A method and device for reducing aircraft vibration, an electronic device, and a storage medium

Abstract

The present disclosure relates to a method and device for reducing aircraft vibration, an electronic device, and a storage medium. The aircraft vibration reduction method includes: when the aircraft is in a mode conversion stage, acquiring flight data signals collected by sensors of the aircraft within a historical preset time period; determining a signal to be attenuated from the flight data signals that have undergone time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude and the center frequency is within a predetermined range; determining adjustment parameters of a structural notch filter according to the signal to be attenuated; after the structural notch filter is adjusted according to the adjustment parameters, using the structural notch filter to filter a control command signal. The above process realizes the reduction of the aircraft amplitude with a relatively small control cost through the identification of the signal to be attenuated and the adjustment of the parameters of the structural notch filter, effectively reducing the potential risks caused by aircraft vibration, protecting the airframe structure and systems of the aircraft, and thus improving the robustness of the aircraft vibration reduction process.

Description

Technical Field

[0001] The present disclosure relates to the field of aviation, and in particular, to a method and device for reducing aircraft vibration, an electronic device, and a storage medium. Background Art

[0002] The flight profile of a compound electric vertical takeoff and landing aircraft (eVTOL) includes: a multi-rotor mode (takeoff and landing phase), mode conversion, and a fixed-wing mode (cruise phase). Generally, the vibration characteristics of the multi-rotor mode can be tested by means such as ground single-propeller bench tests, multi-propeller bench tests, and takeoff and landing tests with protection measures, and the testing methods are relatively mature with relatively low safety risks; the vibration modes of the fixed-wing mode can be obtained through ground vibration tests (GVT), frequency response tests, etc. in the early stage. Therefore, when the compound electric vertical takeoff and landing aircraft is in the multi-rotor mode and the fixed-wing mode, the aircraft vibration characteristics can be obtained offline, and vibration suppression can be achieved by adding notch filters to the control law.

[0003] However, during the mode conversion stage, both the multi-rotor and fixed-wing control surfaces are involved in control. Due to the strong cross-coupling and non-linear characteristics of the airflow between multiple control surfaces, it is very difficult for a ground platform to verify the compound electric vertical takeoff and landing aircraft during the mode conversion stage, which brings great difficulties to suppressing the vibration of the compound electric vertical takeoff and landing aircraft during the mode conversion stage. Summary of the Invention

[0004] In view of this, the present disclosure proposes a technical solution for reducing aircraft vibration.

[0005] According to one aspect of the present disclosure, there is provided a method for reducing aircraft vibration, including: when the aircraft is in the mode conversion stage, acquiring the flight data signal collected by the sensor of the aircraft within a historical preset time period; determining a signal to be attenuated from the flight data signal after time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range; determining adjustment parameters of a structural notch filter according to the signal to be attenuated; determining adjustment parameters of a structural notch filter according to the signal to be attenuated; after the structural notch filter is adjusted according to the adjustment parameters, using the structural notch filter to filter the control command signal.

[0006] In a possible implementation, before determining the adjustment parameters of the structural notch filter according to the signal to be attenuated, the method includes: determining the correlation coefficient between the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; the determining the adjustment parameters of the structural notch filter according to the signal to be attenuated includes: in the case where the correlation coefficient is greater than the correlation coefficient threshold, determining the adjustment parameters of the structural notch filter according to the signal to be attenuated.

[0007] In a possible implementation, the determining the correlation coefficient between the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation includes: obtaining the first auto-power spectral density corresponding to the flight data signal, the second auto-power spectral density corresponding to the control command signal, and the cross-power spectral density between the control command signal and the flight data signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; determining the correlation coefficient between the flight data signal and the control command signal according to the first auto-power spectral density, the second auto-power spectral density, and the cross-power spectral density.

[0008] In a possible implementation, the determining the adjustment parameters of the structural notch filter according to the signal to be attenuated includes: determining the transfer function of the structural notch filter, where the transfer function includes adjustment parameters; obtaining the initial adjustment range of the adjustment parameters; determining the parameter adjustment range of the adjustment parameters from the initial adjustment range according to the design requirements of the aircraft; determining the adjustment parameters from the parameter adjustment range according to the signal to be attenuated.

[0009] In a possible implementation, the adjustment parameters of the structural notch filter include the notch frequency, the molecular damping ratio, and the denominator damping ratio; the determining the adjustment parameters from the parameter adjustment range according to the signal to be attenuated includes: determining the notch frequency according to the vibration center frequency of the signal to be attenuated; obtaining the optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated; determining the molecular damping ratio and the denominator damping ratio from the parameter adjustment range according to the notch frequency, the optimization target, and the transfer function.

[0010] In a possible implementation, the obtaining of the flight data signals collected by the sensors of the aircraft within a historical preset time period includes: obtaining the flight data signals of the aircraft in the previous period according to a preset period; the determining of the signal to be attenuated from the flight data signals that have undergone time-frequency transformation includes: determining the signal to be attenuated according to the flight data signals in the previous period; the determining of the adjustment parameters of the structural notch filter according to the signal to be attenuated includes: in the next period, determining the adjustment parameters of the structural notch filter according to the signal to be attenuated.

[0011] In a possible implementation, before the obtaining of the flight data signals collected by the sensors of the aircraft within a historical preset time period, the method includes: superimposing a sweep excitation and / or a stepped maneuver of a longitudinal time series on the control command.

[0012] According to another aspect of the present disclosure, there is provided an aircraft vibration mitigation device, including: a flight data signal acquisition module, configured to obtain the flight data signals collected by the sensors of the aircraft within a historical preset time period when the aircraft is in a mode conversion stage; a signal to be attenuated determination module, configured to determine a signal to be attenuated from the flight data signals that have undergone time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range; an adjustment parameter determination module, configured to determine the adjustment parameters of the structural notch filter according to the signal to be attenuated; and a filtering module, configured to use the structural notch filter to filter the control command signal after the structural notch filter is adjusted according to the adjustment parameters.

[0013] In a possible implementation, the device includes: a correlation coefficient determination module, configured to determine the correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; the adjustment parameter determination module includes: an adjustment parameter determination sub-module, configured to determine the adjustment parameters of the structural notch filter according to the signal to be attenuated when the correlation coefficient is greater than a correlation coefficient threshold.

[0014] In a possible implementation, the correlation coefficient determination module includes: a power spectral density determination sub-module, configured to obtain the first auto-power spectral density corresponding to the flight data signal, the second auto-power spectral density corresponding to the control command signal, and the cross-power spectral density between the control command signal and the flight data signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; a correlation coefficient determination sub-module, configured to determine the correlation coefficient between the flight data signal and the control command signal according to the first auto-power spectral density, the second auto-power spectral density, and the cross-power spectral density.

