Deep-sea mining pipe lining nondestructive testing device based on coplanar capacitance technology

Abstract

The invention provides a deep-sea mining pipe lining nondestructive testing device based on a coplanar capacitance technology, and belongs to the technical field of nondestructive detection.The device comprises a cylindrical telescopic capacitor array detection probe, a main control bin and a carrying device, and the carrying device is connected with the main control bin through a universal connecting rod; the main control bin is connected with the capacitor array detection probe through a universal connecting rod; the cylindrical telescopic capacitor array detection probe comprises a spring inner cylinder, carrying discs and sub-probes, the carrying discs are connected to the two ends of the spring inner cylinder, the sub-probes are connected to the outer side of the spring inner cylinder, and power pulleys and FPCB polar plates are arranged on the outer surfaces of the sub-probes. By adopting the deep-sea mining pipe lining nondestructive testing device based on the coplanar capacitance technology, the problem of nondestructive automatic detection of defects of a nylon layer of a submarine mining pipe lining is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nondestructive testing, in particular to a deep-sea mining pipe lining nondestructive testing device based on coplanar capacitance technology. BACKGROUND

[0002] With the gradual depletion of land mineral resources, seabed mineral resources such as polymetallic nodules, cobalt-rich crusts and seabed sulfides, due to their huge application prospects, have gradually become a key component of national strategic resource reserves. The safety and reliability of deep-sea mining systems, as the core equipment for developing these resources, are of great importance. Among them, the nylon layer of the mining pipe inner layer is prone to defects, pits and other problems under the long-term impact and corrosion of the environment, which can cause safety accidents and property losses in severe cases. Therefore, effective detection of the nylon layer of the seabed mining pipe lining has become an urgent need.

[0003] Traditional nondestructive testing techniques, such as ultrasonic testing, infrared thermal imaging, radiographic testing, optical testing and microwave testing, have their own advantages, but they all have limitations when detecting the nylon layer of the seabed mining pipe lining. For example, ultrasonic testing requires high material surface flatness, infrared thermal imaging has limited ability to detect deep defects, radiographic testing has radiation risks and is not sensitive to small defects, optical testing is only suitable for surface defects, and microwave testing has low resolution.

[0004] As a new nondestructive testing technology, coplanar capacitance detection technology detects defects in samples by sensing the changes in the quasi-static edge electric field between coplanar plates, and has the advantages of being suitable for automated scanning, having low environmental requirements, being able to quantify defects, being simple in technology and being sensitive to surface defects. In recent years, with the progress of material science, electronic technology and computer algorithms, coplanar capacitance detection technology has made significant progress in many fields, but there is still a lack of automated devices and methods for detecting deep-sea mining pipe lining in specific places such as deep-sea mining pipe lining.

[0005] Therefore, it is of great significance to develop a deep-sea mining pipe lining nondestructive testing device and method based on coplanar capacitance technology to ensure the safety of deep-sea mining and improve the efficiency of resource development. SUMMARY

[0006] The present application aims to provide a deep-sea mining pipe lining nondestructive testing device based on coplanar capacitance technology, which solves the problem of nondestructive automated detection of defects in the nylon layer of the seabed mining pipe lining.

[0007] To achieve the above objectives, the present invention provides a non-destructive testing device for the lining of deep-sea mining pipes based on coplanar capacitance technology. The device includes a cylindrical telescopic capacitance array detection probe, a main control chamber, and a mount. The mount is connected to the main control chamber via a universal connecting rod, and the main control chamber is connected to the capacitance array detection probe via a universal connecting rod. The cylindrical telescopic capacitance array detection probe includes a spring inner cylinder, a mounting disk, and a sub-probe. The mounting disk is connected to both ends of the spring inner cylinder, and the sub-probe is connected to the outer side of the spring inner cylinder. The outer surface of the sub-probe is provided with a power pulley and an FPCB electrode plate.

[0008] Preferably, the sub-probe includes a housing, a top cover on the top of the housing, the housing being fixedly connected to the top cover by screws, power pulleys embedded on both ends of the top cover, an FPCB electrode plate disposed between the power pulleys, and a power interface and an SPI data interface provided at one end of the housing.

[0009] Preferably, the sub-probe contains a sub-microcontroller and a circuit board. The sub-microcontroller is an STM32 microcontroller minimum system board, and the circuit board is a PCAP02 capacitor-to-digital converter chip. The PCAP02 capacitor-to-digital converter chip converts capacitance changes into digital signals based on the DC charging and discharging method. The PCAP02 capacitor-to-digital converter chip transmits the data to the STM32 microcontroller minimum system board for processing via SPI communication.

[0010] Preferably, the FPCB electrode plate is a flexible coplanar capacitor seven-array detection electrode plate, which includes a rectangular ground electrode plate on the left and seven square detection electrodes on the right.

