Symmetry Constraint Inference in Assembly Planning - Automatic Assembly Configuration Specification

Yanxi Liu, Robin J. Popplestone

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Scopus citations


In this paper we shall discuss how to treat the automatic generation of assembly task specifications as a constraint satisfaction problem (CSP) over finite and infinite domains. Conceptually it is straightforward to formulate assembly planning in terms of CSP, however the choice of constraint representation and of the order in which the constraints are applied is nontrivial if a computationally tractable system design is to be achieved. This work investigates a subtle interaction between a pair of interleaving constraints, namely the kinematic and the spatial occupancy constraints. While finding one consistent solution to a general CSP is NP-complete, our work shows how to reduce the combinatorics in problems arising in assembly using the symmetries of assembly components. Group theory, being the standard mathematical theory of symmetry, is used extensively in this work since both robots and assembly components are threedimensional rigid bodies whose features have certain symmetries. This forms part of our high-level robot assembly task planner in which geometric solid modelling, group theory and CSP are combined into one computationally effective framework.

Original languageEnglish (US)
Title of host publicationProceedings of the 8th National Conference on Artificial Intelligence, AAAI 1990
PublisherAAAI press
Number of pages7
ISBN (Electronic)026251057X, 9780262510578
StatePublished - 1990
Event8th National Conference on Artificial Intelligence, AAAI 1990 - Boston, United States
Duration: Jul 29 1990Aug 3 1990

Publication series

NameProceedings of the 8th National Conference on Artificial Intelligence, AAAI 1990


Conference8th National Conference on Artificial Intelligence, AAAI 1990
Country/TerritoryUnited States

All Science Journal Classification (ASJC) codes

  • Artificial Intelligence
  • Software

Cite this