Active control of payload fairing noise using distributed active vibration absorbers

2003 ◽  
Vol 113 (4) ◽  
pp. 2251-2251
Author(s):  
Arnaud Charpentier ◽  
Marty E. Johnson ◽  
Chris R. Fuller
Keyword(s):  
Active Control ◽  
Vibration Absorbers ◽  
Active Vibration ◽  
Payload Fairing

Frequency Shaped Semi-Active Control for Magnetorheological Fluid-Based Vibration Control Systems

2013 ◽  
Author(s):  
Young-Tai Choi ◽  
Norman M. Wereley ◽  
Gregory J. Hiemenz
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Control ◽  
Control Algorithm ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Model Parameters ◽  
Mr Fluid ◽  
Control Current ◽  
Active Vibration

Novel semi-active vibration controllers are developed in this study for magnetorheological (MR) fluid-based vibration control systems, including: (1) a band-pass frequency shaped semi-active control algorithm, (2) a narrow-band frequency shaped semi-active control algorithm. These semi-active vibration control algorithms designed without resorting to the implementation of an active vibration control algorithms upon which is superposed the energy dissipation constraint. These new Frequency Shaped Semi-active Control (FSSC) algorithms require neither an accurate damper (or actuator) model, nor system identification of damper model parameters for determining control current input. In the design procedure for the FSSC algorithms, the semi-active MR damper is not treated as an active force producing actuator, but rather is treated in the design process as a semi-active dissipative device. The control signal from the FSSC algorithms is a control current, and not a control force as is typically done for active controllers. In this study, two FSSC algorithms are formulated and performance of each is assessed via simulation. Performance of the FSSC vibration controllers is evaluated using a single-degree-of-freedom (DOF) MR fluid-based engine mount system. To better understand the control characteristics and advantages of the two FSSC algorithms, the vibration mitigation performance of a semi-active skyhook control algorithm, which is the classical semi-active controller used in base excitation problems, is compared to the two FSSC algorithms.

Payload noise suppression using distributed active vibration absorbers

2002 ◽  
Author(s):  
Stephen D. O'Regan ◽  
Bart Burkewitz ◽  
Christopher Fuller ◽  
Steven A. Lane ◽  
Marty Johnson
Keyword(s):  
Noise Suppression ◽  
Vibration Absorbers ◽  
Active Vibration

scholarly journals Damping in magnetorheological elastomers under compressive stress

2019 ◽  
Vol 254 ◽  
pp. 06002 ◽  
Author(s):  
Mateusz Kukla ◽  
Krzysztof Talaśka ◽  
Ireneusz Malujda
Keyword(s):  
Smart Materials ◽  
Hysteresis Loops ◽  
Machine Construction ◽  
Vibration Absorbers ◽  
Magnetorheological Elastomers ◽  
Practical Applications ◽  
Mechanical Hysteresis ◽  
Compressive Stresses ◽  
Active Vibration ◽  
Energy Absorbers

Magnetorheological elastomers are an important area of study in non-classical engineering materials. These are smart materials, in which some of the physical properties are dependent on the applied magnetic field. This unique property allows to suggest new, innovative practical applications. It is therefore relevant to carry out studies in the possible application of magnetorheological elastomers in machine construction. The present article presents the results of study regarding the properties of the discussed materials subject to compressive stresses. Particular attention is given to the observed growth of surface area of mechanical hysteresis loops, which is evidence of the possibility to change the damping properties of magnetorheological elastomers. This property can be utilized in the construction of different types of machines and devices. These mostly applies to energy absorbers such as active vibration absorbers.

Active Control Algorithms for the Control of Rotor Vibrations Using HSFDs

2000 ◽  
Author(s):  
A. El-Shafei
Keyword(s):  
Active Control ◽  
Gain Scheduling ◽  
Rotating Machinery ◽  
Squeeze Film ◽  
Control Algorithms ◽  
Critical Stage ◽  
Squeeze Film Damper ◽  
Active Vibration

The Hybrid Squeeze Film Damper (HSFD) has proven itself to be an effective controlling device of vibration in rotating machinery. The critical stage in the development of the HSFD as an active vibration suppressant, is the development of the control algorithms for active control of rotor vibrations. This paper summarizes, evaluates and compares the control algorithms for HSFD supported rotors. Quantitative as well as qualitative measures of the effectiveness of the control algorithms are presented. The study includes the PID-type controllers, LQR, gain scheduling, adaptive and bang-bang controllers. The adaptive, gain scheduling and nonlinear proportional controllers, have proved to be quite effective in the active control of HSFD supported rotors, with impressive results.

