Helicopter blade load data test validity detection and judgment method and device

Abstract

The invention provides a helicopter blade load data test validity detection and judgment method and device. The method comprises the following steps: firstly, selecting normal blade load data and detected sortie blade load data under the same characteristic state; phase alignment is carried out on the selected two groups of data, and load data in two rotation periods are selected from each of the two groups of data; carrying out abnormal value judgment on the selected load data, and carrying out abnormal value elimination and point supplementation operation to obtain two groups of corrected blade load data; carrying out correlation calculation on the two groups of corrected blade load data to obtain a correlation coefficient R; finally, the obtained correlation coefficient R is compared with a set threshold value, whether the tested sortie blade load data test is effective or not is judged, monitoring faults caused by test faults can be recognized, the fault range can be prompted, monitoring personnel can be assisted in judging the problems, and flight safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of helicopter flight load testing, and in particular relates to a method and a device for testing the effectiveness of helicopter blade load data. Background Art

[0002] Helicopter flight load testing is an important part of helicopter flight testing. It is the only means to verify the reliability of the helicopter's blade structure and evaluate its service life. New helicopters must fully verify their blades through flight load testing before they are finalized.

[0003] The helicopter blade load test system is responsible for testing and recording data, so it is necessary to ensure the accuracy of the measured data. Currently, it is extremely difficult to manually judge whether the data is abnormal, and it is easy to make mistakes. Summary of the invention

[0004] In order to solve the problem that it is extremely difficult and easy to make mistakes in the prior art to manually judge whether the data is abnormal, the present invention provides a method and device for checking the effectiveness of helicopter blade load data test, which can be used for the characteristic effectiveness of helicopter blade load measured data, realize the evaluation and monitoring of the working stability of the test system, avoid invalid flights caused by abnormal test data in advance, and improve the comprehensive efficiency of flight test work. The technical solution is as follows:

[0005] In a first aspect, a method for testing the effectiveness of helicopter blade load data is provided, the method comprising:

[0006] Step 1: Select normal blade load data under the same characteristic state and the blade load data of the inspected flight;

[0007] Step 2: Phase align the two selected data sets, and select load data within 2 rotation periods from each of the two data sets;

[0008] Step 3: Perform outlier judgment on the selected load data, remove outliers and fill in points to obtain two sets of corrected blade load data;

[0009] Step 4: Calculate the correlation between the two sets of corrected blade load data to obtain the correlation coefficient R;

[0010] Step 5: Compare the obtained correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

[0011] Under a specific driving state, the frequency components and time domain amplitudes of the flight loads of helicopter blades are similar and will not change significantly. Therefore, by comparing the correlation of blade load data under normal and target states, it can be used to analyze the characteristic validity of the measured data of helicopter blade loads, evaluate and monitor the working stability of the test system, and avoid invalid flights caused by abnormal test data in advance.

[0012] Optionally, in step 1, the characteristic state is an idle state, that is, the total pitch = 0, and the rotor speed Nr = the ground idle start state speed.

[0013] Optionally, in step 2, when selecting load data within 2 rotation cycles, the number of selected data points = 2*60*f / Nr, where f is the sampling rate, and its true value is greater than Nr*200 / 60; Nr is the rotor speed; and 2 is the number of cycles.

[0014] Optionally, in step 2, the selected starting point N is at the peak of the blade load time domain curve.

[0015] Optionally, in step 3, the outlier judgment process is:

[0016] The slope of the adjacent points of the inspected blade load data point is K∈(-2f, 2f). If the slope exceeds the range, the latter point of the two points is eliminated, and the subsequent point and its previous point are selected to recalculate the slope. At this time, the slope of the two adjacent points is K∈(-4f, 4f). If the slope continues to exceed this range, the newly selected subsequent point is eliminated, and the next new subsequent point is selected again and its previous point is recalculated. At this time, the slope of the two adjacent points is K∈(-6f, 6f). If the slope is still not satisfied, it is determined that the data point of this complete cycle is unavailable, and the data point of the next cycle is selected. If it is satisfied, it is calculated backward until all abnormal points are eliminated and the correlation is calculated.

[0017] Optionally,

[0018] After eliminating abnormal points in the blade load data of the inspected flight, the data points at the corresponding positions of the normal blade load data should be eliminated to ensure that the number of data points in the two groups is consistent, and then calculate the correlation, and the total number of eliminated points should not exceed 1% of the total number of points.

[0019] Optionally, in step 5, the threshold is set to 0.9. If the correlation R>0.9, the blade load data test of the inspected flight is determined to be valid. If the correlation R≤0.9, the blade load data test of the inspected flight is determined to be invalid.

[0020] In a second aspect, a method and device for checking the effectiveness of helicopter blade load data testing is provided, comprising:

[0021] A selection module is used to select normal blade load data under the same characteristic state and blade load data of the inspected flight;

[0022] A processing module, used for performing phase alignment on the two selected sets of data, and selecting load data within two rotation periods from each of the two sets of data;

[0023] A judgment module is used to judge the outliers of the selected load data, remove the outliers and fill in the points to obtain two sets of corrected blade load data;

[0024] A calculation module is used to perform correlation calculation on the two sets of corrected blade load data to obtain a correlation coefficient R;

[0025] The comparison module is used to compare the obtained correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

[0026] In a third aspect, a method and device for checking the effectiveness of a helicopter blade load data test is provided, comprising a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and the processor implements a method for checking the effectiveness of a helicopter blade load data test as described in any one of the first aspects by executing the instructions.

