Here's how to do the math and the parts list for the Waterloo Labs FPS with Real Guns video.
I like this demo quite a bit. I would love more information on this. I have an interest in electronics but no formal education. I also have an interest in training Tennessee SWAT teams and I instantly recognized how this could be put to use in a training situation. There is not a lot of money to train SWAT teams so we often rely upon doing everything ourselves. Something like this could really raise the quality of the training quite a bit if we can do it cheaply. I know how to program and the set up appears to not require a lot of skill at electronic manufacture. We use simulators which are similar to Airsoft guns. I am curious how accurate it would be to place accelerometers on metal sheet and measure that way. Is the speed of propagation of the mechanical wave through material important? I would imagine it would be faster and more sharply defined with metal. Your drywall example would degrade the signal after a few dozen shots. We would want something that would remain accurate for hundreds of shots.
I love your site and I am so glad to see people having fun inventing things. We need more of that spirit in this country. What you play at eventually can be put to practical use.
Thanks for watching the video! We're glad you enjoyed it. While we were presenting this at a couple of different occassions we heard of gun ranges that use this technique for just such a prupose. What they tend to use is a piece of rubber. As the bullet penetrates it the rubber stretches and then after the bullet passes through it shrinks back again so the actual size of the hole is miniscule. This lets you use the sheet for much longer than a piece of drywall of sheet metal.
We also actually found that the speed of propogation in the material is divided out in the math we used so it was irrelevant.
Being the Jr. Mad Scientist that I am a lot of discussion has already happened on this. For SWAT training we often use buildings that aren't currently being utilized such as school buildings during the summer months. The weapons we use are simulators that would be familiar to civilians as Air Soft type guns - though their look, function and weight is identical to police side arms. It's just a difference in impact force. Having portable setups would be ideal. Which got me to thinking. You typical scenario places people in various locations in the training site. What you can't predict is the path SWAT teams will take (building search and clear is an art form). However if you have a network of wireless computers set up with sensor assisted, white painted sheet metal, projectors and speakers, you could monitor the progress of the team remotely and key any video you want. You could have any combination of armed agressor(s), civilians and environmental concerns. Some really challenging situations could be represented.
I've never put electronics together but these videos have me really inspired. A friend put together a reprap which just adds to my level of interest. Plus there is a real need. I would love to see local, small town police teams get higher quality training. I think something like this makes a lot of sense. I can see other uses as well. One thing that is hard to train for safely are reactive targets. A large enough surface and bright enough projection at distance could make for a good simulator. Perhaps combine laser show technology with this to draw the targets onto the surface and give accurate shot placement. There are so many ideas one could extrapolate from this.
great ideas.. we would love to see this system get out there. Let me know if you have any technical questions.
My name is Wilson Guerrero I'm from Colombia, please forgive my english I'll do the best I can to make some sense with my text, currently I'm developing a videogame with support of a government educational institution also with a small team of people, at this point we are in the first approach to "assemble" the screen but we found some small problems, the first one is that we could not get the USB 4432 instead we only found (in this country) the USB 6xxx (sorry can't remember the full number right now) the technician said that he will deliver those signals in the PC and from that point the rest is up to us, so the first question is: will the programs work with this type of USB? also the accelerometers we have are MMA7260Q: XYZ AXIS ACCELEROMETER ±1.5g/2g/4g/6g wich the technician claims are really sensitive, I know nothing about electronics cause I'm a 3D modeler, so second question: will this components lead us to a full working screen like yours? and last question: does this technology have any kind of commercial restrictions? this is really important as the project is completly profit oriented, so I will be checking this site hoping for an answer, thanks for your time and if you want ANY info about our project or equipment just ask for it I'll be glad to send it.
The 6008 or 6009 can be used to do triangulation based on microphones or accelerometers but you will see a major difference in accuracy. The reason we used the 4432 was that is sampled all channels simultaniously. Since we knew the signals were measured at the exact same time it made it easy to do delay calculations and triangulate the impact. However since the 600x multiplex all of the analog inputs through one ADC there would be small offsets for each signal. The 6009 can only sample up 48KHz (diveded by the number of channels) compared to the 4432 100K on all channels at once. Long story short, you can build a cheap triangulation system using microphones (or acceleromters) and a 600x but it will not be accurate for small (screen sized) distances, however it would be adequte for a much larger system like this one. http://www.ni.com/pdf/csma/us/360915a1.pdf