Device and method for measuring dynamic displacement in normal plane of stay cable in different directions based on mechanical decoupling

Abstract

The invention discloses a device and a method for measuring dynamic displacement in a normal plane of a stay cable in different directions based on mechanical decoupling, and the device comprises a cable clamp which is fixedly disposed on the stay cable; one end of the transverse displacement amplification lever is rotationally connected with the cable clamp through a pin shaft, a lever transverse guide rod is arranged at the other end of the transverse displacement amplification lever, and a hollow lever vertical guide groove is formed in the middle of the transverse displacement amplification lever; the fixing plate assembly comprises an upper fixing plate and a lower fixing plate which are arranged in parallel; one end of the upper fixing plate and one end of the lower fixing plate are correspondingly provided with a plurality of transverse limiting pin holes arranged in the axial direction, the middle portions are correspondingly provided with transverse guide grooves, and the other ends are correspondingly provided with vertical guide grooves. Displacement in a stay cable normal plane is physically separated into independent output in two orthogonal directions, high-precision measurement through a one-way displacement measurement device becomes possible, and therefore economical, applicable and high-precision stay cable dynamic displacement measurement is achieved.

Description

Technical Field

[0001] The present invention relates to the field of stay cable detection, and more specifically to a device and method for measuring the in-plane dynamic displacement of a stay cable based on mechanical decoupling. Background Art

[0002] Stay cables are key components of cable-stayed bridges, bearing and transmitting loads. They are prone to vibration under external excitations such as wind and traffic loads. Their vibration displacements in the normal plane directly reflect the stress state and vibration characteristics. A thorough understanding of the direction, magnitude, and temporal characteristics of these vibration displacements is crucial for effectively addressing out-of-plane vibrations in stay cables and improving the effectiveness and durability of external dampers. High-precision measurement of stay cable vibrations is crucial to clarifying their vibration characteristics. However, direct and accurate measurement of complex and variable multi-degree-of-freedom vibration displacements in environments such as inclement weather presents considerable technical challenges. In particular, simultaneous high-precision measurement of stay cable displacements, when there are orders of magnitude differences between the in-plane vertical and transverse bridge displacements, places high demands on both measurement methods and equipment. This is not only difficult to achieve but also prohibitively expensive, making it difficult to scale. Therefore, convenient and low-cost means of accurately obtaining the normal plane displacements and their variations in the stay cables is crucial for improving the out-of-plane vibration control effectiveness of external vibration control devices and ensuring the operational safety of the structure.

[0003] To achieve high-precision measurement of these multi-DOF vibration displacements, decomposing them into independent in-plane vertical and lateral components for separate measurement while eliminating mutual interference between these directions would significantly improve the device's environmental adaptability, reduce complexity, and reduce costs. Traditional decoupling methods rely primarily on algorithms to mathematically decouple sensor signals (e.g., separating coupled signals through matrix operations), requiring high-precision sensors and requiring complex calculations.

[0004] The existing technology for measuring the vibration displacement of the cable still has the following deficiencies: (1) When directly using a cable sensor to measure the displacement of the cable, a fixed position is required as a reference point, and it is difficult to find a reference point that meets the requirements near the cable. In addition, the cable sensor is only suitable for single-direction displacement measurement, which is difficult to meet the multi-degree-of-freedom displacement measurement requirements of the cable under the influence of the environment and traffic loads. (2) The measurement method based on the Beidou satellite system is still insufficient for the measurement accuracy of small-amplitude dynamic displacement, and the equipment cost is high, which is not conducive to large-scale promotion and use. (3) The traditional method of taking the vibration image of the cable with a single camera and combining it with the edge line image processing algorithm to extract the displacement information requires a wide field of view and fixed video equipment, and it is difficult to accurately obtain the multi-dimensional vibration displacement of the cable. It has poor environmental adaptability and the image processing technology is also relatively complex. (4) When installing an accelerometer on the cable and obtaining the displacement through integral operation, the selection of boundary conditions is very likely to introduce large errors, affecting the accuracy of the measurement results.

