JP2004325272A - Positioning system, terminal, base station and information providing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the position of a terminal including the kind thereof with a simple constitution. <P>SOLUTION: A base station 4 emits an electromagnetic wave, receives a reflected wave from a terminal 2, and measures the position of the terminal 2 based on the round-trip time of the electromagnetic wave and the incident direction of the reflected wave. Each terminal 2 changes the intensity of the reflected wave following a rule assigned for discrimination from other terminals, and the base station 4 discriminates the terminal 2 of a reflection source based on the received reflected wave and the rule. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a positioning system for detecting the position of each of one or more terminals, a terminal and a base station used in the positioning system, and information for providing a terminal with an information service according to the position obtained by the positioning system. Regarding the provision system.
[0002]
[Prior art]
As a method of measuring the position of the terminal, there are a method of calculating the distance from a plurality of base points and a method of calculating the distance and the azimuth from the base point.
[0003]
As an example of a method of calculating a position based on distances from a plurality of base points, a method using GPS (Global Positioning System) is generally used. In mobile phones, etc., the distance between the terminal and each base station is measured at base stations at three points by measuring the electromagnetic wave electric field strength and electromagnetic wave travel time by comparing time stamps, and the like. ing.
[0004]
In addition, there is a laser radar system as a method of calculating a position based on a distance and an angle from a base point. In this method, the position of an object is measured by scanning the laser emission direction and measuring the travel time of the laser.
[0005]
In addition to these, Patent Document 1 discloses an optical communication method. In this optical communication method, a plurality of directional optical transmitting units and optical receiving units are radially provided on the outer surface of each of the transmitting and receiving optical transceivers. At the start of communication, on the transmitting side, the optical receiving units are all enabled, and the optical transmitting units are sequentially enabled independently to transmit predetermined signals. Then, a response signal from the receiving side to the transmission is received, and the optical receiving unit having the best receiving state and the optical transmitting unit having directivity in the same direction as the optical receiving unit are enabled one by one, Others are invalidated. On the other hand, the receiving side receives the light transmitted from the transmitting side in a state where all the optical receiving units are in the valid state. Then, among the plurality of optical receiving units, the optical receiving unit having the best receiving state and the optical transmitting unit having directivity in the same direction as the optical receiving unit are enabled, the others are disabled, and a predetermined response signal is transmitted. Send to the side. Thus, both the transmitting side and the receiving side can perform communication with the directivity in which the receiving state becomes the best.
[0006]
[Patent Document 1]
JP-A-10-285116
[0007]
[Problems to be solved by the invention]
However, in the above-described conventional technology, the configuration of the base station or the terminal becomes complicated.
[0008]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a positioning system, a terminal, a base station, and a positioning system capable of detecting which terminal exists at which position with a simple configuration. The purpose of the present invention is to provide an information providing system using the information.
[0009]
[Means for Solving the Problems]
A first aspect of the present invention for solving the above-described problems and achieving the object includes one or more base stations and one or more terminals, and each terminal includes a reflection unit that reflects an electromagnetic wave, and another terminal. Intensity control means for changing the intensity of the reflected wave by the reflection means according to the rule assigned for the determination of, each said base station, emission means for emitting an electromagnetic wave, emitted by the emission means Receiving means for receiving a reflected wave of the electromagnetic wave reflected by the reflecting means; distance measuring means for measuring a distance to the terminal based on a time difference between emission of the electromagnetic wave and reception of the reflected wave; and the receiving means Terminal determination means for determining the terminal of the reflection source based on the reception result by and the rule assigned to each terminal, using the measurement result of the distance measurement means and the determination result of the terminal determination means Each of the above A positioning system for detecting the end positions.
[0010]
In the above configuration, the distance from the base station to the terminal is measured based on the round trip time of the electromagnetic wave. In addition, a rule for discriminating between itself and another terminal is assigned to each terminal, and each terminal changes the intensity of the reflected wave according to the assigned rule. Then, the base station refers to the above rule and determines the terminal of the reflection source based on the received reflected wave. For this reason, detecting which terminal is present at which position is realized with a simple configuration. Note that the intensity control means includes those that change the intensity of the electromagnetic wave incident on the reflection means, those that change the intensity of the electromagnetic wave radiated from the reflection means, and those that change the reflectance of the reflection means.
