KR101634771B1 - Position detecting apparatus and control method of rfid reader for position detecting - Google Patents

Abstract

A position detecting apparatus for a moving means is disclosed. The apparatus includes: an RFID reader having an antenna and receiving first identification information from an RFID tag installed on a moving path of the moving means through the antenna; And a processor for detecting the position of the moving means using the first identification information, wherein the processor controls the radiation pattern of the antenna in consideration of the moving speed of the moving means.

Description

TECHNICAL FIELD [0001] The present invention relates to a position detecting apparatus and a control method of an RFID reader for detecting a position of the RFID reader,

The various embodiments described herein relate to location sensing of mobile means using RFID technology.

Techniques for detecting the position of the mobile means have been developed due to the introduction of GPS (Global Positioning System) and RFID (radio frequency identification) related technologies. In the case of a train, it is important not only for the convenience of the train but also for safety, to accurately locate the train. This is because a sufficient distance must be ensured for the braking of the train, so accurate position detection is required for safe braking of the train.

A related prior art is disclosed in Patent Publication No. 10-2010-0083051. This prior art document discloses a train operation control system using RFID and a control method thereof.

However, since the RFID reader of the above prior art uses an antenna having a fixed radiation pattern, it can not provide an accurate and efficient method for detecting the position of a train.

It is an object of the various embodiments described herein to recognize the RFID tag installed in the movement path of the moving means without missing and improve the efficiency of the energy consumed in recognizing the RFID tag.

According to one aspect, the position detecting device includes an RFID reader having an antenna and receiving first identification information from an RFID tag installed in a moving path of the moving means through the antenna; And a processor for detecting the position of the moving means using the first identification information, wherein the processor controls the radiation pattern of the antenna in consideration of the moving speed of the moving means.

According to one aspect of the present invention, a control method of an RFID reader for detecting the position of a moving means includes a step of detecting a moving speed of the moving means and a minimum value required for the RFID reader to receive identification information from the RFID tag through the antenna provided in the RFID reader Determining a radiation pattern of the antenna in consideration of power; And controlling a radiation pattern of the antenna based on the determined radiation pattern.

According to various embodiments described herein, the accuracy of position detection can be improved.

In addition, according to various embodiments described herein, the safety of the customer can be enhanced by accurately detecting the position of the train and securing the braking distance of the train.

In addition, according to various embodiments of the present invention, it is possible to provide the customer with high reliability information on the position of the moving means, thereby improving customer convenience.

Also, according to various embodiments described herein, RFID tags can be recognized without missing by supplying appropriate power to the RFID tags.

In addition, according to various embodiments described herein, it is possible to increase the efficiency of the power consumed in recognizing the RFID tag.

1 is a view for explaining an antenna control of an RFID reader according to an embodiment.
2 is a block diagram showing a position detecting apparatus according to an embodiment.
3 is a view for explaining a process of determining a radiation pattern according to an embodiment.
4 is a graph showing the relationship between the width of the radiation pattern and the moving speed of the moving means according to one embodiment.
FIG. 5 is a diagram illustrating a change in radiation pattern according to the moving speed of the moving means according to an embodiment.
6 is a diagram illustrating the structure of a database according to an embodiment.
7 is a flowchart illustrating a method of controlling an RFID interrogator according to an embodiment of the present invention.

In the following, embodiments will be described in detail with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

Various modifications may be made to the embodiments described below. It is to be understood that the embodiments described below are not intended to limit the embodiments, but include all modifications, equivalents, and alternatives to them.

The terms used in the examples are used only to illustrate specific embodiments and are not intended to limit the embodiments. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this embodiment belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

In the following description of the present invention with reference to the accompanying drawings, the same components are denoted by the same reference numerals regardless of the reference numerals, and redundant explanations thereof will be omitted. In the following description of the embodiments, a detailed description of related arts will be omitted if it is determined that the gist of the embodiments may be unnecessarily blurred.

1 is a view for explaining an antenna control of an RFID reader according to an embodiment.

1, the moving means 100, the moving path 10 of the moving means 100, the position detecting device 200, the radiation pattern 211, and the RFID tag 300 are shown.

The moving means 100 includes a train, a train, a train, a train, a train, a subway, a tram, an automobile, and a motorcycle which move on the movement route 10. [ The movement path 10 may be a path provided with a constant structure such as a railway to which the moving means 100 can move. In addition, the movement path 10 may be a path formed such that a plurality of movement means are repeatedly moved even if there is no constant structure for movement of the movement means 100.

The position detecting device 200 detects the position of the moving means 100 by recognizing the RFID tag 300. [ Further, the position detecting device 200 can be located at the moving means 100. [ The position detecting device 200 supplies power to the RFID tag 300 in order to recognize the RFID tag 300.

