EACS 2016 paper - LQR–UKF SEMI–ACTIVE CONTROL OF UNCERTAIN STRUCTURES
journal contributionposted on 2017-03-28, 15:17 authored by V.K. Dertimanis, E.N. Chatzi, F. Weber
EACS 2016 Paper No. 161
A novel semi-active control strategy for the effective vibration mitigation of structural systems of uncertain properties is introduced in this study. The implemented approach emerges through fusion of the Unscented Kalman filter (UKF), as a nonlinear observer, with the linear-quadratic regulator (LQR). The UKF is implemented towards the establishment of an adaptive joint state and parameter estimation problem, taking into account that numerical models of structural systems are often inadequate due to inherent uncertainties, such as noise and modeling errors, unknown system properties and influence of varying operational conditions. The improved state-space representation is accordingly fed into the LQR and a semi-active control scheme that utilizes clipping is applied. Since both estimation and control are executed within the same loop, particular attention is attributed to the derivation of the appropriate LQR strategy, pertaining to both the selection of optimal weight matrices and the real-time tuning of the control parameters. A simulated five-story shear-frame subject to earthquake motion serves as a case-study for validating the proposed methodology. The promising results encourage further investigation of the developed strategy, especially in regards to its real-time experimental implementation using semi-active actuators, such as magnetorheological dampers.