Ultrasonic sensor and method of using such a sensor

• US 5,703,834 A
• Filed: 03/25/1996
• Issued: 12/30/1997
• Est. Priority Date: 03/23/1995
• Status: Expired due to Fees

• Current Assignee: Imra Europe S.A.S. (Aisin Corp.)
• Original Assignee: Imra Europe S.A.S. (Aisin Corp.)
• Inventors: Bonnefoy, Pierre
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US08/621,435
• Time in Patent Office: 645 Days
• Field of Search: 367/140, 367/153, 367/138, 367/99
• US Class Current: 367/99
• CPC Class Codes: B06B 1/0622 on one surface

Abstract

A ultrasonic sensor for detecting the location of objects disposed in a substantially gaseous environment includes a plurality of nodes arranged into a uniform network. A plurality of circular transducers are provided such that each transducer is disposed at a node. The center of adjacent transducers are spaced at a distance no greater than the wavelength of acoustic waves emitted by the transducers. A method of detecting the location of objects disposed in a substantially gaseous environment is also disclosed.

Claims

1. An ultrasonic sensor for detecting the location of objects disposed in a substantially gaseous environment, comprising:

a plurality of nodes arranged into a uniform network; and

a plurality of circular transducers that operate at a specified set of frequencies, each transducer having a diameter of approximately a wavelength of acoustic waves emitted by the transducers and having a center and disposed at a node such that the center of adjacent transducers are spaced at a distance no greater than the wavelength of acoustic waves emitted by the transducers, wherein the transducers are arranged into several rows, the transducers of each row sharing a common axis, such that the axes intersect at a center of a common central transducer.

2. An ultrasonic sensor according to claim 1, wherein the network is plane.

3. An ultrasonic sensor according to claim 1 wherein the network is a triangular mesh network.

4. A method of detecting the location of objects disposed in a substantially gaseous environment, comprising the steps of:

specifying a shape of at least one object disposed in the substantially gaseous environment;

emitting an ultrasonic wave from a sensor including a plurality of circular transducers the diameter of which is approximately the wavelength of acoustic waves emitted by the transducers, each transducer disposed at one of a plurality of nodes arranged into a uniform network such that the center of adjacent transducers are spaced at a distance no greater than the wavelength of the ultrasonic waves emitted, the wave propagating within the substantially gaseous environment;

receiving an echo from the wave; and

analyzing the echo to determine the position of the object within the substantially gaseous environment.

6. A method according to the steps of claim 6, further comprising the step of arranging the transducers into rows such that the receiving step includes receiving the echo from the wave with transducers disposed at ends of the rows.

5. A method according to the steps of claim 6, wherein the receiving step includes using the transducers to receive the echo from the wave.

7. A method according to the steps of claim 6, wherein the shape of the at least one object is specified prior to emitting the ultrasonic wave by scanning the substantially gaseous environment.

8. A method according to the steps of claim 6, wherein the emitting step includes emitting an ultrasonic wave from a specified number of transducers arranged into a row and sharing a common axis that is perpendicular to a shooting plane, such that the emitted wave is propagating within a thin volume enveloping the shooting plane.

9. A method according to the steps of claim 6, wherein the emitting step includes emitting an ultrasonic wave from transducers arranged into a disc such that a central transducer is disposed at a center of the disc.