A flaw detection system and method

Abstract

The present application relates to the technical field of industrial detection, and particularly relates to a flaw detection system and method, comprising: 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 transceiving and control unit, an image processing and display unit. The flaw detection system and method in the present application utilize SD-OCT and other optical path point technologies and introduce a MEMS galvanometer to control the equal optical path points of the SD-OCT unit on the surface of the cylindrical inner wall. When the inner wall has a minimum precision micron-level indentation or protrusion flaw, the system automatically records the defect position image. The system is not affected by ambient light and provides a flaw detection mode with high measurement precision and high automation degree.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial detection, in particular to a flaw detection system and method. BACKGROUND

[0002] With the global manufacturing industry accelerating towards high precision and intelligentization, the machining quality of precision parts has become a core indicator to measure the performance of high-end equipment. Especially in the field of mechanical manufacturing and processing, cylindrical parts as the key carriers of transmission structure (such as automobile engine accumulator, gear shaft sleeve, hydraulic piston ring, etc.), the inner wall geometric precision directly affects the sealing, wear resistance and transmission efficiency of the power system. Taking the automobile industry as an example, if the roundness error of the piston ring of the internal combustion engine increases by 1 micrometer, the fuel consumption rate may increase by 0.3%-0.5%; if the inner wall roughness of the ring-shaped part of the gear box exceeds the standard, it may cause high-frequency vibration, resulting in a 15%-20% reduction in the service life of the transmission system. Similarly, the inner wall precision error of cylindrical parts such as high-pressure fuel pipelines in the aerospace field and micro-implant cannulas in the medical device field is directly related to the safety and reliability of the equipment. These needs have driven the precision manufacturing industry to have an urgent need for micron-level detection technology, but the limitations of existing detection methods have seriously hindered the upgrading of the industry.

[0003] The current industry mainly relies on two methods for quality detection of cylindrical parts, but the technical bottlenecks are increasingly prominent:

[0004] I. Limitations of traditional detection technology

[0005] 1. Manual measurement method: 1) The operator uses contact tools such as calipers, plug gauges, and pneumatic gauges for manual measurement, which is still dominant in small and medium-sized enterprises, but its defects are significant: uncontrollable human error: the difference between repeated measurements can reach 2-5 microns due to problems such as measurement angle deviation and uneven touch pressure, while the tolerance band of precision parts usually requires to be controlled within ±3 microns; 2) Insufficient equipment precision: the resolution of mechanical gauges (such as vernier calipers) is generally 10-50 microns, which cannot meet the detection needs of super-precision parts; 3) Efficiency and cost issues: manual detection of a single piece takes 10-15 minutes, and the gauge needs to be calibrated frequently.

[0006] 2. Large-scale automated detection equipment: High-end equipment represented by coordinate measuring machines (CMM) and laser scanners can achieve non-contact measurement, but its application limitations are outstanding: 1) Poor spatial adaptability: CMM equipment usually occupies an area of more than 5 square meters, requiring independent detection stations, and is difficult to integrate into a compact assembly line; 2) Detection accuracy and curvature adaptability contradiction: Traditional laser triangulation method has 10-20 microns of edge distortion when measuring high-curvature inner walls (deep holes with a diameter of less than 30mm); 3) Economic barriers: The procurement cost of imported CMM is more than 1.5 million yuan, and the annual maintenance cost accounts for 25%-30%. Small and medium-sized enterprises cannot afford it, resulting in a technology penetration rate of less than 20%. In addition, such equipment has strict requirements for the positioning fixture of the workpiece, and the changeover debugging time is as long as 2-4 hours, which seriously restricts the multi-variety and small-batch production mode.

