Vibration Control of Plan-Asymmetric Buildings Using Active TLCGD

2010 ◽  
Vol 163-167 ◽  
pp. 3461-3464
Author(s):  
Chuan Fu
Keyword(s):  
Linear Quadratic Regulator ◽  
Liquid Column ◽  
Asymmetric Structure ◽  
Control Force ◽  
Linear Quadratic ◽  
Earthquake Excitation ◽  
Asymmetric Structures ◽  
Asymmetric Buildings ◽  
Excellent Control ◽  
Gas Damper

This paper examines the effectiveness of the Active Tuned Liquid Column Gas Damper (ATLCGD) when equipped on the plan-asymmetric structures subjected to earthquake excitation. The active behaviour is obtained by adjusting the pressure at the end of the liquid column using a pressurised reservoir. The classical linear quadratic regulator (LQR) control strategy is applied to determine optimal control force of the ATLCGDs. A case study of a four-storey asymmetric structure is conducted to illustate excellent control efficacy of the proposed active TLCGD control system.

LQR for State-Bounded Structural Control

1996 ◽  
Vol 118 (1) ◽  
pp. 113-119 ◽  
Author(s):  
C.-H. Chuang ◽  
D.-N. Wu ◽  
Q. Wang
Keyword(s):  
Structural Control ◽  
Vibration Amplitude ◽  
Gain Control ◽  
Linear Quadratic Regulator ◽  
Matching Condition ◽  
High Gain ◽  
Time Instant ◽  
Linear Quadratic ◽  
Earthquake Excitation ◽  
High Gain Control

In order to prevent structural damages, it is more important to bound the vibration amplitude than to reduce the vibration energy. However, in the performance index for linear quadratic regulator (LQR), the instantaneous amplitude of vibration is not minimized. An ordinary LQR may have an unacceptable amplitude at some time instant but still have a good performance. In this paper, we have developed an LQR with adjustable gains to guarantee bounds on the vibration amplitude. For scalar systems, the weighting for control is switched between two values which give a low-gain control when the amplitude is inside the bound and a high-gain control when the amplitude is going to violate the given bound. For multivariable systems, by assuming a matching condition, a similar controller structure has been obtained. This controller is favored for application since the main structure of a common LQR is not changed; the additional high-gain control is required only if the vibration amplitude fails to stay inside the bound. We have applied this controller to a five-story building with active tendon controllers. The results show that the largest oscillation at the first story stays within a given bound when the building is subject to earthquake excitation.

scholarly journals The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Mingying Huo ◽  
He Liao ◽  
Yanfang Liu ◽  
Naiming Qi
Keyword(s):  
Linear Quadratic Regulator ◽  
Coupled System ◽  
Control Force ◽  
Attitude Dynamics ◽  
Voltage Distribution ◽  
Linear Quadratic ◽  
Displaced Orbit ◽  
Dynamics And Control ◽  
And Control ◽  
Small Torque

Displaced solar orbits for spacecraft propelled by electric sails are investigated. Since the propulsive thrust is induced by the sail attitude, the orbital and attitude dynamics of electric-sail-based spacecraft are coupled and required to be investigated together. However, the coupled dynamics and control of electric sails have not been discussed in most published literatures. In this paper, the equilibrium point of the coupled dynamical system in displaced orbit is obtained, and its stability is analyzed through a linearization. The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit system. Numerical simulations show that the proposed strategy can control the coupled system and a small torque can stabilize both the attitude and orbit. In order to generate the control force and torque, the voltage distribution problem is studied in an optimal framework. The numerical results show that the control force and torque of electric sail can be realized by adjusting the voltage distribution of charged tethers.

Passive, Semi-Active, and Active Tuned-Liquid-Column Dampers

2006 ◽  
Author(s):  
Yung-Hsiang Chen ◽  
Ying-Jan Ding
Keyword(s):  
Proper Time ◽  
Vibration Reduction ◽  
Time Instant ◽  
Liquid Column ◽  
Control Force ◽  
Earthquake Excitation ◽  
Water Head ◽  
Mass Damper ◽  
Liquid Column Dampers ◽  
Shear Building

The dynamic characteristics of the passive, semi-active, and active tuned-liquid-column dampers (or TLCD’s) are studied in this paper. The design of the latter two are based on the first one. The water-head difference of a passive TLCD is pre-set to form the so-called semi-active one in this paper. The water-head difference is released at a proper time instant during an earthquake excitation to enhance the vibration reduction of a structure. Two propellers are installed along a shaft inside and at the center of a passive TLCD to form an active one. These two propellers are driven by a servomotor controlled by a computer to provide the control force. The seismic responses of a five-story shear building with a passive, semi-active, or active TLCD are computed for demonstration and discussion. The results of this building with a tuned mass damper (or TMD) are also included for comparison.

