JP3686469B2

JP3686469B2 - Entrance / exit monitoring device

Info

Publication number: JP3686469B2
Application number: JP03428496A
Authority: JP
Inventors: 義則小澤
Original assignee: Japan Radio Co Ltd
Current assignee: Japan Radio Co Ltd
Priority date: 1996-01-30
Filing date: 1996-01-30
Publication date: 2005-08-24
Anticipated expiration: 2016-01-30
Also published as: JPH09212759A

Description

【０００１】
【発明の属する技術分野】
この発明は、電波を利用して検出区画内に入出する検出対象を監視する入出監視装置に関する。
【０００２】
【従来の技術】
検出区画内に入出する検出対象を監視する入出監視装置には種々の装置が存在するが、例えば図１に示すような装置がある。
図１は、本発明の実施形態を説明するための図でもあるが、データ処理装置４０の構成を除いて従来の装置と同様であるので、図１を用いて従来のこの種の入出監視装置を説明する。
図において、１は検出区画、２はその出入口、１０は検出対象（移動体）、２０は検出対象１０に装着された発信機、３０ａは検出区画１内の中央付近に設置された受信機、３０ｂは同じく出入口２付近に設置された受信機、４０はデータ処理装置、５０は表示器である。
なお、説明を解り易くするために各部の縮尺は必ずしも正確ではない。
【０００３】
また、検出対象１０は移動して出入口２から検出区画１を出入する移動体であり、図１では一つだけを図示しているが、一般的には検出対象１０は複数存在し、それぞれの検出対象１０にそれぞれ異なったＩＤを発信する発信機２０が装着されている。
また、発信機２０と受信機３０とは無線回線で接続されており、受信機３０ａと３０ｂおよびデータ処理装置４０と表示器５０とは、データ信号線で接続されている。
各受信機３０は、発信機２０からの無線信号を受信すると、受信電界強度，受信後にデータ処理装置４０にデータを送信するまでの経過時間（以下、単に経過時間と呼ぶ），当該発信機２０のＩＤ番号を検出し、これらに自己の受信機の番号を付したデータをデータ処理装置４０へ信号として送信する。
【０００４】
図３は、従来の入出監視装置に用いられる処理装置４０の構成を示すブロック図であり、図において、４０１はモデム、４０２は時刻演算回路、４０３は電界強度比較回路、４０４は表示制御回路である。
モデム４０１では送られてきた信号を復調し、受信機３０の番号，発信機２０のＩＤ番号，経過時間，受信電界強度をデータとして出力し、時刻演算回路４０２で受信機３０での受信時刻を算出する。
また電界強度比較回路４０３では受信電界強度が所定レベル以上ある場合に電波を受信したとする判定、発信機２０からの電波が同時に２台の受信機３０で受信された場合に受信電界強度の強い方の受信機の特定、さらに受信電界強度が同じ場合には出入口２付近に設置した受信機３０ｂから受信したとする特定を行う。
そしてこれら判定，特定されたデータは、表示制御回路４０４へ送られ、表示制御回路４０４が動作して表示器５０に検出対象１０の出入り状況が表示される。
【０００５】
次に従来の出入監視装置で行う出入りの判定について説明する。表示器５０の表示において検出区画１内に検出対象１０が存在しないと判定された状態以降に、受信機３０ａで発信機２０からの所定電界強度以上の電波を受信した場合、検出区画１内に検出対象１０が入ったと判断し、表示器５０にその旨の表示が行われる。
また、表示器５０に検出対象１０が検出区画１内に存在する旨の表示がなされている状態以降に、発信機２０からの電波の受信電界強度が、受信機３０ａでの受信電界強度より、受信機３０ｂでの受信電界強度が強くなった場合、検出対象１０が検出区画１内から出たと判断し、表示器５０にその旨の表示が行われる。すなわち、発信機２０からの電波が検出区画１中央付近に設置した受信機３０ａで受信される（あるいはその受信電界強度が受信機３０ａでより強く受信される）場合には、検出対象１０が当然検出区画１内に存在すると判断し、また出入口２付近に設置した受信機３０ｂで受信される（あるいはその受信電界強度が受信機３０ｂでより強く受信される）場合には、検出対象１０が当然出入口２付近に存在し、このことは検出対象１０が検出区画１内から出ることを意味するので、検出対象１０が検出区画１内から出たと見做して、表示器５０にその旨が表示される。
