Automatic leveling and auto-focusing hardened concrete bubble spacing coefficient analyzer

Abstract

This invention proposes an automatic clamping and automatic focusing instrument for analyzing the air bubble spacing coefficient of hardened concrete, including a control module, an automatic clamping system, and an automatic focusing system. The automatic clamping system includes a stage for placing a sample block, and multiple horizontal clamps surrounding the stage. The sidewalls of the sample block are perpendicular to the test surface on its top. The front end of the clamps is provided with right-angle limiting blocks that cooperate with the top and side surfaces of the sample block. The right-angle limiting blocks of the multiple clamps are located at the same height. The stage is supported by a spherical connecting rod and an elastic element, allowing the stage to swing within a threshold range. When clamping the sample block, the right-angle limiting blocks of the multiple clamps contact the top periphery of the sample block and limit the top surface and sidewalls of the sample block, keeping the test surface on the top of the sample block horizontal so that the automatic focusing system can focus on the test surface. This invention can test slice samples of various shapes and sizes, achieves automatic clamping and leveling, reduces the workload of focusing, and makes operation simpler and more automated.

Description

Technical Field

[0001] This invention relates to testing equipment, and in particular to an automatic clamping and focusing analyzer for analyzing the air bubble spacing coefficient of hardened concrete. Background Technology

[0002] Currently, the main instrument for testing the air bubble parameters of hardened concrete is the hardened concrete air bubble spacing coefficient analyzer (hereinafter referred to as the analyzer). Existing analyzers use springs to lift the slice upwards, and limiting plates to keep the two edges at the same height. However, due to manual operation and other reasons, the slice edges may sink, causing the internal observation points to be at different heights. Furthermore, traditional stages cannot accommodate test samples of various shapes and sizes. When the scanned image changes from clear to blurry, the process pauses and the lens height is adjusted. Since a single test takes approximately 10,000 images, this significantly increases labor costs.

[0003] Meanwhile, when analyzing the bubble spacing of hardened concrete specimens, the specimen surface has defects such as slope and pits due to improper cutting, which leads to difficulties in microscope focusing, unclear images, and a large amount of manual focusing work. The existing instrument fixtures are too simple and can only test samples of specific sizes and shapes. Furthermore, due to uneven force, problems such as "uneven clamping" may occur, as detailed below.

[0004] (1) The existing hardened concrete bubble spacing coefficient analyzer (hereinafter referred to as the analyzer) has a simple clamp, which has problems of "not being able to clamp evenly" and "not being able to clamp properly". As shown in Figure 1: the existing analyzer clamp will cause the observation points to be not on the same plane due to the unevenness of the concrete slice edges; at the same time, the existing clamp is very poor in clamping and fixing "small test blocks" and "circular test blocks", and may even fail to clamp them. The reason is that the existing analyzer clamp uses a spring to lift the slice upwards, and the limiting plate makes the two edges at the same height. However, since the three limiting points are relatively close to being on the same straight line, the slice is easy to tilt. As a result, the internal observation points are not at the same height. At the same time, due to cutting and other reasons, the test surface often has a certain slope, which will cause the points on the slope to be not on the same horizontal plane, so that the focus needs to be refocused every certain distance, which greatly increases the time and labor costs.

[0005] Therefore, this invention improves the fixture and stage, so that the fixture can clamp test blocks of various shapes and sizes; at the same time, it can keep the test surface as horizontal as possible, reducing the amount of focusing work.

[0006] (2) The internal structure of the slice may also be affected by cutting, grinding, polishing, and defects in the sample itself (collapse, cracks in the interface transition zone, pores, etc.), as shown in Figure 2. This causes differences in the height of the observation point captured by the microscope during the movement of the displacement platform, making it impossible to maintain focus and resulting in unclear images.

[0007] When using an analyzer for testing, if the scanned image changes from clear to blurry, the lens height should be adjusted and paused. However, since a single test takes around 10,000 images, adjusting the lens height would significantly increase labor costs.

