Vehicle-mounted voice protection method, device and equipment and computer readable storage medium

Abstract

The embodiment of the invention provides a vehicle-mounted voice protection method, device and equipment and a computer readable storage medium. The method comprises the following steps: acquiring an in-vehicle voice signal in real time; analyzing the voice signal to obtain power spectrum distribution characteristics; according to the power spectrum distribution characteristics, multiple paths of periodic short pulse sequences are constructed; generating a multi-channel ultrasonic masking signal according to the multi-path periodic short pulse sequence; and transmitting the multi-channel ultrasonic masking signal by using an ultrasonic phased array, and forming an ultrasonic sound field in a target area in the vehicle. In this way, the directional interference characteristic of the ultrasonic phased array can be utilized, accurate noise injection of illegal recording equipment is achieved, and therefore vehicle-mounted voice privacy is effectively protected under the condition that normal voice communication is not affected.

Description

Technical Field

[0001] This disclosure relates to the fields of information security and acoustics, and in particular to the field of vehicle voice protection technology. Background Technology

[0002] With the rapid development of intelligent vehicles and in-vehicle voice systems, voice, as an important means of human-computer interaction, has been widely applied in various functional modules such as navigation control, in-vehicle entertainment, communication access, and driver assistance. Voice interaction has not only greatly improved the convenience and safety of driving, but has also gradually become an important entry point for intelligent cockpits. However, the frequent use of in-vehicle voice information has also brought new information security risks, especially in open or non-enclosed scenarios such as shared mobility, public parking lots, and service and maintenance. The voice content of in-vehicle occupants is easily picked up and recorded by illegal devices such as mobile phones, dashcams, and eavesdropping devices, which may lead to identity leakage, location tracking, behavior analysis, and even be used to control in-vehicle systems and attack user accounts, seriously threatening the confidentiality of voice data and personal privacy.

[0003] Therefore, how to solve the problem of "easy to collect but difficult to protect" in-vehicle voice data and protect the security of current in-vehicle voice data has become an urgent issue. Summary of the Invention

[0004] This disclosure provides a method, apparatus, device, and storage medium for vehicle-mounted voice protection.

[0005] According to a first aspect of this disclosure, an in-vehicle voice protection method is provided. The method includes: Real-time acquisition of in-vehicle voice signals; Analyze the speech signal to obtain the power spectrum distribution characteristics; Based on the power spectrum distribution characteristics, a multi-channel periodic short pulse sequence is constructed; A multi-channel ultrasonic masking signal is generated based on the multi-channel periodic short pulse sequence; An ultrasonic phased array is used to transmit the multi-channel ultrasonic masking signal, forming an ultrasonic sound field in the target area inside the vehicle.

[0006] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the power spectral distribution characteristics include: power spectral density; The step of constructing a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics includes: Based on the power spectral density, determine the target frequency band where the speech segment with energy higher than a preset energy threshold is located in the speech signal; The target frequency band is divided into multiple independent sub-frequency bands at equal intervals; Based on the speech energy of each sub-band, the corresponding periodic short pulse sequences are determined.

[0007] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein determining the corresponding periodic short pulse sequences based on the speech energy of each sub-frequency band includes: Based on the speech energy within the nth sub-band, determine the pulse repetition period Tn and pulse width τ of the corresponding nth periodic short pulse sequence. n and amplitude An, and the energy of the nth periodic short pulse sequence is greater than the speech energy in the corresponding nth sub-band; For the nth sub-frequency band, the construction period is Tn and the pulse width is τ. n And a periodic short pulse sequence with amplitude An, wherein the total number of sub-bands is N, the value of n is in the range of 1 to N, and n is a positive integer.

[0008] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein generating a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence includes: Acquire multiple preset high-frequency carrier signals; The multi-channel ultrasonic masking signal is obtained by multiplying each of the periodic short pulse sequences in the multi-channel periodic short pulse sequence with its corresponding preset high-frequency carrier signal. Each of the periodic pulse sequences corresponds to a preset high-frequency carrier signal. The center frequency of the nth preset high-frequency carrier signal is greater than the center frequency of the nth sub-band in the speech signal. The value of n ranges from 1 to N, where n is a positive integer and N is the total number of sub-bands.

