Strange and a little troubling issue with RTH and at some other times.

[Bobthinks]

I've seen this strange issue when my Anafi is completing a RTH. Occasionally, right about the time the ultrasonic sensor should start being able to detect the ground, it pitches around wildly and drops like stone. Most of the time I've seen this it was after dark and I assumed it was a glitch caused by the positioning camera being unable to see ground while the ultrasonic sensor is suddenly showing a wildly fluctuating distance measurement (which is normal for ultrasonic sensors when they go out of maximum range and start detecting within range). I've been able to recover it every time. Up until the last time.

The last time it happened was during the day. While overcast it was still very bright. It was moderate wind with gusts. In watching the video you can see the effects of gusts as occasionally the gimbal cannot quite keep up with lateral effect of the drone keeping the drone on it's current path. However when flying northerly it would appear to be fighting gusts, but occasionally would slew violently left. It always recovered and aside from the motor noises there was nothing to indicate that this was any more than it fighting a gust laterally when watching from the ground. Only when I reviewed the video did it become apparent. However when descending it again when perhaps 14-16 ft off the ground, pitched wildly and abruptly dropped. This time it had nearly impacted the ground right as the motors came back to life at full power and bounce a little pitching it just sideways enough for it to veer into some railing. No real damage resulted that I can see beyond a couple of broken blades.

Has anyone seen anything similar to this? Here is the video. The RTH starts 1 second into the video.

I'm going to re-calibrate it before flying again and if that does not solve it I will continue up through resetting everything. And contacting Parrot.

 

[Dirk_ANAFI]

That is not ok!
Also with lateral wind the gimbal should stabilize the image!
So if recalibrating everything does not help: send the Anafi back!

 

[nicholashickman]

I've seen this strange issue when my Anafi is completing a RTH. Occasionally, right about the time the ultrasonic sensor should start being able to detect the ground, it pitches around wildly and drops like stone. Most of the time I've seen this it was after dark and I assumed it was a glitch caused by the positioning camera being unable to see ground while the ultrasonic sensor is suddenly showing a wildly fluctuating distance measurement (which is normal for ultrasonic sensors when they go out of maximum range and start detecting within range). I've been able to recover it every time. Up until the last time.

The last time it happened was during the day. While overcast it was still very bright. It was moderate wind with gusts. In watching the video you can see the effects of gusts as occasionally the gimbal cannot quite keep up with lateral effect of the drone keeping the drone on it's current path. However when flying northerly it would appear to be fighting gusts, but occasionally would slew violently left. It always recovered and aside from the motor noises there was nothing to indicate that this was any more than it fighting a gust laterally when watching from the ground. Only when I reviewed the video did it become apparent. However when descending it again when perhaps 14-16 ft off the ground, pitched wildly and abruptly dropped. This time it had nearly impacted the ground right as the motors came back to life at full power and bounce a little pitching it just sideways enough for it to veer into some railing. No real damage resulted that I can see beyond a couple of broken blades.

Has anyone seen anything similar to this? Here is the video. The RTH starts 1 second into the video.

I'm going to re-calibrate it before flying again and if that does not solve it I will continue up through resetting everything. And contacting Parrot.

woah that's bad!

 

[Landbo]

I've seen this strange issue when my Anafi is completing a RTH. Occasionally, right about the time the ultrasonic sensor should start being able to detect the ground, it pitches around wildly and drops like stone. Most of the time I've seen this it was after dark and I assumed it was a glitch caused by the positioning camera being unable to see ground while the ultrasonic sensor is suddenly showing a wildly fluctuating distance measurement (which is normal for ultrasonic sensors when they go out of maximum range and start detecting within range). I've been able to recover it every time. Up until the last time.

The last time it happened was during the day. While overcast it was still very bright. It was moderate wind with gusts. In watching the video you can see the effects of gusts as occasionally the gimbal cannot quite keep up with lateral effect of the drone keeping the drone on it's current path. However when flying northerly it would appear to be fighting gusts, but occasionally would slew violently left. It always recovered and aside from the motor noises there was nothing to indicate that this was any more than it fighting a gust laterally when watching from the ground. Only when I reviewed the video did it become apparent. However when descending it again when perhaps 14-16 ft off the ground, pitched wildly and abruptly dropped. This time it had nearly impacted the ground right as the motors came back to life at full power and bounce a little pitching it just sideways enough for it to veer into some railing. No real damage resulted that I can see beyond a couple of broken blades.

Has anyone seen anything similar to this? Here is the video. The RTH starts 1 second into the video.

I'm going to re-calibrate it before flying again and if that does not solve it I will continue up through resetting everything. And contacting Parrot.

It looks like the camera's gimbal "freaks out" first in the clip.

An Anafi must not land on that way. Something could indicate that the bottom sensors do not work properly.

I would contact the seller to get it repaired on the warranty.

Regards Leif.

 

[dashSolo]

My experience is to go manual every time you have it in sight. Giving you positive control in the last critical phase of flight.

 

[joshmentele]

I've seen this strange issue when my Anafi is completing a RTH. Occasionally, right about the time the ultrasonic sensor should start being able to detect the ground, it pitches around wildly and drops like stone. Most of the time I've seen this it was after dark and I assumed it was a glitch caused by the positioning camera being unable to see ground while the ultrasonic sensor is suddenly showing a wildly fluctuating distance measurement (which is normal for ultrasonic sensors when they go out of maximum range and start detecting within range). I've been able to recover it every time. Up until the last time.

