Constant velocity control of a miniature pantograph with image based trajectory generation

Abstract

This paper presents a methodological approach for the practical realization of high precision laser micromachining over shapes of arbitrary geometry. The scheme presented throughout the paper includes an easy-to-use way of reference generation via image processing for shapes that is mathematically difficult to represent. The necessary constraint of tracking the constant reference tangential velocity for high precision laser production is enabled via the so called spline polynomial interpolation method. The description of algorithmic steps for the acquisition of reference cartesian trajectory from an image is followed by the presentation of spline method and the controller used for the realization. The proposed approach is tested in experiments and the validity of the methodology is verified for practical implementation.

Three-dimensional contour tracking control of a parallel manipulator: Comparison of two control techniques

“…Due to the finite number of data samples, by making use of the distances between points on the reference trajectory, one can only acquire segments with certain error bounds that are determined by the resolution of enhanced data. The results obtained using such an approach have been shown to perform successful in construction of the constant velocity trajectory profile [35]. However, further improvement of precision is possible if equation (26) can be implicitly solved and incorporated with an interpolation scheme within the constant length segmentation algorithm.…”

“…The points can be directly given from a CAD program, given in closed form representation [34] or can be obtained using some other techniques like acquiring via computer vision [35]. The discussion over the acquisition of trajectory is beyond the scope of this paper.…”