RC aerial vehicles: because we don't have flying brooms

The Something Awful Forums > Discussion > Hobbies, Crafts, & Houses > RC aerial vehicles: because we don't have flying brooms

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mashed: Jul 27, 2004

The thing I really don't understand with that wedding photographer is what was he trying to do. I don't think that most peoples romantic wedding photography dream is fast passes of aerial photography.

I could understand a slow push in or a slowish orbit. But screaming straight at them to zoom above their heads doesn't seem wedding appropriate to me. But vOv dude is obviously a dumbass.

# ? Aug 17, 2013 17:25

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# ? Apr 27, 2024 20:27

NitroSpazzz: Dec 9, 2006; You don't need style when you've got strength!

At the local cars n' coffee this morning and hear a humming noise. Without even looking I know it's going to be a drone flying over the large group of people and expensive cars. Yup four quads total buzzing around throughout the show. Some nice equipment but none of the operators had an answer to what happens when a prop/motor/esc/etc fails and they have to make an emergency landing :doh:

Just a matter of time...apparently they go to all the events (anything with large crowds) in the area and get footage for fun. poo poo at least when I was doing AP I stayed away from people, had an emergency landing plan, spotters and the ability to auto-rotate unless something went really wrong.

# ? Aug 18, 2013 15:28

mashed: Jul 27, 2004

NitroSpazzz posted:

Some nice equipment but none of the operators had an answer to what happens when a prop/motor/esc/etc fails and they have to make an emergency landing

https://www.youtube.com/watch?v=q7kwhtslOYQ But props never fail... This was my first and only so far quad crash when a prop adaptor came loose. You can see the crazy vibrations its generating as it works its way loose. But yeah an emergency landing wasn't an option after it came free...

Crash is at ~1:20

mashed fucked around with this message at 20:29 on Aug 18, 2013

# ? Aug 18, 2013 15:41

MRC48B: Apr 2, 2012

Is it possible for a quad autopilot to compensate for the loss of one of the props?

Maybe make it limp to the ground in a semi controlled manner?

# ? Aug 18, 2013 19:13

CrazyLittle: Sep 11, 2001; Clapping Larry

MRC48B posted:

Is it possible for a quad autopilot to compensate for the loss of one of the props?

Maybe make it limp to the ground in a semi controlled manner?

Not really, no.

# ? Aug 18, 2013 19:46

mashed: Jul 27, 2004

MRC48B posted:

Is it possible for a quad autopilot to compensate for the loss of one of the props?

Maybe make it limp to the ground in a semi controlled manner?

Not for a quad. A quad without a prop is like kicking the leg out from a 4 legged table. You can only start getting redundancy with a hexacopter or octocopter depending on flight controller. Also a Y6 which is a tricopter with two motors per arm or an X8 which is a quad with two motors per arm can have decent redundancy. However you are potentially carrying a lot of extra power for redundancy in those cases as a single motor has to be able to do the work of two to be able to recover properly. Also the flight controller has to be able to respond quickly enough to avoid entering some crazy spin.

# ? Aug 18, 2013 20:28

Sagebrush: Feb 26, 2012

How does the quadcopter know when a prop has been lost? Tachometers on each motor looking for overspeeds?

# ? Aug 19, 2013 02:06

CrazyLittle: Sep 11, 2001; Clapping Larry

Sagebrush posted:

How does the quadcopter know when a prop has been lost? Tachometers on each motor looking for overspeeds?

It doesn't. Instead it just starts spinning on an axis and tells the missing motor to speed up to compensate.

If you have a more complex multirotor it can send power to the additional motors on the missing site to compensate, but that's not possible on a quad.

# ? Aug 19, 2013 03:59

Sagebrush: Feb 26, 2012

Oh, I see. So on a hexacopter, if you lose one prop the two motors beside it on that "side" will increase their power by ~66% (well all three motors will increase power) as the machine compensates for the roll. It'll wobble, but stabilize itself if you have enough altitude. Right?

But on a quadcopter there's no way to compensate so it just spins and falls.

