Stay cable multi-dimensional vibration displacement measuring device and method based on composite lever mechanism

Abstract

The invention discloses a stay cable multi-dimensional vibration displacement measuring device and method based on a composite lever mechanism, and the device comprises a transverse displacement amplification lever, a vertical displacement amplification lever, an upper fixed plate, and a lower fixed plate. A transverse limiting pin and a vertical limiting pin are arranged in hollow guide grooves of the transverse displacement amplification lever and the vertical displacement amplification lever in a penetrating mode respectively, and a transverse displacement measuring shaft penetrates transverse guide grooves of the upper fixing plate and the lower fixing plate and hollow guide grooves of the transverse displacement amplification lever. The vertical displacement measuring shaft penetrates through vertical guide grooves of the upper fixing plate and the lower fixing plate and a hollow guide groove of the vertical displacement amplifying lever, and two laser displacement meters are arranged on the fixing plates and used for measuring the moving distance of the transverse displacement measuring shaft and the moving distance of the vertical displacement measuring shaft. Real-time high-precision measurement of the vibration displacement rule in a stay cable normal plane is achieved, the device can be used for studying the vibration characteristics of the stay cable, design optimization of an external damper is guided, the vibration suppression efficiency and environmental adaptability of the stay cable are improved, and the maintenance cost of a bridge is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration displacement measurement of a stay cable, and more particularly to a device and method for measuring the multi-dimensional vibration displacement of a stay cable based on a composite lever mechanism. Background Art

[0002] To suppress the vibrations of stay cables caused by external excitations such as wind and traffic loads, vibration control measures often involve placing internal damping rings within steel casings and installing external dampers at a certain height within the beam section. While internal damping rings provide circumferential and omnidirectional vibration reduction, their proximity to the cable anchorage results in poor damping. External dampers are far from ideal at suppressing out-of-plane vibrations of stay cables. In recent years, failure or even damage to external dampers in response to significant cable vibrations has been a frequent occurrence, primarily due to inaccurate understanding of the direction, magnitude, and temporal characteristics of the multi-degree-of-freedom vibration displacements of the cable within its normal plane.

[0003] In order to clarify the vibration characteristics of the cable-stayed cables, it is crucial to perform high-precision measurements on them. However, it is technically difficult to directly and accurately measure the complex and changeable multi-degree-of-freedom vibration displacements in environments such as severe weather. In particular, the simultaneous high-precision measurement of the vertical displacement in the cable-stayed plane and the transverse bridge displacement when there are orders of magnitude differences places high demands on both the measurement methods and equipment. This is not only difficult to achieve, but also expensive and difficult to promote. Therefore, the convenient and low-cost accurate acquisition of the displacement value in the cable-stayed plane and its variation pattern is of great significance for improving the out-of-plane vibration control effect of the external vibration control device and ensuring the safe operation of the structure.

[0004] 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.

[0005] In addition, 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 transverse and vertical vibration displacement of the cable at the same time. The environmental adaptability is poor, 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.

[0006] The above-mentioned shortcomings have limited the in-depth study of the vibration characteristics of the inclined cable and also restricted the effectiveness of existing damping devices in controlling the vibration of the inclined cable. Therefore, the present application proposes a device and method for enhancing the multi-dimensional vibration displacement measurement of the inclined cable based on a composite lever mechanism. Summary of the Invention

[0007] One object of the present invention is to provide a multi-dimensional vibration displacement increment device and method for a cable-stayed cable based on a composite lever mechanism, which realizes real-time and high-precision measurement of the vibration displacement law of the cable-stayed cable in the plane. The device can be used to study the vibration characteristics of the cable-stayed cable and guide the design optimization of external dampers, thereby improving the vibration suppression efficiency and environmental adaptability of the cable-stayed cable and reducing the maintenance cost of the bridge.

