JP6692472B2 - Position detection system - Google Patents

Description

  The present invention relates to a position detection system that specifies the position of a moving body using one or more beacon signal generators and one or more communication terminals that receive beacon signals.

  Japanese Patent No. 4757105 (Patent Document 1) discloses beacon signal transmitters that are installed at various locations in a house and that transmit position information including an ID unique to each installation location and a beacon signal that is carried by a resident. A communication terminal that receives position information transmitted from a device and transmits the position information together with a terminal ID unique to the terminal, and a communication terminal in a house based on the position information and the terminal ID transmitted from the communication terminal There is disclosed an in-house monitoring system provided with a terminal position recognizing means for recognizing the position of and a display means for displaying the position of the communication terminal recognized by the terminal position recognizing means.

  Further, Japanese Patent No. 5396442 (Patent Document 2) discloses a position information system for recognizing the position of a mobile body equipped with a receiving terminal based on the identification information of a beacon signal generator and the received signal strength. ..

Japanese Patent No. 4757105 Japanese Patent No. 5396442

  When the position of the moving body is specified by using the ID of the beacon signal generator and the radio field intensity, when the communication terminal receives the plurality of beacon signals generated by the plurality of beacon signal generators, a plurality of beacon signals are generated. In the boundary area of the output range of the beacon signal, there is a problem that the radio wave intensities of the plurality of beacon signals fluctuate, and erroneous position determination is likely to occur.

  An object of the present invention is to provide a position detection system that can avoid erroneous position determination as much as possible when using radio field intensity.

  The position detection system of the present invention is installed at each of a plurality of predetermined installation positions in one or more moving areas where one or more moving bodies move, and generates a plurality of beacon signals that generate a beacon signal including a beacon ID. Device, one or more communication terminal devices attached to one or more mobile units to receive one or more beacon signals, and a position determination unit. The one or more communication terminals determine the beacon signal for position determination at a predetermined determination cycle from the field intensity of the received one or more beacon signals, and the beacon of the beacon signal generator that generates the beacon signal for position determination. It has a beacon ID determination storage unit that determines and stores an ID as a beacon ID for position determination, and a transmission unit that transmits position determination information including a beacon ID for position determination and a terminal ID that identifies itself. The position determination unit, one or more communication terminals, based on the beacon ID and terminal ID for position determination respectively determined, and information of a plurality of predetermined installation positions in the moving area, in a predetermined determination cycle, The position of one or more moving bodies in the moving area is determined. In the present invention, the beacon ID determination storage unit of the communication terminal has an intensity difference between the previous radio wave intensity and the current radio wave intensity of the beacon signal for position determination, which is determined in a predetermined determination cycle, equal to or less than a predetermined limit threshold value. Until, the beacon ID for position determination is not updated.

  The radio wave intensity of the beacon signal has a large intensity change rate (intensity difference) in a region near the beacon signal generator, and the intensity difference (change rate) of the radio wave intensity decreases as the distance from the beacon signal generator increases. Therefore, the beacon ID determination storage unit until the intensity difference between the previous radio wave intensity and the current radio wave intensity of the beacon signal for position determination adopted for determining the beacon ID for position determination becomes equal to or less than a predetermined limit threshold value. (In other words, the beacon ID for position determination is not updated until the communication terminal device is separated from the beacon signal generator used to determine the beacon ID for the previous position determination to some extent). In this way, even when the moving body enters the boundary area of the output range of the plurality of beacon signals, the previously determined current position is held. Then, when it is detected that the communication terminal is away from the beacon signal generator adopted for the determination of the beacon ID for the previous position determination to some extent by the intensity difference of the radio field intensity, the beacon ID for the position determination is updated. .. As a result, according to the present invention, the accuracy of position determination can be improved.

  In addition, when one or more moving areas are divided into upper and lower moving areas, or when the partition walls between moving areas are thin, etc., the moving areas on other floors or An erroneous determination may be made by receiving a beacon signal from a beacon signal generator installed in an adjacent moving area. In order to prevent erroneous determination even in such an environment, it is preferable to add the following configuration.

  As a first additional configuration, one or more switching beacon signal generators that are installed on a route that a mobile body passes through when moving between two moving areas and that generate a switching beacon signal including a predetermined switching beacon ID. Further provide. The beacon ID determination storage unit of the one or more communication terminals is configured to detect the position with the strongest radio wave intensity among the one or more position determination beacon signals received after receiving the switching beacon signal having a predetermined radio wave intensity or higher. If the beacon signal for determination is equal to or larger than the predetermined area determination threshold, the beacon ID for position determination is stored as the area ID. In addition, the beacon ID determination storage unit includes one or more position determining beacon generators generated by one or more position determining beacon generators installed in the moving area specified by the area ID among the one or more beacon signals received in the determination period. A beacon signal for position determination is determined from the radio field intensity of the beacon signal. With this arrangement, the beacon signal for position determination having the strongest radio wave intensity among the beacon signals for position determination received after receiving the switching beacon signal having a predetermined radio field intensity or more and having the area determination threshold value or more. Since the beacon ID of the beacon signal is the area ID, it is not necessary to associate the switching beacon ID with the position information like the beacon ID for position determination. As a result, there is no problem even if all the switching beacon IDs are the same, and the switching beacon signal generator can be placed at any position. The position determination beacon ID of the position determination beacon signal having the strongest radio field intensity is stored as an area ID, and the movement specified by the area ID is continued until a switching beacon signal having a predetermined radio field intensity or more is received thereafter. Only the beacon ID of the beacon signal from the beacon signal generator installed in the area is used for updating the beacon ID for position determination (update of the current position). As a result, it is possible to prevent an erroneous determination from being made due to the influence of beacon signals coming from other moving areas.

  In the first additional configuration, beacon signals from different moving areas are sequentially excluded to determine the beacon ID used for updating the current position. However, at the stage immediately before transmitting the beacon ID used for updating the current position to the position determining unit. It is also possible to exclude updating as a beacon ID for position determination based on the beacon ID of a beacon signal that has entered from another moving area. Even in the second additional configuration that realizes this, the beacon ID determination storage unit has the highest radio field intensity among the one or more position determination beacon signals received after receiving the switching beacon signal having a predetermined radio field intensity or higher. If the beacon signal for position determination having a high strength is equal to or larger than a predetermined area determination threshold value, the beacon ID for position determination is stored as an area ID. Then, the beacon ID determination storage unit determines the beacon signal for position determination from the radio field intensity of one or more beacon signals received within the determination cycle, and determines the moving area specified by the area ID at the final stage of the determination cycle. The beacon ID of the beacon signal for position determination is used as the beacon ID for position determination when the moving area in which the beacon generator for position determination that generates the beacon signal for position determination is installed is matched. Update. Even in this case, similarly to the first additional configuration, it is not necessary to associate the switching beacon ID with the position information like the beacon ID for position determination. Further, only the beacon ID of the beacon signal from the beacon signal generator installed in the moving area specified by the area ID is used to update the beacon ID for position determination (update the beacon ID of the current position). As a result, it is possible to prevent an erroneous determination from being made due to the influence of beacon signals coming from other moving areas.

