Hover or RTH upon RC signal loss?

[kem]

Hello Pilots,

I have recently seen a post where somebody's drone just landed into a river/lake because the RC signal was lost and the drone was within no RTH distance.

I am wondering if should chose hover over RTH.

In a similar case I would have enough time (25mins?) to do something.

But let's assume that the RC signal is lost due to the distance. If my understanding is correct, the drone will try to com back to the home point once the battery in only enough to RTH. In the mean time, I could try to get closer and pick the signal up.

What is your settings?

Br,
Istvan

 

[msinger]

But let's assume that the RC signal is lost due to the distance. If my understanding is correct, the drone will try to com back to the home point once the battery in only enough to RTH

If you have that setting set to hover, the drone will never attempt to fly back to the home point. It'll hover at the point where the remote controller signal was lost until either the signal reconnects or the battery reaches the critically low level. At the critically low level, the drone will auto land at its current location.

 

[Mossiback]

...But let's assume that the RC signal is lost due to the distance. If my understanding is correct, the drone will try to com back to the home point once the battery in only enough to RTH...

For the MP, if the connection to the RC is lost for more than three seconds it will initiate RTH. In your scenario, because the connection was lost due to distance it would be best to have it set to return . An automatic return to home would decrease the distance which should re-establish the connection. Once you have control again you can cancel RTH if you wish.

 

[Mossiback]

To answer your question, the only time I have RTH set to hover is if I am flying under an obstacle or indoors.

 

[Former Member]

For the MP, if the connection to the RC is lost for more than three seconds it will initiate RTH. In your scenario, because the connection was lost due to distance it would be best to have it set to return . An automatic return to home would decrease the distance which should re-establish the connection. Once you have control again you can cancel RTH if you wish.

I agree with @Mossiback

Best thing is to let it RTH and try to find its way back best it can. It will draw a straight line between where it is and the home point and follow that route at flank speed. Within a short time, you might very well regain signal, then you can switch to sport mode, and get it back faster, in a steady descent.

RTH will make it return home at your predetermined altitude, but thats not always the best way to get it back and on the ground the fastest way possible. Here is what I do, if that ever happens:

• Hit the RTH button if you have intermittent signal. Hopefully the drone gets the command.
• If it does not get the command, and you have RTH, not "hover" set as the default, then it will start to come back.
• Once the drone gets back into range, I dont let it return at a high altitude. I set up a linear glide path descent , which is a 45° angle between where the drone is and the most direct path back to the home point on the ground.
• That will help it increase speed, and shorten the distance back.
• When I get near to the home point, if I think it will make it back, I make the glide slope more shallow and gradual, and then set it down slowly.
• If I dont think it will make it back, I gimbal straight down, look for a clear LZ, and land it, even if I still have 17 or 18% battery left. If you let it autoland at 15% critical battery, you risk it landing in an undesirable spot. Best to pick your LZ along the way back, land it and then either run, drive, or paddle your way to the drone.

Dont ask me how I know how to do all of this.

 

[Cloudnine]

before i get dumped on i am not suggesting/recommending my settings but I replaced RTH with hover in the settings in my controller for the go forward, i've testing RTH and i don't like how it performs, i've tested it in a thoughtful, controlled manner and it didn't meet my expectations and for how i fly my drone, some may consider boring, Im convinced it's the right choice.

what i like most in when people say "it tries to retrace it's steps..." execution of the subroutine doesn't 'try' it does or it doesn't and your points of potential failure are in environment, technological, mechanical and data and all those are at play when executing RTH, hover mitigates the risk. sure, distance is a risk but it's not attempting to do anything so not relying on at least 1 or even 2 of the aforementioned points of failure.

in this case, you're right in terms of what plausibly would happen; instead of it trying to execute a move it would just stay put and based on what was said in terms of battery life there would be 20ish minutes to regain control, and remember: distance isn’t ALWAYS the factor in losing control, simply moving your body/controller would give you reconnectivity, again this COULD happen if it was set to hover. hover isn't going to try to execute a move that could go awry.

 

[CanadaDrone]

Depends where you are. For example if you were flying trough a tunnel, indoors, or under tree canopies, you would normally want it to hover instead of RTH. Outdoors unobstructed, RTH is usually preferred because you will more than likely be able to regain control of the drone very shortly after it initiates RTH, assuming a signal loss was the reason for the RTH command.

I also keep one of my custom buttons set to quickly point the gimbal 90 degrees down in case I ever need to look for an emergency landing spot, I can do so very quickly. It's handy when taking photos too.

