navigation using ultrasound

[stjimmy]

Hi,
Is it possible to have a robot to follow a ultrasound or ir signal. ? ? My idea is to have 4 ultrasound sensors for 4 rooms and to activate the sensor corresponding to the room to which the robot should move.By including an obstacle avoidance system it would be able to  avoid obstacle right.
I m confused on the navigation part, is it possible to follow a signal  ? 
please tell me i m a newbie.
I

[AWOL]

I've been toying with the idea of a simple scheme that would attempt to minimise the difference in time of arrival of an ultrasonic ping at two or three wide-spaced receivers.
The idea was to drive a steering servo so that a vehicle would then tend to steer towards the source.

[terryking228]

Hi, I just updated the Ultrasonic Distance page on the http://ArduinoInfo.Info WIKI to use Rob Tillaart's NewPing library.

Here: http://arduino-info.wikispaces.com/UltraSonicDistance

Includes sample code etc..