3592 尾架體加工工藝及關(guān)鍵工序工裝設(shè)計(jì)
3592 尾架體加工工藝及關(guān)鍵工序工裝設(shè)計(jì),尾架體,加工,工藝,關(guān)鍵,癥結(jié),樞紐,工序,工裝,設(shè)計(jì)
機(jī)床生產(chǎn)率計(jì)算卡圖號(hào) 毛坯種類 鑄件名稱 尾架體 毛坯重量被加工零件材料 HT200 硬度 175～255HBS工序名稱 鉆 Φ14 孔 工序號(hào) 工時(shí)/min序號(hào) 工步名稱 工作行程/mm 切速/(m/min) 進(jìn)給量/(mm/r) 進(jìn)給量/(mm/min) 工進(jìn)時(shí)間輔助時(shí)間1 安裝工件 0.72 工件定位、夾緊 0.053 鉆頭快進(jìn) 200 5000 0.034 鉆頭工進(jìn) 38 78 0.11 6.6 1.595 死擋鐵停留 0.016 鉆頭快退 238 5000 0.0367 工件松開 0.058 卸下工件 0.7累計(jì) 0.159 1.576單件總工時(shí) 1.612機(jī)床生產(chǎn)率 37.22(件/h)理論生產(chǎn)率 25.64(件/h)備注1．一次安裝加工一個(gè)工件2．本機(jī)床裝卸工件時(shí)間取 1.4min負(fù)荷率 68.89%南京理工大學(xué)泰州科技學(xué)院畢業(yè)設(shè)計(jì)(論文)前期工作材料學(xué) 生 姓 名 : 張春雨 學(xué) 號(hào)： 05010106系 部 : 機(jī)械工程系專 業(yè) : 機(jī)械工程及自動(dòng)化設(shè)計(jì) (論 文 )題 目 : 尾架體加工工藝及關(guān)鍵工序工裝設(shè)計(jì)指 導(dǎo) 教 師 : 王栓虎 副教授材 料 目 錄序號(hào) 名 稱 數(shù)量 備 注1 畢業(yè)設(shè)計(jì)(論文)選題、審題表 12 畢業(yè)設(shè)計(jì)(論文)任務(wù)書 13 畢業(yè)設(shè)計(jì)(論文)開題報(bào)告〔含文獻(xiàn)綜述〕 14 畢業(yè)設(shè)計(jì)(論文)外文資料翻譯〔含原文〕 15 畢業(yè)設(shè)計(jì)（論文）中期檢查表 12009 年 5 月 南京理工大學(xué)泰州科技學(xué)院畢業(yè)設(shè)計(jì)（論文）任務(wù)書系 部 ： 機(jī)械工程系專 業(yè) ： 機(jī)械工程及自動(dòng)化學(xué) 生 姓 名： 張春雨學(xué) 號(hào)：05010106設(shè) 計(jì) (論 文 )題 目 ： 尾架體加工工藝及關(guān)鍵工序工裝設(shè)計(jì)起 迄 日 期 : 2008 年 3月 09 日 ~ 6 月 14 日設(shè)計(jì) (論文 )地點(diǎn) : 南京理工大學(xué)泰州科技學(xué)院指 導(dǎo) 教 師 : 王栓虎專 業(yè) 負(fù) 責(zé) 人 : 龔光容發(fā)任務(wù)書日期: 2009 年 2 月 26 日任務(wù)書填寫要求1．畢業(yè)設(shè)計(jì)（論文）任務(wù)書由指導(dǎo)教師根據(jù)各課題的具體情況填寫，經(jīng)學(xué)生所在專業(yè)的負(fù)責(zé)人審查、系部領(lǐng)導(dǎo)簽字后生效。此任務(wù)書應(yīng)在第七學(xué)期結(jié)束前填好并發(fā)給學(xué)生；2．任務(wù)書內(nèi)容必須用黑墨水筆工整書寫或按教務(wù)處統(tǒng)一設(shè)計(jì)的電子文檔標(biāo)準(zhǔn)格式（可從教務(wù)處網(wǎng)頁上下載）打印，不得隨便涂改或潦草書寫，禁止打印在其它紙上后剪貼；3．任務(wù)書內(nèi)填寫的內(nèi)容，必須和學(xué)生畢業(yè)設(shè)計(jì)（論文）完成的情況相一致，若有變更，應(yīng)當(dāng)經(jīng)過所在專業(yè)及系部主管領(lǐng)導(dǎo)審批后方可重新填寫；4．任務(wù)書內(nèi)有關(guān)“系部” 、 “專業(yè)”等名稱的填寫，應(yīng)寫中文全稱，不能寫數(shù)字代碼。學(xué)生的“學(xué)號(hào)”要寫全號(hào)；5．任務(wù)書內(nèi)“主要參考文獻(xiàn)”的填寫，應(yīng)按照國標(biāo) GB 7714—2005《文后參考文獻(xiàn)著錄規(guī)則》的要求書寫，不能有隨意性；6．有關(guān)年月日等日期的填寫，應(yīng)當(dāng)按照國標(biāo) GB/T 7408—2005《數(shù)據(jù)元和交換格式、信息交換、日期和時(shí)間表示法》規(guī)定的要求，一律用阿拉伯?dāng)?shù)字書寫。如“2008 年 3 月 15 日”或“2008-03-15”。畢 業(yè) 設(shè) 計(jì)（論 文）任 務(wù) 書1．本畢業(yè)設(shè)計(jì)（論文）課題應(yīng)達(dá)到的目的：尾架體是某企業(yè)產(chǎn)品中的關(guān)鍵零件之一，生產(chǎn)量比較大。為了保證產(chǎn)品質(zhì)量，提高加工效率，需要對(duì)其加工工藝進(jìn)行優(yōu)化設(shè)計(jì)，并在關(guān)鍵工序使用組合機(jī)床或?qū)Ｓ脵C(jī)床進(jìn)行加工。本課題即以此為背景，要求學(xué)生根據(jù)企業(yè)生產(chǎn)需要和尾架體零件的加工要求，首先完成零件的加工工藝規(guī)程設(shè)計(jì)，在此基礎(chǔ)之上，選擇其關(guān)鍵工序之一進(jìn)行專用夾具及加工用組合機(jī)床設(shè)計(jì)，并完成必要的設(shè)計(jì)計(jì)算。通過這樣一個(gè)典型環(huán)節(jié)綜合訓(xùn)練，達(dá)到綜合訓(xùn)練學(xué)生運(yùn)用所學(xué)知識(shí)，解決工程實(shí)際問題的能力。2．