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Self-Motions of Planar Projective Stewart Gough Platforms

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Latest Advances in Robot Kinematics

Abstract

In this paper, we study self-motions of non-architecturally singular parallel manipulators of Stewart Gough type, where the planar platform and the planar base are related by a projectivity. By using mainly geometric arguments, we show that these manipulators have either so-called elliptic self-motions or pure translational self-motions. In the latter case, the projectivity has to be an affinity a+Ax, where the singular values s 1 and s 2 of the 2×2 transformation matrix A with 0<s 1s 2 fulfill the condition s 1≤1≤s 2.

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Notes

  1. 1.

    If κ is singular, one set of anchor points would collapse into a line or a point, which yields trivial cases of architecturally singular manipulators.

  2. 2.

    Neither all platform anchor points nor all base anchor points collapse into one point.

References

  1. Borel, E.: Mémoire sur les déplacements à trajectoires sphériques, Mém. présenteés par divers savants. Paris 33(2), 1–128 (1908)

    MathSciNet  Google Scholar 

  2. Bricard, R.: Mémoire sur les déplacements à trajectoires sphériques. J. Éc. Polytech. 11(2), 1–96 (1906)

    Google Scholar 

  3. Husty, M.: E. Borel’s and R. Bricard’s papers on displacements with spherical paths and their relevance to self-motions of parallel manipulators. In: Ceccarelli, M. (ed.) Int. Symp. on History of Machines and Mechanisms, pp. 163–172. Kluwer (2000)

    Google Scholar 

  4. Karger, A.: Architecture singular planar parallel manipulators. Mech. Mach. Theory 38(11), 1149–1164 (2003)

    Article  MATH  Google Scholar 

  5. Nawratil, G.: On the degenerated cases of architecturally singular planar parallel manipulators. J. Geom. Graph. 12(2), 141–149 (2008)

    MathSciNet  MATH  Google Scholar 

  6. Röschel, O., Mick, S.: Characterisation of architecturally shaky platforms. In: Lenarcic, J., Husty, M.L. (eds.) Advances in Robot Kinematics: Analysis and Control, pp. 465–474. Kluwer (1998)

    Google Scholar 

  7. Wohlhart, K.: From higher degrees of shakiness to mobility. Mech. Mach. Theory 45(3), 467–476 (2010)

    Article  MATH  Google Scholar 

  8. Chasles, M.: Sur les six droites qui peuvent étre les directions de six forces en équilibre. C. R. Séances Acad. Sci. 52, 1094–1104 (1861)

    Google Scholar 

  9. Karger, A.: Singularities and self-motions of a special type of platforms. In: Lenarcic, J., Thomas, F. (eds.) Advances in Robot Kinematics: Theory and Applications, pp. 155–164. Springer (2002)

    Google Scholar 

  10. Karger, A.: Singularities and self-motions of equiform platforms. Mech. Mach. Theory 36(7), 801–815 (2001)

    Article  MathSciNet  MATH  Google Scholar 

  11. Karger, A.: Parallel manipulators with simple geometrical structure. In: Ceccarelli, M. (ed.) Proc. of the 2nd European Conference on Mechanism Science, pp. 463–470. Springer (2008)

    Google Scholar 

  12. Mielczarek, S., Husty, M.L., Hiller, M.: Designing a redundant Stewart-Gough platform with a maximal forward kinematics solution set. In: Proc. of the International Symposion of Multibody Simulation and Mechatronics (MUSME), Mexico City, Mexico (2002)

    Google Scholar 

  13. Borras, J., Thomas, F., Torras, C.: Singularity-invariant leg rearrangements in doubly-planar Stewart-Gough platforms. In: Proc. of Robotics Science and Systems, Zaragoza, Spain (2010)

    Google Scholar 

  14. Nawratil, G.: Self-motions of planar projective Stewart Gough platforms, Technical Report No. 221, Geometry Preprint Series, TU Vienna (2011) www.geometrie.tuwien.ac.at/nawratil

  15. Husty, M.L., Karger, A.: Self motions of Stewart-Gough platforms: an overview. In: Gosselin, C.M., Ebert-Uphoff, I. (eds.) Proc. of the Workshop on Fundamental Issues and Future Research Directions for Parallel Mechanisms and Manipulators, pp. 131–141 (2002)

    Google Scholar 

  16. Nawratil, G.: Special cases of Schönflies-singular planar Stewart Gough platforms. In: Pisla, D., et al. (eds.) New Trends in Mechanisms Science, pp. 47–54. Springer (2010)

    Chapter  Google Scholar 

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Acknowledgements

This research is supported by Grant No. I 408-N13 of the Austrian Science Fund FWF within the project “Flexible polyhedra and frameworks in different spaces”, an international cooperation between FWF and RFBR, the Russian Foundation for Basic Research.

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Nawratil, G. (2012). Self-Motions of Planar Projective Stewart Gough Platforms. In: Lenarcic, J., Husty, M. (eds) Latest Advances in Robot Kinematics. Springer, Dordrecht. https://doi.org/10.1007/978-94-007-4620-6_4

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  • DOI: https://doi.org/10.1007/978-94-007-4620-6_4

  • Publisher Name: Springer, Dordrecht

  • Print ISBN: 978-94-007-4619-0

  • Online ISBN: 978-94-007-4620-6

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