Improved Adaptive Inverse Compensation Technique for Real-Time Hybrid Simulation
Publication: Journal of Engineering Mechanics
Volume 138, Issue 12
Abstract
Real-time hybrid simulation provides an economical and efficient experimental technique for performance evaluation of structures under earthquakes. A successful real-time hybrid simulation requires accurate actuator control in order to achieve reliable experimental results. The time delay as a result of servohydraulic dynamics, if not compensated for properly, would lead to inaccurate or even unstable simulation results. However, the nonlinearities in servohydraulic systems and experimental substructures make the actuator delay difficult to accurately estimate in practice. Therefore, actuator control presents a challenge for the application of the real-time hybrid simulation technique to earthquake engineering research. This paper presents an improved adaptive inverse compensation technique for real-time hybrid simulation. Two adaptive control laws based on a synchronization subspace plot are introduced to adjust the compensation parameters in order to minimize both phase and amplitude errors in the servohydraulic actuator response. The improved adaptive inverse compensation method is experimentally evaluated through real-time tests involving a large-scale magneto-rheological damper subjected to band-limited white noise–generated random displacements and variable current inputs. The experimental results are compared with the command displacements, with the error assessed using various evaluation criteria. The improved adaptive inverse compensation is compared with an existing adaptive inverse compensation method to demonstrate the improvement that the newly developed compensation method offers in minimizing actuator delay. The proposed improved adaptive inverse compensation method is demonstrated to further improve actuator control by reducing not only actuator tracking errors but also associated energy errors.
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Acknowledgments
This paper is based upon work supported by grants from the Pennsylvania Department of Community and Economic Development through the Pennsylvania Infrastructure Technology Alliance and by the National Science Foundation under Grant No. CMS-0402490 within the George E. Brown, Jr., Network for Earthquake Engineering Simulation Consortium Operations and Grant No. CMMI-0830173. Any opinions, findings, and conclusions expressed in this paper are those of the authors and do not necessarily reflect the views of the sponsors. The MR fluid dampers were provided by Dr. Richard Christenson from the University of Connecticut. The authors appreciate his support.
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Information
Published In
Journal of Engineering Mechanics
Volume 138 • Issue 12 • December 2012
Pages: 1432 - 1446
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Jul 6, 2011
Accepted: Apr 9, 2012
Published online: Apr 12, 2012
Published in print: Dec 1, 2012
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