共查询到15条相似文献,搜索用时 62 毫秒
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紧密结合智能信息化盾构施工辅助系统技术研究,将探地雷达这种高科技的无损探测方法应用到盾构开挖面的地质和障碍物情况探测中,在实验室通过模拟简单的地质情况进行障碍物和地质分层试验.并在盾构基地进行了现场试验,有力地证明了利用探地雷达进行盾构施工前方地质情况探测的可行性. 相似文献
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首次尝试将探地雷达方法应用到盾构前方地质情况的超前探测,并进行了模拟试验.通过分析试验结果,对探地雷达方法应用于探测盾构前方的地质状况的可行性进行探讨,也为进一步盾构施工的自动化、信息化提供一定依据. 相似文献
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为了实现利用探地雷达对盾构前向地质做出超前预报,规避盾构施工风险,选取适当的探地雷达中心频率及地质数据采集参数,对提高数据的可靠性和有效性极为重要.结合盾构施工要求,分析了探地雷达天线中心频率选择的主要影响因素,指出天线中心频率的选择既要满足对探测深度和分辨率的要求,又要满足其在盾构机上的安装情况.总结了探地雷达在盾构前向探测超前预报应用中地质数据采集参数设置的一些基本原则与技巧,分析了A/D采样位数、采集点数和扫描速率三者之间的关系. 相似文献
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中间层、平流层、对流层(Mesosphere - Stratosphere - Troposphere, MST)大气探测雷达在大气观测领域的应用越来越广泛,但其庞大的天线阵面尺寸给阵面布局、阵地基建和阵面电缆布线带来了很大挑战,也限制了该类型雷达的应用。文中从MST 雷达的天线阵面结构设计需求出发,针对高原地区环境特点,提出了一种新的天线阵面布局方案,并对天线阵地基建和天线阵面布线给出了详细设计方案,同时还设计了一种既满足电性能要求又适应高原环境的天线单元。通过对天线单元进行有限元力学仿真分析,验证了其结构设计的合理性。 相似文献
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探地雷达在盾构施工中的应用原理和实验分析研究 总被引:1,自引:1,他引:1
分析探地雷达圆周成像原理和特点,对实验测量数据进行了数字处理以及正演模型,验证探地雷达圆周测量障碍物和土质分层中的可行性和有效性,为盾构应用实时探测研究提供有益的探索. 相似文献
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文中提出了机动式雷达天线阵面结构正向设计方法,对雷达天线阵面进行了轻量化设计.应用经典力学求解天线阵面在静力学工况下的最大应力和变形,将此作为优化约束条件,将阵面质量作为优化目标,建立天线阵面的数学模型,用遗传算法进行第1次设计优化,得到天线阵面的初始结构参数综合考虑静力学工况与动力学工况,进一步用ANSYS系统的APDL建立参数化有限元模型,进行第2次优化,得到天线阵面的结构参数.文中对某型号的机动式雷达天线阵面进行了正向设计,并将优化结果与该雷达现有设计结果进行了分析对比.结果表明该正向设计方法合理,轻量化效果明显. 相似文献
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雷达是气象常用探测设备,其探测精度受气象条件的影响。本文分析了由大气参数引起的雷达探测误差,并根据实测数据进行了运算。希望对提高雷达测量精度有所帮助。 相似文献
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Carey M. Rappaport Michael B. Silevitch Stephen W. McKnight Charles A. DiMarzio Eric L. Miller Harold Raemer 《Subsurface Sensing Technologies and Applications》2001,2(3):215-230
The problem of detecting the many types of non-metallic land mines in the presence of widely varying soil background and irrelevant underground clutter is an example of one of the most difficult subsurface sensing problems. The application of a variety of different sensing techniques and modalities, and particularly the processing and fusing of the information from these sensors with signal-processing techniques that take account of the physical operating characteristics of each sensor, appears to be the way to make progress in such challenging applications. The progress of the Northeastern University multi-sensor demining effort funded through the Army Research Office's Multidisciplinary University Research Initiative is surveyed as an example of how this strategy can work. 相似文献
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Turbo-BLAST系统基于MMSE的迭代软干扰消除检测技术可有效克服由于V-BLAST的应用带来的多流干扰,但是在迭代检测译码过程中存在错误传播,并且收敛性较差,尤其在接收天线远小于发射天线时。而MAP迭代检测算法的性能接近最优,但复杂度随发射天线和调制阶数呈指数增长。所以本文把这两种算法相结合,提出改进的SIC-MAP/MMSE检测算法。仿真结果表明,在相同频谱利用率的条件下,这种新检测算法在性能和收敛性上明显优于MMSE的迭代软干扰消除(SIC-MMSE)检测技术。 相似文献
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《Measurement》2015
This paper presents a novel non-destructive method for termite detection that uses the entropy of the continuous wavelet transform of the acoustic emission signals as an uncertainty measurement, to achieve selective frequency separation in complex impulsive-like noisy scenarios, with the aid of the spectral kurtosis as a validating tool. The goal consists of detecting relevant frequencies, by looking up the minima in the curve associated to the entropy of the difference between the raw data and the wavelet-based reconstructed version. By measuring the signal’s uncertainty, the scales corresponding to the entropy minima, or pseudo-frequencies, manage to target three main types of emissions generated by termites: the modulating components (enveloping curve), the carrier signals (activity, feeding and excavating), and the communicating impulses bursts (alarms). The spectral kurtosis corroborates the location of the entropy minima (optimum uncertainty) matching them to its maxima, associated to frequencies with the highest amplitude variability, and consequently minimizing the measurement uncertainty. The method is primarily conceived to cover the acoustic-range, in order to acquire signals via standard sound cards; a broaden high-frequency study is developed for the assessment, and with the added value of discovering new and higher frequency components of the species emissions. The potential of the method makes it useful for myriads of applications in the frame of nondestructive transient detection. 相似文献