Antenna setting method and positioning system using same

Abstract

Provided are: an antenna setting method for suitably setting three antennas for use in a positioning system; and a positioning system using the same. An antenna setting method M100 includes: a first step S110 for setting, as a calibration origin O, an intermediate position where the receiving intensity from a second antenna 13B and the receiving intensity from a third antenna 13C become equal on the basis of receiving intensity; a second step S120 for installing a first antenna 13A at a first position where the respective distances from the second antenna 13B and the third antenna 13C become equal on the basis of the receiving intensity; a third step S130 for calculating, on the basis of the receiving intensity, a first distance d1 from the calibration origin O to the first antenna 13A, a second distance d2 from the calibration origin to the second antenna 13B, and a third distance d3 from the calibration origin to the third antenna 13C; and a fourth step S140 for setting, on the basis of the first distance d1, the second distance d2, and the third distance d3, coordinate data of the setting positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C.

Description

Antenna setting method and positioning system using same

[0001] The present invention relates to an antenna setting method and a positioning system using the same.

[0002] 2. Description of the Related Art Conventionally, various indoor positioning techniques have been known as systems for determining the positions of workers working in a factory.

[0003] Generally, for example, a positioning system is known in which an object equipped with a sensor device receives radio waves from three antennas and determines the position of the object based on the strength of each radio wave. Also, a positioning system is known in which three antennas generate magnetic fields and an object equipped with a magnetic sensor determines the position of the object based on the strength of each magnetic field received.

[0004] In these positioning systems, coordinate data for the installation locations of three antennas that generate radio waves or magnetic fields is set in advance, and the object equipped with a sensor device is positioned by calculating the distance between the object and each of the three antennas based on the radio wave intensity or magnetic field intensity received by the object.

[0005] JP 2013-145193 A

[0006] However, in conventional positioning systems, for antennas that generate radio waves or magnetic fields, there may be an error between the coordinate data of the preset installation position of the antenna and the position of the source of the radio waves or magnetic field generated from the antenna. For example, if the tip or center of the antenna is set as the source of the radio waves or magnetic field and the physically measured position of the tip or center is set in advance as the coordinate data of the installation position of the antenna, there may be an error between the coordinate data of the installation position of the antenna and the position of the source of the radio waves or magnetic field actually generated from the antenna.

[0007] That is, when calculating the distance between an object equipped with a sensor device and an antenna based on the radio wave intensity or magnetic field intensity received by the object, there is a problem that the object cannot be positioned with high accuracy due to the error.

[0008] Incidentally, Patent Document 1 discloses a method for positioning a three-axis magnetic field sensor of a magnetic field measuring device, in which the magnetic sensor is set so that the distance between two points is equal, but does not disclose a method for properly installing three antennas in a positioning system.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an antenna setting method for appropriately setting three antennas used in a positioning system, and a positioning system using the same.

[0010] An antenna setting method according to one aspect of the present invention is an antenna setting method for setting first, second, and third antennas used in a positioning system, the method including: a first step of setting an intermediate position where the reception strengths from the second and third antennas are equal as a calibration origin based on the reception strengths from the second and third antennas received by a sensor device; a second step of moving the sensor device from the calibration origin and installing the first antenna at an arbitrary first position where the reception strengths from the second and third antennas are equal and the distances from each antenna are equal based on the reception strengths from the second and third antennas received by the sensor device; a third step of moving the sensor device to the calibration origin and calculating a first distance to the first antenna, a second distance to the second antenna, and a third distance to the third antenna from the calibration origin based on the reception strengths from the first, second, and third antennas; and a fourth step of setting coordinate data of the installation positions of the first, second, and third antennas based on the first, second, and third distances.

[0011] According to this aspect, in a first step, an intermediate position where the reception strengths from the second antenna and the third antenna are equal is set as a calibration origin; in a second step, the sensor device is moved from the calibration origin to install the first antenna at an arbitrary first position where the distances from the second antenna and the third antenna are equal; in a third step, the sensor device is moved to the calibration origin to calculate the distances from the calibration origin to the first antenna, the second antenna, and the third antenna, respectively; and in a fourth step, coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna are set based on the first distance, the second distance, and the third distance. This makes it possible to appropriately set the coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna based on the reception strengths from the first antenna, the second antenna, and the third antenna received by the sensor device. As a result, in a positioning system including the first antenna, the second antenna, and the third antenna, the positions of the sources of radio waves and magnetic fields are set from distances calculated based on the reception strengths received from each antenna, unlike coordinate data of the installation positions based on physically measured distances, thereby enabling high-accuracy positioning of an object equipped with a receiving device.

