JP3763722B2 - Mobile device management device - Google Patents

Description

なお、表１において、「矢印」は信号の変化を示し、「コード１」は第１のコード発生器１３Ａからの信号を示し、「コード２」は第２のコード発生器１３Ｂからの信号を示す。また図５において、３４は磁界を示す。
【００２２】
空間１１の内部に設けられたコード発生器１５において、作業者１９がこのコード発生器１５の近傍を通過したことのみを検出すればよい場合は、図１に示すように各位置にそれぞれ一つのコード発生器１５を設置すれば済む。これに対し、その通過方向まで検出したい場合は、図５の場合と同様に各位置において一対のコード発生器を設置すればよい。
【００２３】
図６はコード受信端末２０の構成を示すブロック図である。ここで、３５ｘ、３５ｙ、３５ｚは磁気センサで、コード発生器１３、１５の磁界発生コイル１４、１６によって発生される磁界からのディジタル変調信号を受信することができる。これらの磁気センサ３５ｘ、３５ｙ、３５ｚは、一つの方向の磁界に対して感度が強いという特性を有する。ところで、コード受信端末２０は、作業員１９が携行するが、その持ち方や、ゲート１２などを通過するときの向きなどが毎回異なる。そこで、どのような状態であっても確実に磁界を検出できるように、Ｘ、Ｙ、Ｚの三軸方向に感度を持つように三軸方向に磁気センサ３５ｘ、３５ｙ、３５ｚを配置する。
【００２４】
おのおのの磁気センサ３５ｘ、３５ｙ、３５ｚからの信号は、おのおののアンプ３６ｘ、３６ｙ、３６ｚで増幅され、おのおのの帯域フィルタ３７ｘ、３７ｙ、３７ｚによって、搬送周波数の成分と信号の強度レベルに相当する成分とに分けられる。
【００２５】
搬送周波数の成分の信号は電子スイッチ３８に入力されるが、この電子スイッチ３８は、三つの磁気センサ３５ｘ、３５ｙ、３５ｚからの信号のうち、強度のいちばん高い信号を選択するように切替えを行うものである。この切替えにより選択された最も強度の高い信号は、一対のＦＳＫ検波器３９Ａ、３９Ｂによって、周波数ｆ１およびｆ１＋δｆの２チャンネルの信号として同時に検波され、一対のデータ再生処理部４０Ａ、４０Ｂにてコードフレーム信号に再生されて、マイクロプロセッサ４１に送られる。このように電子スイッチ３８によっていちばん強度の高い信号を選択し、検波、再生するので、安定した検出を行うことができる。
【００２６】
詳細には、復調が可能なレベル以上の受信信号が得られた時点において、三軸方向の磁気センサ３５ｘ、３５ｙ、３５ｚのうち、その受信信号レベルが最大となる軸についての磁気センサを選択して復調する。そして、この選択した軸の磁気センサの受信信号が復調できなくなるレベルまで、この選択した軸の磁気センサを用いた復調を維持する。すなわち、システム内における高速の通信が可能であれば問題ないが、現実には異なる磁気センサが頻繁に選択されるとシステムの処理速度がそれに追いつかない。そこで、磁気センサ３５ｘ、３５ｙ、３５ｚで受信した信号のいずれかが復調可能なレベルに達したときの受信レベルが最大の磁気センサを選択し、復調するとともに、その軸の磁気センサが復調できなくなる値まで信号レベルが低下するまでは、選択した軸を他の軸に変更しないようにする。このようにすることで、安定した信号を得ることができる。
【００２７】
信号の強度レベルに相当する成分は、アナログ−ディジタル変換器４２を通って、ディジタル信号に変換された後に、マイクロプロセッサ４１に入力される。マイクロプロセッサ４１は、受信したフレームデータ（図４）を解析して、作業員１９がゲート１２を通り抜けたことやコード発生器１５が設置されている特定位置を通過したことを検出する。検出結果は、無線通信器４３とアンテナ４４とを経て、無線通信装置１７へ送られる。
【００２８】
図７は、コード受信端末２０のマイクロプロセッサ４１の内部における信号処理の流れを示したものである。コード受信端末２０すなわちマイクロプロセッサ４１の電源が投入されると、それとともに、ステップＳ７０１において磁気信号の受信レベルを監視する連続動作を行い、受信レベルが予め設定した所定のレベルを越えた場合には、ステップＳ７０２において、マイクロプロセッサ４１からの指示によって電子スイッチ３８を切り替える。このとき、二つ以上の信号がしきい値を越えた場合は、受信レベルの強い方の信号を選択する。切り替えられた信号に対し検波器３９Ａ、３９Ｂにより検波が行われ、データ再生処理部４０Ａ、４０Ｂによりコード再生処理が行われる。コード再生処理において同期信号が得られた時点すなわち同期ロックが完了した時点で、ステップＳ７０３でそのことを確認し、続くステップＳ７０４においてデータ再生処理部４０Ａ、４０Ｂからの再生信号をマイクロプロセッサ４１で受信し、１フレーム以上のコードを抽出する。検出の信頼性を向上させるために、２フレーム以上を検出することもある。この時点においても常に同期ロックを確認し、同期ロック信号が得られなくなったら、ステップＳ７０１の磁気信号受信レベルの検出ステージに戻る。
【００２９】
ステップＳ７０４においてコードを正確に抽出した場合には、ステップＳ７０５のコード内容を解析する処理に移る。ここでは、あらかじめ位置コードとゲートコードとそれぞれの方向コード体系とをマイクロプロセッサ４１のメモリに記憶させておき、その内容にもとづき、まず空間１１内の位置のコードかゲート１２のコードかを判別する。
【００３０】