[0005] The above-mentioned deficiencies limit the in-depth study of the vibration characteristics of the inclined cables and also restrict the effectiveness of the existing damping devices in the vibration control of the inclined cables. Summary of the Invention

[0006] The purpose of this invention is to provide a device and method for measuring the normal-plane dynamic displacement of a stay cable based on mechanical decoupling. This device decomposes the multi-degree-of-freedom vibration (complex coupled motion) of the stay cable in the normal plane into independent lateral and vertical components. The mechanical structure eliminates mutual interference between these directions, physically separating the displacement of the stay cable in the normal plane into two independent outputs in orthogonal directions. This enables high-precision measurement using a unidirectional displacement measurement device, thereby achieving economical, applicable, and high-precision dynamic displacement measurement of the stay cable. The data obtained will be directly applied to the study of the vibration characteristics of the stay cable and the design optimization of its external vibration reduction device, significantly improving the vibration reduction effect, especially the transverse (out-of-plane) vibration suppression effect, and enhancing the durability of the stay cable. By directly separating the displacement components at the physical level through mechanical design and preemptively eliminating coupling interference, this method represents a more fundamental displacement decoupling method compared to algorithmic decoupling.

[0007] The technical solution adopted by the present invention to solve this technical problem is: a device for measuring the in-plane dynamic displacement direction based on the inclined cable method of mechanical decoupling, comprising: Cable clamp, fixedly installed on the inclined cable; A lateral displacement amplifying lever, one end of which is rotatably connected to the cable clamp via a pin, the other end of which is provided with a lever lateral guide rod, and a hollow lever vertical guide groove is provided in the middle; The fixing plate assembly includes an upper fixing plate and a lower fixing plate arranged in parallel; one end of the upper and lower fixing plates is provided with a plurality of transverse limit pin holes arranged in the axial direction, the middle part is provided with a transverse guide groove, and the other end is provided with a vertical guide groove; A bottom plate, fixedly connected to the bridge deck and fixedly connected to the upper fixed plate and the lower fixed plate; A transverse limit pin is sequentially passed through the transverse limit pin hole of the upper fixing plate, the lever vertical guide groove and the transverse limit pin hole of the lower fixing plate, and is fixed to the lower fixing plate; The transverse displacement measuring shaft passes through the transverse guide groove of the upper fixing plate, the vertical guide groove of the lever and the transverse guide groove of the lower fixing plate in sequence; Transverse displacement meter, used to measure the displacement of the transverse displacement measuring shaft in the transverse guide groove; A vertical displacement measuring axis passes through the vertical guide groove of the upper fixed plate and the vertical guide groove of the lower fixed plate in sequence; a limit spring is provided below the vertical displacement measuring axis and is parallel to the upper and lower fixed plates. The other end of the limit spring is fixed to the bottom plate. When the limit spring is in its free state, its length can reach the top of the vertical guide groove of the upper and lower fixed plates. The vertical displacement meter is used to measure the displacement of the vertical displacement measuring axis in the vertical guide groove.

[0008] As a further solution of the present invention, it also includes stiffening ribs vertically arranged on both sides of the bottom surface of the lower fixing plate.

[0009] As a further solution of the present invention, the lateral displacement amplifying lever is located between the upper fixing plate and the lower fixing plate, and the three are rotatably connected via a lateral limiting pin.

[0010] As a further solution of the present invention, the lateral displacement meter and the vertical displacement meter are laser displacement meters.

[0011] As a further solution of the present invention, the lateral displacement meter and the vertical displacement meter are transmitted to a wireless router via a network cable, and then remotely transmitted by the wireless router and uploaded to a cloud acquisition system.

[0012] As a further solution of the present invention, the vertical displacement measuring shaft and the horizontal displacement measuring shaft are both assembled structures.

