Active noise reduction method, storage medium, active noise reduction controller, and aircraft

Abstract

Embodiments of the present application disclose an active noise reduction method for an aircraft cabin, a storage medium, an active noise reduction controller and an aircraft. In the embodiments, a plurality of vibration sensors are used to collect a plurality of vibration signals of the aircraft body, and a reference signal is determined according to the plurality of vibration signals. A noise suppression signal is determined according to the reference signal and an adaptive adjustment coefficient, and the noise suppression signal is output through a loudspeaker in a noise reduction area. A noise residual signal in the noise reduction area is collected, and the adaptive adjustment coefficient is updated according to the noise residual signal and the reference signal. The noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled. Based on the updated adaptive adjustment coefficient, the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient is performed until the intensity of the noise residual signal is less than a preset threshold, so as to achieve a good active noise reduction effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft technology, in particular to an active noise reduction method for an aircraft cabin, a storage medium, an active noise reduction controller and an aircraft. BACKGROUND

[0002] If the noise of the aircraft cabin is large, it will seriously affect the comfort of the passengers, so it is necessary to reduce the noise of the aircraft cabin. At present, most of the noise reduction measures still remain in passive noise reduction. The passive noise reduction method is to install sound-absorbing materials in the cabin to reduce noise when dealing with low-frequency noise. However, due to the long wavelength of low-frequency noise, a large amount of sound-absorbing materials are needed, which will increase the size and weight of the aircraft. Moreover, the passive noise reduction method can only have a certain noise reduction effect on the pre-set frequency, and once the noise frequency fluctuates, the noise reduction effect will be significantly reduced. It can be seen that the noise reduction effect of the aircraft cabin is poor at present. SUMMARY

[0003] The embodiments of the present application provide an active noise reduction method for an aircraft cabin, a storage medium, an active noise reduction controller and an aircraft, which can improve the noise reduction effect of the aircraft cabin.

[0004] In a first aspect, the embodiments of the present application provide an active noise reduction method for an aircraft cabin, comprising:

[0005] Collecting a plurality of vibration signals of the fuselage through a plurality of vibration sensors, and determining a reference signal according to the plurality of vibration signals;

[0006] Determining a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and outputting the noise suppression signal through a loudspeaker of a noise reduction area;

[0007] Collecting a noise residual signal of the noise reduction area, and updating the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled out;

[0008] Returning to the operation of determining a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and outputting the noise suppression signal through a loudspeaker of a noise reduction area based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than a preset threshold.

[0009] In a second aspect, the embodiments of the present application also provide a computer-readable storage medium having a computer program stored thereon, which, when executed on a computer, causes the computer to execute the active noise reduction method for an aircraft cabin provided by any of the embodiments of the present application.

[0010] In a third aspect, the embodiments of the present application also provide an active noise reduction controller, which is configured to:

[0011] collect a plurality of vibration signals of the fuselage through a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals;

[0012] determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker in a noise reduction area;

[0013] collect a noise residual signal of the noise reduction area, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled out;

[0014] return to the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and output the noise suppression signal through the loudspeaker in the noise reduction area based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than a preset threshold.

[0015] In a fourth aspect, the embodiments of the present application also provide an aircraft, which comprises:

[0016] a plurality of vibration sensors arranged on a fuselage of the aircraft;

[0017] a loudspeaker, wherein a cabin of the aircraft is divided into at least one noise reduction area, and each noise reduction area is provided with at least one loudspeaker;

[0018] a microphone, and each noise reduction area is provided with at least one microphone; and

[0019] an active noise reduction controller, which is configured to:

[0020] receive a plurality of vibration signals of the fuselage collected by the plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals;

[0021] determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker in a noise reduction area;

[0022] receive a noise residual signal transmitted by the microphone, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled out;

[0023] Return to perform the operation of determining a noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and outputting the noise suppression signal through the speaker of the noise reduction area, based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than the preset threshold.

[0024] The technical scheme provided by the embodiment of the application comprises the following steps: setting vibration sensors on the fuselage of the aircraft to collect a plurality of vibration signals corresponding to noise sources, determining a reference signal from the plurality of vibration signals, generating a noise suppression signal based on the reference signal and an adaptive adjustment coefficient which can be adaptively adjusted, and outputting the noise suppression signal in a noise reduction area. The noise suppression signal can offset the original noise signal in the noise reduction area to reduce noise. At the same time of noise offsetting, a noise residual signal is generated. The adaptive adjustment coefficient is adaptively adjusted based on the noise residual signal, and the noise suppression signal is adjusted. The noise suppression signal output by the noise reduction area is dynamically adjusted iteratively, so that the intensity of the noise residual signal in the area is less than a preset threshold, to achieve a good active noise reduction effect. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0026] Figure 1 The flowchart of the active noise reduction method for the aircraft cabin provided by the embodiment of the application.

