Landing RTL drone flips over ( stupid mole hill, or grass) and will not turn off. This happened to me on a landing a few times. The device will flip over and continues running, I cannot shut it off. I use down to the left, no dice in any mode. It finally killed itself. Is there a way to program a death switch? The last time it ate up a pair of blades.
I have had this happen a few times, on 2 separate drones.
I think a "death" switch is a good idea. I had my IRIS fly almost out of sight it was so high (1,100+ feet) . Fortunately, I had pitch/roll/yaw so I could keep it overhead, but no throttle. After a 300' plummet to earth, my IRIS is now on its way back to 3DR.
Anyone out there know how to program a "kill"switch?
Yikes! Thats a bummer
In the RC Helicopter world this is called "Throttle Hold" and I really think this safety feature should be considered with the drones. I think the pixhawk has some sort of crash detection, but I've seen some crash videos where the motors run on for way too long after a crash. I've been meaning to look into this. Sorry about the crash.
This may not have saved you in this situation, but its come up in several other threads lately so i figure id say it again here. I like to land in Stab mode because it gives you a more direct control over the spinning of and disarming of the props. It lets you disarm quicker as its not checking to see if its landed, as well as it wont fight to remain level which will also delay disarm if your landing area is not level enough. Just this morning I was landing on the hood of my car because i didn't have a good place to land that wouldn't kick up a ton of dirt and sand into the motors/gibal/etc, and I stupidly tried to land in loiter. As it was touching down two of the feet were grounded, but because of the curve in my hood it remained powered up on the other two. A gust of wind hit the quad as it was doing its little floaty bouncy landing dance and knocked it off my hood and upside down into the sand below. I spent the rest of the afternoon disassembling and cleaning out the motors thinking about my mistake. I like landing in stab mode because it allows you to plop the quad down the last few inches and wind down the motors immediately.
It does have crash detection but it is way to slow. I suspect this is to allow recovery if it hits a tree as an example. But once the Altitiude is under a certain threshold it should turn off much faster.
Yup, what SkyRover said. When I use the "land" switch, I'm in Stab mode, I usually forget to pull the throttle down until it's on the ground, but have never had a problem with it flipping. I think some people may try to disarm too soon, which results in a full left yaw, which will make the quad do all kinds of funky things. As far as the "crash detection", I accidentally flipped into "auto" one day, while under the tree canopy of my 1 acre forest. I assume because I didn't have any flight plan loaded, that the Iris+ went into RTL, and was trying to go to it's pre-set altitude, before landing, as it suddenly started climbing, and the throttle did nothing! I watched it bounce off of 2 tree branches, before I realized what I had done. Funny, after striking a tree, it would bounce off, right itself, and continue to climb, bouncing, and righting itself, each time. When I realized I was in "auto" and switched back to Stab, I had the throttle pulled all the way back, so of course, she came back down rather quickly. Only damage was a slightly nicked prop. Yes, the Iris+ was smarter than I was!
A switch to stop the motors seems to me to be a no brainer. I had a RTL that cost four blades possibly due to a last minute gps adjustment. In RTL, I didn't have control of the throttle. In my first prop replacement incident, I let the iris+ land itself and the land detect feature was to slow, it tripped on a pebble and flipped. Props did not stop spinning till all were damaged or broken. In my attempt to put a kill switch in, I tried the MOT_SPIN_ARMED to 0. This caused the motors (three of them) to start spinning at about 40% throttle on the next flight attempt. I didn't want to risk even more broken props, so the iris+ is now grounded.
With more than 400 parameters, I realized I was way over my head trying to customize the settings. So I'm learning how to tweak CC3D, Naze 32, and the KK2.1 boards on some 250 quads. Maybe after a little more learning and tweaking, I might be ready to tackle the Pixhawk and Mission Planner again.
I know this isn't a real answer to your question, but if I'm not sure about the landing (dirt, level, etc.) I have taken to just catching it. Many props saved. lol
Maybe this is the answer! Turn the legs into handles....
I'm using APM 2.6, all my missions end with RTL.
6 feet or so, I pull the throttle all the way down.
At this point, APM controls throttle, and at the moment of touching, I flick to STAB mode.
Hasn't failed me yet......
It helps to come from a "real rc heli" world :-)
@Tim there is no need to tweak anymore autotune is like magic (if you remember back in the day) If there was a kill switch users would trigger it by mistake and then complain that there is a kill switch. If the quad is moving on rough terrain it will dig a skid in. Just like a real helicopter look for dynamic roll over (well not quite the same but similar)
Only fly where there are suitable large clear flat areas until you are more handy flying manually.