| Vibration and noise reduce the perceived quality, productivity, and efficiency of many electromechanical systems. Vibration can cause defects and limit production speeds during manufacturing and produce premature failure of the finished product due to fatigue. Potential contact with a vibrating system or hearing damage from a noisy machine can produce a dangerous, unhealthy, and uncomfortable operating environment. It is often desirable to confine noise and vibration disturbances near their sources and isolate the rest of system from the disturbances. This dissertation focuses on the theoretical study and experimental verification of the adaptive isolation of vibration and noise in discrete and distributed systems.; Controllers are developed for discrete flexible systems, axially moving strings, axially moving beams, and acoustic ducts. For discrete flexible systems, adaptive feedback isolation controllers, based on Lyapunov theory, regulate and allow tracking of the undisturbed (controlled) coordinates in a lumped spring-mass flexible structure. The axially moving string and beam systems consist of a controlled span coupled to a disturbed span via an actuator. Exact model knowledge and adaptive isolation controllers, based on Lyapunov theory, regulate the controlled span from bounded disturbances in the adjacent, uncontrolled span. For noise isolation in acoustic ducts, controllers that use a loudspeaker actuator and two microphone pressure sensors are developed to adaptively decouple adjacent ducts, thereby isolating a controlled or quiet duct from bounded disturbances in an adjacent uncontrolled or noisy duct.; For all of the controllers designed, experiments are implemented to demonstrate the effectiveness of the proposed control algorithms. |