【０００６】
【発明が解決しようとする課題】
従来の入出監視装置は以上のように構成され動作するので、検出対象１０が受信機３０ａと受信機３０ｂの中間付近に位置する場合、誤った判断がなされてしまう場合がある。
すなわち、検出対象１０が受信機３０ａと受信機３０ｂの中間付近に位置する場合、受信機３０ａでの受信電界強度と受信機３０ｂでの受信電界強度とがほぼ等しくなるが、このような場合電波の受信環境の変化等により受信機３０ａの方が一時的に強くなったり、受信機３０ｂの方が一時的に強くなったりするふらつき状態が発生する。
従来の装置では実際には検出対象１０が中間付近に静止している場合でもこのようなふらつきをそのまま検出してしまうため、出入りが繰り返されたと誤判断され、表示器５０には出入りが繰り返される旨が表示さてしまう。
【０００７】
本発明はかかる問題点を解決するためになされたものであり、簡単な構成で正確な出入りの検出ができる入出監視装置を提供することを目的としている。
【０００８】
【課題を解決するための手段】
本発明に係わる入出監視装置は、
少なくとも検出区画内に第１の受信機を設置すると共にこの検出区画の出入口付近に第２の受信機を設置し、検出対象に取り付けられた発信機からの無線信号を上記第１の受信機で受信した場合に当該検出区画内に当該検出対象が入ったと判断し（これを第１の判断と仮称する）、これ以降に検出対象に取り付けられた発信機からの無線信号を上記第２の受信機で受信した場合に当該検出対象が出たと判断して（これを第２の判断と仮称する）上記検出区画内を入出する検出対象を監視する入出監視装置において、
上記第１または第２の受信機が上記発信機からの無線信号を受信した場合、所定時間内に他の受信機が上記発信機からの無線信号を受信しない場合に限り上記第１または第２の判断を行うことを特徴とする。
【０００９】
また、上記受信機が上記発信機からの無線信号を受信したか否かの判断はデータ処理装置内に設けた電界強度比較回路により行い、上記第１または第２の受信機が上記発信機からの無線信号を受信した場合、所定時間内に他の受信機が上記発信機からの無線信号を受信しない場合に限り上記第１または第２の判断を行う手段は、上記データ処理装置内に設けた電界強度比較回路，記憶装置，タイマを用いて行う構成を特徴とする。
【００１０】
【発明の実施の形態】
以下、本発明の実施形態を図面を用いて説明する。図１は本発明の一実施形態を説明するための図で、図において、１は検出区画、２はその出入口、１０は検出対象（移動体）、２０は検出対象１０に装着された発信機、３０ａは検出区画１内の中央付近に設置された受信機、３０ｂは同じく出入口２付近に設置された受信機、４０はデータ処理装置、５０は表示器であり、データ処理装置４０の構成を除いて従来の装置と同様である。
【００１１】
図２は、本実施形態におけるデータ処理装置４０の構成を示すブロック図であり、図において、４０１はモデム、４０２は時刻演算回路、４０３は電界強度比較回路、４０４は表示制御回路、４１０は記憶装置、４１１はタイマである。
【００１２】
次に動作について説明する。従来の装置と同様に各受信機３０は、発信機２０からの無線信号を受信すると、受信電界強度，経過時間，当該発信機２０のＩＤ番号を検出し、これらに自己の発信機番号を付したデータをデータ処理装置４０へ信号として送信する。
データ処理装置４０では、送られてきた信号をモデム４０１で復調し、受信機３０の番号，発信機２０のＩＤ番号，経過時間と受信電界強度とをデータとして出力し、時刻演算回路４０２で受信機３０での受信時刻を算出する。
また電界強度比較回路４０３では、受信電界強度が所定レベル以上ある場合に電波を受信したとする判定、発信機２０からの電波が同時に２台の受信機３０で受信された場合に受信電界強度の強い方の受信機の特定、さらに受信電界強度が同じ場合には出入口２付近に設置した受信機３０ｂから受信したとする特定を行う。
