JP4052624B2

JP4052624B2 - Transport system and control method of transport system

Info

Publication number: JP4052624B2
Application number: JP2001100146A
Authority: JP
Inventors: 雄一黒田
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2001-03-30
Filing date: 2001-03-30
Publication date: 2008-02-27
Anticipated expiration: 2021-03-30
Also published as: JP2002299412A

Description

【０００１】
【発明の属する技術分野】
本発明は、生産ライン等で使用される搬送システムに関するもので、特に生産ラインの状況に応じた搬送体の投入および撤去に関するものである。
【０００２】
【従来の技術】
以下、従来の技術を、半導体ウエハの搬送システムを一例として説明する。
【０００３】
図６に示すように、従来の半導体ウエハの搬送システム３００では、複数の搬送作業ポイント３０１を結ぶメイン搬送路３０２と、このメイン搬送路３０２に接続する搬送路として、待機用送路３０３から走行路が構成され、搬送されたウエハを処理する各処理装置３０４は、メイン搬送路３０２の周囲に沿って、複数の搬送作業ポイント３０１と対応する位置に設置されている。この搬送システム３００では、半導体ウエハ（以下ウエハと称する）は収納容器（＝ポッド）等に収納された搬送物３０５として、メイン搬送路３０２において搬送される。搬送物３０５は、搬送車制御装置３０６によって制御される搬送車３０７に積載され、メイン搬送路３０２において搬送される。また、待機用搬送路３０３には、予備搬送車３０８が準備され、搬送車制御装置３０６の搬送指令を受けて、適宜、搬送車３０７の数を補うべくメイン搬送路３０２に投入される。
【０００４】
従来の搬送システム３００では、図６に示すように、設計段階での搬送量に対して、数倍程度の余裕を見積もり、メイン搬送路３０２に搬送車（＝搬送車３０７、予備搬送車３０８）を投入している。このために、メイン搬送路３０２には、ウエハの搬送作業、または回送作業等に必要か否かに関わらず投入され、実際の搬送物（＝ウエハを収納した収納容器）の搬送量に対して、必要以上に、搬送車（＝搬送車３０７、予備搬送車３０８）が多数存在することになる。
【０００５】
このような搬送システムでは、図７に示すように、搬送車制御装置３０６から発せられた搬送指令は、実際にウエハを搬送するか否かに関わらず、搬送車３０７及び予備搬送車３０８に割り付けられている。このため、待機用送路３０３を設けていても、一時的に搬送指令が多量に発生した場合には、投入される搬送車（＝搬送車３０７、予備搬送車３０８）の数は増加するばかりで、メイン搬送路３０２では搬送車（＝搬送車３０７、予備搬送車３０８）同士の干渉がさらに増加する。また、一度メイン搬送路３０２へ投入された搬送車（＝搬送車３０７、予備搬送車３０８）は、充電または保守等の作業が行われない限り、メイン搬送路３０２から撤去されることもない。
【０００６】
このような状況で、搬送車制御装置３０６から搬送指令が発せられた場合、搬送を行う搬送車３０７は、搬送を行わない予備搬送車３０８に、搬送作業及び回送作業の動作を妨げられることになる。従って、搬送物（＝ウエハを収納した収納容器）の搬送工期、引いては半導体装置の生産工期の遅れに繋がるという問題が発生する。また、必要のない予備搬送車３０８をメイン搬送路３０２で稼働させることにより、搬送システム３００を稼働させるための動力（＝電力）も多量に必要となり、また、不必要なときに予備搬送車３０８を動作させることで、予備搬送車３０８として稼働する搬送車の車輪やモータ等は余計に費やされ、最終的に各搬送車の使用寿命が短くなり、経済的コスト上の問題が発生する。
【０００７】
【発明が解決しようとする課題】
以上のように、従来の搬送システムでは、搬送物（例：ウエハを収納した収納容器）の搬送量と、この搬送物を搬送する上で必要となる搬送車の数を管理することなしに、搬送システムを稼働させている。従って、その分、搬送車同士の干渉頻度が増加するため、各搬送車が搬送作業または回送作業に余計な時間を費やし、搬送車全体での搬送物の搬送工期の増加、引いては、半導体装置等の生産工期の遅れに繋がるという問題がある。
【０００８】
従って、本発明の目的は、搬送システムにおいて、搬送物の搬送量と、この搬送物を搬送する上で必要となる搬送車の数を管理し、従来よりも、搬送車全体での搬送工期を短縮化して、効率化されるように制御することにある。
【０００９】
【課題を解決するための手段】
本発明は、生産ライン等で使用される搬送システムに関し、搬送物の搬送状況に応じて搬送体の投入および撤去を行う、搬送システム及び搬送システムの制御方法を提供するものである。
【００１１】
また、本発明は、搬送路と、この搬送路を移動して搬送物を搬送する搬送体と、
この搬送体を制御する搬送体制御部と、所定期間毎に、前記搬送体と前記搬送物に関係するデータを記憶するシステム状況記憶部と、前記データを参照して、任意の時点での前記搬送物の搬送に要する前記搬送体の最適数を決定し、この最適数と前記任意の時点で前記搬送路に在る搬送体の数との差を算出する最適搬送体数決定部と、前記最適搬送体数決定部の前記算出結果を参照し、前記搬送路への前記搬送体の投入、または前記搬送路からの前記搬送体の撤去を前記搬送体制御部に指示する搬送体投入・撤去決定部と、前記システム状況記憶部に記憶されたデータから、任意の時点で前記搬送路に在る搬送体の数と同一で、かつ前記任意の時点で搬送待ちの状態にある搬送物の数に最も近い値を示すデータを選択し、このデータに示される実績搬送回数を予想搬送量として算出する予想搬送量算出部と、前記搬送物の搬送回数に対して、必要な搬送体の数を記憶する必要台数データ記憶部とを備え、前記最適搬送体数決定部は、前記必要台数データ記憶部から、前記予想搬送量算出部より算出された前記予想搬送量と一致する数の搬送回数を選択して、この搬送回数に対応する搬送体の数を搬送体の最適数とし、且つこの最適数と前記任意の時点での前記搬送体の数との差を算出し、前記搬送体投入・撤去決定部は、前記算出結果を参照して、前記搬送路への搬送体の投入または前記搬送路からの前記搬送体の撤去を前記搬送体制御部へ指示することを特徴とする搬送システムを提供することができる。
【００１２】
また、本発明は、搬送路と、この搬送路を移動して搬送物を搬送する搬送体と、
この搬送体を制御する搬送体制御部と、所定期間毎に、前記搬送体と前記搬送物に関係するデータを記憶するシステム状況記憶部と、任意の時点において、前記搬送物の搬送に要する前記搬送体の最適数を決定し、この最適数と、前記任意の時点に前記搬送路に在る前記搬送体の数の差を算出する最適搬送体数決定部と、前記最適搬送体数決定部の算出結果を参照し、前記搬送路への前記搬送体の投入、または前記搬送路からの前記搬送体の撤去を前記搬送体制御部に指示する搬送体投入・撤去決定部とを備え、前記最適搬送体数決定部は、前記システム状況記憶部に記憶されるデータから、前記任意の時点で搬送待ちの状態に在る前記搬送物の数に最も近い待ち搬送物数を示し、且つ前記搬送物の平均搬送工期が最も短いデータを選択し、このデータの搬送体の数を、前記任意の時点で前記搬送物の搬送に要する前記搬送体の最適数として決定することを特徴とする搬送システムを提供することができる。
【００１４】
また、本発明は、搬送路と、この搬送路を移動して搬送物を搬送する搬送体と、この搬送体を制御する搬送体制御部とを有する搬送システムにおいて、所定期間毎に、前記搬送体と前記搬送物に関係するデータを、前記搬送システムの実績データとして記憶する過程と、前記実績データから、任意の時点に前記搬送路に在る前記搬送体の数と同一で、且つ、前記搬送路で、前記任意の時点に搬送待ちの状態に在る搬送物の数と最も近い値を有するデータを選択する過程と、この選択されたデータの有する実績搬送回数を、前記任意の時点での前記搬送物の予想搬送量として算出する過程と、前記予想搬送量に要する搬送体の数を、前記任意の時点で、前記搬送物の搬送に要する前記搬送体の最適数として決定し、前記搬送体の最適数と前記任意の時点で前記搬送路に在る搬送体の数との差を算出する過程と、前記搬送体の最適数と、前記任意の時点で前記搬送路に在る搬送体の数との差を参照し、前記搬送路へ搬送体を投入するか、または前記搬送路から前記搬送体を撤去するかを前記搬送体制御部に指示する過程とを有することを特徴とする搬送システムの制御方法を提供することができる。
【００１５】
また、本発明は、搬送路と、この搬送路を移動して搬送物を搬送する搬送体と、この搬送体を制御する搬送体制御部とを有する搬送システムにおいて、所定期間毎に、前記搬送体と前記搬送物に関係するデータを、前記搬送システムの実績データとして記憶する過程と、前記実績データから、前記搬送路で、任意の時点に搬送待ちの状態に在る前記搬送物の数と最も近い値を有し、且つ前記搬送物の平均搬送工期が最も短いデータを選択し、このデータの有する搬送体の数を、前記任意の時点で、前記搬送物の搬送に要する前記搬送体の最適数として決定する過程と、前記搬送体の最適数と前記任意の時点で前記搬送路に在る前記搬送体の数との差を算出する過程と、前記搬送体の最適数と、前記任意の時点で前記搬送路に在る前記搬送体の数との差を参照し、前記搬送路へ前記搬送体を投入するか、または前記搬送路から前記搬送体を撤去するかを前記搬送体制御部に指示する過程を有することを特徴とする搬送システムの制御方法を提供することができる。
【００１６】
本発明は、搬送システム内の搬送状況に応じて、搬送体の搬送路への投入または搬送路からの撤去を行い、搬送車等、搬送路に在る搬送体の数を調整する。従って、必要数分の搬送体だけを用いて搬送物の搬送を行うことができ、搬送体同士の干渉頻度を低減させ、搬送工期を短縮化することができる。
【００１７】
【発明の実施の形態】
以下、図面を参照しながら本発明の実施の形態について説明する。
（第１の実施の形態）
半導体装置を製造する過程では、半導体ウエハ等の基板を処理する各処理装置間で、搬送車等の搬送体を用いてウエハの搬送を頻繁に行う。本実施の形態では、このような半導体ウエハの搬送を一例として、搬送システム及び搬送システムの制御方法について図１乃至図４を用いて説明する。
【００１８】
図１に示すように、半導体ウエハの搬送システム１００は、複数の搬送作業ポイント１０１を連結するメイン搬送路１０２と、このメイン搬送路１０２に接続された待機用搬送路１０３とから構成される走行路を有する。
【００１９】
処理装置１０４は、または搬送物保管装置が、搬送作業ポイント１０１に対向し、尚且つメイン搬送路１０２の外周に沿った所定の位置に配置されている。また、ウエハは、各処理装置１０４（または搬送物保管装置）に投入すべく、搬送物１０５の内部に保持された状態でメイン搬送路１０２を搬送される。搬送物１０５には、ウエハをロット毎（１ロットはウエハ２４枚程度）内部に保持し、収納できる、所謂、ウエハ搬送用のポッド等を使用することができる。
【００２０】
尚、本実施の形態では、図１に示すように、メイン搬送路１０２にループ形状の搬送路を使用するが、格子状の搬送路等も使用することが可能であり、形状は特に限定されないものとする。
【００２１】
図１に示すように、メイン搬送路１０２では、搬送車制御装置１０６から発せられた指令内容に基づいて搬送車１０７が走行し、また、待機用走路１０３では、予備搬送車１０８が準備される。
【００２２】
搬送車１０７は、搬送車制御装置１０６からの搬送指令に基づいて、搬送物１０５の搬送に関係する作業を行う。例えば、搬送車１０７は、ウエハを内部に保持した搬送物１０５を積載し、各処理装置１０４（または搬送物保管装置）へ搬送する作業（＝搬送作業）を行う。また、搬送車１０７は、処理装置１０４（または搬送物保管装置）において搬送物１０５を受け取るべく、搬送物１０５を積載せずにメイン搬送路１０２を走行する作業（＝回送作業）を行う場合もある。一方、予備搬送車１０８は、搬送車１０７の数に不足が生じた場合、搬送車制御装置１０６の搬送指令に基づいて、適宜、待機用搬送路１０３からメイン搬送路１０２に投入される。
【００２３】
本実施の形態では、図１に示すように、搬送車制御装置１０６には、システム状況記憶装置１０９、最適搬送車数決定部１１０、及び搬送車投入・撤去決定部１１１が設けられている。また、搬送車制御装置１０６には、予想搬送量算出装置１１２、必要台数データ記憶装置１１３、及び待ち搬送物数変動記憶装置１１４が接続されている。
【００２４】
尚、最適搬送車数決定部１１０は、最適搬送車数を決定するプログラム、また、搬送車投入・撤去決定部１１１は、メイン搬送路１０２への予備搬送車１０８の投入、またはメイン搬送路１０２からの予備搬送車１０８の撤去を決定するプログラムを有するものとする。
【００２５】
図２（ａ）に示すように、システム状況記憶装置１０９は、搬送システム１００の搬送状況を示す各種情報（データ）をシステム状況データとして記憶させる。このシステム状況データは、所定期間毎に、搬送システム１００に存在する搬送車（搬送車１０７、予備搬送車１０８）の（台）数、搬送システム１００で実際に搬送された搬送物１０５の実績搬送数、搬送システム１００で搬送待ちの状態にある搬送物１０５の数、及び平均搬送工期（単位：sec）等を主要な情報（データ）として、ホストコンピュータ（特に図示せず）から抽出し、システム状況記憶装置１０９に随時記憶させ、過去の実績データとして蓄積している。また、このシステム状況データは、例えば、１時間単位、または１日単位というように、任意の期間単位を選択して随時記憶させることができる。本実施の形態では、図２（ａ）に示すように、１日単位でデータを記憶させている。
【００２６】
また、図２（ｂ）に示すように、必要台数データ記憶装置１１３は、シミュレーションの結果やユーザの希望する搬送車（台）数に基づいて作成した、「搬送回数−必要搬送車（台）数」の関係を表すデータを記憶する。搬送車１０７の必要（台）数のデータは、あらかじめユーザが設定していても良いし、シミュレーションを行って得られた結果に随時更新し、記憶させるようにしても良い。
【００２７】
以下に、図３を参照し、ウエハを内部に保持し、積載する搬送物の予想搬送量に基づいて、最適搬送車数決定部１１０が、最適搬送車（台）数を決定する手順を説明する。
【００２８】
まず、最適搬送車数決定部１１０は、現状、即ち、現在（＝任意に選択される時点）の搬送システム１００の状況を表す情報として、搬送待ちの状態にある搬送物１０５の数と、搬送車（搬送車１０７、予備搬送車１０８）の（台）数をホストコンピュータに問い合わせる（＝ステップ１）。
【００２９】
次に、予想搬送量算出装置１１２は、これら現在の状況を表すデータと比較し、システム状況記憶装置１０９に記憶された過去のシステム状況データの中から同一の搬送車（台）数で、尚且つ最も近い数の待ち搬送物数を示すシステム状況データを検索する（＝ステップ２）。
【００３０】
次に、予想搬送量算出装置１１２は、検索されたシステム状況データに示される実績搬送回数を現在の搬送物１０５の予想搬送量として算出する（＝ステップ３）。この場合、同一の搬送車（台）数で、尚且つ待ち搬送物数においても合致するデータが１つである場合は、予想搬送量として１つの算出結果を選択するが、待ち搬送物数に合致するデータが複数ある場合は、例えば、１００〜１２０（回／ｈｒ（＝単位時間毎の搬送回数））というように算出結果に範囲をもたせて、これを予想搬送量とする。
【００３１】
次に、最適搬送車数決定部１０９は、この予想搬送量に対し、必要台数データ記憶装置１１３の必要台数データと比較して最適搬送車（台）数を決定する（＝ステップ４）。必要台数データ記憶装置１１３は、図２（ｂ）に示すように、シミュレーションの結果やユーザの希望する搬送車（台）数に基づいて作成した、「搬送回数−必要搬送車（台）数」の関係を表すデータを記憶している。従って、このデータから、予想搬送量の値と合致する搬送回数を検索し、対応する必要搬送車（台）数を最適搬送車（台）数として決定する。
【００３２】
次に、最適搬送車数決定部１０９は、最適搬送車（台）数とメイン搬送路１０２にある現在の搬送車（搬送車１０７、予備搬送車１０８）の（台）数との差を算出する（＝ステップ５）。
【００３３】
次に、待ち搬送数物変動記憶装置１１４は、搬送システム１００に在り、搬送待ちの状態にある搬送物数の変動傾向を待ち搬送物数の変動データとして記憶し、待ち搬送物数の変動が増加傾向にあるのか、減少傾向にあるのか、或いは、横這い（＝略一定）傾向にあるのかを、搬送車投入・撤去決定部１１１に伝達する。（＝ステップ６）
次に、搬送車投入・撤去決定部１１１は、メイン搬送路１０２への予備搬送車１０８の投入または撤去の要否を決定する（＝ステップ７）。
【００３４】
先ず、搬送車投入・撤去決定部１１１が、メイン搬送路１０２への予備搬送車１０８の投入を決定するまでの手順（＝ステップ７−１）を説明する。
【００３５】
例えば、「最適搬送車（台）数＝現在の搬送車（搬送車１０７、予備搬送車１０８、以降省略）の（台）数」である場合は、現在の搬送車数で搬送が可能であり、「メイン搬送路１０２への予備搬送車１０８の投入を行わない」と決定する。また「最適搬送車（台）数＞現在の搬送車（台）数」である場合は、待ち搬送物数の変動傾向を考慮する。即ち、予備の搬送車１０８の投入が必要な場合でも、待ち搬送物数が減少傾向にある場合は、「メイン搬送路１０２への予備搬送車１０８の投入を行わない」と決定し、待ち搬送物数の変動が増加傾向、或いは横這い（＝略一定）の状態にある場合は、「メイン搬送路１０２へ予備搬送車１０８を投入する」と決定する。
【００３６】
このように、待ち搬送物数の変動傾向を考慮すると、搬送システム１００の状況とリンクして、精度良く、予備搬送車１０８の投入が可能となり、更に、搬送車同士の干渉頻度を低減させ、搬送工期の短縮化が可能となる。
【００３７】
尚、待ち搬送物数変動記憶装置１１４が備えられていない場合、搬送車投入・撤去決定部１１０は、待ち搬送物数の変動傾向は考慮せず、現在の搬送車（台）数で搬送が不可能な場合に、必要（台）数分の予備搬送車１０８の投入を決定する。
【００３８】
次に、搬送車投入・撤去決定部１１１がメイン搬送路１０２からの予備搬送車１０８の撤去を決定するまでの手順（ステップ７−２）を説明する。
【００３９】
「最適搬送車（台）数＝現在の搬送車（搬送車１０７、予備搬送車１０８、以降省略）の（台）数」である場合は、現在の搬送車の（台）数が必要であり、「メイン搬送路１０２への予備搬送車１０８の投入または撤去を行わない」と決定する。また、「最適搬送車（台）数＜現在の搬送車（台）数」である場合は、待ち搬送物数の変動傾向を考慮する。即ち、待ち搬送物数が増加傾向にある場合は、「メイン搬送路１０２からの予備搬送車１０８の撤去を行わない」と決定し、待ち搬送物数の変動が減少傾向、或いは横這い（＝略一定）の状態にある場合は、「メイン搬送路１０２から予備搬送車１０８を撤去する」と決定する。
【００４０】
このように、待ち搬送物数の変動傾向を考慮すると、搬送システム１００の搬送状況とリンクして、精度良く、予備搬送車１０８の撤去が可能となり、更に、搬送車同士の干渉頻度を低減させ、搬送工期の短縮化が可能となる。
【００４１】
尚、待ち搬送物数変動記憶装置１１３が備えられていない場合、搬送車投入・撤去決定部１１１は、待ち搬送物数の変動傾向を考慮せず、現状よりも少ない搬送車の（台）数で搬送が可能な場合に、不要（台）数分の予備搬送車１０８の撤去を決定する。
【００４２】
次に、搬送車投入・撤去決定部１１１の決定結果に基づき、搬送車制御装置１０６は、予備搬送車１０８に投入または撤去に関する搬送指令を割り付け、予備搬送車１０８は「メイン搬送路１０２への移動」または「待機用走路１０３への移動」を開始する（＝ステップ８）。
