Noise reduction control method, noise reduction equipment, noise reduction headrest, noise reduction seat and vehicle

Abstract

The invention discloses a noise reduction control method, noise reduction equipment, a noise reduction headrest, a noise reduction seat and a vehicle. The noise detection device is used for detecting noise around human ears; the position detection device is used for detecting the current human ear position; the displacement control device is electrically connected with the position detection device and the sound production device, and the displacement control device is used for controlling the sound production device to move in the direction close to the human ear according to the current human ear position; the noise reduction controller is electrically connected with the sound production device, the noise detection device and the position detection device, and the noise reduction controller is used for determining a target noise reduction coefficient matched with the current human ear position from multiple pre-stored noise reduction coefficients and controlling the sound production device to produce a secondary sound field according to the target noise reduction coefficient and the noise around the human ear; noise around human ears is at least partially offset. According to the invention, the technical problem of poor noise reduction effect of active noise reduction control is solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of noise reduction technology, and particularly relates to a noise reduction control method, a noise reduction device, a noise reduction headrest, a noise reduction seat and a vehicle. BACKGROUND

[0002] Traditional passive noise control technology (such as sound absorption, sound insulation, etc.) is limited by factors such as weight and volume, and has insufficient control ability for low-frequency sound. ANC (Active Noise Control, Active Noise Control) technology has flexible configuration and can better achieve low-frequency sound control. ANC refers to the purposeful artificial generation of a secondary sound field to control the original noise, among which, the one for the purpose of reducing noise is also commonly known as active noise reduction, active noise attenuation or anti-sound technology; and in active noise reduction, the energy of the original noise is absorbed by the secondary sound field and converted into heat energy, which is also known as active sound absorption or active sound absorption. In related technologies, the active noise reduction control of the active noise reduction region is limited, and the noise reduction effect is poor. SUMMARY

[0003] The present application provides a noise reduction control method, a noise reduction device, a noise reduction headrest, a noise reduction seat and a vehicle, to solve the technical problem of poor noise reduction effect of active noise reduction control in related technologies.

[0004] In a first aspect of the present application, an active noise reduction device is provided, comprising: a sound generating device; a noise detection device for detecting the noise around the human ear; a position detection device for detecting the current position of the human ear; a displacement control device electrically connected with the position detection device and the sound generating device, the displacement control device being configured to control the sound generating device to move towards the human ear according to the current position of the human ear; and a noise reduction controller electrically connected with the sound generating device, the noise detection device and the position detection device, the noise reduction controller being configured to determine a target noise reduction coefficient matching the current position of the human ear from a plurality of pre-stored noise reduction coefficients, and to control the sound generating device to generate a secondary sound field according to the target noise reduction coefficient and the noise around the human ear, so as to at least partially cancel out the noise around the human ear.

[0005] In combination with the first aspect, in some embodiments, the displacement control device comprises: a displacement controller electrically connected with the position detection device; and a displacement execution mechanism electrically connected with the displacement controller, the sound generating device being arranged on the displacement execution mechanism, or the sound generating device being connected with the displacement execution mechanism through a transmission mechanism; wherein the displacement controller is configured to obtain the current position of the human ear from the position detection device, and to control the displacement execution mechanism to move according to the current position of the human ear, so as to drive the sound generating device to move towards the human ear.

[0006] In some embodiments of the first aspect, the displacement controller is configured to: obtain a current sound source position of the sound generating device; determine relative position information between the current human ear position and the current sound source position; and control a direction and distance of movement of the displacement execution mechanism according to the relative position information.

[0007] In some embodiments of the first aspect, the noise reduction controller is configured to: determine a target height interval in which a current human ear height is located from a plurality of pre-divided height intervals, the plurality of pre-stored noise reduction coefficients corresponding to the plurality of pre-divided height intervals one by one, the current human ear position including the current human ear height; and determine a target noise reduction coefficient pre-stored for the target height interval from the plurality of pre-stored noise reduction coefficients.

[0008] In some embodiments of the first aspect, the position detection device includes: an infrared sensor array including at least one column of infrared sensors, wherein each column of infrared sensors is arranged in a path parallel to a movement path of the sound generating device; and a position calculation unit configured to determine the current human ear position according to sensing data of the infrared sensor array.

[0009] In a second aspect of the present application, a noise reduction headrest is provided, including: a headrest body and the active noise reduction device of any one of the embodiments of the first aspect, the active noise reduction device being arranged in the headrest body, wherein the sound generating device is movably arranged in the headrest body relative to the headrest body; and the displacement control device is configured to control movement of the sound generating device relative to the headrest body according to the current human ear position obtained from the position detection device, so as to drive the sound generating device to move towards the human ear.

[0010] In a third aspect of the present application, a noise reduction seat is provided, including: a seat body and the active noise reduction device of any one of the embodiments of the second aspect, the active noise reduction device being arranged in the seat body, wherein the seat body has a load bearing part, a backrest part and a headrest part, at least the sound generating device and the position detection device of the active noise reduction device being arranged in the headrest part, and the sound generating device being movable relative to the headrest part; and the displacement control device is configured to control movement of the sound generating device relative to the headrest part according to the current human ear position obtained from the position detection device, so as to drive the sound generating device to move towards the human ear.

[0011] In a fourth aspect of the present application, a vehicle is also provided, comprising: a passenger cabin; a seat body arranged in the passenger cabin, wherein the seat body comprises a bearing part, a backrest part and a headrest part, the headrest part being movably connected relative to the backrest part; the active noise reduction device according to any one of the first aspect or the embodiments thereof, at least the sound emitting device of the active noise reduction device being arranged in the headrest part; and the displacement control device is configured to control the headrest part to move relative to the backrest part according to the current ear position, so as to drive the sound emitting device to move towards the ear.

