Mobile three-dimensional laser scanner calibration device and calibration method

Abstract

The present invention belongs to the technical field of three-dimensional laser scanner calibration, and is particularly a mobile three-dimensional laser scanner calibration device, including an instrument mounting platform and a heavy-duty bracket, wherein a detection instrument is mounted on the top of the instrument mounting platform through a mounting bracket. The mobile three-dimensional laser scanner calibration device and calibration method can quickly move the detection target assembly to a plurality of different coordinate positions in a small range around the calibration platform by adjusting structures such as a balance bar, an electric telescopic rod, a cross bar, and a bearing plate while keeping the position of the calibration platform unchanged. The position of the heavy-duty bracket can be moved over a large range by lifting universal wheels, so that multiple calibration devices can be conveniently set up to measure and calibrate the detection target assembly at different coordinate positions, greatly improving the diversity of measurement values ​​and calibration accuracy. The position adjustment of the detection target assembly is simple and fast, and covers a wide range, making the measurement values ​​more comprehensive, further improving the calibration accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional laser scanner calibration, and in particular to a mobile three-dimensional laser scanner calibration device and a calibration method. Background Art

[0002] The high-precision large-scene dynamic 3D laser scanner is based on the principle of laser ranging. Through the angle measurement function and spatial scanning control function, it can quickly obtain the three-dimensional spatial data of the surface of the measured object, and reconstruct the stereoscopic image model of the measured object through point cloud data modeling. This technology has many advantages in spatial measurement, such as non-contact, digitalization, intelligence, high efficiency and high precision. It is often used in many large-scale measurement scenarios such as construction and topographic surveying and mapping, mechanical manufacturing and processing, and device monitoring.

[0003] Since the accuracy and stability of the 3D laser scanner itself will affect the scanning results, it needs to be calibrated to ensure that its accuracy meets the measurement requirements. The existing 3D laser scanner calibration equipment currently has problems such as small calibration range and large investment, and cannot meet the large-space calibration and verification needs of 3D laser scanners. In addition, it is difficult to quickly locate and move the target during the calibration process, which not only increases the workload of calibration, but also becomes very troublesome when the target needs to be moved short distances and accurately positioned. These problems lead to the singleness of the calibration data, which in turn affects the accuracy of the calibration results. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a mobile three-dimensional laser scanner calibration device and a calibration method to solve the current problems.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A mobile 3D laser scanner calibration device comprises an instrument mounting platform and a heavy-duty bracket, wherein a detection instrument is mounted on the top of the instrument mounting platform through a mounting bracket, wherein the detection instrument comprises a laser tracker standard and a calibrated 3D laser scanner, wherein the heavy-duty bracket comprises a chassis, wherein a main frame is fixedly mounted at the top center of the chassis, and a triangularly symmetrically distributed balance board is fixedly mounted on the side of the chassis, wherein a liftable universal wheel is mounted at the bottom of each balance board, and the heavy-duty bracket can be conveniently moved through the universal wheel to meet different position requirements;

[0007] A balance bar is installed on the top of the main frame, and cross bars are installed on both sides of the balance bar. A carrying plate is slidably sleeved on the cross bar, and a connecting base is fixedly provided on the outer side of the carrying plate. A detection target assembly is installed on the connecting base. The detection target assembly includes a tracker target ball and a three-dimensional laser scanner target ball. The carrying plate can slide on the cross bar to change the position of the detection target assembly and measure the coordinates of the center of the target ball at different positions.

[0008] As a preferred technical solution of the present invention, a bottom groove is provided at the bottom of the balance board, an adjusting threaded rod is threadedly inserted at the top of the balance board, an adjusting knob is fixedly installed at the top of the adjusting threaded rod, a fastening sleeve is threadedly sleeved on the outside of the adjusting threaded rod and located at the top of the balance board, a connecting column is rotatably installed at the bottom end of the adjusting threaded rod, a sleeve column is fixedly installed on the side of the connecting column through a connecting block, a fixing column is fixedly installed on the top of the inner side of the bottom groove, the sleeve column is slidably sleeved on the outside of the fixing column, and the universal wheel is installed at the bottom of the sleeve column. By rotating the adjusting knob, the adjusting threaded rod is driven to rotate up and down to change the height of the universal wheel. When the universal wheel is lowered to contact the ground, the heavy-duty bracket can be moved. When the universal wheel is raised and enters the bottom groove, the heavy-duty bracket is conveniently fixed.

