Enhancing slow-sampled loops in input multi-rate digital tracking control systems: An overview

In error-based tracking control systems and reference signal tracking systems, the dynamic performance of slow-sampled loops is often inferior to that of fast-sampled loops. This paper focuses on the challenges encountered in such systems when performing error-based tracking tasks and reviews the methods proposed in the literature to address these issues. In particular, it examines how slow-sampled image sequences can be effectively treated as fast-sampled signals for closed-loop tracking, and how efficient and robust control strategies can be designed using slow-sampling sensor data. This paper provides an overview of the framework for input multi-rate digital tracking control systems and presents a comprehensive review, highlighting two research directions aimed at improving the performance of slow-sampled loops and addressing inherent challenges. Finally, it critically evaluates the applicability of these research directions and discusses their limitations as well as opportunities for future investigation.