Innovators at NASA's Armstrong Flight Research Center have developed a flight control system that allows an aircraft to maintain an attitude and heading within 5 meters of a desired position. In its current implementation, the Platform Precision Autopilot (PPA) is a digital system that augments the legacy analog Gulfstream III (G-III) autopilot system. The PPA consists of an embedded microcontroller-based flight computer and navigation algorithms that use externally provided attitude and differential global positioning system (GPS) information to generate aircraft control commands. The technology was developed for NASA's Unmanned Aerial Vehicle Synthetic Aperture Radar (UAVSAR) program to aid in precise, repeat-pass scientific missions. This real-time navigation tool communicates via a controller area network (CAN) to either a laptop station or an embedded display for cockpit use (see Figure 1). A novel approach to a digital-to-analog (DAC) converter allows the controller to have a wider output range with increased precision, and it allows incorporation into the G-III autopilot by imitating the output of an instrument landing system (ILS). Because the software is autocoded entirely in Simulink® block diagrams, it can be adapted for use in applications requiring precision navigation, such as surveillance or terrain mapping.
Simulink is a registered trademark of The MathWorks, Inc.
Figure 1. Platform Precision Autopilot system architecture › View larger image
- Precise navigation: Controls an aircraft within a specified tolerance, despite aircraft system noise and nonlinearities, pilot throttle adjustments, and light turbulence
- Low power: Operates at less than 5 Watts
- Compact: Measures 3x5 inches
- Flexible: Uses Simulink block diagrams, enabling modification for other uses
- Novel: Features a unique use of a CAN system and design interface that imitate an ILS approach
- Proven: Has been actively flying on Armstrong's G-III aircraft for more than 5 years
- Scientific and military surveillance
- Terrain mapping
- Formation flight
This technology is part of NASA's technology transfer program. The program seeks to stimulate broad commercial use/application of NASA-developed technologies. NASA is flexible in its agreements, and opportunities exist for licensing and joint development. Armstrong is interested in a partnership to commercialize this technology.
If you would like more information about this technology or about NASA's technology transfer program, please contact:
Technology Transfer Office
NASA's Armstrong Flight Research Center
PO Box 273, M/S 1100
Edwards, CA 93523-0273
Phone: (661) 276-3368