Device and method for identifying distributed dynamic load of water-lubricated bearings of large-length-ratio ship

Abstract

The application provides a large-length-ratio ship water-lubricated bearing distributed dynamic load identification device, which comprises a strain signal acquisition device, a key phase signal acquisition device, a signal adjustment device, a wireless telemetry device, a power supply module, a signal acquisition card and a data analysis device; the strain signal acquisition device comprises multiple groups of strain gauges connected in full-bridge mode, each group of strain gauges comprises multiple strain gauges arranged in a circumferential direction on the same section of a shaft segment, the remote monitoring module comprises a signal acquisition card and a data analyzer, the acquisition card inputs multiple-channel strain signals into the signal acquisition card through the wireless telemetry device for signal synchronization, and then the signals are transmitted to the data analyzer for solving of the distributed dynamic load of the tail bearing. The vertical dynamic bending moment is solved by using signals of multiple strain test sections, a mechanical model is constructed to solve the distributed dynamic load of the tail bearing, and the state of the water-lubricated tail bearing can be more accurately understood by technical personnel, so that problems such as abnormal noise and excessive wear of the bearing can be prevented.

Description

Technical Field

[0001] This invention belongs to the field of state perception of rotating machinery systems, and relates to a method and device for identifying distributed dynamic loads of water-lubricated bearings with large length-to-diameter ratio, especially applicable to the identification of distributed dynamic loads of stern bearings in ship propulsion shafting. Background Technology

[0002] The service condition of water-lubricated bearings in ships is a crucial factor affecting the power transmission efficiency of the entire propulsion shaft system. Water-lubricated bearings in ships are characterized by a large length-to-diameter ratio (2:1 to 4:1) and low viscosity lubricating medium, which naturally results in a lower load-bearing capacity compared to traditional oil-lubricated bearings. Under harsh environments of low speed and heavy load, the rotor system consisting of the stern bearing and journal is in a complex lubrication state. The lubrication sub-regions near the bearing ends are often in mixed lubrication, while the cantilevered end lubrication sub-region is more prone to wear and frictional vibration. However, due to the cantilever effect of the propeller, the journal is in a flexed state, with the ends sinking and the middle arching. Therefore, the lubrication sub-region in the middle of the stern bearing is often in a hydrodynamic lubrication state, demonstrating the zoning characteristic of the axial lubrication state of water-lubricated bearings with a large length-to-diameter ratio. The load-bearing capacity of the stern bearing lubrication sub-regions varies. Understanding their distributed load-bearing characteristics is an important means of reflecting the operating condition of water-lubricated bearings and has significant engineering application value for improving stern bearing condition perception and preventing stern bearing failures.

[0003] In terms of dynamic load identification methods for bearings, the main methods currently include frequency domain methods, time domain methods, and load inversion methods based on shaft strain. Time domain methods utilize structural modal parameters to establish an inverse time domain model and reconstruct the dynamic load based on the known dynamic response. However, they suffer from drawbacks such as high sensitivity to initial values, unavoidable error accumulation, and low computational efficiency. Frequency domain methods construct an inverse frequency response function model of the system in the frequency domain and then identify the input through the system output. Frequency domain identification methods include direct inversion of the frequency response function and modal coordinate transformation. Modal coordinate transformation requires known structural modal parameters. After identifying the load distribution characteristics in modal space, it is transformed to physical space. This method requires high accuracy in modal parameter identification and suffers from errors due to modal truncation. Direct inversion of the frequency response function is simple and widely used. However, this method suffers from problems such as improper selection of measurement points and test conditions, and matrix ill-conditioning, leading to ill-posed solutions. Furthermore, the testing procedures for time domain and frequency domain methods are complex, and the testing equipment is difficult to install in the limited space of a real ship's shafting system, making them impractical for engineering applications. Compared to the previous two methods, the load inversion method based on shaft strain has a simpler testing procedure, employs an indirect measurement method by attaching strain gauges to the shaft, requires less space for testing equipment, and is feasible for application on actual ships. However, existing load inversion methods based on shaft strain focus on solving the overall bearing capacity, and most models can only solve for bearing loads under quasi-static conditions. Methods for solving the distributed dynamic loads of water-lubricated bearings with large length-to-diameter ratios have not yet been reported. Summary of the Invention

[0004] This invention aims to solve the problem of distributed dynamic load identification of water-lubricated stern bearings in ships. It introduces shaft strain measurement technology based on wireless telemetry and adopts an indirect bearing load measurement method to avoid damage to the bearing structure. It constructs a mechanical model of multi-point supported water-lubricated bearings, improves the ability of technicians to perceive the state of water-lubricated stern bearings, and prevents problems such as abnormal noise and excessive wear of bearings. This invention is a distributed dynamic load identification device for water-lubricated bearings in ships with a large length-to-diameter ratio.

