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Showcasing the Vision Deck- A FTIR case study
Posted: 26 May 2009 02:28 PM   [ Ignore ]
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Hi,

This is a long overdue post… The table has been functional for more than a year but we keep adding things to it so we never call it “final” smile

(Long post and lots of pictures)

Basic data about the project

Code Name: VISION DECK
Technology: FTIR
Device type: Horizontal table
Display: Projector, Benq MP622c
Display area: 85cm x 65cm, 100cm+ diagonal, 4:3 format
Enclosure: 1m x 0.8m x 0.9m (w x l x h) box (Sorry jimihertz, we like rectangular boxes rasberry)
Construction material: Black, 1.8 cm thick particle board (chipboard) with plastic and metal insertions
IR source: 850nm LED ribbons, 2 sides
Sensing: Sony PS3 EYE
Filtering: 850DF10 bandpass filter on the camera + Hot mirror on projector
Cooling: Active, 4 Fans+airflow pipes, 2 Intakes, 2 Exhausts, Peltier Cooling
Computer: Custom made case, minimal hardware parts, Core2Duo 2.4 GHz, overclocked to 3 GHz, Nvidia 9400 GT
Rigid Surface: Acrylic 8mm thick
Compliant and Projection surface: refined Tinkerman’s technique + Vellum +semi-rigid transparent adhesive foil+ low-friction matte windows film
Optical path: Folded, 2 mirrors, 1 fixed, 1 adjustable in 3D
Mobility: 4 brake wheels + 4 adjustable height plastic feet
Power supply: 1 ATX power supply for the computer+fans+IR-Leds+Logo+Control Box Leds
Operating System: Windows XP
Tracking application: CCV

Features

1.  Computer controlled projector
Using the RS-232 connection provided by the projector an application has been implemented to start the projector when Windows starts. While the projector is warming up, the application disables windows keys and functions such as ctr-alt-del, alt-tab, the taskbar, the desktop icons, systray etc and modifies the start menu to show only multitouch apps. CCV is started, b is pressed after 5 seconds (useful in the days of tbeta), flosc and then a flash app (would need a flash app loader). By the time the projector is on, the user sees only multitouch content. When the app senses a windows shut down it powers off the projector and waits until the lamp is cooled to allow the internal box fans to remain powered (Same power supply for all, when the system stops, fans cease to operate). The app was developed in Delphi and it’s very small.
2.  Rear illuminated Logo
The Vision Deck logo has been made from a clear Plexiglas piece and several layers of plotted film have been added to it to form the logo where the letters V, D and the vision deck text are covered in matte film. Using 4 white LEDs placed on the side of the logo when the system is on the logo is lighted.
3.  Control Box
Under the logo a small circuit has been made to start and stop the system and to control power to the IR LEDs and Fans. It also houses the remote of the projector in case it’s needed for image adjustments (although the control application can perform these tasks) The logo module has a push-lock switch and can be rotated so that it exposes the control box, effectively hiding it and preventing accidental tampering. 3 red Leds show the current state of the system (power, IR, fans)
4.  Drag-release retractable power cord
(Vacuum cleaner technology rasberry) the cable can be retracted under the table for fast deployment or extended up to 6 m.
5.  Invisible ventilation
All the fans are on the bottom of the box and airflow is directed through aluminum pipes for cooling the projector and the computer. Under the table each fan takes/releases air from/to the environment in a different direction so the hot air is not recycled underneath the box. This system keeps the overall temperature inside the table below 30 degrees and the projector and video card at max 43 degrees as shown in a thermal vision photo of the box later in this post.
6.  Modular design
All components can be removed easily. The top frame (containing the acrylic and leds) can be detached and it is locked into place with 4 blocking devices used in the furniture industry. The same blocks are used to lock the retractable power cord mechanism, the power connectors and the mirrors. The projector’s height, orientation and angle can be changed using another type of furniture metal support, the one used for hanging lockers etc. on the wall and the whole projector system can move on a rail for adjusting the display area.
7.  Dirt and scratch-proof compliant and projection surface.
Vellum is rather good as a projection surface and silicon can be rolled to it providing nice blobs. The biggest problem is that it wrinkles; it is susceptible to water damage and gets very dirty in no-time. The laminating process can help but laminating foils are usually rigid and have a lot of friction. We have chosen 2 additional layers of adhesive films on top of the vellum, The first one is a semi-rigid plastic material and the second is a thin low friction matte film. The combination of these 2 materials hardens the vellum, still allows for great blobs and protects it from environmental damage. The matte foil also helps with projection since it reduces the “washed color” effect of the vellum. Since these are self -adhesive foils the surface can be glued to the acrylic under the aluminum rails housing the Leds, preventing the displacement of the foils in time. The last surface is also very friendly to touch and drag operations are smooth.
8.  Custom made computer case
There was not enough space to put the whole computer inside the table (projector path occlusion). We built a wood support for the motherboard, the HDD and the power supply. This reduces heat accumulation, takes up a small space and no other power hungry components such as dvd-roms or additional case fans are needed. The “case” has shock absorbents, as many of the other vibration-prone components (the mirrors, the projector etc.). A wireless network card was installed so the table has internet access. In case of maintenance or debugging a wireless keyboard and mouse are also available.

