Gas circuit fault diagnosis method and system in aero-engine starting process

Abstract

The invention relates to the technical field of aero-engines, and discloses an aero-engine starting process gas circuit fault diagnosis method and system, and the method comprises the steps: building an envelope line of an examination parameter through obtaining a mapping relation between the examination parameter and a conversion rotating speed in a historical starting process; judging the condition that the assessment parameter exceeds the envelope line under the conversion rotating speed in the test process so as to judge whether the engine starting test is normal starting or not; according to the gas circuit fault diagnosis method and system in the aero-engine starting process, automatic data processing can be achieved, the data processing time and the debugging frequency are reduced, and a basis is provided for adjusting the starter power in the rotating speed interval or optimizing the starting oil supply rule.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengines, and discloses a method and a system for diagnosing gas path faults during the starting process of an aeroengine. Background Art

[0002] The starting process is the primary stage of aircraft engine operation. Once the engine fails to start, if it cannot be detected and corrected in time, it is very likely to cause engine blades to burn or be damaged, causing irreparable losses. Common starting failures include low starter power, cold suspension, hot suspension, and overheating. In the past, debugging required the accumulation of previous experience to solve this problem. How to quickly locate the fault, find out the cause of the fault and the speed range of the fault is particularly important. Summary of the invention

[0003] The purpose of the present invention is to provide a method and system for diagnosing gas circuit faults during the starting process of an aircraft engine, which can realize automatic data processing, reduce data processing time and debugging times, and provide a basis for adjusting the starter power in the speed range or optimizing the starting fuel supply law.

[0004] In order to achieve the above technical effects, the technical solution adopted by the present invention is: A method for diagnosing gas path faults during the starting process of an aircraft engine, comprising: Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally; Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order, and construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least squares method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; Step 3: Substitute the converted speed value of each acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the acquisition window center point; Step 4: constructing an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; Step 5. Obtain the converted speed curve and assessment parameter curve during the engine starting test, repeat steps 2 to 3, obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test, and determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, determine that the engine starting test has a fault; if not, determine that the engine starting test is a normal start.

[0005] Furthermore, the assessment parameter curve includes an engine pressure ratio curve, a converted low-pressure turbine outlet temperature curve and an acceleration curve corresponding to the engine speed; when the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the second assessment parameter correction values ​​corresponding to the acceleration curve are all within the corresponding envelope range during the engine starting test, the engine starting test is judged to be a normal start, otherwise the engine starting test is judged to be a fault.

[0006] Furthermore, the least square method is used to obtain the functional relationship between the parameter value in each acquisition window of each assessment parameter curve and the converted speed data: ,in , ,in is the parameter correction value of each acquisition window corresponding to the assessment parameter curve, , is the number of test parameter values ​​in the corresponding sampling window, The value is 1, 2 or 3. When is expressed as engine pressure ratio data, When is expressed as the converted low-pressure turbine outlet temperature data, When is expressed as acceleration data, In each acquisition window of the corresponding assessment curve, parameter values, To convert the speed.

[0007] Furthermore, the method of constructing an envelope curve of engine test parameters changing with converted speed includes: use The rule eliminates wild points of the first assessment parameter correction value in each sampling window when the engine is started normally for multiple times; According to the data after outliers are eliminated, the mean value and standard deviation of the first assessment parameter correction value of each sampling window are analyzed and obtained; use Analyze and obtain each normal start of each sampling window Value, take each sampling window in The maximum value in a normal start The value is the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point. It is the first time in a normal start after the wild point is eliminated. The first assessment parameter correction value corresponding to the sampling window, After removing the wild points The first normal start The average value of the first assessment parameter correction value corresponding to the sampling windows is After removing the wild points The first normal start The standard deviation of the first assessment parameter correction value corresponding to the sampling window.

[0008] Furthermore, if the new normal test data is calculated and it is determined that the engine start test fails, Average To update, follow Standard Deviation Update, recalculate the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point, and update the assessment parameter envelope; , for During the first start The average value of the first assessment parameter correction value corresponding to the sampling windows is For the The first start The first assessment parameter correction value corresponding to the sampling window, For the The first start The first assessment parameter correction value corresponding to the sampling window.