 

[JoostGT3]

Like mossiback, I have it set to RTH, EXCEPT in case I suspect that that will pose a problem. For example, one day I was planning on flying above a local river, passing under a bridge. My fear was that all the metal in the bridge might intterrupt the signal, initiate an RTH and would cause the drone to ascend into the underside of the bridge. So in that case, I set it to hover, also because I knew I would be close enough to run to it and recover the connection.

Low battery RTH saved my MP once when I was flying over a local lake and didn’t pay attention to the wind; at a certain moment it triggered a low battery RTH, but it was battling fierce headwind.... it only just made it back to shore with a few feet to spare!

 

[Former Member]

Good point in post #7 above. When I teach people how to fly drones, I never let where they are standing be the home point. I always set the drone in front of us around 15-20' and spool the motors up there. The home point will be clear of obstacles and obstructions, and be a safe place for the drone to land no matter what.

 

[Meta4]

I am wondering if should chose hover over RTH.

There is a really good reason that DJI have made Hover <<correction - that should be RTH>> the default option for Loss of Signal.
In almost all flying, it's the only option that makes sense.
It's pointless to leave your drone hovering and out of contact when the ability to come back is built-in.
Only change it if you have a particular reason to because of the flying environment.

 

[jwt873]

My thoughts are... What if the controller failed? Or the receiver in the drone died.

In that case you would never be able to re-establish contact with the craft. If you're set to hover on loss of signal, you would have to go to where it was hovering and wait until the battery wore down so you could recover it when it landed.

In this case, hopefully its hovering somewhere you can get to easily and not somewhere like over the middle of a lake.

 

[gnirtS]

Hover is useful when flying from a boat. If something happens and it RTHs and for some reason you cant reconnect then it'll land where there boat was not where the boat is.
At least with hover you can move the boat to the drone to get contact reetablished or worst case, get underneath it.

 

[Thomas B]

Use RTH. Be sure to check the height in RTH, to be sure it is above any obstacles

 

[kilomikebravo]

I never let where they are standing be the home point.

I do perzactly the same thing, Rob. Well clear, lots of satellites, Home Point recorded.

With regard to the OP, I can see his logic and if he is comfortable with that, I say go for it.

 

[tcope]

As gnerts mentioned, Hover is used also when the flier is moving large distances. You don't want to drive, run, bike, boat, etc. something like a mile away from the Homepoint and then have the drone (try) and return to that point if the signal is lost.

DJI _really_ needs to add a pop up window for this change choice whenever someone switches to Active Track mode.

 

[THE WOMBLE]

• Once the drone gets back into range, I don't let it return at a high altitude. I set up a linear glide path descent , which is a 45° angle between where the drone is and the most direct path back to the home point on the ground.
• That will help it increase speed, and shorten the distance back.
• When I get near to the home point, if I think it will make it back, I make the glide slope more shallow and gradual, and then set it down slowly.

I am not going to ask how you know all this but ask how you set a linear glide path descent of 45º.

 

[Lapeer20m]

I had an issue with this recently, while flying an m-210 with a $12k flir camera attached.

Matrice was about 30 feet away, over a pond, and suddenly The rc announces “landing”. Matrice ignored stick inputs and landed right there. The done suffered a hardware failure that made it think it was disconnected, even though the rc still had telemetry and video. Fortunately, it was winter in Michigan and it landed safely on the ice.

I’ve flown DJI drones about 500 miles and countless hours but I did not immediately understand why Matrice landed right there without rth.

Needless to say, there is an update to our sog that now requires rhe home point be at least 20 meters from a body of water.

 

[kilomikebravo]

I am not going to ask how you know all this but ask how you set a linear glide path descent of 45º.

TW: I meant to ask Rob the same question but it wouldn't surprise me if his eyes are protractor-calibrated.

 

[MAvic_South_Oz]

I am not going to ask how you know all this but ask how you set a linear glide path descent of 45º.

You can’t actually set it (unless there is some special backdoor way to programme it).
I do this sometimes when I let RTH function do its thing (or part thing).
If the terrain is suitable and whatever RTH height you had set is too high, simply lowering the drone with some left stick down will gradually bring it down more directly to home point, not on a perfect 45 degree angle, but think that was just a figurative indication given.

 

[Former Member]

I am not going to ask how you know all this but ask how you set a linear glide path descent of 45º.

Good question. You cant set it in the app, you have to calculate it manually. From my years of pattern work in full scale airplanes, I am able to visualize the landing point, and where I am at, and can draw a straight line in my head. With a drone, you can manually control the descent to create a nice glide slope from altitude to landing. You can make it gradual or steep as you like, but I find gradual works best, and its fun to try and calculate it just right so that the drone is at the home point and ready to land at 10-20' above the home point. Then just a vertical descent.

Sounds alot more complicated than it really is.