Society of Robots - Robot Forum

General Misc => Misc => Topic started by: zeusent on April 16, 2010, 08:16:06 AM

Title: IR invisible surface
Post by: zeusent on April 16, 2010, 08:16:06 AM
Ok. So I've register into a sumo robot contest and I've even won 3rd place at the local event. I'm going at the national stage now and I want to somehow improve my robot. I've searched Google for a full day and I cannot find anything about this.

Is there someone who know if there is something I can use to 'absorb' the IR rays of the others robot so they cannot see me anymore? Or at least disrupt them to get the same effect.

Any help would be really appreciated.

Thanks,
Mickey
Title: Re: IR invisible surface
Post by: SmAsH on April 16, 2010, 08:28:18 AM
Hmm, this sounds a bit like what admin was onto with his stampy robot.
http://www.societyofrobots.com/robot_sumo.shtml (http://www.societyofrobots.com/robot_sumo.shtml)
Quote
IR/LED Defence
Two popular methods of robot sensors are infrared emitter/detectors and photoresistors with reflective LED's. To counter these sensors, you need to coat your robot in an IR/visible light absorbant paint. Make sure the paint has a rough coat, as a shiny coat is more reflective. I used black acrylic paint, but I didnt test it to see how well it works. Another popular sensor used is the Sharp IR Rangefinder. This sensor is significantly more immune to surface color, but it will still have some decreased accuracy.
Although not entirely full proof, it will have some effect on the opponents detectors.
Title: Re: IR invisible surface
Post by: zeusent on April 16, 2010, 08:36:32 AM
I've read the article before. I've painted my robot in black acrylic paint already but there was less (or none) effect agains the SHARP IR RANGE FINDER most of the competitors used. I need to find some better defense system. Is there a way you can 'consume' the IR rays so they won't get back to the opponent's sensor?
Title: Re: IR invisible surface
Post by: waltr on April 16, 2010, 09:20:57 AM
Another technique would be to reflect the opponents sensor probing in another direction so that he can't see the reflected beam. Look an pictures of the Stealth bomber and fighter.
My robot's Sharp distance sensor has a really hard time seeing chrome from an angle.
Title: Re: IR invisible surface
Post by: Cristi_Neagu on April 16, 2010, 10:37:54 AM
Remember that glass acts as a mirror for IR rays. The disadvantage being that glass is brittle.
Also, you could have infrared lights pointing all over the place, confusing the other bot.
Title: Re: IR invisible surface
Post by: amando96 on April 16, 2010, 12:10:31 PM
you could have loads of IR leds on the outside, flashing, so the other bots would ALWAYS be detecting something, and doing their ''attacking program'' wich would give you time to hit them from behind  ;D
Title: Re: IR invisible surface
Post by: Cristi_Neagu on April 16, 2010, 12:54:19 PM
About the "use leds to confuse the opponent" approach: if you just cover every square inch of your robot with leds, the other bot might ignore everything else and just go for the biggest light source around, which is your bot. You should test these things and see how they go.
Title: Re: IR invisible surface
Post by: Soeren on April 16, 2010, 04:58:25 PM
Hi,

To confuse a Sharp IR Ranger, just carry an array of IR LEDs of the same wavelength and modulate at the same frequency as the Sharp does, it will then see it as up close even when it's a fair distance away.
Better make sure their US don't work either, and if you really want to be chickening out of a fair match, hit the opponents 'bot with a hammer or zap it with a stun gun when nobody have their eyes on you ;)

Or, you could build a better 'bot that could win fair and square.
Title: Re: IR invisible surface
Post by: Cristi_Neagu on April 16, 2010, 05:10:18 PM
zap it with a stun gun

You know, using static electricity to fry the internal electronics of a bot would be an interesting battle bot weapon. But, let's hope no one will ever build one. It's not fun when someone fries hundreds of dollars worth of your electronics, not mentioning  the work hours involved.
Title: Re: IR invisible surface
Post by: zeusent on April 17, 2010, 01:00:06 PM
Remember that glass acts as a mirror for IR rays. The disadvantage being that glass is brittle.
Also, you could have infrared lights pointing all over the place, confusing the other bot.

