JP3656332B2

JP3656332B2 - Unmanned work method by unmanned working vehicle

Info

Publication number: JP3656332B2
Application number: JP22704696A
Authority: JP
Inventors: 修行本; 陽介松尾; 克也油田; 伸野口
Original assignee: 独立行政法人農業・生物系特定産業技術研究機構
Priority date: 1996-08-28
Filing date: 1996-08-28
Publication date: 2005-06-08
Anticipated expiration: 2016-08-28
Also published as: JPH1066405A

Description

【０００１】
【発明の属する技術分野】
本発明の作業車両の無人走行による無人作業方法は、トラクタ等の作業車両を無人走行させて、圃場、建設現場、土木作業現場等の所定区画の作業現場を、所望の状態に耕作、整地等するのに利用できる。特に、上記作業車両を無人走行させるための案内（ガイドレール）がなく、作業の種類や作業経路が種々存在する作業分野において、有効に利用できるものである。
【０００２】
【従来の技術】
例えば、トラクタにより圃場内を耕作する場合、作業者の負担を軽減すべく、このトラクタを無人運転させて当該圃場を耕作する（無人作業を行う）ことが、従来から考えられ、又、実施されている。例えば、本出願人が平成８年２月に発行した「平成７年度事業報告」には、上記トラクタ等の作業車両の圃場内における位置や走行方位を検出し、これら検出値に基づいて上記作業車両を無人走行させ、無人作業を行う方法が記載されている。
このような従来の無人作業方法においては、圃場の周辺部をマニュアル運転（作業者が運転することによる走行。以下、ティーチング走行とする。）することによって得られる学習データ、或いは、前作業（これから行おうとする作業よりも以前に行った、当該作業現場における作業）の記録データにより得られる、圃場区画や基準走行方位（本発明を表す図１に示すφi）の情報に基づいて作業経路を設定し、時々刻々得られる車両位置や走行方位情報をフィードバックする等により、上記作業車両に上記設定した作業経路上を無人走行させ、無人作業を行う。
上述したような従来方法によれば、作業車両の無人走行により無人作業を行え、作業の自動化を図れる。
【０００３】
【発明が解決しようとする課題】
ところで、作業現場である圃場区画、或いは作業車両の基準となる走行方位、若しくは圃場への出入り口は、圃場によって異なる。又、作業幅や旋回のための枕地の大きさは、使用する作業車両の全長等の諸元によって異なる。従って、無人作業を行うための作業経路を設定する際には、上述したような種々の条件を考慮することが、作業を確実に行う上で必要である。更に、上記ティーチング走行等により取得した圃場区画や基準走行方位の情報に基づいて上記作業経路を設定する場合に、作業開始位置と終了位置とを考慮するとともに、適切な作業重複幅を確保することが、作業を効率良く行う上で必要である。
【０００４】
更に、作業を確実に効率良く行うためには、上述した事項に加え、作業車両が作業現場外へはみ出したり、既に作業を終えた区域（既作業域）を踏み付け足りすることを防止する必要がある。このためには、上記作業車両の旋回や幅寄せを勘案して、この作業車両の無人走行を高精度で行わなければならない。前述した従来方法においては、上述した各種条件を勘案したものではなかった。
【０００５】
本発明の作業車両の無人走行による無人作業方法は、上述のような事情に鑑みて発明したもので、作業車両の高精度な無人走行を行えるようにすることで、この作業車両による作業を、正確で効率良く行えるようにするものである。
【０００６】
【課題を解決するための手段】
本発明の作業車両の無人走行による無人作業方法は、所定の作業を行う作業車両を所定区画の作業現場内で無人走行させることにより、この作業現場内に上記所定の作業を施す、作業車両の無人走行による無人作業方法に関する。このような本発明の作業車両の無人走行による無人作業方法においては、上記作業を、作業現場の中央部を、枕地での１８０度旋回を行って直進作業を繰り返す往復直進作業と、この往復直進作業が行われる上記中央部を除く周辺部を回行し、枕地処理を含む処理を行う回り作業とに区分し、これら往復直進作業と回り作業とをそれぞれ行うべく、それぞれの作業経路を定めた、以下の（ａ）〜（ｄ）の要件を備える制御プログラムを作成する。
（ａ）上記往復直進作業と回り作業との優先順位（ｂ）上記作業車両の諸元を含む条件に基づく、上記往復直進作業の開始点から終了点に至る折り返し行程数（ｃ）同じく上記作業車両の諸元を含む条件に基づく、上記回り作業の開始点から終了点に至る周回数（ｄ）上記所定の作業の開始及び終了に際し、上記作業車両を、この作業車両が位置する地点から目的とする地点に移動させる移動経路。一方、上記作業車両には、この作業車両の位置を検出する位置検出手段と、この作業車両の走行方向を検出する方位検出手段とを備える。そして、作業車両の上記作業現場内の走行時には、上記位置検出手段と方位検出手段とによって時々刻々得られる位置情報と方位情報とに基づいて、例えば、この作業車両が有する直進制御手段や回行制御手段が制御されつつ、上記制御プログラムに定められた上記作業経路に沿って無人走行することにより、上記所定の作業を行う。そして、上記作業車両に付与した舵角と、この舵角を付与することに伴う作業車両の位置情報及び方位情報のそれぞれの変化量とにより、作業車両に付与される舵角と得られる作業車両の旋回半径との関係式を求め、この関係式に基づいて上記往復直進作業時又は上記回り作業時における作業車両の舵角を制御するものである。
【０００７】
また、本発明は、前述の特徴に加えて、上記作業車両に付与される舵角と得られる作業車両の旋回半径との関係式を、作業の進行によって逐時得られる上記舵角と上記旋回半径との関係を学習することにより、修正及び更新し、適正な舵角と旋回半径の関係を得られるようにしたものである。
【０００８】
また、本発明は、前述の特徴に加えて、上記作業車両の走行状態を、直進走行ステージと、１８０度旋回ステージと、任意角度旋回ステージと、幅寄せステージとの４つのステージに区分し、上記位置検出手段と方位検出手段とによって時々刻々得られる位置情報と方位情報とに基づき、これら各ステージを適宣選択する場合に、上記任意角度旋回ステージにおいて、作業車両の車輪が、作業現場外或いは既作業域へ進入することを防止すべく、作業現場に関する情報及び作業車両の諸元並びに作業車両の操舵角と旋回半径との関係から、このステージの開始点から前進旋回を行った場合の前車輪の到達位置や、周囲の既作業域までの距離を演算し、それらの位置や距離に基づき、必要に応じて、作業車両の舵角を付与しない状態での後進或いは舵角を付与した状態での後進を予め行い、この後、上記方位情報に基づく旋回を行うものである。
【００１０】
また、本発明は、前述の特徴に加えて、上記幅寄せステージにおいて、このステージの開始点より幅寄せの目標終了点が前方にある場合で、必要幅寄せ量を前方向移動量で除した前方幅寄せ比を演算し、その比がある定数以上の場合は、予め後進幅寄せにより必要な幅寄せの一部を行った後に前進幅寄せを行って必要な幅寄せを完了し、その比がある定数以下の場合は、前進幅寄せのみにより必要な幅寄せを完了する、また、このステージの開始点より幅寄せの目標終了点が後方にある場合で、必要幅寄せ量を後方向移動量で除した後方幅寄せ比を演算し、その比がある定数以上の場合は、予め前進幅寄せにより必要な幅寄せの一部を行った後に後進幅寄せを行って必要な幅寄せを完了し、その比がある定数以下の場合は、後進幅寄せのみにより必要な幅寄せを完了するものである。
【００１１】
【作用】
本発明の作業車両の無人走行による無人作業方法は、上述のように構成されるため、圃場等の作業現場をトラクタ等の作業車両の無人走行によって無人作業を行う場合に、この圃場の耕作等の作業を確実に行うことができる。すなわち、本発明の方法によれば、上記作業を、作業現場の中央部を、枕地での１８０度旋回を行って直進作業を繰り返す往復直進作業と、この往復直進作業が行われる上記中央部を除く周辺部を回行し、枕地処理を含む処理を行う回り作業とに区分する。そして、これら往復直進作業と回り作業とをそれぞれ行うべく、
（ａ）上記往復直進作業と回り作業との優先順位
（ｂ）上記作業車両の諸元を含む条件に基づく、上記往復直進作業の開始点から終了点に至る折り返し行程数
（ｃ）同じく上記作業車両の諸元を含む条件に基づく上記回り作業の開始点から終了点に至る周回数
（ｄ）上記所定の作業の開始及び終了に際し、上記作業車両を、この作業車両が位置する地点から目的とする地点に移動させる移動経路
を含む制御プログラムを定める。作業車両は、この制御プログラムに沿って無人走行し、無人作業を行う。
【００１２】
