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

The Journal of Engineering

Dara L. O'Sullivan¹  Yeny Vazquez-Gutierrez²  Richard C. Kavanagh² 

[1] Analog Devices Inc;

[2] School of Engineering, University College Cork;

关键词: closed loop systems;    tachometers;    digital signal processing chips;    signal sampling;    motion control;    velocity control;    digital control;    filtering theory;    optical-encoder-based speed estimation methods;    motion control;    speed estimation methodologies;    constant sample-time digital tachometer methods;    CSDT;    optical incremental encoders;    quadrature encoders;    advanced speed estimation methods;    relative error;    pulse count method;    elapsed time method;    closed-loop system;    elapsed time;    specialised analogue devices CM403f DSP;    filtering techniques;    oversampling technique;    delay minimisation;    software intervention;    error reduction;   

DOI  :  10.1049/joe.2018.8058

来源: DOAJ

【 摘 要 】

Three speed estimation methodologies: pulse count, elapsed time, and constant sample-time digitaltachometer (CSDT) methods, used with optical incremental encoders, areimplemented and compared in a closed-loop system setup using a specialisedAnalog Devices CM403f DSP. Dedicated hardware for quadrature encoders on the DSPfacilitates the implementation of advanced speed estimation methods, such as theCSDT, by minimising the delay resulting from software intervention. The error ofeach methodology is evaluated theoretically and experimentally. The CSDT haslimited error over all its speed range. The error of the elapsed time methodincreases as the speed increases. On the contrary, the relative error of thepulse count method (which is often substantial) decreases with increased speed.Several filtering techniques can be used to reduce the error of the elapsed timemethod; here an oversampling technique is implemented with that aim.

【 授权许可】

Unknown