Method and system for determining surface emissivity of brake component and train

Abstract

The invention provides a method and system for determining the surface emissivity of a brake component and a train. Relates to the technical field of surface emissivity and rail trains. The method for determining the surface emissivity of the brake component comprises the following steps: determining a heating area for locally heating the brake component of a train; the heating area is heated through a heating piece, so that the local temperature of the braking component is increased, and the preset temperature distribution characteristic is met; measuring the temperature of at least part of the heating area by using an infrared thermometer, and calibrating the emissivity of the infrared thermometer in the temperature measurement process; and determining the calibrated emissivity as the surface emissivity of the braking component.

Description

Technical Field

[0001] The present disclosure relates to the technical field of surface emissivity measurement, and more particularly to a method, a system, and a train for determining the surface emissivity of a braking member. Background Art

[0002] Infrared thermometers have the advantages of fast response speed, non-contact, non-interference with the temperature field, and suitability for measurement in harsh environments. When using an infrared thermometer to measure the surface temperature of an object, the emissivity of the measured surface needs to be set in advance. The emissivity of the object surface is related to factors such as the material, texture, roughness, color, temperature of the object surface, and the relative position between the thermometer and the surface.

[0003] In the process of implementing the concept of the present disclosure, the inventors found that at least the following problems exist in the related art: If the wheels or brake discs of a vehicle are cut off and then the surface emissivity of the object is measured, the material, texture, roughness, temperature field, and working state of the surface of the cut sample may change, making it difficult to ensure the accuracy of emissivity measurement. Summary of the Invention

[0004] In view of this, the present disclosure provides a method, a system, and a train for determining the surface emissivity of a braking member.

[0005] One aspect of the present disclosure provides a method for determining the surface emissivity of a braking member, including: determining a heating area for locally heating the braking member of the train; heating the heating area with a heating sheet to increase the local temperature of the braking member and satisfy a predetermined temperature distribution characteristic; measuring the temperature of at least a part of the heating area with an infrared thermometer, and calibrating the emissivity of the infrared thermometer during the temperature measurement process; and determining the emissivity obtained by calibration as the surface emissivity of the braking member.

[0006] According to an embodiment of the present disclosure, the predetermined temperature distribution characteristic is that the difference between the surface temperature and the central temperature of the heating area is less than a predetermined threshold, and the surface temperature and the central temperature are within a predetermined temperature range.

[0007] According to an embodiment of the present disclosure, heating the heating area with a heating sheet includes: arranging at least one heating sheet in the heating area or in an extended heating area formed based on the heating area according to a target local heating method, where the extended heating area is an area extending around the heating area as the center; energizing at least one heating sheet to increase the temperature, and using the heating sheet with the increased temperature to conduct heat to the heating area.

[0008] According to an embodiment of the present disclosure, the method for determining the emissivity of the surface of the braking member further includes establishing N local heating simulation models based on N local heating methods for the heating region; using the N local heating simulation models to simulate the heating processes of the N local heating methods, and outputting the simulation results of the temperature distribution of the heating region corresponding to the N local heating methods; and determining the target local heating method from the N local heating methods based on the simulation results of the temperature distribution.

[0009] According to an embodiment of the present disclosure, the N local heating methods at least include: arranging a plurality of heating sheets in the first region surrounding the heating region within the extended heating region; arranging at least one heating sheet in the second region that completely covers the heating region within the extended heating region, where the area of the second region is equal to the area of the heating region; arranging at least one heating sheet in the second region that completely covers the heating region within the extended heating region, where the area of the second region is greater than the area of the heating region; and arranging at least one heating sheet in the second region that partially covers the heating region within the extended heating region.

[0010] According to an embodiment of the present disclosure, the braking member includes a wheel and / or a brake disc.

[0011] According to an embodiment of the present disclosure, calibrating the emissivity of the infrared thermometer includes: measuring the true temperature of at least a part of the region; measuring the first temperature of at least a part of the region based on the first emissivity set for the infrared thermometer; in the case where the first temperature and the true temperature do not meet the predetermined numerical conditions, adjusting the first emissivity to the second emissivity, and completing the calibration of the emissivity of the infrared thermometer when the second temperature of at least a part of the region measured based on the second emissivity and the true temperature meet the predetermined numerical conditions, where the second emissivity is the calibrated emissivity.

[0012] According to an embodiment of the present disclosure, determining the heating region for locally heating the braking member of the train includes: determining the temperature measurement region on the surface of the braking member; and determining the heating region based on the temperature measurement region.

[0013] According to an embodiment of the present disclosure, determining the temperature measurement region on the surface of the braking member includes: determining the temperature measurement region on the surface of the braking member based on the installation position of the infrared thermometer installed near the braking member.

[0014] According to an embodiment of the present disclosure, determining the temperature measurement region on the surface of the braking member based on the installation position of the infrared thermometer installed near the braking member includes: determining the center point based on the intersection point of the extension line of the detection head of the infrared thermometer along the detection direction on the surface of the braking member; determining the measurement radius according to the straight-line distance between the detection head and the center point; and determining the temperature measurement region based on the center point and the measurement radius.

