Papers Published

1. Scruggs, Jeffrey T. and Taflanidis, Alexandros A. and Iwan, Wilfred D., Nonlinear stochastic controllers for semiactive and regenerative structural systems, with guaranteed quadratic performance margins, Proceedings of 8th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA2006, vol. 2006 (2006), pp. 9 - .
   (last updated on 2007/04/09)

   Abstract:
   In many applications of vibration control, the circumstances of the application impose constraints on the energy available for the actuation of control forces. Semiactive dampers (i.e., viscous dampers with controllable coefficients) constitute the simplest example of such actuation in structural control applications. Regenerative Force Actuation (RFA) networks are an extension of semiactive devices, in which mechanical energy is first converted to electrical energy, which is then dissipated in a controllable resistive network. A fairly general class of semiactive and regenerative systems can be characterized by a differential equation which is bilinear (i.e., linear in state, linear in control input, but nonlinear in both). This paper presents a general approach to bilinear feedback control system design for semiactive and regenerative systems, which is analytically guaranteed to out-perform optimal linear viscous damping in stationary stochastic response, under the familiar Quadratic Gaussian performance measure. The design for full-state feedback and for the more practical case of noise-corrupted and incomplete measurements (i.e., output feedback) are separately discussed. Variants of the theory are shown to exist for other quadratic performance measures, including risk-sensitive and multi-objective frameworks. An illustrative application to civil engineering is presented. Copyright © 2006 by ASME.

   Keywords:
   Stochastic control systems;Nonlinear control systems;Quadratic programming;Vibration control;Constraint theory;Damping;Feedback control;