Acquisition method, system and equipment suitable for stroke motion curve of slender piece

Abstract

The invention discloses a method, a system and equipment suitable for acquiring a stroke motion curve of a slender part, and the method comprises the steps: extracting the pixel length between any two groups of calibration identifiers from a moving part calibration image, and obtaining a proportional relation between the pixel length and an actual distance; a plurality of frames of images of the whole travel of the moving part are obtained in real time, positioning feature points are extracted from feature areas in each frame of image, and pixel coordinate values of the positioning feature points are obtained; and obtaining the pixel coordinate value variation of the same positioning feature point in the two adjacent frames of images in the image by taking the pixel as the unit according to the time sequence, calculating the actual movement distance of the moving part according to the proportional relation, and calculating the speed at the corresponding moment in combination with the interval time obtained by the two adjacent frames of images. According to the method, the cross-like identification is adopted, the image processing technology is combined, and under the conditions that the structure of the driving line is not changed and the flow field of the driving line is not interfered, the identification manufacturing requirement is lowered, and high precision is obtained.

Description

Technical Field

[0001] The present application relates to the technical field of slender member stroke measurement, and specifically to a method, system and device for obtaining a slender member stroke motion curve, and is particularly suitable for carrying out stroke measurement of a reactor control rod drive line rod drop test. Background Art

[0002] The control rod drive wire is the only moving part in the reactor. When the reactor motion parameters exceed the limit and may endanger the core and the primary circuit pressure boundary, the control rods need to be quickly dropped through automatic or manual control to ensure the safety of the reactor and the integrity of the drive wire structures. Therefore, it is necessary to carry out the evaluation of the control rod drive wire drop characteristics, and achieve the optimal configuration of the wires and buffer components by obtaining the refined rod drop stroke, so as to guide the reactor structure design and finalization.

[0003] The rod drop stroke of traditional drive lines is mostly obtained by the indication function of the rod position detector to obtain the rod drop displacement curve, and then the velocity curve and acceleration curve are obtained by derivation. However, due to the short rod drop time and fast speed, and the rod position detector has poor time accuracy due to its own characteristics, the obtained stroke accuracy is not high. At the end of the stroke, it enters its indication blind area and its accuracy cannot be guaranteed at all.

[0004] In addition, the existing methods also propose: (1) In the AP1000 driving line drop experiment, the light and dark conditions formed by the driving rod tooth groove in the camera image are used as positioning features, and the driving rod displacement is obtained through image processing; (2) The applicant proposed that by making horizontal lines on the driving rod, the difference between the pixels of the lines and the background in the image obtained by the high-speed camera is used to extract features and obtain the driving rod displacement. Although the feature extraction methods and image processing techniques of the two are different, they both use the horizontal line method. The accuracy of the processed curve will be subject to the production method and effect of the lines. Under the high magnification effect of the high-speed camera, the contrast between the lines and the background is weak, and the positioning accuracy of the lines will be significantly reduced. In addition, the lines must have a certain width, which increases the difficulty of positioning. It is difficult to obtain high-quality data and the accuracy is not easy to improve. Summary of the invention

[0005] In order to solve the problems of high requirements for line production, limited accuracy, and great positioning difficulty in the existing method of using horizontal line engraving, the present application proposes a method, system and equipment suitable for obtaining the travel motion curve of slender parts. The present application adopts a cross-like mark, and combines high-speed camera technology and image processing technology to quickly and accurately obtain the drive line drop rod and various slender parts travel motion curves, and reduces the mark production requirements and obtains higher accuracy without changing the drive line structure and interfering with the drive line flow field.

