When Your Drone will Return to Home (RTH) and When it Might Not…

[LoudThunder]

I am posting this in the General Discussion Forum even though I am flying a Mini 2, it may affect many other DJI Drone Models.

On another Drone Web Site, one of the members posted that their Mini 2 Drone was working perfectly however the Return to Home (RTH) function did not work and they asked for help. They did not provide any other information.

In my initial reply, I sent them the link to the User Manual and suggested they read the part on setting up the RTH and see if that resolved the problem.

Although the original poster did not reply, I followed-Up with this posting in case others have this issue.

I remember when I flew my Mini 2 in my back yard the first time and I took off from the Deck and flew out 30 or 40 feet and tried the RTH and "something" flashed on the screen but I did not catch it as I was also trying to keep my eyes on the Mini. I tried it again and I caught the message, "RTH Cancelled", but in the excitement of my first flight, I did not give it much thought.

When I was out flying my Mini 2 just for fun the other day, I thought of that RTH posting and I decided to play with the Return to Home (RTH) and I found out some stuff not in the user manual.

I flew the Mini 2 out for a 100 feet or so and tried all four RTH protocols. User press the RTH Button, Loss of Signal (turned off the App and then I also turned off the Controller), and I ran the battery down, and all four worked as specified.

So now I tried some "close-up" RTHs (under 20-meters from HP) and I caught the message this time and recorded it on my Tablet in a screen shot… The FLY App and the Controller will not engage the RTH routine if the Drone is within 20-meters of its Home Point.

I also tried running the battery down and again the Drone would not engage RTH. And I also turned off the FLY App and pressed the RTH on the Radio Controller and as before, it just hovered there. And even if everything is turned off and the battery is on its last legs, the drone will just hover in place until the battery died and the Drone just settled in place.

In the first Screen shot, you can see the message "RTH is unavailable within 20-meters of home point"

A point to mention, the warning did not come up every time I pressed the RTH button, it was just like I had done nothing… But when I pressed it a second time, a message came up on the second push, "RTH Cancelled" so it knew I pressed the RTH the first time, but the App sent no warning…

In the second Screen Shot, you can see the same message and the Low Battery Warning and it hovered until it went into a forced landing.

So, be aware of this limitation (within 20-meters of home point) if you are pushing the boundaries, such as flying FPV and you cannot actually see the drone behind some obstacle (building, tree, etc…) and you want it to RTH or its battery is low and it wants to RTH, it ain't gonna happen…




'

 

[mobilehomer]

It IS in the manual, under 20 meters for the Mini 2, it will hover. Under 5 meters for the Air 2S it will land, same for M3.

 

[Yorkshire_Pud]

Literally experimenting with RTH, as you have been doing, is a very good idea.
Encountering some of these behaviours for the first time in a real RTH could cause panic.
Did you notice the 50m flight retrace in th failsafe?
Other DJI drones add to the RTH permutations available.

 

[March411]

I own a MM2 and haven't needed RTH yet. Great information, thank you!

 

[FLDave]

For the Spark RTH at less then 3 M will trigger an landing. Between 3 and 20 m it will return to home at current altitude (current altitude option disabled). Beyond 20 m it will climb and then RTH.
For the current altitude RTH one really needs to pay attention to those nearby obstacles.
To avoid confusion with different model I just plan to be "far" away from home before triggering RTH.

 

[KennethH]

Okay, so that answers my questions about the RTH not reacting to being pressed. From what I had read, I thought it would react no matter how far the Mini 2 drone was from the launch pad. 20 meters is quite a distance. Something like 60 ft?

Ken

 

[Yorkshire_Pud]

Reading the manual especially in connection with RTH is a good idea but, following that, experimentation really drives the message home. I nearly lost a Phantom 3 because it was within xy of home when I triggered an RTH, yes I was being lazy.

20m = approx 66ft

 

[Ralph thompson]

As said in the first response, read the manual, there’s lots of good stuff in there.

 

[KB9Radio]

I am posting this in the General Discussion Forum even though I am flying a Mini 2, it may affect many other DJI Drone Models.

On another Drone Web Site, one of the members posted that their Mini 2 Drone was working perfectly however the Return to Home (RTH) function did not work and they asked for help. They did not provide any other information.

