Showing papers by "Chia-Hsiang Menq published in 2005"
TL;DR: In this article, a new six-axis magnetic suspension stage for precision motion control is presented, where a dynamic model of the feedback linearized and uncoupled stage is developed for the purpose of motion control.
Abstract: This work presents a newly developed six-axis magnetic suspension stage for precision motion control. The designed travel volume is 4/spl times/4/spl times/2 mm in translation and 1/spl deg//spl times/1/spl deg//spl times/2/spl deg/ in rotation. A dynamic model of the feedback linearized and uncoupled stage is developed for the purpose of motion control. Model parameter variations are demonstrated through closed-loop system identification. In motion control, a parameter variation model is proposed in conjunction with a reduced order observer to compensate the joined effect of disturbance, modeling error, and cross coupling. Experimental results in terms of positioning stability, motion resolution, rotational motion control, model regulation, large travel multiaxis contouring, and disturbance rejection are shown. Uniform positioning stability and invariant dynamic response within the designed travel volume are illustrated.
51 citations
TL;DR: A novel active visual measurement technique, laterally sampled white-light interferometry (L-SWLI), which is capable of real-time visual tracking of six-degree-of-freedom (6-DOF) rigid body motion with near-nanometer precision is presented.
Abstract: This paper presents the development of a novel active visual measurement technique, laterally sampled white-light interferometry (L-SWLI), which is capable of real-time visual tracking of six-degree-of-freedom (6-DOF) rigid body motion with near-nanometer precision. The visual tracking system is integrated with a 6-DOF motion stage to realize an ultraprecision six-axis visual servo-control system. Contrary to conventional interferometric techniques, L-SWLI obtains the complete pose of the target object from a single image frame, therefore allowing real-time tracking. Six-DOF motions are obtained from measuring the fringe pattern on multiple surfaces of the object or from a single surface with additional information gained from conventional image-processing techniques. The feasibility of the visually servoed motion scheme was demonstrated on a micro cantilever. The cantilever was maneuvered in a three-dimensional space with near-nanometer motion resolution in all three translational axes.
17 citations