Title
Error Modeling And Improved Position Estimation For Optical Incremental Encoders By Means Of Time Stamping
Abstract
Optical incremental encoders are extensively used for position measurements in motion systems. The number of slits on the encoder disk defines the resolution of the encoder and bounds the accuracy of the position measurement. The encoder position measurements suffer from quantization errors. Moreover, encoder imperfections occur due to manufacturing tolerances. In this paper a method, which is based on time stamping, is proposed to obtain more accurate position and velocity estimations. Time stamping makes use of stored events, consisting of the encoder counts and their time instants, which are captured at a high resolution clock. Low order polynomial fitting through these encoder events is combined with active compensation of the encoder errors. The proposed method is applied in real-time experiments to a motion system. The results show an improvement in the position accuracy of up to 87% in terms of the maximum error. The estimated velocity is also much more accurate than the differentiated quantized encoder output signal.
Year
DOI
Venue
2007
10.1109/ACC.2007.4282443
2007 AMERICAN CONTROL CONFERENCE, VOLS 1-13
Keywords
DocType
ISSN
encoding,motion control systems,motion control,polynomials,quantization,high resolution,signal processing,switches,quantization error,sampling methods,real time
Conference
0743-1619
Citations 
PageRank 
References 
3
0.51
8
Authors
3
Name
Order
Citations
PageRank
Roel J. E. Merry151.22
r van de molengraft230.51
Maarten Steinbuch365896.53