反(fan)應(ying)(ying)釜是化工生產過(guo)程(cheng)中的(de)(de)(de)重(zhong)要設備,反(fan)應(ying)(ying)過(guo)程(cheng)中伴隨(sui)有(you)大(da)(da)量的(de)(de)(de)吸、放熱現象,具(ju)有(you)大(da)(da)滯后、時變、非線(xian)性、反(fan)應(ying)(ying)機理復雜等(deng)特點。傳統(tong)(tong)的(de)(de)(de)PID控(kong)制是一種基(ji)于過(guo)程(cheng)參數(shu)的(de)(de)(de)控(kong)制方法(fa)(fa),具(ju)有(you) 控(kong)制原(yuan)理簡單(dan)、穩定(ding)性好、可靠(kao)性高、參數(shu)易(yi)調整(zheng)等(deng)優點,但其設計依賴(lai)于被控(kong)對象的(de)(de)(de)精確數(shu)學模型(xing),在(zai)線(xian)整(zheng)定(ding)參數(shu)的(de)(de)(de)能力差(cha),而反(fan)應(ying)(ying)釜因為機理復雜、各個參數(shu)在(zai) 系統(tong)(tong)反(fan)應(ying)(ying)過(guo)程(cheng)中時變,不能建立精確的(de)(de)(de)數(shu)學模型(xing),不能滿(man)足系統(tong)(tong)在(zai)不同條件下對參數(shu)自整(zheng)定(ding)的(de)(de)(de)要求,因而采用(yong)一般的(de)(de)(de)PID控(kong)制器無法(fa)(fa)實現對反(fan)應(ying)(ying)釜的(de)(de)(de)精確控(kong)制。
模(mo)糊控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)是(shi)一種基于(yu)規(gui)則(ze)的語言控(kong)(kong)制(zhi)(zhi)(zhi)(zhi),在設計中不(bu)需要(yao)建(jian)立被控(kong)(kong)對象的精確數學模(mo)型,魯(lu)棒性強,干擾(rao)和參數變化(hua)對控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)效(xiao)果(guo)的影響被大大減弱,摔制(zhi)(zhi)(zhi)(zhi)效(xiao)果(guo)好。但(dan)模(mo)糊控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)器是(shi)以誤差(cha)和誤差(cha)變化(hua)作為輸(shu)入變量,這(zhe)種控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)器具有模(mo)糊比例(li)-微(wei)分控(kong)(kong)制(zhi)(zhi)(zhi)(zhi)作用,精度不(bu)太高、穩態誤差(cha)較(jiao)大、自適應(ying)能力有限(xian)和易產生振(zhen)蕩現象。
預(yu)測控(kong)(kong)(kong)制是一種優(you)化(hua)控(kong)(kong)(kong)制算法(fa),它是通過對(dui)某(mou)一性能指標的(de)(de)最(zui)優(you)來(lai)確定(ding)未(wei)來(lai)的(de)(de)控(kong)(kong)(kong)制作用(yong)的(de)(de),具有(you)對(dui)模(mo)型(xing)要求低、魯棒(bang)性好、適用(yong)于(yu)數字計算機(ji)控(kong)(kong)(kong)制的(de)(de)優(you)點。由于(yu)計算機(ji)模(mo)型(xing)預(yu) 測控(kong)(kong)(kong)制具有(you)良好的(de)(de)跟蹤性能,能有(you)效地提高系統(tong)的(de)(de)穩定(ding)性和消除誤差,對(dui)滯后過程有(you)明顯控(kong)(kong)(kong)制效果(guo),更加符(fu)合工業溫(wen)(wen)(wen)(wen)度(du)(du)控(kong)(kong)(kong)制的(de)(de)實際要求,從(cong)而大大提高了(le)溫(wen)(wen)(wen)(wen)度(du)(du)控(kong)(kong)(kong)制系 統(tong)的(de)(de)性能。分析反應(ying)釜(fu)溫(wen)(wen)(wen)(wen)度(du)(du)變化(hua)的(de)(de)特(te)點以及(ji)控(kong)(kong)(kong)制難點,總結(jie)當(dang)前溫(wen)(wen)(wen)(wen)度(du)(du)控(kong)(kong)(kong)制系統(tong)精度(du)(du)差的(de)(de)根本原因,在此(ci)基礎上(shang)采用(yong)基于(yu)預(yu)測的(de)(de)模(mo)糊自整定(ding)PID集成控(kong)(kong)(kong)制技術實現反應(ying)釜(fu)溫(wen)(wen)(wen)(wen)度(du)(du)控(kong)(kong)(kong)制,其(qi)主要思想是利用(yong)系統(tong)模(mo)型(xing)的(de)(de)預(yu)測輸(shu)出,結(jie)合常規PID的(de)(de)控(kong)(kong)(kong)制經驗(yan),采用(yong)模(mo)糊推理方法(fa),對(dui)控(kong)(kong)(kong)制器算法(fa)進行改進。
實驗(yan)(yan)結果表明(ming),與(yu)通常的(de)(de)PID 控制方(fang)(fang)案相比,該(gai)方(fang)(fang)案提高(gao)(gao)了系統(tong)的(de)(de)魯棒性(xing)(xing)和適應(ying)性(xing)(xing),較(jiao)好(hao)的(de)(de)解決了反(fan)應(ying)釜(fu)溫度(du)控制的(de)(de)難題。完成了反(fan)應(ying)釜(fu)溫度(du)控制系統(tong)的(de)(de)硬(ying)件(jian)電路的(de)(de)設計、系統(tong)軟件(jian)的(de)(de)編譯與(yu)調 試(shi),對基(ji)于(yu)預測的(de)(de)模(mo)糊自整定(ding)PID溫度(du)控制系統(tong)進(jin)行了仿真與(yu)實驗(yan)(yan)研究,與(yu)PIU控制方(fang)(fang)法相比,控制性(xing)(xing)能更(geng)加穩定(ding),可靠性(xing)(xing)更(geng)高(gao)(gao),實時性(xing)(xing)、適應(ying)性(xing)(xing)、魯棒性(xing)(xing)都顯 著增強,控制效(xiao)果較(jiao)好(hao)。
