Real-time head tracking-based spatial audio implementation method of Bluetooth headset

Abstract

According to the method, the gyroscope real-time tracking technology and the spatial audio processing algorithm are creatively and deeply fused, the dynamic spatial audio capability is added to the Bluetooth headset, the tiny movement of the head of a user can be accurately captured, the audio direction and distance can be adjusted in real time, and unprecedented immersive sound effect experience is provided. Meanwhile, by combining low-power-consumption design and real-time optimization, the problems of high power consumption and relatively large delay in the prior art are solved, so that the system not only meets high-requirement scenes such as virtual reality and augmented reality, but also adapts to daily multimedia application requirements.

Description

Technical Field

[0001] The present invention belongs to the field of consumer electronics and audio processing technology, and in particular relates to a technology for realizing real-time head tracking and dynamic spatial audio adjustment of a Bluetooth headset by using gyroscope data. Background Art

[0002] With the development of virtual reality (VR) and augmented reality (AR) technologies, users have put forward higher requirements for the spatial sound performance of audio equipment. However, traditional Bluetooth headsets usually only support fixed stereo effects and cannot respond to real-time position changes of the user's head. This limitation significantly affects the immersive sound experience, especially in scenarios such as VR / AR that require a sense of space. In the existing technology, although some headphones support simple channel separation, the following problems are common: lack of real-time tracking and feedback capabilities of head movement data; spatial audio processing algorithms consume high energy, limiting battery life; signal processing delays are large, affecting user experience.

[0003] Therefore, there is an urgent need for a technical solution that can combine real-time head tracking and efficient audio processing algorithms to provide a more natural and accurate immersive auditory experience. Summary of the invention

[0004] The present invention provides a spatial audio implementation method for a Bluetooth headset based on real-time head tracking. By integrating a gyroscope, an advanced audio processing unit, a multi-channel digital power amplifier and a power management module, the method can accurately capture the user's head movement data and adjust the audio output in real time. The method optimizes the battery life through a low-power design and adapts to a variety of scenarios. The method improves the sound performance of traditional headsets in applications such as virtual reality and augmented reality, and significantly enhances the user experience.

[0005] Specifically, the Bluetooth headset system of the present invention includes the following key components: Gyroscope: A six-axis gyroscope chip that captures the user's head motion data in real time, including rotational angular velocity and acceleration. This data is used to accurately calculate the current orientation and position change of the user's head.

[0006] Audio processing unit: It has high-performance digital signal processing capabilities. According to the head movement data provided by the gyroscope, it realizes dynamic adjustment and positioning of sound through the predetermined head-related transfer function (HRTF) and interaural time difference (ITD) and interaural sound pressure difference (ILD) algorithms.

[0007] Multi-channel digital power amplifier: Provides independent amplification channels and mid-high and bass frequency division outputs for the built-in crossover speaker driver, ensuring high-fidelity output of audio signals, and can change the audio intensity and quality in real time according to the adjustment of the audio processing unit.

[0008] Power management system: optimizes battery usage and supports long-term operation of the headset without sacrificing performance. It can intelligently adjust power consumption according to the usage status of the headset to extend the life of the headset.

[0009] Through the combination of these technologies, the Bluetooth headset of the present invention can adjust the audio output in real time when the user moves his head to simulate the direction and distance of sound in the real world, greatly improving the audio experience of applications such as virtual reality and augmented reality. In addition, the headset also pays special attention to energy efficiency. Through the application of digital amplifiers and intelligent power management, the battery life is maximized without sacrificing sound quality, making it suitable for long-term use.

[0010] The Bluetooth headset has a new type of spatial audio effect, which is characterized by capturing head movement through a gyroscope inside the headset; transmitting movement data to an audio processing unit; and adjusting the audio signal according to the position and direction of the head to simulate the effect of sound moving in three-dimensional space.

