I would like to introduce the “Mike”; a project I’m working on for the last 3 years, which was initially based on the SolarSurfer .
My goal was from the beginning, to design a solar powered USV, remotely controlled by satellite, with the possibility to steer near shore in undeep waters, making photos and movies on demand. But also the ability to travel long distances, preferably crossing an ocean.
Best thing about steering with 2 thrusters is the lack of a rudder. A constantly moving rudder is a weak point in long sailing DIY USV designs, just as Seacharger’s final days made clear. It will wear out, start leaking, or the multiple moving interactive parts will give way sooner or later.
Second important design feature, is a minimum “plastic bag” and seaweed catching vertical underwater surface. Not only to minimize the chance on a trip-ending collision, but as well to reduce drag.
This made me change the steering/propelling by 2 central placed thrusters, to a T200 at the back for propelling, and a T100 bow thruster for steering.
A self righting weighed deep keel was no option, preventing sailing near the coast for taking cool pictures over there, and because it’s also a drag increasing plastic bag catcher.
Hence the need for a righting system on board, in case the boat is turned upside down.
The system I came up with works fine in theory, as per finite elements floating simulations, but still need to be proven in reality. Only moving parts of that system are a low cost air pump, and some coffee machine solenoid valves.
Sailing towards the coast could be save enough, if depth can be monitored by sonar.
I can’t find any affordable depth/fish finder who can be connected to a Raspberry Pi, to be useful. My solution is to use a cheap hand hold fish finder, put it in glued-Lego made jig with a lens, LED and Raspberry Pi camera pointing at its display, and analyzing the readout to get the depths in Python were I need it. The fish finder is turned on by a small servo, pushing the on/off-button.
This system I have tested in a swimming pool and works fine, but I really would like an alternative…
To prevent the possibility of leakage, which most likely results in death-of-vehicle, I ended up with a concept of glued together fiberglass top and bottom parts, which are after assembly with all inner parts, foamed full with closed cell marine foam.
There will be a front and back part with each a 120W solar panel on top, which can be screwed together on a launching beach, so there is no need to transport the whole boat long (10.8 foot)and heavy (120+ kg) in one piece.
Some potting of electric and electronic connections will have to be done on the beach as well, because water tight connectors are too big, or not reliable if not of industrial price.
The solar energy will be stored in 6 sets of each 4 15Ah LiFePO4 batteries. 1 of these sets is only to be used for the electronics, and so 5 sets left for propelling and steering.
Dedicated Arduinos will monitor voltage of each battery during charging and unloading, and do the needed sets-switchings by relays. The goal is to sail 24h/day, and in theory and by simulations, a speed of up to 1.5 m/s should be full time possible. Steering should take about 4% of energy available.
The whole boat will be controlled by 1 Raspberry Pi, and 4 Arduinos. The Pi should steer against found current, so that a straight course between 2 waypoints is possible. This works fine by simulation. I spend a lot of time making simulation software, because “testing” in real live is way too much work and complicated. It just will have to work.
By Rockblock, the plan is to get every day 8 positions, which will be made into kml files for Google Earth, for all who are interested, to follow. Lots of other information from the boat and its findings and workings will be sent by satellite messages as well, mostly made part of the kml update.
Currently, the positives for the 4 fiber glass parts are being made, so I hope to start assembling from next month. Metal parts are finished, and most of the electrical and electronic parts are in house, and are being tested with a whole lot of software.
I do this all in Vietnam, where I work as an engineering production sourcing consultant. That is great for keeping manufacturing of the metal (including the wire mesh stainless steel welded deflector for T200) and fiberglass parts low cost, but not easy to get your hands on stuff like the needed marine foam resins, and other chemicals to glue and seal the solar panels. I still need a way to ship these from the US to here (must come by sea).
I have not much time to keep a building blog for this project, but I will here give now and then updates, and hope to launch from a Vietnamese beach begin 2019. I will give link to the daily kml files for tracking, and will inform about actions and hopefully progress. The aim is to sail north of the Philippines to the Pacific, and from there to California, making photos and movies during storms (tilt-meter triggered) and during “raids” to island beaches.
All photos and videos will be stored on a USB stick (in a sealed screw-cap bottle), for somebody to collect and upload, so I can add links in the final kml file to them.
But that is still all far away…