Papers by Author: S.R. Qin

Abstract: A new method for order tracking filtering of rotating machinery based on instantaneous frequency estimation and zero-phase distortion digital filtering is proposed. Compared with the traditional methods for order tracking filtering, the new method has a number of attractive features such as tacholess, no hardware-based tracking filter and no frequency shift to the original sampling data. The theorems and algorithms of the method are discussed. Filtering of overlapped data blocks, used to restrain the edge effect, which is caused by digital filtering, is introduced. An actual test example of run-up and coast down vibration of a motor is presented to demonstrate the validity of the method.

Abstract: A new nonlinear intensity interpolation algorithm is presented to realize sub-pixel edge detection. The interpolation algorithm based on the Canny criteria makes full use of grads information attained by Canny edge detection to perform special interpolation in the grads direction. When the resolution is enhanced, the interpolated image by the new interpolation scheme can efficiently preserve high frequency component in the original image. The edge detection of interpolated image permits high precision localization. The new interpolation algorithm is more effective in reserving the grads information of the step edge of the initial image than the usual linear interpolations. It requires simpler computation than the present non-linear interpolations.