JP4200649B2

JP4200649B2 - Automatic guided vehicle position detection device

Info

Publication number: JP4200649B2
Application number: JP2000307078A
Authority: JP
Inventors: 昌文市原
Original assignee: Meidensha Corp
Current assignee: Meidensha Corp
Priority date: 2000-10-06
Filing date: 2000-10-06
Publication date: 2008-12-24
Anticipated expiration: 2020-10-06
Also published as: JP2002116023A

Description

【０００１】
【発明の属する技術分野】
本発明は無人搬送車の誘導に用いて有用な、無人搬送車の位置検出装置に関する。
【０００２】
【従来の技術】
［光テープ誘導方法］
従来、無人搬送車の誘導方法として、光反射率の良いテープ（以下、光テープと呼ぶ）を無人搬送車が走行する床面に貼り付けておき、無人搬送車から床面に光を照射してその反射光から光テープを検出することにより、光テープのルート上に無人搬送車を走行させるという光テープ誘導方法が一般的である。しかし、光テープ誘導方法では、光テープが車輪に踏まれるなど、汚れによって光テープの反射率が低下すると、無人搬送車が光テープを検出できなくなることがあるため、光テープのメンテナンスが必要である。
【０００３】
［反射板を用いた位置検出に基づく誘導方法］
光テープ誘導方法の問題点を解決するために、無人搬送車の走行環境の複数個所に反射板を立設しておき、無人搬送車から光（通常、レーザ）を回転走査して反射板の方向を検出することにより、自車の位置を検出して走行するという誘導方法が検討されている。
【０００４】
［反射板を用いた位置検出方法］
以下、図８〜図１３を参照して、反射板を用いた位置検出方法を説明する。図８は反射板を用いた位置検出に基づく誘導方式を説明する図であり、図９は反射板の有無と反射レーザの関係を示し、図１０は無人搬送車から見た反射板方向を示し、図１１は反射板方向検出結果の例を示し、図１２は反射板分布地図の例を示し、図１３は反射板分布地図上での無人搬送車の位置と進行方向の検索結果を示す。
【０００５】
図８に示すように、無人搬送車１の移動エリア２周囲の複数個所（図では３個所）に反射板２８₁、２８₂、２８₃が立てられている。各反射板とも、反射エリアには非反射部は形成されていない。無人搬送車１には位置検出装置４が搭載されている。
【０００６】
従来は、位置検出装置からレーザ５を水平方向のみ３６０°全方向に照射し、その反射の有無から各反射板方向を検出し、反射板方向検出結果と、各反射板２８₁、２８₂、２８₃の既知の位置情報から、無人搬送車１の位置を検出するようになっている。
【０００７】
即ち、図９に示すように、レーザ５が反射板の存在する方向へ照射された場合は強く反射され、反射レーザ６となって位置検出装置に戻ってくるが、反射板が無い方向へ照射された場合は戻ってこない。そして、反射レーザ６を検出したときのレーザ５の照射方向が反射板方向であるので、反射レーザ６を検出したときのレーザ照射方向を調べることにより、反射板方向を検出するこができる。
【０００８】
図１０に示すように、無人搬送車１から見た各反射板方向７₁、７₂、７₃は、無人搬送車１の進行方向８を基準にした角度θ₁、θ₂、θ₃として検出される。つまり、図１１に示すように、無人搬送車１から見てどの方向（角度θ₁、θ₂、θ₃）に反射板が存在しているかという反射板方向検出結果９が得られる。
【０００９】
そこで、位置検出装置に予め各反射板２８₁、２８₂、２８₃の位置情報を記憶しておくことにより、反射板方向検出結果９と既知の反射板位置情報とを対応させることにより、無人搬送車１の位置と進行方向を知ることができる。
【００１０】
反射板位置情報として、図１２に示すような反射板分布地図１０が記憶される場合を考えて見る。
【００１１】
この場合、図１３に示すように、反射板分布地図１０上に、或る位置１１とそれを起点とする或る方向１２を設定する。そして、この位置１１から見た各反射板２８₁、２８₂、２８₃の方向１３₁、１３₂、１３₃と位置１１を起点とする方向１２とがなす角度が反射板方向検出結果（θ₁、θ₂、θ₃）９と良く一致すれば、位置１１に無人搬送車１が存在し、方向１２が無人搬送車１の進行方向であるといえる。そこで、反射板方向検出結果（θ₁、θ₂、θ₃）９と良く一致する位置１１と方向１２を反射板分布地図１０上で検索することにより、無人搬送車１の位置と進行方向を検出することができる。
【００１２】
次に、図１４〜図１５を参照して、位置検出装置の従来例を説明する。図１４は位置検出装置の従来構成を示し、図１５は反射鏡回転角度と、受光出力と、反射光有無との関係を示す。
【００１３】
従来の位置検出装置は、図１４に示すように、メモリ１４と、回転装置１５と、反射鏡１６と、回転角検出装置１９と、光照射・受光装置２０と、反射光有無検出装置２１と、反射板方向検出装置２９と、位置演算装置３０を備える。
【００１４】
メモリ１４には予め、全ての反射板２８_1,２８_2,２８₃の位置情報として、反射板分布地図１０が記録されている。
【００１５】
回転装置１５は車体水平面内で回転できるステージ１５ａと、ステージ１５ａを回転駆動するモータ１５ｂからなる。
【００１６】
反射鏡１６はその傾斜角度を４５度に固定して、ステージ１５ａに上方を向いた状態で固定されている。
【００１７】
回転角検出装置１９はモータ１５ｂの回転角度を検出することにより、反射鏡１６の回転角度を表す反射鏡回転角検出結果１９ａを出力する。反射鏡１６の回転角度の基準は通常、無人搬送車１の進行方向８である。
【００１８】
光照射・受光装置２０はレーザの照射機能及び受光機能を有しており、反射鏡１６の真上に、車体垂直方向下向きに設置されている。
【００１９】
従って、光照射・受光装置２０がレーザ５を照射すると、このレーザ５は反射鏡１６に入射して反射され、反射鏡１６の回転に応じて水平面内でのみ３６０度全方向に回転走査される。
【００２０】
一方、いずれかの反射板で反射されたレーザ（反射レーザ）６は反射鏡１６に入射して車体垂直方向上向きに反射され、光照射・受光装置２０により受光される。光照射・受光装置２０は受光した反射レーザ６の光量を表す受光出力２０ａを出力する。
【００２１】
反射光有無検出装置２１は光照射・受光装置２０の受光出力２０ａから反射レーザ６の有無を検出して、反射光有無検出結果２１ａを出力する。
【００２２】
ここで、光照射・受光装置２０の受光出力２０ａと、反射光有無検出装置２１の反射光有無検出結果２１ａと、回転角検出装置１９の反射鏡回転角検出結果１９ａとの関係は、図１５に示すようになる。
【００２３】
図１５（ａ）は横軸に反射鏡回転角度、縦軸に受光出力をとったグラフを示し、図１５（ｂ）は横軸に反射鏡回転角度、縦軸に反射レーザの有無をとったグラフを示す。反射レーザ６が有った時の反射鏡回転角度θ₁、θ₂、θ₃が反射板方向を表す。
【００２４】
反射板方向検出装置２９は、反射光有無検出結果２１ａと、反射鏡回転角検出結果１９ａに基づいて、図１５（ｂ）に示したような、横軸に反射鏡回転角度、縦軸に反射レーザの有無をとったグラフを作成することにより、どの方向から反射レーザ６が来ているかを判断して反射板方向を検出し、反射板方向検出結果９を出力する。
【００２５】
位置演算装置３０は、反射板方向検出装置２９の反射板方向検出結果９と、メモリ１４に記憶された反射板分布地図１０等の反射板位置情報に基づいて、これらの対応関係から無人搬送車１の位置１１と進行方向１２を求める。
【００２６】
【発明が解決しようとする課題】
上述した反射板と光（レーザ）を用いた位置検出方法は、反射板方向だけを測定すれば良いので、光照射・受光装置２０等が安価にできるという利点がある。しかし、下記問題点もある。
(1) 反射鏡１６の傾斜角度が４５°固定であるので、無人搬送車１が傾いてレーザ５の照射平面が反射板２８₁、２８₂、２８₃からずれてしまうと、反射板方向が検出できなくなり、無人搬送車１の位置決定に必要な情報が不足する。
(2) 反射レーザ６がどの反射板２８₁、２８₂、２８₃から反射してきたものであるかという情報は検出されない。また、無人搬送車１から反射板までの距離も検出されない。そのため、反射板２８₁、２８₂、２８₃の設置分布を工夫して、無人搬送車１の位置を誤検出しないようにする必要がある。
【００２７】
本発明の課題は、上記従来技術の問題点を解決する無人搬送車の位置検出装置を提供することにある。
【００２８】
【課題を解決するための手段】
請求項１に係る発明は無人搬送車の位置検出装置であり、無人搬送車の走行環境の複数個所に立設され、互いに異なるパターンで縦方向に区分して形成された反射部と非反射部を有する反射板の位置情報、及び、反射部と非反射部のパターン情報を予め記憶した記憶装置と、反射鏡と、前記反射鏡を回転させる回転装置と、前記反射鏡を傾斜した状態で支持し、かつ、その傾斜角度が遠心力により変化するように支持する反射鏡支持装置と、前記反射板の回転速度を変化させる速度変更装置と、下向きに設置され、前記反射鏡に対する光の照射及び反射鏡からの光の受光を行う光照射・受光装置と、前記光照射・受光装置の受光出力から反射光の有無を検出する反射光有無検出装置と、前記反射鏡の回転角度を検出する回転角検出装置と、前記反射鏡の傾斜角度を検出する傾斜角検出装置と、前記反射光有無検出装置の検出結果、前記回転角検出装置の検出結果、前記傾斜角検出装置の検出結果、及び、前記記憶装置に記憶された各反射板の反射部と非反射部のパターン情報に基づいて、反射板方向の検出及び反射板の識別を行う反射板検出装置と、前記反射板検出装置の反射板方向検出結果及び反射板識別結果と、前記記憶装置に記憶された各反射板の位置情報に基づいて、無人搬送車の位置を求める位置演算装置を具備することを特徴としている。
【００２９】
請求項２に係る発明は、無人搬送車の位置検出装置であり、無人搬送車の走行環境の複数個所に立設され、互いに異なるパターンで縦方向に区分して形成された反射部と非反射部を有すると共に縦方向両端に必ず反射部を有する反射板の位置情報、反射部と非反射部のパターン情報、及び、縦方向の長さ情報が予め記憶された記憶装置と、反射鏡と、前記反射鏡を回転させる回転装置と、前記反射鏡を傾斜した状態で支持し、かつ、その傾斜角度が遠心力により変化するように支持する反射鏡支持装置と、前記反射板の回転速度を変化させる速度変更装置と、下向きに設置され、前記反射鏡に対する光の照射及び反射鏡からの光の受光を行う光照射・受光装置と、前記光照射・受光装置の受光出力から反射光の有無を検出する反射光有無検出装置と、前記反射鏡の回転角度を検出する回転角検出装置と、前記反射鏡の傾斜角度を検出する傾斜角検出装置と、前記反射光有無検出装置の検出結果、前記回転角検出装置の検出結果、前記傾斜角検出装置の検出結果、前記記憶装置に記憶された各反射板の反射部と非反射部のパターン情報、及び、前記記憶装置に記憶された反射板の縦方向の長さ情報に基づいて、反射板方向の検出、反射板の識別及び無人搬送車から反射板までの距離の算出を行う反射板検出装置と、前記反射板検出装置の反射板方向検出結果、反射板識別結果及び距離算出結果と、前記記憶装置に記憶された各反射板の位置情報に基づいて、無人搬送車の位置を求める位置演算装置を具備することを特徴としている。
