Vibration Control Technique Research Articles

A Comprehensive Review Based on Analysis Modeling, Mechanical Vibration Control Strategies, and Optimization Methods of Robotics Flexible Manipulator Structures

Flexible Manipulators (FMs) provide a number of benefits, containing reduced weight due to the thinness of the robot’s linkages. Although the initial plan was to use actual robots’ flexibility or slenderness to their advantage, the complex dynamics of the systems piqued interest in using an experimental flexible manipulator as a testing ground for various modeling or control strategies. A review is essential for researchers who want to align their study objectives with those of the field because the literature is extensive and diverse. Due to the widespread usage of flexible manipulators in different mechatronic and robotic applications over the past few decades, many academics worldwide are now interested in researching this topic. Studies are categorized here according to the control and modeling technologies of flexible manipulators and methodologies. Review of recent works on analysis, modeling, mechanical vibration, control algorithms, gyroscope technology and applications, difficulties in managing flexible manipulators and their anticipated future, and the majority of the notable evolutionary and optimization algorithms, including Genetic Algorithm (GA), Differential Evolution (DE), and Fuzzy Logic (FL), as well as modification approaches and techniques, are discussed and underlined. This study examines many publications, thoroughly reviewing the analytical, mathematical, dynamical modeling, mechanical vibration control techniques and most of the notable evolutionary and optimization algorithmic approaches of Robotic Flexible Manipulator (RFM) structures.

Active nonlinear vibration control of a buckled beam based on deep reinforcement learning

Vibration control in civil engineering is often challenging due to the nonlinear nature of structures. Traditional control strategies have limitations in terms of modeling accuracy and scalability, especially when analyzing complex nonlinear systems. To solve this problem, this study proposes a model-free active vibration control technique specifically for nonlinear systems, which employs deep reinforcement learning (DRL) to train a neural network controller. The effectiveness and practicality of the proposed method have been validated on a shallow, simply supported buckled beam. The results prove that DRL can significantly increase the safety margin and effectively mitigate buckling under high load levels without requiring extra energy. Compared with conventional model-based linear and polynomial controllers, the proposed control strategy demonstrates excellent adaptability and ease of implementation. This research aims to supplement and expand the existing understanding of DRL applications in structural control, pointing towards a promising direction for future technological advancements and real-world applications.

Investigation of the robustness of a novel input preshaping vibration control technique

Abstract This work presents a study on the robustness of a novel preshaping command input method for vibration control of moving flexible structures. The methodology is based on a time-parameterised B-spline approach, with control points determined by solving a linearly constrained quadratic optimisation. The objective function minimises the vibrational energy, while the constraints set the kinematic limits of the motion control. Two case studies are considered to investigate the robustness and performance of the proposed method with respect to modelling errors: a triple pendulum on a cart and a rotating Euler-Bernoulli beam. The models are implemented in a Modelica language to simulate the virtual system response under varying operating conditions.

Comparison of active and passive vibration control techniques for electric drive power electronic subsystem: Experimental validation

Reducing vibration and noise from power electronics components is vital for enhancing the performance and acceptance of electric vehicles, emphasizing the need for effective mitigation strategies in sustainable transportation. This paper compares passive and active vibration techniques, with a specific focus on utilizing particle damping for passive vibration control. The method achieves vibration reduction through viscoelastic deformation and friction resulting from the movement and collisions of granular material within the cavity. This contribution outlines diverse design strategies for integrating particle dampers into power electronic components. The active control approach, operating typically in the 50 Hz to 1200 Hz frequency range, can concurrently support passive noise treatments. Piezoelectric ceramics serve as both actuators and sensors in active noise reduction. Following the identification of dominant mode shapes, appropriate actuator and sensor positions are chosen. The control problem of the smart system is then addressed, opting for a velocity feedback control algorithm in a real collocated design. This algorithm computes input signals for actuators bonded to the outer surface, achieving significant active damping effects. Lab-tested techniques are validated in real-world conditions with a full-scale electric-drive toolkit, affirming their efficacy in reducing vibration and noise and underscoring their potential for implementation in electric vehicles.

