Abstract
It is well-known that structural mobility criteria, such as the Chebychev-Kutzbach–Grbler (CKG) formula, fail to correctly determine the mobility of mechanisms with special geometries. Even more, any known structural mobility criteria also fail to determine the generic (i.e. topological) mobility since they are prone to topological redundancies. A computational algorithm is proposed in this paper, which always finds the correct generic mobility of any planar and spherical mechanism. Its foundation is a novel representation of constraints by means of a constraint graph. The algorithm builds on the ‘pebble game’, originally developed within combinatorial rigidity theory for checking the rigidity of graphs. An extension of Laman’s theorem is introduced that enables application of the algorithm to any planar or spherical mechanism with higher and lower holonomic kinematic pairs and multiple joints. The novel algorithm further yields the redundantly constrained sub-linkages of a mechanism. In addition this algorithm naturally leads to a decomposition of a mechanism into Assur graphs, however this is beyond the scope of this paper.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Gogu, G.: Mobility of mechanism: a critical review. Mech. Mach. Theory 40, 1068–1097 (2005)
Jacobs, D. J., Hendrickson, B.: An algorithm for two-dimensional rigidity percolation: the pebble game. J. Comput. Phys. 137, 346–365 (1997)
Jain, A.: Graph theoretic foundations of multibody dynamics, Part I: structural properties. Multibody Syst. Dyn. 26, 307–333 (2011)
Laman, G.: On graphs and rigidity of plane skeletal structures. J. Eng. Math. 4, 331–340 (1970)
Lee, A., Streinu, I.: Pebble game algorithms and sparse graphs. Discret. Math. 308(8), 1425–1437 (2008)
Müller, A.: Generic mobility of rigid body mechanisms. Mech. Mach. Theory 44(6), 1240–1255 (2009)
Shai, O: Rigidity of 2d and 3d Pinned Frameworks and the Pebble Game, London. Mathematical Society Workshop: Rigidity of Frameworks and Applications, July 12–15, Lancaster University, England, (2010)
Shai, O., Sljoka, A., Whiteley, W.: Directed graphs, decompositions, and spatial rigidity. Discrete Appl. Math. Accepted 2012
Shai, O., Müller, A.: A novel combinatorial algorithm for determining the generic/topological mobility of planar and spherical mechanisms, In: ASME Design Engineering Technical Conferences, Portland, 12–15 Aug 2013
Sljoka, A.: Counting for Rigidity, Flexibility and extensions via the pebble game algorithm, Masters Thesis, York University 2006
Sljoka, A., Shai, O., Whiteley,W.: Checking mobility and decomposition of linkages via Pebble Game Algorithm, ASME Design Engineering Technical Conferences, In: Washington, USA, 28–31 Aug 2011
Tay, T.S.: Henneberg’s method for bar and body frameworks. Struct. Topology 17, 53–58 (1991)
Waldron, K.J.: The constraint analysis of mechanisms. J. Mech. 1, 101114 (1966)
Waldron, K.J.: A study of overconstrained linkage geometry by solution of closure equations Part I. Method of study. Mech. Mach. Theory 8, 95–104 (1973)
Waldron, K.J.: A study of overconstrained linkage geometry by solution of closure equations part II. Four-bar linkages with lower pairs other than screw joints. Mech. Mach. Theory 8, 23–324 (1973)
Wampler, C., Larson, B.T., Erdman, A.G.: A new mobility formula for spatial mechanisms, In: Proceeding ASME International Design Engineering Technical Conferences (IDETC), 47, Las Vegas, Sept (2007)
Wampler, C.W., Hauenstein, J.D., Sommese, A.J.: Mechanism mobility and a local dimension test. Mech. Mach. Theory 46, 1193–1206 (2011)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 Springer Science+Business Media Dordrecht
About this paper
Cite this paper
Shai, O., Müller, A. (2014). Computational Algorithm for Determining the Generic Mobility of Floating Planar and Spherical Linkages. In: Thomas, F., Perez Gracia, A. (eds) Computational Kinematics. Mechanisms and Machine Science, vol 15. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-7214-4_22
Download citation
DOI: https://doi.org/10.1007/978-94-007-7214-4_22
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-007-7213-7
Online ISBN: 978-94-007-7214-4
eBook Packages: EngineeringEngineering (R0)