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Day 1 (9-12-1999) |
Day 4 (10-3-1999) |
Day 7 (10-24-1999) |
Day 10 (11-14-1999) |
Day 13 (11-28-1999) |
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Day 2 (9-19-1999) |
Day 5 (10-10-1999) |
Day 8 (10-31-1999) |
Day 11 (11-21-1999) |
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Day 3 (9-26-1999) |
Day 6 (10-17-1999) |
Day 9 (11-7-1999) |
Day 12 (11-27-1999) |
Day 14 (?) |
Today was our first meeting. We talked about FLL (First Lego League), and Mr. Stanoch told us that the challenge would be coming out on Sept. 25, at midnight. It will be posted at
www.legomindstorms.com. Here is a jobs list:Leader: Brad
Assistant Leader: Adam
Scribe/Webpage creator: Joseph
Programmer: Brian
Designer: Mike
Builder: Todd
Executioner: Steven
Mascot: Robo-Dog
Click
here for a list of problem solving steps.Click
here for a list of leadership skills.Today Adam and Brad brought in a practice challenge called the
Photobot. Its purpose was to locate, and take a picture of a given object. When we were done, we tried it. It worked fairly well, but it broke the first three times. We are starting to understand who should have what job. Last week's list wasn't quite correct. Two people quit, so we will have to work even harder.Top
Today, we started brainstorming about how to build our robot. Here are some design ideas for the claw:
With this design, the ball is allowed in and out of the box by a hole in the top and the bottom, and the claw is controlled with the same motor.
One of our chassis designs was:
This design allows the vehicle to move over rough terrain at a reasonable speed, while still managing sharp turns. The other side of the vehicle would look the same as this one.
Questions:
-Can you bend lego pieces into different shapes?
-Can you launch the Oxygen balls?
Ideas:
-Use a light bulb to direct the RCX back to the base
-Use a differential and an angle sensor to keep the vehicle on track
Today, we spent a lot of the time considering design ideas for the chassis of the vehicle. Here are some of our ideas:
We are also considering using the AcroBot 2 design out of the book, but we are worried that it might flip unexpectedly during the competition.
Today, most people brought in prototype robots similar to the ones we considered
last week. We deided that a robot that could go straight and make very precise & accurate (there is a difference) turns would be necesary. We also discussed how to remove the latch, but we didn't come up with a good solution. While testing tires, we discovered that medium-thickness, small tires were the most accurate, but large, thin tires were the fastest.Today, we had a hard time getting much done. We were slow to get started, and we ended early to watch the Red Sox game. Also, lots of problems occured, like the IR transmitter falling and breaking. However, we did decide the most effective path for the robot to take. It should go at an angle out of the base zone and drop the ball in the ramp which leads to the 20 pts. container. To do this, however, we will need a suspended ball-gripper. We are still considering two ball-gripper designs - the horizontal claws and the box with a removable pole in the bottom. We also considered different ideas for the latch. For example, could we use another RCX to unlatch it? We can't use all LEGO Competition materials anyway, so could we have another RCX programmed so that when the challenge bot sent an infrared signal, the second RCX would open the latch automatically? This sounds like it would be illegal, but if it is fair, it would be a major advantage, saving us near 30 seconds, at least.
This week was a busy one. We did several things. First of all, we built two test robots with ball-droppers. One was so front heavy that it falls forward when it stops, so we have a design problem there, but the other worked well. One idea to help the robot balance would be to make the robot longer and put the RCX as far away from the ball-dropper as possible. If we make the robot much longer, though, it won't be able to fit in the base zone. Also, we considered Brad's ramp idea again. We have some pretty good ideas about how to use it, and we may end up using it instead of the ball-dropper. We also discovered that if we are going to use the rotation sensor, we should learn how it works first, since it doesn't work in an obvious way. We also programmed the working robot to drop a ball in the 20-point slot. It almost worked! We didn't quite have time to perfect the program, though. We also considered using the black lines as guides for the robot. They would be able to tell the robot exactly where it was whenever it wanted to know, but a far more complex program would be necesary. Our homework assignment for this week was to write a paragraph about what happened to the International Space Station to cause the air leak that requires this robot in the first place. Any ideas submitted to Adam can be seen
here. We are making good progress, but we really need to work faster and more efficiently.This week, most of the group members went trick-or-treating, but a few of them stayed behind and developed a latch-opening mechanism. It uses a design where a bar goes past the latch opening when the robot drives by, but it sticks on the way back and pulls the latch out. Other than that, we really didn't do much.
This week, we made good progress. We discovered that our latch-opening device might be illegal, so we may have to revise it. It exerts more of a pushing force than a pulling force, in some people's opinions. We were also told to look up evidence as to what happened to the International Space Station to support our ideas. Some people wondered if an internal explosion could have caused the problem, like on Apollo 13. Maybe the wierd thing seen out the window was remnants of the explosion of an air tank, and the gut-wrenching roar was felt afterward because the explosion was on the other side of the station. Is this a possibility?