The last time it happened was during the day. While overcast it was still very bright. It was moderate wind with gusts. In watching the video you can see the effects of gusts as occasionally the gimbal cannot quite keep up with lateral effect of the drone keeping the drone on it's current path. However when flying northerly it would appear to be fighting gusts, but occasionally would slew violently left. It always recovered and aside from the motor noises there was nothing to indicate that this was any more than it fighting a gust laterally when watching from the ground. Only when I reviewed the video did it become apparent. However when descending it again when perhaps 14-16 ft off the ground, pitched wildly and abruptly dropped. This time it had nearly impacted the ground right as the motors came back to life at full power and bounce a little pitching it just sideways enough for it to veer into some railing. No real damage resulted that I can see beyond a couple of broken blades.

Has anyone seen anything similar to this? Here is the video. The RTH starts 1 second into the video.

I'm going to re-calibrate it before flying again and if that does not solve it I will continue up through resetting everything. And contacting Parrot.

A $700 drone should not do this. Send it back. I am finding the Anafi to be increasingly unreliable and buggy. If I were you, I would replace it with an Autel Evo. It is an amazing quad, almost zero issues with it.

 

[Dirk_ANAFI]

A $700 drone should not do this. Send it back. I am finding the Anafi to be increasingly unreliable and buggy. If I were you, I would replace it with an Autel Evo. It is an amazing quad, almost zero issues with it.

Bobthinks describes the behaviour of a defective drone.
There is no reason to recommend another drone.

 

[Bobthinks]

Bobthinks describes the behaviour of a defective drone.
There is no reason to recommend another drone.

Specifically I'm hoping that it is a corrupted GPS/Compass calibration. I've done some toying around with GPS and electric compasses and I strongly suspect that my compass calibration is very off and what you are seeing is a logic tug of war between the compass and the GPS information. That is only started doing it in the last 5 flights and that it is primarily occurring during one direction of flight or at sensor transition zones is what leads me to believe that.

I'm nowhere in the realm of the developer that Parrot, Autel or DJI are at when it comes to this but I've done some experimentation with automated navigation. Proximity, GPS and Compass are all less that 100% reliable. Any number of things can momentarily knock one or all of them off line. If GPS was momentarily offline, or the GPS was differing in altitude from the ultrasonic height sensor, if I was the developer I would probably look to cross check one of my three axis's against the compass to try and determine which of the other two is incorrect. Bummer if the compass is 45 degree out, as it may then assume GPS is wrong. I really hope this is the case as if not then either my compass is bad or the GPS unit is faulty and I'm going to be sending this thing to Parrot.

Anyhow I wanted to see if anyone else has seen this behavior in any form. I'll be starting with a re-calibration, then the progressive resets. I'll keep everyone informed in what I find.

A $700 drone should not do this. Send it back. I am finding the Anafi to be increasingly unreliable and buggy. If I were you, I would replace it with an Autel Evo. It is an amazing quad, almost zero issues with it.

Several other people on here know I was 150% set on getting a EVO early in 2018. I watched the entire roll out fiasco unfold. I'm still interested in it and keeping abreast of it's development. I expect any new drone to have teething pains and would forgive a lot. Autel, however, pulled back so much of what they had promised it turned me off purchasing one for the foreseeable future. And saying there have been almost zero issues with it is at best disingenuous. It's fantastic to have options in the drone space and I hope each and every owner has the best possible experience regardless of the brand. But we have to be honest about each and every make and models flaws. Without us pushing every maker, the space will never achieve its potential.

 

[Bobthinks]

That is not ok!
Also with lateral wind the gimbal should stabilize the image!
So if recalibrating everything does not help: send the Anafi back!

The only reason I'm not concerned with the lateral stabilization that I did not include in the clip is that it was direction consistent and while it was not in the forecast I went out with, as I was flying we got weather alerts about straight line winds of over 40MPH. I think the gusts in question simply overwhelmed gimbal in terms of degree of swing and speed of swing. It's been fine in gusts otherwise. (Obviously not when talking about the slewing.)

 

[Bobthinks]

My experience is to go manual every time you have it in sight. Giving you positive control in the last critical phase of flight.

I went auto RTH because while I was already bringing it back, I lost visual on it. I lost it in the gray of the cloud cover above and behind it.

But that aside, even if I rarely use it, I need to be able to trust it. Slewing like that is... lets just go with bad.

 

[Jagerbomb52]

I had posted a video of mine that went a little crazy in high winds, once it straighten itself out it was fine. These things are very light and do very well in high winds but there has to be a point where something has to give.

 

[Bobthinks]

I had posted a video of mine that went a little crazy in high winds, once it straighten itself out it was fine. These things are very light and do very well in high winds but there has to be a point where something has to give.

Did yours slew like that? I was going to look for your video but yikes 513 messages. You've been busy.

 

[Jagerbomb52]

 

[Bobthinks]

Ok, nearly identical. Reassuring actually. That doesn't explain the issue as it's descending, but I'm more confident about calibrating fixing that.


HEY EVERYBODY! Tip of the day. When the Anafi encounters gusts beyond it's stabilization threshold it may slew wildly. Apparently there's a downside to that big old bug butt hanging out the back.

 

[Bobthinks]

<Professor Farnsworth Voice>Good news everyone!</ Professor Farnsworth Voice> The calibration worked. I had to do it twice, because it said the calibration failed the first time. But the second time worked great and it was decending and executing RTH's just fine. It even encounter gusts without slewing so hard.