Periodic Optimal Control of a Towed Aerial-Cable System in Presence of Cross-Wind
Paul A. Williams · AIAA Guidance, Navigation, and Control Conference and Exhibit · 2006
*Aerial tethers have been proposed over a number of years to provide a means for deploying or retrieving payloads from the ground via an aircraft. The development of such a system could potentially allow extraction of supplies or injured personnel for wartime or peacetime support. The dynamics of aerial tethers towed in circular paths by an orbiting aircraft have been studied extensively. Typically, the atmosphere is assumed to be stationary with respect to the ground so that stable steady-state solutions are possible for certain combinations of system parameters. However, the presence of a cross-wind causes the cable tip to oscillate in the vertical plane and move away from the typical equilibrium position obtained for no cross-wind disturbances. This paper presents a numerical study of an constrained, optimally controlled system for minimizing the disturbance at the tether tip by a combination of towpoint manipulation and tether reeling.