[0008] In order to solve the above technical problems, the present invention provides a multi-dimensional vibration displacement measuring device for a stayed cable based on a composite lever mechanism, comprising a lateral displacement amplifying lever perpendicular to the axis of the stayed cable, a vertical displacement amplifying lever forming an L-shape with the lateral displacement amplifying lever, and an upper fixed plate and a lower fixed plate in which the lateral displacement amplifying lever and the vertical displacement amplifying lever are clamped. The upper fixed plate and the lower fixed plate are both fixed L-shaped structures and are arranged parallel to the plane where the lateral displacement amplifying lever and the vertical displacement amplifying lever are located. The lateral displacement amplifying lever and the vertical displacement amplifying lever are both provided with a hollow guide groove along the middle part of the axial direction thereof, and the lateral limit pin and the vertical limit pin, which are vertically and fixedly connected to the upper fixed plate and the lower fixed plate, are respectively passed through the lateral displacement amplifying lever and the vertical limit pin. The lever and the vertical displacement amplifying lever have corresponding transverse guide grooves and vertical guide grooves, and the upper fixed plate and the lower fixed plate are also provided with corresponding transverse guide grooves and vertical guide grooves. The transverse displacement measuring axis passes through the transverse guide groove of the upper fixed plate, the hollow guide groove of the transverse displacement amplifying lever and the transverse guide groove of the lower fixed plate in sequence, and the vertical displacement measuring axis passes through the vertical guide groove of the upper fixed plate, the hollow guide groove of the vertical displacement amplifying lever and the vertical guide groove of the lower fixed plate in sequence. The upper end of the transverse displacement amplifying lever is hinged on the inclined cable, and the lower end is hinged to one end of the vertical displacement amplifying lever, and the other end of the vertical displacement amplifying lever is freely set; two laser displacement meters are provided on the upper fixed plate or the lower fixed plate, which are used to measure the linear movement distance of the transverse displacement measuring axis and the vertical displacement measuring axis respectively.

[0009] Preferably, the stay cable is provided with a cable clamp, and the cable clamp is provided with a pair of cable clamp ear plates, which are rotatably connected to the upper end of the lateral displacement amplification lever through a rotating pin.

[0010] Preferably, the upper fixing plate and the lower fixing plate are both fixed by a bottom plate embedded in the top surface of the main beam, and a plurality of stiffening ribs are provided on both sides of the lower fixing plate to increase structural stability.

[0011] Preferably, a plurality of limit pin holes are provided on the upper fixed plate and the lower fixed plate corresponding to the positions of the horizontal limit pins and the vertical limit pins, which are used to selectively set the horizontal limit pin and the vertical limit pin in one of the limit pin holes, thereby realizing the optimal arrangement of the fulcrums of the horizontal displacement amplification lever and the vertical displacement amplification lever as required.

[0012] Preferably, the lateral limit pin is arranged at the upper part of the lateral displacement amplification lever, the lateral displacement measuring axis is arranged at the lower part of the lateral displacement amplification lever, the vertical limit pin is arranged close to the lateral displacement amplification lever, and the vertical displacement measuring axis is arranged away from the lateral displacement amplification lever.

[0013] Preferably, the hollow guide groove of the vertical displacement amplifying lever is arc-shaped.

[0014] The present invention also provides a method for measuring the multi-dimensional vibration displacement of a cable-stayed cable based on a composite lever mechanism. First, the multi-dimensional vibration displacement of the cable-stayed cable is amplified by a lateral displacement amplification lever and a vertical displacement amplification lever, and the amplification value is obtained; secondly, through a decoupling algorithm and combined with the displacement amplification value, the transverse and vertical displacement data in the normal plane of the cable-stayed cable are output.

[0015] Preferably, the linear movement distances of the lateral displacement measuring axis and the vertical displacement measuring axis are t1 and t0 respectively; initially, the length of the lateral displacement amplifying lever is L, the distance from the lateral limit pin to the lateral displacement measuring axis is L1, the distance from the vertical limit pin to the bottom end of the lateral displacement amplifying lever is L2, and the distance from the vertical limit pin to the vertical displacement measuring axis is L3; after the multi-dimensional vibration of the inclined cable, the angle of rotation of the lateral displacement amplifying lever along the lateral limit pin is ; Then, through the decoupling algorithm, the output displacement data of the transverse bridge direction and the vertical bridge direction in the normal plane of the inclined cable are Δ1 and Δ0 respectively. The calculation formula is as follows: ; ; in, .

