Active noise control device and vehicle

Abstract

An active noise control device and a vehicle. The active noise control device (10) comprises a determination unit (26) and a control unit (28), wherein the determination unit (26) determines whether an acceleration sensor has an abnormality based on a DC component of a reference signal (rx-rz), the reference signal (rx-rz) being obtained by an acceleration sensor (18) installed in a vehicle (12); and the control unit (28) stops generating a control signal (u) based on a reference signal obtained by the acceleration sensor determined to have an abnormality, and stops updating a filter coefficient (W) of an adaptive filter (36) for filtering a reference signal obtained by an acceleration sensor determined not to have an abnormality, when the determination unit determines that any one of the plurality of acceleration sensors has an abnormality. Thus, noise can be reduced well.

Description

Technical Field

[0001] The present invention relates to an active noise control device and a vehicle. Background Art

[0002] An active silencing device is disclosed in Japanese Patent Publication No. 6-59688. The active silencing device disclosed in Japanese Patent Publication No. 6-59688 has a sound generating device, a sound detecting sensor and a vibration sensor. The sound generating device is arranged in the silenced space. The sound detecting sensor is arranged in the silenced space. The vibration sensor is respectively arranged at each vibration source of multiple vibrations propagating to the silenced space. The active silencing device in Japanese Patent Publication No. 6-59688 also has a vibration signal generating mechanism and a driving mechanism. The vibration signal generating mechanism generates a vibration signal with a phase opposite to the sound detected by the sound detecting sensor based on the output signals of the multiple vibration sensors. The driving mechanism drives the sound generating device according to the vibration signal. Summary of the invention

[0003] However, in Japanese Patent Application Laid-Open No. 6-59688, when an abnormality occurs in any one of the plurality of vibration sensors, it is not possible to satisfactorily reduce noise.

[0004] An object of the present invention is to provide an active noise control device and a vehicle that can effectively reduce noise.

[0005] An active noise control device according to one embodiment of the present invention causes an actuator to output a cancelling sound based on a control signal to reduce noise in a vehicle cabin. The active noise control device includes an adaptive filter, a filter coefficient updating unit, a determining unit, and a control unit. The adaptive filter generates the control signal by filtering a reference signal obtained by an acceleration sensor installed in the vehicle. The filter coefficient updating unit updates the filter coefficient of the adaptive filter based on an error signal and the reference signal. The error signal is a signal obtained by detecting residual noise by a microphone, and the residual noise is generated by interference between the noise and the cancelling sound. The determining unit determines whether the acceleration sensor is abnormal based on a DC component of the reference signal. When the determining unit determines that any one of the plurality of acceleration sensors is abnormal, the control unit stops generating the control signal based on the reference signal obtained by the acceleration sensor determined to be abnormal, and stops updating the filter coefficient of the adaptive filter that performs the filtering process on the reference signal obtained by the acceleration sensor determined not to be abnormal.

[0006] A vehicle according to another aspect of the present invention includes the above-described active noise control device.

[0007] According to the present invention, an active noise control device and a vehicle capable of satisfactorily reducing noise can be provided.

[0008] The above-mentioned objects, features and advantages will be easily understood through the following description of the embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a diagram showing an overview of active noise control.

[0010] Figure 2 It is a block diagram showing a part of a vehicle equipped with an active noise control device according to an embodiment.

[0011] Figure 3 It is a diagram showing an example of the configuration of a determination unit.

[0012] Figure 4 It is a diagram showing an example of a coordinate system.

[0013] Figure 5 1 is a flowchart showing an example of the operation of the active noise control device according to one embodiment.

[0014] Figure 6 1 is a flowchart showing an example of the operation of the active noise control device according to one embodiment.

[0015] Figure 7 1 is a flowchart showing an example of the operation of the active noise control device according to one embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, the active noise control device and the vehicle of the present invention will be described in detail with reference to the accompanying drawings and by listing preferred embodiments thereof.

[0017] [One embodiment]

[0018] use Figure 1 to Figure 7 An active noise control device and a vehicle according to an embodiment will be described. Figure 1 It is a diagram showing an overview of active noise control.

[0019] The active noise control device 10 causes the actuator 16 to output a canceling sound for reducing noise (vibration noise) in the cabin 14 of the vehicle 12 .

[0020] The noise in the vehicle cabin 14 may include, for example, road noise, etc. The road noise is caused by the wheels vibrating due to the force from the road surface, and the vibration of the wheels is transmitted to the vehicle body through the suspension and then to the passengers in the vehicle cabin 14 .

[0021] The vehicle 12 has a plurality of vibration sensors for detecting vibrations of the vehicle 12. That is, the vehicle 12 has a plurality of acceleration sensors 18A to 18D. When describing the acceleration sensor as a whole, reference numeral 18 is used. When describing each acceleration sensor, reference numerals 18A to 18D are used. Signals r detected by the acceleration sensors 18A to 18D are provided to the active noise control device 10. That is, signals indicating vibrations are provided to the active noise control device 10.

[0022] A microphone 20 is also provided in the vehicle cabin 14. The microphone 20 detects residual noise (cancellation error noise) generated by interference between the cancelling sound output by the actuator 16 and the noise. The residual noise detected by the microphone 20 is provided to the active noise control device 10. That is, the error signal e detected by the microphone 20 is provided to the active noise control device 10.

