JP2003028954A - System and method for measurement of distance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily measure distance using a simple constitution. SOLUTION: The distance-measuring system or the distance measuring method is provided with an ID detector 1, which creates a tag detection signal so as to detect a reception confirmation signal, an antenna 11 which transmits the tag detection signal for receiving the reception confirmation signal, and an ID tag 2 which receives the tag detection signal for transmitting the reception confirmation signal. The ID detector 1 changes the strength of the tag detection signal to be transmitted from the antenna 11, and it detects the distance between the ID tag 2 and the antenna 11, on the basis of the detection strength of the reception confirmation signal received by the antenna 11 or on the basis of whether or not the confirmation signal is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to distance measurement using an ID tag.

[0002]

2. Description of the Related Art Conventionally, distances have been measured manually or by using complicated equipment. In addition, railroad track floor depressions, slope failures and road surface depressions are visually confirmed.

[0003]

<A> The present invention is to easily measure a distance with a simple configuration. <B> Further, the present invention is to easily detect a detection position of depression, collapse, or collapse. <C> Further, the present invention is to easily detect depression of the rail track floor. <D> Further, the present invention is to easily detect slope collapse.

[0004]

The present invention is directed to an ID detection device for producing a tag detection signal and detecting a reception confirmation signal, an antenna for transmitting a tag detection signal and receiving the reception confirmation signal, and a tag detection signal. I to send a confirmation signal
The D detection device includes a D tag, and the ID detection device transmits the tag detection signal from the antenna while changing the intensity, and measures the distance between the ID tag and the antenna according to the detection intensity of the reception confirmation signal received by the antenna or the presence or absence of the detection. Distance measuring system, or
In the distance measuring system, the ID tag is arranged at a detection position of depression, collapse, or collapse, and the antenna is arranged apart from the ID tag.
Alternatively, in the distance measurement system, an ID tag is arranged on a rail track floor, an antenna is used as a cable, and the antenna is arranged apart from the ID tag along the rail track, or the distance measurement system, or the distance. In the measuring system, the ID tag is arranged on the slope, the antenna is used as a cable, and the antenna is separated from the ID tag and arranged along the slope.
The D tags are arranged apart from each other, the tag detection signal is transmitted from the antenna with varying intensity, the tag detection signal is received by the ID tag and the reception confirmation signal is transmitted, and the detection intensity of the reception confirmation signal received by the antenna or It is a distance measuring method that measures the distance between the ID tag and the antenna depending on whether or not there is detection.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

<A> Distance Measuring System As shown in FIG. 1, the distance measuring system includes at least an ID detecting device 1, an antenna 11 and an ID tag 2.
Is provided, and the distance between the antenna 11 and the ID tag 2 is measured. The ID detection device 1 and the ID tag 2 used in this system are generally used. For example, when the ID tag 2 passes near the antenna 11, it is used for confirmation of passage and the like. It has already been used for logistics management and human communication management.

<B> ID Tag The ID tag 2 is a device for transmitting a reception confirmation signal when receiving a tag detection signal transmitted from the antenna 11.
The ID tag 2 cannot respond when the electric field strength 12 of the tag detection signal becomes weak. Therefore, when the distance between the antenna 11 and the ID tag 2 becomes long and the antennas are separated from each other and the electric field strength 12 of the tag detection signal transmitted from the antenna becomes weak near the ID tag, the ID tag 2 cannot respond.

A unique identification number can be written in each ID tag 2. Therefore, the reception confirmation signal can be transmitted with a unique identification number.

The ID tag 2 includes a battery built-in type and a battery-less type that self-generates power when receiving a tag detection signal.

<C> Antenna The antenna 11 transmits a tag detection signal and receives a reception confirmation signal. When a cable is used, the antenna 11 can transmit a tag detection signal having a certain strength or more over a long distance, can receive a reception confirmation signal from the ID tag 2, and can freely change its length and shape. Therefore, the transmission area of the tag detection signal can be specified.

<D> ID Detection Device The ID detection device 1 produces a tag detection signal, and the antenna 1
The reception confirmation signal transmitted from 1 and received by the antenna 11 is detected. The ID detection device 1 can adjust the emission intensity of the tag detection signal, and can repeat the scanning of the emission intensity of the tag detection signal, for example.
Further, the ID detection device 1 can detect the strength of the reception confirmation signal received by the antenna 11 and can detect the presence or absence of reception of the reception confirmation signal.

A method of measuring the distance between the ID tag and the antenna will be described below.

<A> Setting of Distance Measuring System The ID detecting device 1 is connected to the antenna 11 of the cable. A plurality of ID tags 2 are arranged around the antenna 11. Each ID tag 2 includes, for example, ID, ID, I
It has a unique identification number like D. Each ID tag 2 is arranged with the reception distances R1, R2, R3 from the antenna 11.

<B> Transmission of Tag Detection Signal and Reception of Reception Confirmation Signal The ID detection device 1 produces a tag detection signal, gradually increases its intensity, and transmits it from the antenna 11. In this way, the scanning for gradually increasing the strength is repeated. Since the electric field strength of the tag detection signal gradually increases around the antenna 11, the ID tag 2 at the position where the electric field strength becomes strong receives the tag detection signal and transmits a reception confirmation signal. The reception confirmation signal is received by the antenna 11 and detected by the ID detection device 1. Since the reception confirmation signal includes the identification number unique to the ID tag, it is possible to identify which ID tag the reception confirmation signal is from from the reception confirmation signal. If the distance between the antenna 11 and the ID tag 2 is too large, the ID
The tag 2 cannot transmit the reception confirmation signal.