[0011] The method for implementing spatial audio by integrating a gyroscope in the Bluetooth headset is characterized in that after the Bluetooth headset is turned on, it is connected to a mobile phone device via Bluetooth, and the spatial audio function is turned on by pressing the power button for 2 seconds when the music is paused. When playing music, the gyroscope is directly connected to the audio processor, and the audio processor adjusts the output of the left and right channels according to the data of the gyroscope to achieve dynamic adjustment of the spatial sound effect; After the Bluetooth headset turns on the spatial audio, the gyroscope detects the user's head posture in real time. When the user changes the head posture, the MCU recognizes the change in the user's head posture through the gyroscope, and the MCU outputs a signal to the audio processor for audio output processing to achieve different volume level changes for the left and right channels, thereby achieving a three-dimensional spatial surround sound effect; The gyroscope in the Bluetooth headset is a six-axis gyroscope chip, which is characterized in that the working principle of the six-axis gyroscope is based on microelectronic technology and mechanical principles; when an object undergoes linear acceleration or rotation, the gyroscope and the accelerometer will be subjected to corresponding forces; the gyroscope measures the rotational angular velocity of the object by detecting tiny vibrations, while the accelerometer measures the linear motion acceleration of the object by detecting gravitational acceleration and non-gravitational acceleration; In the Bluetooth headset, the integration of a gyroscope is crucial to the realization of spatial audio technology. The gyroscope can detect the user's head movements in real time, including rotation, tilt, etc. By combining the gyroscope data with the audio processing algorithm, the direction of the sound can be dynamically adjusted so that the sound always maintains a consistent relative position with the user's head. In the Bluetooth headset, the gyroscope is electrically connected to the MCU, and its characteristic is that the gyroscope performs full-duplex communication with the MCU through the IIC mode, SCL and SDA are the IIC interfaces connected to the MCU, and the MCU controls the opening and closing of the gyroscope through this IIC interface.

[0012] In the Bluetooth headset, the digital power amplifier is electrically connected to the MCU through an I2S communication method, characterized in that the digital power amplifier performs full-duplex communication with the MCU through an IIC method, SCL and SDA are IIC interfaces connected to the MCU, and the MCU controls the opening and closing of the digital power amplifier through this IIC interface; The digital amplifier is connected to the MCU via a high-speed digital audio interface to ensure efficient transmission of audio data. The serial clock SCLK of the digital amplifier is also called clock (BCLK), that is, SCLK has 1 pulse for each bit of digital audio data. The frequency of SCLK = 2 × sampling frequency × number of sampling bits; The frame clock LRCK (also called WS) of the digital power amplifier is used to switch the data of the left and right channels. When LRCK is "1", it means that the data of the right channel is being transmitted, and when it is "0", it means that the data of the left channel is being transmitted. The frequency of LRCK is equal to the sampling frequency; The serial data SDATA0 of the digital power amplifier, input data, is the audio data represented by binary complement code, and if it is half-duplex, there is only one data line; The serial data SDATA1 of the digital power amplifier, output data, is the audio data represented by binary complement code, and the full-duplex has two data lines; The MCLK of the digital power amplifier is called the master clock, also called the system clock (Sys Clock), which is 256 times or 384 times the sampling frequency in order to achieve better synchronization between systems.

[0013] The digital power amplifier can greatly restore the audio signal received by the mobile phone, which greatly improves the user's hearing experience. At the same time, the digital power amplifier greatly reduces the power consumption.

[0014] The method for implementing spatial audio with gyroscope integration in the Bluetooth headset is characterized by an audio processing unit, which is an audio processing technology that can simulate the distribution and movement of sound in three-dimensional space. It uses the auditory characteristics of the human ear, such as interaural time difference (ITD), interaural sound pressure difference (ILD), head-related transfer function (HRTF), etc., and realizes the positioning and dynamic changes of sound in three-dimensional space through the cooperation of algorithms and hardware devices; The interaural time difference (ITD) is characterized by the fact that when the sound source is located on one side of the listener, due to the difference in sound propagation paths, the sound will first reach the closer ear and then the farther ear. This time difference is called interaural time difference. The minimum time difference that the human ear can perceive is about 10 microseconds, which is one of the important bases for judging the direction of sound. The interaural sound pressure difference (ILD) is characterized by the fact that due to the obstruction and reflection of the sound propagation path and structures such as the head and auricle, the sound pressure of the same sound source when it reaches the left and right ears will be different. This difference is called the interaural sound pressure difference, which is also an important basis for judging the direction of the sound; The head-related transfer function (HRTF) is characterized in that HRTF describes the transmission process of sound from the sound source to the listener's ears, including effects such as reflection, diffraction and attenuation of sound on structures such as the head and auricle. By measuring and simulating HRTF, a three-dimensional audio effect similar to a real auditory experience can be generated.

[0015] The audio spatial audio algorithm uses the head motion data (including rotational angular velocity and acceleration) captured by the gyroscope to dynamically adjust the audio signal through a series of signal processing steps to simulate the three-dimensional spatial changes of the sound during the user's head movement. This algorithm is mainly based on the following mathematical models and signal processing technologies; Head motion model: θ(t), ϕ(t), and ψ(t) represent the yaw, pitch, and roll angles of the head at time t, respectively; the angular velocity ω(t) captured by the gyroscope is used to update the above angles in real time, calculated by the following integral relationship: θ(t)=θ(t−1)+ ; Used to calculate ϕ(t) and ψ(t); Audio spatial effect adjustment model: First, the head-related transfer function (HRTF) is used to simulate how sound is transmitted from the sound source to the ears at a specific head position and posture. Then, the HRTF parameters are dynamically updated according to the above head motion model. First, the angular velocity and acceleration data of the head movement are obtained from the gyroscope, and then the current posture angle of the head is calculated through numerical integration based on the angular velocity data; finally, the corresponding HRTF data set is called according to the updated head posture, and the audio signal is converted from the time domain to the frequency domain using FFT (Fast Fourier Transform), and HRTF is applied in the frequency domain to adjust the phase and amplitude of the audio signal to simulate the position change of the sound source relative to the user's head, and the processed signal is converted back to the time domain using IFFT (Inverse Fast Fourier Transform); the processed audio signal is output to the left and right channels of the headset to achieve spatial sound effects; The algorithm mainly involves obtaining gyroscope data, calculating head posture, calling head-related transfer function (HRTF), and applying this data to adjust the audio output, using the following basic pseudo code: start Get gyroscope data (angular velocity ωx, ωy, ωz) Initialize the head pose angles (θ, φ, ψ) to (0, 0, 0) Execute every time the data is updated: Calculate the time interval Δt Update the attitude angle: θ = θ + ωx * Δt φ = φ + ωy * Δt ψ = ψ + ωz * Δt Call HRTF(θ, φ, ψ) Apply HRTF data to adjust audio output: Calculate left and right ear channel signals Adjust the phase and amplitude of an audio signal Output adjusted audio to headphones Finish In the Bluetooth headset, when the user turns his head to the right, the algorithm will enhance the audio signal of the left ear and weaken the signal of the right ear accordingly, creating a sense of sound movement from left to right; the audio processing results will closely follow the user's head movements, providing real-time spatial audio feedback, and enhancing the immersion of applications such as virtual reality and augmented reality.

[0016] The above content is summarized as follows: The method for implementing spatial audio with gyroscope integration in the Bluetooth headset is characterized by a directional audio filter, which is a technology that can filter and enhance sounds from different directions. In the Bluetooth headset, by adding a directional audio filter, sounds from different directions can be distinguished and enhanced, thereby enhancing the sense of direction and space of the sound; The method for implementing spatial audio with gyroscope integration in the Bluetooth headset is characterized in that frequency fine-tuning is one of the important means to implement spatial audio technology. By adjusting the relative intensity of sounds of different frequencies in different ears, the distribution and movement of sounds in three-dimensional space can be simulated. This fine-tuning can be achieved through an audio processing algorithm, or it can be dynamically adjusted according to the user's head movements. The gyroscope integrated spatial audio implementation method in the Bluetooth headset is characterized by head-related transfer function (HRTF) simulation. HRTF simulation is one of the key steps in realizing spatial audio technology. By measuring and simulating HRTF, a three-dimensional audio effect similar to a real auditory experience can be generated. In the Bluetooth headset, HRTF simulation can be realized by a built-in audio processing chip or software; Compared with ordinary Bluetooth headsets, this invention innovatively integrates the gyroscope and spatial audio technology, overcoming many technical difficulties such as optimizing audio processing algorithms, improving sensor accuracy, and reducing power consumption. The application of this technology not only significantly enhances the user's immersive auditory experience, but also provides more realistic audio effects for scenes such as virtual reality and augmented reality. With the continuous development of technology and the expansion of application scenarios, spatial audio technology will continue to bring users richer functions and more convenient user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is a flowchart of spatial audio signal enhancement and modeling processing based on gyroscope for Bluetooth headsets.

[0018] Attached Figure 2 It is a flowchart of Bluetooth headsets based on real-time head tracking and dynamic adjustment of spatial audio.

[0019] Attached Figure 3 It is a schematic diagram of the system architecture for realizing spatial audio of Bluetooth headsets. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation examples.

[0021] The present invention provides a method for implementing spatial audio by integrating a gyroscope in a Bluetooth headset. The spatial audio adjustment method implemented by integrating a gyroscope provides an unprecedented audio experience for Bluetooth headset users, which is particularly suitable for virtual reality and augmented reality environments, and effectively improves the market competitiveness and technical level of the product.

[0022] Specifically, the Bluetooth headset is characterized in that it includes a gyroscope, four digital power amplifiers, an audio processing unit, and an MCU.

[0023] Embodiment 1:

[0024] When the user uses the headset to watch a virtual reality movie, the head turns to the right, and the gyroscope detects the change in rotation angle and transmits the data to the MCU. The MCU calls the corresponding HRTF parameters through the audio processing unit and dynamically adjusts the audio signal to increase the volume of the left ear and reduce the volume of the right ear, thus presenting a stereo sound effect in which the sound source position changes with the head movement.

[0025] The specific implementation steps are as follows: Combination Figure 1 and Figure 2 As shown, after the headset is turned on, connect it to the mobile device via Bluetooth, and press and hold the power button for 2 seconds when the music is paused to activate the spatial audio function.

[0026] In spatial audio mode, the gyroscope captures the user's head movement data in real time, including yaw, pitch and roll angles.

[0027] The MCU receives and processes the gyroscope data and calculates the current head posture angle (θ, ϕ, ψ) through numerical integration.

[0028] The HRTF data set is called according to the posture angle, and the audio signal is converted into the frequency domain using FFT. The phase and amplitude are adjusted in the frequency domain to simulate the change of the sound source position.

[0029] The adjusted audio signal is converted back to the time domain through IFFT and output to the left and right channels, ultimately presenting a real-time synchronized spatial sound effect.

[0030] The method for implementing spatial audio with gyroscope integration in the Bluetooth headset is characterized in that after the spatial audio is turned on, the gyroscope detects the user's head posture in real time. When the user changes the head posture, the MCU recognizes the change in the user's head posture through the gyroscope, and the MCU outputs a signal to the audio processor for audio output processing, thereby achieving different volume level changes for the left and right channels, thereby achieving the effect of three-dimensional spatial surround sound.

[0031] The gyroscope in the Bluetooth headset is a six-axis gyroscope chip, which is characterized in that the working principle of the six-axis gyroscope is based on microelectronic technology and mechanical principles; when an object undergoes linear acceleration or rotation, the gyroscope and the accelerometer will be subjected to corresponding forces; the gyroscope measures the rotational angular velocity of the object by detecting tiny vibrations, while the accelerometer measures the linear motion acceleration of the object by detecting gravitational acceleration and non-gravitational acceleration; The gyroscope usually uses piezoelectric materials or Hall elements to measure the rotational angular velocity of an object. When the object rotates, the gyroscope will generate a small displacement or electrical signal. The rotational angular velocity of the object can be obtained by processing these signals. In the Bluetooth headset, the integration of a gyroscope is crucial to the realization of spatial audio technology. The gyroscope can detect the user's head movements in real time, including rotation, tilt, etc.; by combining the gyroscope data with the audio processing algorithm, dynamic adjustment of the sound direction can be achieved, so that the sound always maintains a consistent relative position with the user's head.

[0032] Combination Figure 3As shown, in the Bluetooth headset, the digital power amplifier communicates with the MCU in full-duplex mode through IIC, characterized in that SCL and SDA are IIC interfaces connected to the MCU, and the MCU controls the opening and closing of the digital power amplifier through this IIC interface; the digital power amplifier amplifies the adjusted audio signal with high fidelity, and independently optimizes the output of medium-high frequency and low-frequency signals through frequency division design. The built-in power management module of the headset dynamically adjusts the power consumption according to the usage status, switches to low power consumption mode when the user is stationary, and quickly returns to full speed operation when the head moves, reducing power consumption by up to 30%.

[0033] Embodiment 2:

[0034] In long-term use environments, such as wearing headphones continuously to attend meetings or listen to music, the digital amplifier works in conjunction with the MCU to intelligently adjust power distribution through a dynamic power management system. When the user is stationary, the gyroscope enters low-power mode and only maintains basic monitoring; when head movement is detected, it quickly resumes full speed to ensure real-time and accurate audio adjustments. This design not only extends the battery life of the headphones, but also maintains consistency in sound quality.

