Through CHARLI’s eye

A screen capture from the perspective of CHARLI

"Look into my eye."

The above image is a screen capture of what CHARLI sees as he is on the soccer field, ready to kick the ball. The reddish-dot is the orange soccer ball, the yellow, the goal posts. CHARLI’s sight – along with the DARwIn-OP robots, and all the robots here -- is color-based, and he is programmed to autonomously recognize and base his actions upon selected colors, for seeking, kicking and goal-orientating. He has three main colors to recognize: The green of the playing field, the orange of the soccer ball, and the yellow of the field goal. 

“We tell him what colors are what using color table software, and basically he looks at the number of clusters with the color and the shape of the cluster, and then he decides, “Ok, this is the ball, and there’s the goal,” says Jack Newton, a rising senior in computer engineering from Blacksburg. “And he’ll line up and kick it.” 

Any bright blue, orange, red, or yellow off the field – such as the shirt of a spectator -- can throw a robot’s visual orientation off, depending on the robot. The DARwIn bots are programmed to look for a blue goal post, so if a person, say a photographer, wears blue jeans, he can be mistaken for a goal as both shapes would be blue, roundish and vertical. That’s why nearly all of the RoboCup participants opt for all-black attire. Other colors, such as black, or white, or gray, are received as noise, looking quite similar to static on a television set, or a black cut-out figure of empty space. 


Blue doesn’t matter for all the robots. In CHARLI’s case, he’s always kicking toward a yellow goal post as Adult-Sized League robots play single-goal kick soccer. So blue jeans, or a blue shirt, would show up as the same static. (We have yet to see anyone sport yellow pants.) 

Also forbidden near the soccer fields: Flash photography as the burst of light can confuse a robot’s sense of visual environment. Anyone who has been blinded by a flash during a performance or talk might agree.