Modified Bang-Bang Control for Vibratioas of Active Magnetic Bearing Equipped Rotor

Abstract

Recently, rotating machinery requires not only reduction in size, weight and power but high speed and precision. Active Magnetic Bearing (AMB) can fullfill these requirements. AMB supports an axis in noncontact, so it doesn't wear out and is able to have high rotational speed. To compensate the lack of mechanical contact damping, however, feedback control causes a problem in that the rotor easily vibrates at its natural frequency. In this study, the main object is stabilization control for spillover and disturbance. The PID controller used commonly for AMB rotor system adds Bang Bang control such as producing friction damping. The gain of Bang Bang control is modified by a function of displacement instead of velocity, for reasons of efficiency of control energy and influence to the stability of high frequency vibrations. The effectiveness of this controller is proven by numerical simulations and experiments.