そしてこれら判定，特定されたデータは、表示制御回路４０４へ送られる前に、記憶装置４１０に一時保存され、受信状況を把握した後で表示制御回路４０４に送られる。
【００１３】
次に受信状況の把握について説明する。受信状況の把握は、発信機２０を装着した検出対象１０が検出区画１内に存在する旨が表示器５０に表示されている場合と否とで次のように異なる。
すなわち検出対象１０が検出区画１内に存在する旨が表示されている場合には、電界強度比較回路４０３で発信機２０からの電波が受信機３０ａで受信されていると判断されており、従って記憶装置４１０に、発信機２０のＩＤ番号，受信時刻および受信機３０ａの受信機番号が記憶される。
そして、検出対象１０が移動し、電界強度比較回路４０３での受信電界強度の判断が、受信機３０ｂでより強く受信されたと判断されるようになった場合、記憶装置４１０の記憶内容を消去し、新たに発信機２０のＩＤ番号，受信時刻および受信機３０ｂの受信機番号が記憶される。
そして、タイマ４１１から時間情報を得、一定時間が経過するまで受信機３０ａでの同じＩＤ番号の受信データが来ない場合、記憶装置４１０に記憶した受信機３０ｂでの受信データを表示制御回路４０４に送り、表示器５０上に検出対象１０が存在しない旨が表示される。
【００１４】
一方、タイマ４１１で一定時間が経過する前に電界強度比較回路４０３が同じＩＤ番号の発信機２０からの電波を受信機３０ａで受信した場合（または受信機３０ａからの受信電界強度の方が強くなった場合）には、記憶装置４１０の記憶内容を消去し、新たに発信機２０のＩＤ番号，受信時刻および受信機３０ａの受信機番号を記憶させるが、この時すぐには表示制御回路４０４へこの受信データを送らず、受信電界強度のふらつきによる誤判断を防止する。
【００１５】
すなわち、表示器５０で検出対象１０が検出区画１内に存在すると表示されている場合、電界強度比較回路４０３が受信電界強度のふらつきにより受信機３０ａと３０ｂで交互に受信したと判断しても、表示制御回路４０４にはこのふらつき状態は送られないため表示器５０の表示内容が変化することなく、検出対象１０は検出区画１内に存在していると正確に表示されることになる。
また、検出対象１０が検出区画１内から完全に出た場合には、上述のようなふらつきは発生しないため、タイマ４１１で一定時間経過後に表示器５０の存在を示す表示が消去されることになる。
【００１６】
次に、発信機２０を装着した検出対象１０が検出区画１内に存在しないと表示器５０で表示されている場合の処理について説明する。表示器５０で検出対象１０が検出区画１内に存在しないと表示されている場合、検出対象１０が遠方にいる場合には何れの受信機３０ａ，３０ｂとも発信機２０からの電波は受信されないが、検出対象１０が出入口２に近づくと、電界強度比較回路４０３では受信機３０ｂが受信したと判断する。
そしてこの判断がなされた場合には、記憶装置４１０に発信機２０のＩＤ番号，受信時刻および受信機３０ｂの受信機番号が記憶される。
【００１７】
そして更に検出対象１０が移動して検出区画１内に進入していった場合、発信機２０からの電波が受信機３０ａでも受信されるようになり、さらに受信機３０ａの受信電界強度が強くなり、受信機３０ｂより上回るようになる。
そして受信機３０ａの受信電界強度が上回った場合、電界強度比較回路４０３では発信機２０の電波を受信機３０ａで受信したと判断し、記憶装置４１０の記憶内容を消去し、新たに発信機２０のＩＤ番号，受信時刻および受信機３０ａの受信機番号を記憶させるが、この時すぐには表示制御回路４０４へこのデータは送らない。
【００１８】
そしてタイマ４１１で一定時間が経過するまで受信機３０ｂでの受信がないと電界強度比較回路４０３で判断した場合、記憶装置４１０に記憶した受信機３０ａでの受信データを表示制御回路４０４に送り、表示装置５０に検出対象１０が検出区画１内に存在する旨を表示する。
一方、タイマ４１１で一定時間が経過する前に、電界強度比較回路４０３で発信機２０からの電波を受信機３０ｂが受信したと判断した場合には、記憶装置４１０の記憶内容を消去し、新たに発信機２０のＩＤ番号，受信時刻および受信機３０ｂの受信機番号を記憶するが、この時には一定時間が経過するまで、このデータを表示制御回路４０４へは送らない。
