Active Vibration Control Of Structures Research Articles

Hybrid Active Vibration Control of Helicopter Fuselage Driven by Piezoelectric Stack Actuators

The vibration loads of a helicopter rotor are transmitted to the fuselage through gearbox support struts and cause severe vibration of the fuselage. A piezoelectric stack actuator has the advantages of light weight, a large driving force, small driving displacement, a wide working frequency range, and a fast response speed; it is an ideal actuator for the active vibration control of structures. The piezoelectric stack actuators are installed on the gearbox support struts, which can effectively control the vibration of the helicopter fuselage. In this paper, the dynamic models of the piezoelectric stack actuators, the rotor/gearbox, the gearbox support struts, and the fuselage coupling system are established. Combining the adaptive harmonic synchronization identification and updating algorithm with the sliding-mode algorithm, the adaptive harmonic feedforward/sliding-mode feedback hybrid active control method for helicopter fuselage vibration is proposed. The simulation results show that, under the excitation of the rotor vibration loads with the first three rotor passing frequencies, the acceleration responses of the fuselage in three directions by using the proposed hybrid active control method are reduced by more than 98%; when the amplitudes, phases, and frequencies of the vibration loads are changed, the active control of the fuselage vibration by using the hybrid active control method has a fast convergence speed and a strong adaptive ability.

Multi-channel adaptive active vibration control of piezoelectric smart plate with online secondary path modelling using PZT patches

Abstract Reducing the vibration of smart structures based on adaptive active vibration control (AAVC) has been extensively studied in recent years, because it is a light weight and effective method for reducing low-frequency structural vibrations. The multi-channel AAVC methodology based on the filtered-X least mean square (FXLMS) algorithm is widely implemented in active control applications owing to its self-adjustment ability to adapt to dynamically varying structures. In this paper, a new multi-channel FXLMS with online secondary path modelling (SPM) is designed based on the auxiliary random noise technique. Through a defined indirect error signal, the proposed variable step-size (VSS) strategies can ensure that every online SPM filter and every active control filter have their own exclusive step size to update the coefficients. Moreover, the proposed auxiliary noise power scheduling (ANPS) strategy can ensure that the variation rules of auxiliary noise power applied to different secondary paths are different. A complete multi-channel AAVC real-time experimental system based on NI compact RIO is set up to conduct the experimental investigation. A series of AAVC control experiments on a piezoelectric smart cantilever plate with PZT sensors and actuators are conducted to demonstrate the validity and efficiency of the proposed method. The experimental results show that the vibration of the smart cantilever plate could be effectively attenuated with a high convergence rate. The proposed methodology has an important advantage in applications where active vibration control of piezoelectric smart structures is required.

Active vibration control of a hoop truss structure with piezoelectric bending actuators based on a fuzzy logic algorithm

Active vibration control of large flexible space structure is a challenging topic in the system dynamics and control of spacecraft. This paper proposes a novel approach for vibration control on a large hoop truss structure, typically used as mesh satellite antenna. First, to suppress the first-order bending modal response of the hoop truss structure with an initial disturbance, a piezoelectric bending actuator with excellent bending actuation performance was carefully designed as a key component of an active vibration control system. Then, the actuating characteristics of the actuator and the dynamic equations of the active structure were analyzed and formulated based on a finite element method. In order to improve the vibration-attenuating effect of the control system, a Mamdani-type fuzzy logic algorithm was employed in a closed-loop control system. Finally, simulations and experiments were implemented to validate the effectiveness of the proposed active control approach and structure. The experimental results showed that the decay time of first-order bending modal response (around 0.34 Hz) of control system reduces by 75% compared with that of the uncontrolled system. The results demonstrate that the proposed active vibration control system has good application potential in controlling the bending modes of a large flexible spacecraft.

비공진 주파수로 가진 되는 구조물의 능동 진동 제어를 위한 다중 입력 다중 출력 fxLMS 알고리듬

비공진 주파수로 가진 되는 구조물의 능동 진동 제어를 위한 다중 입력 다중 출력 fxLMS 알고리듬

A combined approach for active vibration control of fluid-loaded structures using the receptance method

A combined experimental–numerical approach for the pole assignment of fluid-loaded structures using the receptance method is proposed in this paper. The in-air measurements of structural receptances and numerically simulated fluid loading computed using acoustic boundary element analysis are combined to obtain the receptances of the fluid-loaded structures. It does not require evaluating the fluid-loaded model which usually contains errors, and it does not require receptance measurements of the fluid-loaded structure which are usually difficult and time-consuming. A partial pole assignment can also be achieved with the combined approach. The accuracy and efficiency of the proposed combined approach are demonstrated on a water-loaded plate. Numerical results indicate that the chosen poles of the water-loaded plate can be assigned to the predetermined values with the proposed approach, and the in-air mode shapes may represent the water-loaded mode shapes in the combined approach for suppression of spillover.

