Railway line longitudinal section optimization method and application thereof in tamping operation

Abstract

The application discloses a railway line longitudinal section optimization method and application thereof in tamping operation, and comprises the following steps: S101) acquiring the mileage of a measuring point on a railway line longitudinal section at a certain interval and corresponding elevation value data at the mileage; S102) according to the mileage of the measuring point and the corresponding elevation value data at the mileage, a maximum vector distance is iteratively found by using a dichotomy method to determine a slope change point; S103) judging whether the maximum vector distance is smaller than a maximum ramping amount, if yes, jumping to step S105) for execution, and if not, executing step S104); S104) judging whether the length of a slope section adjacent to the slope change point is smaller than a minimum slope section length, if yes, executing step S104), and if not, jumping to step S102) for execution; and S105) calculating the elevation value at the slope change point. The application can solve the technical problem that the existing longitudinal section optimization method has low precision, needs a large amount of manual intervention and cannot meet the efficient measurement demand.

Description

Technical Field

[0001] This application relates to the field of railway engineering technology, and in particular to a method for optimizing the longitudinal profile of railway lines based on the bisection iterative method and its application in tamping operations. Background Technology

[0002] With the increasing speed of passenger transport and the heavy-hauling of freight transport, railway transportation has entered a new era. However, this has also made railway lines more susceptible to deformation, placing greater pressure on railway operation and maintenance. Railway line deformation is divided into two types: horizontal curve deformation and longitudinal profile deformation. Currently, the technology for optimizing and correcting horizontal curve deformation is relatively mature, and the optimization results, when used in conjunction with tamping machines, have shown excellent effectiveness, leading to their widespread use across various railway bureaus. However, research on longitudinal profile optimization during railway overhauls started relatively late in my country, especially in the application of tamping machines during the overhaul and maintenance of existing lines, which is still in its initial stages. With the rapid growth of my country's railway mileage, the task of overhauling existing lines is becoming increasingly arduous, making further in-depth research in this area of ​​great practical significance.

[0003] The alignment of a railway line's longitudinal profile is determined by the gradient change points, and the mileage and elevation of these points are the basis for determining their spatial location. The optimization of the longitudinal profile in railway line engineering essentially involves finding the set of points with optimal gradient change locations in space. This requires improving the algorithm by incorporating constraints that satisfy the railway line's requirements and establishing a mathematical model. Domestic and international research on railway line longitudinal profile optimization design mainly employs analytical methods, enumeration methods, latitude reduction methods, cubic splines, least squares methods, augmented function methods, and genetic algorithms. Among these, the augmented function method is a commonly used algorithm with relatively good optimization results.

[0004] As attached Figure 1 As shown, the railway longitudinal profile consists of a series of gradient sections, specifically including a series of gradient change points P, straight sections L1, and vertical curve sections L2. Gradient change point P is the intersection of the extensions of two adjacent straight sections L1. Deformation of the railway longitudinal profile after long-term use can be categorized as follows: 1) changes in the mileage and elevation of gradient change points; 2) unevenness in straight sections; 3) changes in the radius and start / end points of vertical curves, etc. The main purpose of longitudinal profile optimization is to address the location and elevation of gradient change points. These two design tasks should meet the requirements of the "Railway Line Design Code" while minimizing engineering costs and other expenses.

[0005] Among the existing technologies, the following technical solutions are mainly related to this application: Prior art 1 is a Chinese invention application filed by China Railway Third Survey and Design Institute Group Co., Ltd. on April 12, 2012, and published on September 12, 2012, with publication number CN102663192A. This application discloses an automatic design and optimization method for railway longitudinal profiles. The method includes the following steps: smoothing the original ground line; fitting an initial slope to the smoothed ground line; processing the initial slope with longitudinal profile design constraints to form an automatic longitudinal profile slope design scheme; optimizing the longitudinal profile based on a differential evolution algorithm; setting optimization control parameters; initializing a population based on the automatic longitudinal profile slope design scheme; using an objective function as an evaluation of the merits of individual longitudinal profile schemes; calculating individual objective function values; and using mutation, crossover, repair, bridge / tunnel setting, and selection operations to evolve the population until the evolution termination condition is met, outputting a longitudinal profile diagram and a specification checklist. This method is characterized by high automation, strong practicality, and fast calculation speed, and has great application value in railway longitudinal profile design and optimization.

