JP2004112482A

JP2004112482A - Position detecting method and system, and radio communication apparatus

Info

Publication number: JP2004112482A
Application number: JP2002273702A
Authority: JP
Inventors: Hitoshi Hayashi; 等林; Masafumi Shimizu; 清水　雅史; Toshimitsu Tsubaki; 椿　俊光
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: Nippon Telegraph and Telephone Corp
Priority date: 2002-09-19
Filing date: 2002-09-19
Publication date: 2004-04-08
Anticipated expiration: 2022-09-19
Also published as: JP3829784B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detecting method and system capable of estimating a position of a radio communication terminal with high accuracy without much receiving the effect of an environment around the radio communication terminal. <P>SOLUTION: The position detecting method and system obtain a relative probability distribution between a predicted location of the radio communication terminal and a received signal strength depending on a past history of the location of the radio communication terminal and the received signal strength and applies weighting to the distribution so as to estimate the location of the radio communication terminal without being affected by an environment variation around the radio communication terminal. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、位置検出方法及びシステム及び無線通信端末に係り、特に、無線通信端末の位置を検出するシステムにおける無線通信端末の周囲の環境の影響を大きく受けることなく高い精度で無線通信端末の位置を検出するための位置検出方法及びシステム及び無線通信端末に関する。
【０００２】
【従来の技術】
従来の位置検出システムとしては、図７に示すようなシステムがある。
【０００３】
同図に示すシステムは、電波を送信する送信局１３１と、送信局１３１からの電波を受信してその強度を測定する少なくとも３つ以上の基地局１３２と、各基地局１３２によって測定された受信信号強度データにより送信局１３１と各基地局１３２との間の距離をそれぞれ求め、送信局１３１の位置を推定するセンタ局１３３とを有している。
【０００４】
このシステムでは、送信局１３１は、検出動作中電波を発信する。各基地局１３２は、送信局１３１からの電波を受信してその受信信号強度を計測し、結果をセンタ局１３３へ送信する。センタ局１３３は、各基地局１３２で受信した受信信号強度データにより送信局１３１と基地局１３２との間の距離をそれぞれ求め、各基地局１３２の位置に対する関係で送信局１３１の位置を推定する。
【０００５】
ここで、送信局１３１から送信された電波は、送信局１３１から遠ざかるにつれて弱くなる。従って、各基地局１３２で受信される電波の強さ、即ち、受信信号強度がわかれば、各基地局１３２から送信局１３１がどれだけ離れた位置に存在しているかは推定できる。そのため、センタ局１３３では、受信信号強度と距離との関係を示すテーブルが予め記憶されており、受信信号強度をこのテーブルに当てはめることで距離を求めている。
【０００６】
このとき、一つの基地局の電波を受信するだけでは方角が分からないため、送信局１３１の位置は、基地局周囲の等高線上どこかまでしかわからないが、図７に示すように、３つの基地局１３２の無線ゾーンが重なっており、基地局１３２でそれぞれ送信局１３１からの電波の受信信号強度を検出できれば、各基地局電波の等高線の交点より送信局１３１の位置を求めることができる。送信局１３１において受信できる基地局の数が増えれば、送信局１３１の存在範囲をもっと絞ることも可能であり、正確な等高線をきめ細かく描いた受信信号強度地図が得られれば、送信局１３１の位置をさらに精度よく検出することができる。このシステムでは、受信信号強度と距離との関係を示すテーブルを正確に作成することにより位置を正確に推定することが可能になる（例えば、特許文献１参照）。
【０００７】
【特許文献１】
特開平９−１５９７４６号公報。
【０００８】
【発明が解決しようとする課題】
しかしながら、上記従来の位置検出システムでは、受信信号強度と距離との関係を示すテーブルを正確に作成することにより位置を正確に推定することが可能になるが、例えば図８のように、送信局１３１と基地局１３２ｂとの間に一時的な遮蔽物１３４が生じた場合など、送信局１３１の推定位置が１３１’に移動してしまい、正確な位置を推定できないという問題がある。
【０００９】
上記のように、従来の位置検出システムにおいては、例えば、送信局と基地局との間に一時的な遮蔽物が生じた場合など、送信局の周囲の環境の影響により受信信号強度が変動し、正確な位置を推定できないという問題がある。
【００１０】
本発明は、上記の点に鑑みなされたもので、従来の位置検出システムにおいて、例えば、送信局と基地局との間に一時的な遮蔽物が生じた場合など、送信局の周囲の環境の影響により受信信号強度が変動した場合に、正確な位置を推定できないという問題点を克服し、無線通信端末の位置を高い精度で推定することが可能な位置検出方法及びシステム及び無線通信端末を提供することを目的とする。
【課題を解決するための手段】
図１は、本発明の原理を説明するための図である。
【００１１】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも送信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなるシステムにおける位置検出方法において、
基地局は、
無線通信端末から送信される無線信号を各々受信し（ステップ１）、
受信した信号の受信信号強度を測定して（ステップ２）、情報サーバに送信し（ステップ３）、
情報サーバは、
基地局から受信信号強度を受信し、受信信号強度を用いて、各受信信号強度に対応する無線通信端末の存在し得る範囲を求め、各範囲の重なりから無線通信端末の存在位置を検出する（ステップ４）。
【００１２】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも受信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなるシステムにおける位置検出方法において、
基地局は、
無線信号を無線通信端末に送信し、
無線通信端末は、
基地局からの無線信号を受信し、
無線信号の受信信号強度を測定し、
自端末内の情報サーバにおいて、受信信号強度を用いて、各受信信号強度に対応する無線通信端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する。
【００１３】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも受信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなるシステムにおける位置検出方法において、
無線通信端末は、
無線信号を基地局に送信し、
基地局は、
無線通信端末から送信される無線信号を各々受信し、
受信した信号の受信信号強度を測定して、無線通信端末に送信し、
無線通信端末は、
複数の基地局から送信される受信信号強度を受信し、
自端末内の情報サーバにおいて、
受信した受信信号強度を用いて、各受信信号強度に対応する無線通信端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する。
【００１４】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも送信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなるシステムにおける位置検出方法において、
基地局は、
無線通信端末に無線信号を送信し、
無線通信端末は、
基地局から送信される無線信号を受信して受信信号強度を測定し、基地局に送信し、
基地局は、
無線通信端末から受信した受信信号強度を情報サーバに送信し、
情報サーバは、
基地局から受信した受信信号強度を用いて、各受信信号強度に対応する無線通信端末の存在し得る範囲を求め、各範囲の重なりから該無線通信端末の存在位置を検出する。
【００１５】
図２は、本発明の原理構成図である。
【００１６】
本発明は、通信ネットワークに接続される複数の基地局２と、該基地局２に無線で接続される移動局としての少なくとも送信手段を有する複数の無線通信端末１と、該無線通信端末１の位置情報を含む情報を管理する情報サーバ３と、からなる位置検出システムであって、
基地局２は、
無線通信端末１から送信される無線信号を各々受信する受信手段２１と、
受信した信号の受信信号強度を測定して、情報サーバ３に送信する強度送信手段２２と、を有し、
情報サーバ３は、
基地局２から受信信号強度を受信する強度受信手段３１と、
受信信号強度を用いて、各受信信号強度に対応する無線通信端末１の存在し得る範囲を求め、各範囲の重なりから無線通信端末１の存在位置を検出する位置検出手段３２と、を有する。
【００１７】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも受信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなる位置検出システムであって、
基地局は、
無線通信端末に無線信号を送信する送信手段を有し、
無線通信端末は、情報サーバを含み、
受信した無線信号の受信信号強度を測定して、情報サーバに渡す受信強度測定手段を有し、
情報サーバは、
受信信号強度を用いて、各受信信号強度に対応する自端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する位置検出手段を有する。本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも受信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなる位置検出システムであって、
基地局は、
無線通信端末から送信される無線信号を受信する受信手段と、
受信した信号の受信信号強度を測定して、無線通信端末に送信する強度送信手段と、を有し、
無線通信端末は、情報サーバを含み、
複数の基地局から送信される受信信号強度を受信する強度受信手段とを有し、
情報サーバは、
受信した受信信号強度を用いて、各受信信号強度に対応する自端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する位置検出手段を有する。
【００１８】
本発明は、通信ネットワークに接続される複数の基地局と、該基地局に無線で接続される移動局としての少なくとも送信手段を有する複数の無線通信端末と、該無線通信端末の位置情報を含む情報を管理する情報サーバと、からなる位置検出システムであって、
基地局は、
無線通信端末に無線信号を送信する送信手段と、
無線通信端末から受信した受信信号強度を情報サーバに送信する第１の強度送信手段と、を有し、
無線通信端末は、
基地局から送信される無線信号を受信して受信信号強度を測定し、基地局に送信する第２の強度送信手段とを有し、
情報サーバは、
基地局から受信した受信信号強度を用いて、各受信信号強度に対応する無線通信端末の存在し得る範囲を求め、各範囲の重なりから該無線通信端末の存在位置を検出する位置検出手段を有する。
【００１９】
本発明は、位置検出手段において、
無線通信端末の存在位置と受信信号強度の過去の履歴から該無線通信端末の移動速度と移動方向と該受信信号強度の変化を予測する第１の予測手段と、
無線通信端末の予測される存在位置と該受信信号強度の相対的な確率分布を求め、重み付けを行う第１の重み付け手段を含む。
【００２０】
本発明は、位置検出手段において、
基地局の無線ゾーン内にある複数の無線通信端末の存在位置と受信信号強度の過去の履歴から無線通信端末の移動速度と移動方向と該受信信号強度の変化を予測する第２の予測手段と、
無線通信端末の予測される存在位置と該受信信号強度の相対的な確率分布を求め、等価的に屋内外の該無線通信端末が合理的に存在する場所に対する方向やエリアに対して重み付けを行う第２の重み付け手段を含む。
【００２１】
本発明は、無線通信端末において、
無線通信端末が移動したことを検出する移動検出手段と、
移動検出手段で無線通信端末が移動した場合にのみ測位を行う手段を含む。
【００２２】
本発明は、移動検出手段において、振動センサを用いる。
【００２３】
本発明は、無線通信の無線通信媒体として、電磁波・音波・光、あるいは、これらの組み合わせを用いる。
【００２４】
本発明は、無線通信に用いる電磁波・音波・光の指向性を変化させる。
【００２５】
本発明は、無線通信端末において、ＧＰＳ衛星からの送信電波を受信する手段を有し、屋外での存在位置の検出に併用する。
【００２６】
本発明は、無線通信端末において、固有の標識番号を伝達する無線タグであるものとする。
【００２７】
本発明は、無線通信端末を、携帯電話、ＰＨＳ、無線通信機能付きＰＤＡ、無線通信機能付きパーソナルコンピュータを含む通信用の携帯機器とする。
【００２８】
本発明は、通信ネットワークに接続される複数の基地局に無線で接続される移動局としての少なくとも受信手段を有する無線通信端末であって、
自端末の位置情報を含む情報を管理する情報サーバと、
複数の基地局から送信される受信信号強度を受信する強度受信手段と、を有し、
情報サーバは、
受信した受信信号強度を用いて、各受信信号強度に対応する自端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する位置検出手段を有する。
【００２９】
本発明は、通信ネットワークに接続される複数の基地局に無線で接続される移動局としての少なくとも受信手段を有する無線通信端末であって、
自端末の位置情報を含む情報を管理する情報サーバと、
複数の基地局から送信される無線信号を受信して、該無線信号の受信信号強度を測定する受信信号測定手段と、を有し、
情報サーバは、
受信信号強度を用いて、各受信信号強度に対応する自端末の存在し得る範囲を求め、各範囲の重なりから自端末の存在位置を検出する位置検出手段を有する。上記のように、本発明では、位置検出システムにおいて、測位の際に無線通信端末の存在位置と受信信号強度の過去の履歴から無線通信端末の移動速度と受信信号強度の変化を予測し、無線通信端末の予測される存在位置と受信信号強度の相対的な確率分布を求め、重み付けを行うことを特徴としている。この場合、例えば、無線通信端末と基地局との間に一時的な遮蔽物が生じた場合など、無線通信端末の周囲の環境の影響により受信信号強度が変動した場合に生じる推定位置の不合理な移動を抑圧し、過去の移動速度と移動方向と受信信号強度から予測される合理的な範囲内に推定位置を留めることができる。
【００３０】
また、本発明では、無線ゾーン内にある複数の無線通信端末の存在位置と基地局での受信信号強度の過去の履歴から無線通信端末の移動速度と移動方向と受信信号強度の変化を予測し、無線通信端末の予測される存在位置と受信信号強度の相対的な確率分布を求め、等価的に屋外においては車道や歩道・道路・ビル・駅など、屋内においては、廊下や机などの無線通信端末が合理的に存在する場所に対する方向やエリアに対して重み付けを行うことを特徴としている。この場合、例えば、無線通信端末が車並みに高速で移動しているのにもかかわらず、推定位置が車道や線路から突然外れる場合や、車道から突然線路に推定位置が移動する場合など、不合理な予測を回避することができる。
【００３１】
また、本発明では、無線通信端末が移動した場合にのみ測位を行うことを特徴としている。この場合、例えば、無線通信端末が移動していない場合など、情報サーバに管理されている位置情報を更新する必要がなくなり、位置情報の処理の負担とデータ量を減らすことができる。
【００３２】
また、本発明では、無線通信端末の移動を検知する手段として振動センサを用いることを特徴としている。この場合、例えば、無線通信端末を持っている人が歩行している場合など、簡易に移動を検出することができる。
【００３３】
また、本発明では、無線通信媒体として、電磁波・音波・光あるいは、これらの組み合わせを用いることを特徴としている。この場合、同じ環境下でも媒体によって伝搬状況が異なるため、それらを比較することで、測位の精度を高めることができる。
【００３４】
また、本発明では、無線通信に用いる電磁波・音波・光等の指向性を変化させることを特徴としている。この場合、基地局からみた無線通信端末の方向を絞り込むことができ、測位の精度を高めることができる。
【００３５】
また、本発明では、無線通信端末がＧＰＳ衛星からの送信電波を受信する機能を有し、屋外での存在位置の検出に併用することを特徴としている。この場合、屋外における測位の精度を高めることができる。
【００３６】
また、本発明では、無線通信端末は、携帯電話、ＰＨＳ、無線通信機能付きＰＤＡ、無線通信機能付きパーソナルコンピュータ等の通信用の携帯端末であることを特徴としている。この場合、このような携帯端末を所持する人の位置を検出することができる。
【００３７】
【発明の実施の形態】
以下、図面と共に本発明の実施の形態を説明する。
【００３８】
［第１の実施の形態］
図３は、本発明の第１の実施の形態における位置検出システムの構成・動作を示す。
【００３９】
同図に示す位置検出システムは、電波を送信する無線通信端末１と、無線通信端末１からの電波を受信してその強度を測定する少なくとも３つ以上の基地局２と、各基地局２によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する情報サーバ３とを有している。
【００４０】
このシステムでは、無線通信端末１は検出動作中電波を発信する。各基地局２は、無線通信端末１からの電波を受信してその受信信号強度を計測し、結果を情報サーバ３へ送信する。
【００４１】
情報サーバ３は、各基地局２で受信したサンプリング時間［ｔ］における受信信号強度データｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］により無線通信端末１と基地局２との間の距離をそれぞれ求め、各基地局２の位置に対する関係で無線通信端末１の存在位置ｐ’［ｔ］を推定する（ステップ１０１）。
【００４２】
この場合、基地局２の周囲の環境は一様ではなく、例えば、屋外においては樹木や建物等種々の地物が、屋内では、壁やドアが存在するため、基地局２での受信信号強度の等高線は一般に基地局を中心とする同心円とはならない。そのため、実測によるマッピングを行うか、あるいは、いくつかの地点で測定した値を基に受信信号強度と距離との関係を示す近似値やテーブルを適応的に作成して情報サーバ３に記憶させておき、受信信号強度から距離を求めている。
【００４３】
さらに、情報サーバ３では、無線通信端末１の存在位置と受信信号強度の過去の履歴から無線通信端末１の移動速度と移動方向と受信信号強度の変化を予測し、無線通信端末１の予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝を求める（ステップ１０２）。例えば、図３では、無線通信端末１の存在位置と受信信号強度の履歴として、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における無線通信端末１の過去の位置ｐ［ｔ−３］，ｐ［ｔ−２］，ｐ［ｔ−１］、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ａでの過去の受信信号強度ｒａ［ｔ−３］，ｒａ［ｔ−２］，ｒａ［ｔ−１］、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ｂでの過去の受信信号強度ｒｂ［ｔ−３］，ｒｂ［ｔ−２］，ｒｂ［ｔ−１］、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ｃでの過去の受信信号強度ｒｃ［ｔ−３］，ｒｃ［ｔ−２］，ｒｃ［ｔ−１］が求められている。
【００４４】
最後に、ステップ１０１で求めた存在位置ｐ’［ｔ］と受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］をステップ１０２で求めた予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝で重み付けし、最終的な存在位置ｐ［ｔ］と受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］を決定する（ステップ１０３）。
