Pegasus: Development of Guidance and Control System for Autonomous Parafoil
This research addressed the development of the guidance, navigation and control (GN&C) system for an autonomous high-glide-ratio parafoil-based delivery system (Fig.A). This effort continued research and development undertaken during the design of Affordable Guided Airdrop System (AGAS). The goal was to develop GN&C system allowing parafoil to track certain predetermined trajectories. That was to be done based on approximately the same onboard sensor suit as that of the AGAS. Within the frame of this research:
- a 6DoF model of 500-lb parafoil (developed by FXC Corp., Santa Ana, CA) was developed and rigorously tested;
- a software tool allowing rapid prototyping of optimal descent trajectories was created;
- a control system allowing tracking inertial reference trajectories in presence of uncertainties and disturbances was designed and tested in simulations.
Figure A. Two configurations of the PEGASUS.
Figure B below presents some of the model identification results when different criteria were used to match the model with the real drop data.
Figure C shows the variety of inertial trajectories that can be generated for the following tracking. Finally, Fig.D demonstrates a result of one of the Monte-Carlo runs proving the robustness of the developed tracking algorithm.
Figure B. The family of parafoil trajectories optimized with respect to different matching criteria.
Figure C. Examples of inertial reference descent trajectories.
Figure D. Simulation results of the trajectory tracking control system.