Seismic Protection of Structures Using Tuned Mass Dampers with Resettable Variable Stiffness

2012 ◽  
Vol 83 ◽  
pp. 75-84
Author(s):  
Chi Chang Lin ◽  
Tsu Teh Soong
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
Good Control ◽  
Variable Stiffness ◽  
Seismic Protection ◽  
Control Law ◽  
Control Performance ◽  
Deformation Diagram ◽  
Tuned Mass Dampers ◽  
Engineering Structures

Vibration control of civil engineering structures using tuned mass dampers (TMD) is a widely accepted control strategy after numerous analytical and experimental verifications. Although the design and application of traditional linear TMD systems are well developed, nonlinear TMD systems that may lead to better control performance are still in the developmental stage. There are two main problems associated with TMD systems, i.e. (1) detuning effect and (2) excessive stroke of TMD. In order to improve the performance of TMD systems, a novel semi-active TMD named resettable variable stiffness TMD (RVS-TMD) is proposed in this study. The RVS-TMD consists of a TMD and a resettable variable stiffness device (RVSD). The RVSD is composed of a resettable element and a controllable stiffness element. By varying the stiffness element of the RVSD, the force produced by the RVSD can be controlled smoothly through a semi-active control law. By resetting the resettable element, the hysteresis loop of the RVSD can cover all four quadrants in the force-deformation diagram and thus results in more energy dissipation. The harmonic and seismic responses of a building equipped with the RVS-TMD are investigated numerically and compared with those by its active control counterpart and an optimal passive TMD system. The results show that the proposed RVS-TMD system has good control performances as its active control counterpart and is able to alleviate detuning effect and reduce TMD’s stroke.

Scheduling Strategy of Multiple Semi-Active Controllers With Information on the Disturbance and the Structural Response

2016 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda
Keyword(s):  
Optimal Control ◽  
Control System ◽  
Active Control ◽  
Structural Response ◽  
Design Parameters ◽  
Control Law ◽  
Control Performance ◽  
Multiple Control ◽  
Control Laws ◽  
Scheduling Strategy

A scheduling strategy of multiple semi-active control laws for various earthquake disturbances is proposed to maximize the control performance. Generally, the semi-active controller for a given structural system is designed as a single control law and the single control law is used for all the forthcoming earthquake disturbances. It means that the general semi-active control should be designed to achieve a certain degree of the control performance for all the assumed disturbances with various time and/or frequency characteristics. Such requirement on the performance robustness becomes a constraint to obtain the optimal control performance. We propose a scheduling strategy of multiple semi-active control laws. Each semi-active control law is designed to achieve the optimal performance for a single earthquake disturbance. Such optimal control laws are scheduled with the available data in the control system. As the scheduling mechanism of the multiple control laws, a command signal generator (CSG) is defined in the control system. An artificial neural network (ANN) is adopted as the CSG. The ANN-based CSG works as an interpolator of the multiple control laws. Design parameters in the CSG are optimized with the genetic algorithm (GA). Simulation study shows the effectiveness of the approach.

Semi-Active Control of Structural Systems Aiming to Approximate the Performance of the Targeted Active Control Law: Output Emulation Approach

2013 ◽  
Author(s):  
Kazuhiko Hiramoto ◽  
Taichi Matsuoka ◽  
Katsuaki Sunakoda
Keyword(s):  
Control System ◽  
Active Control ◽  
Variable Parameter ◽  
Control Law ◽  
Structural Systems ◽  
Control Force ◽  
Control Performance ◽  
Control Devices ◽  
Active Control System ◽  
Control Output

As a method for semi-active control of structural systems, the active-control-based method that emulates the control force of a targeted active control law by semi-active control devices has been studied. In the active-control-based method, the semi-active control devices are not necessarily able to generate the targeted active control force because of the dissipative nature of those devices. In such a situation, the meaning of the targeted active control law becomes unclear in the sense of the control performance achieved by the resulting semi-active control system. In this study, a new semi-active control strategy that approximates the control output (not the control force) of the targeted active control is proposed. The variable parameter of the semi-active control device is selected at every time instant so that the predicted control output of the semi-active control system becomes close to the corresponding predicted control output of the targeted active control as much as possible. Parameters of the targeted active control law are optimized in the premise of the above “output emulation” strategy so that the control performance of the semi-active control becomes good and the “error” of the achieved control performance between the targeted active control and the semi-active control becomes small.

Simulation Analysis of Control Strategy for TLT Wheel Coordination Based on Constant Pressure Network

2012 ◽  
Vol 591-593 ◽  
pp. 1962-1967
Author(s):  
Li Jun Zhao ◽  
Na Li ◽  
Tao Fang
Keyword(s):  
Control Strategy ◽  
Constant Pressure ◽  
Simulation Analysis ◽  
Good Control ◽  
High Power Density ◽  
Control Performance ◽  
Hydrostatic Transmission ◽  
Control Precision ◽  
Driving Condition ◽  
Further Development

Hydrostatic transmission with secondary regulation based on constant pressure network (CPN) has the advantages of stepless speedless regulation, high power density, etc. This paper applies it to a Towbarless Tractor (TLT) transmission system and aims to improve its wheel control precision. A control strategy for TLT wheel coordination under driving condition is proposed and simulation is carried out in our facing-backward simulation model. The results show that good control performance can be realized by the control strategy. It can effectively achieve the goal of antislip. Moreover, the simulation analysis provides significant reference values for further development of wheel coordination controllers.

