Sunday, October 25, 2009

Build construction started

Great progress with the table construction this past weekend! Jess and I worked out some general plans for the table and on Saturday acquired the material to begin building. With the help of Philip on Sunday the table began to take shape. Acrylic has been framed with LED light strip and mounted inside an aluminum U-channel frame. As time allows we will continue to work out details of the table and build it out.

I have tested the acrylic layer out with the vision system and it works great, though blob tracking was not great. I suspect its just a matter of isolating the IR inside an enclosure and probably more importantly tweaking settings in the vision system software to get the best out of our system. All in all things are going very well, expect some build photos in a while.

Friday, October 16, 2009

All parts acquired!

Good news everyone, we now officially have all the parts we need to fabricate our surface! Today I picked up the EndLighten acrylic, which is in fantastic condition, as well as the BenQ projector. I thought the acrylic was in 4:3 format, but getting to look at it today it looks like it may be 16:9...which our projector can do. Also cool to note is the acrylic's edges have come polished, which may sound like a stupid thing to mention, but this was cut from a larger piece of acrylic and the seller was kind enough to have the leftover pieces polished up, which we would have had to pay to get done right.

As for the projector the make and model are listed in the previous post. I hooked it up today and tested it out and am happy to say that the picture quality is crisp and bright and the throw distance is amazing. Its also very compact and quiet, which are real bonuses.

If I can find the time over fall break I will try to get the surface built (i.e., enclosing the LEDs and acrylic within a metal frame) so we can have that ready to drop into a table later on. If that sounds a little confusing here is a graphic that may help:


(click for full size)

Sunday, October 11, 2009

First status update

Our build process will hopefully be documented here in the days / weeks / months to come, but to start things off and get everyone up to speed. Check out the links on the sidebar to get to some valuable information about MT technology and what we're looking to achieve with this project.

Here is the status of our project at the start of this blog:

Projector:

BenQ Mainstream MP522 ST - A short throw projector that should fit our needs well

Vision system:

Modified PS3Eye from PeauProductions.com - has been modified to include a suitable IR bandpass filter (meaning the camera will only see light in the IR range, specifically 850nm wavelength) as well as an adjustable M12 camera mount and lense. This is a standard lense mount for cameras and will allow us to focus and fine tune our vision area to achieve the best blobs possible

Lighting:

5m long flexible strip of IR LEDs from EnvironmentalLights.com - specially made 8mm wide flexible strip of SMD mount IR LEDs that will essentially be wrapped around the edge of our acrylic surface to provide IR light from within the acrylic layer itself. This item has been ordered with accompanying 60W power supply

Acrylic Layer:

33”x25”x8mm sheet of EndLighten acrylic - A special made type of acrylic that has been manufactured with a lot of very small reflective bits, which essentially will diffuse the IR light coming from the edges uniformly. This piece of acrylic will “glow” with IR light, which will be reflected downward when someone touches the surface. Due to high degree of illumination, no compliant surface layer will be needed, though an extra layer of very thin acrylic may be placed on top to prevent scratching. HUGE thanks to Eli Fox-Epstein from the NUIGroup.com forums for providing us with this acrylic and being super patient while payment was sorted out.

Once we have all of these parts we will test them out and then design a free-standing table to house them in.


Status of parts:

Projector - ordered

Vision system - acquired

Lighting - acquired

Acrylic - ordered