[0007] II. Special technical challenges of cylindrical part detection

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

[0009] However, the current market mainstream equipment does not fully meet the above needs. Manual detection method is limited by the precision and efficiency ceiling, and large-scale equipment is difficult to popularize due to cost and adaptability problems. In order to realize high-precision automated detection of parts with cylindrical inner walls, the present application provides an OCT-based cylindrical inner wall flaw detection system and method, which can realize micron-level, high-automation inner wall trace detection. SUMMARY

[0010] The embodiment of the present application provides 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 application, a flaw detection system is provided, comprising: 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 transceiving and control unit, an image processing and display unit; wherein:

[0012] The detection requirement signal is input to the signal transceiving and control unit, at this time the signal transceiving 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, and sends the imaging instruction to the SD-OCT unit according to the detection requirement signal;

[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 the optical fiber and is incident on the inner surface of the cylindrical inner wall part in a free space optical propagation manner, is reflected and scattered by the scratch on the inner wall of the inner wall part, and part of the light returns to the SD-OCT unit along the original path;

[0014] At the same time that 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 encoder driver according to the input detection requirement signal, controls the first servo motor and the second servo motor to rotate, and synchronously rotates the second servo motor while the first servo motor reciprocates, so as to scan the inner wall of the inner wall part as a whole.

[0015] 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, and then converts them into a digital signal and sends them to the image processing and display unit, which processes the digital signal and displays the related information of the scratch inside the inner wall part.

[0016] Further, the stepping module is composed of the first servo motor, the single-shaft driver, the photoelectric limit switch and the baffle.

[0017] The first servo motor is electrically connected with the integrated encoder driver and rotates according to the driving of the integrated encoder driver.

[0018] The single-shaft driver is a sliding block guide rail, which includes a motor fixing base, a U-shaped groove, a screw rod, a sliding block and a tailstock. The first servo motor is installed at the motor fixing base, the motor fixing base is connected with the U-shaped groove and the screw rod, and the first servo motor converts the rotary motion into reciprocating motion through the screw rod. The U-shaped groove is connected with the motor fixing base and the tailstock, and is used for clamping the two sides of the sliding block, so that the sliding block moves in parallel reciprocating motion along the direction indicated by the screw rod. The screw rod provides a linear reciprocating motion path for the sliding block. The sliding block is clamped on both sides by the U-shaped groove, so that the sliding block moves in parallel reciprocating motion. The tailstock is connected with the screw rod and the U-shaped groove, and fixes one end of the screw rod.

[0019] The photoelectric limit switch is connected with one side of the U-shaped groove and is electrically connected with the integrated encoder driver.

[0020] The baffle is connected with one side of the sliding block and the same side of the photoelectric limit switch. The photoelectric limit switch uses both sides of the U-shaped groove as the transmitting and receiving end of the optical signal. When the optical signal is blocked by the baffle, the photoelectric limit switch sends an electrical signal to the integrated encoder driver, and then the integrated encoder driver sends a stop rotating signal to the first servo motor, thereby achieving the limiting effect.

[0021] Further, the rotation detection module comprises a probe, a MEMS scanner, a bearing seat fixing member, a bearing, a bearing seat, a clamping ring, a conductive slip ring and a transmission wheel;

[0022] The probe is coaxially installed in the order of the bearing, the bearing seat, the bearing, the clamping ring, the conductive slip ring and the transmission wheel, wherein the bearing seat is coaxially installed with the cylindrical gap of the bearing seat fixing member, and the clamping ring, the conductive slip ring and the transmission wheel are all connected and locked from one side;

[0023] The MEMS scanner is electrically connected with the conductive slip ring and the SD-OCT unit, the MEMS scanner is powered by the power supply through the conductive slip ring and is controlled by the SD-OCT unit, the MEMS scanner swings and scans under the control of the SD-OCT unit to realize one-dimensional data acquisition, at this time, the rotation of the probe and the reciprocating motion of the slider realize the inner wall surface scanning of the cylindrical inner wall part;

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

[0025] The conductive slip ring is electrically connected with the power supply and the SD-OCT unit, and is in close proximity to the clamping ring in space, the power supply supplies power to the MEMS scanner through the conductive slip ring, and the SD-OCT unit controls the MEMS scanner to receive and collect signals through the conductive slip ring;

[0026] The transmission wheel is connected with the probe to fix the conductive slip ring, and is connected with the synchronous belt key groove, and the transmission wheel is driven to rotate by the second servo motor, and the probe is rotated by the synchronous belt and the transmission wheel.

