Contact network guide height adjusting method and system

Abstract

The invention provides a catenary height adjustment method and system, and relates to the technical field of catenary height adjustment, and the method comprises the steps: obtaining the on-site measurement data of the height of a conductor in the span of a catenary; establishing a statics model of the elastic chain type suspension based on a parabola unit hypothesis; calculating the dropper force of each dropper according to the measurement data and the stress balance principle of the parabola unit; the vertical displacement of each node of the carrier cable is solved through a moment balance equation, and then the space coordinates of the carrier cable are obtained; calculating the theoretical length of each dropper according to the coordinates of the carrier cable, the design height of the contact line and the dropper force; and comparing the theoretical length with the dropper length in a standard state to generate a dropper length adjustment strategy. The method provided by the invention not only can realize measurement bottleneck breakthrough, but also can be suitable for complex suspension conditions, and in addition, can also ensure the performability of an adjustment strategy, output a quantified dropper shortening amount and guide accurate construction.

Description

Technical Field

[0001] The present invention relates to the technical field of contact network height adjustment, and in particular to a contact network height adjustment method and system. Background Art

[0002] In electrified railway overhead contact systems, dropper length is a key parameter for controlling contact wire height. During construction, excessive conductor height caused by deviations in dropper length can degrade the current-collecting quality of the pantograph and catenary, and even lead to safety accidents. Existing adjustment methods in related technologies have the following problems: First, measurement flaws. Dropper string length is difficult to measure directly on-site. Existing pantograph-net testing equipment can only capture conductor height data, but cannot accurately reflect the actual dropper string dimensions.

[0003] Second, the theoretical model is limited. Among them, the load sharing method is based on the parabola assumption and is only applicable to ideal straight-chain suspensions with no slack and uniform load. It cannot handle the complex working conditions of elastic suspensions. The computational complexity of the torque balance method is too high and it relies on idealized models, which has low engineering practicality. The finite element method requires discretization of linear approximation nonlinear units, which has low computational efficiency and its accuracy is affected by mesh division. The pre-slack analytical method does not cover the mechanical analysis of elastic suspension systems and its scope of application is limited.

[0004] Third, there are difficulties in engineering practice. Currently, engineering practice generally relies on manual experience to make tentative adjustments, lacking theoretical support, resulting in low adjustment efficiency and high rework rate.

[0005] Therefore, it is urgent to develop a suspension string adjustment method based on field measurable data (conductor height) to break through measurement limitations and establish an accurate mechanical model suitable for elastic suspension. Summary of the Invention

[0006] In order to solve the technical problems in the related art, the present invention provides a contact network conductor height adjustment method and system.

[0007] In order to achieve the above object, the technical solution adopted by the present invention includes: According to a first aspect of the present invention, a method for adjusting the height of a contact network is provided, comprising the following steps: Step S1: obtaining on-site measurement data of the conductor height within the catenary span, including the coordinates of the positioning point, the coordinates of the elastic dropper string, and the coordinates of the ordinary dropper string; Step S2: establishing a static model of the elastic chain suspension based on the parabolic element assumption, wherein the load-bearing cables and the contact line are regarded as parabolic elements with uniform load distribution; Step S3: Calculating the suspension force of each suspension string based on the measurement data and the force balance principle of the parabola unit; Step S4: Solve the vertical displacement of each node of the Messenger cable by using the moment equilibrium equation to obtain the spatial coordinates of the Messenger cable; Step S5: Calculate the theoretical length of each suspension string according to the coordinates of the load-bearing cables, the design height of the contact line, and the suspension string force; Step S6: Compare the theoretical length with the length of the suspension string under the standard state to generate a suspension string length adjustment strategy.

[0008] Optionally, in step S3, the calculation of the suspension string force specifically includes: For elastic suspension strings, the suspension string force is calculated using the suspension point reaction formula based on the coordinates of the adjacent positioning points and the first suspension string point, the contact line tension, and the unit deadweight. For ordinary droppers, the dropper force is calculated through the force balance of the segmented parabola unit according to the coordinates of the two adjacent dropper points, the contact line tension and the unit weight.

