CN111395124A - A three-dimensional laser detection device for road and airport pavement - Google Patents

Abstract

The invention relates to a three-dimensional laser detection device for roads and airport pavements, belonging to the field of detection instruments, comprising a laser collector, a vertical module, a horizontal module, a suspension bracket and a roller; the roller is located directly below the suspension bracket; the laser collector It is fixed on the suspension bracket; the suspension bracket is installed on the vertical module, and the vertical module is installed on the horizontal module. Among them, the combination of the horizontal module and the vertical module can arbitrarily adjust the height of the laser from the surface of the object to be measured, so as to determine the parameters such as laser brightness and effective acquisition width; by controlling the rotation speed of the roller through the PC, the accuracy at any acquisition speed can be carried out and repeatability test; the surface of the drum can be set to simulate road surface diseases, which can be used to test the recognition accuracy of specific diseases by identification software, and can effectively control the influence of natural light. To sum up, the present invention can better complete the calibration and debugging of the laser collector.

Description

A three-dimensional laser detection device for road and airport pavement

technical field

The invention relates to the field of detection instruments, in particular to a three-dimensional laser detection device for roads and airport pavements.

Background technique

With the vigorous promotion of 3D laser detection technology in engineering construction, the application of laser collectors has become more and more extensive, and the debugging work has become more and more normalized. Before the installation and use of the 3D laser collector, the sampling frequency, the distance between the laser and the surface of the detected object, the effective detection width, the uniformity of the lateral brightness of the line laser, the collection effect of typical diseases, and the repeatability verification must be calibrated. and debugging.

At present, there is no mature laser collector debugging platform in China. The existing technical solution usually installs the laser collector on the vehicle, and then tests it on the actual road. First, it is difficult to ensure that the wheel traces are completely consistent and the vehicle speed is stable during the test, that is, it is not convenient to control the calibration conditions because the stability of the vehicle speed and the repeatability of the driving trajectory cannot be guaranteed. Second, it is difficult to find a completely flat road for testing, and debugging on the acquisition vehicle, it is not convenient to control the distance between the laser acquisition instrument and the ground due to the bumpy vibration of the vehicle. Third, the on-site road test is cumbersome, and it takes a lot of manpower and material resources to close the traffic, and it is difficult to eliminate the influence of natural light.

SUMMARY OF THE INVENTION

Aiming at the deficiencies of the prior art, the present invention proposes a three-dimensional laser detection device for roads and airport pavements, which controls the drum through a PC to grasp the acquisition speed and realize repetitive testing. The distance between the laser and the surface of the detection object and the effective detection width are adjusted through the combination of the vertical module and the horizontal module, thereby realizing the uniformity of the horizontal brightness of the laser.

The technical scheme of the present invention is realized as follows:

A three-dimensional laser detection device for roads and airport pavements provided by the present invention includes a laser collector, a vertical module, a horizontal module, a suspension bracket and a roller; the roller is located directly below the suspension bracket; The laser collector is fixed on the suspension bracket; the suspension bracket is installed on the vertical module, and the vertical module is installed on the horizontal module.

The preferred technical solution of the present invention is that the horizontal module comprises a horizontal slide rail, a horizontal slide block and a horizontal slide seat; the horizontal slide block is provided with a first chute adapted to the horizontal slide rail, the The horizontal sliding block and the horizontal sliding seat are provided with corresponding bolt holes; the horizontal sliding rail is connected with the first sliding groove, and the horizontal sliding block is bolted with the horizontal sliding seat; the The vertical module is provided with a sliding seat connecting plate, and both the sliding seat connecting plate and the horizontal sliding seat are provided with corresponding bolt holes; the sliding seat connecting plate is bolted to the horizontal sliding seat.

