饲草推送机器人磁条导航自动充电研究

为了实现牛场勤密饲喂,饲草推送机器人自动充电系统采用上置对接式,由充电桩、机器人充电控制部分组成。充电桩包含蓄电池充电器、充电电路和充电电极等;机器人充电控制部分包含控制器、行走驱动模块、电源监控模块、传感数据采集模块、继电器和充电电极等。在充电对接部位建立坐标系XYZ,根据电极长度、电极压缩行程、电极宽度,确定X、Y、Z轴的对接容错范围。根据半开放式牛场工作环境,在自动充电区域设置充电桩、磁条导航路径。饲草推送机器人在磁条导航过程中,通过磁导航传感器实时检测磁信号,获得磁导航偏差,采用模糊PID控制算法,得到左右轮速度控制量后,转换成对应电动机角速度值,控制器输出对应占空比的PWM信号控制电动机转速。结合磁导航传感器特性和试验,获得模糊控制器的输出参数调整规则。自动充电磁条导航试验结果表明：当磁导航偏差绝对值|e|为最大值时,比例系数调整值ΔKp最大值为1.28,最小值为1.03;积分系数调整值ΔKi最大值为0.13,最小值为0.06;微分系数调整值ΔKd最大值为－1.18,最小值为－1.5;通过模糊PID控制,PID控制器系数可进行自适应修正;X轴、Y轴和Z轴最大对接偏差绝对值分别是4.1、1.9、0.7cm,对接偏差均在容错范围之内。     

槽式太阳能集热系统集热性能试验研究

槽式太阳能集热系统在太阳能热发电领域的应用比较成熟,由于其光-热转化效率高的特点,近些年在牧草干燥领域的应用也越来越多。为了进一步提高牧草干燥效率,以槽式太阳能集热系统作为稳定的干燥热风能源输出,研究其真空集热管集热性能和热损失是槽式太阳能热利用的关键。利用槽式太阳能集热系统加热导热油储能,通过追踪真空集热管进、出口温度和真空集热管内温度,阐述了进入真空集热管内的导热油瞬时温度与集热器瞬时光热转换效率和真空管热损失的关系。结果表明,集热器瞬时光热转换效率与导热油进入真空集热管的温度有关,进入真空集热管导热油温度越低,换热越充分,真空集热管热损失越少,真空集热管瞬时光热转换效率越高。加大真空集热管出口和入口的导热油温差是提高槽式太阳能集热蓄热能力的关键。     

小型往复式平衡惯性牧草收割机的研制

在现有牧草切割机的基础上,结合广西复杂的种植环境情况,设计了小型往复式平衡惯性牧草收割机。该小型往复式平衡惯性牧草收割机采用对称的双曲柄连杆机构将旋转运动来变换成割刀的往复运动,由机架、动力机构、传动机构及执行机构4部分组成。首先通过小型柴油机带动传动装置,从而带动双动刀片往复切割牧草;双动刀片同时做方向相反的往复直线运动,对双刀间的牧草进行剪切,牧草切割完后便沿着特殊设计的犁型曲面挡板滚落到车轮两侧。对称设计的动刀片在刀片变向瞬间可抵消大部分惯性,可有效平衡刀片在切割过程产生的惯性振动,使得切割后留茬平整,破头率降低,利于牧草的再次生长。试验结果证明:牧草破头率降低25%,作业质量符合农艺要求,结构设计合理,为非平原地带牧草收割提供了技术支持。     

创建秸秆饲草协会兴起一方饲草产业

通过创建饲草协会的实践,交流探索建设农民专业合作服务组织的方法和途径,促进协会工作的健康发展。     

The predictive value of quantitative genetic parameters in autogamous crops: Bias caused by intergenotypic competition. 2. F∞-variance

Summary Quantitative genetic theory for autogamous crops enables the estimation of the parameters m (F-mean) and D (F-variance) in the F₃-generation. With these estimated m and D a prediction can be made of the probability of finding superior inbred lines in the F-offspring of the cross. The accuracy of this procedure is influenced by the correctness of the genetic model, by the magnitude of the error variance, and by the bias caused by intergenotypic competition, which is present in the environment in which the F₃ is grown and absent in the monoculture environment at which the selection is aimed, especially in a cereal crop like wheat. The influence of the latter was investigated by a special method of simulating segregating populations. In this method genotypes in the offspring of a cross are represented by varieties and segregating populations are composed by mixing the appropriate varieties according to the proper segregation frequencies. Growing the simulated population enables the estimation of m and D in the normal selection environment, while simultaneously growing the varieties in a large monoculture trial enables the calculation of true values of m and D in the monoculture environment. Hence, a comparison is possible.The second of this set of two papers presents the investigations on the influence of intergenotypic competition on the estimation of the parameter D. The correlation between the estimates from the selection environment and the calculated true values from the monoculture environment was low. On the average the true values were overestimated, however in a few cases the monoculture values were significantly underestimated. Using the estimated m's and D's to rank crosses may lead to rather erroneous results.     

