Multi-modal Vibration Control Research Articles

Multi-modal vibration control of truss bridges with tuned mass dampers under general loading

Applications of tuned mass damper (TMD) systems for bridge structures are observed for mitigation of problem related to excessive vibration induced by either wind loading or vehicle loading, where dominant modes usually in one direction (commonly vertical) are taken into account. Considering modes dominant in one direction may not be considered as a robust practice while any bridge structure is having dominant modes along both the transverse and vertical directions and the same bridge structure is subjected to loading along both the directions. In the present study, an approach for simultaneous control of major horizontal, vertical and torsional modes is presented targeting robust vibration control under general loading condition. A strategy using modal frequency response function (FRF) is proposed based on the traditional mode-wise control approach. The proposed modal FRF based approach is applied to an existing important large truss bridge (Saraighat Bridge) to carry out an analytical design of TMD system considering general loading conditions. The designed TMD system is found to demonstrate good performance under various white-noise based general loading conditions.

Multimodal Vibration Control of Photo-Electric Laminated Thin Cylindrical Shells Via Self-Organizing Fuzzy Sliding Mode Control

In this paper, a novel multipiece actuator configuration is first proposed. This configuration exhibits several advantages over the existing ones, such as: (1) the ability to overcome the deficiency of one-way actuation of PbLaZrTi (PLZT) actuators and (2) all of the actuators in this configuration being placed on the inner surfaces of a thin cylindrical shell and the removal of extra electrical wires between the end surfaces of the actuators. A new index of modal control factors is defined, and an optimization method for allocating actuator is proposed. By using the proposed method, the PLZT actuators can be located in an optimum position. Moreover, in view of the nonlinear and time-variant characteristics of photostrictive actuators, a self-organizing fuzzy sliding mode control (SOFSMC) method is established to attenuate multimodal vibration of photo-electric laminated thin cylindrical shells. A multilevel sliding mode surface is defined as fuzzy input and the SOFSMC method is used to infer the applied light intensity. Its control rule bank can be developed and adjusted continuously via online learning. In addition, using fuzzy sliding mode, the chatter inherent in conventional sliding mode control is therefore managed effectively while ensuring sliding mode behavior. Case studies demonstrate that the proposed approach can efficiently suppress multimodal vibration of photo-electric laminated thin cylindrical shells. It is also founded that SOFSMC can achieve better control effect than fuzzy neural network control (FNNC).

Enhanced electromechanical coupling of piezoelectric system for multimodal vibration

An approach of enhancing the multimodal electromechanical coupling effect is proposed to improve the multimodal vibration control of piezoelectric systems. Theoretical research shows that when the electrode on the piezoelectric patch bonded on a vibrating structure is separated into several pieces, voltage response (including amplitude and phase) of each piece is different from each other. If each electrode is appropriately connected to the shunted circuit by certain design, the electromechanical coupling factor of the whole system can be increased effectively. In addition, the ‘current flowing circuit’ is introduced in the system to realize the multimodal vibration control. Experimental investigation has been carried out to validate the principle.

Adaptive positive position feedback for multi-modal vibration control of a flexible beam

The multi-modal vibration control of flexible structures is recognised as a significant challenge owing to the well-known phenomenon of spillover and frequency varying. Spillover phenomenon and variation in the modal dynamics may cause instability and degradation in performance. To overcome these defects, an adaptive positive position feedback (PPF) method is proposed for controlling the vibration of a flexible beam with bonded piezoelectric sensors and actuators. Finite element method is used for dynamic modelling of an experimental flexible beam. An online adaptive parameter estimator based on the gradient algorithm with parameter projection and a dead zone is presented to identify the modal frequencies in the presence of disturbances. Multi-modal PPF controller is adjusted with estimated frequencies and is able to damp the target modes quickly. Simulation results show that modal frequencies are estimated quite accurately and the vibration of the structure is significantly suppressed.