[0015] Another aspect of the present disclosure provides a system for determining the emissivity of a braking member surface, including: a first determination module for determining a heating area for locally heating the braking member of the train. A heating module for heating the heating area by using a heating sheet to increase the local temperature of the braking member and meet a predetermined temperature distribution characteristic. A calibration module for measuring the temperature of at least a part of the heating area by using an infrared thermometer, and calibrating the emissivity of the infrared thermometer during the temperature measurement process. A second determination module for determining the emissivity obtained by calibration as the surface emissivity of the braking member.

[0016] Another aspect of the present disclosure provides a train, including: a vehicle body; a braking member and a system for determining the surface emissivity of the braking member.

[0017] According to an embodiment of the present disclosure, by directly measuring the braking member on the train, destructive behaviors such as cutting objects are avoided. It not only maintains the integrity and original working state of the braking member, but also can directly obtain the temperature and emissivity information during actual operation, ensuring that the measurement results accurately and real-time reflect the true characteristics of the braking member. Compared with the measurement method of cutting the braking member in the related art, the convenience and efficiency of the measurement are improved, and the normal operation rhythm of the train is not affected. In addition, since the braking member in the train is large in volume, although heating it as a whole can meet the test requirements, the heating difficulty is large and the cost is high. On the premise of meeting the test requirements of emissivity calibration, the method of implementing local heating can reduce the operation difficulty. At the same time, by reasonably designing the heating sheet, the temperature distribution of the heating area can be precisely controlled to meet the predetermined temperature distribution characteristic, enabling the braking member to reach a more stable and uniform temperature distribution state, which is beneficial to accurately determining the temperature measurement area, avoiding temperature measurement errors caused by uneven temperature, and improving the accuracy of emissivity calibration. At the same time, it is beneficial to simulate the temperature change on the surface of the braking member under different braking conditions. Compared with the method of heating an object by cutting it or heating the entire wheel or brake disc in the related art, the application scenario of measuring the surface emissivity is broadened. Description of the Drawings

[0018] Through the following description of the embodiments of the present disclosure with reference to the drawings, the above and other objects, features and advantages of the present disclosure will become clearer. In the drawings:

[0019] Figure 1 Schematically shows a schematic diagram of a method for determining the surface emissivity of a braking member according to an embodiment of the present disclosure;

[0020] Figure 2 Schematically shows a flowchart of a method for determining the surface emissivity of a braking member according to an embodiment of the present disclosure;

[0021] Figure 3Schematically shows a schematic diagram of the positional relationship between the temperature measurement area and the heating area according to an embodiment of the present disclosure;

[0022] Figure 4 Schematically shows a schematic diagram of the positional relationship between the heating area and the extended heating area according to an embodiment of the present disclosure;

[0023] Figures 5A - 5E Schematically shows schematic diagrams of five local heating methods according to an embodiment of the present disclosure;

[0024] Figure 6A Schematically shows a simulation schematic diagram of locally heating a wheel using one local heating method according to an embodiment of the present disclosure;

[0025] Figure 6B Schematically shows a temperature field distribution schematic diagram of locally heating a wheel using one local heating method according to an embodiment of the present disclosure;

[0026] Figure 7A Schematically shows a simulation schematic diagram of locally heating a wheel using another local heating method according to an embodiment of the present disclosure;

[0027] Figure 7B Schematically shows a temperature field distribution schematic diagram of locally heating a wheel using another local heating method according to an embodiment of the present disclosure;

[0028] Figure 8 Schematically shows a scene schematic diagram of measuring the true temperature of the temperature measurement area using a surface thermometer according to an embodiment of the present disclosure. Detailed implementation manners

[0029] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure.

[0030] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0031] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0032] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning that those of ordinary skill in the art usually understand such expressions (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0033] In the embodiments of the present disclosure, in aspects such as the collection, update, analysis, processing, use, transmission, provision, disclosure, storage, etc. of the involved data (for example, including but not limited to user personal information), they all comply with the provisions of relevant laws and regulations, are used for legal purposes, and do not violate public order and good customs. In particular, necessary measures are taken for user personal information to prevent illegal access to user personal information data and to safeguard the security of user personal information, network security, and national security.

[0034] In the embodiments of the present disclosure, before obtaining or collecting user personal information, the authorization or consent of the user has been obtained.

[0035] An infrared thermometer measures temperature by receiving the infrared energy radiated by an object, but its accuracy highly depends on the accurate setting of the surface emissivity of the object being measured. However, the surface state of train braking components (such as wheels and brake discs) changes dynamically during actual operation due to oxidation, wear, or temperature changes. Traditional laboratory calibration or contact measurement methods are difficult to calibrate the emissivity in real time under complex working conditions, especially when facing high-speed rotation, static parameters will lead to significant errors.

[0036] When a fault occurs in a wheel or brake disc during the normal transportation process of a train, it is necessary to detect the performance of a single wheel or brake disc, simulate the heat absorption situation of a single component during actual operation, and quickly detect the thermal performance of the component. For trains that have been put into operation, it is difficult to cut samples from actual objects for fault detection. When a fault is found, an appropriate time should be selected to wait for the train to stop, and targeted fault troubleshooting should be carried out. Avoid causing other operation safety problems due to being in a high-intensity working state.