[0013] The present invention also provides a measurement method based on the device, comprising: When the inclined cable undergoes dynamic displacement in any direction, the displacement of the lateral displacement measuring axis in the lateral guide groove is measured by the lateral displacement meter, and the displacement of the vertical displacement measuring axis in the vertical guide groove is measured by the vertical displacement meter. According to the measured lateral displacement of the lateral displacement measuring axis and the vertical displacement of the vertical displacement measuring axis, the lateral displacement component x0 and the vertical displacement component y0 of the inclined cable are calculated.

[0014] The present invention has at least the following beneficial effects: the device realizes real-time and high-precision measurement of the in-plane vibration displacement law of the cable-stayed cable, can be used to study the vibration characteristics of the cable-stayed cable, and guide the design optimization of the external damper, thereby improving the vibration suppression efficiency and environmental adaptability of the cable-stayed cable and reducing the maintenance cost of the bridge.

[0015] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of the device for measuring the in-plane dynamic displacement using the cable-stayed method of the present invention; Figure 2 This is a partial enlarged view of the device for measuring the in-plane dynamic displacement using the cable-stayed method of the present invention; Figure 3 Schematic diagram of the lateral displacement amplification lever of the present invention; Figure 4 Schematic diagram of the upper fixing plate and the lower fixing plate of the present invention; Figure 5 It is a side view of the device for measuring the in-plane dynamic displacement using the cable-stayed method of the present invention; Figure 6 This is a diagram of the side of the in-plane dynamic displacement directional measurement device provided with a limit spring according to the inclined cable method of the present invention; Figure 7 This is a partial diagram of the arrangement of the lateral displacement measurement axis of the present invention; Figure 8 yes Figure 7 Side view of; Figure 9 This is a principle analysis diagram of the device after the inclined cable moves.

[0017] Among them, 1- oblique cable, 2-cable clamp, 3-lateral displacement amplification lever, 4-lever lateral guide rod, 5-lever vertical guide groove, 6-upper fixed plate, 7-lower fixed plate, 8-base plate, 9-lateral limit pin, 10-lateral limit pin hole, 11-lateral displacement measuring shaft, 12-lateral displacement meter, 13-vertical displacement measuring shaft, 14-vertical displacement meter, 15-shaft section A, 16-shaft section B, 17-rolling bearing, 18-bearing cover plate, 19-countersunk bolt, 20-limit spring, 21-lateral guide groove, 22-vertical guide groove. DETAILED DESCRIPTION

[0018] The present invention is described in detail and completely below with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on this description. Before describing the present invention with reference to the accompanying drawings, it should be noted that the technical solutions and technical features provided in various parts of the present invention, including those described below, may be combined with each other unless they conflict.

[0019] In addition, the embodiments of the present invention described below are generally only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making any creative efforts should fall within the scope of protection of the present invention.

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows: like Figures 1 to 9 As shown, the present invention provides a device for measuring the dynamic displacement of a stay cable in a normal plane based on mechanical decoupling, comprising: A cable clamp 2 is fixedly installed on the inclined cable 1; A lateral displacement amplifying lever 3, one end of which is rotatably connected to the cable clamp 2 via a pin, and the other end of which is vertically provided with a lever lateral guide rod 4, and a hollow lever vertical guide groove 225 is provided in the middle portion; The fixing plate assembly includes an upper fixing plate 6 and a lower fixing plate 7 arranged in parallel; one end of the upper and lower fixing plates 7 is provided with a plurality of transverse limit pin holes 10 arranged in the axial direction, the middle portion is provided with a transverse guide groove 21, and the other end is provided with a vertical guide groove 22; A bottom plate 8, fixedly connected to the bridge deck and fixedly connected to the upper fixed plate 6 and the lower fixed plate 7; The transverse limit pin 9 is sequentially passed through the transverse limit pin hole 10 of the upper fixed plate 6, the lever vertical guide groove 225 and the transverse limit pin hole 10 of the lower fixed plate 7, and is fixed to the lower fixed plate 7; the position of the transverse limit pin 9 in the transverse limit pin hole 10 of the lower fixed plate 7 and the upper fixed plate 6 is adjusted to change the position of the fulcrum of the transverse displacement amplification lever 3, thereby achieving the optimal arrangement as needed.

