A method for on-line evaluation of rail repair accuracy

Abstract

The application discloses a kind of online evaluation method of rail repair precision, including steps 1: calculating profile dynamic adaptation DPA;Step 2: calculating disease residual correction DRC;Step 3: calculating surface roughness standard degree SRC;Step 4: calculating polishing quality uniformity GUI;Step 5: calculating rail polishing quality comprehensive evaluation index CGQI, the present application fuses profile dynamic adaptation, disease residual correction, surface roughness standard, polishing uniformity these four dimensions, forms comprehensive evaluation system (CGQI), based on rail basic parameters and the contact pressure deduced based on Hertz contact theory, combined with laser profile measurement deviation, realize the dynamic evaluation of "the greater the contact pressure, the higher the deviation influence weight", it is in line with actual service working condition;Supplement microelement area division, profile alignment reference, deviation limit and other key rules, solve engineering landing pain points;Give consideration to macro profile, residual disease, micro roughness, polishing uniformity, more comprehensive evaluation.

Description

Technical Field

[0001] This invention belongs to the field of rail repair and relates to an online evaluation method for rail repair accuracy. Background Technology

[0002] During service, railway rails are constantly subjected to complex and variable loads from train wheels, making them prone to various damages and defects, such as corrugation, cracks, peeling, crushing, and edge thickening. When rail defects occur, the rail surface needs to be ground, and the grinding quality needs to be evaluated afterward. Existing rail grinding quality evaluation methods (such as GQI) focus on static profile matching, which has limitations such as fixed weights, failure to differentiate the severity of defects, and neglect of surface micro-quality. This application effectively solves the above problems. Summary of the Invention

[0003] In order to overcome at least one deficiency of the prior art, the present invention provides an online evaluation method for rail repair accuracy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an online evaluation method for rail repair accuracy, comprising... Step 1: Calculate the Dynamic Profile Fit (DPA); Step 2: Calculate the disease residual correction factor (DRC); Step 3: Calculate the surface roughness compliance (SRC); Step 4: Calculate the uniformity of polishing quality (GUI); Step 5: Calculate the Comprehensive Quality Evaluation Index (CGQI) for rail grinding.

[0005] Furthermore, the method for calculating the dynamic profile fit (DPA) is as follows: Step 11: Obtain rail foundation parameters; Step 12: Divide the rail head width direction into n infinitesimal regions Z according to the infinitesimal width Δf. i ; Step 13: Calculate the contact pressure P in each micro-element region i ; Step 14: Weight the contact pressure Normalization processing; Step 15: Calculate the normal deviation based on the profiler measurement results. ; Step 16: Calculate the dynamic profile fit (DPA).

[0006] Furthermore, the contact pressure P of each micro-element region in the above steps i The formula is Where, x i For the infinitesimal element Zi The center x-axis coordinate, For maximum contact pressure, h is the semi-major axis of the contact ellipse. j is the minor semi-axis of the contact ellipse. F represents the vertical load on the rail.

[0007] Furthermore, the contact pressure weight The formula is .

[0008] Furthermore, the method in step 15 is as follows: Profile alignment: Using the track gauge point as a reference, the profile measured by the laser profile measuring instrument is translated along the Y-axis to align with the target profile; Deviation calculation: for each infinitesimal element Calculate the shortest normal distance between the measured profile and the target profile, and take the absolute value as... ; Deviation handling: If > ,according to = deal with, This is the limit for normal deviation.

[0009] Furthermore, the formula for the dynamic profile fit (DPA) is as follows: DPA ∈ [0,100].

[0010] Furthermore, the method in step 2 is as follows: Set disease severity levels, with different levels corresponding to different correction coefficients. ; The formula for the residual disease correction factor (DRC) is: Where m is the number of residual disease types; when there are no residual diseases, DRC=100.

[0011] Furthermore, the surface roughness compliance (SRC) formula is as follows: in, This represents the measured surface roughness value. For optimal roughness, To minimize roughness, This represents the maximum roughness.

