KR20220165931A - An active noise control device for vehicle - Google Patents

Abstract

The present invention provides an active noise control device for a vehicle, comprising: a head position estimating module for detecting a driver seated on a driver seat of a vehicle to estimate the head position or the ear position of the driver, detecting the entire noise of the vehicle including vehicle noise for the vehicle, noise inside and outside the vehicle generated from the inside of the vehicle and the vehicle noise to generate a vehicle noise signal and a signal of the noise inside and outside the vehicle, and outputting echo waves for canceling the noise inside and outside the vehicle to the estimated head position; and a signal processing module electrically connected to the head position estimating module, generating an echo wave signal by processing the vehicle noise signal and the entire vehicle noise signal transmitted from the head position estimating module, and transmitting the same to the head position estimating module. Therefore, a noise canceling effect can be maximized.

Description

Active noise control device for vehicle {An active noise control device for vehicle}

The present invention relates to an active noise control device for a vehicle, and more particularly, to an active noise control device for a vehicle that maximizes a noise canceling effect by outputting an echo to a driver's head or ear.

As a way to increase vehicle driving convenience, research on technology for removing noise in a vehicle is active. On the other hand, when a method of reducing the weight of the vehicle body is applied to improve fuel efficiency of the vehicle, passive damping materials to prevent the inflow of noise outside the vehicle and noise generated by the vehicle itself (hereinafter referred to as vehicle interior and exterior noise) into the driver's seat There is a problem to reduce the use of .

Such noise inside and outside the vehicle causes driver fatigue and, in severe cases, causes headaches and hearing impairment. To this end, active noise control (ANC) technology is applied to vehicles in order to reduce noise inside and outside the vehicle without adversely affecting fuel efficiency.

On the other hand, in order to solve the driver's inconvenience in operating functions due to the advancement of vehicle functions, technologies enabling vehicle manipulation and control through driver voice recognition are being developed and applied. In relation to this, conventional technologies related to vehicle voice recognition use complex software pre-processing technology to receive both interior and exterior noise and driver's voice and extract only the driver's voice from among them.

However, due to the increase in the load of the vehicle control system due to such complex software preprocessing technology, processing of other vehicle application services may be delayed. Therefore, in the recent automobile environment where voice recognition-based control is increased, vehicle control Processing delays in the system can cause serious problems related to vehicle safety. Moreover, the conventional in-vehicle noise reduction technology is not for voice recognition, but for providing a comfortable driving environment by reducing overall noise inside and outside the vehicle, so there is a problem in that it does not help to improve the voice recognition rate.

In addition, the prior art described above requires consultation with relevant departments for each location in order to install a sensor for detecting noise in a desired installation space in a vehicle, and since the speaker installed in the vehicle must be used, the location of the speaker may be changed. There was a problem that tuning had to be done in consultation with the relevant departments each time.

In addition, in the prior art, if the electric wire for connecting the sensor and the controller is long, there is a problem such as causing another noise or being disconnected according to noise other than noise or contact with surrounding objects.

In addition, as the head position of the driver and occupant seated in the vehicle moves and the higher the frequency, the wavelength becomes shorter, and the performance of the active noise control (ANC) decreases when it is out of the initially set position, so the movement and angle of the seat However, it is necessary to develop technology that performs noise canceling in consideration of the occupant's head position.

(Patent Document 1) Patent Publication No. 10-2021-0019908 (2021.02.23.)

(Patent Document 2) Patent Publication No. 10-2020-0119940 (2020.10.21.)

An object of the present invention for solving the above problem is to estimate the position of the driver's head or ears in the head position estimation unit, and the signal processing module generates an echo signal based on the vehicle noise and the overall vehicle noise measured by the noise sensor unit. To provide an active noise control device for a vehicle in which a control unit controls a sound output unit so that an echo wave is output to the driver's head or ear based on head position information or ear position information.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

The configuration of the present invention for achieving the above object is to detect a driver seated in a driver's seat of a vehicle, estimate the driver's head position or ear position, and detect vehicle noise for the vehicle, inside and outside the vehicle generated inside the vehicle. a head position estimating module that detects noise and vehicle noise including the vehicle noise, generates a vehicle noise signal and vehicle interior/external noise signals, and outputs an echo wave to the estimated head position to cancel out the vehicle interior/external noise; and a signal processing module that is electrically connected to the head position estimating module and generates an echo signal obtained by processing the vehicle noise signal and the overall vehicle noise signal transmitted from the head position estimating module and transmits the signal to the head position estimating module. It provides an active noise control device for a vehicle, characterized in that it comprises.

