Multi-channel ultrasonic signal parallel processing method and system

Abstract

The invention provides a multichannel ultrasonic signal parallel processing method and system, which can be applied to the technical field of high-frequency sound signal positioning detection. The method comprises the following steps: respectively carrying out signal modulation processing on ultrasonic signals of a plurality of channels to obtain a pulse density modulation signal of each channel; decoding the pulse density modulation signals of the plurality of channels to obtain pulse code modulation signals; adjusting the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; and carrying out positioning processing on the ultrasonic output signal based on a beam forming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

Description

Technical Field

[0001] The present invention relates to the technical field of high-frequency acoustic signal positioning detection, and more specifically, to a multi-channel ultrasonic signal parallel processing method and system. Background Art

[0002] Ultrasonic signals refer to sound waves with frequencies higher than the human hearing range (above 20kHz). Due to its unique physical properties, ultrasound plays an important role in the fields of ocean surveying, pipeline transportation and power grid maintenance.

[0003] The sampling rate of traditional sound acquisition systems is usually designed to be within the audible sound range (such as 44.1kHz or 48kHz). In ultrasonic signal processing, there are problems such as insufficient sampling rate, bandwidth limitation, poor parallel processing capability, weak anti-interference capability, and limited data processing capability. It cannot meet the needs of ultrasonic signal acquisition and processing with high frequency, high precision, and high real-time requirements. The sampling rate of existing ultrasonic signal acquisition systems is low and cannot meet the needs of high-frequency ultrasonic signal acquisition, resulting in distortion or loss of high-frequency signals. In addition, most existing ultrasonic signal acquisition systems use serial processing and cannot process multi-channel signals at the same time, resulting in slow processing speed and data delay. Summary of the invention

[0004] In view of this, the present invention provides a multi-channel ultrasonic signal parallel processing method and system.

[0005] One aspect of the present invention provides a multi-channel ultrasonic signal parallel processing method, which includes: performing signal modulation processing on ultrasonic signals of multiple channels respectively to obtain a pulse density modulation signal of each channel; decoding processing on the pulse density modulation signals of multiple channels to obtain a pulse code modulation signal; adjusting the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; and positioning processing on the ultrasonic output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

[0006] According to an embodiment of the present invention, the above-mentioned signal modulation processing is performed on the ultrasonic signals of multiple channels respectively to obtain a pulse density modulated signal of each channel, including: performing sound-to-electric conversion processing on the ultrasonic signals of the above-mentioned multiple channels respectively to obtain an analog electrical signal of each channel; and using a modulator to perform signal modulation processing on the analog electrical signal of each channel to obtain a pulse density modulated signal of each channel.

[0007] According to an embodiment of the present invention, the pulse density modulation signals of multiple channels are decoded to obtain pulse code modulation signals, including: down-sampling filtering processing is performed on the pulse density modulation signals of the multiple channels to obtain a first filtered signal; low-pass filtering processing is performed on the first filtered signal to obtain a second filtered signal; convolution filtering processing is performed on the second filtered signal to obtain the pulse code modulation signal.

[0008] According to an embodiment of the present invention, the above-mentioned positioning processing of the ultrasonic output signal based on the beamforming positioning algorithm to obtain the visual positioning information of the ultrasonic signal includes: positioning processing of the ultrasonic output signal based on the beamforming positioning algorithm to obtain the sound source position of the ultrasonic output signal; superimposing the sound source position of the ultrasonic output signal on a visual image to obtain the visual positioning information of the ultrasonic output signal.

[0009] Another aspect of the present invention provides a multi-channel ultrasonic signal parallel processing system, which is applicable to the above-mentioned multi-channel ultrasonic signal parallel processing method, wherein the multi-channel ultrasonic signal parallel processing system includes a multi-element microphone array board, a field programmable gate array and a host computer, wherein the multi-element microphone array board is connected to the field programmable gate array through a board-to-board connector, and the multi-element microphone array board is configured to collect ultrasonic signals of multiple channels, and perform signal modulation processing on the ultrasonic signals of the multiple channels respectively to obtain a pulse density modulation signal of each channel; wherein the field programmable gate array is configured to decode the pulse density modulation signals of the multiple channels to obtain a pulse code modulation signal, and adjust the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; wherein the host computer is connected to the field programmable gate array through an Ethernet cable, and the host computer is configured to perform positioning processing on the ultrasonic output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

[0010] According to an embodiment of the present invention, the field programmable gate array includes a decoding module, a first-in-first-out cache module and an Ethernet module, wherein the decoding module is configured to decode the pulse density modulation signals of the multiple channels to obtain the pulse code modulation signals; the first-in-first-out cache module is configured to cache the pulse code modulation signals and adjust the data bit width of the pulse code modulation signals to obtain the ultrasonic output signals; the Ethernet module is configured to package the ultrasonic output signals in channel order and output the ultrasonic output signals through the Ethernet line.

[0011] According to an embodiment of the present invention, the field programmable gate array further comprises a clock module, wherein the clock module is configured to provide clock signals to the decoding module, the first-in-first-out buffer module and the Ethernet module respectively.

