Vibration Suppression Method Research Articles

Active vibration suppression at bearing pedestals in an elastically supported shafting system via non-contact electromagnetic actuators

The bearings are important paths for the shaft vibration transmitting to the hull structure. A new scenario based on non-contact electromagnetic actuators mounted at bearing pedestals is proposed to suppress the vibration transmission from the shaft to the elastic foundation. The dynamic model of a shafting system with the non-contact electromagnetic actuators is established on the Hamilton’s principle. With this model, the influence of the displacement stiffnesses of the electromagnetic actuators on the vibration transmission is discussed, and the feasibility of active control is investigated. A multi-harmonic vibration suppression method is adopted and the performance is evaluated. Numerical results show that the vertical control by the electromagnetic actuators is able to attenuate the vibration transmission from the shaft to the foundation. With the addition of horizontal control, the foundation vibration is further decreased due to the reduction of power flow generated by the moments between the bearing pedestals and foundation. The results of a proof-of-principle experiment have also verified the effectiveness of the vertical control by the non-contact electromagnetic actuators in vibration transmission suppression and the foundation acceleration responses are remarkably reduced.

Research on Unbalanced Vibration Suppression Method for Coupled Cantilever Dual-Rotor System

The cantilever dual-rotor system is a typical structure of the blade output end of the open rotor engine and the coaxial output turboshaft engine. The excessive unbalanced vibration of a coupled cantilever dual-rotor system is one of the main factors limiting the application of the above engine type. In order to accurately describe the vibration coupling effect between the dual-rotor-intermediate bearings, the unbalanced response of the cantilever dual-rotor system is analyzed, and the self-sensitivity coefficient is proposed to guide the selection of measuring points and vibration suppression experiments for the dual-rotor system. On this basis, a new online automatic balance actuator applicable to this dual-rotor system is designed, and a feasibility experiment is carried out. The experimental results indicate that: (1) The self-sensitivity coefficient can be used as the basis for the actual vibration measuring point arrangement and unbalanced vibration suppression strategy of the dual-rotor system, and the proposed step-by-step vibration suppression strategy can reduce the vibration of the dual-rotor system by more than 80%. (2) The designed online automatic balance actuator can reduce the unbalanced vibration by 53% in 3.52 s. The proposed method in this study can provide guidance for the vibration suppression of the dual-rotor system.

Online Control Strategy for Radial Vibration Suppression of PMSM by Multiharmonic Current Injection Method

In the radial vibration suppression of the motor, the current harmonic injection method is an effective method. The radial force model of surface permanent magnet synchronous machine (SPMSM) is analyzed, and the relationship of the frequency, amplitude and phase between harmonic current and radial vibration harmonic is obtained. A current harmonic injection method is derived by using the current closed-loop transfer function in vector control, which can adjust the frequency, amplitude and phase of current harmonics to realize the change in the amplitude of radial vibration harmonics. one current harmonic is selected to suppress one even-order radial vibration harmonic, and the gradient descent method is adopted to online calculate the frequency amplitude and phase of the current harmonics injected at the minimum amplitude of radial vibration harmonics. In order to avoid the influence of the single current harmonic on the high radial vibration harmonics, a sequential vibration suppression method is proposed to realize the comprehensive suppression of every low-even-order vibration harmonics. Finally, an on-line control system for the radial vibration suppression of SPMSM with multi-current harmonics injection is designed. The prototype is a 750W SPMSM, the amplitude of all low-even radial vibration harmonics are suppressed significantly by this method, which verifies the correctness and effectiveness of this method.

Zeroth-Mode Vibration Suppression Through Adjustment on Phases Difference of Concentrated Force Harmonics for PMSMs

Zeroth-mode vibration is the dominant noise source in permanent magnet synchronous machines (PMSMs). In conventional approaches, the zeroth-mode vibration is reduced by lowering the amplitudes of concentrated forces. Different from conventional approaches, this article proposes a zeroth-mode vibration suppression method through adjustment on phase difference of concentrated forces. First, the characteristics of concentrated forces are analyzed considering the effect of slotted structure on air-gap electromagnetic force wave (EMFW), and the relationship between phase difference of concentrated force harmonics (CFHs) and the mode of vibration is obtained. Subsequently, the effects of both permanent magnet (PM) and harmonic currents on air-gap EMFW are analyzed. It is found that the phase differences of CFHs can be adjusted by combining PM shape optimization and harmonic current injection. Finally, a 12-pole 36-slot PMSM and a 16-pole 48-slot PMSM are carried out to calculate the concentrated forces and vibrations by finite element method (FEM). It is proven that the proposed method can adjust the phase difference from zero to two tooth pitches, and the zeroth-mode vibration is significantly suppressed.

