More Information on the HUMMINGBIRD Project

Helicopter Statistics

Body Size	60
Body Length	62 inches
Rotor Diameter	61 inches
Overall Weight	46 pounds
Engine Size	2.76 cubic inches
Engine Power	4.75 HP
Navigational Sensors	TANS Vector Differential Carrier Phase GPS

Current Capabilities

Dynamic Target Tracking and Following
Servoing from Vision Feedback
Autonomous Hover, Trajectory Following, and Landing
Object Location and Identification using Vision
Ferromagnetic Disk Retrieval

Future Capabilities

Autonomous Take-Offs
Parallel Camera Stereo Vision
Motion-Based Stereo Vision
Real-Time User Interaction
Human-Robot Team Mission Tasks

Global Positioning System

One of the greatest problems with controlling an autonomous helicopter is sensing position and attitude. Since a small, inexpensive vehicle is being used, it has neither the payload nor the financial budget to use exceedingly high quality inertial guidance systems. Navigation using differential carrier phase Global Positioning System (DCPGPS), is an active area of research within ARL, and offers an practical solution to these problems.

The Global Positioning System is an excellent sensor offering a wide variety of configurations. In its normal civilian configuration, it provides accuracies of roughly 100 meters in both position and altitude. Various (mainly differential) methods have been proposed and implemented for increasing this precision to about a meter. Stanford's use of carrier phase measurements allow accuracy on the order of centimeters. When carrier phase techniques are used in conjunction with multiple antenna, vehicle attitude can also be determined.