[0008] This invention uses a laser rangefinder to provide feedback on the "distance" height and the lens to automatically focus, ensuring that the lens is always in focus, which can greatly reduce the manpower and time required for operation. Summary of the Invention

[0009] This invention proposes an automatic clamping and focusing analyzer for the air bubble spacing coefficient of hardened concrete. Improvements to the clamps and stage allow the clamps to hold specimens of various shapes and sizes; automatic clamping reduces focusing workload, simplifying operation and increasing automation. Furthermore, this invention improves upon traditional analyzers based on laser ranging principles, enabling automatic adjustment of the objective lens height according to the laser rangefinder sensor's measurement results, ensuring the objective lens remains in focus with the observed point. The combination of these two features solves problems such as image blurring and time-consuming manual adjustments, and allows for the testing of slice samples of various shapes and sizes.

[0010] The present invention adopts the following technical solution.

[0011] An automatic clamping and automatic focusing analyzer for the air bubble spacing coefficient of hardened concrete, the analyzer includes a control module and an automatic clamping system and an automatic focusing system connected thereto; the automatic clamping system includes a stage (18) for placing a sample block (17), and also includes multiple horizontal clamps (13) surrounding the stage; the sidewall of the sample block is perpendicular to the test surface on its top; the front end of the clamp is provided with a right-angle limiting block (25) that cooperates with the top and side surfaces of the sample block; the right-angle limiting blocks of the multiple clamps are located at the same height; the stage is supported on a base (15) by a ball joint (19) and an elastic element (16) so that the stage can swing within a threshold range; when clamping the sample block, the right-angle limiting blocks of the multiple clamps contact the top periphery of the sample block and limit the top surface and sidewall of the sample block, so that the test surface on the top of the sample block remains horizontal so that the automatic focusing system can focus on the test surface.

[0012] The right-angle limiting blocks of multiple clamps are of the same specification; the stage is rectangular, and the spherical connecting rod is located in the center of the stage; the elastic element is four springs located at the four corners of the stage. When the sample block is clamped, the springs press the stage against the clamped sample block.

[0013] The clamp is provided with a horizontal clamp rack (22), and the clamp is located in a limiting groove (24) for limiting the rotation of the clamp and can slide horizontally.

[0014] There are four clamps, which are placed in the middle of the four sides of a rectangular clamp frame (12). The clamp frame is supported on the base by the base connecting rod (11) at its corner end and surrounds the outside of the stage. A stepper motor group (14) is provided at the side of the clamp frame. The stepper motor group includes a stepper motor connected to the vertical rack of the base connecting rod and a stepper motor connected to the clamp rack. The stepper motor connected to the base connecting rod rack is used to drive the clamp frame to move up and down when clamping the sample block. The stepper motor connected to the clamp rack is used to drive the clamp to move horizontally when clamping the sample block.

[0015] The right-angle limiting block is used to fix the clamping surface of the sample block and is equipped with a pressure sensing plate (23) connected to the control module. The pressure sensing plate is used to feed back the clamping force data of the fixture to the control module so that the control module can adjust the clamping stability of the fixture on the sample block.

[0016] The sample block can be in the shape of a cube or a cylinder. When the sample block is clamped, if the test surface at the top of the sample block has a slope, the stage rotates under the pressure of the right-angle limit block of the clamp to fit the bottom surface of the sample block in an inclined posture, so that the test surface at the top of the sample block is adjusted to a horizontal posture under the limit of the right-angle limit block.

[0017] The autofocus system is located above the automatic clamping system and includes a microscope lens (1) placed at the microscope tube (2); the microscope tube is connected to the microscope height adjustment thread (3) of the automatic microscope focusing system (8); a laser emitter (4) and a laser receiver (10) connected to the control module are provided on the side wall of the microscope tube. When autofocusing is performed, the reflected light of the ranging laser (5) emitted by the laser emitter at the laser ranging observation point on the test surface of the sample block is received by the laser receiver, so that the control module can obtain the height of the microscope tube relative to the test surface of the sample block and adjust this height so that the microscope focal point (7) coincides with the laser ranging observation point to complete the focusing. After the focusing is completed, the microscope begins to record the image of the test surface of the sample block.

[0018] The automatic microscope focusing system includes a microcontroller and a high-precision stepper motor SM; the high-precision stepper motor SM is connected to the microscope height adjustment thread via a gear set with a gear ratio of 400 to drive the microscope tube to rise and fall, and to finely adjust the height of the microscope tube relative to the test surface of the sample block.

[0019] The control module uses triangular laser ranging to measure the distance between the test surfaces of the sample block via a laser transmitter and a laser receiver.

