共查询到19条相似文献,搜索用时 515 毫秒
1.
2.
GPS高精度实时动态监测技术应用于大跨度桥梁监测成为获取桥梁运行状态和保障桥梁安全的重要手段,受到多种复杂因素的影响,如何提取大跨度桥梁的振动特性是该技术的关键.为了有效提取GPS桥梁振动特性,本文将处理时间观测序列十分优异的傅里叶分析应用于GPS桥梁监测数据处理,根据桥梁实际的振动特性有选择的去除不需要的频率,提取真实的桥梁振动特性.以正在实施监测的桥梁进行实验分析,证明了该方法的有效性,本文的研究为GPS桥梁动态监测数据分析提供了参考. 相似文献
3.
GPS结构振动监测数据滤波方法及其性能实验研究 总被引:2,自引:0,他引:2
使用GPS监测结构振动的目的在于提取振动信号特征,但GPS观测量受多种误差源的影响,因此,选用合理的数据处理方法有效地分离各误差项,对于提高GPS的监测精度具有重要意义。将Vondrak滤波、小波滤波、自适应FIR滤波和卡尔曼滤波等四种方法应用于资料序列中振动信号的分离,通过对模拟振动实验观测资料的分析表明:运用滤波法可提高GPS测量微小动态变形和变频振动信号的检测能力;4种滤波法均能有效地提高GPS监测结构振动的精度,其中,Vondrak滤波和小波滤波的性能相当,且优于自适应FIR和卡尔曼滤波。同时,在对各滤波法参数选择的优缺点进行分析的基础上,提出不同情况下选择滤波器的建议。 相似文献
4.
为了准确提取桥梁GNSS监测数据中的有效变形特征,本文充分发挥自适应噪声完备集合经验模态分解(Complete Ensemble Empirical Mode Decomposition with Adaptive Noise, CEEMDAN)与小波变换(Wavelet Transform, WT)在信号降噪中的优势,将二者结合进行桥梁GNSS监测数据降噪。首先通过CEEMDAN方法将原始监测数据分解为若干个本征模态函数(Intrinsic Mode Function, IMF),并通过相关系数识别出有效IMF分量,包含噪声的IMF分量以及无效IMF分量;其次使用WT软阈值降噪方法对包含噪声的IMF分量进一步降噪;最后重构降噪后IMF分量与有效IMF分量。通过仿真实验数据与苏通大桥实测GNSS数据对本文方法的有效性与优越性进行检验,结果表明,本文方法具有良好的降噪效果,能够有效提取桥梁的真实变形信息。 相似文献
5.
6.
《武汉大学学报(信息科学版)》2010,(9)
从模拟振动实验和工程实测两方面验证了高采样率GPS单历元定位技术是一种监测高层建筑风致振动的有效手段。应用小波对GPS观测的振动信号进行提取,结果表明,GPS能精确地观测到建筑物2mm的风致振动变形。 相似文献
7.
GPS变形监测系统中的监测点的观测资料是与时间有关的信号序列,本文研究应用小波分析优化流程,结合苏通大桥GPS变形监测系统获取的监测点数据序列进行分析。结果表明,选择合适的小波基函数,对数据信号进行小波分解与重构,可以有效地从受到强噪声干扰的监测数据序列中提取有用的特征信号,较好解决了传统处理技术对GPS动态观测数据去噪以及特征信息提取的局限性。 相似文献
8.
9.
10.
11.
12.
为了削弱结构动态监测中GPS随机噪声的影响,本文研究了一种基于集成经验模态分解(EEMD)技术的滤波方法。根据信号自身尺度分解信号,基于分解产生的本征模态函数(IMF)的Fourier变换频谱特征,构造了EEMD时空滤波器。对不同信噪比的仿真非平稳数据进行去噪处理并与小波去噪法相比较,各项指标表明基于EEMD滤波器的去噪方法与小波去噪方法效果相当,但避免了小波基的选择,具有更大的自适应性。应用于GPS动态监测数据的去噪结果表明该方法能有效分解信号消除GPS高频噪声及低频噪声的影响,提取有用振动信号,为进一步结构分析提供有效数据。 相似文献
13.
