A three-dimensional positioning net rack mounting jig and a method of using the same

Abstract

The present application relates to a kind of three-dimensional positioning net frame mounting jig and its using method, belong to large steel net frame structure construction equipment field, the present application includes pedestal, vertical pole, chord ball support table, the upper end surface of chord ball support table is equipped with the circumferentially uniform sliding slot;The sliding slot is equipped with chord ball adjusting and positioning assembly;Chord ball adjusting and positioning assembly is used to adjust the horizontal displacement of lower chord ball;The present application is also equipped with infrared positioner, angle encoder, laser range finder, and matched signal fusion module, realize the three-dimensional position detection of lower chord ball, closed loop adjustment;The present application can realize the elevation consistency of different diameter lower chord ball, combined with laser coordinate positioning technology realizes node ±2mm level installation precision, realizes the accurate positioning of lower chord ball.Accurate three-dimensional positioning of lower chord ball indirectly realizes the automatic positioning of web pole: after the determination of the center coordinates of adjacent lower chord ball, the length and angle of web pole are automatically solved by geometric relation, guide artificial or mechanical arm installation, without additional positioning device, the installation angle deviation of web pole is ≤1 °.

Description

Technical Field

[0001] This invention belongs to the field of construction equipment for large steel space frame structures. Specifically, it relates to a three-dimensional positioning space frame installation jig and its usage method. Background Technology

[0002] In the construction of large steel space frames (such as stadiums and exhibition centers), traditional construction methods use steel pipes or brick piers as support frames for the lower chord spheres. However, this method has the following problems: First, the elevation control accuracy is low. Due to the large difference in the diameter of the lower chord spheres (80-400mm), steel pipes or brick piers of fixed height cannot guarantee a consistent elevation of the sphere center, with actual elevation deviations reaching ±20mm. Second, the support stability is poor. There is no reliable connection between the steel pipes or brick piers and the ground, which easily leads to displacement during construction, causing the lower chord spheres to shift, with the maximum shift exceeding 15mm. Third, there is serious material waste. Traditional support frames are disposable structures, resulting in high material consumption, high costs, and high scrap rates. Fourth, the positioning efficiency is low and the deviation is large. The installation of the upper chord spheres and web members relies on manual string line measurement, with single-node positioning taking more than 30 minutes and angle deviations often exceeding 3°. Summary of the Invention

[0003] To overcome the problems existing in the background technology, this invention provides a three-dimensional positioning grid installation jig and its usage method, which can achieve consistent elevation of lower chord spheres of different diameters. Combined with laser coordinate positioning technology, it achieves installation accuracy of ±2mm at the nodes, enabling precise positioning of the lower chord spheres. Furthermore, through the precise three-dimensional positioning of the lower chord spheres, it indirectly achieves automated positioning of the web members: after the center coordinates of adjacent lower chord spheres are determined, the length and angle of the web members are automatically calculated based on geometric relationships, guiding manual or robotic arm installation without the need for additional positioning devices. The installation angle deviation of the web members is ≤1°.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0005] The three-dimensional positioning grid installation frame includes a base, uprights, a chord ball support platform, an infrared positioning instrument, an angle encoder, and a laser rangefinder.

[0006] The base is a plate-shaped structure with bolt holes, and is fixed to the foundation with bolts.

[0007] The upright pole includes a hydraulic sleeve and an adjusting upright pole. The lower end of the hydraulic sleeve is connected to the base, and the upper end is sleeved with the adjusting upright pole. The adjusting upright pole moves axially up and down under the action of hydraulic pressure inside the hydraulic sleeve to achieve the height adjustment of the upright pole.

[0008] A ball bearing support platform is horizontally fixed to the top of an adjusting rod. The upper surface of the ball bearing support platform has circumferentially distributed sliding grooves. A ball bearing adjustment and positioning assembly is installed within each groove. The ball bearing adjustment and positioning assembly includes a precision lead screw, a bidirectional servo motor, and a ball bearing limiter. The precision lead screw is positioned within the groove. The bidirectional servo motor is connected to the precision lead screw via a transmission. The ball bearing limiter is fixed to the lead screw nut of the precision lead screw.

[0009] Infrared positioning device; the infrared positioning device is set at the four corners of the string ball support platform, emits cross infrared beams to form a planar coordinate system, covering the sliding range of the slide, and detects the displacement coordinates of the string ball limiter in real time;

[0010] Angle encoder; the angle encoder is installed at the bottom of the pole to monitor the verticality of the pole.

