JPH1066136A - Location detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a location detecting system which can detect location with high accuracy by using portable radio wave receiving source or transmitting source which is easy to carry and whose battery life is long. SOLUTION: This system is composed by connecting plural base stations 10 which communicate with a plurality of portable radio transmitter-receivers 30 to a computer 20 through a transmission line 50, and a transmitter-receiver 30 decides whether its location is within or outside the communication area 40 of a station 10, intermittently receives a signal in the case of its being outside the area 40, transmits an identification code only in the case when it is inside the area 40 and significantly extends its battery life.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a clean room,
The present invention relates to a location detection system that manages and displays the locations of a plurality of specific persons having radio wave transmission sources in places where a large number of people act, such as hospitals, offices, and specific areas or premises.

[0002]

2. Description of the Related Art Conventionally, in order to observe the behavior and location of a specific moving object such as a person, an animal, or a car, the moving object is carried with a radio wave transmitting source, and a radio wave transmitted from the moving source is detected. Receiving and tracking at has been done. Also, a card or a tag called a data carrier that communicates with a base station in a non-contact manner is used to recognize an identification code of a specific person when passing through a door or a gate. In recent years, GPS (Global positioning) using satellites
system) is used for car navigation.

[0003]

The method of carrying a radio wave source and detecting the direction is based on the principle of azimuth measurement. Therefore, azimuth and electric field strength are received at receiving facilities having directivity at least at two places at the same time. Therefore, it is necessary to specify the position by a triangulation method, and it is necessary to perform a complicated calculation in consideration of the positional relationship between the receivers in advance. Further, as disclosed in Japanese Patent Application Laid-Open No. 6-130141, a plurality of radio wave transmitting sources each transmit a different burst radio wave, and the electric field strength is measured by a plurality of arranged receiving electric field strength measuring instruments, and the nearest position is determined. In the system that detects the noise, the electric field strength fluctuates over time and position, and the accuracy is not high. The radio wave transmission source always transmits radio waves, so the battery life is short. I was For this reason, use for extremely limited applications has been limited.

On the other hand, in a system using a data carrier that communicates using a medium wave or a microwave, identification signals can be communicated with each other, and the accuracy is relatively high. However, the communication distance between the data carrier and the base station is less than a few meters, and identification information can be obtained when passing through gates and doors, but after passing that point, where is the person carrying the data carrier, It was impossible to detect a two-dimensional location.

[0005] The position detection method using the GPS requires a device in which a moving object receives radio waves from a plurality of satellites and performs advanced digital signal processing. You also need a direct view of the satellite,
It cannot be used indoors.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a simple structure and a high accuracy by using a portable radio wave receiving or transmitting source which is easy to carry and has a long battery life. It is an object of the present invention to provide a location detection system capable of two-dimensionally detecting a location where the location is high.

[0007]

In order to solve the above-mentioned problems, a location detecting system according to the present invention comprises a plurality of portable radio transceivers for transmitting an identification code, and communication between these portable radio transceivers. A plurality of base stations, and a computer that determines and displays the position information of the mobile from the registration status of the identification code from the plurality of base stations connected and input through these base stations and transmission lines, The portable dotted line transmitter / receiver determines that it is a communication area when a transmission request signal from a base station comes within a receivable range, and transmits an identification code.

[0008] Further, by arranging a plurality of cells as a communication area with a portable radio transceiver in one base station, the location of the portable radio transceiver is set within the range of the cell or adjacent thereto. This is to detect as an overlapping range of cells.

In addition, a transmitting function for transmitting an identification code is provided with a receiving function so that transmission is started after detecting a carrier from a base station.

[0010] Further, the communication area is arranged in a cell shape by making the communication distance of a plurality of base stations variable.

[0011] In addition, the transmission from a plurality of base stations is time-divided, the battery life of the portable radio transceiver is extended by considering the interference and overlap of the area, and a highly accurate mobile unit with a simple configuration is provided. The location is detected.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In a location detecting system according to the present invention, a portable radio transmitter / receiver detects the inside and outside of a communication area of a base station, instead of one-sided transmission as in the prior art. Send only within the area. At this time, the life of the battery can be extended by controlling the time setting of the intermittent reception / transmission. Further, the communication area of the base station is controlled by the transmission output and the reception sensitivity, and a plurality of base stations can be arranged in a cell to detect the position. Furthermore, since a plurality of base stations perform transmission in a time-division manner, interference can be prevented, and the position of the moving object can be detected two-dimensionally with high accuracy as information on overlapping areas.

[0013]

Embodiments of the present invention will be described below.

