【導(dǎo)讀】水箱的液位控制對石油、冶金、化工等行業(yè)來說必不可少。算機(jī)技術(shù)，自動控制技術(shù)，以實現(xiàn)對水箱液位的串級控制。型進(jìn)行分析，并采用實驗建模法求取模型的傳遞函數(shù)。然后，根據(jù)被控對象模型。同時，通過對實際控制的結(jié)果進(jìn)行比較，驗證了串級控制。對提高系統(tǒng)性能的作用。隨著計算機(jī)控制技術(shù)的迅速發(fā)展，組態(tài)技術(shù)開始得到重?？刂茖ο蠛涂刂颇康娜我饨M態(tài)，完成最終的自動化控制工程。

　　

【正文】 本次設(shè)計，雖然已經(jīng)確定使用串級控制對水箱液位進(jìn)行控制，但仍通過加入切換開關(guān)控制副回路的去處和加入，可以方便的比較單回路控制和串級控制兩種方案在階躍輸入控制性能以及抗擾動 性能，明顯看出串級控制對三容水箱的液位控制優(yōu)越性。在串級液位控制仿真過程中同時可整定 PID 參數(shù)，通過不斷調(diào)節(jié)PID 參數(shù)，得到滿意的響應(yīng)曲線，使得其響應(yīng)速度快，超調(diào)量小，穩(wěn)態(tài)誤差小。 由于時間倉促，再加上本人水平有限，雖然設(shè)計基本完成，但仍有很多不足甚至錯誤之處，望各位老師能夠不吝賜教，加以斧正，謝謝！ 33 致謝 首先，我要向我的指導(dǎo)老師 —— 孫虹老師表示衷心的感謝，感謝她一個學(xué)期的耐心指導(dǎo)，使得我從對畢業(yè)設(shè)計的茫然甚至擔(dān)憂到現(xiàn)在最終獨立完成。如果沒有老師幫助我解決在設(shè)計過程中困惑，我 也很難順利完成這次畢業(yè)設(shè)計。 然后我要感謝我的母校四年來對我的教育和關(guān)懷，四年大學(xué)生活讓我學(xué)到了很多，懂得了很多。母校對我的栽培不僅讓我學(xué)會了科學(xué)知識，更重要的是幫助我學(xué)會了如何去學(xué)習(xí)，如何去把學(xué)到的知識應(yīng)用到實際的生活中，這對我畢業(yè)后的生活和工作是一筆巨大的財富。 我還要感謝我的同學(xué)，一個畢業(yè)設(shè)計中所需要了解和學(xué)會的知識有很多，一些我來不及學(xué)習(xí)的知識點通過對其熟悉的同學(xué)我才能很快的掌握。設(shè)計很多關(guān)鍵的地方我都是靠和同學(xué)的請教和討論才能順利完成，因此，同學(xué)的幫助也是我完成畢業(yè)設(shè)計的一個重要支撐。 最后我要表 達(dá)對父母的感謝，他們的勤勞和付出讓我擁有了精彩的四年大學(xué)生活，沒有他們就沒有我的今天！ 34 參考文獻(xiàn) 1. 自動控制原理，胡壽松主編，科學(xué)出版社； 2. 自動化儀表與過程控制，施仁主編，電子工業(yè)出版社； 3.《 MCGS 用戶指南》，北京昆侖通態(tài)自動化科技有限公司； 4.《 THJ2高級過程控制系統(tǒng)實驗裝置》，浙江天煌科技實業(yè)有限公司； 5. 先進(jìn) PID控制及其 MATLAB 仿真，劉金琨主編，電子工業(yè)出版社； 6. 應(yīng)用 MATLAB 建模與仿真，陳桂明，張明照等主編 ，科學(xué)出版社； 7. 控制系統(tǒng)數(shù)字仿真與 CAD，張曉華主編，哈爾濱工業(yè)大學(xué)； 8. MATLAB 工程計算， Smith . 主編，清華大學(xué)出版社； 9. MATLAB 編程， Stephen ，科學(xué)出版社； 與控制系統(tǒng)仿真實踐，趙廣元主編，北京航空航天大學(xué)出版社 ； 控制器參數(shù)整定與實現(xiàn)，黃友銳、曲立國主編，科學(xué)出版社； Overview,Fieldbus ,texas； ，劉寶坤主編，機(jī)械工業(yè)出版社； 制與計算機(jī)控制系統(tǒng)，李京主編，化學(xué)工業(yè)出版社； and Automation of technological Process and Mechatron systems, , Silesian University Publishing Company。 35 附錄：英文資料及譯文 The Integrated Circuit Digital logic and electronic circuits derive their functionality from electronic switches called transistor. Roughly speaking, the transistor can be likened to an electronically controlled valve whereby energy applied to one connection of the valve enables energy to flow between two other bini ng multiple transistors, digital logic building blocks such as AND gates and flipflops are formed. Transistors, in turn, are made from semiconductors. Consult a periodic table of elements in a college chemistry textbook, and you will locate semiconductors as a group of elements separating the metals and are called semiconductors because of their ability to behave as both metals and nonmetals. A semiconductor can be made to conduct electricity like a metal or to insulate as a nonmetal does. These differing electrical properties can be accurately controlled by mixing the semiconductor with small amounts of other elements. This mixing is called doping. A semiconductor can be doped to contain more electrons (Ntype) or fewer electrons (Ptype). Examples of monly used semiconductors are silicon and germanium. Phosphorous and boron are two elements that are used to dope Ntype and Ptype silicon, respectively. A transistor is constructed by creating