robot airsoft

[the609blues]

Im making a robotic airsoft gun for a school project and was wondering what the best sensors would be?

[ed1380]

what are you going to be shooting at?

[cooldog]

depends on the range

sort distance
sharp IR

long distance
motion sensor

[airman00]

depends on the range

sort distance
sharp IR

long distance
motion sensor

Im guessing he'll be shooting at certain targets he picks , and not shooting at the closest object

So you'll need image processing

You need it automated or are you controlling it

[ed1380]

if he's shooting people then he just needs infared sensors

[airman00]

if he's shooting people then he just needs infared sensors

LOL

im pretty sure its not gonna shoot every person... or is it 

please the609blues , more details

[GUmeR]

Stationary video camera and motion detection algorithm. Shoot at everything that moves! Till it stops!! Wohah!!
No Alien will pass through!!!

Stationary, because if it would rotate with gun, you would have to disable algorithm for rotating time. Also shooting vibration could trigger motion detection.

Of course you will have to calibrate whole system. So gun shoots were motion is detected. You can attach laser pointer to the gun and detect it via video input.

[the609blues]

I was planning on putting a target on top of a rc remote car at about 10-15 feet away and have it follow and shoot it. i was thinking pir sensors.

[airman00]

Follow a target?


So you should probably have the target emit IR light and have an IR camera target it

OR just have a regular camera target the target ( if its painted red or something)

[GUmeR]

I want to make sure about one thing. Will this gun be controlled by a PC computer?

[the609blues]

I want to make sure about one thing. Will this gun be controlled by a PC computer?

i want it to be autonomous

[airman00]

define the autonomous functions:

track a red target and shoot


AND

what is your experience w/ robotics and what is your budget

[ed1380]

I want to make sure about one thing. Will this gun be controlled by a PC computer?

i want it to be autonomous

autonomous yes, but computer controlled or mcu controlled

[the609blues]

What I really want to do is use motion sensors to track a moving object and shoot it.I dont really have a budget but nothing ridiculously high priced. I have built robots before but never have done the proggraming my brother has though. I just need to know what sensors to use or how to link it to a camera.

[ed1380]

IR leds on target and roborealm+webcam for robot

[SomeSaba]

I dont wanna sound like your mom here, but taking a gun to school no matter what kind (airsoft or not) will get u in deep trouble, do your teachers know u are doing this as your project?

[airman00]

IR leds on target and roborealm+webcam for robot

Or even easier :

red ( or maybe a specific color pattern) target with roborealm and webcam


Please post pics and documentation when you are done, this sounds pretty interesting
\Also how are you going to pull the trigger? A servo or solenoid perhaps?

[the609blues]

i think i will do that and for the trigger im going to use an electronic airsoftgun take the trigger off and use a leaf switch and a servo will hit it but if you have a better idea feel free to post it.

[ed1380]

wouldnt something like this be easier
http://www.rctankcombat.com/articles/gun-assembly/03Trigger.jpg

[GUmeR]

What for? Trigger in Air Electric Gun just closes (shorts?) 12V Circuit from battery to DC engine. Just put 12V to gearbox and it will shoot. I would recommend using electric relay.

[the609blues]

does anyone have an idea for the movement of the gun im planning on having the gun stationary so i need it to pan and tilt.

[SmAsH]

y dont u use servos....never used em myself but heard theyre good....have two so one goes up and down and one goes left 2 right...

[maverick monk]

automated automatic airsoft turet how-to, with IR
http://unconventional-airsoft.com/2003/11/16/an-automated-motion-sensing-airsoft-gun-turret/

not a full how to, but an idea

[SmAsH]

haha yea that does look extremely good for a sensor gun..but have a look at admins robots they track stuff. or maybe ask her to help you or tell you how to rig up the circuit that she used in the red tracking robot..

[the609blues]

After getting many suggestions on it i have decided to use pir sensors and using 1 servo to move it left and right(no up /down) im still not sure on the trigger but i dont need help on that. I do Have a couple of questions though.

1. How high powered of a servo will I need to turn the gun or how can i find  out.
2.since Im going to use pir sensors can i program them like the photovore ( If pirleft detects heat and pir right does not then turn left)?
3. If I can use the photovore type algorithm can i do if pir left and pir right = then shoot)
4.Will I need a servo controller
lastly do the pir sensors need to rest for thirty seconds or is this just something i heard.

If any one can answer these questions or help with my design its greatly appreciated.

[airman00]

After getting many suggestions on it i have decided to use pir sensors and using 1 servo to move it left and right(no up /down) im still not sure on the trigger but i dont need help on that. I do Have a couple of questions though.

1. How high powered of a servo will I need to turn the gun or how can i find  out.
2.since Im going to use pir sensors can i program them like the photovore ( If pirleft detects heat and pir right does not then turn left)?
3. If I can use the photovore type algorithm can i do if pir left and pir right = then shoot)
4.Will I need a servo controller
lastly do the pir sensors need to rest for thirty seconds or is this just something i heard.

If any one can answer these questions or help with my design its greatly appreciated.

1. Find the weight of the gun

2. the photovore idea i do not think will work very well( i may be wrong)   , you want something like this to track people http://www.robotshop.ca/home/suppliers/devantech-en/devantech-8-pixel-thermal-array-sensor.html
3. you can do it, but its not going to work well
4. No , just use a  microcontroller and have it give a pulse to the servo

Why use PIR?  Why not camera ? 
also, I believe that the PIR sensor uses special lenses inside, so you could change the lenses to change the width of the "view" of the PIR sensor.

Try the accuracy of the PIR sensor and try the tracking area out. The photovore idea may work! If it does I want to see some documenting, I might use the same design. 

[the609blues]

how would i do a camera without using roborealm

[GUmeR]

1. One strong (expensive) servo. Well mounted gun, so center of mass is on rotation axis. For 500g-1000g gun should work, but it’s more a guess, than calculation.

2. I very much doubt that any kind of ranged heat detection will work (other than professional thermal camera). In link it says it "can detect a candle flame at a range 2 meters (6ft) - unaffected by ambient light". Candle flame has tamp. is over 1600 Kelvin (1327 C). Human has 309 Kelvin (36 C). Background temp. in room is 293 Kelvin (20 C). Candle flame is small and hot on cold background. Human is quite big (compared to candle flame) and just little warmer than background.

If someone DID use IR to detect heat, please list exact sensor, link to documentation, price and effects.

I would suggest to mount IR transmitter on target, and 3-4 IR detectors on gun, separated by tiny walls.

3. If sensor 1 detects IR signal, rotate left fast, If sensor 2, rotate left slowly, If 2-3 sensors detect IR at same time, but 1 and 4 not, then shoot.

4. You can use one microcontroller for detection and controlling servo.

I suggest you first build sensors, write program and test it. Leave gun, trigger, power, servos for now. These problems are easy solvable. Sensors will be the most difficult and time consuming part.

You can program video processing by yourself on PC. I advise not to try use video processing on microcontroller. It's possible, but very very difficult.

If you want to use camera (IMHO best but most complicated sensor), connect whole gun to PC, and use some ready libraries (e.g. robotrealm).

[the609blues]

So pir sensors are out what else could i use but i have to do a presentation and there will be no computer present

[GUmeR]

I might be wrong. Don't discard this idea because opinion of only one person. Search for PIR robotic project on the net, post link if you find something interesting I would be very interested, if motion/heat/human detection could be done in this cheap and easy way. If many people suggested it, maybe they have some useful links. If not you can still try it by yourself.

I would like to stress out that I did NOT tested PIRs by myself.

I apologize for this misunderstanding.