Eddy current detection method for welding seam on inner surface of disc drum assembly of high-pressure compressor

Abstract

The invention provides an eddy current detection method for a welding seam on the inner surface of a disc-drum assembly of a high-pressure compressor, which comprises the following steps of: descending a probe connecting pipe connected with an eddy current flaw detection probe through a mechanical arm and penetrating through an axis hole of the disc-drum assembly of the high-pressure compressor and an inter-disc narrow space, so that a base section and a middle section of the probe are positioned in the narrow inter-disc space; the direct-current motor push rod drives the eddy current flaw detection probe to extend out, so that the end part of the probe moves to a welding seam area on the inner surface of the disc-drum assembly for flaw detection; the position of the probe detection end is driven by the steering engine to change, the effective detection area is increased by changing the position of the probe detection end when the probe main body is limited by a narrow inter-disc space environment, and meanwhile, the high-pressure compressor disc drum assembly rotates, so that full-coverage detection of an inner surface welding seam area is realized.

Description

Technical Field

[0001] The present invention relates to the field of information technology, and in particular to an eddy current detection method for the inner surface weld of a high-pressure compressor disc assembly. Background Art

[0002] The high-pressure compressor disc assembly is a critical component of aircraft engines, and the integrity of its internal surface welds directly impacts engine performance and safety. However, due to the disc assembly's complex structure and confined interior space, particularly the axial bore and inter-disc space, traditional inspection methods struggle to access these areas for comprehensive inspection. Even when access is possible, full weld coverage is often impossible, resulting in incomplete and unreliable inspection results. Furthermore, within such a confined space, the flexibility and accuracy of inspection equipment face significant challenges. Precise positioning and angle adjustment of the inspection probe are difficult, making it difficult to adapt to the needs of inspecting welds in diverse locations. Furthermore, space constraints hinder the use of large, high-performance inspection equipment, further limiting inspection accuracy and efficiency. These technical challenges not only increase inspection time and cost but, more importantly, can lead to potential defects being overlooked, posing safety risks. Achieving efficient, accurate, and comprehensive weld inspection within the extremely confined and complex interior of a high-pressure compressor disc assembly has become a critical technical challenge that needs to be addressed. Summary of the Invention

[0003] The present invention provides an eddy current detection method for the inner surface weld of a high-pressure compressor disc-drum assembly, which mainly includes:

[0004] The probe connecting pipe connected with the eddy current flaw detection probe is lowered by the robotic arm and passed through the axial hole of the high-pressure compressor disc-drum assembly and the narrow space between the discs, so that the base section and the middle section of the probe are located in the narrow space between the discs; the eddy current flaw detection probe is extended by the DC motor push rod, and the probe end is moved to the weld area on the inner surface of the disc-drum assembly for flaw detection; the position of the probe detection end is driven to change by the steering servo. When the probe body is restricted by the narrow space between the discs, the effective detection area is increased by changing the position of the probe detection end. At the same time, the high-pressure compressor disc-drum assembly rotates to achieve full coverage detection of the inner surface weld area.

[0005] Furthermore, the probe includes a base section base, a middle section base, an end section base, a first drive unit, a second drive unit, a probe assembly and a connecting piece, the first drive unit base is installed in the base section base, the first drive unit push rod is installed in the middle section base, and the first drive unit is used to push the middle section base to move toward the end base; the second drive unit base is installed in the middle section base, the second drive unit push rod is installed in the end section base, and the second drive unit is used to push the end section base to move toward the weld to be detected; a second mounting hole is provided on the second drive unit push rod, and a second fixing piece is provided at a position on the end section base that is adapted to the second mounting hole, and when the second drive unit push rod is installed on the end section base, the second fixing piece is inserted into the second mounting hole, and a third power cord accommodating groove is provided on the end section base.

[0006] Furthermore, the steering assembly also includes a steering servo assembly, which includes a steering servo and a rotating shaft. The steering servo is fixedly installed in the base section base, one end of the rotating shaft is rotationally connected to the steering servo, and the other end is fixedly connected to the probe assembly.

