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Combined direct and indirect adaptive control of constrained robots

Yu, H.; Lloyd, S.


S. Lloyd


The force tracking error is dependent on both the position tracking error and the estimated parameter error so that, in constrained adaptive robot control, the convergence of the estimated parameter error becomes more important than in unconstrained adaptive robot control. However, in the direct adaptive controller, the parameter adaptation is driven only by the tracking error in the joint motion, while in the indirect adaptive controller, the parameter estimation is driven only by the prediction error in the joint torque. Based on this observation a new combined direct and indirect adaptive controller driven by both the tracking error and the prediction error is developed for constrained robots with inertia parameter uncertainty. Stability of the combined adaptive controllers is established in the Lyapunov sense. The combined control improves both position and force tracking performance compared with direct adaptive control. The computer simulations are presented to demonstrate the proposed schemes.

Journal Article Type Article
Publication Date 1997-01
Deposit Date Jun 18, 2022
Journal International Journal of Control
Print ISSN 0020-7179
Electronic ISSN 1366-5820
Publisher Taylor & Francis
Peer Reviewed Peer Reviewed
Volume 68
Issue 5
Pages 955-970
Public URL