[0009] As a preferred technical solution of the present invention, a first fixed seat is threadedly installed on the connecting base, a rotating seat is rotatably installed on the first fixed seat, a central support column is fixedly installed at the center position of the rotating seat, a central connecting rod is plugged and installed at the port of the central support column, the three-dimensional laser scanner target ball is fixedly installed at the port of the central connecting rod, a plurality of eccentric support columns are fixedly installed at the eccentric position of the rotating seat and around the central support column, an eccentric connecting rod is plugged and installed at the port of the eccentric support column, a plurality of tracker target balls are provided, and a plurality of the tracker target balls are fixedly installed at the ports of the corresponding eccentric connecting rods, and at the same time, the spherical surfaces of the plurality of tracker target balls are in contact with the spherical surface of the three-dimensional laser scanner target ball, ensuring that the center of the sphere fitted by the center of the plurality of tracker target balls coincides with the center position of the three-dimensional laser scanner target ball, thereby improving the accuracy of the coordinate position.

[0010] As a preferred technical solution of the present invention, the connection between the central connecting rod and the central support column and the connection between the eccentric connecting rod and the eccentric support column are both fixed by magnetic attraction, and a limit pin is threadedly installed on the surface of the rotating seat. The limit pin passes through the rotating seat and is threadedly inserted into the interior of the first fixed seat. By rotating the rotating seat, the laser tracker standard can accurately measure the position coordinates of each tracker target ball without being blocked or interfered by the surrounding tracker target balls.

[0011] As a preferred technical solution of the present invention, an electric telescopic rod is installed on the main frame, and a fastening nut is fixed on the telescopic end of the electric telescopic rod. The lower end of the balance rod is threadedly inserted into the fastening nut. The setting of the fastening nut facilitates the disassembly of the balance rod. When there is no need to change the positions of the tracker target ball and the three-dimensional laser scanner target ball in a small range, the first fixing seat can also be directly threadedly inserted into the fastening nut, and the structure is simple.

[0012] As a preferred technical solution of the present invention, a through transverse groove is provided on the side of the balance bar, a plug rod is inserted in the transverse groove, a first fastening groove connected to the transverse groove is provided on the top of the balance bar, a ring-shaped abutment groove is provided on the outer side of the plug rod, a first fastening rod is threadedly inserted on the inner side of the first fastening groove, the top of the first fastening rod extends to the top of the first fastening groove and a first knob is fixedly installed, an abutment block is fixedly installed on the bottom of the first fastening rod, and evenly distributed protrusions are fixedly installed on the bottom of the abutment block, and the protrusions are consistent with the size of the abutment groove, and annular grooves are provided on the inner side of the transverse groove and on both sides of the first fastening groove, and limiting rings are fixedly sleeved on the outer side of the plug rod and on both sides of the abutment groove, and the limiting ring is rotatably connected to the inside of the annular groove. The above arrangement can enable the plug rod to rotate in the transverse groove as needed. After adjusting to a suitable angle, the first fastening rod is rotated downward and fixed by the abutment block.

[0013] As a preferred technical solution of the present invention, the surface of the cross bar is provided with symmetrically distributed sliding grooves, the side of the carrying plate is provided with an insertion groove, the cross bar is slidably inserted in the inner side of the insertion groove, the outer side of the carrying plate is provided with a second fastening groove connected to the insertion groove, the inner side of the second fastening groove is threaded with a second fastening rod, one end of the second fastening rod extends to the outside of the second fastening groove and is fixedly installed with a second knob, and the other end of the second fastening rod is fixedly installed with an abutment ball through a connecting rod, and the abutment ball is abutted and installed on the inner side of the sliding groove, the carrying plate is made to slide on the cross bar as needed, and then the position of the carrying plate is fixed by the abutment ball, and the lateral coordinate position of the detection target assembly 8 is changed.

[0014] A calibration method for a mobile three-dimensional laser scanner calibration device comprises the following steps:

[0015] S1. Install the laser tracker standard on the mounting frame, and install several tracker target balls on the ports of the eccentric connecting rod in sequence.

[0016] S2, rotating the rotating seat, adjusting the position of the tracker target ball, and using the laser tracker standard to measure the coordinates of all tracker target balls in sequence;

[0017] S3, remove the laser tracker standard and several tracker target balls, install the calibrated 3D laser scanner on the same position of the mounting frame, then install the 3D laser scanner target ball on the central support column, and measure the coordinates of the 3D laser scanner target ball through the calibrated 3D laser scanner;

[0018] S4. Calculate the coordinates of the center of the sphere of the target sphere of several trackers, and compare them with the coordinates of the center of the target sphere measured by the 3D laser scanner to obtain the error value of the calibrated 3D laser scanner.