In an embodiment of the present invention, a headrest body including a headrest body accommodating the head position estimation module and a pair of fixing bars formed on the lower portion of the headrest body and detachable from the upper portion of the driver's seat seat; further included. And, it may be characterized in that the head position estimation module is an integral type applied to the headrest.

In an embodiment of the present invention, the head position estimation module includes at least a pair of vehicle noise sensors, at least partially exposed to the outside, detecting the vehicle noise generated in the vehicle itself and generating the vehicle noise signal; A noise sensor unit including a pair of error sensors, a part of which is exposed to the outside and which detects the overall vehicle noise and generates the overall vehicle noise signal, wherein the pair of vehicle noise sensors and the pair of error sensors are included. The sensor may transmit the vehicle noise signal and the overall vehicle noise signal to the signal processing module.

In an embodiment of the present invention, the head position estimating module, at least partially exposed to the outside facing the driver's head, transmits and receives ultrasonic waves or electromagnetic waves toward the driver's head to generate a plurality of position signals; A plurality of position sensor units arranged in a matrix spaced apart by a predetermined distance; and a head position estimator configured to generate head position information obtained by estimating the head position of the driver by comparing strengths of the plurality of position signals transmitted from the plurality of position sensor units.

In an embodiment of the present invention, the signal processing module receives the vehicle noise signal transmitted from the pair of vehicle noise sensors and the total vehicle noise signal transmitted from the pair of error sensors to obtain the least square mean ( A signal processing unit that generates a corresponding signal by applying an LMS: Least Mean Square (LMS) algorithm; and an analog filter unit electrically connected to the signal processing unit and generating the echo signal by filtering the corresponding signal transmitted from the signal processing unit, wherein at least a part of the head position estimation module is exposed to the outside. a pair of sound output units outputting the echo waves toward the driver's head; and a controller for controlling the operation of the pair of sound output units according to the echo signal transmitted from the analog filter unit and outputting the echo wave toward the driver's head based on the head position information. that can be characterized.

In an embodiment of the present invention, a headrest body accommodating the noise sensor unit and the sound output unit provided in the head position estimation module, and a pair of fixings formed on the lower portion of the headrest body and detachable from the upper portion of the driver's seat seat A headrest including a bar; and a detachable module accommodating a position sensor unit, a head position estimation unit, and a control unit provided in the head position estimation module and detachable from the pair of fixing bars, wherein the noise sensor unit and the sound output unit are included in the headrest. and the position sensor unit, the head position estimating unit, and the control unit may be of a separate type applied to the detachable module.

In an embodiment of the present invention, the noise sensor unit includes: a pair of vehicle noise sensors, at least partially exposed to the outside, detecting the vehicle noise generated from the vehicle itself and generating the vehicle noise signal; and a pair of error sensors, at least partially exposed to the outside, detecting the overall vehicle noise and generating the overall vehicle noise signal, wherein the pair of vehicle noise sensors and the pair of error sensors transmit the signal It may be characterized in that the vehicle noise signal and the overall vehicle noise signal are transmitted to the processing module.

In an embodiment of the present invention, the position sensor unit is at least partially exposed to the outside so as to face the driver's head, and generates coordinate information by measuring a position where the headrest body and the back of the driver's head come into contact. can do.

In an embodiment of the present invention, the head position estimator generates ear position information by estimating the position of the driver's ears by applying the coordinate information transmitted from the position sensor unit to an inverse kinematics algorithm. can be done with

In an embodiment of the present invention, the inverse kinematics algorithm is based on the average distance from the back of the head to the ears based on an adult of a standard body shape, the average distance from the shoulder to the seat based on an adult of a standard body shape, and an adult of a standard body shape It may be characterized in that the average length of the neck and the average length from the neck to the ears based on an adult of a standard body type are pre-stored and used to estimate the position of the driver's ears.