[0006] This application is implemented through the following technical solutions:

[0007] A method for obtaining a travel motion curve of a slender member, the method comprising:

[0008] Extracting the pixel length between any two groups of the calibration marks from the moving part calibration image, and obtaining the proportional relationship between the pixel length and the actual distance; wherein the moving part calibration image is an image including at least three groups of calibration marks pre-made on the moving part;

[0009] Acquire several frames of images of the entire stroke of the moving component in real time, extract positioning feature points from the feature area in each frame of the image, and obtain pixel coordinate values ​​of the positioning feature points; wherein the feature area is determined by a feature mark pre-made on the corresponding visible stroke area of ​​the moving component;

[0010] The pixel coordinate value variation of the same positioning feature point in two adjacent frames of images is obtained in time sequence in units of pixels, so as to determine the pixel displacement of the positioning feature point, and the actual movement distance of the moving part is calculated according to the proportional relationship; the speed at the corresponding moment is calculated according to the actual movement distance of the moving part and the interval time between the two adjacent frames of images;

[0011] Repeat the previous step to obtain a curve of the entire stroke speed of the moving part changing with time;

[0012] Among them, the calibration mark and the characteristic mark both adopt a cross-like mark.

[0013] In some embodiments, the acquisition method further comprises:

[0014] According to the curve of the speed variation over time of the entire stroke of the moving component, the curve of the displacement variation over time is obtained by integration, and the curve of the acceleration variation over time is obtained by differentiation.

[0015] In some implementations, the production requirements for the calibration mark and the feature mark are:

[0016] The size, line width and spacing of the multiple cross-like marks should be maintained, and the intersection points of the cross-like marks along the direction of movement should be on the same straight line, and the following conditions should be met: under high magnification, the mark color should be significantly different from the background color;

[0017] For the calibration markers, the distance between adjacent intersections of the calibration markers is also required to be consistent with the theoretical value, and the position accuracy requirement is higher than the position accuracy requirement of the feature markers.

[0018] In some implementations, extracting and locating feature points from a feature area in each frame of the image specifically includes:

[0019] Dividing the image into feature regions, and taking a region formed by sequentially connecting four endpoints of the feature identifier as the feature region;

[0020] A pixel point with the highest grayscale value around the intersection of two engraved lines or a pixel point with the highest contrast gradient between the true color and the background at the intersection of two engraved lines is extracted from the feature area as the positioning feature point.

[0021] In some embodiments, the extracting and locating feature points from the feature area in each frame of the image further includes:

[0022] If a pixel point with the highest contrast gradient cannot be extracted, the geometric center point of the feature area is used as the positioning feature point.

[0023] In some embodiments, the extracting and locating feature points from the feature area in each frame of the image further includes:

[0024] A group of positioning feature points of a plurality of continuous feature areas are extracted from the image.

[0025] In a second aspect, the present application proposes a system for acquiring a motion curve of a slender member, the acquisition system comprising:

[0026] A calibration module, wherein the calibration module is configured to: extract the pixel length between any two groups of calibration marks from the moving part calibration image, and obtain the proportional relationship between the pixel length and the actual distance; wherein the moving part calibration image is an image including at least three groups of calibration marks pre-made on the moving part;

[0027] A feature extraction module, wherein the feature extraction module is configured to: acquire a plurality of frames of images of the entire stroke of the moving component in real time, and extract positioning feature points from a feature area in each frame of the image and obtain pixel coordinate values ​​of the positioning feature points; wherein the feature area is determined by a feature identifier pre-made on the corresponding visible stroke area of ​​the moving component;

[0028] And, a timing processing module, the timing processing module is configured to: obtain the pixel coordinate value change of the same positioning feature point in two adjacent frames of images in the image in a time sequence in units of pixels, so as to determine the pixel displacement of the positioning feature point, and calculate the actual movement distance of the moving part according to the proportional relationship; calculate the speed at the corresponding moment according to the actual movement distance of the moving part and the interval time obtained by two adjacent frames of images; complete the processing of all images according to the above process, and obtain the curve of the change of the speed of the moving part over time during the entire stroke;

[0029] Among them, the calibration mark and the characteristic mark both adopt a cross-like mark.

[0030] In some embodiments, the acquisition system further comprises:

[0031] A calculation module is configured to: integrate the curve of the speed variation over time of the entire stroke of the moving component to obtain the curve of the displacement variation over time, and differentiate to obtain the curve of the acceleration variation over time.

