Line sensor

On Sat, 29 Oct 2005 20:36:11 +0200, "Tom"


One possibility: http://www.jrobot.net/Projects/AVRcam.html

I haven't tried it, but it's on my to-do list.

--
Rich Webb   Norfolk, VA

If vision is a possiblility then check out this online tutorial on one
way to use vision in a mobile robot to follow a line:

http://www.roborealm.com/tutorial/line_following/slide010.php

Works well for all sorts of lines ... even broken ones!

Thanks for the inputs.

I can see that some type of camera based system would be a good approach.

But the programming gets a bit complex, so I was planning for a solution
with LEDs and photo transistors.

Any suggestions on a stable system build that way?

/Tom

Have you looked at the Hamamatsu P5587 chip?  They're about $2 US, and need
some resistors and capacitors, but they reliably detect white vs dark
stripes within an inch of range.

Check out

http://www.acroname.com/robotics/parts/R64-P5587.html


--
Mike Ross

Instructions said Win98 or better, so I used Linux.

You could try tweaking this tho' the aim was a few millimetres from the
surface for best results.... www.minisumo.org.uk/EdgeDetection.html

placin a few of these side by side you should be able to detect where your
line is in relation to the sensors.

Best regards,
colin

www.minisumo.org.uk/forum - a new forum for minisumo in the UK

   The line could be painted with a magnetic medium such as copier toner in pva
glue;
as well as being optically reflective. Just another idea.


    The light source should be modulated at a particular frequency so that only
the sensor
will detect it; therefore other flashes of light reflecting off the surface will
go undetected.
This technique has been used extensively for T.V. remotes where the distance has
to be
several metres between source and detector!
   Cheap plastic lenses are available from electronics suppliers to focus the
target onto
the detector better and are filtered to mainly allow Infra-red light through.
This technique has been used for security door break detector beams.


   Use the above tried and tested methods and go searching on the Web for the
best offers.


   It`s a basic building block. Through practical use you will discover its
pitfalls.


   The pattern in which they are placed could be considered carefully to reduce
components and circuit complexity.
   Another thought is that only one sensor is utilised and a moving lens or
mirror
scans the line.


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Ashley Clarke
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