[0021] The lateral displacement measuring shaft 11 passes through the lateral guide groove 21 of the upper fixing plate 6, the lever vertical guide groove 225, and the lateral guide groove 21 of the lower fixing plate 7 in sequence; the lateral displacement measuring shaft 11 is loosely fitted in each guide groove, and its axis is perpendicular to the upper and lower fixing plates 7; A lateral displacement meter 12 is used to measure the displacement of the lateral displacement measuring shaft 11 in the lateral guide groove 21; The vertical displacement measuring shaft 13 passes through the vertical guide groove 22 of the upper fixed plate 6 and the vertical guide groove 22 of the lower fixed plate 7 in sequence; a limit spring 20 is provided below the vertical displacement measuring shaft 13 and is parallel to the upper and lower fixed plates 7, and the two are fixed by a fixing box. The other end of the limit spring 20 is fixed to the bottom plate 8 by the fixing box. In this embodiment, the fixing box is divided into a box seat and a clamping seat. The box seat is directly fixed to the vertical displacement measuring shaft 13, and the clamping seat is used to clamp the spring. The limit spring 20 is set so that its length can reach the top of the vertical guide groove 22 of the upper and lower fixed plates 7 when it is in its free state; in a preferred solution of this embodiment, in the assembled device, the vertical displacement measuring shaft 13 is basically located in the middle of the vertical guide groove 22, the spring is in a compressed state, and when the lever transverse guide rod 4 is pressed downward, the spring can be compressed to make the vertical displacement measuring shaft 13 reach the bottom of the vertical guide groove 22. Specifically, when the inclined cable 1 moves in any direction, Figure 9 For example, the lateral displacement amplification lever 3 rotates counterclockwise around point B, from AE to DC, and the corresponding lever lateral guide rod 4 also rotates. Under the rotational force of the lever lateral guide rod 4, the vertical displacement measurement axis 13 is pressed to move downward along the vertical guide groove 22.

[0022] The vertical displacement meter 14 is used to measure the displacement of the vertical displacement measuring shaft 13 in the vertical guide groove 22 .

[0023] This technical solution may also include the following technical details to better achieve the technical effect: it also includes stiffening ribs vertically arranged on both sides of the bottom surface of the lower fixing plate 7. The stiffening ribs are symmetrically arranged on both sides of the lower fixing plate 7 and are arranged vertically along the lower fixing plate 7 to ensure the stability of the entire device during operation by enhancing the structural strength.

[0024] This technical solution may further include the following technical details to better achieve the technical effect: the lateral displacement amplification lever 3 is located between the upper fixed plate 6 and the lower fixed plate 7, and the three are rotationally connected through a lateral limit pin 9.

[0025] This technical solution can also include the following technical details to better achieve the technical effect: the lateral displacement meter 12 and the vertical displacement meter 14 are laser displacement meters, which are installed on the surface of the upper fixed plate 6 to achieve accurate measurement of the displacement of the lateral displacement measurement axis 11 and the vertical displacement measurement axis 13. The laser displacement can adopt any power supply mode such as solar panels.

[0026] This technical solution may also include the following technical details to better achieve the technical effect: the lateral displacement meter 12 and the vertical displacement meter 14 are transmitted to the wireless router via the network cable, and then remotely transmitted by the wireless router to the cloud acquisition system for storage, analysis and display.

[0027] The present technical solution may also include the following technical details to better achieve the technical effect: the vertical displacement measuring shaft 13 and the lateral displacement measuring shaft 11 are both assembled structures. In this embodiment, the vertical displacement measuring shaft 13 and the lateral displacement measuring shaft 11 have the same structure. The vertical displacement measuring shaft 13 includes a cylindrical shaft segment A15 and a shaft segment B16. The shaft segment A15 has an internal threaded hole, and the shaft segment B16 has a threaded column matching the internal threaded hole. After the shaft segment A15 and the shaft segment B16 are threadedly connected, a cylindrical structure with the same outer diameter is formed. The bottom surface of the segment of the shaft segment B16 passing through the upper fixed plate 6 is a plane, so that the optical fiber shot out of the vertical displacement meter 14 is always shot on the plane of the corresponding segment of the shaft segment B16. Preferably, the segment is a regular hexagonal prism structure. Similarly, the side surface of the segment of the lateral displacement measuring shaft 11 passing through the upper fixed plate 6 is also a plane. Preferably, the segment is a regular hexagonal prism structure.

