Active noise reduction method and device of vehicle and vehicle
By installing multiple error microphones and adaptive filters above the vehicle seats, the noise cancellation signal is adjusted in real time to adapt to changes in seat position, thus solving the problem of noise changes caused by seat adjustment and improving the stability and effectiveness of the active noise cancellation system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG GEELY HLDG GRP CO LTD
- Filing Date
- 2026-01-26
- Publication Date
- 2026-05-01
AI Technical Summary
In vehicle hybrid mode, seat adjustment causes changes in noise levels near the occupant's ears. The noise reduction effect of existing active noise cancellation systems is greatly affected by changes in seat position and is difficult to maintain stability.
Multiple error microphones are installed above the vehicle seats. Through an adaptive filter and speaker system, the noise reduction signal is adjusted in real time to adapt to changes in seat position, generating an adaptive secondary sound source to cancel noise.
The noise reduction effect at the headrest position has been improved when adjusting the seat, thus enhancing the user experience.
Smart Images
Figure CN121963687A_ABST
Abstract
Description
Active noise reduction methods, devices and vehicles for vehicles Technical Field
[0001] This application relates to the field of active noise reduction technology for vehicles, and more particularly to an active noise reduction method, device, and vehicle for vehicles. Background Technology
[0002] PHEV (Plug-in Hybrid Electric Vehicle) models include both pure electric and hybrid modes. Compared to pure electric mode, the noise level in hybrid mode differs significantly due to the engine's operation, leading to a less pleasant user experience. Therefore, higher demands are placed on vehicle noise reduction.
[0003] Traditional noise reduction methods mainly include passive control measures such as structural optimization and sound absorption / insulation schemes. These methods not only have limited effectiveness but also increase weight and cost, resulting in low cost-effectiveness. In contrast, active noise cancellation methods primarily use speakers to emit anti-phase sound waves to cancel engine noise. This not only provides better noise reduction but also avoids increasing hardware weight and cost, and has begun to become one of the important development directions for automotive NVH control.
[0004] In active noise cancellation systems for vehicles, error microphones that collect noise signals are typically placed at the headrest or in the ceiling close to the occupant's ears (generally requiring a distance of ≤20cm). The former is more expensive and used in some high-end vehicles, while most vehicles use the latter. Active noise cancellation primarily reduces noise in the area where the error microphone is installed; therefore, the further away from the error microphone, the worse the noise reduction effect. Currently, car seats have a wide range of adjustment, with seat backrests adjustable from 40° to 135° or even greater. When the seat is adjusted, the noise level near the occupant's ears will undoubtedly change. Therefore, ensuring that the noise reduction effect near the occupant's ears (i.e., at the headrest) does not deteriorate with changes in seat position has become one of the urgent technical challenges to be solved in the industry. Summary of the Invention
[0005] This application provides an active noise reduction method, device, and vehicle for a vehicle, which can improve the noise reduction effect at the headrest position when the seat is adjusted.
[0006] This application provides an active noise cancellation method for a vehicle. The vehicle includes an active noise cancellation device, multiple error microphones, a speaker, and multiple seats. The multiple error microphones are respectively disposed above the corresponding seats, and the speaker is disposed in the vehicle's cabin. The active noise cancellation method is applied to the active noise cancellation device, which includes an adaptive filter. The active noise cancellation method includes: acquiring the vehicle's engine speed signal, the current signal of a first noise collected by the multiple error microphones, and the current headrest position information of the headrests of the multiple seats; determining the current signal of a second noise at the headrest position of the seat based on the current signal of the first noise from the error microphones and the current headrest position information of the seat corresponding to the error microphone; determining a primary noise reference signal generated by the vehicle's engine based on the engine speed signal; determining the weighting coefficients of the adaptive filter based on the primary noise reference signal and the current signal of the second noise at the headrest positions of the multiple seats; inputting the primary noise reference signal into the adaptive filter after determining the weighting coefficients to generate a secondary noise signal; and controlling the speaker to emit a secondary sound source based on the secondary noise signal.