[0012] According to an embodiment of the present invention, the clock module is further configured to provide a sampling clock signal to the multi-element microphone array board, so that the multi-element microphone array board operates in an ultrasonic mode.

[0013] According to an embodiment of the present invention, the above-mentioned decoding module includes a cascaded integrator comb filter, a half-band filter and a finite impulse response filter, wherein the above-mentioned cascaded integrator comb filter is used to perform downsampling filtering processing on the pulse density modulation signals of the above-mentioned multiple channels to obtain a first filtered signal; the above-mentioned half-band filter is used to perform low-pass filtering processing on the above-mentioned first filtered signal to obtain a second filtered signal; the above-mentioned finite impulse response filter is used to perform convolution filtering processing on the above-mentioned second filtered signal to obtain the above-mentioned pulse code modulation signal.

[0014] According to an embodiment of the present invention, the above-mentioned first-in-first-out cache module includes a first first-in-first-out unit, a second first-in-first-out unit, and a third first-in-first-out unit, wherein the above-mentioned first first-in-first-out unit is used to perform group cache processing on the above-mentioned pulse code modulation signal, and perform a first bit width adjustment on the above-mentioned pulse code modulation signal to obtain a first intermediate pulse code modulation signal; the above-mentioned second first-in-first-out unit is used to arrange the above-mentioned first intermediate pulse code modulation signal according to the channel order, and perform a second bit width adjustment on the above-mentioned first intermediate pulse code modulation signal to obtain a second intermediate pulse code modulation signal; the above-mentioned third first-in-first-out unit is used to perform a third bit width adjustment on the above-mentioned second intermediate pulse code modulation signal to obtain the above-mentioned ultrasonic output signal.

[0015] According to the multi-channel ultrasonic signal parallel processing method provided by an embodiment of the present invention, the pulse density modulated signal is converted into a pulse code modulated signal by performing pulse density modulation and parallel decoding on the multi-channel ultrasonic signal, thereby realizing the synchronous acquisition of multi-channel high-frequency ultrasonic signals, parallel rapid processing and precise positioning of the sound source. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0017] Figure 1 A flow chart of a method for parallel processing of multi-channel ultrasound signals according to an embodiment of the present invention is shown.

[0018] Figure 2 A schematic structural diagram of a multi-channel ultrasonic signal parallel processing system according to an embodiment of the present invention is shown.

[0019] Figure 3 A data flow diagram of a multi-channel ultrasound signal parallel processing system according to a specific embodiment of the present invention is shown.

[0020] Figure 4 A structural schematic diagram of a decoding module according to a specific embodiment of the present invention is shown.

[0021] Figure 5 A block diagram of a multi-channel ultrasound signal parallel processing device according to an embodiment of the present invention is shown.

[0022] Figure 6 A block diagram of an electronic device for a multi-channel ultrasound signal parallel processing method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0023] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0024] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0025] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0026] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0027] Ultrasonic signals refer to sound waves with frequencies higher than the human hearing range (above 20kHz). Due to its unique physical properties, ultrasound plays an important role in many fields. For example, in the field of marine surveying, ultrasonic signals can be used to obtain information such as marine topography; in resource pipeline transportation and power grid maintenance scenarios, ultrasonic signals can be used to detect the location of the sound source and realize the visual positioning of the leakage point. Therefore, the collection and processing of ultrasonic signals are of great significance.

[0028] Traditional sound collection systems have problems in ultrasonic signal processing, such as insufficient sampling rate, bandwidth limitation, poor parallel processing capability, weak anti-interference ability, and limited data processing capability. They cannot meet the needs of ultrasonic signal collection and processing with high frequency, high precision, and real-time requirements.

[0029] For example, the sampling rate of traditional sound acquisition systems is usually designed to be in the audible sound range (such as 44.1kHz or 48kHz), which cannot meet the high sampling rate requirements of ultrasonic signals and cannot accurately capture high-frequency ultrasonic signals, resulting in signal distortion or loss. In addition, the hardware design of traditional sound acquisition systems (such as microphones, amplifiers, and ADCs) has limited bandwidth and usually only supports the audible sound range, which cannot effectively collect and process high-frequency ultrasonic signals. High-frequency signals are easily attenuated or distorted during transmission and processing.

[0030] At present, the sampling rate of existing ultrasonic signal acquisition systems is low and cannot meet the acquisition requirements of high-frequency ultrasonic signals, resulting in distortion or loss of high-frequency signals and inability to accurately restore ultrasonic signals. In addition, most existing ultrasonic signal acquisition systems use serial processing and cannot process multi-channel signals at the same time, resulting in slow processing speed and data delay.

[0031] Based on the above problems, an embodiment of the present invention provides a method for parallel processing of multi-channel ultrasonic signals. By performing pulse density modulation and parallel decoding on the multi-channel ultrasonic signals, the pulse density modulated signals are converted into pulse code modulated signals, thereby realizing synchronous acquisition of multi-channel high-frequency ultrasonic signals, parallel rapid processing and precise positioning of sound sources.

