Active Tuned Mass Damper System Research Articles

Online Adaptive Neurochaotic Fuzzy Controller Design to Reduce the Seismic Response of Buildings Equipped with Active Tuned Mass Damper System

This paper presents a novel adaptive neurochaotic fuzzy control system based on type-2 fuzzy systems to reduce seismic responses in multistory structures with active tuned mass dampers under near-field and far-field earthquakes. In this proposed control system, the whole parameters of the plant are assumed to be completely unknown, the structural model is estimated using a multilayer perceptron neural network, and the system’s Jacobian is extracted. The online estimation model is used, and the controller parameters are adaptively trained using the extended Kalman filter and error back-propagation method. Subsequently, the control force is applied to the active tuned mass damper, and the control objectives are met. The adaptive controller does not require initial settings, and a fractional-order proportional-integral-derivative controller is added to maximize stability and robustness against seismic vibration. A simple adaptive controller optimized by a particle swarm is also presented as an innovation. Comparing the performance of the improved simple adaptive controller and adaptive neurochaotic fuzzy controller, the proposed controllers appear more efficient and accurate. However, the superiority of the novel adaptive neurochaotic fuzzy over the improved simple adaptive controller in reducing maximum displacement, acceleration, drift, and base shear while maintaining acceptable performance under parametric uncertainties and seismic conditions is substantial.

Adaptive backstepping control design for ATMD systems in nonlinear structures with nonlinear disturbance and parametric uncertainties

Active tuned mass damper (ATMD) devices are recommended in various structures to reduce vibrations. The performance of the ATMD system is closely tied to the control design utilized, according to research in the literature. The designed control input will take into account as much system dynamics as possible, making it possible to use it as a generalized controller in all similar systems. Nonlinear behavior is the natural behavior of engineering structures, and in order to obtain a more realistic and high-performance ATMD system, it can be considered as an appropriate approach to design the controller by considering the structural nonlinearities. In addition, unexpected external influences and parameter uncertainties must be taken into account during control design to ensure that control systems perform successfully in similar systems in all conditions. Therefore, in this study, the nonlinear model of the multi-story building was reconstructed by adding nonlinear disturbance to represent unknown external effects. Band-limited white noise is used as a disturbance function and Gaussian white noise is added to measured states in this study. To obtain a robust controller, unknown structural parameters are compensated for by using adaptive compensation terms. With the controller design supported by the Lyapunov-based stability analysis, the stability of the vibrating structure featuring an ATMD is theoretically guaranteed while achieving the main control goal. Performance analyses of the designed controllers are carried out with simulation studies. The efficiency of the developed Lyapunov-based controller in dampening the unwanted vibrations that occurred on the building is seen in simulation results.

Sliding sector–based adaptive controller for seismic control of structures equipped with active tuned mass damper

Active tuned mass damper (ATMD) as a reliable active device of structural control can protect structures subjected to earthquake excitations from the severe seismic damages. The present study focus on the design of an adaptive sliding sector controller (ASSC) employed in the ATMD system to mitigate the seismic responses of an 11–story shear building under earthquake excitations. The ASSC technique is designed based on the hyper-surface of the sliding mode which is surrounded by a sector and can consider the uncertainty of system parameters. In this study, the design of the ASSC strategy is first implemented for the structure subjected to an artificial earthquake excitation. Then, the performance of the ASSC strategy is evaluated in mitigating the seismic responses of the structure under four near– and far–fault earthquake excitations. Furthermore, the efficiency of the ASSC strategy is also compared against that of a few control techniques including proportional-integral-derivative [PID], linear-quadratic regulator [LQR], fuzzy logic control [FLC], optimal sliding mode control [OMSC]. Comparative results of the numerical simulation confirm the robustness and ability of the ASSC strategy for the reduction of the structural responses under real earthquake excitations.

Investigation of modal parameters of a 600-m-tall skyscraper based on two-year-long structural health monitoring data and five typhoons measurements

On the basis of two-year-long structural health monitoring data, this paper investigates the structural dynamic properties of a 600-m-high supertall building installed with an active tuned mass damper (ATMD) system. The long-term modal parameters such as natural frequencies and damping ratios of the monitored skyscraper are first determined by the stochastic subspace identification approach, and the results generally agree well with those obtained by the finite element method and forced vibration tests. The statistical analysis of the modal parameters indicates that the natural frequencies follow the normal distribution, while the damping ratios fit well with the Gumbel distribution. In addition, the two-year-long variations of the modal parameters with ambient environmental factors are investigated and it is found that both the ambient temperature and humidity have limited effects on the modal parameters of the skyscraper. Moreover, the impacts of the ATMD system on the modal parameters are explored based on the field measurements during five typhoons. The analyzed results demonstrate that the active damper system had significant effects on the modal parameters of the fundamental sway modes, while it had marginal influences on these of higher modes. This study aims to enhance the understanding of structural dynamic properties of supertall buildings and provide useful information for their wind-resistant design.

