Ladon Project

A robot to sail around the world alone

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We're building an autonomous sailboat to sail all the way around the world by itself. We currently have two boats -- a modified kayak that we've used for systems testing, and a smaller sailing model we're using to develop our sail propulsion.

Our sailing rig is a unique configuration we call a wing schooner. It uses a pair of self-tending wing sails to eliminate the need for a rudder or any other moving parts below the waterline, which mean that we're naturally more durable than other ocean-going robots.

Once we've sailed around the world, we plan to make our robots available to researchers and others who need eyes on the water.


Please help support Project Ladon on Patreon!

We're building an autonomous robot sail boat to circumnavigate the world. We have two boats -- a modified 18' two person kayak with solar-electric propulsion we call TSV Disputed Right of Way and a small sail demonstrator that doesn't really have a name yet. 

Our current work is focused on refining our sail propulsion system and raising money to build the round the world boat. After we build that boat and send it on its way, we plan to offer our boats to researchers, fishery managers, and others who can use them to observe, protect, and preserve our oceans. 

TSV Disputed Right of Way 

This is the boat that let us get our feet wet. It's propelled by a small trolling motor powered by solar panels and a pair of truck batteries. It uses a single Beaglebone Black for brains, with an Adafruit 9-DoF IMU and Ultimate GPS for sensors. In the current version, it uses a MiFi for ship to shore communication and for a control panel. It's taught us a lot about operating an autonomous boat on the water, but we've laid it up for now to concentrate on sail development. 

Sail Demonstrator

We've developed a unique wing-sail rig we call a wing schooner for our sail demonstrator. It consists of a pair of self-tending wing-sails that can be controlled independently. Since they can be controlled independently, we can trim them to produce a turning force. That eliminates the need for a rudder, which means that we don't need to have any moving parts underwater. 

A self-tending wing sail is not like the wing sails on America's Cup boats or the Vesta Sail Rocket. It's free to rotate around a vertical pivot and the direction it points relative to the wind is controlled by a small tail. This means that instead of the relatively large forces required to control an America's Cup wing sail, it only requires moving a small tail. The actuator for the tail is also far from the water. 


There are four main blocks to the sail demonstrator electronics:

  • Main brain
  • Ship to Shore
  • Fore Sail 
  • Mizzen (Aft) Sail

The main brain is a Beaglebone Blue with an attached GPS, AIS receiver, R/C receiver, and battery. The Beaglebone Blue has, among other things, an onboard 9-DoF IMU and a battery charger. This drastically reduces the amount of support circuitry required and lets us pack everything into a Pelican 1040 mini case. This is still a work in progress, although most of what remains to be done with it is software.

Our ship to shore radio right now is a MiFi. Besides providing us coverage all over the Puget Sound, it also provides the access point for the onboard WiFi network. Using WiFi means that we don't need to have rotating electrical connectors for the sails. It also gives us a direct upgrade path for going offshore, because Iridium (among others) offer satellite transceivers that also can function as access points.

The foresail and the mizzen are identical with the exception of a program pin that determines whether or not the particular sail is fore or mizzen. They're built around the Arduino MKR1000, which provides both WiFi and a battery charger. There are also two sensors -- a Sparkfun 9-DoF stick and an angle of attack sensor. The 9-DoF allows the software to determine the angle between the boat and each sail by comparing compass headings. The angle of attack sensor tells the software which way the wind is blowing relative to the wing sail. 

Unfortunately, there are no good, cheap, small electronic wind vanes on the market. We use a 3d printed vane with a magnet in it and a 3 axis magnetometer to sense the angle between the vane and the carrier. This gives us a direct read-out of angle between the vane and the wing, and therefore the angle of attack. 

While we're developing the software to sail the boat, we've built a small manual controller out of another Arduino MKR1000 and a couple of pots. This provides straightforward (well, sort of) manual...

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Project Ladon MFBA 2017.pdf

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  • A very late update

    Pierce Nichols08/29/2018 at 06:32 0 comments

    A few updates...

