Test system and method for fault diagnosis of thermal control assembly of high-altitude engine
By collecting resistance and current values in the high-altitude engine thermal control component fault diagnosis system and combining them with the temperature rise rate for multivariate fusion fault diagnosis, the problems of insufficient timeliness of fault diagnosis and reliability of redundancy switching in the existing technology are solved, and rapid and reliable fault identification and switching control are realized.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN AEROSPACE YUANZHENG FLUID CONTROL
- Filing Date
- 2026-01-19
- Publication Date
- 2026-06-05
AI Technical Summary
Existing fault diagnosis technologies for high-altitude engine thermal control components suffer from poor timeliness of fault diagnosis, poor reliability of redundancy switching, inability to effectively identify faults in electric heaters and sensors, and the inability to achieve real-time fault diagnosis and control with multi-redundancy.
By employing an analog signal acquisition module, a processor module, and a digital signal output module, combined with a temperature sensor and an electric heater, and by acquiring resistance and current values, a multivariate fusion fault diagnosis method is executed to achieve closed-loop temperature control and redundant switching control. Hot backup and cold backup modes are used to improve the timeliness and reliability of diagnosis.
It achieves timely fault diagnosis and reliable redundancy switching, with fault diagnosis as fast as milliseconds, ensuring task continuity and system stability, and improving the reliability of the thermal control process and the flexibility of the system.
Smart Images
Figure CN122151805A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fault diagnosis technology for thermal control components of high-altitude engines, and particularly to a test system and method for fault diagnosis of thermal control components of high-altitude engines. Background Technology
[0002] When liquid rocket high-altitude engines participate in spaceflight missions, they only ignite and operate when the spacecraft changes its orbital altitude or decelerates. For most of their time in orbit, the engines are in a non-operational state, exposed to the cryogenic environment of space for extended periods. This results in very low engine surface temperatures and component temperatures, potentially leading to propellant freezing or non-metallic component failure. Thermal control components are required to maintain the temperatures of the engine's propellant and non-metallic components within specified ranges, achieving precise temperature control of specific engine parts. During engine development, ground tests using experimental systems are necessary to address potential failures of the thermal control components during these tests.
[0003] The main problems with the current test system are: the test system only uses the collected temperature to determine the faults of the electric heater and sensor. Although it has a certain redundancy switching capability between the main and backup circuits, this method of using only temperature as a control feedback variable cannot use the physical quantities of the thermal control components' own working state to participate in fault diagnosis. It is an indirect diagnosis method, which has a lag in identifying the existence of faults and causes false alarms. In addition, the test system can only operate in a single-channel time-sharing manner. For multi-redundant real-time fault diagnosis and control systems, there is no effective solution yet.
[0004] In the prior art, Chinese patent CN117074025A discloses a space engine fault diagnosis method and system. The method includes: obtaining the diagnostic conditions of the primary thermistor; when the temperature of the primary thermistor meets the suitable temperature threshold, performing a first-level diagnosis corresponding to the start-up heating threshold; when the temperature of the primary thermistor meets the start-up heating threshold, performing a second-level diagnosis corresponding to the heating fault threshold; determining whether the primary and backup circuits need to be heated simultaneously based on the second-level diagnosis; and stopping the heating when the temperature of the primary thermistor meets the stop-heating threshold.
[0005] However, the aforementioned existing technologies have not studied or solved the above problems, resulting in poor timeliness of fault diagnosis and poor reliability of redundancy switching. Summary of the Invention
[0006] This application provides a test system and method for fault diagnosis of thermal control components of high-altitude engines, in order to solve the problems of poor timeliness of fault diagnosis and poor reliability of redundancy switching in existing fault diagnosis technologies for thermal control components of high-altitude engines.
[0007] On the one hand, this application provides a test system for fault diagnosis of thermal control components of high-altitude engines, including: an analog signal acquisition module, a processor module, a digital signal output module and several temperature control units, each temperature control unit including two temperature sensors and two electric heaters.