Forced vibration mechanism and suppression method for thin-walled workpiece milling

Thin-walled workpieces are widely used in aerospace applications, but their weak stiffness characteristic leads to forced vibration during milling, which reduces the quality of the milled surface. To solve the forced vibration problem in milling thin-walled workpieces, this paper proposes a forced vibration mechanism for the thin-walled workpiece under the influence of various factors and a corresponding suppression method. First, the response characteristics of the thin-walled workpiece excitation features correlated with the mode shape are given. Then, the vibration shapes of the thin-walled workpiece are combined with the cutting position, and the effects of the cutting force frequency and cutting force magnitude are also considered. Finally, the different vibration characteristics are associated with the time constant properties of the shear thickening fluid (STF), and the corresponding forced vibration effects are suppressed by the STF. After a series of experimental modal analyses and cutting experiments, the results show that the proposed theory can explain the forced vibration phenomenon of the thin-walled workpiece, and the vibration suppression effect of the STF is consistent with the theory. The method is also applicable to vibration suppression at the weak position during the machining of the large workpiece.

Simultaneous Suppression of Translational and Tilt Vibrations in a Superconducting Magnetic Levitation System by a Gyroscopic Damper

In this paper, suppression effect of a gyroscopic damper on vibrations of a body levitated by magnetic force acting from superconductors is investigated by numerical calculations. Because of the low damping property of the superconducting magnetic levitation system, simultaneous suppression of multi-degree-of-freedom vibration due to the coupled translational and tilting motions of the levitating body and suppression of nonlinear vibration are important development issues. A gyroscopic damper has been considered as a passive vibration suppression method that takes advantage of the control-free features of superconducting magnetic levitation systems, and if the design parameters are optimized, it may be possible to simultaneously suppress not only tilt vibration but also translational vibration. In this paper, the governing equations are first derived from the analytical model, and then numerical calculations are performed. As a result, the simultaneous suppression effect of the gyroscopic damper on the translational and tilt vibrations of the levitating body was numerically confirmed. Furthermore, the suppression effect of the gyroscopic damper on the nonlinear vibration of the levitating body was also confirmed numerically.

Position phase-based vibration suppression method for rotating flexible disk system with parametric excitations

A novel vibration control method for the rotating flexible disk system under parametric excitations, named position phase-based vibration suppression method, is proposed theoretically in this paper. This method can achieve vibration suppression efficiently by applying external parametric excitation to the rotating flexible disk and adjusting its position phase angle. The dynamical modeling of the disk with stressless initial deformation is established considering time-varying speed, symmetrical mass-spring-damper loading system and nonlinear electromagnetic attraction. Two vibration evaluation indexes are proposed for verifying the suppression effect of this method, one represents the deviation of the disk from its ideal position and the other represents the vibration's intensity. The steady-state response of the disk system with different parametric excitations’ phases is calculated and the phases region that can be used for vibration suppression is determined. Theoretical results show that the exerting of slider loading and electromagnetic attraction with suitable position phases can effectively suppress the transverse vibration of the flexible disk, whether the rotating speed is constant or fluctuant. Meanwhile, the combined effect of these two parametric excitations can better suppress the disk's vibration under the premise that the disk system is stable.

Transonic flutter suppression with tuned mass damper by model-based stability analysis method

Flutter as a self-excited oscillation can cause catastrophic damage to the aircraft structure. Tuned mass damper (TMD) is one of the vibration suppression methods widely used in engineering. However, traditional linear aerodynamic methods are not accurate in transonic flow. In this study, we first establish an unsteady aerodynamic model of the NACA0012 airfoil using the system identification method based on the Auto-Regressive with eXogenous input (ARX) model. Then, a flutter suppression model is constructed by coupling the TMD with the aeroelastic system. The parameters of the TMD are investigated using the model-based aeroelastic stability analysis. It is found that the flutter instability mode of the original system has changed due to the participation of the TMD in the system modal coupling. The proposed reduced-order model (ROM) provides a fast stability analysis method for flutter suppression with TMD as well as significant guidance for TMD design and optimization.

