Multimodal Vibration Suppression Research Articles

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.

Multi-mode vibration reduction of a CD-ROM drive base using a piezoelectric shunt circuit

This paper presents a new design methodology for the piezoelectric shunt damping system and applies to the multimode vibration suppression of a CD-ROM drive base. Admittance is introduced to predict the performance of the piezoelectric shunt damping. Numerical admittance obtained by commercial finite element code, ANSYS, is compared with experimentally measured one and the effectiveness of the model is verified. Multimode piezoelectric shunt damping is experimentally realized based on the target mode and frequencies obtained by the admittance analysis. The vibration of the CD-ROM drive base is effectively reduced by activating the piezoelectric shunt circuits. The experimental results presented in this work prove that admittance of the piezoelectric structure is capable of predicting the performance of piezoelectric shunt damping.

Spacecraft Vibration Suppression Using Variable Structure Output Feedback Control and Smart Materials

A hybrid control scheme for vibration reduction of flexible spacecraft during rotational maneuvers is investigated by using variable structure output feedback control (VSOFC) for attitude control and smart materials for active vibration suppression. The proposed control design process is twofold: design of the attitude controller using VSOFC theory acting on the hub and design of an independent flexible vibration controller acting on the flexible part using piezoceramics as sensors and actuators to actively suppress certain flexible modes. The attitude controller, using only the attitude and angular rate measurement, consists of a linear feedback term and a discontinuous feedback term, which are designed so that the sliding surface exists and is globally reachable. With the presence of this attitude controller, an additional independent flexible control system acting on the flexible parts is designed for further vibration suppression. Using the piezoelectric materials as actuator/sensor, both single-mode vibration suppression and multimode vibration suppression are studied and compared for the different active vibration control algorithms, constant-gain negative velocity feedback (CGNVF) control, positive position feedback (PPF) control, and linear-quadratic Gaussian (LQG) control. Numerical simulations demonstrate that the proposed approach can significantly reduce the vibration of the flexible appendages and further greatly improve the precision during and after the maneuver operations.

Modeling and design of passive electric networks interconnecting piezoelectric transducers for distributed vibration control

In the literature collocated or distributed arrays of piezeoelectric patches are employed to actively control structural vibrations. In the present work in order to damp beam vibrations a completely passive electric controller is designed, exploiting distributed piezoelectric transduction. In this way a simultaneous multimodal vibration suppression is obtained. The optimal electric network (interconnecting the piezoelectric transducers) is synthesized as a finite differences approximation of the derived distributed (infinite dimensional) optimal controller. A prototype of the proposed novel smart structure (Piezo-ElectroMechanical beam) is designed, allowing for appreciating its technical feasibility and effectiveness.

Multimode vibration suppression with passive two-terminal distributed network incorporating piezoceramic transducers

The design of an inductance/capacitance two-terminal distributed passive electric network for simultaneously controlling several flexural modes of vibration is discussed. The efficiency of the network to annul multimode vibrations of simply supported, clamped–clamped and cantilever beams is demonstrated.

Modified input shaping for a rotating single-link flexible manipulator

Input shaping is a feedforward approach and can be applied to suppress flexible vibration. In this paper, modified input shaping (MIS) is proposed for robustness and multimode vibration suppression. The theoretic analysis shows that the MIS poses better performance in several aspects than the traditional input-shaping technique. The controller that combines MIS with PD feedback law is designed for an experimental single-link flexible manipulator. Hardware experiments are conducted to verify the proposed method.

Multimodal beam vibration damping exploiting PZT transducers and passive distributed circuits

Structures are subject to extensive vibrations that can reduce their life and contribute to failure. Piezoelectric transducers in conjunction with appropriate electric networks, can be used as a mechanical energy dissipation device. Most of the previous work has focused on active control in which electric power is supplied to the actuators that exert actions on the host structure to suppress its vibrations. Alternatively, undesired mechanical energy of a host structure could be converted into electrical energy that can be dissipated through a set of resistor. This does not require an external power unit and is a more economical means of controlling vibrations of a structure, but an effective transduction of mechanical energy into electric energy has to be guaranteed. Therefore, in the present work a completely passive distributed electric controller is found to achieve simultaneous beam multimodal vibration suppression. The optimal electric network (interconnecting the piezoelectric transducers) may be synthesized as a finite differences approximation of the derived distributed (infinite dimensional) optimal controller.

