I am requesting a clarification to SG2 - Robot Expansion.
I am not looking for a resolution for our team, our season is complete. I am looking for an official clarification on a rule interpretation so that teams in any remaining regional/state/national tournaments or Worlds do not get into the same discussion with judges that we did yesterday at our state championship.
After the first qualification match in a State tournament, we were warned that our robot was making an illegal expansion to climb on the platform and therefore we could not legally get on the platform and would be disqualified if we went on the platform again in the same manner. The students appealed to the head judge and the judgeâs ruling was upheld.
Background:
Robot is a 6 wheel design that has a âtailâ that is mounted to the back of the robot on a pivot. At the start of the match, the tail is in the up position tucked against the back of the robot to fit inside 18" cube. It is possible for the tail to rotate 180 degrees down which lifts the back wheels off the ground. However, no matter what angle the tail is at (between full up and full down), the height of the robot never exceeds 18â as measured on a âflat planeâ per . Please refer to âOn Tech Table (Flat Plane)â image below.
The robot climbs the platform by driving up to it and the front two or four wheels climb up on their own. The tail is then dropped which pivots the robot onto the platform and the tail is then raised back up. Please refer to âClimbing Platformâ image below.
Text (excerpt) of
The 18â height limit specified by refers to the Robot height when it is placed on a flat plane, such as a field tile or an inspection table. An 18â tall robot which tips slightly while climbing a Platform would still be legal.
Oâur interpretation of the rule:
When the tail drops, the robot changes configurations from one legal position to another (remaining legal during the process). By the wording of the rule, in any stage of the process below, if the robot were removed from the situation and placed on a flat plane, it would be just as legal as it was on the Tech table at the beginning of the day. Please refer to âOut Understanding of Rule SG2â image below.
Judges Ruling:
When the robot pivots forward onto the platform with the tail still down, it is now sitting on a âflat planeâ. That plane is horizontal and so a measurement perpendicular to it in the vertical direction results in a height greater than 18â and is therefore an illegal expansion outside the expansion zone. Please refer to âJudges Ruling on Rule SG2 Applicationâ image below.
Our Position:
The judges ruling was incorrect as it arbitrarily defined a flat plane for the purposes of height measurement on and in plane with the platform when our robot was not yet fully on the platform. The robot was still in a legal configuration and tilted as it continued to climb the platform.
- The rule is clear that the measurement is to be made as the robot sits on a flat plane. At the point where the robot tilts forward and the front tires land on the platform, the judgeâs position is that we are now fully on the platform and therefore he defines a new temporary horizontal measurement plane on the platform to rule the robot illegal. If at that moment, we were to pick the robot up from the platform and set it on a floor tile in the exact same robot configuration, the robot would be legal.
- It is our clear position that at the moment the robot falls forward onto the front tires, the robot is in a legal configuration and is NOT yet fully on the platform, but is still tilted in the process of climbing the platform. While the robot âappearsâ to be sitting level because this is how it often sits when on the floor tiles, it is no as it is in a different configuration. Therefore the robot expansion measurement should be considered in a tilted state where it is clearly legal.
- A robot that is in a configuration that is legal on the tech table cannot become illegal on the field because of its orientation.
We are asking for an official ruling on the legality of this design so that teams going forward to remaining state, regional, national or Worlds competitions have a clear understanding on how to apply the rule.
Thank you.
P.S., if you wish to see video of our robot climbing the platform, please search â10930D / error 404â on YouTube - select video âLulu Rocks!â and move to 0:30 in video.