Active noise control of an acoustic duct using feedback control

Forced air cooling systems, such as an airconditioning system produce noise. For a pleasant living environment, this noise is undesirable. A way to suppress produced noise is reducing the sound in the duct where the air flows through afterwards. a his report handles the noise reduction in an active duct silencer by the use of a discrete feedback controller. Models of the involved processes are made. With these models and suitable choices of weighting functions, an H2 optimal controller is calculated. The controller is reduced taking into account the sensitivity of the closed loop process. Stability and performance are maintained in this way. Finally the controller is implemented on the system and a validation has been made to indicate the active noise cancellation that could be obtained with feedback control.