Posted by noleary 2 days ago
Higher end stuff will use a ton of inputs (visual odometry, binocular vision, lidar, range finding, etc) fused into some kind of proprietary blended algorithm that you could probably call an MPC.
RL is pretty cutting edge, especially for fast path motor control; there are a lot of university competitions for drone control that lead to a lot of papers and projects in the space (some promising) but most commercial stuff has not adopted this yet, certainly not at the low end.
On top of this (Maybe at a few hundred hz), you can add outer controls to set attitude. This could be an autopilot, or having the controls command attitude instead of rate. Betaflight pilots usually don't both with this, and have the simple setup of control maps to rate.
I've programmed firmware using a weird hybrid where the controls command a change in the target attitude. So it flies like rate, but has the forced attitude stability of an attitude-based control system. Non-standard, but makes it so you don't need to worry as much about tuning the PID loop. In practice, you can do full aerobatic flight with this like you'd do with a rate-only setup. (Basically, there is a commanded attitude quaternion; controls nudge it; the PIDs update motor power to maintain this commanded quaternion.)
And frankly as a pilot, I'd rather not see any completely autonomous drones with no oversight in the sky - that's one incident away in which blame cannot be put solely on the operator from getting the hobby completely banned.
The delta between what is possible with current autonomous flight missions and manual FPV style flight is by having a brain on board that can dynamically adapt to a changing environment. There are a finite amount of PID profiles for each steadystate solution that a researcher can preprepare for. But RL allows an overarching heuristic to transiently alter the PIDs depending on the changing environment.
We use PIDs because analyzing robotics platforms as seeking a steadystate dramatically simplifies the math needed to where its computationally possible for us to solve for a situation.
We use RL in systems that have continuously changing environments with transient solution spaces that are easier to model in hyperspace with a RL model.
Take for example platforms that have tiltrotors. They ideally have a minimum of 3 PID profiles for flying. One when it best fits a multirotor profile. A second when it is transitioning from multirotor to fixed wing flight, and a third for when fixed wing flight is established. What happens when the researcher has a need to fly in the transition state, or subconfigurations of the states? How many PID profiles are you looking to think of and train for? This is where RL has dividends.
I've got a question: why CNC milling and not just FDM 3D printed parts? TFA doesn't talk much about it except saying she went to a machine shop.
> 2. CNC milling forms out of G-10 fiberglass (arms) and 5mm carbon fiber (body)
TFA also says this:
> The solution for this is to 3D print a 0-tolerance assembly jig to hold the arms in perfect position while the center of the drone is superglued together.
Why not 3D print it all?
There's this guy who built a drone that can fly for 3 hours and cover hundreds of miles, 3D printed at home on a $250 printer:
Then there was the $200 K quote for the body for a car that just did Pike's Peak with a four times Pike's Peak champion and instead the team... 3D-printed the car's body at home (something like 40 parts, assembled together), which cost them less than $2 K to make (1/100th of the quoted price for the car's body). Here's the vid where they print all the parts (on a $1500 consumer printer):
Basically: why CNC milling and not 3D printing at home when many drones enthusiasts (and now too people building race cars) simply print parts at home on a consumer-grade 3D printer?
Copter-style drones are exposed to vibration across a huge frequency range in every axis, and it's almost impossible to avoid really nasty resonance issues using generally-printable FDM filaments and "standard" design techniques; it's a lot easier to just use super-stiff carbon fiber and CNC it.
For planes, like what you linked, 3D printing is more "plausible" than for copters but also not really practical; you can 3D print a good plane, but plastic lacks the durability and favorable weight characteristics of foam - plastic planes tend to be "one time crashed" while foam is easy to repair, restore, and rebuild.
Which also means great people can go beyond what’s their school was about, so a CS major doing CNC isn’t “weird” or different, I remember when applying for jobs in systems in aerospace industry and get rejected despite having a systems background too, with feedback of “they are looking for people with education only in aerospace”, which is idiotic thing to consider.
So good luck OP, start exploring hacking mavlink or similar protocols which is what im working on.
I'd expect an engineering project with "no prior experience" to take weird/experimental approaches more often compared to a "from scratch" project (where I would expect proven minimalism instead).
You think s/—/--/g is more work than rewriting a whole article? Is this what you're saying?
The name "octocopter" does not make sense. "Helicopter" is a compound word made of "helico-" and "pter", which means "screw-wings". "Octo-" means eight, "-co-" means nothing.
"Octopter" would be a correct compound word meaning "8-wings", but that would be ambiguous, so the object discussed in TFA is better named just "8-propeller drone".
Multi-rotor drones have been called tricopters, quadcopters, hexacopters, octocopters based on their propeller counts conversationally for as long as I can remember.
There are plenty of commercial vendors who use the exact term for their expensive industrial drones.
Update: I see that in the four minutes it took for me to validate my initial inclination and post that plenty of others also had the same thought :) No need to me to belabor the point!
Oh, language changes and now "nit pick" means "to make trivial criticisms" even though neither "nit" nor "pick" etymologically has anything to do with criticisms? How very self-serving of you ;)
A nit pick with your post - you use the word 'ambiguous' but really this is from the latin root 'ambiguus' so we don't need the supurflous 'o' in between the two u's.
gyrocopter, helicopter, quadcopter, hexacopter, octocopter, parcelcopter, and—most famously—
roflcopter, https://en.wiktionary.org/wiki/roflcopter#/media/File:Roflco...
They all have their own dictionary entries.
Octocopter makes perfect sense. Everyone understands immediately what it means, and that's the only purpose of language: to convey ideas. It should be clear, which this is, and concise, which this is.
Fidelity to ancient Greek is not, and should not, be a goal for English.