[0011]
Further, in a second aspect based on the first aspect, the base station further includes a direction measuring unit that measures a direction of the terminal based on an incident direction of the reflected wave received by the receiving unit, The position of each terminal is detected by further using the measurement result of the direction measuring means.
[0012]
In a third aspect based on the first or second aspect, a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity are assigned to each terminal as the rule.
[0013]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the reflection means reflects the electromagnetic wave back and forth in an incident direction of the electromagnetic wave.
[0014]
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the emission means emits an electromagnetic wave modulated by a signal, and the terminal receives an electromagnetic wave from the emission means. And demodulating means for demodulating the electromagnetic wave received by the electromagnetic wave receiving means and extracting the signal.
[0015]
Further, the sixth invention is characterized in that the reflecting means for reflecting the electromagnetic wave emitted from the base station to detect the position of one or more terminals, and the reflecting means according to a rule assigned for discriminating from other terminals And intensity control means for changing the intensity of the reflected wave due to the terminal.
[0016]
In a seventh aspect based on the sixth aspect, a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity are assigned as the rules.
[0017]
In an eighth aspect based on the sixth or seventh aspect, the reflection means reflects the electromagnetic wave back and forth in the incident direction of the electromagnetic wave.
[0018]
In a ninth aspect based on any of the sixth to eighth aspects, the electromagnetic wave receiving means for receiving an electromagnetic wave modulated by a signal and emitted from the base station, and demodulating the electromagnetic wave received by the electromagnetic wave receiving means And demodulating means for extracting the signal.
[0019]
Further, a tenth invention is a base station that measures the position of one or more terminals, and includes an emission unit that emits an electromagnetic wave, and an electromagnetic wave emitted by the emission unit reflected by the terminal. Receiving means for receiving a reflected wave having an intensity according to the assigned rule; distance measuring means for measuring a distance to the terminal based on a time difference between emission of the electromagnetic wave and reception of the reflected wave; and And a terminal discriminating means for discriminating a reflection source terminal based on a reception result by the means and a rule assigned to each terminal.
[0020]
According to an eleventh aspect, in the tenth aspect, the apparatus further comprises a direction measuring means for measuring a direction of the terminal based on an incident direction of the reflected wave received by the receiving means.
[0021]
In a twelfth aspect based on the tenth or eleventh aspect, a time slot for increasing reflection intensity and a time slot for decreasing reflection intensity are assigned to each terminal as the rule.
[0022]
In a thirteenth aspect based on any one of the tenth to twelfth aspects, the emission means emits an electromagnetic wave modulated by a signal.
[0023]
A fourteenth invention is a positioning system according to any one of the first to fifth inventions, and an information providing means for providing information corresponding to the position of the terminal detected by the positioning system to the terminal by wireless communication. And an information providing system having:
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of an information providing system and a positioning system according to the present invention will be described in detail from first to third embodiments with reference to the accompanying drawings.
[0025]
(1st Embodiment)
FIG. 1 is a schematic diagram showing the overall configuration of the information providing system according to the present embodiment. In FIG. 1, a server 1 and a plurality of terminals 2 in a room R can wirelessly communicate with each other via an access point 3 (hereinafter, referred to as an AP 3) installed on a ceiling of the room R. Here, AP3 is a master station, and terminal 2 is a slave station. In addition, as a wireless communication method, for example, there are a wireless LAN of IEEE 802.11a standard and IEEE 802.11b standard, and Bluetooth (registered trademark). The server 1 provides information corresponding to the position of the terminal 2 to the terminal 2. On the ceiling of the room R, one or more base stations 4 for detecting the position of the terminal 2 are provided. is set up. It is assumed that the contents provided by the information provider are registered in the server 1 in advance.
