Suppression of Persistent Rotor Vibrations Using Adaptive Techniques

Abstract

Recent work in the area of adaptive control has seen the development of techniques for the adaptive rejection of persistent disturbances for structural systems. They have been implemented and tested for large-scale structural systems, with promising results, but have not been widely applied to smallerscale systems and devices. Rotor systems are subject to a variety of persistent disturbances (for example, due to mass imbalance, blade-pass effects) that occur at the rotor running speed or multiples of the running speed. The frequencies of such disturbance forces are generally known, but their magnitudes tend to vary over time. Adaptive techniques to counter the effects of such disturbances would appear to be a promising strategy in this regard. In order to assess the effectiveness of adaptive disturbances rejection for rotor applications and identify issues associated with implementation, and adaptive disturbance rejection control is developed, implemented, and tested for a magnetic-bearing-supported rotor system. Some conclusions and insights concerning the application of this method to rotor system vibration suppression are presented and discussed.

Harmonic disturbance attenuation in a three-pole active magnetic bearing test rig using a modified notch filter

“…Both methods use adaptive techniques to generate a harmonic signal which is injected into the control loop to cancel the harmonic disturbances. In the first approach, a harmonic force is generated by an AMB with magnitude equal to the unbalance force, but phase in the opposite direction (Nonami et al., 1998; Matras et al., 2006; Fan et al., 2008). Despite the effectiveness, this method produces large reaction forces and coil currents which cause vibration and noise in the foundation and power loss in the coils, especially in high rotational speeds.…”

Static mass imbalance identification and vibration control for rotor of magnetically suspended control moment gyro with active-passive magnetic bearings

“…The previous literature about the imbalance vibration control for magnetically suspended rotors mainly investigated mass imbalance identification (Lum et al, 1996;Liu et al, 2008;Jiang et al, 2012), null displacement control (Herzog et al, 1996;Shi et al, 2002;Huang and Lin, 2004;Matras et al, 2006;Grochmal and Lynch, 2007) and null vibration control (Li et al, 2003(Li et al, , 2002Wei and Xiang, 2012;Fang et al, 2013a,b;Xu et al, 2013). Liu et al (2008) regard the static mass imbalance as a displacement disturbance, and a neural network observer is employed to observe the mass imbalance.…”

Parallel Automatic Balance Control Method for the Magnetically Suspended Flywheel

“…The other vibration control method is the automatic balance control, by the method of which the rotor rotates around the approximate inertial axis to minimize synchronous com-pensation force [14][15][16]. Since it is desired to minimize the base vibration from the rotor and avoid the power amplifier saturation caused by the excessive control current, the automatic balance control method is usually adopted.…”