[0009] Optionally, in step S4, solving the vertical displacement of each node of the catenary cable includes: The contact point between the elastic sling and the load-bearing cable is taken as the boundary node, and the vertical support force of the elastic sling is calculated by the moment balance equation of the elastic sling. Taking the suspension point and the boundary node as endpoints, the moment equilibrium equation of the load-bearing cable is: Where, is the support force of the suspension point, is the horizontal position of the i-th group of suspension strings, is the horizontal position of the positioning point, is the gravitational constant, 、 are the horizontal and vertical components of the elastic sling force, is the height difference of the elastic slings on both sides, is the hanging force of the kth group of hanging strings, is the horizontal position of the kth set of suspension strings, is the horizontal tension of the catenary; Iterative solution of the vertical displacement of each hanging string point .

[0010] Optionally, in step S6, generating the adjustment strategy further includes: According to the deviation between the designed height and the measured height of the contact wire, the section where the conductor height exceeds the standard range is identified, where the standard range is ±30mm; For the droppers associated with the out-of-gauge section, output adjustment suggestions for the shortening amount.

[0011] According to a second aspect of the present invention, a contact network height adjustment system is provided, which is applied to the contact network height adjustment method described in any technical solution of the first aspect of the present invention, and the system comprises: Data acquisition module, used to obtain coordinate measurement data of positioning points, elastic droppers and ordinary droppers within the span; A modeling and calculation module, configured to execute the method for adjusting the catenary height as described in any one of the technical solutions of the first aspect of the present invention, and calculate the theoretical length of the dropper string and the adjustment amount; Output module, generates visual contact network geometry diagram and dropper adjustment strategy table.

[0012] Optionally, the modeling and calculation module is further configured to: Verify the calculation accuracy of the node coordinates and dropper length of the catenary through finite element simulation; When the error between the simulation value and the calculated value exceeds the threshold, the mechanical model parameters are automatically corrected.

[0013] According to the third aspect of the present invention, a computer device is also provided, comprising a memory, a processor, and a computer program stored on the memory and runnable on the processor. When the processor executes the computer program, the steps of the contact network conduction height adjustment method described in any one of the technical solutions in the first aspect of the present invention can be implemented.

[0014] According to the fourth aspect of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, it can implement the steps of the contact network conductance adjustment method described in any technical solution in the first aspect of the present invention.

[0015] Beneficial effects: 1. Through the above technical solution, the method of the present invention can firstly overcome the measurement bottleneck. With this method, there is no need to directly measure the dropper length; adjustment can be completed with only the conductor height data. Specifically, the method of the present invention uses the conductor height as the boundary condition of the mechanical model and indirectly derives the dropper length through inverse calculation, thus circumventing the physical limitation of being unable to measure the dropper on site.

[0016] Second, the method of the present invention is applicable to complex suspension situations, accurately reproducing the static geometric distribution of elastic chain suspensions. Specifically, the method of the present invention employs the parabolic element assumption (uniform load distribution and equal horizontal tension), discretizing the catenary / contact line into piecewise parabolas. It also introduces the moment balance equations at the nodes of the elastic dropper string, addressing the inability of traditional methods to account for the coupled forces between the elastic dropper string and the catenary cable.

[0017] Third, the proposed method ensures the feasibility of adjustment strategies, outputs quantified dropper shortening, and guides precise construction. Specifically, by comparing theoretical lengths with standard lengths, the associated dropper strings in the overrunning section are identified, and length deviations are calculated based on iterative results of catenary cable displacement.

[0018] In general, the method of the present invention drives the inversion model of unmeasurable parameters (suspender string length) through measurable data (conductor height), and breaks through the theoretical bottleneck by combining the elastic boundary moment equation.

[0019] 2. Other beneficial effects or advantages of the present invention will be described in detail in conjunction with the specific structure in the specific implementation manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive labor. In addition, it should be understood that the proportional relationship of the various components in the drawings of this specification does not represent the proportional relationship in the actual material selection and design. It is only a schematic diagram of the structure or position, among which: Figure 1 This is a schematic flow chart of the steps of a method for adjusting the height of a contact network provided by an exemplary embodiment of the present invention; Figure 2 is a schematic diagram of a suspension string adjustment process provided by an exemplary embodiment of the present invention; Figure 3 is a clue coordinate schematic diagram provided by an exemplary embodiment of the present invention; Figure 4 is a schematic diagram of point coordinates provided by an exemplary embodiment of the present invention; Figure 5 is a schematic diagram of local forces on an elastic suspension string provided by an exemplary embodiment of the present invention; Figure 6 is a schematic diagram of a load analysis of a Messenger cable provided by an exemplary embodiment of the present invention; Figure 7 is a schematic diagram of force analysis of an elastic sling node provided by an exemplary embodiment of the present invention; Figure 8 This is a schematic diagram of the geometric parameter analysis of a positioner provided by an exemplary embodiment of the present invention. Figure 9 It is a schematic diagram of a sub-force analysis of a curved segment contact suspension provided by an exemplary embodiment of the present invention; Figure 10is a schematic diagram of contact suspension spatial position coordinates provided by an exemplary embodiment of the present invention; Figure 11 is a schematic diagram of a contact suspension calculation shape provided by an exemplary embodiment of the present invention; Figure 12 1 is a schematic diagram comparing a measured height guide curve and a calculated height guide curve provided by an exemplary embodiment of the present invention; Figure 13 It is a schematic diagram of the adjustment amount of the suspension string provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0023] In order to facilitate relevant technical personnel to have a clearer and more accurate understanding of the technical solution of the present invention, the existing related technologies are described in more detail below.

[0024] In the overhead catenary system, droppers play a key role in mechanically and electrically connecting the catenary cables to the contact wires. Pre-setting the dropper length also helps control the height of the contact wires. Errors during installation can lead to dropper lengths that don't meet requirements. Consequently, the static geometry of the overhead catenary deviates from the standard shape, and the conductor height doesn't meet regulatory requirements. Therefore, any dropper strings that don't meet dimensional requirements should be adjusted to the appropriate length upon discovery.

[0025] Limited by current measurement methods, the length of the suspension string is difficult to accurately measure in engineering practice, and there is no basis for adjusting the suspension string. Therefore, when the suspension string length cannot be measured, it is necessary to develop a complete suspension string adjustment method based on existing measurement data.

[0026] Adjusting the dropper strings of elastically suspended catenary systems is a crucial step in catenary construction. Currently, this work is primarily conducted through trial and error, relying on the experience of on-site staff. This empirical approach lacks theoretical support and is inefficient. This paper proposes a dropper string adjustment strategy based on measurement data and cable net form-finding. The core of this approach is calculating the dropper string length by calculating the static shape of the catenary.

[0027] For calculating the static shape of the contact line, Yu Wanju, J. Benet, and other authors proposed a load-sharing method based on the parabola hypothesis. This method is computationally simple but only applies to the ideal case of a straight-chain suspension with no sag and uniform load distribution. Chang Yuechao and other authors proposed a torque method based on moment balance. This method is computationally intensive and only applicable to ideal models. Fang Yan, Liu Dayong, and other authors proposed a finite element method for cable net form-finding. This method considers the contact line as a nonlinear element and approximates the nonlinear element by wirelessly splitting the linear element to improve the calculation accuracy. Guan Jinfa and other authors proposed an analytical method for the static shape of pre-sag contact lines based on parabola elements. They provided a method for calculating contact line sag but did not analyze contact lines with elastic suspension.

[0028] This paper proposes a static analysis method for elastic chain suspensions, using parabolas as basic units and classical mechanics as the basis for calculations. Based on this method, a complete suspension string adjustment process is proposed and verified through field measurements and simulations.

[0029] The technical solution of the present invention is described in detail below with reference to the accompanying drawings.

[0030] like Figures 1 to 13 According to a first aspect of the present invention, a method for adjusting the height of a contact network is provided, comprising the following steps: Step S1: obtaining on-site measurement data of the conductor height within the catenary span, including the coordinates of the positioning point, the coordinates of the elastic dropper string, and the coordinates of the ordinary dropper string; Step S2: establishing a static model of the elastic chain suspension based on the parabolic element assumption, wherein the load-bearing cables and the contact line are regarded as parabolic elements with uniform load distribution; Step S3: Calculate the hanging force of each hanging string based on the measurement data and the force balance principle of the parabola unit; Step S4: Solve the vertical displacement of each node of the Messenger cable by using the moment equilibrium equation to obtain the spatial coordinates of the Messenger cable; Step S5: Calculate the theoretical length of each suspension string according to the coordinates of the load-bearing cables, the design height of the contact line, and the suspension string force; Step S6: Compare the theoretical length with the length of the suspension string under the standard state to generate a suspension string length adjustment strategy.

