Mavic Air 2 return to home cancelled

[tigermothrob]

I took a recent flight where it was indicated that I had lost signal lock, distance away was about 2,600 feet. It appeared that I still had control but to be safe I activated the RTH button. The command was acknowledged on screen but the drone made no move. A message of 'RTH cancelled' then flashed on the left of the screen. Process repeated, and same result. As I could see the field I had taken off from, I flew back manually and landed. Being a bit short on battery power, I manually reset the RTH home point and took off going only about fifty yards away. RTH worked perfectly then.
Any ideas what caused this?
Regards

 

[msinger]

Any ideas what caused this?

Please upload the TXT flight log here and share the link with us.

 

[Yorkshire_Pud]

There was a 'recent' and VERY quite quiet change, relating to stick use, that now can cancel an RTH.
You'd need to search/google for it but I think it might relate to the throttle, I can't remember if they did something to the use of the elevator as well.
My interest was in the Mavic Mini and the Mini 2 and I do not know if it affected other Fly app using drones.

It used to be that if the drone was above a certain height, 20m?, but still climbing to RTH height, moving the throttle in a certain direction cancelled the remaining climb and started the flight home. The change, whatever it is, now cancels the RTH full stop, NOT A GOOD THING in my opinion.

As I said you'd need to google it. From memory the thread didn't attract much attention.

 

[tigermothrob]

There was a 'recent' and VERY quite change, relating to stick use, that now can cancel an RTH.
You'd need to search/google for it but I think it might relate to the throttle, I can't remember if they did something to the use of the elevator as well.
My interest was in the Mavic Mini and the Mini 2 and I do not know if it affected other Fly app using drones.

It used to be that if the drone was above a certain height, 20m?, but still climbing to RTH height, moving the throttle in a certain direction cancelled the remaining climb and started the flight home. The change, whatever it is, now cancels the RTH full stop, NOT A GOOD THING in my opinion.

As I said you'd need to google it. From memory the thread didn't attract much attention.

Many thanks for this. I would try things out today but it chucking it down and gusting to 40mph. Typical British weather!!!

 

[Yaros]

The change, whatever it is, now cancels the RTH full stop, NOT A GOOD THING in my opinion.

Noticed that recently too. Not a good change...

 

[Zbip57]

It used to be that if the drone was above a certain height, 20m?, but still climbing to RTH height, moving the throttle in a certain direction cancelled the remaining climb and started the flight home.

The user manual for my Mini says that. Once above 20m, if you touch the throttle stick, it will stop climbing and return at its current height. Of course that can only happen if you still have a good control signal.

There was a 'recent' and VERY quiet change, relating to stick use, that now can cancel an RTH.
You'd need to search/google for it but I think it might relate to the throttle, I can't remember if they did something to the use of the elevator as well.

I found this in the user manual for the Mini 3 Pro.

 

[Yorkshire_Pud]

The user manual for my Mini says that. Once above 20m, if you touch the throttle stick, it will stop climbing and return at its current height. Of course that can only happen if you still have a good control signal.

Yep I know and that was a good behaviour.
But it is also worrying since I think I have the latest version of the manual, yet people have reported, and I myself may have experienced, that touching the throttle, to cancel the remaining climb, (in my case a mini 2 or perhaps a Mavic Mini) cancelled the entire RTH. The latter behaviour is not documented in the manual or, as far as I know, in update released notes.

With regards to the second quotation that might be Mini 3 only, with the Mavic Mini I did a lot of RTH playing and I have the distinct impression that I was able to force a Mavic Mini to fly away from the home point during an RTH by giving reverse stick, possibly up to full reverse, as soon as I released the elevator the drone started to head for home again. I also think I was able to send it left and or right but that is a much less certain recollection.

 

[Zbip57]

But it is also worrying since I think I have the latest version of the manual, yet people have reported, and I myself may have experienced, that touching the throttle, to cancel the remaining climb, (in my case a mini 2 or perhaps a Mavic Mini) cancelled the entire RTH. The latter behaviour is not documented in the manual or, as far as I know, in update released notes.

DJI make changes and never update the manual. I'll have to experiment some more with my Mini...

With regards to the second quotation that might be Mini 3 only,

Yes, that was a quote from the Mini 3 Pro manual. Different models may (and do) behave differently. It's always a good idea to run your own experiments and not to trust what others say.

with the Mavic Mini I did a lot of RTH playing and I have the distinct impression that I was able to force a Mavic Mini to fly away from the home point during an RTH by giving reverse stick, possibly up to full reverse, as soon as I released the elevator the drone started to head for home again. I also think I was able to send it left and or right but that is a much less certain recollection.

