Location Management System

Abstract

To provide a position management system for a wireless transmitter capable of covering a wide area for a long period of time at low cost. [Solution] The location management system 1 includes a wireless transmitter 2, a repeater 3, and a server 5, as described below. The wireless transmitter 2 transmits an individual signal containing individual information at predetermined time intervals. The repeater 3 acquires location information at predetermined time intervals and transmits identified location information, which is the location information with identification information attached, at predetermined time intervals. The server 5 receives and stores the identified location information transmitted from the repeater 3. The repeater 3 includes a mobile object and has a receiver 7 that receives the individual signal. When receiving the individual signal, the repeater 3 acquires the signal strength of the individual signal, stores the maximum strength value, which is the maximum value of the signal strength, and the time of maximum strength, which is the time at which the signal strength was reached, and transmits additional data that includes the individual information, maximum strength value, and maximum strength time attached to the identified location information. The server 5 calculates the location of the wireless transmitter from the additional data.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to a location management system, and more particularly to a location management system for wireless transmitters including mobile units in relays. [Background technology]

[0002] In recent years, location information services using GNSS (Global Navigation Satellite System) satellites have become commonplace. Therefore, a possible configuration for a position management system for wireless transmitters is to equip the wireless transmitters with a GNSS positioning unit. However, because the power consumption required for using GNSS satellites is large, incorporating a GNSS positioning unit into a small wireless transmitter and continuously acquiring and transmitting location information at predetermined intervals is limited to a few days due to the limited power capacity. As a result, it becomes difficult to operate the system for managing the location of wireless transmitters for a long period of time.

[0003] Therefore, a location management system using a gate check method that uses receivers installed at specific gates can be considered as a location management system that reduces the power consumption of wireless transmitters. However, since this configuration can only check for passage through a specific gate, it is difficult to say that this configuration is suitable for wide-area location management.

[0004] Also known is a system that uses Bluetooth (registered trademark) as a location management system for wireless transmitters. In such location management systems, it is common to determine whether a wireless transmitter has deviated from a predetermined route by determining whether the wireless transmitter has passed near a repeater (base station terminal) located on the predetermined route (see, for example, Patent Document 1).

[0005] However, in the configuration of Patent Document 1, the repeaters are configured as fixed or semi-fixed repeaters, so they can only accommodate pre-set routes, and are therefore significantly lacking in flexibility as a location management system for wireless transmitters.

[0006] Furthermore, because Bluetooth (registered trademark) uses the high-frequency band of 2.4 GHz, radio waves have a high tendency to travel in a straight line, meaning that the radio waves cannot travel around obstacles, and the effective transmission range of a wireless transmitter is only a few meters to a dozen meters. Therefore, in order to cover a wide area, it is necessary to increase the number of repeaters, which increases the introduction cost of building a location management system. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 5891468 Summary of the Invention [Problem to be solved by the invention]

[0008] The present disclosure has been made to solve the above problems, and its object is to provide a location management system for wireless transmitters that can cover a wide area inexpensively, for a long period of time. [Means for solving the problem]

[0009] The location management system of the present disclosure includes a wireless transmitter, a repeater, and a server, as described below. The wireless transmitter transmits an individual signal containing individual information at predetermined time intervals. The repeater acquires location information at predetermined time intervals, and transmits identified location information, which is the location information with identification information attached, at predetermined time intervals. The server receives and stores the identification location information transmitted from the repeater.

[0010] Here, the repeater includes a mobile unit and has a receiving unit that receives the individual signal. When an individual signal is received, the signal strength of the individual signal is acquired, the maximum strength value, which is the maximum value of the signal strength, and the time of maximum strength, which is the time at that time, are stored, and additional data is transmitted in which the individual information, maximum strength value, and maximum strength time are attached to the identification position information. The server also calculates the location of the wireless transmitter from the accompanying data. Furthermore, the moving body is a repeater fixed to a grounded moving medium.

