I'm trying to make a robotic bottle cap opener. Basically a robotic arm with two "claws". An outer claw with a wider grasp to keep the bottle in place, and an inner claw that can rotate to unscrew the cap. The task of the robot is to locate the bottle, center the arm at the center of the bottle, and then move down until a touch sensor near the inner claw touches the cap, the outer claw should then tighten around the bottle and the inner claw should tighten around the cap.
While it's relatively easy to describe what this robot should do, it's much harder to actually make a robot that can do it. The ultrasound sensor it too inaccurate to use for locating for bottle, so I was thinking of using a camera mounted on the arm that will see the table, where the bottle is located, from above. I've tried taking some pictures of what that might look like and I've managed to do some test image processing to locate the cap as it's just a circle, at least if the camera is positioned right. Anyone else have any other suggestions for locating the bottle?
I think I probably need another NXT set to get enought motors both for moving the arm, gripping the bottle and unscrewing the cap.
Anyone have suggestions? Anyone tried anything similar?