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An algorithm for compensation of short-period errors in optical encoders



Marcus H. Mendenhall, Donald A. Windover, Albert Henins, James P. Cline


We present a simple way to collect data from an optical position or angle encoder with a readout which interpolates values between the optical features, and to process this data set so as to determine the short-range errors which arise from an interpolation process. This is commonly known as the measuring the compensation function for such an encoder. This process allows the user of data from an encoder to make this correction without relying on un- documented internal algorithms which may be provided by the encoder manufacturer. It can also be used to test built-in algorithms by measuring the residual error when internal algorithms are used. We apply the algorithm to a commercial angular encoder, installed in a goniometer, as an example. The determination of this function on an encoder is critical to provable angle or position metrology efforts.


optical encoder, angular metrology


Mendenhall, M. , Windover, D. , Henins, A. and Cline, J. (2015), An algorithm for compensation of short-period errors in optical encoders, Metrologia, [online], (Accessed July 25, 2024)


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Created September 24, 2015, Updated November 10, 2018