[0011] A laser rangefinder; the laser rangefinder is horizontally installed on the edge of the chord ball support platform, and is respectively aligned with the center point of the lower chord ball of the adjacent pre-positioned frame support; the laser rangefinder is used to measure the straight distance between adjacent frame nodes, and combined with the tilt angle data of the angle encoder, calculates the three-dimensional coordinates of the nodes using the cosine theorem.

[0012] Furthermore, the three-dimensional positioning grid mounting frame also includes a signal fusion module; the signal fusion module is an analog circuit module, including a signal comparator and logic gate circuits; the angle encoder and laser rangefinder are connected to the signal comparator via the CAN bus protocol, the signal comparator receives the distance data from the laser rangefinder and the tilt angle data from the angle encoder, and transmits them to the logic gate circuit via the CAN bus protocol; the logic gate circuit generates a pulse signal based on the comparison result between the received data and the original design data, and drives the hydraulic controller of the hydraulic sleeve through the digital-to-analog converter, triggering the fine-tuning action of the hydraulic sleeve.

[0013] Furthermore, the signal comparator sets a distance threshold (L0±2mm) and an inclination threshold (±0.1°) through an adjustable resistor; if the measured value exceeds the limit, the signal comparator outputs a high-level signal to the logic gate circuit, which generates a pulse signal and drives the fine-tuning action of the hydraulic sleeve through the solenoid valve of the hydraulic controller, forming a closed-loop control.

[0014] Furthermore, the three-dimensional positioning grid frame mounting fixture also includes a camera, which is aimed at the ball bearing support platform to capture images. The surface of the ball bearing support platform is engraved with grid marks and equipped with an optical scale. The camera is connected to a signal comparator through an image processing module. The coordinates (x, y) detected by the infrared positioning instrument are compared with the grid marks on the optical scale to determine the offset between the reflected mark points and the grid. If the deviation exceeds ±1mm, the signal comparator outputs a correction command to the controller of the bidirectional servo motor to drive the precision lead screw to adjust the position of the ball bearing limiter.

[0015] Furthermore, the aforementioned sliding grooves are provided in three or more sections, evenly distributed around the center circumference of the chord ball support platform; the chord ball limiter is a V-shaped groove plate structure with an arc-shaped concave surface in the middle, which fits against the outer wall of the lower chord ball and is radially clamped by a precision lead screw.

[0016] Furthermore, the ball limiter is equipped with a self-locking device; the self-locking device is an electromagnetic lock, and the self-locking device is integrated into the bottom of the V-groove.

[0017] The method for positioning the lower chord ball using the aforementioned mounting bracket includes at least one of the following:

[0018] (1) Adjusting the horizontal direction of the lower string ball

[0019] A bidirectional servo motor drives a precision lead screw to rotate, which in turn moves the ball limiter; an infrared positioning instrument detects the coordinates (x, y) of the ball limiter in real time through reflective markers.

[0020] The coordinates (x, y) detected by the infrared positioning device are aligned with the grid marks of the optical scale by the offset of the reflected mark points and the grid captured by the camera. When the deviation exceeds ±1mm, the bidirectional servo motor is activated to correct the position of the chord ball limiter.

[0021] (2) Adjustment of verticality of the pole

[0022] The laser rangefinder and angle encoder are connected to the signal fusion module via the CAN bus protocol to transmit distance and tilt angle data in real time. The angle encoder determines the verticality of the upright based on the distance data between the center points of the lower chord balls of the adjacent support frames that have been positioned by the laser rangefinder. The determination method is as follows: based on the deviation between the distance L between the adjacent support frames measured by the laser rangefinder and the theoretical design value L0, combined with the tilt angle α of the angle encoder, if |L-L0|>threshold or |α|>0.1°, the signal comparator outputs an over-limit signal to the logic gate circuit. The logic gate circuit generates a pulse signal to trigger the hydraulic controller of the hydraulic sleeve, driving the adjustment upright to correct the verticality.

