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Article
Designing flexible manipulators with the lowest natural frequency nearly independent of position
International Conference on Robotics and Automation (1999)
  • Louis J. Everett, Texas A&M University
  • Jennchen Tang
  • Marc Compere
Abstract
Ideally, one would design a manipulator to be as rigid as possible. However there may be some occasions when the manipulator will be flexible. This will occur when the manipulator is very long and lightweight. Traditional flexible manipulators are difficult to control. This is because the manipulator has a nonlinear position variant behavior. Unfortunately using a large gear reduction does not reduce the nonlinearities in the flexible modes as it does in rigid manipulators. As a result, high performance controllers will inevitably be nonlinear themselves. To make matters worse, the parameters of the system are difficult to estimate so the control needs to be robust as well. The paper makes the point that rather than designing a controller that handles a complex system, one might build a flexible manipulator that exhibits simpler dynamic behavior than current designs. Specifically, the paper demonstrates how one can design a two dimensional flexible manipulator so that its fundamental vibration frequency is nearly independent of the rigid body position of the links. Analysis demonstrates the fundamental concept involved and experimental data verifies the analysis. What remains to be shown in future work are two points: 1) that a simple robust controller can damp the vibration of the mechanism; 2) that the extra complexity introduced by the new mechanism produces no overall negative effect.
Keywords
  • Frequency,
  • Vibrations,
  • Manipulator dynamics,
  • Control systems,
  • Robust control,
  • Mechanical engineering,
  • Robots,
  • Damping,
  • Gears,
  • Nonlinear dynamical systems,
  • manipulator dynamics,
  • flexible manipulators,
  • vibration control,
  • robust control
Disciplines
Publication Date
August 1, 1999
DOI
https://doi.org/10.1109/70.781964
Citation Information
Louis J. Everett, Jennchen Tang and Marc Compere. "Designing flexible manipulators with the lowest natural frequency nearly independent of position" International Conference on Robotics and Automation Vol. 15 Iss. 4 (1999) p. 605 - 611 ISSN: 1042-296X
Available at: http://works.bepress.com/marc_compere/33/