On-line automatic bar flaw detection method and device based on full-focusing phased array technology

Abstract

The invention relates to the technical field of full-focusing phased arrays, and discloses an on-line automatic bar flaw detection method and device based on a full-focusing phased array technology. According to the method, after water immersion type coupling is carried out, array elements of a concave array phased array probe are excited in a plane wave emission mode, multi-angle acoustic beams are formed, and full-matrix echo data are captured; for transverse wave detection, the sound field uniformity is improved by adopting a grouped alternate emission mechanism. Full-domain dynamic focusing is realized through coherent superposition processing, and real-time alarm and mark spraying are carried out on standard exceeding defects in combination with encoder data. The device comprises an off-line automatic calibrator, a conveying roller way, a steel splitting instrument platform, a pinch roll system, a lifting transverse moving platform, an ultrasonic detection host, a mark spraying system, a water circulation system and a PLC system, and efficient and accurate on-line bar flaw detection is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of total focusing phased array technology and discloses an online automatic flaw detection method and device for bars based on the total focusing phased array technology. Background Art

[0002] Ultrasonic nondestructive testing (NDT) has become the mainstream technology for bar testing due to its advantages, including strong penetration, high resolution, good sensitivity, and high safety. However, conventional ultrasonic testing is limited by the number and angle of probes, which carries the risk of missed defects. While traditional ultrasonic phased array technology expands the detection range through electronic deflection and focusing, its full-matrix acquisition method requires sequentially stimulating array elements and receiving signals from the entire array, resulting in large data volumes and low detection efficiency. Summary of the Invention

[0003] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide an online automatic flaw detection method for bars based on full-focusing phased array technology, which solves the problem of low detection efficiency of traditional ultrasonic phased array technology in the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions: In a first aspect, the present invention provides an online automatic flaw detection method for bars based on a total focusing phased array technology, the method comprising: Water immersion coupling of the rod in the ultrasonic testing host; The ultrasonic testing host comprises concave phased array probes that are evenly distributed and staggered in the circumferential direction; After immersion coupling, the ultrasonic testing host adopts plane wave transmission mode to excite the array elements of the concave phased array probe, generating plane waves covering the imaging area. Through three independent transmissions, a vertically incident longitudinal wave beam, a forward-inclined shear wave beam, and a reverse-inclined shear wave beam are formed respectively. The longitudinal wave beam is excited by all array elements simultaneously, and the corresponding received signals form the echo signals of the longitudinal wave beam; The shear wave acoustic beam adopts a dual-focus mechanism, dividing all array elements into two groups for alternating excitation. Each group of array elements excites a portion of the imaging area. The plane waves generated by the excitation of the two groups of array elements cover the entire imaging area. The received signals corresponding to the excitation of the two groups of array elements are superimposed to form the echo signal of the shear wave acoustic beam. All array elements receive echo signals; The transmission path delay and the receiving path delay are calculated based on the plane wave and the echo signal at the imaging point in the imaging area, and dynamic focus imaging is achieved through coherent superposition processing; Based on the focused imaging results combined with the encoder data, a real-time alarm is issued for defects exceeding the standard, and the position is marked through the marking system.

[0005] Preferably, in a possible implementation manner of the first aspect, the water immersion coupling specifically includes: A water cavity is formed at the edge of the detection cavity by coupling water with tangential incidence; When the rod enters the detection cavity, it fills the water cavity space, forming an air-free coupling environment; The high-speed flowing coupling water wraps the rod and removes air bubbles; The coupled water is filtered, temperature controlled and recycled through the water circulation system.

[0006] Preferably, in a possible implementation manner of the first aspect, the water circulation system comprises a sedimentation sewage tank, an intermediate filtration water tank and a main water tank; The sedimentation sewage tank collects the coupled water with impurities and precipitates it; The intermediate filter water tank purifies the water through backwash bag filters; The main water tank is equipped with a drum-type paper belt filter, water cooling and heating system to maintain the cleanliness and temperature of the coupling water.

[0007] Preferably, in a possible implementation manner of the first aspect, the plane wave emission mode includes multi-angle composite emission: Improving imaging signal-to-noise ratio by transmitting plane waves at different tilt angles; Each transmission uses a full matrix capture method to record the echo signals received by all array elements.

