An Improved Linearization Circuit Used for Optical Rotary Encoders
| Autor: | Dragan Denić, Jelena Jovanović, Uglješa Jovanović |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Rotary encoder
accuracy improvement Computer science 020208 electrical & electronic engineering 010401 analytical chemistry Biomedical Engineering linearization 02 engineering and technology Accuracy improvement 01 natural sciences 0104 chemical sciences analog-to-digital conversion Control and Systems Engineering Linearization Analog to digital conversion QA1-939 0202 electrical engineering electronic engineering information engineering Electronic engineering Instrumentation Mathematics angular position measurement |
| Zdroj: | Measurement Science Review, Vol 17, Iss 5, Pp 241-249 (2017) |
| ISSN: | 1335-8871 |
| DOI: | 10.1515/msr-2017-0029 |
| Popis: | Optical rotary encoders generate nonlinear sine and cosine signals in response to a change of angular position that is being measured. Due to the nonlinear shape of encoder output signals, encoder sensitivity to very small changes of angular position is low, causing a poor measurement accuracy level. To improve the optical encoder sensitivity and to increase its accuracy, an improved linearization circuit based on pseudo-linear signal generation and its further linearization with the two-stage piecewise linear analog-to-digital converter is presented in this paper. The proposed linearization circuit is composed of a mixed-signal circuit, which generates analog pseudo-linear signal and determines the first four bits of the final digital result, and the two-stage piecewise linear analog-to-digital converter, which performs simultaneous linearization and digitalization of the pseudo-linear signal. As a result, the maximal value of the absolute measurement error equals to 3.77168·10−5 [rad] (0.00216°) over the full measurement range of 2π [rad]. |
| Databáze: | OpenAIRE |
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