KR20160060994A - System and Method for control door open and shut, and device thereof - Google Patents

Abstract

According to the present invention, disclosed are a system and a method for controlling opening/closing of a door, and an apparatus therefor. More particularly, the apparatus for controlling opening/closing of a door comprises: an antenna unit having a plurality of antennas to transmit/receive radio frequency signals; and a controller which receives the radio frequency signals from a radio frequency identification (RFID) tag installed on the door through the antenna unit, identifies the door on the basis of identification information of the tag contained in the radio frequency signals, and determines the extent of opening of the door by identifying an antenna received the radio frequency signals among the antennas contained in the antenna unit.

Description

FIELD OF THE INVENTION The present invention relates to a door open / close control system and method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door opening / closing control method, and more particularly, to a door opening / closing control system and method for automatically detecting opening and closing of a door, and an apparatus therefor.

Security is very important for doors, windows, and so on, so that only those who have access to the entrance, windows, Generally, locks and the like are provided at a doorway where only authorized persons can access the room, which is important and confidential, so that only a person having a key can enter and exit the room.

In recent years, as user authentication devices using near-field communication technology such as RFID (Radio Frequency IDentification) have been developed, RFID door lock devices are installed in entrance and the like, and only those possessing an RFID card necessary for user authentication So that it can be opened.

However, in the case of the above RFID door lock device, since the user authentication is successful even if the RFID card is carried, it is difficult to closely monitor the intrusion of the outsider. In addition, the above RFID door locking device only provides a function for authenticating a user, so that an emergency situation can not be provided or a function of controlling a doorway, a window, and the like can not be automatically provided according to a surrounding situation.

Korean Patent Laid-Open No. 10-2009-0089191, published on Aug. 21, 2009 (name: RFID ID terminal, control method thereof, door opening / closing device using the same, and power supply device)

An object of the present invention is to provide a door opening and closing control system and method for automatically opening and closing a door by monitoring a door opening and closing state of a door and a window having a unique identification ID, I suggest.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, unless further departing from the spirit and scope of the invention as defined by the appended claims. It will be possible.

According to one aspect of the present invention, there is provided an apparatus for controlling the opening and closing of a door, comprising: an antenna unit including a plurality of antennas for transmitting and receiving a radio frequency signal; A radio frequency identification (RFID) system, comprising: a radio frequency identification (RFID) tag; a radio frequency identification (RFID) tag that identifies the door based on identification information of the tag included in the radio frequency signal; And a control unit for determining the degree of opening of the door by identifying the antenna that receives the antenna.

According to another aspect of the present invention, there is provided a method for controlling opening and closing of a door, the method comprising the steps of: receiving a radio frequency signal from an RFID (Radio Frequency Identification) tag mounted on the door; Wherein the door open / close control device identifies the door based on the identification information of the tag included in the radio frequency signal, and the door open / close control device receives the radio frequency signal among the plurality of antennas included in the door open / And discriminating an opening degree of the door by identifying one antenna.

Preferably, the door can be opened and closed by transmitting a drive control signal for opening and closing the door to the drive unit.

Preferably, the opening degree of the door can be adjusted by driving the driving device so that the tag can be identified to any one of the plurality of antennas.

Preferably, the antenna unit may be a switched loop antenna array having a circular DGS (Defected Ground Structure).

Preferably, the switching loop antenna array may comprise a plurality of loop antenna arrays for tag identification at each loop point, a switch for loop switching, and a ground plane having a circular DGS .

According to the embodiments of the present invention, it is possible to provide effects such as security monitoring and automatic ventilation by sensing opening and closing of windows and door devices such as houses, buildings, agricultural houses, etc., and automatically controlling opening and closing.

In addition, according to the embodiment of the present invention, since the opening and closing states of doors, windows, and the like are wirelessly sensed, the present invention can be utilized without any restriction on day or night.

The effects obtained in the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description .

