This article presents a high-bandwidth control design suitable for precision motion instrumentation. Iterative learning control (ILC), a feedforward technique that uses previous iterations of the desired trajectory, is used to leverage the repetition that occurs in many tasks, such as raster scanning in microscopy. Two ILC designs are presented. The first design uses the motion system dynamic model to maximize bandwidth. The second design uses a time-varying bandwidth that is particularly useful for nonsmooth trajectories such as raster scanning. Both designs are applied to a multiaxis piezoelectric-actuated flexure system and evaluated on a nonsmooth trajectory. The ILC designs demonstrate significant bandwidth and precision improvements over the feedback controller, and the ability to achieve precision motion control at frequencies higher than multiple system resonances.
D. A. Bristow et al., "High Bandwidth Control of Precision Motion Instrumentation," Review of Scientific Instruments, American Institute of Physics (AIP), Oct 2008.
The definitive version is available at http://dx.doi.org/10.1063/1.2980377
Mechanical and Aerospace Engineering
National Science Foundation (U.S.)
Keywords and Phrases
Adaptive Control; Feedforward; Iterative Methods; Learning Systems; Motion Control; Physical Instrumentation Control; Piezoelectric Actuators
Article - Journal
© 2008 American Institute of Physics (AIP), All rights reserved.