JP7361085B2 - Positioning system, management device, positioning method and program - Google Patents

Description

The present invention relates to a positioning system, a management device, a positioning method, and a program.

Conventionally, in areas such as indoors where radio waves from GNSS satellites are difficult to reach, the positioning target device (hereinafter also referred to as "target device") is connected to multiple reference devices installed at known position coordinates. A system is known that transmits and receives wireless media such as radio waves, sound waves, and light in a line-of-sight environment (LOS environment) between (For example, see Patent Document 1).

International Publication No. 2018/155437

In the conventional system that utilizes transmission and reception of wireless media such as radio waves in a line-of-sight environment (LOS environment), there is a problem of simplifying the number of steps required to install a plurality of reference devices.

A positioning system according to one aspect of the present invention includes a positioning target device and a plurality of reference devices installed at mutually different known position coordinates, and a positioning system between the positioning target device and the plurality of reference devices. This is a positioning system that performs positioning by transmitting and receiving positioning signals using a wireless medium and calculating the position coordinates of the device to be positioned using an algorithm based on the results of the transmission and reception. This positioning system includes a coordinate origin setting unit that sets the origin of the orthogonal coordinate system so that the installation position where the first reference device is installed is located on the vertical coordinate axis of the orthogonal coordinate system used for positioning. and the second reference device is installed so that the installation position of the second reference device is located on a virtual vertical plane including one of the two horizontal coordinate axes of the orthogonal coordinate system and the vertical coordinate axis. a horizontal coordinate axis setting unit that sets two horizontal coordinate axes; and transmission and reception of positioning signals via the wireless medium between the first reference device and the second reference device. The distance between the second reference device and the second reference device is measured, and based on the distance measurement result and the height measurement result of the second reference device, the distance between the second reference device and the second reference device is determined based on the distance measurement result and the height measurement result of the second reference device. A first coordinate determination unit that determines the coordinates of the installation position of the reference device, and a third or subsequent reference device and each of the other reference devices including the first reference device and the second reference device. A plurality of distances between the third and subsequent reference devices and each of the other reference devices are measured by transmitting and receiving positioning signals using the wireless medium between them, and the results of the measurement of the plurality of distances and the three reference devices are a second coordinate determination unit that determines the coordinates of the installation positions of the third and subsequent reference devices in the two horizontal coordinate axes of the orthogonal coordinate system based on the measurement results of the heights of the third and subsequent reference devices; Equipped with

A device according to another aspect of the present invention is a reference device that can be used in the positioning system, and includes the coordinate origin setting section, the horizontal coordinate axis setting section, the first coordinate determining section, and the second coordinate determining section. The device includes a determining unit, and a storage unit that stores information on coordinates of installation positions of the plurality of reference devices in the orthogonal coordinate system.

A method according to still another aspect of the present invention includes transmitting and receiving positioning signals using a wireless medium between a positioning target device and a plurality of reference devices installed at mutually different known position coordinates, and transmitting and receiving positioning signals using a wireless medium. This is a positioning method in which the position coordinates of the device to be positioned are calculated using an algorithm based on the above algorithm. This positioning method includes setting the origin of the orthogonal coordinate system so that the installation position where the first reference device is installed is located on the vertical coordinate axis of the orthogonal coordinate system used for positioning; The two horizontal coordinate axes are arranged so that the installation position where the second reference device is installed is located on a virtual vertical plane that includes one of the two horizontal coordinate axes of the orthogonal coordinate system and the vertical coordinate axis. and transmitting and receiving a positioning signal between the first reference device and the second reference device using the wireless medium, the first reference device and the second reference device and determine the installation position of the second reference device on the one horizontal coordinate axis based on the distance measurement result and the height measurement result of the second reference device. determining coordinates; and transmitting and receiving positioning signals via the wireless medium between the third and subsequent reference devices and each of the other reference devices including the first reference device and the second reference device. A plurality of distances are measured between the third and subsequent reference devices and each of the other reference devices, and the measurement results of the plurality of distances and the heights of the third and subsequent reference devices are measured. and determining the coordinates of the installation positions of the third and subsequent reference devices in the two horizontal coordinate axes of the orthogonal coordinate system based on the results.

A program according to still another aspect of the present invention is a program executed on a computer or processor included in the management device. This program includes a program code for communicating with each of the plurality of reference devices via a communication network, and an installation position where the first reference device is installed on the vertical coordinate axis of the orthogonal coordinate system used for the positioning. The program code for setting the origin of the orthogonal coordinate system and the installation position where the second reference device is installed are located on one of the two horizontal coordinate axes of the orthogonal coordinate system. between a program code for setting the two horizontal coordinate axes so as to be located on a virtual vertical plane including the coordinate axes and the vertical coordinate axes, and the first reference device and the second reference device; The distance between the first reference device and the second reference device is measured by transmitting and receiving a positioning signal using the wireless medium, and the distance measurement result and the height of the second reference device are combined. a program code for determining the coordinates of the installation position of the second reference device in the one horizontal coordinate axis based on the measurement results of the third and subsequent reference devices and the first reference device; By transmitting and receiving positioning signals using the wireless medium between the device and each of the other reference devices including the second reference device, the communication between the third and subsequent reference devices and each of the other reference devices , and based on the measurement results of the plurality of distances and the measurement results of the heights of the third and subsequent reference devices, the third reference device in the two horizontal coordinate axes of the orthogonal coordinate system is determined. The program code includes a program code for determining the coordinates of the subsequent installation positions of the reference devices, and a program code for storing information on the position coordinates of each of the plurality of reference devices.

In the positioning system, the management device, the positioning method, and the program, the origin of the orthogonal coordinate system may be the installation position of the first reference device, or the location where the plurality of reference devices are installed. It may be an intersection point between the horizontal bottom surface of the positioning target space and a virtual vertical line passing through the installation position of the first reference device.

In the positioning system, the management device, the positioning method, and the program, the wireless medium may be UWB (ultra wideband) radio waves.

