Showing papers on "Active vibration control published in 2014"
TL;DR: Together with its capability in monitoring the vibration frequency, the CF-TENG appears as the triboelectrification-based active sensor that can give full quantitative information about a vibration.
Abstract: A vibration sensor is usually designed to measure the vibration frequency but disregard the vibration amplitude, which is rather challenging to be quantified due to the requirement of linear response. Here, we show the application of triboelectric nanogenerator (TENG) as a self-powered tool for quantitative measurement of vibration amplitude based on an operation mode, the contact-mode freestanding triboelectric nanogenerator (CF-TENG). In this mode, the triboelectrically charged resonator can be agitated to vibrate between two stacked stationary electrodes. Under the working principle with a constant capacitance between two electrodes, the amplitudes of the electric signals are proportional to the vibration amplitude of the resonator (provided that the resonator plate is charged to saturation), which has been illuminated both theoretically and experimentally. Together with its capability in monitoring the vibration frequency, the CF-TENG appears as the triboelectrification-based active sensor that can gi...
199 citations
TL;DR: In this paper, an isolation platform with n-layer scissor-like truss structure is investigated to explore novel design of passive/semi-active/active vibration control/isolation systems and to exploit potential nonlinear benefits in vibration suppression.
146 citations
TL;DR: Considering the variety of uncertainties and disturbances in real active vibration control systems, a novel piezoelectric multimode control strategy for an all-clamped stiffened plate (ACSP) structure is proposed in this paper.
Abstract: Considering the variety of uncertainties and disturbances in real active vibration control systems, a novel piezoelectric multimode control strategy for an all-clamped stiffened plate (ACSP) structure is proposed in this paper. First, an active disturbance rejection control (ADRC) method, i.e., the extended state observer (ESO)-based vibration control scheme, is employed to ensure the performance of the vibration suppression and rejection of the lumped disturbances of the closed-loop system. Second, a proportional differential controller and an acceleration feedforward controller produce the control law for each vibration mode. Moreover, a chaos optimization method based on a logistic map is introduced to automatically tune the parameters of the feedback channel. The stability and superiority of the proposed controller are theoretically analyzed. Compared with the classical ADRC method, the multimode vibration experimental results demonstrate that the control performance of the first mode is improved from 12.04 to 14.06 dB; meanwhile, the performance of the second mode is also improved, having changed from 11.1 to 13.68 dB.
104 citations
TL;DR: Experimental and simulation results demonstrate that the finite element based predictive controller provides improved active vibration suppression in comparison with using a standard predictive control strategy.
Abstract: This paper presents a unique approach for active vibration control of a one-link flexible manipulator. The method combines a finite element model of the manipulator and an advanced model predictive controller to suppress vibration at its tip. This hybrid methodology improves significantly over the standard application of a predictive controller for vibration control. The finite element model used in place of standard modelling in the control algorithm provides a more accurate prediction of dynamic behavior, resulting in enhanced control. Closed loop control experiments were performed using the flexible manipulator, instrumented with strain gauges and piezoelectric actuators. In all instances, experimental and simulation results demonstrate that the finite element based predictive controller provides improved active vibration suppression in comparison with using a standard predictive control strategy.
75 citations
TL;DR: An up-to-date review of stick-slip vibration behavior in drillstrings is provided, grouping the references under the categories of passive vibration control and active vibration control.
Abstract: Stick-slip vibration presents one of the main problems in the quality of drilling performance limiting tool life and productivity. This type of vibration can be suppressed by means of many approaches, such as varying parameters and use of control tools. Although tremendous improvements have been made in overcoming this dysfunction, stick-slip vibration suppression remains a large problem in the drilling industry. This paper provides an up-to-date review of stick-slip vibration behavior in drillstrings. First, the phenomena and the modeling methods of stick-slip vibrations are reviewed. Then an overview of the approaches for stick-slip suppression in oilwell drillstrings is presented, grouping the references under the categories of passive vibration control and active vibration control. Literature related to passive control is grouped under the categories of optimization of bottom hole assembly (BHA) configurations, bit selection and bit redesign, and use of downhole tools. The contributions related to the...
67 citations
TL;DR: In this paper, the stability of the active vibration control system for both the linear and nonlinear structures was analyzed using a two-story building prototype, and sufficient conditions for choosing the PID gains were given.
64 citations
TL;DR: In this article, a flexible beam with piezoelectric pieces on the surface is investigated experimentally using the independent modal space control method, which is able to control the first three modes of the beam independently.
62 citations
TL;DR: In this article, the active vibration control of lattice sandwich beams with pyramidal lattice core is investigated and the velocity feedback control method and a linear quadratic regulator (LQR) are used to design the controllers and actively suppress the vibration of the structural system.
