METHOD AND SYSTEM FOR TRANSDUCER ELEMENT FAULT DETECTION FOR PHASED ARRAY ULTRASONIC INSTRUMENTS

• US 20100242613A1
• Filed: 03/25/2009
• Published: 09/30/2010
• Est. Priority Date: 03/25/2009
• Status: Active Grant

• Current Assignee: Olympus Ndt
• Original Assignee: Olympus Ndt
• Inventors: SIMARD, Christian, DRUMMY, Michael
• Granted Patent: US 8,577,629 B2
• Time in Patent Office: Days
• US Class Current: 73/641
• CPC Class Codes: G01N 29/262 by electronic orientation or focusing, e.g. with phased arrays phased arrays per se G10K11/34
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects
• CPC Class Codes: G01S 15/8918 the array being linear
• CPC Class Codes: G01S 15/8925 the array being a two-dimensional transducer configuration, i.e. matrix or orthogonal linear arrays
• CPC Class Codes: G01S 7/5205 Means for monitoring or calibrating

Abstract

The invention disclosed herein provides a method and system related to phased array ultrasonic systems to identify faults in individual element on a regular basis. The method and system of the present disclosure are based on a simple approach of calculating energy levels in response signals from each individual element and then identifying any discontinuities or unexpected drops in energy levels sensed during a typical phased array operation.

Claims

1. A method of detecting transducer element faults in ultrasonic phased array instruments having a plurality of transducer elements, comprising:

applying ultrasonic pulses to the transducer elements of the phased array system;

calculating an energy level for the transducer elements individually according to a response signal reading obtained from the transducer elements individually during a predetermined time period;

noting a dropped energy level in one or more transducer elements owing to an element fault; and

identifying any of the elements as a faulty element based on the energy level thereof.

2. The method of claim 1, including identifying the faulty element by comparing the energy level thereof to the energy levels sensed by other transducer elements.

3. The method of claim 1, further comprising applying the ultrasonic pulses as part of a normal operation of the phased array instruments.

4. The method of claim 1, further comprising obtaining the response signals as part of a normal operation of the phased array instruments.

5. The method of claim 1, further comprising identifying the dropped energy level by obtaining first order derivatives of the energy levels and obtaining a valley in the slope of the energy levels.

6. The method of claim 1, further comprising identifying the dropped energy level by obtaining second order derivatives of the energy levels and evaluating if any of the second order derivatives meets or exceeds a predetermined threshold value.

7. The method of claim 1, further comprising identifying an element fault by

obtaining first order derivatives of the energy levels, further obtaining valleys in the slope of the energy levels with respect to elements and further determining a first element index number associated with a given valley;

obtaining second order derivatives of the energy levels and evaluating if any of the second order derivatives meets or exceeds a predetermined threshold value and further determining a second element index number associated with the second order derivatives of the energy levels that meets or exceeds the predetermined threshold value; and

,

if the first element index number equals the second element index number minus numeral 1, further determining the element associated with the first element index number is faulty.

8. The method of claim 1, further comprising recognizing and selecting the time period during which the drop in the energy level appears.

9. The method of claim 1, further comprising repetitively sampling the energy levels to include the time periods during which the drop in the energy level occurs.

10. The method of claim 1, further comprising identifying the drop in the energy level by identifying large differences between the energy E(i) and an expected energy E_e at an element i, wherein a line drawn between the energy of immediate neighboring elements, E(i−

1) and E(i+1), and the expected energy E_e is provided by the value when line E(i−

1) and E(i+1) intersects with element i.

11. The method of claim 1, further comprising identifying the drop in energy level by obtaining a maximum value of the energy in each transducer element during a plurality of the predetermined time periods of a complete course of an ultrasonic phased array operation;

and

further identifying a drop in the maximum value of the energy in at least one of the transducer elements in comparison with the maximum values of energy levels of other transducer elements.

12. The method of claim 1, further comprising identifying the drop in energy level in a manner avoiding an element blind spot.

13. A method of detecting transducer element faults in ultrasonic phased array instruments having a plurality of transducer elements, comprising:

applying ultrasonic pulses to the transducer elements of the phased array system with a phase shift with respect to the elements;

calculating an energy level for the transducer elements individually according to a response signal reading obtained from the transducer elements individually during a predetermined time period, with the phase shift removed with respect to the elements;

noting a dropped energy level in one or more transducer elements owing to an element fault; and

identifying any of the elements as a faulty element based on the energy level thereof.

14. A system for detecting transducer element faults for ultrasonic phased array instruments, comprising:

a phased array transducer having a plurality of transducer elements operable to be pulsed by ultrasonic signals and to receive response signals;

an energy calculator operable to calculate an energy level of the response signals received from the transducer elements individually during a predetermined time period; and

a fault analyzer operable to identify a drop in the energy level received on the transducer elements to identify a faulty element.

15. The system of claim 14, wherein the fault analyzer is operable to compare the energy levels with the energy levels received on remaining transducer elements, relative to the faulty transducer element.

16. The system of claim 14, wherein the phased array transducer is configured to be pulsed by ultrasonic signals and to receive response signals, as part of a normal operation of the ultrasonic phased array instrument.

17. The system of claim 14, wherein the fault analyzer is configured to detect the drop in the energy by obtaining first order derivatives of the energy levels and identifying a valley in the slope of the energy levels in a given element.

18. The system of claim 14, wherein the fault analyzer is configured to detect the drop in the energy level by obtaining second order derivatives of the energy levels and evaluating if the absolute value of any of the second order derivatives exceeds a predetermined threshold value.

19. The system of claim 14, wherein the fault analyzer is configured to detect the drop in the energy level by obtaining first order derivatives of the energy levels, further obtaining valleys in the slope of the energy levels with respect to elements and further determining a first element index number associated with a given valley;

obtaining second order derivatives of the energy levels and evaluating if any of the second order derivatives meets or exceeds a predetermined threshold value and further determining a second element index number associated with the second order derivatives of the energy levels that meets or exceeds the predetermined threshold value; and

,

if the first element index number equals the second element index number minus numeral 1, further determining the element associated with the first element index number is faulty.

20. The system of claim 14, wherein the fault analyzer is configured to identify a drop in energy level by obtaining a maximum value of the energy level in each transducer element of a plurality of the predetermined time periods while performing normal ultrasonic phased array tests;

and

to further identify a drop in the maximum value of the energy levels in at least one transducer element in comparison with the maximum value of the energy levels of other transducer elements.