In the positioning system, the management device, the positioning method, and the program, the distance between the first reference device and the second reference device and the reference for the third and subsequent devices are determined by transmitting and receiving the positioning signal. The method for measuring the distance between the device and the other reference device may be a ToF (Time of Flight) method.

In the positioning system, the management device, the positioning method, and the program, the time synchronization or time difference between the plurality of reference devices is managed, and the first reference device and the second reference device are controlled by transmitting and receiving the positioning signal. The method for measuring multiple distances between the eye reference device and each of the third reference devices is the ToF (Time of Flight) method, and the distance between the fourth and subsequent reference devices and other reference devices is the ToF (Time of Flight) method. The method for measuring the plurality of distances between them may be a TDoA (Time Difference of Arrival) method.

In the positioning system, the management device, the positioning method, and the program, the plurality of reference devices are four or more reference devices whose time synchronization or time difference is managed, and the position of the device to be positioned is The coordinates are based on information on a plurality of time differences at which the positioning signal transmitted from the positioning target device is received by each of the plurality of reference devices, and information on the position coordinates of each of the plurality of reference devices. may be calculated.

In the positioning system, the management device, the positioning method, and the program, the device to be positioned may be a wireless IC tag.

The positioning system may include a management device capable of communicating with each of the plurality of reference devices via a communication network.

According to the present invention, it is possible to simplify the number of steps required to install a plurality of reference devices used for positioning using the transmission and reception of positioning signals via a wireless medium to and from a positioning target device.

FIG. 1 is an explanatory diagram showing an example of the main configuration of a positioning system according to an embodiment. FIG. 2 is a block diagram showing an example of the main configurations of a reference device, a target device, and a management device during positioning of a target device in the positioning system of FIG. 1; FIG. 2 is a block diagram showing an example of the main configurations of a reference device and a management device when a reference device is additionally installed in the positioning system of FIG. 1; FIG. 3 is an explanatory diagram showing an example of a ToF distance measurement technique that can be used to measure the distance between reference devices. 5 is a flowchart illustrating an example of a procedure for setting a coordinate system and determining position coordinates of the reference devices when installing a plurality of reference devices in the positioning system of the embodiment. FIG. 6 is a perspective view showing an example of setting a coordinate system and determining position coordinates of the second reference device when installing the first reference device and the second reference device in FIG. 5; FIG. 6 is a perspective view showing an example of determining the position coordinates of the third reference device in FIG. 5; FIG. 6 is a plan view showing an example of determining the position coordinates of the third reference device in FIG. 5; FIG. 6 is a perspective view showing an example of determining the position coordinates of the fourth reference device in FIG. 5; FIG. 6 is a plan view showing an example of determining the position coordinates of the fourth reference device in FIG. 5; 7 is a flowchart illustrating another example of the procedure for setting a coordinate system and determining position coordinates of the reference devices when installing a plurality of reference devices in the positioning system of the embodiment. FIG. 12 is a perspective view showing an example of determining the position coordinates of the fourth reference device in FIG. 11;

Embodiments of the present invention will be described below with reference to the drawings.
The positioning system according to the embodiment described in this document operates in a line-of-sight environment (LOS environment) between a tag (a device to be positioned) and a plurality of anchors (reference devices) installed at mutually different known position coordinates. ) is a system that transmits and receives positioning signals using ultra-wideband (UWB) radio waves, and calculates the position coordinates of a tag using a TDoA (time difference of arrival) algorithm based on the results of the transmission and reception.

The TDoA positioning system of this embodiment is suitable for positioning the position coordinates of a tag in an area such as an indoor area where radio waves from a GNSS satellite cannot reach or are difficult to reach. The positioning system of this embodiment is suitable for realizing a real-time positioning system (RTLS) that measures the position of a positioning target device such as a tag in real time.

In particular, the positioning system of this embodiment is a positioning system that can simplify the number of steps required to install a plurality of anchors used for positioning.

FIG. 1 is an explanatory diagram showing an example of the main configuration of a positioning system according to an embodiment of the present invention. In FIG. 1, the positioning system includes a plurality of reference devices (hereinafter referred to as "anchors") installed at mutually different known position coordinates in each of a plurality of positioning possible spaces (hereinafter also referred to as "positioning target spaces") 10A and 10B. ) 20A(1) to 20A(4) and 20B(1) to 20B(4). The positioning system may further include positioning target devices (hereinafter referred to as "target devices") 30A and 30B in the positioning possible spaces 10A and 10B, respectively. The positioning system may further include a management device 40 capable of communicating with each of the plurality of reference devices 20A(1) to 20A(4) and 20B(1) to 20B(4). The management device 40 may be able to communicate with the target devices 30A and 30B.

Note that the example in FIG. 1 shows a positioning system that measures the positions of the target devices 30A and 30B using the TDoA method; It is also possible to measure the position.

Further, in the example of FIG. 1, a case is shown in which the number of positionable spaces 10A and 10B is two, but the number of positionable spaces may be singular, or may be three or more. Further, the number of reference devices 20A(1) to 20A(4) and 20B(1) to 20B(4) in each of the positioning possible spaces 10A and 10B is 4, respectively, but the number of reference devices in the positioning possible space is 5. It may be more than that. Furthermore, although the number of target devices 30A and 30B in each positionable space 10A and 10B is one, the number of target devices in the positionable space may be two or more.

Furthermore, in the following description, when describing matters common to each of the positioning spaces 10A and 10B, they will be referred to as the positioning space 10. Also, when explaining matters common to each reference device 20A(1) to 20A(4), 20B(1) to 20B(4), reference devices 20, 20' or reference devices 20(1), 20( 2), ... is written. Moreover, when describing each target device 30A, 30B, it is described as target device 30.

The plurality of reference devices 20 are installed at a plurality of different positions in a two-dimensional or three-dimensional positionable space 10 inside a building or the like. The installation positions of the plurality of reference devices 20 differ from each other in at least one of horizontal position and height. The installation position is preferably as far away as possible within the positioning space 10. Note that a more detailed explanation of setting the coordinate system when installing the plurality of reference devices 20 and determining the position coordinates of the reference devices will be described later.