In an embodiment of the present invention, the signal processing unit receives the vehicle noise signal transmitted from the pair of vehicle noise sensors and the total vehicle noise signal transmitted from the pair of error sensors to obtain a least square mean (LMS: Least Mean Square) algorithm may be applied to generate a corresponding signal.

In an embodiment of the present invention, the analog filter unit may be electrically connected to the signal processing unit to generate the echo signal by filtering the corresponding signal transmitted from the signal processing unit.

In an embodiment of the present invention, at least a part of the pair of sound output units is exposed to the outside and outputs the echo waves toward the driver's ears, and the control unit responds to the echo signal transmitted from the analog filter unit. Accordingly, operations of the pair of sound output units may be controlled to output the echo waves toward the driver's ears based on the ear position information.

The effect of the present invention according to the configuration as described above is that the head position estimation unit estimates the position of the driver's head or ears, and the signal processing module generates an echo signal based on the vehicle noise and the overall vehicle noise measured by the noise sensor unit. The noise canceling effect can be maximized by controlling the sound output unit so that the echo wave is output to the driver's head or ear based on head position information or ear position information.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a conceptual diagram showing an active noise control device for a vehicle according to first and second embodiments of the present invention.
2 is a block diagram showing an active noise control device for a vehicle according to first and second embodiments of the present invention.
3 is a perspective view from one direction showing an active noise control device for a vehicle according to a first embodiment of the present invention.
4 is a diagram illustrating defuzzification for estimating a driver's head position in a head position estimator provided in an active noise control device for a vehicle according to a first embodiment of the present invention.
5 is a graph showing that a plurality of position sensor units at different positions provided in the active noise control device for a vehicle according to the first embodiment of the present invention have different sensor intensities.
6 is a perspective view from one direction showing an active noise control device for a vehicle according to a second embodiment of the present invention.
7 is a diagram related to inverse kinematics for estimating a driver's ear position in a head position estimator provided in an active noise control device for a vehicle according to a second embodiment of the present invention.
FIG. 8 is a diagram illustrating estimating a driver's ear position by a head position estimating unit provided in an active noise control device for a vehicle according to a second embodiment of the present invention.
9(a) and (b) are graphs showing simulation results of an inverse kinematics algorithm to which a driver's viewing direction is applied in the head position estimation unit provided in the active noise control device for a vehicle according to the second embodiment. to be.
10 is a perspective view from one direction illustrating a noise canceling test of the active noise control device for a vehicle according to the first embodiment of the present invention.
11(a) and (b) are graphs showing the noise canceling effect of the active noise control device for a vehicle according to the first embodiment.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected (connected, contacted, combined)" with another part, this is not only "directly connected", but also "indirectly connected" with another member in between. "Including cases where In addition, when a part "includes" a certain component, it means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as "include" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, an active noise control device for a vehicle according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 5 .

1 is a conceptual diagram showing an active noise control device for a vehicle according to first and second embodiments of the present invention. 2 is a block diagram showing an active noise control device for a vehicle according to first and second embodiments of the present invention.

1 and 2, an active noise control device 500 for a vehicle according to a first embodiment of the present invention includes a headrest 100, a head position estimation module 200, and a signal processing module 400. .

In addition, the active noise control device 500 for a vehicle according to the first embodiment of the present invention is characterized in that the head position estimation module 200 is an integral type applied to the headrest 100.

3 is a perspective view from one direction showing an active noise control device for a vehicle according to a first embodiment of the present invention.

Referring to FIG. 3 , the headrest 100 includes a headrest body 110 and a fixing bar 120 .

The headrest body 110 is positioned on top of a driver's seat for a driver to sit on in a vehicle and supports the driver's head. The headrest body 110 for this purpose may be formed in an arch shape to correspond to the back of the driver's head, and may be made of a soft material to provide a cushioning feeling to the driver.

In addition, at least a portion of the fixing bar 120 is accommodated inside the headrest body 110 .

