Baro problem or PID? [semi-solved]

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Re: Baro problem or PID? [semi-solved]

Postby EX_TRUE » Fri Jul 03, 2015 2:59 pm

1. Is the UKF_ALTITUDE (UKF_PRES_ALT) of new version firmware equal to the altitude of old one ? :lol:

But I have tried the UKF_PRESS_ALT, the AQ6 also drop a lot when forward, which different to the old version firmware.

2. Why ALT_POS of alt_ukf(accel and baro) would drop, yet the old one donot have this issue.
EX_TRUE
 
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Re: Baro problem or PID? [semi-solved]

Postby jet » Fri Jul 03, 2015 4:10 pm

Hi, EX_TRUE,
I cannot answer your questions.
However, altitude drop seemed to be common for many flight controllers.

Based on APMCopter, "Momentary altitude loss of 1m ~ 2m when the copter levels out after a high speed forward flight. This is caused by an aerodynamic effect which leads to a momentary low pressure bubble forming on the top of the copter where the flight controller is mounted which leads the altitude hold controller to believe it is climbing so it responds by descending."

Wish this problem could be improved in the further firmwares :P .
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Re: Baro problem or PID? [semi-solved]

Postby chschmid » Fri Jul 03, 2015 9:23 pm

Gents

There is no alt drop if your system is tuned well.
See here

[youtube]watch?v=tHvbEYuvRs8[/youtube]

10m relative alt is the mission alt.

Cheers
Christof
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Re: Baro problem or PID? [semi-solved]

Postby jet » Sat Jul 04, 2015 9:25 am

Hi, Christof.
The video looks good.
Altitude hold mode may be similar to mission mode.
However, I did not try mission mode yet.
In this discussion, I tried to find out the problem causing altitude drop in altitude hold mode.
Based on some AQ6 users' experience (including me), altitude drop seemed to merely happen for "forward" flight.
So far, although I had tried all suggestions offered by AQ6 users, I still failed in overcoming the altitude drop in altitude hold mode with the latest firmware..><..
jet
 
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Re: Baro problem or PID? [semi-solved]

Postby chschmid » Sat Jul 04, 2015 6:16 pm

Hi Jet

What does your log say regarding altitude after a forward flight in PH? Maybe you can post a log here.
Whats your TH stick deadband?

Cheers
Christof
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