[0009] In addition to the aspects described above and any possible implementation, a further implementation is provided in which the center frequency of the nth preset high-frequency carrier signal is greater than the lowest frequency of the ultrasound, and the difference frequency of the nth preset high-frequency carrier signal is within the effective bandwidth of the ultrasound phased array, and each periodic short pulse sequence corresponds to one ultrasound masking signal.

[0010] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the transmission of the multi-channel ultrasonic masking signal using an ultrasonic phased array includes: The ultrasonic phased array includes an ultrasonic transducer array element equal to the number of the periodic short pulse sequence, and each ultrasonic transducer array element corresponds to an independent transmission channel, and each transmission channel is input with an ultrasonic masking signal. Adjust the phase difference between each ultrasonic transducer array element, and use each transmission channel to perform phase control on each input ultrasonic masking signal; Each transmission channel is used to perform gain compensation on the input ultrasonic masking signal to form an ultrasonic sound field in the target area inside the vehicle.

[0011] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the ultrasonic masking signal in the ultrasonic sound field is mixed by the nonlinear mixing effect of the diaphragm of the recording device to obtain a noisy speech signal; wherein:

[0012] The noisy speech signal, Let be the ultrasonic masking signal of the nth channel in the ultrasonic sound field. Let n be the nonlinear coefficient of the diaphragm, and n ranges from 1 to N, where n is a positive integer.

[0013] According to a second aspect of this disclosure, an in-vehicle voice protection device is provided. The device includes: The acquisition module is used to acquire in-vehicle voice signals in real time; The analysis module analyzes the speech signal to obtain the power spectrum distribution characteristics; A construction module is used to construct a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics; The generation module is used to generate a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence; The transmitting module is used to transmit the multi-channel ultrasonic masking signal using an ultrasonic phased array, forming an ultrasonic sound field in the target area inside the vehicle.

[0014] According to a third aspect of this disclosure, an electronic device is provided. The electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the program to implement the method described above.

[0015] According to a fourth aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon that, when executed by a processor, implements the method according to a first aspect of this disclosure.

[0016] In this disclosure, after real-time acquisition of in-vehicle voice signals, the voice signals can be analyzed to obtain power spectrum distribution characteristics. Then, based on the power spectrum distribution characteristics, a multi-channel periodic short pulse sequence is constructed. Subsequently, based on the multi-channel periodic short pulse sequence, a multi-channel ultrasonic masking signal that is inaudible to the human ear is generated. Then, an ultrasonic phased array is used to transmit the multi-channel ultrasonic masking signal to form an ultrasonic sound field in the target area inside the vehicle, thereby creating an inaudible ultrasonic masking environment in the cabin. In this way, even if an illegal device attempts to record the voice signal, it will only record an ultrasonic masking signal that is inaudible to the human ear. Thus, the directional interference characteristics of the ultrasonic phased array can be used to achieve precise noise injection against illegal recording devices, thereby effectively protecting in-vehicle voice privacy without affecting normal voice communication.

[0017] It should be understood that the description in the Summary of the Invention is not intended to limit the key or essential features of the embodiments of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0018] The above and other features, advantages, and aspects of the embodiments of this disclosure will become more apparent from the accompanying drawings and the following detailed description. The drawings are provided for a better understanding of the invention and are not intended to limit the scope of this disclosure. In the drawings, the same or similar reference numerals denote the same or similar elements, wherein: Figure 1 A flowchart of an in-vehicle voice protection method according to an embodiment of the present disclosure is shown; Figure 2 A block diagram of an in-vehicle voice protection system according to an embodiment of the present disclosure is shown; Figure 3a and 3b for Figure 2 Time-domain and frequency-domain plots of voice signals collected by the vehicle-mounted voice protection system under interference-free conditions; Figure 4a and 4b for Figure 2 Time-domain and frequency-domain plots of the mixed, noisy voice signal collected by the vehicle-mounted voice protection system; Figure 5 A block diagram of an in-vehicle voice protection device according to an embodiment of the present disclosure is shown; Figure 6 A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown.

