Performance analysis of active control systems based on the source-sink flow relationship of the structural intensity

2021 ◽  
Vol 69 (2) ◽  
pp. 122-135
Author(s):  
J.M. Ku ◽  
J.W. Lee ◽  
W.B. Jeong ◽  
C. Hong
Keyword(s):  
Active Vibration Control ◽  
Feedback System ◽  
Destructive Interference ◽  
Control Force ◽  
Structural Intensity ◽  
Active Vibration ◽  
Feedforward Controller ◽  
Source Sink ◽  
And Control ◽  
Relationship Of

The mechanisms of feedforward and feedback methods were analyzed for active vibration control. A feedforward controller was designed in the frequency domain using optimal control theory. The feedback control uses the direct velocity feedback method. The two control methods were applied to a plate, and the mechanisms were analyzed by examining the structural intensity map. In the case of the feedback system, the disturbance acting on the structure serves as a source, and the control force acts as a sink to reduce the vibration energy of the structure. On the other hand, in the feedforward system, the energy is reduced by the destructive interference of the intensity generated by the disturbance and control force. In this case, when analyzing the vibration intensity of the structure, component by component, the intensity generated by the control force is interfered with mainly the mutual power terms. They are the product of the force due to disturbance and the velocity due to control force, vice versa. Based on this analysis under the source-sink relationship of the feedback system, we confirmed that a higher control performance can be obtained by the control force at a point where the structural intensity is in a more easily flow position.

Active Vibration Control of a Triple Flexible Structures Combined With Actuators

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Yoshihiro Toba ◽  
Fumio Doi
Keyword(s):  
Vibration Control ◽  
Large Scale ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Low Frequency ◽  
Tall Buildings ◽  
Control Force ◽  
Active Vibration ◽  
Strong Winds ◽  
Lq Control

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.

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.

Modeling Rate-Dependent Hysteresis for GMA Using Online Least Squares Support Vector Machines

2011 ◽  
Vol 48-49 ◽  
pp. 710-714
Author(s):  
Zhen Kai Guo ◽  
Zhao Qing Song ◽  
Xin Jiang Wei
Keyword(s):  
Support Vector Machines ◽  
Least Squares ◽  
Active Vibration Control ◽  
Support Vector ◽  
Nonlinear Phenomenon ◽  
Rate Dependent ◽  
Hysteresis Nonlinearity ◽  
Vector Machines ◽  
Active Vibration ◽  
And Control

Rate-dependent hysteresis is a strongly nonlinear phenomenon which exists in the giant magnetostrictive actuator (GMA); it has influence in the precision and stability of active vibration control. It is highly important in the control theory and control engineering that the influence of hysteresis is eliminated by the modeling of rate-dependent hysteresis for GMA. So an online intelligent modeling method, which is based on an improved online least squares support vector machines (IOLS-SVM), is presented for identifying rate-dependent hysteresis nonlinearity for GMA, and is used to online real-time training. The data measured in the experiment are used for modeling. The numerical simulation shows the effectiveness of the method.

scholarly journals A Comparative Study Based on Different Control Algorithms for Suppressing Multistage Gear Transmission System Vibrations

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Wenhao Sun ◽  
Feng Zhang ◽  
Weidong Zhu ◽  
Han Wang ◽  
Shunan Luo ◽  
...  
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Transmission System ◽  
Gear Transmission ◽  
Control Algorithms ◽  
Control Force ◽  
The Finite Element Method ◽  
Control Schemes ◽  
Gear Transmission System ◽  
Active Vibration

A modal analysis (MA) was preconsidered to determine a novel active vibration control (AVC) structure of multistage gear transmission system (MGTS) and an appropriate actuating position for the piezoelectric actuator (PZT); the results of the calculating method and the finite element method (FEM) were compared to validate the reliability of MA. The controllers based on different control algorithms were designed to drive the PZTs to output the control force for suppressing the host structure vibrations. To analyze the feasibility of the applied control schemes and discuss the control effects dominated by the different control algorithms, a series of active vibration control numerical simulations were studied. The cosimulation results validate the practicability of the proposed control schemes and provide a forcible guidance for the further experimental works.

Distributed Actuation Effectiveness of Flexible Parabolic Cylindrical Panels

2012 ◽  
Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou
Keyword(s):  
Active Vibration Control ◽  
Cylindrical Panel ◽  
Modal Control ◽  
Control Force ◽  
Control Effect ◽  
Control Effectiveness ◽  
Cylindrical Panels ◽  
Total Control ◽  
Shell Panel ◽  
Active Vibration

Open parabolic cylindrical panel plays a key role in radial collection and transmission applied to radar antennas, space reflectors, solar collectors, etc. Piezoelectric active vibration control can suppress unexpected fluctuation and maintain precision surface and operations. This study aims to investigate the distributed actuation behavior of adaptive open parabolic cylindrical panels using piezoelectric actuator patches. Motion equations of parabolic cylindrical panels laminated with a piezoelectric patch is presented first. Then, the actuator induced modal control force is derived with an assumed mode shape function. As the area of actuator patch varies due to the curvature change, the normalized actuation effectiveness (i.e., modal control force divided by actuator area) is further evaluated. When the actuator area shrinks to infinitesimal, the expression of microscopic point modal control force is obtained to theoretically predict the actuation distribution behavior. The actuation behaviors of the total control force and its components exhibit distinct characteristics with respect to shell geometries, modes and actuator properties. Analyses show that the control force component contributed by the membrane force dominates the total control effect. The bending-contributed component increases with corresponding vibration mode number, while the membrane-contributed component decreases. Three shell geometries from shallow to deep are evaluated in case studies. Analysis of optimal actuator location shows that actuators are preferred to locate where the curvature of shell panel is larger in order to maximize the control effectiveness.

Active Vibration Control of the Axially Moving String Using Space Feedforward and Feedback Controllers

1996 ◽  
Vol 118 (3) ◽  
pp. 306-312 ◽  
Author(s):  
S. Ying ◽  
C. A. Tan
Keyword(s):  
Vibration Control ◽  
Feedforward Control ◽  
Active Vibration Control ◽  
Upstream Region ◽  
Control Force ◽  
Feedback Controllers ◽  
Axially Moving String ◽  
Downstream Region ◽  
Active Vibration ◽  
Axially Moving

Active vibration control of an axially moving string using space feedforward and feedback controllers is presented. Closed-form results for the transverse response of both the uncontrolled and controlled string are given in the s domain. The space feedforward controller is established by employing the idea of wave cancellation. The proposed control law indicates that vibration in the region downstream of the control force can be cancelled. With the space feedforward control, the mode shapes of the axially moving string are changed such that the free response tends to zero in the downstream region. An interesting physical interpretation is that the control force acts effectively as a holder (active support) which limits the vibration of the string to the upstream region and eliminates any vibration in the downstream region. Simulation results show that the response of the string to both sinusoidal and random excitations is suppressed by applying the space feedforward control. The feedback controller is introduced to attenuate the response of the string due to undesired disturbances in the downstream.

scholarly journals MIMO Active Vibration Control of Magnetically Suspended Flywheels for Satellite IPAC Service

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Junyoung Park ◽  
Alan Palazzolo ◽  
Raymond Beach
Keyword(s):  
Vibration Control ◽  
Attitude Control ◽  
High Frequency ◽  
Active Vibration Control ◽  
Control Algorithms ◽  
Control Law ◽  
Frequency Noise ◽  
Active Vibration ◽  
Simulation Results ◽  
And Control

