ggrif

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Revo Position Hold question
« on: July 18, 2015, 06:44:10 am »
Hello all, below is a post I left at OP a week or so ago, so far the only responses I've gotten are from two other folks reporting the same issue, nothing back from OP developers. (I guess you're all here now 😀)  Could someone help us out?



Can one of you experts take a look at the attached log file and give me a hint why my 460 woodie, Bruiser III, kicks backwards and to the right when PH is engaged the first time after I change a battery or disconnect/reconnect the battery?  This behavior only occurs once per battery/cold  boot.  Works fine after that.
 
I just updated Bruiser to 15.05, have not tried any other GPS flight modes yet, so no data for other modes.  Wanted to get PH dialed in first.
 
Frame:  homebuilt wooden 460
Motors: SunnySky 2216-1100
ESC:     dys 30A, One Shot
Props:  APC 10x4.7
GPS: OP V9 Platinum
Tx: Taranis 9x
 Rx  : D4R II, PPM
Batt: Glacier 3S 3300
 
Also, per the Wiki, I've attempted to complete the "VTOL SelfTuningStats" procedure but never see any data populate the table.  Does PH have to be rock solid to accomplish this?  Wiki says 6 seconds PH should be sufficient.
 
Finally, never had this issue with this frame on previous versions.  And yes, I erased and updated; plus I did an old school Rescue and update.  Same results.
 
Thanks as always!
 
Attached File  OP-2015-07-08_08-27-33.opl   291.87KB   2 downloads
 

f5soh

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Re: Revo Position Hold question
« Reply #1 on: July 18, 2015, 09:26:14 am »
Please post log file, most of us can't connect to OP forum anymore.

Thanks

dezent

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Re: Revo Position Hold question
« Reply #2 on: July 18, 2015, 10:38:33 am »
You should try VelocityRoam, this is a new flight mode that works much better than the old versions.

liftbag

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Re: Revo Position Hold question
« Reply #3 on: July 18, 2015, 02:11:25 pm »
I've always had the kick back on ph with old firmwares.
I still have to try the new GPS assisted flight modes of 15.05.

ggrif

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Re: Revo Position Hold question
« Reply #4 on: July 18, 2015, 04:25:16 pm »
Hmmm, seems like a known but unknown bug, starting to get some replys at OP from others with same issue. No help though, it seems everyone that might help has left the project or been banned.

I'll attach log in later post.

Thanks all!

Re: Revo Position Hold question
« Reply #5 on: July 26, 2015, 07:21:02 am »
I used to see that before 15.05 and then it went away for me.

Before the first flight of the day, make sure to leave the GPS powered up, out in the open for at least 15 minutes, so it can download the GPS almanac.  The rest of the day you can just wait more like 2 minutes after power up.

One other thing, after letting it sit still, powered up, for a long time, and flying without power down/up, it is good to rotate it in all 3 dimensions before arming or flying.  This straightens out the EKF if it has diverged due to sitting perfectly still for a long time.  I usually do a hand held 45 degree banked, coordinated 360 turn.

ArnhemAnt

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Re: Revo Position Hold question
« Reply #6 on: July 27, 2015, 11:50:34 am »

Before the first flight of the day, make sure to leave the GPS powered up, out in the open for at least 15 minutes, so it can download the GPS almanac.  The rest of the day you can just wait more like 2 minutes after power up.

One other thing, after letting it sit still, powered up, for a long time, and flying without power down/up, it is good to rotate it in all 3 dimensions before arming or flying.  This straightens out the EKF if it has diverged due to sitting perfectly still for a long time.  I usually do a hand held 45 degree banked, coordinated 360 turn.

Great tips dude. Without a doubt, leaving the GPS sit for at least 15 minutes sure makes a difference, particularly when you start playing with things like PH and you want a SOLID lock. I remember being part of the FTT and testing PH for the first time. My little test frame (330) was solid as a rock in 30kn winds. Sure impressed the hell outta me.
If you do what you need, you’re surviving. If you do what you want, you’re living.

MickD

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Re: Revo Position Hold question
« Reply #7 on: July 27, 2015, 02:16:05 pm »
Is there any info on the different flight modes available with GPS?  What they do or what is available? 

Re: Revo Position Hold question
« Reply #8 on: August 06, 2015, 04:37:14 am »
Having problems with my Nano while in Position Hold and other GPS modes. Installed the V9 and did a new setup wizard. I get a solid lock on GCS with 9-11 sats indoors and the craft looks like it is acting normal while connected to the GCS. When test flying hover and altitude hold work fine but Position Hold drifts in a ever growing circle and randomly banks. I also do not have any stick controls while in Position Hold? I also tried land and it did the same thing.

