Civil aviation large aircraft passenger seat intelligent headrest and method

Abstract

The application relates to the technical field of intelligent headrests, and provides a civil aviation large airplane passenger seat intelligent headrest and method, a headrest body, a noise collection module arranged in the headrest body and used for collecting noise of an environment and an ear and ear pressure values of the ear, a head movement tracking module assembled in the headrest body, precise positioning of ear hole center coordinates is realized by detecting a head contour, a contact state of the head and the headrest and a movement state of the head, a signal processing module internally provided with an ANC chip, and a control module used for acquiring ear hole center coordinate data obtained by the head movement tracking module. The application has the beneficial effects that the problems that a traditional civil aviation seat headrest only has a basic supporting function, is poor in engine low-frequency noise blocking effect of 50-500 Hz and is generally lower than 10 dB in noise reduction in dependence on passive sound insulation are solved, 35-40 dB of noise reduction depth is realized through active noise reduction technology, engine low-frequency roar of 80-1000 Hz and passenger conversation sound can be accurately filtered, and the low-frequency noise control effect is greatly improved.

Description

Technical Field

[0001] This invention belongs to the field of intelligent headrest technology, and specifically relates to an intelligent headrest and method for passenger seats in large civil aircraft. Background Technology

[0002] During the flight of large civil aircraft, cabin noise pollution has become one of the core pain points affecting the travel experience of passengers. This type of noise mainly includes low-frequency roaring of 50-500Hz generated by engine operation, airflow friction noise between the fuselage, high-frequency noise of 1-4kHz generated by passenger communication, and dynamic changes in the noise spectrum at different flight stages (takeoff, cruise, and landing). Long-term exposure can lead to passenger fatigue and ear pressure discomfort, seriously affecting the quality of rest and the long-distance travel experience.

[0003] Currently, traditional headrests in commercial airline seats only provide basic support and rely on materials such as high-density foam for simple passive sound insulation. Their effectiveness in blocking low-frequency noise is insufficient, with noise reduction generally below 10dB, and they cannot cope with dynamic changes in the noise spectrum. Existing active noise cancellation solutions mostly use independent noise-canceling headphones. While these can achieve some noise reduction, they suffer from problems such as ear pressure, poor comfort during extended use, and the need for manual mode switching. Furthermore, they cannot adapt to natural head movements, and noise cancellation accuracy drops significantly when the head shifts.

[0004] Meanwhile, existing aviation-specific noise reduction equipment has significant limitations: First, the noise reduction parameters are fixed and not specifically optimized to take into account the noise differences of different aircraft models and seating areas (such as near the engine or in the middle of the cabin); second, it lacks a head movement tracking mechanism, and the speaker's sound output direction cannot match the ear canal position in real time, resulting in unstable noise reduction effects; third, the equipment is inconvenient to clean and maintain, the fabric is not removable, and it is difficult to meet aviation hygiene standards; fourth, some equipment has high power consumption, insufficient battery life, and does not fully meet aviation safety certification requirements.

[0005] As civil aviation travel upgrades towards comfort and intelligence, passengers' demands for personalized and precise cabin noise reduction are increasing. Traditional headrests and independent noise reduction devices can no longer meet the needs of various scenarios. Therefore, developing a smart headrest for passenger seats on large civil aircraft that integrates active noise cancellation, head tracking, adaptive adjustment, and hygiene and convenience has become a key direction for solving aviation noise problems and improving the passenger travel experience. Summary of the Invention

[0006] In view of this, the present invention provides a smart headrest and method for passenger seats in civil aircraft. Through a closed-loop system of "collection-processing-cancellation", it can achieve precise control of low-frequency noise, effectively reduce noise, improve the noise reduction experience, support three-level mode adjustment to meet the needs of different scenarios, and can track head movement in real time and adjust the speaker angle to ensure the accuracy and stability of noise reduction and improve passenger comfort.

[0007] The technical solution is as follows: A smart headrest for passenger seats in large civil aircraft, comprising: The headrest body is designed to wrap around the head and extends to the area around the ears on both sides; The noise acquisition module, located inside the headrest, is used to collect ambient noise, noise around the ears, and ear pressure values ​​around the ears. The head motion tracking module is installed in the headrest body. By detecting the head contour, the contact state between the head and the headrest, and the movement state of the head, it can accurately locate the center coordinates of the ear canal. The signal processing module has an integrated ANC chip, which is connected to the aircraft's avionics system to receive real-time flight parameters. It also processes various signals from the noise acquisition module and head motion tracking module, generates reverse sound wave cancellation data, and can dynamically adjust the cancellation sound wave parameters according to the ear pressure value using a PID algorithm. The secondary sound source system includes adjustable speakers symmetrically arranged in the ear-shaped recesses of the headrest body, for outputting the reverse cancelling sound waves generated by the signal processing module; The control module is used to drive the adjustable speaker to adjust its angle according to the ear canal center coordinate data obtained by the head motion tracking module, so that its sound outlet is aligned with the ear canal; at the same time, it receives the ear pressure correction command from the signal processing module and adjusts the output amplitude of the adjustable speaker in conjunction.

[0008] Furthermore, the noise acquisition module includes an array of feedforward microphones symmetrically arranged on the outer side of the headrest body, a feedback microphone arranged in the ear-peripheral recess of the headrest body, and an ear pressure sensor embedded in the ear-peripheral recess; the feedforward microphone is a high-sensitivity MEMS sensor microphone used to acquire multi-source environmental noise in the cabin, the feedback microphone is used to acquire residual noise around the ear, and the ear pressure sensor is used to acquire the ear pressure value around the passenger's ear in real time; Preferably, both the feedforward microphone and the feedback microphone are mounted on the headrest body via shock-absorbing brackets to filter noise interference from headrest vibration and airflow. Both are equipped with dustproof nets to prevent dust and moisture from entering. The feedforward microphone has a frequency response range of 20Hz-20kHz and can collect low-frequency engine noise (50-500Hz), airflow noise, and high-frequency passenger conversation noise (1-4kHz). The feedback microphone is 5-8cm away from the ear and has a signal-to-noise ratio ≥65dB. The ear pressure sensor is ≤3cm away from the ear and has a sampling frequency ≥50Hz. When the detected ear pressure value exceeds a preset comfort threshold of ±2kPa, a signal is immediately sent to the ANC chip for parameter correction.

[0009] Furthermore, the head motion tracking module includes at least three infrared radar sensors arranged on the top and sides of the headrest body, a pressure sensor embedded in the headrest body, and a MEMS attitude sensor integrated into the positioning circuit. The infrared radar sensors are used to scan the passenger's head contour to obtain point cloud data, the pressure sensor is used to sense the contact posture and contact position between the head and the headrest, and the MEMS attitude sensor is used to detect the rotation, translation acceleration, and posture changes of the head. The data of the three are transmitted to the signal processing module, and the Kalman filter algorithm is used to fuse them to achieve accurate positioning of the ear canal center coordinates with a positioning response delay of ≤5ms.