このように、本発明においては、作業現場の形状や面積、作業車両の基準となる走行方位、作業現場への出入り口等の各種条件を勘案した状態で、制御プログラムを定めるため、確実な作業が可能になる。更に、往復直進作業及び回り作業におけるそれぞれの作業経路を、作業に先立って行われるティーチング走行により、作業現場の周辺部を少なくとも１周することにより得られる学習走行データと、前作業における記録により得られたデータとの少なくとも一方のデータに基づいて設定したり、往復直進作業を先順位とし、回り作業を後順位として、この回り作業の開始点を、作業現場の出入り口に最も近い角部近傍とすることにより、上述したような各種条件に加えて上記所定の作業の作業開始位置と終了位置とを考慮できて、作業の確実化、効率化を図れる。又、上記往復直進作業の折り返し行程数ｎ１或いは回り作業の周回数ｎ２を、適宜設定することにより、作業を効率良く行えるようになる。
【００１３】
更に、本発明に係る作業車両の無人走行による無人作業方法においては、作業車両の走行状態を、直進走行ステージと、１８０度旋回ステージと、任意角度旋回ステージと、幅寄せステージとの４つのステージに区分し、位置検出手段と方位検出手段とによって時々刻々得られる位置情報と方位情報とに基づいて、これら各ステージを適宜選択して走行するように構成ができる。このように構成することにより、上記作業車両の無人走行を高精度で行えるようになる。
【００１４】
又、作業車両に付与した舵角と、この舵角を付与することに伴う作業車両の位置情報及び方位情報のそれぞれの変化量とにより、作業車両に付与される舵角と得られる作業車両の旋回半径との関係式を求め、この関係式に基づいてそれぞれのステージにおける舵角を定めるように構成するので、作業車両が作業現場外へはみ出したり、既に作業を終えた区域を踏み付け足りすることを防止でき、作業を、確実且つ効率良く行える。特に、作業車両に付与される舵角と得られる作業車両の旋回半径との関係式を、作業の進行によって逐次得られる上記舵角と上記旋回半径との関係を学習することにより、適宜修正及び更新し、適正な操舵角を得られるようにすれば、より効果的である。
【００１５】
又、上述したように、走行状態を４つのステージに区分した場合に、これら４つのステージのうちの任意角度旋回ステージにおいて、作業車両の車輪が、作業現場外或いは既作業域への進入を防止すべく、作業現場に関する情報及び作業車両の諸元並びに作業車両の操舵角と旋回半径との関係から、舵角を付与しない状態での後進或いは舵角を付与した状態での後進を予め行い、この後、上記方位情報に基づく旋回を行ったり、幅寄せステージにおいて、このステージの開始点と目標とする終了点とから算出した幅寄せ量と前後方向移動量とに応じ、前進による幅寄せと後進による幅寄せとの少なくとも一方の幅寄せを行うように構成することができる。このように構成することにより、小さな旋回量及び短い幅寄せが可能になり、上述したように作業車両が作業現場外へはみ出したり、既に作業を終えた区域を踏み付け足りすることを防止できる。
【００１６】
これらの結果、本発明に係る作業車両の無人走行による無人作業方法を用いて、圃場等の作業現場で耕作等の作業を行う場合、作業車両の高精度な無人走行が可能になり、この作業車両による作業を確実に、且つ、効率良く行える。
【００１７】
【発明の実施の形態】
次に、本発明の実施の形態の１例について説明する。図１は、本発明に係る作業車両の無人走行による無人作業方法により、作業現場である圃場１を、作業車両であるトラクタ２により耕作する状態を示している。本例の場合、この耕作が、特許請求の範囲に記載した所定の作業である。又、図２は、本発明に係る作業車両による無人作業方法を実施するための構成例を示している。本例の構造の場合、トラクタ２と上記圃場１外の任意の位置（例えば、管理センター内）とには、それぞれＧＰＳ（Global Positioning System：衛星測位システム）受信機３と特定小電力通信装置４とを設置することにより、デファレンシャルＧＰＳシステムを構成し、上記トラクタ２上で、このトラクタ２の位置情報を得られるようにしている。又、このトラクタ２には、光ファィバジャィロ及び地磁気方位センサ５を搭載し、方位情報及び車両傾斜を検出自在としている。更に、このトラクタ２には、上記位置情報や方位情報等を収集、処理する処理装置６と、このトラクタ２の各操作部を自動制御するためのコントローラ７及びアクチュエータ８とを備えている。上記各操作部としては、図２に示すように、操舵、シャトル、制動（ブレーキ）、作業機の昇降等が存在する。上記ＧＰＳ受信機３及び特定小電力通信装置４が、特許請求の範囲に記載した位置検出手段をなし、上記光ファイバジャイロ及び地磁気方位センサ５が、特許請求の範囲に記載した方位検出手段をなす。尚、圃場１外の任意の位置に設置した自動追尾型測量装置により、圃場１内でのトラクタ２の位置を検出自在とする構成を採用することもできる。
【００１８】
上述したようなトラクタ２を無人走行させて、上記圃場１内を耕作するには、先ず、この耕作に先立って、トラクタ２の作業経路を定める制御プログラムを作成する。この制御プログラムは、上記トラクタ２が行う作業を、上記圃場１のうちの中央部１ｂを、枕地での１８０度旋回を行って直進作業を繰り返す往復直進作業と、圃場１の周辺部１ａを回行し、枕地処理を含む周辺部１ａの耕作整地処理を行う回り作業とに区分した上、（ａ）上記往復直進作業と回り作業との優先順位、（ｂ）上記作業車両の諸元を含む条件である、トラクタ２の全長Ａ、作業幅Ｗ、所望の作業重複幅ｗに基づく、上記往復直進作業の開始点から終了点に至る折り返し行程数ｎ１、（ｃ）同じく上記トラクタ２の全長Ａ、作業幅Ｗ、作業重複幅ｗに基づく上記回り作業の開始点から終了点に至る周回数ｎ２、（ｄ）上記耕作を開始する際において、上記トラクタ２が存在する位置から耕作すべき圃場１の耕作を開始する位置への移動経路、及び耕作を終了した際において、トラクタ２が存在する位置から次に耕作する圃場１の耕作を開始すべき位置への移動経路等、トラクタ２を、このトラクタ２が位置する地点から目的とする地点に移動させる移動経路を定めている。
【００１９】
尚、往復直進作業及び回り作業におけるそれぞれの作業経路は、図３に示すように、作業に先立って行われるティーチング走行により、圃場１の周辺部１ａを始点Ｐ０から終点Ｐ７まで１周することにより得られる学習走行データに基づいて設定する。或いは、これから行うべき作業よりも以前に行った、この圃場１での作業における記録により得られたデータに基づいて設定する。このデータは、フレキシブルディスク（ＦＤ）等の従来知られた各種記録媒体により保存しておく。上記作業経路の設定を、上記学習データと記録により得られたデータとの両データに基づいて設定しても良い。
【００２０】
本例の場合、耕作すべき圃場として、図３に示すような、長辺Ｌ、短辺Ｍの長方形の圃場１を考える。このような圃場１を耕作すべく、本例の制御プログラムにおいては、往復直進作業を先順位とし、回り作業を後順位とするとともに、この回り作業の開始点を、圃場１の出入り口１０に最も近い角部近傍Ｑ０とする。そして、図４（Ａ）の（１）〜（ｎ１）に示す作業経路（往復直進作業）と、同図（Ｂ）の（１０）〜（１７）に示すような作業経路（回り作業）とを設定する。これら各作業経路を設定する際、上記往復直進作業の折り返し行程数ｎ１及び回り作業の周回数ｎ２は、それぞれ、以下のように定める。すなわち、上記制御プログラムの構成要件（ｂ）である、回り作業の周回数ｎ２は、トラクタ２の作業装置を含む全長Ａと作業幅Ｗと所望の作業重複幅ｗとに基づいて、
ｎ２＝ｉｎｔ（Ａ／（Ｗ−ｗ））＋１
但し、intは商の整数部分を求める関数
により決定する。図４（Ｂ）に示す例の場合、上記周回数ｎ２は２である。
【００２１】
又、上記制御プログラムの構成要件（ｃ）である、往復直進作業の折り返し行程数ｎ１は、以下のようにして求める。すなわち、圃場１全体から、後順位である回り作業によって処理される予定の周辺部１ａを除いた中央部１ｂの短辺ｍ（図４（Ａ）参照）は、
ｍ＝Ｍ−２（ｎ２・Ｗ−（ｎ２−１）ｗ）
であり、最低確保したい作業重複幅を、上記回り作業の場合と同様、ｗとした場合に、
ｎ１＝ｉｎｔ（（ｍ＋ｗ）／（Ｗ−ｗ））＋１
但し、intは商の整数部分を求める関数
ｍは中央部１ｂの幅（短辺）
により決定する。
【００２２】
尚、上記往復直進作業の折り返し行程数ｎ１を、作業重複幅ｗが均一となるように設定したり、或いは、最終折り返し行程における作業重複幅がｗlであり、残りの折り返し行程における作業重複幅がいずれもｗdであるように設定することができる。
作業重複幅ｗが、図５（Ａ）に示すように、均一なｗiとなるよう作業経路を設定すると、その作業重複幅ｗiは、
ｗi＝（ｎ１・Ｗ−ｍ）／（ｎ１＋１））
となる。
又、上記折り返し行程数ｎ１を、図５（Ｂ）に示すように、最終折り返し行程における作業重複幅ｗがｗlであり、残りの折り返し行程における作業重複幅ｗがいずれもｗdであるように設定した場合、最終の折り返し行程と、この折り返し行程の直前の折り返し行程との作業重複幅ｗlは、