【００４５】
例えば、図３において、計測した存在位置ｐ’［ｔ］と予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝から最終的な存在位置ｐ［ｔ］を求めてみる。ｐ’［ｔ］の座標を（ｘ’［ｔ］，ｙ’［ｔ］，ｚ’［ｔ］，ｐ’’［ｔ］）の相対的な確率分布｛ｐ’’［ｔ］｝のうち、相対的な存在確率が一番高くなる（１００％となる）ｐ０　’’［ｔ］の座標を（ｘ０　’’［ｔ］，ｙ０　’’［ｔ］，ｚ０　’’［ｔ］）とし、ｐ’［ｔ］の位置の相対的な存在確率が１０％の場合には、ｐ［ｔ］の座標である（ｘ［ｔ］，ｙ［ｔ］，ｚ［ｔ］）は、例えば、
ｘ＝（１００ｘ０　’’＋１０ｘ’）／１１０
ｙ＝（１００ｙ０　’’＋１０ｙ’）／１１０　　　　　　　　（１）
ｚ＝（１００ｚ０　’’＋１０ｚ’）／１１０
として重み付けして求めることができる。
【００４６】
同様に、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ　］，ｒｃ’［ｔ］と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ　］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ　］｝，｛ｒｃ’’［ｔ］｝から最終的な受信信号強度ｒａ［ｔ］，ｒｂ［ｔ　］，ｒｃ［ｔ］を求めてみる。ｒａ’’［ｔ］，ｒｂ’’［ｔ　］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ　］｝，｛ｒｃ’’［ｔ］｝のうち相対的な存在確率が一番高くなる（１００％となる）受信信号強度をｒａ０　’’［ｔ］，ｒｂ０　’’［ｔ］，ｒｃ０　’’［ｔ］とし、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ　］，ｒｃ’［ｔ］の相対的な存在確率がそれぞれ１０％の場合には、受信信号強度ｒａ［ｔ］，ｒｂ［ｔ　］，ｒｃ［ｔ］は、例えば、
ｒａ＝（１００ｒａ０　’’＋１０ｒａ’）／１１０
ｒｂ＝（１００ｒｂ０　’’＋１０ｒｂ’）／１１０　　　　　（２）
ｒｃ＝（１００ｒｃ０　’’＋１０ｒｃ’）／１１０
として重み付けして求めることができる。
【００４７】
この場合、例えば、無線通信端末１と基地局２との間に一時的な遮蔽物が生じたなど、無線通信端末１の周囲の環境の影響により受信信号強度が変動した場合に生じる推定位置の不合理な移動を抑圧し、過去の移動速度と移動方向と受信信号強度から予測される合理的な範囲内に推定位置を留めることができる。
【００４８】
なお、第１の実施の形態では、無線通信端末１が電波を送信し、基地局２が無線通信端末１からの電波を受信してその強度を測定し、情報サーバ３が各基地局２によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する構成であったが、基地局２が電波を送信し、無線通信端末１が基地局２からの電波を受信してその強度を測定し、その結果を基地局２に送信して情報サーバ３が無線通信端末１によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する構成でもよい。
【００４９】
また、以上の測位は、無線通信端末１が移動した場合にのみ行うようにしてもよい。この場合、例えば、無線通信端末１が移動していない場合など、情報サーバ３に管理されている位置情報を更新する必要がなくなり、位置情報の処理の負担とデータ量を減らすことができる。
【００５０】
さらに、この無線通信端末１の移動を検知する手段として振動センサを用いるようにしてもよい。この場合、例えば、無線通信端末１を持っている人が歩行している場合など、簡易に移動を検出することができる。
【００５１】
図４は、本発明の第１の実施の形態における振動センサを用いた無線通信端末の移動を検出する構成例を示す図である。
【００５２】
倒立振り子１４を用いた振動センサ１３を無線通信端末１に具備することによって実現できる。保持回路１５は、電極１４ａ、電極１４ｂが接触したとき（あるいは離れたとき）のみ無線通信端末１の電源１７を短時間だけオンさせ、間欠送信をさせる機能を有する。これにより、無線通信端末１が動いた場合のみ電波を送信するようにできる。
【００５３】
また、無線通信媒体として、電磁波・音波・光あるいは、これらの組み合わせを用いてもよい。この場合、同じ環境下でも媒体によって伝搬状況が異なるため、これらを比較することで測位の精度を高めることができる。
【００５４】
また、無線通信端末１がＧＰＳ衛星からの送信電波を受信する機能を有し、屋外での存在位置の検出に併用してもよい。この場合、屋外における測位の精度を高めることができる。
【００５５】
また、無線通信端末１として固有の標識番号を伝達する無線タグを用いてもよい。この場合、このような無線タグを物品等に取り付けた場合に、その物品の位置を検出することができる。
【００５６】
また、無線通信端末１として携帯電話、ＰＨＳ、無線通信機能付きＰＤＡ、無線通信機能付きパーソナルコンピュータ等の通信用の携帯端末を用いてもよい。この場合、このような携帯端末を所持する人の位置を検出することができる。
【００５７】
［第２の実施の形態］
図５は、本発明の第２の実施の形態の位置検出システムの構成・動作を示す図である。
【００５８】
同図に示す位置検出システムは、電波を送信する少なくとも３つ以上の基地局２と、基地局２からの電波を受信してその強度を測定する無線通信端末１とを有している。
【００５９】
無線通信端末１は、無線通信端末１によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置を管理する情報サーバ３を有している。
【００６０】
このシステムでは、基地局２は、検出動作中電波を発信する。無線通信端末１は、各基地局２からの電波を受信してその受信信号強度を計測し、結果を情報サーバ３に蓄積する。
【００６１】
情報サーバ３は、無線通信端末１で受信したサンプリング時間［ｔ］における受信信号強度データｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］により無線通信端末１と基地局２との間の距離をそれぞれ求め、各基地局２の位置に対する関係で無線通信端末１の存在位置ｐ’［ｔ］を推定する（ステップ２０１）。
【００６２】
この場合、基地局２の周囲の環境は一様ではなく、例えば、屋外においては樹木や建物等種々の地物が、屋内では壁やドアが存在するため、無線通信端末１での受信信号強度の等高線は一般に基地局を中心とする同心円とはならない。そのため、実測によるマッピングを行うか、あるいはいくつかの地点で測定した値を基に、受信信号強度と距離との関係を示す近似式やテーブルを適応的に作成して情報サーバ３に記憶させておき、受信信号強度から距離を求めている。
【００６３】
さらに、情報サーバ３では、無線通信端末１の存在位置と受信信号強度の過去の履歴から無線通信端末１の移動速度と移動方向と受信信号強度の変化を予測し、無線通信端末１の予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝を求める（ステップ２０２）。例えば、図５では、無線通信端末１の存在位置と受信信号強度の過去の履歴として、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における無線通信端末１の過去の位置ｐ［ｔ−３］，ｐ［ｔ−２］，ｐ［ｔ−１］，サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ａからの過去の受信信号強度ｒａ［ｔ−３］，ｒａ［ｔ−２］，ｒａ［ｔ−１］、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ｂから過去の受信信号強度ｒｂ［ｔ−３］，ｒｂ［ｔ−２］，ｒｂ［ｔ−１］、サンプリング時間［ｔ−３］，［ｔ−２］，［ｔ−１］における基地局２ｃから過去の受信信号強度ｒｃ［ｔ−３］，ｒｃ［ｔ−２］，ｒｃ［ｔ−１］が求められている。
【００６４】
最後に、ステップ２０１で求めた存在位置ｐ’’［ｔ］と受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］をステップ２０２で求めた予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝で重み付けし、最終的な存在位置ｐ［ｔ］と受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］を決定する（ステップ２０３）。
【００６５】
例えば、図３において、計測した存在位置ｐ’［ｔ］と予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝から最終的な存在位置ｐ［ｔ］を求めてみる。ｐ’［ｔ］の座標を（ｘ’［ｔ］，ｙ’［ｔ］，ｚ’［ｔ］）、ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝のうち相対的な存在確率が一番高くなる（１００％となる）ｐ０　’’［ｔ］の座標を（ｘ０　’’［ｔ］，ｙ０　’’［ｔ］，ｚ０　’’［ｔ］）とし、ｐ’［ｔ］の位置の相対的な存在確率が１０％の場合には、ｐ［ｔ］の座標である（ｘ［ｔ］，ｙ［ｔ］，ｚ［ｔ］）は、例えば、
ｘ＝（１００ｘ０　’’＋１０ｘ’）／１１０
ｙ＝（１００ｙ０　’’＋１０ｙ’）／１１０　　　　　　　（３）
ｚ＝（１００ｚ０　’’＋１０ｚ’）／１１０
として重み付けして求めることができる。
【００６６】
同様に、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝から最終的な受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］を求めてみる。ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝のうち相対的な存在確率が一番高くなる（１００％となる）受信信号強度をｒａ０　’’［ｔ］，ｒｂ０　’’［ｔ］，ｒｃ０　’’［ｔ］とし、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］の相対的な存在確率がそれぞれ１０％の場合には、受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］は、例えば、
ｒａ＝（１００ｒａ０　’’＋１０ｒａ’）／１１０
ｒｂ＝（１００ｒｂ０　’’＋１０ｒｂ’）／１１０　　　　（４）
ｒｃ＝（１００ｒｃ０　’’＋１０ｒｃ’）／１１０
として重み付けして求めることができる。
【００６７】
この場合、例えば、無線通信端末１と基地局２との間に一時的な遮蔽物が生じた等、無線通信端末１の周囲の環境の影響により受信信号強度が変動した場合に生じる推定位置の不合理な移動を抑圧し、過去の移動速度と移動方向と受信信号強度から予測される合理的な範囲内に推定位置を留めることができる。
【００６８】
なお、第２の実施の形態では、基地局２が電波を送信し、無線通信端末１が基地局２からの電波を受信して、その強度を測定し、情報サーバ３が無線通信端末１によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する構成であったが、無線通信端末１が電波を送信し、基地局２が無線通信端末１からの電波を受信してその強度を測定し、その結果を無線通信端末１に送信して情報サーバ３が無線通信端末１によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する構成でもよい。
【００６９】
［第３の実施の形態］
図６は、本発明の第３の実施の形態の位置検出システムの構成・動作を示す図である。
【００７０】
同図に示す位置検出システムは、電波を送信する無線通信端末１と、無線通信端末１からの電波を受信してその強度を測定する少なくとも３つ以上の基地局２と、各基地局２によって測定された受信信号強度データにより無線通信端末１と各基地局２との間の距離をそれぞれ求め、無線通信端末１の位置情報を管理する情報サーバ３とを有している。このシステムでは、無線通信端末１は、検出動作中電波を発信する。各基地局２は、無線通信端末１からの電波を受信してその受信信号強度を計測し、結果を情報サーバ３へ送信する。
【００７１】
情報サーバ３は、各基地局２で受信したサンプリング時間［ｔ］における受信信号強度データｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］により無線通信端末１と基地局２との間の距離をそれぞれ求め、各基地局２の位置に対する関係で無線通信端末１の存在位置ｐ’［ｔ］を推定する（ステップ３０１）。
【００７２】
この場合、基地局２の周囲の環境は一様ではなく、例えば、屋外においては樹木や建物等種々の地物が、屋内では壁やドアが存在するため、基地局２での受信信号強度の等高線は一般に基地局を中心とする同心円とはならない。そのため、実測によるマッピングを行うか、あるいは、いくつかの地点で測定した値をもとに受信信号強度と距離との関係を示す近似式やテーブルを適応的に作成して情報サーバ３に記憶させておき、受信信号強度から距離を求めている。
【００７３】
さらに、情報サーバ３では、基地局２の無線ゾーン内にある複数の無線通信端末の存在位置と受信信号強度の過去の履歴を参照し、屋外においては車道や歩道・線路・ビル・駅など、屋内においては廊下や机などの無線通信端末が合理的に存在する場所に対する方向やエリアに対して無線通信端末１の予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝を求める（ステップ３０２）。
【００７４】
例えば、図６では、池５と車道６、ビル７、駐車スペース８を表示しているが、無線通信端末を携帯している人の過去の流れを把握し、例えば、無線通信端末１を携帯している人が池５に向かう確率は小さく、ビル７の出入口に向かう確率が大きく、また、駐車スペース８の出入口にも向かう確率が大きい場合を、点線で示している。
【００７５】
最後に、ステップ３０１で求めた存在位置ｐ’［ｔ］と受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］をステップ３０２で求めた予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝と受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝で重み付けし、最終的な存在位置ｐ［ｔ］と受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］を決定する（ステップ３０３）。
【００７６】
例えば、図６において、計測した存在位置ｐ’［ｔ］と予測される存在位置ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝から最終的な存在位置ｐ［ｔ］を求めてみる。ｐ’［ｔ］の座標を（ｘ’［ｔ］，ｙ’［ｔ］，ｚ’［ｔ］）、ｐ’’［ｔ］の相対的な確率分布｛ｐ’’［ｔ］｝のうち、相対的な存在確率が一番高くなる（１００％となる）ｐ０　’’［ｔ］の座標を（ｘ０　’’［ｔ］，ｙ０　’’［ｔ］，ｚ０　’’［ｔ］）とし、ｐ’［ｔ］の位置の相対的な存在確率が１０％の場合には、ｐ［ｔ］の座標である（ｘ［ｔ］，ｙ［ｔ］，ｚ［ｔ］）は、例えば、
ｘ＝（１００ｘ０　’’＋１０ｘ’）／１１０
ｙ＝（１００ｙ０　’’＋１０ｙ’）／１１０　　　　　　　（５）
ｚ＝（１００ｚ０　’’＋１０ｚ’）／１１０
として重み付けをして求めることができる。
【００７７】
同様に、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］と予測される受信信号強度ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝から最終的な受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］を求めてみる。ｒａ’’［ｔ］，ｒｂ’’［ｔ］，ｒｃ’’［ｔ］の相対的な確率分布｛ｒａ’’［ｔ］｝，｛ｒｂ’’［ｔ］｝，｛ｒｃ’’［ｔ］｝のうち相対的な存在確率が一番高くなる（１００％となる）受信信号強度をｒａ０　’’［ｔ］，ｒｂ０　’’［ｔ］，ｒｃ０　’’［ｔ］とし、計測した受信信号強度ｒａ’［ｔ］，ｒｂ’［ｔ］，ｒｃ’［ｔ］の相対的な存在確率がそれぞれ１０％の場合には、受信信号強度ｒａ［ｔ］，ｒｂ［ｔ］，ｒｃ［ｔ］は、例えば、
ｒａ＝（１００ｒａ０　’’＋１０ｒａ’）／１１０
ｒｂ＝（１００ｒｂ０　’’＋１０ｒｂ’）／１１０　　　　（６）
ｒｃ＝（１００ｒｃ０　’’＋１０ｒｃ’）／１１０
として重み付けをして求めることができる。
【００７８】
この場合、例えば、無線通信端末１が車並みに高速で移動しているのにもかかわらず、推定位置が車道や線路から突然外れる場合や、車道から突然線路に推定位置が移動する場合など、不合理な予測を回避することができる。
【００７９】
以上述べた実施の形態は全て本発明を例示的に示すものであって限定的に示すものではなく、本発明は、他の種々の変形態様及び変更態様で実施することができる。従って、本発明の範囲は特許請求の範囲及びその均等範囲によってのみ規定されるものである。
【００８０】
【発明の効果】
以上説明したように本発明によれば、従来の位置検出システムにおいて、例えば、放送局と基地局との間に一時的な遮蔽物が生じた場合など、送信局の周囲の環境により受信信号強度が変動した場合に、正確な位置を推定できないという問題点を克服し、無線通信端末の位置を高い精度で推定することの可能な位置検出システムを実現することができる。
【００８１】
詳しくは、本発明によれば、位置検出システムにおいて、測位の際に無線通信端末の存在位置と受信信号強度の過去の履歴から無線通信端末の移動速度と受信信号強度の変化を予測し、無線通信端末の予測される存在位置と受信信号強度の相対的な確率分布を求め、重み付けを行うことを特徴としている。この場合、例えば、無線通信端末と基地局との間に一時的な遮蔽物が生じた場合など、無線通信端末の周囲の環境の影響により受信信号強度が変動した場合に生じる推定位置の不合理な移動を抑圧し、過去の移動速度と移動方向と受信信号強度から予測される合理的な範囲内に推定位置を留めることができる。
【００８２】
また、本発明によれば、基地局の無線ゾーン内にある複数の無線通信端末の存在位置と基地局や無線通信端末での受信信号強度の過去の履歴から無線通信端末の移動速度と移動方向と受信信号強度の変化を予測し、無線通信端末の予測される存在位置と受信信号強度の相対的な確率分布を求め、等価的に屋外においては車道や歩道・道路・ビル・駅など、屋内においては、廊下や机などの無線通信端末が合理的に存在する場所に対する方向やエリアに対して重み付けを行うことにより、例えば、無線通信端末に車並みに高速で移動しているのにもかかわらず、推定位置が車道や線路から突然外れる場合や、車道から突然線路に推定位置が移動する場合など、不合理な予測を回避することができる。
【００８３】
また、本発明によれば、無線通信端末が移動した場合にのみ測位を行うことにより、例えば、無線通信端末が移動していない場合など、情報サーバに管理されている位置情報を更新する必要がなくなり、位置情報の処理の負担とデータ量を減らすことができる。
【００８４】
また、本発明によれば、無線通信端末の移動を検知する手段として振動センサを用いることにより、例えば、無線通信端末を持っている人が歩行している場合など、簡易に移動を検出することができる。
【００８５】
また、本発明によれば、無線通信媒体として、電磁波・音波・光あるいは、これらの組み合わせを用いることにより、同じ環境下でも媒体によって伝搬状況が異なるため、それらを比較することで、測位の精度を高めることができる。
【００８６】
また、本発明によれば、無線通信に用いる電磁波・音波・光等の指向性を変化させることにより、基地局からみた無線通信端末の方向を絞り込むことができ、測位の精度を高めることができる。
【００８７】
また、本発明によれば、無線通信端末がＧＰＳ衛星からの送信電波を受信する手段を有し、屋外での存在位置の検出に併用することにより、屋外における測位の精度を高めることができる。
【００８８】
また、本発明によれば、無線通信端末として、携帯電話、ＰＨＳ、無線通信機能付きＰＤＡ、無線通信機能付きパーソナルコンピュータ等の通信用の携帯端末を用いることにより、このような携帯端末を所持する人の位置を検出することができる。
【図面の簡単な説明】
【図１】本発明の原理を説明するための図である。
【図２】本発明の原理構成図である。
【図３】本発明の第１の実施の形態の位置検出システムの構成・動作を示す図である。
【図４】本発明の第１の実施の形態における振動センサを用いた無線通信端末の移動を検出する構成例を示す図である。
【図５】本発明の第２の実施の形態の位置検出システムの構成・動作を示す図である。
【図６】本発明の第３の実施の形態の位置検出システムの構成・動作を示す図である。
【図７】従来の位置検出システムの構成を示す図である。
【図８】遮蔽物１３４が基地局１３２ｂと送信局１３１の間に生じた場合を示す図である。
【符号の説明】
１　無線通信端末
２　基地局
３　情報サーバ
５　池
６　車道
７　ビル
８　駐車スペース
１３　振動センサ
１４　倒立振り子
１４ａ，１４ｂ　電極
１５　保持回路
１７　電源
２１　受信手段
２２　強度送信手段
３１　強度受信手段
３２　位置検出手段
１３１　送信局
１３２ａ，１３２ｂ，１３２　基地局
１３３　センタ局
