6.270 2006: SNAKES ON A PLANE



Team 28: HOT CREW!!!




The Front View

The Side View




Oliver Yeh, Herman Mutiso and Tuan Huynh                                   



Just in case you are wondering, the first word in ‘HOT CREW’ is a combination of our first name initials  J



 At the beginning of IAP, we were 'sure’ what we wanted the robot to look like. By the time it was impounded, the little machine had undergone more changes in its overall structure than one would care to recall.

The end product was an artificial 'cheetah', a machine built to traverse the board's terrain at breakneck speed.


Although built with a gear ratio of 75:1, we opted for a unique bracing style: instead of mounting small lego piece after small lego piece, it was decided to rely on longer beams to hold the robot together. End result: one light-weight, lean machine that moved at lightning speed. So fast was this...this...fiend from hell that we had to run the motors at half speed in order to keep track of it.

The Gear Train


The extra wheels (‘un-rubbered’ ones) were designed to serve a three-fold purpose. One, act as bump sensors; in case we bumped into walls or opponents' robots, two: prevent the beams that were attached to the bump sensors from constantly scraping against the ground and three; act as a snake-collector (doesn't this remind you of the movie: the bone collector, with that good looking actress, what was her name again?). By snake collector is meant a pushing device that was meant to collect the snakes and place them in the hills.


Other than the bump sensors, team 'hot crew' also made use of a distance sensor as a means of orienting itself, unlike most teams which made use of infra-red sensors. This is how it worked: There are four unique combinations for four different possible starting positions.  The sensors were hugely inaccurate and it was only possible to tell if an obstacle was very far away or very close. Our code directed the happy board to treat distance sensor readings of 2150 or below as 'far' and 2151 or above as 'close'. Using this, the ‘bot could figure out which direction to take in order to get to either the two snakes or the four snakes. 



Complex strategies greatly increase the number of things that can go wrong and make it increasingly difficult for the robot to work consistently. With this in mind, we decided from day one to adopt a simple strategy and spend most of the time ensuring the 'bot moved predictably and consistently. Little did we know how much time we actually had.


The approach was to dash across the length of the board, trap the four snakes and leave them in the hill at the opposite side of the board, before going for our other 2 snakes and placing them in the center hill. We reasoned that it would be remarkably harder to score in the hill at the center than at the other 2 hills. So if we scored in the central hill, we would almost be guaranteed of one scoring zone.  Since our robot was one of the fastest, we could get through these two stages of our strategy before our opponents could get to part two of their strategy.


Lastly, the robot would go to the last scoring zone, clear all the opponents' snakes and remain there, patrolling the region to ensure that the opponents' 'bot did not manage to win the region. This meant that unless the opponent ‘bot could clear the hill in which we had placed our four snakes and then place their four snakes in the central zone, then we were practically assured of victory. 



I always believed firmly in the idea that its the effort that counts.  We gave the robot our best shot and sold our time for the advancement of it.  But alas, we could not collect the fruits of our labor.  We were part of the 1/4 of the teams who went two and out.   In our first match, we were disqualified because of our 60 second code did not work. In our last match, our robot did an very interesting move.  Because of its anti-stuck codes, it would move forward and backwards when its wheels stop moving.  So when our robot somehow got stuck on top of the other robot, it did motions very similar to humping.  That was the highlight of the night.  On the Behalf of my team, I would like to thank the organizers, Teacher Assistants, and all those who have contributed in making 6.270 such a successful and engaging class.  The existence of 6.270 would not have been possible without the help of you guys.