[0011] Preferably, the main control compartment includes a main control microcontroller, an SPI expansion board on top of the main control microcontroller, a motor drive board on the right side of the main control microcontroller, a power supply board below the main control microcontroller, and a lithium battery on the right side of the power supply board. The main control microcontroller is connected to the SPI expansion board via an SPI interface, connected to the motor drive board via a specific control circuit, connected to the power supply board via a power line, and connected to the lithium battery via wires.

[0012] Preferably, the carrier is a crab carrier, which includes a worm motor housing with an encoder. The crab carrier drives the main control housing and the capacitor array probe structure to move automatically in the pipeline. The encoder on the worm motor housing with the encoder can calculate the mileage after conversion.

[0013] Therefore, the present invention employs the above-mentioned non-destructive testing device for deep-sea mining pipe linings based on coplanar capacitance technology, and the technical effects are as follows:

[0014] 1. Solved the problem of non-destructive automated testing: Through coplanar capacitance technology, non-destructive automated testing of defects in the nylon lining of seabed mining pipes was achieved, overcoming the limitations of traditional testing methods in terms of automation and accuracy.

[0015] 2. High-precision defect detection: The device adopts a flexible coplanar capacitor seven-array detection plate design, which improves the sensitivity and resolution of the detection. The device can accurately identify minute defects in the inner nylon lining layer.

[0016] 3. Real-time data acquisition and analysis: The PCAP02 capacitor digital conversion chip inside the sub-probe converts capacitance changes into digital signals based on the DC charging and discharging method, and transmits them to the STM32 microcontroller for processing via SPI communication, realizing real-time data acquisition and analysis.

[0017] 4. Automated movement and mileage recording: The crab-type carrier drives the main control compartment and the capacitor array probe structure to move automatically inside the pipeline. The worm motor compartment with encoder can record the mileage of the probe, providing an accurate basis for the positioning and analysis of the detection data. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the non-destructive testing device for mining pipe lining of the present invention;

[0019] Figure 2 This is a schematic diagram of the cylindrical retractable capacitive array probe structure of the present invention;

[0020] Figure 3 This is a schematic diagram of the external structure of the single probe of the present invention;

[0021] Figure 4 This is a schematic diagram of the internal structure of the single probe of the present invention;

[0022] Figure 5 This is a schematic diagram of the internal structure of the main control compartment of the present invention;

[0023] Figure 6 This is a schematic diagram of the crab-type carrier structure of the present invention;

[0024] Figure 7 This is a schematic diagram of the actual flexible coplanar capacitor seven-array detection plate of the present invention;

[0025] Figure 8 This is a schematic diagram of the single-probe, single-channel test results according to an embodiment of the present invention;

[0026] Figure 9 This is a test cloud map of a 5mm diameter hole scanned by a single probe array according to an embodiment of the present invention;

[0027] Figure 10 This is a schematic diagram of the whole machine motion test according to an embodiment of the present invention;

[0028] Figure 11 The above is a cloud map of the host computer showing the defect results of the whole machine test in an embodiment of the present invention; (a) is a hole defect with a diameter of 5mm and a depth of 1mm; (b) is a groove defect with a length of 5mm, a width of 2mm and a depth of 1mm.

[0029] Figure Labels

[0030] 1. Capacitor array detection probe; 2. Main control compartment; 3. Universal connecting rod; 4. Mounting device; 5. Worm motor compartment with encoder; 6. Mounting disc; 7. Sub-probe; 8. Spring inner cylinder; 9. Top cover; 10. FPCB electrode plate; 11. Power pulley; 12. Housing; 13. Power interface; 14. SPI data interface; 15. Sub-microcontroller; 16. Circuit board; 17. SPI expansion board; 18. Main control microcontroller; 19. Power board; 20. Lithium battery; 21. Motor drive board. Detailed Implementation

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0032] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0033] Example 1

[0034] To adapt to the inner diameter The system is capable of inspecting the inner lining of subsea mining pipes with a thickness of 6mm and material PA12, and can detect defects as small as 5mm in diameter and 1mm in depth, as well as groove defects with a length of 5mm and a width of 2mm. Figure 1 As shown, this invention provides a non-destructive testing device for deep-sea mining pipe linings based on coplanar capacitance technology. The device includes a cylindrical retractable capacitance array detection probe 1, a main control chamber 2, and a mount 4. The mount 4 is connected to the main control chamber 2 via a universal connecting rod 3, and the main control chamber 2 is connected to the capacitance array detection probe 1 via the universal connecting rod 3. Through high-precision capacitance detection technology, real-time, non-destructive testing of deep-sea mining pipe linings is achieved, effectively identifying defects such as wear, corrosion, and cracks in the lining, providing strong assurance for the safety and efficiency of deep-sea mining operations.