[0020] The base is provided with a laser beam transceiver device for roughly measuring the height of the test block; the laser beam transceiver device includes a pair of vertically arranged laser columns (20), which are arranged at equal intervals in the vertical direction with multiple laser transceiver positions, so that a horizontal laser beam (21) pointing to the test block at the stage is emitted or received at intervals, and the height of the lowest horizontal laser beam that is not blocked by the test block is used as the rough height of the test block.

[0021] The working process of the analyzer on the sample block includes the following steps;

[0022] Step S1: Place the test surface of the sample block upwards in the middle of the stage to block the horizontal laser emitted by the base laser column; take the height of the first blocked horizontal laser beam as the approximate position height of the highest point of the unclamped sample block, and turn off the laser; the stepper motor group drives the fixture and fixture frame to automatically descend to the height of the lowest fully penetrating horizontal laser beam.

[0023] Step S2: Driven by the stepper motor group, the four clamps automatically begin to gradually move towards the center of the stage until all four clamps reach the edge of the test block.

[0024] Step S3: The stepper motor assembly uses the base connecting rod as the force point to press down the clamp frame, clamps and sample block. At the same time, the four clamps begin to move closer together. At this time, under the pressure of the right-angle limit blocks of the four clamps, the test surface on the top of the sample block is adjusted to a horizontal position, while the lower surface will press the stage to tilt. As the four clamps continue to move closer together, the sample block is also clamped.

[0025] Step S4: After the control module senses that the clamping force of the four clamps is not lower than the threshold through the pressure sensor, the stepper motor group locks the clamps to complete the automatic clamping of the sample block.

[0026] Step S5: First, set the observation point on the test surface of the sample block as the starting point for the analyzer scanning. Then, adjust the microscope focus, lens height, and the height between the sample and the test piece to maintain the clearest field of view. The laser range sensor connected to the laser emitter and laser receiver measures the distance between itself and the observation point as the initial focal length. After the measurement is completed, turn off the laser and feed the data back to the automatic microscope focusing system.

[0027] Step S6: The microscope begins recording the image of the observation point, which serves as the analysis image at the starting point of the analyzer's scan;

[0028] Step S7: After the microscope has finished recording the image of the observation point, the stage moves the sample block and moves the scanning position of the sample block under the microscope to the next observation point on the test surface of the sample block.

[0029] Step S8: The distance sensor re-measures the distance between the next observation point on the test surface of the sample block and the microscope objective lens and feeds it back to the automatic microscope focusing system. The automatic microscope focusing system automatically calculates the current distance measurement data. If the current distance measurement data differs from the initial focal length data in step S5 by more than 0.05 mm, the microcontroller of the automatic microscope focusing system calculates and controls the stepper motor SM to drive the microscope height adjustment screw to rotate the corresponding number of turns, so that the microscope lens moves vertically, thereby moving the microscope focus to a height close to the initial focal length, thereby achieving the purpose of focusing.

[0030] Step S9: The microscope begins recording images of the new observation point;

[0031] Step S10: The stage moves the observation point of the specimen to the next point and repeats the above microscope focusing and image recording process.

[0032] The inventive improvement of this invention lies in:

[0033] (1) Improved the base and designed a laser column device that can simply and cost-effectively measure the approximate height of the highest point of the specimen;

[0034] This invention adds two laser columns at the corners of the base, one emitting and the other receiving laser beams. Only one laser beam needs to be emitted or received approximately every 7mm. Used in conjunction with these laser beams, they are used to measure the approximate height of the test block, providing data for the initial descent height of the clamping frame. The base also includes a rack-and-pinion linkage. The rack allows a stepper motor to move the clamping frame up and down, while also fixing the clamping frame in place, providing the first step for automated test block clamping.

[0035] (2) Improve the traditional clamps to create a system that can automatically clamp and lock the test blocks;

[0036] First, through the detection of the laser column and laser beam, the fixture frame can automatically measure the approximate height of the highest point of the test block. Then, under the action of the base connecting rod and the stepper motor group, it can achieve an automatic downward pressing function. At the same time, under the action of the fixture frame and the stepper motor group, the fixture can automatically move towards the center, achieving the function of automatically clamping the test block.