本畢業(yè)設(shè)計(jì)（論文）課題任務(wù)的內(nèi)容和要求（包括原始數(shù)據(jù)、技術(shù)要求、工作要求等）：本課題要求學(xué)生在對(duì)尾架體的加工要求、零件的結(jié)構(gòu)工藝性進(jìn)行認(rèn)真分析的基礎(chǔ)上，首先對(duì)零件的加工工藝規(guī)程做出優(yōu)化設(shè)計(jì)，并對(duì)其關(guān)鍵工序之一進(jìn)行專用夾具及加工用組合機(jī)床設(shè)計(jì)。具體任務(wù)及要求如下：（1）調(diào)查研究、查閱及翻譯文獻(xiàn)資料，撰寫開題報(bào)告；（2）尾架體加工要求、零件的結(jié)構(gòu)工藝性分析；（3）尾架體加工工藝規(guī)程設(shè)計(jì)；（4）尾架體關(guān)鍵工序的專用夾具設(shè)計(jì)；（5）尾架體關(guān)鍵工序的組合機(jī)床設(shè)計(jì)；（6）必要的設(shè)計(jì)計(jì)算與分析；（7）文檔整理、撰寫畢業(yè)設(shè)計(jì)說明書及使用說明書。設(shè)計(jì)技術(shù)要求包括：（1）生產(chǎn)綱領(lǐng) 50000 件/年（2）夾具采用液壓驅(qū)動(dòng)（3）組合機(jī)床采用液壓滑臺(tái)（4）每次加工一個(gè)零件畢 業(yè) 設(shè) 計(jì)（論 文）任 務(wù) 書3．對(duì)本畢業(yè)設(shè)計(jì)（論文）課題成果的要求〔包括畢業(yè)設(shè)計(jì)論文、圖表、實(shí)物樣品等〕：（1）開題報(bào)告、文獻(xiàn)綜述、資料翻譯；（2）尾架體加工工藝過程綜合卡及各工序工序卡；（3）尾架體零件圖及夾具裝配圖；（4）組合機(jī)床設(shè)計(jì)資料（三圖一卡） ；（5）畢業(yè)設(shè)計(jì)說明書。 4．主要參考文獻(xiàn)：[1] 裘愉弢主編. 組合機(jī)床［M］. 第 1 版.北京：機(jī)械工業(yè)出版社，1995.[2] 金振華主編.組合機(jī)床及其調(diào)整與使用［M］. 第 1 版.北京：機(jī)械工業(yè)出版社，1990.[3] 沈延山.生產(chǎn)實(shí)習(xí)與組合機(jī)床設(shè)計(jì)［D］.第 1 版.大連：大連理工大學(xué)出版社，1989.[4] 上海市大專院校機(jī)械制造工藝學(xué)協(xié)作組編著.機(jī)械制造工藝學(xué)［M］ （修訂版）.福建科學(xué)技術(shù)出版社，1996.[5] 王華坤，范元?jiǎng)拙?機(jī)械設(shè)計(jì)基礎(chǔ)［M］.北京：兵器工業(yè)出版社，2000.[6] 馮辛安等編.機(jī)械制造裝備設(shè)計(jì)［M］. 北京：機(jī)械工業(yè)出版社,1998.[7] 陳日曜主編.金屬切削原理［M］. 第 2 版.北京：機(jī)械工業(yè)出版社,1992.[8] 方子良等編.機(jī)械制造技術(shù)基礎(chǔ)［M］.上海：上海交通大學(xué)出版社，2004.[9] 劉秋生，李忠文主編.液壓傳動(dòng)與控制［M］.北京：宇航出版社，1994.[10] 陳于萍，周兆元等.互換性與測量技術(shù)基礎(chǔ)［M］. 第 2 版.北京：機(jī)械工業(yè)出版社,2005.[11] 東北重型機(jī)械學(xué)院等合編.機(jī)床夾具設(shè)計(jì)手冊(cè)［M］.上海：上?？茖W(xué)技術(shù)出版社，1979.[12]《機(jī)械設(shè)計(jì)手冊(cè)》聯(lián)合編寫組. 機(jī)械設(shè)計(jì)手冊(cè)［M］. 第 2 版.北京：機(jī)械工業(yè)出版社,1987.畢 業(yè) 設(shè) 計(jì)（論 文）任 務(wù) 書5．本畢業(yè)設(shè)計(jì)（論文）課題工作進(jìn)度計(jì)劃：起 迄 日 期 工 作 內(nèi) 容2009 年3 月 09 日 ～ 3 月 15 日3 月 16 日 ～ 3 月 29 日3 月 30 日 ～ 4 月 19 日4 月 20 日 ～ 5 月 03 日5 月 04 日 ～ 5 月 31 日6 月 01 日 ～ 6 月 07 日6 月 08 日 ～ 6 月 14 日熟悉畢業(yè)設(shè)計(jì)要求。查閱資料，完成外文資料翻譯工作撰寫開題報(bào)告及文獻(xiàn)綜述尾架體加工工藝規(guī)程設(shè)計(jì)（至少提出 2 個(gè)方案，進(jìn)行分析比較，最后決定一個(gè)較優(yōu)的方案）夾具設(shè)計(jì)（至少提出 2 個(gè)方案，進(jìn)行分析比較，最后決定一個(gè)較優(yōu)的方案）組合機(jī)床設(shè)計(jì)（完成三圖一卡）文檔整理、撰寫畢業(yè)設(shè)計(jì)說明書。論文答辯所在專業(yè)審查意見：負(fù)責(zé)人： 2009 年 月 日系部意見：系部主任： 2009 年 月 日 南京理工大學(xué)泰州科技學(xué)院畢業(yè)設(shè)計(jì)(論文)外文資料翻譯系 部： 機(jī)械工程系 專 業(yè)： 機(jī)械工程及自動(dòng)化 姓 名： 張春雨 學(xué) 號(hào)： 05010106 外文出處： Design of the Distributed Architecture of a Machine-tool 附 件： 1.外文資料翻譯譯文；2.外文原文。指導(dǎo)教師評(píng)語：簽名： 年 月 日分布式機(jī)床的設(shè)計(jì)FIP現(xiàn)場總線的用途Daping SONG, Thierry DIVOUX，費(fèi)朗西斯勒帕熱自動(dòng)化中心研究所的Nancy摘要：本文中我們基于FIP現(xiàn)場總線上提出了一種分布式控制系統(tǒng)。它將取代傳統(tǒng)的CNC(計(jì)算機(jī)數(shù)字控制裝置)用于機(jī)床上。該系統(tǒng)是由一套以微處理機(jī)為基礎(chǔ)的模塊(PC機(jī)、運(yùn)動(dòng)控制器、I/O接口) 利用FLP實(shí)時(shí)網(wǎng)絡(luò)相互聯(lián)接的。這主要是使每個(gè)模塊智能化以提高整個(gè)系統(tǒng)的靈活性和容錯(cuò)能力。