[0023] The active noise control device 10 generates a control signal u for causing the actuator 16 to output a cancelling sound based on the signal r detected by the acceleration sensor 18 and the error signal e detected by the microphone 20. More specifically, the active noise control device 10 generates the control signal u that minimizes the error signal e detected by the microphone 20. The actuator 16 outputs the cancelling sound based on the control signal u that minimizes the error signal e detected by the microphone 20, and thus the noise in the vehicle cabin 14 can be well canceled by the cancelling sound. In this way, the active noise control device 10 can reduce the noise transmitted to the occupants in the vehicle cabin 14.

[0024] However, there is a case where any one of the plurality of acceleration sensors 18 has an abnormality. Examples of the abnormality of the acceleration sensor 18 include the detachment of the acceleration sensor 18 and the abnormality of the characteristics of the acceleration sensor 18. For example, the detachment of the acceleration sensor 18 may occur when the portion of the housing on which the acceleration sensor 18 is mounted deteriorates over time. For example, the abnormality of the characteristics of the acceleration sensor 18 may occur when the detection portion of the acceleration sensor 18 deteriorates due to vibration fatigue. When the cancellation sound is generated using only the signal r obtained from the abnormal acceleration sensor 18, the noise in the vehicle cabin 14 may not be canceled well. The inventor of the present application has conceived the following active noise control device 10 as a result of intensive research.

[0025] Figure 2 1 is a block diagram showing a part of a vehicle including the active noise control device according to the present embodiment.

[0026] like Figure 2 As shown, the active noise control device 10 includes a determination unit 26, a control unit 28, a storage unit 30, an output unit 32, filter units 34A to 34D, and a calculation unit 44. When describing the filter unit as a whole, reference numeral 34 is used. When describing each filter unit, reference numerals 34A to 34D are used.

[0027] The active noise control device 10 includes a computing device (computation processing device) not shown in the figure. The computing device can be composed of a processor such as a CPU (Central Processing Unit) and a DSP (Digital Signal Processor), but is not limited to this. The computing device can include a direct digital frequency synthesizer (DDS: Direct Digital Synthesizer), a digitally controlled oscillator (DCO: Digitally Controlled Oscillator), etc. In addition, the computing device can include an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), etc.

[0028] As described above, the active noise control device 10 has a storage unit 30. The storage unit 30 can be composed of a volatile memory (not shown) and a non-volatile memory (not shown). As a volatile memory, for example, a RAM (Random Access Memory) can be cited. As a non-volatile memory, for example, a ROM (Read-Only Memory), a flash memory, etc. can be cited. Data, etc. can be stored in, for example, a volatile memory. Programs, tables, maps, etc. can be stored in, for example, a non-volatile memory.

[0029] The determination unit 26, the control unit 28, the filter unit 34, and the calculation unit 44 can be realized by the calculation device executing a program stored in the storage unit 30. The output unit 32 can be constituted by an output interface circuit or the like.

[0030] The vehicle 12 can include acceleration sensors 18A to 18D. Figure 2 , four acceleration sensors 18 are shown, but the number of acceleration sensors 18 is not limited to four. For example, a three-axis acceleration sensor can be used as the acceleration sensor 18. The three axes are an X-axis, a Y-axis, and a Z-axis. The vibration in the X-axis direction detected by the acceleration sensor 18 is provided to the active noise control device 10 as a reference signal rx. The vibration in the Y-axis direction detected by the acceleration sensor 18 is provided to the active noise control device 10 as a reference signal ry. The vibration in the Z-axis direction detected by the acceleration sensor 18 is provided to the active noise control device 10 as a reference signal rz. When describing the reference signal as a whole, the symbol r is used. When describing each reference signal, the symbols rx, ry, and rz are used.

[0031] As described above, in the carriage 14 (refer to Figure 1 ) has a microphone 20, which is used to detect the residual noise generated by the interference between the noise and the canceling sound. That is, the microphone 20 for detecting the error signal e is provided in the vehicle compartment 14.

[0032] As described above, the carriage 14 (see Figure 1 ) has an actuator 16 that outputs a canceling sound based on a control signal u. As the actuator 16, a speaker can be cited, for example.

[0033] The filter unit 34 includes adaptive filters 36X, 36Y, 36Z, acoustic characteristic filters 38X, 38Y, 38Z, filter coefficient update units 40X, 40Y, 40Z, and a calculation unit 42. When describing the adaptive filter as a whole, the reference numeral 36 is used. When describing each adaptive filter, the reference numeral 36X, 36Y, 36Z is used. When describing the acoustic characteristic filter as a whole, the reference numeral 38 is used. When describing each acoustic characteristic filter, the reference numeral 38X, 38Y, 38Z is used. When describing the filter coefficient update unit as a whole, the reference numeral 40 is used. When describing each filter coefficient update unit, the reference numeral 40X, 40Y, 40Z is used.

[0034] The adaptive filter 36X generates a control signal u0x by filtering the reference signal rx. The adaptive filter 36Y generates a control signal u0y by filtering the reference signal ry. The adaptive filter 36Z generates a control signal u0z by filtering the reference signal rz. When describing the control signal as a whole, the label u0 is used, and when describing each control signal, the labels u0x, u0y, and u0z are used. As the adaptive filter 36, for example, a FIR (Finite Impulse Response) filter or the like can be used, but it is not limited to this. The filter coefficients of the adaptive filters 36X, 36Y, and 36Z are updated by the filter coefficient update units 40X, 40Y, and 40Z as described later. The FIR filter generates the control signal u0 by performing a convolution operation on the reference signal r.

[0035] The acoustic characteristic filter 38X modifies the reference signal rx by performing a filtering process corresponding to the acoustic characteristic (transfer characteristic) from the actuator 16 to the microphone 20 on the reference signal rx. The acoustic characteristic filter 38Y modifies the reference signal ry by performing a filtering process corresponding to the acoustic characteristic from the actuator 16 to the microphone 20 on the reference signal ry. The acoustic characteristic filter 38Z modifies the reference signal rz by performing a filtering process corresponding to the acoustic characteristic from the actuator 16 to the microphone 20 on the reference signal rz. The acoustic characteristic from the actuator 16 to the microphone 20 is acquired in advance. That is, the transfer characteristic C^ from the actuator 16 to the microphone 20 is acquired in advance.

[0036] The filter coefficient updating unit 40X updates the filter coefficient W of the adaptive filter 36X based on the error signal e and the reference signal rx corrected by the acoustic characteristic filter 38X, wherein the error signal e is obtained by detecting the residual noise by the microphone 20. More specifically, the filter coefficient updating unit 40X updates the filter coefficient W of the adaptive filter 36X in a manner that minimizes the error signal e. The filter coefficient updating unit 40Y updates the filter coefficient W of the adaptive filter 36Y based on the error signal e and the reference signal ry corrected by the acoustic characteristic filter 38Y. More specifically, the filter coefficient updating unit 40Y updates the filter coefficient W of the adaptive filter 36Y in a manner that minimizes the error signal e. The filter coefficient updating unit 40Z updates the filter coefficient W of the adaptive filter 36Z based on the error signal e and the reference signal rz corrected by the acoustic characteristic filter 38Z. More specifically, the filter coefficient updating unit 40Z updates the filter coefficient W of the adaptive filter 36Z in a manner that minimizes the error signal e. When updating the filter coefficient W, for example, the Filtered-X LMS algorithm can be used, but the present invention is not limited thereto.

[0037] The filter unit 34 further includes a calculation unit 42. The control signals u0x, u0y, and u0z output from each of the adaptive filters 36X, 36Y, and 36Z are input to the calculation unit 42. The calculation unit 42 adds the control signals u0x, u0y, and u0z provided from each of the adaptive filters 36X, 36Y, and 36Z. The calculation unit (adder) 42 outputs a control signal u0 generated by adding a plurality of control signals u0x, u0y, and u0z.

[0038] The control signal u0 outputted from each filter unit 34A to 34D is inputted to the operation unit 44. The operation unit 44 adds the control signals u0 supplied from each filter unit 34A to 34D. The operation unit (adder) 44 supplies the control signal u generated by adding the plurality of control signals u0 to the actuator 16 via the power amplifier (POWER AMP) 15.

[0039] The determination unit (abnormal determination unit) 26 determines whether an abnormality has occurred in the acceleration sensor 18 based on the DC components of the reference signals rx, ry, and rz. The reason for determining whether an abnormality has occurred in the acceleration sensor 18 based on the DC component of the reference signal r is as follows. That is, since the AC component includes many vibration components that are generated only at the location where the acceleration sensor 18 is installed, it is not easy to determine whether an abnormality has occurred in the acceleration sensor 18 based on the AC component of the reference signal r. On the other hand, since the DC component accurately reflects the movement of the vehicle 12, it is easier to determine whether an abnormality has occurred in the acceleration sensor 18 based on the DC component of the reference signal r. In addition, the gravitational acceleration (acceleration in the vertical direction), which is an important factor, is also a DC component. For such reasons, in the present embodiment, it is determined whether an abnormality has occurred in the acceleration sensor 18 based on the DC component of the reference signal r.

[0040] Figure 3 2 is a diagram showing an example of the structure of the determination unit. Figure 3 As shown, the determination unit 26 includes a first calculation unit 46, a second calculation unit 48, a calculation unit 62, a detection abnormality determination unit 64, and a mounting abnormality determination unit 70. Figure 3 In FIG. 4 , only one first calculation unit 46 is shown, but a first calculation unit 46 is provided for each of the plurality of acceleration sensors 18. Figure 3 In the figure, only one computing unit 62 is shown, but a computing unit 62 is provided for each of the plurality of acceleration sensors 18. Figure 3 In the figure, only one detection abnormality determination unit 64 is shown, but a detection abnormality determination unit 64 is provided for each of the plurality of acceleration sensors 18. Figure 3 Although only one mounting abnormality determination unit 70 is shown in the figure, the mounting abnormality determination unit 70 is provided for each of the plurality of acceleration sensors 18 .

[0041] The first calculation unit 46 includes a DC component extraction unit 50 , a coordinate conversion unit 52 , and a jerk calculation unit 54 .