[0032] In some embodiments, the acquisition system further comprises:

[0033] An image acquisition module is configured to acquire a calibration image of the moving component and to acquire a plurality of frames of images of the entire travel of the moving component in real time.

[0034] In some embodiments, the feature extraction module further includes:

[0035] A region division unit, wherein the region division unit is configured to: perform feature region division on the image, and use a region formed by sequentially connecting four endpoints of the feature identifier as a feature region;

[0036] And, a pixel point extraction unit, the pixel point extraction unit is configured to: extract the pixel point with the highest grayscale value around the intersection of two engraved lines or the pixel point with the highest true color and background contrast gradient at the intersection of two engraved lines from the feature area as a positioning feature point and obtain its pixel coordinate value; if the pixel point cannot be extracted, then use the geometric center point of the feature area as the positioning feature point and obtain its pixel coordinate value.

[0037] In some implementations, the pixel extraction unit is further configured to: simultaneously extract a group of positioning feature points of a plurality of consecutive feature areas.

[0038] In some implementations, the production requirements for the calibration mark and the feature mark are:

[0039] The size, line width and spacing of the multiple cross-like marks should be maintained, and the intersection points of the cross-like marks along the direction of movement should be on the same straight line, and the following conditions should be met: under high magnification, the mark color should be significantly different from the background color;

[0040] For the calibration markers, the distance between adjacent intersections of the calibration markers is also required to be consistent with the theoretical value, and the position accuracy requirement is higher than the position accuracy requirement of the feature markers.

[0041] In a third aspect, the present application proposes a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0042] The present application proposes a method, system and device for acquiring a travel motion curve of a slender member, which uses a cross-like mark as a marker. The production requirements of such a marker are relatively low, and the marker calibration technology and the marker feature extraction technology are combined to achieve a high positioning accuracy, a good capture effect, and a high precision of the processed data, and retain the advantages of not changing the drive line structure and not interfering with the drive line flow field.

[0043] The present application proposes a method, system and device for acquiring the travel motion curve of a slender part, which adopts the jump point positioning technology of the mark, and performs feature recognition by grouping multiple consecutive marks. When a group of features of the moving part overflows the shooting window and the mark is incomplete, a new group of complete extraction objects can be regenerated to achieve the continuity of jump point tracking and mark extraction.

[0044] The present application proposes a method, system and device for acquiring the travel motion curve of a slender member, which is particularly suitable for measuring the travel of a control rod drive line, and provides strong technical support for the optimal design of the control rod drive line. It can also be extended to the acquisition of the travel motion curves of other slender members, and is not limited to drive line tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The drawings described herein are used to provide a further understanding of the embodiments of the present application, constitute a part of the present application, and do not constitute a limitation on the embodiments of the present application. In the drawings:

[0046] Figure 1 A flow chart of a method according to an embodiment of the present application;

[0047] Figure 2 It is the feature identifier within the visual window of the high-speed camera;

[0048] Figure 3 This is a system principle block diagram of an embodiment of the present application;

[0049] Figure 4 This is a diagram of the computer device architecture of an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with examples and drawings. The illustrative implementation scheme of the present application and its description are only used to explain the present application and are not intended to limit the present application.

[0051] Example:

[0052] The traditional drive line rod drop stroke measurement is achieved by using a rod position detector. However, due to its own characteristics, the rod position detector has poor time accuracy, and the obtained stroke accuracy is not high and the precision is low. The existing method of using horizontal engravings is subject to the accuracy of the processed curve by the production method and effect of the engravings, that is, the production of the engravings is required to be high, and at the same time, the positioning accuracy of the engravings is reduced, the positioning difficulty is large, and the precision is limited. In view of this, this embodiment proposes a method for obtaining the stroke motion curve of slender parts. The method proposed in this embodiment adopts a cross-like mark and combines it with the mark calibration technology to establish a proportional relationship between image pixels and actual distance, improve the accuracy of relative displacement in image processing, and realize the rapid and accurate acquisition of the stroke motion curve. Without changing the drive line structure and interfering with the drive line flow field, the mark production requirements are reduced and the data accuracy is improved.

