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哈爾濱理工大學(xué)學(xué)士學(xué)位論文 I 哈 爾 濱 理 工 大 學(xué) 畢 業(yè) 設(shè) 計 題 目: 基于熱電偶的控溫器設(shè)計 哈爾濱理工大學(xué)學(xué)士學(xué)位論文 II 基于熱電偶的控溫器設(shè)計 摘要 熱電偶( thermocouple)是 溫度測量儀表 中常用的測溫元件,它直接測量溫度,并把溫度信號轉(zhuǎn)換成熱電動勢信號。各種熱電偶的外形常因需要而極不相同,但是它們的基本結(jié)構(gòu)卻大致相同,通常由 熱電極、絕緣套保護(hù)管和接線盒等主要部分組成。 本文研究開發(fā)的抗干擾熱電偶控溫器,從電路設(shè)計、 PCB 電路板布局布線、到軟件設(shè)計等方面,對熱電偶工作的干擾信號進(jìn)行濾波處理,使這一熱電偶控溫器能夠在復(fù)雜的電磁環(huán)境下穩(wěn)定、可靠地工作。 為了達(dá)到提高測溫精度的目的,需要對熱電偶進(jìn)行冷端補償,以彌補熱電偶冷端處于室溫環(huán)境時造成的誤差;在 PCB 電路設(shè)計中,從電源、電纜、印制板三個層次對熱電偶控溫器進(jìn)行抗干擾設(shè)計;在軟件設(shè)計過程中,利用數(shù)字濾波技術(shù)進(jìn)一步對干擾信號濾波處理、并用線性插值法求解溫度值,最后用模糊算法實現(xiàn)控溫器 對環(huán)境溫度的控制。 關(guān)鍵詞 熱電偶;冷端補償;控溫器;抗干擾 哈爾濱理工大學(xué)學(xué)士學(xué)位論文 III A Design of Thermocouple Based Temperature Controller Abstract Thermocouple (thermocouple) is a monly used temperature sensor temperature measurement instrument, It measure the temperature directly, and the temperature signal is converted into the thermal electromotive force shape of the thermocouple is not the same because the different needs. but their basic structure are roughly the same, and usually pose of a hot electrode, insulating sleeve tube protector and the junction box and other main parts . This research is about the research of an antidisturbed temperature controller with thermocouple as its thermal order to make the temperature controller work stably and reliably in a plicated electromagic environment,different methods are used in the design methods cover different stages of the design,including the design of the hardware circuit,the layout of the printed circuit board(PCB),and the software design. In the design of the hardware circuit,in order to improve the accuracy of the temperature controller,it’s necessary to do some work on the cold junction the thermocouple is usually work with its cold junc tion in the room temperature rather than in the standard of 0℃ .In the PCB design stage,three design hierarchies are used to make the temperature controller immune to the disturbance of the electromagic environment,these hierarchies include:powersupply,electric cable,and the printed circuit the software design,the digital filter is used to finally filter the disturb signal,and the Fuzzy algorithmic approach is used to realize the thermal control. Keywords Thermocouple。 Cold junction pensation。 Temperature controller。 Antidisturb 哈爾濱理工大學(xué)學(xué)士學(xué)位論文 IV 目錄 摘要 ..................................................................................................................... I Abstract ................................................................................................................ II 第 1 章 緒論 ........................................................................................................ 1 課題背景 ................................................................................................... 1 國內(nèi)外發(fā)展現(xiàn)狀 ....................................................................................... 1 本設(shè)計技術(shù)指標(biāo) ....................................................................................... 3 本文主要研究內(nèi)容 ................................................................................... 3 第 2 章 熱電偶測量溫度原理 ............................................................................ 5 熱電偶傳感器分類 ................................................................................... 5 熱電偶的選取 ........................................................................................... 6 熱電效應(yīng)與熱電勢 ................................................................................... 6 熱電偶測溫基本原理 ............................................................................... 7 熱電偶的冷端補償 ................................................................................... 7 本章小結(jié) ................................................................................................... 8 第 3 章 熱電偶溫度控制 系統(tǒng)的硬件設(shè)計 ........................................................ 9 控溫器系統(tǒng)結(jié)構(gòu) ....................................................................................... 9 系統(tǒng)的信號選通及 A/D 轉(zhuǎn)換電路 .......................................................... 9 單片機 ..................................................................................................... 12 串行數(shù)據(jù)通信 ......................................................................................... 14 溫度控制電路 ......................................................................................... 18 本章小結(jié) ................................................................................................. 23 第 4 章 熱電偶溫度控制系統(tǒng)的軟件設(shè)計 ...................................................... 24 軟件總體方案設(shè)計 ................................................................................. 24 查表法和插值法相結(jié)合求解溫度值 ..................................................... 26 數(shù)字濾波 ................................................................................................. 26 模糊控制算法 ......................................................................................... 27 本章小結(jié) ................................................................................................. 28 結(jié)論 .................................................................................................................... 30 致謝 .................................................................................................................... 31 參考文獻(xiàn) ............................................................................................................ 32 附錄 .................................................................................................................... 34 哈爾濱理工大學(xué)學(xué)士學(xué)位論文 1 第 1章 緒論 課題背景 溫度( temperature)是表示物體冷熱程度的 物理量 ,微觀上來講是物體 分子熱運動 的劇烈程度。溫度只能通過物體隨溫度變化的某些特性來 間接測量 ,而用來量度物體溫度數(shù)值的標(biāo)尺叫 溫標(biāo) 。它規(guī)定了溫度的讀數(shù)起點(零點)和測量溫度的 基本單位 。國際單位為 熱力學(xué)溫標(biāo) (K)。目前國際上用得較多的其他 溫標(biāo) 有 華氏溫標(biāo) 、 攝氏溫標(biāo) 和 國際 實用溫標(biāo) 。從 分子運動論 觀點看,溫度是物體分子運動平均 動能 的標(biāo)志。溫度是大量分子熱