Analysis and experimental comparison of range-based control for dual-stage nanopositioners

In this paper, a novel range-based control algorithm for dual-stage nanopositioners is studied. Dual-stage nanopositioning systems have the powerful ability to achieve high-speed and long-range positioning by coupling a short-range, high-speed actuator with a long-range, low-speed actuator. One of the drawbacks of currently implemented control algorithms is that they tend to determine control allocation to the individual actuators based on the frequency of the desired motion. This can result in reduced positioning resolution and increased energy use, thus motivating this work on a control algorithm that considers range. The range-based algorithm allows the user to allocate control efforts to the individual actuators based on their range capabilities. This paper discusses the analysis, design, and implementation of the range-based control algorithm and highlights its benefits by experimentally comparing it to four other widely used dual-stage positioner control algorithms. Experimental results show that the method effectively splits control effort between the actuators based on range and results in reduced tracking error.