[0009] In order to achieve the above technical effects, the present invention also provides a system for diagnosing gas path faults during the start-up process of an aircraft engine, which is used to implement the method for diagnosing gas path faults during the start-up process of an aircraft engine; the system comprises: A data acquisition module is used to obtain the assessment parameter curve and the converted speed curve when the engine is started normally; A function construction module, used to divide the assessment parameter curve into multiple data acquisition windows in chronological order, and to construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least square method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; A first analysis module is used to substitute the converted rotation speed value of each acquisition window center point into the functional relationship to obtain a first assessment parameter correction value corresponding to the acquisition window center point; An envelope curve building module, used to build an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; The discrimination module is used to analyze and obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test according to the converted speed curve and the assessment parameter curve during the engine starting test, and to judge whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, output the judgment result that the engine starting test fails; if not, output the judgment result that the engine starting test is a normal start.

[0010] Furthermore, the assessment parameter curve includes an engine pressure ratio curve, a converted low-pressure turbine outlet temperature curve and an acceleration curve corresponding to the engine speed; in the judgment module, when the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the second assessment parameter correction value corresponding to the acceleration curve during the engine starting test are all within the corresponding envelope range, the engine starting test is judged to be a normal start, otherwise it is judged that a fault occurs in the engine starting test.

[0011] Furthermore, in the function construction module, the least square method is used to obtain the functional relationship between the parameter value in each acquisition window of each assessment parameter curve and the converted speed data: ,in , ,in is the parameter correction value of each acquisition window corresponding to the assessment parameter curve, , is the number of test parameter values ​​in the corresponding sampling window, The value is 1, 2 or 3. When is expressed as engine pressure ratio data, When is expressed as the converted low-pressure turbine outlet temperature data, When is expressed as acceleration data, In each acquisition window of the corresponding assessment curve, parameter values, To convert the speed.

[0012] Furthermore, in the envelope construction module, the process of constructing the envelope of the engine test parameter changing with the converted speed includes: use The rule eliminates wild points of the first assessment parameter correction value in each sampling window when the engine is started normally for multiple times; According to the data after outliers are eliminated, the mean value and standard deviation of the first assessment parameter correction value of each sampling window are analyzed and obtained; use Analyze and obtain each normal start of each sampling window Value, take each sampling window in The maximum value in a normal start The value is the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point. It is the first time in a normal start after the wild point is eliminated. The first assessment parameter correction value corresponding to the sampling window, After removing the wild points The first normal start The average value of the first assessment parameter correction value corresponding to the sampling windows is After removing the wild points The first normal start The standard deviation of the first assessment parameter correction value corresponding to the sampling window.

[0013] Furthermore, in the envelope construction module, if the engine start test is judged to be faulty after the new normal test data is tested and calculated, Average To update, follow Standard Deviation Update, recalculate the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point, and update the assessment parameter envelope; , for During the first start The average value of the first assessment parameter correction value corresponding to the sampling windows is For the The first start The first assessment parameter correction value corresponding to the sampling window, For the The first start The first assessment parameter correction value corresponding to the sampling window.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention obtains the mapping relationship between the assessment parameters and the converted speed in the historical starting process, constructs the envelope of the assessment parameters, and judges whether the assessment parameters at the converted speed during the test exceed the envelope, so as to judge whether the engine starting test is a normal start; the method and system for diagnosing air path faults in the starting process of an aircraft engine of the present invention can realize automatic data processing, reduce data processing time and debugging times, and provide a basis for adjusting the starter power in the speed range or optimizing the starting fuel supply law. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The flowchart of the method for diagnosing gas path faults during the start-up process of an aircraft engine in Embodiment 1 or 2; Figure 2 This is a structural block diagram of the air path fault diagnosis system during the aircraft engine starting process in Example 1; Figure 3 It is the envelope diagram of the engine pressure ratio in Example 2; Among them, 1. Data acquisition module; 2. Function construction module; 3. First analysis module; 4. Envelope construction module; 5. Discrimination module. DETAILED DESCRIPTION

[0016] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0017] Example 1 See also Figure 1 and Figure 2 , a method for diagnosing gas path faults during the starting process of an aircraft engine, comprising: Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally; Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order, and construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least squares method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; Step 3: Substitute the converted speed value of each acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the acquisition window center point; Step 4: constructing an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; Step 5. Obtain the converted speed curve and assessment parameter curve during the engine starting test, repeat steps 2 to 3, obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test, and determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, determine that the engine starting test has a fault; if not, determine that the engine starting test is a normal start.