The above headrest body 110 accommodates the head position estimation module 200.

The fixing bar 120 is formed on the lower part of the headrest body 110 and is detachable from the upper part of the driver's seat.

In detail, at least a part of the fixing bar 120 is fixed to the inside of the headrest body 110 and the remaining part is exposed to the outside of the headrest body 110 .

In addition, the fixing bar 120 is composed of a pair and has a structure that is inserted into and detachable from the top of the driver's seat.

The head position estimating module 200 detects a driver seated on a driver's seat of a vehicle and estimates a position of the driver's head or ears.

In more detail, the head position estimation module 200 detects vehicle noise, vehicle interior and exterior noise generated inside the vehicle, and overall vehicle noise including vehicle noise, generates a vehicle noise signal and vehicle interior and exterior noise signals, and generates a vehicle noise signal. Echo waves for canceling internal and external noise are output to the estimated head position.

The head position estimation module 200 for this purpose includes a noise sensor unit 210, a position sensor unit 220, a head position estimation unit 230, a sound output unit 240, and a control unit 250.

The noise sensor unit 210 includes a vehicle noise sensor 211 and an error sensor 212 .

At least a part of the vehicle noise sensor 211 is exposed to the outside and generates a vehicle noise signal by detecting vehicle noise generated from the vehicle itself.

In addition, the vehicle noise sensors 211 are formed as a pair on both sides of the headrest body 110, where the pair of vehicle noise sensors 211 include a first vehicle noise sensor 211a and a second vehicle noise sensor ( 211b).

The vehicle noise sensor 211 described above includes a first vehicle noise sensor 211a and a second vehicle noise sensor 211b.

The first vehicle noise sensor 211a is formed on one side of the headrest body 110 (=adjacent to the driver's ear located on one side) to generate vehicle noise (= noise generated by the vehicle itself, exemplarily engine, Noise generated from vehicle components such as air conditioners and heaters) is measured.

The second vehicle noise sensor 211b is formed on the other side of the headrest body 110 (= adjacent to the driver's ear located on the other side) to generate vehicle noise (= noise generated by the vehicle itself, exemplarily engine, Noise generated from vehicle components such as air conditioners and heaters) is measured.

At least a part of the error sensor 212 is exposed to the outside and detects the overall vehicle noise to generate an overall vehicle noise signal.

In addition, the error sensor 212 is formed as a pair on both sides of the headrest body 110 adjacent to the first and second vehicle noise sensors 211a and 211b, where the pair of error sensors 212 generate a first error. A sensor 212a and a second error sensor 212b.

The above error sensor 212 includes a first error sensor 212a and a second error sensor 212b.

The first error sensor 212a is formed on one side of the headrest body 110 adjacent to the first vehicle noise sensor 211a (= adjacent to the driver's ear located on one side) to measure overall vehicle noise.

Here, the overall vehicle noise includes vehicle noise and vehicle interior and exterior noise, and vehicle interior and exterior noise includes all noises except vehicle noise (= exemplarily, the sound of conversations of people seated inside the vehicle, sound according to movement, and driving of the vehicle). generated road noise, wind noise, etc.).

The second error sensor 212b is formed on the other side of the headrest body 110 adjacent to the second vehicle noise sensor 212b (= adjacent to the driver's ear located on the other side) to measure overall vehicle noise.

The aforementioned pair of vehicle noise sensors 211a and 211b and the pair of error sensors 212a and 212b transmit the vehicle noise signal and the overall vehicle noise signal to the signal processing module 400 .

Referring to FIG. 3 , at least a portion of the position sensor unit 220 is exposed to the outside to face the driver's head. Specifically, the position sensor unit 220 is disposed to face the back of the driver's head.

In more detail, the position sensor unit 220 is formed in plurality so as to be arranged in a matrix spaced apart from each other by a predetermined distance.

The plurality of position sensor units 220 transmit and receive ultrasonic waves or electromagnetic waves toward the driver's head to generate a plurality of position signals.

At this time, the plurality of position sensor units 220 transmit ultrasonic waves or electromagnetic waves generated at different locations toward the back of the driver's head so that they are parallel to each other.