[0019] Figure label: 01-Microphone; 02-Human voice source; 03-Arbitrary waveform generator; 04-Multi-channel drive circuit integrating mixing, filtering and power amplification; 05-Ultrasonic phased array; 06-Smartphone. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0021] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0022] Figure 1 A flowchart of an in-vehicle voice protection method 100 according to an embodiment of the present disclosure is shown. Method 100 may include: Step 110: Real-time acquisition of in-vehicle voice signals; The voice signal is the voice emitted by the passenger and / or the driver inside the vehicle; Step 120: Analyze the speech signal to obtain the power spectrum distribution characteristics; Analyzing speech signals can yield characteristic parameters such as pulse frequency, pulse width, amplitude, and duty cycle, and thus the power spectrum distribution characteristics.

[0023] The power spectrum distribution characteristic can be the power spectral density, which is the square of the spectrum.

[0024] Step 130: Based on the power spectrum distribution characteristics, construct a multi-channel periodic short pulse sequence; Multi-channel periodic short pulse sequences can be , where n represents the frequency band number, the frequency of each short pulse sequence covers the corresponding frequency band of the speech signal, and its energy is greater than the energy of the speech signal in the corresponding frequency band.

[0025] Step 140: Generate a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence; Step 150: Using an ultrasonic phased array, the multi-channel ultrasonic masking signal is emitted to form an ultrasonic sound field in the target area inside the vehicle. The ultrasonic phased array can be installed in any location inside the vehicle, such as the back of the front seat, the speaker, or the door.

[0026] After real-time acquisition of in-vehicle voice signals, the voice signals can be analyzed to obtain power spectrum distribution characteristics. Then, based on the power spectrum distribution characteristics, a multi-channel periodic short pulse sequence is constructed. Subsequently, based on the multi-channel periodic short pulse sequence, a multi-channel ultrasonic masking signal that is inaudible to the human ear is generated. Then, using an ultrasonic phased array, the multi-channel ultrasonic masking signal is emitted to form an ultrasonic sound field in the target area inside the vehicle, thereby creating an inaudible ultrasonic masking environment in the cabin. In this way, even if an illegal device attempts to record the voice signal, it will only record an inaudible ultrasonic masking signal. Furthermore, the ultrasonic masking signal will cause mixing when it enters the illegal recording device, resulting in a noisy voice signal. Thus, the directional interference characteristics of the ultrasonic phased array can be used to achieve precise noise injection into illegal recording devices, thereby effectively protecting in-vehicle voice privacy without affecting normal voice communication.

[0027] In some embodiments, the power spectral distribution characteristics include: power spectral density; The step of constructing a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics includes: Based on the power spectral density, determine the target frequency band where the speech segment with energy higher than a preset energy threshold is located in the speech signal; That is, to determine the target frequency band where the main energy of the speech signal is concentrated. .

[0028] The target frequency band is divided into multiple independent sub-frequency bands at equal intervals; Based on the speech energy of each sub-band, the corresponding periodic short pulse sequences are determined.

[0029] Perform a Fourier transform on the collected speech signal to obtain its spectrum. and power spectral density ; Based on power spectral density Determine the main energy concentration band of the speech signal. ; The frequency band Divided into N independent interference sub-bands at equal intervals , where n = 1,2, …, N, and N is the total number of sub-bands; In some embodiments, determining the corresponding periodic short pulse sequences based on the speech energy of each sub-frequency band includes: Based on the speech energy within the nth sub-band, determine the pulse repetition period Tn and pulse width τ of the corresponding nth periodic short pulse sequence. n and amplitude An, and the energy of the nth periodic short pulse sequence is greater than the speech energy in the corresponding nth sub-band; For the nth sub-frequency band, the construction period is Tn and the pulse width is τ. n And a periodic short pulse sequence with amplitude An, wherein the total number of sub-bands is N, the value of n is in the range of 1 to N, and n is a positive integer.

