Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: the609blues on January 02, 2008, 07:09:49 PM
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Im making a robotic airsoft gun for a school project and was wondering what the best sensors would be?
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what are you going to be shooting at?
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depends on the range
sort distance
sharp IR
long distance
motion sensor
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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 :D
So you'll need image processing
You need it automated or are you controlling it
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if he's shooting people then he just needs infared sensors
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if he's shooting people then he just needs infared sensors
LOL
im pretty sure its not gonna shoot every person... or is it :D
please the609blues , more details
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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.
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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.
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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)
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I want to make sure about one thing. Will this gun be controlled by a PC computer?
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I want to make sure about one thing. Will this gun be controlled by a PC computer?
i want it to be autonomous
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define the autonomous functions:
track a red target and shoot
AND
what is your experience w/ robotics and what is your budget
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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
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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.
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IR leds on target and roborealm+webcam for robot
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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?
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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?
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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.
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wouldnt something like this be easier
http://www.rctankcombat.com/articles/gun-assembly/03Trigger.jpg
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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.
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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.
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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... ;D
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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
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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..
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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.
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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 (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. ;)
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how would i do a camera without using roborealm
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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).
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So pir sensors are out what else could i use but i have to do a presentation and there will be no computer present
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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.
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actually i think you can do body heat tracking with PIR sensors IF they have the correct lense ( not the Fresnel lense they have now)
google Fresnel lense to read about it
if i can get free samples of PIR sensors tell me where, and i will do tests. It is possible!
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what about the pir on http://www.futurlec.com/PIR_Sensors.shtml the second 1 down and using two of them?
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hmmm
the problem is I don't know how far the detecting range is, and also im not sure if it can detect human body heat without a fresnel lense
I would get a few of each sensor and try them out. But remember , you need to amplify the signal from the sensor!
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i found this gun http://www.hobbytron.com/GreenGasAirsoftPistolSilencerSilverBladeTrinityStyleGGHGX107NS.html how large of a servo do you think i will need.
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the sensor with the fresnel lense on that page says it is better for human body heat tracking.
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thats a gas airsoft gun
find an electric one , i would get semiautomatic one
this project is very interesting
feel free to email me about it at anytime ( [nospam] [email protected]) remove nospam from the email, dam spam bots
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hs-311 servo
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whats wrong with a gas gun also i found this link which was kind of helpful.
i think i might use the 2 of the 6.90 one from futurlec and put a wall between them.
what are your thoughts
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what about this gun http://www.hobbytron.com/ElectricJamesBondAirsoftGunBC2030B.html
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the sensor with the fresnel lense on that page says it is better for human body heat tracking.
Interesting , though i think that because of the fresnel lense it gets spread apart,
ill do some more research now
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yea that gun is fine , though it can only hold 14 bullets in its magazine, you might need to make it a bullet hopper
electric is the best since there is a motor in there, so you would just switch the motor on with a MCU and override the whole trigger
i would get a servo with at least 55 oz of torque , just in case , since you'll prob add on more stuff to pan later
this servo is perfect and probably has more than enough torque http://www.servocity.com/html/hs-475hb_super_pro_bb.html (http://www.servocity.com/html/hs-475hb_super_pro_bb.html)
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I think the Fresnel lens will work as long as i put a small wall between the two sensors. I have 2 more questions how do i control the guns motor with the micro controller and will the recommended servo be fast enough to follow a human.
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umm figure out the speed you need to follow a human first, then check to see how fast the robot can rotate
in the electric airsoft gun there is a motor. So get a transistor or an H bridge and have the microcontroller switch the transistor which will turn on the motor. THen have it go for like a second at a time for individual shots, etc....
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I don't see you doing this without a camera . . .
Also consider the CMUcam or AVRcam.
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They got something like this:
[youtube]http://www.youtube.com/watch?v=Al-4_1kUBLc[/youtube]