[0008] The analog signal acquisition module and the digital signal output module are both connected to the processor module. The temperature sensor and the electric heater are both connected to the analog signal acquisition module. The electric heater is also connected to the digital signal output module.
[0009] The analog signal acquisition module is configured to acquire the resistance signal of the temperature sensor and the current signal of the electric heater, convert them into digital signals of resistance and current, and then send them to the processor module.
[0010] The processor module is configured to: calculate the temperature value of the temperature sensor based on the resistance value, execute a temperature closed-loop control strategy according to the temperature value, and output a heating control signal to the digital output module.
[0011] The processor module is further configured to: perform a multivariate fusion fault diagnosis method based on the resistance value, the current value, and the temperature rise rate to obtain a fault diagnosis result; perform a redundancy switching control method based on the fault diagnosis result; and output a redundancy switching control signal to the digital output module.
[0012] The digital output module is configured to control the electric heater according to the heating control signal and the redundancy switching control signal.
[0013] In one possible implementation, each temperature control unit has two temperature sensors, referred to as the temperature control sensor and the temperature measurement sensor, which perform temperature measurement simultaneously, thus adopting a hot backup mode.
[0014] The two electric heaters are designated as the main electric heater and the backup electric heater. When heating is required, the main electric heater performs the heating operation. When the main electric heater fails, the backup electric heater takes over the heating operation, which is a cold backup mode.
[0015] In one possible implementation, the execution of the temperature closed-loop control strategy based on the temperature value includes: The temperature value corresponding to the temperature control sensor is compared with the preset upper and lower limits of the target temperature.
[0016] When the temperature value corresponding to the temperature control sensor is lower than the lower limit of the target temperature, the heating control signal controls the main electric heater to start heating.
[0017] When the temperature value corresponding to the temperature control sensor is higher than the upper limit of the target temperature, the heating control signal controls the main electric heater to stop heating.
[0018] When the temperature value corresponding to the temperature control sensor is within the range of the upper and lower limits of the target temperature, it is determined that the main electric heater is in normal working condition.
[0019] In one possible implementation, the parameters of each temperature control unit are configured individually, including: target temperature upper and lower limit parameters, temperature sensor fault diagnosis parameters, and electric heater fault diagnosis parameters.
[0020] In one possible implementation, the multivariate fusion fault diagnosis method includes: The temperature sensor is determined to be faulty based on the resistance value and the rate of temperature rise.
[0021] The electric heater is determined to be faulty based on the current value.
[0022] In one possible implementation, determining whether the temperature sensor is faulty based on the resistance value and the temperature rise rate includes: The resistance value is compared with the preset upper and lower resistance limits. If the resistance value is not within the range of the upper and lower resistance limits, the corresponding temperature sensor is determined to be faulty.
[0023] The temperature rise rate is defined as the amount of temperature rise within the monitoring period.
[0024] When the resistance value is within the upper and lower limits of the resistance, the temperature rise is compared with the preset temperature rise. If the temperature rise of both temperature sensors is greater than the preset temperature rise, it is determined that both temperature sensors are normal. If the temperature rise of both temperature sensors is less than the preset temperature rise, it indicates that the electric heater power is insufficient. If the temperature rise of the two temperature sensors is greater than and less than the preset temperature rise respectively, it is determined that the temperature sensor corresponding to the temperature rise less than the preset temperature rise is faulty.
[0025] In one possible implementation, determining whether the electric heater is faulty based on the current value includes: The current value is compared with the preset upper and lower current limits. If the current value is not within the range of the upper and lower current limits, the electric heater is determined to be faulty. If the current value is within the range of the upper and lower current limits, the electric heater is determined to be normal.
[0026] In one possible implementation, the redundancy switching control method includes: Condition a: If the main circuit electric heater and temperature control sensor are normal, but the temperature sensor is faulty, maintain the existing control strategy and determine that the temperature sensor is faulty.
[0027] Condition b: If the main electric heater and temperature sensor are normal, but the temperature control sensor is faulty, switch the temperature sensor to a new temperature control sensor and determine that the original temperature control sensor is faulty.
