Helicopter transmission shaft displacement test method, device, equipment and medium under airborne environment

Abstract

The application discloses a helicopter transmission shaft displacement test method, device, equipment and medium in an airborne environment, and the method comprises the following steps: S1, during the operation of a helicopter power system, synchronously collecting the vibration displacement signal of an eddy current displacement sensor, the three-direction vibration acceleration signals of a three-direction vibration acceleration sensor at a support, and flight parameter signals; S2, establishing the transfer coefficient between the test end S point of the eddy current displacement sensor and the A point of the three-direction vibration acceleration sensor, and constructing a transfer coefficient library under a real working condition; S3, obtaining the three-direction displacement signals at the S point based on the transfer coefficient library under the real working condition; and S4, obtaining the corrected real displacement of the transmission shaft by combining the size of the measured transmission shaft, the initial installation position, and the three-direction displacement signals of the eddy current displacement sensor itself. The application can remove the vibration signal component of the eddy current displacement sensor itself caused by the vibration of the nacelle during the test, obtain the real transmission shaft displacement, and improve the measurement accuracy.

Description

Technical Field

[0001] This application relates to the field of helicopter drive shaft testing technology, and in particular to methods, devices, equipment and media for testing helicopter drive shaft displacement in an airborne environment. Background Technology

[0002] The driveshaft is a critical component of the helicopter power system, and its operation directly affects aircraft safety. To monitor the driveshaft's condition and assess its operational health under airborne conditions, it is necessary to test its displacement. Currently, eddy current displacement sensors are typically mounted directly on the engine or transmission system casing to test the driveshaft displacement signal. However, helicopter power systems operate under various rotational excitation sources, resulting in harsh vibration environments and complex vibration responses. Influenced by the vibration of the helicopter power system casing itself, the eddy current sensor will also generate corresponding vibration displacement, inevitably causing the casing vibration response component to be superimposed on the tested driveshaft displacement signal, affecting the accuracy of the signal. To accurately test the driveshaft displacement, the influence of casing vibration on the eddy current sensor's own vibration must be eliminated.

[0003] like Figure 1 As shown, in existing technologies, the eddy current sensor bracket is directly fixed to the power system casing, and the sensor itself vibrates simultaneously with the casing. The measured vibration displacement signal X(t) reflects the superposition of the drive shaft vibration displacement and the sensor's own vibration displacement. Directly selecting the peak-to-peak value of the displacement signal as the drive shaft displacement during data processing is clearly erroneous. Due to the complexity of the airborne vibration environment and the spatial constraints of helicopter structures, eddy current displacement sensors cannot be directly mounted on a stationary platform, resulting in lower accuracy of the helicopter power system drive shaft displacement monitoring results. Summary of the Invention

[0004] This application provides a method for testing the displacement of helicopter drive shafts in an airborne environment, which addresses the technical problem of low accuracy in existing test results of helicopter drive shaft displacement in an airborne environment.

[0005] This application is achieved through the following solution:

[0006] A method for testing helicopter drive shaft displacement under airborne conditions, including the following steps:

[0007] S1. During the operation of the helicopter power system, the vibration displacement signal of the eddy current displacement sensor, the vibration acceleration signal in three directions of the triaxial vibration acceleration sensor at the support of the eddy current displacement sensor, and the helicopter flight parameter signal are collected synchronously.

[0008] S2. Establish the transfer coefficient between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor of the eddy current displacement sensor bracket. By associating with helicopter flight parameters, link the transfer coefficient with the actual working conditions of the helicopter and build a library of transfer coefficients under actual working conditions.

[0009] S3. Based on the transfer coefficient library under real working conditions, the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor is obtained as the triaxial displacement signal of the eddy current displacement sensor itself.

[0010] S4. Combine the dimensions of the tested drive shaft itself, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor to correct the vibration displacement signal of the eddy current displacement sensor, and obtain the corrected true displacement of the drive shaft.

[0011] Furthermore, step S2 specifically includes the following steps:

[0012] S21. During the helicopter ground test, a triaxial displacement test is performed at point S on the eddy current displacement sensor test end, and a triaxial acceleration test is performed at point A on the eddy current displacement sensor support. The transfer coefficient matrix H from point A to point S is obtained. Different helicopter operating conditions are simulated, and a preliminary library of transfer coefficients under different operating conditions is established. The transmission coefficient H SA for:

[0013] ;

[0014] Where: each element in the matrix This indicates the input port (point A). Directional physical quantity to the output port (point S) Transmission coefficient of directional physical quantities ;

[0015] S22. Under the actual working conditions of the helicopter power system, the triaxial acceleration signal of the eddy current displacement sensor bracket, the triaxial displacement signal at point S of the eddy current displacement sensor test end, and the helicopter flight parameter signal are synchronously collected.

[0016] S23. Data processing is performed using a signal analysis method with high time-frequency resolution, followed by time-frequency filtering to eliminate interference and noise, extract the amplitude of the main order time-frequency ridges of the measured transmission shaft under real working conditions, and accurately capture transient characteristics.

