Method for manufacturing ultrasonic background noise by using random algorithm

Abstract

The invention relates to the field of noise manufacturing, and discloses a method for manufacturing ultrasonic background noise by using a random algorithm, which comprises the following steps of: 1, selecting an ultrasonic sensor with the working frequency of 20kHz-40kHz; step 2, generating a pseudo-random number sequence through a random algorithm to dynamically modulate the frequency and amplitude of the ultrasonic wave to ensure that the generated ultrasonic wave signal is more than 20kHz and is imperceptible to human ears; 3, adjusting the output of the ultrasonic wave by using the generated random number, and further generating background noise to interfere mainstream recording equipment; the random algorithm adopts a Mersen rotation algorithm to generate a random number, and a seed of the Mersen rotation algorithm is composed of the sum of the current environment temperature and the system starting timestamp. The highly random interference signal is generated by dynamically adjusting the frequency and the amplitude of the ultrasonic wave, so that the unpredictability and the complexity of the interference signal are remarkably improved, the sound recording equipment is difficult to filter noise through a conventional noise reduction means, and the privacy protection effect is improved.

Description

Technical Field

[0001] The invention relates to the field of noise generation, in particular to a method for generating ultrasonic background noise by using a random algorithm. Background Art

[0002] With the widespread use of smart devices, the need for privacy protection has become more urgent. Whether it is a personal conversation or a business meeting, protecting sensitive information from illegal recording has become an important issue. Existing privacy protection methods mainly rely on physical isolation or fixed-frequency noise generation. These methods are difficult to effectively resist the intelligent noise reduction function of modern recording equipment. Fixed-frequency noise is also easily filtered by active noise reduction technology and cannot provide sufficient interference effect.

[0003] Ultrasonic noise generation technology outside the human hearing range has gradually become a potential interference method due to its concealment. Since the ultrasonic frequency is higher than 20kHz, the human ear is usually unable to perceive it. Therefore, using ultrasonic signals as interference noise can achieve concealment without affecting hearing. However, most traditional ultrasonic noise interference methods use a single or preset frequency, which is difficult to cope with the noise reduction function of recording equipment. Therefore, a method for generating highly random, complex and unpredictable ultrasonic background noise is necessary, aiming to effectively interfere with a variety of recording devices to achieve efficient privacy protection. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a method for generating ultrasonic background noise using a random algorithm, which solves the problem of how to generate random and complex ultrasonic background noise to effectively interfere with recording equipment and protect privacy without affecting human ears.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a method for generating ultrasonic background noise using a random algorithm, comprising the following steps:

[0006] Step 1: Select an ultrasonic sensor with an operating frequency of 20kHz-40kHz;

[0007] Step 2: Generate a pseudo-random number sequence through a random algorithm to dynamically modulate the frequency and amplitude of the ultrasonic wave to ensure that the generated ultrasonic wave signal is above 20kHz and is imperceptible to the human ear;

[0008] Step 3: Use the generated random numbers to adjust the output of ultrasound, thereby generating background noise to interfere with mainstream recording equipment.

[0009] Preferably, the random algorithm includes but is not limited to a Mersenne twister algorithm for generating random numbers, wherein the seed of the Mersenne twister algorithm is composed of the sum of the current ambient temperature and the system startup timestamp, specifically:

[0010] seed=current_time+temperature

[0011] Among them, current_time is the timestamp of system startup, and temperature is the temperature of the current environment.

[0012] Preferably, the frequency adjustment range of the ultrasonic wave is 25kHz to 40kHz, and the frequency is generated by random number mapping, specifically:

[0013] f=25000+(rand_valuemod15000)

[0014] Where f is the generated frequency and rand_value is the generated random number. This formula ensures that the frequency varies between 25kHz and 40kHz.

[0015] Preferably, the amplitude is adjusted in the range of 0 to 5 V, and the amplitude is calculated by the following formula:

[0016]

[0017] Where A is the output amplitude, rand_value is the generated random number, and RAND_MAX is the maximum random value of the algorithm.

