【正文】 s Day! in shops, hotels and restaurants. But few young women will mark the festival with their boyfriends, or take part in traditional activities to pray for cleverness. 39 。s Day on February 14, characterized by bouquets of roses, chocolates and romantic candlelight dinners, than they do about their homegrown day for lovers. Even Qixi is nowadays referred to as the Chinese Valentine39。s misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the seventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BCAD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the Begging for Skills Festival or Daughters39。s time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If itShutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a moment of the nature wonder. You cannot miss out the Autumn of Arxan. It is definitely the best with brightlycolored scenery full of emotions. Nestled close to the country39。llw (2001), pp. 317–321附錄A REVIEW ON KINEMATICS OF請您刪除一下內(nèi)容，O(∩_∩)O謝謝?。。any people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the sevenday Chinese National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may bee more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to nightmare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and acmodation prices, with the possibility that there will be no rooms available. It is also mon that you39。參考文獻(xiàn)[1]孔德文，趙克利，[M]. 北京：化學(xué)工業(yè)出版社，2007[2]李宏，[M].北京:化學(xué)工業(yè)出版社，2009[3]文九巴主編. 機(jī)械工程材料[M] 北京：機(jī)械工業(yè)出版社. :P131174[4]勇主編. 現(xiàn)代公路施工機(jī)械[M] 北京：人民交通出版社. 1999:P6674[5]韓玉龍主編. Pro/E Wildfire組件設(shè)計(jì)與運(yùn)動(dòng)仿真專業(yè)教程[M］.北京：[6]蘇厚合, /ENGINEER2001入門指南[M].北京:[7][M].北京：[8]王為，[M].武漢：華中科技大學(xué)出版設(shè)。此外，在畢業(yè)設(shè)計(jì)的3個(gè)多月中，我和同學(xué)相互學(xué)習(xí)，相互鼓勵(lì)和改進(jìn)，也謝謝你們的真摯友情，這是我一輩子的財(cái)富。所以，也借此感謝四年來曾經(jīng)教育過、指導(dǎo)過、幫助過我的所有老師。這次畢業(yè)設(shè)計(jì)的順利完成，是前期四年知識和技能的積累。他嚴(yán)謹(jǐn)?shù)闹螌W(xué)態(tài)度，溫和的說教方式，靈活的視角，豐富的學(xué)識和經(jīng)驗(yàn)，都深深的影響了我，為我樹立了一個(gè)良好的榜樣。在每個(gè)階段，為我設(shè)定計(jì)劃，指明方向，搜尋資料，解答我的困惑，幫助推進(jìn)我的設(shè)計(jì)進(jìn)程。學(xué)無止境，我會(huì)在以后加強(qiáng)理論與實(shí)踐的學(xué)習(xí)，增加設(shè)計(jì)的可行性，真正將所學(xué)應(yīng)用到工作中，充實(shí)提升自己，爭取做一位合格負(fù)責(zé)的設(shè)計(jì)人員。其中借鑒了一些他人的研究成果，加以自己的理解和計(jì)算。這些都是我以后的學(xué)習(xí)生活的寶貴經(jīng)驗(yàn)。在設(shè)計(jì)的過程中，我更加細(xì)致地學(xué)習(xí)了Pro/E軟件，尤其是機(jī)構(gòu)分析及運(yùn)動(dòng)仿真的模塊。本文重點(diǎn)描述了挖掘機(jī)工作裝置的運(yùn)動(dòng)分析，建模和仿真的過程。我從頭開始準(zhǔn)備，學(xué)習(xí)搜集資料，計(jì)算，三維建模，運(yùn)動(dòng)仿真。