[0017] S24. Divide the time-frequency ridges of the same order to obtain the transfer coefficient at the corresponding frequency, and smooth the transfer coefficient to eliminate interference.

[0018] S25. Correlate the transfer coefficients with the helicopter flight parameter signals, link the transfer coefficients with the actual operating conditions of the helicopter, and construct a transfer coefficient library under the actual operating conditions.

[0019] Furthermore, different helicopter operating conditions include ground slow speed, air slow speed, hovering, level flight, climb, turn, and dive; signal analysis methods with high time-frequency resolution include synchronous compressed wavelet transform method and parameterized time-frequency analysis method.

[0020] Furthermore, step S3 specifically includes the following steps:

[0021] S31. Perform synchronous compressed wavelet transform on the vibration acceleration signals in the three directions of the collected triaxial vibration acceleration sensor, extract the relevant fundamental frequency and its harmonic ridge of the measured axis, eliminate noise and interference, and retain transient characteristic information;

[0022] S32. Using helicopter flight parameter signals, obtain flight parameter information at any time in the synchronous compressed wavelet transform time-frequency matrix, and then correlate the transfer coefficients of the corresponding fundamental frequency and its harmonic amplitude in the transfer coefficient library. The relevant displacement frequency and its harmonic amplitude information at point S, the test end of the eddy current displacement sensor, are obtained, and the displacement time-frequency matrix at point S, the test end of the eddy current displacement sensor, is obtained:

[0023] ;

[0024] in, f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer. , , representing the time-frequency matrix in three directions; The amplitude of the time-frequency ridge line extracted from the synchronous compression transformation of the signal; for Synchronous compressed wavelet transform, ;

[0025] S33. Perform synchronous compressed wavelet inverse transform on the displacement time-frequency signal at point S of the eddy current displacement sensor test end to obtain the triaxial displacement time-domain signal at point S of the eddy current displacement sensor test end as the triaxial displacement signal of the eddy current displacement sensor itself:

[0026] ;

[0027] in, , This represents the time-domain displacement signal in three directions at point S, the test end of the eddy current displacement sensor. This is for the calculation of synchronous compression inverse transform.

[0028] Furthermore, step S4 specifically includes the following steps:

[0029] S41. Consider the displacement correction in the z-direction of the eddy current displacement sensor itself: Calculate the change in gap between the eddy current displacement sensor probe and the measured transmission shaft based on the displacement in the z-direction of the eddy current displacement sensor itself. :

[0030] ;

[0031] in, R The radius of the drive shaft. θ The angle formed by the z-direction movement of the eddy current displacement sensor itself:

[0032] ;

[0033] S42. Considering the displacement correction in the x-direction of the eddy current displacement sensor itself: The x-direction motion of the eddy current displacement sensor itself and the collected eddy current displacement sensor vibration displacement signal X(t) are on the same axis. The collected eddy current displacement sensor vibration displacement signal X(t) is directly subtracted from the eddy current displacement sensor's own x-axis three-dimensional displacement signal. ;

[0034] S43. Consider the displacement correction in the y-direction of the eddy current displacement sensor itself: When the eddy current displacement sensor itself moves in the y-direction, it is equivalent to the sensor displacement probe moving parallel to the transmission shaft, directly ignoring the influence of the y-direction movement of the displacement sensor itself on the collected vibration displacement signal of the eddy current displacement sensor.

[0035] S44. The true displacement of the transmission shaft is obtained by correcting the x-axis and z-axis displacements of the eddy current displacement sensor itself and the change in the gap δ between the eddy current displacement sensor probe and the transmission shaft being measured.

[0036] Further, step S44 includes the following steps:

[0037] S441. Obtain the corrected true displacement of the drive shaft based on the x- and z-direction displacements of the eddy current displacement sensor itself. for:

[0038] .

[0039] Further, step S44 includes the following steps:

[0040] S441. Obtain the corrected displacement synchronous compressed wavelet transform time-frequency matrix through synchronous compressed wavelet transform and ridge amplitude extraction. :

[0041] ;

[0042] in, The time-frequency ridge amplitude is extracted from the vibration displacement signal X(t) acquired by the eddy current displacement sensor through synchronous compressed wavelet transform. f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer;

[0043] S442, to Perform a synchronous compressed wavelet transform inverse to obtain the corrected true displacement of the drive shaft. :

[0044] ;

[0045] in, This is for synchronous compression inverse transform calculation.

[0046] This application also provides a helicopter drive shaft displacement testing device under airborne conditions, including:

[0047] The data acquisition module is used to synchronously acquire vibration displacement signals from the eddy current displacement sensor, vibration acceleration signals in three directions from the triaxial vibration acceleration sensor at the eddy current displacement sensor bracket, and helicopter flight parameter signals during the operation of the helicopter power system.

[0048] The transfer coefficient library construction module is used to establish the transfer coefficient between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor of the eddy current displacement sensor bracket. By associating with helicopter flight parameters, the transfer coefficient is linked with the actual working conditions of the helicopter to build a transfer coefficient library under actual working conditions.

[0049] The triaxial displacement signal calculation module is used to obtain the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor based on the transfer coefficient library under real working conditions, and use it as the triaxial displacement signal of the eddy current displacement sensor itself.