[0008] Preferably, in a possible implementation manner of the first aspect, the dual-focus mechanism is applied to a shear wave acoustic beam, specifically including: Divide all array elements into two groups of array elements; The two groups of array elements are alternately excited to cover different areas in the imaging area, forming two focal regions; The two focal areas overlap to cover the entire imaging area; The received signals of the two transmissions are superimposed to balance the energy distribution of the sound field.

[0009] Preferably, in a possible implementation manner of the first aspect, the coherent superposition processing specifically includes: Calculate the transmission path delay and the receiving path delay for each imaging point in the imaging area; Performing a delayed sum operation on the echo signals received by all array elements based on the delay data; Point-by-point dynamic focusing is achieved through weighted superposition.

[0010] Preferably, in a possible implementation manner of the first aspect, the coherent superposition process further includes a data buffering mechanism: Adopt software and hardware layered buffer design to optimize image data transmission; Data processing and scheduling are performed through an independent buffer layer.

[0011] In a second aspect, the present invention provides an online automatic flaw detection device for bars based on total focusing phased array technology, the device being used to implement the online automatic flaw detection method for bars based on total focusing phased array technology in the first aspect, comprising an offline automatic calibrator, a conveyor roller, a steel separator platform, a pinch roller system, a lifting and traversing platform, an ultrasonic testing host, a spray marking system, a water circulation system, and a PLC system; The offline automatic calibrator is equipped with a transverse feed unit, a circumferential rotation unit and a bar clamping unit for probe calibration and verification. The conveyor roller is equipped with gratings at the head and tail to automatically identify the bar position signal and record the probe information in real time through the encoder; The steel separator platform integrates a traverse mechanism and a lifting mechanism to adapt to the center height changes of bars with different diameters; The pinch roller system is used to ensure smooth passage of bars through the inspection area; The lifting and traversing platform adjusts the center height of the ultrasonic testing host and supports traversing the equipment offline; The ultrasonic testing host uses a concave phased array probe with circumferentially uniformly staggered arrangements to form an immersion coupling environment. The tangentially incident coupling water forms a stable water cavity at the edge, and the high-speed flowing coupling water removes bubbles. The marking system sprays and marks the defects exceeding the standard in real time; The water circulation system consists of a sedimentation and drainage tank, an intermediate filtration water tank, and a main water tank. The main water tank includes a drum-type paper belt filter, cooling and heating devices to maintain the cleanliness and temperature of the coupling water. The PLC system is used for automatic control, safety protection and human-machine interface interaction, and displays equipment status and defect alarm information in real time.

[0012] The beneficial effect of the present invention is that the concave phased array probes with circumferentially uniformly distributed and staggered arrangements are used in combination with immersion coupling detection to achieve all-round detection of rods and effectively avoid missed defects.

[0013] Secondly, the combination of plane wave emission mode and full-matrix capture technology completes multi-angle detection with only three independent emissions, greatly improving the detection speed.

[0014] At the same time, the dual-focus mechanism of alternating group emission effectively improves the uniformity of the sound field and enhances the ability to detect edge defects.

[0015] Ultimately, by using a layered buffer design of software and hardware and an independent buffer layer to process and schedule data, data transmission congestion was avoided, ensuring real-time data processing capabilities in a high-speed production line environment, and overall improving the reliability and stability of the flaw detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A flow chart of an online automatic flaw detection method for bars based on full-focusing phased array technology is provided for this application.

[0018] Figure 2 A schematic diagram of plane wave imaging full-focus flaw detection of rods is provided for this application. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Example 1: Figure 1 As shown, the present invention provides an online bar automatic flaw detection method based on full-focusing phased array technology, comprising: The rod is water-immersed in an ultrasonic testing host, which includes concave phased array probes that are evenly distributed and staggered in the circumferential direction.

[0021] In this embodiment, 4-8 concave phased array probes are evenly spaced and staggered along the circumference of the rod, achieving 360° full coverage and forming overlapping coverage areas. The probe assembly is installed within the ultrasonic testing mainframe, and tangentially incident coupling water forms a stable annular water cavity at the edge of the detection cavity. When the rod enters the detection cavity at a constant speed, its outer surface directly fills the water cavity, replacing the existing air area and forming an air-free coupling environment. The coupling water wraps around the rod surface with a high-speed tangential flow. The rotating water flow quickly removes bubbles and impurities attached to the rod surface, ensuring a stable coupling interface.