[0012] In the above aspect, in the first step, a position where the reception strengths from the second antenna and the third antenna received by the sensor device are the same and are minimum may be set as the calibration origin.

[0013] According to this aspect, in the first step, the intermediate position where the reception strengths from the second antenna and the third antenna are equal can be more appropriately set as the calibration origin.

[0014] In the above aspect, in the second step, the sensor device may search for the first position while moving in a direction perpendicular to a line connecting the second antenna and the third antenna.

[0015] According to this aspect, in the second step, the reception strengths from the second antenna and the third antenna are more appropriately equalized, i.e., the first position at which the distances from the second antenna and the third antenna are equal can be searched for and the first antenna can be installed.

[0016] In the above aspect, the method may further include a fifth step of locating an object equipped with a sensor device at two different points positioned in a direction perpendicular to an imaginary plane configured to include the first antenna, the second antenna, and the third antenna, assuming that the first antenna, the second antenna, and the third antenna are installed in the coordinate data of the installation position set in the fourth step, and a sixth step of determining a deviation in the coordinate data of the installation position set as the position where the first antenna is installed, based on the position information of the two different points positioned in the fifth step.

[0017] According to this aspect, in the fifth step, the object equipped with the sensor device is positioned at two different points positioned in a direction perpendicular to an imaginary plane configured to include the first antenna, the second antenna, and the third antenna, and in the sixth step, the deviation of the coordinate data of the installation position set as the position where the first antenna is installed is determined based on the position information of the two different points, so that the accuracy of the coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna can be appropriately confirmed.

[0018] In the above aspect, if it is determined in the sixth step that there is a discrepancy in the coordinate data of the installation position set as the position where the first antenna is installed, the method may further include a seventh step of correcting a direction perpendicular to the imaginary plane in the coordinate data of the installation position set as the position where the first antenna is installed, based on the position information of two different points measured in the fifth step.

[0019] According to this aspect, if it is determined that there is a discrepancy in the coordinate data of the installation position of the first antenna, the seventh step corrects the direction orthogonal to the assumed plane in the coordinate data of the installation position of the first antenna based on the position information of two different points, so that the coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna can be set more appropriately. As a result, in a positioning system including the first antenna, the second antenna, and the third antenna, it is possible to position an object including a receiving device with higher accuracy.

[0020] In the above aspect, the method may further include a fifth step of locating the target equipped with the sensor device at two different points positioned in a direction parallel to an imaginary plane configured to include the first antenna, the second antenna, and the third antenna, assuming that the first antenna, the second antenna, and the third antenna are installed in the coordinate data of the installation position set in the fourth step, and a sixth step of determining a deviation in the coordinate data of the installation position set as the position where the second antenna and the third antenna are installed, based on the position information of the two different points positioned in the fifth step.

[0021] According to this aspect, in the fifth step, the object equipped with the sensor device is positioned at two different points in a direction parallel to an imaginary plane configured to include the first antenna, the second antenna, and the third antenna, and in the sixth step, the deviation of the coordinate data of the installation positions of the second antenna and the third antenna is determined based on the position information of the two different points, so that the accuracy of the coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna can be appropriately confirmed.

[0022] In the above aspect, if it is determined in the sixth step that there is a discrepancy in the coordinate data of the installation positions set as the positions where the second antenna and the third antenna are installed, the method may further include a seventh step of correcting a direction perpendicular to the imaginary plane in the coordinate data of the installation positions set as the positions where the second antenna and the third antenna are installed, based on the position information of two different points measured in the fifth step.

[0023] According to this aspect, if it is determined that there is a discrepancy in the coordinate data of the installation positions of the second antenna and the third antenna, the direction perpendicular to the assumed plane in the coordinate data of the installation positions of the second antenna and the third antenna is corrected based on the position information of two different points in the seventh step, so that the coordinate data of the installation positions of the first antenna, the second antenna, and the third antenna can be set more appropriately. As a result, in a positioning system including the first antenna, the second antenna, and the third antenna, it is possible to position an object including a receiving device with higher accuracy.

[0024] In the above aspect, the first antenna, the second antenna, and the third antenna may have coils that generate magnetic fields, and the sensor device may include a coil that can receive the magnetic fields generated by the first antenna, the second antenna, and the third antenna.

