A method for evaluating platform gauge measurement error

Abstract

The application discloses a kind of platform limit measurement error evaluation methods, the platform limit measurement error evaluation methods, comprising: measuring the parameter value of each limit size of platform using measuring trolley;The parameter value obtained in step 1 is substituted into the corresponding limit size formula, and the numerical value of the corresponding limit size is calculated;Move the measuring trolley, repeat the measurement at a given unit step length, and record the data;Establish a measurement model, calculate the uncertainty of each component of the measurement model, calculate the total combined standard uncertainty u ci , and calculate the expanded uncertainty U, compare the calculated value of U with the half-width value of the maximum allowed error interval of the corresponding limit size, if the calculated value of U is less than the half-width value, it can be judged that the measured limit size parameter is qualified. The method of the above steps can evaluate the related parameter measurement of platform limit size measurement, so as to ensure the accuracy and reliability of measurement.

Description

Technical Field

[0001] This invention relates to the technical field of station platform clearance measurement, and more particularly to a method for evaluating the measurement error of station platform clearance. Background Technology

[0002] In railway transportation, platform clearance refers to the fixed distance between the rails and the platform. A certain distance must exist between the edge of the platform and the centerline of the tracks to prevent trains from contacting the platform while traveling on straight or curved tracks, ensuring safe train passage. To ensure safe train operation upon entering the station, clearance checks are conducted at least once per quarter. Furthermore, in the event of changes affecting the clearance (such as construction, platform deformation, or settlement), measurements should be taken immediately. Any violations should be addressed promptly to ensure safe train operation.

[0003] Currently, railway construction departments mostly use handheld tools to measure various parameters of platform clearance, but this method is inefficient, limited to fixed-point measurements at individual cross-sections, and susceptible to errors due to human factors. While existing technologies utilize measuring trolleys for static measurements of platform clearance parameters, sensor readings are also prone to error due to variations in ambient temperature. Furthermore, current technologies lack corresponding methods for assessing the accuracy of measurements of relevant platform clearance dimensions. Summary of the Invention

[0004] To address the above shortcomings, this invention proposes a method for evaluating the measurement error of platform clearance, which can evaluate the relevant parameters of the platform clearance dimensions, thereby ensuring the accuracy and reliability of the measurement.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for evaluating the measurement error of platform clearance includes:

[0007] Step 1: Measure the parameter values ​​of the clearance dimensions of the platform using a measuring trolley;

[0008] Step 2: Substitute the parameter values ​​obtained in Step 1 into the corresponding clearance dimension formula and calculate the value of the corresponding clearance dimension;

[0009] Step 3: Move the measuring trolley and repeat the measurement multiple times within a given unit step length, and record the data;

[0010] Step 4: Establish a measurement model, calculate the uncertainty of each component of the measurement model, and calculate the total combined standard uncertainty u. ci And calculate the expanded uncertainty U.

[0011] U = u ci×k, where k is the coverage factor and i is the dimension number;

[0012] Step 5: Compare the value of U calculated in Step 4 with the half-width value of the maximum permissible error range of the corresponding clearance dimension. If the calculated value of U is less than the half-width value, the measured clearance dimension parameter can be judged to be qualified.

[0013] The platform clearance measurement error assessment method according to embodiments of the present invention has at least the following beneficial effects: by measuring the parameter values ​​of each clearance dimension, then by establishing a measurement model for the corresponding clearance dimension, and calculating the components of the uncertainty of each clearance dimension, the expanded uncertainty of the corresponding clearance dimension is finally calculated. By comparing the expanded uncertainty with the half-width value of the maximum permissible error interval of the clearance dimension, it is beneficial to assess whether the corresponding measurement values ​​are qualified, thereby ensuring the accuracy and reliability of clearance dimension measurement and facilitating the formation of a standardized assessment process for platform clearance dimension measurement.

[0014] Furthermore, the measuring trolley includes running wheels and a crossbeam. The running wheels are used to roll in contact with the track. Displacement sensors and measuring wheels are respectively provided at both ends of the crossbeam. The measuring wheels are in contact with the inner wall of the track. The displacement sensors are used to obtain the distance l1 between the end point of the crossbeam and the contact point.

[0015] The clearance dimension formula in step 2 is used to calculate the track gauge L1.

[0016] L1 = l3 + 2 × l1, where l3 is the length of the beam;

[0017] u in step 3 ci Including the combined standard uncertainty u of the track gauge calculation c1 ,

[0018]

[0019] Where c1 to c7 are sensitivity coefficients, u 11 Uncertainty introduced for the repeatability or measurement resolution of gauge measurement, u 12 The uncertainty introduced by the measurement indication error of the displacement sensor, u 13 The uncertainty introduced by the effective height deviation between the contact point and the lowest generatrix of the traveling wheel, u 14 The uncertainty introduced by the flatness of the running wheels, u 15 The uncertainty introduced by the wear of the measuring wheel, u 16 The uncertainty introduced by the runout of the working surface of the measuring wheel on its own axis, u 17 The uncertainty is introduced by the difference in the coefficient of thermal expansion between the sleepers of the track and the measuring structure of the measuring trolley.