[0035] Combination Figure 1 As shown, the gyroscope integrated spatial audio implementation method in the Bluetooth headset is characterized by an audio processing unit, which is an audio processing technology that can simulate the distribution and movement of sound in three-dimensional space. It uses the auditory characteristics of the human ear, such as interaural time difference (ITD), interaural sound pressure difference (ILD), head-related transfer function (HRTF), etc., and realizes the positioning and dynamic changes of sound in three-dimensional space through the cooperation of algorithms and hardware devices; The interaural time difference (ITD) is characterized by the fact that when the sound source is located on one side of the listener, due to the difference in sound propagation paths, the sound will first reach the closer ear and then the farther ear. This time difference is called interaural time difference. The minimum time difference that the human ear can perceive is about 10 microseconds, which is one of the important bases for judging the direction of sound. The interaural sound pressure difference (ILD) is characterized by the fact that due to the obstruction and reflection of the sound propagation path and structures such as the head and auricle, the sound pressure of the same sound source when it reaches the left and right ears will be different. This difference is called the interaural sound pressure difference, which is also an important basis for judging the direction of the sound; The head-related transfer function (HRTF) is characterized in that HRTF describes the transmission process of sound from the sound source to the listener's ears, including effects such as reflection, diffraction and attenuation of sound on structures such as the head and auricle. By measuring and simulating HRTF, a three-dimensional audio effect similar to a real auditory experience can be generated.

[0036] Through the above embodiments, the present invention significantly improves the immersive sound experience of Bluetooth headsets, while taking into account power consumption optimization and multi-scenario applicability, bringing users excellent auditory enjoyment.

[0037] The above is a specific description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments. Those skilled in the art may make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A Bluetooth headset, characterized in that: include: A gyroscope, used to capture the user's head motion data in real time, including rotational angular velocity and linear acceleration; An MCU is used to receive the data from the gyroscope and transmit it to the audio processing unit after processing; an audio processing unit is used to call the head-related transfer function (HRTF) algorithm according to the head movement data transmitted by the MCU to dynamically adjust the audio signals of the left and right channels; four digital amplifiers are used to amplify the signal output by the audio processing unit, divide the mid-high frequency and bass, and drive the speakers in the headphones to achieve high-fidelity spatial sound effects. An optimized power management module is used to dynamically adjust the power consumption according to the use status of the headphones to extend the battery life of the device.

2. The Bluetooth headset according to claim 1, characterized in that: The gyroscope is connected to the MCU via a serial communication interface, supporting full-duplex data transmission, and the MCU can dynamically control the working state of the gyroscope to reduce power consumption. The gyroscope is used to detect the user's head position and the user's head posture, and output corresponding signals to the MCU.

3. The Bluetooth headset according to claim 1, characterized in that: The audio processing unit further combines the Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) algorithms to achieve synchronous processing of the audio signal in the frequency domain and time domain, ensuring the dynamic consistency of the signal phase and amplitude.

4. The Bluetooth headset according to claim 1, characterized in that: The digital power amplifier supports high-fidelity audio signal amplification and significantly reduces power consumption through optimized power management design, while ensuring thermal stability and sound quality consistency of the headphones under long-term use.

5. The Bluetooth headset according to claim 3, characterized in that: The audio processing unit dynamically adjusts the delay and intensity of the audio signal based on the head-related transfer function (HRTF) model and combines the interaural time difference (ITD) and interaural sound pressure difference (ILD) algorithms to keep the audio signal synchronized with the user's head position in real time.

6. The Bluetooth headset according to claim 4, characterized in that: The sampling frequency of the gyroscope is not less than 1000 Hz, ensuring the accuracy and real-time nature of the head movement data collection. At the same time, the MCU further reduces the signal processing delay through the hardware acceleration algorithm.

7. The Bluetooth headset according to claim 1, characterized in that: The digital power amplifier supports high-fidelity audio signal amplification and has a frequency division design, which can independently optimize the output of mid-high frequency and low frequency signals to ensure consistency in sound quality.

8. The Bluetooth headset according to claim 5, characterized in that: The audio processing unit can dynamically switch audio processing parameters according to the user's usage scenario, including virtual reality mode and 3D surround sound mode.

9. The Bluetooth headset according to claim 1, characterized in that: The Bluetooth headset can effectively reduce the occupation of processing resources when running multiple tasks through an optimized algorithm processing framework, improve the overall operating efficiency, and adapt to a variety of consumer electronics scenarios.

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