At Last! The Hover Segway!

[Isidore]

Early work on the next flying Segway is progressing well, but you may have trouble getting it through a standard doorway:

http://www.flixxy.com/worlds-first-manned-flight-of-an-electric-multicopter.htm

[Civicsman]

In the case of failure of any of the rotors, the remaining rotors are capable of successfully guiding the machine to the crash site.



(with apologies to one of the engineers on the NASA Phoenix program)

[KSagal]

Seems entirely appropriate, but shouldn't he have been standing up?;)

Good find. Thanks.

[goldwing_midland_tx]

I sure hope there is a good safety switch on that, as I would hate to walk by one of those props when it turned on.

[KSagal]

I sure hope there is a good safety switch on that, as I would hate to walk by one of those props when it turned on.

It is clearly a test vehicle. Can you imagine having a picnic in a field and having this land too close? It would be like looking up and seeing a food processor coming down.

All these safety issues are real, but not too much a problem, till we see it developed to a point where they would be available for sale, however.

I kind of like the idea that the primary landing pod is an exercise ball. Very ingenious.

[gbrandwood]

Are those straps to keep him from falling out or stopping him from running away in terror!!!

As stable as quadrocopter+ can be, they don't crash well. My AR.Drone was no exception.

[KSagal]

Are those straps to keep him from falling out or stopping him from running away in terror!!!

As stable as quadrocopter+ can be, they don't crash well. My AR.Drone was no exception.

Would a quadrocopter have 4 rotors? I think this device has about 12 rotors if I counted correctly. What would that be, duodecacopter?

[Isidore]

Would a quadrocopter have 4 rotors? I think this device has about 12 rotors if I counted correctly. What would that be, duodecacopter?

It has 16 props so its a hexadecicopter I think. Wonderful flying bedstead design, combination of high tech and string. The exercise ball is great but I wonder why his seat is not below the structure rather than above.

[Lily Kerns]

It has 16 props so its a hexadecicopter I think. Wonderful flying bedstead design, combination of high tech and string. The exercise ball is great but I wonder why his seat is not below the structure rather than above.

Actually, his pose looks to me as if it is very uncormfortable and unnatural.

[KSagal]

It has 16 props so its a hexadecicopter I think. Wonderful flying bedstead design, combination of high tech and string. The exercise ball is great but I wonder why his seat is not below the structure rather than above.
__________________
Regards Isidore

Actually, his pose looks to me as if it is very uncormfortable and unnatural.


I must have counted 3 rotors per arm (I did a quick count, clearly missing only 25% of them, lucky I don't deal with numbers for a living... No, wait, I am an electromechanical Engineer. I guess I'll blame this one on my glasses)

I too see that the sitting with that much weight above the lift as odd. I would have thought having it below or at lease some of it below would add a level of stability.

My understanding of the stability of other than fixed wing aircraft generally tend toward low weight, high lift, like a helicopter, rather than like a hovercraft. Most hovercraft get very unstable if they lift above ground effect, if they can.

[Bob.Kerns]

I presume the pilot would not want the thing coming down on top of him.

Weight high isn't unstable, it's meta-stable. Which means, if you keep it oriented, just like on a Segway, it's fine. It's when things get out of control that you get instability.

Even so -- I suspect the center of gravity isn't that far from the plane of the rotors, and possibly even below. Where are the batteries? How much do the motors weigh?

[KSagal]

I presume the pilot would not want the thing coming down on top of him.

Weight high isn't unstable, it's meta-stable. Which means, if you keep it oriented, just like on a Segway, it's fine. It's when things get out of control that you get instability.

Even so -- I suspect the center of gravity isn't that far from the plane of the rotors, and possibly even below. Where are the batteries? How much do the motors weigh?


Bob,

I said that the weight of the rider, if below the lift plane would add a level of stability. Are you really saying it would not?

Just like on a segway, a high weight is a destabilizing factor. Just because when a segway is working properly, it can compensate does not mean it is more stable than if it were designed otherwise.

And most flying machines that I know of have to deal with all sorts of degrees of instability, and the better designed ones can recover from at least some level of it. Any machine designed to not be able to deal with at least some instability will not be much of a success, or use, or even safe.

I guessed the white boxes on the arms below the motors were the battery packs, which would do a reasonable job of distributing the weight. If the entire machine were relatively symmetrical in weight, instead of a central weight and outlying lift arms, it would have a different flight characteristic. I don’t know that it would automatically be more or less stable, but by distribution the weight, individual components and frame members might be able to be made from lighter materials.

I agree, the empty machine (sans pilot) does look like the center of gravity is most likely below the props, but that pilot is a pretty big weight, and does appear relatively high to me.

