JP7361087B2 - Positioning system, installation auxiliary device, management device, positioning method and program - Google Patents

Description

The present invention relates to a positioning system, an installation auxiliary device, 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. There are known positioning systems that transmit and receive wireless media such as radio waves, sound waves, and light in a line-of-sight environment (LOS environment) between , 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 transmits and receives positioning signals using a wireless medium, receives the results of the transmission and reception as input, and outputs the position coordinates of the device to be positioned. In this positioning system, a reference point is set as a reference point for the position coordinates of the plurality of reference devices in a predetermined coordinate system, and a plurality of auxiliary points at four or more locations whose relative positional relationships with the reference point are known are set. an installation auxiliary device, the installation auxiliary device being provided with a plurality of auxiliary communication devices that are set at each of the plurality of auxiliary points and capable of transmitting and receiving positioning signals via the wireless medium to and from the plurality of reference devices; and the installation auxiliary device is installed. For each of the plurality of reference devices in the positioning target space where and a coordinate determining unit that measures a distance between the reference devices and determines the coordinates of the reference device in the coordinate system based on the measurement result of the distance.

A device according to another aspect of the present invention is an installation auxiliary device that assists in installing the plurality of reference devices in the positioning system. This installation auxiliary device has a reference point that serves as a reference for the position coordinates of the plurality of reference devices in a predetermined coordinate system, and a plurality of auxiliary points at four or more locations whose relative positional relationship with the reference point is known. are set, and a plurality of auxiliary communication devices capable of transmitting and receiving positioning signals via the wireless medium to and from the plurality of reference devices are provided at the plurality of auxiliary points.

A device according to still another aspect of the present invention is a management device capable of communicating with each of the plurality of reference devices in the positioning system via a communication network. This management device includes the coordinate determination section and a storage section that stores information on the coordinates of the installation positions of the plurality of reference devices in the coordinate system.

A method according to still another aspect of the present invention transmits and receives positioning signals using a wireless medium between a device to be positioned and a plurality of reference devices installed at mutually different known position coordinates, and transmits and receives the results of the transmission and reception. This is a positioning method that outputs the position coordinates of the positioning target device as input. In this positioning method, a reference point that serves as a reference for the position coordinates of the plurality of reference devices in a predetermined coordinate system is set, and a plurality of auxiliary points at four or more locations whose relative positional relationships with the reference point are known are set. and installing an installation auxiliary device in a positioning target space, the installation auxiliary device being provided with a plurality of auxiliary communication devices that are set and capable of transmitting and receiving positioning signals via the wireless medium to the plurality of reference devices at the plurality of auxiliary points. , for each of the plurality of reference devices in the positioning target space where the installation auxiliary device is installed, by transmitting and receiving positioning signals by the wireless medium between the reference device and the plurality of auxiliary communication devices, The method includes measuring distances between the plurality of auxiliary communication devices, and determining coordinates of the reference device in the coordinate system based on the distance measurement 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 a program code for communicating with each of the plurality of reference devices in the positioning target space in which the installation auxiliary device is installed. The distance between the reference device and the plurality of auxiliary communication devices is measured by transmitting and receiving a positioning signal to and from the plurality of auxiliary communication devices via the wireless medium, and the coordinates are determined based on the distance measurement results. and program code for determining coordinates of the reference device in a system.

In the positioning system, the management device, the positioning method, and the program, the main body of the installation auxiliary device is a frame structure, and the reference point and the plurality of auxiliary points are each located at a corner of the frame structure. may be located. Further, the main body of the installation auxiliary device is a frame structure in which four or more of the reference devices or the positioning target device can be installed, which collectively refers to a columnar three-dimensional figure structure such as a rectangular parallelepiped with a polygonal bottom surface. It's okay.

In the positioning system, the management device, the positioning method, and the program, the reference point and any one of the plurality of auxiliary points may be the same point.

In the positioning system, the management device, the positioning method, and the program, the origin of the coordinate system may be an installation position of any one of the plurality of reference devices.