[0011] The wireless transmitter does not acquire location information but simply transmits an individual signal at predetermined intervals for a short period of time, so that power consumption can be reduced and the transmission state can be maintained for a long period of time. Furthermore, since the repeaters include mobile units and have receiving units that receive individual signals, it is possible to cover a wide area with a small number of repeaters.

[0012] Furthermore, since the location information is acquired using a repeater with a relatively large power supply capacity, it is possible to maintain a reception state for a long period of time. Furthermore, because the repeater only stores the maximum intensity value and the time of the maximum intensity, even if the number of wireless transmitters increases, the storage capacity of the repeater is not strained. This allows the storage capacity of the repeater to be small, thereby reducing the cost of the repeater.

[0013] In other words, wireless transmitters with limited power capacity are only responsible for low-power transmissions, and a small number of repeaters with ample power capacity are used to obtain location information over a wide area, which consumes high power, thereby indirectly determining the location of the wireless transmitters. This makes it possible to provide a location management system for wireless transmitters that can cover a wide area for a long period of time at low cost. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram of a location management system (first embodiment). [Figure 2]FIG. 10 is an explanatory diagram of a specific example of a method for calculating the position of a wireless transmitter by a server (first embodiment); [Figure 3] FIG. 10 is an explanatory diagram of a location management system (embodiment 2). [Figure 4] FIG. 10 is an explanatory diagram of a specific example of a method for calculating the position of a wireless transmitter by a server (Example 2); DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, modes for carrying out the present disclosure will be described based on examples. It should be noted that the following examples disclose specific examples, and it goes without saying that the present disclosure is not limited to the following examples. [Example]

[0016] [Configuration of Example 1] The configuration of a location management system 1 according to the first embodiment will be described with reference to FIG. The location management system 1 includes a wireless transmitter 2, a relay 3, and a server 5, which will be described below. The wireless transmitter 2 transmits an individual signal at predetermined time intervals.

[0017] Here, the individual signal transmitted by the wireless transmitter 2 uses a specific low-power band that complies with the Radio Law of Japan. More specifically, the individual signal transmitted by the wireless transmitter 2 is a 920 MHz carrier wave onto which individual information is superimposed. The wireless transmitter 2 is carried by a pedestrian p and transmits an individual signal every 10 seconds for 10 ms. Since the wireless transmitter 2 is subject to location management by the location management system 1, it is preferable that the individual information includes direct or indirect unique information that can identify the wireless transmitter 2.

[0018] Furthermore, since the wireless transmitter 2 only transmits individual signals, it has a simple structure and can be easily miniaturized. In addition, the transmission period is short at 10 ms, so it consumes little power and can operate continuously for several months using a built-in power source (such as a secondary battery).

[0019] The repeater 3 acquires location information at predetermined time intervals, and transmits identified location information, which is the location information with identification information attached thereto, at predetermined time intervals. Then, the server 5 receives and stores the identification position information transmitted from the repeater 3. Here, the repeater 3 is a mobile object and has a receiving unit 7 that receives an individual signal. Since it is sufficient that the relay device 3 be distinguishable from other relay devices 3, the identification information may be highly anonymous and does not include information specific to the relay device 3.

[0020] More specifically, the repeater 3 has a GNSS positioning unit (not shown), acquires location information using GNSS satellites at 10-minute intervals, and transmits identification location information with identification information attached to the acquired location information at 10-minute intervals. The server 5 receives the identification location information transmitted by the repeater 3 via the Internet line i at intervals of 10 minutes, and stores the reception time and the location information of the repeater 3.

[0021] Here, the repeater 3 is a mobile object. More specifically, the repeater 3 is fixed to a moving medium v ​​such as a bus or an automobile, and is a moving body whose position changes as the moving medium v ​​moves.

[0022] The repeater 3 also has a receiving unit 7 that receives the individual signal. The receiver 7 receives the individual signal, decodes the individual signal, and extracts the individual information. When the receiver 7 receives the individual signal, it also acquires the signal strength of the individual signal.