[0028] The vertical displacement measuring shaft 13 is located in the vertical guide groove 22 of the upper and lower fixed plates 7 and is installed with a rolling bearing 17. The outer ring of the rolling bearing 17 is rollingly arranged in the vertical guide groove 22. The upper and lower fixed plates 7 are both installed with bearing cover plates 18 on the inner and outer sides of the vertical guide groove 22. The opening of the bearing cover plate 18 is slightly smaller than the vertical guide groove 22 to limit the rolling bearing 17. It is preferred to slot the bearing cover plate 18 on the upper and lower fixed plates 7 and fix it with countersunk bolts 19 so that the bearing cover plate 18 and the corresponding fixed plate are in the same plane.

[0029] The lateral displacement measuring shaft 11 is located in the lateral guide groove 21 of the upper and lower fixed plates 7 and is installed with a rolling bearing 17. The outer ring of the rolling bearing 17 is rollingly arranged in the lateral guide groove 21. The upper and lower fixed plates 7 are both installed with bearing cover plates 18 on both the inner and outer sides of the lateral guide groove 21. The opening of the bearing cover plate 18 is slightly smaller than the lateral guide groove 21 to limit the rolling bearing 17. It is preferred to slot the bearing cover plate 18 on the upper and lower fixed plates 7 and fix it with countersunk bolts 19 so that the bearing cover plate 18 and the corresponding fixed plate are in the same plane.

[0030] The present invention also provides a method for measuring an in-plane dynamic displacement directional measurement device using a stay cable method based on mechanical decoupling, comprising: When the inclined cable 1 undergoes dynamic displacement in any direction, the lateral displacement amplification lever 3 will synchronously generate vertical movement and rotate around the lateral limit pin 9, the lateral displacement measuring axis 11 will undergo lateral displacement relative to the upper and lower fixed plates 7, and the vertical displacement measuring axis 13 will undergo vertical displacement relative to the upper and lower fixed plates 7. The displacement of the lateral displacement measuring axis 11 in the lateral guide groove 21 is measured by the lateral displacement meter 12, and the displacement of the vertical displacement measuring axis 13 in the vertical guide groove 22 is measured by the vertical displacement meter 14. According to the measured lateral displacement of the lateral displacement measuring axis 11 and the vertical displacement of the vertical displacement measuring axis 13, the lateral displacement component and the vertical displacement component of the inclined cable 1 are calculated.

[0031] If the cable 1 undergoes lateral and vertical displacement simultaneously, the calculation principle is as follows: Figure 9 As shown, AE represents the initial position of the lateral displacement amplification lever 3, CD represents the position of the lateral displacement amplification lever 3 after movement, point B represents the lateral limit pin 9, point K represents the lateral displacement measurement axis 11, circle O1 is the center of the initial position of the vertical measurement axis before the inclined cable 1 moves, circle O2 is the center of the position of the vertical measurement axis after the inclined cable 1 moves, A2 is the tangent point with circle O2, and O3 is the intersection of the extended line EA and CA2 。

[0032] In the figure, the vertical displacement EE of the inclined cable 1 is ’ =y0, lateral displacement DE of cable 1 ’ =x0. Assume the total length of the lever AE = L, BE = L0, BA = L1, and the radius of the circular tube of the vertical displacement axis is r , horizontal test value HK=t1, vertical test value O1O 2= t0, deduced by the principle of similar triangles, can be obtained: ; ; ; Combining the above two equations, we can get: ; In the formula .