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

[0028] The detection module is bolted with the slider, and coincides with the central axis of the probe and the cylindrical inner wall part;

[0029] The transmission base is connected with the rotation detection module, the second servo motor and the slider, and the detection module and the slider installed on the slider are synchronously reciprocated;

[0030] The second servo motor is electrically connected with the integrated encoder driver, rotates according to the driving of the integrated encoder driver, and is connected to the transmission base, so that the transmission wheel of the rotation detection module is in flush position with the transmission wheel of the detection module;

[0031] The transmission wheel of the detection module is connected with the second servo motor, the transmission wheel of the rotating detection module and the transmission wheel of the detection module are connected through the synchronous belt key groove, and the rotation of the second servo motor is synchronized to the probe of the rotating detection module through the cooperation of the three; the synchronous belt is connected to the transmission wheel of the rotating detection module and the transmission wheel of the detection module through the key groove, and drives the probe to rotate;

[0032] The lens fixing part is connected with the transmission base, so that the central axis of the lens coincides with the central axis of the probe;

[0033] The lens is connected with the lens fixing base, and is connected with the SD-OCT unit through an optical fiber; the outgoing light of the SD-OCT unit is parallelly incident on the MEMS galvanometer through the characteristic of free propagation of spatial light, the outgoing light is reflected to the surface of the cylindrical inner wall part through the free propagation of spatial light via the MEMS galvanometer, and is returned to the MEMS galvanometer, the lens, the optical fiber and the SD-OCT unit in turn, and the optical axis of the outgoing light coincides with the central axes of the lens and the probe.

[0034] Further, the mounting clamp is connected with the tailstock bolt and is connected with the cylindrical inner wall part; the central axis of the cylindrical inner wall part mounted on the mounting clamp coincides with the central axis of the probe.

[0035] Further, the integrated encoder driver is electrically connected with the photoelectric limit switch, the first servo motor, the second servo motor, the power supply and the signal transceiving and control unit; the direct current of the power supply is supplied to the photoelectric limit switch, the first servo motor and the second servo motor; the rotation of the first servo motor and the second servo motor is controlled according to the control instruction issued by the signal transceiving and control unit; the electrical signal of the photoelectric limit switch is received, and it is judged whether the first servo motor reaches the limit; if the limit is reached, an instruction is issued to the signal transceiving and control unit; the signal transceiving and control unit stops the rotation of the first servo motor according to the feedback adjustment.

[0036] Further, the SD-OCT unit collects image information in a preset detection plane depth range through cooperation of controlling the outgoing light of the light source and the MEMS galvanometer; the SD-OCT unit is electrically connected with the power supply, the MEMS galvanometer and the signal transceiving and control unit, and is controlled by the signal transceiving and control unit.

[0037] Further, the signal transceiving and control unit is electrically connected with the integrated encoding driver and the SD-OCT unit, sends an electric signal to the integrated encoding 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, receives the signals returned by the photoelectric limit switch through the integrated encoding driver, and judges whether the first servo motor reaches the limit, if the first servo motor reaches the limit at this time, the signal transceiving and control unit sends an electric signal to the integrated encoding driver and controls the first servo motor to stop moving.

[0038] Further, the image processing and display unit is electrically connected with the signal transceiving and control unit, reconstructs the three-dimensional image of the inner surface of the cylindrical inner wall part according to the rotation parameters sent by the signal transceiving 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 the information, and stores the information in a table and a picture to the local.

