Engine airflow temperature measurement dynamic compensation method and system

Abstract

The invention relates to an engine airflow temperature measurement dynamic compensation method and a measurement system. The engine temperature measurement system comprises a temperature acquisition module which is used for acquiring multi-path airflow temperature at an inlet and an outlet of an engine and converting the multi-path airflow temperature into voltage data to obtain temperature detection data; the temperature measuring system is used for selecting one of a plurality of preset temperature dynamic compensation methods for loading, compensating the temperature detection data by using the loaded temperature dynamic compensation method, and further selecting a replacement method according to a temperature data comparison result before and after temperature compensation, performing iterative optimization on the current method, or storing a temperature compensation result; the temperature dynamic compensation method comprises a temperature dynamic compensation method based on an improved grey wolf algorithm, and the algorithm generates new grey wolf individuals by introducing a variation strategy based on target function value ranking. According to the invention, the real-time and accurate dynamic compensation of the engine temperature measurement data can be realized with low deployment cost and computing power demand.

Description

Technical Field

[0001] The present invention relates to the technical field of engine temperature measurement, and in particular to a method and system for dynamic compensation of airflow temperature measurement. Background Art

[0002] In aircraft engine operation and maintenance, airflow temperature is a key parameter for measuring engine performance and health. This study addresses the issues of slow dynamic response and large dynamic errors in airflow temperature sensors used in the control and health management of current and under-development fourth-generation aircraft engines. In airflow temperature measurement, due to the inability of airflow kinetic energy to fully recover thermal energy and the presence of heat exchange with the surrounding environment, the sensor's measured temperature deviates from the airflow temperature, resulting in velocity error and heat transfer error. Furthermore, temperature sensors primarily use contact-type temperature sensors. Due to the inherent thermal inertia of thermocouples and RTD sensors, the sensor's measured temperature changes not only lag behind airflow temperature changes but also deviate from the airflow temperature in value. This results in dynamic errors in actual engineering measurements. The sensor's inherent heat capacity, structural dimensions, and operating conditions such as the flow velocity, turbulence, temperature, and pressure of the measured medium all affect the sensor's dynamic characteristics, leading to problems such as slow dynamic response and large dynamic errors. The dynamic characteristics of the temperature sensor are affected by the coupling interference of multiple factors under complex working conditions, making it difficult to determine the dynamic characteristics of the airflow temperature sensor, which brings difficulties to the research on the dynamic compensation method of the sensor. The measurement results caused by multiple errors make it difficult to accurately obtain the airflow temperature error law, making it difficult to obtain accurate measurement results through compensation methods. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method and system for dynamic compensation of engine airflow temperature. The present invention can realize real-time and accurate dynamic compensation of engine inlet and outlet airflow temperature measurement data with lower deployment cost and computing power requirement.

[0004] The technical solution adopted by the present invention to solve the technical problem is to provide a dynamic compensation method for engine airflow temperature measurement, comprising:

[0005] Collect the temperatures of multiple airflows at the engine inlet and outlet at different times and convert them into voltage data to obtain temperature detection data;

[0006] The temperature detection data is used as the input signal of the temperature dynamic compensation system, and a transfer function is constructed based on a differential equation of the input signal and the output signal of the temperature dynamic compensation system;

[0007] Taking the transfer function as a gray wolf individual and the least square mean square error as the target, the improved gray wolf optimization algorithm is used to solve the optimal parameters of the transfer function, thereby obtaining the optimal transfer function;

[0008] The optimal transfer function is used to dynamically compensate the temperature detection data in real time.

[0009] Furthermore, the improved gray wolf optimization algorithm includes:

[0010] Randomly initialize multiple gray wolf individuals in the gray wolf population;

[0011] Calculate the objective function value of each gray wolf individual in the population, and select the three best gray wolf individuals based on the objective function value;

[0012] Use the location information of the three best gray wolf individuals to update the location information of other gray wolf individuals in the population;

[0013] If the maximum number of iterations is reached, the optimal gray wolf individual is output; otherwise, the process returns to the step of calculating the objective function value of each gray wolf individual in the population.