The position detecting apparatus 200 can detect the position of the moving means 100 by using the identification information of the RFID tag 300 received from the RFID tag 300. [ The position detecting device 200 will be described in detail with reference to FIG.

The RFID tag 300 transmits the identification information to the position detecting device 200 using the power received from the position detecting device 200.

The identification information may be information for distinguishing the RFID tag 300 from other RFID tags. The position detecting device 200 can detect the position of the moving means 100 by comparing the identification information with the information stored in the database.

The identification information may include location information of the RFID tag 300. In this case, the position detecting device 200 can detect the position of the moving means 100 through the identification information.

The RFID tag 300 may include an antenna for receiving power and transmitting identification information. In addition, the RFID tag 300 may include a memory for storing identification information and a capacitor for storing power. In addition, the RFID tag 300 may include a configuration necessary for performing RFID communication with the position detecting device 200. [

In order for the RFID tag 300 to transmit identification information, it must receive power exceeding a threshold value. When the RFID tag 300 receives power below the threshold value, the RFID tag 300 can not transmit the identification information. In addition, when the RFID tag 300 receives excess power, surplus power is generated. The position detecting device 200 can control the radiation pattern 211 so that the RFID tag 300 can receive proper power.

The position detecting device 200 can adjust the radiation pattern 211 in accordance with the moving speed of the moving means 100. For example, the position detecting device 200 can increase the width of the radiation pattern 211 when the moving means 100 travels at a high speed.

The width of the increased radiation pattern 211 in FIG. 1 is shown as BW _H. Further, the position detecting device 200 can reduce the width of the radiation pattern 211 when the moving means 100 travels at a low speed. The width of the reduced radiation pattern 211 in FIG. 2 is shown as BW _L. The process of determining the radiation pattern is described in detail in FIG.

The position detection apparatus 200 can control the radiation pattern 211 using an antenna array including a plurality of sub-antennas, a single antenna including a plurality of feeds, or a plurality of antennas having different radiation patterns. In addition, the position detecting device 200 can control the radiation pattern 211 by adjusting the power supplied to the antenna.

The position detecting device 200 can detect the RFID tag 300 without missing by transmitting power exceeding a threshold value for transmitting the identification information. In addition, the position detecting device 200 can improve the power efficiency by adjusting the radiation pattern 211 so that no surplus electric power is generated in the RFID tag 300.

2 is a block diagram showing a position detecting apparatus according to an embodiment.

Referring to FIG. 2, the position detecting apparatus 200 includes a processor 210 and an RFID reader 220. In addition, the position detection device 200 may optionally include a database 230, a communication unit 240, and a power supply unit. The RFID reader 220 may include a reader antenna 221.

The processor 210 detects the position of the moving means 100 using the first identification information received from the RFID tag 300 by the RFID reader 220 via the reader antenna 221. [

The first identification information may be information for distinguishing the RFID tag 300 from other RFID tags. In addition, the identification information may include the location information of the RFID tag 300.

The processor 210 can detect the position of the moving means 100 by using the position information of the RFID tag 300 included in the identification information. In addition, the processor 210 may compare the first identification information with the second identification information stored in the database 230 to detect the position of the movement means 100. [

The processor 210 controls the radiation pattern 211 of the reader antenna 221 in consideration of the moving speed of the moving means 100. The processor 210 can receive the moving speed information of the moving means 100 through the wired / wireless communication with the ECU (Electronic Control Unit) of the moving means 100 through the communication unit 240. [ The ECU may include a tachometer.

Wired / wireless communication can be realized by wired communication through a data cable and a communication network such as Wi-Fi, bluetooth, zigbee, Near Field Communication (NFC) , 3G, LTE, LTE-A).

The radiation pattern 211 means a pattern in which the reader antenna 221 radiates radio waves. The radiation pattern 211 may be modified into various forms under the control of the processor 210. For example, the radiation pattern 211 may be modified to have varying widths under the control of the processor 210.

The processor 210 may control the radiation pattern 211 such that the RFID reader 220 receives the minimum power required to receive the first identification information from the RFID tag 300. [ The determination of the minimum power required to receive the first identification information will be described in detail in Fig.

The processor 210 calculates a radiation pattern (e.g., a radial cross section) by considering at least one of the gain of the RFID tag 300 and the reader antenna 221, the radar cross section of the tag antenna, and the wavenumber of the operating frequency. 221 can be controlled.

