Tdr technology-based air induction system overheating detection loop detection device and system
By using a TDR-based overheat detection loop testing device for the bleed air system, and utilizing a transfer computer and parameter database, the overheat detection loop of the aircraft's bleed air system can be located accurately and without disassembly. This solves the problems of low efficiency and structural damage of existing TDR equipment in aircraft inspection, and improves maintenance efficiency and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 黄栋梁
- Filing Date
- 2026-04-21
- Publication Date
- 2026-07-17
AI Technical Summary
Existing TDR equipment cannot be directly applied to the overheat detection loop of the aircraft bleed air system. It suffers from problems such as large blind zone, impedance mismatch, and lack of aircraft model database, resulting in low detection efficiency and easy damage to the aircraft structure.
A TDR-based overheat detection loop detection device for an air bleed system is provided, comprising a transfer computer, a display, and a parameter database. It is electrically connected to the air bleed system through a universal interface module, transmits TDR signals to locate fault points, and uses the parameter database to obtain the names of faulty components, achieving accurate location without disassembling the aircraft structure.
It significantly improves the efficiency of troubleshooting overheating detection loop faults in aircraft bleed air systems, enabling rapid and accurate location of faulty components, and enhancing maintenance efficiency and safety.
Smart Images
Figure CN122402803A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to aircraft maintenance and inspection technology, and more particularly to a detection device and system for an overheat detection loop of a bleed air system based on TDR technology. Background Technology
[0002] The bleed air system overheat detection loop is a crucial safety component in civil aircraft, used to monitor bleed air lines in areas such as the wings, pylons, and APU for leaks or overheating. When the detection loop detects an abnormal temperature rise, the Bleed Monitoring Computer (BMC) triggers a cockpit warning, allowing the pilot to promptly close the bleed air valves and prevent high-temperature air from damaging surrounding structures or causing a fire. Therefore, the functionality of the detection loop is directly related to flight safety. Traditional overheat detection loop methods primarily rely on DC resistance measurements, which have the following drawbacks: they can only determine if the entire loop is functioning correctly, but cannot precisely pinpoint the location of the fault; and when an abnormal resistance value is detected, manual disassembly and inspection of each section is still required, which is inefficient and can easily damage the aircraft structure.
[0003] Time Domain Reflectometry (TDR) technology enables precise, non-disassembly-based fault location in cables by injecting high-frequency pulses into transmission lines and analyzing the reflected signals. However, existing TDR equipment is mostly designed for the communications and power industries, lacking dedicated detection equipment for aircraft bleed air system overheat detection loops. Aircraft overheat detection loops are characterized by short distances (typically less than 20 meters), non-standard impedance, and significant aircraft model differences. General-purpose TDR equipment suffers from large blind zones, impedance mismatches, and a lack of aircraft model databases, making it unsuitable for direct application in aviation maintenance scenarios.
[0004] Therefore, there is an urgent need for an aviation-specific detection system based on TDR technology to achieve non-disassembly, precise location and intelligent identification of overheat detection loop faults. Summary of the Invention
[0005] Based on this, the purpose of this application is to provide a TDR-based overheat detection loop detection system and equipment for bleed air systems, which can quickly and accurately locate the fault location and identify the faulty component during aircraft bleed air system maintenance, thus significantly improving maintenance efficiency.
[0006] The objective of this application can be achieved through the following technical solutions:
[0007] In a first aspect, embodiments of this application provide a detection device for an overheat detection loop in an exhaust gas system based on TDR technology, characterized in that it includes a transfer computer, a display, and a parameter database; wherein, the transfer computer includes a general interface module, a TDR signal generation module, a TDR signal receiving module, and a data processing module; the parameter database stores parameters and distance-element name mapping relationships for various types of overheat detection loops, and the parameters include the wave velocity ratio of each type of overheat detection loop; The adapter computer is installed at the location of the bleed air monitoring computer of the bleed air system under test, and is electrically connected to the bleed air system under test through the general interface module; The TDR signal generating module transmits a TDR signal to the overheat detection loop of the bleed air system under test through the general interface module. The TDR signal receiving module receives the test signal returned by the overheat detection loop under test through the general interface module. The data processing module locates the fault point based on the test signal and the wave velocity ratio of the overheat detection loop under test in the parameter database, and obtains the component name of the fault point according to the distance-component name of the overheat detection loop under test in the parameter database. The module then controls the display to show the test signal and the component name of the fault point.