【００４３】
従来の搬送システムでは、設計段階での搬送量に対して数倍程度の余裕を見積もり、予備搬送車を含め、メイン搬送路に搬送車を投入している。また、搬送車に搬送指令を割り付る場合、搬送指令の発生と同時に、不要な予備搬送車にも無条件に搬送指令が割り付けられる。従って、メイン搬送路では搬送車の数が増加し、搬送及び回送の作業を行う搬送車は、不要で、搬送指令を持たない予備搬送車によって進路を妨げられ、搬送工期は増加し、引いては、生産工期が遅れることになる。
【００４４】
本実施の形態では、過去のシステム状況を表すデータのうち、現在（＝任意に選択された時点）の待ち搬送物数に最も近い値を示すデータの実績搬送数を予想搬送量と決定し、これを必要搬送車（台）数データと比較して、メイン搬送路１０２への予備搬送車１０８の投入、またはメイン搬送路１０２からの予備搬送車１０８の撤去を決定する。これにより、メイン搬送路１０２に在る搬送車の数を調整し、搬送車同士の干渉頻度を低減させ、搬送工期を短縮化することが可能となる。また、不要な予備搬送車１０８を稼働させないことにより、従来よりも、搬送システムの稼働に要する消費電力を抑制し、搬送車の使用寿命を伸ばすことが可能となる。
【００４５】
また、本実施の形態では、前述の如く、待ち搬送物数の変動傾向を考慮して、メイン搬送路１０２への予備搬送車１０８の投入、またはメイン搬送路１０２からの予備搬送車１０８の撤去を決定する。これにより、搬送システム１００内の搬送状況とリンクして、メイン搬送路１０２に在る搬送車（搬送車１０７、予備搬送車１０８）の数を調整することが可能となり、更なる搬送車同士の干渉頻度の低減、引いては、搬送工期の短縮化が可能となる。
（第２の実施の形態）
本実施の形態では、（第１の実施の形態）と同様に、半導体ウエハの搬送を一例とし、搬送システム及び搬送システムの制御方法について、図４及び図５を用いて説明する。
【００４６】
図４に示すように、半導体ウエハの搬送システム２００は、複数の搬送作業ポイント２０１を結ぶメイン搬送路２０２と、このメイン搬送路２０２に接続された待機用搬送路２０３とから構成される走行路を有する。
【００４７】
処理装置２０４（または搬送物保管装置）は、搬送作業ポイント２０１に対向し、尚且つメイン搬送路２０２の外周に沿った所定の位置に配置されている。また、ウエハは、処理装置２０４（または搬送物保管装置）に投入すべく、搬送物２０５の内部に保持された状態でメイン搬送路２０２を搬送される。搬送物２０５には、ウエハをロット毎（１ロットはウエハ２４枚程度）収納できる、所謂、ウエハ搬送用のポッド等を使用することができる。
【００４８】
尚、本実施の形態では、図４に示すように、メイン搬送路２０２にループ形状の搬送路を使用するが、格子状の搬送路等も使用することが可能であり、形状は特に限定されないものとする。
【００４９】
図４に示すように、メイン搬送路２０２では、搬送車制御装置２０６から発せられた指令内容に基づいて搬送車２０７が走行し、また、待機用送路２０３では、予備搬送車２０８が準備される。
【００５０】
搬送車２０７は、搬送車制御装置２０６からの搬送指令に基づいて、搬送物２０５の搬送に関係する作業を行う。例えば、搬送車２０７は、ウエハを内部に保持した搬送物２０５を積載し、処理装置２０４（または搬送物保管装置）へ搬送する作業（＝搬送作業）を行う。また、搬送車２０７は、処理装置２０４において搬送物２０５を受け取るべく、搬送物２０５を積載せずにメイン搬送路２０２を走行する作業（＝回送作業）を行う場合もある。一方、予備搬送車２０８は、搬送車２０７の（台）数に不足が生じた場合、搬送車制御装置２０６の搬送指令に基づいて、適宜、待機用搬送路２０３からメイン搬送路２０２に投入される。
【００５１】
図４に示すように、搬送車制御装置２０６には、システム状況記憶装置２０９、最適搬送車数決定部２１０、及び搬送車投入・撤去決定部２１１とが設けられている。また、搬送車制御装置２０６には、待ち搬送物数変動記憶装置２１２が接続されている。
【００５２】
システム状況記憶装置２０９、搬送車投入・撤去決定部２１１、及び待ち搬送物数変動記憶装置２１２は、（第１の実施の形態）のシステム状況記憶装置１０９、最適搬送車数決定部１１０、及び搬送車投入・撤去決定部１１１の各々と同じ構造を有し、且つ搬送システム２００に同様に作用するものである。
【００５３】
システム状況記憶装置２０９は、図２（ａ）に示すように、搬送システム２００の搬送稼働状況を示す各種情報（データ）をシステム状況データとして記憶させる。このシステム状況データは、所定期間毎に、搬送システム２００に存在する搬送車（搬送車２０７、予備搬送車２０８）の（台）数、搬送システム２００で実際に搬送された搬送物２０５の実績搬送数、搬送システム２００で搬送待ちの状態にある待ち搬送物２０５の数、及び平均搬送工期（単位：sec）等を主要な情報（データ）として、ホストコンピュータ（特に図示せず）から抽出し、システム状況記憶装置２０９に随時記憶させ、実績データとして蓄積している。このシステム状況データは、例えば、１時間単位、または１日単位というように、任意の期間単位を選択して随時記憶させることができる。本実施の形態では、図２（ａ）に示すように、１日単位でデータを記憶させている。
【００５４】
以下に、図５を参照し、ウエハ等を内部に保持し、収納する搬送物の平均搬送工期を参照して、最適搬送車数決定部２１０が最適搬送車（台）数を決定する手順を説明する。
【００５５】
尚、平均搬送工期は、所定期間（例：１時間、１日、または１ヶ月）内に搬送が完了した搬送物を対象として、搬送に要した時間（＝搬送工期）を合計し、これを平均化したものである。この場合、搬送に要した時間には、搬送車に搬送指令を割り付けて投入する時間、搬送車が搬送物を搬送する作業に要した時間、搬送体が（搬送物を積載せずに）回送作業をする時間等が含まれることになる。
【００５６】
先ず、最適搬送車数決定部２１０は、現状、即ち、現在（＝任意に選択された時点）の搬送システム２００の状況を表す情報として、搬送待ちの状態にある搬送物２０５の数をホストコンピュータに問い合わせる（＝ステップ１）。
【００５７】
次に、最適搬送車数決定部２１０は、この現在（＝任意に選択された時点）の状況を表すデータと比較し、システム状況記憶装置２０９に記憶された過去のシステム状況データの中から、現在の待ち搬送物数に最も近く、尚且つ平均搬送工期が最短の値を示すシステム状況データを検索する（＝ステップ２）。
【００５８】
次に、最適搬送車数決定部２１０は、検索されたデータに示される搬送車（台）数を最適（台）数として決定する（＝ステップ３）。
【００５９】
次に、メイン搬送路２０２にある現在の搬送車（搬送車２０７、予備搬送車２０８）の（台）数との差を算出する（＝ステップ４）。
【００６０】
次に、待ち搬送数物変動記憶装置２１２は、搬送システム２００で搬送待ちの状態にある、待ち搬送物数の変動傾向を、待ち搬送物数変動データとして記憶し、待ち搬送物数の変動が増加傾向にあるのか、減少傾向にあるのか、或いは、横這い（＝略一定）の状態にあるのかを、搬送車投入・撤去決定部２１１に伝達する。（＝ステップ５）
次に、搬送車投入・撤去決定部２１１は、メイン搬送路２０２への予備搬送車２０８の投入または撤去の要否を決定する（＝ステップ６）。
【００６１】
ここでは、（第１の実施の形態）と同様に、搬送システム２００で搬送待ちの状態にある、待ち搬送物数の変動傾向を考慮し、予備搬送車２０８の投入及び撤去の要否を決定する。即ち、搬送車投入・撤去決定部２１１は、待ち搬送物数の変動傾向を考慮して、最適搬送車数が、現在メイン搬送路２０２に在る搬送車（搬送車２０７、予備搬送車２０８）の（台）数よりも多い場合に、メイン搬送路２０２への予備搬送車２０８の投入を決定し、また、最適搬送車数が、現在メイン搬送路２０２に在る搬送車（搬送車２０７、予備搬送車２０８）の（台）数よりも少ない場合に、メイン搬送路２０２からの予備搬送車２０８の撤去を決定する。
【００６２】
以下に、予備搬送車２０８の投入及び撤去を決定する手順を図５に示す。
【００６３】
先ず、搬送車投入・撤去決定部２１１が、メイン搬送路２０２への予備搬送車２０８の投入を決定するまでの手順（＝ステップ６−１）を説明する。
【００６４】
例えば、「最適搬送車（台）数＝現在の搬送車（搬送車２０７、予備搬送車２０８、以降省略）の（台）数」である場合は、現在の搬送車数で搬送が可能であり、「メイン搬送路２０２への予備搬送車２０８の投入を行わない」と決定する。また「最適搬送車（台）数＞現在の搬送車（台）数」である場合は、待ち搬送物数の変動傾向を考慮する。即ち、予備搬送車２０８の投入が必要な場合でも、待ち搬送物数が減少傾向にある場合は、「メイン搬送路２０２への予備搬送車２０８の投入を行わない」と決定し、待ち搬送物数の変動が増加傾向、或いは横這い（＝略一定）状態にある場合は、「メイン搬送路２０２へ予備搬送車２０８を投入する」と決定する。
【００６５】
このように、待ち搬送物数の変動傾向を考慮すると、精度良く、搬送システム２００の状況とリンクした予備搬送車２０８の投入が可能となり、更に、搬送車同士の干渉頻度を低減させ、搬送工期の短縮化が可能となる。
【００６６】
尚、待ち搬送物数変動記憶装置２１２が備えられていない場合、搬送車投入・撤去決定部２１０は、待ち搬送物数の変動傾向は考慮せず、現在の搬送車（台）数で搬送が不可能な場合に、必要（台）数分の予備搬送車２０８の投入を決定する。
【００６７】
次に、搬送車投入・撤去決定部２１１がメイン搬送路２０２から予備搬送車２０８の撤去を決定するまでの手順（ステップ６−２）を説明する。
【００６８】
例えば、「最適搬送車（台）数＝現在の搬送車（搬送車２０７、予備搬送車２０８、以降省略）の（台）数」である場合は、現在の搬送車の（台）数が必要であり、「メイン搬送路２０２からの予備搬送車２０８の撤去を行わない」と決定する。また、「最適搬送車（台）数＜現在の搬送車（台）数」である場合は、待ち搬送物数の変動傾向を考慮する。即ち、待ち搬送物数が増加傾向にある場合は、「メイン搬送路２０２からの予備搬送車２０８の撤去を行わない」と決定し、待ち搬送物数の変動が減少傾向、或いは横這いの状態（＝略一定の状態）にある場合は、「メイン搬送路２０２からの予備搬送車２０８を撤去する」と決定する。
【００６９】
このように、待ち搬送物数の変動傾向を考慮すると、精度良く、搬送システム２００の状況とリンクした予備搬送車２０８の撤去が可能となり、更に、搬送車同士の干渉頻度を低減させ、搬送工期の短縮化が可能となる。
【００７０】
尚、待ち搬送物数変動記憶装置２１２が備えられていない場合、搬送車投入・撤去決定部２１１は、待ち搬送物数の変動傾向を考慮せず、現在よりも少ない搬送車の（台）数で搬送が可能な場合に、不要（台）数分の予備搬送車２０８の撤去を決定する。
【００７１】
次に、搬送車投入・撤去決定部２１１の決定結果に基づき、搬送車制御装置２０６は、投入または撤去される予備搬送車２０８に搬送指令を割り付け、予備搬送車２０８は「メイン搬送路２０２への移動」または「待機用送路２０３への移動」を開始する（＝ステップ７）。
【００７２】
従来の搬送システムでは、設計段階での搬送量に対して数倍程度の余裕を見積もり、予備搬送車を含め、メイン搬送路に搬送車を投入している。また、搬送車に搬送指令を割り付る場合、搬送指令の発生と同時に、不要な予備搬送車にも無条件に搬送指令が割り付けられる。従って、メイン搬送路では搬送車の数が増加し、搬送及び回送の作業を行う搬送車は、不要で、搬送指令を持たない予備搬送車によって進路を妨げられ、搬送工期が増加し、引いては、生産工期が遅れることになる。
【００７３】
本実施の形態では、過去のシステム状況を表すデータのうち、現在（＝任意に選択される時点）の待ち搬送物数に最も近い値を示し、尚且つ、その中で平均搬送工期が最も短い値を示すデータの搬送車数を最適搬送車数と決定し、この最適搬送車数とメイン搬送路２０２への予備搬送車２０８の投入、またはメイン搬送路２０２からの予備搬送車２０８の撤去を決定する。これにより、メイン搬送路２０２に在る搬送車の数を調整し、搬送車同士の干渉頻度を低減させ、搬送工期の短縮化が可能となる。また、不要な予備搬送車２０８を稼働させないことにより、従来よりも、搬送システムの稼働に要する消費電力を抑制し、搬送車の使用寿命を伸ばすことが可能となる。
【００７４】
また、本実施の形態では、前述の如く、待ち搬送物数の変動傾向を考慮して、メイン搬送路２０２への予備搬送車２０８の投入、またはメイン搬送路２０２からの予備搬送車２０８の撤去を決定する。これにより、搬送システム２００内の搬送状況とリンクして、メイン搬送路１０２に在る搬送車（搬送車２０７、予備搬送車２０８）の数を調整することが可能となり、更なる搬送車同士の干渉頻度の低減、引いては、搬送工期の短縮化が可能となる。
【００７５】
【発明の効果】
本発明によって、搬送システム内の搬送状況に応じて、搬送路への投入または搬送路からの撤去を行い、搬送車等、搬送路に在る搬送体の数を調整することが可能となる。従って、必要数分の搬送体だけを用いて搬送物の搬送を行うことができ、搬送体同士の干渉頻度を低減させ、搬送工期を短縮化することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に関係する搬送システムの全体図。
【図２】本発明の第１及び第２の実施の形態に関係する、搬送システムの稼働状況を表すデータ。
【図３】本発明の第１の実施の形態に関係する、予備搬送車の投入・撤去を決定する手順を表すフローチャート。
【図４】本発明の第２の実施の形態に関係する、搬送システムの全体図である。
【図５】本発明の第２の実施の形態に関係する、予備搬送車の投入・撤去を決定する手順を表すフローチャート。
【図６】従来の搬送システムの全体図。
【図７】従来の搬送システムに関係するフローチャート。
【符号の説明】
１００、２００、３００・・・搬送システム
１０１、２０１、３０１・・・搬送作業ポイント
１０２、２０２、３０２・・・メイン搬送路
１０３、２０３、３０３・・・待機用搬送路
１０４、２０４、３０４・・・処理装置
１０５、２０５、３０５・・・搬送物
１０６、２０６、３０６・・・搬送車制御装置
１０７、２０７、３０７・・・搬送車
１０８、２０８、３０８・・・予備搬送車
１０９、２０９・・・システム状況記憶装置、
１１０、２１０・・・最適搬送車数決定部
１１１、２１１・・・搬送車投入・撤去決定部、
１１２・・・予想搬送量算出装置
１１３・・・必要台数データ記憶装置
１１４、２１２・・・待ち搬送物数変動記憶装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conveyance system used in a production line or the like, and particularly relates to the introduction and removal of a conveyance body according to the state of the production line.
[0002]
[Prior art]
Hereinafter, a conventional technique will be described using a semiconductor wafer transfer system as an example.
[0003]
As shown in FIG. 6, in the conventional semiconductor wafer transfer system 300, a main transfer path 302 connecting a plurality of transfer work points 301 and a transfer path connected to the main transfer path 302 are run from a standby transfer path 303. Each processing unit 304 that forms a path and processes a transferred wafer is installed along the periphery of the main transfer path 302 at a position corresponding to a plurality of transfer work points 301. In this transfer system 300, a semiconductor wafer (hereinafter referred to as a wafer) is transferred in a main transfer path 302 as a transfer object 305 stored in a storage container (= pod). The conveyed product 305 is loaded on the conveyance vehicle 307 controlled by the conveyance vehicle control device 306 and conveyed on the main conveyance path 302. In addition, a standby transporting vehicle 308 is prepared in the standby transporting path 303 and receives a transporting command from the transporting vehicle control device 306 and is appropriately put into the main transporting path 302 to supplement the number of transporting vehicles 307.
[0004]
In the conventional transfer system 300, as shown in FIG. 6, a margin several times as large as the transfer amount at the design stage is estimated, and a transfer vehicle (= transfer vehicle 307, spare transfer vehicle 308) is placed in the main transfer path 302. Has been introduced. For this reason, the main transfer path 302 is loaded regardless of whether it is necessary for wafer transfer work, forwarding work, or the like, and with respect to the transfer amount of the actual transfer object (= storage container storing the wafer). More than necessary, there are many transport vehicles (= transport vehicles 307, spare transport vehicles 308).
[0005]