[0025] According to this aspect, the sensor device, as a magnetic sensor device, calculates the distance to each antenna based on the magnetic field strength received from the first antenna, the second antenna, and the third antenna, and thereby can appropriately set the position of the source of the magnetic field in the first antenna, the second antenna, and the third antenna as coordinate data of the installation position of the first antenna, the second antenna, and the third antenna.

[0026] A positioning system according to one aspect of the present invention locates a target equipped with a sensor device capable of receiving radio waves or magnetic fields from the first antenna, the second antenna, and the third antenna set by the above antenna setting method.

[0027] According to this aspect, the first antenna, the second antenna, and the third antenna, whose installation position coordinate data has been appropriately set by the above-mentioned antenna setting method, are used to locate the object equipped with the sensor device, so that the object equipped with the receiving device can be located with high accuracy.

[0028] According to the present invention, it is possible to provide an antenna setting method for appropriately setting three antennas used in a positioning system, and a positioning system using the same.

[0029] 1 is a system configuration diagram showing an overview of a positioning system 1 according to a first embodiment of the present invention. FIG. 2 is a functional block diagram showing each function in an antenna setting system 100 corresponding to the procedure of an antenna setting method according to a first embodiment of the present invention. FIG. 3 is a diagram showing a state in which an intermediate position where the reception strengths from the second antenna 13B and the third antenna 13C are equal is set as a calibration origin O. FIG. 4 is a diagram showing a state in which a first antenna 13A is installed at an arbitrary position where the distances from the second antenna 13B and the third antenna 13C are equal. FIG. 5 is a diagram showing a state in which a first distance d1 to the first antenna 13A, a second distance d2 to the second antenna 13B, and a third distance d3 to the third antenna 13C are calculated from the calibration origin O. FIG. 6 is a flowchart showing the processing flow of an antenna setting method M100 according to a first embodiment of the present invention. FIG. 7 is a diagram showing a state in which an object equipped with a receiving tag 21 is positioned using the first antenna 13A, the second antenna 13B, and the third antenna 13C. FIG. 8 is a diagram showing a specific example in which coordinate data of the installation position of the first antenna 13A set using the antenna setting method described in the first embodiment is offset in the Z-axis direction. 10A and 10B are diagrams showing other specific examples of offsetting the coordinate data of the installation position of the first antenna 13A set using the antenna setting method described in the first embodiment in the Z-axis direction.

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that each embodiment described below is merely a specific example for carrying out the present invention and is not intended to limit the scope of the present invention. Furthermore, to facilitate understanding of the description, the same components in each drawing will be designated by the same reference numerals wherever possible, and duplicate descriptions may be omitted.

[0031] 1 is a system configuration diagram showing an overview of a positioning system 1 according to a first embodiment of the present invention. As shown in Fig. 1, the positioning system 1 includes a transmitting PC (personal computer) 11, a control unit 12, a first antenna 13A, a second antenna 13B, a third antenna 13C, a receiving TAG (sensor device) 21, and a receiving PC 22.

[0032] The PC 11 on the transmitting side sends instructions regarding the driving of the first antenna 13A, the second antenna 13B, and the third antenna 13C to the control unit 12. For example, the PC 11 on the transmitting side may send to the control unit 12 a driving pattern including the driving timing and magnetic field strength for generating a magnetic field in the first antenna 13A, the second antenna 13B, and the third antenna 13C.

[0033] The control unit 12 drives the first antenna 13A, the second antenna 13B, and the third antenna 13C to generate a magnetic field, based on a drive pattern from the transmitting PC 11. Specifically, the control unit 12 controls the first antenna 13A, the second antenna 13B, and the third antenna 13C so that a current flows through the coils of the first antenna 13A, the second antenna 13B, and the third antenna 13C, respectively, to generate a magnetic field in the first antenna 13A, the second antenna 13B, and the third antenna 13C, in that order.

[0034] The receiving tag 21 receives magnetic fields from the first antenna 13A, the second antenna 13B, and the third antenna 13C. For example, the receiving tag 21 includes a three-axis coil arranged in the X-axis, Y-axis, and Z-axis directions, and receives the magnetic fields from the first antenna 13A, the second antenna 13B, and the third antenna 13C by the three-axis coil.

[0035] The receiving tag 21 includes an MCU (Micro Controller Unit) and calculates the magnetic field strength from each of the first antenna 13A, the second antenna 13B, and the third antenna 13C. For example, the magnetic field strength (RSSI: Received Signal Strength Indicator) in the receiving tag 21 is calculated by combining RSSI_x, the X-axis component, RSSI_y, and the Z-axis component, RSSI_z, of the three-axis coil, as follows: ２ +RSSI_y ２ +RSSI_z ２ ) may be calculated.

