Suppression of Vibrations Induced by Fluctuating Wind for Long-Span Cable-Stayed Bridge Using MR Dampers

2019 ◽  
Vol 24 (2) ◽  
pp. 262-270
Author(s):  
Zhao-Dong Xu ◽  
Meng Xu ◽  
Da-Huan Jia
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
State Control ◽  
Optimal Control Strategy ◽  
Box Girder ◽  
Mr Dampers ◽  
Cable Stayed Bridge ◽  
Long Span ◽  
Wind Induced Vibration ◽  
Fluctuating Wind

Cable-stayed bridges subjected to wind excitations will cause intense vibration due to their high flexibility in characteristic. Employment of magnetorheological (MR) dampers to realize the vibration smart-control of cablestayed bridges has become a considerable research topic in recent decades. In this paper, the plane truss finite element model (FEM) of a cable-stayed bridge with MR dampers is established. Fluctuating wind field is generated using the weighted amplitude wave superposition (WAWS) method and Kaimal spectrum, and then the time-history sample curve of wind speed is obtained. Fluctuating wind-induced vibration of the long-span cable-stayed bridge installed with MR dampers is analyzed by linear quadratic regulator (LQR) classical optimal control strategy and LQR tri-state control strategy. After the optimal control force is calculated by LQR classical optimal control strategy, control parameters and the input currents of MR dampers can be determined according to the windinduced vibration by LQR tri-state control. Results show that longitudinal and vertical wind-induced vibration responses of the box girder of the cable-stayed bridge are reduced obviously when MR dampers are arranged between the box girder and pylons.

Semi-Active Direct Velocity Control Method of Dynamic Response of Spatial Reticulated Structures Based on MR Dampers

2009 ◽  
Vol 12 (4) ◽  
pp. 547-558 ◽  
Author(s):  
Yan Bao ◽  
Cheng Huang ◽  
Dai Zhou ◽  
Yao-Jun Zhao
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Control Method ◽  
Optimal Placement ◽  
Feedback Gain ◽  
Control Force ◽  
Optimal Control Strategy ◽  
Integrated Method ◽  
Mr Dampers ◽  
Set Up

In this paper, a semi-active optimal control strategy for spatial reticulated structures (SRS) with MR dampers subjected to dynamic actions was proposed. The motion equation of SRS embedded with MR dampers was set up. The performance function of the optimal control strategy including both the structural responses and the control efforts was constituted for the optimization of feedback gain and MR damper placement in SRS, and an integrated method of genetic-gradient based algorithm was developed to solve this optimization problem. The clipped-optimal semi-active control strategy in the conjunction of velocity output feedback was applied to compute the desired control force from the MR dampers. Finally, a numerical example of SRS dealing with optimal placement of MR dampers and feedback gains of control system demonstrates the validity of the present semi-active optimal control strategy.

A Modified Optimal Control Strategy for a Five-Finger Robotic Hand

2014 ◽  
Vol 1 (1) ◽  
pp. 3-10 ◽  
Author(s):  
Cheng-Hung Chen ◽  
◽  
D. Naidu
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Robotic Hand ◽  
Optimal Control Strategy

Application of Optimal Control Strategy to Converter Gas Recovery System

2012 ◽  
Vol 38 (6) ◽  
pp. 1017 ◽  
Author(s):  
Jia-Yan ZHANG ◽  
Zhong-Hai MA ◽  
Xiao-Bin QIAN ◽  
Shao-Ming LI ◽  
Jia-Hong LANG
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Optimal Control Strategy ◽  
Gas Recovery ◽  
Recovery System ◽  
Converter Gas

scholarly journals Implementation of an optimal control strategy for a hydraulic hybrid vehicle using CMAC and RBF networks

2012 ◽  
Vol 19 (2) ◽  
pp. 327-334 ◽  
Author(s):  
A. Taghavipour ◽  
M.S. Foumani ◽  
M. Boroushaki
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Hybrid Vehicle ◽  
Optimal Control Strategy ◽  
Rbf Networks ◽  
Hydraulic Hybrid ◽  
Hydraulic Hybrid Vehicle

Optimal control strategy for cancer remission using combinatorial therapy: A mathematical model-based approach

2021 ◽  
Vol 145 ◽  
pp. 110789
Author(s):  
Parthasakha Das ◽  
Samhita Das ◽  
Pritha Das ◽  
Fathalla A. Rihan ◽  
Muhammet Uzuntarla ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Optimal Control ◽  
Control Strategy ◽  
Optimal Control Strategy ◽  
Combinatorial Therapy ◽  
Model Based ◽  
Cancer Remission

scholarly journals Development of an Optimal Start Control Strategy for a Variable Refrigerant Flow (VRF) System

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Yusung Lee ◽  
Woohyun Kim
Keyword(s):  
Optimal Control ◽  
Control Strategy ◽  
Predictive Performance ◽  
Building Energy ◽  
Data Driven ◽  
Energy Usage ◽  
Optimal Control Strategy ◽  
Save Energy ◽  
Time Required ◽  
Optimal Control Methods

In this study, an optimal control strategy for the variable refrigerant flow (VRF) system is developed using a data-driven model and on-site data to save the building energy. Three data-based models are developed to improve the on-site applicability. The presented models are used to determine the length of time required to bring each zone from its current temperature to the set point. The existing data are used to evaluate and validated the predictive performance of three data-based models. Experiments are conducted using three outdoor units and eight indoor units on site. The experimental test is performed to validate the performance of proposed optimal control by comparing between conventional and optimal control methods. Then, the ability to save energy wasted for maintaining temperature after temperature reaches the set points is evaluated through the comparison of energy usage. Given these results, 30.5% of energy is saved on average for each outdoor unit and the proposed optimal control strategy makes the zones comfortable.

scholarly journals Greedy control of cascading failures in interdependent networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malgorzata Turalska ◽  
Ananthram Swami
Keyword(s):  
Optimal Control ◽  
Complex Systems ◽  
Control Strategy ◽  
Cascading Failures ◽  
Optimal Control Strategy ◽  
Supercritical Regime ◽  
Interdependent Networks ◽  
Malicious Activity ◽  
Cross System ◽  
Made In

AbstractComplex systems are challenging to control because the system responds to the controller in a nonlinear fashion, often incorporating feedback mechanisms. Interdependence of systems poses additional difficulties, as cross-system connections enable malicious activity to spread between layers, increasing systemic risk. In this paper we explore the conditions for an optimal control of cascading failures in a system of interdependent networks. Specifically, we study the Bak–Tang–Wiesenfeld sandpile model incorporating a control mechanism, which affects the frequency of cascades occurring in individual layers. This modification allows us to explore sandpile-like dynamics near the critical state, with supercritical region corresponding to infrequent large cascades and subcritical zone being characterized by frequent small avalanches. Topological coupling between networks introduces dependence of control settings adopted in respective layers, causing the control strategy of a given layer to be influenced by choices made in other connected networks. We find that the optimal control strategy for a layer operating in a supercritical regime is to be coupled to a layer operating in a subcritical zone, since such condition corresponds to reduced probability of inflicted avalanches. However this condition describes a parasitic relation, in which only one layer benefits. Second optimal configuration is a mutualistic one, where both layers adopt the same control strategy. Our results provide valuable insights into dynamics of cascading failures and and its control in interdependent complex systems.

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