[0027] Figure 2 The noise offset principle diagram of the aircraft cabin provided by the embodiment of the application.

[0028] Figure 3 The structural diagram of the aircraft provided by the embodiment of the application.

[0029] Figure 4 The structural diagram of the active noise reduction controller provided by the embodiment of the application.

[0030] Figure 5 The installation position diagram of the speaker, the microphone and the vibration sensor in the aircraft provided by the embodiment of the application. DETAILED DESCRIPTION

[0031] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described in the following. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0032] Reference herein to“an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive or alternative embodiments. It is expressly understood that the embodiments described herein are combinable with each other.

[0033] In the following detailed description, directional terms such as“left”,“right”,“top”,“bottom”,“front”,“back” and the like are used with reference to the orientation of the figures described herein. The components of the embodiments of the present application can be oriented in various different directions, and the directional terms are used for the purpose of example and are not limiting.

[0034] The embodiment of the present application provides an active noise reduction method for an aircraft cabin, and the execution subject of the active noise reduction method for the aircraft cabin can be an active noise reduction device for the aircraft cabin provided by the embodiment of the present application, or an aircraft integrated with the active noise reduction device for the aircraft cabin. The active noise reduction device for the aircraft cabin can be realized in the form of hardware or software. The aircraft can be a commercial aircraft.

[0035] Please refer to Figure 1 , Figure 1 The flowchart of the active noise reduction method for the aircraft cabin provided by the embodiment of the present application is shown. The specific process of the active noise reduction method for the aircraft cabin provided by the embodiment of the present application can be as follows:

[0036] 101, collect a plurality of vibration signals of the fuselage through a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals.

[0037] When the aircraft is flying, the operation of the engine rotor and other components of the aircraft can cause the vibration of the aircraft structure at the position, such as the vibration of the structure of the hanging connection frame, the aircraft skin and the like. The vibration can cause the noise in the cabin. In order to prevent the passengers and the cabin crew from being affected by the noise when they are on the aircraft, the embodiment of the present application adopts the active noise reduction technology, generates a noise suppression signal which is opposite to the original noise signal through the analysis of the vibration, and the noise suppression signal and the original noise signal can offset each other to reduce or even eliminate the noise.

[0038] The noise is caused by vibration of the aircraft body structure, so a plurality of vibration sensors are arranged on the aircraft body to collect vibration signals of the aircraft body. Specifically, a plurality of suitable mounting positions can be selected on the aircraft body according to the specific aircraft body structure and the size of the aircraft body, and a vibration sensor is arranged at each position to collect vibration signals of the corresponding position. In this way, during the flight of the aircraft, the plurality of vibration sensors can continuously collect vibration signals at a preset collection frequency, and send the collected vibration signals to the active noise reduction controller, and the active noise reduction controller determines the reference signal according to the received vibration signals.

[0039] In addition, when the internal space of the cabin is relatively large, the intensities of the original noise signals of different regions can also be different. In order to improve the noise reduction effect, the internal space of the cabin can be divided into a plurality of noise reduction regions, for example, the region occupied by two adjacent seats and the surrounding range thereof is divided into a noise reduction region. For example, the cabin of an aircraft has 100 seats, and the cabin can be divided into 50 noise reduction regions. For each noise reduction region, the original noise signal of the noise reduction region is collected separately, and the corresponding noise suppression signal is generated.

[0040] In another embodiment, the plurality of vibration signals of the aircraft body are collected by the plurality of vibration sensors, and the reference signal is determined according to the plurality of vibration signals, including: collecting the plurality of vibration signals of the aircraft body by the plurality of vibration sensors; obtaining a plurality of vibration signal subsets according to the plurality of vibration signals; calculating the coherence degree between each vibration signal and the original noise signal; calculating the coherence degree between each vibration signal subset and the original noise signal according to the coherence degree between each vibration signal and the original noise signal; determining the vibration sensor corresponding to the vibration signal subset with the highest coherence degree as the target vibration sensor; obtaining the target vibration signal of the target vibration sensor, and generating the reference signal according to the target vibration signal.