Wave based active vibration control of a membrane antenna structure

This paper studies the wave based active vibration control of a membrane antenna structure. The membrane antenna structure studied in this paper has a great prospect in aerospace engineering. First, the dynamic model of the membrane antenna structure is established based on the finite element method. Then, based on the hypothesis of modal excitation mechanism, a wave-based controller is designed using the wave attenuation method. This method does not depend on the wave transfer function of the structure, so it can be applied to structures with complex shapes and boundaries. At last, the validity of the presented controller is verified through numerical simulations. Simulation results indicate that the dynamic behavior of the membrane antenna structure shows obvious wave characteristics; the presented controller can suppress the vibration of the structure effectively through holding back the formation of standing waves, and better control effect can be obtained when the actuators are placed near to the excitation point.

Modeling and active vibration control of lattice grid beam with piezoelectric fiber composite using fractional order PDμ algorithm

One of challenging issues in structural dynamics is to accurately and rapidly control the vibration levels. It is even important to minimize the occurrence of structural failure in lightweight design. As smart sensors or actuators, the new piezoelectric fiber composite are able to coat onto large area in flexible smart structures, and also has large actuating force. But little is known about the performance of the piezoelectric fiber composite on active vibration control of lattice sandwich structure. In this paper, a novel fractional order PDμ control of lattice grid beam with piezoelectric fiber composite face sheets is proposed. Firstly, the dynamic model and the vibration responses of the smart sandwich structure are obtained on the basis of the third order shear deformation theory. The ply pattern of piezoelectric fiber composite and structural damping are taken into account for more accurately predict the dynamic behavior. Then, a new active control method by using the fractional order PDμ algorithm is presented, and simulations of vibration control of the lattice grid beam subjected to various dynamic loadings are conducted, such as initial disturbance, harmonic excitation, step excitation and explosive impact excitation. Consequently, it is proved that the fractional order PDμ control can reduce the vibration amplitude of lattice grid beam more significantly and more rapidly, by comparing its numerical results with those of the integer order PD algorithm and uncontrolled results.

Nonprobabilistic Reliable LQR Design Method for Active Vibration Control of Structures with Uncertainties

The linear quadratic regulator (LQR), which allows a natural consideration of the constraints on state variables and control effort, is widely used in modern control theory for the active control of structural vibration. However, uncertainties are unavoidable in the design of active control systems. Thus, in the design process of an LQR controller, it is important to deal with these uncertainties, which are always bounded and have a great influence on the final performance of the closed-loop system. In this paper, the nonprobabilistic reliability concept is extended to the selection of weighting matrices for determining the LQR controller. First, a new uncertainty propagation analysis method for an active control system is presented. To adapt to the special problem of controller design, a novel nonprobabilistic reliability index is proposed. The reliability and safety margin of the closed-loop system can be continuously characterized by this modified nonprobabilistic reliability index. The weighing matrices used to design the LQR controller via the Riccati equation are finally determined by solving a reliability-based optimization problem. The proposed method preserves the excellent characteristics of LQR control theory and provides a quantitative method for selecting the weight matrices for LQR controller design in consideration of the inherent uncertainties. Two numerical examples are presented to demonstrate the effectiveness and feasibility of the proposed method. The results from these examples reveal that the uncertainties in active control system design can be addressed from a reliability perspective.

Simultaneous optimization of piezoelectric actuator topology and polarization

This article addresses the problem of piezoelectric actuator design for active structural vibration control. The topology optimization method using the Piezoelectric Material with Penalization and Polarization (PEMAP-P) model is employed in this work to find the optimum actuator layout and polarization profile simultaneously. A coupled finite element model of the structure is derived assuming a two-phase material, and this structural model is written into the state-space representation. The proposed optimization formulation aims to determine the distribution of piezoelectric material which maximizes the controllability for a given vibration mode. The optimization of the layout and poling direction of embedded in-plane piezoelectric actuators are carried out using a Sequential Linear Programming (SLP) algorithm. Numerical examples are presented considering the control of the bending vibration modes for a cantilever and a fixed beam. A Linear-Quadratic Regulator (LQR) is synthesized for each case of controlled structure in order to compare the influence of the polarization profile.