[0012] In combination with the fourth aspect, in some embodiments, the position detection device of the active noise reduction device comprises: at least one infrared sensor arranged on a roof of the passenger cabin and opposite to the bearing part of the seat body; and a position calculation unit configured to determine the current ear position according to sensing data of the at least one infrared sensor.

[0013] In a fifth aspect of the present application, an active noise reduction control method is also provided, applied to an active noise reduction device having a sound emitting device, the method comprising: obtaining an ambient noise around an ear and a current ear position; controlling the sound emitting device to move towards the ear according to the current ear position; determining a target noise reduction coefficient matched with the current ear position from a plurality of pre-stored noise reduction coefficients; and controlling the sound emitting device to generate a secondary sound field according to the target noise reduction coefficient and the ambient noise around the ear, so as to at least partially offset the ambient noise around the ear.

[0014] In combination with the fifth aspect, in some embodiments, the controlling the sound emitting device to move towards the ear according to the current ear position comprises: obtaining a current sound source position of the sound emitting device; determining relative position information between the current ear position and the current sound source position; and controlling a moving direction and distance of the sound emitting device according to the relative position information, so as to make the sound emitting device move towards the ear.

[0015] In combination with the fifth aspect, in some embodiments, the relative position information comprises a relative distance and a relative direction, and the controlling the moving direction and distance of the sound emitting device according to the relative position information comprises: if the relative distance between the current ear position and the current sound source position is greater than a preset distance threshold, performing the controlling the moving direction and distance of the sound emitting device according to the relative position information.

[0016] In some embodiments of the fifth aspect, the current human ear position comprises a current human ear height, and the target noise reduction coefficient matched with the current human ear position is determined from the plurality of pre-stored noise reduction coefficients by: determining a target height interval in which the current human ear height is located from a plurality of pre-divided height intervals, the plurality of pre-stored noise reduction coefficients corresponding to the plurality of pre-divided height intervals one by one; and determining a target noise reduction coefficient pre-stored for the target height interval from the plurality of pre-stored noise reduction coefficients.

[0017] In some embodiments of the fifth aspect, the plurality of pre-stored noise reduction coefficients are obtained by the following steps in advance:

[0018] For each height interval in the plurality of pre-divided height intervals, an error signal is obtained by an error microphone arranged at a binaural position of the human head model in a state in which the human head model is in the height interval, the error signal being formed by superimposition of a noise signal at the binaural position of the human head model and a secondary sound field generated by the sound generating device.

[0019] The filter coefficient is adjusted according to the error signal, and when the adjusted filter coefficient satisfies a preset convergence condition, the adjusted filter coefficient is taken as the noise reduction coefficient corresponding to the height interval.

[0020] The one or more technical solutions provided by the embodiments of the present application at least achieve the following technical effects or advantages:

[0021] The active noise reduction device provided by the embodiments of the present application comprises a sound generating device, a noise detection device for detecting noise around a human ear, a position detection device for detecting a current human ear position, a displacement control device electrically connected with the position detection device and the sound generating device, the displacement control device being configured to control the sound generating device to move towards the human ear according to the current human ear position, and a noise reduction controller electrically connected with the sound generating device, the noise detection device and the position detection device, the noise reduction controller being configured to determine a target noise reduction coefficient matched with the current human ear position from a plurality of pre-stored noise reduction coefficients, and to control the sound generating device to generate a secondary sound field according to the target noise reduction coefficient and the noise around the human ear, so as to at least partially offset the noise around the human ear. It can be seen that the above technical solution positions the human ear, controls the sound generating device to move closer to the human ear according to the human ear position, so that the sound generating device tracks the human ear position, and the human ear is always in an area with the best noise reduction, thereby accurately reducing noise around the human ear. Furthermore, the noise reduction coefficient is matched with the human ear position to generate a secondary sound field, so that the phase difference between the generated secondary sound field and the noise around the human ear is closer to being opposite, thereby effectively improving the noise reduction amount. Therefore, the active noise reduction device provided by the embodiments of the present application can improve the noise reduction effect. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0023] Figure 1 A schematic diagram of an active noise reduction device provided by some embodiments of the present application is shown;

[0024] Figure 2A A schematic diagram of an active noise reduction device provided by some embodiments of the present application is shown; Figure 1 A longitudinal sectional schematic diagram of a noise reduction headrest of the active noise reduction device in the foregoing embodiment is shown;

[0025] Figure 2B A longitudinal sectional schematic diagram of a noise reduction headrest of the active noise reduction device in the foregoing embodiment is shown; Figure 1 A longitudinal sectional schematic diagram of a noise reduction headrest of the active noise reduction device in the foregoing embodiment is shown;

[0026] Figure 3 A longitudinal sectional schematic diagram of a noise reduction headrest of the active noise reduction device in the foregoing embodiment is shown; Figure 1 A schematic diagram of a noise reduction seat of the active noise reduction device in the foregoing embodiment is shown;

[0027] Figure 4 A schematic diagram of a noise reduction seat of the active noise reduction device in the foregoing embodiment is shown; Figure 1 A schematic diagram of a noise reduction seat of the active noise reduction device in the foregoing embodiment is shown;

[0028] Figure 5 A schematic diagram of an active noise reduction control method provided by some embodiments of the present application is shown;

[0029] Figure 6A A left ear spectrum diagram after noise reduction when a human ear is at h4 with and without height grading;

[0030] Figure 6B A left ear spectrum diagram after noise reduction when a human ear is at h4 with and without height grading;

