一種支撐式管道檢測機(jī)器人的結(jié)構(gòu)和性能優(yōu)化設(shè)計含6張CAD圖

一種支撐式管道檢測機(jī)器人的結(jié)構(gòu)和性能優(yōu)化設(shè)計含6張CAD圖,一種,支撐,管道,檢測,機(jī)器人,結(jié)構(gòu),性能,優(yōu)化,設(shè)計,CAD 畢業(yè)設(shè)計題目：一種支撐式管道檢測機(jī)器人的結(jié)構(gòu)和性能優(yōu)化設(shè)計畢業(yè)設(shè)計要求及原始數(shù)據(jù)（資料）：1、原始數(shù)據(jù)（資料）： 管道檢測機(jī)器人適用的對象為管徑范圍在 250mm-350mm 的石油天然氣管道。管道環(huán)境通常可分為障礙管和無障礙管。 綜上，設(shè)計的管道檢測機(jī)器人的運(yùn)動需求主要有以下兩點： （1）順利越過以臺階為主的障礙管道。 序號 項目 參數(shù) 1 管徑范圍 250mm-350mm 2 運(yùn)動速度 0.05m/s 3 最小牽引力 300N 4 越障高度 10mm 5 過彎能力 90 度 6 摩擦系數(shù) 0.75 （2）順利通過以彎管為主的無障礙管道。設(shè)計參數(shù)如下： 對這種機(jī)器人進(jìn)行結(jié)構(gòu)建模，分析其結(jié)構(gòu)強(qiáng)度，結(jié)合對這種機(jī)器人的越障能力和過彎能力進(jìn)行分析，以質(zhì)量最小為優(yōu)化目標(biāo)進(jìn)行優(yōu)化。 2、畢業(yè)設(shè)計（論文）要求： （1）任務(wù)要求 全面了解設(shè)計任務(wù)書，掌握設(shè)計意圖，明確設(shè)計任務(wù)，根據(jù)原始數(shù)據(jù)和設(shè)計工況要求，分析并擬定管道機(jī)器人的總體方案，完成支撐式變徑機(jī)構(gòu)設(shè)計、行走機(jī)構(gòu)的設(shè)計、檢測機(jī)構(gòu)的設(shè)計；完成以上機(jī)構(gòu)的結(jié)構(gòu)設(shè)計的計算。繪制裝配圖、部件圖和部分零件圖。同時完成相應(yīng)的計算說明過程。主要任務(wù)如下： 畢業(yè)設(shè)計（論文）開題報告； 文獻(xiàn)綜述&外文翻譯； 設(shè)計、計算、繪制相應(yīng)設(shè)計內(nèi)容的技術(shù)圖紙； 畢業(yè)設(shè)計說明書。 （2）、時間進(jìn)度要求 序號 時間 周次 指導(dǎo)教師工作及要求 1 2021.3.22-2021.3.28 第 1 周 按任務(wù)書，查閱相關(guān)文獻(xiàn)、撰寫文獻(xiàn)綜述、翻譯外文資料 2 2021.3.29-2021.4.4 第 2 周 開題報告的攥寫 3 2021.4.5-2021.4.11 第 3 周 審核開題報告，進(jìn)行開題答辯 4 2021.4.12-2021.5.9 第 4-7 周 試驗研究或設(shè)計階段，繪制相關(guān)圖紙， 編寫設(shè)計說明書 5 2021.5.10-2021.5.16 第 8 周 畢業(yè)設(shè)計期中檢查 6 2021.5.17-2021.5.30 第 9-10周 修改相關(guān)圖紙，完善畢業(yè)設(shè)計說明書 7 2021.5.31-2021.6.6 第 11 周 論文查重、修改論文 8 2021.6.7-2021.6.13 第 12 周 打印裝訂、指導(dǎo)老師與評閱老師賦分、畢業(yè)答辯 學(xué)生應(yīng)交出的設(shè)計文件（論文）：設(shè)計成果要求：提交紙質(zhì)資料（打印和部分手工繪制圖紙）和電子文檔資料。圖紙使用 AutoCAD 軟件繪制，文件為.dwg 格式。設(shè)計說明書資料為.doc 格式。 1、畢業(yè)設(shè)計（論文）開題報告。 2、畢業(yè)設(shè)計說明書 1 份，字?jǐn)?shù) 2-2.5 萬字。按本科畢業(yè)設(shè)計（論文）撰寫規(guī)范執(zhí)行。 3、圖紙： (1) 總裝配圖（A0 號）1 張； (2) 關(guān)鍵部件圖（A2 號）2 張； (3) 零件圖（A3 號）不少于 3 張； 4、文獻(xiàn)綜述&外文翻譯：按山西能源學(xué)院本科畢業(yè)設(shè)計（論文）撰寫規(guī)范執(zhí)行。 (1) 文獻(xiàn)綜述：字?jǐn)?shù)不少于 3000 字； (2) 外文翻譯：外文翻譯必須與畢業(yè)設(shè)計課題相關(guān)，字?jǐn)?shù)不少于 5000 字， 并標(biāo)明文章出處。 主要參考文獻(xiàn)（資料）： 1 陳瀟.管道內(nèi)支撐式檢測機(jī)器人運(yùn)動控制與檢測研究.武漢大學(xué)，2018. 2 陳伶.六輪腿支撐式管內(nèi)螺旋行走機(jī)構(gòu)運(yùn)動學(xué)分析及性能研究.中北大學(xué)， 2016. 3 張云偉.煤氣管道檢測機(jī)器人系統(tǒng)及其運(yùn)動控制技術(shù)研究.上海交通大學(xué)， 2007. 4 楊彩霞.油氣管道機(jī)器人機(jī)構(gòu)設(shè)計及運(yùn)動控制研究.中國計量大學(xué)，2018. 5 黎華，倪進(jìn)飛，楊波.支撐式管內(nèi)移動機(jī)器人設(shè)計與管內(nèi)通過性試驗研究. 機(jī)械與電子，2017. 6 徐寶東.支撐輪式城市燃?xì)夤艿罊C(jī)器人結(jié)構(gòu)優(yōu)化與運(yùn)動特性研究.北京石油化工學(xué)院，2015. 7 張義.城市燃?xì)夤艿罊z測機(jī)器人測控系統(tǒng)研究.北京石油化工學(xué)院，2015. 8 ?？?管道檢測機(jī)器人的運(yùn)動控制研究.華南理工大學(xué)，2012. 9 李著信,蘇毅,呂宏慶,孟浩龍.管道在線檢測技術(shù)及檢測機(jī)器人研究.后勤工程學(xué)院學(xué)報，2006. 10 林國能.管道檢測機(jī)器人系統(tǒng)研制.北京郵電大學(xué)，2017. 11 王亦臣.一種新型管道機(jī)器人自適應(yīng)管徑機(jī)構(gòu).機(jī)器人技術(shù)與應(yīng)用，2017.