Finite Frequency Robust Vibration Control of Flexible-Rigid Coupled Spacecraft

2020 ◽  
Author(s):  
Shidong Xu
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Vibration Modes ◽  
Frequency Range ◽  
Finite Frequency ◽  
Frequency Constraint ◽  
Vibration Attenuation ◽  
Specific Frequency ◽  
Vibration Attenuation Performance ◽  
Frequency Controller

Abstract This paper is concerned with robust vibration control of flexible-rigid coupling spacecraft with finite frequency constraint. Considering that the major vibration energy of flexible structure is induced by the vibration modes located in a specific frequency range, the dynamics of the considered spacecraft are derived as a system with given vibration modes. A novel robust finite frequency controller is proposed by using output feedback method, which focuses on suppressing the vibration modes in given frequency region. Compared with the classic entire frequency controller, the newly proposed controller can achieve better vibration attenuation performance. Finally, illustrative simulation results are provided to demonstrate the effectiveness and superiority of our proposed control method.

Reduction of Whole Body Vibration in a Wide Frequency Range Using Inflation Pressure Control of Air Bladder Cushion

2021 ◽  
Author(s):  
Pavan Nuthi ◽  
Yixin Gu ◽  
Aida Nasirian ◽  
Alexandra Lindsay ◽  
Himanshu Purandare ◽  
...  
Keyword(s):  
Whole Body Vibration ◽  
Wide Frequency Range ◽  
Whole Body ◽  
Frequency Range ◽  
Inflation Pressure ◽  
Cell Array ◽  
Frequency Sweep ◽  
Body Vibration ◽  
Vibration Attenuation ◽  
Vibration Attenuation Performance

Abstract Several types of interfaces like foam and inflated air cells exist to reduce the effect of mechanical vibration experienced in human-machine interfaces in different scenarios such as transportation. However, their vibration attenuation performance in a wide frequency range relevant to whole body vibration (1–80 Hz) leaves much to be desired. In this study, we investigate the effect of inflation pressure on the vibration attenuation behavior of an air cell cushion. An experimental setup capable of conducting frequency sweep tests and regulating inflation pressure in an air cell array cushion was developed. Frequency sweep tests were conducted at various inflations and the vibration transmissibilities at static inflations were plotted. A dynamic inflation scheme was developed based on the apriori knowledge of inflation dependent transmissibilities. Furthermore, the closed loop behavior of the inflation scheme was evaluated with a frequency sweep test. The resulting closed loop transmissibility indicated better vibration attenuation performance than any single static inflation for the air cell array cushion in the range of frequencies relevant to whole body vibration. This result lays the groundwork for potential air cell cushions which modify their inflation dynamically through a direct feedback from sensors like accelerometers to attenuate vibration in a wide frequency range.

Motion and Vibration Control of a Flexible Transportation System

2003 ◽  
Author(s):  
Keisuke Takemoto ◽  
Masato Mori ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Transportation System ◽  
Modeling Method ◽  
Vibration Modes ◽  
Simulation Experiments ◽  
Reduced Order ◽  
Control Effectiveness ◽  
Modeling Approach ◽  
And Control

This paper shows a lumped modeling approach and a motion and vibration control method for a transportation system. The modeling approach is made on the premise that motion influences vibration, but that vibration doesn’t influence motion. To obtain well suppressed vibration and a robustness for the system, LQI control is adopted. It is shown that this theory has superior robustness for in motion and vibration control with variations of the parameters [1]. The control effectiveness is demonstrated through simulation experiments. The vibration modes that occur accordingly become flexible might cause a spillover instability problem. Thus, the purpose of the research is to control such vibration and motion using the modeling method presented by Seto, called the “reduced order physical modeling method” [2]. Computer simulation and control experiments are carried out and the effectiveness of the procedures presented is investigated.

