Guided Payload Recovery by a Parafoil System

摘要

Parafoil systems have been studied for precision release of airdropped payloads, mainly in military scenarios; this concept has been extended to aerospace applications. Since 1993 NASA has performed flight tests of a deployable precision landing system for spacecraft recovery, and the project NASA X-38 was developed for safe landing of rescue reentry capsules carrying human crews from the International Space Station. In Russia and Japan automated payload recovery systems using parafoils have been proposed. More recently a project, called Alex, has been developed in Europe for an autonomous guidance system tailored to parafoils. This paper is concerned with autonomous generation of optimal trajectories for parafoils. A conservative steady-state analysis of optimal descent paths leads to simple conditions on control variables. The resulting guidance strategy is easy enough to be implemented in real time, and an adaptive guidance scheme is developed and discussed.