10 days on a live on board vessel, Phantom 4 IMU got sea sick ...LOL

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Hi All,

Just want to share some things I learnt ...
I am not a seasoned Phantom 4 user, so apology if any of the info sound stupid.

Anyway, due to a messed up departure flight schedule for this live on board dive trip, I did not have time to calibrate the IMU on solid non moving ground upon landing.

I have planned to first calibrate the IMU and compass, 1 night before before going on board , which is at the hotel. But already loosing 1 day due to the airline not informing me that the flight was re-scheduled and took off 5 hours earlier !!.... I then flew the next day and scrap the hotel stay and went direct to the boat.

The sea was not friendly for 8 days out of the 10 days trip.
I only touch land/beach twice during this trip and P4 was not yet "sea sick" then.
Each passing day the IMU gets more sea-sick as the weather worsen day 3 and thereafter... ha ha ha.
It gives me lots of warning when I wanted to take off.

So i did my best to calibrate the IMU while at a protected anchoring, but the boat was rolling a bit.
What later happened was, the camera horizon went banana ...LOL.
So got to adjust gimbal roll manually, but its flat horizon recovery is very slow when P4 fly around and I stop to take photos.

While at it, I experimented something crazy.
I calibrated the gimbal while on GPS assist hoovering.... ha ha ha.
Then the gimbal went limp... ha ha ha.
So calibrated again the gimbal while at another protected anchoring, vessel still minor rolling, no choice. Use use gimbal manual roll adjustment after that... otherwise flat horizon is impossible as is, during a flight.

Usually I take off and land my Phantom 4 on ATTI ( manual ) if I fly from land and only use P-GPS assist when it reaches safe height. This trip I was so occupied with the diving, I forgot to use ATTI when taking off and landing.;)

The P4 nearly crashed into the vessel in one location where the current was strong and the vessel at anchor was swinging wild up to 40 meters. Basically its was a "moving ground" as take off and landing platform.
Since the vessel is big and I was not looking at a reference horizon like an island, I forgot that it was swinging ( changing position ), I only assumed it rolled as a roll, one can feel it easy. So my visual perception was the P4 not maintaining proper X hoovering position when comes landing time...:D . Must be the nitrogen narcosis* effect on my part ( * diver's joke ). There then after that landing, I remembered it was not on ATTI , but P-GPS.

The current.... this is the worst anchor point of all.
Current caused vessel swinging v1.JPG




The vessel swing, as seen from a GPS logger
Current caused vessel swinging v2.JPG



The vessel is a traditional type motorized sailing vessel with wide beam.
It has lots of wires/ropes above P4 take off and landing zone.
Taking off is easier, landing is slower as the wind was always blowing at 10 knots or more, so I gave the P4 a few seconds hoovering at 30cm above take off deck, otherwise it will flip due to the wind... if immediate landing I do. I don't do hand catch as I planned. Enough space to do "ground" landing and take off.
I have safe space approx 3/4 a length of a common 4 door sedan to land and take off from.
The 3 seconds hoovering prior to landing is the uncomfortable part every time the vessel was swinging, even if P4 in ATTI mode, let alone a P mode. So the P4 was "like" a drunken flyer from a pilot perspective. In this swinging LZ scenario, a hand catch maybe a better alternative to those more seasoned flyer.

The LZ size.
Landing Zone.JPG



A P4 motor shutdown takes 3 seconds after touch down, with left stick at 6 o'clock ( my controller setting ).
When the P4 senses the vessel/boat roll by a swell from the beam/side, which means it changes altitude above sea level equal to wave height, sometime the P4 mistaken the condition as "not-yet-landed".
So the P4 will throttle up trying to correct its horizon...LOL....even thought it already landed.

I did not use the bottom positioning sensors, as on a moving landing zone, it may read and re-act wrong.
Its algorithm surely detected drone as stationary, it may then get confused if the bottom vision sensors seeing the floor moving. Should experiment this someday with a mat and I move the mat around while P4 stationary and using bottom sensor.

