Flaw detection system and method

Abstract

The invention relates to the technical field of industrial detection, in particular to a flaw detection system and method.The flaw detection system comprises a stepping module, a rotation detection module, a detection module, a cylindrical inner wall part, an integrated coding driver, an SD-OCT unit, an optical fiber, a signal transceiving and control unit and an image processing and display unit. According to the flaw detection system and method, the SD-OCT aplanatism point technology is utilized, the MEMS galvanometer is introduced, aplanatism points of the SD-OCT unit are controlled on the surface of the cylindrical inner wall, and when concave or convex flaws with the minimum precision being micron-level appear on the inner wall, the system automatically records defect position images. The system is not influenced by ambient light, and a flaw detection mode with high measurement precision and high automation degree is provided.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial inspection, and in particular, to a flaw detection system and method. Background Art

[0002] With the accelerating transformation of the global manufacturing industry towards high precision and intelligence, the processing quality of precision components has become the core indicator for measuring the performance of high-end equipment. Especially in the field of mechanical manufacturing and processing, cylindrical parts, as the key carriers of transmission structures (such as automotive engine accumulators, gear shaft sleeves, hydraulic piston rings, etc.), the geometric accuracy of their inner walls directly affects the sealing performance, wear resistance, and transmission efficiency of the power system. Taking the automotive industry as an example, for every 1-micron increase in the roundness error of an internal combustion engine piston ring, the fuel consumption rate may increase by 0.3% - 0.5%; if the inner wall roughness of the annular parts in a gearbox exceeds the standard, it may cause high-frequency vibration, resulting in a 15% - 20% reduction in the service life of the transmission system. Similarly, for cylindrical components such as high-pressure fuel pipelines in the aerospace field and micro-implant cannulas in the medical device field, the accuracy error of their inner walls is directly related to the safety and reliability of the equipment. These demands have driven the urgent need for micron-level detection technology in the precision manufacturing industry, but the limitations of existing detection methods have severely restricted the technological upgrading of the industry.

[0003] Currently, the quality inspection of cylindrical parts in the industry mainly relies on two types of methods, but their technical bottlenecks are becoming increasingly prominent:

[0004] I. Analysis of the Limitations of Traditional Detection Techniques

[0005] 1. Manual measurement method: 1) The operator uses contact tools such as calipers, plug gauges, and pneumatic gauges for manual measurement. This method still dominates in small and medium-sized enterprises, but its defects are significant: Uncontrollable human error: Problems such as measurement angle deviation and uneven contact pressure can result in a difference of 2 - 5 microns in repeated measurements, while the tolerance band of precision parts usually requires control within ±3 microns; 2) Insufficient equipment accuracy: The resolution of mechanical measuring tools (such as vernier calipers) is generally 10 - 50 microns, which cannot meet the detection requirements of ultra-precision machined parts; 3) Efficiency and cost issues: Manual inspection of a single piece takes up to 10 - 15 minutes, and the measuring tools need to be calibrated frequently.

[0006] 2. Large-scale automated inspection equipment: High-end equipment represented by coordinate measuring machines (CMMs) and laser scanners can achieve non-contact measurement, but their application limitations are prominent: 1) Poor spatial adaptability: The floor area of CMM equipment usually exceeds 5 square meters, requiring an independent inspection station and being difficult to integrate into a compact production line; 2) Contradiction between inspection accuracy and curvature adaptability: In the measurement of the inner wall with high curvature (deep holes with a diameter < 30 mm) by the traditional laser triangulation method, edge distortion of 10 - 20 microns is generated due to beam scattering; 3) Economic barriers: The procurement cost of imported coordinate measuring machines exceeds 1.5 million yuan, and the annual maintenance cost accounts for 25% - 30%. It is difficult for small and medium-sized enterprises to bear, resulting in a technology penetration rate of less than 20%. In addition, such equipment has strict requirements for the positioning fixtures of workpieces, and the changeover and debugging take up to 2 - 4 hours, severely restricting the multi-variety and small-batch production mode.

[0007] II. Special technical challenges in the inspection of cylindrical parts

[0008] The geometric features of cylindrical parts and the complexity of industrial scenarios further exacerbate the inspection difficulty: 1) Barrier to inner wall accessibility: Tubular structures with a depth-to-diameter ratio > 10:1 (such as hydraulic valve bodies and fuel injection pipes) are difficult to achieve full circumferential coverage inspection. The bending radius of the existing equipment probe is limited, resulting in a blind area ratio of more than 30%; 2) Multi-parameter coupling: Parameters such as inner diameter, roundness, cylindricity, and surface roughness need to be measured synchronously, while traditional equipment mostly adopts a step-by-step inspection mode.

[0009] However, the current mainstream equipment in the market does not fully meet the above requirements. The manual inspection method is restricted by the ceiling of accuracy and efficiency, while large-scale equipment is difficult to popularize due to cost and adaptability issues. In order to achieve high-precision automated inspection of parts with cylindrical inner walls, the present invention provides an OCT-based cylindrical inner wall flaw detection system and method, which can achieve micron-level and highly automated inner wall trace detection. Summary of the Invention

[0010] The embodiments of the present invention provide a flaw detection system and method to solve the technical problems of low measurement accuracy and low automation degree of the existing flaw detection system.