[0020] Furthermore, the uncertainty u introduced by the repeatability of track gauge measurement is calculated based on Type A analysis. a The uncertainty u introduced by the track gauge measurement resolution is calculated based on type B analysis. b , then u 11 =max[u a ,u b ];

[0021] Calculate u a The steps include: recording the data values ​​L obtained by measuring n sets of experimental data. i And calculate the average value of the data. The experimental standard deviation s is obtained by calculating the average value using the Bessel formula. i (L), u a =s i (L), as shown in the following formula:

[0022]

[0023] Calculate u b The steps include: Where a is the half-width value of the allowable error for measurement and calculation accuracy, and k is the coverage factor.

[0024] Furthermore, u is calculated based on class B analysis. 12 to u 17 As shown in the following formula:

[0025] Where i is the index of each uncertainty, a i is the half-width value of the allowable error for the measurement accuracy of the corresponding serial number, and k is the coverage factor.

[0026] Furthermore, the measuring trolley also includes a vertical rod, on which two laser ranging modules are spaced apart. The laser ranging modules and the measuring wheel are located on the same vertical plane. The laser ranging modules are used to measure the distance l4 from the laser starting point to the platform.

[0027] The clearance dimension formula in step 2 also includes calculating the clearance lateral dimension L2.

[0028] In the formula, l5 is the distance between the laser starting point and the contact point between the measuring wheel and the track;

[0029] u in step 3 ci It also includes calculating the combined standard uncertainty u of the lateral dimension of the limit. c3 ,

[0030]

[0031] Where c1 to c5 are sensitivity coefficients, u 31 Uncertainty introduced by the repeatability or measurement resolution of the clearance lateral dimension measurement, u 32 The uncertainty introduced by the measurement indication error of the laser ranging module, u 33 The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod, u 34 Uncertainty introduced for track gauge measurement, u 35 Uncertainty introduced for the perpendicularity of the vertical bar.

[0032] Furthermore, the measuring trolley also includes a tilt sensor, which is used to obtain the angle α between the top surface of the actual track and the horizontal plane;

[0033] The limit dimension formula in step 2 includes the theoretically calculated superelevation value H of the track.

[0034] H = 1505 × sin(α);

[0035] u in step 3 ci Including the extremely high combined standard uncertainty u of the calculated orbit c2 ,

[0036]

[0037] Where c1 to c4 are sensitivity coefficients, u 21 The maximum value of the uncertainty introduced for repeatability and measurement resolution in ultra-high-altitude measurements, u 22 The uncertainty introduced by the measurement indication error of the tilt sensor, u 23 The uncertainty introduced by the flatness of the running wheels, u 24 The standard uncertainty is introduced by the difference in the coefficient of thermal expansion between the sleepers of the track and the superelevation measurement structure of the measuring trolley track.

[0038] Furthermore, the measuring trolley also includes a vertical rod, on which two laser ranging modules are movably spaced. The laser ranging modules and the measuring wheel are located on the same vertical plane. The laser ranging modules are used to measure the distance l4 from the laser starting point to the platform. In step 1, the laser module performs a distance measurement on the edge of the platform once for each unit movement step, records the relevant data, and determines whether the laser hits the top surface of the platform exactly based on the data.

[0039] The limit dimension formula in step 2 also includes calculating the limit vertical dimension L3.

[0040] L3 = l6 + l7, where l6 is the travel distance of the laser module and l7 is the vertical height of the laser beam from the track surface.

[0041] Furthermore, if the track surface is level or the inner rail is too high, and the reading of the laser ranging module is 0mm or greater than 2000mm, then it is determined that the laser is just hitting the top surface of the platform.

[0042] If there is superelevation on the outer rail of the track, a calculated value T is introduced to determine whether the laser point hits the top surface of the platform exactly. If the value of T is greater than the threshold of 10, it is determined that the laser point hits the top surface of the platform exactly, as shown in the following formula:

[0043] Wherein, β2 is the current reading of the laser ranging module, β1 is the previous reading of the laser ranging module, and α is the unit movement step size of the laser ranging module.

[0044] Furthermore, the laser ranging module is connected to a slide module for driving it to move in the vertical direction, and the slide module includes a drive motor.

