Ocean energy device noise control and musical conversion method and system

Abstract

The application discloses a marine energy device noise control and music conversion method and system, relates to the cross technical field of environmental acoustics and soundscape design, and comprises the following steps: collecting original noise signals generated by the operation of a marine energy device, mapping the original noise signals into a pulse event sequence through integral-threshold trigger coding; configuring a high-order pulse shaping filter group composed of multiple sub-band filters in parallel according to a pre-stored frequency spectrum template of a target natural soundscape; inputting the pulse event sequence into the high-order pulse shaping filter group in parallel to generate a soundscape driving signal with the frequency spectrum characteristics of the target natural soundscape; and driving a transducer array after the power amplification of the soundscape driving signal, linearly superimposing the target region and the residual noise sound field after passive noise reduction preprocessing to form a synthetic sound field. Thus, the transformation from noise dominant perception to natural soundscape dominant perception in the target region is realized.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of environmental acoustics and soundscape design, and in particular to a method and system for noise control and musical conversion of marine energy devices. Background Technology

[0002] Ocean energy installations, especially oscillating water column (OWC) wave power generation devices, generate significant aerodynamic noise and low-frequency structural radiation noise underwater during operation. This type of noise not only disturbs the acoustic environment of marine life but also degrades the acoustic quality of the surrounding coastal areas.

[0003] Existing noise control methods are mainly divided into passive noise cancellation and active noise control (ANC). Passive noise cancellation has limited effectiveness against low-frequency noise, and the materials used have poor durability in marine environments. Active noise control technology aims to cancel noise by emitting anti-phase secondary sound waves, but its core algorithms face challenges when dealing with noise from OWC devices: traditional linear algorithms are insufficient in handling non-stationary, impulsive noise; and the introduced nonlinear algorithms are too computationally complex to run in real time on low-power platforms. More importantly, existing ANC technologies only aim at "cancellation" and fail to transform the technically difficult-to-completely-eliminate characteristic residual noise into soundscape elements beneficial to the acoustic environment.

[0004] Introducing specific nonlinear signal coding architectures into the field of acoustic noise shaping presents significant technical obstacles: the continuous time-varying acoustic transfer function of an acoustic system differs significantly in characteristics from the approximate steady electrical transfer function commonly found in electronic systems. Migrating the integral-threshold coding principle from the electrical domain to the acoustic domain requires addressing engineering issues such as integration window mismatch caused by acoustic path delay and compensation for integral gain drift due to environmental temperature and humidity. These issues are rarely considered in typical electronic ADC applications, posing a considerable technical hurdle for those skilled in the art in migrating this coding principle from the electrical domain to the acoustic domain. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and system for noise control and musical conversion of marine energy devices. It adopts a comprehensive strategy of passive noise reduction preprocessing and adaptive acoustic reconstruction based on signal event coding. The aim is to reduce the noise sound pressure level by passive means and reconstruct the remaining noise into a preset natural soundscape in real time through active algorithms.

[0006] In a first aspect, embodiments of the present invention provide a method for noise control and music conversion of a marine energy device, comprising: The raw noise signal generated by the operation of the marine energy device is collected, and the raw noise signal is mapped into a pulse event sequence through integral-threshold trigger coding. When the integral value exceeds a preset threshold, a pulse event is generated and the integral is reset. Based on a pre-stored spectral template of the target natural soundscape, a high-order pulse shaping filter bank consisting of multiple sub-band filters connected in parallel is configured. Each sub-band filter corresponds to a characteristic frequency point in the spectral template and employs... Filter structure, It is an integer not less than 2; The pulse event sequence is input in parallel into the high-order pulse shaping filter bank to generate a sound scene driving signal with the target natural sound scene spectral characteristics; The sound field driving signal is amplified and then drives the transducer array. The transducer array is linearly superimposed on the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

[0007] In a preferred embodiment, the raw noise signal generated by the operation of the marine energy device is collected, and the raw noise signal is mapped into a pulse event sequence through integral-threshold trigger coding, including: The original noise signal is subjected to weighted bandpass filtering using a weighted window function; The filtered signal is continuously integrated. When the integral value reaches the preset integration threshold, a standard pulse event is generated at the current moment, and the integrator is reset to zero and the next integration cycle begins. All pulse events are accumulated in chronological order to form a pulse event sequence.