[0015] In a possible implementation, the adjustment parameter determination sub-module is configured to: determine the transfer function of the structural notch filter, where the transfer function includes adjustment parameters; obtain the initial adjustment range of the adjustment parameters; determine the parameter adjustment range of the adjustment parameters from the initial adjustment range according to the design requirements of the aircraft; and determine the adjustment parameters from the parameter adjustment range according to the signal to be attenuated.

[0016] In a possible implementation, the adjustment parameters of the structural notch filter include the notch frequency, the molecular damping ratio, and the denominator damping ratio; the determining the adjustment parameters from the parameter adjustment range according to the signal to be attenuated includes: determining the notch frequency according to the vibration center frequency of the signal to be attenuated; obtaining the optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated; and determining the molecular damping ratio and the denominator damping ratio from the parameter adjustment range according to the notch frequency, the optimization target, and the transfer function.

[0017] In a possible implementation, the flight data signal acquisition module includes: a flight data signal period acquisition sub-module configured to acquire the flight data signal of the aircraft in the previous period according to a preset period; the signal to be attenuated determination module includes: a signal to be attenuated determination period sub-module configured to determine the signal to be attenuated according to the flight data signal in the previous period; and the adjustment parameter determination module includes: an adjustment parameter determination period sub-module configured to determine the adjustment parameters of the structural notch filter according to the signal to be attenuated in the next period.

[0018] In a possible implementation, the device includes: a scan excitation superposition module configured to superpose a scan excitation and / or a step manipulation of a longitudinal time series on the control command before acquiring the flight data signal collected by the sensor of the aircraft in a historical preset time period.

[0019] According to another aspect of the present disclosure, there is provided an electronic device, including: a processor; a memory for storing instructions executable by the processor; wherein, the processor is configured to implement the above method when executing the instructions stored in the memory.

[0020] According to another aspect of the present disclosure, there is provided a non-volatile computer-readable storage medium, on which computer program instructions are stored, where the computer program instructions implement the above method when executed by a processor.

[0021] According to another aspect of the present disclosure, there is provided a computer program product including computer-readable code or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0022] In an embodiment of the present disclosure, according to flight data signals collected by sensors within a historical preset time period during the mode conversion stage of an aircraft, a to-be-attenuated signal that causes vibration of the aircraft is determined from the flight data signals after time-frequency transformation. And based on this to-be-attenuated signal, adjustment parameters of a structural notch filter for filtering control instructions are determined, so as to reduce the amplitude of the to-be-attenuated signal that causes vibration of the aircraft in the flight data through the structural notch filter, thereby reducing the amplitude of the aircraft vibration. This process overcomes the difficulty of being unable to obtain the vibration characteristics of the aircraft during the mode conversion stage through ground experiments or data analysis. Compared with the traditional method of improving the structural stiffness of the aircraft, the present disclosure realizes the reduction of the amplitude of the aircraft through the identification of the to-be-attenuated signal and the adjustment of the parameters of the structural notch filter with a relatively small control cost, effectively reducing the potential risks caused by the vibration of the aircraft, protecting the airframe structure and systems of the aircraft, and thus improving the robustness of the aircraft vibration mitigation process.

[0023] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and do not limit the present disclosure.

[0024] Other features and aspects of the present disclosure will become clear based on the following detailed description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings included in and constituting a part of this specification, together with the specification, illustrate exemplary embodiments, features, and aspects of the present disclosure and are used to explain the principles of the present disclosure.

[0026] Figure 1 Show a general layout diagram of a compound electric vertical takeoff and landing aircraft according to an embodiment of the present disclosure.

[0027] Figure 2 Show a flowchart of a method for mitigating aircraft vibration according to an embodiment of the present disclosure.

[0028] Figure 3 Show a flowchart for offline evaluation of the parameter range of a structural notch filter according to an embodiment of the present disclosure.

[0029] Figure 4 Show a flowchart according to an application example of the present disclosure.

[0030] Figure 5Shows an application schematic diagram of an aircraft vibration reduction device according to an embodiment of the present disclosure.

[0031] Figure 6 Shows a block diagram of an aircraft vibration reduction device according to an embodiment of the present disclosure.

[0032] Figure 7 Shows a block diagram of an electronic device according to an embodiment of the present disclosure.

[0033] Figure 8 Shows a block diagram of an electronic device according to an embodiment of the present disclosure. Detailed implementation manners

[0034] The following will describe various exemplary embodiments, features, and aspects of the present disclosure in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0035] The special term "exemplary" herein means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" herein does not have to be construed as superior to or better than other embodiments.

[0036] The term "and / or" in this article is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" in this article means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C can represent any one or more elements selected from the set composed of A, B, and C.

[0037] In addition, for a better description of the present disclosure, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present disclosure can also be implemented without some specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present disclosure.

[0038] The control configuration of a compound electric vertical takeoff and landing aircraft includes: lift propellers of a multi-rotor for vertical takeoff and landing, fixed-wing control surfaces for high-speed flight, and thrust propellers for generating forward thrust. The compound electric vertical takeoff and landing aircraft can not only take off and land vertically, but also cruise at high speed, combining the advantages of multi-rotor aircraft and fixed-wing aircraft.

[0039] A typical overall layout of a compound electric vertical takeoff and landing aircraft is as Figure 1 shown. As Figure 1As shown in the figure, the compound electric vertical takeoff and landing aircraft includes: a flight control computer, lift propellers, motor controllers for the lift propellers, motor controllers for the tail thrust propellers, tail thrust propellers, etc. Among them, the flight control computer is used to receive the pilot's operation instructions and data on the aircraft attitude, angular rate and other state information collected by sensors, and through control law calculation, output flight control instructions to control the rotation speed and rudder deflection of the propellers (including lift propellers and tail thrust propellers) in real time; the lift propellers are used for aircraft control in the multi-rotor and conversion stages; the motor controllers for the lift propellers are used to receive the lift propeller rotation speed instructions output by the flight control computer, and through motor controller calculation, output AC voltage signals to control the motors, thereby instructing the lift propellers to rotate; the motor controllers for the tail thrust propellers are used to receive the tail thrust propeller rotation speed instructions output by the flight control computer, and through motor controller calculation, output AC voltage signals to control the motors, thereby instructing the tail thrust propellers to rotate; the tail thrust propellers are used to receive the tail thrust propeller rotation speed instructions output by the flight control computer, and the motors drive the tail thrust propellers to rotate, generating thrust to make the aircraft move forward.

