Multivariable Control Law Analysis For A Large Space Antenna

1987 ◽  
Author(s):  
Dale F. Enns ◽  
Daniel J. Bugajski
Keyword(s):  
Multivariable Control ◽  
Control Law ◽  
Space Antenna ◽  
Large Space

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

Friction Control for Vibration Suppression

1999 ◽  
Author(s):  
L. Gaul ◽  
R. Nitsche
Keyword(s):  
Normal Force ◽  
Vibration Suppression ◽  
Piezoelectric Element ◽  
Friction Model ◽  
Space Structures ◽  
Control Law ◽  
Large Space ◽  
Normal Contact ◽  
Friction Control ◽  
Frictional Interface

Abstract Friction damping in bolted joint connections of large space structures turned out to be a major source of damping (Gaul and Bohlen, 1987). For vibration suppression, the joints are designed such that the normal force in a frictional interface is controlled which improves damping performance. The use of active control to vary the normal contact force in a joint by means of a piezoelectric element is explored. A model consisting of two elastic beams connected by a single active joint is considered. A friction model with velocity dependent dynamics is used to describe the friction phenomena. A control law for friction dampers which maximizes energy dissipation instantaneously by controlling the normal force at the friction interface is proposed. The effect of displacement- and velocity-induced friction dynamics is considered for the design of the control law. We arrive at a dynamic controller which prevents frictional energy stored as potential energy in a bristle model from being returned to the system.

Static Shape Determination and Control of Large Space Structures: II. A Large Space Antenna

1984 ◽  
Vol 106 (4) ◽  
pp. 267-272 ◽  
Author(s):  
Connie J. Weeks
Keyword(s):  
Adjoint System ◽  
Performance Criteria ◽  
Space Structures ◽  
Space Antenna ◽  
Large Space ◽  
Solution Algorithms ◽  
Large Space Structures ◽  
Shape Determination ◽  
Control Forces ◽  
And Control

An integral operator approach is used to derive solutions to static shape determination and control problems associated with large space structures. Problem assumptions include a linear self-adjoint system model, observations and control forces at discrete points, and quadratic performance criteria for the comparison of estimates or control forces. Solutions reduce to the solution of linear equations of dimension on the order of the numbers of observations or control forces. Results are illustrated by simulations with a finite element model of a large space antenna. Modal expansions for terms in the solution algorithms are presented, using modes from the static or associated dynamic model. These expansions provide approximate solutions in the event that a closed form analytical solution to the system boundary value problem is not available.

scholarly journals Deployment Dynamics of Large Space Antenna and Supporting Arms

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 69922-69935 ◽  
Author(s):  
Shaolin Lu ◽  
Xiaozhi Qi ◽  
Ying Hu ◽  
Bing Li ◽  
Jianwei Zhang
Keyword(s):  
Space Antenna ◽  
Large Space ◽  
Deployment Dynamics

Multivariable control law design for a tailless airplane

1996 ◽  
Author(s):  
Anhtuan Ngo ◽  
William Reigelsperger ◽  
Siva Banda ◽  
John Bessolo
Keyword(s):  
Multivariable Control ◽  
Control Law

Dynamics and control of a large space antenna

1984 ◽  
Vol 7 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Shyh Jong Wang ◽  
Jonathan M. Cameron
Keyword(s):  
Space Antenna ◽  
Large Space ◽  
Dynamics And Control ◽  
And Control

Robust control of a large space antenna

1987 ◽  
Author(s):  
MICHAEL BARRET ◽  
DANIEL BUGAJSKI
Keyword(s):  
Robust Control ◽  
Space Antenna ◽  
Large Space
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