[0018] In this embodiment, by obtaining the mapping relationship between the assessment parameters and the converted speed during the historical starting process, the envelope of the assessment parameters is constructed, and the situation in which the assessment parameters at the converted speed during the test exceed the envelope is judged to determine whether the engine starting test is a normal start; this embodiment can realize automatic data processing, reduce data processing time and debugging times, and provide a basis for adjusting the starter power in the speed range or optimizing the starting fuel supply law.

[0019] In this embodiment, the assessment parameter curve includes an engine pressure ratio curve, a converted low-pressure turbine outlet temperature curve, and an acceleration curve corresponding to the engine speed; when the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve, and the second assessment parameter correction value corresponding to the acceleration curve are all within the corresponding envelope range during the engine starting test, the engine starting test is judged to be a normal start, otherwise the engine starting test is judged to be a fault.

[0020] Based on the same inventive concept, this embodiment also provides a gas path fault diagnosis system for an aircraft engine starting process, comprising: Data acquisition module 1, used to obtain the assessment parameter curve and the converted speed curve when the engine is started normally; Function construction module 2, used to divide the assessment parameter curve into multiple data acquisition windows in chronological order, and to construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least square method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; The first analysis module 3 is used to substitute the converted speed value of each acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the acquisition window center point; An envelope curve building module 4 is used to build an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; The judgment module 5 is used to analyze and obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test based on the converted speed curve and the assessment parameter curve during the engine starting test, and judge whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, output the judgment result that the engine starting test fails; if not, output the judgment result that the engine starting test is a normal start.

[0021] Example 2 See also Figure 1 This embodiment takes a certain type of aircraft engine starting test as an example to describe in detail the process of the method for diagnosing gas path faults during the aircraft engine starting process of the present invention. The specific processing flow is as follows: Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally; In this embodiment, the test parameter curve includes the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the acceleration curve corresponding to the engine speed. Time-varying data, low pressure turbine outlet temperature Data that changes with speed, engine compression ratio The data changes with the speed. Then, according to the similar principle, the above data is converted into data under standard atmospheric pressure: that is, the speed is converted Data changing over time, converted low-pressure turbine outlet temperature Follow Changing data, Follow The changing data can be used to obtain the acceleration curve of the acceleration corresponding to the speed changing with the converted speed.

[0022] Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order, and construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least squares method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; The test system collects data according to time and is affected by noise. In particular, the accuracy of the data collected at low speeds is often poor. In order to reduce the impact of poor low speed collection accuracy and the impact of measurement data noise, this embodiment selects 7% as the initial speed and uses the sliding average method to calculate the average value of each unit speed. Therefore, in the data of a normal start, when determining the initial conversion speed Then, the converted speed is converted to 、 、 、…、 、 The conversion speed interval, the interval width is , The assessment parameters of the interval are divided into an interval value, and find out 、 、 、…、 、 The interval value of the assessment parameter corresponding to the interval.

[0023] Then, the least squares method is used to All the assessment parameter interval values ​​and the corresponding converted speed values ​​are fitted to obtain the analysis function of the corresponding assessment parameter; in this embodiment, the least squares method is used to obtain the functional relationship between the parameter value in each acquisition window of each assessment parameter curve and the converted speed data: ,in , ,in is the parameter correction value of each acquisition window corresponding to the assessment parameter curve, , is the number of test parameter values ​​in the corresponding sampling window, The value is 1, 2 or 3. When is expressed as engine pressure ratio data, When is expressed as the converted low-pressure turbine outlet temperature data, When is expressed as acceleration data, In each acquisition window of the corresponding assessment curve, parameter values, To convert the speed.

[0024] Step 3: Substitute the converted speed value of each acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the acquisition window center point; Step 4: constructing an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; In this embodiment, the method for constructing the envelope curve of the engine test parameter changing with the converted speed includes: 4.1 Adoption The rule eliminates wild points of the first assessment parameter correction value in each sampling window when the engine is started normally for multiple times; 4.2 Based on the data after outliers are removed, the mean value and standard deviation of the first assessment parameter correction value of each sampling window are analyzed and obtained; 4.3 Utilization Analyze and obtain each normal start of each sampling window Value, take each sampling window in The maximum value in a normal start The value is the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point. It is the first time in a normal start after the wild point is eliminated. The first assessment parameter correction value corresponding to the sampling window, After removing the wild points The first normal start The average value of the first assessment parameter correction value corresponding to the sampling windows is After removing the wild points The first normal start The standard deviation of the first assessment parameter correction value corresponding to the sampling window. The obtained engine pressure ratio envelope is as follows: Figure 3 As shown, represents the upper envelope, The envelopes of other assessment parameters are similar and will not be described here.