[0032] Specifically, an embodiment of the present invention provides a method for parallel processing of multi-channel ultrasonic signals, including: performing signal modulation processing on ultrasonic signals of multiple channels respectively to obtain a pulse density modulation signal of each channel; decoding processing on the pulse density modulation signals of multiple channels to obtain a pulse code modulation signal; adjusting the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; and positioning processing on the ultrasonic output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

[0033] It should be noted that the multi-channel ultrasonic signal parallel processing method and system determined in the embodiment of the present invention can be used in the field of high-frequency acoustic signal positioning detection technology. The multi-channel ultrasonic signal parallel processing method and system determined in the embodiment of the present invention can also be used in any field other than the technical field, such as the field of ultrasonic signal processing technology. The application field of the multi-channel ultrasonic signal parallel processing method and system determined in the embodiment of the present invention is not limited.

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0035] Figure 1 A flow chart of a method for parallel processing of multi-channel ultrasound signals according to an embodiment of the present invention is shown.

[0036] like Figure 1 As shown, the method includes operations S101 to S104.

[0037] In operation S101 , signal modulation processing is performed on ultrasound signals of multiple channels respectively to obtain a pulse density modulation signal of each channel.

[0038] In operation S102, the pulse density modulation signals of the plurality of channels are decoded to obtain pulse code modulation signals.

[0039] In operation S103, the bit width of the pulse code modulation signal is adjusted to obtain an ultrasonic output signal.

[0040] In operation S104, positioning processing is performed on the ultrasound output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasound output signal.

[0041] According to an embodiment of the present invention, ultrasonic signals in different directions can be synchronously collected by a sensor array, and the frequency is usually higher than 20 kHz. The sensor array can be composed of multiple MEMS digital microphones.

[0042] According to a specific embodiment of the present invention, a micro-electromechanical system (MEMS) digital microphone can perform pulse density modulation (PDM) on the collected external sound signal to obtain a pulse density modulation signal. Each micro-electromechanical system (MEMS) digital microphone outputs a pulse density modulation signal of one channel.

[0043] According to an embodiment of the present invention, a pulse density modulation signal can represent amplitude information of a signal through pulse density.

[0044] According to the embodiment of the present invention, since the pulse density modulation signal is a single-bit, high-sampling rate digital signal, and its data format is a continuous sequence of 0 and 1, the pulse density modulation signal can be decoded in parallel to convert the single-bit, high-sampling rate pulse density modulation signal into a multi-bit, low-sampling rate pulse code modulation signal. For example, a 1-bit, 3.125MHz high-sampling data stream can be converted into a 16-bit, 48kHz data stream.

[0045] According to an embodiment of the present invention, the pulse code modulation signal of each channel is cached in a memory, and the bit width of the pulse code modulation signal is adjusted. For example, the amount of data in one frame collected by 64 microphones is 2048 bits, and the 2048 bits are adjusted to be output once every 8 bits to meet the transmission requirements and improve the transmission efficiency.

[0046] According to an embodiment of the present invention, based on a beamforming algorithm, the phase difference or time difference of ultrasonic output signals of multiple channels is calculated to determine the position of the sound source, and visual positioning information is obtained based on the position of the sound source.

[0047] Based on this, an embodiment of the present invention supports the acquisition of high-frequency ultrasonic signals with a frequency range of up to 80kHz. In addition, the present invention converts pulse density modulated signals into pulse code modulated signals by performing pulse density modulation and parallel decoding on multi-channel ultrasonic signals, thereby realizing synchronous acquisition of multi-channel ultrasonic signals, parallel rapid processing and precise positioning of sound sources.

[0048] According to an embodiment of the present invention, signal modulation processing is performed on ultrasonic signals of multiple channels respectively to obtain a pulse density modulated signal of each channel, including: performing acoustic-to-electric conversion processing on ultrasonic signals of multiple channels respectively to obtain an analog electrical signal of each channel; and performing signal modulation processing on the analog electrical signal of each channel to obtain a pulse density modulated signal of each channel.

[0049] According to an embodiment of the present invention, an ultrasonic sensor array with multiple channels is used to receive ultrasonic signals from different directions, and the ultrasonic sensor of each channel converts the received external ultrasonic signal into an analog electrical signal through a change in capacitance. Each sensor outputs an analog electrical signal, and the signal amplitude is proportional to the strength of the ultrasonic signal. The frequency range of the analog electrical signal is consistent with that of the ultrasonic signal.

[0050] According to an embodiment of the present invention, a modulator such as a Sigma-Delta Modulator is used to perform high-frequency signal processing on the analog electrical signal of each channel, and the amplitude information of the analog electrical signal is converted into density information, thereby obtaining a pulse density modulation signal of each channel. Among them, the pulse density modulation signal can be composed of pulses of multiple densities, and the number of pulses varies with the amplitude of the analog electrical signal. Specifically, the higher the amplitude of the analog electrical signal, the more pulses are generated per unit time; the lower the amplitude of the analog electrical signal, the fewer the number of pulses.

[0051] According to a specific embodiment of the present invention, using a modulator to perform signal processing on the analog electrical signal of each channel may include: oversampling, noise shaping, and signal quantization of the analog electrical signal of each channel to obtain a pulse density modulated signal. For example, the analog electrical signal is sampled at a sampling rate much higher than the target signal frequency (such as 3.125MHz), and then the quantization noise is pushed to the high frequency region through a feedback loop, and finally the sampled signal is quantized into a single-bit pulse density modulated signal.