[0045] u in step 3 ci It also includes calculating the limit vertical dimensional uncertainty u. c4 ,

[0046]

[0047] Where c1 to c5 are sensitivity coefficients, u 41 Uncertainty introduced by the repeatability and / or measurement resolution of the platform clearance vertical dimension measurement, u 42 The uncertainty introduced by the indication error of the drive motor, u 43 The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod, u 44 The uncertainty introduced by the perpendicularity of the vertical rod, u 44 Uncertainty introduced by the difference in the expansion coefficients of the platform and the vertical rod.

[0048] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0049] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0050] Figure 1 This is a schematic diagram of a platform without superelevation in a platform clearance measurement error assessment method according to the present invention.

[0051] Figure 2 for Figure 1The middle platform has an ultra-high structural diagram.

[0052] In the diagram: Platform 100, Track 200. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0054] In the description of this invention, it should be noted that the terms "inner", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are only for the convenience of describing this invention 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 limiting this invention.

[0055] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0056] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0057] See Figure 1 and Figure 2 A method for evaluating the measurement error of platform clearance, comprising:

[0058] Step 1: Measure the parameter values ​​of each clearance dimension of platform 100 using a measuring trolley;

[0059] Step 2: Substitute the parameter values ​​obtained in Step 1 into the corresponding limit dimension formula and calculate the value of the corresponding limit dimension;

[0060] Step 3: Move the measuring trolley, repeat the measurement multiple times within a given step length, and record the data;

[0061] Step 4: Establish a measurement model, calculate the uncertainty of each component of the measurement model, and calculate the total combined standard uncertainty u. ci And calculate the expanded uncertainty U.

[0062] U = u ci ×k, where k is the coverage factor and i is the sequence number of each boundary dimension;

[0063] Step 5: Compare the value of U calculated in Step 4 with the half-width value of the maximum permissible error range of the corresponding clearance dimension. If the calculated value of U is less than the half-width value, the measured clearance dimension parameter can be judged to be qualified.

[0064] The above steps of the platform clearance measurement error assessment method involve measuring the parameter values ​​of each clearance dimension, establishing a corresponding clearance dimension measurement model, calculating the uncertainty components of each clearance dimension, and finally calculating the expanded uncertainty of the corresponding clearance dimension. By comparing the expanded uncertainty with the half-width of the maximum permissible error interval of the clearance dimension, it is helpful to assess whether the corresponding measurement values ​​are qualified, thereby ensuring the accuracy and reliability of clearance dimension measurement and facilitating the formation of a standardized assessment process for platform 100 clearance dimension measurement.

[0065] Furthermore, the measuring trolley includes running wheels and a crossbeam. The running wheels are used to roll in contact with the track 200. Displacement sensors and measuring wheels are respectively provided at both ends of the crossbeam. The measuring wheels are in contact with the inner wall of the track 200. The displacement sensors are used to obtain the distance l1 between the end point of the crossbeam and the contact point.

[0066] The clearance dimension formula in step 2 is used to calculate the track gauge L1 of track 200.

[0067] L1 = l3 + 2 × l1, where l3 is the length of the beam;

[0068] u in step 3 c i includes the combined standard uncertainty of the calculated track gauge. c1 ,

[0069]

[0070] Where c1 to c7 are sensitivity coefficients, u 11 Uncertainty introduced for the repeatability or measurement resolution of gauge measurement, u 12 The uncertainty introduced by the measurement indication error of the displacement sensor, u 13 The uncertainty introduced by the effective height deviation between the contact point and the lowest generatrix of the traveling wheel, u 14 Uncertainty introduced by the flatness of the running wheels, u 15Uncertainty introduced for measuring wheel wear, u 16 The uncertainty introduced by the runout of the working surface of the measuring wheel on its own axis, u 17 Uncertainty introduced by the difference in the coefficient of thermal expansion between the sleepers of track 200 and the measuring structural components of the measuring trolley.

[0071] Specifically, the structure of the measuring trolley involved in this application can be found in publication number CN 216206049 U, which discloses a platform building clearance laser measuring instrument. The rolling contact between the traveling wheels and the track 200 improves the smoothness of the measuring trolley's movement. The track gauge measurement model is established considering u... 11 to u 17 The deviations involved in the corresponding situations have been fully considered, taking into account the errors caused by related components, thereby better evaluating the accuracy and reliability of the track gauge measurement values. The displacement sensor is existing technology and will not be described in detail.

[0072] Furthermore, the uncertainty u introduced by the repeatability of track gauge measurement is calculated based on Type A analysis. a The uncertainty u introduced by the track gauge measurement resolution is calculated based on type B analysis. b , then u 11 =max[u a ,u b ];

[0073] Calculate u a The steps include: recording the data values ​​L obtained by measuring n sets of experimental data. i And calculate the average value of the data. The experimental standard deviation s is obtained by calculating the average value using Bessel's formula. i (L), u a =s i (L), as shown in the following formula:

[0074]

[0075] Calculate u b The steps include: Where a is the half-width value of the allowable error for measurement and calculation accuracy, and k is the coverage factor.

