Robotics Challenge 2: Building the Tests

As a mentor for the local 4H team (Team Facebook Page), I spent a couple weeks helping the kids build wooden mock ups of the challenges they'll be facing in six weeks. We started with the official FIRST specs and showed the kids how to build a bill of materials for a project. Several of the mentors donated lumber and the team paid for any hardware that remained. Adults ran the table saw for the huge pieces of OSB, but always had a team member in goggles spotting. Otherwise, the kids did the measuring, marking, jigsawing, drilling, screwing, etc.  

This year's FIRST challenge has a medieval theme, where robots cross elaborate defenses in order to launch "boulders" at the opponent's tower. The upper windows are high goals with 5 points each and the lower archways are worth only 2 points each. Therefore, that was the first aid we needed. Unlike the high-school team, we meet in a residential basement, so we can't build the whole 9.5 foot tall, 4 four wide beast. I had to break it apart into segments, each 3 feet high in order to fit into a van when we take our show to the county fair. This also meant limiting the upper two stories to one side each.
We were quite proud of the craftsmanship of the lower floor, but didn't take time for photos. Here is a snapshot from the FIRST video above. Note that those LED lights are $895 for a string of 50. We won't see the real things until the tournament in Duluth.

The upper window of ours it detachable so that our camera team can play with it. The box around the bottom is a special 3M reflective tape that can be used for machine vision. Our robot will aim for the box when shooting. Our camera (connected up to my computer in this instance) is surrounded by a bright green ring of lights to make the tape a specific color from our point of view.

Next, we constructed the enemy "defenses", the obstacles our robot has to be able to overcome. We built one 2 foot by 4 foot hold with the ramps on each side and drop in each of the eight choices : moat, rock wall, rough terrain, ramparts, portcullis, etc. Since the portcullis is six feet tall and we ran out of room in the storage shed outside, we decided not to build the elaborate metal drawbridge or sally port. The local high-school team (with 30 members) graciously offered to let us borrow theirs.


My favorite obstacle was the "cheval de frise". This sounds too much like a type of poodle, so we call it the see-saw. The others, our design could breeze over. We even had minor shock absorbers in case we became airborne on the ramps. However, the see-saws would require a manipulator arm to lower the left center board so we can slowly drive over the three boards on the left.

Because we couldn't build any more, I turned my obsessive thoughts to the game manual and points of strategy. As a former tester and gamer, I knew that every rule system had loopholes and sweet spots.