Vibration damping of sandwich panels using the Acoustic Black Hole effect

Among the existing passive vibration control techniques, the use of the acoustic black hole (ABH) is a solution that has the advantage of not increasing the mass of the structure in which it is integrated. In this paper, the benefits of inserting an ABH into a three-layer sandwich panel (fibreglass skins and honeycomb core) are investigated. It is known that an ABH effect can be achieved in a panel by locally reducing its stiffness (using a reduction in plate thickness according to a power law profile) and increasing local damping (using a coating of viscoelastic material). A sandwich panel induces a shear effect that strongly affect the wave propagation and lead to specific properties to the ABH effect. The equations of motion of a thick, symmetrical sandwich panel with non-uniform characteristics are obtained within the framework of zig-zag theory by applying Hamilton's principle. These equations lead to a semi-analytical model of order 6, from which an effective bending stiffness, dependent on both frequency and space can be derived. Using this model, it is demonstrated that the sandwich effective bending stiffness favours the ABH effect. This interesting property is also validated by experimental tests on sandwich panels using laser vibrometry.

Comprehensive design strategy of the NSD–TMD controlled system with closed-form frequency-amplitude solutions

A negative stiffness device (NSD) utilizing pre-compressed helical springs has been integrated with diverse vibration control techniques. Recently, the incorporation of NSD has been proposed to enhance the efficacy of a tuned mass damper (TMD) controlled system. This study introduces two design strategies for the NSD–TMD system, which functions either as a TMD with an adjustable operating bandwidth or as a pure non-linear energy sink. First, the non-linear force of NSD was expressed in a Taylor series approximation form incorporating a negative linear stiffness and a positive cubic stiffness term. Second, the equations of motion were formulated, and closed-form solutions were derived using the complexification–averaging method. The accuracy of the Taylor series approximation was substantiated within a specified range through a comparison of force–displacement curves. Third, the accuracy of the dynamic closed-form solutions was affirmed by comparing the amplitude–frequency curves with the numerical simulations. For a case study, an actual timber pedestrian bridge with decaying natural frequency was selected, and the two design strategies were examined individually. The vibration control performance of the TMD and NSD–TMD was also comparatively analyzed. The assessment focused on the peak force transmissibility value and the effective operating frequency bandwidth. Results highlighted a notable enhancement in operational performance, particularly for primary structures exhibiting diminishing modal frequencies. In a TMD-controlled system, the efficacy of vibration control deteriorates and may even amplify the dynamic response when a modal frequency shift occurs in the primary structure. Conversely, both design strategies of NSD–TMD can achieve lower transmissibility and broaden the operating bandwidth.

Research on decoupled transfer path analysis method and its application in hybrid mechanical systems

As a key technique of vibration control, transfer path analysis (TPA) provides theoretical support for diagnosis, analysis, evaluation, and optimization of vibration in mechanical systems. The coupling phenomena often exists in the vibration transfer paths of complex mechanical systems, which makes most of the existing TPA methods unable to accurately analyze the transfer function of the coupled paths. The classical transfer path analysis (CTPA) is an effective method to solve the problem of path coupling, but it changes the inherent characteristics of the system, the results can not accurately reflect the vibration transfer characteristics of the system. In order to overcome the disadvantages of CTPA method, a decoupled transfer path analysis (DTPA) method is proposed in this paper, and the implementation process of this method is introduced by taking a hybrid mechanical system as an example. The results show that DTPA method can solve the path crosstalk problem and accurately calculate the transfer function of each path.

Active vibration control for thin curved structures using dielectric elastomer actuators

This study proposes an active vibration control technique for pipe structures using dielectric elastomer actuators (DEAs). Vibrations in pipe structures must be eliminated to improve their mechanical reliability, and active vibration control techniques can be applied for effective vibration suppression. Soft actuators, which can completely fit pipe structures with complex-shaped surfaces, are required to transfer their vibration reduction forces to the target. DEA is suitable for this kind of target structure because DEA is characterized by high stretchability, flexibility, large deformation, and fast response. By applying the DEA, the effectiveness of vibration control for the pipe structure was experimentally demonstrated. A stacked DEA was fabricated and attached to the target structure. Its shape and placement were determined based on a modal analysis of the target structure. A control system, in which the controller for the active vibration control was designed based on H∞ control theory, was composed. The vibration control experiment was conducted using the controller with a digital control system, and the vibration reduction effect was evaluated based on the frequency response of the target pipe structure.

