Skip to main content
Log in

Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator

  • Research Article
  • Published:
Frontiers of Mechanical Engineering Aims and scope Submit manuscript

Abstract

Most parallel manipulators have multiple solutions to the direct kinematic problem. The ability to perform assembly changing motions has received the attention of a few researchers. Cusp points play an important role in the kinematic behavior. This study investigates the cusp points and assembly changing motions in a two degrees of freedom planar parallel manipulator. The direct kinematic problem of the manipulator yields a quartic polynomial equation. Each root in the equation determines the assembly configuration, and four solutions are obtained for a given set of actuated joint coordinates. By regarding the discriminant of the repeated roots of the quartic equation as an implicit function of two actuated joint coordinates, the direct kinematic singularity loci in the joint space are determined by the implicit function. Cusp points are then obtained by the intersection of a quadratic curve and a cubic curve. Two assembly changing motions by encircling different cusp points are highlighted, for each pair of solutions with the same sign of the determinants of the direct Jacobian matrices.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

b 1, b 2, l 1, l 2 :

Geometric parameters of the manipulator under study

C i :

Coefficient of the quartic polynomial equation

f i :

Constraint equation of a non-redundant manipulator

g :

Reduced configuration space of a non-redundant manipulator

h, φ :

Pose coordinates of the moving platform of the manipulator under study

I, J :

Redefined variables of the quartic polynomial equation

J DKP :

Direct Jacobian matrix

J IKP :

Inverse Jacobian matrix

p, α :

Actuated joint coordinates of the manipulator under study

P, λ :

Redefined unknown variables

q :

Direct kinematic singularity loci in the joint space of a non-redundant manipulator

t 1, t 2 :

Output variables for a non-redundant manipulator

u :

Tangent-half-angle of φ

ρ 1, ρ 2 :

Input variables for a non-redundant manipulator

Δ:

Quartic discriminant

References

  1. Sun J, Shao L, Fu L F, Han X Y, Li S H. Kinematic analysis and optimal design of a novel parallel pointing mechanism. Aerospace Science and Technology, 2020, 104: 105931

    Article  Google Scholar 

  2. Zhang W X, Zhang W, Ding X L, Sun L. Optimization of the rotational asymmetric parallel mechanism for hip rehabilitation with force transmission factors. Journal of Mechanisms and Robotics, 2020, 12(4): 041006

    Article  Google Scholar 

  3. Merlet J P. Direct kinematics and assembly modes of parallel manipulators. The International Journal of Robotics Research, 1992, 11(2): 150–162

    Article  Google Scholar 

  4. Hunt K H. Structural kinematics of in-parallel-actuated robot-arms. Journal of Mechanisms, Transmissions, and Automation in Design, 1983, 105(4): 705–712

    Article  Google Scholar 

  5. Innocenti C, Parenti-Castelli V. Singularity-free evolution from one configuration to another in serial and fully-parallel manipulators. Journal of Mechanical Design, 1998, 120(1): 73–79

    Article  Google Scholar 

  6. Wenger P, Chablat D. Workspace and assembly modes in fully-parallel manipulators: a descriptive study. In: Lenarčič J, Husty M L, eds. Advances in Robot Kinematics: Analysis and Control. Dordrecht: Springer, 1998, 117–126

    Chapter  MATH  Google Scholar 

  7. Haug E J. Parallel manipulator domains of singularity free functionality. Mechanics Based Design of Structures and Machines, 2021, 49(5): 615–639

    Article  Google Scholar 

  8. Kong X W. Classification of 3-degree-of-freedom 3-UPU translational parallel mechanisms based on constraint singularity loci using Grobner cover. Journal of Mechanisms and Robotics, 2022, 14(4): 041010

    Article  Google Scholar 

  9. Altuzarra O, Petuya V, Urízar M, Hernández A. Design procedure for cuspidal parallel manipulators. Mechanism and Machine Theory, 2011, 46(2): 97–111