[0014] The present invention also provides an engine airflow temperature measurement system, comprising:

[0015] The temperature acquisition module is used to collect the temperatures of multiple airflows at the engine inlet and outlet at different times and convert them into voltage data to obtain temperature detection data;

[0016] A temperature measurement system is used to load one of a plurality of preset temperature dynamic compensation methods, and use the loaded temperature dynamic compensation method to temperature compensate the temperature detection data, and then compare the temperature data before and after temperature compensation and select, based on the comparison result, to change the temperature dynamic compensation method, iteratively optimize the current temperature dynamic compensation method, or save the temperature compensation result; the temperature dynamic compensation method includes any of the temperature measurement dynamic compensation methods described above.

[0017] Furthermore, the temperature acquisition module includes a first temperature acquisition module arranged at the engine inlet and a second temperature acquisition module arranged at the engine outlet.

[0018] Furthermore, the first temperature acquisition module includes:

[0019] Multi-channel thermal resistance sensor, used for multi-channel parallel acquisition of airflow temperature at the engine inlet;

[0020] A multi-channel signal conditioner, each signal conditioner is connected in series with a corresponding thermal resistance sensor, and is used to condition the signal output by the thermal resistance sensor into a DC voltage signal;

[0021] The first multi-channel control collector is used to convert the voltage signals output by the signal conditioners into digital signals, and send the temperature detection data obtained by the conversion to the temperature measurement system.

[0022] Furthermore, the signal conditioner uses a bridge measurement method and a constant current source measurement method to condition the signal output by the thermal resistance sensor.

[0023] Furthermore, the second temperature acquisition module includes:

[0024] Multi-channel thermocouple sensor, used for multi-channel parallel acquisition of airflow temperature at the engine outlet;

[0025] The second multi-channel control collector is used to convert the voltage signals output by each thermocouple sensor into digital signals and send the converted temperature detection data to the temperature measurement system.

[0026] Furthermore, the first multi-channel control collector and the second multi-channel control collector both include an acquisition module, which is used to convert the voltage signal into a digital signal. The acquisition module implements full-bridge and half-bridge switching through an electronic switch, and the switched signal is directly connected to the input end of the analog-to-digital converter; the implementation of full-bridge and half-bridge switching through the electronic switch includes:

[0027] For 1 / 4 bridge switching, the 1 / 4 bridge 120R and 350R switching is achieved through relays;

[0028] For input mode switching, the DIF_DC and GND modes are switched through a photorelay;

[0029] For the bridge voltage part, electronic switches are used to achieve 2V, 5V, and 10V bridge voltage switching.

[0030] Furthermore, the temperature measurement system is loaded using a static link library or a dynamic link method to achieve simultaneous loading of multiple temperature dynamic compensation methods, and each temperature dynamic compensation method has a one-to-one correspondence with its parameters.

[0031] Beneficial effects

[0032] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: the present invention introduces a mutation strategy based on the ranking of objective function values into the Gray Wolf algorithm, utilizes the historical temperature real value data of the engine and the temperature sensor measurement value, constructs a transfer function between the temperature sensor measurement value and the real value under different working conditions, optimizes the transfer function parameters through the Gray Wolf algorithm, and then obtains the optimal transfer function under different working conditions, and implants the optimal function into the controller, and gives the temperature value after dynamic compensation in real time according to the temperature data collected by the sensor, which can reduce the dependence on parameter settings, quickly and accurately give the engine temperature dynamic compensation result with simple operation; according to the ranking of the individual objective function values of the Gray Wolf algorithm, The proportion of the gray wolf group in the overall fitness function value ranking, determining several preferred positions to generate new gray wolf individuals, can accelerate the convergence speed of the algorithm and improve the optimization performance of the algorithm, thereby obtaining better dynamic compensation results; the present invention ensures the comprehensiveness and accuracy of temperature data by arranging multiple temperature sensors at the engine inlet and outlet, and converting them into digital signals through an acquisition module and transmitting them to the temperature measurement system in real time. In addition, after the temperature measurement system synchronizes the data, it selects a dynamic compensation method and loads the method parameters to calculate the compensated temperature. According to the comparison results of the temperature values before and after compensation, it adaptively selects to iteratively optimize the current algorithm, switch to a new algorithm, or save the compensation results, thereby improving the accuracy and reliability of temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a flow chart of a first embodiment of the present invention;

[0034] Figure 2 is a schematic structural diagram of a second embodiment of the present invention;

[0035] Figure 3 is a structural diagram of a control acquisition module according to a second embodiment of the present invention;

[0036] Figure 4 is a flow chart of a temperature measurement system according to a second embodiment of the present invention;

[0037] Figure 5 is a flow chart of the dynamic compensation algorithm optimization iteration according to the second embodiment of the present invention;

[0038] Figure 6 Schematic diagram of a temperature compensation method based on an improved grey wolf algorithm according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0039] Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiments are only used to illustrate the present invention and are not used in limiting the scope of the present invention.In addition, should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall equally within the scope limited by the appended claims of the application.

