Active Vibration Control Method Research Articles

System Identification and Fractional-Order Proportional–Integral–Derivative Control of a Distributed Piping System

The vibration of piping systems is one of the most important causes of accelerated equipment wear and reduced work efficiency and safety. In this study, an active vibration control method based on a fractional-order proportional–integral–derivative (PID) controller was proposed to suppress pipeline vibration and reduce pipeline damage. First, a mathematical model of the distributed piping system was established using the finite element analysis method, and the characteristics of the distributed piping system were studied effectively. Further, the time-frequency domain parameter identification method was used to realise the system identification of the cross-point vibration transfer function between the brake and sensor, and the particle swarm optimisation algorithm was utilised to further optimise the transfer function parameters to improve the system identification accuracy. Therefore, a fractional-order PID controller was designed using the D-decomposition method, and the optimal controller parameters were obtained. The experimental and numerical simulation results show that the improved system identification algorithm can significantly improve modelling accuracy. In addition, the designed fractional-order PID controller can effectively reduce the system’s overshoot, oscillation time, and adjustment time, thereby reducing the vibration response of piping systems.

Active vibration control of fluid-conveying pipelines: Theoretical and experimental studies

For the fluid-conveying pipeline with macro-fiber composites (MFC), relevant dynamic modeling and experimental testing studies are rarely found in previous papers. Therefore, this paper has carried out related research work. Firstly, considering the fluid-structure interaction and piezoelectric effects, a semi-analytical modeling method for the fluid-conveying pipeline with MFC attaching to any position is proposed. A new Runge-Kutta-Gear (RKG) time-domain solution method is presented for solving state-space equations with the characteristics of rigid equations, and the design methods of Linear-Quadratic Regulator (LQR) controller and Proportional-Integral-Derivative (PID) controller are introduced, respectively. Secondly, an experimental system for active control and vibration test is built, and the dynamic model and control method are verified by experiments and simulations. Finally, the influence of relevant control parameters in the controller on the active control effect is discussed, and the influence law of fluid parameters such as fluid velocity and fluid pressure on the active control is also clarified. The novelty of this work is that the active vibration control and solution methods for the fluid-conveying pipeline with MFC are proposed, and the feasibility of MFC for pipeline vibration suppression is verified by experiments, which provides a new technical idea for the vibration reduction design of the fluid-conveying pipeline.

A Study on Influence of Flapping Dynamic Characteristics on Vibration Control of Active Rotor with Trailing-Edge Flaps

An active rotor with trailing-edge flaps (TEFs) is an effective active vibration control method for helicopters. Blade flapping dynamic characteristics have a significant effect on the active vibration control performance of an active rotor. In this study, an aeroelastic model is developed using the Hamilton principle, and a quasi-steady Theodorsen model for the airfoil with a TEF is utilized to calculate the aerodynamic loads induced by the dynamic deflection of TEFs. The accuracy of this model is validated through a comparison with the CAMRAD calculation and flight test results of a SA349/2 helicopter. Based on the modal orthogonality and the equilibrium equation of the blade flapping motion, the method of changing the blade flapping dynamic characteristics is obtained. Blade sectional characteristics are adjusted to study the effect of blade flapping dynamics on the vibration control authority of an active rotor. The simulation results demonstrate that if the modal frequency of second-order flap is tuned to close to the rotor passage frequency, the flapping dynamic characteristics are capable of enhancing the vibration control performance of the active rotor.

Ultra-low frequency active vibration isolation in high precision equipment with electromagnetic suspension: Analysis and experiment

High performance vibration isolation requirement in the ultra-low frequency band for high precision equipment becomes more and more stringent. An active vibration isolation method is investigated to broaden the frequency band of isolation and improve the performance, in which an electromagnetic suspension is adopted to provide a static lifting force and an active control force. Naturally, the suspension is accompanied by a controllable negative stiffness. Two factors that might cause instability of the suspension system, i.e., the bias current and the base disturbance, are analyzed to give the stable region. The matching relationship between the currents in the upper and lower coils, and the mapping rules among the current, relative displacement, force and stiffness are discussed, respectively. The maximum base disturbance that the system can withstand is analyzed. On the basis of the theoretical analysis, the active position stabilization and vibration control methods are built and the performance is evaluated. Furthermore, experiments were conducted to verify the effectiveness of the active vibration isolation method. Numerical and experimental results demonstrate that the electromagnetic suspension is able to improve the vibration isolation performance in the ultra-low frequency range, where the transmissibility is below 0 dB in the entire frequency band and the initial vibration isolation frequency is less than 1Hz.

