ArduRover - In R/C boat - high frequency rudder cycling

Posted by Tony Holt on June 2, 2015 at 10:04am

Hi,

I have ArduRover v2.49 with Mission Planner 1.3.28 running with a 3DR Pixhawk with 3DR telemetry in a model boat.

I have now successfully completed a few missions albeit over small distances. While on the face of it, everything looks perfect, the boat continually wobbles (twitches) and telemetry logs indicate high frequency rudder cycling.

The telemetry replay for the 3 minute mission is on :

http://youtu.be/SgPZQHQajRg

It looks very successful  apart from the Ch1out values. This is the rudder.

The attached 'Rudder and ESC.jpg' shows mission output for both rudder and ESC (motor).
I had change to manual mode just before WP3 at about 10:46:40 to avoid a collision and that explains the ESC anomoly at that time. I realize I have to adjust (reduce) the desired cruise speed and that's not a problem. But the rudder activity is a concern.

The attached 'Rudder.jpg' shows a second by by second breakdown of rudder activity over a representative interval. This shows a 20 degree to port then a 20 degree to starboard almost every second. Hence the wobbles and twitches and probably why speed isn't rising.

I know this isn't a software or firmware issue - it's down to my own incompetence / unfamiliarity.

The final 'MP config.jpg' shows what is currently set. I'm sorry to be asking stupid questions, but is this  the right screen to start modifying the rudder behavior ? Does anything look obviously wrong ? Or do you have any other advice or suggestions ?.

Thanks in advance for any suggestions, help, advice or pointers.

Tony

Rudder and ESC.jpg

Rudder.jpg

Mission_Planner_Config.jpg

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Tags: ardurover, high frequency rudder cycling, mission planner, tuning
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Replies

    • Tony Holt > Grant Morphett June 3, 2015 at 5:31am

      Sorry Grant and Tommy for causing hassle. I didn't think of Dropbox - next time I'll be quicker out of the blocks. Apologies .....

    • Admin
      Thomas J Coyle III > Tony Holt June 3, 2015 at 3:33pm

      @Tony,

      Actually Google Drive is better as Dropbox forces you to join.

      Regards,

      TCIII AVD

    • Tony Holt > Thomas J Coyle III June 3, 2015 at 10:38pm

      Thanks for the info Tom and for your help yesterday. Google Drive is the one I'll use then. Appreciate the help - thank-you. Tony

    • Tommy Larsen > Tony Holt June 3, 2015 at 1:42am

      Tony, you can upload to my ftp server and then the file can be downloaded for the guys who want to check you logfile.

      Copy and paste into windows explorer:

      ftp://guest:guest@ijustwant.dyndns-at-home.com

    • Developer
      Grant Morphett > Tommy Larsen June 3, 2015 at 4:30am

      @Tommy I can't access your FTP server.  Under Linux I tried Firefox, Chromium and the command line.  No joy.  I can ping your ip address but port 21 doesn't appear to be open.  Are you able to fix it?

      Thanks, Grant.

    • Tommy Larsen > Grant Morphett June 3, 2015 at 4:57am

      Grant, everything looks ok for me. Please try again. No SSL or TLS.

    • Developer
      Grant Morphett > Tommy Larsen June 3, 2015 at 5:13am

      Sorry Tommy - it was my firewall.  I have it on super paranoid mode and I was blocking outgoing FTP.  I am downloading the zip now.  Sorry for wasting your time.

      Thanks, Grant.

    • Tony Holt > Tommy Larsen June 3, 2015 at 1:58am

      Thanks Tom.

      Used Filezilla. Filename is 2015-05-31 10-28-25.log. The unzipped file may be bad - had a couple of timeouts, but the zipped file looks to have come through clean. Am now disconnected and out of Filezilla.

      Very many thanks for your help.

      Tony

  • David Boulanger June 2, 2015 at 10:33am

    Tony,  The first thing I would try is to increase your NAVL1_PERIOD.  It will be in your full parameter list.  I am using 2.47 still but the parameter may still be in 2.49.  I had the same problem until I raised it .

    Regards,

    David R. Boulanger

    • Tony Holt > David Boulanger June 2, 2015 at 11:02am

      Hi David and thanks for the prompt response. My NAVL1_PERIOD is currently set to 16 with NAVL1_DAMPING at 0.76. I thought these values were involved predominantly in turns, rather than on straight runs between WPs, but I will certainly try increasing as suggested and see what happens. Thanks again for the advice. Tony

This reply was deleted.