Randomly gaining altitude with no input, Suggestions ?

[Lerroy]

Hi all

Having problems with my phantom 2 / H4-3D gaining altitude whilst inputting and command from right stick (pitching or rolling)

This is how the flights go:

1. Take off all ok 7+ GPS
2. Fly around at about 40 metres no problems seems to be going well
3. All of a sudden the phantom shoots up to about 70 meters by itself
4. I let go of the sticks and the phantom will come back down by itself to the 40 meters what was at before the sudden altitude gain.
5. Fly around again no problems, 30 seconds later and it shoots up...

I have tried numerous things to solve the problem..

• Unplugged TX
• Unplugged Gimbal and turned off Go pro
• Removed IOSD, TX and DJI hub (latest attempt)
• Reset BMU ,Advanced Calibration, Basic Calibration
• Calibrate controller in both software programs
• Tested on ATTI mode still does the same thing
• Return to home / Turned off controller - even the RTH still shows the same symptoms as it flew back gained altitude multiple times, it did however get back to me.
• Calibrated compass away from interference
• turned off my mobile in my pocket
• tried numerous locations and same locations that previously were working fine
• Different conditions tested windy, no wind, different times of day
• Balanced and changed the props
• Have tried 2 different batteries

My kit is Phantom 2 (latest version of 2) H4-3D, iOSD mini, AVL58 Lite, DJI Hub, Go pro 4 black, ND filter and IBcrazy Blue beam antennas.

Any help would be greatly appreciated

 

[RoyVa]

First I would re- calibrate the IMU and then re-calibrate the RC sticks. Then go outside and calibrate the compas. That should fix the issue if it doesn't then you may have the left stick hanging. Plug to the assistant and slowly move it up and down and watch the screen to see if it reacts accordingly. When you throttle up and release it back to center on screen it should do the same thing just as fast. Any lag and you may have an issue. Give it a shot.

 

[Lerroy]

First I would re- calibrate the IMU and then re-calibrate the RC sticks. Then go outside and calibrate the compas. That should fix the issue if it doesn't then you may have the left stick hanging. Plug to the assistant and slowly move it up and down and watch the screen to see if it reacts accordingly. When you throttle up and release it back to center on screen it should do the same thing just as fast. Any lag and you may have an issue. Give it a shot.

Thanks for the advice

I tried the controller calibration today and I cant see any problems with any lag on the throttle.
When I switched off the controller to force RTH mode it did the same thing whilst flying back to me so i have sort of check the controller off the list as cause...could be wrong though

Also did a IMU calibration, controller and compass, thought I had fixed it but few minutes into the flight it started doing it again

 

[Lerroy]

Just updated the post to make more sense and after recent flights a more clear problem diagnosis

 

[jason]

Thanks for the advice

I tried the controller calibration today and I cant see any problems with any lag on the throttle.
When I switched off the controller to force RTH mode it did the same thing whilst flying back to me so i have sort of check the controller off the list as cause...could be wrong though

Also did a IMU calibration, controller and compass, thought I had fixed it but few minutes into the flight it started doing it again

You know that RTH/Failsafe are one and the same. So if the RTH limit is set to 70m and your flying at 50m and you trigger RTH the quad will turn facing home point ascend to 70m and return to the home point.

 

[Lerroy]

You know that RTH/Failsafe are one and the same. So if the RTH limit is set to 70m and your flying at 50m and you trigger RTH the quad will turn facing home point ascend to 70m and return to the home point.

Thanks for reply

Yeah I'm aware it will fly up to RTH height set (60m) then come back to me which it did, but on the return flight back (flying forwards) it will throttle up beyond the RTH 80-90m height limit a few times.

I was thinking it was loosing signal and then throttling up, but the iosd readout and lights underneath never seem to change

 

[jason]

Thanks for reply

Yeah I'm aware it will fly op to rth height then come back, but on the return flight back (flying forwards) it will throttle up beyond the rth height limit a few times.

I was thinking it was loosing signal and then throttling up, but the iosd readout and lights underneath never seem to change

This is from your first statement: "Return to home / Turned off controller - even the RTH still shows the same symptoms as it flew back gained altitude it did however get back to me."

If you were flying at 40m high and turned off the RC and the RTH was set at 70m that is the altitude it will ascend to which is normal. Now if your are higher than 70m and RTH is triggered it will not descend to 70m but stay at the higher altitude.

I believe someone said you may have throttle stick problem and to connect the RC unit and P2 the software and check the throttle stick movement. Have you??

 

[Lerroy]

This is from your first statement: "Return to home / Turned off controller - even the RTH still shows the same symptoms as it flew back gained altitude it did however get back to me."

If you were flying at 40m high and turned off the RC and the RTH was set at 70m that is the altitude it will ascend to which is normal. Now if your are higher than 70m and RTH is triggered it will not descend to 70m but stay at the higher altitude.

I believe someone said you may have throttle stick problem and to connect the RC unit and P2 the software and check the throttle stick movement. Have you??

Thanks, yes I have tested the throttle stick in the RC software and i cant see any problems with it lagging or doing anything strange. I'm not actually touching the throttle at all normally when the altitude gains.

The RTH / Failsafe functions does this

1. Flying at 40 meters
2. Turn off controller
3. Drone lights flash and it ascends to 60m as set in software (RTH limit)
4. Starts to come back to me, as its coming back raises to 90m all of a sudden, stops coming back and descends again to 60m and proceeds to come back once more. it will do this a few times if its far away (200m)

* edited my original post to "multiple times gaining altitude"

 

[jason]

Thanks, yes I have tested the throttle stick in the RC software and i cant see any problems with it lagging or doing anything strange. I'm not actually touching the throttle at all normally when the altitude gains.

The RTH / Failsafe functions does this

1. Flying at 40 meters
2. Turn off controller
3. Drone lights flash and it ascends to 60m as set in software (RTH limit)
4. Starts to come back to me, as its coming back raises to 90m all of a sudden, stops coming back and descends again to 60m and proceeds to come back once more. it will do this a few times if its far away (200m)

* edited my original post to "multiple times gaining altitude"

You know of course there are two stick calibrations not just one. The same procedure has to be done in P2 as well.

 

[Lerroy]

• Calibrate controller in both software programs

Have done both multiple times to be sure..

 

[Lerroy]

Changed to a new controller, no luck same problem.



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