【００３２】
請求項３に係る発明は、請求項１又は２に係る発明の無人搬送車の位置検出装置において、前記反射鏡支持装置は反射鏡の上下いずれか一方を支持する弾性部材と、反射鏡の上下いずれか他方を揺動可能に支持する揺動支持部材を有することを特徴としている。
【００３３】
請求項４に係る発明は、請求項３に係る発明の無人搬送車の位置検出装置において、前記反射鏡の重心が回転中心軸からずれていることを特徴としている。
【００３４】
請求項５に係る発明は、請求項４に係る発明の無人搬送車の位置検出装置において、前記反射鏡の回転中心軸から離れた位置に重りを設けたことを特徴としている。
【００３５】
【発明の実施の形態】
以下、図１〜図７に基づいて、本発明の一実施形態例を説明する。図１は本発明の一実施形態例に係る反射板の配置を示し、図２は反射板における反射部と非反射部のパターン例を示す。図３は本発明の一実施形態例に係る位置検出装置の構成を示し、図４は反射鏡支持装置の構造例を示し、図５は反射鏡の回転速度と傾斜角度の変化との関係を示し、図６は反射鏡回転角度と反射光有無との関係を、反射鏡傾斜角度をパラメータとして示し、図７は無人搬送車から反射板までの距離算出の例を示す。
【００３６】
図１に示すように、無人搬送車１の走行環境例えば移動エリア２の周囲の複数個所（図１では３個所）に、反射板３₁、３₂、３₃が垂直に縦置きで設置されている。
【００３７】
各反射板３₁、３₂、３₃は図２に示すように、従来のものよりも縦（上下）方向に長くして反射板エリアを反射部と非反射部に縦方向に区分し、かつ、反射部と非反射部とが反射板間で異なるパターンとなるように形成してある。図１中の符号Ｌ₁、Ｌ₂、Ｌ₃は各反射板３₁、３₂、３₃の縦方向の長さを示す。
【００３８】
本例では、各反射板３₁、３₂、３₃の縦方向の長さＬ₁、Ｌ₂、Ｌ₃を全て等しくし、Ｌ＝Ｌ₁＝Ｌ₂＝Ｌ₃としてある。
【００３９】
図２に示す例では、反射部と非反射部のパターンを次のようになっている。
(1) 反射板３₁では、反射エリアのうち中央よりも下寄りに非反射部３₁-１を１つ形成し、残る上側部分と下側部分の全てに反射部３₁-Ｔ、３₁-Ｂを形成してある。
(2) 反射板３₂では、反射エリアのうち中央よりも上寄りに非反射部３₂-１を１つ形成し、残る上側部分と下側部分の全てに反射部３₂-Ｔ、３₂-Ｂを形成してある。
(3) 反射板３₃では、反射エリアのうち反射板３₁の非反射部３₁-１と同じ位置に下段の非反射部３₃-１を形成し、反射板３₂の非反射部３₂-１と同位置に上段の非反射部３₃-２を形成し、残る上側部分、下側部分、及び、上下段非反射部３₃-１、３₃-２間部分の全てに反射部３₃-Ｔ、３₃-Ｂ、３₃-Ｍを形成してある。
【００４０】
反射部３₁-Ｔ，３₁-Ｂ，３₂-Ｔ，３₂-Ｂ，３₃-Ｔ，３₃-Ｂの配置から判るように、各反射板３_1,３_2,３₃の縦方向両端部は必ず反射するようになっている。なお、各非反射部３₁-１，３₂-１，３₃-１，３₃-２は全て反射板の横方向一杯に形成してある。
【００４１】
上述したようなパターンで反射部と非反射部を形成するためには、反射板の縦方向の一部のみに反射面を形成したり、反射板の全面に反射面を形成した後で塗料やテープ等により縦方向の一部を覆って非反射部を形成するといった手段を採用することができる。
【００４２】
次に、本発明の一実施形態例に係る無人搬送車の位置検出装置を説明する。
【００４３】
図３に示すように、位置検出装置はメモリ１４と、回転装置１５と、反射鏡１６と、反射鏡支持装置１７と、速度変更装置１８と、回転角検出装置１９と、光照射・受光装置２０と、反射光有無検出装置２１と、傾斜角検出装置２２と、反射板検出装置２３と、位置演算装置２７を備える。反射板検出装置２３は反射板方向検出部２４と、反射板識別部２５と、距離算出部２６を有する。
【００４４】
便宜上、メモリ１４を第１記憶エリア１４-1と、第２記憶エリア１４-2と、第３記憶エリア１４-3に区分し、第１記憶エリア１４-1には各反射板３₁、３₂、３₃の分布地図等を位置情報として予め記憶し、第２記憶エリア１４-2には反射部と非反射部のパターン情報を各反射板３₁、３₂、３₃に対応させて予め記憶し、更に、第３記憶エリア１４-3には反射板の縦方向長さＬを予め記憶させてある。なお、反射板３₁、３₂、３₃間で縦方向長さが異なる場合は、各反射板に対応させてそれぞれの縦方向長さＬ₁、Ｌ₂、Ｌ₃を記憶させる。
【００４５】
回転装置１５は無人搬送車１の車体水平面内で回転できるように支持したステージ１５ａと、ステージ１５ａを回転駆動するモータ１５ｂからなる。
【００４６】
反射鏡１６は反射鏡支持装置１７を介して、傾斜角度が遠心力により変化できるように回転装置１５のステージ１５ａ上に支持してある。反射鏡１６は車体水平面から傾斜し、かつ、反射面は上を向いている。
【００４７】
本例の反射鏡支持装置１７は、図４に示すように、蝶番１７ａとばね１７ｂで構成されている。蝶番１７ａは、反射鏡１６の下部を揺動可能に支持するように、反射鏡１６の下端部と回転装置１５のステージ１５ａ間に取り付けてある。また、ばね１７ｂは、反射鏡１６の上部を弾性的に支持するように、反射鏡１６の上端部とステージ１５ａの突部１５ｃ間に取り付けてある。従って、回転装置１５により反射鏡１６が回転すると、遠心力が生じてばね１７ｂが縮み、反射鏡１６の傾斜角度が変化する。
【００４８】
このように蝶番１７ａとばね１７ｂで反射鏡支持装置１７を構成したことにより、反射鏡１６の上下方向への傾斜角度調整機構として、簡単、安価、堅牢、丁寿命、高速回転対応可能といった長所がある。
【００４９】
また、反射鏡１６の傾斜角度が遠心力によって容易に変化できるように、反射鏡１６の重心を回転中心軸からずらし、更に、反射鏡１６の回転中心軸から離れた位置に重り１６ａを取り付けてある。
【００５０】
更に、ばね１７ｂの強さを、下記条件を満足するように設定してある。
(1) 反射鏡１６が回転を停止しているときは、反射鏡１６の傾斜角度が水平面から４５度を越えること、例えば４６度になること。
(2) 反射鏡１６が回転すると、或る低速回転では、図５（ａ）に示すように小さな遠心力のために反射鏡１６の傾斜角度が水平面から４５度となること。
(3) 所定の最大回転速度では、図５（ｂ）に示すように大きな遠心力のために反射鏡１６の傾斜角度が水平面から４５度未満、例えば４２度となること。
【００５１】
速度変更装置１８は反射鏡１６の回転速度を変更するためのものであり、回転装置１５のステージ１５ａの回転速度を適宜な制御方法、例えばモータ１５ｂがパルスモータであればパルス周波数を変え、通常の直流モータであれば電圧を変える等、モータ１５ｂの種類に応じた調整方法で変更するものとしている。このようにモータ１５ｂの回転速度を調整する方法は簡単かつ高精度であるため、反射鏡１６の回転速度の精密な変更、従って、反射鏡１６の傾斜角度の精密な調整が可能である。
【００５２】
回転角検出装置１９は反射鏡１６の回転角度を検出するものであり、本例では、モータ１５ｂの回転角度を検出することにより、無人搬送車１の進行方向８を基準にして、反射鏡１６の回転角度を表す反射鏡回転角検出結果１９ａを出力するものとしている。
【００５３】
光照射・受光装置２０はレーザの照射機能及び受光機能を有しており、反射鏡１６の真上にて、車体垂直方向下向きに設置されている。
【００５４】
光照射・受光装置２０が照射するレーザ５は、車体垂直方向下向きに反射鏡１６に入射し、反射鏡１６の回転角度に応じた方向に反射するので、車体外方へ回転照射される。更に、反射鏡１６の回転速度の変更によって傾斜角度が変化するので、レーザ５の照射方向が上下に変化する。この結果、従来は平面上でしか走査されなかったが、反射鏡回転速度の変更によってレーザ５は円筒方向に走査されることになる。
【００５５】
一方、いずれかの反射板３₁、３₂、３₃で反射されたレーザ（反射レーザ）６は反射鏡１６に戻って入射するが、反射鏡１６から車体垂直方向上向きに出射したものだけを、光照射・受光装置２０が受光して、受光した反射レーザ光量を表す受光出力２０ａを出力する。
【００５６】
その際、反射鏡１６の傾斜角度が回転速度に応じて変化してレーザ５が円筒方向に走査されるので、無人搬送車１が傾いても、反射鏡１６がいずれかの傾斜角度になったときにレーザ５が反射板で反射され、反射レーザ６を受光することができる。
【００５７】
反射光有無検出装置２１は光照射・受光装置２０の受光出力２０ａから、閾値との比較による手法、あるいは微分演算を用いる手法等、適宜なピーク検出手法により、反射レーザ６の有無を検出して、反射光有無検出結果２１ａを出力する。
【００５８】
傾斜角検出装置２２は反射鏡１６の傾斜角度を検出するものであり、本例では、モータ１５ｂの回転速度と反射鏡１６の傾斜角度との関係対応を予め求めて、これを表すテーブルを予め設定しておき、モータ１５ｂの回転速度を検出してテーブルを参照することにより、車体水平面に対する反射鏡１６の傾斜角度を表す傾斜角検出結果２２ａを得て、これを出力するものとしている。
【００５９】
ここで、反射光有無検出装置２１の反射光有無検出結果２１ａと、回転角検出装置１９の反射鏡回転角検出結果１９ａと、傾斜角検出装置２２の反射鏡傾斜角検出結果２２ａとの関係は、図６に示すようになる。
【００６０】
即ち、車体水平面に対する反射鏡１６の傾斜角度をパラメータとし、横軸に反射鏡回転角度をとり、縦軸に反射光の有無をとると、図６（ａ）〜（ｅ）に示すようなグラフが得られる。θ₁、θ₂、θ₃は反射レーザ６が有った時の反射鏡回転角度であり、無人搬送車１の進行方向８を基準にして無人搬送車１から見た反射板方向を表す。
【００６１】
図６（ａ）は反射鏡１６が４５度傾斜し、従って、レーザ５が水平に照射された場合のグラフであり、全ての反射板の下端側反射部３₁-Ｂ, ３₂-Ｂ，３₃-Ｂでレーザ５が反射されて、それらの反射レーザ６が受光される様子を示している。つまり、どの非反射部にも影響されず、全ての反射板方向θ₁、θ₂、θ₃が検出可能であることが判る。
【００６２】
図６（ｂ）は反射鏡１６が45.5度傾斜し、従って、レーザ５が水平から１度上に照射された場合のグラフであり、２つの反射板からはレーザ５が非反射部３₁-１, ３₃-１に当たって反射されないが、１つの反射板からはその上端側反射部３₃-Ｔでレーザ５が反射されて、反射レーザ６が受光される様子を示している。つまり、反射板方向θ₂だけは検出可能であることが判る。