[0050] The displacement correction module is used to correct the vibration displacement signal of the eddy current displacement sensor by combining the size of the transmission shaft under test, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor itself, so as to obtain the corrected true displacement of the transmission shaft.

[0051] This application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein the processor executes the computer program to implement the steps of the helicopter drive shaft displacement testing method under airborne conditions.

[0052] This application also provides a storage medium including a stored program that, when the program is executed, controls the device where the storage medium is located to perform the steps of the helicopter drive shaft displacement test method under airborne conditions.

[0053] Compared with the prior art, this application has the following advantages:

[0054] This application provides a method, apparatus, equipment, and storage medium for testing helicopter driveshaft displacement under airborne conditions. Firstly, it adds a triaxial vibration acceleration sensor to the existing eddy current displacement sensor test end. During testing, both the eddy current displacement sensor signal and the triaxial vibration acceleration signal are simultaneously acquired, providing a foundation for removing vibration displacement caused by the chassis environment vibration of the eddy current displacement sensor itself during subsequent testing. Secondly, this application proposes a method for constructing a transfer coefficient library under real-world operating conditions, demonstrating how to obtain the transfer coefficients associated with the operating conditions by processing bench test data, thus supporting the acquisition of the sensor's own vibration displacement data. Simultaneously, based on high-precision time-frequency matrix displacement data correction technology, this application proposes how to correct the eddy current displacement sensor signal using the triaxial acceleration vibration signal on the eddy current displacement sensor, thereby obtaining the true displacement information of the driveshaft. Compared with existing technologies, this application considers the influence of casing vibration on the test signal of eddy current displacement sensor under complex airborne vibration environment. Through data correction, the sensor's own vibration can be removed. The component of the eddy current displacement sensor's own vibration signal caused by casing vibration is removed from the tested displacement signal to obtain the true drive shaft displacement. This enables the engineering application and implementation of the drive shaft displacement test scheme under airborne environment, achieving the goal of engineering application of true drive shaft displacement test.

[0055] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0056] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0057] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0058] Figure 1 This is a schematic diagram of the existing transmission shaft vibration displacement testing principle;

[0059] Figure 2 This is a schematic diagram of the transmission shaft displacement testing principle of this application;

[0060] Figure 3 This is a schematic flowchart of a helicopter drive shaft displacement testing method under airborne conditions according to a preferred embodiment of this application;

[0061] Figure 4 This is a schematic diagram of the z-direction motion test correction of the eddy current displacement sensor according to a preferred embodiment of this application;

[0062] Figure 5 This is a schematic diagram of a helicopter drive shaft displacement testing device module under airborne conditions according to a preferred embodiment of this application;

[0063] Figure 6 This is a schematic block diagram of an electronic device according to a preferred embodiment of this application;

[0064] Figure 7 This is an internal structural diagram of a computer device according to a preferred embodiment of this application. Detailed Implementation

[0065] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0066] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0067] It should be noted that the executing entity in this embodiment can be a computing service device with data processing, network communication, and program execution functions, such as a tablet computer, personal computer, or mobile phone, or a helicopter drive shaft displacement testing device capable of performing the above functions in an airborne environment, such as... Figure 2 This application presents an improved sensor installation scheme. Traditional eddy current sensor displacement testing schemes are susceptible to interference from chassis vibration and are unsuitable for transmission shaft displacement testing in helicopter airborne environments. Other non-traditional displacement testing schemes either have excessively high testing modification costs or are difficult to implement under airborne conditions. This application, based on current airborne displacement testing technology, adds a three-dimensional vibration acceleration sensor to the eddy current displacement sensor bracket mounting base. During the operation of the helicopter power system, the vibration acceleration signals x(t), y(t), and z(t) in three directions from the three-dimensional acceleration sensor at the bracket, the vibration displacement signal X(t) from the eddy current displacement sensor, and flight parameter signals are simultaneously acquired. This scheme requires no additional testing hardware or devices, is easy to implement, and has minimal impact on airborne testing resources. The following uses a helicopter transmission shaft displacement testing device under airborne conditions as the main execution example to illustrate this embodiment and the subsequent embodiments.

[0068] like Figure 3 As shown, a preferred embodiment of this application provides a method for testing the displacement of a helicopter drive shaft in an airborne environment, including the following steps:

[0069] S1. During the operation of the helicopter power system, the vibration displacement signal of the eddy current displacement sensor, the vibration acceleration signal in three directions of the triaxial vibration acceleration sensor at the support of the eddy current displacement sensor, and the helicopter flight parameter signal are collected synchronously.

[0070] S2. Establish the transfer coefficient between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor of the eddy current displacement sensor bracket. By associating with helicopter flight parameters, link the transfer coefficient with the actual working conditions of the helicopter and build a library of transfer coefficients under actual working conditions.

[0071] S3. Based on the transfer coefficient library under real working conditions, the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor is obtained as the triaxial displacement signal of the eddy current displacement sensor itself.

[0072] S4. Combine the dimensions of the tested drive shaft itself, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor to correct the vibration displacement signal of the eddy current displacement sensor, and obtain the corrected true displacement of the drive shaft.