[0030] Based on the speech energy within each sub-band, the corresponding periodic short pulse sequence is determined. pulse repetition period Pulse width and amplitude This is to ensure that the energy Ep of the periodic shortwave pulse sequence is greater than the speech energy Ev in the corresponding sub-band.

[0031] in, In the middle, 'p' represents the first letter of 'pulse'; n is a positive integer, ranging from 1 to N, and t is time.

[0032] For the nth sub-band, the construction period is... Pulse width and amplitude Periodic short pulse sequences The nth periodic short pulse sequence center frequency It is the frequency center of the nth sub-band, and the duty cycle of the short pulse sequence. The short pulses used can be rectangular pulses, Gaussian pulses, triangular pulses, etc.

[0033] In some embodiments, generating a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence includes: Acquire multiple preset high-frequency carrier signals; The multi-channel ultrasonic masking signal is obtained by multiplying each of the periodic short pulse sequences in the multi-channel periodic short pulse sequence with its corresponding preset high-frequency carrier signal. Each of the periodic pulse sequences corresponds to a preset high-frequency carrier signal. The center frequency of the nth preset high-frequency carrier signal is greater than the center frequency of the nth sub-band in the speech signal. The value of n ranges from 1 to N, where n is a positive integer and N is the total number of sub-bands.

[0034] Each periodic short pulse sequence corresponds to a preset high-frequency carrier signal. By multiplying each periodic short pulse sequence with its corresponding preset high-frequency carrier signal, a multi-channel ultrasonic masking signal that is inaudible to the human ear can be obtained.

[0035] For the nth frequency band, the periodic short pulse sequence With high-frequency carrier signal Multiplying them together yields the ultrasonic masking signal. ,in The center frequency of the carrier of the preset high-frequency carrier signal for the nth channel is set, and Much larger (i.e., the frequency center of the nth sub-band), such that The spectrum is located in the ultrasonic band, where, In this context, 'c' represents the first letter of 'center', 'm' represents the first letter of 'modulation', and 'n' and 't' have the same explanation.

[0036] In some embodiments, the center frequency of the nth preset high-frequency carrier signal is greater than the lowest frequency of the ultrasound, and the difference frequency of the nth preset high-frequency carrier signal is within the effective bandwidth of the ultrasound phased array. Each periodic short pulse sequence corresponds to one ultrasound masking signal.

[0037] The difference frequency of the nth preset high-frequency carrier signal is 。

[0038] The difference frequency of the nth preset high-frequency carrier signal All are within the effective bandwidth of the ultrasonic phased array to ensure that each channel's periodic short pulse sequence can be modulated into an ultrasonic signal using the preset high-frequency carrier signal of each channel.

[0039] In some embodiments, transmitting the multi-channel ultrasonic masking signal using an ultrasonic phased array includes: The ultrasonic phased array includes an ultrasonic transducer array element equal to the number of the periodic short pulse sequence, and each ultrasonic transducer array element corresponds to an independent transmission channel, and each transmission channel is input with an ultrasonic masking signal. Adjust the phase difference between each ultrasonic transducer array element, and use each transmission channel to perform phase control on each input ultrasonic masking signal; Each transmission channel is used to perform gain compensation on the input ultrasonic masking signal to form an ultrasonic sound field in the target area inside the vehicle.

[0040] Each ultrasonic ring energy element can be used to transmit each ultrasonic masking signal through its channel to the target area of ​​the carriage to form an ultrasonic sound field.

[0041] By adjusting the phase difference between each ultrasonic transducer array element, ultrasonic waves can be coherently superimposed in a preset target area within the cockpit, forming a directional high sound pressure level ultrasonic sound field. The sound pressure level of the ultrasonic sound field is higher than the nonlinear mixing threshold of the recording equipment, thereby achieving effective sound field coverage of the cockpit area.

[0042] The specific phase control and gain compensation methods are as follows: Each transmission channel receives the input ultrasonic masking signal. Perform independent phase control and gain compensation; the gain compensation is achieved by a power amplifier within the channel, with the amplification factor set to... The N array elements independently transmit signals through their respective channels. .

