在Bounding-box及其改进方法研究中,普遍采用正方形的重叠区域的质心作为定位的结果,然而该正方形与实际无线传感器节点的通信区域模型之间存在较大差异,导致定位误差较大。针对此问题,提出一种改进的Bounding-box定位方法。该方法在定...在Bounding-box及其改进方法研究中,普遍采用正方形的重叠区域的质心作为定位的结果,然而该正方形与实际无线传感器节点的通信区域模型之间存在较大差异,导致定位误差较大。针对此问题,提出一种改进的Bounding-box定位方法。该方法在定位时,不再采用正方形的通信区域模型,而是采用圆形的通信区域模型进行定位。基于仿真数据以及采用3种典型通信环境下真实的到达信号强度指示(received signal strength indicator,RSSI)数据完成定位实验,实验结果表明,该方法具有较高的定位精度,因此具有一定的实际应用价值。展开更多
In order to design the inner and outer ring capacitance sensor used in measuring the correlation velocity of two phase flow and optimize its structure,the sensitivity characteristics of inner and outer ring capacitanc...In order to design the inner and outer ring capacitance sensor used in measuring the correlation velocity of two phase flow and optimize its structure,the sensitivity characteristics of inner and outer ring capacitance sensor were analyzed by using finite element simulation.The simulation experiment was planned by using orthogonal experimental design.From the simulation result,the major factors influencing the sensitivity characteristics(relative sensitivity and uniformity error) were obtained.The degree and tendency of influence of each factor on the sensitivity characteristics were given.The structural parameters of the sensor were determined.The analysis provided the theoretical basis for the inner and outer ring capacitance sensor.展开更多
文摘在Bounding-box及其改进方法研究中,普遍采用正方形的重叠区域的质心作为定位的结果,然而该正方形与实际无线传感器节点的通信区域模型之间存在较大差异,导致定位误差较大。针对此问题,提出一种改进的Bounding-box定位方法。该方法在定位时,不再采用正方形的通信区域模型,而是采用圆形的通信区域模型进行定位。基于仿真数据以及采用3种典型通信环境下真实的到达信号强度指示(received signal strength indicator,RSSI)数据完成定位实验,实验结果表明,该方法具有较高的定位精度,因此具有一定的实际应用价值。
文摘In order to design the inner and outer ring capacitance sensor used in measuring the correlation velocity of two phase flow and optimize its structure,the sensitivity characteristics of inner and outer ring capacitance sensor were analyzed by using finite element simulation.The simulation experiment was planned by using orthogonal experimental design.From the simulation result,the major factors influencing the sensitivity characteristics(relative sensitivity and uniformity error) were obtained.The degree and tendency of influence of each factor on the sensitivity characteristics were given.The structural parameters of the sensor were determined.The analysis provided the theoretical basis for the inner and outer ring capacitance sensor.
文摘为准确测量超薄壁回转件旋压后的外径尺寸,提出了一种基于重构横截面轮廓曲线的等效外径在机测量方法。该方法利用周向均布的3套线激光位移传感器与旋轮架的轴向移动模块,获得回转件任意轴向位置横截面的外轮廓数据;通过对3套传感器所获截面数据的坐标变换及数据匹配,实现截面完整轮廓数据的精确拼接,并以离散数据点的保形曲线重构方法重构截面外轮廓曲线,利用同一闭合曲线各变形状态的长度不变性,得到了截面等效外径;分别以芯轴及薄壁回转件开展了外径检测实验。实验结果表明:所提方法可准确测量超薄壁回转件外径,其精度为0.019 mm.