In the positioning system, the management device, the positioning method, and the program, the origin of the coordinate system is the horizontal bottom of the positioning target space in which the plurality of reference devices are installed, and any one of the plurality of reference devices. It may also be an intersection with a vertical coordinate axis passing through the installation position of one of the reference devices.

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, a method for measuring the distance between the reference device and the plurality of auxiliary communication devices by transmitting and receiving the positioning signal is a ToF (Time of Flight) method. There may be.

In the positioning system, the management device, the positioning method, and the program, the reference device and the plurality of auxiliary communication devices have mutual time synchronization or time difference managed, and the reference device and the The distance measurement method between the plurality of auxiliary communication devices 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 includes a management device capable of communicating with each of the plurality of reference devices via a communication network, and the management device is configured to control the coordinate determination unit and the installation position of the plurality of reference devices in the coordinate system. The storage unit may also include a storage unit that stores coordinate information.

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, an auxiliary communication device of an installation auxiliary device, and a management device when the reference device of the positioning system of FIG. 1 is installed. 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 auxiliary communication device of the installation auxiliary device and the reference device. FIG. 3 is a perspective view showing an example of an installation auxiliary device that assists in the installation work of the reference device. FIG. 2 is an explanatory diagram showing an example of wireless communication between a reference device and an auxiliary communication device of an installation auxiliary device when a plurality of reference devices are installed in the positioning system of the embodiment. 7 is a flowchart illustrating an example of a procedure for determining the position coordinates of a reference device when a plurality of reference devices are installed in the positioning system of the embodiment.

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 positioning system that transmits and receives positioning signals using ultra-wideband (UWB) radio waves, receives the results of the transmission and reception as input, and outputs the position coordinates of a tag (device to be positioned). For example, the positioning system of this embodiment calculates and outputs the position coordinates of the tag using an algorithm of the TDoA (Time Difference of Arrival) method or the ToA (Time of Arrival) ranging estimation method based on the transmission and reception of the positioning signal. .

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 can simplify the man-hours for installing multiple anchors used for positioning by using an anchor installation stand (installation auxiliary device) that has multiple auxiliary anchors (auxiliary reference devices). It is a positioning system.

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 of the reference devices 20A(1) to 20A(4), 20B(1) to 20B(4), reference devices 20 or 20(1), 20(2), It is written as... Further, when describing each target device 30A, 30B, it will be referred to 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. In addition, for a more detailed explanation of setting the coordinate system and determining the position coordinates of the reference devices when installing a plurality of reference devices 20 using an anchor installation stand (installation auxiliary device) having a plurality of auxiliary anchors (auxiliary 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.

The mutual time synchronization or time difference between the plurality of reference devices 20 is managed by any synchronization method that is applicable between the devices. Each of the plurality of reference devices 20 includes an internal clock whose time synchronization or time difference between the reference devices 20 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 at an arbitrary point within the positioning target space 10. For example, the position coordinates of the plurality of reference devices 20 may be relative position coordinates in an orthogonal coordinate system in which the origin is set at an arbitrary point on the vertical coordinate axis passing through the installation position of any one of the reference devices 20. good.

The position coordinates of the plurality of reference devices 20 in a predetermined coordinate system of the positioning target space 10 are determined by the position coordinates between the reference device 20 and the plurality of auxiliary anchors (auxiliary reference devices) of the anchor installation base (installation auxiliary device) as described later. This can be determined by transmitting and receiving positioning signals.

If the position coordinates of a plurality of reference devices 20 cannot be determined by transmitting and receiving positioning signals between an auxiliary anchor (auxiliary reference device) and the reference devices 20, which will be described later, general surveying techniques (e.g., total station, laser ranging It may also be determined by surveying using sensors. 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 . In this case, the position coordinates 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. Alternatively, it may be a conversion coordinate system to ENU (East (m), North (m), Upper Up (m): relative distance from the reference point) coordinates with a certain reference point as the origin.

