Dynamics and control simulation of the Spacelab Experiment Pointing MountComputer simulations were developed to evaluate the performance of four Experiment Pointing Mounts (EPM) being considered for Spacelab experiments in the 1980-1990 time frame. The system modeled compromises a multibody system consisting of the shuttle, a mechanical isolation device, the EPM, celestial and inertial sensors, bearings, gimbal torque motors and associated nonlinearities, the experiment payload, and control and estimator algorithms. Each mount was subjected to a common disturbance (shuttle vernier thruster firing and man push off) and command (stellar pointing or solar raster scan) input. The fundamental limitation common to all mounts was found to be sensor noise. System dynamics and hardware nonlinearities have secondary effects on pointing performance for sufficiently high bandwidth.
Document ID
19770059943
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Marsh, E. L. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Ward, R. S. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena Calif., United States)