【００６３】
図６（ｃ）は反射鏡１６が４６度傾斜し，従って、レーザ５が水平から２度上に照射された場合のグラフであり、各反射板の上端側反射部３₁-Ｔ、下端側反射部３₂-Ｂ、中間反射部３₃-Ｍでレーザ５が反射されて、それらの反射レーザ６が受光される様子を示している。つまり、どの非反射部にも影響されず、全ての反射板方向θ₁、θ₂、θ₃が検出可能であることが判る。
【００６４】
図６（ｄ）は反射鏡１６が46.5度傾斜し、従って、レーザ５が水平から３度上に照射された場合のグラフであり、２つの反射板からはレーザ５が非反射部３₂-１, ３₃-２に当たって反射されないが、１つの反射板からはその上端側反射部３₁-Ｔでレーザ５が反射されて、反射レーザ６が受光される様子を示している。つまり、反射板方向θ₁だけは検出可能であることが判る。
【００６５】
図６（ｅ）は反射鏡１６が４７度傾斜し、従って、レーザ５が水平から４度上に照射された場合のグラフであり、全ての反射板の上端側反射部３₁-Ｔ, ３₂-Ｔ，３₃-Ｔでレーザ５が反射されて、それらの反射レーザ６が受光される様子を示している。つまり、どの非反射部にも影響されず、全ての反射板方向θ₁、θ₂、θ₃が検出可能であることが判る。
【００６６】
反射板検出装置２３は、反射光有無検出装置２１の反射光有無検出結果２１ａと、回転角検出装置１９の反射鏡回転角検出結果１９ａと、傾斜角検出装置２２の反射鏡傾斜角検出結果２２ａと、メモリ１４の第２記憶エリア１４−２に記憶した各反射板３₁,３₂ ３₃ の反射部と非反射部のパターン情報及び第３記憶エリア１４−３に記憶した反射板の縦方向の長さ情報とに基づいて、反射板方向の検出と、反射板の識別と、無人搬送車から反射板までの距離の算出を行う。
【００６７】
本例では、反射板検出装置２３のうち、反射板方向検出部２４が反射板方向の検出を分担し、反射板識別部２５が反射板の識別を分担し、距離算出部２６が反射板までの距離算出を分担するものとしている。
【００６８】
具体的には、反射板方向検出部２４は反射光有無検出結果２１ａと、反射鏡回転角検出結果１９ａを入力し、反射レーザ６が有った時点毎に、その時点での反射鏡回転角度（レーザ照射方向）を回転角検出結果１９ａから調べることにより、反射板方向検出結果９を出力する。
【００６９】
例えば、図１０に示したように、無人搬送車１から見た各反射板方向７₁、７₂、７₃を無人搬送車１の進行方向８を基準にした角度θ₁、θ₂、θ₃として検出し、図１１に示したような無人搬送車１から見てどの方向（角度θ₁、θ₂、θ₃）に反射板が存在しているかという反射板方向検出結果９を得る。
【００７０】
この反射板方向検出においては、反射鏡１６の傾斜角度が変化してレーザ５が円筒状に回転走査するので、図６（ａ）〜（ｅ）のグラフから判るように、無人搬送車１が傾いても反射板３₁、３₂、３₃が光の回転走査範囲から外れてしまうことがなく、全ての反射板方向θ₁、θ₂、θ₃を検出することが可能である。
【００７１】
反射板識別部２５は反射板方向検出結果９と、反射光有無検出結果２１ａと、反射鏡回転角検出結果１９ａと、反射鏡傾斜角検出結果２２ａを入力して、反射レーザ６が有った時の反射鏡傾斜角度と無かった時の反射鏡傾斜角度から、同一の反射板方向検出角度θ_n（ｎ＝１，２，３）毎に反射鏡傾斜角度と反射光有無の関係を表すパターンを作成する，そして、このパターンと第２記憶エリア１４-2に記憶した反射部と非反射部のパターンを比較し、良く一致するものを探すことにより、角度θ_nの方向にどの反射板３_n（ｎ＝１，２，３）が存在するかを識別し、反射板識別結果２５ａを出力する。
【００７２】
反射板の識別が可能な理由は、図６（ａ）〜（ｅ）のグラフから判るように、同じ反射板であっても、反射鏡傾斜角度に応じて、反射レーザ６が有ったり、無かったりするが、その様子は各反射板３_1,３_2,３₃における反射部と非反射部のパターンに対応するからである。
【００７３】
つまり、反射鏡傾斜角度を或る程度高い分解能で変えることにより、反射部と非反射部のパターン情報を参照すれば、反射光有無検出結果２１ａと反射鏡傾斜角検出結果２２ａとの関係から、どの反射板について反射板方向を検出したかを識別することができる。
【００７４】
距離算出部２６は反射板識別結果２５ａと、反射光有無検出結果２１ａと、反射鏡回転角検出結果１９ａと、反射鏡傾斜角検出結果２２ａを入力して、同一の反射板３_n（ｎ＝１，２，３）毎に、反射レーザ６を検出し始めた時の反射鏡傾斜角度φ_bnと、反射レーザ６を検出し終わった時の反射鏡傾斜角度φ_enを調べる。そして、その差Δφ_n（＝｜φ_bn−φ_en｜）と、第３記憶エリア１４-3に記憶した反射板３_nの縦方向の長さＬ_n（ｎ＝１，２，３）を用いて、式Ｘ_n＝Ｌ_n／tan(２Δφ_n) により、角度θ_nの方向に存在する反射板３_n（ｎ＝１，２，３）までの距離Ｘ_nを算出し、距離算出結果２６ａを出力する。なお、式Ｘ_n＝Ｌ_n／tan(２｜φ_bn−φ_en｜) で距離Ｘ_nを算出することもできる。
【００７５】
距離算出が可能な理由は、図６（ａ）〜（ｅ）のグラフから判るように、反射鏡傾斜角度を或る程度高い分解能で変えることにより、全ての反射板について、下端側の反射部３₁-Ｂ, ３₂-Ｂ，３₃-Ｂからも、上端側の反射部３₁-Ｔ, ３₂-Ｔ，３₃-Ｔからも反射レーザ６の検出が可能だからである。
【００７６】
つまり、各反射板３_n(n=1,2,3) について、下端側反射部３_n−Ｂからの反射レーザ６を検出し始めた時の反射鏡傾斜角度をφ_bn、上端側反射部３_n−Ｔからの反射レーザ６を検出し終わった時の反射鏡傾斜角度をφ_enとすると、その差Δφ_n（＝φ_bn−φ_en）と、各反射板の縦方向の長さＬ_nと、無人搬送車１からの各反射板の距離Ｘ_nとの間には、Ｘ_ntan(２Δφ_n) ＝Ｘ_ntan ２（φ_bn−φ_en）＝Ｌ_nという関係がある。従って、反射鏡傾斜角度の分解能が十分であれば、図７に示す例において、無人搬送車１から各反射板３_nまでの距離Ｘ_nは各反射板の縦方向の長さＬ_nを参照することにより、式Ｘ_n＝Ｌ_n／tan(２Δφ_n) 又はＸ_n＝Ｌ_n／tan ２（φ_bn−φ_en）で算出することができる。なお、φ_bnとφ_enの大小関係は、反射鏡１６を停止又は低速から高速へ増速回転しながら傾斜角度を変化させる場合はφ_bn＞φ_enであるが、逆に高速から停止又は低速へ減速回転しながら傾斜角度を変化させる場合はφ_bn＜φ_enであるから、一般には、Δφ_n＝｜φ_bn−φ_en｜とする。
【００７７】
位置演算装置２７として、下記２種類が考えられる。
(1) 反射板方向検出結果９と、反射板識別結果２５ａと、第１記憶エリア１４-1に記憶した反射板分布地図１０等の反射板位置情報に基づいて、無人搬送車１の位置を求める位置演算装置。
(2) 反射板方向検出結果９と、反射板識別結果２５ａと、距離算出結果２６ａと、第１記憶エリア１４-1に記憶した反射板分布地図１０等の反射板位置情報に基づいて、無人搬送車１の位置を求める位置演算装置。
【００７８】
このような２種類の位置演算装置を採用できる理由を以下に示す。
【００７９】
全ての反射板が略等距離であると想定すれば、反射鏡１６の傾斜角度が変化することにより、無人搬送車１が多少傾いても、反射板方向検出結果９と第１記憶エリア１４-1に記憶した反射板位置情報のみに基づく従来手法（図１３参照）でも、無人搬送車１の位置１１と進行方向１２を求めることができる。これは、各反射板に非反射部が無い場合も同様である。
【００８０】
しかし、反射板間で反射部と非反射部のパターンが異なることを利用することにより反射板を識別できるので、反射板識別結果２５ａを用いれば、どの反射板がどの方向に存在するかが判る。
【００８１】
そこで、１つ目の位置演算装置２７では反射板方向検出結果９と反射板識別結果２５ａより、無人搬送車１から見てどの反射板３₁,３₂,３₃ がどの方向θ₁,θ₂,θ₃に存在するかを把握し、この情報（３₁,θ₁)（３₂,θ₂)（３₃,θ₃)と反射板分布地図１０等の反射板位置情報を対応させることにより、反射板の距離が未知且つ異なっていても、無人搬送車１の位置と進行方向を精度良く検出することができる。これにより、反射板の分布を格別に工夫しなくても、位置の誤検出を防ぐことが可能になる。
【００８２】
更に、反射板の上下両端の反射部を利用することにより、反射板までの距離を算出できるので、反射板識別結果２５ａと距離算出結果２６ａの両方を用いれば、どの反射板がどの方向におおよそどの位の距離で存在するかが判る。
【００８３】
そこで、２つ目の位置演算装置２７では反射板方向検出結果９と反射板識別結果２５ａと距離算出結果２6 ａより、無人搬送車１から見てどの反射板３₁,３₂,３₃ がどの方向θ₁,θ₂,θ₃にどの位の距離Ｘ₁,Ｘ₂,Ｘ₃で存在するかを把握し、この情報（３₁,θ₁,Ｘ₁)（３₂,θ₂,Ｘ₂)（３₃,θ₃,Ｘ₃)と反射板分布地図１０等の反射板の位置情報を対応させることにより、反射板の距離が異なっていても無人搬送車１の位置と進行方向をより精度良く検出することができる。これにより、反射板の分布を格別に工夫しなくても、位置の誤検出を防ぐことが可能になる。
【００８４】
【発明の効果】
請求項１に係る発明によれば、位置検出用反射板が反射板間で互いに異なるパターンで縦方向に区分して形成された反射部と非反射部を有するので、光を円筒形状に回転走査して照射すれば、どの反射板がどの方向に存在するかという、反射板方向の検出及び反射板の認識が可能になる。更に、反射鏡をその傾斜角度が遠心力により変化するように支持して反射板の回転速度を変化させることにより、光を円筒形状に回転走査し、反射板の位置情報に加えて予め記憶した反射部と非反射部のパターン情報を用いて、どの反射板がどの方向に存在するかという、反射板方向の検出及び反射板の認識を行って無人搬送車の位置を検出するので、位置検出の精度が高くなる。従って、反射板の分布を格別に工夫しなくても、位置の誤検出を防ぐことができる。また、光を円筒状に回転走査するので、無人搬送車が傾くことによって反射板が光の回転走査範囲から外れてしまうことがなくなる。
【００８５】
請求項２に係る発明によれば、位置検出用反射板が反射板間で互いに異なるパターンで縦方向に区分して形成された反射部と非反射部を有するだけでなく、更に、縦方向両端には必ず反射部を有するので、光を円筒形状に回転走査して照射すれば、どの反射板がどの方向におおよそどの位の距離で存在するかという、反射板方向の検出、反射板の認識及び距離算出が全て可能になる。更に、反射鏡をその傾斜角度が遠心力により変化するように支持して反射板の回転速度を変化させることにより、光を円筒形状に回転走査し、反射板の位置情報及び反射部と非反射部のパターン情報に加えて、予め記憶した反射板の縦方向の長さ情報を用いて、どの反射板がどの方向におおよそどの位の距離で存在するかという、反射板方向の検出、反射板の認識及び距離算出を行って無人搬送車の位置を検出するので、位置検出の精度が一層高くなる。従って、位置の誤検出を防ぐことができる。このも場合も、光を円筒状に回転走査するので、無人搬送車が傾くことによって反射板が光の回転走査範囲から外れてしまうことがなくなる。