[0005] This invention is implemented as follows:

[0006] This invention provides a distributed dynamic load identification device for water-lubricated bearings in ships with large length-to-diameter ratios, comprising a strain signal acquisition device, a key phase signal acquisition device, a signal conditioning device, a wireless telemetry device, a power supply module, a signal acquisition card, and a data analysis device. The strain signal acquisition device includes multiple sets of strain gauges connected in a full-bridge configuration axially along a shaft segment near the test bearing. Each set of strain gauges includes multiple strain gauges circumferentially arranged on the same cross section of the shaft segment. The signal conditioning device performs digital-to-analog conversion and anti-aliasing filtering on the strain signals. The power supply module supplies power to the signal conditioning device and the wireless telemetry device. The remote monitoring module includes a signal acquisition card and a data analyzer. The key phase signal is electrically connected to the signal acquisition card. The acquisition card inputs multiple strain signals via the wireless telemetry device for signal synchronization before transmitting them to the data analyzer for solving the distributed dynamic load of the stern bearing.

[0007] In some alternative implementations, a fastening chuck is provided on the corresponding shaft segment where the strain gauge is attached. The fastening chuck has an upper and lower split structure and is provided with a strain gauge protection chamber, a signal line channel, a functional chamber and a power supply chamber. The functional chamber is provided with a signal conditioning device and a wireless transmission module. The strain gauge wires are connected to the signal conditioning device located in the functional chamber through the signal line channel.

[0008] In some alternative implementations, the strain gauges should be attached to the same horizontal line.

[0009] In some optional implementations, the bond phase signal acquisition device includes an eddy current sensor and an electroplated steel strip, wherein the electroplated steel strip is attached at the same horizontal line as the strain gauge, and the eddy current sensor is arranged at the same cross section as the electroplated steel strip.

[0010] In some alternative implementations, the power supply module is either a coil-type power supply or a battery-type power supply. The coil-type power supply module includes an electromagnetic induction coil and a power supply probe, which uses the principle of electromagnetic induction to power the wireless transmitting node and the signal conditioning device. The battery-type power supply module consists of a rechargeable battery compartment, which uses the internally stored power to power the wireless transmitting node and the signal conditioning device.

[0011] In some alternative implementations, the signal conditioning device includes a digital-to-analog conversion module and a filtering module, wherein the filtering module is capable of performing anti-aliasing filtering on the strain signal.

[0012] In some alternative implementations, the wireless telemetry device consists of a wireless transmitting module and a wireless receiving module, with the wireless transmitting module transmitting data to the wireless receiving module via a data coil.

[0013] In some alternative implementations, the dynamic load identification device is located at the bearing fixed section or at both the fixed section and the cantilever section.

[0014] A method for identifying distributed dynamic loads on water-lubricated bearings in ships with high length-to-diameter ratios, characterized by the following steps:

[0015] (1) Determine the number of equivalent bearing support points n required for analyzing the distributed dynamic load of the stern bearing. n is generally greater than 3. Select n strain measurement sections on the rotating shaft on one side of the fixed end of the stern bearing. Install the above-mentioned large length-to-diameter ratio ship water-lubricated bearing distributed dynamic load identification device at the selected strain test sections.

[0016] (2) After the shaft system is started, the strain signals of each section are transmitted to the data analyzer through the wireless telemetry device. Combined with the key phase signal, the strain gauge output signals ε corresponding to 0° and 180° during one rotation of the shaft are obtained. 0° and ε 180° Thus, the maximum vertical bending moment during one revolution of the shaft can be calculated:

[0017]

[0018] Among them, M i (t) represents the dynamic vertical bending moment of the shaft section, N·m; E is the elastic modulus of the shaft, Pa; J is the section modulus of the shaft, m. 3 ; i The section number is the strain test section number of the rotating shaft, and t is the time.

