Guided Mode - Reduce Cruise Speed below 1m/s

[m.jousse (Mathurin Jousse)]

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!

Mathurin

[clyde (Clyde McQueen)]

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!

Thanks,
/Clyde

[Jhans (Jørgen)]

Hi,

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?

[m.jousse (Mathurin Jousse)]

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…

[m.jousse (Mathurin Jousse)]

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!

Cheers,

[Lisa016]

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?

[m.jousse (Mathurin Jousse)]

@Lisa016

80). We are using Ardusub 4.1.2-stable, have you en

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

[Lisa016]

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.

[m.jousse (Mathurin Jousse)]

@Lisa016

are having a problem that when we set mode to GUIDED the BR starts turning between lef

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

Water Linked DVL A50, problems with guided mode

Hi! We have a BlueROV2 with a Water Linked DVL A50 that is behaving very strangely in guided mode. For example: Experiment: We place a goal right in front of the ROV and put it in guided mode via QGroundControl. Result: Sometimes the ROV rotates a seemingly random (and often large ) number of degrees before moving straight in the “wrong direction”. In QGroundControl the ROV strafes a bit and reaches the goal. In reality the ROV moves straight after rotating, (without strafing) and ends up i…

Have a look to it!

[Jhans (Jørgen)]

Any luck on the USBL overlay by any chance?

[m.jousse (Mathurin Jousse)]

Hi Jørgen,

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

Blueprint subsea SeaTrac USBL integration (Python)

Hi All, Here is a little up on what we did to get Seatrac USBL ROV position onto QGC map. As we struggle a little bit thi might help as no coding needed. First, need to configure an NMEA output on Pinpoint: [image] Important is to set UDP adress to ROV IP (here 192.168.2.2) and UCP to 27000 The go to BlueOS interface to use the NMEA Injector. Set as follow: [image] Then start the tracking on PinPoint, and only then open QGC. Be carrefull opening QGC before starting the tracking does not…

Hope it helps you!