Pressure vessel shape deviation detection device and detection method based on laser scanning

Abstract

The invention relates to the technical field of shape deviation detection, in particular to a pressure vessel shape deviation detection device and method based on laser scanning, the pressure vessel shape deviation detection device comprises a handheld laser 3D scanner and further comprises a frame body, the side, close to a vessel tank, of the frame body is detachably connected with the scanner, and equidistant assemblies are symmetrically installed on the frame body; the ends of the two equidistant assemblies are in contact with the surface of the container tank, the two equidistant assemblies and the scanner form a triangle, and laser emitted by the scanner is perpendicular to the midpoints of the two equidistant assemblies; the ends of the two rotating pieces are attached to the peripheral face of the container tank, it is guaranteed that the distance between the scanner and the container tank is not changed, meanwhile, it can be guaranteed that the central axis of the container tank, the generatrix of the container tank and the path of laser emitted by the scanner are located on the same plane, and therefore the problem that in the prior art, due to distance measurement and scanning angle changes, the scanning precision is poor is solved. And the cylindrical container tank part is not scanned, so that repeated scanning is needed.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shape deviation detection, and particularly relates to a laser scanning pressure container shape deviation detection device and a detection method. BACKGROUND

[0002] In the manufacturing process of pressure containers, manufacturing enterprises will encounter various deformation problems, mainly including two categories: the first category is deformation caused by stress, and the second category is deformation caused by human error. There is a difference between the actual shape of the processed part and the designed shape, which is shape deviation.

[0003] The core principle of laser scanning pressure container shape detection is to emit a laser pulse and receive a reflected signal, calculate the round-trip time of the laser beam by using the Time of Flight method or the phase difference method, and thus determine the distance between the scanner and the target surface. In combination with the rotating mirror of the scanner and the angle encoder, the three-dimensional coordinates (X, Y, Z) of the object surface are calculated to obtain container shape data, and finally high-density point cloud data is generated. After processing, these point cloud data can construct a three-dimensional model of the device.

[0004] The laser scanning precision is affected by both the distance and the scanning angle, especially for cylindrical objects. Figure 8 and Figure 9 As shown in the drawings, when the operator holds the handheld laser 3D scanner to scan the cylindrical container, since the surface of the container is arc-shaped, if the scanning angle deviates, that is, it is not perpendicular to the arc-shaped surface, it is difficult to receive the emitted laser. In addition, since it is a handheld device for scanning, it is inevitable to approach and move away from the container, and it is difficult to guarantee a constant required distance, which will cause scanning errors. Therefore, multiple repeated scanning is required, which is troublesome.

[0005] The above information disclosed in the background section is only used to strengthen the understanding of the background of the present disclosure, and therefore it can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The purpose of the present application is to design a laser scanning pressure container shape deviation detection device that can guarantee that the operator can guarantee fixed distance measurement when using a handheld laser 3D scanner, and the scanning angle is always perpendicular to the surface of the container, in order to solve the above problems in the art.

[0007] In order to achieve the above object, the present application provides the following technical scheme: a laser scanning pressure vessel shape deviation detection device for vertical container tank detection, comprising a handheld laser 3D scanner, further comprising a frame, the frame is detachably connected with the scanner near one side of the container tank, the frame is symmetrically installed with equidistant components, the end of the two equidistant components is in contact with the surface of the container tank, the two equidistant components and the scanner form a triangle, and the laser emitted by the scanner is perpendicular to the midpoint of the two equidistant components. By the fact that the end of the two rotating members is in contact with the outer circumferential surface of the container tank, the distance between the scanner and the container tank can be ensured unchanged, and the central axis of the container tank, the generatrix of the container tank and the path of the laser emitted by the scanner are in the same plane.

[0008] Preferably, the equidistant component comprises a first shaft rotatably installed on the frame, a swing rod rotatably installed on the first shaft, a second shaft rotatably installed at the end of the swing rod, a connecting rod rotatably installed on the second shaft, and a transmission member for controlling the included angle between the swing rod and the connecting rod and the frame, when the included angle between the two swing rods increases, the included angle between the swing rod and the connecting rod decreases.

[0009] Preferably, the transmission member comprises a first gear fixedly installed on the first shaft, a second gear rotatably installed on the second shaft, two third shafts rotatably installed on the frame, a driving wheel rotatably installed on the third shaft, a driven wheel fixedly installed on the connecting rod, and a rack slidably installed on the swing rod, the first gear is engaged with the driving wheel, the second gear is engaged with the driven wheel, the first gear and the second gear are engaged with the rack, and the first gear is fixedly connected with the top surface of the swing rod.