[0008] Secondly, embodiments of this application provide a TDR-based overheat detection loop detection system for an air intake system, including an overheat detection loop detection device for an air intake system based on TDR technology as described above, and a cloud server for receiving and storing the signal to be detected and the component name of the fault point.
[0009] Compared to existing technologies, the method described in this application involves installing a transfer computer at the location of the bleed air monitoring computer of the bleed air system under test. The transfer computer is electrically connected to the bleed air system under test via a universal interface module. The TDR signal generation module of the transfer computer then transmits a TDR signal to the overheat detection loop under test to locate the fault point. The name of the faulty component corresponding to the fault point is then obtained according to the distance-component name mapping table in the parameter database. This method enables maintenance personnel to quickly and accurately locate the faulty component without disassembling the aircraft structure, significantly improving maintenance efficiency.
[0010] To better understand and implement this application, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description
[0011] The accompanying drawings, which are included to provide a further understanding of the embodiments of this application and constitute a part of the embodiments of this application, are illustrative embodiments of this application and their descriptions are used to explain the embodiments of this application, and do not constitute an improper limitation on the embodiments of this application.
[0012] Figure 1yes Figure 1 This application provides a schematic diagram of a detection device for an overheating detection loop in an air bleed system based on TDR technology. Figure 2 This is a schematic diagram of the transfer computer structure of an overheat detection loop detection device for an air bleed system based on TDR technology, provided in an embodiment of this application. Figure 3 This application provides a display interface for an overheat detection loop detection device for an air bleed system based on TDR technology. Figure 4 This is a schematic diagram of the working process of an overheat detection loop detection device for an air bleed system based on TDR technology, provided in an embodiment of this application. Figure 5 This is a schematic diagram illustrating the workflow of the transfer computer data processing module in this application for locating fault points and obtaining the names of faulty components. Figure 6 This is a schematic diagram of the workflow of the data processing module of the transfer computer in this application for identifying the fault type of the fault point. Detailed Implementation
[0013] This application provides a detection system and device for overheating detection loop of an expiratory air system based on TDR technology. To make the objectives, technical solutions, and effects of this application clearer and more explicit, the following detailed description is provided with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit this application.
[0014] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. The singular forms "a," "the," and "the" used in this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. The word "if" as used herein can be interpreted as "when," "when," or "in response to determination."
[0015] Those skilled in the art will understand that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein. Furthermore, the terms "aircraft" or "airplane" as used in the following description have the same meaning as "civil aircraft".
[0016] The invention will be further explained below with reference to the accompanying drawings and the description of the embodiments.
[0017] Please see Figure 1 , Figure 1 This application provides a schematic diagram of a detection device for an overheating detection loop in a bleed air system based on TDR technology, including a transfer computer 100, a display 200, and a parameter database 300. In this embodiment, the transfer computer 100 and the display 200 are connected wirelessly. In this embodiment, the parameter database 300 is stored on the transfer computer 100; in other alternative embodiments, the parameter database 300 may also be stored on the display 200.
[0018] Please see Figure 2 , Figure 2 This is a schematic diagram of the transfer computer structure of an overheat detection loop detection device for an exhaust gas system based on TDR technology, provided in an embodiment of this application. The transfer computer 100, as the core detection unit, includes a general interface module 110, a TDR signal generation module 120, a TDR signal receiving module 130, and a data processing module 140. Optionally, the transfer computer 100 also includes a cloud communication module 150 for uploading the detection results to a cloud server, a wireless network module 160 for wireless communication with the display 200, and a power supply module 170 for boosting power.
[0019] The adapter computer 100 adopts a portable chassis design. During the maintenance of civil aircraft, the bleed air monitoring computer (BMC) is usually temporarily removed. In this embodiment, the adapter computer 100 is electrically connected to the bleed air system to be maintained through a universal interface module 110. By utilizing the aircraft's existing wiring to access each overheat detection loop, it is possible to achieve accurate TDR detection without disassembling the aircraft structure. This avoids the inefficiency and damage risks caused by the repeated plugging and unplugging of jumpers or disassembly of the aircraft structure in traditional methods. It enables rapid multi-loop detection with only a single installation, significantly improving the efficiency and safety of aviation maintenance operations.
[0020] The universal interface module 110 employs mechanical and electrical interfaces fully compatible with the bleed air monitoring computer of the bleed air system under test, and supports hot-swapping. This enables a quick and reliable electrical connection between the adapter computer 100 and the civil aircraft bleed air system, eliminating the need for additional adapter installation or wiring modifications, resulting in higher testing efficiency in line maintenance or scheduled inspection scenarios. The interface type of the universal interface module 110 is adjusted accordingly for different aircraft models.