空間１１内の位置のコードである場合において、この位置を通過したことのみを検出すればよいときには、ステップＳ７０６において、その通過があったことについての情報を無線にて管理計算機１８に送信するためのデータフォーマットの作成処理を行う。これに対しゲート１２のコードであれば、ステップＳ７０７において再度同期ロックを確認するとともに、ステップＳ７０８において入場か退出かを判定する。ステップＳ７０７において、同期ロックが外れている場合には、ステップＳ７０１に戻って、磁気信号レベルの確認から再度実行する。
【００３１】
ステップＳ７０８において、入場か退出かを判定する方法の一例として、前述の表１に示した方法がある。すなわち、図５に示す空間１１の外側の第１のコード発生器１３Ａからの信号か、空間１１の内側の第２のコード発生器１３Ｂからの信号かを判別して、外側を検出した後に内側を検出した場合はゲート１２を入場方向に通り抜けたと判定することができる。反対に、内側を検出した後に外側を検出した場合は、ゲート１２を退出方向に通り抜けたと判定することができる。判定処理が完了したら、ステップＳ７０６の、その判定情報を無線にて管理計算機１８に送信するためのデータフォーマットの作成処理を行う。
【００３２】
ステップＳ７０８において、入退出の判定が不能である場合は、ステップＳ７０９において、同期ロックを確認する。ロックが確認されれは、ステップＳ７０４に戻り、データの受信とフレームの取り出しとを行う。ロックが外れている場合は、ステップＳ７０１に戻って、磁気信号レベルの確認から再度実行する。
【００３３】
ステップＳ７０６において上述のように無線伝送フレームを作成したなら、ステップＳ７１０においてデータ伝送を行い、一連の処理を完了する。このように一連の処理を完了したなら、ステップＳ７０１に戻って、磁気信号レベルの確認を再開する。
【００３４】
次に本発明の他の実施の形態について説明する。図５に示すように、ゲート１２の部分では、このゲート１２における入口側と出口側とのそれぞれの天井部分に磁界発生コイル１４、１４が設けられている。すなわち、これら一対の磁界発生コイル１４、１４は、互いに近接して設けられており、上述の図５にもとづいて説明した場合と同様に、互いの磁界３４が干渉しやすい状況にある。この状況は、図示のようなゲート１２の部分のみならず、上述のように図１の空間１１の内部に一対のコード発生器を設けて作業者１９の通過方向をも検出する場合などにおいても発生する。
【００３５】
詳細には、図８に示すように、ゲートの入口側と出口側との天井部分に設けられた磁界発生コイル１４、１４は、それぞれコイルのループが水平面の方向に向くように形成されている。そして、この場合は、それぞれのコイル１４、１４について、図８（ａ）に示すように、コード受信端末２０の磁気センサ３５ｘ、３５ｙ、３５ｚのうちの水平方向の磁場に対して感度を持つものによって検出可能なエリア４６は、水平方向に広がりを持つという傾向を示し、したがって隣り合うものどうしが干渉しやすい。これに対し、図８（ｂ）に示すように、磁気センサ３５ｘ、３５ｙ、３５ｚのうちの鉛直方向の磁場に対して感度を持つものによって検出可能なエリア４７は、鉛直方向に広がりを持つという傾向を示し、したがって隣り合うものどうしの干渉は起こりにくい。
【００３６】
そこで、磁気センサ３５ｘ、３５ｙ、３５ｚのうちの鉛直方向の磁場に対して感度を持つものを選択して、その選択した磁気センサによる検出を行うようにするのが好都合である。このため、図６において仮想線で示すように、コード受信端末２０に加速度センサなどの傾斜センサ４８を設ける。この傾斜センサ４８の出力はマイクロプロセッサ４１に入力させる。
【００３７】
そして、図５に示すコイル１４の磁界３４が検出可能なレベルであることを検出した時点において、傾斜センサ４８からの信号をもとに、磁気センサ３５ｘ、３５ｙ、３５ｚのうちの、図８（ｂ）に示すエリア４７を検出可能な、鉛直方向の磁場に対する感度が一番大きなセンサを選択するように、マイクロプロセッサ４１のソフトウェアにて処理する。また、処理結果にもとづき電子スイッチ３８によって所要の磁気センサへの切り替えを行う。これらの処理は、図７のステップＳ７０１において行う。なお、傾斜センサ４８と磁気センサ３５ｘ、３５ｙ、３５ｚとについてのＸ、Ｙ、Ｚの三軸方向の座標軸を揃えると、磁気センサ３５ｘ、３５ｙ、３５ｚの選択を行うための処理を単純化することができる。
【００３８】
なお、上記においては、図１に示すように閉ざされた空間１１内およびゲート１２の内外における作業員１９の動きを管理する場合を例として説明したが、本発明は、これに限定されるものではなく、人荷や車両がゲートを通過したことを確認したり、これら人荷や車両がどの位置に存在するかを確認したりするための装置として、広く適用できるものである。
【００３９】
【発明の効果】
