共查询到20条相似文献，搜索用时 187 毫秒
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研究了一种测量流动谷物含水率的声学方法。通过试验,确定了大豆流声信息与含水率的关系。在200～310Hz频率范围内分析了含水率9％～16％时声压与含水率、流量、声源距离、下落高度诸因素的关系,并建立了数学模型。 相似文献
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在线谷物水分测试精度影响因素的试验研究 总被引：1，自引：0，他引：1
设计了分流式取样装置,配备无级变速的叶轮式排粮机构,在实验台上对谷物进行试验研究,分析了谷物流速、含杂率以及温度等因素对传感器输出频率的影响规律,自主研制电容式谷物水分传感器并通过烘箱法进行标定试验,试验结果表明：该传感器的水分测量范围：11%～24%,测量精度：≤0.5%;在常温下,低水分段时测量结果波动很小,基本满足在线谷物水分测量的要求。 相似文献
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谷物烘干机出粮含水率的在线测量与控制 总被引：1，自引：0，他引：1
王一鸣 《北京农业工程大学学报》1995,15(4):84-90
提出利用介电损失角测量谷物含水率的方法，设计了一种新型电容传感器和由激励电路、选频放大器、相敏波电路、低通滤波电路等组成的检测系统。通过对京４１１小麦的试验建立了谷物含水率与介电损失角正切值之间的分段线性关系。 相似文献
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农作物产量自动监测技术及关键设备 总被引：2，自引：0，他引：2
为实现谷物产量的实时测量,将测产系统搭载在联合收割机上是最好的选择。本文概述了农作物产量监测系统的四个重要组成部分(谷物流量传感器;谷物水分传感器;GPS接收机;田间计算机和用户界面)的工作原理和关键技术。特别是对几种类型的谷物流量传感器的工作原理作了较为详细的介绍。 相似文献
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粮食丰产科技工程是确保我国粮食安全和农业增产、农民增收而实施的一项重大科技工程。为了探讨粮食丰产科技工程对我国粮食增产的作用,从我国粮食需求、该工程实施的必要性和工程实施成效等三方面进行了论述,并从"三区"建设（核心区、示范区、辐射区）,三大作物的技术集成、技术攻关、超高产突破、储粮减损技术、防灾减灾技术、科技特派员制度和涉农企业与工程结合模式等几个角度具体分析了粮食丰产科技工程的实施成效。 相似文献
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Comparisons were made between yield measurements with an impact based yield sensor and an electronic scale in adjacent harvest strips and on the same grain stream within a combine. Yield measurements in adjacent strip comparisons were more prone to errors as the segment lengths decreased. Grain yield difference between the yield sensor and electronic scale ranged from 5 to 14%, 4 to 13%, 3 to 12%, and 2 to 11% for 15, 30, 60, and 300 m long segments. The yield differences between neighboring segments might have been caused by yield variability to a degree; however, a consistent decrease in yield differences with increasing segment lengths implied that better accuracies could be obtained in longer management areas. The combine responses to grain yield changes and the effect of varying ground speed on accuracy were also evaluated by creating artificial yield patterns in harvest strips. Grain diffusion within the combine was more obvious when abrupt yield changes were introduced at known locations. Grain mixing and redistribution inside the combine may dictate the selection of segment sizes in the site-specific decision making process. Constant ground speed provided more stable grain flow values than varying ground speed. The average error in yield estimate was 3.4% and 5.2% at constant ground speed and varying speed, respectively. Careful calibration and constant combine speed were important to achieve better accuracy with the grain yield monitor. 相似文献
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Grain flow measured at the flow sensor in a commercial yield monitoring system is considered to be the convoluted result of grain entering the harvester at one time being mixed by the internal threshing and transport processes with grain entering at other times. A transfer function describing the flow of grain within a conventional combine harvester was used to deconvolve the recorded signal using Fast Fourier Transformation (FFT). This process of time series analysis was shown to reposition the yield data in a more accurate manner than the simple time-delay process currently employed. The deconvolution increases the variability in the yield data from 10% to 17% which more closely resembles the variation in crop yield expected from small area samples. The spatial structure of yield variation obtained from small area samples was also shown to be more closely estimated by the deconvoluted data set, however the process does display sensitivity to noise introduced by mechanical/electrical sources and procedural errors. 相似文献
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基于品种熟期和籽粒脱水特性的机收粒玉米适宜播期与收获期分析 总被引：8，自引：2，他引：6