<C> Measurement of distance between antenna and ID tag Since the electric field strength of the tag detection signal depends on the distance from the antenna 11, the distance between the antenna 11 and the ID tag 2 and the tag detection of the ID tag 2 are detected in advance. The distance between the antenna 11 and the ID tag 2 can be obtained by obtaining the relationship between the signal reception limit (and the transmission limit of the reception confirmation signal) and the electric field strength (transmission output of the tag detection signal). That is, ID tag 2
By knowing the electric field strength of the tag detection signal when the reception confirmation signal transmitted from
And the distance between the ID tag 2 can be obtained. Since such distance measurement is based on the electric field strength of the output, the accuracy is about several cm, and the measurement range can be within several meters near the antenna.

Conversely, when the intensity of the tag detection signal (transmission output of the tag detection signal) is transmitted from the antenna so as to be gradually weakened, the electric field intensity of the tag detection signal at the time when the reception of the reception confirmation signal is interrupted is known. By doing so, the distance between the antenna and the ID tag can be similarly obtained.

Alternatively, if the relationship between the electric field strength of the tag detection signal, the strength of the received reception confirmation signal, and the distance between the antenna and the ID tag is obtained in advance, the electric field strength of the tag detection signal and the received reception By measuring the strength of the confirmation signal, the distance between the antenna and the ID tag can be obtained.

An application example will be described below.

<B> Railroad Track Floor Measurement In the railroad track floor distance measuring system, a large number of ID tags 2 are installed on the railroad track floor, cable antennas 11 are arranged along the track, and the antenna 11 has an ID detection device. Attach 1. Each ID tag 2 has an individual identification number.

The ID detecting device 1 repeats the scanning of the tag detection signal and detects the reception of the reception confirmation signal from each ID tag 2 to obtain the positional deviation of each ID tag 2 or the undetectable information. it can. If the reception confirmation signal from a certain ID tag 2 cannot be detected,
It is possible to automatically detect in real time that the railway track floor at the place where the ID tag 2 is arranged may have collapsed.

<B> Slope measurement The slope distance measuring system is installed in the construction management area of the slope.
A large number of D tags 2 are installed, the antenna 11 of the cable is arranged in the construction management area on the slope, and the ID detection device 1 is attached to the antenna 11. By arranging the system in this way, it is possible to automatically detect the collapse position of the slope in real time, similarly to the measurement of the railway track floor.

<C> Road surface measurement accompanying construction work The road surface distance measurement system has IDs around the road surface construction area.
A large number of tags 2 are installed, a cable antenna 11 is arranged around the construction area, and the ID detection device 1 is attached to the antenna 11. By arranging the system in this way, it is possible to automatically detect the depression position of the road surface due to the construction work in real time, similarly to the measurement of the railway track floor.

<D> Fall / collapse / fall detection / prediction With the same configuration as the distance measurement system, it can be used as a detection / prediction system. Install a distance measurement system at the location where you want to detect or predict the fall, collapse or collapse of the ground. By constantly measuring the distance between the ID tag 2 and the antenna 11 by the ID detection device 1,
The displacement (misalignment) of the installation position of the tag 2 can be detected. By tracking the time course of this displacement, it is possible to predict or detect the fall, collapse, or fall of the ground or the like.

[0024]

The present invention has the following effects. <B> According to the present invention, the distance can be easily measured with a simple configuration. <B> In addition, the detection positions of depression, collapse, and collapse can be easily detected. <C> Further, according to the present invention, the depression of the railway track floor can be easily detected. <D> Further, the present invention can easily detect slope collapse.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a distance measuring system.

[Fig.2] Illustration of railroad track floor depression detection

FIG. 3 is an explanatory diagram of slope failure detection.

[Explanation of symbols]

1 ... ID detection device 11 ... Antenna 12 ... Electric field strength 2 ... ID tag

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seisuke Kato             2-2-2 Yoyogi, Shibuya-ku, Tokyo Tohnichi             Inside the passenger railway (72) Inventor Takahiro Kondo             1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei             Construction Co., Ltd. (72) Inventor Hiromichi Miyazaki             1-25-1 Nishi-Shinjuku, Shinjuku-ku, Tokyo Taisei             Construction Co., Ltd. F-term (reference) 5J070 AC02 AD02 AF01 BC03

Claims (5)

[Claims] 1. An ID detection device for producing a tag detection signal and detecting a reception confirmation signal, an antenna for transmitting a tag detection signal and receiving a reception confirmation signal, and a tag detection signal for receiving a reception confirmation signal. The ID detection device is provided with an ID tag to be transmitted, and the ID detection device transmits the tag detection signal from the antenna by changing the intensity and measures the distance between the ID tag and the antenna by the detection intensity of the reception confirmation signal received by the antenna or the presence or absence of the detection A distance measuring system. 2. The distance measuring system according to claim 1, wherein the ID tag is arranged at a detection position of depression, collapse or collapse, and the antenna is arranged apart from the ID tag. . 3. The distance measuring system according to claim 1, wherein the ID tag is arranged on the rail track floor, the antenna is a cable, and the ID tag is arranged apart from the ID tag along the rail track. Distance measuring system. 4. The distance measuring system according to claim 1, wherein the ID tag is arranged on a slope, the antenna is a cable, and the antenna is arranged apart from the ID tag along the slope. Measuring system. 5. An antenna and an ID tag are arranged apart from each other, a tag detection signal is transmitted from the antenna with varying strength, a tag detection signal is received by the ID tag, a reception confirmation signal is transmitted, and the signal is received by the antenna. A distance measuring method in which the distance between the ID tag and the antenna is measured according to the detection intensity of the reception confirmation signal or the presence or absence of detection.