[0022] The coupling medium is dynamically purified using a circulating water system. The system consists of a three-stage system: a sedimentation and drainage tank, an intermediate filtration tank, and a main water tank. Impure coupling water first flows into the sedimentation and drainage tank below ground level, where solid impurities such as iron oxide scale are separated by gravity. The initially purified water is then pumped to the intermediate filtration tank for secondary filtration via a backwash bag filter. Finally, it flows into the main water tank for fine filtration via a drum paper filter. The main water tank is equipped with a temperature control module, which maintains a constant temperature for the coupling water through an integrated water cooler and heater, ensuring stable ultrasonic propagation. The tertiary-treated coupling water is then re-injected into the detection chamber via a closed-loop pipeline, achieving water recycling.

[0023] After immersion coupling, the ultrasonic testing host adopts a plane wave transmission mode to excite the array elements of the concave phased array probe, generating plane waves covering the imaging area. Through three independent transmissions, a vertically incident longitudinal wave beam, a forward-inclined shear wave beam, and a reverse-inclined shear wave beam are formed respectively, and all array elements receive echo signals.

[0024] In this embodiment, the plane wave transmission mode is achieved by controlling the excitation timing of all array elements of the concave phased array probe. All array elements excite a non-focused plane wave beam, generating a plane wave that covers the entire imaging area of ​​the rod. To achieve multi-angle composite transmission and improve the imaging signal-to-noise ratio, the system uses three independent transmission sequences: the first transmission forms a vertically incident longitudinal wave beam through a zero-delay setting. , used to detect longitudinal defects inside the bar; the second emission adds a forward tilt delay to stimulate the forward tilted shear wave beam , covering the positive angle area of ​​the rod; the third transmission adds a reverse tilt delay to generate a reverse tilted shear wave beam , covering the reverse angle area. The schematic diagram of plane wave imaging full focus flaw detection of rods is as follows Figure 2 By superimposing sound beams in different tilt directions, the signal-to-noise ratio for complex defects is enhanced while avoiding clutter interference.

[0025] After each transmission, all array elements capture the full matrix echo data, that is, the original signals of all transmit-receive combinations are fully recorded to form a full matrix data set. Data acquisition adopts the full matrix capture method, and the echo signal received by each array element is completely stored in the system memory. The entire capture process is processed at high speed by the phased array electronic unit. Through the optimized buffer design, continuous image data transmission congestion is avoided, ensuring real-time data recording in a high-speed production line environment. Finally, this mode is completed with three transmissions. 、 and Compared with traditional phased array detection, which requires dozens of focusing laws, tri-mode detection improves detection efficiency while maintaining high resolution and signal-to-noise ratio, achieving accurate identification of tiny defects below 0.5mm.

[0026] The longitudinal wave beam uses all array elements to excite simultaneously, and the corresponding received signals form the echo signals of the longitudinal wave beam. The shear wave beam uses a dual-focus mechanism to divide all array elements into two groups of array elements for alternating excitation. The excitation of each group of array elements covers a part of the imaging area. The plane waves generated by the excitation of the two groups of array elements cover the entire imaging area. The received signals corresponding to the excitation of the two groups of array elements are superimposed to form the echo signals of the shear wave beam.

[0027] In this embodiment, in the longitudinal wave detection mode, all array elements are excited simultaneously, and the formed acoustic beam focus covers the entire rod imaging area, and the corresponding received signal forms the echo signal of the longitudinal wave acoustic beam.

[0028] In shear wave detection mode, the system uses a dual-focus mechanism, dividing all probe elements into two groups, each containing half the number of elements. The system performs group alternating excitation, with the two groups of elements alternately exciting different areas within the imaging area to form two focal areas. The two focal areas overlap to cover the entire imaging area. Because there are two focal areas, the shear wave energy is not as concentrated as with a single focal area, allowing the shear wave energy to cover a wider area and increasing the signal strength at the edge of the imaging area. Finally, the received signals corresponding to the two groups of excitations are superimposed to form the echo signal of the shear wave beam. This grouping design solves the problem of excessive concentration of shear wave energy in the center and weakening of edge signals in the single all-transmit and all-receive mode by optimizing the sound field distribution, thus avoiding the risk of calibration failure due to excessive differences in center and edge intensity during calibration.

[0029] The transmission path delay and the receiving path delay are calculated based on the plane wave and the echo signal for the imaging point in the imaging area, and dynamic focusing imaging is achieved through coherent superposition processing.