[0010] Preferably, the transmission member further comprises a worm rotatably installed on the frame, and a worm wheel engaged with one side of the worm, and one of the third shafts is fixedly connected with the worm wheel.

[0011] Preferably, a rolling member is rotatably installed at the end of the connecting rod, the central axis of the rolling member is parallel to the central axis of the container tank, the generatrix of the rolling member is in the same straight line as the generatrix of the container tank, and the diameter of the rolling member is greater than the width of the connecting rod.

[0012] Preferably, a guide frame is fixedly installed at the bottom of the connecting rod, a wax strip with matte powder is slidably installed in the guide frame, a positioning sheet is fixedly installed at the bottom of the connecting rod, a spring is detachably installed on the positioning sheet, and the end of the spring is in contact with the end of the wax strip.

[0013] Preferably, the rack can be replaced by an odd number of transmission gears engaged with each other, and the odd number of transmission gears are engaged with the first gear and the second gear, respectively.

[0014] Preferably, a knob is fixedly installed at the end of the worm, and two handles are fixedly installed on the frame.

[0015] In a second aspect, the application also provides a detection method for operating the laser scanning pressure vessel shape deviation detection device to detect, comprising the following steps: S1: install the scanner on the frame body to ensure that the container tank central axis, the container tank generatrix and the path of the laser emitted by the scanner are in the same plane; S2: make the outer circumferential surface of the two rolling members adhere to the outer circumferential surface of the container tank, and rotate the knob forward or reversely according to the angle of the laser emitted by the scanner and the laser received to adjust the distance between the scanner and the container tank to ensure that the laser emitted by the scanner can be received; S3: start the scanner and hold the handle, drive the scanner to scan around the outer circumferential surface of the container tank under the premise that the rolling members completely adhere to the outer surface of the container tank, then lift the device as a whole by a part, and then drive the scanner to scan around the container tank reversely, and repeat until the cylindrical part of the container tank is scanned out; S4: during this period, the rolling members will contact the wax strip to form a matte strip on the surface of the container tank, and the sudden thinning of the matte strip indicates that the pushing and scanning process has deviated, which can be moved reversely to scan again to avoid missing scanning or scanning distortion.

[0016] In the above technical solution, the application provides the following technical effects and advantages: The equal distance assembly and the rolling members are provided to ensure that the distance between the scanner and the container tank remains unchanged, and the container tank central axis, the container tank generatrix and the path of the laser emitted by the scanner are in the same plane, thereby solving the problem that the cylindrical part of the container tank is not scanned out due to changes in the distance and scanning angle in the prior art, and the problem of repeated scanning is solved. The knob can be rotated forward or reversely to quickly adjust the distance between the container tank and the scanner, so as to be suitable for different diameters and different types of scanners. When the distance between the container tank and the scanner is adjusted to be larger, the distance between the contact parts of the two rolling members and the container tank will be larger, which can prevent the scanner from scanning the rolling members together due to the larger distance between the scanner and the container tank. The application can also observe the width change of the track left by the rolling members on the container tank in real time during scanning, and the width change indicates that there is no deviation, and the width change indicates that there is a deviation. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0018] Figure 1 is a schematic diagram of the use state of the present application; Figure 2 is a schematic diagram of the overall structure of the present application; Figure 3 is a perspective view of the present application; Figure 4 is a schematic diagram of the scanning angle deflection of the present application; Figure 5 is a schematic diagram of the normal distance between the scanner and the container can of the present application; Figure 6 is a schematic diagram of the distance between the scanner and the container can of the present application becoming shorter; Figure 7 is a schematic diagram of the distance between the scanner and the container can of the present application becoming longer; Figure 8 is a schematic diagram of the comparison between the deflection and the normal condition of the scanner of the present application; Figure 9 is a schematic diagram of the comparison between the distance variation between the scanner and the container can of the present application.

