Damage identification via asymmetric active magnetic bearing acceleration feedback control

2015 ◽  
Author(s):  
Jie Zhao ◽  
Hans DeSmidt ◽  
Wei Yao
Keyword(s):  
Feedback Control ◽  
Damage Identification ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Acceleration Feedback

Truncated Predictor Feedback Control for Active Magnetic Bearing Systems With Input Delay

2016 ◽  
Vol 24 (6) ◽  
pp. 2182-2189 ◽  
Author(s):  
Se Young Yoon ◽  
Long Di ◽  
Parinya Anantachaisilp ◽  
Zongli Lin
Keyword(s):  
Feedback Control ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Input Delay

Adaptive Forced Balancing for Multivariable Systems

1995 ◽  
Vol 117 (4) ◽  
pp. 496-502 ◽  
Author(s):  
S. Beale ◽  
B. Shafai ◽  
P. LaRocca ◽  
E. Cusson
Keyword(s):  
Feedback Control ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
New Method ◽  
Multivariable Systems ◽  
Force Transmission ◽  
Frequency Tracking ◽  
Mass Unbalance ◽  
And Performance ◽  
Siso Systems

Active magnetic bearing (AMB) actuators support rotors without friction but require feedback control for stabilization and performance. Autobalancing compensation causes AMBs to spin a rotor about its inertial axis to eliminate synchronous force transmission from mass unbalance. Because mass unbalance constitutes a sinusoidal sensor disturbance within the bandwidth, conventional methods can either cause instability or fail to preserve desired bandwidth. We introduce a new method called adaptive forced balancing (AFB) which overcomes these problems. We consider AFB with a frequency tracking capability for SISO systems (i.e., single-end AMB suspensions) and show how to extend it for the MIMO case as applied to a double-end AMB suspension.

scholarly journals Coupling Analysis and Cross-Feedback Control of Three-Axis Inertially Stabilized Platform with an Active Magnetic Bearing System

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Tong Wen ◽  
Biao Xiang ◽  
Waion Wong
Keyword(s):  
Feedback Control ◽  
Vibration Isolation ◽  
Base Plate ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Single Input Single Output ◽  
Control Scheme ◽  
Amb System ◽  
Stabilized Platform ◽  
Inertially Stabilized Platform

An active magnetic bearing (AMB) system is used to suspend the yaw gimbal of three-axis inertially stabilized platform (ISP) to minimize the friction. The dynamic functions of three gimbals in ISP are developed. The base coupling at dynamic base plate is stronger than that at static base plate, and the gimbal coupling among three gimbals increases with the number of unlocked gimbals. Therefore, a cross-feedback control scheme is designed to minimize the base coupling and the gimbal coupling, and then the multi-input multioutput system of three-axis ISP with coupling terms is simplified into three decoupled single-input single-output systems. Experimental results verify that the yaw gimbal suspended by AMB system has better vibration isolation ability than the roll gimbal supported by mechanical bearing, and the gimbal coupling and the base coupling are effectively suppressed by the cross-feedback control scheme.

Cancelling Gyroscopic Effects in AMB Systems With Flexible Rotors via Modal Feedback

2019 ◽  
Author(s):  
Alican Sahinkaya ◽  
Jerzy T. Sawicki
Keyword(s):  
Feedback Control ◽  
Controller Design ◽  
Sensory Information ◽  
Magnetic Bearing ◽  
Open Loop ◽  
State Feedback Control ◽  
Active Magnetic Bearing ◽  
Flexible Rotors ◽  
Amb System ◽  
Gyroscopic Effects

Abstract For active magnetic bearing (AMB) systems with rotors having significant polar to transverse moments of inertia ratio, the influence of gyroscopic effects needs to be considered in controller design procedures to prevent excessive vibrations and potential instability during operation. This consideration leads to conservative controllers due to large uncertainties caused by the rotational speed range of the rotor, or gain-scheduled controllers that require larger computational power, both of which are not desirable. A cross-feedback control has been applied in the literature to compensate for the gyroscopic effects of AMB systems with rigid rotors. However, the method is not applicable to AMB systems with flexible rotors due to lack of full-state sensory information and under actuation. This paper proposes a novel modal state feedback control as an addon controller for AMB systems with flexible rotors to compensate for the gyroscopic effects of selected modes. The aim of the add-on controller is to alter the open loop AMB system such that the open loop dynamics presents reduced gyroscopic effects of the selected modes from a controller point of view, reducing the uncertainties in the model for robust controller design. The proposed approach is demonstrated on an AMB rotor test rig with a rotor configuration featuring noticeable gyroscopic effects. The comparison of the frequency response data of the open loop AMB system with and without the proposed add-on controller shows the feasibility of the approach.

Cracked Shaft Damage Identification via Symmetry Breaking Active Magnetic Bearing Control and Interrogation

2011 ◽  
Author(s):  
J. Zhao ◽  
H. A. DeSmidt
Keyword(s):  
Symmetry Breaking ◽  
Structural Damage ◽  
Damage Identification ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Crack Model ◽  
Lagrange Principle ◽  
Disk System ◽  
Data Set ◽  
Loop Control

A new vibration-based damage identification methodology for cracked rotor systems with periodically time-varying dynamics is developed and demonstrated on a shaft-disk system. This approach is based Floquet theory and utilizes measured changes in the system natural frequencies to estimate the severity and location of shaft structural cracks during operation. The damage identification is enhanced through the use of an Active Magnetic Bearing with adjustable support stiffness and acceleration feedback. Here, a novel symmetry-breaking closed-loop control is employed during the iterative damage identification process to enrich the data set by removing the Eigen degeneracy of the symmetric shaft structure. This approach enables full damage identification from a single sensor and hence without requiring measured modeshape information. The dynamical model of system is built based on the Lagrange principle and the assumed mode method while the crack model is based on fracture mechanics. The method is synthesized via harmonic balance and numerical examples for a shaft/disk system demonstrate the effectiveness in detecting both location and severity of the structural damage.

Magnetic Bearing With Rotating Force Control

1988 ◽  
Vol 110 (1) ◽  
pp. 100-105 ◽  
Author(s):  
H. M. Chen ◽  
M. S. Darlow
Keyword(s):  
Feedback Control ◽  
Force Control ◽  
Vibration Suppression ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
External Disturbances ◽  
Control Loops ◽  
Bearing Stiffness ◽  
Suppression Mechanism ◽  
Measured Displacement

A common attractive type active Magnetic Bearing (AMB) was designed and tested with three parallel feedback control loops. The feedback of the measured AMB journal displacement provides the bearing stiffness. Two special circuits, called Velocity Observer and Acceleration Observer, are formulated for estimating the AMB journal velocity and acceleration based on the same measured displacement without performing differentiation. The feedback control using the estimated velocity provides the AMB damping. The feedback control using the estimated acceleration creates a rotating force which cancels the imbalance force and other external disturbances. The rotating force control can be switched on or off in the designed speed range without causing rotor instability. This additional vibration suppression mechanism greatly enchances the versatility of AMB.

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