The Ada Resource Association
Ada Wires Landing Gear

Unmanned Air Vehicles

For the Swiss government, Ada software has replaced human pilots at the controls of two aircraft, Unmanned Air Vehicles (UAVs) and Remotely Piloted Vehicles (RPVs). They always needed a ground-based pilot for landing, because the accuracy of traditional positioning equipment was limited to about a hundred meters. This distance is insufficient for an automatic process.

With Ada, however, the Swiss have overcome that limitation. Using a compiler system from DDC-I, Inc., the Swiss Federal Aircraft Factory (F+W) in Emmen has developed an Automatic Landing System. The accuracy of the new system is now within about two meters and thus allows for fully automated landings.

What's a RAPS?

The RPV Autoland Position Sensor (RAPS) is a major part of the autolanding system. During the approach, RAPS continuously measures the dynamic position of the RPV in azimuth, elevation, and range. The values are transmitted to the Ground Control System (GCS) and used as feedback in the autoland servo-control loop. The RPV can thus be corrected and guided along a predetermined landing path. RAPS consists of a tripod with a motorized sensor platform and an electronic unit. The equipment is deployed in close vicinity to the landing field. Video and computer communications to and from the GCS are provided by means of a fiber-optic Link. The RAPS can be fully remote-operated from the GCS.

How does a RAPS work?

On the sensor platform, a laser-radar unit and a TV camera point to the approaching RPV. The RPV is illuminated by infrared light pulses; these are echoed back to the RAPS. Using these echoes, RAPS determines the RPV distance as well as azimuth and elevation angles. The TV camera gives visual information to the operator for monitoring the process. The position sensor is based on an Intel 80186 architecture, provided on a bare board by Gespac, Geneva, Switzerland. Papers describing the concept and the project will be available in both German and English from DDC-I.

For more information, contact:

DDC-I, Inc.
410 North 5th Street Suite 1050
Phoenix, AZ 85004
Phone: 602/275-7172
Fax: (602) 252-6054
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