Method for ultrasonic inspection of irregular and variable shapes

Patent metadata

Field	Value
Publication number	US-10247706-B2
Application number	US-201615145071-A
Country	US
Kind code	B2
Filing date	May 3, 2016
Priority date	Jun 26, 2012
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

System and method for enabling ultrasonic inspection of a variable and irregular shape. The system comprises one or more ultrasonic pulser/receivers, one or more ultrasonic transducer arrays, a shoe or jig to hold and position the array(s), data acquisition software to drive the array(s), and data analysis software to select a respective best return signal for each pixel to be displayed. This system starts with information about the general orientation of the array relative to the part and a general predicted part shape. More specific orientation of the transmitted ultrasound beams relative to the part surface is done electronically by phasing the elements in the array(s) to cover the expected (i.e., predicted) surface as well as the full range of part surface variability.

First claim

The inventiom claimed is:

1. A method comprising:
(a) determining an arc that approximates a curved concave profile of a radiused surface of a part;
(b) determining first focal laws for interrogating the radiused surface such that an ultrasonic transducer array, when pulsed with proper phasing in accordance with the first focal laws, will project respective sequences of focused and steered beams that are directed at respective target locations spaced along an arc having the same radius as the arc determined in step (a);
(c) placing an ultrasonic transducer array at a first position whereat a first scan plane of the ultrasonic transducer array intersects the radiused surface;
(d) while the ultrasonic transducer array is stationary at the first position, pulsing the ultrasonic transducer array in accordance with first focal laws determined in step (b) to interrogate a first target location in the first scan plane by transmitting a first sequence of focused and steered ultrasonic beams that are directed toward the first target location at different steering angles;
(e) forming a first sequence of respective return signals representing respective receive beams returned to the ultrasonic transducer array from the first target location following transmission of each focused and steered ultrasonic beam of the first sequence of focused and steered ultrasonic beams;
(f) processing the first sequence of return signals to generate a first multiplicity of parameter values, each value representing a magnitude of a characteristic of a respective return signal of the first sequence of return signals; and
(g) selecting a first parameter value from the first multiplicity of parameter values that satisfies a condition configured to identify a best return signal of the first sequence of return signals.

2. The method as recited in claim 1 , wherein the parameter values are amplitudes and the condition is having a greatest amplitude.

3. The method as recited in claim 1 , further comprising displaying a first pixel having a first pixel value which is a function of at least the first parameter value.

4. The method as recited in claim 3 , further comprising selecting a second parameter value of the first multiplicity of parameter values that satisfies the condition, wherein the first pixel value is a function of the first and second parameter values.

5. The method as recited in claim 3 , further comprising:
while the ultrasonic transducer array is stationary at the first position, pulsing the ultrasonic transducer array in accordance with second focal laws determined in step (b) to interrogate a second target location in the first scan plane by transmitting a second sequence of focused and steered ultrasonic beams that are directed toward the second target location at different steering angles;
forming a second sequence of return signals representing respective receive beams returned to the ultrasonic transducer array from the second target location following transmission of each focused and steered ultrasonic beam of the second sequence of focused and steered ultrasonic beams;
processing the second sequence of return signals to generate a second multiplicity of parameter values, each value representing a magnitude of a characteristic of a respective return signal of the second sequence of return signals;
selecting a second parameter value from the second multiplicity of parameter values that satisfies a condition configured to identify a best return signal of the second sequence of return signals; and
displaying a second pixel having a second pixel value which is a function of at least the second parameter value, wherein the first and second pixels are displayed in one column on a display screen.

6. The method as recited in claim 1 , further comprising:
moving the ultrasonic transducer array from the first position to a second position whereat a second scan plane of the ultrasonic transducer array intersects the radiused surface;
while the ultrasonic transducer array is stationary at the second position, pulsing the ultrasonic transducer array in accordance with the first focal laws to interrogate a second target location in the second scan plane by transmitting a second sequence of focused and steered ultrasonic beams that are directed toward the second target location at different steering angles;
forming a second sequence of return signals representing respective receive beams returned to the ultrasonic transducer array from the second target location following transmission of each focused and steered ultrasonic beam of the second sequence of focused and steered ultrasonic beams;
processing the second sequence of return signals to generate a second multiplicity of parameter values, each value representing a magnitude of a characteristic of a respective return signal of the second sequence of return signals;
selecting a second parameter value from the second multiplicity of parameter values that satisfies a condition configured to identify a best return signal of the second sequence of return signals; and
displaying a second pixel having a second pixel value which is a function of at least the second parameter value, wherein the first and second pixels are displayed in one row on a display screen.

7. A method comprising:
(a) determining a radius of an inspection arc suitable for inspecting a radiused surface of a part having a curved concave profile;
(b) determining a position of an ultrasonic transducer array relative to the radiused surface such that, when properly phased, the ultrasonic transducer array is capable of projecting focused beams at a plurality of target locations spaced along the inspection arc;
(c) determining focal laws for interrogating each of the plurality of target locations spaced along the inspection arc using a respective sequence of focused beams having different steering angles for each target location;
(d) positioning the ultrasonic transducer array in the position determined in step (b);
(e) pulsing the ultrasonic transducer array in accordance with the focal laws determined in step (c);
(f) forming respective return signals representing respective receive beams returned to the ultrasonic transducer array from the part following pulsing in step (e); and
(g) selecting a respective parameter value of a respective best return signal for each interrogated target location.

8. The method as recited in claim 7 , further comprising:
displaying respective pixels having respective pixel values, each pixel value being a function of at least a respective selected parameter value.

9. The method as recited in claim 8 , wherein the target locations lie in a scan plane and the respective pixels are displayed in a column on a display screen.

10. The method as recited in claim 8 , wherein step (c) comprises determining focal laws for interrogating target locations which are spaced at equal distances along an inspection arc having a radius approximating a radius of the radiused surface.

11. The method as recited in claim 7 , further comprising supplying fluid acoustic couplant into a space between the ultrasonic transducer array and the part, wherein step (f) comprises applying respective gains to the respective return signals, the gains being selected to compensate for different amounts of attenuation caused by fluid acoustic couplant in the space between the ultrasonic transducer array and the part, the respective gains being a function of distance of travel of each echo through the fluid acoustic couplant.

12. A method for inspecting a radiused surface having a curved concave profile, the method comprising:
positioning an array of transducer elements at a first

Assignees

• Boeing Co

Inventors

• Hutchinson Michael C
• Kennedy James C
• Fetzer Barry A
• Duncan Michael Joseph
• Grewal Navpreet S
• Walton Steven Ray
• Bui Hien T

Classifications

• G01N2291/2638

  Complex surfaces · CPC title

• G01N29/262 Primary

  by electronic orientation or focusing, e.g. with phased arrays (phased arrays per se G10K11/34) · CPC title

• G01N29/11

  by measuring attenuation of acoustic waves · CPC title

• G01N29/043 Primary

  in the interior, e.g. by shear waves · CPC title

• G01N2291/0231

  Composite or layered materials · CPC title