雙輪鏈平面管道檢測機(jī)器人摘要介紹了一種新型的多傳感器管道檢測機(jī)器人，用于80-100mm管道的檢測。該機(jī)器人的特點是只需使用兩個輪鏈即可實現(xiàn)驅(qū)動和轉(zhuǎn)向功能。與普遍采用的三輪鏈條管道機(jī)器人相比，新設(shè)計允許簡單的機(jī)器人控制和方便的用戶界面，特別是在T形分支。作為另一個優(yōu)點，這種機(jī)器人的平面形狀允許在機(jī)器人的兩側(cè)安裝額外的傳感器。介紹了系統(tǒng)的運(yùn)動學(xué)和三種控制方式。最后，通過實驗驗證了該機(jī)器人系統(tǒng)的性能。關(guān)鍵詞:管道機(jī)器人；系統(tǒng)；運(yùn)動學(xué)I.緒論管道檢測機(jī)器人的功能可以描述為驅(qū)動、轉(zhuǎn)向、檢測和檢索。而用于直徑小于100mm管道檢測的機(jī)器人，在設(shè)計緊湊的轉(zhuǎn)向機(jī)構(gòu)和安裝磁探頭、超聲波探頭等傳感器檢測裂紋、破裂、泄漏等方面存在特殊困難。管道機(jī)器人機(jī)構(gòu)在機(jī)器人技術(shù)領(lǐng)域有著悠久的發(fā)展歷史，按其運(yùn)動模式可分為幾種基本形式。它們有輪式、尺蠖式、腿式、螺旋式、履帶式和被動式。其中輪式管道檢測機(jī)器人最為流行，1-8。然而，它們不適合在垂直路徑或在t分支操作。近10年來，人們對差動驅(qū)動型機(jī)構(gòu)9-11進(jìn)行了較為深入的研究。差動驅(qū)動類型通常有三個動力輪鏈。通過獨立控制每個鏈條的速度，機(jī)器人可以通過肘部和t型分支。然而，當(dāng)只使用一個機(jī)器人模塊時，有時會在T支9處發(fā)生奇異運(yùn)動。為了解決這一問題，已經(jīng)開發(fā)了幾種方法，如主動轉(zhuǎn)向關(guān)節(jié)機(jī)構(gòu)12-13或兩個機(jī)器人模塊9協(xié)作。然而，整個機(jī)器人系統(tǒng)的體積變得龐大。使用三個動力輪鏈的另一個缺點是沒有足夠的空間在機(jī)器人體內(nèi)安裝更多的傳感器，因為三個輪鏈占據(jù)了管道的大部分橫截面積，特別是直徑小于100mm的管道。目前，機(jī)器人身體前只安裝了一個攝像頭。T. Okad等14-16開發(fā)了平板式管道檢測機(jī)器人。然而，他們的設(shè)計是復(fù)雜的，并用于大型管道。針對這些因素，我們提出了一種雙動力輪鏈的管道檢測機(jī)構(gòu)。兩個輪鏈以180度的角度分開布置，所以可以在機(jī)器人身體的兩側(cè)附加傳感器。各輪采用兩臺電機(jī)控制;一種用于駕駛，另一種用于駕駛。一組計數(shù)車輪創(chuàng)建一個螺旋運(yùn)動，以實現(xiàn)轉(zhuǎn)向，另一組車輪創(chuàng)建一個直線運(yùn)動在管道內(nèi)，沒有任何奇異的運(yùn)動彎頭或t型分支。該機(jī)器人系統(tǒng)由3種控制模式組成;移動、探測和搜索。我們將為每種模式引入相應(yīng)的策略。機(jī)器人機(jī)構(gòu)采用并聯(lián)機(jī)構(gòu)設(shè)計，使其具有可折疊特性?？烧郫B的特性允許適應(yīng)的車輪機(jī)制，以墻壁內(nèi)的管道。第二部分介紹了機(jī)器人系統(tǒng)的特點。運(yùn)動學(xué)分析在第三節(jié)中介紹。第四部分通過仿真和實驗驗證了該機(jī)器人系統(tǒng)的有效性，最后給出了結(jié)論.II.機(jī)器人的特點A.整個系統(tǒng)和機(jī)器人設(shè)備圖一機(jī)器人系統(tǒng)由控制箱和機(jī)器人裝置組成。該機(jī)器人系統(tǒng)由一個操縱桿界面控制。機(jī)器人用戶可以利用視覺信息對管道的狀態(tài)進(jìn)行檢測。該機(jī)器人裝置由一個主體和兩個輪鏈組成，如圖2所示，機(jī)器人長度80mm，外徑100mm。 圖1帶兩輪鏈機(jī)制的管道檢測機(jī)器人系統(tǒng)該機(jī)器人機(jī)構(gòu)可以在三種不同的模式下工作;驅(qū)動模式、檢測模式、搜索模式。在驅(qū)動模式下，機(jī)器人處于運(yùn)動狀態(tài)。在檢測模式下，機(jī)器人檢測管道內(nèi)壁的狀態(tài)。在搜索模式下，機(jī)器人收圖2管道檢測機(jī)器人系統(tǒng)的整個結(jié)構(gòu)具有兩個輪鏈機(jī)制：（a） 3D 模型， （b開發(fā)的機(jī)器人。B.主體和側(cè)傳感器安裝器圖三顯示主體由按鍵滑塊、兩個主體軸、四個壓縮彈簧、傳感器貼片、前攝像頭和兩個側(cè)傳感器組成。關(guān)鍵滑塊(移動關(guān)節(jié))在主體軸上滑動，并連接到輪鏈的連桿上。壓縮彈簧能適應(yīng)鏈輪外徑的變化。這種設(shè)計允許機(jī)器人身體的可折疊特性。每個按鍵滑塊由按鍵連接器連接，這樣兩個輪子就能產(chǎn)生相同的折疊運(yùn)動。因此，如果我們使用這種設(shè)計，主體總是位于管道的中心。在該機(jī)構(gòu)中，機(jī)器人采用兩鏈的平面形狀。因此，在機(jī)器人身體的左右兩側(cè)都有一些空間，可以安裝各種傳感器，如MT, UT，或視覺傳感器(攝像機(jī))。在本文中，我們使用前置攝像頭、右攝像頭和圖 3 中顯示的左攝像頭。從每個攝像機(jī)中，我們可以獲取圖 4 中顯示的管道內(nèi)部信圖3主體結(jié)構(gòu)圖4相機(jī)視圖 - 前置攝像頭、左攝像頭和右攝像頭C.車輪鏈機(jī)制所述主體與所述輪鏈的折疊機(jī)構(gòu)相連。輪鏈由折疊機(jī)構(gòu)(并聯(lián)機(jī)構(gòu))、驅(qū)動電機(jī)(10)、主動輪、轉(zhuǎn)向輪(怠速輪)、轉(zhuǎn)向電機(jī)(8)和轉(zhuǎn)向機(jī)構(gòu)組成，如圖2和圖5所示。車輪驅(qū)動電機(jī)通過斜齒輪動力傳動帶動主動輪。如圖5的前視圖所示，轉(zhuǎn)向電機(jī)改變方向盤的方向，從而將機(jī)器人轉(zhuǎn)向想要的方向。III.機(jī)器人運(yùn)動規(guī)劃與檢測功能A. 管道的基本運(yùn)動圖6直管線的運(yùn)動（a）、 前視圖（b） 等軸測量視圖 （c）頂部視圖管道檢測機(jī)器人系統(tǒng)需要通過直線和曲線管道。