[0016] The present invention has at least the following beneficial effects: 1. The measurement device and method of the present invention achieve physical decoupling of the dynamic displacement of the cable in the normal plane through a specific mechanical structure (a directional conduction mechanism + an orthogonal guide groove group). This decomposes the cable's multi-degree-of-freedom vibration (complex coupled motion) in the normal plane into lateral and vertical components in independent directions. The mechanical structure eliminates mutual interference between these directions, physically separating the cable's displacement in the normal plane into two independent outputs in orthogonal directions. This enables high-precision measurement using a unidirectional displacement measurement device. Combined with the composite lever mechanism's amplification of the cable's lateral and vertical displacement components in the normal plane, displacement measurement accuracy is improved. This simplifies the measurement process, improves the sensitivity and accuracy of cable lateral displacement measurements, and addresses the challenge of traditional sensors' insufficient sensitivity in measuring small transverse cable displacements.

[0017] 2. The measurement device and method of this invention enable real-time, high-precision measurement of the in-plane vibration displacement patterns of stay cables. The data obtained will be directly applied to the study of the vibration characteristics of stay cables and the design and optimization of external vibration dampers. This will be used to study the vibration characteristics of stay cables and guide the design and optimization of external dampers. This significantly improves vibration damping, especially in the transverse (out-of-plane) direction, enhancing the durability and environmental adaptability of stay cables and reducing bridge maintenance costs. The method, which combines contactless measurement with a lever, is intuitive and simple.

[0018] 3. The measuring device and method of the present invention directly separate the displacement components at the physical level through mechanical design, and preemptively eliminate coupling interference. Compared with algorithm decoupling, it is a more basic displacement decoupling method, which greatly improves the environmental adaptability of the equipment and reduces the equipment complexity and economic cost.

[0019] 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

[0020] Figure 1 It is a side view of the overall structure of the present invention; Figure 2 It is a front cross-sectional view of the overall structure of the present invention; Figure 3 It is a front view of the overall structure of the present invention; Figure 4 This is a diagram showing the calculation principle of the present invention.

[0021] Description of reference numerals: 1. Stay cable, 2. Cable clamp, 3. Rotating pin, 4. Lateral displacement amplification lever, 5. Horizontal limit pin, 6. Lateral displacement measuring shaft, 7. Vertical limit pin, 8. Vertical displacement amplification lever, 9. Vertical displacement measuring shaft, 10. Upper fixed plate, 11. Lower fixed plate, 12. Horizontal guide groove, 13. Vertical guide groove, 14. Bottom plate, 15. Hollow guide groove. DETAILED DESCRIPTION

[0022] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings so that those skilled in the art can implement it according to the description.

[0023] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified; in the description of the present invention, the terms "horizontal", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0024] like Figures 1 to 3As shown, the present invention provides a multi-dimensional vibration displacement measuring device for a stayed cable based on a composite lever mechanism, comprising a lateral displacement amplifying lever 4 perpendicular to the axis of the stayed cable 1, a vertical displacement amplifying lever 8 forming an L-shape with the lateral displacement amplifying lever, and an upper fixed plate 10 and a lower fixed plate 11 in which the lateral displacement amplifying lever and the vertical displacement amplifying lever are clamped. The upper fixed plate and the lower fixed plate are both fixed L-shaped structures and are arranged parallel to the plane where the lateral displacement amplifying lever and the vertical displacement amplifying lever are located. The lateral displacement amplifying lever and the vertical displacement amplifying lever are both provided with a hollow guide groove 15 along the middle part of the axial direction. The axial direction refers to the length direction of the lateral displacement amplifying lever and the vertical displacement amplifying lever. The lateral limit pin 5 and the vertical limit pin 7 perpendicularly and fixedly connected to the upper fixed plate and the lower fixed plate are just It is better to pass through the hollow guide grooves of the lateral displacement amplification lever and the vertical displacement amplification lever respectively. The upper fixed plate and the lower fixed plate are also provided with corresponding lateral guide grooves 12 and vertical guide grooves 13. The lateral displacement measuring axis 6 passes through the lateral guide groove of the upper fixed plate, the hollow guide groove of the lateral displacement amplification lever and the lateral guide groove of the lower fixed plate in sequence. The vertical displacement measuring axis 9 passes through the vertical guide groove of the upper fixed plate, the hollow guide groove of the vertical displacement amplification lever and the vertical guide groove of the lower fixed plate in sequence. The upper end of the lateral displacement amplification lever is hinged on the inclined cable, and the lower end is hinged to one end of the vertical displacement amplification lever. The other end of the vertical displacement amplification lever is freely set; two laser displacement meters are provided on the upper fixed plate or the lower fixed plate, which are used to measure the linear movement distance of the lateral displacement measurement axis and the vertical displacement measurement axis respectively.

