Campus Units

Civil, Construction and Environmental Engineering, Electrical and Computer Engineering, Center for Nondestructive Evaluation (CNDE)

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

2-2018

Journal or Book Title

Journal of Engineering Mechanics

Volume

144

Issue

2

First Page

04017174-1

Last Page

04017174-14

DOI

10.1061/(ASCE)EM.1943-7889.0001406

Abstract

High performance control systems (HPCS), including semiactive, active, and hybrid damping systems, are effective solutions to increase structural performance versus multihazard excitations. However, the implementation of HPCS within structural systems is still in its infancy, because of the complexity in designing a robust closed-loop control system that can ensure reliable and high mitigation performance. To overcome this challenge, a new type of controller with high adaptive capabilities is proposed. The control algorithm is based on real-time embedding of measurements to minimally represent the essential dynamics of the controlled system, therefore providing adaptive input space capabilities. This type of controller is termed an input-space dependent controller. In this paper, a specialized case of input-space dependent controller is investigated, where the embedding dimension is fixed, but the time delay used in the construction of the embedding varies with time. This constitutes a variable multidelay controller (VMDC), which includes an algorithm enabling the online selection of a time delay based on information theory. Here, optimal time delay selection is first studied and its applicability of the VMDC algorithm demonstrated. Numerical simulations are conducted on a single-degree-of-freedom (SDOF) system to study the performance of the VMDC versus different control strategies. Results show a significant gain in performance from the inclusion of an adaptive input space, and that the algorithm was robust with respect to noise. Simulations also demonstrate that critical gains in performance could be obtained from added knowledge in the system’s dynamics by comparing mitigation results with a linear quadratic regulator (LQR) controller. Additional simulations are conducted on a three degrees-of-freedom (3DOF) system, which consists of a model structure equipped with an actuator and subjected to nonsimultaneous multihazards. Results show enhanced mitigation performance of the VMDC versus LQR strategies when using limited-state feedback, validating the capability of the controller at mitigating vibrations based on limited knowledge and limited measurements, and thus its promise at multihazard applications.

Research Focus Area

Structural Engineering

Comments

This is a manuscript of an article published as Cao, Liang, and Simon Laflamme. "Real-Time Variable Multidelay Controller for Multihazard Mitigation." Journal of Engineering Mechanics 144, no. 2 (2017): 04017174. DOI: 10.1061/(ASCE)EM.1943-7889.0001406. Posted with permission.

Copyright Owner

American Society of Civil Engineers

Language

en

File Format

application/pdf

Published Version

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