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Backlash elimination in parallel manipulators using actuation redundancy

Published online by Cambridge University Press:  11 July 2011

Roger Boudreau ,
Xu Mao  and
Ron Podhorodeski
Roger Boudreau*
Affiliation:
Département de génie mécanique, Université de Moncton, Moncton, Nouveau-Brunswick, Canada
Xu Mao
Affiliation:
Robotics and Mechanisms (RAM) Laboratory, Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia, Canada
Ron Podhorodeski
Affiliation:
Robotics and Mechanisms (RAM) Laboratory, Department of Mechanical Engineering, University of Victoria, Victoria, British Columbia, Canada
*
*Corresponding author. E-mail: [email protected]
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Summary

In this work, accuracy enhancement through backlash elimination is considered. When a nonredundantly actuated parallel manipulator is subjected to a wrench while following a trajectory, required actuator torque switching (going from positive to negative or vice versa) may occur. If backlash is present in the actuation hardware for a manipulator, torque switching compromises accuracy. When in-branch redundant actuation is added, a pseudoinverse torque solution requires smaller joint torques, but torque switching may still occur. A method is presented where concepts of exploiting a nullspace basis of the joint torques are used to ensure that single sense joint torques can be achieved for the actuated joints. The same sense torque solutions are obtained using nonlinear optimization. The methodology is applied to several examples simulating parallel manipulators in machining applications.

Keywords

Actuation redundancyParallel manipulatorsBacklash eliminationOptimization
Type
Articles
Information
Robotica , Volume 30 , Issue 3 , May 2012 , pp. 379 - 388
Copyright
Copyright © Cambridge University Press 2011

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References

1.Kang, B. H., Wen, J. T.-Y., Dagalakis, N. G. and Gorman, J. J., “Analysis and design of parallel mechanisms with flexure joints,” IEEE Trans. Robot. 21 (6), 1179–1184 (2005).Google Scholar
2.Yi, B.-J., Chung, G. B., Na, H. Y., Kim, W. K. and Suh, I. H., “Design and experiment of a 3-DOF parallel micromechanism utilizing flexure hinges,” IEEE Trans. Robot. Autom. 19 (4), 604–612 (2003).Google Scholar
3.Pham, H. H. and Chen, I.-M., “Optimal Synthesis for Workspace and Manipulability of Parallel Flexure Mechanism,” Proceedings of the 11th World Congress in Mechanism and Machine Science, Tianjin, China (2004), 5p.Google Scholar
4.Müller, A., “Internal preload control of redundantly actuated parallel manipulators—Its application to backlash avoiding control,” IEEE Trans. Robot. 21 (4), 668–677 (2005).Google Scholar
5.Müller, A. and Maisser, P., “Generation and application of prestress in redundantly full-actuated parallel manipulators,” Multibody Syst. Dyn. 18 (2), 259–275 (2007).Google Scholar
6.Wei, W. and Simaan, N., “Design of planar parallel robots with preloaded flexures for guaranteed backlash prevention,” ASME J. Mech. Robot. 2, 011012 (2010).Google Scholar
7.Innocenti, C., “Kinematic clearance sensitivity analysis of spatial structures with revolute joints,” ASME J. Mech. Des. 124 (1), 52–57 (2002).Google Scholar
8.Parenti-Castelli, V. and Venanzi, S., “Clearance influence analysis on mechanisms,” Mech. Mach. Theory 40 (12), 1316–1329 (2005).CrossRefGoogle Scholar
9.Chebbi, A.-H., Affi, Z. and Romdhane, L., “Prediction of the pose errors produced by joint clearance for the 3-UPU parallel robot,” Mech. Mach. Theory 44 (9), 1768–1783 (2009).CrossRefGoogle Scholar
10.Gosselin, C. M. and Angeles, J., “Singularity analysis of closed-loop kinematic chains,” IEEE Trans. Robot. Autom. 6 (3), 282–290 (1990).CrossRefGoogle Scholar
11.Firmani, F. and Podhorodeski, R. P., “Force-unconstrained poses for a redundantly-actuated planar parallel manipulator,” Mech. Mach. Theory 39 (5), 459–476 (2004).Google Scholar
12.Firmani, F., Zibil, A., Nokleby, S. B. and Podhorodeski, R. P., “Force-moment capabilities of revolute jointed planar parallel manipulators, with additional branches,” Trans. Canadian Soc. Mech. Eng. 31 (4), 469–481 (2007).CrossRefGoogle Scholar
13.Zibil, A., Firmani, F., Nokleby, S. B. and Podhorodeski, R. P., “An explicit method for determining the force-moment capabilities of redundantly-actuated planar parallel manipulators,” ASME J. Mech. Des. 129 (10), 1046–1055 (2007).CrossRefGoogle Scholar
14.Ebrahimi, I., Carretero, J. A. and Boudreau, R., “3-PRRR redundant planar parallel manipulator: Inverse displacement, workspace and singularity analyses,” Mech. Mach. Theory 42 (8), 1007–1016 (2007).CrossRefGoogle Scholar
15.Merlet, J. P., “Redundant parallel manipulators,” J. Laboratory Robot. Autom. 8 (1), 17–24 (1996).3.0.CO;2-#>CrossRefGoogle Scholar
16.Ball, R. S., Theory of screws: A Treatise on the Theory of Screws (Cambridge University Press, New York, NY, USA, 1900).Google Scholar
17.Hunt, K. H., Kinematic Geometry of Mechanisms (Oxford University Press, Toronto, ON, Canada, 1978).Google Scholar
18.Craig, J. J., Introduction to Robotics: Mechanics and Control, 3rd ed. (Pearson Prentice Hall, Upper Saddle River, NJ, USA, 2005).Google Scholar
19.Strang, G., Linear Algebra and its Applications, 2nd ed. (Harcourt Brace, Orlando, FL, USA, 1988).Google Scholar
20.Wolfram MathWorld, http://mathworld.wolfram.com/LogarithmicSpiral.html (accessed Sep. 2010).Google Scholar
21.Gosselin, C. M., “Determination of the workspace of 6-DOF parallel manipulators,” ASME J. Mech. Des. 112 (3), 331–336 (1990).Google Scholar