ｗl＝（Ｗ−（ｍ−（ｎ１−1)(Ｗ−ｗd)))／２
となる。
【００２３】
上述のようにして、往復直進作業及び回り作業における各作業経路を設定したならば、上記ティーチング走行終了位置Ｐ７（図３）或いは圃場１の任意位置にあるトラクタ２を、上記往復直進作業の開始位置ＰS1（図４（Ａ））まで移動させる移動経路、及び上記往復直進作業の終了位置Ｐe（図４（Ａ））から上記回り作業の開始位置ＰS2（図４（Ｂ））まで移動させる移動経路を設定する。この設定が、上記制御プログラムの構成要件（ｄ）である。
【００２４】
上述のようにして各作業経路を含む制御プログラムを定めたならば、この制御プログラムに従って上記トラクタ２を無人走行させ、圃場１を無人で耕作する。上記トラクタ２には、このトラクタ２の位置を検出するＧＰＳ受信機３及び特定小電力通信装置４と、このトラクタ２の走行方向を検出する光ファイバジャイロ及び地磁気方位センサ５とを備えている。このため、上記耕作時においては、上記ＧＰＳ受信機３及び特定小電力通信装置４と、光ファイバジャイロ及び地磁気方位センサ５とによって時々刻々得られる位置情報と方位情報とに基づいて、トラクタ２が制御され、所定の作業である耕作を、上記制御プログラムに定められた上記作業経路に沿って無人運転で行う。尚、耕作を開始する際には、上記ＧＰＳ受信機３及び特定小電力通信装置４と、光ファイバジャイロ及び地磁気方位センサ５とによって、基準となる位置Ｐi及び方位φiが与えられる。
【００２５】
更に、本例の構造の場合、上記トラクタ２の無人走行を高精度に行うべく、トラクタ２の走行状態を、図６に示すように、直進走行ステージＳＴ1と、１８０度旋回ステージＳＴ2と、任意角度旋回ステージＳＴ3と、幅寄せステージＳＴ4との４つのステージに区分し、上記位置検出手段と方位検出手段とによって時々刻々得られる位置情報と方位情報とに基づいて、これら各ステージを適宜選択制御する。すなわち、トラクタ２の走行行程のうち、往復直進作業時における直進走行と、回り作業時における圃場１の周辺部１ａ及び枕地での直進走行とを、直進走行ステージＳＴ1とし、往復直進作業時におけるＵターンを、１８０度旋回ステージＳＴ2とし、回り作業時における折り返し行程での旋回を任意角度旋回ステージＳＴ3とし、回り作業時及び往復直進作業時における旋回の後、次行程開始位置までの移動を、幅寄せステージＳＴ4とする。そして、これら４つのステージを適宜選択して、上記制御プログラムに沿った走行を行う。尚、トラクタ２が直進走行ステージＳＴ1にある場合に、耕作が行われる。
【００２６】
上記直進走行ステージＳＴ1は、トラクタ２の上記作業経路に沿った走行と、目的地点に移動すべく、基準走行方位を維持する無人走行とを対象としており、時々刻々得られる位置情報と方位情報とに基づいて舵角を制御することによって行う。例えば、時刻ｔにおけるトラクタ２の位置Ｐt及び方位φｔの、予め設定した作業経路上の目標位置及び目標方位に対する偏差を算出し、この偏差をなくすように、トラクタ２を操向する操舵角を求めて時々刻々の舵角制御を行う。
【００２７】
又、１８０度旋回ステージＳＴ2は、直進往復作業を行う場合における旋回を対象としており、方位情報に基づき、トラクタ２の向きが１８０度変わるまで大舵角で、適宜片ブレーキを使用することにより、旋回することによって行う。
【００２８】
任意角度旋回ステージＳＴ3は、回り作業における旋回を対象にしており、基本的には、方位情報に基づき、トラクタ２の向きが任意角度変わるまで大舵角で、適宜片ブレーキ使用により旋回することによって行う。但し、この旋回では、トラクタ２の車輪が圃場１外へはみ出したり、既に作業を終えた区域（既作業域）に進入することがないように、位置情報と方位情報とに基づき、旋回の開始地点や目標終了地点、圃場１の区画境界や既作業域の位置関係を求め、舵角を与えない後進（以下、後進Ｍｒとする）と、舵角を与えての後進（以下、後進Ｍｒｔとする）との少なくとも一方を予め行い、その後に方位情報に基づく任意角度の旋回（以下、Ｍｔとする）を行う。
【００２９】
例えば、図７（Ａ）に示すように、旋回開始地点ＰS3において前方（図７（Ａ）の上方）及び旋回外側の側方（図７（Ａ）の右方）に圃場1の区画境界が近い場合、或いは後方に直前に行った作業域（既作業域）がある場合は、先ず、トラクタ２の現在位置（旋回開始位置）ＰS3から、前方の区画境界までの距離ｄfs3を求める。次に、図７（Ｂ）に示すように、上記現在位置から前進旋回を行った場合の旋回外側の前車輪の最大到達位置ｄfmaxを、以下の式により求める。
ｄfmax＝√（（Ｒ＋ｌf・sinα)２＋(ｌf・cosα)２）
尚、上記式中、Ｒは大舵角での旋回の旋回半径、ｌfは前車輪外側の後車軸中心の中央からの距離、αは車両中心線とのなす角である。
【００３０】
ここで、図７（Ｂ）に示す距離ｔs3が、ｔs3＝ｄfmax−ｄfs3≦０であれば、上記現在位置から前進旋回を行っても前方の区画境界から前車輪がはみ出すことはない。
一方、上記距離ｔs3が、ｔs3＞０であれば、図７（Ｂ）に示すように、この距離ｔs3が、前車輪が前方の区画境界からはみ出す、はみ出し量となる。この場合において、後車軸中心から、直前に行った作業の作業域終端までの距離をｌw、後車軸中心の中央から後車輪外側までの距離をｌr（図７（Ａ）参照）として、ｔs3≦ｌwであるならば、図７（Ｃ）に示すように、上記現在位置から真後ろに距離ｔs3だけ後進Ｍｒした後に前進旋回を行うことで、前方の区画境界から前車輪がはみ出すことを防止できる。又、ｔs3＞ｌwであれば、図７（Ｄ）に示すように、先ず、適当量の舵角βを与えて後進Ｍｒｔし、トラクタ２を旋回方向に角度δだけ回動させることを考える。トラクタ２の向きを角度δだけ回動させた場合に、側方の区画境界からの後車輪のはみ出しがないように、現在位置から側方の区画境界までの距離ｄs3と、舵角βを与えた際の旋回半径Ｒβとを基に、次式から角度δの限界値δ1を求める。
Ｒβ×(１−cosδ1)＝ｄs3−ｌr・cosδ1
上記舵角βを与えた状態での、トラクタ２を旋回方向に角度δ1だけ回動させる後進Ｍｒｔによる、区画境界からの前車輪のはみ出し量は、前後方向に、（Ｒ＋Ｒβ)・sinδ1だけ少なくなるから、ｔs3≦（Ｒ＋Ｒβ)・sinδlならば、
ｔs3＝（Ｒ＋Ｒβ)・sinδ
を満たす角度δを求め、上記現在位置から車両の向きが角度δだけ変わるまで舵角βを与えての後進Ｍｒｔを行い、その後、前進旋回を行えば、前方の区画境界から前車輪がはみ出すことはない。ｔs3＞（Ｒ＋Ｒβ)・sinδlの場合は、前方の区画境界からの前車輪のはみ出しをなくすための後進距離ｄMrを、
ｄMr＝ｔs3−（(Ｒ＋Ｒβ)・sinδ1）
により求め、現在位置から距離ｄMrだけ、真後ろに後進Ｍｒし、その後、舵角βを与えての後進Ｍｒｔを、トラクタ２の向きが旋回方向に角度δ1だけ変わるまで行い、その後前進旋回を行えば、前方の区画境界から前車輪がはみ出すことはない。
上述のような任意旋回により、前方及び側方の区画境界からの車輪のはみ出し、及び後方の直前作業の作業域の後車輪による踏みつけを、ほぼ完全に防止できる。
【００３１】
次に、例えば図８に示すように、旋回開始地点Ｐs3において前方（図８（Ａ）の上方）及び旋回外方（図８（Ａ）の右方）、或いは、旋回内側に既作業域が迫った場合、若しくは後方に、直前に行った作業域がある場合は、図８（Ｂ）に示すように、トラクタ２の現在位置（旋回開始地点)Ps3から、適当量の舵角βを与えて、後方の作業域を後車輪が踏み付けない位置まで後進Ｍｒｔし、トラクタ２を旋回方向に角度δだけ回動させ、その後に、図８（Ｃ）に示すように、前進旋回を行う。この場合、後車軸中心から直前に行った作業の作業域終端までの距離をlw、後車軸中心の中央から後車輪外側までの距離をlr、舵角βを与えたときの旋回半径をＲβとすると、舵角βを与えての後進Ｍｒｔにより、
ｌw＝Ｒβ・sinδ＋ｌr・sinδ
となる角度δ分だけトラクタ２の向きが変わり、前方の既作業域の前車輪による踏みつけが、前方距離で、（Ｒ＋Ｒβ)・sinδだけ少なくなり、旋回内側及び旋回外側の既作業域を踏みつけることなく旋回が行われる。尚、現在位置（旋回開始地点)Ｐs3において、既に前輪が既作業域を踏みつけていることから、後進Ｍｒｔは舵角零の状態から開始し、速やかに舵角βを与えるようにすれば、既作業域をできるだけ荒らさないようにすることができる。
【００３２】
上記幅寄せステージST4では、図９に示すように、幅寄せ開始地点であるトラクタ２の現在位置Ｐs4と、幅寄せの目標終了地点である次作業の開始位置Ｐes4との関係から、必要な幅寄せ量ｄと前方移動量ｅf或いは後方移動量ｅrを算出し、前進による幅寄せＭsf或いは後進による幅寄せＭsr、若しくはこれらを組み合わせた幅寄せを、適宜選択し、位置情報と方位情報とに基づく幅寄せ走行を実行する。例えば、往復直進作業における１８０度旋回後の幅寄せでは、通常、次作業の開始位置（幅寄せ終了地点)Ｐes4がトラクタ２の現在位置（幅寄せ開始地点)Ｐs4より前方にあり、その前方距離ｅfと幅寄せ量ｄとの比ｄ／ｅfが基準値より小さい場合は、図９（Ａ）に示すように、距離ｅf分の前進による幅寄せＭsfによりｄの幅寄せを行う。上記比ｄ／ｅfが基準値より大きい場合は、図９（Ｂ）に示すように、例えば、距離ｅf／２分の後進による幅寄せＭsrにより、先ずｄ／３だけ幅寄せを行い、この後、距離３ｅf／２の前進による幅寄せＭsfにより、残り２ｄ／３分の幅寄せを行う。