[0023] (3) Adjustment of the lifting height of the pole

[0024] The method for calculating the height adjustment amount is as follows:

[0025] ΔH=H0+D / 2-(R1+R2)

[0026] In the formula, ΔH is the height adjustment amount; H0 is the design elevation; D is the diameter of the lower chord ball; R1 is the compression amount of the rubber pad; and R2 is the compensation value for the expansion and contraction of the pole caused by the ambient temperature.

[0027] An angle encoder monitors changes in the height of the upright. If the upright tilts, the angle encoder feeds back the tilt angle α to the signal fusion module. Combined with the distance L between adjacent jigs measured by the laser rangefinder, the height change is calculated using the formula ΔH = L·sinα, achieving closed-loop dynamic adjustment. The hydraulic sleeve dynamically adjusts based on the difference between ΔH and the real-time height feedback from the encoder, with an accuracy of ±1mm.

[0028] Using the above-described method of positioning the lower chord ball with the mounting frame, the three-dimensional coordinates (x, y, z) of the current node are calculated by using the known coordinates (x1, y1, z1) of the adjacent nodes and the measured distance L, ensuring that the node position meets the design requirements.

[0029] Using the above-described method for positioning the web member using the mounting frame, based on the obtained coordinates (x1, y1, z1) and (x2, y2, z2) of the centers of the adjacent lower chord spheres, the length L of the web member is determined by the formula... The calculations provide guidance for the installation of the web members.

[0030] The beneficial effects of this invention are:

[0031] This invention provides a string ball adjustment and positioning component on a string ball support platform. The string ball positioning component, in conjunction with an infrared positioning device, detects the displacement coordinates of the string ball limiter in real time, thereby accurately positioning the lower string ball.

[0032] The structural design of this invention, combined with the use and position setting of a laser rangefinder, angle encoder, and infrared positioning device, enables precise three-dimensional positioning and adjustment of the lower chord ball. It can achieve elevation adjustment and precise node positioning for lower chord balls of different diameters (Φ80-400mm), with a center elevation error of ≤±1.5mm. It can also achieve a positioning accuracy of ±2mm for the center point of the lower chord ball supported by adjacent positioning frames.

[0033] This invention indirectly achieves automated positioning of the web member through precise three-dimensional positioning of the lower chord ball: after the center coordinates of adjacent lower chord balls are determined, the length and angle of the web member are automatically calculated by geometric relationships, guiding manual or robotic arm installation without the need for additional positioning devices, and the web member installation angle deviation is ≤1°.

[0034] The frame of this invention has a reuse rate of over 95% and improves construction efficiency by more than 50%, making it suitable for efficient construction of large-span steel space frame projects. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the three-dimensional positioning grid frame installation jig of the present invention;

[0036] Figure 2 This is the invention Figure 1 Sectional view from direction 1-1;

[0037] Figure 3 This is a top view of the present invention;

[0038] Figure 4 yes Figure 3 Sectional view of side 2-2;

[0039] Figure 5 This is a data transmission control logic diagram of the present invention (solid lines represent data flow; dashed lines represent feedback signals);

[0040] In the figure, there are base 101, bolt hole 102, upright 104, hydraulic sleeve 106, adjusting upright 105, chord ball support platform 108, slide groove 109, precision lead screw 112, bidirectional servo motor 111, chord ball limiter 110, infrared positioning device 205, and hoisting ear plate 301. Detailed Implementation

[0041] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are all within the scope of protection of this invention.

[0042] Example 1

[0043] A three-dimensional positioning grid frame installation jig includes a base 101, uprights 104, a chord ball support platform 108, an infrared locator 205, a laser rangefinder, and an angle encoder. The base 101 is a square plate structure with bolt holes 102 around its perimeter, and is fixed to the foundation with anchor bolts to ensure the structural stability of the entire installation jig.

[0044] The mounting frame of the present invention can adjust the lower ball in three dimensions to achieve accurate three-dimensional positioning of the lower ball. For ease of explanation, in the following content, the horizontal position adjustment of the lower ball is represented by the X-axis (or X direction) and Y-axis (or Y direction) adjustment, and the vertical position adjustment of the lower ball is represented by the Z-axis (or Z direction) adjustment.

[0045] The upright 104 includes a hydraulic sleeve 106 and an adjusting upright 105. The lower end of the hydraulic sleeve 106 is connected to the base 101, and the upper end is sleeved with the adjusting upright 105. The ball bearing support 108 is horizontally fixed to the top of the adjusting upright 105. Under the hydraulic pressure provided in the hydraulic sleeve 106, the adjusting upright 105 can rise or fall, thereby adjusting the total height of the upright 104, and thus adjusting the height of the ball bearing support 108, thereby adjusting the Z-axis position of the lower chord ball on the ball bearing support 108.

