JP2000307466A - Device and method for identifying mobile body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile body identifying device which reduces the probability that an interrogator and a transponder become hard to receive a signal and which makes the interrogator small-sized. SOLUTION: The interrogator sends an interrogation information signal by connecting a transmission part 14 to one of two feed points of a two-point feed microstrip antenna for transmission provided at the position where lines extended from two feed points to the center of a radiation element cross each other at right angles alternately by a transmission changeover switch part 15. The interrogator receives a transponder information signal by connecting a reception part 19 to one of two feed points of a two-point feed microstrip antenna for reception provided at the position where lines extended from two feed points to the center of the radiation element cross each other at right angles alternately by a reception changeover switch part 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving object identifying apparatus, and more particularly, to a moving object identifying apparatus which transmits a signal from an interrogator and receives a signal returned from the moving object by the interrogator to identify the moving object. It concerns the device.

[0002]

2. Description of the Related Art A transponder (also referred to as a tag) for receiving a question information signal and returning a response information signal is attached to an article (hereinafter, referred to as a moving body) such as a human, an animal, or a car. Send (transmit) a question information signal, and
The moving object identification device that identifies the moving object by receiving the response information signal returned from the transponder has the advantages of being able to identify the moving object in a non-contact and distant position. It has been put to practical use for security and process management.

When the above-mentioned moving object identification device is used indoors, the question information signal and the response information signal travel while reflecting off obstacles such as walls, so that the probability that their polarization planes change becomes extremely high. Further, when the position or the mounting direction of the transponder attached to the moving body changes, the polarization plane of the receiving antenna of the transponder may shift or the polarization plane of the response information signal may change. Due to the change in the polarization plane of the interrogation information signal and the response information signal and the deviation of the polarization plane of the receiving antenna of the transponder, it becomes difficult for the transponder to receive the interrogation information signal, and it becomes difficult for the interrogator to receive the response information signal. May be. For this reason, the interrogator of the mobile object identification device
The transmitting antenna and the receiving antenna are configured to transmit and receive signals of two polarizations, a horizontal polarization and a vertical polarization, using a horizontal polarization antenna and a vertical polarization antenna, respectively. Is common.

FIG. 3 shows a block diagram of a general mobile object identification device. The mobile object identification device 30 is a data processing device 1
1, an interrogator 12 and a responder 13. The interrogator 12 converts the interrogation information input from the data processing device 13 into a specific interrogation information signal at the transmission unit 14, and alternately temporally alternately operates the vertically polarized transmission antenna 3 by the transmission changeover switch unit 35.
1 and the horizontally polarized wave transmitting antenna 32, thereby alternately transmitting the horizontally polarized question information signal and the vertically polarized question information signal. Then, the modulating unit 2 is
1 is received by the vertical polarization receiving antenna 33 and the horizontal polarization receiving antenna 34 of the interrogator, so that the horizontal polarization response information signal and the vertical polarization response information signal are received. To receive. The response information signals received by the two receiving antennas are transmitted to the reception changeover switch unit 1.
The data is alternately sent to the receiving unit 19 in time, converted into response information by the receiving unit 19, and then output to the data processing device 11. Then, the data processing device 11 identifies the moving object based on the output response information.

[0005] In the above-mentioned mobile object identification device, the interrogator alternately transmits interrogation information signals of two polarization planes and receives response information signals on the two polarization planes. The probability that the polarization plane of the interrogation information signal changes to make it difficult for the transponder to receive or the polarization plane of the response information signal changes to make it difficult for the interrogator to receive the response signal is reduced.

[0006]

As described above, the moving object identification apparatus is often used indoors, and the interrogator is usually installed at a passage through which the moving object passes. Therefore, it is desirable that the interrogator be small in size so as not to obstruct the passage of the moving object. However, since the interrogator requires at least two transmitting and receiving antennas for each of the reasons described above, there is a problem that it is difficult to reduce the size of the interrogator.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the probability that an interrogator and a transponder will have difficulty receiving a signal, and to reduce the size of an interrogator. An object of the present invention is to provide a body identification device.

[0008]

The inventor of the present invention has made intensive studies to solve the above-mentioned problems. As a result, two feeding points used as means for generating circularly polarized waves are directed toward the center of the radiating element. By alternately connecting one of the two feeding points of the two-point feeding microstrip antenna provided at a position where the extended line is orthogonal to the transmitting part and the transmitting part, the signal is alternately tilted by 90 degrees in the signal polarization plane. (Vertically polarized and horizontally polarized signals), and by alternately connecting one of the two feed points and the receiver, the polarization plane of the antenna is alternately turned 90 degrees. I noticed that I could receive signals (vertically and horizontally polarized) while tilting.