Water-use efficiency of wheat-based rotation systems in a Mediterranean environment

Crop production in Mediterranean-type environments is invariably limited by low and erratic rainfall (200-600 mm year⁻¹), and thus soil moisture, and by high evapotranspiration resulting from high temperature. Consequently, a major research challenge is to devise cropping systems that maximize water-use efficiency (WUE). In a long-term trial in northern Syria (1986-1998) we compared the effects of seven wheat-based rotations on soil water dynamics and WUE in both the wheat and non-wheat phase. The cropping systems were durum wheat (Triticum turgidum L.) in rotation with fallow, watermelon (Citrullus vulgaris), lentil (Lens culinaris), chickpea (Cicer arietinum), vetch (Vicia sativa), medic pasture (Medicago spp.), and wheat. Seasonal recharge/discharge were identified using the neutron probe. Depth of wetting varied with seasonal rainfall (233-503 mm). Based on crop yields, WUE was calculated for each cropping option in relation to the durum wheat crop.The greatest limitation to growth was the supply of water and not the soil moisture storage potential. Wheat grain yield was dictated by the extent to which the alternative crops in the rotation dried out the soil profile, in addition to seasonal rainfall and its distribution. Chickpea and medic extracted as much water as continuous wheat. Wheat after these crops was solely dependent on current seasonal rainfall, but fallow, lentil, watermelon, and vetch did not deplete soil moisture to the same extent, leaving some residual soil moisture for the succeeding wheat crop. This difference in soil water resulted in a significant difference in wheat yield and hence WUE, which decreased in the following crop rotation sequence: fallow, medic, lentil, chickpea, and continuous wheat. However, on the system basis, the wheat/lentil or wheat/vetch systems were most efficient at using rainfall, producing 27% more grain than the wheat/fallow, while the wheat/chickpea system was as efficient as wheat/fallow system, with continuous wheat being least efficient. With N added to the cereal phase, system WUE of the system increased, being least for continuous wheat and greatest for wheat/lentil. Wheat-legume rotation systems with additional N input in the wheat phase not only can maintain sustainable production system, but also are more efficient in utilizing limited rainfall.     

走式不分行青饲机切割器滑切角分析与计算

在对切割器进行动力学分析的基础上,给出了青饲机切割器动态切割角的定义和计算公式;详细分析了机器以不同作业速度行走时,切割器旋转1周过程中动态滑切角的变化规律,可按照统一方法描述滑切角的特性。同时,做出了动态滑切角增减量的函数曲线,该函数曲线对青饲机切割器的研究设计有重要意义,可直观看出滑切角的变化趋势,即青饲机作业速度越大,动态滑切角的变化幅度也越大。     

平贝母收获挖掘设备研究现状与发展趋势

平贝母采收作业是林区贝母种植的关键一环,对平贝母的成色与药用价值产生重要影响。现有的采收设备存在作业效率低、环境适应性差等问题。挖掘铲作为平贝母收获机的核心部件,尚存在结构设计单一化,研究思路半经验化等问题直接影响采收作业的质量。为研发能够满足行业需求的平贝母采收设备,结合现有种植条件及技术发展,对国内外根茎类作物收获机进行整体分析,提出研发可兼收其他作物的小型自走式联合收获机这一思路;对平贝母收获机及挖掘铲的发展情况进行深入剖析,提出平贝母收获机的发展方向为高效化、采收过程专业化、采收作物兼容化,平贝母挖掘铲的发展方向为研究思路科学化、研发手段专业化、运行性能稳定化,以期推动贝母产业全程机械化进程。     

基于小波去噪与SVR的小麦冠层含氮率高光谱测定

为改进小麦冠层含氮率的高光谱测定模型,以正交试验筛选出小波去噪的最优参数组合（小波类型取haar,分解层数为5,阈值方案选择Fixed form threshold,噪声结构定为Unscaled white noise）,并利用去噪后的小麦冠层光谱建立偏最小二乘回归（PLS）模型,对不同预处理方法进行比较分析。发现采用小波去噪结合一阶导数能最有效消除原始光谱的背景信息,此时PLS模型校正集均方根误差（RMSEC）为0.260,预测集均方根误差（RMSEP）为0.288。对经一阶导数结合小波去噪后的光谱用主成分分析（PCA）进行降维,以前6个主成份为输入变量,建立最小二乘支撑向量机回归模型（LS-SVR）,其RMSEC与RMSEP分别为0.154与0.259,具有比PLS模型更高的精度。结果表明：以小波去噪结合一阶导数去除小麦冠层反射光谱中的土壤背景信息以提高模型的精度是可行的,且LS-SVR是建模的优选方法。     

河套灌区粮食水足迹与虚拟水净输出时空演变

为了正确评价灌区内水资源使用对改善现有水资源管理的影响,文中引入水足迹与虚拟水概念,同时考虑降雨和灌溉用水,计算了1960—2008年内蒙古河套灌区粮食水足迹与虚拟水净输出量的时空变化,进一步评价了灌区水资源在区域内和区域间的分配.结果表明：1960—2008年河套灌区粮食水足迹由3.534×109m3减小为1.634×109m3,自2000年灌区粮食虚拟水净输出量呈下降态势,两者构成均以蓝水为主（90%）;空间分布上,河套灌区中部地区（杭后、临河和五原）的粮食水足迹和虚拟水净输出量较大,而其他地区（磴口和前旗）较小;1960—2008年,粮食生产用水在灌区用水总量中所占比例呈显著下降趋势,年均下降1.07%.粮食生产用水的大部分以虚拟形式输送到灌区外部,该比例近年有所降低,但2008年仍高达76.22%.未来河套灌区应注重绿水和蓝水资源利用效率的提高.该研究为灌区水资源管理宏观政策的制定和可持续发展的实现提供理论依据.