Adaptive Filtering Disturbance Feedforward Approach for Flexible Beam Train Control

In this effort, a novel Adaptive Filtering and Disturbance Feedforward (AFDF) technique is investigated in the context of direct application to the ABL beam control system to mitigate jitter arising from disturbances in or to the High Energy Laser (HEL)Subsystem. Both the HEL and the Mid Optics Bench (MOB) operate in intense aero-acoustic and structural borne vibration environments. The resulting jitter and beam walk results in a risk of significant performance degradation for the Acquisition,Tracking and Pointing, ATP beam train system. As shown in Phase I of this effort, AFDF offers significant improvement in the jitter and beam walk performance of the ATP system. The Spatially Distributed Sensing (SDS) techniques also developed in Phase Ioffer an additional performance enhancement to be investigated in Phase II. A blending of SDS with AFDF techniques showed promise in Phase I for further improving ATP performance. SDS derived signals are coherent with the beam control jitter induced bythe respective modes and represent the dominate contributions of these modes. Thus they are ideal for use with AFDF to simultaneously control and mitigate vibration/acoustic induced effects on the coupled aircraft-HEL system.