'virtual wall'

[electricano]

helloo. i wan to build a robot that will only move in confined area. i have done some researches. i found that the 'virtual wall use in automatic lawn mower 'ROBOMOW' and the autonomous vacuum cleaner 'Roomba' meet my specifications.

can anyone tell me how to build the similar thing? or any other methods apart of these?

 

[bmcculla]

I'd try an infrared LED shining through a slit. The light comming through the slit forms your "wall". The "wall" light can be detected by a number of phototransistors around your robot. This should work with Visible LED's as well- which might make aligning your LED and Slit easier.

Brent

 

[electricano]

does anyone have the better IR transmitter and receiver circuit? i have tried some of the circuit on the internet but the detection range is very short.

and

anyone know about the virtual wall used for the ROBOMOW?

they just put wire around the lawn and turn on the switch.how does it actually work and what is the concept behind it?

if i want to build the similar system,how does it look like?what type of sensors that i need?

anyone knows?plz tell me

 

[bmcculla]

They probably run a certain frequency signal through the wire. The wire works like an antenna braodcasting the signal over short distances. A simple inductor can be used to detect the signal- more amplitude = closer to the wire.

 

[electricano]

anyone has the 'hacked' version of the 'virtual wall' system? as well as its detector?