基于光纤陀螺与经验模态分解的航天器微小角振动检测技术

Detecting technique of spacecraft′s micro vibration based on FOG and EMD

航天器在轨运行过程中,由于内部多种活动部件的存在,会使其结构体产生振幅较小、频率较高的微小角振动,这会影响航天器有效载荷的正常工作。光纤陀螺作为航天器的姿态测量部件,在设计原理上具有高带宽的特点,针对航天器微小角振动的特点,提出采用光纤陀螺测量该振动信息,同时提出采用经验模态分解的方法将光纤陀螺输出信号分解成各个时间尺度上的本征模态函数,再经过Hilbert谱分析方法检测出微小角振动信息。通过星载测试试验对该方法进行了有效性验证,结果表明:采用经验模态分解技术能够实现航天器微小角振动信号的检测,为航天器微小角振动的高精度测量提供了新手段和新方法。

Due to the existing of various moving parts, the smaller amplitude and lower frequency will appear in the structure of spacecraft, when a spacecraft moving in orbit. This phenomenon will affect the inner payload. As an attitude measurement equipment of spacecraft, FOG obtains the characteristics of high bandwidth. Thus it was put forward that FOG can be adopted to measure the micro vibration. Moreover, EMD was adopted to decompose the output signal of FOG to intrinsic mode function on time scale as well. After that, Hilbert analysis method will be used to detect available micro vibration information. This method was tested in the spacecraft examination. The result shows that empirical mode decomposition technique could realize spacecraft＇s micro vibration, which brings a new method for the field of micro vibration measurement of spacecraft.