要做到這一點，我們需要開發(fā)新的運(yùn)動規(guī)劃算法。圖6(a)中的xyz表示連接到管道檢測機(jī)器人本體的局部坐標(biāo)系。我們定義oi為方向盤的轉(zhuǎn)向角度。在沒有轉(zhuǎn)向角度的情況下，機(jī)器人在管道內(nèi)不作任何旋轉(zhuǎn)，沿z軸前后移動。當(dāng)機(jī)器人操作員使用前置攝像頭檢查管道狀態(tài)時，機(jī)器人的前后移動用于驅(qū)動模式。圖7顯示機(jī)器人的旋轉(zhuǎn)運(yùn)動。如果兩個方向盤被安排在相反的方向，如圖7（a），機(jī)器人明智地旋轉(zhuǎn)時鐘，并創(chuàng)建一個螺絲釘。圖7為機(jī)器人的旋轉(zhuǎn)運(yùn)動。如圖7(a)所示，如果車輪排列在相反的方向，機(jī)器人會明智地旋轉(zhuǎn)計數(shù)器時鐘。這種螺絲運(yùn)動可用于檢測模式：一旦前置攝像頭檢測到管道內(nèi)表面的某些缺陷，機(jī)器人就會使用螺絲運(yùn)動定位側(cè)攝像頭的位置，以便側(cè)攝像頭能夠清楚地檢查現(xiàn)場。通過控制方向盤在同一方向上的角度，也可以實現(xiàn)肘部或T-分支的轉(zhuǎn)向運(yùn)動。圖 8（a） 顯示，當(dāng)兩個方向盤轉(zhuǎn)向左方向時，機(jī)器人在 T 分支處向左轉(zhuǎn)。圖 8 （b） 用于轉(zhuǎn)向正確的方向。需要注意的是，即使在轉(zhuǎn)向運(yùn)動中，兩個驅(qū)動電機(jī)的速度也是一樣的。因此，與三個電動車輪機(jī)器人相比，轉(zhuǎn)向的控制力要小一些，三個車輪具有 差速，可通過肘部或 T 分支。 (a) (b)圖8T 分支和肘部的運(yùn)動 （a） 左轉(zhuǎn)運(yùn)動 （b） 右轉(zhuǎn)運(yùn)動。B.控制模式被調(diào)查管道檢測機(jī)器人具有控制模式;驅(qū)動模式、檢測模式、搜索模式。首先，在驅(qū)動模式下，機(jī)器人通過前置攝像頭前后移動來檢測管道的狀態(tài)。在檢測模式下，利用正面和側(cè)面的攝像頭對墻上的特殊點進(jìn)行精確定位。在搜索模式下，通過使用側(cè)攝像頭來識別光點的狀態(tài)或問題。圖9為三種模式的圖片。 圖9實驗結(jié)果： 管道內(nèi)導(dǎo)航IV、機(jī)制分析車輪機(jī)構(gòu)的詳細(xì)結(jié)構(gòu)、坐標(biāo)系、關(guān)節(jié)變量及參數(shù)如圖10所示。xyz表示連接到管道的本地坐標(biāo)框架。圖10折疊機(jī)制V、實施A. 控制器機(jī)器人控制器由控制盒、控制PC、抓取板、操縱桿界面和機(jī)器人設(shè)備組成，如圖12所示。機(jī)器人的控制是通過串行通信來執(zhí)行的。本系統(tǒng)采用單片機(jī)(Atmega128)。單片機(jī)通過產(chǎn)生PWM信號來計算電機(jī)轉(zhuǎn)速。它可以控制所有的微型直流電機(jī)。所有的電機(jī)驅(qū)動器和MCU集成在控制箱內(nèi)。管道的視圖通過安裝在機(jī)器人身體前面的微型CMOS攝像頭提供給用戶。這個攝像模塊可以檢查管道內(nèi)部的情況。裝有攝像頭的機(jī)器人裝置如圖12所示。 B. 機(jī)器人設(shè)備電機(jī)嵌入在車輪機(jī)構(gòu)的電機(jī)箱中。轉(zhuǎn)向馬達(dá)的峰值扭矩為 30mNm。選擇 Maxon re 8 和 GP 8B 齒輪頭用于轉(zhuǎn)向電機(jī)。驅(qū)動電機(jī)的峰值扭矩為150 毫安米。選擇 Maxon re 10 和 GP 10A 齒輪頭用于駕駛電機(jī)。表一 顯示了機(jī)器人的規(guī)格。機(jī)器人模塊的長度為80mm，機(jī)器人本體的外徑從80mm到100mm不等。包括攝像機(jī)和照明裝置在內(nèi)的機(jī)器人裝置總長度為94mm。機(jī)器人的重量是237克。本文采用直徑為100 mm的管道作為試驗平臺。C. 攝像機(jī)傳感器本文采用了三種CMOS攝像機(jī)傳感器。其直徑為10mm，最小焦距為2cm，可用于直徑小于100mm的管道中。VI.實驗結(jié)果實驗中采用了一種由直管、t型管和彎頭組成的管道。它的內(nèi)徑是100毫米。t形支管和彎頭均為商用產(chǎn)品。圖13試驗臺圖13為實驗的試驗臺，圖14為彎頭處的驅(qū)動和轉(zhuǎn)向運(yùn)動。從圖15、圖16可以看出，管道檢測機(jī)器人能夠在t支路上進(jìn)行轉(zhuǎn)向，并通過向后運(yùn)動和轉(zhuǎn)向運(yùn)動相結(jié)合成功改變方向。通過實驗驗證了該機(jī)器人系統(tǒng)的性能。附件中的視頻片段顯示了實驗結(jié)果。圖14肘部的運(yùn)動規(guī)劃：（a）=（b） 直管線向前運(yùn)動，（c） 車輪轉(zhuǎn)向，（d）（f）肘部向左方向轉(zhuǎn)動VII.結(jié)論針對80-10mm管道的檢測，我們開發(fā)了一種新型的多傳感器管道檢測機(jī)器人。該機(jī)器人裝置由兩個平面形狀的鏈輪組成。只需使用一個機(jī)器人模塊即可產(chǎn)生轉(zhuǎn)向和運(yùn)動運(yùn)動，無需任何奇異運(yùn)動。這個機(jī)器人的平板形狀允許在機(jī)器人的兩側(cè)安裝額外的傳感器。通過在試驗臺環(huán)境下的各種實驗，驗證了所提出的管道檢測機(jī)器人系統(tǒng)的性能。VIII.確認(rèn)這項工作是部分支持的中期研究項目通過NRF贈款資助的最高明的(2010 - 0000247),部分支持GRRC京畿道計劃(2010 - a02 GRRC漢陽),部分支持的知識經(jīng)濟(jì)部(MKE)和韓國發(fā)展研究所技術(shù)(吉)在戰(zhàn)略技術(shù),通過員工發(fā)展計劃和部分支持的人力資源開發(fā)韓國能源技術(shù)研究所韓國知識經(jīng)濟(jì)部評估與規(guī)劃(KETEP)資助項目。