VIBRATION CONTROL OF A ROTATING DISK

The transverse vibration of a rotating disk has been receiving increasing attention because of its prevailing role as a basic element in rotating machinery applications. To suppress the vibration without suffering from spillover, a feedback controller which can eliminate an infinite number of vibration modes is absolutely needed. The control approach is developed based on the root locus of an infinite number of poles and zeros using one set of discrete sensor and actuator. The root-locus approach can yield the controller of simple scheme. For the colocated sensor and actuator, a feedback controller which contributes the phase angle between 0 and 180° can stabilise all vibration modes. By properly positioning the non-colocated sensor and actuator, a feedback controller that possesses the phase angle between 0 and 180° and a satisfactory amplitude attenuation can lead to the elimination of all the vibration modes except the much higher frequency modes. The sustained oscillation of the much higher frequency modes are usually insignificant, and will eventually die out due to internal structural damping. The proposed controllers have been successfully implemented for simulation.