[0008] In a preferred embodiment, configuring a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel, based on a pre-stored spectral template of the target natural soundscape, includes: With the goal of minimizing the weighted least squares error between the actual frequency response of the higher-order pulse shaping filter bank and the spectral template, the complex gain parameter and phase delay parameter of each sub-band filter are optimized and solved. Configure the high-order pulse shaping filter bank according to the complex gain parameters and phase delay parameters obtained from the optimization solution; The weighting factor in the weighted least squares error is a psychoacoustic weighting factor set according to the normalization of the psychoacoustic loudness curve. The weighting factor has a higher value in the mid-frequency range that the human ear is sensitive to than in the low-frequency and high-frequency ranges.

[0009] In a preferred embodiment, the steps for constructing a single subband filter in the higher-order pulse shaping filter bank specifically include: Based on a preset sampling period, a sampling array is constructed using... A basic low-pass filter prototype in functional form; The transfer function of the higher-order shaping filter is obtained by performing a power operation of at least two powers on the basic low-pass filter prototype. The transfer function of the higher-order shaping filter is multiplied sequentially by the complex gain parameter and phase delay parameter obtained by optimization to obtain a single subband filter; The complex gain parameter is used to control the amplitude and phase of the output signal of the single subband filter at the corresponding characteristic frequency point, and the phase delay parameter is used to adjust the phase of the output of the subband filter.

[0010] In a preferred embodiment, the pulse event sequence is input in parallel into the high-order pulse shaping filter bank to generate a soundscape driving signal with the spectral characteristics of the target natural soundscape, including: The pulse event sequence is simultaneously input into each sub-band filter in the high-order pulse shaping filter bank, and sub-band signals with spectral components at corresponding characteristic frequency points are output respectively. The subband signals output from each subband filter are summed to obtain the soundscape driving signal.

[0011] In a preferred embodiment, the soundscape driving signal is amplified and then used to drive a transducer array. This array is then linearly superimposed on the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field, including: The sound scene driving signal is converted from digital to analog and then sent to a power amplifier for power amplification. The amplified signal drives a transducer array deployed around the target area to radiate secondary sound waves with the spectral characteristics of the target's natural soundscape. The secondary sound wave is linearly acoustically superimposed on the residual noise sound field remaining after passive noise reduction preprocessing in the target area to form a synthetic sound field.

[0012] In a preferred embodiment, after the synthesized sound field is formed, a closed-loop adaptive adjustment step is also included: Collect the residual noise error signal of the synthesized sound field in the target area; The normalized LMS algorithm is adopted, with the mean square value of the residual noise error signal as the cost function. In each wave cycle, the real part of the complex gain parameter of each sub-band filter in the high-order pulse shaping filter bank is finely adjusted online once, while keeping the imaginary part of the complex gain parameter unchanged, so as to compensate for changes in the acoustic environment and maintain the spectral alignment relationship.

[0013] In a preferred embodiment, the method further includes scene matching and smooth switching steps: Real-time calculation of the weighted cosine similarity between the current background noise frequency band spectrum of the target area and the preset scene mode; When the weighted cosine similarity is lower than a preset configurable threshold and the duration exceeds a preset duration, the spectrum template of the new target natural soundscape that best matches the current background sound is retrieved from the music library. Within one wave cycle, the complex gain parameters of the high-order pulse shaping filter bank are smoothly transitioned from their current values ​​to the optimized values ​​of the corresponding new spectral template through linear interpolation, thus completing the seamless switching of the sound scene.

[0014] In a preferred embodiment, the passive noise reduction preprocessing includes: A resistive silencer is installed at the turbine exhaust port of the marine energy device. The resistive silencer uses a salt spray resistant stainless steel shell and basalt fiber sound-absorbing material; a micro-perforated plate sound-absorbing structure is laid on the gas chamber wall.

[0015] Secondly, embodiments of the present invention also provide a noise control and music conversion system for marine energy devices, comprising: The passive noise reduction preprocessing and pulse coding module is used to collect the raw noise signal generated by the operation of the marine energy device, and to map the raw noise signal into a pulse event sequence through integration-threshold triggering coding. When the integration value exceeds a preset threshold, a pulse event is generated and the integration is reset. The filter bank configuration module is used to configure a high-order pulse shaping filter bank consisting of multiple sub-band filters connected in parallel, based on a pre-stored spectral template of the target natural sound scene. Each sub-band filter corresponds to a characteristic frequency point in the spectral template and employs... Filter structure, It is an integer not less than 2; The soundscape driving signal generation module is used to input the pulse event sequence in parallel into the high-order pulse shaping filter bank to generate a soundscape driving signal with the target natural soundscape spectral characteristics. The transducer driving module is used to amplify the sound scene driving signal and drive the transducer array to linearly superimpose it with the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

[0016] Thirdly, embodiments of the present invention also provide an electronic device, the electronic device comprising: One or more processors; Storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement a method for noise control and music conversion of a marine energy device as described in any embodiment of the present invention.