[0053] like Figure 1 As shown, the acquisition method proposed in this embodiment specifically includes the following steps:

[0054] Step 100, obtain a moving part calibration image, and extract the pixel length between any two sets of calibration marks from the moving part calibration image to obtain the proportional relationship between the pixel length and the actual distance. The moving calibration image is an image including no less than 3 sets of calibration marks pre-made on the moving part (at the starting point or end point of the moving part's travel).

[0055] Step 200, real-time acquisition of several frames of images of the full stroke of the moving part with pre-made feature marks corresponding to the visible stroke area (such as the visible stick drop area), and extraction of positioning feature points from each frame of the image and acquisition of pixel coordinate values ​​of the positioning feature points. The positioning feature points are pixels at the intersection of the scribed lines with a high contrast gradient with the surrounding grayscale values ​​or pixels with the highest contrast gradient between the true color and the background.

[0056] Step 300, obtain the change in pixel coordinate value in pixels of the same positioning feature point in two adjacent frames of images in time sequence, so as to determine the pixel displacement of the positioning feature point, calculate the actual movement distance of the moving part according to the proportional relationship between the pixel length and the actual distance, and calculate the speed at the corresponding moment in combination with the interval time of the two adjacent frames of images. It should be noted that the time sequence mentioned in this step refers to the chronological order. The specific principle for determining pixel displacement is to perform difference calculation on the pixel coordinate values ​​of the same positioning feature point in the two frames of images to obtain the change in coordinate value, and then calculate the pixel displacement of the same positioning feature point according to the coordinate value variable value. For example, the pixel coordinate values ​​of the same positioning feature point in the previous and next two frames of images are (x1, y1) and (x2, y2), respectively, then the change in coordinate value is (x1-x2, y1-y2), and the pixel displacement is The control rod drive line usually moves in the same direction, so only the change in the y-axis can be used as the pixel displacement value. In addition, the speed is equal to the distance divided by the time, that is, the actual movement distance and time interval are obtained, and the speed at the corresponding moment can be calculated.

[0057] Step 400, repeat the previous step to obtain a curve of the speed of the moving part changing with time throughout the entire stroke.

[0058] In an optional implementation manner, the acquisition method proposed in this embodiment further includes:

[0059] Step 500: Based on the curve of speed varying with time of the entire stroke, the curve of displacement varying with time is integrated, and the curve of acceleration varying with time is differentiated.

[0060] In an optional implementation, before executing step 100, it is necessary to make calibration marks at the starting point or end point of the moving part's travel, and the spacing between the calibration marks needs to ensure that there are no less than three groups of calibration marks in the high-speed camera window.

[0061] Before executing the above step 100, it is also necessary to make a characteristic mark on the moving part corresponding to the visible rod drop area. Optionally, the mark at the end of the stroke is connected longitudinally, and a short horizontal line is added at a fixed distance, similar to the scale line of a ruler, for manual quick reading of details such as the rebound height of the moving part, such as Figure 2 As shown in the upper scale line, since the spacing between two adjacent horizontal short lines in the scale line is fixed and known, the rebound height of the moving part can be determined directly by the number of lines.

[0062] The above-mentioned calibration marks and characteristic marks all adopt cross-like marks, which are marks that have cross-shaped features as a whole and have four endpoints. Such cross marks include but are not limited to cross-shaped lines, two intersecting line segments, BMW logos, etc. The size, line width and spacing of multiple cross-like marks should be consistent, and the intersection points of each mark along the direction of movement should be on the same straight line. The color production requirements of the marks are: for cross-shaped lines and two intersecting line segments, the color of the mark should be significantly different from the background color under high magnification of a high-speed camera (that is, the contrast gradient of the grayscale values ​​of the two is greater than the threshold); for the BMW logo, the two sets of diagonal colors or grayscale values ​​should be significantly different (that is, the contrast gradient of the color or grayscale values ​​of one diagonal and another diagonal of the BMW logo is greater than the threshold). In addition, for calibration marks, in addition to being strictly produced in accordance with the above requirements and fully meeting the requirements for color, spacing, etc., it is also required that the distance between the intersection points of adjacent calibration marks is consistent with the theoretical value, and the position accuracy is strictly controlled, that is, the position accuracy requirement is higher than the position accuracy requirement of the characteristic mark.

