End of flight analysis

[Hughie]

I am fairly new to quadcopters and due to an ESC issue I have not even managed to run my battery flat (until today)

I was flying in GPS mode, compass was calibrated, and waiting for IOC lock and GPS lock/home point - all fine. I started with 3/4 battery and wanted to fly it around to run the battery down to see how long it would last for and to practise a bit of flying.

I checked after about 15 minutes and the battery was still showing 2/4 bars. I flew it for another 5 minutes or so and suddenly it shot upwards and started flashing red lights instead of green, and started making off in a very approximate direction of the home point (not convinced of this because if it had landed on that course it would have been 20 or 30 meters away).

It was not responding to RC inputs so I switch to ATTI and brought it down (at least I think it was me bringing it down).

When I got to it the battery was showing 1/4 bars.

Question: Was this GPS loss behaviour or low battery behaviour. If the latter, I really was not expecting it to do that.

 

[ianwood]

Auto RTH on low battery. It's a setting in the Phantom Assistant.

 

[Idbird]

Sounds like you have your bird set to go home on low battery.

 

[Hughie]

Thanks for replies.

Yes just checked - I have RTH checked.

Thank goodness for that. I thought it was random flyaway behaviour.

 

[Meta4]

You should learn how the Phantom acts in a RTH situation.
Try it sometime in a clear, open area.
Fly 100 feet away, up 50-100 feet and switch off the Tx and observe.
RTH is something you need to understand rather than wonder about.
You may also want to consider what would happen if there are trees etc between you and the Phantom when it is in RTH.
Resetting home point up above the level of obstacles is a good strategy to avoid problems with trees.

 

[Hughie]

You should learn how the Phantom acts in a RTH situation.
Try it sometime in a clear, open area.
Fly 100 feet away, up 50-100 feet and switch off the Tx and observe.
RTH is something you need to understand rather than wonder about.
You may also want to consider what would happen if there are trees etc between you and the Phantom when it is in RTH.
Resetting home point up above the level of obstacles is a good strategy to avoid problems with trees.

Agreed. I need to do that to get a better feel for RTH. My problem is trusting it no to disappear or land somewhere unexpected

That episode did make me wonder about the Home Position registration.
"When" exactly is this done ?
I waited for rapid flashing green (IOC) then after the reds stopped flashing I got more rapid flashing greens (GPS and Home Position ?)

Shortly after that I took off. Flew up and forward. About 50m along that course was where the craft auto landed later. No where near where I thought the home position was.

Why would the home position be so far out, almost as if it had updated it just after take off ?

Any ideas?

 

[Meta4]

One way to be certain of home lock is to reset it after takeoff when you can clearly see the lights rather than on the ground where you can't see them clearly.

 

[Prylar Bek]

Really? How And and why to reset after take off?

 

[Prylar Bek]

Right for being on a boat. But I thought the last update had 'dynamic' HP reset no?

 

[Meta4]

Really? How And and why to reset after take off?

How ?? - by flicking S2 switch 5 times
Why? As above - so you can confirm the home point is set rather than assuming it has.
A major factor in "flyaways" is the pilot is uncertain if homepoint is set.
And also to set home point clear above any trees or other obstacles that could get in the way in RTH

 

[Meta4]

You could before last update fly it to where you wanted it and flick the S2 switch up and down 5 times and you would see the lights blink and that would reset the HP to where ever you did it but I believe that changed with the last update .

Still the same. The update added the option of a dynamic home point but no change to resetting HP anywhere you like.
I do it every flight.

 

[Prylar Bek]

OK, so you are basically re-confirming what you SHOULD have seen (green lights) before launch?

 

[Prylar Bek]

Yes, thanks

 

[Prylar Bek]

So I found the passage in the 'cheat sheet' summary. You flick that S2 oggle from THE MIDDLE position to the LOWER position five times! It says NOT to go from the top position to he bottom position. Just to clarify!

 

[Hughie]

Isnt toggle 1-2-1 of S2 for resetting Course Lock and 2-3-2 for Home Position ?

 

[Prylar Bek]

Yes as I read the cheat sheet

 

[Meta4]

Phantom vs NAZA 1-3-1 vs 2-3-2

 

[Hughie]

Thanks for clarifying.

 

[Great Pumpkin]

I waited for rapid flashing green (IOC) then after the reds stopped flashing I got more rapid flashing greens (GPS and Home Position ?)

Back to one of your original questions, Hughie.
Wait for the green LEDs to stop their rapid flashing and go to their slow, steady flashing. Then check to see how many satellites the Phantom is receiving. I won't fly with less than 8, although others do, perhaps to their peril. If all looks good (S1 and S2 in upper positions), then take off, but don't go very high or very far at first maybe 15' high and 20-30' out in front of you. Let hover. Its hover ought to be steady and it shouldn't go more than a few meters off point when you spin it 360 degrees. Be sure the Phantom is behaving nicely before you get rambunctious and fly far and wide.

 

[Hughie]

Thanks for your reply Great Pumpkin. I think I am going to have to get an fpv/iosd upgrade because I have no clue about satellite count except that it is >6.

Also, if I am in Naza mode with IOC set, shouldnt I see two sets of green flashing leds?

Thanks