Thursday, 4 July 2019

In depth with the UVSRC



Actuonix Motion Devices is a proud sponsor of the University of Victoria Submarine Racing Club, a design team based out of our home territory of Victoria, British Columbia. Ahead of their international competition in Washington, D.C., Team leader Liam Scott-Moncrieff was kind enough to provide some insight into the program and the team’s season so far.

Can you tell us a little bit about the program and the history of the club at UVic?

The UVic Submarine Racing Club (UVSRC) is an undergraduate engineering design team at the University of Victoria. UVSRC is UVic's youngest design team, having made their debut at the European International Submarine Races (eISR) 2018 in Portsmouth, UK, with their submarine 'Chinook'. eISR 2018 was a huge success, with Chinook taking fourth place out of 18 teams.

The club is composed of a team of 15 core members and 20+ contributing members, including students from mechanical and electrical engineering, computer sciences, business and even history. The team is split into 6 sub-systems dedicated to one aspect or design feature. The students get to apply the knowledge gained in class to designing and manufacturing a real-life project. The project is funded through grants, donations and sponsorship from within the university and external businesses.



What’s new for this year?

This year, UVSRC is competing at the 19th International Submarine Races at the Naval Surface Warfare Center in Washington D.C. with 'Chinook II', a new and improved version of last year's hull.

Chinook II, like Chinook I, is a flooded, human-powered submersible vehicle. It measures 11'9" long and is 2'2" at its largest diameter. The pilot floats prone in the vehicle and pedals to turn a pair of couter-rotating propellers. The submarine is controlled by a pair of rudders and dive planes at the stern. These are controlled by the pilot through a cable linkage to a steering column at the bow. Chinook II has integrated SCUBA tank and regulator for the pilot, as well as a secondary safety tank and emergency pop-up buoy. While last year's fibre-glass hull was retained, several significant improvements have been made to make Chinook II faster and more nibble in the water.

Firstly, the steering system was completely overhauled. Where previously there was an assembly of cut and drilled bar stock there is now a precision-machined alignment frame from our sponsor Rainhouse Canada. The frame holds the shaft bearings in alignment with the hull and, with the help of two u-bar connector joints, allows the rudder and dive-plane pairs to move together in perfect alignment.

This new steering system is complemented by brand new control surfaces. These control surfaces are thinner yet stronger than last year's, thanks to their caste-resin over waterjet frame construction. They use biomimicry, taking inspiration from the blue whale, whos' fins' have bumps and dips along their leading edge, called 'tubercles'. These tubercles have been shown to reduce the stall angle and increase lift at low speeds while keeping drag low. Initial testing has demonstrated excellent performance and we are hopeful these will give us an extra edge at the competition.

Last year's propeller blades have also been swapped out for larger and stronger blades. The new blades are constructed from a 3D printed plastic core, allow for an ideal, high efficiency shape. Internal blind holes the length of the blade allow two steel struts to be embedded inside, giving them excellent bending and shear strength. This is further complimented by a carbon fiber skin, making the blades rigid and durable. These blades have greatly increased the power the pilot can transmit to the water, allow us to accelerate faster and reach higher speeds.


Finally, troubles maintaining a consistent depth at last year's competition has lead to the introduction of an electronic depth controller. This controller will automatically regulate the submarine's depth, allowing the pilot to concentrate on pedalling hard and steering straight. The controller works by reading the water pressure using a high-accuracy piezo-resistive pressure transducer. This pressure value is compared to the desired depth and run through a control algorithm, which sets the dive plane angle to keep sub at its ideal hydrodynamic depth.

How are you utilizing Actuonix micro linear actuators in the project?

The actuation is done using a linear actuator and accompanying control board kindly provided by Actuonix Motion Devices. The device was chosen for it's high strength and ability to be easily and reliably waterproofed over a rotary servo. The actuator is mounted in a watertight enclosure and actuates a precision-ground steel shaft. This shaft passes through a double o-ring barrier out into the wet exterior, where it connects to a lever-arm linkage that drives the dive plane shaft. This is favourable to a servo motor as it does not require additional gearing and does not experience bending forces from the control surfaces that could compromise the o-ring seals.

What are your goals for this season’s competition?

We are hopeful that these key improvements will allow us to perform better and go faster than last year, and with luck and some fast pedalling, make the podium at ISR 19. This would be a huge accomplishment for us at the more competitive American event. Making the podium in just our second year of operation would be an excellent testament to the hard work and talent of UVic engineering students, and would give us the energy and inspiration to continue innovating, improving and learning.



A big thanks to Liam and the UVSRC team for taking the time to get us up to speed with their project. We’ll have an update incoming with the results from Washington!

For more information on the UVSRC team visit https://www.uvicsubmarine.com/