[0033] In the above technical solution, the physical decoupling of the dynamic displacement in the normal plane of the cable-stayed cable 1 is achieved through this type of specific mechanical structure, and the multi-degree-of-freedom displacement values ​​are converted into two independent output displacement values, namely vertical and lateral displacement values. This simplifies the measurement process, improves the sensitivity and accuracy of the lateral displacement measurement of the cable-stayed cable 1, and solves the problem of insufficient sensitivity of traditional sensors in measuring small transverse displacements of the cable-stayed cable 1. The method of combining contactless measurement with leverage is intuitive and concise.

[0034] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A device for measuring in-plane dynamic displacement using a stay cable method based on mechanical decoupling, characterized in that: include: Cable clamp, fixedly installed on the inclined cable; A lateral displacement amplifying lever, one end of which is rotatably connected to the cable clamp via a pin, the other end of which is provided with a lever lateral guide rod, and a hollow lever vertical guide groove is provided in the middle; The fixing plate assembly includes an upper fixing plate and a lower fixing plate arranged in parallel; one end of the upper and lower fixing plates is provided with a plurality of transverse limit pin holes arranged in the axial direction, the middle part is provided with a transverse guide groove, and the other end is provided with a vertical guide groove; A bottom plate, fixedly connected to the bridge deck and fixedly connected to the upper fixed plate and the lower fixed plate; A transverse limit pin is sequentially passed through the transverse limit pin hole of the upper fixing plate, the lever vertical guide groove and the transverse limit pin hole of the lower fixing plate, and is fixed to the lower fixing plate; The transverse displacement measuring shaft passes through the transverse guide groove of the upper fixing plate, the vertical guide groove of the lever and the transverse guide groove of the lower fixing plate in sequence; Transverse displacement meter, used to measure the displacement of the transverse displacement measuring shaft in the transverse guide groove; A vertical displacement measuring axis passes through the vertical guide groove of the upper fixed plate and the vertical guide groove of the lower fixed plate in sequence; a limit spring is provided below the vertical displacement measuring axis and is parallel to the upper and lower fixed plates. The other end of the limit spring is fixed to the bottom plate. When the limit spring is in its free state, its length can reach the top of the vertical guide groove of the upper and lower fixed plates. The vertical displacement meter is used to measure the displacement of the vertical displacement measuring axis in the vertical guide groove.

2. The device for measuring in-plane dynamic displacement using the mechanical decoupling-based cable method according to claim 1, characterized in that: It also includes stiffening ribs, which are vertically arranged on both sides of the bottom surface of the lower fixed plate.

3. The device for measuring in-plane dynamic displacement using the mechanical decoupling-based cable method according to claim 1, characterized in that: The lateral displacement amplifying lever is located between the upper fixing plate and the lower fixing plate, and the three are rotatably connected via a lateral limiting pin.

4. The device for measuring in-plane dynamic displacement using the mechanical decoupling-based cable method according to claim 1, characterized in that: The lateral displacement meter and the vertical displacement meter are laser displacement meters.

5. The device for measuring in-plane dynamic displacement using the mechanical decoupling-based cable method according to claim 4, characterized in that: The lateral displacement meter and vertical displacement meter are transmitted to the wireless router via the network cable, and then the wireless router remotely transmits and uploads the data to the cloud acquisition system.

6. The device for measuring in-plane dynamic displacement using the mechanical decoupling-based cable method according to claim 1, characterized in that: The vertical displacement measuring shaft and the horizontal displacement measuring shaft are both assembled structures.

7. A measurement method based on the device according to any one of claims 1 to 6, characterized in that: include: When the inclined cable undergoes dynamic displacement in any direction, the displacement of the lateral displacement measuring axis in the lateral guide groove is measured by the lateral displacement meter, and the displacement of the vertical displacement measuring axis in the vertical guide groove is measured by the vertical displacement meter. According to the measured lateral displacement of the lateral displacement measuring axis and the vertical displacement of the vertical displacement measuring axis, the lateral displacement component x0 and the vertical displacement component y0 of the inclined cable are calculated.

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