【００８８】
請求項３に係る発明によれば、弾性部材と揺動支持部材で、反射鏡をその傾斜角度が遠心力により変化するように支持するので、反射鏡の支持機構が簡単である。
【００８９】
請求項４に係る発明によれば、反射鏡の重心が回転中心軸からずれているので、反射鏡の傾斜角度が遠心力によって容易に変化することができる。
【００９０】
請求項５に係る発明によれば、反射鏡の回転中心軸から離れた位置に重りがあるので、反射鏡の傾斜角度がより容易に変化することができる。
【図面の簡単な説明】
【図１】本発明の一実施形態例に係る反射板の配置を示す図。
【図２】反射板における反射部と非反射部のパターン例を示す図。
【図３】本発明の一実施形態例に係る位置検出装置の構成を示す図。
【図４】反射鏡支持装置の構造例を示す図。
【図５】反射鏡の回転速度と傾斜角度の変化との関係を示す図。
【図６】反射鏡回転角度と反射光有無との関係を、反射鏡傾斜角度をパラメータとして示す図。
【図７】無人搬送車から反射板までの距離算出の説明図。
【図８】反射板を用いた位置検出に基づく無人搬送車の誘導方式を説明する図。
【図９】反射板の有無と反射レーザの関係を示す図。
【図１０】無人搬送車から見た反射板方向を示す図。
【図１１】反射板方向検出結果の例を示す図。
【図１２】反射板分布地図の例を示す図。
【図１３】反射板分布地図上での無人搬送車の位置と進行方向の検索結果を示す図。
【図１４】位置検出装置の従来の構成例を示す図。
【図１５】反射鏡回転角度と、受光出力と、反射光有無との関係を示す図。
【符号の説明】
１無人搬送車
２移動エリア
３₁、３₂、３₃ 反射板
３₁-１、３₂-１、３₃-１、３₃-２非反射部
３₁-Ｔ、３₂-Ｔ、３₃-Ｔ上端側の反射部
３₁-Ｂ、３₂-Ｂ、３₃-Ｂ下端側の反射部
３₃-Ｍ中間の反射部
４位置検出装置
５レーザ
６反射レーザ
７₁、７₂、７₃ 無人搬送車から見た反射板方向
８無人搬送車の進行方向
９反射板方向検出結果
１０反射板分布地図（反射板位置情報）
１１反射板分布地図上の位置
１２反射板分布地図上の位置を起点とする方向
１３₁、１３₂、１３₃ 反射板分布地図上での反射板方向
１４メモリ
１４-1 第１記憶エリア
１４-2 第２記憶エリア
１４-3 第３記憶エリア
１５回転装置
１５ａステージ
１５ｂモータ
１５ｃ突部
１６反射鏡
１６ａ重り
１７反射鏡支持装置
１７ａ蝶番
１７ｂばね
１８速度変更装置
１９回転角検出装置
１９ａ反射鏡回転角検出結果
２０光照射・受光装置
２０ａ受光出力
２１傾斜角検出装置
２１ａ反射鏡傾斜角検出結果
２２反射光有無検出装置
２２ａ反射光有無検出結果
２３反射板検出装置
２４反射板方向検出部
２５反射板識別部
２５ａ反射板識別結果
２６距離演算部
２６ａ距離演算結果
２７位置演算装置
２８₁、２８₂、２８₃ 従来の反射板
２９従来の反射板方向検出装置
３０従来の位置演算装置[0001]
BACKGROUND OF THE INVENTION
  The present invention is an automatic guided vehicle that is useful for guiding automatic guided vehicles.ofThe present invention relates to a position detection device.
[0002]
[Prior art]
[Optical tape guiding method]
Conventionally, as a guide method for an automatic guided vehicle, a tape having a good light reflectance (hereinafter referred to as an optical tape) is attached to a floor surface on which the automatic guided vehicle travels, and light is irradiated from the automatic guided vehicle to the floor surface. In general, an optical tape guiding method in which an automatic guided vehicle is caused to travel on the route of the optical tape by detecting the optical tape from the reflected light. However, in the optical tape guiding method, if the optical tape reflectance decreases due to dirt, such as when the optical tape is stepped on a wheel, the automatic guided vehicle may not be able to detect the optical tape. is there.
[0003]
[Guidance method based on position detection using reflector]
In order to solve the problems of the optical tape guiding method, reflectors are erected at a plurality of locations in the traveling environment of the automated guided vehicle, and light (usually a laser) is rotated and scanned from the automated guided vehicle. A guidance method for detecting the direction of the vehicle and detecting the position of the vehicle has been studied.
[0004]
[Position detection method using reflector]
Hereinafter, a position detection method using a reflector will be described with reference to FIGS. FIG. 8 is a diagram for explaining a guidance method based on position detection using a reflector, FIG. 9 shows the relationship between the presence or absence of the reflector and the reflected laser, and FIG. 10 shows the reflector direction as seen from the automatic guided vehicle. 11 shows an example of the reflector direction detection result, FIG. 12 shows an example of the reflector distribution map, and FIG. 13 shows the search result of the position and the traveling direction of the automatic guided vehicle on the reflector distribution map.
[0005]
As shown in FIG. 8, the reflectors 28 are provided at a plurality of locations (three locations in the figure) around the moving area 2 of the automatic guided vehicle 1.₁, 28₂, 28_ThreeIs set up. In each reflecting plate, no non-reflecting portion is formed in the reflecting area. A position detection device 4 is mounted on the automatic guided vehicle 1.
[0006]
Conventionally, the position detection device irradiates the laser 5 in all directions only 360 ° in the horizontal direction, detects the direction of each reflector from the presence or absence of the reflection, detects the reflector direction detection result, and each reflector 28.₁, 28₂, 28_ThreeThe position of the automatic guided vehicle 1 is detected from the known position information.
[0007]
That is, as shown in FIG. 9, when the laser 5 is irradiated in the direction in which the reflector is present, it is strongly reflected and returns to the position detecting device as the reflected laser 6, but in the direction without the reflector. If you do, you will not return. Since the irradiation direction of the laser 5 when detecting the reflection laser 6 is the reflection plate direction, the reflection plate direction can be detected by examining the laser irradiation direction when the reflection laser 6 is detected.