[0046] The ball support platform 108 is a square plate structure, with its bottom center fixedly connected to the top of the adjusting rod 105. Four sliding grooves 109 are evenly distributed along the circumference of the center of the ball support platform 108 on its upper surface. Each of the four sliding grooves 109 contains a ball adjustment and positioning component, which adjusts the position of the lower ball in the horizontal direction (X and Y directions) under the action of these components.

[0047] The ball adjustment and positioning assembly includes a precision lead screw 112, a bidirectional servo motor 111, and a ball limiter 110. The precision lead screw 112 is housed within a slide groove; the bidirectional servo motor 111 is connected to the precision lead screw 112 via a transmission connection, and the ball limiter 110 is rigidly connected to the lead screw nut of the precision lead screw 112 via a dovetail groove structure. When the bidirectional servo motor 111 drives the precision lead screw 112 to rotate, the lead screw nut moves linearly along the slide groove 109, causing the ball limiter 110 to move synchronously, thus achieving radial clamping or loosening of the lower ball. The forward and reverse rotation of the bidirectional servo motor 111 causes the precision lead screw 112 to move away from or closer to the center of the ball support platform 108, thereby causing the ball limiter 110 to move away from or closer to the center of the ball support platform 108, achieving position adjustment of the ball supported on the ball support platform 108 in the X and Y axes. Furthermore, the structure of the four slide grooves 109 evenly distributed circumferentially along the center of the ball support platform 108 allows for position fixing of balls of different diameters.

[0048] The ball limiter 110 has a V-shaped groove plate structure with an arc-shaped concave surface in the middle, which fits against the outer wall of the lower ball. With the combined action of the four ball limiters 110, the lower ball can be clamped and fixed in position under the clamping of the four ball limiters 110.

[0049] As a preferred embodiment, the ball limiter 110 is equipped with a self-locking device, which is an electromagnetic lock integrated into the bottom of the V-groove of the ball limiter 110. When the lower ball position is adjusted, the electromagnetic lock locks the lower ball.

[0050] As a preferred embodiment, the three-dimensional positioning grid frame installation jig of the present invention also includes a quick disassembly and assembly unit, which includes a lifting ear plate 301: the lifting ear plate 301 is welded to the four corners of the base 101 and connected to the main structure through pins, supporting the overall lifting and transfer, with a reuse rate of over 95% and an improvement in construction efficiency of over 50%.

[0051] The above-described structure of this invention enables position adjustment of the lower spool. This invention also utilizes monitoring instruments and a signal fusion module to monitor, adjust, and calibrate the position of the lower spool, thereby achieving precise installation and positioning. The monitoring instruments used in this invention include an infrared locator 205, an angle encoder, a laser rangefinder, an optical ruler, and a camera. The signal fusion module includes a signal comparator, a CAN bus protocol transmission logic gate circuit, and the signal comparator sets a threshold value through an adjustable resistor. The control logic diagram is shown in the attached figure. Figure 5 .

[0052] The locations and functions of the instruments are as follows:

[0053] Four infrared positioning devices 205 are set up and arranged at the four corners of the ball support platform 108. They emit cross infrared beams to form a planar coordinate system, covering the movement range of the slide 10, and detect the displacement coordinates of the ball limiter 110 in real time.

[0054] An angle encoder, installed at the bottom of pole 104, monitors the tilt angle α of pole 104 and compensates for expansion and contraction errors caused by temperature. It has a resolution of 0.01° and integrates a temperature compensation module.

[0055] A laser rangefinder is horizontally installed on the edge of the chord ball support platform 108. It is aligned with the center point of the lower chord ball of the adjacent support frame and measures the straight distance between adjacent frame nodes. Combined with the tilt data of the angle encoder, the three-dimensional coordinates of the nodes are calculated by the cosine theorem.

