Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: s80ts0465 on November 27, 2007, 08:40:37 AM

Title: better proximity sensor
Post by: s80ts0465 on November 27, 2007, 08:40:37 AM
I'm thinking about to use the proximity sensor to create an autocharing robot.
My intention (suggested from many articles i've found on the net) is to use an IR TX from the charging station and an IR RX on the robot.

I've read many different configuration that are possible to implement, but i'd like to know which is the best configuration you've tryed and actually using.

I'm oriendted to the Panasonic PN4602 as receiver.

So what is your prefered configuration??

Bye Ste
Title: Re: better proximity sensor
Post by: Robotboy86 on November 30, 2007, 10:54:13 AM
well you could mimic the current techonology in modern avionics.

http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/gbng/ils/

thats a pretty good explanation of what it is.  Although instead of trying to do this with expensive technology you could use two IR beacons on the station, and a simple IR camera on the robot.  Almost exactly like the Wii's remote control and its sensor bar..

when it finds the proper two IR beacons(or 3,4 whatever) it simply sets up a course to them and scootches on in.  Now one of the problems with IR is that its suspectible to background noise..  candles, sun, some flash lights, that kinda stuff can ruin IR..  or at least give you false positives.  False positives are easy enough to counter with light patterns.  Set the IR led's to flash in certain patterns. Like 1, 4, 2, 3, 1, 4, 2, 3, etc etc(assuming 4 led's are used) and set the robot up to recongnize this.
Title: Re: better proximity sensor
Post by: airman00 on November 30, 2007, 12:27:42 PM
http://www.schursastrophotography.com/robotics/beac1.html (http://www.schursastrophotography.com/robotics/beac1.html)



and you should make something like this
(http://www.pololu.com/products/pololu/0701/medium.jpg)


What is your budget?
Title: Re: better proximity sensor
Post by: s80ts0465 on November 30, 2007, 12:50:36 PM
The price isn't a problem.

I've already read the article of Pammi and i think i'll realize it. It seems a easy, cheap and working system.
So i'd use 2 PNA4602 and 1 IR led.
Do you maybe know which are the negative side of this system?and how to solve them?

Ste
Title: Re: better proximity sensor
Post by: airman00 on November 30, 2007, 01:21:57 PM
Well the problems that I see is sunlight will mess up the IR  and that there has to be an open path between the base and the robot - other wise the IR light gets blocked.
Title: Re: better proximity sensor
Post by: Ro-Bot-X on November 30, 2007, 01:30:57 PM
Well the problems that I see is sunlight will mess up the IR
Sunlight comes in from windows. Just install the station in the opposite corner of the room.

Quote
  and that there has to be an open path between the base and the robot - other wise the IR light gets blocked.
True, but the robot should have wheel encoders and at least try to track it's wereabouts. There should also be a "find the charger routine" that would move the robot towards large open spaces and search for the beacon.
Title: Re: better proximity sensor
Post by: s80ts0465 on December 01, 2007, 01:10:09 AM
that's not a problem for me, my robot will be used in an no window tunnel ::)