【目的】规模化生产条件下,需要兼顾产量和效率的协同提高。通过合理配置不同熟期品种及播期,能够延长播种和收获的机械作业时间,提高机械利用效率和玉米生产效率。【方法】本研究于2015—2017年,选用KWS9384、新玉77和M751 3种不同熟期的主栽玉米品种,观测籽粒含水率变化动态,建立基于授粉后积温(≥0℃)的籽粒含水率预测模型,结合当地气象数据,分析不同品种的播种与收获时期。【结果】结果表明,不同熟期品种的产量和适播期不同。早熟品种KWS9384适宜播期和收获期更长,但产量较晚熟品种低;晚熟品种新玉77和M751产量高,但满足生理成熟及脱水至适宜机械粒收含水率的时间更长。通过早熟品种和晚熟品种的搭配,可以有效延长玉米播种及机械粒收的作业时间;早播晚熟品种、晚播早熟品种的配置方案,能够较好地协调产量和籽粒脱水的关系。【结论】通过分析不同品种适宜播种期及其相应的适宜收获期,提出了高产高效协同生产目标下的品种和播期配置原则,实现特定生态和生产条件下机具利用效率和效益的最大化,为相关技术需求的研究和应用提供思路。 相似文献
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A Review of Combine Sensors for Precision Farming 总被引：9，自引：0，他引：9
To maximize economic return from agricultural production units, costs have to be minimized and benefits maximized. For grain, kernel yield and quality have to be maximized while the use of seeds, fertilizer, herbicides and fungicides have to be optimized.The best location to evaluate productivity levels, by measuring yield and quality of grain and straw, is the combine harvester. Moreover, other grain quality characteristics like density or test weight can be determined for use as an evaluation tool. In this paper, an overview is given of the past and current research toward the evaluation of currently available commercial sensors (e.g., for measuring grain yield and grain moisture content) as well as toward the development of new sensors (e.g., grain protein content and straw yield). 相似文献
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依据1949~2008年粮食主产区粮食产量统计数据,应用波动理论分析了粮食主产区粮食产量波动情况。结果表明,粮食主产区粮食产量是在不稳定的波动中增长的,其波动周期频度较高,长度比较规则;波动幅度总体呈中度,稳定性不强;粮食产量波动具有对应性,体现了现阶段粮食生产＂N＂字形的发展态势;粮食产量波动具有梯次性;在粮食产量波动性比较中,粮食主产区粮食生产年均增长率高于全国平均水平,但相对波动系数也高于全国平均水平。从自然灾害、农业政策、生产性投入、粮食价格和粮食流通5个方面剖析了粮食主产区粮食产量波动的原因,并提出了防御和平抑粮食产量超常波动的措施：一是坚持严格的耕地保护制度,努力提高耕地质量;二是加强粮食生产基础设施建设,增强抵御自然灾害的能力;三是加快农业科技进步,构建强有力的科技支撑体系;四是注重农业组织制度创新,为农业技术措施的应用提供实施路径和载体;五是建立健全灾害防控体系和粮食市场体系,增强粮食生产抗御风险的能力。 相似文献
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玉米机械粒收质量现状及其与含水率的关系 总被引：60，自引：2，他引：58
【目的】机械粒收技术是现代玉米生产的关键技术,是国内外玉米收获技术发展的方向和中国玉米生产转方式的关键。明确当前中国玉米机械粒收质量的现状,研究影响收获质量的主要因素,推动玉米机械粒收技术发展。【方法】利用2011—2015年在西北、黄淮海和东北和华北玉米产区15个省(市)168个地块获得的1 698组收获质量样本数据,分析当前中国玉米机械粒收质量的现状及其影响因素。【结果】结果表明,籽粒破碎率平均为8.63%,杂质率为1.27%,田间损失籽粒(落穗、落粒合计)为24.71 g·m~(-2),折合每亩损失16.5 kg,平均损失率为4.12%,破碎率高是当前中国玉米机械粒收存在的主要质量问题。收获玉米籽粒平均含水率为26.83%,含水率与破碎率、杂质率及机收损失率之间均呈极显著正相关。其中,破碎率(y)与籽粒含水率(x)符合二次多项式y=0.0372x~2-1.483x+20.422(R~2=0.452**,n=1 698),在一定含水率范围内(含水率大于19.9%),破碎率随籽粒含水率增大而增大。【结论】当前中国玉米机械粒收时破碎率偏高,而籽粒含水率高是导致破碎率高的主要原因。对此,建议选育适当早熟、成熟期籽粒含水率低、脱水速度快的品种,适时收获,配套烘干存贮设施等作为中国各玉米产区实现机械粒收的关键技术措施。 相似文献
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Grain separation loss monitoring system in combine harvester 总被引：5，自引：0，他引：5
Zhan Zhao Yaoming LiJin Chen Jiaojiao Xu 《Computers and Electronics in Agriculture》2011,76(2):183-188
Based on laboratory experimental results obtained with an axial threshing test-rig with tangential feeding, cumulative distribution functions of separated grain in axial and radial directions of threshing rotor were built. Based on the analysis of the relationship between grain separation loss and grain separation flux in an area under the concave, an indirect grain separation loss monitoring method is presented in this paper.Piezo-electric polyvinylidene fluoride (PVDF) film was selected as sensitive material to design a grain flux sensor. While grain and material-other-than-grain (MOG) separated in the monitoring area impact on piezo-electric PVDF films, different electric charges are generated. After signal progressing with a charge amplifier, frequency discrimination and wave shaping, the number of grain can be counted by a microcontroller (MCU) and the grain separation loss of combine harvester can be measured in real-time.Field test results indicated that the measurement errors of grain separation loss recorded by the monitoring system relative to the loss checked manually were less than 12%. 相似文献
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基于时空回归模型的河南省粮食产量预测 总被引：1，自引：1，他引：0
综合运用相关分析、回归分析和时间序列分析法,把时间和空间结合起来建立河南全省及各地市粮食产量时空回归预测模型。首先用2000、2005年的河南省各地市的粮食产量建立回归方程,然后以某一年的粮食产量作为自变量,预测其后第5年的粮食产量,得到的因变量数值再作为自变量,预测相隔同样年份的粮食产量,以此往前逐年移动预测,一直预测到所需年份。研究表明,河南省2015、2020年的粮食产量分别是5984.96万、6792.93万t,与其他研究者的研究结果有一定程度的吻合。 相似文献