[0076] Furthermore, u is calculated based on class B analysis. 12 to u 17 As shown in the following formula:

[0077] Where i is the index of each uncertainty, a i is the half-width value of the allowable error for the measurement accuracy of the corresponding serial number, and k is the coverage factor.

[0078] Specifically, in the uncertainty analysis of track gauge measurement, the track gauge was first measured 10 times under repeatability conditions using a measuring trolley, and the data in the following table were obtained:

[0079] n (number of times) 1 2 3 4 5 6 7 8 9 10 <![CDATA[L1(mm)]]> 1435.0 1435.1 1435.0 1435.0 1435.1 1435.0 1435.0 1435.1 1435.1 1435.0

[0080] Calculate u a Then substitute the data into s. i (L), the experimental standard deviation of the track gauge s1(L) = 0.01 mm is obtained, then u a =s1(L)=0.0516mm.

[0081] Calculate u b Since the measuring carriage has a resolution of 0.1, then a = 0.05 mm. Assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can see that: Then u a Greater than u b Therefore, the uncertainty introduced by the resolution is negligible, then u 11 =u a =0.0516mm.

[0082] Calculate u 12 Since the maximum indication error of the displacement sensor on the measuring trolley is ±0.05mm, then a = 0.05mm. There are two displacement sensors, assumed to follow a uniform distribution. The coverage factor is... From the corresponding formula, we can obtain

[0083] Calculate u 13 Since the effective height of the gauge measurement point from the lowest generatrix of the running wheel is 16mm ± 0.20mm, and the maximum permissible error is ± 0.20mm, then a = 0.05mm. Assuming a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0084] Calculate u 14 Since the working generatrices of all traveling wheels should be in the same plane, and the flatness should not exceed 0.2mm, assuming uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0085] Calculate u 15 Since the diameter variation of the measuring wheel should not exceed 0.20 mm within its permissible lifespan, and the measuring carriage has two measuring wheels, assuming they follow a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0086] Calculate u 16 Since the runout of the measuring wheel's working surface on its own axis of rotation should not exceed 0.10 mm, and the measuring carriage has two measuring wheels, assuming they follow a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0087] Calculate u 17 The coefficient of thermal expansion of the sleepers for track 200 is α2 = 11.5 × 10⁻⁶. -6 / ℃, the track gauge measuring structure of the measuring trolley is made of 304 stainless steel, with a corresponding coefficient of thermal expansion α1=17.2×10 -6 / ℃, in actual measurement, there is a certain temperature difference between the sleeper and the gauge, and it falls at any point within the estimated range (-3~3)℃ with equal probability, that is, the half-width a is 1435×(17.2-11.5)×10 -6 ×3=0.0245mm, assuming a triangular distribution, the coverage factor is... From the corresponding formula, we get

[0088] Calculate u c1 : Among them, c1 to c7 take values ​​of 1, and finally u is calculated. c1 = 0.1986 mm.

[0089] Calculate the expanded uncertainty of the track gauge: U = u ci ×k, where k takes the value of 2, and calculate U = 0.1986 × 2 = 0.3971 mm.

[0090] Calculation conclusion: Since the maximum permissible error of the track gauge of the measuring trolley is ±0.5mm, the expanded uncertainty of the track gauge measurement of the clearance trolley should not be greater than the half-width of the maximum permissible error interval, i.e., 0.5mm. Therefore, the track gauge measurement of the measuring trolley, U = 0.3971mm, is less than 0.5mm, which meets the measurement requirements.

[0091] See Figure 1 and Figure 2 Furthermore, the measuring trolley also includes a vertical rod, on which two laser ranging modules are spaced apart. The laser ranging modules and the measuring wheel are located on the same vertical plane. The laser ranging modules are used to measure the distance l4 from the laser starting point to the platform 100.

[0092] Step 2 of the clearance dimension formula also includes calculating the clearance lateral dimension L2.

[0093] In the formula, l5 is the distance between the laser starting point and the contact point between the measuring wheel and the track 200;

[0094] u in step 3 ci also includes calculating the combined standard uncertainty of the lateral dimension of the clearance. c3 ,

[0095]

[0096] Where c1 to c5 are sensitivity coefficients, u 31 Uncertainty introduced for the repeatability and / or measurement resolution of the clearance lateral dimension measurement, u 32 The uncertainty introduced by the measurement indication error of the laser ranging module, u 33 The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod, u 34 Uncertainty introduced for track gauge measurement, u 35 Uncertainty introduced for the perpendicularity of the vertical bar.

