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編號(hào)
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
相關(guān)資料
題目： 60噸焊接變位機(jī)設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化專業(yè)
學(xué) 號(hào)： 0923237
學(xué)生姓名： 朱 斌
指導(dǎo)教師： 尤麗華 （職稱：副教授 ）
（職稱： ）
2013年5月25日
目 錄
一、畢業(yè)設(shè)計(jì)（論文）開(kāi)題報(bào)告
二、畢業(yè)設(shè)計(jì)（論文）外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文（論文）計(jì)劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無(wú)錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
開(kāi)題報(bào)告
題目： 60噸焊接變位機(jī)設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動(dòng)化 專業(yè)
學(xué) 號(hào)： 0923237
學(xué)生姓名： 朱 斌
指導(dǎo)教師： 尤麗華 （職稱：教授 ）
（職稱： ）
2012年11月25日
課題來(lái)源
本課題來(lái)自無(wú)錫華聯(lián)精工機(jī)械有限公司的生產(chǎn)實(shí)際。目前機(jī)械行業(yè)，特別是鍋爐行業(yè)有大量的管和板的焊接，管子和板的接合處為環(huán)縫焊接，為適應(yīng)自動(dòng)焊接，管與板要自轉(zhuǎn)，同時(shí)要傾斜45度，滿足船形焊接，要求設(shè)計(jì)該設(shè)備。
科學(xué)依據(jù)（包括課題的科學(xué)意義；國(guó)內(nèi)外研究概況、水平和發(fā)展趨勢(shì)；應(yīng)用前景等）
在焊接過(guò)程中，我們經(jīng)常會(huì)遇到焊接變位以及選擇合適的焊接位置的情況，為了解決這一問(wèn)題，焊接變位機(jī)就理所應(yīng)當(dāng)?shù)某霈F(xiàn)。它可以通過(guò)工作臺(tái)的回轉(zhuǎn)和翻轉(zhuǎn)，使待焊處置于合適位置，很好的和焊接設(shè)備結(jié)合使用，實(shí)現(xiàn)焊接的自動(dòng)化，機(jī)械化，提高生產(chǎn)效率和焊接質(zhì)量。概括來(lái)講，焊接變位機(jī)就是移動(dòng)工件，使之待焊部位處于合適的位置的焊接輔助設(shè)備?，F(xiàn)在我國(guó)生產(chǎn)變焊接的廠家已經(jīng)不少，但都不成規(guī)模。以變位機(jī)為主導(dǎo)產(chǎn)品發(fā)展起來(lái)的企業(yè)，尚未形成。天津鼎盛公司工程機(jī)械有限公司、無(wú)錫市陽(yáng)通機(jī)械設(shè)備有限公司、長(zhǎng)沙海普公司、威達(dá)自動(dòng)化設(shè)備有限公司等單位生產(chǎn)的變位機(jī)在國(guó)內(nèi)占有較大市場(chǎng)。到2010年，國(guó)內(nèi)已開(kāi)發(fā)的變位機(jī)產(chǎn)品約130余種規(guī)格。然而在國(guó)際上，包括各種功能的產(chǎn)品在內(nèi)，有百余種系列。在技術(shù)上有普通型的，有無(wú)隙傳動(dòng)伺服控制型的；產(chǎn)品的額定負(fù)荷范圍達(dá)到0.1KN～18000KN。
在先進(jìn)工業(yè)國(guó)家，焊接變位機(jī)已標(biāo)準(zhǔn)化、系列化，并由專門廠家生產(chǎn)，技術(shù)指標(biāo)先進(jìn)，品種規(guī)格齊全，不僅有各種結(jié)構(gòu)形式的通用焊接變位機(jī)，也有配合焊接機(jī)器人使用的高精度變位機(jī)。比較有名的國(guó)外公司有：瑞典的ESAB、意大利的ANSALDO、德國(guó)的CL00S、奧地利的IGM、美國(guó)的LINCOLN和日本的 機(jī)械株式會(huì)社 。