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

Abstract

The invention discloses a kind of methods of self-adapting ultrasonic phased array voussoir delay. Present invention application ultrasonic phased array detection device carries out non-destructive testing workpiece, after equipment relative parameters setting, obtains the time of voussoir delay With the probe beginning wave end time , and remove in the detection process amplitude be lower than lower limit threshold value signal, using rolling average algorithm smoothly get [ , ] echo-signal in range, and the peak value of echo-signal and the time where peak value in this period are detected, which is newly defined as , achieve the purpose that self-adapting ultrasonic phased array voussoir is delayed. Present invention combination phase-controlled ultrasonic wave imaging technique removes the echo-signal generated due to systematic error in the actually detected image of ultrasonic phased array, be conducive to testing staff to the differentiation of flaw indication, improve recall rate.

Description

The method of a kind of self-adapting ultrasonic phased array voussoir time delay

Technical field

The present invention relates to ultrasonic phased array field of non destructive testing, relate in particular to the method for a kind of self-adapting ultrasonic phased array voussoir time delay.

Background technology

Ultrasonic phased array Dynamic Non-Destruction Measurement plays an important role in modern industry Non-Destructive Testing, has great application prospect.In ultrasonic phased array Non-Destructive Testing, often need to below probe, voussoir be installed, to reach the object that uses ultrasound wave far-field region to detect and make ultrasonic beam generation certain angle initial deflection.Because ultrasound wave is propagated and needed equally the regular hour in voussoir, in the time detecting beginning, need to measure during this period of time the namely voussoir delay calibration to ultrasonic phased array pick-up unit.But because voussoir is in use particularly in a lot of online application that detect, can constantly produce wearing and tearing, once voussoir produces relatively large wearing and tearing, and can not be in time when to voussoir, time delay re-starts calibration, will make the location of tested inside workpiece defect occur error.

In order to address the above problem, improve the positioning precision of ultrasonic phased array Non-Destructive Testing, the present invention proposes the method for a kind of self-adapting ultrasonic phased array voussoir time delay, the method only need to be carried out one time voussoir delay calibration in the time that ultrasonic phased array detector is started working, just can in follow-up use, constantly automatically calculate voussoir time delay, thereby reach the object of self-adapting ultrasonic phased array voussoir time delay.

Summary of the invention

The object of the invention is to improve the deficiencies in the prior art, the method for a kind of self-adapting ultrasonic phased array voussoir time delay is provided.

The method step of a kind of self-adapting ultrasonic phased array voussoir time delay is as follows:

Step 1: probe and voussoir are installed on ultrasonic phased array pick-up unit main frame, ultrasonic phased array pick-up unit is carried out to sound velocity calibration, voussoir delay calibration, sensitivity calibration and encoder calibration;

Step 2: arrange ultrasonic phased array pick-up unit time delay rule, focus on rule, gain, inhibition, initial, scope, the velocity of sound, voltage, average, scale, thickness of workpiece, workpiece material, detecting pattern, the depth of focus, probe type, probe array number, frequency probe and beam type;

Step 3: according to the voussoir delay calibration program in step 1, obtain the time of voussoir time delay with probe ripple end time beginning ;

Step 4: remove the signal of some amplitudes lower than lower limit threshold value, adopt formula as follows:

，k∈[1,N]

Wherein , for time range [ , ] in the echoed signal obtained, for the reference amplitude of logarithmic coordinate system, for lower limit threshold value, for treated echoed signal, N is the number that comprises numerical value in x, and k is index;

Step 5: use moving average algorithm, treated echoed signal in step 4 is carried out to smoothing processing, the expression formula of moving average algorithm is as follows:

，k∈[1,N-n+1]

Wherein, x be time range [ , ] in the echoed signal obtained, y is the echoed signal after smoothing processing, N is the number that comprises numerical value in x, n is each average number that uses numerical value in moving average algorithm, k is index;

Step 6: detection signal y time range [ , ] in maximal value and the time at maximal value place, and think that this time is new ultrasonic phased array voussoir delay time, and by this time redefine into ;

Step 7: in ultrasonic phased array Non-Destructive Testing process, repeating step four, to step 6, constantly obtains new ultrasonic phased array voussoir delay time , reach the object of self-adapting ultrasonic phased array voussoir time delay.

Beneficial effect of the present invention: the present invention is in conjunction with ultrasonic phased array Dynamic Non-Destruction Measurement, extract the voussoir time delayed signal comprising in echoed signal, only need in the time that starting working, ultrasonic phased array detector carry out one time voussoir delay calibration, just can in follow-up use, constantly adapt to due to the voussoir time delay bringing of wearing and tearing, thereby improve the positioning precision to tested inside workpiece defect.

Brief description of the drawings

Fig. 1 is that the peak value of the method for a kind of self-adapting ultrasonic phased array voussoir of the present invention time delay detects schematic diagram.

