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Strategy
The method of programming the robot was to decompose the required tasks into separate states. For example, several states were required to pick up and drop off the can, find lights for the refueling stations, and collect golf balls.
An IR sensor was used to locate the can and pick it up. The robot spun in a circle until the IR sensor found the presence of the can directly in front of the robot. The robot then moved forward until a second IR threshold was reached, and a sequence of programmed states caused the robot to close and lift the gripper.
LADAR was used heavily in motion control of the robot. By analyzing the signal echoed from its lasers, the LADAR calculated distances between the robot and its surroundings. This was used in coordination with a Kalman filter, which facilitated moving the robot to specified locations within the course. Additionally, the LADAR was used in the can dropoff sequence; it was used to determine how far the robot is from the front wall, so the can could be placed at an appropriate distance behind the designated drop line.
Camera vision was used to locate golf balls, determine their colors and locations, and pick them up and drop them off. The camera output was thresh-holded to locate only orange and blue golf balls, while cropping out upper portions of the camera image so as not to allow overhead lights or other objects to interfere with golf ball pickups.
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