[0031] Figure 6C A left ear spectrum diagram after noise reduction when a human ear is at h4 with and without height grading; DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0033] In addition, in the present invention, descriptions such as "first" and "second" are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] The present invention provides an active noise reduction device for reducing the noise around the human ear without the user having to wear the device. Figure 1 As shown, the active noise reduction device 100 provided by the present invention includes: a sound-generating device 110, a noise detection device 120, a position detection device 130, a displacement control device 140, and a noise reduction controller 150. The noise detection device 120 is used to detect noise around the human ear; the position detection device 130 is used to detect the current position of the human ear; the position detection device 130 and the sound-generating device 110 are both electrically connected to the displacement control device 140, and the displacement control device 140 is used to control the sound-generating device 110 to move closer to the human ear based on the current position of the human ear; the sound-generating device 110, the noise detection device 120, and the position detection device 130 are all electrically connected to the noise reduction controller 150, which is used to determine a target noise reduction coefficient that matches the current position of the human ear from multiple pre-stored noise reduction coefficients, and control the sound-generating device 110 to generate a secondary sound field based on the target noise reduction coefficient and the noise around the human ear, so as to at least partially offset the noise around the human ear.

[0035] It is understood that the noise reduction controller 150 uses the target noise reduction coefficient to process the detected ambient noise of the human ear to generate a control signal for the sound-generating device 110 and output it to the sound-generating device 110, so that the secondary sound field generated by the sound-generating device 110 under the control signal has a phase difference with the ambient noise of the human ear. Therefore, the secondary sound field generated by the sound-generating device 110 can at least partially offset the ambient noise of the human ear. In some embodiments, the secondary sound field generated by the sound-generating device 110 and the ambient noise of the human ear are in opposite phase (that is, there is a 180° phase difference), so that the secondary sound field generated by the sound-generating device 110 can completely offset the ambient noise of the human ear.

[0036] In some embodiments, the current human ear position only needs the current human ear height, and the position detection device 130 can only include a single infrared sensor 131a, which directly provides the current human ear height, wherein the single infrared sensor 131a can be an infrared ranging sensor or an infrared laser radar arranged in the top area of the user's head to detect the distance from the top of the head to the infrared ranging sensor, and the current human ear height can be obtained according to the distance. For example, the distance is taken as the current human ear height, or the distance is corrected to obtain the current human ear height.

[0037] In other embodiments, the position detection device 130 includes a position calculation unit (not shown) and an infrared sensor array 131 composed of a plurality of infrared sensors 131a, the infrared sensor array 131 includes at least one column of infrared sensors 131a, and the layout path of each column of infrared sensors 131a is parallel to the moving path of the sound emitting device 110. The position calculation unit is used to determine the current human ear position according to the sensing data of each infrared sensor 131a in the infrared sensor array 131, wherein the determined current human ear position only includes the current human ear height or simultaneously includes the current human ear height and horizontal position information. The current human ear height is a parameter relative to the vertical direction of the ground, and the horizontal position information is a parameter relative to the horizontal direction of the ground.

[0038] It can be understood that the position calculation unit reads the sensing data of each infrared sensor 131a in the infrared sensor array 131, and for each infrared sensor 131a in the infrared sensor array 131, the position calculation unit determines the blocking state of the infrared sensor 131a according to the sensing data of the infrared sensor 131a, which represents whether the infrared sensor 131a is blocked by the human head; the position calculation unit determines the current human ear position according to the blocking state of each infrared sensor 131a in the infrared sensor array 131.

[0039] In some embodiments, each infrared sensor 131a in the infrared sensor array 131 can adopt an infrared proximity sensor, an infrared ranging sensor, or an infrared laser radar.

[0040] In some embodiments, if the active noise reduction device 100 only needs to adapt to users of different heights, the moving path of the sound emitting device 110 can only include a path of moving up and down relative to the human ear position, so that the sound emitting device 110 can move up and down relative to the human ear, and then the current human ear position only needs the current human ear height, the infrared sensor array 131 is a column of infrared sensors 131a, the arrangement path of the column of infrared sensors 131a is parallel to the path of the sound emitting device 110 moving up and down relative to the human ear, that is, the plurality of infrared sensors 131a are arranged along a straight line perpendicular to the ground, and the position calculation unit determines which infrared sensors 131a are blocked by the human head by reading the sensing data output by the column of infrared sensors 131a, and then obtains the current human ear height. It should be noted that the parallel and perpendicular here refer to an included angle less than a predetermined angle threshold.

[0041] As shown in the examples, Figure 2A or Figure 3 As shown, three infrared sensors 131a on the same straight line can be arranged in parallel with the path of the sound emitting device 110 moving up and down relative to the human ear, and the interval between adjacent infrared sensors 131a can be, but is not limited to, 10 cm. If an infrared proximity sensor is used, its parameters can be, but are not limited to, as shown in Table 1:

[0042] Table 1. Parameters of infrared proximity sensor

[0043] Parameter Description Detection range 0~15cm in front Output form High-low digital output Anti-interference ability Not interfered by sunlight Trigger mode Schmitt trigger

[0044] In the embodiments of the present application, the model, number, size, spacing and other parameters of the infrared sensor 131a are only used to explain the present application and do not limit the present application.

[0045] In some embodiments, the active noise reduction device 100 needs to adapt to users of different heights and different sitting positions of the user, and the movement path of the sound generating device 110 includes at least one of the paths of moving forward and backward relative to the position of the human ear and moving left and right relative to the position of the human ear in addition to the path of moving up and down relative to the position of the human ear. In this case, the current position of the human ear needs the current height and horizontal position information of the human ear, and the infrared sensor array 131 includes multiple rows and multiple columns. The position calculation unit determines which sensors are blocked by the human head by reading the outputs of the multiple rows and multiple columns of infrared sensors 131a, and then obtains the current height and horizontal position information of the human ear. For example, the infrared sensor array 131 can be 3 rows * 3 columns, i.e., a total of 9 infrared sensors 131a, which are arranged along the path of moving up and down and moving left and right of the sound generating device 110 relative to the position of the human ear. Alternatively, the infrared sensor array 131 can include two columns of infrared sensors 131a, one of which is arranged along the path of moving up and down of the sound generating device 110 relative to the position of the human ear, and the other of which is arranged along the path of moving left and right of the sound generating device 110 relative to the position of the human ear. The two columns of infrared sensors 131a are arranged in a cross manner, and the distance between adjacent infrared sensors 131a in the same column can be, but is not limited to, 10 cm, such as 7 cm, 8 cm, 9 cm, 10 cm, or 11 cm.

