【正文】 控技術(shù)的發(fā)展與現(xiàn)狀 近年來，溫度的檢測(cè)在理論上發(fā)展比較成熟，但在實(shí)際測(cè)量和控制中，如何保證快速實(shí)時(shí)地對(duì)溫度進(jìn)行采樣，確保數(shù)據(jù)的正確傳輸，并能對(duì)所測(cè)溫度場(chǎng)進(jìn)行較精確的控制，仍然是目前需要解決的問題。 鑒于上述這些特點(diǎn)，高精度溫度控制的難度比較大，而且不同的應(yīng)用環(huán)境也需要不同的控制策略。這是因?yàn)楹芏鄳?yīng)用中只有加熱環(huán)節(jié)，而沒有冷卻的裝置。因此，對(duì)溫度的控制精度要求比較高的情況下，是不允許出現(xiàn)過沖現(xiàn)象的，即不允許實(shí)際溫度超過控制的目標(biāo)溫度。根據(jù)熱力學(xué)第二定律，兩個(gè)溫度相同的系統(tǒng)之間是達(dá)到熱平衡的，這樣利用一個(gè)與目標(biāo)系統(tǒng)溫度同步的隔離層，就可以把目標(biāo)系統(tǒng)與外界進(jìn)行熱隔離 [1]。 在實(shí)際的生產(chǎn)實(shí)驗(yàn)環(huán)境下，由于系統(tǒng)內(nèi)部與外界的熱交換是難以控制的，其他熱源的干擾也是無法精確計(jì)算的，因此溫度量的變化往往受到不可預(yù)測(cè)的外界環(huán)境擾動(dòng)的影響。在很多生產(chǎn)過程中，溫度的測(cè)量和控制都直接和安全生產(chǎn)、提高生產(chǎn)效率、保證產(chǎn)品質(zhì)量、節(jié)約能源等重大技術(shù)經(jīng)濟(jì)指標(biāo)相聯(lián)系。 關(guān)鍵詞 單片機(jī) ； 溫度控制 ； 數(shù)字 PID控制 II Abstract Along with national economy development, the people need to each heating furnace， the temperature carry on the monitor and the control. Not only uses the monolithic integrated circuit to e to them to control has the control to be convenient, simple and flexibility big and so on merits, moreover may enhance large scale is accused the temperature technical specification, thus can big enhance the product the quality and quantity. PID temperature control, as an important control device, has been widely used in producing chemical products, foods and many other fields. The paper mainly introduces based on a temperature control system. The hardware and software of the temperature control system and the design of relevant interface circuit are described in this paper. The reliability of the system is specially considered, and a series of measures are realized. According to the difficulty to control of the system, methods of system control are analyzed based on the system Identification, and realized the control algorithm in the Microcontroller system. The experiment data shows that the design of temperature control system based on Microcontroller is availability and rationality. Key words Microcontroller ； Temperature control system； Digital PID control 目 錄 摘 要 ........................................................................................................................ I Abstract ....................................................................................................................... II 第一章 緒論 ........................................................................................................... 1 概述 ................................................................................................................................................ 1 溫度測(cè)控技術(shù)的發(fā)展與現(xiàn)狀 ............................................................................................ 1 定值開關(guān)控溫法 ................................................................................................................... 2 PID 線性控溫法 ................................................................................................................... 2 智能溫度控制法 ................................................................................................................... 3 系統(tǒng)總體設(shè)計(jì)方案 ................................................................................................................. 3 系統(tǒng)性能要求及特點(diǎn) .......................................................................................................... 4 系統(tǒng)硬件方案分析 .............................................................................................................. 5 系統(tǒng)軟件方案分析 .............................................................................................................. 5 第二章 單片機(jī) ....................................................................................................... 7 單片機(jī)內(nèi)部模塊 ...................................................................................................................... 7 MCS51 單片機(jī)內(nèi)部結(jié) 構(gòu) .................................................................................................. 7 MCS51 輸入 /輸出端口的結(jié)構(gòu)與功能 .......................................................................... 8 MCS51 單片機(jī)的引腳及其功能 ..................................................................................... 8 8051系統(tǒng)擴(kuò)展設(shè)計(jì) ............................................................................................................. 9 單片機(jī)外總線結(jié)構(gòu) ................................................................................................................. 9 芯片的擴(kuò)展設(shè)計(jì) .................................................................................................................... 10 第三章 系統(tǒng)硬件設(shè)計(jì) ......................................................................................... 12 溫度檢測(cè)和變送器 .............................................................................................................. 12 接口電路 .................................................................................................................................. 13 A/D 轉(zhuǎn)換電路 ......................................................................................................................... 15 可控硅驅(qū)動(dòng)電路 ................................................................................................................... 16 PID 控制 ................................................................................................................................... 17 硬件抗干擾措施 .................................................................................................................... 21 第四章 系統(tǒng)軟件設(shè)計(jì) ......................................................................................... 22 主程序 ........................................................................................................................................ 22 T0 中斷服務(wù)程序 .................................................................................................................. 24 采樣子程序 .............................................................................................................................. 27 數(shù)據(jù)處理 .......................................................................................