Surface inspection equipment and methods, storage media

Abstract

This disclosure relates to a surface inspection device, a surface inspection method, and a storage medium. The surface inspection method includes: using a first measuring unit of the surface inspection device to perform a coarse-precision rapid measurement of the object under test, obtaining coarse-precision data of the object's outline; using a control device of the surface inspection device to determine the measurement stroke and steps of the laser measuring head based on the coarse-precision data; and using a second measuring unit of the surface inspection device to complete a high-precision surface measurement of the object under test. This disclosure can achieve real-time, automatic planning of irregular detection paths and can realize high-precision, non-contact measurement of objects in confined spaces.

Description

Technical Field

[0001] This disclosure relates to the field of aero-engines, and in particular to a surface inspection device, a surface inspection method, and a storage medium. Background Technology

[0002] Civil aircraft engines have a complex structure, consisting of a large number of independent parts. The precision and fit of the parts are required to be high, and the testing requirements are stringent, posing a great challenge to assembly and testing technologies.

[0003] Assembly, as the final and most crucial stage in engine manufacturing, directly impacts the engine's final performance, reliability, and safety. For example, the dimensions of the turbine guide vane's flow channel affect the assembly accuracy of both the high-pressure and low-pressure turbines. To improve assembly quality and precision, the turbine guide vane flow channel needs to be measured during assembly. Traditional measurement methods rely on operator experience using calipers, which cannot guarantee accuracy. Therefore, research into automated measurement technology is of great significance. Coordinate measuring machines (CMMs) are also used for point-by-point or scanning measurements. While these methods offer improved accuracy, they result in fewer measurement points. Furthermore, the turbine guide vane flow channel is a torsional spatial surface with limited space; contact between the probe and the blade may cause scratches on the blade surface, affecting product quality. Summary of the Invention

[0004] In view of at least one of the above technical problems, this disclosure provides a surface inspection device, a surface inspection method, and a storage medium, which can realize high-precision, non-contact measurement of the object being measured in a confined space.

[0005] According to one aspect of this disclosure, a surface inspection device is provided, comprising a laser measuring head and a control device, wherein the laser measuring head is a dual-mode, dual-range laser measuring device, and the dual-mode, dual-range laser measuring device includes a first measuring unit and a second measuring unit, wherein:

[0006] The first measurement unit is used to perform coarse-precision rapid measurement of the object to be measured, and obtain coarse-precision data of the object's outline.

[0007] The control device is used to determine the measurement stroke and steps of the laser measuring head based on coarse-precision data;

[0008] The second measurement unit is used to perform high-precision surface measurement of the object to be measured.

[0009] In some embodiments of this disclosure, the dual-mode, dual-range laser measurement device further includes a laser, a focusing lens, and at least one diffractive optical element, wherein:

[0010] A focusing lens is used to focus the laser beam emitted by a laser.

[0011] Diffractive optical elements are used to split a laser beam so that the split laser beam is incident on the surface of the object to be measured.

[0012] The first and second measurement units are used to image the light scattered and returned from the surface of the object under test, and to determine the distance between the laser and the surface of the object under test.

[0013] In some embodiments of this disclosure, the surface inspection device further includes a motion actuator and a motion controller, wherein:

[0014] The laser measuring head is mounted on the motion actuator;

[0015] The control device controls the motion controller to drive the motion actuator, thereby enabling the laser measuring head to move.

[0016] In some embodiments of this disclosure, the first measuring unit is used to quickly detect the surface of the object to be measured and to feed back the detection data to the control device;

[0017] The control device is used to process the detection data to obtain the distance between the laser head and the surface of the object to be measured, as well as the shape of the object; to determine whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance; if the distance between the laser head and the surface of the object to be measured in any direction is less than or equal to the predetermined distance, the motion controller controls the motion actuator to stop moving in that direction; if the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the motion controller controls the motion actuator to continue moving in that direction, thus determining the optimal measurement stroke.

[0018] In some embodiments of this disclosure, the first measuring unit and the second measuring unit operate simultaneously during the measurement stroke.

[0019] In some embodiments of this disclosure, the motion actuator further includes a micromotor;

[0020] A diffractive optical element is used to split a laser beam into two mutually perpendicular beam arrays. The beam array in the first direction is scanned by a scanning device driven by a micromotor, while the beam array in the second direction is fixed to form a set of reference points to correct the angular error of the micromotor scanning. This allows the control device to obtain a three-dimensional contour of a small area. The three-dimensional contours measured at different insertion points are stitched together through three-dimensional image stitching calculations to obtain the three-dimensional information of the object under test.

[0021] In some embodiments of this disclosure, the first measuring unit includes a first charge-coupled element and a first receiving lens; the second measuring unit includes a second charge-coupled element and a second receiving lens.

[0022] In some embodiments of this disclosure, the range of the first measuring unit is greater than the range of the second measuring unit.

[0023] In some embodiments of this disclosure, the measurement accuracy of the first measuring unit is lower than that of the second measuring unit.

