POSITIONING SYSTEM, ACCESS CONTROL SYSTEM, AND POSITIONING METHOD

A positioning system includes: a transmitting and receiving part having multiple antennas and positioned overhead in a positioning target area with a side entrance; a distance calculation part configured to calculate a distance between a communication device that can move in the positioning target area, and the transmitting and receiving part, based on results gained from signals of multiple frequencies transmitted bidirectionally between the communication device and the transmitting and receiving part; an angle calculation part configured to calculate an angle that indicates a position of the communication device with respect to the transmitting and receiving part, based on a phase difference between the signals received by the antennas of the transmitting and receiving part; and a determining part configured to determine whether or not the communication device is approaching the side entrance based on the distance and angle calculated by the distance calculation part and the angle calculation part.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority to Japanese Patent Application No. 2022-203540, filed on Dec. 20, 2022, the entire contents s of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a positioning system, an access control system, and a positioning method.

2. Description of the Related Art

Heretofore, there is an information output system with: an information generation part that, when there are a first area and a second area neighboring the first area, generates first information related to the position of a mobile communication terminal in the first area, based on a radio signal received from the mobile communication terminal located in the first area; and an output part that outputs second information related to movement of the mobile communication terminal from the first area to the second area, based on the first information. The first information and the second information are information related to the received signal strength indication (RSSI) of radio signals (see, for example, Patent Document 1).

CITATION LIST

Patent Document

Patent Document 1: Unexamined Japanese Patent Application Publication No. 2018-179952

SUMMARY OF THE INVENTION

Technical Problem

The above conventional information output system (positioning system) determines in which one of the first area and the second area the mobile communication terminal (communication device) is located, based on the received signal strength indication (RSSI) of radio signals. The radio signals may arrive straight as direct-path signals without undergoing reflection, or the radio signals may undergo reflection off structures such as building walls and arrive as multi-path signals. Consequently, calculations based on received signal strength indications show significant errors due to multi-path signals, making it difficult to calculate the position of a communication device accurately.

It is therefore an object of the present disclosure to provide a positioning system, an access control system, and a positioning method whereby the position of a communication device can be calculated accurately.

Solution to Problem

According to an embodiment of the present disclosure, a positioning system includes: a transmitting and receiving part having a plurality of antennas and positioned overhead in a positioning target area where there is a side entrance; a distance calculation part configured to calculate a distance between a communication device that can move in the positioning target area, and the transmitting and receiving part, based on results gained from signals of a plurality of frequencies transmitted bidirectionally between the communication device and the transmitting and receiving part; an angle calculation part configured to calculate an angle that indicates a position of the communication device with respect to the transmitting and receiving part, based on a phase difference between the signals received by the plurality of antennas of the transmitting and receiving part; and a determining part configured to determine whether or not the communication device is approaching the side entrance based on the distance calculated by the distance calculation part and the angle calculated by the angle calculation part.

Advantageous Effects of the Invention

It is therefore possible to provide a positioning system, an access control system, and a positioning method whereby the position of a communication device can be calculated accurately.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, an embodiment using the positioning system, access control system, and positioning method according to the present disclosure will be described below.

Embodiment

FIG.1is a diagram that shows an example structure of a space in which an access control system100including a positioning system according to an embodiment is installed.

Walls10are provided with automatic gates11and12. The automatic gates11and12are examples of gates provided at side entrances. The side entrances where the automatic gates11and12are installed are the only side entrance for entering the space inside the walls10from the space outside the walls10, and the only side entrance for exiting from the space inside the walls10to the space outside the walls10. The walls10may be various walls, such as walls surrounding a room, walls separating the outside and the inside of a building, and so forth. Below, an example in which the walls10surround a room10R will be described.

The access control system100controls entry to/exit from the room10R by performing an authentication by using the identifier of a smartphone200that a user20carries with him/her, and controlling the automatic gates11and12to open and close. The user20is an example of a moving object that can move together with the smartphone200, and the smartphone200is an example of a communication device.

When a smartphone200approaching the automatic gate11or12is detected, the access control system100performs an authentication process, and, when the authentication is successfully completed, the access control system100opens the automatic gate11or12. The access control system100performs the authentication process every time a smartphone200approaches the automatic gate11or12.

