Lucas Murphy

Mentor: Dr. Shannon Ridgeway
College of Engineering
"During my time at the UF Machine Intelligence Lab, I've become involved with various autonomous robotics projects. One of these projects is PropaGator, a student designed/manufactured autonomous boat that competes in the annual RoboBoat competition hosted by the AUVSI Foundation and the Office of Naval Research. PropaGator's propulsion system currently consists of two belt driven hubless propellers that are capable of azimuth steering. While they provide significant thrust with minimal drag, they are prone to mechanical failures due to their complexity. I decided to research and implement a new version of these thrusters that use integrated brushless motors to drive the hubless propellers. The goal is to develop thrusters that will maintain the benefits of the hubless propellers while increasing reliability, serviceability, and efficiency. In addition to enhancing robotics projects in the Machine Intelligence Lab, this research will also benefit the maritime industry by providing useful information on marine propulsion."


Mechanical Engineering



Research Interests

  • Marine Propulsion
  • Robotics
  • Mechanical Systems

Academic Awards

  • Florida Academic Scholars scholarship (2012)
  • UF University Scholars Program scholarship (2015)


  • UF Machine Intelligence Lab


  • Construction project for community park in Bainbridge, Ohio

Hobbies and Interests

  • Camping/hiking
  • Machining/welding
  • Traveling/sightseeing
  • Competitive marksmanship

Research Description

Integrated Brushless Motors for the Thrusters of an ASV
Background --- PropaGator ( is an ongoing autonomous surface vehicle (ASV) project within the Machine Intelligence Lab (MIL, at UF. The second generation vehicle is outfitted with a student designed and manufactured hubless propeller thruster system with azimuth control. While these thrusters has proven to be effective, there are inherent reliability issues with the design. A brushless motor transmits power to the propeller through a drive belt, while the entire assembly is rotated by a belt driven servo. The complexity of this drive system makes for time consuming disassembly. This poses a major problem during competitions when mechanical failures or worn out components need to be quickly taken care of. Proposal --- The objective of this research project is to redesign the current thrusters, addressing the primary design flaws. The goal is to design and manufacture an inrunner brushless motor that will be integrated around the propeller. The coils will be housed in the propeller shroud and permanent magnets will be embedded around the outside of the propeller, effectively making it the rotor of the motor. This will eliminate the complex belt driven system, simplifying the disassembly process and increasing the thruster’s inherent reliability. Also, the motor will now be submerged, allowing it to be cooled by the surrounding water and reducing the generation of heat inside the hull of the boat.