scholarly journals Exploring New Boundaries to Mitigate Structural Vibrations of Bridges in Seismic Regions: A Smart Passive Strategy

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Giuseppe Maddaloni ◽  
Nicola Caterino ◽  
Gianluca Nestovito ◽  
Antonio Occhiuzzi
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Design Procedure ◽  
Main Idea ◽  
Warning System ◽  
Semiactive Control ◽  
Dynamic Simulations ◽  
Seismic Engineering ◽  
Mr Dampers ◽  
Seismic Regions

The combined use of two emerging technologies in the field of seismic engineering is investigated. The first is a semiactive control, to reduce smartly the effects induced by earthquakes on structures. The second is the Seismic Early Warning System which allows an estimate of the Peak Ground Accelerations of an incoming earthquake. This paper proposes the exploitation of this information in the framework of a semiactive control strategy based on the use of magnetorheological (MR) dampers. The main idea consists of changing the MR dampers’ behaviour by the PGA estimated by the SEWS, to obtain the optimal seismic response of the structure. The control algorithm needed to drive the variable devices, according to the PGA estimate, is the core issue of the proposed strategy. It has been found that different characteristics of earthquakes that occur at different sites play a significant role in the definition of a control algorithm. Therefore, a design procedure for “regional” control algorithms has been performed. It is based on the results of several nonlinear dynamic simulations performed using natural earthquakes and on the use of a multicriteria decision-making procedure. The effectiveness of the proposed control strategy has been verified with reference to a highway bridge and to two specific worldwide seismic regions.

scholarly journals APPLICATION OF ADAPTIVE WAVELET NETWORKS FOR VIBRATION CONTROL OF BASE ISOLATED STRUCTURES

2010 ◽  
Vol 08 (05) ◽  
pp. 773-791 ◽  
Author(s):  
HAMID REZA KARIMI ◽  
MAURICIO ZAPATEIRO ◽  
NINGSU LUO
Keyword(s):  
Control Strategy ◽  
Supervisory Control ◽  
Feedback Linearization ◽  
Semiactive Control ◽  
Adaptive Wavelet ◽  
Wavelet Networks ◽  
Mr Dampers ◽  
Adaptive Laws ◽  
Adaptive Control Strategy ◽  
And Control

This paper presents an application of wavelet networks (WNs) in identification and control design for a class of structures equipped with a type of semiactive actuators, which are called magnetorheological (MR) dampers. The nonlinear model is identified based on a WN framework. Based on the technique of feedback linearization, supervisory control and H∞ control, an adaptive control strategy is developed to compensate for the nonlinearity in the structure so as to enhance the response of the system to earthquake type inputs. Furthermore, the parameter adaptive laws of the WN are developed. In particular, it is shown that the proposed control strategy offers a reasonably effective approach to semiactive control of structures. The applicability of the proposed method is illustrated on a building structure by computer simulation.

scholarly journals Research on Vibration Reduction Control Based on Reinforcement Learning

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Rongyao Yuan ◽  
Yang Yang ◽  
Chao Su ◽  
Shaopei Hu ◽  
Heng Zhang ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Control Strategy ◽  
Frame Structure ◽  
Semiactive Control ◽  
Damping Force ◽  
Mr Dampers ◽  
Damping Control ◽  
Optimal Damping ◽  
Optimal Value ◽  
Optimal Action

Magnetorheological (MR) dampers, as an intelligent vibration damping device, can quickly change the damping size of the material in milliseconds. The traditional semiactive control strategy cannot give full play to the ability of the MR dampers to consume energy and reduce vibration under different currents, and it is difficult to control the MR dampers accurately. In this paper, a semiactive control strategy based on reinforcement learning (RL) is proposed, which is based on “exploring” to learn the optimal value of the MR dampers at each step of the operation, the applied current value. During damping control, the learned optimal action value for each step is input into the MR dampers so that they provide the optimal damping force to the structure. Applying this strategy to a two-layer frame structure was found to provide more accurate control of the MR dampers, significantly improving the damping effect of the MR dampers.

scholarly journals Optimal Allocation and Control of Magnetorheological Dampers for Enhancing Seismic Performance of the Adjacent Structures Using Whale Optimization Algorithm

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xiufang Lin ◽  
Weiqing Lin
Keyword(s):  
Seismic Performance ◽  
Optimization Algorithm ◽  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Optimal Allocation ◽  
Whale Optimization Algorithm ◽  
Semiactive Control ◽  
Mr Dampers ◽  
Adjacent Structures ◽  
Whale Optimization