[0019] (3) Establish a mechanical model of the shaft system. Assume that the shaft is broken at the strain test section. Write the moment balance equations for the shaft segment from the cantilever end of the shaft system to the strain test section. There are a total of n strain test sections, and a total of n moment balance equations can be written:

[0020]

[0021] Wherein, the shear force at the strain test section is Q; the bending moment corresponding to the strain test section is M; the self-weight of the shaft section is considered as a uniformly distributed load q; the transmission components such as couplings are considered as concentrated loads T; the weight of the propeller is simplified to a concentrated load W; L i This represents the distance from different equivalent support points or concentrated loads of the bearing to the strain test section; i The distance from the uniformly distributed load on different shaft segments to the strain test section is denoted as R; the support reaction force at the equivalent support point of the tail bearing is denoted as R.

[0022] The unknown quantity is the support reaction force R at the n equivalent support points of the tail bearing. i Therefore, the number of unknowns is consistent with the number of equations, and a unique solution can be obtained. By inputting the dynamic shaft section bending moment formula in step (3) into the shaft system mechanical model, the dynamic bearing load distribution change can be obtained.

[0023] In some alternative implementations, the dynamic load identification device is located at the bearing fixed section or at both the fixed section and the cantilever section.

[0024] The beneficial effects of this invention are:

[0025] 1) The distributed dynamic load identification method for water-lubricated bearings provided by this invention breaks through the limitations of traditional frequency domain methods and time domain methods, which can only identify the overall load of the bearing. It adopts an indirect bearing load measurement method, uses signals from multiple strain test sections to calculate the vertical dynamic bending moment, and constructs a mechanical model to solve the distributed dynamic load of the tail bearing. This not only helps technicians to have a more accurate understanding of the state of the water-lubricated tail bearing and prevents problems such as abnormal noise and excessive wear, but also avoids damage to the bearing structure and improves the service life of the device because the entire identification device is not located inside the bearing.

[0026] 2) The distributed dynamic load identification method for water-lubricated bearings provided by this invention has the characteristics of simple modeling and fast calculation speed. By inputting the dimensions and weight parameters of the shaft segment and the dynamic bending moment of multiple sections, the distributed load inside the tail bearing can be quickly solved, so as to achieve the purpose of real-time monitoring of the distributed load of the tail bearing.

[0027] 3) The water-lubricated bearing distributed dynamic load identification device provided by the present invention has the advantages of convenient installation, no impact on bearing structure and no need to disassemble bearing housing. It can be tested not only in laboratory environment, but also in actual ship propulsion shafting. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a simplified system diagram of the tail bearing distributed dynamic load identification device provided in an embodiment of the present invention.

[0030] Figure 2 This is a cross-sectional view of the fastening chuck provided in an embodiment of the present invention.

[0031] Figure 3(a) shows the arrangement of the distributed dynamic load identification device for the real ship coil stern bearing provided in Embodiment 1 of the present invention.

[0032] Figure 3(b) shows the arrangement scheme of the distributed dynamic load identification device for the battery-type stern bearing of a real ship provided in Embodiment 2 of the present invention.

[0033] Figure 4 A simplified mechanical model diagram of the stern shaft of a real ship provided in an embodiment of the present invention.

[0034] Figure 5 The arrangement scheme of the bench-mounted radial bearing distributed dynamic load identification device provided in the embodiment of the present invention is as follows.

[0035] Figure 6 A simplified mechanical model diagram of the shaft segment of the bench scaled-down bearing provided in an embodiment of the present invention.