以上のように本発明によると、定位置に設けられるとともに、コード信号を変調した電流を電路に流すことによってその電路の近傍に磁場を発生させるコード発生器と、移動体に設けられたコード受信端末とを有し、このコード受信端末は、移動体がコード発生器に対応する位置に達したときに前記磁場を感知しこの磁場の信号を復調して電気信号に変換する手段と、この復調された信号を無線によって管理装置に送信する手段とを備えているようにしたため、すなわち磁場を検知することによってコード発生器からのコード信号をコード受信端末によって受信するようにしたため、コード受信端末はコード発生器に対して指向性を持たず、したがってシステムの信頼性を高くすることができ、また磁場を検知するものであるため、これを検知できる範囲が比較的狭く、したがってコード受信端末を備えた移動体がコード発生器の近傍に位置したときにのみ検知が行われ、このため現在位置を管理する場合にその位置を容易に特定することができる。またコード受信端末は、移動体がコード発生器に対応する位置に達したときに前記磁場を感知しこの磁場の信号を復調して電気信号に変換する素子をＸ、Ｙ、Ｚの三軸方向にそれぞれ備えるとともに、各軸の方向の素子により得られる受信信号のうちレベルが最大のものを選択して復調するように構成されているため、安定した検出を行うことができる。
【図面の簡単な説明】
【図１】本発明の移動体管理装置の実施の形態としての人員管理システムの構成を示す図である。
【図２】図１の人員管理システムにおける信号の流れを示す図である。
【図３】図１のコード発生器の構成を示すブロック図である。
【図４】図３のコード発生器にて作成されるデータの構成例を示す図である。
【図５】図１のゲートにおけるコード発生器の設置例を示す図である。
【図６】図１のコード受信端末の構成を示すブロック図である。
【図７】コード受信端末における信号処理の方法を示す図である。
【図８】本発明の他の実施の形態におけるコード発生器の磁界発生コイルについて説明するための図である。
【符号の説明】
１２ ゲート
１３ コード発生器
１５ コード発生器
１７ 無線通信装置
１８ 管理計算機
１９ 作業員
２０ コード受信端末[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile body management device, and in particular, a mobile body for confirming that a human load or a vehicle has passed through a gate, or for checking a position where the human load or a vehicle exists. It relates to a management device.
[0002]
[Prior art]
For example, in a tunnel or other closed space, it is necessary to manage the entry and exit of personnel such as workers and the current position in the space. As a kind of management apparatus for this purpose, an entrance / exit management apparatus for confirming the passage of a gate as described above is known. As this entry / exit management device, there is one using electromagnetic induction or microwave, and an operator carries a tag sensitive to electromagnetic waves or microwaves emitted from the fixing device.
[0003]
[Problems to be solved by the invention]
However, as the antenna on the tag side, a coil is used in the electromagnetic induction type and a patch antenna is used in the microwave type, but these antennas have directivity, so Depending on the relative angle with the antenna on the fixing device side, the detectable distance can be greatly reduced. For this reason, it may be necessary to hold the tag over the antenna on the fixing device side during detection.
[0004]
In addition, in this way, in principle, it is affected by the coupling direction of the field on the fixed device side and the tag side, so that there are restrictions on the method of use, and when the coupling is bad, between the tag and the management device Since communication is not possible, it is difficult to introduce the system into a highly reliable system.
