Let's Make Robots!

ultrasound interference

Another question. Am planning to use 3 ultrasound one directly above the other at about 3 cm distance from each other my question is there a possibilitty that their signals interfere with each other thus messing out the results?

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.
Use one at a time and wait some time before "firing" the next ultrasound sensor to let the echoes from the previous one die out.

I'm not sure what type of ultrasonic sensor you are planning on, but the Maxbotix sensors have the capability to be daisychained to sequence the triggering for this very reason. I recommend you read section 6 here:  http://www.maxbotix.com/MaxSonar-EZ1__FAQ.html

I am using the 6f technique on my Charlie bot.

You can use as many infrared sensors as you want. I have used up to 4 Sharp GP2D12 sensors on a single robot without any problems. Even connected 2 of these sensors to one ADC channel before just to combine them for wider detection because I was lazy. Not recommended by those "experts" but never did any damage to my hardware and worked just fine............
will the same happen if i use infared sensors?
Sure Will. The Interference is called "Ping Pong Ping".  A "Ping" in one sensor causes a "Pong" in the next sensor and culminates once more as a "Ping" in the final sensor. Hence, the term "Ping Pong Ping". Echoes could return out of phase and cancel each other out whereby no object is detected at all. When this happens you will feel worse than a "Ding Dong". Why you would feel like a "Ding Dong Ding". The next step below a "Ding Dong".

This wouldn't occur if you did the pings at different times though as the initial ping is started by the pulseout and not a continuous ping. This of course would be for sensors that have a trigger/response method of getting distance and wouldn't work with ultrasonic sensors that give continuous analoge readings.

If you do a ping simulataneously, then yeah, you could run into issues as zeitron mentioned.

With IR sensors, you'd run into an issue more as they usually have continuous ir emmisions.