Technology Review - Published By MIT
Advertisement

Flights of Fancy

Continued from page 1

By Megan Vandre

April 2003

smaller text tool iconmedium text tool iconlarger text tool icon

To gather the data that direct the helicopter during automated flight, Shterenberg and Gavrilets outfitted the craft with a custom-built data-acquisition box. Remote-control helicopter pilot Raja Bortcosh led the chopper through myriad maneuvers, and the box recorded his commands and the helicopter's sensor outputs. "Using that data," Gavrilets says, "we were able to reconstruct the way the pilot directs the helicopter to perform the maneuvers. And then we were able to build the first dynamic model-mathematical model-of the helicopter in aerobatic flight, which had never been done before." Once they had reconstructed the flight commands as mathematical equations, the researchers-joined by postdoctoral associate Bernard Mettler, aeronautics and astronautics graduate student Ioannis Martinos, and electrical engineering and computer science graduate student Kara Sprague '01, MEng '02-programmed the information into Mr. Chopper's computer, allowing the machine to duplicate the maneuvers on its own.

Mettler, whose doctoral research at Carnegie Mellon University focused on modeling and control techniques for miniature helicopters, notes that it takes years to become proficient at controlling a helicopter, so it's not easy to duplicate these skills with a computer. "The MIT autonomous helicopter group, by successfully executing aerobatic maneuvers, achieved a new state of the art in flight performance under computer control," he says.

To test their mathematical models, the researchers built a flight simulator with a duplicate avionics box and interface. Through the simulator, they can watch a 3-D image of a helicopter move wherever their models direct it. The team tries to eliminate all mathematical inaccuracies on the simulator before it tests the commands with the helicopter.

On the field, with the selected mathematical algorithm programmed into the helicopter, the pilot controls the chopper as it takes off from the ground. Directing it to hover at a specific location and altitude, the pilot flips a switch that puts the helicopter on autopilot. The helicopter follows the instructions of the algorithm and performs the maneuver within prescribed parameters of altitude, speed, and distance, and all the while, the researchers monitor its flight data on the ground computer. After completing the maneuver, the chopper returns to its hovering position, and the pilot takes manual control and lands the chopper.

Thanks to the simulator and the researchers' ability to test the mathematical models before taking to the skies, the helicopter has crashed only twice in its four-year history, despite the fact that, as Feron says, "the windows for making mistakes and recovering from them are extremely narrow." Both crashes were attributable to hardware failures, not numerical errors.

Comments

Log In

Forgot your password?     Register »
Advertisement

Videos

Laser-Triggered Chemical Reactions
Featured Content
Sponsored by:
White Papers

Twelve ways to reduce costs with SQL Server 2008
Find out how to reduce costs and get more efficient

Download

Total Economic Impact of SQL Server 2008 Upgrade
Forrester reports on increasing productivity and management capabilities

Download 

Achieving Cost and Resource Savings with UC
How Office Communications Server R2 and Exchange Server can make your business smarter and more efficient

Download 

The Compelling Case for Conferencing
Read how you can improve workload support and find IT efficiencies

Download

How Windows Server 2008 R2 Helps Optimize IT and Save you Money
Read how you can improve workload support and find IT efficiencies

Download

Windows Server 2008 R2 Hyper-V Live Migration
See how Windows Server 2008 R2 and Hyper-V enable virtualization and Live Migration

Download
Advertisement
Subscribe to Technology Review's daily e-mail update. Enter your e-mail address

TECHNOLOGY RESOURCES
Advertisement
MIT Massachusetts Institute of Technology © 2009 Technology Review. All Rights Reserved.