[0007] In some embodiments, based on the current signal of the first noise from the error microphone and the current headrest position information of the seat corresponding to the error microphone, the current signal of the second noise at the headrest position of the seat can be determined. Based on the primary noise reference signal and the current signals of the second noise at the headrest positions of multiple seats, the weighting coefficients of the adaptive filter are determined, thereby generating a secondary noise signal. Thus, the secondary noise signal is generated based on the current signals of the second noise at the headrest positions of multiple seats. When the positions of the headrests of multiple seats change, the secondary noise signal changes accordingly, so that the secondary sound source emitted by the speaker can adapt to the change in the headrest position, better cancel the current signals of the second noise at the headrest position, improve the noise reduction effect at the headrest position, and improve the user experience.
[0008] Optionally, obtaining the current headrest position information of the headrests of the plurality of seats includes: obtaining the fore-aft adjustment travel, the up-down adjustment travel, and the seat back angle of each seat respectively; determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise from the error microphone and the current headrest position information of the seat corresponding to the error microphone includes: determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise from the error microphone, the fore-aft adjustment travel, the up-down adjustment travel, and the seat back angle of the seat corresponding to the error microphone.
[0009] In some embodiments, the current signal of the second noise at the position of the headrest of each seat can be easily and conveniently determined based on the fore-and-aft adjustment travel, the up-and-down adjustment travel, and the seat back angle of each seat.
[0010] Optionally, determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise from the error microphone, the fore-aft adjustment travel, the up-down adjustment travel of the seat corresponding to the error microphone, and the seat back angle includes: determining the current distance between the headrest position and the corresponding error microphone position based on the fore-aft adjustment travel, the up-down adjustment travel, the seat back angle, and the position of the corresponding error microphone; and determining the current signal of the second noise at the headrest position based on the current signal of the first noise collected by the corresponding error microphone and the current distance.
[0011] In some embodiments, the current signal of the second noise at the headrest position of the seat can be easily and conveniently determined based on the seat's fore-and-aft adjustment travel, up-and-down adjustment travel, seat back angle, the position of the corresponding error microphone, and the current distance between the headrest position of the seat and the position of the corresponding error microphone.
[0012] Optionally, determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise collected by the corresponding error microphone and the current distance includes: determining the current signal of the second noise by substituting the current signal of the first noise collected by the error microphone, the corresponding current distance, and the value obtained by substituting the corresponding current distance into a relational function; the relational function characterizes the relationship between the second noise signal and the first noise signal, and the distance between the headrest position and the corresponding error microphone position.
[0013] In some embodiments, the current signal of the second noise can be easily determined based on the relationship function between the second noise signal and the first noise signal, and between the position of the headrest and the position of the corresponding error microphone.
[0014] Optionally, the relationship function is determined by the following steps: acquiring the test signal of the first noise collected by the error microphone, the position test information of the headrest of the seat corresponding to the error microphone adjusted to multiple positions, and the test signal of the second noise at the multiple positions; and determining the relationship function based on the test signal of the first noise, the multiple position test information, and the test signal of the second noise at the multiple positions.
[0015] In some embodiments, the relationship function can be accurately determined based on the test signal of the first noise, test information at multiple locations, and test signals of the second noise at multiple locations.
[0016] Optionally, determining the weighting coefficients of the adaptive filter based on the primary noise reference signal and the current signals of the second noise at the positions of the headrests of the plurality of seats includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the plurality of seats, and the position information of the plurality of speakers distributed in the cabin.
[0017] In some embodiments, the weighting coefficients of the adaptive filter are determined based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the multiple seats, and the position information of the multiple speakers distributed in the cabin. This allows the weighting coefficients of the adaptive filter to adapt to the positions of the multiple speakers in the cabin, so that the secondary sound sources emitted by the speakers can better cancel the current signal of the second noise at the headrest positions, thereby improving the noise reduction effect.
