System and method for temperature measurement calibration of sensor based on laser heating

Abstract

The invention relates to the technical field of heat conduction of high-energy laser heating materials, in particular to a system and a method for temperature measurement and calibration of a sensor based on laser heating. According to the invention, the constant-temperature area is constructed by shaping the light spot and heating the heated block by using the high-power laser light source, the sensor to be calibrated is placed in the constant-temperature area, and the temperature of the heated block in the constant-temperature working area is monitored in real time by using the thermodetector. According to temperature signals fed back by the power monitoring module and the thermodetector, the output power of the laser is adjusted, related lenses are adjusted, and the size of laser spots is changed, so that the power density of laser is changed, and the purpose of controlling the temperature of a heated block in real time is achieved. Meanwhile, by adjusting the temperature, such as controlling the temperature to continuously change at a preset rate or stabilizing the temperature at a preset value, the dynamic calibration test and the static calibration test of the sensor are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of heat conduction of high-energy laser-heated materials, and in particular to a system and method for sensor temperature measurement calibration based on laser heating. Background Art

[0002] In aircraft engines, a turboshaft engine (abbreviated as a turboshaft engine) primarily consists of several key components: the air inlet, compressor, combustion chamber, turbine, and tail nozzle. To achieve world-leading performance indicators for the new generation of turboshaft engines, and to enable aircraft equipped with these engines to fly at supersonic speeds, the company has undergone improvements in combustion chamber design and multiple rounds of technological iterations. Currently, after the combustion chamber fully burns the fuel and air provided by the compressor, the gas temperature rises sharply, accelerating its expansion. The gas temperature before the turbine can reach 1500-2200°C (typically the highest engine temperature range).

[0003] Excessively high turbine gas temperatures can reduce the metal strength of turbine blades, increase tip clearance, and cause blade creep and erosion, leading to component damage and potentially serious consequences such as compressor surge, in-flight flameout, and engine structural damage. As the engine's most critical hot-end rotating component, the turbine's high-temperature resistance directly determines the engine's maximum operating temperature. Accurately measuring the temperature of an aircraft engine's turbine and its surroundings is crucial for studying the turbine material's high-temperature resistance, stress distribution, and operating life. To accurately measure engine turbine temperature, it is necessary to address the challenges of insufficient sensor characteristic test calibration capabilities and a lack of calibration methods. Summary of the Invention

[0004] In view of this, the present invention provides a system and method for sensor temperature measurement and calibration based on laser heating to solve the technical problem of the lack of sensor testing and calibration methods in the prior art.

[0005] The technical solutions provided by the present invention are as follows:

[0006] In a first aspect, the present invention provides a system for sensor temperature measurement and calibration based on laser heating, the system comprising: a laser light source, a lens assembly, a temperature measurement module and a heated block; the laser light source is used to output a laser beam; the lens assembly is used to adjust the laser beam to output a uniform light spot of a preset shape to irradiate the two symmetrical surfaces of the heated block, the surface of the heated block having an opening of a preset shape; the heated block is used to generate a constant temperature cavity based on the uniform light spot of the preset shape, and the sensor to be calibrated is placed in the constant temperature cavity; the temperature measurement module is used to measure the temperature of the constant temperature cavity when the temperature of the constant temperature cavity changes, and calibrate the sensor to be calibrated according to the temperature.

[0007] In an optional embodiment, the lens assembly includes: a shaping assembly and a direction adjustment assembly; the shaping assembly is used to adjust the laser beam and output a uniform light spot of a preset shape; the direction adjustment assembly is used to split the uniform light spot and irradiate it on two symmetrical surfaces of the heated block respectively.

[0008] In an optional embodiment, the direction adjustment component includes a beam splitter and a reflector; the beam splitter is used to split the uniform light spot into two beams; and the reflector is used to irradiate the two split light spots onto two opposite surfaces of the heated block respectively.

[0009] In an optional embodiment, when the laser beam is a parallel beam of a preset shape, the shaping component includes a diffraction optical element, and the diffraction optical element is used to adjust the laser beam to a uniform light spot of a preset shape; when the laser beam is a non-parallel beam of a preset shape, the shaping component includes a collimating element and a diffraction optical element, the collimating element is used to collimate the laser beam, and the diffraction optical element is used to adjust the collimated beam to a uniform light spot of a preset shape; when the laser beam is a non-parallel beam of a non-preset shape, the shaping component includes a collimating element, a microlens array, a focusing element and a plano-concave lens, the microlens array is used to convert the laser beam collimated by the collimating element into a beam of a preset shape, the focusing element is used to focus the laser beam of a preset shape, and the plano-concave lens is used to parallelize the focused laser beam and output a uniform light spot of a preset shape.

[0010] In an optional embodiment, the heated block includes an outer layer structure and an inner layer structure; the outer layer structure has openings on three sides, wherein two symmetrical surfaces have first openings of a preset shape, the first openings are used to receive a uniform light spot of a preset shape, the openings on the third surface of the outer layer structure are used to place a laser to be calibrated, the thermal conductivity of the outer layer structure is less than a first preset value; the thermal conductivity of the inner layer structure is greater than a second preset value, and the sensor to be calibrated is placed in the inner layer structure.

[0011] In an optional embodiment, the system further includes: a power monitoring module, a water cooler and a CNC host; the power monitoring module is used to monitor the power of the laser beam output by the laser light source; the CNC host is used to adjust the power of the laser light source based on the power and temperature to adjust the temperature of the constant temperature chamber, and the water cooler is used to cool the laser light source.