[0005]
Furthermore, in a system using electromagnetic waves, the range that can be communicated becomes too large, and when managing the current position, it may be difficult to specify the position.
Therefore, the present invention solves such a technical problem, and in the mobile management device, the means carried by the mobile body does not have directivity with respect to the fixed device, and therefore the reliability of the system is high, The purpose is to make it easy to specify the position.
[0006]
[Means for Solving the Problems]
  In order to achieve this object, the present invention provides a code generator that is provided at a fixed position and generates a magnetic field in the vicinity of the electric circuit by flowing a current modulated with the code signal through the electric circuit, and a code provided on the moving body. The code receiving terminal senses the magnetic field when the moving body reaches a position corresponding to the code generator, demodulates the signal of the magnetic field, and converts it into an electrical signal.Comprising elements in three directions of X, Y, and Z, respectively, and configured to select and demodulate a received signal having the maximum level among elements received in the direction of each axis; andMeans for wirelessly transmitting the demodulated signal to the management deviceWithIt is what you have done.
[0007]
  With such a configuration, the code generator generates a magnetic field, and the code receiving terminal has means for detecting this magnetic field, that is, the code signal from the code generator is encoded by detecting the magnetic field. Since it is received by the receiving terminal, the code receiving terminal does not have directivity with respect to the code generator, and therefore the reliability of the system is high and the magnetic field is detected. Therefore, the detection is performed only when the mobile object equipped with the code receiving terminal is located in the vicinity of the code generator. Therefore, when the current position is managed, it is easy to specify the position.Further, the code receiving terminal detects the magnetic field when the moving body reaches a position corresponding to the code generator, and demodulates the signal of the magnetic field to convert it into an electrical signal in the X, Y, and Z directions. In addition, each of the received signals obtained by the elements in the directions of the respective axes is configured to select and demodulate the signal having the maximum level, so that stable detection can be performed.
  The present invention also provides a code generator that is provided at a fixed position and generates a magnetic field in the vicinity of the electric circuit by flowing a current modulated with the code signal to the electric circuit, a code receiving terminal provided on the moving body, The code receiving terminal senses the magnetic field when the mobile body reaches a position corresponding to the code generator and demodulates the signal of the magnetic field to convert it into an electrical signal. Means and a means for wirelessly transmitting the demodulated signal to the management device, wherein the code generator is provided on each of an entrance side and an exit side of the gate, and each code generator generates a magnetic field signal to be generated. The code receiving terminal is configured to be able to receive the magnetic field signals having different carrier frequencies from each code generator so as to be distinguished from each other. , And the magnetic field signal received by distinguishing their mutually, based these magnetic field signal to the time received respectively, in which are configured to be determined the direction in which the moving body has passed through the gate.
  In addition, the present invention includes a code generator that generates a magnetic field in the vicinity of an electric circuit by passing a current modulated with a code signal through the electric circuit, and a code receiving terminal provided on a moving body. A plurality of code generators are provided close to each other, and the code receiving terminal senses the magnetic field when the mobile body reaches a position corresponding to the code generator and demodulates a signal of the magnetic field to generate an electric signal. A device for converting into signals is provided in each of the three axial directions of X, Y, and Z, and a device for selecting and demodulating a device having the highest sensitivity to the magnetic field in the vertical direction is provided. And a means for wirelessly transmitting the demodulated signal to the management apparatus.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a configuration of a personnel management system as an embodiment of a mobile management apparatus of the present invention. Here, 11 is a closed space, and a code generator 13 is provided at the entrance / exit, that is, the gate 12. The code generator 13 can oscillate an identification code corresponding to the gate 12 as a near magnetic field signal. Reference numeral 14 denotes a magnetic field generating coil.
[0009]
A code generator 15 similar to that provided in the gate 12 is provided at a predetermined position inside the space 11. The code generator 15 can oscillate an identification code corresponding to its installation position as a near magnetic field signal, and is similarly provided with a magnetic field generating coil 16. A wireless communication device 17 is provided inside the space 11, and this wireless communication device 17 is connected to a management computer 18.
[0010]
Reference numeral 19 denotes a worker who carries the code receiving terminal 20. The code receiving terminal 20 is configured to be able to read an identification code of position information in the form of a near magnetic field signal from the code generators 13 and 15 and to have a personal identification code of the worker 19. . The code receiving terminal 20 includes a wireless transmitter, and is configured to transmit the identification code of the position information and the personal identification code to the wireless communication device 17.
[0011]
In such a configuration, when the worker 19 passes through the gate 12 or passes through a position where the code generator 15 is installed in the space 11, the code receiving terminal 20 carried by the worker 19 is As described above, the identification code of the position information is read in the form of the near magnetic field signal from the code generators 13 and 15. Accordingly, it is possible to detect the gate 12 through which the worker 19 has passed and the specific position through which the worker 19 has passed in the space 11.
