Correct response to flight software freezing?

[Synonomau5]

Various people have reported loss of flight control due to flight software freezes in both DJI and Litchi software.

Some people have tried to reset the software (shutdown and reboot DJI Go or Litchi while aircraft hovers), but then report that the aircraft does not 'return to home (original takeoff location)' due to the reset, and is still not controllable, and lands in its current position (which could be over water, or wherever).

Is there a known fail-safe protocol for recovery, which would allow the operator to regain control without use of the flight software (i.e. sticks only)?

I am new to DJI software, and have just purchased the I2/X5s and will control it with a cell/GPS-enabled iPad Pro. I'm wondering if the iPad GPS can remain integrated with connection loss (i.e. I2 will 'follow me' for return to home), or failing that, be made controllable via sticks-only?

 

[JoePGM]

would like to know how actually the I2 will behave if the Go apps freeze or crashed during flight? will it stop and hover in the position, will it RTH immediately (suppose the I2 will store the home point or GPS data for emergency use) or just land immediately?

 

[SanCap]

would like to know how actually the I2 will behave if the Go apps freeze or crashed during flight? will it stop and hover in the position, will it RTH immediately (suppose the I2 will store the home point or GPS data for emergency use) or just land immediately?

The app is not needed to fly. You can start the I2, take off and land without ever turning the app on. If the app crashes inflight as long as you have line of sight you can easily fly it back to where ever you want it to go.

 

[Synonomau5]

The app is not needed to fly. You can start the I2, take off and land without ever turning the app on. If the app crashes inflight as long as you have line of sight you can easily fly it back to where ever you want it to go.

As a newb to the I2, what is the procedure for taking manual control of the craft if it 'hangs and hovers' due to software issues. (If it hangs up over water, for instance, I need to get it back over land ASAP).

 

[The Editor]

Various people have reported loss of flight control due to flight software freezes in both DJI and Litchi software.

Some people have tried to reset the software (shutdown and reboot DJI Go or Litchi while aircraft hovers), but then report that the aircraft does not 'return to home (original takeoff location)' due to the reset, and is still not controllable, and lands in its current position (which could be over water, or wherever).

Is there a known fail-safe protocol for recovery, which would allow the operator to regain control without use of the flight software (i.e. sticks only)?

I am new to DJI software, and have just purchased the I2/X5s and will control it with a cell/GPS-enabled iPad Pro. I'm wondering if the iPad GPS can remain integrated with connection loss (i.e. I2 will 'follow me' for return to home), or failing that, be made controllable via sticks-only?

Yes, occasionally if the app crashes it will not release the USB port until after a few seconds (which can feel like an eternity when you cannot control your aircraft using the sticks).
In situations like this, the fastest way to regain control is to pull the USB lead out of the remote. This will instantaneously release the USB port (since there is no handshake/data) and you will get control back faster than waiting for the port to release via firmware.

 

[Synonomau5]

Yes, occasionally if the app crashes it will not release the USB port until after a few seconds (which can feel like an eternity when you cannot control your aircraft using the sticks).
In situations like this, the fastest way to regain control is to pull the USB lead out of the remote. This will instantaneously release the USB port (since there is no handshake/data) and you will get control back faster than waiting for the port to release via firmware.

THANK YOU. Very good info.

 

[NickU]

Best thing to do is go somewhere with good all-round visibility where you can play safely, then try out the various scenarios to see what happens - hitting rth at various distances, dumping the app, restarting the app, pulling the usb cable, putting the cable back in, toggling ATTI mode to get control back from automation, power down RC & so on - that way you get used to what happens when the smelly stuff hits the fan *before* it happens in real life - eases some of the panic attack and "WTF!!!" moments

It also teaches you keep cool, fly with sticks only, and not to always rely on the rth function because it doesn't alway do what you'd expect it to (eg when the app has crashed & restarted & reset the home point!).

 

[Synonomau5]

That is my plan.

I'm also wondering if I have the iPad w/ GPS and Cellular, does the GPS work if the Cellular is on 'airplane mode'?

If so, what settings do you use for RTH to adapt to location of the RC (follow me), and does that all work if you have to 'pull the plug' on the ipad and reboot, if there's a software freeze...

(I've only had RTH self-activate a couple times, and all I can say is I was REALLY lucky (older P2 w no collision sensors)).

 

[JoePGM]

Yes, occasionally if the app crashes it will not release the USB port until after a few seconds (which can feel like an eternity when you cannot control your aircraft using the sticks).
In situations like this, the fastest way to regain control is to pull the USB lead out of the remote. This will instantaneously release the USB port (since there is no handshake/data) and you will get control back faster than waiting for the port to release via firmware.

I'm curious, the USB port on our RC have immediate relationship with the control of I2?

 

[JoePGM]

As a newb to the I2, what is the procedure for taking manual control of the craft if it 'hangs and hovers' due to software issues. (If it hangs up over water, for instance, I need to get it back over land ASAP).

The app is not needed to fly. You can start the I2, take off and land without ever turning the app on. If the app crashes inflight as long as you have line of sight you can easily fly it back to where ever you want it to go.

From what SanCap said, it sounds like the apps freeze will not causing the flight control lose, is it? Can we interpret the apps and tablet are just tools for visual aid and auto pilot stuff, however the bird can still totally controllable with pure RC without tablet?

 

[NickU]

From what SanCap said, it sounds like the apps freeze will not causing the flight control lose, is it? Can we interpret the apps and tablet are just tools for visual aid and auto pilot stuff, however the bird can still totally controllable with pure RC without tablet?

Yes, it's purely a visual aid. The RC is the really important thing that controls the aircraft.