[0052] Based on this, the embodiments of the present invention respectively perform pulse density modulation on the collected ultrasonic signals of multiple channels, and transmit information by changing the density of pulses, so as to achieve a higher data transmission rate within a limited bandwidth. In addition, in a complex electromagnetic environment, by adopting pulse density modulation and demodulation technology, it is possible to achieve high-fidelity restoration of the original ultrasonic signal, ensure stable transmission of the signal, and reduce the risk of signal distortion or loss due to interference.

[0053] According to an embodiment of the present invention, pulse density modulation signals of multiple channels are decoded to obtain pulse code modulation signals, including: downsampling and filtering the pulse density modulation signals of multiple channels to obtain a first filtered signal; low-pass filtering the first filtered signal to obtain a second filtered signal; and convolution filtering the second filtered signal to obtain a pulse code modulation signal.

[0054] According to an embodiment of the present invention, based on the pulse density modulation signals of multiple channels output by the sensor array, multiple digital filtering units may be used to decode the pulse density modulation signals in parallel to obtain pulse code modulation signals.

[0055] In a specific embodiment of the present invention, the pulse density modulation signal of each channel can be subjected to 8-fold decimation, that is, one of every eight sampling points of the pulse density modulation signal is retained as a new sampling point, and filtering is performed to smooth the signal to obtain a first filtered signal, wherein the sampling rate of the first filtered signal has been reduced to 1 / 8 of the original pulse density modulation signal. The first filtered signal is subjected to low-pass filtering to filter out the high-frequency components in the first filtered signal to obtain a second filtered signal to reduce high-frequency noise and aliasing effects. The second filtered signal is subjected to convolution filtering so that the output pulse code modulation signal maintains the smoothness of the passband and stopband on the basis of satisfying the amplitude-frequency response characteristics.

[0056] According to an embodiment of the present invention, the pulse density modulation signal of each channel is converted into a multi-bit pulse code modulation signal after being extracted and filtered.

[0057] Based on this, the embodiments of the present invention perform efficient downsampling and decoding processing on the pulse density modulation signal through multi-stage filtering, thereby achieving high-quality conversion of multi-channel ultrasonic signals and providing a reliable data basis for subsequent sound source localization and visualization.

[0058] According to an embodiment of the present invention, positioning processing is performed on the ultrasonic output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic signal, including: positioning processing is performed on the ultrasonic output signal based on a beamforming positioning algorithm to obtain the sound source position of the ultrasonic output signal; and the sound source position of the ultrasonic output signal is superimposed on a visual image to obtain visual positioning information of the ultrasonic output signal.

[0059] According to an embodiment of the present invention, a beamforming algorithm is used to calculate the phase difference or time difference of the ultrasonic output signals between multiple channels to obtain the phase information of the ultrasonic output signals. The position of the sound source is determined based on the phase information of the multiple ultrasonic output signals and the geometric structure of the sensor array, such as the position coordinates of the microphone.

[0060] According to a specific embodiment of the present invention, for each scanning direction, the time delay from the sound source to each microphone can be calculated. Based on the calculated time delay and the output value of the beamforming, the signal energy of each scanning direction is calculated. Among all scanning directions, the direction with the largest energy is found, and this direction can be used as the position of the sound source.

[0061] According to another specific embodiment of the present invention, a short-time Fourier transform (STFT) may be performed on the ultrasonic output signal to convert the ultrasonic output signal into the frequency domain, and a cross-power spectrum may be calculated. The beamforming power at each position is calculated based on the cross-power spectrum, and the point with the maximum power is selected as the sound source position.

[0062] According to an embodiment of the present invention, after determining the location information of the sound source, a visual image related to the target area, such as a map, equipment layout diagram or medical image, is obtained, and the calculated sound source information is converted into spatial coordinates on the visual image and mapped to the visual image to generate visual positioning information for users to intuitively view and interact with.

[0063] Figure 2 A schematic structural diagram of a multi-channel ultrasonic signal parallel processing system according to an embodiment of the present invention is shown.

[0064] like Figure 2 As shown, the system includes a multi-element microphone array board 1, a field programmable gate array 2 and a host computer 3.

[0065] like Figure 2 As shown, the multi-element microphone array board 1 is connected to the field programmable gate array 2 through a board-to-board connector, and the field programmable gate array 2 is connected to the host computer 3 through an Ethernet cable.

[0066] According to an embodiment of the present invention, the multi-element microphone array board 1 is used to collect external ultrasonic signals, each microphone converts the collected ultrasonic signals into analog electrical signals, modulates the analog electrical signals into pulse density modulation (PDM) signals through a modulator, and then outputs the PDM signals to the field programmable gate array 2 through a board-to-board connector. The multi-element microphone array board 1 may include 64 MEMS digital microphones.