[0021] The TDR signal generation module 120 is used to generate and transmit TDR pulse signals. The TDR signal generation module 120 includes a pulse generator, a time base circuit, and an output drive circuit, and is capable of generating high-frequency pulse signals with a rise time of less than 1 nanosecond. In one embodiment, the frequency of the TDR signal transmitted by the TDR signal generation module can be adjusted according to the requirements of different overheat detection loops under test, with the adjustable frequency range of the TDR signal being between 1MHz and 100MHz.
[0022] The TDR signal receiving module 130 is used to receive the test signal returned from the overheat detection loop. The TDR signal receiving module 130 includes a high-speed sampling circuit, a signal conditioning circuit, and an analog-to-digital conversion circuit, with a sampling rate of not less than 10 GSa / s to ensure accurate capture of the test signal waveform at the nanosecond level.
[0023] The data processing module 140, as the core computing unit, can be implemented using an embedded processor, DSP, or FPGA, and is used to process, analyze, and locate faults in the signals under test.
[0024] The parameter database 300 stores parameters and distance-element name mappings for various types of overheat detection loops for each aircraft model. Among the parameters are the beam velocity ratios of each type of overheat detection loop, i.e., the ratio of the TDR signal propagation speed in the loop to the speed of light, typically between 0.6 and 0.8. The distance-element name mapping records the correspondence between the electrical distance to each detection element and its element number along the overheat detection loop from the detection end. For example, for the A-loop of the left wing of the A320 aircraft, the mapping can be expressed as: 0-2.3m corresponds to element 1, 2.3-4.6m corresponds to element 2, and so on until all elements are identified.
[0025] Please refer to Figure 3 , Figure 3This application provides a display interface for a TDR-based overheat detection loop testing device for a bleed air system. The display 200 can be an LCD screen or a touch screen, displaying the waveform of the signal under test and the name of the faulty component in real time. "L WING LOOP A" indicates the overheat detection loop under test. The horizontal axis of the waveform is the distance from the transfer computer (feet), and the vertical axis is the amplitude of the signal under test (volts). In one embodiment, fault type information can also be displayed for maintenance personnel to interpret intuitively.
[0026] Please see Figure 4 , Figure 4 This is a schematic diagram of the working steps of an overheat detection loop detection device for an air intake system based on TDR technology, according to an embodiment of this application.
[0027] S100: During testing, the Bleed Air Monitoring Computer (BMC) connected to the Bleed Air System under test on the aircraft is temporarily removed, and the adapter computer 100 is installed at the location of the Bleed Air Monitoring Computer of the Bleed Air System under test, and electrically connected to the Bleed Air System under test through the general interface module 110.
[0028] S200: The TDR signal generation module 120 transmits a TDR signal to the overheat detection loop of the air intake system under test through the general interface module 110.
[0029] When a TDR signal propagates along the loop, it will generate a reflected signal at the impedance discontinuity point (such as a fault point, connector, or detection element).
[0030] S300: The TDR signal receiving module 130 receives the test signal returned by the overheat detection loop through the general interface module 110.
[0031] The signal under test refers to the raw electrical signal received by the TDR signal receiving module from the overheat detection loop under test through the general interface module. The signal under test includes the flat signal received when there is no fault, i.e., the baseline, and the reflected signal generated by the impedance change at the fault point; the reflected signal is manifested as a reflection peak superimposed on the baseline, and the amplitude change value of the reflection peak (i.e., the amplitude of the reflected signal) is used for subsequent calculation of the reflection coefficient and the impedance at the fault point.
[0032] S400: Data processing module 140 locates the fault point based on the wave velocity ratio of the overheat detection loop under test in the database of signals and parameters 300.
[0033] In one embodiment, see Figure 5 , Figure 5 This is a schematic diagram illustrating the workflow of the transfer computer data processing module in this application for locating fault points and obtaining the names of faulty components.
[0034] S410: Obtain the wave velocity ratio of the overheat detection loop to be tested based on parameter database 300.
[0035] The parameter database 300 stores parameters and distance-component name mappings for different types of overheat detection loops across different models. The data processing module 140 retrieves the wave velocity ratio of the overheat detection loop under test from the parameter database 300 based on the model and loop number. Due to differences in insulation materials and structure, the wave velocity ratios of cables from different models and batches of overheat detection loops vary; accurately obtaining the corresponding wave velocity ratio is a prerequisite for accurate positioning.