1512 多モード振動制御を目的としたセンサ・アクチュエータ最適配置方法に関する一検討(OS3-3 設計と最適化III,OS3 設計と最適化)

1512 多モード振動制御を目的としたセンサ・アクチュエータ最適配置方法に関する一検討(OS3-3 設計と最適化III,OS3 設計と最適化)

Fuzzy neural network multi-modal vibration control of thin cylindrical shells laminated with photostrictive actuators

In this paper, the multi-modal vibration control of a simply supported thin cylindrical shell laminated with photostrictive actuators is studied. First, the photo-electric/shell coupling equations of a cylindrical shell laminated with the multi-layer actuator configuration are presented. Moreover, in view of the nonlinear and time-variant characteristics of photostrictive actuators, a fuzzy neural network (FNN) controller with adaptive learning rates is developed to attenuate multi-mode vibration of photo-electric laminated thin cylindrical shells. This approach has learning ability for responding to the time-varying characteristic of the multi-mode vibration induced by disturbance. Its control rule bank can be established and modified continuously by on-line learning. Finally, numerical simulation results are provided to show that the proposed intelligent controller could effectively suppress multi-mode vibration of photo-electric laminated thin cylindrical shells.

Genetic algorithm based wireless vibration control of multiple modal for a beam by using photostrictive actuators

The lanthanum-modified lead zirconate titanate (PLZT) actuator, which are capable of converting photonic energy to mechanical motion, have great potential in applications of remote structural vibration control of smart structures and machines. In this paper, a novel genetic algorithm based controlling algorithm for multi-modal vibration control of beam structures via photostrictive actuators is proposed. Two pairs of photostrictive actuators are laminated with the beams and the alternation of light irradiation is in accordance with the changing of the corresponding modal velocity direction. The modal force indexes for beams with different boundary conditions are derived and a binary-coded GA is used to optimize the locations and sizes of photostrictive actuators to maximize the modal force index and guarantee the overall modal force index induced by two pairs of photostrictive actuators is positive. The control effect of multiple vibration modes of beams under irradiation of set/variable light intensity is analyzed. Numerical results demonstrate that the method is robust and efficient, and the use of strategically positioned actuator patches can effectively control the first two bending modes that dominate the structural vibration.

Multi-modal vibration control using amended disturbance observer compensation

Piezoelectric panel is a fundamental element in many structures characterised with multi-variables, coupling and uncertain external excitation. Many advanced active control schemes have been reported for the multi-modal of piezoelectric structure. However, these control schemes, including the multi-loop PID method usually cannot achieve satisfying performance in the presence of strong external disturbances and coupling effects. To this end, an amended disturbance observer (DOB) based on multi-loop PID scheme is developed to control a two-mode piezoelectric panel. The system considered here is with lumped disturbances including external disturbances, such as the variations of the output of the modal and the external excitation, and internal disturbances, such as coupling effects. The proposed control approach consists of two compound controllers, and each controller includes a PID feedback part and a feed-forward compensation part based on DOB for disturbances. In order to obtain a better vibration suppressing performance, a chaos optimisation method based on Logistic map and a new transient performance function is designed to tune the parameters of PID controller. A rigorous analysis is also given to show why the DOB can effectively suppress the variations. At last, in order to verify the proposed algorithm, the dSPACE real-time simulation platform is used and an experimental platform for the all-clamped stiffened panel structure active vibration control is set up. The simulation and experiment results demonstrate that the proposed method has a much better vibration suppressing property with almost the same input voltage than the multi-loop PID method in the piezoelectric panel.

234 アクティブマスダンパを用いた鉄道車両の車体弾性振動の多モード制振 : 小型化に向けた加振試験

234 アクティブマスダンパを用いた鉄道車両の車体弾性振動の多モード制振 : 小型化に向けた加振試験

Active multimodal vibration suppression of a flexible structure with piezoceramic sensor and actuator by using loop shaping

This paper represents active multimodal vibration control of a flexible beam structure with piezoceramic (PZT) actuators and sensors using the loop shaping method. With surface-bonded PZT patch actuators and sensors, the flexible beam has both sensing and actuating capacities. Due to its flat auto spectrum in the specified frequency range, the Schroeder wave is used as an excitation signal for the non-parametric identification of the flexible beam structure. The identified open loop model is then used for the closed loop design by using the loop shaping method based on the extended sensitivity charts. A loop shaping compensator is designed to achieve multimodal vibration suppression. Numerical results showed a reduction of 8 decibels for the first mode and 12–14 decibels for the second and third modes. Experimental results closely match the simulation results. Furthermore, the results of loop shaping method are compared with those of the methods of linear quadratic regulator and pole-placement control, which are designed based on state space models via the parametric identification of the flexible beam. Comparisons show that the loop shaping method is easier to design since a parametric identification is not required and requires less control effort while maintaining the effectiveness in vibration suppression.