[0018] Optionally, determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the plurality of seats, and the position information of the plurality of speakers distributed in the cabin includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the plurality of seats, the position information of the plurality of speakers, and the values of multiple transfer functions of the position information of the plurality of speakers and the current headrest position information of each seat.
[0019] In some embodiments, the weighting coefficients of the adaptive filter can be easily determined based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the multiple seats, the position information of the multiple speakers, and the values of multiple transfer functions of the position information of the multiple speakers and the current headrest position information of each seat.
[0020] This application provides a computer-readable storage medium having a program stored thereon that, when executed by a processor, implements the active noise reduction method for a vehicle as described in any of the preceding claims.
[0021] This application provides an active noise cancellation device for a vehicle, including one or more processors, for implementing the active noise cancellation method for a vehicle as described above.
[0022] This application provides a vehicle, including: a plurality of error microphones, a speaker, and a plurality of seats; the plurality of error microphones are respectively disposed above the respective seats, and the speaker is disposed in the cabin of the vehicle; and an active noise cancellation device as described above, the active noise cancellation device including an adaptive filter; the active noise cancellation device is communicatively connected to the plurality of error microphones, the speaker, and the plurality of seats.
[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description
[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0025] Figure 1 shows a partial structural block diagram of an embodiment of the vehicle of this application.
[0026] Figure 2 shows a flowchart of an embodiment of the active noise reduction method for vehicles according to this application.
[0027] Figure 3 is a schematic diagram of one embodiment of a partial structure of the vehicle of this application.
[0028] Figure 4 shows a structural block diagram of an embodiment of the active noise cancellation device for vehicles according to this application. Detailed Implementation
[0029] This application provides an active noise cancellation method, apparatus, and vehicle for a vehicle. The active noise cancellation method, apparatus, and vehicle of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.
[0030] This application provides a vehicle, including: multiple error microphones, speakers, multiple seats, and an active noise cancellation device. The multiple error microphones are respectively disposed above the corresponding seats, and the speakers are disposed within the vehicle's cabin.
[0031] Multiple error microphones are used to collect noise signals. Each error microphone corresponds to one of the seats, and each error microphone is positioned above the corresponding seat. The error microphones are located in the ceiling of the vehicle cabin. In some embodiments, the multiple error microphones are positioned directly above the corresponding seats in the ceiling. In some embodiments, the error microphones are reused with the vehicle's voice microphones, thereby reducing vehicle costs.
[0032] Multiple seats are adjustable. Each seat includes a seat adjustment motor. The motor allows for vertical and horizontal adjustment of the seat, as well as adjustment of the seat back angle. The position of the headrest changes accordingly when the seat is adjusted.
[0033] Loudspeakers are used to emit secondary sound sources to cancel out vehicle noise. A vehicle includes multiple loudspeakers distributed throughout the passenger compartment. The secondary sound sources emitted by these multiple loudspeakers are superimposed to cancel out vehicle noise.
[0034] An active noise cancellation device is used to execute the active noise cancellation method of this application. The active noise cancellation device includes an adaptive filter. The adaptive filter is used to generate a secondary noise signal that cancels out the primary noise reference signal of the vehicle. A loudspeaker is used to emit a secondary sound source based on the secondary noise signal. The secondary noise signal generated by the adaptive filter can be adjusted by changing the weighting coefficients of the adaptive filter. The active noise cancellation device is communicatively connected to multiple error microphones, a loudspeaker, and multiple seats.
[0035] Figure 1 shows a partial structural block diagram of an embodiment of the vehicle of this application.
[0036] In the embodiment shown in Figure 1, the vehicle includes a digital cockpit host (DHU) and an audio controller (AUD).
[0037] The active noise cancellation (AUD) is integrated into the vehicle's audio controller. The AUD comprises a signal processor (DSP) and an amplifier (AMP). The DSP is used for engine order noise cancellation (EOC). The DSP includes an adaptive filter. The DSP receives signals such as engine speed and Hall effect signals from the seat adjustment motor. The DSP receives these signals via a CAN bus. The AMP amplifies the output signal of the DSP. The AUD includes an A2B slave device for audio acquisition, playback, link relay, clock synchronization, remote configuration, and power supply reception. The A2B slave device connects to an A2B microphone for synchronous transmission of audio data, control signals, clock synchronization, and bus power supply.
