Showing papers on "Active vibration control published in 2011"
TL;DR: High accuracy, high speed, and high power microrobot, swine oocyte manipulations are presented in a microfluidic chip and the output force is increased twice as much by the ultrasonic vibration.
Abstract: This paper presents an innovative driving method for an on-chip robot actuated by permanent magnets in a microfluidic chip. A piezoelectric ceramic is applied to induce ultrasonic vibration to the microfluidic chip and the high-frequency vibration reduces the effective friction on the MMT significantly. As a result, we achieved 1.1 micrometre positioning accuracy of the microrobot, which is 100 times higher accuracy than without vibration. The response speed is also improved and the microrobot can be actuated with a speed of 5.5 mm s−1 in 3 degrees of freedom. The novelty of the ultrasonic vibration appears in the output force as well. Contrary to the reduction of friction on the microrobot, the output force increased twice as much by the ultrasonic vibration. Using this high accuracy, high speed, and high power microrobot, swine oocyte manipulations are presented in a microfluidic chip.
165 citations
TL;DR: In this article, a linear model of magnetostrictive actuators that is valid in a range of frequencies below 2 kHz is presented. And the model is validated through experimental tests carried out on two different magnetic actuators.
Abstract: One of the most frequent applications of magnetostrictive actuator technology is the active structural vibration control (AVC). Magnetostrictive actuators (MAs) can deliver high-output forces and can be driven at high frequencies. These characteristics make them suitable for a variety of vibration control applications. The use of this technology, however, requires an accurate knowledge of the dynamics of such actuators. Several models are available in the literature. However, their use in control applications, characterized by high dynamics, is often limited by nonlinearities and complexity of the model. To overcome this difficulty, the paper introduces a linear model of magnetostrictive actuators that is valid in a range of frequencies below 2 kHz. The assumptions supporting the linearity of the system are discussed and the theoretical model is presented. Finally the model is validated through experimental tests carried out on two different magnetostrictive actuators.
104 citations
TL;DR: It is shown that with appropriate control techniques the variance of the load signals can be reduced up to 90% and the load reduction potential of a prototyped “smart” rotor is studied.
Abstract: This paper studies the load reduction potential of a prototyped “smart” rotor. This is, a rotor where the blades are equipped with a number of control devices that locally change the lift profile on the blade, combined with appropriate sensors and controllers. Experimental models, using dedicated system identification techniques, are developed of a scaled rotating two-bladed “smart” rotor of which each blade is equipped with trailing-edge flaps and strain sensors. A feedback controller based on H∞-loop shaping combined with a fixed-structure feedforward control are designed that minimizes the root bending moment in the flapping direction of the two blades. We evaluated the performance using a number of different realistic load scenarios. We show that with appropriate control techniques the variance of the load signals can be reduced up to 90%.
98 citations
TL;DR: In this article, the authors investigated the feasibility of using a DEAP actuator in active vibration isolation (AVI) by placing an active isolator between an electrodynamic shaker and a mass.
85 citations
TL;DR: In this article, a simple analytical method for predicting the maximum reduction levels of vibration and noise by active vibration cancellation (AVC), compared with the conventional excitation, is presented. And its predicted results are then verified by experiments on a prototype 6/4 SRM.
Abstract: High acoustic noise and vibration is one of the main drawbacks, which has limited the wide application of switched reluctance machine (SRM), especially when it is noise and vibration sensitive. Therefore, many studies have been carried out to reduce the acoustic noise and vibration of SRM. One attractive and effective method is the active vibration cancellation (AVC) proposed by Wu and Pollock, which is easy to realize without increasing any hardware. This paper presents a simple analytical method for predicting the maximum reduction levels of vibration and noise by AVC, compared with the conventional excitation. Its predicted results are then verified by experiments on a prototype 6/4 SRM.
85 citations
TL;DR: The nonlinearities in a dielectric elastomer (DE) actuator and their consequences for dynamic applications are analyzed on a theoretical level first and then shown to be practically relevant in an experimental setup.
Abstract: Electroactive polymers (EAPs) have been widely employed as smart material for actuators in recent years. Numerous investigations have focused on static or quasi-static applications. For the use as actuators in the field of active vibration control (AVC); however, the dynamic behavior needs to be studied in detail and the inherent nonlinear effects demand new control concepts. Since AVC applications have only recently been considered for EAP actuators, only a few studies have been published in this area so far . In this paper, the nonlinearities in a dielectric elastomer (DE) actuator and their consequences for dynamic applications are analyzed on a theoretical level first and then shown to be practically relevant in an experimental setup. Afterward, two compensation methods are presented and their improving influence on the dynamic behavior proven. Finally, the DE actuator is included in an active closed-loop control system and its potential for AVC demonstrated. Furthermore, a MATLAB/SIMULINK model of the whole system is presented, its general validity shown, and its potential for future system development processes highlighted.
