Mitigate tipover on landing

ArduCopter Copter 4.5
1

We have had a couple problems recently where our copter has tipped over on landing. In the first case it was because the pilot landed in loiter mode, then tried a DJI style disarm. In the second case (loiter mode again), the pilot applied a fairly large roll input right at the moment of touchdown.

Rather than use the motor emergency stop, or switch to altitude hold, they chose to do nothing and decided the problem was mine to solve.

Is there anything that can be done to protect people from themselves in this case? Maybe reduce the disarm delay, or reset the position controller in the Landed_Ground_Idle case? We are running version 4.5.7, is there a way to extract the spool state from the logs? I see in version 4.7 there is the SPOL messages, but I don’t know if the equivalent info is in 4.5.7 logs somewhere.

I realize that this is user error, but the current expectation is that the user be able to dump a small box of parts packed tardis style into a mud puddle. From there, they simply think really hard while rubbing their temples, the drone assembles itself, flies the mission, and puts itself back in the tardis.

2

Improve user training. And practice with them.

Regarding configuring after assembly, use ArduPilot methodic configurator software.

It was developed for exacly this use case: guide users from a pile of lose components all the way to a correctly working vehicle.

3

This kind of thinking is backwards and dangerous. The expectation when operating any aircraft is that the operator is properly trained, familiar with its controls and contingency/emergency procedures, and is well prepared for flight.

4

I agree completely. Unfortunately, this is the expectation placed upon me with only a small amount of hyperbole.

In this case the systems is already built, tuned, integrated, and tested. It’s a ready to fly platform that we produce. This issue is an operational one, nothing to do with any particular piece of hardware.

I’ll be expected to provide some sort of solution here, but I REALLY don’t want to start marking hacky changes to the landing detection logic. This is a recipe for disaster.

If your stance is that competence is the correct solution, I agree, and will present this. If there is something easy that I am unaware of that can help mitigate this issue I would love to hear that as well.

5

Training and competence are the best solution

6

Position the copter over the landing area, or be flying it down in Loiter mode, and switch to Land mode. The copter will come straight down and disarm when landed.
Land mode is useful during testing too.

I also use these settings, which assist both landing and takeoff:

PILOT_THR_BHV,7
PILOT_TKOFF_ALT,250
WP_NAVALT_MIN,1.5

Check the throttle behaviour options.