Thermal Analysis and Rigid-Flexible Coupling Dynamics of a Satellite with Membrane Antenna

In this paper, the thermal analysis of a membrane antenna structure is performed, and then, the rigid-flexible coupling dynamic modeling and control of the membrane-antenna-satellite system are studied with the thermal stress considered. The thermal analysis model of the membrane antenna structure is derived based on the finite element method by discretizing the structure into 1D and 2D thermal elements. Considering the thermal stress, the vibration modes of the membrane antenna structure are obtained, and the rigid-flexible coupling dynamic model of the membrane-antenna-satellite system is derived based on the hybrid coordinate method. To reduce the vibration of the membrane antenna structure caused by the attitude maneuver, the control command is designed based on the component synthesis vibration suppression (CSVS) method. Simulation results show that the dynamic properties of the membrane antenna structure are affected significantly by the space thermal environment, the vibration of the membrane antenna structure can be suppressed effectively by the presented CSVS controller, and the accuracy of the attitude maneuver will be improved significantly by the proposed control strategy.

Numerical study of the vibration suppression effect of a new vibration suppression method based on a shielding wall

A deep underground laboratory is an important research site for fields such as particle physics, astrophysics and cosmology, which require not only sophisticated technology and precision instruments but also stable and interference-free research environments. Ground motion can introduce interference with some precision instruments, causing the instruments to fail to work normally with the highest accuracy and even causing serious errors. Therefore, effective vibration suppression measures play a vital role in underground laboratory research. Based on the shielding effect underground structures have on ground motions, a shielding wall is proposed as a new vibration suppression method. By simulating the ground motion characteristics of various models (background models, excavation models, and backfill models) in the Jinping Underground Laboratory, the high-efficiency vibration suppression effect of a shielding wall was demonstrated. The influence of different backfill conditions on the vibration suppression effect of the shielding wall was systematically analysed, and a nonbackfilled shielding wall was determined to be the best vibration suppression option. Moreover, the influence of the length, position and angle of the shielding wall on its vibration suppression effect and the potential application prospects of the shielding wall were also discussed. Shielding walls enrich and develop vibration suppression measures, providing a new method for the prevention and control of seismic hazards in underground laboratories and surface buildings under dynamic load conditions.

A deep reinforcement learning-based optimization method for vibration suppression of articulated robots

To solve the vibration problem of articulated robots, a deep reinforcement learning-based optimization method for input shaping (RLIS) is proposed. The optimization method applies the arbitrary time-delay filter as the model and includes two main stages: determining the RLIS initial parameter ranges; and constructing and improving the RLIS optimization strategy. In the first stage, a post-adaptive method based on the recursive least squares algorithm is used to determine the RLIS initial parameter ranges. In the second stage, the input shaping optimization problem is modelled as a Markov decision process, and the RLIS optimization strategy is constructed using a deep reinforcement learning algorithm. Subsequently, a selection mechanism based on state value and a fuzzy reward system is proposed to increase the learning efficiency and simplify the design process. Finally, several groups of experiments are designed to demonstrate the effectiveness and stableness of the proposed method in residual vibration suppression.

Vibration Suppression Method Based on PI Fuzzy Controller Containing Disturbance Observe for Dual-flexible Manipulator with an Axially Translating Arm

Vibration Suppression Method Based on PI Fuzzy Controller Containing Disturbance Observe for Dual-flexible Manipulator with an Axially Translating Arm

Design and test of adaptive torsional vibration suppression method for helicopter power system with variable rotor speed