Adaptive control of damaged structures by using smart tunable liquid column gas damper considering dynamic soil–structure interaction

2021 ◽  
pp. 136943322110369
Author(s):  
Fereidoun Amini ◽  
Nazanin Nazmdar Shahri
Keyword(s):  
Soil Structure ◽  
Liquid Column ◽  
Soil Structure Interaction ◽  
Earthquake Excitation ◽  
Structure Interaction ◽  
Passive Dampers ◽  
Liquid Column Dampers ◽  
Control Forces ◽  
Gas Damper ◽  
External Forces

Liquid column dampers are adjusted based on the characteristics of the host structure and the type of external forces. It is assumed in most studies that the structure is rigidly connected to the ground, and the characteristics of the structure are invariant during external excitations. The performance of passive dampers may lose, or structural displacements may be increased by changing these conditions. This study presented a new method to find the optimal control forces for structures equipped with smart tuned liquid column gas damper (TLCGDs), considering variable characteristics of the structure and the soil–structure interaction. The proposed method calculates the gas pressure inside the columns by regularly adjusting and updating the frequency and damping of the TLCGD. The unknown or changed soil–structure characteristics are estimated by a system identification method, and damper parameters are determined through an optimization algorithm. The method was tested on 3- 9- and 10-story shear buildings under harmonic and earthquake excitation. According to the results, the smart damper more effectively reduced the structural displacement.

Optimum Structural Vibration Control With Bounds on Control Forces

1995 ◽  
Author(s):  
Alexander A. Bolonkin ◽  
Duane E. Veley ◽  
Narendra S. Khot
Keyword(s):  
Control System ◽  
Linear Quadratic Regulator ◽  
Structural Vibration ◽  
Control Force ◽  
Linear Quadratic ◽  
Structural Vibration Control ◽  
Structure Control ◽  
Design Variables ◽  
Control Devices ◽  
Control Forces

Abstract This paper describes an approach for designing a structure-control system based on the linear quadratic regulator (LQR) which suppresses vibrations in structures. Bounds are placed on the control forces to simulate real actuators. The control system is optimized with an objective function of the total weight of the control devices. The design variables are the bounds (which are proportional to the weight of the control devices) on each control force with a constraint on the time to reduce the energy of the vibration to 5% of its initial value. As an example to illustrate the application of an approach, a wing box idealized by rod elements is used. Control systems are designed for this structure using four and eight actuators for several locations.

Seismic Control Research of Longitudinal Floating Bridge Based on MR Damper

2011 ◽  
Vol 117-119 ◽  
pp. 201-205
Author(s):  
Meng Gang Yang ◽  
Kui Ouyang
Keyword(s):  
Time Delay ◽  
Vibration Control ◽  
Seismic Response ◽  
Mr Damper ◽  
Control Force ◽  
Longitudinal Displacement ◽  
Linear Quadratic ◽  
Earthquake Excitation ◽  
Seismic Control ◽  
Floating Bridge

In order to reduce the longitudinal displacement of longitudinal floating bridge subject to earthquake excitation, seismic response reduction control strategy for longitudinal floating bridge with MR damper is developed based on the MATLAB software for numerical simulation and the vibration control algorithm of classical linear quadratic of full-state feedback. In this paper, the seismic response reduction analysis for a longitudinal floating bridge, Pingsheng Bridge which is a self-anchored suspension bridge with a single tower, is completed, and also the optimal active control force is obtained. Furthermore, the effect of time delay on seismic control is investigated. The results show that the longitudinal displacement of longitudinal floating bridge can be effectively reduced by vibration control system with MR damper, and the time delay has little influence on seismic response reduction of longitudinal floating bridge.

scholarly journals Semi-Active Control of Vehicle Seat Suspension System with Magnetorheological Damper

2011 ◽  
Vol 2-3 ◽  
pp. 1067-1070
Author(s):  
Hai Jun Xing ◽  
Shao Pu Yang ◽  
Yong Jun Shen
Keyword(s):  
Active Control ◽  
Ride Comfort ◽  
Linear Quadratic Regulator ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Vehicle Body ◽  
Control Force ◽  
Linear Quadratic ◽  
Seat Suspension ◽  
Vehicle Seat

This research aims at the vibration control of vehicle seat suspension system. A three degree of freedom quarter vehicle model is used for semi-active control system in which a magnetorheological damper (MRD) is installed at the position between the vehicle body and the seat. A fully active linear quadratic regulator (LQR) control strategy is used to determine the optimized control force which is then matched by MRD to compute the semi-active control result. Computation result proves that semi-active control with MRD can alleviate the vehicle seat acceleration to improve ride comfort.

Optimal Control of Sandwich Panels with Pyramidal Truss Cores Based on Energy Criterion

2008 ◽  
Vol 33-37 ◽  
pp. 1419-1424
Author(s):  
Hua Rui Liu ◽  
J.L. Yang
Keyword(s):  
Optimal Control ◽  
Sandwich Panel ◽  
Linear Quadratic Regulator ◽  
Energy Criterion ◽  
Weight Coefficient ◽  
Coefficient Matrix ◽  
Control Force ◽  
Linear Quadratic ◽  
Pyramidal Truss ◽  
And Control

This paper is addressed to the optimal control of the simply supported sandwich panel with pyramidal truss cores. Firstly, according to the sandwich theory proposed by Sorokin and Ershova, the eigenfrequencies of the sandwich panel are studied. Then based on the energy criterion, the weight coefficient matrix Q and R for the linear quadratic regulator method are obtained. By solving the Riccati equation, the displacement and control force are given. The curves for the displacement response at the center of the plate are shown. From the numerical results, it is found that this method is effective in suppressing the vibration of the sandwich panel with pyramidal truss cores.

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