In such a transfer system, as shown in FIG. 7, the transfer command issued from the transfer vehicle controller 306 is assigned to the transfer vehicle 307 and the preliminary transfer vehicle 308 regardless of whether or not the wafer is actually transferred. It has been. For this reason, even if the standby transmission path 303 is provided, if a large number of conveyance commands are temporarily generated, the number of loaded conveyance vehicles (= conveyance vehicles 307 and spare conveyance vehicles 308) is merely increased. In the main conveyance path 302, interference between the conveyance vehicles (= the conveyance vehicle 307 and the preliminary conveyance vehicle 308) further increases. Also, the transport vehicle (= the transport vehicle 307 and the spare transport vehicle 308) once entered into the main transport path 302 is not removed from the main transport path 302 unless work such as charging or maintenance is performed.
[0006]
In such a situation, when a conveyance command is issued from the conveyance vehicle control device 306, the conveyance vehicle 307 that performs conveyance is prevented from performing the conveyance operation and the forwarding operation by the preliminary conveyance vehicle 308 that does not perform conveyance. Become. Therefore, there arises a problem in that it leads to a delay in the transfer work period of the transferred object (= the storage container storing the wafer), and in turn the delay in the semiconductor device production work period. Further, by operating the unnecessary auxiliary transport vehicle 308 in the main transport path 302, a large amount of power (= electric power) is required for operating the transport system 300, and when it is unnecessary, the preliminary transport vehicle 308 is used. As a result, the wheels, motors, and the like of the transport vehicle operating as the preliminary transport vehicle 308 are excessively consumed, and eventually the service life of each transport vehicle is shortened, resulting in a problem of economic cost.
[0007]
[Problems to be solved by the invention]
As described above, in the conventional transfer system, without managing the transfer amount of the transfer object (for example, the storage container storing the wafer) and the number of transfer vehicles necessary for transferring the transfer object, The transport system is operating. Accordingly, since the frequency of interference between the transport vehicles increases accordingly, each transport vehicle spends extra time on the transport work or forwarding work, and the transport work period of the transported goods in the transport car as a whole increases. There is a problem that it leads to a delay in the production period of equipment and the like.
[0008]
Therefore, the object of the present invention is to manage the transport amount of the transport object and the number of transport vehicles necessary for transporting the transport object in the transport system, and to reduce the transport period of the entire transport vehicle than before. It is to control to be shortened and to be efficient.
[0009]
[Means for Solving the Problems]
The present invention relates to a transport system used in a production line or the like, and provides a transport system and a control method for the transport system that perform loading and unloading of a transport body according to the transport status of a transported object.
[0011]
The present invention also includes a transport path, a transport body that moves along the transport path and transports a transported object,
A transport state control unit that controls the transport body, a system status storage unit that stores data related to the transport body and the transported object for each predetermined period, and the data at any time point with reference to the data Determining the optimum number of the transport bodies required for transporting the transported object, and calculating the difference between the optimum number and the number of transport bodies existing in the transport path at the arbitrary time point; and Referring to the calculation result of the optimum transport body number determination unit, the transport body insertion / removal instructing the transport body control unit to input the transport body into the transport path or to remove the transport body from the transport path. From the data stored in the determination unit and the system status storage unit, it is the same as the number of transport objects that are the same as the number of transport bodies in the transport path at an arbitrary time and are waiting for transport at the arbitrary time. Select the data that shows the closest value and show in this data An estimated transport amount calculation unit that calculates the actual transport number as an expected transport amount, and a necessary number data storage unit that stores the number of necessary transport members with respect to the transport number of the transported object, and the optimal transport body number The deciding unit selects the number of conveyance times corresponding to the expected conveyance amount calculated by the expected conveyance amount calculation unit from the necessary number data storage unit, and conveys the number of conveyance bodies corresponding to the conveyance number. The optimum number of bodies, and the difference between the optimum number and the number of transport bodies at the arbitrary time point is calculated, and the transport body insertion / removal determination unit refers to the calculation result, and the transport path It is possible to provide a transport system characterized by instructing the transport body control unit to input the transport body into the transport path or to remove the transport body from the transport path.
[0012]
The present invention also includes a transport path, a transport body that moves along the transport path and transports a transported object,
A transport body control unit that controls the transport body, a system status storage unit that stores data related to the transport body and the transported object for each predetermined period, and the transport required for transporting the transported object at an arbitrary time point An optimum number of conveyance bodies is determined, and an optimum conveyance number determination unit that calculates a difference between the optimum number and the number of the conveyance bodies existing in the conveyance path at the arbitrary time point, and the optimum conveyance number determination unit. A transfer body insertion / removal determination unit that instructs the transfer body control unit to input the transfer body to the transfer path or to remove the transfer body from the transfer path, The optimum transported body number determining unit indicates the number of waiting transported objects closest to the number of transported objects waiting to be transported at the arbitrary time from the data stored in the system status storage unit, and Select the data with the shortest average transportation period, The number and determining the optimum number of the carrier required for conveying the conveyance object at the arbitrary time point can provide a transport system which is characterized in the transport of data.
[0014]
In addition, the present invention provides a transport system having a transport path, a transport body that moves along the transport path and transports a transported object, and a transport body control unit that controls the transport body. A process of storing data relating to a body and the transported object as actual data of the transport system, and from the actual data, the number of transport bodies present in the transport path at an arbitrary time point is the same, and A process of selecting data having a value closest to the number of transported objects waiting to be transported at the arbitrary time point on the transport path, and the actual number of transports of the selected data are determined by the process at the arbitrary time point. The process of calculating the expected transport amount of the transported object and the number of transport bodies required for the expected transport amount are determined as the optimum number of transport bodies required for transporting the transported object at the arbitrary time point, and the transport body The optimal number of Refer to the process of calculating the difference between the number of transport bodies in the transport path at the point of time, the difference between the optimal number of transport bodies and the number of transport bodies in the transport path at the arbitrary time point And a method for instructing the transport body control unit to insert the transport body into the transport path or to remove the transport body from the transport path. can do.
[0015]