In order to solve the problem of torsional vibration instability of the control system for turboshaft engine caused by low-order torsional vibration modal drift under variable rotor speed effectively, an adaptive torsional vibration suppression method based on the least mean square algorithm is proposed and designed. First, based on Lagrange equation and state space method, the structural dynamic model of torque transmission chain system is established, which takes into account fixed and variable gear ratio. It is beneficial to express the dynamic characteristics of torsional vibration in real time, so that the variation laws of low-order torsional vibration modal under variable rotor speed and gear ratio are revealed. Then, an adaptive torsional vibration filter based on least mean square algorithm is proposed and designed combined with the active control objective of helicopter power system. Finally, the effectiveness of adaptive torsional vibration suppression method is validated based on numerical simulation and hardware-in-loop simulation separately. The results show that compared with the conventional constant-coefficient notch filter, the adaptive torsional vibration filter can decrease the peaks of all low-order torsional vibration frequency by more than 50%. It proves better robustness, more remarkable effectiveness and superior adaptive ability of the adaptive torsional vibration suppression method.

Hydrodynamic Performance and Vibration and Noise of Machine-pump Integration Device

As a new type of drainage equipment or underwater propeller, the machine pump integrated device composed of permanent magnet motor and pump blade of Halbach structure has many advantages and wide application prospects. Starting from the hydrodynamic analysis method of the machine pump integrated device, this paper reviews the research progress in this field at home and abroad in recent years. The results are summarized and analyzed. Finally, according to the current problem needs and the shortcomings of the research status, some ideas are put forward for the vibration and noise suppression method of the machine pump integrated device, which provides a reference for the follow-up related research.

Reduced-Order Extended State Observer-Based Sliding Mode Control for All-Clamped Plate Using an Inertial Actuator

Considering the problems of total disturbances, i.e., higher harmonics, model uncertainties and external excitations in a practical vibration control system, a compound vibration suppression method is proposed for an all-clamped plate, which combines sliding mode control (SMC) with reduced-order extended state observer (RESO). First, a state space model of the all-clamped plate with inertial actuator is established. Second, a RESO is designed to estimate the system state variables and total disturbances in real time. In addition, the total disturbances can further be attenuated by RESO through a feedforward compensation part. Third, a sliding mode controller based on the estimation values is designed for a vibration control system. The Lyapunov stability theorem is further applied to prove the stability of the whole closed-loop vibration control system with the proposed controller. Finally, vibration control experiment equipment is built based on the NI-PCIe acquisition card, inertial actuator and acceleration sensor to verify the vibration suppression performances of the proposed method. The experimental results show that the amplitude value of vibration has been reduced by 75.2% with the proposed method, while the amplitude value is reduced by 54.5% with the traditional sliding mode control method based on an extended state observer (SMC-ESO). The comparative experimental results illustrate that the proposed method has excellent anti-disturbance and vibration suppression performances.

Torsional Vibration Suppression in Railway Traction Drives

Torsional vibrations phenomena are self-excited vibrations that occur in the wheelset of railway powertrains due to the counter-phase oscillation of both wheels. Long-lasting events of this type may lead to the catastrophic failures. Therefore, torsional vibration suppression and mitigation methods have drawn significant attention from the railway industry in the recent few years. Conventional vibration suppression methods reduce motor torque once the oscillation is detected. However, this can result in trip delays. Design of methods which do not compromise the traction capability is challenging. This paper proposes a novel torsional vibration suppression method using a Proportional-Resonant (PR) controller. The proposed method is insensitive to mechanical drive-train parameter variation neither requires adding new sensors to the wheelset. The method requires previous knowledge of the natural frequency of the wheelset torsional mode but this significantly reduces the implementation complexity suffered by other anti-vibration methods. Furthermore, the method will be shown to provide reduced sensitivity to slip velocities and wheel-rail conditions.

Vibration and noise suppression method of transformer

Aiming at the problem of noise and vibration of distribution transformer body and base connector under heavy load, the corresponding relationship between vibration and noise, load and power factor of distribution transformer is studied in this paper. In order to improve the operation reliability of distribution transformer, a noise and vibration suppression method based on load scenario optimization is proposed. From the aspects of design reliability, data detection and noise level correction, the typical relationship between the increase of noise level and DC current, noise spectrum and DC bias noise is obtained, and the DC bias limiting measures and correction suggestions are given.