每個(gè)模塊都是一個(gè)分控系統(tǒng)，用于實(shí)現(xiàn)自己的分控任務(wù)，其中有些模塊用于運(yùn)動(dòng)控制，另一些模塊用于傳感器評(píng)價(jià)和執(zhí)行器調(diào)節(jié)。FIP決定了這些模塊之間的通訊（信息交流和同步），同時(shí)執(zhí)行任務(wù)分配以及設(shè)備布局分布。我們討論一些分布標(biāo)準(zhǔn)并描述實(shí)驗(yàn)的執(zhí)行。1.引言近幾年，一直對(duì)分布式體系結(jié)構(gòu)進(jìn)行了許多研究。分布式體系結(jié)構(gòu)在系統(tǒng)集成上發(fā)揮主要作用。在機(jī)床控制域，目前 CNC 技術(shù)有它內(nèi)在的缺點(diǎn)。將幾根固定數(shù)量的軸容入 CIM 環(huán)境中是非常費(fèi)時(shí)，靈活和不易的。超大規(guī)模集成電路微處理器技術(shù)和通信網(wǎng)絡(luò)的迅速發(fā)展使分布式控制成為可能。雖然逐步擴(kuò)展沒有完全替代硬件更換但分布式控制系統(tǒng)的性能，模塊化，完整性和可靠性正在提高。它為替代控制系統(tǒng)架構(gòu)提供了一個(gè)很好的前景。本文致力于對(duì)分布式機(jī)床結(jié)構(gòu)的研究。它建立在智能設(shè)備與通信相聯(lián)系的基礎(chǔ)上。分布式機(jī)床的特點(diǎn)是分布式任務(wù)和分布式數(shù)據(jù)，且具有獨(dú)特的控制方法。它是結(jié)合標(biāo)準(zhǔn)設(shè)備和 FIP 系統(tǒng)總線設(shè)計(jì)而成，通過實(shí)驗(yàn)證明該系統(tǒng)具有可執(zhí)行性，在實(shí)驗(yàn)中該系統(tǒng)控制了復(fù)合軸系，成功執(zhí)行坐標(biāo)之間的關(guān)系同時(shí)也反應(yīng)了對(duì)傳感器值的變化。該論文結(jié)構(gòu)如下：第 2 部分描述了機(jī)床控制系統(tǒng)構(gòu)架。第 3 部分簡要介紹了 FIP 現(xiàn)場總線。第 4 部分概述了我們實(shí)驗(yàn)的實(shí)施。最后，我們?cè)诘?5 部分總結(jié)了一些一般性意見和今后的研究前景。2.機(jī)床控制系統(tǒng)架構(gòu)該機(jī)床控制系統(tǒng)是一個(gè)實(shí)時(shí)多任務(wù)系統(tǒng)。其功能結(jié)構(gòu)如圖 1 所示。它包括三種單元：用戶接口/ 監(jiān)控單元/規(guī)劃單元，伺服單元，傳感器/制動(dòng)器單位。這個(gè)系統(tǒng)的主要功能是用來控制工件的加工。它包括兩個(gè)不同的和相關(guān)的任務(wù)：● 為了確保軌跡的準(zhǔn)確性和對(duì)機(jī)床移動(dòng)部件的速度控制● 為了調(diào)查定位（跟蹤）過程的正確執(zhí)行，環(huán)境變化的影響與指定操作的執(zhí)行或機(jī)床機(jī)件的運(yùn)動(dòng)同樣重要。例如：工具開關(guān)，冷卻，潤滑等。CAM 的制造日期圖 1：架構(gòu)功能按時(shí)間順序，這項(xiàng)任務(wù)也可分為兩個(gè)步驟：規(guī)劃控制程序規(guī)劃和執(zhí)行控制程序。第一步，機(jī)床機(jī)件沒有直接的方向，只有運(yùn)動(dòng)和被指定執(zhí)行的操作，這是“數(shù)據(jù)采集和預(yù)處理”的一步。雖然在第二步，是控制的有效執(zhí)行。值得指出的是：在第二步由于多任務(wù)的性質(zhì)，并行處理是可行的。3.FIP 現(xiàn)場總線FIP系統(tǒng)被用來滿足分布式機(jī)床上實(shí)時(shí)通信的需要。在這一節(jié)中，我們簡要地解釋一下FIP系統(tǒng)的技術(shù)性能。FIP（工廠儀表協(xié)議）是網(wǎng)絡(luò)系統(tǒng)用于傳感器的驅(qū)動(dòng)器和控制設(shè)備如工作規(guī)劃/編程（軌跡，工具的選擇，其他加工參數(shù)采集）基本替換計(jì)算軸伺服控制系統(tǒng)機(jī)床構(gòu)件傳感器/制動(dòng)器環(huán)境自動(dòng)安全監(jiān)測加工PLCS，CNCS或機(jī)器人控制器之間的信息交換。FIP系統(tǒng)的結(jié)構(gòu)采用所謂的密封性以減少OSI模型(物理層,數(shù)據(jù)鏈路層和應(yīng)用層)，這種結(jié)構(gòu)使實(shí)時(shí)通信和常規(guī)的信息溝通之間有明顯的區(qū)別。在數(shù)據(jù)鏈路層中，相關(guān)服務(wù)一方面與其他傳遞信息服務(wù)可變轉(zhuǎn)讓。在應(yīng)用層中，我們可區(qū)分MPS服務(wù)（制造周期/非制造性規(guī)范），它采用來自數(shù)據(jù)鏈路層的信息設(shè)備所支持的MMS設(shè)備。FIP支持兩個(gè)傳輸媒體：屏蔽雙絞線和光纖。FIP允許各種各樣的布局，最長部分可達(dá)500米，至少有4個(gè)部分被中繼器代替。3種比特率被確定為：31.25k.比特/秒，1兆位/秒和2.5兆位/秒。FIP介質(zhì)訪問控制是集中的。所有轉(zhuǎn)讓都由the Bus Arbiter控制，時(shí)間安排轉(zhuǎn)移必須遵守時(shí)間要求。變量和信息之間的傳遞可采用定期配置或根據(jù)站的要求來轉(zhuǎn)讓，而在我們的應(yīng)用中，F(xiàn)IP只采用可變轉(zhuǎn)讓。FIP采用生產(chǎn)者和消費(fèi)者的模樣來產(chǎn)生可變交流。變量對(duì)于生產(chǎn)者和消費(fèi)者而言，是被確定的一個(gè)獨(dú)特的識(shí)別標(biāo)志，一套制作和消費(fèi)變量可以集結(jié)在一個(gè)站，但是這些識(shí)別標(biāo)志不涉及任何物理地址站。圖2顯示了變化信息。廣播的 BA 標(biāo)識(shí)符 認(rèn)識(shí)的人 P和一些消費(fèi)者?