how precise should IRS/optical flow hold the Breeze in place when hovering?

[robbie2]

I have recently been testing my Breeze indoors and outdoors without GPS. I believed that the IRS and/or the ground camera would then hold the Breeze in place when no control inputs occur. As it turned out, my Breeze would however drift somewhat even indoors (both over short carpet and matte hardwood) and required manual inputs for not hitting my shelves. Altitude control both outside and inside was also not perfect, but so-so. Another flight yesterday was outdoors but with GPS on (12 to 14 SATs). When in low altitude over short, dry grass, the Breeze was again drifting, but rock solid after rising higher than say 10 ft.

How precise should position hold through IRS be, how good is it with your Breezes?

Thanks!

 

[DoomMeister]

I have had very little trouble with the Breeze outdoors with GPS on. I have flown it very little outdoors with GPS off, and find that IPS is rather ineffective in wind and the controller helps flying in those conditions.

Flying indoors one time was enough for me. The laminate flooring and 8 foot ceilings are not a good mix for the IPS. The altitude hold for hover is the height it will try to maintain over any furniture in the room also. I think a lot of the indoor drift can be attributed to prop wash in low altitude flight.

Yuneec has not released any real specifications about the Breeze’s IPS and its accuracy. Instead they publish their CYA in the user guide:

 

[robbie2]

Thanks for the reply, Doommeister!
For once, I had read the whole quick start guide again before posting, and I think it contains good advice. However, they could indeed be even more helpful if they revealed the specs of the system. I believe to understand that the infrared sensors are for altitude hold only (thus the problems with reflective or absorbing surfaces), and the cam is doing some pattern recognition (thus the hint to be careful with repetitive patterns). What we do not know is some of the important details that would allow us to come to better judgements of specific situations for ourselves:
- what is the field of view of the IPS camera? (I had an event where I flew the Breeze slowly forward over a small spot of a regular pattern (1m/3ft over a metal grid on my door step with 1 to 2 cm holes - but the whole grid is only 30 * 70 cm/ 1 * 2.5 ft), and it went immediately crazy, pushed to the left, and crashed into a nearby wall without any chance for me to react.)
- up to what altitude would infrared altitude hold work under optimal conditions? If the IR sensors fail, is there barometric altitude hold to take over?
- is it really so that using GPS totally overrides IRS? Personally, I have the impression both from reading this forum and from using the Breeze that below a certain altitude, IRS is given priority over GPS even with GPS enabled. But what is that altitude threshold?

I might actually ask (German) Yuneec support about all that, after now having an account in their ticket system anyways for the controller connection problems I keep having . Even if they can't always help, they are certainly responsive.

 

[DoomMeister]

I flew the Breeze slowly forward over a small spot of a regular pattern (1m/3ft over a metal grid on my door step with 1 to 2 cm holes - but the whole grid is only 30 * 70 cm/ 1 * 2.5 ft), and it went immediately crazy, pushed to the left, and crashed into a nearby wall without any chance for me to react.)

That was most likely a magnetic compass event.

 

[robbie2]

but GPS was off at that time?!

 

[DoomMeister]

The compass still feeds orientation to the flight controller.

 

[robbie2]

Thanks, I didn't know that. I am so much used to flying quads without any automatic orientation assistance that all that autonomy of the drone in deciding its whereabouts is sometimes annoying to me...