Accession Number : ADA297860

Title :   Dynamics, Control and Maneuvering of Large Flexible Space Tethered Reflectors, Tele-Robots and Experimental Models. Part 2.

Descriptive Note : Final rept. 1 Feb 94-31 May 95,

Corporate Author : HOWARD UNIV WASHINGTON DC DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Bainum, Peter M. ; Feiyue, Li ; Jianke, Xu ; Zhi, Tan Z. ; Xing, Guang-Qian

PDF Url : ADA297860

Report Date : 31 MAY 1995

Pagination or Media Count : 60

Abstract : The effects of solar radiation heating on a large, thin, shallow spherical orbiting shell system are studied. The shell is representative of a large antenna reflector system which could also be gravitationally stabilized by connecting a sub-satellite to a long tether. After determining the steady state temperature distribution across the thickness of the shell, the corresponding thermal deformation is estimated as a function of the solar incidence angle and material properties. The closed-loop dynamic response of the shell is simulated by using LQR control design synthesis and assuming that 12 point actuators are placed on the outer surface and edge of the shell. Calculations also indicate that the shell's transverse elastic vibrational frequencies may differ significantly from their nominal values due to the solar-thermal influence. A practical control strategy for the minimum-time maneuver problem has been developed and successfully applied to the Naval Research Laboratory's Reconfigurable Spacecraft Host for Attitude and Pointing Experiments (RESHAPE) hardware test facility. This is the first time that the bang-bang type and feedback control strategy has been applied to the RESHAPE facility by including a flexible appendage which is represented with the attachment of a spherical pendulum device to the edge of the RESHAPE platform. (MM)

Descriptors :   *ATTITUDE CONTROL SYSTEMS, *SOLAR RADIATION, *SPACECRAFT TRAJECTORIES, *SOLAR HEATING, THERMAL PROPERTIES, THICKNESS, VIBRATION, SPACECRAFT, YAW, STRESS ANALYSIS, EXPERIMENTAL DESIGN, AERODYNAMIC STABILITY, DEFORMATION, ROBOTS, SHELLS(STRUCTURAL FORMS), TEMPERATURE GRADIENTS, SOLAR ENERGY, FEEDBACK, REFLECTORS, SATELLITE ANTENNAS, CLOSED LOOP SYSTEMS, FLEXIBLE STRUCTURES, PULSE MODULATION, TETHERING, THERMAL POWER PLANTS.

Subject Categories : Air Condition, Heating, Lighting & Ventilating
      Unmanned Spacecraft
      Spacecraft Trajectories and Reentry

Distribution Statement : APPROVED FOR PUBLIC RELEASE