An air path fault diagnosis method and system for the starting process of an aeroengine

Abstract

The invention relates to the technical field of aeroengines, and discloses a method and system for diagnosing gas path faults in the starting process of an aeroengine. The method and system for diagnosing gas path faults in the starting process of an aeroengine are used to obtain a mapping relationship between an assessment parameter and a converted speed in a historical starting process, construct an envelope of the assessment parameter, and judge whether the assessment parameter at the converted speed during the test exceeds the envelope, so as to judge whether the engine starting test is a normal start. The method and system for diagnosing gas path faults in the starting process of an aeroengine of the invention can realize automatic data processing, reduce data processing time and debugging times, and provide a basis for adjusting the starter power in a speed range or optimizing the starting fuel supply law.

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:

[0005] A method for diagnosing gas path faults during the starting process of an aircraft engine, comprising:

[0006] Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally;

[0007] 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;

[0008] 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;

[0009] 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;

[0010] 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.

[0011] Further, the assessment parameter curve includes an engine pressure ratio curve, a corrected low-pressure turbine outlet temperature curve, and an acceleration curve corresponding to the engine speed; during the engine start test, if the corrected values of the second assessment parameters corresponding to the engine pressure ratio curve, the corrected low-pressure turbine outlet temperature curve, and the acceleration curve are all within the corresponding envelope ranges, it is determined that the engine start test is a normal start; otherwise, it is determined that a fault has occurred in the engine start test.

[0012] Further, the functional relationship between the parameter values in each acquisition window of each assessment parameter curve and the corrected speed data is obtained by using the least squares method as , where , , where is the parameter correction value of each acquisition window of the corresponding assessment parameter curve, , is the number of assessment parameter values in the corresponding sampling window, takes values of 1, 2, or 3, represents the engine pressure ratio data when represents the corrected low-pressure turbine outlet temperature data when represents the acceleration data when is the th parameter value in each acquisition window of the corresponding assessment curve, is the corrected speed.

[0013] Further, the method for constructing the envelope of the engine assessment parameter varying with the corrected speed includes:

[0014] Using the rule to eliminate the outliers of the corrected values of the first assessment parameter in each sampling window during multiple normal starts of the engine;

[0015] According to the data after outlier elimination, analyze and obtain the average value and standard deviation of the corrected values of the first assessment parameter in each sampling window;

[0016] Using analyze and obtain the value for each normal start in each sampling window, and take the maximum value in normal starts in each sampling window as the bandwidth coefficient of the assessment parameter envelope at the corrected speed of the center point of the corresponding sampling window, is the corrected value of the first assessment parameter corresponding to the th sampling window in one of the normal starts after outlier elimination, is after outlier elimination in the The average value of the first evaluation parameter correction values corresponding to a sampling window After wild point rejection In the Normal starts, the standard deviation of the first evaluation parameter correction values corresponding to the

[0017] Further, if it is determined that there is a fault in the engine start test after the new normal test run data is tested and calculated, then according to Update the average value According to Update the standard deviation Recalculate the bandwidth coefficient at the conversion speed corresponding to the center point of the corresponding sampling window of the evaluation parameter envelope line, and update the envelope line of the evaluation parameter; where , Is In the Normal starts, the average value of the first evaluation parameter correction values corresponding to the Is the At the First evaluation parameter correction value corresponding to the sampling window, Is the At the First evaluation parameter correction value corresponding to the sampling window.

[0018] To achieve the above technical effects, the present invention also provides an air path fault diagnosis system for the starting process of an aeroengine, which is used to implement the air path fault diagnosis method for the starting process of the aeroengine; including:

[0019] A data acquisition module, which is used to acquire the evaluation parameter curve and the conversion speed curve when the engine starts normally;

[0020] A function construction module, which is used to divide the evaluation parameter curve into multiple data acquisition windows in chronological order, and according to the evaluation parameter data values in each acquisition window and the conversion speed data values corresponding to the evaluation parameter data values, use the least squares method to construct the functional relationship between the evaluation parameters and the conversion speed data in each acquisition window;

[0021] A first analysis module, which is used to substitute the conversion speed value at the center point of each acquisition window into the functional relationship to obtain the first evaluation parameter correction value corresponding to the center point of the corresponding acquisition window;

[0022] An envelope line construction module, which is used to construct an envelope line of the engine evaluation parameter varying with the conversion speed according to the first evaluation parameter correction values during multiple normal starts of the engine;

[0023] A discrimination module, which is used to analyze and obtain the corrected value of the second assessment parameter at the center point of each acquisition window during the engine start test according to the converted speed curve and the assessment parameter curve during the engine start test, and determine whether the corrected value of the second assessment parameter exceeds the envelope range in step four. If so, it outputs a judgment result that a fault occurs in the engine start test; if not, it outputs a judgment result that the engine start test is a normal start.