[0019] Explanation of reference numerals: 1, container can; 2, scanner; 3, frame body; 4, equidistance assembly; 4a, first shaft; 4b, swing rod; 4c, second shaft; 4d, connecting rod; 4e, transmission member; 4e1, first gear; 4e2, second gear; 4e3, third shaft; 4e4, driving wheel; 4e5, driven wheel; 4e6, rack; 4e7, worm; 4e8, worm wheel; 5, rolling member; 6, guide frame; 7, wax strip; 8, positioning sheet; 9, spring; 10, knob; 11, handle. DETAILED DESCRIPTION

[0020] In order for those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0021] In order to better understand the above technical solutions, the above technical solutions will be described in detail below in combination with the drawings in the specification and specific embodiments.

[0022] The present application provides a device for scanning a container can, which comprises a frame body, a scanner and an equidistance assembly. Figures 1-9The device shown is a laser scanning pressure vessel shape deviation detection device for detecting vertical container tanks 1. It includes a handheld laser 3D scanner 2 (as in the prior art) and a frame 3. The frame 3 is detachably connected to the scanner 2 near the container tank 1. Two symmetrically distributed first shafts 4a are rotatably mounted on the frame 3. A swing arm 4b is rotatably mounted on the first shaft 4a. A second shaft 4c is rotatably mounted at the end of the swing arm 4b. A connecting rod 4d is rotatably mounted on the second shaft 4c. A control swing arm 4b, connecting rod 4d, and frame 3 are also mounted on the swing arm 4b, the connecting rod 4d, and the frame 3. The transmission component 4e, which forms an angle between the lever 4b and the connecting rod 4d and the frame 3, together constitutes the equidistant assembly 4. When the angle between the lever 4b, the connecting rod 4d, and the frame 3 remains constant, if the ends of both equidistant assemblies 4 are in contact with the surface of the container 1, then the two contacting parts and the scanner 2 will form a triangle. This ensures that the laser emitted by the scanner 2 is perpendicular to the midpoint of the two equidistant assemblies 4, thus ensuring that the central axis of the container 1, the generatrix of the container 1, and the path of the laser emitted by the scanner 2 are in the same plane, avoiding any... Figure 8 The issue of needing to scan repeatedly due to scanning angle problems does not occur. Furthermore, because of the presence of the triangle and the fact that both ends of the equidistant component 4 remain in contact with the surface of container 1, the distance between the scanner 2 and the surface of container 1 will be fixed, preventing problems. Figure 9 The problem shown; To make this device applicable to containers 1 of different sizes, the transmission component 4e includes a first gear 4e1 fixedly mounted on a first shaft 4a, a second gear 4e2 rotatably mounted on a second shaft 4c, two third shafts 4e3 rotatably mounted on the frame 3, a driving wheel 4e4 rotatably mounted on the third shafts 4e3, a driven wheel 4e5 fixedly mounted on the connecting rod 4d, and a rack 4e6 slidably mounted on the rocker arm 4b. The first gear 4e1 meshes with the driving wheel 4e4, the second gear 4e2 meshes with the driven wheel 4e5, and both the first gear 4e1 and the second gear 4e2 mesh with the rack 4e6. The first gear 4e1 is fixedly connected to the top surface of the rocker arm 4b. Thus, the rotation of the driving wheel 4e4 drives the first gear 4e1 to rotate clockwise. The first gear 4e1 drives the rocker arm 4b to rotate on the frame 3, increasing the angle between the rocker arm 4b and the frame 3. Simultaneously, the first gear 4e1 drives the rack 4e6 to slide, and the rack 4e6 drives the second gear 4e2 to rotate. The second gear 4e2, through meshing with the driven wheel 4e5, drives the driven wheel 4e5 to rotate around the central axis of the second shaft 4c, thereby driving the connecting rod 4d to rotate on the rocker arm 4b, reducing the distance between the adjusting connecting rod 4d and the rocker arm 4b, forming a... Figure 5 Length Figure 6 By reducing the distance between container 1 and scanner 2, and by rotating the drive wheel 4e4 in the opposite direction, the angle between the swing arm 4b and the frame 3 can be reduced, while the angle between the swing arm 4b and the connecting rod 4d can be increased, forming a shape like... Figure 5 ChangeFigure 7 The distance between the container tank 1 and the scanner 2 is increased, so that the distance can be freely adjusted according to the size of the container tank 1 and the model