[0007] Furthermore, when the position of the probe detection end is changed by the steering servo, PWM pulse signals with different duty cycles are input to the steering servo to control the rotation of the steering servo.

[0008] Furthermore, the upper end of the probe connecting tube is connected to the front end of the robotic arm through a threaded hole.

[0009] Furthermore, when the robotic arm drives the connecting tube to move horizontally through the narrow space between the discs, the probe connecting tube is located in the axial hole, and the base section and the middle section of the probe are located in the narrow space between the discs.

[0010] Furthermore, the initial posture of the eddy current flaw detection probe is a retracted state.

[0011] Furthermore, after the probe end is moved to the weld area on the inner surface of the drum assembly for flaw detection, the position of the probe detection end is changed to increase the effective detection area when the probe body is restricted by the narrow space between the disks, thereby achieving full coverage detection of the inner surface weld area.

[0012] Furthermore, the position data of the base section base is obtained, and the relative position of the base section base and the interdisk space is detected using an infrared sensor installed on the probe to determine whether the base section base is in the narrow interdisk space.

[0013] The technical solution provided by the embodiment of the present invention may have the following beneficial effects:

[0014] The present invention discloses an eddy current detection method for the inner surface welds of a high-pressure compressor disc-drum assembly. In order to solve the problem that it is difficult to detect the welds on the inner wall of the axial center hole and the narrow inter-disc space of the high-pressure compressor disc-drum assembly, the present invention adopts a probe connecting tube in conjunction with a robotic arm to accurately send the eddy current flaw detection probe into the detection area. The DC motor controls the extension and retraction of the probe, and the servo adjusts the angle of the detection end to achieve full coverage scanning of the inner surface welds. The PWM signal is used to control the rotation of the servo to change the detection area of ​​the eddy current sensor, thereby improving the detection flexibility and accuracy. The present invention solves the problem that traditional methods have difficulty entering narrow spaces and have incomplete detection coverage, and achieves efficient and accurate detection of the inner surface welds of the high-pressure compressor disc-drum assembly, significantly improving the detection quality and efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of an eddy current detection method for the inner surface weld of a high-pressure compressor disc drum assembly.

[0016] Figure 2 This is a schematic structural diagram of a weld probe structure for the inner surface of a high-pressure compressor disc-drum assembly according to the present invention;

[0017] Figure 3 for Figure 1 A schematic diagram of the internal assembly structure of a weld probe structure for the inner surface of a high-pressure compressor disc drum assembly according to the present invention; DETAILED DESCRIPTION

[0018] To further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and examples. The present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0019] like Figure 1 In this embodiment, an eddy current detection method for the inner surface weld of a high-pressure compressor disk-drum assembly may specifically include:

[0020] Step S101, a method for eddy current detection of the inner surface weld of a high-pressure compressor disc-drum assembly, obtaining the high-pressure compressor disc-drum assembly, wherein the high-pressure compressor disc-drum assembly has an axial hole and a narrow inter-disc space, and the inner surface weld is located on the inner wall of the inter-disc space and is annular. A three-jaw chuck is used to clamp the rotating device to fix the disc-drum assembly to be tested.

[0021] Step S102: connect one end of the probe connecting tube to the robotic arm, control the robotic arm to drive the probe connecting tube through the axial hole, and move it into the inter-disk space. The other end of the probe connecting tube is connected to an eddy current flaw detection probe, and the eddy current flaw detection probe includes a base section, a middle section and a detection end connected in sequence, and the detection end is provided with an eddy current sensor.