[0025] The lateral limit pin, vertical limit pin, lateral displacement amplification lever, and vertical displacement amplification lever constitute a displacement decoupling mechanism. The lateral displacement amplification lever and the vertical displacement amplification lever are connected by an articulated force transmission component to achieve synchronous amplification and mechanical decoupling of the lateral bridge displacement and the in-plane vertical displacement.

[0026] A cable clamp 2 is installed on the diagonal cable. One end of the lateral displacement amplification lever is rotatably connected to the cable clamp via a rotating pin 3, and the other end is connected to the vertical displacement amplification lever via an articulated force transmission assembly. If a pin is provided for articulated connection, hollow guide grooves for lateral and vertical limit pins are provided in the middle of each lateral and vertical displacement amplification lever to achieve rotational connection between the displacement amplification lever and the limit pin, forming a fulcrum. The limit pin does not affect the movement of the displacement amplification lever. The upper and lower fixing plates are both L-shaped to match the arrangement of the lateral and vertical displacement amplification levers. A plurality of limit pin holes are provided at corresponding positions on the upper ends of the fixing plates, arranged along the axial direction of the fixing plates, for receiving corresponding limit pins. A lateral guide groove for the fixing plates is provided at corresponding positions in the middle, arranged along the lateral direction of the fixing plates (left-right direction in the figure). A vertical guide groove for the fixing plates is provided at corresponding positions on the other lateral ends of the fixing plates, arranged along the axial direction of the fixing plates (up-down direction in the figure).

[0027] During measurement, the displacement amplification lever is located between the upper and lower fixed plates, which are pivotally connected by horizontal and vertical limit pins. The lateral displacement measurement axis passes through the upper fixed plate's horizontal guide slot, the vertical hollow guide slot of the lateral displacement amplification lever, and the lower fixed plate's horizontal guide slot, from top to bottom. The vertical displacement measurement axis passes through the upper fixed plate's vertical guide slot, the horizontal hollow guide slot of the vertical displacement amplification lever, and the lower fixed plate's vertical guide slot, from top to bottom.

[0028] When the stay cable undergoes dynamic displacement in any direction, the lateral displacement amplification lever will simultaneously generate vertical movement and rotate about the lateral stop pin. The lateral displacement measurement axis will undergo lateral displacement relative to the fixed plate, reflecting the lateral displacement component of the stay cable; the vertical displacement measurement axis will undergo vertical displacement relative to the fixed plate, reflecting the vertical displacement component of the stay cable. The vertical displacement amplification lever will simultaneously generate lateral movement and rotate about the vertical stop pin. A non-contact laser displacement meter integrated into the fixed plate enables real-time and accurate displacement measurement of the lateral and vertical displacement measurement axes. The measurement data is transmitted via a network cable to a wireless router, which then remotely uploads it to a cloud-based data collection system for storage, analysis, and display. Equipment such as the laser displacement meter can be powered by any power source, including solar panels. For example, a monocrystalline silicon solar panel can be installed on the side of the lower fixed plate, and a battery can be installed on the bottom surface of the lower fixed plate. Lead-acid batteries are a low-cost and stable option. The battery is used to power the laser displacement meter.

[0029] In another technical solution, a cable clamp is provided on the inclined cable, and a pair of cable clamp ear plates are provided on the cable clamp, which are rotatably connected to the upper end of the lateral displacement amplification lever through a rotating pin.

[0030] In another technical solution, both the upper and lower fixing plates are secured to a base plate 14 embedded in the top surface of the main beam. Multiple stiffening ribs are installed on either side of the lower fixing plate to enhance structural stability. The upper and lower fixing plates are fixedly connected to the base plate, which is in turn fixedly connected to the bridge deck. Two vertical stiffening ribs are installed on either side of the lower fixing plate to ensure structural stability during operation.