Dynamic performance evaluation of a 492 m super high-rise building with active tuned mass dampers during four consecutive landfall typhoons within a month

Field measurement is the most reliable and intuitive method to assess the wind effects of super high-rise buildings. However, due to the different inherent characteristics of each typhoon, the observations may be different or even contradictory. Therefore, there is a need to conduct further analysis on the wind effects during typhoons to reveal more general results. In this study, wind-induced acceleration responses collected by the structural health monitoring system installed atop the Shanghai World Financial Center (SWFC) during the landfall of four consecutive typhoons (Ampil, Jongdari, Yagi and Rumbia) within a month are systematically investigated. The first five-order modal directions are determined based on the spectral method. The envelope random decrement technique is adopted to identify the natural frequencies and damping ratios, and the amplitude dependencies and time-varying characteristics of the structural dynamic properties are also analyzed. Furthermore, the control performance of active tuned mass damper (ATMD) system during typhoons is discussed. Finally, the serviceability of the skyscraper during typhoons is assessed, and the global damage evaluation is performed. The results show that the natural frequencies decrease with increasing amplitude and present V-shaped variation trends with time. The damping ratios almost increase with increasing amplitudes but do not show any noticeable variation trend with time. The time-varying environmental conditions may have considerable effects on the modal parameters, and those effects may be superimposed in a short time. The ATMD system can effectively mitigate wind-induced vibrations. The occupant comfort is satisfactory, and no evident structural damage is detected during typhoons.

Vibration mitigation performance of active tuned mass damper in a super high-rise building during multiple tropical storms

On the basis of field measurements on a super high-rise building equipped with an active tuned mass damper (ATMD) system during seven tropical storms, this paper presents a systematic investigation of the vibration mitigation performance of the active control system under extreme wind conditions. The field-measured building acceleration responses indicate that the ATMD system can be precisely triggered to operate following its operating principle and significantly suppress the acceleration responses of fundamental sway modes of the monitored skyscraper but has marginal effects on those of higher modes. Moreover, the effects of the ATMD system on structural dynamic properties of the super high-rise building are investigated. The results show that the damping ratios of the fundamental sway modes can be remarkably boosted from about 0.6 % to 2 % ∼ 7 % by the active damper system, and the increment of damping ratios decreases as building vibration amplitude. The outputs of this paper aim to offer advantageous guidance for the design of vibration control devices and thereby provide helpful information for the wind-resistant design of super high-rise buildings.

An Adaptive Controller Design for ATMD System Used in Structures Under the Effect of Unknown Nonlinear Effects

Active tuned mass damper (ATMD) devices are favored in many applications to reduce vibrations induced by earthquakes in multi-story structures. In the literature, the Lyapunov-based controller design for ATMD systems is a popular topic of research. The building structures have been modeled linearly in the majority of studies so far in the literature. As a result, the controls in these researches are linear as well. Only a few studies have considered the nonlinear dynamics of multi-story structures, however, in these works, linear control schemes employing various linearization approaches are provided. Nonlinear behavior is the inherent behavior of multi-story buildings with ATMD systems. As a consequence, studying nonlinear dynamics while designing a nonlinear controller is regarded to be a more realistic approach. Furthermore, numerous unpredictable external factors should be considered during control design to guarantee that the control systems are able to operate securely in any environment. In order to create a more realistic approach, the linear model of the multi-story structure is reconfigured in this work by adding nonlinear ambiguous functions to it. It was assumed in this study that the structural parameters were unknown at the time of controller design. Adaptive compensation rules replace all system parameters of the system necessary in control design. Theoretically, Lyapunov-based arguments are used to show that the developed controller can keep the structure stable while attaining the main control aim. Matlab-Simulink is used to analyze the performance of the developed controllers.