[0023] The repeater 3 also has a storage unit 8 that stores individual information, signal strength, and the time when the individual signal was acquired. When a new individual signal for the same individual information is received, the signal strength is compared with that stored in memory unit 8, and if it exceeds the signal strength value stored in memory unit 8, the signal strength and the time when the signal was acquired are overwritten. As a result, the storage unit 8 stores, for each piece of individual information, the maximum signal strength value, which is the maximum value of the signal strength, and the time at which the signal strength reaches its maximum value.

[0024] Furthermore, the repeater 3 has a transmitter 10 that transmits the identification position information at 10-minute intervals. When the repeater 3 receives an individual signal, i.e., when individual information, etc. exists in the memory unit 8, the repeater 3 transmits the identification position information plus accompanying data including the maximum intensity value and maximum intensity time for each individual information to the server 5 via the Internet line i from the transmitter 10. After the additional data is transmitted to the server 5 via the transmission unit 10, the data in the storage unit 8 is reset by being filled with zeros or the like.

[0025] The server 5 calculates the position of the wireless transmitter 2 from the accompanying data. The server 5 is provided with a display unit 11 that displays the location of the wireless transmitter 2. The server 5 is configured to include a well-known microcomputer having a CPU and GPU with calculation functions, various storage devices such as ROM and RAM, input devices, and output devices, and is always connected to the Internet line i.

[0026] Here, a specific example of a method for the server 5 to calculate the position of the wireless transmitter 2 will be described with reference to FIG. For example, consider the case where the location information transmitted by relay device 3 is A at 10:00:00:00 and B at 10:10:00:00. Also, it is assumed that the individual information, maximum intensity value, and maximum intensity time of the incidental data at 10:10:00:00 are as shown in Table 1.

[0027] [Table 1]

[0028] The propagation loss (Loss (dB)) corresponding to the maximum intensity value at a distance d (m) from a transmitter of frequency f (MHz) is expressed by the following equation (1).

number

[0029] In FIG. 2, first, points A and B are connected by a straight line, and the movement of the repeater 3 over 10 minutes is approximated as a constant speed straight line. Next, a circular area corresponding to the maximum intensity value (-70 dB) is set with the position α corresponding to the maximum intensity time (10:03:35:50) of the individual information α as its center, and the area within this circular area is designated as the presence area of ​​the wireless transmitter 2 having the identification information α at the maximum intensity time. Similarly, a circular area corresponding to the maximum intensity value (-80 dB) is set with the position β corresponding to the maximum intensity time (10:08:40:80) of the individual information β as its center, and the area within this circular area is defined as the presence area of ​​the wireless transmitter 2 having the identification information β at the maximum intensity time.

[0030] Then, the server 5 displays the positions of the wireless transmitters 2 on map information (not shown) on the display unit 11, as shown in FIG. The display unit 11 may be provided in addition to the server 5, or may be displayed at a remote location via the Internet line i.

[0031] [Effects of Example 1] The location management system 1 of the present disclosure includes a wireless transmitter 2, a relay 3, and a server 5, which will be described below. The wireless transmitter 2 transmits an individual signal containing individual information at 10 second intervals. The repeater 3 acquires location information at 10-minute intervals, and transmits identified location information, which is the location information with identification information attached, at 10-minute intervals. The server 5 receives the identification position information transmitted from the repeater 3 and stores it.

[0032] Here, the repeater 3 is a mobile object and has a receiving unit 7 that receives an individual signal. When an individual signal is received, the signal strength of the individual signal is acquired, the maximum strength value, which is the maximum value of the signal strength, and the time of maximum strength, which is the time at that time, are stored, and additional data is transmitted in which the individual information, maximum strength value, and maximum strength time are attached to the identification position information. The server 5 also calculates the location of the wireless transmitter from the accompanying data.