Optimisation of a PID controller for a two-floor structure under earthquake excitation based on the bees algorithm

The control of vibration and displacement in structures under seismic excitation is very challenging, and designing a structural control system against disturbances has drawn great attention. This paper concentrates on implementing the bees algorithm to tune gains of traditional PID controller for active vibration control of a building-like structure with two floors under Northridge Earthquake excitation. Bees algorithm is a diverse method to ensure an efficient solution for optimisation of a controller according to customary trial-error design methods. The main aim of this study is optimisation of KP, KI and KD gains with bees algorithm in order to obtain a more effective PID controller to suppress vibrations of the floors during the earthquake excitation. After definition of the system and bees algorithm, PID controller offline tuned with bees algorithm using mathematical model of system. Moreover, the aim is to compare the performances of the BA with an existing optimisation method, genetic algorithm (GA), implemented on the system. The paper presents the experimental results that were obtained from the structure system to show the efficiency of the tuned PID controller. As a result, the performance and effectiveness of the tuned PID controller are investigated and verified experimentally. The displacements and accelerations of the floors and the cart are decreased considerably. The experimental responses of the system are given in graphical form.

Experimental study of active vibration control for suppressing impact or moving disturbance-induced vibrations with polyvinylidene fluoride and fiber Bragg grating sensors

In this work, we experimentally study active vibration control of a smart cantilever beam and focus on influences of disturbances to the vibrations and corresponding control performances. The smart cantilever beam is subjected to impacts or moving mass loadings and robust positive position feedback (PPF) control is implemented to suppress the disturbance-induced vibrations. Specifically, we employ high sensitive polyvinylidene fluoride (PVDF) and fiber Bragg grating (FBG) sensors to capture dynamic characteristics of the disturbances. To allow repeatable and controllable experimental conditions for the prescribed disturbances, steel balls or a steel rod are used as the sources of the disturbances applied on the cantilever beam, on which a rail is cut out to guide the motions of the steel ball. Before designing PPF, finite element simulations are carried out to numerically compare sensing performances of the PVDF and FBG sensors. Resonant frequencies of the cantilever beam, including bending, torsional, and lateral modes, are also obtained beforehand numerically and experimentally for understanding behaviors of the disturbance-induced vibrations. By performing fast Fourier transform (FFT) and short-time Fourier transform (STFT) on the detected transient responses, characteristics of the disturbances and their suppressions with the PPF controllers are demonstrated and discussed. The proposed smart cantilever beam with the prescribed repeatable and controllable disturbances serves as a very suitable model in laboratory confirmations for active controller designs. In addition, our experimental work provides suggestions for sensor selections in active vibration control of flexible structures, especially in environments involving impact or moving disturbances.

Piezoelectric Actuator Placement Optimization and Active Vibration Control of a Membrane Structure

The placement optimization of piezoelectric actuators and active vibration control of a membrane structure are studied in this paper. The classical linear quadratic regulator controllers are designed to suppress the unwanted vibration. Simulation results indicate that the optimal locations of piezoelectric actuators are affected deeply by the additional mass and stiffness of actuators, the computational efficiency of particle swarm optimizer is higher than that of genetic algorithm for this particular problem, and the control performance of optimally placed actuators is better than that of non-optimally placed actuators.

A method for bidirectional active vibration control of structure using discrete-time sliding mode

In this paper, a novel discrete-time sliding mode control is proposed in order to attenuate structural vibration due to earthquake forces. The analysis is based on the lateral-torsional vibration under the bidirectional waves. The proposed fuzzy modeling based sliding mode control can reduce chattering due to its time-varying gain. In the modeling equation of the structural system, the uncertainty exists in terms of sti¤ness, damping forces and earthquake. Fuzzy logic model is used to identify and compensate the uncertainty associated with the modeling equation. We prove that the closed-loop system is uniformly stable using Lyapunov stability analysis. The experimental result reveals that discrete-time sliding mode controller offers significant vibration attenuation with active mass damper and torsional actuator.

Active Vibration Control of Structures with DEA

Active Vibration Control of Structures with DEA

Recent Studies on Vibrational Energy Harvesting of PZT Materials

Lead Zirconate Titanates (PZTs) are piezoelectric materials which produce electric charges on application of mechanical stress (direct effect) or undergo dimensional change when subjected to an electric field (converse effect). PZTs are most widely used as sensors and actuators for active vibration control of aero structures, structural health monitoring (SHM), precision opening and closing of valves, sonar transducer etc. In recent years, the direct piezoelectric effect has been used for vibration energy harvesting. For example, PZT discs embedded in a shoe produce electric charges during walking which are used for charging of mobiles. Similarly, PZT tiles laid down on roads produce electric energy due to movement of vehicles and the energy is used for lighting street lights. The energy generated using PZTs are in the range of mico to milli watts, suitable for powering low power electronic devices such as wireless sensor networks. At CSIR-NAL, PZT materials are prepared in-house and different types of devices eg. unimorphs, bimorphs and multi-layered (ML) stacks are fabricated. In recent years, the devices are used for energy harvesting studies at RWRDC, HAL, Bangalore. The output voltage obtained from PZT unimorphs (5V) was more compared to energy produced from bimorphs and ML stacks. Also, PZT unimorph with large surface area produce more output voltage.

