發(fā)布時間：2018-04-11 19:20

  本文選題：半導(dǎo)體激光器恒功率 + 雙閉環(huán)��； 參考：《長安大學(xué)》2017年碩士論文

【摘要】：溶解度是反映試劑溶解性的重要參數(shù),固液溶解度參數(shù)廣泛應(yīng)用于醫(yī)學(xué)、化學(xué)、工業(yè)生產(chǎn)等多個領(lǐng)域,然而目前已有的固液溶解度參數(shù)測量方法還不夠成熟和完善,傳統(tǒng)方法如平衡法、動態(tài)法等測定溶液溶解平衡終點都要人眼進(jìn)行目測,其缺點是由于人為因素的加入導(dǎo)致誤差大且效率低下,并且只能進(jìn)行靜態(tài)測量。針對傳統(tǒng)方法存在的缺陷設(shè)計一種高精度、高效率的自動化動態(tài)溶解度檢測系統(tǒng)無疑對化學(xué)、醫(yī)學(xué)、工業(yè)生產(chǎn)的溶解度實驗具有重要的現(xiàn)實意義。為此,基于Lambert溶液光學(xué)吸收定律,本文提出了一種采用穩(wěn)定的激光光源照射、靈敏的光電二極管探測、計算機動態(tài)采集溫度—時間和光強—時間的自動化動態(tài)高效溶解度檢測系統(tǒng)。圍繞設(shè)計工作中的核心和關(guān)鍵,本文的研究內(nèi)容如下:首先,分析了Lambert定律光學(xué)吸收原理的使用依據(jù)和范圍以及造成Lambert定律偏離因素,針對影響系統(tǒng)測量精度的核心因素,研究了半導(dǎo)體激光器恒功率控制算法,設(shè)計了雙閉環(huán)激光器恒功率控制模型,提出基于神經(jīng)網(wǎng)絡(luò)PI控制的激光器恒功率控制算法,并通過仿真實驗驗證了算法的有效性。本部分設(shè)計了以PIC單片機為核心的激光器恒功率控制硬件電路,算法實現(xiàn)程序,最終實現(xiàn)了功率波動在2.4%的穩(wěn)定控制精度。接著,針對系統(tǒng)對激光光強、溫度檢測系統(tǒng)的要求,研究并設(shè)計了接收系統(tǒng)硬件電路和軟件程序。接收電路采用靈敏的光電二極管和高精度熱電阻溫度傳感器構(gòu)成光強、溫度檢測實時電路,重點分析和設(shè)計了光電轉(zhuǎn)換電路的信號調(diào)理,并通過仿真實驗進(jìn)行了驗證,最終實現(xiàn)了信號的高精度采集和傳輸,提高了系統(tǒng)的自動化程度和測量精度。最后,構(gòu)建了系統(tǒng)的整體原理樣機,并在陜師大化學(xué)實驗室進(jìn)行了系統(tǒng)實測實驗。實驗采用10~50℃之間的KCI-H2O體系為標(biāo)準(zhǔn)體系驗證系統(tǒng)的可行性,結(jié)果顯示,半導(dǎo)體激光器的輸出光功率穩(wěn)定,測得KCI-H2O體系中KCI溶解度誤差為±0.005kg,與設(shè)計要求值吻合良好。該檢測系統(tǒng)可以克服傳統(tǒng)檢測方法的不足,大大提高了溶解度檢測的精度和效率,滿足了不同行業(yè)的需求。
[Abstract]:Solubility is an important parameter reflecting the solubility of reagents. Solid-liquid solubility parameters are widely used in many fields, such as medicine, chemistry, industrial production, etc.The traditional methods, such as equilibrium method and dynamic method, all need human eyes to observe the end point of solution dissolution equilibrium. The disadvantage of this method is that the error is large and the efficiency is low due to the addition of human factors, and only static measurement can be carried out.Aiming at the defects of traditional methods, it is of great practical significance to design an automatic dynamic solubility detection system with high accuracy and efficiency for chemical, medical and industrial experiments.In this paper, based on the optical absorption law of Lambert solution, a sensitive photodiode detector with a stable laser light source is proposed.Automatic dynamic and efficient solubility measurement system for temperature-time and light intensity-time acquisition by computer.The research contents of this paper are as follows: firstly, the basis and scope of the optical absorption principle of Lambert's law and the factors causing the deviation of Lambert's law are analyzed, and the key factors that affect the measurement accuracy of the system are analyzed.In this paper, the constant power control algorithm of semiconductor laser is studied, the model of double closed loop laser constant power control is designed, and the algorithm of constant power control based on neural network Pi control is proposed, and the validity of the algorithm is verified by simulation experiment.In this part, the hardware circuit of laser constant power control based on PIC single chip microcomputer is designed. The algorithm realizes the program, and finally realizes the stable control precision of 2.4% power fluctuation.Then, the hardware circuit and software program of the receiving system are studied and designed according to the requirements of the system for laser light intensity and temperature detection system.The receiving circuit is composed of sensitive photodiode and high precision thermistor temperature sensor. The real time circuit of temperature detection is used. The signal conditioning of photoelectric conversion circuit is analyzed and designed, and verified by simulation experiment.Finally, the high-precision acquisition and transmission of signals are realized, and the automation and measurement accuracy of the system are improved.Finally, the whole principle prototype of the system is constructed, and the system experiment is carried out in the chemical laboratory of Shaanxi normal University.The feasibility of the system is verified by using the KCI-H2O system between 10 鈩，

本文編號：1737330