78 citations
TL;DR: In this article, an active vibration control to suppress structural vibration of the smart hull structure was investigated based on optimized actuator configurations using anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the vibration control.
71 citations
TL;DR: In this paper, the problem of attenuation (rejection) of unknown and time varying multiple narrow band disturbances without measuring them is addressed and a review of the direct and indirect adaptive regulation strategies using the internal model principle and the Youla-Kucera parametrization.
71 citations
TL;DR: A general dynamic model of a class of parallel platforms for vibration control applications based on Kane's method is presented in this paper, where a general parallel platform is composed of a moving platform, a base platform, and i limbs with identical kinematic structure.
70 citations
TL;DR: In this article, a feedback law is used to couple the dynamic of a simplified rotor-bearing system with the pneumatic and dynamic characteristics of a piezoelectric actuated valve system.
70 citations
TL;DR: In this article, the active aeroelastic flutter characteristics and vibration control of supersonic beams applying the piezoelectric material are studied further using the assumed mode method.
Abstract: The active vibration control of all kinds of structures by using the piezoelectric material has been extensively investigated. In this paper, the active aeroelastic flutter characteristics and vibration control of supersonic beams applying the piezoelectric material are studied further. The piezoelectric materials are bonded on the top and bottom surfaces of the beams to act as the actuator and sensor so that the active aeroelastic flutter suppression for the supersonic beams can be conducted. The supersonic piston theory is adopted to evaluate the aerodynamic pressure. 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 solutions for the complex eigenvalue problem are obtained. A negative velocity feedback control strategy is used to obtain active damping. The aeroelastic flutter bounds are calculated and the active aeroelastic flutter characteristics are analyzed. The impulse responses of the structural system are obtained by using the Houbolt numerical algorithm to study the active aeroelastic vibration control. The influences of the non-dimensional aerodynamic pressure on the active flutter control are analyzed. From the numerical results it is observed that the aeroelastic flutter characteristics of the supersonic beams can be significantly improved and that the aeroelastic vibration amplitudes can be remarkably reduced, especially at the flutter points, by using the piezoelectric actuator/sensor pairs which can provide an active damping. Within a certain value of the feedback control gain, with the increase of it, the flutter aerodynamic pressure (or flutter velocity) can be increased and the control results are also improved.
TL;DR: In this article, a vibration control strategy for a flexible manipulator with a collocated piezoelectric sensor/ actuator pair is presented, which combines the input shaping technique with multimode adaptive positive position feedback.
Abstract: DOI: 10.2514/1.52287 This paper presents a vibration control strategy for a flexible manipulator with a collocated piezoelectric sensor/ actuator pair. Dynamic modeling of the flexible manipulator is first shown, and then a control law is developed. The proposed vibration controller combines the input shaping technique with multimode adaptive positive position feedback. An adaptive parameter estimator based on the recursive least-square method is developed to update the system’s natural frequencies, which are used by the adaptive positive position feedback. A proportional-derivative controller is combined with the proposed vibration controller to suppress vibration while slewing the manipulator. Simulation results are presented to illustrate the efficacy of the proposed controller.
TL;DR: In this paper, a control law for active structural vibration control using piezoelectric patches at elevated temperatures is derived and experimentally verified using augmented constitutive equations, which includes the temperature dependence of piezolectric stress coefficient (e31) and permittivity.
Abstract: A new scheme for active structural vibration control using piezoelectric patches at elevated temperatures is analytically derived and experimentally verified A control law is derived using augmented piezoelectric constitutive equations which include the temperature dependence of piezoelectric stress coefficient (e31) and permittivity Since the temperature dependence of 'e31' and '' is not analytically known, their experimental values measured at elevated temperatures are used Using augmented constitutive equations, a finite element model of a smart two-dimensional isotropic plate instrumented with a collocated piezoelectric sensor?actuator pair is derived A control law for active vibration control of the first mode of the smart cantilevered plate is derived using negative velocity feedback Active vibration control of the first mode of a smart cantilevered plate is experimentally achieved at elevated temperatures ranging from 25 to 75??C under two cases: (i)?using a control law which ignores the temperature dependence of 'e31' and '' and (ii)?using a control law which includes the temperature dependence of 'e31' and '' A comparison between these two control laws shows that: (i)?active vibration control (AVC) performance is not maintained at elevated temperatures using a control law which ignores the temperature dependence of 'e31' and '' and (ii)?AVC performance is maintained at elevated temperatures when we use a control law which includes the temperature dependence of 'e31' and ''
TL;DR: New algorithms for the adaptive feedforward compensation with both filtering of data and of the residual acceleration and using an "Integral + Proportional" (IP) adaptation as a means for accelerating the transients as well as for relaxing the positive real conditions required by the stability analysis are proposed.