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

[0040] The detection requirement signal is input to the signal transceiving and control unit, at this time, the signal transceiving 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, and sends an imaging instruction to the SD-OCT unit according to the detection requirement signal;

[0041] After receiving the imaging instruction, the SD-OCT unit controls the light source to emit laser, the laser 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 optical propagation mode, is reflected and scattered with the scratch on the inner wall of the inner wall part, and part of the light returns to the SD-OCT unit by the original route;

[0042] At the same time that the laser is incident on the inner surface of the inner wall part, the signal transceiving and control unit sends an electric signal to the integrated encoding driver according to the input detection requirement signal, controls the first servo motor and the second servo motor to rotate, and the second servo motor rotates synchronously while the first servo motor reciprocates, thereby scanning the inner wall of the inner wall part as a whole;

[0043] The signal transceiving and control unit integrates the electric signals collected by the SD-OCT unit and the digital signals corresponding to the input detection requirement signal, converts them into digital signals, and sends them to the image processing and display unit, and the image processing and display unit processes the digital signals and displays the related information of the internal scratch of the inner wall part.

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

[0045] A processor for running a program, wherein the program performs the flaw detection method of any one of the above when running.

[0046] The flaw detection system and method in the embodiment of the present application utilize the optical path point technology such as SD-OCT and introduce MEMS galvanometer to control the equal optical path point of the SD-OCT unit on the inner wall surface of the cylinder, when the inner wall appears flaw with micron level concave or convex with minimum precision, the system automatically records the defect position image. The system is not affected by the ambient light, and provides a flaw detection mode with high measurement precision and high automation degree. BRIEF DESCRIPTION OF DRAWINGS

[0047] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the principles of the present application, and, together with the description, do not limit the present application. In the drawings:

[0048] Figure 1a Fig. 1 is a front view of the step module in the present application;

[0049] Figure 1b Fig. 3 is a schematic view of the photoelectric limit switch and the baffle in the present application;

[0050] Figure 2a Fig. 5 is a front view of the rotation detection module in the present application;

[0051] Figure 2b Fig. 7 is a side view of the rotation detection module in the present application;

[0052] Figure 2c Fig. 9 is an A-A sectional view of the rotation detection module in the present application; Figure 2a

[0053] Fig. 11 is a front view of the detection module in the present application; Figure 3a

[0054] Fig. 13 is an A-A sectional view of the detection module in the present application. Figure 3b Figure 3a Fig. 15 is a schematic view of the detection module in the present application.

[0055] BRIEF DESCRIPTION OF DRAWINGS

[0056] ​1-Stepping module, 101-First servo motor, 102-Single shaft driver, 1021-Motor fixing seat, 1022-U-shaped groove, 1023-Screw rod, 1024-Slider, 1025-Tailstock, 103-Photoelectric limit switch, 104-Baffle, 2-Rotating detection module, 201-Probe, 202-MEMS galvanometer, 203-Bearing seat fixing piece, 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-Synchronous belt, 305-Lens fixing piece, 306-Lens, 4-Mounting clamp, 5-Cylindrical inner wall part, 6-Power supply, 7-Integrated encoder driver, 8-SD-OCT unit, 9-Optical fiber, 10-Signal transceiving and control unit, 11-Image processing and display unit. DETAILED DESCRIPTION

[0057] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without making creative efforts should belong to the scope of protection of the present application.

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

[0059] The present application utilizes SD-OCT and other optical path point technologies and introduces a MEMS galvanometer to control the equal optical path point of the SD-OCT unit on the surface of the cylindrical inner wall. When the inner wall has a minimum precision of micron-level indentation or protrusion damage, the system automatically records the defect position image. The system is not affected by ambient light, and provides a high-precision and high-automation flaw detection system and method.

[0060] A flaw detection system comprises: a stepping module 1, a rotation detection module 2, a detection module 3, a mounting clamp 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 transceiving and control unit 10, and an image processing and display unit 11.

[0061] Referring to Figure 1a ), the stepping module 1 is composed of a first servo motor 101, a single-shaft driver 102, a photoelectric limit switch 103, and a baffle 104, and functions to realize accurate movement of a sliding block 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 driving of the integrated encoder driver 7.

