| 摘要 |
An acoustic positioning system comprising: a) a receiver comprising at least two microphones, that generates a signal in response to ultrasound waves that it receives, at least one microphone being mounted on the receiver so that an outer surface of the microphone is substantially flush, with a surface of the receiver adjacent to and surrounding the microphone, wherein substantially flush is within half a wavelength of the lowest frequency used; b) an implement that moves relative to the receiver on a positioning surface on top of which the receiver rests, and comprises at least one ultrasound transmitter that transmits ultrasound waves to the receiver; and c) a controller that uses the signal to track a position of the implement on the positioning surface. |