TL;DR: In this paper, the authors presented a self-powered vibration damping technique, which is an application of the enhanced synchronized switching harvesting (ESH) technique, and demonstrated that the system can not only show its robustness (particularly facing environmental drifts), but also can harvest the energy and supply power to other electronic circuits.
Abstract: This paper presents a new self-powered vibration damping technique, which is an application of the enhanced synchronized switching harvesting technique. Compared with other self-powered vibration damping techniques, it not only shows its robustness (particularly facing environmental drifts), but also can harvest the energy and supply power to other electronic circuits, while does not simply dissipate the electrical energy. Experimental results show that a vibration damping of about 5 dB is achieved as a result of energy harvesting, in good agreement with the theory. In addition, the vibration damping system can be not only self-powered, but also supply power to other electronic circuits. In other words, there is a good trade-off between energy scavenging and vibration damping. Along with experimental results demonstrating the effectiveness of the ESSH implementation, we discuss the design of a device aimed at bridging the gap between research in this area and practical application.
TL;DR: In this paper, the use of dynamic vibration absorbers to control the vibration of a structure in both narrow and broadbands is discussed, and the coupling properties due to the introduction of the absorber into the host structure are analyzed; and the control performance of the vibration absorber in different control bandwidths is examined with respect to its damping and location.
TL;DR: In this paper, the authors developed an active vibration control system for a light and flexible stress ribbon footbridge, where very light pneumatic muscle actuators are placed at handrail level, introducing control forces.
TL;DR: In this article, the authors theoretically investigated the use of inertial actuators to reduce the sound radiated by a submarine hull in bending vibration under harmonic excitation from the propeller.
TL;DR: An active vibration control system using an inertial actuator for suppression of multiple unknown and/or time-varying vibrations will be presented and a comparison with an alternative indirect adaptive regulation scheme is presented.
Abstract: An active vibration control system using an inertial actuator for suppression of multiple unknown and/or time-varying vibrations will be presented. The objective is to minimize the residual force by applying an appropriate control effort through the inertial actuator. The system does not use any additional transducer for getting in real-time information upon the disturbances. A direct feedback adaptive regulation scheme for the suppression of multiple unknown and/or time-varying vibrations will be used and evaluated in real time. It uses the internal model principle and the Youla-Kucera parametrization. In the Appendix, a comparison with an alternative indirect adaptive regulation scheme is presented.
TL;DR: In this article, a magnetorheological fluid embedded pneumatic vibration isolator (MrEPI) with hybrid and compact connection of PNE and MR damping elements is proposed.
Abstract: A magnetorheological (MR) fluid embedded pneumatic vibration isolator (MrEPI) with hybrid and compact connection of pneumatic spring and MR damping elements is proposed in this study. The proposed MrEPI system allows independent nonlinear stiffness and damping control with considerable maneuverable ranges. Meanwhile, it allows convenient switching between different passive and active vibration control modes, thus providing more flexibility and versatility in applications. To demonstrate the advantageous dynamic performance of the MrEPI, a nonlinear non-dimensional dynamic model is developed with full consideration of the nonlinear elements involved. A systematic analysis is therefore conducted which can clearly reveal the influence on system output performance caused by each physically important parameter and provide a useful insight into the analysis and design of nonlinear vibration isolators with pneumatic and MR elements.
TL;DR: In this paper, a comparison of fuzzy logic and PID controlled active suspensions' performances on an 11 degree-of-freedom rail vehicle model is presented, where a fuzzy logic controller and a PID controller are designed for the same model separately to obtain a comfortable travel for the users.
Abstract: This study represents the comparison of fuzzy logic and PID controlled active suspensions' performances on an 11 degree-of-freedom rail vehicle model. First, a PID controller and then a fuzzy logic controller (FLC) are designed for the same model separately to obtain a comfortable travel for the users. Since the PID control method can be applied easily and is well known, it has an important place in control applications and a FLC is preferred because of its superior performance in active vibration control. Controllers are used to secondary suspension systems placed between rail vehicle and bogie. This vehicle is modeled as a lumped parameter system which consists of a body, bogie, primary and secondary suspensions and rigid wheels. The model has been designed to take into account the complexity of wheel-rail contact. For the purpose of observing both controllers' performances, two different track irregularities are considered as disruptive effects of the system. All parameters for both controllers are achieved by the use of genetic algorithm for the same simulation conditions and performance criteria. At the end of the study, time history and frequency response for accelerations and displacements of the rail vehicle are presented for both uncontrolled and controlled systems. Performances of the compared approaches are discussed.
TL;DR: Considering the spillover and harmonic effect in real active vibration control, a novel composite controller based on disturbance observer (DOB) for the all-clamped panel is presented in this article.
