dc.contributor.author	Elahinia, Mohammad	en
dc.contributor.committeechair	Ahmadian, Mehdi	en
dc.contributor.committeemember	Leo, Donald J.	en
dc.contributor.committeemember	Inman, Daniel J.	en
dc.contributor.committeemember	Nayfeh, Ali H.	en
dc.contributor.committeemember	Henneke, Edmund G. II	en
dc.contributor.committeemember	Baumann, William T.	en
dc.contributor.department	Mechanical Engineering	en
dc.date.accessioned	2011-08-22T19:02:57Z	en
dc.date.adate	2004-08-10	en
dc.date.available	2011-08-22T19:02:57Z	en
dc.date.issued	2004-07-20	en
dc.date.rdate	2004-08-10	en
dc.date.sdate	2004-08-09	en
dc.description.abstract	While the existing thermomechanical constitutive models can predict the behavior of SMA-actuated systems in most cases, in this study, we have shown that there are certain situations in which these models are not able to predict the behavior of SMAs. To this end, a rotary SMA-actuated robotic arm is modeled using the existing constitutive models. The model is verified against the experimental results to document that under certain conditions, the model is not able to predict the behavior of the SMA-actuated manipulator. Such cases most often occur when the temperature and stress of the SMA wire change simultaneously. The constitutive model discrepancy is also studied experimentally using a dead-weight that is actuated by an SMA wire. Subsequently, an enhanced phenomenological model is developed. The enhanced model is able to predict the behavior of SMAs under complex thermomechanical loadings. For the SMA-actuated robotic arm, several control methods are designed through simulations. A position-based PID controller is designed first, and it is found that this controller cannot perform well for all the desired angular positions(set-points). A Variable Structure Control (VSC) based on the angular position and velocity is presented that has a relatively better erformance for all the set-points. To improve the erformance of the VSC, in terms of the steady state error, an Extended Kalman Filter is designed and used to modify the VSC design. The modified VSC is based on the angular position and angular velocity of the actuator and the estimated temperature of the SMA wire. Furthermore, a Sliding Mode Controller is designed based on the stress of the SMA wire. Finally, a model-based Backstepping Controller is designed for the SMA-actuated arm. This model-bsed controller allows designing the controller parameters based on the parameters of the system. Additionally, the stability of the controller is studied. Using the Lyapunov stability analysis, it is shown that the model-based Backstepping Controller is able to asymptotically stabilize the system.	en
dc.description.degree	Ph. D.	en
dc.format.medium	ETD	en
dc.identifier.other	etd-08092004-112739	en
dc.identifier.sourceurl	http://scholar.lib.vt.edu/theses/available/etd-08092004-112739	en
dc.identifier.uri	http://hdl.handle.net/10919/11221	en
dc.publisher	Virginia Tech	en
dc.relation.haspart	abstract.pdf	en
dc.relation.haspart	contents.pdf	en
dc.relation.haspart	chapter_1_to_4.pdf	en
dc.relation.haspart	chapter_5_and_references.pdf	en
dc.relation.haspart	appendecies.pdf	en
dc.relation.haspart	vita.pdf	en
dc.relation.haspart	Title.pdf	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	Model-based Control	en
dc.subject	Control	en
dc.subject	Complex Thermomechanical Loadings	en
dc.subject	Shape Memory Alloy	en
dc.subject	Modeling	en
dc.title	Effect of System Dynamics on Shape Memory Alloy Behavior and Control	en
dc.type	Dissertation	en
thesis.degree.discipline	Mechanical Engineering	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Ph. D.	en

Effect of System Dynamics on Shape Memory Alloy Behavior and Control

Files

Original bundle

Collections