Parachute detachment

General
1

So i know mission planner can be used to autonomously deploy a parachute but can it be used to autonomously detach the parachute from the vehicle ?

2

A glance through the docs and parameters shows nothing that appears intended for that purpose.

I often recommend onboard Lua scripting to solve niche issues/use cases, and this once again seems a great candidate.

A commercial system with which I’m familiar looks for (at least) the following conditions to be met prior to an automatic mains chute detachment:

  • A certain amount of time elapsed under mains canopies
  • A momentary deceleration spike indicating ground impact (greater than that expected under chute)
  • Vertical velocity near zero for a number of milliseconds

The decel spike may be hard to detect through Lua. If you wanted to detect something so transient, you’d likely need to modify the source code itself (which might be a reasonable dev request).

Also, the documentation reads a bit confusing. The typical/industry/aviation term for initial parachute deployment is “deploy.” The typical term for severing its attachment is “release.” The docs seem to use “release” where “deploy” is intended.

1 Like
3

thank you very much and yes i was a bit confused when reading the docs since sometimes the word “release” was used so thank you for clearing that up

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4

Full disclosure, that was my first read through ArduPilot chute parameters and docs, so if I have misinterpreted anything, I hope someone more experienced chimes in with a correction.

5

also what if i wanted the parachute to be released at a specific altitude not when it hits the ground. What conditions would have to be met ?

6

That’s easier. You just need an accurate AGL altitude source (like a radar or LIDAR altimeter or reliable GPS delta-elevation). Release at desired altitude. It may also be wise to measure vertical velocity before release to make sure the chute has done its job.