I do wonder, though, if you could save it by monitoring motor current. If a prop flies off or flies apart, that motor (under less load) is going to start drawing a lot less current, and you could theoretically detect that drop vs. the other motors, assign it as damaged and do...something. Deploy a parachute? :v:

# ? Aug 19, 2013 04:20

CrazyLittle: Sep 11, 2001; Clapping Larry

The brushless motor controller has one signal wire that receives its throttle value from the brain. They don't really send information back to the flight controller. So unless you want to build multiple tachometer interfaces into the FC and go around the ESC, then the brain would never know. It's just sending the signal to the motor blindly and expecting it to work. I guess you could write a failsafe routine that says, "if I'm spinning out of control pop the chute" but that could easily be triggered by any other unintended gust of wind.

CrazyLittle fucked around with this message at 05:02 on Aug 19, 2013

# ? Aug 19, 2013 04:58

Sagebrush: Feb 26, 2012

Well yeah it wouldn't be possible with a stock quadcopter. I think the best way to do it would be with inline current sensors going to your Ardupilot. Or to a little external ATMega watchdog that alerts the flight controller if anything is wrong.

# ? Aug 19, 2013 05:08

mashed: Jul 27, 2004

I've seen tons of demos of people making chute systems for multicopters. But every time they pop them they are expecting it. I haven't seen a test of a real world situation which would be the multi going into an uncontrollable spin with most likely zero warning.

I'm sure it can be done. I'm just not sure if anyone has actually made a robust system like that yet.

# ? Aug 19, 2013 16:58

Beve Stuscemi: Jun 6, 2001

Sagebrush posted:

How does the quadcopter know when a prop has been lost? Tachometers on each motor looking for overspeeds?

It would be based on load, not RPM, because the computer is telling a brushless motor what RPM to run at.

ABS systems for brushless cars work the same way.

# ? Aug 19, 2013 19:09

Sagebrush: Feb 26, 2012

Jim Silly-Balls posted:

It would be based on load, not RPM, because the computer is telling a brushless motor what RPM to run at.

Yeah I realized that about 30 seconds after I posted it. :downs:

# ? Aug 19, 2013 21:37

mashed: Jul 27, 2004

If you had per esc current monitoring it would be pretty easy to tell if a motor suddenly lost a prop as the current draw would drop massively compared to the requested throttle input. However I don't know of any flight controlers that support that sort of current monitoring. The APM 2.5 can monitor total current draw which is great for a fuel gauge type application but doesn't let you monitor individual motors.

The thing that worries me more is a motor failing just due to getting worn out. Some sort of way of monitoring motor health would be great. I don't know if anything exists.

# ? Aug 20, 2013 01:12

Muppet Danny Brown: Sep 24, 2006; Smell like a penguin

There are ESCs that have power logging. For motor health, RPM sensors will do the trick. Frsky for example has RPM sensors that plug into a telemetry hub. Using an Arduino, it might be possible to translate these into Mavlink and pass it through the APM. I've done the reverse by passing the APM's Mavlink through an Arduino nano into Frsky protocol to the receiver, and then display that telemetry on my transmitter.

A good preflight check to get in the habit of is spinning up your motors on a level surface for a second, then make sure they all stop at the same time. Should let you see if you have a bad bearing. I disregarded a motor spinning down much faster than the others, and it failed two hundred feet up. Actually it may have taken longer to spin down. Either way, the other three all stopped simultaneously. Having a bearing seize midflight is an awful feeling, because there's nothing you can do about it on a quad. I've switched to a hexa because of it.

# ? Aug 20, 2013 06:05

mashed: Jul 27, 2004

Symbolized posted:

A good preflight check to get in the habit of is spinning up your motors on a level surface for a second, then make sure they all stop at the same time. Should let you see if you have a bad bearing. I disregarded a motor spinning down much faster than the others, and it failed two hundred feet up. Actually it may have taken longer to spin down. Either way, the other three all stopped simultaneously. Having a bearing seize midflight is an awful feeling, because there's nothing you can do about it on a quad. I've switched to a hexa because of it.