[0012]
The code receiving terminal 20 transmits the identification code of the position detected in this way and the personal identification code of the worker 19 to the wireless communication device 17 by the wireless transmitter mounted on the terminal 20. The signal transmitted to the wireless communication device 17 is then sent to the management computer 18. This management computer 18 uses the code number of the position in the gate or space and the identification number of the worker 19 registered in advance in the management computer 18 together with information such as the name of the worker 19 and the current Display location information on the monitor screen. Also, for example, a history of the movement of the worker is recorded and saved.
[0013]
FIG. 2 shows a signal flow in the personnel management system of FIG. In step S201, the code generators 13 and 15 continuously generate the spatial position in which the gate 12 and the code generator 15 are provided from the coils 14 and 16 as near magnetic field signals. As a method of placing a code signal on such a near magnetic field, a method of digitally modulating the magnetic field can be employed.
[0014]
In step S202, the code receiving terminal 20 performs processing so that the magnetic field signal can be constantly received. When the magnetic field signal can be detected, the code receiving terminal 20 performs signal processing for extracting the gate code and the position code from the received magnetic field signal in step S203. I do. Note that the magnetic signal can be detected by the code receiving terminal 20 not only when the gate 12 enters and exits the space 11 through the gate 12 but also when it passes through the vicinity of the gate 12. it can. The code thus extracted is wirelessly transmitted to the personnel management device 21 including the wireless communication device 17 and the management computer 18 in step S204. After the transmission, the process returns to step S202.
[0015]
In step S205, the personnel management device 21 continuously receives a signal from the code receiving terminal 20 and processes the signal. Specifically, the identification code of the terminal 20 is registered in the code receiving terminal 20 carried by the worker 19, and the worker code corresponding to the terminal 20 is registered in the management computer 18 together with the identification code of the terminal 20. Have a pre-registered database. Therefore, the management computer 18 obtains information on the name of the worker 19 by recognizing the above-described identification code for the code receiving terminal 20 from the received signal. At the same time, codes for the positions of the gate 12 and the code generator 15 are obtained. Thereby, in step S206, predetermined information is displayed on a monitor or the like. The management computer 18 constantly monitors whether there is a signal from the code receiving terminal 20.
[0016]
FIG. 3 shows a block diagram of the configuration of the code generators 13 and 15. Each of the code generators 13 and 15 has a code setting unit 25, reads a 12-bit identification code set by the code setting unit 25, and generates one frame of data by the frame generation unit 26. . As shown in FIG. 4, this one-frame data includes the above-described identification code 27, a check code 28 for detecting an error occurring during wireless communication of this identification code, and data synchronization at the time of reception. It is configured as a code to which a preamble 29 is added.
[0017]
Next, the framed signal is placed on the carrier 31 by the modulator 30. Here, an example is shown in which processing is performed using FSK, which is a digital frequency modulation method, but processing may be performed using another modulation method such as ASK or PSK. Then, in order to limit the band of the modulated signal, the signal is processed by the band limiting filter 32. After that, the power of the signal is amplified by the power amplifier 33, and a current is passed through the coils 14 and 16 to generate a magnetic field.
[0018]
FIG. 5 shows a specific installation structure of the code generator 13 in the gate 12. Hereinafter, a signal processing method related to entry and exit based on this structure will be described. When detecting the movement of the worker 19 at the gate 12, in addition to having passed through the gate 12, it is important to identify the situation of the passage in order to perform reliable personnel management. For example, it is important to identify whether it has passed through the gate 12, whether the passing direction is the entrance direction or the leaving direction, or whether it has passed through the vicinity of the gate 12 but has not passed through it. It is.
[0019]
Therefore, as shown in FIG. 5, a code generator, that is, a first code generator 13A and a second code generator 13B are installed on the outer side and the inner side of the gate 12, respectively, and the respective code generators 13A, 13B are installed. Assign different gate codes to each. At this time, if the distance between the code generators 13A and 13B can be increased, the magnetic fields do not interfere with each other and the identification is easy. Therefore, there is a risk of causing interference with each other in the magnetic field. Therefore, interference can be suppressed by changing the carrier frequency modulated by the code generators 13A and 13B. That is, let the frequency of the carrier wave of the code generator 13A provided outside the space 11 be f1, and let the frequency of the carrier wave of the code generator 13B provided inside be f1 + δf. In this way, only one of the signals can be extracted by the filtering process at the time of reception.
[0020]
When determining entry / exit, the movement of the worker 19 is determined from the received signal, that is, the history of code changes, based on Table 1. However, the code receiving terminal 20 is provided with a function of simultaneously detecting the two carrier waves.