生產(chǎn)者發(fā)出的日期 P所有消費(fèi)者接受的數(shù)據(jù) C 圖2：FIP系統(tǒng)的MAC圖象首先，the Bus Arbiter 廣播持有可變的標(biāo)示符，所有的節(jié)點(diǎn)接受幀并檢查變數(shù)是生產(chǎn)還是消費(fèi)產(chǎn)生的或不給予影響。第三步：作為生產(chǎn)者的站必須響應(yīng)包含數(shù)據(jù)的幀。第四步：獲取消費(fèi)者的變化價(jià)值并存儲(chǔ)。當(dāng)更新產(chǎn)生時(shí)，消費(fèi)者和生產(chǎn)者便形成了。FIP有兩種類型的數(shù)據(jù)交流：周期性和非周期性的。在這兩種情況下，匯率發(fā)生情況如上圖（圖2）。在第一種情況下，the Bus Arbiter根據(jù)從配置要求價(jià)值相應(yīng)的標(biāo)識(shí)定期轉(zhuǎn)移。第二種情況下，the Bus Arbiter 可根據(jù)現(xiàn)有的帶寬產(chǎn)生轉(zhuǎn)讓請(qǐng)求信號(hào)。在我們的應(yīng)用中，實(shí)時(shí)的限制是非常嚴(yán)格的。為了使機(jī)床遵守給定的軌跡，軸的控制必須同步。這就要求和網(wǎng)絡(luò)連接的控制節(jié)點(diǎn)應(yīng)該同時(shí)接受開始命令，因此網(wǎng)絡(luò)必須播出命令。為了確保相同的瞬時(shí)命令能同時(shí)被幾個(gè)接受器接受，穩(wěn)定的傳輸是非常必要的。因此，一些傳感器例如運(yùn)動(dòng)控制傳感器就應(yīng)該要求定期調(diào)查限位開關(guān)以使網(wǎng)絡(luò)能定期無重大延誤的傳輸數(shù)據(jù)。一句話，像分布式機(jī)床的操作，像數(shù)據(jù)廣播的要求，時(shí)間和空間的一致性，定期傳輸不能滿足任何一般用途的網(wǎng)絡(luò)。然而，實(shí)時(shí)網(wǎng)絡(luò)例如FIP就是數(shù)據(jù)一種好的解決方法。4.實(shí)驗(yàn)實(shí)施如圖3所示，我們的應(yīng)用目標(biāo)是要實(shí)現(xiàn)一個(gè)分布式的兩軸機(jī)床控制系統(tǒng)。它由以下設(shè)備分布在FIP總線的四個(gè)節(jié)點(diǎn)上。節(jié)點(diǎn)1：微機(jī)（i80486 微處理器）。它作為運(yùn)營商終端。節(jié)點(diǎn)2.3：兩個(gè)相同的節(jié)點(diǎn)。每個(gè)均由微機(jī)（i80486）配備了運(yùn)動(dòng)控制器(克萊斯勒PCIOO + 克萊斯勒三菱商事100)。節(jié)點(diǎn)4：一個(gè)帶有傳感器/制動(dòng)器作為輔助業(yè)務(wù)的可編程控制器（低溫100）。網(wǎng)絡(luò)：FIP和1比特/秒的雙絞線介質(zhì)間的選擇。軟件架構(gòu)的執(zhí)行系統(tǒng)是基于概念的多層次分布式控制。它有三種層次結(jié)構(gòu)，其中第二和第三層次可實(shí)現(xiàn)分配。它包括以下層次：分析層：控制任務(wù)的執(zhí)行選擇它被映射到微機(jī)的提供用戶界面的節(jié)點(diǎn)上。用來處理計(jì)劃收購和儲(chǔ)存，不同業(yè)務(wù)模式（手動(dòng)和自動(dòng)模式）的交換，起始點(diǎn)和終點(diǎn)以及其它各節(jié)點(diǎn)之間的計(jì)算和發(fā)送。慣例層：確定某一任務(wù)的控制算法它被映射到2種其他微機(jī)上（節(jié)點(diǎn)2和節(jié)點(diǎn)3）。這兩種微機(jī)具有根據(jù)給定的參數(shù)和命令（軌跡類型，速度，加速度等）進(jìn)行基本位移計(jì)算（插補(bǔ)）的功能。每個(gè)軸的插補(bǔ)算法是軟件設(shè)計(jì)的困難之一，因?yàn)檩S控制分布后，每個(gè)中間坐標(biāo)軸的計(jì)算是獨(dú)立的。正確的算法設(shè)計(jì)可保證這些軸的連貫性。工藝層：執(zhí)行控制它包含兩種運(yùn)動(dòng)：運(yùn)動(dòng)控制器和可編程控制器。這些設(shè)備執(zhí)行伺服系統(tǒng)運(yùn)動(dòng)控制，處理加工件的舉行/緊縮政策，傳感器的評(píng)定和驅(qū)動(dòng)器的調(diào)節(jié)使工具切換任務(wù)和監(jiān)控系統(tǒng)更安全。為了驗(yàn)證擬議的架構(gòu)是否與時(shí)間限制和網(wǎng)絡(luò)能力相適應(yīng)，預(yù)期流量的估計(jì)是必要的。主要有兩種性質(zhì)的信息交流：● 命令從中央決定站（節(jié)點(diǎn)）傳到其它站?！?統(tǒng)計(jì)信息由站（節(jié)點(diǎn)）與站之間產(chǎn)生。例如:在我們的實(shí)驗(yàn)平臺(tái)上,一些變數(shù)分布如下：節(jié)點(diǎn)1節(jié)點(diǎn)2 節(jié)點(diǎn)4 節(jié)點(diǎn)3FIP系統(tǒng) FIP系統(tǒng)運(yùn)動(dòng)控制 運(yùn)動(dòng)控制傳感器和制動(dòng)器FIP 系統(tǒng) X軸 Y軸圖3:硬件執(zhí)行5.結(jié)論本文中為滿足CIM的要求，我們的研究通過實(shí)驗(yàn)實(shí)施進(jìn)一步達(dá)到審定。我們現(xiàn)在正致力于用來證明符合執(zhí)行實(shí)時(shí)限制的經(jīng)營架構(gòu)的仿真和性能分析的工作。我們的目標(biāo)不僅是一個(gè)試樣樣機(jī)，更是研究設(shè)計(jì)、優(yōu)化的分布式系統(tǒng)理論方案的發(fā)展。