[0022] The current position of the robotic arm is obtained to determine its relative position to the central hole of the high-pressure compressor drum assembly. The robotic arm is controlled to move so that one end of the probe connecting tube connects to the front end of the robotic arm through the threaded hole, ensuring a secure connection. The robotic arm's posture is adjusted to keep the probe connecting tube retracted, preparing to enter the central hole of the high-pressure compressor drum assembly. The robotic arm is controlled to vertically lower the probe connecting tube through the central hole of the high-pressure compressor drum assembly and into the inter-disk space. After the probe connecting tube passes through the central hole, the robotic arm is controlled to move horizontally, allowing the base and mid-section bases of the probe to enter the narrow inter-disk space. A positive 24V voltage is applied to the two DC motor actuators, causing them to extend, driving the eddy current flaw detection probe from the probe connecting tube. The position of the eddy current flaw detection probe is adjusted so that the detection end moves to the weld area on the inner surface of the high-pressure compressor drum assembly. Based on the inspection requirements, PWM pulse signals with different duty cycles are input to the steering servo to control the steering servo's rotation, driving the detection end of the eddy current flaw detection probe to change position. During testing, the three-jaw chuck starts to rotate, driving the high-pressure compressor disc-drum assembly to rotate, and cooperates with the robotic arm to scan the weld area to be tested. As the probe body is restricted by the narrow inter-disc space environment, the effective detection area is increased by changing the position of the detection end.

[0023] For example, when obtaining the current position information of the robotic arm, the X, Y, and Z coordinate data of the robotic arm are collected through sensors, and combined with the preset coordinates of the axis hole of the high-pressure compressor disc drum assembly (X0=120mm, Y0=80mm, Z0=200mm), the relative position deviation ΔX=5mm, ΔY=3mm, and ΔZ=10mm between the two is calculated. When controlling the movement of the robotic arm, the PID algorithm is used to adjust the motion trajectory of the robotic arm so that one end of the probe connecting tube is aligned with the threaded hole at the front end of the robotic arm, and the torque value is 2.5N·m to ensure a stable connection. When adjusting the posture of the robotic arm, the tilt angle of the robotic arm is detected by the posture sensor, and it is adjusted to a state parallel to the axis of the axis hole. The angle error is controlled within ±0.5°, so that the probe connecting tube remains in a retracted state with a retracted length of 50mm. The robotic arm controls the vertical descent of the probe connecting tube, driven by a stepper motor with a 1.8° step angle and a 0.01mm per step. The probe passes through the central hole and enters the inter-disk space, for a total descent distance of 150mm. After the probe connecting tube passes through the central hole, the robotic arm controls horizontal movement, driven by a linear motor at a speed of 10mm / s, allowing the base and middle sections to enter the narrow inter-disk space, a distance of 80mm. When a positive 24V voltage is applied to the two DC motor actuators, the actuators extend at a speed of 5mm / s and a length of 30mm, driving the eddy current flaw detection probe out of the probe connecting tube. To adjust the eddy current flaw detection probe position, a laser sensor detects the distance between the probe's inspection tip and the inner surface weld and adjusts it to a distance of 2mm from the weld surface. Based on inspection requirements, a PWM pulse signal with a duty cycle of 5% to 25% and a frequency of 100Hz is input to the steering servo, controlling the steering servo's rotation angle between -90° and 90°, driving the position of the inspection tip. As the probe body is restricted by the narrow inter-disk space environment, the effective scanning area is increased by changing the position of the detection end and adopting the spiral scanning algorithm. At the same time, after the three-jaw chuck drives the high-pressure compressor disc-drum assembly to rotate, full coverage detection of the inner surface annular weld area is achieved.

[0024] like Figure 2 and Figure 3 One end of the connecting tube 7 is fixedly connected to the eddy current flaw detection probe to form a probe connecting tube, and the other end is connected to the robotic arm. The robotic arm controls the probe to move along the direction of the connecting tube. The probe includes a base section base 1, a middle section base 2, a terminal section base 3, a first drive unit 4, a second drive unit 5, a probe assembly 6 and a connector 7;

[0025] The base 41 of the first drive unit 4 is mounted within the base section base 1, and the push rod 42 of the first drive unit 4 is mounted within the middle section base 2. The first drive unit 4 is used to push the middle section base 2 toward the end base 3. The base 51 of the second drive unit 5 is mounted within the middle section base 2, and the push rod 52 of the second drive unit 5 is mounted within the end section base 3. The second drive unit 5 is used to push the end section base 3 toward the weld to be inspected. The second drive unit push rod 52 is provided with a second mounting hole 521. A second fixing member is provided at a position on the end section base 3 that matches the second mounting hole 521. When the second drive unit push rod 52 is mounted on the end section base 3, the second fixing member is inserted into the second mounting hole 521. A third power cord accommodating slot 33 is provided on the end section base 3.