A backstepping control design for ATMD systems of building structure against earthquake excitations in the presence of parametric uncertainty

The design of a novel backstepping controller for using with active tuned mass damper (ATMD) system is investigated in this study. The main aim of this study is to design the controller for the ATMD system to reduce earthquake-induced vibrations in multistory buildings. Obtaining a generalizable control design for such systems is another important aim of this study. To reach this aim, the designed controller is based on the assumption that the system parameters are completely uncertain. The parametric uncertainty is coped with via adaptive compensation rules proposed in accordance with available system states. Effects of the control force on the displacement of the controller mass and the last floor of a multistory building are considered together. Owing to this approach, a control operation is provided in which zero convergence of the displacement of the mass of ATMD and all floors of the building can be guaranteed. Using Lyapunov-based arguments, theoretically, it has been proven that the designed controller can maintain its stability of the structure and controller mass while achieving this main control objective. The efficiency of the designed controller in terms of reaching the mentioned control objective is observed via numerical simulations. In these simulations, the designed controller is used in conjunction with an ATMD system placed on a multistory building model, and it has been shown that the controller designed in such structures can be used effectively for damping the earthquake-induced vibrations of these types of structures.

Control performance of active tuned mass damper for mitigating wind-induced vibrations of a 600-m-tall skyscraper

Based on the field measurements on a 600-m-tall skyscraper equiped with an active tuned mass damper (ATMD) system, this paper investigates the control performance of the world's largest ATMD system to suppress the building vibrations. On-site forced vibration tests on the skyscraper were first conducted and the results showed that the ATMD system can increase the damping ratios of the fundamental sway modes up to about 11 times. Accordingly, ambient vibration tests on the building during Super Typhoon Hato were carried out, and the measured building acceleration responses showed that the ATMD system can effectively suppress the wind-induced vibrations of the skyscraper. Moreover, the structural damping ratios of the building with and without the operation of the ATMD system were identified, which showed that the ATMD system can significantly boost the damping ratios of the fundamental sway modes of the building for suppressing wind-induced vibrations, while it had limited effects on higher modal responses. The paper aims to provide useful information for the design of active vibration control systems and the wind-resistant design of high-rise buildings.

A robust adaptive control design for active tuned mass damper systems of multistory buildings

In this study, a robust adaptive controller is designed to be used in an active tuned mass damper system that can be used to damp undesired vibrations that occurred on the multistory buildings during the earthquake. To realize the controller design, all of the system parameters are assumed to be unknown, and the adaptive structure of the designed controller is obtained by designing adaptive compensation rules for system parameters. A backstepping control design approach is utilized for the control design by considering the appropriateness of the system’s structure of multistory buildings having an active tuned mass damper system at the top of the structure. The proposed control design is supported with a Lyapunov-based stability analysis where it is proven that the designed controller is able to protect the overall system’s stability while reaching the main control purpose. In addition to these, in the simulation studies realized for a nine-story building under the effect of a major earthquake, it is shown that the designed controller can be used to reach the main control purpose efficiently.

Dynamic Behavior of Supertall Building with Active Control System during Super Typhoon Mangkhut

This paper presents observations of structural dynamic characteristics and wind-induced responses of a 600-m-high skyscraper installed with an active tuned mass damper (ATMD) system during super typhoon Mangkhut. The structural dynamic characteristics (i.e., natural frequency, damping ratio, and mode shape) of the skyscraper are estimated along the structural modal directions based on the measurements during the typhoon, which are in good agreement with those determined by the finite element method and forced vibration test. The wind-induced responses and damping ratios of the skyscraper with and without the operation of the ATMD system are investigated, and the results show that the ATMD system can suppress the structural responses by mitigating the vibrations of the fundamental sway modes. Global damage evaluation indicates that there is no evident structural damage occurred on the skyscraper during the violent typhoon event. This paper aims to further the understanding of wind effects on supertall buildings under extreme wind conditions and provide useful information for the wind-resistant design and development of vibration control techniques for future skyscrapers.

Coupling ATMD System for Seismic Response Control of Two Adjacent Buildings

This study deals with optimal control of the coupling active tuned mass damper (ATMD) system for two neighboring structures under earthquake excitations. It also investigates the seismic performances of the proposed system including the issues on actuator failure problems. The conventional control approach is to use two ATMDs independently where each ATMD is individually installed at each structure without any connection between two structures. Since this uncoupling configuration does not allow transferring its control force to the other structure, it cannot adapt to emergency situation in which one of the two actuators becomes inoperable due to the power cuts or outages. On the other hand, the proposed control approach is to use a coupling ATMD system where two ATMDs with one mass being shared are installed to interconnect two structures. Hence, the proposed coupling ATMD system can transmit the control force of the remaining actuator to another structure through the interconnection configuration so that it can adapt to the one-side actuator failure. In a numerical example, the conventional independent and newly proposed coupling systems have been optimally designed to have similar control performance in normal operational conditions, and their performances have been compared to each other under the malfunction conditions of one-side actuator. Their comparative results verified the outstanding adaptive performance of the proposed coupling ATMD system over the independent ATMD system. The independent ATMD system showed considerably degraded control performance compared to its own normal control performance, whereas the proposed system exhibits much improved control performance over the independent ATMD system by fully utilizing the other normally operating actuators through the coupling configuration.