An improved multi-mode seismic vibration control method using multiple tuned mass dampers

2022 ◽  
pp. 136943322110509
Author(s):  
Xuan Zhang ◽  
Qiang Han ◽  
Kaiming Bi ◽  
Xiuli Du
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Numerical Study ◽  
Ground Motions ◽  
Vibration Modes ◽  
Tuned Mass Dampers ◽  
Location Factor ◽  
Mass Damper ◽  
Multi Mode ◽  
Multiple Tuned Mass Dampers

Multiple vibration modes of an engineering structure might be excited by earthquake ground motions. Multiple tuned mass dampers (MTMDs) are widely used to control these multi-mode vibrations. However, in the commonly used MTMD system, the mass element in each tuned mass damper (TMD) is normally assumed to be the same. To improve the performance of MTMDs for seismic-induced vibration control, non-uniform MTMD masses are adopted in the present study to improve the mass utilization of TMD, and a location factor is proposed to determine the best location of each TMD in the MTMD system. The effectiveness of the proposed method is validated through numerical study. The results show that the proposed method effectively reduces the seismic responses of the structure induced by multiple vibration modes.

Thermodynamic Variational Formulations of Subordinate Oscillator Arrays (SOA) With Linear Piezoelectrics

2017 ◽  
Author(s):  
Sai Tej Paruchuri ◽  
Andrew J. Kurdila ◽  
John Sterling ◽  
Amelia Vignola ◽  
John Judge ◽  
...  
Keyword(s):  
Vibration Suppression ◽  
Vibration Isolator ◽  
Frequency Range ◽  
Finite Frequency ◽  
Effects Of Disorder ◽  
Vibration Attenuation ◽  
Oscillator Arrays ◽  
Classical Vibration ◽  
Two Degree Of Freedom ◽  
Variational Formulations

It has been shown theoretically that by prescribing the mass and stiffness distributions of a subordinate oscillator array (SOA) that is attached to a host structure, significant vibration attenuation of a host can be obtained over a finite frequency range. This case stands in stark contrast to classical vibration isolator designs for two degree of freedom systems that achieve exact vibration cancellation at a single isolated frequency. Despite the attractiveness of SOAs for the design of broader band vibration suppression, the theoretically desired result can deteriorate rapidly due to small fabrication imperfections in the SOA. This paper introduces and compares variational thermodynamic formulations of composite piezoelectric SOA that are designed to be adjustable in real-time to ameliorate the effects of disorder due to fabrication in a SOA.

Study on Construction Blasting Vibration Control and Effect of Space Coupling of the Large Cavern under High Crustal Stress

2011 ◽  
Vol 368-373 ◽  
pp. 2908-2914
Author(s):  
Sheng Xiang Lei ◽  
Bo Gao
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Field Trials ◽  
Blasting Vibration ◽  
Underground Structures ◽  
Crustal Stress ◽  
Construction Methods ◽  
Geological Conditions ◽  
Vibration Attenuation ◽  
The Impact

Taken extremely complex and specific underground chamber excavation of TBM assembly in Jinping Ⅱ Hydropower Station as the background, the research was done on construction blasting vibration effects and control technology in the large cavern under high crustal stress. Combined theoretical analysis with field trials and other methods, chamber controlled blasting program and its parameters of better control of blasting vibrations were set in regard with the geological conditions of TBM assembly chamber, cross-section shape and size, chamber body structure and sequence of construction methods. The blasting vibration test program under complex conditions and measuring points were arranged appropriately. The result is that the blasting vibration attenuation coefficient values and was 1.24 and 0.56. Practice shows that the impact of blasting vibration on rock and underground structures is lesser, therefore the chamber driving speed and construction safety can be ensured by the chamber controlled blasting technology for construction. The blasting vibration attenuation that is deduced from the practice can better reflect the effect of blasting vibration chamber: according to the correlation between dose and level distance of blasting, safe construction blasting can be guided. In addition, there is a greater relevance between blasting vibration control method, materials and strength of underground structures. As blasting dose is the same, with increased age and strength of concrete, its ability to withstand the intensity of blasting vibration is also increased dramatically.

Vibration Control of Beams with Negative Capacitive Shunting of Interdigital Electrode Piezoceramics

2005 ◽  
Vol 11 (3) ◽  
pp. 331-346 ◽  
Author(s):  
Chul H. Park ◽  
Amr Baz
Keyword(s):  
Mathematical Model ◽  
Boundary Conditions ◽  
Vibration Control ◽  
Equations Of Motion ◽  
Vibration Modes ◽  
Frequency Range ◽  
Governing Equations ◽  
Interdigital Electrode ◽  
Beam System ◽  
Cantilevered Beam

A pair of interdigital electrode (IDE) piezoceramics is used to simultaneously suppress multimode vibrations of a cantilevered beam. This is achieved by connecting the IDE piezoceramics in parallel to a negative capacitive shunt circuit. The governing equations of motion of an IDE piezo/beam system and associated boundary conditions are derived using the Hamilton principle. The obtained mathematical model is validated experimentally Attenuations ranging between 5 and 20 dB are obtained for all the vibration modes over the frequency range of 0-3000 Hz. The presented theoretical and experimental techniques provide invaluable tools for designing simple and effective passive vibration dampers for structures with closely packed modes.