[0036] S420: Preprocesses the waveform of the signal under test to identify reflection peaks in the waveform; reflection peaks are regions where the amplitude of the signal under test changes abruptly, and the point with the largest amplitude change within the reflection peak is taken as the fault point.
[0037] The test signal acquired by the TDR signal receiving module 130 is preprocessed. The preprocessing steps include filtering and noise reduction, baseline correction, and normalization to eliminate the effects of high-frequency noise and system drift. After preprocessing the baseline signal, regions with abrupt amplitude changes in the test signal are identified. These amplitude changes include steep abrupt changes and gradual changes; any significant deviation of the test signal amplitude from the baseline corresponds to the location of cable impedance discontinuity, i.e., the fault point.
[0038] S430: Based on the time difference between the transmission time of the TDR signal emitted by the TDR signal generator and the reception time of the fault point received by the TDR signal receiving module, as well as the wave velocity ratio, the fault point is located, and the distance between the fault point and the transfer computer is obtained.
[0039] In one embodiment, the transmission time of the TDR signal transmitted by the TDR signal generating module 120 is recorded as T1, and the reception time of the fault point signal received by the TDR signal receiving module 130 is recorded as T2. The time difference is calculated. .
[0040] The data processing module multiplies the wave velocity ratio by the speed of light, then multiplies by the time difference; half of this product is the distance between the fault point and the transfer computer. The calculation formula is:
[0041] in, The wave velocity ratio is the ratio of the propagation speed of the TDR signal in the overheat detection loop under test to the speed of light. The speed of light in a vacuum The time difference between the transmission time of the TDR signal and the reception time of the fault point signal of the TDR signal. This refers to the distance between the fault location and the transfer computer.
[0042] S440: Calculated distance Query the distance-component name mapping relationship stored in the parameter database to obtain the component name corresponding to the distance, and then obtain the component name of the fault point.
[0043] S500: Data processing module 140 controls display 200 to display the waveform of the signal under test and the component name of the fault point.
[0044] Maintenance personnel can intuitively see the location of the fault and the specific component name, such as "Detection Component No. 7 of the A Ring Road on the Left Wing".
[0045] Compared to existing technologies, the method described in this application replaces the bleed air monitoring computer of the bleed air system with a transfer computer during maintenance. The transfer computer then sends a TDR signal to the overheat detection loop under inspection to locate the fault point. The name of the faulty component corresponding to the fault point is obtained according to the distance-component name mapping table in the parameter database. This allows maintenance personnel to quickly and accurately locate the faulty component without disassembling the aircraft structure, significantly improving maintenance efficiency.
[0046] In one embodiment, the parameter database also includes characteristic impedance reference values for each type of overheat detection loop; the data processing module identifies the fault type of the fault point based on the signal to be tested and the characteristic impedance reference values of the overheat detection loop to be tested.
[0047] The characteristic impedance reference value is the standard impedance of the overheat detection loop under normal operating conditions. It is determined by the cable structure (conductor diameter, insulation material, shielding layer) and is usually between 50Ω and 150Ω.
[0048] In one embodiment, see Figure 6 , Figure 6 This is a schematic diagram of the workflow of the data processing module of the transfer computer in this application for identifying the fault type of the fault point.
[0049] S450: Obtain the characteristic impedance reference value of the overheat detection loop to be tested from the parameter database.
[0050] S460: Preprocesses the waveform of the signal under test and identifies the reflection peak in the waveform of the signal under test; the reflection peak is the region where the amplitude of the signal under test changes abruptly, and the point with the largest amplitude change in the reflection peak is taken as the fault point, and the amplitude change value of the fault point is extracted.
[0051] When the TDR signal propagates in the transmission line of the overheat detection loop, if the characteristic impedance of the transmission line is uniform everywhere, the pulse signal will propagate to the end of the loop without reflection. At this time, the test signal received by the TDR signal receiving module is a flat baseline. In this embodiment, taking the presence of a fault point in the overheat detection loop as an example, when the TDR signal propagates on the loop transmission line, the impedance changes at the fault point, which will generate a reflected signal at that point, causing the test signal received by the TDR signal receiving module to have a reflection peak. The amplitude and polarity of this additional reflected signal are related to the magnitude and direction of the impedance change. The reflection peak is the region where the amplitude of the test signal received by the TDR receiving module changes abruptly. In this embodiment, the meaning of amplitude change includes steep changes and gradual changes, that is, any significant deviation of the amplitude of the test signal from the baseline.