[0038] The Digital Cockpit Headquarters (DHU) includes a System-on-a-Chip (SoC) for cockpit navigation, multimedia, HMI interaction, and domain fusion control. The DHU also includes an A2B Master that provides synchronization clocks and configuration commands to A2B slave devices. The A2B bus simplifies the topology and reduces wiring and hardware costs.
[0039] Figure 2 is a flowchart of an embodiment of the active noise cancellation method 10 for vehicles according to this application. The active noise cancellation method 10 for vehicles is applied to an active noise cancellation device. As shown in Figure 2, the active noise cancellation method 10 for vehicles includes steps 11 to 16.
[0040] Step 11: Obtain the vehicle's engine speed signal, the current signal of the first noise collected by multiple error microphones, and the current headrest position information of multiple seat headrests.
[0041] The vehicle's engine is the primary source of noise. The engine speed signal is used to determine the vehicle's primary noise reference signal. The current signal of the primary noise is used to represent the noise collected in real-time by the error microphone. Current headrest position information is used to represent the real-time position of the seat's headrest. When the seat is adjusted, the position of the headrest changes, and the corresponding current headrest position information changes. For multiple seats in the vehicle, the current headrest position information is collected for each seat separately.
[0042] Step 12: Determine the current signal of the second noise at the position of the headrest of the seat based on the current signal of the first noise from the error microphone and the current headrest position information of the seat corresponding to the error microphone.
[0043] The current signal of the second noise is used to represent the real-time noise at the headrest position of the seat. Based on the current headrest position information and the current signal of the first noise from the error microphone above the seat, the current signal of the second noise at the headrest position can be determined. The noise at the headrest position can be determined based on the noise at the error microphone and the headrest position. When the headrest position changes, the current headrest position information changes accordingly, and the current signal of the second noise changes accordingly, thus allowing the current signal of the second noise to reflect changes in the headrest position.
[0044] Step 13: Determine the primary noise reference signal generated by the vehicle's engine based on the engine speed signal.
[0045] Based on the engine speed signal, the engine order and frequency are calculated, and a time-domain sinusoidal signal with the same frequency amplitude but opposite phase is constructed. This time-domain sinusoidal signal is used as the primary noise reference signal.
[0046] Step 14: Determine the weighting coefficients of the adaptive filter based on the primary noise reference signal and the current signals of the second noise at the positions of the headrests of the multiple seats.
[0047] By adjusting the weighting coefficients of the adaptive filter, the generated inverted drive signal can be adjusted, thereby regulating the generated secondary noise signal. The weighting coefficients of the adaptive filter are determined based on the primary noise reference signal and the current signal of the second noise. Since the current signal of the second noise is determined based on the current position of the headrest, the weighting coefficients of the adaptive filter are determined according to the current position of the headrest and change as the headrest position changes.
[0048] Step 15: Input the primary noise reference signal into the adaptive filter after determining the weighting coefficients to generate the secondary noise signal.
[0049] The adaptive filter generates a secondary noise signal based on the primary noise reference signal and weighting coefficients. Since the weighting coefficients of the adaptive filter are determined based on the current position of the headrest, the secondary noise signal can adapt to the current position of the headrest.
[0050] Step 16: Control the speaker to emit a secondary sound source based on the secondary noise signal.
[0051] The secondary sound source emitted by the loudspeaker is used to cancel the current signal of the second noise at the headrest position. The secondary noise signal changes as the headrest position changes, but the secondary sound source generated based on the secondary noise signal can still cancel the current signal of the second noise at the headrest position when the headrest position changes.