[0018] Preferably, in the step, low-frequency noise is removed by a high-pass filter, and the cutoff frequency of the high-pass filter is set to 20kHz. The specific design is:

[0019]

[0020] Among them, f c is the cut-off frequency, R is the resistance value, and C is the capacitance value. This formula is used to select appropriate R and C values ​​to ensure that the ultrasonic signal quality meets the standard and removes frequency components below 20kHz.

[0021] Preferably, the system includes a modulation control unit, which includes a microcontroller and a PWM module, and realizes the generation and adjustment of ultrasonic signals through programming, and the specific steps are:

[0022] The frequency and duty cycle of the PWM are set to match the frequency and amplitude being generated.

[0023] Preferably, the method performs compatibility testing on mainstream recording devices on the market, and the testing steps include:

[0024] Baseline recordings were made without ultrasonic background noise turned on;

[0025] Start the ultrasound system and record the sound to evaluate the effect of ultrasound on the recording quality.

[0026] Preferably, the system is provided with a timer to update the random number generator every 500 milliseconds, which is specifically implemented as follows:

[0027] Use the timer interrupt configuration to generate a new random number and update the frequency and amplitude every time the interrupt is triggered.

[0028] Preferably, the ultrasonic signal generating system includes a power amplifier, which uses an LM386 audio amplifier, and is specifically implemented as follows:

[0029] The PWM signal is input to the power amplifier.

[0030] The present invention provides a method for generating ultrasonic background noise by using a random algorithm. It has the following beneficial effects:

[0031] 1. The ultrasonic background noise generated by the random algorithm of the present invention can effectively interfere with the recording function of mainstream recording equipment, prevent the conversation content from being illegally recorded, and thus protect personal privacy and corporate information security.

[0032] 2. The ultrasonic frequency of the present invention is set above 20kHz, which is beyond the perceptible range of the human ear, ensuring that it will not cause any auditory interference to people around during use, so that the technology can be safely used in various occasions.

[0033] 3. The signal generated by the random algorithm adopted in the present invention is highly random and complex, which can avoid being easily filtered by the active noise reduction technology of the recording equipment, thereby improving the concealment and protection effect of the system and ensuring the effectiveness of the interference.

[0034] 4. The present invention uses a lightweight design to make the device compact and portable. With a long-lasting battery and a power monitoring module, it is convenient for users to carry it with them in various environments or use it flexibly in different scenarios, greatly improving the convenience of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Please refer to the attached Figure 1The embodiment of the present invention provides a method for generating ultrasonic background noise by using a random algorithm, comprising the following steps:

[0038] Equipment preparation:

[0039] In this embodiment, the selection of equipment includes:

[0040] Ultrasonic sensor: Choose an ultrasonic sensor with a frequency of 20kHz-40kHz (such as model XYZ-25 or XYZ-40), whose operating range is suitable for interfering with mainstream recording equipment.

[0041] Microcontroller: STM32, Arduino and other microcontrollers are used to control the generation and regulation of ultrasonic signals.

[0042] PWM module: used to generate modulation signals, so that the output of ultrasonic signals has the ability to change dynamically and increase the complexity of interference signals.

[0043] High-pass filter: Design a high-pass filter with a cutoff frequency of 20kHz to ensure that low-frequency components are removed from the output signal and improve the quality of the ultrasonic signal.

[0044] Power management unit: The design includes a voltage stabilization module and a lithium battery management module to ensure that the entire system can provide stable power during operation.

[0045] Random number generation:

[0046] In this embodiment, the steps of generating random numbers include:

[0047] Initialization seed: When the system starts, the sum of the current system timestamp (in milliseconds) and the ambient temperature (in degrees Celsius) is used as the seed to ensure that the generated random number sequence has high randomness.

[0048] seed=current_time+temperature

[0049] Random number generation: Generate random numbers through the Mersenne Twister algorithm. The specific steps include:

[0050] Initialize the state array and set the initial value;

[0051] Perform shift operations and generate new random numbers;

[0052] By outputting random numbers between 0 and RAND_MAX, the subsequent frequency and amplitude can be adjusted.

[0053] Ultrasonic signal output:

[0054] In this embodiment, the ultrasonic signal output step includes:

[0055] Frequency and amplitude adjustment: The frequency and amplitude of the ultrasonic signal are dynamically calculated based on the generated random number. The frequency is set in the range of 25kHz to 40kHz, and the amplitude is set between 0 and 5V.

[0056] f=25000+(rand_valuemod15000).

[0057]

[0058] PWM module settings: configure the PWM signal to ensure that the frequency matches the modulated frequency and adjust the duty cycle to accommodate the adjusted amplitude. The specific implementation steps include:

[0059] Set the frequency of the PWM module to match the frequency of the ultrasonic wave;

[0060] The duty cycle of the PWM signal is adjusted according to the amplitude value to achieve stable ultrasonic output.

[0061] Signal Processing:

[0062] In this embodiment, the signal processing step includes:

[0063] Design of high-pass filter: Select appropriate resistance (R) and capacitance (C) to make its cut-off frequency 20kHz. The design formula is:

[0064]

[0065] Choose appropriate R and C values ​​(eg, R = 1 kΩ, C = 10 nF) to ensure that low frequency components are removed.

[0066] Signal quality optimization: Connect the output of the ultrasonic sensor through a high-pass filter to remove unnecessary low-frequency noise and ensure the effectiveness and interference effect of the ultrasonic signal.

[0067] Performance Testing:

[0068] In this embodiment, the performance testing steps include:

[0069] Baseline Recording: Before starting the ultrasonic system, make a baseline recording in a quiet environment to ensure the equipment's recording quality without ultrasonic interference.

[0070] Turn on ultrasonic interference: Start the ultrasonic background noise system, record again, compare the recording quality before and after interference, and evaluate the effective interference of ultrasound on the recording equipment. Use audio analysis software (such as Audacity) to compare the spectrum and signal quality of the recording to confirm the interference effect.

[0071] System compatibility and portable design:

[0072] In this embodiment, the system design takes portability and compatibility into consideration, including:

[0073] Portable design: Integrate all components into a small, lightweight device that can be used flexibly in different situations. For example, a plastic housing and portable power supply can be used to reduce the weight of the device.

[0074] Power monitoring module: By setting up the power monitoring module, users can know the power status of the device at any time to avoid affecting the use due to insufficient power. The power monitoring module can use a simple LED indicator or LCD display to display the current power status and working status.

[0075] Additional features and optimizations:

[0076] In this embodiment, in order to improve the practicality of the device, the following functions may also be considered:

[0077] Remote control: The remote control function is realized through the Bluetooth or Wi-Fi module. Users can control the opening and closing of the ultrasonic wave and adjust the parameters through the mobile phone APP.

[0078] Environmental adaptive adjustment: Integrated environmental sensors (such as temperature and humidity sensors) automatically adjust the frequency and amplitude of ultrasonic output according to real-time environmental conditions to enhance the interference effect.

[0079] Embodiment 1:

[0080] In an important business meeting, participants wanted to ensure the privacy of their conversations and prevent their messages from being illegally recorded. To achieve this goal, a system that generates ultrasonic background noise based on a random algorithm was installed in the meeting room.

[0081] Equipment preparation

[0082] Ultrasonic Sensors:

[0083] An ultrasonic sensor (model XYZ-25) with an operating frequency of 25kHz was selected. This sensor has good transmission performance and is suitable for interfering with common recording equipment.

[0084] Microcontroller:

[0085] The STM32 microcontroller is used to control the entire system and generate signals. The generation and adjustment of ultrasonic signals are achieved by writing corresponding control programs.