[0026] It also includes a steering servo assembly 9, which includes a steering servo 91 and a rotating shaft 92. The steering servo 91 is fixedly installed in the base section base 1, and one end of the rotating shaft 92 is rotationally connected to the steering servo 91, and the other end is fixedly connected to the probe assembly 6.

[0027] In this way, PWM pulse signals with different duty cycles are input to the steering servo 91 to control the rotation of the steering servo 91, and the position of the probe assembly 6 is driven to change through the rotating shaft 92. When the overall detection structure is restricted by the narrow inter-disk space environment, the effective detection area is increased by changing the probe detection position and angle, thereby achieving full coverage detection of the inner surface weld area.

[0028] Step S103: Control two DC motors to respectively drive the base section and the middle section to extend, thereby driving the detection end to move to the inner surface weld area.

[0029] Obtain the dimensional data of the high-pressure compressor drum assembly's axial center hole to determine the initial position of the robotic arm. Use the robotic arm to control the probe's vertical descent, passing through the high-pressure compressor drum assembly's axial center hole. Based on the dimensional data of the narrow space between the drums, control the probe's horizontal movement, passing through the narrow space between the drums. Obtain the base section's position data to determine whether the probe is within the narrow space between the drums. If the base section and mid-section bases are within the narrow space between the drums, input a positive 24V voltage to the two DC motor push rods. Based on the extension data of the DC motor push rods, determine whether the eddy current flaw detection probe has extended into the weld area on the inner surface of the drum assembly. If the eddy current flaw detection probe has extended into the weld area on the inner surface of the drum assembly, obtain the position data of the weld area. Based on the position data of the weld area, input PWM pulse signals with different duty cycles to the steering servo. Obtain the steering servo's rotation data to determine whether the probe's detection end position has changed. Combined with the three-jaw chuck, the high-pressure compressor drum assembly is rotated to inspect the inner surface weld area.

[0030] Specifically, the generation steps are as follows:

[0031] The dimensional data of the high-pressure compressor disc assembly's axial hole were obtained. A laser scanner was used to measure the diameter of the hole, which was 50 mm. Using 3D modeling software, the initial position coordinates of the robotic arm were calculated as (0, 0, 0). The robotic arm was used to control the vertical descent of the probe body. A servo motor drove the robotic arm at a speed of 10 mm per second, passing through the high-pressure compressor disc assembly's axial hole until the probe body reached the bottom of the axial hole. Based on the dimensional data of the narrow space between the discs, a laser radar scan determined the interdisk space to be 15 mm high and 30 mm wide. The robotic arm was controlled to move horizontally at a speed of 5 mm per second, driving the probe body through the narrow space. The position data of the base section was obtained. An infrared sensor mounted on the probe detected the relative position of the base section base and the interdisk space to determine whether the base section base was within the narrow interdisk space. If the probe base section base was within the narrow interdisk space, a 24V positive voltage was input to the two DC motor actuators through the microcontroller, driving them to extend at a speed of 2 mm per second. Based on the DC motor push rod extension data, the encoder records the push rod extension length as 12 mm, determining whether the eddy current flaw detection probe has extended into the weld area on the inner surface of the drum assembly. If the eddy current flaw detection probe has extended into the weld area on the inner surface of the drum assembly, the eddy current sensor acquires the weld area's position data and records the weld area's coordinates as (10, 15, 20). Based on the weld area's position data, the DAC module inputs a PWM pulse signal with a 25% duty cycle to the steering servo, controlling the servo's 90-degree rotation. The steering servo's rotation data is acquired, and the gyroscope detects the servo's rotation angle to determine whether the probe's detection end position has changed. Combined with the three-jaw chuck, the high-pressure compressor drum assembly is rotated to complete a full inspection of the inner surface weld area.