參考文獻(xiàn)1H.T.Roman, B. A. Pellegrino, and W. R. Sigrist, “Pipe crawling inspection robots: An overview,” IEEE Trans. Energy Convers., vol. 8, pp. 576583, Sept, 1993.2W. Neubauer, “A spider-like robot that climbs vertically in ducts or pipes,” in Proc. IEEE/RSJ Int. Conf. Intell. Robots Syst., 1994, pp. 11781185.3S. Hirose, H. Ohno, T. Mitsui, and K. Suyama, “Design of in-pipe inspection vehicles for _25, _50, _150 pipes,” in Proc. IEEE Int. Conf. Robot. Autom., 1999, pp. 23092314.4J. Okamoto, Jr., J. C. Adamowski, M. S. G. Tsuzuki, F. Buiochi, and C.S. Camerini, “Autonomous system for oil pipelines inspection,” Mechatronics, vol. 9, pp. 731743, 1999.5M. M. Moghaddam and A. Hadi, “Control and guidance of a pipe inspection-PIC,” in Proc. Int. Symp. Automations, Robotics, 2005, pp. 1114.6T. Aoki and S. Hirose, “Study on the brake operation of bridle bellows,” in Proc. IEEE/RSJ Int. Conf. Intell. Robots Syst., 2007, pp. 40-45.7P. Li, S. Ma, B. Li, and Y. 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Okada, “Development of a steerable, wheel-type, in-pipe robot and its path planning,” Advanced Robotics, Vol. 19, No. 6, pp. 635-650, 2005A Flat Pipeline Inspection Robot with Two Wheel ChainsABSTRACTThis paper presents a new pipeline inspection robot that has multiple sensors for inspection of 80-100mm pipelines. The special feature of this robot is realization of driving and steering capability by using only two wheel chains. Compared to popularly employed pipeline robots using three wheel chains, the new design allows simple robot control and easy user interface, specially at T-branch. As another advantage, the flat shape of this robot allows mounting additional sensors on the both sides of the robot. The kinematics and three control modes are described. Finally, the performance of this robot system is verified by experimentation.Keywords：Pipeline robo；system；kinematicsI.INTRODUCTIONThe functions of pipeline inspection robots can be described as driving, steering, detecting, and retrieving.However, robots used for inspection of pipelines with its diameter of less than 100mm has a special difficulty in designing compact steering mechanism and mounting sensors such as magnetic probe and ultra-sonic probe to inspect crack, rupture, leaking, etc.In-pipe robot mechanism, which has a long history of development in robotics, can be classified into several elementary forms according to the movement patterns. They are wheel -type, inchworm-type, legged mobile-type, screw-type, crawler-type, PIG-type, and passive -type. Among them, wheel-type pipeline inspection robots have been mostly popular 1-8. However, they are not appropriate for operations in the vertical pathway or at T-branch. During the latest 10 years, differential-drive type mechanisms have been studied intensively 9-11. The differential-drive type usually