Guided Mode - Reduce Cruise Speed below 1m/s

Hi All,

We are actually working on getting the BR2 ready for a seabed survey using mission plan and guided mode (using a A55 DVL and Seatrac USBL)

However, we are facing a little difficulty as the minimum cruise speed we can set in QGC is 1m/s and it is way to quick for us.


Idealy we would like to set it at 0.1m/s, is anybody managed to change that minimum in anyway?
I was wonderring to change the thruster gain to a very low value, do you think it will do the job?

Thanks for your answer, hope it may help somebody else also!


I believe that the WPNAV_SPEED parameter governs the horizontal speed. You can see the WPNAV params in the ArduCopter docs, AFAIK they are the same for ArduSub: Complete Parameter List — Copter documentation

I am very curious to see what EK3 parameters you are using to fuse the DVL and USBL data!


1 Like


You are using a seatrac USBL?
Have you got the lat/long coordinates to show in QGC overlay? If so, how did you do it?

Hi Jørgen,

We do have a Seatrac, however we are just starting integration so we are still working on interfacing it on QGC.
As soon as we manage to have it, I’ll let you know, because it is not looking straight forward…

Hi Clyde,

Thanks a lot for your answer, I’ll have a look at it but it seems pretty much to the purpose.

We will make some testing on which of the DVL or USBL will be set as priority. My hope is to use the USBL to avoid DVL drifting, easy to say!


Hi Mathurin,
Me and my team are also working with BR2 and we also want to use GUIDED mode (using A55 DVL). However, we are having a problem that when we set mode to GUIDED the BR starts turning between left and right (0-180). We are using Ardusub 4.1.2-stable, have you encountered similar problem? :slight_smile:

Hi Lisa,
Our is not having this behaviour. Is you compass calibration ok?

There are a lot of compass disturbances in the area we would like to use the ROV so we have turned off compass and used dvl (external) as yaw source instead.

I am guessing that Samuel had more or less the same issue as you on this post:

Have a look to it!

Any luck on the USBL overlay by any chance?

Hi Jørgen,

I have set an answer in appropriate topic, please follow the link bellow:

Hope it helps you!