[0040] The first embodiment of the present invention relates to a temperature measurement dynamic compensation method, such as Figure 1 Shown, including:

[0041] Collect the temperatures of multiple airflows at the engine inlet and outlet at different times and convert them into voltage data to obtain temperature detection data;

[0042] The temperature detection data is used as the input signal of the temperature dynamic compensation system, and a transfer function is constructed based on a differential equation of the input signal and the output signal of the temperature dynamic compensation system;

[0043] Taking the transfer function as a gray wolf individual and the least square mean square error as the target, the improved gray wolf optimization algorithm is used to solve the optimal parameters of the transfer function, thereby obtaining the optimal transfer function;

[0044] The optimal transfer function is used to dynamically compensate the temperature detection data in real time.

[0045] Among them, the improved gray wolf optimization algorithm includes the following steps:

[0046] Assume that the output value of the dynamic compensation system is U′, and the transient temperature signal Y measured by the temperature sensor is used as the input of the dynamic compensation system to construct the differential equation:

[0047]

[0048] Where a0, a1, ..., a n and b0, b1, …, b m is the working structure parameter of the sensor, n=m+1. The larger m is, the more accurate the solution is, but the more computing resources are consumed. Generally, m=5.

[0049] The numerator and denominator coefficients in the transfer function are obtained using the improved grey wolf optimization algorithm (IGWO), and the objective function uses the least square mean square error. The objective function can be expressed as

[0050]

[0051] Where U(n) is the true value of air flow temperature.

[0052] Step 1: Collect the dynamic temperature series of the airflow under different working conditions (working condition parameters include total airflow temperature, mass flow rate, total airflow pressure, step temperature, etc.) and the actual temperature value of the temperature sensor, clean the data, and remove outliers and noise;

[0053] Step 2: Randomly initialize individual gray wolves from a group of N gray wolves, i.e., N feasible transfer functions of the dynamic compensation system. A larger N number leads to a more accurate solution, but consumes more computing resources.

[0054]

[0055] Where Pos is a wolf pack consisting of N gray wolves, that is, N initialized transfer function parameter values, and the meanings of a and b are shown in formula (8).

[0056] Step 3: Substitute Pos into formula (8) to obtain N differential equations H(z), and then obtain the actual output values U′ of the N dynamic compensation systems. Use formula (9) to calculate the objective function value f of the N individual gray wolves in the population, sort the gray wolves from low to high according to the size of the f value, and select the top three gray wolf individuals in the gray wolf population, set as X α 、X β 、X δ .

[0057] Step 4: According to the following formula, we can divide X α 、X β 、X δ Each gray wolf 's information will be updated.

[0058]

[0059] Where, For the gray wolf distance distance; and is the swing factor; t is the current number of iterations; a is the value that decreases linearly from 2 to 0 during the iteration process; Maxiter is the preset maximum number of iterations; is a random variable in [0,1], whose length is same; is the individual gray wolf after one iterative update.

[0060] Step 5: After all the gray wolf individuals are iteratively updated once according to step 4, the objective function value of the gray wolf population is recalculated, and the gray wolf individuals with better values are selected.

[0061] Step six: The algorithm is judged to determine whether the maximum number of iterations has been reached or whether a certain gray wolf individual meets the error requirements. If the judgment conditions are met, the optimal gray wolf individual is output, that is, the transfer function of the optimal dynamic compensation system. At this time, the dynamic compensation system constructed according to the optimal transfer function can minimize the dynamic error during measurement.

[0062] The pseudo code for steps 1 to 6 is as follows:

[0063]

[0064] Finally, the optimized dynamic compensation method can be used to verify the feasibility of the compensation algorithm model through various methods such as setting up a simulation test bench in the laboratory and performing thermal wind tunnel temperature tests, and further optimize and iterate the compensation algorithm model until the requirements of the compensation algorithm are met.

[0065] The following further describes the application of this embodiment in an engine airflow temperature measurement system as an example.