[0097] Specifically, the measurement model for the lateral dimension of the clearance considers u 31 to u 35 The deviations involved in the corresponding situations have been fully considered, taking into account the errors caused by related components, thereby better assessing the accuracy of the measured values ​​of the clearance lateral dimensions. The laser ranging module is existing technology and will not be described in detail.

[0098] When performing uncertainty analysis on the measurement of the clearance lateral dimension, the specific calculation process is analogous to the calculation and analysis steps of the track gauge. First, the track gauge is measured 10 times under repeatability conditions using a measuring trolley, and the data in the following table is obtained.

[0099] n (number of times) 1 2 3 4 5 6 7 8 9 10 <![CDATA[L2(mm)]]> 1800.0 1800.1 1800.0 1800.0 1800.0 1800.1 1800.0 1800.1 1800.1 1800.0

[0100] Calculate the uncertainty u introduced by the repeatability of the lateral dimension measurement of the clearance. a1 Then substitute the data into s. i (L), the experimental standard deviation of the boundary lateral dimension is obtained as s2(L) = 0.0882 mm, then u a1 =s2(L)=0.0882mm.

[0101] Calculate the uncertainty u introduced by the resolution of the lateral dimension measurement of the clearance. b1 Since the measuring carriage has a resolution of 0.1, then a = 0.05 mm. Assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can see that: Due to u a1 Greater than u b1 Therefore, the uncertainty introduced by the resolution is negligible, then u 31 =u a1 =0.0882mm.

[0102] Calculate u 32Since the maximum indication error of the laser ranging module is ±1mm, assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0103] Calculate u 33 Since the perpendicularity between the laser module and the vertical rod is no greater than 0.05mm, assuming a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0104] Calculate u 34 Since the expanded uncertainty of track gauge measurement is U = 0.3971 mm, the uncertainty u introduced by track gauge measurement... 34 =0.3971 / 2 =0.1986mm.

[0105] Calculate u 35 Since the verticality of the clearance trolley's vertical rod is no greater than 0.05mm, it is assumed to follow a uniform distribution, with a coverage factor of... From the corresponding formula, we can obtain

[0106] Calculate u c3 : Among them, c1 to c5 take values ​​of 1, and finally u is calculated. c2 = 0.6109 mm.

[0107] Calculate the expanded uncertainty of the clearance lateral dimension: U = u ci ×k, where k takes the value of 2, and calculate U = 0.6109 × 2 = 1.2218 mm.

[0108] Calculation conclusion: Since the maximum permissible error of the lateral dimension of the measuring trolley is -3 to 0 mm, the expanded uncertainty of the lateral dimension of the measuring trolley should not be greater than the half-width of the maximum permissible error interval, i.e., 1.5 mm. Therefore, the track gauge measurement of the measuring trolley, U = 1.2218 mm, is less than 1.5 mm, which meets the measurement requirements.

[0109] Furthermore, the measuring trolley also includes a tilt sensor, which is used to obtain the angle α between the top surface of the actual track 200 and the horizontal plane;

[0110] The limit dimension formula in step 2 includes the theoretically calculated superelevation value H of track 200.

[0111] H = 1505 × sin(α);

[0112] u in step 3 ci Including the extremely high combined standard uncertainty u of orbit 200 c2 ,

[0113]

[0114] Where c1 to c4 are sensitivity coefficients, u 21 Uncertainty introduced for the repeatability or measurement resolution of ultra-high-speed measurements, u 22 The uncertainty introduced by the measurement indication error of the tilt sensor, u 23 Uncertainty introduced by the flatness of the running wheels, u 24 The standard uncertainty is introduced by the difference in the coefficient of thermal expansion between the sleepers of track 200 and the ultra-high-altitude measurement structure of the measuring trolley rail.

[0115] Specifically, the Orbit 200 ultra-high-altitude measurement model considers u 21 to u 24 The deviations involved fully consider the errors caused by related components, thereby better assessing the accuracy of the track gauge measurement values. The laser ranging module is existing technology and will not be described in detail.

[0116] When performing uncertainty analysis on the superelevation measurement of track 200, the specific calculation process is analogous to the calculation and analysis steps of track gauge. First, the track gauge is measured 10 times under repeatability conditions using a measuring trolley, and the data in the following table are obtained.

[0117] n (number of times) 1 2 3 4 5 6 7 8 9 10 H(mm) 49.9 50.0 49.9 50.0 49.9 50.0 49.9 50.0 50.0 50.0

[0118] Calculate the uncertainty u introduced by the repeatability of ultra-high-altitude measurements. a2 Then substitute the data into s. i (L), the experimental standard deviation of the ultra-high dimension is obtained as s3(L) = 0.0516 mm, then u a2 =s3(L)=0.0516mm.

