實驗名稱：直(zhi)升機機身的多(duo)諧波多(duo)輸(shu)入多(duo)輸(shu)出振動(dong)主動(dong)控制試(shi)驗研究

　　實驗原理：首(shou)先采用一個(ge)由Z-11直升機(ji)地板模(mo)型(xing)縮比而(er)來并且與Z-11直升機(ji)動(dong)(dong)力學(xue)相(xiang)似的(de)(de)框(kuang)架模(mo)型(xing)作為(wei)研究對象(xiang)，將壓(ya)電(dian)疊層(ceng)作動(dong)(dong)器整合(he)到受控結構中，通過(guo)數字信號處理器作為(wei)試(shi)驗(yan)系統(tong)的(de)(de)控制(zhi)(zhi)器，整合(he)搭(da)建(jian)了壓(ya)電(dian)疊層(ceng)作動(dong)(dong)器驅(qu)動(dong)(dong)的(de)(de)直升機(ji)機(ji)身(shen)多諧(xie)波(bo)多輸(shu)入多輸(shu)出振動(dong)(dong)主動(dong)(dong)控制(zhi)(zhi)試(shi)驗(yan)系統(tong)，并且離線測量了搭(da)建(jian)好的(de)(de)試(shi)驗(yan)系統(tong)的(de)(de)控制(zhi)(zhi)通道(dao)傳遞函數。

　　試(shi)驗(yan)(yan)(yan)系統中，采(cai)用一(yi)個框架試(shi)驗(yan)(yan)(yan)模(mo)型(xing)模(mo)擬Z-11直升(sheng)機座艙用來進行振動主(zhu)動控制試(shi)驗(yan)(yan)(yan)，其材料選(xuan)用45號鋼(gang)，總質量為15.7kg。加工完(wan)成的框架試(shi)驗(yan)(yan)(yan)模(mo)型(xing)如圖a所示(shi)。

　　圖a直升(sheng)機地板框架實驗模(mo)型

　　壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)通(tong)過(guo)兩端的(de)內螺紋與外(wai)部結構相連(lian)，壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)不能承受拉(la)力(li)和彎矩，否則壓(ya)(ya)(ya)電(dian)薄(bo)片之間的(de)連(lian)接會發生(sheng)脆性斷(duan)裂從而導致壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)損壞失效。因此在(zai)實際使(shi)用(yong)中，為了(le)避免拉(la)力(li)，安(an)裝(zhuang)(zhuang)壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)時會在(zai)兩端施(shi)加一定(ding)的(de)預(yu)緊(jin)力(li)，并且避免使(shi)用(yong)負電(dian)壓(ya)(ya)(ya)驅(qu)動(dong)(dong)壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)；為了(le)避免壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)承彎，在(zai)安(an)裝(zhuang)(zhuang)壓(ya)(ya)(ya)電(dian)疊(die)(die)層(ceng)作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)時將一個彈(dan)性較與作(zuo)(zuo)(zuo)動(dong)(dong)器(qi)(qi)并聯安(an)裝(zhuang)(zhuang)，安(an)裝(zhuang)(zhuang)形式如圖(tu)b所示。

　　圖b壓電疊層作動(dong)器安裝形(xing)式(shi)

　　圖(tu)c實驗(yan)系(xi)統原理框圖(tu)