The access control system100specifies the position of the smartphone200of the user20in the room10R based on the distance and angles of the smartphone200with respect to a reference point, which are determined in a distance calculation process and an angle calculation process, thereby detecting when the user20comes in front of the automatic gate11or12. The reference point is the center point of a transmitting and receiving part110of the access control system100. Note that, instead of performing an authentication process using the identifier of the user20's smartphone200, the access control system100may perform an authentication process using biological information of the user20(for example, face verification, fingerprint verification, etc.), or perform an authentication process using identification information that the user20carries with him/her (employee ID, student ID, etc.).

In this one example, the automatic gate11is closed and the automatic gate12is open. Closing the automatic gates11and12means closing and locking the automatic gates11and12. Also, opening the automatic gates11and12means unlocking and opening the automatic gates11and12. That is, when the access control system100controls the automatic gates11and12to open and close, the access control system100locks and unlocks the automatic gates11and12on a switching basis.

Note that, although an example will be described here in which the automatic gates11and12are provided in the room10R, it is also possible to provide a manual gate that the user20can touch and open/close with his/her hand, instead of at least one of the automatic gates11and12. In the event a manual gate is provided in the room10R thus, the access control system100has only to likewise lock and unlock the manual gate on a switching basis.

<Structure of Access Control System100>

The access control system100includes a transmitting and receiving part110and a control device120.

<Transmitting and Receiving Part110>

The transmitting and receiving part110is, for example, a device that is provided in the ceiling of the room10R, and that can communicate with the smartphone200in a communicable area covering substantially the entire area in the room10R including in front of the automatic gates11and12. Note that the transmitting and receiving part110needs only to have its communicable area at least in a three-dimensional area in front of the automatic gates11and12in the room10R. Therefore, the location to place the transmitting and receiving part110is not limited to the ceiling of the room10R, and, for example, the transmitting and receiving part110may be suspended from the ceiling. The transmitting and receiving part110is preferably positioned overhead in the room10R. “Overhead in the room10” refers to a position that is higher than the average person's height, and, for example, a position 2 meters or more above the ground/floor may be suitable.

The control device120is connected to the transmitting and receiving part110by a cable or the like, structured to be capable of data communication with the transmitting and receiving part110, and provided inside or outside the room10R. Note that the control device120may be structured to be capable of wireless data communication with the transmitting and receiving part110. In this case, the method of wireless communication between the control device120and the transmitting and receiving part110has only to be different from the method of wireless communication between the smartphone200and the transmitting and receiving part110.

The control device120performs data communication with the smartphone200via the transmitting and receiving part110and performs a TOA (Time of Arrival)-based distance calculation process and an AOA (Angle of Arrival)-based angle calculation process, thereby calculating, three-dimensionally, the position of the smartphone200with respect to the transmitting and receiving part110in the room10R.

The area in which the transmitting and receiving part110can communicate with the smartphone200is a positioning target area, which is an area in which the positioning system included in the access control system100can locate the smartphone200. That is, the area in which the transmitting and receiving part110can communicate is the same as the positioning target area of the positioning system. The positioning target area will be described later with reference toFIG.2, and the distance calculation process and angle calculation process will be described later in detail with reference toFIG.3. Also, the positioning system according to the embodiment will be described later with reference toFIG.3.

FIG.2is a plan view that shows an example of a positioning target area10A.FIG.2is a transparent plan view of the room10R seen from above the ceiling. The transmitting and receiving part110is provided at the center of the ceiling of the room10R. Also, inFIG.2, an automatic gate13is shown in addition to the automatic gates11and12. The automatic gate13is substantially the same as the automatic gates11and12, and provided opposite the automatic gate11. InFIG.2, the automatic gate13is closed.

The positioning target area10A is a three-dimensional area that covers substantially the entirety of the room10R, and includes determining areas11A to13A provided in front of the automatic gates11to13. The determining areas11A to13A are all three-dimensional areas that the access control system100uses when determining whether or not the smartphone200is present in front of the automatic gates11to13.

Also, the automatic gates11to13are the only side entrances for entering the room10R from outside the room10R. Therefore, in order to exit the room10R, it is necessary to walk through the automatic gate11,12, or13. The automatic gate11opens when the access control system100determines that the smartphone200is present in the determining area11A and the authentication is completed successfully. Similarly, the automatic gate12opens when the access control system100determines that the smartphone200is present in the determining area12A and the authentication is completed successfully. The automatic gate13opens when the access control system100determines that the smartphone200is present in the determining area13A and the authentication is completed successfully.