[0063] After completing the marking on the moving part, a calibration image of the moving part containing no less than 3 groups of calibration marks is obtained by a high-speed camera. The pixel length between any two groups of calibration marks is extracted from the calibration image of the moving part. Combined with the actual distances corresponding to the two groups of calibration marks, the proportional relationship between the pixel length and the actual distance can be calculated for the subsequent calculation of the actual movement distance of the moving part.

[0064] In an optional implementation, in step 200, the image is first divided into feature regions, and the region formed by connecting the four endpoints of the cross-like mark in sequence is generally used as the feature region; a frame of image includes multiple feature regions. Then, a pixel point with the highest grayscale value around the intersection of two engraved lines or the highest true color and background contrast gradient at the intersection of two engraved lines is extracted from each feature region as a positioning feature point. If the pixel point cannot be extracted (for example, when the feature mark is worn), the geometric center point of the feature region is used as the positioning feature point and its pixel coordinate value is obtained.

[0065] An optional implementation method is that during the process of locating feature point extraction, a group of locating feature points of multiple consecutive feature areas can be identified simultaneously. This can ensure that if a group of features of the moving part overflows the high-speed camera window or the feature identification is incomplete, a new group of complete extraction objects can be regenerated to achieve the continuity of jump point tracking and feature identification extraction.

[0066] The acquisition method proposed in this embodiment uses a cross-like mark as a logo. The production requirements of this type of mark are relatively low. It combines the mark calibration technology and the mark feature extraction technology to achieve high positioning accuracy, good capture effect, and high data accuracy. It also retains the advantages of not changing the drive line structure and not interfering with the drive line flow field.

[0067] The acquisition method proposed in this embodiment also adopts the jump point positioning technology of the marker, and performs feature recognition on multiple consecutive markers as a group. When a group of features of the moving part overflows the shooting window and the marker is incomplete, a new group of complete extraction objects can be regenerated to achieve the continuity of jump point tracking and marker extraction.

[0068] The acquisition method proposed in this embodiment has been successfully applied to multiple control rod cold drop test projects such as LV and ACP25S, and will also be widely used in subsequent similar test projects, with high market value. This method is particularly suitable for the measurement of the motion stroke of the control rod drive line, providing a strong technical support for the optimal design of the control rod drive line, and can also be extended to the acquisition of the stroke motion curve of other slender parts, not limited to the drive line test.

[0069] Based on the same technical concept as above, this embodiment also proposes a system for obtaining a motion curve of a slender member, such as Figure 3 As shown, the acquisition system proposed in this embodiment includes:

[0070] The calibration module is configured to obtain a calibration image of the moving part, and extract the pixel length between any two sets of calibration marks from the calibration image of the moving part to obtain the proportional relationship between the pixel length and the actual distance. The motion calibration image is an image including at least three sets of calibration marks pre-made on the moving part. Among them, at least three sets of calibration marks can be pre-made at the starting point or the end point of the moving part's travel.

[0071] A feature extraction module, the feature extraction module is configured to: acquire in real time several frames of images of the full stroke of the moving parts with feature marks pre-made in the corresponding visible stick drop area, and extract the positioning feature points from each frame of the image and obtain the pixel coordinate values ​​of the positioning feature points. Among them, the positioning feature points are the pixels with the highest grayscale values ​​or true color and background contrast gradient around the intersection of the two engraved lines. Optionally, the positioning feature points can also use the geometric center point of the feature area. For example, when the feature mark is worn, it is impossible to extract the grayscale values ​​around the intersection of the two engraved lines or the pixels with the highest true color and background contrast gradient. In this case, the above-mentioned geometric center point can be used as the positioning feature. Among them, the feature area refers to the area formed by connecting the four endpoints of the feature mark in sequence.