[0036] The components include: 1. Strain gauge protection chamber; 2. Signal line channel; 3. Functional module chamber; 4. Power supply chamber; 5. Cover; 6. Fastening chuck; 7. Pre-processing module; 8. Wireless transmitter; 9. Coil-type power supply module; 10. Full-bridge strain gauge; 11. Power supply coil; 12. Data coil; 13. Wireless receiver; 14. Power supply probe; 15. Electroplated steel strip; 16. Eddy current sensor; 17. Test bearing; 18. Bearing housing; 19. Signal acquisition card; 20. Data analyzer; 21. Battery-powered power supply module. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0039] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0040] Example 1

[0041] Reference Figure 1 As shown, the distributed dynamic load identification device for large length-to-diameter ratio ship water-lubricated bearings provided in this embodiment can be divided into a field testing module and a remote monitoring module. The field testing module includes a strain measurement device, a key phase signal acquisition device, a signal conditioning device, a power supply module, and a wireless telemetry device. The strain signal acquisition device includes multiple sets of strain gauges connected in a full-bridge manner arranged axially along the shaft segment near the test bearing. Each set of strain gauges includes multiple strain gauges arranged circumferentially on the same cross section of the shaft segment. The signal conditioning device performs digital-to-analog conversion and anti-aliasing filtering on the strain signal. The power supply module supplies power to the signal conditioning device and the wireless signal transmitter. The remote monitoring module includes a signal acquisition card and a data analyzer. The key phase signal is electrically connected to the signal acquisition card. The acquisition card inputs multiple strain signals through the wireless telemetry device for signal synchronization and then transmits them to the data analyzer for solving the distributed dynamic load of the stern bearing.

[0042] In this embodiment, a fastening chuck is provided on the corresponding shaft segment where the strain gauge is bonded. Referring to Figure 3(a), the fastening chuck contains a strain gauge protection chamber 1, a signal line channel 2, a functional chamber 3, and a power supply chamber 4. The functional chamber contains a signal conditioning device and a wireless telemetry device. The strain gauge's wires are connected to the signal conditioning device in the functional chamber 3 through the signal line channel 2. The pressure cover 5 is fixed to the chuck with bolts for sealing the functional chamber 3 and the power supply chamber 5. The signal line channel is a groove set in the inner sidewall of the fastening chuck. The chuck has an upper and lower split structure and is fixed with bolts on the corresponding shaft segment where the strain gauge is bonded. This reduces the influence of the external environment on the strain gauge, improving its service life and testing accuracy; it also facilitates the installation and protection of the on-site data acquisition equipment.

[0043] Referring to Figure 3(a), which shows the arrangement scheme of the coil-type stern bearing distributed dynamic load identification device for actual ships provided in this application, assuming that the equivalent number of support points for analyzing the distributed load of bearing 17 is three, three sets of full-bridge connected strain gauges 10 are set on the fixed end shaft section on the left side of bearing 17. Each set of strain gauges includes multiple strain gauges circumferentially arranged on the same cross section of the shaft section. The fastening chuck 6 is installed on the shaft section corresponding to the three sets of strain test sections. The signal conditioning device 7 and the wireless telemetry device 8 are installed in the functional compartment 3 of the fastening chuck 6, and the coil-type power supply module 9 is installed in the power supply compartment 4. The wires of the full-bridge strain gauges 10 are connected to the signal conditioning device 7 in the fastening chuck 6 through the signal line channel 2. After the signal is filtered by anti-aliasing and converted from digital to analog, it is transmitted by the signal conditioning device 77 to the wireless transmission module 8. The wireless transmission module 8 transmits data to the wireless receiving device 13 through the data wires 12 wrapped around the fastening chuck 6. The wireless receiving device 13 transmits the dynamic strain signal to the remote monitoring module. The coil-type power supply module 9 supplies power to the wireless transmitter 8 and the preprocessing module 7 through the electromagnetic induction effect between the electromagnetic induction coil 11 wrapped around the fastening chuck 6 and the power supply probe 14. An electroplated steel strip 15 is attached to the shaft section on the left side of the fastening chuck, maintaining the same horizontal level as the strain gauge below the shaft section. The eddy current sensor probe 16 is positioned opposite the cross-section of the shaft section to which the electroplated steel strip 15 is attached. The key phase signal is connected to the signal acquisition card 19 in the remote monitoring module via a wire. The signal acquisition card 19 synchronizes the multi-section strain signal and the key phase signal and transmits them to the data analyzer 20 for calculation of the distributed dynamic load of the tail bearing.

[0044] Reference Figure 4 This embodiment also provides a method for identifying distributed dynamic loads on water-lubricated bearings of ships with large length-to-diameter ratios, including the following steps:

[0045] (1) Determine the number of equivalent bearing support points required for analyzing the distributed dynamic load of the tail bearing (3), select 3 strain measurement sections on the rotating shaft on one side of the fixed end of the tail bearing, and install the above-mentioned dynamic load identification device at the selected strain test sections.