[0040] The flight profile of the compound electric vertical takeoff and landing aircraft includes: multi-rotor mode (takeoff and landing stage), mode conversion, and fixed-wing mode (cruise stage). During the mode conversion stage of the aircraft, after receiving the control instructions issued by the aircraft, the propellers and control rudders act simultaneously to complete the desired operation instructions. Among them, the lift propellers generate lift by controlling the rotation speed of the rotors, and the oncoming flow direction is perpendicular to the propeller plane; the wings are affected by the oncoming flow in the forward direction, and lift is generated due to the pressure difference, and the oncoming flow direction is the same as the aircraft speed direction. Since the oncoming flow directions for the lift propellers and the wings to generate lift cross, it will cause aerodynamic interference, resulting in the vibration of the aircraft in unsteady airflow. The vibration of the aircraft is sensed by sensors and enters the control loop, forming the coupling of aerodynamics-structure-control. This coupling of aerodynamics-structure-control formed by the aircraft vibration is the main factor affecting the aircraft speed, flight safety, etc. At present, since the vibration characteristics of the aircraft during the conversion flight stage cannot be obtained through ground tests or data analysis, it has brought difficulties to the solution of the problem of reducing the vibration of the aircraft during the mode conversion stage.

[0041] Figure 2 The flowchart of the aircraft vibration mitigation method according to an embodiment of the present disclosure is shown. This method can be applied to the aircraft vibration mitigation device. The aircraft vibration mitigation device can be a terminal device, a server, or other processing devices, etc. In one example, the aircraft vibration mitigation device can be set in the flight control computer. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc.

[0042] In some possible implementation manners, the aircraft vibration mitigation method can be implemented by a processor invoking computer-readable instructions stored in a memory.

[0043] As Figure 2 shown, the aircraft vibration mitigation method may include:

[0044] In step S21, when the aircraft is in a mode conversion stage, flight data signals collected by sensors of the aircraft within a historical preset time period are acquired.

[0045] In step S22, a signal to be attenuated is determined from the flight data signals that have undergone time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range.

[0046] In step S23, adjustment parameters of a structural notch filter are determined according to the signal to be attenuated.

[0047] In step S24, after the structural notch filter is adjusted according to the adjustment parameters, the structural notch filter is used to filter a control command signal.

[0048] Wherein, the mode conversion is a flight mode in which the aircraft switches between a multi-rotor mode (takeoff and landing stage) and a fixed-wing mode (cruise stage). Specifically, it may be that the aircraft switches from the multi-rotor mode to the fixed-wing mode, or from the fixed-wing mode to the multi-rotor mode. The present disclosure does not limit the specific content of the mode conversion, and it can be selected according to actual situations.

[0049] The control command signal is an input signal of a flight control system, and the flight data signal is a controlled state variable of the aircraft under the control of the control command. The control command may have a corresponding relationship with the flight data signal. In one example, when the control command is a pitch attitude control channel, the flight data signal may be pitch angular velocity and normal acceleration.

[0050] When the amplitude of the vibration of a compound electric vertical takeoff and landing aircraft in unsteady airflow reaches a certain level, it will cause damage to the aircraft structure and so on. Therefore, for a compound electric vertical takeoff and landing aircraft, to determine the signal to be attenuated from the flight data signal, the specific implementation method can be as follows: First, perform time-frequency transformation on the flight data signal. When there is a signal in the time-frequency transformed flight data signal whose amplitude exceeds the defined vibration amplitude and the center frequency is within a predetermined range, it is determined that there is a signal to be attenuated in the flight data signal. Among them, the defined vibration amplitude and the predetermined range can be selected according to the actual situation. In one example, the defined vibration amplitude can be 10 times or more of the basic amplitude threshold of the sensor, and the predetermined range can be within 2 to 5 times of the flight control frequency. The basic amplitude threshold of the sensor can be obtained through ground tests or based on the vibration characteristics in the multi-rotor stage. The method of time-frequency transformation can be selected according to the situation. Specifically, the time-frequency transformation can be the fast Fourier transform, Laplace transform, or Z transform, etc. In one example, when using the fast Fourier transform for time-frequency transformation, a weighted window function can be used simultaneously to make the time-domain signal better meet the periodic requirements of FFT processing and reduce spectral leakage. The present disclosure does not make specific limitations on the way of time-frequency transformation and can be selected according to the situation.

[0051] The historical preset time period is the time period before filtering the control command using the structural notch filter. Specifically, the control command of the aircraft in the mode conversion stage can be filtered according to the flight data signal within the historical preset time period. The present disclosure does not make specific limitations on the length of the historical preset time period and can be selected according to the frequency range of the signal to be attenuated. In one example, the length of the historical preset time period is not less than 5 s.

[0052] The structural notch filter can accurately remove the signal interference in a specific narrow frequency band without affecting other useful signal frequency bands. In one example, after determining the signal to be attenuated, the structural notch filter can be used to filter the control command, and by adjusting the parameters of the structural notch filter, the amplitude of the specific signal (i.e., the signal to be attenuated) in the flight data can be reduced.

[0053] In an embodiment of the present disclosure, according to the flight data signals collected by sensors within a historical preset time period during the mode conversion stage of the aircraft, a signal to be attenuated that causes the vibration of the aircraft is determined from the flight data signals after time-frequency transformation. And based on this signal to be attenuated, adjustment parameters of a structural notch filter for filtering the control command are determined, so as to reduce the amplitude of the signal to be attenuated that causes the vibration of the aircraft in the flight data through the structural notch filter, thereby reducing the amplitude of the aircraft vibration. This process overcomes the difficulty of being unable to obtain the vibration characteristics of the aircraft during the mode conversion stage through ground experiments or data analysis. Compared with the traditional method of improving the structural stiffness of the aircraft, the present disclosure realizes the reduction of the amplitude of the aircraft through the identification of the signal to be attenuated and the adjustment of the parameters of the structural notch filter with a relatively small control cost, effectively reducing the potential risks caused by the vibration of the aircraft, protecting the airframe structure and systems of the aircraft, and thus improving the robustness of the aircraft vibration mitigation process.

[0054] When the aircraft vibrates, the spectrum of the flight data signal will definitely change accordingly. As the vibration of the aircraft gradually forms, the phenomenon of high-frequency resonance also appears. Therefore, the high-frequency components of the flight data signal should be very sensitive to the changes in the state of the aircraft. To avoid incorrect correspondence between the control command and the flight data signal, in a possible implementation manner, before determining the adjustment parameters of the structural notch filter according to the signal to be attenuated, the method includes:

[0055] Determine the correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation;

[0056] Determining the adjustment parameters of the structural notch filter according to the signal to be attenuated includes:

[0057] In the case where the correlation coefficient is greater than the correlation coefficient threshold, determine the adjustment parameters of the structural notch filter according to the signal to be attenuated.

[0058] Specifically, the flight data signal can be subjected to empirical mode decomposition (EMD), the first IMF representing the highest frequency component is selected, and time-frequency transformation is performed to obtain its frequency domain signal, and then the correlation coefficient between the frequency domain signal of the flight data signal and the frequency domain signal of the control command signal is calculated. The correlation coefficient represents the correlation between the control command signal and the flight data signal, and its value ranges from 0 to 1. The higher the correlation coefficient, the higher the correlation between the control command signal and the flight data signal, and the higher the reliability of the frequency characteristics in the flight data signal. On the contrary, the lower the correlation coefficient, the lower the correlation between the control command signal and the flight data signal. The present disclosure does not specifically limit the correlation coefficient threshold and the method for obtaining the correlation coefficient, which can be selected according to the actual situation. In one example, the correlation coefficient threshold can be set to 0.8.

