Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: oldstudent on January 23, 2008, 03:22:47 PM

Title: metal detectors and colour recognition
Post by: oldstudent on January 23, 2008, 03:22:47 PM
Hi all, I am a new member and this is my first post.

I am a mature student tasked with designing my first robot.
I have never been involved with robots previously, and have very limited electrical knowledge.

I must stress however that I do not have to build this robot, just come up with a theory , and spec the parts. (thank goodness!!), and money isn’t an object

I just want to know if any of you guys had ever used a sensor than can detect a metallic object from 1 metre away.

What type of sensor and where did you get it?

Also a sensor to recognise colour from over a metre away?

Ideally the object would be “sensed” as it came into the field

hope you can help


oldstudent















Hope you can assist.

Old student





Title: Re: metal detectors and colour recognition
Post by: ed1380 on January 23, 2008, 05:59:50 PM
a camera for color recognition.

a modified metal detector (the kind old people use in the park)
or one from the airport
Title: Re: metal detectors and colour recognition
Post by: Bubbles on January 23, 2008, 06:22:18 PM
or one from the airport

yeah. just go down to your local airport and ask them if you could have one of their metal detectors  :P
Title: Re: metal detectors and colour recognition
Post by: frank26080115 on January 23, 2008, 06:27:17 PM
stud-finders with a pipe detecting feature
Title: Re: metal detectors and colour recognition
Post by: Soeren on January 25, 2008, 05:20:03 AM
Hi,

[...] and money isn’t an object

Then hire an engineering consultant for the job ;)


I just want to know if any of you guys had ever used a sensor than can detect a metallic object from 1 metre away.
[...]
Also a sensor to recognise colour from over a metre away?
First off, you need to define your targets a bit better, since there is quite a difference to detecting metal objects like sewing pins and eg. a bicycle and the kind (or range) of metals is quite important too, each metal has it's own properties.
Same with colour, is it a pinhead or a football you need to detect, how small differences in hue do you need, how many other objects will be in the vicinity etc.

When you have spec'd out your needs that way, your search for detectors can start.
Title: Re: metal detectors and colour recognition
Post by: oldstudent on January 25, 2008, 12:54:56 PM
thanks for the sensible replies.

i actually want to find a golf ball, (which will have a metal object inserted in it for this reason)
i want to find it within a metre.


Title: Re: metal detectors and colour recognition
Post by: airman00 on January 25, 2008, 01:57:01 PM
there are easier ways to find golf balls!

ill start off with some
RF
Resonance
Title: Re: metal detectors and colour recognition
Post by: oldstudent on January 25, 2008, 02:46:42 PM
ok, cheers airman
Title: Re: metal detectors and colour recognition
Post by: airman00 on January 25, 2008, 02:50:41 PM
so what method will you be using to find he golf ball ?

we can help you out with this!
Title: Re: metal detectors and colour recognition
Post by: oldstudent on January 25, 2008, 03:04:23 PM
i wanted to be able to "scan" for the metallic object. this will be the only metallic object in the vicinity.
i was going to mount the scanner on a rotating spindle, monitored by an encoder, to gain an angular position, then by knowing my postion and the position of the ball, i would know how much to rotate so i am facing it.

 the whole thing is theoretical i must add


Title: Re: metal detectors and colour recognition
Post by: airman00 on January 25, 2008, 03:08:00 PM
good idea , BUT

you could always put an RF emitter on it and find it that way

or just paint the golf ball red ( lol  , jk   :P)
Title: Re: metal detectors and colour recognition
Post by: oldstudent on January 25, 2008, 03:33:18 PM
i can have any colour ball i want if that helps at all!!!

does the rf emitter go in the ball and the scanner finds it?
Title: Re: metal detectors and colour recognition
Post by: airman00 on January 25, 2008, 03:46:23 PM
does the rf emitter go in the ball and the scanner finds it?


yes
something like this
http://www.mcmanis.com/chuck/robotics/projects/eelb.html
 (http://www.mcmanis.com/chuck/robotics/projects/eelb.html)
Title: Re: metal detectors and colour recognition
Post by: oldstudent on January 25, 2008, 04:14:09 PM
i dont understand, im sorry but i am not electrically biased in the slightest, i work in manufacturing, and am more mechanical

i understood about the 1mhz signal, but didnt understand how that would detect my ball. and when it did, is that when the LED lights up?


Title: Re: metal detectors and colour recognition
Post by: Admin on January 25, 2008, 07:36:20 PM
Quote
i wanted to be able to "scan" for the metallic object. this will be the only metallic object in the vicinity.
Quote
the whole thing is theoretical i must add
one word: RADAR
Title: Re: metal detectors and colour recognition
Post by: Soeren on January 26, 2008, 06:19:47 AM
Hi,

i can have any colour ball i want if that helps at all!!!
Then use a bright orange (neon colored) golf ball - they are available from golf shops and take a look at http://www.cs.cmu.edu/~cmucam/home.html (http://www.cs.cmu.edu/~cmucam/home.html)