[0037] This invention designs four clamps with limiting grooves (as shown in Figure 9), which can be driven by a motor to push and pull back and forth, thereby clamping test blocks of any size and shape from four directions (as shown in Figure 5). The limiting grooves on the clamps ensure that they can only be pushed and pulled and cannot rotate. Moreover, the right-angle limiting blocks at the front ends of the four clamps are kept at the same level. Therefore, through the combined force of the four right-angle limiting blocks, the test block is tightly attached to the four clamps and their right-angle limiting blocks, which restricts the test surface of the test block and keeps it as horizontal as possible, reducing the adjustment range and workload of focusing. At the same time, the pressure sensing plate can provide feedback on the clamping force of the clamps so as to adjust the clamping stability.

[0038] (3) Improve the stage

[0039] As shown in Figure 6, the spherical connecting rod designed in this invention allows the stage to rotate freely within a certain angle without falling off, while the supporting force provided by the spring will cause the stage to fit tightly against the test block at a certain tilt angle (as shown in Figure 7), so that the entire clamping system is subjected to reasonable and uniform force, and is stable and firm.

[0040] (4) A new laser rangefinder sensor was added to the bubble spacing coefficient analyzer. This allows for a "range measurement" before each observation, facilitating refocusing.

[0041] This invention adds a laser rangefinder sensor. Before the microscope starts recording images each time, the distance between the current lens and the object under test (test surface of the sample block) needs to be measured by the laser rangefinder sensor to facilitate focusing. The microscope will only start recording images after focusing.

[0042] The laser sensor uses a triangulation laser ranging method, which is fast and accurate.

[0043] (5) Automatic microscope focusing system

[0044] A vertical Z-axis is added to the bubble spacing analyzer test platform to adjust the microscope height, enabling automatic focusing in conjunction with a laser rangefinder. While the laser rangefinder requires refocusing after measuring the distance, the automatic microscope focusing system eliminates the significant labor cost of manual refocusing each time. Furthermore, it boasts a high degree of intelligence, automatically calculating and adjusting, and achieving high accuracy.

[0045] After the laser rangefinder measures the distance, in order to reduce the labor cost of manual focusing, the automatic microscope focusing system can calculate the difference between the current "distance" and the "initial focal length" based on the value fed back by the laser rangefinder and automatically adjust the distance to achieve automatic focusing.

[0046] The combined improvements in these five aspects enable the fixture to automatically grip test blocks, reducing labor costs and improving the automation and intelligence of the instrument; allow the fixture to clamp test pieces of various sizes and shapes, such as cylinders and cubes, expanding the instrument's applicability; maintain horizontality even on sloped test surfaces, reducing focusing workload and minimizing the impact of uneven test piece boundaries; and ensure stable and reliable clamping, preventing accidental tipping of the test block. Simultaneously, the automatic focusing system automatically refocuses before recording images at each new observation point. This fundamentally solves the problems of "uneven test pieces," "unstable fixtures," "blurred image focus," and "high focusing labor costs."

[0047] This invention improves the clamps and stage of the analyzer, enabling the clamps to hold test blocks of various shapes and sizes. It also achieves automatic leveling, reducing focusing workload and simplifying operation while increasing automation. Furthermore, this invention improves upon traditional analyzers based on laser ranging principles, allowing the objective lens height to be automatically adjusted according to the ranging results from the laser rangefinder, ensuring the objective lens remains in focus with the observed point. The combination of these two improvements solves the problems of image blurring and time-consuming manual adjustments, and allows for the testing of slice samples of various shapes and sizes.

[0048] The advantages of this invention over traditional technologies are:

[0049] (1) More accurate data: The improved instrument can keep the microscope in focus throughout the test by automatically adjusting the microscope height, which improves the clarity of each frame of the picture and thus improves the accuracy of the measured data.

[0050] (2) Save time and manpower: At the start of the test, only the microscope height needs to be adjusted and the laser range needs to be measured at the test starting point. After the scanning starts, the range measurement result is fed back to the automatic focusing system, avoiding the need to manually adjust the microscope height and repeat the steps, which can greatly save manpower and labor costs.

[0051] (3) The new fixture can clamp specimens of various sizes and shapes such as cylinders and cubes, which increases the applicability of the instrument; the new fixture can keep the test surface with slope horizontal, reducing the amount of focusing work and manpower costs, and reducing the impact of uneven specimen boundaries; the new fixture clamps firmly and reliably, and the test block is not easy to accidentally tip over.