[0063] The single-shaft driver 102 is a sliding block guide rail, which comprises a motor fixing base 1021, a U-shaped groove 1022, a screw rod 1023, the sliding block 1024, and a tailstock 1025. The first servo motor 101 is installed at the motor fixing base 1021, which is bolted to the U-shaped groove 1022 and the screw rod 1023. The first servo motor 101 converts the rotary motion into reciprocating motion by means of a shaft coupling. The U-shaped groove 1022 is bolted to the motor fixing base 1021 and the tailstock 1025, and is used to clamp both sides of the sliding block 1024, so that the sliding block 1024 moves in parallel reciprocating motion according to the direction of the screw rod 1023. The screw rod 1023 provides a linear reciprocating motion path for the sliding block 1024. The sliding block 1024 is installed in threaded cooperation with the external threads of the screw rod 1023 through internal threads, and is clamped by the U-shaped groove 1022 on both sides of the sliding block 1024, so that the sliding block 1024 moves in parallel reciprocating motion. The tailstock 1025 is bolted to the screw rod 1023 and the U-shaped groove 1022, and fixes one end of the screw rod 1023.

[0064] Referring to Figure 1b ), the photoelectric limit switch 103 is a pair of U-shaped groove type photoelectric switches, which are bolted to one side of the U-shaped groove 1022 and electrically connected to the integrated encoder driver 7.

[0065] The baffle 104 is bolted to one side of the sliding block 1024 and the same side as the photoelectric limit switch 103, and forms a limit system with the photoelectric limit switch 103. The photoelectric limit switch 103 is U-shaped, and the two sides of the U-shaped groove are used as the transmitting and receiving ends of the optical signal. When the optical signal is blocked by the baffle 104, the photoelectric limit switch 103 sends an electrical signal to the integrated encoder driver 7, and then the integrated encoder driver 7 sends a stop rotating signal to the first servo motor 101, thereby realizing the limiting function.

[0066] The light-electric limit switch 103 and the baffle 104 mounted to the slider 1024 form a limit system to limit the linear reciprocating motion range of the slider 1024, so that the probe 201 is prevented from colliding with the bottom end of the cylindrical inner wall part 5 and deforming due to the motion of the slider 1024 beyond the input value caused by the failure of the brake system or the encoding system between the single-axis driver 102 and the integrated encoding driver 7.

[0067] Referring to Figure 2a )、 Figure 2b )、 Figure 2c The rotation detection module 2 includes a probe 201, a MEMS mirror 202, a bearing seat fixing member 203, a bearing 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 having a coaxial cylindrical boss in the middle for abutting 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, wherein the bearing seat 205 is coaxially installed with the cylindrical gap of the bearing seat fixing member 203, and the clamping ring 206, the conductive slip ring 207, and the transmission wheel 208 are all locked by screw connection from one side through a locking screw.

[0068] The diameter of the probe 201 is greater than the required space diameter for installing the MEMS mirror 202 and less than the inner diameter of the cylindrical inner wall part 5.

[0069] The MEMS mirror 202 is a one-dimensional MEMS mirror module, which is fixed to the probe 201 through the gap of the probe 201 by bolt connection and is electrically connected with the conductive slip ring 207 and the SD-OCT unit 8. The MEMS mirror 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 mirror 202 will swing and scan under the control of the SD-OCT unit 8 to realize one-dimensional data acquisition. At this time, the rotation of the probe 201 and the reciprocating motion of the slider 1024 are coordinated to realize the scanning of the inner wall surface of the cylindrical inner wall part 5.

[0070] The bearing seat fixing member 203 is bolted with the slider 1024 and the bearing seat 205, and the reciprocating motion of the rotation detection module 2 is realized through the connection.

[0071] The bearing 204 is installed at both ends of the bearing seat 205, and the probe 201, the bearing 204, the bearing seat 205, and the bearing 204 are pressed tightly by the clamping ring 206 to fix the probe 201 and the bearing seat 205, so that the probe 201 rotates around the central axis of the bearing 204.

[0072] The bearing housing 205 is bolted to the bearing housing fastener 203, providing a coaxial mounting structure for the bearing 204.

[0073] The clamping ring 206 is a metal ring with a pin hole. It is connected to the probe 201 by a set screw to fix the position of the probe 201, bearing 204, bearing seat 205, and bearing 204, preventing the four components from sliding back and forth around the bearing seat and allowing the probe 201 to rotate under the action of the bearing 204.

