JP2009250661A - Mobile station condition detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To estimate the condition of an object in which a mobile station is installed. <P>SOLUTION: A mobile station tag T includes a tag antenna 32 of which the polarization direction is fixed. A fixed station reader R includes a reader antenna 12 which can generate two polarization planes orthogonal to each other, an arrival time detection section 19 for detecting the reception time of a radio signal, and an RSSI section 17 for detecting reception signal intensity in the two polarization directions, respectively, of the reader antenna 12. A management server S detects the distance from the mobile station tag T to the fixed station reader R on the basis of the reception time detected by the arrival time detection section 19, detects the attitude of the mobile station tag T on the basis of the reception signal intensity in the two polarization directions detected by the RSSI section 17, and determines the condition of the mobile station tag T in accordance with the detection results of the distance and attitude. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a mobile station state detection system that detects the state of a mobile station based on a result of wireless communication performed between the mobile station and a base station.

  For example, Patent Document 1 discloses that a mobile station having a wireless communication function is attached to an installation target such as a moving article and the orientation and orientation of the installation target are detected based on a wireless communication result from the fixed side with respect to the mobile station. The described technology has already been proposed.

  In this prior art, a plurality of RFID circuit elements (mobile stations) are provided in a predetermined arrangement manner for an installation object such as a luggage or a ball. Based on the result of communication with the plurality of RFID tag circuit elements via the antenna, the CPU of the control device determines the posture of the load, ball, etc. (whether it is upright, lying down, rotating, etc.) It comes to detect.

JP 2007-80102 A

  In the above prior art, it is possible to detect what posture the installation target of the mobile station is. However, it has not been known at which position the installation target is in the posture (for example, within a wide area). That is, it is difficult to detect both the posture and the position of the installation target, and thus there is a problem that it is difficult to estimate an accurate state of the installation target.

  An object of the present invention is to provide a mobile station state detection system that can estimate the state of an installation target by detecting both the posture and position of the installation target.

  In order to achieve the above object, a first invention provides a mobile station capable of moving within a predetermined movable area, a base station fixedly located at a known position, and a base station transmitted from the mobile station. A mobile station state detection system comprising: a state determination unit for determining the state of the mobile station based on a received radio signal, wherein the mobile station includes a transmission antenna unit whose polarization plane is a fixed linear polarization; A first transmission unit that transmits a radio signal via the transmission antenna means, and a first reception unit that receives the radio signal, and the base station transmits a second transmission unit that transmits the radio signal to each other. Receiving antenna means capable of generating two intersecting planes of polarization, a second receiving section for receiving a radio signal via the receiving antenna means, and an arrival time for detecting the arrival time of the radio signal received by the second receiving section A detection unit and the reception receiver; Strength detecting means for detecting the received signal strength at the receiving section in the two polarization planes generated by the tenor means, respectively, and the state determining means is detected by the arrival time detecting section of the base station Based on the arrival time, distance detection means for performing distance detection processing from the mobile station to the base station, and based on the magnitude of the received signal strength at the two polarization planes detected by the intensity detection means, And a posture detection means for performing a posture detection process of the mobile station, wherein the mobile station state is determined according to the detection result of the distance detection means and the detection result of the posture detection means.

  When a radio signal is transmitted from the transmitting antenna means of the mobile station, the radio signal is received by the second receiver of the base station, and the arrival time of the radio signal at this time is detected by the arrival time detector. As a result, when the clocks of the mobile station and the base station are not synchronized but a plurality of base stations perform the clock synchronization (so-called TDOA method), the comparison of the reception times of the respective base stations for the same radio signal (in other words, paraphrase) Distance detection processing can be performed by the distance detection means of the state determination means. When performing clock synchronization between the mobile station and the base station (so-called TOA method), the arrival time (propagation time) from the mobile station to the base station is calculated from the transmission time of the mobile station and the reception time of the base station, Based on this, distance detection processing can be performed by the distance detection means of the state determination means.

  Here, in radio signal transmission / reception in wireless communication, the received signal strength on the receiving side increases as the directions of the polarization planes on the transmitting side and the receiving side match (under the same transmission strength conditions). As the directions of the polarization planes on the receiving side and the receiving side become inconsistent (shift), the received signal strength on the receiving side decreases. In the first invention of the present application, while the plane of polarization of the transmitting antenna means of the mobile station is a fixed linearly polarized wave, the receiving antenna means of the base station can generate two planes of polarization that intersect each other. The received signal intensity at each polarization plane is detected by the intensity detecting means. As a result, if the received signal intensity at one polarization plane of the receiving antenna means is larger than the received signal intensity at the other intersecting polarization plane, the direction of the polarization plane of the transmitting antenna means is one of the receiving antenna means. It is estimated that the direction is close to the plane of polarization. Since the plane of polarization of the transmitting antenna means is fixed in the mobile station as described above, the estimated direction of the plane of polarization of the transmitting antenna means should correspond one-to-one with the attitude of the mobile station itself. is there. Therefore, in the first invention of the present application, the attitude detection means of the state determination means is a mobile station (in other words, depending on the magnitude of the received signal intensity in the two polarization planes (in which polarization plane the received signal intensity was high). If it is an installation target, the same applies below).

  As described above, the position detection unit can detect the position of the mobile station (distance detection from the base station to the mobile station), and the attitude detection unit can detect the attitude of the mobile station. As a result, a mobile station is provided at an appropriate part of a predetermined installation target (human or object) to estimate the state of the installation target (human seating / lying down, object erecting or rollover, etc.) Is possible.

  A second invention is the mobile station according to the first invention, wherein the base station is provided with three or more base stations, and the distance detecting means is detected by the arrival time detecting unit of each of the three or more base stations. Is a position determination unit that determines the position of the mobile station based on the arrival time of the mobile station, and the state determination unit performs the position detection process of the mobile station by the posture detection unit and the position determination by the position determination unit. It is characterized by being performed simultaneously.

  Since the position of the mobile station can be accurately determined by the position determination means based on the detection results at three or more base stations, it is possible to accurately estimate the state of the installation target together with the attitude detected by the attitude detection means. Become.

  According to a third aspect, in the second aspect, for each base station constituting the three or more base stations, a magnitude comparison result of the received signal strengths at the two polarization planes at the strength detecting means is acquired. Receiving signal strength acquisition means, wherein the attitude detection means determines the attitude of the mobile station based on the magnitude comparison result for each base station acquired by the reception signal strength acquisition means .

  When multiple base stations are provided, the magnitude of the received signal strength at the two planes of polarization at each base station may not be exactly the same at all stations, or the base station may be affected by multipath. Different results can occur. Accordingly, in the third invention of the present application, the received signal strength obtaining means obtains the magnitude result of the received signal strength in the two polarization planes for each base station (assuming the existence of such differences in the plurality of base stations), Based on the magnitude comparison results for each base station obtained by collecting them, the attitude detection means detects the attitude of the mobile station. As a result, it is possible to select an appropriate one from among the above-mentioned varied received signal strength magnitude comparison results, or to exclude the magnitude comparison results at the base station affected by the multipath. Accurate posture detection can be performed.

  In a fourth aspect based on the third aspect, the posture detection means is configured to detect at least one of the magnitudes in accordance with a predetermined priority when the magnitude comparison results in the three or more base stations do not match in all stations. A comparison result is selected, and the attitude of the mobile station is determined according to the selected size comparison result.

  As a result, even if the magnitudes of the received signal strengths at the two polarization planes at each base station are not exactly the same at all stations and vary, the received signal strengths are set according to a predetermined priority set in advance. By selecting the size comparison result and performing posture detection using the result, it is possible to reliably perform highly accurate posture detection.

  According to a fifth aspect of the present invention based on the fourth aspect of the invention, the posture detection means is in accordance with the predetermined priority determined by the position of the mobile station and the position of each base station determined by the position determination means. The at least one magnitude comparison result is selected, and the attitude of the mobile station is determined according to the selected magnitude comparison result.

