1000W LED on a Drone [video]
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Consider a golf course that can deliver cold beer out to the green via drones. 8 ice cold beers at ~10lb in a few minutes via cellphone app. A drone could probably do that 5 times on a single charge, and swapping battery's is easy. Charge 2$ extra per beer and it's both rather profitable and for now a unique experience.
Saves massively on gas and people time (especially when self driving trucks are mainstream) and in theory are the main way you might deliver packages in a fully autonomous delivery setup.
Sure, if you're an electrical engineer, you might want to stay with an all electric thing (and electric engines are flexible) -- but if one was serious about lifting packages, it would seem you'd want to explore other, well-tested options that give you more lift/flight time?
I mean, if we can deliver hellfires from drones, surely we can deliver some books?
http://mydronelab.com/blog/gas-powered-quadcopter.html
I don't know whether they use direct coupling or motor-generators, though.
Model aircraft engines have a long and time-honoured history. My father was into them as a child in the 1950s (before radio --- you controlled them by swinging them round your head on wire harnesses!), and still has some of the engines. Beautiful, beautiful engineering; about the size of my thumb, which ran on some ghastly cocktail of exotic oils and volatile spirits.
But, if your going with tilting blades just use a helicopter design which is mechanically simpler than 4 tilting blades.
EX: There are some options that don't involve a swashplate. (ZX-35041) considering it's 20$ it's probably junk. But, notice how the tail blade is pointing up.
You could build a tilting quad copter with 4 engines, but that's significantly more complex. You can also use one engine and get power out to the 4 blades but that also get's complicated. Still the point still stands, Quadcopter's need to get more complicated as you scale them and things like vibration make everything worse.
What amazes me at those little things is how little side-to-side drift they have, considering that's all depending on the CG being well centered.
A nice variable pitch quad: https://www.youtube.com/watch?v=Vy5Ky50eGJs
However, in the end people have tried a lot of man sized flying designs and for vertical takeoff and hovering helicopters really are about as simple as it get's.
Yeap, nailed it, apparently, vibrations are its biggest issue.
Also, I think the cost is more from how modular the thing is, it's very much a professional product which limits sales.
PS: Looking at lose curves, it should be able to do 1hour with 5lb and significantly more battery's. But you get more total flight time with fewer battery's that your hot swapping.
While one is in the air, the other is getting its battery packs swapped out.
I'd like to learn how to program a quadcopter and be able to fix the hardware just in case something goes wrong.
However, my main problem is that I don't know where to start. I do not have a hardware background.
Does anyone know some good resource? I'd prefer if it had nothing to do with the scratch language
* PX4,
* ArduCopter (actually uses parts of PX4),
* PaparazziUAV.
All of them are great starting points if you want to develop additional useful functionality (e.g. package drop, autonomous mapping/patrol)- implementing even the bare minimum pitch/roll/yaw stabilization functionality takes a lot of effort.
The easier way to enter this domain is using an on-board/companion computer (typically RaspberryPi/Odroid) to control the autopilot using high-level commands (e.g. fly to these coordinates, activate that output etc).
Background: I have spent ~2 years working on (sadly) unreleased products in this domain.
Who's doing these kind of products? I've done some things with the PX4 and I love it, the guys doing it are super smart. I've worked on some indoors navigation stuff but I wasn't very experienced at the time and the project turned into a mess.
Regarding PX4- completely agree. People working on it definitely have high standards for software engineering practices and sense of responsibility. ArduPilot guys are also doing very good job, especially regarding state estimation (sensor fusion).
Indoor navigation is sadly not fully solved problem, at least for open-source solutions. I have not tried it, but IMO the best option at the moment seems to be Qualcomm's drone platform, as that has high-resolution, wide angle camera and enough processing oomph for image processing.
PX4Flow did work on some surfaces, but did not work too well on highly repetitive textures (e.g. office carpets). The image sensor, although is very good (global shutter, large, sensitive pixels) had limited resolution and even more limited was processor doing image processing.