Abstract: Until now, few literatures on the active vibration control of lattice sandwich structures employing the piezoelectric materials have been published. Motivated from this, the active vibration control of sandwich beams with pyramidal lattice core is investigated in this paper. The piezoelectric materials are bonded on the top and bottom surfaces of the beam to act as the actuator and sensor. In the structural modeling, the discrete lattice truss core is converted to an equivalent homogenized continuum material. Hamilton’s principle with the assumed mode method is used to develop the dynamical model of the structural systems. By using the standard eigenvalue methodology, the natural frequencies are obtained. The velocity feedback control method and a linear quadratic regulator (LQR) are used to design the controllers and actively suppress the vibration of the structural system. Frequency and time domain responses are computed to analyze the control effects on the sandwich beam with pyramidal lattice truss core. It is observed from the numerical simulation that the velocity feedback control and the LQR control methods both can effectively suppress the vibration of the lattice sandwich beam.
59 citations
Patent•
09 Jul 2014
TL;DR: In this paper, integrated modules for synchronized array of Vibration Actuators (SAVA) are presented, which provide physical interface, power and communication interfaces, and can be precisely attached and aligned to the module housing, a microcontroller or other microprocessor.
Abstract: The disclosure relates to integrated modules for Synchronized Array of Vibration Actuators (FIG. 125 A). The modules provide physical interface, power and communication interfaces. Each module may include vibration actuators (FIG. 123 A) which can be precisely attached and aligned to the module housing, a microcontroller or other microprocessor, and one or more sensors for closed loop control of actuators (FIG. 126 G). Interleaved pairs of ERMs having a center of mass in the same plane eliminate parasitic torque. A single module can produce a vibration force that rotates at a specific frequency and magnitude, which on its own could cancel out some types of periodic vibrations (FIG. 125 B). Two modules paired together and counter-rotating with respect to each other can produce a directional vibration at a specific frequency and magnitude, which could prove even more useful for canceling out a vibration. Such modules are also employed to produce beating patterns (FIGS. 131 - 133 ). Both amplitude and frequency of the beating force are variable.
57 citations
TL;DR: In this paper, the authors presented a new performance index for active vibration control of three-dimensional structures, where a building is modeled as a structure composed of members connected by a rigid floor diaphragm such that it has three degrees of freedom at each floor, i.e., lateral displacements in two perpendicular directions and a rotation with respect to a vertical axis.
45 citations
TL;DR: In this article, a magnetoelectric transducer was used to extract the ambient vibration energy from a circular cross-section cantilever rod, where the magnetic interactions between the magnets and the transducers will lead to the nonlinear oscillation of the rod with increased frequency bandwidth.
Abstract: This paper presents a design for a novel vibration energy harvester using a magnetoelectric (ME) transducer, which is efficiently applicable in two-dimensional (2D) motion and over a range of vibration frequencies. This harvester adopts a circular cross-section cantilever rod to extract the ambient vibration energy because of its ability to host accelerations in arbitrary motion directions. Moreover, the magnetic interactions between the magnets and the ME transducer will lead to the nonlinear oscillation of the rod with increased frequency bandwidth. The influences of the nonlinear vibration factor and magnetic field distribution on the electrical output and bandwidth of the harvester are investigated to achieve optimal vibration energy harvesting performances. The experimental results showed that, the harvester was sensitive to the vibration with arbitrary in-plane directions. With an acceleration of 0.6 g (where g = 9.8 ms−2), it had the working bandwidths of 4.2 Hz, 2.6 Hz, 2.3 Hz, 2.5 Hz and 3.2 Hz, and the output powers of 0.6 mW, 0.49 mW, 0.33 mW, 0.5 mW and 0.56 mW at the in-plane excitation angles of−90°, −45°, 0°, 45° and 90°, respectively.
TL;DR: In this paper, an active vibration absorption scheme is proposed to extend the vibrating energy dissipation capability of a passive dynamic vibration absorber for multiple excitation frequencies and, simultaneously, to perform reference position trajectory tracking tasks planned for the nonlinear primary system.
TL;DR: In this paper, a vibration isolation system is proposed to attenuate the disturbances caused by the reaction wheel (RW), which is commonly used as an actuator for attitude control on space telescopes.
TL;DR: In this paper, the authors describe the design, manufacturing and testing of a smart rotor support with shape memory alloy metal rubber elements, able to provide variable stiffness and damping characteristics with temperature, motion amplitude and excitation frequency.
Abstract: The work describes the design, manufacturing and testing of a smart rotor support with shape memory alloy metal rubber (SMA-MR) elements, able to provide variable stiffness and damping characteristics with temperature, motion amplitude and excitation frequency. Differences in damping behavior and nonlinear stiffness between SMA-MR and more traditional metal rubber supports are discussed. The mechanical performance shown by the prototype demonstrates the feasibility of using the SMA-MR concept for active vibration control in rotordynamics, in particular at high temperatures and large amplitude vibrations.