The number of reference devices 20 is set, for example, according to the algorithm of the positioning method. For example, when positioning the target device 30 in a three-dimensional space using the TDoA method, the number of reference devices 20 is, for example, four or more. Note that when positioning the target device 30 in a two-dimensional area, the number of reference devices may be three or more. Further, the number of reference devices 20 may be two or more depending on the positioning method.

For the plurality of reference devices 20, mutual time synchronization is managed by any synchronization method applicable between the devices, or mutual time difference between the devices is managed. Each of the plurality of reference devices 20 includes a time-synchronized internal clock in which mutual time synchronization is managed or an internal clock in which mutual time difference is managed.

Here, the above-mentioned "time synchronization" means synchronizing specific points in time between the plurality of reference devices 20, and may also be referred to as "time synchronization." Further, as an example of the case where the above-mentioned time synchronization is managed, for example, a common transmitting device is installed at a position where the positional relationship (for example, distance) with each of the plurality of reference devices 20 is known. An example of this method is to measure the time difference between timestamps of reception timings when a plurality of reference devices 20 receive a signal transmitted from a transmitting device, and store the time difference in the management device 40 or the like as an offset value between the reference devices. . This Offset value between the reference devices is used to correct the reception time difference (time stamp difference) between the reference devices used to calculate the distance between the target device 30 and the plurality of reference devices 20 in TDoA positioning described later. It is possible to calculate (estimate) the current position of the target device 30 without performing time synchronization between the plurality of reference devices 20. Note that, after the initial setting, the Offset value is updated at a predetermined timing (for example, at a regular timing in a predetermined cycle) by measuring the time difference between the time stamps of the reception timings of the signals from the common transmitting device. You may.

The known positional coordinates at which each of the plurality of reference devices 20 is installed are, for example, relative positional coordinates in a coordinate system set in advance in the positioning target space 10. The positional coordinates of the plurality of reference devices 20 in this embodiment may be relative positional coordinates in an orthogonal coordinate system in which the origin is set on a vertical coordinate axis passing through the installation position of any one of the reference devices 20. The positional coordinates of the plurality of reference devices 20 in a predetermined coordinate system of the positioning target space 10 can be determined by transmitting and receiving positioning signals between the reference devices as described later.

If the position coordinates of the plurality of reference devices 20 cannot be determined by transmitting and receiving positioning signals between the reference devices, which will be described later, the position coordinates of the plurality of reference devices 20 can be determined by performing a surveying operation using general surveying techniques (for example, a total station, a laser ranging sensor). You may. In addition, if some or all of the plurality of reference devices 20 are placed in an area where radio waves from GNSS satellites can be received, the known position coordinates of some or all of the reference devices 20 may be used as the GNSS receiver. You may also use the position coordinates measured in . The position coordinates in this case may be, for example, latitude, longitude, and altitude, or may be a coordinate position (X, Y, Z) in an ECEF (Earth-Centered Earth-Fixed) coordinate system in which a certain reference point is defined. There may be.

The target device 30 is, for example, an IC wireless tag (hereinafter also referred to as "tag"). The target device 30 may be a tag, a truck, a forklift, various parts, or various products. The target device 30 may be a moving device, a temporarily stopped device, or a fixedly located device.

The target device 30 transmits a positioning signal using a predetermined wireless medium to each of the plurality of reference devices 20, as shown by the solid arrow in FIG. The wireless medium used for transmitting and receiving positioning signals is a wireless medium such as radio waves, sound waves, and light. In this embodiment, UWB (ultra wideband) radio waves are used as the wireless medium. UWB is a communication technology using weak radio waves in a wide band (for example, a bandwidth of several hundred MHz centered on an arbitrary frequency in a several GHz band), and is being promoted as an international standard under IEEE 802.15.4.

The management device 40 is, for example, a cloud computer system (hereinafter also referred to as "cloud system") built on a communication network 45 such as the Internet. The management device 40 may be a server composed of a single computer device or a plurality of computer devices. Communication between the management device 40 and the plurality of reference devices 20 can be performed, for example, via a wired or wireless communication line. The communication line may be a public line or a private line.

FIG. 2 is a block diagram showing an example of the main configurations of the reference device (anchor) 20, the target device (tag) 30, and the management device 40 during positioning of the target device (tag) 30 of the positioning system in FIG.
In FIG. 2, the reference device 20 includes a UWB communication section 210, a storage section 230, and a NW communication section 240 that also functions as an information transmission section. The UWB communication unit 210 also functions as a receiving unit for positioning signals during positioning of the target device 30.

The UWB communication unit 210 is composed of, for example, a UWB wireless communication module. The UWB communication unit 210 receives, via the antenna 211, a positioning signal transmitted (transmitted) from the target device 30 using UWB radio waves when positioning the target device 30. Further, the UWB communication unit 210 outputs information included in the positioning signal received from the target device 30 and reception time information (Timestamp) of the positioning signal.

The transmission format of the positioning signal transmitted from the target device 30 includes, for example, frame control information (Frame Control), transmission sequence number (Sequence Number), target device identification information (TAG ID) that can identify the target device 30, and message identification. information (Message ID), positioning management identification information (Purpose ID), and data error recovery information (CRC). The positioning management identification information (Purpose ID) is, for example, information that can identify at least one of the purpose of positioning, the use of the positioning results, and the entity using the positioning results.

The storage unit 230 stores various information included in the positioning signal output from the UWB communication unit 210 and positioning signal reception time information (Timestamp), which is information on the transmission/reception result of the positioning signal, in association with each other.

The NW communication unit 240 communicates with the management device 40 via a wired or wireless communication line. The NW communication unit 240 transmits positioning-related information regarding the positioning of the target device 30 stored in the storage unit 230 to the management device 40. The transmission format of the positioning related information sent to the management device 40 is, for example, target device identification information (TAG ID), reference device identification information (Anchor ID) that can identify the reference device (own device) 20, and target device count information. (TAG Counter), positioning management identification information (Purpose ID), reception time information (Timestamp) of the positioning signal from the target device 30, and radio field strength and absolute time information (Epoch Time).

