Observer-based friction compensation in heavy-duty parallel robot control

Sancak K. V., Bayraktaroğlu Z. Y.

Journal of Mechanical Science and Technology, vol.35, pp.3693-3704, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 35
  • Publication Date: 2021
  • Doi Number: 10.1007/s12206-021-0738-2
  • Journal Name: Journal of Mechanical Science and Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.3693-3704
  • Keywords: Dynamic friction, Friction identification, Parallel robot, Stewart-Gough platform, Extended state observer, Luenberger observer, INVERSE DYNAMICS, STATE OBSERVER, MOTION CONTROL, MODEL, SYSTEMS, DESIGN
  • Istanbul Technical University Affiliated: Yes


© 2021, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature.This paper presents an experimental study on friction compensation for the high-precision tracking control of parallel manipulators. A Luenberger-like observer (LLO) and an extended state observer (ESO) are designed and implemented in real-time control of a 6-DoF heavy-duty Stewart-Gough platform (SGP). The dynamic Lu-Gre model is used in the identification of friction. Performances of the proposed observer-based friction compensators are compared to those of a model-based compensator in computed torque control. Experimental results show that the observer-based compensators significantly improve the tracking performances in high speed motions. Among the investigated observers, the ESO results in minimum RMS error in position tracking. Improvement in position tracking at velocity reversals of the individual leg motions is also observed with the contribution of observer-based compensation. The observer error dynamics is exponentially stable, and the convergence rate can be arbitrarily increased by tuning the observer gain.