【作者】 张惠莉；

【导师】 孙宇瑞；

【作者基本信息】 中国农业大学 ， 农业电气化与自动化， 2002， 硕士

【摘要】 随着信息技术在农业领域的深入应用，作为农业科技革命的“精细农业”技术体系越来越受到人们的关注。“精细农业”技术思想的核心是根据农田小区的实际需求实施定位调控的“处方农作”。因此获取农田小区产量信息，建立小区产量空间分布图，是实施“精细农作”的起点。 目前我国“精细农业”的研究尚处于起步阶段，尤其是在基础理论和方法研究方面。因此，谷物流量实时在线测量方法作为当前“精细农业”体系中的基础环节及亟待解决的关键技术之一，在我国尝试性地在实验室中进行多种方案的并行探索是十分必要的。 关于谷物流量在线测量的研究方法，有光电、冲量法、核辐射及电容传感器等。这些测量方法虽各具特色，但至今在应用上仍还有各自的缺陷需要解决。本文借助于国外的研究经验，根据“精细农业”研究体系的实际需要深入研究了两种具有潜在应用前景的谷物流量在线测量方法，即基于γ射线衰减原理的测量方法和基于冲量原理的压电晶体传感器谷物流量在线测量方法。针对两种方法设计研制了两套实用的面向康拜因的谷物流量在线测量试验系统，并在此基础上对两种测量方法进行了动态试验与精度分析比较，找出了影响测量精度的多种相关因素，给出了确定性结论。试验结果显示，γ射线测量系统精度可达到2％以内，压电晶体传感器测量精度约为5％，表明系统是有效可行的。本文软件系统的设计采用虚拟仪器开发环境，具有良好的可操作性和直观性。 本文在国内率先进行了谷物流量动态在线测量方法的试验研究，并尝试性地将压电晶体传感器用于冲量式谷物流量测量方法中，这在国内外均未见报道。这些研究工作为研制我国自己的带产量传感器的谷物联合收割机奠定了理论基础。更多还原

【Abstract】 The research of Precision Agriculture that is an agricultural science revolution has made more and more people s attention along with information technology applying in agriculture. It is the bas of PA that using the spatial variable information of field to bear on decisions associated with agricultural production. This needs the support of technology of obtaining field yield information and making yield map.In our country,the research of Precision Agriculture is in beginning stage now,especially in basic theory and method studying. Yield-measurement is a key technology of desiderating resolution in Precision Agriculture system. It is necessary in our country that studying the methods of grain-flow-measurement in lab.Many methods of measuring grain flow on combines are presented in the literature,such as volumetric method,impact sensor,radiometric method and capacitor sensor,etc. There are some disadvantages needing resolution in application about these methods,although they have some feature. In this paper,two kinds of grain-flow-measurement-systems for combine harvesters are developed in laboratory,radiometric sensor using the principle of the absorption of y-rays by grains and piezoelectric crystal sensor using the principle of impact. The static experience about the absorption of y-rays by different grains has been made. Furthermore we made the dynamic calibrating and testing experience for two kinds of systems,analyzed and compared the precisions of two methods,and found some correlation factor of affecting measurement precision. The test results show that the measurement errors of y-ray measurement system are within 2%,and the errors of piezoelectric crystal measurement system are about 5%. It indicates that the systems are feasible. In the design of software,we adopted virtual instrument,and selected PCI-1200 as the DAQ card.This paper firstly makes experience study of grain flow dynamic measurement for combines in China. Piezoelectric crystal sensor used in impulse measurement method is a try and has not been presented in any reports. These study work establish theory basis for developing homemade combine harvesters with vield monitor.更多还原