scholarly journals Ultra-low frequency active vibration control for cold atom gravimeter based on sliding-mode robust algorithm

2018 ◽  
Vol 67 (2) ◽  
pp. 020702
Author(s):  
Luo Dong-Yun ◽  
Cheng Bing ◽  
Zhou Yin ◽  
Wu Bin ◽  
Wang Xiao-Long ◽  
...  
Author(s):  
Kazuto Seto ◽  
Yoshihiro Toba ◽  
Fumio Doi

Abstract In order to realize living comfort of tall buildings by reducing the vibration of higher floors by strong winds, this paper proposes a new method of vibration control for flexible structures with a large scale. The higher a tall building the lower its natural frequency. Since obtaining sufficient force to control the lower frequency vibrations of tall buildings is a difficult task, controlling the vibration of ultra-tall buildings using active dynamic absorbers is nearly impossible. This problem can be overcome by placing actuators between a pair of two or three ultra-tall buildings and using the vibrational force of each building to offset the vibrational movement of its paired mate. Therefore, it is able to obtain enough control force under the low frequency when the proposed method is used. In this paper, a reduced-order model expressed by 2DOF system under taking into consideration for preventing spillover instability is applied to control each flexible structure. The LQ control theory is applied to the design of such a control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.


2019 ◽  
Vol 9 (16) ◽  
pp. 3326 ◽  
Author(s):  
Zhao ◽  
Wang

As a major device for reducing vibration and protecting passengers, the low-frequency vibration control performance of commercial vehicle seating systems has become an attractive research topic in recent years. This article reviews the recent developments in active seat suspensions for vehicles. The features of active seat suspension actuators and the related control algorithms are described and discussed in detail. In addition, the vibration control and reduction performance of active seat suspension systems are also reviewed. The article also discusses the prospects of the application of machine learning, including artificial neural network (ANN) control algorithms, in the development of active seat suspension systems for vibration control.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yi Yu ◽  
Xing Shen ◽  
Yun Huang

In wind tunnel tests, the cantilever sting is usually used to support aircraft models because of its simple structure and low aerodynamic interference. However, in some special conditions, big-amplitude and low-frequency vibration would occur easily on the model not only in the pitch direction but also in the yaw direction, resulting in inaccurate data and even damage of the supporting structure. In this paper, aiming at suppressing the vibration in pitch and yaw plane, a multidimensional system identification and active vibration control system on the basis of piezoelectric actuators is established. A vibration monitoring method based on the strain-displacement transformation (SDT) matrix is proposed, which can transform strain signals into vibration displacements. The system identification based on chirp-Z transform (CZT) is applied to improve the adaptability and precision of the building process for the system model. After that, the hardware platform as well as the software control system based on the classical proportional-derivative (PD) algorithm is built. A series of experiments are carried out, and the results show the exactness of the vibration monitoring method. The system identification process is completed, and the controller is designed. Vibration control experiments verify the effectiveness of the controller, and the results indicate that vibrations in pitch and yaw directions are attenuated apparently. The spectrum power is reduced over 14.8 dB/Hz, which prove that the multidimensional identification and active vibration control system has the capability to decline vibration from different directions.


Author(s):  
H-J Kim

This paper presents an active vibration control (AVC) system for trailed two-wheeled implements (TTWI) equipped with high precision electronic devices. With the aim of isolating disturbance forces to the devices, a hydraulically actuated vibration control system is devised. In order to suppress vibratory motions to the body components, considering the TTWI system characteristics, a vibration control and a force tracking control strategy is adopted. As the vibration controller, the adaptive and skyhook control schemes are applied. From full order and reduced order model for the actuating module, as the tracking controller, the sliding mode control scheme is adopted regarding parameter variations. On the basis of the roll plane TTWI system model, simulation work is performed. Finally, after implementation of the experimental setup with the TTWI system and the road simulating module considering practical requirements, actual performance of the devised AVC system is evaluated in various disturbance conditions.


2011 ◽  
Vol 52-54 ◽  
pp. 358-364
Author(s):  
Jong Seok Oh ◽  
Seung Bok Choi

In this paper, vibration control performance of piezostack active engine mount system for unmanned aero vehicle (UAV) is evaluated via computer simulation. As a first step, the dynamic model of engine mount system which is supported at three points is derived. In the configuration of engine mount system, the inertia type of piezostack based active mount is installed for active vibration control. Then, the vibration level of UAV engine is measured. To attenuate the vibration which is transmitted from engine, a sliding mode controller which is robust to uncertain parameters is designed. Vibration control performances of active engine mount system are evaluated at each mount and center of gravity. Effective Control results are presented in both time and frequency domains.


2021 ◽  
Author(s):  
Mehmet Ali GUVENC ◽  
Hasan Huseyin BILGIC ◽  
Selçuk MISTIKOĞLU

Abstract In recent years, with the development of sensor technologies, communication platforms, cyber physical systems, storage technologies, internet applications and controller infrastructures, the way has been opened to produce competitive products with high quality and low cost. In turning, which is one of the important processes of machining, chatter vibrations are among the biggest problems affecting product quality, productivity and cost. There are many techniques proposed to reduce chatter vibrations for which the exact cause cannot be determined. In this study, an active vibration control based on Sliding Mode Control (SMC) has been implemented in order to reduce and eliminate chatter vibration, which is undesirable for the turning process. In this context, three-axis acceleration data were collected from the cutting tool during the turning of Ti6Al4V. Finite Impulse Response (FIR) filtering, Fast Fourier Transform (FFT) analysis and integral process were carried out in order to use the raw acceleration data collected over the system in control. The system was modeled mathematically and an active control block diagram was created. It was observed that chattering decreased significantly after the application of active vibration control. The surface quality formed by the amplitude of the graph obtained after active control has been compared and verified with the data obtained from the actual manufacturing result.


2019 ◽  
Vol 9 (15) ◽  
pp. 3188 ◽  
Author(s):  
Xiyue Ma ◽  
Lei Wang ◽  
Jian Xu

Active control of low frequency vibration and sound radiation from a rib stiffened plate has great practical significance as this structure is widely applied in engineering, such as aircraft or ship fuselage shells. This paper presents an investigation on the performance of active vibration control of the rib stiffened plate by using decentralized velocity feedback controllers with inertial actuators. A simple modeling approach in frequency domain is proposed in this research to calculate the control performance. The theoretical model of vibrating response of the ribbed plate and the velocity feedback controllers is first established. Then, as an important part, the influences of the control gain and the number of the decentralized unit on the control performance are investigated. Results obtained demonstrate that—similar to that of the unribbed plate case—appropriately choosing the number of the unit and their feedback gains can achieve good control results. Too many units or very high feedback gains will not bring further noise reduction.


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