    • We're going to try for the Microtransat Challenge as a stepping stone to going all the way around.
    • We've been sailing a few times since our last update. Our current wings are a bit on the heavy side, and their centers of gravity are high. This drastically limits the sort of wind we can sail in, which really cuts into our testing opportunities, and slows us down.
    • We've made huge progress on software -- check out our Github for details.
    • I've done some talks about the boat, including at MakerFaire Bay Area 2018 and Toorcamp 2018. Check out the slides at our blog. I'm trying to find video of the Toorcamp talk, but no luck yet. 
    • Over the past few months, we made a set of molds for the wings for the Microtransat boat. I'm a little dissatisfied with them and I'm having a hell of a time making the pivots we designed, so they may turn out to be a failed experiment. We shall see.

  • Under Sail

    Pierce Nichols10/02/2017 at 03:19 0 comments

    Due to some last minute wind, we were able to get the boat in the water today and do some quick sailing tests. 

    We did get the boat moving under sail power. However, doing so in a predictable and readily controllable manner is going to take some more work. The tether you can see in the above picture turned out to be invaluable.

    The most obvious problem is that the tails are not big enough to reliably control the inertia of the sails in relatively light and variable winds, like we had today. There are two approaches to this problem -- lighten the wings and make the tails bigger. These sails are the weight they are and that's not going to change until we build the next sails (already in process). We can always print some larger tails, and plan to do that ASAP. 

  • Updating updating

    Pierce Nichols09/08/2017 at 15:34 0 comments

    The detailed description is woefully out of date, so I am updating it in stages. Then I'll write a nice long log about all the fun we've had with sails. If you don't want to wait for all that, come to Seattle Mini Maker Faire next weekend (Sept 16-17) and ask us in person! You will also have the opportunity to sail our demonstrator boat while it's safely attached to a turntable. 

  • Dead motor, dead batteries, on to sails!

    Pierce Nichols07/31/2017 at 20:40 1 comment

    Analyzing the data from our last test and some motor experimentation has made it clear to me that both our batteries and our motor are toast.

    First, the batteries are nine years old. From the test experience and the data, I was pretty sure they were toasted. I took them in to Batteries Plus for testing, and they smoked during the load test. So they're done. Luckily, the guy who donated the first set has a second set available for us, so that's not a show stopper.

    However, the motor is dead. I suspected after we weren't able to get the speed we expected out of the boat during our last test that it had the wrong prop on it. Trolling motors are generally propped to drive a heavy boat slowly, so with the lighter and faster boat, it just was not up to the task. In order to properly size a new prop, I had to measure the motor constant.

    Sadly, I don't have any picture of my setup -- I was using an IR diode with an IR remote receiver mounted in a breadboard and the prop as an interrupter. I drove the LED at the required 38 kHz with an Arduino. I measured the back EMF with a multi-meter and the pulse rate out of the IR receiver with my Saleae. I chucked the prop nut into a drill to drive it. I measured the Kv just fine -- 420 RPM and 2.5V for a Kv of 168 RPM/V, pretty much as expected from online discussions.

    I then went to measure the DC resistance through the motor. Nominally, this motor draws 30A @ 12V when at full throttle. I expected a DC resistance commensurate with those numbers. However, I measured 10 ohms. This means the motor is most likely dead. This would explain why the boat slowed down dramatically in the last half of the test.

    A new trolling motor would be about $100. However, we decided that it's long past time to make sail development our highest priority, because that's what's going to get us around the world. We filled and sanded the first wing this past weekend, so it's just about ready for paint and final electronics fit. The second one is waiting on its leading edges for final assembly. We'll go back to power if we really need it for something, but for now, we're a sailing operation from here on in.

  • Successful Test!

    Pierce Nichols06/12/2017 at 05:03 0 comments

    We took the boat out for longer and farther than we ever have before. The boat successfully ran a set of waypoints and demonstrated virtual anchoring. We were going for a second run of our waypoint set when the boat started to slow down. We thought at the time that it might be due to a declining battery, but hand measuring the cell voltage before and after the trip casts some doubt on that idea, especially since we were only out for about half the time the batteries ought to last. Once i dump the boat data I can graph the motor current and voltage and see where we're really at.