In FIG. 2, the target device 30 includes a UWB transmitting section 310 that also functions as a positioning signal transmitting section, and a storage section 330.

The UWB transmitter 310 is configured with, for example, a UWB wireless communication module, and transmits (emits) a positioning signal having a transmission format including the above-mentioned positioning management identification information (Purpose ID) via the antenna 311. The positioning signal is, for example, a pulse-like signal, and is periodically transmitted at predetermined time intervals.

The storage unit 330 stores information to be included in the positioning signal transmitted from the UWB transmission unit 310. Furthermore, the storage unit 330 may store positioning management identification information (Purpose ID) that is preset in the reference device 20.

In FIG. 2, the management device 40 includes a NW communication section 410, a positioning calculation section 420, and a storage section (DB) 430. The NW communication unit 410 also functions as a receiving unit for receiving information on the results of transmission and reception of positioning signals during positioning of the target device 30.

The positioning calculation unit 420 functions as a calculation unit for calculating the position coordinates of the target device 30 during positioning of the target device 30.

The NW communication unit 410 communicates with the plurality of reference devices 20 via wired or wireless communication lines. The NW communication unit 410 receives positioning-related information regarding the positioning of the target device 30 from each reference device 20 when positioning the target device 30 . The positioning related information from the reference device 20 includes, for example, target device identification information (TAG ID), reference device identification information (Anchor ID) that can identify the reference device (own device) 20, target device count information (TAG Counter), It includes positioning management identification information (Purpose ID), reception time information (Timestamp) of the positioning signal from the target device 30, and radio field strength and absolute time information (Epoch Time).

The positioning calculation unit 420 calculates and positions the current position of the target device 30 for each target device 30, for example, based on the positioning-related information received from each reference device 20. The positioning calculation unit 420 calculates the current position of the target device 30 for each positioning management identification information (Purpose ID) and for each target device 30 based on the positioning related information received from each reference device 20, and performs positioning. You may.

In the TDoA positioning system of this embodiment, the current position of the target device 30 can be calculated using, for example, the following algorithm. Here, in the positioning possible space 10A of FIG. 1 described above, the positioning signal transmitted from the target device 30A reaches four reference devices 20A (1), 20A (2), 20A (3), and 20A (4). The received times (Timestamps) are T1, T2, T3, T4, the propagation speed of the positioning signal is v [m/s], and the target device 30 and the reference device 20A(1), 20A(2), 20A(3) , 20A(4) are respectively D1, D2, D3, and D4, and the reception time difference of the positioning signal between the reference devices is ΔT12=T1-T2, ΔT13=T1-T3, ΔT14=T1-T4, ΔT23= When T2-T3, ΔT24=T2-T4, and ΔT34=T3-T4, the following relational expressions (1) to (6) hold true.

Distances D1, D2, D3, and D4, which are unknown variables, can be determined using the above relational expressions (1) to (6). These calculated distances D1, D2, D3, and D4 are the radii of four spherical surfaces whose origin is the known position coordinates of the reference devices 20A(1), 20A(2), 20A(3), and 20A(4). The current position of the target device 30 in the three-dimensional positionable space 10A can be calculated with an accuracy of several centimeters (for example, 3 to 10 cm) using any algorithm for finding the intersection.

The positioning result of the current position of the target device 30 outputted from the positioning calculation unit 420 can be used for various services of positioning management identification information (Purpose ID), for example, in the management device 40 or in various servers, reference devices, etc. can.

The storage unit (DB) 430 stores positioning-related information used for calculation by the positioning calculation unit 420 and positioning results calculated by the positioning calculation unit 420 for each positioning management identification information (Purpose ID) and for each target device 30. . Furthermore, the storage unit (DB) 430 stores positioning management identification information (Purpose ID) set in advance for each of the plurality of reference devices 20.

FIG. 3 is a block diagram showing an example of the main configurations of the reference devices (anchors) 20, 20' and the management device 40 when the reference device (anchor) 20' of the positioning system of FIG. 1 is additionally installed. Note that in FIG. 3, the reference device 20 is an existing reference device, and the reference device 20' is a newly installed reference device. Further, in FIG. 3, the same components as those in FIG. 2 described above are given the same reference numerals, and the description thereof will be omitted.

In FIG. 3, the UWB communication section 210 of the reference device 20 also functions as a positioning signal transmitting/receiving section when the reference device 20 is installed. Further, the UWB communication unit 210 of the reference device 20 transmits a positioning signal using UWB radio waves to the reference device 20' via the antenna 211 when the additional reference device 20' is installed. Further, the UWB communication unit 210 receives, via the antenna 211, a positioning signal returned from the additionally installed reference device 20'. Further, the UWB communication unit 210 of the reference device 20 transmits transmission time information (Timestamp) at which the positioning signal was transmitted to the additionally installed reference device 20', and reception time information at which the positioning signal returned from the reference device 20' was received. (Timestamp) is output.

The transmission format of the positioning signal transmitted from the reference device 20 includes, for example, frame control information (Frame Control), a transmission sequence number (Sequence Number), and reference device identification information (Anchor ID) that can identify the reference device (own device) 20. )including. The transmission format of the positioning signal transmitted from the reference device 20 may further include measurement information of the height (Z-axis coordinate) of the reference device (own device) 30 measured in advance.

The storage unit 230 of the reference device 20 stores various information included in the positioning signal output from the UWB communication unit 210, and transmission time information (Timestamp) and reception time information (Timestamp) of the positioning signal, which are information on the transmission and reception results of the positioning signal. ) are stored in association with each other. The storage unit 230 may further associate and store measurement information of the height (Z-axis coordinate) of the reference device (own device) 30 that has been measured in advance.