[0072] And, a timing processing module, which is configured to: obtain the coordinate change in pixels of the same positioning feature point in two adjacent frames of images in a time sequence, so as to determine the pixel displacement of the positioning feature point, and the actual movement distance of the moving part can be obtained according to the proportional relationship between the pixel length and the actual distance, and the speed at the corresponding moment can be obtained by combining the time interval between the two adjacent frames of images. After completing the processing of all images according to the above process, a curve of the speed change over time in the entire journey can be obtained. The principles of pixel displacement and speed calculation are as described in the above method, and will not be repeated here.

[0073] In an optional implementation manner, the acquisition system proposed in this embodiment further includes:

[0074] The calculation module is configured to: integrate the curve of velocity variation over time output by the timing processing module to obtain the curve of displacement variation over time, and differentiate to obtain the curve of acceleration variation over time.

[0075] In an optional implementation, the above-mentioned calibration mark and characteristic mark are both cross-like marks, which are marks that have a cross-shaped feature as a whole and have four endpoints. Such cross marks include but are not limited to cross-shaped marks, two intersecting line segments, BMW logos, etc. The size, line width and spacing of multiple cross-like marks should be consistent, and the intersection points of each mark along the direction of movement should be on the same straight line. The color production requirements of the mark are: for cross-shaped marks and two intersecting line segments, the mark color and the background color should be significantly different under high magnification of a high-speed camera (that is, the contrast gradient of the grayscale values ​​of the two is greater than the threshold); for the BMW logo, the two sets of diagonal colors or grayscale values ​​should be significantly different (that is, the contrast gradient of the color or grayscale values ​​of one diagonal and another diagonal of the BMW logo is greater than the threshold). In addition, for the calibration mark, in addition to being strictly produced in accordance with the above requirements and fully meeting the requirements for color, spacing, etc., it is also required that the distance between adjacent intersection points of the calibration mark is consistent with the theoretical value, and the position accuracy is strictly controlled, that is, the position accuracy requirement is higher than the position accuracy requirement of the characteristic mark.

[0076] In an optional implementation manner, the feature extraction module further includes:

[0077] The region division unit is configured to: divide the image into feature regions, usually using a region formed by sequentially connecting four end points of a cross-like mark as a feature region; a frame of image includes multiple feature regions.

[0078] And, a pixel point extraction unit, which is configured to: extract the grayscale values ​​around the intersection of two scale lines or the pixel point with the highest contrast gradient between the true color and the background at the intersection of two scale lines from each feature area as a positioning feature point and obtain its pixel coordinate value; if the pixel point cannot be extracted, the geometric center point of the feature area is used as the positioning feature point and its pixel coordinate value is obtained.

[0079] In an optional implementation, the pixel point extraction unit is configured to simultaneously identify a group of positioning feature points of multiple consecutive feature areas, that is, to extract positioning feature points in groups (similar to a sliding window method). In this way, when a group of features of a moving part overflows the high-speed camera window or the feature identification is incomplete, a new group of complete extraction objects can be regenerated to achieve continuity of jump point tracking and feature identification extraction.

[0080] In an optional implementation manner, the acquisition system proposed in this embodiment further includes:

[0081] The image acquisition module is configured to acquire a calibration image of the moving part and to acquire a plurality of frames of images of the entire travel of the moving part in real time. Preferably, the data acquisition module may adopt, but is not limited to, a high-speed camera.

[0082] This embodiment also provides a computer device for executing the above method of this embodiment.

[0083] Specific as Figure 4 As shown, a computer device includes a processor, a memory and a system bus; various device components including the memory and the processor are connected to the system bus. The processor is a piece of hardware used to execute computer program instructions through basic arithmetic and logical operations in a computer system. The memory is a physical device used to temporarily or permanently store computer programs or data (e.g., program status information). The system bus can be any of the following types of bus structures, including a memory bus or a memory controller, a peripheral bus, and a local bus. The processor and the memory can communicate data through the system bus. The memory includes a read-only memory (ROM) or a flash memory (not shown in the figure), and a random access memory (RAM), and RAM generally refers to the main memory loaded with the operating system and computer programs.