[0021]
[Table 1]

In Table 1, “Arrow” indicates a change in signal, “Code 1” indicates a signal from the first code generator 13A, and “Code 2” indicates a signal from the second code generator 13B. Show. In FIG. 5, reference numeral 34 denotes a magnetic field.
[0022]
In the code generator 15 provided in the space 11, when it is only necessary to detect that the operator 19 has passed through the vicinity of the code generator 15, one is provided at each position as shown in FIG. 1. A code generator 15 may be installed. On the other hand, when it is desired to detect the passing direction, a pair of code generators may be installed at each position as in the case of FIG.
[0023]
FIG. 6 is a block diagram showing the configuration of the code receiving terminal 20. Here, 35x, 35y, and 35z are magnetic sensors, and can receive a digital modulation signal from the magnetic field generated by the magnetic field generating coils 14 and 16 of the code generators 13 and 15. These magnetic sensors 35x, 35y, and 35z have a characteristic that they are highly sensitive to a magnetic field in one direction. By the way, the code receiving terminal 20 is carried by the worker 19, but the way of holding it, the direction when passing through the gate 12, and the like are different every time. Therefore, the magnetic sensors 35x, 35y, and 35z are arranged in the three-axis directions so as to have sensitivity in the three-axis directions of X, Y, and Z so that the magnetic field can be reliably detected in any state.
[0024]
The signals from the respective magnetic sensors 35x, 35y, and 35z are amplified by the respective amplifiers 36x, 36y, and 36z, and components corresponding to the carrier frequency component and the signal intensity level are respectively obtained by the bandpass filters 37x, 37y, and 37z. And divided.
[0025]
The carrier frequency component signal is input to the electronic switch 38. The electronic switch 38 performs switching so as to select the signal having the highest intensity among the signals from the three magnetic sensors 35x, 35y, and 35z. Is. The signal having the highest intensity selected by this switching is simultaneously detected as a two-channel signal of the frequencies f1 and f1 + δf by the pair of FSK detectors 39A and 39B, and the code frame is detected by the pair of data reproduction processing units 40A and 40B. The signal is reproduced and sent to the microprocessor 41. Thus, the electronic switch 38 selects the signal with the highest intensity, and detects and reproduces it, so that stable detection can be performed.
[0026]
Specifically, when a received signal with a level that can be demodulated or higher is obtained, the magnetic sensor for the axis having the maximum received signal level is selected from the three-axis magnetic sensors 35x, 35y, and 35z. Demodulate. Then, the demodulation using the magnetic sensor of the selected axis is maintained until the received signal of the magnetic sensor of the selected axis cannot be demodulated. That is, there is no problem if high-speed communication is possible in the system, but in reality, when different magnetic sensors are frequently selected, the processing speed of the system cannot keep up with it. Therefore, the magnetic sensor having the maximum reception level when any of the signals received by the magnetic sensors 35x, 35y, and 35z reaches a level that can be demodulated is selected and demodulated, and the magnetic sensor on the axis cannot be demodulated. Until the signal level drops to the value, the selected axis is not changed to another axis. In this way, a stable signal can be obtained.
[0027]
A component corresponding to the intensity level of the signal is converted into a digital signal through the analog-digital converter 42 and then input to the microprocessor 41. The microprocessor 41 analyzes the received frame data (FIG. 4) and detects that the worker 19 has passed through the gate 12 and has passed a specific position where the code generator 15 is installed. The detection result is sent to the wireless communication device 17 via the wireless communication device 43 and the antenna 44.
[0028]
FIG. 7 shows the flow of signal processing inside the microprocessor 41 of the code receiving terminal 20. When the power of the code receiving terminal 20, that is, the microprocessor 41 is turned on, a continuous operation for monitoring the reception level of the magnetic signal is performed at the same time, and if the reception level exceeds a predetermined level set in advance. In step S702, the electronic switch 38 is switched according to an instruction from the microprocessor 41. At this time, if two or more signals exceed the threshold value, the signal having the stronger reception level is selected. The switched signals are detected by the detectors 39A and 39B, and the code reproduction processing is performed by the data reproduction processing units 40A and 40B. When the synchronization signal is obtained in the code reproduction process, that is, when the synchronization lock is completed, this is confirmed in step S703, and in step S704, the reproduction signal is received by the microprocessor 41 from the data reproduction processing units 40A and 40B. Then, a code of one frame or more is extracted. In order to improve detection reliability, two or more frames may be detected. Even at this time, the synchronization lock is always confirmed, and if the synchronization lock signal cannot be obtained, the process returns to the magnetic signal reception level detection stage in step S701.
[0029]
If the code is correctly extracted in step S704, the process proceeds to the process of analyzing the code content in step S705. Here, the position code, the gate code, and the respective direction code system are stored in advance in the memory of the microprocessor 41, and based on the contents, it is first determined whether the code is a position code in the space 11 or a code of the gate 12. .
[0030]
In the case of a code of a position in the space 11, when it is only necessary to detect that it has passed through this position, in step S 706, information about the passage has been transmitted to the management computer 18 by radio. Create the data format. On the other hand, in the case of the code of the gate 12, the synchronization lock is confirmed again in step S707, and whether entry or exit is determined in step S708. If the synchronization lock is released in step S707, the process returns to step S701, and the process is executed again after confirming the magnetic signal level.
[0031]
As an example of a method for determining whether to enter or leave in step S708, there is the method shown in Table 1 above. That is, it is determined whether the signal is from the first code generator 13A outside the space 11 shown in FIG. 5 or from the second code generator 13B inside the space 11, and after detecting the outside, the inside is detected. Can be determined to have passed through the gate 12 in the entrance direction. On the other hand, when the outside is detected after the inside is detected, it can be determined that the gate 12 has passed in the exit direction. When the determination process is completed, a data format creation process for transmitting the determination information to the management computer 18 wirelessly is performed in step S706.
[0032]
If it is not possible to determine entry / exit in step S708, the synchronization lock is confirmed in step S709. If the lock is confirmed, the process returns to step S704 to receive data and extract a frame. If the lock is released, the process returns to step S701, and the process is executed again after confirming the magnetic signal level.
[0033]
If a wireless transmission frame is created as described above in step S706, data transmission is performed in step S710, and a series of processing is completed. When a series of processes is completed in this way, the process returns to step S701 and the confirmation of the magnetic signal level is resumed.
[0034]
Next, another embodiment of the present invention will be described. As shown in FIG. 5, in the gate 12 portion, magnetic field generating coils 14 and 14 are provided at the ceiling portions of the gate 12 on the entrance side and the exit side. That is, the pair of magnetic field generating coils 14 and 14 are provided close to each other, and the magnetic field 34 is likely to interfere with each other as in the case described with reference to FIG. This situation occurs not only in the portion of the gate 12 as shown in the figure, but also in the case where a pair of code generators are provided in the space 11 of FIG. appear.
[0035]
Specifically, as shown in FIG. 8, the magnetic field generating coils 14 and 14 provided on the ceiling portions of the entrance side and the exit side of the gate are formed so that the loops of the coils respectively face the horizontal plane. . In this case, each of the coils 14 and 14 has sensitivity to a horizontal magnetic field among the magnetic sensors 35x, 35y, and 35z of the code receiving terminal 20, as shown in FIG. The area 46 that can be detected by the above has a tendency to spread in the horizontal direction, so that adjacent objects are likely to interfere with each other. On the other hand, as shown in FIG. 8 (b), the area 47 that can be detected by the magnetic sensor 35x, 35y, 35z that has sensitivity to the vertical magnetic field is said to have a vertical spread. It shows a tendency, so that interference between adjacent ones hardly occurs.
[0036]
Therefore, it is convenient to select one of the magnetic sensors 35x, 35y, and 35z that has sensitivity to the magnetic field in the vertical direction and perform detection by the selected magnetic sensor. For this reason, as shown by a virtual line in FIG. 6, an inclination sensor 48 such as an acceleration sensor is provided in the code receiving terminal 20. The output of the tilt sensor 48 is input to the microprocessor 41.
[0037]
Then, when it is detected that the magnetic field 34 of the coil 14 shown in FIG. 5 is at a detectable level, the magnetic sensor 35x, 35y, 35z of FIG. Processing is performed by software of the microprocessor 41 so as to select a sensor capable of detecting the area 47 shown in b) and having the highest sensitivity to the magnetic field in the vertical direction. Further, based on the processing result, the electronic switch 38 switches to a required magnetic sensor. These processes are performed in step S701 in FIG. If the coordinate axes in the X, Y, and Z directions of the tilt sensor 48 and the magnetic sensors 35x, 35y, and 35z are aligned, the process for selecting the magnetic sensors 35x, 35y, and 35z is simplified. Can do.
[0038]
In the above description, the case of managing the movement of the worker 19 in the closed space 11 and inside and outside the gate 12 as shown in FIG. 1 has been described as an example. However, the present invention is not limited to this. Instead, it can be widely applied as a device for confirming that a human load or a vehicle has passed through a gate or for confirming a position where the human load or the vehicle exists.