TL;DR: In this article, the topology optimization of the piezoelectric actuator and sensor layers in a plate for achieving the best vibration control performance has been investigated, where the actuator patches and sensors layers were optimized.
Abstract: This article investigates topology optimization of the piezoelectric actuator and sensor layers in a plate for achieving the best vibration control performance. Therein, the actuator patches and se...
TL;DR: A compact stable active low frequency vibration isolation system used to process and feedback the vibration measured by a seismometer and proved the performance by adding an additional seismometer as well as applying it in the atom interferometry experiment.
Abstract: Vibration isolation at low frequency is important for some precision measurement experiments that use atom interferometry. To decrease the vibrational noise caused by the reflecting mirror of Raman beams in atom interferometry, we designed and demonstrated a compact stable active low frequency vibration isolation system. In this system, a digital control subsystem is used to process and feedback the vibration measured by a seismometer. A voice coil actuator is used to control and cancel the motion of a commercial passive vibration isolation platform. With the help of field programmable gate array-based control subsystem, the vibration isolation system performed flexibly and accurately. When the feedback is on, the intrinsic resonance frequency of the system will change from 0.8 Hz to about 0.015 Hz. The vertical vibration (0.01-10 Hz) measured by the in-loop seismometer is reduced by an additional factor of up to 500 on the basis of a passive vibration isolation platform, and we have proved the performance by adding an additional seismometer as well as applying it in the atom interferometry experiment. (c) 2014 AIP Publishing LLC.
TL;DR: In this paper, an active vibration control of a free-edge rectangular sandwich plate is proposed and tested using Positive Position Feedback (PPF) technique and is successfully applied with different combinations of inputs/outputs (Single Input Single Output, MultiSISO, Multi Input Multi Output) in order to control the first four normal modes.
TL;DR: In this paper, the utility of a bistable attachment for attenuating vibrations, especially in terms of the high-orbit, snap-through dynamic, is investigated using the harmonic balance method and experiments.
Abstract: One approach to vibration control is to apply a force to a primary structure that opposes the excitation, effectively canceling the external disturbance. A familiar passive example of this approach is the linear-tuned mass absorber. In this spirit, the utility of a bistable attachment for attenuating vibrations, especially in terms of the high-orbit, snap-through dynamic, is investigated using the harmonic balance method and experiments. Analyses demonstrate the fundamental harmonic snap-through dynamic, having commensurate frequency with the single-frequency harmonic excitation, may generate adverse constructive forces that substantially reinforce the applied excitation, primarily at lower frequencies. However, both analyses and experiments indicate that such high-orbit dynamics may be largely destabilized by increased bistable attachment damping. Destructive forces, which substantially oppose the excitation, are unique in that they lead to a form of vibration attenuation analogous to strictly adding damping to the host structure, leaving its spectral characteristics largely unaltered. The experiments verify the analytical findings and also uncover nonlinear dynamics not predicted by the analysis, which render similar attenuation effects.
TL;DR: In this article, a finite volume (FV) formulation for the free vibration analysis and active vibration control of the smart beams with piezoelectric sensors and actuators is presented.
TL;DR: In this paper, the authors exploit the measurements of fiber bragg grating (FBG) sensors as feedback for active vibration control applications, where the advantages of this solution are the possibility of monitoring a large number of sensors and embedding them in carbon fiber structures with negligible load effects.
TL;DR: In this article, the influence of external electrorheological dampers on the dynamic behavior of composite laminated plates has been investigated and several numerical results are presented and effects of imperative parameters such as applied voltage, controlled electric field, radius and initial gap of the electrodes, position of the ER damper and stacking sequences of the composite plate have considerable effect on the vibration suppression time of the plate.
TL;DR: In this paper, the active vibration control and configurational optimization of a cylindrical shell are analyzed by using piezoelectric transducers, and the optimization procedure is designed based on desired controllability and observability of each contributed and undesired mode, in order to limit spillover effects, the residual modes are taken into consideration.
01 Jan 2014
TL;DR: In this article, the authors present a tutorial for failure diagnosis in rotating machinery by means of active magnetic bearings, and demonstrate the use of magnetic bearings for vibration control and failure diagnosis.
Abstract: Mechanical systems: Equations of motion and stability.- Variational principles in mechanics and control.- Hybrid mass damper: A tutorial example.- Electromagnetic and piezoelectric transducers.- LMIs in control optimization.- Damping mechanisms.- Vibration control and failure diagnosis in rotating machinery by means of active magnetic bearings.
