Optical-mechanical scanning thermal imager for detecting axle temperature and wheel temperature of high-speed train

Abstract

The utility model relates to railway safety monitoring, infrared thermal imaging technical field discloses a kind of optical-mechanical scanning thermal imager for high-speed train axle temperature wheel temperature detection, comprising: infrared detection structure, for detecting the infrared radiation of target and converting it into electrical signal;Signal processing subsystem, for processing electrical signal and generating temperature image;The infrared detection structure includes: optical scanning subsystem, for receiving target infrared radiation and performing high-speed scanning;Unit detection subsystem, for converting scanned infrared radiation signal into electrical signal;Sealing protective shell, inert gas is filled in its inside, for the optical scanning subsystem and unit detection subsystem provide airtight, dustproof environment.The utility model can meet the extremely fast response speed and high thermal sensitivity required by high-speed train temperature detection, while significantly reducing system cost and complexity, and improve long-term operation reliability.

Description

Technical Field

[0001] This utility model relates to the fields of railway safety monitoring and infrared thermal imaging technology. Specifically, it is an optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains. Background Technology

[0002] During high-speed train operation, the running gear (especially bearings and wheels) experiences abnormal temperature rises due to prolonged exposure to enormous loads and mechanical friction. This is a major precursor to catastrophic accidents such as axle breakage and derailment. Therefore, online, real-time, and accurate temperature detection of train bearings and wheels during high-speed operation is a crucial technical means to ensure railway transportation safety. Infrared thermal imaging technology, as a non-contact temperature measurement method, is currently the mainstream choice for achieving this function.

[0003] Currently, infrared thermal imaging technology applied in this field is mainly based on two types of detectors:

[0004] 1. Cooled Focal Plane Array Detectors: These detectors (such as cooled mercury cadmium telluride (MCT) or quantum trap infrared photon (QWIP) array detectors) possess extremely high thermal sensitivity and extremely fast response speeds (down to the microsecond level), enabling them to clearly and accurately capture the temperature field distribution of high-speed moving targets. However, cooled focal plane array detectors are extremely expensive, hindering large-scale deployment; their systems are complex, bulky, and energy-intensive, and they suffer from vibration and lifespan issues under continuous operation. In harsh environments along railway lines, their long-term operational reliability and maintenance costs pose significant challenges; furthermore, their cooling systems require a long start-up time to reach operating temperature, failing to meet the rapid response requirements for immediate power-on startup.

[0005] 2. Uncooled focal plane detectors: These detectors (such as vanadium oxide (VOx) or amorphous silicon (a-Si) microbolometers) do not require cooling devices and have advantages such as low cost, small size, low power consumption, and fast start-up. However, their thermal response time is too long. When a train passes through the detection field of view at high speed, its millisecond-level response speed has not yet formed a stable and clear signal before the train has left, resulting in the inability to obtain accurate temperature readings, blurry images, and a high risk of missing abnormal heat sources.

[0006] Therefore, current technologies present an irreconcilable contradiction regarding the above situation: high-performance cooled area array detectors are difficult to popularize due to cost and reliability issues, while lower-cost uncooled area array detectors cannot meet high-speed detection requirements due to their slow response speed. This contradiction has become a technical bottleneck restricting the further development and widespread application of railway infrared safety monitoring technology. Utility Model Content

[0007] The purpose of this invention is to provide an optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains, which solves the problem that high-performance cooled area array detectors are difficult to popularize due to cost and reliability issues, while low-cost uncooled area array detectors cannot meet the needs of high-speed detection due to slow response speed.

[0008] This utility model is achieved through the following technical solution: an optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains, comprising:

[0009] An infrared detection structure used to detect the infrared radiation of a target and convert it into an electrical signal;

[0010] The signal processing subsystem is used to process electrical signals and generate temperature images;

[0011] The infrared detection structure includes:

[0012] An optical scanning subsystem is used to receive infrared radiation from the target and perform high-speed scanning.