How is the APM for hexacopter redundancy? I've heard mixed things about whether it can actually deal with it. I am tempted to change my f450 frame to a f550. It wouldn't cost that much to do.

# ? Aug 20, 2013 18:10

Muppet Danny Brown: Sep 24, 2006; Smell like a penguin

I've had a mixed experience with the APM. I switched from a f450 to a f550 frame, and the change has been altogether positive. I had switched from multiwii to APM on the f450, and the APM just has awful acrobatic flight capability. If I fly too aggressively the quad, and now the hexa, will tilt over to the left so much I have to give it full right pitch. If I give it more than 75% throttle going straight up, it'll tilt nearly horizontal until I throttle down.

On the other hand, no flight controller comes close to its automated flight, landing, and waypointing. And there's Android telemetry apps that let it follow my phone's GPS signal and allegedly even steer it from the phone, if I ever get the nerve to try that. So it has a really robust suite of features. But I enjoy acrobatic flight a lot, even though I'm truly awful at it. And the multiwii has unparalleled acrobatic flight ability.

I'd say definitely upgrade to the hexa, the downside is more moving parts and cost, but it will have better lift, stability, and redundancy. This post has anecodotal evidence that it's possible to fly a hexa on five motors, but I haven't tested it personally as I've been sorting out the leans. More motors seems to work better as a rule. I'm thinking of going coaxial on the f550 frame to make a dodecacopter. I've spent too much money on this hobby this month though.

# ? Aug 21, 2013 00:01

mashed: Jul 27, 2004

Symbolized posted:

I'd say definitely upgrade to the hexa, the downside is more moving parts and cost, but it will have better lift, stability, and redundancy. This post has anecodotal evidence that it's possible to fly a hexa on five motors, but I haven't tested it personally as I've been sorting out the leans. More motors seems to work better as a rule. I'm thinking of going coaxial on the f550 frame to make a dodecacopter. I've spent too much money on this hobby this month though.

My current quad is setup as an aerial video platform so aerobatic flight isn't a priority. I have been thinking of building a beater quad with multiwii or something along those lines purely for acro stuff.

Its about an $80 cost to go to the hexa and it isn't that much bigger and should have about the same flight times as more motors is balanced by less hover throttle.

# ? Aug 21, 2013 00:28

Muppet Danny Brown: Sep 24, 2006; Smell like a penguin

If its for aerial video, the more motors the merrier. A hexa will lift more equipment, and won't fall out of the sky if a motor seizes. An octocopter would be even better. To fill my acrobatic urge I got a hobbyking pocket quad for $47, about 70mm long, 30 grams, and runs on an integrated multiwii chip. Should be able to take acro indoors.

# ? Aug 21, 2013 03:03

Vitamin J: Aug 16, 2006; God, just tell me to shut up already. I have a clear anti-domestic bias and a lack of facts.

MRC48B posted:

Is it possible for a quad autopilot to compensate for the loss of one of the props?

Maybe make it limp to the ground in a semi controlled manner?

Yes:
http://www.ted.com/talks/raffaello_d_andrea_the_astounding_athletic_power_of_quadcopters.html

Not really practical for our applications, though.

# ? Aug 21, 2013 15:58

mashed: Jul 27, 2004

Vitamin J posted:

Yes:
http://www.ted.com/talks/raffaello_d_andrea_the_astounding_athletic_power_of_quadcopters.html

Not really practical for our applications, though.

Until those sort of tricks can be done without an external mocap rig they aren't going to be of much practical use outside of cool university demos. Cool stuff though. I'd be interested to see how their system would react if it lost a single prop as opposed to props symmetrically opposite each other.

# ? Aug 21, 2013 21:49

WaterIsPoison: Nov 5, 2009

mashed_penguin posted:

Until those sort of tricks can be done without an external mocap rig they aren't going to be of much practical use outside of cool university demos. Cool stuff though. I'd be interested to see how their system would react if it lost a single prop as opposed to props symmetrically opposite each other.

