Active control of noise and vibration for time-varying transfer paths

Active noise and vibration control has been successful in a limited number of applications. Successful applications often rely on stationary or periodic signals, stationary geometry or small regions of silence. In many potential applications, the signals and or the geometry are to be considered non-stationary. Following a brief review, this paper describes a technique that could be useful in systems for active noise and vibration control to track changes of the primary signal path from noise source to reference sensor, and to track the secondary path from control source to the error sensor.