[0031] Through the above technical solution, the method of the present invention can firstly break through the measurement bottleneck. With this method, there is no need to directly measure the dropper length; adjustment can be completed with only the conductor height data. Specifically, the method of the present invention uses the conductor height as the boundary condition of the mechanical model and indirectly derives the dropper length through inverse calculation, thus circumventing the physical limitation of being unable to measure the dropper on site.

[0032] Second, the method of the present invention is applicable to complex suspension situations, accurately reproducing the static geometric distribution of elastic chain suspensions. Specifically, the method of the present invention employs the parabolic element assumption (uniform load distribution and equal horizontal tension), discretizing the catenary / contact line into piecewise parabolas. It also introduces the moment balance equations at the nodes of the elastic dropper string, addressing the inability of traditional methods to account for the coupled forces between the elastic dropper string and the catenary cable.

[0033] Third, the proposed method ensures the feasibility of adjustment strategies, outputs quantified dropper shortening, and guides precise construction. Specifically, by comparing theoretical lengths with standard lengths, the associated dropper strings in the overrunning section are identified, and length deviations are calculated based on iterative results of catenary cable displacement.

[0034] In general, the method of the present invention drives the inversion model of unmeasurable parameters (suspender string length) through measurable data (conductor height), and breaks through the theoretical bottleneck by combining the elastic boundary moment equation.

[0035] The method of the present invention is described below with reference to an exemplary embodiment.

[0036] 1. String adjustment process At present, based on the existing catenary detection equipment, it is difficult to directly detect the length of the catenary. The present invention proposes a method for adjusting the catenary height without the need for detecting the length of the catenary. The specific process can be found in Figure 2 shown.

[0037] The key and most difficult part of the catenary adjustment process is calculating the static geometry of the catenary. This paper proposes a static analytical method for elastic chain suspension using parabolas as basic units and classical mechanics as the calculation basis.

[0038] 2. Catenary Reconstruction Algorithm Based on Measurement Parameters The present invention regards the elastic chain type suspension contact network as a suspension cable structure, and all calculations are based on parabolic units with uniform load distribution.

[0039] This unit meets the following three prerequisites: 1. The horizontal tension of the clues is equal.

[0040] 2. The deadweight load of cables suspended at different heights is evenly distributed along the cable line.

[0041] 3. The clue is parabolic in shape on the vertical plane.

[0042] The catenary model based on parabola elements has high accuracy in the form-finding of simple chain-type suspended cable nets. According to the derivation and reasonable simplification of the classical force balance and moment balance formulas of the cable, for example Figure 3 As shown, in a coordinate system containing two points A and B and perpendicular to the horizontal plane, the two hanging points A ( , ) and B( , ),tension , the clue of unit weight g, satisfies the following two basic formulas: 1. In Figure 3 The coordinates of any point C on it ( , ) satisfies the functional relationship in the following formula 1.

[0043] (in, ) Formula 1 2. The support force of hanging points A and B on the clue 、 The values ​​along the positive direction of the y-axis satisfy the functional relationship in the following formula 2.

[0044] Formula 2 When the height difference between points A and B is too large, point B will no longer provide support, and the rope's gravity is completely supported by point A. .

[0045] Based on the above two basic formulas (Equation 1 and Equation 2), we first establish a mechanical model of the elastic chain suspension. The coordinates that need to be measured are: 1. Coordinates of N inelastic suspension strings: ( , )、( , ),……、( , ); 2. Coordinates of two elastic suspension strings: ( , ), ( , ); 3. Coordinates of two positioning points, ( , ), ( , ).

[0046] like Figure 4As shown, the positioning point O, the elastic sling and the elastic chord intersect at points B and D. The elastic sling intersects the load-bearing cable at point C. For the elastic chord BA, the chord force at point A comes from the gravity of the contact segments OA and AE at point A. Refer to the calculation formula for the reaction force of the unequal height suspended parabola unit at the suspension point. The chord force of the elastic chord can be obtained as : Formula 3 Where g is the unit length of the contact line (N / m), is the tension of the contact line (N).

[0047] Similarly, the hanging force of the nth hanging string can be obtained : Formula 4 Where, The value range is .

[0048] See also Figure 5 , according to the intersection of the elastic sling and the elastic chord The moment on the right is zero. Find the vertical support force of the load-bearing cable on the elastic sling at point B. : in 、 are the horizontal distances from the first hanging string on the right and left sides to point B; D is the distance between the two hanging points. 、 is the pulling force of the first suspension string on the right and left sides, For the weight of the hanging string, It is the deadweight of the cable per unit length.

