English

Global rigidity of 2-dimensional linearly constrained frameworks

Combinatorics 2022-12-09 v2 Metric Geometry

Abstract

A linearly constrained framework in Rd\mathbb{R}^d is a point configuration together with a system of constraints which fixes the distances between some pairs of points and additionally restricts some of the points to lie in given affine subspaces. It is globally rigid if the configuration is uniquely defined by the constraint system, and is rigid if it is uniquely defined within some small open neighbourhood. Streinu and Theran characterised generic rigidity of linearly constrained frameworks in R2\mathbb{R}^2 in 2010. We obtain an analagous characterisation for generic global rigidity in R2\mathbb{R}^2. More precisely we show that a generic linearly constrained framework in R2\mathbb{R}^2 is globally rigid if and only if it is redundantly rigid and `balanced'. For generic frameworks which are not balanced, we determine the precise number of solutions to the constraint system whenever the underlying rigidity matroid of the given framework is connected. We also obtain a stress matrix sufficient condition and a Hendrickson type necessary condition for a generic linearly constrained framework to be globally rigid in Rd\mathbb{R}^d.

Keywords

Cite

@article{arxiv.1906.10926,
  title  = {Global rigidity of 2-dimensional linearly constrained frameworks},
  author = {Hakan Guler and Bill Jackson and Anthony Nixon},
  journal= {arXiv preprint arXiv:1906.10926},
  year   = {2022}
}

Comments

33 pages, 13 figures

R2 v1 2026-06-23T10:03:54.073Z