[0043] In some embodiments, the ultrasonic masking signal in the ultrasonic sound field is mixed using the nonlinear mixing effect of the recording device diaphragm to obtain a noisy speech signal; wherein:

[0044] The noisy speech signal, Let be the ultrasonic masking signal of the nth channel in the ultrasonic sound field. Let n be the nonlinear coefficient of the diaphragm, where n ranges from 1 to N, n is a positive integer, and t is time.

[0045] because It contains the nth periodic short pulse sequence. and the nth high-frequency carrier signal The mixing process, after undergoing a second nonlinear term, will generate a frequency band covering the main energy concentration area of ​​the original speech signal. Injection noise .

[0046] The present invention provides a vehicle-mounted voice protection method based on ultrasonic phased array and nonlinear mixing, comprising the following steps: 1) Collect voice signals and determine interference parameters Real-time acquisition of in-vehicle voice signals via a microphone is used to analyze their spectral and power spectrum distribution characteristics in order to determine the characteristic parameters of the interference pulse sequence used to generate masking noise. These characteristic parameters include, but are not limited to, pulse frequency, pulse width, amplitude, and duty cycle. Specifically: For the collected voice signals Perform a Fourier transform to obtain its spectrum. and power spectral density According to power spectral density Determine the main energy concentration band of the speech signal. The frequency band is divided into N independent interference sub-bands at equal intervals. ,in n = 1, 2, …, N Based on the speech energy within each sub-band, determine the corresponding periodic short pulse sequence. pulse repetition period T Pulse width τ and amplitude A To satisfy the energy of the pulse sequence Greater than the speech energy in the corresponding sub-band It is worth noting that the microphone used here can be the existing microphone of the vehicle's voice system, or a microphone specifically deployed for this invention. Its function is to provide real-time voice information for analysis. Furthermore, the analysis of the voice signal can employ various digital signal processing techniques, such as wavelet transform and spectral smoothing, to more accurately determine the energy distribution of the voice.

[0047] 2) Constructing interference pulse sequences by frequency band division Based on the aforementioned characteristic parameters, a multi-channel periodic short pulse sequence is constructed by dividing the frequency bands. s p,n ( t ), where n represents the frequency band number; the frequency of each short pulse sequence covers the speech signal frequency band, and its energy is greater than the energy of the speech signal. Specifically, for the first... n Each sub-band, construction period is T n Pulse width is τ n Amplitude Periodic short pulse sequences ,That It is the frequency center of the nth sub-band in the speech signal (i.e., the nth periodic short pulse sequence). The center frequency), and the duty cycle of the short pulse sequence. It is worth noting that the short pulses used can be rectangular pulses, Gaussian pulses, triangular pulses, etc. Furthermore, the pulse energy... According to , and Calculate parameters such as energy of the speech signal. Real-time comparisons are performed to dynamically adjust pulse parameters.

[0048] 3) Mixing and generating ultrasonic masking signals For each frequency band, a corresponding center frequency is generated. high-frequency carrier signal The high-frequency carrier signal With the corresponding periodic short pulse sequence Upmixing is performed, and bandpass filtering based on the corresponding bandwidth and center frequency is used to generate a multi-channel ultrasonic masking signal. Specifically, for the first n Each frequency band will contain a periodic short pulse sequence. With high-frequency carrier signal = Multiplying them together yields the ultrasonic masking signal. It is worth noting that, Let be the center frequency of the nth high-frequency carrier signal, and Much larger , making The frequency spectrum is located in the ultrasonic band. It should be noted that the high-frequency carrier signal... center frequency The selection satisfies: Greater than the lowest frequency of ultrasound (e.g., 20 kHz), and the possible difference frequency. All are within the effective bandwidth of the ultrasonic phased array.

