Abstract
The design and implementation of control strategies for large, flexible smart structures presents challenging problems. To demonstrate the capabilities of shape-memory-alloy actuators, we have designed and fabricated a three-mass test article with multiple shape-memory-alloy (NiTiNOL) actuators. The force and moment actuators were implemented on the structure to examine the effects of control structure interaction and to increase actuation force. These SMA actuators exhibit nonlinear effects due to dead band and saturation. The first step in the modeling process was the experimental determination of the transfer function matrix derived from frequency response data. A minimal state space representation was determined based on this transfer function matrix. Finally in order to reduce the order of the controller, a reduced order state space model was derived from the minimal state space representation. The simplified analytical models are compared with models developed by structural identification techniques based on vibration test data. From the reduced order model, a controller was designed to dampen vibrations in the test bed. To minimize the effects of uncertainties on the closed-loop system performance of smart structures, a LQG/LTR control methodology has been utilized. An initial standard LQG/LTR controller was designed; however, this controller could not achieve the desired performance robustness due to saturation effects. Therefore, a modified LQG/LTR design methodology was implemented to accommodate for the limited control force provided by the actuators. The closed-loop system response of the multiple input-multiple output (MIMO) test article with robustness verification has been experimentally obtained and presented in the paper. The modified LQG/LTR controller demonstrated performance and stability robustness to both sensor noise and parameter variations.
Recommended Citation
R. Lashlee et al., "Robust Control Of Flexible Structures Using Multiple Shape Memory Alloy Actuators," 1st IEEE Regional Conference on Aerospace Control Systems, AEROCS 1993 - Proceedings, pp. 798 - 804, article no. 721043, Institute of Electrical and Electronics Engineers, Jan 1993.
The definitive version is available at https://doi.org/10.1109/AEROCS.1993.721043
Department(s)
Electrical and Computer Engineering
Document Type
Article - Conference proceedings
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2023 Institute of Electrical and Electronics Engineers, All rights reserved.
Publication Date
01 Jan 1993