[0066] The engine airflow temperature measurement system of this embodiment includes engine inlet temperature acquisition, engine outlet (turbine exhaust) temperature acquisition, dynamic compensation core processing module, and temperature measurement system.

[0067] Engine inlet temperature acquisition primarily collects airflow temperature signals from multiple RTDs. This system consists of multiple RTD sensors, their signal conditioners, and a multi-channel control and acquisition unit. The RTD temperature sensors are connected to the signal conditioners, which convert the RTD sensor analog resistance signals into DC voltage signals. These signals are then connected to the multi-channel control and acquisition unit via dedicated signal adapters. The control and acquisition module within the multi-channel control and acquisition unit converts the DC voltage analog signals into digital signals and transmits them via Ethernet to the temperature measurement system.

[0068] Engine outlet temperature acquisition primarily collects temperature signals from multiple thermocouple airflows. This system consists of multiple thermocouple sensors and a multi-channel control collector. The analog signals from the thermocouple sensors are connected to the multi-channel control collector via dedicated signal adapters. The internal acquisition circuitry in the multi-channel control collector converts the DC voltage analog signals into digital signals. The collected digital signals are analyzed and processed by the acquisition control module and then transmitted via Ethernet to the temperature measurement system.

[0069] The temperature measurement system includes a measurement system computer and measurement software; the temperature measurement software is installed in the computer, including control data acquisition, data reception and analysis, data synchronization and alignment, dynamic compensation core processing modules, information database, data display and storage, and user interface modules, to complete the control and data transmission with the two acquisition systems of engine inlet temperature acquisition and engine outlet temperature acquisition, and realize real-time output display and storage of dynamic compensation of temperature data; the information database realizes data management functions, with data addition, storage, modification, deletion, and query functions. The managed data types include but are not limited to original data, result data, and method parameter data, etc., and can output data and reports as needed for analysis applications.

[0070] The dynamic compensation core processing module is integrated into the temperature test system and serves as its core processing module. It includes multiple dynamic compensation methods, a method management module, and a parameter setting and management module. By studying the dynamic characteristics of airflow temperature sensors and compensation methods, dynamic compensation is performed after temperature data is collected and displayed in real-time for comparison.

[0071] The multi-channel control and acquisition unit consists of a power module, acquisition module, acquisition control module, time synchronization module, and Ethernet module. The acquisition and control unit utilizes an ARM+FPGA architecture, implementing Ethernet communication and acquisition channel control functions. This improves overall system reliability and communication speed, ensuring long-term stable and reliable operation and preventing system crashes caused by prolonged operation or complex logic processing. It enables real-time acquisition, data protocol conversion, data transmission, and logic control. The signal acquisition unit amplifies and filters the DC voltage signal conditioned by the signal conditioner before acquiring it using a 24-bit Σ-Δ A / D converter to ensure accurate acquisition. Power for the signal conditioner is provided by the power conversion unit of the multi-channel acquisition unit. To meet 2-wire / 3-wire input requirements, the signal conditioner utilizes both bridge and constant current source measurement methods. By directly providing current excitation to the RTD via the constant current source, the voltage drop across the RTD can be accurately measured, unaffected by the voltage divider effect of the lead wire resistance and completely eliminating the effect of the lead wire on the measured resistance. The DC power module (12-36V) powers the controller and data collector. The synchronization module achieves synchronization through NTP timing or GPS and a synchronization clock box. The data collection module uses an electronic switch to switch between full-bridge and half-bridge signals, and implements a self-test function. Relays are used to switch between 120R and 350R quarter-bridge signals. Optical relays are used to switch between DIF_DC and GND input modes. An electronic switch switches between 2V, 5V, and 10V bridge voltages. The signal is input directly to the A / D input without an amplifier.

[0072] For multi-channel independent data collection, the time synchronization module of the front-end temperature collection is the data timestamp. When the data enters the data analysis module, it is necessary to synchronize the data of different acquisition channels and use the data synchronization alignment method based on the timestamp to complete the data synchronization.