[0036] The receiving tag 21 calculates the magnetic field strength (RSSI) from each of the first antenna 13A, second antenna 13B, and third antenna 13C, and transmits it to the receiving PC 22 via a wireless network such as Bluetooth (registered trademark).

[0037] The receiving PC 22 calculates the distance between the receiving TAG 21 and each of the first antenna 13A, second antenna 13B, and third antenna 13C based on the magnetic field strength (RSSI) from the first antenna 13A, second antenna 13B, and third antenna 13C calculated by the receiving TAG 21.

[0038] Specifically, an application is installed in the receiving PC 22, and based on the characteristic that magnetic field strength (RSSI) attenuates as the cube of distance, the application calculates the distance between the receiving tag 21 and each of the first antenna 13A, second antenna 13B, and third antenna 13C. The application may then locate the receiving tag 21 based on the distance from each of the first antenna 13A, second antenna 13B, and third antenna 13C.

[0039] Here, the magnetic field strength (RSSI) is calculated by the MCU of the receiving tag 21, and the distance between the receiving tag 21 and each of the first antenna 13A, second antenna 13B, and third antenna 13C is calculated by an application on the receiving PC 22, but this is not limited to this. For example, all or part of the magnetic field strength (RSSI) calculated by the MCU of the receiving tag 21 may be calculated by an application on the receiving PC 22, or conversely, the distance calculated by the application on the receiving PC 22 may be calculated by the MCU of the receiving tag 21.

[0040] Furthermore, although the application is installed on the receiving PC 22, it is not limited to a PC and may be installed on, for example, a mobile terminal equipped with the receiving TAG 21, so that the receiving TAG 21 and the application are integrated. In this case, a screen for displaying the positioning results of the receiving TAG 21 may be provided on the mobile terminal, or a separate display device for displaying the results may be provided.

[0041] [Method of Setting Antennas] In the positioning system 1 described above with reference to Fig. 1, it is necessary to set the first antenna 13A, the second antenna 13B, and the third antenna 13C in advance. An antenna setting method for setting the first antenna 13A, the second antenna 13B, and the third antenna 13C will be described in detail below.

[0042] 2 is a functional block diagram showing the functions of the antenna setting system 100 corresponding to the steps of the antenna setting method according to the first embodiment of the present invention. As shown in FIG. 2, the antenna setting system 100 includes a receiving unit 110, a calibration origin setting unit 120, an antenna installation unit 130, a distance calculation unit 140, and an antenna position setting unit 150.

[0043] In addition, each means constituting the antenna setting system 100 corresponding to the steps of the antenna setting method may be realized, for example, manually by an operator, or may be realized in whole or in part automatically using an antenna setting device.

[0044] The receiving means 110 receives magnetic fields from the first antenna 13A, the second antenna 13B, and the third antenna 13C. For example, the magnetic fields generated by the control unit 12 in the first antenna 13A, the second antenna 13B, and the third antenna 13C are received by the receiving tag 21.

[0045] The calibration origin setting means 120 sets, as the calibration origin, an intermediate position where the reception strength from the second antenna 13B and the third antenna 13C is equal, based on the reception strength from the second antenna 13B and the third antenna 13C received by the receiving means 110. For example, on a line connecting the second antenna 13B and the third antenna 13C, a position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal is set as the calibration origin.

[0046] The antenna installation means 130 moves the receiving tag 21 from the calibration origin set by the calibration origin setting means 120, and installs the first antenna 13A at a position (first position) where the distance from each of the second antenna 13B and the third antenna 13C is equal, based on the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21. For example, the receiving tag 21 may be moved from the calibration origin in a direction substantially perpendicular to (so as to be perpendicular to) the line connecting the second antenna 13B and the third antenna 13C, and the first antenna 13A may be installed at a position near the position where the first antenna 13A is installed (the position where it is to be installed) where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal.

[0047] The distance calculation means 140 moves (places) the receiving tag 21 at the calibration origin and calculates a first distance from the calibration origin to the first antenna 13A, a second distance to the second antenna 13B, and a third distance to the third antenna 13C based on the reception intensities from the first antenna 13A, the second antenna 13B, and the third antenna 13C. For example, based on the characteristic that magnetic field strength (RSSI) attenuates as the cube of distance, the first distance, the second distance, and the third distance are calculated from the reception intensities from the first antenna 13A, the second antenna 13B, and the third antenna 13C received by the receiving tag 21 at the calibration origin.