【００３３】
一方、回り作業における旋回後の幅寄せでは、通常、次作業の開始位置（幅寄せ終了地点）Ｐes4が、トラクタ２の現在位置（幅寄せ開始地点)Ｐs4より後方にあり、その後方距離ｅrと幅寄せ量ｄとの比ｄ／ｅrが基準値よりも小さい場合は、図９（Ｃ）に示すように、距離ｅr分の後進による幅寄せＭsrにより距離ｄの幅寄せを行う。これに対して、比ｄ／ｅrが基準値より大きい場合は、図９（Ｄ）に示すように、例えば、距離ｅr／２の前進による幅寄せＭsfにより、ｄ／３だけ幅寄せを行い、この後、距離３ｅr／２の後進による幅寄せＭsrにより、残り２ｄ／３の幅寄せを行う。
【００３４】
更に、上述した各ステージにおける舵角を定める場合、トラクタ２に付与した舵角と、この舵角を付与することに伴うトラクタ２の位置情報及び方位情報のそれぞれの変化量とにより、トラクタ２に付与される舵角と得られるトラクタ２の旋回半径との関係式を求め、この関係式に基づいて上記舵角を定める。すなわち、上記各ステージにおいて、トラクタ２を制御するためのパラメータを適正に設定するために、上記ティーチング走行時、或いは位置情報と方位情報とに基づく無人作業時に、トラクタ２に与えた舵角βと、この舵角βを与えるべ行う操作や制御の結果として得られる位置情報と方位情報との変化量から、このトラクタ２に付与すべき舵角αと得られるトラクタ２の旋回半径Ｒとの関係式を求める。そして、この関係式に基づき、トラクタ２の位置や方位の修正、幅寄せ、旋回のための操舵角βの決定を行う。この場合において、トラクタ２に付与される舵角と得られるトラクタ２の旋回半径との関係式を、作業の進行によって逐次得られる上記舵角と上記旋回半径との関係を学習することにより、適宜修正及び更新し、適正な操舵角を得られるようにする。
【００３５】
例えば、図１０（Ａ）に示すような１８０度旋回、或いは同図（Ｂ）に示すような任意角度旋回において、トラクタ２の旋回前の位置及び走行方位が、それぞれＰs（Ｘs，Ｙs）、φsであり、舵角βｉを与えて旋回した後の位置及び走行方位が、それぞれＰe（Ｘe，Ｙe）、φeであった場合、旋回半径Ｒiは、式(1)或いは式(2)により求められる。尚、この場合、圃場1に直交座標を設定し、これにより上記位置を表している。
Ｒｉ＝√（（Ｘs−Ｘe）²＋（Ｙs−Ｙe）²）
φ−φ＝１８０・・・・式（１）
Ｒｉ＝√（（Ｘs−Ｘe）²＋（Ｙs−Ｙe）²）／（２sin（γ／２））
φ−φ＝α ・・・・式（２）
一方、トラクタ2の前車軸と後車軸との距離である軸距や走行速度等により理論的に求められる、任意の操舵角βと旋回半径の関係式をＲ＝Ｆ（β）とすると、マニユアル運転によるティーチング走行時、或いは位置情報Ｐiと方位情報φiとに基づく無人作業時に、実際の操舵角βiと旋回半径Ｒiとの関係から、式Ｒ＝Ｆ（β）を逐次修正、更新し、その式を用いて車両を制御するために与える舵角βを決定すれば、圃場１の状況や行程に応じて常時適正なトラクタ２の制御を行うことができる。
【００３６】
上述のように構成される作業車両の無人走行による無人作業方法の流れを、図１１のフローチャートにより示す。但し、この図１１は、往復直進作業を先順位として記載しているが、作業の種類によっては、それぞれ破線で囲った往復直進作業と回り作業との順番が逆になる場合もある。上述した本例の方法を用いることにより、圃場1の耕作を、トラクタ２の無人走行により、確実に行うことができる。すなわち、本発明の方法によれば、圃場１の形状や面積、トラクタ２の基準となる走行方位、圃場1への出入り口等の各種条件を勘案した状態で、制御プログラムを定める。このため、確実な作業が可能になる。更に、上記往復直進作業の折り返し行程数ｎ１或いは回り作業の周回数ｎ２を、上述したように設定するため、作業を効率良く行えるようになる。
【００３７】
更に、本例に係る作業車両による無人作業方法においては、トラクタ２の走行状態を、直進走行ステージと、１８０度旋回ステージと、任意角度旋回ステージと、幅寄せステージとの４つのステージに区分し、位置検出手段と方位検出手段とによって時々刻々得られる位置情報と方位情報とに基づいて、適宜各ステージを選択実行する。このため、上記トラクタ２の無人走行を高精度で行えるようになる。
【００３８】
又、トラクタ２に付与した舵角と、この舵角を付与することに伴うトラクタ２の位置情報及び方位情報のそれぞれの変化量とにより、トラクタ２に付与される舵角と得られるトラクタ２の旋回半径との関係式を求め、この関係式に基づいてそれぞれのステージにおける舵角を定めるように構成しているため、トラクタ２が圃場1外へはみ出したり、既に作業を終えた区域を踏み付け足りすることを防止でき、作業を、確実且つ効率良く行える。
【００３９】
これらの結果、本発明に係る作業車両による無人作業方法を用いて圃場等の作業現場を耕作等の作業を行う場合、トラクタ２等の作業車両の高精度な無人走行が可能になり、この作業車両による作業を確実に、且つ、効率良く行える。尚、上述の例においては、トラクタ２により圃場１を耕作する場合について説明したが、本発明はこの例に限定されるものではなく、他の作業車両により圃場以外の作業現場を作業する場合にも適用できる。
【００４０】
【発明の効果】
本発明に係る作業車両による無人作業方法は、上述のように構成され作用するため、作業現場や、作業機を含む作業車両の作業幅や仕様等の条件に応じて、作業重複幅を適切に配分した効率的な作業経路を設定することができる。特に、作業開始位置と終了位置とを作業現場への出入り口に近い角部とすることにより、より効率的な作業経路を設定することができる。
又、作業車両の走行状態を４ステージに分け、各ステージを適宜組み合わせることにより、設定した作業経路上での無人走行を高精度で行うことができ、しかも、経路計画や車両制御のためのブログラムの開発、修正を容易に行うことができる。更に、作業経路上の無人走行において、旋回半径を小さく、短い距離で幅寄せを行うことが可能となり、その結果として、作業車両の車輪が区画外へはみ出したり、既作業域を踏みつけることが防止され、作業の精度、質を高めることができる。
又、直進走行、旋回、幅寄せと言った作業車両の制御を、作業現場の状況や行程に応じて適正に行うことが可能となる。この点からも、作業現場外へのはみ出しや既作業域の踏みつけをなくし、作業の精度及び質を高めることが可能となる。
【図面の簡単な説明】
【図１】本発明の実施の形態の１例を示す、作業状態時のトラクタを上方から見た図。
【図２】トラクタに設ける装置を示すブロック図。
【図３】ティーチング走行を説明するための図。
【図４】往復直進作業及び回り作業を説明するための図。
【図５】作業重複幅を設定する際の例を示す図。
【図６】走行状態を４ステージに分割した場合の、各ステージを説明するための図。
【図７】任意角旋回ステージにおける旋回状態の第1例を説明するための図。
【図８】同じく第２例を説明するための図。
【図９】幅寄せステージにおける幅寄せ状態を説明するための図。
【図１０】旋回時の制御を説明するための図。
【図１１】本発明を用いて作業を行う場合の流れを示すフローチャート。
【符号の説明】
１圃場
２トラクタ
３ＧＰＳ受信機
４特定小電力通信装置
５光ファイバジャイロ及び地磁気方位センサ
６処理装置
７コントローラ
８アクチュエータ
１０出入り口[0001]
BACKGROUND OF THE INVENTION
The unmanned operation method by unmanned operation of the work vehicle according to the present invention includes unmanned operation of a work vehicle such as a tractor, and cultivating, leveling, etc. in a desired state of a work site in a predetermined section such as a farm field, a construction site, or a civil engineering work site. Can be used to do. In particular, there is no guide (guide rail) for unmanned traveling of the work vehicle, and it can be effectively used in a work field where there are various types of work and work routes.
