Method and system for selecting a rail grinding method

Abstract

To provide a selection method of a rail corrective grinding method for optimizing and improving the efficiency of rail corrective grinding work by a classification method of a rail cross-sectional shape which is hardly affected by the measurement accuracy of rail cross-sectional shape data and a method for selecting an optimum pattern among existing corrective grinding patterns by the classification method, and a selection system for the rail corrective grinding method.SOLUTION: A selection method of a rail corrective grinding method has: a contour shape measurement step of measuring at least a contour shape in a rail transverse cross-sectional direction; a design value acquisition step of acquiring a design value of the contour shape in the rail transverse cross-sectional direction; and a superposition step of superposing the contour shape measured in the contour shape measurement step and the design value; a design difference area calculation step of calculating a design difference area between the contour shape and the design value; and a corrective grinding pattern selection step of obtaining an evaluation index of the cross-sectional shape from the design difference area and selecting a corrective grinding pattern corresponding to the evaluation index.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rail grinding method selection method and a grinding method selection system that can select a rail grinding method that conforms to a rail cross-sectional shape obtained by a measuring device installed on a track inspection vehicle or on the ground. [Background technology]

[0002] Conventionally, railway operators periodically perform rail grinding work using rail grinding vehicles to remove rail fatigue layers from the viewpoint of preventing damage to the rails, and to remove rail corrugations and irregularities at rail welds from the viewpoint of reducing vibration and noise. Various means are known for such rail grinding work.

[0003] For example, the rail grinding work described in Patent Document 1 measures the contour of the top of the rail using a sensor installed on a rail grinding vehicle, and when setting the grinding amount based on the contour before grinding, takes into account the contour after grinding, automatically correcting the grinding pattern to accurately converge the final contour to the target one.

[0004] Furthermore, the rail grinding work described in Patent Document 2 acquires the cross-sectional shape of the rail using a measuring device mounted on a rail grinding vehicle, and automatically generates a grinding pattern for the grinding vehicle according to the cross-sectional shape of the rail.

[0005] Furthermore, the rail grinding work described in Patent Document 3 involves inputting data on the rail cross-sectional shape obtained by a measuring device mounted on a rail flaw detection vehicle into a computer, automatically generating a grinding pattern based on the input data, outputting a rail grinding instruction sheet, and performing the rail grinding work based on the instruction sheet.

[0006] Furthermore, the rail grinding work described in Patent Document 4 involves measuring the shape of the rail top surface over a certain section using a measuring device fixed at a fixed position on the ground, calculating from the measurement data the shape of the rail top surface after grinding, the grinding amount distribution required to achieve that rail top surface shape, and a grinding pattern and schedule that follow a regularity for achieving the grinding amount distribution, and then carrying out grinding work using a grinding vehicle in accordance with the schedule of the calculated grinding pattern.

[0007] Furthermore, the rail grinding work described in Patent Document 5 calculates the average size of rail unevenness for each fixed section from continuous data of rail unevenness measured on the ground or on board the vehicle, determines the sections for rail grinding, and classifies the amount of unevenness caused by corrugation, and thereby determines the number of passes for rail grinding for each section depending on the occurrence of corrugation. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Special Publication No. 60-030802 [Patent Document 2] Japanese Patent Application Publication No. 03-103502 [Patent Document 3] Japanese Patent Application Laid-Open No. 2001-317930 [Patent Document 4] Japanese Patent Application Laid-Open No. 2014-074286 [Patent Document 5] Japanese Patent Application Laid-Open No. 2017-133153 Summary of the Invention [Problem to be solved by the invention]

[0009] As mentioned above, in conventional rail grinding work, one grinding pattern is selected from multiple patterns (combinations of grinding wheel angle, grinding wheel pressure, grinding car travel speed, and number of grinding passes) owned by railway operators and other organizations, and a certain section of rail is uniformly ground. However, the amount of grinding required varies depending on the degree of unevenness, such as rail corrugation, and the amount of grinding obtained by rail grinding may decrease depending on the combination of the grinding pattern and the rail cross-sectional shape. As a result, problems arise in terms of economic losses due to excessive grinding, and rail maintenance, such as not being able to obtain the required amount of grinding on the rail head surface, not being able to completely remove the fatigue layer, or not being able to completely remove rail unevenness. Therefore, it is desirable to apply the optimal grinding pattern for each section depending on the rail cross-sectional shape.