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the technical features of the invention.
1 is a diagram illustrating a door opening / closing control system according to an embodiment of the present invention.
2 is a view illustrating a door open / close control method according to an embodiment of the present invention.
3 is a view for explaining a method of determining the opening and closing state of a door according to an embodiment of the present invention.
FIG. 4 illustrates a structure of a near-field switched loop antenna array having a circular DGS according to an embodiment of the present invention.
5 is a diagram illustrating the characteristics of a near-field switching loop antenna array according to an embodiment of the present invention.
6 is a diagram illustrating experimental results of a near-field switching loop antenna array according to an embodiment of the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or may be shown in block diagram form, centering on the core functionality of each structure and device, to avoid obscuring the concepts of the present invention.

Throughout the specification, when an element is referred to as "comprising" or " including ", it is meant that the element does not exclude other elements, do. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have. Also, the terms " a or ", "one "," the ", and the like are synonyms in the context of describing the invention (particularly in the context of the following claims) May be used in a sense including both singular and plural, unless the context clearly dictates otherwise.

The specific terminology used in the following description is provided to aid understanding of the present invention, and the use of such specific terminology may be changed into other forms without departing from the technical idea of the present invention.

1 is a diagram illustrating a door opening / closing control system according to an embodiment of the present invention.

Referring to FIG. 1, a door opening / closing control system 100 according to the present invention detects an opening / closing state of a door installed in a home, a building, an agricultural electronic house, and the like, And includes at least one tag 110, a door opening / closing control device 120, and at least one driving device 130. The door opening /

The configuration of the door opening and closing control system 100 shown in FIG. 1 shows functional elements that are functionally separated, and any one or more configurations may be physically integrated or separated from one another.

Hereinafter, 'door' refers to a house or a building, an electronic house / greenhouse for agricultural use, a window or a door installed in a car, or the like.

In the present invention, the communication between the tag 110 and the door open / close control device 120 is performed using a short distance communication method. Here, an RFID (Radio Frequency IDentification) and NFC (Near Field Communication) .

That is, the door opening / closing control device 120 operates as an RFID (or NFC) reader and can operate as an RFID (or NFC) tag. The door opening and closing control device 120 emits a radio frequency signal and the tag 110 modulates the phase or the amplitude of the received radio frequency signal to transmit the data stored in the tag 110 (E.g., identification information of the radio frequency response signal). The door opening / closing control device 120 can read the data stored in the tag 110 by receiving the radio frequency response signal from the tag 110. [ Here, the RFID includes an LF (Low-Frequency) RFID using a frequency of 120-140 KHz band, a HF (High-Frequency) RFID using a frequency of 13.56 MHz band, and an UHF (UltraHigh-Frequency) RFID of 868-956 MHz do.

The tag 110 according to the present invention may be composed of an antenna and an integrated circuit for receiving a near-field radio frequency signal. The tag 110 may be mounted on one end of the door to discriminate the open / closed state of the door. Here, each of the tags 110 may be mounted on a different door, or a plurality of tags 110 may be mounted on one door by forming a group.

The door opening / closing control device 120 according to the present invention is installed in the door frame to discriminate the open / close state of one or more doors through short-range communication with the tag 110 mounted on one end of the door, Device.

Here, the opening / closing state of the door includes not only the opening and closing of the door but also the door opening information (for example, how many degrees the door is open when the door is open and how many cm is opened when the door is a sliding door).

The door opening and closing control apparatus 120 according to the present invention may include an antenna unit 121, a control unit 123, and a storage unit 125.

The antenna unit 121 may be an array of a plurality of antennas (antenna 1, antenna 2, ..., antenna n). A near-field switched loop antenna array may be used as an example of the antenna unit 121. [ A detailed description of a near-field switched loop antenna array will be given later.

Each antenna included in the antenna unit 121 radiates a radio frequency signal and receives a radio frequency response signal from the tag 110. As described above, the radio frequency response signal from the tag 110 includes the identification information (ID) of the tag 110.

