Portable Ultrasonic Phased Array Detection and Imaging System

Abstract

The present invention is a portable ultrasonic phased array detection and imaging system, which includes: a phased array probe module, an ultrasonic phased array circuit module, a main control module, and a display and interaction module. The probe is used to scan the workpiece to be measured, and the detection parameters are set. The circuit module calculates the focusing law, excites each element of the ultrasonic probe, and obtains the echo signal. A-scan, B-scan, and C-scan images are drawn from the echo signal. The B-scan image is subjected to coordinate transformation, 2.8-9.6 MHz band-pass filtering, and bicubic interpolation operations to obtain the S-scan image. According to various imaging methods, the defect position and shape of the workpiece to be measured can be evaluated. The ultrasonic phased array detection and imaging system has the advantages of small volume, easy to carry, simple operation, convenient parameter setting, flexible imaging mode, fast detection speed, high accuracy, etc., and is very suitable for industrial non-destructive testing.

Description

Technical Field

[0001] The present invention relates to the field of ultrasonic non-destructive testing. Aiming at inspecting the structures, properties and states of various engineering materials, structures and components at industrial sites and displaying the positions and shapes of defects in one-dimensional and two-dimensional images, specifically, it is a portable ultrasonic phased array detection and imaging system. Background Art

[0002] With the development of modern industry, higher and higher requirements are put forward for product quality, structural safety and use reliability. Non-destructive testing technology (NDT), its greatest feature is that it will not damage the object to be tested, has a wide detection range, accurate defect positioning, high sensitivity, is harmless to the human body, and can detect small defects and internal defects that cannot be observed by the naked eye, playing an increasingly important role in ensuring product quality and engineering quality. At present, non-destructive testing technology is not only applied to the manufacturing inspection and in-service inspection of boilers and pressure vessels, but also widely used in many domestic industries and departments. Such as machinery, metallurgy, oil and gas, petrochemical, chemical, aerospace, shipbuilding, railway, electric power, nuclear industry, ordnance, coal, non-ferrous metals, construction, entertainment equipment (roller coasters, etc.).

[0003] As one of the non-destructive testing methods with the highest frequency of use at home and abroad, ultrasonic non-destructive testing has experienced a stage from qualitative analysis of non-destructive flaw detection to quantitative analysis of non-destructive testing. Ultrasonic non-destructive testing was first applied to radar. In a phased array radar, many sub-antenna units are arranged in a specific shape. By controlling the amplitude and delay of the electromagnetic waves emitted by each sub-antenna, the phase of each electromagnetic wave is adjusted, so as to realize the flexible synthesis of a focused scanning radar beam. Drawing on the beam synthesis of radar, ultrasonic phased array detection technology controls the elements in the ultrasonic phased array probe array through an electronic system, and emits and receives ultrasonic waves according to a certain delay time rule, so as to dynamically control the deflection and focusing of the ultrasonic beam in the workpiece. Its detection speed is fast, the detection flexibility is strong, and it can realize the detection of defects in complex structural parts and blind areas.

[0004] Modern ultrasonic non-destructive testing technology is developing towards the direction of digitization, automation, intelligence and systematization. The reliability of positioning, qualitative analysis and quantitative analysis in material defect detection will be continuously improved, making it better play a huge role in industrial fields such as nuclear energy, aviation, electric power, and machinery. Summary of the Invention

[0005] The purpose of the present invention is to meet the current needs of the industrial field for the development of portable instruments, and a small, simple, convenient and easy-to-operate ultrasonic phased array detection and imaging system is developed to meet the current requirements of non-destructive testing.

[0006] The technical solution of the present invention is as follows:

[0007] A portable ultrasonic phased array detection and imaging system, the main components of which include: an ultrasonic phased array probe, an ultrasonic phased array circuit module, a main control module, and a display and interaction module. Among them, the phased array probe is connected to the phased array circuit system through a coaxial circuit, the phased array circuit module is connected to the main control module, the main control module is connected to the display and interaction module, and the display and interaction module is embodied through a touch screen.