[0006] Prior art 2 is a Chinese invention application filed by North China University of Technology on September 14, 2015, and published on December 30, 2015, with publication number CN105205240A. This application discloses a method for automatic fitting, automatic optimization, and interactive design of subway longitudinal profiles. It uses relevant elevation constraints to automatically fit and optimize the subway longitudinal profile design, employing the least squares method for automatic slope fitting. This method can quickly and conveniently generate a relatively reasonable initial slope design scheme, providing rapid reference and guidance for longitudinal profile design and optimization. Based on the automatically fitted slope design, this application performs automatic longitudinal profile optimization to form a design scheme that meets the longitudinal profile slope design requirements. The application's use of relevant elevation constraints, automatic fitting, automatic design optimization, and automatic checking of specification requirements can improve the quality, efficiency, and compliance of longitudinal profile design.

[0007] Both of the above applications propose a longitudinal profile optimization method, but the technical solutions proposed in these two applications use the least squares and objective function methods. These two methods are not only low in accuracy, but also require a lot of manual intervention, which cannot meet the needs of efficient measurement. Summary of the Invention

[0008] In view of this, the purpose of this application is to provide a method for optimizing the longitudinal profile of railway lines and its application in tamping operations, so as to solve the technical problems that existing longitudinal profile optimization methods have low accuracy and require a lot of manual intervention, which cannot meet the needs of efficient measurement.

[0009] To achieve the aforementioned objectives, this application specifically provides a technical implementation scheme for a railway line longitudinal profile optimization method, which includes the following steps: S101) Obtain the mileage of the measurement points on the longitudinal profile of the railway line at certain intervals, and the corresponding elevation data at that mileage; S102) Based on the mileage of the measurement point and the corresponding elevation data at that mileage, the maximum vector distance is found iteratively using the bisection method to determine the slope change point; S103) Determine if the maximum vector distance is less than the maximum starting amount. If yes, proceed to step S105; otherwise, proceed to step S104. S104) Determine whether the length of the slope segment near the slope change point is less than the minimum slope segment length. If yes, proceed to step S105; otherwise, proceed to step S102. S105) Calculate the elevation value at the slope change point.

[0010] Furthermore, the starting point on the longitudinal profile of the railway line is the first marker point A, and the ending point is the second marker point B. The elevation between the first marker point A and the second marker point B is a solid curve. Step S102) further includes: Draw a chord between the first marker point A and the second marker point B. Find the point on curve AB with the largest distance from the chord AB, which is the point of change of slope C, and mark it as the third marker point. The distance from the point of change of slope to the corresponding chord is the maximum vector distance. Draw a chord between the first marker point A and the third marker point C. Find the point on the curve AC with the largest distance from the chord AC as the point of change of slope D, and denote it as the fourth marker point. Draw a chord between the second marker point B and the second marker point C. Find the point on curve BC with the largest distance from the chord BC and mark it as the point of change of slope E, which is the fifth marker point. Repeat the above steps to find all slope change points between adjacent marked points. Stop iterating when the distance from a point to the chord is less than the maximum constraint value of the starting amount or the slope length is less than the minimum constraint value. All slope change points have been found.

[0011] Furthermore, in step S104), the minimum slope length Calculate using the following formula:

[0012] in, For the first Mileage of each gradient change point For the first Mileage of each slope change point.