[0046] (2) After the shaft system is started, the strain signals of the three test sections are transmitted to the data analyzer 20 through the signal acquisition card 19. Combined with the key phase signal, the strain gauge output signals ε corresponding to 0° and 180° during one rotation of the shaft are obtained. 0° and ε 180° Thus, the dynamic vertical maximum bending moment during one rotation of the shaft can be calculated:

[0047]

[0048] Among them, M i(t) represents the dynamic vertical bending moment of the shaft section, N·m; E is the elastic modulus of the shaft, Pa; J is the section modulus of the shaft, m. 3 ; i The section number is the strain test section number of the rotating shaft, and t is the time.

[0049] (3) Establish a mechanical model of the shaft segment corresponding to the cantilever end of the shaft system from the three strain test sections (S1, S2, S3). The shear force at the strain test section is Q, the bending moment corresponding to the strain test section is M, the self-weight of the shaft segment is considered as a uniformly distributed load q, the transmission components such as the coupling are considered as concentrated loads T, the weight of the propeller is simplified to a concentrated load W, and the support reaction force at the equivalent support point of the tail bearing is R, L. i This represents the distance from different equivalent support points or concentrated loads of the bearing to the strain test section; i The distance from the uniformly distributed load on different shaft segments to the strain test section.

[0050] Three moment balance equations are established for the three strain test sections (S1, S2, S3) to the cantilever end of the shaft:

[0051]

[0052]

[0053]

[0054] Convert it to matrix form as follows:

[0055]

[0056] 4) Solve for each set of bending moment data separately. The mechanical model composed of a single set of bending moment data contains three unknowns (R1, R2, R3) and three moment balance equations. The number of unknowns is the same as the number of moment balance equations, allowing for a unique solution. Therefore, solving for the continuous M1(t), M2(t), and M3(t) yields the dynamic tail bearing distributed loads R1(t), R2(t), and R3(t).

[0057] Example 2

[0058] Referring to Figure 3(b), this embodiment is basically the same as the first embodiment in structure, except that the power supply method is as follows: a battery power supply module 21 is used to power the wireless transmitting node 8 and the preprocessing module 7, eliminating the need for the electromagnetic induction coil 11 and the power supply probe 14. Its advantage is that it makes the structure of the dynamic load identification device simpler, but its disadvantage is that the battery power is limited and it cannot continuously identify distributed dynamic loads for a long time.

[0059] Example 3:

[0060] Reference Figure 5 As shown, this embodiment is applicable to the bench test of radial bearings with large length-to-diameter ratio. The difference from the first embodiment is as follows: First, the arrangement scheme of the distributed dynamic load identification device is as follows: Since there may be other supporting elements on the right side of the test bearing in the bench test, which cannot be regarded as the cantilever end, two strain test sections (S4 and S5) are arranged on the right side of the test bearing 17, and corresponding wireless telemetry devices are set up.

[0061] II. The mechanical model of the shaft segment is as follows: Moment balance equations are constructed by connecting strain test sections S1, S2, and S3 with strain test section S4. At this point, the shear force Q4 at strain test section S4 is introduced as a new unknown, making the number of unknowns greater than the number of equations. Therefore, compared to Example 1, a moment balance analysis is additionally performed on the shaft segment between strain test sections S4 and S5 to increase the number of moment balance equations and ensure the mechanical model has a unique solution. Please refer to the simplified diagram of the force analysis of the shaft segment. Figure 6 At this point, the mechanical model for identifying distributed dynamic loads on the bearing is:

[0062]