[0048] The antenna position setting means 150 sets the positions where the first antenna 13A, the second antenna 13B, and the third antenna 13C are installed, based on the first distance, the second distance, and the third distance calculated by the distance calculation means 140. For example, the antenna position setting means 150 may use the calibration origin as the origin of the XYZ coordinate system, and register the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C as coordinates in the XYZ coordinate system.

[0049] 3 is a diagram showing how an intermediate position where the reception strength from the second antenna 13B and the third antenna 13C are equal is set as the calibration origin O. As shown in Fig. 3, using the receiving tag 21, a position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal is set as the calibration origin O as the intermediate position between the second antenna 13B and the third antenna 13C. In other words, the second distance d2 from the calibration origin O to the second antenna 13B and the third distance d3 from the calibration origin O to the third antenna 13C are equal.

[0050] Specifically, a position on the line connecting the second antenna 13B and the third antenna 13C where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is the same may be searched for. In other words, the position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is the same and is the smallest is set as the calibration origin O.

[0051] Note that the calibration origin setting means 120 may be an antenna setting device that searches for an intermediate position where the reception strength from the second antenna 13B and the third antenna 13C are equal while the operator moves the receiving tag 21, or it may be an antenna setting device that automatically searches for some or all of the intermediate positions. The antenna setting device may be configured to include, for example, a linear rail that connects the second antenna 13B and the third antenna 13C, and to search for a position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal while the receiving tag 21 is moved on the rail.

[0052] 4 is a diagram showing the state in which the first antenna 13A is installed at a position where the distances from the second antenna 13B and the third antenna 13C are equal. As shown in FIG. 4, the receiving tag 21 is moved from the calibration origin O to identify a position (first position) near the position where the first antenna 13A is installed (the position where it is to be installed) where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal, and the first antenna 13A is installed. In other words, the distance d12 from the first antenna 13A to the second antenna 13B is equal to the distance d13 from the first antenna 13A to the third antenna 13C.

[0053] Specifically, the antenna installation means 130 may search for a position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is the same as that from the second antenna 13B and the third antenna 13C while moving the receiving tag 21 parallel to the line connecting the second antenna 13B and the third antenna 13C. Here, the calibration origin O is located midway between the second antenna 13B and the third antenna 13C, and the distance d12 from the first antenna 13A to the second antenna 13B is equal to the distance d13 from the first antenna 13A to the third antenna 13C. Therefore, the line connecting the calibration origin O and the first antenna 13A is the perpendicular bisector of an isosceles triangle formed by the first antenna 13A, the second antenna 13B, and the third antenna 13C. In other words, the line connecting the calibration origin O and the first antenna 13A is perpendicular to the line connecting the second antenna 13B and the third antenna 13C.

[0054] As the antenna installation means 130, an operator may move the receiving tag 21 while searching for a position where the distance from the second antenna 13B and the third antenna 13C is equal, or an antenna setting device that automatically searches for some or all of the positions may be used. The antenna setting device may be configured to include, for example, a linear rail that is parallel to the line connecting the second antenna 13B and the third antenna 13C, and to move the receiving tag 21 on the rail while searching for a position where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving tag 21 is equal.

[0055] 5 is a diagram showing how a first distance d1 from the calibration origin O to the first antenna 13A, a second distance d2 from the second antenna 13B, and a third distance d3 from the third antenna 13C are calculated. As shown in Fig. 5, a receiving tag 21 is installed at the calibration origin O, and the distance calculation means 140 calculates the first distance d1, the second distance d2, and the third distance d3 based on the reception strengths of the signals received by the receiving tag 21 from the first antenna 13A, the second antenna 13B, and the third antenna 13C.

[0056] Specifically, the distance calculation means 140 calculates the first distance d1, the second distance d2, and the third distance d3 from the reception strengths from the first antenna 13A, the second antenna 13B, and the third antenna 13C received by the receiving TAG 21 at the calibration origin O, based on the characteristic that the magnetic field strength (RSSI) attenuates as the cube of the distance.

