Planning path problems

[EliotBR (Eliot)]

@suitangxiaoyi

The action I want to accomplish is similar to an ROV following a predetermined trajectory after powering on, such as a circle, and does not require the involvement of a QGC.

A circle relative to what? Following a path in physical space requires live positioning estimates, or at minimum some form of positional error estimation.

1. If your path is defined by known GPS coordinates then it should be specifiable before launch as a mission.
2. If your path is defined relative to the launch location then
   • if you have a positioning system you should be able to programatically define a circle to follow when the vehicle starts, using either
     • pymavlink (or similar) running on the onboard computer (to send MAVLink mission commands, or an orbit command), or
     • a lua script running on the autopilot
   • if you have no positioning system, and are wanting to move relative to a known object in view of the camera then see the post I linked to in my previous comment

Note that ArduSub’s positional control features are developmental, and many related features may currently be poorly documented (if at all), and the features that are implemented may be buggy. If you’re interested in something in particular I can try to find or ask about more detailed information on it, but much of the existing knowledge is in the general ArduPilot side, so for non sub-specific things it may be best to ask in the ArduPilot developer communication channels.

It may be worth looking at the ArduCopter Missions documentation. Not all of the information will be applicable, but it should hopefully at least provide an overview of the general missions structure and what kind of functionality may be available (in which case you can search for and/or ask about it in the context of ArduSub).

@Charles

Should I understand that if I have a GPS on my ardusub ROV, I should be able to do waypoint following in QGC without using arduboat, ardurov or else?

As I understand it,

1. All ArduPilot firmwares have access to the mission library
2. ArduSub has some positional control modes (see control_*.cpp) and commands implemented (including things like mission following and the circle control mode), but they haven’t been extensively validated on our end so we present them as developmental rather than stable and fully supported.

So basically, yes, you should be able to do waypoint following in QGC, but there may be unexpected issues or buggy behaviour that occur when trying to do so (in which case please report them and we can try to work together to fix them - as with any other issues).