[0013] The unit detection subsystem is used to convert the scanned infrared radiation signal into an electrical signal;

[0014] A sealed protective housing, filled with inert gas, is used to provide an airtight and dustproof environment for the optical scanning subsystem and the unit detection subsystem.

[0015] To better realize this utility model, the optical scanning subsystem further includes an image-side telecentric lens, a micro-mirror, and a focusing lens group; the image-side telecentric lens is used to receive infrared radiation from the target within the field of view and form an initial image plane; the micro-mirror is disposed on the image-side optical path of the image-side telecentric lens and is used to perform high-speed, periodic angular oscillation around a one-dimensional or two-dimensional axis to scan and reflect the initial image plane; the focusing lens group is used to converge the scanning beam reflected by the micro-mirror to a focal point.

[0016] To better realize this utility model, the optical scanning subsystem further includes a micro-mirror drive controller for driving and controlling the micro-mirror to scan at a predetermined frequency and angle.

[0017] To better realize this utility model, the micro-vibrating mirror is further described as a one-dimensional high-speed swing mirror, whose swing direction is perpendicular to the direction of train movement. It covers the width direction of the detection field of view by scanning back and forth, and completes spatial coverage along the track direction by utilizing the movement of the train itself.

[0018] To better realize this utility model, the micro-vibrating mirror is further described as a two-dimensional high-speed oscillating mirror, which actively scans and covers a two-dimensional rectangular field of view through a composite motion in two dimensions.

[0019] To better realize this utility model, the design wavelength of the image-side telecentric lens is 3μm-5μm or 8μm-14μm.

[0020] To better realize this utility model, the unit detection subsystem further includes a detector, which is a unit-cooled MCT detector. Its photosensitive element is set at the focal point of the focusing lens group to receive the converged infrared radiation and generate a corresponding electrical signal.

[0021] To better realize this utility model, the signal processing subsystem further includes:

[0022] A preamplifier circuit, connected to the output of the detector, is used to amplify and preprocess the electrical signal;

[0023] The data acquisition unit is used to acquire amplified analog signals and convert them into digital signals.

[0024] An image processing unit is communicatively connected to the data acquisition unit and the micromirror controller. The image processing unit is configured to: receive a precise position synchronization signal from the micromirror controller; arrange the digital signals according to the spatiotemporal correspondence based on the synchronization signal and externally input train speed information to reconstruct a complete two-dimensional thermal image; perform non-uniformity correction and temperature calibration on the reconstructed thermal image, and calculate and output the final temperature data.

[0025] To better realize this utility model, the image processing unit is further configured to: identify the train wheel and bearing areas from the reconstructed thermal image, track their motion trajectory, and extract their highest temperature, average temperature, and temperature distribution.

[0026] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0027] (1) Low cost: The cost of using a single-unit MCT detector is much lower than that of a focal plane array detector, which solves the problem of excessively high cost of cooled array schemes;

[0028] (2) Fast response speed: The unit MCT detector itself has a microsecond-level response speed. Combined with high-speed micro-mirror scanning, the effective response speed of the whole system is much faster than that of the uncooled area array detector, which is perfectly adapted to the high-speed train detection scenario.

[0029] (3) High reliability: Compared with the large refrigerator of the array detector, the micro refrigerator of the unit detector has a simpler structure, smaller size, less vibration and longer life, which greatly improves the long-term operational reliability of the system in harsh outdoor environments.

[0030] (4) High precision: The use of a telecentric lens ensures uniform illumination of the image plane throughout the entire scanning field of view. Combined with the high sensitivity of the cooled MCT detector, it ensures accurate temperature measurement. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structural composition of this utility model.

[0032] Figure 2 This is a schematic diagram of the imaging detection method. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] Example 1:

[0036] This embodiment provides an optomechanical scanning thermal imager for detecting axle and wheel temperatures on high-speed trains, including:

[0037] An infrared detection structure used to detect the infrared radiation of a target and convert it into an electrical signal;

[0038] The signal processing subsystem is used to process electrical signals and generate temperature images;

[0039] The infrared detection structure includes:

[0040] An optical scanning subsystem is used to receive infrared radiation from the target and perform high-speed scanning.

