle of the BLE communication unit 130. Note that a battery mounted on the vehicle 10 may be used as the battery unit 150.

[0037] The identification ID management unit 120 manages the identification ID (vehicle ID) that is an identifier for identifying the vehicle 10 equipped with the BLE tag 100 described above.

[0038] 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 in accordance with switching control of the control unit 110. Note that in this embodiment, the interval is set to one second, but is not limited to this.

[0039] The control unit 110 switches between two types of radio waves (LR and 1MPHY) based on a preset cycle, for example, every second, to broadcast 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. This allows the terminal 200 to receive advertising packets from BLE tags 100 located within the two communication reachable distances (short distance and long distance) of the terminal 200 every second. Based on the received advertising packet, the terminal 200 can thereby identify the vehicle ID of the packet sender and 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, for example, a vehicle (e.g., a two-wheeled vehicle) with an average speed of approximately 20 km / h. Therefore, even if the stolen vehicle is traveling, the distance that the vehicle 10 moves per second is approximately 5.5 meters, which is considered to be within the margin of error in 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, the functional blocks included in the terminal 200 will be described with reference to FIG. 4.

[0040] As shown in FIG. 4, the terminal 200 includes a control unit 210 , a storage unit 220 , and a communication unit 230 .

[0041] The control unit 210 is configured with an arithmetic processing device such as a microprocessor, and controls each unit that configures the terminal 200. Details of the control unit 210 will be described later.

[0042] The storage unit 220 is configured with a semiconductor memory or the like, and stores various programs such as control programs called firmware or operating systems, 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 "identification ID-specific log data") including identification ID information, etc. included in advertising packets received from each BLE tag 100, linked to the identification ID information, such as the type of radio wave (LR or 1MPHY) through which the identification ID information was received, time information at which the advertising packet including the identification information was received, and location information of the terminal 200 at the time the advertising packet was received. For this reason, the storage unit 220 includes, in addition to programs, an identification ID-specific log data storage unit 221 that stores, as chronological information, identification ID-specific log data created based on the identification ID information included in advertising packets received from each BLE tag 100. The storage unit 220 has been described above.

[0043] The communication unit 230 includes a network communication unit 231 having a DSP or the like and communicating with the server device 300 or 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. A LAN (Local Area Network) may also be included as part of the network.

[0044] Next, the control unit 210 will be described in detail. The control unit 210 is configured by 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 the RAM, ROM, and storage unit 220, writes information to the RAM and storage unit 220, and exchanges signals with the communication unit 230. In this way, the processing in this embodiment is realized by the cooperation of hardware and software (programs).

[0045] The control unit 210 includes, as functional blocks, a time / location information acquisition unit 211 , an ID information reception unit 212 , and an ID-specific log data transmission unit 213 .

[0046] When the ID information receiving unit 212 described later receives ID identification information of any BLE tag 100 by an advertising packet, the time / location information acquiring 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 time information provided by the terminal 200, and the location information may be current location information (GPS information) provided by the terminal 200.

[0047] When the terminal 200 receives one or both of the advertising packets transmitted by switching between two types of radio waves (LR and 1MPHY) from the BLE tag 100 every period (for example, every second), the identification ID information receiving unit 212 creates one record (referred to as "identification ID-specific log data") linked to the identification ID, including the type of radio waves (either LR or 1MPHY, or both) at the time of receiving the packet, information about the identification ID received by the advertising packet, time information at which the advertising packet was received, and location information of the terminal 200 at the time of receiving the advertising packet, and stores the record in the identification ID-specific log data storage unit 221 as described above. As a result, by referring to the identification ID-specific log data, it is possible to determine that the terminal 200 was located within a communication reachable distance corresponding to the type of radio waves from the location of the vehicle 10 identified by the identification ID (vehicle ID) at the time indicated by the time information included in the identification ID-specific log data. As described above, when a packet containing the vehicle ID is received via 1MPHY, it can be determined that the terminal 200 is located within a short distance from the vehicle 10 (referred to as a "short distance area"). Furthermore, if there is another terminal 200 that received the same identification ID at the same time, it can be determined that the other terminal 200 is located within a communication reachable distance corresponding to the type of radio wave (a "long distance area") from the vehicle 10 identified by the identification ID (vehicle ID). In this case, when the location of the vehicle 10 is viewed from the locations of the terminal 200 and the other 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 location of the terminal 200 and a long distance area centered on the location of the other terminal 200. In this way, when multiple terminals 200 receive a packet containing the vehicle ID at the same time, the area containing the location of the vehicle 10 can be estimated quite accurately. Note that although the packets are said to be received at the same time, as described above, even if there is a slight time difference, it can be treated as a range of error. 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 provided later in the explanation of the server device 300, but by further performing map matching with road maps and building position information, etc., it is possible to determine the vehicle's position on the road and direction of movement quite accurately (assuming a range of error is allowed).

