Application Of Graphic Similarity's Principal To Shaft Centerline Orbit

The remote condition monitoring of great rotatory machinery should resolve the problem of date transmission first, and save useful data by selecting real time date, while Rotary machine run steadily, the shape of shaft centerline orbit has similarity, which usually change when fault occur,.In this paper guided by "intelligent monitor", we take the shaft centerline orbit as research object, apply similarity theory to it, point out that the similarity degree of shaft centerline orbit could be used as the monitor parameter, and play an important role in the remote condition monitoring. The major contents of the paper is as follows:(1) By analyzed the shape of orbit, we select vector as orbit composition element, so polygon is substituted for the orbit approximately, the similarity of the orbit change into the similarity of polygon; by use of technique of signals acquisition in a complete sampling period, vectors can be extracted from orbit,so a similar cell could be make up with two vectors which are periodic homologous.(2) Based on the similarity theory, we analyzed and defined the basic shape characteristic of the polygon,and made calculate formula for the similarity degree of the polygon. on the foundation of the calculate result, we presented the classification of shaft centerline orbit similarity ;(3) Finally we applied the similarity of shaft centerline orbit to the figure recognition of emulational signal and real signal, discussed the enactment of pre-alarm and main alarm of the similarity degree in remote condition monitoring , the result showed that this method of recognition is simple and effective ,.