[0024] In some embodiments of this disclosure, the reading rate of the first measurement unit is greater than the reading rate of the second measurement unit.

[0025] In some embodiments of this disclosure, the surface inspection device further includes a temperature protection device encasing the laser measuring head, wherein:

[0026] Temperature protection device is used to ensure that the temperature of the test environment is within a predetermined temperature range.

[0027] In some embodiments of this disclosure, the surface inspection equipment further includes a spraying device and a coating thickness calibration device, wherein:

[0028] A spraying device for forming a surface coating on a non-cooperative object when the object to be tested is not a cooperative object.

[0029] The coating thickness calibration device is used to calibrate the thickness of the material to be sprayed before spraying. After the surface contour measurement of the object to be measured is completed, the measurement results are corrected according to the coating thickness.

[0030] According to another aspect of this disclosure, a surface inspection method is provided, comprising:

[0031] The first measurement unit of the surface inspection equipment performs a coarse-precision rapid measurement of the object under test to obtain coarse-precision data of the object's outer contour.

[0032] The control device of the surface inspection equipment determines the measurement stroke and steps of the laser measuring head based on the coarse accuracy data;

[0033] The second measuring unit of the surface inspection equipment completes the high-precision surface measurement of the object to be measured, wherein the surface inspection equipment is the surface inspection equipment as described in any of the above embodiments.

[0034] In some embodiments of this disclosure, the surface inspection method further includes:

[0035] A focusing lens focuses the laser beam emitted by the laser.

[0036] Diffractive optical elements split the laser beam, so that the split laser beam is incident on the surface of the object to be measured.

[0037] The first and second measurement units image the light scattered and returned from the surface of the object under test to determine the distance between the laser and the surface of the object under test.

[0038] In some embodiments of this disclosure, the surface inspection method further includes:

[0039] The control device controls the motion controller to drive the motion actuator, thereby enabling the laser measuring head to move.

[0040] In some embodiments of this disclosure, the surface inspection method further includes:

[0041] The first measuring unit quickly detects the surface of the object to be measured and feeds back the detection data to the control device;

[0042] The control device processes the detection data to obtain the distance between the laser head and the surface of the object to be measured, as well as the shape of the object.

[0043] The control device determines whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance;

[0044] When the distance between the laser head and the surface of the object under test is less than or equal to a predetermined distance in any direction, the control device controls the motion actuator to stop moving in that direction via the motion controller.

[0045] When the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the control device controls the motion actuator to continue moving in that direction through the motion controller to determine the optimal measurement stroke.

[0046] In some embodiments of this disclosure, the first measuring unit and the second measuring unit operate simultaneously during the measurement stroke.

[0047] In some embodiments of this disclosure, the surface inspection method further includes:

[0048] The diffractive optical element splits the laser beam into two mutually perpendicular beam arrays. The beam array in the first direction is scanned by a scanning device driven by a micromotor, while the beam array in the second direction is fixed to form a set of reference points to correct the angular error of the micromotor scanning.

[0049] The control device obtains the three-dimensional contour of a small area, and stitches together the three-dimensional contours measured at different insertion points through three-dimensional image stitching calculation to obtain the three-dimensional information of the object under test.

[0050] In some embodiments of this disclosure, the surface inspection method further includes:

[0051] The temperature protection device ensures that the temperature of the test environment is within the predetermined temperature range.

[0052] In some embodiments of this disclosure, the surface inspection method further includes:

[0053] The spraying device forms a surface coating on the object being tested when the object is a non-cooperative object.

[0054] The coating thickness calibration device calibrates the thickness of the sprayed material before spraying. After completing the surface contour measurement of the object to be measured, the measurement results are corrected according to the coating thickness.

[0055] According to another aspect of this disclosure, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores computer instructions that, when executed by a processor, implement the surface detection method as described in any of the above embodiments.

[0056] This disclosure enables real-time, automatic planning of irregular detection paths and high-precision, non-contact measurement of objects within confined spaces. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 These are schematic diagrams of some embodiments of the surface inspection equipment disclosed herein.

[0059] Figure 2 This is a schematic diagram of some embodiments of the dual-mode, dual-range laser measurement device disclosed herein.

[0060] Figure 3 This is a schematic diagram of some other embodiments of the dual-mode, dual-range laser measurement device disclosed herein.

[0061] Figure 4 This is a schematic diagram illustrating some embodiments of the motion mode of the motion actuator of this disclosure.

[0062] Figure 5 This is a schematic diagram of some embodiments of the surface inspection method disclosed herein.