[0073] This embodiment provides a method for testing the displacement of a helicopter driveshaft in an airborne environment. Firstly, a triaxial vibration acceleration sensor is added to the existing eddy current displacement sensor test end. During testing, both the eddy current displacement sensor signal and the triaxial vibration acceleration signal are simultaneously acquired, providing a foundation for removing vibration displacements caused by environmental vibrations in the casing that affect the eddy current displacement sensor itself during subsequent testing. Secondly, this embodiment proposes a method for constructing a transfer coefficient library under real-world operating conditions, demonstrating how to obtain condition-related transfer coefficients by processing bench test data, thus supporting the acquisition of the sensor's own vibration displacement data. Furthermore, based on high-precision time-frequency matrix displacement data correction technology, this embodiment proposes how to correct the eddy current displacement sensor signal using the triaxial acceleration vibration signal from the eddy current displacement sensor, thereby obtaining the true displacement information of the driveshaft. Compared with existing technologies, this embodiment fully considers the influence of casing vibration on the test signal of eddy current displacement sensor under complex airborne vibration environment. Through data correction, the sensor's own vibration can be removed. The component of the eddy current displacement sensor's own vibration signal caused by casing vibration is removed from the tested displacement signal to obtain the true drive shaft displacement. This realizes the engineering application and implementation of the drive shaft displacement test scheme under airborne environment, and achieves the purpose of engineering application of true drive shaft displacement test.

[0074] Preferably, step S2 specifically includes the following steps:

[0075] S21. During the helicopter ground test, a triaxial displacement test is performed at point S on the eddy current displacement sensor test end, and a triaxial acceleration test is performed at point A on the eddy current displacement sensor support. The transfer coefficient matrix H from point A to point S is obtained. Different helicopter operating conditions are simulated, and a preliminary library of transfer coefficients under different operating conditions is established. The transmission coefficient H SA for:

[0076] (1);

[0077] Where: each element in the matrix This indicates the input port (point A). Directional physical quantity to the output port (point S) Transmission coefficient of directional physical quantities ;

[0078] S22. Under the actual working conditions of the helicopter power system, the triaxial acceleration signal of the eddy current displacement sensor bracket, the triaxial displacement signal at point S of the eddy current displacement sensor test end, and the helicopter flight parameter signal are synchronously collected.

[0079] S23. Data processing is performed using a signal analysis method with high time-frequency resolution, followed by time-frequency filtering to eliminate interference and noise, extract the amplitude of the main order time-frequency ridges of the measured transmission shaft under real working conditions, and accurately capture transient characteristics.

[0080] S24. Divide the time-frequency ridges of the same order to obtain the transfer coefficient at the corresponding frequency, and smooth the transfer coefficient to eliminate interference.

[0081] S25. Correlate the transfer coefficients with the helicopter flight parameter signals, link the transfer coefficients with the actual operating conditions of the helicopter, and construct a transfer coefficient library under the actual operating conditions.

[0082] The main challenge in calibrating transfer coefficients lies in the complex dynamic environment during helicopter maneuvers. Test signals are affected by wideband aerodynamic excitation responses, mechanical shocks, electromagnetic interference, and speed fluctuations. Traditional spectral analysis and short-time Fourier transforms cannot accurately capture transient response characteristics or handle speed fluctuations and signal interference, leading to distortion of the extracted transfer function. This embodiment first synchronously acquires the three-dimensional acceleration signal of the support frame, the three-dimensional displacement signal at point S of the eddy current displacement sensor, and flight parameters. Then, it employs signal analysis methods with high time-frequency resolution, such as synchronous compressed wavelet transform and parametric time-frequency analysis, to process the data. Time-frequency filtering is performed to eliminate interference and noise, extracting the amplitude of the main order time-frequency ridges of the tested drive shaft under real-world conditions. This accurately captures transient characteristics and better addresses signal interference and non-stationarity issues during helicopter maneuvers. Dividing the ridges of the same order yields the transfer coefficients at the corresponding frequencies. The transfer coefficient signals are then smoothed to eliminate interference. Finally, considering flight parameter conditions such as torque and rotor pitch, a library of transfer coefficients under real-world conditions is constructed. By linking the helicopter flight parameters, the transmission coefficient is connected with the actual operating conditions of the helicopter, making the calibration of the transmission coefficient more accurate.

[0083] Specifically, different helicopter operating conditions include ground slow speed, air slow speed, hovering, level flight, climb, turning, and dive; signal analysis methods with high time-frequency resolution include synchronous compressed wavelet transform method and parameterized time-frequency analysis method.