A preferred technical solution of the present invention is that the vertical module further includes a vertical slide rail, a vertical slide block and a vertical slide seat; the vertical slide block is provided with a corresponding vertical slide rail. The second chute, the vertical sliding block and the vertical sliding seat are provided with corresponding bolt holes; the vertical sliding rail is connected with the second sliding groove, and the vertical sliding block and the The vertical sliding seat bolt connection;

The preferred technical solution of the present invention is that a three-dimensional laser detection device for roads and airport pavements further includes a base; two side plates of the base are provided with support plates, and the two side plates and the support The plates are provided with corresponding bolt holes; the center of the support plate is also embedded with a roller; the center of the roller is provided with a through hole; the roller includes a cylinder and a central axis; diorama. The central shaft is matched with the through hole; the side plate is bolted to the support plate, and the through hole is matched with the central shaft.

The preferred technical solution of the present invention is that a drum servo motor is fixed on the side plate; a distance encoder is also fixed on one of the support plates; the central axis is connected with the distance encoder, and the central axis passes through the conveyor belt connected with the drum servo motor;

The preferred technical solution of the present invention is that it also includes a PC with a control program, a horizontal control servo motor and a vertical control servo motor; the horizontal control servo motor is provided with a horizontal screw, and is fixed on the horizontal module one end; the horizontal module is also fixed with a horizontal screw slider, and the horizontal screw slider is provided with a thread adapted to the horizontal screw; the horizontal screw slider is connected to the The horizontal screw is threaded; the vertical control servo motor is provided with a vertical screw, which is fixed at one end of the vertical module; the vertical module is also fixed with a vertical screw slider, and the The vertical screw slider is provided with a thread that is adapted to the vertical screw; the vertical screw slider is threadedly connected with the vertical screw; the horizontal control servo motor, the Both the vertical control servo motor and the drum servo motor are connected with the PC through wires.

A preferred technical solution of the present invention is that the suspension bracket includes a fixed top plate, a rib plate, and a connecting plate; the fixed top plate and the connecting plate are vertically connected to each other; the rib plate and the fixed top plate are vertically connected to each other, and fixedly connected to the connecting plate.

The preferred technical solution of the present invention is that the fixed top plate is provided with a slot corresponding to the installation hole of the laser collector; the connection plate is provided with a hole corresponding to the fixed hole on the vertical sliding seat; the The fixed top plate is bolted to the laser collector, and the connection plate is bolted to the vertical sliding seat.

The preferred technical solution of the present invention is that it also includes a truss; the truss includes a plurality of transverse rods, longitudinal rods and truss connecting plates; the transverse rods are provided with holes corresponding to the mounting holes at the bottom of the horizontal module; The top of the base is also provided with a top plate, and the top plate is connected with the side plate; the truss is located on the base, and the truss connecting plate is fixed between the truss and the base; the horizontal The module is connected with the transverse rod by bolts.

Beneficial effects of the present invention:

First, the combination of the horizontal module and the vertical module can arbitrarily adjust the height of the laser from the surface of the object to be measured, thereby determining parameters such as laser brightness and effective collection width;

The second is to control the rotation speed of the roller through the PC, which can carry out the accuracy and repeatability test at any acquisition speed;

The third is that the surface of the drum can be set with simulated road diseases, which can be used to test the recognition accuracy of specific diseases by identification software, and can effectively control the influence of natural light.

To sum up, the three-dimensional laser detection device for roads and airport pavements provided by the present invention can better complete the calibration and debugging of laser collectors.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of the overall structure of a three-dimensional laser detection device for roads and airport pavements provided by the present invention;

2 is a front view of a three-dimensional laser detection device for roads and airport pavements provided by the present invention;

3 is an A-A sectional view of a three-dimensional laser detection device for roads and airport pavements provided by the present invention;

FIG. 4 is a partial enlarged view of the B direction of a three-dimensional laser detection device for roads and airport pavements provided by the present invention.

5 is a C-C cross-sectional view of a three-dimensional laser detection device for roads and airport pavements provided by the present invention;

FIG. 6 is a partial enlarged view of the D direction of a three-dimensional laser detection device for roads and airport pavements provided by the present invention.

FIG. 7 is a partial assembly view of a drum and a base of a three-dimensional laser detection device for roads and airport pavements provided by the present invention.