Still, the whole device seems pretty light, and light duty. I am still curious, and if it came to a town near me, I might glide on over, and check it out.


As far as your first statement that the pilot would not want the thing coming down on him made me think that I would equally not want to fall off my perch and fall onto that field of spinning rotors either.

[Bob.Kerns]

[COLOR=black][FONT=Verdana]Bob,

I said that the weight of the rider, if below the lift plane would add a level of stability. Are you really saying it would not?

No. I'm saying it may be more stable than it appears, and not be worth the negatives involved.

Just like on a segway, a high weight is a destabilizing factor. Just because when a segway is working properly, it can compensate does not mean it is more stable than if it were designed otherwise.

Agreed. You are comparing higher/lower and more/less stable. I'm looking at how stable the actual device is. Both are correct. Yours is a basic physical principal. Mine is an estimate. So yours is MORE correct, if you'd like to compare.

And most flying machines that I know of have to deal with all sorts of degrees of instability, and the better designed ones can recover from at least some level of it. Any machine designed to not be able to deal with at least some instability will not be much of a success, or use, or even safe.


Yes, I tried to bring out this point as well. But remember, this is a test prototype, being deliberately operated very conservatively in a very controlled environment. The safety tradeoffs will be different, from a vehicle operated in a wide array of environments and weather conditions, by pilots of various skills, over longer periods of time, with more opportunities for lapse in attention -- any of the host of factors a real-world device must be safe.

I guessed the white boxes on the arms below the motors were the battery packs, which would do a reasonable job of distributing the weight. If the entire machine were relatively symmetrical in weight, instead of a central weight and outlying lift arms, it would have a different flight characteristic. I don’t know that it would automatically be more or less stable, but by distribution the weight, individual components and frame members might be able to be made from lighter materials.

I agree, the empty machine (sans pilot) does look like the center of gravity is most likely below the props, but that pilot is a pretty big weight, and does appear relatively high to me.

Still, the whole device seems pretty light, and light duty. I am still curious, and if it came to a town near me, I might glide on over, and check it out.


As far as your first statement that the pilot would not want the thing coming down on him made me think that I would equally not want to fall off my perch and fall onto that field of spinning rotors either.

I think he's adequately restrained from that happening. But with the assembly being lower to the ground, if he dumps, there's less freedom for it to rotate out of control. If it were above him, it could turn close to 90 degrees.

Also, his position gives him a clear view of many of the rotors, and he can watch both the device and the ground at the same time. I don't think he could do that if he were below it.

As a test setup, it doesn't seem like an unreasonable configuration to me.

Perhaps you're familiar with the Hiller flying platforms? They actually depended on the pilot's weight shifts and sense of balance for stability.

http://www.hiller.org/flying-platform.shtml

[Bob.Kerns]

In case you're curious -- I'm comfortable in stating that my ESTIMATE is CORRECT, on the grounds that it is imprecise enough to surely include reality. Not all that big a claim, really. As much a matter of care in wording as any feat of engineering insight.

[Isidore]

If you search the web there are very many equivalent devices with from 3 to about 8 props, but all are small devices, typically about 400 t0 700 mm across. They are all gyro stabilised and some have amazing manoeuvrability- I've seen videos of these things sticking themselves upside down to a ceiling or a wall using reverse thrust. The commercial driving force is, I suspect, micro surveillance devices. Some have gps receivers so can be made on command to home back to a start location or keep station over a specific point with a sort of dynamic positioning system. Here are such devices:

http://www.multiwiicopter.com/products/carbon-scarab-hexiikopta-12mm-airframe-hexcopter-multiwii
http://vimeo.com/23010622
http://vimeo.com/groups/multicopters/videos

The man capable one is just a scaled up version (you can see what I think are the batteries duct taped to the frame) and therein lies the problem- I think they are getting to the point where from a weight point of view carrying a lightweight gas driven generator would give you much greater endurance, and if you also kept some battery capacity for emergency power, much greater safety.

[GadgetmanKen]

I think perhaps a couple of reasons he is above the rotors is, one because of visibility and turbulance might be less above and he could strap a chute to himself and eject if need be, or land it somewhat safer with one above it.
They do have some helicopter toys that have a circular ring around the rotor blades, it wound be somewhat safer with them also.

[gbrandwood]

Inspector Gadget managed quite well with only one prop and being below it rather than above.

http://forums.segwaychat.com/attachment.php?attachmentid=1835&stc=1&d=1321208488

[KSagal]

Inspector Gadget managed quite well with only one prop and being below it rather than above.

http://forums.segwaychat.com/attachment.php?attachmentid=1835&stc=1&d=1321208488

My point exactly! Have I won you over?