Abstract-Gibson Ek High School has worked hard to bring to competition this year's iteration of Sir Swims-A-Lot. We've focused on software upgrades and standardization of our practices in order to pass down information to newer members.

I. Competition strategy

This year, our team has determined that we will be attempting primarily movement based challenges, as well as some level of navigation intensive activities. We additionally intend to attempt our stretch goals on site at robosub. It's useful to note that our goals are broken into primary goals and stretch goals. We will only put significant resources into stretch goals in the event that we can complete the items that fall into the category of primary goals.

A. Coin Flip

The coin flip challenge is among our primary goals. It is also something that we should already be able to complete with the code we already have, and we have opted to not to attempt the restore and recovery role options.

B. Roll

The smaller size and motor configuration of our BlueROV2 gives us an advantage in rolling, and we have been able to achieve this in past years. Because of this, we are going to attempt this every run, in order to score additional points. Due to our confidence in our ability to complete this part of the challenge, this has also been designated as a primary goal.

C. Slalom

We have determined that the slalom fits the category of primary goal. Due to testing constraints, we have made the determination to have some of the systems that might be useful for completion in place, and ironing out details, and testing at competition. The end result might look like using Sir Swims-A-Lot's camera to detect color, or using the bot's compass to set headings.

D. Gate

The gate is something our team can consistently achieve, and we haven't put additional resources into it this year. We run open loop code to move the robot down and forward for specified amounts of time.

E. Surfacing in the Octagon

As a primary goal, our team intends to surface in the octagon. We plan to achieve this by using the onboard compass to maintain a heading and keep the robot stable enough to guide it precisely enough to surface accurately.

F. Return home

Returning home is a stretch goal--aided by our target of being able to maintain a heading, and remaining stable--we intend to attempt to return home, only if all of our higher priority goals are met.

II. Design strategy

Our robot is a Blue Robotics BlueROV2 Heavy Configuration with a Raspberry Pi 4 running Ubuntu and BlueOS. We have converted the ROV to an AUV using two methods. The first is a python library, bluerobotics_navigator, which interfaces directly with the robot's navigator board. The second is ArduSub MAVLink. This year, we are transitioning from only using the navigator library and have begun to integrate MAVLink into our software design.

A. Connection

We've gone through a few different types of connection - one of our main methods of connection is via a Fathom X tether. We've historically connected through wifi with a router.

B. Compass

One of the big advantages provided by the ability to get data from the robot. With that we have been attempting to design a way to achieve spatial stability with the robot, and prevent drift.

C. Torpedos

Something we have been working on, as preparation for future years, is the foundation for torpedoes. We hope to implement a version of the torpedoes in upcoming years. The current best candidate for a torpedo launcher is a spring loaded design that we have been prototyping via 3D printing.

III. Testing Strategy

Our testing strategy this year centered around getting the robot to move more consistently, as well as discovering new ways to get information from the robot.

A. Hover

Something we have spent a lot of time of time adjusting was the motor speeds and the motors ability to balance themselves. We hope to reach a point where the speed of the motors is no longer a manual input.

B. Compass

With our newfound ability to get information back from the robot, we have spent a lot of time trying to get a solid heading form the compass, so that we can use that for navigation.

IV. Acknowledgements

Thank you to everyone who made this possible. Donors such as The Issaquah Schools foundation, The Gibson Ek PTSA, and Jay Turney gave us the opportunity to be here, and we are eternally grateful for that. Additionally we'd like to thank our coaches and teachers that made it possible for us to succeed and learn from this opportunity. Dan Rosenstein, Angie Bongaarts, Paul Bongaarts, and Victoria Mott.