How to Launch Arducopter, IRIS, or SOLO from a Boat

Posted by Robert Giordano on September 11, 2015 at 9:41pm

Recently, I was asked to shoot some stills and footage of a sportfishing yacht for a client. We went out on a beautiful morning with no wind and an almost perfectly calm ocean. If you wanted optimal conditions, its wasn't going to get much better than that morning.

I connected the battery to my custom built quadcopter running APM 2.6. It would not arm. We were sitting about 4 miles off shore, not moving, gently rocking on an ocean about as calm as I've seen it. I was trying to launch from the middle of the lowest platform of the boat, at the stern. I had good GPS. Everything else checked out. It would not arm.

As soon as I got back to dry land, I tried it again. It armed without hesitation. Apparently Arducopter needs to be on solid ground to initialize. So what next?


Arducopter 3.3

In doing my research, I found this thread:
http://diydrones.com/forum/topics/launch-and-recovery-from-boat

Chris Anderson says, "Starting with 3.3, calibration on a moving surface will be easier. As far as the gimbal goes, it depends on the make. The 3DR Solo gimbal will calibrate on a boat, but not all will"


I have two points here. First, the gimbal is not an issue for me. Simple BGC lets you turn off the startup accelerometer calibration. It still works fine if you don't let it calibrate every time. Second, I'm using APM 2.6 so I'll have to upgrade to Pixhawk if I want to use Arducopter 3.3.


Arm on Shore first

Next, I found this thread:
http://diydrones.com/forum/topics/launching-from-a-moving-boat-can-it-be-done

The first person to comment boots his quad on shore, then takes it powered up, in his kayak. I see where that could work but that only gives me the use of one battery.


Bring a Laptop?

Considering the idea of calibrating on shore, what if I brought my laptop on the boat with me? I could power up on shore then launch from the boat and fly the first battery. After I return to the boat, I could connect APM to the laptop with USB, then disconnect and swap the flight battery for a fresh one. Would this work? I will do some experiments and post the results on this thread.


Dynamic RTL is a Separate Issue

I've already posted the desire for Dynamic RTL, where the copter returns to YOU instead of the original launch location. Obviously this is desirable for any mission launched from a boat. It seems like a much easier feature to add. The Tower app already knows your GPS location in order to do "follow me" mode. The DJI Inspire already has this feature. My thread is here:
http://diydrones.com/group/arducopterusergroup/forum/topics/dynamic-rtl-can-apm-or-pixhawk-do-it-can-tower-do-it-dji-inspire


I will post more information as I find it. Hopefully this thread will be a resource for those wanting this feature.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

  • Robert Giordano September 11, 2015 at 10:04pm

    "Boat Mode" on MikroKopter

    On http://mikrokopter.altigator.com/boat-mode-take-off-from-a-boat-n-3... it says:

    Since the version 2.08, MikroKopter has a "boat" mode which has been especially developed in order to solve the takeoff problem on a platform that is in motion (like a boat, or every other moving landing surface).

    This method uses as reference the last values of the gyros that were saved during the most recent initialization made on the mainland. It is therefore important to have completed this process (initialization) during the last 1 or 2 days before, because these sensors are quite sensitive and unstable in medium term.

    The article continues by showing a special stick configuration that arms the copter in "Boat Mode". It seems like it wouldn't be too difficult to implement this feature. The code might include "safety rules":

    - The timestamp of the last saved values must be within the last n hours. (n defaults to 3? (i.e. a "3 hour tour")

    - Loiter cannot be used for launch unless the speed of the boat/platform is close to zero (less than 1m/s?)

    - In "Boat Mode", RTL would automatically change to "Dynamic RTL" if the telemetry radio is connected.

    Boat mode: take off from a boat
    Sometimes drone users wish to be able taking off from a boat. Even for very large ships, a boat is somehow always moving. Before starting to fly…
    • MR60
      Forrest Frantz > Robert Giordano September 12, 2015 at 7:19am

      Tall grass?  If using a multi-copter to photo waterfalls in the mountains, how is one supposed to take off in tall grass on a knoll?

  • Robert Giordano September 11, 2015 at 9:49pm

    Discussion on 3DRpilots.com

    http://www.3drpilots.com/threads/boat-mode.1179/

    This is an interesting discussion. Someone raised the point that if you're moving and you take off in Loiter mode, the quad could slam back into you or the boat. Well, this just confirms my previous post. I want to take off from a STATIONARY vessel and I certainly want to be LANDING on one as well.  =)

  • Robert Giordano September 11, 2015 at 9:47pm

    Ardupilot on GitHub

    On https://github.com/diydrones/ardupilot/issues/1361 it says:

    There are two risks for arming and taking off on boats. The first one is that the gyro calibration will likely fail. It'll go with it's best guess which is likely ok most of the time but at least one case has been reported where the vehicle got a case of "the leans". I.e. the pilot had to keep pulling further and further back on the pitch stick to keep it level... eventually there wasn't enough stick left and it flipped over. This is because the gyro calibration didn't work very well. Plane has a parameter that allows skipping the gyro cal, we don't have it in copter although it's easy to add.

    The 2nd less risky issue is the pre-arm checks will fail if it thinks the vehicle is moving over 50m/s (i.e. 1.5feet / second). This can be disabled by setting the ARMING_CHECK to Skip INS.

    For Landing there may be an issue with the landing check's 30deg/sec rotation rate not being passed meaning the vehicle cannot be disarmed in AltHold or Loiter.

    Looks like more reasons to arm on shore, then keep it powered while on the boat. Also, I think it would ALWAYS be best to take off from a stationary boat, rather than a moving boat. I can imagine situations where you don't have control over the boat coming to a stop for you, but then I question whether you should be trying to fly in those situations.

    • Federico Boldori > Robert Giordano September 19, 2015 at 5:09am

      Hi, you dont need a laptop. Buy some cellphone usb battery charger. I use them to power my iris+ for ten minutes before every flight to warm up the board. Then i connect the battery and unplug usb.

      You could power it on the shore with usb. Wait some minutes to get it warmed up and reboot it for better sensor calibration. Then with the usb plugged go on the boat. When you are ready plug the battery, disconnect usb and fly.

    • Robert Giordano > Federico Boldori September 21, 2015 at 7:10am

      Hey Federico! I just did a number of successful flight tests using my "boat simulator" and my laptop. Please see this post!

      Also, I thought about using a USB phone charging battery and I have several of them. Its a good idea. The problem is, I don't want to take a chance plugging an untested power source into my flight controller. I would rather have an engineer who knows the actual specifications of the board, tell me if that's a safe option.

      Also, we're talking about APM and Pixhawk boards. One may work while the other could fry.

This reply was deleted.