[0008] The specific detection process of this portable ultrasonic phased array detection and imaging system is as follows:

[0009] Step 1: Use the ultrasonic probe to scan the workpiece to be measured, set the detection parameters, the circuit module calculates the focusing law, excites each element of the ultrasonic probe, emits ultrasonic waves to the workpiece to be measured, and obtains echo signals;

[0010] Step 2: Draw A-scan, B-scan, and C-scan images from the echo signals. The B-scan image is obtained through coordinate transformation, 2.8 - 9.6 MHZ band-pass filtering, and bicubic interpolation operations to obtain the S-scan image.

[0011] Step 3: Evaluate the defect position and shape of the workpiece to be measured according to various imaging methods.

[0012] The present invention also has the following technical features:

[0013] 1) The main control module uses an ARM chip, the ultrasonic phased array circuit system uses an FPGA chip, and the display and interaction module uses an embedded design based on the Linux and QT platforms.

[0014] 2) The system's main control unit is composed of a circuit module, a main control module, and a display and interaction module. According to the requirements of the workpiece to be detected and the hardware device, detailed parameters are configured in the display and interaction module, and the main control module issues parameter instructions, and the circuit module calculates the focusing law and gives out transmit / receive ultrasonic control signals.

[0015] 3) The ultrasonic phased array probe is a linear array with a working frequency of 5 MHZ and 32 elements, and is composed of a probe, a cable, a housing, and its accessories.

[0016] 4) The display and interaction module includes a parameter interface, an image display interface, an image display selection interface, a data saving interface, a basic information display interface, etc. The display and interaction module can flexibly provide four different display methods for the defect image: A-scan, B-scan, C-scan, and S-scan, and can save defect data and images.

[0017] Compared with the existing ultrasonic phased array imaging system, the present invention has the following obvious advantages:

[0018] 1) The ultrasonic phased array detection and imaging system uses ultrasonic transducers composed of multiple linear arrays. By using different focusing delays, sound beams with different deflection angles and focusing can be generated, enabling the scanned object to be scanned across a certain cross-section without movement. This feature reduces detection errors caused by manual operation and improves measurement accuracy.

[0019] 2) The defect display part of the present invention incorporates image processing technology, making defects more legible and easier to locate.

[0020] 3) The defect display part of the present invention is relatively flexible and can be customized according to the operator's needs. It can display up to 4 different display methods simultaneously and ensure the accuracy and real-time nature of the detection and imaging results. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is the overall structure diagram of the ultrasonic phased array detection and imaging system in the embodiment.

[0022] Figure 2 is the ultrasonic phased array scanning mode diagram.

[0023] Figure 3 is the ultrasonic phased array S-scan imaging coordinate conversion diagram.

[0024] Figure 4 is the bicubic interpolation principle diagram.

[0025] Figure 5 is the fan scan diagram after bicubic interpolation processing.

[0026] Figure 6 is the implementation diagram of the fan scan of the portable ultrasonic phased array detection and imaging system.

[0027] Figure 7 is the geometric schematic diagram of the B-type test block.

[0028] Figure 8 is the schematic diagram of various imaging displays of the portable ultrasonic phased array detection and imaging system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in more detail with reference to the accompanying drawings as follows:

[0030] Combined with Figure 1 , the portable ultrasonic phased array detection and imaging system includes: a main control module, an ultrasonic phased array circuit module, an ultrasonic phased array probe, and a display and interaction module. The ultrasonic phased array probe is connected to the ultrasonic phased array circuit module through a coaxial cable. The ultrasonic phased array circuit module is connected to the main control module, and the main control module is connected to the display and interaction module, which is embodied by a touch screen.

[0031] Display interaction module: It adopts embedded design based on Linux and QT platform. According to the detection requirements, the software interface menu parameters can be set through the touch screen. The main parameters of the probe and wedge can be set: the number of array elements, array element spacing, wedge angle, wedge first array element height, wedge sound velocity, sound velocity of the object to be measured, sector scanning range, angle step, etc.; set the parameters of the ultrasonic phased array scanning working mode: focusing mode, focusing depth, etc.; set the parameters of the image display mode: display type, display combination, etc.; set the general parameters of ultrasonic phased array detection: gain, sampling range, pulse repetition frequency, etc. Among them, the ultrasonic phased array scanning working mode is divided into three types, such as Figure 2 Image display types include A-scan, B-scan, C-scan, and S-scan, which can be displayed in any combination. The main function of the display interaction module is to set detection parameters and transmit them to the main control module, display echo data, and realize human-computer interaction.