[0049] According to the moment on the right side of the intersection point A of the elastic sling and the first chord on the right side is zero, solve the height difference between points A and B : in is the weight per unit length of the elastic sling, It is the lateral pulling force of the load-bearing cable on the elastic sling, which can be approximately equal to the tension of the elastic sling.

[0050] The angle between the elastic sling and the horizontal plane is .

[0051] For the load-bearing cable, make a force analysis diagram as follows Figure 6 shown.

[0052] According to the force analysis diagram ( Figure 6) It can be seen that the load-bearing cable is supported by the vertical force at the hanging points a and b. and , horizontal tension , at points C and C2, the elastic slings exert tension. and the weight of the elastic sling, the tension of the sling at the nth sling , Equal to the string force and the weight of the hanging string The sum, that is, .

[0053] The tension of segment CB on the catenary cable (i.e. tension ) is decomposed in the horizontal and vertical directions, respectively. and , plus the weight of the elastic sling, we can get the force on the load-bearing cable at point C Formula 7 Where, ——unit deadweight of elastic sling (N / m); - length of elastic sling (m); Since point C and The magnitude of the horizontal force generated by point A and the length of the force arm for points A and B are approximately equal, and the directions of the forces are opposite, so when calculating the moment at point A, the two are considered to cancel each other out. Assume that all the suspension strings are in a vertical state, that is, , the moment at point a is: Formula 8 Where g is the deadweight of the cable per unit length (N / m); is the horizontal position of the hanging point of the i-th hanging string. L is the span and .

[0054] The suspension point a does not rotate, so , that is, the support force of the suspension point b is: Formula 9 Similarly, the support force of the hanging point a can be obtained as: Formula 10 Since the moment at the node of the parabola unit is 0 in static equilibrium, the cable between the suspension point a and the contact point C between the elastic sling and the cable is considered as a parabola unit. The moment at the node C of the elastic sling is calculated. The force at point C is as follows: Figure 7 shown.

[0055] Formula 10 exist Figure 7 Among them is the tension of the catenary at the suspension point; is the load-bearing cable tension; Since the angle between the catenary and the elastic sling is very small at point C, it can be approximately considered that the tension of the catenary at the hanging point is equal to the difference between the tension of the catenary and the tension of the elastic sling. .

[0056] Therefore, the vertical displacement of point C from point a is: Formula 11 The height of the basic hanging structure is H. Therefore, the vertical coordinate of point C is , we can find the coordinates of point B, 、 The coordinates can be obtained in the same way.

[0057] Consider the load-bearing cable between the suspension point a and the first dropper string as a parabolic element and calculate the moment at the dropper string node 1: Formula 13 The vertical displacement of the dropper node 1 from point a is: Formula 14 Then we can find the vertical coordinate of the first hanging string .

[0058] Considering a more general case, the load-bearing cable between the suspension point a and the i-th dropper string is regarded as a parabolic unit, and the moment at the dropper string node i is calculated as follows: The vertical displacement of the dropper node i from point a is obtained as: Formula 15 Therefore, the vertical coordinate of the nth suspension string can be obtained .

[0059] At this point, the coordinates of each node distance point of the load-bearing cable have been calculated. The length of the elastic suspension string on both sides of a and b can be calculated. 、 , the length of the i-th suspension string Formula 16 Combined with the measured coordinates, the coordinates of all nodes of the basic suspension within a span have been calculated. According to formula 1 and the parameters of the line tension and line weight, the position of any point in the line can be accurately solved, and the exact length of the line can be calculated through integral calculation.

[0060] The method of the present invention can be used for contact network line length pre-matching, overall dropper string pre-matching, dropper string length adjustment, contact network stress analysis and other aspects, and has great engineering application value.

[0061] 3. Catenary form-finding algorithm based on dropper length See also Figure 8 , the contact wire is fixed on the positioner, and the positioner is connected to the positioner support, and the two are connected by a hook ring, such as Figure 8 As shown, the intersection of the two is equivalent to the rotation axis, and the positioner rotates around it. The angle of the positioner is related to the horizontal and vertical pulling forces of the contact line and the length and weight of the positioner. According to the moment balance formula, we have: In this formula, is the length of the positioner, is the locator angle, is the positioner weight, 、 are the lateral and longitudinal components of the pulling force of the contact line on the locator, It can be calculated using the unequal height suspension formula in the second point above (contact network reconstruction algorithm based on measurement parameters). The lateral pulling force on the contact line of the positioner is a pair of force couples, which can be calculated based on Figure 9 The geometric and mechanical relationships in are calculated.