In addition, the present invention provides a transport system having a transport path, a transport body that moves along the transport path and transports a transported object, and a transport body control unit that controls the transport body. The process of storing the data related to the body and the transported object as the actual data of the transport system, and from the actual result data, is closest to the number of the transported objects waiting to be transported at an arbitrary time in the transport path. Data having the shortest average transport work period of the transported object is selected, and the number of transport bodies included in the data is determined as the optimum number of transport bodies required for transporting the transported object at the arbitrary time point. Determining the difference between the optimal number of transport bodies and the number of transport bodies present in the transport path at the arbitrary time, the optimal number of transport bodies, and the arbitrary time point Of the transport body in the transport path The transfer system has a process of instructing the transfer body control unit whether to load the transfer body into the transfer path or to remove the transfer body from the transfer path. A control method can be provided.
[0016]
The present invention adjusts the number of transport bodies, such as a transport vehicle, present in the transport path by loading or unloading the transport body from the transport path according to the transport status in the transport system. Accordingly, it is possible to transport the transported object using only the necessary number of transport bodies, reduce the frequency of interference between the transport bodies, and shorten the transport period.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
In the process of manufacturing a semiconductor device, wafers are frequently transferred using a transfer body such as a transfer vehicle between processing apparatuses that process substrates such as semiconductor wafers. In the present embodiment, such a transfer of a semiconductor wafer is taken as an example, and a transfer system and a control method of the transfer system will be described with reference to FIGS.
[0018]
As shown in FIG. 1, a semiconductor wafer transfer system 100 includes a main transfer path 102 that connects a plurality of transfer work points 101 and a standby transfer path 103 connected to the main transfer path 102. Has a road.
[0019]
The processing device 104 or the conveyed product storage device is disposed at a predetermined position facing the transfer work point 101 and along the outer periphery of the main transfer path 102. Further, the wafer is transferred through the main transfer path 102 while being held inside the transfer object 105 so as to be loaded into each processing apparatus 104 (or transfer object storage apparatus). For the transfer object 105, a so-called wafer transfer pod or the like that can hold and store wafers in each lot (one lot is about 24 wafers) can be used.
[0020]
In this embodiment, as shown in FIG. 1, a loop-shaped conveyance path is used for the main conveyance path 102, but a lattice-shaped conveyance path or the like can also be used, and the shape is not particularly limited. Shall.
[0021]
As shown in FIG. 1, a transport vehicle 107 travels on the main transport path 102 based on the content of a command issued from the transport vehicle control device 106, and a standby transport vehicle 108 is prepared on the standby travel path 103. .
[0022]
The transport vehicle 107 performs work related to transport of the transported object 105 based on a transport command from the transport vehicle control device 106. For example, the transfer vehicle 107 performs an operation (= transfer operation) of loading the transfer object 105 holding the wafer inside and transferring it to each processing apparatus 104 (or transfer object storage apparatus). Further, the transport vehicle 107 may perform an operation of traveling on the main transport path 102 without loading the transported object 105 (= forwarding work) in order to receive the transported object 105 in the processing device 104 (or the transported object storage device). is there. On the other hand, when there is a shortage in the number of transporting vehicles 107, the preliminary transporting vehicle 108 is appropriately introduced from the standby transporting path 103 into the main transporting path 102 based on the transporting command of the transporting vehicle control device 106.
[0023]
In the present embodiment, as shown in FIG. 1, the transport vehicle control device 106 is provided with a system status storage device 109, an optimal transport vehicle number determination unit 110, and a transport vehicle insertion / removal determination unit 111. The transport vehicle control device 106 is connected to an expected transport amount calculation device 112, a necessary number data storage device 113, and a waiting transport number variation storage device 114.
[0024]
The optimum conveyance vehicle number determination unit 110 is a program for determining the optimum conveyance vehicle number, and the conveyance vehicle introduction / removal determination unit 111 is the introduction of the preliminary conveyance vehicle 108 to the main conveyance path 102 or the main conveyance path 102. It is assumed that a program for determining removal of the spare transport vehicle 108 from the vehicle is included.
[0025]
As shown in FIG. 2A, the system status storage device 109 stores various information (data) indicating the transport status of the transport system 100 as system status data. The system status data includes the number of (vehicles) of the transport vehicles (the transport vehicles 107 and the spare transport vehicles 108) existing in the transport system 100, and the actual transport of the transported object 105 actually transported by the transport system 100 for each predetermined period. The number, the number of transported objects 105 waiting to be transported in the transport system 100, the average transport work period (unit: sec), etc. are extracted as main information (data) from a host computer (not shown in particular), and the system It is stored in the status storage device 109 as needed and accumulated as past performance data. Further, the system status data can be stored at any time by selecting an arbitrary period unit such as one hour unit or one day unit. In this embodiment, as shown in FIG. 2A, data is stored in units of one day.
[0026]
Further, as shown in FIG. 2B, the necessary number data storage device 113 is created based on the result of the simulation and the number of transport vehicles (vehicles) desired by the user. Data representing the relation of “number” is stored. The data on the number of necessary (vehicles) of the transporting vehicles 107 may be set in advance by the user, or may be updated and stored as needed from the result obtained by performing the simulation.
[0027]
In the following, with reference to FIG. 3, the procedure for determining the optimum number of transported vehicles (units) by the optimum transported vehicle number determining unit 110 based on the expected transport amount of the transported object that is held inside and loaded is described. To do.
[0028]
First, the optimum transport vehicle number determination unit 110 sets the number of transported objects 105 waiting to be transported as the information indicating the current state, that is, the current state of the transport system 100 (= a time point arbitrarily selected), The host computer is inquired about the number of vehicles (conveyance vehicles 107, spare conveyance vehicles 108) (= step 1).
[0029]
Next, the predicted transport amount calculation device 112 compares the data representing the current status with the same number of transport vehicles (vehicles) from the past system status data stored in the system status storage device 109. The system status data indicating the closest number of waiting conveyances is retrieved (= step 2).
[0030]
Next, the predicted transport amount calculation device 112 calculates the actual transport count indicated in the retrieved system status data as the predicted transport amount of the current transported object 105 (= step 3). In this case, if there is only one data that matches the number of transported vehicles (cars) and the number of waiting transported items, one calculation result is selected as the expected transporting amount. When there are a plurality of matching data, for example, a range is given to the calculation result such as 100 to 120 (times / hr (= number of times of conveyance per unit time)), and this is set as the expected conveyance amount.
