Testing how the M2P does RTH after disconnection

[boblui]

As described in the user manual. The drone does not fly straight back to the home point after losing connection with the RC but follows the original flight path in the reverse direction. Can be useful in some situations.

In the test, the radio connection was broken intentionally by putting the controller in a metal can. The lid was open shortly after the craft started descending over the home point

 

[skunky1]

Does this mean that it potentially avoids any obstacles as flew that route and the craft merely returns via the safe route?

Other question is have is if you set RTH altitude to 60m but was flying 80m when disconnecting does it stay at 80m or go down ?

 

[zeusfl]

The aircraft will return to the home point straight unless has any obstacle when returning what will try to avoid. If you set the RTH altitude for example 60M and you are flying at 80 meters and the RTH is activate by any reason, will stay at 80 Meters and will return to home. If is set to 60 RTH and you are below that, the aircraft will gain altitude up to the 60M set then will return to home.

Something we need to mention. If you are less than 20 meters from distance from the home point and you activate RTH, the aircraft will land instead to return to home by defect. You need to be farther than 20 meters in distance order to RTH works.

All this is true as long as the craft has 10-15 satellites signal in order to RTH.

 

[zeusfl]

Here is more information if you want to read.

DJI Guides - DJI Store (United States)

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store.dji.com

 

[boblui]

Does this mean that it potentially avoids any obstacles as flew that route and the craft merely returns via the safe route?

Yes.

Other question is have is if you set RTH altitude to 60m but was flying 80m when disconnecting does it stay at 80m or go down ?

It will stay at 80m

 

[boblui]

The aircraft will return to the home point straight unless has any obstacle when returning what will try to avoid.

True only if RTH is activated by the pilot. In case of fail-safe RTH. It will not fly a straight line back to the home point as demonstrated by the footage. Here is what the user instruction says :

 

[skunky1]

True only if RTH is activated by the pilot. In case of fail-safe RTH. It will not fly a straight line back to the home point as demonstrated by the footage. Here is what the user instruction says :

View attachment 113619

What if there is a disconnection during a waypoint mission. Does it retrace the mission steps ?

 

[zeusfl]

I see. That is new for me. But will go back only for 60 seconds. If in 60 seconds does not have control signal will go to home straight. I will like to test this by my self.

Thank you for the information. This apply only in fail safe cases.

 

[Martysticks]

Great review, but I would never have tried it over that terrain My luck it would land in the water or muck

 

[Not A Speck Of Cereal]

In the test, the radio connection was broken intentionally by putting the controller in a metal can.

Why not just turn the controller off?

 

[boblui]

Why not just turn the controller off?

I have tried that and the drone always RTH in a straight line. I think the RC issued a RTH command to the drone prior to turning off.

 

[Not A Speck Of Cereal]

I have tried that and the drone always RTH in a straight line. I think the RC issued a RTH command to the drone prior to turning off.

I wonder why DJI would design the RTH to go straight-line back to the recorded HP and not the normal obstacle avoidance in such a case -- that doesn't make sense to me.

 

[Thomas B]

I wonder why DJI would design the RTH to go straight-line back to the recorded HP and not the normal obstacle avoidance in such a case -- that doesn't make sense to me.

Shortest route so less battery needed if signal not reacquired in the initial short retrace flying.

 

[DanMan32]

I wonder why DJI would design the RTH to go straight-line back to the recorded HP and not the normal obstacle avoidance in such a case -- that doesn't make sense to me.

Straight line RTH will still have obstacle avoidance.

You may be confusing signal loss path retrace for 60 seconds in hopes to regain signal from where it's been within the last 60 seconds with signal.

Granted a shutdown of RC should simulate an unexpected signal loss and so a retrace rather than straight line RTH as if user initiated.

 

[boblui]

..... a shutdown of RC should simulate an unexpected signal loss and so a retrace rather than straight line RTH as if user initiated.

I think shutting down the RC is like shutting down a computer. The computer will close all tasks that are still running before turning the power off. I will not be surprised if the RC issues a RTH command to the drone as if user initiated before powering down. I will check if the flight log gives any indications

 

[Not A Speck Of Cereal]

I think shutting down the RC is like shutting down a computer. The computer will close all tasks that are still running before turning the power off. I will not be surprised if the RC issues a RTH command to the drone as if user initiated before powering down. I will check if the flight log gives any indications

Turning off the remote is not like a "immediately off" power switch, but you are just powering down the remote, not the aircraft.

If I fly a circular path around a building and lose signal, I would NOT want the aircraft to come back in a straight line. I would want it to re-trace steps. The same should happen if the remote loses power for any reason.

Chris

 

[Meta4]

I have tried that and the drone always RTH in a straight line. I think the RC issued a RTH command to the drone prior to turning off.

That sounds very unlikely.
Have you only observed this one time?

 

[boblui]

That sounds very unlikely.
Have you only observed this one time?

Multiple times and very consistent. This is one of the flight. The RC was turned back on before the drone landed.

 

[Meta4]

Multiple times and very consistent. This is one of the flight. The RC was turned back on before the drone landed.

That doesn't show you turning off the controller or losing signal at all.
There is full signal for the whole flight.

At 8:57.5 the drone is in P-GPS mode with signal
At 8:57.6 it is in RTH and there is still full signal.
For Failsafe RTH there has to be a loss of signal for a certain time period.
If you had turned off the controller (and turned it on later), there would be a gap in the data.
This does not support what you are suggesting.
Looking at the data, it just looks like you pressed the RTH button.

 

[boblui]

That doesn't show you turning off the controller or losing signal at all.

Oops ! wrong file attached.

In that flight I tried for the first time to put the RC into a metal can but failed to break the radio connection. Subsequently I downgraded the drone from FCC to CE mode, flew the drone further away, put the metal can inside my car and close the car door to force disconnection.

This is the flight in which the RC was turned off and then back on :