scholarly journals Criterion Functions and Control Characteristics in Active Vibration Control.

1992 ◽  
Vol 58 (552) ◽  
pp. 2373-2380
Author(s):  
Sungkook KANG ◽  
Kazuo YOSHIDA
Author(s):  
Junyoung Park ◽  
Alan Palazzolo ◽  
Raymond Beach

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.


Author(s):  
Shigeru Kougo ◽  
Hiroshi Fujihara ◽  
Katsuhiko Yoshida ◽  
Hiroyuki Tanaka ◽  
Toru Watanabe ◽  
...  

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.


Sensors ◽  
2019 ◽  
Vol 19 (3) ◽  
pp. 540 ◽  
Author(s):  
Asif Khan ◽  
Heung Kim

In this paper, the active vibration control of a piezo-bonded laminated composite is investigated in the presence of sensor partial debonding and structural delamination. Improved layerwise theory, higher-order electric potential field, and the finite-element method were employed to develop an electromechanically coupled model for the two types of damage (i.e., sensor partial debonding and delamination). The developed model was numerically implemented on a single-input-multi-output (SIMO) system to demonstrate the effects of sensor partial debonding and structural delamination on the ability of a constant gain velocity feedback (CGVF) controller to attenuate vibration. The two types of damage were assessed in terms of controlled outputs of the sensors, nodal displacements, and control input signals being applied to the actuator to suppress vibrations. The obtained results showed that the sensor partial debonding and structural delamination have opposite effects on the vibration-attenuation characteristics of the CGVF controller. The presence of partial debonding in the sensor made the controller less able to suppress vibrations because of a spurious sensing signal, whereas structural delamination increased the control authority of the controller because of the loss of structural stiffness that results from structural delamination.


2019 ◽  
Vol 25 (19-20) ◽  
pp. 2611-2626 ◽  
Author(s):  
Yifan Lu ◽  
Marco Amabili ◽  
Jian Wang ◽  
Fei Yang ◽  
Honghao Yue ◽  
...  

Lightweight optical mirrors usually play key roles in aerospace and optical structural systems applied to space telescopes, radars, solar collectors, communication antennas, etc. Due to their high flexibility and low damping properties, external excitations such as orbital maneuver may induce unexpected oscillations and thus reduce their working performance. Active vibration control is therefore essential for the lightweight optical mirror systems. In this spirit, a lightweight mirror structronic system with a linear quadratic optimal controller is presented. The mirror is modeled as a membrane plate with pretension and distributed polyvinylidene fluoride sensors and actuators. The sensing sensitivity of the piezoelectric (PVDF) sensors and the modal actuation factor of the PVDF actuators are derived. The state-space equations are established and the feedback control gains between sensing and control signals are obtained. Sensor and actuator of different shape, size, and position are employed to actively control the first four natural modes of the mirror. The influences of mode order, pretension, and the two weighting factors Q and R on the control performance are also investigated. Analytical results in this paper could guide the design and layout of the PZT sensor and actuator on lightweight membrane plate mirrors.


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