【作者】 邢振；

【导师】 杨青；

【作者基本信息】 西北农林科技大学 ， 机械设计及理论， 2008， 硕士

【摘要】 土壤水分的测量和控制是实施精细农业的关键技术。对土壤水分的实时监测,有助于作物的生长、提高肥料的利用率和避免对地下水造成污染。由于传统测量土壤水分的方法存在测量周期长、工作繁琐和测量成本高等缺点,因此,研制开发出一种精度高、可靠性好、实时性强的土壤水分测量仪亦是当务之急。本论文根据我国农业生产以及实施精细农业的实际需要,在对近红外光谱测量土壤含水率进行理论研究的基础上,应用近红外光谱分析技术,研究开发了一种基于双光谱、实时非接触快速测量土壤水分的测量仪。所做的主要工作如下:1.利用国外高精度手持便携式光谱辐射仪进行了土壤水分的测量实验,分析了土壤湿度和土壤光谱反射率之间的关系,为近红外光谱测量土壤水分含量提供了理论依据。2.在深入研究近红外光谱测量水分的原理和成果、比较近红外光谱测量其它物质水分方案的基础上,建立了基于双光谱的土壤水分测量模型。3.充分考虑系统低功耗和可靠性要求,采用先进的集成芯片和光谱测试技术,建立了系统的硬件平台。4.应用模块化设计思想、C语言及汇编语言的相互嵌套、以及防脉冲干扰平均滤波法等措施,提高了整个系统的运行效率和测量精度。5.采用最小二乘法对数据进行回归分析,完成了对系统的标定。对系统进行重复性测试,结果表明系统具有较好的重现性,说明本系统可以实现对土壤水分的实时测量。6.本测试系统的定标模型不仅能应用于土壤水分测量,也为开发其它利用近红外光谱技术的智能化仪器提供了一种方法和平台。更多还原

【Abstract】 It is key technology to measure and control soil humidity when actualizing precision agriculture. It is helpful for crop growth, improving fertilizer’s using ratio and avoiding polluting groundwater to inspect soil moisture at real time. The traditional methods exist some disadvantages, for example, long measuring period, cockamamie working and high measuring cost. Therefore, it is urgent affairs to develop a measuring instrument about soil moisture which have high precision, fine reliability and good real time.According to practical demand about agriculture production and actualizing precision agriculture inland, this paper researched and designed a measuring meat about soil humidity based on two spectral bands and having real time, non-contacting and celerity and applied near infrared spectrum analysis technology. The research is based on theoretical study about measuring soil percentage of moisture using near infrared spectrum. Main work as follows:1. Carrying out measuring experiment about soil humidity using spectrum actinograph which has advantages of high precision and hand-portable. Analyze the relationship between soil humidity and soil spectrum reflectivity to provide theoretical gist for near infrared spectrum to measure soil humidity.2. Researching the principle and production about measuring moisture by near infrared spectrum, comparing measuring other matter’s moisture by near infrared spectrum and then founding the model of soil moisture measuring based on two spectral bands.3. Considering the request of low power consumption and reliability about the system, founding the system’s hardware flat roof adopting advanced and integrated CMOS chip and spectrum testing technology.4. Applying some measures to improve the whole system’s function efficiency and measuring precision, for example, modularizing design idea, one another nesting between C language and assembly language and average smoothing mean which can avoid pulse disturbing and so on.5. Regressively analyzing the datum by applying least square so as to complete demarcating the system. The results indicated that the system has better recurrence and can realize real-timely measuring soil humidity by testing repeatability.6. This testing system can not only be applied for measuring soil humidity, but also provide a method and platform for exploiting other intellectualized instruments by near infrared spectrum technology.更多还原