[0084] Preferably, step S3 specifically includes the following steps:

[0085] S31. Perform synchronous compressed wavelet transform on the vibration acceleration signals in the three directions of the collected triaxial vibration acceleration sensor, extract the relevant fundamental frequency and its harmonic ridge of the measured axis, eliminate noise and interference, and retain transient characteristic information;

[0086] S32. Using helicopter flight parameter signals, obtain flight parameter information at any time in the synchronous compressed wavelet transform time-frequency matrix, and then correlate the transfer coefficients of the corresponding fundamental frequency and its harmonic amplitude in the transfer coefficient library. The relevant displacement frequency and its harmonic amplitude information at point S, the test end of the eddy current displacement sensor, are obtained, and the displacement time-frequency matrix at point S, the test end of the eddy current displacement sensor, is obtained:

[0087] (2);

[0088] in, f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer. , , representing the time-frequency matrix in three directions; The amplitude of the time-frequency ridge line extracted from the synchronous compression transformation of the signal; for Synchronous compressed wavelet transform, ;

[0089] S33. Perform synchronous compressed wavelet inverse transform on the displacement time-frequency signal at point S of the eddy current displacement sensor test end to obtain the triaxial displacement time-domain signal at point S of the eddy current displacement sensor test end as the triaxial displacement signal of the eddy current displacement sensor itself:

[0090] (3);

[0091] in, , This represents the time-domain displacement signal at point S of the sensor in three directions. This is for the calculation of synchronous compression inverse transform.

[0092] This embodiment provides a specific process for acquiring the three-dimensional displacement of an eddy current sensor based on its transfer coefficient. During helicopter maneuvers, the acceleration signal contains significant noise and interference from other vibration sources, and this signal is typically non-stationary. Extracting effective information for subsequent displacement correction is crucial. Traditional displacement signal conversion methods based on acceleration integration are easily affected by noise and interference, and cannot solve the problem of large integration errors for stationary signals. This embodiment employs an indirect method, using the three-dimensional acceleration signal at the support, combined with the transfer coefficient associated with the helicopter's operating conditions, to acquire the vibration displacement of the eddy current sensor at point S. The proposed method combines the concept of the transfer coefficient in vibration with signal processing, fully considering the physical transmission characteristics of the helicopter mounting bracket vibration. Since the transfer coefficient can be calibrated and adjusted according to the corresponding helicopter model, measurement point location, and operating conditions, this method has a certain degree of versatility and flexibility. By employing high-precision time-frequency analysis to extract the fundamental and harmonic information of the measured shaft, noise and interference in complex airborne testing environments can be effectively reduced. Furthermore, since this method does not rely on acceleration signal integration to acquire displacement, it is more suitable for processing non-stationary acceleration signals. In summary, the method proposed in this embodiment can extract effective information for displacement correction more reliably.

[0093] Preferably, step S4 specifically includes the following steps:

[0094] S41. Consider the displacement correction in the z-direction of the eddy current displacement sensor itself: by Figure 4It is known that, since the drive shaft is cylindrical, the movement of the displacement sensor itself in the z-direction causes a dynamic change in the gap between the displacement sensor probe and the measured drive shaft, thus affecting the measured displacement signal. Let the radius of the drive shaft be R; under static conditions, the initial displacement between the sensor and the drive shaft, i.e., the static gap, is r, or BC; the change in gap between the sensor probe and the measured drive shaft caused by the sensor's movement in the z-direction is EF. The change in gap between the eddy current displacement sensor probe and the measured drive shaft can be calculated based on the displacement of the eddy current displacement sensor itself in the z-direction. :

[0095] (4);

[0096] in, R The radius of the drive shaft. θ The angle formed by the z-direction movement of the eddy current displacement sensor itself:

[0097] (5);

[0098] S42. Consider the displacement correction in the x-direction of the eddy current displacement sensor itself: by Figure 2 It can be seen that the x-axis motion of the eddy current displacement sensor itself and the collected eddy current displacement sensor vibration displacement signal X(t) are on the same axis. Therefore, the collected eddy current displacement sensor vibration displacement signal X(t) is directly subtracted from the eddy current displacement sensor's own x-axis three-dimensional displacement signal. ;

[0099] S43. Consider the displacement correction in the y-direction of the eddy current displacement sensor itself: by Figure 2 It can be seen that when the eddy current displacement sensor itself moves in the y direction, it is equivalent to the sensor displacement probe moving parallel to the transmission shaft, directly ignoring the influence of the y-direction movement of the displacement sensor itself on the collected vibration displacement signal of the eddy current displacement sensor.

[0100] S44. The true displacement of the transmission shaft is obtained by correcting the x-axis and z-axis displacements of the eddy current displacement sensor itself and the change in the gap δ between the eddy current displacement sensor probe and the transmission shaft being measured.

[0101] This embodiment provides a displacement correction process based on high-precision time-frequency ridge amplitude extraction. This embodiment utilizes the triaxial displacement signal of the eddy current displacement sensor itself obtained in the aforementioned steps. For displacement test signals The correction process takes into account the dimensions of the tested drive shaft itself and the influence of its initial installation position, rather than simply superimposing vectors.

[0102] Preferably, step S44 includes the following steps:

[0103] S441. Obtain the corrected true displacement of the drive shaft based on the x- and z-direction displacements of the eddy current displacement sensor itself. for:

[0104] (6).

[0105] In this embodiment, time-domain signals are used for correction. The displacement sensor’s own x-axis and z-axis movements will cause changes in the transmission shaft displacement test signal. By combining formulas (1) to (3), the corrected true displacement of the transmission shaft can be obtained.

