Application of a Smart Parachute Release Algorithm to the CPAS Test Architecture

摘要

One of the primary test vehicles for the Capsule Parachute Assembly System (CPAS) is the Parachute Test Vehicle (PTV), a capsule-shaped structure similar to the Orion design but truncated to fit in the cargo area of a C-17 aircraft. The PTV has a full Orion-like parachute compartment and similar aerodynamics; however, because of the single-point attachment of the CPAS parachutes and the lack of an Orion-like Reaction Control System (RCS), the PTV has the potential to reach significant body rates. High body rates at the time of Drogue release may cause the PTV to flip while the Pilot parachutes deploy, which may result in the severing of Pilot or Main risers. In order to prevent high rates at the time of Drogue release, a "smart release" algorithm was implemented in the PTV avionics system. This algorithm, which was developed for the Orion flight system, triggers the Drogue parachute release when the body rates are near a minimum. This paper discusses the development and testing of the smart release algorithm, its implementation in the PTV avionics and the pre-test simulation, and the results of its use on two CPAS tests.