Controllers for Attenuation of Lateral Rotor Vibration Part I: Controller Design

Controller designs for the attenuation of rotor vibration are investigated. Disturbance inputs leading to vibration are classified and related to control forces and defined control states. Optimization based on the H∞ norm is then used to minimize the influence of forcing disturbances, modelling error and measurement error. The practicalities of applying the method to an experimental rotor-bearing system, with hardware constraints on controller order, are stated. The controller was implemented experimentally to conduct steady state and mass loss tests. Steady synchronous, non-synchronous and transient vibration attenuation was demonstrated. It was also shown that measurement error, caused by shaft surface roughness, can be incorporated into the controller design without the need to remove the roughness component from the measured displacement signals. If the roughness influence is not included in the design and the uncontrolled vibration is small, unnecessary control forces may result, causing an increase in vibration.

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On the Control of Synchronous Vibration in Rotor/Magnetic Bearing Systems Involving Auxiliary Bearing Contact

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1689362 ◽

2004 ◽

Vol 126 (2) ◽

pp. 366-372 ◽

Cited By ~ 8

Author(s):

P. S. Keogh ◽

M. O. T. Cole ◽

M. N. Sahinkaya ◽

C. R. Burrows

Keyword(s):

Controller Design ◽

Magnetic Bearing ◽

Contact Forces ◽

Normal Operation ◽

Design Parameters ◽

Rotor Vibration ◽

Full Control ◽

Bearing Contact ◽

Vibratory Motion ◽

Auxiliary Bearing

During the normal operation of rotor/magnetic bearing systems, contacts with auxiliary bearings or bushes are avoided. However, auxiliary bearings are required under abnormal conditions and in malfunction situations to prevent contact between the rotor and stator laminations. Studies in the open literature deal largely with rotor drop and the requirements of auxiliary bearings design parameters for safe rundown. Rotor drop occurs when the rotor is delevitated and no further means of magnetic bearing control is available. This paper considers the case when full control is still available and rotor/auxiliary bearing contact has been induced by an abnormal operating condition or a temporary fault. It is demonstrated that events leading to contact from a linearly stable rotor orbit can drive the rotor into a nonlinear vibratory motion involving persistent contacts. Furthermore, the phase of the measured vibration response may be changed to such an extent that synchronous controllers designed to minimize rotor vibration amplitudes will worsen the rotor response, resulting in higher contact forces. A modified controller design is proposed and demonstrated to be capable of returning a rotor from a contacting to a noncontacting state.

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Continuous Time Controller Design

IEE Review ◽

10.1049/ir:19910107 ◽

1991 ◽

Vol 37 (6) ◽

pp. 228

Author(s):

Stephen Barnett

Keyword(s):

Continuous Time ◽

Controller Design

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Path Tracking Controller Design of Automatic Guided Vehicle Based on Four-Wheeled Omnidirectional Motion Model

International Journal of Automotive and Mechanical Engineering ◽

10.15282/ijame.17.2.2020.18.0599 ◽

2020 ◽

Vol 17 (2) ◽

pp. 7996-8010

Author(s):

X. Wu ◽

Y. Yang

Keyword(s):

Control System ◽

Fuzzy Controller ◽

Controller Design ◽

Threshold Value ◽

Position Angle ◽

Path Tracking ◽

Global Coordinate System ◽

Automatic Guided Vehicle ◽

Input Variables ◽

Industrial Pc

This paper presents a new design of omnidirectional automatic guided vehicle based on a hub motor, and proposes a joint controller for path tracking. The proposed controller includes two parts: a fuzzy controller and a multi-step predictive optimal controller. Firstly, based on various steering conditions, the kinematics model of the whole vehicle and the pose (position, angle) model in the global coordinate system are introduced. Secondly, based on the modeling, the joint controller is designed. Lateral deviation and course deviation are used as the input variables of the control system, and the threshold value is switched according to the value of the input variable to realise the correction of the large range of posture deviation. Finally, the joint controller is implemented by using the industrial PC and the self-developed control system based on the Freescale minimum system. Path tracking experiments were made under the straight and circular paths to test the ability of the joint controller for reducing the pose deviation. The experimental results show that the designed guided vehicle has excellent ability to path tracking, which meets the design goals.

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