[0010] Furthermore, the ANC chip has a built-in ADC analog-to-digital converter, FFT module, blind source separation algorithm module, Kalman filter algorithm module, PID algorithm module and LMS adaptive filtering algorithm, and a pre-stored civil aviation head posture feature library and a two-dimensional noise reduction parameter library for flight phase and ear position. Preferably, the reverse cancellation sound wave noise reduction depth can reach 35-40dB, focusing on filtering low-frequency engine roar and passenger conversations at 80-1000Hz, and supports three-level mode adjustment; More preferably, it also includes a Bluetooth module, which is integrated with the ANC chip to connect to external terminal devices and realize the custom adjustment of noise reduction intensity, noise reduction frequency band, and speaker angle. The custom parameters can be synchronously stored in the flash memory of the ANC chip. Preferably, the blind source separation algorithm module adopts the FastICA algorithm to separate the environmental noise collected by the feedforward microphone (1) in real time, and accurately identify the frequency band, amplitude and variation law of low-frequency engine noise, airflow noise and high-frequency passenger conversation noise; the ANC chip adopts a differentiated noise reduction strategy for different noise sources: the LMS adaptive filtering algorithm is used to generate reverse cancellation sound waves for 50-500Hz low-frequency steady-state engine noise, the predictive cancellation algorithm is used for non-steady-state airflow noise, and the dynamic threshold suppression algorithm is used for 1-4kHz high-frequency passenger conversation noise.

[0011] Furthermore, the two adjustable speakers are respectively connected to the headrest body (10) via a miniature dual-axis rotating mechanism, which is used to drive the adjustable speakers to rotate ±15° laterally and ±10° longitudinally.

[0012] Furthermore, the micro dual-axis rotating mechanism includes an installation cavity disposed between the outer shell of the headrest body and the composite filling layer. The installation cavity is fixed to the outer shell of the headrest body by buckles or screws. A first micro motor is bolted to the bottom surface of the installation cavity, and an arc-shaped frame is fixedly disposed at the output end of the first micro motor. An arc-shaped block is rotatably mounted inside the arc-shaped frame, and the adjustable speaker is mounted on the arc-shaped block. The center of the arc-shaped frame coincides with the center of the side of the adjustable speaker. When the first micro motor is activated, it drives the adjustable speaker to rotate laterally by ±15° through the arc-shaped frame and the arc-shaped block. An annular bracket is bolted to the upper end of the first micro motor, and an annular groove is formed on the annular bracket. A second bracket is rotatably mounted inside the annular groove, and a second micro motor is bolted to the second bracket. The output end of the second micro motor is connected and fixed to the center of the side of the adjustable speaker, and the second micro motor drives the adjustable speaker to rotate longitudinally by ±10°.

[0013] Furthermore, the headrest body adopts a wraparound arc design, extending 3-5cm to the ear area on both sides; Preferably, the headrest body includes a composite filling layer and is provided with a removable antibacterial fabric covering it. The composite filling layer is filled with high-density memory foam and porous sound-absorbing material. A pressure sensor is provided in the headrest body to sense the pressure of the composite filling layer and is electrically connected to the signal processing module. Preferably, the pressure sensor is electrically connected to the signal processing module to sense the pressure of the composite filling layer (8) and trigger the system to wake up automatically. The wake-up objects include the head motion tracking module, the noise acquisition module, the secondary sound source system, and the control module.

[0014] Furthermore, the civil aviation head posture feature library includes contour features, pressure distribution features, and posture motion features of typical head postures of civil aviation passengers, such as leaning forward, leaning to the left / right, head down, and head up. The ANC chip has a built-in lightweight deep learning MobileNet model, which is used to perform typical posture recognition on multi-sensor data after Kalman filtering algorithm fusion. Combined with ellipse fitting + radial range analysis method, it can predict and correct the ear canal center coordinates in real time with a positioning accuracy of ≤1mm. The civil aviation head posture feature library and MobileNet model are both fixed in the on-chip memory of the ANC chip, and the model has been lightweighted and trimmed, reducing computing power consumption by 60% and eliminating the need for an external computing power module.

[0015] Furthermore, the dual-dimensional noise reduction parameter library for flight phases and human ear positions is trained based on noise spectrum data, positioning data, and noise reduction effect data for different aircraft models, different flight phases, different human ear positions, and different seating areas, and is stored in the flash memory of the ANC chip. The flash memory reserves 10% of its storage space for storing real-time data during flight and can periodically update the model parameters via onboard WiFi. The ANC chip automatically switches the dimensional weights of the dual-dimensional noise reduction parameter library according to the real-time flight parameters of the aircraft's avionics system, achieving scenario-based intelligent matching of noise reduction parameters.

[0016] A noise reduction control method for a smart headrest for passenger seats in a large civil aircraft, characterized by comprising the following steps: The pressure sensor detects the contact pressure between the passenger's head and the headrest body. When the pressure value is greater than or equal to a preset threshold, the head motion tracking module, noise acquisition module, signal processing module, secondary sound source system and control module are automatically activated. The ANC chip of the signal processing module establishes communication with the aircraft avionics system to obtain real-time flight parameters such as aircraft model, flight stage, altitude, and thrust. Based on the flight parameters, the corresponding basic noise reduction parameter configuration scheme is preloaded from the dual-dimensional noise reduction parameter library of flight stage and human ear position. The head motion tracking module uses infrared radar sensors, pressure sensors, and MEMS attitude sensors to simultaneously collect head data, which is then transmitted to the ANC chip for fusion and noise reduction via Kalman filtering. The ANC chip calls upon the civil aviation head posture feature library and performs typical posture recognition using the MobileNet model. It combines ellipse fitting and radial range analysis to predict and correct the ear canal center coordinates in real time. Based on the ear canal center coordinate data, the control module drives a miniature dual-axis rotation mechanism to adjust the angle of the adjustable speaker so that the sound outlet is aligned with the ear canal. An array of feedforward microphones collects multi-source noise from the cabin environment, a feedback microphone collects residual noise around the ears, and an ear pressure sensor collects ear pressure values ​​around the ears in real time. Various analog signals are converted into 24-bit digital signals by an ADC analog-to-digital converter and then transmitted to the ANC chip. The blind source separation algorithm module realizes the real-time separation of low-frequency engine noise, airflow noise, and high-frequency noise from passenger conversations. The ANC chip employs differentiated noise reduction strategies for different noise sources after separation, generating reverse cancellation sound wave digital signals; at the same time, it dynamically adjusts the noise reduction parameters based on the residual noise data from the feedback microphone, and calculates the correction coefficient through the PID algorithm module based on the value of the ear pressure sensor, dynamically adjusting the output amplitude of the adjustable speaker to ensure that the ear pressure is maintained within the comfortable threshold range. The ANC chip converts the digital signal of the reverse cancellation sound wave into an analog signal and transmits it to the adjustable speaker. The speaker outputs the reverse cancellation sound wave, which is superimposed on the cabin ambient noise to achieve precise noise reduction. The head motion tracking module continuously collects head motion data and updates the ear canal center coordinates in real time. The control module adjusts the angle of the adjustable speaker in conjunction with the head motion tracking module. The ANC chip continuously receives flight parameters from the aircraft's avionics system and signals from the noise acquisition module. It switches the weights of the dual-dimensional noise reduction parameter library in real time and dynamically adjusts the differentiated noise reduction strategy to achieve adaptive and precise noise reduction throughout the entire flight process.