has three powered wheel chains. Controlling the speed of each chain independently, the robot is able to go through elbows and T-branches. However, when using just one robot module, sometimes singular motion happens at T- branch9 . To resolve such a problem, several methods have been developed such as active steering joint mechanism 12-13 or collaboration of two robot modules9. However, the size of the whole robot system becomes bulky. Another disadvantage of using three powered wheel chains is not having enough space to mount more sensors in the robot body, because three wheel chains occupy most of cross-sectional area of the pipeline specially having diameter of less than 100mm. Currently, only one camera is installed in front of the robot body. T. Okada, et al14-16 developed flat type pipeline inspection robot. However, their design is complex and used for large sized pipelines.In light of these factors, we propose a pipeline inspection mechanism having two powered wheel chains. The two wheel chains are arranged with 180 degrees apart, so additional sensors can be attached on both sides of the robot body. Each wheel chain is controlled by using two motors ; one for driving and the other for steering. A set of count wheels creates a screw motion to realize steering and another set of wheels creates a linear motion inside the pipeline without having any singular motion at elbow or T-branch.The robot system consists of 3 control modes ; moving, detecting, and searching. We will introduce corresponding strategy for each mode. The robot mechanism is designed using a parallel linkage so that it can provide the foldable characteristic. The foldable characteristic allows adaptation of the wheel mechanism to the wall inside the pipeline. Section II introduces the characteristics of the robot system. The kinematic analysis is presented in section III. We show the validity of this robot system by both simulation and experimentation in section IV. Lastly, we draw conclusion.II.CHARACTERISTICS OF ROBOTA.The whole system and robot deviceThe robot system shown in the Fig. 1 consists of a control box and a robot device. The robot system is controlled by a joystick interface. The user of robot can check the state of pipeline by using vision information.The robot device consists of a main body and two wheel chains, as shown in Fig. 2. The length of robot is 80mm and the exterior diameter is 100mm.Fig. 1. The pipeline inspection robot system with two wheel chain mechanism.This robot mechanism can be operated in three different modes; driving mode, detecting mode, and searching mode. In the driving mode, the robot is in motion. In the detecting mode, the robot detects the state of the inner wall of the pipeline. In the searching mode, the robot collects the detail information.