[0056] An optical scale and camera are provided. The surface of the ball support platform 108 is engraved with grid marks and equipped with an optical scale. The camera is connected to a signal comparator through an image processing module. The coordinates x, y detected by the infrared positioning instrument 205 are compared with the grid marks on the optical scale to determine the offset between the reflected mark points and the grid. If the deviation exceeds ±1mm, the signal comparator outputs a correction command to the controller of the bidirectional servo motor 111, which drives the precision lead screw 112 to adjust the position of the ball limiter 110, thereby adjusting the position of the lower ball.

[0057] Example 2

[0058] A method for adjusting the installation of a large steel space frame is disclosed. This embodiment primarily focuses on positioning the lower chord spheres and web members of the steel space frame to achieve accurate installation. The method for adjusting the installation position of the lower chord spheres in this embodiment utilizes the three-dimensional positioning space frame installation jig provided in Embodiment 1. This includes horizontal (X and Y directions) and vertical (Z direction) displacement adjustments. In this embodiment, the horizontal and vertical adjustments are not sequential; fine-tuning in either direction can be performed after the horizontal and vertical adjustments are completed. The specific adjustment method is as follows:

[0059] Carrier positioning:

[0060] Based on the diameter D of the chord ball and the design elevation H0, the hydraulic system automatically adjusts the upright to ΔH.

[0061] ΔH=H0+D / 2-(R1+R2)

[0062] In the formula, ΔH is the height adjustment amount; H0 is the design elevation; D is the diameter of the lower chord ball; R1 is the compression amount of the rubber pad; and R2 is the compensation value for the expansion and contraction of the pole caused by the ambient temperature.

[0063] The laser rangefinder scans the center point of the lower chord ball of the adjacent support frame that has been positioned, and verifies the coordinate deviation. The laser rangefinder scans the center point of the lower chord ball of the adjacent support frame that has been positioned, and measures the deviation ΔL = |L-L0| between the actual distance L and the design value L0. If ΔL > 2mm, the height adjustment of the upright 104 or the position correction of the chord ball limiter 110 is triggered to ensure that the node spacing meets the design requirements.

[0064] Adjustment of the X and Y positions of the bottom string ball:

[0065] The infrared beam emitted by the infrared locator 205 forms a 10cm×10cm grid above the slide rail 109, with a grid accuracy of 1mm. The coordinates (x,y) detected by the infrared locator 205 are aligned with the grid marks on the optical scale by the offset of the reflected mark points and the grid captured by the camera. When the deviation exceeds ±1mm, the bidirectional servo motor 111 is activated to correct the position of the spherical limiter 110.

[0066] Self-locking device activated:

[0067] The system determines that positioning is complete when the laser rangefinder and angle encoder detect a deviation of ≤±1mm in the X / Y / Z coordinates. The angle encoder monitors the height change of the upright 104 and feeds back the real-time data to the terminal, forming a closed-loop control. The electric screw lifting mechanism dynamically adjusts according to the difference between ΔH and the real-time height feedback from the encoder, ensuring an accuracy of ±1mm.

[0068] The angle encoder samples the pole tilt angle α at a frequency of 100Hz and calculates the real-time height using the formula ΔH=H0-(R1+R2)+K·α (K is the compensation coefficient).

[0069] ΔH is the height adjustment amount; H0 is the design elevation; D is the diameter of the lower chord ball; R1 is the compression amount of the rubber pad; and R2 is the compensation value for the expansion and contraction of the pole caused by ambient temperature.

[0070] The electric screw lifting mechanism dynamically adjusts the height of the adjusting rod (105) in 0.1mm increments based on the difference between ΔH and the encoder feedback value, until the deviation is ≤±1mm, thus forming a closed-loop control.

[0071] This invention enables automatic correction of the three-dimensional coordinates of nodes:

[0072] The three-dimensional coordinates to be determined for the center point of the lower chord ball supported by the current frame are (x, y, z), and the known three-dimensional coordinates for the center points of the lower chord balls of the adjacent already positioned frame supports are (x1, y1, z1). Let L1 be the actual straight-line distance between the current node and the adjacent node (obtained directly by the laser rangefinder).

[0073] The coordinates (x1, y1, z1) of adjacent nodes have been determined. The angle encoder provides the tilt angle α of pole 104 to correct the height deviation in the Z direction.

[0074] The tilt angle α of the angle encoder is used to calculate the height difference Δz = L measured sinα. Combined with the design elevation H0 and compensation parameters (such as the compression of the rubber pad), z = z1 + Δz is finally determined.

