Building A Robotic Beckham
Making DARwIn Mobile
LabVIEW uses sensor inputs to create an internal feedback loop that controls DARwIn’s movements.
“Vision information from the cameras dictate DARwIn’s behavior – for example, walking up to the ball and kicking it,” says Egger. “His IMUs act like a human inner ear – they stabilize him by reporting the orientation and acceleration of his joints. LabVIEW uses that information to change the way he walks. If he’s starting to fall down or starting up an incline, we might make him roll his upper body forward or backward or lean to one side.
LabVIEW enables the team to work with DARwIn in several ways. They can tether him to a Mac and move him with keystrokes, control him with a wireless joystick, or record his actions in LabVIEW and repeat them. They can also create moves on the Mac.
“LabVIEW’s tools let us do 3D simulations in OpenGL,” says Karl Muecke, a PhD candidate in mechanical engineering who is the TEAM:SPRInt leader and the originator of much of DARwIn’s code. “We can simulate difficult maneuvers with no risk to the robot, then port the moves we like to DARwIn.”
DARwIn has powerful muscles to make his moves – 21 powerful maxon DC motors with distributed control, plus two DC servomotors for his pan/tilt camera.
Behind the Fun: The Serious Purpose of Robotics
The work at RoMeLa, which is part of Virginia Tech’s Mechanical Engineering Department, has serious objectives. Many of its research projects are funded by the National Science Foundation, the Office of Naval Research, the Jet Propulsion Laboratory, and the Defense Advanced Research Projects Agency (DARPA), and have well-defined goals. Scientists will eventually be able to use DARwIn to design and test artificial joints and other prosthetic appliances rather than human subjects.
RoMeLa is primarily a research lab for graduate students, and 14 of them work there, assisted by undergraduates. Mac predominates as the students’ platform of choice for running LabVIEW. Some students run Windows on Macs using Parallels or Boot Camp.
“We have iSight cameras in all our Macs,” says Hong. “We use them for group meetings in iChat, especially when I’m traveling to conferences.”
The RoMeLa group also uses Mac Minis for a variety of purposes. One is mounted on the ceiling of the lab and connected to an Apple Cinema Display in the building lobby. Looped Keynote presentations show animations and movie clips of current projects and achievements.
Ahead: A Life-Size DARwIn
Not surprisingly, Hong is never short of help for robotics projects. Word gets around about the kind of work going on in RoMeLa. “I get so many phone calls, emails, and knocks on the door from students who want to get involved,” he says. “People have fun learning here.”
Teams of graduates and undergraduates are working on what Hong calls “novel locomotion strategies.” DARwIn, on the other hand, originated as a research project in how humans walk – a locomotion strategy that is distinctly pedestrian. He will ultimately emerge as a life-size humanoid with the same proportions and range of motion as adult humans: picture eleven Mac-programmed DARwIns in soccer uniforms. RoMeLa is committed to making it happen.