[0049] 4) Directional transmission of ultrasonic phased array Using a multi-channel controlled ultrasonic phased array, the multi-channel ultrasonic masking signal is... The system launches a high-sound-pressure-level ultrasonic field in the target area, creating an inaudible ultrasonic masking environment within the cockpit. Specifically, the ultrasonic phased array comprises N independent ultrasonic transducer elements, each corresponding to an independent transmission channel; each transmission channel receives the input ultrasonic masking signal. Perform independent phase control and gain compensation; the gain compensation is achieved by a power amplifier within the channel, with the amplification factor set to... The N array elements independently transmit signals through their respective channels. It is worth noting that by adjusting the phase difference between each array element, the ultrasonic waves can be coherently superimposed in a preset target area within the cabin (such as an illegal recording device in the passenger seat), forming a high sound pressure level ultrasonic sound field. The sound pressure level of this ultrasonic sound field is higher than the nonlinear mixing threshold of the recording device, thereby achieving effective sound field coverage of the cabin area. Furthermore, the phase difference can be dynamically calculated based on the target location using beamforming algorithms, such as time-delay beamforming or Fourier beamforming.

[0050] 5) Noise injection achieved through nonlinear mixing The ultrasonic masking signal in the ultrasonic sound field By utilizing the nonlinear mixing effect of the recording equipment's diaphragm, the signal is down-mixed to the speech frequency band, thereby injecting noise into the recording equipment and achieving the purpose of protecting in-vehicle voice recordings. Specifically, when the ultrasonic masking signal... After entering the recording device, due to the non-linear characteristics of the diaphragm, its output signal... It can be represented as:

[0051] The noisy speech signal, Let be the ultrasonic masking signal of the nth channel in the ultrasonic sound field. Let n be the nonlinear coefficient of the diaphragm, and n ranges from 1 to N, where n is a positive integer.

[0052] It is worth noting that, due to Includes and The mixing, after a second nonlinear term The function of difference frequency It just covers the original audio segment This generates injected noise in the speech frequency band that cannot be effectively filtered out, thus masking the speech information. Furthermore, in addition to the quadratic nonlinear term, higher-order nonlinear terms also produce mixing products, but the quadratic term is usually the main source of effective downmixing noise.

[0053] Example 2 This embodiment, based on the method of Embodiment 1, performs voice protection for in-vehicle voice systems in an in-vehicle environment. Through the in-vehicle voice protection method based on ultrasonic phased array and nonlinear mixing of this invention, noise injection from illegal recording devices is prevented. The specific steps are as follows: 1) Implementing device such as Figure 2 As shown, the device of the present invention is deployed in a car cabin and mainly includes: a microphone 01 for collecting voice signals, a human voice source 02, an arbitrary waveform generator 03 for generating interference pulse sequences, a multi-channel drive circuit 04 for upmixing, filtering, and power amplification, an ultrasonic phased array 05 composed of N = 4 ultrasonic transducer elements, and an Android smartphone 06 as an illegal recording device. The ultrasonic phased array 05 is installed in front of the car cabin seats, facing the passenger area, and the center frequency of each ultrasonic transducer is... The frequency range is 25-50 kHz. The speech signal from the sound source 02 is acquired in real-time by microphone 01, and an arbitrary waveform generator 03 generates an ultrasonic masking signal for interference. A multi-channel drive circuit 04 provides independent signal amplification and phase control for each element of the ultrasonic phased array 05, driving the ultrasonic transducer to emit ultrasound towards the passenger area. Before implementation, a pre-recorded speech signal is played inside the vehicle, the device of this invention is activated, and the speech is recorded using a mobile phone 06. Figure 3a and 3b These are the time-domain and frequency-domain images of the audio signal from audio source 02, recorded by mobile phone 06 when there is no interference.

[0054] 2) Play an audio signal inside the vehicle and continuously collect data for 90 seconds. Perform a Fourier transform on the collected audio signal to obtain its power spectral density. .according to Determine the main energy concentration band of the speech signal = [50, 1850] Hz, this frequency band is divided into N = 4 independent interference sub-bands at equal intervals. Based on the speech energy in each sub-band, the corresponding periodic short pulse sequence is determined. pulse repetition period Pulse width For example, for the sub-band with the highest energy, its pulse repetition period... Set to 8 ms, pulse width Set to 60 μs.