Active Global Vibration Control of Helicopter Fuselage

Active control of structural response (ACSR) has been widely used to suppress helicopter fuselage vibration due to its advantages. However, ACSR, by taking the vibration responses at target measurement points as the active control objective, is a local vibration control method for the fuselage. In this paper, an active global vibration control (AGVC) method for the fuselage by taking the vibratory loads transmitting to the fuselage through gearbox struts as the active control objective is proposed. By installing piezoelectric stack actuators on a gearbox strut, the active strut is formed and its electromechanical coupling equation of motion is derived. The AGVC model, algorithm, convergence, and system for a dynamically similar frame structure of a helicopter fuselage are presented. The simulation results indicate that AGVC can suppress the global vibration of the fuselage under the excitation of the rotor vibratory loads more effectively with faster convergence speed than ACSR. The vibration at the target measurement points in ACSR can be effectively reduced, but the control effect at other positions is not satisfied, and even the vibration at some positions is larger than that in control off.

실시간 상태-공간 식별 기반 제어기를 이용한 유한 국부공진 메타물질 평판의 적응형 진동 저감

To improve the internal sound quality of an electric vehicle, the noises (tire and road noises), vibration, and discomfort should be reduced effectively. Compared to the conventional damping materials, the locally resonant metamaterial is advantageous in terms of reducing the vibration in the low frequency band and reducing the weight through a stop band, where vibration is not transmitted. However, the locally resonant metamaterial installed in a finite structure fails to form an ideal stop band. Additionally, there is a problem of occurrence vibration mode at an arbitrary frequency. Accordingly, there is a need for an active vibration control method capable of learning and actively reducing the vibration modes occurring at arbitrary frequencies within the stop band in real-time. In this study, a real-time state-space identification-based active vibration control method was proposed to reduce the vibration modes occurring at arbitrary frequencies within the stationary band of local resonance metamaterials. The active vibration control method proposed in this study, combined with the existing passive vibration reduction method, can be utilized to effectively reduce the vibration for random disturbance of a fluctuating system.

Review on Active Vibration Control Method of Magnetically Suspended System

Review on Active Vibration Control Method of Magnetically Suspended System

A Review Paper on Comparative Analysis on RCC Structure with Energy Dissipation Device and Composite Structure

Abstract: In recent years considerable attention has been paid to research and development of structural vibration control devices with particular emphasis on mitigation of wind and seismic response of buildings. Many vibration-control measures like passive, active, semi-active and hybrid vibration control methods have been developed. Base isolation is a passive vibration control system. The isolator partially reflects and partially absorbs input seismic energy before it gets transmitted to the superstructure. Lead rubber bearing isolators are placed between the superstructure and foundation, which reduces the horizontal stiffness of the system. It thereby increases the time period of the structure and decreases the spectral acceleration of the structure. The superstructure acts like a rigid body, thus inter storey drift is reduced. This study is concerned with the effects of various vertical irregularities on the seismic response of a structure and controls this response using base isolation. The objective of the study is to carry out response spectrum analysis. The predominant lateral loads acting upon building structures are earthquake and wind induced forces. If wind load is much greaterthan earthquake load, the lateral force resisting system required to tackle wind loading may be enough to resist the smaller earthquake load. In this situation, a seismic base isolator will not bring any benefit to the building system. Furthermore, if time period of a building without isolator is greater, incorporation of isolator will not bring much difference to the building behavior with respect to seismic load. Additionally, for buildings with lowerstructural time periods, incorporation of an isolator will greatly alter the seismic behavior

