SBIR-STTR Award

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

Benefit:
The anticipated benefits of the research include: The preliminary identification of the major technical risks in the integration of a state-of-the-art Electro-Optical/Infrared (EO/IR) sensor system with existing JPL image processing software. A preliminary assessment of the expected performance of existing JPL terrain relative navigation and hazard detection and avoidance functions when applied to data from the EO/IR sensor system. The preliminary development of a simulated, prototype LTO flight controller capable of safe operation in the One-Wheel-On-Ground/All-Wheels-On-Ground/Flat-Pitch-On-Ground flight segments governing touchdown on sloped, unprepared terrain. An assessment of the ability of the Sliding Mode Control inner loop controller of the RAAV to provide robustness to disturbances and the ability to compensate for obstacles around the unprepared landing site. The proposed ARTLO system design concept has the potential for providing significantly greater autonomy, reducing the active sensing signature and requiring minimal landing zone support compared to state-of-the-art systems currently under development such a the Boeing Hummingbird and Northrop-Grumman Firescout. The ARLTO capabilities are directly applicable to a broad range of national defense, homeland security, search and rescue and local police missions that are best supported by rotorcraft.

Keywords:
Navigation, Navigation, Hazard, landing, Autonomous, Rotorcraft, detection, Terrain

The program will develop a prototype Autonomous Helicopter Rugged Operations Controller (AHROC) supporting autonomous approach, landing, takeoff, departure and navigation in sloped, rugged terrain in a GPS denied environment. The AHROC system utilizes dual color camera inputs. Passive image processing functions provide: 1) Aircraft localization using a reference digital elevation map, 2) The generation of dense megapixel structure of the environment including ground cover at rates exceeding 1 Hz for precise helicopter control, 3) Landing hazard assessment for sloping, rugged terrain with dense ground cover. The systems landing/take-off controller enables landing on terrain with uncertain surface characteristics; it mitigates dynamic rollover by thrust modulation and thrust vector stabilization and senses skid sinking and entrapment. The system development will be conducted in the sloped, rugged terrain surrounding the Santa Ana Canyon, Redlands, CA using a Bell 206. A human pilot flies the AHROCs realtime flight director type output; this enables rapid and economical system development, test and demonstration. Since the system is passive it has a low probability of detection; it is also simple, low cost and reliable. The AHROCs capabilities and attributes meet many of the low altitude objectives of the USMC Unmanned Air Systems (UAS) cargo truck 0x9D concept.

Benefit:
The Phase II/Phase II Option development will provide: 1) A suite of high throughput passive image processing algorithms that support: a) Localization of the position of the system through correlation with three-dimensional features of the surround, 2) The generation of dense structure (megapixel) models of the surround at rates exceeding 1 Hz necessary for dynamic systems control, 3) A rotor thrust control system to mitigate helicopter dynamic rollover when landing/taking-off from sloped, rugged terrain, 4) An algorithm to generate safe landing/approach trajectories to a target based upon dense structure models of the local surround. These capabilities have obvious applicability to commercial autonomous helicopters and flight vehicles in general; however the building-block image processing capabilities can also be employed in ground as well as airborne applications. Furthermore, these same capabilities can be used to develop flight safety devices for manned flight systems which have a significantly larger market potential. Potential commercial add-on avionics safety products include: 1) A helicopter dynamic rollover mitigation system, 2) A synthetic visual (approach/landing/take-off/departure) aid to improve flight safety by: a) Providing repeatable approach and departure decision parameters, b) Extending precision approach capabilities to unprepared sites in hilly and mountainous terrain, urban buildings, moving 0x9D platforms such as high rise buildings, oil drilling platforms, military and commercial ships and c) Minimizing or mitigating the visual illusions and mis-perceptions that can arise when viewing the approach or departure scene under the range the environmental conditions.

Keywords:
Autonomous, Hazard, Classification, passive, Terrain, landing, Navigation, Rotorcraft