他們的產(chǎn)品，我國(guó)都有引進(jìn)，其中以引進(jìn)ESAB公司的較多，蘭州石油化工機(jī)器廠在1991年就引進(jìn)了該公司生產(chǎn)的30t焊接變位機(jī)；四川東方鍋爐廠為了核電站反應(yīng)容器的生產(chǎn)，1997年也從該公司引進(jìn)了100t的焊接變位機(jī)，長(zhǎng)春焊機(jī)廠還從日本引進(jìn)了生產(chǎn)焊接變位機(jī)的技術(shù)。配合焊接機(jī)器人使用的焊接變位機(jī)，在我國(guó)幾乎都是作為焊接柔性加工單元(FMC)和柔性加工系統(tǒng)(FMS)的組成部分一并引進(jìn)的。據(jù)1995年的不完全統(tǒng)計(jì)，已引進(jìn)約200多臺(tái)，主要用于汽車、工程機(jī)械等有關(guān)結(jié)構(gòu)的焊接。
我國(guó)引進(jìn)的焊機(jī)器人柔性加工單元中的變位機(jī)，也是針對(duì)特定產(chǎn)品研制的，因此價(jià)格較昂貴，而技術(shù)培訓(xùn)及售后服務(wù)卻不理想。在技術(shù)方面，我國(guó)許多工廠引進(jìn)的弧焊機(jī)器人系統(tǒng)己具有機(jī)器人與變位機(jī)協(xié)調(diào)運(yùn)動(dòng)的功能。這對(duì)一些空間曲線或較復(fù)雜的焊縫可以始終保持在最佳位置下進(jìn)行焊接，以提高焊接質(zhì)量，并能一次起弧就焊完整條焊縫，以提高效率。但是有關(guān)技術(shù)卻往往為外方廠家所壟斷，我們并不掌握。從提高我國(guó)焊接生產(chǎn)機(jī)械化與自動(dòng)化水平的角度出發(fā)，必須加大科研投入，研制高性能的焊接機(jī)器人與配套變位設(shè)備，力求在自動(dòng)化焊接領(lǐng)域在國(guó)際上占有一席之地。
研究?jī)?nèi)容
本焊接變位機(jī)由工作平臺(tái)、回轉(zhuǎn)機(jī)構(gòu)、翻轉(zhuǎn)機(jī)構(gòu)、機(jī)座、控制裝置和焊接導(dǎo)電裝置組成。
㈠工作臺(tái)
它用于工件的停放和固定。在臺(tái)面上開(kāi)溝槽，表面經(jīng)網(wǎng)絡(luò)狀處理后增大了摩擦，一方面配合夾具固定工件，一方面也增大了表面的摩擦。
⑴工作盤為直徑Φ3000的圓盤
⑵用優(yōu)質(zhì)鋼板焊接而成，在受力部位作了加強(qiáng)處理；退火處理，消除應(yīng)力后加工。
⑶工作盤固定在專業(yè)回轉(zhuǎn)體上，保證穩(wěn)定地承載和回轉(zhuǎn)。
㈡回轉(zhuǎn)機(jī)構(gòu)
⑴工作臺(tái)固定在大型回轉(zhuǎn)支承上，保證額定載荷下的承載及回轉(zhuǎn)平衡；回轉(zhuǎn)機(jī)構(gòu)用于帶動(dòng)工件旋轉(zhuǎn)，便于焊頭對(duì)工件進(jìn)行環(huán)形焊接。
⑵工作臺(tái)底部采用型材焊接成形，在受力部位作加強(qiáng)處理，工作臺(tái)焊后進(jìn)行去應(yīng)力處理，變形小。
⑶工作臺(tái)固定在回轉(zhuǎn)支承上，從而保證穩(wěn)定回轉(zhuǎn)。采用回轉(zhuǎn)支承承載，固有承載能力大，回轉(zhuǎn)精度高的特點(diǎn)。
⑷轉(zhuǎn)支承采用“單排四點(diǎn)接觸球式回轉(zhuǎn)支承”（型號(hào)為012. 60. 2000 . ）由專業(yè)廠家生產(chǎn)。具有結(jié)構(gòu)合理、剛性好、自重輕、壽命長(zhǎng)等優(yōu)點(diǎn)。
⑸工作臺(tái)的回轉(zhuǎn)由交流電機(jī)通過(guò)雙級(jí)擺線針輪減速器驅(qū)動(dòng)，減速器輸出小齒輪與回轉(zhuǎn)嚙合，從而驅(qū)動(dòng)工作臺(tái)回轉(zhuǎn)。
⑹驅(qū)動(dòng)小齒輪采用40Cr材質(zhì)，并經(jīng)調(diào)質(zhì)，齒面淬火處理，從而滿足高強(qiáng)度的傳遞使用。
⑺驅(qū)動(dòng)采用交流變頻無(wú)極調(diào)速，范圍廣，以保證在較寬調(diào)速范圍內(nèi)的恒扭矩輸出。
⑻整個(gè)回轉(zhuǎn)機(jī)構(gòu)安裝在箱型結(jié)構(gòu)的橫梁翻轉(zhuǎn)框上，橫梁對(duì)工件進(jìn)行支撐承載，并將工件的重量通過(guò)橫梁傳遞到兩邊立柱支架上，能承受大的沖擊載荷和扭曲力。采用箱型機(jī)構(gòu)可以有效承載和抗扭能力。
㈢翻轉(zhuǎn)機(jī)構(gòu)
㈠翻轉(zhuǎn)機(jī)構(gòu)可使工件產(chǎn)生俯仰運(yùn)動(dòng)，改變工件的位置便于焊接；