[0037] In view of this, embodiments of the present disclosure provide a method for determining the surface emissivity of a braking member, including: determining a heating area for locally heating the braking member of the train; using a heating sheet to heat the heating area so as to increase the local temperature of the braking member and satisfy a predetermined temperature distribution characteristic; using an infrared thermometer to measure the temperature of at least part of the heating area, and calibrating the emissivity of the infrared thermometer during the temperature measurement process; and determining the calibrated emissivity as the surface emissivity of the braking member.

[0038] Figure 1 FIG. schematically shows a schematic diagram of a method for determining the surface emissivity of a braking member according to an embodiment of the present disclosure. Figure 2 FIG. schematically shows a flowchart of a method for determining the surface emissivity of a braking member according to an embodiment of the present disclosure. The following will be described in conjunction with Figure 1 and Figure 2 the method for determining the surface emissivity of a braking member according to an embodiment of the present disclosure.

[0039] As Figure 1 shown, an infrared thermometer 101 is used to measure the wheel 102, and during installation, the detection head of the infrared thermometer 101 is oriented directly towards the wheel 102. When local heating of the wheel 102 is required, a heating sheet 103 installed on the wheel tread is used to locally heat it, and the infrared thermometer 101 is used to measure the temperature of the heated wheel 102 to achieve emissivity calibration.

[0040] As Figure 2 shown, the method for determining the surface emissivity of the braking member includes operations S210 to S240.

[0041] In operation S210, determine a heating area for locally heating the braking member of the train.

[0042] According to an embodiment of the present disclosure, the heating area for local heating can be any area on the braking member. As Figure 1 shown, the heating area for local heating is a part of the wheel tread. It can also be a part prone to failure or a key detection area, etc. For example, for a brake disc, a surface area that often rubs against the brake pad can be selected as the heating area.

[0043] In operation S220, use a heating sheet to heat the heating area so as to increase the local temperature of the braking member and satisfy a predetermined temperature distribution characteristic.

[0044] According to an embodiment of the present disclosure, a heating sheet is a heating device that converts electrical energy into heat energy by means of an electric current or the like. Since the curvature radius of the wheel tread is relatively large, multiple heating sheets (for example, constant-temperature ceramic PTC heating sheets) can be selected to contact the heating area, and they are adhered to the periphery of the tread temperature measurement area with high-temperature tape to locally heat the wheel.

[0045] According to an embodiment of the present disclosure, after determining the heating area, a heating sheet is used to heat the area, so that the local temperature of the braking member increases and satisfies a predetermined temperature distribution characteristic. The predetermined temperature distribution characteristic can make the temperature reach a certain range, or the temperature distribution in different parts conforms to a specific law, etc. For example, the overall temperature distribution on the surface of the brake disc is relatively uniform, and the temperature range is between 150 and 200 degrees Celsius (the specific temperature range can be preset according to factors such as the material characteristics of the brake disc and the operating conditions of the train).

[0046] In operation S230, an infrared thermometer is used to measure the temperature of at least part of the heating area, and during the temperature measurement process, the emissivity of the infrared thermometer is calibrated.

[0047] According to an embodiment of the present disclosure, an infrared thermometer is used to measure the temperature of the selected temperature measurement area, and the emissivity of the infrared thermometer is adjusted and calibrated. By continuously adjusting the emissivity setting, the temperature measured by the infrared thermometer is made as close as possible to the actual temperature, thereby improving the measurement accuracy.

[0048] In operation S240, the emissivity obtained by calibration is determined as the surface emissivity of the braking member.

[0049] According to an embodiment of the present disclosure, after calibrating the emissivity of the infrared thermometer in operation S230, if the temperature displayed by the infrared thermometer is the same as the temperature measured by other contact surface measuring instruments according to the calibration, the emissivity corresponding to the temperature of the infrared thermometer at this time is determined as the surface emissivity of the braking member.

[0050] According to an embodiment of the present disclosure, by directly measuring the braking components on the train, destructive behaviors such as cutting objects are avoided. This not only maintains the integrity and original working state of the braking components but also directly obtains the temperature and emissivity information during actual operation, ensuring that the measurement results accurately and real-time reflect the true characteristics of the braking components. Compared with the measurement method of cutting the braking components in the related art, the convenience and efficiency of the measurement are improved, without affecting the normal operation rhythm of the train. In addition, due to the large volume of the braking components in the train, although overall heating can meet the test requirements, the heating is difficult and costly. On the premise of meeting the emissivity calibration test requirements, the implementation of local heating can reduce the operation difficulty. At the same time, by reasonably designing the heating sheet, the temperature distribution in the heating area can be precisely controlled to meet the predetermined temperature distribution characteristics, enabling the braking components to reach a more stable and uniform temperature distribution state, which is beneficial to accurately determining the temperature measurement area, avoiding temperature measurement errors caused by uneven temperature, and improving the accuracy of emissivity calibration. At the same time, it is beneficial to simulate the temperature changes on the surface of the braking components under different braking conditions. Compared with the method of heating by cutting objects or heating the entire wheel or brake disc in the related art, the application scenario of measuring the surface emissivity is broadened.

[0051] According to an embodiment of the present disclosure, infrared thermometers are mainly divided into: short-wave infrared thermometers, mid-wave infrared thermometers, and long-wave infrared thermometers according to the wavelength range they detect. Since the braking components are usually made of metal, and the wheels or brake discs are in a high-speed rotating state in the actual application scenario.

