Autonomous Landing at Unprepared Sites for a Cargo Unmanned Air System

A rapid prototyping simulation for the Autonomous Rotorcraft Land & Take-Off (ARLTO) system will be developed to analyze and evolve requirements for the landing and take-off of a Rotary-wing Autonomous Air Vehicle (RAAV) from unprepared terrain. The simulation is based upon the Task-Pilot-Vehicle modeling system and features a UH-60 configured with a Sliding Mode Control (SCM) inner loop closure. The baseline image sensing subsystem is a state-of-the-art electro-optic/infrared subsystem featuring color CCD TV, low light ECCCD TV and a laser rangefinder. The mission design is based upon the covert drop-off/pickup of cargo at a specified location accomplished in a GPS denied environment using a-priori geophysical digital elevation information and other data when available. The system uses passive sensing to minimize detection. Technical staff of the Jet Propulsion Laboratory (JPL) will assess the feasibility of interfacing the image sensor system with existing JPL image processing capabilities for terrain relative navigation and hazard detection and avoidance in the landing task. The ARLTO simulation is extensible to include a range of rotorcraft including twin rotor and tilt rotors. The SCM controller structure has the potential of providing robustness to disturbances and the ability to compensate for obstacles around the unprepared landing site