[0026]
The operation of such an information providing system will be briefly described. First, the base station 4 measures the distance from the base station 4 to the terminal 2 and the direction of the terminal 2 with respect to the base station 4, and transmits the measurement result to the server 1. The server 1 detects the position of the terminal 2 based on the measurement result received from the base station 4 and the known position of the base station 4, and transmits information corresponding to the detected position via the AP 3 to the terminal. Send to 2.
[0027]
Communication between the server 1, the AP 3, and the base station 4 may be wireless or wired. Further, since the server 1, the AP 3, and the base station 4 are functionally separated, any combination may be implemented in the same device. Further, the installation position of the AP 3 and the base station 4 may be a place other than the ceiling, or may be outdoors.
[0028]
FIG. 2 is a schematic diagram illustrating the entire configuration of the positioning system according to the present embodiment. In FIG. 2, base stations 41 and 42 are installed on the ceiling of the room R in order to detect the positions of the terminals 21 and 22 in the room R. The base stations 41 and 42 radiate electromagnetic waves and measure the positions of the terminals 21 and 22 using reflected waves from the terminals 21 and 22. Specifically, the base stations 41 and 42 measure the distance to the terminals 21 and 22 based on the time difference between the emission of the electromagnetic wave and the reception of the reflected wave, that is, the round-trip time of the electromagnetic wave, and the base stations 41 and 42 of the reflected wave. The directions of the terminals 21 and 22 are measured based on the incident directions to the terminals. The measurement results of the base stations 41 and 42 are transmitted to the server 1, and the server 1 detects the positions of the terminals 21 and 22 based on the measurement results.
[0029]
Here, as shown in FIG. 2, the electromagnetic wave from the base station 41 does not reach the terminal 21 or the terminal 22 which is in the shadow of the holder when viewed from the base station 41. Therefore, the base station 41 cannot measure the position of the terminal 22. However, according to another base station 42, the position of each of the terminals 21 and 22 can be measured. Thus, considering the problem of shadow, it is preferable that the number of base stations 4 is two or more. However, the number of base stations 4 may be one.
[0030]
In FIG. 2, attention is paid to electromagnetic waves radiated from the base station 42. The electromagnetic wave from the base station 42 is reflected by the terminals 21 and 22, and the reflected wave from the terminal 21 and the reflected wave from the terminal 22 enter the base station 42. Then, the reflected electromagnetic waves from the terminals 21 and 22 enter the base station 42 at the same time or at close time intervals, and it becomes difficult for the base station 42 to determine the terminals 21 and 22. Therefore, in the positioning system according to the present embodiment, the terminals 21 and 22 change the intensity of the reflected waves in accordance with the rule assigned to each terminal for discrimination from other terminals, and the base stations 41 and 42 The terminal of the reflection source is determined based on the reflected wave and the above rule. This method will be described later in detail.
[0031]
FIG. 3 is a schematic diagram showing a configuration of the base station 4. In FIG. 3, the base station 4 has a substantially conical wide-angle lens 4a. At the apex of the wide-angle lens 4a, there is provided a light source 4b such as a laser or an LED (Light Emitting Diode) that emits an electromagnetic wave, and on the entire bottom surface of the wide-angle lens 4a, a PD (Photo Diode) or a CCD is provided. (Charge Coupled Device) and the like are arranged. In addition to these, the base station 4 has a distance measuring unit 4d for measuring the distance to the terminal 2, a direction measuring unit 4e for measuring the direction of the terminal 2, and a terminal determining unit 4f for determining the terminal 2 of the reflection source. . The base station 4 having such a configuration is attached with the bottom surface of the wide-angle lens 4a facing the ceiling.
[0032]
FIG. 4 is a schematic diagram illustrating a configuration of the terminal 2. 4, a housing 2a of the terminal 2 is provided with a reflector 2b for reflecting electromagnetic waves. In the present embodiment, the reflector 2b is a recursive reflector that reflects the electromagnetic wave back in the incident direction of the electromagnetic wave in order to efficiently reflect the electromagnetic wave. Specifically, the reflector 2b is formed by coating a support with a microsphere formed of glass, plastic, or the like, or by forming a corner cubed cube brick (CCC) on the surface. In addition, the housing 2a is provided with an intensity varying unit 2c that can change the intensity of the reflected wave so as to cover the reflector 2b. The intensity varying section 2c is not particularly limited as long as it can change the intensity of electromagnetic waves incident on the reflector 2b from the outside or the intensity of electromagnetic waves radiated from the reflector 2b to the outside. It is a shutter. Further, the terminal 2 has an intensity control unit 2d that controls the intensity of the reflected wave by controlling the intensity variable unit 2c.