Accordingly, the present invention comprises a data processing device, an interrogator and a transponder electrically connected to the data processing device, the data processing device processes the query information and the response information, and the interrogator performs the data processing. The question information input from the device is converted to a question information signal by the transmitter and transmitted from the transmitting antenna, the response information signal from the transponder is received by the receiving antenna, and converted to the response information by the receiver to process the data. A mobile identification device that outputs a response information signal corresponding to the interrogation information signal to the transmitting unit, wherein the transmitting antenna is
A transmitting two-point feeding microstrip antenna in which two feeding points are provided at positions where lines extending toward the center of the radiating element are orthogonal to each other, and the interrogator has a transmitting unit and a transmitting two-point feeding microstrip antenna. A transmission changeover switch unit for alternately connecting one of the two feeding points is provided, and the receiving antenna is arranged at a position where a line extending from the two feeding points toward the center of the radiating element is orthogonal. The receiving two-point feeding microstrip antenna is provided, and the interrogator has a receiving changeover switch unit that alternately connects one of the two feeding points of the receiving two-point feeding microstrip antenna and the receiving unit. The moving object identification device is provided.

Further, according to the present invention, by using the above-mentioned moving object identification device, question information is inputted from a data processing device to an interrogator, and the question information is converted into a question information signal by a transmission section, and the two points for transmission are transmitted. By alternately connecting one of the two feeding points of the feeding microstrip antenna and the transmitting unit using the transmitting changeover switch unit, the polarization information plane alternately transmits the question information signal inclined by 90 degrees, and The response information signal returned from the transponder, by alternately connecting the receiving unit of the interrogator and one of the two feeding points of the receiving two-point feeding microstrip antenna using the reception switching unit, The receiving antenna receives the signal while alternately tilting the polarization plane by 90 degrees, converts the information into response information in the receiving unit, outputs the information to the data processing unit, and outputs the information to the data processing unit. Of response information signals received by the plane of polarization of, respectively, there is also a method of identifying a moving body performs an identification process by selecting the higher reception sensitivity.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an example of a moving object identification device according to the present invention. Mobile object identification device 10 of the present invention
Is a transponder 11, an interrogator 12, and a data processor 13
Consists of The interrogator 12 and the data processing device 13 may be integrally combined. The interrogator 12 includes a transmitting unit 14,
The transmission switch unit 15 includes a transmission two-point feeding microstrip antenna 16, a reception two-point feeding microstrip antenna 17, a reception switch 18, and a reception unit 19. The transponder 13 includes a linearly polarized wave receiving antenna 20, a modulator 21, and a linearly polarized wave returning antenna 22.

The moving object identification apparatus according to the present invention includes an interrogator 12
However, transmission switching is performed between one of the two feeding points of the two-point feeding microstrip antenna for transmission provided at a position where a line where the two feeding points extend toward the center of the radiating element is orthogonal to the transmitting unit 14. The interrogation information signals are transmitted alternately by the switch unit 15 and the two feeding points of the receiving two-point feeding microstrip antenna are provided at positions where lines extending toward the center of the radiating element are orthogonal to each other. One of the feeding points and the receiving unit 19 are alternately connected by the receiving changeover switch unit 18 to receive a response information signal.

FIG. 2 is a front view of a two-point feeding microstrip antenna. As shown in the figure, the two-point feeding microstrip antenna 23 has a central portion 26 of the radiating element.
Two feed points 2 at positions where the line extending toward
4a and 24b, for example, a signal having a certain polarization plane by exciting the feed point 24a [first
(# 1) mode] 25a is generated, and by exciting the feed point 24b, a signal [second (# 2) mode] 25b whose polarization plane is inclined by 90 degrees with respect to the signal 25a is generated. The degree of isolation between the first mode and the second mode is good, and there is no practical problem even if the first mode and the second mode are generated alternately. Therefore, 90
Signals with two polarization planes inclined at an angle can be obtained by one two-point feeding microstrip antenna. The radiating element of the two-point feeding microstrip antenna is not limited to a circle, and its shape is not particularly limited as long as it is symmetric with at least one straight line passing through the center, and as a specific example, a polygon such as a square It may be. The two-point feeding microstrip antenna is well known as described in, for example, "Latest Planar Antenna Technology" supervision: Manabu Hishi, issuance: General Technology Center Co., Ltd., pp. 75-76.

There is no particular limitation on the data processing device 11 used in the mobile unit identification device of the present invention. For example, a commercially available computer or the like which records a program for processing question information and response information can be used.

There is no particular limitation on the transponder used in the moving object identification device of the present invention, and a conventionally used transponder can be used. Linearly polarized wave receiving antenna 20,
It is preferable to use a microstrip antenna as the linearly polarized wave returning antenna 22.

Next, a method for identifying a moving object using the moving object identifying apparatus of the present invention will be described with reference to FIG. The method for identifying a moving object includes four elements: transmission of an interrogator interrogation information signal, return of a transponder response information signal, reception of an interrogator response information signal, and data processing.

