Thursday, October 28, 2010
Strategy & Machine Concept with screenshots/photos
STRATEGY
General
Our strategy focuses on scoring on the tabletop with strong emphasis on defensive play. There are several reasons for this:
1. There are more than twice as many points available on the tabletop as in the slot
2. There are more high-value balls on the tabletop, leading to more efficient scoring
3. Tabletop strategies lead to simpler robot designs (slot-focus will require complex or multiple arms, which can be very difficult)
4. The rules are very lenient on defensive play
5. Tabletop robots can play defense on both slot robots and other tabletop robots
6. Tabletop robots will be more versatile, allowing us to adjust our strategy for each match
Disadvantages to this strategy include:
1. Vulnerability to plugging up funnel
2. Relies more heavily on driver skill
3. Risk of falling off table
4. Higher risk of incurring penalties
5. Need to use several motors for driving
The advantages in this case outweigh the disadvantages more heavily than any other strategy we analyzed.
Specific
From this general outline, we intend to play a typical match as follows:
1. Drive to offensive end of table
2. Corral two sand-filled squash balls behind scoring funnel in one effort
3. Score both balls in funnel
4. Immediately turn focus to defense, unless it is clear that we are not winning
5. Play shut-down defense for rest of match, unless the other team pulls ahead
We feel that we can complete the scoring maneuver quickly enough to reliably put us ahead at that point in the match. For a slot-focus robot to equal that score, they would have to have scored every single ping-pong ball and two squash balls! We also feel that slot robots, contrary to circulating belief, will be extremely vulnerable to defense from a tabletop robot.
Comparison with other strategies is illustrated in our strategies Pugh chart.
CONCEPT
To execute our strategy, our robot will need the following attributes:
1. A well constructed drive that, ideally, has low and high gear capabilities
We will absolutely need a low-speed, high force gear in order to play effective defense against slot-focus bots (which we anticipate to be a majority). With this, we will be able to push the base of the robot around and really torque on their arms operating below. This will also help against tabletop robots, as we can camp out over our own funnel, and if we are a stronger pusher than they are, they won’t be able to score.
A high gear, although not as essential as a low gear, will help us score more quickly and play defense against other quick tabletop robots.
2. A method of easily collecting and releasing two sand-filled squash balls at once
This mechanism must work quickly and reliably or our strategy basically goes out the window. We aren’t going to have time to mess around with lower value balls if we want to play heavy defense, and the only way to get the sand-filled balls is to front-load or corral them. We identified many potential modules for accomplishing this, and are currently working with scoop-like mechanism that swings down and controls the balls.
3. A versatile defensive feature
The operative word here is versatile. We want to be able to defend against every opposing strategy. To that end, we are developing two potential solutions that would both be used. First is quite simply a strong pushing plate, which will be anchored to the back of our robot (we will drive ‘backwards’ when playing defense). This will allow us to harass both tabletop and slot robots with a high-force drive.
The second is a metal sphere that will be contained by a cavity underneath our robot. It will roll around on the tabletop under our chassis until we drive over the slot or our own funnel, at which point the sphere will drop. It will be large enough to plug the funnel. If dropped in the slot, it will get in the way and gum up scoring operations.
This concept was created out of a combination of the best ideas presented when completing our concepts Pugh chart.
Screenshots (SolidWorks):
Photos (Physical Model):
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