[0042] As described above, the vibration in the X-axis direction detected by the acceleration sensor 18 is provided to the determination unit 26 as a reference signal rx. The DC component extraction unit 50 can extract the DC component from the reference signal rx and provide the extracted DC component to the coordinate conversion unit 52. As described above, the vibration in the Y-axis direction detected by the acceleration sensor 18 is provided to the determination unit 26 as a reference signal ry. The DC component extraction unit 50 extracts the DC component from the reference signal ry and provides the extracted DC component to the coordinate conversion unit 52. As described above, the vibration in the Z-axis direction detected by the acceleration sensor 18 is provided to the determination unit 26 as a reference signal rz. The DC component extraction unit 50 extracts the DC component from the reference signal rz and provides the extracted DC component to the coordinate conversion unit 52. In this way, the DC component extraction unit 50 can extract the DC component from each reference signal r of the three axes (X axis, Y axis, Z axis) and provide each extracted DC component to the coordinate conversion unit 52.

[0043] The coordinate conversion unit 52 can perform coordinate conversion processing. The X-axis, Y-axis, and Z-axis of the acceleration sensor 18 are not necessarily consistent with the X-axis, Y-axis, and Z-axis of the vehicle 12. Therefore, the coordinate conversion unit 52 performs coordinate conversion processing so that the magnitude of the DC component of each reference signal r of the three axes provided from the DC component extraction unit 50 corresponds to the coordinate system of the vehicle 12.

[0044] The coordinate conversion process can be performed, for example, as follows. Figure 4 It is a diagram showing an example of a coordinate system. Figure 4 The x, y, and z in φ represent the coordinate system of the acceleration sensor 18 . Figure 4 X, Y, and Z in FIG. 1 represent a coordinate system in the vehicle 12 .

[0045] The DC components of the reference signals rx, ry, and rz provided by the acceleration sensor 18 are set to asx, asy, and asz, respectively. That is, the acceleration in the coordinate system of the acceleration sensor 18 is set to asx, asy, and asz. asx is the acceleration of the acceleration sensor 18 in the X-axis direction. asy is the acceleration of the acceleration sensor 18 in the Y-axis direction. asz is the acceleration of the acceleration sensor 18 in the Z-axis direction. The DC components of the reference signals rx, ry, and rz when transformed into the coordinate system of the vehicle 12 are set to avx, avy, and avz. That is, the acceleration in the coordinate system of the vehicle 12 is set to avx, avy, and avz. avx is the acceleration of the vehicle 12 in the X-axis direction. avy is the acceleration of the vehicle 12 in the Y-axis direction. avz is the acceleration of the vehicle 12 in the Z-axis direction. When the accelerations asx, asy, asz in the coordinate system of the acceleration sensor 18 are converted into accelerations avx, avy, avz in the coordinate system of the vehicle 12, the following matrix operation can be performed. Av represents the acceleration in the coordinate system of the vehicle 12. As represents the acceleration in the coordinate system of the acceleration sensor 18. Rsv represents the coordinate conversion matrix.

[0046] A v =R sv A s

[0047]

[0048] The coordinate transformation matrix Rsv can be expressed as follows: Rx is a matrix for performing X-axis rotation. Ry is a matrix for performing Y-axis rotation. Rz is a matrix for performing Z-axis rotation.

[0049] R sv =R z R y R x

[0050]

[0051]

[0052]

[0053] In this way, the accelerations avx, avy, and avz corresponding to the coordinate system of the vehicle 12 are calculated by the coordinate conversion unit 52. The coordinate conversion unit 52 supplies a signal indicating the acceleration corresponding to the traveling direction of the vehicle 12 to the jerk calculation unit 54. Here, the case where the X-axis direction in the coordinate system of the vehicle 12 is the traveling direction of the vehicle 12 is described as an example. The coordinate conversion unit 52 supplies a signal indicating the acceleration avx in the traveling direction of the vehicle 12 to the jerk calculation unit 54.

[0054] The coordinate conversion unit 52 supplies a signal indicating the acceleration in the up-down direction of the vehicle 12 to the installation abnormality determination unit 70. That is, the coordinate conversion unit 52 supplies a signal indicating the acceleration in the vertical direction to the installation abnormality determination unit 70. The vertical direction component in the DC component of the reference signal r is supplied to the installation abnormality determination unit 70. Here, the case where the Z-axis direction in the coordinate system of the vehicle 12 is the up-down direction of the vehicle 12 is described as an example. The coordinate conversion unit 52 supplies a signal indicating the acceleration avz in the up-down direction of the vehicle 12 to the installation abnormality determination unit 70.

[0055] The jerk calculation unit 54 calculates the jerk jvx in the traveling direction of the vehicle 12 based on the signal provided from the coordinate conversion unit 52. That is, the jerk calculation unit 54 calculates the jerk jvx in the traveling direction of the vehicle 12 based on the acceleration avx in the traveling direction of the vehicle 12. Such jerk jvx can be obtained by calculating the change in acceleration per unit time.

[0056] The acceleration obtained last time is denoted as avxb. The acceleration obtained this time is denoted as avxn. The time from the time when the acceleration avxb last time is obtained to the time when the acceleration avxn this time is obtained is denoted as Δt1. The jerk jvx is obtained by the following equation (1).

[0057] jvx=(avxn-avxb) / Δt1…(1)

[0058] Thus, the first calculation unit 46 can calculate the jerk jvx in the traveling direction of the vehicle 12 based on the signal acquired by the acceleration sensor 18. More specifically, the first calculation unit 46 can calculate the jerk jvx in the traveling direction of the vehicle 12 based on the DC component of the reference signal r.