[0017] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a method for noise control and music conversion of a marine energy device as described in any embodiment of the present invention.

[0018] Compared to existing technologies, the following beneficial effects have been achieved: (1) In the simulation comparison experiment of simulated sea conditions, compared with the traditional FxLMS algorithm, the present invention significantly reduces the risk of digital coefficient divergence after the occurrence of impulse noise event, and no filter coefficient divergence phenomenon occurs within the tested parameter range, thereby effectively improving the working stability of the system under complex sea conditions.

[0019] (2) Under the same sampling rate and resource constraints, compared with the first-order pulse shaping structure, the higher-order structure adopted in this invention can increase the attenuation slope outside the target frequency band from 20 dB / dec to 40-60 dB / dec, which is beneficial to confine the residual noise energy more concentrated within the target sound scene frequency band and significantly improve the clarity of the sound scene.

[0020] (3) This invention extends the goal of active acoustic reconstruction from the traditional minimization of residual sound pressure level to modulating residual noise into a soundscape signal with preset spectral characteristics. Preliminary subjective evaluation results show that a shift from noise-dominated perception to natural soundscape-dominated perception can be achieved within the target area. Attached Figure Description

[0021] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a flowchart of a method for noise control and music conversion of a marine energy device provided in an embodiment of the present invention; Figure 2 This is an overall technical roadmap of a method for noise control and music conversion of a marine energy device provided by an embodiment of the present invention; Figure 3 This is a flowchart of the signal processing inside the robust pulse event encoder provided in an embodiment of the present invention; Figure 4(a) is a simulation diagram of the output sound pressure level spectrum under simulated OWC noise input provided in the embodiment of the present invention; Figure 4(b) is a simulation diagram of the output sound pressure level spectrum under simulated OWC noise input provided in the embodiment of the present invention; Figure 5 This is a schematic diagram of the structure of a marine energy device noise control and music conversion system provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0023] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as being processed sequentially, many of these operations (or steps) may be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations may be rearranged. The process may be terminated when its operation is completed, but may also have additional steps not included in the figures. The process may correspond to a method, function, procedure, subroutine, subroutine, etc.

[0024] Example 1: Embodiment 1 of the present invention provides a method for noise control and music conversion of marine energy devices, wherein the system for executing the method specifically includes the following subsystems: Passive noise reduction pretreatment subsystem: A resistive silencer is installed at the turbine exhaust port, using a salt spray-resistant stainless steel shell and basalt fiber sound-absorbing material; a micro-perforated plate sound-absorbing structure is laid on the gas chamber wall, and structural parameters are selected based on existing silencer design methods to achieve approximately [missing information - likely a noise reduction effect] within the main noise frequency band of 500 Hz to 2 kHz. Insertion loss.

[0025] The air acoustic control subsystem comprises an air reference microphone array and an air acoustic loudspeaker array, deployed near the air chamber opening and turbine platform of the Oscillating Water Column (OWC) wave energy generator. Specifically, the air acoustic subsystem includes four weather-resistant broadband reference microphones (deployed outside the air chamber opening) and a horn-type compressor driven by four microphones with a rated acoustic power of not less than 200 W.

[0026] The underwater acoustic control subsystem comprises a hydrophone array and an underwater acoustic transducer array, deployed around the underwater structure of the device, specifically for shaping the underwater acoustic landscape. In this embodiment, the underwater acoustic subsystem includes two hydrophones and one omnidirectional transducer, deployed at a depth of 5-8 m.

[0027] The core processing board mainly includes six logic modules: noise coding, filter bank, multi-scene management, online fine-tuning, and error feedback control.

[0028] like Figure 1 As shown, the method 100 for noise control and music conversion of a marine energy device provided in this embodiment specifically includes the following steps: Step S110: Collect the raw noise signal generated by the operation of the marine energy device, and map the raw noise signal into a pulse event sequence through integration-threshold triggering encoding, wherein when the integration value exceeds a preset threshold, a pulse event is generated and the integration is reset.