Here is my log.

f5soh

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Re: Revo Position Hold question
« Reply #9 on: August 06, 2015, 10:32:59 am »
You are using Comp+Mag+GPS : try INS13
For some reason i got only a few seconds with your log...

Edit : Keep in mind gcs still recording when board is disconnected, i just see some activity just now :D

I saw GPSAssist + PosHold : This do not make sense, if you are using GpsAssist, when you do not touch stick you are already in PosHold mode.

Add GpsAssist to a simple mode like Attitude, without Altitude Hold for example (stab3 in your case)



« Last Edit: August 06, 2015, 10:55:26 am by f5soh »

Re: Revo Position Hold question
« Reply #10 on: August 08, 2015, 12:00:38 am »
I think I read in some other thread that GPSAssist would add a more sophisticated breaking sequence if enabled for position hold. I.e. it would only make a difference if entering PosHold with speed. Have not tried it myself though.

Re: Revo Position Hold question
« Reply #11 on: August 08, 2015, 12:38:48 am »
You are using Comp+Mag+GPS : try INS13
For some reason i got only a few seconds with your log...

Edit : Keep in mind gcs still recording when board is disconnected, i just see some activity just now :D

I saw GPSAssist + PosHold : This do not make sense, if you are using GpsAssist, when you do not touch stick you are already in PosHold mode.

Add GpsAssist to a simple mode like Attitude, without Altitude Hold for example (stab3 in your case)

Yes I had the wrong settings. I changed it to INS13 and am going to try out GPS assist with simple modes.

I think I need to rebuild my quad to limit electromagnetic issues. I really did not think much about this when building it as it was never going to have GPS with a CC3D.

Thanks for the reply.

Re: Revo Position Hold question
« Reply #12 on: August 10, 2015, 09:26:27 pm »
"Toilet bowl" in GPS flight is usually caused by bad wiring (must neatly and tightly twist all high current wire sets) or by bad mag calibration.

I understand that mag calibration can really only be done with telemetry, that USB cable causes mag issues.  I have heard one person say that they were able to do a usable calibration with a USB cable though.

LP hasn't released yet (planned for September).

GPS modes require GCS -> Attitude -> Settings -> Attitude Estimation Algorithm = GPS Navigation (INS13)

The GPS mode you want to play with first is called VelocityRoam.  It is like PositionHold if you leave the sticks in the center, but it moves as expected when you move the sticks.  If you hold left bank stick, it moves left as long as you hold the stick.  Beware that the motors stop if you go to lowest throttle stick.

The other GPS mode I use is PathPlanner (warning!!! advanced!!!) where you set up waypoints.  Only do this after you successfully fly VelocityRoam (or PositionHold).  You create a plan by clicking on the map and then pressing Control-a to add a waypoint.  Make the first one close by so you can watch closely.  Do this several times to make a flight plan.  Drag the waypoints around with the mouse if wanted.  Right click and use the flight plan editor.  You must set the aLtitude and velocity for each leg (they are 0 otherwise).  ALtitude should be at least 4 (meters, above HomeLocation) for safe testing.  Then upload the plan to the FC.  You need a big, open field for first tests.  You must have an accurate (especially aLtitude), close by, HomeLocation stored.  ALtitude is critical.  It will fly at that aLtitude plus the 4 that you put in the flight plan.  Take off and hover fairly close to first waypoint.  Switch to VelocityRoam for a quick test, then switch to PathPlanner mode and watch it very carefully and be ready to switch back to another mode IMMEDIATELY.  It will loop the flight plan over and over till the battery runs out, so you must switch back to another mode and land it when you want to.

If you use a laptop at the flying field, but don't have internet access there, then at home you need to right click the map and do "Rip Map" for your flight area to store the map on the hard drive.  I added all my normal flying sites this way, but only about 300m x 300m for each one or else it takes forever to download.  I actually do a larger area at lower resolution too.

I recommend that you have at least a 3 position flight mode switch (you can very carefully use failsafe mode to make another flight mode and switch the transmitter off for the 3rd position).  You need to take off without GPS and be able to disable GPS in case of a fly away, so use your favorite non-GPS mode for that.  An auto-leveling mode is highly recommended even if you think you want to use Rate, don;t use Rate.  You need to it to auto-level if you have lost visual orientation and it is a long way away...  You need to be able to test it in GPS mode without PathPlanner and also stop it wherever it is if you don't like the path plan, so you need VelocityRoam.  Finally you need PathPlanner mode to actually fly the flight plan.

ggrif

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Re: Revo Position Hold question
« Reply #13 on: August 25, 2015, 10:19:47 pm »
Happy to report 15.05.02 fixed the original problem.

But, it seems to have caused other problems that I shall discuss in a new thread.