Dynamics/Control of a Radio Telescope Receiver Supported by a Tethered Aerostat

Abstract

Canadian researchers have proposed a design for a new radio telescope consisting of an array of very large ree ectors. A largemultitethered aerostat will be used to support each ree ector’ s receiver. The length of each tether can be adjusted by ground-based winches, and active control is used to overcome the effects of wind turbulence on the aerostat. To aid in the system’ s mechanical and controller design, a computer model has been developed, including models of the tethers and the aerostat. Two types of aerostat have been considered: spherical and streamlined. A wind turbulence model is incorporated to provide disturbance to the system. Controllers are used to adjust the tether lengths based on feedback of the receiver’ s position. The model is used to optimize the control gains. We e nd that, with 50 kW available at each winch, it is possible to maintain the receiver’ s position within 85 cm of its desired location, even in the worst-case cone guration.