[0033] The wireless transmitter 2 does not acquire location information and only transmits an individual signal at predetermined intervals for a short period of time, so that power consumption can be reduced and the transmission state can be maintained for a long period of time. Furthermore, the repeater 3 is a mobile body fixed to the mobile medium v ​​and has a receiving unit 7 that receives individual signals, so that a wide area can be covered with a small number of repeaters 3.

[0034] Furthermore, since the location information is acquired using the repeater 3, which has a relatively large power supply capacity, it is possible to maintain a receiving state for a long period of time. Furthermore, because the repeater 3 only stores the maximum intensity value and the time of maximum intensity, it is less likely to put strain on memory capacity even if the number of wireless transmitters 2 increases. This allows the storage capacity of the repeater 3 to be small, thereby reducing the cost of the repeater 3. This makes it possible to provide a location management system 1 for wireless transmitters 2 that can cover a wide area for a long period of time at low cost.

[0035] [Configuration of Example 2] The location management system 1 of the second embodiment will be described with reference to FIG. 3, focusing on the differences from the location management system 1 of the first embodiment. In the position management system 1 of the second embodiment, the moving medium v ​​has another position information acquisition device 20 (for example, a car navigation system).

[0036] Here, the location information acquisition device 20 has a GNSS positioning unit (not shown), acquires location information using GNSS satellites at intervals of 1 second, and stores the location information and the time when the location information was acquired in the memory unit 21 for a predetermined period of time. The time of the location information acquisition device 20 and the repeater 3 is synchronized in advance using a time server or the like.

[0037] When transmitting the identification position information, the repeater 3 refers to the storage unit 21 of the position information acquisition device 20, and further attaches the immediately preceding time, immediately preceding position information, immediately following time, and immediately following position information to the attached data. Here, the immediately preceding time is the time at which the position information acquisition device 20 acquires the immediately preceding position information immediately before the maximum intensity time. The immediately following time is the time at which the position information acquisition device 20 acquires the immediately following position information immediately after the maximum intensity time. It should be noted that the number of pieces of data referenced by the relay device 3 in the storage unit 21 is at most several hundred, so the load of data reference is not high.

[0038] Here, a specific example of a method for calculating the position of the wireless transmitter 2 by the server 5 will be described with reference to FIG. For example, consider the case where the location information transmitted by relay device 3 is A at 10:00:00:00 and B at 10:10:00:00. It is also assumed that the individual information, maximum intensity value, maximum intensity time, immediately preceding time, immediately preceding location information, immediately following time, and immediately following location information of the incidental data at 10:10:00:00 are as shown in Table 2. [Table 2]

[0039] In FIG. 4, first, point Aα and point Bα are connected by a straight line, and the movement of the repeater 3 over 1 second is approximated by a constant speed straight line. Next, a circular area corresponding to the maximum intensity value (-40 dB) is set with the position α corresponding to the maximum intensity time (10:03:35:50) of the individual information α as its center, and the area within this circular area is set as the presence area of ​​the wireless transmitter 2 having the individual information α at the maximum intensity time.

[0040] Similarly, first, point Aβ and point Bβ are connected by a straight line, and the movement of the relay device 3 during 1 second is approximated by a constant speed straight line. Next, a circular area corresponding to the maximum intensity value (-50 dB) is set with the position β corresponding to the maximum intensity time (10:08:40:80) of the individual information β as its center, and the area within this circular area is set as the presence area of ​​the wireless transmitter 2 having the individual information β at the maximum intensity time.

[0041] Then, the server 5 displays the position of the wireless transmitter 2 on map information (not shown) on the display unit 11, as shown in FIG. Furthermore, the display unit 11 can switch between wide-area and detailed display of the display object, and can display the positions A and B when in wide-area display. Note that the dotted line in the figure represents a straight line connecting A and B.

[0042] In addition, if the server 5 determines that the immediately preceding time, immediately preceding location information, immediately following time, immediately following location information, etc. of the accompanying data are clearly unreasonable, it will determine the location of the transmitter 2 using the identification location information, reception time, etc. transmitted by the repeater 3.