I also did lots of experiments with my Phantoms, and with my Mini, but that was a while ago. Things may have changed.

If I remember correctly, while the Mini is enroute in RTH you can adjust its height and yaw angle, but not alter its path. Once it has stopped overhead the Home Point and started its descent, then you can adjust its position left/right, forward/back, even up/down, and it will continue its descent from there on when the sticks are released.

 

[Yorkshire_Pud]

.....but not alter its path......

we'll not argue, my own experiment were quite some time ago too.
If you don't mind me asking, I'd be interested in your comments in the 'mini 3 in a restriction zone' thread.

 

[Zbip57]

we'll not argue, my own experiment were quite some time ago too.

Certainly not arguing. Just pointing out that it is possible that there may be differences in how each model behaves. If the weather cooperates, maybe I'll fly my Mini tomorrow and do some more tests.

 

[Yorkshire_Pud]

"Argue" was perhaps the wrong word, disagree or debate might have been better.

 

[Zbip57]

If the weather cooperates, maybe I'll fly my Mini tomorrow and do some more tests.

The weather is perfect today, sunny, dead calm, +4°C, however...

We had a major winter storm and blizzard over Christmas and lost power for two days. We're lucky as there are other areas still without power. We have our own generator and managed to keep the house from freezing. The biggest inconvenience [first world problems] is that our high speed internet cable connection died, and hasn't been restored for nearly a whole week now. We've instead been using our expensive cellphone data connection as hotspot.

I meant to go out today to make a new video showing how my Mini reacts to stick inputs during RTH. I can still do that, but I cannot post the video until our internet connection is eventually restored.

In the meantime, I made a series of four videos 3 years ago with the Mini. Originally on the Mini the only Failsafe response to lost control signal was RTH. I demonstrated how that might be a problem if ever you found yourself in a situation where a strong wind was carrying your Mini away and you tried to do an emergency landing to ditch the drone in a remote landing site before it was carried away beyond control signal range. DJI eventually updated the app and firmware to add the Failsafe options of Hover or Land. The 4th video shows the benefit of that.

Anyway, I did plenty of RTH experiments with the Mini in these four videos. But I don't think I ever tried to see if full stick inputs actually cancelled RTH, as described on the page from the Mini 3 Pro manual in post#6 above. Here's that playlist:

https://youtube.com/playlist?list=PLLngMU-9AtNNXcGwtXZh7o_qpB7qKwgb4

 

[Zbip57]

Okay, I did some test flights with my Mini (original Mini-1) today and its behaviour is still the same as always was.

I can't post the video yet because I still have no high speed internet connection.

If it loses control signal it stops and hovers, pausing for 11 secs to see if it regains signal, before engaging its selected Failsafe option of RTH, Hover, or Land.

Or, if you have full control signal and choose to initiate a RTH, you can push the Home button on the controller or app screen and it pops up a menu choice of,

• if its currently more than 20m away from the Home Position, an option of RTH or Land; or
• if closer than 20m to the Home Position, only Land.

Choose RTH and it starts climbing until reaching 20m height, then turns to face toward the Home Position before continuing to climb to its configured RTH altitude.

If at any point after 20m in its climb you move the throttle stick at all, it stops climbing and heads for Home at its current height, even if there are trees in the way. (Don't touch the throttle stick unless you truly want this to happen!)

Once it's underway heading Home in a straight line, you can raise or lower its height using the throttle stick, you can yaw it to rotate the camera view left or right, you can speed it up on its straight path Home with forward stick or slow it down and even reverse direction with reverse stick (regardless of which direction it's currently facing), but you cannot move it to the left or right to deviate from that straight-line path to Home.

Once it has reached a position directly overhead of the Home Point and begun its descent, now you can move it left or right, forward or back, yaw either direction, slow or stop its descent or even make it climb with throttle application, all control sticks working. But if you release the sticks it will continue its descent to auto-land wherever you've just steered it to, unless it decides it doesn't like the look of your chosen landing spot and landing-protection kicks in to prevent a full landing. Then it will hover and prompt you for confirmation that you really intend it to land in this swamp.

Anyway, that's the way the original Mini-1 behaves with the most recent firmware and Fly app versions. Other models do behave differently.

The user manual for the Mini 3 Pro says if, while it is climbing in RTH, you pull the throttle all the way down, the Mini 3 Pro will stop and hover cancelling RTH. I confirmed that is not the case for the Mini-1. Once higher than 20m, touching the throttle in any way stops the climb and the Mini immediately heads for Home at its current height.