[0063] Figure 6 These are schematic diagrams of other embodiments of the surface inspection method disclosed herein. Detailed Implementation

[0064] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0065] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0066] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0067] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0068] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0069] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0070] Air intake icing and ice impact are serious safety considerations for aero-engines, and icing-related flight accidents occur every year. Civil aircraft engines are extremely sensitive to icing, which can easily lead to dangerous situations. Once the engine intake system is iced, it alters the aerodynamic characteristics of the intake system, increases flow resistance, and causes uneven airflow distribution. This can result in airflow distortion, affecting engine stability, and in severe cases, engine shutdown with fatal consequences. If the engine intake system is iced, the anti-icing system may activate late or fail, allowing melted or centrifugally dislodged ice to be sucked into the engine, causing serious foreign object damage. Investigations into engine icing accidents have revealed that icing often causes insufficient engine aerodynamic stability and in-flight automatic engine shutdown, seriously threatening flight safety. Engine airworthiness certification requires testing and verification of icing and ice impact, and determining the thickness and shape of ice on the blade surface is a crucial prerequisite for conducting airworthiness verification. Due to the transparency of ice, lasers and light can pass directly through the parts without reflecting onto the testing equipment, and ice shape testing has high requirements for the testing environment and temperature (low temperature). There is still a significant demand in the engine and automotive industries for surface profile inspection at high temperatures.

[0071] Therefore, how to perform surface inspection on substances like ice under harsh testing environments of high and low temperatures, and how to perform non-contact measurements involving irregular and narrow testing paths are currently urgent problems that need to be solved.

[0072] In view of at least one of the above technical problems, this disclosure provides a surface inspection device and a surface inspection method, which will be described below through embodiments.

[0073] Figure 1 These are schematic diagrams of some embodiments of the surface inspection equipment disclosed herein. For example... Figure 1 As shown, the surface inspection equipment disclosed herein may include a laser measuring head 1 and a control device 2. The laser measuring head 1 may be a dual-mode, dual-range laser measuring device, which can realize real-time and automatic planning of the detection path and the surface inspection of the target object.

[0074] Figure 2 These are schematic diagrams illustrating some embodiments of the dual-mode, dual-range laser measurement device disclosed herein. Figure 2 As shown, the dual-mode, dual-range laser measurement device may include a first measurement unit 11 and a second measurement unit 12, wherein:

[0075] The first measurement unit 11 is used to perform coarse-precision rapid measurement of the object to be measured, and obtain coarse-precision data of the outline of the object to be measured.

[0076] The control device 2 is used to determine the measurement stroke and steps of the laser measuring head 1 based on coarse-precision data, calculate the optimal measurement route, and avoid possible interference and contact risks in the XYZ directions.

[0077] In some embodiments of this disclosure, the control device 2 can be implemented as a computer program control and data processing system.

[0078] The second measurement unit 12 is used to perform high-precision surface measurement of the object to be measured.

[0079] In the above embodiments of this disclosure, the first measurement unit and the second measurement unit are combined to complete high-speed, high-precision precision measurement and obtain high-precision three-dimensional contour data.

[0080] In some embodiments of this disclosure, such as Figure 2 As shown, the first measurement unit 11 may include a first CCD (Charge-coupled Device) 111 and a first receiving lens 112; the second measurement unit 12 includes a second charge-coupled device 121 and a second receiving lens 122.

[0081] In some embodiments of this disclosure, such as Figure 2 As shown, the angle between the optical axis of the first measuring unit 11 and the laser 13 is ψ1, and the angle between the optical axis of the second measuring unit 12 and the laser 13 is ψ2.

[0082] In some embodiments of this disclosure, the range of the first measuring unit 11 is greater than the range of the second measuring unit 12.

[0083] In some embodiments of this disclosure, the measurement accuracy of the first measurement unit 11 is lower than that of the second measurement unit 12.

[0084] In some embodiments of this disclosure, the reading rate of the first measurement unit 11 is greater than the reading rate of the second measurement unit 12.

[0085] In some embodiments of this disclosure, Table 1 provides the parameters of the dual-mode, dual-range laser measurement device of this disclosure.

[0086] Table 1

[0087] Module accuracy range rate First Measurement Unit ≥3μm ≥20mm ≥1000 frames / second Second measurement unit ≤3μm ≤20mm ≤300 frames / second

[0088] This disclosed dual-mode, dual-range laser measuring device is a laser three-dimensional contour precision measuring device. This laser three-dimensional contour precision measuring device simultaneously employs two measuring units: coarse measurement (large range) and precision measurement (small range). To achieve both coarse and fine modes of measurement within the same laser ranging module, the laser measuring head integrates two sets of receiving devices, using a dual CCD camera receiving configuration. The shorter focal length receiver is a coarse-precision, large-range receiver used for rapid, coarse measurement of the object being measured, while the longer focal length receiver is a high-precision, small-range receiver used for high-precision measurement of the object being measured.

[0089] like Figure 2 As shown, this disclosure achieves measurements in two ranges and two modes using triangulation, where the laser is a type of stimulated emission light amplification source. Triangulation refers to a method of determining the horizontal position (coordinates) of each triangle's vertex by arranging a series of continuous triangles on the ground and measuring angles. The name "triangulation" derives from the fact that the laser emitter, detection surface, and CCD camera require a triangular structure for installation; therefore, this ranging system is called triangulation.