⑵采用圓弧硬齒面蝸輪蝸桿減速器具有承載能力大，看沖擊能力強(qiáng)的特點(diǎn)，但成本是普通蝸輪蝸桿減速器的2-3倍。
⑶翻轉(zhuǎn)工作原理：電磁制動(dòng)電機(jī)-減速器-齒輪-大齒盤-工件，由大直徑和大模數(shù)的雙齒盤才實(shí)現(xiàn)工件的翻轉(zhuǎn)，平穩(wěn)可靠、承載效果好。
⑷翻轉(zhuǎn)驅(qū)動(dòng)裝置的小齒輪與傘齒嚙合，驅(qū)動(dòng)機(jī)構(gòu)翻轉(zhuǎn)；
㈣底座
⑴機(jī)架采用型材焊接而成結(jié)構(gòu)牢固可靠，是整個(gè)設(shè)備的支撐結(jié)構(gòu)
⑵為了保證強(qiáng)度，我們將底座聯(lián)接為整體，內(nèi)部行腔根據(jù)受力的情況焊接加強(qiáng)筋；
⑶底座的延伸支架腿長(zhǎng)度應(yīng)該達(dá)到超過(guò)其最大重心距的要求
㈤工作機(jī)需要電動(dòng)機(jī)輸入功率才能工作
一般原動(dòng)機(jī)與工作機(jī)不直接相連，而是通過(guò)在兩者之間設(shè)置一個(gè)中間裝置，稱這個(gè)中間裝置為傳動(dòng)裝置簡(jiǎn)稱傳動(dòng)；在機(jī)械中，傳動(dòng)裝置的功用是根據(jù)工作機(jī)的工作提要實(shí)現(xiàn)某種減速、增速、變速、或改變運(yùn)動(dòng)形式的功能。工程實(shí)踐表明，傳動(dòng)裝置是機(jī)械中重要的組成部分，在整機(jī)的成本和重量中占有很大的比重，并在很大程度上決定整機(jī)的技術(shù)性能和運(yùn)轉(zhuǎn)費(fèi)用。因此，正確設(shè)計(jì)傳動(dòng)裝置對(duì)保證整機(jī)的技術(shù)性能和質(zhì)量指標(biāo)都具有相當(dāng)重要的意義。根據(jù)工作原理的不同，傳動(dòng)分為兩類：機(jī)械傳動(dòng)和電傳動(dòng)。
㈥選擇傳動(dòng)形式時(shí)，應(yīng)當(dāng)考慮的主要指標(biāo)
功率、效率、運(yùn)動(dòng)性能、外形尺寸、重量、生產(chǎn)率和成本等?，F(xiàn)分別闡述如下：
⑴功率
每種傳動(dòng)所傳遞的功率大小與該傳動(dòng)的工作原理、承載能力 、工作速度、效率 、材料和制造精度等因素有關(guān)。一般來(lái)說(shuō)，嚙合傳動(dòng)傳遞的功率高于摩擦傳動(dòng)傳遞的功率，但是嚙合傳動(dòng)中蝸桿傳動(dòng)則因材料關(guān)系也不能傳遞大的功率。
⑵效率
效率是評(píng)定傳動(dòng)質(zhì)量指標(biāo)的一個(gè)重要參數(shù)。高的效率意味著節(jié)約動(dòng)力。傳動(dòng)效率低，一般不宜傳遞大的功率。通常嚙合傳動(dòng)的效率高于摩擦傳動(dòng)，但普通圓柱蝸桿的傳動(dòng)可能低于摩擦傳動(dòng)。
⑶速度
速度是傳動(dòng)裝置的一個(gè)主要運(yùn)動(dòng)特性。提高傳動(dòng)的速度是機(jī)械的主要發(fā)展方向之一。影響速度的因素有動(dòng)載荷和制造精度等。
⑷傳動(dòng)比
傳動(dòng)比是傳動(dòng)裝置的又一種運(yùn)動(dòng)特性。每種傳動(dòng)因受外形尺寸或承載能力的影響限制，均有各自適用的最大傳動(dòng)比值。此外，還應(yīng)考慮傳動(dòng)比值的準(zhǔn)確性問(wèn)題。對(duì)于要求精確傳動(dòng)比的機(jī)械，不用摩擦傳動(dòng)而采用嚙合傳動(dòng)。
⑸外廓尺寸、重量及成本
傳動(dòng)裝置的外廓尺寸和重量與傳動(dòng)零件材料的機(jī)械性和容許傳遞速度、容許傳遞功率密切相關(guān)。在上述條件確定下，單極傳動(dòng)的外廓尺寸和重量主要取決于傳動(dòng)形式。一般來(lái)說(shuō)嚙合傳動(dòng)比摩擦傳動(dòng)輕巧，但成本高。嚙合傳動(dòng)中，蝸桿程度和一些內(nèi)嚙合行星傳動(dòng)的尺寸和重量通常小。
⑹機(jī)構(gòu)預(yù)期壽命
機(jī)構(gòu)預(yù)期使用壽命為10年，每天兩班制，全年工作300個(gè)工作日記則其使用壽命為10*300*2*8=4800小時(shí)。
總之，綜合考慮各種情況，得出一個(gè)最優(yōu)設(shè)計(jì)方案，設(shè)計(jì)一個(gè)符合實(shí)際情況的焊接變位機(jī)。
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
