Active noise control in the presence of uncertain and time-varying disturbances

Overview & Synopsis

The aim of this thesis is the development and application of different control methods for Active Noise Control in the presence of uncertain and time-varying disturbances. A model-based controller design is applied and a full methodology for model identification is introduced. In this context, a reconfigurable test bench based on a noise silencer for ducts has been designed and built. It is fully equipped with sensors and actuators in order to test the developed algorithms in diverse configurations.A feedback scheme is established for the case where narrowband disturbances are present. Based on the Internal Model Principle, fixed linear and robust controllers are designed and compared with the proposed adaptive feedback controller using a Youla-Kučera parametrization. For the case where disturbances have broadband characteristics, a feedforward scheme is proposed. This approach requires the introduction of an additional sensor which creates an internal positive coupling, requiring a specific design in order to avoid possible instabilities. In this framework, Infinite (IIR) and Finite (FIR) Impulse Responses adaptive feedforward compensators, as well as Youla-Kučera parametrized adaptive feedforward compensators are compared.The estimated models' quality for control design as well as the control capabilities themselves are illustrated by the experimental performance of the controllers implemented on the test bench for various tests setup conditions.