[0075] Geometric constraints: The coordinates (x, y, z) of the current node must satisfy the following conditions:

[0076] L1 measured = (x - x1) 2 +(y-y1) 2 +(z-z1) 2

[0077] This equation provides the geometric constraints between the current node and its neighboring nodes in three-dimensional space. It is used to verify or solve the three-dimensional distance between neighboring nodes, and then deduce the position of the current node through the geometric relationship.

[0078] Determining the length of the web member:

[0079] Based on the obtained coordinates (x1, y1, z1) and (x2, y2, z2) of the centers of the adjacent lower chord spheres, the length L2 of the web member is given by the formula. The calculations provide guidance for the installation of the web members.

[0080] Determining and adjusting the angle of the web members:

[0081] The web member is fitted with electrically operated rotating clamps at both ends, each clamp integrating an angle sensor; based on the center coordinates (x1, y1, z1) and (x2, y2, z2) of the adjacent lower chord sphere, the horizontal projection angle θ and vertical inclination angle ϕ of the web member are respectively:

[0082]

[0083] During adjustment, the electric clamp drives the web rod to rotate around the node ball according to θ and ϕ; the infrared positioner 205 monitors the coordinates of the web rod end points in real time and feeds them back to the signal comparator; if the measured angle deviation is >±1°, the bidirectional servo motor 111 triggers fine adjustment until the angle meets the standard, and closed-loop verification is performed.

[0084] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A three-dimensional positioning space frame installation jig, characterized in that, include Base (101); Upright pole (104); the upright pole (104) includes a hydraulic sleeve (106) and an adjusting upright pole (105); the lower end of the hydraulic sleeve (106) is connected to the base (101), and the upper end is sleeved with the adjusting upright pole (105); the adjusting upright pole (105) is axially raised and lowered under the action of hydraulic pressure provided in the hydraulic sleeve (106) to realize the height adjustment of the upright pole (104); A ball support platform (108) is horizontally fixed to the top of an adjusting rod (105). A circumferentially distributed sliding groove (109) is provided on the upper surface of the ball support platform (108). A ball adjustment and positioning assembly is provided within the sliding groove (109). The ball adjustment and positioning assembly includes a precision lead screw (112), a bidirectional servo motor (111), and a ball limiter (110). The precision lead screw (112) is disposed within the sliding groove. The bidirectional servo motor (111) is connected to the precision lead screw (112) via a transmission connection. The ball limiter (110) is fixed to the lead screw nut of the precision lead screw (112). Infrared positioning device (205); The infrared positioning device (205) is located at the four corners of the string ball support platform (108), emits cross infrared beams to form a planar coordinate system, covers the movement range of the slide (109), and detects the displacement coordinates of the string ball limiter (110) in real time. Angle encoder; the angle encoder is installed at the bottom of the pole (104) to monitor the verticality of the pole (104); Laser rangefinder; the laser rangefinder is horizontally installed on the edge of the chord ball support platform (108) and aligned with the center point of the lower chord ball of the adjacent frame support that has been positioned; the laser rangefinder is used to measure the straight distance between adjacent frame nodes, and combined with the tilt data of the angle encoder, the three-dimensional coordinates of the node are calculated by the cosine theorem.

2. The mounting frame according to claim 1, characterized in that, It also includes a signal fusion module; the signal fusion module is an analog circuit module, including a signal comparator and logic gate circuits; the angle encoder and the laser rangefinder are connected to the signal comparator through the CAN bus protocol, the signal comparator receives the distance data from the laser rangefinder and the tilt data from the angle encoder, and transmits them to the logic gate circuit through the CAN bus protocol; the logic gate circuit generates a pulse signal based on the comparison result between the received data and the original design data, and drives the hydraulic controller of the hydraulic sleeve (106) through the digital-to-analog converter, triggering the fine-tuning action of the hydraulic sleeve (106).

3. The mounting frame according to claim 2, characterized in that, The signal comparator sets the distance threshold L0±2mm and the tilt threshold ±0.1° through an adjustable resistor. If the measured value exceeds the limit, the signal comparator outputs a high-level signal to the logic gate circuit. The logic gate circuit generates a pulse signal, which drives the fine-tuning action of the hydraulic sleeve (106) through the solenoid valve of the hydraulic controller, forming a closed-loop control.

