實驗名稱：驅動器驅動特性測試

　　測試目的：針(zhen)對球(qiu)囊(nang)(nang)形DEA的(de)結構特(te)點和驅(qu)(qu)動(dong)(dong)(dong)要求搭建了(le)測試平臺。通(tong)過(guo)(guo)MATLAB軟件控制高壓(ya)(ya)放大器(qi)(qi)對球(qiu)囊(nang)(nang)型DEA加電(dian)驅(qu)(qu)動(dong)(dong)(dong)，使(shi)用(yong)氣(qi)(qi)壓(ya)(ya)傳(chuan)感(gan)器(qi)(qi)記(ji)錄驅(qu)(qu)動(dong)(dong)(dong)器(qi)(qi)DE球(qiu)囊(nang)(nang)內部的(de)氣(qi)(qi)壓(ya)(ya)變(bian)化；作(zuo)為(wei)錨(mao)固結構，驅(qu)(qu)動(dong)(dong)(dong)狀(zhuang)態(tai)下的(de)球(qiu)囊(nang)(nang)尺寸是重點關注的(de)性能參數，使(shi)用(yong)AVT工業(ye)相機記(ji)錄試驗(yan)過(guo)(guo)程并得到各階段的(de)球(qiu)囊(nang)(nang)最大半(ban)徑(jing)。通(tong)過(guo)(guo)測試得到了(le)球(qiu)囊(nang)(nang)形DEA的(de)臨界電(dian)壓(ya)(ya)，研究了(le)加電(dian)電(dian)壓(ya)(ya)、初始氣(qi)(qi)壓(ya)(ya)作(zuo)為(wei)單一變(bian)量時驅(qu)(qu)動(dong)(dong)(dong)器(qi)(qi)球(qiu)囊(nang)(nang)最大半(ban)徑(jing)的(de)變(bian)化規律，驗(yan)證外接氣(qi)(qi)腔時對驅(qu)(qu)動(dong)(dong)(dong)器(qi)(qi)球(qiu)囊(nang)(nang)穩壓(ya)(ya)供氣(qi)(qi)、提升(sheng)變(bian)形量的(de)作(zuo)用(yong)，并總結出較為(wei)理想的(de)氣(qi)(qi)壓(ya)(ya)-電(dian)壓(ya)(ya)匹配關系。

　　測試設備：高壓放大器、氣壓傳感器、信(xin)號(hao)采集(ji)卡、工業(ye)相機(ji)、計(ji)算機(ji)等。

　　圖1：驅動器測(ce)試平臺示意圖

　　實驗過程：

　　驅(qu)(qu)動(dong)(dong)器(qi)(qi)測(ce)(ce)試平臺(tai)如圖1所(suo)示(shi)，主要(yao)由電(dian)壓(ya)調控、氣(qi)壓(ya)測(ce)(ce)量、球(qiu)囊變形(xing)測(ce)(ce)量等(deng)部分(fen)(fen)構成。將驅(qu)(qu)動(dong)(dong)器(qi)(qi)樣品平放(fang)在由立柱支撐的(de)測(ce)(ce)試平面上，鋁箔電(dian)極與高(gao)壓(ya)放(fang)大器(qi)(qi)的(de)電(dian)壓(ya)輸(shu)出端連接(jie)，驅(qu)(qu)動(dong)(dong)器(qi)(qi)底部連接(jie)軟(ruan)(ruan)氣(qi)管至三(san)通(tong)(tong)氣(qi)閥處；三(san)通(tong)(tong)氣(qi)閥另外(wai)兩(liang)個出口分(fen)(fen)別連接(jie)氣(qi)壓(ya)傳(chuan)感(gan)(gan)器(qi)(qi)與單向閥，通(tong)(tong)過單向閥可以給驅(qu)(qu)動(dong)(dong)器(qi)(qi)充入氣(qi)體同(tong)時防止氣(qi)體泄漏。將工業相機設(she)置(zhi)于(yu)驅(qu)(qu)動(dong)(dong)器(qi)(qi)正(zheng)上方(fang)，記錄試驗過程(cheng)中球(qiu)囊的(de)形(xing)變情(qing)況，為了(le)提高(gao)成像質量使用了(le)照明(ming)設(she)備。計(ji)算(suan)機連接(jie)信號(hao)(hao)采集卡，一(yi)方(fang)面用于(yu)控制(zhi)高(gao)壓(ya)放(fang)大器(qi)(qi)的(de)輸(shu)出電(dian)壓(ya)，另一(yi)方(fang)面收集氣(qi)壓(ya)傳(chuan)感(gan)(gan)器(qi)(qi)、高(gao)壓(ya)放(fang)大器(qi)(qi)等(deng)輸(shu)出的(de)信號(hao)(hao)，匯總的(de)試驗數據通(tong)(tong)過計(ji)算(suan)機軟(ruan)(ruan)件進行分(fen)(fen)析。