8 is a schematic diagram of a suspension bracket of a drum of a three-dimensional laser detection device for roads and airport pavements provided by the present invention.

The reference numerals in the figure are explained as follows:

1. Vertical module 11, sliding seat connecting plate 12, vertical sliding rail 13, vertical sliding block 14, vertical sliding seat 15, vertical control servo motor 151, vertical screw rod 152, vertical screw rod sliding Block 2, Horizontal Module 21, Horizontal Slide Rail 22, Horizontal Slider 23, Horizontal Slider 24, Horizontal Control Servo Motor 241, Horizontal Screw 242, Horizontal Screw Slider 3, Suspension Bracket 31, Fixed Top Plate 32, Ribs Plate 33, connecting plate 4, drum 41, cylinder 42, central axis 43, drum servo motor 5, laser collector 6, base 61, top plate 62, side plate 63, support plate 64, roller 65, distance encoder 7 , truss 71, transverse member 72, longitudinal member 73, truss connecting plate 8, drag chain

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," "fourth," etc. are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

As shown in FIG. 1 , a three-dimensional laser detection device for roads and airport pavements includes a laser collector 5, a vertical module 1, a horizontal module 2, a suspension bracket 3 and a roller 4; the roller 4 is located on the suspension bracket 3 The laser collector 5 is fixed on the suspension bracket 3; the suspension bracket 3 is installed on the vertical module 1, and the vertical module 1 is installed on the horizontal module 2. Specifically, the laser collector 5 is installed on the suspension bracket 3, and the suspension bracket 3 is installed on the vertical module 1. The suspension bracket 3 can be adjusted to rise and fall on the vertical module 1, and then be installed on the suspension bracket 3. The laser collector 5 on the top can realize the control of the distance from the surface of the detected object, and the vertical module 1 is installed on the horizontal module 2, and the vertical module 1 can slide horizontally on the horizontal module 2 as a whole. , so that the suspension bracket 3 can be slid horizontally, and the laser collector 5 can be adjusted horizontally. The drum 4 is located directly under the laser collector 5, and the effect on laser scanning and collection is relatively best. The drum 4 rotates, and the rotational speed can be controlled by a PC written in a control program, thereby realizing the accuracy and repeatability test at any acquisition speed.

As shown in Figures 2 and 4, the horizontal module 2 includes a horizontal slide rail 21, a horizontal slide block 22 and a horizontal slide seat 23; the horizontal slide block 22 is provided with a first chute adapted to the horizontal slide rail 21. The sliding block 22 and the horizontal sliding seat 23 are provided with corresponding bolt holes; the horizontal sliding rail 21 is connected with the first sliding groove, and the horizontal sliding block 22 is connected with the horizontal sliding seat 23 by bolts; the vertical module 1 is provided with sliding The seat connecting plate 11 , the sliding seat connecting plate 11 and the horizontal sliding seat 23 are provided with corresponding bolt holes; the sliding seat connecting plate 11 is connected with the horizontal sliding seat 23 by bolts. Specifically, the horizontal module 2 is divided into two upper and lower, and the two horizontal modules 2 are kept parallel to each other. The upper and lower ends of the vertical module 1 have sliding seat connecting plates 11 , the upper sliding seat connecting plate 11 is fixed on the upper horizontal module 2 , and the lower sliding seat connecting plate 11 is fixed on the lower horizontal module 2 . In addition, a drag chain 8 is also provided on the horizontal module 2, which can guide the wires to do directional movement and play a certain protective role.

As shown in FIGS. 2 , 4 and 6 , the vertical module 1 further includes a vertical slide rail 12 , a vertical slide block 13 and a vertical slide seat 14 ; The corresponding second chute, the vertical slider 13 and the vertical sliding seat 14 are provided with corresponding bolt holes; the vertical sliding rail 12 is connected with the second chute, the vertical slider 13 is connected to the vertical Sliding 14 bolt connection. Specifically, the length of the vertical module 1 should be greater than 1.5 m, and the distance between the two horizontal modules 2 is consistent with the length of the vertical module 1 . In addition, a drag chain 8 is also provided on the vertical module 1, which can guide the wires to do directional movement and play a certain protective role.

