Beam Train Flexible Structure Control for Airborne/Space-Based Systems

The increasing demands for higher performance optical acquisition, tracking, and pointing (ATP) systems, combined with cost pressures requiring lighter payloads, indicates a need for a new approach to slewing and structural control. The use of lighterweight structures exacerbates the interaction of slew maneuvers and acoustic disturbances with the system's flexible modes, causing errors in the alignment and shape of the optical components that result in degraded optical performance. Such gimbaledsystems will require control systems that can accommodate the time-varying disturbances, rigid-body, and flexible dynamics resulting from the changing geometry as the payload is slewed.To address these issues, we showed the feasibility of (Phase I) and propose to demonstrate (Phase II) an adaptive control design approach that works during operation to autonomously identify the time-varying gimbaled optical system dynamics affecting theslewing bandwidth, then design feedback and feedforward control laws to achieve predefined performance and stability criteria. Our technical approach is based on our Frequency Domain Expert (FDE) control algorithm, which has been demonstrated on theInternational Space Station (ISS) as part of the Middeck Active Control Experiment (MACE-II) and is currently being applied to the PowerSail program.