[0057] The antenna position setting means 150 may set the calibration origin O as the origin of the XYZ coordinate system, set the X axis along the straight line connecting the second antenna 13B and the third antenna 13C, and register the second antenna 13B and the third antenna 13C as coordinates in the XYZ coordinate system based on the second distance d2 and the third distance d3. The antenna position setting means 150 may also set the Y axis in the direction from the calibration origin O toward the first antenna 13A, and register the first antenna 13A as a coordinate in the XYZ coordinate system based on the first distance d1.

[0058] [Processing Flow of Antenna Setting Method] Figure 6 is a flowchart showing the processing flow of an antenna setting method M100 according to the first embodiment of the present invention. As shown in Figure 6, the antenna setting method M100 includes steps S110 to S140, and each step is executed by the antenna setting system 100. Specifically, each step is executed manually by an operator and / or automatically by an antenna installation device using a receiving tag 21 capable of receiving magnetic field intensities from the first antenna 13A, the second antenna 13B, and the third antenna 13C that constitute the positioning system 1.

[0059] In step S110, the calibration origin setting means 120 sets the position on the straight line connecting the second antenna 13B and the third antenna 13C where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving TAG 21 is the same as the calibration origin O, which is the midpoint between the second antenna 13B and the third antenna 13C (first step).

[0060] In step S120, the antenna installation means 130 moves the receiving TAG 21 from the calibration origin O, identifies a position (first position) where the reception strength from the second antenna 13B and the third antenna 13C received by the receiving TAG 21 is the same, and installs the first antenna 13A (second step).

[0061] In step S130, a receiving tag 21 is placed at the calibration origin O, and the distance calculation means 140 calculates the first distance d1, the second distance d2, and the third distance d3 from the reception strengths from the first antenna 13A, the second antenna 13B, and the third antenna 13C received by the receiving tag 21 (third step).

[0062] In step S140, the antenna position setting means 150 sets the calibration origin O as the origin of the XYZ coordinate system, and registers the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C as coordinates in the XYZ coordinate system based on the first distance d1, the second distance d2, and the third distance d3.

[0063] In this way, by corresponding the first antenna 13A, the second antenna 13B, and the third antenna 13C set on the XYZ coordinate system with the calibration origin O as the origin to three-dimensional coordinates in real space, it is possible to properly position an object equipped with a receiving TAG 21 in the real space.

[0064] As described above, according to the antenna setting system 100 and antenna setting method M100 of the first embodiment of the present invention, the calibration origin O is set to an intermediate position where the reception strength from the second antenna 13B and the third antenna 13C are equal based on the magnetic field strength received by the receiving tag 21, the receiving tag 21 is moved from the calibration origin O, and the first antenna 13A is installed at a first position where the distance from each of the second antenna 13B and the third antenna 13C is equal based on the magnetic field strength received by the receiving tag 21, and further, the receiving tag 21 is installed at the calibration origin O, and the first distance d1, the second distance d2, and the third distance d3 are calculated based on the magnetic field strength received by the receiving tag 21, and coordinate data for the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C are set based on these distances. That is, coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C can be appropriately set based on the distance calculated based on the magnetic field strength received by the receiving tag 21. As a result, in the positioning system 1 equipped with the first antenna 13A, the second antenna 13B, and the third antenna 13C, unlike coordinate data of the installation positions based on physically measured distances, the position of the magnetic field source is set from the distance calculated based on the magnetic field strength received from each antenna, and therefore, the object equipped with the receiving tag 21 can be positioned with high accuracy.

[0065] In this embodiment, the first antenna 13A, the second antenna 13B, and the third antenna 13C generate magnetic fields, and the distances to the first antenna 13A, the second antenna 13B, and the third antenna 13C are calculated based on the magnetic field strength received by the receiving tag 21. However, this is not limited to this. For example, radio waves may be used, and radio signals may be transmitted from the first antenna 13A, the second antenna 13B, and the third antenna 13C, and the distances to the first antenna 13A, the second antenna 13B, and the third antenna 13C may be calculated based on the radio wave strength received by the receiving tag 21.

[0066] <Second embodiment> Next, in a second embodiment of the present invention, a method for confirming the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C set using the antenna setting method described in the first embodiment will be described.

[0067] 7 is a diagram showing how a target equipped with a receiving tag 21 is located using the first antenna 13A, the second antenna 13B, and the third antenna 13C. As shown in FIG. 7, it is assumed that the Z axis is set in the horizontal direction, and the first antenna 13A, the second antenna 13B, and the third antenna 13C are set on the XY plane.