Design of the Distributed Architecture of a Machine-toolUsing FIP FieldbusDaping SONG, Thierry DIVOUX, Francis LEPAGECentre de Recherche en Automatique de NancyUniversite de Nancy I, BP239, 54506 Vandoeuvre-les-Nancy cedex, FranceAbstract: In this paper we propose a distributed control system based on FIP fieldbus. It is applied to machine-tool as a replacement for the traditional CNC (Computerized Numerical Controller). The system is composed of a set of microprocessor-based modules (PCs, motion controllers, I/OS, . ..) interconnected by FLP real-time network. The main idea is to enable each module to be intelligent, improving thus the flexibility and the fault tolerant capability of the whole system. Each module being a sub-control system, accomplishes its own control task, some of them for motion control and others for evaluating sensors and regulating actuators. The communication (information exchanges and synchronization) among these modules is ensured by FLP. This system allows both task distribution as well as equtpment topological distribution. We discuss some distribution criteria and describe an experimental implementation.1. IntroductionDistributed system architecture has been the subject of many research activities in recent years. It plays a major role in systems integration. In the machine-tool control domain, present CNC technology has its inherent shortcomings. It is centralized, limited to a fixed number of axis time-consuming, inflexible and difficult to be integrated in CIM environment. The rapid development of VLSI microprocessor technology and communication network enables the distributed control to be considered. Distributed control systems present the advantage of improving performance, modularity, integrity and reliability while allowing incremental expansion without complete hardware replacement. It offers a promising alternative to control system architecture.This paper is dedicated to study a distributed machine-tool architecture. It is based on intelligent devices interconnected on communication link. It is characterized by distributed tasks and distributed data, but with unique control access system. It is designed by using standard devices and FIP fieldbus and verified by a experimental implementation, in which the system controls a multi-axis machine to successfully execute a coordinated motion as well as to respond to sensors values changes.The paper is organized as follows. In section 2, the machine-tool control system architecture is described. Section 2 gives a brief description of FIP and Section 3 outlines our experimental implementation. We conclude in section 4 with some general remarks and future research perspectives.2. Machine-tool control system architectureThe machine-tool control system is a real-time and multitask system. Its classical functional architecture is shown in Fig.1. It consists of three units: user interface/supervisiou/programming unit, servo unit, and sensors/actuators unit. The main mission of this system is to control workpart machining. It includes two different and related tasks aspects: ●to ensure the precise trajectory and speed control of the mobile organs of machine-tool.