The NW communication unit 240 of the reference device 20 transmits positioning-related information regarding the positioning of the additionally installed reference device 20′, which is stored in the storage unit 230, to the management device 40. The transmission format of the positioning-related information transmitted to the management device 40 includes, for example, the reference device identification information (Anchor ID) that can identify the reference device (own device) 20, and the reference device that can identify the additionally installed reference device 20'. It includes identification information (Anchor ID), transmission time information (Timestamp) of the positioning signal to the additionally installed reference device 20', and reception time information (Timestamp) of the positioning signal from the additionally installed reference device 20'. The transmission format of the positioning-related information sent to the management device 40 is measurement information of the height (Z-axis coordinate) of the reference device (own device) 20 and measurement information of the height (Z-axis coordinate) of the additionally installed reference device 20. It may further include information.

In FIG. 3, the NW communication unit 410 of the management device 40 also functions as a receiving unit for information on the results of transmission and reception of positioning signals when the reference device 20 is installed.

The positioning calculation unit 420 of the management device 40 includes a coordinate origin setting unit that sets the origin of the orthogonal coordinate system used for positioning when the reference device 20' is installed, and a horizontal coordinate axis setting unit that sets the two horizontal coordinate axes of the orthogonal coordinate system. a first coordinate determination unit that determines the coordinates of the installation position of the second reference device 20′ in the positioning target space 10; and a first coordinate determination unit that determines the coordinates of the installation position of the third and subsequent reference devices in the positioning target space 10. It also functions as a second coordinate determination unit.

The positioning calculation unit 420 as a coordinate origin setting unit is configured so that the installation position where the first reference device 20 (1) is installed is located on the vertical coordinate axis (Z axis) of the orthogonal coordinate system used for positioning. , sets the origin of the Cartesian coordinate system. In the example described below, the origin of the orthogonal coordinate system is the installation position of the first reference device 20(1). The origin of the orthogonal coordinate system is defined by the horizontal bottom of the positioning target space 10 (for example, the indoor floor of the positioning target space) and the virtual vertical line passing through the installation position of the first reference device 20 (1). It may be an intersection.

The positioning calculation unit 420 as a horizontal coordinate axis setting unit determines that the installation position where the second reference device 20 (2) is installed is one of the two horizontal coordinate axes (X axis, Y axis) of the orthogonal coordinate system. Two horizontal coordinate axes (X-axis, Y-axis) are set so as to be located on a virtual vertical plane including a coordinate axis (for example, X-axis) and a vertical coordinate axis (Z-axis).

The positioning calculation unit 420 as the first coordinate determination unit is configured to transmit and receive positioning signals using UWB radio waves between the first reference device 20 (1) and the second reference device 20 (2). The distance Da12 between the eye reference device 20(1) and the second reference device 20(2) is measured, and the measurement result of the distance Da12 and the height of the second reference device 20(2) ( The coordinates of the installation position of the second reference device 20(2) in one horizontal coordinate axis (for example, the X-axis) are determined based on the measurement result Z2 of the Z-axis coordinate.

The positioning calculation unit 420 as a second coordinate determining unit is configured to operate a third or subsequent reference device 20(3), a first reference device 20(1), and a second reference device 20(2). By transmitting and receiving positioning signals using UWB radio waves with each of the reference devices 20(1) and 20(2), the third and subsequent reference devices 20(3) and the other reference devices 20(1) and 20( 2) Measure a plurality of distances Da31 and Da32 between each of them, and measure the measurement results of the plurality of distances Da31 and Da32 and the height (Z-axis coordinate) of the third and subsequent reference devices 20 (3) Based on the result Z3, the coordinates of the installation positions of the third and subsequent reference devices 20(3) in the two horizontal coordinate axes (X-axis, Y-axis) of the orthogonal coordinate system are determined.

FIG. 4 is an explanatory diagram showing an example of a ToF distance measurement technique that can be used to measure the distance between the reference devices 20(1) and 20(2). FIG. 4 is an example of measuring the distance D12 [m] between two reference devices 20(1) and 20(2) in a line-of-sight environment (LOS environment). In FIG. 4, the first reference device 20(1) as an initiator transmits (emits) a positioning signal using UWB radio waves, and then the second reference device 20(2) as a responder responds to the positioning signal. Let Tloop[s] be the time taken to receive the response signal, and Treply[s] be the time taken from when the second reference device 20(2) receives the positioning signal to when it transmits (originates) the response signal. Then, the propagation time ToF[s] for propagating in one direction over the distance between the reference devices 20(1) and 20(2) is expressed by the following equation (7).

By multiplying the propagation time ToF [s] by the speed of light c [m/s], the distance D12 [m] between the two reference devices 20(1) and 20(2) can be found.

The NW communication unit 410 of the management device 40 receives positioning related information regarding the positioning of the newly installed reference device 20' from the existing reference device 20 when the reference device 20' is additionally installed. The positioning related information from the reference device 20 includes, for example, the reference device identification information (Anchor ID) of the existing reference device (own device) 20, and the reference device identification information (Anchor ID) that can identify the reference device 20' to be added. , the transmission time information (Timestamp) of the positioning signal transmitted from the existing reference device (own device) 20 to the additionally installed reference device 20' and the positioning signal from the additionally installed reference device 20' to the existing reference device (own device) ) 20 includes reception time information (Timestamp). The positioning related information from the existing reference device 20 includes measurement information on the height (Z-axis coordinate) of the reference device (own device) 20 and measurement information on the height (Z-axis coordinate) of the additionally installed reference device 20. It may further contain.

FIG. 5 is a flowchart illustrating an example of the procedure (S100) for setting a coordinate system and determining the position coordinates of the reference devices 20 when installing a plurality of reference devices 20 in the positioning system of this embodiment. 6 to 10 are perspective views or plan views showing an example of the procedure for setting the coordinate system and determining the position coordinates of the reference device 20 in FIG. 5. 5 to 10 show examples in which the position coordinates of four reference devices 20 are determined and automatically registered, but when installing five or more reference devices 20, the same procedure is used for each reference device. The location coordinates of the device 20 can be determined and automatically registered.