【００１９】
すなわち、表示器５０では検出対象１０が検出区画１内には存在しないと表示されている場合、電界強度比較回路４０３が受信電界強度のふらつきにより受信機３０ａと３０ｂで交互に受信したと判断しても表示制御回路４０４にはそのデータは送られないため表示器５０の表示内容が変化することなく、検出対象１０が検出区画１内に存在しないと正確に表示されることになる。
また、検出対象１０が検出区画１内に完全に進入した場合には、上述のようなふらつきは発生しないため、タイマ４１１で一定時間経過後に検出対象１０が検出区画１内に存在する旨が表示器５０に表示される。
【００２０】
なお、タイマ４１１で設定する所定時間は、設置環境に応じて調整することとする。
【００２１】
【発明の効果】
以上説明したように本発明の入出監視装置は、２台の受信機の中間付近に検出対象が存在し、受信環境の影響等により２台の受信機が交互に検出対象からの電波を受信する様なふらつきが発生する場合でも、誤検出することなく正確な出入りの判断が行えるという効果がある。
【図面の簡単な説明】
【図１】入出監視装置の構成例を示す図である。
【図２】本発明の一実施形態を説明するためのブロック図である。
【図３】従来の装置におけるデータ処理装置を示すブロック図である。
【符号の説明】
１検出区画
２出入口
１０検出対象
２０検出対象１０に装着された発信機
３０ａ検出区画内の中央付近に設置された受信機
３０ｂ出入口２付近に設置された受信機
４０データ処理装置
５０表示器
４０１モデム
４０２時刻演算回路
４０３電界強度比較回路
４０４表示制御回路
４１０記憶装置
４１１タイマ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an entry / exit monitoring device that monitors a detection target entering / exiting a detection section using radio waves.
[0002]
[Prior art]
There are various types of entry / exit monitoring devices that monitor a detection target entering / exiting the detection section. For example, there is a device as shown in FIG.
Although FIG. 1 is also a diagram for explaining an embodiment of the present invention, it is the same as the conventional apparatus except for the configuration of the data processing apparatus 40. Therefore, this type of conventional input / output monitoring apparatus using FIG. Will be explained.
In the figure, 1 is a detection section, 2 is an entrance / exit thereof, 10 is a detection target (moving body), 20 is a transmitter mounted on the detection target 10, 30a is a receiver installed near the center in the detection section 1, Similarly, 30b is a receiver installed near the doorway 2, 40 is a data processing device, and 50 is a display.
It should be noted that the scale of each part is not necessarily accurate for easy understanding of the description.
