P4P Erratic behaviour since FW update
641 2 2017-3-9
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Ulysse
Second Officer
Flight distance : 1389931 ft
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Belgium
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I have my P4P since 4 weeks (coming from a P3P and then a P4 I have since 1 year now).
During the first days (24 and 26 February), I was able to test the quad during 2 flights and everything was perfect (despite high winds) so I was able to put all my attention on image quality and settings. But from February 27 till today the weather here was a nightmare so it was impossible to fly.

This morning, after a quick weather and NOTAMs check, it was the day to make some other tests : Helicopter Training Area (military) closed at 4.00 pm and not too much wind (between 5 and 7 m/s).
So this morning, I decided to update everything : latest FW for the quad, the R/C, IMU calibration (a very small bias before calibration and 0 after), Gimbal and stick calibration.
Arriving at my usual test field, in the middle of nowhere, I did my checklist from the first point to the last and click on the takeoff button : the I checked the box to allow the quad to record precisely the takeoff point (it climbs to 6m high and there is a beep, I presume indicating the point has been precisely recorded or is this the AF beep ?).

On the first leg with head wind, everything was perfect. But after turning to go back to me the quad almost stops, while still having 100% forward stick input and a tail wind !!!
I managed to get it back to me using Sport mode (despite my comment in the video which is a mistake)
Tried ATTI mode without any success. Using Sport mode it started again to go at a "normal" speed and when arriving near me, I tried to put it down into a nice glide slope as I always do and the quad refuses to descend, even with 100% stick input.

Of course, the EXP setting is not an explanation of this behavior as 100% stick input equal 100% stick output, whatever the EXP setting you have.
I decided to land, power off the quad and calibrate the sticks.
Power up again and everything was fine till I gain some latitude again (30 meters).
I never had any yaw or climb problem during the 2 flights I made today : only descent and forward !
Also I had a perfect RC and video signal during the flights, without a single frame drop.
On Healthydrone, the wind analysis shows a gusting wind almost were the quad stops the first time but I didn't notice such a wind on location.

Then I tried RTH in order to check the precision landing. my RTH height is always 60meters but for this test, I changed the RTH height to 20 meters while the quad was in flight (don't know if this is updated in the quad while in flight or not).
I put the quad 50m away and press the RTH button on the RC. While the quad was above the home point, it continues to climb far over the 60m setting and I had to cancel RTH and had a lot of difficulties to get it down.

Any idea DJI-***** people ?






2017-3-9
Use props
Ulysse
Second Officer
Flight distance : 1389931 ft
  • >>>
Belgium
Offline

Just made some tests in the flight simulator and sticks are responding perfectly.
2017-3-9
Use props
Ulysse
Second Officer
Flight distance : 1389931 ft
  • >>>
Belgium
Offline

New tests today after downgrading the FW. Still the same problem : erratic behaviour and climb over RTH height during RTH.
Disabling VPS seems to solve the erratic response to the sticks
2017-3-10
Use props
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