Stanford did research into autonomous autorotations. That said, it's difficult to get the state of the art state estimation and control systems on embedded platforms to run quick enough for consumer platforms.
https://www.youtube.com/watch?v=3wI4dwqfIdc

# ? Aug 22, 2013 16:46

ease: Jul 19, 2004; HUGE

mashed_penguin posted:

Until those sort of tricks can be done without an external mocap rig they aren't going to be of much practical use outside of cool university demos. Cool stuff though. I'd be interested to see how their system would react if it lost a single prop as opposed to props symmetrically opposite each other.

I'm not sure why you couldn't do that with current technology (that most people are using) on a quad. Would the spin from releasing the yaw constraint simply be too fast to pulse the ESCs appropriately? I really haven't looked into how these IR quads are flying, but I'm assuming they are still using some kind of flight controller, but positional information is being done off board.

ease fucked around with this message at 20:30 on Aug 22, 2013

# ? Aug 22, 2013 20:28

mashed: Jul 27, 2004

ease posted:

I'm not sure why you couldn't do that with current technology (that most people are using) on a quad. Would the spin from releasing the yaw constraint simply be too fast to pulse the ESCs appropriately? I really haven't looked into how these IR quads are flying, but I'm assuming they are still using some kind of flight controller, but positional information is being done off board.

Sorry I wasn't referring just to the prop damage demo. I was more talking about the cooperative stuff with catching, the net throw etc, which are not possible without super accurate external position sensors.

# ? Aug 22, 2013 20:43

Muppet Danny Brown: Sep 24, 2006; Smell like a penguin

This pocket quad is surprisingly stable. Runs on multiwii and, with the pitch/roll rates high enough, is really acrobatic. It is decently hard to break, too.

# ? Aug 23, 2013 01:15

ease: Jul 19, 2004; HUGE

I just got my daughter a Syma X1, which isn't that small. But, small quads are really really fun.

# ? Aug 23, 2013 01:59

Sagebrush: Feb 26, 2012

Symbolized posted:

This pocket quad is surprisingly stable. Runs on multiwii and, with the pitch/roll rates high enough, is really acrobatic. It is decently hard to break, too.

I assume that's this HobbyKing quad, right? It says it needs a DSM radio...I'm a bit foggy on radio terminology but could I plug a transmitter module like this one into my Turnigy 9X (w/ ER9x) and fly it?

# ? Aug 23, 2013 02:10

Mantle: May 15, 2004

My Syma X1 literally arrived in the mail today and I'm having a hard time controlling it. I thought I saw someone here post from Victoria BC. If you're around would you be willing to show me the ropes?

# ? Aug 23, 2013 02:56

Muppet Danny Brown: Sep 24, 2006; Smell like a penguin

Yeah its a blast to flip it indoors. Sagebrush, yeah that module will work for the standard DSM receiver the pocket quad comes with. I already had a Frsky module in the 9x, so I used a d4r-ii on PPM.

# ? Aug 23, 2013 03:16

Beve Stuscemi: Jun 6, 2001

Jim Silly-Balls posted:

Do you have a transmitter?

This is a drat good deal: http://www.amazon.com/gp/aw/d/B006R6ERLE/ref=mp_s_a_1_2?qid=1376093647&sr=8-2&pi=SL75

$69.99 seems to be the going rate for MQX's now since Horizon dropped their MSRP down to that price. Holy shiiiiit go buy an MQX now they're so fun. This applies to everyone.

Also, hopeful that this means that there is a new MQX in the works. They did the same drastic price drop with the original UMX beast before they brought out the Beast 3D

# ? Aug 23, 2013 17:02

Mantle: May 15, 2004

Will these V959 batteries also work with the Syma X1? They're the same voltage and look like they use the same connector. Here's some pictures of the Syma X1 battery and underside.

# ? Aug 24, 2013 05:16

ease: Jul 19, 2004; HUGE

Yeah if the voltage is the same, it will work fine, you'll just have to modify the harness on the quad a bit.