[0029] Taking a 500 kW oscillating water column (OWC) wave energy generator deployed near the shore as an example, a weather-resistant broadband reference microphone array is deployed near the gas chamber opening and turbine platform of the device. The aerodynamic noise signal generated by the turbine operation is acquired at a sampling frequency of 48 kHz and a quantization width of 24 bits. The acquired raw noise signal is then processed... Input robust pulse event encoder, i.e. integral-threshold triggered encoder.

[0030] Among them, such as Figure 3 As shown, the original noise signal is mapped into a sequence of pulse events using an integral-threshold triggered encoder, including the following processing steps: First, the original noise signal Weighted window function Bandpass filtering is performed, with the passband set to 80Hz–2000Hz to emphasize the frequency band where noise energy is concentrated and overlaps with the target soundscape. The filtered signal is then continuously integrated. When the integrated value reaches a preset integration threshold, a standard pulse event is generated at that moment, and the integrator is reset to zero and begins the next integration cycle. Finally, all pulse events are accumulated in chronological order to form a pulse event sequence. .

[0031] Specifically, the formula for calculating the pulse event sequence is as follows: ; , The unit impulse function; It is a continuous-time variable; For the first The occurrence time of each pulse event is determined by... The decision is made such that the value of the independent variable is infinity where it is zero, and zero elsewhere, and the area of ​​the integral is one. For the first The timing of each pulse event; This is a weighted window function used to emphasize specific frequency components; The preset integration threshold is used to determine whether a pulse event is triggered. : Integral dummy variable, representing the time since the last impulse event. The integral time variable from the start to the current time.

[0032] The output of this encoding method Mathematically, this can be expanded into a pulse sequence with a rich spectrum. This sequence exhibits logarithmic nonlinear compression characteristics to changes in the amplitude of the input signal, which is helpful for subsequent processing of impulsive noise. Furthermore, the integrator reset mechanism, with reasonable settings of the numerical bit width and threshold, can significantly reduce the risk of digital overflow and improve adaptability to changes in the dynamic range of the signal.

[0033] Step S120: Based on the pre-stored spectrum template of the target natural soundscape, configure a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel. Each sub-band filter corresponds to a characteristic frequency point in the spectrum template and uses... Filter structure, It is an integer not less than 2.

[0034] In a preferred embodiment, the high-order pulse shaping filter bank consists of Subband filter Formed in parallel, each sub-band filter corresponds to a specific characteristic frequency in the target soundscape spectrum. Use higher order The filter structure achieves steep spectral shaping, and its Laplace domain transfer function is: ; in, For the first Laplace domain transfer function of subband filter For the first The complex gain parameter of each subband filter is a complex number containing amplitude and phase information, used to control the amplitude and phase of the output signal of the subband filter at the corresponding characteristic frequency point. For Laplace complex variables; The system sampling period; For noise shaping order, in this invention, ; This is the complex gain of the sub-band, used to precisely control the amplitude and phase of the output signal; For the first The phase delay parameter of each subband filter is used to perform fine phase adjustment on the output of the subband filter.

[0035] Through optimization and The entire filter bank The frequency response will be presented as the spectral envelope of a specific natural soundscape. This is the domain B transfer function of a high-order pulse shaping filter bank, used to convert a sequence of pulse events into a driving signal with the spectral characteristics of the target soundscape.

[0036] In a preferred embodiment, the steps for constructing a single subband filter in the higher-order pulse shaping filter bank specifically include: A basic low-pass filter prototype is provided, whose transfer function is: ,in, The system sampling period is For Laplace complex variables; The basic low-pass filter prototype was subjected to... Exponentiation, to obtain Transfer function of an 1st order shaping filter It is an integer not less than 2; The The transfer function of the first-order shaping filter is multiplied by a complex gain parameter. The complex gain parameter This is used to control the amplitude and phase of the output signal of the subband filter at the corresponding characteristic frequency point; the transfer function multiplied by the complex gain parameter is then multiplied by a phase delay term. ,in, This is the phase delay parameter, used for fine phase adjustment of the subband filter output; The transfer function of a single subband filter is obtained through the above steps. ; Multiple sub-band filters corresponding to different characteristic frequency points are connected in parallel to form the higher-order pulse shaping filter group.