　　測試設備：信(xin)號(hao)發生器、ATA-P0102功率放大器、壓電疊(die)堆、DSP、信(xin)號(hao)調理模塊、計算(suan)機

　　實驗過程：DSP內部的(de)信(xin)號(hao)(hao)(hao)(hao)發生(sheng)(sheng)器(qi)生(sheng)(sheng)成數字激勵信(xin)號(hao)(hao)(hao)(hao)通(tong)(tong)過(guo)D/A轉換為(wei)模擬信(xin)號(hao)(hao)(hao)(hao)，然(ran)后(hou)通(tong)(tong)過(guo)低通(tong)(tong)濾波(bo)(bo)和功(gong)率放(fang)(fang)(fang)大(da)器(qi)放(fang)(fang)(fang)大(da)后(hou)輸(shu)入(ru)(ru)到(dao)(dao)電磁激振(zhen)器(qi)對(dui)框(kuang)架結構產生(sheng)(sheng)激勵響(xiang)應(ying)，模擬旋翼在(zai)直升機座(zuo)艙地板產生(sheng)(sheng)的(de)振(zhen)動(dong)(dong)響(xiang)應(ying)。加速度(du)傳感器(qi)采(cai)集待減振(zhen)點處的(de)加速度(du)響(xiang)應(ying)，并(bing)轉化為(wei)相應(ying)的(de)電信(xin)號(hao)(hao)(hao)(hao)，再由(you)A/D采(cai)樣(yang)得(de)到(dao)(dao)數字信(xin)號(hao)(hao)(hao)(hao)。采(cai)集到(dao)(dao)的(de)數字信(xin)號(hao)(hao)(hao)(hao)代入(ru)(ru)控制算(suan)法(fa)用來(lai)修正得(de)到(dao)(dao)壓電疊(die)層作動(dong)(dong)器(qi)的(de)驅動(dong)(dong)信(xin)號(hao)(hao)(hao)(hao)，驅動(dong)(dong)信(xin)號(hao)(hao)(hao)(hao)通(tong)(tong)過(guo)D/A轉換后(hou)經過(guo)低通(tong)(tong)濾波(bo)(bo)器(qi)和功(gong)率放(fang)(fang)(fang)大(da)器(qi)輸(shu)入(ru)(ru)到(dao)(dao)壓電疊(die)層作動(dong)(dong)器(qi)，驅動(dong)(dong)結構產生(sheng)(sheng)作動(dong)(dong)響(xiang)應(ying)來(lai)抵消激勵響(xiang)應(ying)。同時，通(tong)(tong)過(guo)串口將誤差響(xiang)應(ying)信(xin)號(hao)(hao)(hao)(hao)與(yu)作動(dong)(dong)器(qi)驅動(dong)(dong)信(xin)號(hao)(hao)(hao)(hao)實時發送(song)給計算(suan)機進行(xing)存(cun)儲。