Infinite-dimensional Kalman filter design for flexible curved beams based on PDE models

State observer design is a crucial step in active vibration control of large flexible space structures (LFSSs). Since the LFSSs often have lower natural frequencies, high modal density and low damping, the traditional observer design methods which use the modal truncation model are easily leading to the problem of observation spillover. Instead, the approaches directly using the partial differential equation (PDE) models of flexible structures can avoid the spillover problem, and are becoming the hotspot of research in this field. The presented research aimed at the flexible curved beams which are often used as support components in space antennas, and designed the infinite dimensional state observer for the in-plane vibration of cantilevered curved beams with weakly internal damping based on the theory of Kalman filtering. Firstly, a second order PDEs model for the in-plane vibration of the curved beam is established which considers the shear deformation and rotary inertia of the curved beam simultaneously, then by using the variable substitution method, the second order PDEs model is reduced to first order and transformed to an abstract state space model (SSM) in Hilbert space. The infinite-dimensional Kalman filter for the curved beam is designed using the SSM, and the explicit formula for the feedback gain operators of the Kalman filter are obtained based on the spectral factorization method in frequency domain. Finally, a numerical example is carried out to validate the effect of the presented infinite dimensional Kalman filter design method, and to reveal the effectiveness of the method on preventing the observation spillover.

Dynamic model and active vibration control of a membrane antenna structure

This paper studies a dynamic model and active vibration control of a membrane antenna structure. Based on the finite element method (FEM), the dynamic model of the membrane antenna structure is established. Piezoelectric actuators are used to suppress the vibration of the structure and their optimal locations on the membrane are determined using the optimization method, where an efficient numerical criterion depended on controllability Grammian is used as optimization criterion and the particle swarm optimizer (PSO) is used as optimization algorithm. Active controllers are designed by the classical linear quadratic regulator (LQR) method. Simulation results indicate that the vibration modes and dynamic responses obtained by the dynamic model established in this paper coincide well with the results of the software ABAQUS; vibration of the structure can be suppressed effectively by the piezoelectric actuators, and optimal placed actuators not only can produce better control effectiveness but also need smaller control cost.

The low frequency vibration control of the hoop truss structure with extended arm

The hoop truss structure with extended arm has large diameter and great flexibility. These two characteristics cause low frequency and affect the technical requirements of modern satellite system. This article investigates the active vibration control of the hoop truss structure with extended arm. At first, proportional plus derivative algorithm and least mean square adaptive filtering algorithm are applied to derive the vibration control equation. Then, based on the first two modes calculated by finite elements method, the positions of the actuators are optimized. Finally, the excitation simulation and the closed-loop control simulation for suppressing the low frequency vibration are established. The simulation result illustrates that the amplitudes of the responses are decreased significantly under the steady state excitation after adopting the intelligent control algorithm.

柔軟構造物のアクティブ振動制御における最近の動向 : マス・バネ・ダンパ系にみるモード制御法と波動制御法

柔軟構造物のアクティブ振動制御における最近の動向 : マス・バネ・ダンパ系にみるモード制御法と波動制御法

Analysis of sensor-debonding failure in active vibration control of smart composite plate

In this article, the effect of a sensor-debonding failure on the active vibration control of a smart composite plate is investigated numerically. A mathematical model of the smart structure with a partially debonded piezoelectric sensor is developed using an improved layerwise theory, a higher-order electric-potential field that serves as the displacement field, and the potential variation through the piezoelectric patches. A state-space form that is based on the reduced-order model is employed for the controller design. A control strategy with a constant gain and velocity feedback is used to assess the vibration-control characteristics of the controller in the presence of the sensor-debonding failure. The obtained results show that sensor-debonding failure reduces the sensor-output, control-input signal, and active damping in magnitude that successively degrades the vibration attenuation capability of the active vibration controller. The settling time and relative tip displacement of the controlled structure increase with the increasing length of partial debonding between the piezoelectric sensor and host structure. Furthermore, a damage-sensitive feature along with multidimensional scaling showed excellent results for the detection and quantification of sensor-debonding failure in the active vibration control of smart structures.