[0090] Figure 3 These are schematic diagrams illustrating other embodiments of the dual-mode, dual-range laser measurement device disclosed herein. For example... Figure 2 and Figure 3 As shown, the dual-mode, dual-range laser measurement device of this disclosure may further include a laser 13, a focusing lens 14, and at least one DOE (Diffractive Optical Elements) diffractive optical element 15, wherein:

[0091] The focusing lens 14 is used to focus the laser beam emitted by the laser 13.

[0092] The diffractive optical element 15 is used to split the laser beam so that the split laser beam is incident on the surface of the object to be measured.

[0093] In some embodiments of this disclosure, the diffractive optical element 15 may be a diffraction grating, wherein the diffraction grating is an optical device composed of dense, equally spaced parallel scribed lines.

[0094] The first measurement unit 11 and the second measurement unit 12 are used to image the light scattered and returned from the surface of the object under test, and to determine the distance between the laser 13 and the surface of the object under test.

[0095] Since the measurement speed of a laser measuring device mainly depends on the CCD's readout speed, which is primarily limited by the readout rate of a high-resolution CCD, typically the readout rate of a high-precision receiving CCD is around 300 frames per second, while the readout rate of a low-precision receiving CCD exceeds 1000 frames per second. Simply increasing the CCD readout rate can improve the measurement speed, but this method only increases the single-point data rate and has limited contribution to improving the actual measurement speed of the object under test. To further and effectively improve the measurement speed, this disclosure presents a dual-mode, dual-range laser measuring device that employs multi-beam laser triangulation technology to measure the distance to the surface of the object under test. Multiple beams with precise angles are prepared using diffraction elements (DOEs) to achieve multi-point ranging, and the angle between each point and the receiving CCD is accurately determined, ensuring high-precision measurement while maintaining high spatial resolution between measurement points.

[0096] This disclosure utilizes multi-beam measurement, linearly increasing the number of effective measurement points from the same frame of data. By designing the beams in a one-dimensional linear arrangement, it achieves the same effect as a line laser. Furthermore, because the points are discrete, spatial resolution is significantly improved, thereby enhancing measurement accuracy. When uniform distribution of measurement points is required, fiber optic arrays can be developed to output multiple beams, resulting in parallel beams that ensure the spacing between points illuminating the surface of the object remains constant regardless of surface distance. The coarse and fine measurement units can utilize one or more DOEs. Using multiple DOEs allows for different beam-splitting strategies, further improving detection speed and accuracy.

[0097] Triangulation involves focusing a laser beam emitted from a laser onto the surface of an object to be measured. The light scattered back from the object's surface is then imaged onto a CCD image sensor by an imaging lens. This method allows the determination of the distance between the laser and the object's surface. This disclosure, based on triangulation, inserts a DOE (Device Array of Optical Components) element between the focusing lens and the object to split the laser beam, thereby improving the detection rate.

[0098] This disclosure uses a short-focal-length CCD for the large-range unit and a longer-focal-length CCD for the small-range unit. For example, the large-range receiving lens can be a 1:5 lens, amplifying the range while maintaining a small angle. The small-range receiving uses a high-resolution lens, receiving images with 1:1 high precision. The CCD can be a model with 4096*1024 pixels or larger. The CCD pixel size of the low-precision, large-range measurement unit is ≥3μm, for example, 50-100μm, while the CCD pixel size of the high-precision, small-range measurement unit is ≤3μm. The settings of the dual-mode laser measurement system can be found in Table 1.

[0099] In some embodiments of this disclosure, such as Figure 1As shown, the surface inspection equipment disclosed herein may further include a motion actuator 3 and a motion controller 4, wherein:

[0100] The laser measuring head 1 is mounted on the motion actuator 3.

[0101] The control device 2 controls the motion controller 4 to drive the motion actuator 3, thereby realizing the movement of the laser measuring head 1.

[0102] In some embodiments of this disclosure, the first measuring unit 11 can be used to quickly detect the surface of the object to be measured and feed back the detection data to the control device 2;

[0103] The control device 2 can be used to process the detection data to obtain the distance between the laser head and the surface of the object to be measured and the shape of the object; determine whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance; if the distance between the laser head and the surface of the object to be measured in any direction is less than or equal to the predetermined distance, the motion controller 4 controls the motion actuator 3 to stop moving in that direction; if the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the motion controller 4 controls the motion actuator 3 to continue moving in that direction, and determine the optimal measurement stroke.

[0104] In some embodiments of this disclosure, the control device 2 can be used to obtain the distance between the laser head and the surface of the object being measured, as well as the shape of the object. Based on the distance between the laser head and the surface of the object being measured, in any of the x, y, and z directions (a total of 6 directions: +x, -x, +y, -y, +z, -z), when the distance between the laser head and the surface of the object being measured is ≤ a set value (e.g., ≤ 1mm), the motion controller controls and ensures that the motion actuator stops moving in this direction. When the distance between the measured surface and the measuring head in the measured direction is ≤ 1mm, the probe stops advancing in the measured direction, the motion actuator performs micro-motion, and the large-range measurement unit simultaneously detects the direction of micro-motion. When the detection result (distance to the object being measured) is ≥ a set value (e.g., > 1mm), the motion actuator continues moving in that direction. Through repeated iterations of the above process, the optimal detection path can ultimately be obtained.