[0032] Main control module: The main control module uses an ARM chip and sends the parameters set by the user to the circuit module; it receives the echo signal from the circuit module and sends it to the display interaction module for display.

[0033] Ultrasonic phased array circuit module: The circuit module uses an FPGA chip. Based on the configuration parameters sent by the main control module, it calculates the focusing law and sends the detection control information to the ultrasonic transmitting / receiving circuit. The ultrasonic transmitting / receiving circuit generates a corresponding electrical pulse signal based on the control signal, thereby controlling the ultrasonic phased array probe and collecting the detection echo data.

[0034] Ultrasonic phased array probe: Apply an appropriate amount of coupling agent to the object being measured and the probe surface, place it vertically on the surface of the workpiece being measured, and control the phase delay of each array element according to the focal law to generate an ultrasonic beam with corresponding deflection angle and focal length.

[0035] In the embodiment, the display interaction module can display four imaging modes in real time, namely A scan, B scan, C scan and S scan. For S scan imaging, it is necessary to convert the coordinates from the B scan and fill the S scan matrix one by one according to the B scan matrix data. In this process, neither the original image information can be missed nor the new image information can be added. Figure 3 The coordinate transformation is performed based on the principle of B-scan coordinate system 1. The pixel point (x, y) in the data matrix of S-scan coordinate system 2 corresponds to the pixel point (x′, y′). Assume that the sampling sequence length of each deflection angle in coordinate system 2 is L, where θ0 is the starting angle and θ end is the ending angle, Δθ is the angle step, and N is the number of sampling points. The corresponding coordinate transformation relationship is:

[0036]

[0037]

[0038]

[0039] Converting the B-scan imaging through coordinate transformation to obtain the S-scan imaging is a process of obtaining the target image matrix from the original image matrix. In this process, it cannot be guaranteed that the positions of the S-scan polar coordinates and the pixel points of the B-scan are in one-to-one correspondence. Therefore, there may be some pixel points with undetermined values in the sector scan image after coordinate transformation, and these pixel points seriously affect the image quality. To make up for the problem that the pixel points of the original image and the target image do not completely correspond, image interpolation processing needs to be carried out. Bi-cubic interpolation is adopted, and its principle is as Figure 4 shown. The pixel values of 4*4 integer points around the floating-point coordinate point are used to calculate the target pixel value.

[0040] The interpolation of the floating-point coordinate point is the weighted sum of the pixel values of the 4*4 integer coordinate points around it:

[0041]

[0042] Among them, the calculation of the weight is as follows. The value range of a is between -1 and 0, and generally a fixed value of -0.5 is taken.

[0043] W(i, j) = W(d xi ) * W(d yj )

[0044]

[0045] d xi = x i - x'

[0046] d yj = y j - y'

[0047] The sector scan image after bi-cubic interpolation is as Figure 5 .

[0048] Furthermore, the specific detection process of the portable ultrasonic phased array detection imaging system is as follows:

[0049] Step 1: Place the workpiece to be detected, determine the defect area to be detected, install the probe on the wedge block, apply a coupling agent on the contact surface between the wedge block and the object to be detected, place the phased array probe and the wedge block on the object to be detected, turn on the system power supply, and set parameters through the display and interaction module according to the detection requirements;

[0050] Step 2: The main control module receives the parameters from the display and interaction module, sends them to the ultrasonic phased array circuit module. The circuit module calculates the focusing law according to the parameters, and transfers the calculation result to the transmitting circuit, and then controls the ultrasonic phased array probe to emit corresponding sound beams;

[0051] Step 3: The sound beam generated by the ultrasonic phased array probe propagates in the object under test and is reflected back when it touches the internal defect. After being processed by the receiving circuit according to the receiving delay, a detection echo signal is obtained.