[0037] As a preferred embodiment, based on a pre-stored spectral template of the target natural soundscape, a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel is configured, including the following steps: Soundscape Spectrum Template Extraction: A pre-built music score library stores the features of each natural soundscape in the form of Fourier spectrum amplitude peak envelope vectors. For example, the spectrum template of a "tidal wave and spray" sound effect. It will consist of multiple characteristic frequency points and their harmonics in the range of 300 Hz to 2000 Hz, and its spectral envelope will smoothly decrease in the low frequency band.

[0038] Filter coefficient optimization: The system aims to minimize the actual frequency response of the filter bank. With target spectrum template The objective is to optimize the solution by taking the weighted least squares error between the parameters and the target parameter set of each subband filter. ), based on the optimization solution of the optimal parameter set for each subband filter ( Configure the high-order pulse shaping filter bank; The specific calculation formula is as follows: ; in, The spectral template for the target natural soundscape is denoted by angular frequency variable. The function is stored in the form of the Fourier spectrum amplitude peak envelope vector; : The amplitude spectrum of the actual frequency response of the filter bank; : Psychoacoustic weighting factor, which is the angular frequency The function is set according to the normalization of the equal loudness curve, with higher values ​​in the mid-frequency range and lower values ​​in the low-frequency and high-frequency ranges. The set of feature frequency points of interest in the target soundscape spectrum template, which serves as the constraint frequency range for optimization.

[0039] Among them, psychoacoustic weighting factor You can refer to the equal loudness curves of ISO 226:2003 (e.g., using the 40-phon equal loudness line as a reference) for normalization settings. In the 1-5kHz frequency band where the human ear is most sensitive, use a weight of approximately 1.0, and gradually attenuate to approximately 0.1 in the frequency bands below 100Hz and above 8kHz. The set of feature frequency points of interest in the target soundscape.

[0040] Step S130: Input the pulse event sequence in parallel into the high-order pulse shaping filter bank to generate a sound scene driving signal with the target natural sound scene spectrum characteristics.

[0041] In a preferred embodiment, the pulse event sequence is input in parallel into the output of each sub-band filter of the high-order pulse shaping filter bank, and the outputs of all sub-band filters are summed to obtain the sound scene driving signal. The spectral envelope of this signal has a similarity of more than 0.9 with the spectral envelope of the "tide and waves" sound effect template in the 250Hz to 2000Hz frequency band.

[0042] Step S140: The sound field driving signal is amplified and then used to drive the transducer array, which is then linearly superimposed with the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

[0043] In a preferred embodiment, the soundscape driving signal, after digital-to-analog conversion, is sent to a power amplifier with a rated power of not less than 200 W to drive a horn-type compression drive unit linear array deployed in the viewing platform area 20–50 m away from the device. This array radiates secondary sound waves with the spectral characteristics of the target natural soundscape. Simultaneously, a passive noise reduction preprocessing subsystem reduces the original noise along the propagation path. The secondary sound waves linearly superimpose with the residual noise field after passive noise reduction in the target area to form a synthetic sound field.

[0044] Based on the psychoacoustic masking effect, when the sound pressure level of the sound field frequency band in the synthesized sound field is higher than the sound pressure level of the residual noise, the subjective perception of the human ear changes from noise-dominated to natural sound field-dominated.

[0045] In addition, combined Figure 2 As shown, this embodiment also preferably includes closed-loop adaptive adjustment and scene switching steps: two error microphones are arranged at the target viewing platform to collect the residual noise error signal of the synthesized sound field in real time; a normalized LMS algorithm is adopted, with a preferred step size factor μ=0.01~0.05, using the mean square value of the error signal as the cost function, and the real part of the complex gain parameter of each sub-band filter is finely adjusted online once in each wave cycle, while keeping the imaginary part unchanged, to compensate for changes in the acoustic environment and maintain the spectral alignment relationship. At the same time, the scene matching module calculates the weighted cosine similarity between the 1 / 3 octave band spectrum of the current background sound and the preset scene mode every minute. If the matching degree is lower than the threshold and lasts for more than 5 minutes, the best matching new sound scene template is called from the music library, and the transition to the new filter coefficients is smoothed through linear interpolation in the next wave cycle to achieve seamless switching of the sound scene.