Active vibration control of a piezoelectric composite laminate

An active vibration control method of the piezoelectric composite laminated plate under the external disturbance is studied. Firstly, the dynamic model of the piezoelectric composite laminated plate is derived based on the classical laminated plate theory and the Hamilton's principle. And subsequently, a sliding mode observer is developed for the external disturbance, and the stability of the observer is verified by the Lyapunov equation, and also the LQR controller is designed based on the observed state. The particle swarm algorithm is adapted to optimize the weighting matrix. In the end, the impacts of the geometric parameters and the stacking sequences on the dynamic behavior of the piezoelectric composite material plate is analyzed. Results indicate that the sliding mode observer can accurately track the original state, and the vibration of the piezoelectric composite material plate can be suppressed effectively by the LQR control based on the particle swarm

Stability control method of double crystal monochromator based on hybrid control algorithm

The Bragg angle stability of the DCM (double crystal monochromator) in synchrotron radiation facilities is critical for beam position, flux and resolution of hard X-ray beam lines. Generally, the vibration caused by LN2 cooling system is the most critical factor affecting the stability of DCM. In this paper, aiming at the stability of DCM, we propose the stability control method of double crystal monochromator base on hybrid control algorithm. The numerical results show that the stability of the DCM in the pitch direction can be greatly improved by this active vibration control method under LN2 mode. The angular displacement RMS value in the pitch direction decreased from about 358.52 nrad to about 0.071nrad, which decreased by 99.98%. Proposed method is of great significance to the research of ultra-high stability DCM in synchrotron radiation facilities all over the world.

Active vibration control of heavy platform-struts structure

To tackle the active control problem of the heavy platform-struts structure, this paper designs a kind of hydraulic servo actuator that can withstand large static load and generate high-precision, small-amplitude dynamic forces as well, and develops a multi-channel cross-coupling suppression control algorithm that can consider the strong coupling effect in structure. Subsequently, combining the designed actuators with the control algorithm, this paper puts forward an active heavy platform-struts structure vibration control method. By embedding the designed actuators into the support struts, a platform-struts structure experimental system is constructed to assess the vibration suppression effect of the proposed method. Excited by the amplitude-varying disturbing force, four different kinds of experiments are conducted. The experimental results show that the distributed multi-channel adaptive active control method without considering the coupling effect will lead to the instability, and the vibration attenuation of the proposed method in this paper exceeds 90%. The proposed method therefore has an important potential in addressing the problem of vibration suppression in the practical engineering. In addition, it has strong convergence and robustness.

Nonlinear ESO-based vibration control for an all-clamped piezoelectric plate with disturbances and time delay: Design and hardware implementation

Considering the problems of model uncertainties, higher harmonics, uncertain boundary conditions, external excitations, and system time delay in practical vibration control system, a novel active vibration control method is proposed to suppress the vibration of a thin plate structure with acceleration sensor and piezoelectric bimorph actuator in this paper. First, a nonlinear extended state observer (NESO)-based controller is designed to ensure the anti-disturbance performance of the structural vibration control system. Then, an enhanced differentiator-based time delay compensation method is introduced to improve the vibration suppression performance of the NESO-based controller. A real time hardware-in-the-loop benchmark for an all-clamped piezoelectric thin plate is designed to verify and compare the performance of the developed controller against conventional ESO-based methods (linear ESO with/without time delay compensation, NESO without time compensation). The best vibration suppression and disturbance rejection performance of the proposed NESO-based controller with an enhanced time delay compensator is verified in the comparative experimental results. This work is able to provide practitioners with vital guidance in designing active vibration control system in the presence of disturbances and time delay.

A new active vibration control method of double crystal monochromator based on FuLMS-ADRC hybrid algorithm

The stability of crystal monochromator is the main technical bottleneck of the overall performance of X-ray beam. Generally, in the field of synchrotron radiation, the stability of double crystal monochromator (DCM) is guaranteed by passive vibration control method. In this paper, we propose a new active vibration control method of DCM based on FuLMS-ADRC hybrid algorithm. The angular stability of DCM in the pitch direction is improved from 352.24 nrad to 3.07 nrad (LN2 cooling cycle) by the active vibration control method. This new active vibration control method based on FuLMS-ADRC hybrid algorithm not only provides a new technical scheme to improve the overall performance of hard X-ray beam, but also is of great significance to realize the nano-radian stability index of the fourth-generation synchrotron radiation beam optical equipment.