[0086] PWM module:

[0087] A PWM module is configured to generate a modulation signal with adjustable frequency and amplitude to ensure that the output ultrasonic signal is random.

[0088] High Pass Filter:

[0089] A high-pass filter with a cutoff frequency of 20kHz was designed to ensure that the low-frequency components in the ultrasonic signal were effectively removed.

[0090] Power Management Unit:

[0091] The system is equipped with lithium batteries and voltage stabilization modules to ensure stable power supply for the equipment during the meeting.

[0092] Implementation steps

[0093] Initialize the device:

[0094] Before the meeting starts, the technician first starts the microcontroller and initializes the seed of the random number generator, using the sum of the current system time and ambient temperature to ensure that the generated random number has high randomness.

[0095] Generate random numbers:

[0096] The Mersenne twister algorithm is used to generate a pseudo-random number sequence to ensure that the output random number is used for the subsequent adjustment of the ultrasonic frequency and amplitude.

[0097] Output ultrasonic signal:

[0098] According to the generated random number, the frequency and amplitude of the ultrasonic wave are adjusted dynamically. The frequency range is set between 25kHz and 40kHz, and the amplitude is between 0 and 5V. The corresponding modulation signal is generated through the PWM module and output to the ultrasonic sensor.

[0099] Signal Processing:

[0100] Connected to the output of the ultrasonic sensor through a high-pass filter to remove unnecessary low-frequency noise and ensure the quality of the ultrasonic signal.

[0101] Performance Testing:

[0102] Before the meeting, the technicians first performed a baseline recording to ensure a quiet environment in the meeting room. Then they started the ultrasound system and performed a second recording to evaluate the effect of ultrasound on the recording equipment.

[0103] Meeting

[0104] During a business meeting, participants sat around a conference table and had an intense discussion. Due to the operation of the ultrasonic system, all conversations were interfered with by the ultrasonic background noise and could not be clearly recorded by any recording equipment.

[0105] After the meeting, the technicians analyzed the recordings and found that the content recorded by the recording equipment was severely distorted and no effective information could be extracted. This result shows that the ultrasonic background noise system successfully protected the privacy of the participants.

[0106] Embodiment 2:

[0107] In daily life, individuals sometimes participate in private conversations or business negotiations involving sensitive information. In order to protect the content of the conversation from being illegally recorded, the user carries with him the ultrasonic background noise generating device of the present invention, which is small and portable and suitable for use at any time in various occasions. The user hopes to use this device to interfere with any recording device during the conversation to avoid information leakage.

[0108] Equipment preparation

[0109] Portable Design:

[0110] The ultrasonic background noise device uses a lightweight shell with a volume of 10cm×5cm×2cm, which is easy for users to carry. The device contains a 25kHz ultrasonic sensor, which is suitable for portable use and avoids interference to the human ear.

[0111] Microcontroller and control circuit:

[0112] Arduino Nano is selected as the microcontroller, which can stably control the generation and output of ultrasonic signals. It is equipped with a high-pass filter, PWM module and power amplifier to achieve precise frequency and amplitude control.

[0113] Lithium battery and power monitoring module:

[0114] Equipped with a 3000mAh lithium battery, it supports long-term operation of the device. At the same time, the power monitoring module displays the battery status through an LED indicator light, making it convenient for users to charge in time.

[0115] Implementation steps

[0116] Device startup:

[0117] Before the user is ready to talk, he presses the device startup button. After the device is started, the microcontroller first initializes the random number generator and uses the sum of the current timestamp and the ambient temperature as the seed to ensure randomness.

[0118] Random number generation and modulation:

[0119] The Mersenne Twister algorithm is used to generate random numbers to form a pseudo-random number sequence. Based on the generated random numbers, the frequency (25kHz to 40kHz) and amplitude (0V to 5V) of the ultrasonic signal are adjusted in real time to ensure that each output signal is unique and unpredictable.