[0052] According to an embodiment of the present disclosure, the predetermined temperature distribution characteristic is that the difference between the surface temperature and the central temperature of the heating area is less than a predetermined threshold, and the surface temperature and the central temperature are within a predetermined temperature range.

[0053] According to an embodiment of the present disclosure, the surface temperature refers to the temperature of the outer surface of the heating area that is directly in contact with the external environment. The central temperature refers to the temperature at the center or near the center of the heating area inside. During the heating process of the heating area, heat conducts from the generation site (such as the friction surface) to the inside. Since the internal heat conduction is relatively slow and does not directly exchange heat with the external environment like the surface, the central temperature is usually different from the surface temperature. The central temperature reflects the heat accumulation situation inside the braking component corresponding to the heating area. The difference between the central temperature and the surface temperature can be used to measure the temperature distribution uniformity of the braking component corresponding to the heating area. If the central temperature is too low compared to the surface temperature, it indicates that the center of the braking component corresponding to the heating area absorbs less heat and is mainly concentrated on the surface, and the internal heat has not been fully absorbed and conducted, which may be due to a short heating time or a low heating temperature.

[0054] In the embodiments of the present disclosure, a short-wave infrared measuring instrument is selected to measure the surface temperature of the temperature measurement area. However, when the surface temperature of the wheel or brake disc is relatively low, the wavelength of the infrared radiation emitted by it may become longer. Since the short-wave infrared measuring instrument can only receive infrared radiation within a specific short-wave wavelength range, the longer-wavelength infrared radiation emitted by the low-temperature object may exceed the wavelength range that the measuring instrument can receive at this time, resulting in the measuring instrument being unable to receive sufficient radiation signals to accurately determine the emissivity of the object surface. Based on this, the short-wave infrared measuring instrument has a higher measurement accuracy in the high-temperature range and a lower measurement accuracy in the low-temperature range. For example, when the temperature is below 50 degrees Celsius, an accurate temperature value cannot be measured. Therefore, not only the difference between the surface temperature and the center temperature needs to be considered to be less than a predetermined threshold, but also the surface temperature and the center temperature need to be controlled to meet the minimum temperature within a predetermined temperature range, such as higher than 50 °C.

[0055] According to the embodiments of the present disclosure, the local heating area of the braking member is usually made of metal, and the metal itself has good thermal conductivity, which makes its heat dissipation speed relatively fast. Due to different heating methods, for example, some heating methods conduct heat from the outside to the inside of the heating area, and some heating methods conduct heat from one part of the heating area to another part. During the heating process, heat conduction takes a certain amount of time, resulting in a significant increase in the difference between the surface temperature and the center temperature. It may increase the temperature gradient between the surface and the center, resulting in uneven temperature distribution in the heating area.

[0056] According to the embodiments of the present disclosure, by monitoring the temperature distribution data during the heating process and adjusting the heating time and heating temperature, the difference between the surface temperature and the center temperature of the local heating area of the braking member can be made to reach a relatively small value, less than a predetermined threshold, such as less than 10 degrees Celsius, etc. The surface temperature and the center temperature are close, so that the temperature of the object to be measured is in a relatively high and uniform temperature distribution state. Because during the emissivity calibration process after the heating is stopped, the surface temperature of the member to be measured basically remains unchanged. If the temperature difference between the surface and the center of the member is too large, the surface temperature will decrease rapidly, affecting the emissivity calibration. On the contrary, if the temperature difference between the surface and the center of the member is close, the surface temperature will be maintained within a relatively constant range, which is convenient for subsequent emissivity calibration. The temperature signal received by the infrared thermometer can truly reflect the actual temperature state of the temperature measurement area, thus ensuring the accuracy of temperature measurement.

[0057] In the embodiments of the present disclosure, a short-wave infrared measuring instrument is selected to measure the surface temperature of the local heating area of the braking member. However, when the surface temperature is relatively low, the wavelength of the infrared radiation emitted may become longer. Since the short-wave infrared measuring instrument can only receive infrared radiation within a specific short-wave wavelength range, the longer-wavelength infrared radiation emitted by the low-temperature object may exceed the wavelength range that the measuring instrument can receive at this time, resulting in the measuring instrument being unable to receive sufficient radiation signals to accurately determine the emissivity of the object surface. Based on this, the short-wave infrared measuring instrument has a higher measurement accuracy in the high-temperature range and a lower measurement accuracy in the low-temperature range. For example, when the temperature is below 50 degrees Celsius, accurate temperature values cannot be measured. Therefore, not only the difference between the surface temperature and the central temperature needs to be considered to be less than a predetermined threshold, but also the surface temperature and the central temperature need to be controlled to meet the minimum temperature within a predetermined temperature range, such as higher than 50 °C.

[0058] According to the embodiments of the present disclosure, the area measured by the surface temperature measuring instrument should be the same as that measured by the infrared thermometer to reduce the temperature measurement error. Since the measurement range and angle of the infrared thermometer are limited, it can only measure the surface temperature of the object within its field of view. Therefore, it is necessary to determine the area of the surface of the braking member that can be measured according to the installation position of the infrared thermometer. Further, after determining the temperature measurement areas measured by the surface temperature measuring instrument and the infrared thermometer, the heating range to be heated can be determined according to the temperature measurement area.