[0017] After adopting the above technical solution, the beneficial effects of this invention are as follows: Addressing the technical shortcomings of noise pollution in the cabins of large civil aircraft, traditional headrests, and existing noise reduction equipment, it achieves multiple beneficial effects: First, it solves the problems of traditional civil aircraft seat headrests only providing basic support, relying on passive sound insulation for poor blocking of 50-500Hz engine low-frequency noise, and generally having a noise reduction effect of less than 10dB. Through active noise cancellation technology, it achieves a noise reduction depth of 35-40dB, accurately filtering 80-1000Hz engine low-frequency roar and passenger conversations, significantly improving low-frequency noise control. Second, it solves the problems of existing independent noise-canceling headphones causing ear pressure, poor comfort during prolonged use, and the need for manual mode switching. This headrest is integrated with the seat, eliminating the need for additional headphones, and can automatically wake the system through a pressure sensor. Combined with three noise cancellation modes and Bluetooth custom adjustment, it balances ease of use and wearing comfort. Third, it solves the problems of existing aviation noise cancellation equipment lacking a head movement tracking mechanism and having speaker output directions that cannot match the ears. The problem of significantly reduced noise reduction accuracy due to ear canal position and head displacement is addressed by using a head motion tracking module with multi-sensor fusion to accurately locate the center coordinates of the ear canal. This, combined with a control module driving an adjustable speaker to adjust its angle in real time, ensures that the canceling sound waves always act precisely around the ear, maintaining a stable noise reduction effect even after head movement. Fourth, it solves the problem of fixed noise reduction parameters in existing noise reduction devices, which lack targeted optimization based on different aircraft models, flight stages, and seat area noise differences. Through communication between the ANC chip and the aircraft's avionics system, and combining a dual-dimensional noise reduction parameter library based on flight stage and ear position, it achieves scenario-based intelligent matching of noise reduction parameters, adapting to the dynamic changes in noise in different flight scenarios. Fifth, it addresses the problem of existing noise reduction solutions causing ear pressure discomfort and affecting the long-haul flight experience due to excessive cancellation of reverse sound waves. By using an ear pressure sensor to collect periauricular pressure values ​​in real time and combining it with a PID algorithm to dynamically adjust the canceling sound wave parameters, it achieves a synergy between noise reduction effect and ear pressure comfort, completely resolving ear pressure pain points during long-haul flights. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the process of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention; Figure 3 This is a schematic diagram of the structure of the miniature dual-axis rotation mechanism of the present invention; Figure 4 This is a practical effect diagram of the present invention; In the diagram, 1. Feedforward microphone; 2. Feedback microphone; 3. Dustproof mesh; 4. Signal processing module; 5. Infrared radar sensor; 6. Adjustable speaker; 7. Wrap-up arc design; 8. Composite filling layer; 9. Miniature dual-axis rotation mechanism; 91. Mounting cavity; 92. First micro motor; 93. Arc frame; 94. Arc block; 95. Ring frame; 96. Second bracket; 97. Second micro motor; 10. Headrest body; Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0021] like Figures 1 to 4 As shown, a smart headrest for passenger seats in a large civil aircraft includes: a headrest body 10 for wrapping the head and extending to the ear area on both sides; a noise acquisition module, located within the headrest body 10, for collecting ambient noise, noise around the ears, and ear pressure values; a head motion tracking module, installed within the headrest body 10, for accurately locating the center coordinates of the ear canal by detecting the head contour, the contact state between the head and the headrest, and the head motion state; and a signal processing module 4, which includes an ANC chip. The ANC chip is communicatively connected to the aircraft's avionics system to receive real-time flight parameters and process data from the noise acquisition module and the headrest body 10. The head motion tracking module generates reverse sound wave cancellation data from various signals and can dynamically adjust the cancellation sound wave parameters according to the ear pressure value using a PID algorithm. The secondary sound source system includes an adjustable speaker 6 symmetrically arranged in the ear-peripheral recess of the headrest body 10, used to output the reverse cancellation sound wave generated by the signal processing module 4. The control module is used to drive the adjustable speaker 6 to adjust its angle according to the ear canal center coordinate data obtained by the head motion tracking module, so that its sound outlet is aligned with the ear canal. At the same time, it receives the ear pressure correction command from the signal processing module 4 and adjusts the output amplitude of the adjustable speaker 6 accordingly.

[0022] In one specific implementation, the noise acquisition module and the head motion tracking module are both electrically connected to the signal processing module 4 to achieve real-time transmission of the detection signal; the signal processing module 4 is electrically connected to the control module and the secondary sound source system, and can synchronously send the processed control commands to the control module and the secondary sound source system; the control module is connected to the adjustable speaker 6 of the secondary sound source system, and can precisely drive the speaker to complete the angle and amplitude adjustment. The coordinated work of all modules is coordinated by the ANC chip as the core control unit to ensure the synchronization and accuracy of the overall operation. Specifically, the noise acquisition module simultaneously collects cabin ambient noise, residual noise around the passenger's ears, and real-time ear pressure values. The head movement tracking module simultaneously detects the passenger's head contour, the contact state between the head and the headrest (e.g., leaning forward or sideways), and the head movement state (e.g., rotation or translation). Both modules transmit the collected analog signals to the signal processing module 4 in real time. The ANC chip in the signal processing module 4 first converts the analog signals into digital signals and simultaneously receives real-time flight parameters (e.g., flight phase, thrust, altitude) transmitted from the aircraft avionics system. After analyzing and processing the head tracking data, it achieves precise positioning of the ear canal center coordinates. After parsing the noise data, it generates reverse sound wave cancellation data. If the detected ear pressure value exceeds the preset comfort range, it will also calculate the parameter correction value for canceling the sound waves through a PID algorithm. The ANC chip will then transmit the reverse sound wave data to the signal processing module 4. The sound wave cancellation data is sent to the secondary sound source system. After receiving the data, the adjustable speaker 6 outputs a reverse cancellation sound wave, which is superimposed on the cabin ambient noise to achieve active noise cancellation. At the same time, the control module drives the adjustable speaker 6 to adjust the sound output angle based on the positioning data of the head motion tracking module, ensuring that the sound outlet is accurately aligned with the passenger's ear canal, so that the reverse cancellation sound wave can act on the periauricular area to the maximum extent. During the noise reduction process, the head motion tracking module continuously collects head position change data, and the control module adjusts the speaker angle in real time to ensure the accuracy of positioning and sound output. If the ear pressure sensor detects abnormal ear pressure, the ANC chip dynamically adjusts the reverse sound wave cancellation parameters through the PID algorithm, and the control module synchronously adjusts the output amplitude of the speaker to maintain the ear pressure within a comfortable range while ensuring the noise reduction effect, achieving a dynamic balance between noise reduction and ear pressure comfort.