通過(guò)對(duì)輸煤系統(tǒng)的實(shí)地考察，總結(jié)得出輸60噸焊接變位機(jī)的基本結(jié)構(gòu)，工作方式與原理。然后根據(jù)考察的結(jié)果，再查閱相關(guān)書(shū)籍，確定基本的設(shè)計(jì)參數(shù)，進(jìn)行初步的三維建模。交由指導(dǎo)老師檢查，修改。完成后，再對(duì)主要載荷部件進(jìn)行校核。最后出主要零件的零件圖，編寫(xiě)設(shè)計(jì)說(shuō)明書(shū)。
可行性分析：《我國(guó)焊接輔助設(shè)備與器具制造行業(yè)前景分析》我國(guó)焊接工藝裝備制造行業(yè)起步較晚，直到二十世紀(jì)70年代初才在上海、成都、長(zhǎng)春等地陸續(xù)建成一批專門生產(chǎn)焊接工藝設(shè)備的制造廠。進(jìn)入80年代，隨著國(guó)內(nèi)焊接工藝裝備需用量的日益增長(zhǎng)，各地又相繼成立多家中小型焊接裝備生產(chǎn)廠。近期又新建成或改建具有一定規(guī)模的焊接裝備生產(chǎn)企業(yè)。迄今，我國(guó)已有24加焊接裝備生產(chǎn)企業(yè)，年產(chǎn)量2000萬(wàn)元以上的已有10多家。有些企業(yè)發(fā)展速度較快，并已具有較大的規(guī)模，有些焊接設(shè)備已實(shí)現(xiàn)批量生產(chǎn)。
研究計(jì)劃及預(yù)期成果
本焊接變位機(jī)由工作平臺(tái)、回轉(zhuǎn)機(jī)構(gòu)、翻轉(zhuǎn)機(jī)構(gòu)、機(jī)座、控制裝置和焊接導(dǎo)電裝置組成。此焊接變位機(jī)可解決鍋爐行業(yè)有大量的管和板的焊接，管子和板的焊接問(wèn)題，主要體現(xiàn)在下面幾個(gè)方面：
⑴穩(wěn)定和提高焊接質(zhì)量，保證其均一性
焊接參數(shù)如焊接電流、電壓、焊接速度等對(duì)焊接結(jié)果起決定行作用。采用焊接變位機(jī)焊接時(shí)對(duì)于每條焊接的焊縫的焊接參數(shù)都是恒定的，焊接質(zhì)量受人的因素影響較小，降低了工人操作技術(shù)的要求，因此焊接質(zhì)量是穩(wěn)定的。而人工焊接時(shí)，焊接速度、干伸長(zhǎng)等都是變化的，因此很難做到質(zhì)量的均一性。
⑵改善了工人的勞動(dòng)條件
采用焊接變位機(jī)焊接工人只是用來(lái)裝卸工件，遠(yuǎn)離了焊接弧光、煙霧和飛濺等，對(duì)于點(diǎn)焊來(lái)說(shuō)工人不再搬運(yùn)笨重的手工焊鉗，使工人從大強(qiáng)度的體力勞動(dòng)中解脫出來(lái)。
⑶提高勞動(dòng)生產(chǎn)率
焊接變位機(jī)沒(méi)有疲勞，一天可24小時(shí)連續(xù)生產(chǎn)，另外隨著高速高效焊接技術(shù)的應(yīng)用，使用焊接變位機(jī)焊接，效率提高的更加明顯。
今年來(lái)我國(guó)對(duì)于焊接技術(shù)有很大的提高，有效提高生產(chǎn)效率，減輕了工人的勞動(dòng)強(qiáng)度。焊接變位機(jī)件大量應(yīng)用于焊接生產(chǎn)中。
特色或創(chuàng)新之處
近年來(lái)我國(guó)焊接變位機(jī)行業(yè)占整個(gè)行業(yè)的40%以上，與焊接這個(gè)特殊的行業(yè)有關(guān)，焊接作為工業(yè)“裁縫”，是工業(yè)生產(chǎn)中非常重要的加工手段。
焊接變位機(jī)應(yīng)具有以下技術(shù)要求：①回轉(zhuǎn)驅(qū)動(dòng)實(shí)現(xiàn)無(wú)極調(diào)速，并可逆轉(zhuǎn)。②在回轉(zhuǎn)速度范圍內(nèi)，承受最大載荷時(shí)轉(zhuǎn)速波動(dòng)不超過(guò)5%。③傾斜驅(qū)動(dòng)應(yīng)平穩(wěn)，在最大負(fù)荷下不抖動(dòng)，整機(jī)不得傾覆。最大負(fù)荷Q超過(guò)25kg的，應(yīng)具有動(dòng)力驅(qū)動(dòng)功能。④應(yīng)設(shè)有限位裝置，控制傾斜角度，并有角度指示標(biāo)志。⑤傾斜機(jī)構(gòu)要具有自鎖功能，在最大負(fù)荷下不滑動(dòng)，安全可靠。⑥變位機(jī)控制部分應(yīng)設(shè)有供自動(dòng)焊接的聯(lián)動(dòng)接口。
我設(shè)計(jì)的焊接變位機(jī)也會(huì)按照以上要求設(shè)計(jì)，即注重實(shí)用性和安全性；同時(shí)性價(jià)比高，成本低。
