Active Vibration Control Based on Self-Sensing for Unknown Target Structures by Direct Velocity Feedback With Adaptive Feed-Forward Cancellation

Author(s):  
Shota Yabui ◽  
Itsuro Kajiwara ◽  
Ryohei Okita

This paper presents active vibration control based on self-sensing for unknown target structures by direct velocity feedback (DVFB) with enhanced adaptive feed-forward cancellation (AFC). AFC is known as an adaptive control method, and the adaptive algorithm can estimate a periodic disturbance. In a previous study, an enhanced AFC was developed to compensate for a non-periodic disturbance. An active vibration control based on self-sensing by DVFB can suppress mechanical resonance by using relative velocity between the voice coil actuator and a target structure. In this study, the enhanced AFC was applied to compensate disturbance for the self-sensing vibration control system. The simulation results showed the vibration control system with DVFB and enhanced AFC could suppress mechanical resonance and compensate disturbances.

Author(s):  
Lawrence R. Corr ◽  
William W. Clark

Abstract This paper presents a numerical study in which active and hybrid vibration confinement is compared with a conventional active vibration control method. Vibration confinement is a vibration control technique that is based on reshaping structural modes to produce “quiet areas” in a structure as opposed to adding damping as in conventional active or passive methods. In this paper, active and hybrid confinement is achieved in a flexible beam with two pairs of piezoelectric actuators and sensors and with two vibration absorbers. For comparison purposes, active damping is achieved also with two pairs of piezoelectric actuators and sensors using direct velocity feedback. The results show that both approaches are effective in controlling vibrations in the targeted area of the beam, with direct velocity feedback being slightly more cost effective in terms of required power. When combined with passive confinement, however, each method is improved with a significant reduction in required power.


2005 ◽  
Vol 24 (3) ◽  
pp. 181-190 ◽  
Author(s):  
Yun-Hui Liu

This paper proposes the application of a proportional controller to active vibration control incorporated with a passive vibration isolator to suppress its resonant oscillation at its natural frequency. Vibration acceleration acquired from an accelerometer is fed to the controller as a feedback signal. The processed signal from the controller is transmitted to the voice coil actuator in order to control the vibration. Firstly, based on the theoretical equations which govern the vibrational system, the physical mechanism of active control in the total system is studied. Then, vibration on a stiff foundation and passive isolator is measured in order to understand the efficiency of the traditional vibration control method. Finally, an experiment on active vibration control is performed to study the suppression efficiency of the oscillation of the passive vibration isolator. The experiment results show that 99% of the vibration energy can be cancelled by active control.


2013 ◽  
Vol 198 ◽  
pp. 433-438
Author(s):  
Andrzej Piotr Koszewnik

Mechanical structures are spatial, three-dimensional (3D) systems of distributed parameters. They present quite complicated plants, if methods of control systems theory are applied. The design process of the vibration control system for such plants is extremely difficult and requires an extensive heuristic knowledge. The subject of the control system is to eliminate the vibrations of the free end at the plane parallel to the foundation Similar problems are met, when the stabilization of robot arms, antennas, satellite solar batteries or slender skyscrapers is considered. In the paper we have presented the 3D bar structure with sticked parallel two piezo-stacks into bars. Recall piezo-elements are actuators, but sensors are two eddy-current sensors located in near free end the structure in perpendicular directions X and Y. Thus the whole structure is TITO (Two Input Two Output) system. For such system the control law was designed with used LQR controller. Above controller was designed for coupled and decoupled system also. In both case a correct damp and very short period of the vibration were criteria to choose the controller parameters. All investigations were carried out in two steps. In the first step control laws were designed in computer simulation. In the second step these control laws were verified experimentally on the laboratory stand by using DSP. Finally, desired control laws were compared.


2015 ◽  
Vol 07 (04) ◽  
pp. 1550066 ◽  
Author(s):  
Zengyong An ◽  
Minglong Xu ◽  
Yajun Luo ◽  
Chengsong Wu

Large annular flexible structures (LAFS) are typical antenna structures for satellites. This structure can significantly increase antenna aperture and effectively improve communication accuracy with minimum addition of mass. LAFS have become mainstream for large aperture antenna structures. However, they have disadvantages, such as low natural frequencies, low damping ratio, and low stiffness. They easily suffer from low frequency, longtime and modal responses. Therefore, the vibration control of LAFS is very important. This study proposes a novel active vibration control method using macro-fiber composite (MFC) as a sensing unit, a voice coil actuator and a PD-fuzzy control algorithm. The MFC sensor can measure a minimum strain of 10-8 m/m. The voice coil actuator generates a displacement and driving force. Based on the feedback signal from the MFC sensor, the PD-fuzzy control algorithm controls the voice coil actuator. A dynamic model of LAFS was established, and its characteristics analyzed. A theoretical model for the voice coil actuator and MFC sensor were established, and the corresponding governing equations derived. An experimental system was set up. The results demonstrated that the novel active vibration control method has good performance. This active vibration control method can control vibration at ultralow frequencies and requires no additional stiffness.


2021 ◽  
Author(s):  
Yong Xia

Vibration control strategies strive to reduce the effect of harmful vibrations such as machining chatter. In general, these strategies are classified as passive or active. While passive vibration control techniques are generally less complex, there is a limit to their effectiveness. Active vibration control strategies, which work by providing an additional energy supply to vibration systems, on the other hand, require more complex algorithms but can be very effective. In this work, a novel artificial neural network-based active vibration control system has been developed. The developed system can detect the sinusoidal vibration component with the highest power and suppress it in one control cycle, and in subsequent cycles, sinusoidal signals with the next highest power will be suppressed. With artificial neural networks trained to cover enough frequency and amplitude ranges, most of the original vibration can be suppressed. The efficiency of the proposed methodology has been verified experimentally in the vibration control of a cantilever beam. Artificial neural networks can be trained automatically for updated time delays in the system when necessary. Experimental results show that the developed active vibration control system is real time, adaptable, robust, effective and easy to be implemented. Finally, an experimental setup of chatter suppression for a lathe has been successfully implemented, and the successful techniques used in the previous artificial neural network-based active vibration control system have been utilized for active chatter suppression in turning.


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