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Anafi 'bunny hopping' on landing

delly.x

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Hi folks, I'm a recent Disco to Anafi migrant and have been enjoying my first few flights. I had a strange experience twice in a row yesterday and just wanted to get some opinions.

So, landing my Anafi in my back yard, on a nice flat patio, with hand launch/land disabled. I press the land button, Anafi comes down as normal, but then decides to lift an inch or two and starts hopping over to the right, as if it could not get the required status to cut the props, despite being initially firmly on the ground. As it had hopped over to under a swing set, I did not want to risk taking off again, so went in and under to grab it from behind, to stop it hopping further. While this was successful, I got a nasty gash for my troubles, but managed to do the 90 degree turn to power down.

Now after this, I did an inspection of the props to ensure they were okay and did a controlled take off and landing and it did the bunny hop again. After this, I did a full reset of all components and did five take off/landings without incident. So my question is if anybody else has had this happen, or is it possible that there is something else I missed out on. Thanks.
 
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I press the land button, Anafi comes down as normal, but then decides to lift an inch or two and starts hopping over to the right, as if it could not get the required status to cut the props, despite being initially firmly on the ground.
Mine is a little random in doing this too, always has been, but what makes for gentler landings is when you have a high contrast pattern underneath it! Landing pads are perfect, I always get gentle landings on mine, as compared to bitumen, paver's, grass, sand, stones. I suspect it is all to do with the downward facing inbuilt camera underneath the body & what it can discern.

I also find the same is true in relation to accuracy of landing proximity on RTH.
 
Hi folks, I'm a recent Disco to Anafi migrant and have been enjoying my first few flights. I had a strange experience twice in a row yesterday and just wanted to get some opinions.

So, landing my Anafi in my back yard, on a nice flat patio, with hand launch/land disabled. I press the land button, Anafi comes down as normal, but then decides to lift an inch or two and starts hopping over to the right, as if it could not get the required status to cut the props, despite being initially firmly on the ground. As it had hopped over to under a swing set, I did not want to risk taking off again, so went in and under to grab it from behind, to stop it hopping further. While this was successful, I got a nasty gash for my troubles, but managed to do the 90 degree turn to power down.

Now after this, I did an inspection of the props to ensure they were okay and did a controlled take off and landing and it did the bunny hop again. After this, I did a full reset of all components and did five take off/landings without incident. So my question is if anybody else has had this happen, or is it possible that there is something else I missed out on. Thanks.

There are two reasons why your Anafi can make a "kangaroo landing".

1. The landing site is not on even ground so Anafi does not have all four legs on the ground at the same time when she comes down.

2. At the landing site, the "soil" absorbs the signals from the ultrasound sensor so that Anafi believes there is nothing below on the landing site and thus comes down at great speed and thus jumps up again.

The downward facing camera cannot "see" how high up Anafi flies but is used instead to find the starting point with pattern recognition.

You do not need to use the start/land button to land, but can instead keep the height stick completely down which gives you control over the down speed. Note you must hold down the stick for about 2 seconds before Anafi reacts on the last 50 cm and goes down.

Hope it helps in understanding hov to finding a suitable place to start and land and the best way for you to do it.

Regards, Leif.
 
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There are two reasons why your Anafi can make a "kangaroo landing".

1. The landing site is not on even ground so Anafi does not have all four legs on the ground at the same time when she comes down.

2. At the landing site, the "soil" absorbs the signals from the ultrasound sensor so that Anafi believes there is nothing below on the landing site and thus comes down at great speed and thus jumps up again.
On Saturday night when my Anafi stopped recording at the beach after 32 seconds, she bunny hopped about 50cm to the right on landing! I landed on a solid, level surface, which was made of timber decking with narrow gaps between decking strips that was well illuminated. I find on grassy surfaces & the rubber padding on the playground across the road from us that it lands very hard & fast, even with me manually controlling its descent, stopping about 60cm AGL, then pushing the stick down & holding it.

The only consitently soft landings I get are when I use my landing pad, which is bright orange with the giant white "H" & a few other markers on it..
 
Mine does it even on level ground on a landing pad. Parrot Support still hasn't been able to explain it. Every time I come in for a landing I have to wonder will it be the last... Very unsettling to watch.
 
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I have progressed to only hand landings due to the very stubby legs on Anafi, except when launching from clean sidewalks/asphalt. Might add a glove to the left hand for this, as last time my outstretched fingers were kissed by the furthest blade, fortunately it was the trailing edge of the prop, spinning away from and not into my fingers, so no harm done. Or maybe use a short breadboard with handler say a ping pong paddle, to hold under the bird for a manual landing pad. I have only done a couple hand launches, but it worked well.
 
My anafi too has started to bunny hop on landing, I did post about it here awhile back (maybe it was on facebook) started happening after the last update. Some times it lands ok, some times it bounces around and seems like it is going to flip over... very concerning, generally I land on level grass, but the same issue occurs on paved brick floor, heli pad on the beach... Just waiting for the day it flips and breaks :(
 
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The bunny hop has been around for a long time. Mine did it w couple of times back in Aug. Seems the downward facing senors are not fine tuned enough for some landings. I seem to remember when it happened to me it was on very bright sunny days. Maybe the reflection from the sun might have something to do with it. UAV's that have OV have trouble when facing into the sun like the Autel EVO.
 
I think Agustine has the right explanation: the reflexions of the bright light on the landing surface then on the Anafi bottom camera could be the clue even if the ‘blind sonar’ says ‘Ok for me, we touched something hard and close enough to be the ground’, the algorithm that crosses informations of both the sonar and the bottom camera may think ‘if there is still light here, I did not land yet officially or let me try this again just to be sure’.

It would be easy to check, when it happens, just making a shadow between the landing area and the sun with your body.

— Edit —
I did not mean to say ‘anybody equipped with a large body’, but instead, proposing ‘any body would be fine’...
... sorry about this one, won’t do it again, promised...
 
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Mine has bunny hopped once. I used the stick on the controller to land it.
I thought maybe I had released it too soon.
 
Hi all, thanks for the many experiences. I am happy to say at least that I'm not on my own and the tips mentioned will help a lot. Like a lot of things, it's best to be prepared when landing, so at least I know it can happen.
 
I have the same every now and then and Anafi hopped around on the landing pad as well as on other leveled surfaces on bright days and overcast conditions --- plus it sometimes refuses to land where I want to land it. Last time it escaped within the last 30 cm above ground to the left, avoiding the landing pad and luckily got caught in the soft grass beside it, recording the landing as a crash.
 

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