[0063] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for identifying distributed dynamic loads in water-lubricated bearings for ships with large length-to-diameter ratios, characterized in that: Includes the following steps: (1) Determine the number of equivalent bearing support points required for analyzing the distributed dynamic load of the tail bearing. n , n If the value is greater than 3, select a shaft on one side of the fixed end of the tail bearing. n A distributed dynamic load identification device for large aspect ratio ship water-lubricated bearings is installed at a selected strain measurement section. This device includes a strain signal acquisition device, a key phase signal acquisition device, a signal conditioning device, a wireless telemetry device, a power supply module, a signal acquisition card, and a data analysis device. The strain signal acquisition device includes multiple sets of fully bridged strain gauges axially arranged along the shaft segment near the test bearing. Each set of strain gauges includes multiple strain gauges circumferentially arranged on the same cross section of the shaft segment. The signal conditioning device performs digital-to-analog conversion and anti-aliasing filtering on the strain signal. The power supply module supplies power to the signal conditioning device and the wireless telemetry device. The remote monitoring module includes a signal acquisition card and a data analyzer. The key phase signal is electrically connected to the signal acquisition card. The acquisition card inputs multiple strain signals via the wireless telemetry device for signal synchronization before transmitting them to the data analyzer for solving the distributed dynamic load of the stern bearing. (2) After the shaft system is started, the strain signals of each section are transmitted to the data analyzer through the wireless telemetry device. Combined with the key phase signal, the strain gauge output signals corresponding to 0° and 180° during one rotation of the shaft are obtained. ε 0° and ε 180° Thus, the maximum vertical bending moment during one revolution of the shaft can be calculated: in, M i ( t The dynamic vertical bending moment of the shaft section is N·m. E The elastic modulus of the shaft is given in Pa. J The section modulus of the shaft is m. 3 ; i The section number is the strain test section number of the rotating shaft, and t is the time. (3) Establish a shaft system mechanical model. Assume that the shaft is broken at the strain test section. Write the moment balance equations for the shaft segment from the cantilever end of the shaft system to the strain test section. There are a total of n A total of strain test sections can be listed. n One torque balance equation: In this case, the self-weight of the shaft segment is considered as a uniformly distributed load. q The coupling transmission element is considered as a concentrated load. T The propeller's weight is a concentrated load. W ; L i This represents the distance from different equivalent support points or concentrated loads of the bearing to the strain test section; l i The distance from the uniformly distributed load on different shaft segments to the strain test section; the support reaction force at the equivalent support point of the tail bearing is R ;si is the i-th test section; The unknown quantity is the tail bearing. n Support reaction forces at each equivalent fulcrum R i Therefore, the number of unknowns is consistent with the number of equations, and a unique solution can be obtained. By inputting the dynamic shaft section bending moment formula in step (3) into the shaft system mechanical model, the dynamic bearing load distribution change can be obtained.

2. The method for identifying distributed dynamic loads in water-lubricated bearings for ships with large length-to-diameter ratios according to claim 1, characterized in that, The dynamic load identification device is installed in the bearing fixed section or separately in the fixed section and the cantilever section.

3. The method according to claim 1, characterized in that, A fastening chuck is provided on the corresponding shaft segment where the strain gauge is attached. The fastening chuck has an upper and lower split structure and is fastened by fasteners. It is equipped with a strain gauge protection chamber, a signal line channel, a functional chamber and a power supply chamber. The functional chamber is equipped with a signal conditioning device and a wireless transmission module. The strain gauge wires are connected to the signal conditioning device located in the functional chamber through the signal line channel.

4. The method according to claim 1 or 2, characterized in that, The strain gauges should be attached to the same horizontal line.

5. The method according to claim 1 or 2, characterized in that, The key phase signal acquisition device includes an eddy current sensor and an electroplated steel strip, wherein the electroplated steel strip is pasted at the same horizontal line as the strain gauge, and the eddy current sensor is arranged at the same cross section as the electroplated steel strip.

6. The method according to claim 1 or 2, characterized in that, The power supply module is one of coil power supply and battery power supply. The coil power supply module includes an electromagnetic induction coil and a power supply probe, which uses the principle of electromagnetic induction to power the wireless transmitting node and the signal conditioning device. The battery power supply module consists of a rechargeable battery compartment, which uses the internally stored power to power the wireless transmitting node and the signal conditioning device.

7. The method according to claim 1 or 2, characterized in that, The signal conditioning device includes a digital-to-analog conversion module and a filtering module, wherein the filtering module is capable of performing anti-aliasing filtering on the strain signal.

8. The method according to claim 1 or 2, characterized in that, The wireless telemetry device consists of a wireless transmitting module and a wireless receiving module. The wireless transmitting module transmits data to the wireless receiving module through a data coil.

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