[0028] Condition c: If the temperature control sensor and temperature measurement sensor are normal, but the main circuit electric heater is faulty, switch the backup circuit electric heater to the new main circuit electric heater, and determine that the original main circuit electric heater is faulty.
[0029] Under condition d, if either the temperature control sensor or the temperature measurement sensor fails, or the main electric heater fails, the backup electric heater will be switched to the new main electric heater, and the original main electric heater will be determined to be faulty. Then, redundancy switching control will continue according to condition a or condition b.
[0030] Condition e: If both the temperature control sensor and the temperature measurement sensor are faulty, stop powering the electric heater.
[0031] Condition f: If both the main circuit electric heater and the backup circuit electric heater fail, stop supplying power to the electric heaters.
[0032] In one possible implementation, the processor module is further configured to pre-set faults for one or more temperature sensors and electric heaters to simulate faults in the thermal control components of a high-altitude engine during the test.
[0033] On the other hand, this application provides a method for using the above-mentioned test system for fault diagnosis of high-altitude engine thermal control components, including the following steps: Step 1: Collect the resistance signal from the temperature sensor and the current signal from the electric heater, and convert them into digital resistance and current signals.
[0034] Step 2: Calculate the temperature value of the temperature sensor based on the resistance value, execute the temperature closed-loop control strategy according to the temperature value, and output the heating control signal.
[0035] Step 3: Based on the resistance value and the current value, and combined with the temperature rise rate, execute the multivariate fusion fault diagnosis method to obtain the fault diagnosis result. Then, execute the redundancy switching control method according to the fault diagnosis result and output the redundancy switching control signal.
[0036] Step four: Control the electric heater according to the heating control signal and the redundancy switching control signal.
[0037] The test system and method for fault diagnosis of thermal control components of high-altitude engines in this application have the following advantages: By employing multivariate fusion fault diagnosis based on resistance, current, and temperature rise rate, the timeliness of fault diagnosis and the reliability of redundancy switching are improved. Fault diagnosis can be completed in milliseconds, enabling timely fault identification and ensuring task continuity and system stability.
[0038] The parameters of each temperature control unit are configured individually, enabling reliable switching of redundant loops and solving the shortcomings of previous test systems that suffered from poor system flexibility and high fault misjudgment rate due to single threshold values.
[0039] The proposed method of determining whether a temperature sensor is faulty based on its resistance value and temperature rise rate, and whether an electric heater is faulty based on its current value, can directly monitor the operating parameters of the thermal control components and participate in fault diagnosis. This replaces the previous method of indirectly determining the fault of the thermal control components by only collecting temperature values, thus improving the reliability of the thermal control process.
[0040] The proposed processor module is also configured to pre-set faults for one or more temperature sensors and electric heaters to simulate high-altitude engine thermal control component failures during the test. This fault injection function enables ground tests to verify the effectiveness of the redundant switching control method without altering the physical structure of the test subject. Attached Figure Description
[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0042] Figure 1 A schematic diagram of a test system for fault diagnosis of thermal control components of a high-altitude engine provided in an embodiment of this application; Figure 2 A schematic diagram showing the specific composition of a test system for fault diagnosis of thermal control components of a high-altitude engine, provided in an embodiment of this application; Figure 3 A schematic diagram illustrating the process of determining whether a temperature sensor is faulty, provided in an embodiment of this application; Figure 4 This is a flowchart illustrating the process for determining whether an electric heater is faulty, as provided in an embodiment of this application. Detailed Implementation
[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0044] like Figure 1 As shown in the embodiment of this application, a test system for fault diagnosis of thermal control components of high-altitude engines is provided, including: an analog quantity acquisition module, a processor module, a digital quantity output module, and several temperature control units, each temperature control unit including two temperature sensors and two electric heaters.
[0045] The analog signal acquisition module and the digital signal output module are both connected to the processor module. The temperature sensor and the electric heater are both connected to the analog signal acquisition module. The electric heater is also connected to the digital signal output module. Figure 1 Only the connection relationship between the analog signal acquisition module, the processor module, the digital signal output module and one temperature control unit is demonstrated; the connection relationship of other temperature control units is similar.