In my initial reply, I sent them the link to the User Manual and suggested they read the part on setting up the RTH and see if that resolved the problem.

Although the original poster did not reply, I followed-Up with this posting in case others have this issue.


I remember when I flew my Mini 2 in my back yard the first time and I took off from the Deck and flew out 30 or 40 feet and tried the RTH and "something" flashed on the screen but I did not catch it as I was also trying to keep my eyes on the Mini. I tried it again and I caught the message, "RTH Cancelled", but in the excitement of my first flight, I did not give it much thought.

When I was out flying my Mini 2 just for fun the other day, I thought of that RTH posting and I decided to play with the Return to Home (RTH) and I found out some stuff not in the user manual.

I flew the Mini 2 out for a 100 feet or so and tried all four RTH protocols. User press the RTH Button, Loss of Signal (turned off the App and then I also turned off the Controller), and I ran the battery down, and all four worked as specified.

So now I tried some "close-up" RTHs (under 20-meters from HP) and I caught the message this time and recorded it on my Tablet in a screen shot… The FLY App and the Controller will not engage the RTH routine if the Drone is within 20-meters of its Home Point.

I also tried running the battery down and again the Drone would not engage RTH. And I also turned off the FLY App and pressed the RTH on the Radio Controller and as before, it just hovered there. And even if everything is turned off and the battery is on its last legs, the drone will just hover in place until the battery died and the Drone just settled in place.

In the first Screen shot, you can see the message "RTH is unavailable within 20-meters of home point"

A point to mention, the warning did not come up every time I pressed the RTH button, it was just like I had done nothing… But when I pressed it a second time, a message came up on the second push, "RTH Cancelled" so it knew I pressed the RTH the first time, but the App sent no warning…

In the second Screen Shot, you can see the same message and the Low Battery Warning and it hovered until it went into a forced landing.

So, be aware of this limitation (within 20-meters of home point) if you are pushing the boundaries, such as flying FPV and you cannot actually see the drone behind some obstacle (building, tree, etc…) and you want it to RTH or its battery is low and it wants to RTH, it ain't gonna happen…

View attachment 147218


'View attachment 147219

All good responses coming from folks. All DJI drones have a different RTH response if you are within a certain distance of the HP. Most are 20 to 30 meters or so and should be in the manual. Within that distance they either hover or land right where they're at, most land where they are. Beyond that distance they do a standard RTH depending what is setup in your settings. All this of course is assuming you waited at takeoff for GPS lock and the HP to be recorded, if not all bets are off. If you didn't wait for a GPS lock, your HP will be recorded at some point during your flight, but probably not near you. To test I always go out 40 to 50 meters before pressing the button and it always lands within a foot of the launch spot.

 

[Zbip57]

Another thing to watch out for in a "normal" RTH beyond 20m radius from the Home Point. Lets say, for example, you have set your RTH height to 50m. My Mini-1 and Phantom-3 will climb to 20m, turn to face Home, then continue to climb to the set RTH height of 50m before flying a straight line to Home. However, if you touch the throttle stick any time during the climb above 20m height, the drone will NOT continue to climb to the set 50m RTH height, but will stop climbing and will instead RTH at whatever height it's currently at when you moved the throttle stick.

Moving the throttle stick during the climb, once above the minimum 20m climb height, will cancel any further automatic climb. You can still manually adjust the height, and which direction the drone is facing (yaw), while the drone is flying in RTH. But if it's out of sight at the time, don't fiddle with the throttle, or you might be surprised when the drone returns at a height other than the expected 50m RTH height.

 

[Capt KO]

Just be sure RTH is only set high enough to fly over surrounding obstacles. Otherwise you will hit high winds alloft and waste precious battery on return. If possible, always take over manually when in sight. I never let it return auto if manual available.

 

[LoudThunder]

I know I'm being overly careful, but whenever I fly, I check the UAV Forecast App, then knowing the max legal altitude I can fly, I loft straight up, with a heading of due North. Then at various increments to max height, I stop momentarily and do a four-point check, (N, E, S, and W) and I check the Attitude meter to see if my poor Mini 2 is struggling with the wind and from what direction. One thing I do not want to do is find out that at just over tree level there are gusts so strong I would struggle to return home because that "tail wind" was stronger than I thought…

 

[wienog]

I am posting this in the General Discussion Forum even though I am flying a Mini 2, it may affect many other DJI Drone Models.