The fusion of flow data was also quite unstable for ArduCopter and PX4 (they both shared the state estimation code at that point). Some of the problems were implementation issues (e.g. a few bad measurements caused the rest of (now valid) measurements to be ignored) but some were fundamental ones. The algorithms in use relied on constant distance between camera and objects on scene (required for calculating velocity in uniform units) which was unrealistic assumption indoors (e.g. flying near walls, over tables, etc).
The Qualcomm platform, as far as my understanding goes, still uses the PX4Flow. I don't know what packages they have for vision but it uses ROS so I assumed it had some ROS package powering it.
Px4Flow on its own is insufficient, but I was under the impression that it is able to calculate velocity even with variable distance camera-to-surface, they do have the ultrasonic sensor there and apparently, adding a lidar greatly improves performance.
PX4Flow can calculate velocity when camera-to-surface distance varies, no doubt about it. The problem is when single frame contains features at various distances (e.g. lidar/sonar measures distance to ground, but half of the frame also sees table which is a lot higher).
Something small like an arduino can be used for attitude control, heading hold, etc., which is itself directed by a mission computer (the RPi) which can manage more complex, higher level behaviours.
https://www.edx.org/course/autonomous-navigation-flying-robo...
> Autonomous Navigation for Flying Robots
> You will learn how to infer the position of the quadrotor from its sensor
> readings and how to navigate it along a trajectory.
Sidenote: I wonder what the Hello World of drones is.
Then possibly something one day doing something like this:
( http://robohub.org/drones-recognise-and-follow-forest-trails... or directly http://ieeexplore.ieee.org/document/7358076/ and probably available on sci-hub )
If we're searching for something that we don't know an approximate location of, depriving everyone around of night vision, making it impossible for helicopters to be nearby and possibly even making thermal imaging devices less useful are disadvantages enough. The only advantage I can see is increased depth and color perception.
If we're searching for something that we know an approximate location of, fair point. Alas, I expect that this is a rarish situation (we either know that the missing person is somewhere in the general area, or within voice range in this particular direction; or we have visual contact).
If we've found something/someone and need to move it/her, we either are in no hurry and need little illumination or we're in a hurry and really care about night vision while carrying the person later or care about being helicopter-friendly (bright light most certainly isn't).
I can't imagine other SAR usecases (other than essentially searching or rescuing).
The first commercially available one I know of (no longer produced):
http://www.curtisyoungblood.com/legacy-product-support-curti...
A knock-off of the Stingray:
http://www.hobbyking.com/hobbyking/store/__77122__Assault_Re...
A big exception: this thing is massive and works with nitro and 2-stroke engines:
http://www.curtisyoungblood.com/legacy-product-support-curti...
http://www.lumicycle.com/mountain-bike-lights/summit-range/s...
That lamp is 1,100 lumens on standard high power, lasts over 4 and a half hours at that brightness. And if needed, there is a boost mode that gets you 1,650 lumens but only for a couple of hours.
This is for the smallest battery, a 2.6ah that weighs 220gms.
And if you're wondering, yes my bicycle has insane lights. 2 of those and then a 605 lumen dynamolamp giving 3,905 lumens on a bicycle. Yes,I chose tight beam and aim at the ground about 10m ahead, unless I leave the city when I put one wide beam lamp on and raise it a little.
French Agency for Food, Environmental and Occupational Health & Safety noted [1] some points that might not be photo-biologicaly safe, the main points being:
> spectral imbalance (significant proportion of blue light in white LEDs);
> high levels of radiance (high brightness density per surface unit emitted by these very small sources)
In the french version of their report, they refer to luminance [2] rather than radiance.
The spectral imbalance photochemical risk seems linked with cumulative dose of blue light, so there is also a risk with low but long exposure light LED screens. It also perturbs circadian cycle (flux or redshift might help in that case).
See also a previous HN discussion about a warning from the American Medical Association about the spectral imbalance in LED streetlights [3].
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[1] https://www.anses.fr/en/content/led-%E2%80%93-light-emitting...
Edit: I watched the video without sound.