[0023] Therefore, the reverse cancellation sound waves generated by active noise cancellation technology can achieve a noise reduction depth of 35-40dB, effectively filtering out low-frequency engine noise and passenger conversations in the 80-1000Hz range, thus significantly reducing cabin noise interference to passengers. The head motion tracking module can accurately locate the center coordinates of the ear canals, and the control module drives the adjustable speaker 6 to adjust its angle in real time. Even if the passenger's head undergoes natural movements such as rotation or translation, the noise reduction "quiet zone" can synchronously follow the position of the ear canals, maintaining a stable noise reduction effect at all times. There are no blind spots in noise reduction; the ANC chip is linked with the aircraft's avionics system and can automatically adjust the noise reduction strategy according to the noise characteristics of different flight stages such as takeoff, cruise, and landing, adapting to the dynamic changes in cabin noise in civil aviation, and achieving intelligent and stable noise reduction throughout the entire flight process from takeoff to landing; all modules are integrated into the headrest body 10, with a compact structure and high compatibility with the installation of passenger seats in large civil aircraft, and all modules form a closed-loop working system with strong synchronization of signal transmission and command execution, and can still operate stably in the vibration and electromagnetic environment of aircraft flight, meeting the usage requirements of civil aviation equipment.

[0024] Furthermore, the noise acquisition module includes an array of feedforward microphones 1 symmetrically arranged on the outer side of the headrest body 10, a feedback microphone 2 arranged in the ear-peripheral recess of the headrest body 10, and an ear pressure sensor embedded in the ear-peripheral recess; the feedforward microphone 1 is a high-sensitivity MEMS sensor microphone used to acquire multi-source environmental noise in the cabin, the feedback microphone 2 is used to acquire residual noise around the ear, and the ear pressure sensor is used to acquire the ear pressure value around the passenger's ear in real time; Preferably, both the feedforward microphone 1 and the feedback microphone 2 are mounted on the headrest body 10 via shock-absorbing brackets to filter noise interference caused by headrest vibration and airflow. Both are equipped with dustproof nets 3 to prevent dust and moisture from entering. The feedforward microphone 1 has a frequency response range of 20Hz-20kHz and can collect low-frequency engine noise (50-500Hz), airflow noise, and high-frequency noise from passenger conversations (1-4kHz). The feedback microphone 2 is located 5-8cm from the auricle and has a signal-to-noise ratio ≥65dB. The ear pressure sensor is ≤3cm from the auricle and has a sampling frequency ≥50Hz. When the detected ear pressure value exceeds the preset comfort threshold of ±2kPa, it immediately sends a signal to the ANC chip for parameter correction.

[0025] Furthermore, the head motion tracking module includes at least three infrared radar sensors 5 arranged on the top and sides of the headrest body 10, a pressure sensor embedded in the headrest body 10, and a MEMS attitude sensor integrated into the positioning circuit. The infrared radar sensors 5 are used to scan the contour of the passenger's head to obtain point cloud data, the pressure sensor is used to sense the contact posture and contact position between the head and the headrest, and the MEMS attitude sensor is used to detect the rotation, translation acceleration, and posture changes of the head. The data of the three are transmitted to the signal processing module 4, and the Kalman filter algorithm is used to fuse them to achieve accurate positioning of the ear canal center coordinates with a positioning response delay of ≤5ms.

[0026] The noise acquisition module employs a combination of an array-type feedforward microphone 1, a feedback microphone 2, and an ear pressure sensor. The array-type feedforward microphone 1 is symmetrically arranged on the outside of the headrest body 10, providing comprehensive coverage of the cabin space. Utilizing the hardware characteristics of high-sensitivity MEMS sensor microphones, it achieves comprehensive acquisition of multi-source environmental noise within the cabin. The feedback microphone 2 is precisely positioned in the ear-peripheral recess of the headrest body 10, allowing for close-range acquisition of residual noise around the passenger's ears. This provides accurate peripheral noise data for the dynamic correction of subsequent noise reduction parameters. The ear pressure sensor is also embedded in the ear-peripheral recess, forming a combination with the feedback microphone 2. The periauricular detection system enables real-time acquisition of ear pressure values. To adapt to the operating environment of civil aviation cabins, such as fuselage vibration, airflow disturbance, and dust and moisture, both the feedforward microphone 1 and the feedback microphone 2 are mounted on the headrest body 10 via shock-absorbing brackets. The buffering characteristics of the shock-absorbing brackets filter out the noise interference caused by the vibration of the headrest body 10 during aircraft flight and the airflow in the cabin, ensuring the purity of the noise signal collected by the microphones. At the same time, a dustproof net 3 is set at the microphone acquisition end to effectively prevent dust and moisture from entering the microphone, thereby improving the service life and operational stability of the module and meeting the long-term use requirements of civil aviation equipment. In this module, the feedforward microphone 1 has a wide frequency response range of 20Hz-20kHz, which can accurately capture low-frequency engine noise (50-500Hz), airflow noise, and high-frequency passenger conversation noise (1-4kHz) in the civil aviation cabin, achieving full coverage of the main noise sources in the cabin. The feedback microphone 2 maintains a reasonable distance of 5-8cm from the passenger's auricle, and has a signal-to-noise ratio of ≥65dB, ensuring the accuracy of the acquisition while avoiding direct contact with the passenger's ear. The ear pressure sensor is ≤3cm away from the auricle, with a sampling frequency of ≥50Hz, which can quickly and accurately capture changes in periauricular pressure. When the detected ear pressure value exceeds the preset comfort threshold of ±2kPa, it can immediately send a parameter correction signal to the ANC chip, providing real-time and accurate detection data support for ear pressure adaptive correction. This module, through the rational deployment of multiple types of detection elements and hardware characteristic adaptation, solves the technical problems of traditional noise acquisition equipment being easily affected by vibration and airflow interference in civil aviation cabins, leading to signal distortion, and the inability of a single acquisition element to simultaneously detect environmental noise, residual noise, and ear pressure. It also addresses the pain point specific to long-haul civil aviation flights where the lack of real-time ear pressure detection in existing noise reduction solutions can cause excessive cancellation of reverse sound waves, resulting in ear pressure discomfort for passengers. This module achieves accurate and comprehensive noise signal acquisition and real-time ear pressure monitoring, laying a data foundation for subsequent differentiated noise reduction and ear pressure closed-loop correction. In practical applications, it effectively improves the accuracy and completeness of noise acquisition, reduces the impact of clutter interference on noise reduction effects, and the real-time ear pressure detection makes the noise reduction process more aligned with human comfort needs, completely resolving the contradiction between active noise cancellation and ear pressure comfort.