[0052] In some embodiments, based on the current signal of the first noise from the error microphone and the current headrest position information of the seat corresponding to the error microphone, the current signal of the second noise at the headrest position of the seat can be determined. Based on the primary noise reference signal and the current signals of the second noise at the headrest positions of multiple seats, the weighting coefficients of the adaptive filter are determined, thereby generating a secondary noise signal. Thus, the secondary noise signal is generated based on the current signals of the second noise at the headrest positions of multiple seats. When the positions of the headrests of multiple seats change, the secondary noise signal changes accordingly, so that the secondary sound source emitted by the speaker can adapt to the change in the headrest position, better cancel the current signals of the second noise at the headrest position, improve the noise reduction effect at the headrest position, and improve the user experience.
[0053] Figure 3 is a schematic diagram of one embodiment of a partial structure of the vehicle of this application.
[0054] The vehicle includes a seat 21, an error microphone 22, and a headrest 23. When adjusting the seat 21, x represents the fore-and-aft adjustment range of the seat 21, z represents the up-and-down adjustment range of the seat 21, and γ represents the backrest adjustment angle of the seat 21.
[0055] Step 11, “obtaining the current headrest position information of the headrests 23 of multiple seats 21”, includes: obtaining the fore-aft adjustment travel x, the up-down adjustment travel z, and the seat back angle γ of each seat 21 respectively; Step 12 includes: determining the current signal of the second noise at the position of the headrest 23 of the seat 21 based on the current signal of the first noise of the error microphone 22, the fore-aft adjustment travel x, the up-down adjustment travel z, and the seat back angle γ of the seat 21 corresponding to the error microphone 22.
[0056] The headrest 23 is fixed to the seat 21. The position of the headrest 23 changes as the seat 21 is adjusted. As the position of the headrest 23 changes, the current signal of the second noise also changes. The position of the headrest 23 can be determined based on the adjustment of the seat 21.
[0057] The fore-and-aft adjustment range x represents the distance the seat 21 moves along the longitudinal direction of the vehicle, affecting the X-axis coordinate of the headrest 23; the up-and-down adjustment range z represents the distance the seat 21 moves along the vertical direction of the vehicle, affecting the Z-axis coordinate of the headrest 23; the seat back angle γ represents the angle between the backrest and the seat cushion of the seat 21. Changes in the seat back angle γ will cause the headrest 23 to move in an arc around the backrest rotation point, affecting the X-axis and Z-axis coordinates of the headrest 23.
[0058] Based on the current signal of the first noise and the position of the headrest 23, the current signal of the second noise at the headrest 23 can be determined.
[0059] In some embodiments, the current signal of the second noise at the position of the headrest 23 of each seat 21 can be easily determined based on the fore-and-aft adjustment travel x, the up-and-down adjustment travel z, and the seat back angle γ of each seat 21.
[0060] The step of determining the current signal of the second noise at the position of the headrest 23 of the seat 21 based on the current signal of the first noise from the error microphone 22, the fore-and-aft adjustment travel x of the seat 21 corresponding to the error microphone 22, the up-and-down adjustment travel z, and the seat back angle γ includes: determining the current distance between the position of the headrest 23 of the seat 21 and the position of the corresponding error microphone 22 based on the fore-and-aft adjustment travel x, the up-and-down adjustment travel z, the seat back angle γ, and the position of the corresponding error microphone 22; and determining the current signal of the second noise at the position of the headrest 23 of the seat 21 based on the current signal of the first noise collected by the corresponding error microphone 22 and the current distance.
[0061] Based on the fore-and-aft adjustment range x and the up-and-down adjustment range z of the seat 21, and the seat back angle γ, the position coordinates of the headrest 23 relative to the error microphone 22 can be determined. Based on the positions of the error microphone 22 and the headrest 23, the current distance between them can be determined. Due to this current distance, the current signal of the second noise differs from the current signal of the first noise. Based on the current signal of the first noise and the current distance, the current signal of the second noise at the position of the headrest 23 can be determined.
