Article

Real‐time control performance of a model‐reference adaptive structural control system under earthquake excitation

Structural Control and Health Monitoring (Impact Factor: 1.54). 02/2010; 17(2):198 - 217. DOI: 10.1002/stc.287

ABSTRACT Recent publications have presented successful implementations of adaptive control techniques in various applications whereas its application on vibration suppression of civil infrastructures under adverse conditions is not well developed. The advantage of a model-reference adaptive structural control (MRASC) algorithm is to adjust the control command signal and to force the controlled system follow the trajectory of designed reference model while estimating properties of the controlled structure in real time. An adaptive control application based on Lyapunov stability theory is presented in this paper. The Lyapunov equation used to define the adaptation law is designed based on a quadratic Lyapunov function candidate. This energy-like scalar function comprises weighted tracking-error states and parameter-estimating error matrix. The adaptive feedback control force is calculated from both measured states and adjustable parameters estimated from the adaptation law. The tracking-error states illustrate the trajectory tracking performance between reference model and controlled system. The global asymptotical stability is guaranteed by choosing a pair of positive-definite weighting matrices for the time-invariant linear system. Systematic procedures based on fast convergence rate of the adjustable parameters are proposed to determine appropriate combination of coefficients embedded in the weighing matrices of Lyapunov function. A series of control performance investigation is performed on a single degree-of-freedom active tendon structure subjected to different earthquake excitations. Copyright © 2008 John Wiley & Sons, Ltd.

0 Bookmarks
 · 
78 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper addresses the controller design problem of a nonlinear single degree-of-freedom structural system excited by the earthquake. Bouc–Wen model, as an efficient hysteresis modeling method, is used to model the system nonlinearity. Sliding mode control (SMC), due to its robustness in dealing with uncertainty, is utilized as the main control strategy. An optimal sliding surface is presented which minimizes the displacement and control force in terms of a quadratic cost function. Two numerical examples are given to illustrate the effectiveness of the proposed strategy subject to three earthquakes of El-Centro, Rinaldi and Kobe. Simulation results show a significant and considerable reduction in structural response and indicate that the performance of suggested optimal SMC strategy is remarkable.
    Communications in Nonlinear Science and Numerical Simulation 11/2012; 17(11):4455–4466. · 2.57 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Substantial progress has been made in analyzing the integrity of composite structures when macro or nano sensors and actuators are embedded into it. The resulting structure in a dynamic environment is said to be "intelligent" if it performs a certain functional requirements related to vibrations, health, shape, etc. In health, after the damage has been detected, the subject of damage mitigation becomes important, so that in prognosis context (Farrar and Lieven, 2007), the remaining life of the structure is extended. The damage is said to be mitigated if the sensor data of the damaged structure matches with the sensor data of the healthy structure. This is done by applying an actuator loading. In this paper, Model Reference Adaptive Control (Slotine and Li, 1991) is applied for structural damage mitigation. A known finite element model resulting from the structural health monitoring and assessment techniques is adopted to determine the control parameters that mitigate the damage. An example is illustrated using a spring-mass-damper model that depicts a structural model with modal coordinates. Abstract Substantial progress has been made in analyzing the integrity of composite structures when macro or nano sensors and actuators are embedded into it. The resulting structure in a dynamic environment is said to be "intelligent" if it performs a certain functional requirements related to vibrations, health, shape, etc. In health, after the damage has been detected, the subject of damage mitigation becomes important, so that in prognosis context (Farrar and Lieven, 2007), the remaining life of the structure is extended. The damage is said to be mitigated if the sensor data of the damaged structure matches with the sensor data of the healthy structure. This is done by applying an actuator loading. In this paper, Model Reference Adaptive Control (Slotine and Li, 1991) is applied for structural damage mitigation. A known finite element model resulting from the structural health monitoring and assessment techniques is adopted to determine the control parameters that mitigate the damage. An example is illustrated using a spring-mass-damper model that depicts a structural model with modal coordinates.
    01/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper addresses the problem of structural control for mitigating seismic effects in the presence of structural parameter uncertainties. A linear single degree-of-freedom (DOF) structure is considered. It is supposed that mass, damping and stiffness coefficients of the structure contain uncertainty. Two different methods based on sliding mode control (SMC) are proposed. The first method uses upper bounds of the system uncertainties in the control law but in the second method a prior knowledge about the bounds of the uncertainties is not necessary and the controller adapts itself during the control procedure. Numerical simulation is used to show the efficiency of the proposed approaches. The simulation results depict that both methods cause significant reduction in the displacement and velocity of the controlled structure in comparison with the uncontrolled one. Furthermore, the magnitude of control forces reveal that implementation of the proposed methods from the viewpoint of real-world applications is feasible.
    01/2012;