As shown in FIG. 7 , a three-dimensional laser detection device for roads and airport pavements further includes a base 6; the two side plates 62 of the base 6 are provided with support plates 63, and the two side plates 62 and the support plates 63 are provided with There are corresponding bolt holes; the center of the support plate 63 is also embedded with a roller 64; the center of the roller 64 is provided with a through hole; the roller 4 includes a cylinder 41 and a central axis 42; The shaft 42 is adapted to the through hole; the side plate 62 is bolted to the support plate 63, and the through hole is matched with the central shaft 42. Specifically, the diameter of the cylinder 41 is 50cm, and the central shaft 42 and the test line laser are kept in the same vertical plane.

As shown in FIG. 7 , the drum servo motor 43 is fixed on the side plate 62; one of the support plates 63 is also fixed with a distance encoder 65; the distance encoder 65 can transmit a rotation angle signal to the laser collector; The encoder 65 is connected; the central shaft 42 is connected with the drum servo motor 43 through the conveyor belt. In the prior art, the drum servo motor 43 drives the central shaft 42 to move by a belt drive, a pulley is installed on the drum servo motor 43, and another pulley is correspondingly installed on the central shaft 42, and the drum servo motor 43 starts and then The central shaft 42 is driven to rotate by means of a belt drive. The diameter of the cylinder body 41, the rotational speed of the drum servo motor and the transmission ratio should ensure that the maximum rotational linear speed of the outer diameter of the cylinder body 41 is not less than 100km/h.

As shown in FIGS. 2 and 4 , it also includes a PC with a control program, a horizontal control servo motor 24 and a vertical control servo motor 15 ; the horizontal control servo motor 24 is provided with a horizontal screw 241 and is fixed on the horizontal module 2 The horizontal module 2 is also fixed with a horizontal screw slider 242, and the horizontal screw slider 242 is provided with a thread that matches the horizontal screw 241; the horizontal screw slider 242 is threaded with the horizontal screw 241 Specifically, the horizontal screw slider 242 is fixedly connected with the horizontal sliding seat 23, the horizontal control servo motor 24 drives the horizontal screw 241, and the horizontal screw 241 drives the horizontal sliding seat 23 to move horizontally, thereby realizing the horizontal movement of the driving suspension bracket 3 The purpose, further, is to prompt the laser acquisition instrument 5 to perform horizontal scanning acquisition.

As shown in FIG. 2 and FIG. 6 , the vertical control servo motor 15 is provided with a vertical screw 151, which is fixed at one end of the vertical module 1; the vertical module 1 is also fixed with a vertical screw slider 152, and The vertical screw slider 152 is provided with threads matching the vertical screw 151; the vertical screw slider 152 is threadedly connected with the vertical screw 151; the vertical screw slider 152 is connected with the vertical screw The rod 151 is threadedly connected; specifically, the vertical screw slider 152 is fixedly connected with the vertical sliding seat 14, the vertical control servo motor 15 drives the vertical screw 151, and the vertical screw 151 drives the vertical sliding seat 14 vertically. move, so as to achieve the purpose of driving the suspension bracket 3 to move vertically, and further, to promote the purpose of detecting the distance of the surface of the object by the laser collector.

The horizontal control servo motor 24, the vertical control servo motor 15 and the drum servo motor 43 are all connected to the PC through wires. The PC is provided with a control program that can control the rotation of the servo motors of the vertical module 1, the horizontal module 2 and the drum 4; using the single-chip or PLC control technology in the prior art, the movement of the horizontal module 2 can be independently controlled. , The movement of the vertical module 1 and the movement of the roller 4, the use of the horizontal module 2 should be able to maintain the synchronous movement of the two horizontal modules 2; the wires and the PC are not displayed in the legend for the time being, and the vertical The movement of the module 1 should be able to accurately position according to the preset height; the movement of the drum 4 should be able to ensure that the linear speed of the outermost circle of the drum 4 is maintained at a constant speed within the range of 0-100km/h.