Axial Vibration Control Technique for Crystal Growth from the Melt: Analysis of Vibrational Flows’ Behavior

A problem of efficacy of crystal growth methods for crystallization from solutions or melt has been investigated. The axial vibrational control (AVC) technique was considered as a perspective method to manage both heat-mass transfer and chemical component composition of the melts in the case of crystallization of complex chemical compounds. Numerical modeling and the search for generalized dependencies made it possible to predict the AVC parameters that provide optimal heat and mass transfer modes for creating flat liquid-solid interfaces, as well as the component composition of dissociated melts of various chemical compounds—Ge, NaNO3, CdTe.

Distributed control of a plate platform by NES-cells

Nonlinear energy sink (NES) has become a good passive vibration control technique with great potential. For a huge structure, it is unpractical to control the vibration by just one NES, let alone the structure has multi-modes. In this work, a technique who uses distributed nonlinear energy sink cells (NES-cells) to control the multi-modal resonance of the floating raft is proposed. The floating raft is simplified as a corner-point supported plate. Natural modes of it guide the distribution of NES-cells to make NESs locate on the position with strong vibration, which enhances the coupling ship between the plate platform and NES-cells. An example of installing NES-cells guiding by the first-two modes of the corner-point supported plate is presented in this paper. It is compared with the vibration reduction effect by a single NES. To make a fair comparison, total mass of NES-cells is the same with that of the single NES. The results show that NES-cells can deal with multi-modal vibration reduction better. The experimental results also fully illustrate this view. At the same time, the reaction of each NES-cell to the plate is effectively dispersed while comparing with the single NES, which decreases the stress at the attachment points and is more suitable for engineering applications. The number of NES-cells also has an effect on the vibration reduction efficiency. When the design parameters are fixed, there exists an optimal number to make the vibration reduction efficiency tend toward saturation. The multimodal vibration control of the plate platform is effectively solved by the proposed NES-cells technique. It also provides guidance for other practical engineering problems.

Numerical Simulation of CdTe Crystal Growth Using the Vertical Gradient Freeze Technique Assisted by Axial Low-Frequency Oscillations of the Melt

The problem of intensification of the melt crystal growth process has been analyzed using CdTe as an actual material. Numerical simulation of 100 mm diameter CdTe crystal growth using the VGF technique has been carried out. The heat–mass transfer was controlled by introducing low-frequency oscillating baffle into the melt, which is a so-called axial vibrational control (AVC) technique. The baffle configuration has been optimized to destroy solid “tails”, which were formed near the crucible walls at high cooling rates due to the low thermoconductivity and the corresponding latent heat. Analysis of CdTe homogeneity range showed that during fast crystal cooling, Te micro precipitations were formed, resulting from the decay of oversaturated Cd-rich nonstoichiometric solid solution during the Bridgman crystal growth technique. After full crystallization, a VGF-grown CdTe crystal stays inside the phase field of the high-temperature wurtzite polymorph. This makes it possible to go through the polymorph transition without Te micro-precipitating using the advantages of the VGF-specific feature of very slow cooling.

Optimal design of stochastic aeroviscoelastic systems in subsonic regime using the doublet lattice