[0024] Further, 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 discrimination module, when the corrected values of the second assessment parameters 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 start test, it is determined that the engine start test is a normal start, otherwise it is determined that a fault occurs in the engine start test.

[0025] Further, in the function construction module, 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 as , where , , where is the parameter correction value of each acquisition window of the corresponding assessment parameter curve, , is the number of assessment parameter values in the corresponding sampling window, takes the value of 1, 2, or 3, represents engine pressure ratio data when represents converted low-pressure turbine outlet temperature data when represents acceleration data when is the th parameter value in each acquisition window of the corresponding assessment curve, is the converted speed.

[0026] Further, in the envelope construction module, the process of constructing the envelope of the engine assessment parameter varying with the converted speed includes:

[0027] Using the rule to eliminate the outliers of the corrected value of the first assessment parameter in each sampling window during multiple normal starts of the engine;

[0028] According to the data after outlier elimination, analyze and obtain the average value and standard deviation of the corrected value of the first assessment parameter in each sampling window;

[0029] Using Analyze and obtain the value of each normal start in each sampling window, and take the value in each sampling window at The maximum value during the next normal start is the bandwidth coefficient of the assessment parameter envelope at the converted speed at the center point of the corresponding sampling window, is the first corrected value of the assessment parameter corresponding to the th sampling window during one of the normal starts after wild point rejection, is after wild point rejection during the th normal start, the average value of the first corrected value of the assessment parameter corresponding to the th sampling window, is during the th normal start, the standard deviation of the first corrected value of the assessment parameter corresponding to the

[0030] Furthermore, in the envelope construction module, when it is determined that there is a fault in the engine start test after the new normal test run data is tested and calculated, then according to update the average value , and according to update the standard deviation , recalculate the bandwidth coefficient of the assessment parameter envelope at the converted speed at the center point of the corresponding sampling window, and update the envelope of the assessment parameter; where , is the average value of the first corrected value of the assessment parameter corresponding to the th sampling window during the th start process, is the first corrected value of the assessment parameter corresponding to the th sampling window during the th start, is the first corrected value of the assessment parameter corresponding to the th sampling window during the th start.

[0031] 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 parameter and the converted speed during the historical start process, constructs the envelope of the assessment parameter, and judges whether the assessment parameter under the converted speed during the test process exceeds the envelope, so as to judge whether the engine start test is a normal start; the air path fault diagnosis method and system for the starting process of the aero-engine of the present invention can realize automatic data processing, reduce the data processing time and the number of 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

[0032] Figure 1 is the flowchart of the air path fault diagnosis method for the starting process of the aero-engine in Embodiment 1 or 2;

[0033] Figure 2 It is the structural block diagram of the gas path fault diagnosis system during the starting process of an aeroengine in Embodiment 1;

[0034] Figure 3 It is the engine pressure ratio envelope diagram in Embodiment 2;

[0035] Among them, 1. Data acquisition module; 2. Function construction module; 3. First analysis module; 4. Envelope construction module; 5. Discrimination module. Specific implementation manners

[0036] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. Any technology implemented based on the content of the present invention belongs to the scope of the present invention.

[0037] Embodiment 1

[0038] Refer to Figure 1 and Figure 2 , a gas path fault diagnosis method during the starting process of an aeroengine, including:

[0039] Step 1: Obtain the assessment parameter curve and conversion speed curve when the engine starts normally;

[0040] Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order. According to the assessment parameter data values in each acquisition window and the corresponding conversion speed data values of the assessment parameter data values, use the least squares method to construct the functional relationship between the assessment parameters and the conversion speed data in each acquisition window;

[0041] Step 3: Substitute the conversion speed value at the center point of each acquisition window into the functional relationship to obtain the first assessment parameter correction value corresponding to the center point of the corresponding acquisition window;

[0042] Step 4: Construct an envelope of the engine assessment parameters varying with the conversion speed according to the first assessment parameter correction values during multiple normal starts of the engine;

[0043] Step 5: Obtain the conversion speed curve and assessment parameter curve during the engine start test. Repeat Steps 2 to 3 to obtain the second assessment parameter correction value at the center point of each acquisition window during the engine start test. Determine whether the second assessment parameter correction value exceeds the envelope range in Step 4. If so, it is determined that a fault occurs during the engine start test; if not, it is determined that the engine start test is a normal start.

[0044] In this embodiment, by obtaining the mapping relationship between the assessment parameters and the converted speed during the historical starting process, constructing the envelope curve of the assessment parameters, and judging the situation where the assessment parameters at the converted speed during the test process exceed the envelope curve, it is determined whether the engine starting test is a normal start; this embodiment can achieve automatic data processing, reduce the data processing time and the number of debugging times, and provide a basis for adjusting the starter power in the speed range or optimizing the starting fuel supply law.