[0062] In some embodiments, the position of the error microphone 22 is used as a reference coordinate point, and the distance function between the headrest 23 and the error microphone 22 is determined as D(x,z,γ). Using the distance function D(x,z,γ), the current distance between the headrest 23 and the error microphone 22 can be accurately determined. Based on the current signal of the first noise and the current distance between the headrest 23 and the error microphone 22, the current signal of the second noise at the headrest 23 position of the seat 21 is determined, such that the current signal of the second noise can be changed according to the current signal of the first noise and the current distance, so that the current signal of the second noise can reflect the changes caused by the change in the positional relationship between the headrest 23 and the error microphone 22.
[0063] In some embodiments, based on the fore-and-aft adjustment travel x, the up-and-down adjustment travel z, and the seat back angle γ of the seat 21, the position of the corresponding error microphone 22, and the current distance between the position of the headrest 23 of the seat 21 and the position of the corresponding error microphone 22, the current signal of the second noise at the position of the headrest 23 of the seat 21 can be easily and conveniently determined.
[0064] The step of determining the current signal of the second noise at the position of the headrest 23 of the seat 21 based on the current signal and current distance of the first noise collected by the corresponding error microphone 22 includes: determining the current signal of the second noise by substituting the current signal of the first noise collected by the error microphone 22, the corresponding current distance, and the value obtained by substituting the corresponding current distance into the relational function; the relational function characterizes the relationship between the second noise signal and the first noise signal, and the distance between the position of the headrest 23 and the position of the corresponding error microphone 22.
[0065] The relationship function is a function with the fore-and-aft adjustment range x, the up-and-down adjustment range z, and the seat back angle γ of seat 21 as variables.
[0066] The current signal of the second noise at the position of the headrest 23 of seat 21 can be determined by formula (1).
[0067] Formula (1) where, The current signal of the second noise. For relational functions, The current signal of the first noise. This is the distance function.
[0068] For multiple seats, the current signal of the second noise at the headrest position of each seat can be determined by formulas (2) to (4).
[0069] Formula (2) Formula (3) Formula (4) where, , , These are the current signals of the second noise at the three seat headrest positions. , , These are the functions relating the second noise signal to the first noise signal at each headrest position, and the distance between the headrest position and the corresponding error microphone position. , , These are the current signals of the first noise from the error microphones corresponding to each seat headrest. , , These are the distance functions between each seat headrest and its corresponding error microphone.
[0070] Furthermore, we can obtain formula (5).
[0071] Formula (5) where, This is the current signal of the second noise at the k-th seat headrest position.
[0072] In some embodiments, the current signal of the second noise can be easily determined based on the relationship function between the second noise signal and the first noise signal, and between the position of the headrest 23 and the position of the corresponding error microphone 22.
[0073] In some embodiments, the relational function is determined by the following steps: acquiring a test signal of the first noise collected by the error microphone 22, position test information of the headrest 23 of the seat 21 corresponding to the error microphone 22 adjusted to multiple positions, and test signals of the second noise at multiple positions; and determining the relational function based on the test signal of the first noise, the multiple position test information, and the test signals of the second noise at multiple positions.
[0074] When determining the relationship function, for the same first noise test signal, the headrest 23 of the seat 21 is adjusted to multiple positions, and the second noise test signal of the headrest 23 at each position is collected respectively. Based on the first noise test signal, the collected multiple positions of the headrest 23, and the second noise test signals at each position, the relationship function is obtained by multiple linear fitting, or by fitting the relationship function by a neural network algorithm.
[0075] For different car models, test signals of the second noise at multiple positions of the headrest and at each position can be collected to obtain the corresponding relationship function for each car model.
[0076] In some embodiments, the relationship function can be accurately determined based on the test signal of the first noise, test information at multiple locations, and test signals of the second noise at multiple locations.
[0077] Step 14 includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the multiple seats, and the position information of the multiple speakers distributed in the cabin.
[0078] For the same primary noise reference signal and the current signal of the second noise, the secondary sound sources emitted by the speakers have different cancellation effects on the primary noise reference signal depending on their positions. Based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of multiple seats, and the position information of multiple speakers distributed throughout the cabin, the weighting coefficients of the adaptive filter are determined. This adjusts the secondary noise signal generated by the adaptive filter and the secondary sound sources emitted by the speakers, allowing the secondary noise signal to adjust according to the speaker positions, so that the secondary sound sources can better cancel the primary noise reference signal.