  The transmitting antenna means of the mobile station has a specific directivity depending on the antenna type (for example, in the case of a dipole antenna, it has a donut-shaped directivity). Therefore, depending on the mode (shape) of directivity, the base station at a certain position favorably corresponds to the attitude of the mobile station that the received signal strength comparison result of the two polarization planes originally wants to detect, In the base station at another position, the magnitude comparison result of the received signal strengths at the two polarization planes may not correspond very well to the attitude of the mobile station to be originally detected. Accordingly, in the fifth invention of the present application, a predetermined priority is determined in accordance with the position of the mobile station and each base station, and the magnitude comparison result of the received signal strength is selected in accordance with the priority to perform posture detection. . Thereby, it is possible to reliably perform posture detection with high accuracy by using the magnitude comparison result at the optimum base station.

  In a sixth aspect based on any one of the second to fifth aspects, the base station includes polarization plane control means for switching and controlling the reception antenna means to the two polarization planes, and the intensity detection means is The received signal strength at the receiving unit in each of the two polarization planes switched by the polarization plane control means is detected.

  The polarization plane control means can switch the receiving antenna means to two polarization planes intersecting each other. Each time the plane is switched to two planes of polarization that intersect each other, the received signal intensity in each plane of polarization is detected by the intensity detector. As a result, the direction of the polarization plane of the transmission antenna means can be estimated based on the magnitude of the detected intensity in relation to the polarization plane of the reception antenna means.

  According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the arrival time detection unit of the base station transmits the radio wave for distance detection transmitted from the first transmission unit and received by the second reception unit. The position determination unit of the state determination unit detects the arrival time of the signal, performs the position determination based on the arrival time detected by the arrival time detection unit based on the distance detection radio signal, and the base station The intensity detecting means is configured to transmit a polarization plane search radio signal transmitted from the first transmitter after the distance detection radio signal is transmitted via the switched two polarization planes. Respectively, and the attitude detection means of the state determination means is based on the magnitude of the received signal intensity detected by the intensity detection means based on the polarization plane search radio signal, Said figure And performing detection processing.

  If the mobile station is moving, the posture is constantly changed by the moving operation, and it is highly likely that it is difficult to detect a static posture. Therefore, in the third invention of the present application, first, a distance detection radio signal is transmitted from the first transmission unit, position determination is performed by the position determination means based on the arrival time, and then the polarization plane search radio signal is first transmitted. Attitude detection processing is performed by the attitude detection means based on the received signal strength transmitted from the transmission unit. By dividing the processing into two parts before and after in this way, when it is detected that the position changes in time by the first position determination, that is, the mobile station is moving, the radio wave for searching for the polarization plane is detected. It is possible to prevent the posture detection process from being performed without transmitting a signal. As a result, it is possible to prevent unnecessary posture detection processing and to stabilize control and improve communication efficiency.

  In an eighth aspect based on the seventh aspect, the base station transmits the distance detection transmission request signal for requesting the distance detection radio signal to the first transmitter of the mobile station, and then moves the mobile station. And a transmission control means for controlling the second transmission unit so as to transmit the polarization plane search transmission request signal for requesting the polarization plane search radio signal to the first transmission unit of a station. To do.

  A distance detection transmission request signal is transmitted from the second transmission unit of the base station, and a distance detection radio signal is transmitted from the first transmission unit of the mobile station in accordance with the transmission request signal. Similarly, a transmission request signal for polarization plane search is transmitted from the second transmission unit of the base station, and a radio wave signal for polarization plane search is transmitted from the first transmission unit of the mobile station in response to the transmission request signal for polarization detection. Do. In this way, by transmitting a radio signal from the mobile station in response to a request from the base station, communication can be performed smoothly and efficiently while eliminating waste compared to the case of constantly transmitting a radio signal from the base station. It can be carried out.

  A ninth invention is based on the position determination result by the position determination means after the transmission of the distance detection transmission request signal from the second transmission unit based on the control of the transmission control means in the eighth invention. A stationary determination unit configured to determine whether or not the mobile station is in a stationary state, and the transmission control unit is configured to search for the polarization plane when the stationary determination unit determines that the mobile station is in a stationary state. The second transmission unit is controlled to transmit a transmission request signal.

  If it is detected by the initial position determination that the mobile station is moving, the determination of the stationary determination means is not satisfied, the radio wave signal for searching the polarization plane is not transmitted, and the attitude detection process is not performed. As a result, it is possible to reliably prevent unnecessary posture detection processing, and to stabilize control and improve communication efficiency.

  In a tenth aspect of the present invention based on any one of the second to ninth aspects, the receiving antenna means of the base station includes two receiving antennas arranged so that directions of polarization planes are orthogonal to each other. The wavefront control means includes switching means for selectively connecting the two reception antennas and the second reception unit.

  One receiving antenna having a direction of polarization plane and another receiving antenna having a direction of polarization plane orthogonal to the antenna are prepared, and these are selectively switched to obtain a second receiving unit Connecting. Thereby, switching of two orthogonal polarization planes in the receiving antenna means can be realized. Further, since simple antenna switching is sufficient, control can be simplified as compared with the case where the polarization plane direction of one antenna is controlled.

  An eleventh aspect of the invention is any one of the second to ninth aspects, wherein the receiving antenna means of the base station is one receiving antenna capable of switching the direction of the polarization plane to two directions orthogonal to each other, The polarization plane control means switches the polarization plane of the one receiving antenna to the two orthogonal polarization planes, respectively.

  By switching the direction of the polarization plane of one receiving antenna, switching between two orthogonal polarization planes in the receiving antenna means can be realized. In addition, as compared with the case where two receiving antennas are switched and connected to the second receiving unit, one antenna is sufficient, so that the number of components of the base station can be reduced and downsizing is possible.

  According to a twelfth aspect of the present invention, in the tenth or eleventh aspect of the present invention, the apparatus includes a notification signal generation unit that outputs a notification signal for performing a corresponding notification according to a posture detection result in the posture detection unit of the state determination unit. It is characterized by.

  As a result, for example, when the state of the mobile station shows an abnormal behavior (not assumed), it is possible to immediately notify the administrator or the like to that effect.

  In a thirteenth aspect based on any one of the tenth to twelfth aspects, the state determination unit is configured to determine at least the determination result of the position determination unit, the detection result of the posture detection unit, and time information. The mobile station state is determined.

  This makes it possible to manage the state of the mobile station in association with the flow of time (morning or afternoon, or other specific time, date, etc.).

  In a fourteenth aspect based on the thirteenth aspect, the state determination means determines the state of the mobile station based on the movement amount of the mobile station, which is calculated based on the determination result of the position determination means and the time information. It is characterized by performing.

  This makes it possible to manage the state of the mobile station in association with the amount of movement and the movement speed. In addition, for example, when the mobile station's moving amount or moving speed shows an abnormal behavior that deviates from a predetermined range (assumed), it is possible to immediately notify the administrator or the like to that effect. It becomes.

  In a fifteenth aspect based on the thirteenth or fourteenth aspect, the state determination means determines the state of the mobile station according to movement pattern information set in advance or movement history information detected and accumulated in advance. It is characterized by.

  As a result, the state of the mobile station can be managed in association with the preset movement pattern and the accumulated movement history. For example, when the behavior of the mobile station deviates significantly from the movement pattern or movement history, it is possible to immediately notify the administrator or the like to that effect.

  In a sixteenth aspect based on any one of the thirteenth to fifteenth aspects, the state determination means determines the state of the mobile station in accordance with predetermined movement schedule information or attitude schedule information according to the time information. It is characterized by that.

  As a result, the state of the mobile station can be managed in association with a predetermined movement schedule and attitude schedule. If the movement or attitude of the mobile station is different from the schedule, it is possible to immediately notify the administrator or the like to that effect.

