| 摘要 |
A carwash includes an emergency stop triggered by a car horn. A controller with a microphone listens to various sounds generated during the carwash process and performs a simple spectrum analyses to identify sounds characteristic of car horns. Rather than knowing beforehand a plethora of different car horns, the controller recognizes any number of unknown car horns because virtually all car horn tones are each comprised of multiple prominent frequencies, as opposed to a single frequency note such as the electronic “beeeeep” of a microwave oven. Steady, multiple prominent frequency tones of car horns are readily distinguishable from the noise of carwash spray, which might explain why humans can readily distinguish a car horn from carwash noises, regardless of whether the horn is louder or quieter than the surrounding carwash sounds. In some examples, the horn-activated emergency stop automatically sends a text/video message to a remote carwash owner or manager. |
