CN102879480B - Method for delaying self-adaptive ultrasonic phased array wedge - Google Patents

Abstract

The invention discloses a method for delaying time of an adaptive ultrasonic phased array wedge. The invention uses an ultrasonic phased array detection device to carry out non-destructive detection on workpieces, and obtains the wedge delay time after the relevant parameters of the equipment are set. and probe start wave end time , and remove the signal whose amplitude is lower than the lower limit threshold in the detection process, and use the moving average algorithm to smooth the obtained [ , ] within the range of the echo signal, and detect the peak value of the echo signal and the time of the peak value during this period, and redefine the time as , to achieve the purpose of adaptive ultrasonic phased array wedge delay. The invention combines the phase-controlled ultrasonic imaging technology to remove the echo signal generated by the system error in the actual detection image of the ultrasonic phase-controlled array, which is beneficial to the detection personnel to distinguish the defect signal and improves the detection rate.

Description

A Method of Adaptive Ultrasonic Phased Array Wedge Delay

technical field

The invention relates to the field of ultrasonic phased array non-destructive testing, in particular to an adaptive ultrasonic phased array wedge delay method.

Background technique

Ultrasonic phased array nondestructive testing technology plays an important role in modern industrial nondestructive testing and has great application prospects. In ultrasonic phased array non-destructive testing, it is often necessary to install a wedge under the probe to achieve the purpose of using the ultrasonic far-field region for detection and initially deflecting the ultrasonic beam at a certain angle. Since it also takes a certain amount of time for the ultrasonic wave to propagate in the wedge, it is necessary to measure this time at the beginning of the detection, that is, to calibrate the wedge delay of the ultrasonic phased array detection device. However, because the wedges will continue to wear during use, especially in many online detection applications, once the wedges wear a lot, and the wedges cannot be recalibrated in time, it will cause the There is an error in the positioning of the internal defects of the inspected workpiece.

In order to solve the above problems and improve the positioning accuracy of ultrasonic phased array nondestructive testing, the present invention proposes a method for adaptive ultrasonic phased array wedge delay, which only needs to be performed once when the ultrasonic phased array detector starts to work. Wedge delay calibration can automatically calculate the wedge delay in subsequent use, so as to achieve the purpose of adaptive ultrasonic phased array wedge delay.

Contents of the invention

The purpose of the present invention is to improve the deficiencies of the prior art and provide a method for adaptive ultrasonic phased array wedge time delay.

The steps of a method for adaptive ultrasonic phased array wedge time delay are as follows:

Step 1: Install the probe and wedge on the host of the ultrasonic phased array detection device, and perform sound velocity calibration, wedge delay calibration, sensitivity calibration and encoder calibration on the ultrasonic phased array detection device;

Step 2: Set the delay rule, focus rule, gain, suppression, start, range, sound velocity, voltage, average, scale, workpiece thickness, workpiece material, detection mode, focus depth, probe type, etc. of the ultrasonic phased array detection device. Number of probe array elements, probe frequency and beam type;

Step 3: Obtain the wedge delay time according to the wedge delay calibration procedure in step 1 and probe start wave end time ;

Step 4: Remove some signals whose amplitude is lower than the lower threshold, using the following formula:

, k∈[1,N]

in , for the time range [ , The echo signal obtained in ], is the reference amplitude of the logarithmic coordinate system, is the lower threshold, is the processed echo signal, N is the number of values contained in x, and k is the index;

Step 5: Use the moving average algorithm to smooth the echo signal processed in step 4. The expression of the moving average algorithm is as follows:

, k∈[1,N-n+1]

where x is the time range [ , ], y is the smoothed echo signal, N is the number of values contained in x, n is the number of values used for each average in the moving average algorithm, and k is the index;

Step 6: Detect signal y in the time range [ , ] and the time of the maximum value, and consider this time as the new ultrasonic phased array wedge delay time, and redefine this time as ;

Step 7: In the process of ultrasonic phased array non-destructive testing, repeat steps 4 to 6 to continuously obtain new ultrasonic phased array wedge delay time , to achieve the purpose of adaptive ultrasonic phased array wedge delay.

Beneficial effects of the present invention: the present invention combines the ultrasonic phased array non-destructive testing technology to extract the wedge delay signal contained in the echo signal, and only needs to perform wedge delay calibration once when the ultrasonic phased array detector starts to work. It can continuously adapt to the delay caused by wedge wear in subsequent use, thereby improving the positioning accuracy of the internal defects of the inspected workpiece.

Description of drawings

FIG. 1 is a schematic diagram of a peak detection method of an adaptive ultrasonic phased array wedge delay method according to the present invention.