[0008]
As shown in FIG. 10, each reflector direction 7 as seen from the automatic guided vehicle 1.₁, 7₂, 7_ThreeIs an angle θ based on the traveling direction 8 of the automatic guided vehicle 1₁, Θ₂, Θ_ThreeDetected as That is, as shown in FIG. 11, which direction (angle θ₁, Θ₂, Θ_Three), A reflection plate direction detection result 9 indicating whether a reflection plate is present is obtained.
[0009]
Therefore, each reflecting plate 28 is previously placed in the position detection device.₁, 28₂, 28_ThreeBy storing this position information, it is possible to know the position and traveling direction of the automatic guided vehicle 1 by associating the reflection plate direction detection result 9 with the known reflection plate position information.
[0010]
Consider the case where a reflector distribution map 10 as shown in FIG. 12 is stored as reflector position information.
[0011]
In this case, as shown in FIG. 13, a certain position 11 and a certain direction 12 starting from the position 11 are set on the reflector distribution map 10. And each reflector 28 seen from this position 11₁, 28₂, 28_ThreeDirection 13₁, 13₂, 13_ThreeAnd the direction 12 starting from the position 11 is the reflection plate direction detection result (θ₁, Θ₂, Θ_Three) If it agrees well with 9, it can be said that the automatic guided vehicle 1 exists at the position 11 and the direction 12 is the traveling direction of the automatic guided vehicle 1. Therefore, the reflection plate direction detection result (θ₁, Θ₂, Θ_Three) By searching the reflector distribution map 10 for a position 11 and a direction 12 that are in good agreement with 9, the position and traveling direction of the automatic guided vehicle 1 can be detected.
[0012]
Next, a conventional example of the position detection device will be described with reference to FIGS. FIG. 14 shows the conventional configuration of the position detection device, and FIG. 15 shows the relationship between the mirror rotation angle, the light reception output, and the presence or absence of reflected light.
[0013]
As shown in FIG. 14, the conventional position detecting device includes a memory 14, a rotating device 15, a reflecting mirror 16, a rotating angle detecting device 19, a light irradiation / light receiving device 20, and a reflected light presence / absence detecting device 21. The reflector direction detection device 29 and the position calculation device 30 are provided.
[0014]
The memory 14 has all the reflectors 28 in advance._1,28_2,28_ThreeAs the position information, the reflector distribution map 10 is recorded.
[0015]
The rotating device 15 includes a stage 15a that can rotate in a horizontal plane of the vehicle body, and a motor 15b that rotationally drives the stage 15a.
[0016]
The reflecting mirror 16 is fixed to the stage 15a with its inclination angle fixed at 45 degrees and facing upward.
[0017]
The rotation angle detection device 19 outputs a reflection mirror rotation angle detection result 19a representing the rotation angle of the reflection mirror 16 by detecting the rotation angle of the motor 15b. The reference for the rotation angle of the reflecting mirror 16 is normally the traveling direction 8 of the automatic guided vehicle 1.
[0018]
The light irradiation / light receiving device 20 has a laser irradiation function and a light receiving function, and is installed directly above the reflecting mirror 16 and directed downward in the vehicle body vertical direction.
[0019]
Accordingly, when the light irradiating / receiving device 20 irradiates the laser 5, the laser 5 enters the reflecting mirror 16 and is reflected, and is rotated and scanned 360 degrees in all directions only in the horizontal plane in accordance with the rotation of the reflecting mirror 16. .
[0020]
On the other hand, the laser (reflected laser) 6 reflected by one of the reflecting plates is incident on the reflecting mirror 16 and reflected upward in the vertical direction of the vehicle body, and is received by the light irradiation / light receiving device 20. The light irradiating / receiving device 20 outputs a received light output 20a indicating the amount of light of the reflected laser 6 received.
[0021]
The reflected light presence / absence detecting device 21 detects the presence / absence of the reflected laser 6 from the light receiving output 20a of the light irradiation / light receiving device 20, and outputs a reflected light presence / absence detection result 21a.
[0022]
Here, the relationship among the light reception output 20a of the light irradiation / light reception device 20, the reflected light presence / absence detection result 21a of the reflected light presence / absence detection device 21, and the reflection mirror rotation angle detection result 19a of the rotation angle detection device 19 is shown in FIG. As shown.
[0023]
FIG. 15A shows a graph in which the horizontal axis represents the reflecting mirror rotation angle, and the vertical axis represents the light receiving output, and FIG. 15B represents the reflecting mirror rotation angle on the horizontal axis and the presence or absence of the reflecting laser on the vertical axis. A graph is shown. Reflector rotation angle θ when there is a reflection laser 6₁, Θ₂, Θ_ThreeRepresents the direction of the reflector.
[0024]
Based on the reflected light presence / absence detection result 21a and the reflection mirror rotation angle detection result 19a, the reflection plate direction detection device 29 reflects the reflection mirror rotation angle on the horizontal axis and the reflection on the vertical axis, as shown in FIG. By creating a graph showing the presence or absence of the laser, it is determined from which direction the reflection laser 6 is coming, the reflection plate direction is detected, and the reflection plate direction detection result 9 is output.
[0025]
Based on the reflection plate position detection result 9 of the reflection plate direction detection device 29 and the reflection plate position information such as the reflection plate distribution map 10 stored in the memory 14, the position calculation device 30 is based on these correspondences and the automatic guided vehicle. 1 position 11 and traveling direction 12 are obtained.
[0026]
[Problems to be solved by the invention]
The position detection method using the reflector and light (laser) described above has an advantage that the light irradiation / light receiving device 20 and the like can be made inexpensive because it is sufficient to measure only the direction of the reflector. However, there are the following problems.
(1) Since the tilt angle of the reflecting mirror 16 is fixed at 45 °, the automatic guided vehicle 1 tilts and the irradiation plane of the laser 5 is the reflecting plate 28.₁, 28₂, 28_ThreeIf it deviates, the direction of the reflector cannot be detected, and information necessary for determining the position of the automatic guided vehicle 1 is insufficient.
(2) Which reflector 28 is the reflection laser 6₁, 28₂, 28_ThreeInformation on whether or not the light is reflected from is not detected. Further, the distance from the automatic guided vehicle 1 to the reflecting plate is not detected. Therefore, the reflector 28₁, 28₂, 28_ThreeIt is necessary to devise the installation distribution of the automatic guided vehicle 1 so that the position of the automatic guided vehicle 1 is not erroneously detected.
[0027]
  The subject of this invention is the automatic guided vehicle which solves the problem of the said prior artofThe object is to provide a position detection device.
[0028]
[Means for Solving the Problems]
  The invention according to claim 1 is the position detection of the automatic guided vehicle.apparatusAnd has a reflective portion and a non-reflective portion that are erected at a plurality of locations in the driving environment of the automatic guided vehicle and are formed by dividing the vertical direction in different patterns.A storage device that stores in advance the position information of the reflecting plate and the pattern information of the reflecting portion and the non-reflecting portion, a reflecting mirror, a rotating device that rotates the reflecting mirror, and the reflecting mirror is supported in an inclined state, And a reflecting mirror supporting device that supports the tilt angle to be changed by centrifugal force, a speed changing device that changes the rotation speed of the reflecting plate, and a light irradiation and reflecting mirror that is installed downward. A light irradiation / light receiving device for receiving light from the light, a reflected light presence / absence detecting device for detecting the presence / absence of reflected light from a light receiving output of the light irradiation / light receiving device, and a rotation angle detection for detecting a rotation angle of the reflecting mirror Device, tilt angle detection device for detecting the tilt angle of the reflecting mirror, detection result of the reflected light presence / absence detection device, detection result of the rotation angle detection device, detection result of the tilt angle detection device, and the storage Memorized in the device A reflection plate detection device for detecting the reflection plate direction and identifying the reflection plate based on the pattern information of the reflection portion and the non-reflection portion of each reflection plate, the reflection plate direction detection result of the reflection plate detection device, and the reflection plate A position calculation device for determining the position of the automatic guided vehicle based on the identification result and the position information of each reflector stored in the storage device;It is characterized by that.
[0029]
  The invention according to claim 2NothingDetecting the position of a guided vehicleEquipment,While having a reflective part and a non-reflective part, which are erected at a plurality of locations in the traveling environment of the automatic guided vehicle and formed in different patterns in the vertical direction.Always have reflections at both ends in the vertical directionA storage device in which position information of the reflecting plate, pattern information of the reflecting and non-reflecting portions, and length information in the vertical direction are stored in advance, a reflecting mirror, a rotating device that rotates the reflecting mirror, and the reflecting mirror And a reflecting mirror support device that supports the tilt angle to be changed by centrifugal force, a speed changing device that changes the rotation speed of the reflecting plate, and the reflection mirror. A light irradiating / receiving device for irradiating light to the mirror and receiving light from the reflecting mirror, a reflected light presence / absence detecting device for detecting the presence / absence of reflected light from the light receiving output of the light irradiating / receiving device, and A rotation angle detection device that detects a rotation angle, a tilt angle detection device that detects a tilt angle of the reflecting mirror, a detection result of the reflected light presence detection device, a detection result of the rotation angle detection device, and the tilt angle detection device Detection result, Based on the pattern information of the reflective part and the non-reflective part of each reflector stored in the device and the length information in the vertical direction of the reflector stored in the storage device, detection of the reflector direction, Reflector detection device that performs identification and calculation of the distance from the automatic guided vehicle to the reflector, the reflector direction detection result of the reflector detector, the reflector identification result and the distance calculation result, and stored in the storage device Provided with a position calculation device for determining the position of the automatic guided vehicle based on the position information of each reflector.It is characterized by that.
[0032]
  Claim3The invention according to claim1Or2In the position detection device of the automatic guided vehicle according to the invention, the reflecting mirror support device includes an elastic member that supports either the upper or lower side of the reflecting mirror, and a swing support that supports the upper or lower side of the reflecting mirror so as to be swingable. It has the member.
[0033]
  Claim4The invention according to claim3In the position detection device for an automatic guided vehicle according to the present invention, the center of gravity of the reflecting mirror is deviated from the rotation center axis.