The antenna gain means that the ratio of the power supplied to the reference antenna to give the same electric field in the same direction and the same distance and the electric power supplied to any antenna oriented to obtain the maximum value is expressed in decibels (dB). The RCS of the tag antenna means a plane area showing the reflection amount of the tag antenna when the electromagnetic wave emitted from the reader antenna 221 is reflected back to the tag antenna. Wave number means the wave number of the wavelength within the unit length as the inverse number of the wavelength.

The processor 210 can control the radiation pattern 211 so that the moving speed of the moving means 100 and the width of the radiation pattern 211 are proportional to each other. The processor 210 increases the width of the radiation pattern 211 when the moving speed of the moving means 100 increases and decreases the width of the radiation pattern 211 when the moving speed of the moving means 100 decreases .

The RFID reader 220 supplies power to the RFID tag 300 installed on the movement path 10 of the moving means 100 through the reader antenna 221. [ Also, the RFID reader 220 receives the first identification information from the RFID tag 300.

The reader antenna 221 may be a reconfigurable antenna. The reconfigurable antenna may have a reconfigurable structure. The reconfigurable antenna may change the structure according to the control command of the processor 210 to change the antenna characteristics including the radiation pattern 211. [

The reader antenna 221 may include an antenna array composed of a plurality of sub-antennas, and a plurality of sub-antennas having a plurality of feeds or radiation patterns 211 different from each other. The RFID reader 220 controls the plurality of sub-antennas having different feeds or radiation patterns 211 according to the control command of the processor 210 so that the radiation pattern 211 of the reader antenna 221, Can be controlled.

The database 230 may store the second identification information of the RFID tag 300 installed in the movement path 10 of the moving means 100 and the position corresponding to the second identification information. The database 230 may output the location information of the RFID tag 300 using the first identification information received from the processor 210. [ The structure of the database 230 is described in detail in FIG.

The communication unit 240 can perform wired / wireless communication between the position detecting device 200 and the mobile unit 100. [ Also, the communication unit 240 can perform wired / wireless communication between the position detection device 200 and the control server. Wired / wireless communication can be realized by a wired communication through a data cable and a communication network such as Wi-Fi, bluetooth, zigbee, Near Field Communication (NFC) , 3G, LTE, LTE-A).

The communication unit 240 can transmit the position of the detected moving means 100 to the control server. The control server can transmit the control information to the moving means 100 by using the position of the moving means 100. [

The power supply unit 250 supplies power required for the operation of the position detecting device 200. [ The processor 210 can control the radiation pattern 211 of the reader antenna 221 by adjusting the power supplied to the RFID reader 220 through the power supplier 250. [

3 is a view for explaining a process of determining a radiation pattern according to an embodiment.

3, the moving means 100, the moving path 10 of the moving means 100, the position detecting device 200 and the RFID tag 300 are shown.

3, R denotes a distance between the RFID reader 210 of the position detecting device 200 and the RFID tag 300, H denotes a vertical distance between the RFID reader 210 and the RFID tag 300, And 2D denotes the distance between the RFID tag 300 and the adjacent tag. In addition,? Denotes an angle between the RFID reader 210 and the RFID tag 300.

The power received by the RFID tag 300 from the RFID reader 210 can be expressed by Equation (1).

[Equation 1]

In the formula _1], P _{r, tg} is the received power of the RFID tag _(300), P _{t, rd} mean received power of the RFID reader 210. In addition, G _tg (?) _Denotes the antenna gain of the RFID tag 300, and G _RD (?) _Denotes the antenna gain of the RFID reader 210. In addition, P _{min , rd} denotes the minimum operating power of the RFID reader 210, σ denotes the RCS of the RFID tag 300, and λ denotes the number of waves of the operating frequency. In the following equations, the same parameters as the parameters of [Equation 1] have the same meaning as in Equation (1).

The power received by the RFID reader 210 from the RFID tag 300 can be expressed by Equation (2).

&Quot; (2) "

The RFID reader 210 is used to power the RFID reader 210, P _{r, rd} ≥P _{m in,} the condition to be the minimum operation of the received power over _rd received from the RFID tag 300 in Equation (2) (3). ≪ EMI ID = 3.0 >

&Quot; (3) "

If the called V = 4D / t _p, using the equation 3] and D = Rsinθ can be obtained [Equation 4]. Here, V is a moving speed of the moving means (100), t _p denotes the moving time of the moving means (100).

&Quot; (4) "

The processor 210 may determine the radiation pattern 211 using Equation (4). For example, the processor 210 may determine the minimum width of the radiation pattern 211 using? In Equation (4). An example of the radiation pattern 211 will be described in detail with reference to FIG.

4 is a graph showing the relationship between the width of the radiation pattern and the moving speed of the moving means according to one embodiment.