[0046] As shown in Figures 4(a) and 4(b), in this embodiment, with the FPGA (Xilinx Zynq-7000 series) and the aforementioned transducer configuration, the overall power consumption is approximately 0.5% of the device's rated output power, allowing for long-term deployment under self-powered conditions. Full-link simulation results show that, under simulated sea conditions with a meaningful wave height of 1.5 m and a wave period of 8 s, the A-weighted sound pressure level in the target viewing platform area is reduced by approximately 8 dB due to passive noise reduction. Simultaneously, the similarity between the synthesized sound field spectrum and the spectral envelope of the target wave sound effect template reaches over 0.9, achieving a musical transformation from noise to a natural soundscape.

[0047] Based on the above embodiments, the core beneficial effects of the present invention are as follows: (1) In the simulation comparison experiment of simulated sea conditions, compared with the traditional FxLMS algorithm, the present invention significantly reduces the risk of digital coefficient divergence after the occurrence of impulse noise event, and no filter coefficient divergence phenomenon occurs within the tested parameter range, thereby effectively improving the working stability of the system under complex sea conditions.

[0048] (2) Under the same sampling rate and resource constraints, compared with the first-order pulse shaping structure, the higher-order structure adopted in this invention can increase the attenuation slope outside the target frequency band from 20 dB / dec to 40-60 dB / dec, which is beneficial to confine the residual noise energy more concentrated within the target sound scene frequency band and significantly improve the clarity of the sound scene.

[0049] (3) This invention extends the goal of active acoustic reconstruction from the traditional minimization of residual sound pressure level to modulating residual noise into a soundscape signal with preset spectral characteristics. Preliminary subjective evaluation results show that a shift from noise-dominated perception to natural soundscape-dominated perception can be achieved within the target area.

[0050] Example 2: Embodiment 2 of the present invention provides a method for processing low-frequency radiated noise from the underwater structure of an oscillating water column wave energy power generation device.

[0051] System hardware configuration: The underwater acoustic subsystem includes two hydrophones with a sensitivity of -180 dB re 1V / μPa and a frequency response of 20 Hz-10 kHz, deployed at 3m and 10m from the underwater structure of the device, respectively; one omnidirectional transmitting transducer with an operating frequency band of 100-1000 Hz and a maximum emission source level of 185dB re 1μPa@1m, deployed at a water depth of 5m; and two underwater error hydrophones deployed at 10m from the transmitting transducer for collecting underwater error signals.

[0052] Algorithm parameter adjustments: Considering the physical characteristics and propagation environment of underwater low-frequency noise, the core algorithm parameters were optimized as follows: (1) Encoder adjustment: The system sampling rate is reduced to bandpass filter The passband is set to 100Hz-500Hz, which is aligned with the transducer's operating frequency band.

[0053] (2) Soundscape template selection: The music library pre-sets non-biological natural soundscape templates for underwater scenes, such as simulating far-field ocean currents and low-frequency noise of surging waves. Their characteristic frequencies are concentrated in the operating frequency band of the transducer of this system, 100Hz-1000Hz, which can simulate the natural background sound field commonly found in the marine environment.

[0054] (3) Filter bank configuration: The filter bank consists of 8 parallel second-order pulse shaping filters, with the center frequency corresponding to the 8 frequency points with the highest amplitude peak in the selected natural sound scene template.

[0055] (4) Closed-loop control adaptation: Considering that the underwater sound speed is about 1500 m / s, the 10 m distance from the transmitting transducer to the error hydrophone corresponds to an acoustic path delay of about 6.7 ms. In order to compensate for the contamination of the error signal by the underwater multipath effect, the step size factor is finely adjusted online. The value was adjusted to 0.005, and the gain update cycle was extended to 4 wave cycles.

[0056] The specific signal processing flow, filter optimization method, and adaptive switching logic in this embodiment are the same as in Embodiment 1 above. Under the established underwater acoustic propagation and sound field superposition simulation model, simulation results show that, through this embodiment, the underwater low-frequency noise generated by the device can be modulated into a soundscape that is closer to the common natural sound effects in the surrounding marine environment. This is beneficial for improving the subjective acoustic perception of noise in the target water area and reducing the prominence of mechanical noise components.

