We have a Blue Robotics ROV2 with highly accurate positioning system and camera installed. For context, we use this for taking imagery of the seabed by positioning the ROV 1m above the seabed as it follows an automated flight path with the final product being an geotagged photomosaic.
In QGround Control, when using Manual flight mode the ROV holds the depth lock. When getting the ROV to follow a pre-planned flight path using Auto mode, the depth lock does not hold. Every 1-2mins, withing a spacing of less than 10m travelled, the depth will change by 1m (e.g. from 5.5m to 4.5m) meaning the mission must be stopped, ROV adjusted to desired depth and then continue missions by which point the ROV has drifted slightly from desired path. As the depth hold is locked in Manual mode, I am hoping my logic that the depth hold issue on Auto mode is a setting or tuning fix within QGround Control rather than the ROV or positioning itself. I am still learning all that QGround Control can do in terms of editability and settings so this may be something in the way I am setting up the flight plan. Thank you in advance for any responses.
Manual mode does not control depth! Perhaps you mean you are in depth hold mode, or surface track? If using QGC, you’re probably not using the latest modes - is there a reason you haven’t tried Cockpit?
QGround Control is just a ground control station software, it isn’t flying the ROV as much as telling the autopilot what to do!
Auto mode does not support surftrack - but work is being done to bring terrain following to auto mode. In the meantime, if your vehicle has altitude via a DVL or Ping single beam sonar (or other altimeter), the autopilot can use that for SurfTrack mode.
I’m curious what kind of camera you’re using, and what “highly accurate positioning system” as well!
Thank you for your quick response. Apologies, I meant that when operating the Blue ROV2 using Depth Hold, the depth holds at the specified depth but when it is switched to Auto mode, the depth does not hold. I am able to create a pre-planned mission and get the ROV to follow it in Auto mode but the depth does not hold which I would like to solve as the photos taken are not taken at a consistent depth otherwise. Is this possible?
I am not sure that Cockpit works with our attached technology but I will double check. In the meantime, is there a way to solve this using QGC?
Thank you so much for taking time to consider my query.
What version of ArduSub are you running on your vehicle?
Auto mode navigates between waypoints that each have a coordinate, which includes depth. By “depth does not hold” do you mean a different (constant) depth is maintained during the auto mission than is desired, or the vehicle navigates while at the surface? If you’d like the altitude to remain consistent, in terms of the distance between the vehicle and the bottom, work is underway to accomplish this but currently only SurfTrack mode provides this ability, with navigation needing to be done by the user.
It is a bit tricky to enter SurfTrack mode in QGC, but I believe it is possible. Any vehicle that works with QGC should work with Cockpit - install it and give it a try!
I am not sure on the version as I do not have the ROV PC with me. What I mean is that between each waypoint the depth is not consistent and the ROV drifts toward the surface. I want it to be able to keep a constant depth / altitude whilst it is operating in Auto mode.
From some research, there seems to be a work around by setting the waypoint altitude as minus which provides distance from surface / depth e.g., -4m. I can see this is possible to do for individual way points but I want to bulk set all way points at the same depth when I have many. Do you know if this would work (keep the ROV at constant depth/ altitude between waypoints) and how to bulk set altitude depth?
We really need to know your ArdSub version - are you running the latest stable? There may have been similar issues to your own in the past with older versions….
If using QGC, you should definitely be able to specify the depth of a waypoint, with subsequent created waypoints using the same depth.
I will check the Ardusub version next time I am with the ROV. We found a work around. Create Pattern > Survey > Basic, then upload and download from vehicle. The downloaded plan converts the survey pattern into waypoints. Then every waypoint must be edited to a minus value based on distance from the surface.
Do you know why ArduSub - a programme designed for operation vehicles under water does not allow you to put a minus value for a survey pattern? Is this a software that is still being developed?
I am also having issue with adding other parameters to the instrument panel on QGC with ArduSub, there is no settings cog or drop down which would allow me to add additional things to the panel such as distance travelled and altitude etc. Is this possible with QGC and ArduSub or is ArduSub a refined version on QGC so this option is not available?
Do you know where we might find an expert on QGC - this programme seems to be the limiter currently in our processes and we would like to maximise efficiencies.
ArduSub is an autopilot firmware - the QGC ground control station software is primarily used with aerial drones! ArduSub definitely supports depth values for waypoints. Blue Robotics does not develop QGround Control, and due to frustrations with customizing it has been focused on developing Cockpit as an alternative for a couple years now. It is quite capable! The latest beta version, not yet released, will allow bulk ediiting of waypoints - whether used with ArduSub or other aerial firmwares like ArduCopter, ArduPlane, etc.
I’d recommend trying Cockpit - I have abandoned QGC in my own testing quite some time ago… until the new beta comes out, you’ll need to do the same external editing of the mission waypoint altitudes, or click through each waypoint’s altitude to adjust it. Sorry for the hassle!
