Spatial Filter Design for Dual-Stage Systems

Increasing demand for high precision positioning systems has motivated significant research in this field. Within this field, dual-stage nanopositioning systems have the unique potential to offer high-speed and long-range positioning by coupling a short-range, high-speed actuator with a long-range, low-speed actuator. In this paper, design considerations for a spatial filter are presented. The spatial filter allows for control allocation based on range of the signal as opposed to more commonly used frequency-based control allocation. In order to understand the spatial filtering approach more fully, this paper analyzes the filter in detail to understand limitations and give the user a more clear understanding of the approach. Simulation results are included to illustrate aspects of the discussion.