A laser scanning device based on point cloud data

Abstract

The application discloses a kind of based on point cloud data's limit detection method and its laser scanning device, including scanner body and underframe, the top of underframe is fixed with the top seat for scanner body installation, underframe includes stand and support foot, the top of stand is fixedly connected with top seat, support foot is symmetrically set in the bottom end of stand, one end of support foot is hinged on stand, the bottom end lateral wall of stand is provided with the storage groove for the overturning of support foot and being received, lifting seat is vertically connected on stand and is lifted, the bottom of lifting seat is provided with walking wheel for walking movement, support foot can support the whole equipment to realize fixed-point scanning detection, when encountering tunnel, the use occasion of the detection length is longer, lifting seat is lowered until walking wheel is in contact with ground, lifting seat drives support foot to be received in storage groove, walking wheel realizes the walking of equipment, can be well applicable to the occasion that scanning detection area is longer, realize the switching of working state, effectively improve applicability and universality.

Description

Technical Field

[0001] This invention relates to the field of clearance detection, and in particular to a laser scanning device based on point cloud data. Background Technology

[0002] Tunnel clearance inspection refers to the process of monitoring and evaluating whether the internal dimensions, structural outline, and equipment installation locations of a tunnel meet design specifications or safe operation requirements through technical means. Its core purpose is to ensure the safety of vehicles and pedestrians passing through the tunnel, as well as the normal operation of equipment and facilities, and to prevent accidents such as collisions and scrapes caused by insufficient clearance.

[0003] Clearance inspection mainly uses a ground-based 3D laser scanner to acquire track point cloud data. Based on the 3D point cloud, cross-sectional information is extracted, and then the track clearance is analyzed. Therefore, the 3D laser scanner is the main data acquisition instrument for clearance inspection. Currently, the 3D laser scanner mainly consists of a scanner body at the top and a support at the bottom, which is usually supported by a tripod.

[0004] A search revealed that Chinese Patent CN216385488U discloses a 3D laser scanner that avoids stray light interference. The scanner includes a fixed base, a drive panel, and a scanner body. A movable base is movably mounted on the top of the fixed base, and a scanner body is mounted on the top of the movable base. A drive panel is mounted on one side of the scanner body, and rotating shafts are symmetrically and movably mounted on the inner side of the scanner body. A scanning head is mounted on the inner side of the scanner body via the rotating shafts. A fixing groove is formed on the front of the scanning head, and a first magnetic sheet is mounted on the inner wall of the back of the fixing groove. A mounting groove is formed on the front of the scanner body. By fixing a light shield inside the fixing groove, the light shield serves to block light, preventing external stray light from interfering with the scanning head and allowing the scanning head to scan the object more accurately.

[0005] In practical use, the aforementioned 3D laser scanner is generally only suitable for fixed-point use. That is, when the area to be inspected is not long, it can be used by transporting it to the corresponding inspection point. However, when encountering long inspection routes such as tunnel inspection, there are inconveniences in use and transportation, resulting in insufficient applicability and versatility, which need to be further improved. Summary of the Invention

[0006] To further improve applicability and versatility, this application provides a boundary detection method based on point cloud data and a laser scanning device thereof.

[0007] This application provides a laser scanning device based on point cloud data, which adopts the following technical solution:

[0008] A laser scanning device based on point cloud data includes a scanner body and a base frame. The top of the base frame is fixed with a top mount for mounting the scanner body. The base frame includes a column and support legs. The top of the column is connected and fixed to the top mount. The support legs are symmetrically arranged at the bottom of the column. One end of the support leg is hinged to the column. The bottom side wall of the column has a storage groove for the support legs to be flipped and retracted. A lifting seat is vertically and vertically connected to the column. The bottom of the lifting seat is provided with wheels for walking and moving.

[0009] Optionally, the top seat is provided with a drive source for driving the lifting seat to move vertically. The drive source includes a vertically arranged hydraulic cylinder, the cylinder body of which is fixed on the top seat, and the piston rod end of which is fixed on the lifting seat.

[0010] Optionally, a compression spring is provided in the storage slot, which is used to drive the support foot to flip out of the storage slot.

[0011] Optionally, the surface of the support leg is flush with the surface of the column after it is retracted into the storage groove.