  In a seventeenth aspect based on any one of the thirteenth to sixteenth aspects, the state determination unit includes a determination result of the position determination unit, a detection result of the posture detection unit, and map information of the predetermined movable region. Based on the above, the mobile station status is determined.

  By making a decision with reference to the map information, it is possible to detect where the mobile station is located on the map and what attitude the mobile station is at that location. It is possible to correctly determine the position / posture state (for example, it is possible to determine whether the person is sleeping in the bed but lying down in the toilet even in the same landscape orientation).

  According to the present invention, the state of the installation target can be estimated by detecting both the posture and the position of the installation target.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a case where distance detection is performed by the above-described TDOA method will be described as an example.

  FIG. 1 is an explanatory diagram schematically showing an overall configuration of an inpatient management system, which is an embodiment of a mobile station state detection system of the present invention.

  In FIG. 1, this example shows a case where the in-patient management system 1 of the present embodiment is applied to the entire floor of a hospital ward (a range in which the patient M can normally move). A hospital room, a restroom, a rest room, an examination room, a dining room, and a corridor connecting the plurality of rooms are management target areas (predetermined movable areas). Separately from these, a management room where an operator in charge of management (not shown, hereinafter referred to as a manager) stands by is provided on the same floor. A specific patient M (one person in this example) assigned with one of the beds installed in the hospital room is set as a management target of the inpatient management system 1.

  The inpatient management system 1 of the present embodiment includes a mobile station tag (mobile station) T possessed by a patient M to be managed, and a plurality (not shown) installed in each room serving as the management target area on the floor. In the example, five) fixed station readers (base stations) R1, R2, R3, R4, and R5, and the management installed in the management room and connected to each of the fixed station readers R1 to R5 via the communication network NW. Server S.

  Each fixed station reader R1 to R5 is installed on, for example, a wall surface of each room and has the same configuration. And each fixed station reader | leader R1-R5 can transmit / receive information via radio | wireless communication now with respect to the mobile station tag T which moves with the patient M within the management object area | region (it mentions later for details).

  The management server S stores map information on the floor and schedule information of hospitalized patients. Then, the management server S monitors (detects) the position of the mobile station tag T in the floor (that is, the position of the patient M) based on the distance to the mobile station tag T detected by each of the fixed station readers R1 to R5. (For example, every predetermined time). The management server S also monitors the posture of the mobile station tag T (that is, the posture of the body of the patient M) detected by each of the fixed station readers R1 to R5 (as necessary). And the management server S performs the alerting | reporting process according to those monitoring results (it mentions later in detail). For example, a planar coordinate system is set in the management target area, and the coordinate area occupied by each room and the installation positions of the fixed station readers R1 to R5 are stored in the management server S as map information as shown in FIG. ing.

  FIG. 2 is a functional block diagram illustrating a functional configuration of the inpatient management system 1 according to the present embodiment. Note that only one fixed station reader is shown in order to avoid the complexity of illustration.

  In FIG. 2, as described above, the inpatient management system 1 includes the mobile station tag T possessed by the patient M, the plurality of fixed station readers R1 to R5 that perform wireless communication with the mobile station tag T, and these The management server S is connected to the fixed station readers R1 to R5 via an appropriate communication network NW.

  The fixed station readers R1 to R5 (hereinafter simply referred to as “fixed station reader R” when referring to a single unit) have a reader body 11 and a reader antenna (one receiving antenna, receiving antenna means) 12. Yes.

  The reader main body 11 includes a horizontal polarization control unit 13, a vertical polarization control unit 14, a polarization synthesis unit 15, a radio unit (second transmission unit and second reception unit) 16, and an RSSI unit (intensity detection). Means) 17, network communication control unit 18, clock unit 19 </ b> A, arrival time detection unit 19, and control unit (polarization plane control unit, transmission control unit) 20.

  The horizontal polarization control unit 13 and the vertical polarization control unit 14 respectively control the horizontal polarization component and the vertical polarization component of the radio wave signal transmitted and received by the reader antenna 12. The polarization beam combiner 15 combines the received signals from the horizontal polarization controller 13 and the vertical polarization controller 14 into one (or divides one transmission signal into each polarization component). The wireless unit 16 performs wireless functions such as modulation, demodulation, and amplification for transmitting and receiving radio signals. The RSSI unit 17 detects the signal strength of the received signal.

  The network communication control unit 18 controls transmission / reception of control signals and information signals with the management server S via the communication network NW. The clock unit 19A has a function of outputting the current time (time information), and the clock units 19A of all the fixed station readers R1 to R5 can mutually adjust the time by a known appropriate method. it can. In the present embodiment, a wired network using a cable or the like is assumed for the communication network NW. However, the present invention is not limited to this, and a wireless network may be used.

  The control unit 20 includes the horizontal polarization control unit 13, the vertical polarization control unit 14, the polarization synthesis unit 15, the radio unit 16, the RSSI unit 17, the network communication control unit 18, the arrival time detection unit 19, and the clock unit 19A. The operation of the entire fixed station reader R including That is, the control unit 20 performs signal processing according to a program stored in advance in the ROM while using the temporary storage function of the RAM. Specifically, the control unit 20 receives an input of a detection processing execution command from the management server S, performs detection processing of the mobile station tag T by wireless communication via the reader antenna 12, and transmits the detection result to the above communication. The data is output to the management server S via the network NW.

  In this example, the reader antenna 12 is constituted by a substantially square planar antenna (so-called patch antenna). The reader antenna 12 is erected in such a posture that the surface direction of the substantially square shape is perpendicular to the installation space of the fixed station reader R. In the vicinity of the center position of the lower side of the substantially square of the reader antenna 12, a feed point Pv for vertical polarization connected to the vertical polarization control unit 14 is provided. A horizontal polarization feed point Ph connected to the horizontal polarization control unit 13 is provided in the vicinity of the center position of one side of the substantially square of the reader antenna 12. Then, when high-frequency power is supplied from the vertical polarization control unit 14 and the horizontal polarization control unit 13 to the feed points Pv and Ph of the reader antenna 12, radio wave signals of the corresponding polarization direction components are generated, It is transmitted from the reader antenna 12. Conversely, when the reader antenna 12 receives a radio signal, each polarization direction component of the received radio signal is input to the corresponding feed points Pv and Ph, and the vertical polarization control unit 14 and the horizontal polarization control. Is output to the unit 13.

  The management server S includes a CPU (central processing unit) 21, a memory 22, an operation unit 23, a display unit 24, a mass storage device 25, and a network communication control unit 26.

  The memory 22 is composed of, for example, a RAM or a ROM. Instructions and information from the administrator are input to the operation unit 23. Various information and messages are displayed on the display unit 24. The large-capacity storage device 25 is composed of a hard disk device, and functions as a database for storing various types of information related to floor map information, patient M, and the like. The network communication control unit 26 controls the exchange of control signals and information signals with the fixed station readers R1 to R5 via the communication network NW.

  The mobile station tag T has an IC circuit unit 31 and a tag antenna (transmission antenna means) 32. The clock unit 35 will be described later.

  The IC circuit unit 31 includes a radio unit (first transmission unit, first reception unit) 33 that implements radio functions such as modulation, demodulation, and amplification for transmitting and receiving radio signals, and a mobile station tag including the radio unit 33 And a control unit 34 that controls the operation of the entire T.

  The tag antenna 32 is composed of, for example, a linear antenna (so-called dipole antenna). The tag antenna 32 is, for example, possessed (fixed) so as to maintain an arrangement relationship that is always parallel to the longitudinal direction of the upper body (spine) of the patient M carrying the mobile station tag T (see FIG. 5 described later). ). A feeding point Pc is provided at the center of the tag antenna 32 and is connected to the radio unit 33 of the IC circuit unit 31. When transmitting, a radio wave signal is transmitted in the polarization direction parallel to the direction of the tag antenna 32 (that is, along the polarization plane where the potential changes), and at the time of reception, the polarization direction component parallel to the direction of the tag antenna 32 is transmitted. It is designed to receive radio signals with high sensitivity.