This week, we built two versions of the RCX and practiced using them with the challenge course. We discovered that our present design was adequate for the challenge. We also assigned 'homework' for next week. By next week, we hope to have finished everything but the 3rd program and the list of parts used. Just for the record: our team now consists of only 5 members: Brad, Adam, Joseph, Steven, and Mike.
This week, we worked on the program design for the first and second programs. We didn't really get anywhere, but we did decide that we should make the program run when a touch sensor is pushed, instead of waiting 2 seconds or so and repeating.
Since the competition is in less than a week, we had an extra meeting today (Saturday) to try and finish up what we needed to do before the competition. We got a lot done! Joseph and Steve created a poster which shows information about our team, and they wrote up a summary of what we have done (a little like this page), and they wrote up our decision as to what happened to the Space Station. Adam and Mike fine-tuned the latch-opening program and the ball-dropping program, added touch sensor start/stop controls, and created a 3rd program which beeps and waves the crane arm back and forth (this completes the 3rd program requirement, and ends the match with a slight bang). They also came up with some time estimates for the various tasks during the competition:
2 sec - press start button
19 sec left for task 3, which needs from 7.5 seconds up, although it starts getting boring after around 25 - 30 seconds
It looks like we may have a chance in the competition. Our accuracy rate with balls ranges from 15 to 23 (out of 26). For our meeting tomorrow, Mike should catalog the parts used for the vehicle, and make any obvious design changes that would be useful. Brad should have the song program, which we can now use as an addition for the program 3 that we designed today.
This week, we discovered the effects of fresh batteries on the RCX. We replaced the batteries in the RCX, and discovered that new batteries make the RCX go significantly faster. We adjusted the programs to compensate. Also, everyone got a chance to practice. We discovered that our estimates from last week weren't quite conservative enough; we generally only had 5 or 6 seconds left after putting all the balls in. We also made a 'to bring' list of stuff different people should bring. I think we are ready for the competition.
I will start with the bad things that happened so that this entry can end on a happy note. First of all, we were group # 13. Now, we are a scientific group here, but science accounts for everything, and we certainly had a couple of unlucky problems. In the solo trials, our latch mechanism broke. As a result, we only got 10 points for returning to base after attempting to open the latch unsuccessfully, since you must open the latch before doing anything else. In the first head-to-head match, the balls got clogged in the ramp leading into the 2nd oxygen chamber, and as a result we only got 11 out of 20 points (we lost 3 balls due to poor aiming, and we ran out of time for the last 3). In the 2nd head-to-head match, our vehicle kept going at 1/2 speed. Eventually we realized that one motor wasn't working due to a loose wire, which was quickly fixed. Also, a piece from the bottom of the robot fell off. This piece was one of two preventing the bottom half of the robot from falling apart. The other piece did the job for the rest of the match, but the fallen piece kept pushing the robot off course. ALWAYS check for potential loose pieces on your robot before EVERY MATCH is the lesson we learned from that one. In the final match, the balls clogged again. It didn’t quite make sense the first time it happened, so we watched carefully. There were several problems: The competition balls were far squishier than the test balls in the competition set, they were generally very irregularly shaped for foam 'balls', and they were stickier (probably due to their paint job, since both teams got different colored balls) so they clogged more easily. Also, there was a bump in the table just where the ramp ended, since two pieces of whiteboard joined there, and the balls were jamming up there. At the end of the match, we called for a rematch on the basis of defects in the table, but the judge insisted that the lego people who had slid down the ramp as part of task 1 were causing the blockage. They just wouldn't give in, so eventually we just had to settle for…
3rd PLACE!!!!!!!!!!!!!!! WE WON 3rd PLACE!!!!!!!!!!!!!!!!!!!!!!!!!!!
For those of you who are clueless as to what this means, it means that, out of all of the competing teams in New England, we were 3rd from the best! We couldn't have really made 1st, since that team had already been in at least one competition, maybe even two or three. We would have made second had the judges not disagreed about the board problem. So overall, I don't think we couldn't have done much better.
Now for the good stuff: In the solo round, we did keep trying to get the latch open, and we almost succeeded. In the 1st head-to-head round, we put so many balls in that there wasn't any more room for clogging, so we kept 'em comin'. In the 2nd head-to-head round, we did manage to fix the motor. Some teams would have given up (we almost did), but we hung on just long enough. In the final, again we overloaded the ramp and kept the balls going in, and we sent all 26. We only lost 3 due to bad aim. Also, we didn't attack the referee (a little self-control here, people) when he wouldn't consent to a rematch. All in all, I think we did pretty well.
We plan on putting some pictures up, but we haven't even developed our film yet, or even downloaded from the digital camera(s? I dunno who has what). If anyone in this group has any good pictures from the competition, please send them to me.
Day 14
The reason Day 14's date is unknown is because we are still trying to organize it. It will hopefully be an end-of-competition party type occasion.