The control unit 123 identifies the tag 120 mounted on the door and determines the opening / closing state of the door from the position where the tag 110 is identified.

More specifically, the controller 123 determines the position of the tag 110 by determining which of the plurality of antennas included in the antenna unit 121 receives a radio frequency response signal from the tag 110. For example, when the door is a sliding door, a plurality of antennas are arranged in a line so that the positions of the antennas included in the antenna unit 121 are spaced apart from each other in the door frame, The position of the tag 110 can be determined.

That is, the controller 123 identifies the door by discriminating the ID of the tag 110 included in the radio frequency response signal from the tag 110, and transmits the radio frequency response signal received from the tag 110 to the antenna 121 And determines the exact position of the tag 110 by determining whether the tag 110 is received. Thus, by determining the precise position of the tag 110 mounted on one end of the door, it is possible to determine which door is currently opened or closed and which door is currently opened to some extent.

In addition, the control unit 123 transmits a drive control signal for driving the door to the drive unit 130, thereby operating the door opening / closing operation.

Here, the control unit 123 determines whether or not the current open / close state is in a suitable state, and can control to change the open / close state of the door when it is not suitable (i.e., change of the open / close state is required). For example, when the controller 123 is set to close a predetermined door at a predetermined time interval (for example, in the case of a building door from 9:00 pm to 6:00 am the next day) When the set time interval comes, it is possible to detect whether the predetermined door is closed by sensing the tag 110, and if not, the driving control signal can be transmitted to the driving device 130 so as to close the door.

In addition, the controller 123 transmits the door open / close status information to the user device in real time or with a predetermined period. When the door open / close instruction signal is received from the user device, So as to drive the opening or closing of the door.

The control unit 123 controls the antenna unit 121 such that the position of the tag 110 is determined according to which antenna among the plurality of antennas belonging to the antenna unit 121 The degree of opening of the door can be adjusted by driving the driving device 130 so that the tag 110 can be identified from a specific antenna among a plurality of antennas to which the antenna 110 belongs. That is, the degree of opening of the door can be finely controlled by driving the driving device 130 so that the tag 110 mounted on one end of the door is identified by the specific antenna. In this case, the control unit 123 may transmit identification information about the specific antenna to the driving control information to be transmitted to the driving unit 130.

For example, when the door is a sliding door, a plurality of antennas are arranged in a line so that the positions of the respective antennas included in the antenna unit 121 are spaced apart from the frame of the door, The degree of opening and closing of the door can be adjusted by driving the driving device 130 so as to be identified by the antenna 2.

At this time, the control unit 123 may transmit a drive control signal for door opening / closing operation to the driving unit 130 through the antenna unit 121 in a short distance communication manner, but may be a separate wireless communication module (for example, Local area network (LAN), etc.) for driving the door.

The storage unit 125 is connected to the control unit 123 and stores various information for driving the control unit 123. For example, when the predetermined door is set to be closed for a predetermined period of time as described above, identification information of the tag 110 mounted on the predetermined door and information on the time interval can be stored.

Upon receiving the drive control signal for the door opening / closing operation received from the door opening / closing control device 120, the driving device 130 converts the driving control signal into power to operate the opening and closing of the door.

The driving device 130 may be implemented as a separate device from the tag 110 and / or the door opening / closing control device 120 as shown in FIG. However, the present invention is not limited to this, and the tag 110 may be provided in the driving unit 130 or physically integrated with the door opening / closing control unit 120.

2 is a view illustrating a door open / close control method according to an embodiment of the present invention.

Referring to FIG. 2, the door open / close control device 120 emits a radio frequency signal using a short-distance wireless communication method (for example, RFID, NFC, etc.) (S201).

The tag 110 which receives the radio frequency signal from the door opening and closing control device 120 transmits a radio frequency response signal as a response signal to the tag 110. The door opening and closing control device 120 receives the radio frequency response signal from the tag 110 (S203).

