Beta Testers requested to fix Compass Issue

[sar104]

2ND TEST FLIGHT INFORMATION

Location: New Mexico
Declination: + 8.5˚
Elevation: 7500 ft
Winds: 0 - 5 mph W
Equipment: P2, Lightbridge, 14SG, GoPro H3+
Gains: Default
Satellites: 7

As mentioned before, I did an advanced IMU, compass and sticks calibration after update. Previous firmware produced mild TBE but quite noticeable J-hook and a CL error of around - 2 x declination.

Below is a video link for one test flight yesterday. I apologize for the loss of visual on the P2, but I did not expect it to go out of the field of view that I selected. I've added some guide azimuth information added for reference, demonstrating a number of issues:

1. I used no throttle input except to take off and bring the P2 back to a reasonable height between passes - all the other altitude changes are uncommanded.
   
2. The P2 consistently yaws left by about one declination on takeoff, and goes further left on first pass.
   
3. First GPS pass is wildly off target - subsequent passes mostly improve, but a couple demonstrate substantial hook on both the forward and return legs. Note, for example, that the 3rd pass is much worse than the second.
   
4. Course lock is roughly 2 x declination in error.

http://vimeo.com/98063733

 

[RemE]

Unfortunately saying gains "Default" mean nothing as the shipped gains remain until one actively updates the firmware AND selects Defaults, and Presses Enter on their keyboard. So the numbers are needed.

 

[d4ddyo]

Update on Fix?

 

[ianwood]

Update on Fix?

Read the thread?

 

[d4ddyo]

Update on Fix?

Read the thread?

well hell...i didn't think i needed to read 2 pages of gains first.

 

[d4ddyo]

I'm reading ... close but no cigar and possibly barking up the wrong tree?

 

[John Shaw]

Per request/suggestion in this thread...
I have never updated my gains. (at least nothing I am aware of)
Stock P2V
I just checked and...

...............Pitch....Roll....Yaw....Vertical
Basic........120......120.....120....120
Attitude....200......200

I have never seen anything that motivated me to want to change them and I am happy with the current response.

Have you ever updated the firmware? Which version you have now?

I'm testing the Beta 3.05
I have some earlier entries in the thread with my test reports.

 

[xtonex]

http://wiki.dji.com/en/index.php/Naza-M_Autopilot_Setting

Good explanation of gains

 

[Xrover]

2nd day of testing Beta 3.05
06/12/2014 Apollo Field Van Nuys California. +12 degrees Declination. Elevation: 800' Above Sea Level.
Weather 85 degrees F. Winds 10-20 mph.
All tests were done in GPS Mode

My first flight was using the Default 3.05 Gains.
125 125 120 140
260 260

After doing a Compass Cal. I turned off then on the battery with the P2 on the ground. I waited for complete GPS/Home Lock and 10 Sats.
I noticed that the (H) Altitude reading on the OSD showed 5M. It should be 0 (First Issue)
I restarted the battery and waited again. This time the H reading was 0.
I lifted off into a hover about 7 meters up. I did a 360 degree Yaw. P2 circled around the Yaw as stated many times in previous posts above.
Altitude Held OK.
I flew for about 3 minutes at an altitude (Shown as H on OSD) of 8M. The P2 pretty closely maintained Altitude within a meter or so.
I came back and hovered at what I figured was 2 Meters above ground. The OSD showed 8M (Totally incorrect)
I climbed what I guessed was another 1.5 Meters but the OSD still showed 8M.
Twice I was in a hover and the P2 would descend on it's own about 2 Meters but the OSD H reading remained the same.
I then landed and the OSD showed 5M. Should have been 0.

2nd Flight. I raised the Yaw Gain to 160%
On start up I had the same issue as above. H showed 2M. (Should be 0M)
I did another Off/On cycle of the battery. I waited for all locks. This time H was reading 0M.
I flew around for about 10 minutes and checked ability to maintain a straight course. It was about 10% better.
I performed some stationary 180 and 360 degree Yaws. It was about 15% tighter in it's ability to stay on axis. Nowhere near perfect though.
I landed and the OSD H reading was 5M.
Are you guy's starting to see a pattern here with the GPS knowing what it's Altitude is? No wonder it can't hold Altitude

3rd. Flight I raised the Yaw Gain to 175% I'll spare you the details but the Yaw was real twitchy and TBE's pretty bad on a 360 degree rotation.
The same issues occurred at Power up. H showed 2M. After restart, H showed 0M. After the short flight with unstable Yaw Gain at 175%, the OSD H reading was at 3M (Should be 0)

4th Flight i went back to Yaw Gain of 160% and boosted Altitude Gain to 160%
Same Start up issues as prior. OSD showed H 2M with P2 motionless on the ground. After restart, H showed 0M
I flew back and forth, side to side, all different combos at different speeds and heights including Yaws. Visually and on the OSD, Altitude loss was minimal and much less then prior flights. I am Happy with Altitude Gain at 160% (For now)
Upon Landing, H showed 6M. Should have been 0M.

Besides the Yaw instability issues, I am really concerned about the GPS and it's inability to determine it's Altitude. This would explain Altitude fluctuations when flying Beta 3.05

 

[RemE]

All of the Phantoms I've flown have various altitude "bias", both positive and negative numbers I've had at startup. Altitude hold doesn't use this number, it uses an internal precision barometer to maintain altitude, GPS values are not fine enough for this. This is not related or exclusive to 3.05.