[0046] According to one or more embodiments of the present application, since the position detection device 130 uses infrared sensors 131a to detect the current position of the human ear, it does not need to collect images of the user or wear devices for detecting the position of the human ear on the user, thereby achieving contactless detection of the position of the human ear without invading the privacy of the user.

[0047] In some embodiments, the displacement control device 140 includes a displacement controller 141 and a displacement execution mechanism 142. The displacement controller 141 is electrically connected to the position detection device 130. The displacement execution mechanism 142 is electrically connected to the displacement controller 141. The sound generating device 110 is arranged on the displacement execution mechanism 142, or the sound generating device 110 is connected to the displacement execution mechanism 142 through a transmission mechanism (not shown). The displacement controller 141 is configured to obtain the current position of the human ear from the position detection device 130 and control the displacement execution mechanism 142 to move according to the current position of the human ear, so that the displacement execution mechanism 142 drives the sound generating device 110 to move towards the position of the human ear.

[0048] It can be understood that the displacement execution mechanism 142 comprises at least one stage of sliding table module. For the moving path of the sound production device 110, only the path of up and down movement relative to the ear position, in some embodiments, the displacement execution mechanism 142 only comprises one stage of sliding table module, wherein the stage of sliding table module comprises a guide rail 142a, a motor (not shown) and a sliding block 142b driven by the motor to slide along the guide rail 142a, the sound production device 110 is directly fixed on the sliding block 142b or connected to the sliding block 142b of the uppermost stage of sliding table module through a transmission mechanism, the guide rail 142a is perpendicular or substantially perpendicular to the ground, so that the displacement execution mechanism 142 can directly drive the sound production device 110 to move up and down relative to the ear position to be closer to the ear, or the sliding of the sliding block 142b drives the sound production device 110 to move through the transmission mechanism, so that the sound production device 110 moves up and down relative to the ear position to be closer to the ear. For the moving path of the sound production device 110, in addition to the path of up and down movement relative to the ear position, at least one of the paths of forward and backward movement and left and right movement relative to the ear position, in some embodiments, the displacement execution mechanism 142 comprises a plurality of stages of sliding table module, each stage of sliding table module comprises a guide rail 142a, a motor and a sliding block 142b driven by the motor to slide along the guide rail 142a, the sound production device 110 is directly fixed on the sliding block 142b of the uppermost stage of sliding table module or connected to the sliding block 142b of the uppermost stage of sliding table module through a transmission mechanism, so that the displacement execution mechanism 142 can directly drive the sound production device 110 to move relative to multiple directions of the ear position to be closer to the ear, or the sliding of the sliding block 142b drives the sound production device 110 to move through the transmission mechanism, so that the sound production device 110 moves relative to multiple directions of the ear position to be closer to the ear.

[0049] In some embodiments, the transmission mechanism can adopt a connecting rod mechanism, the operation of the sliding block 142b drives the connecting rod mechanism to move, and the movement of the connecting rod mechanism drives the sound production device 110 to move.

[0050] In some embodiments, the displacement controller 141 is configured to: acquire a current sound source position of the sound production device 110; determine relative position information between the current ear position and the current sound source position; and control a direction and a distance of movement of the displacement execution mechanism 142 according to the relative position information. It can be understood that the displacement controller 141 is electrically connected with the motor of each stage of sliding table module, and the displacement controller 141 controls the operation of the motor of each stage of sliding table module according to the relative position information between the current ear position and the current sound source position, so as to control the direction and the distance of movement of the displacement execution mechanism 142.

[0051] In some embodiments, the displacement controller 141 and the noise reduction controller 150 can be implemented by two microcontroller units (MCU) respectively, or by the same microcontroller unit.

[0052] In some embodiments, the relative position information includes a relative distance and a relative direction, and the displacement controller 141 is configured to: determine whether the relative distance between the current ear position and the current sound source position is greater than a preset distance threshold; if the relative distance between the current ear position and the current sound source position is greater than the preset distance threshold, indicating that the ear is not in the optimal noise reduction area of the active noise reduction device 100, perform the step of controlling the direction and distance of movement of the sound emitting device 110 according to the relative position information to adjust the position of the sound emitting device 110 relative to the ear, otherwise, indicating that the ear is in the optimal noise reduction area of the active noise reduction device 100, and the position of the sound emitting device 110 relative to the ear does not need to be adjusted. In some embodiments, the preset distance threshold can be set to 0.5 mm or a similar value, such as 0.3 mm, 0.4 mm, 0.5 mm, or 0.6 mm, etc.

[0053] In some embodiments, the displacement execution mechanism 142 can drive the sound emitting device 110 to move within a range of 0-20 mm, that is, the maximum distance that the sound emitting device 110 can move is designed to be 20 mm. Of course, this is affected by the size of the active noise reduction device 100 and the application scenario, and 20 mm is not necessarily limited.

[0054] In other embodiments, the displacement controller 141 does not need to determine whether the relative distance between the current ear position and the current sound source position is greater than the preset distance threshold, but directly controls the direction and distance of movement of the sound emitting device 110 according to the relative position information to adjust the position of the sound emitting device 110 relative to the ear.