[0012] Optionally, the lifting seat has a central hole through which the column passes, and the inner wall of the central hole is provided with a scraper ring for contacting the surface of the column.

[0013] Optionally, multiple scraper rings are arranged at vertical intervals along the column, and the scraper rings are in line contact with the surface of the column.

[0014] Optionally, the scraper ring has vertical through holes, and multiple through holes are evenly distributed.

[0015] Optionally, the walking wheel is located on the flipping path of the support foot, and the support foot flips outward and abuts against the walking wheel to achieve the travel limit of the flipping.

[0016] Optionally, the top end of the column is threadedly connected to the top seat, and the bottom end of the column is threadedly connected to a center, the bottom end of which is tapered.

[0017] This application also provides a boundary detection method using the above-mentioned laser scanning device based on point cloud data, comprising the following steps:

[0018] S1, uses a laser scanning device to scan and acquire point cloud data of the tunnel;

[0019] S2, Generate a cross-sectional view of the tunnel based on the point cloud data;

[0020] S3, obtain the boundary parameters of the subway and generate the boundary map of the subway;

[0021] S4. Compare the boundary diagram with the cross-sectional diagram to determine the boundary encroachment situation.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. The support feet at the bottom of the base frame can support the entire equipment to achieve fixed-point scanning and detection. When encountering applications with long detection lengths, such as tunnels, the lifting seat is driven to move down until the traveling wheels contact the ground. The moving lifting seat drives the support feet to flip and retract into the storage slot. At this time, the traveling wheels at the bottom of the lifting seat can enable the entire equipment to move. At the same time, the traveling wheels can be used with the guide rails laid in the tunnel for movement, making the equipment well-suited for applications with long scanning and detection areas. This achieves the switching between two different working states, and the switching operation is simple and convenient, effectively improving applicability and versatility. Furthermore, after lowering, the lifting seat simultaneously achieves the flipping limit of the support feet, preventing the support feet from flipping outward.

[0024] 2. The traveling wheels are located on the flipping path of the support foot and are used to abut against it. The traveling wheels can limit the angle of the flipped support foot to prevent the support foot from flipping out excessively. At the same time, the lifting height adjustment of the lifting seat can drive the support foot to flip at different angles, and simultaneously realize the adjustment of the flipping angle of the support foot, realizing the multi-purpose of the traveling wheels.

[0025] 3. The scraper ring on the lifting platform can scrape off impurities or dirt adhering to the surface of the column and support feet during the vertical lifting process, reducing the frequency of subsequent cleaning of the base frame. The perforations on the scraper ring allow the scraped impurities to fall through.

[0026] 4. The compression spring setting enables the automatic reset of the outward-folded support foot, eliminating the need for manual operation of the support foot. Furthermore, due to the elasticity of the compression spring, during the downward movement of the lifting seat, the compression spring always drives the surface of the support foot to be in close contact with the scraping ring, thereby maintaining a good scraping effect. Attached Figure Description

[0027] Figure 1 This is a cross-sectional view of Example 1.

[0028] Figure 2 This is a structural diagram of the lifting seat after it has been lowered in Example 1.

[0029] Figure 3 This is a cross-sectional view of Example 2.

[0030] Figure 4 This is a partial view of the bottom of the column in Example 2.

[0031] Figure 5 This is a flowchart of Example 3.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Scanner body; 2. Base frame; 3. Top mount; 4. Universal pan / tilt head; 5. Column; 6. Support legs; 7. Hinge shaft; 8. Storage slot; 9. Lifting seat; 10. Wheels; 11. Drive source; 12. Compression spring; 13. Slot; 14. Center hole; 15. Scraper ring; 16. Perforation; 17. Vertical slot; 18. Center point; 19. Airbag; 20. Top rod; 21. Drive end; 22. Air vent; 23. Cutting slit. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-5 This application will be described in further detail. Example