１３４　遮蔽物[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a position detecting method and system, and a wireless communication terminal, and more particularly, to a position of a wireless communication terminal with high accuracy without being greatly affected by the environment around the wireless communication terminal in a system for detecting the position of the wireless communication terminal. And a wireless communication terminal.
[0002]
[Prior art]
As a conventional position detection system, there is a system as shown in FIG.
[0003]
The system shown in FIG. 1 includes a transmitting station 131 that transmits radio waves, at least three or more base stations 132 that receive radio waves from the transmitting station 131 and measures the intensity thereof, and a reception station that is measured by each base station 132. It has a center station 133 that determines the distance between the transmitting station 131 and each base station 132 based on the signal strength data and estimates the position of the transmitting station 131.
[0004]
In this system, the transmitting station 131 transmits a radio wave during the detection operation. Each base station 132 receives the radio wave from the transmitting station 131, measures the received signal strength, and transmits the result to the center station 133. The center station 133 obtains the distance between the transmitting station 131 and the base station 132 based on the received signal strength data received by each base station 132, and estimates the position of the transmitting station 131 in relation to the position of each base station 132. .
[0005]
Here, the radio wave transmitted from the transmitting station 131 becomes weaker as the distance from the transmitting station 131 increases. Therefore, if the strength of the radio wave received by each base station 132, that is, the received signal strength is known, it is possible to estimate how far the transmitting station 131 is located from each base station 132. Therefore, in the center station 133, a table indicating the relationship between the received signal strength and the distance is stored in advance, and the distance is obtained by applying the received signal strength to this table.
[0006]
At this time, since the direction is not known only by receiving the radio wave of one base station, the position of the transmitting station 131 is known only to some extent on the contour line around the base station, but as shown in FIG. If the wireless zones of the stations 132 overlap, and if the base station 132 can detect the received signal strength of the radio wave from the transmitting station 131, the position of the transmitting station 131 can be obtained from the intersection of the contour lines of the base station radio waves. If the number of base stations that can be received by the transmitting station 131 increases, the range of the transmitting station 131 can be further narrowed, and if a received signal strength map in which accurate contour lines are finely drawn is obtained, the position of the transmitting station 131 can be reduced. Can be detected with higher accuracy. In this system, it is possible to accurately estimate a position by accurately creating a table indicating a relationship between a received signal strength and a distance (for example, see Patent Document 1).
[0007]
[Patent Document 1]
JP-A-9-159746.
[0008]
[Problems to be solved by the invention]
However, in the above-described conventional position detection system, it is possible to accurately estimate the position by accurately creating a table indicating the relationship between the received signal strength and the distance. For example, as shown in FIG. For example, when the temporary shield 134 is generated between the base station 132 and the base station 132b, the estimated position of the transmitting station 131 moves to 131 ′, and there is a problem that an accurate position cannot be estimated.
[0009]
As described above, in the conventional position detection system, for example, when a temporary obstruction occurs between the transmitting station and the base station, the received signal strength fluctuates due to the influence of the environment around the transmitting station. However, there is a problem that an accurate position cannot be estimated.
[0010]
The present invention has been made in view of the above points, and in a conventional position detection system, for example, when a temporary obstruction occurs between a transmission station and a base station, the environment around the transmission station is not affected. Provided is a position detection method, a system, and a wireless communication terminal capable of estimating a position of a wireless communication terminal with high accuracy by overcoming a problem that an accurate position cannot be estimated when a received signal strength fluctuates due to an influence. The purpose is to do.
[Means for Solving the Problems]
FIG. 1 is a diagram for explaining the principle of the present invention.
[0011]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server for managing information; and
The base station
Receiving wireless signals transmitted from the wireless communication terminals (step 1);
The received signal strength of the received signal is measured (Step 2) and transmitted to the information server (Step 3),
The information server
Received signal strength is received from the base station, a range in which the wireless communication terminal corresponding to each received signal strength can exist is obtained using the received signal strength, and the location of the wireless communication terminal is detected from the overlap of each range ( Step 4).
[0012]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server for managing information; and
The base station
Transmitting a wireless signal to the wireless communication terminal,
The wireless communication terminal
Receiving radio signals from base stations,
Measure the received signal strength of the radio signal,
The information server in the own terminal uses the received signal strength to obtain a range in which the wireless communication terminal corresponding to each received signal strength can exist, and detects the location of the own terminal from the overlap of the ranges.
[0013]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server for managing information; and
The wireless communication terminal
Transmitting the radio signal to the base station,
The base station
Receiving each of the wireless signals transmitted from the wireless communication terminal,
Measure the received signal strength of the received signal, send it to the wireless communication terminal,
The wireless communication terminal
Receiving received signal strengths transmitted from a plurality of base stations,
In the information server in own terminal,
Using the received signal strength received, a range in which the wireless communication terminal corresponding to each received signal strength can exist is obtained, and the location of the own terminal is detected from the overlap of the ranges.
[0014]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server for managing information; and
The base station
Transmitting a wireless signal to the wireless communication terminal,
The wireless communication terminal
Receiving the radio signal transmitted from the base station, measuring the received signal strength, transmitting to the base station,
The base station
Transmitting the received signal strength received from the wireless communication terminal to the information server,
The information server
Using the received signal strength received from the base station, a range in which the wireless communication terminal corresponding to each received signal strength can exist is determined, and the location of the wireless communication terminal is detected from the overlap of the ranges.
[0015]
FIG. 2 is a diagram illustrating the principle of the present invention.
[0016]
The present invention relates to a plurality of base stations 2 connected to a communication network, a plurality of wireless communication terminals 1 having at least transmitting means as mobile stations wirelessly connected to the base stations 2, An information server 3 for managing information including position information,
The base station 2
Receiving means 21 for respectively receiving wireless signals transmitted from the wireless communication terminal 1,
Strength transmitting means 22 for measuring the received signal strength of the received signal and transmitting the measured signal strength to the information server 3;
The information server 3
Strength receiving means 31 for receiving the received signal strength from the base station 2,
A position detection unit that determines a range in which the wireless communication terminal 1 can exist corresponding to each received signal strength by using the received signal strength, and detects an existing position of the wireless communication terminal 1 from an overlap of the ranges.
[0017]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server that manages information;
The base station
Having transmission means for transmitting a radio signal to the radio communication terminal,
The wireless communication terminal includes an information server,
Measuring the received signal strength of the received wireless signal, having a received strength measuring means to pass to the information server,
The information server
There is provided a position detecting means for obtaining a range in which the own terminal can exist corresponding to each received signal strength by using the received signal strength, and detecting an existing position of the own terminal from the overlap of the respective ranges. The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server that manages information;
