JP2010179842A - Active noise vibration control device, active noise vibration control device for vehicle, and active noise vibration control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect divergence inclination in an early stage when the divergence inclination is present on secondary noise or secondary vibration. <P>SOLUTION: The phase difference of a first reference signal and a second reference signal can be changed to an angle other than 90°. Therefore, when the filter coefficient of first and second one-tap adaptation filter is diverted, two filter coefficients are successively renewed so as to draw a track of elliptical shape at a periphery of the optimum point on a two-dimensional plane making the two filter coefficients as respective axes. As a result, the divergence inclination of the filter coefficient is increased, a first control signal, a second control signal, a synthesized control signal and an error signal are increased. Accordingly, the divergence inclination present on the secondary noise or the secondary vibration can be detected in an early stage by performing determination based on those signals. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active noise vibration control apparatus, a vehicle active noise vibration control apparatus, and an active noise vibration control method that generate secondary noise that interferes with noise or secondary vibration that interferes with vibration.

Conventionally, as this type of technology, for example, there is a technology described in Patent Document 1.
In the technique described in Patent Document 1, first, a sine wave signal and a cosine wave signal synchronized with the rotation of the engine are generated. Next, the generated sine wave signal is multiplied by the filter coefficient of the first one-tap adaptive filter, the cosine wave signal is multiplied by the filter coefficient of the second one-tap adaptive filter, and the multiplication results are combined to control synthesis. Generate a signal. Next, a secondary noise is generated by driving a speaker in the vehicle interior based on the generated composite control signal. Here, the secondary noise is a sound for interfering with noise generated by the rotation of the engine and canceling the noise.

In this technique, the first and second transfer functions are used to simulate the transfer characteristic of the sound field from the position of the speaker to the position of the microphone based on the error signal from the sine wave signal, cosine wave signal and noise. The filter coefficients of the 1-tap adaptive filter are updated sequentially.
The error signal is a signal that represents a detection result of residual noise generated by interference with secondary noise. Further, the update of the filter coefficient employs a SAN (Single frequency Adaptive Notch filter) algorithm which is a kind of Filtered-X LMS algorithm.

JP 2007-45350 A

By the way, in the technique described in Patent Document 1, when the error between the transfer function and the actual transfer characteristic increases, the convergence of the filter coefficients of the first and second one-tap adaptive filters decreases. When the filter coefficients diverge, the two filter coefficients are sequentially updated so as to rotate around the optimum point while the radius of rotation gradually increases on a two-dimensional plane having the two filter coefficients as axes. Therefore, there is a possibility that the secondary noise generated by the speaker gradually increases and diverges due to the updated filter coefficient, and the residual noise increases.
Such a problem occurs not only in a technique for generating secondary noise that interferes with noise but also in a technique for generating secondary vibration that interferes with vibration.
The present invention pays attention to the above points, and when the secondary noise or the secondary vibration has a divergence tendency, an object of the present invention is to enable early detection of the divergence tendency.

  In order to solve the above problems, the present invention is based on whether or not secondary noise or secondary vibration tends to diverge based on at least one of an error signal, a combined control signal, a first control signal, and a second control signal. Judgment was made. Further, the phase difference between the first reference signal and the second reference signal can be changed to a value larger than 0 degree and smaller than 90 degrees.

  According to the present invention, the phase difference between the first reference signal and the second reference signal can be changed to other than 90 degrees. Therefore, the contour lines of the error surface can be made elliptical. Therefore, when there is a sign of a divergence tendency, when the filter coefficient diverges by changing the phase difference to other than 90, around the optimum point on the two-dimensional plane with the two filter coefficients as axes. Are sequentially updated so as to draw an elliptical trajectory. As a result, when the two filter coefficients move from the short side to the long side of the elliptical orbit, the distance between the filter coefficient and the optimum point increases, and the divergence tendency of the filter coefficient increases. The first control signal, the second control signal, the composite control signal, and the error signal increase. Therefore, by making a determination based on these signals, it is possible to detect early that the secondary noise or the secondary vibration has a tendency to diverge.

It is a conceptual diagram of the apparatus structure of the vehicle provided with the active noise control apparatus of 1st Embodiment. It is a block diagram showing the content of the arithmetic processing which the control apparatus 7 performs. It is a flowchart which shows the arithmetic processing which the control state detection part 14 performs. It is a flowchart which shows the arithmetic processing which the abnormality detection part 15 performs. It is a figure which shows the axis | shaft of an error surface. It is a figure which shows the relationship between the phase difference between these signals, and the shape of an error surface, when the phase difference between a 1st reference signal and a 2nd reference signal is 90 degree | times. It is a figure which shows the relationship between the phase difference between those signals, and the shape of an error surface, when the phase difference between a 1st reference signal and a 2nd reference signal is 0 degree or more and less than 90 degree | times. FIG. 6 is a diagram showing the operation of the active noise control device 8. It is a figure for demonstrating a comparative example. It is a figure which shows operation | movement of an application example. It is a figure which shows operation | movement of an application example. It is a conceptual diagram of the apparatus structure of an application example. It is a block diagram showing the content of the arithmetic processing which the control apparatus 7 of 2nd Embodiment performs. It is a flowchart which shows the arithmetic processing which the control state detection part 14 performs. It is a flowchart which shows the arithmetic processing which the abnormality detection part 15 performs. It is a block diagram showing the content of the arithmetic processing which the control apparatus 7 of an application example performs. It is a block diagram showing the content of the arithmetic processing which the control apparatus 7 of 3rd Embodiment performs. It is a flowchart which shows the arithmetic processing which the control state detection part 14 performs. FIG. 6 is a diagram showing the operation of the active noise control device 8. It is a block diagram showing the content of the arithmetic processing which the control apparatus 7 of 4th Embodiment performs. It is a flowchart which shows the arithmetic processing which the control state detection part 14 performs. FIG. 6 is a diagram showing the operation of the active noise control device 8.