First, the portable wireless transceiver of the present invention has a receiving function, and determines whether the location of the portable wireless transceiver is inside or outside the communication area with the base station. This is performed by determining that the transmission request signal from the base station is within the communication area when the transmission request signal can be received. As a result, if the signal is intermittently received at relatively long intervals outside the area of the base station and the identification code is transmitted only within the area, the number of transmissions can be reduced compared to a conventional transmitter that always transmits. Can be reduced. In addition, since transmission is not performed during communication with a plurality of portable wireless transceivers in order to confirm a transmission request from the base station once, the possibility of collision of transmission information is reduced, and retransmission is further reduced. The number of times can be reduced. For this reason, the battery life can be greatly extended.

FIG. 1 shows functional blocks of a portable radio transceiver and a base station according to the present invention. The portable wireless transmitter / receiver 30 has a transmitter 31 and a receiver 32 built therein, and performs switching between transmission and reception and intermittent operation under the control of a computer (CPU) 33. This is for downsizing and power consumption reduction. Reference numeral 34 denotes an antenna, and SW denotes a changeover switch. In the base station 10, a signal from the antenna 11 is separated by the filter 12 and taken into the receiver 13, a position registration request is transmitted from the transmitter 15 under the control of the computer (CPU) 14, and a signal is transmitted from the portable wireless transceiver 30. Is always managed.

Next, FIG. 2 shows an example of the configuration of a location detection system according to the present invention. Base station (10-1, 10-
2,... 10-K,... 10-N When it is not necessary to distinguish each other, simply use 10. The same applies to other codes). The two-dimensionally arranged cells (the communication area with the portable radio transceiver 30 in one base station 10 is one cell) are arranged two-dimensionally. Communication area (4
0-1, 40-2,..., 40-K,... 40-N) are arranged and adjusted, and the computer 20 and the transmission line 50 are connected. Portable wireless transceiver (30-1, 30-2,
.. 30-K,... 30-N) are the respective communication areas 4
0, the base station 10 corresponding to the communication area 40
The computer 20 displays the position of each portable wireless transceiver 10 on the display 21 two-dimensionally as a bright spot, a symbol, or an identification code. The figure shows an example of a display state when the portable wireless transceiver 30-1 exists in the communication area 40-1 of the base station 10-1. When the portable wireless transceiver 30-1 moves and enters the communication area 40-2 of the base station 10-2, the transceiver 30-1 registers the position with the base station 10-2. The communication area 4 on the computer screen.
Displayed at position 0-2. Since the identification code of the transceiver 30-1 cannot be detected in the communication area 40-1 before the movement, the display information is deleted.

As described above, by arranging the communication areas 40 of the plurality of base stations 10 in a cell shape and transmitting the position registration information between the base station areas to the computer 20, the two-dimensional portable radio transceiver 30 is provided. Can be detected.

In FIG. 2, a communication area 40 of each base station 10 is shown.
There is a gap (blind spot) in the area, but as shown in FIG.
If the communication distance is adjusted to further reduce the cell size, the blind spot can be reduced, and a finer position in a smaller range can be detected.

The cell radius can be changed if the transmission and reception sensitivities of the base station 10 are made variable. For example, by making the antenna 11 of the base station 10 a rod antenna and making the antenna length variable, or making the resistances of the transmission and reception devices 15 and 13 variable, it is possible to easily adjust the transmission and reception sensitivity, and to improve the use conditions and detection. It can respond according to the accuracy.

Furthermore, when a plurality of base stations 10 are arranged, radio waves from the base stations 10 may interfere with each other to make communication difficult. However, the clocks of the plurality of base stations 10 are synchronized. By transmitting a registration request by time sharing without simultaneously transmitting radio waves from adjacent base stations 10, interference can be prevented and the position accuracy can be further improved.

FIG. 4 shows the timing of emission of radio waves from the base station 10 by time division. The radio waves from the N base stations 10 are sequentially transmitted every T time.
During this transmission time, the portable wireless transceiver 30 receives the transmission request and transmits the self-identification code for the time t. If the timing is set such that the product of the number N of portable radio transceivers and the identification code transmission time t falls within the base station transmission time T, processing corresponding to the number of portable radio transceivers 30 can be performed. . FIG. 5 shows a configuration example of a communication area cell in the present time division method.