[0059] The auto-power spectrum can be used to analyze the power distribution of a time series signal at different frequencies, and the cross-power spectrum can be used to analyze the correlation of the power distributions of two time series signals at different frequencies. In one example, determining the correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation includes: obtaining the first auto-power spectral density corresponding to the flight data signal, the second auto-power spectral density corresponding to the control command signal, and the cross-power spectral density between the control command signal and the flight data signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; determining the correlation coefficient between the flight data signal and the control command signal according to the first auto-power spectral density, the second auto-power spectral density, and the cross-power spectral density.

[0060] In the embodiments of the present disclosure, by calculating the correlation coefficient between the flight data signal and the control command signal in advance, and performing subsequent related operations on the parameter adjustment of the structural notch filter only when the correlation coefficient is greater than the correlation coefficient threshold, it is possible to avoid selecting the wrong correspondence between the flight data signal and the control command, and thus the effect of the parameter adjustment of the structural notch filter on reducing the vibration of the aircraft is small or ineffective.

[0061] In a possible implementation manner, determining the adjustment parameter of the structural notch filter according to the signal to be attenuated includes:

[0062] Determining the transfer function of the structural notch filter, where the transfer function includes adjustment parameters;

[0063] Obtaining the initial adjustment range of the adjustment parameter;

[0064] Determining the parameter adjustment range of the adjustment parameter from the initial adjustment range according to the design requirements of the aircraft;

[0065] Determine an adjustment parameter from the parameter adjustment range according to the signal to be attenuated.

[0066] The transfer function represents the response characteristics of the input to the output at different frequencies in complex form. In one example, the transfer function can be obtained from the auto-power spectrum and cross-power spectrum of the input signal and the output signal, that is, the structure of the structural notch filter is determined. Then, according to the relationship between the transfer function and the adjustment parameter, the adjustment parameter is further solved. In one example, when the time-frequency transformation method is Laplace transformation, the relationship between the transfer function and the adjustment parameter can be as follows:

[0067]

[0068] where G is the transfer function, n is the number of signals to be attenuated, s is the s-domain, ξ num is the numerator damping ratio, ξ den is the denominator damping ratio, and ω is the notch frequency.

[0069] Specifically, the initial adjustment ranges of the three adjustment parameters in the transfer function, namely the numerator damping ratio ξ num , the denominator damping ratio ξ den and the notch frequency ω, can be set as follows:

[0070] The value range of the notch frequency ω can be set as: the minimum is 2 to 5 times the control loop bandwidth, and the maximum does not exceed half of the sampling frequency.

[0071] The value ranges of the numerator damping ratio ξ num and the denominator damping ratio ξ den are set as 0.05 ≤ ξ num ≤ ξ den ≤ 0.7. In one example, the initial values of the numerator damping ratio ξ num and the denominator damping ratio ξ den can be set to be the same. At this time, the transfer function G = 1, and the structural notch filter is a direct connection path.

[0072] After completing the adjustment parameters ξ num1 , ξ den1 , ω1, ξ num2 , ξ den2 , ω2…ξ numn , ξ denn , ω nAfter the initial condition range is determined, since the initial adjustment range is an independent adjustment range for each parameter, directly using the adjustment parameters in the initial adjustment range to determine the parameters of the structural notch filter will increase the amount of calculation. In one possible implementation, the various adjustment parameters can be combined to obtain a specific adjustment range for each parameter that meets the aircraft design requirements. In one example, each parameter can be substituted into a closed-loop simulation environment for analysis and calculation to confirm that the most stringent parameter combination still meets the parameter adjustment range of the adjustment parameter that meets the aircraft design requirements. Specifically, the aircraft design requirements may be acceptable handling quality and stability requirements. The present disclosure does not limit the specific content of the aircraft design requirements and can be set according to actual conditions. Among them, in order to reduce the amount of online analysis data, in one example, the transfer function of the structural notch filter used to suppress vibration and the determination of the parameter adjustment range of the adjustment parameters can be determined by offline analysis.

[0073] In one example, if there is no signal to be attenuated that meets the conditions, a default value is output, for example: ξ num =ξ den =0.7, ω=TBD rad / s. Wherein, TBD is a value to be defined, and the specific value can be determined according to the actual situation.

[0074] Figure 3 The flowchart of the off-line evaluation of the parameter range of the structural notch filter is as follows: the structure of the structural notch filter (i.e., the transfer function) and the preliminary adjustment range of each adjustment parameter in the transfer function are defined; various adjustment parameters are combined, and the adjustment parameters that meet the control loop handling stability are determined from the preliminary adjustment range to determine the parameter adjustment range of each adjustment parameter in the transfer function.

[0075] In the disclosed embodiment, the structure of the structural notch filter is set by the transfer function, and according to the aircraft design requirements, the parameter adjustment range in the transfer function is narrowed from the initial adjustment range to the parameter adjustment range, and finally, the adjustment parameter is determined from the parameter adjustment range according to the signal to be attenuated. This process realizes the setting of the structure of the structural notch filter, reduces the range of each adjustment parameter in the transfer function, reduces the amount of calculation for determining the specific adjustment parameter from the range of each adjustment parameter in the transfer function through the signal to be attenuated, helps to improve the speed of the structural notch filter parameter adjustment, and then realizes the real-time update of the adjustment parameters of the structural notch filter.

[0076] In a possible implementation, the adjustment parameters of the structural notch filter include notch frequency, numerator damping ratio and denominator damping ratio;

[0077] The step of determining the adjustment parameter from the parameter adjustment range according to the signal to be attenuated includes:

[0078] Determine the notch frequency according to the vibration center frequency of the signal to be attenuated.

[0079] Obtain the optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated.

[0080] Determine the molecular damping ratio and the denominator damping ratio from the parameter adjustment range according to the notch frequency, the optimization target, and the transfer function.

[0081] After the transfer function is determined, the adjustment parameters of the structural notch filter are also determined simultaneously. When the adjustment parameters of the structural notch filter include the notch frequency, the molecular damping ratio, and the denominator damping ratio, the specific values of the adjustment parameters can be determined according to the parameter adjustment range. Specifically, the notch frequency can be determined according to the vibration center frequency of the signal to be attenuated, where the vibration center frequency can be obtained by performing a self-power spectrum analysis on the flight data signal after time-frequency conversion. Specifically, the frequency points with high energy density distribution can be extracted from the self-power spectrum of the flight data signal as the vibration center frequency.