[0039]
【The invention's effect】
  As described above, according to the present invention, a code generator that is provided at a fixed position and that generates a magnetic field in the vicinity of an electric circuit by passing a current obtained by modulating a code signal through the electric circuit, and a code receiver that is provided on a moving body. The code receiving terminal senses the magnetic field when the mobile body reaches a position corresponding to the code generator, demodulates the signal of the magnetic field, and converts the magnetic field signal into an electrical signal. Since the code receiving terminal is configured to receive the code signal from the code generator by detecting the magnetic field, the code receiving terminal It is not directional to the code generator, so it can increase the reliability of the system and detect the magnetic field. The possible range is relatively narrow, so detection is only performed when a mobile with a code receiving terminal is located in the vicinity of the code generator, so it is easy to identify the location when managing the current location Can do.Further, the code receiving terminal detects the magnetic field when the moving body reaches a position corresponding to the code generator, and demodulates the signal of the magnetic field to convert it into an electrical signal in the X, Y, and Z directions. In addition, each of the received signals obtained by the elements in the directions of the respective axes is configured to select and demodulate the signal having the maximum level, so that stable detection can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a personnel management system as an embodiment of a mobile management apparatus of the present invention.
FIG. 2 is a diagram showing a signal flow in the personnel management system of FIG. 1;
FIG. 3 is a block diagram showing a configuration of the code generator of FIG. 1;
4 is a diagram showing a configuration example of data created by the code generator of FIG. 3;
FIG. 5 is a diagram illustrating an installation example of a code generator at the gate of FIG. 1;
6 is a block diagram showing a configuration of the code receiving terminal of FIG. 1. FIG.
FIG. 7 is a diagram illustrating a signal processing method in a code receiving terminal.
FIG. 8 is a diagram for explaining a magnetic field generating coil of a code generator according to another embodiment of the present invention.
[Explanation of symbols]
12 Gate
13 Code generator
15 Code generator
17 Wireless communication device
18 Management computer
19 workers
20 code receiving terminal

Claims (5)

A code generator that is provided at a fixed position and generates a magnetic field in the vicinity of the electric circuit by passing a current modulated in the code signal through the electric circuit;
A code receiving terminal provided on the mobile body,
In this code receiving terminal, when the mobile body reaches a position corresponding to the code generator, an element that senses the magnetic field, demodulates the signal of the magnetic field, and converts it into an electrical signal in the X, Y, and Z directions together provided respectively, the level of the received signal obtained by the direction of the elements of each axis is configured to demodulate by selecting the largest one, and means for transmitting the demodulated signal to the management apparatus by the radio management system of the mobile, characterized in that it comprises.   2. The mobile management apparatus according to claim 1, wherein the code receiving terminal is configured to maintain demodulation using the element of the selected axis up to a level at which the selected received signal cannot be demodulated. .   The mobile body has a gate that can pass through, and code generators are provided on the entrance side and the exit side of the gate, respectively, and each code generator is configured so that the carrier frequency of the generated magnetic field signal is different, and the code reception The terminal is configured to be able to distinguish and receive magnetic field signals having different carrier frequencies from the respective code generators, and to receive the magnetic field signals that are distinguished from each other and the times at which these magnetic field signals are received respectively. 3. The mobile body management apparatus according to claim 1, wherein the mobile body management apparatus is configured to determine a direction in which the mobile body has passed through the gate. A code generator that is provided at a fixed position and generates a magnetic field in the vicinity of the electric circuit by passing a current modulated in the code signal through the electric circuit;
A code receiving terminal provided on the mobile body;
And a gate through which the moving body can pass,
The code receiving terminal senses the magnetic field when the mobile body reaches a position corresponding to the code generator, demodulates a signal of the magnetic field, and converts the demodulated signal into an electric signal. Means for transmitting to the management device,
The code generator is provided on each of an entrance side and an exit side of the gate,
Each code generator is configured so that the carrier frequency of the generated magnetic field signal is different,
The code receiving terminal is configured to be able to receive magnetic field signals having different carrier frequencies from each code generator, and to receive the magnetic field signals received separately from each other. The moving body management apparatus is configured to be able to determine the direction in which the moving body has passed through the gate based on the determined time. A code generator that is provided at a fixed position and generates a magnetic field in the vicinity of the electric circuit by passing a current modulated in the code signal through the electric circuit;
A code receiving terminal provided on the mobile body,
A plurality of the code generators are provided close to each other,
The code receiving terminal senses the magnetic field when the moving body reaches a position corresponding to the code generator, and demodulates the signal of the magnetic field to convert it into an electrical signal in the X, Y, and Z directions. And a means for selecting one of these elements having the maximum sensitivity to the magnetic field in the vertical direction and performing demodulation , and means for wirelessly transmitting the demodulated signal to the management device A mobile body management device comprising:

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