[0041] The vibration sensors are arranged at a plurality of positions of the aircraft body, but the generation of the original noise signal in the cabin is not necessarily highly related to the vibration at each position. Therefore, in the embodiment of the present application, the vibration sensor with the highest correlation degree is determined through correlation analysis between the vibration signal and the original noise signal, and the reference signal is determined according to the vibration signal of the vibration sensor with the highest correlation degree. In addition, the noise in the cabin is generally caused by the coupling of vibrations at a plurality of positions of the aircraft body structure. Based on this, a plurality of vibration signals can be divided into a plurality of vibration signal subsets. For example, a total of 10 vibration sensors are arranged on the aircraft body, so that 10 vibration signals can be collected at the same time. Each 3 vibration signals are divided into a subset, so that a plurality of vibration signal subsets are obtained. The number of vibration signals in one vibration signal subset can be set as required, and the above number is only for illustration.

[0042] Then, for each vibration signal, the coherence degree between the vibration signal and the original noise signal is calculated separately. Wherein, the original noise signal of the area is collected by the sound collection device arranged in the noise reduction area. The coherence degree between the vibration signal and the original noise signal can be calculated according to the coherence function. The calculation formula of the coherence function is as follows:

[0043]

[0044] Wherein, is the i-th vibration signal in the vibration signal subset, and d is the original noise signal.

[0045] It can be understood that generally, the vibration signal and the original noise signal collected directly are analog signals, which are converted into digital signals before calculation, and then the calculation is performed according to the digital signals.

[0046] In the above calculation formula, Wherein, w represents the angular frequency, is the autocorrelation of the vibration signal in the form of a vector or a matrix, such as a frequency spectrum or a power spectrum. d(w) is the autocorrelation of the original noise signal in the form of a vector or a matrix, such as a frequency spectrum or a power spectrum. represents the conjugate operation, d T (w) represents the transpose operation of the vector or matrix d(w), and E() represents the expectation operation.

[0047] After calculating the coherence degree between each vibration signal and the original noise signal, the coherence degree between a vibration signal subset and the original noise signal is calculated next.

[0048] As an embodiment, the coherence degree between each vibration signal subset and the original noise signal is calculated according to the coherence degree between each vibration signal and the original noise signal, which includes: for each vibration signal subset, calculating the average value of the coherence degree between each vibration signal in the vibration signal subset and the original noise signal, and taking the average value as the coherence degree between the vibration signal subset and the original noise signal.

[0049] Alternatively, as another embodiment, the coherence degree between each vibration signal subset and the original noise signal is calculated according to the coherence degree between each vibration signal and the original noise signal, which includes: based on the multiple coherence function, calculating the coherence degree between each vibration signal subset and the original noise signal d

[0050] The calculation formula of the multiple coherence function is as follows:

[0051]

[0052] Where K is the number of vibration signals in the vibration signal subset. to There is no restriction on the order; the K vibration signals in the vibration signal subset can be arranged in any order.

[0053] in, This means removing the signal from signal d. After composition, the remaining signal and signal Coherence; This means removing the signal from signal d. After composition, the remaining signal and signal The coherence.

[0054] After calculating the coherence between each vibration signal subset and the original noise signal in the above manner, the vibration signal subset with the highest coherence, i.e. the strongest coherence, is determined as the target vibration signal subset. The multiple vibration sensors corresponding to this target vibration signal subset are determined as target sensors. In other words, the noise generated in the cabin is mainly caused by the vibration at the locations of these target vibration sensors. Subsequently, a reference signal can be determined based on the target vibration signals collected by the target vibration sensors, for example, by superimposing multiple vibration signals to obtain the reference signal.

[0055] Understandably, the determination of the target vibration sensor only requires one calculation. After the target vibration sensor is determined, the subsequent adaptive adjustment coefficients do not need to redetermine the target vibration sensor when updating. They can directly obtain the vibration signals collected by the sensor to generate reference signals.

[0056] 102. The noise suppression signal is determined based on the reference signal and the adaptive adjustment coefficient, and the noise suppression signal is output through the loudspeaker in the noise reduction area.

[0057] After obtaining the reference signal, the noise suppression signal is determined based on the reference signal and the adaptive adjustment coefficients. The formula for calculating the noise suppression signal y(n) is as follows:

[0058] y(n)=W T (n)*x(n)

[0059] W T x(n) is the adaptive adjustment coefficient, and x(n) is the reference signal.