As shown in FIG. 8 , the suspension bracket includes a fixed top plate 31 , a rib plate 32 and a connecting plate 33 ; the fixed top plate 31 and the connecting plate 33 are vertically connected to each other; Specifically, the fixed top plate 31 is in the shape of a rectangle, the short side of the rectangle is vertically butted with the connecting plate 33, and the connection between the fixed top plate 31 and the connecting plate 33 is welding connection; There are threaded holes corresponding to the fixed top plate 31 on the side surface, and the fixed top plate 31 and the rib plate 32 are connected by screws to play a supporting role.

As shown in FIG. 8 , the fixed top plate 31 is provided with a slot corresponding to the installation hole of the laser collector 5; the connecting plate 33 is provided with a hole corresponding to the fixed hole on the vertical sliding seat 14; the fixed top plate 31 and the laser collector 5. Bolt connection, the connecting plate 33 is bolted to the vertical sliding seat 14.

As shown in FIGS. 1, 3 and 7, a three-dimensional laser inspection device for roads and airport pavements further includes a truss 7; the truss includes several transverse rods 71, longitudinal rods 72 and truss connecting plates 73; There is a hole corresponding to the mounting hole at the bottom of the horizontal module 2; the top of the base 6 is also provided with a top plate 61, which is connected to the side plate 62; the truss 7 is located on the base 6, and the truss connecting plate 73 is fixed on the truss 7 and the base. 6; the horizontal module 2 and the transverse rod 71 are bolted. Among them, the height of the truss 7 is greater than 1.5m, and it is vertically installed on the top of the base 6 .

Beneficial effects of the present invention:

First, the combination of the horizontal module and the vertical module can arbitrarily adjust the height of the laser from the surface of the object to be measured, thereby determining parameters such as laser brightness and effective collection width;

The second is to control the rotation speed of the roller through the PC, which can carry out the accuracy and repeatability test at any acquisition speed;

Third, the surface of the drum can be set with simulated road diseases, which can be used to test the recognition accuracy of specific diseases by identification software, and can effectively control the influence of natural light.

To sum up, the three-dimensional laser detection device for roads and airport pavements provided by the present invention can better complete the calibration and debugging of laser collectors.

Obviously, the above-mentioned embodiments are only examples for clear description, and are not intended to limit the implementation manner. For those of ordinary skill in the art, changes or modifications in other different forms can also be made on the basis of the above description. There is no need and cannot be exhaustive of all implementations here. Any obvious modifications, equivalent replacements, improvements, etc. derived from this should be included within the protection scope of the present invention.

Claims (9)

1. The utility model provides a road and three-dimensional laser detection device of airport pavement, includes laser acquisition appearance (5), its characterized in that:

the device also comprises a vertical module (1), a horizontal module (2), a suspension bracket (3) and a roller (4);

the roller (4) is positioned right below the suspension bracket (3);

the laser acquisition instrument (5) is fixed on the suspension bracket (3); the suspension support (3) is arranged on the vertical module (1), and the vertical module (1) is arranged on the horizontal module (2).

2. The three-dimensional laser detection device for the road and airport pavement according to claim 1, wherein:

the horizontal module (2) comprises a horizontal sliding rail (21), a horizontal sliding block (22) and a horizontal sliding seat (23); the horizontal sliding block (22) is provided with a first sliding groove matched with the horizontal sliding rail (21), and the horizontal sliding block (22) and the horizontal sliding seat (23) are provided with corresponding bolt holes;

the horizontal sliding rail (21) is connected with the first sliding groove, and the horizontal sliding block (22) is in bolted connection with the horizontal sliding seat (23);

the vertical module (1) is provided with a sliding seat connecting plate (11), and corresponding bolt holes are formed in the sliding seat connecting plate (11) and the horizontal sliding seat (23); the sliding seat connecting plate (11) is connected with the horizontal sliding seat (23) through bolts.