已具備的條件和尚需解決的問(wèn)題
已具備的條件：設(shè)計(jì)過(guò)程中所需要的各種軟硬件資源和相關(guān)產(chǎn)品實(shí)物照片。
尚需解決的問(wèn)題：相關(guān)文獻(xiàn)資料的缺乏，對(duì)一些結(jié)構(gòu)設(shè)計(jì)部分的具體設(shè)計(jì)指導(dǎo)，以及三維軟件的高級(jí)運(yùn)用技巧。
指導(dǎo)教師意見(jiàn)
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教研室（學(xué)科組、研究所）意見(jiàn)
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Use of Voice Recognition for Control of a Robotic Welding Workcell
ABSTRACT: This paper describes work underway to evaluate the effectiveness of voice recognition systems as an element in the control of a robotic welding workcell. Factors being considered for control include program editor access security,Preoperation checklist requirements, welding process variable control,and robot manipulator motion overrides. In the latter two categories, manual vocal control is being compared against manual tactile control and fully automatic control in terms of speed of response, accuracy, stability, reliability. And safety.
Introduction
Voice recognition technology is now recognized as a potential means for easing the
workload of operators of complex systems. Numerous applications have already been implemented, are in various stages of development, or are under consideration. These include data entry,control of aircraft systems, and voice identification and verification for security purposes.
Voice control has also been proposed for use aboard the space station. One prime area for application would be control of some functions of robots used for intraand extravehicular inspection, assembly, repair,satellite retrieval, and satellite maintenance when a crewmember is serving in a supervisory capacity or the system is operating in a teleoperation mode. Voice control of sensors and process variables would free the crewmember’s hands for other tasks, such as direct control or override of the manipulator motion. Similarly, the workload associated with control of many onboard experiments could be eased through the use of this technology.