[0045] In this embodiment, the assessment 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; when the corrected values of the second assessment parameters 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 curve range, it is determined that the engine starting test is a normal start, otherwise it is determined that a fault occurs in the engine starting test.

[0046] Based on the same inventive concept, this embodiment also provides an air path fault diagnosis system for the starting process of an aeroengine, including:

[0047] A data acquisition module 1 for acquiring the assessment parameter curve and the converted speed curve when the engine starts normally;

[0048] A function construction module 2 for dividing the assessment parameter curve into multiple data acquisition windows in chronological order, and constructing a functional relationship between the assessment parameters and the converted speed data in each acquisition window according to the assessment parameter data values in each acquisition window and the converted speed data values corresponding to the assessment parameter data values by using the least squares method;

[0049] A first analysis module 3 for substituting the converted speed value at the center point of each acquisition window into the functional relationship to obtain the corrected value of the first assessment parameter corresponding to the center point of the corresponding acquisition window;

[0050] An envelope curve construction module 4 for constructing an envelope curve of the engine assessment parameters varying with the converted speed according to the corrected values of the first assessment parameters during multiple normal starts of the engine;

[0051] A discrimination module 5 for analyzing and obtaining the corrected value of the second assessment parameter at 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 judging whether the corrected value of the second assessment parameter exceeds the envelope curve range in step four. If so, it outputs a judgment result that a fault occurs in the engine starting test; if not, it outputs a judgment result that the engine starting test is a normal start.

[0052] Embodiment 2

[0053] See Figure 1This 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:

[0054] Step 1: Obtain the test parameter curve and the converted speed curve when the engine is started normally;

[0055] 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.

[0056] 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;

[0057] 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 evaluation parameter interval values corresponding to each interval.

[0058] Then, the least squares method is used to fit all the evaluation parameter interval values and the corresponding converted rotational speed values in the interval to obtain an analysis function for the corresponding evaluation parameter; in this embodiment, the functional relationship between the parameter values in each acquisition window of each evaluation parameter curve and the converted rotational speed data obtained by the least squares method is , where , , where is the parameter correction value of each acquisition window of the corresponding evaluation parameter curve, , is the number of evaluation parameter values in the corresponding sampling window, takes values of 1, 2, or 3, represents the engine pressure ratio data when represents the converted low-pressure turbine outlet temperature data when represents the acceleration data when is the th parameter value in each acquisition window of the corresponding evaluation curve, is the converted rotational speed.

[0059] Step 3: Substitute the converted rotational speed value at the center point of each acquisition window into the above functional relationship to obtain the first evaluation parameter correction value corresponding to the center point of the corresponding acquisition window;

[0060] Step 4: Construct an envelope curve of the engine evaluation parameter varying with the converted rotational speed according to the first evaluation parameter correction values during multiple normal starts of the engine;

[0061] In this embodiment, the method for constructing an envelope curve of the engine evaluation parameter varying with the converted rotational speed includes:

[0062] 4.1 Use the rule to eliminate the outliers of the first evaluation parameter correction values of each sampling window during multiple normal starts of the engine;

[0063] 4.2 Analyze and obtain the average value and standard deviation of the first evaluation parameter correction values of each sampling window based on the data after outlier elimination;

[0064] 4.3 Use to analyze and obtain the value of each normal start of each sampling window, and take the maximum value during normal starts of each sampling window as the bandwidth coefficient of the evaluation parameter envelope curve at the converted rotational speed of the center point of the corresponding sampling window, is the correction value of the first evaluation parameter corresponding to the th sampling window during one normal start after wild point rejection, is the average value of the correction values of the first evaluation parameter corresponding to the th normal start after wild point rejection, th sampling window, is the standard deviation of the correction values of the first evaluation parameter corresponding to the th normal start after wild point rejection, th sampling window. The obtained engine pressure ratio envelope is as Figure 3 shown, where represents the upper envelope, represents the lower envelope. The envelopes of other evaluation parameters are similar and will not be elaborated here.