[0119] Calculate the uncertainty u introduced by the repeatability of ultra-high dimension measurement resolution. b2 Since the measuring carriage has a resolution of 0.1, then a = 0.05 mm. Assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can see that: Due to u a2 Greater than u b2 Therefore, the uncertainty introduced by the resolution is negligible, then u 21 =u a2 =0.0516mm.

[0120] Calculate u 22 Since the maximum indication error of the laser ranging module is ±0.003°, and the half-width is 1505×sin(0.003 / 180×π)=0.0788mm, assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0121] Calculate u 23 Since the working generatrices of all traveling wheels should be in the same plane, their flatness should not exceed 0.2mm. Assuming a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0122] Calculate u 24 Because the coefficient of thermal expansion of the sleepers on track 200 is α2 = 11.5 × 10⁻⁶. -6 / ℃, the ultra-high measurement structure of the measuring trolley is made of 304 stainless steel, with a corresponding coefficient of thermal expansion α1=17.2×10 -6 / ℃, in actual measurements, there is a certain temperature difference between the sleeper and the gauge, and it falls at any point within the estimated range (-3~3)℃ with equal probability, that is, the half-width a is 100×(17.2-11.5)×10 -6 ×3=0.0017mm, assuming a triangular distribution, the coverage factor is... From the corresponding formula, we get

[0123] Calculate u c2 : Among them, c1 to c4 take values ​​of 1, and finally u is calculated. c2 =0.0869mm.

[0124] Calculate the expanded uncertainty of ultra-high: U = u ci ×k, where k takes the value of 2, and calculate U = 0.0869 × 2 = 0.1738 mm.

[0125] Calculation conclusion: Since the maximum permissible error of the superelevation measurement of the measuring trolley is ±1mm, the expanded uncertainty of the superelevation measurement of the measuring trolley should not be greater than the half-width of the maximum permissible error interval, i.e., 1mm. Therefore, the track gauge measurement of the measuring trolley, U = 0.1738mm, is less than 1mm, which meets the measurement requirements.

[0126] See Figure 1 and Figure 2 Furthermore, the measuring trolley also includes a vertical rod, on which two laser ranging modules are movably and spaced apart. The laser ranging modules and the measuring wheel are located on the same vertical plane. The laser ranging modules are used to measure the distance l4 from the laser starting point to the platform 100. In step 1, the laser module performs a distance measurement on the edge of the platform 100 once for each unit of movement, records the relevant data, and determines whether the laser hits the top surface of the platform 100 based on the data.

[0127] Step 2 of the clearance dimension formula also includes calculating the clearance vertical dimension L3.

[0128] L3 = l6 + l7, where l6 is the travel distance of the laser module and l7 is the vertical height of the laser from the track surface at 200.

[0129] Furthermore, if the rail surface of track 200 is level or the inner rail is too high, and the reading of the laser ranging module is 0mm or greater than 2000mm, then it is determined that the laser is hitting the top surface of platform 100.

[0130] If superelevation occurs on the outer rail of track 200, a calculated value T is introduced to determine whether the laser point hits the top surface of platform 100 exactly. If the value of T is greater than the threshold of 10, it is determined that the laser point hits the top surface of platform 100 exactly, as shown in the following formula:

[0131] Where β2 is the current reading of the laser ranging module, β1 is the previous reading of the laser ranging module, and α is the unit movement step size of the laser ranging module.

[0132] Furthermore, the laser ranging module is connected to a slide module for driving it to move in the vertical direction, and the slide module includes a drive motor;

[0133] u in step 3 ci It also includes calculating the limit vertical dimensional uncertainty u. c4 ,

[0134]

[0135] Where c1 to c5 are sensitivity coefficients, u 41 Uncertainty introduced for the repeatability or measurement resolution of limit vertical dimension measurements, u 42 The uncertainty introduced by the indication error of the drive motor, u 43 The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod, u 44 The uncertainty introduced by the perpendicularity of the vertical rod, u 44 Uncertainty introduced by the difference in the expansion coefficients of platform 100 and the vertical rod.

[0136] Specifically, the measurement model for the vertical dimension of the clearance considers u 41 to u 45 The deviations involved fully consider the errors caused by related components, thereby better assessing the accuracy of the measured values ​​of the clearance vertical dimensions. The laser ranging module and the slide module are existing technologies and will not be described in detail.

[0137] When performing uncertainty analysis on the vertical dimension measurement of the clearance, the specific calculation process is analogous to the calculation and analysis steps of the track gauge. First, the measurement trolley is used to perform 10 measurement parameters under repeatability conditions, and the data in the following table are obtained.