In a concerted effort to mitigate the global environmental impact, various governments and international organizations have put forth strategies aimed at enhancing the efficiency of products and solutions. The aeronautical and aerospace industries have set forth an ambitious target of eliminating their CO2 emissions by the year 2050. To realize this objective, manufacturers are adopting innovative approaches, including the incorporation of new blade engines, utilization of Sustainable Aviation Fuel (SAF), integration of lighter materials, and the adoption of novel geometric wing shapes designed for enhanced efficiency. However, the implementation of structural and aerodynamic modifications, such as those required for aeroelastic systems, can lead to instability effects, notably the flutter phenomenon. Addressing this challenge, one viable strategy involves the application of vibration control techniques. In this context, the use of passive control with viscoelastic materials emerges as an intriguing option due to its cost-effectiveness and ease of application. Additionally, considering the inherent variabilities in structural and aerodynamic parameters within these systems, there is a need for an efficient stochastic modeling methodology to cater to realistic applications of industrial significance. The present study endeavors to model a stochastic aeroviscoelastic system, specifically focusing on a plate-like wing in a subsonic regime. This is achieved through the integration of stochastic finite element modeling and the Doublet Lattice Method (DLM). The study aims to quantify the impact of increased mass and stiffness, particularly related to the addition of layers and the inclusion of damping from the viscoelastic material. The findings of the research demonstrate a noteworthy 31% increase in flutter speed with a corresponding 38% increase in mass. Although the ratio of speed gain to mass gain is below one in this instance, with a partial treatment approach, it can potentially reach 2. This underscores the advantageous nature of treating aeronautical panels with layers of viscoelastic material. Importantly, the engineer possesses the capability to strategically select deterministic parameters to align with specific objectives between the two defined functions.

Dynamics analysis and parameter optimization of a vibration absorber with geometrically nonlinear inerters

The inerter-based dynamic vibration absorber (DVA) is a promising technique for vibration control. In most studies, the inerter is usually mounted in the same direction as that of the motion, which may not adequately reflect the vibration suppression capability and the two-terminal inertial feature of the inerter, and even weakens the performance of vibration absorbers. Considering the potentiality of improving the control performance by unconventional mounting methods, a rarely studied structure of geometrically nonlinear inerters is introduced into the vibration absorber system. This novel vibration absorber is presented to investigate the following issues, that is, the unknown coupled dynamical behavior between the complex nonlinear force with inertia, damping, and stiffness terms generated by this structure and the vibration absorber system, the possibility of vibration absorption facilitated by this structure, and the full utilization of the two-terminal inertial feature of the inerter. The approximate solutions of the system are obtained using the harmonic balance method. The influence of each variable on the system response is analyzed, and the system parameters are optimized by using the grey wolf algorithm. In addition to the ordinary resonance phenomenon, there are also dynamic features such as soft characteristic jump behavior and response loops at certain parameter range. As a nonlinear system, this model is more stable than the nonlinear energy sink (NES). The optimized amplitude-frequency curves are equal-peak stable, similar to the linear vibration absorbers. The robustness of system parameters is high for small inerter-mass ratios or excitation amplitudes, which is better than DVAs. Compared to the classical linear vibration absorber, NES, and improved NES, the vibration suppression capacity and damping bandwidth of this model are enhanced. In comparison, it is also found that this model has smaller optimum parameters than the classical NES and equivalent inerter-enhanced DVA and NES. This model offers a new solution for the design and implementation of passive vibration absorbers with comprehensive performance.

Improving the useful life of tools using active vibration control through data-driven approaches: A systematic literature review

In the present era of sustainable smart manufacturing within the industry 4.0 framework, industries thrive to achieve sustainable development. Machining processes play a substantial role in smart manufacturing. At the same time, the cutting tool is the most significant element of any machining process. The excessive tool wear or sudden failure of the cutting tool causes unplanned downtime, and it also affects the quality of finished products, economics, and effectiveness of the process. Among all the aspects, the vibrations that occur during machining and cutting forces are the most critical parameters, which accelerates the rate of tool wear. Active Vibration Control (AVC) techniques have emerged as promising approaches for mitigating the detrimental effects of vibration on tool performance. To realise the maximum potential of AVC, however, requires a methodical and exhaustive understanding of the existing literature. This study demonstrates the significance of conducting a systematic literature review on improving the Useful Life of cutting tools employing AVC and estimating through data-driven methods. A systematic literature review on AVC and remaining useful life (RUL) estimation of a cutting tool is performed using the "Preferred Reporting Items for Systematic Reviews and Meta-Analysis" (PRISMA) methodology. However, the study primarily highlights the active vibration control through MR fluid and its characteristics, modelling, and control techniques. Moreover, the data-driven approach for the RUL prediction is discussed briefly through data acquisition, data processing, feature extraction and ranking techniques together with decision-making algorithms. This review presents a structured method for identifying, evaluating, and synthesising relevant studies, thus providing a comprehensive overview of the current state of research in the field. This review seeks to identify gaps, trends, and research directions in the application of AVC for tool longevity by analysing a wide variety of literature, including peer-reviewed journal articles, conference proceedings, and technical reports. Researchers, engineers, and practitioners engaged in tool design, maintenance, and optimization will benefit from the findings of this systematic literature review. The findings will provide a consolidated knowledge base for informed decision-making, allowing for the identification of knowledge deficits, research opportunities, and avenues for further study. The ultimate objective of this review is to contribute to the advancement of AVC techniques for extending the RUL of tools, nurturing innovation, and promoting sustainable and efficient practises across a variety of industrial sectors.

