hole detecting sensor

[yokoma]

hi
we are doing a robotic project for handicap people. the robot must be equipped with a sensor that when it detects a hole ahead, announces about the hole. would you plz help me how to go throuhg it?

[ScorpIon]

I'm no expert but how do you have to detect the hole? Will the robot be on top of the hole?
Read this SENSORS - SHARP IR RANGE FINDER, maybe that can help you out.

Point it downwards or at an angle, then when it senses a difference in distance to the pavement or whatever then it has seen a hole.