Modified sliding mode control of a seismic active mass damper system considering model uncertainties and input time delay

Model uncertainties and actuator delays are two factors that degrade the performance of active structural control systems. A new robust control system is proposed for control of an active tuned mass damper (AMD) in a high-rise building. The controller comprises a two-loop sliding model controller in conjunction with a dynamic state predictor. The sliding model controller is responsible for model uncertainties and the state predictor compensates for the time delays due to actuator dynamics and process delay. A reduced model that is validated against experimental data was constructed and equipped with an electro-mechanical AMD system mounted on the top storey. The proposed controller was implemented in the test structure and its performance under seismic disturbances was simulated using a seismic shake table. Moreover, robustness of the proposed controller was examined via variation of the test structure parameters. The shake table test results reveal the effectiveness of the proposed controller at tackling the simulated disturbances in the presence of model uncertainties and input delay.

Seismic control response of structures using an ATMD with fuzzy logic controller and PSO method

This study focuses on the application of an active tuned mass damper (ATMD) for controlling the seismic response of an 11-story building. The control action is achieved by combination of a fuzzy logic controller (FLC) and Particle Swarm Optimization (PSO) method. FLC is used to handle the uncertain and nonlinear phenomena while PSO is used for optimization of FLC parameters. The FLC system optimized by PSO is called PSFLC. The optimization process of the FLC system has been performed for an 11-story building under the earthquake excitations recommended by International Association of Structural Control (IASC) committee. Minimization of the top floor displacement has been used as the optimization criteria. The results obtained by the PSFLC method are compared with those obtained from ATMD with GFLC system which is proposed by Pourzeynali et al. and non-optimum FLC system. Based on the parameters obtained from PSFLC system, a global controller as PSFLCG is introduced. Performance of the designed PSFLCG has been checked for different disturbances of far-field and near-field ground motions. It is found that the ATMD system, driven by FLC with the help of PSO significantly reduces the peak displacement of the example building. The results show that the PSFLCG decreases the peak displacement of the top floor by about 10%-30% more than that of the FLC system. To show the efficiency and superiority of the adopted optimization method (PSO), a comparison is also made between PSO and GA algorithms in terms of success rate and computational processing time. GA is used by Pourzeynali et al for optimization of the similar system.

Robust multi-objective optimization design of active tuned mass damper system to mitigate the vibrations of a high-rise building

In engineering applications, many control devices have been developed to reduce the vibrations of structures. Active tuned mass damper system is one of these devices, which is a combination of a passive tuned mass damper system and an actuator to produce a control force. The main objective of this paper is to present a practical procedure for both deterministic and probabilistic design of the active tuned mass damper control system using multi-objective genetic algorithms to mitigate high-rise building responses. For this purpose, extensive numerical analyses have been performed, and optimal robust results of the active tuned mass damper design parameters with their effectiveness in reducing the example building responses have been presented. Uncertainties, which may exist in the system, have been taken into account using a robust design optimization procedure. The stiffness matrix and damping ratio of the building are considered as uncertain random variables; and using the well-known beta distribution, 50 pairs of these variables are generated. This resulted in 50 buildings with different stiffness matrices and damping ratios. These simulated buildings are used to evaluate robust optimal values of the active tuned mass damper design parameters. Four non-commensurable objective functions, namely maximum displacement, maximum velocity, maximum acceleration of each floor of the building, and active control force produced by the actuator are considered, and a fast and elitist non-dominated sorting genetic algorithm approach is used to find a set of pareto-optimal solutions.

Wind-Induced Motion Control of 76-Story Benchmark Building Using the Hybrid Damper-TLCD System

The tuned liquid column damper (TLCD) has recently been advanced for vibration control of structures subjected to wind loading. The effectiveness of the semiactive TLCD system and the hybrid viscous fluid damper-TLCD control system recently proposed by the writers is investigated for control of wind-induced motion of high-rise buildings. Simulations are performed on a 76-story building benchmark control problem subjected to wind tunnel test data and stochastic wind loads. It is shown that the semiactive TLCD control system performs comparably to a sample active tuned mass damper (ATMD) system and thus is an attractive alternative to the ATMD system. More significantly, it is shown that the hybrid viscous fluid damper-TLCD system reduces the response of the building substantially more than the semiactive TLCD system at every natural frequency of the building. Furthermore, the hybrid damper-TLCD system is robust in terms of the stiffness modeling error for control of both displacement and acceleration responses. The simulation results show that the proposed hybrid viscous fluid damper-TLCD system can perform effectively under various wind loading conditions.

