Tethered drone cable slack

Hello, I am building a tethered drone, and I want to make sure it always keeps cable tension by having more throttle than needed to keep its altitude, and the cable will hold it in place with no cable slack. I also need it to keep its position over a certain point (using Novatel ALIGN for that), but I haven’t been able to find a flight mode to fit my needs, do I need to create a new flight mode for this?

1 Like

Why not do it on the tether ground side??? That how all the other tether units do it.


It needs to work on both sides, because the aerial unit has to have more throttle than needed to keep it level, and the ground unit will be the one to determine the current height with a winch, which is why I need to find a good flight mode or way to make the aerial unit support the base unit to eliminate cable slack.

I think your approach is too complex. You need a force meter at the winch side and keep a (small) constant pulling force to keep the cable straight. At least all tethers I worked with were worked like this.

I do have all of that, but my question is different, how do I make the drone itself always have a certain throttle, and not “try to keep level”

I think that contraindicates the capability to keep altitude.
(Stabilize mode has a constant throttle, but cannot keep altitude)

and can I give Stabilize mode commands via companion computer to change its throttle?

With RC passthrough surely, but you also have to do your own position holding as well.

If I need to do my own position holding, and since I already have to implement Novatel ALIGN into the code, maybe I should just create my own flight mode then?

My guess is yes, based on the stabilize mode. Anything else will include the altitude control, hence no direct throttle control.