In the following description, the first to fourth reference devices 20(1), 20(2), 20(3), and 20(4) are referred to as anchors A, B, C, and D, respectively. Further, vertical lines Lva, Lvb, Lvc, and Lvd in the figure are virtual vertical lines passing through the installation positions Pa, Pb, Pc, and Pd of anchors A, B, C, and D, respectively. Further, circles Rab, Rac, and Rad indicated by broken lines in the figure each indicate a virtual spherical surface whose radius is the distance from anchor A to other anchors B, C, and D. Similarly, circles Rba, Rbc, and Rbd each indicate a virtual spherical surface whose radius is the distance from anchor B to other anchors A, C, and D, and circles Rca, Rcb, and Rcd each indicate anchor C as the center. A virtual spherical surface whose radius is the distance to other anchors A, B, and D is shown.

In FIG. 5, the operator first installs the first anchor A in the positioning target space 10, and sets the height Ha of the anchor A from the floor, which is the horizontal bottom surface (in the example of FIG. 6, 203 [cm]) is measured (S101). The information on the measured height Ha of the anchor A may be transmitted to the management device 40 from the UE by the operator operating the UE (user equipment), which is his own terminal device, along with the request for initial positioning settings, or An operator may input the information to anchor A and transmit it from anchor A to the management device 40.

The management device 40 sets the origin (0, 0, 0) of the orthogonal coordinate system (X, Y, Z) used for positioning the target device 30 (S101). In the example of FIG. 6, the origin of the coordinate system (0, , 0, 0) are set. That is, the origin (0, 0, 0) of the coordinate system is the intersection of the horizontal bottom surface (floor surface) of the positioning target space 10 and the virtual vertical line Lva passing through the installation position Pa of the anchor A. The virtual vertical line Lva passing through is the upward positive Z axis (vertical coordinate axis).

Note that the origin (0, 0, 0) of the coordinate system may be the installation position Pa of the first anchor A.

Next, in FIG. 5, the worker installs the second anchor B in the positioning target space 10, and sets the height of the anchor B from the floor to a height Hb (205 [cm] in the example of FIG. 6). is measured (S102). Information on the measured height Hb of anchor B may be transmitted from the UE to the management device 40 by the worker operating the UE, or may be input by the worker into the anchor B and transmitted from the anchor B to the management device 40. You may.

The management device 40 is configured such that the installation position Pb where the second anchor B is installed is one of the two horizontal coordinate axes of the orthogonal coordinate system, the X-axis and the Y-axis (the X-axis in the example of FIG. 6). Two horizontal coordinate axes (X-axis and Y-axis) are set so as to be located on a virtual vertical plane (XZ plane) including the and Z-axis (vertical coordinate axes) (S102). In the example of FIG. 6, the horizontal axis passing through the installation position Pb of the second anchor B is the X-axis, and the direction from the installation position Pa (origin) of anchor A to the installation position Pb of anchor B is the positive side of the X-axis. It is the direction.

In the example of FIG. 6, when the horizontal axes (X-axis and Y-axis) of the coordinate system are set, the position coordinates of the installation position Pb of the second anchor B are (Xb, 0, 205), The coordinate Xb of anchor B on the X axis is unknown. In order to calculate and determine the coordinates Xb of anchor B, distance measurement is performed between anchor A and anchor B using the ToF method described above, and the distance between anchor A and anchor B, which is the result of the distance measurement, is Information on the distance measurement result is transmitted from anchor A to management device 40 (S102).

The management device 40 calculates and determines the coordinate Xb of the anchor B on the X axis based on the information of the measurement result of the distance between the anchor A and the anchor B received from the anchor A, and determines the height of the coordinate Xb. Based on the information on XHb, the position coordinates (Xb, 0, 205) of the installation position Pb of anchor B in the coordinate system are determined (S102).

Next, in FIG. 5, the worker installs the third anchor C in the positioning target space 10, and sets the height Hc of the anchor C from the floor surface (210 cm in the examples of FIGS. 7 and 8). ]) is measured (S103). Information on the measured height Hc of the anchor C may be transmitted from the UE to the management device 40 by a worker operating the UE, or may be input by the worker into the anchor C and transmitted from the anchor C to the management device 40. You may.

In the examples shown in FIGS. 7 and 8, when the height Hc of the anchor C is measured, the position coordinates of the installation position Pc of the anchor C are (Xc, Yc, 210), and the coordinates Xb of the anchor C on the X axis are The coordinate Yc on the Y axis is unknown. In order to calculate and determine the coordinates Xc, Yc of anchor C, distance measurement is performed between anchor A, anchor B, and anchor C using the ToF method described above, and each anchor that is the result of the distance measurement is Information on the measurement result of the distance between them is transmitted from the anchors A and B to the management device 40 (S103).

The management device 40 receives information on the measurement result of the distance between anchor A and anchor C received from anchor A, information on the measurement result of the distance between anchor B and anchor C received from anchor B, and the information on the measurement result of the distance between anchor B and anchor C received from anchor B. Based on the information on the height Hb of C, the position coordinates (Xc, Yc, 210) of the installation position Pc of the anchor C in the coordinate system are calculated and determined (S103).

Next, in FIG. 5, the worker installs the fourth anchor D in the positioning target space 10, and sets the height Hd of the anchor D from the floor (225 cm in the examples of FIGS. 9 and 10). ]) is measured (S104). Information on the measured height Hd of the anchor D may be transmitted from the UE to the management device 40 by a worker operating the UE, or may be input by the worker into the anchor D and transmitted from the anchor D to the management device 40. You may.

In the examples shown in FIGS. 9 and 10, at the stage when the height Hd of the anchor D is measured, the position coordinates of the installation position Pd of the anchor D are (Xd, Yd, 225), and the coordinates Xd of the anchor D on the X axis are The coordinate Yd on the Y axis is unknown. In order to calculate and determine the coordinates Xd, Yd of anchor D, distance measurement is performed between anchors A, B, and C and anchor D using the ToF method described above, and each anchor that is the result of the distance measurement is Information on the measurement results of the distances between the anchors A, B, and C is transmitted to the management device 40 (S104).