　　多(duo)諧波多(duo)輸(shu)入(ru)多(duo)輸(shu)出(chu)前(qian)饋(kui)自適應(ying)控制(zhi)(zhi)(zhi)(zhi)(zhi)算(suan)(suan)法需(xu)要準(zhun)確的(de)控制(zhi)(zhi)(zhi)(zhi)(zhi)通(tong)道(dao)的(de)傳遞函數(shu)(shu)(shu)(shu)(shu)來保(bao)證控制(zhi)(zhi)(zhi)(zhi)(zhi)算(suan)(suan)法的(de)收(shou)斂(lian)。本實驗(yan)(yan)通(tong)過識別離線測(ce)量(liang)(liang)的(de)方法，采集并(bing)計算(suan)(suan)得到了(le)直升機(ji)機(ji)身(shen)振動(dong)(dong)(dong)主動(dong)(dong)(dong)控制(zhi)(zhi)(zhi)(zhi)(zhi)試(shi)驗(yan)(yan)系統(tong)的(de)控制(zhi)(zhi)(zhi)(zhi)(zhi)通(tong)道(dao)傳遞函數(shu)(shu)(shu)(shu)(shu)，測(ce)量(liang)(liang)試(shi)驗(yan)(yan)的(de)原(yuan)理圖(tu)如圖(tu)c所示。數(shu)(shu)(shu)(shu)(shu)字信(xin)(xin)(xin)號(hao)發(fa)生(sheng)(sheng)器(qi)產生(sheng)(sheng)正弦激勵(li)信(xin)(xin)(xin)號(hao)，經過D/A轉(zhuan)(zhuan)(zhuan)換(huan)和(he)低(di)通(tong)濾(lv)波后(hou)，再(zai)經過功率放(fang)大(da)(da)驅(qu)動(dong)(dong)(dong)壓電疊層(ceng)作(zuo)(zuo)動(dong)(dong)(dong)器(qi)對(dui)(dui)框(kuang)架(jia)施加(jia)作(zuo)(zuo)動(dong)(dong)(dong)力。作(zuo)(zuo)動(dong)(dong)(dong)力在(zai)待(dai)減(jian)振點(dian)處(chu)產生(sheng)(sheng)作(zuo)(zuo)動(dong)(dong)(dong)響(xiang)應(ying)，并(bing)由安裝在(zai)待(dai)減(jian)振點(dian)的(de)加(jia)速(su)(su)(su)度(du)傳感(gan)器(qi)測(ce)量(liang)(liang)。測(ce)量(liang)(liang)的(de)加(jia)速(su)(su)(su)度(du)信(xin)(xin)(xin)號(hao)經過低(di)通(tong)濾(lv)波和(he)A/D轉(zhuan)(zhuan)(zhuan)換(huan)后(hou)得到數(shu)(shu)(shu)(shu)(shu)字信(xin)(xin)(xin)號(hao)，與激勵(li)信(xin)(xin)(xin)號(hao)一(yi)起通(tong)過串口(kou)實時傳送到計算(suan)(suan)機(ji)上。計算(suan)(suan)機(ji)對(dui)(dui)數(shu)(shu)(shu)(shu)(shu)據進行抓包和(he)解碼(ma)處(chu)理后(hou)，計算(suan)(suan)加(jia)速(su)(su)(su)度(du)信(xin)(xin)(xin)號(hao)和(he)激勵(li)信(xin)(xin)(xin)號(hao)的(de)幅值比和(he)相位差，即可(ke)得到控制(zhi)(zhi)(zhi)(zhi)(zhi)通(tong)道(dao)的(de)傳遞函數(shu)(shu)(shu)(shu)(shu)。試(shi)驗(yan)(yan)中，采樣頻率設(she)為f=975Hz，激勵(li)信(xin)(xin)(xin)號(hao)頻率參考Z-11型直升機(ji)，分別測(ce)量(liang)(liang)了(le)19.5Hz和(he)39Hz的(de)控制(zhi)(zhi)(zhi)(zhi)(zhi)通(tong)道(dao)傳遞函數(shu)(shu)(shu)(shu)(shu)，結(jie)果如表1和(he)表2所示。需(xu)要指出(chu)的(de)是,控制(zhi)(zhi)(zhi)(zhi)(zhi)通(tong)道(dao)的(de)傳遞函數(shu)(shu)(shu)(shu)(shu)除了(le)作(zuo)(zuo)動(dong)(dong)(dong)器(qi)和(he)試(shi)驗(yan)(yan)框(kuang)架(jia)模(mo)型的(de)動(dong)(dong)(dong)態特(te)性，還(huan)包括了(le)功率放(fang)大(da)(da)器(qi)放(fang)大(da)(da)倍(bei)數(shu)(shu)(shu)(shu)(shu)、傳感(gan)器(qi)的(de)靈敏度(du)以及A/D轉(zhuan)(zhuan)(zhuan)換(huan)和(he)D/A轉(zhuan)(zhuan)(zhuan)換(huan)的(de)精度(du)。

