Adaptive real-time control for three-dimensional active attenuation of sound

Three objectives were addressed: to investigate the performance of active noise control systems and develop models of acoustic plants which could be used to design and implement active controllers for 3-D acoustic systems; to integrate these models into modern control formulations for active noise control applications; and to implement active noise control and investigate feasibility of using real-time adaptive control algorithms in several realistic three-dimensional applications. Conventional boundary element acoustical prediction schemes were used to develop a generalized prediction method to evaluate the performance of active noise control configurations for conditions where the acoustic environment could be specified. Models were developed which could be integrated into modern control formulations for analysis of stability, observability, and controllability of closed loop systems.