[0012] In an optional embodiment, the system further comprises: a load constant temperature control chamber, the inner wall of which is provided with refractory bricks, and the heated block is placed in the load constant temperature control chamber.

[0013] In a second aspect, the present invention provides a method for sensor temperature measurement and calibration based on laser heating, which is applied to the system for sensor temperature measurement and calibration based on laser heating as described in the first aspect of the present invention and any one of the first aspects, the method comprising: controlling the temperature of the constant temperature chamber to continuously change at a preset rate; dynamically calibrating the sensor to be calibrated according to the responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process; controlling the temperature of the constant temperature chamber to be stable at a preset value; and statically calibrating the sensor to be calibrated according to the temperature measured by the temperature measurement module.

[0014] In an optional embodiment, before controlling the temperature of the constant temperature chamber to change continuously at a preset rate, the method further includes: performing thermodynamic simulation on heated blocks of different materials and different sizes to obtain a temperature rise curve and a temperature distribution diagram; and determining the structure of the heated block based on the temperature rise curve and the temperature distribution diagram.

[0015] In a third aspect, the present invention provides a device for sensor temperature measurement and calibration based on laser heating, which is applied to the system for sensor temperature measurement and calibration based on laser heating as described in the first aspect of the present invention and any one of the first aspects, and the device includes: a first control module, used to control the temperature of the constant temperature chamber to continuously change at a preset rate; a dynamic calibration module, used to dynamically calibrate the sensor to be calibrated according to the responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process; a second control module, used to control the temperature of the constant temperature chamber to be stable at a preset value; and a static calibration module, used to statically calibrate the sensor to be calibrated according to the temperature measured by the temperature measurement module.

[0016] The technical solution of the present invention has the following advantages:

[0017] In this invention, by precisely shaping the light beam, a spot shape is achieved that matches the shape of the heated block opening. This creates a more regular and uniform illumination area within the constant-temperature chamber, thereby covering a larger area. This not only improves the uniformity of the temperature field within the constant-temperature chamber, but also ensures stable constant temperature conditions over a larger area. Therefore, this invention plays a significant role in improving the efficiency of constant-temperature chambers and expanding their effective operating area, providing a wider and more uniform constant-temperature environment for calibration and testing of ultra-high-temperature sensors, further enhancing the performance and practicality of the entire system. Furthermore, by adjusting the light beam through the lens assembly, this invention achieves a transition from the traditional single-sided illumination method to an innovative double-sided illumination method. This improvement significantly improves the temperature stability within the constant-temperature chamber. In this double-sided illumination mode, the light beam can evenly illuminate the interior of the constant-temperature chamber from two opposing directions, thus avoiding the temperature gradient problem caused by single-sided illumination. This double-sided illumination design not only improves the uniformity of temperature distribution but also reduces local overheating that can occur due to heat concentration, ensuring the stability and reliability of the internal environment of the constant-temperature chamber and providing more precise temperature conditions for calibration and testing of ultra-high-temperature sensors.

[0018] In the present invention, the inner wall of the constant temperature control chamber for the load is covered with refractory bricks. The high thermal resistance of refractory bricks is cleverly utilized, so that the area where the heated block is placed can be effectively insulated. The implementation of this structure significantly improves the thermal insulation effect of the constant temperature control chamber and effectively isolates the influence of external temperature changes on the internal temperature field. Therefore, even when the external ambient temperature fluctuates greatly, the constant temperature control chamber for the load can still maintain the temperature stability of the area where the heated block is located, preventing the temperature gradient problem caused by external temperature changes. As a result, not only the uniformity and stability of the temperature during the calibration process are ensured, but also the accuracy and repeatability of the calibration test of the ultra-high temperature sensor are greatly improved, laying a solid foundation for the reliability of the data and the in-depth scientific research.

[0019] In this invention, a constant temperature zone is created by shaping the light spot and heating the heated block with a high-power laser light source. The sensor to be calibrated is placed in this constant temperature zone, and a thermometer is used to monitor the temperature of the heated block in the constant temperature working area in real time. Based on the temperature signals fed back by the power monitoring module and the thermometer, the laser output power is adjusted, the relevant lenses are adjusted, and the laser spot size is changed to change the laser power density, achieving real-time control of the heated block temperature. Furthermore, by adjusting the temperature, such as controlling the temperature to continuously change at a preset rate or to stabilize the temperature at a preset value, dynamic and static calibration tests of the sensor can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 1 is a structural block diagram of a system for sensor temperature measurement and calibration based on laser heating in an embodiment of the present invention;

[0022] Figure 2 Schematic diagram of the structure of a system for sensor temperature measurement and calibration based on laser heating in an embodiment of the present invention;

[0023] Figure 3 Schematic diagram of the structure of the heating block in an embodiment of the present invention;

[0024] Figure 4 Schematic diagram of the structure of the constant temperature control chamber for loads in an embodiment of the present invention;

[0025] Figure 5 This is a flow chart of a method for sensor temperature measurement and calibration based on laser heating in an embodiment of the present invention;

[0026] FIG6(a) and FIG6(b) are temperature comparison diagrams of the heat block under 300W laser irradiation simulation when graphite felt is used as the heat insulation layer (outer layer structure) in an embodiment of the present invention;

