Tell me what you think.

Views: 539

Tags: DARPA, UAV, UAVforge, VTOL


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Comment by Alex on September 23, 2011 at 5:24am

cool idea, but i would just say that EDFs are not the way to go if you want endurance, at least in my experience, but I have never tested them to compare.

Comment by Sean Skirvin on September 23, 2011 at 6:08am

Nice animation.  I agree with Alex about the EDFs, and would also add that they are quite loud, and I know sound mitigation is one of the things they were looking for.  EDFs also tend to have a high pitch, which can cause turbulence problems during takeoff.  I also wonder how stable that will be during vertical flight, being that you are balancing on top of two thrust points.  Look forward to seeing your progression.  I am working on getting my submission video completed as well.

 

Good Luck!

Comment by Brandin Sloms on September 23, 2011 at 10:14am

my honest opinion, cool animation, but you need to look at the dynamics of your platform a little colser, as per above comment, there is no way your going to balance all that weight on two thrusters, i am a fan of edfs tho.

Comment by John Hestness on September 23, 2011 at 7:10pm

I believe Saturn V rockets balanced a lot of weight just using thrust vectoring.  Still other issues with EDFs though.  But you win for coolest video!

Comment by Sean Skirvin on September 23, 2011 at 8:56pm

True, the Saturn V did that, like other rockets, but a 6 million pound rocket is going to be affected by the crosswind less (density/shape) and more slowly (inertia) than a 6 pound uas.  

Comment by Jacob Eraklidis on September 23, 2011 at 9:47pm

It all depends on $. If both engines can have variable thrust (or variable pitch) and can quickly move their nozzles at high angles then its up to the control algorithm. Just yesterday I saw a tail sitter that didn't have gyros stay balanced. I guarantee you its all about $ not if it can be done. If I had a million dollar budget I would buy a neural net AHRS from these guys... http://www.guidedsys.com/past-programs.php

As for the EDF...I used to work for a fortune 500 company that specialized in Factory Automation(PM servos). Permanent Magnet motors are as efficient as their respective designer. Increasing torque or speed is easy with the right designer... (even I was able improve performance by automating a fly winding technique to increase the number of  turns thus increasing torque)

Its all about $... I will try to post a link of the tail sitters I've seen. What I like about this idea is that it can scale up to a full fighter and thus we can scale down aircraft carrier size. 

Comment by Jacob Eraklidis on September 23, 2011 at 9:57pm

A day after I submitted my video this popped up on my suggestion bar... if you notice the propellers wash onto the control surfaces to increase maneuverability.... no gyros... foam body....  

Comment by Jacob Eraklidis on September 23, 2011 at 10:01pm

btw thanks for the feedback I really appreciate it!

Comment by Jacob Eraklidis on September 23, 2011 at 10:08pm

Also check out an older UAV design I submitted to DARPA... I spoke them it didn't go anywhere but it was interesting thought process to go through....

Comment by Sean Skirvin on September 24, 2011 at 9:27am

I wasn't trying to be overly negative, or say that it can't work.  I was just saying it is not the most inherently stable VTOL platform.  Also, if you can find someone that makes a VP EDF, I would be very interested to play with one.  As for the second video you posted,  the main reason it is staying stable is the pendulum effect of lifting from the top, and like you said the fact that its rotors wash over the control surfaces, both things not seen in your design/animation.

 

(even I was able improve performance by automating a fly winding technique to increase the number of  turns thus increasing torque)

NICE - Hand winding is a pain!  What percent increase in turns did you achieve?

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