  Further, in the third additional configuration, unlike the first additional configuration and the second additional configuration, the position determination unit does not update and determines the beacon ID for position determination on the communication terminal side, and the beacon for position determination is performed by the position determination unit. Make the final decision to update the ID. Therefore, in the third additional configuration, the beacon ID determination storage unit of the one or more communication terminals has one or more of the beacon signals for position determination received after receiving the switching beacon signal having a predetermined radio field intensity or higher. The beacon ID for position determination of the beacon signal for position determination having the strongest radio field strength is stored as an area ID. Further, the beacon ID determination storage unit determines the beacon signal for position determination from the radio field intensities of one or more beacon signals received within the determination period, and determines the area ID and the beacon ID of the determined beacon signal for position determination. And transmits the terminal ID of the communication terminal to the position determination unit. Then, in the position determining unit, when the moving area determined by the beacon ID of the beacon signal for position determination and the moving area determined by the area ID match, the position determination unit determines the final beacon ID by the beacon ID of the determined beacon signal for position determination. Update the current position. Thus, if the area ID determined by the position determination unit is used to determine the update of the beacon ID for position determination and the final current position is directly updated, the load on the communication terminal can be reduced.

  Note that the limit threshold value is determined so as to prevent erroneous detection due to reception of outputs of two or more beacon signal generators, but theoretically speaking, the limit threshold value is two or more beacon signal generators. It is preferable that the difference in intensity is set so as not to be equal to or less than the limit threshold value in the boundary region where the output ranges of 1 and 2 overlap.

  The beacon ID determination storage unit determines the previous radio wave intensity and the current radio wave intensity based on the average value of the radio wave intensity of a plurality of beacon signals received in a predetermined measurement cycle shorter than the determination cycle within one cycle of the determination cycle. It is preferable to determine the radio wave intensity of. By using such an average value, it is possible to correct the variation in the measurement data.

  The average value can be calculated as a simple average of the signal strengths of multiple beacon signals, the median value of the signal strengths of the beacon signals, or the maximum and minimum values of the signal strengths of the beacon signals. It may be obtained as a simple average value of the remaining radio wave intensity except for, and the method is arbitrary.

  The beacon ID determination storage unit is configured such that the intensity difference between the radio wave intensity of the beacon signal for position determination adopted for the determination of the beacon ID for position determination and the radio wave intensity of another beacon signal is greater than a predetermined intensity difference threshold value. When it becomes larger, the beacon ID of another beacon signal generator whose strength difference becomes larger than the strength difference threshold is updated as the beacon ID for position determination. When the signal strength of beacon signals from other beacon signal generators is obviously high, there is no difference in being near that beacon signal generator and there is no risk of erroneous detection, so updating the beacon ID for position determination Is preferably performed.

  When the determination cycle has a length equal to or longer than the determination cycle, even if the number of moving bodies increases, the calculation processing of the position determination unit can be reduced, and the number of moving bodies can be increased. be able to.

  The length of the decision period is preferably adjustable. In this way, the calculation load of the position determination unit can be adjusted according to the increase or decrease in the number of moving bodies.

  In order to detect the displacement of the position of the moving body quickly, when the beacon ID determination storage unit stores the update of the beacon ID for position determination, the transmission unit outputs the updated beacon ID for position determination and the terminal ID. It suffices to immediately make a call to the position determination unit.

  Even when the transmitting unit immediately transmits the updated beacon ID and terminal ID for position determination to the position determining unit so that the displacement of the position of the moving body can be quickly detected, the calculation load of the position determining unit is reduced. You can For example, when the position determination unit issues a transmission request to the transmission unit in the determination cycle, the transmission unit transmits the latest beacon ID for position determination stored in the beacon ID determination storage unit to the position determination unit. Make up the department. Then, if the position determining unit transmits the updated beacon ID for position determination and the terminal ID before the one period of the determination period expires, the transmission request is made even if the one period expires. It is configured not to issue. In this way, an unnecessary call request is not issued, and the load on the position determination unit can be reduced.

  When the position determination unit issues a transmission request to the transmission unit in the determination cycle, the transmission unit transmits the latest beacon ID for position determination stored in the beacon ID determination storage unit to the position determination unit. Even if is configured, if the beacon ID determination storage unit stores the update of the beacon ID for position determination before one determination period expires, the transmission unit is updated even if there is no transmission request. The beacon ID for position determination and the terminal ID may be immediately transmitted to the position determination unit. In this way, even if the determination period is set long, if there is a displacement of the position of the moving body, that displacement can be detected quickly.

  Further, when the position determination unit issues a transmission request to the transmission unit in the determination cycle, the transmission unit transmits the latest beacon ID for position determination stored in the beacon ID determination storage unit to the position determination unit. Even if the section is configured, the transmitting section responds to the transmission request only when the beacon ID determination storage section updates the beacon ID for position determination until one cycle of the determination cycle expires. The updated beacon ID and terminal ID for position determination may be transmitted to the position determination unit. In this way, if the beacon ID for position determination is not updated, the communication terminal does not transmit, so that the life of the communication terminal can be extended.

  When the position determination unit issues a transmission request to the transmission unit in the determination cycle, the transmission unit causes the transmission unit to transmit the latest beacon ID for position determination stored in the beacon ID determination storage unit to the position determination unit. Even if configured, the position determination beacon ID transmitted from the transmission unit in response to the previous transmission request and the position determination beacon ID stored in the beacon ID determination storage unit at the time of this transmission request are different. The transmitting unit may transmit the beacon ID and the terminal ID for position determination different from the previous one to the position determining unit only when performing. In this method, even if the beacon ID for position determination is updated during one cycle of the determination cycle, if the beacon ID for the previous position determination is the same as the previous beacon ID for position determination when the transmission request is made, the beacon in one cycle of the determination cycle It is based on the idea that it is not necessary to send a change in ID. Even in this case, it is possible to reduce the load on the position determination unit and reduce the load on the communication terminal device.

  Further, the beacon ID determination storage unit is used for determining the beacon ID for position determination, in which the intensity difference of the radio wave intensities of the beacon signals for position determination used for determining the beacon ID for position determination is equal to or less than a limit threshold value. When the intensity difference between the intensity of one beacon signal and the intensity of another beacon signal is smaller than a predetermined intensity difference threshold, the intensity of the beacon signal used to determine the beacon ID for position determination. If the peak hold value measured this time is within the peak hold value range to which the peak hold value belongs, determine which of the multiple peak hold value ranges the peak hold value belongs to. When the beacon ID for position determination is not updated and the peak hold value range is exceeded, one or more beacon signals received at that time are reported. Based on the beacon ID of maximum field intensity of the beacon signal, preferably updates the beacon ID for position determination. In this way, if there is no error in updating the beacon ID for position determination, even if the radio field intensity of the beacon signal from another beacon signal generator has changed significantly, if there is no error, the position determination Beacon ID update possible.