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 defined by 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 shows the reference device (anchor) 20, the auxiliary communication device (auxiliary anchor) 500 of the installation auxiliary device (anchor installation stand) 50, and the management device 40 when the reference device (anchor) 20 of the positioning system of FIG. 1 is installed. FIG. 2 is a block diagram showing an example of the main configuration. Note that in FIG. 3, the reference device 20 is a reference device to be installed. 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 unit 510 of the auxiliary communication device 500 also functions as a positioning signal transmitting/receiving unit when the reference device 20 is installed. Further, the UWB communication unit 510 of the auxiliary communication device 500 transmits a positioning signal using UWB radio waves to the reference device 20 via the antenna 511 when the reference device 20 is installed. Further, the UWB communication unit 510 receives, via the antenna 511, a positioning signal returned from the reference device 20 to be installed. In addition, the UWB communication unit 510 of the auxiliary communication device 500 transmits transmission time information (Timestamp) at which the positioning signal was transmitted to the reference device 20 to be installed, and reception time information (Timestamp) 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 auxiliary communication device 500 includes, for example, frame control information (Frame Control), a transmission sequence number (Sequence Number), and group identification information (PAN) of a PAN (Personal Area Network) for short-range wireless communication. ID), address (Destination Address) (1 to n) of the communication destination (reference device 20) in the PAN, address (Source Address) (1 to n) of the communication source (auxiliary communication device 500) in the PAN, message identification information ( Message ID).

The storage unit 530 of the auxiliary communication device 500 stores various information included in the positioning signal output from the UWB communication unit 510, 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. Timestamp) are stored in association with each other.

The NW communication unit 540 of the auxiliary communication device 500 transmits positioning-related information regarding the positioning of the reference device 20 to be installed, which is stored in the storage unit 530, to the management device 40. The transmission format of the positioning-related information sent to the management device 40 includes, for example, reference device identification information (Anchor ID) that can identify the auxiliary communication device (own device) 500, and reference device identification information that can identify the reference device 20 to be installed. It includes identification information (Anchor ID), transmission time information (Timestamp) of the positioning signal to the reference device 20 to be installed, and reception time information (Timestamp) of the positioning signal from the reference device 20 to be installed.

In FIG. 3, the UWB communication unit 210 of the reference device 20 to be installed also functions as a positioning signal transmitting/receiving unit when the reference device (own device) 20 is installed. Further, the UWB communication unit 210 of the reference device 20 receives a positioning signal using UWB radio waves from the auxiliary communication device 500 via the antenna 211 when the reference device (own device) 20 is installed. is sent back to the auxiliary communication device 500.

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 also functions as a coordinate determination unit that determines the coordinates of the reference device 20 in a coordinate system (for example, an orthogonal coordinate system) used for positioning when the reference device 20 is installed. The positioning calculation unit 420 serving as a coordinate determination unit performs communication between the reference device 20 and the plurality of auxiliary communication devices 500 via a wireless medium for each of the plurality of reference devices 20 in the positioning target space 10 in which the installation auxiliary device 50 is installed. The distance between the reference device 20 and the plurality of auxiliary communication devices 500 is measured by transmitting and receiving positioning signals, and the coordinates of the reference device 20 in the coordinate system are determined based on the distance measurement results.

FIG. 4 is an explanatory diagram showing an example of a ToF distance measuring technique that can be used to measure the distance between the auxiliary communication device 500 of the installation auxiliary device 50 and the reference device 20. FIG. 4 is an example of measuring the distance D [m] between the auxiliary communication device 500 and the reference device 20 in a line-of-sight environment (LOS environment). In FIG. 4, Tloop[s] is the time from when the auxiliary communication device 500 as an initiator transmits (originates) a positioning signal using UWB radio waves until it receives a response signal to the positioning signal from the reference device 20 as a responder. , Let Treply [s] be the time from when the reference device 20 receives the positioning signal to when it transmits the response signal, the distance between the auxiliary communication device 500 and the reference device 20 is set in one direction. The propagation time ToF [s] is expressed by the following equation (7).