  Note that the mobile station tag T used in this example is an active tag that is driven by a power supply (not shown in particular) provided therein. As a result, the mobile station tag T can receive a relatively weak radio signal.

  In the above, the greatest feature of this embodiment is that the state of the patient M carrying the mobile station tag T is detected by detecting both the position and orientation of the mobile station tag T. Hereinafter, the details will be sequentially described.

(A) Method Principle of Mobile Station Position Detection FIG. 3 is a diagram for explaining the principle of a method for detecting the position of the mobile station tag T in the in-patient management system 1 of the present embodiment. 3 shows an example in which the position of one mobile station tag T is detected by three fixed station readers R1 to R3 in order to avoid the complexity of the illustration.

  In FIG. 3, the mobile station tag T possessed by the patient M can move to a free coordinate position within the management target area in which the plane coordinate system is set as described above, whereas the three fixed station readers R1 to R1 R3 is fixedly arranged at a known installation position in the same management target area. The fixed station readers R1 to R3 are connected to one management server S through a communication network NW so as to be able to send and receive information.

  In this configuration, the management server S determines the distance from each fixed station reader R1 to R3 to the mobile station tag T based on the reception time difference of the radio signal from the mobile station tag T at each fixed station reader R1 to R3. Measure and detect. That is, at least one of the fixed station readers R1 to R3 transmits a predetermined transmission request signal to the mobile station tag T, and the mobile station tag T fixes each radio signal (distance detection radio signal) correspondingly. Transmit to the station leaders R1 to R3. At this time, the time (arrival time) from when the mobile station tag T transmits a radio signal for distance detection until it is received by the fixed station reader R is the spatial distance between the fixed station reader R and the mobile station tag T. Proportional to distance. When the distance from each fixed station reader R to the mobile station tag T is different, the arrival time becomes a different value for each fixed station reader R and a time difference occurs. The management server S can calculate the distance between each fixed station reader R and the mobile station tag T based on the time difference.

  That is, for example, the distance between the first fixed station reader R1 located at the coordinates (x1, y1) and the mobile station tag T located at the coordinates (x, y) is r1, and the second fixed position located at the coordinates (x2, y2). The distance between the station reader R2 and the mobile station tag T is r2, and the distance between the third fixed station reader R3 located at the coordinates (x3, y3) and the mobile station tag T is r3. In addition, the error s is based on the time lag of each of the clock units 19A of the fixed station readers R1 to R3. Then, each of the first fixed station reader R1, the second fixed station reader R2, and the third fixed station reader R3 receives the reception time when the distance detection radio signal transmitted from the mobile station tag T at time T0 is received as T1, Let T2 and T3.

Under the above conditions, in FIG.
r1 + s = √ {(x−x1) ² + (y−y1) ² } (1A)
r2 + s = √ {(x−x2) ² + (y−y2) ² } (1B)
r3 + s = √ {(x−x3) ² + (y−y3) ² } (1C)
Holds.

Then, by subtracting equation (1B) from equation (1A),
| R1-r2 | = c × | T1-T2 | (1D)
Moreover, by subtracting the formula (1C) from the formula (1A),
| R1-r3 | = c × | T1-T3 | (1E)
The relationship expressed by In addition, c is a radio wave speed (light speed: about 3.0 × 10 ⁸ [m / s]).

  At this time, (the reception times T1, T2, and T3 are known as measured values), there are only three variables r1, r2, and r3. Therefore, the above two equations (1D) and (1E) are expressed by, for example, the Newton-Raphson method It is possible to specify the x and y coordinates (x, y) of the position of the mobile station tag T by solving the above. Note that more accurate position detection can be performed by providing five fixed station readers R1 to R5 as in this embodiment.

  In the above example, each of the fixed station readers R1 to R3 only detects the reception time of the radio signal and transmits it to the management server S, and the distance measurement process (from the fixed station readers R1 to R3 to the mobile station tag T). The management server S performs distance calculation and position determination), but is not limited thereto. That is, the control units 20 of the fixed station readers R1 to R3 mutually transmit / receive reception time information, and the fixed station readers R1 to R3 perform calculation of the distance to the mobile station tag T, and the calculation result ( (Distance data) may be transmitted to the management server S. In the management server S, the three distance data from each of the fixed station readers R1 to R3 are totaled, and the position of the mobile station tag T is detected (function as position determination means).

(B) Method Principle of Mobile Station Posture Detection FIGS. 4A to 4C are explanatory diagrams for explaining the method principle of detecting the posture of the mobile station tag T in the inpatient management system 1 of this embodiment. It is. In the figure, only the reader antenna 12, the horizontal polarization control unit 13, the vertical polarization control unit 14, the polarization combining unit 15, and the control unit 20 are included in the configuration of the fixed station reader R in order to avoid the complexity of the illustration. Is shown.

  4A to 4C, as described above, the mobile station tag T is fixed to be integral with the upper body of the patient M. And the longitudinal direction of the tag antenna 32 of the mobile station tag T maintains the arrangement relationship parallel to the spine of the patient M (the longitudinal direction of the upper body). As a result, as shown in FIGS. 4A and 4B, when the patient M is in an upright posture due to movement of the room or the like (or in a sitting posture on a bed, a chair, or the like). In this case, the longitudinal direction of the tag antenna 32 is substantially parallel to the vertical direction, that is, the polarization direction of the tag antenna 32 is the vertical direction. In addition, as shown in FIG. 4C, when the patient M is in a lateral posture (a state lying on the bed or the like due to some morbidity or the like, or a posture falling on the floor) The longitudinal direction of the tag antenna 32 is substantially parallel to the horizontal direction, that is, the polarization direction of the tag antenna 32 is the horizontal direction.

  In the present embodiment, the posture of the patient M is detected by detecting the polarization direction of the mobile station tag T using the above. That is, as the polarization direction of the reader antenna 12 is closer to the polarization direction of the tag antenna 32, the radio signal from the mobile station tag T can be received with higher received signal strength. As described above, the fixed station reader R can control the polarization direction of the reader antenna 12 (patch antenna) by the control unit 20 controlling the horizontal polarization control unit 13 and the vertical polarization control unit 14. . Therefore, the polarization direction of the reader antenna 12 is switched between the vertical direction and the horizontal direction, and the received signal strength of the radio signal from the mobile station tag T received by each is compared. Based on the comparison result, it is possible to compare and detect whether the longitudinal direction (posture) of the tag antenna 32 at that time is close to the vertical direction or the horizontal direction. As a result, the posture of the mobile station tag T and thus the posture of the patient M can be detected.

  For example, when the control unit 20 of the fixed station reader R activates the vertical polarization control unit 14, the polarization plane generated by the reader antenna 12 becomes a vertical polarization state. In this state, as shown in FIG. 4A, when the patient M is in an upright posture or the like (the polarization direction of the tag antenna 32 is substantially vertical), each of the fixed station reader R and the mobile station tag T The polarization directions are very close (substantially parallel). As a result, the fixed station reader R can receive the radio signal from the mobile station tag T with high received signal strength. On the other hand, when the control unit 20 of the fixed station reader R activates the horizontal polarization control unit 13, the polarization plane generated by the reader antenna 12 is in the horizontal polarization state. In this state, when the patient M is in an upright posture or the like (the polarization direction of the tag antenna 32 is substantially vertical), as shown in FIG. 4 (b), the fixed station reader R and the mobile station tag T are offset. The wave directions are greatly different (substantially orthogonal). For this reason, the fixed station reader R can receive a radio signal from the mobile station tag T only with a low received signal strength.

  Therefore, detecting that the patient M is in an upright posture or the like based on the result that a large received signal strength is obtained in the vertically polarized state and only a small received signal strength is obtained in the horizontally polarized state. Can do.