[0073] The dynamic compensation core processing module is placed within the temperature measurement software, and data exchange is carried out internally through the method interface. The dynamic compensation core processing module can load multiple different dynamic compensation methods, and the one-to-one correspondence between the methods and their parameters is achieved through the method management and parameter setting management modules. During the temperature measurement process, the effects of different methods can be compared and displayed through method selection. In the dynamic compensation method processing flow, when the results do not meet expectations, there are two ways to deal with it: one is to continue to optimize the iterative dynamic compensation method, and the other is to achieve the target by selecting another dynamic compensation method for measurement. The dynamic compensation method can be loaded using a static link library or a dynamic link method, and the functions of adding methods, deleting methods, and upgrading methods can be implemented at the same time.

[0074] A second embodiment of the present invention relates to an engine temperature measurement system, such as Figure 2 As shown, it includes engine inlet temperature acquisition, engine outlet (turbine exhaust) temperature acquisition, dynamic compensation core processing module, and temperature measurement system.

[0075] The engine inlet temperature acquisition system consists of eight PT100 thermal resistor sensors, their signal conditioners, and a multi-channel control and acquisition unit, enabling the collection of multiple airflow temperature signals. The thermal resistor temperature sensors are connected to the signal conditioners, which convert the analog resistance signals from the thermal resistor sensors into DC voltage signals. The conditioned signals are then connected to the multi-channel control and acquisition unit via dedicated signal adapters. The control and acquisition module in the multi-channel control and acquisition unit converts the DC voltage analog signals into digital signals, which are then transmitted to the temperature measurement system via Ethernet.

[0076] The engine outlet temperature acquisition system includes eight thermocouple sensors and a multi-channel control collector, enabling the collection of multiple thermocouple airflow temperature signals. The analog signals output by the thermocouple sensors are connected to the multi-channel control collector via dedicated signal adapters. The internal acquisition circuitry of the multi-channel control collector converts the DC voltage analog signals into digital signals. The collected digital signals are analyzed and processed by the acquisition control module and then transmitted via Ethernet to the temperature measurement system.

[0077] The temperature measurement system includes a measurement system computer and measurement software. The temperature measurement software, installed on the computer, includes core processing modules for controlling data acquisition, data reception and analysis, data synchronization and alignment, dynamic compensation, an information database, data display and storage, and a user interface. These modules control and transmit data to and from the engine inlet and outlet temperature acquisition systems, enabling real-time output, display, and storage of dynamic compensation temperature data. The information database implements data management functions, including the ability to add, save, modify, delete, and query data. The managed data types include, but are not limited to, raw data, result data, and method parameter data. Data and reports can be output as needed for analytical applications.

[0078] The dynamic compensation core processing module is integrated into the temperature test system and serves as its core processing module. It includes multiple dynamic compensation methods, a method management module, and a parameter setting and management module. By studying the dynamic characteristics of airflow temperature sensors and compensation methods, dynamic compensation is performed after temperature data is collected and displayed in real-time for comparison.

[0079] like Figure 3 As shown, the multi-channel control and acquisition system consists of a power module, acquisition module, acquisition control module, time synchronization module, and Ethernet module. The acquisition control unit utilizes an ARM+FPGA architecture to implement Ethernet communication and acquisition channel control functions, improving overall system reliability and communication speed, ensuring long-term stable and reliable operation and preventing system crashes caused by prolonged operation or complex logic processing. It enables real-time acquisition, data protocol conversion, data transmission, and logic control. The signal acquisition unit amplifies and filters the DC voltage signal conditioned by the signal conditioner before acquiring it using a 24-bit Σ-Δ A / D converter to ensure accurate acquisition. Power for the signal conditioner is provided by the power conversion unit of the multi-channel acquisition system. To meet 2-wire / 3-wire input requirements, the signal conditioner utilizes both bridge and constant current source measurement methods. By directly providing current excitation to the RTD, the constant current source accurately measures the voltage drop across the RTD, unaffected by the voltage divider caused by the lead resistance and completely eliminating the effect of the lead wire on the measured resistance. The DC power module (12-36V) powers the controller and data collector. The synchronization module achieves synchronization through NTP timing or GPS and a synchronization clock box. The data collection module uses an electronic switch to switch between full-bridge and half-bridge signals, and implements a self-test function. Relays are used to switch between 120R and 350R quarter-bridge signals. Optical relays are used to switch between DIF_DC and GND input modes. An electronic switch switches between 2V, 5V, and 10V bridge voltages. The signal is input directly to the A / D input without an amplifier.

[0080] In some implementations, the temperature measurement system software requires data synchronization and alignment. For 16 independent channels of data acquisition, after the acquisition system undergoes time synchronization, the data synchronization and alignment module finds the starting point of the multi-channel data at the same time based on the timestamp to complete the data synchronization and alignment.