[0011] According to an embodiment of the present invention, a flaw detection system is provided, including: a stepping module, a rotation detection module, a detection module, a cylindrical inner wall part, an integrated encoder driver, an SD-OCT unit, an optical fiber, a signal transceiver and control unit, and an image processing and display unit; wherein:

[0012] Input the detection requirement signal into the signal transceiver and control unit. At this time, the signal transceiver and control unit sends corresponding rotation parameters to the first servo motor of the stepping module and the second servo motor of the detection module according to the detection requirement signal, and sends an imaging instruction to the SD-OCT unit;

[0013] After receiving the imaging instruction, the SD-OCT unit controls the light source to emit laser light. The laser light reaches the lens of the detection module through an optical fiber and is incident on the inner surface of the cylindrical inner wall part in the form of free-space light propagation, where it reflects and scatters with the scratches on the inner wall of the inner wall part. Part of the light returns to the SD-OCT unit along the original path.

[0014] When the laser light is incident on the inner surface of the inner wall part, the signal transceiver and control unit sends an electrical signal to the integrated coding driver according to the input detection requirement signal, controlling the first servo motor and the second servo motor to rotate. While the first servo motor moves back and forth, the second servo motor rotates synchronously to perform an overall scan of the inner wall of the inner wall part.

[0015] The signal transceiver and control unit integrates the electrical signals collected by the SD-OCT unit and the digital signals corresponding to the input detection requirement signals, and then uniformly converts them into digital signals and sends them to the image processing and display unit. The image processing and display unit processes the digital signals and displays the relevant information about the scratches inside the inner wall part.

[0016] Further, the stepping module consists of a first servo motor, a single-axis driver, an optoelectronic limit switch, and a baffle.

[0017] The first servo motor is electrically connected to the integrated coding driver and rotates according to the drive of the integrated coding driver.

[0018] The single-axis driver is a slider guide rail, including a motor fixing seat, a U-shaped groove, a lead screw, a slider, and a tailstock. The first servo motor is installed at the motor fixing seat, and the motor fixing seat is connected to the U-shaped groove and the lead screw. The first servo motor converts the rotational motion into a reciprocating motion through the lead screw; the U-shaped groove is connected to the motor fixing seat and the tailstock, and is used to clamp both sides of the slider, enabling the slider to perform a parallel reciprocating motion in the direction indicated by the lead screw; the lead screw provides a path for the linear reciprocating motion of the slider; the slider is clamped on both sides by the U-shaped groove, enabling the slider to perform a parallel reciprocating motion; the tailstock is connected to the lead screw and the U-shaped groove to fix one end of the lead screw.

[0019] The optoelectronic limit switch is connected to one side of the U-shaped groove and is electrically connected to the integrated coding driver.

[0020] The baffle is connected to one side of the slider and on the same side as the optoelectronic limit switch; the optoelectronic limit switch uses both sides of the U-shaped groove as the transmitting and receiving ends of the optical signal. When the optical signal is blocked by the baffle, the optoelectronic limit switch sends an electrical signal to the integrated coding driver, and then the integrated coding driver sends a stop rotation signal to the first servo motor to achieve the limiting function.

[0021] Further, the rotation detection module includes a probe, a MEMS galvanometer, a bearing seat fixing part, bearings, a bearing seat, a clamping ring, a conductive slip ring, and a transmission wheel;

[0022] The probe is coaxially installed in the order of bearings, bearing seat, bearings, clamping ring, conductive slip ring, and transmission wheel. Among them, the bearing seat is coaxially installed with the cylindrical notch of the bearing seat fixing part, and the clamping ring, conductive slip ring, and transmission wheel are all connected and locked from one side;

[0023] The MEMS galvanometer is electrically connected to the conductive slip ring and the SD-OCT unit. The MEMS galvanometer is powered by the power supply through the conductive slip ring and is controlled by the SD-OCT unit. The MEMS galvanometer will perform swing scanning under the control of the SD-OCT unit to realize the acquisition of one-dimensional data. At this time, combined with the rotation of the probe and the reciprocating movement of the slider, the inner wall surface of the cylindrical inner wall part is scanned;

[0024] The bearing seat fixing part is connected to the slider and the bearing seat, and the reciprocating movement of the rotation detection module is realized through this connection; The bearings are installed at both ends of the bearing seat, and the probe, bearings, bearing seat, and bearings are pressed tightly by the clamping ring; The bearing seat is connected to the bearing seat fixing part; The clamping ring is connected to the probe to fix the positions of the probe, bearings, bearing seat, and bearings;

[0025] The conductive slip ring is electrically connected to the power supply and the SD-OCT unit, and is adjacent to the clamping ring in terms of spatial position. The power supply supplies power to the MEMS galvanometer through the conductive slip ring, and the SD-OCT unit controls the MEMS galvanometer to receive the collected signals through the conductive slip ring;

[0026] The transmission wheel is connected to the probe, fixes the conductive slip ring, and is connected to the synchronous belt keyway. The rotation of the second servo motor drives the transmission wheel, and the probe is driven to rotate through the synchronous belt and the transmission wheel.

[0027] Further, the detection module includes a transmission base, a second servo motor, a transmission wheel, a synchronous belt, a lens fixing part, and a lens;

[0028] The detection module is bolt-connected to the slider and coincides with the central axes of the probe and the cylindrical inner wall part;

[0029] The transmission base is connected to the rotation detection module, the second servo motor, and the slider, and synchronously performs reciprocating movement of the detection module installed on the slider and the slider;

[0030] The second servo motor is electrically connected to the integrated encoder driver and rotates according to the drive of the integrated encoder driver. The second servo motor is connected to the transmission base, and the installation of the second servo motor makes the transmission wheel of the rotation detection module and the transmission wheel of the detection module in a flush position;

[0031] The driving wheel of the detection module is connected to the second servo motor. The driving wheel of the rotation detection module and the driving wheel of the detection module are connected through a synchronous belt keyway. The three work together to synchronize the rotational motion of the second servo motor to the probe of the rotation detection module. The synchronous belt is connected to the driving wheels of the rotation detection module and the detection module through keyways, driving the probe to rotate.

