Active Control for Whirling Motion of Flexible Rotor

1991 ◽  
Vol 3 (4) ◽  
pp. 360-364 ◽  
Author(s):  
Takakazu Ishimatsu ◽  
◽  
Takashi Shimomachi ◽  
Nobuyoshi Taguchi ◽  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Active Control ◽  
Active Vibration Control ◽  
Digital Controller ◽  
Flexible Rotor ◽  
Whirling Motion ◽  
Active Vibration ◽  
Electromagnetic Damper

In a rotational machine, unbalance on the rotor is formidable since it causes resonance synchronized with the rotation of the rotor. In order to suppress this unfavorable vibration, we built an active vibration control system of flexible rotor using an electromagnetic damper. Our control system is composed of a digital controller to suppress the rotationally synchronized whirling motion and also a conventional analogue controller. Using our control system, whirling motion of the rotor under various rotating speeds was suppressed significantly.

Two-Level Control Structure of Magnetic Bearings

1993 ◽  
Vol 5 (5) ◽  
pp. 438-442 ◽  
Author(s):  
Nobuyoshi Taguchi ◽  
◽  
Takakazu Ishimatsu ◽  
Takashi Shimomachi ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Control Structure ◽  
Active Vibration Control ◽  
Experimental Results ◽  
Magnetic Bearings ◽  
Active Magnetic Bearings ◽  
Level Control ◽  
Whirling Motion ◽  
Active Vibration

Active magnetic bearings have several advantages over conventional mechanical and fluid bearings. However, when the magnetic bearings are used at high rotational speeds, whirling motions and vibrations synchronized with the rotation of the rotor should be considered. In order to suppress these unfavorable vibrations of rotor which is supported by magnetic bearings, we have developed an active vibration control system with a two-level control structure. Experimental results show that our active bearings system effectively suppresses the whirling motion.

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.

Hardware Design for Active Vibration Isolation Controller

2011 ◽  
Vol 211-212 ◽  
pp. 1061-1065
Author(s):  
Qiang Hong Zeng ◽  
Shi Jian Zhu ◽  
Jing Jun Lou ◽  
Shui Qing Xie
Keyword(s):  
Control System ◽  
Vibration Control ◽  
Active Control ◽  
High Speed ◽  
Vibration Isolation ◽  
Active Vibration Control ◽  
Signal Acquisition ◽  
Acceleration Sensor ◽  
Series Acceleration ◽  
Active Vibration

The active vibration control system are described in this paper, and the controller was designed for the active control system, the controller is based on ARM Cortex M3 microcontroller core, ICP series acceleration sensor is use for signal acquisition module, the A / D converter module was designed based on ADS1158 chip, the D/ A converter module was designed based on DAC8564 chip. The controller has the characteristics of high speed and versatility.

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.

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