[0027] The head motion tracking module consists of at least three infrared radar sensors 5, a pressure sensor, and a MEMS attitude sensor. The infrared radar sensors 5 are arranged on the top and sides of the headrest body 10, forming an all-round head scanning layout with no blind spots. It can quickly scan the passenger's head contour and obtain accurate head point cloud data. The pressure sensor is embedded inside the headrest body 10 and can sense the contact posture and contact position between the passenger's head and the headrest in real time, and determine the contact state such as head leaning forward or sideways. The MEMS attitude sensor is integrated into the positioning circuit and can accurately detect the passenger's head rotation, translation acceleration, and posture changes, and capture the dynamic movement trajectory of the head. The three types of sensors collect head-related data from three dimensions: head contour, contact state, and dynamic movement, and transmit all data synchronously to the signal processing module 4. The ANC chip uses a Kalman filter algorithm to fuse the multi-source data, filter out interference errors in the data, and achieve accurate positioning of the passenger's ear canal center coordinates. The positioning response delay is ≤5ms, which can quickly adapt to the natural movement of the passenger's head. This module solves the technical problems of blind spots, low positioning accuracy, and inability to accurately capture head dynamics in existing aviation noise reduction equipment by using multi-sensor collaborative detection and algorithm fusion processing. It also addresses the core pain point that the speaker's sound output direction cannot match the ear canal position in time due to head positioning lag and insufficient accuracy, resulting in a significant drop in noise reduction accuracy after head displacement. In practical applications, thanks to multi-dimensional sensor data acquisition and efficient algorithm fusion, it achieves high-precision and high-response speed positioning of the ear canal center coordinates. Even if the passenger's head rotates or translates naturally, it can quickly capture position changes and complete positioning, providing accurate position data for the control module to drive the adjustable speaker 6 to adjust its angle in real time. This ensures that the speaker's sound output is always aligned with the ear canal, allowing the noise reduction "quiet zone" to move synchronously with head movement, effectively guaranteeing the stability and accuracy of noise reduction during head movement, and meeting the usage needs of civil aviation passengers during natural head movements during flight.

[0028] The noise acquisition module and head motion tracking module, as the core detection units of the smart headrest, work together to provide accurate noise, ear pressure, and head position data for active noise cancellation. This provides a real, accurate, and real-time data foundation for the subsequent differentiated noise cancellation, flight scenario adaptation, and ear pressure adaptive correction of the signal processing module 4, as well as the precise execution of the control module. This effectively makes up for the problems of singleness, lag, and inaccuracy in the detection process of existing aviation noise cancellation equipment, making the entire active noise cancellation system more in line with the usage scenarios of large civil aircraft cabins and the actual needs of passengers. It improves the noise cancellation effect and user experience of the smart headrest from the source of detection.

[0029] Furthermore, the ANC chip has a built-in ADC analog-to-digital converter, FFT module, blind source separation algorithm module, Kalman filter algorithm module, PID algorithm module and LMS adaptive filtering algorithm, and a pre-stored civil aviation head posture feature library and a two-dimensional noise reduction parameter library for flight phase and ear position. Preferably, the reverse cancellation sound wave noise reduction depth can reach 35-40dB, focusing on filtering low-frequency engine roar and passenger conversations at 80-1000Hz, and supports three-level mode adjustment; More preferably, it also includes a Bluetooth module, which is integrated with the ANC chip to connect to external terminal devices and realize the custom adjustment of noise reduction intensity, noise reduction frequency band, and speaker angle. The custom parameters can be synchronously stored in the flash memory of the ANC chip. Preferably, the blind source separation algorithm module adopts the FastICA algorithm to separate the environmental noise collected by the feedforward microphone 1 (1) in real time, and accurately identify the frequency band, amplitude and variation law of low-frequency engine noise, airflow noise and high-frequency passenger conversation noise; the ANC chip adopts a differentiated noise reduction strategy for different noise sources: the LMS adaptive filtering algorithm is used to generate reverse cancellation sound waves for 50-500Hz engine low-frequency steady-state noise, the predictive cancellation algorithm is used for airflow non-steady-state noise, and the dynamic threshold suppression algorithm is used for 1-4kHz passenger conversation high-frequency noise.

[0030] Furthermore, the two adjustable speakers 6 are respectively connected to the headrest body 10 via a miniature dual-axis rotating mechanism 9, which is used to drive the adjustable speakers 6 to rotate ±15° laterally and ±10° longitudinally.

[0031] Furthermore, the miniature dual-axis rotating mechanism 9 includes a mounting cavity 91 disposed between the outer shell of the headrest body 10 and the composite filling layer 8. The mounting cavity 91 is fixed to the outer shell of the headrest body 10 by clips or screws. A first miniature motor 92 is bolted to the bottom surface inside the mounting cavity 91, and an arc-shaped frame 93 is fixedly disposed at the output end of the first miniature motor 92. An arc-shaped block 94 is rotatably mounted inside the arc-shaped frame 93, and the adjustable speaker 6 is mounted on the arc-shaped block 94. The center of the arc-shaped frame 93 is aligned with the center of the side of the adjustable speaker 6. When the positions coincide, the first micro motor 92 is activated, which drives the adjustable speaker 6 to rotate laterally by ±15° through the arc frame 93 and the arc block 94. The upper end of the first micro motor 92 is bolted to a ring bracket, and the ring bracket has an annular groove. The second bracket 96 is rotatably installed in the annular groove. The second micro motor 97 is bolted to the second bracket 96. The output end of the second micro motor 97 is connected and fixed to the center position of the side of the adjustable speaker 6. The second micro motor 97 drives the adjustable speaker 6 to rotate longitudinally by ±10°.