[0032] Step S104: Acquire a PWM control signal, where the PWM control signal includes pulse signals with different duty cycles.

[0033] Generate PWM signal control instructions based on detection requirements. Use the signal processing module to convert the control instructions into digital signals. Obtain the digital signal frequency and determine the base frequency of the PWM signal. Calculate different duty cycle parameters based on probe position adjustment requirements. Use the PWM signal generation module to combine the base frequency and duty cycle parameters. Obtain the PWM signal waveform to determine whether the signal meets the control requirements. If the signal waveform is abnormal, adjust the duty cycle parameters and regenerate it. Obtain a PWM signal that meets the requirements and transmit it to the steering servo control port. Detect changes in probe position to determine the control effect of the PWM signal.

[0034] Understandably, the generation steps are as follows:

[0035] Based on the detection requirements, PWM signal control instructions are generated, specifically setting the steering servo's rotation angle between -90° and 90°. The signal processing module converts the control instructions into digital signals with a 12-bit resolution and a sampling frequency of 10kHz. The digital signal frequency is obtained, and the PWM signal base frequency is determined to be 1kHz. Based on the probe position adjustment requirements, different duty cycle parameters are calculated, for example, 5%, 15%, and 25% corresponding to probe rotation angles of -90°, 0°, and 90°, respectively. The PWM signal generation module combines the base frequency with the duty cycle parameters to generate a PWM waveform with a period of 20ms. The PWM signal waveform is then obtained to determine whether it meets the control requirements. FFT analysis is performed to confirm that the waveform spectrum is free of distortion. If the signal waveform is abnormal, the duty cycle parameters are adjusted and regenerated, for example, changing a 2.5% duty cycle to 5%. The resulting PWM signal is transmitted to the steering servo control port, with a voltage of 5V and a current of 200mA. Detect the probe position change and determine the PWM signal control effect. The error between the actual probe angle obtained by the position sensor and the set angle is less than ±1°.

[0036] In step S105 , the servo motor provided at the detection end is controlled to rotate by a preset angle according to the PWM control signal, thereby driving the eddy current sensor on the detection end to change the detection area and scan the inner surface weld area.

[0037] According to the preset PWM control signal, a PWM pulse signal with different duty cycles is generated. The generated PWM pulse signal is transmitted to the steering servo to drive the steering servo to rotate. The rotation angle of the steering servo is obtained to determine whether it has reached the preset angle. If the rotation angle of the steering servo has not reached the preset angle, the duty cycle of the PWM pulse signal is adjusted to continue driving the steering servo to rotate. If the rotation angle of the steering servo reaches the preset angle, the adjustment of the PWM pulse signal is stopped. The rotation of the steering servo drives the position change of the detection end of the eddy current sensor. According to the position change of the detection end of the eddy current sensor, the detection area range is determined. In the weld area on the inner surface of the high-pressure compressor drum assembly, the weld area is fully covered in combination with the rotation of the drum assembly.

[0038] Exemplarily, the generation steps are as follows:

[0039] Based on the preset PWM control signal, a PWM pulse signal with a duty cycle of 5% to 25% and a frequency of 100Hz is generated to meet the driving requirements of the steering servo. The generated PWM pulse signal is transmitted to the steering servo via a signal transmission module, driving the servo to rotate in 5° increments. An angle sensor acquires the steering servo's rotation angle in real time and determines whether the current angle reaches the preset target value of 90°. If the current angle is 80°, which does not reach the preset target, the PWM pulse signal's duty cycle is adjusted to 25%, and the servo rotation continues. If the angle reaches 90°, the PWM pulse signal adjustment is stopped and the current duty cycle is locked. The rotation of the steering servo causes the eddy current sensor's detection end to shift from its initial position to the target position by 10mm. Based on the position change of the eddy current sensor's detection end, a geometric algorithm is used to calculate the detection area, determining the detection area to be a sector with a radius of 15mm. A path planning algorithm is used to generate a scanning path within the weld area on the inner surface of the high-pressure compressor drum assembly, covering 80% of the weld area. Eddy current sensors are used to conduct full coverage detection of the weld area within the planned path. The detection data is analyzed in real time by the signal processing module to generate a weld defect distribution map.