[0105] In some embodiments of this disclosure, during the detection process, the first measurement unit 11 and the second measurement unit 12 operate simultaneously. The first measurement unit 11 can obtain the detection results more quickly and feed them back to the control device in real time, while the second measurement unit 12 performs high-precision surface detection. Ultimately, through the configuration of the CCD, receiving lens, and angle, dual-mode, dual-range testing is achieved, ensuring real-time planning of the detection path and simultaneously performing rapid and high-precision detection of the measured surface. During the detection process, manual stopping, control, and planning of the measurement path and steps are not excluded.

[0106] Figure 4This is a schematic diagram illustrating some embodiments of the motion mechanism of the motion actuator disclosed herein. For example... Figure 4 As shown, the motion actuator 3 of this disclosure may include a flexible robotic arm, a micromotor, and a rotary table 31, wherein:

[0107] The diffractive optical element 15 is used to split the laser beam into two mutually perpendicular beam arrays. The beam array in the first direction is scanned by a scanning device driven by a micromotor, while the beam array in the second direction is fixed to form a set of reference points to correct the angular error of the micromotor scanning. This allows the control device 2 to obtain a three-dimensional contour of a small area. The three-dimensional contours measured at different insertion points are stitched together by three-dimensional image stitching calculation to obtain the three-dimensional information of the object under test.

[0108] In some embodiments of this disclosure, such as Figure 4 As shown, the laser transmission fiber transmits laser light to the measuring head, which then splits the laser beam onto the DOE element, forming two mutually perpendicular beam arrays. The Y-direction beam array is scanned by a scanning device driven by a micromotor, while the X-direction beam array remains stationary, forming a set of reference points to correct angular errors in the micromotor's scanning. The above embodiments of this disclosure can obtain a three-dimensional contour of a small area. By performing three-dimensional image stitching calculations, the three-dimensional contours measured at different insertion points are stitched together one by one to finally obtain the three-dimensional information of the object under test.

[0109] Figure 3 In this embodiment, the laser emits continuous light, which is focused by a focusing lens, and the focused light is split by a diffraction element (DOE) (see...). Figure 3 The light is shone onto the surface of the target object. Figure 3 The components within the dashed box are integrated in Figure 4 On the probe (laser measuring head 1) in the middle, such as Figure 3 As shown, the laser measuring head 1 may include: a laser 13, a focusing lens 14, two DOEs 15, a first measuring unit 11, and a second measuring unit 12.

[0110] Figure 2 This is a schematic diagram of the dual-mode laser head disclosed in this invention. Figure 2 As shown, the first measurement unit 11 and the second measurement unit 12 are two sets of CCD cameras and lens assemblies. The first measurement unit 11 includes a first CCD 111 (reading rate 1000 frames / second) and a first receiving lens 112. The first measurement unit 11 is a coarse measurement unit. The second measurement unit 12 includes a second charge-coupled device 121 (reading rate 300 frames / second) and a second receiving lens 122. The second measurement unit 12 is a precision measurement unit. The first measurement unit 11 and the second measurement unit 12 together constitute a dual-mode laser measurement system.

[0111] In some embodiments of this disclosure, such as Figure 4 As shown, the surface inspection equipment disclosed herein may also include an endoscope transmission fiber and a laser transmission fiber.

[0112] In some embodiments of this disclosure, the laser measuring head is mounted on a flexible motion actuator.

[0113] In some embodiments of this disclosure, the control device can be used to control the motion controller to drive the motion actuator, and realize the high-precision movement of the laser measuring head in the xyz directions by means of a rotary table and micro motor. The motion control mechanism is equipped with a detection path recording function, which can record the detection path after detection and can be directly recalled for the next use.

[0114] In some embodiments of this disclosure, such as Figure 1 As shown, the surface inspection equipment may further include a light source system 6, wherein:

[0115] Light source system 6 is used to activate the light source system in a timely manner during the detection process to ensure that the brightness of the area to be inspected meets the detection requirements.

[0116] In some embodiments of this disclosure, the light source system 6 may use LEDs or other cold light systems, etc.

[0117] In some embodiments of this disclosure, such as Figure 1 As shown, the surface inspection equipment may further include a temperature protection device 5 that surrounds the laser measuring head 1 and the light source system 6, wherein:

[0118] Temperature protection device 5 is used to ensure that the temperature of the test environment is within a predetermined temperature range.

[0119] The embodiments of this disclosure for high-temperature temperature detection include wrapping a temperature protection device around the laser measuring head to ensure detection results in both low-temperature (minimum detection temperature is -30°C) and high-temperature (maximum detection temperature is 100°C) testing environments.

[0120] In some embodiments of this disclosure, the temperature protection device 5 may use an aerogel protective layer.

[0121] In some embodiments of this disclosure, such as Figure 1 As shown, the surface inspection equipment may further include a display system 7, wherein:

[0122] Display system 7 is used to display the measurement results output by control device 2.

