A Wide-Range Velocity Measurement Method for Motion Control

TLDR

Velocity measurement for motor drives with optical encoders has been studied, but accurate high‑speed measurement remains challenging. The paper proposes a synchronous‑measurement (S) method that synchronizes velocity measurement with pulse‑number changes per sampling period. The S method synchronizes velocity measurement with pulse‑number changes per sampling period, and it can be combined with other velocity‑prediction techniques. Simulations and experiments confirm that the S method achieves accurate velocity measurement across all speed ranges.

Abstract

This paper discusses velocity measurement for motor drives with optical encoders. Although many methods on velocity measurement have been proposed, accurate measurement was not achieved in a high-speed range. This paper therefore proposes synchronous-measurement method (S method) that measures the velocity synchronized with the alteration of pulse numbers in each sampling period. Accurate velocity measurement is achieved in all speed ranges with this method. Furthermore, other velocity prediction methods are applicable in addition to the method. Simulation and experimental results verify the validity of the proposed method.