Controller Design for a Laser Steering Mirror on a Flexible Structure
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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An experimental setup for disturbance rejection and pointing for a structurally borne laser beam path is explored. Motivation for the experiment is the expanding demand for structurally mounted pointing systems in space applications. The design and implementation of a disturbance rejection system is manifested in the form of a proportional-integral and feedforward controlled piezo actuated mirror. Good line-of-sight structural disturbance rejection is demonstrated for the primary transverse flexible modes of a 20 bay, 7.07 meter long, planar truss structure. A bandwidth of 60 Hz is achieved for the closed loop mirror-piezo plant. Two beam pointing systems are explored using a DC motor driven turntable to provide large scale angular movement. The actuation methods are coupled, using the turntable as a single axis gimbal for slow pointing, and the piezo-mirror in a fast disturbance rejection, fine pointing loop. Theoretical design and practical hardware considerations are explored and future research possibilities examined.
- Unmanned Spacecraft