【正文】 物理科學(xué)與工程技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 1 基于單片機(jī)的爐溫自動(dòng)控制系統(tǒng)設(shè)計(jì) 宜春學(xué)院 物理科學(xué)與工程技術(shù)學(xué)院 自動(dòng)化專(zhuān)業(yè) 肖杰鳴 指導(dǎo)老師： （徐東輝） 摘要： 在工農(nóng)業(yè)生產(chǎn)中，溫度是工業(yè)生產(chǎn)對(duì)象中主要的被控參數(shù)之一。電阻爐是通過(guò)電流流過(guò)電阻體產(chǎn)生熱量來(lái)加熱或熔化物料的一種電爐。電阻爐廣泛地應(yīng)用在化工、冶金等行業(yè)。它對(duì)溫度控制的要求較高，溫度控制的好壞直接影響著產(chǎn)品質(zhì)量及生產(chǎn)效率，因此電阻爐的溫度控制在科學(xué)研究、工業(yè)生產(chǎn)中具有重要的意義。 本設(shè)計(jì)采用單片機(jī)作為數(shù)據(jù)處理與控制單元， 以 電阻爐 作為 控制對(duì)象 ，用熱電偶作為測(cè)量元件，用晶閘管作為輸出控制元件來(lái)實(shí)現(xiàn)對(duì)電阻爐溫度自動(dòng)控制。 該系統(tǒng) 利用 K 型熱電偶溫度傳感器，把檢測(cè)到的電阻爐溫度的信號(hào)送入 MAX6675 芯片，經(jīng)過(guò) 信號(hào)放大等一系列轉(zhuǎn)換后， 再將信號(hào)送到 單片機(jī) STC89C52 內(nèi)進(jìn)行 PID 運(yùn)算， 同時(shí)可以通過(guò)鍵盤(pán)調(diào)節(jié) PID 參數(shù)。 經(jīng) PID 運(yùn)算后，比例調(diào)節(jié)輸出量改變 晶閘管控制量，變晶閘管的導(dǎo)通角，從而控制電阻爐的加熱強(qiáng)度。 從而 控制電阻爐的爐溫。 關(guān)鍵詞 ： 電阻爐； MAX6675； 單片機(jī) STC89C52； PID控制 Abstract： SummaryIn the industrial and agricultural production , the temperature is accused of one of the main objects of industrial production parameters . Furnace current flowing through the resistor generates heat to a furnace for heating or melting the material . Resistance furnace is widely used in chemical, metallurgical and other industries. It requires a higher temperature control , temperature control has a direct impact on product quality and production efficiency , and therefore resistance furnace temperature control is of great significance in scientific research , industrial production. The design uses a single chip for data processing and control unit to resistance furnace as a control object , as the measuring element with thermocouple with thyristor as a control element to achieve the output resistance furnace temperature control . The system uses K type thermocouple temperature sensor , to detect resistance furnace temperature signal into the MAX6675 chip , after a series of converted signal is amplified and then signal to the microcontroller STC89C52 PID operation , and can adjust the keyboard PID parameters. After the PID operation , adjust the output volume ratio of the amount of change in thyristor controlled , variable thyristor conduction angle, so as to control the intensity of the resistance heating furnace . To control the furnace temperature resistance furnace . Key words： The resistance furnace。 MAX6675。 SCM STC89C52。 PID contro 物理科學(xué)與工程技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 2 目錄 第 1 章 緒論 .................................................................................................... 3 課題研究的背景及意義 ................................................................................................... 3 第 2 章 系統(tǒng)總體設(shè)計(jì)方案 ................................................................................. 4 設(shè)計(jì)總體思路 ................................................................................................................... 4 系統(tǒng)技術(shù)指標(biāo) .................................................................................................................. 4 系統(tǒng)總體設(shè)計(jì)方案 ............................................................................................................ 4 第 3 章 系統(tǒng)硬件設(shè)計(jì) ....................................................................................... 6 溫度檢測(cè)部分 ................................................................................................................... 6 K 型熱電偶 ............................................................................................................. 6 溫度信號(hào)處理芯片 MAX6675 ..................................................................................... 6 時(shí)鐘電路 ......................................................................................................................... 9 復(fù)位電路 ......................................................................................................................... 9 串口通信電路 .................................................................................................................. 9 報(bào)警電路 ....................................................................................................................... 10 顯示電路 ....................................................................................................................... 10 按鍵電路 ....................................................................................................................... 12 D/A 轉(zhuǎn)換電路 ................................................................................................................. 13 第 4 章 軟件設(shè)計(jì) ............................................................................................. 15 軟件設(shè)計(jì)思路 ................................................................................................................ 15 主程序流程圖 ................................................................................................................ 15 溫度檢測(cè)與處理子程序 ......................................................................................... 16 報(bào)警子程序 .......................................................................................................... 17 PID 子程序 ........................................................................................................... 18 顯示流程圖 .......................................................................................................... 19 鍵盤(pán)掃描流程圖 ................................................................................................... 20 鍵盤(pán)處理流程圖 ................................................................................