[0084] Computer equipment generally includes a storage device. The storage device can be selected from a variety of computer-readable media, which refers to any available media that can be accessed by the computer equipment, including both removable and fixed media. For example, computer-readable media include, but are not limited to, flash memory (micro SD card), CD-ROM, digital versatile disc (DVD) or other optical disk storage, magnetic tape cassette, magnetic tape, magnetic disk storage or other magnetic storage device, or any other medium that can be used to store the desired information and can be accessed by the computer equipment.

[0085] Computer devices can be logically connected to one or more network terminals in a network environment. Network terminals can be personal computers, servers, routers, smart phones, tablets, or other public network nodes. Computer devices are connected to network terminals through network interfaces (local area network LAN interfaces). Local area network (LAN) refers to a network of computers interconnected within a limited area, such as a home, school, computer laboratory, or office building using network media. WiFi and twisted pair cabling Ethernet are the two most commonly used technologies for building LANs.

[0086] It should be noted that other computer systems including more or fewer subsystems than a computer device may also be suitable for the invention.

[0087] As described in detail above, the computer device applicable to the present embodiment can perform the specified operations of the above-mentioned method for obtaining the motion curve of the travel of the slender member. The computer device performs these operations in the form of software instructions running in a computer-readable medium by a processor. These software instructions can be read into the memory from a storage device or from another device through a local area network interface. The software instructions stored in the memory enable the processor to execute the above-mentioned method for obtaining the motion curve of the travel of the slender member. In addition, the present invention can also be implemented by hardware circuits or hardware circuits combined with software instructions. Therefore, the implementation of this embodiment is not limited to any specific combination of hardware circuits and software.

[0088] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for obtaining a travel motion curve of a slender member, characterized in that: The acquisition method comprises: Extracting the pixel length between any two groups of the calibration marks from the moving part calibration image, and obtaining the proportional relationship between the pixel length and the actual distance; wherein the moving part calibration image is an image including at least three groups of calibration marks pre-made on the moving part; Acquire several frames of images of the entire stroke of the moving component in real time, extract positioning feature points from the feature area in each frame of the image, and obtain pixel coordinate values ​​of the positioning feature points; wherein the feature area is determined by a feature mark pre-made on the corresponding visible stroke area of ​​the moving component; The pixel coordinate value variation of the same positioning feature point in two adjacent frames of images is obtained in time sequence in units of pixels, so as to determine the pixel displacement of the positioning feature point, and the actual movement distance of the moving part is calculated according to the proportional relationship; the speed at the corresponding moment is calculated according to the actual movement distance of the moving part and the interval time between the two adjacent frames of images; Repeat the previous step to obtain a curve of the entire stroke speed of the moving part changing with time; Among them, the calibration mark and the characteristic mark both adopt a cross-like mark.

2. A method for obtaining a travel motion curve of a slender member according to claim 1, characterized in that: The acquisition method further includes: According to the curve of the speed variation over time of the entire stroke of the moving component, the curve of the displacement variation over time is obtained by integration, and the curve of the acceleration variation over time is obtained by differentiation.

3. A method for obtaining a travel motion curve of a slender member according to claim 1 or 2, characterized in that: The production requirements for the calibration mark and feature mark are as follows: The size, line width and spacing of the multiple cross-like marks should be maintained, and the intersection points of the cross-like marks along the direction of movement should be on the same straight line, and the following conditions should be met: under high magnification, the mark color should be significantly different from the background color; For the calibration markers, the distance between adjacent intersections of the calibration markers is also required to be consistent with the theoretical value, and the position accuracy requirement is higher than the position accuracy requirement of the feature markers.

4. A method for obtaining a travel motion curve of a slender member according to claim 1 or 2, characterized in that: The extracting and locating feature points from the feature area in each frame of the image specifically includes: Dividing the image into feature regions, and taking a region formed by sequentially connecting four endpoints of the feature identifier as the feature region; A pixel point with the highest grayscale value around the intersection of two engraved lines or a pixel point with the highest contrast gradient between the true color and the background at the intersection of two engraved lines is extracted from the feature area as the positioning feature point.

