A microprocessor-based position control system for a telescope secondary mirrorThe pointing requirements for the Shuttle IR Telescope Facility (SIRTF), which consists of an 0.85-m cryogenically cooled IR telescope, call for an image stability of 0.25 arcsec. Attention is presently given to a microprocessor-based position control system developed for the control of the SIRTF secondary mirror, employing a special control law (to minimize energy dissipation), a precision capacitive position sensor, and a specially designed power amplifier/actuator combination. The microprocessor generates the command angular position and rate waveforms in order to maintain a 90 percent dwell time/10 percent transition time ratio independently of chop frequency or amplitude. Performance and test results of a prototype system designed for use with a demonstration model of the SIRTF focal plane fine guidance sensor are presented.
Document ID
19830056215
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Lorell, K. R. (NASA Ames Research Center Moffett Field, CA, United States)
Barrows, W. F. (NASA Ames Research Center Moffett Field, CA, United States)
Clappier, R. R. (Penelco Corp. Los Altos, CA, United States)
Lee, G. K. (Recom Software, Inc. Cupertino, CA, United States)