[0027] FIG7( a ) and FIG7 ( b ) are temperature comparison diagrams of single-sided irradiation and double-sided irradiation simulated by 300W laser irradiation in an embodiment of the present invention;

[0028] FIG8( a ) and FIG8 ( b ) are temperature comparison diagrams of single-sided irradiation and double-sided irradiation simulations using 300W laser irradiation when graphite felt is used as the outer layer structure in an embodiment of the present invention;

[0029] FIG9(a) and FIG9(b) are temperature comparison diagrams of a 300W laser irradiation simulation when the light spot shape is consistent with the opening of the heated block in an embodiment of the present invention;

[0030] Figure 10 is a structural block diagram of a device for sensor temperature measurement and calibration based on laser heating according to an embodiment of the present invention;

[0031] Figure 11 Schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] As mentioned in the background section, turbofan engines generate greater thrust by adding afterburners. This technological approach has enabled turbine inlet temperatures in modern advanced engines to exceed 2000°C. However, excessively high gas temperatures can severely damage critical components such as turbine blades. Therefore, the ability of sensors to accurately monitor temperatures in the combustion chamber and turbine area is crucial for studying material resistance to high temperatures, optimizing thermal stress distribution, and predicting component life. To ensure the measurement accuracy and reliability of ultra-high-temperature sensors in the high-temperature range, high-temperature calibration is particularly important.

[0035] Based on this, the present invention provides a system for sensor temperature measurement and calibration based on laser heating, which improves the stability and uniformity of the constant temperature cavity through two-way symmetrical irradiation and matching the shape of the light spot with the shape of the heated block, thereby realizing sensor calibration based on the constant temperature cavity.

[0036] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0037] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] The embodiment of the present invention provides a system for sensor temperature measurement and calibration based on laser heating, such as Figure 1 As shown, the system includes: a laser light source, a lens assembly, a temperature measurement module and a heated block; the laser light source is used to output a laser beam; the lens assembly is used to adjust the laser beam to output a uniform light spot of a preset shape to irradiate the two symmetrical surfaces of the heated block, and the surface of the heated block has an opening of a preset shape; the heated block is used to generate a constant temperature cavity based on the uniform light spot of the preset shape, and the sensor to be calibrated is placed in the constant temperature cavity; the temperature measurement module is used to measure the temperature of the constant temperature cavity when the temperature of the constant temperature cavity changes, and calibrate the sensor to be calibrated according to the temperature.

[0039] The laser light source utilizes a high-power laser. Specifically, the laser has the characteristics of high power and a pulse width shorter than the sensor's time constant, thereby enabling the output of a high-power laser beam. Thus, by irradiating the heated block with the light spot output by the laser light source, the temperature of the constant-temperature cavity formed in the heated block can be increased to a relatively high value, i.e., a high-temperature environment is created, facilitating high-temperature calibration of the sensor to be calibrated. Specifically, the laser light source can utilize a semiconductor laser, a fiber laser, a solid-state laser, a gas laser, a chemical laser, a free electron laser, or other types of lasers. This embodiment does not limit the specific type of laser employed. Furthermore, the sensor to be calibrated can be a sensor for monitoring the temperature of a turbofan engine, i.e., the sensor can achieve temperature monitoring between 200°C and 2200°C. Therefore, the constant-temperature cavity formed by irradiating the heated block with the laser light source in this embodiment needs to be able to reach a temperature between 200°C and 2200°C to facilitate calibration of the sensor to be calibrated.

[0040] The temperature measurement module specifically includes a thermometer and other structures for temperature measurement. In this embodiment, the temperature measurement module includes a thermocouple thermometer, a high-speed photoelectric thermometer, and an infrared thermal imager. The thermocouple thermometer can penetrate deep into the high-temperature cavity (constant temperature cavity) and measure temperatures at different depths of the cavity. Specifically, the thermocouple thermometer can place the thermocouple wire and the sensor to be calibrated close together during temperature measurement. The actual temperatures measured by the thermocouple thermometer and the sensor to be calibrated are considered consistent if the error between the two values ​​is no more than 10 degrees. During calibration, the temperature measurement of the sensor to be calibrated can be corrected based on a comparison of the measured values. The high-speed photoelectric thermometer can measure the temperature at the bottom of the constant temperature cavity and the external temperature of the light spot, thereby providing auxiliary temperature monitoring. The infrared imager can capture the surface of the sensor to be calibrated and display the surface wire temperature, thereby providing auxiliary temperature measurement. In practical applications, the thermocouple thermometer can use different types of thermocouples, such as K-type thermocouples, B-type thermocouples, and C-type thermocouples. In other embodiments, a fiber Bragg grating sensor may be used instead of a thermocouple temperature measuring device.

[0041] The surface opening of the heated block can be configured based on the shape of the sensor to be calibrated. For example, if the sensor to be calibrated is cylindrical, a circular opening is used; if the sensor to be calibrated is square, a square opening is used. Furthermore, the shape of the light spot generated by the lens assembly is configured based on the shape of the opening in the heated block, i.e., the two openings are configured to have the same shape. This not only allows the sensor to be placed in the heated block, but also allows the uniform light spot to be illuminated more deeply within the heated block, establishing a stable temperature environment for the sensor to be calibrated.

[0042] The specific components included in the lens assembly can be arranged according to the spot shape of the laser beam and the adjusted spot shape. The components in the lens assembly can also be fixed with a fixture to facilitate the movement of each component.

