After a summer of remote planning and finalizing the design of our boat, we are finally back in Vancouver. Those of you who follow our Instagram account and newsletter may already know that we started construction last week and that we are making great progress.
Stay tuned the next couple of days for a description of our transatlantic vessel design.
Since our initial launch about a month ago, we have been busy testing the prototype. Through a sophisticated testing program, we have characterized relationships between velocity, drag and power consumption. We expect these results to scale well to our final craft.
To find the relationship between power consumption and speed, we measured the current drawn by the motor with a current sensor. Timing the boat over an interval of known length, we were able to relate the current to the speed of the boat.
Additionally, we need to know how drag force relates to velocity when designing our Trans-Atlantic vessel. To find this relationship, we used a block and tackle setup with calibrated weights to exert various constant known forces on the boat. By measuring the terminal velocity, we determined the generalized drag curve for the hull.
From theory, we expect both current draw and drag force to be proportional to velocity squared. As seen in the graph above, this behaviour was seen from the experimental data.
Looking forward, we will use these findings to decide on the parameters for our final craft concept. Stay tuned for updates on this design concept later this week!
There was no doubt that the crew was excited after today’s successful prototype launch. This morning, a group of 6 team members went to the Royal Vancouver Yacht Club to check how the boat sat in the water. Although she is not autonomous yet, we drove her around with a remote control to do some initial speed testing. At 4 knots, we were surprised at how fast she cruised through the water.
This week we will be accelerating our development of a basic autonomous navigation system, and hopefully have something autonomous ready by next weekend. Needless to say, we are very excited about our progress and what is to come next.
Since the beginning of March, the team has worked intensively on getting the prototype ready for on-water testing. Last night, the final touches were made, and tomorrow we will put her on water for the first time. We are very excited to see how she sits in the sea, and to do some initial testing!
Stay tuned for updates over the weekend.
Here are some pictures from the yesterday’s session:
After three months of research, planning and drawing, our hull design team started constructing the prototype of our autonomous vessel out of cedar wood and fiberglass. The prototype has a streamlined design, to reduce friction and increase efficiency. Using wood helps decrease the overall weight of the vessel. The prototype will show us how our proposed vessel design behaves in real world conditions, and it will enable us to optimize it further.