[0040] Step S106 , repeatedly performing the steps of obtaining the PWM control signal and controlling the rotation of the servo according to the PWM control signal until the full coverage detection of the inner surface weld area is completed.

[0041] Obtain the initial PWM control signal and generate a pulse signal with the corresponding duty cycle. According to the PWM control signal, drive the steering servo to rotate, and drive the eddy current flaw detection probe detection end to move. Collect the current position information of the probe detection end and record the coordinates of the current detection area. Determine whether the current position information is located in the inner surface weld area. If not, proceed to step 5. Adjust the duty cycle of the PWM control signal to generate a new pulse signal. According to the new PWM control signal, drive the steering servo to rotate, and drive the probe detection end to move to a new position. Collect the new position information of the probe detection end and update the detection area coordinates. Determine whether the new position information is located in the inner surface weld area. If not, return to step 5. If the current position information is located in the inner surface weld area, complete the detection process.

[0042] Exemplarily, an initial PWM control signal is obtained to generate a pulse signal with a duty cycle of 10%. According to the pulse signal, the steering servo is driven to rotate -45 degrees, and the eddy current flaw detection probe detection end is driven to move to the first detection position. The current position information of the probe detection end is collected and the coordinates are recorded as (x1, y1). It is determined whether the coordinates (x1, y1) cover the inner surface weld area. If not, the duty cycle of the PWM control signal is adjusted to 20% to generate a new pulse signal. According to the new pulse signal, the steering servo is driven to rotate 45 degrees, and the probe detection end is driven to move to a new position (x2, y2). The new position information of the probe detection end is collected and the coordinates are updated to (x2, y2). It is determined whether the coordinates (x2, y2) cover the inner surface weld area. If not, the duty cycle of the PWM control signal is adjusted to 25% again to generate a new pulse signal. According to the new pulse signal, the steering servo is driven to rotate 90 degrees, and the probe detection end is driven to move to a new position (x3, y3). Determine whether the coordinate (x3, y3) is located in the inner surface weld area. If so, complete the detection process.

[0043] Step S107: obtaining the signal collected by the eddy current sensor to determine whether there is a defect in the inner surface weld area.

[0044] The probe body is controlled by a robotic arm to descend vertically and pass through the axial hole of the high-pressure compressor disc-drum assembly. The probe body is controlled to move horizontally, passing through the narrow space between the discs, so that the integral probe connecting tube is located in the axial hole. A positive 24V voltage is input to the two DC motor push rods, and the push rods extend to drive the eddy current flaw detection probe. The probe tip is controlled to move to the weld area on the inner surface of the disc-drum assembly, and the eddy current sensor is turned on to collect signals. The raw signal collected by the eddy current sensor is obtained and filtered to remove noise interference. Feature extraction is performed on the filtered signal, and the signal amplitude, phase, and frequency characteristics are analyzed. The extracted signal features are compared with the preset feature threshold to determine whether the signal is abnormal. If the signal features exceed the preset threshold, the defect type of the weld area is determined based on the feature type. A test result report is generated, containing information on the defect location, type, and severity.