The control strategy for protecting adjacent structures from earthquake excitations is gaining increasing significance. In this study, to improve the seismic performance, a semiactive control strategy using magnetorheological (MR) dampers to couple the adjacent structures is proposed. In this control strategy, to fully exploit the performance of MR dampers, the allocation (including the locations and the number) and fuzzy logic controller (FLC) system of MR dampers are simultaneously optimally designed by whale optimization algorithm (WOA) with a special encoding scheme. Simulation results verify that WOA provides competitive performance compared with the other three metaheuristic algorithms in terms of solution quality and robustness. Compared with other semiactive control methods including on-off, linear quadratic regulator-clipped voltage law, and WOA-FLC (optimal allocation is not considered) methods, by using much less MR dampers, the proposed control strategy can exhibit more excellent overall performance in terms of reducing the seismic responses and mitigating pounding.

scholarly journals Application of Support Vector Machine-Based Semiactive Control for Seismic Protection of Structures with Magnetorheological Dampers

2012 ◽  
Vol 2012 ◽  
pp. 1-18
Author(s):  
Chunxiang Li ◽  
Qing Liu ◽  
Shengning Lan
Keyword(s):  
Support Vector Machine ◽  
Control Strategy ◽  
Control Strategies ◽  
Seismic Protection ◽  
Support Vector ◽  
Semiactive Control ◽  
Mr Dampers ◽  
Acceleration Amplification ◽  
Switch Control ◽  
Lqr Controller

Based on recent research by Li and Liu in 2011, this paper proposes the application of support vector machine- (SVM-) based semiactive control methodology for seismic protection of structures with magnetorheological (MR) dampers. An important and challenging task of designing the MR dampers is to develop an effective semiactive control strategy that can fully exploit the capabilities of MR dampers. However, amplification of the local acceleration response of structures exists in the widely used semiactive control strategies, namely “Switch” control strategies. Then the SVM-based semiactive control strategy has been employed to design MR dampers. Firstly, the LQR controller for the numerical model of a multistory structure formulated using the dynamic dense method is constructed by using the classic LQR control theory. Secondly, an SVM model which comprises the observers and controllers in the control system is designed and trained to emulate the performance of the LQR controller. Finally, an online autofeedback semiactive control strategy is developed by resorting to SVM and then used for designing MR dampers. Simulation results show that the MR dampers utilizing the SVM-based semiactive control algorithm, which eliminates the local acceleration amplification phenomenon, can remarkably reduce the displacement, velocity, and acceleration responses of the structure.

Speed regulation control of tractors’ new dual-flow transmission system based on slip rate resistance classification

2021 ◽  
pp. 095440702110105
Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun
Keyword(s):  
Control Strategy ◽  
Control Algorithm ◽  
Production Efficiency ◽  
Sliding Mode ◽  
Slip Rate ◽  
Speed Control ◽  
Working Environment ◽  
Vehicle Speed ◽  
Speed Change ◽  
Simulation Results

Fluctuations in operation resistance during the operating process lead to reduced efficiency in tractor production. To address this problem, the project team independently developed and designed a new type of hydraulic mechanical continuously variable transmission (HMCVT). Based on introducing the mechanical structure and transmission principle of the HMCVT system, the priority of slip rate control and vehicle speed control is determined by classifying the slip rate. In the process of vehicle speed control, the driving mode of HMCVT system suitable for the current resistance state is determined by classifying the operation resistance. The speed change rule under HMT and HST modes is formulated with the goal of the highest production efficiency, and the displacement ratio adjustment surfaces under HMT and HST modes are determined. A sliding mode control algorithm based on feedforward compensation is proposed to address the problem that the oil pressure fluctuation has influences on the adjustment accuracy of hydraulic pump displacement. The simulation results of Simulink show that this algorithm can not only accurately follow the expected signal changes, but has better tracking stability than traditional PID control algorithm. The HMCVT system and speed control strategy models were built, and simulation results show that the speed control strategy can restrict the slip rate of driving wheels within the allowable range when load or road conditions change. When the tractor speed is lower than the lower limit of the high-efficiency speed range, the speed change law formulated in this paper can improve the tractor speed faster than the traditional rule, and effectively ensure the production efficiency. The research results are of great significance for improving tractor’s adaptability to complex and changeable working environment and promoting agricultural production efficiency.