（a） （b）Fig. 2. The whole structure of the pipeline inspection robot system with two wheel chain mechanism: (a) The 3D model, (b) The developed robot.B.The main body and side sensor mounterFig. 3 shows that the main body consists of a key slider, two main body axes, four compression springs, a sensor mounter, a front camera, and two side sensors. The key slider(prismatic joint) slides on the main body axis and it is connected to the linkage of the wheel chain. The compression spring adapts to change of the outer diameter of the wheel chain. This design allows a foldable characteristic of the robot body. Each key slider is connected by a key connector so that two wheels generate the same folding motion. Thus, the main body is always located at the center of the pipeline if we use this design.In this mechanism, the robot has a flat shape by using two chains. Thus, there are some spaces on left and right sides of the robot body, where various sensors like MT, UT, or vision sensor (camera) can be mounted. In this paper, we use a front camera, the right camera, and the left camera as shown in the Fig.3. From each camera, we can get the internal information of the pipeline as shown in Fig. 4.Fig. 3. The structure of the main bodyFig. 4. The camera view - front camera, left camera, and right cameraC.The wheel chain mechanismThe main body is connected to the folding mechanism of the wheel chain. The wheel chain consists of a folding mechanism (parallel linkage), a driving motor (10 ), an active wheel, a steering wheel (idle wheel), a steering motor (8 ), and a steering mechanism as shown in Fig. 2 and Fig. 5.The wheel drive motor drives the active wheel through a helical gear power transmission. As shown in the front view of Fig. 5, the steering motor changes the direction of the steering wheel so that the robot can be steered to a desired direction. Fig. 5. The structure of the wheel chainIII.ROBOT MOTION PLANNING AND DETECTING FUNCTIONThe pipeline inspection robot system is required to pass through straight and curved pipelines. To do this, we need to develop new motion planning algorithms. A.The basic movement at the pipelineFig. 6. The motion at the straight pipeline (a) the front view (b) the isometric view (c) the top viewxyz in Fig. 6(a) represents the local coordinate frameattached to the body of the pipeline inspection robot. We define oi as the steering angle of the steering wheel. If there is no steering angle, the robot moves forward and backward along the z -axis without any rotation in the pipeline. The forward and backward movements of the robot are used in the driving mode when the robot operator checks the state of pipelines by using the front camera.Fig. 7 shows the