Hello
I need to know which kind of drone can be used to take good photos in the environment that I’m going to describe:
- inside a large pavilion
- the objects to be photographed are models of breakwaters (about 5m long and height of about 0.5m) build inside water tanks. The breakwaters (built with rocks and concrete blocks) are scaled (according to real breakwaters).
- we have several breakwaters to be photographed, and this is a regular work. Sometimes one breakwater is repeatedly photographed during a day
- photographs must be taken 3m above the breakwaters
- the photos will be used by photogrammetric software
- the camera weights 600g (maximum). Lighter (borrowed) cameras can be used (200g or 300g).
We made two experiments:
1st: not using a drone (a camera was fixed to a support with a long arm) and we know that photos must be taken above the breakwaters, downwards direction (vertical) because we must have good images of the rocks and blocks that are under water.
2nd: with a drone (a toy; a quadcopter Parrot). It originated the turbulence of the water (=waves) so the images didn’t have any info of what was going under water (the objects underwater were blurred).
From these experiments we think that a system that can fly like a helicopter (slowly and that can be “steady” during a few seconds, the time needed to take a photo) could be a good system.
Can you suggest drones that can fulfil the needs?
best regards
Maria Henriques
Replies
The problem with a Multirotor is the amount of turbulence that will be created underneath it. It will surely affect your experiments.
I would be thinking about a carriage suspended by cables attached to the walls or roof. This is a bit low tech, but will not affect your experiment, will be steady, and you can remove the camera and replace it into the exact same place and orientation very easily.
+1 for James' suggestion.
It's too easy to get carried away by technical solutions. I always try to think K.I.S.S. first!
I must think about the carriage. There have been other colleague (that has experience with ballons) that defends that solution.
I agree that is low tech but in fact it looks that is the better solution
thank you
Maria
Hi Maria,
What an interesting use of a flying vehicle. Based on my limited understanding, knowledge and experiences using UAV to work on the watery area (mostly outside though), I would suggest:
A multirotor carrying extended stick with gimbal (stabilizer) with a camera attached so that the wind created by the propeller of the multirotor won't create waves in the tank. Basically the multirotor itself flies not exactly above the tank (how big is your tank by the way?) but somewhere near, where the camera attached to the gimbal and stick is exactly above the tank.
That's what I can really imagine for now. However, I can imagine that you might want those multirotor to fly steady (in loiter mode) horizontally and vertically I suppose. This is, I think, would pose a challenge as it depends on the GPS acceptance (indoor) of your system. But I guess there are good "indoor) GPS out there in the market.
Good luck and best regards,
R
Hi Rai
I can't use systems that rely on GPS: the roof and the structure of the pavilion are of metal. The drone must be driven by someone. You're right: a stabilizer is important.
The tanks are large, some meters long. And quite often the breakwater is in the midle, several meters away "land". See phtos attached.
The photos were taken inside the pavilion (they are included in bwa and bwb files):
bw1- a “big” breakwater
bw2- a breakwater under test. Waves are produced to “see” their effect on the breakwater. We don’t took photos during this phase. Only when the water is “calm”, with no waves.
bw3-the pavilion
bw4-the pavilion
bw5-a harbour protected by breakwaters
bw6-a breakwater
best regards
Maria
bwa.jpg
bwb.jpg
Hi Maria,
Thanks for the picture, I try to imagine how is it like inside the pavilion :). So, IMHO, gimbal is really substantial then for your objective as the multirotor will be flown by somebody. From the images you attached, I try to spot space where the air-fluid flow created by the propeller will not cause 'noise' at the other fluid (water). To my limited sense for the pavilion I can imagine that behind the chair in bw6 is quite a space there which might be the flying 'point' of the multirotor. Then you can attach the extension structure (stick) with gimbal and camera to reach the area above the tested breakwater. I somehow hope it is useful Maria, I am sorry if it's not. I tried my best to position myself in that pavilion through the images you attached.
Best regards,
Rai
Thank you Rai for your interest.
Do you have any idea of how long a arm can be?
My "afraid" is that, with an arm, the multirotor becames instable.
I have NO experience with drones and all the images I see from multirotors the whole (multirotor+cargo) is very symmetrical, with the weight in the vertical of the center (the center of mass in near the center of the drone).
best regards
maria