[0003]
Further, the detection target 10 is a moving body that moves and moves in and out of the detection section 1 from the entrance / exit 2, and only one detection target 10 is shown in FIG. Transmitters 20 that transmit different IDs to the detection target 10 are mounted.
The transmitter 20 and the receiver 30 are connected by a wireless line, and the receivers 30a and 30b, the data processing device 40, and the display 50 are connected by a data signal line.
When each receiver 30 receives a radio signal from the transmitter 20, the received electric field strength, an elapsed time until data is transmitted to the data processing device 40 after reception (hereinafter simply referred to as elapsed time), the transmitter 20 ID numbers of the receivers are detected, and data with the receiver numbers assigned thereto are transmitted to the data processor 40 as signals.
[0004]
FIG. 3 is a block diagram showing the configuration of the processing device 40 used in the conventional entrance / exit monitoring device. In the figure, 401 is a modem, 402 is a time calculation circuit, 403 is an electric field strength comparison circuit, and 404 is a display control circuit. is there.
The modem 401 demodulates the transmitted signal, outputs the receiver 30 number, the transmitter 20 ID number, the elapsed time, and the received electric field strength as data, and the time calculation circuit 402 determines the reception time at the receiver 30. calculate.
Further, the electric field strength comparison circuit 403 determines that the radio wave is received when the received electric field strength is equal to or higher than a predetermined level. When the radio wave from the transmitter 20 is simultaneously received by the two receivers 30, the received electric field strength is strong. The other receiver is specified, and if the received electric field strength is the same, the receiver 30b installed near the entrance / exit 2 is specified to be received.
These determined and specified data are sent to the display control circuit 404, and the display control circuit 404 operates to display the entry / exit status of the detection target 10 on the display 50.
[0005]
Next, the entrance / exit determination performed by the conventional entrance / exit monitoring device will be described. If the receiver 30a receives a radio wave having a predetermined electric field strength or more from the transmitter 20 after the state in which the detection target 10 is determined not to exist in the detection section 1 in the display of the display device 50, the detection section 1 It is determined that the detection target 10 has entered, and a display to that effect is displayed.
In addition, after the display 50 indicates that the detection target 10 is present in the detection section 1, the received electric field strength of the radio wave from the transmitter 20 is greater than the received electric field strength at the receiver 30a. When the received electric field strength at the receiver 30b becomes strong, it is determined that the detection target 10 has come out of the detection section 1, and a display to that effect is displayed. That is, when the radio wave from the transmitter 20 is received by the receiver 30a installed near the center of the detection section 1 (or the received electric field strength is received more strongly by the receiver 30a), the detection target 10 is naturally When it is determined that the object is present in the detection section 1 and is received by the receiver 30b installed near the entrance 2 (or the reception electric field strength is received more strongly by the receiver 30b), the detection object 10 is naturally It exists in the vicinity of the entrance / exit 2 and this means that the detection target 10 exits from the detection section 1. Therefore, it is assumed that the detection target 10 has exited from the detection section 1, and the fact is displayed on the display 50. Is done.
[0006]
[Problems to be solved by the invention]
Since the conventional entrance / exit monitoring device is configured and operates as described above, an erroneous determination may be made when the detection target 10 is located near the middle of the receiver 30a and the receiver 30b.
That is, when the detection target 10 is located near the middle between the receiver 30a and the receiver 30b, the received electric field strength at the receiver 30a and the received electric field strength at the receiver 30b are substantially equal. Due to a change in the reception environment, a wobbling state occurs in which the receiver 30a temporarily becomes stronger or the receiver 30b becomes temporarily stronger.
In the conventional apparatus, even when the detection target 10 is actually stationary in the vicinity of the middle, such a wobbling is detected as it is, so that it is erroneously determined that the entry / exit is repeated, and the display 50 is repeatedly entered / exited. A message will be displayed.
[0007]
The present invention has been made to solve such a problem, and an object thereof is to provide an entry / exit monitoring device capable of accurately detecting entry / exit with a simple configuration.