[0055] In some embodiments, the noise reduction controller 150 is further configured to: determine a target height interval in which the current ear height is located from a plurality of pre-divided height intervals, and a plurality of pre-stored noise reduction coefficients correspond to the plurality of pre-divided height intervals one by one; and determine a target noise reduction coefficient pre-stored for the target height interval from the plurality of pre-stored noise reduction coefficients.

[0056] It can be understood that the plurality of pre-stored noise reduction coefficients are pre-obtained and pre-stored in the noise reduction controller 150 by the following steps: for each height interval in the plurality of pre-divided height intervals, when the mannequin is in a state within the height interval, an error signal is obtained by the error microphone arranged at the binaural position of the mannequin, the error signal being formed by the superposition of the noise signal at the binaural position of the mannequin and the secondary sound field generated by the sound generating device 110; the filter coefficient is adjusted according to the error signal, and when the adjusted filter coefficient satisfies the preset convergence condition, the adjusted filter coefficient is taken as the noise reduction coefficient corresponding to the height interval, and the obtained noise reduction coefficient corresponding to each height interval is pre-stored in the noise reduction controller 150 for calling.

[0057] It should be noted that the error microphone only needs to be arranged when the plurality of noise reduction coefficients are measured, that is, the error microphone needs to be used in the test scene, and the error sensor is not needed when the active noise reduction device 100 is used by the user, that is, the error microphone does not need to be installed on the active noise reduction device 100, saving hardware.

[0058] It should be further noted that the current sound source position of the sound generating device 110 and the current ear position need to be defined with the same reference point. In some embodiments, the current ear position and the current sound source position are both defined with respect to the position of a certain infrared sensor 131a selected in the position detection device 130 as the reference point.

[0059] If the current ear position only includes the current ear height, the infrared sensor array 131 is a column of infrared sensors 131a arranged in a straight line parallel to the path of the sound generating device 110 moving up and down relative to the ear. The position of the highest infrared sensor 131a in the column of infrared sensors 131a relative to the ground can be taken as the reference point (the reference point satisfies h=0), and the orientation is in the positive direction of height. For example, assuming that 4 height intervals are divided, 4 sets of filter coefficients need to be obtained one by one, and the value range of h corresponding to the 4 height intervals can be as follows: height interval 1: 5≤h≤0; height interval 2: 15

[0060] If the current human ear position includes both the current human ear height and horizontal position information, the infrared sensor array 131 includes at least one row and at least one column of infrared sensors 131a arranged along the moving path of the sound emitting device 110, and the position of the infrared sensor 131a at the center position can be taken as a reference point. The distance interval needs to be divided in advance, and the noise reduction coefficient corresponding to each distance interval is obtained in advance through testing. The process is the same as or similar to the implementation process of obtaining the noise reduction coefficient corresponding to each height interval, and thus is not described here.

[0061] In some embodiments, the FxLMS (filters-x least mean square) algorithm can be used to continuously adjust the filter coefficients (that is, continuously adjust the filter coefficients based on the least mean square error criterion to approach the optimal solution), and when the preset convergence condition is met, an optimal solution of a set of filter coefficients is obtained. The optimal solution of the set of filter coefficients obtained is the noise reduction coefficient corresponding to the height interval.

[0062] In some embodiments, the noise detection device 120 can be an acceleration sensor or a microphone. The acceleration sensor converts a vibration signal representing the noise around the human ear into an electrical signal, and the microphone converts the sound pressure of the noise around the human ear into an electrical signal, so as to detect the noise around the human ear.

[0063] It can be understood that the sound emitting device 110 in the embodiments of the present application can include one or more loudspeakers, which are arranged towards the position of the human ear.

[0064] In some embodiments, the noise reduction controller 150 is configured to: process the noise around the human ear according to the target noise reduction coefficient to generate a control signal for controlling the sound emitting device 110, so that the sound emitting device 110 generates a secondary sound field having a phase difference with the noise around the human ear under the control of the control signal.

[0065] Based on the same inventive concept, the present application also provides a noise reduction headrest, as shown in Figure 1 、 Figure 2A and Figure 2B , which includes a headrest body 200 and an active noise reduction device 100 arranged on the headrest body 200. The sound emitting device 110 is movably arranged in the headrest body 200 relative to the headrest body 200, and the displacement control device 140 is configured to control the movement of the sound emitting device 110 relative to the headrest body 200 according to the current human ear position obtained from the position detection device 130, so as to drive the sound emitting device 110 to move towards the human ear.

[0066] In some embodiments, the position detection device 130 applied to the noise reduction headrest comprises a position calculation unit and an infrared sensor array 131, and the headrest body 200 has an inner cavity. The infrared sensor array 131 can be fixedly arranged on the outer surface of the headrest body 200, and other components of the active noise reduction device 100 can be arranged in the inner cavity of the headrest body 200 except the infrared sensor array 131.

[0067] It can be understood that, in the case that the displacement execution mechanism 142 comprises a plurality of stages of slide table modules, the guide rail 142a of the lowermost stage of slide table modules is fixed to the inner cavity wall of the headrest body 200. In the case that the displacement execution mechanism 142 comprises a stage of slide table modules, the guide rail 142a of the slide table modules is fixed to the inner cavity wall of the headrest body 200.

[0068] It should be noted that more detailed descriptions of the active noise reduction device 100 in the noise reduction headrest provided by any of the embodiments of the present application can be referred to the descriptions of any of the embodiments of the active noise reduction device 100 described above, and will not be described herein for the sake of brevity.