[0035] A laser scanning device based on point cloud data, such as Figure 1 and Figure 2 As shown, the device includes a scanner body 1 and a base frame 2. A top mount 3 for mounting the scanner body 1 is fixed on the top of the base frame 2. A pan-tilt head 4 is provided on the top mount 3. The scanner body 1 is fixedly mounted on the pan-tilt head 4. By rotating the pan-tilt head 4, the scanner body 1 can scan and acquire point cloud data in various directions of the tunnel. The base frame 2 includes a column 5 and support legs 6. The column 5 is vertically arranged and its top is connected to the top mount 3. The support legs 6 are symmetrically arranged at the bottom of the column 5 to support it. In this embodiment, four support legs 6 are selected and symmetrically located in the four directions of the column 5. The top of the support legs 6 is hinged to the column 5 through a hinge shaft 7. A storage groove 8 is provided on the bottom side wall of the column 5 for the support legs 6 to be flipped and retracted. The bottom of the storage groove 8 penetrates the bottom of the column 5. In this way, when the device is not in use, the support legs 6 can be flipped and retracted into the storage groove 8 to reduce the space occupied.

[0036] like Figure 1 and Figure 2 As shown, a lifting seat 9 is vertically connected to the column 5. The bottom end of the lifting seat 9 is symmetrically provided with walking wheels 10 for movement. At the same time, a drive source 11 is provided on the top seat 3 to drive the lifting seat 9 to move vertically. The drive source 11 includes a vertically arranged hydraulic cylinder. The top of the cylinder body is fixed to the top seat 3, and the bottom end of the piston rod of the hydraulic cylinder is fixed to the lifting seat 9. In this embodiment, the drive source 11 is symmetrically arranged on both sides of the column 5, thereby achieving balance and stability in driving the lifting seat 9 to move vertically.

[0037] By driving the lifting seat 9 to rise and fall, the device can be quickly switched between different usage states. In actual use, the lifting seat 9 is kept above the support leg 6, and the support leg 6 is flipped to a tilted state to support the column 5, enabling the device to perform fixed-point scanning detection. This is suitable for detection applications with short distances. Only a few fixed detection points need to be set, and then the device can be moved to each detection point in sequence for use. See [link to relevant documentation]. Figure 1In situations involving long tunnels, the lifting platform 9 is lowered via the drive source 11. During this descent, the supporting legs 6 are simultaneously rotated inwards until the entire structure is retracted into the storage slot 8. The lifting platform 9 moves until its wheels 10 contact the ground, at which point the supporting legs 6 no longer touch the ground. This allows the entire device to move using the wheels 10, or it can be adapted to the tracks laid in the tunnel for movement. Workers only need to push the equipment to achieve continuous scanning, eliminating the need for constant equipment handling, making the process easier and less strenuous. (See also...) Figure 2 In other embodiments, a drive motor that drives the walking wheels 10 to rotate can also be provided on the lifting seat 9 to realize the automatic walking of the entire device.

[0038] This allows for switching between two different working states, and the switching operation is simple and convenient, effectively improving applicability and versatility. After lowering, the lifting seat 9 simultaneously achieves the flip limit of the support leg 6, preventing the support leg 6 from flipping outward. At the same time, driving the lifting seat 9 to rise and stop at different heights of the column 5 can achieve different degrees of outward flipping of the support leg 6, effectively adjusting the outward flipping angle of the support leg 6 to meet the needs of more occasions. Moreover, this adjustment method can be achieved without additional parts.

[0039] like Figure 1 As shown, a compression spring 12 is installed in the storage slot 8. The compression spring 12 is used to drive the support leg 6 to flip outward and reset. With the help of the compression spring 12, when the lifting seat 9 moves up to the point where it no longer limits the support leg 6, the support leg 6 will automatically flip outward under the action of the compression spring 12, saving the manual operation of flipping outward and making it more convenient. A groove 13 is provided on the bottom wall of the storage slot 8 for the compression spring 12 to be installed and accommodated. One end of the compression spring 12 is fixed to the inner wall of the groove 13, and the other end is fixed to the support leg 6. After the support leg 6 is completely stored in the storage slot 8, the compression spring 12 can be completely stored in the groove 13.

[0040] like Figure 1 and Figure 2 As shown, after the support leg 6 is fully retracted into the storage slot 8, the surface of the support leg 6 is flush with the outer surface of the column 5, which makes the surface of the column 5 have better integrity and consistency after storage. A central hole 14 is opened in the center of the lifting base 9 for the column 5 to pass through. The lifting base 9 has a scraper ring 15 protruding inside the central hole 14 for contacting the surface of the column 5. Since dirt and other impurities are easily adhered to the surface of the column 5 and support leg 6 during outdoor use, the scraper ring 15 can simultaneously scrape off dirt and impurities from the surface of the column 5 and support leg 6 during the process of driving the lifting base 9 to rise and fall to switch the use state. This reduces the need for subsequent cleaning of the base frame 2 and automatically removes the adhering dirt and impurities.