[0068] As a specific example, an object having a receiving tag 21 is moved parallel from position P1 to position P2 on a table placed horizontally along the Z axis. In this case, the object having the receiving tag 21 is positioned using the first antenna 13A, the second antenna 13B, and the third antenna 13C (fifth step), and the height position (y1) at position P1 and the height position (y2) at position P2 are determined (sixth step).

[0069] If y1=y2, it is determined that the position set as the coordinate data of the installation position of the first antenna 13A is set appropriately (sixth step).

[0070] On the other hand, if y1=y2 is not satisfied, it is determined that the position set as the coordinate data of the installation position of the first antenna 13A is set incorrectly (step 6), and is offset in the Z-axis direction (step 7).

[0071] 8 is a diagram showing a specific example of offsetting the coordinate data of the installation position of the first antenna 13A set using the antenna setting method described in the first embodiment in the Z-axis direction. As shown in Fig. 8, an object equipped with the receiving tag 21 is translated from position P1 to position P2, and the positioning result at this time is that the height position (y1) at position P1 is different from the height position (y2) at position P2.

[0072] For example, if the Z coordinate position at position P1 of the positioned receiving TAG21 is z1, the Z coordinate position at position P2 is z2, the difference in height between positions P1 and P2 is Δy = y2 - y1, and the angle is Δθ, then the offset amount Δz in the Z-axis direction of the first antenna 13A (Y coordinate position y0) can be calculated using the following (Equation 1) and (Equation 2).

[0073]

[0074] 8, two right-angled triangles having an angle Δθ are formed. By utilizing the fact that the two right-angled triangles are similar to each other, the offset amount Δz of the first antenna 13A (Y coordinate position y0) in the Z-axis direction can be calculated using the following (Equation 3) and (Equation 4).

[0075]

[0076] The method for calculating the offset amount Δz of the first antenna 13A (Y coordinate position y0) in the Z-axis direction is not limited to this.

[0077] 9 is a diagram showing another specific example of offsetting the coordinate data of the installation position of the first antenna 13A in the Z-axis direction, which is set using the antenna setting method described in the first embodiment. As shown in Fig. 9, for example, if the distance from the coordinate data of the installation position of the first antenna 13A to position P1 on the positioned receiving TAG 21 is d1 and the distance to position P2 is d2, the offset amount Δz of the first antenna 13A (Y coordinate position y0) in the Z-axis direction can be calculated using the following (Equation 5), (Equation 6), and (Equation 7).

[0078]

[0079] As described above, according to the method for confirming the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C of the second embodiment of the present invention, an object having a receiving tag 21 is positioned at two different points (positions P1 and P2) in the Z-axis direction perpendicular to an assumed X-Y plane configured to include the first antenna 13A, the second antenna 13B, and the third antenna 13C. Then, based on the height position (y1) at position P1 and the height position (y2) at position P2, the positional deviation set as the coordinate data of the installation position of the first antenna 13A is determined, so that the accuracy of the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C can be appropriately confirmed.

[0080] Furthermore, when it is determined that the position set as the coordinate data of the installation position of the first antenna 13A is set to be misaligned, an offset amount Δz in the Z-axis direction can be appropriately calculated as the coordinate data of the installation position of the first antenna 13A, as described with reference to Figures 7 and 8. As a result, it is possible to more appropriately set the coordinate data of the installation positions of the first antenna 13A, the second antenna 13B, and the third antenna 13C, and by using these, it is possible to more accurately locate the target equipped with the receiving tag 21.

[0081] Although the method described here involves confirming and offsetting the Z-axis position set as coordinate data for the installation position of the first antenna 13A, the present invention is not limited to this. For example, an object equipped with the receiving tag 21 is moved parallel to a table installed horizontally along the X-axis. In this case, the object equipped with the receiving tag 21 is positioned using the first antenna 13A, the second antenna 13B, and the third antenna 13C, and the height positions at two different points are compared. This makes it possible to confirm the deviation in the Z-axis position set as coordinate data for the installation positions of the second antenna 13B and the third antenna 13C.

[0082] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of each embodiment, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those illustrated and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined with each other.

