Measurement Error Analysis and Compensation for Optical Encoders: A Review

As a high-precision (HP) position sensor, the optical encoder is the core component of modern electromechanical machines. During measurement, it is inevitably influenced by different disturbances, which result in measurement errors that influence its measurement precision. This article summarizes several research topics on measurement errors of optical encoders, involving sources, control, and compensation of different types of measurement errors. First, the sources of measurement errors are summarized in detail, which is beneficial for purposeful designs of error control and compensation methods. Then, a large number of error control methods are surveyed and analyzed. After the survey, we find out that error control brings some additional costs, such as time costs and economical costs. Also, error compensation methods involving multierror compensation and hardware-based error compensation are summarized corresponding to different error sources. Finally, some potential research topics are provided.