[0069] In order to fully demonstrate the difference between the noise reduction headrest provided by the embodiments of the present application and the ordinary noise reduction headrest, the road noise played back by a loudspeaker is used as the initial noise, the electrical signal fed to the noise reduction controller 150 by the loudspeaker is used as the reference signal, and the noise reduction coefficient obtained at the origin (h = h4 = 0 cm) is used as the default noise reduction coefficient. The noise reduction amount at the user's ears when there is height grading (that is, when the noise reduction coefficient is matched according to the height interval in which the human ear is located) and the noise reduction amount at the user's ears when there is no height grading (when the same noise reduction coefficient is used) are tested, and the results are shown in Table 1 and Table 2 below. The measured method for calibrating the noise reduction amount is as follows: the mannequin is fixed and does not move, the noise reduction is performed using the noise reduction coefficient matched with the position, and the noise reduction amount is calculated, which is the calibrated noise reduction amount at the position. Figure 6A~6C

[0070] When there is height grading, taking the case that four height intervals are pre-divided (height interval 1: 5≤h≤0; height interval 2: 15<h<5; height interval 3: 25<h≤15; height interval 4: h≤25) as an example, the mannequin is moved in the height direction so that the human ear switches between four height points h1-h4 (h1 = -25 cm, h2 = -20 cm, h3 = -10 cm, h4 = 0 cm). When moving to one of the height points, the noise reduction is performed using the noise reduction coefficient matched with the height interval in which the height point is located, and the noise reduction amount is calculated.

[0071] ​When there is no height grading, the head model is moved in the height direction so that the human ear switches between four height points h1 to h4 corresponding to the four height intervals. The default filter is always used for noise reduction throughout the process, and the noise reduction amount is calculated.

[0072] Table 2. Statistics of noise reduction

[0073]

[0074] Testing shows that height-graded active noise reduction headrests can significantly increase noise reduction. For example, at the left ear position of -25cm, the noise reduction is 0.3dBA without height grading, but 5.7dBA with height grading, effectively improving noise reduction. Figure 6A The left ear spectrum diagram after noise reduction with and without high grading when the human ear is at h4. Figure 6B The change in noise reduction at the left ear before and after turning on height grading; Figure 6C The change in noise reduction at the right ear before and after turning on height grading, from Figure 6A~Figure 6C It can be seen that the highly graded active noise reduction headrest has a better noise reduction effect.

[0075] Based on the same inventive concept, the present invention also provides a noise reduction seat, such as Figure 1 and Figure 3 As shown, the noise reduction seat includes a seat body and an active noise reduction device 100, wherein the active noise reduction device 100 is arranged on the seat body, wherein the seat body has a load-bearing part 310, a backrest part 320 and a headrest part 330, at least the sound-emitting device 110 and the position detection device 130 of the active noise reduction device 100 are arranged on the headrest part 330, and the sound-emitting device 110 is movably arranged on the headrest part 330 relative to the headrest part 330; the displacement control device 140 is used to: control the movement of the sound-emitting device 110 relative to the headrest part 330 according to the current position of the human ear, so as to drive the sound-emitting device 110 to move toward the direction close to the human ear.

[0076] It should be noted that more implementation details of the active noise reduction device 100 in the noise reduction seat provided by any embodiment of the present invention can be referred to any implementation of the above-mentioned embodiments of the active noise reduction device 100. For the sake of brevity of the specification, they will not be repeated here.

[0077] In some embodiments, the position detection device 130 applied to the noise reduction seat comprises a position calculation unit and an infrared sensor array 131, the headrest part 330 has an inner cavity, the infrared sensor array 131 can be fixedly arranged on the outer surface of the headrest part 330, and other components of the active noise reduction device 100 except the infrared sensor array 131: can be arranged in the inner cavity of the headrest part 330 or only the sound generating device 110 is arranged in the inner cavity of the headrest part 330, and the remaining components are arranged in the bearing part 310 or the backrest part 320 of the seat body.

[0078] It can be understood that in the case that the displacement execution mechanism 142 comprises a plurality of stage slide module, the guide rail 142a of the lowermost stage slide module is fixed to the inner cavity wall of the headrest part 330. In the case that the displacement execution mechanism 142 comprises a stage slide module, the guide rail 142a of the slide module is fixed to the inner cavity wall of the headrest part 330.

[0079] Based on the same inventive concept, the present application also provides a vehicle, as shown in Figure 1 and Figure 4 , comprising a passenger cabin (not shown), a seat body and an active noise reduction device 100, the seat body is arranged in the passenger cabin, the seat body comprises a bearing part 310, a backrest part 320 and a headrest part 330, the headrest part 330 is movably connected relative to the backrest part 320; at least a sound generating device 110 is arranged in the headrest part 330; the displacement control device 140 is used for: controlling the headrest part 330 to move relative to the backrest part 320 according to the current ear position, so as to drive the sound generating device 110 to move towards the direction close to the ear. As shown in Figure 4 , when the active noise reduction device 100 is applied to the vehicle, the displacement execution mechanism 142 of the active noise reduction device 100 comprises a stage slide module, the guide rail 142a of the slide module is fixed to the backrest part of the seat body, and the headrest part 320 is arranged on the slide block 142b.

[0080] In some embodiments, when the active noise reduction device 100 is applied to the vehicle, the position detection device 130 comprises a position calculation unit and at least one infrared sensor 131a arranged on the roof of the passenger cabin opposite to the bearing part of the seat body; the position calculation unit is used for determining the current ear position according to the sensing data of the at least one infrared sensor 131a.

[0081] In some embodiments, the infrared sensor 131a arranged on the roof of the passenger compartment is only one infrared ranging sensor or infrared laser radar, and the position calculation unit is configured to determine the current ear height according to the sensing data of the at least one infrared sensor 131a. When the infrared sensor 131a uses an infrared laser radar, the infrared laser radar is used to scan the roof of the passenger compartment, and based on the ranging results of the radar-based scanning and the ranging limit and scanning angle of the radar, the current ear height is obtained.