[0043] The laser heating-based system for sensor temperature measurement and calibration provided by the present invention obtains a light spot shape that is consistent with the shape of the opening of the heated block by precisely shaping the light beam, thereby forming a more regular and uniform irradiation area in the constant temperature chamber, thereby covering a larger area. At the same time, it not only improves the uniformity of the temperature field in the constant temperature chamber, but also ensures that stable constant temperature conditions are achieved in a larger area. Therefore, the present invention plays an important role in improving the efficiency of the constant temperature chamber and expanding the effective working area, providing a wider and more uniform constant temperature environment for the calibration and testing of ultra-high temperature sensors, and further enhancing the performance and practicality of the entire system. In addition, the present invention realizes the transition from the traditional single-sided irradiation method to the innovative double-sided irradiation method through the adjustment of the light beam by the lens assembly. This improvement significantly improves the temperature stability inside the constant temperature chamber. In the double-sided irradiation mode, the light beam can be evenly irradiated to the interior of the constant temperature chamber from two opposite directions, thereby avoiding the temperature gradient problem caused by single-sided irradiation. This double-sided illumination design not only improves the uniformity of temperature distribution, but also reduces local overheating that may be caused by heat concentration, ensuring the stability and reliability of the internal environment of the constant temperature chamber, and providing more precise temperature conditions for the calibration and testing of ultra-high temperature sensors.

[0044] In an optional embodiment, the lens assembly includes: a shaping assembly and a direction adjustment assembly; the shaping assembly is used to adjust the laser beam to output a uniform light spot of a preset shape; the direction adjustment assembly is used to split the uniform light spot and then irradiate it onto two symmetrical surfaces of the heated block. The direction adjustment assembly includes a beam splitter and a reflector; the beam splitter is used to split the uniform light spot into two beams; the reflector is used to irradiate the two split light spots onto two opposite surfaces of the heated block.

[0045] When the laser beam is a parallel beam of a preset shape, the shaping component includes a diffraction optical element, which is used to adjust the laser beam into a uniform light spot of a preset shape; when the laser beam is a non-parallel beam of a preset shape, the shaping component includes a collimating element and a diffraction optical element, the collimating element is used to collimate the laser beam, and the diffraction optical element is used to adjust the collimated beam into a uniform light spot of a preset shape; when the laser beam is a non-parallel beam of a non-preset shape, the shaping component includes a collimating element, a microlens array, a focusing element and a plano-concave lens, the microlens array is used to convert the laser beam collimated by the collimating element into a beam of a preset shape, the focusing element is used to focus the laser beam of a preset shape, and the plano-concave lens is used to parallelize the focused laser beam and output a uniform light spot of a preset shape.

[0046] Among them, when the laser beam is a non-parallel beam with a non-preset shape (for example, the laser beam is circular and the preset shape is square), Figure 2 As shown, the system includes a computer 1, a high-power laser 2, a plano-convex lens 3, a microlens array 4, a biconvex lens 5, a plano-concave lens 6, a first reflector 7, a beam splitter 8, a second reflector 9, a third reflector 10, a fourth reflector 11, and a first heated block 12 with a square opening. The computer 1 is used to control the output power of the high-power laser 2. The laser beam output by the high-power laser 2 is collimated by the plano-convex lens 3 and then enters the microlens array 4 for shape adjustment and homogenization. The laser beam of a preset shape output by the microlens array 4 is focused by the biconvex lens 5 and parallelized by the plano-concave lens 6. The uniform light spot of the preset shape output by the plano-concave lens 6 is reflected by the first reflector 7 and then input into the beam splitter 8, where it is split into two beams of equal power. One beam is reflected by the second reflector 9 and enters an opening in the heated block; the other beam is reflected by the third reflector 10 and the fourth reflector 11 and enters another opening in the heated block.

[0047] In this system, the microlens array 4, the biconvex lens 5, and the plano-concave lens 6 form a beam-shaping lens group 14, which is used to adjust the shape of the light spot. When the heated block 15 is replaced with a heated block 13 with a circular opening (in this case, the laser beam also forms a circular light spot), the beam-shaping lens group 14 can be replaced with a diffractive optical element. In this case, there is no need to adjust the light spot shape; only the diffractive optical element needs to be used for homogenization. In addition, a micro-control platform can also be provided in the system. This platform is used to adjust the position of the four reflectors to ensure that the light spots reaching the surface of the heated block are of uniform size and symmetrical position.

[0048] In practical applications, the microlens array can adopt a cylindrical double-sided orthogonal structure, the size of which is larger than the spot diameter of the light beam before reaching the array. For example, the unit half-width of the microlens array is 0.75mm, the thickness is 1.2mm, the radius of curvature is -19.6, the period is 20×20, and the material is silicon dioxide. The radius of curvature of one spherical surface of the biconvex lens is 1:45.1, the net aperture is 12.7mm, the thickness is 4.1mm, and the radius of curvature of the other spherical surface is 2:-45.1, and the material is silicon dioxide. The concave surface curvature radius of the plano-concave lens is 1:-13.8, the net aperture is 6.35mm, the thickness is 4mm, and the material is silicon dioxide. It should be noted that the above is an example of the parameters of the various components of the beam shaping lens group. In other embodiments, other parameters can also be used. In addition, it should be noted that the structure of the microlens array can be determined according to the shape of the light spot. For example, when the light spot is hexagonal, a hexagonal microlens array is used.