[0065] In this embodiment, according to Chebyshev's inequality, it can be obtained that in a certain start, the first engine pressure ratio acquisition window satisfies , which indicates that the probability that the average value of the first pressure ratio correction values of the first engine pressure ratio acquisition window in starts is in the interval , where is the bandwidth coefficient of the engine envelope at the first engine pressure ratio acquisition window in this start, is the first pressure ratio correction value of the first engine pressure ratio acquisition window in this start, is the average value of the first pressure ratio correction values of the first engine pressure ratio acquisition window in starts, is the standard deviation of the first pressure ratio correction values of the first engine pressure ratio acquisition window in

[0066] Step Five: Obtain the converted speed curve and the evaluation parameter curve during the engine start test, repeat Steps Two to Three, obtain the correction values of the second evaluation parameter at the center point of each acquisition window during the engine start test, and determine whether the correction values of the second evaluation parameter exceed the envelope range in Step Four. If so, it is determined that a fault occurs in the engine start test; if not, it is determined that the engine start test is a normal start.

[0067] In this embodiment, when the correction values of the second evaluation parameter corresponding to the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve, and the acceleration curve during the engine start test are all within the corresponding envelope range, it is determined that the engine start test is a normal start; otherwise, it is determined that a fault occurs in the engine start test.

[0068] Step 6. If it is determined that there is a failure in the engine start test after the new normal commissioning data is tested and calculated, then according to Update the average value According to Update the standard deviation Recalculate the bandwidth coefficient at the converted speed at the center point of the corresponding sampling window of the assessment parameter envelope line, and update the envelope line of the assessment parameter; where , Is The average value of the first assessment parameter correction values corresponding to the th sampling window during the th start, Is the first assessment parameter correction value corresponding to the th sampling window during the th start, Is the first assessment parameter correction value corresponding to the th sampling window during the

[0069] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within 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: obtaining an assessment parameter curve and a converted speed curve when the engine is started normally, wherein 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; Step 2: Divide the assessment parameter curve into multiple data acquisition windows in chronological order, and construct a functional relationship between the assessment parameter data value and the converted speed data value in each data acquisition window using the least squares method according to the assessment parameter data value in each data acquisition window and the converted speed data value corresponding to the assessment parameter data value; Step 3, substituting the converted speed data value of each data acquisition window center point into the functional relationship to obtain the first assessment parameter correction value corresponding to the corresponding data 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 data acquisition window during the engine starting test, and determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If the second assessment parameter correction value corresponding to the engine pressure ratio curve, the converted low-pressure turbine outlet temperature curve, and the acceleration curve corresponding to the engine speed during the engine starting test are all within the corresponding envelope range, the engine starting test is judged to be a normal start, otherwise the engine starting test is judged to be a fault.

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 functional relationship between the assessment parameter data value and the converted speed data value in each data acquisition window is constructed using the least squares method: ,in , ,in is the parameter correction value of each data acquisition window corresponding to the assessment parameter curve, , is the number of assessment parameter data values ​​in the corresponding data collection 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, The first parameter values, It is the converted speed data value.

3. 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 corrected value of the first assessment parameter in each sampling window are analyzed; 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 envelope of the assessment parameter changing with the converted speed at the corresponding sampling window center point converted speed. 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.

4. The method for diagnosing gas path faults during the start-up process of an aircraft engine according to claim 3, 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 envelope of the assessment parameter changing with the converted speed at the converted speed of the corresponding sampling window center point, and update the envelope of the assessment parameter changing with the converted speed; , 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.

5. 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, used to acquire an assessment parameter curve and a converted speed curve when the engine is normally started, wherein 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; A function construction module, for dividing the assessment parameter curve into a plurality of data acquisition windows in chronological order, and constructing a functional relationship between the assessment parameter data value and the converted speed data value in each data acquisition window by using the least square method according to the assessment parameter data value in each data 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 speed data value of each data acquisition window center point into the functional relationship to obtain a first assessment parameter correction value corresponding to the corresponding data 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 data 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 determine whether the second assessment parameter correction value exceeds the envelope range in step 4. If 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 corresponding to the engine speed during the engine starting test are all within the corresponding envelope range, the engine starting test is judged to be a normal start; otherwise, the engine starting test is judged to be faulty.

6. The air path fault diagnosis system for the aircraft engine starting process according to claim 5, characterized in that: In the function construction module, the least square method is used to construct the functional relationship between the assessment parameter data value and the converted speed data value in each data acquisition window: ,in , ,in is the parameter correction value of each data acquisition window corresponding to the assessment parameter curve, , is the number of assessment parameter data values ​​in the corresponding data collection 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, The first parameter values, It is the converted speed data value.

7. The air path fault diagnosis system for the aircraft engine starting process according to claim 5, 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 corrected value of the first assessment parameter in each sampling window are analyzed; 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 envelope of the assessment parameter changing with the converted speed at the corresponding sampling window center point converted speed. 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.

8. The air path fault diagnosis system for the aircraft engine starting process according to claim 7, 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 envelope of the assessment parameter changing with the converted speed at the converted speed of the corresponding sampling window center point, and update the envelope of the assessment parameter changing with the converted speed; , 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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