[0046] The analog signal acquisition module is configured to acquire the resistance signal of the temperature sensor and the current signal of the electric heater, convert them into digital signals of resistance and current, and then send them to the processor module.
[0047] The processor module is configured to: calculate the temperature value of the temperature sensor based on the resistance value, execute a temperature closed-loop control strategy according to the temperature value, and output a heating control signal to the digital output module.
[0048] The processor module is further configured to: perform a multivariate fusion fault diagnosis method based on the resistance value, the current value, and the temperature rise rate to obtain a fault diagnosis result; perform a redundancy switching control method based on the fault diagnosis result; and output a redundancy switching control signal to the digital output module.
[0049] The digital output module is configured to control the electric heater according to the heating control signal and the redundancy switching control signal.
[0050] Specifically, this embodiment includes 20 temperature control units. Each temperature control unit, together with the analog acquisition module, processor module, and digital output module, forms two measurement loops (corresponding to two temperature sensors) and two drive loops (corresponding to two electric heaters), for a total of 40 measurement loops and 40 drive loops. Figure 2The diagram shows the specific components of a test system for fault diagnosis of thermal control components of a high-altitude engine. Taking a temperature control unit of a certain temperature control part of the test product - engine in a space simulation environment as an example, the temperature control unit includes a temperature control sensor SenseA, a temperature measuring sensor SenseB, a main electric heater HeaterA, and a backup electric heater HeaterB.
[0051] Figure 2 In this circuit, the analog signal acquisition module connects to the temperature control sensor SenseA and the temperature measurement sensor SenseB via a measurement conditioning circuit and cables, forming two measurement loops. Within each temperature sensor's measurement loop, the measurement conditioning circuit uses a voltage divider method to measure the temperature, supporting real-time measurement of up to 40 signals with a measurement accuracy of 0.5%. The measurement conditioning circuit filters and amplifies the signals before the conditioned signals enter the analog signal acquisition module. The digital signal output module outputs TTL level control signals to control the drive switch, thus turning the electric heater on and off.
[0052] The analog signal acquisition module is connected to the main circuit heater (Heater A) and the backup circuit heater (Heater B) via Hall current sensors and cables. The digital signal output module is connected to the main circuit heater (Heater A) and the backup circuit heater (Heater B) via a power switch, a Hall current sensor, and a cable, forming two drive circuits. Each heater's drive circuit includes a power switch and a Hall current sensor. The power switch (BTS-5215L) is controlled by TTL level to switch the heater's power supply (28V) on and off. The Hall current sensor (ACS724) measures the operating current of each heater. The acquired current signal characterizes the heater's operating status and is then fed into the analog signal acquisition module.
[0053] Specifically, the formula for calculating the temperature value of the temperature sensor based on the resistance value is as follows: .
[0054] Among them, R T t represents the resistance of the thermistor at temperature T, in Ω; t represents the temperature in Celsius, in °C; a, b, and c are all settable coefficients.
[0055] Figure 2In this system, the analog signal acquisition module, processor module, and digital signal output module constitute the main control circuit. The main control circuit, measurement and conditioning circuit, power switch, and Hall current sensor constitute the measurement and control equipment. The main control program interface of the measurement and control equipment includes a parameter setting interface, a manual temperature control interface, an automatic temperature control interface, a fault injection interface, and a test history data interface. The parameter setting interface allows configuration of parameters for each measurement channel or drive channel; the automatic temperature control interface executes a closed-loop temperature control strategy; the manual temperature control interface allows manual control of the electric heater, real-time reading of temperature values and electric heater current values, and is used to confirm the functionality of each channel before the test; the fault injection interface simulates a fault in the thermal control components of the high-altitude engine during on-orbit operation, and manually sets a fault for a certain electric heater or temperature sensor when executing the temperature control strategy to verify the effectiveness of the redundant control method; the test history data interface allows designers to analyze the operating parameters of the engine's thermal control components after the test.