[0002]
[Prior art]
For example, when cultivating the field with a tractor, in order to reduce the burden on the operator, it has been conventionally considered and practiced to cultivate the field by performing unattended operation of the tractor (performing unmanned work). ing. For example, in the “FY2007 Business Report” issued in February 1996 by the present applicant, the position and traveling direction of the work vehicle such as the tractor in the field are detected, and the above work is performed based on these detected values. A method is described in which a vehicle is driven unattended and unmanned work is performed.
In such a conventional unattended operation method, learning data obtained by manually operating the periphery of the field (running by the operator, hereinafter referred to as teaching travel), or previous work (from now on) The work route is set based on the information on the field section and the reference travel direction (φi shown in FIG. 1 representing the present invention) obtained from the recorded data of the work performed before the work to be performed at the work site. Then, by feeding back the vehicle position and travel direction information obtained from time to time, the work vehicle is unmanned on the set work route to perform unmanned work.
According to the conventional method described above, unmanned work can be performed by unmanned traveling of the work vehicle, and work can be automated.
[0003]
[Problems to be solved by the invention]
By the way, the field section which is the work site, the traveling direction which becomes the reference of the work vehicle, or the doorway to the field varies depending on the field. Further, the working width and the size of the headland for turning vary depending on the specifications such as the total length of the working vehicle to be used. Therefore, when setting a work route for performing unattended work, it is necessary to consider the various conditions as described above in order to reliably perform the work. Further, when setting the work route based on the information on the field section and the reference travel direction acquired by the teaching travel, etc., the work start position and the end position are taken into consideration, and an appropriate work overlap width is secured. However, it is necessary for efficient work.
[0004]
Furthermore, in order to perform the work reliably and efficiently, in addition to the above-mentioned matters, it is necessary to prevent the work vehicle from protruding outside the work site or from stepping on the already finished work area (existing work area). is there. For this purpose, it is necessary to perform unmanned traveling of the work vehicle with high accuracy in consideration of turning and width adjustment of the work vehicle. In the conventional method described above, the above-described various conditions are not taken into consideration.
[0005]
The unmanned work method by unmanned traveling of the work vehicle of the present invention was invented in view of the above-described circumstances, and by enabling the work vehicle to perform unmanned traveling with high accuracy, It is intended to be accurate and efficient.
[0006]
[Means for Solving the Problems]
  By unmanned traveling of the work vehicle of the present inventionThe unmanned work method isThe present invention relates to an unmanned operation method by unmanned traveling of a work vehicle, in which the predetermined work is performed in the work site by unmanned travel of a work vehicle that performs a predetermined work in the work site of a predetermined section. In the unmanned work method by unmanned traveling of the work vehicle according to the present invention, the above work is performed as a reciprocating straight-ahead work that repeats a straight-ahead work by turning 180 degrees on the headland at the center of the work site. Rotate the peripheral part except the above-mentioned central part where the straight line work is performed, and divide it into the round work that performs the processing including the headland treatment, and in order to perform these reciprocal straight work and round work respectively, A control program having the following requirements (a) to (d) is created.
  (A) Priority order between the reciprocating linear operation and the revolving operation (b) The number of turn-back strokes from the start point to the end point of the reciprocating linear operation based on the conditions including the specifications of the work vehicle (c) The number of laps from the start point to the end point of the above-mentioned turning work based on the conditions including the specifications of the vehicle. (D) When starting and ending the predetermined work, the work vehicle is moved from the point where the work vehicle is located. Move route to move to.On the other hand, the work vehicle includes position detection means for detecting the position of the work vehicle and direction detection means for detecting the traveling direction of the work vehicle. Then, when the work vehicle travels within the work site, for example, based on the position information and the direction information obtained every moment by the position detection means and the direction detection means, for example, a straight-ahead control means and a roundabout that the work vehicle has While the control means is controlled, the predetermined work is performed by unmanned traveling along the work route defined in the control program.And the rudder angle given to the work vehicle and the work vehicle to be obtained by the rudder angle given to the work vehicle and the respective change amounts of the position information and the direction information of the work vehicle accompanying the giving of the rudder angle And a turning angle of the work vehicle at the time of the reciprocating straight-ahead work or the turning work is controlled based on this relational expression.
[0007]
In addition to the above-described features, the present invention provides a relational expression between the rudder angle given to the work vehicle and the turning radius of the work vehicle to be obtained. By learning the relationship with the radius, it is corrected and updated so that an appropriate relationship between the steering angle and the turning radius can be obtained.
[0008]
In addition to the above features, the present invention divides the traveling state of the work vehicle into four stages: a straight traveling stage, a 180-degree turning stage, an arbitrary angle turning stage, and a width-shifting stage, When appropriately selecting each of these stages based on the position information and the direction information obtained from time to time by the position detection means and the direction detection means, the wheel of the work vehicle is moved outside the work site in the arbitrary angle turning stage. Alternatively, in order to prevent entry into the existing work area, the information on the work site, the specifications of the work vehicle, and the relationship between the steering angle of the work vehicle and the turning radius, the case where a forward turn is made from the start point of this stage Calculates the arrival position of the front wheels and the distance to the existing work area, and based on those positions and distances, reverses the work vehicle without giving the rudder angle of the work vehicle. Performs backward in the state imparted with a steering angle in advance, thereafter, performs a pivot based on the orientation information.
[0010]
  Further, in addition to the above-described features, the present invention is such that, in the above-mentioned width adjusting stage, when the target end point of width adjusting is ahead of the start point of this stage, the necessary width adjusting amount is divided by the amount of forward movement. When the forward width adjustment ratio is calculated and the ratio is greater than a certain value, the necessary width adjustment is performed in advance after performing part of the required width adjustment in advance, and the required width adjustment is completed. If is less than a certain value, the required width adjustment is completed only by forward width adjustment, and the required width adjustment amount is moved backward when the target end point of the width adjustment is behind the start point of this stage. Calculate the rearward width-dividing ratio divided by the amount, and if the ratio is greater than a certain constant, perform the required width-shifting in advance after performing part of the required width-shifting in advance, and complete the required width-shifting. However, if the ratio is less than a certain constant, only reverse shifting Ri is intended to complete the lateral move necessary.
[0011]
[Action]
Since the unmanned work method by unmanned traveling of the work vehicle according to the present invention is configured as described above, when unmanned work is performed on a work site such as a farm field by unmanned traveling of a work vehicle such as a tractor, cultivation of the farm field, etc. Can be performed reliably. That is, according to the method of the present invention, the above-described work is performed in a reciprocating rectilinear operation in which the central portion of the work site is rotated 180 degrees on the headland and the rectilinear operation is repeated, and the central portion in which the reciprocating rectilinear operation is performed. Rotate the surrounding area except for, and categorize it as a work to perform processing including headland processing. And in order to perform these reciprocating straight-ahead work and turning work,
(A) Priority order of the above-mentioned reciprocating straight work and turning work
(B) The number of return strokes from the start point to the end point of the reciprocating straight-ahead operation based on the conditions including the specifications of the work vehicle.
(C) Similarly, the number of laps from the start point to the end point of the above-mentioned turning work based on the conditions including the specifications of the work vehicle.
(D) A moving route for moving the work vehicle from a point where the work vehicle is located to a target point at the start and end of the predetermined work.
A control program including The work vehicle runs unattended according to this control program and performs unattended work.
[0012]
  As described above, in the present invention, since the control program is determined in consideration of various conditions such as the shape and area of the work site, the traveling direction that is the reference of the work vehicle, the entrance to the work site, and the like, reliable work is performed. It becomes possible. Furthermore, the respective work paths in the reciprocating straight work and the turning work are obtained by learning travel data obtained by making at least one round of the periphery of the work site by teaching travel performed prior to the work, and recording in the previous work. Set based on at least one of the received data, or make the reciprocating straight work as the first order, and the round work as the second order, the starting point of this round work is the vicinity of the corner closest to the entrance / exit of the work site By doing so, in addition to the various conditions as described above, the work start position and end position of the predetermined work can be taken into consideration, and the work can be made more reliable and more efficient. Further, the number of turn-back strokes n1 of the above-mentioned reciprocating straight-ahead operation or the number of rotations n2 of the rotation operation is set as follows.As appropriateBy setting, it becomes possible to work efficiently.
[0013]
Furthermore, in the unmanned operation method by unmanned traveling of the work vehicle according to the present invention, the traveling state of the work vehicle is set to four stages: a straight traveling stage, a 180-degree turning stage, an arbitrary angle turning stage, and a width-shifting stage. It can be configured to travel by appropriately selecting each of these stages based on the position information and the direction information obtained every moment by the position detection unit and the direction detection unit. With this configuration, the work vehicle can be unmannedly traveled with high accuracy.