Problems and observations

A large and tall box is subject to a lot of vibration. We have hardened the edges with L-shaped profiles to reduce this effect, but it’s still present when a strong touch occurs.  Due to the thickness of the acrylic (8mm) and the large display area, sagging could have been a problem but the acrylic is sandwiched and has an 8cm base on all sides therefore it does not bend under normal pressure.
Brake wheels are nice but they will not hold the table in place (because the wheel axis is not concentric with the wheel, the table can still spin around) thus the need for plastic feet when the table is on display.
Mirror alignment is probably the worst part. Working with large mirrors (2), a mm displacement on the first mirror can add up to 2 cm on the display. A lot of time has been spent on this.
We still don’t have FS mirrors, but by carefully aligning the mirrors the ghosting effect is visible but not bothering
We keep the tracking speed at 75fps. The system can handle more but at 75 the speed is good enough and the lower the fps the better the blob clarity since more light can be captured by the ps3 eye.
It’s heavy … even the box by itself needs some serious manpower when you have to move it up the stairs rasberry

We’re hardware maniacs so the software part is still in progress. We do have 1 medical application and 2 electrical engineering apps in the works.

We sincerely thank the NUI Group Community. This project could not have existed without the work of so many multitouch enthusiasts. We hope this contribution will help others in building their devices.

If anyone needs more information, photos or details regarding the building process or the materials feel free to ask smile

The VISION DECK team.

Pics to follow

The VISION DECK

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Internal Components (still some wire management needed, but it will always be in beta stage rasberry)

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Close-up of the components

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VD in action smile

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We have access to a high resolution thermal imager so we could analyze the heat dissipation with our ventilation system. The first pic shows the temperatures with the fans on. Top right the projector lamp, bottom left the video card

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Second thermal vision photo is without the ventilation on. The temperatures go skyhigh at over 50 degrees (in only 10 minutes of testing)
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And finally the design concept for the logo smile

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 26 May 2009 05:49 PM   [ Ignore ]   [ # 1 ]
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Wow amazing work! well done.
Could you give us more information or a source for the adhesive plastic films that you used?

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Posted: 26 May 2009 11:24 PM   [ Ignore ]   [ # 2 ]
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Awesome Box. That’s what it is. Just plain Awesome.

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due to the graphic Nature of this program, User Interaction is advised.

And remember gentlemen, day spent not making money, is a day wasted spending money.

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Posted: 27 May 2009 12:25 AM   [ Ignore ]   [ # 3 ]
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Well Done. I’m also interesting to know what type of film you used. I noticed after time with some films they start to bubble from the heat. But it looks like you ventilation system will help that out.

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chris szadkowski
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Posted: 27 May 2009 02:23 AM   [ Ignore ]   [ # 4 ]
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We have access to a high resolution thermal imager

did you use it for finger tracking ???

Can you take pics of your fingers on the surface with this cam ?

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How many touches can you simultaneously perform ? 
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Posted: 27 May 2009 02:30 AM   [ Ignore ]   [ # 5 ]
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stunning design all arround…

loving the thermal scans hah!

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Posted: 27 May 2009 11:28 AM   [ Ignore ]   [ # 6 ]
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Thank yousmile

This project has taken alot of time so we really appreciate the positive feedback rasberry

@grmcom, szadkowski:

We actually started to “hit” the sign and media advertising shops. We touched alot of materials until we decdided for what we have. I don;t think they are brand names but I will look into it. The ideea is to cover the vellum with something that protects it from wrinkleing and offers a smooth surface. THis is why we chose a mixture of 2. Plus all foils are self-adhesive at any shop (transfer foils, films for plotting letters, matte and mirror films, they should be readily available almost anywhere).

There is no significant heat on the acrylic surface so no air bubbles or other undesired effects. The tricky part is to glue it with the adhesive side down so that you don;t have any air gaps or wrinkles in it. It takes a bit of practice but with care it can be done.

@jimihertz:

No, the thermal imager can not be used for finger tracking. First of all they are usually designed to capture still heat pictures and even if they could do movies having a 20.000 Euro Thermal cam instead of a PS3 will definately hurt rasberry The whole project was made from pocket money so…

The second reason would be that infrared radiation at that wavelength (8.4 microns) can not pass through plastic or glass. It’s perfectly opaque (or even reflective). It’s a good thing since windows are installed for keeping the heat in/out.