[0056] For example, in each temperature control unit, the two temperature sensors are referred to as the temperature control sensor and the temperature measurement sensor, respectively. The temperature control sensor and the temperature measurement sensor perform temperature measurement work simultaneously, which is a hot backup mode.
[0057] The two electric heaters are designated as the main electric heater and the backup electric heater. When heating is required, the main electric heater performs the heating operation. When the main electric heater fails, the backup electric heater takes over the heating operation, which is a cold backup mode.
[0058] Specifically, in this embodiment, each temperature control unit includes two identical temperature sensors and two identical electric heaters. One temperature sensor is the temperature control sensor SenseA, and the other is the temperature measurement sensor SenseB. The test system provides redundant measurement circuits for each temperature control unit, and temperature measurement is performed simultaneously during the test, which is a hot backup mode. One electric heater is the main circuit electric heater HeaterA, and the other is the backup circuit electric heater HeaterB. The test system provides redundant drive circuits for each temperature control unit. When heating is required, only one circuit of the main and backup circuits is working. When the main circuit electric heater fails, the backup circuit electric heater takes over the operation, which is a cold backup mode.
[0059] For example, the execution of the temperature closed-loop control strategy based on the temperature value includes: The temperature value corresponding to the temperature control sensor is compared with the preset upper and lower limits of the target temperature.
[0060] When the temperature value corresponding to the temperature control sensor is lower than the lower limit of the target temperature, the heating control signal controls the main electric heater to start heating.
[0061] When the temperature value corresponding to the temperature control sensor is higher than the upper limit of the target temperature, the heating control signal controls the main electric heater to stop heating.
[0062] When the temperature value corresponding to the temperature control sensor is within the range of the upper and lower limits of the target temperature, it is determined that the main electric heater is in normal working condition.
[0063] Specifically, in this embodiment, taking a temperature control unit as an example, during the test, the temperature control sensor and the temperature measuring sensor simultaneously measure the temperature. The measurement and control equipment uses the temperature value TA fed back by the temperature control sensor SenseA as the control feedback variable to perform closed-loop control on the main electric heater HeaterA. The temperature TB of the temperature measuring sensor SenseB is collected. TB does not participate in the temperature closed-loop control. If the main electric heater is fault-free, the backup electric heater will not work. The measurement and control equipment can set a temperature target range T1 to T2 for each temperature control unit. The measurement and control equipment compares the collected temperature TA with the upper and lower limits of the target temperature for each temperature control unit. When TA is lower than the lower limit T1, the digital output module outputs a high level, and the main electric heater starts to work. When TA is higher than the upper limit T2, the digital output module outputs a low level, and the main electric heater stops working.
[0064] Electric heater and temperature sensor normal operating status: When the electric heater is working, if the collected drive current is between the upper and lower limits of the set operating current, the software determines that the electric heater is working normally.
[0065] With the temperature control sensor and temperature measuring sensor's characteristic parameters (resistance) within acceptable ranges, and the electric heater in heating operation, if the temperature rise of both the temperature control sensor and temperature measuring sensor is greater than or equal to the preset temperature rise ΔTem in each monitoring cycle T, the software determines that the temperature control sensor and temperature measuring sensor are working normally. Where: ΔTem = current temperature Tem - initial heating temperature Tem0 of the electric heater, and the temperature rise measurement cycle is T.
[0066] For example, the parameters of each temperature control unit are configured individually, including: target temperature upper and lower limit parameters, temperature sensor fault diagnosis parameters, and electric heater fault diagnosis parameters.
[0067] Specifically, in this embodiment, before the formal test, the test system can configure parameters for each temperature control unit individually: set the upper and lower limits of temperature for each temperature control unit individually (target temperature upper and lower limit parameters); set the upper and lower limits of current for the electric heater individually (electric heater fault diagnosis parameters); and set the threshold ΔTem individually (temperature sensor fault diagnosis parameters).
[0068] For example, the multivariate fusion fault diagnosis method includes: The temperature sensor is determined to be faulty based on the resistance value and the rate of temperature rise.
[0069] The electric heater is determined to be faulty based on the current value.