The base station
Receiving means for receiving a wireless signal transmitted from the wireless communication terminal;
Measuring the received signal strength of the received signal, and strength transmitting means for transmitting to the wireless communication terminal,
The wireless communication terminal includes an information server,
And strength receiving means for receiving the received signal strength transmitted from a plurality of base stations,
The information server
There is provided a position detecting means for obtaining a range in which the own terminal can exist corresponding to each received signal strength using the received received signal strength, and detecting an existing position of the own terminal from the overlap of the respective ranges.
[0018]
The present invention includes a plurality of base stations connected to a communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and position information of the wireless communication terminals. An information server that manages information;
The base station
Transmitting means for transmitting a wireless signal to the wireless communication terminal;
First strength transmitting means for transmitting the received signal strength received from the wireless communication terminal to the information server,
The wireless communication terminal
Second strength transmitting means for receiving a radio signal transmitted from the base station, measuring the received signal strength, and transmitting the signal to the base station,
The information server
Using the received signal strength received from the base station, obtains a range where the wireless communication terminal corresponding to each received signal strength can exist, and has position detecting means for detecting the location of the wireless communication terminal from the overlap of each range. .
[0019]
The present invention relates to a position detecting means,
First predicting means for predicting a moving speed, a moving direction, and a change in the received signal strength of the wireless communication terminal from an existing position of the wireless communication terminal and a past history of the received signal strength;
A first weighting means for obtaining a relative probability distribution between a predicted location of the wireless communication terminal and the received signal strength and performing weighting is provided.
[0020]
The present invention relates to a position detecting means,
Second prediction means for predicting a moving speed and a moving direction of the wireless communication terminal and a change in the received signal strength from the past positions of the plurality of wireless communication terminals in the wireless zone of the base station and the past history of the received signal strength; ,
A relative probability distribution between the expected location of the wireless communication terminal and the received signal strength is obtained, and weighting is performed on directions and areas relative to a place where the wireless communication terminal is rationally located indoors and outdoors. A second weighting means is included.
[0021]
The present invention relates to a wireless communication terminal,
Movement detection means for detecting that the wireless communication terminal has moved,
It includes means for performing positioning only when the wireless communication terminal moves by the movement detecting means.
[0022]
The present invention uses a vibration sensor in the movement detecting means.
[0023]
The present invention uses electromagnetic waves, sound waves, light, or a combination thereof as a wireless communication medium for wireless communication.
[0024]
The present invention changes the directivity of electromagnetic waves, sound waves, and light used for wireless communication.
[0025]
According to the present invention, a wireless communication terminal has means for receiving a transmission radio wave from a GPS satellite, and is used for detecting an existing position outdoors.
[0026]
The present invention is assumed to be a wireless tag for transmitting a unique sign number in a wireless communication terminal.
[0027]
In the present invention, the wireless communication terminal is a communication portable device including a mobile phone, a PHS, a PDA with a wireless communication function, and a personal computer with a wireless communication function.
[0028]
The present invention is a wireless communication terminal having at least a receiving unit as a mobile station wirelessly connected to a plurality of base stations connected to a communication network,
An information server that manages information including location information of its own terminal,
And strength receiving means for receiving the received signal strength transmitted from the plurality of base stations,
The information server
There is provided a position detecting means for obtaining a range in which the own terminal can exist corresponding to each received signal strength using the received received signal strength, and detecting an existing position of the own terminal from the overlap of the respective ranges.
[0029]
The present invention is a wireless communication terminal having at least receiving means as a mobile station wirelessly connected to a plurality of base stations connected to a communication network,
An information server that manages information including location information of its own terminal,
Received radio signals transmitted from a plurality of base stations, and received signal measuring means for measuring the received signal strength of the radio signal,
The information server
There is provided a position detecting means for obtaining a range in which the own terminal can exist corresponding to each received signal strength by using the received signal strength, and detecting an existing position of the own terminal from the overlap of the respective ranges. As described above, in the present invention, in the position detection system, at the time of positioning, the change in the moving speed and the received signal strength of the wireless communication terminal is predicted based on the existing position of the wireless communication terminal and the past history of the received signal strength. It is characterized in that a relative probability distribution between a predicted location of a communication terminal and a received signal strength is obtained and weighted. In this case, for example, when the reception signal strength fluctuates due to the influence of the surrounding environment of the wireless communication terminal, such as when a temporary obstacle occurs between the wireless communication terminal and the base station, the estimated position is unreasonable. And the estimated position can be kept within a reasonable range predicted from the past moving speed, moving direction, and received signal strength.
[0030]
Further, according to the present invention, a change in the moving speed, the moving direction, and the received signal strength of the wireless communication terminal is predicted from the existing positions of the plurality of wireless communication terminals in the wireless zone and the past history of the received signal strength at the base station. The relative probability distribution between the expected location of the wireless communication terminal and the received signal strength is calculated, and equivalently, wirelessly such as a roadway, sidewalk, road, building, station, etc. outdoors, or a corridor, desk, etc. indoors It is characterized in that a direction or an area for a place where a communication terminal is rationally located is weighted. In this case, for example, the estimated position suddenly deviates from the roadway or the track, or the estimated position suddenly moves from the roadway to the track even though the wireless communication terminal is moving at the same speed as the car. A reasonable prediction can be avoided.
[0031]
Further, the present invention is characterized in that positioning is performed only when the wireless communication terminal moves. In this case, for example, when the wireless communication terminal is not moving, there is no need to update the position information managed by the information server, and the load of processing the position information and the data amount can be reduced.
[0032]
Further, the present invention is characterized in that a vibration sensor is used as means for detecting movement of the wireless communication terminal. In this case, for example, when a person holding the wireless communication terminal is walking, movement can be easily detected.
[0033]
Further, the present invention is characterized in that electromagnetic waves, sound waves, light or a combination thereof is used as a wireless communication medium. In this case, even in the same environment, the propagation status differs depending on the medium. Therefore, by comparing them, the accuracy of positioning can be improved.
[0034]
Further, the present invention is characterized in that the directivity of electromagnetic waves, sound waves, light, and the like used for wireless communication is changed. In this case, the direction of the wireless communication terminal as viewed from the base station can be narrowed, and the accuracy of positioning can be increased.
[0035]