I also do not use the forward vision sensors as it seems to mess up with my landing and take off if the landing zone actually move and has lots of guard rails up to 100cm high. Some of the take off before I realized I needed to use ATTI and forward vision sensor was still active, I do notice like a very laggy response of the P4 when I throttled the P4 to go to open water but needed to first pass the vessel railings.
I think it was confused ... :)

Of all the landings I did, only once the P4 actually went 45 degrees knocked out, aka resting on its rear motor pods... ha ha ha, but motor already off, so props all good. This is one thing I do not like about X body shape drone, no matter where the wind direction is from, it can get knocked out easier due to wind when landing , even after motor already powered down stick wise , compared to H body shape which is more stable when landing upwind. In strong wind landing, my 3DR Solo somehow is more "friendly". I guess a Mavic Pro would be more friendly too as it is H shape and very low profile, so center of gravity is very low and stable.

All my landings are nearly a 45 degrees knocked out.... no choice if in the wind ...its always like that.


Any other issues ?
- Yes. In 1 rare occasion, I lost a video feed totally when it was too small to see visually the P4 against a white cloudy sky.

Lucky the telemetry data with that P4 icon and heading and home Icon is still transmitting. I dare not press home or do auto landing, no way on a swinging landing platform with sail rigging wires obstruction .... what if I cant abort the auto landing ?. I dont know what actually happened. Vessel radar was off, vessel VHF was not transmitting and the area has no wifi interference, its a very remote island area. Only happened once though...wheewww lucky me.

I do wish Phantom 4 get Tripod mode like Mavic Pro or Phantom 4 Pro, or Snail mode like my 3DR Solo.
My poor flight hours made me unable to do constant slow shots.

I don't use the automated flight/shot modes on this trip as I am still learning to know the P4 manually.
I have to improve my manual flying skill.

Its just that I am living in a very crowded city and I respect other people's privacy, today I do not fly my drones around my neighbourhood for practice. Too much 2.4Ghz wifi router around is also a risk. Loosing a drone $$ wise its okey, but if it falls one someone face is something I fear most.

I need to drive at least 4+ hours to get to anywhere with lowest population zone & with least houses, to practice flying. My city in the world's most populated island. Java - Wikipedia .
3/4 the size of the State of California, but with 145 million people, or 44% of entire USA population of 2016.
With annoying drone accidents rate on the rise, I do not want to add one to the statistic.
So now, I only fly in remote areas....and sadly that only occurs once every few months.

When I had my Phantom 1 eons ago, I dare to fly around my home neighbourhood. But 100 meters radius only as there was no video feed and the tall buildings around was not as many as today. Not to mention the quantity of new cell phone transmitter towers of today. I can't even tell which is P1 the azz and which is the head from a distance, back then...LOL. So flying far as in 100+ meters won't ever happen.
Drone video feed does give you a false sense of security, aside from it being useful and important.

Anyway, this is the experience report from someone not experienced:p

END
 
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Now some images...
Its fun to look at Google Earth, but since it is flat view quality for most area, an equivalent angled aerial photo does looks different

.
Kruo Island - R4.JPG


.
Kruo Island - GE.JPG


.
Wayag Island - looking South - R4.JPG

.
Wayag Island - looking South - GE.JPG



Sorry, IMU already got sea sick here, so horizon kinda off :)
Yangefo Island - looking east - R4.JPG


.
Yangefo Island - looking east - GE.JPG


I don't have any filters on the P4, its all as-is.

end
 
Thanks for sharing your adventure, I enjoyed the info of the P4 on a rolling ship. Nice pics!
 
Anyway, due to a messed up departure flight schedule for this live on board dive trip, I did not have time to calibrate the IMU on solid non moving ground upon landing
... Each passing day the IMU gets more sea-sick as the weather worsen day 3 and thereafter...
... So i did my best to calibrate the IMU while at a protected anchoring, but the boat was rolling a bit.
There should have been no need to recalibrate your compass or IMU.
Trying to recalibrate the IMU on a moving boat is asking for trouble.
The one thing that is important when you calibrate the IMU is that you do it on a level surface.
 
I'm about to take off on a 9-day 100-foot schooner trip in a bay in Southeast Greenland - the ship looks very much like yours:
Schooner Donna Wood

Do you have any suggestions to prepare for flying a P4P during this trip give your recent experience? Love to know what you recommend in terms of preparation to (hopefully) avoid any serious problems.
 