[0062] See also Figure 9 According to the mechanical relationship, the contact line is pulled by the contact lines on both sides at the positioning point. , and the pulling force of the locator , the three forces are in equilibrium, so we can get: Where, is the tension of the contact line, 、 are the angles between the vertical line of the center line of the line at the positioning point and the left and right contact lines, respectively. According to the geometric relationship, we have: Where, Pull out the value at the anchor point; 、 Pull out values ​​for the adjacent positioning points on the left and right sides respectively; 、 are the distances along the line between the positioning point and the adjacent positioning points on the left and right sides respectively; R is the curve radius of the line; when the positioning point is on the inside of the curve, the ± signs in the formula are When the positioning point is outside the curve, the ± sign is Number.

[0063] Therefore, the height of the positioning support can be solved: Where h is the height of the contact line positioning point.

[0064] See also Figure 10 , to calculate the contact line height under the premise of knowing the length of each suspension string, it is necessary to establish a set of equations based on the spatial constraint relationship. Figure 10 Assuming that there are m spans of contact suspension involved in the calculation, and n groups of suspension strings in each span, the following matrix can be established to solve: Formula 17 in Represents the height of the contact line at the nth hanger string in the mth span. is the height of the catenary at the mth positioning point, It is the height difference between the load-bearing cable at the positioning point and the suspension point. It is the height of the elastic sling between the load-bearing cable clamp and the first suspension string.

[0065] For the anchor points, there are: Formula 18 in Represents the contact line height of the positioning point at the mth pillar, Represents the height of the locator connection point at the same position, Represents the height difference between the two.

[0066] Formula 19 in is the longitudinal load at the anchor point at the i-th pillar, which can be calculated using the formula for unequal height suspension in the same way as the chord force.

[0067] Formulas 17-19 are used to establish The unknown number h dimensional system of equations, which has a unique solution. and Calculate according to Equation 6 and Equation 15.

[0068] 4. Testing and Simulation This study used the Beijing-Shanghai High-Speed ​​Railway as a measurement target, collecting static catenary height data from the Cangzhou West to Langfang section of the line. This section of the catenary utilizes an elastic chain suspension, with six droppers per span (two elastic and four standard). The specific design parameters are shown in Table 1.

[0069] Table 1 Design parameters of the overhead contact network of the Beijing-Shanghai High-Speed ​​Railway The method of the present invention substitutes the design parameters of the contact network section and the conductor height measurement parameters into the calculation model, and predicts the overall shape of the contact network and the length of each dropper string. Figure 11 The geometry of the four-span contact network with downlink pole numbers between 3016 and 3008 is shown. The length of any section of the contact network can be determined by measurement.

[0070] Will Figure 11 The shape of the contact line is extracted and amplified, and then compared with the measured contact line shape to obtain Figure 12 The results in .

[0071] pass Figure 12 The analysis shows that the measured shape of the contact line is basically consistent with the calculated shape of the model, indicating that the model has a high degree of accuracy in restoring the contact line shape. According to relevant regulations, the height of the contact line at the suspension point should meet the design requirements, and the allowable deviation in construction should not be greater than ±30mm. For elastic simple suspension, the height of the contact line at the two sling clamps of the same sling from the rail surface should meet the design requirements, and the mutual deviation should not be greater than ±20mm. Analysis of the measurement data shows that Figure 12 The conductor height near 70m is in the state of exceeding the limit, and the conductor height near 130m is close to exceeding the limit. The length of the surrounding droppers may need to be adjusted. Then, by comparing the calculated shape of the contact network section with the standard shape, the adjustment amount of each dropper is calculated, such as Figure 13 shown.

[0072] Therefore, the output dropper adjustment amount is shown in Table 2 below.

[0073] Table 2 Adjustment of suspension string V. Conclusion 1. This invention proposes a method for adjusting catenary dropper strings based on on-site conductor height measurement data. Using this data to perform cable net form-finding, the calculated dropper string length is obtained, solving the problem of difficulty in determining the dropper string length during on-site measurements.