[0013] Furthermore, assuming there are on the longitudinal section of the railway line... Each slope section There are several slope change points, each at intervals of... There is one elevation measurement point, with a total of One elevation measurement point. In step S103), the maximum track lifting volume... Calculate using the following formula:

[0014] Among them, the The mileage of each gradient change point is The theoretical elevation value is , No. The mileage of each gradient change point is The theoretical elevation value is Current measurement point The measured elevation value at that location is , For the first From the first slope change point to the second The number of measurement points between the slope change points.

[0015] Furthermore, in step S105), if the slope difference between adjacent slope segments is greater than a set value, a vertical curve needs to be set, and the elevation value at the slope change point after setting the vertical curve is calculated.

[0016] Furthermore, in step S105), the elevation value at the slope change point... Calculate using the following formula:

[0017] in, This is the measured elevation value at the slope change point. Let be the radius of the vertical curve. , It is the angle formed between adjacent slope segments.

[0018] Furthermore, in step S105), after all the slope change points are found, when calculating the elevation value at the slope change point, if no vertical curve is set, the elevation value at the slope change point is the measured elevation value plus the minimum track lifting amount.

[0019] Furthermore, the maximum starting volume in step S103) The minimum slope length in step S104 is 0.03m. The value is 2‰, which is 200m. In step S105, the set value is 2‰.

[0020] This application also provides a technical implementation scheme for the application of the above-mentioned railway line longitudinal profile optimization method in tamping operations.

[0021] Furthermore, after calculating the elevation values ​​at all slope change points, a track ledger is generated. When the tamping machine needs to maintain the track section, the corresponding position of the railway line is raised to the calculated elevation value, that is, the railway line is restored to the theoretical alignment.

[0022] By implementing the railway line longitudinal profile optimization method provided in this application and its application in tamping operations, the following beneficial effects can be achieved: (1) The railway line longitudinal profile optimization method of this application and its application in tamping operation effectively improves the efficiency of railway line longitudinal profile optimization. It is not only simple to operate, but also greatly saves the manpower and time costs of data optimization, and can well meet the needs of efficient measurement. (2) The railway line longitudinal profile optimization method of this application and its application in tamping operation, the track lifting amount calculated by the bisection iteration method is much smaller than the track lifting amount calculated by the augmented function, the optimized longitudinal profile is closer to the actual measured value, and the workload of manual intervention in the later stage is greatly reduced. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structural composition of a railway longitudinal section; Figure 2 This is a schematic diagram illustrating the principle of gradient change point search in a specific embodiment of the railway line longitudinal profile optimization method of this application; Figure 3 This is a schematic diagram illustrating the principle of calculating the elevation of the slope change point in a specific embodiment of the railway line longitudinal profile optimization method of this application; Figure 4 This is a flowchart of a specific embodiment of the railway line longitudinal profile optimization method of this application; Figure 5 This is a schematic diagram comparing the results of the railway line longitudinal profile optimization method of this application with the currently commonly used augmented function method in the calculation of track lifting volume; Figure 6 This is a structural block diagram of a specific embodiment of a railway line longitudinal profile optimization device based on the method of this application; Figure 7 This is a schematic block diagram of a specific embodiment of the railway line longitudinal profile optimization device based on the method of this application, applied to a tamping machine. In the diagram: 1-Data acquisition module, 2-Slope change point search module, 3-Judgment module, 4-Elevation calculation module, 100-Railway line longitudinal profile optimization device, 200-Tamming machine, 300-Operating mechanism. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] As attached Figure 1 To be continued Figure 7 As shown, a specific embodiment of the railway line longitudinal profile optimization method of this application and its application in tamping operations is given. The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this application.

[0027] This application presents a method for optimizing the longitudinal profile (elevation) of railway lines based on the bisection iteration method. This method finds the location of the slope change point in the elevation data. Compared with the slope change point and the optimized track lifting volume calculated by the augmented function method currently used, the slope change point calculated by the elevation optimization algorithm based on the bisection iteration method in this application has a smaller track lifting volume, is closer to the actual measured value, and better meets the needs of practical application. At the same time, the operation is simpler and more efficient.