There should have been no need to recalibrate your compass or IMU.
Trying to recalibrate the IMU on a moving boat is asking for trouble.
The one thing that is important when you calibrate the IMU is that you do it on a level surface.

Agree Chief, but I am kinda itchy handed :)
It was the IMU, not the compass.
The P4 wont allow me to take off when it was very sea sick, hence I dared to calibrate the IMU, there is nothing to loose at that point. The mild rolling at anchor during IMU calibration was not good I know, but its flying behaviour was not too bad after the IMU calibration, except the gimbal off horizon.

Afterall the IMU cablibration was deemed successful/acceptable by the flight controller...kinda weird right ?

With landing and take off 100% manual/ATTI after IMU calibration, it is manageable.
Thanks for the reminder.... I wont do it again...LOL
 
New owner question are Manual mode and ATTI mode the same? I have flown in ATTI mode but don't know how to enable a different Manual mode, if it is different (OT: spent a month in Indonesia last year..)
 
I'm about to take off on a 9-day 100-foot schooner trip in a bay in Southeast Greenland - the ship looks very much like yours:
Schooner Donna Wood

Do you have any suggestions to prepare for flying a P4P during this trip give your recent experience? Love to know what you recommend in terms of preparation to (hopefully) avoid any serious problems.


Hi Dhay,

MANUAL = ATTI , that is what I call manual.
Only barometer used as height control. GPS positioning is off, so drone will drift.

Your vessel is smaller, more risky than the one I was on.
I hope you are already comfortable 100% on ATTI/MANUAL for take off and landing.
Your landing real-estate is quite scary with all those sail rigging, unless vessel stay still at anchor.
I was prepared for the worst, which means I brought eye protection and hand protection.

I brought this safety visor, clear type ....no kidding, I value my eyes
Safety Visors - Eye Protection - PPE - Ace Safetywear

Which eventually I do not use, because I do not do hand catch or hand release method for take off or landing.

But it came handy.... I gave the small dive boat driver to wear when it was raining..... LOL
I gave it to the boat crew this safety visor. Its good to wear when changing hot fluids on engines and generators.
Safety Visor came handy.JPG

60% of my trip days were raining.:(

I also bought and brought welding glove which is long , up to near my shoulder . Never use it too. But I was prepared for hand take off and landing.

I done remote area diving trips often and always expect the un-expected when it comes to safety gear, but last June was my 1st with a drone you see.

I also bought the the P4 propeller guard, just in case.... but I never get to use it.
NOTE : propeller guard will de-activate front collision sensor on my P4, if P4P I dont know.
Collision sensor I do not use it anyway.
Phanton 4 propeller guard...obstacle sensing detecting disabled.

Perhaps safety to your eyes, hand and others is what you must treasure most. You are at sea and days from nearest port/medic probably, so be as safe as possible would be wise. No one wants any one to get hurt, but at 1.6+kg weight a P4P is, those props are really dangerous.
When I take off and land the P4, I don't let anyone to be around, I told them to hide one side near the captain bridge. I dont want to take any risk.


I would advise :

01. Take off and land in manual mode, ATTI. Flying around, go ahead use the GPS/P mode.
02. Calibrate your IMU and compass before you board the vessel.

03. Turn off bottom sensor and forward/rear sensors in P4P when taking off and landing.
NOTE : if you turn off your forward collision sensor, my P4 wont be able to do active track. Probably your P4P would be the same. You can turn it ON mid air and turn it off before you land, just don't forget to turn off when landing.

04. Install the propeller guard if I were you. Not only for people, but wire rigging for the sail is so thin, forward sensor wont be able to detect it. With prop guards when you hit something at very slow speed, it can bounce back, instead of prop damage/stoppage which will surely flip your drone.
When you are later more comfortable maybe remove the prop guards, if you need any smart move/shots which relies on forward sensor. Practice on land first. I too don't have enough flying hours on P4 to explain all in detail.

05. Becareful when you do automated orbit ( point of interest ) and the vessel as the POI.
Vessel is long, so the orbit radius must be wide enough to clear the bow and stern + some extra safety margin.