4, the minimum width of the radiation pattern 211 according to the speed of the moving means 100 is shown.

To _{P r, tg = 1W, G} tg (θ) = 1.2dBi, G RD (θ) = 6.0dBi, if P _min, of _{rd = 0.2mW, σ = 0.1,} 4 also by using the [equation 4] The graph shown can be obtained. 4, when the moving speed of the moving means 100 is 100 km / h, 200 km / h, 300 km / h, 400 km / h and 500 km / h, the minimum width 2θ of the radiation pattern 211 is 21.9 °, 44.6 DEG, 69.5 DEG, 98.8 DEG and 143.4 DEG. Thus, the processor 210 may control the radiation pattern 211 such that the radiation pattern 211 has a width greater than or equal to the calculated minimum width.

FIG. 5 is a diagram illustrating a change in radiation pattern according to the moving speed of the moving means according to an embodiment.

Referring to Fig. 5, an example of the radiation pattern 211 according to the moving speed of the moving means 100 is shown. In the graph shown in Fig. 5, the x-axis represents the traveling distance of the moving means 100, and the y-axis represents the speed of the moving means 100. [

As the moving speed of the moving means 100 increases, the width of the radiation pattern 211 may increase. For example, as shown in FIG. 5, the width of the radiation pattern 211 can be increased during a period in which the moving speed of the moving means 100 is increased. In the period during which the moving speed is slow, Can be reduced.

The processor 210 may control the radiation pattern 211 by placing a reference value. That is, when the moving speed of the moving means 100 exceeds the reference value, the width of the radiation pattern 211 can be increased. For example, when the moving speed of the moving means 100 exceeds 100 km / h, exceeds 200 km / h, and exceeds 300 km, the width of the radiation pattern 211 is 25 ° and 45 °, ° and 70 °, respectively.

The reader antenna 211 may include a plurality of antennas having a width of a different radiation pattern 211 and the processor 210 may select the antenna corresponding to the current traveling speed among the plurality of antennas, Can be controlled.

6 is a diagram illustrating the structure of a database according to an embodiment.

Referring to FIG. 6, the database 230 receives the first identification information, determines second identification information corresponding to the first identification information, and outputs the position of the first identification information. For example, when the first identification information is A11, the database 230 may search for A11 corresponding to the first identification information by comparing the first identification information with the second identification information. Further, the database 230 may output the position Z corresponding to A11.

Accordingly, the database 230 may transmit the position of the RFID tag 300 having the first identification information to the processor 210 using the first identification information received from the processor 210. [

7 is a flowchart illustrating a method of controlling an RFID interrogator according to an embodiment of the present invention.

Referring to FIG. 7, in step 710, the position detection device 200 determines a radiation pattern 211 of the reader antenna 211. FIG. The position detecting apparatus 200 determines whether or not the movement speed of the moving means 100 and the RFID reader 300 are required to receive the identification information from the RFID tag 300 through the reader antenna 221 provided in the RFID reader 220 The radiation pattern 211 of the reader antenna 211 can be determined in consideration of the minimum power.

The position detecting device 200 can receive the moving speed information of the moving means 100 through wired / wireless communication with the ECU (Electronic Control Unit) of the moving means 100. [ The ECU may include a tachometer. In addition, wired / wireless communication can be realized by a wired communication through a data cable and a wired communication through a wired communication network such as Wi-Fi, bluetooth, zigbee, Near Field Communication (NFC) For example, 3G, LTE, LTE-A).

Step 710 may include determining the radiation pattern 211 considering at least one of the antenna gain of the RFID tag, the antenna gain of the RFID reader, the radar cross-section of the tag antenna, and the number of waves of the operating frequency. The antenna gain means that the ratio of the power supplied to the reference antenna to give the same electric field in the same direction and the same distance and the electric power supplied to any antenna oriented to obtain the maximum value is expressed in decibels (dB). The RCS of the tag antenna means a plane area showing the reflection amount of the tag antenna when the electromagnetic wave emitted from the reader antenna 221 is reflected back to the tag antenna. Wave number means the wave number of the wavelength within the unit length as the inverse number of the wavelength.

Step 710 may include determining the radiation pattern 211 of the reader antenna 220 so that the moving speed of the moving means 100 and the width of the radiation pattern 211 are proportional. The position detecting device 200 can reduce the width of the radiation pattern 211 when the moving means 100 travels at a low speed.