[0060] As mentioned above, the present application generates a noise suppression signal which is opposite to the original noise signal in vibration condition. In ideal condition, the noise suppression signal has the same frequency and amplitude as the original noise signal, but opposite phase, so that the original noise signal and the noise suppression signal can offset each other to achieve the effect of noise reduction.

[0061] Wherein, the adaptive adjustment coefficient is not a fixed value. The reason is as follows: due to the existence of original noise transmission channel, suppression noise transmission channel and environmental influence and other factors, the calculated noise suppression signal may not completely offset the original noise signal, but a noise residual signal is generated. As shown in the following formula: Figure 2 Figure 2 The noise cancellation principle diagram of aircraft cabin provided by the embodiment of the present application is shown in the following figure. The principle can be expressed by the following formula:

[0062] e(n) = d(n) - y'(n)

[0063] Wherein, n is the time index, e(n) is the noise residual signal, d(n) is the original noise signal, and y'(n) is the signal after the noise suppression signal is transmitted through the transmission path.

[0064] When the intensity of noise residual signal e(n) is too high, the noise reduction effect will be poor. Therefore, in order to achieve good noise reduction effect, it is necessary to make the intensity of noise residual signal as small as possible. Therefore, the adaptive filter is used to determine the adaptive adjustment coefficient in the present application, and the noise residual signal and the reference signal are used as the input of the adaptive filter. Through the operation of the adaptive filter, the new adaptive adjustment coefficient is output. The process will be described in detail below.

[0065] 103, collect the noise residual signal of the noise reduction area, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is the signal formed after the noise suppression signal and the original noise signal are offset.

[0066] The loudspeaker and the microphone are arranged in the noise reduction area, for example, the loudspeaker is arranged on the interior decoration above the seat for outputting the noise suppression signal, and the microphone is arranged on both sides of the seat for collecting the noise residual signal. Since the output noise suppression signal will produce error after passing through the transmission path, the formula of the above noise cancellation principle can also be expressed as follows:

[0067] e(n) = d(n) - y'(n) = d(n) - s(n) * y(n) = d(n) - s(n) * [W T (n)x(n)]

[0068] Wherein, * represents linear convolution operation, s(n) is channel error function, and W T ​(n) is an adaptive adjustment coefficient, x(n) is a reference signal, and y(n) is a noise suppression signal. The channel error function is preset and stored in a storage area of the active noise reduction controller.

[0069] Then, the adaptive adjustment coefficient w(n) is updated according to the filtered-x least mean square algorithm, the noise residual signal, and the reference signal. T (n). That is, according to the FXLMS (filtered-x least mean square) algorithm, the w that makes |e(n)| minimum is calculated. Since |e(n)| is not derivable at the minimum point, |e(n)| is used. 2 . 2 .

[0070] Assuming that a mean square cost function is represented as ξ(n) = E[e 2 (n)], the adaptive filter minimizes the instantaneous square error, and then ξ(n) = e 2 (n).

[0071] Using the gradient descent algorithm, the filter coefficients in the negative gradient direction are updated according to the step size, and then the iterative formula is represented as:

[0072]

[0073] wherein, is an instantaneous estimate of the gradient of the mean square error at time n. μ is a fixed step size factor, and the size of μ largely determines the convergence and steady-state performance of the algorithm. The larger μ is, the faster the algorithm converges, but the larger the steady-state error is. The smaller μ is, the slower the algorithm converges, but the smaller the steady-state error is. Generally, the value of μ can be selected within a reasonable range.

[0074] According to the above formula, the new adaptive adjustment coefficient is calculated according to the collected noise residual signal.

[0075] In an embodiment, the channel error function is obtained as follows: when the aircraft is in a stationary state, a first white noise signal is output through a speaker in the noise reduction area, and a second white noise signal is collected through a microphone in the preset area after passing through the transmission path. The channel error function is determined according to the first white noise signal and the second white noise signal.

[0076] In this embodiment, when the aircraft is in a stationary state, i.e. not flying, a white noise signal is played through the loudspeaker of the noise reduction area, and at the same time, the white noise signal after passing through the transmission path is collected through the microphone of the area, obtaining a new white noise signal. The error between the collected second white noise signal and the played first white noise signal is the noise of the transmission path, so according to the first white noise signal and the second white noise signal, the channel error function can be determined. The channel error function represents the error of the sound signal passing through the transmission path.

