Thread Tools
This thread is privately moderated by Jack Crossfire, who may elect to delete unwanted replies.
Dec 24, 2007, 04:58 AM
Registered User
Jack Crossfire's Avatar
Thread OP
Discussion

GPS lighting round


Well, if U plot acceleration vs. attitude U don't get any correlation. The secret is still locked up in the neural network.

After more test flights in cyclic -> attitude mode, it looks like 4Hz without DGPS doesn't buy much. Attitude hold is also sensitive to wind. If 4Hz doesn't come through, we're dropping a few grams and going back to the EM406.

Cyclic -> attitude mode with hard coded angles is so stable it's tempting to just live on that. Can fly through trees in ways no IR stabilizer ever dreamed of.

The search for GPS noise continues. Put the antenna out from under the blades to measure blade interference. Put her on the ground and cycled the throttle from 0 to light on the skids to measure vibration effects. Got no obvious interference.

One thing is 4 sure. There are no blogs discussing DGPS experiences. Maybe Web 3.0. Have 1 more scenario with 4Hz before it's time to think about DGPS.

The latest batteries are now down to 13min of flying. The first batch was retired when it hit 8 minutes of flying. https://www.rcgroups.com/forums/atta...mentid=1389849 As recently as https://www.rcgroups.com/forums/showthread.php?t=750660 the current batch was doing 20 min.
Sign up now
to remove ads between posts
Dec 24, 2007, 12:17 PM
Registered User

gps config


Jack,

Have you tried playing with the gps "Dynamic Platform Model" setting on the uBlox U-Center application? I am not sure from memory if you can change this via software on the NEO-4 range.

There's a few settings - Automotive (default I think), Airborne 1G and Airborne 2G that would seem to apply.

On the TIM-4H you can increase the NAV frequency to 5htz without issues. You'll likely need to customize (aka turn off) everything else you're not using.

Also the UBOX-Binary protocol is quite good (over NMEA).

James
Dec 24, 2007, 12:35 PM
Registered User

GPS Settings...


In experimenting with the Garmin GPS-18-5Hz tuning the dynamic settings seems to have a big effect.

>Cyclic -> attitude mode with hard coded angles is so stable it's tempting to >just live on that. Can fly through trees in ways no IR stabilizer ever dreamed of.

Are you talking about attitude mode only using the gyros?
Do you do any zero drift correction?
Dec 25, 2007, 07:03 AM
Registered User
Jack Crossfire's Avatar
Thread OP
Cyclic -> attitude mode is a mode where the cyclic controls roll & pitch angles instead of aeleron & elevator. A standard scenario for autopilot testing.


Quick Reply
Message:
Thread Tools