[0070] For example, determining whether the temperature sensor is faulty based on the resistance value and the temperature rise rate includes: The resistance value is compared with the preset upper and lower resistance limits. If the resistance value is not within the range of the upper and lower resistance limits, the corresponding temperature sensor is determined to be faulty.
[0071] The temperature rise rate is defined as the amount of temperature rise within the monitoring period.
[0072] When the resistance value is within the upper and lower limits of the resistance, the temperature rise is compared with the preset temperature rise. If the temperature rise of both temperature sensors is greater than the preset temperature rise, it is determined that both temperature sensors are normal. If the temperature rise of both temperature sensors is less than the preset temperature rise, it indicates that the electric heater power is insufficient. If the temperature rise of the two temperature sensors is greater than and less than the preset temperature rise respectively, it is determined that the temperature sensor corresponding to the temperature rise less than the preset temperature rise is faulty.
[0073] Specifically, such as Figure 3 The diagram shows a flowchart for determining whether a temperature sensor is faulty.
[0074] Abnormal temperature sensor characteristics: If the temperature sensor's resistance exceeds the set upper limit R1, the measurement circuit is considered open-circuit faulted; if the resistance is below the set lower limit R2, the measurement circuit is considered short-circuit faulted. Mode selection basis: The maximum ambient temperature range of the temperature sensor is approximately -40 to 150℃. To improve the robustness of software recognition, a wider range (-50 to 200℃) is selected as the boundary value for judgment. If the measured temperature sensor resistance is less than 400Ω (corresponding to a temperature of approximately 200℃), the temperature sensor is considered short-circuited; if the resistance is greater than 1000kΩ (corresponding to a temperature of approximately -50℃), the temperature sensor is considered open-circuited.
[0075] Under the condition that the temperature sensor's own characteristic parameters are normal and the electric heater is continuously operating, if one of the temperature control sensor and the temperature measuring sensor is greater than or equal to the preset temperature rise ΔTem, while the other is less than the preset temperature rise ΔTem within the monitoring period T, then the sensor with the smaller temperature rise is determined to be faulty. If both are less than the preset temperature rise ΔTem, it will indicate that the electric heater's heating power is insufficient.
[0076] For example, determining whether the electric heater is faulty based on the current value includes: The current value is compared with the preset upper and lower current limits. If the current value is not within the range of the upper and lower current limits, the electric heater is determined to be faulty. If the current value is within the range of the upper and lower current limits, the electric heater is determined to be normal.
[0077] Specifically, such as Figure 4 The diagram shown illustrates the process for determining whether an electric heater is malfunctioning.
[0078] When the electric heater is working, if the driving current is greater than the preset upper limit value I1, the electric heater is determined to have a short circuit fault.
[0079] When the electric heater is working, if the driving current is less than the preset lower current limit value I2, the electric heater is determined to be open circuit fault.
[0080] For example, the redundancy switching control method includes: Condition a: If the main circuit electric heater and temperature control sensor are normal, but the temperature sensor is faulty, maintain the existing control strategy and determine that the temperature sensor is faulty.
[0081] Condition b: If the main electric heater and temperature sensor are normal, but the temperature control sensor is faulty, switch the temperature sensor to a new temperature control sensor and determine that the original temperature control sensor is faulty.
[0082] Condition c: If the temperature control sensor and temperature measurement sensor are normal, but the main circuit electric heater is faulty, switch the backup circuit electric heater to the new main circuit electric heater, and determine that the original main circuit electric heater is faulty.
[0083] Under condition d, if either the temperature control sensor or the temperature measurement sensor fails, or the main electric heater fails, the backup electric heater will be switched to the new main electric heater, and the original main electric heater will be determined to be faulty. Then, redundancy switching control will continue according to condition a or condition b.
[0084] Condition e: If both the temperature control sensor and the temperature measurement sensor are faulty, stop powering the electric heater.
[0085] Condition f: If both the main circuit electric heater and the backup circuit electric heater fail, stop supplying power to the electric heaters.