[0035] like Figure 2As shown, the cylindrical telescopic capacitance array detection probe 1 includes a spring inner cylinder 8, a mounting disk 6, and sub-probes 7. The mounting disk 6 is connected to both ends of the spring inner cylinder 8 to ensure stable telescopic movement of the probe within the pipeline. Multiple sub-probes 7 are evenly distributed on the outer side of the spring inner cylinder 8, and each sub-probe 7 has a power pulley 11 and an FPCB electrode plate 10 on its outer surface. The power pulley 11 allows the probe to move smoothly within the pipeline, reducing friction. The FPCB electrode plate 10, as the core component of capacitance detection, reflects the defects in the lining by detecting changes in capacitance.

[0036] like Figures 3-4 As shown, the sub-probe 7 includes a housing 12, a top cover 9, a drive pulley 11, an FPCB electrode plate 10, a power interface 13, and an SPI data interface 14. The housing 12 is fixedly connected to the top cover 9 with screws. The drive pulley 11 is embedded on both ends of the top cover 9, and the FPCB electrode plate 10 is positioned between the drive pulleys 11 to ensure the accuracy and stability of the detection. The sub-probe 7 internally houses a sub-microcontroller 15 and a circuit board 16. The sub-microcontroller 15 is an STM32 microcontroller minimum system board, and the circuit board 16 is a PCAP02 capacitor-to-digital converter chip. The PCAP02 chip converts capacitance changes into digital signals based on a DC charging and discharging method and transmits them to the STM32 microcontroller for processing via SPI communication, enabling real-time data acquisition and analysis.

[0037] Among them, such as Figure 7 As shown, based on the principle of coplanar capacitance detection and the simulation analysis of the influence of capacitor plate parameters on defects, a flexible coplanar capacitance seven-array detection plate was designed for FPCB plate 10, including a rectangular ground plate on the left and seven square detection plates on the right. This design improves the sensitivity and resolution of detection and can accurately identify minute defects in the liner.

[0038] like Figure 5 As shown, the main control compartment 2 includes a main control microcontroller 18, an SPI expansion board 17, a motor drive board 21, a power supply board 19, and a lithium battery 20. The SPI expansion board 17 is located above the main control microcontroller 18, the motor drive board 21 is located on its right side, and the power supply board 19 is located below it. The lithium battery 20 is located on the right side of the power supply board 19. The main control microcontroller 18 connects to the SPI expansion board 17 via an SPI interface to achieve fast data transmission and processing; it connects to the motor drive board 21 via a specific control circuit to control the movement of the probe; and it connects to the power supply board 19 via a power line. The power supply board 19 is then connected to the lithium battery 20 via wires to provide stable power support for the entire device.

[0039] like Figure 6As shown, the carrier 4 is a crab-type carrier 4, including a worm gear motor housing 5 with an encoder. The crab-type carrier 4 drives the main control housing 2 and the capacitor array probe structure to move automatically within the pipeline, achieving comprehensive and efficient inspection. The encoder on the worm gear motor housing 5 can convert and record the probe's travel distance, providing accurate basis for the positioning and analysis of the inspection data.

[0040] The specific implementation process of the above-mentioned device is as follows:

[0041] According to the PCAP02 chip datasheet, the capacitance detection circuit board 16 was designed using EDA software, and the fabrication process was FR4. Then, based on the designed circuit board 16 dimensions and the inner diameter of the conduit... The technical specifications were determined as follows: 12 circumferential sub-probes 7, with an inner diameter of 192mm, a length of 110mm, and a width of 43mm in the non-extension state. Secondly, based on the chip's user manual and data transmission rate, the communication method between it and the STM32 controller was determined to be SPI. Based on the hardware connection requirements, appropriate wiring terminals were selected, ultimately determining that the housing 12 has a 3-pin power interface 13 and a 4-pin SPI communication interface.

[0042] Based on COMSOL simulation analysis of the influence of electrode parameters on defects, the electrode PCB was drawn using AD software, and the fabrication process was selected as FPCB. The design uses a flexible coplanar capacitor seven-array detection electrode plate, consisting of a rectangular ground electrode plate on the left (length × width: 41mm × 5mm), and seven square detection electrodes with a side length of 5mm on the right, arranged vertically with a 1mm spacing between each pair. The spacing between the ground electrode plate and the detection electrodes is 1mm.

[0043] To ensure the overall detection performance of the device, a nylon layer defect detection test was performed on a single probe beforehand. The test sample was a 6mm thick nylon block made of PA12 material. The block had circular holes with a depth of 1mm and diameters of 5mm, 10mm, and 15mm machined on its top. The single-probe, single-channel test results are as follows: Figure 8 As shown, the cloud map results of an array scan of a hole with a depth of 1 mm and a diameter of 5 mm are as follows. Figure 9 As shown.