[0106] Preferably, step S44 includes the following steps:

[0107] S441. Obtain the corrected displacement synchronous compressed wavelet transform time-frequency matrix through synchronous compressed wavelet transform and ridge amplitude extraction. :

[0108] (7);

[0109] in, The time-frequency ridge amplitude is extracted from the vibration displacement signal X(t) acquired by the eddy current displacement sensor through synchronous compressed wavelet transform. f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer;

[0110] S442, to Perform synchronous compressed wavelet inverse transform to obtain the corrected true displacement of the drive shaft. :

[0111] (8);

[0112] in, This is for synchronous compression inverse transform calculation.

[0113] Since X(t) contains its vibration source signal and interference, although the traditional time-domain synchronous averaging can effectively remove the influence of white noise and other vibration source responses, it requires averaging a large amount of data, resulting in low computational efficiency and inevitably losing the transient information of the measured shaft. It cannot adapt to time-varying working conditions and cannot track the characteristic change process of displacement signal. In order to achieve accurate correction of different frequency components and different times, and improve accuracy and reliability, this embodiment considers the corresponding rotation frequency and its harmonics of the measured shaft and eliminates the influence of other vibration components. The traditional time-domain correction and time-frequency correction based on short-time Fourier transform cannot meet the requirements. Therefore, this embodiment adopts a correction method based on high-precision time-frequency analysis methods such as synchronous compression transform and ridge amplitude extraction. Formula (7) replaces the time-domain signal in formula (6) with a time-frequency signal, thereby realizing correction in the time-frequency domain, avoiding the loss of transient information of the measured shaft, adapting to time-varying working conditions, and tracking the characteristic change process of displacement signal. The correction accuracy using time-frequency signal is higher than that using time-domain signal.

[0114] like Figure 5 As shown, this application also provides a helicopter drive shaft displacement testing device under airborne conditions, including:

[0115] The data acquisition module is used to synchronously acquire vibration displacement signals from the eddy current displacement sensor, vibration acceleration signals in three directions from the triaxial vibration acceleration sensor at the eddy current displacement sensor bracket, and helicopter flight parameter signals during the operation of the helicopter power system.

[0116] The transfer coefficient library construction module is used to establish the transfer coefficient between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor of the eddy current displacement sensor bracket. By associating with helicopter flight parameters, the transfer coefficient is linked with the actual working conditions of the helicopter to build a transfer coefficient library under actual working conditions.

[0117] The triaxial displacement signal calculation module is used to obtain the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor based on the transfer coefficient library under real working conditions, and use it as the triaxial displacement signal of the eddy current displacement sensor itself.

[0118] The displacement correction module is used to correct the vibration displacement signal of the eddy current displacement sensor by combining the size of the transmission shaft under test, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor itself, so as to obtain the corrected true displacement of the transmission shaft.

[0119] This application provides a helicopter drive shaft displacement testing device under airborne conditions, employing the helicopter drive shaft displacement testing method under airborne conditions described in the above embodiments, thus solving the technical problem of low accuracy in existing helicopter drive shaft displacement testing results under airborne conditions. Compared with the prior art, the beneficial effects of the helicopter drive shaft displacement testing device under airborne conditions provided in this application are the same as those of the helicopter drive shaft displacement testing method under airborne conditions provided in the above embodiments, and other technical features of the helicopter drive shaft displacement testing device under airborne conditions are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0120] like Figure 6 As shown, a preferred embodiment of this application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the helicopter drive shaft displacement testing method in the airborne environment described in the above embodiments.

[0121] The application provides an electronic device that employs the helicopter drive shaft displacement testing method under airborne conditions described in the above embodiments, thereby addressing the technical problem of low accuracy in existing helicopter drive shaft displacement testing results under airborne conditions. Compared with the prior art, the beneficial effects of the electronic device provided in this application are the same as those of the helicopter drive shaft displacement testing method under airborne conditions provided in the above embodiments, and other technical features of the electronic device are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0122] like Figure 7 As shown, a preferred embodiment of this application also provides a computer device, which may be a terminal or a liveness detection server, and its internal structure diagram may be as follows. Figure 7 As shown, the computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface is used to communicate with other external computer devices via a network connection. When the computer program is executed by the processor, it implements the steps of the helicopter drive shaft displacement testing method described above under airborne conditions.

[0123] Those skilled in the art will understand that Figure 7The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0124] The computer equipment provided in this application employs the helicopter drive shaft displacement testing method under airborne conditions described in the above embodiments, thereby solving the technical problem of low accuracy in existing helicopter drive shaft displacement testing results under airborne conditions. Compared with the prior art, the beneficial effects of the computer equipment provided in this application are the same as those of the helicopter drive shaft displacement testing method under airborne conditions provided in the above embodiments, and other technical features of the electronic equipment are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0125] A preferred embodiment of this application also provides a storage medium, the storage medium including a stored program, which, when the program is executed, controls the device where the storage medium is located to perform the steps of the helicopter drive shaft displacement testing method in the airborne environment described in the above embodiments.

