Constrained Quadratic Programming, Active Control of Rotating Mass Imbalance

Manchala, Daniel; Palazzolo, Alan; Kascak, Albert F.; Montague, Gerald T.; Brown, Gerald V.

doi:10.1006/jsvi.1996.1030

Cited by 14 publications

(10 citation statements)

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“…Previously, a number of unbalance control schemes have been proposed for magnetic bearings in which the controller acts on measurements of rotor displacements and produces synchronous control forces at the bearings, updated in an iterative manner to cancel the effects of unbalance forces e.g. [9][10][11][12][13]. Although situations involving rotor-stator contact are not considered in these studies, a similar control approach will be used here.…”

Section: Control Implicationsmentioning

confidence: 99%

Model-Free Control of Touchdowns Involving Circular Whirl in Rotor-Magnetic Bearing Systems

Cole

2009

JSDD

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In this paper, the dynamics associated with rotor-stator touchdowns involving full circular rub are considered. The expected range of phase shifts occurring in various measurable signals are examined from a theoretical standpoint, with the aim of developing model-free control algorithms that can limit contact force magnitudes during touchdown with auxiliary bearings and ensure contact-free rotor levitation can be restored following persistent contact. Two different strategies are proposed according to whether touchdown planes can be considered collocated with the magnetic bearings or not. Requirements for successful operation, in terms of available sub-models and measurement information are explained and verified through experimental tests on a multi-mode flexible rotor test rig.

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Section: Control Implicationsmentioning

confidence: 99%

Model-Free Control of Touchdowns Involving Circular Whirl in Rotor-Magnetic Bearing Systems

Cole

2009

JSDD

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“…The H -in nity design (6) overcomes this problem, but at the expense of steady state performance. Again, the steady state norm-bound controller design (7) achieves the best combination of robust stability and performance.…”

Section: Predicted Controller Performancementioning

confidence: 99%

“…Such methods have been enhanced with improved robustness features and techniques to address speed dependence or control multiple disturbance frequencies [4,5]. F urther studies have considered controller designs for optimized transient vibration control [6][7][8], e.g. during rotor mass losstype events.…”

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confidence: 99%

Rotor vibration with auxiliary bearing contact in magnetic bearing systems Part 2: Robust synchronous control for rotor position recovery

Cole

Keogh

2003

Proceedings of the Institution of Mechanical Engineers, Part C:

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A number of conditions or events may produce rotor motion that involves contact with auxiliary bearings. Standard adaptive and closed-loop control strategies based on linear dynamics can cause instability when contact occurs, resulting in increased contact forces and vibration compared with the uncontrolled case. This paper introduces a method for robust control of synchronous vibration components that can maintain dynamic stability during interaction between the rotor and auxiliary bearings. The controllers are designed to minimize the severity and duration of contact and ensure that the rotor vibration returns to optimal levels, provided that sufficient control force capacity is available. Synthesis of controller gain matrices is based on a linear time-varying system model, which can be derived from either on-line identification routines or theoretical modelling and simulation. The controllers are tested experimentally on a flexible rotor system with magnetic bearings and are shown to restore rotor position control to optimal levels without further contact.

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“…The ideal control system design assumes that any magnitude of control is feasible. Within all systems, however, a limit must exist on the available control energy [7]. Saturation causes there to be a difference between the expected and actual control signals which leads to a resulting difference between the expected and actual system outputs.…”

Section: Introductionmentioning

confidence: 96%

Using a pole-placement switching technique to avoid resonance in systems forced by a swept sinewave disturbance

Scott

Weightman

Levesley

2004

Smart Structures and Materials 2004: Smart Structures and Integrated Systems

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Many forced systems are prone to undesirable levels of oscillation if lightly damped modes are present with their frequency range of operation. Rotary systems, for example, can experience these problems during the speed up or speed down stage of operation. Resonant motion can damage or effect the accuracy of operation of such systems and is, therefore, highly undesirable. Many closed-loop controllers avoid this by suppressing the mode itself such that at resonance the modal vibration amplitude is small (i.e. highly damped). The current work presents an alternative novel switching controller, which suppresses the system not by applying a high amount of damping but rather by moving the resonant mode such that it is never excited. From the basis of an accurate plant model, two pole-placement controllers are designed and implemented both in simulation and experiment on a cantilever smart structure. These controllers are shown to successfully change the natural frequency value, while retaining the same damping ratio value. A novel switching system is employed that calculates the optimal switching position by running a simulation of the desired systems in parallel to the controlled open-loop system. Moreover, the system minimises transients occurred by switching back and forth between controllers, thus increasing the efficiency of the system. By comparing the experimental results to a conventional high damping pole-placement controller that applies a similar amount of control effort, a lower overall level of amplitude suppression can be seen.

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Constrained Quadratic Programming, Active Control of Rotating Mass Imbalance

Cited by 14 publications

References 0 publications

Model-Free Control of Touchdowns Involving Circular Whirl in Rotor-Magnetic Bearing Systems

Model-Free Control of Touchdowns Involving Circular Whirl in Rotor-Magnetic Bearing Systems

Rotor vibration with auxiliary bearing contact in magnetic bearing systems Part 2: Robust synchronous control for rotor position recovery

Using a pole-placement switching technique to avoid resonance in systems forced by a swept sinewave disturbance

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