[0049] In an optional embodiment, the heated block includes an outer layer structure and an inner layer structure; the outer layer structure has openings on three sides, wherein two symmetrical surfaces have first openings of a preset shape, the first openings are used to receive a uniform light spot of a preset shape, the openings on the third surface of the outer layer structure are used to place a laser to be calibrated, the thermal conductivity of the outer layer structure is less than a first preset value; the thermal conductivity of the inner layer structure is greater than a second preset value, and the sensor to be calibrated is placed in the inner layer structure.

[0050] For the heated block, its structure is as follows Figure 3 As shown, it specifically includes an outer structure 16, an inner structure 17, a laser irradiation hole 18, and a hole 19 for placing the sensor to be calibrated. The outer structure 16 is made of a low-thermal-conductivity material, while the inner structure 17 is made of a high-thermal-conductivity material. The laser irradiation hole 18 comprises a first opening with a preset shape (a square shape in this embodiment) provided on two symmetrical surfaces of the outer structure. The sensor placement hole 19 is an opening provided on a third surface of the outer structure for receiving the sensor to be calibrated. The inner structure has no openings, so when the light spot enters through the laser irradiation hole, it directly impinges on the surface of the inner structure.

[0051] The inner layer structure is made of a material having a thermal conductivity greater than a second preset value, i.e., a relatively high thermal conductivity, thereby forming a high-temperature cavity under heat. The outer layer structure is made of a material having a thermal conductivity less than a first preset value, i.e., a relatively low thermal conductivity, thereby insulating and retaining heat within the internal cavity. Specifically, the materials of the inner and outer layers of the heat block can be non-metallic materials, metallic materials, a mixture of non-metallic and metallic materials, alloy materials, etc., as long as the aforementioned thermal conductivity requirements are met.

[0052] In this embodiment, graphite felt material is used for the outer structure. Because the thermal conductivity of graphite felt material is extremely low, it can lock in internal heat and play a role in heat preservation. This effectively increases the upper temperature limit of the system. Specifically, graphite felt, as a high-performance thermal insulation material, has excellent high temperature resistance and thermal stability, and can provide a reliable protective layer for the heated block. Through the application of this protective layer, the service life of the heated block in a high temperature environment is significantly extended, and at the same time, its ability to withstand and transfer heat is also enhanced. Therefore, this design of the present invention not only effectively prevents the oxidation and damage of the heated block at high temperatures, but also greatly improves the operating temperature range of the system, so that the system can work stably under higher temperature conditions, thereby providing a wider temperature range for the calibration test of ultra-high temperature sensors, and further improving the flexibility and accuracy of experiments and tests. In other embodiments, the graphite felt can be replaced with an aerogel composite material to further improve the thermal insulation performance.

[0053] In an optional embodiment, the system further includes: a power monitoring module, a water cooler and a CNC host; the power monitoring module is used to monitor the power of the laser beam output by the laser light source; the CNC host is used to adjust the power of the laser light source based on the power and temperature to adjust the temperature of the constant temperature chamber, and the water cooler is used to cool the laser light source.

[0054] Among them, the power monitoring module includes a power beam splitter and a power meter. The power beam splitter is used to split the laser beam output by the laser light source, wherein most of the beam is used to transmit to the rear end to irradiate the heated block, and a small part of the beam is transmitted to the power meter for real-time monitoring. The power meter can determine the power output of the laser light source based on the splitting ratio and the received beam. The CNC host is capable of digitally controlling the laser light source and can control the output power of the laser light source in real time according to the power monitored by the power meter. The laser light source can emit continuous light, pulsed light, stepping light, etc. to meet different needs. Specifically, continuous light is light that continuously emits the same power. Pulsed light is light that is emitted for a period of time, such as 1s, then turned off for a period of time, such as 2s (it can also be consistent with the emission time), and then emits light for 1s repeatedly. Stepping light is light that emits a specific power, such as 100W, and irradiates for a period of time, the light power becomes 200W (the step size can be set by yourself), then irradiates for a period of time, and then steps again, and so on. In addition, the system also includes a water cooler, which can cool the laser light source during its operation to prevent the laser light source from being damaged by excessive temperature.

[0055] The system also includes a comprehensive display and control subsystem, which enables visual data transmission. For example, it can display the power of the laser source and the temperature rise curve of the constant temperature chamber, and provide synchronous feedback control of the laser source and beam shaping system. This system can include an FPGA control board, a PC, and related software algorithms.

[0056] In an optional embodiment, the system further comprises: a load constant temperature control chamber, the inner wall of which is provided with refractory bricks, and the heated block is placed in the load constant temperature control chamber. The structure of the load constant temperature control chamber provided in the system is as follows: Figure 4 As shown, in this structure, a high-speed photoelectric thermometer 20, a thermocouple thermometer 21 and a load constant temperature control chamber 22 are specifically included, wherein the thermocouple thermometer 21 penetrates into the load constant temperature control chamber 22 to perform temperature measurement.