[0032] The lens fixing part is connected to the transmission base, making the central axis of the lens coincide with the central axis of the probe.

[0033] The lens is connected to the lens holder and is connected to the SD-OCT unit through an optical fiber. The outgoing light of the SD-OCT unit is incident parallel to the MEMS galvanometer through the characteristics of free space propagation of light. The outgoing light is reflected by the MEMS galvanometer to the surface of the cylindrical inner wall part through the way of free space propagation of light, and then returns to the MEMS galvanometer, lens, optical fiber, and SD-OCT unit along the original path in turn. And the optical axis of the outgoing light coincides with the central axes of the lens and the probe.

[0034] Furthermore, the installation fixture is bolted to the tailstock and is connected and cooperated with the cylindrical inner wall part. The central axis of the cylindrical inner wall part installed on the installation fixture coincides with the central axis of the probe.

[0035] Furthermore, the integrated encoder driver is electrically connected to the photoelectric limit switch, the first servo motor, the second servo motor, the power supply, and the signal transceiver and control unit. It supplies the direct current of the power supply to the photoelectric limit switch, the first servo motor, and the second servo motor, controls the rotation of the first servo motor and the second servo motor according to the control instructions issued by the signal transceiver and control unit, receives the electrical signal of the photoelectric limit switch, judges whether the first servo motor reaches the limit, and if it reaches the limit, it will send an instruction to the signal transceiver and control unit. The signal transceiver and control unit stops the rotation of the first servo motor according to the feedback adjustment.

[0036] Furthermore, the SD-OCT unit acquires the image information within the depth range of the preset detection plane by controlling the light output of the light source and the cooperation scanning of the MEMS galvanometer. The SD-OCT unit is electrically connected to the power supply, the MEMS galvanometer, and the signal transceiver and control unit and is controlled by the signal transceiver and control unit.

[0037] Further, the signal transceiver and control unit is electrically connected to the integrated coding driver and the SD-OCT unit, sends an electrical signal to the integrated coding driver to control the rotation parameters of the first servo motor and the second servo motor, and sends the rotation parameters and the digital signal collected by the SD-OCT unit to the image processing and display unit, receives the signal returned by the photoelectric limit switch via the integrated coding driver, determines whether the first servo motor reaches the limit. If the first servo motor reaches the limit at this time, the signal transceiver and control unit will send an electrical signal to the integrated coding driver and control the first servo motor to stop moving.

[0038] Further, the image processing and display unit is electrically connected to the signal transceiver and control unit, reconstructs the three-dimensional inner surface image of the cylindrical inner wall part according to the rotation parameters sent by the signal transceiver and control unit and the digital signal collected by the SD-OCT unit, obtains the scratch information inside the cylindrical inner wall part, calculates the depth, width, and position information of the scratch according to this information, and stores it locally in the form of tables and pictures.

[0039] According to another embodiment of the present invention, a flaw detection method is provided, including the following steps:

[0040] Input the detection requirement signal into the signal transceiver and control unit. At this time, the signal transceiver and control unit sends the corresponding rotation parameters to the first servo motor of the stepping module and the second servo motor of the detection module according to the detection requirement signal, and sends an imaging instruction to the SD-OCT unit;

[0041] After receiving the imaging instruction, the SD-OCT unit controls the light source to emit laser light. The laser light reaches the lens of the detection module through the optical fiber and is incident on the inner surface of the cylindrical inner wall part in the form of free-space light propagation, reflects and scatters with the scratches on the inner wall of the inner wall part, and part of the light returns to the SD-OCT unit along the original path;

[0042] When the laser light is incident on the inner surface of the inner wall part, the signal transceiver and control unit sends an electrical signal to the integrated coding driver according to the input detection requirement signal, controls the first servo motor and the second servo motor to rotate. While the first servo motor moves back and forth, the second servo motor rotates synchronously to perform an overall scan of the inner wall of the inner wall part;

[0043] The signal transceiver and control unit integrates the electrical signal collected by the SD-OCT unit and the digital signal corresponding to the input detection requirement signal, uniformly converts them into digital signals and sends them to the image processing and display unit. The image processing and display unit processes the digital signals and displays the relevant information of the scratches inside the inner wall part.

[0044] A storage medium stores a program file capable of implementing any of the above flaw detection methods.

[0045] A processor is used to run a program. When the program runs, the flaw detection method of any one of the above is executed.

[0046] In the flaw detection system and method of the embodiments of the present invention, by using optical path point technologies such as SD-OCT and introducing a MEMS galvanometer, the equal optical path points of the SD-OCT unit are controlled on the surface of the cylindrical inner wall. When there are scars with a minimum precision of micron-level depressions or protrusions on the inner wall, the system automatically records the defect position image. This system is not affected by ambient light and provides a flaw detection method with high measurement accuracy and high automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0048] Figure 1a ) is the front view of the stepping module in the present invention;

[0049] Figure 1b ) is the schematic diagram of the photoelectric limit switch and the baffle in the present invention;

[0050] Figure 2a ) is the front view of the rotation detection module in the present invention;

[0051] Figure 2b ) is the side view of the rotation detection module in the present invention;

[0052] Figure 2c ) is the rotation detection module in the present invention Figure 2a ) of the A-A cross-sectional view;

[0053] Figure 3a ) is the front view of the detection module in the present invention;

[0054] Figure 3b ) is the detection module in the present invention Figure 3a ) of the A-A cross-sectional view.