  The peak hold value is calculated as a simple average of the peak values of the radio field intensities of the beacon signals, the median of the peak values of the radio field intensity of the beacon signals, or the radio wave intensity of the beacon signals of the beacon signals. It can be obtained as a simple average value of the peak hold values of the remaining radio wave intensity excluding the maximum and minimum peak values. In this way, the possibility of erroneous position determination can be greatly reduced even if the measured radio field intensity data varies.

1 is a plan view showing a beacon signal generator arranged in a moving area and a communication terminal mounted on a moving body moving in the moving area in a first embodiment of a position detection system of the present invention. It is a figure used in order to explain the composition of a 1st embodiment. (A) is a diagram showing the relationship between the distance between the beacon signal generator and the communication terminal and the radio field intensity, and (B) is a diagram showing the relationship between the distance and the radio field intensity difference. It is a figure used in order to demonstrate the 2nd update condition. It is a figure which shows the relationship between the distance used for demonstrating a 2nd update condition, and a radio wave intensity. It is a flow chart which shows an algorithm of software used with a communication terminal in a 1st embodiment. It is a flowchart which shows the algorithm of the software used with the communication terminal device used in the 2nd Embodiment of this invention. 8 is a flowchart showing details of step S2A in FIG. 7. It is a figure used in order to explain the environment which uses a 2nd embodiment. (A) And (B) is a figure which shows the relationship between the signal arrival distance of a switching threshold value and an area determination threshold value. It is a figure which shows the beacon registration information in the position determination part built in a communication terminal device or a server as a concept. It is a flowchart which shows the algorithm of the software used with the communication terminal device used in 3rd Embodiment. 13 is a flowchart showing details of step S12 ′ in FIG. It is a flowchart which shows the algorithm of the software used with the communication terminal device used by 4th Embodiment. It is a flowchart which shows the algorithm of the software used by the position determination part located in the server side.

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
1 and 2, the position detection system according to the first embodiment of the present invention includes a plurality of beacon signal generators 101 to 10N (N is an arbitrary positive integer) and a plurality of moving bodies 60A and 60B. A plurality of communication terminals 20A to 20N mounted on the 60N and a position determination unit 70 that determines the positions of the mobile units 60A, 60B, ... The plurality of communication terminals 20A to 20N incorporate beacon ID determination units 30A to 30N including beacon ID determination storage units 40A to 40N and transmission units 50A to 50N.

  The plurality of beacon signal generators 101 to 10N are provided in N number, and each of the beacon signal generators 101 to 10N of Nos. 1, 2 ... N is one or more in which a plurality of mobile bodies 60A, 60B ... Are installed at a plurality of predetermined installation positions within the moving area. In FIG. 1, eight beacon signal generators 101, 102, ... 108 are shown in one moving area. The plurality of beacon signal generators 101 to 10N are, for example, mounted on the ceiling in the moving area in order to prevent the movement of the moving bodies 60A, 60B, ... 60N and to avoid the influence of objects existing in the moving area. preferable. As shown in FIG. 1, the beacon signal generators 101, 102 ... 108 are arranged in a matrix with a predetermined distance therebetween. Each of the beacon signal generators 101, 102, ... 108 emits a beacon signal including a unique beacon ID (identifier) downward with a predetermined radio field intensity.

  A plurality of communication terminals 20A to 20N are provided, and one of each of the communication terminals 20A to 20N is attached to each of the plurality of mobile units 60A to 60N, and a plurality of beacon signal generators 101 to 10N emit. Each beacon signal is received by the omnidirectional antenna, and the received result is processed by each built-in beacon ID determination unit 30A to 30N. In FIG. 1, mobile bodies 60A and 60B are equipped with communication terminals 20A and 20B, respectively. At the construction site or in the factory, it is preferable that the communication terminal is attached to the helmet of the worker. If the communication terminal device includes a temporary data storage unit, the communication terminal device stores all measurement data in the temporary data storage unit, and the beacon for position determination is determined later by the beacon ID determination units 30A to 30N. It goes without saying that the position determining information including the ID and the terminal ID for identifying the own communication terminal device may be transmitted to the position determining unit 70.

  Beacon ID determination units 30A to 30N include beacon ID determination storage units 40A to 40N and transmission units 50A to 50N, and are incorporated in each communication terminal device 20A to 20N. The beacon ID determination storage units 40A to 40N determine a beacon signal for position determination from the radio field intensity of one or more received beacon signals at a predetermined determination cycle (specifically, for example, 1 second) and determine the position determination signal. The beacon ID of the beacon signal generator that generates the beacon signal is determined and saved as the beacon ID for position determination. The transmission units 50A to 50N transmit the position determination information including the position determination beacon ID and the terminal ID that identifies itself to the position determination unit 70.

  The position determination unit 70 includes a beacon ID and a terminal ID for position determination that are periodically transmitted from each of the communication terminals 20A to 20N, and a plurality of predetermined installations within the moving area of each beacon signal generator 101 to 10N. Based on the position information (corresponding to the information in which the installation position of the beacon signal generator in the moving area is stored as map data), each mobile body 60A, at a predetermined determination cycle (specifically, 5 seconds).・ Determine the position in the movement area of. In the present embodiment, the radio field intensity is not used directly for position determination, but is used for determining the condition for updating the beacon ID for position determination. It does not determine the position.

  Note that in the present embodiment, the determination of the current position is made by determining whether or not the mobile unit (communication terminal device) is within the range of the beacon signal generator that the radio wave reaches. Therefore, it is not determined how far the mobile object (communication terminal device) is from the beacon signal generator. Therefore, the calculation required for position determination does not become complicated.

  Then, in the present embodiment, the beacon ID determination storage units 40A to 40N of the beacon ID determination units 30A to 30N are used to determine the beacon ID for position determination. The beacon ID for position determination will not be updated until the intensity difference between and becomes less than or equal to a predetermined limit threshold value. FIG. 3A is a diagram showing the relationship between the distance between the beacon signal generator and the communication terminal and the radio field intensity, and FIG. 3B is the intensity difference between the moving distance and the radio field intensity in the relationship of FIG. 3A. It is a figure which shows the relationship of. As shown in FIGS. 3 (A) and 3 (B), regarding the radio wave intensity of the beacon signal, the change rate (intensity difference) of the radio wave intensity (RSSI) is large in a region near the beacon signal generator, and As the distance increases, the strength difference (rate of change) of the radio field strength (RSSI) decreases. Therefore, the beacon ID determination storage units 40A to 40N determine that the intensity difference between the previous radio wave intensity and the current radio wave intensity of one beacon signal used to determine the beacon ID for position determination is a predetermined threshold value (FIG. 3). In the example of (A), about 5 dB or less (when changing the viewpoint, until the communication terminal device is separated to some extent from the beacon signal generator used to determine the beacon ID for the previous position determination), Do not update the beacon ID. In the example of FIG. 3 (A), the limit threshold value becomes about 5 dB when the point is separated from 4 m to 6 m.