  • MFBA2017 Slides

    Pierce Nichols05/24/2017 at 15:40 0 comments
  • MakerFaire Bay Area 2017

    Pierce Nichols05/19/2017 at 06:10 0 comments

    I'll be talking about Project Ladon at MakerFaire Bay Area this Sunday at 3:30 on the Make: Show and Tell stage. Drop by and say hi!

  • 2017 Apr 09 Autonomous Test

    Pierce Nichols04/18/2017 at 04:24 0 comments

    We took the boat out on the water for a test the weekend before last. Check out our blog post with details, including maps:

  • 3D Printed Sails

    Pierce Nichols02/15/2017 at 22:38 0 comments

    Code for the big boat has been taking up most of my time, but in the mean time I've still been working on the sails for the little boat.

    The original sail design didn't work -- I couldn't get enough weight on to balance it against the overly long lever arm. The airfoil shape is also not great, because my first shot at hot wire cutting and using heat shrink film didn't turn out so well.

    As a result, we're working on some new wings. One of the ideas I am pursuing for them is 3D printing in ABS. To that end, I've acquired a 3D printer (one of the $300 Monoprice ones, if you're curious) to help with building the next set of test sails for the little boat. The printer has largely worked very well, especially for the price, but the delamination was awful. I solved that with a quick box made of pink styrofoam panels and hot glue. It's neither pretty nor clever, but it works. It's just five 2'x2'x1" project panels hot glued together.

    Putting the printer on the concrete floor rather than the rickety table helped as well. Here's some of my test prints:

    The dog-bone was printed inside a box and then finished with cold acetone vapor, which works amazingly well. The black coating is black ABS dissolved in acetone and painted on. It works, but it's heavy. This was part of my original thought, which was to 3D print everything except a spar to hold the whole thing together. I don't think this is the right way to go, because it will take approximately forever and a day to print the whole damn thing.

    Luckily, Autodesk just ported Slicer over to Fusion 360, which makes it simple to turn a solid body into a grid of laser cut pieces. I can then skin that with either very thin plywood or heat shrink film. I will probably go with the plywood, because I think I can apply that with a thin film of glue and heat shrink tape acting as a poor man's vacuum bag.

  • Software Update

    Pierce Nichols01/25/2017 at 16:31 0 comments

    I just realized we haven't posted an update in a while, but I promise we aren't dead -- we've been working on software. Check out the network graph on our github (all the recent action is on the new-hardware branch):

    We had a solid in-water test in October that verified the new electronics work well and that we can drive the boat around by remote control and that it will steer to a course on its own.

    Most of the recent action has been filling out the various boat states and writing unit tests for everything. Just writing the tests has kicked up lots of bugs that have been duly fixed and make me far more confident of our code than I was before.

    Along with the other changes, we've just acquired a Beaglebone Green Wireless as our latest brain. This has built-in wireless (replacing the HDMI) and a built-in four port USB hub (replacing the Ethernet). Since we're not currently using either of the deleted peripherals, this is nothing but win. We now have an on-board port free to plug in the AIS and three spare ports for other instrument or harddrives. On the around the world boat, we're planning to plug in three external harddrives and arrange them in a RAID array for storing mission logs and photos.

    However, I discovered a little wrinkle. The BBGW uses the eMMC pins for the wifi module. This is a problem because in a bout of thick-headedness I double-booked those pins to drive the throttle relays. That means that I can't use it on this hardware revision. Another kick in the ass to get the next revision going.

    The software to the point where we are ready to do some waypoint navigation testing. The gating item right now is getting a day that works for the whole team and when we have access to a powered chase boat. Paddling along in a kayak isn't going to cut it for the waypoint following, especially in the middle of winter. Falling into Elliot Bay would be a very, very bad thing at this time of year. The second weekend in February is looking good.

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Phil G wrote 06/29/2016 at 07:38 point

hey dude! I saw you out on Alki recently while I was launching my (formerly autonomous) jet ski. I have a fair bit of experience creating systems like this, and built a small fleet of hive aware 16 inch watercraft for "research"purposes. I spoke briefly to one of the dudes launching- you guys should totally use Mission Planner and a pixhawk, once you get it nice and tuned, you could circumnavigate the planet within the next six months. I spotted a few reliability issues regarding power, direction and locomotion that I'm sure you're aware of already, and I wish you guys the best of luck!