[0028] Example 1 As attached Figure 4 As shown, an embodiment of the railway line longitudinal profile optimization method of this application specifically includes the following steps: S101) Obtain the mileage of the measurement points on the longitudinal profile of the railway line at certain intervals, and the corresponding elevation data at each mileage; organize the measured elevation data into an Excel table, with one column for mileage and one column for elevation, and import it directly. S102) Based on the mileage of the measurement point and the corresponding elevation data at that mileage, the maximum vector distance is found using the bisection method iteratively to determine the slope change point (i.e., the point where the slope changes, as shown in the appendix). Figure 2 As shown in the diagram, points C, D, E, F, G, and H are all points where the slope changes. S103) Determine if the maximum vector distance is less than the maximum starting amount. If yes, proceed to step S105; otherwise, proceed to step S104. S104) Determine whether the length of the slope segment (a slope segment is a section of the line with the same gradient, as shown in the attached figure, AC is a slope segment and CB is a slope segment) adjacent to the slope change point is less than the minimum slope segment length. If yes, proceed to step S105; otherwise, jump to step S102. S105) Calculate the elevation value at the slope change point.

[0029] The railway line longitudinal profile optimization method described in Example 1 optimizes the longitudinal profile of existing lines during major overhauls. The method takes as input the elevation measurements of rail surface points spaced 10 meters apart, and outputs elevation data for use by tamping machines to correct the railway. The aim is to ensure that the overhauled railway meets all requirements of the "Railway Line Design Code" in its longitudinal profile. To achieve the above-mentioned objectives, this example sets two quantifiable constraints: First, there is a minimum constraint on the length of the slope segment, which means that the length of a slope segment between adjacent slope change points should generally be greater than the length of a train. In this embodiment, this value is set to 200m.

[0030] Secondly, there is a maximum constraint on track lifting volume. Since the elevation optimization data obtained in this application is mainly used in conjunction with track engineering vehicles (such as tamping machines), and the tamping machine has a maximum track lifting volume, this value is set to 0.03m in this embodiment.

[0031] As attached Figure 2 As shown, the starting point on the longitudinal profile of the railway line is the first marker point A, and the ending point is the second marker point B. The elevation between the first marker point A and the second marker point B is a solid curve. Step S102) further includes: Draw a chord between the first marker point A and the second marker point B. Find the point on the curve AB with the largest distance from the chord AB, which is the point of change of slope C, and mark it as the third marker point. The distance from the point of change of slope to the corresponding chord is the maximum vector distance. Draw a chord between the first marker point A and the third marker point C. Find the point on the curve AC with the largest distance from the chord AC, which is the point of change of slope D, and denote it as the fourth marker point. Draw a chord between the second marker point B and the second marker point C. Find the point on curve BC with the largest distance from the chord BC, which is the point of change of slope E, and mark it as the fifth marker point. Repeat the above steps to find all slope change points between adjacent marked points. Stop iterating when the distance from a point to the chord is less than the maximum constraint value of the starting amount or the slope length is less than the minimum constraint value. All slope change points have been found.

[0032] In step S104), the minimum slope length Calculate using the following formula:

[0033] in, For the first Mileage of each gradient change point For the first Mileage of each slope change point.

[0034] Assume there are on the longitudinal section of the railway line Each slope section There are several slope change points, each at intervals of... (e.g., 10 meters) There is one elevation measurement point, with a total of A 10-meter elevation measurement point. In step S103), the maximum track lifting volume... Calculate using the following formula:

[0035] Among them, the The mileage of each gradient change point is The theoretical elevation value is , No. The mileage of each gradient change point is The theoretical elevation value is Current measurement point The measured elevation value at that location is , For the first From the first slope change point to the second The number of measurement points between the slope change points.