[0057] Example 3: Figure 5 This is a schematic diagram of the structure of a marine energy device noise control and music conversion system 500 provided in Embodiment 3 of the present invention, as shown below. Figure 5 As shown, the system includes: The passive noise reduction preprocessing and pulse coding module 510 is used to collect the raw noise signal generated by the operation of the marine energy device, and to map the raw noise signal into a pulse event sequence through integration-threshold triggering coding. When the integration value exceeds a preset threshold, a pulse event is generated and the integration is reset. The filter bank configuration module 520 is used to configure a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel, based on a pre-stored spectral template of the target natural sound scene. Each sub-band filter corresponds to a characteristic frequency point in the spectral template and employs... Filter structure, It is an integer not less than 2; The soundscape driving signal generation module 530 is used to input the pulse event sequence in parallel into the high-order pulse shaping filter bank to generate a soundscape driving signal with the target natural soundscape spectral characteristics. The transducer drive module 540 is used to amplify the sound scene drive signal and drive the transducer array to linearly superimpose it with the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

[0058] The marine energy device noise control and music conversion system provided in this embodiment of the invention can execute the marine energy device noise control and music conversion method provided in any of the above embodiments of the invention. It has the corresponding functions and beneficial effects of executing the marine energy device noise control and music conversion method. For detailed process, please refer to the relevant operation of the marine energy device noise control and music conversion method in the foregoing embodiments.

[0059] Example 4: Figure 6This is a schematic diagram of the structure of an electronic device provided in Embodiment 4 of the present invention. The electronic device 10 is intended to represent various forms of digital computers, and may also represent various forms of mobile devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0060] like Figure 6 As shown, the electronic device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded into the RAM 13 from storage unit 18. The RAM 13 can also store various programs and data required for the operation of the electronic device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0061] Multiple components in electronic device 10 are connected to I / O interface 15, including: input unit 16, such as keyboard, mouse, etc.; output unit 17, such as various types of displays, speakers, etc.; storage unit 18, such as disk, optical disk, etc.; and communication unit 19, such as network card, modem, wireless transceiver, etc. Communication unit 19 allows electronic device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0062] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, central processing unit (CPU), graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, digital signal processors (DSPs), and any suitable processor, controller, microcontroller, etc. Processor 11 performs a method for noise control and musicalization of a marine energy device as described above.

[0063] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0064] The above embodiments are merely illustrative examples and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for noise control and music conversion of marine energy devices, characterized in that, include: The raw noise signal generated by the operation of the marine energy device is collected, and the raw noise signal is mapped into a pulse event sequence through integral-threshold trigger coding. When the integral value exceeds a preset threshold, a pulse event is generated and the integral is reset. Based on a pre-stored spectral template of the target natural soundscape, a high-order pulse shaping filter bank consisting of multiple sub-band filters connected in parallel is configured. Each sub-band filter corresponds to a characteristic frequency point in the spectral template and employs... Filter structure, It is an integer not less than 2; The pulse event sequence is input in parallel into the high-order pulse shaping filter bank to generate a sound scene driving signal with the target natural sound scene spectral characteristics; The sound field driving signal is amplified and then drives the transducer array. The transducer array is linearly superimposed on the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

2. The method for noise control and music conversion of marine energy devices according to claim 1, characterized in that, The raw noise signal generated by the operation of the marine energy device is collected, and the raw noise signal is mapped into a pulse event sequence through integral-threshold trigger coding, including: The original noise signal is subjected to weighted bandpass filtering using a weighted window function; The filtered signal is continuously integrated. When the integral value reaches the preset integration threshold, a standard pulse event is generated at the current moment, and the integrator is reset to zero and the next integration cycle begins. All pulse events are accumulated in chronological order to form a pulse event sequence.

3. The method for noise control and music conversion of marine energy devices according to claim 1, characterized in that, The step of configuring a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel, based on a pre-stored spectral template of the target natural soundscape, includes: With the goal of minimizing the weighted least squares error between the actual frequency response of the higher-order pulse shaping filter bank and the spectral template, the complex gain parameter and phase delay parameter of each sub-band filter are optimized and solved. Configure the high-order pulse shaping filter bank according to the complex gain parameters and phase delay parameters obtained from the optimization solution; The weighting factor in the weighted least squares error is a psychoacoustic weighting factor set according to the normalization of the psychoacoustic loudness curve. The weighting factor has a higher value in the mid-frequency range where the human ear is sensitive than in the low-frequency and high-frequency ranges.

