A systematic approach to determining the minimum sampling rate for real-time spacecraft control

Abstract

Typical controller design and analysis methods utilize techniques for continuous- time systems. However, digital computation is the favored approach to implement- ing the resulting controllers. This leads to the natural question of choosing an ap- propriate sampling rate for the controller. There exist several ”Rules of Thumbs” for choosing a sample rate derived from primarily frequency domain properties of the system. A metric to estimate the sample rate based on the system properties rooted from first principles is developed. It is then validated via several case stud- ies using representative mechanical systems, actuators, and controllers. Lastly, the paper concludes with a discussion on the applications of this metric.