Further, the present invention is characterized in that the wireless communication terminal has a function of receiving a transmission radio wave from a GPS satellite, and is also used for detecting an existing position outdoors. In this case, the accuracy of positioning outdoors can be improved.
[0036]
Further, in the present invention, the wireless communication terminal is a communication portable terminal such as a mobile phone, a PHS, a PDA with a wireless communication function, and a personal computer with a wireless communication function. In this case, it is possible to detect the position of a person holding such a mobile terminal.
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0038]
[First Embodiment]
FIG. 3 shows the configuration and operation of the position detection system according to the first embodiment of the present invention.
[0039]
The position detection system shown in FIG. 1 includes a radio communication terminal 1 that transmits radio waves, at least three or more base stations 2 that receive radio waves from the radio communication terminal 1 and measures the intensity thereof, and It has an information server 3 that calculates the distance between the wireless communication terminal 1 and each base station 2 based on the measured received signal strength data and manages the position information of the wireless communication terminal 1.
[0040]
In this system, the wireless communication terminal 1 transmits a radio wave during a detection operation. Each base station 2 receives a radio wave from the wireless communication terminal 1, measures the received signal strength, and transmits the result to the information server 3.
[0041]
The information server 3 uses the received signal strength data ra ′ [t], rb ′ [t], and rc ′ [t] at the sampling time [t] received by each base station 2 to connect the wireless communication terminal 1 to the base station 2. The distance between the wireless communication terminals 1 is determined, and the location p ′ [t] of the wireless communication terminal 1 is estimated in relation to the location of each base station 2 (step 101).
[0042]
In this case, the environment around the base station 2 is not uniform. For example, various features such as trees and buildings exist outdoors and walls and doors exist indoors. Are generally not concentric with the base station. For this reason, mapping is performed by actual measurement, or an approximate value or a table indicating the relationship between the received signal strength and the distance is adaptively created based on values measured at several points and stored in the information server 3. The distance is determined from the received signal strength.
[0043]
Further, the information server 3 predicts the change of the moving speed, the moving direction, and the received signal strength of the wireless communication terminal 1 from the past position of the wireless communication terminal 1 and the past history of the received signal strength. Relative probability distribution {p ″ [t]} of the existing position p ″ [t], and the received signal intensity ra ″ [t], rb ″ [t], rc ″ [t] , A relative probability distribution {ra "[t]}, {rb" [t]}, {rc "[t]} is obtained (step 102). For example, in FIG. 3, the past position p of the wireless communication terminal 1 at the sampling times [t-3], [t-2], and [t-1] is recorded as the history of the existing position of the wireless communication terminal 1 and the received signal strength. [T-3], p [t-2], p [t-1], past received signal strength at the base station 2a at sampling times [t-3], [t-2], [t-1] Past received signals at the base station 2b at ra [t-3], ra [t-2], ra [t-1], and sampling times [t-3], [t-2], [t-1] Past reception at the base station 2c at the intensity rb [t-3], rb [t-2], rb [t-1], and sampling time [t-3], [t-2], [t-1] The signal strengths rc [t-3], rc [t-2] and rc [t-1] are determined.
[0044]
Finally, the presence position p ′ [t] determined in step 101 and the received signal strengths ra ′ [t], rb ′ [t], and rc ′ [t] are estimated presence positions p ″ determined in step 102. [T] relative probability distribution {p ″ [t]} and received signal strength ra ″ [t], rb ″ [t], rc ″ [t] relative probability distribution ra ″ Relative probability distributions of [t], rb "[t], rc" [t] {ra "[t]}, {rb" [t]}, {rc "[t]} Weighting is performed to determine a final existence position p [t] and received signal strengths ra [t], rb [t], and rc [t] (step 103).
[0045]
For example, in FIG. 3, the final existence position p [t] is obtained from the relative probability distribution {p ″ [t]} of the measured existence position p ′ [t] and the predicted existence position p ″ [t]. ]. Let the coordinates of p ′ [t] be the relative probability distribution {p ″ [t]} of (x ′ [t], y ′ [t], z ′ [t], p ″ [t]) , The coordinates of p0 ″ [t] having the highest relative existence probability (becoming 100%) are (x0 ″ [t], y0 ″ [t], z0 ″ [t]), When the relative existence probability of the position of p ′ [t] is 10%, the coordinates (x [t], y [t], z [t]) of p [t] are, for example,
x = (100 × 0 ″ + 10 × ′) / 110
y = (100y0 ″ + 10y ′) / 110 (1)
z = (100z0 ″ + 10z ′) / 110
And can be obtained by weighting.
[0046]
Similarly, the measured received signal strengths ra ′ [t], rb ′ [t], rc ′ [t] and the predicted received signal strengths ra ″ [t], rb ″ [t], rc ″ [ t], the final received signal strengths ra [t], rb [t] from the relative probability distributions {ra "[t]}, {rb" [t]}, {rc "[t]}. , Rc [t]. relative probability distributions of ra ″ [t], rb ″ [t], rc ″ [t] {ra ″ [t]}, {rb ″ [t]}, {rc ″ [t ], The received signal strength at which the relative existence probability becomes the highest (100%) is defined as ra0 "[t], rb0" [t], rc0 "[t], and the measured received signal When the relative existence probabilities of the intensities ra '[t], rb' [t], and rc '[t] are each 10%, the received signal intensities ra [t], rb [t], and rc [t] Is, for example,
ra = (100ra0 ″ + 10ra ′) / 110
rb = (100rb0 ″ + 10rb ′) / 110 (2)
rc = (100rc0 ″ + 10rc ′) / 110
And can be obtained by weighting.
[0047]
In this case, for example, an estimated position generated when the received signal strength fluctuates due to the influence of the environment around the wireless communication terminal 1 such as a temporary shield between the wireless communication terminal 1 and the base station 2. Irrational movement can be suppressed, and the estimated position can be kept within a reasonable range predicted from the past moving speed, moving direction, and received signal strength.
[0048]
In the first embodiment, the radio communication terminal 1 transmits radio waves, the base station 2 receives radio waves from the radio communication terminal 1 and measures the intensity, and the information server 3 The distance between the wireless communication terminal 1 and each base station 2 is obtained from the measured received signal strength data to manage the position information of the wireless communication terminal 1. However, the base station 2 transmits radio waves. The wireless communication terminal 1 receives a radio wave from the base station 2 and measures its strength, transmits the result to the base station 2, and the information server 3 performs wireless communication based on the received signal strength data measured by the wireless communication terminal 1. The configuration may be such that the distance between the communication terminal 1 and each base station 2 is obtained, and the position information of the wireless communication terminal 1 is managed.
[0049]
The above positioning may be performed only when the wireless communication terminal 1 moves. In this case, for example, when the wireless communication terminal 1 is not moving, there is no need to update the position information managed by the information server 3, and the load of processing the position information and the data amount can be reduced.
[0050]
Further, a vibration sensor may be used as means for detecting the movement of the wireless communication terminal 1. In this case, for example, when the person holding the wireless communication terminal 1 is walking, the movement can be easily detected.
[0051]
FIG. 4 is a diagram illustrating a configuration example for detecting movement of a wireless communication terminal using the vibration sensor according to the first embodiment of the present invention.
[0052]
This can be realized by providing the wireless communication terminal 1 with the vibration sensor 13 using the inverted pendulum 14. The holding circuit 15 has a function of turning on the power supply 17 of the wireless communication terminal 1 for a short time only when the electrodes 14a and 14b are in contact (or when they are separated), and perform intermittent transmission. Thereby, the radio wave can be transmitted only when the wireless communication terminal 1 moves.
[0053]
In addition, an electromagnetic wave, a sound wave, light, or a combination thereof may be used as the wireless communication medium. In this case, even in the same environment, the propagation status differs depending on the medium. Therefore, by comparing these, the positioning accuracy can be improved.
[0054]
Further, the wireless communication terminal 1 may have a function of receiving a transmission radio wave from a GPS satellite, and may be used together with the detection of an existing position outdoors. In this case, the accuracy of positioning outdoors can be improved.
[0055]
Further, a wireless tag that transmits a unique sign number may be used as the wireless communication terminal 1. In this case, when such a wireless tag is attached to an article or the like, the position of the article can be detected.
[0056]