[0019] S5. By adjusting the height of the universal wheel, the heavy-duty bracket can be switched between the mobile and fixed states, and the distance between the heavy-duty bracket and the instrument mounting table can be adjusted. Through the electric telescopic rod, rotating balance rod, sliding carrier plate and other operations, the coordinate position of the detection target assembly can be quickly adjusted, the change of error value under different coordinates can be measured, and multiple sets of data can be compared and analyzed to make the calibration of the 3D laser scanner more accurate.

[0020] Compared with the prior art, the present invention provides a mobile three-dimensional laser scanner calibration device and calibration method, which have the following beneficial effects:

[0021] 1. The mobile 3D laser scanner calibration device and calibration method can quickly move the detection target assembly to multiple different coordinate positions in a small range around the calibration platform by adjusting structures such as the balance rod, the electric telescopic rod, the cross bar and the carrying plate while keeping the position of the calibration platform unchanged. When calibrating a large space, the position of the heavy bracket can be moved over a large range by lifting the universal wheel, so that multiple calibration devices of the present application can be conveniently set up to measure and calibrate the detection target assemblies at different coordinate positions, which greatly improves the diversity of measurement values ​​and calibration accuracy. The position of the detection target assembly can be spatially adjusted in a simple and fast manner with a wide coverage, which can make the measurement values ​​more comprehensive and further improve the calibration accuracy.

[0022] 2. By starting and stopping the electric telescopic rod and rotating the first knob, the fastening sleeve, the fastening nut and the second knob, the detection target assembly after the coordinate adjustment can be quickly fixed in position, thereby improving the stability of the equipment and the accuracy of the coordinate measurement and calibration of the three-dimensional laser scanner.

[0023] 3. By plugging and unplugging the central connecting rod and the eccentric connecting rod, the 3D laser scanner target ball and the tracker target ball can be loaded and unloaded, and they can be measured separately. The magnetic fixation can improve the stability after plug-in installation, and avoid mutual obstruction between the tracker target ball and the 3D laser scanner target ball. Through the design of the limit pin, the obstructed tracker target ball can be rotated and measured without changing the center position of the circle fitted by the center of multiple tracker target balls. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure 2 It is an enlarged schematic diagram of the structure near the carrier plate of the present invention;

[0026] Figure 3 It is an enlarged schematic diagram of the structure near the connection base of the present invention;

[0027] Figure 4 This is a schematic diagram of the explosion structure near the abutment ball of the present invention;

[0028] Figure 5 It is an enlarged schematic diagram of the structure near the balance pole of the present invention;

[0029] Figure 6 This is a schematic diagram of the explosion structure near the insertion rod of the present invention;

[0030] Figure 7 It is an enlarged schematic diagram of the structure near the heavy-duty support of the present invention;

[0031] Figure 8 This is a schematic diagram of the structure near the adjusting threaded rod of the present invention;

[0032] Fig. 9 It is a schematic structural diagram of the second fixing base, the large calibration column and the small calibration column of the present invention;

[0033] Fig.10 It is a schematic diagram of the large calibration column in the present invention being plugged into the second fixing seat;

[0034] Fig.11 It is a schematic diagram of the small calibration column of the present invention being inserted into the second fixing seat.

[0035] In the figure: 1. Instrument mounting table; 2. Heavy-duty bracket; 21. Chassis; 22. Balance plate; 221. Adjustment threaded rod; 222. Adjustment knob; 223. Connecting column; 224. Connecting block; 225. Fixed column; 226. Socket column; 227. Universal wheel; 228. Fastening sleeve; 23. Fixed latch; 24. Support rod; 25. Bottom groove; 26. Main frame; 3. Mounting frame; 31. Testing instrument; 4. Electric telescopic rod; 5. Balance rod; 51. Horizontal groove; 52. Annular groove; 53. First fastening groove; 54. First fastening rod; 55. First knob; 56. Abutment block; 57. Fastening nut; 6. Horizontal rod; 61. Sliding Movable groove; 7, carrier plate; 71, plug-in groove; 72, second fastening groove; 73, second fastening rod; 74, connecting rod; 75, abutment ball; 76, second knob; 8, detection target assembly; 81, connecting base; 82, first fixed seat; 83, rotating seat; 84, central support column; 85, central connecting rod; 86, three-dimensional laser scanner target ball; 87, eccentric support column; 88, eccentric connecting rod; 89, tracker target ball; 810, limit pin; 9, plug rod; 91, abutment groove; 92, limit ring; 10, second fixed seat; 101, connecting groove; 102, large calibration column; 103, small calibration column; 104, magnetic block. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0037] For example, see Figure 1-8 As shown, the mobile 3D laser scanner calibration device includes an instrument mounting platform 1 and a heavy-duty bracket 2. A detection instrument 31 is installed on the top of the instrument mounting platform 1 through a mounting frame 3. The detection instrument 31 includes a laser tracker standard and a calibrated 3D laser scanner.