[0067] According to an embodiment of the present invention, the field programmable gate array 2 performs parallel decoding processing on the pulse density modulation (PDM) signals of multiple channels to generate a pulse code modulation (PCM) signal. The pulse code modulation (PCM) signal is adjusted in bit width to generate an ultrasonic output signal, and then the ultrasonic output signal is output to the host computer 3 via an Ethernet cable.

[0068] According to an embodiment of the present invention, in response to receiving the ultrasonic output signal transmitted by the field programmable gate array 2, the host computer 3 performs positioning processing on the ultrasonic output signal based on the beamforming positioning algorithm to generate visual positioning information.

[0069] Figure 3 A data flow diagram of a multi-channel ultrasound signal parallel processing system according to a specific embodiment of the present invention is shown.

[0070] like Figure 3As shown in the figure, the 64-element microphone array is the front end of the entire system, which collects ultrasonic signals from different directions, modulates the ultrasonic signals into PDM format data, and transmits them to the field programmable gate array (FPGA) through 64 channels including MIC1~MIC64. Among them, the 64-element microphone array includes 64 MEMS digital microphones, capacitors and board-to-board connectors.

[0071] like Figure 3 As shown, the field programmable gate array (FPGA) includes a decoding module, a first-in first-out buffer module (FIFO buffer module) and an Ethernet module. Among them, the decoding module is used to receive the PDM format data output by the 64-element microphone array, and decode the PDM format data of 64 channels in parallel and convert them into usable PCM format data. The FIFO buffer module is used to cache the PCM format data and adjust the bit width of the PCM format data. The Ethernet module is used to package the PCM format data after the bit width adjustment, and transmit the PCM format data packet to the host computer through the Ethernet line.

[0072] In this specific embodiment, the field programmable gate array (FPGA) also provides a 3.3V voltage for the 64-element microphone array for use by the 64-element microphone array.

[0073] like Figure 3 As shown, the field programmable gate array also includes a clock module. In this specific embodiment, the clock module provides 8 clock lines CLK1-CLK8 for the 64-element microphone array, each clock line is multiplexed for 8 MEMS microphones, and provides a 3.125Mhz sampling clock signal for the MEMS microphone, so that the MEMS microphone works in ultrasonic mode and can sample 0-80Khz sound signals.

[0074] In this specific embodiment, the clock module also provides a 50Mhz working clock signal for the decoding module, provides 50Mhz and 125Mhz clocks for the FIFO buffer module, and provides a 125Mhz working clock for the Ethernet module. When the FIFO buffer module receives data transmitted by the decoding module, it uses a 50Mhz clock that is consistent with the working clock of the decoding module, and when the FIFO buffer module outputs data, it uses a 125Mhz clock that is consistent with the Ethernet module clock.

[0075] like Figure 3 As shown, the host computer receives the PCM format data packets sent by the Ethernet module in the field programmable gate array through the Ethernet line, stores and integrates the PCM format data packets, and performs positioning processing on the PCM format data packets based on the beamforming positioning algorithm to obtain visual positioning information.

[0076] In this specific embodiment, since each first-in-first-out unit supports up to 8 times bit width modulation, and the maximum input bit width of each unit is 1024 bits, if the 2048 bits of 64 channels are reduced to an 8-bit bit width, the first-in-first-out cache module (FIFO cache module) can be composed of three levels of first-in-first-out units in series. Among them, the first level is composed of two first-in-first-out sub-units, each of which caches the 1024-bit pulse code modulation signal and adjusts the 1024 bits to 512 bits to obtain a first intermediate pulse code modulation signal. The second-level first-in-first-out unit is used to arrange the first intermediate pulse code modulation signal according to the channel order, and adjust the 512 bits to a 64-bit bit width to obtain a second intermediate pulse code modulation signal. The third first-in-first-out unit is used to adjust the data bit width of the intermediate pulse code modulation signal again, so that the output ultrasonic output signal meets the 8-bit transmission requirement of the Ethernet module.

[0077] Figure 4 A schematic diagram of the structure of a decoding module according to a specific embodiment of the present invention is shown.

[0078] like Figure 4 As shown, the decoding module includes a CIC decimation filter (cascaded integrator comb filter), a half-band filter and a boost FIR filter (boost finite impulse response filter).

[0079] In this specific embodiment, the CIC extraction filter is used to perform 8-fold extraction processing on the pulse density modulation signal (PDM format data) transmitted by 64 channels respectively, that is, one sampling point out of every 8 sampling points of the pulse density modulation signal is retained as a new sampling point, so that the number of sampling points of the output signal of each channel is reduced to 1 / 8 of the original signal, thereby obtaining a first filtered signal.

[0080] In this specific embodiment, the half-band filter is used to perform a 2-fold decimation process on the first filtered signal of the 64-channel, and simultaneously perform a low-pass filtering process to obtain a second filtered signal. Since the frequency response of the half-band filter has a steep transition band between the passband and the stopband, and the ripples of the passband and the stopband are very small, the aliasing effect in the decimation process is reduced, and the sampling rate is further reduced.

