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Old Sep 04, 2011, 10:16 PM
fly the best
United States, CA, Tustin
Joined Apr 2010
174 Posts
Help!
few questions ondesigning a ornithopter for senior design class

Hello, my group for my university senior design class has decided to design and build a ornithopter that will mimic the characteristics of a bird and be capable of carrying a small camera or FPV setup.
We are having trouble finding research on ornithopters. we have found quite a few aiaa papers discussing aerodynamics of flapping wing MAV's, and control systems, but we havent found any research that has designed a ornithopter from scratch and built it.
So I guess my questions are:
How do you decide on the what the requirements for the Ornithopter will be?
eg.
wingspan:
Flapping frequency:
mass:
Power/weight ratio:

also is there a published method for calculating the thrust and other forces on the ornithopter?
does anyone know any good books maybe?
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Old Sep 05, 2011, 07:53 PM
Ornitopters Taste Like Chicken
FlapHappy's Avatar
Nashville, TN
Joined Jul 2009
174 Posts
A camera platform designed fom scratch is a very ambitious first attempt, however...

Try this link: http://ornithopter.de/english/wings.htm
There you will find the history and overview of ornithopter development over the years and it may give you some design ideas. There are also links to other references which may be helpfull. As for your other questions...There are too many variables to give you a straght answer. You may gain some insight by looking at the specs of Sean Kinkade's birds at www.flappingflight.com, or the many videos on here by Kazu-kaku which also give specs to his birds. Both of those are mostly membrane wings, but there is info on other types like the EV-1 which is more airplane type wings. Patricia's web site: http://www.ornithopter-pilot.com/ is very interesting as is http://ovirc.free.fr/ .
To determine the size, power to weight, etc., you should start with your payload weight and work backwards from there. It is an ambitious project and I hope you all the best!
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Old Sep 06, 2011, 01:42 PM
fly the best
United States, CA, Tustin
Joined Apr 2010
174 Posts
Ornithopter Testing

Okay thanks for the links they were very helpful.

I had another question that I was hoping that you could help me with. We were looking at the Smartbird by Festo and we noticed that in order to test its performance they were using a stand where the bird would fly around. I am guessing that this was used to test the lift/thrust but I am not sure exactly how they did that. Also I saw a very similar tested used in other videos that were posted by fellow ornithopters so if anyone knows and could tell me that would be much appreciated.

I guess on the same lines as that, does anyone else know any other methods to test the performace of ornithopters?

Thanks you all and good flying,

Jonathan Tovar
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Old Sep 06, 2011, 03:19 PM
Kjell Dahlberg
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Mallorca Spain
Joined Nov 2005
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This is the test bench I am using. The second one is easy to make from a motor wheel.
Kjell
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Old Sep 06, 2011, 05:06 PM
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Joined Nov 2006
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Hey, I like that bike wheel idea. I happen to have a spare bicycle wheel
so I think I'll try building something like that.
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Old Sep 06, 2011, 09:04 PM
fly the best
United States, CA, Tustin
Joined Apr 2010
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Quote:
Originally Posted by KJELL View Post
This is the test bench I am using. The second one is easy to make from a motor wheel.
Kjell
Hello Kjell,

Thank you for the suggestion. It is definitely what I was talking about. I was just wondering what exactly is the device measuring? I get the idea but I am not sure what it is supposed to tell us about our ornithopter's performance.

Also this may be a stupid question but what exactly are all the components that I would need to build one? I guess I am just asking is there any other ways to build it?
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Old Sep 06, 2011, 11:56 PM
Kjell Dahlberg
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Mallorca Spain
Joined Nov 2005
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This is one of my prototype tests in the test bench.
MONOBIRD (1 min 13 sec)
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Old Sep 07, 2011, 02:19 AM
Kjell Dahlberg
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Mallorca Spain
Joined Nov 2005
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Quote:
Originally Posted by sharkforce View Post
Hello Kjell,

Thank you for the suggestion. It is definitely what I was talking about. I was just wondering what exactly is the device measuring? I get the idea but I am not sure what it is supposed to tell us about our ornithopter's performance.

Also this may be a stupid question but what exactly are all the components that I would need to build one? I guess I am just asking is there any other ways to build it?
You need one platform with adjustable legs. So you can level the test bench.
Fix the wheel to the platform. The swinging arm must have a counter weigt.
Let me know if you need more information.
Kjell
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Last edited by KJELL; Sep 07, 2011 at 09:07 AM.
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Old Sep 13, 2011, 04:28 AM
fly the best
United States, CA, Tustin
Joined Apr 2010
174 Posts
alright, one more question, has there been any progress in implementing a autopilot for an ornithopter? eg. using ardupilot, ardupilot mega, RVOSD5, paparazzi. from what I read the flapping motion of the ornithopter could mess with the INU's in these systems. One way I think an autopilot could work is using an infrared sensor based autopilot that would not be affected by the oscillations from flapping.. however from what i have seen those are not used much anymore because INU's have gotten cheaper.

edit:
the festo bird uses a 3 axis accelerometer, but their implementation of it or any real info from festo is non existent.
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Last edited by sharkforce; Sep 13, 2011 at 04:57 AM.
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Old Sep 13, 2011, 05:04 PM
Ornitopters Taste Like Chicken
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Nashville, TN
Joined Jul 2009
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Quote:
Originally Posted by sharkforce View Post
alright, one more question, has there been any progress in implementing a autopilot for an ornithopter? eg. using ardupilot, ardupilot mega, RVOSD5, paparazzi. from what I read the flapping motion of the ornithopter could mess with the INU's in these systems. One way I think an autopilot could work is using an infrared sensor based autopilot that would not be affected by the oscillations from flapping.. however from what i have seen those are not used much anymore because INU's have gotten cheaper.

edit:
the festo bird uses a 3 axis accelerometer, but their implementation of it or any real info from festo is non existent.

Don't you mean IMU / INS? Yes, work is being done in this area, but you won't find any info in this forum. Better to ask in the UAV forum, but I doubt you will find much in the public domain.
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