●to survey the correct execution of this positioning (tracking) process, to react on environment changes as well as to perform the specified operations or actions upon machine-tool mechanics. such as tool switching, cooling, lubricating, etc. Fig. 1 Functional architectureChronologically, this mission is also divided into two steps: control program planning and control program executiug. In the first step, there is no direct action on machine-tool multitask nature: “data acquisition and preprocessing” step. While in the second step, the control is effectively executed. It is worth to note that in the second step, the parallelization is possible due to the mechanics, only the motions as well as the operations to be performed are specified. This is the “data acquisition and preprocessing” step. While in the second step, the control is effectively executed. It is worth to note that in the second step, the parallelization is possible due to themultitask nature.3.FIP fieldbusTo meet the real-time communication need in our distributed machine-tool, FIP is adopted. In this section, we briefly explain the main technical properties of FIP.FIP (Factory Instrumentation Protocol) is an industrial network designed for the exchange of information between sensors, actuators and control devices such as PLCs, CNCs or robotcontrollers. The architecture of FIP follows the so-calkd reduced OS1 model (Physical layer, Data link layer and Application layer). This architecture makes a clear distinction between real-time communication and conventional message communication. At Data Link layer, there are services associated to variable transfers on the one hand and conventional messaging services on the other hand. At Application layer, we distinguish the MPS (Manufacturing Periodic/aperiodic Specification) services which use variable transfers of Data Link layer from the MMS services which are supported by the messaging services of the Data Link layer.FlP supports two transmission media: shielded twisted pair and optical fiber. It allows for a wide variety of topologies. The maximum length of a segment is 500 m ;and at most 4 segmentsare authorized with repeaters. Three bit rates have been defined: 31.25 K.bit/s, 1 Mbit/s and 2.5 Mbit/s.FIP medium access control is centralized. All transfers are under control of the Bus Arbiter that schedules transfers to comply with timing