Evolution AP not steering to waypoints without getting lost

[Seacom]

I'm helping a customer troubleshoot his Raymarine system and it seems to have an odd quirk. If we enable the autopilot to hold a course, it will do so tirelessly and very well for any duration of time. If we enable the autopilot to steer to a waypoint, even on the exact same heading, it does so flawlessly for the first few minutes, then suddenly veers off and starts doing a bit of a zigzag around the heading line before resuming it even tho ours hands are not touching anything at all. The MFD that is supplying the waypoint data is an E127, both units are fully updated and a proper dockside was completed, a seatrial was done and there was 4 degrees of deviation on the compass sensor.

The attached image shows a (left side) track going in a NW direction, this was us using the AP to hold a course. We then used the P70R to redirect our heading until we had fully turned around and began the (right side track) SW part of the trip. Once we had that line established, roughly 150 degrees true heading, I placed a waypoint a mile or so ahead of us on the same vector. I put the AP in standby, and reengaged it with a Goto Waypoint instead. It picked up its heading, followed that course for a good 3-5 minutes or more, then randomly began some zigzags before straightening itself out again and holding the completely wrong heading, at which point we stopped our trip and headed to dock. There was only the 2 of us onboard, and we were upstairs on the flybridge when it all happened.

While underway I checked the EV compass sensor, it is still showing a green light on the heading, it is installed correctly, and there is no metal objects of any kind within 3 feet of it, and that closest object is the AP processor itself.

If it matters, prior to upgrading to the E127, he had a C80 Classic, and when using it to steer routes and to waypoints via the same Evolution AP it never failed him once. When the E127 was installed, I did software updates all around including the AP, thru it. I also redid the dockside and compass calibration routines before putting it into active use. This zigzag problem was not a one off, it happened to him every single time he enabled a waypoint to steer too, and never once left it's heading if just holding a course without waypoints.

[Steve - Raymarine - Moderator]

First questions I would have with this is, what is the Response set at? Performance, Cruising or Leisure? Next would be the Speed Input setting with the latest software you have 3 options, Speed, SOG and Cruising Speed. I would recommend it be set to SOG with the e127 connected.

[Seacom]

(04-14-16 11:59 AM)Steve - Raymarine - Moderator Wrote:  First questions I would have with this is, what is the Response set at? Performance, Cruising or Leisure? Next would be the Speed Input setting with the latest software you have 3 options, Speed, SOG and Cruising Speed. I would recommend it be set to SOG with the e127 connected.

Cruising performance. I never made any changes to the speed input setting, so the best I can say there is whatever the default would be. There is no speed wheel installed, so I'm assuming it's using heading/GPS position to derive SOG. Are not both cruising speed and response settings part of the autopilot itself, not the MFD? Because the AP works fine by itself and worked fine when being steered by a C80 thru NMEA/ST out, it's only when adding the E127 into the equation that it started acting up, and only when steering to a waypoint. I never saw it do this when using GoTo cursor, but it's a tough call to say it wouldn't as it takes so long to go squirrely, it's plausible it may have eventually.

How speed input settings could affect it's ability to hold a straight line 5 minutes into it is beyond me, but that's not really the point I suppose. Also not sure how/why when it started doing this randomly after holding a steady line for a good 5 minutes and we were still probably 20 minutes away from the sole waypoint, it did the zig zags you can see, then settled in and went back to holding a steady line... that was a good 30 or so degree's off course from where it's programmed to go which would take us into shore in no time were we not watching our bearing. Yet when looking on the MFD, it still read that it was steering to the named waypoint off in the other direction. And to confirm, yes the rudder reference is correct, Port is port, SB is SB, and that was confirmed on that very trip before any problems displayed themselves.

[Steve - Raymarine - Moderator]

These options would make a difference when using the Track function because the autopilot is steering to a course or rhumb line (XTE cross track error) as opposed to just a heading in Auto. The default would be the Speed, so make sure it is set to SOG, and it could be effected that far down the line because of the change in course by current, side wind, side waves and this is when the autopilot is trying to correct causing the S-ing.

How was the C80 connected? Through a Seatalk to Seatalk NG converter or through a NMEA converter? The C80 would not have a direct connect to a Evolution autopilot it doesn't have Seatalk 1 or NMEA 0183 inputs?

[Seacom]

(04-14-16 01:53 PM)Steve - Raymarine - Moderator Wrote:  These options would make a difference when using the Track function because the autopilot is steering to a course or rhumb line (XTE cross track error) as opposed to just a heading in Auto. The default would be the Speed, so make sure it is set to SOG, and it could be effected that far down the line because of the change in course by current, side wind, side waves and this is when the autopilot is trying to correct causing the S-ing.

How was the C80 connected? Through a Seatalk to Seatalk NG converter or through a NMEA converter? The C80 would not have a direct connect to a Evolution autopilot it doesn't have Seatalk 1 or NMEA 0183 inputs?

We were facing a fairly strong sidewind now that you mention it, and the waypoint in question is off the end of an island so could easily have strong winds around it the other times he had this happen when I was not on board. I'll make a trek down to his boat soon to verify these settings. Do you know where in the menu I should look to make sure i'm checking the right setting?

As for the C80, it was ST1 out and into a Raymarine ST to STNG converter (yellow plug) into the EV.

[Steve - Raymarine - Moderator]

The button presses are Menu>Response Level for the Performance/Cruise/Leisure, then Menu>Setup>Autopilot Calibration>Vessel Settings>Speed Input.

[Seacom]

(04-14-16 03:28 PM)Steve - Raymarine - Moderator Wrote:  The button presses are Menu>Response Level for the Performance/Cruise/Leisure, then Menu>Setup>Autopilot Calibration>Vessel Settings>Speed Input.

I've confirmed that it is indeed set to Cruise. I can not confirm the Speed Input setting however as that is not an option in the screen that you directed me too. Under Vessel Settings the only options in the list are Vessel Hull Type, Drive Type, Compass Offset and Calibration Lock. I have a screenshot of this if you need it. I did find an option to set the Speed under Data Sources (in a list with Heading, Depth, etc) and it had 2 choices for me, Auto and E127 (which is my GPS source from the internal GPS antenna), and the E127 was already selected.

[Steve - Raymarine - Moderator]

That would confirm you don't have the latest software in the autopilot. Make sure you upgrade the software and get back to us with the performance. The latest software makes a lot of track improvements.

[Seacom]

(04-15-16 07:24 AM)Steve - Raymarine - Moderator Wrote:  That would confirm you don't have the latest software in the autopilot. Make sure you upgrade the software and get back to us with the performance. The latest software makes a lot of track improvements.

Very unusual considering I downloaded Lighthouse v16.47 earlier this week and installed it into the E127. When it finished, it prompted me to update any other connected devices, and showed a few EV1 components and the networked A7 (used only as a screen for the sounder) as being not up to date. I selected all components and updated them. Then I did a factory reset, redid the dockside setup and then the following day we did the seatrial for compass calibration (4 degrees deviation) and started our route after which led to the same findings as he had prior to these updates. I will go to the boat later today to reconfirm and record all installed software versions while also redoing the entire update routine on all connected devices just to be thorough.

[Steve - Raymarine - Moderator]

If that is the case, make sure Calibration Lock is Set to OFF, if it is set to ON it could lock you out of the Speed Input option.