5. A method for obtaining a travel motion curve of a slender member according to claim 4, characterized in that: The extracting and locating feature points from the feature area in each frame of the image further includes: If a pixel point with the highest contrast gradient cannot be extracted, the geometric center point of the feature area is used as the positioning feature point.

6. A method for obtaining a travel motion curve of a slender member according to claim 4, characterized in that: The extracting and locating feature points from the feature area in each frame of the image further includes: A group of positioning feature points of a plurality of continuous feature areas are extracted from the image.

7. A system for acquiring a travel motion curve of a slender member, characterized in that: The acquisition system comprises: A calibration module, wherein the calibration module is configured to: extract the pixel length between any two groups of calibration marks from the moving part calibration image, and obtain the proportional relationship between the pixel length and the actual distance; wherein the moving part calibration image is an image including at least three groups of calibration marks pre-made on the moving part; A feature extraction module, wherein the feature extraction module is configured to: acquire a plurality of frames of images of the entire stroke of the moving component in real time, and extract positioning feature points from a feature area in each frame of the image and obtain pixel coordinate values ​​of the positioning feature points; wherein the feature area is determined by a feature identifier pre-made on the corresponding visible stroke area of ​​the moving component; And, a timing processing module, the timing processing module is configured to: obtain the pixel coordinate value change of the same positioning feature point in two adjacent frames of images in the image in a time sequence in units of pixels, so as to determine the pixel displacement of the positioning feature point, and calculate the actual movement distance of the moving part according to the proportional relationship; calculate the speed at the corresponding moment according to the actual movement distance of the moving part and the interval time obtained by two adjacent frames of images; complete the processing of all images according to the above process, and obtain the curve of the change of the speed of the moving part over time during the entire stroke; Among them, the calibration mark and the characteristic mark both adopt a cross-like mark.

8. A system for acquiring a travel motion curve of a slender member according to claim 7, characterized in that: The acquisition system further comprises: A calculation module is configured to: integrate the curve of the speed variation over time of the entire stroke of the moving component to obtain the curve of the displacement variation over time, and differentiate to obtain the curve of the acceleration variation over time.

9. A system for acquiring a travel motion curve of a slender member according to claim 7, characterized in that: The acquisition system further comprises: An image acquisition module is configured to acquire a calibration image of the moving component and to acquire a plurality of frames of images of the entire travel of the moving component in real time.

10. A system for acquiring a travel motion curve of a slender member according to any one of claims 7 to 9, characterized in that: The feature extraction module also includes: A region division unit, wherein the region division unit is configured to: perform feature region division on the image, and use a region formed by sequentially connecting four endpoints of the feature identifier as a feature region; And, a pixel point extraction unit, the pixel point extraction unit is configured to: extract the pixel point with the highest grayscale value around the intersection of two engraved lines or the pixel point with the highest true color and background contrast gradient at the intersection of two engraved lines from the feature area as a positioning feature point and obtain its pixel coordinate value; if the pixel point cannot be extracted, then use the geometric center point of the feature area as the positioning feature point and obtain its pixel coordinate value.

11. A system for acquiring a travel motion curve of a slender member according to claim 10, characterized in that: The pixel extraction unit is further configured to simultaneously extract a group of positioning feature points of a plurality of continuous feature areas.

12. A system for acquiring a travel motion curve of a slender member according to any one of claims 7 to 9, characterized in that: The production requirements for the calibration mark and feature mark are as follows: The size, line width and spacing of the multiple cross-like marks should be maintained, and the intersection points of the cross-like marks along the direction of movement should be on the same straight line, and the following conditions should be met: under high magnification, the mark color should be significantly different from the background color; For the calibration markers, the distance between adjacent intersections of the calibration markers is also required to be consistent with the theoretical value, and the position accuracy requirement is higher than the position accuracy requirement of the feature markers.

13. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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