[0010] In this regard, the rail grinding method described in Patent Document 1 automatically corrects the grinding pattern taking into account the rail cross-sectional shape during rail grinding, but has the problem of making it difficult to optimize the grinding pattern from the planning stage of rail grinding. Furthermore, the rail grinding methods described in Patent Documents 2 and 3 automatically create an optimal rail grinding plan, including a grinding pattern, from rail cross-sectional shape data acquired by measuring devices mounted on rail grinding vehicles or rail flaw detection vehicles, but have the problem that data related to the rail cross-sectional shape with the accuracy required for rail grinding may not be obtained due to the influence of vibrations associated with vehicle movement. Furthermore, the rail grinding method described in Patent Document 4 acquires the rail cross-sectional shape using a fixed measuring device at a fixed position on the ground in the rail grinding section, but has the problem that the measurement is labor-intensive and therefore difficult to use for evaluating the entire line. Furthermore, the rail grinding method described in Patent Document 5 can determine the number of grinding passes required to remove rail corrugation from continuous data on rail irregularities measured on the ground or on board the vehicle, but because it does not take into account the cross-sectional shape of the rail, there is a problem in that the required amount of grinding cannot be obtained for rails with flat cross-sectional shapes, and rail corrugation may remain.

[0011] The present invention has been made in consideration of the above problems, and aims to provide a rail grinding method selection method and rail grinding method selection system that optimize and streamline rail grinding work by using a rail cross-sectional shape classification method that is not easily affected by the measurement accuracy of rail cross-sectional shape data and a method for selecting the most appropriate pattern from existing grinding patterns using the classification method. [Means for solving the problem]

[0012] The rail grinding method selection method according to the present invention comprises: a contour shape measurement step of measuring at least the contour shape in the rail cross section direction; a design value acquisition step of acquiring design values ​​for the contour shape in the rail cross section direction; a superposition step of superimposing the contour shape measured in the contour shape measurement step on the design values; and a design difference area calculation step of calculating a design difference area between the contour shape and the design value. a normalization step of calculating a maximum value of the design area difference, which is the area difference from the design value when the rail head shape is assumed to be a straight line perpendicular to the rail height direction, and dividing the design area difference by the maximum value of the design area difference to obtain a design area difference ratio, which is a normalized value; The aforementioned Design differential area ratio Cross-sectional shape evaluation index Used as and a grinding pattern selection process for selecting a grinding pattern corresponding to the evaluation index. The grinding pattern selection step sets a threshold value that is set based on the relationship between the design difference area ratio and the corresponding rail grinding amount, and selects, for each certain section on the track from the kilometer distance on the track, a grinding pattern for a section where the design difference area ratio is higher than the threshold value and a grinding pattern for a section where the design difference area ratio is lower than the threshold value. It is characterized by:

[0013] In addition, in the rail grinding method selection method according to the present invention, it is preferable that the contour shape measurement step includes an extraction step of extracting shape data of the rail head portion included in a range on at least one of the field corner side and the gauge corner side of the center position of the cross section of the rail.

[0014] Furthermore, in the rail grinding operation selection method according to the present invention, it is preferable that the extraction step includes a rejection step of rejecting the rail head shape data from the analysis targets when the number of samples of the extracted rail head shape data is less than a predetermined threshold value, or when the rail head shape data exceeds a predetermined threshold value.

[0015] In addition, in the method for selecting rail grinding work according to the present invention, it is preferable that the contour shape measurement step and the design value acquisition step include a resampling processing step in which a resampling process is performed on the measured contour shape and design values ​​so that they are spaced equally apart in the cross-sectional direction of the rail.