4. The mounting frame according to claim 1, characterized in that, It also includes a camera, which is aimed at the ball support platform (108) to take pictures; the surface of the ball support platform (108) is engraved with grid marks and is equipped with an optical scale; the camera is connected to the signal comparator through the image processing module, and the coordinates (x,y) detected by the infrared positioning instrument (205) are compared with the grid marks of the optical scale through the image to determine the offset between the reflected mark point and the grid; if the deviation exceeds ±1mm, the signal comparator outputs a correction command to the controller of the bidirectional servo motor (111) to drive the precision lead screw (112) to adjust the position of the ball limiter (110).

5. The mounting frame according to any one of claims 1 to 4, characterized in that, The slide groove (109) is provided in more than 3 lines and is evenly distributed along the center circumference of the ball support platform (108); the ball limiter (110) is a V-shaped groove plate structure with an arc-shaped concave surface in the middle, which fits against the outer wall of the lower ball and is radially clamped by the precision screw (112).

6. The mounting frame according to claim 5, characterized in that, The ball limiter (110) is equipped with a self-locking device; the self-locking device is an electromagnetic lock and is integrated into the bottom of the V-groove.

7. A method for positioning a lower chord ball, using the mounting frame as described in claim 5 to position the lower chord ball, characterized in that, Includes the following: (1) Adjusting the horizontal direction of the lower string ball A bidirectional servo motor (111) drives a precision lead screw (112) to rotate, which in turn moves the ball limiter (110); an infrared positioning instrument (205) detects the coordinates (x, y) of the ball limiter (110) in real time through reflective markers. The coordinates (x, y) detected by the infrared positioning device (205) are aligned with the grid marks of the optical scale by the offset of the reflected mark points and the grid captured by the camera. When the deviation exceeds ±1mm, the bidirectional servo motor (111) starts to correct the position of the chord ball limiter (110). (2) Adjustment of verticality of the pole The laser rangefinder and the angle encoder are connected to the signal fusion module via the CAN bus protocol to transmit distance and tilt angle data in real time. The angle encoder judges the verticality of the upright based on the distance data between the center points of the lower chord balls of the adjacent support frame that have been positioned by the laser rangefinder. The judgment method is as follows: based on the deviation between the distance L between the adjacent support frame measured by the laser rangefinder and the theoretical design value L0, combined with the tilt angle α of the angle encoder, if |L-L0|>threshold or |α|>0.1°, the signal comparator outputs an over-limit signal to the logic gate circuit. The logic gate circuit generates a pulse signal to trigger the hydraulic controller of the hydraulic sleeve (106) and drive the adjusting upright (105) to perform verticality correction. (3) Adjustment of the lifting height of the pole The method for calculating the height adjustment amount is as follows: ΔH=H0+D / 2-(R1+R2) In the formula, ΔH is the height adjustment amount; H0 is the design elevation; D is the diameter of the lower chord ball; R1 is the rubber pad compression amount; and R2 is the pole expansion and contraction compensation value caused by ambient temperature. An angle encoder monitors the height change of the upright (104). If the upright tilts, the angle encoder feeds back the tilt angle α to the signal fusion module. Combined with the distance L between adjacent frames measured by the laser rangefinder, the height change is calculated by the formula ΔH=L·sinα to achieve closed-loop dynamic adjustment. The hydraulic sleeve (106) is dynamically adjusted according to the difference between ΔH and the real-time height fed back by the encoder, and the adjustment is made with an accuracy of ±1mm.

8. The method for positioning the lower chord ball according to claim 7, characterized in that, By using the known coordinates (x1, y1, z1) of adjacent nodes and the measured distance L, the three-dimensional coordinates (x, y, z) of the current node are calculated to ensure that the node position meets the design requirements.

9. A method for positioning a web member, using the mounting frame as described in claim 5 to position the web member, characterized in that, Based on the center coordinates (x1, y1, z1) and (x2, y2, z2) of the adjacent lower chord spheres, the length L of the web member is given by the formula The calculations provide guidance for the installation of the web members.

10. The web member positioning method according to claim 9, characterized in that, The web member is equipped with electrically driven rotating clamps at both ends, and the clamps integrate angle sensors. Based on the center coordinates (x1, y1, z1) and (x2, y2, z2) of the adjacent lower chord spheres, the horizontal projection angle θ and vertical tilt angle ϕ of the web member are respectively:

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