  By doing so, even when the mobile bodies 60A to 60N enter the boundary area of the output range of the plurality of beacon signals, the beacon ID for position determination determined last time is held. Then, when it detects that the mobile body (communication terminal device) is separated from the beacon signal generator used for the determination of the beacon ID for the previous position determination to some extent by the intensity difference of the radio field intensity, the beacon ID for the position determination is updated. Will be done. The position determination unit 70 receives the update of the beacon ID for position determination and updates the current position of the moving body.

  This will be described with reference to FIG. 1. The moving body (worker) 60A wearing the communication terminal device 20A is performing work while repeating movement within the work area R. In such a case, if the beacon ID (current position) for position determination is simply determined only by the radio field intensity, the position of the mobile unit 60A frequently changes between the beacon signal generators 101, 102, 103 and 104 in a short time. It changes and fluctuates. In the present embodiment, assuming that mobile unit 60A moves from the direction in which beacon signal generator 103 is installed into the work area in which beacon signal generator 102 is installed, four beacon signal generators 101 to 101- Only the radio field intensity of the beacon signal generator 103 used for determining the beacon ID (current position) for position determination in 104 becomes a problem, and the previous radio field intensity of the beacon signal generator 103 and the current radio field intensity The beacon ID (current position) for position determination is not updated unless the intensity difference of 1 is less than or equal to a predetermined threshold value.

  In the example of FIG. 1, if the mobile unit 60A moves only within a certain work area without being far away from the beacon signal generator 103, the other beacon signal generators 101, 102 or 104 have higher radio field intensity. Even if it does, the beacon ID (current position) for position determination is not updated by itself. Then, when the work in the work area is completed and the mobile body 60A moves, the intensity difference between the previous and present radio wave intensities of the beacon signal generator 103 becomes small. Since it is far away, the beacon ID of the beacon signal generator having the highest radio wave intensity at that time is adopted as the beacon ID for position determination, and the current position is updated. For example, when the worker enters the radio wave area of the beacon signal generated by the beacon signal generator 102, the position specified by the beacon ID of the beacon signal generator 102 is updated as the current position where the worker currently exists.

  When controlled in this way, for example, the mobile body 60A equipped with the communication terminal 20A can correctly receive the beacon signal from the beacon signal generator 103 within one second, even though the mobile body 60A is near the beacon signal generator 103. When it is not possible, the radio field intensity is measured as -127 dBm, and it is possible to obtain the effect of preventing a malfunction in which the beacon signal of the farther beacon signal generator 102 or the like is adopted and the current position is updated.

  This limit threshold value (about 5 dB in the example of FIG. 3 (A)) is set so as to prevent erroneous detection due to reception of two or more beacon signal generators 101 ... Theoretically, the limit threshold value is a difference in strength (preceding one beacon signal used for determining the beacon ID for position determination in the boundary area where the output ranges of two or more beacon signal generators 101 ... If the difference between the radio wave intensity and the current radio wave intensity) is set so as not to be less than or equal to the limit threshold value, it is possible to prevent the beacon ID for position determination from frequently switching, and to realize accurate position detection. The specific numerical value is determined based on the intensity of the radio wave emitted by the beacon signal generator 101, the installation interval, and the like.

  Beacon ID determination storage sections 40A to 40N average the radio wave intensities of a plurality of beacon signals received in a measurement cycle (1/10 seconds in the present embodiment) shorter than the determination cycle within one cycle of the determination cycle. Value is calculated, this average value is determined as the radio field intensity, and stored in the internal memory. The beacon ID determination storage units 40A to 40N determine the beacon ID for position determination based on this average value. That is, the beacon ID determination storage units 40A to 40N record and hold the average value of the previous radio wave intensity in the internal memory, and when the beacon ID for position determination is determined, the previous radio wave read from the internal memory. The intensity is compared with the newly calculated average value of the radio wave intensity of this time. By using the average value in this way, it is possible to correct the variation in the measurement data and minimize the influence of measurement error.

  In this embodiment, the “average value” is obtained as a simple average of a plurality of radio wave intensities of a plurality of beacon signals received in a predetermined measurement cycle shorter than the determination cycle within one cycle period. In the embodiment described above, it is determined as the median value of the radio wave intensities of the plurality of beacon signals, or as the simple average value of the remaining radio wave intensities excluding the maximum and minimum values of the radio wave intensities of the plurality of beacon signals.

  Beacon ID determination storage units 40A to 40N change the beacon ID for position determination under the following beacon ID update conditions in addition to the above determination conditions. This determination condition will be described with reference to FIGS. 4 and 5. When passing through the area where four beacon signal generators 1 to 4 are installed as shown in FIG. 4 on the walking route shown in the figure, the communication terminal mounted on the mobile receives from the four beacon signal generators. The field intensity of the beacon signal to be transmitted is as shown in FIG. First, the intensity difference D between the radio wave intensity of one beacon signal (beacon 1 in FIG. 5) adopted for determining the beacon ID for position determination and the radio wave intensity (beacon 2) of another beacon signal is predetermined. When it becomes larger than the intensity difference threshold (for example, 10 dB), the beacon IDs of the other beacon signal generators 2 (beacons 2 in FIGS. 4 and 5) whose intensity difference becomes larger than the intensity difference threshold are used for new position determination. Beacon ID. The position determination unit 70 updates the current position of the communication terminal based on the update of the beacon ID for position determination. This is because when the radio wave intensity of the beacon signal from the other beacon signal generator 2 is obviously high, there is no difference that the moving body is near the beacon signal generator 2, and there is no possibility of erroneous detection, This is because updating the current position enables more accurate position determination.

  In the update processing of the current position, for example, there is an intensity difference in which the difference between the intensity of the previously determined beacon signal of this time and the intensity of the beacon signal of the strongest reception intensity of this time exceeds the intensity difference threshold of 10 dBm. Applied in case. The intensity difference threshold value is determined according to the radio wave intensity of the beacon signal generated by the beacon signal generator 101 ..., The installation interval, the assumed moving speed of the moving body 60A.

  Furthermore, the beacon ID determination storage units 40A to 40N of the present embodiment, the intensity difference of the radio wave intensity of the beacon signal adopted to determine the beacon ID for position determination used to determine the current position is equal to or less than the limit threshold, In addition, when the intensity difference between the radio wave intensity of one beacon signal used for determining the beacon ID for position determination and the radio wave intensity of another beacon signal is larger than a predetermined intensity difference threshold value, A peak to which the peak hold value belongs is determined by determining which of a plurality of predetermined peak hold value ranges the radio wave intensity of the beacon signal for position determination used to determine the beacon ID belongs to. When the next measured peak hold value is within the hold value range, the beacon ID for position determination is not updated and the peak hold value range is exceeded. Sometimes, it adopts an update condition for the beacon ID for position determination beacon ID of the largest field intensity of the beacon signal of at least one beacon signal being received at that time. The position determination unit 70 updates the current position of the moving body based on the beacon ID for position determination and the information on the installation positions of the plurality of beacon signal generators.