[0027] In a fourth aspect, a computer-readable storage medium is provided, wherein instructions are stored in the computer-readable storage medium. When the instructions are executed on a processing component of a computer, the processing component executes a method for checking the validity of a helicopter blade load data test as described in any one of the first aspects.

[0028] In a fifth aspect, a computer program product comprising instructions is provided. When the computer program product is run on a computer, the computer is caused to execute a method for checking the effectiveness of a helicopter blade load data test as described in any one of the first aspects.

[0029] The beneficial effects of the present invention are at least:

[0030] The present invention first selects normal blade load data under the same characteristic state and blade load data of the inspected flight; performs phase alignment on the two selected data sets, and selects load data within 2 rotation cycles in each of the two data sets; then performs outlier judgment on the selected load data, performs outlier elimination and point filling operations, and obtains two corrected blade load data sets; then performs correlation calculation on the two corrected blade load data sets to obtain a correlation coefficient R; finally, the obtained correlation coefficient R is compared with a set threshold value to determine whether the blade load data test of the inspected flight is valid, and can identify monitoring faults caused by test faults, prompt the fault range, assist monitoring personnel in judging problems, and ensure flight safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1A schematic diagram of a method for checking the effectiveness of helicopter blade load data testing provided by an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of normal data and test data curves of Example 1 of the present invention;

[0033] Figure 3 This is a schematic diagram of the test data curve of Example 2 of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below through specific implementation modes and drawings.

[0035] The present invention can provide guidance for the validity check of helicopter blade load data, and can be used for the validity check of large quantities of data tests, thereby eliminating errors and abnormal data caused by test system failures, thereby reducing the impact on subsequent load calculations.

[0036] See also Figure 1 The present invention provides a method for testing the effectiveness of helicopter blade load data, the main steps of which are as follows:

[0037] Step 1: Select normal blade load data under the same characteristic state and the blade load data of the inspected flight.

[0038] The characteristic state requirement is the slow-start state, that is, the total pitch = 0, and the rotor speed Nr = the ground slow-start state speed.

[0039] Step 2: Phase align the two selected data sets, and select load data within 2 rotation periods from each of the two data sets;

[0040] When selecting load data within 2 rotation cycles, the number of selected data points = 2*60*f / Nr, where f is the sampling rate, and its true value is usually greater than Nr*200 / 60; Nr is the rotor speed; and 2 is the number of cycles.

[0041] The selected starting point N is at the peak of the blade load time domain curve. Figure 2 shown.

[0042] Step 3: judge the outliers of the selected load data, remove the outliers and fill in the points to obtain two sets of corrected blade load data;

[0043] In one possible implementation, the outlier determination process is as follows:

[0044] The slope of the adjacent points of the inspected blade load data point is K∈(-2f, 2f). If the slope exceeds the range, the latter point of the two points is eliminated, and the subsequent point and its previous point are selected to recalculate the slope. At this time, the slope of the two adjacent points is K∈(-4f, 4f). If the slope continues to exceed this range, the newly selected subsequent point is eliminated, and the next new subsequent point and its previous point are selected again to recalculate the slope. At this time, the slope of the two adjacent points is K∈(-6f, 6f). If the slope still does not meet the requirements, it is determined that the data points of this complete cycle are unavailable (if there are not enough data points for continuous selection, this determination will not be made), and selection will start from the next cycle data point. If it meets the requirements, calculation will be continued until all abnormal points are eliminated and the correlation is calculated.

[0045] After eliminating abnormal points in the blade load data of the inspected flight, the data points at the corresponding positions of the normal blade load data should be eliminated to ensure that the number of data points in the two groups is consistent, and then the correlation is calculated. In order to avoid data distortion, the total number of eliminated points should not exceed 1% of the total number of points.

[0046] Step 4: Calculate the correlation between the two sets of corrected blade load data to obtain the correlation coefficient R, which is calculated as follows:

[0047]

[0048] Step 5: Compare the calculated correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

[0049] For example, when the threshold is set to 0.9 and the correlation N>0.9, the data is normal. When the correlation is between 0.8 and 0.9, manual judgment is required to check whether the abnormal points are removed and repaired, resulting in similarity distortion. If so, a clean test sample is selected and recalculated. If not, the test channel is faulty. When N<0.8, the test channel is faulty and needs to be repaired.

[0050] In one embodiment, if Figure 2 As shown in the figure, it is a comparison chart of two periodic signals of a certain load data. The dotted line represents normal data, and the solid line represents the current test data. After correlation calculation, the correlation degree of the two signals is 0.9769. Therefore, it is considered that the data of this test channel is normal.

[0051] In one embodiment, if Figure 3 As shown, it is a load signal with a sampling rate of 1024. The slopes from point 1 to point 2, point 3, and point 4 are 7652760, 5402594, and 4119642, respectively, which are much larger than those determined in step 3 of the method. Therefore, this test data cannot be determined.