[0043] [Effects of Example 2] The accompanying data further includes immediately preceding position information acquired at the time immediately before the maximum intensity time, immediately following position information acquired at the time immediately after the maximum intensity time, the immediately preceding time, and the immediately following time. This makes it possible to further limit the location of the transmitter 2 based on the location information history of the storage unit 21 of the other location information acquisition device 20.

[0044] [Variations] The present invention can be modified in various ways without departing from the spirit of the invention. For example, in the embodiment, the carrier wave of the individual signal is 920 MHz, but there is no particular limitation as long as it uses a specific low-power band that complies with the Radio Law of Japan. Considering radio wave attenuation and the effective transmission range, the carrier frequency is preferably in the sub-GHz band of 300 MHz to 1 GHz.

[0045] In the embodiment, there is one repeater 3 and two wireless transmitters 2, but there may be a plurality of repeaters 3 and one wireless transmitter 2. This makes it possible to improve the accuracy of the position of the wireless transmitter 2 by using information from a plurality of repeaters 3 . Furthermore, the location management system 1 may have a plurality of relays 3 and three or more wireless transmitters 2.

[0046] In the embodiment, the transmission interval of the individual signal from the wireless transmitter 2 is set to 10 seconds and the transmission period is set to 10 ms, but the present invention is not limited to this embodiment. In order to prevent interference between the wireless transmitters 2 and ensure reliable reception by the repeater 3, it is preferable that the transmission interval be 1 to 30 seconds and the transmission period be 0.5 to 100 ms.

[0047] In the embodiment, the repeater 3 acquires the location information at 10-minute intervals and transmits the identification location information at 10-minute intervals, but the present invention is not limited to this mode. In order to acquire all signals from the multiple wireless transmitters 2 and to ensure the accuracy of the calculated positions of the wireless transmitters 2, it is preferable that the interval for acquiring the position information be 1 to 20 minutes.

[0048] In the embodiment, the wireless transmitter 2 is carried by the pedestrian p, but this is not a limitation. The wireless transmitter 2 may be attached to luggage or the like. If the wireless transmitter 2 is carried by the pedestrian p, it can be charged as needed, but if it is attached to luggage or the like, this is not possible, so there is a high practical benefit in long-term operation.

[0049] In the embodiment, the repeater 3 is a mobile body, but the repeater 3 may also include a fixed body. If the repeater 3 is a fixed body, a separate power supply can be provided from another location via a wired line, so that a more stable reception state can be maintained. Furthermore, if the repeater 3 is a fixed body, it does not move, and therefore the accuracy of the calculated position of the wireless transmitter 2 can be increased. [Explanation of symbols]

[0050] 1 Location management system 2 Wireless transmitter 3 Repeater 5 Server 7 Receiver

Claims

1. a wireless transmitter that transmits an individual signal containing individual information at predetermined time intervals; a repeater that acquires location information at predetermined time intervals and transmits, at predetermined time intervals, identified location information obtained by attaching identification information to the location information; a server that receives and stores the identification location information transmitted from the repeater; the repeater includes a mobile body and has a receiving unit for receiving the individual signal, and when receiving the individual signal, acquires the signal strength of the individual signal, stores a maximum strength value that is the maximum value of the signal strength and a maximum strength time that is the time at which the signal strength was reached, and transmits accompanying data in which the individual information, the maximum strength value, and the maximum strength time are attached to the identification position information; The server calculates the location of the wireless transmitter from the accompanying data; A location management system in which the mobile object is a relay fixed to a grounded mobile medium.

2. 2. The location management system of claim 1, wherein the accompanying data further includes immediately preceding location information acquired by another location information acquisition device at the time immediately preceding the maximum intensity time, immediately following location information acquired by the location information acquisition device at the time immediately following the maximum intensity time, the immediately preceding time, and the immediately following time.

3. 3. The position management system according to claim 1, wherein the frequency of the individual signal is 300 MHz to 1 GHz.

4. The location management system according to claim 3, further comprising a display unit that displays the location of the wireless transmitter.

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