Note that, in order to open the automatic gate11,12, or13from the outside of the room10R, the process of determining whether or not a smartphone200is approaching and the authentication process may be performed by an access control system that is substantially the same as the access control system100, or the authentication and other processes may be performed based on different methods, or the authentication and other processes may be not performed.

<Structure of Access Control System100and Smartphone200>

FIG.3is a diagram that shows example structures of the access control system100and the smartphone200. The access control system100and the smartphone200perform packet communication based on Bluetooth (registered trademark) low energy, for example.

<Structure of Access Control System100>

The access control system100includes a transmitting and receiving part110and a control device120. The transmitting and receiving part110has three antennas111and a communication part115. The control device120is constituted by an MCU (Micro Controller Unit).

The antennas111are connected to the communication part115and receive signals transmitted from the smartphone200. Note that, althoughFIG.1shows a structure in which the access control system100has three antennas111, the access control system100may have four or more antennas111as well. The three antennas111are structured such that two antennas are placed on the first one of two axes that are orthogonal to each other, two antennas are placed on the second one of the two axes that are orthogonal to each other, and one of these antennas is placed on the first axis and on the second axis in common.

The communication part115includes an AFE (Analog Front End), an AD (Analog to Digital) converter, and so forth. The communication part115performs signal processing such as AD conversion on the signals that the antennas111receive from the smartphone200, and outputs them to the control device120.

The control device120includes a main control part121, a transmitting and receiving process part122, a distance calculation part123, an angle calculation part124, a determining part125, an authentication process part126, an opening and closing control part127, and a memory128. The opening and closing control part127is an example of the locking and unlocking part that is provided in the automatic gates11to13, and that locks and unlocks the automatic gates11to13on a switching basis. The memory128is an example of the storage part.

The control device120is implemented, for example, by a microcomputer including a CPU (Central Processing part), a RAM (Random Access Memory), a ROM (Read Only Memory), an internal bus, and so forth. The main control part121, transmitting and receiving process part122, distance calculation part123, angle calculation part124, determining part125, authentication process part126, and opening and closing control part127are functional blocks that control the functions of programs that the control device120executes. Also, the memory128is a functional representation of the memory of the control device120.

Here, the positioning system100A according to the embodiment has a structure in which the authentication process part126and the opening and closing control part127are omitted from the access control system100. Therefore, inFIG.3, the components of the positioning system100A are surrounded by broken lines. The positioning system100A includes a transmitting and receiving part110, a main control part121, a transmitting and receiving process part122, a distance calculation part123, an angle calculation part124, a determining part125, and a memory128.

The main control part121is a processing part that controls the entire control device120, and performs processes other than those performed by the transmitting and receiving process part122, distance calculation part123, angle calculation part124, determining part125, authentication process part126, and opening and closing control part127.

<Transmitting and Receiving Process Part122>

The transmitting and receiving process part122transmits and receives signals to and from the transmitting and receiving process part222of the smartphone200, in order to acquire the data that is needed when the distance calculation part123and angle calculation part124of the access control system100execute the distance calculation process and angle calculation process, such as signals' round trip time, phase differences, frequency components, and so forth. According to the present embodiment, for example, the distance calculation process for calculating the distance between the transmitting and receiving part110of the access control system100and the smartphone200is executed by the distance calculation part123of the access control system100. Also, the angle calculation process for calculating angles that indicate the position of the smartphone200with respect to the transmitting and receiving part110is executed by the angle calculation part124of the access control system100. The transmitting and receiving process part122therefore communicates with the transmitting and receiving process part222of the smartphone200and performs the following processes when the distance calculation part123and the angle calculation part124execute the distance calculation process and the angle calculation process.

The transmitting and receiving process part122transmits and receives signals to and from the transmitting and receiving process part222of the smartphone200when the distance calculation part123performs a TOA (Time of Arrival)-based distance calculation process. In this case, the transmitting and receiving process part122may transmit and receive signals using one of the three antennas111. The transmitting and receiving process part122calculates the phases of the signals received from the smartphone200. Also, the transmitting and receiving process part122receives data that represents phases from the smartphone200. The data representing phases shows, for example, the phase of a signal when the signal is received by the antenna211of the smartphone200.

