RTH maintain speed or power output

[Fastaschit]

I just picked up one of these on sale and have a question regarding RTH I need to know considering the light weight of this little one.

If you are in rth mode and it encounters an unexpected headwind, will the MM increase power output in effort to maintain RTH speed or does it maintain power output over speed resulting in it slowing?

 

[VenomXts]

I just picked up one of these on sale and have a question regarding RTH I need to know considering the light weight of this little one.

If you are in rth mode and it encounters an unexpected headwind, will the MM increase power output in effort to maintain RTH speed or does it maintain power output over speed resulting in it slowing?

RTH goes as fast as it can if you hit a wind faster pushing back you will be in trouble.

 

[scro]

RTH speed is limited to a maximum of 8m/s. If it is fighting a headwind it will be slower than this. It's worth understanding this well as many people have lost drones due to setting a high RTH altitude. On activating RTH the drone has flown up high into stronger winds and tried to fly home while being overcome by the strong wind and blown many miles away.

The drone can go up to 13m/s in sports mode, and hence it can fight against a stronger headwind. If you're flying in windy conditions a good tip to assist RTH is to enable sports mode and push the "forward" stick all the way forwards - this "pushes" the drone to go faster than the default maximum of 8m/s. You can overlay some manual controls input while the drone is automatically returing to home. For example you can get the drone to spin around on itself while it flies in a straight line back to the home point.

 

[Deleted member 103366]

Entirely automated RTH is not the best method to fight wind for two reasons, both of which Scro mentions.
A fixed height which quite often people set excessively high and which, in wind, lifts the drone into an area where the winds are most likely stronger.
Limited speeds.
The big advantage of RTH is that it initially points the drone's nose towards home, a direction which could then be used to manually fly the drone in a rough path towards home. I am not certain if a mini keeps its nose pointed at the home point during RTH

Whilst I have not had my mini caught in serious winds in a blow away threatening situation I have flown it faster than the automated speed by switching to S mode and putting the elevator to the forward, or backwards, limit. From memory you can also manually reduce the height during RTH. You can also stop an RTH climb to excessive height by, once the drone is over 20m above the home. point, moving the throttle stick (page 14 of the manual).

I can not say from personal experience whether, in order to maintain a ground speed of 8m/s, a mini can fly faster than an airspeed of 8m/s during entirely automated RTH but I have had my mini RTH in an almost hover position when it had been flown up wind in strongish wind before the RTH was initiated, it was quite funny to see. At some point I may test the up wind RTH capabilities but that would need a steady 'strong' wind in the correct direction to allow me flights over an open field etc.

 

[Fastaschit]

Thanks. That sort of answered what I wanted to know at the same time some very good info you guys provided.

What I meant in my question was you know how we can hover a drone in front of us and if we grab the landing gear and pull it from its locked position it will rev the motors to keep its pos. If the MM is returning home and encounters headwind would it rev the motors any and apply a more aggressive pitch in effort to maintain its rth speed or would it simply slow down?

Its sounds like it will slow. Personally I very rarely ever use a RTH feature on any of my DJI and if so it would be at lowest altitude i could get away with. I have an old Hubsan H501s that I pull out every once in a while that I do use RTH a good bit only because I take it to secluded areas and fly marathon distances and sometimes until disconnect. RTH would used just to get it back enough to reconnect. It would always return at 6 m/s and will attempt to keep that speed even if a head wind came from nowhere. I always follow the rule of flying against the wind if there is any.

I doubt a RTH function on my MM will get much use at all but I was curious about my question because I had read all the reports people having issue with wind returning home. 99% is likely user error or poor decisions.

I'll be glad to get some testing done with the MM. Its either been too windy here or raining lately.

Its good to know some controls can be used if in rth too.

Thanks again for some great info

 

[Deleted member 103366]

I suppose one 'safe' way to test this might be to go out to a safe place on a 'windy' day, take off and, using the map, reset the home point a fair distance upwind then trigger the RTH and leave it running long enough to see the results. Then cancel the RTH before it lands and reset the home point to the controller's position and bring it back. I can't do this because for me that flight would be over water and I'd rather not push my luck that far.
Alternatively fly it on a LONG tether, this is something I might try at some point. I have a nylon? sewing thread that works as a tether though its first and only use ended badly as it snagged a bush and dragged the mini down, fortunately there was no damage but such an experiment would be in an open field with just grass etc.

 

[Meta4]

RTH speed is limited to a maximum of 8m/s. If it is fighting a headwind it will be slower than this.

Until recently, all DJI drones worked this way.
But the Air 2 was released with a trick that allowed it to tilt more and fly faster (up to SPort Mode speed) in RTH when necessary to counter a headwind.

If you're flying in windy conditions a good tip to assist RTH is to enable sports mode and push the "forward" stick all the way forwards

If you enable Sport Mode, you cancel RTH Mode.