[0077] 104、Based on the updated adaptive adjustment coefficient, return to perform the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and outputting the noise suppression signal through the loudspeaker of the noise reduction area, until the intensity of the noise residual signal is less than the preset threshold.

[0078] After the adaptive filter algorithm outputs the new adaptive adjustment coefficient, the noise suppression signal is recalculated based on the new adaptive adjustment coefficient, and the noise suppression signal is output through the loudspeaker of the noise reduction area. Then, the noise residual signal is collected through the microphone of the noise reduction area, and it is judged whether the intensity is less than the preset threshold. If yes, the current noise suppression signal is continuously output, and the noise residual signal is collected periodically. Otherwise, if the intensity of the noise residual signal is greater than or equal to the preset threshold, the noise residual signal and the reference signal are taken as the input of the adaptive filter, and the new adaptive adjustment coefficient is output through the operation of the adaptive filter. Iterative operation is performed until the intensity of the noise residual signal is less than the preset threshold.

[0079] As can be seen from the foregoing description, the adaptive adjustment coefficient is continuously updated under certain conditions. Therefore, the initial value of the adaptive adjustment coefficient can be a randomly selected value of the adaptive filter, or a value obtained by iterative calculation during the noise reduction processing of the aircraft during the last flight. That is, after each flight, the adaptive adjustment coefficient obtained by iterative calculation during the noise reduction processing of the current flight can be stored for use as the initial value during the next noise reduction processing.

[0080] It can be understood that for multiple noise reduction areas in the cabin, the corresponding noise imprint signals can be calculated and output according to the above description to achieve active noise reduction.

[0081] In specific implementation, the present application is not limited by the execution order of the various steps described, and certain steps can also be performed in other order or simultaneously without conflict.

[0082] It can be learned from the above that the active noise reduction method of the aircraft cabin provided by the embodiment of the present application sets the vibration sensor on the aircraft body to collect a plurality of vibration signals corresponding to the noise source, determines the reference signal from the plurality of vibration signals, generates a noise suppression signal based on the reference signal and an adaptive adjustment coefficient which can be adaptively adjusted, and outputs the noise suppression signal in the noise reduction area. The noise suppression signal can offset the original noise signal of the noise reduction area to reduce the noise, and at the same time of noise offset, a noise residual signal is generated. The adaptive adjustment coefficient is adaptively adjusted based on the noise residual signal, and then the noise suppression signal is adjusted. In this way, the noise suppression signal output by the noise reduction area is dynamically adjusted iteratively, so that the intensity of the noise residual signal of the area is less than the preset threshold, so as to achieve good active noise reduction effect.

[0083] In an embodiment, an active noise reduction device of an aircraft cabin is also provided. The active noise reduction device of the aircraft cabin comprises a reference determination module, a signal generation module and a weight update module, as follows:

[0084] The reference determination module is configured to collect a plurality of vibration signals of the aircraft body through a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals.

[0085] The signal generation module is configured to determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker of the noise reduction area.

[0086] The weight update module is configured to collect a noise residual signal of the noise reduction area, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and the original noise signal are offset.

[0087] The signal generation module is also configured to perform the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and outputting the noise suppression signal through the loudspeaker of the noise reduction area based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than the preset threshold.

[0088] It should be noted that the active noise reduction device of the aircraft cabin provided by the embodiment of the present application and the active noise reduction method of the aircraft cabin in the above embodiment belong to the same concept. The active noise reduction device of the aircraft cabin can realize any method provided in the active noise reduction method of the aircraft cabin embodiment. The specific implementation process is described in detail in the active noise reduction method of the aircraft cabin embodiment, which will not be described here.

[0089] It can be known from the above that the active noise reduction device of the aircraft cabin provided in the embodiment of the present application sets the vibration sensor on the aircraft body to collect a plurality of vibration signals corresponding to the noise source, determines the reference signal from the plurality of vibration signals, generates a noise suppression signal based on the reference signal and an adaptive adjustment coefficient which can be adaptively adjusted, and outputs the noise suppression signal in the noise reduction area, the noise suppression signal can be offset with the original noise signal of the noise reduction area to reduce the noise, and at the same time of noise offset, a noise residual signal is generated, the adaptive adjustment coefficient is adaptively adjusted based on the noise residual signal, and then the noise suppression signal is adjusted, so that the noise suppression signal output by the noise reduction area is dynamically adjusted iteratively, so that the intensity of the noise residual signal of the area is less than the preset threshold, so that a good active noise reduction effect is achieved.