Spindle vibration mitigation utilizing additively manufactured auxetic materials

This paper presents novel spindle holders fabricated by using auxetic materials for spindle vibration mitigation. Unlike traditional spindle vibration suppression methods using anti-vibration tool holders or software-based dampers, auxetic material-based spindle holders enhance energy absorption and vibration damping under cyclic loading, providing sufficient stiffness and compactness. The re-entrant hexagon type auxetic structures commonly used in auxetic design were fabricated by various additive manufacturing (AM) processes such as fused deposition modeling (FDM) using carbon fiber-reinforced polymer (CFRP), powder bed fusion process (PBF) using titanium (Ti). Static and dynamic behaviors of two auxetic materials (CFRP Auxetic, Ti Auxetic) were characterized by finite element analysis (FEA), and were experimentally identified by characterizing stiffness, damping, frequency response function, vibration power transmissibility, vibration spectrum and power spectral density, and those results were compared with those of the control group to quantitatively characterize how auxetic materials impact on spindle vibration mitigation and improve spindle operations. As a result, the auxetic material-based spindle holders have high damping characteristics and showed a decrease in the spindle vibration magnitude compared to the control group. Also, it was confirmed that the auxetic material-based spindle holder can effectively suppress the spindle vibration when the spindle is idling or machining, as an alternative vibration damper. The development of the AM processes toward high part accuracy will enable further development of auxetic structures for spindle vibration mitigation.

Vibration control of a rotating Timoshenko beam-tendon system via internal guiding inerter-dampers

A guided active tendon concept is proposed to modify the dynamics of the main rotor blades to enable the rotorcraft to operate in the wider range of working conditions. Because some blade modes are not sensitive to the applied axial force, in this paper, a new vibration suppression method for a rotating Timoshenko beam axially loaded by a tendon with the inerter-damper guiding elements is proposed and studied. The equations of motion are derived by means of the Lagrange's equation with the use of the energy expressions, and the modal and harmonic analyses are carried out. The analytical model is verified and compared with an independently formulated finite element model. It is found that inerter-dampers introduce non-local modes. To tune the chosen beam-dominated modes using inerter-dampers without introducing the additional resonances, the new optimal tuning strategy is proposed. When one inerter-damper is used, the inertance and damping coefficient for the optimal tuning of the higher modes are lower than those for the lower modes. When the inerter-damper is used to tune a single mode optimally, its function is analogous to a viscous damper for the lower modes, but it is similar to a rigid attachment for the higher modes. The maximum attainable damping ratio tends to decrease with the reduction of the applied axial force and increase of the rotational speed. The optimal performance of the single inerter-damper at different locations varies. For example, it is found that the damping ratio of the second beam-dominated mode reaches the maximum value with the inerter-damper located between 0.5-0.6L from the fixed end, where the required inertance and damping coefficient for the optimal tuning reach the minimum. More inerter-dampers can be used to tune a larger number of the beam-dominated modes optimally and simultaneously. The inerter-dampers are shown to effectively suppress the beam-dominated modes in wide axial force and speed ranges. In addition, inerter-dampers can be used to support the same function as the rigid tendon-guiding attachments of increasing the frequencies of the tendon-dominated modes. However, they cannot alter the critical compressive force. By integrating inerter-dampers into the tendon-loaded blades internally, the modes insensitive to the applied axial force can be suppressed to mitigate resonant vibrations.

A thermal stress stiffening method for vibration suppression of rotating flexible disk with mass-spring-damper system loaded

A thermal stress stiffening method for the vibration suppression of a rotating flexible disk with initial transverse runout is investigated via theoretical and experimental methods in this paper. This method generates in-plane thermal stress by heating the disk inner boundary, thereby enhancing the transversal bending stiffness of the disk and suppressing the transverse vibration. The thermal stress stiffening's influence on the natural frequency, dynamic stability and steady-state response of the disk with and without a mass-spring-damper system loaded is analyzed by theoretical computation. Via a finite element method software, it is found that thermal expansion could change the non-flat disk's shape. A specialized testing set is designed, and the content of the theoretical analysis is tested through experiments. The experimental results show that this method is not only suitable for a freely rotating disk, but also for the vibration suppression of a flexible disk loaded with a transversely symmetrical mass-spring-damper system, and even for that of a flexible disk loaded with a single-sided one. Moreover, this method is easy-to-use and cost-effective in practical applications as a simple and effective way for the vibration suppression of rotating disks.