[0012] Furthermore, the method in step 4 includes... Step 41: Calculate the grinding amount t for a single cross-section k; The grinding amount is the deviation area between the measured profile and the target profile, representing the total amount of material that needs to be ground away from that section. The formula is: Among them, t k The grinding amount (in mm) for the k-th cross-section 2 k=1,2,...,n1, where n1 is the number of cross-sections. Let x be the target profile function, x be the coordinate of the railhead width direction, and f(x) be the corresponding height. The measured profile function of the cross-section; integral To measure the area to be ground, the deviation values ​​of all infinitesimal elements along the rail head width direction are summed by integration. The laser profiler will output the coordinates of discrete points along the rail head width direction, and the integral can be approximated by the trapezoidal rule. in, Let be the width coordinate of the i-th discrete point, where i = 1, 2, 3, ..., mm, and mm is the number of discrete points within the grinding area. The distance between discrete points; Step 42: Calculate the coefficient of variation (CV(t)) of the grinding amount. k ); CV(t k The ratio of standard deviation to mean is used to eliminate the influence of the mean value of grinding amount and objectively reflect the degree of dispersion. in, This represents the average amount of polishing. ; For the standard deviation of polishing amount, Step 43: Calculate the GUI; The GUI is used to score the uniformity of the polishing quality. The maximum allowable coefficient of variation for achieving uniformity in polishing. If CV(t) k If )=0, then GUI=100 points; if CV(t)=0, then GUI=100 points; k )=CV lim If GUI = 0, then the score is zero; if it is between 0 and 1, the score decreases linearly; when CV(t) = 0, the score decreases linearly. k )>CV lim If the score is 0, then GUI is judged to be 0.

[0013] Furthermore, the formula for the Comprehensive Evaluation Index (CGQI) of rail grinding quality is as follows: in, , , , The weights are dynamic and adjusted according to the route scenario.

[0014] In summary, the advantages of this invention are: This invention integrates four dimensions—dynamic profile adaptation, residual defect correction, surface roughness compliance, and grinding uniformity—to form a comprehensive evaluation system (CGQI). Based on rail foundation parameters and Hertzian contact theory, it derives contact pressure and combines it with measured deviations in laser profile analysis to achieve dynamic evaluation where "the greater the contact pressure, the higher the weight of the deviation," closely aligning with actual service conditions. It supplements key rules such as micro-element region division, profile alignment benchmarks, and deviation limits to address pain points in engineering implementation. It considers macro-profile, residual defects, micro-roughness, and grinding uniformity for a more comprehensive evaluation. The weights and key parameters (deviation limits, roughness thresholds) can be flexibly adjusted according to high-speed / conventional speed and straight / turnout conditions, demonstrating strong versatility. Attached Figure Description

[0015] Figure 1 This is a flowchart of the online evaluation method of the present invention. Detailed Implementation

[0016] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0017] Example: like Figure 1 As shown, an online evaluation method for rail repair accuracy includes...

[0018] Step 1: Calculate the Dynamic Profile Fit (DPA); The steps for calculating the Dynamic Profile Fit (DPA) include: Step 11: Obtain rail foundation parameters; The rail foundation parameters are shown in Table 1: Table 1 Step 12: Divide the rail head width direction into n infinitesimal regions Z according to the infinitesimal width Δf. i ; The width of the infinitesimal element is Δf = 0.5 mm, and the region of the infinitesimal element is Z. i(i=1,2,...,n), infinitesimal region Z i Covers the core contact area of ​​the rail (±25mm from the center of the rail top); Step 13: Calculate the contact pressure P in each micro-element region i ; Contact pressure P in each micro-element region i The formula is: Where, x i For the infinitesimal element Z i Center x-axis coordinate, y i For the infinitesimal element Z i The central y-axis coordinate, y i Very small, remember y i =0; P i The formula has been updated to in, For maximum contact pressure, h is the major semi-axis of the contact ellipse (along the width direction of the rail head). j is the minor semi-axis of the contact ellipse (along the length of the rail). R is the equivalent radius of curvature. ; For the equivalent elastic modulus, .

[0019] Step 14: Weight the contact pressure Normalization processing; The greater the contact pressure, the higher the weight, reflecting the dynamic evaluation logic. Step 15: Calculate the normal deviation based on the profiler measurement results. ; Profile alignment: Using the track gauge point (16mm below the highest point of the track top) as a reference, translate the profile measured by the laser profile measuring instrument along the Y-axis to align it with the target profile; Deviation calculation: for each infinitesimal element Calculate the shortest normal distance between the measured profile and the target profile, and take the absolute value as... ; Deviation handling: If > ,according to = Handling (to avoid excessive deviations that could lead to distorted evaluations). This is the limit for normal deviation.

[0020] Step 16: Calculate the Dynamic Profile Fit (DPA); DPA ∈ [0,100], the higher the score, the better the dynamic fit of the profile.