[0048] When the server device 300 (described later) requests ID-specific log data associated with a specified ID, the ID-specific log data transmission unit 213 transmits the terminal ID and the ID-specific log data associated with 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 associated with the ID, the time information of which belongs to the specified time range. This enables the server device 300 to estimate the location and direction of the vehicle 10 within the time range, as described later. Note that when the server device 300 pre-specifies the ID of the vehicle 10 to be tracked, the ID-specific log data transmission 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 enables the server device 300 to estimate the current location and direction of the vehicle 10. Next, with reference to FIG. 5 , functional blocks included in the server device 300 will be described.

[0049] As shown in FIG. 5, the server device 300 includes a control unit 310 , a storage unit 320 , and a communication unit 330 .

[0050] The control unit 310 is configured with an arithmetic processing device such as a microprocessor, and controls each unit constituting the server device 300. The control unit 310 will be described in detail later.

[0051] The memory unit 320 is composed of, for example, a hard disk, a semiconductor memory, etc., and stores various programs such as control programs called firmware or operating systems, and programs for causing the control unit 310 to function as a log data receiving function by identification ID, a vehicle position estimation function, etc., and is also equipped with a log data memory unit by identification ID 321, a map information memory unit 322, and a performance information memory unit 323.

[0052] As will be described later, 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. Here, the collection of identification ID-specific log data is a collection of records that includes, for each vehicle ID (the identification ID of a BLE tag mounted on a vehicle), time information at which the terminal 200 received an advertising packet including the vehicle ID, the terminal ID of the terminal 200 that received the advertising packet, location information of the terminal 200 at the time of receiving the advertising packet, and the type of radio wave at the time of receiving the advertising packet (LR or 1MPHY). Note that the collection of identification ID-specific log data is time-series information based on the time information.

[0053] The map information storage unit 322 includes information on features such as roads and facilities, road information, facility location information, parking lot information, and the like. Road information stores so-called road map information such as road types and traffic lights. Facility information stores location information of each general facility as latitude and longitude information. Parking lot information stores location information of parking lots as latitude and longitude information. The map information storage unit 322 may also include display map data for displaying backgrounds of roads, road maps, and the like.

[0054] The map information storage unit 322 may further include a receivable range area information unit 3221. The receivable range area information unit 3221 may include area information relating to two types of radio wave receivable ranges, taking into account that, for example, urban areas have a narrower radio wave reach (shorter reach distance) than normal, while suburban areas have a wider reach. FIG. 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 1M, while the narrow range area shows, for example, a reach distance of 70 m when receiving LR and 50 m when receiving 1M. The receivable range area information may be obtained by measuring the reach distance on-site.

[0055] The performance information storage unit 323 stores information that pre-sets the receivable ranges (reach distances) of the two types of radio waves corresponding to model information (information that identifies the model of the terminal 200) linked to the terminal ID of the terminal 200, since the reach distances of the two types of radio waves vary depending on the model of the terminal 200. In this case, the reach 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 reach distances on-site. Note that it is expected that the reach distances of the two types of radio waves from the same BLE tag 100 will vary depending on the area where the terminal 200 is located and that the reach distances of the two types of radio waves from the same BLE tag 100 will also vary depending on the model of the terminal 200. Therefore, the reach distance range may be set for each model of the main terminal 200 in each area according to the model and area by measuring the reach distances on-site for each model of the terminal 200. The storage unit 320 has been described above.