By multiplying the propagation time ToF [s] by the speed of light c [m/s], the distance D [m] between the auxiliary communication device 500 and the reference device 20 is found.

The NW communication unit 410 of the management device 40 receives positioning-related information regarding the positioning of the reference device 20 to be installed from the auxiliary communication device 500 when the reference device 20 is installed. The positioning related information from the auxiliary communication device 500 includes, for example, reference device identification information (Anchor ID) of the auxiliary communication device 500, reference device identification information (Anchor ID) that can identify the reference device 20 to be installed, and the auxiliary communication device 500. The transmission time information (Timestamp) of the positioning signal transmitted from the reference device 20 to the reference device 20 and the reception time information (Timestamp) at which the auxiliary communication device 500 received the positioning signal from the reference device 20 are included.

FIG. 5 is a perspective view showing an example of an installation assistance device 50 that assists in the installation work of the reference device 20. In FIG. 5, an installation auxiliary device (anchor installation stand) 50 has a reference point P0 that serves as a reference for the positional coordinates of a plurality of reference devices 20 in a predetermined coordinate system, and a relative positional relationship with the reference point P0. A plurality of auxiliary points of four or more locations (four auxiliary points in the illustrated example) with known values are set. A plurality of auxiliary communication devices 500(1) to 500(4) capable of transmitting and receiving positioning signals using a wireless medium (for example, UWB radio waves) to and from a plurality of reference devices 20 at a plurality of auxiliary points of the installation auxiliary device 50. is provided.

The main body 51 of the installation auxiliary device 50 is a rectangular parallelepiped frame structure, and the reference point P0 and the plurality of auxiliary points are each located at a corner of the main body 51 made of the frame structure. The frame structure of the installation auxiliary device 50 may be a foldable structure that can take a folded state during transportation and storage and an expanded state during use. Further, the frame structure may be a structure that can be disassembled and assembled, which can be in a disassembled state during transportation and storage and an assembled state during use. Moreover, the frame structure may be in the above-mentioned expanded state or the above-mentioned assembled structure state during transportation and storage.

The main body 51 of the installation auxiliary device 50 is a frame structure in which four or more auxiliary communication devices or target devices (positioning target devices) can be installed, which collectively refers to a columnar three-dimensional figure structure such as a rectangular parallelepiped with a polygonal bottom surface. It may be. In addition to such three-dimensional shapes, shapes such as T-shapes, Y-shapes, H-shapes, and O-shapes, such as combinations of rectangular parallelepipeds like a jungle gym, in other words, extending in three directions with one point as the center. The basic structure may be a linear figure (T-shape or Y-shape), and it may include a figure that is a combination of any number of these basic structures.

In the example of FIG. 5, the reference point P0 and the plurality of auxiliary points are set to different points, but the reference point P0 and any one of the plurality of auxiliary points may be the same point. Further, in the example of FIG. 5, the coordinate system is a rectangular coordinate system, and the origin of the orthogonal coordinate system is set at the reference point P0, but the coordinate system may be a coordinate system other than the orthogonal coordinate system, Further, the origin of the coordinate system may be set at any point in the positioning target space 10 other than the reference point P0. For example, the origin of the coordinate system may be the installation position of any one of the plurality of reference devices 20. Further, the origin of the coordinate system is the horizontal bottom surface (for example, an indoor floor surface) of the positioning target space 10 where the plurality of reference devices 20 are installed, and the installation position of any one of the plurality of reference devices 20. It may also be the intersection with the vertical coordinate axis passing through.