This paper describes the application of voice recognition for control of a robotic welding workcell. This is a complex system involving inputs from multiple sensors and control of a wide variety of robot manipulator motions and process variables. While many functions are automated, a human operator serves in a supervisory capacity, ready to override functions when necessary. In the present investigation, a commercially available voice recognition system is being integrated with a robotic welding workcell at NASA Marshall Space Flight Center, which is used as a test bed for evaluation and development of advanced technologies for use in fabrication of the Space Shuttle Main Engine. In the system under development, some functions do not yet have automatic closedloop control, thus requiring continuous monitoring and real-time adjustment by the human operator. Presently, these ovemdes are input to the system through tactile commands (;.e.. pushing buttons. turning knobs for potentiometers, or adjusting mechanical devices). Since the operator monitors the process primarily visually, he must either look away from the process to find the proper button or knob or rely on“muscular memory”much as a touch-typist does. In the first case, the time of response to a deviant condition may be excessive. In the second case, there is an increased probability of a secondary error being introduced by the operator.
A voice recognition system could reduce the response time required from the operator.The probability of pushing the wrong button should similarly be reduced. Also, operator fatigue should be minimized.
Since the operator can continuously monitor the process during override input, the effect of the change can be observed more quickly. Thus, if the desired value is exceeded and reverse correction is required, it should be accomplished more quickly, allowing less overshoot. This reduction in oscillation about the desired value makes the system more stable.
Another factor that can be improved is operator safety. In a safety-critical situation,the robot’s operation can be halted immediately by use of the “emergency stop,’’ or E-stop, mode, which is initiated, conventionally, by depressing a large button. If an operator inadvertently finds himself in a hazardous situation, it may be necessary for him to initiate the E-stop sequence. Should the operator not be within reach of the button,however, he may be unable to take the necessary action, and, as a result, could suffer serious injury. Having the capability of stopping the robot by issuing a voice command could significantly improve the operator’s safety by enabling him to stop the robot even when not within reach of the E-stop button.
Manual corrections are occasionally required to adjust the location at which the weld filler wire enters the weld pool. Proper entry location is absolutely critical to sound weld quality. Adjustments are made either by manually adjusting mechanisms that hold the wirefeed guide tube or by issuing tactile commands to a servomechanism. Use of a voice recognition system could eliminate the need for the operator to place his hand within the working envelope of the robot end effector or, if servomechanisms are employed,could improve speed of response and stability.
Another aspect of robot operation in an industrial environment that is very important is the security of a program editing capability of the system. Under no circumstances should any unauthorized person be able to enter this programming mode and alter the robot’s program. A voice recognition system can provide the necessary security by allowing access only for individuals who are authorized and whose voices can be identified by the system.
Background
Robotic welding is under development by NASA and Rocketdyne for the automation of welds on the Space Shuttle Main Engine that are presently made manually. The programmability of a robot can reduce the percentage of welding defects through a combination of consistency and repeatability unattainable by its human counterparts. To do this, the robot is programmed to a nominal weld path and level of weld process parameters (i.e., current, travel speed. voltage,wire addition rate). Some adjustment of these values is often necessary due to conditions changing during the weld. A human making a manual weld accomplishes this adjustment readily, while a robot must rely on the limited talents of sensors and the ability of the operator to override functions when necessary.
System Integration
The basic elements of the workcell system are shown diagrammatically in the illustration.The ultimate goal of the system development work in progress is to generate robot manipulator programs and weld process programs off line, download them to the workcell supervisory computer, then use sensor subsystems to make closed-loop corrections to the robot path and process variables. Offline programming is being done with an Intergraph modified VAX 780/785-205 computer system with Interact color graphics workstations. Deviations between the programmed robot path and the actual required path are observed and corrected by a sophisticated vision-based sensor developed for this application by Ohio State University.This sensor system is also designed to permit measurement of the molten weld pool surface dimensions and correct welding current level to maintain the weld pool dimensions within desired limits. Presently, a number of functions are still controlled manually, and manual overrides capability is required for all functions. As stated in the Introduction, use of voice recognition may improve the accuracy and speed of response of these manual overrides. To explore this technology, a Votan VRT 6050 stand-alone voice recognition terminal has been integrated into the workcell. This system provides continuous speech recognition of up to 10 sets of words with 75-150 words per set.
The integration of the voice recognition system is broken into analog and discrete signals for control. The voice recognition system connects to the control computer through a standard RS232-C communications link.
Discrete Control Signals
In this project, most of the control circuitry is based on discrete digital signals.This is due to the on/off state nature of the circuits to be controlled in the robot controller.The circuits of the system to be controlled by the voice recognition control computer (VRCC) by discrete signals are the emergency stop circuit and the positive jog and negative jog circuits for motion control.