[0017] Furthermore, the rail grinding operation selection system according to the present invention comprises: a contour shape measuring means for measuring at least the contour shape in the rail cross section direction; a design value acquiring means for acquiring a design value of the contour shape in the rail cross section direction; a superimposing means for superimposing the contour shape measured by the contour shape measuring means on the design value; and a design difference area calculating means for calculating a design difference area between the contour shape and the design value. a normalization means for calculating a maximum value of the design area difference, which is the area difference from the design value when the rail head shape is assumed to be a straight line perpendicular to the rail height direction, and for calculating a design area difference ratio, which is a normalized value obtained by dividing the design area difference by the maximum value of the design area difference; The aforementioned Design differential area ratio Cross-sectional shape evaluation index Used as and a grinding pattern selection means for selecting a grinding pattern corresponding to the evaluation index. The grinding pattern selection means sets a threshold value that is set based on the relationship between the design difference area ratio and the corresponding rail grinding amount, and selects, for each fixed section on the track from the kilometer distance on the track, a grinding pattern for a section where the design difference area ratio is higher than the threshold value and a grinding pattern for a section where the design difference area ratio is lower than the threshold value. It is characterized by:

[0018] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions. [Effects of the Invention]

[0019] In a rail grinding shape selection method according to the present invention, when an excessive number of grinding passes is required for a section where rail grinding is being performed using a uniform grinding pattern with a rail grinding vehicle due to the presence of sections with different rail cross-sectional shapes, the method extracts sections to which a grinding pattern with fewer grinding passes (number of grinding passes) can be applied based on measurement data of the rail cross-sectional shape obtained by a rail cross-sectional shape measuring device installed on a track inspection vehicle or the like, thereby reducing the number of grinding passes for the entire section at the rail grinding planning stage and expanding the length of rail grinding work.In addition, when a section has an insufficient number of grinding passes, the method extracts sections that require a grinding pattern with a larger amount of grinding (more grinding passes) based on measurement data of the rail cross-sectional shape obtained by a rail cross-sectional shape measuring device installed on a track inspection vehicle or the like, thereby reducing the number of sections where the amount of grinding on the rail head surface is insufficient and appropriately removing the fatigue layer of the rail, thereby extending the rail replacement life and preventing rail breakage. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing an overview of a rail grinding method selection system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a flow chart showing an overview of a method for selecting a rail grinding method according to an embodiment of the present invention. [Figure 3] FIG. 10 is a diagram for explaining an example of the overlapping step and the method for calculating the difference area in the rail grinding method selection method according to the embodiment of the present invention. [Figure 4] FIG. 10 is a conceptual diagram illustrating calculation of a threshold value used to select a rail grinding pattern in the rail grinding method selection method according to an embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing an example of a method for selecting a rail grinding pattern in the method for selecting a rail grinding method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0022] FIG. 1 is a diagram showing an overview of a system for selecting a rail grinding method according to an embodiment of the present invention, FIG. 2 is a flow diagram showing an overview of a method for selecting a rail grinding method according to an embodiment of the present invention, FIG. 3 is a diagram for explaining an example of the superposition process and method for calculating a differential area in the method for selecting a rail grinding method according to an embodiment of the present invention, FIG. 4 is a conceptual diagram of threshold calculation used for selecting a rail grinding pattern in the method for selecting a rail grinding method according to an embodiment of the present invention, and FIG. 5 is a diagram showing an example of a method for selecting a rail grinding pattern in the method for selecting a rail grinding method according to an embodiment of the present invention.

[0023] As shown in FIG. 1, the rail grinding method selection system according to this embodiment includes a measuring means 11 mounted on a railway vehicle 1 running on a track 2, and a processing means 12 that processes rail cross-sectional shape data and design values ​​measured by the measuring means 11.

[0024] The measuring means 11 performs measurements in the same manner as conventionally known rail flaw detection vehicles and the like, and therefore detailed description of the measuring means 11 will be omitted, but the measuring means 11 includes an optical measuring device, a light receiving element, etc. Furthermore, it is also possible to use data that has been resampled in advance to include information about distance using data related to the running speed of the railway vehicle 1 that is measured simultaneously with the optical measuring device, etc.

[0025] Next, the operation of the rail grinding method selection system according to this embodiment will be described. As shown in Figure 2, the rail grinding method selection method according to this embodiment includes at least a contour shape measurement step (S101) for measuring the contour shape in the rail cross-sectional direction, a design value acquisition step (S102) for acquiring design values ​​for the contour shape in the rail cross-sectional direction, a superposition step (S103) for superimposing the contour shape measured in the contour shape measurement step (S101) on the design values, a design difference area calculation step (S104) for calculating a design difference area between the contour shape and the design value, and a grinding pattern selection step (S105) for determining an evaluation index for the cross-sectional shape from the design difference area and selecting a grinding pattern corresponding to the evaluation index.