[0008]
[Means for Solving the Problems]
The entry / exit monitoring device according to the present invention is:
At least a first receiver is installed in the detection section, and a second receiver is installed in the vicinity of the entrance / exit of the detection section, and a radio signal from a transmitter attached to the detection target is received by the first receiver. When it is received, it is determined that the detection target has entered the detection section (this is tentatively referred to as a first determination), and a radio signal from a transmitter attached to the detection target is received after the second reception. In an entry / exit monitoring device that judges that the detection object has come out when it is received by a machine (this is tentatively referred to as a second decision) and monitors the detection object entering and exiting the detection section,
When the first or second receiver receives a radio signal from the transmitter, the first or second receiver only when the other receiver does not receive the radio signal from the transmitter within a predetermined time. It is characterized by making a judgment.
[0009]
Further, whether or not the receiver has received a radio signal from the transmitter is determined by an electric field strength comparison circuit provided in the data processing device, and the first or second receiver is transmitted from the transmitter. The means for making the first or second determination is provided in the data processing apparatus only when the other receiver does not receive the radio signal from the transmitter within a predetermined time when the radio signal is received. It features a configuration that uses an electric field strength comparison circuit, a storage device, and a timer.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of the present invention. In the figure, 1 is a detection section, 2 is an entrance / exit thereof, 10 is a detection target (moving body), 20 is a transmitter mounted on the detection target 10. , 30a is a receiver installed near the center of the detection section 1, 30b is a receiver also installed near the entrance 2 and 40 is a data processing device, 50 is a display, and the configuration of the data processing device 40 is as follows. Except for this, it is the same as the conventional apparatus.
[0011]
FIG. 2 is a block diagram showing the configuration of the data processing apparatus 40 in this embodiment. In the figure, 401 is a modem, 402 is a time calculation circuit, 403 is an electric field strength comparison circuit, 404 is a display control circuit, and 410 is a memory. A device 411 is a timer.
[0012]
Next, the operation will be described. As in the conventional apparatus, each receiver 30 receives the radio signal from the transmitter 20, detects the received electric field strength, the elapsed time, and the ID number of the transmitter 20, and attaches its own transmitter number to these. The processed data is transmitted to the data processing device 40 as a signal.
In the data processing device 40, the transmitted signal is demodulated by the modem 401, the number of the receiver 30, the ID number of the transmitter 20, the elapsed time and the received electric field strength are output as data and received by the time calculation circuit 402. The reception time at the machine 30 is calculated.
The electric field strength comparison circuit 403 determines that the radio wave is received when the received electric field strength is equal to or higher than a predetermined level. If the radio wave from the transmitter 20 is simultaneously received by the two receivers 30, The stronger receiver is specified, and further, when the received electric field strength is the same, the receiver is specified to be received from the receiver 30b installed near the entrance / exit 2.
These determined and specified data are temporarily stored in the storage device 410 before being sent to the display control circuit 404, and are sent to the display control circuit 404 after grasping the reception status.
[0013]
Next, the grasp of the reception status will be described. The grasp of the reception status differs as follows depending on whether or not the display unit 50 displays that the detection target 10 to which the transmitter 20 is attached is present in the detection section 1.
That is, when it is displayed that the detection target 10 exists in the detection section 1, the electric field intensity comparison circuit 403 determines that the radio wave from the transmitter 20 is received by the receiver 30a, and accordingly The storage device 410 stores the ID number of the transmitter 20, the reception time, and the receiver number of the receiver 30a.
Then, when the detection object 10 moves and the determination of the received electric field strength by the electric field strength comparison circuit 403 is determined to be received more strongly by the receiver 30b, the stored contents of the storage device 410 are erased. The ID number of the transmitter 20, the reception time, and the receiver number of the receiver 30b are newly stored.