[0038] The heavy-duty bracket 2 includes a chassis 21, a main frame 26 is fixedly installed at the top center of the chassis 21, and a triangular symmetrically distributed balance board 22 is fixedly installed on the side of the chassis 21. A universal wheel 227 that can be raised and lowered is installed at the bottom of each balance board 22. The fixed end of the electric telescopic rod 4 is embedded and fixedly inserted at the top of the main frame 26, and a balance rod 5 is rotatably installed at the top of the telescopic end of the electric telescopic rod 4. Cross bars 6 are installed on both sides of the balance rod 5 through plug rods 9, and a load plate 7 is slidably sleeved on the outer side of the cross bar 6. A connecting base 81 is fixedly provided on the outer side of the carrier plate 7, and a detection target assembly 8 is installed on the connecting base 81. The detection target assembly 8 includes a tracker target ball 89 and a three-dimensional laser scanner target ball 86. In this embodiment, there are multiple tracker target balls 89 and they are distributed around the three-dimensional laser scanner target ball 86. The spherical surfaces of all tracker target balls 89 are connected to the spherical surfaces of the three-dimensional laser scanner target ball 86, ensuring that the center of the sphere fitted by the center of all tracker target balls 89 coincides with the center of the three-dimensional laser scanner target ball 86.

[0039] The center of the tracker target sphere 89 is measured by the laser tracker standard, and the center of the three-dimensional laser scanner target sphere 86 is measured by the calibrated three-dimensional laser scanner. The center of the circle fitted by the center of multiple tracker target spheres 89 is compared with the center coordinates of the three-dimensional laser scanner target sphere 86 to obtain the error value of the measured three-dimensional laser scanner.

[0040] In addition, rotating the balance bar 5 can drive the cross bar 6 to rotate, and at the same time drive the carrier plate 7 and the detection target assembly 8 to rotate, so that the horizontal coordinates of the detection target assembly 8 can be changed. The external power supply is turned on, and the electric telescopic rod 4 is started to extend and retract, driving the cross bar 6 and the carrier plate 7 to rise and fall, so that the Z-axis coordinates of the detection target assembly 8 can be changed. By pushing the carrier plate 7, the carrier plate 7 can be moved on the cross bar 6 to change the lateral coordinate position of the detection target assembly 8, so that the small-range coordinate positions of the tracker target ball 89 and the three-dimensional laser scanner target ball 86 can be quickly adjusted. When the position of the heavy-duty bracket 2 remains unchanged, the detection target assembly 8 can be quickly moved to multiple different coordinate positions around the heavy-duty bracket 2, and the detection target assembly 8 at different coordinate positions can be measured and calibrated, which greatly improves the diversity of the measured values ​​and the calibration accuracy, and realizes the spatial position adjustment of the detection target assembly 8. It is simple and fast, covers a wide range, and can make the measured values ​​more comprehensive, further improving the calibration accuracy.

[0041] refer to Figure 7-8As shown, a bottom groove 25 is provided at the bottom of the balancing board 22, an adjusting threaded rod 221 is threadedly inserted at the top of the balancing board 22, an adjusting knob 222 is fixedly installed at the top of the adjusting threaded rod 221, a fastening sleeve 228 is threadedly sleeved on the outside of the adjusting threaded rod 221 and located at the top of the balancing board 22, the fastening sleeve 228 is rotated to be close to the surface of the balancing board 22, and the adjusting threaded rod 221 is limited and fixed, a connecting column 223 is rotatably installed at the bottom end of the adjusting threaded rod 221, a sleeve column 226 is fixedly installed on the side of the connecting column 223 through a connecting block 224, a fixing column 225 is fixedly installed at the top inside the bottom groove 25, the sleeve column 226 is slidably sleeved on the outside of the fixing column 225, a universal wheel 227 is installed at the bottom of the sleeve column 226, and the balancing board 22 A fixing pin 23 that passes through the balance board 22 is inserted into the surface thread, and a support rod 24 is fixedly installed between the balance board 22 and the main frame 26. The fixing pin 23 can be inserted into the soil in a muddy ground environment to ensure the stability of the heavy-duty bracket 2; turning the adjusting knob 222 drives the adjusting threaded rod 221 to rotate and rise on the surface of the balance board 22, and drives the connecting block 224 to move through the connecting column 223, so that the sleeve column 226 rises outside the fixing column 225, and then drives the universal wheel 227 to rise and leave the ground, so that the bottom of the balance board 22 contacts the ground, and the position of the heavy-duty bracket 2 is fixed. On the contrary, the universal wheel 227 touches the ground and the balance board 22 is suspended in the air, which is convenient for the position movement of the heavy-duty bracket 2, making the distance adjustment during the calibration of the three-dimensional laser scanner more convenient.