FIG. 6 is an explanatory diagram showing an example of wireless communication between the reference device 20 and the auxiliary communication device 500 of the installation auxiliary device 50 when the plurality of reference devices 20 are installed in the positioning system of this embodiment. FIG. 7 is a flowchart illustrating an example of the procedure (S100) for determining the position coordinates of a reference device when a plurality of reference devices are installed in the positioning system of this embodiment. Note that FIGS. 6 and 7 show an example in which the number of multiple reference devices 20 is n, and the number of multiple auxiliary communication devices 500 of the installation auxiliary device 50 is four. In addition, in the description of FIGS. 6 and 7, the reference device 20 is referred to as an "anchor," the installation assistance device 50 is referred to as an "anchor installation stand," and the auxiliary communication device 500 is referred to as an "auxiliary anchor."

In FIG. 7, the operator first determines where to set the reference point P0 in the positioning target space 10, and deploys it so that the reference point P0 of the anchor installation base 50 is located at the target point of the reference point P0. The anchor installation base 50 in a state or an assembled structure state is installed (S101).

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 as the reference point P0. That is, the origin (0, 0, 0) of the coordinate system is the reference point P0 of the anchor installation base 50, and the virtual vertical line passing through the origin is the upward positive Z axis (vertical coordinate axis). Furthermore, the direction from the reference point P0 to the auxiliary anchor 500(3) is the positive direction of the X-axis of the coordinate system, and the direction from the reference point P0 to the auxiliary anchor 500(4) is the positive direction of the Y-axis of the coordinate system. be.

Next, when the operator installs the first anchor 20(1), the position coordinates of the anchor 20(1) are determined by ToF ranging as follows (S102). In this ToF distance measurement, distance measurement is performed between the plurality of auxiliary anchors 500(1) to 500(4) and the anchor 20(1) using the ToF method described above, and the auxiliary anchor 500 is the result of the distance measurement. Information on the measurement results of the distances between each of auxiliary anchors 500(1) to 500(4) and anchor 20(1) is transmitted to management device 40 from each of auxiliary anchors 500(1) to 500(4). The management device 40 determines the positional coordinates of the installation position of the anchor 20(1) in the coordinate system based on the measurement result information received from each of the auxiliary anchors 500(1) to 500(4).

Next, when the worker installs the second anchor 20(2), the position coordinates of that anchor 20(2) are determined by ToF distance measurement as follows, similar to the first anchor 20(1). (S103). That is, distance measurement is performed between the plurality of auxiliary anchors 500(1) to 500(4) and the anchor 20(2) using the ToF method described above, and the auxiliary anchors 500(1) to 500(1) which are the results of the distance measurement are performed. Information on the measurement result of the distance between each of the auxiliary anchors 500(4) and the anchor 20(2) is transmitted to the management device 40 from each of the auxiliary anchors 500(1) to 500(4). The management device 40 determines the positional coordinates of the installation position of the anchor 20(2) in the coordinate system based on the measurement result information received from each of the auxiliary anchors 500(1) to 500(4).

The position coordinates of the third and subsequent anchors 20(3) to 20(n) installed by the worker are also ToF, similar to the first anchor 20(1) and the second anchor 20(2). It is determined by distance measurement (S104).

The management device 40 stores and registers the position coordinates of each anchor determined in the above procedure in the storage unit (DB) 430 described above.

In the example of FIG. 7, installation of the anchors and determination of the position coordinates of the anchors by ToF distance measurement are performed one by one from the first anchor 20(1) to the nth anchor 20(n). However, the installation of each anchor 20(1) to 20(n) and the determination of the position coordinates of each anchor 20(1) to 20(n) by ToF ranging may be performed in parallel in random order.

In the example of FIG. 7, information on the measurement results of the distance between each of the auxiliary anchors 500(1) to 500(4) and the anchor 20 by the ToA method is transmitted from each of the auxiliary anchors 500(1) to 500(4). Although the data is sent to the management device 40, time stamp data used for ToA distance measurement may be sent to the management device 40 from each of the auxiliary anchors 500(1) to 500(4). In this case, the management device 40 calculates the distance between the auxiliary anchors 500(1) to 500(4) and the anchor 20 using the time stamp data received from each of the auxiliary anchors 500(1) to 500(4). A distance measurement process is executed to determine the positional coordinates of the installation position of the anchor 20 in the coordinate system.

