Altitude Craziness!

[admiralriker]

I've never really noticed any altitude issues...until today.

As the system booted and everything connected OK, I noticed my altitude rising with the drone on the ground, rotors not armed.

1 foot...2 feet....3 feet....5 feet....but the drone is just sitting there.

The moment I arm the rotors, the altitude drops to NEGATIVE 24 FEET. As I lift off from the ground, the drone starts acting in it's own, rising higher into the sky, while the altitude is coming to a 0 foot equilibrium.

What the heck is going on? I did a compass and accelerometer calibrate with zero effect.

 

[AH-1G]

What are your surroundings like?
Are you able to use the controls to stop the drone from going higher?
When was the last time you flew?
when was the last time you cleaned out your control sticks?

 

[admiralriker]

I flew about 2 hours ago.

I was in between my garage and neighbors garage, about 4 feet off the ground, just trying to discharge my batteries down

I was able to stop the drone, but I fought the sticks hard.

This is a Yuneec referb and everything is completely clean.

The drone would not sit still. It wanted to drift like it had GPS disabled. It had 14 satellites locked. The drone DID at one point, while on the ground, produce a GPS loss warning but then cleared.

 

[Mrgs1]

At 4 feet it's going to be a bit unstable, easy to be heavy on the sticks trying to compensate, in between garages may of blocked or messed with the GPS on the ST16, and the copter, not the ideal position to be in, better to be free of obstacles, get yourself a third party charger capable of storage function, and read the Comprehensive Yuneec manual on this forum.

 

[PatR]

Between buildings blocks clear satellite view. The system may “see” them but the signal and data is unreliable.

 

[FlushVision]

I flew about 2 hours ago.

I was in between my garage and neighbors garage, about 4 feet off the ground, just trying to discharge my batteries down

I was able to stop the drone, but I fought the sticks hard.

This is a Yuneec referb and everything is completely clean.

The drone would not sit still. It wanted to drift like it had GPS disabled. It had 14 satellites locked. The drone DID at one point, while on the ground, produce a GPS loss warning but then cleared.

hovering 4 ft off the ground you are gonna suffer from ground effects. That would account for your aircraft not staying still. no surprises there. You never have satellites 'locked'. Your aircraft may 'see' a number of satellites but they ain't locked...they can come and go at any time, even more so if you are flying between structures like your neighbors and your garage. This is known as GPS Mask (or 'shadow')

Nothing in your text above surprises me and is to be expected given your hover height and location with respect to structures.

 

[AH-1G]

Sometimes being close to buildings if not most of the time will cause drift. Rotor wash will cause hovering disruption also.

 

[Mrbrucedw]

Did you calibrate your Accelerometer?

 

[Eagle's Eye Video]

Did you calibrate your Accelerometer?

The OP stated that he did... the correct issue has been identified as the restricted area he was flying in... causing several factors simultaneously... blockage from clear view of GPS satellites, prop wash, perhaps a bit of TB that the H is sometimes susceptible to. It is in fact, the very first caution in the OEM Typhoon H manual, after the specifications.

OEM Yuneec Manual - Typhoon H / H Pro

 

[AeroJ]

The OP stated that he did... the correct issue has been identified as the restricted area he was flying in... causing several factors simultaneously...

I am less sure about that. My H does this behaviour exactly as OP describes in 2 out of 3 launches, always has done, and does it regardless of location, no matter how remote. And mine did it yesterday on the first flight of the day when I was in the center of an empty cricket ground with 18 sats registered. I am in the process of working out if it is related to the altitude gain on motor start issue, but suspect it is. I will report back after further tests and telemetry analysis.

What is clear is that if you do the get the altitude jump before you leave the ground, you can just power down motors and restart them - the next time they are started resets altitude to 0 and for me at least, it usually stays there, though sometimes I have to restart more than once before it sorts itself out.

But it does happen exactly as OP describes. You lift off with moderate throttle input, then stop that input at around 15 ft, and the H stops, then suddenly climbs to more like 40 or 50 ft and then waits there, after which there are usually no more issues. Could be disastrous if you ever lifted off indoors or under trees, so I'd say it was a phenomenon worth investigating.

It happens to me so often I have rather accepted it as just one of the little quirks about the flight characteristics of that machine, and since doing so I have been careful never to launch with anything overhead so it has never mattered. I'd be tempted to blame the barometer but if that was screwy wouldn't we see the problem every time, and not just <half the time ?

It's not the only weird little thing that sometimes happens and sometimes doesn't. Sometimes I get flights with the 'zzzzp problem' in which inputs suddenly become much more jerky than usual for a short time, producing unusual zipping sounds from the motors, and tiny little uncommanded rises. These don't affect flight control in any serious way, but I do wonder why one flight will exhibit this behaviour, and then it is entirely absent for the the next one !

 

[AeroJ]

Here's some video of mine doing it yesterday, in what I would describe as a pretty much perfect environment...

 

[AH-1G]

How old are these motors?

 

[AeroJ]

How old are these motors?

What, me ? Less than a year. This was flight 200 / 201 of my machine...

 

[AH-1G]

I heard the noise you mentioned, I can only think of it being motor related? You may have a bad motor or motors and the H is trying to compensate for it?

 

[AeroJ]

That's interesting; I do have one motor that seems to have ever so slightly more play in it than the others...
But then I remember all the launches this doesn't happen with, and the fact that once it has done its initial jump, and the odd zzzp sound soon after that, the problem stops for the rest of the 15 minute flight. If it was a motor problem, would it not be present all the time ?

 

[Mrgs1]

Here's some video of mine doing it yesterday, in what I would describe as a pretty much perfect environment...

Reminds me of a blue bottle fly, definitely needs closer inspection.

 

[Mrgs1]

I heard the noise you mentioned, I can only think of it being motor related? You may have a bad motor or motors and the H is trying to compensate for it?

Would this show up in Telemetry?

 

[AH-1G]

This may not happen all the time. Sometimes it's in that perfect state and others it's not. It may depend on temperature also.
Remember, contraction and expansion

 

[AeroJ]

It shows up in the altitude telemetry, but motor status telem remains unchanged for entire flights.

 

[AeroJ]

This may not happen all the time. Sometimes it's in that perfect state and others it's not. It may depend on temperature also.
Remember, contraction and expansion

I'm not too worried by it to be honest. I still get pretty flawless flight control, whether it's a zippy type flight or not !