[0026] The contour shape measurement process (S101) also includes a contour shape data measurement process (S111) for measuring the contour shape, an extraction process (S112) for extracting data on the rail head from the contour shape, a rejection process (S113) for discarding unnecessary data from the extracted data, and a resampling process (S114) for resampling the measured contour shape so that it is equally spaced in the cross-sectional direction of the rail.

[0027] The design value acquisition process (S102) also includes a design value data acquisition process (S121) for acquiring design values, and a resampling process (S122) for performing resampling of the acquired design values ​​so that they are spaced equally in the rail cross-sectional direction.

[0028] The grinding pattern selection process (S105) also includes a normalization process (S131) ​​that calculates the maximum design difference area, which is the difference area from the design value when the rail head shape is assumed to be a straight line shape perpendicular to the rail height direction, and normalizes the design difference area by dividing the design difference area by the maximum design difference area to obtain a design difference area ratio, and a pattern selection process (S132) that selects a grinding pattern for the relevant section depending on the design difference area ratio obtained by the normalization process.

[0029] The rail grinding method selection method according to this embodiment is preferably performed by processing means 12, and a processing device such as a computer is preferably used as the processing means 12. The processing device includes an arithmetic unit such as a CPU (Central Processing Unit) that executes the processing program, a ROM (Read Only Memory) that stores the processing program, and a RAM (Random Access Memory) that temporarily stores data required for CPU processing. The processing device also preferably includes input devices such as a keyboard, mouse, and touch panel, output devices such as a CRT (Cathode-Ray-Tube) display, LCD display, and printer, and a communication interface.

[0030] Such a processing device is preferably a computer system constructed within a computer, and such computers are preferably, for example, personal computers, workstations, servers, tablet computers, etc., and various types of computers can be used as long as they operate according to a program such as application software recorded in a storage device, and may be a single computer or a group of computers in which multiple computers are connected so that they can communicate via a network or the like.

[0031] The contour shape data measurement step (S111) acquires data on the contour shape of the rail in the cross-sectional direction (hereinafter referred to as "rail cross-sectional shape data") using a measuring device 11 or the like installed on a railway vehicle 1, such as a track inspection vehicle. The rail cross-sectional shape data used in the rail grinding method selection method according to this embodiment does not need to include the entire cross section of the rail (all of the head, web, and bottom), but only needs to include the cross-sectional shape of the rail head (hereinafter referred to as "rail head shape"). Here, the rail cross-sectional shape data acquired by the measuring device 11 on the railway vehicle 1 (track inspection vehicle, rail grinding vehicle, and rail flaw detection vehicle) is preferably used in the rail grinding method selection method according to this embodiment because it is recorded in synchronization with data related to kilometerage and can acquire the rail cross-sectional shape over a long section in the longitudinal direction of the track, but it may also be used. Furthermore, measurement of rail cross-sectional shape data is not limited to measurement using a measuring means 11 or the like installed on the railway vehicle 1, but the rail cross-sectional shape of a certain section may also be measured, for example, using a small, portable measuring device fixed in a fixed position on the ground.

[0032] The extraction step (S112) extracts rail head shape data (hereinafter referred to as "rail head shape data") included in the range toward the field corner from the center position of the rail cross section, from the rail cross-sectional shape data acquired in the contour shape data measurement step (S111), as shown in Fig. 3. The same process is performed on the design shape of the rail head shape data, and design values ​​for the rail head shape data are extracted.

[0033] In the rejection step (S113), data that meet certain conditions are rejected from the rail head shape data extracted in the extraction step (S112). Specifically, because it is difficult to evaluate the rail head shape when the number of data samples is small due to missing measurements or other reasons, if the number of samples of the aforementioned rail head shape data is below a threshold, such rail head shape data is rejected from the analysis target. Furthermore, if vertical fluctuations are observed in the rail head shape data extracted in the extraction step (S112), it is considered that the data is influenced by measurement noise other than the actual rail head shape. For this reason, data whose fluctuations (standard deviation) within a certain range of the rail head shape data exceed a predetermined threshold are rejected from the analysis target. The threshold in this case can be set appropriately taking into account the measurement environment, etc.

[0034] In the resampling process step (S114), the rail head shape data extracted in the extraction process (S112) is resampled so that the data plots of the rail head shape data are spaced at equal intervals across the width of the rail cross section. Various well-known resampling methods can be applied, but for example, resampling by linear interpolation is preferably used.