06. Don't get trapped by thinking what you see on video feed means you can fly there.
Line of sight for your controller to drone, always make sure it is done.
If say you take iceberg video, or a hill.... and do a complete circle , but at lower altitude than the peak of the iceberg or hill while your P4P is at the obstructed side, you will loose radio link to drone.

On this live on board vessel, a few drones been lost, I was told by the captain.
Some went into water after hitting the sail rigging.
One went too far and over relying on video feed, went over a hill peak and loose line of sight, and then gone.
One wound the hand of the operator when landing went bad.


Overall most important is you should be able to fly ATTI/MANUAL comfortably.
I come from Phantom 1, so total manual was my favourite, as I even flew it in my living room...LOL.
Now I fly this small trainer quad indoors. Foot print is big like P4. No automation at all, even the hoover is not so stable horizontal and vertical wise, good for training. UDI U818A Drone Review

That is all I can advice you, my knowledge is also limited.

Have a nice and safe trip yah.

BTW, where were you 1 month in Indonesia last year ?:)
 
New owner question are Manual mode and ATTI mode the same? I have flown in ATTI mode but don't know how to enable a different Manual mode, if it is different (OT: spent a month in Indonesia last year..)
Atti is not Manual Mode.
DJI Phantoms have not included a Manual Mode for several years now.
 
I have planned to first calibrate the IMU and compass, 1 night before before going on board
Why? There should be no need to recalibrate either your compass or IMU.
Each passing day the IMU gets more sea-sick as the weather worsen day 3 and thereafter.
It gives me lots of warning when I wanted to take off.
The P4 wont allow me to take off when it was very sea sick, hence I dared to calibrate the IMU, there is nothing to loose at that point. The mild rolling at anchor during IMU calibration was not good I know, but its flying behaviour was not too bad after the IMU calibration, except the gimbal off horizon.
There was nothing wrong with your IMU.
It was telling you there was something wrong with the (rolling) environment you were trying to launch in.
The Phantom needs a fairly stable launch site.
 
Chief,

Thanks for the tip.

I thought rough handling at airports would kinda upset my IMU and compass.

DJI has such advice on their tutorial on IMU, "during transportation, the sensors in the IMU may fall out of calibration" ... so I follow their advice. Its the Phantom 3 though.
At 00:33

Is the phantom 4 IMU more robust ?

At least the magnetic variation could be different if my usual flight area was 2,500KM away. Don't you think ?

I was torn on what drone to bring , of which a proven take off from a rolling boat is possible :
- My 3DR Solo can not take off from anything with even a mild rolling, that is given
- My Phantom 3 Advance surely can take off from a boat, but it can't do 4K and I never actually flew it since I bought it, too limited flying area for me. It also has higher prop vibration compared to P4 , even with a well balanced prop, based on anchored down test.
- My Typhoon H is too big. I actually never flew it yet too, again too limited flying area for me. Except for anchored down test for props vibration test.

So P4 is the best choice.

I guess it has decent enough tolerance to flash IMU warning of the rolling condition as you described, but fortunately still allow me to take off. I seen a lot of hand take off video for P4, so that is why I believed it would do well in shaky shaky take-off platform.

Anyway, the IMU warning went away after I calibrated , albeit the boat was rolling so mildly when calibration took place. I guess during transport and rolling seas a few days, it has some negative effect on the IMU afterall.

Do you have experience with P3 Advance taking off in more shaky-shaky platform compared to a P4 ?
Maybe next time when in a small boat, more rolling ...I will use P3A.

Thanks
 
I thought rough handling at airports would kinda upset my IMU and compass.

DJI has such advice on their tutorial on IMU, "during transportation, the sensors in the IMU may fall out of calibration" ... so I follow their advice. Its the Phantom 3 though.
Is the phantom 4 IMU more robust ?
The Phantom would have to have some very rough handling to affect the IMU.
The compass is unlikely to be affected by bumping around.
The P3 and P4 would be equally robust.
At least the magnetic variation could be different if my usual flight area was 2,500KM away. Don't you think ?
No ... I've flown 3600 km away without recalibrating and noticed no issues.
The current manual for the P4 advises not recalibrating the compass (p51).
I've not seen any evidence that magnetic variation has any effect on the Phantom.
Do you have experience with P3 Advance taking off in more shaky-shaky platform compared to a P4 ?
Maybe next time when in a small boat, more rolling ...I will use P3A.
I'd expect them to be about the same.
 