Next, an embodiment according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a conceptual diagram of an apparatus configuration of a vehicle including an active noise control apparatus according to the first embodiment.
(Constitution)
As shown in FIG. 1, the vehicle 1 includes an engine 2, a rotation frequency detection device 3, a power amplifier 4, a speaker 5, a microphone 6, and a control device 7. In the present embodiment, the engine 2 constitutes a noise source, and the rotational frequency detection device 3, the power amplifier 4, the speaker 5, the microphone 6, and the control device 7 constitute an active noise control device 8.

  The engine 2 generates an engine muffled sound as noise to be canceled. Engine muffled sound is vibration radiated sound that is generated when the excitation force generated by the rotation of the engine 2 is transmitted to the vehicle body. For example, in a four-cycle four-cylinder engine, gas combustion that occurs every ½ rotation of the engine output shaft generates excitation vibration having a periodicity with the engine 2 as a base point. Vibration sound is generated in the room.

The rotation frequency detection device 3 detects an engine pulse signal. The engine pulse signal is a signal synchronized with the rotation of the engine 2. Then, the rotation frequency detection device 3 outputs the detected engine pulse signal to the control device 7. For example, a top dead center sensor can be used.
The power amplifier 4 amplifies the signal output from the control device 7. Then, the amplified signal is output to the speaker 5.
The speaker 5 generates secondary noise that interferes with engine noise due to the signal output from the power amplifier 4.

The microphone 6 is disposed in a room trif in the vehicle interior. Then, the residual noise generated by the interference of the secondary noise generated by the speaker 5 with the engine noise is detected. The microphone 6 outputs the detection result to the control device 7 as an error signal e.
The control device 7 is composed of a microprocessor. The microprocessor includes an integrated circuit including an A / D conversion circuit, a D / A conversion circuit, a central processing unit, a memory, and the like. Then, according to the program stored in the memory, arithmetic processing is performed based on the signals detected by the rotation frequency detection device 3 and the microphone 6, and the result is output to the speaker 5.

Next, the contents of the arithmetic processing executed by the control device 7 will be described using a block diagram.
FIG. 2 is a block diagram showing the contents of the arithmetic processing executed by the control device 7.
As shown in FIG. 2, this block diagram shows a first reference signal generation unit 9, a phase setting unit 10, a second reference signal generation unit 11, an adaptive filter 12, a coefficient update unit 13, a control state detection unit 14, and an abnormality. A detection unit 15 is provided.
The first reference signal generation unit 9 generates a first reference signal based on the engine pulse signal output from the rotation frequency detection device 3. The first reference signal is a signal synchronized with the engine pulse signal. For example, a sine wave signal or a cosine wave signal can be used. Then, the first reference signal generation unit 9 outputs the generated first reference signal to the adaptive filter 12 and the coefficient update unit 13.

  The phase setting unit 10 changes the phase of the engine pulse signal output from the rotational frequency detection device 3 to the phase setting unit 10 by 90 degrees or the set value α in accordance with the signal from the control state detection unit 14. Here, the set value α is a phase value of 0 degree or more and less than 90 degrees, that is, a phase value other than 90 degrees. As a method for changing the phase of the engine pulse signal, a method for delaying the phase or a method for advancing the phase can be used. Then, the phase setting unit 10 outputs the engine pulse signal whose phase has been changed to the second reference signal generation unit 11.

  The second reference signal generation unit 11 generates a second reference signal based on the engine pulse signal after the phase change output from the phase setting unit 10. The second reference signal is a signal synchronized with the engine pulse signal after the phase change. For example, the same type of signal as the first reference signal, such as a sine wave signal or a cosine wave signal, can be used. Then, the second reference signal generation unit 11 outputs the generated second reference signal to the adaptive filter 12 and the coefficient update unit 13.

  Thus, the first reference signal generator 9 generates a first reference signal that is synchronized with the engine pulse signal. Further, the phase setting unit 10 changes the phase of the engine pulse signal by 90 degrees or the set value α, and the second reference signal generation unit 11 generates a second reference signal synchronized with the engine pulse signal after the phase change. . Therefore, a phase difference corresponding to the phase value changed by the phase setting unit 10 is generated between the first reference signal and the second reference signal.

The adaptive filter 12 includes a first one-tap adaptive filter 16, a second one-tap adaptive filter 17, and a synthesis control signal calculation unit 18.
The first one-tap adaptive filter 16 multiplies the first reference signal output from the first reference signal generation unit 9 by the filter coefficient W0. The filter coefficient W0 is a coefficient set by the coefficient updating unit 13, as will be described later. Then, the first one-tap adaptive filter 16 outputs the multiplication result to the synthesized control signal calculation unit 18 as the first control signal.

The second one-tap adaptive filter 17 multiplies the second reference signal output from the second reference signal generation unit 11 by the filter coefficient W1. The filter coefficient W1 is a coefficient set by the coefficient updating unit 13, as will be described later. Then, the second one-tap adaptive filter 17 outputs the multiplication result to the combined control signal calculation unit 18 as a second control signal.
The synthesis control signal calculation unit 18 synthesizes the first control signal output from the first one-tap adaptive filter 16 and the second control signal output from the second one-tap adaptive filter 17. Then, the combination result is output to the power amplifier 4 as a combination control signal.

The coefficient updating unit 13 includes a first transfer element 19, a second transfer element 20, a third transfer element 21, a fourth transfer element 22, a first combined signal generation unit 23, a second combined signal generation unit 24, and a first adaptive control. An algorithm calculator 25 and a second adaptive control algorithm calculator 26 are provided.
The first transfer element 19 inputs the first reference signal output from the first reference signal generator 9 to the correction filter C0. The correction filter C0 is a characteristic ReH (f) of the real part of the transfer function H that simulates the transfer characteristic of the sound field from the position of the speaker 5 to the position of the microphone 6. The transfer function H is a transfer characteristic at the temperature in the passenger compartment that is assumed when the vehicle is running with the vehicle window closed. Then, the first transfer element 19 outputs the signal output from the correction filter C0 to the first combined signal generation unit 23 in response to the input of the first reference signal.

  The second transfer element 20 inputs the second reference signal output from the second reference signal generation unit 9 to the correction filter C1. The correction filter C1 is a characteristic ImH (f) of the imaginary part of the transfer function H that simulates the transfer characteristic of the sound field from the position of the speaker 5 to the position of the microphone 6. Then, the second transfer element 20 outputs the signal output from the correction filter C1 to the first combined signal generation unit 23 in response to the input of the second reference signal.

The third transfer element 21 inputs the second reference signal output from the second reference signal generation unit 9 to the correction filter C0. Then, in response to the input of the second reference signal, a signal output from the correction filter C0 is output to the second synthesized signal generation unit 24.
The fourth transfer element 22 inputs the first reference signal output from the first reference signal generator 9 to the correction filter -C1. Then, in response to the input of the first reference signal, the signal output from the correction filter -C1 is output to the second synthesized signal generation unit 24.

The first synthesized signal generator 23 synthesizes the signal output from the first transfer element 19 and the signal output from the transfer element 20. Then, the synthesis result is output to the first adaptive control algorithm calculator 25 as the first simulation reference signal r0.
The second combined signal generation unit 24 combines the signal output from the third transfer element 21 and the signal output from the transfer element 22. Then, the synthesis result is output to the second adaptive control algorithm calculator 26 as the second simulation reference signal r1.

Based on the error signal e (n) output from the microphone 6 and the first simulated reference signal r0 (n) output from the first combined signal generator 23, the first adaptive control algorithm calculator 25 calculates the error signal e (n + 1). ) Is sequentially set so that the filter coefficient W0 (n + 1) of the first one-tap adaptive filter 16 is minimized. The filter coefficient W0 is set based on the SAN algorithm, which is a type of Filtered-X LMS algorithm. For example, the filter coefficient W0 (n + 1) is calculated according to the following (1).
W0 (n + 1) = W0 (n) -μ ・ e (n) ・ r0 (n) (1)
Here, μ is a step size parameter.

Based on the error signal e (n) output from the microphone 6 and the second simulated reference signal r1 (n) output from the second synthesized signal generator 24, the second adaptive control algorithm calculator 26 calculates the error signal e (n + 1). ) Is sequentially set so that the filter coefficient W1 (n + 1) of the second one-tap adaptive filter 17 is minimized. The filter coefficient W1 is updated based on the LMS algorithm. For example, the filter coefficient W1 (n + 1) is calculated according to the following (2).
W1 (n + 1) = W1 (n) -μ ・ e (n) ・ r1 (n) (2)
The control state detection unit 14 performs arithmetic processing based on the error signal e output from the microphone 6 and controls the phase setting unit 10 based on the result.
The abnormality detection unit 15 performs arithmetic processing based on the output signal from the microphone 6 and controls operation stop or operation continuation of the active noise control device 8 based on the result.

Next, arithmetic processing executed by the control state detection unit 14 will be described with reference to the drawings.
FIG. 3 is a flowchart showing a calculation process executed by the control state detection unit 14.
Note that the arithmetic processing in FIG. 3 is repeatedly executed at a constant cycle.
As shown in FIG. 3, first, in step S101, it is determined whether or not the error signal e output from the microphone 6 is greater than or equal to the first phase switching threshold. The first phase switching threshold value is smaller than a first divergence stop threshold value for determining whether the active noise control device 8 is stopped or continues, and when the active noise control device 8 stops its operation, the microphone 6 Is a specific value set larger than the error signal output. And when it determines with the error signal e being more than a 1st phase switching threshold value (Yes), it transfers to step S103. If it is determined that the error signal e is smaller than the first phase switching threshold (No), the process proceeds to step S102.

FIG. 5 is a diagram showing the axes of the error surface.
If the phase difference between the first reference signal and the second reference signal is 90 degrees, the axis of the error surface can be represented by a sin θ axis and a cos θ axis as shown in FIG.
Further, when the phase difference between the first reference signal and the second reference signal is other than 90 degrees, the sin θ axis of the error surface can be converted into a cos (θ-φ) axis. In this case, in order to generate the same secondary noise immediately after the transformation of the sin θ axis as before the transformation of the sin θ axis, a combined control signal that becomes the source of the secondary noise in accordance with the coordinate transformation of the sin θ axis. It is necessary to correct (a, b) to (c, d). For this reason, when the frequency of converting the sin θ axis to cos (θ−φ) is high, it is necessary to perform signal correction as often as possible, and the calculation load may increase.

Therefore, as the first phase switching threshold, when it is determined that the error signal e is equal to or greater than the first phase switching threshold at the previous execution of this step, a relatively small first set value is used, and the error signal e Is determined to be smaller than the first phase switching threshold, a relatively large second set value is used. When this step is executed for the first time, the second set value is used.
On the other hand, in step S103, a signal for setting the phase correction amount by the phase setting unit 10 to the set value α degrees is output to the phase setting unit 10, and the calculation process is terminated.

Next, calculation processing executed by the abnormality detection unit 15 will be described with reference to the drawings.
FIG. 4 is a flowchart showing a calculation process executed by the abnormality detection unit 15.
Note that the arithmetic processing in FIG. 4 is repeatedly executed at a constant cycle.
As shown in FIG. 4, first, in step 201, it is determined whether or not the error signal e output from the microphone 6 is equal to or greater than the first divergence stop threshold. And when it determines with the error signal e being more than a 1st divergence stop threshold value (Yes), it transfers to step 202. If it is determined that the error signal e is smaller than the first divergence stop threshold (No), the process proceeds to step 203.
In step S202, it is determined that there is an abnormality in the active noise control device 8, the operation of the active noise control device 8 is stopped, and this calculation process is ended.
On the other hand, in step S203, it is determined that the active noise control device 8 is operating normally, the operation of the active noise control device 8 is continued, and this calculation process is terminated.

Next, the relationship between the phase difference between the first reference signal and the second reference signal and the shape of the error surface will be described. The error surface is a curved surface obtained by plotting the relationship between the filter coefficients W0 and W1 of the first and second one-tap adaptive filters and the residual noise.
FIG. 6 is a diagram illustrating the relationship between the phase difference between the first reference signal and the second reference signal and the shape of the error surface when the phase difference is 90 degrees.
FIG. 7 shows the relationship between the phase difference between the first reference signal and the second reference signal and the shape of the error surface when the phase difference is 0 degree or more and less than 90 degrees. FIG.

First, an expression describing the synthesis control signal Y output from the synthesis control signal calculation unit 18 is introduced. When the first reference signal and the second reference signal are both cosine wave signals and the phase difference between the first reference signal and the second reference signal is β, the synthesis control signal Y is expressed by the following equation (3). Can be expressed as:
Y = W0cosθ + W1cos (θ-β) (3)

Here, the following (4) is introduced in order to perform coordinate transformation on a two-dimensional plane having filter coefficients W0 and W1 as axes.
W0 '= W0 + W1
W1 '= W1-W0 ……… (4)
Moreover, said (4) Formula can be put together as the following (5) Formula.
W0 '= (W0 + W1) / 2
W1 '= W1-W0 ……… (5)

Then, by substituting the above equation (5) into the above equation (3), the following equation (6) can be derived.
Y = (W0'-W1 ') cosθ + (W0' + W1 ') cos (θ-β) (6)
Moreover, said (6) Formula can be put together like following (7) Formula.
Y = W0'cos (β / 2) cosθ '+ W1'sin (β / 2) sinθ' ……… （7）
θ '= θ-β / 2
From this equation (7), the synthesis control signal Y should be expressed as the following equation (8) when the phase difference β between the first reference signal and the second reference signal is 90 degrees. Can do.
Y = W0'cosθ '+ W1'sinθ' (8)

Therefore, when a combination of the filter coefficients W0 ′ and W1 ′ that can take a constant composite control signal Y is plotted on a two-dimensional plane having the filter coefficients W0 ′ and W1 ′ as axes, a perfect circle is drawn. Accordingly, as shown in FIG. 6, the contour lines of the error surface become a perfect circle.
Further, when the phase difference β is larger than 0 degree and smaller than 90 degrees, the composition control signal Y can take a constant composition control signal Y on a two-dimensional plane having filter coefficients W0 ′ and W1 ′ as axes. Even if the combination of the filter coefficients W0 ′ and W1 ′ is plotted, it does not become a perfect circle. That is, as shown in FIG. 7, the contour lines of the error surface have an elliptical shape that is a distorted circle.

(Operation)
Next, the operation of the active noise control device of the present embodiment will be described based on a specific situation.
First, in the active noise control device 8, as shown in FIG. 2, the rotational frequency detection device 3 detects an engine pulse signal and outputs the detection result to the first reference signal generation unit 9 and the phase setting unit 10. . Subsequently, the first reference signal generation unit 9 generates a first reference signal synchronized with the engine pulse signal, and outputs the generation result to the first one-tap adaptive filter 16. Subsequently, the first one-tap adaptive filter 16 multiplies the first reference signal by the filter coefficient W0, and outputs the multiplication result to the combined control signal calculation unit 18 as a first control signal.

  Further, the phase setting unit 10 changes the phase of the engine pulse signal output by the rotation frequency detection device 3 by 90 degrees or the set value α, and outputs the change result to the second reference signal generation unit 11. Subsequently, the second reference signal generation unit 11 generates a second reference signal synchronized with the engine pulse signal after the phase change, and outputs the generation result to the second one-tap adaptive filter 17. Subsequently, the second one-tap adaptive filter 17 multiplies the second reference signal by the filter coefficient W1, and outputs the multiplication result to the synthesized control signal calculation unit 18 as a second control signal.

  Then, the synthesis control signal calculation unit 18 synthesizes the first control signal output from the first one-tap adaptive filter 16 and the second control signal output from the second one-tap adaptive filter 17, and the synthesis result Is output to the power amplifier 4 as a combined control signal. Subsequently, the power amplifier 4 amplifies the synthesis control signal and outputs the amplification result to the speaker 5. Subsequently, the speaker 5 generates secondary noise based on the output signal of the power amplifier 4.

At the same time, in the active noise control device 8, the coefficient updating unit 13 uses the first and second taps using the transfer functions C0 and C1 based on the first reference signal, the second reference signal, and the error signal e. The filter coefficients W0 and W1 of the adaptive filters 16 and 17 are updated.
The above is repeated sequentially.
Thereby, the secondary noise at each time can be calculated and controlled. As a result, the secondary noise can be made to interfere with the engine noise and the engine noise can be canceled.

Further, in parallel with the operation of generating the secondary noise from the speaker 5 in this way, in the active noise control device 8, the control state detection unit 14 executes the arithmetic processing of FIG. Here, it is assumed that the error signal e is smaller than the first phase switching threshold. Then, the control state detection unit 14 determines that the error signal e is less than the first phase switching threshold by the arithmetic processing of FIG. 3 (step S101 “No”). Subsequently, the control state detection unit 14 outputs a signal for setting the phase change amount by the phase setting unit 10 to 90 degrees to the phase setting unit 10 (step S102). Then, the phase setting unit 10 sets the change amount of the phase of the engine pulse signal to 90 degrees according to the signal.
Thereby, the phase difference between the first reference signal and the second reference signal can be 90 degrees. Therefore, as shown in FIG. 6, the contour line of the error surface becomes a perfect circle. For this reason, the filter coefficients W0 and W1 can be sequentially updated so that the two filter coefficients W0 and W1 are converged as they gradually approach the optimum point on a two-dimensional plane having the respective axes as the axes.

FIG. 8 is a diagram illustrating the operation of the active noise control device 8.
Here, it is assumed that the error between the transfer functions C0 and C1 and the actual transfer characteristic increases and the convergence of the filter coefficients W0 and W1 is lowered. Then, as shown in FIG. 6, the two filter coefficients W0, W0, W are gradually moved up the error surface while rotating around the optimum point in a two-dimensional plane having the two filter coefficients W0, W1 as axes. Sequentially update W1. As a result, the secondary noise gradually increases. As a result, the secondary noise tends to diverge, and the error signal e gradually increases as shown at time t1 in FIG.

  Further, it is assumed that the error signal e becomes larger than the first phase switching threshold as shown at time t2 in FIG. Then, the control state detection part 14 determines with the error signal e being more than a 1st phase switching threshold value by the arithmetic processing of FIG. 3 (step S101 “Yes”). Subsequently, the control state detection unit 14 outputs to the phase setting unit 10 a signal for setting the phase correction amount by the phase setting unit 10 to a set value α degrees, that is, other than 90 degrees (step S103). Then, as shown at time t2 in FIG. 8B, the phase setting unit 10 sets the amount of change in the phase of the engine pulse signal to other than 90 degrees according to the signal.

  As a result, the phase difference between the first reference signal and the second reference signal can be other than 90 degrees. Therefore, as shown in FIG. 7, the contour lines of the error surface are elliptical. Therefore, the two filter coefficients W0 and W1 can be sequentially updated so that an elliptical trajectory is drawn around the optimum point on a two-dimensional plane having the two filter coefficients W0 and W1 as axes. As a result, when moving from the short side to the long side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 increases, and the divergence tendency of the filter coefficients W0 and W1 increases. As a result, the tendency of divergence of the secondary noise increases, and the increasing tendency of the error signal e, that is, the increasing speed of the error signal e becomes larger as shown at time t2 in FIG.

Further, when moving from the long side to the short side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 decreases, and the divergence tendency of the filter coefficients W0 and W1 decreases. As a result, the tendency of the secondary noise to diverge is reduced, and the error signal e is reduced.
The filter coefficients W0 and W1 circulate around the elliptical trajectory, and the elliptical trajectory is moved alternately from the short side to the long side and from the long side to the short side. The increase and decrease in the output of the secondary noise appear alternately, and the secondary noise beats.

  Further, it is assumed that the error signal e becomes larger than the first divergence stop threshold as shown at time t3 in FIG. Then, the abnormality detection unit 15 determines that the error signal e is equal to or greater than the first divergence stop threshold by the arithmetic processing of FIG. 4 (step S201 “Yes”). Subsequently, the abnormality detection unit 15 stops the operation of the active noise control device 8 (step S202). Then, the speaker 5 stops generating secondary noise.

As a result, when the secondary noise tends to diverge, the generation of the secondary noise can be stopped early. As a result, the time during which the secondary noise that tends to diverge is generated can be shortened, and the secondary noise can be prevented from causing discomfort to the occupant.
In addition, when the secondary noise tends to diverge, it is possible to generate secondary noise with beating. Therefore, it is possible to inform the occupant that there is an abnormality in the active noise control device 8.

FIG. 9 is a diagram for explaining a comparative example.
Incidentally, in the method in which the phase difference between the first reference signal and the second reference signal is not changed to other than 90 degrees, when the filter coefficient diverges, the turning radius gradually increases as shown in FIG. However, the two filter coefficients W0 and W1 are sequentially updated so as to rotate around the optimum point. That is, the distance between the optimum point and the filter coefficients W0 and W1 gradually increases, and the filter coefficients W0 and W1 gradually diverge. As a result, the secondary noise gradually increases, and the error signal e gradually increases as shown in FIG. Therefore, it takes time until the error signal e becomes larger than the first divergence stop threshold and the secondary noise stops. As a result, the generation time of the secondary noise that tends to diverge becomes long, and the secondary noise may cause discomfort to the occupant.

  In the present embodiment, the rotational frequency detection device 3 of FIGS. 1 and 2 constitutes a frequency detection means. Similarly, the first reference signal generator 9 in FIG. 2 constitutes a first reference signal generator. Further, the first one-tap adaptive filter 16 in FIG. 2 constitutes a first one-tap adaptive filter. Further, the second reference signal generation unit 11 in FIG. 2 constitutes a second reference signal generation unit. The second 1-tap adaptive filter 17 in FIG. 2 constitutes a second 1-tap adaptive filter. Further, the synthesis control signal calculation unit 18 of FIG. 2 constitutes a synthesis control signal generation unit. Moreover, the speaker 5 of FIG. 1 and FIG. 2 comprises a secondary noise generating means. Further, the microphone 6 shown in FIGS. 1 and 2 constitutes an error signal detection means. Moreover, the 1st synthetic signal production | generation part 23 and the 2nd synthetic signal production | generation part 24 comprise a simulation reference signal production | generation means. Further, the first adaptive control algorithm calculator 25 and the second adaptive control algorithm calculator 26 of FIG. 2 constitute filter coefficient setting means. Furthermore, the abnormality detection unit 15 in FIG. 2 constitutes a divergence tendency determination unit. Further, the phase setting unit 10 and the control state detection unit 14 in FIG. 2 constitute a phase difference changing unit.

(Effect of this embodiment)
(1) In this embodiment, the divergence tendency determining means has a divergence tendency in secondary noise or secondary vibration based on at least one of an error signal, a combined control signal, a first control signal, and a second control signal. It is determined whether or not there is. Further, the phase difference changing means can change the phase difference between the first reference signal and the second reference signal to a value larger than 0 degree and smaller than 90 degrees.
According to such a configuration, the phase difference between the first reference signal and the second reference signal can be changed to other than 90 degrees. Therefore, the contour lines of the error surface can be made elliptical. Therefore, when there is a sign of a divergence tendency, when the filter coefficient diverges by changing the phase difference to other than 90, around the optimum point on the two-dimensional plane with the two filter coefficients as axes. Are sequentially updated so as to draw an elliptical trajectory. As a result, when the two filter coefficients move from the short side to the long side of the elliptical orbit, the distance between the filter coefficient and the optimum point increases, and the divergence tendency of the filter coefficient increases. The first control signal, the second control signal, the composite control signal, and the error signal increase. Therefore, by making a determination based on these signals, it is possible to detect early that the secondary noise or the secondary vibration has a tendency to diverge.

(2) The divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the error signal is equal to or greater than the first set value. Further, when the phase difference changing means has the error signal equal to or larger than the second setting value smaller than the first setting value, the phase difference between the first reference signal and the second reference signal is larger than 0 degree and larger than 90 degrees. Set to a small value.
According to such a configuration, when the error signal is small, that is, when there is no sign that secondary noise or secondary vibration diverges, the phase difference between the first reference signal and the second reference signal is set to 90 degrees. can do. Therefore, the contour line of the error surface can be made a perfect circle, and the convergence of the filter coefficient can be improved. When the error signal is large, that is, when there is a sign that secondary noise or secondary vibration diverges, the phase difference between the first reference signal and the second reference signal can be other than 90 degrees. Therefore, the contour lines of the error surface can be elliptical, and the error signal can be increased. As a result, it can be detected early that secondary noise or secondary vibration has a tendency to diverge.

(Application examples)
Next, an application example of the active noise control device 8 of the present embodiment will be described with reference to the drawings.
(1) FIG. 10 is a diagram illustrating the operation of the application example. FIG. 10A is a diagram showing a time change of the error signal e, and FIG. 10B is a diagram showing a time change of the phase change amount.
In the present embodiment, the example in which the phase change amount by the phase setting unit 10 is set to the set value α degrees as soon as the error signal e becomes equal to or greater than the first phase switching threshold is shown. However, another configuration is adopted. You can also. For example, as shown in FIG. 10, when changing the phase difference between the first reference signal and the second reference signal, a configuration in which the phase difference is changed stepwise can be used.

  Specifically, when the control state detection unit 14 outputs a signal for changing the phase change amount from 90 degrees to the set value α degree, the phase setting unit 10 first sets the phase change amount of the engine pulse signal to (90 Degree- (90 degrees-setting value α) / 3). Then, the engine pulse signal whose phase has been changed is output to the second reference signal generator 11. Next, after the output of the signal for changing the phase change amount, when the set time elapses, the phase change amount of the engine pulse signal is set to (90 degrees− (90 degrees−setting value α) × 2/3). Next, after the output of the signal for changing the phase change amount, when the time twice as long as the set time elapses, the phase change amount of the engine pulse signal is set to the set value α.

Thus, in this application example, when the phase difference changing unit changes the phase difference between the first reference signal and the second reference signal, the phase difference is changed stepwise.
According to such a configuration, the contour line of the error surface can be gradually changed from a perfect circle to an ellipse. Therefore, it is possible to gradually increase the beat of the secondary noise or the secondary vibration. As a result, control can be performed stably.

(2) FIG. 11 is a diagram illustrating the operation of the application example. FIG. 11A is a diagram showing a time change of the error signal e, and FIG. 11B is a diagram showing a time change of the phase change amount.
For example, as shown in FIG. 11, when changing the phase difference between the first reference signal and the second reference signal, a configuration in which the phase difference is continuously changed can be used.
Specifically, when the control state detection unit 14 outputs a signal for changing the phase change amount from 90 degrees to the set value α degree, the phase setting unit 10 sets the phase change amount of the engine pulse signal from 90 degrees. It is continuously changed at a constant change rate up to the value α. Then, the engine pulse signal whose phase has been changed is output to the second reference signal generator 11.

Thus, in this application example, when the phase difference changing unit changes the phase difference between the first reference signal and the second reference signal, the phase difference is continuously changed.
According to such a configuration, the contour line of the error surface can be gradually changed from a perfect circle to an ellipse. Therefore, it is possible to gradually increase the beat of the secondary noise or the secondary vibration. As a result, control can be performed stably.

(3) FIG. 12 is a conceptual diagram of an apparatus configuration of an application example.
Further, in the present embodiment, the example in which the present invention is applied to an apparatus that generates secondary noise that interferes with engine noise is shown, but the present invention can also be applied to other apparatuses. For example, as shown in FIG. 12, the present invention can also be applied to an apparatus that generates secondary vibration that interferes with engine vibration. As an apparatus that generates such secondary vibration, for example, there is an active engine mount.
In FIG. 12, an active engine mount is provided on each of the left and right sides of the engine 2.
As shown in FIG. 12, the active engine mount includes an engine mount 30 and an error sensor 31 instead of the speaker 5 and the microphone 6.
The engine mount 30 is disposed between the engine foot cross member 32 and the engine 2. The engine mount 30 generates secondary vibration that interferes with engine vibration based on the signal output from the power amplifier 4.

The error sensor 31 is disposed on the engine mount support. Then, the residual vibration generated by the interference with the secondary vibration generated by the engine mount 30 and the engine vibration is detected. The error sensor 31 outputs the detection result to the control device 7 as an error signal e.
According to such a configuration, it is possible to calculate and control the secondary vibration at each time. As a result, it is possible to cause the secondary vibration to interfere with the engine vibration and cancel the engine vibration.
In addition, the apparatus which generate | occur | produces such a secondary vibration which interferes with an engine vibration is not restricted to the technique as described in 1st Embodiment, The technique as described in the 2nd-4th embodiment and its application example mentioned later. The same applies to the above.

(Second Embodiment)
Next, a second embodiment according to the present invention will be described with reference to the drawings.
In addition, about the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.
FIG. 13 is a block diagram showing the contents of the arithmetic processing executed by the control device 7 of the second embodiment.
(Constitution)
The basic configuration of the vehicle of this embodiment is the same as that of the first embodiment. However, as illustrated in FIG. 13, the combined control signal calculation unit 18 outputs the combined control signal to the power amplifier 4 and the abnormality detection unit 15. The abnormality detection unit 15 performs arithmetic processing based on the synthesis control signal output from the synthesis control signal calculation unit 18 instead of the error signal e output from the microphone 6, and based on the result, the phase setting unit 10. To control.

(Operation)
Next, arithmetic processing executed by the control state detection unit 14 will be described with reference to the drawings.
FIG. 14 is a flowchart showing a calculation process executed by the control state detection unit 14.
Note that the arithmetic processing in FIG. 14 is repeatedly executed at a constant cycle.
As shown in FIG. 14, first, in step S301, it is determined whether or not the combined control signal output from the combined control signal calculation unit 18 is equal to or greater than the second phase switching threshold value. The second phase switching threshold is a specific value set to be equal to or less than the second divergence stop threshold for determining whether the active noise control device 8 is stopped or continues. And when it determines with a synthetic | combination signal being more than a 2nd phase switching threshold value (Yes), it transfers to step S303. If it is determined that the combined signal is smaller than the second phase switching threshold (No), the process proceeds to step S302.
In step S302, a signal for setting the phase change amount by the phase setting unit 10 to 90 degrees is output to the phase setting unit 10, and the calculation process is terminated.
On the other hand, in the step S303, a signal for setting the phase correction amount by the phase setting unit 10 to the set value α degree is output to the phase setting unit 10, and the calculation process is ended.

Next, calculation processing executed by the abnormality detection unit 15 will be described with reference to the drawings.
FIG. 15 is a flowchart showing a calculation process executed by the abnormality detection unit 15.
Note that the arithmetic processing in FIG. 15 is repeatedly executed at a constant cycle.
As shown in FIG. 15, first, in step 401, it is determined whether or not the combined control signal output from the combined control signal calculation unit 18 is equal to or greater than the second divergence stop threshold. And when it determines with a synthetic | combination control signal being more than a 2nd divergence stop threshold value (Yes), it transfers to step 402. FIG. On the other hand, if it is determined that the composite control signal is smaller than the second divergence stop threshold (No), the process proceeds to step 403.

In step S402, it is determined that there is an abnormality in the active noise control device 8, the operation of the active noise control device 8 is stopped, and this calculation process is ended.
On the other hand, in step S403, it is determined that the active noise control device 8 is operating normally, the operation of the active noise control device 8 is continued, and the calculation process is terminated.
In the present embodiment, the abnormality detection unit 15 in FIG. 13 constitutes a divergence tendency determination unit. Further, the phase setting unit 10 and the control state detection unit 14 in FIG. 13 constitute a phase difference changing unit.