[0079] In some embodiments, the weighting coefficients of the adaptive filter are determined based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the multiple seats, and the position information of the multiple speakers distributed in the cabin. This allows the weighting coefficients of the adaptive filter to adapt to the positions of the multiple speakers in the cabin, so that the secondary sound sources emitted by the speakers can better cancel the current signal of the second noise at the headrest positions, thereby improving the noise reduction effect.
[0080] The step of determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the multiple seats, and the position information of the multiple speakers distributed in the cabin includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the multiple seats, the position information of the multiple speakers, and the values of multiple transfer functions of the position information of the multiple speakers and the current headrest position information of each seat.
[0081] For the same headrest position, the noise cancellation effect of secondary sound sources transmitted from speakers located at different positions within the vehicle cabin varies. Therefore, it is necessary to determine the positional relationship between each speaker and each headrest position. The transfer function characterizes the noise cancellation effect of the secondary sound sources emitted by each speaker on the noise at each headrest position. The transfer function of each speaker and headrest position can be expressed as follows: , which is the noise transfer function from the m-th speaker to the headrest position of the k-th seat.
[0082] The noise reduction effect of each speaker on the current signal of the second noise at each headrest position is different. Therefore, when determining the weight coefficients of the adaptive filter, it is necessary to consider the transfer function from each speaker to each headrest position, as well as the current signal of the second noise at each headrest position, so that a good noise reduction effect can be obtained at each headrest position.
[0083] The weighting coefficients of the adaptive filter can be determined by formula (6).
[0084] Formula (6) where, Adjust parameters, Let be the noise transfer function from the m-th speaker to the headrest position of the k-th seat. This is the primary noise reference signal.
[0085] The adaptive filter generates a secondary noise signal based on the weighting coefficients. The speaker generates a secondary sound source based on this secondary noise signal and transmits it to various areas of the vehicle to cancel out the noise in each area, thus achieving noise reduction.
[0086] In some embodiments, the weighting coefficients of the adaptive filter can be easily determined based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the multiple seats, the position information of the multiple speakers, and the values of multiple transfer functions of the position information of the multiple speakers and the current headrest position information of each seat.
[0087] Figure 4 shows a structural block diagram of an embodiment of the active noise cancellation device for vehicles according to this application.
[0088] As shown in Figure 4, the vehicle's active noise cancellation device includes one or more processors 31 for implementing the vehicle's active noise cancellation method 10 as described above.
[0089] In some embodiments, the vehicle's active noise cancellation device may include a computer-readable storage medium 32, which may store a program that can be invoked by a processor 31, and may include a non-volatile storage medium. In some embodiments, the vehicle's active noise cancellation device may include memory 33 and an interface 34. In some embodiments, the vehicle's active noise cancellation device may also include other hardware depending on the specific application.
[0090] The computer-readable storage medium 32 of this application embodiment stores a program that, when executed by the processor 31, is used to implement the active noise reduction method 10 for a vehicle as described above.
[0091] This application may take the form of a computer program product implemented on one or more computer-readable storage media 32 (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing program code. The computer-readable storage media 32 includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented using any method or technology. The information may be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media 32 include, but are not limited to: phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.
Claims
1. An active noise reduction method for vehicles, characterized in that, The vehicle includes an active noise cancellation device, multiple error microphones, a speaker, and multiple seats; the multiple error microphones are respectively disposed above the corresponding seats, and the speaker is disposed in the cabin of the vehicle; The active noise reduction method for the vehicle is applied to the active noise reduction device, which includes an adaptive filter. The active noise reduction method for the vehicle includes: acquiring the vehicle's engine speed signal, the current signal of a first noise collected by the plurality of error microphones, and the current headrest position information of the plurality of seat headrests; determining the current signal of a second noise at the headrest position of the seat based on the current signal of the first noise from the error microphone and the current headrest position information of the seat corresponding to the error microphone; determining a primary noise reference signal generated by the vehicle's engine based on the engine speed signal; determining the weighting coefficients of the adaptive filter based on the primary noise reference signal and the current signal of the second noise at the headrest positions of the plurality of seats; inputting the primary noise reference signal into the adaptive filter after determining the weighting coefficients to generate a secondary noise signal; and controlling the speaker to emit a secondary sound source based on the secondary noise signal.