[0059] According to the embodiments of the present disclosure, determining the heating area for locally heating the braking member of the train includes steps 11 to 12.

[0060] Step 11: Determine the temperature measurement area on the surface of the braking member.

[0061] Step 12: Determine the heating area based on the temperature measurement area.

[0062] According to the embodiments of the present disclosure, the size of the temperature measurement light area is calculated based on the distance between the infrared thermometer and the surface of the object to be measured and the distance coefficient of the infrared thermometer. Among them, the temperature measurement area is generally circular, and the size is represented by the diameter. Further, with the center of the temperature measurement area as the origin, the heating area can be determined on the basis of the temperature measurement area by increasing the diameter by 1.5 - 5 times. For example, if the diameter of the temperature measurement area is determined to be 2 cm and the diameter of the heating area is determined to be 8 cm, with the center of the temperature measurement area as the origin, the circle with a diameter of 8 cm is determined as the heating area.

[0063] Figure 3 Schematically shows a schematic diagram of the positional relationship between the temperature measurement area and the heating area according to the embodiments of the present disclosure.

[0064] According to an embodiment of the present disclosure, since it is necessary to ensure that the temperature distribution within the temperature measurement region satisfies a predetermined temperature distribution characteristic, the heating region where heating is implemented needs to be greater than or equal to the temperature measurement region. Otherwise, it is difficult for the temperature distribution within the temperature measurement region to meet the test requirements. As Figure 3 shown, the heating region 302 represented by the red rectangle is larger than and includes the temperature measurement region 301 represented by the circle. Among them, Figure 3 the shapes of the temperature measurement region 301 and the heating region 302 in are only for illustrative purposes and can be any shape other than those shown in the figure. For example, both the temperature measurement region 301 and the heating region 302 are circular, or both are rectangular, etc., which will not be elaborated here. However, generally, since the light spot emitted by the infrared measuring instrument is generally circular, the temperature measurement region is generally circular. To facilitate the arrangement of the heating sheet, the heating region is generally set as a rectangle. The heating region being greater than or equal to the temperature measurement region effectively avoids the temperature measurement error caused by the boundary effect, ensures that the temperature within the temperature measurement region can accurately simulate the heat reception situation of the braking component during actual operation, and further improves the accuracy and reliability of the detection result of the thermal performance of the braking component.

[0065] According to an embodiment of the present disclosure, determining the temperature measurement region on the surface of the braking component includes: determining the temperature measurement region on the surface of the braking component based on the installation position of the infrared temperature measuring instrument installed near the braking component. Specifically, it includes step 21 to step 23.

[0066] Step 21, determine the center point based on the intersection point of the extension line of the detection head of the infrared temperature measuring instrument along the detection direction on the surface of the braking component.

[0067] According to an embodiment of the present disclosure, the detection head of the infrared temperature measuring instrument emits an infrared radiation detection signal along a specific direction.

[0068] One embodiment of determining the center point is that when the extension line of this detection direction intersects the surface of the braking component, an intersection point will be generated. This intersection point is selected as the center point for subsequent determination of the temperature measurement region. This center point is in the "directly in front" position of the detection of the infrared temperature measuring instrument and is representative for measuring the surface temperature of the braking component. Using it as the center point to delimit the temperature measurement region can better reflect the main temperature information detected by the infrared temperature measuring instrument.

[0069] Another embodiment for determining the center point is to install a cross slide rail composed of two mutually perpendicular slide rails at a suitable position near the braking member. Two measuring devices (positioning components) that can slide freely on the slide rails are respectively installed on the two slide rails. These two positioning components can be equipped with components such as high-precision positioning sensors or pointers for accurately indicating positions. The operator controls one of the positioning components to slide along one slide rail to approach the surface of the braking member until the positioning component (such as a pointer) on the positioning component contacts the surface of the braking member, and records the position data of the positioning component on this slide rail at this time. Control the other positioning component to slide along the slide rail perpendicular to it, also making it approach the surface of the braking member, so that this positioning component contacts the surface of the braking member, and at the same time records the position data of this measuring device on this slide rail at this time. Since the two slide rails are mutually perpendicular, the two perpendicular lines determined by the contact points of the two measuring devices on the surface of the braking member will intersect on the surface of the braking member. According to the position data recorded by these two positioning components, the intersection position of these two perpendicular lines on the surface of the braking member, that is, the center point, is determined through calculation. Through this cross-measurement method based on the cross slide rail, the center point can be determined relatively accurately, providing a reliable basis for determining the temperature measurement area of the infrared thermometer based on this center point in the subsequent process.

[0070] Step 22: Determine the measurement radius according to the straight-line distance between the detection head and the center point.

[0071] According to the embodiments of the present disclosure, in the working principle of the infrared thermometer, its measurement range is related to the distance from the detection head to the target object. For example, if the detection head is closer to the center point, the measurement radius may be relatively smaller, and vice versa. This is a mapping relationship set based on the characteristics of the infrared thermometer and to ensure measurement accuracy. Through this mapping relationship and the distance from the detection head to the center point, the measurement radius is determined, thereby determining a fixed and reasonable area where the infrared thermometer can measure the temperature of this area relatively accurately. Among them, the mapping relationship between the distance from the detection head to the surface of the target object and the measurement range can be determined according to the standard instruction manual of the infrared thermometer.

