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
Copyright Owner
American Society of Civil Engineers
Copyright Date
2017
Language
en
File Format
application/pdf
Recommended Citation
Cao, Liang and Laflamme, Simon, "Real-Time Variable Multidelay Controller for Multihazard Mitigation" (2018). Civil, Construction and Environmental Engineering Publications. 145.
https://lib.dr.iastate.edu/ccee_pubs/145
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.