Thanks for your tips. I'm one part super excited and 1 part nervous that I will lose the drone - time will tell.
(OT: spent a week in Bali, then drove over to Java, up to Borneo then to West Sumatra. very intensive photo tour (zero time on the beach) - highlights were Mt Bromo and the Pacu Jawi (sp?) - bull races in W Sumatra. Loved every minute, especially the textiles and gamelan)

Hi Dhay,

MANUAL = ATTI , that is what I call manual.
Only barometer used as height control. GPS positioning is off, so drone will drift.

Your vessel is smaller, more risky than the one I was on.
I hope you are already comfortable 100% on ATTI/MANUAL for take off and landing.
Your landing real-estate is quite scary with all those sail rigging, unless vessel stay still at anchor.
I was prepared for the worst, which means I brought eye protection and hand protection.

I brought this safety visor, clear type ....no kidding, I value my eyes
Safety Visors - Eye Protection - PPE - Ace Safetywear

Which eventually I do not use, because I do not do hand catch or hand release method for take off or landing.

But it came handy.... I gave the small dive boat driver to wear when it was raining..... LOL
I gave it to the boat crew this safety visor. Its good to wear when changing hot fluids on engines and generators.
View attachment 84894
60% of my trip days were raining.:(

I also bought and brought welding glove which is long , up to near my shoulder . Never use it too. But I was prepared for hand take off and landing.

I done remote area diving trips often and always expect the un-expected when it comes to safety gear, but last June was my 1st with a drone you see.

I also bought the the P4 propeller guard, just in case.... but I never get to use it.
NOTE : propeller guard will de-activate front collision sensor on my P4, if P4P I dont know.
Collision sensor I do not use it anyway.
Phanton 4 propeller guard...obstacle sensing detecting disabled.

Perhaps safety to your eyes, hand and others is what you must treasure most. You are at sea and days from nearest port/medic probably, so be as safe as possible would be wise. No one wants any one to get hurt, but at 1.6+kg weight a P4P is, those props are really dangerous.
When I take off and land the P4, I don't let anyone to be around, I told them to hide one side near the captain bridge. I dont want to take any risk.


I would advise :

01. Take off and land in manual mode, ATTI. Flying around, go ahead use the GPS/P mode.
02. Calibrate your IMU and compass before you board the vessel.

03. Turn off bottom sensor and forward/rear sensors in P4P when taking off and landing.
NOTE : if you turn off your forward collision sensor, my P4 wont be able to do active track. Probably your P4P would be the same. You can turn it ON mid air and turn it off before you land, just don't forget to turn off when landing.

04. Install the propeller guard if I were you. Not only for people, but wire rigging for the sail is so thin, forward sensor wont be able to detect it. With prop guards when you hit something at very slow speed, it can bounce back, instead of prop damage/stoppage which will surely flip your drone.
When you are later more comfortable maybe remove the prop guards, if you need any smart move/shots which relies on forward sensor. Practice on land first. I too don't have enough flying hours on P4 to explain all in detail.

05. Becareful when you do automated orbit ( point of interest ) and the vessel as the POI.
Vessel is long, so the orbit radius must be wide enough to clear the bow and stern + some extra safety margin.

06. Don't get trapped by thinking what you see on video feed means you can fly there.
Line of sight for your controller to drone, always make sure it is done.
If say you take iceberg video, or a hill.... and do a complete circle , but at lower altitude than the peak of the iceberg or hill while your P4P is at the obstructed side, you will loose radio link to drone.

On this live on board vessel, a few drones been lost, I was told by the captain.
Some went into water after hitting the sail rigging.
One went too far and over relying on video feed, went over a hill peak and loose line of sight, and then gone.
One wound the hand of the operator when landing went bad.


