Statics and dynamics simulation of a multi-tethered aerostat system
Date
2008-04-10T05:59:12Z
Authors
Zhao, Xiaohua.
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Abstract
A new radio telescope composed of an array of antennas is under development at the National Research Council. Each antenna includes a large scale multi-tethered aerostat system to hold the telescope receiver at the reflector focus. This receiver is located at the confluence point of the tethers. Starting from a previously developed dynamics simulation of the triple-tethered aerostat system, an existing statics model of the same system is incorporated into the simulation to provide an initial equilibrium condition for the dynamics. A spherical aerostat is used in both models. The two models show a very good match with each other after being merged together. This combined computer model is further developed to study the use of six tethers and the use of a streamlined aerostat instead of a spherical one. In the case of the six-tethered system, two topics were investigated: using the six tethers to control the position of the airborne receiver only; and using the six tethers to control the orientation of the receiver as well as its position. A streamlined aerostat is also modelled by a component breakdown method and incorporated into the triple-tethered system to replace the spherical one. The main findings from the simulation results are as follows: (1) the six-tethered system with reductions in the tether base radius and the tether diameter exhibited increased stiffness compared to the triple-tethered system when used to control the receiver position only; (2) the six-tethered system showed difficulty achieving satisfactory control for both the position and orientation of the receiver; (3) the streamlined aerostat showed no oscillations typical of a spherical one but the system requires more power to control in the presence of wind turbulence.