Theory and simulation results have demonstrated that four, variable speed flywheels could potentially provide the energy storage and attitude control functions of existing batteries and control moment gyros on a satellite. Past modeling and control algorithms were based on the assumption of rigidity in the flywheel’s bearings and the satellite structure. This paper provides simulation results and theory, which eliminates this assumption utilizing control algorithms for active vibration control (AVC), flywheel shaft levitation, and integrated power transfer and attitude control (IPAC), that are effective even with low stiffness active magnetic bearings (AMBs) and flexible satellite appendages. The flywheel AVC and levitation tasks are provided by a multiple input–multiple output control law that enhances stability by reducing the dependence of the forward and backward gyroscopic poles with changes in flywheel speed. The control law is shown to be effective even for (1) large polar to transverse inertia ratios, which increases the stored energy density while causing the poles to become more speed dependent, and for (2) low bandwidth controllers shaped to suppress high frequency noise. Passive vibration dampers are designed to reduce the vibrations of flexible appendages of the satellite. Notch, low-pass, and bandpass filters are implemented in the AMB system to reduce and cancel high frequency, dynamic bearing forces and motor torques due to flywheel mass imbalance. Successful IPAC simulation results are presented with a 12% initial attitude error, large polar to transverse inertia ratio (IP∕IT), structural flexibility, and unbalance mass disturbance.

scholarly journals Thermal Effects on Vibration and Control of Piezocomposite Kirchhoff Plate Modeled by Finite Elements Method

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
M. Sanbi ◽  
R. Saadani ◽  
K. Sbai ◽  
M. Rahmoune
Keyword(s):  
Optimal Control ◽  
Finite Element ◽  
Thermal Effects ◽  
Thermal Gradient ◽  
Active Vibration Control ◽  
Control Procedure ◽  
Finite Element Approximations ◽  
Plate Vibrations ◽  
Active Vibration ◽  
And Control

Theoretical and numerical results of the modeling of a smart plate are presented for optimal active vibration control. The smart plate consists of a rectangular aluminum piezocomposite plate modeled in cantilever configuration with surface bonded thermopiezoelectric patches. The patches are symmetrically bonded on top and bottom surfaces. A generic thermopiezoelastic theory for piezocomposite plate is derived, using linear thermopiezoelastic theory and Kirchhoff assumptions. Finite element equations for the thermopiezoelastic medium are obtained by using the linear constitutive equations in Hamilton’s principle together with the finite element approximations. The structure is modelled analytically and then numerically and the results of simulations are presented in order to visualize the states of their dynamics and the state of control. The optimal control LQG-Kalman filter is applied. By using this model, the study first gives the influences of the actuator/sensor pair placement and size on the response of the smart plate. Second, the effects of thermoelastic and pyroelectric couplings on the dynamics of the structure and on the control procedure are studied and discussed. It is shown that the effectiveness of the control is not affected by the applied thermal gradient and can be applied with or without this gradient at any time of plate vibrations.

Vibration Control of Parallel Identical Flexible Structures Using Interactive Force

2001 ◽  
Author(s):  
Shigeru Kougo ◽  
Hiroshi Fujihara ◽  
Katsuhiko Yoshida ◽  
Hiroyuki Tanaka ◽  
Toru Watanabe ◽  
...  
Keyword(s):  
Vibration Control ◽  
Control Experiment ◽  
Natural Frequencies ◽  
Control Mechanism ◽  
Reaction Force ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Control Performance ◽  
Active Vibration ◽  
And Control

Abstract This paper deals with active vibration control of two identical flexible structures arranged in parallel. One of the authors had presented a vibration control mechanism so that two or more structures are connected via non-contact actuators in which one structure is utilized as a reaction wall for another structure’s control mutually. However, in such a mechanism, the control performance reduces as the natural frequencies of structures become closer. In this report, authors present a modified mechanism in which actuators are connected to the structures with long arms so that the direction of vibration in a mode differs on each structure. In this way, the reaction force from the actuator on structure is introduced to another structure for dissipative force even if the properties of structures are identical. Computer simulation and control experiment are carried out and the effectiveness of presented mechanism is confirmed.

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