  Are you sure? yes | no

Pierce Nichols wrote 07/16/2016 at 16:29 point

That sounds awesome, do you have anything about the project up on the web? Most of our current problems are due to incomplete software, much of which we've greatly improved in the past couple of weeks. 

I'm not a fan of MAVLink based stuff. I am looking at ROS these days, because there is so much available in the way of navigation, sensors, and analysis tools available to go with it. It will probably come in through the nav door this fall and winter. 

We were planning to launch again today, but a sick team member and a broken part put an end to that. :(

  Are you sure? yes | no

physiphile wrote 06/18/2016 at 16:32 point

I've been designing something similar but in a submarine. I think it would take a lot less power if you went under the water. I would keep it under 3 cu.ft for power/weight reasons and durability.

  Are you sure? yes | no

Pierce Nichols wrote 06/20/2016 at 02:32 point

It might use less power, but it also has less access to power under the water. :) There's also issues with communications. The most successful autonomous submersible I'm familiar with, SeaGlider, surfaces regularly to handle both issues. 

  Are you sure? yes | no

physiphile wrote 06/20/2016 at 17:24 point

Yup so you could have it rise to the surface to send/receive data but most of the travel would be dead reckoning to get to the next communication point.

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Pierce Nichols wrote 05/31/2016 at 20:49 point

I find it interesting and slightly weird that most autonomous boats use Bermuda rigs with cloth sails. The luffing boundary condition (and related failure modes, such as falling into irons) in particular strikes me as borrowing trouble. 

  Are you sure? yes | no

physiphile wrote 06/20/2016 at 17:29 point

The durability goes down with size. Keeping a small tight package is the way to go if you don't want the sea to rip it apart. Don't need fancy sensors, just good algorithms and solid communication.

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Ashley wrote 05/28/2016 at 17:51 point

hi all

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Pierce Nichols wrote 05/28/2016 at 17:52 point

Thank you; that looks like a really interesting thesis. 

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Jack Wells wrote 05/26/2016 at 14:45 point

Do you guys have a plan for getting data back when the boat is in the ocean? Or is it "fire and forget" where you hope it turns up at the otherside. Obviously GSM will handle shorline in some areas. I ask because we're working on a project to make use of the iridium satellite network. Maybe you could check out Rockblock/Rockseven for an off the shelf solution. Major downside for your application is the iridium modem uses a fair wack of power. 

  Are you sure? yes | no

Pierce Nichols wrote 05/26/2016 at 16:16 point

Yes -- we'll probably have both satcom and HF. We've decided to push a decision on how exactly to do it until closer to when we are ready to go. There's a fair amount of activity in the satcom industry these days, so it makes sense to wait and see what's available... and more importantly, who might be willing to give us hardware and/or bandwidth for free. 

Power consumption is less of an issue than it might first appear, as long as you can boot up the satcom quickly. The duty cycle can then be set to whatever the power budget will support. If we have both shortwave and satcom, we can cue the satcom via HF when we want to make contact out of the normal sequence. HF listening is a pretty low-power endeavor, so that should work well.

  Are you sure? yes | no

silvio biasiol wrote 04/14/2016 at 20:30 point

It's a shame you didn't continue it! If you change your mind or need some help with coding and suggestions please contact me :) I'm working on an autonomous boat too :)

  Are you sure? yes | no

Pierce Nichols wrote 04/14/2016 at 20:34 point

Hackerboat is definitely a continuing project! Most of the recent action has been on our github repository. We're debugging software so we can put it back in the water ASAP. We're also going to give it a decent paintjob this weekend. 

I suck at blogging; I'm going to try to be a bit better about posting updates... starting tomorrow. :)

  Are you sure? yes | no

silvio biasiol wrote 04/15/2016 at 07:34 point

Cool! Can't wait to see that! :D

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Pierce Nichols wrote 11/22/2015 at 07:23 point

There's more recent history and details that I need to add, but not tonight because it's late.

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borazslo wrote 04/11/2016 at 17:07 point

It is never too late to add those details. :)

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Bobby Christopher wrote 11/22/2015 at 07:11 point

Super cool! Can't wait to see more on this!

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