[0025] In this embodiment, according to the Chebyshev inequality, it can be obtained that the first engine pressure ratio acquisition window in a certain start satisfies , which indicates The probability of taking the average value of the first pressure ratio correction value of the first engine pressure ratio acquisition window in the first start The interval is ,in is the bandwidth coefficient of the engine envelope in the first engine pressure ratio acquisition window during this start, is the first pressure ratio correction value of the first engine pressure ratio acquisition window in this start-up. for The average value of the first pressure ratio correction value of the first engine pressure ratio acquisition window in the first start, for The standard deviation of the first pressure ratio correction value of the first engine pressure ratio acquisition window in the first start.

[0026] Step 5. Obtain the converted speed curve and assessment parameter curve during the engine starting test, repeat steps 2 to 3, obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test, and determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, determine that the engine starting test has a fault; if not, determine that the engine starting test is a normal start.

[0027] In this embodiment, when the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the second assessment parameter correction value corresponding to the acceleration curve during the engine starting test are all within the corresponding envelope range, the engine starting test is judged to be a normal start, otherwise it is judged that a fault occurs in the engine starting test.

[0028] Step 6: If the engine start test is judged to be faulty after the new normal test data is tested and calculated, follow Average To update, follow Standard Deviation Update, recalculate the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point, and update the assessment parameter envelope; , for During the first start The average value of the first assessment parameter correction value corresponding to the sampling windows is For the The first start The first assessment parameter correction value corresponding to the sampling window, For the The first start The first assessment parameter correction value corresponding to the sampling window.

[0029] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for diagnosing gas path faults during the start-up process of an aircraft engine, characterized in that: include: Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally; Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order, and construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least squares method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; Step 3: Substitute the converted speed value of each acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the acquisition window center point; Step 4: constructing an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; Step 5. Obtain the converted speed curve and assessment parameter curve during the engine starting test, repeat steps 2 to 3, obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test, and determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, determine that the engine starting test has a fault; if not, determine that the engine starting test is a normal start.

2. The method for diagnosing gas path faults during the start-up process of an aircraft engine according to claim 1, characterized in that: The assessment parameter curve includes an engine pressure ratio curve, a converted low-pressure turbine outlet temperature curve and an acceleration curve corresponding to the engine speed; when the second assessment parameter correction values ​​corresponding to the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the acceleration curve are all within the corresponding envelope range during the engine starting test, the engine starting test is judged to be a normal start, otherwise it is judged that a fault occurs in the engine starting test.

3. The method for diagnosing gas path faults during the start-up process of an aircraft engine according to claim 2, characterized in that: The functional relationship between the parameter value in each acquisition window of each assessment parameter curve and the converted speed data is obtained by using the least squares method: ,in , ,in is the parameter correction value of each acquisition window corresponding to the assessment parameter curve, , is the number of test parameter values ​​in the corresponding sampling window, The value is 1, 2 or 3. When is expressed as engine pressure ratio data, When is expressed as the converted low-pressure turbine outlet temperature data, When is expressed as acceleration data, In each acquisition window of the corresponding assessment curve parameter values, To convert the speed.

4. The method for diagnosing gas path faults during the start-up process of an aircraft engine according to claim 1, characterized in that: The method of constructing the envelope curve of engine test parameters changing with the converted speed includes: use The rule eliminates wild points of the first assessment parameter correction value in each sampling window when the engine is started normally for multiple times; According to the data after outliers are eliminated, the mean value and standard deviation of the first assessment parameter correction value of each sampling window are analyzed and obtained; use Analyze and obtain each normal start of each sampling window Value, take each sampling window in The maximum value in a normal start The value is the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point. It is the first time in a normal start after the wild point is eliminated. The first assessment parameter correction value corresponding to the sampling window, After removing the wild points The first normal start The average value of the first assessment parameter correction value corresponding to the sampling windows is After removing the wild points The first normal start The standard deviation of the first assessment parameter correction value corresponding to the sampling window.