[0041] like Figure 1 As shown, multiple scraper rings 15 are distributed at intervals along the axial direction of the central hole 14. In this embodiment, three scraper rings 15 are provided. During the lifting process of the lifting seat 9, each scraper ring 15 can achieve multiple scraping functions. Furthermore, the scraper rings 15 are in line contact with the surface of the column 5, thereby achieving a better scraping effect. The line contact method can also reduce frictional resistance, making it easier for the lifting seat 9 to lift and lower vertically more smoothly. In addition, combined with the force of the compression spring 12 in the storage groove 8, the elastic force of the compression spring 12 always drives the support foot 6 to have an outward tendency. This ensures that the surface of the support foot 6 and the scraper ring 15 always maintain a good contact effect, further guaranteeing the scraping effect.

[0042] like Figure 1 As shown, a through hole 16 is vertically opened on the scraper ring 15. Multiple through holes 16 are evenly distributed around the circumference of the scraper ring 15. The through holes 16 are used to allow soil and impurities to pass through. In this way, when the soil and impurities to be scraped are located above the scraper ring 15, these soil and impurities can fall off through the through holes 16, reducing the need for manual cleaning.

[0043] like Figure 1 and Figure 2 As shown, the traveling wheel 10 is located on the flipping path of the support leg 6. After the support leg 6 flips outward under the elastic force of the compression spring 12, the support leg 6 abuts against the traveling wheel 10 to achieve the travel limit of the outward flipping. The traveling wheel 10 can limit the outward flipping angle of the support leg 6 to avoid the support leg 6 flipping outward too much and affecting stability. In addition, combined with the adjustment of the height of the lifting seat 9, the height of the supporting leg 6 can be controlled and adjusted synchronously with the traveling wheel 10. Thus, the support leg 6 can be adjusted to the appropriate outward flipping angle according to different usage scenarios, which can meet the usage needs of more occasions.

[0044] like Figure 1 and Figure 2 As shown, when the traveling wheel 10 moves after contacting the ground, the bottom of the support foot 6 is usually kept out of contact with the ground to improve the smoothness of movement and prevent the support foot 6 from affecting the smoothness of movement. When it is necessary to keep the equipment stationary after moving to the detection position, the lifting seat 9 and the traveling wheel 10 can be driven to move upwards to keep the traveling wheel 10 and the support foot 6 in contact with the ground synchronously. At this time, the support foot 6 can play an auxiliary support and positioning role, which can better keep the entire device stationary.

[0045] like Figure 1As shown, the top of the column 5 is threadedly connected to the top seat 3 to achieve detachment. The column 5 and the top seat 3 can be manufactured separately and independently, reducing structural complexity and manufacturing difficulty. At the same time, it can also reduce the space occupied during packaging. In addition, the overall height can be adjusted by rotating the column 5 during actual use, thereby meeting the needs of more occasions and improving practicality.

[0046] like Figure 1 As shown, a vertical groove 17 is provided at the bottom of the column 5. A tip 18 is threaded into the vertical groove 17. The bottom of the tip 18 is conical. The vertical groove 17 can accommodate the tip 18. When the support leg 6 is in the outward use state, the bottom of the tip 18 is kept outside the column 5. The tip 18 can be inserted into the soil for further auxiliary positioning and fixation. When the support leg 6 is in the retracted use state, the tip 18 can be rotated to be stored in the vertical groove 17. Example

