共查询到19条相似文献,搜索用时 312 毫秒
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为了对大范围的工业管道检测装置进行精确定位,采用无线传感器网络,在工业管道外布置磁传感器模块来测量管道检测装置的磁信号.每个磁传感器模块由磁传感单元、处理单元、收发单元、电源单元等功能模块组成.磁传感器模块的测量数据由无线传感器网络传送到处理中心.处理中心依据无线传感器网络发回的磁信号数据,由磁定位算法计算得到管道检测装置所处的精确位置,从而实现管道检测位置的精确定位. 相似文献
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本文研究了混沌Duffing振子在弱信号检测系统中表现出的统计特性,说明了Lyapunov指数的统计特性与弱信号检测和估计之间的关系.之前的一些研究表明,混沌系统可以用于弱信号的检测,并将Lyapunov指数作为判定混沌状态的确定性依据.但本文的研究工作表明,弱信号检测系统中的Lyapunov指数存在一定的统计特性,将其作为信号检测判据需要考虑更多因素.因此,本文从理论上分析了混沌弱信号检测系统的Lyapunov指数存在的统计特性,并利用仿真数据建立了统计模型,确立了混沌检测系统的虚警概率和检测概率的计算方法.进而推导出了策动力阈值门限的选取公式和弱信号检测信噪比,给出了信号幅度估计的方法.实验结果表明,混沌弱信号的检测和估计性能与采样时间和采样间隔密切相关,可以采用统计信号检测的理论来衡量其性能. 相似文献
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高压海底电缆具有耐腐蚀、抗冲击性能好和电气寿命长等优点,是海上输电系统的重要组成部分,为保证海底输电系统正常运行,设计并开发了基于弱磁探测技术的高压海底电缆精确定位系统。装设海底弱磁探测器作为弱磁探测技术的执行元件,改装高压海底电缆精确定位器。根据高压海底电缆的组成结构、电力学工作原理以及磁场分布特征,构建高压海底电缆及其磁场等效模型。采集高压海底电缆的实时状态数据,利用弱磁探测技术获取高压海底电缆周围的磁信号,通过信号特征匹配与坐标计算,得出高压海底电缆精确定位结果。通过系统测试实验得出结论:与传统定位系统相比,优化设计系统定位静态电缆的平均误差降低约10.82m,定位动态电缆的平均误差降低了11.37m,表明了所设计系统在定位精度方面具有明显优势。 相似文献
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根据微弱光离子化信号的检测需要,开发出一种光离子化信号数据采集与处理系统。利用AD7710在微小信号测试方面的优势,以AT89C52为主控对硬件系统的组成和结构进行了设计,实现了电压信号的数据采集与A/D转换、数码显示和数据串口发送。软件系统采用模块化设计,分为数据采集、数据存储和数据串口发送模块等。利用国家标准物质中心配制的标气,系统可以有效检测挥发性有机化合物浓度,检测极低限达到了1 ppb。 相似文献
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We describe the organization of a general purpose data archival system for Write-Once, Read-Many (WORM) optical disks. The system has been designed for large-scale and long-term data storage and retrieval. The archival system is independent of the operating system, flat, self-consistent, does not use any write cache on magnetic disk, and allows the exploitation of auxiliary information on magnetic disk, which can be rebuilt immediately in case of a crash, to speed up file retrieval. A library in C language, called pODLIB, has been implemented as a portable interface to the archival system. 相似文献
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Flexible magnetic tape is widely used for data storage and archival, as future generation of tapes and drives will continue to increase overall storage capacities and data transfer rates. Tape portability, robust drive operation, longevity of magnetic media, and improved performance of head–tape interface under long-term use are required for magnetic tape to maintain a stronghold in the field of storage devices. Comparative studies were performed to investigate differences in performance of various cartridges in impact, tapes under long-term durability, and contamination of head–tape interface in advanced linear tape drives. A drop test was performed in which various cartridges were dropped from varying heights. Cartridge damage was recorded and indexed. Reinforced cartridge casing promotes good stability at low height impact, while casing significant plastic deformation in increased-height drops. Contamination and durability studies were performed in which debris generation, tape edge damage, tape cupping profiles, and error data was collected and analyzed for studies of head–tape interface. Most significant loose debris generation occurs as a result of wear at the tape edges, while adherent debris is related to tape binder system, and causes increases in drive error rate. Cleaning brushes have been incorporated into the design of drives to reduce the accumulation of all types of debris. A study was performed to determine the effectiveness of brushes on head surface cleaning. The use of brushes in drives was shown to be helpful in removal of both loose and adherent debris types. The effect of relative humidity at the interface was examined, and it was found that high relative humidity acts as a lubricant at the head–tape interface, helping to reduce tape wear. Low relative humidity can have differing effects on the interface performance, as it has shown to either increase or decrease debris accumulation, depending upon tape characteristics. 相似文献
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有机薄膜器件的镀膜自动控制系统设计 总被引:1,自引:1,他引:0
设计了用于有机薄膜器件的镀膜自动控制系统;整个自动控制系统以单片机为核心,可分为3个功能模块:人机交互、强弱电转换、样品处理。人机交互由单片机来实现;强弱电转换由固体继电器来完成;样品处理包括镀膜速率自动控制和样品保护两个部分。控制系统体现了弱电控制强电的设计思路,系统采用了单片机、继电器、电磁阀和可调变阻器等器件以及程控可调电阻电路。所设计的控制系统能克服目前有机薄膜器件镀膜系统的一些弊端,实现镀膜和镀膜速率的自动控制,并且能够避免有机半导体材料在真空腔内的相互污染。 相似文献
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移动车辆通过变截面连续箱梁桥的动力响应一般采用有限元数值计算程序进行分析,但其前后处理界面和图形功能微弱.针对这一情况,提出了混合编程方法,把Fortran语言强大的计算功能和Visual Basic语言良好的可视化界面设计功能结合起来,开发了桥梁动力响应有限元计算程序系统.系统不仅能解决复杂的工程问题,并且具有较好的人机交互界面.对系统开发过程中混合编程方面遇到的疑难问题进行阐述,给出了相应的解决方法. 相似文献