[0138]

[0139] Calculate the uncertainty u introduced by the repeatability of the clearance vertical dimension measurement. a3 Then substitute the data into s. i (L), the experimental standard deviation of the limit vertical dimension is obtained as s4(L) = 0.0483 mm, then u a3 =s4(L)=0.0483mm.

[0140] Calculate the uncertainty u introduced by the resolution of the limit vertical dimension measurement. b2 Since the measuring carriage has a resolution of 0.1, then a = 0.05 mm. Assuming it follows a uniform distribution, the coverage factor is... From the corresponding formula, we can see that: Due to u a2 Greater than u b2 Therefore, the uncertainty introduced by the resolution is negligible, then u 41 =u a2 =0.0483mm.

[0141] Calculate u 42 Since the maximum indication error of the drive motor is ±0.05°, its half-width formula is: Where Y is the calculated moving distance of the laser ranging module, n is the rotation angle of the drive motor, and R is the radius of the drive gear of the slide module. The calculated value is Y = 0.0262 mm. Assuming a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0142]

[0143] Calculate u 43 It can be seen that the perpendicularity between the laser module and the vertical rod is no greater than 0.05mm. Assuming a uniform distribution, the coverage factor is... From the corresponding formula, we can obtain

[0144] Calculate u 44 It can be determined that the perpendicularity of the measuring trolley's vertical rod is no greater than 0.05 mm. Assuming a uniform distribution, the coverage factor is given. From the corresponding formula, we can obtain

[0145] Calculate u 45Because the coefficient of thermal expansion of the sleepers on track 200 is α2 = 11.5 × 10⁻⁶. -6 / ℃, the vertical rod is made of aluminum alloy, and its corresponding coefficient of thermal expansion α1=22.6×10 -6 / ℃, in actual measurements, there is a certain temperature difference between the sleeper and the gauge, and it falls at any point within the estimated range (-3~3)℃ with equal probability, that is, the half-width a is 1350×(22.6-11.5)×10 -6 ×3=0.045mm, assuming a triangular distribution, the coverage factor is... From the corresponding formula, we get

[0146] Calculate u c4 : Among them, c1 to c5 take values ​​of 1, and finally u is calculated. c4 =0.0576mm.

[0147] Calculate the expanded uncertainty of ultra-high: U = u ci ×k, where k takes the value of 2, and calculate U = 0.0576 × 2 = 0.1152 mm.

[0148] Calculation conclusion: Since the maximum permissible error of the measuring trolley's measuring limit vertical dimension is 2 to 0 mm, the expanded uncertainty of the measuring trolley's measuring limit vertical dimension should not be greater than the half-width of the maximum permissible error interval, i.e., 1 mm. Therefore, the measuring trolley's limit dimension measurement U = 0.1152 mm is less than 1 mm, which meets the measurement requirements.

[0149] Through the above steps, the clearance dimensions of the platform (including track gauge, superelevation, clearance lateral dimensions, and clearance vertical dimensions) can be correctly evaluated, which helps to improve the accuracy and reliability of measurement data, thus forming a standardized evaluation process for the measurement of clearance dimensions of the platform.

[0150] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0151] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for evaluating the measurement error of platform clearance, characterized in that, include: Step 1: Use the measuring trolley to measure the parameter values ​​of each limit dimension of the platform (100); Step 2: Substitute the parameter values ​​obtained in Step 1 into the corresponding clearance dimension formula and calculate the value of the corresponding clearance dimension; Step 3: Move the measuring trolley and repeat the measurement multiple times within a given unit step length, and record the data; Step 4: Establish a measurement model, calculate the uncertainty of each component of the measurement model, and calculate the total combined standard uncertainty. And calculate the expanded uncertainty. , ,in, The inclusion factor is i, where i is the index of each boundary dimension. Step 5: Calculate the following in Step 4: The value is compared with the half-width value of the maximum permissible error range of the corresponding clearance dimension. If If the calculated value is less than the half-width value, then the measured clearance dimension parameter can be judged to be qualified; The measuring trolley includes running wheels and a crossbeam. The running wheels are used for rolling contact with the track (200). Displacement sensors and measuring wheels are respectively provided at both ends of the crossbeam. The measuring wheels are in contact with the inner wall of the track (200). The displacement sensors are used to obtain the distance between the end point of the crossbeam and the contact point. ; The track gauge is calculated using the clearance dimension formula in step 2. , ,in, This is the length of the beam; In step 3 Includes the combined standard uncertainty of the track gauge. , ， in, to This is the sensitivity coefficient. Uncertainty introduced for the repeatability or measurement resolution of track gauge measurements. The uncertainty introduced by the measurement indication error of the displacement sensor, The uncertainty introduced by the effective height deviation between the contact point and the lowest generatrix of the traveling wheel. The uncertainty introduced by the flatness of the running wheels, Uncertainty introduced by the wear of the measuring wheel, The uncertainty introduced by the runout of the working surface of the measuring wheel on its own axis. Uncertainty introduced by the difference in the coefficient of thermal expansion between the sleepers of the track (200) and the measuring structure of the measuring trolley; The measuring trolley also includes a vertical rod, on which two laser ranging modules are spaced apart. The laser ranging modules and the measuring wheel are located on the same vertical plane. The laser ranging modules are used to measure the distance from the laser starting point to the platform (100). ; The clearance dimension formula in step 2 also includes calculating the clearance lateral dimension. , In the formula, The distance between the laser starting point and the contact point between the measuring wheel and the track (200); In step 3 It also includes calculating the combined standard uncertainty of the lateral dimension of the limit. , ， in, to This is the sensitivity coefficient. Uncertainty introduced for the repeatability or measurement resolution of clearance lateral dimension measurements. The uncertainty introduced by the measurement indication error of the laser ranging module, The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod. Uncertainty introduced for track gauge measurement, Uncertainty introduced for the perpendicularity of the vertical bar.

