Object detection

[robotcy]

If i use 3 ultrasonic sensors (e.g. a maxsonar EZ-51 or a ping))) on perpendicular of each other to detect object and determine its heights would i face any problems? Wave interference maybe? 


two kinds of objects cans and tetrapacks. Heights 3.5 cm and 8cm. If the lowest sensor gets a smaller reading than the two above then its a can if the two lower sensors have the same reading and the one above has a greater reading then its a tetrapack if the 3 sensors have the same reading the its  wall

[Soeren]

Hi,

If i use 3 ultrasonic sensors (e.g. a maxsonar EZ-51 or a ping))) on perpendicular of each other to detect object and determine its heights would i face any problems? Wave interference maybe? 

You could allways synchronize their clocks. Or, you could use one transmitter and 3 receivers.

two kinds of objects cans and tetrapacks. Heights 3.5 cm and 8cm. If the lowest sensor gets a smaller reading than the two above then its a can if the two lower sensors have the same reading and the one above has a greater reading then its a tetrapack if the 3 sensors have the same reading the its  wall

They'll see each others pings if you use 3 non-synch'ed sensors I'm sure. IR is probably better for this, but you could try making some US absorbing baffles to give each a vertical window.

[robotcy]

http://www.maxbotix.com/MaxSonar-EZ1__FAQ.html

a friend of mine suggested the 6f technique what do you think about that? Could it work?

[Soeren]

Hi,

"6f" describes 3 modes of operation, which of them are you referring to?

[robotcy]

mainly the third

[Soeren]

Hi,

That should do, if you follow their description - initialize with a 100ms pulse and make the pings 20µs to 400µs (90µs being the mathematical mean).
They're not synchronized(!) so stay with 90µs pulses.