[0059] The second calculation unit 48 includes a velocity signal acquisition unit 56 , an acceleration calculation unit 58 , and a jerk calculation unit 60 .

[0060] The speed signal acquisition unit 56 acquires a signal provided from the speed sensor 19 provided in the vehicle 12. That is, the speed signal acquisition unit 56 acquires a signal indicating the speed v.

[0061] The acceleration calculation unit 58 calculates the acceleration a of the vehicle 12 based on the signal acquired by the speed signal acquisition unit 56. That is, the acceleration calculation unit 58 calculates the acceleration in the traveling direction of the vehicle 12 based on the signal indicating the speed v. The acceleration a can be obtained by calculating the speed change per unit time.

[0062] The speed acquired last by the speed signal acquisition unit 56 is vb. The speed acquired this time by the speed signal acquisition unit 56 is vn. The time from the time when the last speed vb is acquired to the time when the current speed vn is acquired is Δt2. Then, the acceleration a is obtained by the following equation (2).

[0063] a=(vn-vb) / Δt2…(2)

[0064] The jerk calculation unit 60 calculates the jerk j of the vehicle 12 based on the acceleration a calculated by the acceleration calculation unit 58. That is, the jerk calculation unit 60 calculates the jerk in the traveling direction of the vehicle 12 based on the acceleration a calculated by the acceleration calculation unit 58. The jerk j can be obtained by calculating the change in acceleration per unit time.

[0065] The acceleration calculated last time by the acceleration calculation unit 58 is defined as ab. The acceleration calculated this time by the acceleration calculation unit 58 is defined as an. The time from when the last acceleration ab is acquired to when the current acceleration an is acquired is defined as Δt3. Then, the jerk j is obtained by the following equation (3).

[0066] j=(an-ab) / Δt3…(3)

[0067] In this way, the second calculation unit 48 calculates the jerk j in the traveling direction of the vehicle 12 based on the signal acquired by the speed sensor 19 included in the vehicle 12 .

[0068] The calculation unit 62 calculates a difference Δj between the jerk jvx calculated by the first calculation unit 46 and the jerk j calculated by the second calculation unit 48. The difference Δj is expressed by the following equation (4).

[0069] Δj=|jvx-j|…(4)

[0070] When the difference Δj between the jerk jvx calculated by the first calculation unit 46 and the jerk j calculated by the second calculation unit 48 is greater than the difference threshold DTH, the detection abnormality determination unit 64 determines that the acceleration sensor 18 is abnormal (detection abnormality). More specifically, when the difference Δj is greater than the difference threshold DTH and the state of the difference Δj being greater than the difference threshold DTH continues for a time threshold TTH or longer, the detection abnormality determination unit 64 determines that the acceleration sensor 18 is abnormal (detection abnormality). In the present embodiment, the reason why the acceleration sensor 18 is determined to be abnormal is not based on the acceleration but on the jerk is as follows. That is, when the vehicle 12 has an acceleration sensor 18 with relatively low acceleration detection accuracy, it is not easy to determine whether the acceleration sensor 18 is abnormal based on the acceleration detected by the acceleration sensor 18. In contrast, when determining whether the acceleration sensor 18 is abnormal based on the jerk, it is possible to determine whether the acceleration sensor 18 is abnormal well even if the detection accuracy of the acceleration sensor 18 is relatively low. For such reasons, in the present embodiment, whether or not an abnormality has occurred in the acceleration sensor 18 is determined based on the jerk rather than the acceleration. The determination result of the detection abnormality determination unit 64 is provided to the control unit 28 .

[0071] As described above, the vertical direction component in the DC component of the reference signal r is provided to the installation abnormality determination unit 70. The positive and negative signs of the values ​​of the vertical direction component in the DC component of the reference signal r are different when the acceleration sensor 18 is normally installed on the vehicle 12 and when the acceleration sensor 18 is not normally installed on the vehicle 12. Here, the case where the vertical direction component in the DC component of the reference signal r is negative is normal, and the case where the vertical direction component in the DC component of the reference signal r is positive is abnormal is described as an example.

[0072] If an abnormal mounting occurs, that is, the front and back sides of the acceleration sensor 18 are mounted upside down, a sound having the same phase as the noise is output from the actuator 16 as a canceling sound, which is likely to increase the noise.

[0073] The installation abnormality determination unit 70 determines whether an abnormality (installation abnormality) has occurred in the acceleration sensor 18 based on the positive and negative signs of the vertical direction component in the DC component of the reference signal r. When the vertical direction component in the DC component of the reference signal r is negative, the installation abnormality determination unit 70 determines that no abnormality (installation abnormality) has occurred in the acceleration sensor 18. On the other hand, when the vertical direction component in the DC component of the reference signal r is positive, the installation abnormality determination unit 70 determines that an abnormality (installation abnormality) has occurred in the acceleration sensor 18.

[0074] In addition, in the above, the case where the vertical direction component in the DC component of the reference signal r is negative is normal, and the case where the vertical direction component in the DC component of the reference signal r is positive is abnormal is described as an example, but it is not limited to this. It can also be that the case where the vertical direction component in the DC component of the reference signal r is positive is normal, and the case where the vertical direction component in the DC component of the reference signal r is negative is abnormal. In this case, when the vertical direction component in the DC component of the reference signal r is positive, the installation abnormality determination unit 70 determines that the acceleration sensor 18 has no installation abnormality. On the other hand, when the vertical direction component in the DC component of the reference signal r is negative, the installation abnormality determination unit 70 determines that the acceleration sensor 18 has an installation abnormality.