[0090] The embodiment of the present application also provides an active noise reduction controller, which is configured to:

[0091] Collect a plurality of vibration signals of the aircraft body through a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals;

[0092] Determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker of the noise reduction area;

[0093] Collect a noise residual signal of the noise reduction area, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal is offset with the original noise signal;

[0094] Return to perform the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and outputting the noise suppression signal through the loudspeaker of the noise reduction area based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than the preset threshold.

[0095] It should be explained that the active noise reduction controller provided in the embodiment of the present application and the active noise reduction method of the aircraft cabin in the above embodiment belong to the same inventive concept, the active noise reduction controller is configured to realize any method provided in the active noise reduction method of the aircraft cabin, and the specific implementation process is referred to the active noise reduction method of the aircraft cabin, which will not be described here.

[0096] The embodiment of the present application also provides an aircraft. Please refer to Figure 3 , Figure 3 The structure schematic diagram of the aircraft provided in the embodiment of the present application. The aircraft 400 comprises:

[0097] a plurality of vibration sensors 410 disposed on the fuselage of the aircraft 400;

[0098] a speaker 420, wherein the cabin of the aircraft 400 is divided into at least one noise reduction area, and each noise reduction area is provided with the speaker 420;

[0099] a microphone 430, and each noise reduction area is provided with the microphone 430; and

[0100] an active noise reduction controller 440, which is configured to:

[0101] receive a plurality of vibration signals collected by the plurality of vibration sensors 410 from the fuselage, and determine a reference signal according to the plurality of vibration signals;

[0102] determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through the speaker 420 of the noise reduction area;

[0103] receive a noise residual signal transmitted by the microphone, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled out;

[0104] return to the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient, and outputting the noise suppression signal through the speaker 420 of the noise reduction area based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than a preset threshold.

[0105] In this embodiment, vibration sensors 410 are installed on the fuselage structure of the aircraft, and the vibration sensors 410 transmit the collected vibration signals to the active noise reduction controller 440, and the active noise reduction controller 440 determines a reference signal according to the plurality of vibration signals. In addition, the microphone 430 disposed in each noise reduction area collects a noise residual signal and sends it to the active noise reduction controller 440, and the active noise reduction controller 440 iteratively updates the adaptive adjustment coefficient according to the noise residual signal and the reference signal, and calculates the noise suppression signal based on the latest adaptive adjustment coefficient and transmits it to the speaker 420 of the noise reduction area for playing. In the noise reduction area, the original noise signal and the noise suppression signal cancel each other out, and at the same time of noise cancellation, a noise residual signal is generated. Based on the noise residual signal, the adaptive adjustment coefficient is adaptively adjusted, and the noise suppression signal is adjusted, so that the noise suppression signal output by the noise reduction area is iteratively and dynamically adjusted, so that the intensity of the noise residual signal in the area is less than a preset threshold, so as to achieve good active noise reduction effect.

[0106] Please refer toFigure 4 , Figure 4 The structure diagram of the active noise reduction controller provided by the embodiment of the present application is shown in FIG. 1.

[0107] In some embodiments, the active noise reduction controller 440 comprises:

[0108] an analog-to-digital conversion unit 441 configured to convert the received vibration signals and noise residual signals from analog signals to digital signals;

[0109] a digital-to-analog conversion unit 442 configured to convert the calculated noise suppression signals from digital signals to analog signals;

[0110] a power amplifier unit 443 configured to amplify the noise suppression signals converted to analog signals; and

[0111] a control unit 444 configured to determine a reference signal according to the vibration signals, determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and transmit the amplified noise suppression signals to the loudspeakers;

[0112] update the adaptive adjustment coefficient according to the noise residual signals and the reference signal, wherein the noise residual signals are signals formed after the noise suppression signals are cancelled with original noise signals;

[0113] and return to perform the operation of determining a noise suppression signal according to the reference signal and the adaptive adjustment coefficient based on the updated adaptive adjustment coefficient until the intensity of the noise residual signals is less than the preset threshold.

[0114] In some embodiments, the signals collected by the vibration sensors and microphones are generally analog signals, which are converted to digital signals by the analog-to-digital conversion unit 441 for subsequent calculation. The calculated noise suppression signals are digital signals, which are converted to analog signals by the digital-to-analog conversion unit 442 for subsequent output.