[0055] 3) Based on the parameters determined in step 2), construct multiple periodic rectangular short pulse sequences by frequency band division. For each frequency band, generate the corresponding center frequency. high-frequency carrier signal The high-frequency carrier signal With the corresponding short pulse sequence Multiply, then upmix, to generate a multi-channel ultrasonic masking signal. .here Much higher than the highest frequency of the speech signal, therefore Its spectrum is located in the ultrasonic band, which is imperceptible to the human ear.

[0056] 4) When the ultrasonic masking signal in the directional ultrasonic beam acts on the microphone diaphragm of the smartphone 06, the ultrasonic signal will be down-mixed to the speech band due to the nonlinear effect of the diaphragm. For example... Figure 4a and 4b The time-domain and frequency-domain graphs of the noisy speech signal collected by the microphone of smartphone 06 under ultrasonic phased array interference show that after ultrasonic phased array interference is turned on, the frequency band of the speech signal is completely covered by the injected noise, which effectively prevents the recognition of the speech content.

[0057] This method addresses the shortcomings of traditional acoustic jamming techniques, such as audible interference, non-directional interference, and low control precision. By performing spectral analysis on the acquired speech signal, the interference pulse parameters are dynamically determined, and an ultrasonic masking signal is constructed. Then, through phase and gain control of a multi-channel ultrasonic phased array, directional sound field coverage of the target area is achieved. This method can accurately and controllably interfere with the listening path without affecting normal user communication. It features non-intrusive noise injection, precise directional jamming, high-precision adaptability, and efficient parallel processing, meeting the high requirements of voice security protection in automotive cockpits and possessing extremely high practical application potential.

[0058] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, because according to this disclosure, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily essential to this disclosure.

[0059] The above is an introduction to the method embodiments. The following describes the solution described in this disclosure further through device embodiments.

[0060] Figure 5 A block diagram of an in-vehicle voice protection device 500 according to an embodiment of the present disclosure is shown. Figure 5 As shown, the device 500 includes: Acquisition module 510 is used to acquire in-vehicle voice signals in real time; Analysis module 520 analyzes the speech signal to obtain power spectrum distribution characteristics; The construction module 530 is used to construct a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics; The generation module 540 is used to generate a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence; The transmitting module 550 is used to transmit the multi-channel ultrasonic masking signal using an ultrasonic phased array to form an ultrasonic sound field in the target area inside the vehicle.

[0061] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the described module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0062] According to embodiments of the present disclosure, the present disclosure also provides an electronic device and a non-transitory computer-readable storage medium storing computer instructions.

[0063] Figure 6 A schematic block diagram of an electronic device 800 that can be used to implement embodiments of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the present disclosure described and / or claimed herein.

[0064] Device 800 includes a computing unit 801, which can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) 802 or a computer program loaded from storage unit 808 into random access memory (RAM) 803. RAM 803 may also store various programs and data required for the operation of device 800. The computing unit 801, ROM 802, and RAM 803 are interconnected via bus 804. Input / output (I / O) interface 805 is also connected to bus 804.

[0065] Multiple components in device 800 are connected to I / O interface 805, including: input unit 806, such as keyboard, mouse, etc.; output unit 807, such as various types of monitors, speakers, etc.; storage unit 808, such as disk, optical disk, etc.; and communication unit 809, such as network card, modem, wireless transceiver, etc. Communication unit 809 allows device 800 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0066] The computing unit 801 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 801 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 801 performs the various methods and processes described above, such as method 100. For example, in some embodiments, method 100 may be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 808. In some embodiments, part or all of the computer program may be loaded and / or installed on device 800 via ROM 802 and / or communication unit 809. When the computer program is loaded into RAM 803 and executed by the computing unit 801, one or more steps of method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 801 may be configured to perform method 100 by any other suitable means (e.g., by means of firmware).

[0067] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0068] The program code used to implement the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0069] In the context of this disclosure, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0070] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0071] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0072] Computing systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0073] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0074] The specific embodiments described above do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A vehicle-mounted voice protection method, characterized in that, include: Real-time acquisition of in-vehicle voice signals; Analyze the speech signal to obtain the power spectrum distribution characteristics; Based on the power spectrum distribution characteristics, a multi-channel periodic short pulse sequence is constructed; Based on the multi-channel periodic short pulse sequence, a multi-channel ultrasonic masking signal is generated; An ultrasonic phased array is used to transmit the multi-channel ultrasonic masking signal, forming an ultrasonic sound field in the target area inside the vehicle.