  As described above, when the patient M is in a horizontal posture or the like (the polarization direction of the tag antenna 32 is substantially horizontal), the polarization plane of the reader antenna 12 is in the horizontal polarization state as shown in FIG. The direction of polarization coincides with that of the fixed station reader R. As a result, the fixed station reader R can receive the radio signal from the mobile station tag T with high received signal strength. Conversely, when the polarization plane of the reader antenna 12 is in the vertical polarization state, the polarization direction does not coincide with that of the fixed station reader R, and the received signal intensity from the mobile station tag T becomes small (not shown).

  Therefore, detecting that the patient M is in the horizontal posture or the like based on the above result that a large received signal strength is obtained in the horizontally polarized state and only a small received signal strength is obtained in the vertically polarized state. Can do.

  Although not particularly illustrated, the control unit 20 of the fixed station reader R controls the amplitude and phase difference of the carrier wave in the horizontal polarization control unit 13 and the vertical polarization control unit 14 to thereby control the polarization direction in the reader antenna 12. Can be synthesized at any angle, or so-called circularly polarized waves can be synthesized at any angle. You may make it utilize each of these polarization directions for the attitude | position detection of the mobile station tag T as needed.

  In the above example, each fixed station reader R only detects the received signal strength of the radio signal and transmits it to the management server S, and performs attitude detection processing (the mobile station tag T by comparing the received signal strength for each polarization plane). Is detected by the management server S, but is not limited thereto. That is, each fixed station reader R transmits and receives received signal strengths in two polarization planes, performs posture detection based on the comparison (= function as posture detection means), and calculates the calculation result (distance data). You may make it transmit to the management server S. In this case, the management server S totals the attitude detection results from each of the fixed station readers R and determines the final attitude of the mobile station tag T.

  Further, when the mobile station tag T is attached to the limb of the patient M, the posture of the mobile station tag T and the posture of the patient M may be different. In order to avoid this and ensure consistency between the posture of the patient M and the posture of the mobile station tag T, for example, as shown in FIG. It may be arranged on a body portion such as a belt and fixed to the upper body with a belt 41 or the like.

  (C) Control for state detection

  6 and 7 are sequence diagrams showing an example of transmission and reception of various signals and control operations between the management server S, the fixed station readers R1 to R5, and the mobile station tag T. 6 and 7, each procedure is basically represented by a time series change from the upper side to the lower side in the drawing. As described above, signals are transmitted and received between the management server S and the fixed station readers R1 to R5 (only one of which is installed) via the communication network NW. In addition, signals are transmitted and received between the fixed station readers R1 to R5 and the mobile station tag T via wireless communication.

  First, in step SS10 shown in FIG. 6, the CPU 21 of the management server S performs each of the fixed station readers R1 to R5 (or only one specific fixed station reader R) via the network communication control unit 26. An instruction signal is output so as to transmit a radio wave transmission request for distance detection to the mobile station tag T. As a result, in step SR10, the radio unit 16 of the corresponding fixed station reader R transmits a radio wave transmission request signal (distance detection transmission request signal) to the mobile station tag T via the reader antenna 12.

  Then, the radio unit 33 of the mobile station tag T that has received this transmission request signal transmits a corresponding radio signal (distance detection radio signal) via the tag antenna 32 in step ST10. The radio unit 16 of each of the fixed station readers R1 to R5 receives a radio signal for distance detection via the reader antenna 12 in step SR20. Then, the arrival time detection unit 19 detects the reception time information at that time, and the control unit 20 outputs the reception time information to the management server S via the network communication control unit 18.

  Then, in step SS20, the CPU 21 of the management server S determines the distance / position to each mobile station tag T based on the difference in reception time (= difference in arrival time) input from each of the fixed station readers R1 to R5. calculate.

  In step ST10, a radio signal for distance detection is transmitted from the mobile station tag T in response to a transmission request from the fixed station reader R. However, the present invention is not limited to this. That is, the mobile station tag T continues to transmit a radio signal spontaneously at regular time intervals, and each fixed station reader R receives the radio signal continuously transmitted, and based on this, the management server S performs distance detection. May be.

  Next, in step SS40, the CPU 21 of the management server S calculates the position coordinates of the mobile station tag T calculated in step SS20 and the map information (in the management target area) of the floor stored in the large-capacity storage device 25 in advance. Based on the information recorded in the coordinate area and the like occupied by each room, the room (or hallway) where the patient M is located at that time is determined.

  Next, in step SS50, the CPU 21 of the management server S determines whether or not the mobile station tag T has moved greatly from the previously detected position coordinates (for example, a comparison with a threshold value set and stored in advance with respect to the movement amount). Judgment). If the mobile station tag T does not move greatly, that is, there is no movement of the patient M, the determination is not satisfied, and the routine goes to the next Step SS60.

  In step SS60, the CPU 21 of the management server S refers to a predetermined schedule table (see FIG. 8 described later) set and stored in advance for the patient M, and the room determined in step SS40 corresponds to the time point. It is determined whether or not it is included in the set destination candidate rooms (that is, whether or not the patient M is located in the room that is appropriate at that time). If the room where the patient M is located at that time is a room that is a destination candidate corresponding to that time in the schedule table, the determination is not satisfied, and the routine goes to Step SS80 in FIG. On the other hand, if the determined room is included in the destination candidate rooms, the determination is satisfied, and the routine goes to Step SS70.

  In step SS70, the CPU 21 of the management server S refers to the schedule table and determines whether or not the room in which the patient M is present at that time is a room that can take a horizontal posture. In the schedule table, if there is no possibility that the patient M will be in the horizontal posture in the room in the location, the determination is not satisfied, and the routine goes to Step SS80 in FIG.

  In the determination step SS50, if the movement of the patient M is confirmed and the determination is satisfied, or in the determination step SS70, the room where the patient M is located at that time is a room that can take a horizontal posture. If it is satisfied, the process returns to step 10 of the management server S and the same control operation is repeated.

  In FIG. 7, in step SS80, the CPU 21 of the management server S sends a mobile station tag to each of the fixed station readers R1 to R5 (or only one specific fixed station reader R) via the network communication control unit 26. An instruction signal is output so as to transmit a radio wave transmission request for polarization plane search to T. As a result, in step SR30, the radio unit 16 of the corresponding fixed station reader R transmits a radio wave transmission request signal (transmission plane search transmission request signal) to the mobile station tag T via the reader antenna 12.

  And the radio | wireless part 33 of the mobile station tag T which received this transmission request signal transmits a corresponding radio wave signal (polarization plane search radio wave signal) via the tag antenna 32 in step ST20. In step SR40, the control unit 20 of each of the fixed station readers R1 to R5 causes the vertical polarization control unit 14 to place the reader antenna 12 in the vertical polarization state and receive this radio signal. The RSSI unit 17 detects the received signal strength at that time, outputs the detection result to the management server S via the network communication control unit 18, and the management server S acquires the output received signal strength (received signal strength). Acquisition means).

  Next, in step SS90, the management server S performs the polarization plane search to the mobile station tag T for each of the fixed station readers R1 to R5 (or a specific fixed station reader R) as described above. An instruction signal is output to transmit the radio wave transmission request. As a result, the corresponding fixed station reader R transmits a radio wave transmission request signal (polarization plane search transmission request signal) toward the mobile station tag T in step SR50. The mobile station tag T that has received the transmission request signal transmits a corresponding radio signal (radio wave signal for polarization plane search) in step ST30, and each fixed station reader R1 to R5 sets the reader antenna 12 (horizontal polarization) in step SR60. The radio signal is received as a horizontally polarized state (by the control unit 13). Then, the received signal strength is detected by the RSSI unit 17 and output to the management server S, and the management server S acquires the output received signal strength (received signal strength acquisition means).