Overall most important is you should be able to fly ATTI/MANUAL comfortably.
I come from Phantom 1, so total manual was my favourite, as I even flew it in my living room...LOL.
Now I fly this small trainer quad indoors. Foot print is big like P4. No automation at all, even the hoover is not so stable horizontal and vertical wise, good for training. UDI U818A Drone Review

That is all I can advice you, my knowledge is also limited.

Have a nice and safe trip yah.

BTW, where were you 1 month in Indonesia last year ?:)
 
The Phantom would have to have some very rough handling to affect the IMU.
The compass is unlikely to be affected by bumping around.
The P3 and P4 would be equally robust.

No ... I've flown 3600 km away without recalibrating and noticed no issues.
The current manual for the P4 advises not recalibrating the compass (p51).
I've not seen any evidence that magnetic variation has any effect on the Phantom.

I'd expect them to be about the same.

Thanks Chief :)
 
(OT: spent a week in Bali, then drove over to Java, up to Borneo then to West Sumatra. very intensive photo tour (zero time on the beach) - highlights were Mt Bromo and the Pacu Jawi (sp?) - bull races in W Sumatra. Loved every minute, especially the textiles and gamelan)

Sorry about the MANUAL = ATTI thingy.
I got confused with my past experience with Phantom 1, which can do real MANUAL mode. .. :eek:


OOT :
Nice travel ...:)
I hope the local Indonesian driving style did not scared you ...LOL.

I see you like photos so much and your trip is a Photoworkshop !! Awesome....awesome.
Greenland
I like still cameras , for DLSR photos I have D800 and D500, but I am not that skilled with photos.:confused:
Your P4-Pro with 1 inch sensor and 20MP will do well for aerial if it can do what Sony RX100 can do, assuming the sensors are the same 1" Sony.

If your don't already have one, I recommend 1 camera for fun sake and who knows you can shoot some polar bears from a safe distance. Nikon P900. Up to 90% of its zoom limit, this small 1/2.3" sensor ( P4 size sensor ) is not too bad for a US$600 unit. My highest Nikon tele is only 70-200mm F2.8 as I don't shoot wildlife. I discovered P900 usefulness when my daughter did a 1 hours surf lesson and water is so shallow, she and instructor were very far away from me. This is content/moment over pure quality kind of photo , in fact D500 APS-C at 200mm F2.8 which is only 300mm FF equivalent at best, could not actually better the P900 , object image ratio size to frame being equal.

I cant wait to see your P4 aerial photos of the coming trip...please share some on this forum.

Fly safe....& have fun...
 
Thanks for the note, Indonesia was fantastic. All set with DSLR stuff; we own 600 mm on down to 16 fisheye (and most of the lens in-between - it's my main hobby. D5, D500 and D800E - waiting for new D8xx this summer).
Enjoy your drone.

Sorry about the MANUAL = ATTI thingy.
I got confused with my past experience with Phantom 1, which can do real MANUAL mode. .. :eek:


OOT :
Nice travel ...:)
I hope the local Indonesian driving style did not scared you ...LOL.

I see you like photos so much and your trip is a Photoworkshop !! Awesome....awesome.
Greenland
I like still cameras , for DLSR photos I have D800 and D500, but I am not that skilled with photos.:confused:
Your P4-Pro with 1 inch sensor and 20MP will do well for aerial if it can do what Sony RX100 can do, assuming the sensors are the same 1" Sony.

If your don't already have one, I recommend 1 camera for fun sake and who knows you can shoot some polar bears from a safe distance. Nikon P900. Up to 90% of its zoom limit, this small 1/2.3" sensor ( P4 size sensor ) is not too bad for a US$600 unit. My highest Nikon tele is only 70-200mm F2.8 as I don't shoot wildlife. I discovered P900 usefulness when my daughter did a 1 hours surf lesson and water is so shallow, she and instructor were very far away from me. This is content/moment over pure quality kind of photo , in fact D500 APS-C at 200mm F2.8 which is only 300mm FF equivalent at best, could not actually better the P900 , object image ratio size to frame being equal.

I cant wait to see your P4 aerial photos of the coming trip...please share some on this forum.

Fly safe....& have fun...
 

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