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EP-4042181-B1 - ULTRASONIC DETECTOR

EP4042181B1EP 4042181 B1EP4042181 B1EP 4042181B1EP-4042181-B1

Inventors

  • SEWELL, Colin
  • HURST, SCOTT

Dates

Publication Date
20260506
Application Date
20201001

Claims (15)

  1. An ultrasonic detector (100) comprising: a body comprising: a first surface (126) for coupling to a mobile device (110); a second planar surface (124) directed away from the mobile device; a plurality of equidistant openings provided on the second planar surface, each of the plurality of equidistant openings associated with one of a plurality of ultrasonic arrays (120); each of the plurality of ultrasonic arrays having a plurality of sensors (122), the arrays being arranged with radial symmetry, adjacent sensors being separated by a distance d, wherein d is smaller than or equal to half the minimum wavelength of the signal to be detected; a processor (252) for receiving ultrasonic acoustic signals from each of the plurality of ultrasonic arrays and pre-processing the received ultrasonic acoustic signals from each of the plurality of ultrasonic arrays to determine a direction vector from the times of arrival (TOA) and time differences of arrival (TDOA) for each of the received ultrasonic signals from each of the plurality of ultrasonic arrays; and an interface (256) for providing pre-processed signals from the ultrasonic detector to the mobile device for further processing on the mobile device to triangulate the direction vector and distance to an ultrasonic acoustic source from the individual direction vectors determined by the plurality of ultrasonic arrays.
  2. The ultrasonic detector of claim 1 wherein each array comprises a plurality of ultrasonic transducers.
  3. The ultrasonic detector of claim 2 wherein the plurality of ultrasonic transducers are arranged in a uniform circular array.
  4. The ultrasonic detector of claim 3 wherein there is at least provided two arrays for the plurality of arrays and three transducers for the plurality of ultrasonic transducers.
  5. The ultrasonic detector of any one of claims 1 to 4 wherein for each of the plurality of arrays the processor determines an azimuth and elevation of a source.
  6. The ultrasonic detector of any one of claims 1 to 5 wherein the processor performs frequency analysis, noise filtering, sound pressure level and mass flow determination on the received ultrasonic acoustic signal.
  7. The ultrasonic detector of any one of claims 1 to 6 wherein the source is associated with a corona discharge.
  8. A method of ultrasonic acoustic source location, the method comprising: receiving a plurality of ultrasonic acoustic signals at a plurality of openings in an ultrasonic detector (100), each opening having one of a plurality of ultrasonic arrays (120), each of the plurality of ultrasonic arrays having a plurality of sensors (122), the ultrasonic arrays being arranged with radial symmetry, adjacent sensors being separated by a distance d, wherein d is smaller than or equal to half the minimum wavelength of the signal being detected; pre-processing the plurality of ultrasonic acoustic signals by one or more processors (252) of the ultrasonic detector received plurality of ultrasonic acoustic signals from each of the plurality of ultrasonic arrays to determine a plurality of direction vectors from the times of arrival (TOA) and time differences of arrival (TDOA) for each of the received ultrasonic signals from each of the plurality of ultrasonic arrays; and transmitting the pre-processed acoustic signals to a mobile device (110); wherein a first surface (126) of the ultrasonic detector couples to the mobile device and a second planar surface (124) is directed away from the mobile device and has the plurality of openings; and wherein the plurality of direction vectors from the plurality of ultrasonic arrays are triangulated to determine a composite direction vector and the distance and sensor data of the mobile device associated with the determined location and a location of the source is identified on a display of the mobile device.
  9. The method of claim 8 wherein each of the plurality of arrays comprises plurality of ultrasonic transducers and each uniform circular array comprises at least three ultrasonic transducers.
  10. The method of claim 9 wherein the plurality of arrays and the plurality of ultrasonic transducers are arranged in a uniform circular array.
  11. The method of any one of claims 8 to 10 wherein the plurality of arrays of the ultrasonic detector comprises at least three arrays.
  12. The method of any one of claims 8 to 11 wherein a Linear Intersection (LI) method calculates a number of potential source locations from points of closest intersection for all pairs of bearing lines and uses a weighted average of these locations for a final location estimate.
  13. The method of any one of claims 8 to 12 wherein for each of the plurality of arrays, vectors are determined defining an azimuth and an elevation to the source.
  14. The method of any one of claims 8 to 13 further comprising determining a Sound Pressure Level (SPL) and mass-flow rate associated with the source.
  15. A non-transitory computer readable memory containing instructions to cause the ultrasonic detector (100) of any of claims 1 to 7 to execute the steps of the method of any of claims 8 to 14.

Description

CROSS-REFERNCE TO RELATED APPLICATIONS The present application claims priority to United States Provisional Application No. 62/908,907 filed October 1, 2019. TECHNICAL FIELD The present disclosure relates to ultrasonic detectors and in particular to an ultrasonic leak detector such as ultrasonic gas leak detectors (UGLD) for detecting gas leaks and ultrasonic sound detectors (USD) for detecting corona discharge on extra-high voltage (EHV) transmission system insulators. BACKGROUND When a leak occurs in a system such as a pipeline the escaping gas emits high-frequency sounds which cannot be easily identified by human hearing. Pipeline leak detection system have been used to determine if a leak has occurred in systems which contain liquids and gases. Ultrasonic detectors have been utilized to aid in the identification of leaks in the delivery of liquids and gases but have been cumbersome and expensive limiting their usage and application. In the example of a pipeline, using an UGLD will maintain the integrity of the pipeline to ensure safe and effective delivery. Additional methods of detection that may be utilized include hydrostatic testing, infrared, and laser technology after pipeline erection and leak detection during service. Similarly motors may generate a corona discharge which can be detected as sound to identify a malfunction. An acoustic camera or detection device is used to locate sound sources such as leaks that emit high frequency noise and to characterize them such as for example gas system or electrical discharges in real-time. The acoustic camera typically consists of a group of microphones, also called a microphone array, from which signals are simultaneously collected and processed to form a representation of the location of the sound sources. An example of a real-time ultrasound imaging device is the DISTRAN™ Ultra M real-time "acoustic camera" leak detector. DISTRAN uses phased array sensors along with frequency filtering to discriminate between sources of sound that do not represent leaks and those that do. The large array utilizes a pseudo-random distribution of sensor pairs to facilitate source discrimination and are limited to identifying a location from the detector. The ability to easily and effectively locate a leak or noise source increases the reliability and safety of industrial systems however, the usage of existing systems has been limited by the cost, size and complexity and lack of features. Accordingly, systems and methods that enable improved ultrasonic detectors remains highly desirable. US 2017/0089800 A1 describes, according to its abstract, an ultrasonic gas leak detector system for locating a source of ultrasonic airborne energy. An example includes a plurality of spatially separated ultrasonic gas leak detectors, each configured to generate signals indicative of detected angles of arrival of received ultrasonic energy at the respective detectors. A locator processor receives the signals generated by the detectors, and is configured to process the signals to determine a location in three dimensions of the source of the ultrasonic energy received at the detectors and provide locator processor output signals indicative of the location. US 2018/333135 A1 describes, according to its abstract, a portable facility failure diagnosis device using detection of radiation ultrasonic waves, comprising: an ultrasonic sensor array; a data acquisition board (DAQ board) in which an electronic circuit for acquiring ultrasonic signals at a sampling frequency of the ultrasonic signals sensed by the ultrasonic sensor array is mounted on a substrate of the data acquisition board (DAQ board); a main board in which an operation processing device that processes the ultrasonic signals received from the DAQ board is mounted on the substrate and the processed ultrasonic sound source information to a display device; a data storage medium storing data processed in the operation processing device of the main board; a display device visually displaying the data processed; and an optical camera picking up an image of a direction. US 2019/139552 A1 describes, according to its abstract, an electronic device including a display, wherein the display is configured to present a user interface, wherein the user interface comprises a coordinate system. The coordinate system corresponds to physical coordinates. The display is configured to present a sector selection feature that allows selection of at least one sector of the coordinate system. The at least one sector corresponds to captured audio from multiple microphones. The sector selection may also include an audio signal indicator. The electronic device includes operation circuitry coupled to the display. The operation circuitry is configured to perform an audio operation on the captured audio corresponding to the audio signal indicator based on the sector selection. WO 02/066950 A1 describes, according to its abstract, a portable leak detector for sear