Legos in Paradise - Climate Connections Season

Our Research

The 2008 theme is Climate Connections. We had to research how climate affects our community. We had to find a climate-caused problem in our community, find out how our community is helping solve the problem, then create an innovative solution, and share what we learned. We talked to Craig James (Retired Meteorologist from WOOD TV 8), The Grand Rapids National Weather Service Climatologist, Warning Coordination Meteorologist, and Hydrologist. We found out that we live in a Humid Continental Climate. We later talked to Mr. Haagsma from the Kent County Road Commission. Then we decided to narrow our problem down to potholes.

Legos In Paradise at the National Weather Service (Click to Enlarge)

Legos In Paradise at the Kent County Road Commission (Click to Enlarge)

The formation of a pothole: When vehicles drive over the road, they bend the road slightly forming small cracks first on the bottom and then on the top. Water then gets in the cracks and freezes and thaws increasing the size of the cracks, eventually making an empty space under the road that fills with water then freezes and pushes up the road. Then after the ice melts it leaves an air pocket, a vehicle drives over, the asphalt is crushed creating a pothole.

We wanted to figure out when every pothole got fixed. But we figured out that no one tracks that information. So we figured out what days had the right condition for a pothole. Low tempuratures below 33oF and high tempuratures above 31oF and precipitation is a good condition for a pothole. We also contacted people from websites that have a pothole report button like the mayor of Grand Rapids. One responded and said that they don't track that information. Then, 2 weeks before the Grandville Tournament, someone responds with pothole complaints all the way back to 2003! So, we added that information to our charts at the last minute.

   Some solutions are: In Kent County, Michigan they typically use Hot-patch in the winter if they have hot-boxes (a burner underneath a large metal box used for keeping the Hot-patch hot) available, otherwise they use Cold-patch. They tried adding rubber pellets to the mix of the asphalt and that didn't work. In Grand Rapids, Monroe Ave. to Division Ave. in Monroe Center is heated by a Snow-Melt System to keep the precipitation from freezing.

   We had to think of an innovative solution of our own. Our solution is called Tuf-Foam. Tuf-Foam is made from recycled plastic placed between the asphalt and the sub-base. The top layer is dense and can withstand the pressure of heavy traffic. It has small holes to let the water through. The bottom layer is a plastic foam with large holes to allow the water to flow through it, yet if the water freezes before it drains from this layer, the Tuf-Foam has the properties to let the ice compress both layers instead of pushing up the pavement.

   To find another community that is having the same issue, we contacted Team #3837 NX-Treme from Ashburn, Virginia and exchanged information. They have the same climate as we do. Researchers in Virginia are working to develop a better, more durable, pavement. We found out that they also use Slurry Seal.

Our Robot

   We called our robot Walley the Shark because last year we called it Shark II and some of us wanted Walley and others Shark III. Walley the Shark uses 3 motors (2 for driving and 1 for attachments), 1 touch sensor, and 1 light sensor. Walley the Shark mostly uses differential steering but uses one-wheel and reverse direction steering. We use the NXT because it automatically adjusts itself since the motors have built-in rotation sensors. We use Mindstorms NXT 1.0 for programming.

Legos In Paradise Robot Grabbing CO2 Balls (Click to Enlarge)

Last year we ran into problems about downloading several programs because the NXT doesn't sort them alphabetically. So we made one program called the Mission Organizer that runs MyBlocks which are the mission programs.

The puzzling File Errors
We started to make more and more missions and importing them into the Mission Organizer, then we ran into problems running the Mission Organizer on the robot. It will always say "File Error!" on the screen. If we drag some MyBlocks out, it will work fine again. We don't use arrays so it's not because of out-of-bounds array accessing. We knew that it wasn't the MyBlocks themselves but something within them. We found that the Wait for Light Sensor blocks were causing the problem. We tried switching those out for a Loop Until Logic with a Light Sensor Block inside, but still no luck. We figured out we can only have 11 Wait For Light Sensor Blocks until it comes up with a File Error on our NXT. Actually, now we know that it's any Wait Blocks (except for Wait for Time) that's causing the problem. So, that would be 15 Wait Blocks. Then we contacted Mr. Abernethy of the Bots on the Rock robotics club and he said that the robot has to store data to a cache (temporary memory) when it has to use sensors. We used too many sensor blocks (not sensors physically) in one program and it filled up the cache of the robot. But you can have several programs because the cache empties itself after a program stops.