[0086] Specifically, through the redundancy switching control method, if the test system detects a failure in the thermal control component, it can automatically switch to another channel to work, thus solving the problem of unexpected test termination caused by the failure of a component of the engine thermal control component during ground testing.
[0087] For example, the processor module is also configured to pre-set faults for one or more temperature sensors and electric heaters to simulate faults in the thermal control components of a high-altitude engine during the test.
[0088] This application also provides a method for using the above-mentioned test system for fault diagnosis of high-altitude engine thermal control components, including the following steps: Step 1: Collect the resistance signal from the temperature sensor and the current signal from the electric heater, and convert them into digital resistance and current signals.
[0089] Step 2: Calculate the temperature value of the temperature sensor based on the resistance value, execute the temperature closed-loop control strategy according to the temperature value, and output the heating control signal.
[0090] Step 3: Based on the resistance value and the current value, and combined with the temperature rise rate, execute the multivariate fusion fault diagnosis method to obtain the fault diagnosis result. Then, execute the redundancy switching control method according to the fault diagnosis result and output the redundancy switching control signal.
[0091] Step four: Control the electric heater according to the heating control signal and the redundancy switching control signal.
[0092] This application's embodiments improve the timeliness of fault diagnosis and the reliability of redundancy switching by using multivariate fusion fault diagnosis based on resistance value, current value, and temperature rise rate. Fault diagnosis can be completed in milliseconds, enabling timely fault identification and ensuring task continuity and system stability.
[0093] The parameters of each temperature control unit are configured individually, enabling reliable switching of redundant loops and solving the shortcomings of previous test systems that suffered from poor system flexibility and high fault misjudgment rate due to single threshold values.
[0094] The proposed method of determining whether a temperature sensor is faulty based on its resistance value and temperature rise rate, and whether an electric heater is faulty based on its current value, can directly monitor the operating parameters of the thermal control components and participate in fault diagnosis. This replaces the previous method of indirectly determining the fault of the thermal control components by only collecting temperature values, thus improving the reliability of the thermal control process.
[0095] The proposed processor module is also configured to pre-set faults for one or more temperature sensors and electric heaters to simulate high-altitude engine thermal control component failures during the test. This fault injection function enables ground tests to verify the effectiveness of the redundant switching control method without altering the physical structure of the test subject.
[0096] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0097] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A test system for fault diagnosis of thermal control components of high-altitude engines, characterized in that, include: The system includes an analog signal acquisition module, a processor module, a digital signal output module, and several temperature control units. Each temperature control unit includes two temperature sensors and two electric heaters. The analog signal acquisition module and the digital signal output module are both connected to the processor module. The temperature sensor and the electric heater are both connected to the analog signal acquisition module. The electric heater is also connected to the digital signal output module. The analog signal acquisition module is configured to acquire the resistance signal of the temperature sensor and the current signal of the electric heater, convert them into digital signals of resistance and current, and then send them to the processor module. The processor module is configured to: calculate the temperature value of the temperature sensor based on the resistance value, execute a temperature closed-loop control strategy according to the temperature value, and output a heating control signal to the digital output module. The processor module is also configured to: perform a multivariate fusion fault diagnosis method based on the resistance value, the current value, and the temperature rise rate to obtain a fault diagnosis result; perform a redundancy switching control method according to the fault diagnosis result; and output a redundancy switching control signal to the digital output module. The digital output module is configured to control the electric heater according to the heating control signal and the redundancy switching control signal.
2. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 1, characterized in that, In each temperature control unit, two temperature sensors are designated as the temperature control sensor and the temperature measurement sensor, respectively. The temperature control sensor and the temperature measurement sensor perform temperature measurement work simultaneously, which is a hot backup mode. The two electric heaters are designated as the main electric heater and the backup electric heater. When heating is required, the main electric heater performs the heating operation. When the main electric heater fails, the backup electric heater takes over the heating operation, which is a cold backup mode.
3. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 2, characterized in that, The temperature closed-loop control strategy based on the temperature value includes: The temperature value corresponding to the temperature control sensor is compared with the preset upper and lower limits of the target temperature. When the temperature value corresponding to the temperature control sensor is lower than the lower limit of the target temperature, the heating control signal controls the main electric heater to start heating. When the temperature value corresponding to the temperature control sensor is higher than the target temperature limit, the heating control signal controls the main electric heater to stop heating. When the temperature value corresponding to the temperature control sensor is within the range of the upper and lower limits of the target temperature, it is determined that the main electric heater is in normal working condition.
4. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 1, characterized in that, Each temperature control unit has its own set of parameters, including: target temperature upper and lower limits, temperature sensor fault diagnosis parameters, and electric heater fault diagnosis parameters.
5. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 2, characterized in that, The multivariate fusion fault diagnosis method includes: Determine whether the temperature sensor is faulty based on the resistance value and the temperature rise rate. The electric heater is determined to be faulty based on the current value.
6. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 5, characterized in that, Determining whether the temperature sensor is faulty based on the resistance value and the temperature rise rate includes: The resistance value is compared with the preset upper and lower limits of resistance. When the resistance value is not within the range of the upper and lower limits of resistance, the corresponding temperature sensor is determined to be faulty. The temperature rise rate is defined as the amount of temperature rise within the monitoring period; When the resistance value is within the upper and lower limits of the resistance, the temperature rise is compared with the preset temperature rise. If the temperature rise of both temperature sensors is greater than the preset temperature rise, it is determined that both temperature sensors are normal. If the temperature rise of both temperature sensors is less than the preset temperature rise, it indicates that the electric heater power is insufficient. If the temperature rise of the two temperature sensors is greater than and less than the preset temperature rise respectively, it is determined that the temperature sensor corresponding to the temperature rise less than the preset temperature rise is faulty.
7. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 5, characterized in that, Determining whether the electric heater is faulty based on the current value includes: The current value is compared with the preset upper and lower current limits. If the current value is not within the range of the upper and lower current limits, the electric heater is determined to be faulty. If the current value is within the range of the upper and lower current limits, the electric heater is determined to be normal.
8. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 2, characterized in that, The redundancy switching control method includes: Condition a: If the main electric heater and temperature control sensor are normal, but the temperature sensor is faulty, maintain the existing control strategy and determine that the temperature sensor is faulty. Condition b: If the main electric heater and temperature sensor are normal, but the temperature control sensor is faulty, switch the temperature sensor to a new temperature control sensor and determine that the original temperature control sensor is faulty. Condition c: If the temperature control sensor and temperature measurement sensor are normal, but the main circuit electric heater is faulty, switch the backup circuit electric heater to the new main circuit electric heater, and determine that the original main circuit electric heater is faulty. Condition d: If either the temperature control sensor or the temperature measurement sensor fails, or the main electric heater fails, the backup electric heater will be switched to the new main electric heater, and the original main electric heater will be determined to be faulty. Then, the redundancy switching control will continue according to condition a or condition b. Condition e: If both the temperature control sensor and the temperature measurement sensor are faulty, stop powering the electric heater. Condition f: If both the main circuit electric heater and the backup circuit electric heater fail, stop supplying power to the electric heaters.
9. The test system for fault diagnosis of thermal control components of high-altitude engines according to claim 1, characterized in that, The processor module is also configured to pre-set faults for one or more temperature sensors and electric heaters to simulate faults in the thermal control components of a high-altitude engine during the test.
10. The method of using the test system for fault diagnosis of thermal control components of high-altitude engines as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Step 1: Collect the resistance signal from the temperature sensor and the current signal from the electric heater, and convert them into digital signals of resistance and current values. Step 2: Calculate the temperature value of the temperature sensor based on the resistance value, execute the temperature closed-loop control strategy according to the temperature value, and output the heating control signal; Step 3: Based on the resistance value and the current value, and combined with the temperature rise rate, execute the multivariate fusion fault diagnosis method to obtain the fault diagnosis result. Then, execute the redundancy switching control method according to the fault diagnosis result and output the redundancy switching control signal. Step four: Control the electric heater according to the heating control signal and the redundancy switching control signal.