Verification of the Relation Between the Directions of Control Force and Responses in Active Seismic Isolation Device

2018 ◽  
Author(s):  
Keigo Nakamura ◽  
Nanako Miura ◽  
Akira Sone
Keyword(s):  
Active Control ◽  
Seismic Isolation ◽  
Seismic Waves ◽  
Base Isolation ◽  
Active Vibration Control ◽  
Control Force ◽  
Control Power ◽  
Active Vibration ◽  
Self Powered ◽  
Isolation Device

In this research, the focus is on the energy problem in active vibration control of a seismic isolation device using self-powered active control that regenerates electric power from kinetic energy of vibration system and uses it as control power. In recent years, it is proposed to install semi-active control or active control in an isolated structure to deal with seismic waves of various periods. However, since energy is required for control, there is a problem that the desired response reduction performance cannot be achieved when energy supply is interrupted at the time of a power outage. In our previous device, power is always given to the motor to control, thus power consumption is high. Therefore, the purpose of this research is to propose input method of control force that can reduce control power while keeping base isolation performance by classifying the role of the control force for each control phase and considering various combinations of input control force.

scholarly journals Active vibration isolation of high precision machines

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
C. Collette ◽  
S. Janssens ◽  
K. Artoos ◽  
C. Hauviller
Keyword(s):  
Active Control ◽  
High Precision ◽  
Vibration Isolation ◽  
Control Strategies ◽  
External Disturbances ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
Atomic Force ◽  
Active Vibration ◽  
Precision Machines

This paper provides a review of active control strategies used to isolate high-precisionmachines (e.g. telescopes, particle colliders, interferometers, lithography machines or atomic force microscopes) from external disturbances. The objective of this review is to provide tools to develop the best strategy for a given application. Firstly, the main strategies are presented and compared, using single degree of freedom models. Secondly, the case of huge structures constituted of a large number of elements, like particle colliders or segmented telescopes, is considered.

The Design and Application of Piezoelectric Friction Damper with Self-Powered and Sensing Control System

2010 ◽  
Vol 163-167 ◽  
pp. 2477-2481
Author(s):  
Na Xin Dai ◽  
Ping Tan ◽  
Fu Lin Zhou
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Active Control ◽  
Mechanical Energy ◽  
Active Vibration Control ◽  
Friction Damper ◽  
Active Vibration ◽  
Self Powered ◽  
Control Equation ◽  
Converse Piezoelectric Effect

To make the active and semi-active vibration control system in civil engineering get rid of external power supply, a new piezoelectric friction damper with self-power and sensing is designed in this paper and a semi-active control system based on this damper is presented. This system includes three key parts: a piezoelectric friction damper, a power generator based on the piezoelectric stack electro-mechanical energy conversion and a control circuit. It makes full use of the direct and converse piezoelectric effect. At the same time, it also overcomes the deficiency that the frictional force as damping can not be accurately desired in semi-active vibration control system. On the basis of it, the control equation of PFD is formulated. Numerical simulations for seismic protection of story isolation equipped with this system excited by a historical earthquake are conducted by MATLAB. Skyhook control is used to command a piezoelectric friction damper in the semi-active control. It is noticed that only one accelerometer is needed to monitor the response to realize the skyhook control, which greatly simplifies the classical semi-active vibration control system.

Bridge Life Extension Using Semi-Active Vibration Control

2013 ◽  
Author(s):  
G. Nelson ◽  
R. Rajamani ◽  
A. Gastineau ◽  
A. Schultz ◽  
S. Wojtkiewicz
Keyword(s):  
Control System ◽  
Resonant Frequency ◽  
Vibration Control ◽  
Active Control ◽  
Active Vibration Control ◽  
Life Extension ◽  
Peak Strain ◽  
Steel Bridge ◽  
Active Vibration ◽  
Active Control System

The fatigue life of a bridge can be extended by fifty years just by reducing the peak strain levels it experiences by 33%. This paper utilizes a dynamic model of the Cedar Avenue tied arch steel bridge in Minnesota to investigate active control technologies for peak strain reduction. Simulations show that the use of passive structural modification devices such as stiffeners and dampers is inadequate to reduce the key resonant peaks in the frequency response of the bridge. Both active and semi-active vibration control strategies are then pursued. Active vibration control can effectively reduce all resonant peaks of interest, but is practically difficult to implement on a bridge due to power, size, and cost considerations. Semi-active control with a variable orifice damper in which the damping coefficient is changed in real-time using bridge vibration feedback can be practically implemented. Simulation results show that the proposed semi-active control system can reduce many of the resonant peaks of interest, but is unable to reduce the response at one key resonant frequency. Further analysis reveals that the location of the actuator on the bridge chosen for the semi-active controller is inappropriate for controlling the specific resonant frequency of issue. By modifying the actuator location, it would be possible to obtain control of all bridge resonant frequencies with the semi-active control system.

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