Analysis of closed-loop systems involving hysteresis is important to both the understanding of these systems and the synthesis of control schemes. However, such analysis is challenging due to the nonsmooth nature of hysteresis nonlinearities. In this paper, singular perturbation techniques are employed to derive an analytical approximation to the tracking error for a system consisting of fast l...

This paper studies an enhanced dual-stage repetitive controller (RC) for improved robustness and tracking of periodic reference trajectories in piezo-based nanopositioning systems. The dual-stage RC system consists of a signal generator designed to provide high gain at the fundamental and all the harmonic frequencies of the reference trajectory and another that offers high gain only at the odd ...

This paper presents a novel sensing technique which uses a piezoelectric strain sensor for damping and accurate tracking of a nanopositioning stage. Piezoelectric elements have been used effectively as sensors for vibration control of smart structures. However, complications arise when one uses a piezoelectric strain sensor in a feedback loop for tracking. This is due to the high-pass character...

This paper deals with designing a repetitive controller (RC) for tracking periodic reference trajectories for systems that exhibit hysteresis, such as piezoelectric actuators used in nanopositioning systems. Hysteresis can drastically limit the performance of an RC designed around a linear dynamics model, and thus the effect of hysteresis on the closed-loop stability of RC is analyzed and the a...

Nanorobotics is currently a much studied field by the international scientific world. Numerous applications of nanorobotics make it to expand in several areas. This occurs through the integration of several disciplines, including nanofabrication processes used to produce nanorobots, nanoactuators, nano-sensors and nanometer scale physical modeling. Some of the most important applications of nan...

We propose an adaptive servocompensator utilizing frequency estimation and slow adaptation for systems subject to inputs of unknown frequencies.We show that the proposed controller can achieve zero tracking error for a class of periodic references and disturbances, including scenarios specifically relevant to piezo-actuated nanopositioning systems. In particular, for the case of a sinusoidal re...

This work deals with various investigations into the accuracy of a newly developed planar nanopositioning machine. machine, called Nanofabrication Machine 100 (NFM-100), has positioning range mm in diameter. To determine precision, movement scenarios are performed machine table, and trajectory deviation from set is determined. In particular, focus on high velocities up to 20 mm/s. Even at speed...

Micro-cantilevers with integrated heaters serve as powerful tools for investigation and manipulation at the nanometer scale. They can be used to locally heat surfaces. They can also serve as low-cost, highly integrable topography sensors, and find application as position sensors for nanopositioning applications. In this paper we present a tractable feedback model that captures the thermo-electr...