The management device 40 receives information on the measurement result of the distance between anchor A and anchor D received from anchor A, information on the measurement result of the distance between anchor B and anchor D received from anchor B, and Based on the information on the measurement result of the distance between anchor C and anchor D received from C and the information on the height Hd of anchor D, the position coordinates (Xd, Yd, 225) is calculated and determined (S104).

Note that when installing the fifth and subsequent anchors (E,...) in the positioning target space, similarly to step S104 in FIG. 5 and FIGS. 9 and 10, the fifth and subsequent anchors in the coordinate system are The position coordinates of the anchor installation position can be determined.

The management device 40 stores and registers the position coordinates of each anchor determined in the above procedure in the storage unit (DB) 430, as shown in Table 1 below, for example.

FIG. 11 is a flowchart showing another example of the procedure (S200) for setting the coordinate system and determining the position coordinates of the reference device when installing the reference device 20 of the positioning system of this embodiment. FIG. 12 is a perspective view showing an example of determining the position coordinates of the fourth reference device in FIG. 11. FIGS. 11 and 12 are examples in which measurement of the height of the fourth reference device 20 (anchor D) is unnecessary due to distance measurement using the TDoA method between reference stations. Note that S201 to S203 in FIG. 11 are the same as S101 to S103 in FIG. 5 described above, so the explanation will be omitted.

In FIG. 11, when the worker installs the fourth anchor D in the positioning target space 10, the position coordinates of the installation position Pd of the anchor D are (Xd, Yd, Zd), and each of the anchors D The coordinates Xd, Yd, and Zd on the axis are unknown. In order to calculate and determine the coordinates Xd, Yd, and Zd of anchor D, distance measurement is performed between anchors A, B, and C and anchor D using the TDoA method described above (S204).

As shown in FIG. 12, the transmitter of the positioning signal in distance measurement using the TDoA method is anchor D, and the receivers of the positioning signal are anchors A, B, and C. Anchor D transmits (emits) a positioning signal in a predetermined transmission format using UWB radio waves, as in the case of positioning the target device 30 described above. Anchors A, B, and C each receive a positioning signal transmitted (originated) from anchor D using UWB radio waves, and receive a predetermined signal including information included in the received positioning signal and reception time information (Timestamp) of the positioning signal. The positioning related information in the transmission format is transmitted to the management device 40. The management device 40 calculates and determines the coordinates Xd, Yd, and Zd of the anchor D based on the positioning-related information received from the anchors A, B, and C (S204).

Note that when installing the fifth and subsequent anchors (E,...) in the positioning target space, similarly to step S204 in FIG. 11 and FIG. The position coordinates of the installation position may be determined.

As described above, according to the present embodiment, when installing a plurality of reference devices 20 in the positioning target space 10, the position coordinates of each reference device 20 can be managed by simply measuring and setting only the height of each reference device 20. It is automatically registered in the device 40. Therefore, when installing a plurality of reference devices 20, the positional relationship between the installation positions of each reference device 20 (for example, the distance between the reference devices) is actually measured and registered. It becomes possible to simplify the man-hours.

Note that the processing steps and components of the positioning system (eg, reference device, target device, management device) described herein can be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

Regarding hardware implementation, processing used to realize the above steps and components in an entity (e.g., various wireless communication devices, communication modules, Node B, Node G, terminal, hard disk drive device, or optical disk drive device) The unit or the like may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processors (DSPDs), programmable logic devices (PLDs), field programmable gates, etc. implemented in an array (FPGA), processor, controller, microcontroller, microprocessor, electronic device, other electronic unit designed to perform the functions described herein, computer, or combinations thereof; may be done.

Additionally, for firmware and/or software implementations, the means used to implement the components described above, such as processing units, may include programs (e.g., procedures, functions, modules, instructions) that perform the functions described herein. , etc.). In general, any computer/processor readable medium tangibly embodying firmware and/or software code, such as a processing unit, may be used to implement the above steps and components described herein. It may be used for implementation. For example, the firmware and/or software code may be stored in memory and executed by a computer or processor, eg, in a controller. The memory may be implemented within the computer or processor, or external to the processor. The firmware and/or software code may also be stored in, for example, random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable PROM (EEPROM), etc. ), flash memory, floppy disks, compact disks (CDs), digital versatile disks (DVDs), magnetic or optical data storage devices, etc. good. The code may be executed by one or more computers or processors and may cause the computers or processors to perform certain aspects of the functionality described herein.

Further, the medium may be a non-temporary recording medium. Further, the code of the program may be read and executed by a computer, processor, or other device or apparatus, and its format is not limited to a specific format. For example, the code of the program may be a source code, an object code, or a binary code, or may be a mixture of two or more of these codes.

The description of the embodiments disclosed herein is also provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

10: Positioning possible space (positioning target space)
20: Reference device 30: Target device (device targeted for positioning)
40: Management device 45: Communication network 210: UWB communication unit 211: Antenna 230: Storage unit 240: NW communication unit 310: UWB communication unit 311: Antenna 330: Storage unit 410: NW communication unit 420: Positioning calculation unit 430: Memory Department

Claims (12)