On another Drone Web Site, one of the members posted that their Mini 2 Drone was working perfectly however the Return to Home (RTH) function did not work and they asked for help. They did not provide any other information.

In my initial reply, I sent them the link to the User Manual and suggested they read the part on setting up the RTH and see if that resolved the problem.

Although the original poster did not reply, I followed-Up with this posting in case others have this issue.

I remember when I flew my Mini 2 in my back yard the first time and I took off from the Deck and flew out 30 or 40 feet and tried the RTH and "something" flashed on the screen but I did not catch it as I was also trying to keep my eyes on the Mini. I tried it again and I caught the message, "RTH Cancelled", but in the excitement of my first flight, I did not give it much thought.

When I was out flying my Mini 2 just for fun the other day, I thought of that RTH posting and I decided to play with the Return to Home (RTH) and I found out some stuff not in the user manual.

I flew the Mini 2 out for a 100 feet or so and tried all four RTH protocols. User press the RTH Button, Loss of Signal (turned off the App and then I also turned off the Controller), and I ran the battery down, and all four worked as specified.

So now I tried some "close-up" RTHs (under 20-meters from HP) and I caught the message this time and recorded it on my Tablet in a screen shot… The FLY App and the Controller will not engage the RTH routine if the Drone is within 20-meters of its Home Point.

I also tried running the battery down and again the Drone would not engage RTH. And I also turned off the FLY App and pressed the RTH on the Radio Controller and as before, it just hovered there. And even if everything is turned off and the battery is on its last legs, the drone will just hover in place until the battery died and the Drone just settled in place.

In the first Screen shot, you can see the message "RTH is unavailable within 20-meters of home point"

A point to mention, the warning did not come up every time I pressed the RTH button, it was just like I had done nothing… But when I pressed it a second time, a message came up on the second push, "RTH Cancelled" so it knew I pressed the RTH the first time, but the App sent no warning…

In the second Screen Shot, you can see the same message and the Low Battery Warning and it hovered until it went into a forced landing.

So, be aware of this limitation (within 20-meters of home point) if you are pushing the boundaries, such as flying FPV and you cannot actually see the drone behind some obstacle (building, tree, etc…) and you want it to RTH or its battery is low and it wants to RTH, it ain't gonna happen…

View attachment 147218


'View attachment 147219

This has been the normal routine for every DJI -drone for many many years. RTFM

 

[KennethH]

This has been the normal routine for every DJI -drone for many many years. RTFM

Finally got DJI Fly to cooperate, and set the distance setting to Imperial. Now I can deal in good 'ol feet.

 

[mickmmm]

Hi, I'm here because I'm desperate. I actually have rth problem with a SJRC F11 pro 4k etc.
I use my drone to walk about for exercise in and out of empty goal post etc. So auto RTH on low battery creates havoc for me as at low altitude it will attempt rth around 15 minutes and this could be a dangerous U turn with me or a tree on its way.
Here I also like to stress my surprise that hardly no one mention that the H in RTH is actually not home but where you last started your drone. I'm quite a beginner but with many accidents and broken parts due to the auto rth not mentioning the loss of about 10 out of 26 minutes flight on my control.
I was thinking trying to 'block a battery pin to negate that auto rth and wondering about my chance to succeed.
Another thing that makes me wonder is about the 'follow me mode' I have not had a chance of experimenting with this. But can anyone tell me what is likely to happen with this mode when the low battery triggers rth?
The next 'wondering' situation is about GPS not activated. Why the low battery manages to trigger a rth when there is no gps activated?
This also lead me to discover (with my drone) that it is so much easier to start it in non gps mode and then add it when it's flying rather than twirling the aircraft vertically and horizontally.