[0047] A laser scanning device based on point cloud data, such as Figure 3 and Figure 4 As shown, the difference from Embodiment 1 is that an airbag 19 is provided inside the bottom end of the column 5, and a top rod 20 is horizontally slidably connected to the inner wall of the storage groove 8. One end of the top rod 20 abuts against the airbag 19, and the other end of the top rod 20 forms a driving end 21 inside the storage groove 8. In addition, multiple air vents 22 are opened on the outer wall of the bottom end of the column 5. The positions of the air vents 22 are staggered from the positions of the storage groove 8 on the column 5. A slit 23 is opened on the airbag 19 corresponding to the air vents 22. The slit 23 is linear. In this way, when the lifting seat 9 moves down to drive the support leg 6 into the storage groove 8, the support leg 6 drives the top rod 20 to move horizontally inward. After the airbag 19 is squeezed, the gas inside the airbag 19 will pass through the slit 23. 3. The air is discharged and finally blown out through the air outlet 22. The air outlet 22 can blow off the impurities scraped off by the scraper ring 15, so that the scraped impurities can fall more easily through the perforation 16, reducing the phenomenon of impurities remaining on the scraper ring 15. The linear slit 23 can be kept closed under normal circumstances to prevent external impurities from entering. An air replenishment device can also be connected to the airbag 19, so that the airbag 19 can be used continuously for a long time. In other embodiments, an air outlet can be set at the air outlet 22 corresponding to the air outlet of the airbag 19, and a one-way valve can be set at the air outlet, so that other things inside the airbag 19 can only be discharged and cannot enter, thereby realizing the blowing to clean impurities while preventing impurities from entering the airbag 19 through the air outlet. Example

[0048] A boundary detection method based on point cloud data employs the laser scanning device described in Example 1, such as... Figure 5 As shown, it mainly includes the following steps:

[0049] S1, the point cloud data of the tunnel is obtained by scanning with the laser scanning device of Example 1.

[0050] Switch the laser scanning device to the state where the walking wheel 10 is in contact with the ground, move the laser scanning device to collect road cross-section information and track cross-section information, and obtain point cloud dataset.

[0051] S2 generates a cross-sectional view of the tunnel based on point cloud data.

[0052] S3: Obtain the boundary parameters of the subway and generate the boundary map of the subway.

[0053] By setting up multiple laser cameras around the train to obtain a 3D outline of the train, and then stitching it together using 3D stitching technology, a boundary map of the train is obtained.

[0054] S4. Compare the boundary diagram with the cross-sectional diagram to determine the boundary encroachment situation.

[0055] If boundary encroachment occurs during the comparison process, pipeline equipment adjustments or line / slope adjustments will be required.

[0056] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A laser scanning device based on point cloud data, comprising a scanner body (1) and a base frame (2), characterized in that: The top of the base frame (2) is fixed with a top seat (3) for mounting the scanner body (1). The base frame (2) includes a column (5) and support legs (6). The top of the column (5) is connected and fixed to the top seat (3). The support legs (6) are symmetrically arranged at the bottom of the column (5). One end of the support leg (6) is hinged to the column (5). The bottom side wall of the column (5) is provided with a storage groove (8) for the support leg (6) to be flipped and retracted. A lifting seat (9) is vertically connected to the column (5). The bottom of the lifting seat (9) is provided with a walking wheel (10) for walking. The top seat (3) is provided with a drive source (11) for driving the lifting seat (9) to move vertically. The drive source (11) includes a vertically arranged hydraulic cylinder. The cylinder body of the hydraulic cylinder is fixed to the top seat (3). The piston rod end of the hydraulic cylinder is fixed to the lifting seat (9). Above; a compression spring (12) is provided in the storage groove (8), the compression spring (12) is used to drive the support foot (6) to flip out and leave the storage groove (8); after the support foot (6) is put into the storage groove (8), its surface is flush with the surface of the column (5); the center of the lifting seat (9) is provided with a central hole (14) for the column (5) to pass through, and the inner wall of the central hole (14) is provided with a scraper ring (15) for contacting the surface of the column (5); multiple scraper rings (15) are arranged at intervals along the vertical direction of the column (5), and the scraper rings (15) are in line contact with the surface of the column (5); a vertical through hole (16) is provided on the scraper ring (15), and multiple through holes (16) are evenly distributed; the walking wheel (10) is located on the flipping path of the support foot (6), and the support foot (6) is flipped out and abuts against the walking wheel (10) to achieve the stroke limit of the flipping.

2. The laser scanning device based on point cloud data according to claim 1, characterized in that: The top of the column (5) is threadedly connected to the top seat (3), and the bottom of the column (5) is threadedly connected to a tip (18), the bottom of which is tapered.

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