[0042] When a three-dimensional laser scanner is measuring and calibrating within a large spatial range, the distance between the target ball to be measured and the instrument can be quickly adjusted through the universal wheel 227. At the same time, multiple calibration devices of the present application can be arranged as needed to measure and calibrate the detection target components at different coordinate positions, thereby greatly improving the diversity of measurement values ​​and calibration accuracy.

[0043] refer to Figure 1-3 As shown, a first fixed seat 82 is threadedly connected to the connecting base 81, a rotating seat 83 is rotatably installed on the outer side of the first fixed seat 82, a central support column 84 is fixedly installed at the center position of the rotating seat 83, a central connecting rod 85 is plugged and installed at the port of the central support column 84, a three-dimensional laser scanner target ball 86 is fixedly installed at the port of the central connecting rod 85, a plurality of eccentric support columns 87 are fixedly installed at the eccentric position of the rotating seat 83 and located around the central support column 84, an eccentric connecting rod 88 is plugged and installed at the port of the eccentric support column 87, and a plurality of tracker target balls 89 are fixedly installed at the corresponding ports of the eccentric connecting rod 88.

[0044] When measuring the three-dimensional laser scanner target sphere 86 and the tracker target sphere 89, in order to avoid occlusion between different types of spheres, when using the laser tracker standard to measure the center of the tracker target sphere 89, the three-dimensional laser scanner target sphere 86 is removed, and when using the calibrated three-dimensional laser scanner to measure the center of the three-dimensional laser scanner target sphere 86, the tracker target sphere 89 is removed. In this way, when the detection target assembly 8 is adjusted to multiple different positions, the coordinate measurement of the three-dimensional laser scanner target sphere 86 and the tracker target sphere 89 can be completed.

[0045] In this embodiment, the connection between the central connecting rod 85 and the central support column 84 and the connection between the eccentric connecting rod 88 and the eccentric support column 87 are both fixed by magnetic attraction. A limit pin 810 is threadedly installed on the surface of the rotating seat 83. The limit pin 810 passes through the rotating seat 83 and is threadedly inserted into the interior of the first fixed seat 82. There are multiple limit pins 810 and they are symmetrically distributed on the surface of the rotating seat 83. The three-dimensional laser scanner target ball 86 and the tracker target ball 89 can be loaded and unloaded by plugging and unplugging the central connecting rod 85 and the eccentric connecting rod 88. The magnetic fixation can improve the stability after plug-in installation and facilitate disassembly.

[0046] The design of the limit pin 810 allows the limit pin 810 to be threadedly inserted into the rotating seat 83 and the first fixed seat 82 during coordinate measurement to prevent the rotating seat 83 from rotating. When the tracker target ball 89 is blocked, the limit pin 810 can be removed, and the rotating seat 83 can be rotated on the first fixed seat 82 to drive the tracker target ball 89 to rotate for position adjustment. After adjustment, the limit pin 810 can be inserted again, thereby achieving fixed measurement of the blocked tracker target ball 89. Here, rotating the rotating seat 83 changes the coordinate positions of multiple tracker target balls 89, but does not change the center coordinates of the circles fitted by the multiple ball centers.

[0047] The calibration method using the above mobile 3D laser scanner calibration device comprises the following steps:

[0048] S1. Install the laser tracker standard on the mounting frame 3, and install several tracker target balls 89 in sequence at the ends of the eccentric connecting rod 88.

[0049] S2, rotating the rotating seat 83, adjusting the position of the tracker target ball 89, and using the laser tracker standard to measure the coordinates of all tracker target balls 89 in sequence;

[0050] S3, remove the laser tracker standard and several tracker target balls 89, install the calibrated 3D laser scanner on the same position of the mounting frame 3, install the 3D laser scanner target ball 86 on the central support column 84, and measure the coordinates of the 3D laser scanner target ball 86 by the calibrated 3D laser scanner;

[0051] S4, calculate the center coordinates of the spheres of the target spheres 89 of the tracker, and compare them with the center coordinates of the target sphere 86 measured by the 3D laser scanner to obtain the error value of the calibrated 3D laser scanner.