[0082] The optimization target is the attenuation amplitude of the signal to be attenuated. Specifically, the attenuation amplitude of the signal to be attenuated can be determined according to the vibration amplitude of the signal to be attenuated and the basic vibration amplitude of the sensor. In one example, the attenuation amplitude of the signal to be attenuated can be set to where A1 is the vibration amplitude identified online, A0 is the basic vibration amplitude of the sensor, and A0 can be obtained through ground tests or the vibration characteristics in the multi-rotor stage.

[0083] When using the structural notch filter to filter the control command, additional delay may be caused due to the introduction of the structural notch filter. In one example, the optimization target may further include the constraint adjustment of the additional delay. Specifically, the additional delay can be set to not exceed 20 ms.

[0084] After the vibration center frequency and the optimization target of the signal to be attenuated are obtained, the molecular damping ratio and the denominator damping ratio can be determined from the parameter adjustment range through the constraint condition of the transfer function. Specifically, the fminsearch function method for finding the minimum value provided by MATLAB can be used to specifically solve the molecular damping ratio and the denominator damping ratio. The present disclosure does not limit the specific solution process of the molecular damping ratio and the denominator damping ratio.

[0085] In the embodiments of the present disclosure, when the adjustment parameters of the structural notch filter are the notch frequency, the molecular damping ratio, and the denominator damping ratio, the specific solution processes of each adjustment parameter are set, so as to determine the adjustment parameters from the parameter adjustment range according to the signal to be attenuated. According to this method, by adjusting the parameters of the structural notch filter with a relatively small control cost, the amplitude of the aircraft is reduced, and thus the potential risks caused by the vibration of the aircraft are effectively reduced, the airframe structure and systems of the aircraft are protected, and the robustness of the aircraft vibration mitigation process is improved.

[0086] In one possible implementation, the obtaining of the flight data signals collected by the sensors of the aircraft within a historical preset time period includes:

[0087] Obtaining the flight data signals of the aircraft in the previous cycle according to a preset period;

[0088] The determining of the signal to be attenuated from the flight data signals after time-frequency transformation includes:

[0089] Determining the signal to be attenuated according to the flight data signals in the previous cycle;

[0090] The determining of the adjustment parameters of the structural notch filter according to the signal to be attenuated includes:

[0091] In the next cycle, determining the adjustment parameters of the structural notch filter according to the signal to be attenuated.

[0092] In the embodiments of the present disclosure, the flight data signals of the aircraft are periodically obtained, the signal to be attenuated is determined according to the flight data signals obtained in the previous cycle, the adjustment parameters of the structural notch filter are determined based on the signal to be attenuated, and the control command signal is filtered by using the structural notch filter with adjusted parameters in the next cycle. This process is carried out in a periodic manner, and according to the flight data signals obtained in real time, the adjustment parameters of the structural notch filter for filtering the control command are continuously adjusted, realizing real-time and stable filtering of the control command and effectively reducing the vibration level of the aircraft.

[0093] When the aircraft is in the mode conversion stage, due to the unstable flight state and limited sensor accuracy, the acquisition of the flight data signals will be affected, resulting in a reduced identification accuracy of the flight data signals, and thus the flight data signals cannot be effectively identified.

[0094] In one possible implementation, before the obtaining of the flight data signals collected by the sensors of the aircraft within a historical preset time period, the method includes:

[0095] Superimposing a sweep excitation and / or a stepped maneuver of a longitudinal time series on the control command.

[0096] Among them, the scanning excitation may be a scanning excitation with a small amplitude, the step manipulation of the longitudinal time series may be applying inputs with different lengths in two directions, and the step manipulation is a manipulation using a set of longitudinal time series for a given aircraft configuration and flight state. Specifically, the step manipulation may be a 3211 manipulation, and the 3211 manipulation may be pulling the stick for 3 s, pushing the stick for 2 s, pulling the stick for 1 s, and pushing the stick for 1 s.

[0097] In the embodiments of the present disclosure, by superimposing a scanning excitation with a small amplitude and / or a step manipulation of a longitudinal time series on the control instruction, the flight data signal has sufficient power spectral density, improving the identification accuracy of the flight data signal, and further improving the accuracy of the determined adjustment parameters.

[0098] Application scenario example

[0099] The flight profile of a compound electric vertical takeoff and landing aircraft includes: a multi-rotor mode (takeoff and landing stage), mode conversion, and a fixed-wing mode (cruise stage). Different from the multi-rotor mode and the fixed-wing mode, when the aircraft is in the mode conversion stage, both the multi-rotor and fixed-wing control surfaces participate in the control. Due to the strong cross-coupling and non-linear characteristics of the airflow between multiple control surfaces, it is very difficult for a ground platform to verify. At the same time, the aircraft will generate an aero-structural-control coupling formed by aircraft vibration during the mode conversion stage, which brings great difficulties to the design of the aircraft controller.

[0100] Figure 4 A flowchart showing an application example according to the present disclosure is shown. As shown in the figure, the embodiments of the present disclosure propose a method for reducing aircraft vibration when the control instruction is the pitch attitude control channel. The process of reducing vibration can be as follows:

[0101] The first step is to confirm the notch filter structure and the adjustment parameter range offline. Through offline analysis, confirm the structure and parameter range of the structural notch filter for vibration suppression. The form of the structural notch filter is: ξ num1 , ξ den1 , ω1, ξ num2 , ξ den2 , ω2…ξ numn , ξ denn , ω n are adjustment parameters. Among them, the value range of the notch frequency ω can be set as: the minimum is 2 to 5 times the control loop bandwidth, and the maximum does not exceed half of the sampling frequency. The numerator damping ratio ξ num and the denominator damping ratio ξ den The value range is set to 0.05 ≤ ξ num ≤ ξ den≤0.7. Substitute the notch frequency, the numerator damping ratio, and the denominator damping ratio into the closed-loop simulation environment for analysis and calculation to obtain the adjustment parameter range. It is necessary to confirm that the most stringent parameter combination still meets the acceptable handling quality and stability requirements of the aircraft during this calculation process.

[0102] Step 2: Calculate the spectral characteristics of the flight data signal in the previous cycle. Perform a fast Fourier transform on the flight data signal in the previous cycle to obtain the signal to be attenuated whose amplitude exceeds the specified vibration amplitude and whose center frequency is within the predetermined range.

[0103] Step 3: Calculate the adjustment parameters of the structural notch filter required to mitigate vibration. Determine the notch frequency based on the vibration center frequency of the signal to be attenuated; obtain the optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated; according to the notch frequency, the optimization target, and the transfer function, use the fminsearch function method for finding the minimum value provided by MATLAB to determine the numerator damping ratio and the denominator damping ratio from the parameter adjustment range.

[0104] Step 4: Update the adjustment parameters of the structural notch filter. Update the adjustment parameters calculated in the previous step.

[0105] Step 5: Update and intercept new real-time data.