[0056] The communication unit 330 has a DSP or the like, and communicates with the terminal 200 or 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 local area network (LAN) may also be included as part of the network.

[0057] Next, the control unit 310 will be described in detail. The control unit 310 is configured by 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 exchanges signals with the communication unit 330. In this way, the processing in this embodiment is realized by the cooperation of hardware and software (programs).

[0058] The control unit 310 includes, as functional blocks, an ID-specific log data receiving unit 311 and a vehicle position estimating unit 312 .

[0059] When a user requests, via the user terminal 400, the location information and movement direction of a tracked vehicle, such as a stolen vehicle, for which a vehicle ID (the identification ID of the BLE tag installed on the vehicle) is specified, the identification ID-specific log data receiving unit 311 specifies, for example, a time range and requests each terminal 200 for 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 it 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. Note that, 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 time information when each terminal 200 received an advertising packet including the vehicle ID, location information of the terminal 200 at the time the advertising packet was received, and the type of radio waves (LR or 1MPHY) at the time the advertising packet was received, and stores the set in the identification ID-specific log data storage unit 321. The identification ID-specific log data receiving unit 311 stores the set of identification ID-specific log data as chronological information in the order of the time 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.

[0060] 2C , the vehicle position estimation unit 312 determines, based on position information of each terminal 200 that 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 reachability 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, it is possible to identify the road on which the tracked vehicle is located and the movement direction. As described above, if there is a terminal 200 located within a communication reachable distance from the overlapping area (common area) that can receive the packet but that has not received a packet broadcast from the tracked vehicle (mounted BLE tag 100), the area obtained by subtracting the deletion area calculated based on the position of the terminal 200 from the overlapping area may be determined as the overlapping area in which the tracked vehicle (mounted BLE tag 100) is located. The location information of the vehicle at a certain time may be plotted on a road map, for example, based on multiple log data within a range of several seconds before and after the time (in seconds). This makes it possible to identify the road on which the tracked vehicle (mounted BLE tag 100) is traveling and its location on the road. In this way, by mounting a BLE tag 100 that emits radio waves with two different communication reachable distances on the vehicle 10 and receiving the identification ID transmitted by the BLE tag 100 at multiple terminals 200, the location and movement direction of the vehicle can be estimated. Furthermore, the position of the vehicle being tracked is always plotted on a road map, making it possible to track the vehicle accurately while increasing visibility.

[0061] As described above, the vehicle position estimation unit 312 may refer to the receivable range area information unit 3221 and plot the radio wave reachable range from the location information on a road map on the map information based on the area information regarding the receivable ranges of the two types of radio waves, thereby taking into account the influence of the radio wave environment in the area on the communication reachable distance. This makes it possible to track the vehicle's position and movement direction more accurately by taking into account urban areas with narrow radio wave reachable ranges and suburban areas with wide reachable ranges.

[0062] Similarly, as described above, the vehicle position estimation unit 312 may refer to the performance information storage unit 323 and plot the reception conditions of the two types of radio waves on the road map based on performance information regarding the receivable ranges of the two types of radio waves for the model of the terminal 200, thereby taking into account the difference in communication reach distance depending on the model. This makes it possible to track the position and movement direction of the vehicle more accurately by 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 Figures 7 to 9.

[0063] 7 is a flowchart showing the operation of each terminal 200 as a receiving device when receiving two types of advertising packets switched every second from each BLE tag 100 as a transmitting device. That is, each terminal 200 is in a state where it can receive advertising packets from each BLE 100 in parallel unless the terminal 200 is stopped, and performs the operation shown below.

[0064] Referring to Figure 7, in step S10, each terminal 200 checks whether or not it has received an advertising packet that is broadcast by switching between two types of radio waves (LR and 1MPHY) every predetermined switching period (e.g., 1 second).

[0065] In step S11, if the terminal 200 receives any advertising packet, the process proceeds to step S12. If the terminal 200 has not received any advertising packet, the process proceeds to step S10.