If an App freezes, then several things can happen:

1. Nothing! You're cool, just restart the app and carry on. Watch out though - check where your home point is set to as the app may reset it to the current aircraft position when it restarts - you may need to manually reset the home point to the RC's location instead.
2. if flying under pilot control, then the RTH options MAY kick in or not. It depends on what has been lost App only, App & RC Signal - the RTH options will normally only activate if the Remote controller signal is lost for several seconds - that isn't the same as the video downlink being lost, or app control being lost. Getting home is easy... you carry on flying with the RC & sticks, and manually fly the aircraft home... of course you're a good law abiding person and are operating within line of sight at all times, so flying home isn't hard! If you haven't restarted the app yet (ie changed the Home point), then you could manually activate RTH - but you need to know what it will do - rth/hover/land!
3. If the RC signal is lost for several seconds, then RTH should automatically activate - so the aircraft will either ascend to the set RTH height then fly home, or hover until it gets the RC signal back, or it will land if within a certain distance of the RC - depends what you set in the RTH options. When the RC is back in signal range you can cancel the RTH and fly manually again.
4. Your tablet freezes up and needs restarting. Don't panic! Simply hover the aircraft in a safe spot, or land if safe to do so, and restart the app. If the App starts again and doesn't show the live video feed, then try unplugging & re-inserting the cable, it may have a bad connection. So long as the RC is still in range, you can fly manually regardless of the state of the App.
5. If an autonomous mission or automation flight has been uploaded to the aircraft, then the aircraft normally carries on doing what it was programmed to do - depends what response was set in the mission programming - it could be carry-on & return at end of mission, carry on & hover at end of mission, abort mission & return home, abort mission and hover... it does what you told it to do at the start of the mission. If you have RC control, but no app control and want to abort the mission and take over manually, then you can toggle the flight mode switch from P-GPS/S-GPS to ATTI to cancel the automation. Be careful in ATTI mode as the aircraft will drift with the wind... so you may want to toggle straight back to P-GPS or Sport to regain GPS position hold. The automation shouldn't restart and you should have manual control back. See 2 above for further help!

Don't panic and start hitting every button around - that's when things go wrong! Where things go wrong too is where you restart the app, think "Phew", then as you're a bag of nerves, hit the manual RTH button, and the aircraft either lands immediately or flies of somewhere! Then you think WTF!! oh no! Of course home is now not where it was (the app has reset it!)

That's why it's important to try the options out and find out what happens first! Also, don't use the RTH buttons as a lazy way to come home - they may not do what you thought they'd do!

 

[SanCap]

From what SanCap said, it sounds like the apps freeze will not causing the flight control lose, is it? Can we interpret the apps and tablet are just tools for visual aid and auto pilot stuff, however the bird can still totally controllable with pure RC without tablet?

Yes, it is easy to test. Just turn on your remote controller and the Inspire without your tablet/phone plugged into the remote. Start up the Inspire and fly for test purposes only.

 

[JoePGM]

Of course home is now not where it was (the app has reset it!)

The home position is marked by the bird location or RC location?

 

[JoePGM]

Thanks alot the detail description by NickU

 

[NickU]

The home position is marked by the bird location or RC location?

If there's adequate GPS signal, then the take off/launch point of the ac is used to set the 'Home' point. Restarting the app or switching to another app will re-record the new home point as the ac's in flight position.

If you're following something over a distance and keep landing at various points during the flight, then the home point resets to the new take off point each time. You can also manually set the home point to the current ac position in flight from the DJI Go App - IIRC you can also set it to the controller position manually.

 

[JoePGM]

hmmm..... then it sounds like our RC location help nothing for the home point even our tabet with GPS function?

I purchase the DJI GPS module with my I2, but everything still never start, as I know the GPS module could help dynamic homepoint location , I will suppose it could help in this scenario which provide GPS position as homepoint even the I2 take off from another location......

 

[NickU]

According to the manual, the GPS add-on updates the RC position as the home point.... in "Follow Me" mode. It doesn't say if it works that way in other modes.

The way to tell what it's doing is to look at your inflight map and see where the tear-drop shaped H icon (for home point) is positioned If you're moving at it's where the ac took off from, then the home point isn't updating dynamically. If it's at your current RC position, then it is updating dynamically. If it hasn't updated dynamically, then you can manually set the home point to the current on using the DJI Go app. i can't recall if you can do it from the map screen, or if you have to do it from another screen.

 

[JoePGM]

so, that sounds like the homepoint update of RTH feature has to rely on the tablet and DJI Go apps.... it cannot perform by a pure hardware-level process

 

[NickU]

Only in 'Follow me' mode which is one of the 'special' modes like tripod, tap fly etc.

 

[Synonomau5]

So the question is regarding emergency protocol:

Example: Flying I2 in 'tripod' mode shooting/flying over a large pond. App freezes. I2 goes to hover mode, 30% battery remaining, 15 mph wind.

Option 1:
Unplug USB cord to iPad w/ GPS+cell (in airplane mode, cell off)
Reconnect iPad, Go4 reconnects, immediately change to 'follow me' mode
Battery continues to deplete, worst case, I2 will 'follow me' and land near where RC is located (otherwise it would land in the water?)

Option 2:
Unplug USB to ipad
I2 automatically becomes immediately controllable with sticks (with no other 'switching' inputs).
However, I2 must immediately be flown to safe landing area, as once battery reaches (X%?) it will otherwise try to land itself back over the water, in the position it was in when the USB was unplugged.

Can anyone comment as to whether any or all of the above is correct?

Any other solutions/instructions?