Motor control: Piezomotors get model-free adaptive control
In a close collaboration, model-free adaptive control (MFA) developer CyboSoft and nanoscale motion provider Physik Instrumente (PI) have developed the custom MFA Tiger controller for PI piezomotors, which the developers claim provides stable, smooth, fast and precise performance from start-up and under all operating conditions. Piezomotors have distinct advantages for driving small scale motion. Their compact size, high speed, responsiveness, non-magnetic nature, vacuum compatibility, sub-micron resolution, in-position stability and energy efficiency hold great promise for many demanding applications. They allow eliminating costly and bulky leadscrew and motor-coupling assemblies. Piezomotors’ varying dynamics and dead zones, however, can make them difficult to control.
The MFA Tiger controller’s special implementation of MFA control technology for plug-and-play closed-loop operation of ultrasonic piezomotors uses no servo tuning to provide automatic, real-time adaptation to changing loads and motor dynamics. It therefore eliminates the need for intensive servo setup as well as sensitivity to load. The developers say oscillation and runaway from mistuning are eliminated, and performance is quiet, smooth and precise even with changing loads.
— Edited by C.G. Masi , senior editor