[0032] Specifically, in the miniature dual-axis rotating mechanism 9, the first miniature motor 92 is activated, and its output drives the arc-shaped frame 93 and the arc-shaped block 94 to rotate synchronously, enabling the adjustable speaker 6 to rotate horizontally by ±15°. At this time, the adjustable speaker 6 drives the second miniature motor 97 to rotate around the ring support. The second miniature motor 97 is activated, and its output is connected to the adjustable speaker 6, driving the adjustable speaker 6 to rotate vertically by ±10°. The two motors work together, allowing the speaker to adjust its angle independently in both horizontal and vertical degrees of freedom. This mechanism has a sophisticated structure that can precisely control the speaker angle, ensuring that its sound outlet is always aligned with the ear canal, improving the noise reduction effect. Moreover, the two degrees of freedom can be adjusted independently, providing high flexibility and adapting to different passenger head postures. The chip converts the reverse cancelling sound wave digital signal into an analog signal through the built-in digital-to-analog converter and transmits it synchronously to the adjustable speakers on both sides. At the same time, it continuously receives head position data from the infrared radar sensor 5 and adjusts the output angle parameters of the speaker accordingly to ensure that the cancelling sound wave always acts accurately around the ear.

[0033] Furthermore, the headrest body 10 adopts a wrap-around arc design 7, extending 3-5cm to the ear area on both sides; Preferably, the headrest body 10 includes a composite filling layer 8 and is provided with a removable antibacterial fabric. The composite filling layer 8 is filled with high-density memory foam and porous sound-absorbing material. A pressure sensor is provided inside the headrest body 10 to sense the pressure of the composite filling layer 8 and is electrically connected to the signal processing module 4. Preferably, the pressure sensor is electrically connected to the signal processing module 4 to sense the pressure of the composite filling layer 8 and trigger the system to automatically wake up. The wake-up objects include the head motion tracking module, the noise acquisition module, the secondary sound source system, and the control module.

[0034] Furthermore, the civil aviation head posture feature library includes contour features, pressure distribution features, and posture motion features of typical head postures of civil aviation passengers, such as leaning forward, leaning to the left / right, head down, and head up. The ANC chip has a built-in lightweight deep learning MobileNet model, which is used to perform typical posture recognition on multi-sensor data after Kalman filtering algorithm fusion. Combined with ellipse fitting + radial range analysis method, it can predict and correct the ear canal center coordinates in real time with a positioning accuracy of ≤1mm. The civil aviation head posture feature library and MobileNet model are both fixed in the on-chip memory of the ANC chip, and the model has been lightweighted and trimmed, reducing computing power consumption by 60% and eliminating the need for an external computing power module.

[0035] Furthermore, the dual-dimensional noise reduction parameter library for flight phases and human ear positions is trained based on noise spectrum data, positioning data, and noise reduction effect data for different aircraft models, different flight phases, different human ear positions, and different seating areas, and is stored in the flash memory of the ANC chip. The flash memory reserves 10% of its storage space for storing real-time data during flight and can periodically update the model parameters via onboard WiFi. The ANC chip automatically switches the dimensional weights of the dual-dimensional noise reduction parameter library according to the real-time flight parameters of the aircraft's avionics system, achieving scenario-based intelligent matching of noise reduction parameters.

[0036] A noise reduction control method for a smart headrest for passenger seats in a large civil aircraft, characterized by comprising the following steps: The pressure sensor detects the contact pressure between the passenger's head and the headrest body 10. When the pressure value is greater than or equal to a preset threshold, the head motion tracking module, noise acquisition module, signal processing module 4, secondary sound source system and control module are automatically activated. The ANC chip of signal processing module 4 establishes communication with the aircraft avionics system to obtain real-time flight parameters such as aircraft model, flight stage, altitude, and thrust. Based on the flight parameters, it preloads the corresponding basic noise reduction parameter configuration scheme from the dual-dimensional noise reduction parameter library of flight stage and human ear position. The infrared radar sensor 5, pressure sensor, and MEMS attitude sensor of the head motion tracking module synchronously collect head data and transmit it to the ANC chip for fusion and noise reduction through Kalman filtering algorithm. The ANC chip calls the civil aviation human head attitude feature library, performs typical attitude recognition through MobileNet model, and combines ellipse fitting and radial range analysis to realize the prediction and real-time correction of the ear canal center coordinates. The control module drives the micro dual-axis rotation mechanism 9 to drive the adjustable speaker 6 to adjust the angle so that the sound outlet is aligned with the ear canal according to the ear canal center coordinate data. An array-type feedforward microphone 1 collects multi-source noise from the cabin environment, a feedback microphone 2 collects residual noise around the ears, and an ear pressure sensor collects ear pressure values ​​around the ears in real time. Various analog signals are converted into 24-bit digital signals by an ADC analog-to-digital converter and then transmitted to the ANC chip. The blind source separation algorithm module realizes the real-time separation of low-frequency engine noise, airflow noise, and high-frequency noise from passenger conversations. The ANC chip employs differentiated noise reduction strategies for different noise sources after separation, generating reverse cancellation sound wave digital signals; at the same time, it dynamically adjusts the noise reduction parameters based on the residual noise data of the feedback microphone 2, and calculates the correction coefficient through the PID algorithm module based on the value of the ear pressure sensor, dynamically adjusting the output amplitude of the adjustable speaker 6 to ensure that the ear pressure is maintained within the comfortable threshold range. The ANC chip converts the digital signal of the reverse cancellation sound wave into an analog signal and transmits it to the adjustable speaker 6. The speaker outputs the reverse cancellation sound wave and superimposes it with the cabin environment noise to achieve precise noise reduction. The head motion tracking module continuously collects head motion data and updates the ear canal center coordinates in real time. The control module adjusts the 6-angle adjustable speaker in conjunction with the head motion tracking module. The ANC chip continuously receives flight parameters from the aircraft's avionics system and signals from the noise acquisition module. It switches the weights of the dual-dimensional noise reduction parameter library in real time and dynamically adjusts the differentiated noise reduction strategy to achieve adaptive and precise noise reduction throughout the entire flight process.