[0052] Step 4: The echo signal is transmitted to the main control module, and the main control module then transmits the signal to the display and interaction module for defect imaging display.

[0053] Step 5: A-scan, B-scan, and C-scan images are drawn from the echo signal. The B-scan image is subjected to coordinate transformation, 2.8 - 9.6 MHZ band-pass filtering, and bicubic interpolation operations to obtain the S-scan image.

[0054] Step 6: The defect position and shape of the workpiece under test can be evaluated according to multiple imaging methods.

[0055] Combined with Figure 6 , in this embodiment, a phased array probe with 32 elements, a working frequency of 5 MHZ, a wedge angle of 36°, and a sound velocity of 2337 m / s in the wedge is used. The probe is installed on the wedge and coupled with the object under test using a coupling agent. The object under test is one of the standard test blocks used in international ultrasonic phased array instruments: B-type test block, and the geometric diagram is as shown in Figure 7 . Equal-path fan-shaped scanning is performed on the vertical through holes in the B-type test block for detection imaging. The deflection angle is 35° - 70°, the angle step is 1°, there are 36 scan lines in total, and the focusing depth is 25 mm. The results of the detection by the embodiment system are as follows:

[0056] The results are as shown in Figure 8 . It can be clearly seen from the figure that there are 10 through holes, and there is no obvious missed detection. The measured defect size and shape do not show obvious stretching or compression, and the vertical distance between adjacent two through holes also conforms to the actual situation. Moreover, the A-scan, B-scan, S-scan, and C-scan images can be observed simultaneously, which can further supplement the defect information.

[0057] From the above detection results, it can be seen that the embodiment system can detect the defects of the test block and can reflect the defect shape and position information.

Claims

1. A portable ultrasonic phased array detection and imaging system, characterized in that The specific steps are as follows: Use an ultrasonic probe to scan the workpiece to be measured, set the detection parameters, the circuit module calculates the focusing law, excites each element of the ultrasonic probe, emits ultrasonic waves to the workpiece to be measured, and obtains the echo signal; Draw A-scan, B-scan, and C-scan images from the echo signal, and the B-scan image is subjected to coordinate transformation, 2.8-9.6 MHZ band-pass filtering, and bicubic interpolation operations to obtain the S-scan image; Evaluate the defect position and shape of the workpiece to be measured according to various imaging methods; Among them, for the S-scan imaging, the S-scan matrix is filled one by one through the B-scan matrix data, and the coordinate transformation is carried out with reference to the following principle. The pixel point (x, y) in the B-scan coordinate system 1 corresponds to the pixel point (x′, y′) in the data matrix of the S-scan coordinate system 2. Assume that the sampling sequence length of each deflection angle in the coordinate system 2 is L, where θ0 is the starting angle, θ end is the termination angle, Δθ is the angle step, and N is the number of sampling points. The corresponding coordinate transformation relationship is:

2. The portable ultrasonic phased array detection and imaging system according to claim 1, wherein The main components include an ultrasonic phased array probe, an ultrasonic phased array circuit module, a main control module, and a display and interaction module; the display module sets detection parameters and displays echo data; the main control module sends the detection parameters to the circuit module, receives the echo data, and hands it over to the display module for display; the circuit module calculates the focusing rule, excites each element of the probe, collects the echo data, and transmits it to the main control module.

3. The portable ultrasonic phased array detection and imaging system according to claim 1, characterized in that, The ultrasonic phased array circuit module calculates the delay time of each element of the ultrasonic phased array probe according to the deflection angle and focusing depth set by the display and interaction module.

4. The portable ultrasonic phased array detection and imaging system according to claim 1, characterized in that, The display and interaction module displays four imaging modes in real time, namely A-scan, B-scan, C-scan, and S-scan, and flexibly combines multiple imaging modes.

5. The portable ultrasonic phased array detection and imaging system according to claim 1, wherein The B-scan image is transformed through coordinate transformation to obtain the S-scan image. To address the issue that the pixel points of the original image and the target image do not exactly correspond, bicubic interpolation is adopted, and the pixel values of 4*4 integer points around the floating-point coordinate points are used to calculate the target pixel value.

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