[0045] For example, a robotic arm controls the probe body to descend vertically through the central bore of the high-pressure compressor drum assembly to a depth of 300 mm. The probe body is then moved horizontally through the narrow space between the drums, positioning the integral probe connecting tube within the central bore. The horizontal movement distance is 150 mm. A positive 24V voltage is applied to the two DC motor push rods, causing them to extend at a rate of 5 mm per second, driving the eddy current flaw detection probe to extend 20 mm. The probe tip is then controlled to move to the weld area on the inner surface of the drum assembly. The eddy current sensor is activated for signal acquisition at a sampling frequency of 100 kHz. The raw signal from the eddy current sensor is obtained and filtered using a low-pass filter with a cutoff frequency set to 10 kHz to remove high-frequency noise. Feature extraction is performed on the filtered signal using a fast Fourier transform (FFT) to analyze the signal amplitude, phase, and frequency characteristics. The extracted amplitude range is 0.5 V to 1.5 V, the phase range is 30 degrees to 90 degrees, and the frequency range is 1 kHz to 5 kHz. The extracted signal features are compared with preset feature thresholds (amplitude threshold of 1.2V, phase threshold of 60 degrees, and frequency threshold of 3kHz) to determine if the signal is abnormal. If the signal features exceed the preset thresholds, the weld area defect type is determined based on the feature type: amplitude exceeding the limit indicates a crack defect, phase exceeding the limit indicates a porosity defect, and frequency exceeding the limit indicates an inclusion defect. A test result report is generated, including information on the defect location, type, and severity. The location accuracy is ±0.1 mm, the type classification accuracy is 95%, and the severity is categorized as low, medium, and high.

[0046] Step S108, if the detection is completed, control the DC motor to drive the base section and the middle section to retract, so that the eddy current flaw detection probe is reset, and control the mechanical arm to drive the probe connecting tube to withdraw from the axial hole to complete the detection.

[0047] Acquire the detection completion signal, which contains the current position of the probe and the detection status information. Based on the detection completion signal, generate a DC motor control instruction, which contains the reverse 24V voltage parameters. Input the reverse 24V voltage to the DC motor push rod, and the push rod retracts to reset the eddy current flaw detection probe. Acquire the probe reset completion signal, which contains the probe retraction status and position information. Based on the probe reset completion signal, generate the robot arm control instruction, which contains the vertical ascent motion parameters. The robot arm controls the probe connecting pipe to rise vertically and pass through the axial hole of the high-pressure compressor disc drum assembly. Acquire the robot arm ascent completion signal, which contains the probe connecting pipe position information. Based on the robot arm ascent completion signal, generate the robot arm horizontal movement control instruction, which contains the horizontal motion parameters. The robot arm controls the probe connecting pipe to move horizontally and completely withdraw from the axial hole of the high-pressure compressor disc drum assembly.

[0048] Specifically, a detection completion signal is obtained. The signal contains the current position of the probe and the detection status information. Specifically, the sensor collects the coordinate value of the probe in the weld area on the inner surface of the drum assembly (such as X = 150mm, Y = 200mm, Z = 300mm) and the detection status mark (such as the status code "1" indicates that the detection is completed). Based on the detection completion signal, a DC motor control instruction is generated. The instruction contains a reverse 24V voltage parameter. The PID control algorithm is used to calculate the voltage output value to ensure that the push rod retraction speed is stable at 5mm / s. A reverse 24V voltage is input to the DC motor push rod. The push rod retraction drives the eddy current flaw detection probe to reset. The push rod displacement sensor monitors the retraction distance in real time and stops when the retraction distance reaches the set value (such as 50mm). The probe reset completion signal is obtained. The signal contains the probe retraction status and position information. The probe position coordinates are updated to X = 150mm, Y = 200mm, Z = 250mm, and the retraction status mark is "0". Based on the probe reset completion signal, a robotic arm control command is generated. This command includes vertical ascent parameters. An interpolation algorithm is used to plan the motion trajectory, with a speed of 10 mm / s. The robotic arm controls the probe connecting tube to ascend vertically, passing through the axis hole of the high-pressure compressor drum assembly. A height sensor monitors the ascent height in real time, and the robot stops when the height reaches a set value (e.g., 400 mm). A robotic arm ascent completion signal is obtained, which includes the position information of the probe connecting tube. The position coordinates are updated to X = 150 mm, Y = 200 mm, and Z = 400 mm. Based on the robotic arm ascent completion signal, a robotic arm horizontal movement control command is generated. This command includes horizontal movement parameters. A path planning algorithm is used to determine the horizontal movement distance to be 200 mm and the movement speed to be 15 mm / s. The robotic arm controls the probe connecting tube to move horizontally, completely withdrawing from the axis hole of the high-pressure compressor drum assembly. The position sensor confirms the final coordinates to be X = 350 mm, Y = 200 mm, and Z = 400 mm.