TL;DR: In this article, a module-type three-degree-of-freedom vibration isolation system using modified zero-power control is proposed, which consists of a common base, an individual middle mass and a common isolation table.
TL;DR: In this article, the authors present the finite element modeling of laminate composite plates with embedded piezoelectric patches or layers that are then connected to active-passive resonant shunt circuits, composed of resistance, inductance and voltage source.
TL;DR: In this paper, a non-time based control strategy for the simultaneous active vibration control and path tracking of multi-degree-of-freedom linear systems is proposed, which allows reducing elastic vibrations while guaranteeing coordinated motion among the system rigid-body degrees of freedom, and hence accurate tracking of desired paths through space.
TL;DR: In this article, the authors studied the vibration suppression of an end-capped cylindrical shell structure with surface bonded macro fiber composite actuators and found that structural vibration was reduced by adopting a proper negative velocity feedback control algorithm in both resonance and non-resonance regimes.
Abstract: We studied the vibration suppression of an end-capped cylindrical shell structure with surface bonded macro fiber composite actuators. The dynamic characteristics of the cylindrical shell structure were first analyzed, and then a negative velocity feedback algorithm was applied to suppress the structural vibration at resonance and nonresonance vibration frequencies. The modal mass and stiffness matrix of the smart cylindrical shell structure were extracted for the controller design. An active controller was designed to suppress vibration of the smart structure, and the control performance was evaluated in resonance and nonresonance regimes. It was found that structural vibration was reduced by adopting a proper negative velocity feedback control algorithm in both resonance and nonresonance regimes.
TL;DR: In this paper, the optimal location and number of piezoelectric sensors for active vibration control is formulated for a thin plate, and a genetic algorithm is proposed to solve this bi-objective optimization problem.
Abstract: In this article, the optimal location and number of piezoelectric sensors is formulated for active vibration control. A modified criterion is used to ensure good observability of the system by considering the minimum number of needed piezoelectric elements. A genetic algorithm is proposed to solve this bi-objective optimization problem. Simulations are presented for a thin plate.
TL;DR: In this paper, an active vibration control of a simply supported rectangular plate made from functionally graded materials (FGM) with fuzzy logic control (FLC) is investigated and compared to the results obtained with the application of PID control.
TL;DR: In this paper, the effect of inertial coupling among transverse and torsional coordinates through mass-unbalance and gyroscopic effect was analyzed for a flexurally compliant rotor-shaft.
Abstract: Rotor–shaft systems are subject to non-uniform spin speed during start-up, coast-down or any non-stationary situation changing the spin speed suddenly, e.g., load fluctuation or sudden mass-loss like loss of a blade or a part thereof. For a flexurally and torsionally compliant rotor-shaft, the dynamics under non-uniform spin-speed shows inertial coupling among transverse and torsional coordinates through mass-unbalance and gyroscopic effect. This results into coupled transverse-torsional vibration, where torsional response consists of significant harmonic components at bisynchronous spin frequency, torsional natural frequency of the shaft, and at combination frequencies corresponding to sum and difference of spin and transverse natural frequencies and twice the transverse natural frequency of the rotor-shaft. As a result of the coupling, transverse rotor motion also influences the torsional motion. The Method of Multiple Scales (MMS) is used in this work to carry out an analysis of a simplified system to get an idea about the dominant frequencies of excitation. Results of numerical simulation are presented next to show the effectiveness and influence of actively controlling the transverse rotor motion on its torsional motion, at the dominant frequencies, with the help of non-contact electromagnetic force from an actuator. Transverse vibration control is also observed to control the torsional oscillations due to coupled nature of the problem. The Stability Limit Speed (SLS) of the system is also increased as a result of application of the active control action. Constant axial torque is observed to diminish the influence of coupling, and protect the system against torsional instability, but control action is a must to stabilize the transverse vibration of the system above SLS.
TL;DR: In this paper, a new type of a MR damper is proposed for an integrated isolation mount for an ultraprecision manufacturing system, which can eliminate a dry friction of the damper to remove the tiny vibration as well as can produce enough damping force to attenuate the transient vibration.
Abstract: This article presents a new type of a MR damper designed for an integrated isolation mount for an ultraprecision manufacturing system. The vibration sources of the ultraprecision system can be classified as two: one is environmental vibration from the floor, and the other is transient vibration occurred from the stage movement. The transient vibration occurred from the stage movement has adverse effect to the manufacturing process because the vibration scale is quite larger than other vibrations. It is also known that the moving stage needs to be isolated from tiny vibrations to be occurred from the floor. Therefore, in this research in order to attenuate both the transient and tiny vibrations, a new type of MR damper is proposed and its performance is evaluated. The proposed MR damper can eliminate a dry friction of the damper to remove the tiny vibration as well as can produce enough damping force to attenuate the transient vibration. The MR damper is designed on the basis of Bingham model of a MR fluid...