Friday, July 05, 2019

The Wharf Rats and the Hail Mary Mods at the Houston 2019 FIRST LEGO League Wold Championship

The Wharf Rats qualified for the FIRST LEGO League World Championship in Houston when they received the Grand Champion award at the North Carolina's FLL  State Championship - Track B.

I want to share a little of the real world engineering experience the team had in Houston. During practice rounds they saw new features (missions) break in new ways under new test conditions and had to respond to the new data. Fix a bug or delete the feature so you can ship the product? Their "ship date" was inflexible. So they learned that sometimes you have to delete features to move a project forward.

Their robot had a rough day during Wednesday's Practice Rounds (scored runs that do not count toward competition scores). Some fixes appeared to work but then they saw new failure modes in missions later in the run. The more they tried to fix it, the worse it seemed to get. The robot was score was just over 100 where it scored 192 at the state championship, and closer to 300 in practice sessions prior to Worlds. They were discouraged and stopped working on the robot before the pits closed at 4:30 pm. Instead they went to the party in the park, listened to the music, played games, danced and just had a good time.

When the party was winding down, I shared that it was a common programming practice to eliminated unstable features from a product to allow you to hit your ship date. So we talked about looking for a key failure point that might have the most impact on their total score. They picked Run 4's Strength Exercise mission whose failure impacted the most missions down the line. They agreed it would be better to eliminate that mission, and it's points, to improve the robot's reliability for missions that follow. But that would require modifying the robot, changing mission fixtures and updating the firmware (thing they worked on for months). Their robot and fixtures are locked up in the pit until 7 am the next morning and their first competition run is at 8:40 am. Time for a Hail Mary! No fear! 

This is engineering! A bug is found in late testing. Your project ships tomorrow at 8:40 am. You can start working on it at 7 am. Now fix it!


Here is the team at 7:33 am Thursday morning. Everyone is tired but ready to go. They are working on their robot with less than an hour before they need to be in the queue for their 8:40 am run. You can see the venue is almost empty (the practice boards do not open until 8 am).

They modified the robot's attachment to remove the mission being deleted, update software and signed up for an 8 am  practice table. They had time for one 10 minute slot to test the mechanical changes and dial-in the programming changes. After multiple corrections, the robot turned the wrong direction then started driving the wrong way, they finally got Run 4 to work ONCE before they had to run to the pit to drop-off the laptop and get in the queue by 8:30 am for their first run! Their 8:40 am run scored 250 which held on to give them 13th place in robot performance! Video linked below.

My favorite part of the run is the 180 degree turn at 1:51. The turn was needed because the robot had been aligning on the wall using the Strength Training fixture on the back of the robot that was deleted. The fixture that was removed left the back of the robot uneven, so the robot had to spin and do the wall alignment using the front of the robot. That also meant that the first mission after the wall alignment, 3D Printer, had to be updated to turn the opposite direction since the robot was now facing the wall rather than backing into the wall for the alignment.

And for a just a little while they they were at the top of the robot games leader board.

They also had a great research project (a system to reduce the deterioration of the human balance system during extended exposure to micro-gravity) that we hope to continue to advance. I could not be more proud of what they accomplished this season!

A great way to support FIRST is by volunteering as a coach, mentor or assistant! Teams can always use extra help with something. Find a team (or teams!) in your area and share your skills! Email me if you want help finding a local team. And contact me if you are interested in establishing an FLL program at your school. 


Coach - Wharf Rats - FLL #5027
Instructor - Summer Robotics Camp

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