The autosentry breaks the first law of Asimovs three laws of robotics: A robot may not injure a human (...).

Hooked to a laptop with a high speed videocamera this monster can automatically track persons on a sup'air paintball playfield and shoot at them. This includes compensation of the paintballs trajectory, calucation of the players speed and compensation to hit them even if they are far away and fast moving.

It's done via a simple frame-to-frame comparison. The resulting grey-scale picture (dark=no movement, bright heavy movement) is mathematically reduced to the least possible number of boxes that cover all bright areas. These boxes are compared (only those that are near to each other), and by the distance a movement-vector is calculated. Because of the framerate, the movement-vector is only a small fraction of the players real movement vector. Thus this vector is scaled, it grows very fast, overshoots the real margin, but quickly adjusts to the real movement vector. By doing this the system can react very fast on movement, and the overshooting of the vector results that the gun is shooting some meters in front of the player. Because paintballs travel very slowly (280 feet per second) they will reach the targeted point just by the time the player has reached the point, hitting him. A very nice sideeffect that i had to do no extra-calculations for. The autosentry selects the biggest object it can see moving, fires for 10 seconds, selects the second-biggest object, fires for 10 seconds and so on. Areas that have a steady but too slow movement (like the trees you see on the screenshot) are filtered out by simply counting up a variable everytime something moves. After a special treshold is hit the box is no longer taken into account. The servos are controlled by a microcontroller (hooked to the laptop via rs232) that takes care of soft start/stop, zero calibration, fire and so on.

There are some tricks you can fool this system, for example by a very fast start and an abprupt stop. But if you really play paintball, you have no time to fool around like this to trick the autosentry. By the way: The first time someone hit the videocamera, the cmos-chip of the sensor was teared from its circuit board by the g-forces resulting from the impact. Wow.

The mechanics for version 2 (below, version 1 was built around 2000) are used for a
different project and are now out of my reach. The main intention was never to shoot
at people, this is only a sideeffect (a "party gag", but a very cool one if i may say so).

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[ p0rk | 13.07.05 15:28 ]
Wow. I want one for my room to keep my little sister from nosing around ;)

[ Stewie | 13.07.05 21:37 ]
I say, excellent work chap. Yes another device to assist in my ultimate goal of world domination.

[ Foo | 13.07.05 23:29 ]
What make/model camera was used? Was other special hardware used to do the image capture?

[ SovietHunter | 14.07.05 00:00 ]
i cant imagine improving on this and attaching it to a tank...

[ Bob7k | 14.07.05 00:06 ]
Ithink it can be used by any camera as it compares the frames so i guess you can use any video-in device

[ Suckit | 14.07.05 01:15 ]
It really sucks when you come across something as badass as this and the genius behind it does not share the wealth. Sourc code and full schematics please!!

[ Zachary Hodgson | 14.07.05 02:11 ]
Yes! Please, full schematics and source. I would love to build one of these for myself.

[ Charlie | 14.07.05 02:59 ]
You seriously should release the schematics and code, you might also be able to make some money by selling these to big paintball fields. Im sure TONS of players would love to test their skills against a machine. If you would be interested you could try contacting they would probably be willing to set something up at one of the upcoming events.

[ SanitysEdge | 14.07.05 03:50 ]
You should add another camera for depth.

[ alex | 14.07.05 04:19 ]
wen r u going to make a diy part of this???

[ Eman | 14.07.05 17:43 ]
Very cool gun!! I want one, but I'm really too busy to figure it all out myself. Could you build one for me too? I'll pay for the shipping. You gonna help a brother out, or are you gonna be a jerk about it and expect some kind of "reward" or "compensation" for your investment of time and effort?

[ Mike Kelly | 14.07.05 18:05 ]
I'd like to see the paintball gun mounted on the assembly. This is really cool.

[ Dru | 15.07.05 20:09 ]
If you can mount a paintball gun, you can mount a real gun. Wonder how long before you are visited by the authorities?! For military purposes it could detect enemy movement and take them out if one chooses. Great work mnt!

[ ryan | 15.07.05 22:29 ]
a .50 cal on that thing would be a fearsome sight indeed. or an AGL (check out heckler & koch's website to see it, it's a scaled up browning .50 cal that shoots 40mm grenades)

[ randomguy | 16.07.05 03:23 ]
Where's the video of this thing in action?

[ klepka | 02.08.05 13:13 ]
he said the sentry is now out of his reach, thus no video

[ alkzy | 14.08.05 08:11 ]
coolest shit ever

[ sirus | 23.09.05 05:51 ]
I would love a copy of this program or better yet the source. I have a very nosey brother which isn't slowed down much by barbed wire around my door nob

[ Tetro | 19.12.05 20:33 ]
Why should he share the knowledge, when he can earn money? That is what I would do, you wanna know? You cross my palms with Silver :)..

[ Bob7k | 27.08.06 06:07 ]
Do we even have any evedence of this in action? i call this as crap, he wont relese the code be cause it doesnt exsist, he doesnt have any videos because it doesnt exsist, send me the source code! ohh yea, no its not real, dont even bother with this fake piece of crap, i need hard evedence, a video via webcam inorder to believe this is real.

[ Emon | 16.09.06 00:27 ]
Er, I see no reason for this to be fake. Motion tracking is quite simple. Tons of people have made these for both airsoft and paintball.

[ Pete | 17.10.06 14:34 ]
Bob7K: First insult him, then want him to send you the source? Moron.

[ mnt | the codeninja, 05.11.06 17:32 ]
You have to figure that out yourself. I'm currently experimenting with particle swarm based optimization, with fantastic results.

[ maxi | 05.11.06 18:17 ]
Ey mnt, Samsung baut jetzt auch sowas. Allerdings mit caliber 5,5mm ;)

[ Terranian | 18.12.06 04:37 ]
Great contribution to human kind

[ awesome | 09.05.08 01:46 ]
i want one so bad!!!

[ LPR | 03.07.08 11:24 ]
Does anyone know where I can buy this turret?

[ Renier | 15.11.08 17:22 ]
Did you vere go into production with this?
We bould training systems for L&E units we might be interested to take these into production.
PM me at gunpro at

[ Anderlan | 24.12.09 15:06 ]
So, it's like a hunter-seeker? It will not strike if you move very slowly?

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