[0036] In step S105), if the slope (algebraic) difference between adjacent slope segments (i.e., the slope difference between adjacent slope segments) is greater than a set value, a vertical curve needs to be set (because there will be inflection points at the intersection of two straight lines, resulting in unevenness of the line, therefore a vertical curve needs to be set, as shown in the attached figure). Figure 3 The arc between the included angles shown is the vertical curve, and the elevation value at the slope change point after setting the vertical curve is calculated.

[0037] As attached Figure 3 As shown, in step S105), the elevation value at the slope change point is... Calculate using the following formula:

[0038] in, This is the measured elevation value at the slope change point. Let be the radius of the vertical curve. , The included angle between adjacent slope segments is calculated using the algebraic difference in slope between the adjacent slope segments. .

[0039] In step S105), after all the slope change points are found, when calculating the elevation value at the slope change point, if no vertical curve is set, the elevation value at the slope change point is the measured elevation value plus the minimum track lifting amount.

[0040] As a typical embodiment of this application, the maximum starting amount in step S103) Specifically, it is set to 0.03m, the minimum slope length in step S104). Specifically, the value is set to 200m, and the setting value in step S105 is specifically set to 2‰.

[0041] After obtaining the elevation data using the method described in Example 1, it will be used as a track maintenance log. If maintenance is required on this section of track in the future, simply raise the track to the calculated elevation, which means that the section of track will be restored to the theoretical alignment.

[0042] As attached Figure 5 As shown, the commonly used augmented function method and the bisection iterative method used in this application's embodiments are compared and calculated. Specifically, the track lifting volume is calculated for the slope change points and elevations obtained by the two algorithms. (See attached...) Figure 5 Curve I in the figure represents the track lifting volume calculated using the augmented function method, while curve J represents the track lifting volume calculated using the bisection iterative method of this application. The data comparison in the figures shows that the track lifting volume calculated using the bisection iterative method of this application is significantly smaller than that calculated using the existing augmented function method. This fully demonstrates that the railway line longitudinal profile optimized using the bisection iterative method of this application is closer to the actual measured value, which greatly reduces the workload and difficulty of subsequent manual intervention.

[0043] Example 2 A specific embodiment of the application of the railway line longitudinal profile optimization method as described in Embodiment 1 of this application in tamping operations. After calculating the elevation values ​​at all slope change points, a track operation log is generated. When the tamping machine 200 needs to maintain the section of track, the corresponding position of the railway line is raised to the calculated elevation value, that is, the railway line is restored to the theoretical alignment.

[0044] Example 3 As attached Figure 6 As shown, an embodiment of a railway line longitudinal profile optimization device 100 based on the method described in Embodiment 1 of this application specifically includes: Data acquisition module 1 acquires the mileage of measurement points on the longitudinal profile of the railway line at certain intervals, as well as the corresponding elevation values ​​at those mileages; The slope change point search module 2 uses the mileage of the measurement point output by the data acquisition module 1 and the corresponding elevation value data at that mileage to find the maximum vector distance through the bisection method to determine the slope change point. Judgment module 3 determines whether the maximum vector distance obtained by slope change point search module 2 is less than the maximum starting amount, or whether the length of the slope segment adjacent to the slope change point is less than the minimum slope segment length. If not, slope change point search module 2 continues to search for and determine the slope change point. If so, the measured elevation value at the slope change point and the geometric parameters of the adjacent slope segment are output. Elevation calculation module 4 calculates the elevation value at the slope change point based on the measured elevation value at the slope change point, the geometric parameters of the adjacent slope section, and the minimum road lifting volume.