[0021] Step 2: Calculate the disease residual correction factor (DRC); Set the severity level of the disease: Fatal defects (L1): Cracks (length ≥ 3 mm), spalling (area ≥ 5 mm²), correction factor =0.3; Severe disease (L2): Excessive lip growth (height ≥ 0.5 mm), peeling (area ≥ 10 mm²), correction factor. =0.7; Minor damage (L3): minor scratches, fish-scale pattern (depth <0.2mm), correction factor. =0.95; DRC formula for disease residue correction: Where m is the number of residual disease types; if there are 2 disease types, then m=2. is the correction factor for the j-th type of disease. When there are no residual diseases, DRC=100.

[0022] Step 3: Calculate the surface roughness compliance (SRC); The surface roughness compliance (SRC) formula is: in, The surface roughness is measured (one measuring point is taken every 1 meter, and the average value is taken; high-speed rail). Ordinary speed rail ); For optimal roughness (midpoint of the threshold interval, such as high-speed rail) = 2.0 ), To minimize roughness, This represents the maximum roughness.

[0023] Step 4: Calculate the uniformity of polishing quality (GUI); The quality of grinding depends not only on whether the profile of a single section meets the standard (DPA has been evaluated), but also on whether the grinding amount is uniform throughout the entire rail section. Even if a single section has a high DPA score, large differences in grinding amount between adjacent sections can still lead to unstable rail contact and shortened rail service life. The coefficient of variation (CV) is used to eliminate the influence of the average grinding amount and quantify the dispersion of the grinding amount. A maximum allowable coefficient of variation (CV) is set. lim The score is calculated by the ratio of the actual coefficient of variation to the allowable value, thus realizing the evaluation logic that the better the uniformity, the higher the score.

[0024] Step 41: Calculate the grinding amount t for a single cross-section k ; The grinding amount is the deviation area between the measured profile and the target profile, representing the total amount of material that needs to be ground away from that section. The formula is: Among them, t k Grinding amount for the k-th cross-section (unit: mm) 2 ), k=1,2,...,n1 (n1 is the number of cross-sections, usually one cross-section is taken per meter), The target profile function (x is the coordinate of the railhead width direction, and f(x) is the corresponding height); The measured profile function of the cross-section (data acquired by a laser profiler and aligned with the track gauge points); integration To account for the area being ground (rather than single-point deviation), the deviation values ​​of all infinitesimal elements along the rail head width direction need to be summed by integration. The laser profiler will output the coordinates of discrete points along the rail head width direction (e.g., one point every 0.1 mm), and the integral can be approximated using the trapezoidal rule. in, Let be the width coordinate of the i-th discrete point, where i = 1, 2, 3, ..., mm, and mm is the number of discrete points within the grinding area. The discrete point spacing (sampling interval of the laser profiler, here taken as 0.1mm); Step 42: Calculate the coefficient of variation (CV(t)) of the grinding amount. k ); CV(t k The ratio of standard deviation to mean is used to eliminate the influence of the mean value of grinding amount and objectively reflect the degree of dispersion. in, This represents the average amount of polishing. ; For the standard deviation of polishing amount, .

[0025] Step 43: Calculate the GUI; The GUI provides a score for the uniformity of the polishing quality (range 0-100 points, the higher the score, the better the uniformity). The maximum allowable coefficient of variation for achieving uniformity in polishing. If CV(t) k If CV(t) = 0 (the polishing amount is completely uniform), then GUI = 100 points; if CV(t) = 0 (the polishing amount is completely uniform), then GUI = 100 points; k )=CVlim (If the maximum allowable dispersion is reached), then GUI = 0 points; if it is between these two values, the score decreases linearly; when CV(t) k )>CV lim When that happens, GUI score is determined to be 0.

[0026] Step 5: Calculate the Comprehensive Quality Evaluation Index (CGQI) for rail grinding. in, , , , The weighting is dynamic, adjusted according to the line scenario. Priority is given to increasing the DPA weight for critical areas (such as turnouts) and high-speed lines. The specific allocation is shown in Table 2. CGQI ∈ [0,100], the higher the score, the better the polishing quality. The correlation between CGQI score, quality level, and recommendations is shown in Table 3: Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. An online evaluation method for rail repair accuracy, characterized in that: include Step 1: Calculate the Dynamic Profile Fit (DPA); Step 2: Calculate the disease residual correction factor (DRC); Step 3: Calculate the surface roughness compliance (SRC); Step 4: Calculate the uniformity of polishing quality (GUI); Step 5: Calculate the Comprehensive Quality Evaluation Index (CGQI) for rail grinding.

