Why doesn't DJI provide smarter return to home functionalities when the connection is lost?

[FoxhallGH]

I must have missed those posts. So the Mavic in question could have flown upwind if flown manually in P mode, but not in RTH? That seems like a bad software implementation.

Edit: Why is Da*n censored? Is this a Christian forum?

Not necessarily - This situation can come about due to somebody flying downwind at low altitude, and then when they press RTH, the drone going up high into faster air. I remember a post where someone took off from a clearing in a forest and flew around at tree-top height (out of VLOS), then did a RTH - but the drone never reappeared. Analysis of the logs showed that it was maxed out trying to get back to the clearing but since it had risen into faster winds, it was literally blown backwards and away from the operator.
In that situation, you need to identify that the wind speeds are high at altitude (UAV Forecast app / Mavic wind warnings / observed speed into wind), and get the drone back to you by dropping down to hedge height and manually flying it in calmer air.
It's not so much 'bad software' - but bad flying ...
RTH is a nice feature, but it's not a panacea for all ills!

 

[Meta4]

I must have missed those posts. So the Mavic in question could have flown upwind if flown manually in P mode, but not in RTH? That seems like a bad software implementation.

That sounds like confusion.
The Mini can achieve 8 m/s (P Mode) in still air.
Its has the same top speed in RTH Mode.

 

[Lurch003]

I must have missed those posts. So the Mavic in question could have flown upwind if flown manually in P mode, but not in RTH? That seems like a bad software implementation.

Edit: Why is Da*n censored? Is this a Christian forum?

Where did you get that from? Think you're confused bud. It's a great software implementation alongside basic piloting skills and understanding of the capabilities of the UAV.

 

[slup]

I must have missed those posts. So the Mavic in question could have flown upwind if flown manually in P mode, but not in RTH? That seems like a bad software implementation.

Edit: Why is Da*n censored? Is this a Christian forum?

Mmm, as the rest already have said ... think you misunderstand thing's.

As pointed out all drone models have set max air speeds, usually one for each base mode (RTH, P & Sport) ... the RTH mode for the Mini have the same speed as P-mode ... 8m/s.

These max speeds is achieved by the AC pitch (or tilt) ... which also are limited to different angles for P & Sport (20 degrees for P & 30 degrees for Sport).

So ... this means as already pointed out, that trying to fly into a head wind of 8m/s in P-mode for a Mini, equals to 0m/s in ground speed & a Mini that pitches down 20 degrees, & as a note, if the wind is stronger than 8m/s the Mini will drift backwards.

If you still have connection with the Mini you can switch to Sport ... which will generate max 13m/s air speed, meaning 13-8(wind)= 5m/s in ground speed & a Mini that pitches down 30 degrees.

And it's these facts that regulate everything ... and it works in the same way for all drone models, besides that, other models can have a higher max speed & an even steeper pitch angel ... which means they can make way into higher wind speeds before they end up with 0m/s ground speed.

When the connection is lost you no longer can switch to Sport mode ... instead it's the specs from the RTH mode that sets how fast winds the AC can handle before it's stopped & starts to be blown away ... this is how it work for all DJI AC, the only difference is the speed specs.

The only way to mitigate the risk to be blown away if you're unsure about the wind speeds aloft ... is to fly out into the wind, if the AC can't make way it will be blown back to you, giving you a possibility to maintain the connection & switch to Sport & drop altitude.

 

[RayOZ]

There is a limit to how ‘smart’ DJI would want to make the RTH. They need to make it as simple and straight forward. In the event of an accident and someone got hurt or property got damaged, someone needs to be held responsible. Not DJI.
I don’t think it’s a good idea for DJI to descend automatically anywhere besides home point or when battery level is critical. Imagine someone flying over a major highway on a windy day. And the drone descends on reduce wind resistance to 5ft above ground to fly straight home. It’d have to cross the highway.
Keep it simple, predictable, safe and make pilots responsible for when, how and where they fly.

 

[JAW]

My feeling is many new(ish) pilots set their RTH altitude too high with the thought being higher is better.

While this may be true in situations where the pilot is surround by trees or other structures in such a way that a higher RTH allows better/quicker visual sighting, for the most part a RTH that's 20 feet above the highest obstacle is sufficient. This is especially critical when surface winds are a poor predictor of winds at, say, 400 feet. A 10 mph surface wind will very often exceed the drones headwind fighting ability at 400 feet, so why set your RTH altitude to 400 feet if the highest obstacle in your intended flight area is only 200 feet high?

But but.....what if the highest obstacle is 400 feet? Well, you have a few choices---don't fly, adjust your take-off location so that your return path will have a tailwind, fly in S mode with its higher top speed, or just say ef it, and fly anyway.