Then, when the time information is obtained from the timer 411 and the reception data of the same ID number at the receiver 30a does not come until a certain time elapses, the display control circuit 404 displays the reception data at the receiver 30b stored in the storage device 410. And the fact that the detection target 10 does not exist is displayed on the display 50.
[0014]
On the other hand, when the electric field intensity comparison circuit 403 receives the radio wave from the transmitter 20 having the same ID number by the receiver 30a before the fixed time elapses in the timer 411 (or the received electric field intensity from the receiver 30a is stronger. The stored contents of the storage device 410 are erased, and the ID number of the transmitter 20, the reception time and the receiver number of the receiver 30a are newly stored. At this time, the display control circuit 404 The received data is not sent to the terminal, and erroneous determination due to fluctuations in the received electric field strength is prevented.
[0015]
That is, when the display 50 indicates that the detection target 10 is present in the detection section 1, even if the field strength comparison circuit 403 determines that the receivers 30a and 30b have alternately received signals due to fluctuations in the received field strength. Since the wobbling state is not sent to the display control circuit 404, the display content of the display unit 50 does not change, and the detection target 10 is accurately displayed if it exists in the detection section 1.
In addition, when the detection target 10 completely comes out of the detection section 1, the above-described wobble does not occur, so that the display indicating the presence of the display device 50 is erased after a predetermined time has elapsed in the timer 411. Become.
[0016]
Next, processing when the detection target 10 equipped with the transmitter 20 is displayed on the display unit 50 when it does not exist in the detection section 1 will be described. When the display 50 indicates that the detection target 10 does not exist in the detection section 1, when the detection target 10 is far away, neither of the receivers 30a and 30b receives radio waves from the transmitter 20. When the detection target 10 approaches the entrance 2, the electric field strength comparison circuit 403 determines that the receiver 30 b has received.
When this determination is made, the storage device 410 stores the ID number of the transmitter 20, the reception time, and the receiver number of the receiver 30b.
[0017]
When the detection object 10 further moves and enters the detection section 1, the radio wave from the transmitter 20 is also received by the receiver 30a, and the received electric field strength of the receiver 30a is further increased. , Exceeding the receiver 30b.
When the received electric field strength of the receiver 30a exceeds, the electric field strength comparison circuit 403 determines that the radio wave of the transmitter 20 has been received by the receiver 30a, erases the stored contents of the storage device 410, and newly transmits the transmitter 20 The ID number, the reception time, and the receiver number of the receiver 30a are stored, but at this time, this data is not sent to the display control circuit 404.
[0018]
When the electric field strength comparison circuit 403 determines that there is no reception at the receiver 30b until a predetermined time elapses in the timer 411, the reception data at the receiver 30a stored in the storage device 410 is sent to the display control circuit 404, The display device 50 displays that the detection target 10 exists in the detection section 1.
On the other hand, if the receiver 30b determines that the radio wave from the transmitter 20 has been received by the electric field strength comparison circuit 403 before the fixed time has elapsed by the timer 411, the stored contents of the storage device 410 are erased, and a new The ID number of the transmitter 20, the reception time, and the receiver number of the receiver 30b are stored, but at this time, this data is not sent to the display control circuit 404 until a predetermined time elapses.
[0019]
That is, when the display 50 indicates that the detection target 10 does not exist in the detection section 1, the field strength comparison circuit 403 determines that the receivers 30a and 30b have alternately received signals due to fluctuations in the received field strength. However, since the data is not sent to the display control circuit 404, the display content of the display 50 does not change, and if the detection target 10 does not exist in the detection section 1, it is accurately displayed.
In addition, when the detection target 10 has completely entered the detection section 1, the above-described wobble does not occur, so that the timer 411 displays that the detection target 10 exists in the detection section 1 after a predetermined time has elapsed. Displayed on the device 50.
[0020]
Note that the predetermined time set by the timer 411 is adjusted according to the installation environment.