[0055] Explanation of the reference numerals in the drawings:

[0056] 1 - Stepping module, 101 - First servo motor, 102 - Single-axis driver, 1021 - Motor fixing base, 1022 - U-shaped groove, 1023 - Lead screw, 1024 - Slide block, 1025 - Tailstock, 103 - Photoelectric limit switch, 104 - Baffle, 2 - Rotation detection module, 201 - Probe, 202 - MEMS galvanometer, 203 - Bearing seat fixing part, 204 - Bearing, 205 - Bearing seat, 206 - Clamping ring, 207 - Conductive slip ring, 208 - Transmission wheel, 3 - Detection module, 301 - Transmission base, 302 - Second servo motor, 303 - Transmission wheel, 304 - Timing belt, 305 - Lens fixing part, 306 - Lens, 4 - Mounting fixture, 5 - Cylindrical inner wall part, 6 - Power supply, 7 - Integrated encoder driver, 8 - SD-OCT unit, 9 - Optical fiber, 10 - Signal transceiver and control unit, 11 - Image processing and display unit. Detailed implementation mode

[0057] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0059] The present invention utilizes optical path point technologies such as SD-OCT and introduces a MEMS galvanometer to control the equal optical path points of the SD-OCT unit on the surface of the cylindrical inner wall. When there are scars with a minimum precision of micron-level depressions or protrusions on the inner wall, the system automatically records the defect position image. This system is not affected by ambient light and provides a flaw detection system and method with high measurement accuracy and high automation.

[0060] A flaw detection system includes: a stepping module 1, a rotation detection module 2, a detection module 3, a mounting fixture 4, a cylindrical inner wall part 5, a power supply 6, an integrated encoder driver 7, an SD-OCT unit 8, an optical fiber 9, a signal transceiver and control unit 10, and an image processing and display unit 11.

[0061] See Figure 1a ), the stepping module 1 is composed of a first servo motor 101, a single-axis driver 102, an optoelectronic limit switch 103, and a baffle 104, and its function is to achieve precise movement of the slider 1024.

[0062] The first servo motor 101 is an integrated closed-loop stepping servo motor, which is electrically connected to the integrated encoder driver 7 and rotates according to the drive of the integrated encoder driver 7.

[0063] The single-axis driver 102 is a slider guide rail, including a motor fixing seat 1021, a U-shaped groove 1022, a lead screw 1023, a slider 1024, and a tailstock 1025. The first servo motor 101 is installed at the motor fixing seat 1021. The motor fixing seat 1021 is bolted to the U-shaped groove 1022 and the lead screw 1023. The first servo motor 101 converts the rotational motion into a reciprocating motion by means of a coupling connection through the lead screw 202; the U-shaped groove 1022 is bolted to the motor fixing seat 1021 and the tailstock 1025, and is used to clamp both sides of the slider 1024, so that the slider 1024 makes a parallel reciprocating motion along the direction pointed by the lead screw 1023; the lead screw 1023 provides a path for the linear reciprocating motion of the slider 1024; the slider 1024 is installed by means of a threaded fit between the internal internal thread and the external thread of the lead screw 1023, and is clamped by the U-shaped groove 1022 on both sides of the slider 1024, so that the slider 1024 makes a parallel reciprocating motion; the tailstock 1025 is bolted to the lead screw 1023 and the U-shaped groove 1022 to fix one end of the lead screw 1023.

[0064] See Figure 1b ), the optoelectronic limit switch 103 is a pair of U-groove optoelectronic switches, which are bolted to one side 202 of the U-shaped groove and are electrically connected to the integrated encoder driver 7.

[0065] The baffle 104 is bolted to one side of the slider 1024 and on the same side as the optoelectronic limit switch 103, and forms a limit system with the optoelectronic limit switch 103. The optoelectronic limit switch 103 is U-shaped, and the two sides of the U-shape are used as the light signal emission and reception ends. When the light signal is blocked by the baffle 104, the optoelectronic limit switch 103 sends an electrical signal to the integrated encoder driver 7, and then the integrated encoder driver 7 sends a stop rotation signal to the first servo motor 101 to achieve the limit function.

[0066] Among them, the limit system composed of the photoelectric limit switch 103 and the baffle 104 installed on the slider 1024 restricts the range of the linear reciprocating motion of the slider 1024, avoiding the situation where due to failures in the braking system or the coding system between the single-axis driver 102 and the integrated coding driver 7, the slider 1024 moves beyond the input value and exceeds the motion range, and can prevent the probe 201 from hitting the bottom end of the cylindrical inner wall part 5, resulting in deformation of the probe 201.