What about my own sensors? Wouldn't it get confused by the same IR lights?
Title: Re: IR invisible surface
Post by: Soeren on April 17, 2010, 06:21:08 PM
Hi,

What about my own sensors? Wouldn't it get confused by the same IR lights?
Synchronize. Just like the MGs in old war planes that shot in between the propeller blades. Without the synch, they would have shot themselves down.
Title: Re: IR invisible surface
Post by: Cristi_Neagu on April 17, 2010, 11:18:55 PM
What about my own sensors? Wouldn't it get confused by the same IR lights?

Go ultrasonic, or, as Soeren says (i think), use some kind of glass blades that spin, and do the sensing in between blades.
Also, you could still use IR sensors. You would just need to slightly lift your sensor over the glass and it will work, whilst presenting a very small target for the other bot. And you could still add a lot of IR lights on the back of your bot lighting up the walls to confuse the other bot. 
Title: Re: IR invisible surface
Post by: corrado33 on April 18, 2010, 10:03:47 PM
Hi,

Synchronize. Just like the MGs in old war planes that shot in between the propeller blades. Without the synch, they would have shot themselves down.

I have to admit, I saw that type of synchronization on a show called Time Warp, and it was amazing...  I couldn't believe it.  Then they turned the sync off, and the propeller got shot to all heck! 

Anyway, I agree with Soeren to build a better bot!  But when he said syncing, I think he meant, you fire your detector for an second, find out where you need to go, then fire your distraction IR lights.  Repeat a bunch of times.  etc.  I think something like that might work.

Or, you could use IR reflecting material and build the outsides of your bot at a 45 degree angle.  So any IR that hits it will go straight to the ceiling. 
Title: Re: IR invisible surface
Post by: zeusent on April 19, 2010, 03:24:31 AM
Or, you could use IR reflecting material and build the outsides of your bot at a 45 degree angle.  So any IR that hits it will go straight to the ceiling. 

Any idea on what that material might be? Simple glass would do it? What about a mirror? Isn't that better? Any suggestions?
Title: Re: IR invisible surface
Post by: richiereynolds on April 19, 2010, 05:13:59 AM
Shooting your own IR through glass propeller blades, sounds amazing, that I'd like to see!

Though not quite as cool as that episode of Malcolm in the Middle where Hal makes a robot that fires a stream of bees at the other robot's operator, now that's a weapon!
Title: Re: IR invisible surface
Post by: corrado33 on April 19, 2010, 10:15:29 AM

Any idea on what that material might be? Simple glass would do it? What about a mirror? Isn't that better? Any suggestions?

Eh, I don't know, experiment and see.  Take some materials, stick it in front of your TV remote control, and see if the TV changes channels.  Then try to reflect the IR off of the material to change the channel. 


You know, using static electricity to fry the internal electronics of a bot would be an interesting battle bot weapon.

It's illegal I believe.  If you're talking about bot wars and stuff, I believe there are regulations that don't allow weapons like projectile weapons, flame throwers, or anything to do with electricity.  It'd be too dangerous for the fans watching and too easy to win (in the case of using electricity to fry the components).  Well, of course you could build your robot to not be grounded or be built of a non conducting material, but still... it just wouldn't be good.


Title: Re: IR invisible surface
Post by: Comrade117 on April 20, 2010, 06:00:15 AM
Yes, electric weapons are ilegal. In battlebots you are allowed to use only axes, blades, spikes and so. However weapons such as railgun and gauss gun are not restricted, but are too big to use in battlebots.
Title: Re: IR invisible surface
Post by: Rick Brooks on May 01, 2010, 07:01:21 AM
One of the above suggestions does work quite well, but I've never seen a robot successfully implement the strategy.  Well, one of my competitors built a robot that drastically reduced the effectiveness of IR sensors, but never completed the robot enough to enter a competition.

       Rick Brooks
Title: Re: IR invisible surface
Post by: Comrade117 on May 06, 2010, 03:54:02 AM
Eh, I don't know, experiment and see.  Take some materials, stick it in front of your TV remote control, and see if the TV changes channels.  Then try to reflect the IR off of the material to change the channel. 

I did. Problem is: TV remote control has not sharp IR. I did not find any common materials that do not reflect IR, but, surfaces with many angles slightly reduce detectable range.
Detectable range of round stone was ~2.5 meters, but detectable range of cracked stone was ~2.2 meters. (angle of remote control was not the same, I tried this changing angles)

Remember that this was not sharp IR, so this way to reduce detectable range should be much more effective against sharp IR  8)