Opencpn to Seatalk and SeatalkNG

[Moo]

Originally Posted by mikedefieslife

Hi Moo,

In the post I quoted you were replying to Douwe Fokkema not the OP.

Douwe Fokkema seems to have a problem with the Evolution pilot picking up waypoints from OpenCPN. I have the same issue. Thanks very much for the offer of help, it's probably best left to another thread more specific to the Evolution system to avoid the confusion like we've been having.

OK so Douwe was not the OP my bad, I this thread is quite old; but the point is that my post (which included the comment "you are missing something" but was not limited to that) helped him/her solve their problem, they needed to send position too.

I do not participate in any other forums here on Cruisers, too many idiots and trolls, and draconian censorship when you call somebody out. You can PM me or sometimes find me on Sailing Anarchy where one can speak freely

[Douwe Fokkema]

Yes, my Evolution pilot goes into Track mode now (finally). So I lay out a route, boat exactly on the route. Display shows XTE = 0, as it should. BTW is shown right on the control head, and is identical to the heading.

I switch on Track. Pilot asks confirmation and I confirm. Then the pilot initiates a 30 degree turn! Rudder hard over. Completely wrong direction. Disable pilot.


But otherwise it is a very good pilot. Better forget about Track mode. I will try to adapt the autopilot_route plugin to interface it to Raymarine, so that I can follow routes automatically.

[boatbod]

My old Raymarine S3G does the same nonsense whenever it thinks the XTE is slightly off. It seems that priority is given to cross track correction rather than considering bearing to waypoint.

[rgleason]

Douwe, so in short, the Evo has some issues in track mode, with OpenCPN.
I am considering that as replacement for my 21 yr old ST4000 wheelpilot, because the B&G autopilots are overkill for this boat (have b&g zeus touch 12 cp).

Sean's autopilot-route_pi has several different modes, one making virtual waypoints rather than using crosstrack error. Maybe it will work out of the box in one of the modes?

[rgleason]

The other alternative would be to use the wheelpilot motor and eheel and get Sean's pypilot controller which might be better with Opencpn.

[fgd3]

Originally Posted by Douwe Fokkema

I switch on Track. Pilot asks confirmation and I confirm. Then the pilot initiates a 30 degree turn! Rudder hard over. Completely wrong direction. Disable pilot.

My Raymarine autopilot works the same way. Put it in track mode and it puts the rudder hard over. After a few seconds it puts the rudder hard over the other way. Then it settles on course and does a creditable job tracking to the waypoint. I think it is searching for the course line and testing how fast it can return to it.


Try giving your autopilot a little more time to hunt for the proper course before you disable it. I'd like to know if it behaves the same way mine does.


I very seldom use the Track feature for that reason. My old GPS has a screen that showed bearing to waypoint and track. I could instantly tell how many degrees I needed to alter the autopilot setting to make the track the same as the bearing. By monitoring cross track error from time to time I could make sure I was still steering to the desired waypoint.


Fabbian

[Moo]

Originally Posted by Douwe Fokkema

Yes, my Evolution pilot goes into Track mode now (finally). So I lay out a route, boat exactly on the route. Display shows XTE = 0, as it should. BTW is shown right on the control head, and is identical to the heading.

I switch on Track. Pilot asks confirmation and I confirm. Then the pilot initiates a 30 degree turn! Rudder hard over. Completely wrong direction. Disable pilot.


But otherwise it is a very good pilot. Better forget about Track mode. I will try to adapt the autopilot_route plugin to interface it to Raymarine, so that I can follow routes automatically.

Make sure that you zero the cross track error before you enter track mode.

When you are in route mode the AP tries to drive exactly along the route (track) rather that to the waypoint from your current location.

[Moo]

Originally Posted by rgleason

Douwe, so in short, the Evo has some issues in track mode, with OpenCPN.
I am considering that as replacement for my 21 yr old ST4000 wheelpilot, because the B&G autopilots are overkill for this boat (have b&g zeus touch 12 cp).

Sean's autopilot-route_pi has several different modes, one making virtual waypoints rather than using crosstrack error. Maybe it will work out of the box in one of the modes?

Nothing to do with OCPN Rick. It is just the logic in the pilot. I it does the same for a route programmed in via a Raymarine plotter. Track mode is exactly that it tries to drive along the programmed track and is different behaviour than a simple "goto" waypoint.

The Ray pilots are quite good value for money and evolution heading sensor so much better than the old fluxgates.

[Captain Bill]

When I got my new autopilot 4 years ago I nicknamed it Crazy Ivan because it often did a 30 decree turn when the track error exceeded .01nm (about 60 ft) which if things weren't perfectly aligned when you hit the track button it was quite easy to do. After many complaints to support they finally produced a software update which did not cause a 30 degree turn unless the xte was .1 nm. at .01nm it only does a 10 degree correction to center on the track. I fear you guys having the problem need a software update. The bad news is you can only apply a software update with a Raymarine MFD. If you are using opencpn and don't have a Raymarine MFD then maybe you can borrow one from a friend.

[Douwe Fokkema]

Originally Posted by rgleason

Douwe, so in short, the Evo has some issues in track mode, with OpenCPN.
I am considering that as replacement for my 21 yr old ST4000 wheelpilot, because the B&G autopilots are overkill for this boat (have b&g zeus touch 12 cp).

Sean's autopilot-route_pi has several different modes, one making virtual waypoints rather than using crosstrack error. Maybe it will work out of the box in one of the modes?

Rick,


I also had a 4000 before on a previous boat. It had the same "track" behavior as the Evolution, difficult to start, steers wrong way, then exactly on track. But you often lack the space to allow is its wrong initial behavior. The EV1 based pilot is much better than the 4000, steers excellent on waves, really anticipating through its acceleration sensors. I feel the tracking behavior should be cured with our own software, like Sean's autopilot_route.


So I adapted the autopilot_route to handle the Evolution pilot. Sending heading commands through an Actisense NGT-1 (NOT the NGW-1) directly to the pilot. I earlier decoded these proprietary PGN's. Here I used the route position bearing mode. This worked quite well with short routes. With long routes (> 100 WPt's) Seans software can't handle it. It calculates the distance to every segment in the route every second, killing the system. Further I like the route handling of OpenCPN better than Sean's route handling. OpenCPN just focuses on the current segment and provides steering info for that. And I really like the functions Zero XTE and Activate Next WP. OpenCPN has it standard. But Seans handling at waypoint turns is better.
I now made a version that is completely based on the OpenCPN route handling. From the XTE as provided by OpenCPN it derives a next position on the route to steer to (idea of Sean). I might have to add an integration term for correction of cross currents. I have a first prototype (just) ready, sea trial tomorrow.



Douwe

[Douwe Fokkema]

Though my previous message does somehow fit the subject of this thread, I realize it might better fit under the Autopilot_route thread. I will copy it to there as well, so that a discussion can be continued there.
Douwe

[rgleason]

What a great wealth of information from Moo, Douwe, fdg3 -fabbian and capt.

"The Ray pilots are quite good value for money and evolution heading sensor so much better than the old fluxgates."
--Agreed. The heading sensor alone would be a good improvement as radar overlay is also improved.

The idea to zero out xte first is good to prevent dramatic starup action.

The improvements and details about use with ocpn and autopilot_route_pi are very helpful.

If boat dollars were more plentiful I would probably have an purchased an Evo by now.

[boatbod]

Zeroing XTE always has been a necessary evil with Raytheon/Raymarine. Even their RL series plotters had a soft key dedicated to this purpose.