[0106] As Figure 5 shown, the present invention provides a schematic diagram of the application of an aircraft vibration mitigation device. As Figure 5 shown, this vibration mitigation device includes three parts:

[0107] a) Spectrum identification module: By online analyzing the spectral characteristics of the actuator control command signal of the basic control law and the flight data signals (including acceleration and acceleration) sensed by the sensors, output the spectral data of the signal to be attenuated whose amplitude exceeds the specified vibration amplitude and whose center frequency is within the predetermined range;

[0108] b) Adjustment parameter calculation module: Design the adjustment parameters of the structural notch filter that meet the requirements based on the vibration mitigation design requirements and the actually sensed spectral characteristics;

[0109] c) Structural notch filter module: Update the parameters output by the adjustment parameter calculation module to achieve the function of online vibration mitigation.

[0110] As Figure 5As shown, during the use of the aircraft vibration mitigation device, the sensor sends the sensed flight data signal to the spectrum recognition module. The spectrum recognition module identifies the signal to be attenuated in the flight data signal. The adjustment parameter calculation module designs the adjustment parameters of the structural notch filter based on the signal to be attenuated. The structural notch filter adjusts its own parameters according to the adjustment parameters, and filters the control command signal (the control command signal is generated by the controller according to the pilot's input manipulation command and simultaneously controls the lift propeller motor and the servo through control allocation) and other data sent by the sensor (such as aircraft attitude, speed, position data, etc.). The filtered control command signal will control the lift propeller motor and the servo to act simultaneously to complete the desired manipulation command. Among them, the spectrum recognition module also calculates the correlation between the control command signal and the flight data signal. The processing method of other data (such as aircraft attitude, speed, position data, etc.) sent by the sensor to the structural filter can be selected according to the actual situation, and the present disclosure does not limit this. Figure 5 The controller shown in can be selected according to the situation. In one example, it can be a Proportion Integration Differentiation (PID) controller.

[0111] In the embodiment of the present disclosure, according to the flight data signal collected by the sensor during the historical preset time period in the mode conversion stage of the aircraft, the signal to be attenuated that causes the aircraft vibration is determined from the flight data signal after time-frequency transformation, and through this signal to be attenuated, the adjustment parameters of the structural notch filter for filtering the control command are determined, so as to reduce the amplitude of the signal to be attenuated that causes the aircraft vibration in the flight data through the structural notch filter, and further reduce the amplitude of the aircraft vibration. This process overcomes the difficulty of not being able to obtain the vibration characteristics of the aircraft in the mode conversion stage through ground experiments or data analysis. Compared with the traditional method of improving the aircraft structure stiffness, the present disclosure realizes the reduction of the aircraft amplitude at a relatively small control cost by identifying the signal to be attenuated and adjusting the parameters of the structural notch filter, effectively reducing the potential risks caused by the aircraft vibration, protecting the aircraft body structure and system, and thus improving the robustness of the aircraft vibration mitigation process.

[0112] It should be noted that the aircraft vibration mitigation method in the embodiment of the present disclosure is not limited to the aircraft vibration mitigation when the above control command is the pitch attitude control channel, and can be applied to any aircraft vibration mitigation, and the present disclosure does not limit this.

[0113] It can be understood that, without violating the principle logic, the above-mentioned various method embodiments mentioned in the present disclosure can be combined with each other to form an embodiment after combination. Due to space limitations, the present disclosure will not elaborate further. Those skilled in the art can understand that in the above methods of the specific implementation manner, the specific execution order of each step should be determined according to its function and possible internal logic.

[0114] In addition, the present disclosure also provides an aircraft vibration mitigation device, an electronic device, a computer-readable storage medium, and a program, all of which can be used to implement any one of the aircraft vibration mitigation methods provided by the present disclosure. The corresponding technical solutions and descriptions can be referred to the corresponding records in the method part and will not be elaborated further.

[0115] Figure 6 The block diagram of the aircraft vibration mitigation device according to an embodiment of the present disclosure is shown. The aircraft vibration mitigation device can be a terminal device, a server, or other processing devices, etc. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc.

[0116] In some possible implementation manners, the aircraft vibration mitigation device can be implemented by a processor calling computer-readable instructions stored in a memory.

[0117] As Figure 6 shown, the aircraft vibration mitigation device 60 may include:

[0118] A flight data signal acquisition module 61, configured to acquire flight data signals collected by sensors of the aircraft within a historical preset time period when the aircraft is in a mode conversion stage;

[0119] A signal to be attenuated determination module 62, configured to determine a signal to be attenuated from the flight data signals after time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range;

[0120] An adjustment parameter determination module 63, configured to determine adjustment parameters of a structural notch filter according to the signal to be attenuated;

[0121] A filtering module 64, configured to filter a control instruction signal using the structural notch filter after the structural notch filter is adjusted according to the adjustment parameters.

[0122] In a possible implementation, the device includes: a correlation coefficient determination module, configured to determine a correlation coefficient between the flight data signal after time-frequency transformation and the control instruction signal after time-frequency transformation; an adjustment parameter determination module, including: an adjustment parameter determination sub-module, configured to determine an adjustment parameter of a structural notch filter according to the signal to be attenuated when the correlation coefficient is greater than a correlation coefficient threshold.

[0123] In a possible implementation, the correlation coefficient determination module includes: a power spectral density determination sub-module, configured to obtain a first auto-power spectral density corresponding to the flight data signal, a second auto-power spectral density corresponding to the control instruction signal, and a cross-power spectral density between the control instruction signal and the flight data signal according to the flight data signal after time-frequency transformation and the control instruction signal after time-frequency transformation; a correlation coefficient determination sub-module, configured to determine a correlation coefficient between the flight data signal and the control instruction signal according to the first auto-power spectral density, the second auto-power spectral density, and the cross-power spectral density.

[0124] In a possible implementation, the adjustment parameter determination sub-module is configured to: determine a transfer function of the structural notch filter, where the transfer function includes adjustment parameters; obtain an initial adjustment range of the adjustment parameters; determine a parameter adjustment range of the adjustment parameters from the initial adjustment range according to the design requirements of the aircraft; and determine the adjustment parameters from the parameter adjustment range according to the signal to be attenuated.

[0125] In a possible implementation, the adjustment parameters of the structural notch filter include a notch frequency, a numerator damping ratio, and a denominator damping ratio; and determining the adjustment parameters from the parameter adjustment range according to the signal to be attenuated includes: determining the notch frequency according to the vibration center frequency of the signal to be attenuated; obtaining an optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated; and determining the numerator damping ratio and the denominator damping ratio from the parameter adjustment range according to the notch frequency, the optimization target, and the transfer function.

