Evaluation Indices of Three Dimensional Measurement Signal Based on the Spectral Analysis upon Quaternion Signal Representation and the Concepts of Elliptical Movements

摘要

In this paper, we propose evaluation indices for grasping the characteristics of measurement signals from three axis sensors. Those evaluation indices are based on signal representation of quaternion and spectral analysis on the form. And, those are led by linking the coefficients of such spectra and the concept of the periodic motion on elliptic orbit in quaternion space. To show the benefit of the method in future use, an model experiment processing the three axis acceleration measurement data, which were recorded by originally developed sensor ball, were carried out. Then, the indices were calculated with the acceleration data given in such manner. As the result, comparing to the complex spectra at each axis, our evaluation indices have some advantages at the point of quick observation and recognition of three dimensional dynamical characteristics. Although the data processing based on quaternion has been widely used among the field of computer graphics or attitude control system of artificial satellite, a few attention are paid to the application for the signal processing of three dimensional measurement signal. On the other hand, in the field of the diagnostics with vibration such as of rotating machine, the spectral analysis which can observe a phase relation between multiple axis may become to be in great demand. So that, our evaluation indices will be a useful mean under such situation.