摘要：AbstractThe Crew Module Atmospheric Re-entry Experiment mission is a suborbital mission of flying Crew Module (CM) as the payload in a parent launch vehicle. After separation from the launcher, Crew Module (CM) performs suborbital re-entry flight from an altitude of 126 km. The module is actively controlled from the instant of its separation from the launcher up to the point of re-entry into the atmosphere at 80 km after which it follows a ballistic flight through the atmosphere. Three axis control with Reaction Control System (RCS) is envisaged during exo atmospheric descent to damp out the rates and ensure near zero degree angle of attack at re-entry. This paper gives different attitude control schemes proposed for the mission using RCS thrusters. The control strategy is based on proportional derivative controller with a modulator. The design techniques for different modulation schemes are discussed. Simulations results of crew module attitude control are also presented to demonstrate the obtainable performances from different modulation schemes.
关键词：KeywordsAttitude controlReaction Control SystemPulse Width ModulationPulse WidthPulse Frequency modulation