  In step ST20 and step ST30, the radio wave signal for searching for the polarization plane is transmitted from the mobile station tag T in response to a transmission request from the fixed station reader R. However, the present invention is not limited to this. That is, the mobile station tag T continues to transmit a radio signal spontaneously at a fixed time interval, and each fixed station reader R receives the radio signal continuously transmitted, and based on this, the management server S searches for the polarization plane. It may be.

  Thereafter, in step SS100, the CPU 21 of the management server S receives the received signal strength in the vertically polarized state in each of the fixed station readers R1 to R5 input in step SR40 and each of the fixed station readers R1 to R1 input in step SR60. The received signal strength in the horizontally polarized state in R5 is compared. Whether or not the radio wave signal for searching the plane of polarization from the mobile station tag T at that time has a higher received signal strength in the horizontal polarization state than in the vertical polarization state (= in other words, Whether or not the posture of the mobile station tag T or the patient M is closer to the horizontal than the vertical). In this determination, first, one fixed station reader R having the maximum received signal strength as a whole may be specified, and the vertical polarization state and the horizontal polarization state of the fixed station reader R may be compared. Alternatively, the maximum value of the received signal strength in the vertical polarization state for any of the fixed station readers R1 to R5 and the received signal strength in the horizontal polarization state of any of the fixed station readers R1 to R5. The maximum value may be compared.

  Based on the comparison method as described above, if the received signal strength in the horizontally polarized state is high in the vertically polarized state, the determination is satisfied, and the posture of the mobile station tag T and the patient M is closer to the horizontal than the vertical. It moves to step SS110. In step SS110, the CPU 21 of the management server S outputs a notification signal to the display unit 24, displays that there is a high possibility that the patient M rolls over and is in an abnormal state, and notifies the administrator. Then, this flow ends.

  If the mobile station tag T and the posture of the patient M are close to vertical rather than horizontal in step SS100, the determination returns to step 10 of the management server S shown in FIG. 6 and the same control operation is repeated. .

  As described above, when it is detected that the patient M is in the horizontal posture state in an inappropriate room that is not set in the schedule table at that time (or there is no possibility that the patient M will be in the horizontal posture in the schedule table). When it is detected that the patient M is in the lateral posture state in a certain room), it is possible to notify the manager of the abnormal state in which the patient M rolls over for some pathological cause.

  FIG. 8 is an explanatory diagram showing the schedule table for managing the appropriate location of the patient M in each time segment described above.

  In FIG. 8, this schedule table is stored and held in the mass storage device 25 of the management server S. In this example, up to three destination candidates (movement schedule information) that are expected to be located every 10 minutes when the patient M is normal are set. In correspondence with each destination candidate, information on whether or not there is a possibility that the patient M may be in a lateral posture (posture schedule information) is described. For example, in the illustrated example, the patient M is scheduled to go to bed in a hospital room until 7:00, get up after 7:00, have breakfast in the cafeteria from 7:20 to 30 minutes, and 8: From 00 to 30 minutes, it is scheduled to be examined in the laboratory. The toilet is always set as the second destination candidate, and it is set as the third destination candidate on the assumption that there is a possibility that the patient M goes to the break room other than the bedtime and the examination time.

  By referring to this schedule table, the management server S does not leave the patient M staying at an inappropriate position for an unnecessary time at that time, or is not in a lateral posture at an inappropriate position. For example, it is possible to detect a possibility that an abnormal state such as the patient M is tumbling to the floor due to a pathological cause has occurred.

  In the above, step SS20 and step SS100, which are executed in FIG. 6 and FIG. 7, constitute the state determination means described in each claim. Among them, step SS20 constitutes a distance detection means and also constitutes a position determination means. Step SS100 constitutes posture detection means. Moreover, step SS110 of FIG. 7 comprises a notification signal production | generation means. Further, Step SS50 in FIG. 6 constitutes a stillness determination unit.

  In the present embodiment configured as described above, when a radio signal is transmitted from the tag antenna 32 of the mobile station tag T, the radio signal is received by the radio unit 16 of the fixed stations R1 to R5. The arrival time detector 19 detects the reception time of the radio signal. Thereby, the management server S performs position determination based on the reception time difference information of the fixed station readers R1 to R5 (step SS20).

  On the other hand, the polarization direction of the tag antenna 32 of the mobile station tag T is fixed to the tag itself, whereas the polarization directions of the reader antennas 12 of the fixed station readers R1 to R5 intersect each other (in this example, they are orthogonal). Switching between two polarization directions is possible. At the time of this switching, the received signal strength in each polarization direction is detected by the RSSI unit 17. In radio signal transmission / reception in wireless communication, the reception signal strength at the reception side increases as the polarization directions at the transmission side and the reception side coincide with each other. In accordance with the magnitude of the signal strength (in which polarization direction the received signal strength was high), the management server S performs the attitude detection process of the mobile station tag T (step SS100).

  As described above, both the position determination and posture detection of the mobile station tag T (in other words, the patient M. The same applies hereinafter) can be performed together. As a result, the accurate state of the patient M carrying the mobile station tag T can be estimated.

  In the present embodiment, in particular, a notification signal for performing a corresponding notification according to the posture detection processing result is output. Thereby, in the case where the state of the patient M shows an abnormal behavior (not supposed), the manager or the like can be notified immediately.

  In this embodiment, in particular, in addition to the detection results of the position determination and posture detection processing, the state determination of the patient M is performed using time information (for example, acquired in the clock unit 19A of the fixed reader R or the management server S). Do. Thereby, the state of the patient M carrying the mobile station tag T can be managed in association with the flow of time. Specifically, as shown in FIG. 8, the state determination of the patient M is performed with reference to a schedule table in which a predetermined schedule is described according to time information. Accordingly, the state of the patient M can be managed in association with a predetermined movement schedule (in this example, a destination candidate room) and a posture schedule (in this example, whether there is a lateral attitude corresponding to the room). As a result, when the movement and posture of the patient M carrying the mobile station tag T are different from those scheduled, it is possible to immediately notify the manager or the like to that effect.

  The schedule table includes not only the information set as standard, but also the movement pattern information of the individual patient M set in advance and the movement history information detected and accumulated in advance (the tendency to occasionally fall asleep / nap in the morning) There is a tendency to get up around 800 to 815 in early spring, etc.). As a result, it is possible to manage the state of the patient M in association with preset movement patterns specific to the individual and the accumulated movement history. For example, when the behavior of the patient M greatly deviates from these movement patterns and movement histories, it is possible to immediately notify the administrator or the like to that effect.

  Further, at this time, the state determination may be performed based on the movement amount (or movement speed) of the mobile station tag T (patient M) calculated based on the position determination result and the time information. Thereby, the state of the patient M can be managed in association with the movement amount and movement speed. Therefore, when the abnormal behavior deviates from the predetermined range that is assumed (for example, the walking distance is not unnaturally long or the moving speed is not too slow for walking) In other words, in a normal movement, the movement is too rapid and unnatural, etc.), the fact can be immediately notified to the administrator or the like. Furthermore, only when the movement amount or movement speed exceeds a predetermined threshold (preset to correspond to an abnormal operation or a predetermined attention operation), state determination or notification is performed. May be.

  In the present embodiment, in particular, the state determination of the mobile station tag T is performed with reference to the map information (see FIG. 1) stored in the mass storage device 25 of the management server S. As a result, it is possible to detect where the mobile station tag T is present on the map and in what position the mobile station tag T is located.

  Further, if the mobile station tag T is moving, the posture is constantly changed by the moving operation, and it is highly likely that it is difficult to detect a static posture. Therefore, in the present embodiment, in particular, first, a radio signal for distance detection is transmitted from the mobile station tag T (step ST10), the position is determined, and then a radio signal for searching for the polarization plane is transmitted from the mobile station tag T. (Step ST20 and Step ST30) Attitude detection processing is performed. As described above, by dividing the process into two parts, the mobile station tag T is moved by the first position determination so that the attitude detection process is not performed without transmitting the radio wave signal for searching the polarization plane. (Step SS50). As a result, it is possible to prevent unnecessary posture detection processing and to stabilize control and improve communication efficiency.