[0115] In some embodiments, each region in the cabin where a preset number of seats are located is a noise reduction region. For each noise reduction region, at least one loudspeaker is arranged in the interior region of the cabin in the noise reduction region, and at least one microphone is arranged on the seat in the noise reduction region.

[0116] Please refer to Figure 5 , Figure 5The installation position of the loudspeaker, microphone and vibration sensor in the aircraft is shown in the schematic diagram provided by the embodiment of the present application. The installation position of each component in a noise reduction area is shown in the diagram, wherein the left side is the top view of the noise reduction area, and the right side is the left view corresponding to the left side. The noise reduction area corresponds to two seats, and the microphone is installed on both sides of the seat, for example, at the headrest position of the seat or the like. A plurality of loudspeakers are installed in a plurality of directions of the seat, such as in the cabin interior area in front of the seat, above the seat and on the side of the seat.

[0117] It can be understood that, Figure 5 The installation position is shown for the purpose of illustrating the scheme of the embodiment of the present application to the reader, and in other embodiments, the installation position of each component can be reasonably arranged according to the arrangement in the cabin.

[0118] As can be seen from the above, the embodiment of the present application provides an aircraft, which acquires a plurality of vibration signals corresponding to a noise source by arranging a vibration sensor on the fuselage of the aircraft, determines a reference signal from the plurality of vibration signals, generates a noise suppression signal based on the reference signal and an adaptive adjustment coefficient which can be adaptively adjusted, and outputs the noise suppression signal in a noise reduction area. The noise suppression signal can be offset with the original noise signal of the noise reduction area to reduce noise, and at the same time of noise cancellation, a noise residual signal is generated. The adaptive adjustment coefficient is adaptively adjusted based on the noise residual signal, and the noise suppression signal is adjusted, so that the noise suppression signal output by the noise reduction area is dynamically adjusted iteratively, so that the intensity of the noise residual signal in the area is less than a preset threshold, so as to achieve good active noise reduction effect.

[0119] The embodiment of the present application also provides a computer readable storage medium, wherein a computer program is stored in the computer readable storage medium, and when the computer program runs on a computer, the computer executes the active noise reduction method of the aircraft cabin according to any one of the above embodiments. For example, the computer program can perform the following steps:

[0120] Acquire a plurality of vibration signals of the fuselage by a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals;

[0121] Determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker of a noise reduction area;

[0122] Acquire a noise residual signal of the noise reduction area, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal is offset with the original noise signal;

[0123] Based on the updated adaptive adjustment coefficient, the operation of determining a noise suppression signal according to the reference signal and the adaptive adjustment coefficient and outputting the noise suppression signal through the speaker of the noise reduction area is returned to be performed until the intensity of the noise residual signal is less than a preset threshold.

[0124] It should be noted that all or part of the steps in the various methods of the above embodiments can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer readable storage medium, which can include but is not limited to: read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0125] In addition, the terms "first", "second" and "third" and the like in the present application are used to distinguish different objects, not to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or modules is not limited to the listed steps or modules, but some embodiments also include steps or modules that are not listed, or some embodiments also include other steps or modules inherent to the process, method, product or device.

[0126] The above provides a detailed description of the active noise reduction method, storage medium, active noise reduction controller and aircraft provided by the aircraft cabin of the embodiment of the present application. The principle and implementation manner of the present application are described by applying specific examples in this paper. The above embodiment is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed; according to the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A method of active noise reduction for an aircraft cabin, the method comprising: The method comprises the following steps: acquiring a plurality of vibration signals of the fuselage through a plurality of vibration sensors, and determining a reference signal according to the plurality of vibration signals; determining a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and outputting the noise suppression signal through a loudspeaker in a noise reduction area; acquiring a noise residual signal of the noise reduction area, and updating the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and an original noise signal are cancelled out; returning to the operation of determining a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and outputting the noise suppression signal through a loudspeaker in a noise reduction area, based on the updated adaptive adjustment coefficient, until the intensity of the noise residual signal is less than a preset threshold; acquiring a plurality of vibration signals of the fuselage through a plurality of vibration sensors; obtaining a plurality of vibration signal subsets according to the plurality of vibration signals; calculating the coherence degree between each vibration signal and the original noise signal; calculating the coherence degree between each vibration signal subset and the original noise signal according to the coherence degree between each vibration signal and the original noise signal; determining the vibration sensor corresponding to the vibration signal subset with the highest coherence degree as a target vibration sensor; obtaining a target vibration signal of the target vibration sensor, and generating a reference signal according to the target vibration signal; Each area where a preset number of seats in the cabin are located is a noise reduction area; For each noise reduction area, at least one loudspeaker is arranged in a cabin interior area in the noise reduction area, and at least one microphone is arranged on a seat in the noise reduction area.