[0014]
  Further, the rudder angle given to the work vehicle and the obtained change amount of the work vehicle by the rudder angle given to the work vehicle and the respective amounts of change in the position information and the azimuth information of the work vehicle accompanying giving this rudder angle. It is configured to obtain a relational expression with the turning radius and determine the steering angle for each stage based on this relational expressionSoIt is possible to prevent the work vehicle from projecting outside the work site or stepping on the area where the work has already been completed, and the work can be performed reliably and efficiently. In particular,The relational expression between the rudder angle given to the work vehicle and the obtained turning radius of the working vehicle is corrected and updated as appropriate by learning the relationship between the rudder angle and the turning radius obtained sequentially as the work progresses. It is more effective if an appropriate steering angle can be obtained.
[0015]
  In addition, as described above, when the traveling state is divided into four stages, the wheel of the work vehicle prevents the work vehicle wheel from entering the work area or the existing work area in an arbitrary angle turning stage of these four stages. Therefore, based on the information on the work site, the specifications of the work vehicle, and the relationship between the steering angle and the turning radius of the work vehicle, the backward movement without giving the rudder angle or the backward movement with the rudder angle given is performed in advance. After this, turn based on the above direction informationGo,In the width alignment stage, at least one of the width alignment by the forward movement and the width alignment by the backward movement is performed according to the width alignment amount calculated from the start point and the target end point of the stage and the movement amount in the front-rear direction.To doCan be configured. With this configuration, a small turning amount and a short width can be achieved, and it is possible to prevent the work vehicle from protruding outside the work site or stepping on an already finished area as described above.
[0016]
As a result, when performing an operation such as farming on a work site such as a farm field using the unmanned operation method by the unmanned operation of the work vehicle according to the present invention, the work vehicle can be operated with high accuracy and the unmanned operation. Work with the vehicle can be performed reliably and efficiently.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of an embodiment of the present invention will be described. FIG. 1 shows a state where a farm 1 that is a work site is cultivated by a tractor 2 that is a work vehicle by an unmanned work method by unmanned running of the work vehicle according to the present invention. In the case of this example, this cultivation is the predetermined work described in the claims. FIG. 2 shows a configuration example for carrying out the unmanned work method using the work vehicle according to the present invention. In the case of the structure of this example, a GPS (Global Positioning System) receiver 3 and a specific low-power communication device 4 are provided at an arbitrary position (for example, inside the management center) outside the farm 1 and the tractor 2. Is configured so that a differential GPS system is configured so that position information of the tractor 2 can be obtained on the tractor 2. Further, the tractor 2 is equipped with an optical fiber gyro and a geomagnetic azimuth sensor 5 so that azimuth information and vehicle inclination can be detected. Further, the tractor 2 includes a processing device 6 that collects and processes the position information, azimuth information, and the like, and a controller 7 and an actuator 8 for automatically controlling each operation unit of the tractor 2. As each of the above-described operation units, there are steering, shuttle, braking (braking), raising and lowering of the work implement, etc. as shown in FIG. The GPS receiver 3 and the specific low-power communication device 4 constitute the position detection means described in the claims, and the optical fiber gyroscope and the geomagnetic direction sensor 5 constitute the orientation detection means described in the claims. . It is also possible to adopt a configuration in which the position of the tractor 2 in the field 1 can be detected by an automatic tracking surveying device installed at an arbitrary position outside the field 1.
[0018]
In order to allow the tractor 2 as described above to run unmanned and cultivate the field 1, first, prior to this cultivation, a control program for defining the work route of the tractor 2 is created. The control program performs the operations performed by the tractor 2 such that the central portion 1b of the field 1 is rotated 180 degrees on the headland and the linear operation is repeated to repeat the linear operation, and the peripheral portion 1a of the field 1 is performed. Rotating and classifying the surrounding part 1a including the headland treatment into the rotating work, and (a) the priority order of the reciprocating rectilinear work and the turning work, and (b) the specifications of the work vehicle. The number of turn-back strokes n1 from the start point to the end point of the reciprocating straight-ahead operation based on the total length A of the tractor 2, the work width W, and the desired overlap width w, (c) Number of laps n2 from the start point to the end point of the rotating work based on the total length A, the work width W, and the work overlap width w, (d) When starting the cultivation, the tractor 2 should be cultivated from the position where it exists To the position where farm 1 starts farming The tractor 2 is moved from the point where the tractor 2 is located, such as a movement route from the position where the tractor 2 is present to the position where cultivation of the farm 1 to be cultivated next is to be started when the cultivation is completed. The movement route to move to the target point is defined.
[0019]
In addition, as shown in FIG. 3, each work path in the reciprocating straight-ahead work and the turning work is made by making one turn around the peripheral portion 1a of the farm field 1 from the start point P0 to the end point P7 by teaching traveling performed prior to the work. It sets based on the obtained learning travel data. Or it sets based on the data obtained by the recording in the operation | work in this field 1 performed before the operation | work which should be performed from now. This data is stored in various known recording media such as a flexible disk (FD). The work route may be set based on both the learning data and the data obtained by recording.
[0020]
In the case of this example, a rectangular field 1 having a long side L and a short side M as shown in FIG. In order to cultivate such a field 1, in the control program of this example, the reciprocating straight-ahead operation is set as the first order, the turning work is set as the rear order, and the starting point of this turning work is set at the entrance / exit 10 of the field 1. It is assumed that the near corner portion vicinity Q0. 4 (A) (1) to (n1) work route (reciprocating straight forward work), and (B) (10) to (17) work route (turning work) and Set. When setting each of these work paths, the number of turn-back strokes n1 of the reciprocating straight-ahead work and the number of laps n2 of the turning work are determined as follows. That is, the rotation number n2 of the rotation work, which is the configuration requirement (b) of the control program, is based on the total length A including the work device of the tractor 2, the work width W, and the desired work overlap width w.
n2 = int (A / (W−w)) + 1
Where int is a function that calculates the integer part of the quotient
Determined by In the example shown in FIG. 4B, the number of turns n2 is 2.
[0021]
Further, the number of turn-back strokes n1 of the reciprocating linear operation, which is the component requirement (c) of the control program, is obtained as follows. That is, the short side m (see FIG. 4 (A)) of the central portion 1b excluding the peripheral portion 1a that is scheduled to be processed by the turn operation that is the subsequent order from the entire field 1 is
m = M−2 (n2 · W− (n2-1) w)
And when the work overlap width to be secured at the minimum is set to w as in the case of the above-mentioned rotation work,
n1 = int ((m + w) / (W−w)) + 1
Where int is a function that calculates the integer part of the quotient
m is the width of the central portion 1b (short side)
Determined by
[0022]
Note that the number of turn-back strokes n1 of the reciprocating straight-ahead operation is set so that the work overlap width w is uniform, or the work overlap width in the final turn-back stroke is wl, and the work overlap width in the remaining turn-back strokes is Both can be set to be wd.
When the work route is set so that the work overlap width w is uniform wi as shown in FIG. 5A, the work overlap width w i is
w i = (n1 · W−m) / (n1 + 1))
It becomes.
Further, as shown in FIG. 5B, the number n1 of the folding strokes is set so that the work overlap width w in the final loopback stroke is wl and the work overlap widths w in the remaining loopback strokes are all wd. If this is the case, the work overlap width wl between the final return stroke and the return stroke immediately before this return stroke is:
wl = (W- (m- (n1-1) (W-wd))) / 2
It becomes.
[0023]
If each work route in the reciprocating straight-ahead operation and the revolving operation is set as described above, the teaching travel end position P7 (FIG. 3) or the tractor 2 at an arbitrary position on the field 1 is started. A movement path to be moved to a position PS1 (FIG. 4A) and a movement to be moved from the end position Pe (FIG. 4A) of the reciprocating rectilinear work to the start position PS2 of the revolving work (FIG. 4B). Set the route. This setting is the configuration requirement (d) of the control program.
[0024]
When the control program including each work route is determined as described above, the tractor 2 is unmanned and the farm 1 is cultivated unattended according to the control program. The tractor 2 includes a GPS receiver 3 and a specific low power communication device 4 that detect the position of the tractor 2, and an optical fiber gyroscope and a geomagnetic direction sensor 5 that detect the traveling direction of the tractor 2. For this reason, at the time of the cultivation, the tractor 2 is based on the position information and the direction information obtained every moment by the GPS receiver 3 and the specific low-power communication device 4, the optical fiber gyroscope and the geomagnetic direction sensor 5. Cultivation, which is controlled and is a predetermined work, is performed unattended along the work route defined in the control program. When starting cultivation, the GPS receiver 3 and the specific low-power communication device 4, the optical fiber gyroscope, and the geomagnetic azimuth sensor 5 give the reference position Pi and azimuth φi.
[0025]
Furthermore, in the case of the structure of this example, in order to perform the unmanned traveling of the tractor 2 with high accuracy, the traveling state of the tractor 2 is arbitrarily set to a straight traveling stage ST1, a 180-degree turning stage ST2, as shown in FIG. The stage is divided into four stages, that is, the angle turning stage ST3 and the width adjusting stage ST4, and each stage is appropriately selected and controlled based on the position information and the direction information obtained every moment by the position detection unit and the direction detection unit. To do. That is, of the travel of the tractor 2, the straight travel during the reciprocating straight work and the straight travel at the periphery 1a of the field 1 and the headland during the revolving work are defined as the straight travel stage ST1, and during the reciprocating straight work. The U-turn is a 180-degree turning stage ST2, the turning in the turning stroke at the turning operation is an arbitrary angle turning stage ST3, and the movement to the next stroke starting position is made after turning at the turning operation and the reciprocating rectilinear operation. It is referred to as a width-alignment stage ST4. Then, these four stages are selected as appropriate, and traveling according to the control program is performed. Cultivation is performed when the tractor 2 is in the straight traveling stage ST1.