[0067] See Figure 2a )、 Figure 2b )、 Figure 2c ) The rotation detection module 2 includes a probe 201, a MEMS galvanometer 202, a bearing seat fixing part 203, bearings 204, a bearing seat 205, a clamping ring 206, a conductive slip ring 207, and a transmission wheel 208. The probe 201 is a cylindrical probe with a coaxial cylindrical boss in the middle for fitting with the bearing 204. The probe 201 is coaxially installed in the order of the bearing 204, the bearing seat 205, the bearing 204, the clamping ring 206, the conductive slip ring 207, and the transmission wheel 208. Among them, the bearing seat 205 is coaxially installed with the cylindrical notch of the bearing seat fixing part 203, and the clamping ring 206, the conductive slip ring 207, and the transmission wheel 208 are all locked by set screws from one side through screw connections.

[0068] Among them, the diameter of the probe 201 is larger than the diameter of the space required for installing the MEMS galvanometer 202 and smaller than the inner diameter of the cylindrical inner wall part 5.

[0069] Among them, the MEMS galvanometer 202 is a one-dimensional MEMS galvanometer module. The MEMS galvanometer 202 is fixed to the probe 201 through the notch of the probe 201 by bolt connection and is electrically connected to the conductive slip ring 207 and the SD-OCT unit 8. The MEMS galvanometer 202 is powered by the power supply 6 through the conductive slip ring 207 and is controlled by the SD-OCT unit 8. The MEMS galvanometer 202 will perform swing scanning under the control of the SD-OCT unit 8 to realize the acquisition of one-dimensional data. At this time, combined with the rotation of the probe 201 and the reciprocating motion of the slider 1024, the inner wall surface of the cylindrical inner wall part 5 is scanned.

[0070] Among them, the bearing seat fixing part 203 is bolted to the slider 1024 and the bearing seat 205, and the reciprocating motion of the rotation detection module 2 is realized through this connection.

[0071] Among them, the bearings 204 are installed at both ends of the bearing seat 205, and the probe 201, the bearings 204, the bearing seat 205, and the bearings 204 are pressed tightly by the clamping ring 206 to fix the probe 201 and the bearing seat 205, enabling the probe 201 to rotate around the central axis of the bearing 204.

[0072] Among them, the bearing seat 205 is bolted to the bearing seat fixing part 203, providing a coaxial mounting structure for the bearing 204.

[0073] Among them, the clamping ring 206 is a metal ring with pin holes, and is screw-connected to the probe 201 through set screws to fix the positions of the probe 201, the bearing 204, the bearing seat 205, and the bearing 204, preventing the four components from sliding back and forth centered on the bearing seat, and enabling the probe 201 to rotate under the action of the bearing 204.

[0074] Among them, the conductive slip ring 207 is electrically connected to the power supply 6 and the SD-OCT unit 8, and is adjacent to the clamping ring 206 in the spatial position. The power supply 6 supplies power to the MEMS galvanometer 202 through the conductive slip ring 207, and the SD-OCT unit 8 controls the MEMS galvanometer 202 to receive the collected signals through the conductive slip ring 207.

[0075] Among them, the transmission wheel 208 is a ring with pin holes, and is screw-connected to the probe 201 through set screws to fix the conductive slip ring 207, and is keyway-connected to the synchronous belt 304. The rotation of the second servo motor 302 drives the transmission wheel 303, and drives the probe 201 to rotate through the synchronous belt 304 and the transmission wheel 208.

[0076] See Figure 3a )、 Figure 3b ), the detection module 3 includes a transmission base 301, a second servo motor 302, a transmission wheel 303, a synchronous belt 304, a lens fixing part 305 and a lens 306. The detection module 3 is bolted to the slider 1024 and coincides with the central axes of the probe 201 and the cylindrical inner wall part 5.

[0077] Among them, the transmission base 301 is bolted to the rotation detection module 2, the second servo motor 302 and the slider 1024, and its function is to move the detection module 3 installed on the slider 1024 and the slider 1024 back and forth synchronously.

[0078] Among them, the position where the rotation detection module 2 is installed on the transmission base 301 needs to satisfy that the central axis of the probe 201 of the rotation detection module 2 is parallel to the lead screw 1023.

[0079] Among them, the second servo motor 302 is an integrated closed-loop stepping servo motor, which is electrically connected to the integrated encoder driver 7 and rotates according to the drive of the integrated encoder driver 7. The second servo motor 302 is fixed to the transmission base 301 by bolt connection. The transmission wheel 303 on the rotating shaft of the second servo motor 302 is screw-connected through set screws, and the installation of the second servo motor 302 makes the transmission wheel 303 and the transmission wheel 208 in a flush position.

[0080] Among them, the transmission wheel 303 is a ring with pin holes, which is screw - connected to the second servo motor 302 through set screws. The transmission wheel 303, the transmission wheel 208 and the synchronous belt 304 are key - groove connected, and the three work together to synchronize the rotational motion of the second servo motor 302 to the probe 201 of the rotation detection module 2.

[0081] Among them, the synchronous belt 304 is key - groove connected to the transmission wheel 208 and the transmission wheel 303, driving the probe 201 to rotate.

[0082] Among them, the lens fixing part 305 is thread - connected to the transmission base 301, so that the central axis of the lens 306 coincides with the central axis of the probe 201.

[0083] Among them, the lens 306 is screw - connected to the lens fixing seat 305 and fiber - optically connected to the SD - OCT unit 8 through the optical fiber 9. The outgoing light of the SD - OCT unit 8 is parallel - incident on the MEMS galvanometer 202 through the characteristic of free - space light propagation. The outgoing light is reflected by the MEMS galvanometer 202 to the surface of the cylindrical inner - wall part 5 through the way of free - space light propagation, and returns to the MEMS galvanometer 202, the lens 306, the optical fiber 9, and the SD - OCT unit 8 along the original path in turn. And the optical axis of the outgoing light coincides with the central axes of the lens 306 and the probe 201.