[0034]
  Claim5The invention according to claim4In the position detection device for an automatic guided vehicle according to the present invention, a weight is provided at a position away from the rotation center axis of the reflecting mirror.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the arrangement of reflecting plates according to an embodiment of the present invention, and FIG. 2 shows an example of patterns of reflecting and non-reflecting portions on the reflecting plate. FIG. 3 shows a configuration of a position detection device according to an embodiment of the present invention, FIG. 4 shows an example of the structure of a reflecting mirror support device, and FIG. 5 shows the relationship between the rotational speed of the reflecting mirror and the change in tilt angle. 6 shows the relationship between the rotation angle of the reflecting mirror and the presence or absence of reflected light, with the reflecting mirror tilt angle as a parameter, and FIG. 7 shows an example of calculating the distance from the automatic guided vehicle to the reflecting plate.
[0036]
As shown in FIG. 1, the reflector 3 is provided at a plurality of locations (three locations in FIG. 1) around the traveling environment of the automatic guided vehicle 1, for example, the moving area 2.₁3₂3_ThreeAre installed vertically and vertically.
[0037]
Each reflector 3₁3₂3_ThreeAs shown in FIG. 2, the reflector area is vertically divided into a reflective part and a non-reflective part by making it longer in the vertical (vertical) direction than the conventional one, and the reflective part and the non-reflective part are reflected. They are formed so as to have different patterns between the plates. Reference L in FIG.₁, L₂, L_ThreeIs each reflector 3₁3₂3_ThreeThe length of the vertical direction is shown.
[0038]
In this example, each reflector 3₁3₂3_ThreeL length in the vertical direction₁, L₂, L_ThreeAre all equal, L = L₁= L₂= L_ThreeIt is as.
[0039]
In the example shown in FIG. 2, the pattern of the reflective part and the non-reflective part is as follows.
(1) Reflector 3₁Then, in the reflection area, the non-reflection part 3 is located below the center.₁-1 is formed, and the remaining upper part and the lower part are all reflective part 3₁-T, 3₁-B is formed.
(2) Reflector 3₂Then, in the reflection area, the non-reflection part 3 is located above the center.₂-1 is formed, and the remaining upper part and the lower part are all reflective part 3₂-T, 3₂-B is formed.
(3) Reflector 3_ThreeThen, the reflection plate 3 in the reflection area.₁Non-reflective part 3₁Lower non-reflective part 3 at the same position as -1._Three-1 is formed and the reflector 3₂Non-reflective part 3₂Non-reflective part 3 in the upper stage at the same position as -1._Three-2 is formed, and the remaining upper portion, lower portion, and upper and lower non-reflective portions 3 are formed._Three-1, 3_Three-Reflection part 3 in all parts between 2_Three-T, 3_Three-B, 3_Three-M is formed.
[0040]
Reflector 3₁-T, 3₁-B, 3₂-T, 3₂-B, 3_Three-T, 3_ThreeAs can be seen from the arrangement of -B, each reflector 3_1,3_2,3_ThreeBoth end portions in the vertical direction are always reflected. In addition, each non-reflective part 3₁-1,3₂-1,3_Three-1,3_Three-2 is all formed in the horizontal direction of the reflector.
[0041]
In order to form the reflective portion and the non-reflective portion with the pattern as described above, a reflective surface is formed only on a part of the reflective plate in the vertical direction, or after the reflective surface is formed on the entire surface of the reflective plate, Means such as forming a non-reflective portion by covering a part in the vertical direction with a tape or the like can be employed.
[0042]
Next, a position detection device for an automatic guided vehicle according to an embodiment of the present invention will be described.
[0043]
As shown in FIG. 3, the position detection device includes a memory 14, a rotation device 15, a reflection mirror 16, a reflection mirror support device 17, a speed change device 18, a rotation angle detection device 19, and a light irradiation / light reception device. 20, a reflected light presence / absence detection device 21, an inclination angle detection device 22, a reflection plate detection device 23, and a position calculation device 27. The reflection plate detection device 23 includes a reflection plate direction detection unit 24, a reflection plate identification unit 25, and a distance calculation unit 26.
[0044]
For convenience, the memory 14 is divided into a first storage area 14-1, a second storage area 14-2, and a third storage area 14-3.₁3₂3_ThreeA distribution map or the like is stored in advance as position information, and the pattern information of the reflection part and the non-reflection part is stored in the second storage area 14-2.₁3₂3_ThreeIn addition, the longitudinal length L of the reflector is stored in advance in the third storage area 14-3. Reflector 3₁3₂3_ThreeIf the length in the vertical direction differs, the length L in the vertical direction corresponding to each reflector₁, L₂, L_ThreeRemember.
[0045]
The rotating device 15 includes a stage 15a that is supported so as to be able to rotate in a horizontal plane of the automatic guided vehicle 1, and a motor 15b that rotationally drives the stage 15a.
[0046]
The reflecting mirror 16 is supported on the stage 15a of the rotating device 15 through the reflecting mirror support device 17 so that the inclination angle can be changed by centrifugal force. The reflecting mirror 16 is tilted from the horizontal plane of the vehicle body, and the reflecting surface faces upward.
[0047]
As shown in FIG. 4, the reflecting mirror support device 17 of this example includes a hinge 17a and a spring 17b. The hinge 17a is attached between the lower end of the reflecting mirror 16 and the stage 15a of the rotating device 15 so as to swingably support the lower part of the reflecting mirror 16. The spring 17b is attached between the upper end of the reflecting mirror 16 and the protrusion 15c of the stage 15a so as to elastically support the upper part of the reflecting mirror 16. Therefore, when the reflecting mirror 16 is rotated by the rotating device 15, a centrifugal force is generated, the spring 17b is contracted, and the inclination angle of the reflecting mirror 16 is changed.
[0048]
By configuring the reflector support device 17 with the hinge 17a and the spring 17b as described above, the tilt angle adjusting mechanism for the reflector 16 in the vertical direction has advantages such as simple, inexpensive, robust, life span, and high speed rotation. is there.
[0049]
Further, the center of gravity of the reflecting mirror 16 is shifted from the rotation center axis so that the tilt angle of the reflecting mirror 16 can be easily changed by centrifugal force, and a weight 16a is attached at a position away from the rotation center axis of the reflecting mirror 16. is there.
[0050]
Furthermore, the strength of the spring 17b is set so as to satisfy the following conditions.
(1) When the reflecting mirror 16 stops rotating, the inclination angle of the reflecting mirror 16 exceeds 45 degrees from the horizontal plane, for example, 46 degrees.
(2) When the reflecting mirror 16 rotates, the tilt angle of the reflecting mirror 16 becomes 45 degrees from the horizontal plane due to a small centrifugal force as shown in FIG.
(3) At a predetermined maximum rotation speed, the tilt angle of the reflecting mirror 16 is less than 45 degrees, for example, 42 degrees from the horizontal plane due to a large centrifugal force as shown in FIG.
[0051]
The speed changing device 18 is for changing the rotational speed of the reflecting mirror 16, and the rotational speed of the stage 15 a of the rotating device 15 is appropriately controlled. For example, if the motor 15 b is a pulse motor, the pulse frequency is changed. If the motor is a direct current motor, the voltage is changed by an adjustment method according to the type of the motor 15b. Since the method of adjusting the rotational speed of the motor 15b is simple and highly accurate in this way, it is possible to precisely change the rotational speed of the reflecting mirror 16, and thus to precisely adjust the tilt angle of the reflecting mirror 16.
[0052]
The rotation angle detection device 19 detects the rotation angle of the reflection mirror 16. In this example, the rotation angle detection device 19 detects the rotation angle of the motor 15 b, thereby making the reflection mirror 16 based on the traveling direction 8 of the automatic guided vehicle 1. It is assumed that a reflection mirror rotation angle detection result 19a representing the rotation angle is output.
[0053]
The light irradiating / receiving device 20 has a laser irradiation function and a light receiving function, and is installed directly above the reflecting mirror 16 and downward in the vehicle body vertical direction.
[0054]
The laser 5 irradiated by the light irradiating / receiving device 20 is incident on the reflecting mirror 16 downward in the vertical direction of the vehicle body and is reflected in a direction corresponding to the rotation angle of the reflecting mirror 16, so that it is radiated to the outside of the vehicle body. Further, since the tilt angle changes by changing the rotation speed of the reflecting mirror 16, the irradiation direction of the laser 5 changes up and down. As a result, the conventional scanning is performed only on a flat surface, but the laser 5 is scanned in the cylindrical direction by changing the rotation speed of the reflecting mirror.
[0055]
On the other hand, either reflector 3₁3₂3_ThreeThe laser (reflected laser) 6 reflected by the laser beam returns to the reflecting mirror 16 and enters, but only the light emitted from the reflecting mirror 16 upward in the vehicle body vertical direction is received by the light irradiation / light-receiving device 20, and the reflected light received. A light receiving output 20a representing the amount of laser light is output.
[0056]
At that time, since the tilt angle of the reflecting mirror 16 changes according to the rotation speed and the laser 5 is scanned in the cylindrical direction, even when the automatic guided vehicle 1 tilts, the reflecting mirror 16 has any tilt angle. Sometimes the laser 5 is reflected by the reflector and the reflected laser 6 can be received.
[0057]
The reflected light presence / absence detecting device 21 detects the presence / absence of the reflected laser 6 from the light reception output 20a of the light irradiation / light receiving device 20 by an appropriate peak detection method such as a method using comparison with a threshold value or a method using differential operation. The reflected light presence / absence detection result 21a is output.
[0058]
The tilt angle detection device 22 detects the tilt angle of the reflecting mirror 16, and in this example, a correspondence between the rotational speed of the motor 15b and the tilt angle of the reflecting mirror 16 is obtained in advance, and a table representing this is preliminarily obtained. By setting and detecting the rotational speed of the motor 15b and referring to the table, an inclination angle detection result 22a representing the inclination angle of the reflecting mirror 16 with respect to the horizontal plane of the vehicle body is obtained and output.
[0059]
Here, the relationship between the reflected light presence / absence detection result 21a of the reflected light presence / absence detection device 21, the reflection mirror rotation angle detection result 19a of the rotation angle detection device 19, and the reflection mirror tilt angle detection result 22a of the tilt angle detection device 22 is as follows. As shown in FIG.
[0060]
That is, graphs as shown in FIGS. 6A to 6E are obtained by using the tilt angle of the reflecting mirror 16 with respect to the horizontal plane of the vehicle body as a parameter, the rotating angle of the reflecting mirror on the horizontal axis, and the presence or absence of reflected light on the vertical axis. Is obtained. θ₁, Θ₂, Θ_ThreeIs the rotation angle of the reflecting mirror when the reflection laser 6 is present, and represents the direction of the reflector as viewed from the automatic guided vehicle 1 with reference to the traveling direction 8 of the automatic guided vehicle 1.