of the scanner 2, and as shown in Figure 5 、 Figure 6 and Figure 7 When the scanner 2 is far away from the container tank 1, the distance between the two end portions of the equidistant assembly 4 in contact with the container tank 1 is increased, and the mis-scanning of the end portion of the equidistant assembly 4 can be avoided when the scanning area is increased after the scanner 2 is far away from the container tank 1; In order to ensure the functions of easy adjustment and self-locking, the transmission member 4e further comprises a worm 4e7 rotatably installed on the frame 3, and a worm gear 4e8 engaged with one side of the worm 4e7, wherein one third shaft 4e3 is fixedly connected with the worm gear 4e8, and a knob 10 is fixedly installed at the end of the worm 4e7, and the worm gear 4e8 is only driven to rotate when the knob 10 drives the worm 4e7 to rotate, and the worm gear 4e8 drives the driving wheel 4e4 to rotate through the third shaft 4e3, and the worm gear 4e8 cannot drive the worm 4e7 to rotate, thereby realizing the self-locking function, and two handles 11 are fixedly installed on the frame 3, which facilitates the operator to move the whole device; In order to reduce the friction between the swing assembly and the surface of the container tank 1, and further improve the anti-scanning angle deviation, a rolling member 5 is rotatably installed at the end of the connecting rod 4d, the central axis of the rolling member 5 is parallel to the central axis of the container tank 1, and the generatrix of the rolling member 5 is on the same straight line as the generatrix of the container tank 1, and the diameter of the rolling member 5 is greater than the width of the connecting rod 4d, as long as the rolling member 5 is completely attached to the surface of the container tank 1, then the central axis of the container tank 1, the generatrix of the container tank 1 and the path of the laser emitted by the scanner 2 are on the same plane, otherwise the deviation will occur as shown in Figure 4 At this time, only a part of the rolling member 5 is in contact with the surface of the container tank 1; In order to facilitate the operator to find the deviation in time, a guide frame 6 is fixedly installed at the bottom of the connecting rod 4d, a wax strip 7 with matte powder is slidably installed in the guide frame 6, a positioning sheet 8 is fixedly installed at the bottom of the connecting rod 4d, a spring 9 is detachably installed on the positioning sheet 8, the end of the spring 9 is attached to the end of the wax strip 7, the wax strip 7 is attached to the surface of the rolling member 5, and is attached to the container tank 1, and the matte powder can also play a role in diffuse reflection, further improving the scanning effect, once the rolling member 5 is found to roll and attach the matte color strip on the container tank 1 to become narrow, it means that the deviation has occurred, and the operator can return to scan the deviated part again in time; Combined with the laser scanning pressure container shape deviation detection device, the application also provides a detection method for operating the laser scanning pressure container shape deviation detection device, and the use method comprises the following steps: S1: install the scanner 2 on the frame 3, make sure the axis of the container 1, the generatrix of the container 1 and the path of the laser emitted by the scanner 2 are in the same plane; S2: make the outer circumferential surface of the two rolling members 5 fit the outer circumferential surface of the container 1, rotate the knob 10 forward or backward according to the angle of the laser emitted by the scanner 2 and received by the scanner 2, adjust the distance between the scanner 2 and the container 1, make sure the laser emitted by the scanner 2 can be received; S3: start the scanner 2 and hold the handle 11, drive the scanner 2 around the outer circumferential surface of the container 1 under the premise that the rolling members 5 completely fit the outer surface of the container 1, then lift the device as a whole upward by a part, drive the scanner 2 in the opposite direction around the container 1 again, repeat until the cylindrical part of the container 1 is scanned out; S4: during this period, the rolling members 5 will contact the wax strip 7 to form a matte strip on the surface of the container 1, and the sudden thinning of the matte strip indicates that the pushing and scanning process has deviated, which can be moved in the opposite direction to scan again, avoiding missing scanning or distortion of scanning.