[0084] The installation fixture 4 is a ring with internal threads, which is bolt - connected to the tailstock 1025 and thread - connected to the external thread of the cylindrical inner - wall part 5. The central axis of the cylindrical inner - wall part 5 installed on the installation fixture 4 coincides with the central axis of the probe 201.

[0085] Among them, the installation fixture 4 can be replaced according to different models of accumulators, so that the central axis of the cylindrical inner - wall part 5 coincides with the central axis of the probe 201. The diameter difference between the installation fixture 4 and the cylindrical inner - wall part 5 is ≤1 mm, and the actual error tolerance range is related to the imaging depth of the SD - OCT unit.

[0086] The cylindrical inner - wall part 5 includes but is not limited to parts such as automotive accumulators, automotive valve sleeves, and hydraulic piston rings.

[0087] The power supply 6 is a 220V AC - to - DC power supply, and its function is to supply power to the conductive slip ring 207, the SD - OCT unit 8, and the integrated encoder driver 7 through electrical connection.

[0088] The integrated coding driver 7 is electrically connected to the photoelectric limit switch 103, the first servo motor 101, the second servo motor 302, the power supply 6, and the signal transceiver and control unit 10. It supplies the direct current of the power supply 6 to the photoelectric limit switch 103, the first servo motor 101, and the second servo motor 302, controls the rotation of the first servo motor 101 and the second servo motor 302 according to the control instructions issued by the signal transceiver and control unit 10, receives the electrical signals of the photoelectric limit switch 103, judges whether the first servo motor 101 reaches the limit, and if it reaches the limit, it will send an instruction to the signal transceiver and control unit 10. The signal transceiver and control unit 10 stops the rotation of the first servo motor 101 according to the feedback adjustment.

[0089] The SD-OCT unit 8 is a Michelson interferometer system with a broadband light source with a central wavelength of 850 nm as the system light source. It acquires the image information within the depth range of the preset detection plane by controlling the light output of the light source and the cooperative scanning of the MEMS galvanometer 202. The SD-OCT unit 8 is electrically connected to the power supply 6, the MEMS galvanometer 202, and the signal transceiver and control unit 10, and is controlled by the signal transceiver and control unit 10.

[0090] The optical fiber 9 is an optical fiber with strong light transmittance in the 850 nm range, and can be selected as HI 780 optical fiber, which is used to connect the lens 306 and the SD-OCT unit 8 and serves as a channel for low-loss light propagation.

[0091] The signal transceiver and control unit 10 is electrically connected to the integrated coding driver 7 and the SD-OCT unit 8. It sends electrical signals to the integrated coding driver 7 to control the rotation parameters of the first servo motor 101 and the second servo motor 302, and sends the rotation parameters and the digital signals collected by the SD-OCT unit to the image processing and display unit 11. It receives the signals returned by the photoelectric limit switch 103 via the integrated coding driver 7, judges whether the first servo motor 101 reaches the limit. If the first servo motor 101 reaches the limit at this time, the signal transceiver and control unit will send an electrical signal to the integrated coding driver 7 and control the first servo motor 101 to stop moving.

[0092] The image processing and display unit 11 is electrically connected to the signal transceiver and control unit 10. It reconstructs the three-dimensional image of the inner surface of the cylindrical inner wall part 5 according to the rotation parameters sent by the signal transceiver and control unit 10 and the digital signals collected by the SD-OCT unit, so as to obtain the scratch information inside the cylindrical inner wall part 5, and calculates the depth, width, position and other information of the scratch according to this information, and stores it locally in the form of tables and pictures.

[0093] The present invention also provides a flaw detection method, and the steps are as follows:

[0094] 1. Input according to the detection requirements into the signal transceiver and control unit 10. At this time, the signal transceiver and control unit 10 sends corresponding rotation parameters to the first servo motor 101 and the second servo motor 302 according to the input, and sends an imaging instruction to the SD-OCT unit 8;

[0095] 2. After receiving the signal, the SD-OCT unit 8 controls the light source to emit laser light. The laser light passes through the optical fiber 9 to reach the lens 306 and then propagates in free space light mode through the lens fixing part 305 and the MEMS galvanometer 202 in sequence and is incident on the inner surface of the cylindrical inner wall part 5, where it reflects and scatters with the scratches on the inner wall. Part of the light returns to the SD-OCT unit 8 along the original path;

[0096] 3. While the laser light is incident on the inner surface of the cylindrical inner wall part 5 after passing through the MEMS galvanometer 202, the signal transceiver and control unit 10 sends an electrical signal to the integrated encoder driver 7 according to the input detection requirements to control the rotation of the first servo motor 101 and the second servo motor 302. While the first servo motor 101 controls the reciprocating motion of the slider 1024, the second servo motor 302 drives the probe 201 to rotate through the transmission wheel 303, the synchronous belt 304, and the transmission wheel 208, so as to realize the overall scanning of the inner wall of the cylindrical inner wall part 5;

[0097] 4. The signal transceiver and control unit 10 integrates the electrical signals collected by the SD-OCT unit 8 and the digital signals corresponding to the input detection requirements and uniformly converts them into digital signals and sends them to the image processing and display unit 11. The image processing and display unit 11 receives the digital signals, processes the digital signals, and displays the relevant information of the scratches inside the cylindrical inner wall part 5.

