18

Thrust is proportional to the change in momentum of the air passing through the prop - i.e. how much the prop speeds it up. The power required to do this is proportional to the kinetic energy of the air, which is proportional to speed squared. That 'squared' is the problem. A smaller prop acts on less air, so it has to speed it up more to generate the ...


17

An explanation for why this is can be found in this Aviation.SE answer: Why aren't large, low-speed propellers widely used?, which I'll paraphrase here. The thrust a propeller generates is a function of its velocity and geometry. It makes sense that a propeller spinning faster will also generate more thrust. For a smaller propeller to generate the same ...


7

You have a few options. One is to switch to a digital video system such as the fat shark bytefrost and do something like this to convert the video to a format compatible with your laptop. Essentially the above link documents how to convert a digital FPV feed into your laptop for doing low latency video calling, but you don't have to do the video calling part....


6

Comment number 7 at this link is an excellent source (and fairly trustworthy as it was written by Joshua Bardwell). The main reason specified for the efficiency is that for a given amount of thrust, a larger propeller (on a motor with an appropriate KV) will draw less current than a smaller propeller on a higher KV motor, so there is less sag. Another ...


6

The strength of an electromagnetic signal will attenuate (decrease in strength) over long distances between the receiver and the transmitter due to the inverse square law, but this phenomenon applies equally to all wavelengths/frequencies. The main difference in transmission distance capability between long-range RC systems like TBS Crossfire and FrSky R9M (...


5

So many different issues, I study a lot of the FAA regulations closely but have contemplated this same question a few times. The power and weight of gear is heavy, so to make it all the way around is not going to happen without a lot of hacking. (solar proof of concept or similar notwithstanding) Efficiency of solar (power and weight) is a problem. The ...


5

At this point I would recommend the radiomaster TX16S. It goes for about the same price as the other radios you list but has everything you need to get you going for a very long time. FrSky (Taranis) is doing everything it can these days to lock you into their ecosystem and you need to start hacking once you are further in the hobby and want to switch over ...


4

The flight you describe is 100% illegal in the US requiring 107/commercial license + BVLOS waiver. BVLOS waivers are very rare, 61 issued searching the DB for "107.31" here: https://www.faa.gov/uas/commercial_operators/part_107_waivers/waivers_issued/. The rules are similar in most countries. Your budget is off by a zero as well. Depending on ...


4

This is not possible, at least directly. Although the two technologies use the same frequency range, they are very different communication protocols. A possible solution would be to buy a compatible video receiver (which might be the goggles) which has a video output - typically composite, for analogue systems - and a USB video capture card for your laptop. ...


3

Reinforcement Learning can be used for UAV control. This video details a method to use RL for quadcopters. In summary, you program a model of your UAV that effectively simulates your drone. You then create a policy and value neural network to control your drone and train it using your simulation. I'm pretty sure similar methods are used in zipline's ...


3

It is a totally different communications protocol than the 5.8GHz wifi your laptop supports but there are devices for under $30 that let you receive the video on an android phone or a windows laptop such as Skydroid 150CH. I'm not recommending any particular product but you're basically just looking for a USB 5.8GHz FPV Video receiver. Without buying an ...


3

The easiest way to think about this is to remember that drag increases with the velocity squared. A smaller propeller will have to spin faster to achieve the same thrust as a larger propeller, and spinning faster creates more more drag.


3

If you are not interested in hard, real-time control and can accept some autonomy in the drone, then your best choice is satellite communication. The iridium based modules are lightweight, (45 grams), and are easy to integrate (they have USB and Serial connections). One example is RockBlock. You pay per message, and one message (50 bytes) is just about ...


2

To my knowledge, the most readily available consumer long-range RC control system is the Crossfire ecosystem from Team BlackSheep. It makes use of the 868 MHz/915 MHz band and supports RF transmission powers from 10 mW to 2000 mW. Under good conditions and given well thought out antenna orientations, TBS Crossfire can achieve some truly ludicrous ranges for ...


1

Remember - it only takes 3 points to get a solid fix on location in 3 dimensional space. I have been thinking about this a lot, I will also have a unit on day 1 and possibly the unit disassembled day 2 and posted on line (maybe) For the Amazon device there is most likely a sonar/echo or similar system that creates a feedback loop for position. I also suspect ...


1

The control range depends on the frequency, power and how the transmitter sends the data (the 'mode'.) Power More power gives longer range (much like a brighter light can be seen from further away.) However, as the frequencies are shared there are laws in each country1 which limit the maximum power you can use; this prevents it becoming a 'free for all' ...


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