[0035] The design value data acquisition step (S121) acquires data related to the design values ​​of the rail cross-sectional profile at the time of designing the rail to be reground. The design values ​​can be acquired by loading the data into a processing device or by manually entering the values.

[0036] In the resampling process step (S122), similar to the resampling process step (S114) in the contour shape measurement process (S101) described above, resampling is performed on the design value rail head shape data so that the data plots of the rail head shape data are spaced at equal distances across the width of the rail cross section.

[0037] In the overlapping process (S103), as shown in FIG. 3, the two rail head shape data, the measured shape that has been resampled and the design value, are overlapped by matching the maximum height values ​​of both and the widthwise positions of the rail head side surface.

[0038] In the design difference area calculation step (S104), the area enclosed by the two rail head shape data sets that were overlaid in the overlay step (S103) (hereinafter referred to as the "design difference area") is calculated. Specifically, as shown in FIG. 3, the area enclosed by the measured shape and the design shape of the overlaid rail head shape data is calculated. The design difference area can be defined as any range from the center position CL of the rail cross section to the side surface of the rail head (in this embodiment, the field corner side), but it is desirable to calculate this range within a range that is less susceptible to measurement noise. For example, for JIS 50 kgN rails and JIS 60 kg rails, the calculation range for the design difference area is preferably set to a range of 5 mm to 30 mm from the center position of the design rail cross section toward the side surface of the rail head. This is because the side surface of the rail head shape data has arc-shaped corners, which means that the rate of change in area is large and it is therefore more susceptible to noise, and therefore is excluded from the calculation of the design difference area.

[0039] In the normalization step (S131), when performing the overlay process in the overlay step (S103), the "maximum design difference area" is defined as the design difference area obtained when the rail head shape is considered to be a straight line perpendicular to the rail height direction at the position of the maximum value in the rail height direction (y=0), as shown in Figure 3, and the "design difference area" is divided by the "maximum design difference area" to calculate a normalized value (hereinafter referred to as the "design difference area ratio"). In the rail grinding method selection method according to this embodiment, the design difference area ratio is used as an evaluation index for the rail cross-sectional shape.

[0040] The inventors have confirmed through their studies that the threshold value of the design difference area ratio used in selecting a grinding pattern (described later), which is the rail grinding amount when rail grinding work is actually performed using the same rail grinding pattern and the design difference area ratio before rail grinding, can be set from the relationship between the design difference area ratio and the corresponding rail grinding amount, as shown in Figure 4. Therefore, after investigating the relationship between the rail grinding amount and the design difference area ratio before rail grinding, for example, if the fatigue layer removal is 0.1 mm and the rail corrugation wave height is a maximum of 0.2 mm, and a total of 0.3 mm of rail grinding is desired, the threshold value of the design difference area ratio can be set to 0.4 based on the relationship between the rail grinding amount and the design difference area ratio.

[0041] The pattern selection process (S132) sets the above-mentioned threshold for selecting a grinding pattern to the value of the design difference area ratio calculated in the normalization process (S131), and selects the optimal pattern from existing grinding patterns for each certain section of the track based on the design difference area ratio calculated in the normalization process (S131) ​​and the kilometerage on the track acquired in the contour shape data measurement process (S111), as shown in Figure 5. Specifically, for sections where the design difference area ratio is higher than the threshold, grinding pattern A, which has a large number of grinding passes, can be selected, and for sections where the design difference area ratio is lower than the threshold, grinding pattern B, which has a small number of grinding passes, can be selected.

[0042] Thus, according to the rail grinding method selection method of this embodiment, when a section where rail grinding is being performed using a uniform grinding pattern by a rail grinding vehicle includes sections with different rail cross-sectional shapes, and an excessive number of grinding passes is required, the rail grinding method selection method of this embodiment can be used to extract sections to which a grinding pattern with fewer grinding passes can be applied based on measurement data of the rail cross-sectional shape obtained by a track inspection vehicle or the like. This reduces the number of grinding passes for the entire section at the rail grinding planning stage and enables the extension of the rail grinding work length. In addition, when a section includes an insufficient number of grinding passes, the method can extract sections that require a grinding pattern with a larger amount of grinding (more grinding passes) based on measurement data of the rail cross-sectional shape obtained by a track inspection vehicle or the like. This reduces the number of sections where the amount of grinding on the rail head surface is insufficient, thereby extending the rail replacement life and preventing rail breakage. This enables the creation of an efficient rail grinding plan for sections where rail grinding work is to be performed.