[0081] More specifically, the power module supplies power to the controller and collector through POE or DC (12~36V); the time synchronization module synchronizes time through NTP or GPS and a synchronous clock box; the Ethernet module transmits the collected data to the temperature measurement system through Gigabit Ethernet; the acquisition control module adopts ARM+FPGA architecture, and the ARM processor is ARMCortex TM -M4 processor is used for DSP operation and channel parallel signal processing; FPGA module communicates via 8-channel RS485 bus, and control acquisition is transmitted to ARM via 16-bit data bus, realizing Ethernet communication and acquisition channel control functions, real-time acquisition, data protocol conversion, data transmission, logic control and other functions.

[0082] The process of temperature measurement system is as follows Figure 4 As shown in the figure, after the equipment is connected and the software is prepared, the temperature measurement software initiates the control data acquisition, the software waits to receive the data, and performs real-time analysis and data synchronization alignment; the software selects the dynamic compensation method and loads the method parameters at the same time, and the data after data synchronization alignment is input into the dynamic compensation method module to calculate the compensated temperature; the temperature values before and after compensation are compared in real time. If they do not meet expectations, there are two ways to do it: one is to change the dynamic compensation method and compare the effects of different methods; the other is to optimize the iterative method; when the results meet expectations, the process and result data are saved to the information database.

[0083] Information databases include but are not limited to SQL SERVER, mySQL, etc., which manage data results and can also output data and reports as needed for analytical applications.

[0084] The following combination Figure 5 、 Figure 6 A temperature dynamic compensation method for an improved grey wolf algorithm is described, the method comprising:

[0085] Step 1: Collect the dynamic temperature series of the airflow under different working conditions (working condition parameters include total airflow temperature, mass flow rate, total airflow pressure, step temperature, etc.) and the actual temperature value of the temperature sensor, clean the data, and remove outliers and noise;

[0086] Assume that the output value of the dynamic compensation system is U′, and the transient temperature signal Y measured by the temperature sensor is used as the input of the dynamic compensation system to construct the differential equation:

[0087]

[0088] Where a0, a1, ..., a n and b0, b1, …, b m is the working structure parameter of the sensor, n=m+1. The larger m is, the more accurate the solution is, but the more computing resources are consumed. Generally, m=5.

[0089] The numerator and denominator coefficients in the transfer function are obtained using the improved grey wolf optimization algorithm (IGWO), and the objective function uses the least square mean square error. The objective function can be expressed as

[0090]

[0091] Where U(n) is the true value of air flow temperature.

[0092] Step 2: Randomly initialize individual gray wolves from a group of N gray wolves, i.e., N feasible transfer functions of the dynamic compensation system. A larger N number leads to a more accurate solution, but consumes more computing resources.

[0093]

[0094] Where Pos is a wolf pack consisting of N gray wolves, that is, N initialized transfer function parameter values, and the meanings of a and b are shown in formula (15).

[0095] Step 3: Substitute Pos into formula (15) to obtain N differential equations H(z), and then obtain the actual output values U′ of the N dynamic compensation systems. Use formula (16) to calculate the objective function value f of the N individual gray wolves in the population, sort the gray wolves from low to high according to the size of the f value, and select the top three gray wolf individuals in the gray wolf population, set as X α 、X β 、X δ .

[0096] Step 4: According to the following formula, we can divide X α 、X β 、X δ Each gray wolf 's information will be updated.

[0097]

[0098] Where, For the gray wolf distance distance; and is the swing factor; t is the current number of iterations; a is the value that decreases linearly from 2 to 0 during the iteration process; Maxiter is the preset maximum number of iterations; is a random variable in [0,1], whose length is same; is the individual gray wolf after one iterative update.

[0099] Step 5: After all the gray wolf individuals are iteratively updated once according to step 4, the objective function value of the gray wolf population is recalculated, and the gray wolf individuals with better values are selected.

[0100] Step six: The algorithm is judged to determine whether the maximum number of iterations has been reached or whether a certain gray wolf individual meets the error requirements. If the judgment conditions are met, the optimal gray wolf individual is output, that is, the transfer function of the optimal dynamic compensation system. At this time, the dynamic compensation system constructed according to the optimal transfer function can minimize the dynamic error during measurement.