Active Vibration Control on a Smart Composite Structure Using Modal-Shaped Sliding Mode Control

Abstract This article proposes an active modal vibration control method based on a modal sliding mode controller applied to a smart material composite structure with integrated piezoelectric transducers as actuators and sensors. First, the electromechanical coupled system is identified using a modal reduced-order model. The sliding surface is based on the modal-filtered states and designed using a general formulation allowing the control of multiple vibration modes with multiple piezoelectric sensors and actuators. The performance and stability of the nonlinear controller are addressed and confirmed with the experimental results on a composite smart spoiler-shaped structure. The nonlinear switching control signal based on the modal-shaped sliding surface improves performances of the linear part of the control while maintaining not only stability but also robustness. The attenuation level achieved on the target modes on all piezoelectric sensors starts from −14 dB up to −22 dB, illustrating the strong potential of nonlinear switching control methods in active vibration control.

Theoretical and experimental studies of an effective active vibration control method based on the deflection shape theory and optimal algorithm

Similar to mode shapes, deflection shapes are distributions of vibration amplitudes on structures under non-resonant excitations. Therefore, they are also essential vibration characteristics of structures. This paper proposes an effective active vibration control method under both non-resonant and resonant excitations based on the deflection shape theory and optimal algorithm. Taking the vibration isolation of an object on a flat plate as an example, the active vibration control method is illustrated. Piezoelectric patches are used as sensors and actuators. The main idea of the present vibration control method is to construct the suitable deflection shapes according to the position of the object by using the genetic algorithm (GA). There are two methods to select the desired deflection shapes. Under non-resonant external excitations, the desired deflection shapes are assumed artificially based on the idea of mode localization. While under resonant excitations, the desired deflection shape will be determined by the concept of destructive interference, that is, it should be completely opposite to the original one. In order to make the structure vibrate according to the desired deflection shape, piezoelectric materials are used to obtain the active loads or stiffness. The optimal actuating voltages and feedback control gains in the active control will be determined by GA. The effects of these active vibration control methods are investigated through the theoretical analyses, numerical simulations, as well as experimental verifications. These results demonstrate that the present active control method is effective.

Recent Advances in Vibration Control Methods for Wind Turbine Towers

Wind power is a substantial resource to assist global efforts on the decarbonization of energy. The drive to increase capacity has led to ever-increasing blade tip heights and lightweight, slender towers. These structures are subject to a variety of environmental loads that give rise to vibrations with potentially catastrophic consequences, making the mitigation of the tower’s structural vibrations an important factor for low maintenance requirements and reduced damage risk. Recent advances in the most important vibration control methods for wind turbine towers are presented in this paper, exploring the impact of the installation environment harshness on the performance of state-of-the-art devices. An overview of the typical structural characteristics of a modern wind turbine tower is followed by a discussion of typical damages and their link to known collapse cases. Furthermore, the vibration properties of towers in harsh multi-hazard environments are presented and the typical design options are discussed. A comprehensive review of the most promising passive, active, and semi-active vibration control methods is conducted, focusing on recent advances around novel concepts and analyses of their performance under multiple environmental loads, including wind, waves, currents, and seismic excitations. The review highlights the benefits of installing structural systems in reducing the vibrational load of towers and therefore increasing their structural reliability and resilience to extreme events. It is also found that the stochastic nature of the typical tower loads remains a key issue for the design and the performance of the state-of-the-art vibration control methods.