rotational motion of the robot. If the two steering wheels are arranged in an opposite direction such as Fig. 7(a), the robot rotates clock wisely and creates a screw.If the wheels are arranged in an opposite direction, the robot rotates counter clock wisely. Such screw motion can be used in the detection mode; Once the front camera detects some flaws on the inner surface of the pipeline, the robot uses the screw motion and locate the position of the side camera such that the side camera is able to inspect the spot clearly.Steering motion at elbows or T- branches can be also achieved by controlling the angles of the steering wheels in the same direction. Fig. 8(a) shows that the robot turns to the left at the T-branch, when the two steering wheels are steered to the left direction. Fig. 8(b) is for steering to the right direction. It should be noted that the speeds of the two driving motors are the same even in the steering motion. Thus, control effort for steering is less as compared to three powered wheel robot in which three wheels have differential wheel speed to pass through elbows or T-branches. Fig. 8. The motion at the T-branch and elbow (a)Left turning motion (b)Right turning motion.B.The control modesThe pipeline inspection robot under investigation has control modes; driving mode, detecting mode, and searching mode. First of all, in the driving mode the robot moves forward or backward to inspect the state of the pipeline by using the front camera. In the detecting mode, the position of the special spot on the wall is exactly located by using both the front and side cameras. In the searching mode, the state or problem of the spot is identified by using the side camera. Fig. 9 shows the pictures of the three modes.Fig. 9. The experimental result : navigation inside the pipelineIV. ANALYSIS OF MECHANISMThe detailed structure, coordinate system, joint variables, and parameters of the wheel mechanism are given in Fig. 10. xyz denotes a local coordinate frame attached to the pipeline.Fig. 10. Folding mechanismVIMPLEMENTATIONA. ControllerThe robot controller consists of a control box, a control PC, a grabber board, a joystick interface, and a robot device as shown in the Fig. 12. The robot control is executed by a serial communication. In this system, we use MCUs (Atmega128). The MCU calculates the motor speed by producing a PWM signal. It can control all of the Micro DC motors. All the motor drives and MCU are integrated in the control box.The view of the pipeline is provided to the user by using a Micro CMOS camera mounted in front of the robot body. This camera module makes it possible to inspect the condition inside the pipeline. The robot device equipped with a camera is shown in Fig. 12.Fig. 12. The robot