Optical Angular Encoder Installation Error Measurement and Calibration by Ring Laser Gyroscope

This paper deals with the installation errors of an optical angular encoder (OAE). A harmonic model is proposed to describe the installation errors, including the effects of eccentricity, swash, and distortion. Moreover, a method of OAE calibration with the ring laser gyroscope (RLG) is introduced. The calibration method can potentially reach the accuracy of 0.1". The calibration method is proved to be experimentally effective. With the harmonic model obtained from the experiment, the calibration of the OAE can be carried out in real time.