Price seems really high tho:

http://www.amazon.com/Battery-Upgra...ords=x1+battery

# ? Aug 24, 2013 13:59

Mantle: May 15, 2004

Is the price high? It's for 5 batteries, so it works out to about $4 each. Lower capacity though.

Have some battery charging questions though:

So if I get those batteries with this harness and this charger, is there anything I have to worry about? How does the charger "know" when the batteries are full? I read somewhere that the charger has overcharge protection, but how does that work when I'm charging 5 at once? What if the batteries are in different states of discharge?

Edit: Let me make this simpler. What's the best way to charge these 5 batteries at once so I can have indefinite flight time?

Mantle fucked around with this message at 06:12 on Aug 26, 2013

# ? Aug 26, 2013 02:15

Nerobro: Nov 4, 2005; Rider now with 100% more titanium!

My only problem with the mQX is that it's ugly as hell. The NanoQX... well I was flying it out side in 6-8mph winds. It was fun.

Amusingly, annoyingly, I can't find my CX2.

The MSRx... the AS3X means you can't do "realistic" takeoffs. You need to launch it off the ground. And I do most of my flying in a 8x10' room. It makes takeoffs harrowing.

# ? Aug 26, 2013 02:49

ease: Jul 19, 2004; HUGE

Mantle posted:

Is the price high?

Ooops didn't notice the gigantic red 5x.

# ? Aug 26, 2013 13:19

NitroSpazzz: Dec 9, 2006; You don't need style when you've got strength!

Well this isn't good news - http://wtvr.com/2013/08/24/watch-drone-crashes-into-crowd-at-great-bull-run/ Looks like it crashed in an empty spot which is lucky.

quote:

DINWIDDIE COUNTY, Va. (WTVR) � A drone grabbing video of Saturday�s historic bull run in Dinwiddie County crashed into the crowd.

It happened at the Virginia Motorsports Park just before the 12 p.m. wave of the Great Bull Run kicked off.

The drone had been flying high above the track before it neared the stands. As the flying object dipped down, it steadied for a bit before taking a sharp left, speeding up and crashing into the stands.

There has been no word if anyone was injured.

On a more positive note think I'm finally setting up a proper-ish RC work area this afternoon. What does everyone's workbench setup look like?

NitroSpazzz fucked around with this message at 16:02 on Aug 26, 2013

# ? Aug 26, 2013 14:16

Beve Stuscemi: Jun 6, 2001

Nerobro posted:

My only problem with the mQX is that it's ugly as hell. The NanoQX... well I was flying it out side in 6-8mph winds. It was fun.

Amusingly, annoyingly, I can't find my CX2.

The MSRx... the AS3X means you can't do "realistic" takeoffs. You need to launch it off the ground. And I do most of my flying in a 8x10' room. It makes takeoffs harrowing.

My MQX body is beyond trashed, so I run a solo cup body. Problem either solved or made worse depending on your opinion.

poo poo still owns though. Once you ditch the stock body that acts like a drat parachute, you can fly the MQX in some crazy winds.

# ? Aug 26, 2013 17:01

CrazyLittle: Sep 11, 2001; Clapping Larry

NitroSpazzz posted:

Well this isn't good news - http://wtvr.com/2013/08/24/watch-drone-crashes-into-crowd-at-great-bull-run/ Looks like it crashed in an empty spot which is lucky.

Heh. Looks like it was a DJI Naza-GPS or DJI wookong octocopter.

Boy this looks familiar

CrazyLittle fucked around with this message at 19:37 on Aug 26, 2013

# ? Aug 26, 2013 19:25

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# ? Apr 27, 2024 20:27

NitroSpazzz: Dec 9, 2006; You don't need style when you've got strength!

CrazyLittle posted:

Heh. Looks like it was a DJI Naza-GPS or DJI wookong octocopter.

Yup and from what I've seen that's a fairly common failure mode.

Again in happier news instead of getting my RC area setup my HK order with 9XR arrived after sitting in customs for two weeks. Needless to say I haven't accomplished anything today. I will say the nano QX is awesome and now that I finally figured out nano CPX setup it's going to be fun.

# ? Aug 26, 2013 21:55

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