[0021]
【The invention's effect】
As described above, the input / output monitoring device of the present invention has a detection target near the middle of two receivers, and the two receivers alternately receive radio waves from the detection target due to the influence of the reception environment or the like. Even when such wobbling occurs, there is an effect that an accurate entry / exit determination can be made without erroneous detection.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration example of an entry / exit monitoring device.
FIG. 2 is a block diagram for explaining an embodiment of the present invention.
FIG. 3 is a block diagram showing a data processing apparatus in a conventional apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Detection section 2 Entrance / exit 10 Detection target 20 Transmitter 30a attached to the detection target 10 Receiver 30b installed near the center in the detection section Receiver 40 installed near the entrance / exit 2 Data processing device 50 Display 401 Modem 402 Time calculation circuit 403 Field strength comparison circuit 404 Display control circuit 410 Storage device 411 Timer

Claims

少なくとも検出区画内に第１の受信機を設置すると共にこの検出区画の出入口付近に第２の受信機を設置し、検出対象に取り付けられた発信機からの無線信号を上記第１の受信機で受信した場合（ここで言う受信した場合とは、一定以上の受信電界強度で受信した場合であり、また複数の受信機で同時に受信した場合には１番受信電界強度が強い受信機が受信したと見做し、さらに複数の受信機で同じ電界強度で受信した場合には上記第２の受信機で受信したと見做す場合を言う。以下、同じ）に当該検出区画内に当該検出対象が入ったと判断し（これを第１の判断と仮称する）、これ以降に検出対象に取り付けられた発信機からの無線信号を上記第２の受信機で受信した場合に当該検出対象が出たと判断して（これを第２の判断と仮称する）上記検出区画内を入出する検出対象を監視する入出監視装置において、
上記第１または第２の受信機が上記発信機からの無線信号を受信した場合、所定時間内に他の受信機が上記発信機からの無線信号を受信しない場合に限り上記第１または第２の判断を行うことを特徴とする入出監視装置。At least a first receiver is installed in the detection section, and a second receiver is installed in the vicinity of the entrance / exit of the detection section, and a radio signal from a transmitter attached to the detection target is received by the first receiver. When receiving (The case of receiving here is a case where the signal is received with a reception field strength of a certain level or more, and when receiving simultaneously with a plurality of receivers, the receiver with the strongest reception field strength received. And when it is received at the same electric field strength by a plurality of receivers, it is assumed that it is received by the second receiver. (This is tentatively referred to as the first determination.) After that, when the radio signal from the transmitter attached to the detection target is received by the second receiver, the detection target is output. Judgment (This is tentatively called the second judgment. In and out monitoring apparatus for monitoring a detection target into and out of the interior of the detection zone,
When the first or second receiver receives a radio signal from the transmitter, the first or second receiver only when the other receiver does not receive the radio signal from the transmitter within a predetermined time. An entry / exit monitoring device characterized by

上記受信機が上記発信機からの無線信号を受信したか否かの判断はデータ処理装置内に設けた電界強度比較回路により行い、上記第１または第２の受信機が上記発信機からの無線信号を受信した場合、所定時間内に他の受信機が上記発信機からの無線信号を受信しない場合に限り上記第１または第２の判断を行う手段は、上記データ処理装置内に設けた電界強度比較回路，記憶装置，タイマを用いて行う構成を特徴とする請求項第１項記載の入出監視装置。Whether or not the receiver has received a radio signal from the transmitter is determined by an electric field strength comparison circuit provided in the data processing device, and the first or second receiver receives a radio signal from the transmitter. When the signal is received, the means for making the first or second determination only when the other receiver does not receive the radio signal from the transmitter within a predetermined time is the electric field provided in the data processing device. 2. The input / output monitoring apparatus according to claim 1, wherein the input / output monitoring apparatus is configured to use an intensity comparison circuit, a storage device, and a timer.