Eventos Anais de eventos
DINAME 2017
XVII International Symposium on Dynamic Problems of Mechanics
Vibration Control of a Journal-Bearing Supported Rotor Using Gain-Scheduled Controller via LMI
Submission Author:
Matheus Freire Wu , SP , Brazil
Co-Authors:
Matheus Freire Wu, Ricardo Ugliara Mendes, Katia Lucchesi Cavalca Dedini
Presenter: Matheus Freire Wu
doi://10.26678/ABCM.DINAME2017.DIN17-0002
Abstract
Rotating machinery concepts are present in several modern industrial applications. Typically, the main obstacles to achieve higher efficiency, speed and reliability are phenomenon that cause vibration. An interesting option for rotor support are hydrodynamic bearings, which offer low friction, high damping, and a fine ratio between load and operational speed. However, there is a downside, the oil-whip excites the system and sets a threshold to rotational speed due to high vibration levels, known as fluid-induced instability. This behavior can be described by a nonlinear variation of the system's model parameters (damping and stiffness) according to the rotational speed. This paper aims to determine an active control law that allows to surpass the instability speed threshold, via a magnetic actuator. For this matter, a two-stage linear matrix inequalities (LMI) approach is used to determine an output gain matrix, dependant on the rotational speed, able to stabilize the oil-whip and reduce the vibration levels at the critical speed. The attained performance is analyzed by means of numerical simulations, and then compared to μ-synthesis and H∞ controllers.
Keywords
rotating machinery, oil-whip, LMI, gain-scheduled control