Also, when the angle calculation part124performs the AOA (Angle of Arrival)-based angle calculation process, the transmitting and receiving process part122receives signals from the smartphone200by the three antennas111, calculates their phase differences when the signals are received by the three antennas111, and transmits data representing the calculated phase differences to the determining part125. Note that, when the AOA-based angle calculation process is performed, the three antennas111receive the signals transmitted from the transmitting and receiving process part222of the smartphone200for TOA-based distance-calculation, so that the transmitting and receiving process part122can transmit and receive the signals for TOA-based distance-calculation, and receive the signals for AOA-based angle calculation, all at the same time.

The distance calculation part123can execute a TOA-based distance calculation process. To execute the TOA-based distance calculation process, the distance calculation part123acquires the data that indicates the phase difference of each of multiple frequencies from the transmitting and receiving process part122, and calculates the distance between the transmitting and receiving part110of the access control system100and the smartphone200based on the relationships between the multiple phase differences and the frequencies. The distance between the transmitting and receiving part110of the access control system100and the smartphone200is, for example, the distance between the center of gravity of the three antennas111of the transmitting and receiving part110and the antenna211of the smartphone200. The distance calculated based on TOA method is significantly more accurate than the distance calculated based on the signal intensity of signals such as RSSI.

The angle calculation part124can execute an angle calculation process for calculating the angle of elevation and azimuth in the polar coordinate system of the position of the smartphone200with respect to the transmitting and receiving part110of the access control system100, by using the three antennas111, based on AOA method.

To be more specific, the angle calculation part124calculates the angle of elevation and azimuth based on AOA method, based on the phase differences when signals transmitted from the smartphone200are received by the three antennas111. The phase differences of the signals received by the three antennas111refer to the first phase difference between signals received by the two antennas111located on the first axis and the second phase difference between signals received by the two antennas111located on the second axis. The angle calculation part124calculates the azimuth, which indicates the position of the smartphone200with respect to the transmitting and receiving part110, from the ratio between the first phase difference and the second phase difference. Also, the angle calculation part124calculates the angle of elevation, which indicates the position of the smartphone200with respect to the transmitting and receiving part110, based on the azimuth and the first phase difference or the second phase difference. In the AOA-based angle calculation process, the angle of elevation and azimuth of the position of the smartphone200in the polar coordinate system with respect to the transmitting and receiving part110can be calculated. To be more specific, the position of the smartphone200with respect to the transmitting and receiving part110refers to the position of the antenna211of the smartphone200with respect to the position of the center of gravity of the three antennas111of the transmitting and receiving part110.

The determining part125determines whether or not the smartphone200is approaching the automatic gates11to13based on the distance calculated by the distance calculation part123and the angles calculated by the angle calculation part124. To be more specific, the determining part125determines whether the smartphone200is in any one of the determining areas11A to13A in front of the automatic gates11to13, based on position data that is stored in the memory128and that indicates the positions of the automatic gates11to13, the distance calculated by the distance calculation part123, and the angles calculated by the angle calculation part124. The presence of the smartphone200inside the determining area11A assures that the distance between the smartphone200and the automatic gate11is within a predetermined distance. This also applies to the determining areas12A and13A.

The authentication process part126executes an authentication process using the identifier of the smartphone200. Note that the authentication process part126may perform an authentication process using biological information of the user20(for example, face verification, fingerprint verification, etc.), or perform an authentication process using identification information that the user20carries with him/her (employee ID, student ID, etc.). The biological information of the user20and the identification information that the user20carries with him/her are examples of the identifier of the user20.

<Opening and Closing Control Part127>

The opening and closing control part127performs a process for locking and unlocking the automatic gates11to13on a switching basis. To be more specific, when the determining part125determines that the distance between the smartphone200and the automatic gate11is within a predetermined distance (the smartphone200is in the determining area11A) and the authentication process part126determines that the authentication process is successfully completed, the opening and closing control part127unlocks the automatic gate11. The opening and closing control part127performs substantially the same process for the automatic gates12and13.

