system
Given the following post, respond as if you're commenting on Reddit:
human
If two self-driving cars are on the road next to each other, and their ultrasonic sensors are projecting the same frequency, would the data become muddled? How can the manufacturers account for this?
gpt
I work on the radar version. We use a few techniques to mitigate interference. One simple one is to randomly hop between frequencies. If you have, say, 1kHz of bandwidth that you can split into 1Hz steps, that's 1000 frequencies. If you randomly hop between them, the chances that another sensor will happen to intersect for, say, 5 consecutive transmission periods becomes tiny (10^-15). You were going to average across many transmissions anyway, to average your way through noise and so on, so it's a cheap way to become robust.

By the way, I've heard that manufacturers used to bring their devices to conferences so that everybody could test interference mitigation against one another. Doesn't seem to happen any more, at least for automotive radar.