5. The method for diagnosing gas path faults during the start-up process of an aircraft engine according to claim 4, characterized in that: If the new normal test data is calculated and it is determined that the engine start test has a fault, then follow Average To update, follow Standard Deviation Update, recalculate the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point, and update the assessment parameter envelope; , for During the first start The average value of the first assessment parameter correction value corresponding to the sampling windows is For the The first start The first assessment parameter correction value corresponding to the sampling window, For the The first start The first assessment parameter correction value corresponding to the sampling window.

6. A system for diagnosing gas path faults during the starting process of an aircraft engine, used to implement the method for diagnosing gas path faults during the starting process of an aircraft engine according to claim 1; characterized in that: include: A data acquisition module is used to obtain the assessment parameter curve and the converted speed curve when the engine is started normally; A function construction module, used to divide the assessment parameter curve into multiple data acquisition windows in chronological order, and to construct a functional relationship between the assessment parameter and the converted speed data in each acquisition window using the least square method according to the assessment parameter data value in each acquisition window and the converted speed data value corresponding to the assessment parameter data value; A first analysis module is used to substitute the converted rotation speed value of each acquisition window center point into the functional relationship to obtain a first assessment parameter correction value corresponding to the acquisition window center point; An envelope curve building module, used to build an envelope curve of the engine test parameter changing with the converted speed according to the first test parameter correction value when the engine is started normally for multiple times; The discrimination module is used to analyze and obtain the second assessment parameter correction value of the center point of each acquisition window during the engine starting test according to the converted speed curve and the assessment parameter curve during the engine starting test, and to judge whether the second assessment parameter correction value exceeds the envelope range in step 4. If so, output the judgment result that the engine starting test fails; if not, output the judgment result that the engine starting test is a normal start.

7. The air path fault diagnosis system for the aircraft engine starting process according to claim 6, characterized in that: The assessment parameter curve includes an engine pressure ratio curve, a converted low-pressure turbine outlet temperature curve and an acceleration curve corresponding to the engine speed; in the judgment module, when the second assessment parameter correction values ​​corresponding to the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve and the acceleration curve during the engine starting test are all within the corresponding envelope range, the engine starting test is judged to be a normal start, otherwise it is judged that a fault occurs in the engine starting test.

8. The air path fault diagnosis system for the aircraft engine starting process according to claim 7, characterized in that: In the function construction module, the functional relationship between the parameter value in each acquisition window of each assessment parameter curve and the converted speed data is obtained by using the least squares method: ,in , ,in is the parameter correction value of each acquisition window corresponding to the assessment parameter curve, , is the number of test parameter values ​​in the corresponding sampling window, The value is 1, 2 or 3. When is expressed as engine pressure ratio data, When is expressed as the converted low-pressure turbine outlet temperature data, When is expressed as acceleration data, In each acquisition window of the corresponding assessment curve parameter values, To convert the speed.

9. The air path fault diagnosis system for the aircraft engine starting process according to claim 8, characterized in that: In the envelope construction module, the process of constructing the envelope of the engine test parameters changing with the converted speed includes: use The rule eliminates wild points of the first assessment parameter correction value in each sampling window when the engine is started normally for multiple times; According to the data after outliers are eliminated, the mean value and standard deviation of the first assessment parameter correction value of each sampling window are analyzed and obtained; use Analyze and obtain each normal start of each sampling window Value, take each sampling window in The maximum value in a normal start The value is the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point. It is the first time in a normal start after the wild point is eliminated. The first assessment parameter correction value corresponding to the sampling window, After removing the wild points The first normal start The average value of the first assessment parameter correction value corresponding to the sampling windows is After removing the wild points The first normal start The standard deviation of the first assessment parameter correction value corresponding to the sampling window.

10. The air path fault diagnosis system for the aircraft engine starting process according to claim 9, characterized in that: In the envelope construction module, if the engine start test is judged to have a fault after the new normal test data is tested and calculated, the following Average To update, follow Standard Deviation Update, recalculate the bandwidth coefficient of the assessment parameter envelope at the conversion speed of the corresponding sampling window center point, and update the assessment parameter envelope; , for During the first start The average value of the first assessment parameter correction value corresponding to the sampling windows is For the The first start The first assessment parameter correction value corresponding to the sampling window, For the The first start The first assessment parameter correction value corresponding to the sampling window.

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