2. The method as described in claim 1, characterized in that, The power spectral distribution characteristics include: power spectral density; The step of constructing a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics includes: Based on the power spectral density, determine the target frequency band where the speech segment with energy higher than a preset energy threshold is located in the speech signal; The target frequency band is divided into multiple independent sub-frequency bands at equal intervals; Based on the speech energy of each sub-band, the corresponding periodic short pulse sequences are determined.

3. The method as described in claim 2, characterized in that, The step of determining the corresponding periodic short pulse sequences based on the speech energy of each sub-frequency band includes: Based on the speech energy within the nth sub-band, determine the pulse repetition period Tn and pulse width τ of the corresponding nth periodic short pulse sequence. n and amplitude An, and the energy of the nth periodic short pulse sequence is greater than the speech energy in the corresponding nth sub-band; For the nth sub-frequency band, the construction period is Tn and the pulse width is τ. n And a periodic short pulse sequence with amplitude An, wherein the total number of sub-bands is N, the value of n is in the range of 1 to N, and n is a positive integer.

4. The method as described in claim 1, characterized in that, The step of generating a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence includes: Acquire multiple preset high-frequency carrier signals; The multi-channel ultrasonic masking signal is obtained by multiplying each of the periodic short pulse sequences in the multi-channel periodic short pulse sequence with its corresponding preset high-frequency carrier signal. Each of the periodic pulse sequences corresponds to a preset high-frequency carrier signal. The center frequency of the nth preset high-frequency carrier signal is greater than the center frequency of the nth sub-band in the speech signal. The value of n ranges from 1 to N, where n is a positive integer and N is the total number of sub-bands.

5. The method as described in claim 4, characterized in that, The center frequency of the nth preset high-frequency carrier signal is greater than the lowest frequency of the ultrasound, and the difference frequency of the nth preset high-frequency carrier signal is within the effective bandwidth of the ultrasound phased array. Each periodic short pulse sequence corresponds to one ultrasound masking signal.

6. The method as described in claim 1, characterized in that, The method of transmitting the multi-channel ultrasonic masking signal using an ultrasonic phased array includes: The ultrasonic phased array includes an ultrasonic transducer array element equal to the number of the periodic short pulse sequence, and each ultrasonic transducer array element corresponds to an independent transmission channel, and each transmission channel is input with an ultrasonic masking signal. Adjust the phase difference between each ultrasonic transducer array element, and use each transmission channel to perform phase control on each input ultrasonic masking signal; Each transmission channel is used to perform gain compensation on the input ultrasonic masking signal to form an ultrasonic sound field in the target area inside the vehicle.

7. The method according to any one of claims 1 to 6, characterized in that, The ultrasonic masking signal in the ultrasonic sound field is mixed by the nonlinear mixing effect of the recording device diaphragm to obtain a noisy speech signal; wherein: The noisy speech signal, Let be the ultrasonic masking signal of the nth channel in the ultrasonic sound field. Let n be the nonlinear coefficient of the diaphragm, and n ranges from 1 to N, where n is a positive integer.

8. A vehicle-mounted voice protection device, characterized in that, include: The acquisition module is used to acquire in-vehicle voice signals in real time; The analysis module analyzes the speech signal to obtain the power spectrum distribution characteristics; A construction module is used to construct a multi-channel periodic short pulse sequence based on the power spectrum distribution characteristics; The generation module is used to generate a multi-channel ultrasonic masking signal based on the multi-channel periodic short pulse sequence; The transmitting module is used to transmit the multi-channel ultrasonic masking signal using an ultrasonic phased array, forming an ultrasonic sound field in the target area inside the vehicle.

9. An electronic device, characterized in that, include: Memory and processor The memory stores a computer program, and when the processor executes the program, it implements the method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, When the instructions in the storage medium are executed by the processor corresponding to the electronic device, the electronic device is able to implement the vehicle voice protection method as described in any one of claims 1-7.

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