[0052] (4) Automatic gripping system can make the instrument more automated and intelligent. Attached Figure Description

[0053] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0054] Appendix Figure 1This is a schematic diagram of an autofocus system;

[0055] Appendix Figure 2 This is a schematic diagram of the fixture and the stage;

[0056] Appendix Figure 3 This is a schematic diagram of the fixture clamping the sample block;

[0057] Appendix Figure 4 This is a side view of the fixture clamping the sample block;

[0058] Appendix Figure 5 This is an enlarged schematic diagram of the fixture and fixture frame;

[0059] Appendix Figure 6 This is an enlarged schematic diagram of the fixture;

[0060] Appendix Figure 7 This is a schematic diagram showing the approximate height of the unclamped sample block roughly measured by a horizontal laser during the automatic clamping process.

[0061] Appendix Figure 8 This is a schematic diagram of the automatic clamping process of the test block when the fixture descends to the height of the lowest connected laser in the laser column;

[0062] Appendix Figure 9 This is a schematic diagram of the automatic clamping process where the fixture gathers towards the center until the edge of the sample block, and then the fixture frame begins to press down.

[0063] Appendix Figure 10 This is a schematic diagram of the automatic clamping process of the test block, with the upper surface of the test block tightly attached to the clamp, the platform tilted, and the clamp frame locked to the clamp.

[0064] Appendix Figure 11 This is an enlarged schematic diagram of the base connecting rod (SM in the diagram is the output terminal of the stepper motor).

[0065] Appendix Figure 12 This is a wiring diagram for the control module (microcontroller);

[0066] In the diagram: 1-Microscope lens; 2-Microscope tube; 3-Microscope height adjustment thread; 4-Laser emitter; 5-Range measuring laser; 6-Microscope focal length diagram; 7-Microscope focus point; 8-Automatic microscope focusing system; 9-Magnified diagram of the automatic microscope focusing system; 10-Laser receiver.

[0067] 11-Base connecting rod (with a rack on one side, which allows the stepper motor to push the clamp frame up and down, and also serves to fix the clamp frame).

[0068] 12-Clamping frame (used to provide a moving track and fixation for the clamp; a stepper motor assembly for pushing and pulling the clamp is installed inside);

[0069] 13- Fixture (with a right-angle limiting block at its front end);

[0070] 14-Stepper motor assembly (its power output end has a threaded structure, which can act as a push-pull clamp and move the clamp frame up and down, and at the same time, it can also lock the position).

[0071] 15-Base; 16-Elastic element (i.e., spring used to hold the stage and specimen together); 17-Specimen block; 18-Stage; 19-Spherical connecting rod;

[0072] 20-Laser beams (set in pairs, one for emitting horizontal laser beams and the other for receiving horizontal laser beams);

[0073] 21-Horizontal laser; 22-Rack; 23-Pressure sensor; 24-Limiting groove; 25-Right-angle limiting block. Detailed Implementation

[0074] As shown in the figure, the hardened concrete bubble spacing coefficient analyzer features automatic clamping and automatic focusing. The analyzer includes a control module and connected to it an automatic clamping system and an automatic focusing system. The automatic clamping system includes a stage 18 for placing a sample block 17, and multiple horizontal clamps 13 surrounding the stage. The sidewalls of the sample block are perpendicular to its top test surface. The front ends of the clamps are equipped with right-angle limiting blocks 25 that engage with the top and side surfaces of the sample block. The right-angle limiting blocks of the multiple clamps are at the same height. The stage is supported on a base 15 by a spherical connecting rod 19 and an elastic element 16, allowing the stage to swing within a threshold range. When clamping the sample block, the right-angle limiting blocks of the multiple clamps contact the top periphery of the sample block and limit the top surface and sidewalls of the sample block, keeping the top test surface of the sample block horizontal so that the automatic focusing system can focus on the test surface.

[0075] The right-angle limiting blocks of multiple clamps are of the same specification; the stage is rectangular, and the spherical connecting rod is located in the center of the stage; the elastic element is four springs located at the four corners of the stage. When the sample block is clamped, the springs press the stage against the clamped sample block.

[0076] The clamp is provided with a horizontal clamp rack 22, and the clamp is located in a limiting groove 24 for limiting the rotation of the clamp and can slide horizontally.