It also uses the barometer to detect that it has landed, no more descent detected, idle down.

 

[wkf94025]

http://wiki.dji.com/en/index.php/Naza-M_Autopilot_Setting

Good explanation of gains

Fun and helpful read. Any idea what is meant by this in the Tips section?

"If you are a fresh player..."

 

[RemE]

http://wiki.dji.com/en/index.php/Naza-M_Autopilot_Setting

Good explanation of gains

Fun and helpful read. Any idea what is meant by this in the Tips section?

"If you are a fresh player..."

Setting up a new model with unknown performance... Getting a baseline going.

 

[N017RW]

http://wiki.dji.com/en/index.php/Naza-M_Autopilot_Setting

Good explanation of gains

Fun and helpful read. Any idea what is meant by this in the Tips section?

"If you are a fresh player..."

If you gotta ask...

 

[Xrover]

All of the Phantoms I've flown have various altitude "bias", both positive and negative numbers I've had at startup. Altitude hold doesn't use this number, it uses an internal precision barometer to maintain altitude, GPS values are not fine enough for this. This is not related or exclusive to 3.05.

It also uses the barometer to detect that it has landed, no more descent detected, idle down.

So the Altitude info displayed on the OSD is give or take 15' roughly?
I have had every firmware installed on my P2 in the order that they were released. I have relied on the OSD to give me pertinent info like Climb or Descent Rates and Altitudes. So far they have been pretty accurate and i have flown very low and fast at times with a spotter and using the Verticle and Altitude info on the OSD as my reference. So far, previous Firmware versions have been reliable in this situation.

This reliability has changed with 3.05

 

[N017RW]

All of the Phantoms I've flown have various altitude "bias", both positive and negative numbers I've had at startup. Altitude hold doesn't use this number, it uses an internal precision barometer to maintain altitude, GPS values are not fine enough for this. This is not related or exclusive to 3.05.

It also uses the barometer to detect that it has landed, no more descent detected, idle down.

So the Altitude info displayed on the OSD is give or take 15' roughly?
I have had every firmware installed on my P2 in the order that they were released. I have relied on the OSD to give me pertinent info like Climb or Descent Rates and Altitudes. So far they have been pretty accurate and i have flown very low and fast at times with a spotter and using the Verticle and Altitude info on the OSD as my reference. So far, previous Firmware versions have been reliable in this situation.

This reliability has changed with 3.05

On any given flight it is accurate for that given flight, and though I'm not positive, the a/c associates take-off altitude as Zero or ground level.

However being based on pressure altitude, with no means for compensation or adjustment to the barometer, and using the same take-off location, as the ambient pressure changes so does the measured altitude of that t/o location.

 

[RemE]

All of the Phantoms I've flown have various altitude "bias", both positive and negative numbers I've had at startup. Altitude hold doesn't use this number, it uses an internal precision barometer to maintain altitude, GPS values are not fine enough for this. This is not related or exclusive to 3.05.

It also uses the barometer to detect that it has landed, no more descent detected, idle down.

So the Altitude info displayed on the OSD is give or take 15' roughly?
I have had every firmware installed on my P2 in the order that they were released. I have relied on the OSD to give me pertinent info like Climb or Descent Rates and Altitudes. So far they have been pretty accurate and i have flown very low and fast at times with a spotter and using the Verticle and Altitude info on the OSD as my reference. So far, previous Firmware versions have been reliable in this situation.

This reliability has changed with 3.05

I have a 1st release Vision, P2Z, and now a Vision+, each on all released revs since their release. All have +/- 15ft alt when powering up, this is not a new issue.

 

[Zinnware]

So the Altitude info displayed on the OSD is give or take 15' roughly?
I have had every firmware installed on my P2 in the order that they were released. I have relied on the OSD to give me pertinent info like Climb or Descent Rates and Altitudes. So far they have been pretty accurate and i have flown very low and fast at times with a spotter and using the Verticle and Altitude info on the OSD as my reference. So far, previous Firmware versions have been reliable in this situation.

This reliability has changed with 3.05

Can you provide specifics on your assessment of the changed reliability in 3.05? What do you believe the range to be in this version?

 

[riblit]

Back to the matter at hand, I'd like to know who else is seeing un-commanded yaw. Sar104 is seeing it. I am seeing it.

Yes, I'm also seeing the uncommanded yaw, and also have the same site issues as the others trying to log in or change pages in a thread.

 

[Xrover]

Prior to 3.05, I don't ever recall seeing my OSD reading anything over 1M Altitude on startup. It has always bounced between 0 and 1M. There is no reason for it not to read that. The iosd mini displays your current height above the ground (After it get's HL)

I also don't ever recall it reading anything over 2M after landing. It has also in the past constantly updated itself as I am ascending or descending. What I am now seeing with 3.05 is that I can visually see the Phantom (non Vision) Ascend or Descend by itself or with stick input, change Altitude by more then 3 Meters and the iosd mini H reading will remain unchanged.

These are my observations with my P2 (non vision) and 3.05 Beta.
If you operate something long enough then you notice slight changes in it's behavior.

I'm not the only Beta Tester to comment on the Altitude fluctuations with 3.05B
Today i paid more attention to what the iosd mini was telling me and what was actually occurring.

 

[riblit]

This annotated file is the results of a first flight with new battery. There is some instability on takeoff due to the uncommanded yaw. I'll set up another camera to capture the takeoff and climb to hover.
The "J" hooks are much reduced, the second one is almost negligible. Declination here is +12' 22"