[0052] S5. By adjusting the height of the universal wheel 227, the heavy-duty bracket 2 is switched between the mobile and fixed states, and the distance between the heavy-duty bracket 2 and the instrument mounting table 1 is adjusted. By operating the electric telescopic rod 4, rotating the balance rod 5, and sliding the carrier plate 7, the coordinate position of the detection target assembly 8 is adjusted, and the change of the error value under different coordinates is measured. Multiple sets of data are compared and analyzed to improve the calibration accuracy of the three-dimensional laser scanner.

[0053] Embodiment 2, as Figure 9-11 As shown, a second fixing seat 10 is threadedly connected to the connecting base 81, a connecting groove 101 is provided on the top of the second fixing seat 10, a large calibration column 102 and a small calibration column 103 can be plugged and installed on the inner side of the connecting groove 101, a magnetic block 104 is fixedly installed on the bottom of the large calibration column 102 and the small calibration column 103, a three-dimensional laser scanner target ball 86 and a tracker target ball 89 are fixedly installed on the top of the large calibration column 102 and the small calibration column 103, respectively, the three-dimensional laser scanner target ball 86 and the tracker target ball 89 have the same ball center position after installation; remove the first fixing seat 82, install the second fixing seat 10 on the outer side of the connecting base 81, insert the large calibration column 102 and the small calibration column 103 into the connecting groove 101 respectively, measure with the three-dimensional laser scanner to be calibrated and the laser tracker standard respectively, calculate the ball center position for comparison, and obtain the error value of the three-dimensional laser scanner to be calibrated.

[0054] Embodiment three, as Figure 1 , 5As shown in Figure 6, a fastening nut 57 is threadedly sleeved on the outer side of the telescopic end of the electric telescopic rod 4 and located below the balance rod 5. By rotating the fastening nut 57, it is tightly attached to the bottom of the balance rod 5 so as to fix the balance rod 5. Otherwise, the balance rod 5 can be loosened. Rotating the balance rod 5 can drive the cross bar 6 to rotate as a whole, and the measured coordinate position is changed laterally. A transverse groove 51 running through the front and back is provided on the side of the balance rod 5. The insertion rod 9 is rotatably inserted into the inner side of the transverse groove 51. A first fastening groove 53 connected to the transverse groove 51 is provided on the top of the balance rod 5. Abutment grooves 91 distributed in an annular manner are provided on the outer side of the insertion rod 9. A first fastening rod 54 is threadedly inserted into the inner side of the first fastening groove 53. The top end of the first fastening rod 54 extends to the top of the first fastening groove 53 and is fixedly installed with a first Knob 55, the bottom end of the first fastening rod 54 is fixedly installed with an abutment block 56, and the bottom of the abutment block 56 is fixedly installed with evenly distributed protrusions, and the size of the protrusions matches the abutment groove 91. By rotating the insertion rod 9, the cross bar 6 and the supporting plate 7 can be driven to rotate, so that the detection target assembly 8 can be rotated around the cross bar 6, and its longitudinal coordinates can be adjusted, so that the adjustment range and measurement value of the detection target assembly 8 are more comprehensive, and the first fastening rod 54 is driven to rotate by rotating the first knob 55, so that the abutment block 56 is continuously approached to the abutment groove 91, and after the protrusion contacts and engages with the abutment groove 91, the abutment fixation of the insertion rod 9 is achieved, so that the position of the detection target assembly 8 after the coordinates are adjusted can be fixed, thereby improving the stability of the detection target assembly 8 during measurement.

[0055] In this embodiment, an annular groove 52 is opened on the inner side of the transverse groove 51 and on both sides of the first fastening groove 53, and a limiting ring 92 is fixedly sleeved on the outer side of the insertion rod 9 and on both sides of the abutment groove 91. The limiting ring 92 is rotatably connected to the inside of the annular groove 52. In this way, when the insertion rod 9 is rotated, the limiting ring 92 rotates synchronously in the annular groove 52, which can limit the position of the insertion rod 9 and improve the stability of the rotation of the insertion rod 9 and the adjustment of the position of the detection target assembly 8.