[0126] In a possible implementation, the flight data signal acquisition module includes: a flight data signal period acquisition sub-module, configured to acquire the flight data signal of the aircraft in the previous period according to a preset period; the signal to be attenuated determination module includes: a signal to be attenuated determination period sub-module, configured to determine the signal to be attenuated according to the flight data signal in the previous period; and the adjustment parameter determination module includes: an adjustment parameter determination period sub-module, configured to determine the adjustment parameter of the structural notch filter according to the signal to be attenuated in the next period.

[0127] In one possible implementation, the device includes a scanning excitation superposition module, configured to superpose a scanning excitation and / or a stepped manipulation of a longitudinal time series on the control command before acquiring the flight data signals collected by sensors of the aircraft in a historical preset time period.

[0128] The embodiments of the present disclosure also propose a computer-readable storage medium, on which computer program instructions are stored, and when the computer program instructions are executed by a processor, the above method is implemented. The computer-readable storage medium may be a non-volatile computer-readable storage medium.

[0129] The embodiments of the present disclosure also propose an electronic device, including: a processor; a memory for storing instructions executable by the processor; wherein, the processor is configured to call the instructions stored in the memory to execute the above method.

[0130] The embodiments of the present disclosure also provide a computer program product, including computer-readable code, and when the computer-readable code runs on a device, the processor in the device executes instructions for implementing the aircraft vibration mitigation method provided in any one of the above embodiments.

[0131] The embodiments of the present disclosure also provide another computer program product, for storing computer-readable instructions, and when the instructions are executed, the computer executes the operations of the aircraft vibration mitigation method provided in any one of the above embodiments.

[0132] The electronic device may be provided as a terminal, a server or other forms of devices.

[0133] Figure 7 A block diagram of an electronic device 800 according to an embodiment of the present disclosure is shown. For example, the electronic device 800 may be a terminal such as a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0134] Refer to Figure 7 , the electronic device 800 may include one or more of the following components: a processing component 802, a memory 804, a power component 806, a multimedia component 808, an audio component 810, an input / output interface 812, a sensor component 814, and a communication component 816.

[0135] The processing component 802 generally controls the overall operation of the electronic device 800, such as operations associated with display, telephone calls, data communications, camera operations, and recording operations. The processing component 802 may include one or more processors 820 to execute instructions to complete all or part of the steps of the above-described methods. In addition, the processing component 802 may include one or more modules to facilitate the interaction between the processing component 802 and other components. For example, the processing component 802 may include a multimedia module to facilitate the interaction between the multimedia component 808 and the processing component 802.

[0136] The memory 804 is configured to store various types of data to support the operation of the electronic device 800. Examples of such data include instructions for any application or method operating on the electronic device 800, contact data, phone book data, messages, pictures, videos, etc. The memory 804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disks, or optical disks.

[0137] The power component 806 provides power to various components of the electronic device 800. The power component 806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the electronic device 800.

[0138] The multimedia component 808 includes a screen that provides an output interface between the electronic device 800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen can be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensors can not only sense the boundaries of touch or swipe actions, but also detect the duration and pressure associated with the touch or swipe operations. In some embodiments, the multimedia component 808 includes a front camera and / or a rear camera. When the electronic device 800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera can receive external multimedia data. Each of the front camera and the rear camera can be a fixed optical lens system or have focal length and optical zoom capabilities.

[0139] The audio component 810 is configured to output and / or input audio signals. For example, the audio component 810 includes a microphone (MIC) that is configured to receive external audio signals when the electronic device 800 is in an operating mode, such as a call mode, a recording mode, and a voice recognition mode. The received audio signals can be further stored in the memory 804 or transmitted via the communication component 816. In some embodiments, the audio component 810 further includes a speaker for outputting audio signals.

[0140] The input / output interface 812 provides an interface between the processing component 802 and a peripheral interface module, and the peripheral interface module can be a keyboard, a click wheel, buttons, etc. These buttons can include but are not limited to: a home button, a volume button, a power button, and a lock button.

[0141] The sensor component 814 includes one or more sensors for providing status assessments of various aspects of the electronic device 800. For example, the sensor component 814 can detect the on / off state of the electronic device 800, the relative positioning of components, such as the display and keypad of the electronic device 800. The sensor component 814 can also detect a change in the position of the electronic device 800 or a component of the electronic device 800, the presence or absence of user contact with the electronic device 800, the orientation or acceleration / deceleration of the electronic device 800, and the temperature change of the electronic device 800. The sensor component 814 can include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor component 814 can also include a light sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor component 814 can further include an acceleration sensor, a gyro sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0142] The communication component 816 is configured to facilitate communication between the electronic device 800 and other devices in a wired or wireless manner. The electronic device 800 can access a wireless network based on communication standards, such as WiFi, 2G, or 3G, or a combination thereof. In an exemplary embodiment, the communication component 816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 816 further includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology, and other technologies.

[0143] In an exemplary embodiment, the electronic device 800 may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components for performing the above method.

[0144] In an exemplary embodiment, a non - volatile computer - readable storage medium is also provided, such as a memory 804 including computer program instructions, and the above - mentioned computer program instructions can be executed by a processor 820 of the electronic device 800 to complete the above method.

[0145] Figure 8 A block diagram of an electronic device 1900 according to an embodiment of the present disclosure is shown. For example, the electronic device 1900 may be provided as a server. Referring Figure 8 to, the electronic device 1900 includes a processing component 1922, which further includes one or more processors, and memory resources represented by a memory 1932 for storing instructions executable by the processing component 1922, such as application programs. The application programs stored in the memory 1932 may include one or more modules each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute instructions to perform the above method.

[0146] The electronic device 1900 may further include a power component 1926 configured to perform power management of the electronic device 1900, a wired or wireless network interface 1950 configured to connect the electronic device 1900 to a network, and an input / output interface 1958. The electronic device 1900 may operate based on an operating system stored in the memory 1932, such as Windows Server TM , Mac OS X TM , UnixTM, Linux TM , FreeBSD TM or the like.

[0147] In an exemplary embodiment, a non - volatile computer - readable storage medium is also provided, such as a memory 1932 including computer program instructions, and the above - mentioned computer program instructions can be executed by the processing component 1922 of the electronic device 1900 to complete the above method.

[0148] The present disclosure may be a system, a method, and / or a computer program product. The computer program product may include a computer - readable storage medium having thereon computer - readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0149] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium may be, for example—but not limited to—an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punched card or raised structures in grooves having instructions stored thereon, and any suitable combination of the foregoing. The computer-readable storage medium as used herein is not construed as being a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagated through a waveguide or other transmission medium (e.g., an optical pulse through an optical fiber cable), or an electrical signal transmitted through a wire.

[0150] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to respective computing / processing devices, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include a copper transmission cable, an optical fiber transmission, a wireless transmission, a router, a firewall, a switch, a gateway computer, and / or an edge server. A network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in a computer-readable storage medium in each computing / processing device.

