Challenging the Vic-Maui in the Pacific Ocean!
by Serena Ramley, Ada 2.0 Team Captain
Here at UBC Sailbot, we have been working extremely hard over the past year to develop our newest robotic sailboat. We hope to share more of our journey with you as we move from the design phase to construction. The Vic-Maui race challenges boats to travel from Vancouver Island, Canada to the Hawaiian Archipelago. Our goal is to design a robotic sailboat that can complete this challenge fully autonomously. We always strive to have our systems follow the best industry practices, designed with quality in mind and tested extensively. In particular, we have been designing systems, construction methods and testing rigs to be reusable, so we think it’s well worth the time now. Your support makes this incredible project possible! We will be presenting at these events (times and locations TBA):
January 17, 19, 20, 21 of 2018:
January 27, 2018:
March 13, 2018:
We would love to come present our progress and passion at your company anytime between February 17 and 23, 2018! You can email Walker Bell, our Outreach Lead, to arrange a visit.
UBC Sailbot Mechanical Updates
Our team members have been using the Larsson and Eliasson Principles of Yacht Design as the primary guide for design. We took inspiration for our new vessel’s shape from the Volvo Open 60 class of sailboats. We examined the hull lines from 12 vessels from this race, and then optimized five of them for maximum stability and minimum hydrodynamic resistance at our scale using Rhinoceros 3D, Orca 3D, Bentley MaxSURF and SolidWorks. After multiple iterations and consideration of other key parameters, we decided on what we believe to be the optimal hull.
We are planning to use a sandwich structure of carbon fibre and high-density foam, partially built with the assistance of CNC-machining to create a reusable mold for future vessels. We need to heat our core material GURIT CoreCell to 110 degrees Celsius to manipulate its shape. In order to reliably fabricate this, we are designing and building a thermoforming oven.
We created a test rig for our rudder actuation system, where each rudder fin has a linear actuator designed for constant usage, high lifetime and low backdrivability in combination with a rapson slide mechanism to translate the motion. After completing our rig design, which uses two sails, we acquired a boat called the Sea Spray 15, whose rig closely matches our theoretical design.
Through careful hydrostatics analysis, we have determined that we can reuse the same keel design as in our previous vessel. We have structurally designed the hull and its cradle (also known as a launch trailer) with strategically placed towing eyes and lifting eyes to give the new boat the flexibility to enter the water either via ramp or crane.
UBC Sailbot Electrical Updates
Our electrical system is planned with modularity and robustness in mind. The batteries are high energy density lithium ion cells from Energus, combined with marine grade Solara panels that can perform well even in shade and a wide range of heel angles. The solar energy is optimized by a Victron maximum power point tracking (MPPT) device.
We’ve kept the hardware that we were very impressed with in our previous vessel, which includes the Victron’s MPPT, the Hemisphere GPS and the LCJ Capteurs Ultrasonic Wind Sensors.
We custom designed a printed circuit board which we call the Universal CAN Controller Module (UCCM) because it powers any device at its preferred voltage and converts all communication protocols into CAN.
Here you can see the overall hardware architecture on Ada 2.0. The Navigation board, the NVIDIA Jetson TX2, makes higher level decisions about routemaking, while the central controller, a BeagleBone Black, processes the sensor information and passes on key information to the Navigation board. BMS stands for Battery Management System, which includes the Solar Panels, a Low-Voltage Disconnect System, and the MPPT.
UBC Sailbot Software Updates
We are developing a network table to manage sensor data, along with an integrated mobile device-enabled web app to facilitate testing and manual commands. We are creating specialized APIs (Application Programming Interfaces) in C++ to send and receive the sensor and actuator signals to use for the overall trajectory planned in routemaking.
While the Mechanical and Electrical teams are normally in the workshop, the Software teams and anyone working on design work meet in a classroom nearby on weekends so that we can stay in close communication.
We hope you enjoyed hearing all these updates! Your kind support has made it possible to achieve this.