[0074] 2. This invention establishes a static geometry model for elastic contact suspension. Given known catenary design parameters and conductor height measurement data, it restores the overall shape of the catenary on site and solves the spatial coordinates of key points on the catenary. This provides valuable guidance for the design and construction of catenary systems.

[0075] 3. By substituting contact wire height measurement data from the Lanzhou-Xinjiang Passenger Dedicated Line into the calculation model, the length of each dropper wire in the test section was determined, the adjustment amount for each dropper wire was determined, and an adjustment strategy was generated. Finite element simulation verified the rationality and accuracy of the proposed method.

[0076] 4. Although the method of the present invention only models elastic contact suspension, it can be understood that the method of the present invention is also applicable to flexible suspension modes such as simple chain suspension and multiple chain suspension.

[0077] In one embodiment of the present invention, in step S3 of the present invention, the calculation of the suspension string force may specifically include: For elastic suspension strings, the suspension string force is calculated using the suspension point reaction formula based on the coordinates of the adjacent positioning points and the first suspension string point, the contact line tension, and the unit deadweight. For ordinary droppers, the dropper force is calculated through the force balance of the segmented parabola unit according to the coordinates of the two adjacent dropper points, the contact line tension and the unit weight.

[0078] Thus, in this implementation, the load sources can be accurately distinguished by calculating the dropper force partitions. The elastic dropper (near the anchor point) and the ordinary dropper (mid-span) have different force mechanisms (see Figure 4 and Figure 5 ), partitioned calculations can effectively avoid "one-size-fits-all" errors. The suspension point reaction formula (Equation 3 above) is used for elastic droppers, while the segmented equilibrium formula (Equation 4 above) is used for ordinary droppers. This avoids the full-span iteration required by the traditional moment method.

[0079] In one embodiment of the present invention, in step S4 of the present invention, solving the vertical displacement of each node of the catenary may include: The contact point between the elastic sling and the load-bearing cable is taken as the boundary node, and the vertical support force of the elastic sling is calculated by the moment balance equation of the elastic sling. Taking the suspension point and the boundary node as endpoints, the moment equilibrium equation of the load-bearing cable is: Where, is the support force of the suspension point, is the horizontal position of the i-th group of suspension strings, is the horizontal position of the positioning point, is the gravitational constant, 、 are the horizontal and vertical components of the elastic sling force, is the height difference of the elastic slings on both sides, is the hanging force of the kth group of hanging strings, is the horizontal position of the kth set of suspension strings, is the horizontal tension of the catenary; Iterative solution of the vertical displacement of each hanging string point .

[0080] Thus, in this embodiment, the method of the present invention quantifies for the first time the coupling force of the elastic sling on the load-bearing cable ( 、 ) can eliminate the error of traditional models that treat the load-bearing cables as independent units.

[0081] In one embodiment of the present invention, in step S6 of the present invention, generating the adjustment strategy may further include: Based on the deviation between the designed height and the measured height of the contact wire, the section where the conductor height exceeds the limit or is close to exceeding the limit is identified; for the droppers associated with the exceeding limit section, the adjustment suggestion of the shortening amount is output.

[0082] In this way, the over-limit (for example, greater than ±30mm) and the adjacent over-limit section (±20mm-30mm) can be effectively identified, which can effectively improve the inspection efficiency compared to manual inspection.

[0083] According to a second aspect of the present invention, there is further provided a contact network height adjustment system, which is applied to the contact network height adjustment method according to any one of the technical solutions in the first aspect of the present invention, and the system comprises: Data acquisition module, used to obtain coordinate measurement data of positioning points, elastic droppers and ordinary droppers within the span; A modeling and calculation module, configured to execute the method for adjusting the catenary height according to any one of the technical solutions in the first aspect of the present invention, and calculate the theoretical length of the dropper string and the adjustment amount; Output module, generates visual contact network geometry diagram and dropper adjustment strategy table.

[0084] In one embodiment of the present invention, the modeling and calculation module of the present invention is further configured to: Verify the calculation accuracy of the node coordinates and dropper length of the catenary through finite element simulation; When the error between the simulation value and the calculated value exceeds the threshold, the mechanical model parameters are automatically corrected.

[0085] According to the third aspect of the present application, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, it can implement the steps of the contact network height adjustment method in any technical solution in the first aspect of the present application.