Multimodal Vibration Control of Elastic Vibration of Railway Vehicle Carbody Using Active Mass Dampers (A Method for Making and Updating Analytical Model and Fundamental Test Using Actual Vehicle)

Recent light-weighted and structurally-simplified railway vehicle carbodies tend to have complicated three dimensional elastic vibration modes and such vibration modes affect riding quality. In particular, it is known that the mode similar to the first mode of free supported elastic beam (“B mode”) and diagonal distortion mode (“D mode”) whose natural frequencies are around 10Hz are important because 10Hz is known to be a sensitive frequency range for human. In this paper, a method aiming at reducing the two modes (B mode and D mode) simultaneously by using two active mass dampers (AMDs) is suggested, and its feasibility is examined numerically and experimentally. A simple analytical model which can express complicated 3D elastic vibrations of carbody is introduced, and the way to obtain appropriate model parameters is proposed employing genetic algorithm (GA). Using the analytical model including bogies and AMD models, the capability to reduce those two target elastic modes is investigated. A stationary excitation test for a commuter type test vehicle is then carried out using an electro-dynamic exciter. The peaks corresponding to those two target modes are reduced successfully when AMDs are applied in the excitation test.

New Semi-active Multi-modal Vibration Control Using Piezoceramic Components

Active vibration control using piezoelectric elements has been extensively studied due to the requirement for increasingly high performances. Semi-active control, such as Synchronized Switch Damping, is an alternative technique. It consists in switching a piezoelectric element to a specific circuit synchronously with the motion of the structure, unlike active control. This method requires very low power supply, but performances remain poor in the case of broad bandwidth excitation. This article proposes a new method which is a combination of the SSDI semi-active control and technique developed for active control and has low power supply requirements. It extends semi-active control to any type of excitation, while optimizing modal damping on several targeted modes. Experimental measurements carried out on a clamped free beam are presented and a significant damping on targeted modes is demonstrated.

Multi-modal vibration control using a synchronized switch based on a displacementswitching threshold

A new semi-active method for multi-mode vibration control using the nonlinearsynchronized switch damping (SSD) approach based on a displacement switching thresholdis proposed in this paper. Several extensions of the SSD approach, including SSDI (SSD oninductance), SSDV (SSD on a voltage source), enhanced SSDV, and adaptive SSDV, havebeen developed to improve the control of the single-mode vibration, but the weaknessof the SSD approach for multi-modal vibration control has not been solved. Inall these extensions of the SSD approach, the switch is controlled by the samealgorithm, that is, it reverses the voltage of the piezoelectric element at all extrema ofdisplacement. This switching algorithm is effective in single-mode control, but it leads toover-frequent switching in multi-mode control. In the method proposed in thisstudy, an improved switching algorithm based on a displacement threshold, whichprevents the switch in the shunt circuit from over-frequent on-and-off actions andaccordingly increases the converted energy to improve the control performance, isproposed. The switching algorithm is applied to an SSDI system and used in thevibration damping of a beam with two excited modes. Compared to the classicalSSDI approach, the control performance of the first mode is improved from 3.7 to18.2 dB, but that of the second mode is slightly worse, having changed from 3.46 to2.6.

Multimodal passive vibration control of sandwich beams with shunted shear piezoelectricmaterials

This work presents a performance analysis of multimodal passive vibration control of asandwich beam using shear piezoelectric materials, embedded in a sandwich beam core,connected to independent resistive shunt circuits. Shear piezoelectric actuators wererecently shown to be more interesting for higher frequencies and stiffer structures. Inparticular, for shunted damping, it was shown that equivalent material loss factors of up to31% can be achieved by optimizing the shunt circuit. In the present work, special attentionis given to the design of multimodal vibration control through independent shunted shearpiezoelectric sensors. In particular, a parametric analysis is performed to evaluateoptimal configurations for a set of modes to be damped. Then, a methodology toevaluate the modal damping resulting from each shunted piezoelectric sensoris presented using the modal strain energy method. Results show that modaldamping factors of 1%–2% can be obtained for three selected vibration modes.