[0123] In some embodiments of this disclosure, the surface inspection equipment may further include a spraying device and a coating thickness calibration device, wherein:

[0124] A spraying device for forming a surface coating on a non-cooperative object.

[0125] In some embodiments of this disclosure, the spraying apparatus is used to form a surface coating on the object being tested when the surface profile of the object being tested is a non-cooperative object (i.e., a diffuse reflector) by using a developer, powder spraying, moiré, speckle, etc.

[0126] In some embodiments of this disclosure, the thickness of the surface coating is ≤100μm to ensure that the laser does not penetrate the surface of the object being tested.

[0127] The coating thickness calibration device is used to calibrate the thickness of the material to be sprayed before spraying. After the surface contour measurement of the object to be measured is completed, the measurement results are corrected according to the coating thickness.

[0128] Based on the surface inspection equipment provided in the above embodiments of this disclosure, real-time and automatic planning of irregular inspection paths can be realized, meeting the stringent requirements of the test environment (high temperature, low temperature) and the object under test (non-cooperative target: i.e. diffuse reflector, such as ice), and finally completing high-precision, non-contact measurement of the object under test in a narrow space.

[0129] The above embodiments of this disclosure employ a dual-mode high-precision laser measurement device based on an endoscope-guided optical fiber, which can solve the application requirements of narrow measurement paths and environments, and automatic planning of measurement strokes, ultimately achieving high-precision non-contact measurement of the object being measured.

[0130] Figure 5 This is a schematic diagram of some embodiments of the surface inspection method of this disclosure. Preferably, this embodiment can be performed by the surface inspection equipment of this disclosure (e.g., the one disclosed herein). Figures 1-4 The surface inspection device described in any embodiment is used for execution. The method may include steps 51-53, wherein:

[0131] Step 51: The first measuring unit 11 of the surface inspection equipment is used to perform a coarse-precision rapid measurement of the object to be measured to obtain coarse-precision data of the outline of the object to be measured.

[0132] Step 52: The control device 2 of the surface inspection equipment determines the measurement stroke and steps of the laser measuring head 1 based on the coarse accuracy data.

[0133] Step 53: The second measuring unit 12 of the surface inspection device is used to complete the high-precision surface measurement of the object to be measured, wherein the surface inspection device is the surface inspection device as described in any of the above embodiments.

[0134] In some embodiments of this disclosure, the surface detection method may further include: focusing lens 14 focusing the laser beam emitted by laser 13; diffractive optical element 15 splitting the laser beam so that the split laser beam is incident on the surface of the object to be measured; and first measurement unit 11 and second measurement unit 12 imaging the light scattered back from the surface of the object to be measured to determine the distance between laser 13 and the surface of the object to be measured.

[0135] In some embodiments of this disclosure, the surface inspection method may further include: the control device 2 controls the motion controller 4 to drive the motion actuator 3 to realize the movement of the laser measuring head 1.

[0136] In some embodiments of this disclosure, the surface detection method may further include: a first measuring unit 11 rapidly detecting the surface of the object to be measured and feeding back the detection data to the control device 2; the control device 2 processing the detection data to obtain the distance between the laser head and the surface of the object to be measured and the surface of the object to be measured; the control device 2 determining whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance; if the distance between the laser head and the surface of the object to be measured in any direction is less than or equal to the predetermined distance, the control device 2 controlling the motion actuator 3 to stop moving in that direction via the motion controller 4; if the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the control device 2 controlling the motion actuator 3 to continue moving in that direction via the motion controller 4, thereby determining the optimal measurement stroke.

[0137] In some embodiments of this disclosure, the first measuring unit 11 and the second measuring unit 12 operate simultaneously during the measurement process.

[0138] In some embodiments of this disclosure, the surface detection method may further include: the diffractive optical element 15 splits the laser beam to form two mutually perpendicular beam arrays, wherein the beam array in the first direction is scanned by a scanning device driven by a micromotor, and the beam array in the second direction is fixed to form a set of reference points for correcting the angular error of the micromotor scanning; the control device 2 obtains the three-dimensional contour of a small area, and stitches the three-dimensional contours measured at different insertion points together by three-dimensional image stitching calculation to obtain the three-dimensional information of the object to be measured.

[0139] In some embodiments of this disclosure, the surface inspection method may further include: a temperature protection device 5 to ensure that the temperature of the test environment is within a predetermined temperature range.

[0140] In some embodiments of this disclosure, the surface detection method may further include: a spraying device forming a surface coating on the object to be measured when the object to be measured is a non-cooperative object; a coating thickness calibration device calibrating the thickness of the sprayed material before spraying, and correcting the measurement result based on the coating thickness after completing the surface contour measurement of the object to be measured.

[0141] Figure 6 The diagram illustrates other embodiments of the surface inspection method of this disclosure. Preferably, this embodiment can be performed using the surface inspection equipment of this disclosure (e.g., the one disclosed herein). Figures 1-4 The surface inspection device described in any embodiment is used for execution. The method may include steps 61-65, wherein:

[0142] Step 61: Calibrate the surface inspection equipment of this disclosure.