The memory128stores the programs and data that are needed when the main control part121, transmitting and receiving process part122, distance calculation part123, angle calculation part124, determining part125, authentication process part126, and opening and closing control part127perform their processes.

The smartphone200includes an antenna211, a communication part215, and an MCU220. Each antenna211is connected to the communication part215and receives signals transmitted from the access control system100. The communication part215includes an AFE, an AD converter, and so forth, performs signal processing such as AD conversion on the signals received by the antenna211, and outputs it to the MCU220. Note that, although the smartphone200illustrated here has only one antenna211, it may have multiple antennas211.

The MCU220includes a main control part221, a transmitting and receiving process part222, and a memory233.

The main control part221and the transmitting and receiving process part222represent the functions of programs executed by the MCU220as functional blocks. Also, the memory233is a functional representation of the memory of the MCU220.

The main control part221is a processing part that controls the entire MCU220, and performs processes other than those executed by the signal intensity calculation part232. The main control part221executes processes for implementing various functions of the smartphone200.

<Transmitting and Receiving Process Part222>

The transmitting and receiving process part222transmits and receives signals to and from the transmitting and receiving process part122of the control system100, in order to acquire the data that is needed when the distance calculation part123and the angle calculation part124of the access control system100perform the distance calculation process and the angle calculation process, such as phase differences, frequency components, and so forth.

When the distance calculation part123of the access control system100performs a TOA-based distance calculation process, the transmitting and receiving process part222and the transmitting and receiving process part122of the access control system100transmit TOA signals of multiple frequencies to each other bidirectionally. In this case, the transmitting and receiving process part222calculates the phases of the TOA signals received from the access control system100, and transmits data that indicates the phases to the transmitting and receiving process part122of the access control system100. The data that indicates the phases shows the phases of the TOA signals when they are received by the antenna211of the smartphone200.

The memory233stores the programs, data, and so forth that are needed when the main control part221and the transmitting and receiving process part222execute their processes.

FIG.4is a diagram that shows an example of the determining area11A.FIG.4shows the determining area11A, which is set in front of the automatic gate11. InFIG.4, XYZ coordinates are defined.

Also,FIG.4shows the reference coordinates (X1, Y1, Z1) of the automatic gate11. The reference coordinates (X1, Y1, Z1) of the automatic gate11are the XYZ coordinates of the reference point of the automatic gate11. The reference point of the automatic gate11is, for example, the coordinates of the center of the automatic gate11in the X direction, Y direction, and Z direction. Data to represent these reference coordinates (X1, Y1, Z1) of the automatic gate11and data to represent the length of the automatic gate11in the X direction, Y direction, and Z direction may be stored in advance in the memory128.

The determining area11A is an area in which the X coordinate is greater than a threshold AX1and less than a threshold AX2, the Y coordinate is greater than a threshold AY1and less than a threshold AY2, and the Z coordinate is greater than a threshold AZ1and less than a threshold AZ2. Note that the threshold AX2is greater than the threshold AX1, the threshold AY2is greater than the threshold AY1, and the threshold AZ2is greater than the threshold AZ1. That is, insofar as the XYZ coordinates of the smartphone200hold in accordance with AX1<X<AX2, AY1<Y<AY2, and AZ1<Z<AZ2, it then follows that the smartphone200is present in the determining area11A.

FIG.5is a flowchart that shows examples of process steps (part1) executed by the control device120of the access control system100.FIG.5shows the process steps executed by the transmitting and receiving process part122, distance calculation part123, angle calculation part124, and determining part125, in relationship to the positioning system100A of the control device120of the access control system100.

When the process steps start, the transmitting and receiving process part122performs the transmitting and receiving process of TOA signals with the transmitting and receiving process part222of the smartphone200. The angle calculation part124performs an AOA-based angle calculation process (step S1).

The distance calculation part123performs a TOA-based distance calculation process (step S2).

The determining part125determines the XYZ coordinates of the smartphone200by using the angles (elevation angle φ and azimuth θ) determined in the angle calculation process, and the distance r determined in the distance calculation process (step S3). Note that the XYZ coordinates can be determined as follows by using the angles (elevation angle φ and azimuth θ) and the distance r: X=rsin θ cos φ, Y=rsin θ sin φ, and Z=rcosθ.