  The peak hold value is the value of the strongest radio wave intensity among the received beacon signals for each cycle, and therefore the beacon signal generator used by the mobile unit to determine the beacon ID for position determination is used. As the radio wave intensity becomes stronger as it gets closer, the value is recorded and updated in the beacon ID determination storage units 40A to 40N each time. During the process in which the mobile body moves away from the beacon signal generator, the radio field intensity gradually weakens, so the peak hold value is not updated.

  The peak hold value range can be arbitrarily set according to the radio field intensity emitted by the beacon signal generators 101 to 10N, the installation interval, and the like. Table 1 shows an example of the relationship between the peak hold value and the peak hold value range corresponding to the peak hold value in this embodiment. For example, if the peak hold value is -60 dBm, the corresponding peak hold value range is "peak hold value -20". Therefore, when the subsequently measured peak hold value falls below -80 dBm, the peak hold value range is Will be exceeded.

For example, in FIG. 1, assuming that the peak hold value of the beacon signal from the beacon signal generator 103 for the mobile unit 60A is -60 dBm, the next measurement is performed while the mobile unit 60A is moving within the current work area. The peak hold value does not exceed −80 dBm, and the beacon ID for position determination is not updated. When the mobile unit 60A leaves the present work area and moves to another work area, the peak hold value measured next from the beacon signal generator 103 gradually weakens and eventually exceeds −80 dBm. The beacon ID for position determination is updated for the first time.

  In this way, when the radio wave intensity of the beacon signal from the other beacon signal generators 101 ... It enables updating and enables more accurate position determination.

  In this embodiment, the peak hold value is obtained as a simple average of the peak values of the radio field intensities of the beacon signals, but in other embodiments, the median of the peak values of the radio field intensity of the beacon signals. Or a simple average value of the peak hold values of the remaining radio wave intensity excluding the maximum and minimum peak values of the radio wave intensity of a plurality of beacon signals. This can greatly reduce the possibility of erroneous position determination even if the measured radio field intensity data varies.

  The position detection system according to this embodiment includes a BLE beacon that emits a beacon signal including a beacon ID, a communication terminal device worn by a worker (mobile body), a base station that receives transmission data from the communication terminal device, and a base station. It can be configured by a server and an application that receives data from the station and performs each process. The position determination unit 70 is built in the server.

  Next, an algorithm of software used in the communication terminal device of the present embodiment will be described with reference to FIG. 6 is used by one communication terminal device 20A, 20B ... To determine the position of the communication terminal device 20A, 20B .. The process of the arithmetic processing for updating the beacon ID for position determination is shown. This arithmetic processing is performed for each of the plurality of communication terminals 20A, 20B.

  In FIG. 6, the beacon ID determination storage unit 40A ... Determines whether or not a beacon is received within one cycle (step S1), and if a beacon is received, communication within one cycle is performed at a predetermined measurement cycle shorter than the determination cycle. For the reception data received by the terminal device 20A, ..., An average value of radio wave intensity is calculated for each beacon ID emitted by each beacon signal generator 101. It is recorded and held in the internal memory of the ID determination storage unit 40A ... (Step S2). As described above, the average value is a simple average of the radio wave intensities of the respective IDs received in a predetermined measurement cycle shorter than the determination cycle within one cycle period.

  Next, the beacon ID determination storage unit 40A ... is equal to or smaller than a predetermined threshold value in the intensity difference between the radio wave intensity of the previous beacon signal and the radio wave intensity of the current beacon signal used for determining the beacon ID for position determination. Processing (step S3), the strength difference between the signal strength of one beacon signal and the signal strength of another beacon signal used to determine the beacon ID for position determination is a predetermined strength difference threshold value. Is larger than the peak hold value (step S4), and the peak hold value range is set according to the peak hold value, and the next measured peak hold value is within the peak hold value range (step S5). , 6). Since these three processes are performed on the premise of the determination in step S7 and subsequent steps, which will be described later, the arithmetic processes may be performed in parallel regardless of the order of the arithmetic processes.

  First, it is determined whether or not the determination in step S3 is OK (step S7), and if No (the intensity difference exceeds the limit threshold), the beacon ID for position determination is not updated (step S8), one cycle before The beacon ID for position determination is adopted. If step S7 is Yes, it is then determined whether the determination in step S4 is OK (step S9), and if No (the intensity difference is smaller than the intensity difference threshold), the beacon ID for position determination is not updated ( If step S8) and step S4 are Yes, it is determined whether the determination of step S6 is OK (step S10), if Yes, the beacon ID for position determination is updated (step S11), and if No, the position is determined. The beacon ID for determination is not updated (step S8).

  The current position in the position determination unit 70 is updated by setting the installation position of any of the beacon signal generators 10A to 10N having the highest radio wave intensity measured this time as the current position of the mobile body 60A.

  Finally, the transmission data for the determination of the next cycle is recorded in the beacon ID determination storage unit 40A, ..., Retained and updated (step S12), and the processing of one determination cycle ends. Specifically, the beacon ID for position determination, the radio wave intensity of the beacon signal used for the determination, and the peak hold value are updated. The position determination unit 70 has a built-in position storage unit that stores the determined current position.

  As described above, according to the position detection method according to the present embodiment, the accuracy of position determination can be improved. The determination cycle (for example, 5 seconds) by which the position determination unit determines the position of the moving body has a length equal to or longer than the determination cycle (1 second). Therefore, even when the number of moving bodies increases, the calculation processing of the position determination unit 70 can be reduced, and the number of moving bodies can be increased. The length of the decision period is preferably adjustable. In this way, the calculation load of the position determination unit 70 can be adjusted according to the increase or decrease in the number of moving bodies.

[Modification]
In order to quickly detect the displacement of the position of the moving body, if the beacon ID determination storage units 40A to 40N store the update of the beacon ID for position determination before one cycle of the determination cycle expires, the transmission unit 50A. ˜50N may immediately transmit the updated position determination beacon ID and terminal ID to the position determination unit 70.

  Further, even when the transmitting units 50A to 50N immediately transmit the updated position determination beacon ID and terminal ID to the position determination unit 70 so that the displacement of the position of the moving body can be quickly detected, the position determination unit The calculation load of 70 can be reduced. For example, when the position determination unit 70 issues a transmission request to the transmission units 50A to 50N in the determination cycle, the transmission unit 50A to 50N stores the latest beacon ID for position determination stored in the beacon ID determination storage units 40A to 40N. The transmitting units 50A to 50N are configured to transmit the position determining unit 70 to the position determining unit 70. Then, if the position determining unit 70 transmits the updated beacon ID for position determination and the terminal ID from the transmitting units 50A to 50N before one period of the determining period expires, the one period expires. However, it is configured not to issue a call request. In this way, an unnecessary call request is not issued, so that the load on the position determination unit 70 can be reduced.

