Landing Mavic pro on boat netting with propeller guards

[chickianwing]

Hi,

I am experimenting with Mavic Pro on a boat using a wide-flat netting and having DJI propeller guards fitted to Mavic.

The proof of concept was to land and launch the Mavic from the boat netting with the downward sensors switched off. The netting helps to cushion off the roll, heave and pitch effect of a drifting boat while trying to land the Mavic and the guard helps to prevent the netting from contacting the propeller itself.

I found that the following challenges still remain unresolved and i would appreciate some advice from the community that can add on to this proof of concept constructively:

1) the Mavic was unable to switch off despite multiple attempts of emergency shut off while it is very close to the netting
2) the propeller motors refuses to cut off even after the Mavic had already touched the netting and as a result the mavic was still attempting to fly off - which seems fairly dangerous as the propeller guards may have caught on to the netting.

I have read in the forum that using the sports mode would really help at sea because it can function better under higher wind conditions and the remote controls are more responsive. But having said that, the landing issue with the net and propeller guard combination needs to be improved for better landing experience.

Appreciate the comments and views here

 

[username1234]

Why don't you launch from your hand?

 

[rob2000gt]

Launch and land by hand

 

[chickianwing]

Why don't you launch from your hand?

I think from a risk management perspective, I want to eliminate the need for direct contact with the drone during launch and landing.

 

[chickianwing]

Launch and land by hand

not what i am looking at.

 

[Plawa]

tons of threads on this topic already here, do your research first... and learn how to catch it, it's the best option.

 

[Simmo]

tons of threads on this topic already here, do your research first... and learn how to catch it, it's the best option.

I found one other thread, and no real answers there either. The OP doesn't want to Hand launch, or Hand land. He wants to use a net? ?
OP, you have precision landing turned off too?
When you tried CSC were you trying to fly with the boat? (ie moving?)

 

[Gilly]

In my oppinion motors wont shut down as the IMU is sensing the movement of the boat as movement of the aircraft.

Unless the boat is very still your going to struggle. Hand landing works as your hand acts as a gimbal to allow the IMU to stabilize long enough to shut down.

If you must land it on a boat, Hand is the way to go. Maybe buy some handles to affix to the legs to negate the risk of contact with the blades. or use prop cages rather than just guards.

 

[chickianwing]

tons of threads on this topic already here, do your research first... and learn how to catch it, it's the best option.

Like I have mentioned, this is a proof of concept. I have no interest in getting my hands cut by drone. peace

 

[chickianwing]

In my oppinion motors wont shut down as the IMU is sensing the movement of the boat as movement of the aircraft.

Unless the boat is very still your going to struggle. Hand landing works as your hand acts as a gimbal to allow the IMU to stabilize long enough to shut down.

If you must land it on a boat, Hand is the way to go. Maybe buy some handles to affix to the legs to negate the risk of contact with the blades. or use prop cages rather than just guards.

Thanks for sharing. But shouldnt the emergency shut down suppose to work? because it is suppose to work in mid flight according to the user manual. But it seems like it does not respond the way it should.

 

[Gilly]

If your referring to the CSC command it needs to be activated. But no it wouldn't help...If you CSC whilst the Mav is on the ground it will do a back-flip and end up in disaster.

 

[Lake_Flyer]

Catching your Mavic by hand is by far the safest option, just switch off landing protection and add 10% extra margin on your low battery warning, bring it in at 40%. You must always take extra time for landing because you want a moment when the boat doesn't rock too much, and a low battery procedure is the last thing you want.

Prop guards over water is not good. They give extra drag. Over water there's usually more wind. Landing in a net doesn't work because the mavis doesn't sense it's on the ground and will continue to try to hover.

 

[rob2000gt]

I would never take a chance landing on something that would touch the propellers ever even grass but thats my though as precise as the mavic is I would make a really nice landing pad instead of a net. Good luck with this.

 

[Simmo]

 

[Lake_Flyer]

On calm water you could even use floats (many make them from a piece of pool noodle) and land close to the boat. That's what I do often. But catching is very easy and can be done safely with a Mavic. You should practice that on land first. After a few tries you know it's easy and safe. Just make sure Landing Protection is switched to off in the Go app.

 

[Simmo]

Within the various versions of DJI consumer drones, DJI created the Combination Stick Command (CSC) to both start and stop the motors. Initially, this was the only way to control the motors:

A problem was realized with agressive flight, where the CSC could be initiated accidentially, resulting in the aircraft crashing/falling out of the air due to accidential motor stoppage. With the evolution of the GO/GO4 app, DJI introduced the landing method of motor shutdown by simply holding the throttle down, after the aircraft has landed, for three seconds, and the motors shutdown. This has become the standard way of shutting down the motors on landing. But the inflight CSC problem remained a possiblity.

So with the P4, DJI introduced an alternative control combination for emergency motor shutdown. But long time users of DJI products didn't like this methodology. So with the Mavic, DJI programmed additional intelligence into the flight controller that allows the pilot to choose how the motors can be stopped in mid-flight....

