Evaluation of three optical-encoder-based speed estimation methods for motion control.

Autor: Yeny Vazquez-Gutierrez, Dara L. O'Sullivan, Richard C. Kavanagh
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: The Journal of Engineering (2019)
Druh dokumentu: article
ISSN: 2051-3305
DOI: 10.1049/joe.2018.8058
Popis: Three speed estimation methodologies: pulse count, elapsed time, and constant sample-time digital tachometer (CSDT) methods, used with optical incremental encoders, are implemented and compared in a closed-loop system setup using a specialised Analog Devices CM403f DSP. Dedicated hardware for quadrature encoders on the DSP facilitates the implementation of advanced speed estimation methods, such as the CSDT, by minimising the delay resulting from software intervention. The error of each methodology is evaluated theoretically and experimentally. The CSDT has limited error over all its speed range. The error of the elapsed time method increases as the speed increases. On the contrary, the relative error of the pulse count method (which is often substantial) decreases with increased speed. Several filtering techniques can be used to reduce the error of the elapsed time method; here an oversampling technique is implemented with that aim.
Databáze: Directory of Open Access Journals