[0033]
Hereinafter, the measurement of the position of the terminal 2 by the base station 4 will be described with reference to FIGS.
[0034]
The position (x, y, z) of the terminal 2 on the three-dimensional orthogonal coordinates with the base station 4 as the origin is obtained from the spherical coordinates (d, θ, φ). Therefore, in the present embodiment, the position of the terminal 2 is obtained by measuring the distance d from the base station 4 to the terminal 2 and the rotation angle θ and the elevation angle φ of the terminal 2 with respect to the base station 4.
[0035]
The light source 4b emits pulsed electromagnetic waves at appropriate intervals. The electromagnetic wave radiated from the light source 4b is reflected by the reflector 2b of the terminal 2, and the reflected wave L1 is collected by the wide-angle lens 4a and received by the light receiving element array 4c. Here, the reflected wave L1 incident on the wide-angle lens 4a from the directions of the rotation angle θ and the elevation angle φ is a portion (x1) on the two-dimensional orthogonal coordinates corresponding to the rotation angle θ and the elevation angle φ in the area of the light receiving element array 4c. , Y1). The light receiving element array 4c outputs a light receiving signal to the distance measuring unit 4d and the direction measuring unit 4e. The distance measuring unit 4d calculates the time difference between the emission of the electromagnetic wave and the reception of the reflected wave, multiplies the time difference by the speed of light, and divides by 2 to calculate the distance d from the base station 4 to the terminal 2. The direction measuring unit 4e converts the element part (x1, y1) of the light receiving element array 4c that has responded to the reflected wave L1 into a rotation angle θ and an elevation angle φ, and calculates the rotation angle θ and the elevation angle φ of the terminal 2 with respect to the base station 4. Ask.
[0036]
Hereinafter, determination of the reflection source terminal 2 will be described.
[0037]
In FIG. 1, when the terminal 2 transmits a registration request to the server 1 via the AP 3, the server 1 allocates a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity to the terminal 2 via the AP 3. This time slot is allocated to each terminal 2 so that a plurality of terminals 2 do not return reflected waves to the base station 4 at the same time. That is, it is set so that only one terminal 2 can reflect an electromagnetic wave from the base station 4 in a certain time slot. The server 1 transmits to the base station 4 time slot allocation information indicating the status of time slot allocation to each terminal 2.
[0038]
FIG. 5 is a diagram illustrating an example of time slot allocation. In FIG. 5, a time slot s11 for increasing the reflection intensity is assigned to the terminal 21 of FIG. 2 in the first half of the unit cycle T, and a time slot s12 for decreasing the reflection intensity is assigned in the second half. On the other hand, to the terminal 22, a time slot s21 to be weakened is assigned in the first half, and a time slot s22 to be strengthened is assigned in the second half. The intensity control units 2d of the terminals 21 and 22 control the intensity variable unit 2c so that electromagnetic waves are transmitted in the time slots s11 and s22 for increasing the reflection intensity, and the electromagnetic waves are blocked in the time slots s12 and s21 for weakening the reflection intensity. The intensity variable section 2c is controlled so as to be controlled.
[0039]
In FIG. 5, when the light source 4b of the base station 4 emits an electromagnetic wave at the time t1 in the time slots s11 and s21, this electromagnetic wave is strongly reflected by the terminal 21, and the reflected wave by the terminal 21 is the time in the time slots s11 and s21. At t2, the light is received by the light receiving element array 4c of the base station 4. Here, the reflected wave by the terminal 22 is hardly received. The received signal of the light receiving element array 4c is output to the terminal discriminating unit 4f, and the terminal discriminating unit 4f discriminates the reflection source terminals 21 and 22 based on the received signal and the time slot allocation information. Here, the reception time t2 of the reflected wave is within the time slot s11 assigned to the terminal 21 to increase the reflection intensity and within the time slot s21 assigned to the terminal 22 to decrease the reflection intensity. Terminal is recognized as the terminal 21.