Self-powered circuit for broadband, multimodal piezoelectric vibration control

Vibration control using piezoelectric actuators has experienced a strong development these last years. Particularly, non-linear techniques have been proven to be low-cost and efficient ways of damping, with self-powering capabilities. This paper deals with one of these methods, the so-called self-powered synchronized switch damping on inductor (SSDI). Its principles rely on switching intermittently the piezoelement on a resonant circuit. Particularly, it is proposed here a new self-powered device that enhances the broadband nature of the self-powered SSDI. The principles of the circuit are to disable the switching event unless a particular condition is fulfilled. Experimental results show that such a circuit significantly improves the multimodal control abilities of the self-powered SSDI techniques without any external power supply requirements.

Multimodal Vibration Control of a Flexible Structure using Piezoceramic Sensor and Actuator

This study presents results of multimodal vibration suppression of a smart flexible cantilever beam with piezoceramic actuator and sensor by using a pole placement controller. Piezoceramic PZT (lead zirconate titanate) patches are surface-bonded on the beam and function as actuator and sensor. Nonparametric identification for the dynamics of the first three modes is carried out. From the nonparametric model, a parametric model is identified to assist the control system design. The identified model is used for state estimation and development of control algorithm. A linear pole placement controller is designed and simulated using the identified model. Experimental results demonstrate the effectiveness of observer-based multimodal active vibration control of the structure using piezoceramic smart materials.

637 圧電フィルム積層型スマートダンパによる平板の多モード振動制御

Piezoelectric film has two effects of direct piezoelectric effect and inverse piezoelectric effect. These effects can be used for the vibration control of flexible structures. In the authors' previous reports, a self-sensing actuator with laminated piezoelectric films was proposed and the vibration control effects against first and second mode of a beam and first mode of a rectangular plate were shown. However, vibration control effect against multimode of two-dimensional structure was not shown yet. Therefore, in this paper, a self-sensing actuator using laminated triangular piezoelectric films was proposed and its analytical model was derived. Then the validity of the proposed method was shown by comparing the results of an experiment of applying voltage to a triangular piezoelectric film actuator bonded on the plate, with that of theoretical analysis. Finally, multimodal vibration control of simply-supported plate was studied by numerical analysis.

2213 磁気軸受によるフレキシブルロータの多モード振動制御(磁気浮上・磁気軸受の制御(2))

2213 磁気軸受によるフレキシブルロータの多モード振動制御(磁気浮上・磁気軸受の制御(2))

Multimode vibration control of a smart model frame structure

This paper investigates multimodal vibration control of a three-story model structuralframe by using surface bonded PZT (lead zirconate titanate) type piezoceramic patches.Piezoceramic is one of the smart materials. Complete control systems design is synthesizedon the model frame using system identification and a pole placement controller. A timedomain based subspace system identification is performed to identify the firstthree modes of the structural frame. A fit of 90% is achieved in identificationresults. A full-state pole placement feedback controller is designed based on theidentified model. To implement the full-state feedback controller, the design of a stateestimator is also performed. Experimental results demonstrate the effectiveness ofmultimodal active control of the smart frame structure using pole placement control.

A Novel Semi-Active Multi-Modal Vibration Control Law for a Piezoceramic Actuator

In this paper, a novel semi-active energy rate multi-modal vibration control technique is developed for a piezoceramic actuator coupled to a switching resistor/inductor shunt. The technique works by briefly connecting a resistor/inductor shunt to a piezoceramic actuator in order to apply the necessary signed charge to allow energy dissipation. The switch timing is determined by a control scheme that observes the rate of energy change in controlled modes. The control scheme is developed in the paper, and is simplified to enable practical implementation. This new multi-modal control law is applied to both a simple numerical and an experimental test structure. The results from the numerical and experimental tests show that the energy rate multi-mode control law is able to dissipate energy from one, two and three modes of the flexible structures using a single actuator.