Subject: Re: HP Autopilot
From: Mike Crawford
Date: 12/7/2018, 2:40 PM
To: harryproa@yahoogroups.com.au

Jeff,

  This is pretty exciting, actually.  I've been uneasy with instrumentation for a long time, not having a good option for finding a way to switch directions with a single set of instruments.

  I suppose I could get my own raspberry pi and program it, but that's a big black-box mystery to me at the moment.  I'm sure the code would make sense after seeing a few examples (I develop software for a living), but since I haven't actually rolled up my sleeved and started playing with a unit, I can't yet view it as a viable option.

  But a unit that already has it's sensors and autopilot programming in place should be very simple to modify.

        - Mike




Jeff Royster jeffroyster@gmail.com [harryproa] wrote on 12/6/2018 2:21 AM:
 
(I wrote this on a plane a few days ago but looks like it didn't go through, sorry if this ends up being a double post)

I've been giving the overall subject a bit of thought myself, though mostly thinking of tiller pilots and wind vanes.  HP's are still abstract to me, but I've read several notions of setting the rear rudder for balance and steering with the front. 

With that in mind, a tiller pilot on each rudder seems feasible, even if only the front one is active for either direction.  Of course tiller pilots arent known to be as reliable and sturdy as a good hydraulic system, but hydraulics seem a bit overkill for a 40ish footer I'd be interested in.  Dual windvanes would be both expensive and busy.  Not to mention clumsy if you had to switch on each shunt.  So its good to hear the 18er works fine steering either rudder.

Since I will be building my HP, I quickly fell down the rabbit hole of self built wind vane designs which could be feasible for either or both rudders.  Looking at simple self built designs made me embarrassed to see what hydrovane charges. 

In the true spirit of DIY, the pypilot project comes to mind.  Its all open sourced hardware and software for autopilot via openplotter on a raspberry pi, so theoretically someone (not me anytime soon!) could sort out the software side of bidirectional autopiloting.  The logic at least doesnt seem too difficult to put into human words..  Having a little experience with Raspberry Pis and home automation I can actually imagine several proa applications, such as automated nav light switching.

Whatever I end up with it will be DIY and/or used and steeply discounted.  With the economy built into HP's you could spend as much on all the modern gizmos as you do on structure.  Yachting is predominantly a rich man's game, but the underlying tech need not be.

On Tue, Dec 4, 2018, 1:02 AM Rick Willoughby rickwill@bigpond.net.au [harryproa] <harryproa@yahoogroups.com..au wrote:
 
The 18m proa was fitted with hydraulic steering two years ago.  That enables fitting an autopilot with hydraulic pump to the system.  The system operates one rudder and that works fine for steering in either direction.  We have only played around with the autopilot twice.  The incorporated GPS and radar have been more useful to date than the autopilot.  We are yet to resolve how the autopilot can be set to work in reverse without recalibrating each shunt or have a reversing switch on the pump motor.  There may be a simple software switch for the reversing function but that has not yet been found if it exists.  Generally manufacturers of autopilots have not contemplated their use on a proa.  

Setting the pump up was a simple exercise with the existing hydraulic steering.  The pump has in-built check valves so it does not need to be isolated to steer by hand but the helm needs to be isolated so the rudder turns in preference to the helm spinning.  The helm could be locked in place but it is simpler to use an isolating valve.  

The hydraulic steering was quite simple to set up and not particularly expensive using the same orbital pump/motor for the rudder and helm.  The steering design would be a bit different if done again but the system has proven reliable.  

Rick

On 4 Dec 2018, at 4:18 pm, ryanonthebeach@gmail.com [harryproa] <harryproa@yahoogroups.com.au> wrote:

Has anyone solved the autopilot problem with an HP?
As much as I'm a fan of tiller steering, handling two tillers far apart adds a challenge. Some purists may disagree, but I believe an autopilot is as mandatory as GPS on a bluewater sail, especially if single handed. 
Curious if anyone has managed to get a reversible autopilot working well with the daggerboard rudders on an HP?
Thinking two hydraulic arms for steering both ridders simultaneously connected to something like a seastar helm and autopilot pump... flip the heading sensor 180 after a shunt? And the pump wires? Or use an open center hydraulic valve to reverse the hydraulics (advantage of valve is having a neural gear to free the tilers for hand use) 
Have had hydraulic steering and autopilot pump before and it worked flawlessly.. so pretty confident in the reliability and maintenance of it.