RTH problems

Hi guys,

we face some problems regarding RTH/Fail-Safe with our copter.

We do have a CS6, 13x6.5 Carbon props on KW Motors with two 4s5000.
WKM 5.08 (scared to update to 5.12 ;))

We have received the copter with 5.06. Everything was fine.
After the update to 5.08 we had a tiolet bowl behavier and unstable straight forward flight.

We have re-done the gains settings.
@5.06: 175/125/175/175 Attitude 80/80
no we have 155/115/155/155 Attitude 80/80

Toilet bowl was still there (clockwise)

As we have a magnetic declination at our location of 2 degree east, we have turned the GPS clockwise a little bit. Toilet bowl became worse, and the drift in straigt forward flight as well.

So we have turned the GPS to the left, aprox 10 degree.
After setting IMU Z to the right value of -7 (@5.06 it was at +7 by mistake without interfering stability), toilet bowl was gone and copter flies straight forward.
perfect ;)

But then tested RTH.
The hexa descended normally (without wobbling araund).
But then the copter didn't find his home position.
It flew around the starting point in a diameter of aprox. 10mtr. descending slowly, but with increasing horizontal speed.
I switched back to atti mode and landed safe.

We have tried it several times, allways having good GPS signal (no red blinking).
We have also waited 1-2 mins before take off. Unfortunately without success. Copter was everytime surrounding the former starting point with a diameter of aprox. 10mtrs after RTH/fail-safe activated.

Then we have checked with Groundstation.
The hexa had no value in homepoint!
After setting the homepoint by clicking "set homepoint" before take-off, everything went as it should. Hexa landed safe, smoothly and perfectly on his former starting point.

Any ideas?
Is there a known bug in 5.08?
As we not have connected X2 for IOC we do not expect to get the green lights for Homepoint autosave.

As far as I know, other GPS devices need some time (several minutes) to get their GPS location if they're powered up the first time, or at an location far away from former location, as they have to "download" satelote data first.
Is this something to consider after a WKM firmware update?

Any hints welcome.

Frank
 
Last edited by a moderator:

Dewster

Member
I had a similar issue while using RTH. The first time worked as advertised. I launched it and used the RTH and watched it land perfectly. The second time that I tried it there was a little wind which I think caused it to start circling to land. It was like it couldn't find it's home point anymore. The wind died down and yet my craft kept circling as if it were stuck in some kind of a loop. I didn't realize that I could regain control of the craft, by switching flight modes from GPS to Attitude so I watched and preyed that it wouldn't crash into anything.

On calm wind days (no breeze) it works as advertised. I use the RTH feature to bring my craft back to it's Home Position and watch it as it begins it's descent. I usually just retake control of the craft once it returns and I'm able to orient the direction it's facing. I like the feature because it's like an obedient dog. It returns home when you call it. :) It's just that sometimes I'll have to put the leash on earlier if it's windy out.
 


I have checked with GroundStation the homepoint GPS value only.
All commands were given by RC.
The RTH was activated by U channel (GPS Atti/Atti/fail-safe)

during the first take offs, there was no value in the "Homepoint field" of GS.
Copter circled around the take off location.

After setting the homepoint in GS manually by clicking the corresponding buton, homepoint location was visible in GS.
After switching U to failsafe, copter landed safe.
 

Tahoe Ed

Active Member
You may have had a conflict with your RC commands and the information that was being transmitted via Data Link. I would test the RC without the Data Link connected and see if that works.
 

Maybe my description was not clear enough ;)

I have not used GS for testing first.
Copter behavior was as he simply does not automatcally store the homepoint at take-off.

RTH is working perfectly as soon as I manually store the homepoint using GS.

maybe I was too impatient before take off, but there was not red blinking for more than one minute before take off.

Frank
 

Droider

Drone Enthusiast
Frank is this on the first flight of the day?

I have a little routine I follow because of past unpredicted results on first flight of the day. I use one pack to get full GPS LOCK. I then fly around using that one pack as pre-mission checks. I then fly the mission on a new pack.. I may have OCD but it seems to work well for me

Dave
 

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