對挖掘機(jī)的認(rèn)識，我以前只是在生活中看到在房屋建設(shè)挖地基時(shí)，它的整體挖掘動(dòng)作的運(yùn)動(dòng)情況。 圖513 挖掘機(jī)鏟斗的軌跡曲線 測量曲線 點(diǎn)擊——點(diǎn)擊新建——選取點(diǎn)（鏟斗的邊末端）——點(diǎn)擊坐標(biāo)系——選取X分量——點(diǎn)擊確定——回到原來的界面——即出現(xiàn)以下的圖像。 圖59 挖掘機(jī)仿真運(yùn)動(dòng)狀態(tài)1 圖510 挖掘機(jī)仿真運(yùn)動(dòng)狀態(tài)2 圖511挖掘機(jī)仿真運(yùn)動(dòng)狀態(tài) 3 圖512挖掘機(jī)仿真運(yùn)動(dòng)狀態(tài)4 運(yùn)動(dòng)軌跡曲線 在機(jī)構(gòu)分析模塊中，選擇插入——軌跡曲線——選取點(diǎn)（鏟斗邊末端）——選取結(jié)果集中的文件——選取曲線類型為3D，點(diǎn)確定，則出現(xiàn)挖掘機(jī)鏟斗運(yùn)動(dòng)的3維運(yùn)動(dòng)軌跡曲線。在設(shè)置完電機(jī)的那個(gè)分析定義頁面，點(diǎn)擊首選項(xiàng)，設(shè)置終止時(shí)間為74S，初始配置為快照3，點(diǎn)擊運(yùn)行，則開始進(jìn)行運(yùn)動(dòng)仿真。上述參數(shù)是經(jīng)調(diào)整后適合的參數(shù)，調(diào)整過程不再贅述。點(diǎn)擊機(jī)構(gòu)分析圖標(biāo)，按照下圖，輸入每個(gè)電機(jī)的開始和終止時(shí)間，實(shí)現(xiàn)多電機(jī)分時(shí)段產(chǎn)生作用，共同完成挖掘機(jī)的整個(gè)工作運(yùn)動(dòng)過程。完成電機(jī)1的設(shè)置。每個(gè)液壓缸的設(shè)置步驟相似，在此僅詳述電機(jī)1的設(shè)置過程。圖52 快照3的選擇圖53 快照3 設(shè)置伺服電動(dòng)機(jī)經(jīng)過觀察和分析將挖掘機(jī)的整個(gè)工作循環(huán)過程分解為3個(gè)液壓缸伸縮動(dòng)作的組合，按照時(shí)間的先后順序和動(dòng)作持續(xù)時(shí)間的合理安排，完成仿真。我們現(xiàn)在已經(jīng)裝配獲得了挖掘機(jī)的整機(jī)造型，首先通過拖動(dòng)，調(diào)整挖掘機(jī)工作設(shè)置到合適的位置，確定仿真的初始狀態(tài)和位置，然后進(jìn)行快照。電動(dòng)機(jī)的輪廓選項(xiàng)：可以指定伺服電動(dòng)機(jī)的位置、速度、加速度隨時(shí)間變化而變化的規(guī)律。幾何伺服電機(jī)：用于創(chuàng)建復(fù)雜的運(yùn)動(dòng)。運(yùn)動(dòng)軸伺服電機(jī)：用于定義某一旋轉(zhuǎn)軸的旋轉(zhuǎn)運(yùn)動(dòng)，只需選擇一個(gè)由連接所定義的旋轉(zhuǎn)軸，并設(shè)定方向即可。伺服電動(dòng)機(jī)的相關(guān)名詞解釋伺服電動(dòng)機(jī)：伺服電動(dòng)機(jī)可規(guī)定機(jī)構(gòu)以特定的方式運(yùn)動(dòng)，它用于引起在2個(gè)主體之間、單自由度內(nèi)的特定類型的運(yùn)動(dòng)，將位置、速度或加速度指定為時(shí)間的函數(shù)，并可控制平移或旋轉(zhuǎn)運(yùn)動(dòng)。在第四章，我們已經(jīng)完成了運(yùn)動(dòng)模型的裝配，即將動(dòng)臂，斗桿，液壓系統(tǒng)，連接片，挖斗，回轉(zhuǎn)裝置，以及挖掘機(jī)的整體按照它們應(yīng)該具備的運(yùn)動(dòng)方式連接在了一起，但是元件在組件中仍然無法移動(dòng)或旋轉(zhuǎn)，必須對連接組件的某些元件賦予“動(dòng)力”，才能做仿真運(yùn)動(dòng)。 圖422 液壓缸元件的裝配 圖423 動(dòng)臂液壓缸的裝配動(dòng)臂液壓缸主要采用滑動(dòng)桿、軸對齊、旋轉(zhuǎn)命令完成裝配，在液壓元件的裝配過程中，液壓缸底部圓孔均采用“銷釘”連接，而液壓柱頂部圓孔均采用“圓柱”連接。）簡單說明。不同的連接條件提供不同的自由度及不同的移動(dòng)機(jī)能，以使元件在機(jī)構(gòu)運(yùn)作時(shí)有正確的運(yùn)動(dòng)方式要進(jìn)行挖掘機(jī)的運(yùn)動(dòng)仿真，必須將挖掘機(jī)工作時(shí)的每個(gè)動(dòng)作分解，故使用連接方式進(jìn)行裝配更加合理，通過觀察每個(gè)零部件的自由度，運(yùn)動(dòng)方式，從而使用相應(yīng)的連接方式加以裝配，完成挖掘機(jī)的建模。以約束條件裝配固定不動(dòng)的原件:在裝配機(jī)構(gòu)的元件時(shí)，若欲裝配的原件為固定不動(dòng)的原件，則操作者直接在現(xiàn)有的組件上及欲裝配的原件上選取點(diǎn)、線、面等幾何元素，PRO/ENGINEER系統(tǒng)即會(huì)自動(dòng)給定貼合、對齊、插入等約束條件，以將原件固定在現(xiàn)有的組件上，此外，也可自行指定元件固定住的約束條件。圖412 草繪拉伸輪廓 圖413抽殼 圖414拉伸鏟斗與斗桿連接處 圖415拉伸，陣列形成鏟齒4 其余部件的建模，不再詳述，只展示最后模型圖416 液壓缸原件圖417 連接件 圖418 機(jī)倉圖419 底座 挖掘機(jī)各部分的裝配 裝配的概述完成零件設(shè)計(jì)后，將設(shè)計(jì)的零件按照設(shè)計(jì)要求裝