    Article  MATH  Google Scholar 

  10. Peidró A, García-Martínez A, Marín J M, Payá L, Gil A, Reinoso O. Design of a mobile binary parallel robot that exploits nonsingular transitions. Mechanism and Machine Theory, 2022, 171: 104733

    Article  Google Scholar 

  11. McAree P R, Daniel R W. An explanation of never-special assembly changing motions for 3–3 parallel manipulators. The International Journal of Robotics Research, 1999, 18(6): 556–574

    Article  Google Scholar 

  12. Zein M, Wenger P, Chablat D. Non-singular assembly-mode changing motions for 3-RPR parallel manipulators. Mechanism and Machine Theory, 2008, 43(4): 480–490

    Article  MATH  Google Scholar 

  13. Hernandez A, Altuzarra O, Petuya V, Macho E. Defining conditions for nonsingular transitions between assembly modes. IEEE Transactions on Robotics, 2009, 25(6): 1438–1447

    Article  Google Scholar 

  14. DallaLibera F, Ishiguro H. Non-singular transitions between assembly modes of 2-DOF planar parallel manipulators with a passive leg. Mechanism and Machine Theory, 2014, 77: 182–197

    Article  Google Scholar 

  15. Husty M L. Non-singular assembly mode change in 3-RPR-parallel manipulators. In: Kecskeméthy A, Müller A, eds. Computational Kinematics. Berlin: Springer, 2009, 51–60

    Chapter  Google Scholar 

  16. Caro S, Wenger P, Chablat D. Non-singular assembly mode changing trajectories of a 6-DOF parallel robot. In: Proceedings of ASME 2012 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. Chicago: ASME, 2012, 1245–1254

    Google Scholar 

  17. Husty M, Schadlbauer J, Caro S, Wenger P. The 3-RPS manipulator can have non-singular assembly-mode changes. In: Thomas F, Perez Gracia A, eds. Computational Kinematics. Dordrecht: Springer, 2014, 339–348

    Chapter  Google Scholar 

  18. Macho E, Petuya V, Altuzarra O, Hernandez A. Planning nonsingular transitions between solutions of the direct kinematic problem from the joint space. Journal of Mechanisms and Robotics, 2012, 4(4): 041005

    Article  Google Scholar 

  19. Bamberger H, Wolf A, Shoham M. Assembly mode changing in parallel mechanisms. IEEE Transactions on Robotics, 2008, 24(4): 765–772

    Article  Google Scholar 

  20. Peidró A, María Marín J, Gil A, Reinoso Ó. Performing nonsingular transitions between assembly modes in analytic parallel manipulators by enclosing quadruple solutions. Journal of Mechanical Design, 2015, 137(12): 122302

    Article  Google Scholar 

  21. Coste M, Chablat D, Wenger P. Nonsingular change of assembly mode without any cusp. In: Lenarčič J, Khatib O, eds. Advances in Robot Kinematics. Cham: Springer, 2014, 105–112

    Chapter  Google Scholar 

  22. Coste M, Wenger P, Chablat D. Hidden cusps. In: Lenarčič J, Merlet J P, eds. Advances in Robot Kinematics 2016. Cham: Springer, 2018, 129–138

    Chapter  Google Scholar 

  23. Moroz G, Rouiller F, Chablat D, Wenger P. On the determination of cusp points of 3-RPR parallel manipulators. Mechanism and Machine Theory, 2010, 45(11): 1555–1567

    Article  MATH  Google Scholar 

  24. Manubens M, Moroz G, Chablat D, Wenger P, Rouillier F. Cusp points in the parameter space of degenerate 3-RPR planar parallel manipulators. Journal of Mechanisms and Robotics, 2012, 4(4): 041003

    Article  Google Scholar 

  25. Thomas F. A distance geometry approach to the singularity analysis of 3R robots. Journal of Mechanisms and Robotics, 2016, 8(1): 011001