In step 720, the position detecting device 200 controls the radiation pattern 211. [ The reader antenna 221 may be a reconfigurable antenna. The reconfigurable antenna may have a reconfigurable structure. The reconfigurable antenna may change the structure according to the control command of the processor 210 to change the antenna characteristics including the radiation pattern 211. [

In operation 720, the position detection apparatus 200 controls the radiation pattern 211 using an antenna array including a plurality of sub-antennas, a single antenna including a plurality of feeds, or a plurality of antennas having different radiation patterns .

The position detecting device 200 can transmit power exceeding a threshold value for transmitting the identification information by the RFID tag 300 through the control of the RFID reader 220. [ Therefore, the position detecting device 200 can sense the RFID tag 300 without missing, and can improve the power efficiency by adjusting the radiation pattern 211 so that no surplus power is generated in the RFID tag 300. [

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI > or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (15)

An RFID reader having an antenna and receiving first identification information from an RFID tag installed on a moving path of the moving means through the antenna; And
A processor for detecting the position of the moving means using the first identification information,
Lt; / RTI >
The processor determines a radiation pattern of the antenna in consideration of the moving speed of the moving means and the minimum power required for the RFID reader to receive identification information from the RFID tag through the antenna provided in the RFID reader, Determining a radiation pattern of the antenna by considering at least one of an antenna gain of the tag, an antenna gain of the RFID reader, a radar cross section of the RFID tag antenna, and a wavelength number of the operating frequency,
And the width of the radiation pattern of the antenna is calculated by using the following equation (4).
&Quot; (4) "

[θ: the radiation pattern of the antenna width, V: travel time of the mobile _unit, P _{t, rd::} moving speed of the moving means, t _p reception of RFID power, G _tg: antenna gain of the RFID tag, G _RD: RFID ?: RCS of RFID tag,?: Wavelength number of operation frequency _{, Pmin, rd} : minimum operating reception power of RFID reader] delete delete The method according to claim 1,
The processor comprising:
And controlling the radiation pattern so that a moving speed of the moving means and a width of the radiation pattern are proportional to each other,
Position detecting device. The method according to claim 1,
The antenna includes:
An antenna array comprising a plurality of sub-antennas,
The processor comprising:
And controlling the radiation pattern using the antenna array,
Position detecting device. The method according to claim 1,
The antenna includes:
Comprising a plurality of feeds,
The processor comprising:
And controlling the radiation pattern using the plurality of feeds,
Position detecting device. The method according to claim 1,
The processor comprising:
And controlling the radiation pattern by adjusting a power supplied to the RFID reader,
Position detecting device. The method according to claim 1,
The antenna includes:
A plurality of sub-antennas having different radiation patterns,
The processor comprising:
And controlling the radiation pattern using the plurality of antennas,
Position detecting device. The method according to claim 1,
The processor comprising:
And comparing the first identification information with second identification information stored in a database to detect the position of the movement means.
Position detecting device. A method of controlling an RFID reader for detecting a position of a moving means,
Determines the radiation pattern of the antenna by considering the moving speed of the moving means and the minimum power required for the RFID reader to receive the identification information from the RFID tag through the antenna provided in the RFID reader, Wherein the radiation pattern of the antenna is determined by considering at least one of a gain, an antenna gain of the RFID reader, a radar cross-sectional area of the RFID tag antenna, and a wavelength number of an operation frequency, 4]; And
And controlling the radiation pattern of the antenna based on the calculated width of the radiation pattern of the antenna.
&Quot; (4) "

[θ: the radiation pattern of the antenna width, V: travel time of the mobile _unit, P _{t, rd::} moving speed of the moving means, t _p reception of RFID power, G _tg: antenna gain of the RFID tag, G _RD: RFID ?: RCS of RFID tag,?: Wavelength number of operation frequency _{, Pmin, rd} : minimum operating reception power of RFID reader] delete 11. The method of claim 10,
The step of determining the radiation pattern of the antenna in consideration of the moving speed of the moving means and the minimum power required for the RFID reader to receive the identification information from the RFID tag through the antenna provided in the RFID reader,
And determining a radiation pattern of the antenna such that a moving speed of the moving means is proportional to a width of the radiation pattern.
Control method of RFID reader. 11. The method of claim 10,
Wherein controlling the radiation pattern of the antenna based on the determined radiation pattern comprises:
And controlling an antenna array comprised of a plurality of sub-antennas included in the antenna.
Control method of RFID reader. 11. The method of claim 10,
Wherein controlling the radiation pattern of the antenna based on the determined radiation pattern comprises:
And controlling a plurality of feeds included in the RFID reader.
Control method of RFID reader. 11. The method of claim 10,
Wherein controlling the radiation pattern of the antenna based on the determined radiation pattern comprises:
And adjusting the supply power supplied to the RFID reader.
Control method of RFID reader.

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