[0057] In the present invention, the inner wall of the constant temperature control chamber for the load is covered with refractory bricks. The high thermal resistance of refractory bricks is cleverly utilized, so that the area where the heated block is placed can be effectively insulated. The implementation of this structure significantly improves the thermal insulation effect of the constant temperature control chamber and effectively isolates the influence of external temperature changes on the internal temperature field. Therefore, even when the external ambient temperature fluctuates greatly, the constant temperature control chamber for the load can still maintain the temperature stability of the area where the heated block is located, preventing the temperature gradient problem caused by external temperature changes. As a result, not only the uniformity and stability of the temperature during the calibration process are ensured, but also the accuracy and repeatability of the calibration test of the ultra-high temperature sensor are greatly improved, laying a solid foundation for the reliability of the data and the in-depth scientific research.

[0058] In the present invention, by accurately measuring and distributing high-energy laser energy and combining it with advanced temperature control technology, the system can achieve highly uniform temperature distribution in a complex heating environment, that is, it constructs a specific constant temperature area, in which the temperature fluctuation does not exceed 50 degrees, which can be considered accurate for extremely high temperature environments. Therefore, in this area, even if the sensor position is offset (for example, the sensor position is not within the predetermined area due to some reasons), the temperature monitored by the sensor is still the temperature within the predetermined area, without any fluctuation. That is, the constant temperature chamber has a high temperature stability, and this feature greatly improves the reliability and applicability of the system. This provides a solid temperature guarantee for various high-precision processing and experimental operations.

[0059] In an optional embodiment, in the system for sensor temperature measurement and calibration based on laser heating, the working principle is as follows:

[0060] When an object's temperature is above absolute zero, it theoretically emits thermal radiation. Thermal radiation transfers energy in the form of electromagnetic waves, which can propagate independently of any medium, even in a vacuum. The higher the temperature of an object, the stronger its thermal radiation. At the same temperature, objects with higher emissivity radiate more strongly. When the temperature of the heat sink is the same as the surrounding environment, radiative heat transfer becomes a dynamic process; the sink continues to radiate and absorb heat, but the total amount of heat radiated and absorbed is zero.

[0061] The heat sink at temperature T1 has an emissivity of ε and a surface area of ​​A. The heat transfer from the heat sink to the cavity at temperature T2 is expressed as:

[0062]

[0063] Where Φ represents the heat flux radiated outward by the heated block, and σ represents the Stepan-Boltzmann constant. The total reflectivity of the heated block cavity is expressed as ρ n , ρ represents the reflectivity of a surface, and n is the number of all reflected rays.

[0064] Since solid materials are opaque, the transmission τ = 0. If p < 1, the emissivity increases with the number of reflections. In the limit, as n → ∞, p → 1, and an air cavity will have a higher emissivity than the surface. Therefore, the emissivity of a heat source can be increased by constructing a cavity.

[0065] According to an embodiment of the present invention, a method embodiment for sensor temperature measurement calibration based on laser heating is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0066] In this embodiment, a method for sensor temperature measurement and calibration based on laser heating is provided, which can be used in the system for sensor temperature measurement and calibration based on laser heating in the above embodiment. Figure 5 FIG. 1 is a flow chart of a method for sensor temperature measurement calibration based on laser heating according to an embodiment of the present invention. Figure 5 As shown, the process includes the following steps:

[0067] Step S101 , controlling the temperature of the constant temperature chamber to change continuously at a preset rate.

[0068] Step S102 : dynamically calibrating the sensor to be calibrated according to responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process.

[0069] Step S103: controlling the temperature of the constant temperature chamber to be stable at a preset value.

[0070] Step S104: statically calibrate the sensor to be calibrated according to the temperature measured by the temperature measurement module.

[0071] The calibration process in this embodiment includes dynamic and static calibration, both of which require adjusting the temperature of the constant-temperature chamber. Specifically, this adjustment primarily involves controlling the laser light pulse and optical power to ensure the accuracy of the laser pulse rise time and temperature control. This allows for control of the constant-temperature chamber temperature rise rate during dynamic calibration and the constant-temperature zone temperature during static calibration.

[0072] During dynamic calibration, the temperature of the constant temperature chamber is controlled to change continuously at a certain rate (temperature rise rate). A high-response temperature measurement device, such as a thermocouple thermometer, is used to measure the temperature of the sensor to be calibrated. The temperature rise rate of the temperature measurement device and the sensor to be calibrated are compared to correct the error of the sensor to be calibrated. This dynamic calibration focuses on the rate of temperature change and is suitable for environments where sensors are dynamically measured.

[0073] During static calibration, the temperature of the constant temperature chamber is controlled to stabilize at a certain constant temperature point (the temperature in the constant temperature zone). After the system is fully balanced, the sensor to be calibrated is calibrated according to the thermocouple thermometer value. Specifically, during static calibration, the sensor to be calibrated and the thermocouple thermometer are moved at the target temperature (such as 500°C). Each point is measured for 2-5 minutes, and at least 3 points are measured. The average value is taken to reduce the error. The deviation between the sensor to be calibrated and the thermocouple thermometer is compared, and the correction value is calculated. The sensor to be calibrated is corrected. This static calibration focuses on the stability of the constant temperature circuit and is suitable for high-precision scenarios.

[0074] In addition, in order to realize the movement of the sensor and thermocouple temperature meter to be calibrated in static calibration, a multi-axis micro-motion control platform can be set in the above system to control the movement process to reduce the error caused by human movement.