Further, as the wireless communication terminal 1, a communication mobile terminal such as a mobile phone, a PHS, a PDA with a wireless communication function, or a personal computer with a wireless communication function may be used. In this case, it is possible to detect the position of a person holding such a mobile terminal.
[0057]
[Second embodiment]
FIG. 5 is a diagram showing the configuration and operation of the position detection system according to the second embodiment of the present invention.
[0058]
The position detection system shown in FIG. 1 includes at least three or more base stations 2 that transmit radio waves, and a wireless communication terminal 1 that receives radio waves from the base station 2 and measures the intensity.
[0059]
The wireless communication terminal 1 obtains the distance between the wireless communication terminal 1 and each base station 2 based on the received signal strength data measured by the wireless communication terminal 1, and sends an information server 3 that manages the position of the wireless communication terminal 1 Have.
[0060]
In this system, the base station 2 transmits a radio wave during the detection operation. The wireless communication terminal 1 receives a radio wave from each base station 2, measures the received signal strength, and stores the result in the information server 3.
[0061]
The information server 3 uses the received signal strength data ra ′ [t], rb ′ [t], and rc ′ [t] at the sampling time [t] received by the wireless communication terminal 1 to communicate between the wireless communication terminal 1 and the base station 2. The distance between the base stations 2 is determined, and the location p ′ [t] of the wireless communication terminal 1 is estimated based on the relationship with the location of each base station 2 (step 201).
[0062]
In this case, the environment around the base station 2 is not uniform. For example, various features such as trees and buildings exist outdoors, and walls and doors exist indoors. Are generally not concentric with the base station. Therefore, an approximate expression or a table showing the relationship between the received signal strength and the distance is adaptively created and stored in the information server 3 by performing mapping by actual measurement or based on values measured at several points. The distance is determined from the received signal strength.
[0063]
Further, the information server 3 predicts the change of the moving speed, the moving direction, and the received signal strength of the wireless communication terminal 1 from the past position of the wireless communication terminal 1 and the past history of the received signal strength. Relative probability distribution {p ″ [t]} of the existing position p ″ [t], and the received signal intensity ra ″ [t], rb ″ [t], rc ″ [t] , A relative probability distribution {ra "[t]}, {rb" [t]}, {rc "[t]} is obtained (step 202). For example, in FIG. 5, the past history of the existence position of the wireless communication terminal 1 and the received signal strength indicates the past history of the wireless communication terminal 1 at the sampling times [t-3], [t-2], and [t-1]. Past reception from base station 2a at positions p [t-3], p [t-2], p [t-1], and sampling times [t-3], [t-2], [t-1] Past reception from the base station 2b at signal intensities ra [t-3], ra [t-2], ra [t-1] and sampling times [t-3], [t-2], [t-1] Past reception from the base station 2c at signal strengths rb [t-3], rb [t-2], rb [t-1] and sampling times [t-3], [t-2], [t-1] The signal strengths rc [t-3], rc [t-2] and rc [t-1] are determined.
[0064]
Finally, the presence position p ″ [t] determined in step 201 and the received signal strengths ra ′ [t], rb ′ [t], and rc ′ [t] are estimated presence positions p ′ determined in step 202. '[T] relative probability distribution {p ″ [t]} and received signal strength ra ″ [t], rb ″ [t], rc ″ [t] relative probability distribution {ra ”[T]}, {rb” [t]}, {rc ”[t]}, weight the final location p [t] and received signal strength ra [t], rb [t] , Rc [t] are determined (step 203).
[0065]
For example, in FIG. 3, the final existence position p [t] is obtained from the relative probability distribution {p ″ [t]} of the measured existence position p ′ [t] and the predicted existence position p ″ [t]. ]. Let the coordinates of p ′ [t] be (x ′ [t], y ′ [t], z ′ [t]) and the relative probability distribution {p ″ [t]} of p ″ [t] The coordinates of p0 ″ [t] with the highest relative probability (100%) are (x0 ″ [t], y0 ″ [t], z0 ″ [t]), and p 'If the relative existence probability of the position [[t] is 10%, the coordinates (x [t], y [t], z [t]) of p [t] are, for example,
x = (100 × 0 ″ + 10 × ′) / 110
y = (100y0 ″ + 10y ′) / 110 (3)
z = (100z0 ″ + 10z ′) / 110
And can be obtained by weighting.
[0066]
Similarly, the measured received signal strengths ra ′ [t], rb ′ [t], and rc ′ [t], and the predicted received signal strengths ra ″ [t], rb ″ [t], and rc ″ [ t], the final received signal strengths ra [t], rb [t] from the relative probability distributions {ra "[t]}, {rb" [t]}, {rc "[t]}. , Rc [t]. relative probability distributions of ra ″ [t], rb ″ [t], rc ″ [t] {ra ″ [t]}, {rb ″ [t]}, {rc ″ [t ], The received signal strength at which the relative existence probability is the highest (100%) is defined as ra0 "[t], rb0" [t], rc0 "[t], and the measured received signal If the relative existence probabilities of the intensities ra '[t], rb' [t], and rc '[t] are each 10%, the received signal intensities ra [t], rb [t], and rc [t] Is, for example,
ra = (100ra0 ″ + 10ra ′) / 110
rb = (100rb0 ″ + 10rb ′) / 110 (4)
rc = (100rc0 ″ + 10rc ′) / 110
And can be obtained by weighting.
[0067]
In this case, for example, the estimated position of the estimated position caused when the received signal strength fluctuates due to the influence of the environment around the wireless communication terminal 1 such as a temporary shield between the wireless communication terminal 1 and the base station 2. Irrational movement can be suppressed, and the estimated position can be kept within a reasonable range predicted from the past moving speed, moving direction, and received signal strength.
[0068]
In the second embodiment, the base station 2 transmits radio waves, the radio communication terminal 1 receives radio waves from the base station 2 and measures the intensity thereof. The distance between the wireless communication terminal 1 and each base station 2 is obtained from the measured received signal strength data to manage the position information of the wireless communication terminal 1, but the wireless communication terminal 1 transmits radio waves. Then, the base station 2 receives the radio wave from the wireless communication terminal 1 and measures its intensity, transmits the result to the wireless communication terminal 1, and the information server 3 transmits the received signal strength data measured by the wireless communication terminal 1. The distance between the wireless communication terminal 1 and each of the base stations 2 may be obtained by using the above method, and the position information of the wireless communication terminal 1 may be managed.
[0069]
[Third Embodiment]
FIG. 6 is a diagram showing the configuration and operation of the position detection system according to the third embodiment of the present invention.
[0070]
The position detection system shown in FIG. 1 includes a radio communication terminal 1 that transmits radio waves, at least three or more base stations 2 that receive radio waves from the radio communication terminal 1 and measures the intensity thereof, and It has an information server 3 that calculates the distance between the wireless communication terminal 1 and each base station 2 based on the measured received signal strength data and manages the position information of the wireless communication terminal 1. In this system, the wireless communication terminal 1 transmits a radio wave during a detection operation. Each base station 2 receives a radio wave from the wireless communication terminal 1, measures the received signal strength, and transmits the result to the information server 3.
[0071]
The information server 3 uses the received signal strength data ra ′ [t], rb ′ [t], and rc ′ [t] at the sampling time [t] received by each base station 2 to connect the wireless communication terminal 1 to the base station 2. The distance between the wireless communication terminals 1 is determined, and the location p ′ [t] of the wireless communication terminal 1 is estimated in relation to the location of each base station 2 (step 301).
[0072]
In this case, the environment around the base station 2 is not uniform. For example, various features such as trees and buildings exist outdoors, and walls and doors exist indoors. Contour lines generally do not form concentric circles around the base station. For this reason, mapping is performed by actual measurement, or an approximate expression or table showing the relationship between the received signal strength and the distance is adaptively created based on values measured at several points and stored in the information server 3. In advance, the distance is obtained from the received signal strength.
[0073]