The door opening / closing control device 120 identifies the door based on the tag identification information (ID) included in the radio frequency response signal received from the tag 110 (S205).

Then, the door opening / closing control device 120 identifies the opening degree of the door by discriminating the antenna of the door opening / closing control device 120 that received the radio frequency response signal transmitted from the tag 110 (S207).

That is, the door opening / closing control device 120 determines the exact position of the tag 110 by determining which antenna of the door open / close control device 120 receives the radio frequency response signal received from the tag 110, The degree of opening of the current door can be determined by determining the exact position of the tag 110 mounted on one end of the door.

Then, the door opening / closing control device 120 transmits a driving control signal for door opening / closing driving to the driving device 130 so as to open / close the door (S209).

At this time, the door opening / closing control device 120 may control the opening degree of the door by driving the driving device 130 so that the tag 110 can be identified from a specific antenna among the plurality of antennas.

3 is a view for explaining a method of determining the opening and closing state of a door according to an embodiment of the present invention.

3 (a) shows an example in which a tag 110 and a door opening / closing control device 120 (particularly, an antenna) are mounted on a sliding door. FIG. 3 (b) And a door opening / closing control device 120 (particularly, an antenna) are mounted.

3A, four antennas 311, 313, 315, and 317 belonging to the antenna unit 121 of the door opening and closing control device 120 are arranged in a row on the frame of the door, It is assumed that the tag 319 is mounted.

Here, it is assumed that each of the antennas 311, 313, 315, and 317 is spaced apart by 10 cm. In this case, if the door is completely closed or opened at a distance of 10 cm or less, the tag 319 is identified by the fourth antenna 317 from above, and when the door is opened by about 10-20 cm, Identifies the tag 319 on the second antenna 313 from the top when the door is opened by about 20-30 cm, and if the door is opened by about 30-40 cm on the second Lt; RTI ID = 0.0 > 311 < / RTI >

The door open / close control device 120 (i.e., the control unit 123) determines the open / closed state of the door by receiving the radio frequency response signal received from the tag 319 through the respective antennas 311, 313, 315, can do. That is, the door opening / closing control device 120 (that is, the control unit 123 determines which door is the door through the identification information of the tag 319, and determines the opening degree of the door according to which antenna identifies the tag 319 Can be distinguished.

Referring to FIG. 3B, four antennas 321, 323, 325 and 327 belonging to the antenna unit 121 of the door opening / closing control device 120 are arranged in an elliptical shape in which doors are opened, And a tag 329 is mounted at one end.

Here, it is assumed that the respective antennas 321, 323, 325, and 327 are spaced apart at an interval of 20 degrees from the fully closed state of the door. In this case, if the door is completely closed or open at less than 20 degrees, the first antenna 321 identifies the tag 329, and if the door is open about 20-40 degrees, the second antenna 323 Identifies the tag 329 and identifies the tag 329 at the third antenna 325 when the door is open about 40-60 degrees and identifies the tag 329 at the fourth antenna 327 if the door is open about 60-80 degrees. The tag 329 may be identified.

The door open / close control device 120 (i.e., the control unit 123) determines whether the door is open or closed by receiving the radio frequency response signal received from the tag 329 through the respective antennas 321, 323, 325, can do. That is, the door opening / closing control device 120 (that is, the control unit 123) determines which door is the door through the identification information of the tag 329. Depending on which antenna identifies the tag 329, Can be determined.

Further, the tag 110 and the door opening / closing control device 120 (particularly, the antenna) may be mounted in the opposite manner.

Referring again to FIG. 3A, four tags 311, 313, 315, and 317 having different identification information are arranged in a line on a frame of a door, and a door opening and closing control device 120 can be mounted.

In this case, the door opening / closing control device 120 identifies the different tags 311, 313, 315, and 317 through the antenna 319, and can determine the degree of opening of the door according to the tag to be identified.