[0075] When the determination unit 26 determines that any one of the plurality of acceleration sensors 18 has an abnormality, the control unit 28 stops generating the control signal u0 based on the reference signal r obtained by the acceleration sensor 18 determined to have an abnormality. The reason for stopping generating the control signal u0 based on the reference signal r obtained by the acceleration sensor 18 determined to have an abnormality is as follows. That is, when the actuator 16 is driven using the control signal u0 obtained based on the reference signal r obtained by the acceleration sensor 18 determined to have an abnormality, the actuator 16 is driven using an inappropriate control signal u0. When the actuator 16 is driven using an inappropriate control signal u0, noise cannot be reduced well. For such reasons, in the present embodiment, generating the control signal u0 based on the reference signal r obtained by the acceleration sensor 18 determined to have an abnormality is stopped.

[0076] When the determination unit 26 determines that any one of the plurality of acceleration sensors 18 has an abnormality, the control unit 28 further performs the following control. That is, in this case, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r obtained by the acceleration sensor 18 determined not to have an abnormality. The reason for stopping updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r obtained by the acceleration sensor 18 determined not to have an abnormality is as follows. That is, in the active noise control device 10 that performs control using the signals r detected by the plurality of acceleration sensors 18, the parameters are adjusted so that each seat 13 can obtain the noise reduction effect in a balanced manner. Therefore, in the case where the signal r obtained by any one of the acceleration sensors 18 is missing, the above balance is destroyed, and the phenomenon occurs that the noise of a certain seat 13 is sufficiently reduced, while the noise of other seats 13 increases. For this reason, in this case, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r obtained by the acceleration sensor 18 determined not to have an abnormality.

[0077] When it is determined that the acceleration sensor 18 has an abnormality, the control unit 28 stores information indicating that the acceleration sensor 18 has an abnormality in the storage unit 30. The information indicating that the acceleration sensor 18 has an abnormality can be used, for example, in fault diagnosis.

[0078] The output unit 32 is used to notify the fault diagnosis device 66 of information indicating that an abnormality has occurred in the acceleration sensor 18. When the fault diagnosis device 66 is connected to the vehicle 12, the control unit 28 provides the information indicating that an abnormality has occurred in the acceleration sensor 18 to the fault diagnosis device 66 via the output unit 32. Since the information indicating that an abnormality has occurred in the acceleration sensor 18 is provided to the fault diagnosis device 66, the fault diagnosis device 66 can accurately perform fault diagnosis.

[0079] When it is determined that the acceleration sensor 18 has an abnormality, the control unit 28 outputs information indicating that the acceleration sensor 18 has an abnormality to the information display 68 provided in the vehicle 12. The information display 68 can display information indicating that the acceleration sensor 18 has an abnormality. Since the information indicating that the acceleration sensor 18 has an abnormality can be displayed on the information display 68, the user can understand that the acceleration sensor 18 has an abnormality based on the display of the information display 68.

[0080] Next, use Figure 5 An example of the operation of the active noise control device according to the present embodiment will be described. Figure 5 : is a flowchart showing an example of the operation of the active noise control device according to the present embodiment.

[0081] First, in step S1, the determination unit 26 determines whether an abnormality has occurred in the acceleration sensor 18A. If an abnormality has occurred in the acceleration sensor 18A (Yes in step S1), the process proceeds to step S5. If an abnormality has not occurred in the acceleration sensor 18A (No in step S1), the process proceeds to step S2.

[0082] In step S2, the determination unit 26 determines whether an abnormality has occurred in the acceleration sensor 18B. If an abnormality has occurred in the acceleration sensor 18B (Yes in step S2), the process proceeds to step S6. If an abnormality has not occurred in the acceleration sensor 18B (No in step S2), the process proceeds to step S3.

[0083] In step S3, the determination unit 26 determines whether an abnormality has occurred in the acceleration sensor 18C. If an abnormality has occurred in the acceleration sensor 18C (Yes in step S3), the process proceeds to step S7. If an abnormality has not occurred in the acceleration sensor 18C (No in step S3), the process proceeds to step S4.

[0084] In step S4, the determination unit 26 determines whether an abnormality has occurred in the acceleration sensor 18D. If an abnormality has occurred in the acceleration sensor 18D (Yes in step S4), the process proceeds to step S8. If an abnormality has not occurred in the acceleration sensor 18D (No in step S4), Figure 5 The indicated processing is completed.

[0085] In step S5, the control unit 28 stops generating the control signal u0 based on the reference signal r acquired by the acceleration sensor 18A, and then moves to step S9.

[0086] In step S6 , the control unit 28 stops generating the control signal u0 based on the reference signal r acquired by the acceleration sensor 18B, and then moves to step S10 .

[0087] In step S7 , the control unit 28 stops generating the control signal u0 based on the reference signal r acquired by the acceleration sensor 18C, and then moves to step S11 .

[0088] In step S8, the control unit 28 stops generating the control signal u0 based on the reference signal r acquired by the acceleration sensor 18D. Thereafter, the process moves to step S12.