Further, the information server 3 refers to the past positions of a plurality of wireless communication terminals located in the wireless zone of the base station 2 and the past history of the received signal strength, and outdoors, such as a roadway, a sidewalk, a track, a building, a station, and the like. In a room, the relative probability distribution ｛p ′ of the predicted position p ″ [t] of the wireless communication terminal 1 with respect to the direction and the area with respect to the place where the wireless communication terminal rationally exists, such as a corridor or a desk. Relative probability distribution {ra '' [t]}, {rb 'of received signal strengths ra "[t], rb" [t], rc "[t] predicted as" [t]} '[T]}, {rc''[t]} are obtained (step 302).
[0074]
For example, in FIG. 6, although the pond 5, the road 6, the building 7, and the parking space 8 are displayed, the past flow of the person carrying the wireless communication terminal is grasped, and, for example, the wireless communication terminal 1 is carried. The dotted line indicates that the probability of the person going to the pond 5 is small, the probability of going to the entrance of the building 7 is large, and the probability of going to the entrance of the parking space 8 is large.
[0075]
Finally, the existence position p ′ [t] obtained in step 301 and the received signal strengths ra ′ [t], rb ′ [t], and rc ′ [t] are predicted existence positions p ″ obtained in step 302. Relative probability distribution {p ″ [t]} of [t] and relative probability distribution {ra ′ of received signal strengths ra ″ [t], rb ″ [t], rc ″ [t] {[T]}, {rb "[t]}, {rc" [t]}, the final existence position p [t] and the received signal strength ra [t], rb [t], rc [t] is determined (step 303).
[0076]
For example, in FIG. 6, the final existence position p [t] is obtained from the relative probability distribution {p ″ [t]} of the measured existence position p ′ [t] and the predicted existence position p ″ [t]. ]. Let the coordinates of p ′ [t] be (x ′ [t], y ′ [t], z ′ [t]) and the relative probability distribution {p ″ [t]} of p ″ [t] , The coordinates of p0 ″ [t] having the highest relative existence probability (becoming 100%) are (x0 ″ [t], y0 ″ [t], z0 ″ [t]), When the relative existence probability of the position of p ′ [t] is 10%, the coordinates (x [t], y [t], z [t]) of p [t] are, for example,
x = (100 × 0 ″ + 10 × ′) / 110
y = (100y0 ″ + 10y ′) / 110 (5)
z = (100z0 ″ + 10z ′) / 110
And can be obtained by weighting.
[0077]
Similarly, the measured received signal strengths ra ′ [t], rb ′ [t], and rc ′ [t], and the predicted received signal strengths ra ″ [t], rb ″ [t], and rc ″ [ t], the final received signal strengths ra [t], rb [t] from the relative probability distributions {ra "[t]}, {rb" [t]}, {rc "[t]}. , Rc [t]. relative probability distributions of ra ″ [t], rb ″ [t], rc ″ [t] {ra ″ [t]}, {rb ″ [t]}, {rc ″ [t ], The received signal strength at which the relative existence probability is the highest (100%) is defined as ra0 "[t], rb0" [t], rc0 "[t], and the measured received signal If the relative existence probabilities of the intensities ra '[t], rb' [t], and rc '[t] are each 10%, the received signal intensities ra [t], rb [t], and rc [t] Is, for example,
ra = (100ra0 ″ + 10ra ′) / 110
rb = (100rb0 ″ + 10rb ′) / 110 (6)
rc = (100rc0 ″ + 10rc ′) / 110
And can be obtained by weighting.
[0078]
In this case, for example, even though the wireless communication terminal 1 is moving as fast as a car, the estimated position suddenly deviates from a roadway or a track, or the estimated position suddenly moves from a roadway to a track, Irrational predictions can be avoided.
[0079]
The embodiments described above are all illustrative of the present invention and not restrictive, and the present invention can be embodied in other various modifications and alterations. Therefore, the scope of the present invention should be defined only by the appended claims and their equivalents.
[0080]
【The invention's effect】
As described above, according to the present invention, in a conventional position detection system, for example, when a temporary obstruction occurs between a broadcasting station and a base station, the received signal strength depends on the environment around the transmitting station. Can solve the problem that it is not possible to estimate an accurate position when the position changes, and realize a position detection system that can estimate the position of the wireless communication terminal with high accuracy.
[0081]
More specifically, according to the present invention, in the position detection system, at the time of positioning, the change in the moving speed and the received signal strength of the wireless communication terminal is predicted from the existing position of the wireless communication terminal and the past history of the received signal strength. The present invention is characterized in that a relative probability distribution between a predicted location of a communication terminal and a received signal strength is obtained and weighted. In this case, for example, when the reception signal strength fluctuates due to the influence of the surrounding environment of the wireless communication terminal, such as when a temporary obstacle occurs between the wireless communication terminal and the base station, the estimated position is unreasonable. And the estimated position can be kept within a reasonable range predicted from the past moving speed, moving direction, and received signal strength.
[0082]
Further, according to the present invention, the moving speed and moving direction of the wireless communication terminal are determined from the existing positions of the plurality of wireless communication terminals in the wireless zone of the base station and the past history of the received signal strength at the base station and the wireless communication terminal. And the change in the received signal strength, and the relative probability distribution of the predicted location of the wireless communication terminal and the received signal strength is obtained.Equivalently, indoors such as roadways, sidewalks, roads, buildings, stations, etc. In, by weighting the directions and areas for places where wireless communication terminals such as corridors and desks rationally exist, for example, despite the fact that the wireless communication terminals are moving at the same speed as cars, Irrelevant predictions, such as when the estimated position suddenly deviates from the roadway or the track or when the estimated position suddenly moves from the roadway to the track, can be avoided.
[0083]
Further, according to the present invention, it is necessary to update the position information managed by the information server, for example, when the wireless communication terminal is not moving, by performing positioning only when the wireless communication terminal moves. As a result, the load of processing the position information and the amount of data can be reduced.
[0084]
Further, according to the present invention, by using a vibration sensor as a means for detecting the movement of the wireless communication terminal, for example, when the person holding the wireless communication terminal is walking, the movement can be easily detected. Can be.
[0085]
Further, according to the present invention, the use of electromagnetic waves, sound waves, light, or a combination thereof as a wireless communication medium allows propagation conditions to differ depending on the medium even under the same environment. Can be increased.
[0086]
Further, according to the present invention, by changing the directivity of electromagnetic waves, sound waves, light, and the like used for wireless communication, the direction of the wireless communication terminal as viewed from the base station can be narrowed, and the accuracy of positioning can be increased. .
[0087]
Further, according to the present invention, the wireless communication terminal has means for receiving a transmission radio wave from a GPS satellite, and is used together with the detection of an existing position outdoors, thereby improving the accuracy of positioning outdoors.
[0088]
Further, according to the present invention, a mobile communication terminal such as a mobile phone, a PHS, a PDA with a wireless communication function, or a personal computer with a wireless communication function is used as a wireless communication terminal, thereby having such a mobile terminal. The position of a person can be detected.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining the principle of the present invention.
FIG. 2 is a principle configuration diagram of the present invention.
FIG. 3 is a diagram showing the configuration and operation of the position detection system according to the first embodiment of the present invention.
FIG. 4 is a diagram illustrating a configuration example for detecting movement of a wireless communication terminal using a vibration sensor according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a configuration and operation of a position detection system according to a second embodiment of the present invention.
FIG. 6 is a diagram illustrating the configuration and operation of a position detection system according to a third embodiment of the present invention.
FIG. 7 is a diagram showing a configuration of a conventional position detection system.
FIG. 8 is a diagram illustrating a case where a shield 134 is generated between a base station 132b and a transmitting station 131.
[Explanation of symbols]
1 wireless communication terminal
2 base stations
3 information server
5 pond
6 road
7 Building
8 parking spaces
13 Vibration sensor
14 Inverted pendulum
14a, 14b electrode
15 Holding circuit
17 Power supply
21 Receiving means
22 Strength transmission means
31 Strength receiving means
32 Position detecting means
131 transmitting station
132a, 132b, 132 base station
133 center station
134 Shield