[0075] In this invention, a constant temperature zone is created by shaping the light spot and heating the heated block with a high-power laser light source. The sensor to be calibrated is placed in this constant temperature zone, and a thermometer is used to monitor the temperature of the heated block in the constant temperature working area in real time. Based on the temperature signals fed back by the power monitoring module and the thermometer, the laser output power is adjusted, the relevant lenses are adjusted, and the laser spot size is changed to change the laser power density, achieving real-time control of the heated block temperature. Furthermore, by adjusting the temperature, such as controlling the temperature to continuously change at a preset rate or to stabilize the temperature at a preset value, dynamic and static calibration tests of the sensor can be achieved.

[0076] In an optional embodiment, before controlling the temperature of the constant temperature chamber to change continuously at a preset rate, the method further includes: performing thermodynamic simulation on heated blocks of different materials and different sizes to obtain a temperature rise curve and a temperature distribution diagram; and determining the structure of the heated block based on the temperature rise curve and the temperature distribution diagram.

[0077] Specifically, this embodiment uses finite element simulation software to perform thermodynamic simulations and determine the target material's absorption characteristics under high-energy lasers of varying energy densities. This analysis then analyzes the target's temperature characteristics when it reaches thermal equilibrium, such as whether the temperature distribution within the heated block is uniform. Ultimately, temperature rise curves and temperature distribution diagrams are obtained for different materials and sizes, enabling the selection of structural designs that achieve higher temperatures at the same laser power.

[0078] In addition, in addition to using finite element simulation software for the above-mentioned thermodynamic simulation, finite element simulation software can also be used to simulate the structure of the system. The simulation results are shown in Figures 6 to 9, where the horizontal axis is time and the vertical axis is temperature. In this simulation, a graphite block is used as the heat block. As shown in Figures 6(a) and 6(b), it is a temperature comparison diagram of the heat block under 300W laser irradiation simulation with or without graphite felt as the heat insulation layer (outer structure) (wherein, Figure 6(a) is with graphite felt, and Figure 6(b) is without graphite felt). It can be seen that in terms of maximum temperature control, the performance of the heat block using graphite felt is significantly improved compared to the heat block without graphite felt. This is because the low thermal conductivity of graphite felt effectively blocks the leakage of heat, reduces the heat loss of the heat equalizing block, and thus ensures the uniformity and stability of the internal temperature. Figures 7(a) and 7(b) show temperature comparisons of single-sided irradiation (i.e., irradiating only one side of the heated block) and double-sided irradiation (i.e., irradiating both sides of the heated block) simulated by 300W laser irradiation (Figure 7(a) shows single-sided irradiation without graphite felt, and Figure 7(b) shows double-sided irradiation without graphite felt). It can be seen that double-sided irradiation outperforms single-sided irradiation in terms of temperature uniformity, demonstrating the important influence of irradiation strategy on temperature distribution. Figures 8(a) and 8(b) show temperature comparisons of single-sided irradiation and double-sided irradiation simulated by 300W laser irradiation when graphite felt is used as the outer layer (Figure 8(a) shows single-sided irradiation with graphite felt, and Figure 8(b) shows double-sided irradiation with graphite felt). It can be seen that, thanks to the graphite felt insulation layer, double-sided irradiation not only improves temperature uniformity but also significantly enhances the temperature rise efficiency compared to the double-sided irradiation shown in Figures 7(a) and 7(b). As shown in Figures 9(a) and 9(b), these are temperature comparison diagrams of 300W laser irradiation simulation when the light spot shape is consistent with the opening of the heated block (Figure 9(a) shows that the light spot shape is consistent with the opening, and Figure 9(b) shows that the light spot shape is inconsistent with the opening). It can be seen that using a square light spot that matches the opening shape for irradiation can achieve a more uniform distribution of energy, thereby optimizing the overall heating effect of the heat equalizing block.

[0079] This embodiment also provides a device for sensor temperature measurement calibration based on laser heating. This device is used to implement the above-mentioned embodiments and preferred embodiments, and the details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0080] This embodiment provides a device for sensor temperature measurement and calibration based on laser heating, such as Figure 10 As shown, the device includes:

[0081] The first control module 31 is used to control the temperature of the constant temperature chamber to change continuously at a preset rate.

[0082] The dynamic calibration module 32 is used to dynamically calibrate the sensor to be calibrated according to the responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process.

[0083] The second control module 33 is used to control the temperature of the constant temperature chamber to be stable at a preset value.

[0084] The static calibration module 34 is used to perform static calibration on the sensor to be calibrated according to the temperature measured by the temperature measurement module.

[0085] The embodiment of the present invention also provides a computer device having the above Figure 10 The device shown is for sensor temperature measurement calibration based on laser heating.

[0086] See also Figure 11 , Figure 11 is a structural diagram of a computer device provided by an optional embodiment of the present invention, such as Figure 11 As shown, the computer device includes: one or more processors 100, memory 200, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components utilize different buses to communicate with each other and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of a GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Equally, multiple computer devices can be connected, and each device provides part of the necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 11 A processor 100 is taken as an example.

[0087] The processor 100 may be a central processing unit (CPU), a network processor (NPU), or a combination thereof. The processor 100 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device (PLD) may be a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a general purpose array logic (GAL), or any combination thereof.

[0088] The memory 200 stores instructions that can be executed by at least one processor 100, so as to enable at least one processor 100 to execute the method shown in the above embodiment.

[0089] The memory 200 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the use of a computer device based on the presentation of a small program landing page, etc. In addition, the memory 200 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 200 may optionally include a memory remotely located relative to the processor 100, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0090] The memory 200 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 200 may also include a combination of the above types of memory.