[0040]
As described above, according to the present embodiment, each terminal 2 changes the intensity of the reflected wave in accordance with the rule assigned for discriminating from the other terminals 2, and the base station 4 Therefore, the terminal 2 can be determined with a simple configuration. In particular, a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity are assigned to each terminal, and the terminal 2 of the reflection source is determined based on the assignment status and the reception result of the reflected wave. The intensity control and the determination of the terminal 2 are realized with a very simple configuration.
[0041]
In addition, the position measurement method used in the conventional GPS and mobile phones can be applied only in an environment in which electromagnetic waves are not blocked from a satellite or a base station for mobile communication to a mobile terminal. It is not applicable when wireless communication between the outside and inside is difficult as in the above. On the other hand, according to the present embodiment, since the configuration of the base station is very simple, the base station can be arranged indoors, and the position can be detected indoors.
[0042]
Furthermore, since the recursive reflector is used as the reflector 2b of the terminal 2, the radiated electromagnetic wave from the base station 4 returns to the base station 4 more reliably than in the case where a reflector that performs omnidirectional diffuse reflection is used. In addition, interference with electromagnetic waves radiated from other base stations 4 can be avoided. Further, since the intensity of the reflected wave by the reflector 2b is increased, the influence of noise such as a reflected wave by an object other than the terminal 2 such as a wall can be reduced. For this reason, the problem of the multipath in which the probe reflected by the object other than the terminal 2 becomes noise and lowers the position measurement accuracy is reduced. Further, since the intensity of the reflected wave increases, the intensity of the electromagnetic wave from the base station 4 can be reduced.
[0043]
In addition, the terminal 2 does not need to have a device that generates an electromagnetic wave for position measurement, so that the terminal 2 can be reduced in weight and power consumption.
[0044]
Further, in the conventional laser radar system, a mechanism for scanning a laser is required. As a scanning mechanism, there is a scanning mechanism using a galvanometer or MEMS (Micro Electro-Mechanical Systems). However, since mechanical movement cannot be excluded, durability during continuous use is a problem. On the other hand, according to the present embodiment, a mechanism for scanning the electromagnetic wave is not required, and the durability can be improved.
[0045]
Further, since only one light source 4b is required, power consumption of the base station 4 can be reduced, and manufacturing and control can be facilitated, as compared with the optical communication device described in Patent Document 1 which requires a plurality of light sources. .
[0046]
Also, the measurement of the travel time of the electromagnetic wave can be performed with a precision of about several ns by a measuring system including a simple electric circuit, and a position error of about 1 m can be easily achieved. That is, the position of the terminal 2 can be accurately detected with a simple configuration.
[0047]
In addition, since one base station 4 basically measures the position, precise time synchronization between the base stations or between the terminal 2 and the base station 4 is not required.
[0048]
In addition, since the intensity of the reflected wave returning to the base station 4 can be controlled on the terminal side, if a user interface for setting the state of the intensity variable unit 2c is added, an information providing system using position information can be provided. Participation or non-participation can be determined by the user on the terminal side. Thereby, the user of the terminal 2 can determine whether to inform the information provider of his / her own position, and the privacy of the user can be protected.
[0049]
(Second embodiment)
FIG. 6 is a schematic diagram illustrating the entire configuration of the positioning system according to the present embodiment, and is a view of the room R viewed from the ceiling side. Note that the overall configuration and operation of the information providing system are almost the same as in the first embodiment, and a description thereof will be omitted. In FIG. 6, base stations 43, 44, and 45 are installed on the ceiling of the room R in order to detect the position of the terminal 23 in the room R. The base stations 43, 44, and 45 measure the distance to the terminal 23 based on the time difference between the emission of the electromagnetic wave and the reception of the reflected wave. In the positioning system according to the present embodiment, the position of the terminal 23 is calculated by triangulation based on the three distances measured by the base stations 43, 44, and 45 and the known positions of the base stations 43, 44, and 45. I do. This calculation may be performed by any device such as the base station 43 and the server 1.