[0077] Four clamps are placed at the center of the four sides of a rectangular clamp frame 12. The clamp frame is supported on a base by base connecting rods 11 at its corners and surrounds the outside of the stage. A stepper motor assembly 14 is provided at the side of the clamp frame. The stepper motor assembly includes a stepper motor connected to the vertical rack of the base connecting rod and a stepper motor connected to the clamp rack. The stepper motor connected to the rack of the base connecting rod is used to drive the clamp frame to move up and down when clamping the sample block, and the stepper motor connected to the clamp rack is used to drive the clamp to move horizontally to extend and retract when clamping the sample block.

[0078] The right-angle limiting block is used to fix the clamping surface of the sample block and is equipped with a pressure sensing plate 23 connected to the control module. The pressure sensing plate is used to feed back the clamping force data of the fixture to the control module so that the control module can adjust the clamping stability of the fixture on the sample block.

[0079] The sample block can be in the shape of a cube or a cylinder. When the sample block is clamped, if the test surface at the top of the sample block has a slope, the stage rotates under the pressure of the right-angle limit block of the clamp to fit the bottom surface of the sample block in an inclined posture, so that the test surface at the top of the sample block is adjusted to a horizontal posture under the limit of the right-angle limit block.

[0080] The autofocus system is located above the automatic clamping system and includes a microscope lens 1 placed at the microscope tube 2. The microscope tube is connected to the microscope height adjustment thread 3 of the automatic microscope focusing system 8. A laser emitter 4 and a laser receiver 10 connected to the control module are provided on the side wall of the microscope tube. When autofocusing is performed, the reflected light of the ranging laser 5 emitted by the laser emitter at the laser ranging observation point on the test surface of the sample block is received by the laser receiver, so that the control module can obtain the height of the microscope tube relative to the test surface of the sample block and adjust this height so that the microscope focal point 7 coincides with the laser ranging observation point to complete focusing. After focusing is completed, the microscope begins to record the image of the test surface of the sample block.

[0081] The automatic microscope focusing system includes a microcontroller and a high-precision stepper motor SM; the high-precision stepper motor SM is connected to the microscope height adjustment thread via a gear set with a gear ratio of 400 to drive the microscope tube to rise and fall, and to finely adjust the height of the microscope tube relative to the test surface of the sample block.

[0082] The control module uses triangular laser ranging to measure the distance between the test surfaces of the sample block via a laser transmitter and a laser receiver.

[0083] The base is equipped with a laser beam transceiver device for roughly measuring the height of the test block; the laser beam transceiver device includes a pair of vertically arranged laser columns 20, which are arranged at equal intervals in the vertical direction with multiple laser transceiver positions, so that a horizontal laser beam 21 pointing to the test block at the stage is emitted or received at intervals, and the height of the lowest horizontal laser beam that is not blocked by the test block is used as the rough height of the test block.

[0084] The working process of the analyzer on the sample block includes the following steps;

[0085] Step S1, as follows Figure 7 As shown, the test surface of the sample block is placed upwards in the center of the stage, blocking the horizontal laser emitted by the base laser column; the height of the first blocked horizontal laser beam is taken as the approximate position height of the highest point of the unclamped sample block, and the laser is turned off; as shown... Figure 8 As shown, the stepper motor drives the fixture and fixture frame to automatically descend to the height of the lowest horizontal laser beam that is completely penetrating.

[0086] Step S2: Driven by the stepper motor group, the four clamps automatically begin to gradually move towards the center of the stage until all four clamps reach the edge of the test block.

[0087] Step S3, as follows Figure 9 As shown, the stepper motor assembly uses the base connecting rod as the force point, pressing down on the fixture frame, fixtures, and sample block, while the four fixtures begin to further converge towards the center; as... Figure 10 As shown, under the pressure of the right-angle limiting blocks of the four clamps, the top test surface of the test block is adjusted to a horizontal position, while the lower surface will press the stage to tilt. As the four clamps continue to close in, the test block is also clamped.

[0088] Step S4: After the control module senses that the clamping force of the four clamps is not lower than the threshold through the pressure sensor, the stepper motor group locks the clamps to complete the automatic clamping of the sample block.

[0089] Step S5: First, set the observation point on the test surface of the sample block as the starting point for the analyzer scanning. Then, adjust the microscope focus, lens height, and the height between the sample and the test piece to maintain the clearest field of view. The laser range sensor connected to the laser emitter and laser receiver measures the distance between itself and the observation point as the initial focal length. After the measurement is completed, turn off the laser and feed the data back to the automatic microscope focusing system.

