Automatic Foil Control Systems

Discussion in 'Multihulls' started by Doug Lord, May 11, 2017.

  1. Doug Lord
    Joined: May 2009
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    Doug Lord Flight Ready

  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa Beach, Florida

    Doug Lord Flight Ready

    Update: DNA G4: Updated automated foil control system Test | Catamaran Racing, News & Design http://www.catsailingnews.com/2018/03/dna-g4-updated-automated-foil-control.html#more

    [Martin] asked Jasper van Staveren who took the pics about how stable the G4 was on that session: "It did sail stable indeed (and fast) the further they sailed from Lelystad towards the West it got bumpier and they had an amazing steady course. We were doing 30+ knots in the rib but couldn't overtake them anymore at that stage"

    More pics and details at DNA website: dnaperformancesailing.com/ice-sailing-the-g4/

    G4 with automatic foil control:
    DNA-winter-testing-G4-with-automated-foil-controls-144.jpg
     
  3. bjn
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    bjn Senior Member

    As I understand it, the G4 has an automatic anti-capsize system based on a gyro and some actuators. But the foil angles are controlled manually with buttons.
     
  4. Doug Lord
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    Doug Lord Flight Ready

    bjn, see the video in post #1--they have electronic rake control for the foils--automatically adjusts the angle of incidence of the foils among other things. Manual control is also possible port and stb.......
     
  5. bjn
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    bjn Senior Member

    As I understood it, the rake control would be activated when the anti-capsize system was engaged.

    They have all the hardware for a closed loop "flight height and stability" software though, so it's only a matter of choice whether they would make such software active during normal sailing. They might do that, but that is not what I understood from the video.
     
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  6. Doug Lord
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    Doug Lord Flight Ready

    New video from DNA and catsailingnews.com showing more of the boat sailing with fully automatic foil control:
     
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  7. OzFred
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    OzFred Senior Member

    Again you are taking things out of context. The expression "automated foil control" does not necessarily mean "fully automatic foil control".

    You may be right, perhaps it is "fully automatic", but that isn't the term DNA are using, anywhere, so nor should you.
     
  8. Doug Lord
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    Doug Lord Flight Ready

    DNA: " we need to test the latest updates of the automated foil control system." Combined with the video that talks about automated rake control, yes it is "fully automatic foil control".
     
  9. bjn
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    bjn Senior Member

    I think that the videos which shows the boat foiling nice and steady does give the impression that the foils are continuously controlled by a software which is reading a number of sensors for feedback to the control loop. I would be happy to learn that they have achieved that. I'm a software and controls guy myself, so I fully understand that it is possible to create this software, and I like the idea. To create such software is more or less the first thing guys like me think when we see the footage of foiling boats oscillating up and down, jumping, and crashing. So if DNA has done this software, I'm happy for them.

    You keep referring to a video from last year, as the source of your claim that they have "fully automatic foil control". I spent 10 minutes to make a transcript of the video, to make discussions easier:
    Could you please point us to the line where they are claiming "fully automatic foil control"?
    Or have you communicated with someone who provided more info than presented in the videos and posts on catsailingnews.com?

    Their claim that G4 can be sailed by only two sailors, and the nice videos of the boat flying along with two guys sailing, and four guys on the gunwhale with nothing to do, enjoying the sailing (like if they where on the gunwhale of a monohull sailing upwind at a nice and steady speed) is a much stronger indicator to me, that they have a foil control software working.

    On the other hand, they are sailing on a lake in recent videos, so can't be a too bad sea state. And the video cuts to a new sequence as soon as the boat seems to get into the slightest of trouble. So we can't really know how stable it is, or if rake is controlled by software. Again, to me, the transcript above only indicates that they have a fully automatic system to release the sheets and "take 'er down safely" when it's about to get into a dangerous situation.

    By the way, what are those pedals seen at 3.13 in this video from 4 month ago?:
     
    Last edited: Mar 16, 2018
  10. Doug Lord
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    Doug Lord Flight Ready

    They say that there is electronic rake control and they say "... which will also adjust the rake." And the title of the video says it all: ".... the automated foil control system". That is not ambiguous and clearly means that the boat can be sailed with fully automated foil control.

    PS- thanks for the transcript!
     

  11. bjn
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    bjn Senior Member

    I agree, but when the info in the video doesn't mention automated control in the context expected, the conclusion I draw is that it likely doesn't exist.

    Because automatic can mean so many things. For example, it can mean that the foils are deployed automatically, similarly to automatic power windows in a car. In the car, a short push fully opens or closes the window, and stops the movement if there is an obstruction. That's it. An automatic power window doesn't continuously control the window opening to maintain a set temperature and humidity inside the compartment, for example. An automatic climate system can do that though. But sometimes only temperature. Automatic can mean different things, and we don't know how it is defined and implemented in this boat.

    About "electronic rake control", to me this only implies that the rake angle is controlled by an actuator powered by electronics. The signal to the electronics could come from a knob, pedal, button, simple ECU software, or sophisticated ECU software, but we don't know. It doesn't seem like the actuator is based on hydraulics, due to their distinction. Could be based on a lead screw and a motor, perhaps.

    About "which will also adjust the rake", to me that is clearly in the context of when the "emergency system" has been activated. Could be that the foils are set to an angle of no lift.
     
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