[0072] Step 23: Determine the temperature measurement area based on the center point and the measurement radius.

[0073] According to an embodiment of the present disclosure, after obtaining the center point and the measurement radius, the temperature measurement area can be determined. Taking the center point as the center of a circle and the measurement radius as the radius, a circle is drawn on the surface of the braking member (in the ideal case on a two-dimensional plane, which may vary in actual situations due to factors such as the shape of the braking member, but the principle is similar) or a corresponding area range. This area is the area where the infrared thermometer can effectively measure the temperature. In this way, the specific range measured by the infrared thermometer is clarified, making the temperature measurement more targeted and accurate, and also facilitating the analysis and evaluation of the surface temperature of the braking member.

[0074] According to an embodiment of the present disclosure, the braking member includes a wheel and / or a brake disc.

[0075] According to an embodiment of the present disclosure, in order to ensure the measurement accuracy of the emissivity, it is necessary to ensure that the local temperature of the braking member satisfies a predetermined temperature distribution characteristic during the emissivity measurement. Therefore, it is necessary to heat the heating area.

[0076] According to an embodiment of the present disclosure, after determining the heating area, heating the heating area includes steps 31 to 32.

[0077] Step 31: Arrange at least one heating sheet in the heating area or in an extended heating area formed based on the heating area based on the target local heating method, where the extended heating area is an area extending around the heating area as the center.

[0078] According to an embodiment of the present disclosure, the extended heating area is determined according to the heating area. If the heating area is circular, taking the center of the heating area as the origin, expanding 1 - 5 times on the basis of the diameter of the heating area, and determining it as the diameter of the extended heating area. If the heating area is rectangular, increase the side length of the heating area to expand the heating area to obtain an expanded heating area. Step 32: Energize at least one heating sheet to raise the temperature, and use the heating sheet after the temperature is raised to conduct heat to the heating area.

[0079] Figure 4 Schematically shows a schematic diagram of the positional relationship between the heating area and the extended heating area according to an embodiment of the present disclosure.

[0080] As Figure 4 shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302, and the blue rectangular dashed line frame represents the extended heating area 401. The heating sheet is pasted on the heating area 302 and / or the expanded heating area 401, and is connected by wires to provide a DC switch power supply for the heating sheet, where the heating sheet can be a constant temperature ceramic PTC heating sheet.

[0081] Further, different heating methods can be simulated through a simulation model. By observing the heating conditions of the local area of the braking component under different heating methods, a more preferable local heating method can be determined to heat the local heating area of the braking component using the preferable local heating method. Specifically, multiple local heating methods can be constructed first, and the computer simulation technology can be used to observe the heating results of different heating methods.

[0082] According to an embodiment of the present disclosure, before heating the heating area using a heating sheet, steps 41 to 43 are further included.

[0083] Step 41: Based on N local heating methods for the heating area, N local heating simulation models are established.

[0084] According to an embodiment of the present disclosure, in order to understand the respective effects of different heating methods before actual heating, using computer simulation technology, corresponding local heating simulation models are established according to each heating method. Each model can simulate the heat transfer and distribution in the heating area under various heating methods. Here, N is a positive integer greater than or equal to 1.

[0085] Step 42: Use the N local heating simulation models to simulate the heating processes of the N local heating methods, and output the simulation results of the temperature distribution in the heating area corresponding to the N local heating methods.

[0086] According to an embodiment of the present disclosure, the N local heating methods at least include the following four methods.

[0087] Figures 5A - 5E Schematically shows schematic diagrams of five local heating methods according to an embodiment of the present disclosure.

[0088] The first local heating method: In the extended heating area, and in the first area surrounding the heating area, a plurality of heating sheets are arranged.

[0089] As Figure 5A shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302 (the heating area includes the temperature measurement area), and the blue rectangular frame represents the extended heating area. A plurality of heating sheets 103 are arranged on the first area in the extended heating area. The surrounding heating sheets simultaneously heat the middle heating area, causing the heating area to warm up.

[0090] The second local heating method: In the extended heating area, and in the second area covering the entire heating area, at least one heating sheet is arranged, and the area of the second area is equal to the area of the heating area.

[0091] As Figure 5BAs shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302 (the heating area includes the temperature measurement area), and the blue rectangle represents the extended heating area. A plurality of heating sheets 103 are arranged on the second area within the extended heating area. After the heating sheets are energized, heat is generated, and the heat is directly transmitted downward to the heating area, and the heat transmitted to the heating area can be precisely controlled. Among them, as Figure 5B shown, the area of the second area covered by the heating sheet is equal to the area of the heating area. The heating sheet 103 can cover the second area with an effective gap or can be tightly covered on the second area. Thus, it can not only ensure that the heating area 302 is fully heated but also save heat consumption.

[0092] The third local heating method: within the extended heating area and on the second area that fully covers the heating area, at least one heating sheet is arranged, and the area of the second area is larger than the area of the heating area.

[0093] As Figure 5C shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302 (the heating area includes the temperature measurement area), and the blue rectangle represents the extended heating area. Among them, as Figure 5C shown, the area of the second area covered by the heating sheet is larger than the area of the heating area. The heating sheet 103 can cover the second area with an effective gap or can be tightly covered on the second area. Thus, it can ensure that the heating area is fully heated.

