Influence of Subdivision Error of Encoder on Speed Stability of Telescopes

High-resolution encoders are the most used angular transducer for ground-based large aperture telescope. High-resolution encoders are realized by electronic subdivision. In order to analyze the effect of the subdivision error on the speed stability of the telescope, a differential velocity measurement equation with subdivision error was established. Based on the Fourier analysis method, the influence of the subdivision error on the velocity measurement was analyzed from the amplitude and frequency characteristics, and the results of the analysis were verified by experimental results. Finally, the influence of subdivision error on the speed stability of servo system was analyzed by simulation. The research results can provide theoretical basis for control system performance evaluation and error analysis, as well as control system design.