In addition, in the example of FIG. 7, for the second and subsequent n-th anchors 20(n) (n≧2), the auxiliary anchors 500(1) to 500(4) and the n-1 anchor whose coordinates have been determined are The position coordinates of the installation position may be determined using an anchor up to the eye. For example, the position coordinates of the installation position of the fourth anchor 20(4) are the auxiliary anchors 500(1) to 500(4) and the third anchors 20(1) to 20( whose coordinates have been determined). 3) may be used for determination.

In addition, in the example of FIG. 7, the position coordinates of the plurality of anchors 20(1) to 20(n) to be installed are determined by distance measurement using the ToF method. A part or all of the position coordinates of 20(n) may be determined by TDoA distance measurement. In this case, the time synchronization or time difference between the auxiliary anchors 500(1) to 500(4) and the installation target anchors 20(1) to 20(n) is managed.

In distance measurement using the TDoA method, the positioning signal transmitters are the installation target anchors 20(1) to 20(n), and the positioning signal receivers are the auxiliary anchors 500(1) to 500(4). . Each of the anchors 20(1) to 20(n) 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. Each of the auxiliary anchors 500(1) to 500(4) receives a positioning signal transmitted (originated) from the anchor 20 using UWB radio waves, and receives information contained in the received positioning signal and reception time information (Timestamp) of the positioning signal. ) is transmitted to the management device 40 in a predetermined transmission format. Management device 40 calculates and determines the position coordinates of anchor 20 based on the positioning related information received from auxiliary anchors 500(1) to 500(4).

Also, when using ranging using the TDoA method, the installation of each anchor 20(1) to 20(n) and the determination of the position coordinates of each anchor 20(1) to 20(n) by ToF ranging are performed in parallel in random order. You can go there.

Also, when using TDoA distance measurement, the time stamp data used for TDoA distance measurement is transmitted from each of the auxiliary anchors 500(1) to 500(4) to the management device 40, and the management device 40 A distance measurement process is executed to calculate the distance between the auxiliary anchors 500(1) to 500(4) and the anchor 20 using the time stamp data received from each of the auxiliary anchors 500(1) to 500(4). , the positional coordinates of the installation position of the anchor 20 in the above coordinate system may be determined.

Also, when using distance measurement using the TDoA method, for the second and subsequent n-th anchors 20 (n) (n≧2), the coordinates of the auxiliary anchors 500 (1) to 500 (4) and the n - The position coordinates of the installation position may be determined using up to the first anchor.

As described above, according to the present embodiment, when installing a plurality of reference devices 20 in the positioning target space 10, each reference device 20 is The position coordinates are automatically registered in the management 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.

It should be noted that the processing steps described herein as well as the components of the positioning system (eg, reference device, target device, management device, auxiliary communication device) 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 50: Installation auxiliary device (anchor installation stand)
51: Body frame 210: UWB communication section 211: Antenna 230: Storage section 240: NW communication section 310: UWB communication section 311: Antenna 330: Storage section 410: NW communication section 420: Positioning calculation section 430: Storage section 500: Auxiliary Reference device (auxiliary anchor)
510: UWB communication section 511: Antenna 530: Storage section 540: NW communication section

Claims (15)