[0082] In some embodiments, the infrared sensor 131a arranged on the roof of the passenger compartment includes a plurality of arrayed infrared sensors, and the position calculation unit is configured to determine the current ear height and horizontal position information according to the sensing data of the arrayed infrared sensors 131a.

[0083] It should be noted that more implementation details of the active noise reduction device 100 in the vehicle provided by any one of the embodiments of the present application can be referred to the description of any one of the above-mentioned embodiments of the active noise reduction device 100. For the sake of brevity of the description, the details are not repeated here.

[0084] The present application also provides an active noise reduction control method applied to the active noise reduction device 100 with the sound generating device 110. More implementation details of the active noise reduction device 100 in the active noise reduction control method provided by any one of the embodiments of the present application can be referred to the description of any one of the above-mentioned embodiments of the active noise reduction device 100. As shown in the figure, the active noise reduction control method comprises the following steps S101-S103: Figure 5

[0085] S101: obtaining the ear surrounding noise and the current ear position;

[0086] S102: controlling the sound generating device 110 to move towards the direction close to the ear according to the current ear position;

[0087] S103: determining the target noise reduction coefficient matched with the current ear position from the pre-stored plurality of noise reduction coefficients;

[0088] S104: controlling the sound generating device 110 to generate a secondary sound field according to the target noise reduction coefficient and the ear surrounding noise, so as to at least partially offset the ear surrounding noise.

[0089] In some embodiments, the step of controlling the sound generating device 110 to move towards the direction close to the ear according to the current ear position comprises: obtaining the current sound source position of the sound generating device 110; determining the relative position information between the current ear position and the current sound source position; and controlling the direction and distance of the movement of the sound generating device 110 according to the relative position information, so as to make the sound generating device 110 move towards the direction close to the ear.

[0090] ​In some embodiments, the relative position information includes a relative distance and a relative direction, and the step of controlling the direction and distance of the sound emitting device 110 to move according to the relative position information includes: if the relative distance between the current ear position and the current sound source position is greater than a preset distance threshold, performing the step of controlling the direction and distance of the sound emitting device 110 to move according to the relative position information.

[0091] In some embodiments, the current ear position includes a current ear height, and the target noise reduction coefficient matched with the current ear position is determined from a plurality of pre-stored noise reduction coefficients: a target height interval in which the current ear height is located is determined from a plurality of pre-divided height intervals, and the plurality of pre-stored noise reduction coefficients correspond to the plurality of pre-divided height intervals one by one; and a target noise reduction coefficient pre-stored for the target height interval is determined from the plurality of pre-stored noise reduction coefficients.

[0092] In some embodiments, the target noise reduction coefficient is used to process the ambient noise around the ear to generate a control signal for controlling the sound emitting device 110, so that the sound emitting device 110 generates a secondary sound field having a phase difference with the ambient noise around the ear under the control of the control signal.

[0093] In some embodiments, the plurality of pre-stored noise reduction coefficients are obtained by the following steps: for each height interval in the plurality of pre-divided height intervals, an error microphone arranged at the binaural position of the human head model is used to obtain an error signal under the condition that the human head model is in the height interval, the error signal is formed by superimposing the noise signal of the binaural position of the human head model and the secondary sound field generated by the sound emitting device 110; and the filter coefficient is adjusted according to the error signal, and the adjusted filter coefficient is taken as the noise reduction coefficient corresponding to the height interval when the adjusted filter coefficient satisfies a preset convergence condition.

[0094] The active noise reduction control method described above can be implemented based on the active noise reduction device 100 described above, and therefore, more implementation details of the active noise reduction control method embodiment can refer to the description in the active noise reduction device 100 embodiment described above, and will not be described here again for the sake of brevity of the description.

[0095] According to one or more embodiments of the present application, the ear is positioned, and the sound emitting device is controlled to move closer to the ear according to the ear position, so that the sound emitting device tracks the ear position, and the ear is always in the best noise reduction area, so as to accurately reduce the noise around the ear, and the noise reduction coefficient matched with the ear position is used to adapt to the ear position to generate a secondary sound field, so that the phase difference between the generated secondary sound field and the ambient noise around the ear is more opposite, which can effectively improve the noise reduction amount. Therefore, the active noise reduction device provided by the embodiments of the present application can improve the noise reduction effect.

[0096] The present application is described in reference to the flowchart and / or block diagram of the method, apparatus (system) and computer program product according to an embodiment of the present application. It is understood that each flow and / or block in the flowchart and / or block diagram, and a combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, a special purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more flows and / or blocks. Figure 1 one or more blocks or blocks.

[0097] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction apparatus that implements the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more flows and / or blocks. Figure 1 one or more blocks or blocks.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart and / or block diagram block or blocks. Figure 1 one or more flows and / or blocks. Figure 1 Figure 1 one or more blocks or blocks.

[0099] Although preferred embodiments of the application have been described, those skilled in the art will recognize that additional modifications and variations can be made thereto without departing from the spirit and scope of the application. It is therefore intended that the appended claims cover all such modifications and variations as fall within the true scope of the application.

[0100] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

[0101] The above description is only the preferred embodiment of the present application but not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art without departing from the spirit and scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. An active noise reduction device, characterized by, The application comprises: a sound emitting device; a noise detecting device for detecting the noise around the human ear; a position detecting device for detecting the current position of the human ear; a displacement control device electrically connected with the position detecting device and the sound emitting device, the displacement control device being used to control the sound emitting device to move towards the human ear according to the current position of the human ear; a noise reduction controller electrically connected with the sound emitting device, the noise detecting device and the position detecting device, the noise reduction controller being used to determine the target noise reduction coefficient matching the current position of the human ear from the pre-stored multiple noise reduction coefficients, and control the sound emitting device to generate the secondary sound field according to the target noise reduction coefficient and the noise around the human ear, so as to at least partially offset the noise around the human ear.