[0041] The unit detection subsystem is used to convert the scanned infrared radiation signal into an electrical signal;

[0042] A sealed protective housing, filled with inert gas, is used to provide an airtight and dustproof environment for the optical scanning subsystem and the unit detection subsystem.

[0043] Example 2:

[0044] This embodiment is a further extension of the above embodiments, such as... Figure 1 As shown, the optical scanning subsystem includes an image-side telecentric lens, a micro-mirror, and a focusing lens group. The image-side telecentric lens is used to receive infrared radiation from the target within the field of view and form an initial image plane. The micro-mirror is disposed on the image-side optical path of the image-side telecentric lens and is used to perform high-speed, periodic angular oscillation around a one-dimensional or two-dimensional axis to scan and reflect the initial image plane. The focusing lens group is used to converge the scanning beam reflected by the micro-mirror to a focal point.

[0045] Furthermore, the unit detection subsystem includes a detector, which is a unit-cooled MCT detector. Its photosensitive element is located at the focal point of the focusing lens group to receive the converged infrared radiation and generate a corresponding electrical signal.

[0046] The price of a unit-cooled MCT detector is significantly lower than that of a cooled focal plane array detector. Furthermore, the unit-cooled MCT detector has a simpler structure, smaller size, less vibration, and longer lifespan, greatly improving the long-term operational reliability of the system in harsh outdoor environments. Although the response speed of the unit-cooled MCT detector is slower than that of the cooled focal plane array detector, when combined with high-speed micromirror scanning, the overall system's effective response speed is much faster than that of an uncooled area array detector, making it perfectly suited for high-speed train detection scenarios. This solves the problem that high-performance cooled area array detectors are difficult to popularize due to cost and reliability issues, while lower-cost uncooled area array detectors cannot meet high-speed detection requirements due to slow response speeds.

[0047] Furthermore, the signal processing subsystem includes:

[0048] A preamplifier circuit, connected to the output of the detector, is used to amplify and preprocess the electrical signal;

[0049] The data acquisition unit is used to acquire amplified analog signals and convert them into digital signals.

[0050] An image processing unit is communicatively connected to the data acquisition unit and the micromirror controller.

[0051] During operation, the image processing unit receives a precise position synchronization signal from the micromirror controller; then, based on the synchronization signal and the externally input train speed information, it arranges the digital signals according to the spatiotemporal correspondence to reconstruct a complete two-dimensional thermal image; next, it performs non-uniformity correction and temperature calibration on the reconstructed thermal image, calculates and outputs the final temperature data; finally, it identifies the train wheel and bearing areas from the reconstructed thermal image, tracks their movement trajectory, and extracts their highest temperature, average temperature, and temperature distribution.

[0052] The other parts of this embodiment are the same as those in the above embodiments, and will not be described again.

[0053] Example 3:

[0054] This embodiment further extends the above embodiment by including a micromirror drive controller in the optical scanning subsystem, which drives and controls the micromirror to scan at a predetermined frequency and angle.

[0055] Furthermore, the micro-mirror is a one-dimensional high-speed swing mirror, whose swing direction is perpendicular to the direction of train movement. It covers the width of the detection field of view by scanning back and forth, and completes spatial coverage along the track direction by utilizing the movement of the train itself.

[0056] Furthermore, the design wavelength of the image-side telecentric lens is 3μm-5μm or 8μm-14μm.

[0057] In another specific embodiment, the micro-mirror is a two-dimensional high-speed oscillating mirror that actively scans and covers a two-dimensional rectangular field of view through a composite motion in two dimensions.

[0058] The other parts of this embodiment are the same as those in the above embodiments, and will not be described again.