  When the position determination unit 70 issues a transmission request to the transmission units 50A to 50N in the determination cycle, the transmission units 50A to 50N use the latest beacon IDs for position determination stored in the beacon ID determination storage units 40A to 40N. Even if the transmission units 50A to 50N are configured to transmit to the position determination unit 70, the beacon ID determination storage units 40A to 40N update the beacon ID for position determination before one period of the determination period expires. If the transmission request is not stored, the transmission units 50A to 50N may immediately transmit the updated position determination beacon ID and terminal ID to the position determination unit 70. In this way, even if the determination period is set long, if there is a displacement of the position of the moving body, that displacement can be detected quickly.

  Further, when the position determination unit 70 issues a transmission request to the transmission units 50A to 50N in the determination cycle, the transmission units 50A to 50N use the latest beacon ID for position determination stored in the beacon ID determination storage units 40A to 40N. Even when the transmission units 50A to 50N are configured to transmit to the position determination unit 70, the beacon ID determination storage units 40A to 40N are configured to determine the beacon IDs for position determination by the end of one determination period. The transmitters 50A to 50N may transmit the updated position determination beacon ID and terminal ID to the position determination unit 70 in response to the transmission request only when the update is performed. In this way, if the beacon ID for position determination is not updated, the communication terminals 20A to 20N do not transmit, so that the life of the communication terminals 20A to 20N can be extended.

  When the position determination unit 70 issues a transmission request to the transmission units 50A to 50N in the determination cycle, the transmission units 50A to 50N position the latest beacon ID for position determination stored in the beacon ID determination storage units 40A to 40N. Even when the transmission units 50A to 50N are configured to transmit to the determination unit 70, the beacon ID for position determination transmitted from the transmission units 50A to 50N in response to the previous transmission request and the beacon at the time of this transmission request. Only when the beacons for position determination stored in the ID determination storage units 40A to 40N are different, the transmission units 50A to 50N transmit to the position determination unit 70 a beacon ID and a terminal ID for position determination different from the last time. You may do it. In this method, even if the beacon ID for position determination is updated during one cycle of the determination cycle, if the beacon ID for the previous position determination is the same as the previous beacon ID for position determination when the transmission request is made, the beacon in one cycle of the determination cycle It is based on the idea that it is not necessary to send a change in ID. Even in this case, the load on the position determination unit 70 can be reduced, and the load on the communication terminals 20A to 20N can be reduced.

[Second Embodiment]
FIG. 7 shows an algorithm of software used in the communication terminal used in the second embodiment of the present invention, and FIG. 8 is a flowchart showing details of step S2A in FIG. In the present embodiment, as shown in FIG. 9, when one or more moving areas are divided into upper and lower moving areas, or when the partition walls between the moving areas are thin, etc. Alternatively, a beacon signal from a beacon signal generator installed in a moving area on another floor or an adjacent moving area through a thin partition is received to prevent an erroneous determination. In FIG. 9, there is a stairway between the moving area 1F on the first floor and the moving area 2F on the second floor, and between the moving area 2F on the second floor and the moving area 3F on the third floor. Therefore, in this example, switching beacon signal generators 100 with the switching beacon ID set to the common "ID: 50000" are provided at the entrances and exits of the stairs on each floor. In the moving area 1F on the first floor, a plurality of position determining beacon generators 101, 102 ... whose beacon IDs are set to ID13, ID24 ... Has a plurality of position determination beacon generators 103, 104 ... With beacon IDs set to ID: 21, ID9 ..., Beacon ID: 59 in the moving area 3F on the third floor. , ID31 ..., A plurality of position determination beacon generators 105, 106 ... Are installed. In this environment, in order to prevent erroneous determination due to arrival of a beacon signal from another moving area, the following configuration is added in the present embodiment.

  Note that in FIG. 7, one communication terminal device (20A, 20B ...) As shown in FIG. 2 determines the position of the communication terminal device (20A, 20B ..), that is, the position of the mobile body 60A, 60B. 5 is a flowchart of a calculation process for updating a beacon ID for position determination used for determination for each determination period. This arithmetic processing is performed for each of the plurality of communication terminals (20A, 20B ...). In the algorithm of FIG. 7, steps that are the same as those of the algorithm of FIG. 6 are given the same step numbers as the step numbers shown in FIG. The algorithm of FIG. 7 differs from the algorithm of FIG. 6 in steps S2A and S2B.

  As an additional configuration of the present embodiment, moving between two moving areas (between moving area 1F on the first floor and moving area 2F on the second floor, moving area 2F on the second floor and moving area 3F on the third floor) Further provided is one or more switching beacon signal generators 100 that are installed on a path through which the bodies 60A and 60B move to generate a switching beacon signal including a predetermined switching beacon ID (ID: 50000).

  Then, the beacon ID determination and storage units (40A, 40B ...) Of the plurality of communication terminals (20A, 20B ...) Perform the area ID processing of step S2A in FIG. This area ID processing is as shown in FIG. In step S21, it is determined whether the switching beacon signal is received at a switching threshold value or more (for example, −75 dB) or more. If Yes, the process proceeds to step S22 and shifts to the switching mode. If No, the process proceeds to step S23, and it is determined whether or not the switching mode is set. If it is the switching mode, the process proceeds to step S24, and the beacon ID for position determination of the beacon signal for position determination having the strongest radio wave intensity among the received one or more position determination beacon signals is equal to or greater than the area determination threshold value. If (for example, -70 dB or more), this beacon ID is stored as an area ID (steps S24 and S25). Then, in step S26, the switching mode is canceled to switch to the normal mode in FIG. The relationship between the switching threshold and the signal arrival distance of the area determination threshold (X: 30 m, for example) is as shown in FIGS. 10 (A) and 10 (B).

  Returning to the normal mode of FIG. 7, in steps S2B to S11, the beacon ID determination storage unit (40A, 40B ...) The moving area specified by the area ID among the one or more beacon signals received within the determination period. A beacon signal for position determination is determined from the radio field intensity of one or more beacon signals generated by one or more beacon generators for position determination installed therein. In particular, in step S2B, it is confirmed whether each beacon ID received within one cycle of the determination cycle is a beacon ID in the same area as the area ID, and only the beacon signal of the beacon ID in the same area is subjected to the average value of the radio wave intensity. Record as intensity. Then, after step S3, the same processing as in the first embodiment is performed.

  According to the present embodiment, the area of the beacon signal for position determination having the strongest radio field strength among the beacon signals for position determination received after receiving the switching beacon signal of a predetermined radio field strength or higher is determined. Since the beacon ID equal to or greater than the determination threshold is set as the area ID, it is not necessary to associate the switching beacon ID with the position information like the beacon ID for position determination. As a result, there is no problem even if all the switching beacon IDs are the same, and the switching beacon signal generator can be placed at any position. The position determination beacon ID of the position determination beacon signal having the strongest radio field intensity is stored as an area ID, and the movement specified by the area ID is continued until a switching beacon signal having a predetermined radio field intensity or more is received thereafter. Only the beacon ID of the beacon signal from the beacon signal generator installed in the area is used for updating the beacon ID for position determination (update of the current position). As a result, it is possible to prevent an erroneous determination from being made due to the influence of beacon signals coming from other moving areas.

