Hello everyone and hope everyone has a awesome day... can someone help please with my P4 7flight old wiggle issue please... 6 flights all went great but yesterday I took off to a hover about 18’ high and my bird started a dance... wiggled like she was being tickled .. any ideas ?

Hello there. We apologize for the inconvenience. Can you provide us a sample video showing the problem?

Calibrate the IMU and go a little higher to gain more satellites.

DJI Wanda Posted at 2018-8-7 06:25
Hello there. We apologize for the inconvenience. Can you provide us a sample video showing the problem?

I'm sorry but i did not get a vid, I will try again after work and if it happens again I'll make sure i get a video of it. Thanks for your reply. Have a great day !

ALABAMA Posted at 2018-8-7 06:41
Calibrate the IMU and go a little higher to gain more satellites.

Thats funny you mention the IMU because I've been having a heck of a time calibrating said IMU... And i was in a tight area when hovering ... Car in front house on the right and trees everywhere else.  I'd say less than a 20 foot radius . was going to shoot some video of my property . I could not get the IMU to Cali, but just watched one of your videos on this matter so i will attempt to recalibrate after work today and get back to you. Thanks again for your help and replies !

Reds2tall55 Posted at 2018-8-7 07:00
I'm sorry but i did not get a vid, I will try again after work and if it happens again I'll make sure i get a video of it. Thanks for your reply. Have a great day !

Alright. I'm looking forward to it. You can download it via youtube or Dropbox then send us the link. Thank you. Have a great day too.

Quite possibly the biggest disturbance yesterday would be the updraft from the aircraft itself bouncing back off ground below.

If it were a bit higher up then I'd be tempted to calibrate the VPS (Visual Positioning System), the VPS works up to 10m (33ft) from the ground and should do what it says. It holds horizontal position relative to images the lower cameras capture of the ground. The ultrasonic transducers below also help to maintain and measure altitude up to 10 metres from surface below.

Having said that, there will always be some room for error, from the P4 spec;s:-

Hover Accuracy Range
Vertical:
±0.1 m (with Vision Positioning)
±0.5 m (with GPS Positioning)
Horizontal:
±0.3 m (with Vision Positioning)
±1.5 m (with GPS Positioning)

Reds2tall55 Posted at 2018-8-7 07:05
Thats funny you mention the IMU because I've been having a heck of a time calibrating said IMU... And i was in a tight area when hovering ... Car in front house on the right and trees everywhere else.  I'd say less than a 20 foot radius . was going to shoot some video of my property . I could not get the IMU to Cali, but just watched one of your videos on this matter so i will attempt to recalibrate after work today and get back to you. Thanks again for your help and replies !

IMU needs to be calibrated on a flat but also Level surface, the calibration registers with the aircraft what it should take to be level. A nice dead flat & level kitchen worktop or suchlike is ideal.

In my opinion, when sampling GPS signal, Z calculation is the least accurate coordinate (meters in fact). It is a know issue of GNSS. Even so that with a starting group of too few satelites to calculate the Z coordinate from, losing or getting a new satelite in the sample can make your drone recalculate several centimeters higher or lower. You can experience this issue in areas with poor GPS coverage.