[0081] In this specific embodiment, the boost FIR filter is used to perform convolution filtering on the second filtered signal. Since the frequency response of the CIC decimation filter has ripples in the passband and stopband, the boost FIR filter can be used to adjust the spectrum of the signal and further smooth the signal to compensate for the passband and stopband unevenness introduced by the CIC decimation filter, so that the output pulse code modulation (PCM) signal is closer to the signal characteristics of the ideal pulse code modulation signal.

[0082] Based on this, the decoding module completes 16 times decimation and filtering through cascaded CIC decimation filters, half-band filters and boost FIR filters, achieving efficient and high-quality conversion from PDM signals to PCM signals. This process not only reduces the data rate, but also optimizes the spectral characteristics of the signal, providing a solid foundation for subsequent audio processing.

[0083] According to a specific embodiment of the present invention, in the scenario of verifying a multi-channel ultrasonic signal parallel processing system, a sound device is placed in front of a multi-element microphone array board, and it is set to emit sound waves in the ultrasonic frequency band as the input signal of the system, and the integrated logic analyzer function in the host computer is used to capture the signal inside the FPGA to observe whether the pulse density modulation signal is correctly converted into a pulse code modulation signal, and verify whether the PCM data is correctly cached and packaged. By comparing the captured signal with the expected signal, it can be verified whether the signal processing capability of the system meets the design requirements. The waveform and frequency information collected by each microphone are displayed in the host computer, so that the operating object can check the microphone that he wants to view, and compare the frequency domain information and time domain information of the signal collected by it, so as to compare it with the sound source information set by the sound generator.

[0084] Based on this, the embodiment of the present invention adopts a parallel design concept to simultaneously modulate and demodulate 64 channels of ultrasonic data, which not only improves the efficiency of data acquisition and display, shortens the overall processing time, but also realizes the rapid acquisition of high-frequency signals with a frequency range of up to 80kHz. In addition, the embodiment of the present invention configures the multi-element microphone array board, the field programmable gate array, and the host computer, so that the multi-channel ultrasonic signal parallel processing system has efficient parallel processing capabilities, high-speed and high-quality data acquisition and display, and the integrity and flexibility of the hardware and software systems, thereby realizing the visual positioning of the sound source, and providing a solution for sound source positioning and troubleshooting in complex environments.

[0085] Figure 5 A block diagram of a multi-channel ultrasound signal parallel processing device according to an embodiment of the present invention is shown.

[0086] like Figure 5 As shown, the multi-channel ultrasonic signal parallel processing device includes a signal modulation module 510 , a decoding module 520 , an adjustment module 530 , and a positioning module 540 .

[0087] The signal modulation module 510 is used to perform signal modulation processing on the ultrasonic signals of multiple channels respectively to obtain a pulse density modulation signal of each channel.

[0088] The decoding module 520 is used to decode the pulse density modulation signals of multiple channels to obtain pulse code modulation signals.

[0089] The adjustment module 530 is used to adjust the bit width of the pulse code modulation signal to obtain an ultrasonic output signal.

[0090] The positioning module 540 is used to perform positioning processing on the ultrasonic output signal based on the beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

[0091] According to an embodiment of the present invention, the signal modulation module 510 includes a conversion unit and a modulation unit.

[0092] The conversion unit is used to perform acoustic-to-electric conversion processing on ultrasonic signals of multiple channels respectively to obtain analog electrical signals of each channel.

[0093] The modulation unit is used to perform signal modulation processing on the analog electrical signal of each channel using a modulator to obtain a pulse density modulation signal of each channel.

[0094] According to an embodiment of the present invention, the decoding module 520 includes a first filtering unit, a second filtering unit, and a third filtering unit.

[0095] The first filtering unit is used to perform downsampling filtering on the pulse density modulation signal to obtain a first filtered signal.

[0096] The second filtering unit is used to perform low-pass filtering on the first filtered signal to obtain a second filtered signal.

[0097] The third filtering unit is used to perform convolution filtering on the second filtered signal to obtain a pulse code modulation signal.

[0098] According to the embodiment of the present invention, the positioning module 540 includes a positioning unit and a determining unit.

[0099] The positioning unit is used to perform positioning processing on the ultrasonic output signal based on the beamforming algorithm to obtain the sound source position of the ultrasonic output signal.

[0100] The determination unit is used to superimpose the sound source position of the ultrasonic output signal on the visual image to obtain the visual positioning information of the ultrasonic output signal.

[0101] According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits, or at least part of the functions of any one of them can be implemented in one module. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be split into multiple modules for implementation. According to the embodiments of the present invention, any one or more of the modules, submodules, units, and subunits can be at least partially implemented as hardware circuits, such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), systems on chips, systems on substrates, systems on packages, application specific integrated circuits (ASICs), or can be implemented by hardware or firmware in any other reasonable way of integrating or packaging the circuit, or by any one of the three implementation methods of software, hardware, and firmware, or by a proper combination of any of them. Alternatively, according to the embodiments of the present invention, one or more of the modules, submodules, units, and subunits can be at least partially implemented as computer program modules, and when the computer program modules are run, the corresponding functions can be executed.