Accordingly, since the ultrasonic waves or electromagnetic waves have different distances and required times from the plurality of position sensor units 220 to the backs of the drivers, the sensor strength of the ultrasonic waves or electromagnetic waves also differs from each other.

4 is a diagram illustrating defuzzification for estimating a driver's head position in a head position estimator provided in an active noise control device for a vehicle according to a first embodiment of the present invention. 5 is a graph showing that a plurality of position sensor units at different positions provided in the active noise control device for a vehicle according to the first embodiment of the present invention have different sensor intensities.

Referring to FIGS. 4 and 5 , the head position estimator 230 compares the intensities of a plurality of position signals transmitted from a plurality of position sensor units 220 (= sensor strength in FIG. 5 ) to determine the driver's head position. Estimated head position information is generated.

Referring to FIGS. 3 and 5 exemplarily, the first position sensor unit located at (1, 1) (lowest left in FIG. 3) and the second position sensor unit located at (1, 2) (left center in FIG. 3) ), (1, 3), the third position sensor unit (upper left in FIG. 3) has different strengths of position signals as shown in FIG.

At this time, the position signal of the third position sensor unit is relatively the strongest, and the position signal of the first position sensor unit is relatively weak.

The above result means that the back of the driver facing the third position sensor unit located at (1, 3) is the closest, and the back of the driver facing the first position sensor unit located at (1, 1) is the closest. means far away

As described above, the head position estimating unit 230 estimates the position of the driver's head by detecting which position sensor unit the back of the driver's head is close to according to the strength of the position signal (= sensor strength).

At least a part of the sound output unit 240 is exposed to the outside and outputs an echo wave toward the driver's head.

Specifically, the sound output unit 240 is disposed as a pair on both sides of the headrest body 110 so as to be adjacent to the vehicle noise sensor 211 and the error sensor 212 .

The above audio output unit 240 includes a first audio output unit 241 and a second audio output unit 242 .

The first sound output unit 241 is formed on one side of the headrest body 110 adjacent to the first vehicle noise sensor 211a and the first error sensor 212a (=adjacent to the driver's ear located on one side) to generate an echo wave outputs

The second sound output unit 242 is formed on the other side of the headrest main body 110 adjacent to the second vehicle noise sensor 211b and the second error sensor 212b (= adjacent to the driver's ear located on the other side), and generates an echo wave. outputs

Here, the echo wave is generated according to the echo signal transmitted from the signal processing module 400 to the control unit 250.

The control unit 250 controls the operation of the pair of audio output units 241 and 242 according to the echo signal transmitted from the analog filter unit 410 to be described later, and sends the echo wave to the driver's head based on head position information. output towards

The signal processing module 400 is electrically connected to the head position estimating module 200 and generates an echo signal obtained by processing the vehicle noise signal and the overall vehicle noise signal transmitted from the head position estimating module 200 to generate a head position estimating module. Send to (200).

The signal processing module 400 for this may be accommodated inside the headrest 100 or mounted inside the vehicle, and includes an analog filter unit 410 and a signal processing unit 420.

The analog filter unit 410 is electrically connected to the signal processing unit 420 and filters a corresponding signal transmitted from the signal processing unit 420 to generate an echo signal.

The signal processing unit 420 receives the vehicle noise signal transmitted from the pair of vehicle noise sensors 211a and 211b and the overall vehicle noise signal transmitted from the pair of error sensors 212a and 212b to obtain the least square mean (LMS: Least Mean Square) algorithm is applied to generate a corresponding signal.

In addition, the signal processing unit 420 transmits the generated corresponding signal to the analog filter unit 410.

Hereinafter, an active noise control device for a vehicle according to a second embodiment of the present invention will be described with reference to FIGS. Make reference to the foregoing, and describe in detail other technical features.

6 is a perspective view from one direction showing an active noise control device for a vehicle according to a second embodiment of the present invention.

Active noise control device 500 for a vehicle according to the second embodiment of the present invention further includes a detachable module 300 than the active noise control device 500 for a vehicle according to the first embodiment, and includes a noise sensor unit 210 and There is a difference in that the sound output unit 240 is applied to the headrest 100 and the position sensor unit 220, the head position estimation unit 230 and the control unit 250 are a separate type applied to the detachable module 300. .

