How to quickly activate a copter launched midflight from a carrier

ArduCopter
1

We’re experimenting with launching a quadcopter from a “carrier” UAV. Both are running Ardupilot on Pixhawk 2.4.8 FCs. Assume that both vehicles are powered, have GPS lock, and are ready to fly.

The quad (powered up but with the motors deactivated) starts off being carried on the belly of the carrier. Midflight the carrier mechanically (via servo) releases the quad into free fall. We want to have the quad transition from inactive to stabilized flight as quickly as possible. I.e. before it hits the ground.

The quad can be armed, but the motors should be off. To avoid a mid-air collision, the dropped quad shouldn’t start the motors until at least after it’s been released, and possibly a fraction of a second after. Once the quad is dropped can we just switch to loiter or stabilized flight? How will the various guidance software react to starting in freefall?

Does anyone have any advice or recommendations? Which combinations of flight modes or settings would allow the quad to start actively flying as quickly as possible? We can use the GCS or FC Lua scripts to coordinate the drop and quad start-up processes.

2

Sounds like an interesting project - perhaps this could help?
https://ardupilot.org/copter/docs/throw-mode.html

3

It’s been done. Watch the 1st video in this link.
Drone drop
And read some of his other posts.
The actual use case was to use the Motor unit to gain altitude and then drop it and glide unpowered. The Motor unit would RTL after being dropped.

4

Much thanks for the quick feedback.

I hadn’t seen the throw mode. That looks like what we should start with.

5

I have used it successfully throwing the craft off my deck configuring for drop. It works.