3. The three-dimensional laser detection device for the road and airport pavement according to claim 2, wherein:

the vertical module (1) further comprises a vertical slide rail (12), a vertical sliding block (13) and a vertical sliding seat (14); the vertical sliding block (13) is provided with a second sliding groove matched with the vertical sliding rail (12), and the vertical sliding block (13) and the vertical sliding seat (14) are provided with corresponding bolt holes;

the vertical sliding rail (12) is connected with the second sliding groove, and the vertical sliding block (13) is connected with the vertical sliding seat (14) through bolts.

4. The three-dimensional laser detection device for the road and airport pavement according to claim 1 or 3, wherein:

also comprises a base (6);

supporting plates (63) are arranged on the two side plates (62) of the base (6), and the two side plates (62) and the supporting plates (63) are provided with corresponding bolt holes; the center of the supporting plate (63) is embedded with a roller (64); a through hole is formed in the center of the roller (64);

the drum (4) comprises a drum body (41) and a central shaft (42);

the surface of the cylinder body (41) is provided with a three-dimensional model of typical pavement diseases;

the central shaft (42) is matched with the through hole;

the side plate (62) is connected with the support plate (63) through bolts, and the through hole is matched with the central shaft (42).

5. The three-dimensional laser detection device for the road and airport pavement according to claim 4, wherein:

a roller servo motor (43) is fixed on the side plate (62);

one of the support plates (63) is also fixed with a distance encoder (65);

the central shaft (42) is connected with the distance encoder (65), and the central shaft (42) is connected with the roller servo motor (43) through a conveyor belt.

6. The three-dimensional laser detection device for the road and airport pavement according to claim 5, wherein:

the device also comprises a PC provided with a control program, a horizontal control servo motor (24) and a vertical control servo motor (15);

the horizontal control servo motor (24) is provided with a horizontal screw rod (241) and is fixed at one end of the horizontal module (2);

a horizontal screw rod sliding block (242) is further fixed on the horizontal module (2), and threads matched with the horizontal screw rod (241) are arranged in the horizontal screw rod sliding block (242);

the horizontal screw rod sliding block (242) is in threaded connection with the horizontal screw rod (241);

the vertical control servo motor (15) is provided with a vertical screw rod (151) and is fixed at one end of the vertical module (1);

a vertical screw rod sliding block (152) is further fixed on the vertical module (1), and threads matched with the vertical screw rod (151) are arranged in the vertical screw rod sliding block (52);

the vertical screw rod sliding block (152) is in threaded connection with the vertical screw rod (151);

the horizontal control servo motor (24), the vertical control servo motor (15) and the roller servo motor (43) are all connected with the PC through wires.

7. The three-dimensional laser detection device for the road and airport pavement according to claim 1, wherein:

the suspension bracket comprises a fixed top plate (31), a rib plate (32) and a connecting plate (33);

the fixed top plate (31) and the connecting plate (33) are mutually and vertically connected; the rib plate (32) and the fixed top plate (31) are mutually and vertically connected and are fixedly connected with the connecting plate (33).

8. The three-dimensional laser detection device for the road and airport pavement according to claim 7, wherein:

the fixed top plate (31) is provided with a groove corresponding to the mounting hole of the laser acquisition instrument (5);

the connecting plate (33) is provided with holes corresponding to the fixing holes on the vertical sliding seat (14);

the fixed top plate (31) is connected with the laser acquisition instrument (5) through bolts, and the connecting plate (33) is connected with the vertical sliding seat (14) through bolts.

9. The three-dimensional laser detection device for the road and airport pavement according to claim 4, wherein:

also comprises a truss (7);

the truss comprises a plurality of transverse rods (71), a plurality of longitudinal rods (72) and truss connection plates (73);

the transverse rod piece (71) is provided with a hole corresponding to the mounting hole at the bottom of the horizontal module (2); the top of the base (6) is also provided with a top plate (61), and the top plate is connected with the side plate (62);

the truss (7) is positioned on the base (6), and the truss connecting plate (73) is fixed between the truss (7) and the base (6);

the horizontal module (2) is connected with the transverse rod piece (71) through a bolt.

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