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 receives the results of transmission and reception as input and outputs the position coordinates of the device to be positioned,
A reference point serving as a reference for the position coordinates of the plurality of reference devices in a predetermined coordinate system is set, a plurality of auxiliary points at four or more locations whose relative positional relationships with the reference point are known are set, and the plurality of an installation auxiliary device including a plurality of auxiliary communication devices capable of transmitting and receiving positioning signals via the wireless medium to and from the plurality of reference devices at auxiliary points;
For each of the plurality of reference devices in the positioning target space in which the installation auxiliary device is installed, the reference device and the a coordinate determining unit that measures distances between a plurality of auxiliary communication devices and determines the coordinates of the reference device in the coordinate system based on the distance measurement results;
A positioning system comprising: The positioning system according to claim 1,
The main body of the installation auxiliary device is a frame structure,
The positioning system, wherein the reference point and the plurality of auxiliary points are each located at a corner of the frame structure. The positioning system according to claim 1 or 2,
A positioning system characterized in that the reference point and any one of the plurality of auxiliary points are the same point. The positioning system according to any one of claims 1 to 3,
A positioning system characterized in that the origin of the coordinate system is an installation position of any one of the plurality of reference devices. The positioning system according to any one of claims 1 to 3,
The origin of the coordinate system is the intersection of a horizontal bottom surface of the positioning target space in which the plurality of reference devices are installed and a vertical coordinate axis passing through the installation position of any one of the plurality of reference devices. A positioning system characterized by: The positioning system according to any one of claims 1 to 5,
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 6,
A positioning system characterized in that a method for measuring the distance between the reference device and the plurality of auxiliary communication devices by transmitting and receiving the positioning signal is a ToF (Time of Flight) method. The positioning system according to any one of claims 1 to 6,
The reference device and the plurality of auxiliary communication devices have mutual time synchronization or time difference managed,
A positioning system characterized in that a method for measuring the distance between the reference device and the plurality of auxiliary communication devices by transmitting and receiving the positioning signal is a TDoA (Time Difference of Arrival) method. The positioning system according to any one of claims 1 to 8,
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 9,
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 10,
comprising a management device capable of communicating with each of the plurality of reference devices and the plurality of auxiliary communication devices via a communication network,
A positioning system characterized in that the management device includes the coordinate determination section and a storage section that stores information on coordinates of installation positions of the plurality of reference devices in the coordinate system. An installation auxiliary device for assisting the installation work of the plurality of reference devices in the positioning system according to any one of claims 1 to 11,
A reference point serving as a reference for the position coordinates of the plurality of reference devices in a predetermined coordinate system is set, a plurality of auxiliary points at four or more locations whose relative positional relationships with the reference point are known are set, and the plurality of An installation auxiliary device characterized in that a plurality of auxiliary communication devices capable of transmitting and receiving positioning signals using the wireless medium are provided at auxiliary points of the plurality of reference devices. A management device capable of communicating with each of the plurality of reference devices and the plurality of auxiliary communication devices in the positioning system according to any one of claims 1 to 10 via a communication network,
A management device comprising: the coordinate determination unit; and a storage unit that stores information on coordinates of installation positions of the plurality of reference devices in the coordinate system. Transmitting and receiving positioning signals via a wireless medium between the positioning target device and a plurality of reference devices installed at mutually different known position coordinates, and outputting the position coordinates of the positioning target device using the results of the transmission and reception as input. A positioning method,
A reference point serving as a reference for the position coordinates of the plurality of reference devices in a predetermined coordinate system is set, a plurality of auxiliary points at four or more locations whose relative positional relationships with the reference point are known are set, and the plurality of installing in the positioning target space an installation auxiliary device including a plurality of auxiliary communication devices capable of transmitting and receiving positioning signals via the wireless medium to and from the plurality of reference devices at auxiliary points;
For each of the plurality of reference devices in the positioning target space in which the installation auxiliary device is installed, the reference device and the Measuring distances to a plurality of auxiliary communication devices, and determining coordinates of the reference device in the coordinate system based on the distance measurement results;
A positioning method characterized by comprising: A program executed on a computer or processor included in the management device according to claim 11 or 13,
program code for communicating with each of the plurality of reference devices via a communication network;
For each of the plurality of reference devices in the positioning target space in which the installation auxiliary device is installed, the reference device and the Program code for measuring distances between a plurality of auxiliary communication devices and determining coordinates of the reference device in the coordinate system based on the distance measurement results;
A program characterized by including.

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