[0061]
FIG. 6A is a graph in the case where the reflecting mirror 16 is inclined 45 degrees, and therefore the laser 5 is irradiated horizontally, and the lower end side reflecting portion 3 of all the reflecting plates.₁-B, 3₂-B, 3_ThreeThe laser beam 5 is reflected by -B, and the reflected laser beam 6 is received. That is, all reflector directions θ are not affected by any non-reflecting part.₁, Θ₂, Θ_ThreeCan be detected.
[0062]
FIG. 6B is a graph in the case where the reflecting mirror 16 is inclined 45.5 degrees, and therefore the laser 5 is irradiated 1 degree above the horizontal. The laser 5 is not reflected from the two reflecting plates 3.₁-1, 3_ThreeAlthough it is not reflected when it hits -1, the reflection part 3 at its upper end side is reflected from one reflector._ThreeThe state where the laser 5 is reflected by -T and the reflected laser 6 is received is shown. That is, reflector direction θ₂Only that it can be detected.
[0063]
FIG. 6C is a graph in the case where the reflecting mirror 16 is tilted 46 degrees, and therefore the laser 5 is irradiated 2 degrees above the horizontal, and the upper-end reflecting portion 3 of each reflecting plate.₁-T, lower end side reflection part 3₂-B, intermediate reflection part 3_ThreeThe laser 5 is reflected by -M, and the reflected laser 6 is received. That is, all reflector directions θ are not affected by any non-reflecting part.₁, Θ₂, Θ_ThreeCan be detected.
[0064]
FIG. 6D is a graph when the reflecting mirror 16 is tilted 46.5 degrees, and therefore the laser 5 is irradiated 3 degrees above the horizontal, and the laser 5 is not reflected from the two reflecting plates.₂-1, 3_Three-2 is not reflected, but from one reflector, its upper reflection part 3₁The state where the laser 5 is reflected by -T and the reflected laser 6 is received is shown. That is, reflector direction θ₁Only that it can be detected.
[0065]
FIG. 6E is a graph in the case where the reflecting mirror 16 is inclined by 47 degrees, and therefore the laser 5 is irradiated 4 degrees above the horizontal, and the upper end side reflecting portion 3 of all the reflecting plates.₁-T, 3₂-T, 3_ThreeThe laser 5 is reflected by -T and the reflected laser 6 is received. That is, all reflector directions θ are not affected by any non-reflecting part.₁, Θ₂, Θ_ThreeCan be detected.
[0066]
The reflector detection device 23 includes a reflected light presence / absence detection result 21a of the reflected light presence / absence detection device 21, a reflection mirror rotation angle detection result 19a of the rotation angle detection device 19, and a reflection mirror tilt angle detection result 22a of the tilt angle detection device 22. And each reflector 3 stored in the second storage area 14-2 of the memory 14₁, 3₂ 3_Three Based on the pattern information of the reflective part and the non-reflective part and the length information in the vertical direction of the reflective plate stored in the third storage area 14-3, detection of the reflective plate direction, identification of the reflective plate, and unmanned conveyance Calculate the distance from the car to the reflector.
[0067]
In this example, in the reflector detection device 23, the reflector direction detector 24 is responsible for detecting the reflector direction, the reflector identifier 25 is responsible for identifying the reflector, and the distance calculator 26 is up to the reflector. The distance calculation is shared.
[0068]
Specifically, the reflector direction detection unit 24 inputs the reflected light presence / absence detection result 21a and the reflection mirror rotation angle detection result 19a, and for each time the reflection laser 6 is present, the reflection mirror rotation angle at that time. By examining the (laser irradiation direction) from the rotation angle detection result 19a, the reflection plate direction detection result 9 is output.
[0069]
For example, as shown in FIG. 10, each reflecting plate direction 7 viewed from the automatic guided vehicle 1.₁, 7₂, 7_ThreeAngle θ with respect to the direction of travel 8 of the automatic guided vehicle 1₁, Θ₂, Θ_ThreeWhich direction (angle θ) is viewed from the automatic guided vehicle 1 as shown in FIG.₁, Θ₂, Θ_Three) To obtain a reflection plate direction detection result 9 indicating whether a reflection plate is present.
[0070]
In this reflector direction detection, the tilt angle of the reflecting mirror 16 changes and the laser 5 rotates and scans in a cylindrical shape. Therefore, as can be seen from the graphs of FIGS. Reflector 3 even if tilted₁3₂3_ThreeIs not out of the rotational scanning range of light, and all reflector directions θ₁, Θ₂, Θ_ThreeCan be detected.
[0071]
The reflector identifying unit 25 inputs the reflector direction detection result 9, the reflected light presence / absence detection result 21a, the reflector rotation angle detection result 19a, and the reflector tilt angle detection result 22a, and the reflection laser 6 is present. The same reflector direction detection angle θ from the reflector tilt angle at the time and the reflector tilt angle when there is not_nFor each (n = 1, 2, 3), a pattern representing the relationship between the tilt angle of the reflecting mirror and the presence or absence of reflected light is created, and the reflection part and the non-reflection part stored in this pattern and the second storage area 14-2 are created. By comparing the patterns and looking for a good match, the angle θ_nWhich reflector 3 in the direction of_nWhether or not (n = 1, 2, 3) exists is identified, and a reflector identification result 25a is output.
[0072]
The reason why the reflector can be identified is that, as can be seen from the graphs of FIGS. 6A to 6E, even with the same reflector, there is a reflection laser 6 depending on the tilt angle of the reflector, There is no, but the state of each reflector 3_1,3_2,3_ThreeThis is because it corresponds to the pattern of the reflection part and the non-reflection part.
[0073]
That is, by referring to the pattern information of the reflecting part and the non-reflecting part by changing the reflecting mirror tilt angle with a somewhat high resolution, from the relationship between the reflected light presence / absence detection result 21a and the reflecting mirror tilt angle detection result 22a, It is possible to identify which reflector has detected the reflector direction.
[0074]
The distance calculation unit 26 inputs the reflection plate identification result 25a, the reflected light presence / absence detection result 21a, the reflection mirror rotation angle detection result 19a, and the reflection mirror tilt angle detection result 22a, and the same reflection plate 3 is input._nReflector tilt angle φ when the reflected laser 6 starts to be detected every (n = 1, 2, 3)_bnAnd the tilt angle φ of the reflector when the reflection laser 6 is detected_enCheck out. And the difference Δφ_n(= | Φ_bn−φ_en|) And the reflector 3 stored in the third storage area 14-3_nL length in the vertical direction_nUsing (n = 1, 2, 3), the formula X_n= L_n/ Tan (2Δφ_n)_nReflector 3 present in the direction of_nDistance X to (n = 1,2,3)_nAnd the distance calculation result 26a is output. Formula X_n= L_n/ Tan (2 | φ_bn−φ_en|) For distance X_nCan also be calculated.
[0075]
The reason why the distance can be calculated is that, as can be seen from the graphs of FIGS. 6A to 6E, by changing the tilt angle of the reflecting mirror with a somewhat high resolution, the reflecting portions on the lower end side of all the reflecting plates. 3₁-B, 3₂-B, 3_ThreeReflector 3 on the upper end side from -B₁-T, 3₂-T, 3_ThreeThis is because the reflected laser 6 can be detected from -T.
[0076]
That is, each reflector 3_nFor (n = 1,2,3), the lower reflection part 3_nThe angle of inclination of the reflector when the reflected laser 6 from -B is detected is φ_bn, Upper end side reflection part 3_nThe angle of inclination of the reflecting mirror when the reflected laser 6 from -T is detected is φ_enThen, the difference Δφ_n(= Φ_bn−φ_en) And the length L of each reflector in the vertical direction_nAnd the distance X of each reflector from the automatic guided vehicle 1_nX_ntan (2Δφ_n) = X_ntan 2 (φ_bn−φ_en) = L_nThere is a relationship. Accordingly, if the resolution of the reflecting mirror tilt angle is sufficient, in the example shown in FIG._nDistance X to_nIs the vertical length L of each reflector_nBy referring to_n= L_n/ Tan (2Δφ_nOr X_n= L_n/ Tan 2 (φ_bn−φ_en). Φ_bnAnd φ_enThe magnitude relation of is φ when the tilt angle is changed while the reflecting mirror 16 is stopped or rotated at a high speed from a low speed to a high speed._bn> Φ_enHowever, when changing the tilt angle while rotating at a reduced speed from high speed to stop or low speed, φ_bn<Φ_enTherefore, in general, Δφ_n= | Φ_bn−φ_en|
[0077]
The following two types of position calculation device 27 are conceivable.
(1) Based on the reflection plate direction detection result 9, the reflection plate identification result 25a, and the reflection plate position information such as the reflection plate distribution map 10 stored in the first storage area 14-1, the position of the automatic guided vehicle 1 is determined. The position calculation device to find.
(2) Based on the reflector direction detection result 9, the reflector identification result 25a, the distance calculation result 26a, and the reflector position information such as the reflector distribution map 10 stored in the first storage area 14-1, unmanned A position calculation device for determining the position of the transport vehicle 1.
[0078]
The reason why such two kinds of position calculation devices can be adopted is as follows.
[0079]
Assuming that all the reflectors are substantially equidistant, the reflector direction detection result 9 and the first storage area 14 − are obtained even when the automatic guided vehicle 1 is slightly inclined due to the change in the inclination angle of the reflector 16. The position 11 and the traveling direction 12 of the automatic guided vehicle 1 can also be obtained by the conventional method based on only the reflector position information stored in 1 (see FIG. 13). The same applies to the case where each reflecting plate has no non-reflecting portion.
[0080]
However, since the reflecting plate can be identified by utilizing the fact that the pattern of the reflecting portion and the non-reflecting portion is different between the reflecting plates, the reflecting plate identification result 25a can be used to determine which reflecting plate exists in which direction. .
[0081]
Therefore, in the first position calculation device 27, which reflector 3 is viewed from the automatic guided vehicle 1 based on the reflector direction detection result 9 and the reflector identification result 25 a.₁, 3₂, 3_Three Which direction θ₁, θ₂, θ_ThreeThe information (3)₁, θ₁) (3₂, θ₂) (3_Three, θ_Three) And the reflecting plate position information such as the reflecting plate distribution map 10 or the like, the position and traveling direction of the automatic guided vehicle 1 can be detected with high accuracy even if the reflecting plate distance is unknown and different. Thereby, it becomes possible to prevent erroneous detection of the position without specially devising the distribution of the reflector.