[0031]
Next, the optimum transport vehicle number determination unit 109 determines the optimal number of transport vehicles (vehicles) by comparing the expected transport amount with the necessary number data in the necessary number data storage device 113 (= step 4). As shown in FIG. 2B, the necessary number data storage device 113 is created based on the result of the simulation and the number of transport vehicles (vehicles) desired by the user. Data representing the relationship is stored. Therefore, from this data, the number of times of conveyance that matches the value of the expected conveyance amount is searched, and the corresponding number of necessary conveyance vehicles (vehicles) is determined as the optimum number of conveyance vehicles (vehicles).
[0032]
Next, the optimal transport vehicle number determination unit 109 calculates the difference between the optimal transport vehicle (car) number and the current transport vehicle (transport car 107, spare transport car 108) number of cars in the main transport path 102. (= Step 5).
[0033]
Next, the waiting conveyance number fluctuation storage device 114 is in the conveyance system 100 and stores the fluctuation tendency of the number of conveyance objects waiting to be conveyed as fluctuation data of the waiting conveyance number. Whether the vehicle is in an increasing tendency, a decreasing tendency, or a flat (= substantially constant) tendency is transmitted to the transport vehicle insertion / removal determination unit 111. (= Step 6)
Next, the transport vehicle introduction / removal determination unit 111 determines whether or not the preliminary transport vehicle 108 needs to be inserted into or removed from the main transport path 102 (= step 7).
[0034]
First, a procedure (= step 7-1) until the transport vehicle insertion / removal determination unit 111 determines to input the spare transport vehicle 108 to the main transport path 102 will be described.
[0035]
For example, when “the optimal number of transport vehicles (vehicles) = the number of (current) transport vehicles (the transport vehicles 107 and the spare transport vehicles 108, hereinafter omitted)”, the transport can be performed with the current number of transport vehicles. , It is determined that “the auxiliary transport vehicle 108 is not put into the main transport path 102”. When “the optimum number of transport vehicles (vehicles)> the current number of transport vehicles (vehicles)”, the variation tendency of the number of waiting transport vehicles is taken into consideration. In other words, even when it is necessary to put in the spare transport vehicle 108, if the number of waiting transport vehicles tends to decrease, it is determined that “the standby transport vehicle 108 is not thrown into the main transport path 102” and the waiting transport is performed. If the change in the number of objects is in an increasing trend or is in a flat state (= substantially constant), it is determined that “the spare transport vehicle 108 is introduced into the main transport path 102”.
[0036]
In this way, in consideration of the fluctuation tendency of the number of waiting conveyance objects, it is possible to link the state of the conveyance system 100 with high accuracy, and the preliminary conveyance vehicle 108 can be input accurately, and further, the frequency of interference between the conveyance vehicles is reduced. The conveyance work period can be shortened.
[0037]
If the waiting conveyance number variation storage device 114 is not provided, the conveyance vehicle insertion / removal determination unit 110 does not consider the variation tendency of the number of waiting conveyance items, and conveys the current number of conveyance vehicles (vehicles). If this is not possible, it is determined that the necessary number of (preliminary) spare transport vehicles 108 are to be inserted.
[0038]
Next, a procedure (step 7-2) until the transport vehicle insertion / removal determination unit 111 determines the removal of the spare transport vehicle 108 from the main transport path 102 will be described.
[0039]
When “the optimum number of transport vehicles (vehicles) = (the number of transport vehicles 107, spare transport vehicles 108, hereinafter omitted)”, the current number of transport vehicles (vehicles) is required. , “Do not insert or remove the spare transport vehicle 108 from the main transport path 102”. In addition, when “the optimum number of transport vehicles (vehicles) <the current number of transport vehicles (cars)”, the fluctuation tendency of the number of waiting transport vehicles is considered. That is, when the number of waiting conveyance objects tends to increase, it is determined that “the preliminary conveyance vehicle 108 is not removed from the main conveyance path 102”, and the variation in the number of waiting conveyance objects is decreasing or flat (= approximately). If it is in the “constant” state, it is determined that “the spare transport vehicle 108 is removed from the main transport path 102”.
[0040]
In this way, in consideration of the fluctuation trend of the number of waiting conveyance objects, the preliminary conveyance vehicle 108 can be removed with high accuracy in linkage with the conveyance status of the conveyance system 100, and further, the interference frequency between the conveyance vehicles can be reduced. It is possible to shorten the conveyance work period.
[0041]
If the waiting conveyance number variation storage device 113 is not provided, the conveyance vehicle insertion / removal determination unit 111 does not consider the fluctuation tendency of the number of waiting conveyance items, and the number of conveyance vehicles (units) is smaller than the current number. If it is possible to carry the vehicle, it is decided to remove the spare conveyance vehicles 108 for the number of unnecessary (vehicles).
[0042]
Next, based on the determination result of the transport vehicle insertion / removal determination unit 111, the transport vehicle control device 106 assigns a transport command regarding insertion or removal to the preliminary transport vehicle 108, and the preliminary transport vehicle 108 " “Move” or “Move to standby runway 103” is started (= step 8).
[0043]
In the conventional transfer system, a margin several times as large as the transfer amount at the design stage is estimated, and the transfer vehicle is introduced into the main transfer path including the spare transfer vehicle. Further, when a transport command is assigned to a transport vehicle, the transport command is unconditionally assigned to an unnecessary spare transport vehicle simultaneously with the generation of the transport command. Therefore, the number of transport vehicles increases in the main transport path, and transport vehicles that perform transport and forwarding work are unnecessary, the path is blocked by a preliminary transport vehicle that does not have a transport command, the transport work period increases, and Will delay the production period.
[0044]
In the present embodiment, among the data representing the past system status, the actual transport number of data indicating the value closest to the current (= arbitrarily selected) waiting transport object number is determined as the expected transport amount, This is compared with the necessary transport vehicle (car) number data to determine whether the preliminary transport vehicle 108 is inserted into the main transport path 102 or removed from the main transport path 102. As a result, the number of transport vehicles on the main transport path 102 can be adjusted, the frequency of interference between the transport vehicles can be reduced, and the transport period can be shortened. Further, by not operating the unnecessary spare transport vehicle 108, it is possible to suppress the power consumption required for the operation of the transport system and to extend the service life of the transport vehicle as compared with the conventional case.
[0045]
Further, in the present embodiment, as described above, in consideration of the fluctuation tendency of the number of waiting conveyance objects, the auxiliary conveyance vehicle 108 is inserted into the main conveyance path 102 or the preliminary conveyance vehicle 108 is removed from the main conveyance path 102. To decide. As a result, it is possible to adjust the number of transport vehicles (transport vehicles 107 and spare transport vehicles 108) in the main transport path 102 in linkage with the transport status in the transport system 100. It is possible to reduce the frequency of interference and, in turn, shorten the conveyance work period.