[0126] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0127] If the functions described in this embodiment are implemented as software functional units and sold or used as independent products, they can be stored in one or more computing device-readable storage media. Based on this understanding, the parts of this application's embodiments that contribute to the prior art or the technical solutions can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a computing device (which may be a personal computer, server, mobile computing device, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage media include: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0128] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented in various computer languages, such as the object-oriented programming language C++ and the embedded programming language C.

[0129] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0130] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0131] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0132] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the helicopter drive shaft displacement testing method under airborne conditions as described above.

[0133] The computer program product provided in this application can solve the technical problems of existing methods for testing helicopter drive shaft displacement in airborne environments being complex, difficult to implement, computationally intensive, and requiring high computing power. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the helicopter drive shaft displacement testing method in airborne environments provided in the above embodiments, and will not be repeated here.

[0134] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0135] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for testing the displacement of a helicopter drive shaft under airborne conditions, characterized in that, Including the following steps: S1. During the operation of the helicopter power system, the vibration displacement signal of the eddy current displacement sensor, the vibration acceleration signal in three directions of the triaxial vibration acceleration sensor at the support of the eddy current displacement sensor, and the helicopter flight parameter signal are collected synchronously. S2. Establish the transfer coefficient between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor on the eddy current displacement sensor bracket. By associating with helicopter flight parameters, link the transfer coefficient with the actual operating conditions of the helicopter, and construct a transfer coefficient library under actual operating conditions. The specific steps include: S21. During the helicopter ground test, a triaxial displacement test is performed at point S on the eddy current displacement sensor test end, and a triaxial acceleration test is performed at point A on the eddy current displacement sensor support. The transfer coefficient matrix H from point A to point S is obtained. Different helicopter operating conditions are simulated, and a preliminary library of transfer coefficients under different operating conditions is established. The transmission coefficient H SA for: ； Where: each element in the matrix Indicates from the input port Directional physical quantity to output port Transmission coefficient of directional physical quantities ; S22. Under the actual working conditions of the helicopter power system, the triaxial acceleration signal of the eddy current displacement sensor bracket, the triaxial displacement signal at point S of the eddy current displacement sensor test end, and the helicopter flight parameter signal are synchronously collected. S23. Data processing is performed using a signal analysis method with high time-frequency resolution, followed by time-frequency filtering to eliminate interference and noise, extract the amplitude of the main order time-frequency ridges of the measured transmission shaft under real working conditions, and accurately capture transient characteristics. S24. Divide the time-frequency ridges of the same order to obtain the transfer coefficient at the corresponding frequency, and smooth the transfer coefficient to eliminate interference. S25. Correlate the transfer coefficients with the helicopter flight parameter signals, link the transfer coefficients with the actual operating conditions of the helicopter, and construct a transfer coefficient library under the actual operating conditions. S3. Based on the transfer coefficient library under real working conditions, the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor is obtained as the triaxial displacement signal of the eddy current displacement sensor itself. S4. Combine the dimensions of the tested drive shaft itself, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor to correct the vibration displacement signal of the eddy current displacement sensor, and obtain the corrected true displacement of the drive shaft.

2. The method for testing the displacement of a helicopter drive shaft in an airborne environment according to claim 1, characterized in that, Different helicopter operating conditions include ground slow speed, air slow speed, hovering, level flight, climb, turn, and dive; signal analysis methods with high time-frequency resolution include synchronous compressed wavelet transform method and parameterized time-frequency analysis method.

3. The method for testing helicopter drive shaft displacement under airborne conditions according to claim 2, characterized in that, Step S3 specifically includes the following steps: S31. Perform synchronous compressed wavelet transform on the vibration acceleration signals in the three directions of the collected triaxial vibration acceleration sensor, extract the relevant fundamental frequency and its harmonic ridge of the measured axis, eliminate noise and interference, and retain transient characteristic information; S32. Using helicopter flight parameter signals, obtain flight parameter information at any time in the synchronous compressed wavelet transform time-frequency matrix, and then correlate the transfer coefficients of the corresponding fundamental frequency and its harmonic amplitude in the transfer coefficient library. The relevant displacement frequency and its harmonic amplitude information at point S, the test end of the eddy current displacement sensor, are obtained, and the displacement time-frequency matrix at point S, the test end of the eddy current displacement sensor, is obtained: ； in, f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer; , , representing the time-frequency matrix in three directions; The amplitude of the time-frequency ridge line extracted from the synchronous compression transformation of the signal; for Synchronous compressed wavelet transform, ; S33. Perform synchronous compressed wavelet inverse transform on the displacement time-frequency signal at point S of the eddy current displacement sensor test end to obtain the triaxial displacement time-domain signal at point S of the eddy current displacement sensor test end as the triaxial displacement signal of the eddy current displacement sensor itself: ； in, , This represents the time-domain displacement signal in three directions at point S, the test end of the eddy current displacement sensor. This is for the calculation of synchronous compression inverse transform.

