Digital image processing method for static balance measurement of incomplete spherical rotor with air suspension

Measurement and calibration of mass imbalance for rotors are often indispensible as mass imbalance will cause undesired vibration and present serious problems accordingly. In this study, a new method based on digital image processing (DIP) to measure the mass imbalance of a special rotor with air suspension is introduced. By hunting the trace of tilt angle through several identification points on the rotor by DIP, the corresponding oscillating period will be determined, which in turn contributes to the calculation of mass imbalance. Two-dimensional monochrome charge-coupled device (CCD) and peripheral component interconnect (PCI) image board are applied in the experiment to capture the rotor´s image, and several user interfaces are developed for image processing and curve fitting as well. Besides, the system error analysis and the comparison of experimental results with that of other related work are provided, which prove the effectiveness and accuracy of this DIP method.