Ultrasonic ranging system and method thereof in air by using parametric array
US7196970B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 2004 |
| Grant date | Mar 27, 2007 |
| Priority date | — |
| Expiry date | Apr 3, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S15/102
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An ultrasonic ranging method for measuring a distance to an object in an air includes the steps of generating a first and a second primary ultrasonic waves having a frequency f1 and f2, respectively, transmitting the first and the second primary ultrasonic waves in a same direction, wherein a secondary ultrasonic wave having a frequency corresponding to the difference of two frequencies fd=f1−f2 is created by a nonlinear property of the air and radiated to the object, detecting an echo pulse of the secondary ultrasonic wave reflected from the object, and measuring the distance to the object based on a propagation time of the secondary wave.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.