[0101] The pseudo code for steps 1 to 6 is as follows:

[0102]

[0103]

[0104] Finally, the optimized dynamic compensation method can be used to verify the feasibility of the compensation algorithm model through various methods such as setting up a simulation test bench in the laboratory and performing thermal wind tunnel temperature tests, and further optimize and iterate the compensation algorithm model until the requirements of the compensation algorithm are met.

Claims

1. A dynamic compensation method for engine airflow temperature measurement, characterized in that: include: Collect the temperatures of multiple airflows at the engine inlet and outlet at different times and convert them into voltage data to obtain temperature detection data; The temperature detection data is used as the input signal of the temperature dynamic compensation system, and a transfer function is constructed based on a differential equation of the input signal and the output signal of the temperature dynamic compensation system; Taking the transfer function as a gray wolf individual and the least square mean square error as the target, the improved gray wolf optimization algorithm is used to solve the optimal parameters of the transfer function, thereby obtaining the optimal transfer function; The optimal transfer function is used to dynamically compensate the temperature detection data in real time.

2. The method according to claim 1, characterized in that The improved gray wolf optimization algorithm includes: Randomly initialize multiple gray wolf individuals in the gray wolf population; Calculate the objective function value of each gray wolf individual in the population, and select the three best gray wolf individuals based on the objective function value; Use the location information of the three best gray wolf individuals to update the location information of other gray wolf individuals in the population; If the maximum number of iterations is reached, the optimal gray wolf individual is output; otherwise, the process returns to the step of calculating the objective function value of each gray wolf individual in the population.

3. An engine airflow temperature measurement system, characterized in that: include: The temperature acquisition module is used to collect the temperatures of multiple airflows at the engine inlet and outlet at different times and convert them into voltage data to obtain temperature detection data; A temperature measurement system, configured to load one of a plurality of preset temperature dynamic compensation methods, and perform temperature compensation on the temperature detection data using the loaded temperature dynamic compensation method, and then compare the temperature data before and after temperature compensation and select, based on the comparison result, to replace the temperature dynamic compensation method, iteratively optimize the current temperature dynamic compensation method, or save the temperature compensation result; the temperature dynamic compensation method includes any one of the temperature measurement dynamic compensation methods described in claims 1-2.

4. The system according to claim 3, characterized in that The temperature collection module includes a first temperature collection module arranged at the engine inlet and a second temperature collection module arranged at the engine outlet.

5. The system according to claim 4, characterized in that The first temperature acquisition module includes: Multi-channel thermal resistance sensor, used for multi-channel parallel acquisition of airflow temperature at the engine inlet; A multi-channel signal conditioner, each signal conditioner is connected in series with a corresponding thermal resistance sensor, and is used to condition the signal output by the thermal resistance sensor into a DC voltage signal; The first multi-channel control collector is used to convert the voltage signals output by the signal conditioners into digital signals, and send the temperature detection data obtained by the conversion to the temperature measurement system.

6. The system according to claim 5, characterized in that The signal conditioner uses a bridge measurement method and a constant current source measurement method to condition the signal output by the thermal resistance sensor.

7. The system according to claim 5, characterized in that The second temperature acquisition module includes: Multi-channel thermocouple sensor, used for multi-channel parallel acquisition of airflow temperature at the engine outlet; The second multi-channel control collector is used to convert the voltage signals output by each thermocouple sensor into digital signals and send the converted temperature detection data to the temperature measurement system.

8. The system according to claim 7, characterized in that The first multi-channel control collector and the second multi-channel control collector both include an acquisition module, which is used to convert voltage signals into digital signals. The acquisition module implements full-bridge and half-bridge switching through electronic switches, and the switched signals are directly connected to the input end of the analog-to-digital converter; the implementation of full-bridge and half-bridge switching through electronic switches includes: For 1 / 4 bridge switching, the 1 / 4 bridge 120R and 350R switching is achieved through relays; For input mode switching, the DIF_DC and GND modes are switched through a photorelay; For the bridge voltage part, electronic switches are used to achieve 2V, 5V, and 10V bridge voltage switching.

9. The system according to claim 3, wherein: The temperature measurement system is loaded by using a static link library or a dynamic link method to achieve simultaneous loading of multiple temperature dynamic compensation methods, and each temperature dynamic compensation method has a one-to-one correspondence with its parameters.

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