Since the safety of the operator is paramount in any automated workcell, the voice recognition system should be incorporated as a safety feature. To accomplish this, the VRCC has been interfaced into the workcell emergency stop circuit. The emergency stop circuit in the robotic workcell will shut down the welding process and the mechanical motion of the manipulators. Through the use of a digital signal from the VRCC, a relay is energized that interrupts the necessary circuits in the weld power supply and robot controller. With the use of the voice recognition system as a safety control for this workcell, we have added a third level of redundancy into the emergency stopping ability of the operator (in addition to the present emergency stop buttons).
Manipulator motions are controlled through an axis select button in conjunction with a positive or negative jog button that is depressed by the operator. Once the operator has selected an axis, he depresses one of the jog buttons for the desired travel distance.This function was selected to be controlled by the VRCC because of its utilization during automatic operation of the manipulator to correct trajectory errors. The circuitry necessary to control this operation draws the signal to ground through the activation of relays for the positive or negative jog motion. Because motion is achieved only as long as these signals are active low. they can be controlled by discrete digital signals from the VRCC.
Analog Control Signals
There are many variables that affect the quality of weld during the welding process. but the welding current has the greatest effect over a small range of values. It was for this reason, that the welding current was chosen to be controlled by the voice recognition system.
The welding power supply controls the current level through a voltage circuit that uses a range of 0-10 V DC. These voltage values are converted to current levels from 0 to 300 A for welding. A digital-to-analog converter is used in conjunction with a multiplying circuit. The converter allows the VRCC to control a voltage level that is used by the weld power supply to achieve the proper welding current. The multiplier circuit is necessary to allow the weld power supply to be controlled by the other subcontroller used in the workcell.
Experimental Investigation
The accuracy and speed of response of corrections to robot manipulator motion and welding process variables made with the VRCC are being compared with those made with the original control system. Step input errors to robot motion and welding current are introduced randomly into the robot program. By graphically recording relevant system output signals,the time required for the operator to detect the change and initiate corrective action may be measured. Response accuracy and stability may also be gaged through similar analysis of the relevant recorded system output signals.
Conclusions
Future work will investigate voice control of welding filler wirefeed speed and location of wire entry into the weld pool. Also to be investigated is voice control of welding arc voltage override. Later, restriction of access to the robot program editor by voice recognition may be implemented.
The use of voice recognition technology for manual supervisory control of industrial robot systems is very promising. This technology has application for aerospace welding due to the need to have constant human supervision over a multitude of process parameters in real time. Future development of this technology will permit rapid expansion of its application to both robotic and nonrobotic processes.
Acknowledgment
Special thanks to Mr. Jeff Hudson of Martin Marietta Corporation for assistance in the preparation of the illustration presented in this article.
References
[1] C. A . Simpson. hl. E. McCauley. E. F. Rolland. J . C. Ruth. and B. H. Williges. "System Design for Speech Recognition and Generation." Hutnnn Factors. vol. 27. no. 2. pp.115-1-11. 1985.
[2] National Research Council. Committee on Computerized Speech Recognition Technologies.Automatic Speech Rerop1irior1 in severe Environments National Research Council.1984.
[3] E. J. Lerner. "Talking to Your Aircraft." Aerospace America. vol. 24. no. 2. pp. 85-88. 1986.
[4] J. T. Memlield. "Bosing Explores Voice Recognition for Future Transpon Flight Deck." Ariarinn Week and Space Techno/- og!. vol. 124. no. 16. pp. 85-91. 1986.
[5] A. Cohen and J. D. Erickson, ..Future Uses of Machine Intelligence and Robotics for the Space Station and Implications for the U.S. Economy.'' IEEE J. Robotics and Automarion.vol. SMC-16. pp. 1 11-12 I. Jan.iFeb.1986
[6] "Automation and Robotics for the National Space Program," California Space Institute Automation and Robotics Panel. Cal Space Repon CS1185-01, Feb. 25, 1985.
[7] "Advancing Automation and Robotics Technology for the Space Station and for the U.S. Economy." Advanced Technology AdvisoryCommittee. NASA TM 87566. Mar. 1985.