[0050]
Here, when a certain terminal is shaded when viewed from a certain base station, the distance of the certain terminal from the base station cannot be measured. Therefore, it is preferable that the number of base stations is larger. However, at least three base stations are required to perform triangulation. Further, for example, when it is desired to detect only a distance from a certain point, one base station may be arranged at that point. That is, the number and arrangement position of the base stations may be determined according to the purpose and situation.
[0051]
FIG. 7 is a schematic diagram showing the configuration of the base station 43. 7, the base station 43 includes a wide-angle lens 43a, a light source 43b, a condenser lens 43c, a light receiving element 43d, a distance measuring unit 43e, and a terminal determining unit 43f. The light source 43b emits an electromagnetic wave. This electromagnetic wave is reflected by the terminal 23, and the reflected wave is condensed by the wide-angle lens 43a and the condensing lens 43c and received by the light receiving element 43d such as a PD. The light receiving element 43d outputs a light receiving signal to the distance measuring unit 43e and the terminal determining unit 43f, and the distance measuring unit 43e and the terminal determining unit 43f measure the distance and determine the terminal, respectively.
[0052]
Note that the configuration of the terminal 23, the measurement of the position of the terminal, and the determination of the terminal are almost the same as those in the first embodiment, and thus description thereof is omitted.
[0053]
As described above, according to the present embodiment, in addition to the effect obtained in the first embodiment, an effect that the configuration of the base station is simplified can be obtained.
[0054]
(Third embodiment)
The positioning system according to the present embodiment is almost the same as the positioning systems according to the first and second embodiments, but wirelessly transmits a signal from a base station to a terminal using a light source that emits electromagnetic waves for position detection. Things. Hereinafter, the present embodiment will be described with reference to the drawings, but description of parts common to the first and second embodiments will be omitted.
[0055]
FIG. 8 is a schematic diagram illustrating a configuration of the base station according to the present embodiment. 8, the base station 46 includes a wide-angle lens 46a, a light source 46b, a light receiving element array 46c, a distance measuring unit 46d, a direction measuring unit 46e, and a terminal discriminating unit 46f, as in the first embodiment. The base station 46 emits an electromagnetic wave modulated with an information signal in addition to an electromagnetic wave for position detection.
[0056]
FIG. 9 is a schematic diagram illustrating a configuration of a terminal according to the present embodiment. In FIG. 9, the terminal 24 includes an enclosure 24a, a reflector 24b, an intensity variable unit 24c, an intensity control unit 24d, an electromagnetic wave reception unit 24e that receives an electromagnetic wave from a base station, and reception by the electromagnetic wave reception unit 24e. And a demodulation unit 24f for demodulating the obtained electromagnetic wave and extracting an information signal. In the present embodiment, the reflector 24b is made of glass or acrylic and is translucent. Therefore, the reflector 24b transmits a part of the incident electromagnetic wave without reflecting or absorbing the whole electromagnetic wave. Therefore, in the present embodiment, a light receiving element such as a PD is installed inside the reflector 24b as the electromagnetic wave receiving unit 24e, and receives the electromagnetic wave transmitted through the reflector 24b. However, the installation position of the electromagnetic wave receiving unit 24e is not particularly limited as long as the electromagnetic wave can be received.
[0057]
Hereinafter, operations of the base station 46 and the terminal 24 when the information signal is wirelessly transmitted from the base station 46 to the terminal 24 will be described.
[0058]
In the base station 46, the light source 46b emits pulsed electromagnetic waves at appropriate intervals for terminal position detection, and also increases the reflection intensity assigned to the terminal 24 to which the information signal is to be transmitted. An electromagnetic wave modulated with an information signal is radiated into the slot. Note that the modulation method includes direct modulation and external modulation, but the method is not particularly limited here. Further, the light source 46b includes a signal source and a modulator.
[0059]
In the terminal 24, the electromagnetic wave receiving unit 24e receives an electromagnetic wave from the base station 46 and outputs a received signal to the demodulation unit 24f. The demodulation unit 24f demodulates the received signal to extract an information signal.