requirements. Transfers of variables and messages may take place periodically according to system configuration or aperiodicalIy under request from any station. In our application, only variable transfer of FIP is used.For variable exchanges, FIP uses the producer-consumer model. ‘Variables are identified by a unique identifier known from the producer and the consumers. A set of produced and consumed variables can be regrouped in one station, but the identifier is not related to any physical address of stations. Fig. 2 shows the broadcast of a variable.Fig2 Principle of MAC protocol of FIPFirst, the Bus Arbiter broadcasts a frame that holds the identifier of the variable. All nodes receive the frame and check whether they are producer or consumer of the variable or not concerned. In a third step, the station that recognizes itself as the producer replies with a response frame that contains the data. In a fourth step, all the consumers of this variable capture the value and store it. The consumers and the producer are formed when the update takes place.FlP defines two types of data exchanges: periodic and aperiodic. In both cases, the exchange takes place as indicated above (Fig. 6). In the first case, the Bus Arbiter knows from the configuration that it has to request periodically the transfer of the value corresponding to an identifier. In the second case, transfer requests are signaled to the Bus Arbiter that will serve them according to the available bandwidth.For our application, the real-time constraints are very stringent. To make the machine-tool to follow an accurate trajectory, the control of the axis must be synchronized. This requires that the control nodes connected by a network should simultaneously receive the starting order, so the network should be able to broadcast orders. To ensure that an order of the same instant is received by several receivers, a spacec onsistency statue is also necessary. For responsiveness reason, some sensors like movement-limit switches should be polled periodically requiring that the network be able to transmit periodic data without important delays.In one word, for an application like distributed machine-tool, the requirements like broadcast of data , the time and space consistencies, the periodic transmission can not be met by any general-purpose networks, a real-time network like FIP is then a good solution.4. Experimental implementationAs shown in Fig. 3, our application is aiming to realize a distributed two-axis machine-tool control system. It is composed of the following devices distributed on four nodes over FIP fieldbus:node1: a microcomputer (i80486 microprocessor). It is used as operator terminal,node 2. 