Quads: We might be doing it wrong?

by ipetepete | November 14, 2013 | (0) Posted in Just Fun

There is a lot to consider between quads and tri's. Both have their pros/cons. The biggest differentiating factor is efficiency, and maybe simplicity of building. I recenlty came accross an article that proposes a slightly different approach to rotor configuration that sounds fairly compelling, which is a hybrid, taking the best of a tri, quad, and heli into one airframe increasing efficiency and manuverability. Unfortunately I couldnt find a video of the quad design, I would love to see one in action.

 

Article in question: http://spectrum.ieee.org/automaton/robotics/aerial-robots/iros-2013-should-quadrotors-all-look-like-this

There is some R&D being done with some variable pitch rotors with some very exciting results: 

 

 

I would love to see what the hybrid can do. So with that. Lets get to hacking!

 

- Find this article & others like it at www.FliteTest.com -

COMMENTS

engineer on November 25, 2013
I love seeing new ideas in this field! Looking forward to seeing something like this working.

I'm still quite new to RC, but I've got a few thoughts on this style, and would like some help understanding the overall design (comments welcome!):
It seems to me that the big pros for the design is the large lifting capacity of the main rotor and enhanced yaw capacity in a sort of hybrid between v-tail and regular quads. The cons look like this style is more expensive (large multirotor motors and esc), and a much more complicated control system. It seems to me that if it used collective pitch, the number of channels required increases dramatically, or that the multiple rotors are not necessary. Alternatively, without collective pitch, would not the control scheme shown cause some issues with the gyroscopic procession of the main blade (pitch input cause roll and vice versa)?

Love to hear your thoughts! Good find!
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ipetepete on November 25, 2013
Couldn't agree more. I figure the program running the thing (MultiWii, KK, etc..) would account for the speed up/down of the smaller motors and keep the rotors spinning in proportion to the others, its definitely a more complicated program, might take a fair amount of tuning based on all the possible variables in motor/rotors/frame sizes. I really want to see a video of it in action, if I find one, I'll be sure to post it.
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24367dfa on November 25, 2013
looks like a nice idea, just completely ignores why multicopters became popular in the first place: mechanical simplicity. compared to helicopters with their swash plate, variable pitch rotors and other small mechanical parts the 4 rotors directly attached to the motor shafts made fr a simple and robust system, that allowed people to get into RC flying on a much smaller budget. all of these benefits get neglected by this design.
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ipetepete on November 25, 2013
Good point. My title may have suggested that this is a replacement for multi-rotors, but this might have another place/application in the RC world, say those that want a stunt rig with the versatility of a multi-rotor. I don't think that this design would be a good entry into the hobby or genre, but suggests that there may be a whole new way of flying than we're used to.
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brandx on November 26, 2013
I have explored these and it is a bit of a misnomer. You can get the efficiency of lift and use of smaller rotors to trim but they are all working in dirty air and cause issues with vibration and efficiency(to a small part like the y8) Lengthen the shafts on the smaller rotor out of the dirty air and it is a good lifting platform.
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brandx on November 26, 2013
What I forgot to say is that some of the issues with different air frames can be resolved with some of the nice new affordable gimbals. All swings and roundabouts (no pun intended)
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JewSlayer101 on December 17, 2013
Ok ok- play some Euro style Techno music & edit the heck out of the video with some high speed passes & some basic flips & a couple funnels & sensationalize the crap out of it , what do you have! An overrated, overpriced quad that nobody is really interested in. It's far to expensive to crash for what it can actually do...
I can honestly tell you that I can do every trick this video aside from the inverted stuff! It's completely possible to do rolls, loops, flips, funnels without the expensive collective pitch gizmo... As far as we are concerned this was just another attempt to market something to death & possibly make as much money they could with their clever little invention. Take note that if it was a successful platform every other big designer & their competitors would be jumping on the bandwagon. How come guys like Gaui, Align, E-flight, thunder tiger, hobbyking, aren't producing one of these? Bottom line it would be about the same thing as an automobile manufacturer making a car that did wheelies! It looks cool but it's just not what cars are for
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Quads: We might be doing it wrong?