Detailed ways

Embodiments of the present invention are provided below in conjunction with accompanying drawings, describe technical scheme of the present invention in detail:

Step 1: Install the probe and wedge on the host of the ultrasonic phased array detection device, and perform sound velocity calibration, wedge delay calibration, sensitivity calibration and encoder calibration on the ultrasonic phased array detection device. In this example, the ultrasonic phased array detection The host model of the device is OMNISCAN MX, the probe model is 5L64-A2, and the wedge model is SA2-N55S;

Step 2: Set the delay rule, focus rule, gain, suppression, start, range, sound velocity, voltage, average, scale, workpiece thickness, workpiece material, detection mode, focus depth, probe type, etc. of the ultrasonic phased array detection device. The number of probe array elements, probe frequency and beam type, in this example, sector scan, gain -16dB, suppression 0%, initial 0mm, range 150mm, sound velocity 3230m/s, voltage 80V, average 1 time, workpiece thickness 110mm, workpiece The material is carbon steel, the focus depth is 200mm, the probe type is longitudinal wave probe, the number of probe array elements is 64, the probe frequency is 5MHz, and 55°shear wave detection;

Step 3: Obtain the wedge delay time according to the wedge delay calibration procedure in step 1 and probe start wave end time , in this case , ;

Step 4: Remove some signals whose amplitude is lower than the lower threshold, using the following formula:

, k∈[1,N]

in , for the time range [ , The echo signal obtained in ], is the reference amplitude of the logarithmic coordinate system, is the lower threshold, is the processed echo signal, N is the number of values contained in x, and k is the index;

Step 5: Use the moving average algorithm to smooth the echo signal processed in step 4. The expression of the moving average algorithm is as follows:

, k∈[1,N-n+1]

where x is the time range [ , ], y is the smoothed echo signal, N is the number of values contained in x, n is the number of values used for each average in the moving average algorithm, and k is the index;

Step 6: As shown in Figure 1, after the wedge is worn to a certain extent in this example, the detection signal y is within the time range [ , ] in the maximum value and the time of the maximum value, it is detected that the time is about , and consider this time as the delay time of the new ultrasonic phased array wedge, and redefine this time as ,Right now ;

Step 7: In the process of ultrasonic phased array non-destructive testing, repeat steps 4 to 6 to continuously obtain new ultrasonic phased array wedge delay time , to achieve the purpose of adaptive ultrasonic phased array wedge delay.

Claims (1)

1. A method for adaptive ultrasonic phased array wedge time delay, characterized in that the method may further comprise the steps: Step 1: Install the probe and wedge on the host of the ultrasonic phased array detection device, and perform sound velocity calibration, wedge delay calibration, sensitivity calibration and encoder calibration on the ultrasonic phased array detection device; Step 2: Set the delay rule, focus rule, gain, suppression, start, range, sound velocity, voltage, average, scale, workpiece thickness, workpiece material, detection mode, focus depth, probe type, etc. of the ultrasonic phased array detection device. Number of probe array elements, probe frequency and beam type; Step 3: According to the wedge delay calibration procedure in step 1, obtain the time t _d of wedge delay and the end time t _s of the beginning wave of the probe; Step 4: Remove some signals whose amplitude is lower than the lower threshold, using the following formula: $\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\left\{\begin{array}{cc}{\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>& {\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&Greater\; Equal;</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}\\ \mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; ,</span>& {\mathrm{<span\; class="notranslate">\; x</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; i</span>}}_{\mathrm{<span\; class="notranslate">\; min</span>}}\end{array}\right.<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; \&Element;</span><span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; ]</span>$ Where x′(k)=20lg(f(k)/f _ref ), f(k) is the echo signal acquired within the time range [t _s ,t _d ], f _ref is the reference amplitude of the logarithmic coordinate system , i _min is the lower limit threshold, x(k) is the processed echo signal, N is the number of values contained in x, and k is the index; Step 5: Use the moving average algorithm to smooth the echo signal processed in step 4. The expression of the moving average algorithm is as follows: $\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ]</span><span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; \&Element;</span><span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ]</span>$ Among them, x is the echo signal obtained in the time range [t _s , t _d ], y is the echo signal after smoothing, N is the number of values contained in x, and n is the average value of each time in the moving average algorithm The number of values used, k is the index; Step 6: Detect the maximum value and the time of the maximum value of the signal y in the time range [t _s , t _d ], and consider this time as the new ultrasonic phased array wedge delay time, and redefine this time is t _d ; Step 7: During the ultrasonic phased array nondestructive testing process, repeat steps 4 to 6 to continuously obtain new ultrasonic phased array wedge delay time t _d , so as to achieve the purpose of adaptive ultrasonic phased array wedge delay time.