[0089] In step S9, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r acquired by the acceleration sensors 18B to 18D. That is, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 included in the filter units 34B to 34D. When step S9 is completed, Figure 5 The indicated processing is completed.

[0090] In step S10, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r acquired by the acceleration sensors 18A, 18C, and 18D. That is, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 included in the filter units 34A, 34C, and 34D. When step S10 is completed, Figure 5 The indicated processing is completed.

[0091] In step S11, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r acquired by the acceleration sensors 18A, 18B, and 18D. That is, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 included in the filter units 34A, 34B, and 34D. When step S11 is completed, Figure 5 The indicated processing is completed.

[0092] In step S12, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r acquired by the acceleration sensors 18A to 18C. That is, the control unit 28 stops updating the filter coefficient W of the adaptive filter 36 included in the filter units 34A to 34C. When step S12 is completed, Figure 5 The indicated processing is completed.

[0093] Next, use Figure 6 An example of the operation of the active noise control device according to the present embodiment will be described. Figure 6 : is a flowchart showing an example of the operation of the active noise control device according to the present embodiment.

[0094] In step S21 , the first calculation unit 46 calculates the jerk jvx in the traveling direction of the vehicle 12 based on the DC component of the reference signal r.

[0095] In step S22, the second calculation unit 48 calculates the jerk j in the traveling direction of the vehicle 12 based on the signal acquired by the speed sensor 19 of the vehicle 12. That is, the second calculation unit 48 calculates the jerk j in the traveling direction of the vehicle 12 based on the signal indicating the speed v.

[0096] In step S23, the determination unit 26 determines whether the difference Δj between the jerk jvx calculated by the first calculation unit 46 and the jerk j calculated by the second calculation unit 48 is greater than the difference threshold DTH. When the difference Δj is greater than the difference threshold DTH (yes in step S23), the process moves to step S24. When the difference Δj is less than the difference threshold DTH (no in step S23), the process moves to step S25.

[0097] In step S24 , the determination unit 26 determines that an abnormality has occurred in the acceleration sensor 18 .

[0098] In step S25, the determination unit 26 determines that no abnormality has occurred in the acceleration sensor 18. Figure 6 The indicated processing is completed.

[0099] Next, use Figure 7 An example of the operation of the active noise control device according to the present embodiment will be described. Figure 7 1 is a flowchart showing an example of the operation of the active noise control device of this embodiment. Here, the case where the vertical component of the DC component of the reference signal r is negative is normal, and the case where the vertical component of the DC component of the reference signal r is positive is abnormal is described as an example.

[0100] In step S31, the determination unit 26 determines whether the value of the vertical direction component in the DC component of the reference signal r is negative. When the value of the vertical direction component in the DC component of the reference signal r is negative (yes in step S31), the process moves to step S32. When the value of the vertical direction component in the DC component of the reference signal r is positive (no in step S31), the process moves to step S33.

[0101] In step S32 , the determination unit 26 determines that no abnormality has occurred in the acceleration sensor 18 .

[0102] In step S33, the determination unit 26 determines that an abnormality has occurred in the acceleration sensor 18. Figure 7 The indicated processing is completed.

[0103] As described above, in the present embodiment, when the determination unit 26 determines that any one of the plurality of acceleration sensors 18 has an abnormality, generation of the control signal u0 based on the reference signal r acquired by the acceleration sensor 18 determined to have an abnormality is stopped. In addition, in the present embodiment, updating of the filter coefficient W of the adaptive filter 36 that performs filtering processing on the reference signal r acquired by the acceleration sensor 18 determined not to have an abnormality is stopped. Therefore, according to the present embodiment, it is possible to provide an active noise control device 10 that can suppress adverse effects caused by the acceleration sensor 18 that has an abnormality even when any one of the plurality of acceleration sensors 18 has an abnormality, thereby effectively reducing noise.

[0104] As mentioned above, although the preferred embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the present invention.

[0105] The above-mentioned embodiments can be summarized as follows.

[0106] An active noise control device (10) causes an actuator (16) to output a cancelling sound based on a control signal (u) to reduce noise in a vehicle compartment (14) of a vehicle (12). The active noise control device (10) comprises an adaptive filter (36X-36Z), a filter coefficient updating unit (40X-40Z), a determination unit (26) and a control unit (28), wherein the adaptive filter (36X-36Z) generates the control signal by filtering a reference signal (rx-rz) obtained by an acceleration sensor (18A-18D) installed in the vehicle; and the filter coefficient updating unit (40X-40Z) updates the filter coefficient (W) of the adaptive filter according to an error signal (e) and the reference signal. , wherein the error signal (e) is a signal obtained by detecting residual noise by a microphone (20), the residual noise being generated by interference between the noise and the canceling sound; the determination unit (26) determines whether the acceleration sensor is abnormal based on the DC component of the reference signal; when the determination unit determines that any one of the plurality of acceleration sensors is abnormal, the control unit (28) stops generating the control signal based on the reference signal obtained by the acceleration sensor determined to be abnormal, and stops updating the filter coefficient of the adaptive filter that performs the filtering process on the reference signal obtained by the acceleration sensor determined not to be abnormal. According to such a structure, an active noise control device can be provided, which can suppress the adverse effects of the abnormal acceleration sensor even when any one of the plurality of acceleration sensors is abnormal, thereby effectively reducing noise.