[0026]
The straight traveling stage ST1 is intended for traveling along the work route of the tractor 2 and unmanned traveling for maintaining the reference traveling direction so as to move to the destination point. By controlling the rudder angle based on For example, the deviation of the position Pt and direction φt of the tractor 2 at time t from the target position and target direction on the preset work route is calculated, and the steering angle for steering the tractor 2 is obtained so as to eliminate this deviation. Control the steering angle every moment.
[0027]
The 180-degree turning stage ST2 is intended for turning when performing a straight-forward reciprocating operation. Based on the direction information, by using a single brake as appropriate at a large steering angle until the direction of the tractor 2 changes by 180 degrees, Do by turning.
[0028]
Arbitrary angle turning stage ST3 is intended for turning in turning work. Basically, based on the direction information, it turns at a large rudder angle by using a single brake as appropriate until the direction of tractor 2 changes to an arbitrary angle. Do. However, in this turning, the turning of the tractor 2 starts based on the position information and the azimuth information so that the wheels of the tractor 2 do not protrude outside the field 1 or enter the area where the work has already been completed (the existing work area). The position, target end point, position boundary of the field 1 and the existing work area are obtained, and the reverse without giving the steering angle (hereinafter referred to as reverse Mr) and the reverse with the steering angle given (hereinafter referred to as reverse Mrt) ) Is performed in advance, and then a turn at an arbitrary angle based on the azimuth information (hereinafter referred to as Mt) is performed.
[0029]
For example, as shown in FIG. 7A, at the turning start point PS3, the partition boundary of the field 1 is located forward (upward in FIG. 7A) and laterally outside the turning (right in FIG. 7A). If it is close, or if there is a work area that has been performed immediately before (the existing work area), first, the distance dfs3 from the current position (turning start position) PS3 of the tractor 2 to the front partition boundary is obtained. Next, as shown in FIG. 7B, the maximum reach position dfmax of the front wheel outside the turn when the vehicle makes a forward turn from the current position is obtained by the following equation.
dfmax = √ ((R + lf · sinα) 2+ (lf · cosα) 2)
In the above formula, R is the turning radius of turning at a large steering angle, lf is the distance from the center of the rear axle center outside the front wheels, and α is the angle formed with the vehicle center line.
[0030]
Here, if the distance ts3 shown in FIG. 7B is ts3 = dfmax−dfs3 ≦ 0, the front wheel does not protrude from the front boundary of the section even if the vehicle turns forward from the current position.
On the other hand, if the distance ts3 is ts3> 0, as shown in FIG. 7B, the distance ts3 is the amount of protrusion that the front wheel protrudes from the front partition boundary. In this case, assuming that the distance from the rear axle center to the end of the work area of the work performed immediately before is lw and the distance from the center of the rear axle center to the rear wheel outside is lr (see FIG. 7A), ts3 ≦ If it is lw, as shown in FIG. 7 (C), it is possible to prevent the front wheels from protruding from the front boundary of the partition by performing forward turning after moving backward by a distance ts3 directly behind the current position. If ts3> lw, as shown in FIG. 7D, first, it is considered that an appropriate amount of steering angle β is given to move backward Mrt, and the tractor 2 is rotated in the turning direction by an angle δ. When the direction of the tractor 2 is rotated by an angle δ, the distance ds3 from the current position to the side partition boundary and the steering angle β are given so that the rear wheel does not protrude from the side partition boundary. The limit value δ1 of the angle δ is obtained from the following equation based on the turning radius Rβ at the time.
Rβ × (1-cosδ1) = ds3−lr · cosδ1
When the steering angle β is given, the amount of protrusion of the front wheel from the partition boundary due to the reverse Mrt that rotates the tractor 2 in the turning direction by the angle δ1 is reduced by (R + Rβ) · sinδ1 in the front-rear direction. From ts3 ≦ (R + Rβ) · sinδl,
ts3 = (R + Rβ) · sinδ
An angle δ satisfying the above condition is obtained, and a reverse Mrt is performed by giving a rudder angle β from the current position until the vehicle direction changes by an angle δ. Thereafter, if a forward turn is performed, the front wheel protrudes from the front partition boundary. There is no. In the case of ts3> (R + Rβ) · sinδl, the reverse distance dMr for eliminating the protrusion of the front wheel from the front partition boundary is
dMr = ts3 − ((R + Rβ) · sinδ1)
If the vehicle travels backward by a distance dMr from the current position, then performs a backward Mrt by giving a rudder angle β until the direction of the tractor 2 changes by an angle δ1 in the turning direction, and then makes a forward turn. The front wheels do not protrude from the front boundary.
By the arbitrary turning as described above, the protrusion of the wheel from the front and side partition boundaries and the stepping by the rear wheel of the work area of the immediately preceding work behind can be almost completely prevented.
[0031]
Next, for example, as shown in FIG. 8, there is an existing work area in front of the turning start point Ps3 (above FIG. 8A) and outside turning (right side in FIG. 8A), or inside the turning. When approaching or when there is a work area that was performed immediately before, as shown in FIG. 8B, an appropriate amount of steering angle β is given from the current position (turning start point) Ps3 of the tractor 2. Then, the vehicle travels backward to the position where the rear wheel does not step on the rear working area, and the tractor 2 is rotated in the turning direction by an angle δ, and then the forward turning is performed as shown in FIG. In this case, the distance from the rear axle center to the end of the work area of the work performed immediately before is lw, the distance from the center of the rear axle center to the rear wheel outside is lr, and the turning radius when the steering angle β is given is Rβ. Then, by giving the rudder angle β and moving backward Mrt,
lw = Rβ · sinδ + lr · sinδ
The direction of the tractor 2 changes by the angle δ, and the stepping by the front wheel in the previous work area is reduced by (R + Rβ) · sinδ at the front distance, and the work area inside and outside the turn is stepped on. Without turning. Since the front wheel has already stepped on the existing work area at the current position (turning start point) Ps3, the reverse Mrt starts from a state where the steering angle is zero, and if the steering angle β is quickly given, The work area can be kept as rough as possible.
[0032]
In the width adjusting stage ST4, as shown in FIG. 9, the necessary width is determined from the relationship between the current position Ps4 of the tractor 2 that is the width adjusting start point and the start position Pes4 of the next operation that is the target end point of the width adjusting. The shift amount d and the forward movement amount ef or the backward movement amount er are calculated, and the width shift Msf by forward movement, the width shift Msr by reverse movement, or a combination of these is selected as appropriate, and based on position information and direction information Carry out width-shifting travel. For example, in the width adjustment after 180-degree turning in the reciprocating straight operation, the next work start position (width adjustment end point) Pes4 is usually ahead of the current position (width adjustment start point) Ps4 of the tractor 2, and the forward distance thereof. When the ratio d / ef between the ef and the width adjustment amount d is smaller than the reference value, as shown in FIG. 9A, the width adjustment of d is performed by the width adjustment Msf by the advance by the distance ef. When the ratio d / ef is larger than the reference value, as shown in FIG. 9B, for example, the width is first shifted by d / 3 by the width shift Msr by the backward movement of the distance ef / 2 minutes, and thereafter The remaining width of 2d / 3 is shifted by the width shift Msf by the advance of the distance 3ef / 2.
[0033]
On the other hand, in the width alignment after turning in the turning operation, the start position (width alignment end point) Pes4 of the next operation is usually behind the current position (width alignment start point) Ps4 of the tractor 2, and the rear distance er When the ratio d / er to the width adjustment amount d is smaller than the reference value, as shown in FIG. 9C, the distance d is adjusted by the distance adjustment Msr by the backward movement of the distance er. On the other hand, when the ratio d / er is larger than the reference value, as shown in FIG. 9D, for example, the width is shifted by d / 3 by the width shifting Msf by the advance of the distance er / 2, After that, the remaining width 2d / 3 is shifted by the shifting width Msr by the backward movement of the distance 3er / 2.
[0034]
Furthermore, when the steering angle in each stage mentioned above is determined, the tractor 2 is given the steering angle given to the tractor 2 and the amount of change in the position information and the direction information of the tractor 2 accompanying the provision of this steering angle. A relational expression between the given steering angle and the obtained turning radius of the tractor 2 is obtained, and the steering angle is determined based on this relational expression. That is, in order to appropriately set parameters for controlling the tractor 2 in each stage, the steering angle β given to the tractor 2 during the teaching traveling or the unmanned work based on the position information and the direction information The relationship between the rudder angle α to be given to the tractor 2 and the turning radius R of the tractor 2 obtained from the amount of change between the position information and the direction information obtained as a result of the operation or control to give the rudder angle β. Find the formula. Based on this relational expression, the steering angle β for correcting the position and orientation of the tractor 2, adjusting the width, and turning is determined. In this case, the relational expression between the rudder angle given to the tractor 2 and the obtained turning radius of the tractor 2 is appropriately determined by learning the relationship between the rudder angle and the turning radius obtained sequentially as the work progresses. Correct and update to obtain the proper steering angle.