On slow-flow dynamics, stability charts, and vibration elimination of a self-excited structure utilizing a novel control technique

This work focuses on vibration elimination, bifurcation control, and stability achievement in a harmonically forced self-excited nonlinear oscillator. A novel control technique called the Integral Resonant Positive Position Feedback Controller () has been introduced in this study. The proposed controller is composed of second-order and first-order filters, integrated into the targeted oscillator in nonlinear form. Then, the averaging equations governing the slow-flow dynamics of the coupled systems are deduced. Subsequently, the relevant nonlinear algebraic system, which characterizes the static bifurcation, is obtained. The effectiveness of the controller in eliminating system vibrations, controlling nonlinear bifurcations, and stabilizing the unstable motion is investigated through bifurcation diagrams, two-dimensional stability charts, and numerical simulations of the instantaneous vibrations. The conducted analyses approved that the not only can stabilize the unstable motion of the considered system, but also it can completely eliminate the self-excited vibration regardless of the forcing magnitude and excitation frequencies. Furthermore, a comparative analysis is conducted to evaluate the control performance of the in comparison to previously utilized control techniques for vibration control in self-excited systems. The comparative results demonstrate that the exhibits superior performance in terms of vibration elimination efficiency, bifurcation control, and stability achievement. Finally, numerical validation corroborated our analytical findings, showing alignment with the analytical solution. Moreover, the simulation results demonstrated that the effectively mitigates undesired vibrations, reducing them to zero in a short transient period.

A neural state-space-based model predictive technique for effective vibration control in nano-beams

Model predictive control (MPC) is a cutting-edge control technique, but its susceptibility to inaccuracies in the model remains a challenge for embedded systems. In this study, we propose a data-driven MPC framework to address this issue and achieve robust and adaptable performance. Our framework involves systematically identifying system dynamics and learning the MPC policy through function approximations. Specifically, we introduce a system identification method based on the Deep neural network (DNN) and integrate it with MPC. The function approximation capability of DNN enables the controller to learn the nonlinear dynamics of the system then the MPC policy is established based on the identified model. Also, through an added control term the robustness and convergence of the closed-loop system are guaranteed. Then the governing equation of a non-local strain gradient (NSG) nano-beam is presented. Finally, the proposed control scheme is used for vibration suppression in the NSG nano-beam. To validate the effectiveness of our approach, the controller is applied to the unknown system, meaning that solely during the training phase of the neural state-space-based model we relied on the data extracted from the time history of the beam’s deflection. The simulation results conclusively demonstrate the remarkable performance of our proposed approach in effectively suppressing vibrations.

Application of metal rubber for semi-active vibration control of mechanical transmission systems

This study proposes a novel semi-active vibration control technique for mechanical transmission systems. The backbone of current research technology is the adaptive stiffness and damping properties of metal rubber (MR) which plays the role of tuning to the vibrational system eigenmodes. The adaptive properties of MR material were proved by a previous study, but the present research investigates the effect of this feature on the structural response and designs an MR-based semi-active vibration controller for industrial application. For this purpose, the semi-active control strategy is created based on an optimal tuning using experimental harmonic test results. The control strategy is applied in practice using a linear actuator controlled by a double pole double throw (DPDT) relay, and National Instruments hardware and software for reading data and writing the control task. The isolator attachment position is defined through the analysis of eigenmode shapes that are predetermined by numerical simulation. A maximum isolation rate of 55.17% is measured near the vibration isolator position. It is observed that the isolation position has a prominent effect on structure vibration behavior where the elastic wave has been reduced in amplitude by passing the isolator position. The effectiveness of the MR-based semi-active control approach is eminent and its application for vibration isolation of commercial mechanical transmission systems could be studied in the future.