3: two identical nodes. Each consists of a microcomputer (i80486) equipped with a motion controller (DCX PClOO+DCX MC 100).node 4: a PLC (LT 100) with sensors/actuators for auxiliary operations.network: FIP with 1Mbits/s over twisted pair medium is chosen.The software architecture of the implemented system is based on the concept of multilayered distributed control. It has a three-level hierarchy and the distribution is realizes at the second and the third levels. It consists the following layers:Analysis layer: performs selection of the control tasksIt is mapped on to the microcomputer of node 1 which provides an user interface. It deals with the program acquisition and storage, switches the different operational modes (manual and automatic modes), computes and sends the start and arrival points coordinates as well as other orders to each other node respectively.Rule layer: determines the control algorithms for a given task.It is mapped on to the two other microcomputers (node 2 and 3) which function is elementary displacements calculation (by interpolation) according to the given parameters and orders ( trajectory type, speed, acceleration,. etc.).One of the software design difficulties is the interpolation algorithms for each axis. Because after axis control distribution, the calculation of the intermediate coordinates of each axis becomes independent, the coherence of these axis should be ensured by correct algorithm design.Process layer: executes the control.It includes the two motion controllers and the PLC. These devices executes servo systemmotion control, handles the workpart holding/tightening, tools switch tasks and monitors system safety by evaluation of sensors and regulation of actuators.In order to verify if the proposed architecture is suitable with time constraints and network capacity, in is necessary to estimate the expected traffic.There are mainly two natures of information exchanges:●orders from central decision station (node 1) to other stations.●state information produced by the stations ( node1) to other stations.For example concerning our experimental platform, we have delined some variables distributed as following:Fig3 Hardware implementation5. Conclusionln this paper, we investigated a distributed machine-tool architecture in order to meet CIM requirements. Our research reached the step of validation through the realization of anexperimental implementation. We currently work on the simulation and performance analysis of the operating architecture to justify that the implementation meets real-time constraints. Our objectiveis not only an experimental prototype, but also the development of the theoretical methodology for the design, optimization of this distributed system.
收藏