Well, one of the shittiest and most destructive things that could happen to a UAV happened to me today. Accidental low-battery LAND failsafe set my 3DR Y6 down... into a pool. I retrieved it immediately and disconnected the battery. Now I'll wait for a few days for it to dry out before doing some system tests, but I'm curious what your expectations for system function will be at this point. Crappy? I think so. It was smoking when i pulled it from the water. Oy.
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Similar thing happened to me yesterday, 3DR IRIS+ practicing hovering and takeoffs/landing in my back yard, staying under 30' and using loiter mode and the wind kicked up 15+ knots and I decided to land and (foolishly) switched to RTL and the wind overpowered and blew it right over my pool. I switched to std and full throttle but response came too late and it just barely touched the pool with two feet and flipped then sank. The good news is the Ricoh WG-20 waterproof camera got a good show of the smoke bubbles for about a minute before I fished it from 7' down and pulled the battery. It's now disassembled and sitting in the sun during the day and under a fan at night. The only obvious damage is two rows of the 4-in-1 ESC shorted/fused and burned, but surely the Pixihawk isn't waterproof so its days are numbered.
I'm curious if any of your Y6 components were salvaged or did you have to scrap it?
Thanks
Thanks
By the way, I take full responsibility for the crash, and I'm grateful that the only damage that was done was to my UAV, and not to anyone else's person or property. It's a strong lesson to me, and hopefully to everyone else reading, that not knowing your device and it's settings inside and out puts people around you at risk. Learn from my mistake.
Be informed. Be thorough. Be patient. Be responsible.
Hi Ben, i'm not talking about responsibility, but knowledge of the vehicle and of the parameters.
I understand that many things can not be very intuitive, but a good starting point is read the wiki very well before you fly your own drone, whatever it is.
I've thousands flights with this system and I never went into the failsafe action for low battery, and always landed before it triggers.
The battery failsafe I see it as an emergency, not as an automatic on which to rely on.
Use a good LiPo and the tx timer set appropriately... good luck!
Cheers, Marco
These things can happen and unfortunately are unpleasant.
But we must also pay close attention to the timer on your tx, you did set correctly?
You should not rely solely on the battery failsafe, especially if it's no set to RTL, and flying above a pool with the battery failsafe set to LAND is not a very reasonable thing.
By relying on automatic failsafe and related thing you must first know them well.
If you're using now battery failsafe sets the value of not less than 10.5V for 3S Lipo, you need to consider that if the drone is far takes time to return to the home and land, and often this process can take minutes.
Imho the battery failsafe default must be "disabled", the users who must inquire about this feature and how to enable it and decide in what way, or the code should figure out how many LiPo cells you're using and set an appropriate voltage value for them.
My two cents...
Marco
In retrospect, I'm not entirely sure that the land failsafe had been triggered. Just a day before, I had checked the battery failsafe settings in APM Planner. The available range for critical voltage ranged from 0 to 66,000 something. I figured this was a bug, and manually entered a value of 9 into the settings.
Maybe 9V was too low, and i didn't have enough power to control the UAV? I don't recall what the amperage threshold I used was, but that may have been set too low also.
Ok, that's another big problem. Lets say that setting really is 9 volts. That is flatline dead. Way too late for a failsafe. If you are using a 3S battery, that is only 3 volts per cell (dead). It will fall out of sky long before you reach that point.
The failsafe voltage is properly presented in volts in the mission planner failsafe settings screen. Again assuming you're using a 3S battery, something more like 10.6 or 10.7 would be appropriate. For a 4S battery, more like 14.2. But you would be best served looking at your log files to see where the voltage is with about 3 minutes of flying time left. That way the failsafe has time to execute.
RTL: you might be under trees or there may be other rc aircraft in the area
Land: you might be over water or a person or a house
Instead just use a simple $5 lipo battery alarm set to alarm at 3.6v per cell.
Then if you get the alarm you can then switch to RTL,land, or manually land depending on
your situation.
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Amen.
Hi ben.
My IRIS as been under the water for more than 1hours a few days ago. I ve removed all the components and put them into a plastic box with rice.
After 48 hours i've re-mounted all the components (including 2 GPS , A sonar + a Gimball, ...)
And it works perfectly !
I've been flying hours, and did not encounter any issue.
This is a classic example of why users must have a detailed and clear picture of exactly how all of the failsafes work and what the implications are. Sadly, many people enable the failsafes and say "now I'm safe." Not understanding how and when they work can at best ruin your equipment, and at worst cause serious property damage or injury.
RTL is the safest battery failsafe action because you know it will be landing right where it took off. With the battery failsafe set for LAND, it might be landing in a pool, on a road, someone's roof, or a bystander's head. BUT, what if you are flying somewhere with overhanging tree branches? What if there are other RC aircraft in the sky around you. What if you are indoors? All of these things would be highly detrimental when the RTL tries to take it up to 150ft.
Do you know how much flying time you have after your battery failsafe voltage or MAH remaining kicks in? If you arbitrarily set it for something because "that's low battery", and there isn't enough juice left to fly home, you've made the situation even worse.
Have you tested your transmitter failsafes to make sure it acts as you expect? I've made that mistake and almost lost my aircraft.
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