[0059] Example 4:

[0060] This embodiment provides an optomechanical scanning imaging detection method for detecting axle and wheel temperatures in high-speed trains, based on the thermal imager described in the above embodiment, such as... Figure 2 As shown, it includes the following steps:

[0061] Step S1: Control the micromirror to perform high-speed periodic scanning through the micromirror drive controller;

[0062] Step S2: The unit-cooled MCT detector receives the instantaneous infrared radiation after scanning and convergence, and converts it into a timing electrical signal;

[0063] Step S3: The data acquisition unit converts the timing electrical signal into a digital signal stream;

[0064] Step S4: The image processing unit receives a synchronization signal from the micromirror controller and associates the digital signal stream with the spatial coordinates corresponding to each data point;

[0065] Step S5: Combine the real-time speed information of the train, stitch and interpolate the coordinate data points to reconstruct a two-dimensional thermal image;

[0066] Step S6: Perform temperature calibration and abnormal temperature analysis on the two-dimensional thermal image, and output the diagnostic results.

[0067] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains, characterized in that, include: An infrared detection structure used to detect the infrared radiation of a target and convert it into an electrical signal; The signal processing subsystem is used to process electrical signals and generate temperature images; The infrared detection structure includes: An optical scanning subsystem is used to receive infrared radiation from the target and perform high-speed scanning. The unit detection subsystem is used to convert the scanned infrared radiation signal into an electrical signal; A sealed protective housing, filled with inert gas, is used to provide an airtight and dustproof environment for the optical scanning subsystem and the unit detection subsystem.

2. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 1, characterized in that: The optical scanning subsystem includes an image-side telecentric lens, a micro-mirror, and a focusing lens group. The image-side telecentric lens is used to receive infrared radiation from the target within the field of view and form an initial image plane. The micro-mirror is disposed on the image-side optical path of the image-side telecentric lens and is used to perform high-speed, periodic angular oscillation around a one-dimensional or two-dimensional axis to scan and reflect the initial image plane. The focusing lens group is used to converge the scanning beam reflected by the micro-mirror to a focal point.

3. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 2, characterized in that: The optical scanning subsystem also includes a micromirror drive controller for driving and controlling the micromirror to scan at a predetermined frequency and angle.

4. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 3, characterized in that: The micro-mirror is a one-dimensional high-speed swing mirror, whose swing direction is perpendicular to the direction of train movement. It covers the width of the detection field of view by scanning back and forth, and completes spatial coverage along the track direction by utilizing the movement of the train itself.

5. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 2, characterized in that: The micro-mirror is a two-dimensional high-speed oscillating mirror that actively scans and covers a two-dimensional rectangular field of view through a composite motion in two dimensions.

6. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 2, characterized in that: The design wavelength of the image-side telecentric lens is 3μm-5μm or 8μm-14μm.

7. A photomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to any one of claims 2-6, characterized in that: The unit detection subsystem includes a detector, which is a unit-cooled MCT detector. Its photosensitive element is set at the focal point of the focusing lens group to receive the converged infrared radiation and generate a corresponding electrical signal.

8. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 7, characterized in that: The signal processing subsystem includes: A preamplifier circuit, connected to the output of the detector, is used to amplify and preprocess the electrical signal; The data acquisition unit is used to acquire amplified analog signals and convert them into digital signals. An image processing unit is communicatively connected to the data acquisition unit and the micromirror controller. The image processing unit is configured to: receive a precise position synchronization signal from the micromirror controller; arrange the digital signals according to the spatiotemporal correspondence based on the synchronization signal and externally input train speed information to reconstruct a complete two-dimensional thermal image; perform non-uniformity correction and temperature calibration on the reconstructed thermal image, and calculate and output the final temperature data.

9. The optomechanical scanning thermal imager for detecting axle and wheel temperatures of high-speed trains according to claim 8, characterized in that: The image processing unit is also configured to identify the train wheel and bearing areas from the reconstructed thermal image, track their motion trajectory, and extract their highest temperature, average temperature, and temperature distribution.

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