[0091] The computer device further includes a communication interface 300 for the computer device to communicate with other devices or a communication network.

[0092] The embodiment of the present invention also provides a computer-readable storage medium. The above-mentioned method according to the embodiment of the present invention can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0093] A portion of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the form in which the computer program instruction exists in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc. Accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium that can be accessed by the computer.

[0094] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A system for sensor temperature measurement and calibration based on laser heating, characterized in that: The system includes: a laser light source, a lens assembly, a temperature measurement module and a heating block; The laser light source is used to output a laser beam; The lens assembly is used to output a uniform light spot of a preset shape after adjusting the laser beam to irradiate the two symmetrical surfaces of the heated block, and the surface of the heated block has an opening of a preset shape; The heated block is used to generate a constant temperature cavity based on a uniform light spot of a preset shape, and the sensor to be calibrated is placed in the constant temperature cavity; The temperature measurement module is used to measure the temperature of the constant temperature chamber when the temperature of the constant temperature chamber changes, and calibrate the sensor to be calibrated according to the temperature.

2. The system for sensor temperature measurement and calibration based on laser heating according to claim 1, characterized in that: The lens assembly includes: a shaping assembly and a direction adjustment assembly; The shaping component is used to adjust the laser beam and output a uniform light spot of a preset shape; The direction adjustment component is used to split the uniform light spot and irradiate the two symmetrical surfaces of the heated block respectively.

3. The system for sensor temperature measurement and calibration based on laser heating according to claim 2, characterized in that: The direction adjustment component includes a beam splitter and a reflector; The beam splitter is used to split the uniform light spot into two beams; The reflecting mirror is used to irradiate the two split light spots onto two opposite surfaces of the heated block respectively.

4. The system for sensor temperature measurement and calibration based on laser heating according to claim 2, characterized in that: When the laser beam is a parallel beam of a preset shape, the shaping component includes a diffractive optical element, and the diffractive optical element is used to adjust the laser beam into a uniform light spot of the preset shape; When the laser beam is a non-parallel beam of a preset shape, the shaping component includes a collimating element and a diffractive optical element, the collimating element is used to collimate the laser beam, and the diffractive optical element is used to adjust the collimated beam into a uniform light spot of a preset shape; When the laser beam is a non-parallel beam with a non-preset shape, the shaping component includes a collimating element, a microlens array, a focusing element and a plano-concave lens. The microlens array is used to convert the laser beam collimated by the collimating element into a beam with a preset shape. The focusing element is used to focus the laser beam with a preset shape. The plano-concave lens is used to parallelize the focused laser beam and output a uniform light spot with a preset shape.

5. The system for sensor temperature measurement and calibration based on laser heating according to claim 1, characterized in that: The heated block comprises an outer layer structure and an inner layer structure; The outer layer structure has openings on three sides, wherein two symmetrical surfaces have first openings of a preset shape, the first openings are used to receive a uniform light spot of a preset shape, the opening on the third surface of the outer layer structure is used to place a laser to be calibrated, and the thermal conductivity of the outer layer structure is less than a first preset value; The thermal conductivity of the inner layer structure is greater than a second preset value, and the sensor to be calibrated is placed in the inner layer structure.

6. The system for sensor temperature measurement and calibration based on laser heating according to claim 1, characterized in that: The system also includes: a power monitoring module, a water cooler and a CNC host; the power monitoring module is used to monitor the power of the laser beam output by the laser light source; the CNC host is used to adjust the power of the laser light source based on the power and temperature to adjust the temperature of the constant temperature chamber, and the water cooler is used to cool the laser light source.

7. The system for sensor temperature measurement and calibration based on laser heating according to claim 1, characterized in that: The system further comprises: a load constant temperature control chamber, the inner wall of which is provided with refractory bricks, and the heated block is placed in the load constant temperature control chamber.

8. A method for sensor temperature measurement calibration based on laser heating, characterized in that: The system for sensor temperature measurement and calibration based on laser heating according to any one of claims 1 to 7, wherein the method comprises: Controlling the temperature of the constant temperature chamber to continuously change at a preset rate; According to the responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process, the sensor to be calibrated is dynamically calibrated; Controlling the temperature of the constant temperature chamber to be stable at a preset value; The sensor to be calibrated is statically calibrated according to the temperature measured by the temperature measurement module.

9. The method according to claim 8, characterized in that Before controlling the temperature of the constant temperature chamber to continuously change at a preset rate, the method further includes: Conduct thermodynamic simulations on heated blocks of different materials and sizes to obtain temperature rise curves and temperature distribution diagrams; The structure of the heated block is determined based on the temperature rise curve and the temperature distribution diagram.

10. A device for sensor temperature measurement and calibration based on laser heating, characterized in that: The system for sensor temperature measurement and calibration based on laser heating as described in any one of claims 1 to 7 comprises: A first control module, configured to control the temperature of the constant temperature chamber to continuously change at a preset rate; A dynamic calibration module is used to dynamically calibrate the sensor to be calibrated according to the responses of the sensor to be calibrated and the temperature measurement module at different temperature points during the temperature change process; A second control module is used to control the temperature of the constant temperature chamber to be stable at a preset value; The static calibration module is used to perform static calibration on the sensor to be calibrated according to the temperature measured by the temperature measurement module.

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