The apparatus comprises a positioning target device and a plurality of reference devices installed at mutually different known position coordinates, and transmitting and receiving positioning signals via a wireless medium between the positioning target device and the plurality of reference devices. A positioning system that calculates and positions the position coordinates of the positioning target device using an algorithm based on the results of transmission and reception,
a coordinate origin setting unit that sets the origin of the orthogonal coordinate system so that the installation position where the first reference device is installed is located on the vertical coordinate axis of the orthogonal coordinate system used for positioning;
The two horizontal coordinates are arranged such that the installation position where the second reference device is installed is located on a virtual vertical plane that includes one of the two horizontal coordinate axes of the orthogonal coordinate system and the vertical coordinate axis. a horizontal coordinate axis setting section for setting the coordinate axes;
The distance between the first reference device and the second reference device is determined by transmitting and receiving positioning signals using the wireless medium between the first reference device and the second reference device. and determining the coordinates of the installation position of the second reference device on the one horizontal coordinate axis based on the distance measurement result and the height measurement result of the second reference device. a coordinate determining section;
By transmitting and receiving positioning signals using the wireless medium between the third and subsequent reference devices and each of the other reference devices including the first reference device and the second reference device, the third and subsequent reference devices measuring a plurality of distances between the reference device and each of the other reference devices, and based on the measurement results of the plurality of distances and the measurement results of the heights of the third and subsequent reference devices, the a second coordinate determination unit that determines the coordinates of the installation positions of the third and subsequent reference devices in the two horizontal coordinate axes of the orthogonal coordinate system;
A positioning system comprising: The positioning system according to claim 1,
A positioning system characterized in that an origin of the orthogonal coordinate system is an installation position of the first reference device. The positioning system according to claim 1,
The positioning system is characterized in that the origin of the orthogonal coordinate system is the intersection of the horizontal bottom surface of the positioning target space in which the plurality of reference devices are installed and the vertical coordinate axis. The positioning system according to any one of claims 1 to 3,
A positioning system characterized in that the wireless medium is UWB (ultra wideband) radio waves. The positioning system according to any one of claims 1 to 4,
A method for measuring the distance between the first reference device and the second reference device and the distance between the third and subsequent reference devices and the other reference device by transmitting and receiving the positioning signal is , a positioning system characterized by being a ToF (Time of Flight) method. The positioning system according to any one of claims 1 to 4,
The plurality of reference devices have mutual time synchronization or time difference managed,
A method for measuring a plurality of distances between each of the first reference device, the second reference device, and the third reference device by transmitting and receiving the positioning signal is a ToF (Time of Flight) method. and
A positioning system characterized in that a method for measuring a plurality of distances between the fourth and subsequent reference devices and the other reference devices is a TDoA (Time Difference of Arrival) method. The positioning system according to any one of claims 1 to 6,
The plurality of reference devices are four or more reference devices whose mutual time synchronization or time difference is managed,
The position coordinates of the positioning target device are determined by information on a plurality of time differences when the positioning signal transmitted from the positioning target device was received by each of the plurality of reference devices, and the position of each of the plurality of reference devices. A positioning system characterized in that the positioning system is calculated based on coordinate information. The positioning system according to any one of claims 1 to 7,
A positioning system characterized in that the device to be positioned is a wireless IC tag. The positioning system according to any one of claims 1 to 8,
comprising a management device capable of communicating with each of the plurality of reference devices via a communication network,
The management device includes the coordinate origin setting section, the horizontal coordinate axis setting section, the first coordinate determining section, the second coordinate determining section, and the coordinates of the installation positions of the plurality of reference devices in the orthogonal coordinate system. A positioning system comprising: a storage unit that stores information of the above. A management device capable of communicating with each of the plurality of reference devices in the positioning system according to any one of claims 1 to 8 via a communication network,
storing information on coordinates of the coordinate origin setting section, the horizontal coordinate axis setting section, the first coordinate determining section, the second coordinate determining section, and the installation positions of the plurality of reference devices in the orthogonal coordinate system; A management device comprising: a storage section; Positioning signals are transmitted and received via a wireless medium between the positioning target device and a plurality of reference devices installed at mutually different known position coordinates, and an algorithm based on the results of the transmission and reception is used to calculate the position of the positioning target device. A positioning method that calculates coordinates and measures the position,
setting the origin of the orthogonal coordinate system so that the installation position where the first reference device is installed is located on the vertical coordinate axis of the orthogonal coordinate system used for positioning;
The two horizontal coordinates are arranged such that the installation position where the second reference device is installed is located on a virtual vertical plane that includes one of the two horizontal coordinate axes of the orthogonal coordinate system and the vertical coordinate axis. Setting the coordinate axes and
The distance between the first reference device and the second reference device is determined by transmitting and receiving positioning signals using the wireless medium between the first reference device and the second reference device. and determining the coordinates of the installation position of the second reference device on the one horizontal coordinate axis based on the distance measurement result and the height measurement result of the second reference device. ,
By transmitting and receiving positioning signals using the wireless medium between the third and subsequent reference devices and each of the other reference devices including the first reference device and the second reference device, the third and subsequent reference devices measuring a plurality of distances between the reference device and each of the other reference devices, and based on the measurement results of the plurality of distances and the measurement results of the heights of the third and subsequent reference devices, the determining the coordinates of the installation positions of the third and subsequent reference devices in the two horizontal coordinate axes of the orthogonal coordinate system;
A positioning method characterized by comprising: A program executed on a computer or processor included in the management device according to claim 9 or 10,
program code for communicating with each of the plurality of reference devices via a communication network;
A program code for setting the origin of the orthogonal coordinate system so that the installation position where the first reference device is installed is located on the vertical coordinate axis of the orthogonal coordinate system used for positioning;
The two horizontal coordinates are arranged such that the installation position where the second reference device is installed is located on a virtual vertical plane that includes one of the two horizontal coordinate axes of the orthogonal coordinate system and the vertical coordinate axis. Program code for setting the coordinate axes,
The distance between the first reference device and the second reference device is determined by transmitting and receiving positioning signals using the wireless medium between the first reference device and the second reference device. and determining the coordinates of the installation position of the second reference device on the one horizontal coordinate axis based on the distance measurement result and the height measurement result of the second reference device. program code and
By transmitting and receiving positioning signals using the wireless medium between the third and subsequent reference devices and each of the other reference devices including the first reference device and the second reference device, the third and subsequent reference devices measuring a plurality of distances between the reference device and each of the other reference devices, and based on the measurement results of the plurality of distances and the measurement results of the heights of the third and subsequent reference devices, the a program code for determining the coordinates of the installation position of the third and subsequent reference devices in the two horizontal coordinate axes of the orthogonal coordinate system;
a program code for storing information on position coordinates of each of the plurality of reference devices;
A program characterized by including.

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