2. The active noise reduction device of claim 1, wherein, The displacement control device comprises: a displacement controller electrically connected with the position detecting device; a displacement execution mechanism electrically connected with the displacement controller, the sound emitting device being arranged in the displacement execution mechanism, or the sound emitting device being connected with the displacement execution mechanism through a transmission mechanism; wherein the displacement controller is used to acquire the current position of the human ear from the position detecting device, and control the displacement execution mechanism to move according to the current position of the human ear, so as to drive the sound emitting device to move towards the human ear.

3. The active noise reduction device of claim 2, wherein, The displacement controller is used to: acquire the current sound source position of the sound emitting device; determine the relative position information between the current position of the human ear and the current sound source position; control the direction and distance of the movement of the displacement execution mechanism according to the relative position information.

4. The active noise reduction device of claim 1, wherein, The noise reduction controller is used to: determine the target height interval in which the current height of the human ear is located from the pre-divided multiple height intervals, the pre-stored multiple noise reduction coefficients corresponding to the pre-divided multiple height intervals one by one, the current position of the human ear including the current height of the human ear; determine the target noise reduction coefficient pre-stored for the target height interval from the pre-stored multiple noise reduction coefficients.

5. The active noise reduction device of claim 1, wherein, The position detecting device comprises: an infrared sensor array, the infrared sensor array comprising at least one column of infrared sensors, wherein the layout path of each column of infrared sensors is parallel to the movement path of the sound emitting device; a position calculation unit used to determine the current position of the human ear according to the sensing data of the infrared sensor array.

6. A noise reducing headrest, characterized by, The application comprises: a headrest body and the active noise reduction device as claimed in any one of claims 1-5, the active noise reduction device being arranged in the headrest body, wherein the sound emitting device is movably arranged in the headrest body relative to the headrest body; the displacement control device is used to control the sound emitting device to move relative to the headrest body according to the current position of the human ear acquired from the position detecting device, so as to drive the sound emitting device to move towards the human ear.

7. A noise reducing seat, characterized in that The application comprises: The seat body and the active noise reduction device as claimed in any one of claims 1-5 are arranged in the seat body, wherein the seat body has a bearing part, a backrest part and a headrest part, at least the sound emitting device and the position detecting device of the active noise reduction device are arranged in the headrest part, and the sound emitting device is movable relative to the headrest part; The displacement control device is configured to control the movement of the sound emitting device relative to the headrest part according to the current ear position obtained from the position detecting device, so as to drive the sound emitting device to move towards the ear.

8. A vehicle characterized by comprising: The method comprises: an occupant compartment; a seat body arranged in the occupant compartment, wherein the seat body comprises a bearing part, a backrest part and a headrest part, the headrest part is movably connected relative to the backrest part; The active noise reduction device as claimed in any one of claims 1-4, at least the sound emitting device of the active noise reduction device is arranged in the headrest part; The displacement control device is configured to control the movement of the headrest part relative to the backrest part according to the current ear position, so as to drive the sound emitting device to move towards the ear.

9. The vehicle of claim 8, wherein, The position detecting device of the active noise reduction device comprises: at least one infrared sensor arranged on the roof of the occupant compartment and opposite to the bearing part of the seat body; a position calculation unit configured to determine the current ear position according to the sensing data of the at least one infrared sensor.

10. An active noise control method applied to an active noise control device having a sound emitting device, characterized in that, The method comprises: obtaining the ambient noise around the ear and the current ear position; controlling the sound emitting device to move towards the ear according to the current ear position; determining a target noise reduction coefficient matching the current ear position from a plurality of pre-stored noise reduction coefficients; controlling the sound emitting device to generate a secondary sound field according to the target noise reduction coefficient and the ambient noise around the ear, so as to at least partially offset the ambient noise around the ear.

11. The active noise reduction control method of claim 10, wherein, The method comprises: obtaining the current sound source position of the sound emitting device; determining relative position information between the current ear position and the current sound source position; controlling the direction and distance of the movement of the sound emitting device according to the relative position information, so as to drive the sound emitting device to move towards the ear.

12. The active noise reduction control method of claim 11, wherein, The relative position information comprises relative distance and relative direction, and the step of controlling the direction and distance of the movement of the sound emitting device according to the relative position information comprises: if the relative distance between the current ear position and the current sound source position is greater than a preset distance threshold, performing the step of controlling the direction and distance of the movement of the sound emitting device according to the relative position information.

13. The active noise reduction control method of claim 10, wherein, The current ear position comprises a current ear height, and the step of determining a target noise reduction coefficient matching the current ear position from a plurality of pre-stored noise reduction coefficients comprises: determining a target height interval in which the current ear height is located from a plurality of pre-divided height intervals, the plurality of pre-stored noise reduction coefficients correspond to the plurality of pre-divided height intervals one by one; determining a target noise reduction coefficient pre-stored for the target height interval from the plurality of pre-stored noise reduction coefficients.

14. The active noise reduction control method of claim 13, wherein, The pre-stored plurality of noise reduction coefficients are obtained in advance by the following steps: For each height interval of the plurality of height intervals, when the mannequin is in a state within the height interval, an error microphone disposed at a binaural position of the mannequin is used to obtain an error signal, which is formed by superimposing a noise signal at the binaural position of the mannequin and a secondary sound field generated by the sound generating device; The filter coefficients are adjusted according to the error signal, and when the adjusted filter coefficients satisfy a preset convergence condition, the adjusted filter coefficients are taken as the noise reduction coefficient corresponding to the height interval.

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