[0060]
As described above, according to the present embodiment, equipment for detecting the position of a terminal can be used for transmitting an information signal from a base station to the terminal.
[0061]
The present invention is not limited to the first to third embodiments.
[0062]
For example, in the first embodiment, a base station 47 shown in FIG. In FIG. 10, the base station 47 has a substantially conical wide-angle lens 47a provided with a light source 47b at the apex. On the bottom surface of the wide-angle lens 47a, a scanning device 47c capable of scanning an electromagnetic wave transmission region by switching or scanning of a liquid crystal shutter, a MEMS optical switch, a galvano scanner, or the like is arranged on the entire surface. A condensing lens 47d and a light receiving element 47e are arranged in this order at a stage subsequent to the scanning device 47c. The base station 47 can recognize which position is scanning and receiving the reflected wave by using the combination of the scanning device 47c and the light receiving element 47e. Thereby, the incident direction of the reflected wave can be known, and the rotation angle θ and the elevation angle φ of the reflection source terminal can be obtained. In FIG. 10, the distance measurement unit, the direction measurement unit, and the terminal determination unit are omitted.
[0063]
In addition, it is technically difficult to produce a retroreflector consisting of microspheres or CCC that is currently available, and it is technically difficult to create a reflector that returns in the completely incident direction. reflect. For this reason, the position of the light receiving element only needs to be in the vicinity of the light source, and is not limited to the positions shown in FIGS. Further, the light source and the light receiving element need not be integrated.
[0064]
Further, the wide-angle lens and the condenser lens help efficient collection of the electromagnetic wave and can be omitted. Further, in the above embodiment, a wide-angle lens or a condenser lens is adopted as an easy-to-understand example, but for the purpose of focusing, the optical system should be appropriately designed in consideration of the number of parts, cost, and the like, Other lenses, combination lenses, and the like may be arranged at appropriate positions.
[0065]
Further, the rules assigned to each terminal are not limited to those in the above embodiment, and any rules may be used as long as the terminal at the reflection source can be determined. For example, as a rule, a change pattern of the reflection intensity is assigned to each terminal, a change pattern of the intensity of the reflected wave received at the base station is detected, and based on the detected change pattern and the change pattern assigned to each terminal. The terminal of the reflection source may be determined by the above.
[0066]
The assignment of the rule to each terminal may be performed by any method, may be performed by a device other than the server 1, or may be previously allocated to each terminal.
[0067]
In addition, the terminal is not limited to the wireless communication terminal as in the above embodiment, and may be a simple positioning terminal.
[0068]
Further, the electromagnetic wave emitted from the base station is not limited to a light wave, and may be another electromagnetic wave such as a microwave.
[0069]
【The invention's effect】
According to the present invention, while measuring the position of the terminal using the reflection of the electromagnetic wave, at the terminal, the intensity of the reflected wave is changed according to the rule assigned for discrimination with other terminals, at the base station, Since the terminal of the reflection source is determined based on the received reflected wave and the above rule, it is possible to detect which terminal is present at which position with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an overall configuration of an information providing system according to a first embodiment.
FIG. 2 is a schematic diagram illustrating an overall configuration of a positioning system according to the first embodiment.
FIG. 3 is a schematic diagram showing a configuration of a base station 4.
FIG. 4 is a schematic diagram showing a configuration of a terminal 2.
FIG. 5 is a diagram showing an example of time slot allocation.
FIG. 6 is a schematic diagram illustrating an overall configuration of a positioning system according to a second embodiment.
FIG. 7 is a schematic diagram showing a configuration of a base station 43.
FIG. 8 is a schematic diagram illustrating a configuration of a base station according to a third embodiment.
FIG. 9 is a schematic diagram illustrating a configuration of a terminal according to a third embodiment.
FIG. 10 is a schematic diagram showing another configuration example of the base station.
