Integrated control of thermally distorted large space antennas

The objective of this paper is to develop a control system design method that 1) recognizes the time dependence of the thermal distortion due to orbital motion and 2) controls variables that are directly related to far-field performance for Earth-pointing space antennas. The first objective is accomplished by expanding the distortion into principal components that are orthogonal in space and time. Actuator strokes become a linear combination of the time-dependent components. The spatial components provide a natural space in which to determine the optimal actuator locations and act as basis vectors for extrapolating sensor measurements to the entire antenna surface. The approach for the second objective is to expand the far zone electric field in a Zernike-Bessel series. The coefficients of this series provide a reliable measure of far-field performance and a natural cost function for designing the control system. The method accommodates tapered feeds and arbitrary polarizations. Simulations are performed for a geosynchronous radiometer to determine the effectiveness of the control system under variations in solar geometry, structure materials, and thermal properties.

[1]  Jeffrey T. Farmer,et al.  Thermal-distortion analysis of an antenna strongback for geostationary high-frequency microwave applications , 1990 .

[2]  Raphael T. Haftka,et al.  Integrated structural electromagnetic shape control of large space anatenna reflectors , 1989 .

[3]  R. Noll.  Zernike polynomials and atmospheric turbulence , 1976 .

[4]  J. Ruze.  Antenna tolerance theory—A review , 1966 .

[5]  Emil Wolf,et al.  Principles of Optics: Contents , 1999 .

[6]  L. B. Garrett.  Interactive design and analysis of future large spacecraft concepts , 1981 .

[7]  R. Bansal,et al.  Antenna theory; analysis and design , 1984, Proceedings of the IEEE.

[8]  T. E. Horton.  Interactive Design and Analysis of Future Large Spacecraft Concepts , 1982 .

[9]  Raphael T. Haftka,et al.  An analytical investigation of shape control of large space structures by applied temperatures , 1985 .

[10]  J. A. Garba,et al.  Vibration Suppression For Precision Segmented Reflector Backup Structure , 1989, Defense, Security, and Sensing.

[11]  Raj Mittra,et al.  An efficient technique for the computation of vector secondary patterns of offset paraboloid reflectors , 1979 .

[12]  Jen-Kuang Huang,et al.  Integrated control of thermally distorted large space antennas , 1991 .

[13]  Carlos S. Kubrusly,et al.  Sensors and controllers location in distributed systems - A survey , 1985, Autom..

[14]  John H. Hardy.  Active Optics - Don't Build A Telescope Without It! , 1982, Astronomical Telescopes and Instrumentation.

[15]  Raphael T. Haftka,et al.  Selection of actuator locations for static shape control of large space structures by heuristic integer programing , 1985 .

[16]  J. Mahaney,et al.  Fundamental studies of thermal-structural effects on orbiting trusses , 1982 .

[17]  B. Moore.  Principal component analysis in linear systems: Controllability, observability, and model reduction , 1981 .

[18]  B. Parlett.  The Symmetric Eigenvalue Problem , 1981 .

[19]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .