JP4940792B2 - Noise control device and noise control method - Google Patents

Description

  The present invention relates to a noise control device and a noise control method.

  In general, there has been proposed a noise control device and a noise control method for measuring noise generated as a vehicle travels in a vehicle interior and the like, and generating sound waves that cancel the noise to reduce noise. For example, a plurality of vibration detection means for detecting the vibration of the vehicle body of the vehicle are provided, and an actuator such as a speaker or a vibrator installed in the vehicle is operated based on the detected vibration of the vehicle body to reduce the noise in the vehicle interior. Noise control devices have been proposed.

In such a noise control device, it becomes difficult to perform effective noise control when a failure occurs in the vibration detection means. Therefore, if a microphone for effect confirmation that measures the noise reduction effect is installed in a place where noise control is performed and the vibration detection means fails and the noise reduction effect is not sufficient, the noise control control There has been proposed a noise control device that performs effective noise control by changing the contents (see Patent Document 1).
Japanese Patent Laid-Open No. 8-2922771

  In such a noise control device, when a failure occurs in the actuator, it becomes impossible to generate an appropriate wave for reducing the noise and it becomes difficult to effectively perform the noise control. Depending on the situation, an inappropriate wave may be generated from the actuator, which may increase noise. However, since there is no means for detecting the failure of the actuator, there is a problem that it is difficult to take measures such as stopping noise control when the actuator fails.

In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a plurality of sensors arranged on a vehicle body for detecting vibrations of the vehicle body, and a wave wave for applying a wave controlled by a control unit to the vehicle body. The application unit and the control unit provide the wave application unit with the predetermined wave transmission function so that a gain of the wave transfer function between the wave application unit and a predetermined space in the vehicle interior of the vehicle is equal to or less than a predetermined value. When a signal having a predetermined frequency set for each space is output, a wave application unit failure detection unit that detects a failure of the wave application unit based on the output signal of the sensor, and each output signal of the plurality of sensors A noise estimation unit that calculates an estimated value of vehicle interior noise that can be heard in the predetermined space, and the control unit detects the noise when the wave application unit failure detection unit does not detect a failure of the wave application unit. Calculated by the estimator Based on the estimated value of the serial-compartment noise the output wave to the wave applying unit is characterized by performing the noise control for reducing the vehicle interior noise.

  The present invention provides a noise control device and a noise control method that perform noise control only when an actuator failure is not detected, assuming that a noise control effect cannot be obtained when an actuator failure is detected.

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

  Typical causes of vehicle interior noise entering from outside the vehicle are engine noise caused by engine vibration, noise caused by road surface unevenness entering from tires during driving (hereinafter referred to as road noise). ), Wind noise generated by the airflow during driving.

  In this embodiment, reduction of road noise is mainly handled.

  FIG. 1 shows main propagation paths of vehicle body vibration and road noise caused by road surface unevenness.

  The vibration that becomes the main component of the road noise that has entered the vehicle body from the tire 200 first enters a highly rigid beam-like member called the member 140 from the mounting portion (not shown) of the axle 120 and the suspension 130. Thereafter, vibration propagates to a plate-like member called floor panel 110 surrounded by the member 140 and having relatively low rigidity, and the floor panel 110 vibrates. Furthermore, the vibration of the floor panel 110 causes air vibrations in the vehicle interior and causes a resonance phenomenon in the vehicle interior, so that road noise is heard in a predetermined space 100 (hereinafter referred to as a control space 100) in the vehicle interior. Although noise is also generated when the roof panel and window glass (both not shown) vibrate in addition to the floor panel 110, most of the road noise that enters mainly from the attachment portion of the suspension 130 is generated by the floor panel 110. It is known to be caused by vibration. For this reason, if noise control is performed so as to cancel road noise caused by vibration of the floor panel 110, road noise can be reduced.

  In the present invention, a sensor (described later) is arranged on the floor panel 110, vehicle interior noise is estimated based on the output signal of the sensor, a control command value is generated by the controller, and the floor is based on the control command value. A method is adopted in which control sound generated by an actuator (wave application unit) provided on panel 110 is input into the passenger compartment.

  Here, the present invention uses a method of estimating the noise of the control space 100 from the signal of the acceleration sensor 10 without using a microphone as a sensor. Since the acceleration sensor 10 installed on the floor panel 110 is used, road noise caused by the floor panel 110 is handled as a control target. Here, the reason why the floor panel 110 is selected as the installation location of the acceleration sensor 10 is that coherence with the vehicle interior noise (definition will be described later) is high.

  In addition, since all the noises generated from the floor panel 110 are included in the control target, it is possible to handle a part of the engine noise and the wind noise generated by the air flowing through the bottom of the vehicle body.

  Further, the scope of the effect of the present invention is not limited to the category of noise reduction due to vibration of the floor panel 110. For example, vehicle interior noise generated by the same mechanism such as a dash panel, a front glass, and a roof panel (both not shown). The same effect can be obtained for the generation source if the present invention is used for the site.

  A schematic diagram of the noise control apparatus according to the present embodiment is shown in FIG.

  The noise control device according to the present embodiment includes an acceleration sensor 10 (10a, 10b, 10c, 10d) that is a sensor that measures vibration of the floor panel 110, and an actuator 20 (20a) that is a wave application unit that applies vibration to the floor panel 110. 20b) and a control device body 30 for controlling the actuator 20 by calculating a control command value for reducing vehicle interior noise based on the signal obtained by the acceleration sensor 10.

  Here, the actuator 20 in the present embodiment is a so-called piezo-electric actuator.

  An input signal of the control device main body 30 is an output of the acceleration sensor 10, and an output signal is a control command value to the actuator 20.

  The control device body 30 includes an amplification unit 31 (31a to 31f) for signal amplification and a control command value calculation unit 32 that calculates and outputs a control command value for reducing vehicle interior noise.

  When the acceleration sensor 10 is a so-called charge charge type, the amplifying unit 31 also has a function of converting between charge and voltage.

  FIG. 3 is a block diagram showing the internal structure of the control command value calculation unit 32.

  The control command value calculation unit 32 includes an A / D conversion unit 33 (33a to 33f), a drive unit failure detection unit 34 that is a wave application unit failure detection unit, an addition unit 36, a filter 50, and a transfer function 60. The control unit 37 includes a noise estimation unit 35, a calculation unit 38, a D / A conversion unit 39, and a test signal generation unit 40.

The A / D conversion unit 33 (33a to 33f) includes acceleration signals α ₁ , α ₂ , α ₃ , and α ₄ detected by the acceleration sensor 10 and amplified by the amplification unit 31 (31a to 31d), and a control unit 37. The output control command values u ₁ and u ₂ are converted into digital signals.

  The D / A converter 39 converts the control command value calculated by the calculator 38 and the test signal generated by the test signal generator 40 into an analog signal.

  The control command value calculation unit 32 calculates a control command value so as to reduce noise in the control space 100 using the acceleration signal output from the acceleration sensor 10 and the input signal (control command value) to the actuator 20. .

  A sufficient number of actuators 20 are attached to appropriate positions on the floor panel 110 of the vehicle body in order to reduce noise in the control space 100.

Generally, the number of acceleration sensors 10 needs to be larger than the number of vibration sources. The specific number and installation positions of the acceleration sensors 10 are determined by coherency C _xy (ω) between each acceleration sensor 10 and the sound pressure of noise in the control space 100.

Is determined to be sufficiently high (for example, 0.9 or more). In this embodiment, the acceleration sensor 10 includes an acceleration sensor 10a (described as sensor 1 in FIG. 3), an acceleration sensor 10b (described as sensor 2 in FIG. 3), an acceleration sensor 10c (described as sensor 3 in FIG. 3), an acceleration. There are four sensors 10d (denoted as sensor 4 in FIG. 3), and two actuators 20 are actuator 20a (denoted as ACTR1 in FIG. 3) and actuator 20b (denoted as ACTR2 in FIG. 3).

Here, P _xy (ω) represents a cross power spectrum between acceleration and sound pressure, and P _xx (ω) and P _yy (ω) represent auto power spectra of acceleration and sound pressure, respectively. P ^H represents a Hermitian transpose matrix of P.

The noise estimation unit 35 calculates an estimated noise value SPL_est in the control space 100 using the acceleration signals α _{1 to} α ₄ and the control command values u ₁ and u ₂ in the processing cycle one step before.

The calculation unit 38 of the control unit 37 uses the estimated noise value SPL_est to calculate control command values u ₁ and u ₂ for the actuator 20 so as to reduce noise in the control space 100.

  In this embodiment, this control command value calculation unit 32 is mounted on a so-called CPU.

  A flowchart of processing in the control device main body 30 is shown in FIG.

In step S <b> 101, acceleration signals α _{1 to} α ₄ A / D converted by the A / D conversion unit 33 are input to the noise estimation unit 35 through the drive unit failure detection unit 34. After this, the flow moves to step S102.

In step S < _b > 102, control command values u ₁ and u ₂ one step before A / D conversion by the A / D conversion unit 33 are input to the noise estimation unit 35. After this, the flow moves to step S103.

  In step S103, noise estimation processing is executed by the noise estimation unit 35, and an estimated value SPL_est of the noise in the control space 100 is calculated from the signals obtained in S101 and S102. After this, the flow moves to step S104.

In step S104, the control command values u ₁ and u ₂ for reducing noise in the control space 100 are calculated by the calculation unit 38 using the estimated noise value SPL_est calculated in S103. After this, the flow moves to step S105.

In step S105, the control command values u ₁ and u ₂ obtained in S104 are output to the D / A converter 39, and an output signal to the actuator 20 is output.

  The calculation unit 38 in FIG. 3 may be designed using any feedback control. For example, when designing as H∞ control, the following procedure may be followed.

The system model is a transfer function G _p (s) from the input voltage of the actuator 20 to the noise. Here, s is a variable of Laplace transform.

For this transfer function G _p (s), the literature “D. McFarlane and K. Glover.“ A Loop Shaping Design Procedure Using H∞ Synthesis ”, IEEE Transactions on Automatic Control. Vol.37, no.6, June 1992 , Pp.759-769 ”, a control unit that reduces noise can be designed.

  In this method, the evaluation formula

Design a controller C _∞ (s) that satisfies Where G _s (s) is the transfer function weighted by weight functions W ₁ (s) and W ₂ (s)

Sought by. Finally, using controller C _∞ (s) that satisfies the evaluation formula of (Formula 2), controller C (s) is

Is calculated as

  The constant ε is a parameter for determining the stability margin of the controller, and 0.2 to 0.3 is usually recommended. When mounted on the CPU, for example, C (s) may be discretized by performing bilinear transformation on the controller C (s) and mounted as an IIR filter.

Acceleration signals α ₁ , α ₂ , α ₃ and α ₄ as digital signals input to the noise estimation unit 35 are input to 50a, 50b, 50c and 50d of the filter 50, respectively. Further, the control command values u ₁ and u ₂ are respectively input to 60a and 60b of the transfer function 60.

Here, the filters 50 a to 50 d are blocks that shape the acceleration signals α _{1 to} α ₄ in order to express noise entering the control space 100 from the outside of the vehicle as a sum of certain signals. This filter 50 is designed so that the sum of the processed signals becomes an estimated value of noise entering from outside the vehicle.

  Transfer functions 60a and 60b represent transfer functions from the input voltage to the actuators 20a and 20b to the sound pressure in the control space 100, respectively. The transfer functions 60a and 60b can be obtained by inputting white noise or an impulse signal to the actuator 20 and performing system identification using the sound pressure signal and the input signal in the control space 100 obtained at that time. The method includes, for example, “Structural Dynamical Toolbox” which is a tool box of the control system design tool MATLAB, and subspace identification described in the literature “Adachi,“ System Identification for Control ”, Tokyo Denki University Press, 1996”. The method may be used.

  By multiplying the input voltages of the actuators 20a and 20b by the transfer functions 60a and 60b, respectively, and adding them together, an estimated value of noise generated in the control space 100 by vibration (sound) generated by the actuator 20 is calculated.

The acceleration signals α _{1 to} α ₄ shaped by the filter 50 and the control command values u ₁ and u ₂ calculated by the transfer function 60 are added by the adding unit 36. By this process, an estimated value SPL_est of the noise in the control space 100 created by the vibration entering from the outside of the vehicle and the vibration generated by the actuator 20 is calculated.

  FIG. 5 shows a flowchart of processing performed by the noise estimation unit 35.

In step S <b> 201, the acceleration signals α _{1 to} α _{4 of} the acceleration sensors _{10 a to 10} d are A / D converted by the A / D conversion units 33 a to 33 d and input to the noise estimation unit 35. After this, the flow moves to step S202.

In step S202, the control command values u ₁ and u _{2 of the} previous step are A / D converted by the A / D conversion units 33e and 33f and input to the noise estimation unit 35. After this, the flow moves to step S203.

In step S203, W ₁ is multiplied by a filter 50 which has been previously stored in the acceleration signal alpha ₁ input in S201. Similarly, W ₂ is a filter 50 to the acceleration signal alpha ₂ is the W ₃ is a filter 50 to the acceleration signal alpha _3, W ₄ are multiplied is a filter 50 to the acceleration signal alpha _4. After this, the flow moves to step S204.

In step S204, the control command value u ₁ input in S202, G _p1 is multiplied is a filter 60a showing a transfer function from the input voltage to the actuator 20a which is stored in advance to the sound pressure in the control space 100 Is done. Similarly, the control command value u _2, G _p2 is a filter 60b showing a transfer function from the input voltage to the actuator 20b until the sound pressure at the control space 100 is multiplied.

  Here, the filter 60a and the filter 60b are set in advance as IIR filters by performing inverse Z conversion after identifying the transfer function from the input voltage of the actuator 20 to the noise as a discrete time system. After this, the flow moves to step S205.

  In step S205, all the signals obtained in S203 and S204 are added by the adder 36, and the obtained signal is output as an estimated noise value SPL_est.

  Next, a method for determining the filter 50 will be described.

FIG. 6 shows the relationship between input vibration (vibration source) to the vehicle body, acceleration, and vehicle interior noise. The input vibration f to the vehicle body is transmitted to the acceleration sensors 10a, 10b, 10c, and 10d through the transfer function H (s). On the other hand, the input vibration f propagates air in the vehicle interior and becomes noise in the control space 100. The transfer function of air propagation at this time is set as R (s). Further, the accelerations detected by the acceleration sensors 10a, 10b, 10c, and 10d are set as α ₁ , α ₂ , α ₃ , and α ₄ , respectively. Furthermore, the road noise measured in the control space 100 is set as SPL. At this time, the Laplace transform of the input vibration f is f _L (s), the Laplace transform of the signal SPL is SPL _L (s), and the Laplace transform of the acceleration signals α ₁ , α ₂ , α ₃ , α ₄ is α _L1 (s ), Α _L2 (s), α _L3 (s), and α _L4 (s), the relationship between the signals is expressed by the following equation.

  Here, H is a 4 × 1 matrix in which each element is a transfer function. In order to estimate the estimated noise value SPL_est from the acceleration signal of the acceleration sensor 10 using this relational expression, (Equation 7) is solved for f on the contrary and substituted into (Equation 6). Therefore,

It is represented by Here, H ⁺ represents an inverse matrix of the transfer function matrix H (s). Here, since H is not a square matrix but a square matrix, an inverse matrix cannot be calculated. Therefore, the pseudo inverse matrix

Calculate using. However, when m _H is the number of rows of _H and n _H is the number of columns of H,

It is a necessary condition to be able to calculate H ⁺ .

Since RH ⁺ is a 1-by-4 matrix, its elements are

(Formula 8) is

And can be transformed. W ₁ , W ₂ , W ₃ and W ₄ appearing here are set as filters 50a, 50b, 50c and 50d shown in FIG. Therefore, the filter 50 (W) for the acceleration signals α _{1 to} α ₄ is

Determined by the column vector.

  FIG. 7 shows a flowchart of the above process.

  In step S301, a transfer function R and a transfer function H are calculated. These may be calculated in advance and stored as data. After this, the flow moves to step S302.

In step S302, based on the transfer function H, the function H ⁺ = (H ^T · H) ⁻¹ · H ^T is calculated. After this, the flow moves to step S303.

In step S303, the filter 50 is calculated as W = RH ⁺ .

  An example of the frequency response of the filter 50 obtained by the above method is shown in FIG. The graphs 8A to 8D in FIG. 8 respectively show the acceleration sensors 10a to 10d. The dotted line in the figure shows the transfer function from the acceleration signal of each acceleration sensor 10 to the noise in the control space 100, and the solid line shows the characteristic of the function obtained by multiplying the transfer function by the filter 50 calculated by (Equation 13). ing. Here, when the dotted line and the solid line are close to each other in a certain frequency band, it indicates that the filter 50 has performed a large weighting on the acceleration signal in the frequency band detected by the acceleration sensor 10. For example, when attention is paid to the vicinity of 300 Hz in the graphs 8A to 8D in FIG. 8, the solid line and the dotted line are close to each other in the graph 8C, and the solid line and the dotted line are separated in the other graphs 8A, 8B, and 8D. In this case, the acceleration signal of the acceleration sensor 10c is heavily weighted in the vicinity of 300 Hz, and the acceleration signals of the other acceleration sensors 10 are lightly weighted.

  FIG. 9 shows the measured noise value and the estimated noise value SPL_est calculated using the filter 50 described above. A dotted line indicates the measured noise value, and a solid line indicates the estimated noise value SPL_est calculated by the noise estimating unit 35. FIG. 9 shows that the estimated noise value SPL_est is accurately calculated by using the present embodiment. Thus, in this embodiment, the noise in the vehicle interior can be estimated with high accuracy, and the vehicle interior noise can be effectively reduced.

  With the processing described above, noise in the vehicle interior can be estimated with high accuracy and noise control for reducing the noise in the vehicle interior can be effectively performed. However, when the actuator 20 breaks down, it is not possible to generate an appropriate wave for reducing the noise in the passenger compartment, making it difficult to effectively perform noise control. Depending on the case, an inappropriate wave may be generated from the actuator 20 and the noise may increase.

  In the present embodiment, the noise control is performed only when the failure of the actuator is not detected, assuming that the noise control effect cannot be obtained when the failure of the actuator is detected.

  The structure of the noise estimation unit 35 in this embodiment is shown in FIG.

  In the present embodiment, the test signal generator 40 outputs a test signal to the actuator 20 when the vehicle is stopped. At that time, the failure of the actuator 20 is determined based on the acceleration signal detected by the acceleration sensor 10, and noise control is performed only when the failure of the actuator 20 is not detected. Noise control is not performed during test signal generation.

  Hereinafter, the failure determination process of the actuator 20 will be described with reference to the flowchart of FIG. 10 and the transfer function explanatory diagram of FIG.

In step S401, with respect to the actuator i of the actuator 20 to perform failure determination (i = 1, 2), the frequency f _i of the test signal S _i is set. Here, let the actuators 20a and 20b be actuators 1 and 2. After this, the flow moves to step S402.

In step S402, the test signal generating section 40 outputs a test signal S _i of the frequency f _i to the actuator i, actuator i performs oscillation amplitude V _i. That is, in the case of i = 1, output the test signals S ₁ of the test signal generator 40 frequency f ₁ to the actuator 1, the actuator 1 performs oscillation of the oscillating V _1. For i = 2, and outputs the test signal S ₂ of the test signal generator 40 is frequency f ₂ to the actuator 2, the actuator 2 performs the vibration of the vibration V _2. After this, the flow moves to step S403.

In step S403, it is determined whether or not the detection signal of the acceleration sensor j is equal to the value obtained by multiplying the amplitude V _i of the actuator i by the transfer function GA _{i, j} between the actuator i and the acceleration sensor j. If this condition is met, the flow moves to step S404. On the other hand, if the condition is not satisfied, the flow moves to step S406.

  In step S404, it is determined whether or not the determination in step S403 has been made for all acceleration sensors j. If the determination in step S403 is made for all the acceleration sensors j, the flow proceeds to step S405. On the other hand, if the determination in step S403 has not been performed for all acceleration sensors j, the flow returns to step S403, and the determination in S403 is performed for the next acceleration sensor j.

In step S405, the actuator i is oscillating with the amplitude V _i corresponding to the test signal S _i , and it is determined that the actuator i is normal. After this, the flow moves to step S408.

In step S406, the actuator i does not vibrate with the amplitude V _i corresponding to the test signal S _i , and it is determined that the actuator i is in failure. After this, the flow moves to step S407.

  In step S407, since the failure of the actuator i is detected, the noise control is not performed and the operation is stopped. After this, the flow moves to step S410.

  In step S408, it is determined whether or not the failure determination in steps S403 and S404 has been performed for all actuators i. If failure determination has been performed for all actuators i, the flow proceeds to step S409. On the other hand, if failure determination has not been performed for all actuators i, the flow returns to step S401, and failure determination for the remaining actuators i is continued.

  In step S409, since the failure of the actuator i is not detected, the noise control described above is performed. After this, the flow moves to step S410.

  In step S410, the process ends.

Here, when the test signal S _i generated by the test signal generator 40 is output to the actuator i, the actuator i vibrates to generate noise in the vehicle interior. For this reason, the frequency f _{i of the} test signal is selected such that the noise becomes as small as possible in the audible frequency band of the passenger. Specifically, as shown in FIG. 12, the transfer function GS _i, the frequency f the gain of _k becomes minimum between the actuator i and the control space k, and the frequency f _i of the test signal S _i. In FIG. 12, the frequency f _{1 at} which the gain of the transfer function GS _{i, k} is equal to or less than a predetermined value GS0 is defined as the frequency f _i of the test signal S _i . If this condition is expressed by a formula,

It becomes.

Note that f _min and f _max represent the lower limit and the upper limit of the frequency of the test signal, respectively.

If the control space 100 there are a plurality, transfer functions GS _{i, k} between the actuator i and the control space k is different for each control space, even when a noise due to the test signal S _i in the control space 100 there is minimal In other control spaces 100, noise due to the test signal S _i is not necessarily minimized. Thus, as in all of the control space 100 is noise due to the test signal S _i becomes as small as possible, it is the embodiment to set the frequency f _i of the test signal S _i.

Specifically, each test signal S _i of each actuator i, the frequency f _i of the noise due to the test signals S _i in each control space k is as small as possible leave multiple selection, test signals in the plurality of control space 100 Select a common frequency f _i of S _i . For example, it is assumed that there are two control spaces 100 (control spaces 1 and 2) and one actuator 20 (actuator 1). In this case, as shown in FIG. 13, the candidate of the frequency of the test signals S ₁ in the control space 1 and f _1, f _2, a candidate frequency of the test signal S ₂ in the control space 2 and f _3, f ₄ . Of these, if f ₁ and f ₃ are equal, this frequency is set as the frequency of the test signals S ₁ and S ₂ .

Incidentally, the candidate frequencies f _i, in that you selected as a frequency band, it is easy to set the common frequency f _i.

If this condition is expressed by a formula,
In order to reduce the noise SPL _k (f) due to the test signal having the frequency f in the k control spaces 100 as much as possible,

Should be minimized.
Here, assuming that | V _i (f) | ² is a constant (for example, = 1),

That is,

It becomes.

In this embodiment, with respect to the embodiment described above, in which the selection of the test signal S _i different, structure and process flow are the same. Therefore, only the selection of the test signal S _i will be described.

In the above-described embodiment, the test signal _Si is selected so that the noise becomes as small as possible in the audible frequency band of the occupant. However, in the present embodiment, the acceleration sensor has a frequency where the noise becomes as small as possible in the audible frequency band of the occupant. The frequency at which the acceleration signal detected by 10 is as large as possible is selected as the frequency f _i of the test signal S _i .

14, the occupant of the audible frequency band, the gain of the transfer function GA _{i, j} between the transfer function GS i between actuator i and the control space _k, the gain characteristic of _k, the actuator i and the acceleration sensor j Show properties. In the upper diagram of FIG. 14, the frequency f _i of the test signal S _i is selected from the frequencies f ₅ and f _{6 at} which the gain of the transfer function GS _{i, k} between the actuator i and the control space k is equal to or less than a predetermined value GS1. Become. Here, in the lower diagram of FIG. 14, the value of the acceleration signal detected by the acceleration sensor 10 is small at the frequency f _{6 at} which the gain of the transfer function GA _{i, j} between the actuator i and the acceleration sensor j is equal to or less than the predetermined value GA1. The frequency f _i of the test signal S _i is not selected, and f ₅ is selected.

  When the condition of FIG.

Here, α _{i, j} (f) represents the acceleration signal of the actuator i detected by the acceleration sensor j.

  In a plurality of control spaces, the conditions for reducing the noise as much as possible in the audible frequency band of the passenger are as follows:

Should be as small as possible.

  On the other hand, the condition that the acceleration signal detected by the acceleration sensor 10 is as large as possible is:

It becomes. Here, α ε _(f) is a _{GA i, j (f) =} GA i, when the _{opt (f) α i, j} (f). GA _{i, opt} (f) represents GA _{i, j} at a frequency at which the gain of the transfer function GA _{i, j} is equal to or greater than a predetermined value.

  This formula is expressed in a more easy-to-understand manner by modifying it as follows using, for example, a logarithm.

  When there are a plurality of actuators 20, it is necessary to determine the failure of each actuator 20. The processing flow at this time is shown in FIG.

  In step S501, among the actuators 20, the actuator i that performs failure determination is selected as i = 1. After this, the flow moves to step S502.

In step S502, the frequency f _i of the test signal S _{i for} the actuator _i is set. The frequency f _i is selected so that the noise becomes as small as possible in the audible frequency band of the occupant and the acceleration signal detected by the acceleration sensor 10 is as large as possible. After this, the flow moves to step S503.

  In step S503, failure determination of the actuator i is performed. The failure determination method is the same as in the above-described embodiment. After this, the flow moves to step S504.

  In step S504, it is determined whether failure determination has been performed for all actuators i. When failure determination of all actuators i has been performed, the flow moves to step S506, and the process ends. On the other hand, if failure determination of all actuators i has not been performed, the flow moves to step S505.

  In step S505, i = i + 1 is set, and the actuator i that performs the next failure determination is selected. After this, the flow moves to step S502, and the failure determination of the actuator i is continued.

In the present embodiment, the failure determination is performed by selecting one frequency f _{i at} which the test signal S _i detected by the plurality of acceleration sensors 10 is as large as possible.

In order to select one frequency f _i that maximizes the acceleration signal detected by each acceleration sensor j of the plurality of acceleration sensors 10 as the frequency f _i of the test signal S _i , each actuator i, each acceleration sensor j, What is necessary is just to obtain | require the frequency in the intersection of transfer function GAi _{, j} between.

FIG. 16 shows two acceleration sensors 10 (acceleration sensors 1 and 2), actuator 2
An example of setting the frequency f1 of the test signal S1 when 0 is one is shown. In FIG. 16, a curve indicated by a rough dotted line indicates the gain characteristic of the transfer function GA ₁ , ₁ between the acceleration sensor 1 and the actuator 1, and a curve indicated by a fine dotted line indicates the distance between the acceleration sensor 2 and the actuator 1. The gain characteristics of the transfer functions GA _{1 and 2} are shown. The frequency at which the test signal S1 detected by both the acceleration sensor 1 and the acceleration sensor 2 becomes as large as possible is the frequency f _{opt at} the intersection of the two curves.

  The processing flow of this embodiment is shown in FIG.

  In step S601, among the actuators 20, the actuator i that performs failure determination is selected as i = 1. After this, the flow moves to step S602.

In step S602, the intersection of the gain characteristics of the transfer functions GA _{i, j} between the actuator i and the plurality of acceleration sensors j is calculated.

In step S603, the frequency at the intersection calculated in step S602 is set as the frequency f _i of the test signal S _i of the actuator i. This frequency f _i is a frequency at which the acceleration signals detected by the plurality of acceleration sensors i become as large as possible. After this, the flow moves to step S604.

  In step S604, failure determination of the actuator i is performed. The failure determination method is the same as in the above-described embodiment. After this, the flow moves to step S605.

  In step S605, it is determined whether failure determination has been performed for all actuators i. If failure determination of all actuators i has been performed, the flow moves to step S607 and the process ends. On the other hand, if failure determination of all actuators i has not been performed, the flow moves to step S606.

  In step S606, i = i + 1 is set, and the actuator i that performs the next failure determination is selected. After this, the flow moves to step S602, and the failure determination of the actuator i is continued.

Incidentally, the set frequency f _i is, if contained in a frequency band as possible noise is reduced in the passenger audible frequency band, the frequency f _i, the test signal S _i in which a plurality of the acceleration sensor 10 detects the as large as possible In addition, the noise becomes as low as possible in the audible frequency band of the passenger.

  According to the noise control device of the embodiment of the present invention described above, the following operational effects can be obtained.

The invention of claim 1 is arranged on a vehicle body of a vehicle, and a plurality of sensors for detecting vibrations of the vehicle body,
A wave applying unit that applies a wave controlled by a control unit to the vehicle body; and the control unit transmits the wave to the wave applying unit between the wave applying unit and a predetermined space in a vehicle interior of the vehicle. A wave applying unit that detects a failure of the wave applying unit based on an output signal of the sensor when a signal having a predetermined frequency set for each of the predetermined spaces is output so that the gain of the function is a predetermined value or less. A failure detection unit; and a noise estimation unit that calculates an estimated value of vehicle interior noise that can be heard in a predetermined space in the vehicle interior of the vehicle based on output signals of the plurality of sensors, and the control unit When the failure of the wave application unit is not detected by the application unit failure detection unit, the vehicle interior noise is output by outputting the wave to the wave application unit based on the estimated value of the vehicle interior noise calculated by the noise estimation unit. Reduce It is characterized by performing the noise control.

According to this apparatus, it is assumed that the noise control effect cannot be obtained when an actuator failure is detected, and the noise control can be effectively performed only when the actuator failure is not detected. In addition, it is possible to reduce the noise generated in a predetermined space as much as possible when detecting the failure of the wave application unit, and the comfort of the passenger is not greatly impaired by the noise when detecting the failure of the wave application unit .

According to a second aspect of the present invention, in the noise control device according to the first aspect, the predetermined frequency of the signal is a plurality of transfer functions of the wave between the wave applying unit and the plurality of predetermined spaces. The one frequency is set so that the gain of each of the plurality of predetermined spaces is not more than a predetermined value in the plurality of predetermined spaces.

  According to this apparatus, it is possible to reduce the noise generated in a plurality of predetermined spaces as much as possible when detecting the failure of the wave application unit, and the comfort of the occupant due to the noise when detecting the failure of the wave application unit Is not greatly impaired.

According to a third aspect of the present invention, in the noise control device according to the first or second aspect , the predetermined frequency of the signal is a predetermined gain of a transfer function of the wave between the wave applying unit and the sensor. It is set for each sensor so as to be equal to or greater than the value, and the wave application unit failure detection unit detects the failure of the wave application unit by sequentially switching the frequency set for each sensor.

  According to this apparatus, it is possible to make the signal detected by the sensor as large as possible when detecting the failure of the wave application unit, and it is possible to reliably detect the failure of the wave application unit.

According to a fourth aspect of the present invention, in the noise control device according to the first or second aspect , the predetermined frequency of the signal is a plurality of transfer functions of the wave between the wave applying unit and the plurality of sensors. One frequency is set as the frequency at the intersection of the gains.

  According to this apparatus, it is possible to make the signal detected by the sensor as large as possible when detecting the failure of the wave application unit, and it is possible to reliably detect the failure of the wave application unit. In addition, since one signal frequency is set such that signals detected by a plurality of sensors are as large as possible, failure detection of the wave application unit can be performed efficiently.

According to a fifth aspect of the present invention, in the noise control device according to any one of the first to fourth aspects, the detection of the failure of the wave application unit by the wave application unit failure detection unit is performed while the vehicle is stopped. It is characterized by being performed.

  According to this apparatus, since the failure detection of the wave application unit is performed while the vehicle is stopped, the failure detection of the wave application unit can be reliably performed without being affected by road noise.

Furthermore, the invention of claim 6 is the noise control device according to any one of claims 1 to 5 , wherein the wave is a vehicle body vibration applied to the vehicle body or a sound generated in the vehicle interior of the vehicle body. It is characterized by being.

  According to this device, vehicle interior noise can be easily reduced by applying vibration or sound to the vehicle body.

  Further, according to the noise control method of the embodiment of the present invention described above, the following operational effects can be obtained.

The invention of claim 7 detects the vibration of the vehicle body of the vehicle at a plurality of detection points;
Calculating an estimated value of vehicle interior noise heard in a predetermined space in the vehicle interior of the vehicle based on the vibration, applying a controlled wave to the vehicle body by a wave application location installed on the vehicle body, A signal having a predetermined frequency set for each predetermined space is output to a wave application location so that the gain of the transfer function of the wave between the wave application location and the predetermined space is a predetermined value or less. And detecting the failure of the wave application location by the vibration detected by the detection location, and applying the wave based on the estimated value of the vehicle interior noise when no failure is detected in the wave application location. And applying noise control to a location to reduce noise in the vehicle interior.

According to this method, it is assumed that the noise control effect cannot be obtained when a failure at the wave application location is detected, and the noise control is performed effectively only when the failure at the wave application location is not detected. In addition, it is possible to reduce the noise generated in a predetermined space as much as possible when detecting a failure at a wave application location, and greatly reduce the passenger comfort due to the noise when detecting a failure at a wave application location. There is nothing .

The invention according to claim 8 is the noise control method according to claim 7 , wherein the predetermined frequency of the signal is a plurality of transfer functions of the wave between the wave application location and the plurality of predetermined spaces. The one frequency is set so that the gain of each of the plurality of predetermined spaces is not more than a predetermined value in the plurality of predetermined spaces.

  According to this method, it is possible to reduce the noise generated in a plurality of predetermined spaces as much as possible when detecting a failure at a wave application location. Is not greatly impaired.

The invention according to claim 9 is the noise control method according to claim 7 or 8 , wherein the predetermined frequency of the signal is a gain of a transfer function of the wave between the wave application location and the detection location. It is set for each detection point so as to be equal to or greater than a predetermined value, and the frequency set for each detection point is sequentially switched to detect a failure at the wave application point.

  According to this method, it is possible to make the vibration detected at the detection location as large as possible when performing the failure detection at the wave application location, and the failure detection at the wave application location can be reliably performed.

The invention of claim 10 is the noise control method according to claim 7 or 8, the predetermined frequency of said signal, a plurality of transmission of the wave between the wave applied portion and the plurality of detection points One frequency is set as the frequency at the intersection of the gains of the functions.

  According to this method, it is possible to make the vibration detected at the detection location as large as possible when performing the failure detection at the wave application location, and the failure detection at the wave application location can be reliably performed. In addition, since one frequency of a signal is set so that vibration detected at a plurality of detection locations is as large as possible, failure detection at the wave application location can be performed efficiently.

The invention according to claim 11 is the noise control method according to any one of claims 7 to 10 , wherein the detection of the failure at the wave application location is performed while the vehicle is stopped.

  According to this method, since the failure detection of the wave application location is performed while the vehicle is stopped, the failure detection of the wave application location can be reliably performed without being affected by road noise.

The invention according to claim 12 is the noise control method according to any one of claims 7 to 11 , wherein the wave is a vehicle body vibration applied to the vehicle body or a sound generated in the vehicle interior of the vehicle body. It is characterized by being.

  According to this method, vehicle interior noise can be easily reduced by applying vibration or sound to the vehicle body.

  As mentioned above, although the Example of this invention was explained in full detail with drawing, an Example is only an illustration of this invention and this invention is not limited only to the structure of an Example. Accordingly, it is a matter of course that the present invention includes any design change within a range not departing from the gist of the present invention.

  For example, the number of acceleration sensors 10 is not limited to four, and a necessary number can be set.

  The number of piezoelectric actuators 20 is not limited to two, and an arbitrary number smaller than the number of acceleration sensors 10 can be set.

  Further, the feedback control performed by the calculation unit 38 is not limited to the H∞ control, and any feedback control may be used.

  In the above description, the application example to the case of road noise reduction has been described. However, the present invention can also be applied to other noises. For example, when used for engine noise, noise control of engine noise can be performed by installing the acceleration sensor 10 on a floor panel and a dash panel (not shown). Moreover, when using with respect to a wind noise, the noise control of a wind noise can be performed by installing the acceleration sensor 10 in a front pillar (illustration omitted) and a roof (illustration abbreviation).

It is a figure which shows the main propagation path of the vibration of a vehicle body by the influence of the unevenness | corrugation of a road surface, and road noise. 1 is a schematic diagram of a noise control device according to the present embodiment. It is a block diagram which shows the internal structure of a control command value calculation part. It is a flowchart of the noise control in a control apparatus main body. It is a flowchart of the process in a noise estimation part. It is a figure which shows the relationship between the vibration source signal to a vehicle body, acceleration, and vehicle interior noise. It is a flowchart of a filter calculation process. It is a figure which shows the frequency response example of the filter by this embodiment. It is a comparison figure of the measured value and estimated value of noise. It is a flowchart of the failure determination process of an actuator. It is explanatory drawing of a transfer function. It is a frequency characteristic figure of the transfer function between an actuator and control space. It is another frequency characteristic figure of a transfer function between an actuator and control space. It is a frequency characteristic figure of the transfer function between an actuator and control space, and the transfer function between an actuator and an acceleration sensor. 10 is a flowchart of processing in Embodiment 2. 10 is an explanatory diagram of a method for setting a frequency of a test signal in Embodiment 3. 10 is a flowchart of processing in Embodiment 3.

Explanation of symbols

10, 10a-10d Acceleration sensor (sensor)
20, 20a, 20b Actuator (wave application unit)
30 Control device body 31, 31a to 31f Amplifying unit 32 Control command value calculating unit 33, 33a to 33f A / D conversion unit 34 Drive unit failure detection unit (wave application unit failure detection unit)
35 noise estimation unit 36 addition unit 37 control unit 38 calculation unit 39 D / A conversion unit 40 test signal generation unit 50, 50a to 50d filter 60 60a, 60b transfer function 100 control space (predetermined space)
110 Floor panel 120 Axle 130 Suspension 140 Member 200 Tire

Claims (12)

A plurality of sensors disposed on the vehicle body for detecting vibrations of the vehicle body;
A wave applying unit for applying a wave controlled by the control unit to the vehicle body;
For each predetermined space, the control unit causes the wave applying unit to have a gain of a transfer function of the wave between the wave applying unit and a predetermined space in the vehicle interior of the vehicle not more than a predetermined value. A wave application unit failure detection unit that detects a failure of the wave application unit based on an output signal of the sensor when a signal having a predetermined frequency to be set is output;
A noise estimation unit that calculates an estimated value of vehicle interior noise heard in the predetermined space based on the output signals of the plurality of sensors;
And the controller applies the wave applying unit based on the estimated value of the vehicle interior noise calculated by the noise estimating unit when the failure of the wave applying unit is not detected by the wave applying unit failure detecting unit. A noise control apparatus for performing noise control for outputting the wave to the vehicle to reduce the vehicle interior noise.   The predetermined frequency of the signal is such that the gains of the plurality of transfer functions of the wave between the wave applying unit and the plurality of the predetermined spaces are both equal to or less than a predetermined value in the plurality of the predetermined spaces. The noise control device according to claim 1, wherein one frequency is set. The predetermined frequency of the signal is set for each sensor so that the gain of the transfer function of the wave between the wave applying unit and the sensor is a predetermined value or more, and the wave applying unit failure detecting unit is noise control device according to claim 1 or 2 sequentially switches the frequency set for each sensor and detects a failure of the wave applying section. The predetermined frequency of the signal is set to one frequency as a frequency at an intersection of gains of a plurality of transfer functions of the wave between the wave applying unit and the plurality of sensors. The noise control apparatus according to 1 or 2 . The noise control device according to any one of claims 1 to 4 , wherein the detection of a failure of the wave application unit by the wave application unit failure detection unit is performed while the vehicle is stopped. The wave is noise control apparatus according to any one of claims 1 to 5, characterized in that a sound generator to the passenger compartment of the vehicle body vibration or the vehicle body is applied to the vehicle body. Detecting vibrations of a vehicle body at a plurality of detection points;
Calculating an estimated value of vehicle interior noise heard in a predetermined space in the vehicle interior of the vehicle based on the vibration;
Applying a controlled wave to the vehicle body by a wave application point installed on the vehicle body;
A signal having a predetermined frequency that is set for each predetermined space is applied to the wave application location so that a gain of a transfer function of the wave between the wave application location and the predetermined space is a predetermined value or less. A step of detecting a failure of the wave application location by the vibration detected by the detection location when output;
And performing noise control for reducing the vehicle interior noise by applying the wave to the wave application location based on the estimated value of the vehicle interior noise when a failure of the wave application location is not detected. Noise control method. The predetermined frequency of the signal is such that the gains of the plurality of transfer functions of the wave between the wave application location and the plurality of the predetermined spaces are not more than a predetermined value in the plurality of the predetermined spaces. The noise control method according to claim 7 , wherein one frequency is set. The predetermined frequency of the signal is set for each detection point so that the gain of the transfer function of the wave between the wave application point and the detection point is a predetermined value or more, and is set for each detection point. 9. The noise control method according to claim 7, wherein a failure of the wave application location is detected by sequentially switching the frequencies. The predetermined frequency of the signal is set to one frequency as a frequency at an intersection of gains of a plurality of transfer functions of the wave between the wave application place and the plurality of detection places. Item 9. The noise control method according to Item 7 or 8 . The failure detection of the wave application location is performed while the vehicle is stopped.
The noise control method according to any one of 7 to 10 . The noise control method according to any one of claims 7 to 11 , wherein the wave is a vehicle body vibration applied to the vehicle body or a sound generated in the vehicle interior of the vehicle body.

Images