3-DOF Closed-Loop Control for Planar Linear Motors - Robotics Institute Carnegie Mellon University

3-DOF Closed-Loop Control for Planar Linear Motors

Conference Paper, Proceedings of (ICRA) International Conference on Robotics and Automation, Vol. 3, pp. 2488 - 2493, May, 1998

Abstract

Planar linear motors (Sawyer motors) have been used in industry as open-loop stepping motors, but their robustness and versatility has been limited. Using a sensor integrated into such a motor, a closed-loop 3-DOF controller has been implemented. The software-based control system consists of a commutator for computing amplifier currents from actuator forces, a force resolution function for solving the redundant actuation and saturation problems, and an observer for producing a velocity estimate, together with a PID controller. Experiments are performed using a 2-axis laser interferometer to show that the controller has sub-micron resolution, 2 /spl mu/m peak-to-peak repeatability, and settling times after trajectories of about 20 ms. Limitations of the PID controller are discussed and ideas for improvements are presented.

BibTeX

@conference{Quaid-1998-14642,
author = {Arthur Quaid and Ralph Hollis},
title = {3-DOF Closed-Loop Control for Planar Linear Motors},
booktitle = {Proceedings of (ICRA) International Conference on Robotics and Automation},
year = {1998},
month = {May},
volume = {3},
pages = {2488 - 2493},
}