2. The method for evaluating the measurement error of platform clearance according to claim 1, characterized in that, include: Uncertainty introduced by repeatability in gauge measurement based on Type A analysis. Uncertainty introduced by track gauge measurement resolution based on Type B analysis. ,but ; calculate The steps include: recording the data values ​​obtained by measuring n sets of experimental data. And calculate the average value of the data. The experimental standard deviation is obtained by calculating the average value using the Bessel formula. , As shown in the following formula: ； calculate The steps include: ,in, The half-width value is used to measure the allowable error in the accuracy of the calculation. It is a inclusion factor.

3. The method for evaluating the measurement error of platform clearance according to claim 1, characterized in that, include: Based on B-type analysis and calculation to As shown in the following formula: Where i is the index of each uncertainty, This is the half-width value representing the allowable error for the accuracy calculation of the corresponding serial number. It is a inclusion factor.

4. The method for evaluating the measurement error of platform clearance according to claim 1, characterized in that, include: The measuring trolley also includes a tilt sensor, which is used to obtain the angle between the top surface of the actual track (200) and the horizontal plane. ; The limit dimension formula in step 2 includes the theoretically calculated superelevation value of the track (200). , ； In step 3 Including the extremely high combined standard uncertainty of the calculated orbit (200) , ， in, to This is the sensitivity coefficient. Uncertainty introduced for the repeatability or measurement resolution of ultra-high-speed measurements. The uncertainty introduced by the measurement indication error of the tilt sensor, The uncertainty introduced by the flatness of the running wheels, The standard uncertainty is introduced by the difference in the coefficient of thermal expansion between the sleepers of the track (200) and the ultra-high measurement structure of the measuring trolley track.

5. The method for evaluating the measurement error of platform clearance according to claim 1, characterized in that, include: The measuring trolley also includes a vertical rod, on which two laser ranging modules are movably spaced. The laser ranging modules are located on the same vertical plane as the measuring wheel, and are used to measure the distance from the laser starting point to the platform (100). In step 1, the laser ranging module measures the distance to the edge of the platform (100) once for each unit step length, records the relevant data, and determines whether the laser hits the top surface of the platform (100) based on the data. The limit dimension formula in step 2 also includes calculating the vertical dimension of the limit. , ,in, The distance traveled by the laser ranging module. The vertical height of the laser beam to the track surface.

6. The method for evaluating the measurement error of platform clearance according to claim 5, characterized in that, include: If the track surface of the track (200) is horizontal or the inner track is too high, and the reading of the laser ranging module is 0mm or greater than 2000mm, then it is determined that the laser just hits the top surface of the platform (100). If there is superelevation on the outer rail of track (200), a calculated value T is introduced to determine whether the laser point hits the top surface of platform (100). If the value of T is greater than the threshold of 10, it is determined that the laser point hits the top surface of platform (100), as shown in the following formula: ,in, This is the reading from the laser ranging module currently described. This is the reading from the laser ranging module mentioned last time. This is the unit movement step size of the laser ranging module.

7. The method for evaluating the measurement error of platform clearance according to claim 5, characterized in that, include: The laser ranging module is connected to a slide module for driving it to move in the vertical direction, and the slide module includes a drive motor. In step 3 It also includes calculating the uncertainty of the limit vertical dimensions. , ， in, to This is the sensitivity coefficient. Uncertainty introduced for the repeatability or measurement resolution of limit vertical dimension measurements. Uncertainty introduced by the indication error of the drive motor The uncertainty introduced by the perpendicularity of the laser ranging module to the vertical rod. The uncertainty introduced for the perpendicularity of the vertical rod. Uncertainty introduced by the difference in the expansion coefficients of the platform (100) and the vertical rod.

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