[0120] Ultrasonic signal output:

[0121] The PWM module generates a square wave signal based on the randomly generated frequency and amplitude, and drives the ultrasonic sensor to emit background noise through the power amplifier. In order to optimize the signal quality, the high-pass filter removes the low-frequency components to ensure that the output ultrasonic wave is clean and effective.

[0122] Conversation in progress:

[0123] While a conversation is ongoing, the user places the device on a nearby table or in a pocket, and the ultrasonic device continues to operate without disrupting the conversation, generating ultrasonic background noise that can interfere with any device trying to record.

[0124] Verification of privacy protection effect:

[0125] After the conversation is over, the user can verify it through the recording device. The test recording shows that due to the interference of ultrasonic background noise, the content of the recording file is not clear, the audio signal contains a lot of noise, and the content of the conversation cannot be restored.

[0126] Embodiment three:

[0127] In a company's conference room, meetings involving confidential content are frequently held. In order to protect the company's business information from being leaked, the company decided to install an ultrasonic background noise generation system in the conference room to prevent the meeting content from being illegally recorded. The system can generate highly random ultrasonic background noise during the meeting, interfering with the recording function of any recording device to ensure information security.

[0128] Equipment Installation

[0129] Ultrasonic sensor layout:

[0130] Since the conference room is large (20 square meters), multiple 25kHz and 40kHz ultrasonic sensors are selected and arranged around the ceiling of the conference room and under the conference table. The sensors are distributed at intervals of 2 meters to ensure that the ultrasonic waves cover the entire conference space.

[0131] Microcontroller and control unit:

[0132] The STM32 microcontroller is used as the core control unit to connect all ultrasonic sensors to form a centralized control. The microcontroller is programmed to generate and adjust signals, and is equipped with a PWM module and a high-pass filter to ensure that each sensor can emit an ultrasonic signal with random frequency and amplitude.

[0133] Central control panel:

[0134] A central control panel is designed and installed in the main control area of ​​the conference room for easy operation. The panel has a start button, indicator light, power monitoring module and parameter adjustment knob, and users can adjust the noise intensity and frequency range according to the meeting needs.

[0135] Power and power management system:

[0136] The system is connected to the conference room's power line and a power management module is installed to monitor and regulate power input to ensure stable operation of the system during long meetings.

[0137] Implementation steps

[0138] System startup and initialization:

[0139] Before the meeting starts, the conference administrator presses the start button on the central control panel. The system is automatically activated, and the microcontroller initializes the random number generator and uses the current timestamp as the seed to ensure that the generated ultrasonic signal has high randomness.

[0140] Random Number Generation and Signal Conditioning:

[0141] A sequence of random numbers is generated using the Mersenne Twister algorithm and used for frequency and amplitude adjustments of each sensor.

[0142] The frequency is dynamically adjusted between 25kHz and 40kHz;

[0143] The amplitude range is between 0 and 5V. The duty cycle of the output signal is controlled by the PWM module, so that the ultrasonic signal changes continuously to achieve the interference effect.

[0144] Ultrasonic signal output and sensor linkage:

[0145] The system sends a control signal to each sensor to start ultrasonic output. The signal is modulated by the PWM module and a high-pass filter is used to remove low-frequency noise, ensuring that each sensor only outputs high-frequency ultrasonic signals.

[0146] The sensors are linked and controlled through the microcontroller program to ensure that sensors in different locations output signals at different frequencies, covering the entire conference room and making the interference effect more significant.

[0147] Meeting in progress:

[0148] During the meeting, the system continuously generates ultrasonic background noise, which interferes with the normal recording function of any recording equipment in the meeting room. Since ultrasonic waves are above the hearing range of the human ear, participants do not feel any discomfort in the venue and the meeting can proceed smoothly.

[0149] End of meeting and system shutdown:

[0150] After the meeting, the administrator presses the stop button on the control panel, the system automatically stops the ultrasonic signal output, and the sensor and control unit are powered off and enter standby mode.