TL;DR: Experimental observation results of contact-induced vibration (CIV) and its compensator design in dual-stage hard disk drive servo systems reveal that the CIVs excite and amplify only the resonance modes of the system.
Abstract: This paper presents the experimental observation results of contact-induced vibration (CIV) and its compensator design in dual-stage hard disk drive servo systems, where the vibration is caused by the continuous contact of read/write head and recording media. Consistent relationships between the center frequencies and magnitudes of the vibration modes and the tested fly height, rotation speed, and track position are clearly observed and analyzed. It reveals that the CIVs excite and amplify only the resonance modes of the system. In consequence, the so-called PQ method is adopted to perform the compensator design. As such, the relative contributions to system output from the voice coil motor and lead-zirconium-titanate actuator subsystems can be well assigned in the frequency domain. The remarkable performance of the well-designed compensator is demonstrated by simulation.
TL;DR: In this paper, lead-free piezoelectric ceramics are investigated for active vibration control of piezolaminated composite shell structure, and the shell structure is in the form of layered composite...
Abstract: In this article, lead-free piezoelectric ceramics are investigated for active vibration control of piezolaminated composite shell structure. The shell structure is in the form of layered composite ...
TL;DR: The QZS vibration system is shown to be a useful device for absolute displacement measurement in vibration control systems particularly for moving platforms compared with the exciting methods and would benefit a wide range of engineering practices.
Abstract: Quasi-zero-stiffness (QZS) systems have been extensively studied and used as a useful vibration isolation device In this paper, the feasibility of the application of a QZS system for vibration measurement is investigated The structural parameters of the QZS system are first analyzed to ensure that the system is staying at stable equilibriums Comparisons of the absolute motion of a general and typical vibration platform (eg, a moving vehicle body) and the motion signal measured from the QZS system attached are then conducted to show the effectiveness of the method under different base excitations Moreover, the case under which the QZS-based sensor system may not behave well is also studied and potential solutions are discussed The QZS vibration system is shown to be a useful device for absolute displacement measurement in vibration control systems particularly for moving platforms compared with the exciting methods and would benefit a wide range of engineering practices
01 Feb 2014
TL;DR: In this paper, a method for improving machine tool performance by understanding and adaptively controlling the machine structural vibration is presented, where the first step is to measure and interpret machine tool vibration and produce a structural model.
Abstract: There is a requirement for improved three-dimensional surface characterisation and reduced tool wear when modern computer numerical control (CNC) machine tools are operating at high cutting velocities, spindle speeds and feed rates. For large depths of cut and large material removal rates, there is a tendency for machines to chatter caused by self-excited vibration in the machine tools leading to precision errors, poor surface finish quality, tool wear and possible machine damage. This study illustrates a method for improving machine tool performance by understanding and adaptively controlling the machine structural vibration. The first step taken is to measure and interpret machine tool vibration and produce a structural model. As a consequence, appropriate sensors need to be selected and/or designed and then integrated to measure all self-excited vibrations. The vibrations of the machine under investigation need to be clearly understood by analysis of sensor signals and surface finish measurement. The a...
TL;DR: In this article, a design methodology for multi-input multi-output vibration control of pedestrian structures to simultaneously obtain the sensor/actuator placement and the control law is proposed, which minimizes a performance index that includes all the significant practical issues involved when inertial-mass actuators and accelerometers are used to implement a direct velocity feedback in practice.
TL;DR: In this paper, the active vibration control of a structure modelled as a single degree of freedom system and excited by a white noise force is considered, and the optimisation of the physical and control parameters of the control system such as the internal damping of the actuator, its natural frequency and the feedback gain of the controller are considered such that either the kinetic energy of the host structure is minimised or the power dissipated by the controller is maximised.
TL;DR: The results show that the control technique can eliminate jump response modes and can significantly reduce mechanical stress associated with rub interaction of the rotor and stator.
Abstract: This brief describes an active control method to prevent unwanted nonlinear vibration response modes of a rotor-dynamic system. Nonlinear stiffness of components that support or surround a machine rotor can cause a response branch that extends critical vibration (resonance) over a wide interval of rotational speeds. Within this interval, jump transitions between alternative low amplitude and high amplitude response modes become possible. This brief explains how such behavior can be eliminated by applying control forces to the rotor based on dynamic feedback of strains measured in the stator structure. An optimal model-based controller synthesis is considered that combines a Lur'e-type Lyapunov function with a quadratic cost measure to penalize controller gain and bandwidth. Results are presented for an experimental flexible rotor system where nonlinear rotor-stator interaction occurs through a bearing with radial clearance. An active magnetic bearing applies control forces to the rotor in a separate plane. The results show that the control technique can eliminate jump response modes and can significantly reduce mechanical stress associated with rub interaction of the rotor and stator. The influence of key parameters in the model and controller formulation is shown.