I made a few thermal pics just for fun to show you what I mean

@christian:

Thank you, the pictures don’t do it justice rasberry and yes, thermal imagery is alot of fun smile

Since I got a few PM’s for some clearer pics I’ll just post them here

A thermal image of a user interacting with the VISION DECK. As you can see the plexiglass reflects the heat and acts as a mirror

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Another image with a piece of acrylic not allowing heat to pass

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The directional cooler vents on the bottom of the table

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A sharper picture of the internal components (lots of dust since it’s always being tested)

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 03 June 2009 01:03 AM   [ Ignore ]   [ # 7 ]
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For those interested in the types of films and foils we have used on the Vision Deck, the top layer (low-friction) is made by ORACAL (http://www.oracal.com/). They make all sorts of foils and laminates, the one we have used belongs to the 441 series, item 49 -matte windows foil (not sure that the numbers are correct in all countries). The best thing though is to test foils by hand since you can get a good sense of the composition and dragability of it.

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 25 July 2009 12:34 PM   [ Ignore ]   [ # 8 ]
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superb!!!

how did you get the mirrors aligned so well?? you said it was tough… but any tips to start of with....?? and u placed the projector vertical… aren’t there any disadvantages with it??? can i do the same with a DLP projector....? Mine is a BENQ 511+

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Posted: 10 August 2009 02:02 PM   [ Ignore ]   [ # 9 ]
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I answered the questions about the mirror positioning in the other thread (http://nuigroup.com/forums/viewthread/6470/). With a good ventilation there are no disadvantages of using the projector in a vertical position. Actually, as other members have discovered it cools even faster. Our test projector was also a DLP one so no worries as long as the airflow is taken care of.

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 25 November 2009 05:40 AM   [ Ignore ]   [ # 10 ]
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Very cool looking table.
Good idea to use aluminum pipes to get airflow where you want.

Will be looking in to this post as a reference for my own project, since it’s about the same size as my design.

Please do keep adding features and posting them on the forum.

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Posted: 25 November 2009 05:50 AM   [ Ignore ]   [ # 11 ]
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Ty for the interest in our VD smile

Well, we are currently exploring new ways of touch sensing so the Vision Deck project is in the background these days. I will repost here whenever significant changes/upgrades are made. In the meantime feel free to ask here anything that might help you implement your project faster and I’ll do my best to respond quickly.

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 25 November 2009 06:04 AM   [ Ignore ]   [ # 12 ]
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nice job
how long did it take you for the case
Tim

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Posted: 25 November 2009 02:22 PM   [ Ignore ]   [ # 13 ]
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Hi Tim smile

Actually the case was the easiest thing to build. We calculated the needed dimensions and bought a large chipboard plate (it’s cheap rasberry) and had it precut to our needs. The rest was just some furniture work to create the enclosure and drill the ventilation holes. It just took a few days. The tricky part was the top frame that is made out of 2 layers and can be detached. it’s a chipboard base for the acrylic and then a frame over the acrylic made from normal wood, sanded and painted. This way we have easy access to the acrylic and the LEDs.

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VISION DECK, FTIR MULTI-TOUCH SYSTEM
Spectral analysis of Multi-touch IR LEDs and FILTERS

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Posted: 26 November 2009 04:16 AM   [ Ignore ]   [ # 14 ]
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Not only are the dimension the same, the concept of your table’s top is also what I’m going to do.
I posted some designs in this thread.

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Posted: 28 December 2009 03:56 AM   [ Ignore ]   [ # 15 ]
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Hello
Thanks for the great information. I want to do something similar to your project too!! Since I write software for a living, and have built many computers and servers, and worked with many other technology. I am very comfortable with most of the tasks that it will take to make this project.

grin HOWEVER… I had a few questions for you about the areas I have never really worked with before.

1. Can you clarify what kind of mirrors you used. And where to acquire them.

2. Can you explain the part about the Compliant and Projection surface in more detail, and where to acquire such things: refined Tinkerman’s technique + Vellum +semi-rigid transparent adhesive foil+ low-friction matte windows film

When you say you used a refined Tinkerman’s technique, what area(s) did you refine?

THANKS SO MUCH FOR ANY ADVICE!

PS
EDIT: One other thing I am not quite clear on...where exactly does the PS3 camera have to be located? In the dead center at the bottom of the enclosure? Or can it be located off to the side?

I am considering different options for camera,mirror and projector placement. I am looking at getting a good short throw projector. So I may just be able to shoot it straight up to the underside of the table top. Just depends on how tall I will need to make the box.

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