[0023] It is important to note that the constructions and arrangements of the application shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described in the application.

Claims

1. A laser scanning based pressure vessel shape deviation detection apparatus for detection of vertical vessel shell (1) comprising a hand held laser 3D scanner (2) characterized in that: Also include a frame (3), the frame (3) is close to the container tank (1) side with the scanner (2) detachable connection, the frame (3) on the symmetry installation isocenter component (4), two isocenter component (4) end are in contact with the surface of the container tank (1), two isocenter component (4) and scanner (2) form a triangle, the laser emitted by the scanner (2) is perpendicular to the midpoint of two isocenter component (4); Through two rotating parts end with the container tank (1) outer circumferential surface fit, while ensuring the distance between the scanner (2) and the container tank (1) is unchanged, but also can guarantee the container tank (1) axis, the container tank (1) generatrix and the path of the laser emitted by the scanner (2) are in the same plane.

2. The laser scanning based shape deviation detection device for pressure vessels according to claim 1, characterized in that: The isocenter component (4) includes the first shaft (4a) rotatably mounted on the frame (3), the swing bar (4b) rotatably mounted on the first shaft (4a), the second shaft (4c) rotatably mounted at the end of the swing bar (4b), the connecting rod (4d) rotatably mounted on the second shaft (4c), and the transmission member (4e) for controlling the angle between the swing bar (4b) and the connecting rod (4d) and the frame (3). When the angle between the two swing bars (4b) increases, the angle between the swing bar (4b) and the connecting rod decreases.

3. The laser scanning based shape deviation detection device for pressure vessels according to claim 2, characterized in that: The transmission member (4e) includes a first gear (4e1) fixedly mounted on the first shaft (4a), a second gear (4e2) rotatably mounted on the second shaft (4c), two third shafts (4e3) rotatably mounted on the frame (3), a driving wheel (4e4) rotatably mounted on the third shaft (4e3), a driven wheel (4e5) fixedly mounted on the connecting rod (4d), and a rack (4e6) slidably mounted on the swing bar (4b). The first gear (4e1) is engaged with the driving wheel (4e4), the second gear (4e2) is engaged with the driven wheel (4e5), and the first gear (4e1) and the second gear (4e2) are engaged with the rack (4e6). The first gear (4e1) is fixedly connected to the top surface of the swing bar (4b).

4. The laser scanning based shape deviation detection device for pressure vessels according to claim 3, characterized in that: The transmission member (4e) further includes a worm (4e7) rotatably mounted on the frame (3), and a worm wheel (4e8) engaged on one side of the worm (4e7). One of the third shafts (4e3) is fixedly connected to the worm wheel (4e8).

5. The laser scanning based shape deviation detection device for pressure vessels according to claim 2, characterized in that: The end of the connecting rod (4d) is rotatably mounted with a rolling member (5), the central axis of the rolling member (5) is parallel to the central axis of the container tank (1), and the generatrix of the rolling member (5) is in the same straight line with the generatrix of the container tank (1). The diameter of the rolling member (5) is greater than the width of the connecting rod (4d).

6. The laser scanning based shape deviation detection device for pressure vessels according to claim 2, characterized in that: The bottom of the connecting rod (4d) is fixedly mounted with a guide frame (6), the guide frame (6) is slidably mounted with a wax strip (7) with matte powder, and the bottom of the connecting rod (4d) is further fixedly mounted with a positioning sheet (8). The positioning sheet (8) is detachably mounted with a spring (9), and the end of the spring (9) is in contact with the end of the wax strip (7).

7. The laser scanning based shape deviation detection device for pressure vessels according to claim 3, characterized in that: The rack (4e6) can be replaced by an odd number of transmission gears engaged with each other, and the odd number of transmission gears are engaged with the first gear (4e1) and the second gear (4e2), respectively.

8. The laser scanning based shape deviation detection device for pressure vessels according to claim 4, characterized in that: The worm (4e7) end fixedly installs a knob (10), and the frame body (3) fixedly installs two handles (11).

9. A method for operating a laser scanning pressure vessel shape deviation detection apparatus according to any one of claims 1 to 8, characterized by: It comprises the following steps: S1: install the scanner (2) on the frame body (3), ensure that the axis in the container tank (1), the generatrix of the container tank (1) and the path of the laser emitted by the scanner (2) are in the same plane; S2: make the outer circumferential surface of the two rolling members (5) adhere to the outer circumferential surface of the container tank (1), rotate the knob (10) forward or backward according to the angle of the laser emitted and received by the scanner (2), adjust the distance between the scanner (2) and the container tank (1), and ensure that the laser emitted by the scanner (2) can be received; S3: start the scanner (2) and hold the handle (11), drive the scanner (2) to scan around the outer circumferential surface of the container tank (1) under the premise that the rolling member (5) completely adheres to the outer surface of the container tank (1), then lift the device upward by a part, and then drive the scanner (2) to scan around the container tank (1) in the opposite direction, repeat until the cylindrical part of the container tank (1) is scanned out; S4: During this period, the rolling member (5) will contact the wax strip (7) to form a matte strip on the surface of the container tank (1), and the sudden thinning of the matte strip indicates that the pushing and scanning process has deviated, which can be moved back in the opposite direction for scanning, avoiding missing scanning or distortion of scanning.

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