Fuzzy Control Strategy Based on Mode Identification Used in Semi-Active Control

2011 ◽  
Vol 71-78 ◽  
pp. 3975-3982 ◽  
Author(s):  
Qing Li Meng ◽  
Min Zheng Zhang ◽  
Jian Ye
Keyword(s):  
Numerical Simulation ◽  
Fuzzy Control ◽  
Active Control ◽  
Drift Velocity ◽  
Control Strategy ◽  
Passive Control ◽  
Control Law ◽  
Mode Identification ◽  
Control Arithmetic ◽  
Fuzzy Control Strategy

In this paper, a new fuzzy control arithmetic based on mode identification used in semi-active control is put forward, the mode is differentiated by the eigenvectors constituted with drift, velocity and their resultant, and then different fuzzy control strategy is applied. Moreover, by numerical simulation, the control efficiency of the new control arithmetic is compared with semi-active control using sign control law and some passive control.

Vibration control performance of tuned mass dampers with resettable variable stiffness

2015 ◽  
Vol 83 ◽  
pp. 187-197 ◽  
Author(s):  
Ging-Long Lin ◽  
Chi-Chang Lin ◽  
Bo-Cheng Chen ◽  
Tsu-Teh Soong
Keyword(s):  
Vibration Control ◽  
Variable Stiffness ◽  
Control Performance ◽  
Tuned Mass Dampers

Stochastic optimal semi-active control of stay cables by using magneto-rheological damper

2010 ◽  
Vol 17 (13) ◽  
pp. 1921-1929 ◽  
Author(s):  
M Zhao ◽  
WQ Zhu
Keyword(s):  
Active Control ◽  
Control Strategy ◽  
Mr Damper ◽  
Stochastic Averaging ◽  
Control Law ◽  
Control Force ◽  
Stay Cable ◽  
Dynamical Programming ◽  
Magneto Rheological ◽  
Bang Bang Control

Stochastic optimal semi-active control for stay cable multi-mode vibration attenuation by using magneto-rheological (MR) damper is developed. The Bingham model for an MR damper is used. The force produced by an MR damper is split into passive and active parts. The passive part is combined with structural damping forces into effective damping forces. The partially averaged Itô stochastic differential equations for controlled modal energies are derived by applying the stochastic averaging method for quasi-integrable Hamiltonian systems. Then the dynamical programming equation for controlled modal energies with an index involving control force is established by applying the stochastic dynamical programming principle, and a stochastic optimal semi-active control law is obtained by solving the dynamical programming equation. For controlled modal energies with an index not involving control force, bang-bang control law is obtained without solving a dynamical programming equation. A comparison between the two control laws shows that the stochastic optimal semi-active control strategy is superior to the bang-bang control strategy in the sense of higher control effectiveness and efficiency and less chattering.

scholarly journals A Hybrid Nonlinear Active Control Strategy Combining Dry Friction Control and Nonlinear Velocity Compensation Control

2021 ◽  
Vol 11 (24) ◽  
pp. 11670
Author(s):  
Donglai Yang ◽  
Xingrong Huang ◽  
Xiaodong Yang
Keyword(s):  
Active Control ◽  
Friction Force ◽  
Control Strategy ◽  
Dry Friction ◽  
Vibration Suppression ◽  
Hybrid Control ◽  
Control Law ◽  
Control Force ◽  
Friction Dampers ◽  
Nonlinear Velocity

Friction dampers are widely used in structural vibration suppression in various fields, such as aeronautics, astronautics, robotics, precision manufacturing, etc. Traditional friction dampers are mainly used in a passive way to optimize vibration suppression with an immutable pressure around certain excitation. In this manuscript, a hybrid control strategy by considering both the friction force in the active control law and a nonlinear velocity compensation force is put forward: First, the normal force applied on the friction damper was adjusted to ensure its vibration reduction effect under different excitation for a first passive control; second, the active control law was established by combining the dry friction force and the velocity control force in the state space; lastly, the stability of the nonlinear control law was determined by Lyapunov criterion. Numerical simulations were conducted on a three degree-of-freedom system (3-DOF) based on the proposed hybrid control strategy, to show the control efficiency in vibration suppression and economic efficiency in energy input into the system. Simulation results showed that the proposed control law could reduce the amplitude of the active control force by about 5% without degrading the control efficiency.

Controlling chemical dosing for sulfide mitigation in sewer networks using a hybrid automata control strategy

2013 ◽  
Vol 68 (12) ◽  
pp. 2584-2590 ◽  
Author(s):  
Yiqi Liu ◽  
Ramon Ganigué ◽  
Keshab Sharma ◽  
Zhiguo Yuan
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Biological Processes ◽  
Control Performance ◽  
Hybrid Automata ◽  
Sewer Pipe ◽  
Physical Chemical ◽  
Iron Salts ◽  
Pumping Stations ◽  
Sewer Networks

Chemicals such as magnesium hydroxide (Mg(OH)2) and iron salts are widely used to control sulfide-induced corrosion in sewer networks composed of interconnected sewer pipe lines and pumping stations. Chemical dosing control is usually non-automatic and based on experience, thus often resulting in sewage reaching the discharge point receiving inadequate or even no chemical dosing. Moreover, intermittent operation of pumping stations makes traditional control theory inadequate. A hybrid automata-based (HA-based) control method is proposed in this paper to coordinate sewage pumping station operations by considering their states, thereby ensuring suitable chemical concentrations in the network discharge. The performance of the proposed control method was validated through a simulation study of a real sewer network using real sewage flow data. The physical, chemical and biological processes were simulated using the well-established SeweX model. The results suggested that the HA-based control strategy significantly improved chemical dosing control performance and sulfide mitigation in sewer networks, compared to the current common practice.

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