Active Vibration Control of Rotating Machinery With a Hybrid Piezohydraulic Actuator System

1995 ◽  
Vol 117 (4) ◽  
pp. 767-776 ◽  
Author(s):  
P. Tang ◽  
A. B. Palazzolo ◽  
A. F. Kascak ◽  
G. T. Montague

An integrated, compact piezohydraulic actuator system for active vibration control was designed and developed with a primary application for gas turbine aircraft engines. Copper tube was chosen as the transmission line material for ease of assembly. Liquid plastic, which meets incompressibility and low-viscosity requirements, was adjusted to provide optimal actuator performance. Variants of the liquid plastic have been prepared with desired properties between −40°F and 400°F. The effectiveness of this hybrid actuator for active vibration control (AVC) was demonstrated for suppressing critical speed vibration through two critical speeds for various levels of intentionally placed imbalance. A high-accuracy closed-loop simulation, which combines both finite element and state space methods, was applied for the closed-loop unbalance response simulation with/without AVC. Good correlation between the simulation and test results was achieved.

Author(s):  
Punan Tang ◽  
Alan B. Palazzolo ◽  
Albert F. Kascak ◽  
Gerald T. Montague

An integrated, compact piezo-hydraulic actuator system for active vibration was designed and developed with a primary application for gas turbine aircraft engines. Copper tube was chosen as the transmission line material for ease of assembly. Liquid plastic which meets incompressibility and low viscosity requirements was adjusted to provide optimal actuator performance. Variants of the liquid plastic have been prepared with desired properties between −40°F and 400° F. The effectiveness of this hybrid actuator for active vibration control (AVC) was demonstrated for suppressing critical speed vibration through two critical speeds for various levels of intentionally placed imbalance. A high accuracy closed loop simulation which combines both finite element and state space methods was applied for the closed loop unbalance response simulation with/without AVC. Good correlation between the simulation and test results was achieved.


1997 ◽  
Vol 119 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Punan Tang ◽  
Alan B. Palazzolo ◽  
Albert F. Kascak ◽  
Gerald T. Montague

Electromechanical modeling of a hybrid piezohydraulic actuator system for active vibration control was developed. The transfer function of piezoelectric actuator was derived from the electromechanical potential energy law. This transfer function represents the dynamic relationship between input electric voltage and piezoelectric actuator displacement. The hydraulic actuator was characterized by impedance matching in which its transfer functions were experimentally determined. The transfer functions were transformed into a state-space representation, which is easily assembled into an active vibration control (AVC) closed-loop simulation. Good correlation of simulation and test was achieved for the hybrid system. A closed-loop dynamic simulation for imbalance response with/without AVC of a spinning rotor test rig at NASA Lewis was performed and showed excellent agreement with test results. The simulation couples the piezoelectric, hydraulic, and structural (rotor) components.


2020 ◽  
Vol 53 (3-4) ◽  
pp. 531-540
Author(s):  
Tao Lai ◽  
Junfeng Liu

In order to improve the vibration responses of rotor system, this paper presents an active vibration control technique for a rotor-bearing-actuator system with the use of robust eigenvalue placement method. By analyzing the characteristics of the piezoelectric stack actuator, bearing and rotor, a rotor-bearing-actuator system is modeled. Based on this dynamical model, a reduced-order technique is used to establish the state equation in the modal space. A robust eigenvalue placement method, which can enhance the robustness of system to model error and uncertain factors by optimizing the close-loop eigenmatrix with a small condition number, is proposed to carry out the active vibration control for system. The good results indicate that the eigenvalue can be placed to precise position, and the displacement responses get effectively suppressed with the proposed method. Meanwhile, the optimized close-loop eigenmatrix can possess a small condition number, which means the system has achieved excellent robustness.


Author(s):  
Yusuke Sato ◽  
Hiroshi Sodeyama ◽  
Makoto Hayama ◽  
Shin Morishita

As one of the semi-active vibration control devices for mechanical or civil structures, magneto-rheological fluid dampers have been enthusiastically studied and developed since the 1990s. A new magneto-rheological material for such dampers has been developed to provide a practical solution to the significant common drawback of sedimentation of ferromagnetic fine particles in the fluid. Industrial grease is used as the dispersion medium in this material. The thickener to be added in the grease to control the rheological properties seems to prevent separation of the particles from the dispersion medium. Several performance tests were carried out with a proto-type of the damper with the newly developed magneto-rheological grease, namely, the magneto-rheological grease damper. Based on the test results, the energy dissipation capabilities of the damper and the basic characteristics of the magneto-rheological grease were verified to provide semi-active vibration control. Moreover, the analytically-derived design formulae for the damper were improved on the basis of the test results.


2000 ◽  
Author(s):  
Sathya V. Hanagud ◽  
Patrick J. Roberts

Abstract In most structures, fatigue critical areas are associated with regions of high stresses. Sometimes, passive stiffening of structures can displace these high stress regions. Thus, for most applications, active vibration control is preferred. However, the question of whether an active vibration control scheme involving a set of actuators will reduce stresses in the whole structure or create high stress areas in the vicinity of the actuators arises. In previous works, this question has been addressed for cantilever beams which showed that the stresses are reduced by approximately the same order of magnitude as the reduction in vibrations. However, many aerospace structures are constructed of thin walled components whose response to vibration reduction can be very different than that of beams. In this paper, the stresses induced by an active vibration control system, based on the use of an offset piezoceramic stack actuator with acceleration feedback control, are investigated in a plate structure. A 3-D finite element simulation of the closed loop active vibration control system is developed and both the closed loop stresses and vibration amplitude reductions are studied.


Author(s):  
Rajiv Kumar

For active vibration control applications, positive position feedback (PPF) type controller is quite suitable. These controllers are of low order so are easy to implement in practice. These controllers avoid the problem of control spillover also. However, a systematic design methodology is not available for the design of these controllers. For multimode vibration control applications, in the presence of instrumentation, controller design becomes even more difficult. In the present paper, a systematic design procedure has been suggested to design the PPF controller. The proposed controller is designed by minimizing the H2 or H∞ norm of the closed loop (CL) system. The direct search methods based on pattern search technique has been used. The controller designed in this way can provide uniform damping to all the modes. The problems caused by the instrumentation (i.e., phase lead and lag) and time delay actually present in the control loop can be completely eliminated. Since, the controller is designed by minimizing the H∞ norm of the closed loop system, it is robust in nature. With the proposed methodology, the use of other complicated frequency domain techniques to design the controller can be avoided.


1999 ◽  
Author(s):  
Maxime P. Bayon de Noyer ◽  
Patrick J. Roberts ◽  
Sathya V. Hanagud

Abstract In most structures, fatigue critical areas are associated with regions of high stresses. Passive stiffening of structures usually displaces these high stress regions. Thus, for most applications, active vibration control is preferred. However, the question of whether an active vibration control scheme involving a set of actuators will reduce stresses in the whole structure or create high stress areas in the vicinity of the actuators arises. In this paper, the stresses induced by an active vibration control system based on the use of an offset piezoceramic stack actuator with acceleration feedback control are investigated. Using a modal analysis of the actuator acting on a cantilever beam, a low frequency approximation of the actuator is developed in the form of a spring and two driving forces. Based on this approximation, a 3-D finite element simulation of the closed loop active vibration control system is developed and the closed loop stresses are studied.


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