[0037] Addressing the noise pollution in the cabins of large civil aircraft and the technical shortcomings of traditional headrests and existing noise reduction equipment, this product overcomes the problems of traditional civil aircraft seat headrests providing only basic support, relying on passive sound insulation for poor blocking of low-frequency engine noise in the 50-500Hz range, and generally achieving noise reduction levels below 10dB. It utilizes active noise cancellation technology to achieve a noise reduction depth of 35-40dB, accurately filtering low-frequency engine roar and passenger conversations in the 80-1000Hz range, significantly improving low-frequency noise control. Simultaneously, it solves the problems of existing independent noise-canceling headphones causing ear pressure, poor comfort during prolonged use, and the need for manual mode switching. This headrest is integrated with the seat, eliminating the need for additional headphones, and automatically activates the system via a pressure sensor. Combined with three noise reduction modes and Bluetooth customization, it balances ease of use and wearing comfort. Furthermore, it addresses the lack of head movement tracking mechanisms in existing aviation noise reduction equipment, the inability of speaker output direction to match ear canal position, and the significant decrease in noise reduction accuracy after head displacement. To address the issue of noise reduction, a multi-sensor fusion head motion tracking module is used to accurately locate the center coordinates of the ear canal. This, combined with a control module, drives an adjustable speaker 6 to adjust its angle in real time, ensuring that the canceling sound waves always act precisely around the ear, maintaining a stable noise reduction effect even after head movement. Furthermore, to solve the problem of fixed noise reduction parameters in existing noise reduction devices and the lack of targeted optimization based on different aircraft models, flight stages, and seat area noise differences, an ANC chip communicates with the aircraft's avionics system. By combining a dual-dimensional noise reduction parameter library based on flight stage and ear position, scenario-based intelligent matching of noise reduction parameters is achieved, adapting to the dynamic changes in noise in different flight scenarios. Finally, to address the issue of existing noise reduction solutions causing ear pressure discomfort and affecting the long-haul flight experience due to excessive cancellation of reverse sound waves, an ear pressure sensor collects the periauricular pressure value in real time and dynamically adjusts the canceling sound wave parameters using a PID algorithm, achieving a synergy between noise reduction effect and ear pressure comfort, completely resolving ear pressure pain points during long-haul flights.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope. All such changes and modifications fall within the scope of the present invention as claimed, which is defined by the appended claims and their equivalents.

Claims

1. A smart headrest for passenger seats in large civil aircraft, characterized in that, include: The headrest body (10) is used to wrap the head and extends to the ear area on both sides; The noise acquisition module is located inside the headrest body (10) and is used to collect ambient noise, noise around the ear, and ear pressure values ​​around the ear. The head motion tracking module is installed inside the headrest body (10). By detecting the head contour, the contact state between the head and the headrest, and the movement state of the head, it can accurately locate the center coordinates of the ear canal. The signal processing module (4) is equipped with an ANC chip. The ANC chip is connected to the aircraft avionics system to receive real-time flight parameters, process various signals from the noise acquisition module and head motion tracking module, generate reverse sound wave cancellation data, and can dynamically adjust the cancellation sound wave parameters according to the ear pressure value through the PID algorithm. The secondary sound source system includes an adjustable speaker (6) symmetrically arranged in the ear-shaped recess of the headrest body (10) for outputting the reverse canceling sound wave generated by the signal processing module (4); The control module is used to drive the adjustable speaker (6) to adjust its angle according to the ear canal center coordinate data obtained by the head motion tracking module so that its sound outlet is aligned with the ear canal; at the same time, it receives the ear pressure correction command from the signal processing module (4) and adjusts the output amplitude of the adjustable speaker (6) in conjunction.

2. The intelligent headrest for passenger seats in large civil aircraft according to claim 1, characterized in that, The noise acquisition module includes an array of feedforward microphones (1) symmetrically arranged on the outside of the headrest body (10), a feedback microphone (2) arranged in the ear recess of the headrest body (10), and an ear pressure sensor embedded in the ear recess; the feedforward microphone (1) is a high-sensitivity MEMS sensor microphone used to collect multi-source environmental noise in the cabin, the feedback microphone (2) is used to collect residual noise around the ear, and the ear pressure sensor is used to collect the ear pressure value around the passenger's ear in real time; Preferably, the feedforward microphone (1) and the feedback microphone (2) are both mounted on the headrest body (10) via a shock-absorbing bracket to filter out noise interference caused by headrest vibration and airflow. Both are equipped with dustproof nets (3) to prevent dust and moisture from entering. The feedforward microphone (1) has a frequency response range of 20Hz-20kHz and can collect low-frequency engine noise, airflow noise and high-frequency noise of passenger communication at 50-500Hz. The feedback microphone (2) is 5-8cm away from the auricle and has a signal-to-noise ratio of ≥65dB. The ear pressure sensor is ≤3cm away from the auricle and has a sampling frequency of ≥50Hz. When the ear pressure value exceeds the preset comfort threshold of ±2kPa, it immediately sends a signal to the ANC chip for parameter correction.

3. The intelligent headrest for passenger seats in large civil aircraft according to claim 1, characterized in that, The head motion tracking module includes at least three infrared radar sensors (5) arranged on the top and sides of the headrest body (10), a pressure sensor embedded in the headrest body (10), and a MEMS attitude sensor integrated into the positioning circuit. The infrared radar sensors (5) are used to scan the contour of the passenger's head to obtain point cloud data. The pressure sensor is used to sense the contact posture and contact position between the head and the headrest. The MEMS attitude sensor is used to detect the rotation, translation acceleration and posture changes of the head. The data of the three are transmitted to the signal processing module (4), and the Kalman filter algorithm is used to fuse them to achieve accurate positioning of the ear hole center coordinates. The positioning response delay is ≤5ms.

4. The intelligent headrest for passenger seats in large civil aircraft according to claim 1, characterized in that, The ANC chip has a built-in ADC analog-to-digital converter, FFT module, blind source separation algorithm module, Kalman filter algorithm module, PID algorithm module and LMS adaptive filtering algorithm, and a pre-stored civil aviation human head posture feature library and a two-dimensional noise reduction parameter library for flight phase and human ear position. Preferably, the reverse cancellation sound wave noise reduction depth can reach 35-40dB, focusing on filtering low-frequency engine roar and passenger conversations at 80-1000Hz, and supports three-level mode adjustment; More preferably, it also includes a Bluetooth module, which is integrated with the ANC chip to connect to external terminal devices and realize the custom adjustment of noise reduction intensity, noise reduction frequency band, and speaker angle. The custom parameters can be synchronously stored in the flash memory of the ANC chip. Preferably, the blind source separation algorithm module adopts the FastICA algorithm to separate the environmental noise collected by the feedforward microphone (1) in real time, and accurately identify the frequency band, amplitude and variation law of low-frequency engine noise, airflow noise and high-frequency passenger conversation noise; the ANC chip adopts a differentiated noise reduction strategy for different noise sources: the LMS adaptive filtering algorithm is used to generate reverse cancellation sound waves for 50-500Hz low-frequency steady-state engine noise, the predictive cancellation algorithm is used for non-steady-state airflow noise, and the dynamic threshold suppression algorithm is used for 1-4kHz high-frequency passenger conversation noise.