    Article  MathSciNet  Google Scholar 

  26. Salunkhe D H, Spartalis C, Capco J, Chablat D, Wenger P. Necessary and sufficient condition for a generic 3R serial manipulator to be cuspidal. Mechanism and Machine Theory, 2022, 171: 104729

    Article  Google Scholar 

  27. Salunkhe D, Capco J, Chablat D, Wenger P. Geometry based analysis of 3R serial robots. In: Altuzarra O, Kecskeméthy A, eds. Advances in Robot Kinematics 2022. Cham: Springer, 2022, 65–72

    Chapter  Google Scholar 

  28. Kohli D, Spanos J. Workspace analysis of mechanical manipulators using polynomial discriminants. Journal of Mechanisms, Transmissions, and Automation in Design, 1985, 107(2): 209–215

    Article  Google Scholar 

  29. Waldron K J, Hunt K H. Series-parallel dualities in actively coordinated mechanisms. The International Journal of Robotics Research, 1991, 10(5): 473–480

    Article  Google Scholar 

  30. Iqbal H, Khan M U A, Yi B J. Analysis of duality-based interconnected kinematics of planar serial and parallel manipulators using screw theory. Intelligent Service Robotics, 2020, 13(1): 47–62

    Article  Google Scholar 

  31. Macho E, Altuzarra O, Pinto C, Hernandez A. Transitions between multiple solutions of the direct kinematic problem. In: Lenarčič J, Wenger P, eds. Advances in Robot Kinematics: Analysis and Design. Dordrecht: Springer, 2008, 301–310

    Chapter  Google Scholar 

  32. Bohigas O, Henderson M E, Ros L, Manubens M, Porta J M. Planning singularity-free paths on closed-chain manipulators. IEEE Transactions on Robotics, 2013, 29(4): 888–898

    Article  Google Scholar 

  33. Urízar M, Petuya V, Altuzarra O, Macho E, Hernández A. Computing the configuration space for tracing paths between assembly modes. Journal of Mechanisms and Robotics, 2010, 2(3): 031002

    Article  Google Scholar 

  34. Thomas F, Wenger P. On the topological characterization of robot singularity loci. A catastrophe-theoretic approach. In: Proceedings of 2011 IEEE International Conference on Robotics and Automation. Shanghai: IEEE, 2011, 3940–3945

    Chapter  Google Scholar 

  35. Burnside W S, Panton A W. The Theory of Equations: With an Introduction to the Theory of Binary Algebraic Forms. 3rd ed. Dublin: Hodges, Figgis and Co., Ltd., 1892

    MATH  Google Scholar 

  36. Blinn J F. Quartic discriminants and tensor invariants. IEEE Computer Graphics and Applications, 2002, 22(2): 86–91

    Article  Google Scholar 

  37. Arikawa K. Kinematic analysis of mechanisms based on parametric polynomial system: basic concept of a method using Gröbner cover and its application to planar mechanisms. Journal of Mechanisms and Robotics, 2019, 11(2): 020906

    Article  Google Scholar 

  38. Gosselin C, Angeles J. Singularity analysis of closed-loop kinematic chains. IEEE Transactions on Robotics and Automation, 1990, 6(3): 281–290

    Article  Google Scholar 

Download references

Acknowledgements

The author’s contributions are as follows: Xu Pei was in charge of the whole trial; Chengwei Shen wrote the manuscript; Jingjun Yu assisted with sampling. The first author thanks Prof. Lubin Hang of Shanghai University of Engineering Science for his previous introduction on cusp points and singularity-free transitions between DKP solutions in parallel manipulators, which stimulated interest in this study. This research was partially supported by the National Natural Science Foundation of China (Grant Nos. U1813221 and 52075015).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Xu Pei.

Additional information

Conflict of Interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shen, C., Yu, J. & Pei, X. Cusp points and assembly changing motions in the PRR-PR-PRR planar parallel manipulator. Front. Mech. Eng. 18, 27 (2023). https://doi.org/10.1007/s11465-022-0743-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11465-022-0743-x

Keywords

Navigation