[0074] The conductive slip ring 207 is electrically connected to the power supply 6 and the SD-OCT unit 8, and is spatially adjacent to the clamping ring 206. 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 acquired signals through the conductive slip ring 207.

[0075] The transmission wheel 208 is a ring with a pin hole, which is screwed to the probe 201 by a set screw to fix the conductive slip ring 207 and is connected to the keyway of the synchronous belt 304. The second servo motor 302 rotates to drive the transmission wheel 303, and the probe 201 rotates 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 component 305, and a lens 306. The detection module 3 is bolted to the slider 1024 and coincides with the central axis of the probe 201 and the cylindrical inner wall part 5.

[0077] The transmission base 301 is bolted to the rotation detection module 2, the second servo motor 302 and the slider 1024. Its function is to synchronize the detection module 3 installed on the slider 1024 and the slider 1024 to perform reciprocating motion.

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

[0079] The second servo motor 302 is an integrated closed-loop stepper 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 bolts. The transmission wheel 303 on the rotating shaft of the second servo motor 302 is screwed and connected by set screws. The installation of the second servo motor 302 makes the transmission wheel 303 and the transmission wheel 208 flush.

[0080] The transmission wheel 303 is a ring with a pin hole, and is screwed to the second servo motor 302 through a set screw. The transmission wheel 303 is connected to the transmission wheel 208 through a key groove of a synchronous belt 304, and the three work together to synchronize the rotating movement of the second servo motor 302 to the probe 201 of the rotating detection module 2.

[0081] The synchronous belt 304 is connected to the transmission wheel 208 and the transmission wheel 303 through a key groove, and drives the probe 201 to rotate.

[0082] The lens fixing part 305 is screwed to the transmission base 301, so that the central axis of the lens 306 coincides with the central axis of the probe 201.

[0083] The lens 306 is screwed to the lens fixing seat 305, and is connected to the SD-OCT unit 8 through an optical fiber 9. The outgoing light of the SD-OCT unit 8 is parallelly incident on the MEMS galvanometer 202 through the characteristic of free propagation of spatial light, and is reflected to the surface of the cylindrical inner wall part 5 through the free propagation of spatial light via the MEMS galvanometer 202, and returns to the MEMS galvanometer 202, the lens 306, the optical fiber 9, and the SD-OCT unit 8 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 mounting clamp 4 is a circular ring with an internal thread, and is bolted to the tailstock 1025 and threadedly connected to the outer thread of the cylindrical inner wall part 5. The central axis of the cylindrical inner wall part 5 mounted to the mounting clamp 4 coincides with the central axis of the probe 201.

[0085] The mounting clamp 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 of the mounting clamp 4 and the cylindrical inner wall part 5 differs by ≤1mm, 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 automobile accumulators, automobile valve sleeves, hydraulic piston rings, and the like.

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

[0088] The integral code driver 7 is electrically connected with the photoelectric limit switch 103, the first servo motor 101, the second servo motor 302, the power supply 6 and the signal transceiving and control unit 10, 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 instruction sent by the signal transceiving and control unit 10, receives the electric signal of the photoelectric limit switch 103, judges whether the first servo motor 101 reaches the limit, sends the instruction to the signal transceiving and control unit 10 if the limit is reached, and the signal transceiving 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 center wavelength of 850 nm as a system light source, acquires the image information in the preset detection plane depth range by controlling the light emission of the light source and the cooperation scanning of the MEMS scanning mirror 202, and is electrically connected with the power supply 6, the MEMS scanning mirror 202 and the signal transceiving and control unit 10 and controlled by the signal transceiving and control unit 10.

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

[0091] The signal transceiving and control unit 10 is electrically connected with the integral code driver 7 and the SD-OCT unit 8, sends the electric signal to the integral code 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 signal acquired by the SD-OCT unit to the image processing and display unit 11, receives the signal returned by the photoelectric limit switch 103 through the integral code driver 7, judges whether the first servo motor 101 reaches the limit, and sends the electric signal to the integral code driver 7 and controls the first servo motor 101 to stop moving if the first servo motor 101 reaches the limit at this time.