[0143] In some embodiments of this disclosure, step 61 may include: simultaneously measuring the depth / distance of the calibration target using the measuring device of this disclosure and another testing device (such as an interferometric rangefinder, a coordinate measuring machine, etc.; in this embodiment, an interferometric rangefinder is used); controlling the laser measuring head to place the calibration target on the focal plane so that multiple clear bright spots can be formed on the surface of the calibration target; adjusting and fixing the position and angle of the CCD camera and lens so that the CCD camera can receive clear images of all the bright spots; recording the measurement data of the interferometric rangefinder and the spot imaging information of the triangulation system; using the spot center position information of each beam as the input variable of the system model; and using the corresponding interferometric rangefinder measurement data as the expected output value of the system to complete the triangulation calibration of each beam of light.

[0144] Step 62: During the detection process, the first measurement unit 11 and the second measurement unit 12 work simultaneously. The detection results of the two measurement units will be fed back to the control device in real time. Since the detection rate of the first measurement unit 11 (first CCD 111 and first receiving lens 112) is greater than that of the precision measurement system (second CCD 121 and second receiving lens 122), the control device can obtain the detection results of the coarse measurement system more quickly and display them through the display system.

[0145] Step 63: Obtain the rough measurement result of the surface of the object under test through the first CCD 111 and the first receiving lens 112. Based on this result, the control device automatically plans the measurement path and steps: When the distance between the laser head and the surface of the object under test is ≤10mm in any measurement direction, the laser head is stopped from moving forward / moving in this direction by the motion actuator. The rotary table rotates 360° and drives the laser measuring head in three directions by the motion actuator.

[0146] Step 64: When the laser head moves to the required detection position, the precise measurement result of the surface of the object being measured can be obtained through the second CCD 121 and the second receiving lens 122.

[0147] Step 65: During the measurement process, the measurement path and steps can be adjusted at any time according to the measurement and display results and user instructions. For example, the motion actuator can be controlled according to user instructions to ensure coarse and fine measurements are performed at the required detection positions.

[0148] Based on the surface inspection method provided in the above embodiments of this disclosure, real-time and automatic planning of irregular inspection paths can be achieved, meeting the stringent requirements of the test environment (high temperature, low temperature) and the object under test (non-cooperative target: i.e. diffuse reflector, such as ice), and finally completing high-precision, non-contact measurement of the object under test in a narrow space.

[0149] The above embodiments of this disclosure employ a dual-mode high-precision laser measurement device based on an endoscope-guided optical fiber, which can solve the application requirements of narrow measurement paths and environments, and automatic planning of measurement strokes, ultimately achieving high-precision non-contact measurement of the object being measured.

[0150] According to another aspect of this disclosure, a non-transitory computer-readable storage medium is provided, wherein the non-transitory computer-readable storage medium stores computer instructions that, when executed by a processor, implement any of the embodiments described above (e.g., Figure 5 or Figure 6 The surface inspection method described in the embodiment)

[0151] Based on the non-transient computer-readable storage medium provided in the above embodiments of this disclosure, real-time and automatic planning of irregular detection paths can be realized, meeting the stringent requirements of the test environment (high temperature, low temperature) and the object under test (non-cooperative target: i.e. diffuse reflector, such as ice), and finally completing high-precision, non-contact measurement of the object under test in a confined space.

[0152] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0153] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0154] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0155] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0156] The control device described above can be implemented as a general-purpose processor, programmable logic controller (PLC), digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component or any suitable combination thereof for performing the functions described in this application.

[0157] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0158] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware, or by a program instructing the relevant hardware to implement them. The program can be stored in a non-transitory computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0159] The description in this disclosure is provided for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the disclosure to its forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of this disclosure and to enable those skilled in the art to understand this disclosure and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A surface inspection device, characterized in that, The device includes a laser measuring head, a control device, a motion actuator, and a motion controller. The laser measuring head is a dual-mode, dual-range laser measuring device, which includes a diffractive optical element, a first measuring unit, and a second measuring unit. The motion actuator further includes a micromotor. The first measurement unit is used to perform coarse-precision rapid measurement of the object to be measured, and obtain coarse-precision data of the object's outline. The control device is used to determine the measurement stroke and steps of the laser measuring head based on coarse-precision data; The second measurement unit is used to perform high-precision surface measurement of the object under test. The laser measuring head is mounted on the motion actuator; The control device is also used to control the motion controller to drive the motion actuator, thereby enabling the movement of the laser measuring head; The first measuring unit is also used to quickly detect the surface of the object to be measured and to feed back the detection data to the control device. The control device is also used to process the detection data to obtain the distance between the laser head and the surface of the object to be measured, as well as the shape of the object; to determine whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance; if the distance between the laser head and the surface of the object to be measured in any direction is less than or equal to the predetermined distance, the motion controller controls the motion actuator to stop moving in that direction; if the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the motion controller controls the motion actuator to continue moving in that direction, thus determining the optimal measurement stroke. A diffractive optical element is used to split a laser beam into two mutually perpendicular beam arrays. The beam array in the first direction is scanned by a scanning device driven by a micromotor, while the beam array in the second direction is fixed to form a set of reference points to correct the angular error of the micromotor scanning. This allows the control device to obtain a three-dimensional contour of a small area. The three-dimensional contours measured at different insertion points are stitched together through three-dimensional image stitching calculations to obtain the three-dimensional information of the object under test.

