Journal of Intelligent and Robotic Systems

, Volume 34, Issue 4, pp 415–430 | Cite as

Augmented Sliding Mode Control for Flexible Link Manipulators

  • David G. Wilson
  • Rush D. RobinettIII
  • Gordon G. Parker
  • Gregory P. Starr


A method of sliding mode control (SMC) is proposed for the control of flexible, nonlinear, and structural systems. The method departs from standard sliding mode control by dispensing with generalized accelerations during the control law design. Global, asymptotic stability of rigid body motion is maintained if knowledge on the bounds of the neglected terms exists. Furthermore, this method provides damping for the measured flexible body modes. This paper investigates an augmented SMC technique for slewing flexible manipulators. A conventional sliding surface uses a first order system including a combination of error and error rate terms. The augmented sliding surface includes an enhanced term that helps to reject flexible degrees-of-freedom. The algorithms are theoretically developed and experimentally tested on a slewing single flexible link robot. The test apparatus is instrumented with a strain gauge at the root and an accelerometer attached at the tip. A DC motor and encoder are used to servo the link from an initial position to a final position. A standard cubic polynomial is employed to generate the reference trajectories. The augmented SMC algorithm showed improved performance by reducing the flexible link tip oscillations.

flexible link sliding mode control manipulator 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Choi, S.-B., Cheong, C.-C., and Shin, H.-C.: Sliding mode control of vibration in a single-link flexible arm with parameter variations, J. Sound Vibration 179(5) (1995), 737–748.Google Scholar
  2. 2.
    Jalili, N., Elmali, H., Moura, J. T., and Olgac, N.: Tracking control of a rotating flexible beam using modified frequency-shaped sliding mode control, in: American Control Conference, Albuquerque, NM, 1997, pp. 2550–2556.Google Scholar
  3. 3.
    Kao, C. K. and Sinha, A.: Independent modal sliding mode control of vibration in flexible structures, J. Sound Vibration 147(2) (1991), 352–358.Google Scholar
  4. 4.
    Kao, C. K. and Sinha, A.: Sliding mode control of vibration in flexible structures using estimated states, in: Proc. of the 1991 American Control Conference, pp. 2467–2474.Google Scholar
  5. 5.
    Kao, C. K. and Sinha, A.: Coupled modal sliding mode control of vibration in flexible structures, AIAA J. Guidance Control Dyn. 15(1) (1992), 65–72.Google Scholar
  6. 6.
    Moallem, M., Khorasani, K., and Patel, R.V.: Inverse dynamics sliding control of flexible multilink manipulators, in: American Control Conference, Albuquerque, NM, 1997, pp. 1407–1416.Google Scholar
  7. 7.
    Moallem, M., Khorasani, K., and Patel, R. V.: Inversion-based sliding control of a flexible-link manipulator, Internat. J. Control 71(3) (1998), 477–490.Google Scholar
  8. 8.
    Oz, H. and Mostafa, O.: Variable structure control systems (VSCS) maneuvering of flexible spacecraft, J. Astronautical Sci. 36(3) (1988), 311–344.Google Scholar
  9. 9.
    Parker, G. G.: Control techniques for multibody flexible structures modelled by a method of quadratic modes, PhD Dissertation, State University of New York at Buffalo, April 1994.Google Scholar
  10. 10.
    Parker, G. G., Segalman, D. J., Robinett, R. D., and Inman, D. J.: Decentralized sliding mode control for flexible link robots, J. Intelligent Robotic Systems 17 (1996), 61–79.Google Scholar
  11. 11.
    Slotine, J. J. and Li, W.: Applied Nonlinear Control, Prentice-Hall, Englewood Cliffs, NJ, 1991.Google Scholar
  12. 12.
    Slotine, J. J. and Sastry, S. S.: Tracking Control of Nonlinear Systems Using Sliding Surfaces with Applications to Robot Manipulators, Internat. J. Control 38(2) (1983), 465–492.Google Scholar
  13. 13.
    Utkin, V. I.: Sliding Modes in Control Optimization, Springer, New York, 1981.Google Scholar
  14. 14.
    Utkin, V. I.: Variable structure systems with sliding modes, IEEE Trans. Automat. Control 22(2) (1977), 212–222.Google Scholar
  15. 15.
    Vidyasagar, M.: Nonlinear Systems Analysis, Prentice-Hall, Englewood Cliffs, NJ, 1978.Google Scholar
  16. 16.
    Watkins, J. and Yurkovich, S.: Vibration control for slewing flexible structures, in: Proc. of the 1992 American Control Conference, pp. 2525–2529.Google Scholar
  17. 17.
    Wilson, D. G.: Nonlinear/adaptive control architectures with active structures for flexible manipulators, PhD Dissertation, Mechanical Engineering Department, University of New Mexico, Albuquerque, NM, May 2000.Google Scholar
  18. 18.
    Wilson, D. G., Parker, G. G., Starr, G. P., and Robinett, R. D.: Modeling and robust control of a flexible manipulator, in: Proc. of the 11th VPI&;SU Symposium, Blacksburg, VA, 12–14 May 1997, pp. 523–532.Google Scholar
  19. 19.
    Wilson, D. G., Starr, G. P., Parker, G. G. and Robinett, R. D.: Robust control design for flexiblelink/ flexible joint robots, in: IEEE Internat. Conf. on Robotics and Automation, San Francisco, CA, April 2000, pp. 1496–1501.Google Scholar
  20. 20.
    Young, K.-K. D.: Variable Structure Control for Robotics and Aerospace Applications, Elsevier Science, Amsterdam, 1992, pp. 247–277.Google Scholar
  21. 21.
    Young, K.-K. D. and Drakunov, S. V.: Sliding mode control with chattering reduction, in: Proc. of the 1992 American Control Conference, pp. 1291–1292.Google Scholar
  22. 22.
    Yurkovich, S., Ozguner, U., and Al-Abass, F.: Model reference, sliding mode adaptive control for flexible structures, J. Astronautical Sci. 36(3) (1988), 285–310.Google Scholar

Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • David G. Wilson
    • 1
  • Rush D. RobinettIII
    • 1
  • Gordon G. Parker
    • 2
  • Gregory P. Starr
    • 3
  1. 1.Sandia National LaboratoriesAlbuquerqueU.S.A.
  2. 2.Michigan Technological UniversityHoughtonU.S.A
  3. 3.University of New MexicoAlbuquerqueU.S.A

Personalised recommendations