DJI Go 4 software glitch causes RTH altitude increase above limits

[Bigbells]

Captioned screen video from this morning's flight shows the problem. This has happened at least 2 times previously.

 

[F3honda4me]

Known issue, DJI should fix in next firmware update. It generally happens when a long ways away and when RTH is initiated when you are already above RTH set height. It's not the GO software, it's an issue in the craft.

 

[rumrunner]

Happened to me today but only up to about 430, almost cancelled and pulled it back manually but it righted itself . It was about a mile out (the furthest I'm willing to go at the moment)


Sent from my iPhone using PhantomPilots

 

[Bigbells]

Theory: RTH is taking the 164 feet that I've set as my RTH altitude and converting it to meters. 164 meters= 538 feet.

 

[F3honda4me]

Theory: RTH is taking the 164 feet that I've set as my RTH altitude and converting it to meters. 164 meters= 538 feet.

It actually appears it has something to do with the craft thinking it has to climb to go over an obstacle.

 

[sakumar]

It actually appears it has something to do with the craft thinking it has to climb to go over an obstacle.

Maybe it's a simple software bug.

RTH AGL altitude = x
Current AGL altitude = y
Number of feet to climb = x - y

Software can't handle -ve values for the last term (when the craft is above RTH altitude).

 

[GadgetGuy]

Maybe it's a simple software bug.

RTH AGL altitude = x
Current AGL altitude = y
Number of feet to climb = x - y

Software can't handle -ve values for the last term (when the craft is above RTH altitude).

That's as good an explanation as any other. It clearly is a bug. Best advice until it is fixed is to set your RTH to higher than you will ever fly during your flight, which is what you should be doing anyway!

 

[snickell]

Theory: RTH is taking the 164 feet that I've set as my RTH altitude and converting it to meters. 164 meters= 538 feet.

I think you theory may be correct - I'm pretty sure that the RTH height is in meters even if you default in the general settings to imperial (feet).


Sent from my iPad using PhantomPilots

 

[GadgetGuy]

I think you theory may be correct - I'm pretty sure that the RTH height is in meters even if you default in the general settings to imperial (feet).


Sent from my iPad using PhantomPilots

No, that theory is unsupported by the data. If you are below the set RTH height, the set value is used correctly.

 

[Bigbells]

No, that theory is unsupported by the data. If you are below the set RTH height, the set value is used correctly.

Yes, I have observed that. When the aircraft has to rise to get to the set RTH altitude, there is no problem. However, that does not disprove my theory. The RTH altitude could certainly be mis-programmed in one case but not in the other. We already know that the horizontal speed is shown in kph even for those of us who have selected mph as the unit of measurement.

I admit that I don't grasp the meaning of the word "firmware". To me, if an issue can be corrected with a downloadable programming change, it's a "software" issue, and if it cannot be corrected with a programming change, it's a "hardware" issue. The distinction which names an in-between 3rd category called "firmware" is lost on me.

 

[Bigbells]

While I'm at it, the 2 options for "cancel Return To Home" should be simply "yes" or "no". The existing options of "cancel" and "OK" are unnecessarily obtuse.

 

[F3honda4me]

Maybe it's a simple software bug.

RTH AGL altitude = x
Current AGL altitude = y
Number of feet to climb = x - y

Software can't handle -ve values for the last term (when the craft is above RTH altitude).

DJI said it's the drone thinking it has to climb over an obstacle falsely. It's nothing to do with meters vs feet. A DJI rep on RCG had me do some tests and upload my dat files. It helped them determine the problem.

Also RTH height preset is ALWAYS in meters. Even if you select imperial measurements. Same goes for max distance and altitude settings.

 

[Bigbells]

DJI said it's the drone thinking it has to climb over an obstacle falsely. It's nothing to do with meters vs feet. A DJI rep on RCG had me do some tests and upload my dat files. It helped them determine the problem.

Also RTH height preset is ALWAYS in meters. Even if you select imperial measurements. Same goes for max distance and altitude settings.

And yet, there is ZERO indication in my video that the P4P perceives an obstacle in front of it. One DJI rep does not constitute a determination. It constitutes a placatory guess. My theory has not been disproven.

In GPS mode, I cannot get my bird to elevate over 394' (120 meters), no matter how hard I try. Are you saying that obstacle avoidance disables the FAA altitude limits? I have doubts.

 

[F3honda4me]

And yet, there is ZERO indication in my video that the P4P perceives an obstacle in front of it. One DJI rep does not constitute a determination. It constitutes a placatory guess. My theory has not been disproven.

In GPS mode, I cannot get my bird to elevate over 394' (120 meters), no matter how hard I try. Are you saying that obstacle avoidance disables the FAA altitude limits? I have doubts.

So you know better than DJI engineers? My info was passed on from the DJI engineers. Also it's not front sensors it's bottom sensing of which there is no indication for.

And again the bug requires a very specific situation to occur, and doesn't happen every time. Also what FAA altitude limit? The drone doesn't have an FAA suggested maximum height limiter. Max height is set by you, up to 500 meters. But the bug can go over the limit. That's what bugs do, they cause things to not work as they should including "limits".

 

[Langstonius]

So you know better than DJI engineers? My info was passed on from the DJI engineers. Also it's not front sensors it's bottom sensing of which there is no indication for.

And again the bug requires a very specific situation to occur, and doesn't happen every time. Also what FAA altitude limit? The drone doesn't have an FAA suggested maximum height limiter. Max height is set by you, up to 500 meters. But the bug can go over the limit. That's what bugs do, they cause things to not work as they should including "limits".

I dunno, i try to pass some of my bugs off as features!
*rimshot*

 

[Bigbells]

So you know better than DJI engineers? My info was passed on from the DJI engineers. Also it's not front sensors it's bottom sensing of which there is no indication for.

And again the bug requires a very specific situation to occur, and doesn't happen every time. Also what FAA altitude limit? The drone doesn't have an FAA suggested maximum height limiter. Max height is set by you, up to 500 meters. But the bug can go over the limit. That's what bugs do, they cause things to not work as they should including "limits".

Yes, if you're in the US, the software has a known altitude limit of 120 meters. Presumably, you are elsewhere.

You really need to stop like acting like a know-it-all. It's very annoying to those of us who do.

 

[F3honda4me]

I dunno, i try to pass some of my bugs off as features!
*rimshot*

Well played.

Yes, if you're in the US, the software has a known altitude limit of 120 meters. Presumably, you are elsewhere.

Incorrect. You can set it in the DJI app to whatever you want. Go into settings, craft settings, max altitude. Considering there is no law that hobbyists have to stay below 400 feet it wouldn't make sense to force that. I am in the US. For hobbyists the 400 feet is a guideline not a law.

 

[F3honda4me]

Screenshot of the max altitude setting. 20 - 500 meters.

 

[Bigbells]

Well played.

Incorrect. You can set it in the DJI app to whatever you want. Go into settings, craft settings, max altitude. Considering there is no law that hobbyists have to stay below 400 feet it wouldn't make sense to force that. I am in the US. For hobbyists the 400 feet is a guideline not a law.

I'll have to give that a try, F3, setting both the maximum flight altitude and the RTH altitude as 0 meters, the way you've indicated in your post.

 

[GadgetGuy]

While I'm at it, the 2 options for "cancel Return To Home" should be simply "yes" or "no". The existing options of "cancel" and "OK" are unnecessarily obtuse.

That's been a pet peeve of mine going back to the P3P! Half the time, you end up selecting the wrong option, and have to rethink, and remember which option makes less sense!