[0094] The fourth local heating method: within the extended heating area and on the second area that partially covers the heating area, at least one heating sheet is arranged.

[0095] Among them, the partial coverage of the heating area includes the following situations.

[0096] First, partially cover the heating area and completely cover the temperature measurement area.

[0097] As Figure 5D shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302 (the heating area includes the temperature measurement area), and the blue rectangle represents the extended heating area. As Figure 5D shown, the heating sheet 103 partially covers the heating area and completely covers the temperature measurement area. After the heating sheet is energized, heat is generated, and the heat is directly transmitted downward to the temperature measurement area, and the heat transmitted to the temperature measurement area can be precisely controlled. Among them, the area covered by the heating sheet is smaller than the heating area 302 but larger than the temperature measurement area 301. Thus, although the heating area is not completely covered, the temperature measurement area can be directly heated. After the temperature of the temperature measurement area rises, the heat energy diffuses to the surrounding area. Even if the heating area is not completely covered, the heat can also diffuse to the surrounding area to achieve uniform heating.

[0098] Second, it partially covers the heating area and does not cover the temperature measurement area at all.

[0099] As Figure 5E shown, the circle represents the temperature measurement area 301, the red rectangle represents the heating area 302 (the heating area includes the temperature measurement area), and the blue rectangle represents the extended heating area. Multiple small rectangular heating sheets are arranged around the temperature measurement area 301 and within the heating area 302. The heat generated by the heating sheets conducts towards the temperature measurement area from the diagonal direction, forming intersecting heat transfer paths.

[0100] The above local heating methods are only for illustrative purposes, but the present application is not limited thereto. There can be more other methods other than the local heating methods mentioned above, which will not be elaborated here.

[0101] According to an embodiment of the present disclosure, by running the above local heating simulation model, virtual simulations are performed on the heating processes of N local heating methods. Different parameters are input into the simulation model, the temperature changes in the heating area are calculated, and the simulation results of the temperature distribution in the heating area under each local heating method are output. Among them, the simulation results can be in the form of data tables, temperature nephograms, etc.

[0102] Figure 6A Schematically shows a simulation diagram of locally heating a wheel using a local heating method according to an embodiment of the present disclosure. Among them, Figure 6A Heating surfaces are arranged only on both sides of the same wheel tread as the temperature measurement area. Figure 6B Schematically shows a temperature field distribution diagram of locally heating a wheel using a local heating method according to an embodiment of the present disclosure.

[0103] Figure 7A Schematically shows a simulation diagram of locally heating a wheel using another local heating method according to an embodiment of the present disclosure. Among them, Figure 7A On the Figure 6A basis, heating sheets are also arranged on the other side of the wheel. Figure 7B Schematically shows a temperature field distribution diagram of locally heating a wheel using another local heating method according to an embodiment of the present disclosure.

[0104] According to an embodiment of the present disclosure, after heating for 2000 s, the temperature fields of the wheel tread temperature measurement area under the two heating block arrangement methods are basically stable, and the distributions of the temperature fields are respectively as Figure 6B and Figure 7B shown. Figure 6B It shows that using the Figure 6A shown heating sheet heating method, the temperature distribution in the temperature measurement area is relatively uniform, and the temperature value is stable between 109 - 111 °C. Figure 7B It shows that using Figure 7AIn the heating method of the heating sheet shown, the temperature gradient in the temperature measurement area is relatively large, and the temperature value is between 160 - 180 °C. It can be preliminarily judged that the temperature field in the temperature measurement area obtained by using Figure 6A the heating method of the heating sheet shown is more suitable for emissivity measurement. Through thermal simulation analysis, the temperature field in the temperature measurement area and its change characteristics under different heating device layout methods can be quickly calculated, so as to provide a basis for the design and optimization of the heating device layout method.

[0105] Step 43: Determine the target local heating method from N local heating methods based on the temperature distribution simulation results.

[0106] According to the embodiments of the present disclosure, analyze the temperature distribution simulation results, and select the most suitable target local heating method from various local heating methods according to aspects such as whether it can quickly reach the predetermined temperature range, whether it can quickly satisfy that the difference between the surface temperature and the center temperature is less than the predetermined threshold, and energy consumption.

[0107] Figure 8 Schematically shows a schematic diagram of a scenario for measuring the true temperature of the temperature measurement area using a surface thermometer according to an embodiment of the present disclosure.

[0108] According to the embodiments of the present disclosure, after the temperature of the area to be measured satisfies the predetermined temperature distribution characteristics, calibrating the emissivity of the infrared thermometer includes Step 51 to Step 53.

[0109] Step 51: Measure the true temperature of the temperature measurement area.

[0110] According to the embodiments of the present disclosure, use a surface thermometer to measure the true temperature of the temperature measurement area. The surface thermometer selects high-precision and calibrated standard temperature measurement equipment, such as thermocouple thermometers, resistance thermometers, etc. As Figure 8 shown, the staff touches the probe of the surface thermometer to the temperature measurement area for temperature measurement. This contact measurement can more accurately measure the true temperature of the temperature measurement area and provide a benchmark for subsequent comparison with the measurement results of the infrared thermometer.

[0111] Step 52: Measure the first temperature of the temperature measurement area based on the first emissivity set for the infrared thermometer.