[0082]
Furthermore, since the distance to the reflecting plate can be calculated by using the reflecting portions at the upper and lower ends of the reflecting plate, if both the reflecting plate identification result 25a and the distance calculating result 26a are used, which reflecting plate is approximately in which direction. You can see how far it exists.
[0083]
Therefore, in the second position calculation device 27, which reflector 3 is seen from the automatic guided vehicle 1 based on the reflector direction detection result 9, the reflector identification result 25a, and the distance calculation result 26a.₁, 3₂, 3_Three Which direction θ₁, θ₂, θ_ThreeHow much distance X₁, X₂, X_ThreeTo find out if this exists (3₁, θ₁, X₁) (3₂, θ₂, X₂) (3_Three, θ_Three, X_Three) And the position information of the reflecting plate such as the reflecting plate distribution map 10 or the like, the position and traveling direction of the automatic guided vehicle 1 can be detected with higher accuracy even if the distance between the reflecting plates is different. Thereby, it becomes possible to prevent erroneous detection of the position without specially devising the distribution of the reflector.
[0084]
【The invention's effect】
  According to the first aspect of the present invention, since the position detecting reflector has the reflecting portion and the non-reflecting portion formed by dividing the reflecting plate in the vertical direction in different patterns, the light is rotated and scanned in a cylindrical shape. Thus, it is possible to detect the reflector direction and recognize the reflector, which reflector is in which direction.Further, the mirror is supported so that the tilt angle thereof is changed by the centrifugal force and the rotation speed of the reflection plate is changed, so that the light is rotationally scanned in a cylindrical shape and stored in advance in addition to the position information of the reflection plate. Using the pattern information of the reflective part and non-reflective part, the position of the automatic guided vehicle is detected by detecting the direction of the reflective plate, which reflector is in which direction, and recognizing the reflective plate. The accuracy of. Therefore, erroneous detection of the position can be prevented without specially devising the distribution of the reflector. In addition, since the light is rotationally scanned in a cylindrical shape, the reflecting plate is not deviated from the rotational scanning range of the light when the automatic guided vehicle is tilted.
[0085]
  According to the invention of claim 2, the position detecting reflector has not only a reflecting part and a non-reflecting part that are formed by dividing the reflecting plate in the longitudinal direction in different patterns from each other, and further, both ends in the longitudinal direction. Since there is always a reflection part, if the light is rotated and scanned into a cylindrical shape and irradiated, detection of the reflection plate direction and recognition of the reflection plate, which reflection plate exists in which direction and at what distance And all distance calculations are possible.Furthermore, by supporting the reflecting mirror so that its inclination angle changes due to centrifugal force and changing the rotating speed of the reflecting plate, the light is rotated and scanned in a cylindrical shape, and the position information of the reflecting plate and the reflecting part and the non-reflecting part are reflected. In addition to the pattern information of the part, the length information in the longitudinal direction of the reflecting plate stored in advance is used to detect which reflecting plate is present in which direction and at what distance, the reflecting plate direction Since the position of the automatic guided vehicle is detected by performing the recognition and the distance calculation, the accuracy of the position detection is further increased. Therefore, erroneous detection of the position can be prevented. In this case as well, since the light is rotationally scanned in a cylindrical shape, the reflecting plate is not deviated from the rotational scanning range of the light when the automatic guided vehicle is tilted.
[0088]
  Claim3According to the invention, since the reflecting mirror is supported by the elastic member and the swinging supporting member so that the inclination angle thereof is changed by the centrifugal force, the supporting mechanism of the reflecting mirror is simple.
[0089]
  Claim4According to the invention relating to the above, since the center of gravity of the reflecting mirror is deviated from the rotation center axis, the inclination angle of the reflecting mirror can be easily changed by the centrifugal force.
[0090]
  Claim5According to the invention according to, since there is a weight at a position away from the rotation center axis of the reflecting mirror, the tilt angle of the reflecting mirror can be changed more easily.
[Brief description of the drawings]
FIG. 1 is a view showing an arrangement of reflectors according to an embodiment of the present invention.
FIG. 2 is a view showing a pattern example of a reflecting portion and a non-reflecting portion in a reflecting plate.
FIG. 3 is a diagram showing a configuration of a position detection device according to an embodiment of the present invention.
FIG. 4 is a view showing a structural example of a reflecting mirror support device.
FIG. 5 is a diagram showing the relationship between the rotation speed of the reflecting mirror and the change in the tilt angle.
FIG. 6 is a diagram showing the relationship between the mirror rotation angle and the presence or absence of reflected light, using the mirror tilt angle as a parameter.
FIG. 7 is an explanatory diagram for calculating the distance from the automatic guided vehicle to the reflecting plate.
FIG. 8 is a diagram illustrating a guided method for an automatic guided vehicle based on position detection using a reflector.
FIG. 9 is a diagram showing the relationship between the presence / absence of a reflector and the reflected laser.
FIG. 10 is a diagram showing the direction of the reflector as viewed from the automatic guided vehicle.
FIG. 11 is a diagram illustrating an example of a detection result of a reflecting plate direction.
FIG. 12 is a diagram showing an example of a reflector distribution map.
FIG. 13 is a diagram showing a search result of the position and traveling direction of the automatic guided vehicle on the reflector distribution map.
FIG. 14 is a diagram illustrating a conventional configuration example of a position detection device.
FIG. 15 is a diagram illustrating a relationship between a mirror rotation angle, a light reception output, and the presence or absence of reflected light.
[Explanation of symbols]
1 Automated guided vehicle
2 moving area
3₁3₂3_Three  a reflector
3₁-1, 3₂-1, 3_Three-1, 3_Three-2 Non-reflective part
3₁-T, 3₂-T, 3_Three-T Reflector on the upper end side
3₁-B, 3₂-B, 3_Three-B Reflection part at the lower end
3_Three-M Middle reflector
4 Position detection device
5 Laser
6 Reflection laser
7₁, 7₂, 7_Three  Reflector direction as seen from automated guided vehicle
8 Traveling direction of automatic guided vehicle
9 Reflector direction detection results
10 Reflector distribution map (Reflector position information)
11 Position on the reflector distribution map
12 Direction starting from the position on the reflector distribution map
13₁, 13₂, 13_Three  Reflector direction on the reflector distribution map
14 memory
14-1 First memory area
14-2 Second memory area
14-3 Third memory area
15 Rotating device
15a stage
15b motor
15c protrusion
16 Reflector
16a weight
17 Reflector support device
17a hinge
17b Spring
18 Speed change device
19 Rotation angle detector
19a Reflector rotation angle detection result
20 Light irradiation and light receiving device
20a Light reception output
21 Inclination angle detector
21a Reflector tilt angle detection result
22 Reflected light presence / absence detection device
22a Detection result of reflected light
23 Reflector detection device
24 Reflector direction detector
25 Reflector identification part
25a Reflector identification result
26 Distance calculator
26a Distance calculation result
27 Position calculator
28₁, 28₂, 28_Three  Conventional reflector
29 Conventional reflector direction detection device
30 Conventional position calculation device

Claims

Position information of a reflector having a reflecting part and a non-reflecting part, which are erected at a plurality of locations in the driving environment of the automatic guided vehicle and are divided in the vertical direction in different patterns , and the reflection part and the non-reflecting part A storage device that stores pattern information in advance, a reflecting mirror, a rotating device that rotates the reflecting mirror, and the reflecting mirror are supported in an inclined state, and the inclination angle is supported so as to be changed by centrifugal force. A reflecting mirror support device, a speed changing device that changes the rotational speed of the reflecting plate, a light irradiation / light receiving device that is installed downward and that irradiates light to the reflecting mirror and receives light from the reflecting mirror; and Reflected light presence / absence detecting device for detecting the presence / absence of reflected light from the light receiving output of the light irradiation / light receiving device, a rotation angle detecting device for detecting the rotation angle of the reflecting mirror, and an inclination angle detection for detecting the tilt angle of the reflecting mirror Device and said anti Based on the detection result of the light presence / absence detection device, the detection result of the rotation angle detection device, the detection result of the tilt angle detection device, and the pattern information of the reflective portion and the non-reflective portion of each reflector stored in the storage device Te, a reflector direction of the detection and the reflection plate detection apparatus which performs identification of the reflector, and results reflector direction detection result and the reflection plate identification of the reflector detecting apparatus, each reflector is stored in the storage device A position detection device for an automatic guided vehicle comprising a position calculation device for obtaining the position of the automatic guided vehicle based on position information.

Position information of reflectors which are erected at a plurality of locations in the driving environment of the automated guided vehicle and have a reflecting portion and a non-reflecting portion which are formed in different vertical patterns and are always provided with reflecting portions at both ends in the vertical direction. In a state where the pattern information of the reflecting part and the non-reflecting part and the length information in the vertical direction are stored in advance, the reflecting mirror, the rotating device that rotates the reflecting mirror, and the reflecting mirror in an inclined state A reflector support device that supports and supports the tilt angle to be changed by a centrifugal force, a speed change device that changes the rotational speed of the reflector, and a light irradiation to the reflector that is installed downward. And a light irradiation / light-receiving device that receives light from the reflecting mirror, a reflected light presence / absence detecting device that detects the presence / absence of reflected light from the light-receiving output of the light irradiation / light-receiving device, and a rotation angle of the reflecting mirror With rotation angle detector An inclination angle detection device that detects an inclination angle of the reflecting mirror, a detection result of the reflected light presence / absence detection device, a detection result of the rotation angle detection device, a detection result of the inclination angle detection device, and stored in the storage device Based on the pattern information of the reflecting part and the non-reflecting part of each reflecting plate and the length information in the vertical direction of the reflecting plate stored in the storage device, the detection of the reflecting plate direction, the identification of the reflecting plate, and the automatic guided vehicle from a reflector detecting apparatus for calculating the distance to the reflecting plate, the reflecting plate direction detection result of the reflection plate detection device, and results reflecting plate identification result and distance calculation, for each reflector is stored in the storage device A position detection device for an automatic guided vehicle comprising a position calculation device for obtaining the position of the automatic guided vehicle based on position information.

The reflecting mirror supporting device and an elastic member supporting the one upper or lower reflector, an upper and lower other of the reflector and having a swing support member that swingably supported claim 1 or 2 The position detection apparatus of the automatic guided vehicle described in 1.

The position detection device of the automatic guided vehicle according to claim 3 , wherein a center of gravity of the reflecting mirror is deviated from a rotation center axis.

The position detection device of the automatic guided vehicle according to claim 4 , wherein a weight is provided at a position away from a rotation center axis of the reflecting mirror.