[0092] The image processing and display unit 11 is electrically connected with the signal transceiving and control unit 10, 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 transceiving and control unit 10 and the digital signal acquired by the SD-OCT unit, thereby obtaining the scratch information inside the cylindrical inner wall part 5, and calculating the depth, width and position information of the scratch according to the information, and storing the information in the form of tables and pictures to the local.

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

[0094] 1. According to the detection requirements input to 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 imaging instructions to the SD-OCT unit 8;

[0095] 2. After the SD-OCT unit 8 receives the signal, the light source emits laser, the laser passes through the optical fiber 9 to the lens 306 and propagates in free space in turn through the lens fixing part 305, the MEMS galvanometer 202, and is incident to the inner surface of the cylindrical inner wall part 5, and is reflected and scattered with the scratch on the inner wall, part of the light returns to the SD-OCT unit 8 through the original route;

[0096] 3. While the laser is incident to the inner surface of the cylindrical inner wall part 5 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, controls the first servo motor 101 and the second servo motor 302 to rotate, and controls the reciprocating motion of the slider 1024 while the first servo motor 101 rotates, and 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 scanning of the whole inner wall of the cylindrical inner wall part 5;

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

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

[0099] A processor for running a program, wherein the program performs any one of the above-described flaw detection methods when running.

[0100] The above-mentioned embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0101] In the above-mentioned embodiments of the present application, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0102] In several embodiments provided in the present application, it should be understood that the disclosed technology can be implemented by other ways. Among them, the system embodiments described above are only illustrative, for example, the division of units can be a logical function division, and actual implementation can have another division way, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units or modules shown or discussed can be indirect coupling or communication connection between the units or modules through some interfaces, and can be electrical or other forms.

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

[0104] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0105] If the integrated unit is realized 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 solutions of the present application essentially or the part of the prior art that contributes to the technical solutions or all or part of the technical solutions can be embodied in the form of a software product, which is stored in a storage medium and includes a plurality of 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 embodiments of the present application. The foregoing storage medium includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0106] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A flaw detection system, characterized in that, It utilizes SD-OCT equal optical path point technology and introduces MEMS galvanometers to control the equal optical path point of the SD-OCT unit on the surface of the cylindrical inner wall. The flaw detection system includes: 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: The detection requirement signal is input to 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 stepper module and the second servo motor of the detection module according to the detection requirement signal, and sends the imaging command to the SD-OCT unit. After receiving the imaging command, 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 free space light propagation mode. It is reflected and scattered by the scratches on the inner wall of the inner wall part, and part of the light returns to the SD-OCT unit through the original path. While 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 encoder driver according to the input detection requirement signal, which 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 a whole scan of the inner wall of the inner wall part. The signal transceiver and control unit integrates the electrical signals acquired by the SD-OCT unit and the digital signals corresponding to the input detection requirements signals, 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 relevant information about the internal scratches of the inner wall parts.

2. The flaw detection system according to claim 1, characterized in that, The stepper module consists of a first servo motor, a single-axis driver, a photoelectric limit switch, and a baffle. The first servo motor is electrically connected to the integrated encoder driver and rotates according to the drive of the integrated encoder driver; The single-axis driver is a slider guide rail, including a motor mount, a U-shaped groove, a lead screw, a slider, and a tailstock. A first servo motor is mounted on the motor mount, which is connected to the U-shaped groove and the lead screw. The first servo motor converts its rotary motion into reciprocating motion via the lead screw. The U-shaped groove, connected to the motor mount and the tailstock, is used to hold the two sides of the slider, causing the slider to perform parallel reciprocating motion in the direction of the lead screw. The lead screw provides a linear reciprocating motion path for the slider. The U-shaped groove holds the two sides of the slider, enabling it to perform parallel reciprocating motion. The tailstock is connected to the lead screw and the U-shaped groove, fixing one end of the lead screw. The photoelectric limit switch is connected to one side of the U-shaped groove and is electrically connected to the integrated encoder driver; The baffle is connected to the slider on one side and to the photoelectric limit switch on the same side. The photoelectric limit switch uses the two sides of the U-shape as the transmitting and receiving ends of the light signal. When the light signal is blocked by the baffle, the photoelectric limit switch sends an electrical signal to the integrated encoder driver. Then the integrated encoder driver sends a stop rotation signal to the first servo motor to achieve the limit function.