  Note that FIG. 11 is a diagram conceptually showing beacon registration information in the position determining unit (70) built in the communication terminal device (20A to 20N) or the server. According to this concept, the installation location of the beacon signal generator for position determination can be known from the beacon ID of the current position. The data in the installation location is not necessary for the processing in the communication terminal.

  Although the above description has been made on the assumption that there is a stairway between the two moving areas, the present embodiment can also be applied to the case where the elevator is used to move each floor. In this case, the switching beacon signal generator may be installed inside the elevator.

[Third Embodiment]
In the additional configuration of the second embodiment, beacon signals from different moving areas are sequentially excluded to determine the beacon ID used for updating the current position, but the beacon ID of the beacon signal coming from another moving area is determined. Updating as a beacon ID for position determination based on the above may be excluded. FIG. 12 shows the algorithm of the software used in the communication terminal used in the third embodiment for realizing this, and FIG. 13 is a flowchart showing the details of step S12 ′ in FIG. In the algorithm of FIG. 12, the same steps as those of the algorithms of FIGS. 6 and 7 are given the same step numbers as the step numbers shown in FIGS. 6 and 7. The area ID process of step S2A is the same as that of the second embodiment. Also in the third embodiment, the beacon ID determination storage unit (40A, 40B ...) Among the beacon signals for position determination, which are received after receiving the switching beacon signal having a predetermined radio field intensity or higher, If the beacon signal for position determination having the strongest radio wave intensity is equal to or higher than the predetermined area determination threshold value, the beacon ID for position determination is stored as the area ID. Then, the beacon ID determination storage unit (40A, 40B ...) Determines a beacon signal for position determination from the radio field intensities of one or more beacon signals received within the determination period. Then, in the final stage of the determination cycle in step ST12 ′, as shown in FIG. 13, first, referring to the installation position of the beacon ID determined in step S11 or step S8 of FIG. 12 (data of FIG. 11) for position determination The moving area of the beacon ID of the beacon is determined. Next, referring to the installation position of the beacon ID (FIG. 11), the moving area of the area ID determined in step S2A is determined (S122). Then, in step S123, the fact that the moving area in which the position determining beacon signal generator is installed matches the moving area specified by the area ID means that the beacon ID of the position determining beacon signal is the beacon ID for position determining. (S124). If the moving area in which the position determining beacon signal generator is installed does not match the moving area specified by the area ID, the beacon ID of the position determining beacon signal is not updated as the position determining beacon ID (S125). ). Then, in step S126, the beacon ID of the final current position and the terminal ID of the communication terminal are transmitted to the position detector (70). That is, in the third embodiment, the movement area specified by the area ID and the movement area in which the position determination beacon generator that generates the position determination beacon signal determined by the area ID processing are installed are While doing so, the beacon ID of the beacon signal for position determination is updated as the beacon ID for position determination. Even in this case, similarly to the second embodiment, it is not necessary to associate the switching beacon ID with the position information unlike the beacon ID for position determination. Further, only the beacon ID of the beacon signal from the beacon signal generator installed in the moving area specified by the area ID is used to update the beacon ID for position determination (update the beacon ID of the current position). As a result, it is possible to prevent an erroneous determination from being made due to the influence of beacon signals coming from other moving areas.

[Fourth Embodiment]
In the additional configuration of the fourth embodiment, the position determining unit 70 does not perform update determination of the beacon ID for position determination on the communication terminal side as in the first embodiment and the second embodiment. Makes a final decision to update the beacon ID for position determination. FIG. 14 shows a software algorithm used in the communication terminal used in the fourth embodiment, and FIG. 15 shows a software algorithm used in the position determining unit 70 located on the server side. ing. In the algorithm of FIG. 14, the same steps as those of the algorithms of FIGS. 6 and 7 are given the same step numbers as the step numbers shown in FIGS. 6 and 7. The area ID process of step S2A is the same as that of the second embodiment. In the fourth embodiment, in step S12 ″, the beacon ID, the terminal ID, and the area ID determined in step S2A are transmitted to the position determination unit 70. On the position determination unit 70 side, the communication terminal device transmits the position determination unit 70 in step S101. A signal is received, and the moving area in which the position determining beacon generator determined by the beacon ID of the position determining beacon signal is installed is determined (step S102). Is determined by referring to the installation position information of the beacon ID (step S103), and the movement area in which the position determining beacon signal generator is installed matches the movement area approaching by the area ID. Then, the final current position is updated with the beacon ID of the determined beacon signal for position determination (step If the two movement areas do not match, the final current position is not updated (steps S104 and S106). For the position determination using the area ID determined by the position determination unit 70 in this way. If the update of the beacon ID is determined and the final current position is updated directly, the calculation load on the communication terminal device can be reduced.

  According to the position detection system of the present invention, the accuracy of position determination can be improved by avoiding incorrect position determination as much as possible.

101-10N Beacon signal generator 20A-20N Communication terminal device 30A-30N Beacon ID determination part 40A-40N Beacon ID determination storage part 50A-50N Sending part 60A, 60B Mobile body 70 Position determination part

Claims (17)

