Toasted Moose DootBuilder: Candice Kamachi
This is the first robot I worked on (with two other people). It was for the 6.270 autonomous robot design contest, and we had three weeks to turn a box of LEGO and electronics into a robot that could collect small nerf balls for that year's contest. Our robot was cool because it was the only robot that could potentially pull balls back out from the recessed scoring bins. "Potentially" because we didn't get the software done. None of us knew Java yet, and it turned out you needed more than the last evening to learn it and write a good program.
I don't remember much else about it, but here is what we wrote for our requisite write-up:
We designed Toasted Moose Doot starting with the ball collecting mechanism. We wanted it to be able to suck balls out of the scoring bin so that we could remove negative balls from our trough or steal positive balls from the opponent's bin. Our general strategy was to collect and deposit all of the positive balls on our side, then to pull out negative balls (if any) from our trough and deliver them to the opponent.
Originally, we planned on having separate mechanisms for removing balls from the trough and collecting them on the playing field. Because the ball collector was over six inches long and the robot could only be a foot long by rule constraints, we decided to put the ball collector on a neck that could move the collector up. This allowed us to build a longer, more stable wheelbase for the robot and still fit within the size limit. (In the above picture, the collector is in the starting, "up" position.) Once the round begins, the ball collector is lowered and the robot is about 16 inches long. Two motors drive the neck through a 360:1 gearbox, which uses a worm gear so that the motors do not have to do work to keep the ball collector in a fixed position.
Once the mechanism for manipulating the ball collector was working well, we realized that we could use it to collect the balls from the troughs as well. To realize this, we had to modify the ball collector so that it could be lowered past the horizontal position and still pick up balls. A potentiometer at the pivot point allows the robot to monitor the ball collector position. By the contest date, the ball collector could reliably pick up and hold eight balls from various angles.
Since we spent most of our time perfecting the ball collector, there was little time left for programming. We threw together a very simple program that relied only on mechanical sensors. This allowed the robot to orient itself and score 20 points if it successfully completed its circuit. However, the limited nature of the program undermined the robot's mechanical reliability, and we did not achieve our goal of pulling balls out of the trough by contest night.
(The name Toasted Moose Doot comes from a section of the Declaration of Independence as detailed by Dave Barry in Dave Barry Slept Here: a Sort of History of the United States.)