 

[rscheff]

WOW. It seems like the RTH feature is baffling to many. I fly the Mini 1 and about 3 or 4 months ago I flew out of range and the drone just hovered. I was plenty high enough (140 ft) for the area so I just waited for RTH to activate. It did not, I counted off 40 seconds and started getting nervous and drove towards the drone. I regained contact and control within 100 feet. I just started flying again within the last 2 weeks, I suffered 2 bad drones in a row that were returned under warranty. I remembered this incident with the RTH so I decided to experiment. I flew the drone to an abandoned baseball field, approximately 400 feet from my house and 140 feet in air. I unplugged the RC creating a disconnect, nothing happened, the drone just hovered for about a minute. I pressed the RTH button on RC and of course nothing happened, I then used the sticks and of course nothing happened. I finally just plugged the RC back in and gained control. The manual says RTH is supposed to activate after 11 seconds of disconnect. Is there something wrong with the drone of the software?

 

[zeusfl]

Not exactly related to the Mini 2 but there is valuable information in this video that I created.

 

[Zbip57]

I flew the drone to an abandoned baseball field, approximately 400 feet from my house and 140 feet in air. I unplugged[?} the RC creating a disconnect, nothing happened, the drone just hovered for about a minute.

Two things. When you say unplugged, do you mean you unplugged the USB cable between the controller and your phone, or you actually turned off the controller?

You can continue to fly the drone even with the phone and app disconnected, it only needs the controller working.

If you switched the controller off, then the Failsafe response to lost control signal should kick in 11 seconds later.

The second thing to check, in the Fly app, click on the "..." three dots in the upper right corner of the screen. Then under the "Safety" tab, scroll all the way to the bottom of the screen to "Advanced Safety Settings". There you can change the default response to Control Signal Lost, choosing between "Return to Home, Descend, or Hover".

If that is set to "Hover", then your drone will behave exactly as you described. Make sure that's set to "Return to Home" unless you have an actual need to use either of the other settings.

Also beware, if control signal is lost when the drone is within 20m of the recorded Home Position it will automatically land where it is, not actually return to home.

 

[rscheff]

I unplugged the RC from the phone by physically unplugging. I have my RTH set to RTH. I flew a couple flights just a few moments ago and I tried a couple things. I tried unplugging and turning off. Yesterday I flew at least 4 times but there was only one flight log and one entry for connection lost, it said; "Downlink data connection lost (call it ddcl) for 65.7 seconds, Mode changed to Go Home (call it RTH).

Today I flew twice but there was only one flight log, I don't know why it's not recording all. I repeated the testing of RTH several times and in a nutshell every time I unplugged the RC, RTH was not initiated automatically. I believe it might have been initiated by me by hitting the RTH button, but I am not sure about that because I did not write it down.

Every time I shut off the RC RTH was initiated automatically. In both cases the error msg. was the same, "AC disconnected from RC". I did this test 6 times, here are the results:

ddcl lost for 70.6 seconds - mode changed to RTH
ddcl lost for 34.6 seconds - mode changed to RTH
ddcl lost for 38.8 seconds - NO RTH
ddcl lost for 43.6 seconds - mode changed to RTH
ddcl lost for 1.8 seconds - NO RTH
ddcl lost for 62.7 seconds - NO RTH

In the cases where there was NO RTH I physically plugged the RC back in. If I just left the RC unplugged until battery down to 19 % I don't know what will happen, have to try that next.

There were a lot of messages in the flight log of severe interference so I am assuming the ddcl lost for 1.8 seconds was actually interference.

Off the subject, but when using DJI Fly and the drone is within 20m, RTH will result in drone landing right where it is and not returning to the RTH height (for me 140 feet). Also if battery drops to 19% it will land right where it is if within the 20m distance. BUT if using Dronelink and flying a program, if the AC is within the 20m distance and RTH is initiated the drone will go to designated height and the return to the launch point. Also if battery drops to 19% and the mission is near complete, the drone will keep flying until mission is complete and then land on the spot. This is within the 20m distance, I think if the drone is beyond the 20m distance it will activate the DJI RTH protocol.

 

[mickmmm]

I can't really comment as my drone is quite different although it has similar features. But in many flights only twice it landed near me on battery exhaustion (far from the launching area) I have no idea why.
And in the opposite situation when the battery was exhausted, also a couple of times only, it landed quite far from the launching pad, easily 20 metres (don't use imperial units)