使用語(yǔ)音識(shí)別技術(shù)控制的焊接機(jī)器人工作單元
摘要：本文論述了使用聲音識(shí)別技術(shù)的焊接機(jī)器人工作單元在工作過(guò)程中的效果、程序編輯者接近機(jī)器人的安全﹑試行運(yùn)轉(zhuǎn)的必要性﹑焊接過(guò)程的控制變量﹑機(jī)器人操作者的動(dòng)作規(guī)范等因素給與考慮。在焊接過(guò)程控制和操作動(dòng)作兩個(gè)方面，按照反應(yīng)速度﹑定位精確性﹑焊接穩(wěn)定性﹑焊接可靠性和安全性把人工聲音控制與手工觸覺(jué)控制和完全自動(dòng)化控制進(jìn)行了比較。
緒論
聲音識(shí)別技術(shù)已經(jīng)成為可能緩解操作者工作負(fù)擔(dān)的一種有潛力的復(fù)雜系統(tǒng)。許多應(yīng)用已經(jīng)落實(shí),或正陸續(xù)開(kāi)發(fā),或正在研究之中。這些措施包括數(shù)據(jù)的輸入﹑飛機(jī)的控制﹑和以安全為目的的語(yǔ)音識(shí)別。
許多應(yīng)用語(yǔ)音控制技術(shù)還建議用于太空站. 一個(gè)主要的應(yīng)用領(lǐng)域?qū)C(jī)器人控制功能用于太空艙內(nèi)檢查、裝配、維修、衛(wèi)星回收、維修衛(wèi)星,是在船上服務(wù)的監(jiān)督能力和系統(tǒng)運(yùn)作模式的反饋. 聲音感應(yīng)器和過(guò)程控制的變數(shù)將使船員影響他手上的其它工作,例如直接控制或推翻的操縱議案。 同樣,利用工作量控制機(jī)載實(shí)驗(yàn)這種技術(shù)可以緩解許多工作負(fù)擔(dān)。
這份文件描述應(yīng)用語(yǔ)音識(shí)別控制的焊接機(jī)器人工作單元。 這是一個(gè)復(fù)雜的系統(tǒng),涉及多個(gè)傳感器及控制投入各種機(jī)械操作件和變化多樣的工藝參數(shù)。雖然許多功能是自動(dòng)化，且為人類監(jiān)督管理能力所控制,但在必要時(shí)隨時(shí)準(zhǔn)備超越這些功能。 在當(dāng)前的調(diào)查中， 在美國(guó)航天局的馬歇爾空間飛行中心可供商業(yè)使用語(yǔ)音識(shí)別系統(tǒng)結(jié)合了焊接機(jī)器人工作單元的技術(shù)，這一技術(shù)作為試點(diǎn)的評(píng)價(jià)和開(kāi)發(fā)先進(jìn)技術(shù)并用于制造航天飛機(jī)主發(fā)動(dòng)機(jī)。在系統(tǒng)開(kāi)發(fā)中，有些功能尚不具備自動(dòng)跟蹤控制,因此需要不斷地人力監(jiān)測(cè)和實(shí)時(shí)調(diào)整操作。目前,該系統(tǒng)投入方案是通過(guò)觸覺(jué)指令(即： 推動(dòng)按鈕. 旋轉(zhuǎn)電位計(jì)、或者調(diào)整機(jī)械裝置)。由于操作過(guò)程中,主要監(jiān)測(cè)者必須考慮在遠(yuǎn)離的過(guò)程中尋找適當(dāng)?shù)陌粹o或把手或靠像打字員一樣那種打字時(shí)的肌肉記憶。第二種情況，可能由于操作者的的二次反應(yīng)而增加了錯(cuò)誤發(fā)生的可能性。
一個(gè)語(yǔ)音識(shí)別系統(tǒng)可減少操作者的反應(yīng)時(shí)間。操作者按錯(cuò)按鈕的可能性了同樣的也會(huì)減少。并且,操作者勞累也會(huì)大大減小。
由于在方案運(yùn)行的過(guò)程中操作者不斷監(jiān)測(cè)，可以更快地觀察到運(yùn)行狀況改變所帶來(lái)的影響。 因此,如果超過(guò)了預(yù)期值,應(yīng)該更快糾正,，但不能太過(guò)度。 這對(duì)減少振蕩,使系統(tǒng)更加穩(wěn)定的實(shí)現(xiàn)了預(yù)期的價(jià)值。
另一個(gè)因素是可以改善操作者的安全.。在一個(gè)安全的緊急情況下，機(jī)器人的操作者可以采取緊急停止來(lái)停止其運(yùn)行，這種緊急停止模式一般來(lái)說(shuō)是設(shè)置一個(gè)大按鈕，按慣例是一種經(jīng)常用的方式。如果操作者無(wú)意中發(fā)現(xiàn)自己在危險(xiǎn)的情況下，這時(shí)也許他有必要采取緊急停止這種模式。如果操作者不能夠按到的按鈕，可他也沒(méi)有能力采取必要的行動(dòng)時(shí)，這樣下去，他可能會(huì)受重