  In the present embodiment, in particular, a transmission request for a distance detection radio signal is transmitted from the fixed station reader R (step SS10), and a radio wave signal for distance detection is transmitted from the mobile station tag T in accordance with this request. Make a decision. Similarly, a transmission request for a polarization plane search radio signal is transmitted from the fixed station reader R (steps SS80 and SS90), and a radio wave signal for polarization plane search is transmitted from the mobile station tag T in accordance with this request. Attitude detection processing is performed. In this way, by transmitting a radio signal from the mobile station tag T in response to a request from the fixed station reader R, communication can be performed while reducing waste compared to the case of constantly transmitting a radio signal from the fixed station reader R. Can be carried out smoothly and efficiently.

  In the present embodiment, in particular, position determination is performed by at least three fixed station readers R1 to R5 (five in this example). Thereby, in the management server S, it is possible to sum up how far the mobile station tag T is located from each of the fixed station readers R1 to R5, and to identify the location of the mobile station tag T and perform position detection. it can. The present invention is not limited to this, and the distance detection process may be performed by, for example, only one fixed station reader R (in this case, the distance measurement process is performed not by the TDOA system but by the TOA system described later). . In this case, for example, how far the mobile station tag T is located from the fixed station reader R, that is, the mobile station tag T in a predetermined vicinity area (that is, a room where the fixed station reader R is installed). Will be detected.

  In the above embodiment, the two polarization directions orthogonal to each other are switched in one reader antenna 12. As a result, as compared with the case where a plurality of reader antennas 12 are prepared and switched, a single antenna is sufficient, so that the number of components of the fixed station reader R can be reduced and the size can be reduced. The present invention is not limited to this. That is, for example, as shown in FIG. 9 corresponding to FIG. 4, two receiving antennas 12A and 12B arranged so that the directions of the polarization planes cross each other (orthogonal in this example) are received by the fixed station reader R. You may provide as an antenna means. That is, one receiving antenna 12A whose polarization direction is oriented in a certain direction and another receiving antenna 12B whose polarization direction is oriented in a direction orthogonal to the antenna 12A are prepared, and these are selectively switched to change the radio unit. 16 is connected. Thereby, switching of two orthogonal polarization directions in the fixed station reader R can be realized (function as polarization plane control means). Since simple antenna switching is sufficient, control can be simplified as compared with the case where the polarization plane direction of one antenna is controlled as described above. Further, in this modification, an RSSI unit as strength detecting means is provided separately for each of the two receiving antennas 12A and 12B, and the received signal strength is detected simultaneously (without switching the antenna). Alternatively (a configuration in which the polarization plane control unit is omitted). In this case, the same effect as the above embodiment can be obtained.

  In the above description, the so-called TDOA method in which distance measurement processing is performed based on the reception time difference of each fixed station reader R with respect to the radio signal for distance detection from the mobile station tag T has been described. However, the present invention is not limited to this, and distance measurement processing can also be performed using the TOA method.

  FIG. 10 is an explanatory diagram for explaining the method of the distance measurement principle in the present modification that performs the TOA method, and corresponds to FIG. 3 described above. As in FIG. 3, the case where three fixed station readers R1 to R3 are used will be described as an example.

10, in the same manner as in FIG. 3, the first fixed station reader R1 located at the coordinates (x1, y1) and the mobile station tag T located at the coordinates (xt, yt) (in the case of the TOA system as described later) Includes a clock unit 35. The distance from the mobile station tag T is r2 and the coordinates (x3, y3) are the distance between the second fixed station reader R2 and the mobile station tag T located at the coordinates (x2, y2). If the distance between the third fixed station reader R3 located at) and the mobile station tag T is r3, the relationship represented by the following equation (2) is established.
(X−x1) ² + (y−y1) ² = r1 ²
(X−x2) ² + (y−y2) ² = r2 ²
(X−x3) ² + (y−y3) ² = r3 ² (2)

  By solving these three equations, the values of x and y can be calculated, and the x and y coordinates (xt, yt) of the position of the mobile station tag T can be specified.

In FIG. 2 described above, in this modification, the clock unit 35 of the mobile station tag T is indispensable. The clock unit 35 of the mobile station tag T and the clock unit 19A of each of the fixed station readers R1 to R5 are timed by a predetermined method. In this modification, the arrival time detector 19 (see FIG. 2) provided in the fixed station readers R1 to R5 transmits the time when the distance detection radio signal is transmitted from the mobile station tag T and the distance detection radio wave. The time at which the signal was received by the fixed station readers R1 to R5 is detected. The transmission time of the distance detection radio signal from the mobile station tag T is, for example, restored by the baseband signal generation / restoration unit (not shown) provided in the control unit 20 to the baseband signal included in the distance detection radio signal. Can be obtained by doing. For example, the mobile station tag T and each of the fixed station readers R1 to R5 are preset in advance to transmit from the mobile station tag T at a predetermined time interval, and based on this, the fixed station readers R1 to R5 side Other methods such as determining the transmission time from the mobile station tag T may be used. The transmission time of the mobile station tag T thus obtained and the reception times of the fixed station readers R1 to R5 are output to the management server S. The management server S obtains the propagation time of the distance detection radio signal from the difference between the transmission time and the reception time. Then, by multiplying this propagation time by the radio wave velocity (light velocity) c (= 3.0 × 10 ⁸ [m / s]), the distance between the mobile station tag T and each of the fixed station readers R1 to R5 (the above r1) , R2, r3, etc.) can be calculated. As described above, the calculation of the propagation time and the distance calculation may be executed on the fixed station readers R1 to R5 side.

  Also by this modification, the same effect as the above-mentioned embodiment and each modification is acquired.

  Although not mentioned above, for example, when a plurality of fixed station readers R1 to R5 are provided as described above, the magnitude of the received signal strength at each fixed station reader R (in the above example, in the horizontally polarized state) There is a possibility that the magnitude relationship between the value and the value in the vertical polarization state does not completely coincide with all the fixed station readers R and varies. In some cases, the intensity in a certain polarization direction is lowered around a specific fixed station reader R due to the influence of multipath. Accordingly, in response to this, the received signal strength (large or small) results in the horizontal polarization state / vertical polarization state for each fixed station reader R are acquired and aggregated in the above step SR40 and step SR60. The attitude of the mobile station tag T may be detected in consideration of the size comparison result for each fixed station reader R.

  At this time, by setting the priority of the fixed station reader R according to appropriate regularity from the magnitude comparison results of the different received signal strengths included in the five fixed station readers R1 to R5, the received signal strength varies as described above. Thus, it is possible to select an appropriate one from the above-mentioned magnitude comparison results, or to exclude the magnitude comparison results at the base station affected by the multipath. As an example of the priority setting, there is a method in which, for example, a majority decision is made, and the received signal strength comparison result with the largest number of corresponding fixed station readers R is given priority.

  Alternatively, the positional relationship between the mobile station tag T and each fixed station reader R may be taken into consideration. That is, the antenna of the mobile station tag T has a specific directivity depending on the type of antenna (for example, in the case of the above-mentioned dipole antenna, it has a donut-shaped directivity). For this reason, depending on the mode (shape) of the directivity, the fixed station reader R at a certain position has the result of comparing the magnitudes of the received signal strengths in the horizontal polarization state and the vertical polarization state of the mobile station tag T to be originally detected. Although it corresponds to the posture well, there is a possibility that the result of the comparison of the received signal strengths does not correspond very well to the posture of the mobile station tag T to be originally detected in the fixed station reader R at another position. Therefore, a predetermined priority is determined in advance in accordance with the positional relationship between the mobile station tag T and each fixed station reader R, and different received signals included in the five fixed station readers R1 to R5 according to the priority. An appropriate one is selected from the magnitude comparison results, and posture detection is performed based on the result.