Performance and protection of pre-engineered buildings subjected to blast and earthquake excitations

A pre-engineered building (PEB) refers to a building which is pre-designed at a factory using some simulation and modelling software as per the specifications, codes and the loads that act on the structure before the production of the building components and then finally assembled at site thereby reducing the completion time. In the current study, a case study of an existing PEB structure subjected to wind analysis has been investigated. The main objective of the present study is to evaluate the retrofitting ability of passive control dampers installed in the pre-engineered industrial building subjected to earthquake and blast phenomenon. The study investigates the effectiveness of vibration control techniques in the form of passive dampers in improving the performance of PEB structure subjected to blast and earthquake using fluid viscous dampers. The study also discusses the impact of different damper placement techniques on the structural performance of PEB structure subjected to blast and earthquake loading. Primarily three damper placement techniques are incorporated in the present study, namely single diagonal, V-shaped damper, and inverted V-shaped damper. The study also evaluates the optimum fluid damper properties, namely damping coefficient and damping exponent, in mitigating the blast and earthquake responses of the selected industrial building. The structural performance of PEB structure has been studied using finite element tool considering the nonlinear analysis and comparing the structural responses for with and without damper conditions. The V-shaped and inverted V-shaped damper placement techniques are the most effective approach in resisting the damaging effects against blasts and earthquakes for the selected PEB structure in comparison with the conventional diagonal braced dampers. The study reports reductions in structural displacements and brace forces in the range of 54–68% and 70–90%, respectively, when installed with V-shaped fluid viscous damper.

The exact spectral element modeling and vibration analysis of the acoustic black hole double-beam system

In this paper, we present a study of vibration characteristics of the double-beam structures combined with the concept of the acoustic black hole (ABH), which is an effective technique for vibration and noise control. In the proposed double-beam structure, the ABH beam as the vibration damper is attached to the primary uniform beam by a range of translational and rotational springs. We formulate the closed-form spectral element matrix of the double-beam structure and calculate the natural frequencies and mode shapes of the system. The results demonstrate the ABH effect of increasing the modal damping ratios. We also study the power flow and mechanical intensity of the system to offer physical insight into the vibration suppression mechanism of the ABH. A detailed parametric analysis of both translational and rotational springs is carried out. The investigation contributes to the exact dynamic modelling and analysis of the double-beam system containing ABH elements. Furthermore, the proposed ABH double-beam structure shows great potential for vibration control and energy harvesting.

Vibration Control of a Dynamic Structure Using PLZT Sensor and Actuator with Temperature Variation

Piezoelectric material PLZT exhibits non-linearity in the dielectric constant and piezoelectric strain coefficient with respect to the temperature. In this paper, the active vibration control technique is employed on a cantilevered plate structure using PLZT piezoelectric material as a sensor as well as an actuator. The variation in dielectric constant and piezoelectric strain coefficient with change in temperature is considered while actively controlling the vibrations of the plate instrumented with PLZT patches. The finite element modeling of the structure is done using Hamilton’s principle. The modified constitutive equations of piezoelectric material PLZT are included for dielectric constant and piezoelectric strain coefficient with respect to the temperature variation. The vibrations are sensed by one piezoelectric patch at different ambient temperatures ranging from 27 °C to −15 °C. The negative velocity feedback control law is used for the active vibration control of the structure. The second piezoelectric patch is used as an actuator in the same temperature range of 27 °C to −15 °C. The experiments are performed for two cases: in case 1 the effect of temperature on dielectric constant and piezoelectric strain coefficient is ignored in the control law for active vibration control of the structure. In case 2 the effect of temperature on dielectric constant and piezoelectric strain coefficient is considered in the control law. In this work, the active vibration control of a dynamic structure is achieved by using PLZT piezoelectric material with the variation in ambient temperature.