[0151] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine - related instructions, microcode, firmware instructions, state - setting data, or source code or object code written in any combination of one or more programming languages, including object - oriented programming languages such as Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" language or similar programming languages. The computer - readable program instructions may be executed entirely on the user's computer, partially on the user's computer, executed as a stand - alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or alternatively, may be connected to an external computer (e.g., through the Internet using an Internet service provider). In some embodiments, by using the state information of the computer - readable program instructions to customize an electronic circuit, such as a programmable logic circuit, a field - programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer - readable program instructions to implement various aspects of the present disclosure.

[0152] Aspects of the present disclosure are described herein with reference to the flowchart and / or block diagram of a method, apparatus (system), and computer program product according to embodiments of the present disclosure. It should be understood that each block of the flowchart and / or block diagram, and the combinations of blocks in the flowchart and / or block diagram, can be implemented by computer - readable program instructions.

[0153] These computer - readable program instructions can be provided to a processor of a general - purpose computer, a special - purpose computer, or other programmable data - processing apparatus to produce a machine such that, when the instructions are executed by the processor of the computer or other programmable data - processing apparatus, a device is created that implements the functions / acts specified in one or more blocks of the flowchart and / or block diagram. These computer - readable program instructions can also be stored in a computer - readable storage medium, which causes a computer, a programmable data - processing apparatus, and / or other devices to operate in a particular manner. Thus, the computer - readable medium storing the instructions includes a manufacture, which includes instructions for implementing various aspects of the functions / acts specified in one or more blocks of the flowchart and / or block diagram.

[0154] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device, causing a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, such that the instructions executed on the computer, other programmable data processing apparatus, or other device implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0155] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a portion of an instruction, which contains one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the figures. For example, two consecutive blocks may in fact be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each block of the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented by a dedicated hardware-based system that performs the specified functions or acts, or by a combination of dedicated hardware and computer instructions.

[0156] The computer program product may be implemented specifically by hardware, software, or a combination thereof. In an alternative embodiment, the computer program product is embodied as a computer storage medium. In another alternative embodiment, the computer program product is embodied as a software product, such as a Software Development Kit (SDK), etc.

[0157] The various embodiments of the present disclosure have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art in the field of the present technology without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application, or the improvement of the technology in the market, or to enable other ordinary skilled persons in the field of the present technology to understand the embodiments disclosed herein.

Claims

1. A method for reducing the vibration of an aircraft, characterized in that, Including: When the aircraft is in the mode conversion stage, obtain the flight data signal collected by the sensor of the aircraft within a historical preset time period, where the mode conversion is a flight mode in which the aircraft switches between a multi-rotor mode and a fixed-wing mode; Determine a signal to be attenuated from the flight data signal after time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range; Determine the adjustment parameter of the structural notch filter according to the signal to be attenuated; After the structural notch filter is adjusted according to the adjustment parameter, use the structural notch filter to filter the control command signal; Before determining the adjustment parameter of the structural notch filter according to the signal to be attenuated, the method includes: Determine the correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; Determining the adjustment parameter of the structural notch filter according to the signal to be attenuated includes: When the correlation coefficient is greater than the correlation coefficient threshold, determine the adjustment parameter of the structural notch filter according to the signal to be attenuated.

2. The method according to claim 1, characterized in that Determining the correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation includes: According to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation, obtain the first auto-power spectral density corresponding to the flight data signal, the second auto-power spectral density corresponding to the control command signal, and the cross-power spectral density between the control command signal and the flight data signal; Determine the correlation coefficient between the flight data signal and the control command signal according to the first auto-power spectral density, the second auto-power spectral density, and the cross-power spectral density.

3. The method according to claim 1, characterized in that Determining the adjustment parameter of the structural notch filter according to the signal to be attenuated includes: Determine the transfer function of the structural notch filter, where the transfer function includes adjustment parameters; Obtain the initial adjustment range of the adjustment parameter; According to the design requirements of the aircraft, determine the parameter adjustment range of the adjustment parameter from the initial adjustment range; Determine the adjustment parameter from the parameter adjustment range according to the signal to be attenuated.

4. The method according to claim 3, wherein The adjustment parameters of the structural notch filter include notch frequency, molecular damping ratio, and denominator damping ratio; Determining the adjustment parameter from the parameter adjustment range according to the signal to be attenuated includes: Determine the notch frequency according to the vibration center frequency of the signal to be attenuated; Obtain the optimization target of the signal to be attenuated, where the optimization target is the attenuation amplitude of the signal to be attenuated; Determine the molecular damping ratio and the denominator damping ratio from the parameter adjustment range according to the notch frequency, the optimization target, and the transfer function.

5. The method according to claim 1, wherein Obtaining the flight data signal collected by the sensor of the aircraft within a historical preset time period includes: Obtain the flight data signal of the aircraft in the previous cycle according to a preset period; Determining the signal to be attenuated from the flight data signal after time-frequency transformation includes: Determine a signal to be attenuated based on the flight data signal in the previous cycle; Determining adjustment parameters of the structural notch filter according to the signal to be attenuated includes: In the next cycle, determine the adjustment parameters of the structural notch filter according to the signal to be attenuated.

6. The method according to claim 1, wherein Before obtaining the flight data signal collected by the sensor of the aircraft in the historical preset time period, the method includes: Superimpose a scanning excitation and / or a stepped maneuver of a longitudinal time series on the control command.

7. An aircraft vibration mitigation device, characterized in that, Including: A flight data signal acquisition module, configured to acquire a flight data signal collected by a sensor of an aircraft in a historical preset time period when the aircraft is in a mode conversion stage, where the mode conversion is a flight mode in which the aircraft switches between a multi-rotor mode and a fixed-wing mode; A signal to be attenuated determination module, configured to determine a signal to be attenuated from the flight data signal after time-frequency transformation, where the amplitude of the signal to be attenuated exceeds a defined vibration amplitude, and the center frequency of the signal to be attenuated is within a predetermined range; An adjustment parameter determination module, configured to determine adjustment parameters of the structural notch filter according to the signal to be attenuated; A filtering module, configured to filter the control command signal using the structural notch filter after the structural notch filter is adjusted according to the adjustment parameters; The apparatus includes: a correlation coefficient determination module, configured to determine a correlation coefficient between the flight data signal and the control command signal according to the flight data signal after time-frequency transformation and the control command signal after time-frequency transformation; the adjustment parameter determination module includes: an adjustment parameter determination sub-module, configured to determine the adjustment parameters of the structural notch filter according to the signal to be attenuated when the correlation coefficient is greater than a correlation coefficient threshold.

8. An electronic device, characterized in that, Including: A processor; A memory for storing instructions executable by the processor; Wherein, the processor is configured to implement the method according to any one of claims 1 to 6 when executing the instructions stored in the memory.

9. A non-volatile computer-readable storage medium having computer program instructions stored thereon, characterized in that, The computer program instructions, when executed by the processor, implement the method according to any one of claims 1 to 6.

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