　　表119.5Hz控制通道(dao)傳遞(di)函數

　　表239Hz控制通道傳遞(di)函數

　　實驗結果：根據(ju)Z-11直升(sheng)機機身上實測的(de)(de)(de)(de)振(zhen)(zhen)動(dong)(dong)響應信號(hao)，單諧波(bo)激(ji)(ji)(ji)勵(li)(li)(li)的(de)(de)(de)(de)頻率(lv)選取(qu)為第一階槳葉通(tong)過頻率(lv)ω1=NbΩ=19.5Hz。Z-11直升(sheng)機機身振(zhen)(zhen)動(dong)(dong)的(de)(de)(de)(de)一階通(tong)過頻率(lv)加速(su)度響應為0.95m/s，為了(le)使兩個(ge)待(dai)減振(zhen)(zhen)點在無控制時(shi)的(de)(de)(de)(de)振(zhen)(zhen)動(dong)(dong)加速(su)度水平與Z-11直升(sheng)機相同，設置激(ji)(ji)(ji)勵(li)(li)(li)信號(hao)的(de)(de)(de)(de)幅值為Xe(t)=1.465×sin(2πω1t)。激(ji)(ji)(ji)勵(li)(li)(li)信號(hao)經過放大(da)后驅(qu)動(dong)(dong)電(dian)磁激(ji)(ji)(ji)振(zhen)(zhen)器(qi)對(dui)框架試(shi)驗模型的(de)(de)(de)(de)激(ji)(ji)(ji)勵(li)(li)(li)點1進(jin)行(xing)激(ji)(ji)(ji)勵(li)(li)(li)，激(ji)(ji)(ji)振(zhen)(zhen)力沿Z方向(xiang)，激(ji)(ji)(ji)振(zhen)(zhen)點位于框架結構的(de)(de)(de)(de)中(zhong)性線上，此(ci)時(shi)框架試(shi)驗模型僅垂向(xiang)彎(wan)曲模態的(de)(de)(de)(de)振(zhen)(zhen)動(dong)(dong)被(bei)激(ji)(ji)(ji)發。試(shi)驗研究(jiu)中(zhong)，采樣頻率(lv)為fs=975Hz，控制算(suan)法的(de)(de)(de)(de)諧波(bo)系(xi)(xi)(xi)數(shu)識別收斂(lian)系(xi)(xi)(xi)數(shu)取(qu)?1=0.03，歸一化LMS算(suan)法的(de)(de)(de)(de)收斂(lian)系(xi)(xi)(xi)數(shu)取(qu)?0=0.001。別的(de)(de)(de)(de)諧波(bo)系(xi)(xi)(xi)數(shu)向(xiang)量初始值均為0。兩個(ge)減振(zhen)(zhen)點的(de)(de)(de)(de)垂向(xiang)加速(su)度響應如(ru)(ru)圖d和圖e所(suo)示，四個(ge)壓電(dian)疊(die)層作動(dong)(dong)器(qi)的(de)(de)(de)(de)驅(qu)動(dong)(dong)電(dian)壓如(ru)(ru)圖f到圖i所(suo)示。可以看(kan)出，振(zhen)(zhen)動(dong)(dong)主動(dong)(dong)控制系(xi)(xi)(xi)統開始從10秒(miao)啟(qi)動(dong)(dong)后，兩個(ge)待(dai)減振(zhen)(zhen)點的(de)(de)(de)(de)振(zhen)(zhen)動(dong)(dong)隨之衰減,并在10秒(miao)內逐漸收斂(lian)到穩定狀態。穩定控制狀態下，兩個(ge)減振(zhen)(zhen)點的(de)(de)(de)(de)振(zhen)(zhen)動(dong)(dong)響應分別降低了(le)97%和98%。

　　圖d單諧波(bo)對稱激勵試驗(yan)待(dai)減振點1的垂向加速度(du)響(xiang)應(ying)

　　圖e單諧(xie)波對稱激勵試(shi)驗待減振點2的垂向加(jia)速度響應

　　圖(tu)f單諧波對(dui)稱(cheng)激勵(li)試驗壓(ya)電(dian)疊堆作動器1的驅動電(dian)壓(ya)

　　圖g單諧波(bo)對稱激(ji)勵試驗壓(ya)電(dian)疊堆作動器2的驅(qu)動電(dian)壓(ya)

　　圖h單諧波(bo)對稱激勵試驗(yan)壓(ya)電(dian)疊堆作(zuo)動(dong)(dong)器3的驅動(dong)(dong)電(dian)壓(ya)

　　圖i單(dan)諧波對稱激(ji)勵試驗(yan)壓(ya)(ya)電疊堆(dui)作動器(qi)3的驅動電壓(ya)(ya)

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