3. The flaw detection system according to claim 1, characterized in that, The rotation detection module includes a probe, a MEMS galvanometer, a bearing housing fixture, a bearing, a bearing housing, 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 drive wheel. The bearing housing is coaxially installed with the cylindrical notch of the bearing housing fixing part. The clamping ring, conductive slip ring and drive 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 controlled by the SD-OCT unit. Under the control of the SD-OCT unit, the MEMS galvanometer will perform oscillating scanning to achieve one-dimensional data acquisition. At this time, in conjunction with the rotation of the probe and the reciprocating motion 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, enabling the reciprocating motion of the rotation detection module. The bearing is installed at both ends of the bearing housing, and the probe, bearing, bearing housing, and bearing are pressed together by clamping rings. The bearing housing is connected to the bearing housing fixture. The clamping ring is connected to the probe to fix the position 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 spatially adjacent to the clamping ring. 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 acquired signals through the conductive slip ring. The drive wheel is connected to the probe, a fixed conductive slip ring is attached, and it is connected to the keyway of the synchronous belt. The second servo motor rotates to drive the drive wheel, which in turn drives the probe to rotate via the synchronous belt and the drive 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 holder, and a lens; The detection module is bolted to the slider and coincides with the central axis 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, so that the detection module installed on the slider and the slider can move back and forth synchronously. 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. 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 level 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 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 timing belt is connected to the drive wheel of the rotation detection module and the drive wheel of the detection module via a keyway, which drives the probe to rotate; The lens mounting bracket 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 mount and to the SD-OCT unit via optical fiber. The light emitted from the SD-OCT unit is incident parallel to the MEMS galvanometer due to the free propagation of light in space. The emitted light is reflected by the MEMS galvanometer to the surface of the cylindrical inner wall component through the free propagation of light in space, and then returns along the same path to the MEMS galvanometer, lens, optical fiber, and SD-OCT unit. The optical axis of the emitted light coincides with the central axis of the lens and the probe.

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

6. The flaw detection system according to claim 1, characterized in that, 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 DC power to the photoelectric limit switch, the first servo motor, and the second servo motor. It controls the rotation of the first servo motor and the second servo motor according to the control commands issued by the signal transceiver and control unit. It receives the electrical signal from the photoelectric limit switch and determines whether the first servo motor has reached the limit. If it has reached the limit, it sends a command to the signal transceiver and control unit. The signal transceiver and control unit adjusts and stops the rotation of the first servo motor according to the feedback.

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

8. The flaw detection system according to claim 1, characterized in that, The signal transceiver and control unit is electrically connected to the integrated encoder driver and the SD-OCT unit. It sends electrical signals to the integrated encoder driver to control the rotation parameters of the first and second servo motors, 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 signal returned by the photoelectric limit switch through the integrated encoder driver and determines whether the first servo motor has reached the limit. If the first servo motor has reached the limit, the signal transceiver and control unit will send an electrical signal to the integrated encoder driver and control the first servo motor to stop moving.

9. The flaw detection system according to claim 1, characterized in that, The image processing and display unit is electrically connected to the signal transceiver and control unit. Based on the rotation parameters sent by the signal transceiver and control unit and the digital signals collected by the SD-OCT unit, the three-dimensional image of the inner surface of the cylindrical inner wall part is reconstructed to obtain the scratch information inside the cylindrical inner wall part. Based on this information, the depth, width and location information of the scratch are calculated and stored locally in the form of tables and pictures.

10. A flaw detection method using the flaw detection system of claim 1.

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