[0030] In this embodiment, the system implements a full-focusing algorithm. For each imaging point within the imaging area, the transmission path delay is first calculated. This delay corresponds to the propagation time of the plane wave from the probe's virtual source point to the target imaging point. Simultaneously, the reception path delay is calculated, i.e., the time it takes for the ultrasonic echo to propagate from the target imaging point to each receiving element, covering all possible transmission-reception combinations. Subsequently, based on the delay data, a delayed summation operation, i.e., coherent superposition processing, is performed on the received signals of all elements. Corresponding delay weights are applied to all received signals, and pixel-level dynamic focusing is achieved through weighted superposition. Each imaging point achieves optimal focusing, thereby achieving full-domain high-resolution imaging throughout the entire imaging area, improving the accuracy and signal-to-noise ratio of defect detection.

[0031] In addition, to optimize image data transmission and avoid processing bottlenecks, this embodiment adopts a data buffering mechanism. A software and hardware layered buffering design is used to optimize image data transmission, and data processing and scheduling are performed through an independent buffer layer to avoid congestion in continuous image data transmission. Specifically, the hardware layer implements a real-time data stream buffer storage mechanism to ensure that high-speed acquisition signals are not lost or interrupted. The independent buffer layer coordinates data queue management and logical isolation to achieve parallel processing and efficient scheduling, while the software layer optimizes the process and dynamically adjusts resource allocation to adapt to different load requirements. Through this mechanism, the system maintains high frame rate imaging while ensuring the reliability of real-time data processing and recording, and is seamlessly integrated into the online detection process.

[0032] Based on the focused imaging results combined with the encoder data, a real-time alarm is issued for defects exceeding the standard, and the position is marked through the marking system.

[0033] In this embodiment, the system collects bar position data in real time via encoders on the conveyor rollers. Grating devices automatically identify bar head and tail signals at the roller head and tail, ensuring synchronized position recording. When the ultrasonic testing host identifies an out-of-specification defect while processing full-matrix echo data, the PLC system, combined with the encoder information, locates the defect's axial and circumferential coordinates on the bar. The system triggers a real-time alarm mechanism, displaying the device status, alarm channel number, and defect type on the human-machine interface for immediate warning. Simultaneously, the marking system activates, spraying a special ink mark at the defect's real-time location based on the positioning data, ensuring that the mark corresponds exactly to the defect's location.

[0034] Example 2: The present invention provides an online automatic bar flaw detection device based on full-focusing phased array technology, including an offline automatic calibrator, a conveyor roller, a steel separator platform, a pinch roller system, a lifting and transverse movement platform, an ultrasonic detection host, a spray marking system, a water circulation system and a PLC system.

[0035] The offline automatic calibrator is equipped with a transverse feed unit, a circumferential rotation unit and a bar clamping unit for probe calibration and verification. The conveyor roller is equipped with gratings at the head and tail to automatically identify the bar position signal and record the probe information in real time through the encoder; The steel separator platform integrates a traverse mechanism and a lifting mechanism to adapt to the center height changes of bars with different diameters; The pinch roller system is used to ensure smooth passage of bars through the inspection area; The lifting and traversing platform adjusts the center height of the ultrasonic testing host and supports traversing the equipment offline; The ultrasonic testing host uses a concave phased array probe with circumferentially uniformly staggered arrangements to form an immersion coupling environment. The tangentially incident coupling water forms a stable water cavity at the edge, and the high-speed flowing coupling water removes bubbles. The marking system sprays and marks the defects exceeding the standard in real time; The water circulation system consists of a sedimentation and drainage tank, an intermediate filtration water tank, and a main water tank. The main water tank includes a drum-type paper belt filter, cooling and heating devices to maintain the cleanliness and temperature of the coupling water. The PLC system is used for automatic control, safety protection and human-machine interface interaction, and displays equipment status and defect alarm information in real time.

[0036] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. An online bar automatic flaw detection method based on full-focusing phased array technology is characterized by: The method comprises: Water immersion coupling of the rod in the ultrasonic testing host; The ultrasonic testing host comprises concave phased array probes that are evenly distributed and staggered in the circumferential direction; After immersion coupling, the ultrasonic testing host adopts plane wave transmission mode to excite the array elements of the concave phased array probe, generating plane waves covering the imaging area. Through three independent transmissions, a vertically incident longitudinal wave beam, a forward-inclined shear wave beam, and a reverse-inclined shear wave beam are formed respectively. The longitudinal wave beam is excited by all array elements simultaneously, and the corresponding received signals form the echo signals of the longitudinal wave beam; The shear wave acoustic beam adopts a dual-focus mechanism, dividing all array elements into two groups for alternating excitation. Each group of array elements excites a portion of the imaging area. The plane waves generated by the excitation of the two groups of array elements cover the entire imaging area. The received signals corresponding to the excitation of the two groups of array elements are superimposed to form the echo signal of the shear wave acoustic beam. All array elements receive echo signals; The transmission path delay and the receiving path delay are calculated based on the plane wave and the echo signal at the imaging point in the imaging area, and dynamic focus imaging is achieved through coherent superposition processing; Based on the focused imaging results combined with the encoder data, a real-time alarm is issued for defects exceeding the standard, and the position is marked through the marking system.

