Hi Zinefer,
You're right. Team 910 did build a miniature arm that exactly replicated the arm of the robot. It rotated 360 degrees at the base, the shoulder had 180 degrees of forward back travel, the elbow was almost 360 degrees of rotation, and the gripper switch had 3 positions (open, loose, tight).
The operator moved the small arm (each joint being about 6 inches) in 3D space, and the robot copied the movement exactly. It used PID control so that if you made a quick move, it raced to keep up. Closest way to imagine it is how a cursor follows your mouse movement, only in 3D. We also built a 3 tier rack that had shelves that corresponded to each of the three levels of the spider legs. The operator could put the arm on a shelf and it would place the arm at the exact height necessary to reach over a leg and then drop the tube.
We also supplemented the controls with buttons for ground loading, wall loading, jogging left/right, locking the shoulder in place or freeing up left/right shoulder rotation, and three buttons for semi or full automatic capping on all three heights (low,mid,high) using our autonomous code. That last feature we didn't implement until the off-season, but with our autonomous cranked up to hyper speed (4 seconds to drive 13 feet, score and release a tube) it made it pretty fun to hit that button and blast a tube on! Especially with a spoiler onto the back side of the rack at the end of a match.
We also won an award for the design, the Xerox Creativity Award at Western Michigan. Such fun!
Take care!
