UW Human Powered Submarine "The Underdawg"

Designing electrical system for UW's human-powered submarine

Designed the electrical system aboard UW's 2020 human-powered submarine (The Underdawg) - pilot controls, power distribution, data logging, a variable-pitch propeller, and a custom battery pack - wrote all onboard firmware, and led the CAD effort. The team placed 1st internationally in the design report competition.

1st internationally - Design Report competition

Role

Electronics Systems Lead · CAD Lead

Applied

PCB DesignC++SolidWorksEmbedded SystemsData LoggingPower Distribution

Reference

Design report ↗

The Underdawg - UW Human Powered Submarine full vehicle render, white and purple livery with three-blade propeller — FIG 01The Underdawg - UW's 2019-2020 submarine featuring a composite hull, electrically actuated control surfaces, and variable-pitch propeller system.

My contribution

Designed all electrical systems - pilot control, power distribution, data logging, a variable-pitch propeller, and a custom battery pack.
Designed custom PCBs (Control Board Rev 4) and ran the supporting circuit calculations.
Wrote all embedded firmware for the two onboard microcontrollers.
Led the electronics team through design and integration.
Owned CAD as overall lead - built the master SolidWorks assembly and produced all renders and promotional materials.

The Underdawg - second render angle — FIG 02Wireframe rendering of The Underdawg displaying drive train and control system.

Objective

The Underdawg was UW's 2020 entry in international Submarine Races (ISR)- a fully enclosed, pilot-driven submarine raced against teams from around the world. The electrical system has to keep a single pilot in control of propulsion and steering, capture performance data for analysis/validation, and run reliably underwater on a self-contained battery pack. I owned that electrical scope end-to-end and served as the team's CAD lead.

CAD rendering of control ring in its electrical control configuration. — FIG 03Control ring CAD render - the control ring and drive system setup in its electrical control configuration.

Control Board Rev 4 front - custom PCB designed by Nikolas Johnson, blue substrate with gold pads — FIG 04Control Board - front. Custom PCB designed by Nikolas Johnson.

Control Board Rev 4 back - navigation, data logging, and power circuitry — FIG 05Control Board - back, showing the navigation and data-logging subsystems.

Technical details

Two onboard microcontrollers run the submarine: one handles the pilot control system and propeller, the other manages power distribution and data logging. The control board carries the control electronics, sized from circuit calculations done during design. A custom battery pack supplies the system and the onboard logging captures the performance data used to support the design report.

UW HPS electrical configuration - complete wiring diagram and system layout — FIG 06Isolated rendering of electrical control configuration