So I doubt this will make much sense or be a normal ask. But in most automated flight modes, like Loiter, if there is an attempt to drag the drone down mechanically, the drone will increase throttle to the vehicle’s limit. But I am running an experiment where I want to mechanically drag the vehicle down to a new altitude or mechanically land it without the drone fighting back, but still holding position. Don’t suppose there is a parameter that tells the software to relax its attempt to hold altitude while maintaining position?
So you want the drone to hold lat/lon position and not altitude? May need to do some lua scripting or firmware changes I imagine.
The wiki says:
The pilot can control the copter’s position with the control sticks.
Horizontal location can be adjusted with the Roll and Pitch control sticks with the default maximum horizontal speed being 5m/s (see Tuning section below on how to adjust this). When the pilot releases the sticks the copter will slow to a stop.
Altitude can be controlled with the Throttle control stick just as in AltHold mode
The heading can be set with the Yaw control stick
I believe the problem is that when the stick is released, it seems to maintain the current altitude.
If the stick is in the dead band that’s what it will do in any mode that uses the Altitude Hold Controller.
No. You would have to create a new Flight Mode. Use your favorite AI Coder and get to prompting.
Adding a New Flight Mode
Yes, if the stick is released, it holds altitude. But if stick is pressed altitude is changed in that direction the stick is pressed and with a speed proportional to the sticks deflection. So by this you can change altitude also in Loiter Mode.
Maybe I don’t understand why you want to change altitude mechanically.
What might work is limiting max throttle output such that a modified loiter mode could saturate against an upper bound that isn’t screaming at full power but still has enough headroom for attitude control. You’d probably also want to reset desired altitude on a somewhat frequent period to keep things from winding up out of control.
You may also be able to simply use guided mode and continually reset the desired altitude to present altitude if it’s lower than the last sampled one while keeping the lateral position static. I don’t know how much havoc that might wreak on the control loop(s).
There may well be a better way, but following a physical tether to a landing isn’t exactly a trivial problem to solve.
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Yea, use Loiter and lower the vertical controller P&I gains to near 0 before tugging on the tether.
Or guided mode as you say but use a load cell for a tension feedback signal.
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This makes a lot of sense, though still non-trivial because the weight of the line would constantly decrease with the reel-in rate.
Yea, that could be quite complex. Quite a few parameters would need to be variable.
Ok, that make sence. But isn’t it better to rewind only the loose part of the tether on ground while the drone is commanded to lower altitude. I think this can be monitored by a load cell on ground without influence of the tether weight itself.