[Explanation of symbols]
1 server
2, 21, 23, 24 terminals
2a, 24a housing
2b, 24b reflector
2c, 24c Intensity variable section
2d, 24d intensity control unit
24e electromagnetic wave receiving unit
24f demodulation unit
3 access point (AP)
4, 41, 42, 46 base stations
4a, 46a Wide-angle lens
4b, 46b light source
4c, 46c light receiving element array
4d, 46d Distance measurement unit
4e, 46e Direction measurement unit
4f, 46f Terminal discriminator
43-45 base station
43a Wide-angle lens
43b light source
43c condenser lens
43d light receiving element
43e Distance measuring unit
43f terminal discriminator
47 base stations
47a wide-angle lens
47b light source
47c scanning device
47d condenser lens
47e light receiving element

Claims (14)

Comprising one or more base stations and one or more terminals,
Each of the terminals,
Reflection means for reflecting electromagnetic waves,
Having intensity control means for changing the intensity of the reflected wave by the reflection means according to rules assigned for discrimination with other terminals,
Each said base station,
Emission means for emitting electromagnetic waves,
Receiving means for receiving the reflected wave reflected by the reflecting means the electromagnetic wave emitted by the emitting means,
Distance measuring means for measuring the distance to the terminal based on the time difference between the emission of the electromagnetic wave and the reception of the reflected wave,
Terminal determining means for determining the terminal of the reflection source based on the reception result by the receiving means and the rules assigned to each terminal,
A positioning system, wherein a position of each of the terminals is detected using a measurement result of the distance measurement unit and a determination result of the terminal determination unit. The base station further includes a direction measurement unit that measures a direction of the terminal based on an incident direction of the reflected wave received by the reception unit,
The positioning system according to claim 1, wherein the position of each terminal is detected by further using a measurement result of the direction measuring unit. 3. The positioning system according to claim 1, wherein a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity are assigned to each terminal as the rule. The positioning system according to claim 1, wherein the reflection unit reflects the electromagnetic wave back and forth in an incident direction of the electromagnetic wave. The emission unit emits an electromagnetic wave modulated by a signal,
The terminal according to claim 1, further comprising: an electromagnetic wave receiving unit that receives the electromagnetic wave from the emission unit; and a demodulation unit that demodulates the electromagnetic wave received by the electromagnetic wave receiving unit and extracts the signal. 5. The positioning system according to any one of 4. Reflecting means for reflecting electromagnetic waves emitted from the base station to detect the position of one or more terminals,
A terminal for controlling the intensity of the reflected wave by the reflection unit in accordance with a rule assigned to distinguish the terminal from another terminal. The terminal according to claim 6, wherein a time slot for increasing the reflection intensity and a time slot for decreasing the reflection intensity are assigned as the rule. The terminal according to claim 6, wherein the reflection unit reflects the electromagnetic wave back and forth in an incident direction of the electromagnetic wave. An electromagnetic wave receiving means for receiving an electromagnetic wave modulated by a signal and emitted from the base station, and a demodulating means for demodulating the electromagnetic wave received by the electromagnetic wave receiving means and extracting the signal, further comprising: The terminal according to any one of claims 6 to 8. A base station that measures the location of one or more terminals,
Emission means for emitting electromagnetic waves,
Receiving means for receiving a reflected wave having an intensity according to a rule assigned to each terminal, wherein the electromagnetic wave emitted by the emitting means is reflected at the terminal,
Distance measuring means for measuring the distance to the terminal based on the time difference between the emission of the electromagnetic wave and the reception of the reflected wave,
Terminal determining means for determining the terminal of the reflection source based on the reception result by the receiving means and the rules assigned to each terminal,
A base station comprising: The base station according to claim 10, further comprising a direction measurement unit that measures a direction of the terminal based on an incident direction of the reflected wave received by the reception unit. 12. The base station according to claim 10, wherein a time slot for increasing reflection intensity and a time slot for reducing reflection intensity are assigned to each terminal as the rule. The base station according to claim 10, wherein the emission unit emits an electromagnetic wave modulated by a signal. A positioning system according to any one of claims 1 to 5,
Information providing means for providing information corresponding to the position of the terminal detected by the positioning system to the terminal by wireless communication,
An information providing system comprising:

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