　　介電(dian)(dian)(dian)(dian)彈(dan)性體(ti)材料的(de)(de)電(dian)(dian)(dian)(dian)學特(te)性通(tong)常要求上千伏外界電(dian)(dian)(dian)(dian)壓(ya)(ya)激發(fa)，普通(tong)的(de)(de)電(dian)(dian)(dian)(dian)源發(fa)生(sheng)器無法滿足(zu)要求。采用(yong)了(le)高壓(ya)(ya)功率(lv)放大(da)器，通(tong)過計算機可(ke)以控(kong)(kong)制該高壓(ya)(ya)放大(da)器輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)大(da)小、波形等參數，輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)可(ke)達5kV(DC)或相應峰(feng)值AC，并可(ke)以遠(yuan)程(cheng)控(kong)(kong)制電(dian)(dian)(dian)(dian)源通(tong)斷(duan)確保試(shi)驗安全進行；此外該高壓(ya)(ya)放大(da)器還(huan)具(ju)有測量功能，能實時(shi)(shi)檢測并記(ji)錄電(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)壓(ya)(ya)變(bian)化，并通(tong)過信(xin)(xin)號采集(ji)卡上傳(chuan)至計算機。使用(yong)了(le)Matlab軟件對(dui)試(shi)驗過程(cheng)進行控(kong)(kong)制，Matlab可(ke)以對(dui)高壓(ya)(ya)放大(da)器施加命令流，控(kong)(kong)制其根(gen)據給(gei)定時(shi)(shi)間(jian)通(tong)斷(duan)電(dian)(dian)(dian)(dian)；通(tong)過Matlab還(huan)可(ke)以讀取信(xin)(xin)號采集(ji)卡傳(chuan)輸的(de)(de)電(dian)(dian)(dian)(dian)信(xin)(xin)號，繪制時(shi)(shi)間(jian)、電(dian)(dian)(dian)(dian)壓(ya)(ya)、電(dian)(dian)(dian)(dian)流三者之間(jian)的(de)(de)關系曲線，分析驅(qu)動(dong)器加電(dian)(dian)(dian)(dian)過程(cheng)中的(de)(de)電(dian)(dian)(dian)(dian)學特(te)性。

　　由于驅動器(qi)被設計為(wei)密封(feng)氣(qi)(qi)(qi)囊(nang)，理想狀態(tai)下裝置(zhi)內部氣(qi)(qi)(qi)體(ti)總量可(ke)視為(wei)不變(bian)，根(gen)據理想狀態(tai)氣(qi)(qi)(qi)體(ti)方程：PV=nRT，可(ke)知恒(heng)溫下氣(qi)(qi)(qi)壓(ya)變(bian)化(hua)與體(ti)積變(bian)化(hua)呈相反(fan)關系，則(ze)氣(qi)(qi)(qi)壓(ya)變(bian)化(hua)可(ke)以用來反(fan)映球囊(nang)體(ti)積變(bian)化(hua)。因(yin)此，氣(qi)(qi)(qi)壓(ya)變(bian)化(hua)也(ye)是試(shi)驗的重要(yao)參數之一(yi)。

　　圖2：氣壓測(ce)量設備(a)氣壓傳感器(b)氣壓傳感器電源(yuan)