1, 2 and 6, an active noise control device 500 for a vehicle according to a second embodiment of the present invention includes a headrest 100, a head position estimation module 200, a detachable module 300, and It includes a signal processing module 400.

The headrest 100 is formed on a headrest body 110 accommodating the noise sensor unit 210 and the sound output unit 240 provided in the head position estimation module 200 and the lower portion of the headrest body 110. It includes a pair of fixing bars 120 detachable from the top of the driver's seat.

The headrest 100 described above differs from the first embodiment only in that it accommodates only the noise sensor unit 210 and the sound output unit 240, and other shapes and coupling relationships are the same as those of the first embodiment. Note the bar.

The noise sensor unit 210 is at least partially exposed to the outside, and a pair of vehicle noise sensors 211a and 211b for detecting vehicle noise generated from the vehicle itself and generating a vehicle noise signal, and at least a portion of the vehicle noise sensor unit 210 is exposed to the outside. A pair of error sensors 212a and 212b are included to sense overall vehicle noise and generate an overall vehicle noise signal.

The pair of vehicle noise sensors 211a and 211b and the pair of error sensors 212a and 212b transmit the vehicle noise signal and the overall vehicle noise signal to the signal processing module 400, and the noise sensor unit 210 ) is the same as that of the first embodiment, so reference is made to the foregoing for a detailed description.

At least a portion of the position sensor unit 220 is exposed to the outside so as to face the driver's head, and measures a position where the headrest body 110 and the back of the driver come into contact to generate coordinate information.

In addition, the position sensor unit 220 transmits the generated coordinate information to the head position estimation unit 230 .

7 is a diagram related to inverse kinematics for estimating a driver's ear position in a head position estimator provided in an active noise control device for a vehicle according to a second embodiment of the present invention.

The head position estimator 230 applies coordinate information transmitted from the position sensor unit 220 to an inverse kinematics algorithm to generate ear position information by estimating the driver's ear position.

Specifically, the head position estimator 230 estimates the shape of the model using inverse kinematics as shown in FIG. 7 .

7, l1 is the length of the driver's neck, l2 is the length of the driver's head, θ1 is the angle of the neck relative to the ground, θ2 is the angle of the head relative to the ground, the x-axis is the left and right direction of the vehicle, the y-axis is the height direction of the vehicle, z The axis refers to the forward and backward direction of the vehicle.

In relation to the above, the equation for estimating the shape of the model using inverse kinematics is as follows.

FIG. 8 is a diagram illustrating estimating a driver's ear position by a head position estimating unit provided in an active noise control device for a vehicle according to a second embodiment of the present invention.

In addition, the inverse kinematics algorithm is based on the average distance from the back of the head to the ears based on the adult of the standard body shape shown in FIG. 8, the average distance from the shoulder to the seat based on the adult of the standard body shape, and the neck The average length from the neck to the ears based on the average length of the standard body type is pre-stored and used to estimate the position of the driver's ears.

The head position estimator 230 according to the above generates ear position information for the driver's ear position and transmits it to the controller 250.

9(a) and (b) are graphs showing simulation results of an inverse kinematics algorithm to which a driver's viewing direction is applied in the head position estimation unit provided in the active noise control device for a vehicle according to the second embodiment. to be.

As shown in (a) and (b) of FIG. 9 , the head position estimator 230 detects the driver's back of the head (back of the head) and ears when the driver looks up and when the driver looks forward. coordinates can be estimated.

At least a part of the pair of sound output units 241 and 242 is exposed to the outside and outputs the echo waves toward the driver's ears, thereby canceling vehicle noise and overall vehicle noise to cancel noise.

Additionally, the first and second sound output units 241 and 242 may receive the driver's ear position information from the head position estimator 230 and rotate to face the driver's ears based on the received ear position information. For this purpose, the first and second sound output units 241 and 242 may have a tilting structure.

