超高层建筑振动信号降噪算法研究

Study on denoising algorithm of improved wavelet packet threshold for processing the data in GNSS-RTK monitoring

针对超高层建筑振动信号往往被噪声干扰而导致真实位移难以显现,而常用的小波包软硬阈值函数,由于存在一定的缺陷无法较好地提取有用信号等问题,提出一种考虑调整系数的新阈值函数,该阈值函数介于软硬阈值函数之间。通过对仿真模拟信号与天津117大厦全球卫星导航系统(GNSS)实时动态差分(RTK)实测振动信号进行降噪处理,结果表明:小波包新阈值函数的信噪比、均方根误差、相关系数均优于软、硬阈值函数的降噪结果,并且117大厦实测信号的噪声也得到有效的抑制。

Aiming at the problem that the vibration signal of super high-rise building based on Global Navigation Satellite System(GNSS)Real Time Kinematic(RTK)technology is often disturbed by noise,which makes the real displacement difficult to appear,and the commonly used wavelet packet soft and hard threshold function cannot extract useful signals well due to some defects,a new threshold function considering adjustment coefficient is proposed,which is between soft and hard threshold function.The simulation signal and the vibration signal of Tianjin 117 building are processed by noise reduction.The results show that the signal-to-noise ratio,root mean square error and correlation coefficient of the new wavelet packet threshold function are better than those of the soft and hard threshold functions,and the noise of the measured signal of 117 buildings is also effectively suppressed.The new threshold function has good overall noise reduction effect and high engineering application significance.