[0112] According to the embodiments of the present disclosure, first set an initial emissivity value for the infrared thermometer, that is, the first emissivity. Then, use this infrared thermometer to measure the temperature of the same temperature measurement area, and the obtained temperature value is the first temperature. Since the emissivity set at this time may be inaccurate, the first temperature may deviate from the true temperature.

[0113] Step 53, in the case where the first temperature and the true temperature do not meet the predetermined numerical conditions, adjust the first emissivity to the second emissivity. When the second temperature of the temperature measurement area measured based on the second emissivity and the true temperature meet the predetermined numerical conditions, complete the calibration of the emissivity of the infrared thermometer, where the second emissivity is the calibrated emissivity.

[0114] According to an embodiment of the present disclosure, it is determined whether the first temperature and the true temperature meet the predetermined numerical conditions. The predetermined numerical conditions are a judgment criterion set in advance according to factors such as measurement accuracy requirements. For example, the difference between the two is within a certain range, or the ratio of the two is within a certain specific interval, etc.

[0115] According to an embodiment of the present disclosure, if the first temperature and the true temperature do not meet the predetermined numerical conditions, it indicates that the currently set first emissivity is inaccurate and needs to be adjusted. Adjust the first emissivity to the second emissivity, and then use the infrared thermometer to measure the temperature of the temperature measurement area again based on the second emissivity to obtain the second temperature.

[0116] According to an embodiment of the present disclosure, it is determined whether the second temperature and the true temperature meet the predetermined numerical conditions. If they meet, it means that by adjusting the emissivity, the measurement result of the infrared thermometer has been able to meet the accuracy requirements consistent with the true temperature. At this time, the calibration of the emissivity of the infrared thermometer is completed, and the second emissivity is determined as the finally calibrated emissivity. In this way, when measuring the temperature of the braking component using this infrared thermometer subsequently, this calibrated emissivity can be used to obtain a more accurate measurement result.

[0117] The above describes the embodiments of the present disclosure. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. A method for determining the emissivity of a braking member surface, comprising: Determining a heating area for locally heating the braking member of the train; Using a heating sheet to heat the heating area so as to raise the local temperature of the braking member and satisfy a predetermined temperature distribution characteristic; Using an infrared thermometer to measure the temperature of at least part of the heating area, and calibrating the emissivity of the infrared thermometer during the temperature measurement process; Determining the emissivity obtained by calibration as the surface emissivity of the braking member.

2. The method according to claim 1, wherein: The predetermined temperature distribution characteristic is that the difference between the surface temperature and the central temperature of the heating area is less than a predetermined threshold value, and the surface temperature and the central temperature are within a predetermined temperature range.

3. The method according to claim 1, using a heating sheet to heat the heating area includes: Arranging at least one heating sheet in the heating area or in an extended heating area formed based on the heating area based on a target local heating method, wherein the extended heating area is an area extending around the heating area; Applying power to the at least one heating sheet to raise the temperature, and using the heating sheet with the raised temperature to conduct heat to the heating area.

4. The method according to claim 3, further comprising establishing N local heating simulation models based on N local heating methods for the heating area; Using the N local heating simulation models to simulate the heating processes of the N local heating methods, and outputting the temperature distribution simulation results of the heating area corresponding to the N local heating methods; Based on the temperature distribution simulation results, determining the target local heating method from the N local heating methods.

5. The method according to claim 4, wherein The N local heating methods at least include: Arranging a plurality of heating sheets in a first area surrounding the heating area within the extended heating area; Arranging at least one heating sheet in a second area that completely covers the heating area within the extended heating area, and the area of the second area is equal to the area of the heating area; Arranging at least one heating sheet in a second area that completely covers the heating area within the extended heating area, and the area of the second area is greater than the area of the heating area; Arranging at least one heating sheet in a second area that partially covers the heating area within the extended heating area.

6. The method according to claim 1, wherein The braking member includes a wheel and / or a brake disc.

7. The method according to claim 1, wherein, Calibrating the emissivity of the infrared thermometer includes: Measuring the true temperature of the at least part of the area; Based on a first emissivity set for the infrared thermometer, measuring a first temperature of the at least part of the area; In the case where the first temperature and the true temperature do not satisfy a predetermined numerical condition, adjusting the first emissivity to a second emissivity, and completing the calibration of the emissivity of the infrared thermometer when the second temperature of the at least part of the area measured based on the second emissivity and the true temperature satisfy the predetermined numerical condition, wherein the second emissivity is the emissivity obtained by calibration.

8. The method according to claim 1, wherein Determining the heating area for locally heating the braking member of the train includes: Determining the temperature measurement area on the surface of the braking member; Determining the heating area based on the temperature measurement area.

9. The method according to claim 8, wherein, Determining the temperature measurement area on the surface of the braking member includes: Determining the temperature measurement area on the surface of the braking member based on the installation position of the infrared thermometer installed near the braking member.

10. The method according to claim 9, determining the temperature measurement area on the surface of the braking member based on the installation position of the infrared thermometer installed near the braking member includes: Determining the center point based on the intersection point of the extension line of the detection head of the infrared thermometer along the detection direction on the surface of the braking member; Determining the measurement radius according to the straight-line distance between the detection head and the center point; Determining the temperature measurement area based on the center point and the measurement radius.

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