[0052] An embodiment of the present invention further provides a method and device for testing the effectiveness of helicopter blade load data, comprising:

[0053] A selection module is used to select normal blade load data under the same characteristic state and blade load data of the inspected flight;

[0054] A processing module, used for performing phase alignment on the two selected sets of data, and selecting load data within two rotation periods from each of the two sets of data;

[0055] A judgment module is used to judge the outliers of the selected load data, remove the outliers and fill in the points to obtain two sets of corrected blade load data;

[0056] A calculation module is used to perform correlation calculation on the two sets of corrected blade load data to obtain a correlation coefficient R;

[0057] The comparison module is used to compare the obtained correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

[0058] The specific execution process of each module in the present invention can refer to the specific process of the relevant steps of the above method, which will not be repeated here.

[0059] An embodiment of the present invention also provides a method and device for checking the effectiveness of a helicopter blade load data test, comprising a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and the processor implements a method for checking the effectiveness of a helicopter blade load data test provided by the present invention by executing the instructions.

[0060] An embodiment of the present invention further provides a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a processing component of a computer, the processing component executes a method for checking the effectiveness of a helicopter blade load data test provided by the present invention.

[0061] An embodiment of the present invention further provides a computer program product comprising instructions, and when the computer program product is run on a computer, the computer is enabled to execute a method for checking the effectiveness of a helicopter blade load data test provided by the present invention.

[0062] The above only expresses the implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.

Claims

1. A method for testing the effectiveness of helicopter blade load data, characterized in that: The method comprises: Step 1: Select normal blade load data under the same characteristic state and the blade load data of the inspected flight; Step 2: Phase align the two selected data sets, and select load data within 2 rotation periods from each of the two data sets; Step 3: Perform outlier judgment on the selected load data, remove outliers and fill in points to obtain two sets of corrected blade load data; Step 4: Calculate the correlation between the two sets of corrected blade load data to obtain the correlation coefficient R; Step 5: Compare the obtained correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

2. The method according to claim 1, characterized in that In step 1, the characteristic state is the slow-speed state, that is, the total pitch = 0, and the rotor speed Nr = the ground slow-speed start-up state speed.

3. The method according to claim 1, characterized in that In step 2, when selecting load data within 2 rotation cycles, the number of selected data points = 2*60*f / Nr, where f is the sampling rate, and its true value is greater than Nr*200 / 60; Nr is the rotor speed; and 2 is the number of cycles.

4. The method according to claim 1, characterized in that In step 2, the starting point N is selected at the peak of the blade load time domain curve.

5. The method according to claim 1, characterized in that In step 3, the outlier judgment process is: The slope of the adjacent points of the inspected blade load data point is K∈(-2f, 2f). If the slope exceeds the range, the latter point of the two points is eliminated, and the subsequent point and its previous point are selected to recalculate the slope. At this time, the slope of the two adjacent points is K∈(-4f, 4f). If the slope continues to exceed this range, the newly selected subsequent point is eliminated, and the next new subsequent point is selected again and its previous point is recalculated. At this time, the slope of the two adjacent points is K∈(-6f, 6f). If the slope is still not satisfied, it is determined that the data point of this complete cycle is unavailable, and the data point of the next cycle is selected. If it is satisfied, it is calculated backward until all abnormal points are eliminated and the correlation is calculated.

6. The method according to claim 5, characterized in that After eliminating abnormal points in the blade load data of the inspected flight, the data points at the corresponding positions of the normal blade load data should be eliminated to ensure that the number of data points in the two groups is consistent, and then calculate the correlation, and the total number of eliminated points should not exceed 1% of the total number of points.

7. The method according to claim 1, characterized in that In step 5, the threshold is set to 0.

9. If the correlation R>0.9, it is determined that the blade load data test of the inspected flight is valid. If the correlation R≤0.9, it is determined that the blade load data test of the inspected flight is invalid.

8. A method and device for checking the effectiveness of helicopter blade load data testing, characterized in that: include: A selection module is used to select normal blade load data under the same characteristic state and blade load data of the inspected flight; A processing module, used for performing phase alignment on the two selected sets of data, and selecting load data within two rotation periods from each of the two sets of data; A judgment module is used to judge the outliers of the selected load data, remove the outliers and fill in the points to obtain two sets of corrected blade load data; A calculation module is used to perform correlation calculation on the two sets of corrected blade load data to obtain a correlation coefficient R; The comparison module is used to compare the obtained correlation coefficient R with the set threshold value to determine whether the blade load data test of the inspected flight is valid.

9. A method and device for checking the effectiveness of helicopter blade load data testing, characterized in that: The invention comprises a processor and a memory, wherein the processor is configured to execute instructions stored in the memory, and the processor implements a method for checking the effectiveness of a helicopter blade load data test as described in any one of claims 1 to 7 by executing the instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores instructions, and when the instructions are executed on a processing component of a computer, the processing component executes a method for checking the effectiveness of a helicopter blade load data test as described in any one of claims 1 to 7.

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