[0045] The starting point on the longitudinal profile of the railway line is marked as the first marker point A, and the ending point is marked as the second marker point B. The elevation between the first marker point A and the second marker point B is a solid curve. The gradient change point search module 2 constructs a chord between the first marker point A and the second marker point B, and finds the point on curve AB with the largest distance to chord AB, which is the gradient change point C, denoted as the third marker point. The distance from the gradient change point to the corresponding chord is the maximum moment. A chord is constructed between the first marker point A and the third marker point C, and finds the point on curve AC with the largest distance to chord AC, denoted as the gradient change point D, denoted as the fourth marker point. A chord is constructed between the second marker point B and the second marker point C, and finds the point on curve BC with the largest distance to chord BC, denoted as the fifth marker point. The process iterates repeatedly to find gradient change points between all adjacent marker points until the distance from the point to the chord is less than the maximum constraint value for track starting or the slope length is less than the minimum constraint value, at which point the iteration stops, and all gradient change points are found.

[0046] Module 3 further calculates the minimum slope length according to the following formula. :

[0047] in, For the first Mileage of each gradient change point For the first Mileage of each slope change point.

[0048] The longitudinal profile of the railway line has Each slope section There are several slope change points, each at intervals of... There is one elevation measurement point, with a total of One elevation measurement point. The judgment module 3 further calculates the maximum track lifting volume according to the following formula. :

[0049] Among them, the The mileage of each gradient change point is The theoretical elevation value is , No. The mileage of each gradient change point is The theoretical elevation value is Current measurement point The measured elevation value at that location is , For the first From the first slope change point to the second The number of measurement points between the slope change points.

[0050] Once all slope change points are found, when calculating the elevation value at the slope change points, if the elevation calculation module 4 determines that the slope difference between adjacent slope segments is greater than the set value, then a vertical curve is set, and the elevation value at the slope change point after setting the vertical curve is calculated.

[0051] Elevation calculation module 4 further calculates the elevation value at the slope change point after setting the vertical curve according to the following formula. :

[0052] in, This is the measured elevation value at the slope change point. Let be the radius of the vertical curve. , It is the angle formed between adjacent slope segments.

[0053] If no vertical curve is set, the elevation calculation module 4 calculates the elevation at the slope change point as the measured elevation value plus the minimum track lifting amount.

[0054] As a typical embodiment of this application, the maximum starting volume Specifically, the minimum slope length is set to 0.03m. Specifically, it is set to 200m, and the set value is specifically set to 2‰.

[0055] Example 4 As attached Figure 7 As shown, an embodiment of a tamping machine 200 specifically includes a railway line longitudinal profile optimization device 100 as described in Embodiment 3, mounted thereon. The tamping machine 200 also includes a working mechanism 300. After calculating the elevation values ​​at all gradient change points, the railway line longitudinal profile optimization device 100 generates track operation log data. When the tamping machine 200 needs to perform maintenance on a section of track, the working mechanism 300 raises the corresponding position of the railway line to the calculated elevation value, thus restoring the railway line to its theoretical alignment.

[0056] In the description of this application, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it may be directly or indirectly set on another element; when an element is referred to as being "connected to" another element, it may be directly or indirectly connected to another element.

[0057] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0059] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which this application can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this application can produce, should still fall within the scope of the technical content disclosed in this application.

[0060] By implementing the railway line longitudinal profile optimization method described in the specific embodiments of this application and its application in tamping operations, the following technical effects can be achieved: (1) The railway line longitudinal profile optimization method described in the specific embodiments of this application and its application in tamping operation effectively improves the efficiency of railway line longitudinal profile optimization. It is not only simple to operate, but also greatly saves the manpower and time costs of data optimization, and can well meet the needs of efficient measurement. (2) The railway line longitudinal profile optimization method described in the specific embodiments of this application and its application in tamping operation, the track lifting amount calculated by the bisection iteration method is much smaller than the track lifting amount calculated by the augmented function, the optimized longitudinal profile is closer to the actual measured value, and the workload of manual intervention in the later stage is greatly reduced.

[0061] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0062] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make many possible variations and modifications to the technical solutions of this application using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of this application. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall still fall within the protection scope of the technical solutions of this application.