(Second Embodiment)
In the present embodiment, as in the first embodiment, transfer of a semiconductor wafer is taken as an example, and a transfer system and a control method of the transfer system will be described with reference to FIGS. 4 and 5.
[0046]
As shown in FIG. 4, a semiconductor wafer transfer system 200 includes a main transfer path 202 connecting a plurality of transfer work points 201 and a standby transfer path 203 connected to the main transfer path 202. Have
[0047]
The processing device 204 (or the transported material storage device) faces the transport work point 201 and is disposed at a predetermined position along the outer periphery of the main transport path 202. Further, the wafer is transferred through the main transfer path 202 while being held inside the transfer object 205 so as to be loaded into the processing apparatus 204 (or transfer object storage apparatus). For the transfer object 205, a so-called wafer transfer pod or the like that can store wafers for each lot (about 24 wafers per lot) can be used.
[0048]
In this embodiment, as shown in FIG. 4, a loop-shaped conveyance path is used for the main conveyance path 202, but a lattice-shaped conveyance path or the like can also be used, and the shape is not particularly limited. Shall.
[0049]
As shown in FIG. 4, the transport vehicle 207 travels on the main transport path 202 based on the content of the command issued from the transport vehicle control device 206, and the standby transport vehicle 208 is prepared on the standby transmission path 203. The
[0050]
The transport vehicle 207 performs work related to transport of the transported object 205 based on a transport command from the transport vehicle control device 206. For example, the transfer vehicle 207 performs an operation (= transfer operation) of loading the transfer object 205 holding the wafer therein and transferring it to the processing apparatus 204 (or transfer object storage apparatus). In addition, the transport vehicle 207 may perform an operation of traveling on the main transport path 202 without loading the transport object 205 (= forwarding work) in order to receive the transport object 205 in the processing device 204. On the other hand, when there is a shortage in the number of transport vehicles 207 (the number of transport vehicles), the preliminary transport vehicle 208 is appropriately introduced from the standby transport path 203 to the main transport path 202 based on the transport command of the transport vehicle control device 206. The
[0051]
As shown in FIG. 4, the transport vehicle control device 206 is provided with a system status storage device 209, an optimal transport vehicle number determination unit 210, and a transport vehicle introduction / removal determination unit 211. In addition, a waiting conveyance number fluctuation storage device 212 is connected to the transport vehicle control device 206.
[0052]
The system status storage device 209, the transport vehicle insertion / removal determination unit 211, and the waiting transport number variation storage device 212 are the system status storage device 109, the optimal transport vehicle number determination unit 110 of (first embodiment), and It has the same structure as each of the transport vehicle insertion / removal determination unit 111 and acts similarly to the transport system 200.
[0053]
As shown in FIG. 2A, the system status storage device 209 stores various information (data) indicating the transport operation status of the transport system 200 as system status data. This system status data includes the number of (vehicles) of the transport vehicles (transport vehicle 207, spare transport vehicle 208) existing in the transport system 200 and the actual transport of the transported product 205 actually transported by the transport system 200 for each predetermined period. The main information (data) such as the number, the number of waiting transported objects 205 waiting to be transported in the transport system 200, and the average transport work period (unit: sec) are extracted from the host computer (not shown in particular), It is stored in the system status storage device 209 at any time and accumulated as performance data. The system status data can be stored at any time by selecting an arbitrary period unit such as one hour unit or one day unit. In this embodiment, as shown in FIG. 2A, data is stored in units of one day.
[0054]
Hereinafter, referring to FIG. 5, a procedure for determining the optimum number of transported vehicles (units) by the optimum transported vehicle number determining unit 210 with reference to the average transport work period of the transported objects that are held inside and stored therein explain.
[0055]
In addition, the average transport period is the total of the time (= transport period) required for transport for transported objects that have been transported within a predetermined period (eg, 1 hour, 1 day, or 1 month). Averaged. In this case, the time required for transport includes the time for assigning and inputting a transport command to the transport vehicle, the time required for the transport vehicle to transport the transported object, and the transporting body (without loading the transported object). This includes the time for work.
[0056]
First, the optimum transport vehicle number determination unit 210 sets the number of transported objects 205 waiting to be transported as information representing the current state, that is, the current state of the transport system 200 (= when it is arbitrarily selected). (= Step 1).
[0057]
Next, the optimal transport vehicle number determination unit 210 compares the current state (= arbitrarily selected time point) with the data representing the state, and from the past system state data stored in the system state storage device 209, The system status data which is closest to the current number of waiting conveyance objects and which has the shortest average conveyance work period is searched (= step 2).
[0058]
Next, the optimum transport vehicle number determination unit 210 determines the number of transport vehicles (cars) indicated in the retrieved data as the optimal (car) number (= step 3).
[0059]
Next, the difference from the number of (cars) in the current transport vehicle (the transport vehicle 207 and the spare transport vehicle 208) in the main transport path 202 is calculated (= step 4).
[0060]
Next, the waiting conveyance number fluctuation storage device 212 stores the fluctuation tendency of the waiting conveyance number in the conveyance waiting state in the conveyance system 200 as waiting conveyance number fluctuation data, and the fluctuation of the waiting conveyance number is changed. Whether the vehicle is in an increasing trend, a decreasing trend, or is in a flat state (= substantially constant) is transmitted to the transport vehicle insertion / removal determination unit 211. (= Step 5)
Next, the transport vehicle introduction / removal determination unit 211 determines whether or not the preliminary transport vehicle 208 needs to be inserted into or removed from the main transport path 202 (= step 6).
[0061]
Here, in the same manner as in the first embodiment, it is determined whether or not it is necessary to insert and remove the spare transport vehicle 208 in consideration of the fluctuation tendency of the number of waiting transport materials that are waiting for transport in the transport system 200. To do. That is, the transfer vehicle insertion / removal determination unit 211 considers the fluctuation tendency of the number of waiting transfer objects, and the transfer vehicle (the transfer vehicle 207 and the spare transfer vehicle 208) in which the optimal transfer vehicle number is currently in the main transfer path 202. When the number of (conveyors) is larger than the number of (vehicles), it is determined that the auxiliary conveyance vehicle 208 is to be inserted into the main conveyance path 202, and the optimum conveyance number of the conveyance vehicles (conveyance vehicles 207, 207, When the number of (preliminary conveyance vehicles 208) is smaller than (the number of), the removal of the preliminary conveyance vehicles 208 from the main conveyance path 202 is determined.
[0062]
The procedure for determining the introduction and removal of the preliminary transport vehicle 208 is shown in FIG.
[0063]
First, a procedure (= step 6-1) until the transport vehicle insertion / removal determination unit 211 determines to input the spare transport vehicle 208 to the main transport path 202 will be described.
[0064]