 

[DrizzyDrones]

Question.. i saw places that said rth cant use sport mode .. is this true if you are already in sports mode before the rth is activated? I am sure I have been in sports mode and rth didn’t change the mode back to p mode once active. I rarely let rth run its course but it was still in sports mode when I canceled it

 

[FoxhallGH]

Question.. i saw places that said rth cant use sport mode .. is this true if you are already in sports mode before the rth is activated? I am sure I have been in sports mode and rth didn’t change the mode back to p mode once active. I rarely let rth run its course but it was still in sports mode when I canceled it

The 'P' in 'P mode' is from GPS. The Mavic needs to be firmly under guidance from its known and remembered GPS positioning info when it carries out an RTH. Therefore, you can consider the flight spec's of the Mavic during the RTH flight home, as being 'P mode'. The only way you can get the Mavic from RTH P mode into any 'S mode' configuration is to cancel the RTH and switch to S.

 

[DrizzyDrones]

Yea put if i an in sports mode and hit the rth button the S doesn’t change controller beeping and it says its in sports mode during the rth just wondering if it gives the mini the sports mode speed while rth... all I know is that if i have sports mode on after the rth starts the app still shows ib sports mode

 

[Meta4]

Question.. i saw places that said rth cant use sport mode .. is this true if you are already in sports mode before the rth is activated?

Yea put if i an in sports mode and hit the rth button the S doesn’t change controller beeping and it says its in sports mode during the rth just wondering if it gives the mini the sports mode speed while rth...

RTH is a flight mode on its own.
If you are in Sports Mode, and the drone loses signal and initiates RTH, it changes flight mode to RTH.

 

[FoxhallGH]

Yea put if i an in sports mode and hit the rth button the S doesn’t change controller beeping and it says its in sports mode during the rth just wondering if it gives the mini the sports mode speed while rth... all I know is that if i have sports mode on after the rth starts the app still shows ib sports mode

I think that S mode turns off the sensors, and RTH relies on having the collision avoidance sensors on while the Mavic is flying back to you. While it's in RTH, the Mavic is essentially 'autonomous' - flying itself - so putting itself into S mode is like blinding itself.

 

[scro]

I think that S mode turns off the sensors, and RTH relies on having the collision avoidance sensors on while the Mavic is flying back to you. While it's in RTH, the Mavic is essentially 'autonomous' - flying itself - so putting itself into S mode is like blinding itself.

This is true on some of the larger Mavics, where OA sensors are deactivated in S-mode. The Mini has no OA sensors (other than the vision sensing pair that face downwards) so has nothing to deactivate.

The mode display in the upper left corner will probably continue to show it is in S-mode during RTH if that was the mode you were using prior to activating RTH. However, that just means it is in S-mode for when the pilot is controlling the aircraft. In RTH the firmware controls the aircraft and it uses it's own RTH mode tilt and speed limits (which happen to be the same as P-mode limits)

 

[DrizzyDrones]

But when rth is active if you push full forward the speed definitely goes faster than p mode ?

 

[scro]

But when rth is active if you push full forward the speed definitely goes faster than p mode ?

Not sure if you're asking or telling us?

I've not used RTH enough to know for sure, but others certainly report seeing higher speeds when pushing the sticks during RTH compared to just letting it fly itself home.

 

[slup]

But when rth is active if you push full forward the speed definitely goes faster than p mode ?

Not sure if you're asking or telling us?

I've not used RTH enough to know for sure, but others certainly report seeing higher speeds when pushing the sticks during RTH compared to just letting it fly itself home.

It's all most probably in the full version manual ... this for my MA1 for instance. Note that it's also possible to manually stop RTH ascends.

 

[scro]

the MM manual contains something very similar, stating that you can control speed/yaw and height manually during RTH and I expect it is the same as the MA. What it doesn't detail is what speeds can be achieved with manual control "overlaid" on the RTH autopilot maneuver.

(ps, the linked image isn't appearing correctly for me)
Edit: now it is. Exactly the same as for the MM

 

[TerryToast]

RTH should have an toggle button saying
- Normal mode; or
- Sports mode

Assuming RTH Height is set correctly, you don’t need obstacle avoidance for RTH. So Sports Mode would be better and reduce the number of “flyaways”.

 

[scro]

RTH should have an toggle button saying
- Normal mode; or
- Sports mode

Assuming RTH Height is set correctly, you don’t need obstacle avoidance for RTH. So Sports Mode would be better and reduce the number of “flyaways”.

Remember the MM doesn't have obstacle avoidance in any mode. Just letting RTH mode use the full 30deg tilt if needed would do the trick - this gives the MM a useful increase in max air speed. The extra ground speed offered by sports mode isn't vital - unless you're impatient.

You can, of course, apply some manual stick input during RTH to access the full 30deg tilt, provided you still have a connection to the drone.