  As described above, it is possible to reliably perform highly accurate attitude detection using the magnitude comparison result of the received signal strength at the optimum fixed station reader R.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

It is explanatory drawing which shows roughly the whole structure of the inpatient management system which is one Embodiment of the state detection system of the mobile station of this invention. It is a functional block diagram showing the functional structure of an inpatient management system. It is explanatory drawing for demonstrating the technique principle of the position detection of a mobile station tag. It is explanatory drawing for demonstrating the technique principle of the attitude | position detection of a mobile station tag. It is a figure which shows an example of the attachment structure of the mobile station tag with respect to a hospitalized patient's body. It is a sequence diagram showing an example of transmission and reception of various signals transmitted and received between a management server, a fixed station reader, and a mobile station tag, and a control operation. It is a sequence diagram showing an example of transmission and reception of various signals transmitted and received between a management server, a fixed station reader, and a mobile station tag, and a control operation. It is a figure which represents notionally the schedule table which manages the appropriate location of the inpatient in each time division. It is a figure which shows the case where the reader antenna of a fixed station reader is comprised with two independent antennas where the polarization directions are orthogonal, respectively. It is explanatory drawing for demonstrating the method principle of the position detection of the mobile station tag in the modification which performs a TOA system.

Explanation of symbols

1 Inpatient management system (mobile station status detection system)
12 Reader antenna (one receiving antenna, receiving antenna means)
12A, 12B Receiving antenna (receiving antenna means)
13 Horizontal polarization control unit 14 Vertical polarization control unit 15 Polarization combining unit 16 Radio unit (second transmission unit, second reception unit)
17 RSSI part (strength detection means)
18 Network communication control unit 19 Arrival time detection unit 19A Clock unit 20 Control unit (polarization plane control means, transmission control means)
32 Tag antenna (transmitting antenna means)
33 Radio section (first transmitter, first receiver)
T Mobile station tag (mobile station)
R, R1-5 Fixed station leader (base station)
S Management server M Patient (target for installation)

Claims (17)

A mobile station capable of moving in a predetermined movable area;
A base station fixedly located at a known location;
A state detection system for a mobile station having state determination means for determining the state of the mobile station based on a radio signal transmitted from the mobile station and received by the base station,
The mobile station
Transmitting antenna means whose polarization plane is fixed linear polarization,
A first transmitter for transmitting a radio signal via the transmitting antenna means;
A first receiver for receiving a radio signal,
The base station
A second transmitter for transmitting radio wave signals;
Receiving antenna means capable of generating two planes of polarization intersecting each other;
A second receiving unit for receiving a radio signal via the receiving antenna means;
An arrival time detector that detects an arrival time of the radio signal received by the second receiver;
Intensity detecting means for detecting the received signal intensity at the receiving unit at the two polarization planes generated by the receiving antenna means, respectively.
The state determination means includes
Based on the arrival time detected by the arrival time detection unit of the base station, distance detection means for performing distance detection processing from the mobile station to the base station;
Attitude detecting means for performing attitude detection processing of the mobile station based on the magnitude of the received signal intensity at the two polarization planes detected by the intensity detecting means;
A mobile station state detection system that performs state determination of the mobile station according to a detection result of the distance detection unit and a detection result of the attitude detection unit. Three or more base stations are arranged,
The distance detecting means includes
Position determining means for determining the position of the mobile station based on the arrival time of the mobile station detected by the arrival time detection unit of each of the three or more base stations;
The state determination means includes
The mobile station state detection system according to claim 1, wherein the mobile station posture detection process by the posture detection unit and the position determination unit by the position determination unit are performed simultaneously. Receiving signal strength acquisition means for acquiring a magnitude comparison result of the received signal strength at the two polarization planes in the strength detection means for each base station constituting the three or more base stations,
The posture detection means includes
The mobile station state detection system according to claim 2, wherein the attitude of the mobile station is determined based on the magnitude comparison result for each base station acquired by the received signal strength acquisition means. The posture detection means includes
When the magnitude comparison results in the three or more base stations do not match in all stations, select at least one magnitude comparison result according to a predetermined priority, and depending on the selected magnitude comparison result, 4. The mobile station state detection system according to claim 3, wherein the attitude of the mobile station is determined. The posture detection means includes
The at least one magnitude comparison result is selected along the predetermined priority determined by the position of the mobile station and the position of each base station determined by the position determination means, and the selected magnitude 5. The mobile station state detection system according to claim 4, wherein an attitude of the mobile station is determined according to a comparison result. The base station
Polarization plane control means for switching and controlling the reception antenna means to the two polarization planes,
The intensity detecting means includes
The state of the mobile station according to any one of claims 2 to 5, wherein reception signal strengths at the receiving unit in the two polarization planes switched by the polarization plane control unit are detected respectively. Detection system. The arrival time detector of the base station is
Detecting the arrival time of the radio signal for distance detection transmitted from the first transmitter and received by the second receiver;
The position determination means of the state determination means is
Based on the arrival time detected by the arrival time detection unit based on the distance detection radio signal, the position determination,
The intensity detecting means of the base station is
Reception when a radio wave signal for searching for a polarization plane transmitted from the first transmission unit is received by the reception unit via the switched two planes of polarization after transmission of the radio signal for distance detection Detect each signal strength,
The posture detection means of the state determination means is
The posture detection process is performed based on the magnitude of the received signal intensity detected by the intensity detection unit based on the polarization plane search radio signal. Mobile station status detection system. The base station
After transmitting a distance detection transmission request signal for requesting the distance detection radio signal to the first transmission unit of the mobile station, the polarization plane search radio signal is transmitted to the first transmission unit of the mobile station. 8. The mobile station state detection system according to claim 7, further comprising transmission control means for controlling the second transmission section so as to transmit a polarization plane search transmission request signal for requesting. After transmitting the distance detection transmission request signal from the second transmission unit based on the control of the transmission control means, it is determined whether the mobile station is in a stationary state based on the position determination result by the position determination means. Having stationary determination means to
The transmission control means includes
9. The second transmission unit is controlled to transmit the polarization plane search transmission request signal when the stationary determination unit determines that the mobile station is stationary. Mobile station status detection system. The receiving antenna means of the base station is
It has two receiving antennas arranged so that the directions of polarization planes are orthogonal to each other,
The polarization plane control means includes
The mobile station state detection system according to any one of claims 2 to 9, further comprising switching means for selectively connecting the two reception antennas to the second reception unit. The receiving antenna means of the base station is
One receiving antenna that can switch the direction of the polarization plane in two directions orthogonal to each other,
The polarization plane control means includes
The mobile station state detection system according to any one of claims 2 to 9, wherein the polarization plane of the one receiving antenna is switched to the two orthogonal polarization planes. The movement according to claim 10 or 11, further comprising notification signal generation means for outputting a notification signal for performing a corresponding notification in accordance with a posture detection result in the posture detection means of the state determination means. Station status detection system. The state determination means includes
The state determination of the mobile station is performed according to at least the determination result of the position determination unit, the detection result of the attitude detection unit, and time information. The mobile station state detection system described in the above section. The state determination means includes
The mobile station state detection according to claim 13, wherein the mobile station state is determined based on a movement amount of the mobile station calculated based on a determination result of the position determination unit and the time information. system. The state determination means includes
15. The mobile station state detection system according to claim 13 or 14, wherein the mobile station state is determined according to movement pattern information set in advance or movement history information detected and accumulated in advance. The state determination means includes
The state of the mobile station according to any one of claims 13 to 15, wherein the state of the mobile station is determined according to movement schedule information or attitude schedule information determined in advance according to the time information. Detection system. The state determination means includes
17. The state determination of the mobile station is performed based on a determination result of the position determination unit and a detection result of the attitude detection unit, and map information of the predetermined movable area. The mobile station state detection system according to claim 1.

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