[0151] Effect verification and testing

[0152] Benchmark recording test:

[0153] After the system is installed, benchmark the system interference effect through a variety of common recording devices (such as smartphones, voice recorders, etc.). Record a clear audio clip in the conference room without the ultrasonic interference system activated for subsequent comparison.

[0154] System interference test:

[0155] The ultrasonic background noise system was activated, and the recording device was used to test the recording again. The comparison results showed that during the operation of the ultrasonic system, the audio recorded by the recording device was severely distorted, containing a large amount of high-frequency noise, and the content of the meeting could not be recognized.

[0156] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for generating ultrasonic background noise using a random algorithm, characterized in that: The following steps are involved: Step 1: Select an ultrasonic sensor with an operating frequency of 20kHz-40kHz; Step 2: Generate a pseudo-random number sequence through a random algorithm to dynamically modulate the frequency and amplitude of the ultrasonic wave to ensure that the generated ultrasonic wave signal is above 20kHz and is imperceptible to the human ear; Step 3: Use the generated random numbers to adjust the output of ultrasound, thereby generating background noise to interfere with mainstream recording equipment.

2. The method for generating ultrasonic background noise by using a random algorithm according to claim 1, characterized in that: The random algorithm includes but is not limited to the Mersenne Twister algorithm to generate random numbers, wherein the seed of the Mersenne Twister algorithm is composed of the sum of the current ambient temperature and the system startup timestamp, specifically: seed=current_time+temperature Among them, current_time is the timestamp of system startup, and temperature is the temperature of the current environment.

3. The method for generating ultrasonic background noise by using a random algorithm according to claim 1, characterized in that: The frequency adjustment range of the ultrasonic wave is 25kHz to 40kHz, and the frequency is generated by random number mapping, specifically: f=25000+(rand_valuemod15000) Where f is the generated frequency and rand_value is the generated random number. This formula ensures that the frequency varies between 25kHz and 40kHz.

4. The method of using a random algorithm to generate ultrasonic background noise according to claim 1, characterized in that: The amplitude is adjusted in the range of 0 to 5 V and is calculated by the following formula: Where A is the output amplitude, rand_value is the generated random number, and RAND_MAX is the maximum random value of the algorithm.

5. The method for generating ultrasonic background noise by using a random algorithm according to claim 1, characterized in that: In the step, low-frequency noise is removed by a high-pass filter, and the cutoff frequency of the high-pass filter is set to 20kHz. The specific design is: Among them, f c is the cut-off frequency, R is the resistance value, and C is the capacitance value. This formula is used to select appropriate R and C values ​​to ensure that the ultrasonic signal quality meets the standard and removes frequency components below 20kHz.

6. The method of using a random algorithm to generate ultrasonic background noise according to claim 1, characterized in that: The system includes a modulation control unit, which includes a microcontroller and a PWM module, and realizes the generation and regulation of ultrasonic signals through programming. The specific steps are as follows: The frequency and duty cycle of the PWM are set to match the frequency and amplitude being generated.

7. The method of using a random algorithm to generate ultrasonic background noise according to claim 1, characterized in that: The method performs compatibility testing on mainstream recording devices on the market, and the testing steps include: Baseline recordings were made without ultrasonic background noise turned on; Start the ultrasound system and record the sound to evaluate the effect of ultrasound on the recording quality.

8. The method of using a random algorithm to generate ultrasonic background noise according to claim 1, characterized in that: The system has a timer that updates the random number generator every 500 milliseconds. The specific implementation is: Use the timer interrupt configuration to generate a new random number and update the frequency and amplitude every time the interrupt is triggered.

9. The method of using a random algorithm to generate ultrasonic background noise according to claim 1, characterized in that: The ultrasonic signal generation system includes a power amplifier, which uses an LM386 audio amplifier and is specifically implemented as follows: The PWM signal is input to the power amplifier.

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