[0102] For example, any multiple of the signal modulation module 510, the decoding module 520, the adjustment module 530, and the positioning module 540 can be combined in one module / unit / sub-unit for implementation, or any one of the modules / units / sub-units can be split into multiple modules / units / sub-units. Alternatively, at least part of the functions of one or more of these modules / units / sub-units can be combined with at least part of the functions of other modules / units / sub-units and implemented in one module / unit / sub-unit. According to an embodiment of the present invention, at least one of the signal modulation module 510, the decoding module 520, the adjustment module 530, and the positioning module 540 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware, and firmware or in a suitable combination of any of them. Alternatively, at least one of the signal modulation module 510, the decoding module 520, the adjustment module 530, and the positioning module 540 may be at least partially implemented as a computer program module, and when the computer program module is executed, the corresponding function may be performed.

[0103] It should be noted that the multi-channel ultrasonic signal parallel processing device part in the embodiment of the present invention corresponds to the multi-channel ultrasonic signal parallel processing method part in the embodiment of the present invention. The description of the multi-channel ultrasonic signal parallel processing device specifically refers to the multi-channel ultrasonic signal parallel processing method part, which will not be repeated here.

[0104] Figure 6 A block diagram of an electronic device for a multi-channel ultrasound signal parallel processing method according to an embodiment of the present invention is shown. Figure 6 The electronic device shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present invention.

[0105] like Figure 6 As shown, the electronic device according to an embodiment of the present invention includes a processor 601, which can perform various appropriate actions and processes according to the program stored in the read-only memory ROM 602 or the program loaded from the storage part 608 to the random access memory RAM 603. The processor 601 may include, for example, a general-purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special-purpose microprocessor (for example, an application-specific integrated circuit (ASIC)), etc. The processor 601 may also include an on-board memory for caching purposes. The processor 601 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0106] In RAM 603, various programs and data required for the operation of the electronic device are stored. The processor 601, ROM 602 and RAM 603 are connected to each other via a bus 604. The processor 601 performs various operations of the method flow according to the embodiment of the present invention by executing the programs in ROM 602 and / or RAM 603. It should be noted that the program can also be stored in one or more memories other than ROM 602 and RAM 603. The processor 601 can also perform various operations of the method flow according to the embodiment of the present invention by executing the programs stored in the one or more memories.

[0107] According to an embodiment of the present invention, the electronic device may further include an input / output (I / O) interface 605, which is also connected to the bus 604. The electronic device may further include one or more of the following components connected to the input / output (I / O) interface 605: an input portion 606 including a keyboard, a mouse, etc.; an output portion 607 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage portion 608 including a hard disk, etc.; and a communication portion 609 including a network interface card such as a LAN card, a modem, etc. The communication portion 609 performs communication processing via a network such as the Internet. A drive 610 is also connected to the input / output (I / O) interface 605 as needed. A removable medium 611, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 610 as needed, so that a computer program read therefrom is installed into the storage portion 608 as needed.

[0108] According to an embodiment of the present invention, the method flow according to an embodiment of the present invention can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 609, and / or installed from the removable medium 611. When the computer program is executed by the processor 601, the above-mentioned functions defined in the system of the embodiment of the present invention are executed. According to an embodiment of the present invention, the system, equipment, device, module, unit, etc. described above can be implemented by a computer program module.

[0109] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiment; or may exist independently without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiment of the present invention is implemented.

[0110] According to an embodiment of the present invention, the computer-readable storage medium may be a non-volatile computer-readable storage medium. For example, it may include but is not limited to: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, an apparatus or a device.

[0111] For example, according to an embodiment of the present invention, the computer-readable storage medium may include the ROM 602 and / or the RAM 603 described above and / or one or more memories other than the ROM 602 and the RAM 603 .

[0112] An embodiment of the present invention also includes a computer program product, which includes a computer program, which contains program code for executing the method provided by the embodiment of the present invention. When the computer program product runs on an electronic device, the program code is used to enable the electronic device to implement the multi-channel ultrasonic signal parallel processing method provided by the embodiment of the present invention.

[0113] When the computer program is executed by the processor 601, the above functions defined in the system / device of the embodiment of the present invention are executed. According to the embodiment of the present invention, the system, device, module, unit, etc. described above can be implemented by a computer program module.

[0114] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices, magnetic storage devices, etc. In another embodiment, the computer program may also be transmitted and distributed in the form of signals on a network medium, and downloaded and installed through the communication part 609, and / or installed from a removable medium 611. The program code contained in the computer program may be transmitted using any appropriate network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0115] According to an embodiment of the present invention, the program code for executing the computer program provided by the embodiment of the present invention can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level process and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, Java, C++, python, "C" language or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, partially on the remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., using an Internet service provider to connect through the Internet).

[0116] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram may represent a module, a program segment, or a part of a code, and the above-mentioned module, program segment, or a part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box may also occur in an order different from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions. It can be understood by those skilled in the art that the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways, even if such a combination or combination is not explicitly recorded in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features recorded in the various embodiments of the present invention can be combined and / or combined in various ways. All these combinations and / or combinations fall within the scope of the present invention.