[0066] In step S12, the terminal 200 acquires time information when the advertising packet is received and location information of the terminal 200 when the advertising packet is received.

[0067] In step S13, log data by identification ID is created as time-series information, linking the information on the identification ID received by the advertising packet, the radio wave type of the advertising packet, the time information at which the advertising packet was received, and the location information of the terminal 200 at the time the advertising packet was received to the vehicle ID (the identification ID of the BLE tag installed in the vehicle).

[0068] In step S14, the terminal 200 stores the created log information in the storage unit 220 (ID-specific log data storage unit 221), and then proceeds to step S10.

[0069] By operating in this manner, each terminal 200 can record log information (log data by identification ID) of the BLE tag 100 when the BLE tag 100 is located within a communication reach range where it can receive an advertising packet using at least one of the two types of radio waves (LR and 1MPHY) from the BLE tag 100.

[0070] Figure 8 is a flowchart showing the operation of the server device 300, when a user requests location information of a tracked vehicle, such as a stolen vehicle, via the user terminal 400, to obtain from each terminal 200 the radio wave reception status from the stolen vehicle stored in the terminal 200.

[0071] 8, in step S20, the server device 300 determines whether or not information on the location and direction of movement of 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.

[0072] In step S21, the server device 300 specifies a time range and requests each terminal 200 to transmit 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) received during that time range.

[0073] In step S22, the server device 300 acquires from each terminal 200 log data by identification ID linked to the vehicle ID of the tracked vehicle.

[0074] In step S23, the server device 300 generates a time-series set of log data by identification ID, including location information of the terminal 200 at the time of receiving the advertising packet including the vehicle ID within the specified time range, and the type of radio wave (LR or 1MPHY) at the time of receiving the advertising packet, based on the time information of the terminal 200. Then, the process proceeds to step S30.

[0075] Figure 9 is a flowchart showing the operation of the server device 300 to estimate the position and direction of movement of the stolen vehicle by acquiring the radio wave reception status from the stolen vehicle stored in each terminal 200 from each terminal 200 as described above, and plotting the radio wave reception status from the stolen vehicle in time series on a road map based on the generated time series set of log data by identification ID.

[0076] 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 coverage area in which the terminal 200 can receive the radio waves on a road map.

[0077] In step S31, the server device 300 plots, on a road map in chronological order, the overlapping area of ​​the coverage area where radio waves can be received by each terminal 200 that received radio waves from the stolen vehicle. As described above, if there is a terminal 200 that is located within a communication coverage area where it can receive the packet from the overlapping area but has not received the packet broadcast from the tracked vehicle, the server device 300 may plot, on the road map, an area obtained by subtracting the deletion area calculated based on the position of that terminal 200 from the overlapping area.

[0078] In step S32, the server device 300 identifies roads that match each overlapping area plotted in chronological order on the road map and the location of the stolen vehicle. If two or more roads are identified, the server device 300 may identify, as the most likely road where the stolen vehicle is located, for example, the road on which the terminal 200 is located, a road that is free of buildings or the like that would cause radio wave interference between the terminal 200 and its location, or a road that is continuously connected to the road identified before and after the time.

[0079] In step S33, the server device 300 displays the identified roads and the positions of the stolen vehicles on the roads in chronological order on a road map.

[0080] In step S34, the server device 300 identifies the direction of movement of the stolen vehicle based on the position of the stolen vehicle on the road displayed in chronological order, and displays the direction of movement in chronological order on the road map.

[0081] In step S35, if the server device 300 is still requested to identify the location and direction of movement of the stolen vehicle, the process proceeds to step S21. If the server device 300 has finished identifying the location and direction of movement of the stolen vehicle, the process proceeds to step S20.

[0082] The above has described the operation of the vehicle tracking system 1, which makes it possible to estimate the position and direction of movement of a vehicle 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 types of communication reach.

[0083] Each device can be realized by hardware, software, or a combination of these. Furthermore, the navigation method performed by the cooperation of each device included in the navigation system can also be realized by hardware, software, or a combination of these. Here, "realized by software" means that it is realized by a computer reading and executing a program.