2. The online evaluation method for rail repair accuracy according to claim 1, characterized in that: The method for calculating the dynamic profile fit (DPA) is as follows: Step 11: Obtain rail foundation parameters; Step 12: Divide the rail head width direction into n infinitesimal regions Z according to the infinitesimal width Δf. i ; Step 13: Calculate the contact pressure P in each micro-element region i ; Step 14: Weight the contact pressure Normalization processing; Step 15: Calculate the normal deviation based on the profiler measurement results. ; Step 16: Calculate the dynamic profile fit (DPA).

3. The online evaluation method for rail repair accuracy according to claim 2, characterized in that: The contact pressure P of each micro-element region in the step i The formula is , where x i For the infinitesimal element Z i The center x-axis coordinate, For maximum contact pressure, h is the semi-major axis of the contact ellipse. j is the minor semi-axis of the contact ellipse. F represents the vertical load on the rail.

4. The online evaluation method for rail repair accuracy according to claim 2, characterized in that: The contact pressure weight The formula is 。 5. The online evaluation method for rail repair accuracy according to claim 2, characterized in that: The method for step 15 is as follows: Profile Alignment: Using the track gauge point as a reference, the profile measured by the laser profile measuring instrument is translated along the Y-axis to align with the target profile; Deviation Calculation: For each micro-element... Calculate the shortest normal distance between the measured profile and the target profile, and take the absolute value as... ; Deviation handling: If > ,according to = deal with, This is the limit for normal deviation.

6. The online evaluation method for rail repair accuracy according to claim 2, characterized in that: The formula for the dynamic profile fit (DPA) is as follows: ,DPA ∈ [0,100]。 7. The online evaluation method for rail repair accuracy according to claim 1, characterized in that: The method in step 2 is as follows: Set disease severity levels, with different levels corresponding to different correction coefficients. ; The formula for the residual disease correction factor (DRC) is: Where m is the number of residual disease types; when there are no residual diseases, DRC=100.

8. The online evaluation method for rail repair accuracy according to claim 1, characterized in that: The surface roughness compliance (SRC) formula is as follows: ,in, This represents the measured surface roughness value. For optimal roughness, To minimize roughness, This represents the maximum roughness.

9. The online evaluation method for rail repair accuracy according to claim 1, characterized in that: The method in step 4 includes Step 41: Calculate the grinding amount t for a single cross-section k ; The grinding amount is the deviation area between the measured profile and the target profile, representing the total amount of material that needs to be ground away from that section. The formula is: , where t k The grinding amount (in mm) for the k-th cross-section 2 k=1,2,...,n1, where n1 is the number of cross-sections. Let x be the target profile function, x be the coordinate of the railhead width direction, and f(x) be the corresponding height. The measured profile function of the cross-section; integral To measure the area to be ground, the deviation values ​​of all infinitesimal elements along the rail head width direction are summed by integration. The laser profiler will output the coordinates of discrete points along the rail head width direction, and the integral can be approximated by the trapezoidal rule. ,in, Let be the width coordinate of the i-th discrete point, where i = 1, 2, 3, ..., mm, and mm is the number of discrete points within the grinding area. The distance between discrete points; Step 42: Calculate the coefficient of variation (CV(t)) of the grinding amount. k ); CV(t k The ratio of standard deviation to mean is used to eliminate the influence of the mean value of grinding amount and objectively reflect the degree of dispersion. ,in, This represents the average amount of polishing. ; For the standard deviation of polishing amount, Step 43: Calculate the GUI; The GUI is the score for the uniformity of the polishing quality; The maximum allowable coefficient of variation for achieving uniformity in polishing. If CV(t) k If )=0, then GUI=100 points; if CV(t)=0, then GUI=100 points; k )=CV lim If GUI = 0, then the score is zero; if it is between 0 and 1, the score decreases linearly; when CV(t) = 0, the score decreases linearly. k )>CV lim If the score is 0, then GUI is judged to be 0.

10. The online evaluation method for rail repair accuracy according to claim 1, characterized in that: The formula for the Comprehensive Quality Evaluation Index (CGQI) of rail grinding is as follows: ,in, , , , The weights are dynamic and adjusted according to the route scenario.

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