[0117] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A multi-channel ultrasonic signal parallel processing method, characterized in that: The multi-channel ultrasonic signal parallel processing method comprises: Performing signal modulation processing on ultrasonic signals of multiple channels respectively to obtain a pulse density modulation signal of each channel, wherein the ultrasonic signals of the multiple channels are collected by a sensor array; Decoding the pulse density modulation signals of multiple channels to obtain pulse code modulation signals; Adjusting the bit width of the pulse code modulation signal to obtain an ultrasonic output signal; The ultrasonic output signal is positioned based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

2. The multi-channel ultrasonic signal parallel processing method according to claim 1, characterized in that: The method of performing signal modulation processing on the ultrasonic signals of the multiple channels respectively to obtain a pulse density modulation signal of each channel includes: Performing acoustic-to-electric conversion processing on the ultrasonic signals of the multiple channels respectively to obtain an analog electrical signal of each channel; The modulator is used to perform signal modulation processing on the analog electrical signal of each channel to obtain a pulse density modulation signal of each channel.

3. The multi-channel ultrasonic signal parallel processing method according to claim 1, characterized in that: The decoding process of the pulse density modulation signals of the multiple channels to obtain the pulse code modulation signals includes: Performing downsampling and filtering processing on the pulse density modulation signals of the multiple channels to obtain a first filtered signal; Performing low-pass filtering on the first filtered signal to obtain a second filtered signal; The second filtered signal is subjected to convolution filtering to obtain the pulse code modulation signal.

4. The multi-channel ultrasonic signal parallel processing method according to claim 1, characterized in that: The performing positioning processing on the ultrasonic output signal based on the beamforming positioning algorithm to obtain the visual positioning information of the ultrasonic signal includes: Performing positioning processing on the ultrasonic output signal based on the beamforming positioning algorithm to obtain the sound source position of the ultrasonic output signal; The sound source position of the ultrasonic output signal is superimposed on the visual image to obtain visual positioning information of the ultrasonic output signal.

5. A multi-channel ultrasonic signal parallel processing system, applicable to the multi-channel ultrasonic signal parallel processing method according to any one of claims 1 to 4, characterized in that: The multi-channel ultrasonic signal parallel processing system comprises a multi-element microphone array board, a field programmable gate array and a host computer. The multi-element microphone array board is connected to the field programmable gate array through a board-to-board connector, and the multi-element microphone array board is configured to collect ultrasonic signals of multiple channels, and perform signal modulation processing on the ultrasonic signals of the multiple channels respectively to obtain a pulse density modulation signal of each channel; The field programmable gate array is configured to decode pulse density modulation signals of multiple channels to obtain pulse code modulation signals, and adjust the bit width of the pulse code modulation signals to obtain ultrasonic output signals; The host computer is connected to the field programmable gate array via an Ethernet cable, and the host computer is configured to perform positioning processing on the ultrasonic output signal based on a beamforming positioning algorithm to obtain visual positioning information of the ultrasonic output signal.

6. The multi-channel ultrasonic signal parallel processing system according to claim 5, characterized in that: The field programmable gate array includes a decoding module, a first-in first-out buffer module and an Ethernet module. The decoding module is configured to decode the pulse density modulation signals of the multiple channels to obtain the pulse code modulation signals; The first-in-first-out buffer module is configured to perform buffer processing on the pulse code modulation signal and adjust the data bit width of the pulse code modulation signal to obtain the ultrasonic output signal; The Ethernet module is configured to package the ultrasonic output signal according to the channel sequence and output the ultrasonic output signal through the Ethernet line.

7. The multi-channel ultrasonic signal parallel processing system according to claim 6, characterized in that: The field programmable gate array further includes a clock module, wherein the clock module is configured to provide clock signals to the decoding module, the first-in-first-out buffer module, and the Ethernet module respectively.

8. The multi-channel ultrasonic signal parallel processing system according to claim 7, characterized in that: The clock module is further configured to provide a sampling clock signal to the multi-element microphone array board, so that the multi-element microphone array board operates in an ultrasonic mode.

9. The multi-channel ultrasonic signal parallel processing system according to claim 6, characterized in that: The decoding module includes a cascaded integrator comb filter, a half-band filter and a finite impulse response filter. Among them, the cascaded integrator comb filter is used to perform downsampling filtering on the pulse density modulation signals of the multiple channels to obtain a first filtered signal; the half-band filter is used to perform low-pass filtering on the first filtered signal to obtain a second filtered signal; the finite impulse response filter is used to perform convolution filtering on the second filtered signal to obtain the pulse code modulation signal.

10. The multi-channel ultrasonic signal parallel processing system according to claim 6, characterized in that: The first-in-first-out buffer module includes a first first-in-first-out unit, a second first-in-first-out unit, and a third first-in-first-out unit. The first FIFO unit is used to perform group buffering processing on the pulse code modulation signal and perform a first bit width adjustment on the pulse code modulation signal to obtain a first intermediate pulse code modulation signal; The second FIFO unit is used to arrange the first intermediate PCR signals according to the channel sequence and perform a second bit width adjustment on the first intermediate PCR signals to obtain a second intermediate PCR signal; The third FIFO unit is used to perform a third bit width adjustment on the second intermediate pulse code modulation signal to obtain the ultrasonic output signal.

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