Active Vibration Damping of Composite Beam using Smart Sensors and Actuators

This paper discusses active vibration control of an E-glass/epoxy-laminated composite beam using smart sensors and actua- tors. The smart sensors and actuators used in this study are piezoelectric ceramic patches. The composite beam is in a cantilevered configuration. Both theoretical and numerical ~finite-element analysis! studies of the laminated composite beam are conducted to reveal the beam's fundamental modal frequencies and modal shapes. The results based on the theoretical predication and numerical simulation are then compared with those from experimental modal testing, and a good correlation is obtained. Utilizing results from the model analysis and experimental modal testing, two control algorithms, namely, positive position feedback control and strain rate feedback control, are designed. Both single-mode vibration suppression and multimode vibration suppression are studied. An experimental appa- ratus has been developed to implement the control algorithms. The apparatus consists of a voltage amplifier and a data acquisition and real-time control system, in addition to the composite beam with bonded piezoelectric ceramic sensors and actuators. Experiments show that the proposed controllers can achieve active vibration damping of the composite beam.

광섬유 센서와 압전 작동기를 이용한 평판의 최적 진동 제어

Vibration control of a plate using an optical fiber sensor and a piezoelectric actuator is considered in the present study, An aluminum plate with attached Extrinsic Fabry-Perot Interferometer (EFPI) and piezoelectric actuator is prepared for experimental investigation. Vibration level of EFPI that can represent the mechanical strain without severe distortion Is validated by forced nitration experiment. A linear time invariant system model is constructed based on the experimentally obtained frequency responses, and an optimal controller is designed for the multi-modal vibration suppression. Control performance is presented in frequency and time domains. It is found that the nitration level of the first three modes can be greatly reduced. The effect of low-pass filtering used to eliminate high frequency noise on the stability and control performance is also considered.

Active vibration suppression of a flexible structure using smart material and a modular control patch

This paper presents experimental results of vibration suppression of a flexible structure using smart materials and a miniaturized digital controller, called the modular control patch (MCP). The MCP employs a TI-C30 digital signal processor and was developed by TRW for the United States Air Force for future space vibration control. In this research, the MCP is used to implement different control algorithms for vibration suppression of a cantilevered aluminium beam. The beam is equipped with smart sensors and actuators, and both are made of piezoceramics. Positive position feedback (PPF) control, strain rate feedback (SRF) control and their combinations were implemented. Experiments found that PPF control is most effective for single-mode vibration suppression, and two PPF filters in parallel are most effective for multimode vibration suppression. Experiments also demonstrated the capacity of smart material being used as sensors and actuators for vibration suppression. The MCP was shown to be capable of implementing various real-time control laws.

Vibration Control of Rotationally Periodic Structures Using Passive Piezoelectric Shunt Networks and Active Compensation

This paper proposes a multi-mode vibration suppression scheme for rotationally periodic structures. Identical active-passive hybrid piezoelectric networks are applied on each of the substructures, where active charge and current feedback is used together with passive piezoelectric shunts to optimize the network performance. By exploiting the rotational periodicity, a new algorithm is synthesized to analytically determine the control parameters. It is shown that this hybrid approach can suppress all the spatial harmonics, which cannot be achieved by purely passive piezoelectric shunts. It is also observed that such a configuration requires much less control effort (voltage and power) when compared to a purely active approach.

Multimodal Passive Vibration Suppression with Piezoelectric Materials and Resonant Shunts

Passive piezoelectric damping devices are studied. These devices, consisting of a piezoelectric element and a resonant shunt, are analogous to mechanical damped vibration ab sorbers. In the past, a single piezoelectric device has been used to suppress a single structural mode. In this paper, the theory is expanded so that a single piezoelectric element can be used to suppress multiple modes. The multimode damper is demonstrated experimentally as a two-mode device ap plied to a cantilevered beam.