[0031] In another technical solution, a plurality of limit pin holes are provided on the upper fixed plate and the lower fixed plate corresponding to the positions of the horizontal limit pins and the vertical limit pins, which are used to selectively set the horizontal limit pin and the vertical limit pin in one of the limit pin holes, thereby realizing the optimal arrangement of the fulcrums of the horizontal displacement amplification lever and the vertical displacement amplification lever on demand.

[0032] The transverse limit pin is bolted to the lower fixing plate. The position of the transverse limit pin on the lower fixing plate is adjustable by varying the position of the transverse limit pin hole, thereby achieving optimal placement of the fulcrum of the transverse displacement amplification lever. The vertical limit pin is bolted to the lower fixing plate. The position of the vertical limit pin on the lower fixing plate is adjustable by varying the position of the vertical limit pin hole, thereby achieving optimal placement of the fulcrum of the vertical displacement amplification lever. The transverse and vertical limit pins (fulcrums) of the transverse and vertical displacement amplification levers are adjustable to accommodate the transverse and vertical displacement amplification requirements of different cable diameters.

[0033] In another technical solution, the lateral limit pin is arranged at the upper part of the lateral displacement amplification lever, the lateral displacement measuring axis is arranged at the lower part of the lateral displacement amplification lever, the vertical limit pin is arranged close to the lateral displacement amplification lever, and the vertical displacement measuring axis is arranged away from the lateral displacement amplification lever.

[0034] In another technical solution, the hollow guide groove of the vertical displacement amplification lever is arc-shaped, which assists in smoothly realizing the displacement amplification conversion.

[0035] The present invention also provides a method for measuring the multi-dimensional vibration displacement of a stay cable based on a composite lever mechanism. First, the multi-dimensional vibration displacement of the stay cable is amplified using a lateral displacement amplification lever and a vertical displacement amplification lever to obtain the amplification value. Second, a decoupling algorithm is used to combine the displacement amplification value to output the transverse and vertical displacement data within the normal plane of the stay cable. By setting different amplification ratios for the lateral and vertical displacement amplification levers and combining the decoupling algorithm of the displacement coupling mechanism, displacement data for the stay cable in two separate directions (transverse and vertical within the normal plane) is output.

[0036] like Figure 4 As shown, the working principle of the present invention is simplified as shown in the figure. Initially, the length AE of the lateral displacement amplifying lever is L, the distance OA from the lateral limit pin to the top of the lateral displacement amplifying lever is L0, the distance OB from the lateral limit pin to the lateral displacement measuring axis is L1, the distance CE from the vertical limit pin to the bottom of the lateral displacement amplifying lever is L2, and the distance CF from the vertical limit pin to the vertical displacement measuring axis is L3; after vibration, the angle of rotation of the lateral displacement amplifying lever along the lateral limit pin is The linear movement distances BD and FG of the measured lateral displacement measurement axis and vertical displacement measurement axis are t1 and t0 respectively. The actual displacement data of the bridge in the horizontal and vertical directions in the plane of the cable-stayed cable are Δ1 and Δ0 respectively. The relationship between the actual displacement data and the measured data can be obtained as shown in formulas (1), (2), and (3): According to the relationship in the figure, we can get: ; ; ; According to the triangle similarity principle: ; Right now ; again ; Combining the two formulas, we can get: (1) (2) (3).