[0098] A storage medium stores a program file capable of implementing any one of the above flaw detection methods.

[0099] A processor is used to run a program. When the program runs, it executes any one of the above flaw detection methods.

[0100] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments.

[0101] In the above embodiments of the present invention, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] In several embodiments provided by the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are merely illustrative. For example, the division of units can be a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the couplings or direct couplings or communication connections shown or discussed with each other can be through some interfaces. The indirect couplings or communication connections of units or modules can be in electrical or other forms.

[0103] The units described as separate components may or may not be physically separated. The components shown as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0104] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0105] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the methods in each embodiment of the present invention. The foregoing storage medium includes: USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks or optical discs and other various media that can store program codes.

[0106] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A flaw detection system, characterized in that, Comprising: A stepping module, a rotation detection module, a detection module, a cylindrical inner wall part, an integrated coding driver, an SD-OCT unit, an optical fiber, a signal transceiver and control unit, and an image processing and display unit; wherein: Input the detection requirement signal into the signal transceiver and control unit. At this time, the signal transceiver and control unit sends corresponding rotation parameters to the first servo motor of the stepping module and the second servo motor of the detection module according to the detection requirement signal, and sends an imaging instruction to the SD-OCT unit; After receiving the imaging instruction, the SD-OCT unit controls the light source to emit laser light. The laser light reaches the lens of the detection module through the optical fiber and is incident on the inner surface of the cylindrical inner wall part in a free space light propagation mode, reflects and scatters with the scratches on the inner wall of the inner wall part, and part of the light returns to the SD-OCT unit along the original path; When the laser light is incident on the inner surface of the inner wall part, the signal transceiver and control unit sends an electrical signal to the integrated coding driver according to the input detection requirement signal, controls the first servo motor and the second servo motor to rotate. While the first servo motor moves back and forth, the second servo motor synchronously rotates to perform an overall scan of the inner wall of the inner wall part; The signal transceiver and control unit integrates the electrical signal collected by the SD-OCT unit and the digital signal corresponding to the input detection requirement signal, uniformly converts them into digital signals and sends them to the image processing and display unit. The image processing and display unit processes the digital signals and displays the relevant information of the scratches inside the inner wall part.

2. The flaw detection system according to claim 1, characterized in that The stepping module consists of a first servo motor, a single-axis driver, an optoelectronic limit switch, and a baffle; The first servo motor is electrically connected to the integrated coding driver and rotates according to the drive of the integrated coding driver; The single-axis driver is a slide rail, including a motor fixing seat, a U-shaped groove, a lead screw, a slider, and a tailstock. Install the first servo motor at the motor fixing seat. The motor fixing seat is connected to the U-shaped groove and the lead screw. The first servo motor converts the rotational motion into a reciprocating motion through the lead screw; the U-shaped groove is connected to the motor fixing seat and the tailstock, and is used to clamp both sides of the slider, so that the slider performs a parallel reciprocating motion in the direction indicated by the lead screw; the lead screw provides a path for the linear reciprocating motion of the slider; the slider clamps both sides of the slider through the U-shaped groove, so that the slider performs a parallel reciprocating motion; the tailstock is connected to the lead screw and the U-shaped groove to fix one end of the lead screw; The optoelectronic limit switch is connected to one side of the U-shaped groove and is electrically connected to the integrated coding driver; The baffle is connected to one side of the slider and on the same side as the optoelectronic limit switch; the optoelectronic limit switch uses both sides of the U-shaped groove as the light signal emission and reception ends. When the light signal is blocked by the baffle, the optoelectronic limit switch sends an electrical signal to the integrated coding driver, and then the integrated coding driver sends a stop rotation signal to the first servo motor to achieve the limiting function.

3. The flaw detection system according to claim 1, wherein The rotation detection module includes a probe, a MEMS galvanometer, a bearing seat fixing part, a bearing, a bearing seat, a clamping ring, a conductive slip ring, and a transmission wheel; The probe is coaxially installed in the order of bearing, bearing housing, bearing, clamping ring, conductive slip ring and transmission wheel. Among them, the bearing housing is coaxially installed with the cylindrical notch of the bearing housing fixture, and the clamping ring, conductive slip ring and transmission wheel are all connected and locked from one side. The MEMS galvanometer is electrically connected to the conductive slip ring and the SD-OCT unit. The MEMS galvanometer is powered by the power supply through the conductive slip ring and is controlled by the SD-OCT unit. When the MEMS galvanometer receives the control of the SD-OCT unit, it will swing and scan to realize the acquisition of one-dimensional data. At this time, combined with the rotation of the probe and the reciprocating movement of the slider, the inner wall surface of the cylindrical inner wall part is scanned. The bearing housing fixture is connected to the slider and the bearing housing, and the reciprocating movement of the rotation detection module is realized through this connection; the bearings are installed at both ends of the bearing housing, and the probe, bearing, bearing housing and bearing are pressed tightly by the clamping ring; the bearing housing is connected to the bearing housing fixture; the clamping ring is connected to the probe to fix the positions of the probe, bearing, bearing housing and bearing. The conductive slip ring is electrically connected to the power supply and the SD-OCT unit, and is adjacent to the clamping ring in terms of spatial position. The power supply supplies power to the MEMS galvanometer through the conductive slip ring, and the SD-OCT unit controls the MEMS galvanometer to receive the collected signal through the conductive slip ring. The transmission wheel is connected to the probe, fixes the conductive slip ring, and is connected to the synchronous belt keyway. The transmission wheel is driven by the second servo motor to drive the probe to rotate through the synchronous belt and the transmission wheel.