2. The online automatic flaw detection method for bars based on total focusing phased array technology according to claim 1 is characterized in that: The water immersion coupling specifically includes: A water cavity is formed at the edge of the detection cavity by coupling water with tangential incidence; When the rod enters the detection cavity, it fills the water cavity space, forming an air-free coupling environment; The high-speed flowing coupling water wraps the rod and removes air bubbles; The coupled water is filtered, temperature controlled and recycled through the water circulation system.

3. The online automatic flaw detection method for bars based on total focusing phased array technology according to claim 2 is characterized in that: The water circulation system comprises a sedimentation sewage tank, an intermediate filtration water tank and a main water tank; The sedimentation sewage tank collects the coupled water with impurities and precipitates it; The intermediate filter water tank purifies the water through backwash bag filters; The main water tank is equipped with a drum-type paper belt filter, water cooling and heating system to maintain the cleanliness and temperature of the coupling water.

4. The online bar automatic flaw detection method based on total focusing phased array technology according to claim 1 is characterized in that: The plane wave emission mode includes multi-angle composite emission: Improving imaging signal-to-noise ratio by transmitting plane waves at different tilt angles; Each transmission uses a full matrix capture method to record the echo signals received by all array elements.

5. The online automatic flaw detection method for bars based on total focusing phased array technology according to claim 1 is characterized in that: The dual-focus mechanism is applied to the shear wave acoustic beam and specifically includes: Divide all array elements into two groups of array elements; The two groups of array elements are alternately excited to cover different areas in the imaging area, forming two focal regions; The two focal areas overlap to cover the entire imaging area; The received signals of the two transmissions are superimposed to balance the energy distribution of the sound field.

6. The online bar automatic flaw detection method based on total focusing phased array technology according to claim 1 is characterized in that: The coherent superposition processing specifically includes: Calculate the transmission path delay and the receiving path delay for each imaging point in the imaging area; Performing a delayed sum operation on the echo signals received by all array elements based on the delay data; Point-by-point dynamic focusing is achieved through weighted superposition.

7. The online automatic flaw detection method for bars based on total focusing phased array technology according to claim 6 is characterized in that: The coherent addition process also includes a data buffering mechanism: Adopt software and hardware layered buffer design to optimize image data transmission; Data processing and scheduling are performed through an independent buffer layer.

8. The online bar automatic flaw detection device based on full-focus phased array technology is characterized by: The device is used to implement the online automatic bar flaw detection method based on the total focusing phased array technology according to any one of claims 1 to 7, comprising an offline automatic calibrator, a conveyor roller, a steel separator platform, a pinch roller system, a lifting and traversing platform, an ultrasonic testing host, a spray marking system, a water circulation system, and a PLC system; The offline automatic calibrator is equipped with a transverse feed unit, a circumferential rotation unit and a bar clamping unit for probe calibration and verification. The conveyor roller is equipped with gratings at the head and tail to automatically identify the bar position signal and record the probe information in real time through the encoder; The steel separator platform integrates a traverse mechanism and a lifting mechanism to adapt to the center height changes of bars with different diameters; The pinch roller system is used to ensure smooth passage of bars through the inspection area; The lifting and traversing platform adjusts the center height of the ultrasonic testing host and supports traversing the equipment offline; The ultrasonic testing host uses a concave phased array probe with circumferentially uniformly staggered arrangements to form an immersion coupling environment. The tangentially incident coupling water forms a stable water cavity at the edge, and the high-speed flowing coupling water removes bubbles. The marking system sprays and marks the defects exceeding the standard in real time; The water circulation system consists of a sedimentation and drainage tank, an intermediate filtration water tank, and a main water tank. The main water tank includes a drum-type paper belt filter, cooling and heating devices to maintain the cleanliness and temperature of the coupling water. The PLC system is used for automatic control, safety protection and human-machine interface interaction, and displays equipment status and defect alarm information in real time.

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