Today was our second design review. We invited back JPL engineer Mr. Feldmen and Mr. Zarcara from Caltech to judge our robot and our implementation of the designs we spoke about at our last review.
We explained our use of the coin sorter we had shown them at our previous review, and how we were never able to build a linkage that could complete the task of scoring in the lander. Once we finished catching them up on our design, we began to explain the problems we were experiencing and what we could do to solve them.
The first thing we wanted to address was the issue we had with the harvester and how it would sometimes make the minerals fall right out of the robot rather than depositing them into the sorter. We explained that we had suspicions that the sorter could be at too little of an angle and was simply causing the mineral to hit the first mineral and bounce out. After debating about it, we decided to test the robot and observe what would happen. We found that several times, the mineral would shoot out of the harvester very quickly as a result of too much power by the zip ties. We came to the conclusion that the simplest solution would be to simply make the top layer of zip ties shorter, reducing the amount of surface area hitting the mineral on the way out.
Minerals stuck under robot:
Another problem we brought up was the issue of getting minerals stuck under the robot. We showed them a demonstration of this and the scenario that causes this problem. After observing the problem, we found that there was no easy solution to the problem, just ways as to how we could prevent it from happening. We found that by going over the crater very slowly in the beginning of a match, we would be able to slowly descent upon the minerals and push them away from the edge of the crater. This helps us because the edge of the crater is the number 1 spot where we would get minerals stuck under the robot.
Trouble going over crater:
Another issue we had encountered with the current version of our robot was an occasional difficulty clearing the crater. After driving and observing the issue, we found that the problem was a result of bad alignment with the crater. In other words, whenever we would try to go over the crater at an angle, the robot would have trouble going over it. This was thanks to the front of the robot that had particularly low clearance. Mr. Feldmen and Mr. Zarcara both agreed that the easiest solution to this would be to simply cut the part of the robot that was too low. After doing so, we found that we had much more mobility going over the crater and were able to clear it more efficiently. We decided to update our CAD model immediately so our next cut would have the adjusted panels.
Ultimately, we found the solutions to our problems and also received constructive criticism from professionals in the engineering field.