For example, when “the optimum number of transport vehicles (vehicles) = the number of (current) transport vehicles (transport vehicle 207, spare transport vehicle 208, hereinafter omitted)”, it is possible to transport with the current number of transport vehicles. , It is determined that “the auxiliary transport vehicle 208 is not put into the main transport path 202”. When “the optimum number of transport vehicles (vehicles)> the current number of transport vehicles (vehicles)”, the variation tendency of the number of waiting transport vehicles is taken into consideration. That is, even when it is necessary to put in the preliminary transport vehicle 208, if the number of waiting transport items tends to decrease, it is determined that “the preliminary transport vehicle 208 is not inserted into the main transport path 202”, and the waiting transport material When the fluctuation of the number is in an increasing trend or is in a sideways (= substantially constant) state, it is determined that “the spare transport vehicle 208 is introduced into the main transport path 202”.
[0065]
As described above, in consideration of the fluctuation tendency of the number of waiting conveyance objects, the preliminary conveyance vehicle 208 linked with the condition of the conveyance system 200 can be accurately introduced, and the frequency of interference between the conveyance vehicles can be further reduced. Can be shortened.
[0066]
If the waiting conveyance number variation storage device 212 is not provided, the conveyance vehicle insertion / removal determination unit 210 does not consider the variation tendency of the number of waiting conveyance items, and conveys the current number of conveyance vehicles (vehicles). If this is not possible, it is determined to input as many spare transport vehicles 208 as necessary (units).
[0067]
Next, a procedure (step 6-2) until the transport vehicle insertion / removal determination unit 211 determines to remove the spare transport vehicle 208 from the main transport path 202 will be described.
[0068]
For example, if “the optimum number of transport vehicles (vehicles) = the number of current transport vehicles (transport vehicles 207, spare transport vehicles 208, hereinafter omitted)”, the number of current transport vehicles (vehicles) is required. It is determined that “the removal of the spare transport vehicle 208 from the main transport path 202 is not performed”. In addition, when “the optimum number of transport vehicles (vehicles) <the current number of transport vehicles (cars)”, the fluctuation tendency of the number of waiting transport vehicles is considered. That is, when the number of waiting conveyance objects tends to increase, it is determined that “the removal of the spare conveyance vehicle 208 from the main conveyance path 202 is not performed”, and the variation in the number of waiting conveyance objects is decreasing or flat ( (= Substantially constant state), it is determined that “the preliminary transport vehicle 208 is removed from the main transport path 202”.
[0069]
As described above, in consideration of the fluctuation tendency of the number of waiting conveyance objects, it becomes possible to remove the preliminary conveyance vehicle 208 linked with the condition of the conveyance system 200 with high accuracy, further reducing the interference frequency between the conveyance vehicles, and the conveyance work period. Can be shortened.
[0070]
If the waiting conveyance number variation storage device 212 is not provided, the conveyance vehicle insertion / removal determination unit 211 does not consider the variation tendency of the number of waiting conveyance items, and the number of (number of) conveyance vehicles is smaller than the current number. If it is possible to carry the vehicle, the removal of the unnecessary (vehicle) number of spare conveyance vehicles 208 is determined.
[0071]
Next, based on the determination result of the transport vehicle insertion / removal determination unit 211, the transport vehicle control device 206 assigns a transport command to the preliminary transport vehicle 208 to be inserted or removed. "Movement" or "movement to standby transmission path 203" is started (= step 7).
[0072]
In the conventional transfer system, a margin several times as large as the transfer amount at the design stage is estimated, and the transfer vehicle is introduced into the main transfer path including the spare transfer vehicle. Further, when a transport command is assigned to a transport vehicle, the transport command is unconditionally assigned to an unnecessary spare transport vehicle simultaneously with the generation of the transport command. Therefore, the number of transport vehicles increases on the main transport path, and transport vehicles that perform transport and forwarding work are unnecessary, the path is blocked by a preliminary transport vehicle that does not have a transport command, and the transport period increases. Will delay the production period.
[0073]
In this embodiment, among the data representing the past system status, the value closest to the current (= arbitrarily selected) waiting conveyance number is shown, and the average conveyance period is shortest among them. The number of transporting vehicles of the data indicating the value is determined as the optimal transporting vehicle number, and the optimal transporting vehicle number and the auxiliary transporting vehicle 208 are inserted into the main transporting path 202, or the preliminary transporting vehicle 208 is removed from the main transporting path 202. decide. As a result, the number of transport vehicles on the main transport path 202 is adjusted, the frequency of interference between the transport vehicles is reduced, and the transport period can be shortened. Further, by not operating the unnecessary spare transport vehicle 208, it is possible to suppress the power consumption required for the operation of the transport system and extend the service life of the transport vehicle as compared with the conventional case.
[0074]
Further, in the present embodiment, as described above, in consideration of the fluctuation tendency of the number of waiting conveyance objects, the auxiliary conveyance vehicle 208 is inserted into the main conveyance path 202 or the preliminary conveyance vehicle 208 is removed from the main conveyance path 202. To decide. Thereby, it is possible to adjust the number of transport vehicles (transport vehicle 207, spare transport vehicle 208) in the main transport path 102 in linkage with the transport status in the transport system 200. It is possible to reduce the frequency of interference and, in turn, shorten the conveyance work period.
[0075]
【The invention's effect】
According to the present invention, it is possible to adjust the number of transport bodies such as a transport vehicle or the like in the transport path by performing input to the transport path or removal from the transport path according to the transport status in the transport system. Accordingly, it is possible to transport the transported object using only the necessary number of transport bodies, reduce the frequency of interference between the transport bodies, and shorten the transport period.
[Brief description of the drawings]
FIG. 1 is an overall view of a transport system according to a first embodiment of the present invention.
FIG. 2 shows data representing the operating status of the transport system related to the first and second embodiments of the present invention.
FIG. 3 is a flowchart showing a procedure for determining insertion / removal of a spare transport vehicle related to the first embodiment of the present invention.
FIG. 4 is an overall view of a transport system related to a second embodiment of the present invention.
FIG. 5 is a flowchart showing a procedure for determining insertion / removal of a spare transport vehicle related to the second embodiment of the present invention.
FIG. 6 is an overall view of a conventional transport system.
FIG. 7 is a flowchart related to a conventional transport system.
[Explanation of symbols]
100, 200, 300 ... conveying system
101, 201, 301 ... transporting work points
102, 202, 302 ... main conveyance path
103, 203, 303... Standby transport path
104, 204, 304 ... processing device
105, 205, 305 ... Conveyed items
106, 206, 306 ... Conveyor control device
107, 207, 307...
108, 208, 308 ... Preliminary transport vehicle
109, 209 ... system status storage device,
110, 210 ... Optimum conveyance vehicle number determination unit
111, 211 ... transportation vehicle introduction / removal decision unit,
112 ... Expected transport amount calculation device
113 ... Necessary number data storage device
114, 212 ... Waiting conveyance number fluctuation storage device

