A Method for High Precision Spindle Motor Eccentricity Measurement

Measuring accurately the rotor eccentricity is important in the performance analysis and fault diagnosis of spindle motor. In this paper, a method based on vision technology is presented for measuring the eccentricity. In the measurement, an area of interesting (AOI) is selected and saved as template image. In the measurement procedure, the rotor image is captured and synchronized by spindle motor back-EMF zero crossing signals. A sub-pixel object detection algorithm is applied and the spindle motor eccentricity is can thus be calculated accurately. The experiments show that the resolution of the measurement can be better than 5 nanometers.