A Nonlinear Optimal Control Design Using Narrowband Perturbation Feedback for Magnetostrictive Actuators
Publication Type:
Journal
Authors:
Co-Authors:
Zrostilk, R., Eichhorn, S., and Smith, R.
Year Published:
2010
Abstract:
Nonlinear optimal and narrowband feedback control designs are developed and
experimentally implemented on a magnetostrictive Terfenol-D actuator. The nonlinear optimal
control design incorporates a nonlinear and hysteretic ferromagnetic homogenized energy model
within an optimal control formulation to reduce displacement tracking errors and increase
bandwidth. Improvements in robustness in the steady-state regime are achieved by utilizing
narrowband feedback. A narrowband filter is implemented by treating the nonlinear and
hysteretic magnetostrictive constitutive behavior as higher-order harmonic disturbances which are
mitigated by tuning the narrowband filter to penalize these harmonics for displacement tracking
control problems. The control designs are then combined into a hybrid optimal controller with
perturbation narrowband feedback. Both transient and steady-state tracking control is assessed to
illustrate performance attributes in different operating regimes. Narrowband perturbation
feedback is shown to mitigate errors in the steady-state operating regime, while nonlinear optimal
control provides enhanced tracking control in the transient regime. The hybrid control design is
relevant to a broad number of smart material actuators that exhibit nonlinear and hysteretic fieldcoupled constitutive behavior.
Journal:
Journal of Intelligent Material Systems and Structures
Volume:
21
Issue:
16
Pagination:
1681-1693
ISSN:
Short Title:
Date Published:
12/1/2010