2. The method of claim 1, wherein, The method further comprises the following steps: calculating the coherence degree between each vibration signal subset and the original noise signal based on a multiple coherence function according to the coherence degree between each vibration signal and the original noise signal.

3. The method of claim 1, wherein, The noise suppression signal and the original noise signal cancel out to form a noise residual signal, which is represented as: Wherein, e(n) is a noise residual signal, d(n) is an original noise signal, s(n) is a channel error function, W T (n) is an adaptive adjustment coefficient, x(n) is a reference signal, y(n) is a noise suppression signal; updating the adaptive adjustment coefficient according to the noise residual signal and the reference signal comprises the following steps: updating the adaptive adjustment coefficient W according to a filtered-x least mean square algorithm, the noise residual signal, and the reference signal T (n).

4. The method of claim 3, wherein, The method further comprises the following steps: When the aircraft is in a stationary state, outputting a first white noise signal through the loudspeaker in the noise reduction area, and acquiring a second white noise signal after the first white noise signal passes through a transmission path through the microphone in the preset area; determining the channel error function according to the first white noise signal and the second white noise signal.

5. A computer-readable storage medium having stored thereon a computer program, characterized in that, When the computer program runs on the computer, the computer is caused to execute the active noise reduction method for the cabin of the aircraft as claimed in any one of claims 1 to 4.

6. An active noise control controller characterized by, The active noise reduction controller is configured to: acquire a plurality of vibration signals of the fuselage through a plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals; determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through a loudspeaker in a noise reduction area; Collecting a noise residual signal of the noise reduction area, updating the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and the original noise signal are cancelled out; Based on the updated adaptive adjustment coefficient, the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient and outputting the noise suppression signal through the speaker in the noise reduction area is performed again until the intensity of the noise residual signal is less than a preset threshold value; Each area in which a preset number of seats in the cabin are located is a noise reduction area; For each noise reduction area, at least one speaker is arranged in a cabin interior area in the noise reduction area, and at least one microphone is arranged on a seat in the noise reduction area.

7. An aircraft, characterized in that The aircraft comprises: a plurality of vibration sensors arranged on the fuselage of the aircraft; a speaker, wherein the cabin of the aircraft is divided into at least one noise reduction area, and each noise reduction area is provided with the speaker; a microphone, and each noise reduction area is provided with the microphone; and an active noise reduction controller configured to: receive a plurality of vibration signals collected by the plurality of vibration sensors, and determine a reference signal according to the plurality of vibration signals; determine a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and output the noise suppression signal through the speaker in the noise reduction area; receive a noise residual signal transmitted by the microphone, and update the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and the original noise signal are cancelled out; based on the updated adaptive adjustment coefficient, the operation of determining the noise suppression signal according to the reference signal and the adaptive adjustment coefficient and outputting the noise suppression signal through the speaker in the noise reduction area is performed again until the intensity of the noise residual signal is less than a preset threshold value; each area in which a preset number of seats in the cabin are located is a noise reduction area; for each noise reduction area, at least one speaker is arranged in a cabin interior area in the noise reduction area, and at least one microphone is arranged on a seat in the noise reduction area.

8. The aircraft of claim 7, wherein, The active noise reduction controller comprises: an analog-to-digital conversion unit for converting the received vibration signals and noise residual signals from analog signals to digital signals; a digital-to-analog conversion unit for converting the calculated noise suppression signal from a digital signal to an analog signal; a power amplifier unit for amplifying the noise suppression signal converted to an analog signal; and a control unit for determining a reference signal according to a plurality of vibration signals, determining a noise suppression signal according to the reference signal and an adaptive adjustment coefficient, and transmitting the amplified noise suppression signal to the speaker; updating the adaptive adjustment coefficient according to the noise residual signal and the reference signal, wherein the noise residual signal is a signal formed after the noise suppression signal and the original noise signal are cancelled out; And, based on the updated adaptive adjustment coefficient, return to perform the operation of determining a noise suppression signal according to the reference signal and the adaptive adjustment coefficient until the intensity of the noise residual signal is less than the preset threshold.

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