Method for recovering dynamic position of photoelectric encoder
Yongzhi Wu, Qiuhua Wan, Changhai Zhao, Ying Sun, Lihui Liang, Yi‐Sheng Liu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2009
This paper presents a method to recover dynamic position of photoelectric encoder. While working at dynamic state, original outputs of the photoelectric encoder are in theory two sine or triangular signals with a phase difference of π/2. However, there are still deviations of actual output signals. Interpolating on the basis of this deviation signal will result in interpolation errors. In dynamic state, true original signal data obtained by data acquisition system is a time equation. Through processing these data by data equiangular and harmonic analysis, the equation will be converted from time domain to position domain and an original position equation can be formed. Then the interpolation errors also can be obtained. By this method, the interpolation errors can be checked in dynamic state and it can also provide electric interpolation basis so that to improve dynamic interpolation precision of the encoder. Software simulation and experimental analysis all prove the method effective. This method is the basis in theory for precision checking and calibration in motion.