Team 53 - Paul, Kristina and Catarina

Catarina Kristina & Paul

Team Strategy

Our path for starting on the north Our path for starting on the south Our team's strategy is to win! Just kidding. Our team's strategy was to first orient ourselves and push the 4 balls next to our scoring area into our scoring area, giving us at least 2 points we would then proceed to the red side of the field, open our gates, gather in the balls next to us and near the voting area and get up a high vote for red. After this, we would continue in the same direction around the field and attempt to push the last group of red balls into our scoring area (relying only on luck, mainly). We would then attempt to collect the green balls on the other side of the field and sit in our opponenet's scoring area with them to lower his score. We assume the red vote is winning, which could be bad for us if that's wrong.

Pictures of our first robot :)

from above side view
More pictures

Our first robot had a gear ratio of 45:1 and as you can see was rather simple.
It was made primarily to complete a few assignments. Our final robot is
similar to this one, but much bigger, and a lot stronger.
(We even won an award for having such a strong structure: Most likely to survive the drop test)

Robot's right side After some painful nights spent trying to get our test robot to seek out a target using coordinates, we had to get to work on building a beta for the competition. We kept the basic platform we had for the Handyboard from the test robot and set to work building better sides. Here's an early picture of a side of our robot. Most of the side was only 2 FLUs wide, but what's not too visible in this picture near the top is a section about 4 FLUs wide to connect to the main platform. The axles for the back wheels also fit into the sides. The robot uses a differential drive system for movement, with 2 wheels in the front for support (They don't steer at all). One interesting thing we did do with the front wheels, however, was use plastic white wheels with foam tape around them (sticky side out and still covered, of course). This was a slight help to us with turns, although, as was seen in the contest, we ran into other issues with turning later on.

Now, on to some mechanics of our robot. Initially, our contest robot, or at least the beta, had a gear ratio of 25:1 with 1 motor for
each of the driving wheels (Ok, ok, get all your laughs out now). Moving forward and backward like this was difficult enough, even with the
motors running at full speed (we wanted the robot to be really fast to implement our strategy). When it came to the turns, though... yeah...
well, enough about that. After being laughed at by a few caring organizers and TAs, we set out to rebuild the gearbox. Luckily, we were
to rearrange a few axle positions and change our gear ratio to 75:1. Though our 'helpers' thought this would help, turns were still nearly
impossible with our robot's immense structure. Nearly the week of the competition we added another motor to each side, and, needless to
say, we were driving much faster and actually turning! This was also around the time we got a working gyro to help us with turns. Most
people don't seem to think the gyros aregood for turning, but I guess with our immense structure and already slow turning abilities, we
were in a good position to use the gyro accurately.

First 'servobox' used to open the front gates

This picture is the first "box" we made to house the servo used to open the front gates.
We had to change it later on because of size considerations. The box was connected to
one of the front sides of the robot, and, like most everything else in our robot, was
well-braced to hold it down should collisions occur.

Final robot (almost) showing the 'servobox' The gate in the front isn't designed as best as it could be. With all the gears going across the top, the gates could become quite out of sync, but not enough to cause any major trouble. Originally, this was designed to have Beta robot with bigger gears across the top bigger gears across the top as seen in the picture on the left, but this was also changed due to size considerations (our robot was very big). We were going to use the platform across the top as seen on the left, but it didn't quite work out. The black plates seemed to be difficult to get to stick, although once stuck they stayed in place very well.

Our code was relatively simple as we hoped to keep our strategy simple as well. We used most of the gyro code provided by
Analog Devices, with a few modifications, such as a backward function. We also modified the way turns were done as we
could have relatively high accuracy even with high motor speed. We had IR Led/Phototransistor pairs on the bottom of
the robot to get our initial orientation, and we tried to use those to identify points where we should stop also, but
the latter didn't quite pan out. The reason for this is quite possibly that our speed was too high and the sensors
could not find the black lines. There's not really much else special about our code.

As for our results in the final competition, they were somewhat disappointing, although we did at least score positively
for ourselves. As mentioned earlier there were a few problems with the additional motors. My personal thoughts on this
are that our turns became obstructed by the raised parts of the board in the scoring areas. In order to ensure that the
motors stayed in place, I added an extra beam to the bottom stretching across the bottom of the motor box and braced it
to the side of the robot on each side. I would say this most likely made it so much more difficult to turn, although in
lab, this never seemed to cause any trouble.

However, 6.270 is awesome!

updated 050129

The team was 66% female... I didn't choose the font, I just wrote with it.