GPS变形监测系统中消除噪声的一种有效方法 总被引:21,自引:1,他引:21
GPS变形监测系统的观测资料可看成为与时间有关的数据序列,应用小波分析理论,研究了时间序列观测数据的误差消除问题。结果表明,借助于小波分解与重构,可有效地从强噪声干扰的观测数据序列中提取变形特征。该方法解决了传统处理技术对非平稳、非等时间间隔观测数据序列滤波的局限性问题。 相似文献
14.
15.
利用GPS测定大型桥梁动态特性的试验及结果 总被引:5,自引:1,他引:5
为研究GPS测定桥梁结构自振特性的可行性 ,结合武汉长江二桥开展了一次GPS动态监测试验工作 ,介绍了试验实施方案及其监测结果。通过应用频谱分析法 ,有效地获取了斜拉桥跨中的振动特征 ,其结果与竣工时采用加速度计实测的值十分吻合。研究表明 ,应用高采样率的GPS接收机和合理的数据处理方法 ,完全可以高精度地实现桥梁结构自振特性的确定 相似文献
16.
Multipath mitigation via component analysis methods for GPS dynamic deformation monitoring 总被引:1,自引:0,他引:1
Multipath is one of the main error sources in high-precision global positioning system (GPS) dynamic deformation monitoring, as it is difficult to be mitigated by differencing between observations. In addition, since a specific frequency threshold value between multipath and deformation signals may not exist, multipath is usually inseparable from the low-frequency vibration signal using conventional frequency-domain filter methods. However, the multipath repeats in two sidereal days when the surroundings of a GPS antenna remain unchanged. This characteristic can be exploited to model and thus mitigate multipath effectively in dynamic deformation monitoring. Unfortunately, a major issue is that the degree of repeatability decreases as the interval between first day and subsequent days increases. To overcome this problem, we develop a new sidereal filtering referred to as reference EMD-ICA (EMD-ICA-R), where empirical mode decomposition (EMD) and independent component analysis (ICA) are jointly used to model multipath and renew the reference multipath. For the successful implementation of the EMD-ICA-R, an a priori denoised multipath signal is needed as a reference. We further propose to use the principal component analysis (PCA) method to extract more accurate reference multipath signal and form a combined PCA-EMD-ICA-R approach. Simulation experiments with a motion simulation platform were conducted, and the testing results indicate that the proposed methods can mitigate the multipath by around 67 % when a reliable reference multipath signal is extracted from a static situation. Furthermore, simulation experiments with different deformation signals added into the coordinate time series of three consecutive days show that the two proposed methods are also effective in a dynamic situation. Since wavelet filtering is used to denoise the reference multipath signals in the new approaches, simulation experiments with several wavelet filters are tested, and the results indicate that the PCA-EMD-ICA-R approach can work well with various wavelet filters. 相似文献
17.
For the sake of timely appraising the working condition of the bridge, measuring the dynamic characteristics of the bridge structure is very important and necessary. A GPS dynamic monitoring test was carried out in the Wuhan Baishazhou Bridge, which is one of the longest span cable-stayed bridges having been built in China. This paper introduces the experimental implementing scheme and data processing method. The vibration characteristics of the middle span of cable-stayed bridge are availably obtained by use of the spectral analytic approach. The measuring results are very identical to the theoretical designed values. The research demonstrates that, with GPS receiver of the high sampling rate and suitable data processing method, the vibration characteristics of the bridge structure can be determined with high accuracy. 相似文献
18.
大跨度斜拉桥GPS动态监测试验及结果分析 总被引:4,自引:0,他引:4
为确保大桥建成后的安全运行,及时掌握桥梁结构的健康状况,避免出现灾难性的后果,有必要对桥梁结构的动态特性进行测定,以检验实测值与理论设计数值的偏差程度。结合武汉白沙洲大桥的GPS动态监测试验工作,介绍了试验实施方案及其数据处理过程。应用频谱分析法有效地确定了斜拉桥跨中的振动特征,其数值结果与理论设计值吻合较好。研究表明,高采样率GPS接收机与合适的数据处理方法相结合,可以有效地确定桥梁结构的自振特性。 相似文献