Vibration Control Method and Adaptability for Flexible Structures With Distributed Parameters Using a Hybrid Dynamic Absorber

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Susumu Kondo ◽  
Katsuhiko Ezure
Keyword(s):  
Vibration Control ◽  
Control Method ◽  
Controller Design ◽  
Flexible Structures ◽  
Vibration Modes ◽  
Order Model ◽  
Reduced Order ◽  
Distributed Parameters ◽  
Dynamic Absorber ◽  
Lq Control

Abstract This paper examines the vibration control of a flexible structure using a hybrid dynamic absorber. A new method for modeling flexible structures with distributed parameters using a reduced-order model with lumped parameters is specified. Both prevention of spillover and physical correspondence at the modeling points are taken into consideration. Due to restrictions of controller design it is necessary to employ reduced-order models of flexible structures when using LQ control theory to control vibration. By ignoring higher mode orders model reduction may invite vibration instability called spillover. In order to prevent spillover nodes of higher-order vibration modes are selected as modeling points. The effectiveness of this method is demonstrated by applying vibration control to a flexible tower-like structure. In addition the robustness of the control system is tested by placing the sensors and absorbers at points different from those selected by the model.

Wave-based active vibration control of a membrane structure

2021 ◽  
pp. 107754632110429
Author(s):  
Xiang Liu ◽  
Liangliang Lv ◽  
Fujun Peng ◽  
Guoping Cai
Keyword(s):  
Vibration Control ◽  
Membrane Structure ◽  
Control Method ◽  
Active Vibration Control ◽  
Standing Waves ◽  
Vibration Modes ◽  
Control Laws ◽  
Reflected Waves ◽  
Active Vibration ◽  
Active Wave

Wave-based active vibration control of a membrane structure by using the Active Sink Method is studied in this paper. Unlike the modal-based vibration control method which attempts to suppress several vibration modes that have already been excited, wave-based active controller can keep vibration modes inactive by stopping the formation of standing waves in the structure. First, the wave transfer matrix is deduced to characterize the wave transmission in the membrane structure. Then, feedforward wave control laws are derived analytically to absorb reflected waves or eliminate transmitted waves. The validity of the proposed active wave controllers is verified through numerical simulations. Simulation results show that by using the active wave controllers no standing waves will be produced in the structure, and the vibration of the membrane structure is suppressed significantly.

scholarly journals Magnetic Nonlinear Energy Sink for Vibration Attenuation of Unbalanced Rotor System

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Hongliang Yao ◽  
Dasheng Zheng ◽  
Bangchun Wen
Keyword(s):  
Averaging Method ◽  
Nonlinear Energy Sink ◽  
Rotor System ◽  
Frequency Range ◽  
Runge Kutta Method ◽  
Unbalanced Rotor ◽  
Vibration Attenuation ◽  
Energy Sink ◽  
Vibration Attenuation Performance ◽  
Nonlinear Energy

A novel nonlinear energy sink (NES) consisting of permanent magnetic springs and coil springs is proposed, and the vibration attenuation performance of the NES for unbalanced rotor system is investigated. Firstly, the nonlinearity of the magnet spring is analyzed and the structure of the NES is introduced. Then, the dynamic model of the rotor system with the NES is built, and the responses and stabilities of the system are studied by applying Complexification-averaging method. The strongly modulated responses (SMR) behavior, which is the most important performance characteristic of the NES, is analytically studied by combining Complexification-averaging method and multiscale method and numerically verified by Runge-Kutta method. The results show that the NES is effective in attenuating the vibration of unbalanced rotor, and the SMR occurrence range can be broadened by increasing the nonlinearity of the NES. And also, the NES has better performance over a wider frequency range than the linear absorber.

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