The control unit 250 controls the operation of the pair of sound output units 241 and 242 according to the echo signal transmitted from the analog filter unit 410, and outputs the echo wave toward the driver's ears based on ear position information. let it

At this time, the controller 250 may control the first and second audio output units 241 and 242 to rotate so that the first and second audio output units 241 and 242 face the driver's ears based on the ear position information. there is.

The detachable module 300 accommodates the position sensor unit 220, the head position estimation unit 230, and the control unit 250 provided in the head position estimation module 200 and is detachable from a pair of fixing bars 120. .

The signal processing module 400 may be accommodated in any one of the headrest 100 and the detachable module 300 or mounted inside the vehicle, and includes such an analog filter unit 410 and a signal processing unit 420.

The analog filter unit 410 is electrically connected to the signal processing unit 420 and filters a corresponding signal transmitted from the signal processing unit 420 to generate an echo signal.

The signal processing unit 420 receives the vehicle noise signal transmitted from the pair of vehicle noise sensors 211a and 211b and the overall vehicle noise signal transmitted from the pair of error sensors 212a and 212b to obtain the least square mean (LMS: Least Mean Square) algorithm is applied to generate a corresponding signal.

10 is a perspective view from one direction illustrating a noise canceling test of the active noise control device for a vehicle according to the first embodiment of the present invention.

In order to test noise canceling, as shown in FIG. 10 , the vehicle active noise control device 500 according to the first embodiment of the present invention is mounted on a driver's seat, and the driver's ears are positioned on both sides of the headrest 100. A microphone 10 for performance evaluation is installed and a noise source 20 outputting recorded noise is placed around the driver's seat.

11(a) and (b) are graphs showing the noise canceling effect of the active noise control device for a vehicle according to the first embodiment.

Results of performing active noise control as shown in FIG. 10 are shown in FIGS. 11 (a) and (b).

Specifically, FIG. 11 (a) shows noise when active noise control (ANC) is performed on the driver's left ear and noise when active noise control is not performed, and FIG. 11 (b) shows active noise control (ANC) on the driver's right ear. Noise when noise control (ANC) is performed and noise when active noise control is not performed are shown.

The noise canceling test was conducted three times in total.

As a result of the test, it can be confirmed that when the active noise control device for a vehicle according to the first embodiment of the present invention is operated, the noise is lower by up to about 10 db in a band of 500 Hz or less than when the active noise control is not performed.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

100: headrest
110: headrest body
120: fixed bar
200: head position estimation module
210: noise sensor unit
211: vehicle noise sensor
211a: first vehicle noise sensor
212b: second vehicle noise sensor
212: error sensor
212a: first error sensor
212b: second error sensor
220: position sensor unit
230: head position estimation unit
240: sound output unit
241: first sound output unit
242: second sound output unit
250: control unit
300: detachment module
400: signal processing module
410: analog filter unit
420: signal processing unit
500: vehicle active noise control device

Claims (13)