2. The surface inspection equipment according to claim 1, characterized in that, The dual-mode, dual-range laser measurement device further includes a laser, a focusing lens, and at least one diffractive optical element, wherein: A focusing lens is used to focus the laser beam emitted by a laser. Diffractive optical elements are used to split a laser beam so that the split laser beam is incident on the surface of the object to be measured. The first and second measurement units are used to image the light scattered and returned from the surface of the object under test, and to determine the distance between the laser and the surface of the object under test.

3. The surface inspection equipment according to claim 1 or 2, characterized in that, During the measurement process, the first and second measurement units work simultaneously.

4. The surface inspection equipment according to claim 1 or 2, characterized in that, The first measurement unit includes a first charge-coupled element and a first receiving lens; the second measurement unit includes a second charge-coupled element and a second receiving lens.

5. The surface inspection equipment according to claim 1 or 2, characterized in that, The range of the first measuring unit is greater than the range of the second measuring unit; And / or, The measurement accuracy of the first measurement unit is lower than that of the second measurement unit; And / or, The reading rate of the first measurement unit is greater than that of the second measurement unit.

6. The surface inspection equipment according to claim 1 or 2, characterized in that, It also includes a temperature protection device wrapped around the laser measuring head, wherein: Temperature protection device is used to ensure that the temperature of the test environment is within a predetermined temperature range.

7. The surface inspection equipment according to claim 1 or 2, characterized in that, It also includes a spraying device and a coating thickness calibration device, wherein: A spraying device for forming a surface coating on a non-cooperative object when the object to be tested is not a cooperative object. The coating thickness calibration device is used to calibrate the thickness of the material to be sprayed before spraying. After the surface contour measurement of the object to be measured is completed, the measurement results are corrected according to the coating thickness.

8. A surface inspection method, characterized in that, include: The first measurement unit of the surface inspection equipment performs a coarse-precision rapid measurement of the object under test to obtain coarse-precision data of the object's outer contour. The control device of the surface inspection equipment determines the measurement stroke and steps of the laser measuring head based on the coarse accuracy data; The second measuring unit of the surface inspection equipment completes the high-precision surface measurement of the object to be measured, wherein the surface inspection equipment is the surface inspection equipment as described in any one of claims 1-7; The control device controls the motion controller to drive the motion actuator, thereby enabling the movement of the laser measuring head; The first measuring unit quickly detects the surface of the object to be measured and feeds back the detection data to the control device; The control device processes the detection data to obtain the distance between the laser head and the surface of the object to be measured, as well as the shape of the object. The control device determines whether the distance between the laser head and the surface of the object to be measured is greater than a predetermined distance; When the distance between the laser head and the surface of the object under test is less than or equal to a predetermined distance in any direction, the control device controls the motion actuator to stop moving in that direction via the motion controller. When the distance between the laser head and the surface of the object to be measured is greater than the predetermined distance, the control device controls the motion actuator to continue moving in that direction through the motion controller to determine the optimal measurement stroke; The diffractive optical element splits the laser beam into two mutually perpendicular beam arrays. The beam array in the first direction is scanned by a scanning device driven by a micromotor, while the beam array in the second direction is fixed to form a set of reference points to correct the angular error of the micromotor scanning. The control device obtains the three-dimensional contour of a small area, and stitches together the three-dimensional contours measured at different insertion points through three-dimensional image stitching calculation to obtain the three-dimensional information of the object under test.

9. The surface inspection method according to claim 8, characterized in that, Also includes: A focusing lens focuses the laser beam emitted by the laser. Diffractive optical elements split the laser beam, so that the split laser beam is incident on the surface of the object to be measured. The first and second measurement units image the light scattered and returned from the surface of the object under test to determine the distance between the laser and the surface of the object under test.

10. The surface inspection method according to claim 8 or 9, characterized in that, During the measurement process, the first and second measurement units work simultaneously.

11. The surface inspection method according to claim 8 or 9, characterized in that, Also includes: The temperature protection device ensures that the temperature of the test environment is within the predetermined temperature range.

12. The surface inspection method according to claim 8 or 9, characterized in that, Also includes: The spraying device forms a surface coating on the object being tested when the object is a non-cooperative object. The coating thickness calibration device calibrates the thickness of the sprayed material before spraying. After completing the surface contour measurement of the object to be measured, the measurement results are corrected according to the coating thickness.

13. A non-transitory computer-readable storage medium, characterized in that, The non-transitory computer-readable storage medium stores computer instructions that, when executed by a processor, implement the surface detection method as described in any one of claims 8-12.

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