基于图标识别的微型UAV飞行高度估算

在基于DSP硬件平台的微型UAV视觉系统上,综合运用多种图像预处理算法及随机Hough变换算法,实现了针对特定图标的实时识别.同时通过对摄像头的简单标定,获取了拍摄图像与微型UAV实际飞行状况之间的映射关系.根据所设计的视觉系统在近地面对图标的识别,得到了摄像头与被摄图标的距离.最后通过对实验数据的分析,验证了视觉系统的有效性.     

基于经验模态分解的轴承故障诊断

简要介绍了轴承故障诊断的基本方法,通过对比共振解调法和经验模态分解法,证明了经验模态分解是一种适用于分析非线性、非平稳信号的方法.同时,通过实际例子验证了该方法可以用于有效地发现轴承故障,从而提高了诊断的准确性.     

基于磁放大器的分布式电源研究

研究并设计了一种新型的基于磁放大器分布式电源系统.该分布式电源系统采用高频母线形式,原边电路采用双管正激电路,电压前馈控制,后级利用磁放大器精确控制.这种电源系统具有高效、低成本、以及输出路数不受限制等优点.实验结果表明,该分布式电源系统可以得到纹波很小的各路精确电压.     

以太网供电系统及其功率扩展技术研究

在IEEE 802.3af协议下,利用新型以太网供电电能控制管理芯片,给出了含供电设备(PSE)和受电设备(PD)的标准以太网供电(PoE)系统设计方案,并分析了以太网供电原理和工作过程.给出了一种基于多变压器并联的以太网供电功率扩展方案,并给出了适应于扩展后功率的功率分级方案,解决了供电功率扩展问题,有利于提高以太网供电的应用范围.     

基于网络的电路原理实验系统

介绍了基于Internet的电路原理实验系统,它综合运用了网络、电路设计、面向对象编程及数据库等技术,将真实的物理设备与网络相结合,为局域网和Internet用户提供了一个开放的实验平台,使用户可以通过远程登录的方式进行电路原理实验。该实验平台时改进远程教学有很大的意义。     

高速列车车内声品质优化仿真研究

随着高速列车运行速度的不断提高,车内噪声问题对乘坐舒适性的影响越来越显著.为了抑制高速列车车内噪声的影响,基于改进的能量有限元方法,建立高速列车车内噪声的预测模型,并验证模型的准确性.基于预测模型,结合Zwicker响度模型、Zwicker尖锐度模型和Aures粗糙度模型,研究轮轨噪声激励的优化对车内声品质的影响.结果...     

电力市场下AGC机组运行考核算法的研究

针对传统AGC机组运行考核算法的不足,在AGC投入时对机组的调节速率和调节精度进行实时的测定与计算,并且考虑了AGC机组的响应时间对调节速率的影响以及系统运行人员与机组责任的区分;对调节容量根据计划交易日的前日各电厂对AGC调节容量的申报值进行计算。根据各电厂的考评结果对次月参与考评发电厂的月度发电量计划进行调整,并给出计算的公式、流程图和算例,最后对本软件的实际应用情况进行了介绍。     

Phase Partition of Acrylonitrile (AN) in Vinylidene Chloride (VDC)/Water System and Its Effect on VDC-AN Copolymer Composition

phase partition of acrylvnitrile in the vlnylidene chloride/water system at different temperature and under pressure was studied, A calculation method for average VDC-AN copolymer compeeition with AN phmm partition considered was proposed. The conversion results are in good agreement with the experimental data nearly the entire conversion rauge. VDC-AN copolymer with narrower composltion distribution can be prepared in the suspension process and interpreted with dynamic equilibrium of AN between the oil and water phases continuously.     

气固两相流中一种抗磨新方法的数值验证

The present paper intends to introduce a new method for reducing bends erosion from particles impacts:the ribbed bend erosion protection method. Ribs are evenly fixed in the range of 20°-80° on the inner-wall of inside 90° bend and the bend (including ribs) is made of medium carbon steel. Three-dimensional numerical work is performed and the result shows satisfactory agreement with the experimental measurement. Numerical simulation studies the characteristics of axial gas flow along the bend and secondary flow at cross section. Detailed analyses involving the impact velocity and incidence angle of particle- metal (either particle-rib or particle-duct) impact unveil the mechanism of the anti- erosion effect. As a result, predications achieve that the average erosion rate of the ribbed bends is only a third of the bare bend under test conditions and rectangle ribs possess higher anti-erosion effect than square ribs, while the wear distribution pattern remains unchanged after adding ribs onto the bend. All results confirm that the ribbed bend erosion protection method is a simple and effective method for reducing bends erosion from particles impacts.