[0056] Embodiment 4, as Figure 1 , 2, 4 and 5, the cross bar 6 is fixedly installed at both ends of the insertion rod 9, the surface of the cross bar 6 is provided with symmetrically distributed sliding grooves 61, the side of the carrying plate 7 is provided with an insertion groove 71, the cross bar 6 is slidably inserted into the inner side of the insertion groove 71, the outer side of the carrying plate 7 is provided with a second fastening groove 72 connected to the insertion groove 71, the inner side of the second fastening groove 72 is threadedly inserted with a second fastening rod 73, one end of the second fastening rod 73 extends to the outside of the second fastening groove 72 and is fixedly installed with a second knob 76, and the other end of the second fastening rod 73 The end is fixedly installed with an abutment ball 75 through a connecting rod 74, and the abutment ball 75 is abutted against the inner side of the sliding groove 61; the second fastening rod 73 is driven to rotate by turning the second knob 76, so that the abutment ball 75 is clamped in the sliding groove 61, so that the supporting plate 7 can slide on the cross bar 6 along the trajectory of the sliding groove 61 to adjust the position, and after the position is adjusted, the second knob 76 is turned again, so that the abutment ball 75 contacts the inner wall of the sliding groove 61 and abuts against the sliding groove 61, thereby achieving the fixation of the position of the supporting plate 7.

[0057] By such a design, rotating the balance bar 5 drives the cross bar 6 to rotate, and at the same time drives the carrier plate 7 and the detection target assembly 8 to rotate, so that the horizontal coordinates of the detection target assembly 8 can be changed. The external power supply is turned on, and the electric telescopic rod 4 is started to extend and retract, driving the cross bar 6 and the carrier plate 7 to rise and fall, so that the Z-axis coordinates of the detection target assembly 8 can be changed. By pushing the carrier plate 7, the carrier plate 7 can be moved on the cross bar 6 to change the lateral coordinate position of the detection target assembly 8. By rotating the insertion rod 9, the cross bar 6 and the carrier plate 7 can be driven to rotate, so that the detection target assembly 8 can rotate around the cross bar 6 to adjust its longitudinal coordinates. In addition, by starting and stopping the electric telescopic rod 4 and rotating the first knob 55, the second knob 76 and the fastening nut 57, the detection target assembly 8 after the coordinates are adjusted can be quickly fixed in position, thereby improving the accuracy of coordinate measurement and calibration of the three-dimensional laser scanner.

Claims

1. A mobile three-dimensional laser scanner calibration device, comprising an instrument mounting platform (1) and a heavy-duty bracket (2), wherein a detection instrument (31) is mounted on the top of the instrument mounting platform (1) via a mounting frame (3), wherein the detection instrument (31) comprises a laser tracker standard and a three-dimensional laser scanner to be calibrated, and wherein: The heavy-duty bracket (2) comprises a chassis (21), a main frame (26) is fixedly mounted at the top center of the chassis (21), and balancing boards (22) symmetrically distributed in a triangular shape are fixedly mounted on the sides of the chassis (21), and a universal wheel (227) that can be raised and lowered is mounted at the bottom of each balancing board (22); A balancing pole (5) is installed on the top of the main frame (26), and cross bars (6) are installed on both sides of the balancing pole (5). A carrying plate (7) is slidably sleeved on the cross bar (6), and a connecting base (81) is fixedly provided on the outer side of the carrying plate (7). A detection target assembly (8) is installed on the connecting base (81), and the detection target assembly (8) includes a tracker target ball (89) and a three-dimensional laser scanner target ball (86); A plurality of tracker target balls (89) are provided, a first fixed seat (82) is threadedly plugged into the connection base (81), a rotating seat (83) is rotatably mounted on the first fixed seat (82), a central support column (84) is fixedly mounted at the center position of the rotating seat (83), a central connecting rod (85) is plugged into the port of the central support column (84), the three-dimensional laser scanner target ball (86) is fixedly mounted at the port of the central connecting rod (85), a plurality of eccentric support columns (87) are fixedly mounted at the eccentric position of the rotating seat (83) and located around the central support column (84), an eccentric connecting rod (88) is plugged into the port of the eccentric support column (87), a plurality of tracker target balls (89) are fixedly mounted at the ports of the corresponding eccentric connecting rods (88), and the spherical surfaces of the plurality of tracker target balls (89) are in contact with the spherical surface of the three-dimensional laser scanner target ball (86); An electric telescopic rod (4) is mounted on the main frame (26), a fastening nut (57) is fixed on the telescopic end of the electric telescopic rod (4), and the lower end of the balance rod (5) is threadedly inserted into the fastening nut (57); A through transverse groove (51) is provided on the side of the balance bar (5), an insertion rod (9) is inserted into the transverse groove (51), a first fastening groove (53) communicating with the transverse groove (51) is provided on the top of the balance bar (5), an abutment groove (91) distributed in an annular shape is provided on the outer side of the insertion rod (9), a first fastening rod (54) is threadedly inserted into the inner side of the first fastening groove (53), a top end of the first fastening rod (54) extends to the top of the first fastening groove (53) and a first knob (55) is fixedly mounted thereon, abutment blocks (56) are fixedly mounted at the bottom end of the first fastening rod (54), evenly distributed protrusions are fixedly mounted at the bottom of the abutment block (56), and the protrusions match the size of the abutment groove (91).