[0052] Specifically, the amplitude change value of the fault point is extracted, that is, the amplitude of the deviation of the fault point from the baseline, which is also the voltage amplitude of the reflected signal generated due to the fault point. Let the characteristic impedance reference value of the overheat detection loop to be tested be... The impedance at the fault point is When the transmitted pulse reaches the fault point, the voltage amplitude of the reflected signal generated at the fault point... Amplitude of the transmitted TDR signal The relationship between the two is determined by the reflection coefficient. Decide:
[0053] in, The amplitude of the transmitted TDR signal, The amplitude of the reflected signal generated at the fault point is obtained directly by reading the offset of the fault point relative to the baseline in the signal under test.
[0054] The reflection coefficient Γ ranges from -1 to +1. From this formula, we can see that: when = Time (no fault), = 0, = 0, no reflected signal; when < When (the impedance at the fault point decreases), <0, If the value is negative, the polarity of the reflected signal is negative (the waveform dips downwards). when > When (the impedance at the fault point increases), >0, If the value is positive, the polarity of the reflected signal is positive (the waveform bulges upward).
[0055] Therefore, the polarity and amplitude of the reflected signal generated at the fault point reflect the direction (increase or decrease) of the impedance change at the impedance change point on the overheat detection loop and the degree of impedance change, respectively.
[0056] S470: Based on the amplitude of the transmitted TDR signal from the TDR signal generation module. , amplitude change value at the fault point The characteristic impedance reference value of the overheat detection loop under test Identify the fault type at the fault point.
[0057] Based on the amplitude of the transmitted TDR signal The amplitude change value of the fault point Calculate the reflection coefficient Then, based on the aforementioned reflection coefficient With the aforementioned characteristic impedance reference value Calculate the impedance at the fault point Based on the impedance of the fault point With characteristic impedance reference value The comparison results are used to identify the fault type of the fault point.
[0058] In one embodiment, the data processing module inputs the amplitude of the transmitted TDR signal, the amplitude change value of the fault point, and the characteristic impedance reference value of the overheat detection loop under test into a preset fault type identification model to obtain the fault type of the fault point; wherein, the fault type identification model is trained by a machine learning method; the fault types include open circuit, short circuit, and poor contact.
[0059] The preset fault type identification model is a classification model pre-trained based on machine learning methods. The feature vector of the training samples used to train this fault type identification model consists of the amplitude of the transmitted TDR signal, the amplitude change value at the fault point, and the characteristic impedance reference value. The sample label is the corresponding fault type.
[0060] In actual testing, the data processing module uses the amplitude of the transmitted TDR signal, the amplitude change value of the fault point, and the characteristic impedance reference value of the overheat detection loop under test as input features to the preset fault type identification model. The fault type identification model outputs the fault type, including open circuit, short circuit, and poor contact.
[0061] In one embodiment, the TDR signal generation module sequentially transmits TDR signals to multiple overheat detection loops connected to the adapter computer for detection.
[0062] The adapter computer is electrically connected to multiple detection loops simultaneously via a universal interface module. During testing, the data processing module controls the TDR signal generation module to automatically switch detection channels, sequentially transmitting TDR signals to each loop, collecting the reflected signals from each loop, and locating the fault. The test results of all loops are displayed uniformly on the monitor.
[0063] Based on the technical solution of this embodiment, there is no need to repeatedly disassemble and reassemble the equipment when measuring different loops, which greatly improves the detection efficiency of multi-channel overheat detection loops.
[0064] In summary, this application replaces the bleed air monitoring computer of the bleed air system with a transfer computer during maintenance. The transfer computer then sends a TDR signal to the overheat detection loop under inspection to locate the fault point. The faulty component name corresponding to the fault point is obtained according to the distance-component name mapping table in the parameter database. This allows maintenance personnel to quickly and accurately locate the faulty component without disassembling the aircraft structure, significantly improving maintenance efficiency.
[0065] A second aspect of this application provides a TDR-based overheat detection loop detection system for an air intake system, characterized in that it includes an overheat detection loop detection device for an air intake system based on TDR technology as described above, and a cloud server for receiving and storing the signal to be detected and the component name of the fault point.