[0086] It is understood that in this embodiment, the memory may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as read-only memory, flash memory, hard disk, or solid-state drive; and the memory may also include a combination of the aforementioned types of memory. This application does not impose specific limitations on this.

[0087] Similarly, a processor may implement or execute the various exemplary logical steps described in conjunction with the disclosure of this application. The processor may be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. It may implement or execute the various exemplary logical steps described in conjunction with the disclosure of this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0088] According to the fourth aspect of the present application, a computer-readable storage medium is also provided, on which a computer program is stored, characterized in that when the computer program is executed by a processor, it can implement the steps of the contact network height adjustment method in any technical solution in the first aspect of the present application.

[0089] In this embodiment, the computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a register, a hard disk, an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof, or any other form of computer-readable storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an application-specific integrated circuit (ASIC). In the embodiments of the present application, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0090] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for adjusting the height of a contact network, characterized in that: The steps include: Step S1: obtaining on-site measurement data of the conductor height within the catenary span, including the coordinates of the positioning point, the coordinates of the elastic dropper string, and the coordinates of the ordinary dropper string; Step S2: establishing a static model of the elastic chain suspension based on the parabolic element assumption, wherein the load-bearing cables and the contact line are regarded as parabolic elements with uniform load distribution; Step S3: Calculating the suspension force of each suspension string based on the measurement data and the force balance principle of the parabola unit; Step S4: Solve the vertical displacement of each node of the Messenger cable by using the moment equilibrium equation to obtain the spatial coordinates of the Messenger cable; Step S5: Calculate the theoretical length of each suspension string according to the coordinates of the load-bearing cables, the design height of the contact line, and the suspension string force; Step S6: Compare the theoretical length with the length of the suspension string under the standard state to generate a suspension string length adjustment strategy.

2. The method for adjusting the contact network height according to claim 1, characterized in that: In step S3, the calculation of the suspension string force specifically includes: For elastic suspension strings, the suspension string force is calculated using the suspension point reaction formula based on the coordinates of the adjacent positioning points and the first suspension string point, the contact line tension, and the unit deadweight. For ordinary droppers, the dropper force is calculated through the force balance of the segmented parabola unit according to the coordinates of the two adjacent dropper points, the contact line tension and the unit weight.

3. The method for adjusting the contact network height according to claim 1, characterized in that: In step S4, the vertical displacement of each node of the catenary cable is obtained by: The contact point between the elastic sling and the load-bearing cable is taken as the boundary node, and the vertical support force of the elastic sling is calculated by the moment balance equation of the elastic sling. Taking the suspension point and the boundary node as endpoints, the moment equilibrium equation of the load-bearing cable is: Where, is the support force of the suspension point, is the horizontal position of the i-th group of suspension strings, is the horizontal position of the positioning point, is the gravitational constant, 、 are the horizontal and vertical components of the elastic sling force, is the height difference of the elastic slings on both sides, is the hanging force of the kth group of hanging strings, is the horizontal position of the kth set of suspension strings, is the horizontal tension of the catenary; Iterative solution of the vertical displacement of each hanging string point .

4. The method for adjusting the contact height of the contact network according to claim 1, characterized in that: In step S6, the generation of the adjustment strategy further includes: According to the deviation between the designed height and the measured height of the contact wire, the section where the conductor height exceeds the standard range is identified, where the standard range is ±30mm; For the droppers associated with the out-of-gauge section, output adjustment suggestions for the shortening amount.

5. A contact network height adjustment system, characterized in that: The method for adjusting the height of a contact network applied to any one of claims 1 to 4, wherein the system comprises: Data acquisition module, used to obtain coordinate measurement data of positioning points, elastic droppers and ordinary droppers within the span; A modeling and calculation module, configured to execute the contact network height adjustment method according to any one of claims 1 to 4, and calculate the theoretical length of the dropper string and the adjustment amount; Output module, generates visual contact network geometry diagram and dropper adjustment strategy table.

6. The method for adjusting the contact network height according to claim 5, characterized in that: The modeling and calculation module is further configured to: Verify the calculation accuracy of the node coordinates and dropper length of the catenary through finite element simulation; When the error between the simulation value and the calculated value exceeds the threshold, the mechanical model parameters are automatically corrected.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the contact network height adjustment method according to any one of claims 1 to 4 can be implemented.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the contact network height adjustment method according to any one of claims 1 to 4 can be implemented.

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