2. The mobile 3D laser scanner calibration device according to claim 1, characterized in that: The bottom of the balancing plate (22) is provided with a bottom groove (25); the top of the balancing plate (22) is threadedly plugged with an adjusting threaded rod (221); the top of the adjusting threaded rod (221) is fixedly mounted with an adjusting knob (222); the outside of the adjusting threaded rod (221) and located at the top of the balancing plate (22) is threadedly sleeved with a fastening sleeve (228); the bottom of the adjusting threaded rod (221) is rotatably mounted with a connecting column (223); the side of the connecting column (223) is secured by a hinge The connecting block (224) is fixedly mounted with a sleeve column (226); a fixing column (225) is fixedly mounted on the top of the inner side of the bottom groove (25); the sleeve column (226) is slidably sleeved on the outer side of the fixing column (225); the universal wheel (227) is mounted on the bottom of the sleeve column (226); a fixing pin (23) penetrating the balancing board (22) is threadedly inserted on the surface of the balancing board (22); and a support rod (24) is fixedly mounted between the balancing board (22) and the main frame (26).

3. The mobile 3D laser scanner calibration device according to claim 1, characterized in that: The connection between the central connecting rod (85) and the central supporting column (84) and the connection between the eccentric connecting rod (88) and the eccentric supporting column (87) are both fixed by magnetic attraction, and a limit pin (810) is threadedly installed on the surface of the rotating seat (83), and the limit pin (810) passes through the rotating seat (83) and is threadedly inserted into the interior of the first fixed seat (82).

4. The mobile 3D laser scanner calibration device according to claim 1, characterized in that: An annular groove (52) is provided on the inner side of the transverse groove (51) and on both sides of the first fastening groove (53), and a limiting ring (92) is fixedly sleeved on the outer side of the insertion rod (9) and on both sides of the abutment groove (91), and the limiting ring (92) is rotatably connected to the inside of the annular groove (52).

5. The mobile 3D laser scanner calibration device according to claim 1, characterized in that: The surface of the cross bar (6) is provided with symmetrically distributed sliding grooves (61), the side surface of the carrying plate (7) is provided with an insertion groove (71), the cross bar (6) is slidably inserted into the inner side of the insertion groove (71), the outer side of the carrying plate (7) is provided with a second fastening groove (72) connected with the insertion groove (71), the inner side of the second fastening groove (72) is threadedly inserted with a second fastening rod (73), one end of the second fastening rod (73) extends to the outside of the second fastening groove (72) and is fixedly mounted with a second knob (76), and the other end of the second fastening rod (73) is fixedly mounted with an abutment ball (75) through a connecting rod (74), and the abutment ball (75) is abutted against the inner side of the sliding groove (61).

6. A calibration method for a mobile 3D laser scanner calibration device as claimed in claim 1, characterized in that: The steps include: S1, installing a laser tracker standard on a mounting frame (3), and installing a plurality of tracker target balls (89) in sequence at the ends of an eccentric connecting rod (88); S2, rotating the rotating seat (83), adjusting the position of the tracker target ball (89), and using the laser tracker standard to measure the coordinates of all the tracker target balls (89) in sequence; S3, removing the laser tracker standard and several tracker target balls (89), installing the calibrated three-dimensional laser scanner at the same position of the mounting frame (3), installing the three-dimensional laser scanner target ball (86) on the central support column (84), and measuring the coordinates of the three-dimensional laser scanner target ball (86) by the calibrated three-dimensional laser scanner; S4, calculating the center coordinates of the spheres fitted to the center of the target spheres (89) of the tracking device, and comparing them with the center coordinates of the target sphere (86) measured by the three-dimensional laser scanner to obtain the error value of the calibrated three-dimensional laser scanner; S5. By adjusting the height of the universal wheel (227), the heavy-duty bracket (2) is switched between the mobile state and the fixed state, and the distance between the heavy-duty bracket (2) and the instrument mounting table (1) is adjusted. By operating the electric telescopic rod (4), rotating the balance rod (5), and sliding the carrier plate (7), the coordinate position of the detection target assembly (8) is adjusted, and the change of the error value under different coordinates is measured. Comparative analysis of multiple groups of data is performed to improve the calibration accuracy of the three-dimensional laser scanner.

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