a sandwich of differently doped semiconductor layers. The two most mon types of transistors, the bipolarjunction transistor (BJT) and the fieldeffect transistor (FET) are schematically illustrated in Figure figure shows both the silicon structures of these elements and their graphical symbolic representation as would be seen in a circuit diagram. The BJT shown is an NPN transistor, because it is posed of a sandwich of NPN doped silicon. When a small current is injected into the base terminal, a larger current is enabled to flow from the collector to the FET shown is an Nchannel FET, which is posed of two Ntype regions separated by a Ptype substrate. When a voltage is applied to the insulated gate terminal, a current is enabled to flow from the 36 drain to the source. It is called Nchannel, because the gate voltage induces an Nchannel within the substrate, enabling current to flow between the Nregions. Another basic semiconductor structure is a diode, which is formed simply by a junction of Ntype and Ptype silicon. Diodes act like oneway valves by conducting current only from P to N. Special diodes can be created that emit light when a voltage is applied. Appropriately enough, these ponents are called light emitting diodes, or LEDs. These small lights are manufactured by the millions and are found in diverse applications from telephones to traffic lights. The resulting small chip of semiconductor material on which a transistor or diode is fabricated can be encased in a small plastic package for protection agai nst damage and contamination from the out side wires are connected within this package between the semiconductor sandwich and pins that protrude from the package to make electrical contact with other parts of the intended circuit. Once you have several discrete transistors, digital logic can be built by directly wiring these ponents together. The circuit will function, but any substantial amount of digital logic will be very bulky, because several transistors are required to implement each of the various types of logic gates. At the time of the invention of the transistor in 1947 by John Bardeen, Walter Brattain, and William Shockley, the only way to assemble multiple transistors into a single circuit was to buy separate discrete transistors and wire them together. In 1959, Jack Kilby and Robert Noyce independently invented a means of fabricating multiple transistors on a single slab of semiconductor material. Their invention would e to be known as the integrated circuit, or IC, which is the foundation of our modern puterized world. An IC is so called because it integrates multiple transistors and diodes onto the same small semiconductor chip. Instead of having to solder individual wires between discrete ponents, an IC contains many small ponents that are already wired together in the desired topology to form a circuit. A typical IC, without its plastic or ceramic package, is a square or rectangular silicon die measuring from 2 to 15 mm on an edge. Depending on the level of technology used to manufacture the IC, there may be anywhere from a dozen to tens 37