4. The method for testing the displacement of a helicopter drive shaft in an airborne environment according to claim 3, characterized in that, Step S4 specifically includes the following steps: S41. Consider the displacement correction in the z-direction of the eddy current displacement sensor itself: Calculate the change in gap between the eddy current displacement sensor probe and the measured transmission shaft based on the displacement in the z-direction of the eddy current displacement sensor itself. : ； in, R The radius of the drive shaft. θ The angle formed by the z-direction movement of the eddy current displacement sensor itself: ； S42. Considering the displacement correction in the x-direction of the eddy current displacement sensor itself: The x-direction motion of the eddy current displacement sensor itself and the collected eddy current displacement sensor vibration displacement signal X(t) are on the same axis. The collected eddy current displacement sensor vibration displacement signal X(t) is directly subtracted from the eddy current displacement sensor's own x-axis three-dimensional displacement signal. ; S43. Consider the displacement correction in the y-direction of the eddy current displacement sensor itself: When the eddy current displacement sensor itself moves in the y-direction, it is equivalent to the sensor displacement probe moving parallel to the transmission shaft, directly ignoring the influence of the y-direction movement of the displacement sensor itself on the collected vibration displacement signal of the eddy current displacement sensor. S44. The true displacement of the transmission shaft is obtained by correcting the x-axis and z-axis displacements of the eddy current displacement sensor itself and the change in the gap δ between the eddy current displacement sensor probe and the transmission shaft being measured.

5. The method for testing the displacement of a helicopter drive shaft in an airborne environment according to claim 4, characterized in that, Step S44 includes the following steps: S441. Obtain the corrected true displacement of the drive shaft based on the x- and z-direction displacements of the eddy current displacement sensor itself. for: 。 6. The method for testing the displacement of a helicopter drive shaft in an airborne environment according to claim 5, characterized in that, Step S44 includes the following steps: S441. Obtain the corrected displacement synchronous compressed wavelet transform time-frequency matrix through synchronous compressed wavelet transform and ridge amplitude extraction. : ； in, Vibration displacement signal acquired by eddy current displacement sensor The time-frequency ridge amplitude extracted by synchronous compressed wavelet transform. f = kf r , f r The measured transmission shaft rotational frequency k It is a positive integer; S442, to Perform a synchronous compressed wavelet transform inverse to obtain the corrected true displacement of the drive shaft. : ； in, This is for the calculation of synchronous compression inverse transform.

7. A helicopter drive shaft displacement testing device under airborne conditions, characterized in that, include: The data acquisition module is used to synchronously acquire vibration displacement signals from the eddy current displacement sensor, vibration acceleration signals in three directions from the triaxial vibration acceleration sensor at the eddy current displacement sensor bracket, and helicopter flight parameter signals during the operation of the helicopter power system. The transfer coefficient library construction module is used to establish the transfer coefficients between point S of the eddy current displacement sensor test end and point A of the triaxial vibration acceleration sensor on the eddy current displacement sensor bracket. By associating with helicopter flight parameters, the transfer coefficients are linked to the actual operating conditions of the helicopter, thus constructing a transfer coefficient library under real operating conditions. Specifically, it is used for: During the helicopter ground test, triaxial displacement tests were performed at point S on the eddy current displacement sensor test end, and triaxial acceleration tests were performed at point A on the eddy current displacement sensor support. The transfer coefficient matrix H from point A to point S was obtained. Different helicopter operating conditions were simulated, and a preliminary library of transfer coefficients under different operating conditions was established. The transmission coefficient H SA for: ； Where: each element in the matrix Indicates from the input port Directional physical quantity to output port Transmission coefficient of directional physical quantities ; Under the actual working conditions of the helicopter power system, the triaxial acceleration signal of the eddy current displacement sensor bracket, the triaxial displacement signal at point S of the eddy current displacement sensor test end, and the helicopter flight parameter signal are collected synchronously. Data processing is performed using a signal analysis method with high time-frequency resolution, followed by time-frequency filtering to eliminate interference and noise, and the amplitude of the main order time-frequency ridges of the tested drive shaft under real working conditions is extracted to accurately capture transient characteristics. Divide the time-frequency ridges of the same order to obtain the transfer coefficient at the corresponding frequency, and smooth the transfer coefficient to eliminate interference; The transfer coefficients are correlated with helicopter flight parameter signals, and the transfer coefficients are linked to the actual operating conditions of the helicopter to build a library of transfer coefficients under actual operating conditions. The triaxial displacement signal calculation module is used to obtain the triaxial displacement time domain signal at point S of the test end of the eddy current displacement sensor based on the transfer coefficient library under real working conditions, and use it as the triaxial displacement signal of the eddy current displacement sensor itself. The displacement correction module is used to correct the vibration displacement signal of the eddy current displacement sensor by combining the size of the transmission shaft under test, the initial installation position, and the three-dimensional displacement signal of the eddy current displacement sensor itself, so as to obtain the corrected true displacement of the transmission shaft.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the helicopter drive shaft displacement testing method under airborne environment as described in any one of claims 1 to 6.

9. A storage medium comprising a stored program, characterized in that, When the program is running, it controls the device containing the storage medium to perform the steps of the helicopter drive shaft displacement test method in an airborne environment as described in any one of claims 1 to 6.

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