[0035]
For example, in a 180 degree turn as shown in FIG. 10A or an arbitrary angle turn as shown in FIG. 10B, the position and traveling direction of the tractor 2 before turning are Ps (Xs, Ys), If it is φs and the position and running direction after turning with the rudder angle βi are Pe (Xe, Ye) and φe, respectively, the turning radius Ri is obtained by the formula (1) or the formula (2). It is done. In this case, Cartesian coordinates are set in the field 1 to represent the position.
Ri = √ ((Xs−Xe)²+ (Ys-Ye)²)
φ−φ = 180 Formula (1)
Ri = √ ((Xs−Xe)²+ (Ys-Ye)²) / (2sin (γ / 2))
φ−φ = α ・・・・ Formula (2)
On the other hand, if a relational expression between an arbitrary steering angle β and a turning radius, which is theoretically obtained by the distance between the front axle and the rear axle of the tractor 2 and the traveling speed, is R = F (β), During teaching driving by driving, or during unmanned work based on position information Pi and direction information φi, equation R = F (β) is sequentially corrected and updated from the relationship between actual steering angle βi and turning radius Ri, If the steering angle β given to control the vehicle using the equation is determined, the proper control of the tractor 2 can be performed at all times according to the situation of the field 1 and the stroke.
[0036]
The flow of the unmanned work method by the unmanned traveling of the work vehicle configured as described above is shown by the flowchart of FIG. However, although FIG. 11 shows the reciprocating straight-ahead operation as a priority, depending on the type of operation, the order of the reciprocating straight-ahead operation and the revolving operation surrounded by broken lines may be reversed. By using the method of this example described above, the farm 1 can be reliably cultivated by the unmanned traveling of the tractor 2. That is, according to the method of the present invention, the control program is determined in consideration of various conditions such as the shape and area of the field 1, the traveling azimuth serving as the reference for the tractor 2, and the entrance to the field 1. For this reason, reliable work is possible. Further, since the number of turn-back strokes n1 of the reciprocating straight-ahead operation or the number of rotations n2 of the rotation operation is set as described above, the operation can be performed efficiently.
[0037]
Furthermore, in the unmanned work method using the work vehicle according to the present example, the traveling state of the tractor 2 is divided into four stages: a straight traveling stage, a 180-degree turning stage, an arbitrary angle turning stage, and a width-shifting stage. Each stage is selected and executed as appropriate based on the position information and the direction information obtained every moment by the position detection unit and the direction detection unit. For this reason, unmanned traveling of the tractor 2 can be performed with high accuracy.
[0038]
Moreover, the steering angle given to the tractor 2 and the obtained tractor 2 and the tractor 2 obtained by the steering angle given to the tractor 2 and the amount of change in the position information and azimuth information of the tractor 2 when the steering angle is given. Since a relational expression with the turning radius is obtained, and the rudder angle at each stage is determined based on this relational expression, the tractor 2 protrudes outside the field 1 or steps on an already finished area. Can be prevented, and work can be performed reliably and efficiently.
[0039]
As a result, when performing work such as farming on a work site such as a farm using the unmanned work method using the work vehicle according to the present invention, the work vehicle such as the tractor 2 can be highly unmanned traveling. Work with the vehicle can be performed reliably and efficiently. In the above-described example, the case where the farm 1 is cultivated with the tractor 2 has been described. However, the present invention is not limited to this example, and when working on a work site other than the farm with another work vehicle. Is also applicable.
[0040]
【The invention's effect】
Since the unmanned work method using the work vehicle according to the present invention is configured and operates as described above, the work overlap width is appropriately set according to conditions such as the work site and the work width and specifications of the work vehicle including the work machine. The allocated efficient work route can be set. In particular, a more efficient work path can be set by setting the work start position and the end position as corners close to the entrance to the work site.
In addition, by dividing the running state of the work vehicle into four stages and combining each stage appropriately, unmanned running on the set work route can be performed with high accuracy, and a blog for route planning and vehicle control Ram can be easily developed and modified. Furthermore, in unmanned traveling on the work route, it is possible to reduce the turning radius and reduce the distance at a short distance, and as a result, it is possible to prevent the wheels of the work vehicle from protruding outside the compartment or stepping on the existing work area. The accuracy and quality of work can be improved.
In addition, the control of the work vehicle such as straight traveling, turning, and width adjustment can be appropriately performed according to the situation and the stroke of the work site. Also from this point, it is possible to improve the accuracy and quality of the work by eliminating the protrusion outside the work site and the stepping on the existing work area.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an embodiment of the present invention when a tractor in a working state is viewed from above.
FIG. 2 is a block diagram showing an apparatus provided in the tractor.
FIG. 3 is a diagram for explaining teaching running.
FIG. 4 is a diagram for explaining a reciprocating linear operation and a rotating operation.
FIG. 5 is a diagram showing an example when setting a work overlap width;
FIG. 6 is a diagram for explaining each stage when the traveling state is divided into four stages.
FIG. 7 is a view for explaining a first example of a turning state in an arbitrary angle turning stage.
FIG. 8 is also a diagram for explaining a second example.
FIG. 9 is a diagram for explaining a width alignment state in the width alignment stage.
FIG. 10 is a diagram for explaining control during turning.
FIG. 11 is a flowchart showing a flow when work is performed using the present invention.
[Explanation of symbols]
1 field
2 Tractor
3 GPS receiver
4 specified low power communication equipment
5 Optical fiber gyroscope and geomagnetic direction sensor
6 processing equipment
7 Controller
8 Actuator
10 Doorway

Claims

An unmanned operation method by unmanned traveling of a work vehicle, which performs the predetermined work in the work site by unmanned running a work vehicle that performs a predetermined work in a work site of a predetermined section,
The above-mentioned work is performed in the center part of the work site by reciprocating rectilinear work that repeats the rectilinear work by turning 180 degrees on the headland and the peripheral part excluding the central part in which the reciprocating straight work is performed. A control program having the following requirements (a) to (d), which is divided into revolving work for performing processing including ground processing, and each reciprocating straight work and revolving work are defined for each work route. Create
(A) Priority order between the reciprocating linear operation and the revolving operation (b) The number of turn-back strokes from the start point to the end point of the reciprocating linear operation based on the conditions including the specifications of the work vehicle (c) The number of laps from the start point to the end point of the above-mentioned turning work based on the conditions including the specifications of the vehicle. (D) When starting and ending the predetermined work, the work vehicle is moved from the point where the work vehicle is located. The movement route to move to the point
The work vehicle includes position detection means for detecting the position of the work vehicle, and direction detection means for detecting the traveling direction of the work vehicle, and is obtained from time to time by the position detection means and the direction detection means. In performing a predetermined work by performing unmanned traveling along the work route defined in the control program based on the position information and the direction information ,
The rudder angle given to the work vehicle and the turning angle of the work vehicle obtained from the rudder angle given to the work vehicle and the respective amounts of change in the position information and the azimuth information of the work vehicle accompanying giving the rudder angle An unmanned driving method based on unmanned traveling of a work vehicle that obtains a relational expression with a radius and controls the steering angle of the work vehicle during the reciprocating straight-ahead work or the turning work based on the relational expression .

The relational expression between the rudder angle given to the work vehicle and the turning radius of the work vehicle obtained is corrected and updated by learning the relation between the rudder angle and the turning radius obtained every time the work progresses. The unmanned working method by unmanned traveling of the work vehicle according to claim 1 , wherein an appropriate relationship between the steering angle and the turning radius can be obtained .

The traveling state of the work vehicle is divided into four stages: a straight traveling stage, a 180-degree turning stage, an arbitrary angle turning stage, and a width-shifting stage, and is obtained every moment by the position detecting means and the direction detecting means. When selecting each of these stages appropriately based on the position information and direction information
In the above arbitrary angle turning stage, in order to prevent the wheel of the work vehicle from entering the outside of the work site or the existing work area, information on the work site, the specifications of the work vehicle, the steering angle and the turning radius of the work vehicle. From the relationship, the arrival position of the front wheels when the vehicle turns forward from the start point of this stage and the distance to the surrounding existing work area are calculated, and based on those positions and distances, the work vehicle is The vehicle according to claim 1 or 2, wherein the vehicle is reversely driven in a state in which the rudder angle is not given or the reverse in a state in which the rudder angle is given in advance, and thereafter, the vehicle is turned based on the azimuth information. Unmanned work method.

In the above-mentioned width adjustment stage, when the target end point of width adjustment is ahead of the start point of this stage, the front width adjustment ratio obtained by dividing the required width adjustment amount by the forward movement amount is calculated, and the ratio is a constant In the above case, after performing a part of the necessary width adjustment by the advance width adjustment in advance, the advance width adjustment is performed to complete the required width adjustment, and when the ratio is below a certain constant, only the advance width adjustment is performed. When the required width adjustment is completed, and the target end point of the width adjustment is behind the start point of this stage, the rear width adjustment ratio is calculated by dividing the required width adjustment amount by the backward movement amount. If the ratio is greater than or equal to a certain constant, perform some of the required width alignment by advance width adjustment in advance and then perform the reverse width adjustment to complete the required width adjustment. The required width adjustment is completed only by width adjustment. Unmanned working methods by unmanned running of the work vehicle described.