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Otrobotics
11-01-2006, 17:57
My team recently attempted to start building parts of the field. Unfortunately, we couldn't find the box for the vision target, as well as the majority of the miscellaneous parts. I was just wondering if other groups in this competition received the the frame, since our group only received the lights, transformers and lexan cover plate. Were they included in the kit or were groups expected to custom build or buy them? If so, where can they be bought?
EricH
11-01-2006, 18:01
If it wasn't on the list of kit parts, it shouldn't have been included. It wasn't on the list, was it? I believe there are plans out there (I would guess FIRST website). And, the target itself (sans box) was the only part of the field provided by FIRST; you have to build your own practice field (unless another team allows you to share theirs).
devicenull
11-01-2006, 18:01
Thats all you get for the box, you have to build the rest yourself (It's not that hard, shouldnt take too long)
jskene
11-01-2006, 19:55
Aside from some double-sided tape, velcro and some wooden spacers, you only need the aluminum housing, which is Hammond part # 144-26. You can buy it here:

http://www.mouser.com/index.cfm?&handler=data.listcategory&D=*144426*&terms=1444-26&Ntt=*144426*&Dk=1&Ns=SField&N=0&crc=true
coastertux
11-01-2006, 20:36
There is a scematic in the documentation on the FIRST website. Direct link below:
http://www2.usfirst.org/2006comp/Drawings/2006_TFE_VISION_TARGET.pdf
Greg Marra
11-01-2006, 20:58
Why bother buying it and waiting for it to arrive when you can make it in an hour or two out of aluminum or wood?

Asides from that fact that buying it means you won't have the jankiest looking vision target ever...
jskene
12-01-2006, 07:35
You can certainly make it out of wood, but you should line the back with brushed aluminum if you want to replicate the reflectance of the aluminum chassis that is used on the competition version.

A wooden box will not reflect as much light off the back, and the target will appear to be less bright than the target your robot will see at the competition.
skillinp
14-01-2006, 14:17
How about covering the inside of a wooden box w/aluminum foil?
David55
14-01-2006, 15:00
Building the box is not a big deal.
The entire construction of the vision target took us about two hours.
We used blocks of foamed PVC to build the box, and the rest (cathodes, transformers and cover) came in the kit.

http://img269.imageshack.us/img269/858/visiontarget2zm.th.jpg (http://img269.imageshack.us/my.php?image=visiontarget2zm.jpg)

http://img347.imageshack.us/img347/3623/visiontarget29pm.th.jpg (http://img347.imageshack.us/my.php?image=visiontarget29pm.jpg)
devicenull
14-01-2006, 17:57
Building the box is not a big deal.
The entire construction of the vision target took us about two hours.
We used blocks of foamed PVC to build the box, and the rest (cathodes, transformers and cover) came in the kit.

http://img269.imageshack.us/img269/858/visiontarget2zm.th.jpg (http://img269.imageshack.us/my.php?image=visiontarget2zm.jpg)

http://img347.imageshack.us/img347/3623/visiontarget29pm.th.jpg (http://img347.imageshack.us/my.php?image=visiontarget29pm.jpg)

I think you need to be careful of heat on that.. metal would distribute it pretty nicely, but thats going to hold it all in..
jerry w
14-01-2006, 18:30
How about covering the inside of a wooden box w/aluminum foil?

don't worry about the reflection inside the box. our wooden box was bright enough to see at any distance. and up close was so bright that it saturated the camera. of course, the plywood base was very light colored.

jerry w
Jon K.
14-01-2006, 19:01
Has anyone else found that the camera seems to like lighting tubes as well as the green light? Our camera while being tested today sometimes locked on to our lighting in our facility.
Windwarrior
14-01-2006, 19:19
yeah, our cam also like to follow the flouresent tube lights in the ceiling. We finally decided to call it a day and trouble shoot it tommorow.
Billfred
14-01-2006, 19:24
Has anyone else found that the camera seems to like lighting tubes as well as the green light? Our camera while being tested today sometimes locked on to our lighting in our facility.
1293 also found that it seemed to like the ceiling as much as the vision target.

After a bit of fiddling, though, we got the target tracked quite nicely.
Rick TYler
14-01-2006, 20:44
If you are worried about reflectivity, it might be easier to paint the inside of your plywood light box white than to line it with foil. Don't forget to drill cooling holes in your box.

I am not the camera guy on our team, so I am NOT an expert on the camera. As I posted elsewhere, I talked to a very experienced robotics engineer who said that the CMU camera is prone to oversaturation from ultraviolet, which most fluorescents produce in abundance. He used a UV filter on the robot that won the Robo-Magellan competition at the 2005 Seattle Robothon event. Unfortunately, I don't know what kind of filter he used.
AV_guy007
14-01-2006, 22:37
I think you need to be careful of heat on that.. metal would distribute it pretty nicely, but thats going to hold it all in..
ours is metal but we also put a small muffin fan in it to keep it cool
bbene
15-01-2006, 12:28
ours is metal but we also put a small muffin fan in it to keep it cool

We made ours out of wood that is close to white on the inside. It is still very bright. Just for efficient cooling I plan on putting both an intake and exaust fan in it. I have yet to do that.
jskene
15-01-2006, 15:59
You should make sure that the reflectance of the inner surface of your light box is similar to that of the one your robot will look at during competition, otherwise your camera will be incorrectly calibrated.

That's why we went with the Hammond chassis recommended in the drawings. It costs a few dollars more than the wooden box, but the resulting brightness should be identical to that on the competition field.