controller.B.The robot deviceThe motors are embedded in the motor box of the wheel mechanism. The peak torque of steering motor is 30 mNm. The Maxon re 8 and GP 8B gear head are chosen for steering motor. The peak torque of the driving motor is 150 mNm. The Maxon re 10 and GP 10A gear head are chosen for the driving motor.Table I shows the specification of the robot. The length of the robot module is 80mm and the exterior diameter of the robot body changes from80mm up to 100mm. The total length of the robot device including the camera and the lighting device is 94mm. And the weight of the robot is 237g. In this paper, a pipeline with diameter of 100 mm is employed as a test bed.C.The cameraIn this paper, three CMOS camera sensors were used. Its diameter is 10mm, and its minimum focal length is 2cm such that it can be used in the pipeline with diameter of less than100mm. Table II shows the specification of the camera. TABLE ISPECIFICATION OF THE ROBOTSpecificationTbot-100-2chnWeight of the robot module237gMotor diameter6mmLength of the robot module80mmTotal length of the robot including camera)94mmExterior diameter 80-100mmLinear speed 14cm/secSerial communication distance15 M VI. EXPERIMENTAL RESULTSA pipeline consisting of a straight part, a T-branch, and an elbow was employed in experiment. Its interior diameter is 100mm. The T-branch and elbow are commercial products.Fig. 13. The test bed.Fig. 13 shows the test bed for the experimentation and Fig. 14 shows the driving and steering motions at elbow. Fig. 15, 16 demonstrates that the pipeline inspection robot is able to steer at the T-branch and can also change the direction successfully by combining the backward and steering motions. Thus, the performance of the proposed robot system could be verified through this experimentation. The attached video clip shows the experimental result.Fig. 14. Motion planning at the elbow : (a)(b) forward motion at straight pipeline, (c) wheel steering, (d)(f) turning to the left direction at elbowVII. CONCLUSIONSWe developed a new pipeline inspection robot that has multiple sensors for inspection of 80-10mm pipelines. The robot device consists of two wheel chains which has a flat shape. The steering and moving motion can be generated by using just one robot module without having any singular motion. The plat shape of this robot allows mounting additional sensors on the both sides of the robot. The performance of the proposed pipeline inspection robot system was verified through a variety of experiment under a test-bed environment.ACKNOWLEDGEMENTThis work was partially supported by Mid-career Researcher Program through NRF grant funded by the MEST (No. 2010-0000247),partially supported by GRRC program of Gyeonggi Province (GRRC HANYANG 2010