Claims

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection method in a system comprising:
The base station comprises:
Receiving wireless signals transmitted from the wireless communication terminal,
Measure the received signal strength of the received signal, send to the information server,
The information server comprises:
Receiving the received signal strength from the base station,
Using the received signal strength, obtaining a range where the wireless communication terminal can exist corresponding to each received signal strength, and detecting an existing position of the wireless communication terminal from an overlap of the ranges. .

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection method in a system comprising:
The base station comprises:
Transmitting a wireless signal to the wireless communication terminal,
The wireless communication terminal,
Receiving the wireless signal from the base station;
Measuring the received signal strength of the radio signal,
In the information server in the own terminal, using the received signal strength, find a range in which the own terminal can exist corresponding to each received signal strength, detecting the location of the own terminal from the overlap of each range, Position detection method.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection method in a system comprising:
The wireless communication terminal,
Transmitting a radio signal to the base station;
The base station comprises:
Receiving each of the wireless signals transmitted from the wireless communication terminal,
Measuring the received signal strength of the received signal, transmitting to the wireless communication terminal,
The wireless communication terminal,
Receiving the received signal strength transmitted from the plurality of base stations,
In the information server in own terminal,
A position detection method comprising: obtaining a range in which the own terminal can exist corresponding to each received signal strength using the received received signal strength; and detecting an existing position of the own terminal from an overlap of the ranges.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection method in a system comprising:
The base station comprises:
Transmitting a wireless signal to the wireless communication terminal,
The wireless communication terminal,
Receiving the radio signal transmitted from the base station, measuring the received signal strength, transmitting to the base station,
The base station comprises:
Transmitting the received signal strength received from the wireless communication terminal to the information server,
The information server comprises:
Using the received signal strength received from the base station, find a range where the wireless communication terminal can exist corresponding to each received signal strength, and detect the location of the own terminal from the overlap of each range, Position detection method.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection system,
The base station comprises:
Receiving means for receiving wireless signals transmitted from the wireless communication terminal,
Measuring the received signal strength of the received signal, and strength transmitting means for transmitting to the information server,
The information server comprises:
Strength receiving means for receiving the received signal strength from the base station,
Position detection means for obtaining a range where the wireless communication terminal corresponding to each received signal strength can exist, using the received signal strength, and detecting an existing position of the wireless communication terminal from an overlap of each range. A position detection system characterized by the following.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection system,
The base station comprises:
Having transmission means for transmitting a radio signal to the radio communication terminal,
The wireless communication terminal includes the information server,
It measures the received signal strength of the received wireless signal, and has a received strength measuring means to pass to the information server,
The information server comprises:
Using the received signal strength, a range in which the own terminal can exist corresponding to each received signal strength is obtained, and position detecting means for detecting an existing position of the own terminal from an overlap of the respective ranges is provided. system.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least receiving means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection system,
The base station comprises:
Receiving means for receiving a wireless signal transmitted from the wireless communication terminal;
Measuring the received signal strength of the received signal, and strength transmitting means for transmitting to the wireless communication terminal,
The wireless communication terminal includes the information server,
And strength receiving means for receiving the received signal strength transmitted from the plurality of base stations,
The information server comprises:
Using the received received signal strength, a range in which the own terminal can exist corresponding to each received signal strength is obtained, and a position detecting unit that detects an existing position of the own terminal from an overlap of each range is provided. Position detection system.

A plurality of base stations connected to the communication network, a plurality of wireless communication terminals having at least transmitting means as mobile stations wirelessly connected to the base stations, and information including position information of the wireless communication terminals is managed. An information server and a position detection system,
The base station comprises:
Transmitting means for transmitting a wireless signal to the wireless communication terminal,
A first intensity transmitting unit that transmits a received signal intensity received from the wireless communication terminal to the information server,
The wireless communication terminal,
A second strength transmitting unit that receives the wireless signal transmitted from the base station, measures a received signal strength, and transmits the signal to the base station;
The information server comprises:
Using the received signal strength received from the base station, a range in which the wireless communication terminal can exist corresponding to each received signal strength is obtained, and a position detection for detecting the presence position of the wireless communication terminal from the overlap of each range. A position detection system comprising means.

The position detecting means,
First prediction means for predicting a change in the moving speed, moving direction, and received signal strength of the wireless communication terminal from the existing position of the wireless communication terminal and the past history of the received signal strength;
The position detection system according to any one of claims 5 to 8, further comprising a first weighting unit that obtains a relative probability distribution between a predicted existence position of the wireless communication terminal and the received signal strength and performs weighting.

The position detecting means,
A second estimating a moving speed, a moving direction, and a change in the received signal strength of the wireless communication terminal from the existing positions of the plurality of wireless communication terminals in the wireless zone of the base station and the past history of the received signal strength; Forecasting means;
Obtain the relative probability distribution of the predicted location of the wireless communication terminal and the received signal strength, and weight the directions and areas relative to the place where the wireless communication terminal is rationally located indoors and outdoors. 10. The position detecting system according to claim 5, further comprising a second weighting means for performing the operation.

The wireless communication terminal,
Movement detecting means for detecting that the wireless communication terminal has moved,
The position detection system according to any one of claims 5 to 10, further comprising means for performing positioning only when the wireless communication terminal moves by the movement detection means.

The movement detection means,
The position detection system according to claim 11, wherein a vibration sensor is used.

The position detection system according to any one of claims 5 to 12, wherein an electromagnetic wave, a sound wave, or light, or a combination thereof is used as a wireless communication medium for wireless communication.

14. The position detection system according to claim 5, wherein the directivity of electromagnetic waves, sound waves, and light used for wireless communication is changed.

The wireless communication terminal,
The position detection system according to any one of claims 5 to 9, further comprising means for receiving a transmission radio wave from a GPS satellite, wherein the position detection system is used in combination with detection of a presence position outdoors.

The wireless communication terminal,
The position detection system according to any one of claims 5 to 15, wherein the position detection system is a wireless tag that transmits a unique sign number.

The wireless communication terminal,
The position detection system according to any one of claims 5 to 15, which is a communication portable device including a mobile phone, a PHS, a PDA with a wireless communication function, and a personal computer with a wireless communication function.

A wireless communication terminal having at least a receiving unit as a mobile station wirelessly connected to a plurality of base stations connected to a communication network,
An information server that manages information including location information of its own terminal,
Strength receiving means for receiving the received signal strength transmitted from the plurality of base stations,
The information server comprises:
Using the received received signal strength, a range in which the own terminal can exist corresponding to each received signal strength is obtained, and a position detecting unit that detects an existing position of the own terminal from an overlap of each range is provided. Wireless communication terminal.

A wireless communication terminal having at least a receiving unit as a mobile station wirelessly connected to a plurality of base stations connected to a communication network,
An information server that manages information including location information of its own terminal,
Received radio signals transmitted from the plurality of base stations, and received signal measurement means for measuring the received signal strength of the radio signal,
The information server comprises:
Wireless communication characterized by having a position detecting means for obtaining a range where the own terminal can exist corresponding to each received signal strength by using the received signal strength, and detecting an existing position of the own terminal from an overlap of each range. Terminal.