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.

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.

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.

Semi-Active Control for Large-Scale Aqueduct by MR Damper

2011 ◽  
Vol 204-210 ◽  
pp. 645-648
Author(s):  
Liang Huang ◽  
Bo Wang ◽  
Jian Guo Xu
Keyword(s):  
Active Control ◽  
Seismic Design ◽  
Mechanical Model ◽  
Large Scale ◽  
Mr Damper ◽  
Earthquake Excitation ◽  
Active Method ◽  
Reference Base ◽  
Active Devices ◽  
Magneto Rheological

The mechanical model of magneto rheological damper(MRD) is established, and the numerical simulation of seismic responses of aqueduct under earthquake excitation is performed with magneto rheological dampers. The results indicated that the magneto rheological dampers are effective in reducing the aqueduct response, the mitigation rate of semi-active control approaches with the active method The results from the present study may serve as a reference base for seismic design of large-scale aqueducts, and provide theoretical basis of aqueduct using semi-active devices.

Real-Time Hybrid Testing of a Steel-Structure Equipped With Large-Scale Magneto-Rheological Dampers Applying Semi-Active Control Algorithms

2008 ◽  
Author(s):  
Eunchurn Park ◽  
Sung-Kyung Lee ◽  
Heon-Jae Lee ◽  
Seok-Joon Moon ◽  
Hyung-Jo Jung ◽  
...  
Keyword(s):  
Real Time ◽  
Active Control ◽  
Large Scale ◽  
Mr Damper ◽  
Control Algorithms ◽  
Strong Nonlinearity ◽  
Control Force ◽  
Hybrid Testing ◽  
Mr Dampers ◽  
Comparison Results

This study introduces the quantitative evaluation of the seismic performance of a building structure equipped with MR dampers by using real-time hybrid testing method (RT-HYTEM). A real-scaled 5-story building is used as the numerical substructure, and MR dampers corresponding to an experimental substructure is physically tested by using UTM. First, the force required to drive the displacement of the story, at which the MR damper is located, is measured from the load cell attached to UTM. Then, the measured force is returned to a control computer to calculate the response of the numerical substructure. Finally, the experimental substructure is excited by UTM with the calculated response of the numerical substructure. The RT-HYTEM implemented in this study is validated for that the real-time hybrid testing results obtained by application of sinusoidal and earthquake excitations and the corresponding analytical results obtained by using the Bouc-Wen model as the control force of the MR damper respect to input currents were in good agreement. Furthermore, semi-active control algorithms were applied to the MR damper. The comparison results of experimental and numerical responses demonstrated that using RT-HYTEM was more reasonable in semi-active devices such as MR dampers having strong nonlinearity.

Semi Active Control of Chaos in Systems Excited by Non-Ideal DC Motor

2011 ◽  
Vol 110-116 ◽  
pp. 5367-5372
Author(s):  
Saeed Farokhi ◽  
Aghil Yosefi Komma ◽  
Zohreh Bayat
Keyword(s):  
Active Control ◽  
Control Method ◽  
Mr Damper ◽  
Dc Motor ◽  
Viscous Damper ◽  
Control Of Chaos ◽  
Linear Spring ◽  
Chaotic Characteristic ◽  
Magneto Rheological ◽  
Active Control Method

In this paper, semi active control of non-ideal mechanical system with Magneto-Rheological (MR) damper is presented. The setup composed of a motor operating on a structure with mass M connected to a fixed frame by a non-linear spring and with a linear viscous damper. From the investigations carried out it is possible to observe the DC motor influence on the vibrating system along with non-periodic motions with chaotic characteristic. To control this system linear viscose damper is substituted by MR damper. A semi-active control method, sky-hook control is used in this study. Our results suggest that the addition of a MR damper turns the phase space smoother and it is so effective to suppress chaos.

Application of Semi-Active Inerter in Semi-Active Suspensions Via Force Tracking

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Michael Z. Q. Chen ◽  
Yinlong Hu ◽  
Chanying Li ◽  
Guanrong Chen
Keyword(s):  
Active Control ◽  
Ride Comfort ◽  
Controller Design ◽  
Active Suspension ◽  
Damping Coefficient ◽  
Control Law ◽  
Control Force ◽  
Car Model ◽  
Force Tracking ◽  
Active Damper

This paper investigates the application of semi-active inerter in semi-active suspension. A semi-active inerter is defined as an inerter whose inertance can be adjusted within a finite bandwidth by online control actions. A force-tracking approach to designing semi-active suspension with a semi-active inerter and a semi-active damper is proposed in this paper. Two parts are required in the force-tracking strategy: a target active control law and a proper algorithm to adjust the inertance and the damping coefficient online to track the target active control law. The target active control law is derived based on the state-derivative feedback control methodology in the “reciprocal state-space” (RSS) framework, which has the advantage that it is straightforward to use the acceleration information in the controller design. The algorithm to adjust the inertance and the damping coefficient is to saturate the active control force between the maximal and the minimal achievable suspension forces of the semi-active suspension. Both a quarter-car model and a full-car model are considered in this paper. Simulation results demonstrate that the semi-active suspension with a semi-active inerter and a semi-active damper can track the target active control force much better than the conventional semi-active suspension (which only contains a semi-active damper) does. As a consequence, the overall performance in ride comfort, suspension deflection, and road holding is improved, which effectively demonstrates the necessity and the benefit of introducing semi-active inerter in vehicle suspension.

Semi-Active Control for Vibration of Transmission Tower-Line with MRD

2014 ◽  
Vol 680 ◽  
pp. 422-425
Author(s):  
Wei Kong ◽  
Yun Fei Tao ◽  
Shi Guang Men
Keyword(s):  
Active Control ◽  
Control Algorithm ◽  
Mr Damper ◽  
Control Device ◽  
Transmission Tower ◽  
Passive Devices ◽  
Control Devices ◽  
Self Powered ◽  
Technological Means ◽  
Magneto Rheological

Magneto-rheological (MR) damper is a semi-active control device, which takes advantage of both the reliability of passive devices and the adaptability of fully active control devices and is widely used on many kinds of machines and civil works. But there are some particular problems when the MRD is used on transmission tower-line system.This article is aimed to introduce the technological means to these problems such as :choose sant colony algorithm as the suitable semi-active control algorithm; consider adopting Self-Powered/Self-Sensing structure to Increased general OS stability;

Investigation of Locking Force of Stay Cable Vibration Control Using Magneto-Rheological Fluid Damper

Aerospace ◽  
2006 ◽  
Author(s):  
Liu Min ◽  
Vineet Sethi ◽  
Gangbing Song ◽  
Hui Li
Keyword(s):  
Vibration Control ◽  
Smart Materials ◽  
Mr Damper ◽  
Pole Placement ◽  
Stay Cable ◽  
Cable Vibration ◽  
Bridge Model ◽  
Mode Vibration ◽  
Magneto Rheological ◽  
Multi Mode

This paper analyzes the locking force of a stay cable equipped with a Magneto-rheological (MR) damper. For the single mode vibration of the stay cable, the formula of the locking force is derived and the important factors that affect the locking force are analyzed. The experimental investigations of the locking force of the stay cable vibration control are carried out on a cable-stayed bridge model equipped with an MR damper to verify of the computational locking force in the Smart Materials and Structures Laboratory at University of Houston. For the multi-mode vibration of the stay cable, the modal shapes of the stay cable vibration are estimated by utilizing a pole placement observer using the acceleration values at selected locations of the stay cable and the locking forces of the stay cable in multi-mode vibration are numerically obtained. In all experimental cases, the locking forces based on the analytical and numerical formulas approximately match the experimental results.

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