[0084] 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, programmable ROMs (PROMs), erasable PROMs (EPROMs), flash ROMs, random access memories (RAMs)), solid-state drives (SSDs), etc. The program may also be supplied to a computer by various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transient computer-readable media can be supplied to a computer via wired communication paths such as electric wires and optical fibers, or via wireless communication paths.

[0085] 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 the present invention can be implemented in various modified forms within the scope that does not deviate from the gist of the present invention.

[0086] <Variation 1> In the above-described embodiment, each terminal 200 creates identification ID-specific log data based on advertising packets received from each BLE tag 100. However, this is not limiting. Each terminal 200 may not create identification ID-specific log data for advertising packets received from BLE tags 100 other than the stolen vehicle specified by the server device 300, but may create identification ID-specific log data only for the BLE tag 100 of the specified stolen vehicle. This allows each terminal 200 to reduce the load on the control unit 210 and the capacity of the memory unit 220, while protecting privacy information regarding the location information of vehicles other than the stolen vehicle. Furthermore, the server device 300 may only identify the road, the location on the road, and the direction of movement of the stolen vehicle after the vehicle was stolen. This allows privacy information regarding the location information of the vehicle before the vehicle was stolen to be protected.

[0087] <Modification 2> In the above-described embodiment, the location information and movement direction of a stolen vehicle are tracked, but this is not limited to this. The system can be used to track the location information and movement direction of a vehicle 10 related to the user (e.g., a vehicle 10 used by the user's family, etc.). Furthermore, for example, the system can be used by the operating authorities to track the location information and movement direction of a vehicle 10 related to a crime (e.g., a vehicle used or used by a criminal, etc.).

[0088] <Variation 3> Displaying Stolen Vehicle Location and Direction of Movement in Real Time In the above-described embodiment, the location and direction of movement of a stolen vehicle at a specified time are tracked. However, this is not limiting. For example, the location and direction of movement 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 location information and time information for ID-specific log data associated with the vehicle ID of the tracked vehicle (the identification ID of the BLE tag mounted on the vehicle) received after the current time. Furthermore, the server device 300 may request each terminal 200 to transmit ID-specific log data associated with the vehicle ID of the tracked vehicle each time the log data is created in the future. In this way, the server device 300 can update the time-series set of ID-specific log data based on the ID-specific log data associated with the vehicle ID of the tracked vehicle received in real time from each terminal 200. This allows the server device 300 to estimate the current location information and direction of movement 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 as time-series data.

[0089] Although the above embodiment has been described as implementing the server device 300 using a single server device or the like, it may be implemented as a distributed processing system in which the functions of the server device 300 are distributed across multiple server devices as appropriate. Furthermore, the functions of the server device 300 may be implemented using a virtual server function or the like on a cloud.

[0090] DESCRIPTION OF SYMBOLS 1 Vehicle tracking system 10 Vehicle 100 Transmitting device (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 storage 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 storage unit 322 Map information storage unit 3221 Receivable range area information unit 323 Performance information storage unit 330 Communication unit 400 User terminal 500 Network

Claims

1. A vehicle tracking system comprising: a transmitter mounted on a vehicle that transmits identification ID information using two types of radio waves with different communication reach; a plurality of receivers that receive the identification ID from the two types of radio waves; a server device that includes: a map unit that has a road map; a receiver unit that receives, in time series, reception information of the identification ID via the two types of radio waves along with position information of the receiver from the plurality of receivers; and a vehicle position estimation unit that estimates the position and direction of movement of the vehicle by plotting the reception status of the two types of radio waves on the road map using map matching that estimates the most likely road based on the time series.

2. A vehicle tracking system as described in claim 1, wherein 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.

3. A vehicle tracking system as described in claim 1 or 2, characterized in that the server device further includes a performance information section that stores performance information regarding the receivable ranges of the two types of radio waves for each model of receiving device, and the vehicle position estimation section 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.

4. A vehicle tracking system as described in claim 1 or 2, characterized in that the server device has area information regarding the reception range of the two types of radio waves according to the area in the map section, and the vehicle position estimation section 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 area information.

Images