[0090] Step S6: The microscope begins recording the image of the observation point, which serves as the analysis image at the starting point of the analyzer's scan;

[0091] Step S7: After the microscope has finished recording the image of the observation point, the stage moves the sample block and moves the scanning position of the sample block under the microscope to the next observation point on the test surface of the sample block.

[0092] Step S8: The distance sensor re-measures the distance between the next observation point on the test surface of the sample block and the microscope objective lens and feeds it back to the automatic microscope focusing system. The automatic microscope focusing system automatically calculates the current distance measurement data. If the current distance measurement data differs from the initial focal length data in step S5 by more than 0.05 mm, the microcontroller of the automatic microscope focusing system calculates and controls the stepper motor SM to drive the microscope height adjustment screw to rotate the corresponding number of turns, so that the microscope lens moves vertically, thereby moving the microscope focus to a height close to the initial focal length, thereby achieving the purpose of focusing.

[0093] Step S9: The microscope begins recording images of the new observation point;

[0094] Step S10: The stage moves the observation point of the specimen to the next point and repeats the above microscope focusing and image recording process.

[0095] In this example, the base can move horizontally along the XY coordinates, which in turn moves the stage to move the sample block, allowing the microscope to scan various areas of the sample block's test surface according to preset coordinates.

Claims

1. An automatic leveling and automatic focusing analyzer for the air bubble spacing coefficient of hardened concrete, characterized in that: The analyzer includes a control module and an automatic clamping system and an automatic focusing system connected thereto; the automatic clamping system includes a stage (18) for placing a sample block (17), and also includes multiple horizontal clamps (13) surrounding the stage; the sidewalls of the sample block are perpendicular to the test surface on its top; the front end of the clamps is provided with right-angle limiting blocks (25) that cooperate with the top and side surfaces of the sample block; the right-angle limiting blocks of the multiple clamps are located at the same height; the stage is supported on the base (15) by a ball joint (19) and an elastic element (16) so that the stage can swing within the threshold range; when clamping the sample block, the right-angle limiting blocks of the multiple clamps contact the top periphery of the sample block and limit the top surface and sidewalls of the sample block, so that the test surface on the top of the sample block remains horizontal so that the automatic focusing system can focus on the test surface. The right-angle limiting blocks of multiple clamps are of the same specification; the stage is rectangular, and the spherical connecting rod is located in the center of the stage; the elastic element is four springs located at the four corners of the stage. When clamping the sample block, the springs press the stage against the clamped sample block. The clamp is provided with a horizontal clamp rack (22), and the clamp is located in a limiting groove (24) for limiting the rotation of the clamp and can slide horizontally; There are four clamps, which are placed in the middle of the four sides of a rectangular clamp frame (12). The clamp frame is supported on the base by the base connecting rod (11) at its corner end and surrounds the outside of the stage. A stepper motor group (14) is provided at the side of the clamp frame. The stepper motor group includes a stepper motor connected to the vertical rack of the base connecting rod and a stepper motor connected to the clamp rack. The stepper motor connected to the rack of the base connecting rod is used to drive the clamp frame to move up and down when clamping the sample block. The stepper motor connected to the clamp rack is used to drive the clamp to move horizontally when clamping the sample block. The right-angle limiting block is used to fix the clamping surface of the sample block and is equipped with a pressure sensing plate (23) connected to the control module. The pressure sensing plate is used to feed back the clamping force data of the fixture to the control module so that the control module can adjust the clamping stability of the fixture on the sample block.

2. The automatic leveling and automatic focusing hardened concrete bubble spacing coefficient analyzer according to claim 1, characterized in that: The sample block can be in the shape of a cube or a cylinder. When the sample block is clamped, if the test surface at the top of the sample block has a slope, the stage rotates under the pressure of the right-angle limit block of the clamp to fit the bottom surface of the sample block in an inclined posture, so that the test surface at the top of the sample block is adjusted to a horizontal posture under the limit of the right-angle limit block.