　　選(xuan)用(yong)了壓力傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)器(qi)，如(ru)圖(tu)2(a)所示(shi)。該(gai)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)器(qi)電(dian)(dian)源供應(ying)為(wei)直流5V，采用(yong)圖(tu)2(b)中的(de)(de)(de)小型電(dian)(dian)源進(jin)行供電(dian)(dian)。按照產品說明書(shu)進(jin)行了電(dian)(dian)源線(xian)(xian)(xian)、信號(hao)線(xian)(xian)(xian)的(de)(de)(de)接線(xian)(xian)(xian)，信號(hao)線(xian)(xian)(xian)連接至(zhi)信號(hao)采集(ji)卡將氣(qi)壓傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)器(qi)采集(ji)到的(de)(de)(de)信號(hao)轉換并(bing)輸送給計(ji)算機。該(gai)傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)器(qi)量程為(wei)±5PSI（即±34.475kPa），測(ce)量誤差(cha)為(wei)±0.01kPa，量程與精(jing)度都(dou)滿足試(shi)驗(yan)要求。該(gai)氣(qi)壓傳(chuan)(chuan)(chuan)感(gan)(gan)(gan)器(qi)測(ce)量值(zhi)為(wei)兩端口(kou)的(de)(de)(de)氣(qi)壓差(cha)，試(shi)驗(yan)過程中僅使用(yong)一個(ge)端口(kou)即可，得(de)到的(de)(de)(de)氣(qi)壓值(zhi)即為(wei)大氣(qi)壓與球囊內(nei)部(bu)氣(qi)壓的(de)(de)(de)差(cha)值(zhi)。

　　實驗結果：

　　圖3：AVT工業相機

　　氣(qi)壓變(bian)化可以反應出總體積變(bian)化，但還需要測量加電前后驅動器(qi)球囊的半徑變(bian)化作為驅動器(qi)錨(mao)定性(xing)能的參考。采用了(le)AVT工業相機從俯視方向記錄試驗加電過程，如圖3所示。使用軟件對相機拍攝(she)進行編程控(kong)制，在高壓放大器(qi)開始(shi)加電的同時開始(shi)拍攝(she)，斷電后2s結束拍攝(she)。

　　對采集(ji)到的(de)試(shi)驗圖(tu)(tu)像(xiang)(xiang)(xiang)進行(xing)處(chu)理：首先選(xuan)取(qu)加(jia)(jia)電前和加(jia)(jia)電后(hou)穩定狀態(tai)的(de)球(qiu)囊(nang)(nang)(nang)(nang)圖(tu)(tu)像(xiang)(xiang)(xiang)，利用PhotoShop軟(ruan)件(jian)進行(xing)批處(chu)理截(jie)取(qu)出相同位置和尺寸的(de)圖(tu)(tu)片(pian)，要求包括(kuo)清晰的(de)整個球(qiu)囊(nang)(nang)(nang)(nang)形(xing)貌；然(ran)后(hou)使(shi)用ImageJ軟(ruan)件(jian)對圖(tu)(tu)像(xiang)(xiang)(xiang)進行(xing)二值(zhi)化(hua)處(chu)理，讓球(qiu)囊(nang)(nang)(nang)(nang)邊(bian)(bian)緣與(yu)非球(qiu)囊(nang)(nang)(nang)(nang)部分形(xing)成明顯(xian)的(de)灰(hui)度(du)對比(bi)，使(shi)用工具選(xuan)取(qu)球(qiu)囊(nang)(nang)(nang)(nang)邊(bian)(bian)界(jie)區(qu)域，如圖(tu)(tu)4所(suo)示(shi)；利用ImageJ的(de)灰(hui)度(du)統計(ji)功能可(ke)以計(ji)算出黃(huang)色(se)線包圍區(qu)域的(de)像(xiang)(xiang)(xiang)素(su)點總數(shu)，隨后(hou)與(yu)中(zhong)(zhong)心磁(ci)片(pian)區(qu)域的(de)像(xiang)(xiang)(xiang)素(su)點總數(shu)對比(bi)，即可(ke)得到球(qiu)囊(nang)(nang)(nang)(nang)面積與(yu)中(zhong)(zhong)心磁(ci)片(pian)面積的(de)比(bi)值(zhi)關系。已知磁(ci)片(pian)的(de)實際(ji)面積為16πmm2，可(ke)以輕松(song)推(tui)算出球(qiu)囊(nang)(nang)(nang)(nang)的(de)實際(ji)面積大小(xiao)，進而(er)得到球(qiu)囊(nang)(nang)(nang)(nang)半(ban)徑(jing)的(de)估測值(zhi)。

　　高壓放大(da)器(qi)推薦(jian)：ATA-7050

　　圖：ATA-7050高壓放大器指標參數

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