The Research of Air Precooling System Based on Generalize Predictive Control Strategy

2013 ◽  
Vol 433-435 ◽  
pp. 1091-1098
Author(s):  
Wei Bo Yu ◽  
Cui Yuan Feng ◽  
Ting Ting Yang ◽  
Hong Jun Li
Keyword(s):  
Predictive Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Exchange Process ◽  
Generalized Predictive Control ◽  
Matlab Simulation ◽  
Control Effect ◽  
Heat Exchange Process ◽  
Complex Control System ◽  
And Control

The air precooling system heat exchange process is a complex control system with features such as: nonlinear, lag and random interference. So choose Generalized Predictive Control Algorithm that has low model dependence, good robustness and control effect, as well as easy to implement. But due to the large amount of calculation of traditional generalized predictive control and can't juggle quickness and overshoot problem, an improved generalized predictive control algorithm is proposed, then carry out the MATLAB simulation, the experimental results show that the algorithm can not only greatly reduce the amount of computation, but also can restrain the overshoot and its rapidity.

The Study of Control Strategy for Sensor-Less PMSM

2014 ◽  
Vol 1006-1007 ◽  
pp. 575-580
Author(s):  
Qing Xie Chen ◽  
Jing Jing Chen ◽  
Yi Biao Fan
Keyword(s):  
Control System ◽  
Permanent Magnet ◽  
High Precision ◽  
Control Strategy ◽  
Control Algorithm ◽  
Simulation Experiment ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Single Chip

Targeting development of control system of a permanent magnet synchronous motor applied to high precision requirement, A strategy is researched to develop a single chip with built-in sensor-less control algorithm which is used as the control core of PMSM control system, the composition of the hardware and the realization of software of the chip are designed, and the simulation experiment is carried out to verify feasibility and rationality of the control strategy as well.

Adding realism to simulated sensors and actuators

2008 ◽  
Vol 57 (3) ◽  
pp. 337-344 ◽  
Author(s):  
C. Rosen ◽  
L. Rieger ◽  
U. Jeppsson ◽  
P. A. Vanrolleghem
Keyword(s):  
Wastewater Treatment ◽  
Markov Chains ◽  
Control Strategy ◽  
Strategy Development ◽  
Actuator Faults ◽  
Paper Briefly ◽  
Sensors And Actuators ◽  
Dynamic Simulations ◽  
Actuator Dynamics ◽  
Significant Obstacle

In this paper, we propose a statistical theoretical framework for incorporation of sensor and actuator faults in dynamic simulations of wastewater treatment operation. Sensor and actuator faults and failures are often neglected in simulations for control strategy development and testing, although it is well known that they represent a significant obstacle for realising control at full-scale facilities. The framework for incorporating faults and failures is based on Markov chains and displays the appealing property of easy transition of sensor and actuator history into a model for fault generation. The paper briefly describes Markov theory and how this is used together with models for sensor and actuator dynamics to achieve a realistic simulation of measurements and actuators.

scholarly journals Special Issue on Advanced Methods for Seismic Performance Evaluation of Building Structures

2020 ◽  
Vol 10 (20) ◽  
pp. 7353
Author(s):  
Sang Whan Han
Keyword(s):  
Performance Evaluation ◽  
Seismic Performance ◽  
Building Structures ◽  
Special Issue ◽  
Large Area ◽  
Seismic Performance Evaluation ◽  
Seismic Engineering ◽  
Seismic Regions ◽  
Moderate Seismic Regions ◽  
Great Damage

When an earthquake occurs, it causes great damage to a large area. Although seismic engineering continues to develop, it is reported that recently occurred earthquakes inflicted major damage to various structures and loss of human lives. Such earthquake damage occurs in high seismic regions as well as low to moderate seismic regions. This special issue contains topics on newly developed technologies and methods for seismic performance evaluation and seismic design of building structures.

Finite Element Analysis of a Simply Supported MR Fluid Sandwich Beam Based on ANSYS

2011 ◽  
Vol 94-96 ◽  
pp. 902-908 ◽  
Author(s):  
Zheng Xin Zhang ◽  
Fang Lin Huang ◽  
Yan Bin Wu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Modulus ◽  
Sandwich Beam ◽  
Main Idea ◽  
Magnetorheological Fluid ◽  
Element Analysis ◽  
Simply Supported ◽  
Mr Dampers ◽  
Element Type

This paper presents a method to simulate the mechanical behavior of magnetorheological fluid (MRF) subjected to magnetic field in the pre-yield region in ANSYS. The main idea is to devide an MRF element into two coincident elements, one of them has density and viscosity without shear modulus while another has shear modulus without density and viscosity. Taking a simply supported MRF sandwich beam as an example, good results and reasonable conclusion are obtained by comparing the results with the theoretical analysis and experimental study of Ref.[1]. The validity of finite element analysis is also investigated in this paper. At present, there is no exactly appropriate element type in ANSYS to model MRF, this kind of method called coincident elements method (CEM) will provide a new way to model the structures with MRF or MR dampers in ANSYS, and it also has reference roles for the future development of related elements in ANSYS.

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