Claims

A transport path;
A transport body for moving the transport path and transporting the transported object;
A transport body control unit for controlling the transport body;
A system status storage unit that stores data related to the transport body and the transported object for each predetermined period;
Referring to the data, the optimum number of the transport bodies required for transporting the transported object at an arbitrary time point is determined, and the optimal number and the number of transport bodies existing in the transport path at the arbitrary time point An optimal number-of-conveyance-number determining unit for calculating the difference;
Referring to the calculation result of the optimum transport body number determination unit, the transport body input unit that instructs the transport body control unit to input the transport body into the transport path or to remove the transport body from the transport path. A removal decision section;
From the data stored in the system status storage unit, the value that is the same as the number of transport bodies in the transport path at an arbitrary time and the closest value to the number of transported objects waiting to be transported at the arbitrary time is shown. An expected conveyance amount calculation unit that selects data and calculates the actual conveyance number indicated in the data as an estimated conveyance amount;
A necessary number data storage unit that stores the number of necessary conveyances with respect to the number of conveyances of the conveyance object,
The optimum transport body number determination unit selects the number of transport times corresponding to the expected transport amount calculated by the expected transport amount calculation unit from the required number data storage unit, and transports corresponding to the transport number The number of bodies is the optimum number of transport bodies, and the difference between the optimum number and the number of transport bodies at the arbitrary time is calculated, and the transport body insertion / removal determination unit refers to the calculation result. The transfer system is configured to instruct the transfer body control unit to input the transfer body to the transfer path or to remove the transfer body from the transfer path.

A transport path;
A transport body for moving the transport path and transporting the transported object;
A transport body control unit for controlling the transport body;
A system status storage unit that stores data related to the transport body and the transported object for each predetermined period;
Optimal transport for determining an optimum number of the transport bodies required for transporting the transported object at an arbitrary time point and calculating a difference between the optimum number and the number of transport bodies present on the transport path at the arbitrary time point A body number determination unit;
Referring to the calculation result of the optimum transport body number determination unit, the transport body insertion / removal instructing the transport body control unit to input the transport body into the transport path or to remove the transport body from the transport path. A determination unit,
The optimum transported body number determining unit indicates the number of transported objects closest to the number of transported objects waiting to be transported at the arbitrary time from the data stored in the system status storage unit, and the transported objects The data having the shortest average transport period is selected, and the number of transport bodies of this data is determined as the optimum number of transport bodies required for transporting the transported object at the arbitrary time point.

The conveyance system further includes a waiting conveyance number variation storage unit that stores a variation tendency of the number of conveyance objects in the conveyance waiting state in the conveyance path,
The transfer body insertion / removal determination unit refers to the change tendency of the number of transfer objects stored in the waiting transfer number fluctuation storage unit, and inputs the transfer body to the transfer path or the transfer path from the transfer path. conveying system according to claim 1 or 2, characterized in that the removal of the carrier, instructing said carrier control unit.

The transporter insertion / removal determining unit refers to the variation trend of the transported object number stored in the waiting transported object number fluctuation storage unit, and when the transporting body needs to be input to the transport path, and The conveyance system according to claim 3 , wherein when the number of conveyance objects waiting in the conveyance path is constant or increasing, the conveyance system is determined to be loaded into the conveyance path.

The transporter insertion / removal determining unit refers to the variation trend of the transported object number stored in the waiting transported object number variation storage unit, and when the transporter needs to be removed from the transport path, and 4. The transport system according to claim 3 , wherein when the number of transported objects waiting in the transport path is constant or in a decreasing tendency, removal of the transport body from the transport path is determined.

In a conveyance system having a conveyance path, a conveyance body that moves along the conveyance path and conveys a conveyance object, and a conveyance body control unit that controls the conveyance body,
For each predetermined period, a process of storing data related to the transport body and the transported object as actual data of the transport system;
From the result data, the value that is the same as the number of the transport bodies that are present in the transport path at an arbitrary time and that is closest to the number of transport objects that are waiting for transport at the arbitrary time in the transport path. The process of selecting the data to have,
A process of calculating the actual number of times of conveyance that the selected data has as an expected conveyance amount of the conveyance object at the arbitrary time point,
The number of transport bodies required for the expected transport amount is determined as the optimal number of transport bodies required for transporting the transported object at the arbitrary time point, and the transport path at the optimal number of transport bodies and the arbitrary time point The process of calculating the difference from the number of carriers in
Referring to the difference between the optimum number of the transport bodies and the number of transport bodies existing in the transport path at the arbitrary time point, the transport bodies are thrown into the transport path, or the transport bodies are removed from the transport path. And a process of instructing the transport body control unit whether to remove the transport system.

In a conveyance system having a conveyance path, a conveyance body that moves along the conveyance path and conveys a conveyance object, and a conveyance body control unit that controls the conveyance body,
For each predetermined period, a process of storing data related to the transport body and the transported object as actual data of the transport system;
From the record data, the data having the closest value to the number of the transported objects that are waiting to be transported at an arbitrary time on the transport path and having the shortest average transport work period of the transported objects is selected, and this data A process of determining the number of transport bodies having the optimal number of transport bodies required for transporting the transported object at the arbitrary time point;
Calculating the difference between the optimal number of transport bodies and the number of transport bodies in the transport path at the arbitrary time point;
Referring to the difference between the optimum number of the transport bodies and the number of transport bodies existing in the transport path at the arbitrary time point, the transport bodies are thrown into the transport path, or the transport path from the transport path A control method for a transport system, comprising a step of instructing the transport body control unit whether to remove a body.

Whether to transfer the transport body to the transport path or to remove the transport body from the transport path is determined with reference to the variation tendency of the number of transported objects in the transport waiting state in the transport path. The method for controlling a transport system according to claim 6 or 7 , wherein:

The loading of the transport body into the transport path refers to a variation tendency of the number of transported objects in the transport waiting state in the transport path, and when the transport body needs to be loaded into the transport path, and 9. The method of controlling a transport system according to claim 8 , wherein the transport system is determined when the number of transported objects waiting for transport on the transport path is constant or increasing.

The removal of the transport body from the transport path refers to the variation tendency of the number of transported objects in the transport waiting state in the transport path, and the removal of the transport body from the transport path is necessary. 9. The method of controlling a transport system according to claim 8 , wherein the number is determined when the number of transported objects waiting for transport on the transport path is constant or decreasing.