[0043] The method for selecting a rail grinding method according to the present embodiment has been described above in terms of a case in which the design difference area is calculated in the range from the center position of the rail cross section toward the field corner side. However, taking into account the grinding history of the rail, the calculation may be performed in the range toward the gauge corner side, or in the range from the field corner side to the gauge corner side.

[0044] Furthermore, the rail grinding method selection method according to the present embodiment described above has been explained with two patterns of large and small grinding passes, with the design difference area ratio set to 0.4 as the threshold for determining the pass pattern, but the number of pass patterns is not limited to two, and multiple pass patterns may be set by setting multiple thresholds for the design difference area ratio according to the amount of grinding of the top surface. It is clear from the claims that such modified or improved embodiments are also included within the technical scope of the present invention. [Explanation of symbols]

[0045] 1 railway vehicle, 2 track, 11 measuring means, 12 processing means.

Claims

1. a contour shape measuring step of measuring a contour shape at least in a cross-sectional direction of the rail; a design value acquisition step of acquiring design values ​​for the rail cross-sectional direction profile shape; a superposition step of superimposing the contour shape measured in the contour shape measurement step on the design value; a design difference area calculation step of calculating a design difference area between the contour shape and the design value; a normalization step of calculating a maximum value of the design area difference, which is the area difference from the design value when the rail head shape is assumed to be a straight line perpendicular to the rail height direction, and dividing the design area difference by the maximum value of the design area difference to obtain a design area difference ratio, which is a normalized value; a grinding pattern selection step of using the design difference area ratio as an evaluation index for a cross-sectional shape and selecting a grinding pattern corresponding to the evaluation index; a grinding pattern selection step for selecting a rail grinding method, the grinding pattern selection step comprising: setting a threshold value based on the relationship between the design difference area ratio and the corresponding rail grinding amount; and selecting, for each fixed section on the track based on the design difference area ratio and the kilometer distance on the track, a grinding pattern for a section where the design difference area ratio is higher than the threshold value, and a grinding pattern for a section where the design difference area ratio is lower than the threshold value.

2. 2. The rail grinding method selection method according to claim 1, A rail grinding method selection method characterized in that the contour shape measurement step includes an extraction step of extracting shape data of the rail head portion included in at least one of the ranges on the field corner side and the gauge corner side from the center position of the rail cross section.

3. 3. The rail grinding method selection method according to claim 2, A rail grinding method selection method characterized in that the extraction step comprises a rejection step of rejecting the rail head shape data from analysis when the number of samples of the extracted rail head shape data is less than a predetermined threshold value or when the rail head shape data exceeds a predetermined threshold value.

4. 2. The rail grinding method selection method according to claim 1, A rail grinding method selection method, characterized in that the contour shape measurement process and the design value acquisition process include a resampling process that performs resampling processes on the measured contour shape and design values ​​so that they are spaced equally apart in the rail cross-sectional direction.

5. a contour shape measuring means for measuring a contour shape in at least the cross-sectional direction of the rail; a design value acquisition means for acquiring design values ​​of the rail cross-sectional profile; a superposition means for superimposing the contour shape measured by the contour shape measuring means on the design value; a design difference area calculation means for calculating a design difference area between the contour shape and the design value; a normalization means for calculating a maximum value of the design area difference, which is the area difference from the design value when the rail head shape is assumed to be a straight line perpendicular to the rail height direction, and for calculating a design area difference ratio, which is a normalized value obtained by dividing the design area difference by the maximum value of the design area difference; a grinding pattern selection means for selecting a grinding pattern corresponding to the evaluation index by using the design difference area ratio as an evaluation index for a cross-sectional shape, a grinding pattern selection means for selecting a rail grinding method, the grinding pattern selection means providing a threshold value set from the relationship between the design difference area ratio and the corresponding rail grinding amount, and selecting, for each fixed section on the track based on the design difference area ratio and the kilometer distance on the track, a grinding pattern for a section where the design difference area ratio is higher than the threshold value, and a grinding pattern for a section where the design difference area ratio is lower than the threshold value.

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