(Transmission of Interrogator Question Information Signal) Interrogator 1
2 converts the question information input from the data processing device 11 to the transmitter of the interrogator into a question information signal by the transmitter 14 of the interrogator, and converts the two signals of the two-point feeding microstrip antenna 16 for transmission of the interrogator. By alternately connecting one of the feeding points and the transmission unit 14 using the transmission changeover switch unit 15, the inquiry information signals of two polarization planes whose polarization planes are inclined by 90 degrees are transmitted alternately.

(Return of Response Information Signal of Transponder) Transponder 1
3 transmits a response information signal corresponding to the interrogation information signal received by the linearly polarized wave receiving antenna 20 to the linearly polarized wave transmitting antenna 22;
Will be returned from The return of the response signal information is performed by modulating the interrogation information signal by the modulator 21. The modulation method is not particularly limited, and a known method such as amplitude modulation, frequency modulation, and phase modulation can be adopted.

(Reception of Response Information Signal of Interrogator) Interrogator 1
2 is to alternately connect one of the two feeding points of the receiving two-point feeding microstrip antenna to the receiving unit 19 of the interrogator by using the receiving changeover switch unit 19, so that the receiving antenna is polarized. The wavefront is received while being alternately tilted by 90 degrees, converted into response information by the receiving unit of the interrogator, and output to the data processing unit.

(Data processing) The data processing device 11 selects the one of the response information signals received on the two polarization planes of the receiving antenna with higher reception sensitivity to identify the mobile object,
Perform that process.

[0021]

According to the mobile identification apparatus of the present invention, the number of transmitting and receiving antennas of the interrogator is reduced to half the number of transmitting and receiving antennas of the interrogator of the conventional mobile identification apparatus. However, the moving object can be identified within the same range as the conventional moving object identification device. Therefore, the moving object identification device of the present invention can reduce the size of the interrogator and the manufacturing cost is low. Also, since the size of the interrogator can be made smaller than conventional interrogators,
In the related art, the mobile object identification device can be installed in a place where the arrangement of the mobile object identification device is difficult.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a moving object identification device according to the present invention.

FIG. 2 is a front view of a two-point feeding microstrip antenna.

FIG. 3 is a block diagram illustrating a configuration of a general moving object identification device.

[Explanation of symbols]

 Reference Signs List 10, 30 Mobile object identification device 11 Transponder 12 Interrogator 13 Data processing device 14 Transmitting unit 15 Transmission switching switch unit 16 Two-point feeding microstrip antenna for transmission 17 Two-point feeding microstrip antenna for reception 18 Reception switching switch unit 19 Reception Unit 20 linearly polarized wave receiving antenna 21 modulating unit 22 linearly polarized wave returning antenna 23 circularly polarized microstrip antenna 24a, 24b feeding point 25a, 25b signal 26 central part 31 vertical polarized wave transmitting antenna 32 horizontal polarized wave transmitting antenna 33 vertical polarized wave Wave receiving antenna 34 Horizontally polarized wave receiving antenna

Continuation of front page (72) Inventor Hironobu Takahashi 2-10-19, Ueda-shi, Nagano Pref.

Claims (2)

[Claims] 1. A data processing device, comprising an interrogator and a transponder electrically connected to the data processing device, wherein the data processing device performs processing of question information and response information, and the interrogator is inputted from the data processing device. The question information is converted into a question information signal by the transmitting unit and transmitted from the transmitting antenna, the response information signal from the transponder is received by the receiving antenna, converted to the response information by the receiving unit, and output to the data processing unit. A mobile identification device in which a transponder returns a response information signal corresponding to a query information signal, wherein the transmitting antenna is located at a position where a line having two feed points extending toward the center of the radiating element is orthogonal. A two-point feeding microstrip antenna for transmission provided, wherein the interrogator alternately connects the transmitting part and one of the two feeding points of the two-point feeding microstrip antenna for transmission. A changeover switch unit is provided, and
The receiving antenna is a receiving two-point feeding microstrip antenna in which two feeding points are provided at positions where lines extending toward the center of the radiating element are orthogonal to each other. A mobile object identification device, comprising: a reception changeover switch unit that alternately connects one of two feeding points of a strip antenna and a reception unit. 2. Using the mobile object identification device according to claim 1, inputting question information from a data processing device to an interrogator, converting the question information into a question information signal at a transmitting unit, and transmitting two points. By alternately connecting one of the two feeding points of the feeding microstrip antenna and the transmitting unit using the transmitting changeover switch unit, the polarization information plane alternately transmits the question information signal inclined by 90 degrees, and The response information signal returned from the transponder, by alternately connecting the receiving unit of the interrogator and one of the two feeding points of the receiving two-point feeding microstrip antenna using the reception switching unit, Receiving data while tilting the plane of polarization of the receiving antenna alternately by 90 degrees, converting it into response information in a receiving unit, outputting the response information to the data processing unit, and using a data processing device, each of the receiving antennas A method for identifying a moving object, in which the response information signal received on the polarization plane is selected to select the one with the higher reception sensitivity and performs the identification processing.