2. The active noise reduction method for vehicles according to claim 1, characterized in that, The step of obtaining the current headrest position information of the headrests of the plurality of seats includes: obtaining the fore-aft adjustment travel, the up-down adjustment travel, and the seat back angle of each seat respectively; the step of determining the current signal of the second noise at the position of the headrest of the seat based on the current signal of the first noise of the error microphone and the current headrest position information of the seat corresponding to the error microphone includes: determining the current signal of the second noise at the position of the headrest of the seat based on the current signal of the first noise of the error microphone, the fore-aft adjustment travel, the up-down adjustment travel, and the seat back angle of the seat corresponding to the error microphone.
3. The active noise reduction method for vehicles according to claim 2, characterized in that, The step of determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise from the error microphone, the fore-aft adjustment travel, the up-down adjustment travel of the seat corresponding to the error microphone, and the seat back angle includes: determining the current distance between the headrest position and the corresponding error microphone position based on the fore-aft adjustment travel, the up-down adjustment travel, the seat back angle, and the position of the corresponding error microphone; and determining the current signal of the second noise at the headrest position based on the current signal of the first noise collected by the corresponding error microphone and the current distance.
4. The active noise reduction method for vehicles according to claim 3, characterized in that, The step of determining the current signal of the second noise at the headrest position of the seat based on the current signal of the first noise collected by the corresponding error microphone and the current distance includes: determining the current signal of the second noise by substituting the current signal of the first noise collected by the error microphone, the corresponding current distance, and the value obtained by substituting the corresponding current distance into a relational function; the relational function characterizes the relationship between the second noise signal and the first noise signal, and the distance between the headrest position and the corresponding error microphone position.
5. The active noise reduction method for vehicles according to claim 4, characterized in that, The relationship function is determined by the following steps: acquiring the test signal of the first noise collected by the error microphone, the position test information of the headrest of the seat corresponding to the error microphone adjusted to multiple positions, and the test signal of the second noise at the multiple positions; The relationship function is determined based on the test signal of the first noise, the test information of the plurality of locations, and the test signal of the second noise at the plurality of locations.
6. The active noise reduction method for vehicles according to claim 1, characterized in that, The step of determining the weighting coefficients of the adaptive filter based on the primary noise reference signal and the current signals of the second noise at the positions of the headrests of the plurality of seats includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signals of the second noise at the positions of the headrests of the plurality of seats, and the position information of the plurality of speakers distributed in the cabin.
7. The active noise reduction method for vehicles according to claim 6, characterized in that, The step of determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the plurality of seats, and the position information of the plurality of speakers distributed in the cabin includes: determining the weighting coefficients of the adaptive filter based on the primary noise reference signal, the current signal of the second noise at the headrest positions of the plurality of seats, the position information of the plurality of speakers, and the values of multiple transfer functions of the position information of the plurality of speakers and the current headrest position information of each seat.
8. A computer-readable storage medium, characterized in that, It stores a program that, when executed by a processor, implements the active noise reduction method for a vehicle as described in any one of claims 1 to 7.
9. An active noise reduction device for a vehicle, characterized in that, It includes one or more processors for implementing the active noise reduction method for the vehicle according to any one of claims 1-7.
10. A vehicle, characterized in that, include: Multiple error microphones, speakers, and multiple seats; the multiple error microphones are respectively disposed above the corresponding seats, and the speakers are disposed in the cabin of the vehicle; And the active noise cancellation device as described in claim 9, wherein the active noise cancellation device includes an adaptive filter; the active noise cancellation device is communicatively connected to the plurality of error microphones, the speaker and the plurality of seats.