Combined feedback and adaptive digital control of cylinder vibrations

A control algorithm using a combined feedback and adaptive control strategy was designed and implemented using digital and analog components. The objective of the controller is to attenuate the vibrations of an open cylinder. The frequency content of the force is broadband noise with a relatively strong harmonic component. Actuation is provided by piezoceramic actuators bonded to the cylinder surface. Both strain and strain rate sensors were developed for this control task. Strain sensing is accomplished by piezoelectric film and piezoelectric ceramic elements bonded to the cylinder. Strain rate sensing is accomplished using distributed piezoelectric film bonded to the cylinder surface together with an interface circuit. Results show that the adaptive controller rejects single frequency vibrations both with and without feedback control. However, by adding an analog feedback control loop, broadband disturbances are attenuated, and the adaptive controller performance is improved