Vibration Control of a Two-Link Flexible Robot Arm with Time Delay through the Robust Receptance Method

This paper proposes a method for active vibration control to a two-link flexible robot arm in the presence of time delay, by means of robust pole placement. The issue is of practical and theoretical interest as time delay in vibration control can cause instability if not properly taken into account in the controller design. The controller design is performed through the receptance method to exactly assign a pair of pole and to achieve a given stability margin for ensuring robustness to uncertainty. The desired stability margin is achieved by solving an optimization problem based on the Nyquist stability criterion. The method is applied on a laboratory testbed that mimic a typical flexible robotic system employed for pick-and-place applications. The linearization assumption about an equilibrium configuration leads to the identification of the local receptances, holding for infinitesimal displacements about it, and hence applying the proposed control design technique. Nonlinear terms, due to the finite displacements, uncertainty, disturbances, and the coarse encoder quantization, are effectively handled by embedding the robustness requirement into the design. The experimental results, and the consistence with the numerical expectations, demonstrate the method effectiveness and ease of application.

Hybrid vibro-acoustic active control method for vehicle interior sound quality under high-speed

For the problem of active noise control (ANC) and active vibration control (AVC) methods, only noise and vibration can be controlled separately. Active sound quality control (ASQC) method and AVC method are combined to carry out an in-depth study on the active control method of vehicle interior sound quality, using the vibration-sound transfer function and considering the requirements of sound quality. Combined with the adaptive noise equalizer (ANE) algorithm, a sound retention factor was introduced on the basis of the hybrid vibro-acoustic filter-u and filter-x least mean square (HVA-FUXLMS) algorithm, a hybrid vibro-acoustic adaptive noise equalizer (HVA-ANE) algorithm was proposed to control the sound quality. Based on the filter-error least mean square algorithm (FELMS) algorithm, a hybrid vibro-acoustic empirical-mode-decomposition frequency-domain block filter-error least mean square (HVA-EMDFELMS) algorithm for vehicle interior sound quality was proposed. Vibration and noise at high speeds are collected and analyzed for sound quality levels. This article used HVA-ANE and HVA-EMDFELMS algorithms to perform ASQC simulation experiments. The results showed that the noise loudness was greatly reduced while the noise and vibration control was taken into account by the HVA-ANE algorithm and HVA-EMDFELMS algorithm. Hybrid vibro-acoustic active control method for vehicle interior sound quality can effectively improve the sound quality of vehicle and can be applied to the active control of vehicle noise and related engineering noise.

Active vibration control method of double crystal monochromator of P2 protein crystallography beam line at SSRF

The angular stability of the double-crystal monochromator (DCM) directly affects the positional stability of the focused spot. This paper describes the active vibration control (AVC) method of the DCM of P2 Experimental Station at SSRF based on the adaptive filtering algorithm and the AVC system improves the performance of by optimizing the filter weight estimation algorithm. The simulation results show that the amplitude of the crystal in the pitch direction is greatly reduced by the AVC method, the RMS value of the angular displacement in the pitch direction of the crystal is 1.23 nrad, which is 91.93% lower than the passive vibration control (the RMS value of the angular displacement in the pitch direction is 15.25 nrad); the RMS value of the angular displacement in the pitch direction of the optimized AVC system is 0.233 nrad, which is 98.47% lower than that of the passive vibration control method. The AVC method can effectively ensure the angular stability of the DCM in the pitch direction, which is of great significance for the key equipment of the new generation of synchrotron radiation light source to achieve nano-radian stability.

Active vibration control for GyroWheel based on sliding mode observer and adaptive feedforward compensator

This article proposes an active vibration control method for the GyroWheel to ensure the attitude stability precision of the spacecraft. The method includes sliding mode disturbance observer and adaptive feedforward compensator. First, considering the disturbance torque caused by rotor imbalance, the dynamic equation adopting complex coefficients is derived with synchronous disturbances. To reduce the influence of model parameter perturbation, a finite time sliding mode observer is designed to estimate the rotor imbalance owing to its robustness. An integrator for the switching term is introduced in the sliding manifold, which attenuates the chattering phenomenon. Then, the observed unbalanced torque is utilized to generate the reference compensation tilting angle, which is fedforward to the command value to offset the synchronous frequency current. A variable step size seeking algorithm is adopted to tune the feedforward compensator gain adaptively. Finally, both numerical simulations and experiments have verified the effectiveness of the active vibration control scheme, achieving clean vibration torque.