[0107] The vehicle may further include a first calculation unit (46) and a second calculation unit (48), wherein the first calculation unit (46) calculates the jerk (jvx) in the direction of travel of the vehicle based on the DC component of the reference signal, and the second calculation unit (48) calculates the jerk (j) in the direction of travel of the vehicle based on a signal (v) obtained by a speed sensor (19) provided on the vehicle, and when the difference (Δj) between the jerk calculated by the first calculation unit and the jerk calculated by the second calculation unit is greater than a difference threshold (DTH), the determination unit determines that an abnormality has occurred in the acceleration sensor. According to such a structure, since the determination is made using the jerk, even when an acceleration sensor having a low acceleration detection accuracy is provided in the vehicle, it is possible to well determine whether the acceleration sensor has an abnormality.

[0108] When the acceleration sensor is normally mounted on the vehicle and when the acceleration sensor is not normally mounted on the vehicle, the sign of the vertical direction component in the DC component of the reference signal is different, and the determination unit can determine whether the acceleration sensor is abnormal based on the sign of the vertical direction component. According to such a structure, even when an abnormality occurs such as the front side and the back side of the acceleration sensor are mounted upside down (installation abnormality), the abnormality can be accurately determined.

[0109] When it is determined that the acceleration sensor is abnormal, the control unit may store information indicating that the acceleration sensor is abnormal in the storage unit (30). According to such a structure, the information indicating that the acceleration sensor is abnormal can be used in fault diagnosis and the like.

[0110] The device may also include an output unit (32) for notifying the fault diagnosis device (66) of information indicating that the acceleration sensor is abnormal. According to such a structure, since the information indicating that the acceleration sensor is abnormal can be provided to the fault diagnosis device, the fault diagnosis device can perform accurate fault diagnosis.

[0111] When it is determined that the acceleration sensor is abnormal, the control unit may also output information indicating that the acceleration sensor is abnormal to an information display (68) provided on the vehicle. According to such a structure, since the information indicating that the acceleration sensor is abnormal can be displayed on the information display, the user can understand that the acceleration sensor is abnormal based on the display on the information display.

[0112] The acceleration sensor may be a three-axis acceleration sensor.

[0113] The vehicle includes the active noise control device as described above.

Claims

1. An active noise control device (10) which causes an actuator (16) to output a cancelling sound based on a control signal (u) to reduce noise in a cabin (14) of a vehicle (12), characterized in that: The invention comprises an adaptive filter (36X-36Z), a filter coefficient updating unit (40X-40Z), a determination unit (26) and a control unit (28), wherein: The adaptive filter (36X-36Z) generates the control signal by filtering the reference signal (rx-rz) obtained by the acceleration sensor (18A-18D) installed on the vehicle; The filter coefficient updating unit (40X-40Z) updates the filter coefficient (W) of the adaptive filter according to the error signal (e) and the reference signal, wherein the error signal (e) refers to a signal obtained by detecting residual noise generated by interference between the noise and the canceling sound by a microphone (20); The determination unit (26) determines whether an abnormality occurs in the acceleration sensor based on the DC component of the reference signal; When the determination unit determines that an abnormality has occurred in any one of the multiple acceleration sensors, the control unit (28) stops generating the control signal based on the reference signal obtained by the acceleration sensor determined to have an abnormality, and stops updating the filter coefficients of the adaptive filter that performs the filtering process on the reference signal obtained by the acceleration sensor determined to have no abnormality.

2. The active noise control device according to claim 1, characterized in that: It also has a first calculation unit (46) and a second calculation unit (48), wherein: The first calculation unit (46) calculates the jerk (jvx) in the traveling direction of the vehicle based on the DC component of the reference signal. The second calculation unit (48) calculates the jerk (j) of the vehicle in the traveling direction based on a signal (v) acquired by a speed sensor (19) provided on the vehicle. The determination unit determines that an abnormality has occurred in the acceleration sensor when a difference (Δj) between the jerk calculated by the first calculation unit and the jerk calculated by the second calculation unit is equal to or larger than a difference threshold value (DTH).

3. The active noise control device according to claim 1, characterized in that: When the acceleration sensor is normally mounted on the vehicle and when the acceleration sensor is not normally mounted on the vehicle, the sign of the vertical direction component of the DC component of the reference signal is different. The determination unit determines whether an abnormality has occurred in the acceleration sensor based on the positive or negative sign of the vertical direction component.

4. The active noise control device according to claim 1, characterized in that: When it is determined that the acceleration sensor has an abnormality, the control unit stores information indicating that the acceleration sensor has an abnormality in a storage unit (30).

5. The active noise control device according to claim 1, characterized in that: An output unit (32) is also provided, and the output unit (32) is used to notify the fault diagnosis device (66) of information indicating that an abnormality has occurred in the acceleration sensor.

6. The active noise control device according to claim 1, characterized in that: When it is determined that the acceleration sensor has an abnormality, the control unit outputs information indicating that the acceleration sensor has an abnormality to an information display (68) provided on the vehicle.

7. The active noise control device according to claim 1, characterized in that: The acceleration sensor is a three-axis acceleration sensor.

8. A vehicle, characterized in that: An active noise control device according to any one of claims 1 to 7.

Images