[0083] [Additional Note] An antenna setting method (M100) for setting a first antenna (13A), a second antenna (13B), and a third antenna (13C) used in a positioning system (1), comprising: a first step (S110) of setting an intermediate position where the reception strengths from the second antenna (13B) and the third antenna (13C) are equal as a calibration origin (O) based on the reception strengths from the second antenna (13B) and the third antenna (13C) received by a sensor device (21); and a second step (S120) of moving the sensor device (21) from the calibration origin (O) and installing the first antenna (13A) at a first position where the distances from the second antenna (13B) and the third antenna (13C) are equal, based on the reception strengths from the second antenna (13B) and the third antenna (13C) received by the sensor device (21); The antenna setting method (M100) includes: a third step (S130) of moving the sensor device (21) to the calibration origin (O), and calculating a first distance (d1) from the calibration origin (O) to the first antenna (13A), a second distance (d2) to the second antenna (13B), and a third distance (d3) to the third antenna (13C) based on the reception intensities from the first antenna (13A), the second antenna (13B), and the third antenna (13C); and a fourth step (S140) of setting coordinate data of installation positions of the first antenna (13A), the second antenna (13B), and the third antenna (13C) based on the first distance (d1), the second distance (d2), and the third distance (d3).

[0084] 1...positioning system, 11, 22...PC, 12...control unit, 13A to 13C...antenna, 21...receiving TAG (sensor device), 100...antenna setting system, 110...receiving means, 120...calibration origin setting means, 130...antenna installation means, 140...distance calculation means, 150...antenna position setting means, M100...antenna setting method, S110 to S140...each step of antenna setting method M100

Claims

1. An antenna setting method for setting a first antenna, a second antenna, and a third antenna used in a positioning system, comprising: a first step of setting, based on reception intensities from the second antenna and the third antenna received by a sensor device, an intermediate position where the reception intensities from the second antenna and the third antenna are equal as a calibration origin; a second step of moving the sensor device from the calibration origin and installing the first antenna at a first position where distances from the second antenna and the third antenna are equal based on the reception intensities from the second antenna and the third antenna received by the sensor device; a third step of moving the sensor device to the calibration origin and calculating a first distance from the calibration origin to the first antenna, a second distance from the calibration origin to the second antenna, and a third distance from the calibration origin to the third antenna based on reception intensities from the first antenna, the second antenna, and the third antenna; and a fourth step of setting coordinate data of installation positions of the first antenna, the second antenna, and the third antenna based on the first distance, the second distance, and the third distance.

2. The antenna setting method according to claim 1, wherein in the first step, a position where reception intensities from the second antenna and the third antenna received by the sensor device are the same and minimum is set as the calibration origin.

3. The antenna setting method according to claim 1, wherein in the second step, the first position is searched while moving the sensor device in a direction orthogonal to a straight line connecting the second antenna and the third antenna.

4. Further comprising: a fifth step of positioning an object including a sensor device at two points having different positions in a direction orthogonal to an assumed plane configured to include the first antenna, the second antenna, and the third antenna, assuming that the first antenna, the second antenna, and the third antenna are installed at the coordinate data of the installation positions set in the fourth step; and a sixth step of determining a deviation of the coordinate data of the installation position set as the position where the first antenna is installed based on position information of the two different points positioned in the fifth step.

5. If it is determined that there is a deviation in the coordinate data of the installation position set as the position where the first antenna is installed in the sixth step, a seventh step of correcting the direction orthogonal to the assumed plane in the coordinate data of the installation position set as the position where the first antenna is installed based on the position information of two different points measured in the fifth step is further included. The antenna setting method according to claim 4.

6. Assuming that the first antenna, the second antenna, and the third antenna are installed at the coordinate data of the installation position set in the fourth step, at two points with different positions in a direction parallel to the assumed plane configured to include the first antenna, the second antenna, and the third antenna, a fifth step of positioning a target equipped with a sensor device; and a sixth step of determining a deviation in the coordinate data of the installation position set as the position where the second antenna and the third antenna are installed based on the position information of two different points measured in the fifth step are further included. The antenna setting method according to claim 1.

7. If it is determined that there is a deviation in the coordinate data of the installation position set as the position where the second antenna and the third antenna are installed in the sixth step, a seventh step of correcting the direction orthogonal to the assumed plane in the coordinate data of the installation position set as the position where the second antenna and the third antenna are installed based on the position information of two different points measured in the fifth step is further included. The antenna setting method according to claim 6.

8. The first antenna, the second antenna, and the third antenna have coils that generate a magnetic field, and the sensor device includes a coil capable of receiving the magnetic field generated by the first antenna, the second antenna, and the third antenna. The antenna setting method according to claim 1.

9. A positioning system for positioning a target equipped with a sensor device capable of receiving radio waves or a magnetic field from the first antenna, the second antenna, and the third antenna set by the antenna setting method according to any one of claims 1 to 8.

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