[0066] The specific examples described above further illustrate the purpose, technical solution, and beneficial effects of this application. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
[0067] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications, equivalent substitutions, and improvements without departing from the concept of the present invention, all of which fall within the protection scope of the present invention.
Claims
1. A detection device for overheating detection loop of an exhaust gas system based on TDR technology, characterized in that, It includes a switching computer, a display, and a parameter database; wherein, the switching computer includes a general interface module, a TDR signal generation module, a TDR signal receiving module, and a data processing module; the parameter database stores the parameters of various types of overheat detection loops and the distance-component name mapping relationship, and the parameters include the wave velocity ratio of each type of overheat detection loop; The adapter computer is installed at the location of the bleed air monitoring computer of the bleed air system under test, and is electrically connected to the bleed air system under test through the general interface module; The TDR signal generating module transmits a TDR signal to the overheat detection loop of the bleed air system under test through the general interface module. The TDR signal receiving module receives the test signal returned by the overheat detection loop under test through the general interface module. The data processing module locates the fault point based on the test signal and the wave velocity ratio of the overheat detection loop under test in the parameter database, and obtains the component name of the fault point according to the distance-component name of the overheat detection loop under test in the parameter database. The module then controls the display to show the test signal and the component name of the fault point.
2. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 1, characterized in that, The data processing module obtains the wave velocity ratio of the overheat detection loop under test according to the parameter database; preprocesses the waveform of the signal under test to identify the reflection peak in the waveform of the signal under test; the reflection peak is the region of abrupt change in amplitude of the signal under test, and the point with the largest amplitude change in the reflection peak is taken as the fault point; the fault point is located according to the time difference between the transmission time of the TDR signal generator and the reception time of the fault point by the TDR signal receiving module, and the wave velocity ratio, and the distance between the fault point and the transfer computer is obtained; according to the calculated distance, the distance-component name mapping relationship stored in the parameter database is queried to obtain the component name corresponding to the distance, and the component name of the fault point is obtained.
3. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 2, characterized in that, The data processing module multiplies the wave velocity ratio by the speed of light and then multiplies it by the time difference. Half of the product is the distance between the fault point and the transfer computer. The wave velocity ratio is the ratio of the propagation speed of the TDR signal in the overheat detection loop to the speed of light.
4. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 1, characterized in that, The switching computer also includes a cloud communication module, used to upload the signal to be tested and the component name of the fault point to the cloud server.
5. The overheat detection loop detection device for a bleed air system based on TDR technology according to claim 1, characterized in that, The parameter database also includes characteristic impedance reference values for various types of overheat detection loops; the data processing module identifies the fault type of the fault point based on the signal to be tested and the characteristic impedance reference values of the overheat detection loop to be tested.
6. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 5, characterized in that, The data processing module obtains the characteristic impedance reference value of the overheat detection loop under test according to the parameter database; preprocesses the waveform of the signal under test to identify the reflection peak in the waveform of the signal under test; the reflection peak is the region of abrupt change in amplitude of the signal under test, and the point with the largest amplitude change in the reflection peak is taken as the fault point, and the amplitude change value of the fault point is extracted; based on the amplitude of the transmitted TDR signal of the TDR signal generation module, the amplitude change value of the fault point, and the characteristic impedance reference value of the overheat detection loop under test, the fault type of the fault point is identified.
7. The overheat detection loop detection device for a bleed air system based on TDR technology according to claim 6, characterized in that, The data processing module inputs the amplitude of the transmitted TDR signal from the TDR signal generation module, the amplitude change value of the fault point, and the characteristic impedance reference value of the overheat detection loop under test into the preset fault type identification model to obtain the fault type of the fault point; wherein, the fault type identification model is trained based on machine learning methods; the fault types include open circuit, short circuit, and poor contact.
8. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 1, characterized in that, The TDR signal generation module sequentially transmits TDR signals to multiple overheat detection loops connected to the transfer computer for detection.
9. The overheat detection loop detection device for an exhaust gas system based on TDR technology according to claim 1, characterized in that, The TDR signal emitted by the TDR signal generation module adjusts the frequency of the TDR signal according to the requirements of different overheat detection loops under test. The adjustment frequency range of the TDR signal is between 1MHz and 100MHz.
10. A detection system for overheating detection loops in an exhaust gas system based on TDR technology, characterized in that, It includes the overheat detection loop detection device for the bleed air system based on TDR technology as described in claim 1, and a cloud server for receiving and storing the signal to be detected and the component name of the fault point.