本文關(guān)鍵詞：可自動控溫的氣敏（材料）測試系統(tǒng)的研制　出處：《吉林大學》2017年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 氣敏測試系統(tǒng) 阻值快速測量 溫度測量 PID控制 階梯式升溫

【摘要】：隨著科學的發(fā)展、物聯(lián)網(wǎng)和人工智能時代的到來,生活中的氣敏傳感器朝著檢測更全面、測量更準確的方向發(fā)展。為了有效地發(fā)揮氣敏材料形態(tài)、形貌、和結(jié)構(gòu)對氣敏特性的影響,進一步提高半導體氣敏傳感器的靈敏度,本課題組申請了國家自然科學基金項目《以三維網(wǎng)絡(luò)泡沫鎳為載體的多孔P-N異質(zhì)接觸結(jié)構(gòu)的制備及其氣敏特性研究》(批準號61474056),由于傳統(tǒng)的測試系統(tǒng)無法測試以泡沫鎳為載體的氣敏材料,我們設(shè)計了與之相匹配的、新型的氣體敏感特性測試系統(tǒng),并且有針對性地設(shè)計了在較寬的電阻測量范圍下,能夠快速測量的方法。該測試系統(tǒng)不僅能夠測試以多孔材料為基底的氣敏材料,還能測試粉末或薄膜狀氣敏材料,同時對溫度也能夠精確地測量,可使溫度按階梯式上升,使材料測試過程的操作更智能化。該測試系統(tǒng)包括測試模擬環(huán)境、硬件電路和上位機軟件三個部分。測試模擬環(huán)境主要包括氣箱的制作、測試探針的定制和測試臺的組建。通過使用定制的小彈力探針和微調(diào)架,達到保護多孔材料結(jié)構(gòu)的目的。硬件電路以嵌入式處理器ARM7為核心,主要分為電阻測量模塊,溫度測量模塊和加熱模塊。氣敏材料的工作溫度應(yīng)該是一個精確測量值,所以相比以往的大多數(shù)測試系統(tǒng),本設(shè)計增加了一個測溫模塊,能夠?qū)崟r檢測氣敏材料的溫度;為了實現(xiàn)阻值的快速測量,電阻測量模塊的設(shè)計使用了阻值范圍交叉式分檔測量的方法,適用于靈敏度在10000以下的氣敏材料的測試;加熱模塊由微控制器內(nèi)部集成的DA轉(zhuǎn)換器和外圍的功率運算放大器組成,形成數(shù)控電壓源,結(jié)合PID控制算法,可使加熱裝置的溫度按階梯式上升。本設(shè)計研究了氣敏材料的測試過程,使用PyQt軟件制作上位機界面,讓測試的操作過程變得更智能化。系統(tǒng)程序上分為兩種工作模式:工作模式一和工作模式二。工作模式一適用于尋求氣敏材料的最佳工作溫度點,可階梯式升溫,測試的整個過程不再需要人工調(diào)整;工作模式二適用于氣敏材料的響應(yīng)恢復特性測試,測試過程中不換電阻檔位,實現(xiàn)阻值的快速測量。兩種工作模式能夠大大地節(jié)省人力資源。本測試系統(tǒng)能夠?qū)σ远嗫撞牧蠟榛椎臍饷舨牧线M行測試;使用阻值范圍交叉式分檔測量的方法,測量范圍是1Ω~500MΩ,誤差率在2%以下,電阻值在10MΩ以上測量速度仍能到達10次/秒;使用常規(guī)PID和模糊PID相結(jié)合的控制算法,溫度控制更加快速、精確;溫度的測量范圍是0~500℃,誤差率在1%以下;為新型氣敏材料的開發(fā)提供了一個可靠的測試手段,具有一定的實際意義。
[Abstract]:With the development of science, the arrival of the era of Internet of things and artificial intelligence, the gas sensors in life are developing towards more comprehensive detection and more accurate measurement. The influence of the structure and the structure on the gas sensitivity of the semiconductor gas sensor can be further improved. The project of National Natural Science Foundation of China (Grant No. 61474056) has been applied for the preparation of porous P-N heterocontact structure with three dimensional network nickel foam as the carrier and its gas sensing characteristics. Because the traditional testing system can not test the gas sensing material with nickel foam as the carrier, we have designed a new type of gas sensitivity testing system. The method of rapid measurement is designed in a wide range of resistance measurement. The system can not only test the gas sensing material based on porous material. It can also test the powder or thin film gas sensing material, at the same time, the temperature can be accurately measured, which can make the temperature rise step by step and make the operation of the material test process more intelligent. The testing system includes the test simulation environment. The test simulation environment mainly includes the manufacture of air box, the customization of test probe and the construction of test bench. Through the use of customized small elastic probe and micro-adjusting frame. In order to protect the porous material structure, the hardware circuit is mainly divided into resistance measurement module with embedded processor ARM7 as the core. Temperature measurement module and heating module. The working temperature of gas sensing material should be an accurate measurement value, so compared with most previous test systems, this design adds a temperature measurement module. It can detect the temperature of gas sensing material in real time. In order to realize the rapid measurement of the resistance value, the resistance measurement module is designed by using the method of cross step measurement in the range of resistance, which is suitable for the test of gas sensing material with sensitivity below 10000. The heating module consists of a DA converter integrated in the microcontroller and a peripheral power operational amplifier to form a numerical control voltage source, combined with the PID control algorithm. The temperature of heating device can be increased by step. The test process of gas sensing material is studied, and the upper computer interface is made with PyQt software. The operating process of the test becomes more intelligent. The system is divided into two working modes: mode 1 and mode 2. Mode 1 is suitable for seeking the best working temperature point of gas sensing material. Stepwise heating, the whole process of testing no longer need to be manually adjusted; The second mode is suitable for the test of the gas sensing material's response recovery characteristic, and the resistance gear is not changed during the testing process. The two working modes can save human resource greatly. This testing system can test the gas sensing material based on porous material. By using the method of cross step measurement in the range of resistance, the measuring range is 1 惟 / 500M 惟, the error rate is below 2%, and the measuring speed of resistance value above 10m 惟 can still reach 10 times per second. Using the conventional PID and fuzzy PID control algorithm, the temperature control is faster and more accurate. The temperature measurement range is 0 ~ 500 鈩，

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