[0037] It will be understood that the present invention is described by way of some embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and embodiments. They can be fully applied to various fields suitable for the present invention, and further modifications can be easily implemented by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A multi-dimensional vibration displacement measuring device for a stay cable based on a composite lever mechanism, characterized in that: The cam is an L-shaped structure that is fixed to the upper and lower fixing plates, and the cam is L-shaped and is parallel to the plane where the cam and the vertical displacement amplifying lever are located. The cam is L-shaped and is parallel to the plane where the cam and the vertical displacement amplifying lever are located. The cam is L-shaped and is parallel to the plane where the cam and the vertical displacement amplifying lever are located. The cam is L-shaped and is parallel to the plane where the cam and the vertical displacement amplifying lever are located. The cam and the vertical displacement amplifying lever are L-shaped and are L-shaped. The cam is L-shaped and is ... L-shaped The upper fixed plate and the lower fixed plate are also provided with corresponding transverse guide grooves and vertical guide grooves. The transverse displacement measuring axis passes through the transverse guide groove of the upper fixed plate, the hollow guide groove of the transverse displacement amplifying lever and the transverse guide groove of the lower fixed plate in sequence. The vertical displacement measuring axis passes through the vertical guide groove of the upper fixed plate, the hollow guide groove of the vertical displacement amplifying lever and the vertical guide groove of the lower fixed plate in sequence. The upper end of the transverse displacement amplifying lever is hinged on the inclined cable, and the lower end is hinged to one end of the vertical displacement amplifying lever. The other end of the vertical displacement amplifying lever is freely set; two laser displacement meters are provided on the upper fixed plate or the lower fixed plate, which are used to measure the linear movement distance of the transverse displacement measuring axis and the vertical displacement measuring axis respectively.

2. The device for measuring the multi-dimensional vibration displacement of a stayed cable based on a composite lever mechanism according to claim 1, characterized in that: The stay cable is provided with a cable clamp, and the cable clamp is provided with a pair of cable clamp ear plates, which are rotatably connected to the upper end of the lateral displacement amplification lever through a rotating pin shaft.

3. The device for measuring the multi-dimensional vibration displacement of a stayed cable based on a composite lever mechanism according to claim 1, wherein: The upper fixing plate and the lower fixing plate are both fixed by a bottom plate embedded in the top surface of the main beam, and a plurality of stiffening ribs are provided on both sides of the lower fixing plate to increase the structural stability.

4. The device for measuring the multi-dimensional vibration displacement of a stayed cable based on a composite lever mechanism according to claim 1, wherein: The upper and lower fixed plates are provided with a plurality of limit pin holes corresponding to the positions of the horizontal limit pins and the vertical limit pins, which are used to selectively set the horizontal limit pins and the vertical limit pins in one of the limit pin holes, thereby realizing the optimal arrangement of the fulcrums of the horizontal displacement amplification lever and the vertical displacement amplification lever as required.

5. The device for measuring multi-dimensional vibration displacement of a stayed cable based on a composite lever mechanism according to claim 1, wherein: The lateral limit pin is arranged at the upper part of the lateral displacement amplification lever, the lateral displacement measuring axis is arranged at the lower part of the lateral displacement amplification lever, the vertical limit pin is arranged close to the lateral displacement amplification lever, and the vertical displacement measuring axis is arranged away from the lateral displacement amplification lever.

6. The device for measuring the multi-dimensional vibration displacement of a stayed cable based on a composite lever mechanism according to claim 1, wherein: The hollow guide groove of the vertical displacement amplifying lever is arc-shaped.

7. The method for measuring multi-dimensional vibration displacement of a stay cable based on a composite lever mechanism according to any one of claims 1 to 6, characterized in that: First, the multi-dimensional vibration displacement of the cable-stayed cable is amplified by the lateral displacement amplification lever and the vertical displacement amplification lever, and the amplification value is obtained. Second, the decoupling algorithm is used to combine the displacement amplification value to output the transverse and vertical displacement data in the normal plane of the cable-stayed cable.

8. The method for measuring multi-dimensional vibration displacement of a stay cable based on a composite lever mechanism according to claim 7, wherein: The linear movement distances of the lateral displacement measurement axis and the vertical displacement measurement axis are obtained as t1 and t0 respectively. Initially, the length of the lateral displacement amplification lever is L, the distance from the lateral limit pin to the lateral displacement measurement axis is L1, the distance from the vertical limit pin to the bottom end of the lateral displacement amplification lever is L2, and the distance from the vertical limit pin to the vertical displacement measurement axis is L3. After the multi-dimensional vibration of the inclined cable, the angle of rotation of the lateral displacement amplification lever along the lateral limit pin is ; Then, through the decoupling algorithm, the output displacement data of the transverse bridge direction and the vertical bridge direction in the normal plane of the inclined cable are Δ1 and Δ0 respectively. The calculation formula is as follows: ； ； in, .

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