Give your gizmo the gift of sight
This is I guess specifically a question to Geoffrey, but also to anyone on the forums who might know about this. I want to replace the board on a toy rc heli or quadcopter to include an onboard microcontroller and some peripherals (including a centeye chip). I just want to find a starting point by looking at what other people have done (like Geoffrey in his project http://centeye.com/projects/vision-based-hover-in-place/ ) hardware-wise since I've never designed my own board. But I have yet to find anything like what I'm looking for (I was searching the DIY drones forums for awhile).
Good question. I don't want to be discouraging, but it took quite a bit of effort to get the "vision based hover in place" demo working, especially at that size. (That was a $1.4M DARPA-funded project with many twists and turns before we got to that point!) I have, on the side, been working on a replacement for the eFlite mQX micro quad board and have an early version that does work, but it is far from a project I could release. (I'm not worried about proprietary reason, but the documentation for that board is nonexistent and it might be confusing to others!) Are you looking to do this for a school project or for your own fun or for something commercial? Just curious.
I wanted to do it just for fun. I wanted to explore the possibilities of using vision for stabilization and object avoidance on a light weight embedded system, but my idea was to just get to the point where I could have the heli hover in place and then go from there. My attraction to using a micro uav was 1) they can be used indoors and 2) they are cheap! (syma now sells a quadcopter for about $40). Perhaps this starting point is too ambitious though, in which case I may start with a ground based vehicle since quadcopters are still quite pricey.
A question for you...when you did your project, did you need to use more than one camera to hover in place? I believe I read that someone accomplished this with a micro uav using a single camera, but I can't recall what paper I saw that in.
It is pretty easy to hover with one camera and one range sensor (say sonar). We've been able to make a quad hover, barely, with just the camera, but we get better results with two or more. For the demo using that coaxial 'mCX, the 18 cm one, we used eight cameras, but that was a bit overkill.