problem statement

[gaurav.p]

hi,
i m building a bot where it will follow a line and then it will identify the objects which are placed 20cm from the line on either side if the line.the objects are of two types ,one is white and the other is Grey and the robot needs to knock down the grey ones.so i m going to use ir proximity sensor for identifying objects and i m planning to use  a color sensor to identify the type of the object.so is it foolproof to use color sensor to differentiate.
i had a link of a tutorial on the PCB layout of the 50$ board.it will be gr8 help if someone can give the link of it .i can't somehow find it( don't know why)
i hav also thought of mechanism of knocking down the objects.well it will be like rack and pinion type of mechanism where instead of gears i will use velcro.

if there is some addition or something else please let me know.thanks in advance

regards,
-gaurav

[Soeren]

Hi,

[...] the objects are of two types ,one is white and the other is Grey and the robot needs to knock down the grey ones.so i m going to use ir proximity sensor for identifying objects and i m planning to use  a color sensor to identify the type of the object.so is it foolproof to use color sensor to differentiate.

White and grey are the same "color"!
If you have an opportunity to "read" one of each immediately before your run, you could use a LED + light detector setup to find the amount of "greyness" (light reflected) and differentiate from a percentile median calculated from that.

It would be so much easier to detect the difference between eg. red and green (still without a color sensor).

i had a link of a tutorial on the PCB layout of the 50$ board.it will be gr8 help if someone can give the link of it .i can't somehow find it( don't know why)

Perhaps the one by Webbot in this post: http://www.societyofrobots.com/robotforum/index.php?topic=3292.msg25198#msg25198?

i hav also thought of mechanism of knocking down the objects.

What shape, size, weight, material etc. are the objects?

[...] instead of gears i will use velcro.

Sounds a bit weird to me, but whatever works... 

[gaurav.p]

i didn't get it how is white and grey the same colour .i hav a ir proximity sensor
http://thinklabs.in/shop/product_info.php?cPath=37&products_id=50&osCsid=c5cd5d27b64fcc221b3a6201ab88bf25
i can caliberate it so that it can only detect grey and not white.
thanx for the link
the object hav 2.5 inches of width and 1.2 inch length and height of 2.5 inch.so i will knocking the normal to the width .
using velcro sounds weird but i m trying to find gears and i hope i will soon get it and i also want a mercury switch(from where can i get it _cheap)
i will soon post the cad of the robot . the link of problem statement is given below
http://tricks.co.in/championship.php

-gaurav