Wavelet-Hybrid Feedback-Least Mean Square Algorithm for Robust Control of Structures

In a companion article, the writers presented a hybrid feedback-least mean square (LMS) algorithm for control of structures through integration of a feedback control algorithm such as the linear quadratic regulator and linear quadratic Gaussian algorithms and the filtered-x LMS algorithm. Low-pass filtering of dynamic environmental disturbance signals due to winds and earthquakes is required when the hybrid feedback-LMS algorithm is used for control of civil structures, because the frequency bandwidths of such environmental signals are much wider than those of common structural systems. In this paper, it is shown that the wavelet transform can be used as an effective filtering scheme for control problems. A wavelet-hybrid feedback-LMS algorithm is presented for robust control of civil structures. The effectiveness of the proposed control model is demonstrated by application to an active tuned mass damper system and an active mass driver benchmark problem. Simulation results demonstrate that the proposed model is effective for control of both steady and transient vibrations without any significant additional computational burden, and can be used readily to enhance the performance of existing feedback control algorithms.

Hybrid Feedback-Least Mean Square Algorithm for Structural Control

Classical control algorithms such as the linear quadratic regulator (LQR) and linear quadratic Gaussian (LQG) algorithms have been used for structural control problems over the past three decades. These algorithms suffer from a number of fundamental shortcomings. They are susceptible to parameter uncertainty and modeling error. They present optimum solutions in a narrow sense only because the external excitation term is ignored in their formulation and solution. These algorithms achieve a significant level of attenuation in the vicinity of the natural frequencies of the structure. But, they fail to suppress the vibrations when frequency of the external disturbance differs even slightly from the natural frequencies of the structure. In this paper, a hybrid feedback-least mean square (LMS) algorithm is presented for control of structures through integration of a feedback control algorithm such as the LQR or LQG algorithm and the filtered-x LMS algorithm. The algorithm is applied to the active tuned mass damper system. It is shown that the hybrid feedback-LMS algorithm minimizes vibrations over the entire frequency range and thus is less susceptible to modeling error and inherently more stable.

Optimal Damper Characteristics of ATMD for Buildings under Wind Loads

Recently, Ankireddi and Yang derived analytical expressions for the damper characteristics and the controller feedback gain coefficients for the design of an active tuned mass damper system (ATMD) in reducing the first-mode response of buildings under wind loads. These expressions allow one to determine the optimal feedback gains that define the control force. The derivation is based on the simplifying assumption of white-noise excitation to represent the wind loads. This paper examines the accuracy of their expressions when applied to more sophisticated mathematical models for wind loadings. The H-rms norm control technique, in conjunction with the GRG algorithm, is used to obtain the optimal values of these damper characteristics and the controller feedback gain coefficients under both along-wind and across-wind excitations. The results furnished by Ankireddi and Yang expressions are then compared with the present results. For general application, the study covers a wide range of rectangular section buildings by considering representative buildings of very short to very tall ones. It was found that the expressions were reasonably accurate in the case of along-wind excitation. However, the expression for the damper frequency ratio has to be significantly modified for the case of across wind excitation. The final expressions given herein should be useful in giving the optimal feedback gains for the control force to be used in the design of ATMD system for vibration control of structures under along- and across-wind excitations.

COMPOSITE MASS DAMPERS FOR VIBRATION CONTROL OF WIND-EXCITED TOWERS

Various systems for controlling the vibrations of tall buildings subjected to earthquakes or strong winds have been developed and applied over the past few years. This paper is concerned with the use of a composite active–passive tuned mass damper (APTMD) system for the vibration control of a single-degree-of-freedom tower under the along-wind and the across-wind excitations, respectively. The effectiveness of this relatively new composite tuned mass damper system is investigated and compared with the more well-known active tuned mass damper system. The results show reductions in the wind-induced displacement responses of the towers are greater with APTMD if the appropriate damper and control parameters are selected. More importantly, these better performances may be achieved with a relatively smaller mass for the active part of the control. Such a smaller active damper mass is advantageous for installation purposes. The parametric studies conducted herein also show that the APTMD system is not so sensitive to the small variations of the structure–damper mass ratio, the frequency ratio and damping factor of the damper. These APTMD characteristics are useful in design.