The user manual for the Mini-3 Pro says, once it's in forward flight heading Home in RTH, if you pull the right stick fully back, the Mini 3 Pro will brake to a halt and hover cancelling RTH. Not so for the Mini-1. If you hold the right stick fully back, the Mini will slow down and eventually reverse direction. Release the stick and it recommences forward flight continuing to head straight Home.

The user manual for the Mini-3 Pro says, if it is more than 50m away from the Home Position when control signal is lost, the Mini 3 Pro will reverse flying backwards to retrace the previous 50m of its path before doing the standard climb to RTH height and straight path home. That's much fancier than the Mini-1.

It's important to study the user manual for your own model, they're all different, and practise using its various processes so you won't be surprised when something unexpected happens.

 

[Yorkshire_Pud]

Cheers @Zbip57 I guess I got things mixed up in my head concerning lateral movement but the thing about touching the throttle? cancelling the RTH with some drones is real.

 

[AmericaPacific42]

There was a 'recent' and VERY quite quiet change, relating to stick use, that now can cancel an RTH.
You'd need to search/google for it but I think it might relate to the throttle, I can't remember if they did something to the use of the elevator as well.
My interest was in the Mavic Mini and the Mini 2 and I do not know if it affected other Fly app using drones.

It used to be that if the drone was above a certain height, 20m?, but still climbing to RTH height, moving the throttle in a certain direction cancelled the remaining climb and started the flight home. The change, whatever it is, now cancels the RTH full stop, NOT A GOOD THING in my opinion.

As I said you'd need to google it. From memory the thread didn't attract much attention.

There was a time where you could use RTH yourself (as opposed to just have it activate if the aircraft loses the remote,) which allowed you to rotate the aircraft, set the speed, set capture mode, take videos/pictures etc. while autopilot made the aircraft itself fly straight towards where it took-off from.
If they added the ability to stop RTH if you move the aircraft laterally (as opposed to require you to tap RTH to put RTH back off,) that could be useful, but it would be cool if they let you rotate the camera or film with it while it does RTH.

 

[Yorkshire_Pud]

There was a time where you could use RTH yourself (as opposed to just have it activate if the aircraft loses the remote,) which allowed you to rotate the aircraft, set the speed, set capture mode, take videos/pictures etc. while autopilot made the aircraft itself fly straight towards where it took-off from.
If they added the ability to stop RTH if you move the aircraft laterally (as opposed to require you to tap RTH to put RTH back off,) that could be useful, but it would be cool if they let you rotate the camera or film with it while it does RTH.

You can yaw, through 360deg or more or less, with a Mavic Mini and I think the Mini 2 whilst flying towards the home point and in RTH. You can also yaw a Mavic 2 Pro or Zoom but you need to switch something off in the app. Meaning they could RTH sideways, and if you played with the home point whilst it was doing this you could create a sideways etc. waypoint mission for the minis.
I can not comment on other drones.

BUT cancelling the RTH during a climb via a throttle touch is IMO a very BAD idea, especially when it is introduced 'quietly' and people are used to it merely stopping the climb when above 20m anf below RTH height.

 

[Yorkshire_Pud]

The user manual for my Mini says that. Once above 20m, if you touch the throttle stick, it will stop climbing and return at its current height. Of course that can only happen if you still have a good control signal.

Just tested joystick movements duing various parts of the RTH. Closing the throttle during the c;limb to excess height merely started the flight home, and during that movement perpendicular to the flight home was not possible but it could be spun like a top.

BUT with a mini 2......... I dug out a test flight log. During RTH No sideslip was possible, the drone could be spun but closing the throttle during the climb to excess height cancelled the RTH, I didn't test the response to playing with the elevator.

 

[Zbip57]

with a mini 2 [...] closing the throttle during the climb to excess height cancelled the RTH.

Checking the User Manual v1.4 for the Mini 2, I found the following.

With the original firmware v1.0.0.0, the Mini 2 behaved just like the Mini 1. While climbing in RTH, if you touch the throttle stick any time after the drone has climbed at least 20m, it stops climbing any further to the configured RTH height and instead returns at its current height.

Updating to firmware v1.1.0.0 or newer, the behaviour changed to that of the Mini 3. RTH is cancelled if the throttle is held full down during the climb portion, or the elevator stick is held full back during the forward flight portion of RTH. The drone will stop and hover.

 

[Yorkshire_Pud]

I take it back then, not so quite, whoops.

 

[Zbip57]

I take it back then, not so quiet, whoops.

But you are correct in saying the RTH behaviour of the Mini 2 was changed.