Here, it is assumed that the tags 311, 313, 315, and 317 are spaced apart by 10 cm. In this case, when the door is completely closed or opened up to 10 cm or less, the fourth tag 317 from above is recognized by the antenna 319, and when the door is opened by about 10-20 cm, the third tag 315 Is identified at the antenna 319 and the second tag 313 is identified at the antenna 319 from above when the door is opened by about 20-30 cm and when the door is opened by about 30-40 cm The first tag 311 may be identified at the antenna 319.

Thus, by receiving the radio frequency response signals received from the respective tags 311, 313, 315, and 317, the door open / close control device 120 (i.e., the control unit 123) . That is, the door opening / closing control device 120 (that is, the control unit 123 can determine the degree of opening of the door through the identification information of the tag 319).

3B, the four tags 321, 323, 325, and 327 are spaced apart at an interval of 20 degrees from the fully closed state of the door, and the antenna 329 is mounted at one end of the door And detailed description thereof will be omitted.

3, a plurality of antennas or a plurality of tags is assumed to be four, but this is merely for convenience of description, and the present invention is not limited thereto.

As described above, a near-field switching loop antenna array may be used as an example of the antenna unit 121 of the door opening / closing control device 120 according to the present invention.

Hereinafter, a near-field switched loop antenna array will be described.

For a precise position location system, the present invention proposes a switched loop antenna array with a circular DGS (Defected Ground Structure). A near-field switched loop antenna array can identify the location of compactly located RFID tags by switching the loop array.

In recent years, high inventory losses have been caused by theft, and item-level tagging (ILT) for precise inventory management is required not only in the production line but also in retail stores.

However, due to multipath fading, item level RFID is not easy to install in areas of retail stores where items are densely populated, particularly in small areas where cosmetics and medical devices are located. For near positional positioning it is also desirable to use a near UHF (short-range) antenna with optimal short-range performance to reduce proximity effects on effects that limit RF transmission of items such as liquid, powder and metal packaging. (ultra-high frequency) reader antenna has been studied.

In order to prevent dead zones where tags do not react immediately within the interrogation zone, existing antennas for uniform field distribution exclude position location functions in near-field ILT applications Used a segmented loop antenna or two coupled patches. In addition, a position-location system based on far-field UHF RFID-based position locating or passive tags using detection of tag interference has been proposed. However, it is difficult to detect and find the precise position of a small tag in the ILT.

Accordingly, the present invention proposes a near-field switched loop antenna array having a circular DGS for a precise location positioning system.

FIG. 4 illustrates a structure of a near-field switched loop antenna array having a circular DGS according to an embodiment of the present invention.

FIG. 4A shows the geometry of the near-field switching loop antenna array, and FIG. 4B shows an impedance matching network (IMN) including a balanced balun (LC balun). do.

Referring to FIG. 4, the near-field switching loop antenna array according to the present invention includes a four-layer printed circuit board substrate (FR4) having a dielectric constant of 4.5 and a thickness of 1.8 mm. .

The near-field switching loop antenna array includes a 2 X 2 loop antenna array including an impedance matching network (IMN, FIG. 4 (b)) for tag identification at each loop position, as shown in FIG. 4 (a) A single pole four throw switch (SP4T) for a single pole for loop switching and a ground plane having a circular DGS. Although the tags are densely located in the loop array, the proposed near-field switching loop antenna array can precisely identify the tags in each loop antenna.

Here, although the structure of the loop antenna array is described as 2 X 2, this is for convenience of explanation, and the present invention is not limited thereto. That is, the structure of the loop antenna array may be variously configured such as 1 X 4, 2 X 6, and the like.