Here, the communication area 40 of one base station 10 overlaps with the other two communication areas 40.
Now, four portable wireless transceivers 30-1 to 30-4 exist in the communication area 40-1. In the timing shown in FIG.
No interference occurs due to the emission of the radio wave, and the portable radio transceivers 30-1 to 30-4 are recognized and their positions are registered. In the next T to 2T, only the portable wireless transceiver 30-3 in the communication area 40-2 is detected. Portable radio transceiver 3 from two base stations 10-1 and 10-2
Computer 20 receiving identification code for 0-3
Determines the overlapping part of the registration positions of the two base stations 10-1 and 10-2, and the portable radio transceiver 30-3 sets the overlapping area of the communication areas 40-1 and 40-2 (shaded area). Section), it is possible to specify a narrower area of the area cell and display the position information. The location of the portable wireless transceiver 30-4 in the overlapping area of the communication areas 40-1 and 40-3 can be similarly specified. Even when the number of overlapping areas becomes three, the position can be obtained in the same procedure. By combining such positional information from a plurality of base stations 10, it is possible to perform fine-grained location detection in a narrow range of the communication area 40 of one base station 10 or less.

If the transmission period T of the base station 10 is lengthened, a large number of portable radio transceivers 30 can be detected. However, there is a trade-off that the following of the movement of the transceiver between the communication areas is slowed down. There is an optimal time-division time based on the moving speed and the number of moving objects to perform, but by combining a plurality of these overlapping cell structures for performing the time-division, a wide range can be covered as a whole. .

6A, 6B, and 6C, the controller 1 is connected between the computer 20 and the base station 10, and each base is connected to the LAN as shown in FIGS. 6 (a), 6 (b) and 6 (c). The station 10 and the computer 20 may be connected. If used by connecting to a LAN, various application systems such as telephone transfer of position information obtained by the present system, electronic mail, and access control to various OA devices can be constructed.

[0025]

As described above, in the location detection system of the present invention, the portable radio transmitter detects the inside and outside of the communication area of the base station, instead of the conventional one-sided transmission. Therefore, since the transmission is made only within the area, the life of the battery can be extended. Further, since the communication areas are arranged in a cell shape, the location can be accurately detected. Further, since the communication area of the base station is changed according to the actual situation, interference can be prevented and the position of the moving object can be detected two-dimensionally with high accuracy. And it can be used indoors where GPS cannot be used. The portable wireless transceiver is
Since the identification code is transmitted intermittently after determining the presence or absence of the transmission request radio wave from the base station, a portable wireless transceiver having a small size, light weight and long battery life can be used. Furthermore, there is an effect that it is simple and can be applied to various systems.

[Brief description of the drawings]

FIG. 1 is a diagram showing functional blocks of a base station and a portable wireless transceiver in the present invention.

FIG. 2 is a diagram showing a configuration example of a location detection system according to the present invention.

FIG. 3 is a diagram showing an example of a cell arrangement in a communication area according to the present invention.

FIG. 4 is a timing chart of transmission of a base station and transmission of a plurality of portable transceivers by time division in the present invention.

FIG. 5 is a diagram showing an example of position detection at the time of area overlap according to the present invention.

FIG. 6 is a diagram illustrating a configuration example of a location detection system according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Radio base station 11 Antenna 12 Filter 13 Receiver 14 CPU 15 Transmitter 20 Computer 30 Portable radio transceiver 31 Transmitter 32 Receiver 33 CPU 34 Antenna 40 Communication area 50 Transmission line

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Hiroshi Ichinose 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (5)

[Claims] 1. A location detection system for managing and measuring the location of a mobile object, comprising: a plurality of portable wireless transceivers transmitting an identification code; and a plurality of base stations communicating with the portable wireless transceivers. And a computer that obtains and displays position information of the mobile unit from the registration status of the identification code from the plurality of base stations connected and input to the base station via a transmission line, and the portable radio A location detection system, wherein the transceiver determines that the transmission request signal from the base station is within a communication area and transmits an identification code when the transmission request signal is within a communication area. 2. A communication area with a portable wireless transceiver in one base station is defined as one cell, and a plurality of such cells are arranged so that the location of the portable wireless transceiver is within a cell range or adjacent to the cell. 2. The location detection system according to claim 1, wherein the location is detected as an overlapping range of cells. 3. The method according to claim 1, wherein the plurality of base stations transmit radio waves in a time-division manner based on mutually synchronized clock pulses, and request each portable wireless transceiver to transmit an identification code. The location detection system according to claim 1. 4. The location detection according to claim 1, wherein the plurality of base stations change transmission and reception sensitivities to change communication distances with the plurality of portable wireless transceivers. system. 5. The portable radio transceiver intermittently receives the presence or absence of a transmission request radio wave from a base station, and transmits an identification code after receiving the transmission request radio wave from the base station. Item 3. The location detection system according to Item 1.