3. The automatic leveling and automatic focusing hardened concrete bubble spacing coefficient analyzer according to claim 1, characterized in that: The autofocus system is located above the automatic clamping system and includes a microscope lens (1) placed at the microscope tube (2); the microscope tube is threadedly connected to the microscope height adjustment of the automatic microscope focusing system (8); a laser emitter (4) and a laser receiver (10) connected to the control module are provided on the side wall of the microscope tube. When autofocusing is performed, the reflected light of the ranging laser (5) emitted by the laser emitter at the laser ranging observation point on the test surface of the sample block is received by the laser receiver, so that the control module can obtain the height of the microscope tube relative to the test surface of the sample block and adjust this height so that the microscope focal point (7) coincides with the laser ranging observation point to complete the focusing. After the focusing is completed, the microscope begins to record the image of the test surface of the sample block.

4. The automatic leveling and automatic focusing hardened concrete bubble spacing coefficient analyzer according to claim 3, characterized in that: The automatic microscope focusing system includes a microcontroller and a high-precision stepper motor SM; the high-precision stepper motor SM is connected to the microscope height adjustment thread via a gear set with a gear ratio of 400 to drive the microscope tube to rise and fall, and to finely adjust the height of the microscope tube relative to the test surface of the sample block. The control module uses triangular laser ranging to measure the distance between the test surfaces of the sample block via a laser transmitter and a laser receiver.

5. The automatic leveling and automatic focusing hardened concrete bubble spacing coefficient analyzer according to claim 3, characterized in that: The base is provided with a laser beam transceiver device for roughly measuring the height of the test block; the laser beam transceiver device includes a pair of vertically arranged laser columns (20), which are arranged at equal intervals in the vertical direction with multiple laser transceiver positions, so that a horizontal laser beam (21) pointing to the test block at the stage is emitted or received at intervals, and the height of the lowest horizontal laser beam that is not blocked by the test block is used as the rough height of the test block.

6. The automatic leveling and automatic focusing hardened concrete bubble spacing coefficient analyzer according to claim 5, characterized in that: The working process of the analyzer on the sample block includes the following steps; Step S1: Place the test surface of the sample block upwards in the middle of the stage to block the horizontal laser emitted by the base laser column; The height of the first blocked horizontal laser beam is taken as the approximate position height of the highest point of the unclamped sample block, and the laser is turned off; the stepper motor group drives the fixture and fixture frame to automatically descend to the height of the lowest horizontal laser beam that is completely penetrating. Step S2: Driven by the stepper motor group, the four clamps automatically begin to gradually move towards the center of the stage until all four clamps reach the edge of the test block. Step S3: The stepper motor assembly uses the base connecting rod as the force point to press down the clamp frame, clamp and sample block, while the four clamps begin to surround the center. At this time, under the pressure of the right angle limit blocks of the four clamps, the test surface of the top of the sample block is adjusted to a horizontal position, while the lower surface will press the stage to tilt. As the four clamps continue to surround the sample block, the sample block is also clamped. Step S4: After the control module senses that the clamping force of the four clamps is not lower than the threshold through the pressure sensor, the stepper motor group locks the clamps to complete the automatic clamping of the sample block. Step S5: First, set the observation point on the test surface of the sample block as the starting point for the analyzer scanning. Then, adjust the microscope focus, lens height, and the height between the sample and the test piece to maintain the clearest field of view. The laser range sensor connected to the laser emitter and laser receiver measures the distance between itself and the observation point as the initial focal length. After the measurement is completed, turn off the laser and feed the data back to the automatic microscope focusing system. Step S6: The microscope begins recording the image of the observation point, which serves as the analysis image at the starting point of the analyzer's scan; Step S7: After the microscope has finished recording the image of the observation point, the stage moves the sample block and moves the scanning position of the sample block under the microscope to the next observation point on the test surface of the sample block. Step S8: The distance sensor re-measures the distance between the next observation point on the test surface of the sample block and the microscope objective lens and feeds it back to the automatic microscope focusing system. The automatic microscope focusing system automatically calculates the current distance measurement data. If the current distance measurement data differs from the initial focal length data in step S5 by more than 0.05 mm, the microcontroller of the automatic microscope focusing system calculates and controls the stepper motor SM to drive the microscope height adjustment screw to rotate the corresponding number of turns, so that the microscope lens moves vertically, thereby moving the microscope focus to a height close to the initial focal length, thereby achieving the purpose of focusing. Step S9: The microscope begins recording images of the new observation point; Step S10: The stage moves the observation point of the specimen to the next point and repeats the above microscope focusing and image recording process.

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