Hysteretic active control of base-isolated buildings

Summary A scalable optimal control method for structural vibration mitigation is studied. The method relies on a structure's partitioning that leads to a set of dynamically interconnected subsystems. Each subsystem is operated with an individual subcontroller that collects the local state information and collaborates with the neighboring subcontrollers to estimate a short time prediction of the interconnecting forces defining the subsystem's boundary conditions. Using the extended model that represents the subsystem's dynamics together with the evolution of its boundary conditions, each subcontroller computes the control decision based on the solution to a finite‐time horizon optimal control problem. In order to cope with the changes in the boundary conditions, the optimal solution is computed repetitively according to the receding horizon scheme. The method is validated numerically for a cantilever structure equipped with actively controlled electromagnetic actuators and subjected to a variety of initial condition scenarios. The performance of the designed controller is tested by comparisons to the centralized and isolated decentralized controllers. The introduced system partitioning and distributed controller allow performing parallel computing which makes the method fully scalable and applicable to large‐scale structures. The computational complexity of the designed distributed control is studied for different settings in the modeling of the subsystem's boundary conditions.

Section: Distributed Control Designmentioning

confidence: 99%

Scalable distributed optimal control of vibrating modular structures

Pisarski

Konowrocki

Jankowski

2020

“…A feedback control system considers measuring the structure's state variables to define actions taken by actuators that are placed at diverse locations of the structure to generate counterbalance forces attempting to keep the structure at its equilibrium point. A typical feedback in either classical or modern control strategy requires the interconnection from sensors to compute the control action for each actuator to effectively minimize the effects of vibrations in civil structures 1–3 . A recent life cycle cost evaluation of high‐performance control systems, including active and semi‐active systems, demonstrated the financial justification of the utilization of such systems despite the additional cost in installation and maintenance 4,5 .…”

Section: Introductionmentioning

confidence: 99%

Structural sparsity in control design of active and semi‐active systems

Florez

Giraldo

Soto

et al. 2021

Summary Civil building structures equipped with active or semi‐active control devices help mitigate structural damages in the presence of any seismic excitation. These advanced mitigation systems require additional devices such as sensors, actuators, and communication systems that increase issues related to energy consumption, measurement errors, and costs of implementation. In this work, we propose a methodology based on the concept of structural sparsity to induce a sparse pattern in the feedback control system that takes into account prior information on the inherent relationship between the variables of the controller. This methodology can potentially decrease the implementation costs while keeping a suitable performance of the structure when subjected to external disturbances. We show through mathematical analyses and simulation results the benefits of using the proposed methodology in both active and semi‐active systems.

“…Among various kinds of analysis methods of temperature effects, principal component analysis (PCA) was used frequently. [24][25][26] Torres-Arredondo et al [27] proposed an effective damage detection and temperature compensation approach by the combination of discrete wavelet transform, multiway principal component analysis, squared prediction error measures, and self-organizing maps. Cross et al [28] introduced a number of methodologies for dealing with the data collected from a Lamb-wave inspection of a composite panel.…”

mentioning

confidence: 99%

Ice monitoring of a full-scale wind turbine blade using ultrasonic guided waves under varying temperature conditions

Wang

Zhou

Bao

et al. 2018

Summary The icing of wind turbine blades is a common problem in cold climate area. Ice accretion on wind turbines, particularly turbine blades, can cause a variety of problems. The extreme icing may induce full stop of the turbine system. Thus, ice monitoring is one of the important issues for turbine blade icing solutions. The ice coating on the blade surface can change the primary propagation characteristics of the elastic waves. Therefore, Lamb waves are proposed to monitor the ice‐forming processes of a full‐scale wind turbine blade. Because the varying temperature is a remarkable and inevitably factor during ice monitoring, a principal component analysis (PCA)‐based ice monitoring method is proposed to eliminate the temperature effects and is first demonstrated by a segment of the blade in the laboratory. Subsequently, the proposed method is applied on a full‐scale blade in the frozen tunnel. The PZT wafers array is arranged to enhance the guided wave signals, and the tuning and attenuation characteristics are investigated on the clear surface of blade without ice. Finally, the PCA‐based method is used to identify the ice formation again on both the tip and the middle segments of the full‐scale blade under varying temperature conditions. The results indicate that the proposed ultrasonic guided wave combining PCA‐based method is efficient and sensitive for ice monitoring of the full‐scale wind turbine blade.