4. The method for noise control and musical conversion of marine energy devices according to claim 3, characterized in that, The specific steps for constructing a single subband filter in the higher-order pulse shaping filter bank include: Based on a preset sampling period, a sampling array is constructed. A basic low-pass filter prototype in functional form; The transfer function of the higher-order shaping filter is obtained by performing a power operation of at least two powers on the basic low-pass filter prototype. The transfer function of the higher-order shaping filter is multiplied sequentially by the complex gain parameter and phase delay parameter obtained by optimization to obtain a single subband filter; The complex gain parameter is used to control the amplitude and phase of the output signal of the single subband filter at the corresponding characteristic frequency point, and the phase delay parameter is used to adjust the phase of the output of the subband filter.

5. The method for noise control and musical conversion of marine energy devices according to claim 1, characterized in that, The pulse event sequence is input in parallel into the high-order pulse shaping filter bank to generate a sound scene driving signal with the spectral characteristics of the target natural sound scene, including: The pulse event sequence is simultaneously input into each sub-band filter in the high-order pulse shaping filter bank, and sub-band signals with spectral components at corresponding characteristic frequency points are output respectively. The subband signals output from each subband filter are summed to obtain the soundscape driving signal.

6. The method for noise control and musical conversion of marine energy devices according to claim 1, characterized in that, The sound field driving signal is amplified and then used to drive a transducer array. This array is then linearly superimposed on the residual noise sound field, which has undergone passive noise reduction preprocessing, in the target area to form a synthetic sound field, including: The sound scene driving signal is converted from digital to analog and then sent to a power amplifier for power amplification. The amplified signal drives a transducer array deployed around the target area to radiate secondary sound waves with the spectral characteristics of the target's natural soundscape. The secondary sound wave is linearly acoustically superimposed on the residual noise sound field remaining after passive noise reduction preprocessing in the target area to form a synthetic sound field.

7. The method for noise control and musical conversion of marine energy devices according to claim 6, characterized in that, After the synthesized sound field is formed, a closed-loop adaptive adjustment step is also included: Collect the residual noise error signal of the synthesized sound field in the target area; The normalized LMS algorithm is adopted, with the mean square value of the residual noise error signal as the cost function. In each wave cycle, the real part of the complex gain parameter of each sub-band filter in the high-order pulse shaping filter bank is finely adjusted online once, while keeping the imaginary part of the complex gain parameter unchanged, so as to compensate for changes in the acoustic environment and maintain the spectral alignment relationship.

8. The method for noise control and musical conversion of marine energy devices according to claim 1, characterized in that, The method also includes scene matching and smooth switching steps: Real-time calculation of the weighted cosine similarity between the current background noise frequency band spectrum of the target area and the preset scene mode; When the weighted cosine similarity is lower than a preset configurable threshold and the duration exceeds a preset duration, the spectrum template of the new target natural soundscape that best matches the current background sound is retrieved from the music library. Within one wave cycle, the complex gain parameters of the high-order pulse shaping filter bank are smoothly transitioned from their current values ​​to the optimized values ​​of the corresponding new spectral template through linear interpolation, thus completing the seamless switching of the sound scene.

9. The method for noise control and musical conversion of marine energy devices according to claim 1, characterized in that, The passive noise reduction preprocessing includes: A resistive silencer is installed at the turbine exhaust port of the marine energy device. The resistive silencer uses a salt spray resistant stainless steel shell and basalt fiber sound-absorbing material. A micro-perforated plate sound-absorbing structure is laid on the gas chamber wall.

10. A noise control and music conversion system for a marine energy device, characterized in that, The system is used to perform the marine energy device noise control and music conversion method according to any one of claims 1 to 9, the system comprising: The passive noise reduction preprocessing and pulse coding module is used to collect the raw noise signal generated by the operation of the marine energy device, and to map the raw noise signal into a pulse event sequence through integration-threshold triggering coding. When the integration value exceeds a preset threshold, a pulse event is generated and the integration is reset. The filter bank configuration module is used to configure a high-order pulse shaping filter bank composed of multiple sub-band filters connected in parallel, based on a pre-stored spectral template of the target natural sound scene. Each sub-band filter corresponds to a characteristic frequency point in the spectral template and employs... Filter structure, It is an integer not less than 2; The soundscape driving signal generation module is used to input the pulse event sequence in parallel into the high-order pulse shaping filter bank to generate a soundscape driving signal with the target natural soundscape spectral characteristics. The transducer driving module is used to amplify the sound scene driving signal and drive the transducer array to linearly superimpose it with the residual noise sound field after passive noise reduction preprocessing in the target area to form a synthetic sound field.

Images