5. The intelligent headrest for passenger seats in large civil aircraft according to claim 1, characterized in that, The two adjustable speakers (6) are respectively connected to the headrest body (10) via a miniature dual-axis rotating mechanism (9) to drive the adjustable speakers (6) to rotate ±15° laterally and ±10° longitudinally.

6. The miniature dual-axis rotating mechanism (9) includes an installation cavity (91) disposed between the outer shell and the composite filling layer of the headrest body (10). The installation cavity (91) is fixed to the outer shell of the headrest body (10) by a buckle or screw. A first miniature motor (92) is bolted to the bottom surface inside the installation cavity (91), and an arc-shaped frame (93) is fixedly disposed at the output end of the first miniature motor (92). An arc-shaped block (94) is rotatably mounted inside the arc-shaped frame (93). The adjustable speaker (6) is mounted on the arc-shaped block (94). The center of the arc-shaped frame (93) is aligned with the side of the adjustable speaker (6). When the center positions coincide, the first micro motor (92) is started, which drives the adjustable speaker (6) to rotate horizontally by ±15° through the arc frame (93) and arc block (94). The upper end of the first micro motor (92) is bolted to a ring bracket, and the ring bracket has an annular groove. The second bracket (96) is rotatably installed in the annular groove. The second micro motor (97) is bolted to the second bracket (96). The output end of the second micro motor (97) is connected and fixed to the center position of the side of the adjustable speaker (6). The adjustable speaker (6) is driven to rotate vertically by ±10° through the second micro motor (97).

7. The intelligent headrest for passenger seats in large civil aircraft according to claim 1, characterized in that, The headrest body (10) adopts a wrap-around arc design (7), extending 3-5cm to the ear on both sides; Preferably, the headrest body (10) includes a composite filling layer (8) and is provided with a removable antibacterial fabric. The composite filling layer (8) is filled with high-density memory foam and porous sound-absorbing material. A pressure sensor is provided inside the headrest body (10) to sense the pressure of the composite filling layer (8) and is electrically connected to the signal processing module (4). Preferably, the pressure sensor is electrically connected to the signal processing module (4) to sense the pressure of the composite filling layer (8) and trigger the system to wake up automatically. The wake-up objects include the head motion tracking module, the noise acquisition module, the secondary sound source system and the control module.

8. The intelligent headrest for passenger seats in large civil aircraft according to claim 4, characterized in that, The civil aviation head posture feature library contains contour features, pressure distribution features, and posture motion features of typical head postures of civil aviation passengers, such as leaning forward, leaning to the left / right, head down, and head up. The ANC chip has a built-in lightweight deep learning MobileNet model, which is used to perform typical posture recognition on multi-sensor data after Kalman filtering algorithm fusion. Combined with ellipse fitting + radial range analysis method, it can predict and correct the ear canal center coordinates in real time with a positioning accuracy of ≤1mm. The civil aviation head posture feature library and MobileNet model are both embedded in the on-chip memory of the ANC chip. The model has been lightweighted and trimmed, reducing computing power consumption by 60% and eliminating the need for an external computing module.

9. A smart headrest for a passenger seat in a large civil aircraft according to claim 8, characterized in that, The dual-dimensional noise reduction parameter library, which considers both flight phase and ear position, is trained based on noise spectrum data, positioning data, and noise reduction effect data from different aircraft models, flight phases, ear positions, and seating areas. This data is stored in the flash memory of the ANC chip. 10% of the flash memory is reserved for storing real-time data during flight, and the model parameters can be periodically updated via onboard Wi-Fi. The ANC chip automatically switches the dimensional weights of the dual-dimensional noise reduction parameter library based on the real-time flight parameters of the aircraft's avionics system, achieving scenario-based intelligent matching of noise reduction parameters.

10. A noise reduction control method based on the intelligent headrest for passenger seats in large civil aircraft as described in any one of claims 1-9, characterized in that, Including the following steps: The pressure sensor senses the contact pressure between the passenger's head and the headrest body (10). When the pressure value is greater than or equal to the preset threshold, the head motion tracking module, noise acquisition module, signal processing module (4), secondary sound source system and control module are automatically activated. The ANC chip of the signal processing module (4) establishes communication with the aircraft avionics system to obtain real-time flight parameters such as aircraft model, flight stage, altitude, and thrust. Based on the flight parameters, the corresponding basic noise reduction parameter configuration scheme is preloaded from the dual-dimensional noise reduction parameter library of flight stage + human ear position. The infrared radar sensor (5), pressure sensor, and MEMS attitude sensor of the head motion tracking module synchronously collect head data and transmit it to the ANC chip for fusion and noise reduction through Kalman filtering algorithm; the ANC chip calls the civil aviation human head attitude feature library, performs typical attitude recognition through MobileNet model, and combines ellipse fitting + radial range analysis to realize the prediction and real-time correction of the ear hole center coordinates; the control module drives the micro dual-axis rotation mechanism (9) to drive the adjustable speaker (6) to adjust the angle so that the sound outlet is aligned with the ear hole according to the ear hole center coordinate data; An array-type feedforward microphone (1) collects multi-source noise from the cabin environment, a feedback microphone (2) collects residual noise around the ear, and an ear pressure sensor collects ear pressure values ​​around the ear in real time. Various analog signals are converted into 24-bit digital signals by an ADC analog-to-digital converter and then transmitted to the ANC chip. The blind source separation algorithm module realizes the real-time separation of low-frequency engine noise, airflow noise, and high-frequency noise from passenger conversation. The ANC chip employs a differentiated noise reduction strategy for the different noise sources after separation, generating a reverse cancellation sound wave digital signal; at the same time, it dynamically adjusts the noise reduction parameters based on the residual noise data of the feedback microphone (2), and calculates the correction coefficient through the PID algorithm module based on the value of the ear pressure sensor, dynamically adjusting the output amplitude of the adjustable speaker (6) to ensure that the ear pressure is maintained within the comfortable threshold range. The ANC chip converts the digital signal of the reverse cancellation sound wave into an analog signal and transmits it to the adjustable speaker (6). The reverse cancellation sound wave output by the speaker is superimposed with the cabin environment noise to achieve precise noise reduction. The head motion tracking module continuously collects head motion data and updates the ear canal center coordinates in real time. The control module adjusts the angle of the adjustable speaker (6) in conjunction with the control module. The ANC chip continuously receives the flight parameters of the aircraft avionics system and the signal from the noise acquisition module, switches the weight of the dual-dimensional noise reduction parameter library in real time, and dynamically adjusts the differentiated noise reduction strategy to achieve adaptive and precise noise reduction throughout the entire flight process.

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