Claims

1. A method for optimizing the longitudinal profile of a railway line, characterized in that, Includes the following steps: S101) Obtain the mileage of the measurement points on the longitudinal profile of the railway line at certain intervals, and the corresponding elevation data at that mileage; S102) Based on the mileage of the measurement point and the corresponding elevation data at that mileage, the maximum vector distance is found iteratively using the bisection method to determine the slope change point; S103) Determine if the maximum vector distance is less than the maximum starting amount. If yes, proceed to step S105; otherwise, proceed to step S104. S104) Determine whether the length of the slope segment near the slope change point is less than the minimum slope segment length. If yes, proceed to step S105; otherwise, proceed to step S102. S105) Calculate the elevation value at the slope change point; The starting point on the longitudinal profile of the railway line is the first marker point A, and the ending point is the second marker point B. The elevation between the first marker point A and the second marker point B is a solid curve. Step S102) further includes: Draw a chord between the first marker point A and the second marker point B. Find the point on curve AB with the largest distance from the chord AB, which is the point of change of slope C, and mark it as the third marker point. The distance from the point of change of slope to the corresponding chord is the maximum vector distance. Draw a chord between the first marker point A and the third marker point C. Find the point on the curve AC with the largest distance from the chord AC as the point of change of slope D, and denote it as the fourth marker point. Draw a chord between the second marker point B and the second marker point C. Find the point on curve BC with the largest distance from the chord BC and mark it as the point of change of slope E, which is the fifth marker point. Repeat the above steps to find all slope change points between adjacent marked points. Stop iterating when the distance from a point to the chord is less than the maximum constraint value of the starting amount or the slope length is less than the minimum constraint value. All slope change points have been found.

2. The method for optimizing the longitudinal profile of a railway line according to claim 1, characterized in that, The minimum slope length Calculate using the following formula: ； in, For the first Mileage of each gradient change point For the first Mileage of each slope change point.

3. The railway line longitudinal profile optimization method according to claim 1 or 2, characterized in that, Assume there are on the longitudinal section of the railway line Each slope section There are several slope change points, each at intervals of... There is one elevation measurement point, with a total of One elevation measurement point; in step S103), the maximum track lifting volume Calculate using the following formula: ； Among them, the The mileage of each gradient change point is The theoretical elevation value is , No. The mileage of each gradient change point is The theoretical elevation value is Current measurement point The measured elevation value at that location is , For the first From the first slope change point to the second The number of measurement points between the slope change points.

4. The railway line longitudinal profile optimization method according to claim 3, characterized in that: In step S105), if the slope difference between adjacent slope segments is greater than the set value, a vertical curve needs to be set, and the elevation value at the slope change point after setting the vertical curve is calculated.

5. The railway line longitudinal profile optimization method according to claim 4, characterized in that, In step S105), the elevation value at the slope change point Calculate using the following formula: ； in, This is the measured elevation value at the slope change point. Let be the radius of the vertical curve. , It is the angle formed between adjacent slope segments.

6. The railway line longitudinal profile optimization method according to claim 4 or 5, characterized in that: In step S105), after all the slope change points are found, when calculating the elevation value at the slope change point, if no vertical curve is set, the elevation value at the slope change point is the measured elevation value plus the minimum track lifting amount.

7. The method for optimizing the longitudinal profile of a railway line according to claim 6, characterized in that: The maximum starting volume in step S103) The minimum slope length in step S104 is 0.03m. The value is 2‰, which is 200m. In step S105, the set value is 2‰.

8. The application of a railway line longitudinal profile optimization method as described in any one of claims 1 to 7 in tamping operations.

9. The application of the railway line longitudinal profile optimization method according to claim 8 in tamping operations, characterized in that: After calculating the elevation values ​​at all slope change points, the line ledger data is generated. When the tamping machine (200) needs to maintain the section of the line, the corresponding position of the railway line is raised to the height of the calculated elevation value, that is, the railway line is restored to the theoretical alignment.

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