Fundamentals of Precision Positioning Control

Adaptive Robust Precision Control of Piezoelectric Positioning Stages

Positioning stages using piezoelectric stack actuator (PEA) have very high theoretical bandwidth and resolution. However, as the total length of travel increases, nonlinear dynamics due to inherent hysteresis starts to dominate. In this paper, we separate the fast and slow dynamics of the total displacement and propose a simple first-order model. By approximating the hysteresis mapping with sim...

Control of a long range high-precision positioning system

Among a variety of actuators, Lorentz actuators are often used as fine actuators in DSA systems under an environment where disturbances are expected at fine actuators’ base. Their advantage is that they show an almost ideal zero stiffness characteristics, which is that disturbances from bases do not transmit to the moving parts [1]. Such zero-stiffness DSA systems have been applied to wafer sca...

Motion Control and Precision Positioning in Vacuum Environments

Model Reference Control for Ultra - High Precision Positioning Systems

MODEL REFERENCE CONTROL FOR ULTRA-HIGH PRECISION POSITIONING SYSTEMS by Lan Yu Due to the increasing demands of high-density semiconductors, molecular biology, optoelectronics, and MEMS/NEMS in the past decades, control of ultra-high precision positioning using piezoelectricity has become an important area because of its high displacement resolution, wide bandwidth, low power consumption, and p...

Workshop on High Precision Positioning and Vibration Control

This talk considers optimal design of frame structures for vibration suppression. The H-infinity norm of the transfer function from disturbance sources to the displacement outputs, which we want to suppress, is adopted as the objective function to represent the magnitude of vibration transfer. The design parameters are the cross-sectional areas of frame members. For minimization of the H1 norm ...