Embodiment

Provide embodiments of the invention below in conjunction with accompanying drawing, describe technical scheme of the present invention in detail:

Step 1: probe and voussoir are installed on ultrasonic phased array pick-up unit main frame, ultrasonic phased array pick-up unit is carried out to sound velocity calibration, voussoir delay calibration, sensitivity calibration and encoder calibration, in this example, ultrasonic phased array pick-up unit main frame model is OMNISCAN MX, probe model is 5L64-A2, and voussoir model is SA2-N55S; ;

Step 2: the time delay rule that ultrasonic phased array pick-up unit is set, focus on rule, gain, suppress, initial, scope, the velocity of sound, voltage, on average, scale, thickness of workpiece, workpiece material, detecting pattern, the depth of focus, probe type, probe array number, frequency probe and beam type, in this example, adopt sector display, gain-16dB, suppress 0%, initial 0mm, scope 150mm, velocity of sound 3230m/s, voltage 80V, average 1 time, thickness of workpiece 110mm, workpiece material is carbon steel, depth of focus 200mm, probe type is longitudinal wave probe, probe array number 64, frequency probe 5MHz, 55 ° of shear waves detect,

Step 3: according to the voussoir delay calibration program in step 1, obtain the time of voussoir time delay with probe ripple end time beginning , in this example , ;

Step 4: remove the signal of some amplitudes lower than lower limit threshold value, adopt formula as follows:

，k∈[1,N]

Wherein , for time range [ , ] in the echoed signal obtained, for the reference amplitude of logarithmic coordinate system, for lower limit threshold value, for treated echoed signal, N is the number that comprises numerical value in x, and k is index;

Step 5: use moving average algorithm, treated echoed signal in step 4 is carried out to smoothing processing, the expression formula of moving average algorithm is as follows:

，k∈[1,N-n+1]

Wherein, x be time range [ , ] in the echoed signal obtained, y is the echoed signal after smoothing processing, N is the number that comprises numerical value in x, n is each average number that uses numerical value in moving average algorithm, k is index;

Step 6: as shown in Figure 1, after voussoir being may wear to a certain degree in this example, detection signal y time range [ , ] in maximal value and the time at maximal value place, detect that this time is approximately , and think that this time is new ultrasonic phased array voussoir delay time, and by this time redefine into , ;

Step 7: in ultrasonic phased array Non-Destructive Testing process, repeating step four, to step 6, constantly obtains new ultrasonic phased array voussoir delay time , reach the object of self-adapting ultrasonic phased array voussoir time delay.

Claims (1)

1. a method for self-adapting ultrasonic phased array voussoir time delay, is characterized in that, the method comprises the following steps:

Step 1: probe and voussoir are installed on ultrasonic phased array pick-up unit main frame, ultrasonic phased array pick-up unit is carried out to sound velocity calibration, voussoir delay calibration, sensitivity calibration and encoder calibration;

Step 2: arrange ultrasonic phased array pick-up unit time delay rule, focus on rule, gain, inhibition, initial, scope, the velocity of sound, voltage, average, scale, thickness of workpiece, workpiece material, detecting pattern, the depth of focus, probe type, probe array number, frequency probe and beam type;

Step 3: according to the voussoir delay calibration program in step 1, obtain the time t of voussoir time delay _dwith probe beginning ripple end time t _s;

Step 4: remove the signal of some amplitudes lower than lower limit threshold value, adopt formula as follows:

$x\left(k\right)=\left\{\begin{array}{cc}{x}^{\&prime;}\left(k\right),& x^{\&prime;}\left(k\right)\&GreaterEqual;i_{\min }\\ 0,& x^{\&prime;}\left(k\right)<i_{\min }\end{array}\right.,k\&Element;[1,N]$

Wherein x ' (k)=20lg (f (k)/f _ref), f (k) is time range [t _s, t _d] in the echoed signal obtained, f _reffor the reference amplitude of logarithmic coordinate system, i _minfor lower limit threshold value, x (k) is treated echoed signal, and N is the number that comprises numerical value in x, and k is index;

Step 5: use moving average algorithm, treated echoed signal in step 4 is carried out to smoothing processing, the expression formula of moving average algorithm is as follows:

$y\left(k\right)=\underset{k=1}{\overset{N-n+1}{\mathrm{\&Sigma;}}}[x\left(k\right)+x(k+1)+...+x(k+n-1)]/n,k\&Element;[1,N-n+1]$

Wherein, x is time range [t _s, t _d] in the echoed signal obtained, y is the echoed signal after smoothing processing, N is the number that comprises numerical value in x, n is each average number that uses numerical value in moving average algorithm, k is index;

Step 6: detection signal y is at time range [t _s, t _d] in maximal value and the time at maximal value place, and think that this time is new ultrasonic phased array voussoir delay time, and this time redefined as t _d;

Step 7: in ultrasonic phased array Non-Destructive Testing process, repeating step four, to step 6, constantly obtains new ultrasonic phased array voussoir delay time t _d, reach the object of self-adapting ultrasonic phased array voussoir time delay.