[0044] After the single-probe capacitance test results are completed, the overall mechanical structure design of the capacitance detection device is completed using SolidWorks software, including the cylindrical telescopic capacitance array probe, the main control compartment 2, the universal connecting rod 3, and the crab-type carrier 4.

[0045] The various mechanical components are assembled, and then the overall machine motion test and the defect test of the inner nylon lining are performed. The overall machine motion test is as follows: Figure 10 As shown, the developed testing device is placed inside the pipeline, and a drive motor moves the device forward and backward.

[0046] like Figure 11 The above shows the host computer cloud map display of the defect results of the whole machine test. (a) It can be seen that when the device detects a hole defect with a diameter of 5mm and a depth of 1mm, the cloud map interface will change from blue when there is no defect to red when there is a defect, and the quantified defect shape is approximately circular. (b) It shows that when the device detects a groove defect with a length of 5mm, a width of 2mm and a depth of 1mm, the cloud map interface will change from blue when there is no defect to red when there is a defect, and the quantified defect shape is approximately groove-shaped.

[0047] The results show that the developed non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology can detect defects in the nylon lining layer. It can detect holes with a diameter of 5 mm and a depth of 1 mm, as well as grooves with a length of 5 mm and a width of 2 mm, with high detection accuracy.

[0048] Therefore, this invention employs the aforementioned non-destructive testing device for deep-sea mining pipe linings based on coplanar capacitance technology. By integrating the coplanar capacitance detection principle, the design of a cylindrical retractable capacitor array detection probe, a flexible coplanar capacitance seven-array detection plate, a PCAP02 capacitor digital conversion chip and an STM32 microcontroller real-time data processing system, a crab-type carrier and encoder for automated movement and mileage recording, as well as intuitive display and defect quantification technology using a host computer cloud map, this invention achieves high-precision, non-destructive, automated detection of defects in the nylon layer lining of seabed mining pipes. This significantly improves detection efficiency and accuracy, providing a solid guarantee for the safety and efficiency of deep-sea mining operations.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A non-destructive testing device for the lining of deep-sea mining pipes based on coplanar capacitance technology, characterized in that, The device includes a cylindrical retractable capacitor array detection probe, a main control compartment, and a mount. The mount is connected to the main control compartment via a universal connecting rod, and the main control compartment is connected to the capacitor array detection probe via a universal connecting rod. The cylindrical retractable capacitor array detection probe includes a spring inner cylinder, a mounting disk, and a sub-probe. The mounting disk is connected to both ends of the spring inner cylinder, and the sub-probe is connected to the outer side of the spring inner cylinder. The outer surface of the sub-probe is provided with a power pulley and an FPCB electrode plate.

2. The non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology according to claim 1, characterized in that, The sub-probe includes a housing with a top cover on top. The housing is fixedly connected to the top cover by screws. Power pulleys are embedded on both ends of the top cover. The FPCB electrode plate is placed between the power pulleys. One end of the housing has a power interface and an SPI data interface.

3. The non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology according to claim 1, characterized in that, The sub-probe contains a sub-microcontroller and a circuit board. The sub-microcontroller is an STM32 microcontroller minimum system board, and the circuit board is a PCAP02 capacitor-to-digital converter chip. The PCAP02 capacitor-to-digital converter chip converts capacitance changes into digital signals based on the DC charging and discharging method. The PCAP02 capacitor-to-digital converter chip transmits the data to the STM32 microcontroller minimum system board for processing via SPI communication.

4. The non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology according to claim 2, characterized in that, The FPCB electrode plate is a flexible coplanar capacitor seven-array detection electrode plate, which includes a rectangular ground electrode plate on the left and seven square detection electrodes on the right.

5. The non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology according to claim 1, characterized in that, The main control compartment contains a main control microcontroller, an SPI expansion board on top of the main control microcontroller, a motor drive board on the right side of the main control microcontroller, a power supply board below the main control microcontroller, and a lithium battery on the right side of the power supply board. The main control microcontroller is connected to the SPI expansion board via an SPI interface, to the motor drive board via a specific control circuit, and to the power supply board via a power line. The power supply board is connected to the lithium battery via wires.

6. The non-destructive testing device for deep-sea mining pipe lining based on coplanar capacitance technology according to claim 1, characterized in that, The carrier is a crab-type carrier, which includes a worm motor housing with an encoder. The crab-type carrier drives the main control housing and the capacitor array probe structure to move automatically in the pipeline. The encoder on the worm motor housing with the encoder can calculate the mileage after conversion.

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