Accession Number:

ADA282854

Title:

Geometric Sensing of Known Planar Shapes

Descriptive Note:

Corporate Author:

CARNEGIE-MELLON UNIV PITTSBURGH PA ROBOTICS INST

Personal Author(s):

Report Date:

1994-07-01

Pagination or Media Count:

51.0

Abstract:

Industrial assembly involves sensing the pose orientation and position of a part. Efficient and reliable sensing strategies can be developed for an assembly task if the shape of the part is known in advance. In this paper we investigate two problems of determining the pose of a polygonal part of known shape. In the first problem, the part has a continuum of possible poses, while in the second problem, it has a finite number of possible poses. More specifically, the first problem involves determining the pose of a convex n-gon from a set of m supporting cones, that is, cones with both sides supporting the polygon. An algorithm with running time Onm which almost always reduces to On m log n is presented to solve for all possible poses of the polygon. As a consequence, the polygon inscription problem of finding all possible poses for a convex n-gon inscribed in another convex n-gon, can be solved within the same asymptotic time bound. We prove that the number of possible poses cannot exceed 6n, given m greater than or equal 2 supporting cones with distinct vertices. Experiments demonstrate that two supporting cones are sufficient to determine the real pose of the n-gon in most cases. Our results imply that sensing in practice can be carried out by obtaining viewing angles of a planar part at multiple exterior sites in the plane. As a conclusion, we generalize this and other sensing methods into a scheme named sensing by inscription

Subject Categories:

  • Cybernetics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE