This website is dedicated to the robot designed and built by Alex Crumlin and Rohit Gupta (design help from Ethan Crumlin). This robot is for the 6.270 autonomous robotics competition. 6.270 is a month long blitz of legos, code, and sensors with the goal of beating your peers in head to head competition! This is the story of... Cookie Monster!
So our strategy went through a gauntlet of test, trials, and tribulations.... We started with a very agressive strategy to run up the hill, grab all four balls, and then sort them on our way down to the lava pit, and score! However, this was soon to prove a little more difficult than we were expecting. We then decided to try just for one ball, and see how that goes. After several experiments (including an elevator system, claws, and a slide) we decided that we would make a big paddle that will go around and move balls into our robot.
So our strategy was such: go up the hill grab the first ball w/ the paddle and determine what color it was. If it was our color we would then hold onto it and then go to the one point scoring zone and stop. Originally we were planning to go to the cup and score... but that we changed it to the simpler score one point strategy. If the ball we picked wasn't our color, we would ditch it out of the back and then score search for another ball.
This is one of the reasons we named the robot cookie monster... It was made of almost entirely all blue legos (and the way it grabbed balls gave it a gobbling type appearance, along w/ the fact that the night before it was due, we pulled an all nighter with only chocolate chip cookies to eat!). This robot was an electrical wonder! It had 12 light sensors, 9 for line following, 2 for paddle location detection, and 1 for ball color differentiation. Cookie Monster had 3 "feet", two in the front and one in the back. These feet had the light sensors to follow the lines. The idea is that you would use one of the front feet when traveling up to grab a ball, and then turn until the back (in the middle) "foot" was now able to track a line, and then follow that line down to the cup. In theory it worked beautifully! There were also touch sensors to detect if a ball hit the paddle, and if a ball was in position to be filtered (figure out what color it was).
Mechanically, the robot used three motors. Two of them for driving the two wheels in the back (with a gear ratio of 135:1) each, and another motor to opperate the paddle w/ the same gear ratio. There was also a servo used in the back of the robot to open a hatch to release bad balls. The back (the power train) of the robot was connected to the paddle and the feet by a system of trusses, which served as great structural support. We also did something interesting that no other team did! We used our legoman as a functional part of our robot. We used the legoman to reflect white so that we could stop the paddle in the positions that we wanted them to be stoped at. Below is a pic or Cookie Monster!
The results were mixed. We did qualify, that means cookie monster was able to score a point (and boy did he look good doing it!). This allowed us to go to the finals where we faced another impressive robot. However, the finals were not so kind. We had a great start. The robot turned, found the line, and the paddle went to it's position. The robot then started to climb the hill, and then stopped... It started to move very slowly to the first ball. Rohit and I crossed our fingers, until it finally stopped... We then lost hope... Then it started moving forward again, very slowly, but it was getting close to the ball! Then it stopped again... At this point we were just hoping it would move the 2 inches it needed to... but alas it did not. At the end of the round neither team scored, and we were both eliminated. Cookie Monster's run had ended. It was a great experience and we did qualify, which is good enough!