Detects the driver sitting on the driver's seat of the vehicle, estimates the driver's head position or ear position, and detects vehicle noise for the vehicle, interior and exterior noise generated inside the vehicle, and overall vehicle noise including the vehicle noise a head position estimating module that generates a vehicle noise signal and a vehicle interior/external noise signal and outputs an echo wave to the estimated head position to cancel out the vehicle interior/external noise; and
A signal processing module that is electrically connected to the head position estimation module and generates an echo signal obtained by processing the vehicle noise signal and the overall vehicle noise signal transmitted from the head position estimation module and transmits the signal to the head position estimation module. Active noise control device for a vehicle, characterized in that to do.
According to claim 1,
A headrest body including a headrest body accommodating the head position estimation module and a pair of fixing bars formed on a lower portion of the headrest body and detachable from an upper portion of the driver's seat seat;
The active noise control device for a vehicle, characterized in that the head position estimation module is an integral type applied to the headrest.
According to claim 2,
The head position estimation module,
A pair of vehicle noise sensors, at least partially exposed to the outside, detecting the vehicle noise generated in the vehicle itself and generating the vehicle noise signal, and at least partially exposed to the outside and detecting the overall vehicle noise to generate the vehicle noise signal A noise sensor unit including a pair of error sensors for generating a total noise signal; including,
The vehicle active noise control device according to claim 1 , wherein the pair of vehicle noise sensors and the pair of error sensors transmit the vehicle noise signal and the overall vehicle noise signal to the signal processing module.
According to claim 3,
The head position estimation module,
a plurality of position sensor units, at least partially exposed to the outside facing the driver's head, generating a plurality of position signals by transmitting and receiving ultrasonic waves or electromagnetic waves toward the driver's head, and arranged in a matrix spaced apart from each other by a predetermined distance; and
and a head position estimator configured to generate head position information obtained by estimating the head position of the driver by comparing intensities of the plurality of position signals transmitted from the plurality of position sensor units. Device.
According to claim 4,
The signal processing module,
The vehicle noise signal transmitted from the pair of vehicle noise sensors and the overall vehicle noise signal transmitted from the pair of error sensors are received and applied to a Least Mean Square (LMS) algorithm to generate a corresponding signal a signal processing unit to do; and
An analog filter unit electrically connected to the signal processing unit and generating the echo signal by filtering the corresponding signal transmitted from the signal processing unit;
The head position estimation module,
a pair of sound output units, at least partially exposed to the outside, outputting the echo waves toward the head of the driver; and
and a controller for controlling the operation of the pair of sound output units according to the echo signal transmitted from the analog filter unit and outputting the echo wave toward the driver's head based on the head position information. Characterized by active noise control device for vehicles.
According to claim 1,
a headrest body including a headrest body accommodating a noise sensor unit and an audio output unit provided in the head position estimation module, and a pair of fixing bars formed on the lower portion of the headrest body and detachable from the upper portion of the driver's seat seat; and
A detachable module accommodating a position sensor unit, a head position estimation unit, and a control unit provided in the head position estimation module and detachable from the pair of fixing bars;
The active noise control device for a vehicle according to claim 1 , wherein the noise sensor unit and the sound output unit are applied to the headrest, and the position sensor unit, the head position estimation unit, and the control unit are of a separate type applied to the detachable module.
According to claim 6,
The noise sensor unit,
a pair of vehicle noise sensors, at least partially exposed to the outside, detecting the vehicle noise generated in the vehicle itself and generating the vehicle noise signal; and
A pair of error sensors, at least partially exposed to the outside, detecting the overall vehicle noise and generating the overall vehicle noise signal;
The vehicle active noise control device according to claim 1 , wherein the pair of vehicle noise sensors and the pair of error sensors transmit the vehicle noise signal and the overall vehicle noise signal to the signal processing module.
According to claim 7,
Wherein the position sensor unit is at least partially exposed to the outside to face the driver's head and generates coordinate information by measuring a position where the headrest main body and the back of the driver's head come into contact.
According to claim 8,
The head position estimator generates ear position information by estimating the position of the driver's ears by applying an inverse kinematics algorithm to the coordinate information transmitted from the position sensor unit.
According to claim 9,
The inverse kinematics algorithm is based on the average distance from the back of the head to the ears based on an adult of a standard body type, the average distance from the shoulder to the seat based on an adult of a standard body type, the average length of the neck based on an adult of a standard body type, and the standard body shape An active noise control device for a vehicle, characterized in that the average length from the neck to the ears of adults is pre-stored and used to estimate the position of the driver's ears.
According to claim 10,
The signal processing unit receives the vehicle noise signal transmitted from the pair of vehicle noise sensors and the total vehicle noise signal transmitted from the pair of error sensors, and applies them to a Least Mean Square (LMS) algorithm. An active noise control device for a vehicle, characterized in that for generating a corresponding signal.
According to claim 11,
The analog filter unit is electrically connected to the signal processing unit and generates the echo signal by filtering the corresponding signal transmitted from the signal processing unit.
According to claim 12,
At least a part of the pair of sound output units is exposed to the outside and outputs the echo waves toward the ears of the driver;
The control unit controls the operation of the pair of sound output units according to the echo signal transmitted from the analog filter unit and outputs the echo wave toward the driver's ears based on the ear position information. Active noise control device for vehicles.

Images