That's what you are referring to in your screenshot. Since stopping the motors in mid--flight WILL cause the aircraft to crash, if you select "For use in emergencies only", then the Mavic motors can only be stopped in mid-flight when the Mavic flight controller detects a CRITICAL error. If you select "CSC Maneuver", then you (the pilot) can deliberately stop the motors or accidently stop the motors in mid-filght with a simple CSC and it will stop the motors...

So if you want to fly agressively and not worry about accidential CSC commands, then select "For use in emergencies only", and the GO4 app will protect you. If your an old-timer and like full control as the pilot-in-command, then select "CSC Maneuver" and be carefull to not ever push the sticks to the CSC position while in flight.....

 

[Lake_Flyer]

A problem was realized with agressive flight, where the CSC could be initiated accidentially

Very good point Simmo,

The aggressive control commands resulting in a CSC will mostly occur when newbies are flying beyond VLOS and lose video feed. They often start stirring the sticks in panic, without seeing or knowing how their bird reacts. All the so called 'smart' decisions, later build into the firmware and taking a lot of joy out of the flying, are mainly caused by stupidness by these people claiming warranty.

 

[shark4985]

I would start by checking the CSC settings, it should shut it down if you have the in flight shutdown allowed. I like your idea and am interested to see how it goes. Post some pics if you build a prototype. I have launched and landed from a boat many times, all by hand but only for lack of a better option. Until you have done it, it sounds easy. The boat always seems to move more when you are trying to land your MP. A few key points for anyone trying this for the first time:
-Keep in mind the relative motions of the boat/ MP. Even if you think the boat is not moving, it is unless you are tied to a dock. As soon as you launch the MP, it will hold GPS position, and the boat can very quickly move into the MP. Always launch from the trailing side of the boat based on which way it is moving so the boat moves away from the MP.
-Look up before you launch. The first instinct is to gain altitude, make sure you are clear of outriggers, fishing lines, rods, and any structure of the boat.
-It takes two to land. I have done it by myself, but it took several attempts. Again, those calm, 1 ft seas mean cyclic "altitude" changes relative to the boat at varying frequency while you are trying to not lose a finger or a drone. Almost took a prop to the face. Have someone catch while you shut it down.
-Check your setting for signal loss, and smart RTH. If you don't, the MP will turn around and fly back to where you took off from when the battery gets to about 50% or you lose signal.
-Give yourself significantly more margin on your battery for landing.
-Go on youtube and search for boat drone launches/ landings and learn from others who have failed before you.

 

[chickianwing]

On calm water you could even use floats (many make them from a piece of pool noodle) and land close to the boat. That's what I do often. But catching is very easy and can be done safely with a Mavic. You should practice that on land first. After a few tries you know it's easy and safe. Just make sure Landing Protection is switched to off in the Go app.

Unfortunately i cannot replicate what happens on land while at sea because the conditions are really different where the wind could be suddenly strong, the wake/swell could also rock the boat pretty badly. in such operating environment, its really unsafe for the pilot to manually catch the drone. As for your suggestion to use float, I would prefer that the mavic be landing on dry surface as I doubt Mavic is able to withstand the harsh marine environment not to mention letting it land on surface of the sea will only worsen its lifespan.

 

[chickianwing]

Within the various versions of DJI consumer drones, DJI created the Combination Stick Command (CSC) to both start and stop the motors. Initially, this was the only way to control the motors:

A problem was realized with agressive flight, where the CSC could be initiated accidentially, resulting in the aircraft crashing/falling out of the air due to accidential motor stoppage. With the evolution of the GO/GO4 app, DJI introduced the landing method of motor shutdown by simply holding the throttle down, after the aircraft has landed, for three seconds, and the motors shutdown. This has become the standard way of shutting down the motors on landing. But the inflight CSC problem remained a possiblity.

So with the P4, DJI introduced an alternative control combination for emergency motor shutdown. But long time users of DJI products didn't like this methodology. So with the Mavic, DJI programmed additional intelligence into the flight controller that allows the pilot to choose how the motors can be stopped in mid-flight....

That's what you are referring to in your screenshot. Since stopping the motors in mid--flight WILL cause the aircraft to crash, if you select "For use in emergencies only", then the Mavic motors can only be stopped in mid-flight when the Mavic flight controller detects a CRITICAL error. If you select "CSC Maneuver", then you (the pilot) can deliberately stop the motors or accidently stop the motors in mid-filght with a simple CSC and it will stop the motors...

So if you want to fly agressively and not worry about accidential CSC commands, then select "For use in emergencies only", and the GO4 app will protect you. If your an old-timer and like full control as the pilot-in-command, then select "CSC Maneuver" and be carefull to not ever push the sticks to the CSC position while in flight.....

Good point, I may have been doing it all wrong as I thought when the mavic landed on the netting and i execute the CSC it will force the motor to stop. Thereafter, I tried to use only the left stick to land the drone (it didnt shut off either) as the sensors were off and the drone still believes that it has not reached the landing surface. So what I did was, I use the in app auto landing button on the left side of the screen (swipe right to confirm) and the mavic actually stopped its motor while its already on the net safely (before that it was just running and the drone was trying to hover away due to some high winds).

Thanks for the info and i will take into account during the trial again soon