The determining part125determines whether or not the XYZ coordinates of the smartphone200hold in accordance with AX1<X<AX2, AY1<Y<AY2, and AZ1<Z<AZ2(step S4).

If the determining part125determines that the XYZ coordinates of the smartphone200hold in accordance with AX1<X<AX2, AY1<Y<AY2, and AZ1<Z<AZ2(S4: YES), the determining part125determines that the smartphone200is present in the determining area11A (step S5).

If, in step S4, the determining part125determines that the XYZ coordinates of the smartphone200do not hold in accordance with AX1<X<AX2, AY1<Y<AY2, and AZ1<Z<AZ2(S4: NO), the determining part125determines whether or not the XYZ coordinates of the smartphone200hold in accordance with BX1<X<BX2, BY1<Y<BY2, and BZ1<Z<BZ2(step S6).

If the determining part125determines that the XYZ coordinates of the smartphone200hold in accordance with BX1<X<BX2, BY1<Y<BY2, and BZ1<Z<BZ2(S6: YES), the determining part125determines that the smartphone200is present in the determining area12A (step S7).

Also, if, in step S6, the determining part125determines that the XYZ coordinates of the smartphone200do not hold in accordance with BX1<X<BX2, BY1<Y<BY2, and BZ1<Z<BZ2(S6: NO), the determining part125determines whether or not the XYZ coordinates of the smartphone200hold in accordance with CX1<X<CX2, CY1<Y<CY2, and CZ1<Z<CZ2(step S8).

When the determining part125determines that the XYZ coordinates of the smartphone200hold in accordance with CX1<X<CX2, CY1<Y<CY2, and CZ1<Z<CZ2(S8: YES), the determining part125determines that the smartphone200is present in the determining area13A (step S9).

Also, if, in step S9, the determining part125determines that the XYZ coordinates of the smartphone200do not hold in accordance with CX1<X<CX2, CY1<Y<CY2, and CZ1<Z<CZ2(S8: NO), the determining part125determines that the smartphone200is not present in the determining areas11A to13A (step S10). That is, although the smartphone200is in the room10R, the smartphone200is determined not to be present in any of the determining areas11A to13A.

This completes the series of process steps. The process shown inFIG.5is repeated in a predetermined control cycle.

FIG.6is a flowchart that shows examples of process steps (part2) executed by the control device of the access control system.

The determining part125determines whether or not the smartphone200is present in any one of the determining areas11A to13A (step S11). The determining part125determines whether or not the smartphone200is present in any of the determining areas11A to13A based on the determination results of steps S5, S7, S9, and S10.

When the determining part125determines that the smartphone200is present in one of the determining areas11A to13A (S11: YES), the authentication process part126performs an authentication process by using the identifier of the smartphone200(step S12).

The authentication process part126determines whether or not the authentication by the authentication process is successfully completed (step S13).

When the authentication process part126determines that the authentication by the authentication process is successfully completed (S13: YES), the opening and closing control part127unlocks and opens the automatic gate11,12, or13that corresponds to the determining area (one of the determining areas11A to13A) where the smartphone200is determined to be present (step S14).

When a predetermined period of time passes after the smartphone200moves out of the positioning target area10A through the automatic gate (one of the automatic gates11to13), the opening and closing control part127closes and locks the automatic gate (step S15). This is to prevent users who are not successfully authenticated from entering or exiting the place. The predetermined time is, for example, approximately 1 to 2 seconds.

This completes the series of process steps (END). The process shown inFIG.6is repeated in a predetermined control cycle.

Note that if, in step S11, the determining part125determines that the smartphone200is not present in any of the determining areas11A to13A (S11: NO), the series of process steps may be ended here (END). In this case, the process ends without opening any of the automatic gates11to13.

Also, if, in step S13, the authentication in the authentication process part126is not successfully completed (S13: NO), the series of process steps may be ended here (END). If the authentication is not successfully completed, the process ends without opening any of the automatic gates11to13.

The positioning system100A includes: a transmitting and receiving part110that has multiple antennas111and is positioned overhead in a positioning target area10A where automatic gates11and12are provided; a distance calculation part123that calculates the distance between a smartphone200, which can move inside the positioning target area10A, and the transmitting and receiving part110, based on results gained from signals of multiple frequencies transmitted bidirectionally between the mobile smartphone200and the transmitting and receiving part110; an angle calculation part124that calculates angles that indicate the position of the smartphone200with respect to the transmitting and receiving part110, based on phase differences between the signals that the multiple antennas111of the transmitting and receiving part110receive from the smartphone200; and a determining part125that determines whether or not the smartphone200is approaching the automatic gates11and12, based on the distance calculated by the distance calculation part123and the angles calculated by the angle calculation part124.