A plurality of beacon signal generators, each of which is installed at a plurality of predetermined installation positions in one or more moving areas in which one or more moving objects move, and which generates a beacon signal including a beacon ID;
The position determination is performed by receiving the one or more beacon signals attached to the one or more mobile bodies, determining a beacon signal for position determination at a predetermined determination cycle from the radio field intensity of the received one or more beacon signals, and determining the position. Beacon determination unit that determines and stores the beacon ID of the beacon signal generator that generates a beacon signal for use as a beacon ID for position determination, a beacon ID for position determination, and a terminal ID that identifies itself One or more communication terminals having a transmitter for transmitting position determination information including
The one or more communication terminals, the beacon ID and the terminal ID for position determination respectively determined, and based on information of the plurality of predetermined installation positions in the moving area, in a predetermined determination cycle, A position determination unit that determines the position of the one or more moving bodies in the moving area;
The beacon ID determination storage unit of the communication terminal is configured such that an intensity difference between the previous radio wave intensity and the current radio wave intensity of the beacon signal for position determination determined in the predetermined determination cycle is equal to or less than a predetermined threshold threshold value. The position detection system is characterized in that the beacon ID for position determination is not updated until. Further provided is one or more switching beacon signal generators that are installed in a path that passes when the moving body moves between the two moving areas and that generate a switching beacon signal including a predetermined switching beacon ID.
The beacon ID determination storage unit of the one or more communication terminals has the highest radio wave intensity among the one or more beacon signals for position determination received after receiving the switching beacon signal having a predetermined radio wave intensity or more. If the beacon signal for position determination is stronger than a predetermined area determination threshold value, the beacon ID for position determination is stored as an area ID, and the beacon signal among the one or more beacon signals received in the determination cycle is Determining the beacon signal for position determination from the radio field intensity of the one or more beacon signals generated by the one or more beacons for position determination installed in the moving area specified by the area ID. The position detection system according to claim 1, which is characterized in that. Further provided is one or more switching beacon signal generators that are installed in a path that passes when the moving body moves between the two moving areas and that generate a switching beacon signal including a predetermined switching beacon ID.
The beacon ID determination storage unit of the one or more communication terminals has the highest radio wave intensity among the one or more beacon signals for position determination received after receiving the switching beacon signal having a predetermined radio wave intensity or more. If the beacon signal for position determination having a strong signal is equal to or greater than a predetermined area determination threshold value, the beacon ID for position determination is stored as an area ID, and the radio wave intensity of one or more beacon signals received within the determination cycle The beacon signal for position determination that determines the beacon signal for position determination from the position determination beacon generator that generates the beacon signal for position determination determined as the moving area specified by the area ID in the final stage of the determination cycle. When the moving area in which is installed matches the beacon area for the position determination, the beacon ID of the beacon signal for position determination is used as the beacon ID for position determination. Position detection system according to claim 1, characterized in that new to. Further provided is one or more switching beacon signal generators that are installed in a path that passes when the moving body moves between the two moving areas and that generate a switching beacon signal including a predetermined switching beacon ID.
The beacon ID determination storage unit of the one or more communication terminals has the highest radio wave intensity among the one or more beacon signals for position determination received after receiving the switching beacon signal having a predetermined radio wave intensity or more. If the beacon signal for position determination having a strong signal is equal to or greater than a predetermined area determination threshold value, the beacon ID for position determination is stored as an area ID, and the radio wave intensity of one or more beacon signals received within the determination cycle Determines the beacon signal for position determination from, the area ID, the beacon ID of the determined beacon signal for position determination, and the terminal ID of the communication terminal to the position determination unit,
In the position determination unit, when the moving area determined from the beacon ID of the beacon signal for position determination and the moving area determined from the area ID match, the determined beacon signal for position determination is The position detection system according to claim 1, wherein the beacon ID of the final current position is updated by the beacon ID.   5. The limit threshold value is set so that the intensity difference does not fall below the limit threshold value in a boundary region where two or more output ranges of the beacon signal generator overlap. Position detection system described in.   The beacon ID determination storage unit, based on an average value of the radio field intensity of the plurality of beacon signals received in a predetermined measurement cycle shorter than the determination cycle within a period of one cycle of the determination cycle, the previous time. The position detection system according to any one of claims 1 to 4, which determines the radio wave intensity of the radio wave and the radio wave intensity of the current time.   The average value is obtained as a simple average of the radio field intensities of the beacon signals, or as the median of the radio field intensity of the beacon signals, the maximum value of the radio field intensity of the beacon signals. 7. The position detection system according to claim 6, wherein the position detection system obtains a simple average value of the remaining radio wave intensity excluding the minimum value.   When the intensity difference between the radio wave intensity of the beacon signal for position determination and the radio wave intensity of the other beacon signals becomes larger than a predetermined intensity difference threshold value, the beacon ID determination storage unit determines the intensity difference as described above. The position detection system according to claim 1, wherein the beacon ID of the other beacon signal generator that has become larger than the intensity difference threshold is updated as the beacon ID for the position determination.   The position detection system according to claim 1, wherein the determination cycle has a length equal to or longer than the determination cycle.   The position detection system according to claim 9, wherein the determination cycle has an adjustable length.   9. The transmitting unit immediately transmits the updated beacon ID for position determination and the terminal ID to the position determination unit when the beacon ID determination storage unit stores the update of the beacon ID for position determination. Position detection system described in. When a transmission request is issued from the position determination unit to the transmission unit in the determination cycle, the latest beacon ID for position determination stored in the beacon ID determination storage unit by the transmission unit is transmitted to the position determination unit. The transmitting unit is configured to transmit,
If the position determining unit transmits the beacon ID for position determination and the terminal ID updated from the transmitting unit before one cycle of the determining cycle expires, the position determining section may even expire the one cycle. The position detection system according to claim 11, which is configured not to issue the call origination request. When a transmission request is issued from the position determination unit to the transmission unit in the determination cycle, the latest beacon ID for position determination stored in the beacon ID determination storage unit by the transmission unit is transmitted to the position determination unit. The transmitting unit is configured to transmit,
If the beacon ID determination storage unit stores the update of the beacon ID for position determination before one period of the determination period expires, the transmission unit updates the position determination even if the transmission request is not made. The position detection system according to claim 9, wherein the beacon ID for mobile phone and the terminal ID are immediately transmitted to the position determination unit. When a transmission request is issued from the position determination unit to the transmission unit in the determination cycle, the latest beacon ID for position determination stored in the beacon ID determination storage unit by the transmission unit is transmitted to the position determination unit. The transmitting unit is configured to transmit,
Only when the beacon ID determination storage unit updates the beacon ID for position determination before one cycle of the determination period expires, the transmission unit is updated in response to the transmission request. The position detection system according to claim 9, wherein the beacon ID for position determination and the terminal ID are transmitted to the position determination unit. When a transmission request is issued from the position determination unit to the transmission unit in the determination cycle, the latest beacon ID for position determination stored in the beacon ID determination storage unit by the transmission unit is transmitted to the position determination unit. The transmitting unit is configured to transmit,
When the beacon ID for position determination transmitted from the transmitter in response to the previous transmission request and the beacon ID for position determination stored in the beacon ID determination storage unit at the time of the current transmission request are different. 10. The position detection system according to claim 9, wherein the transmission unit transmits the beacon ID and the terminal ID for position determination different from the last time to the position determination unit.   The beacon ID determination storage unit is configured such that the intensity difference of the radio wave intensities of the beacon signals for position determination adopted for determining the beacon ID for position determination is equal to or less than the limit threshold, and the beacon ID for position determination. Beacon ID for position determination when the intensity difference between the radio wave intensity of the beacon signal for position determination adopted for the determination and the radio field intensity of the other beacon signals is larger than a predetermined intensity difference threshold value. The peak hold value of the radio wave intensity of the beacon signal for position determination adopted for the determination of which of a plurality of predetermined peak hold value range, to which the peak hold value belongs When the next measured peak hold value is within the peak hold value range, the beacon ID for position determination is not updated and the peak hold value is not updated. The position detection according to claim 6, when the range is exceeded, the beacon ID of the beacon signal having the maximum radio wave intensity among the one or more beacon signals being received at that time is set as the beacon signal for position determination. system.   The peak hold value is obtained as a simple average of peak values of a plurality of radio field intensities of the plurality of beacon signals, or as a median of peak values of radio field intensities of the plurality of beacon signals, or of the plurality of beacon signals. The position detection system according to claim 16, wherein the position detection system is obtained as a simple average value of the peak hold values of the remaining radio wave intensity excluding the maximum value and the minimum value of the peak value of the radio wave intensity.