[0049] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for eddy current detection of the inner surface weld of a high-pressure compressor disc assembly, characterized in that: include: The probe connecting pipe connected to the eddy current flaw detection probe is lowered by the robotic arm and passed through the axial hole of the high-pressure compressor disc-drum assembly and the narrow space between the discs, so that the base section and middle section of the probe are located in the narrow space between the discs; The eddy current flaw detection probe is extended by a DC motor push rod, so that the probe end moves to the weld area on the inner surface of the drum assembly for flaw detection; The position of the probe detection end is driven to change by the steering servo. When the probe body is restricted by the narrow inter-disk space environment, the effective detection area is increased by changing the position of the probe detection end. At the same time, the high-pressure compressor disc drum assembly rotates to achieve full coverage detection of the inner surface weld area.

2. The eddy current detection method according to claim 1, wherein: The probe includes a base section base, a middle section base, an end section base, a first drive unit, a second drive unit, a probe assembly and a connecting piece, wherein the first drive unit base is installed in the base section base, the first drive unit push rod is installed in the middle section base, and the first drive unit is used to push the middle section base to move toward the end section base; the second drive unit base is installed in the middle section base, the second drive unit push rod is installed in the end section base, and the second drive unit is used to push the end section base to move toward the weld to be detected; a second mounting hole is provided on the second drive unit push rod, and a second fixing piece is provided at a position on the end section base that matches the second mounting hole. When the second drive unit push rod is installed on the end section base, the second fixing piece is inserted into the second mounting hole, and a third power cord accommodating groove is provided on the end section base.

3. The eddy current detection method according to claim 2, wherein: The steering assembly also includes a steering servo assembly, which includes a steering servo and a rotating shaft. The steering servo is fixedly installed in the base section base, one end of the rotating shaft is rotationally connected to the steering servo, and the other end is fixedly connected to the probe assembly.

4. The eddy current detection method according to claim 3, wherein: When the position of the probe detection end is driven by the steering servo to change, PWM pulse signals with different duty cycles are input to the steering servo to control the rotation of the steering servo.

5. The eddy current detection method according to claim 2, wherein: The robotic arm is connected to the base section, and the position information of the base section is collected by a sensor and sent to a host computer.

6. The eddy current detection method according to claim 1, wherein: When the robotic arm drives the connecting tube to move horizontally through the narrow space between the discs, the probe connecting tube is located in the axial hole, and the base section and the middle section of the probe are located in the narrow space between the discs.

7. The eddy current detection method according to claim 1, wherein: A PWM pulse signal with a duty cycle of 5% to 25% and a frequency of 100Hz is input to the steering servo to control the steering servo rotation angle to be -90° to 90°, driving the position change of the detection end.

8. The eddy current detection method according to claim 1, wherein: After the probe end is moved to the weld area on the inner surface of the disc-drum assembly for flaw detection, the effective detection area is increased by changing the position of the probe detection end under the limitation of the narrow inter-disc space environment of the probe body. Combined with the three-jaw chuck to drive the high-pressure compressor disc-drum assembly to rotate, full coverage detection of the inner surface weld area is achieved.

9. The eddy current detection method according to claim 1, wherein: The position data of the base section base is obtained, and the relative position of the base section base and the interdisk space is detected by using the infrared sensor installed on the probe to determine whether the base section base is in the narrow interdisk space.

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