Switching motor control: An integrated amplifier design for improved velocity estimation and feedback

In this paper we propose an integrated motion control architecture based on a full third order motor model. We investigate the advantages and feasibility of controlling a motor using very fast (MHz) switching using digital components in place of traditional amplifiers. A switching controller combines the current and encoder (position) feedback paths into a single loop, and a model based observer estimates the unsensed motor velocity. When compared to second order controllers built with traditional amplifiers, the proposed design promises increased performance, better efficiency, and improved velocity estimation. Recent advances in semiconductor technology facilitate the implementation of these fast switches and the required logic using relatively standard components. Preliminary experiments verify good behavior of a DC motor driven up to 5 MHz.