4. The flaw detection system according to claim 1, characterized in that, The detection module includes a transmission base, a second servo motor, a transmission wheel, a synchronous belt, a lens fixture and a lens. The detection module is bolted to the slider and coincides with the central axes of the probe and the cylindrical inner wall part. The transmission base is connected to the rotation detection module, the second servo motor and the slider, and synchronizes the detection module installed on the slider and the slider to move back and forth. The second servo motor is electrically connected to the integrated encoder driver and rotates according to the drive of the integrated encoder driver. The second servo motor is connected to the transmission base, and the installation of the second servo motor makes the transmission wheel of the rotation detection module and the transmission wheel of the detection module in a flush position. The transmission wheel of the detection module is connected to the second servo motor, and the transmission wheel of the rotation detection module is connected to the transmission wheel of the detection module through the synchronous belt keyway. The three work together to synchronize the rotational movement of the second servo motor to the probe of the rotation detection module. The synchronous belt is connected to the transmission wheels of the rotation detection module and the detection module through keyways to drive the probe to rotate. The lens fixture is connected to the transmission base so that the central axis of the lens coincides with the central axis of the probe. The lens is connected to the lens holder and is connected to the SD-OCT unit through an optical fiber. The outgoing light of the SD-OCT unit is incident parallel to the MEMS galvanometer through the characteristics of free space propagation of spatial light. The outgoing light is reflected to the surface of the cylindrical inner wall part through the free space propagation mode of the MEMS galvanometer, and returns to the MEMS galvanometer, lens, optical fiber, and SD-OCT unit along the original path in turn, and the optical axis of the outgoing light coincides with the central axes of the lens and the probe.

5. The flaw detection system according to claim 1, characterized in that, The installation fixture is bolt - connected to the tailstock and is connected and fitted with the cylindrical inner - wall part. The central axis of the cylindrical inner - wall part installed on the installation fixture coincides with the central axis of the probe.

6. The flaw detection system according to claim 1, characterized in that, The integrated coding driver is electrically connected to the photoelectric limit switch, the first servo motor, the second servo motor, the power supply, and the signal transceiver and control unit. It supplies the direct current of the power supply to the photoelectric limit switch, the first servo motor, and the second servo motor, controls the rotation of the first servo motor and the second servo motor according to the control instructions issued by the signal transceiver and control unit, receives the electrical signals from the photoelectric limit switch, judges whether the first servo motor reaches the limit. If it reaches the limit, it will send an instruction to the signal transceiver and control unit, and the signal transceiver and control unit will stop the rotation of the first servo motor according to the feedback adjustment.

7. The flaw detection system according to claim 1, characterized in that, The SD - OCT unit collects the image information within the depth range of the preset detection plane by controlling the light emission of the light source and the cooperative scanning of the MEMS galvanometer. The SD - OCT unit is electrically connected to the power supply, the MEMS galvanometer, and the signal transceiver and control unit and is controlled by the signal transceiver and control unit.

8. The flaw detection system according to claim 1, wherein The signal transceiver and control unit is electrically connected to the integrated coding driver and the SD - OCT unit. It sends electrical signals to the integrated coding driver to control the rotation parameters of the first servo motor and the second servo motor, and sends the rotation parameters and the digital signals collected by the SD - OCT unit to the image processing and display unit. It receives the signals returned by the photoelectric limit switch via the integrated coding driver, judges whether the first servo motor reaches the limit. If the first servo motor reaches the limit at this time, the signal transceiver and control unit will send an electrical signal to the integrated coding driver and control the first servo motor to stop moving.

9. The flaw detection system according to claim 1, wherein The image processing and display unit is electrically connected to the signal transceiver and control unit. It reconstructs the three - dimensional image of the inner surface of the cylindrical inner - wall part according to the rotation parameters sent by the signal transceiver and control unit and the digital signals collected by the SD - OCT unit, obtains the scratch information inside the cylindrical inner - wall part, calculates the depth, width, and position information of the scratch according to this information, and stores it locally in the form of tables and pictures.

10. A flaw detection method using the flaw detection system according to claim 1, characterized in that, It includes the following steps: Input the detection requirement signal into the signal transceiver and control unit. At this time, the signal transceiver and control unit sends the corresponding rotation parameters to the first servo motor of the stepping module and the second servo motor of the detection module according to the detection requirement signal, and sends an imaging instruction to the SD - OCT unit. After receiving the imaging instruction, the SD - OCT unit controls the light source to emit laser light. The laser light reaches the lens of the detection module through the optical fiber and is incident on the inner surface of the cylindrical inner - wall part in the form of free - space light propagation, reflects and scatters with the scratches on the inner wall of the inner - wall part, and part of the light returns to the SD - OCT unit along the original path. When the laser is incident on the inner surface of the inner - wall part, the signal transceiver and control unit sends an electrical signal to the integrated coding driver according to the input detection requirement signal, controls the first servo motor and the second servo motor to rotate. While the first servo motor moves back and forth, the second servo motor rotates synchronously to perform an overall scan of the inner wall of the inner - wall part. The signal transceiver and control unit integrates the electrical signals collected by the SD-OCT unit and the digital signals corresponding to the input detection requirement signals, and then uniformly converts them into digital signals and sends them to the image processing and display unit. The image processing and display unit processes the digital signals and displays the relevant information about the scratches inside the inner wall part.

Images