The near-field switching loop antenna array has main geometrical parameters such as the distance L between the antenna arrays, the loop radius r, the loop width w, the gap g between the loop and the DGS, and the load resistance R _L parameters). The overall size of the proposed array is 80 X 80 mm 2 and the loop radius r is about λ / 5 where λ is the wavelength at the center frequency of 902-928 MHz licensed for UHF RFID applications. Lt; / RTI > The IMN of the loop antenna can be implemented by a series capacitance (C ₁ ) for resonance and a balanced-to-unbalanced LC balun (C ₂ and L ₂ ). The antenna input impedance Z _in is 50 ohms and the antenna load impedance Z _L is determined by the loop radius r and the load resistance R _L.

5 is a diagram illustrating the characteristics of a near-field switching loop antenna array according to an embodiment of the present invention.

5 (a) shows a magnetic field (H _z -field) distribution for comparing the influence of DGS in a single loop of a near-field switching loop antenna array. In the case of a single loop without a ground plane, it is difficult to identify the precise location of the tag because the magnetic field (H _z -field) spreads widely. On the other hand, the magnetic field (H _z -field) in the proposed single antenna is limited to the loop region due to DGS.

Figure 2 (b) shows the simulated and measured matching performance of the proposed array with a reflection coefficient of -10 dB over the operating frequency band.

2 (c) shows the magnetic field (H _z -field) and the antenna quality index (Q-factor) with respect to the load resistance R _L.

6 is a diagram illustrating experimental results of a near-field switching loop antenna array according to an embodiment of the present invention.

As shown in FIG. 6, the tag identification of the proposed array is verified by switching the near-field switching loop antenna array at a specific distance (h = 10 mm, 20 mm, 30 mm). Depending on the different loop positions, the proposed array can identify near-field UHF RFID tags at a maximum distance of 30 mm.

In the present invention, a switched loop array having a circular DGS that confines a magnetic field in a loop region is proposed for precise position location detection using near-field UHF RFID technology. The proposed near-field switching loop antenna array demonstrates the ability of precise location positioning through electrical loop switching. If the proposed loop is used, it is suitable for a precise position locating system for ILT of dense and small items.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) field programmable gate arrays, processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, or the like which performs the functions or operations described above. The software code can be stored in memory and driven by the processor. The memory is located inside or outside the processor and can exchange data with the processor by various means already known.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the foregoing detailed description is to be considered in all respects illustrative and not restrictive. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

The door opening / closing control scheme according to the present invention can be applied to a house or a building, an electronic house / greenhouse for agricultural use, a window or a door installed in an automobile or the like.

100: door opening / closing control system 110: tag
120: Door opening / closing control device 121: Antenna part
123: control unit 125:
130: Driving device

Claims (6)

An apparatus for controlling the opening and closing of a door,
An antenna unit including a plurality of antennas for transmitting and receiving a radio frequency signal; And
The radio frequency identification system includes a radio frequency identification (RFID) tag, a radio frequency identification (RFID) tag attached to the door through the antenna, identification of the door based on identification information of the tag included in the radio frequency signal, And a control unit for identifying an antenna that receives the radio frequency signal from the plurality of antennas to determine the degree of opening of the door.
The method according to claim 1,
Wherein the control unit transmits a drive control signal for driving the door to the drive unit to operate the door.
3. The method of claim 2,
And the controller controls the degree of opening of the door by driving the driving device so that the tag can be identified to any one of the plurality of antennas.
The method according to claim 1,
Wherein the antenna unit comprises a switched loop antenna array having a circular DGS (Defected Ground Structure).
5. The method of claim 4,
Wherein the switching loop antenna array comprises a plurality of loop antenna arrays for tag identification at each loop point, a switch for loop switching, and a ground plane having a circular DGS.
A method for controlling opening and closing of a door,
Receiving a radio frequency signal from an RFID (Radio Frequency Identification) tag mounted on the door;
The door opening and closing control device identifying the door based on the identification information of the tag included in the radio frequency signal; And
Wherein the door opening / closing control device identifies an antenna that receives the radio frequency signal among the plurality of antennas included in the door opening / closing control device, and determines the degree of opening of the door.

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