9 replies to this topic

[Terry]

Just an update to say I got my quad flying ok now after giving up for about a year. After a prod from Mr RC-CAM telling me that parameter adjustment are possable via USB on the later models I thought I would try connecting mine up to see if it would work and it dose!

I have an early FY-90Q basic not pro but after following the instructions here http://www.rcgroups....&postcount=1813 I found it will work just fine. All thats needed is to download the software from the FY website and connect a USB to TTL converter to the FY-90Q. The settings for me were all way too high causing the quad to swing about overcorrecting all the time, worst in a wind and at low throttle. After backing off the settings I have much more confidence in it and will now start testing with a camera on board

If anyone else like me found tuning the pots didnt do the trick then this may help.


Terry

[Mr.RC-Cam]

That is very cool. I wonder why they didn't advertise the PID tuning feature long ago.

[Terry]

I dont think they ever wanted to alow user access to the parameters apart from adjustment with the 3 pots but after customer pressure they decided to allow resticted access via a didicated program.
I use the USB to TTL onverter that came with my Remzibi OSD so didnt cost me anything to try


Terry

[Mr.RC-Cam]

I'm not sure if it was because they wanted to restrict access to the FY-90Q. Perhaps they didn't recognize the value of it.

Case in point. Back when the FY-20A was a new gadget I contacted them and asked if it supported PC access for firmware upgrades and tuning. From their bewildered response I gathered that they did not understand why anyone would need it. Fast forward a year later and the FY-20A still does not have this feature.Or maybe it secretly does.

[Terry]

Im still running out of stick after hovering for a while, even in a slight head wind more and more forward stick is needed to stay still. has anyone else had this problem?


Terry

[Kilrah]

It's common of many accelerometer-equipped quads where the stick controls attitude and not angular speed.
If you stay tilted for a long time fighting a steady wind (or simply flying forward for a long stretch), the (rather simple) algorithms that calculate the attitude presume that you're flat and the tilt information is sensor error, and start compensating for it.

Edited by Kilrah, 22 August 2011 - 01:30 PM.

[Terry]

Ahh thanks for that, I was a bit confused as I had not seen anyone else say about this. I guess an ASI would be needed to correct this but as I cant reprogram the FY adjusting the accelerometer to a low level will be the only way.


Terry

[Kilrah]

Personally for FPV (and also for video) I always prefer angular speed control (gyro-only, or heading-hold mode depending on how the particular quad controller calls it).
Attitude control is OK for photo as you don't care about doing smooth movements.

[Terry]

just thinking about it and my little Jump jet quad dose the same thing if you fly round in circles for too long and that has no accelerometers. The problem must be because the JJ uses your avarage stick position to set the quad level. I guess the FY uses the accelerometer but why dose the FY accelerometer adjust its quad level position during flight?

Using no self leveling as you say would sort the problem out but the other FY20 and such dont seem to get confused like this do they? unless this is linked to the intermittant diving problem I have had with the FY-21!


Terry

[Mr.RC-Cam]

Hopefully you find a way to reduce the problem. Assuming that your stabilizer is not defective, I suggest you concentrate on the pitch axis's I-term and see what effect it has on the issue. Then use that info to direct your PID choices.