基于多传感器的海洋平台动态位移监测及滤波方法

Study on methods of displacement filtering for an offshore platform by RTK-GNSS and accelerometer

针对采用全球卫星导航系统实时差分技术(RTK-GNSS)对海洋平台结构进行动态位移监测时,其监测数据存在噪声的问题,提出了一种基于巴特沃斯(Butterworth)和自适应噪声完备集合经验模态分解(CEEMDAN)的布特凯(BTCE)混合滤波算法,对监测数据进行滤波降噪处理,给出了BTCE滤波方法的基本思想并进行了实际验证。实测数据表明:BTCE滤波算法能有效地减弱噪声对RTK-GNSS海洋平台监测数据的影响,根据滤波后的RTK-GNSS数据,通过峰值法可以成功提取海洋平台的二阶固有自振频率,其结果与加速度计测量结果吻合较好,且RTK-GNSS无需积分可直接获取结构实时连续动态位移,这对研究平台结构的动态位移特点、交变振动响应规律和结构失效模式有一定的参考价值。

Pointing against the problem that the Real-Time Kinematic Global Navigation Satellite System(RTK-GNSS)has some background noise in the dynamic displacement monitoring data of offshore platforms,a hybrid filtering method named BTCE,which combines Butterworth method with Complete Ensemble Empirical Mode Decomposition with Adaptive Noise(CEEMDAN)decomposition,is proposed in this paper.This paper gives the basic idea of the method.It shows that BTCE can effectively reduce the background noise in the RTK-GNSS monitoring data.The filtered RTK-GNSS signal can successfully extract second-order natural vibration frequencies of the offshore platform through the peak method,and the results are in good agreement with the accelerometer measurement.Meanwhile,the real-time continuous dynamic displacement of structure can directly be obtained by RTK-GNSS without integration,which is of great significance to study the dynamic displacement characteristics,the alternating vibration responses and structural failure modes.