Therefore, by means of the TOA-based distance calculation process and the AOA-based angle calculation process, whether or not the smartphone200is approaching the automatic gates11and12can be determined accurately. In particular, the TOA-based distance calculation process is affected less by the impact of multi-path signals and the like, and therefore enables accurate distance calculation compared to a distance calculation process based on signal intensity such as RSSI.

Therefore, it is possible to provide a positioning system100A whereby the position of the smartphone200can be calculated accurately. Also, provided that the access control system100includes a positioning system100A, it is possible to provide an access control system100whereby the position of the smartphone200can be calculated accurately.

Also, the access control system100further includes a memory128that stores position data that indicates the positions of the automatic gates11and12, and the determining part125determines whether or not the smartphone200is approaching the automatic gates11and12based on the position data, the distance calculated by the distance calculation part123, and the angles calculated by the angle calculation part124.

Consequently, it is possible to provide a positioning system100A whereby, by using the position data that indicates the positions of the automatic gates11and12, the position of the smartphone200with respect to the automatic gates11and12can be calculated more accurately.

Also, the access control system100includes: a positioning system100A; an authentication process part126that can execute an authentication process by using an identifier of the smartphone200or an identifier of a moving object that can move with the smartphone200; and an opening and closing control part127that locks and unlocks the automatic gates11and12on a switching basis, and, in this access control system100, when the determining part125determines that the distance between the smartphone200and the automatic gate11or12is within a predetermined distance, and the authentication process part126determines that the authentication process by the authentication process part126is successfully completed, the opening and closing control part unlocks the automatic gate11or12.

Therefore, it is possible to provide an access control system100whereby, when authentication is successfully completed, the automatic gates11or12can be unlocked by using an accurately calculated position of the smartphone200with respect to the automatic gates11and12.

Also, in the access control system100, when a predetermined period of time passes after the smartphone200moves out of the positioning target area10A through the automatic gate11or12, the opening and closing control part127locks the gate.

Therefore, by using an accurately calculated position of the smartphone200with respect to one of the automatic gates11to13, when a predetermined period of time passes after the smartphone200moves out of the positioning target area10A through one of the automatic gates11to13, the gate that is open can be locked. Consequently, it is possible to provide an access control system100, whereby the entry and exit of users can be controlled accurately by using accurately calculated positions of smartphones200with respect to any of the automatic gates11to13, and whereby the entry and exit of unauthorized persons can be strictly prevented.

A positioning method for use in a positioning system100A including: a transmitting and receiving part110that has multiple antennas111and is positioned overhead in a positioning target area10A where automatic gates11and12are provided; a distance calculation part123that calculates the distance between a smartphone200, which can move inside the positioning target area10A, and the transmitting and receiving part110, based on results gained from signals multiple of frequencies transmitted bidirectionally between the mobile smartphone200and the transmitting and receiving part110; and an angle calculation part124that calculates angles that indicate the position of the smartphone200with respect to the transmitting and receiving part110, based on phase differences between the signals that the multiple antennas111of the transmitting and receiving part110receive from the smartphone200, determines whether or not the smartphone200is approaching the automatic gate11or12based on the distance calculated by the distance calculation part123and the angles calculated by the angle calculation part124.

Therefore, it is possible to accurately determine whether or not the smartphone200is approaching the automatic gates11and12, based on the TOA-based distance calculation process and the AOA-based angle calculation process. In particular, the TOA-based distance calculation process is affected less by the impact of multi-path signals and the like, and enables accurate distance calculation compared to a distance calculation process based on signal intensity such as RSSI.

Therefore, it is possible to provide a positioning method whereby the position of the smartphone200can be calculated accurately.

Now, although examples of the positioning system, access control system, and positioning method of the present disclosure have been described above, the present disclosure is by no means limited to the examples described in detail herein, and a variety of alterations and changes can be made without departing from the scope of the claims attached herewith.