An approach for achieving a several order of magnitude reduction of vibration in space telescopes is described. The building blocks encompass: active damping in the payload, passive and active vibration isolation in the payload mount, and active steering of the entire payload using feedback from optical sensors to the actuators in the isolator. The layers of control sequentially mitigate vibrations emanating from the disturbance source. This strategy is especially applicable to large space-based optical systems, such as deployable telescopes. A dynamically scaled test bed has been developed to demonstrate this. The test bed incorporates a full-telescope isolator based on passive isolation technology demonstrated on the Chandra X-ray Observatory. A PZT force sensor and a voice coil actuator have been incorporated to provide additional active isolation at low to mid frequencies. The active isolation is implemented in a stable manner using independent modal space control (IMSC). Residual vibrations in the telescope secondary mirror supports are damped using PZT actuator/sensor patches and local analog feedback. Finally, signals from line-of-sight sensors in the two tilt directions are fed to the tilt states in the IMSC controller to effect payload pointing control.

Date Published: 5 August 2003
PDF: 10 pages
Proc. SPIE 5056, Smart Structures and Materials 2003: Smart Structures and Integrated Systems, (5 August 2003); doi: 10.1117/12.483440

Published in SPIE Proceedings Vol. 5056:
Smart Structures and Materials 2003: Smart Structures and Integrated Systems
Amr M. Baz, Editor(s)