(Effect of this embodiment)
(1) In the present embodiment, the divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the composite control signal is equal to or greater than the third set value.
According to this configuration, it is possible to determine whether the secondary noise or the secondary vibration has a tendency to diverge based on the combined control signal. Therefore, it is possible to detect earlier that the secondary noise or the secondary vibration has a tendency to diverge as compared with the case where the determination is performed based on the error signal.

(Application examples)
Next, an application example of the active noise control device 8 of the present embodiment will be described with reference to the drawings.
(1) FIG. 16 is a block diagram showing the contents of arithmetic processing executed by the control device 7 of the application example.
In the present embodiment, an example in which the control state detection unit 14 and the abnormality detection unit 15 perform arithmetic processing based on the combined control signal output from the combined control signal calculation unit 18 has been described, but other configurations may be employed. it can. For example, as shown in FIG. 16, a signal level estimation unit 27 that estimates a combined control signal based on a first control signal and a second control signal is provided, and the control state detection unit 14 and the abnormality detection unit 15 perform the estimation. A configuration for performing arithmetic processing based on the result can be used.

Specifically, the signal level estimation unit 27 synthesizes the first control signal output from the first one-tap adaptive filter 16 and the second control signal output from the second one-tap adaptive filter 17. Then, the combination result is output to the control state detection unit 14 and the abnormality detection unit 15 as a combination control signal.
In this application example, the signal level estimation unit 27 in FIG. 16 constitutes a synthesis control signal level estimation unit. Similarly, the abnormality detection unit 15 in FIG. 16 constitutes a divergence tendency determination unit. In addition, the phase setting unit 10 and the control state detection unit 14 in FIG. 16 constitute a phase difference changing unit.

  Thus, in this application example, when the combined control signal estimated by the combined control signal level estimation unit is greater than or equal to the fifth set value, the divergence tendency determination unit has a divergence tendency in the secondary noise or the secondary vibration. I decided to judge. Further, when the phase difference changing unit is equal to or greater than the sixth set value smaller than the fifth set value, the combined control signal estimated by the combined control signal level estimating unit is between the first reference signal and the second reference signal. The phase difference is set to a value larger than 0 degree and smaller than 90 degrees.

As described above, in this application example, the control signal level estimation means estimates the synthesized control signal from the output of the first one-tap adaptive filter and the output of the second one-tap adaptive filter. The divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the estimated combined control signal is equal to or greater than the sixth set value.
According to this configuration, it is possible to determine whether the secondary noise or the secondary vibration has a tendency to diverge based on the estimated combined control signal. Therefore, it is possible to detect earlier that the secondary noise or the secondary vibration has a tendency to diverge as compared with the case where the determination is performed based on the error signal.

(Third embodiment)
Next, a third embodiment according to the present invention will be described with reference to the drawings.
In addition, about the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.
FIG. 17 is a block diagram illustrating the contents of arithmetic processing executed by the control device 7 of the third embodiment.
(Constitution)
The basic configuration of the vehicle of this embodiment is the same as that of the first embodiment. However, a temperature sensor 28 is provided as shown in FIG. Then, the control state detection unit 14 controls the phase setting unit 10 based on the measurement result of the temperature sensor 28.

The temperature sensor 28 is disposed in the vehicle interior. Then, the temperature in the passenger compartment is measured. Further, the temperature sensor 28 outputs the detection result to the control state detection unit 14 as a temperature signal. As the temperature sensor 28, for example, a temperature sensor of an A / C (Air Conditioner) controller that controls the temperature in the passenger compartment by performing cooling or heating can be used.
The control state detection unit 14 performs arithmetic processing based on the temperature signal output from the temperature sensor 28 and controls the operation of the phase setting unit 10 based on the result.

FIG. 18 is a flowchart showing a calculation process executed by the control state detection unit 14.
As shown in FIG. 18, first, in step S501, it is determined whether or not the temperature signal output from the temperature sensor 28 is equal to or greater than a third phase switching threshold value. The third phase switching threshold is the temperature in the passenger compartment when the transfer function H is created, that is, the upper limit value of the temperature at which the transfer function H can simulate the transfer characteristics of the sound field including the position of the microphone 6 from the position of the speaker 5. It is. And when it determines with the temperature signal which the temperature sensor 28 output is more than a 3rd phase switching threshold value (Yes), it transfers to step S503. If it is determined that the temperature signal is smaller than the third phase switching threshold (No), the process proceeds to step S502.
In step S502, a signal for setting the phase change amount by the phase setting unit 10 to 90 degrees is output to the phase setting unit 10, and the calculation process is terminated.
On the other hand, in step S503, a signal for setting the correction amount of the phase by the phase setting unit 10 to the set value α degrees is output to the phase setting unit 10, and the calculation process is terminated.

(Operation)
First, in the active noise control device 8, the control state detection unit 14 executes the arithmetic processing of FIG. Here, it is assumed that the room temperature is lower than the third phase switching threshold. Then, the control state detection unit 14 determines that the room temperature is lower than the third phase switching threshold value by the arithmetic processing of FIG. 8 (step S501 “No”). Subsequently, the control state detection unit 14 outputs a signal for setting the phase change amount by the phase setting unit 10 to 90 degrees to the phase setting unit 10 (step S502). Then, the phase setting unit 10 sets the phase change amount to 90 degrees according to the signal.

FIG. 19 is a diagram illustrating the operation of the active noise control device 8.
Here, the temperature in the passenger compartment increases, and due to this increase in temperature, the error between the transfer functions C0, C1 and the actual transfer characteristics increases, and the convergence of the filter coefficients W0, W1 is reduced. And Then, as shown in FIG. 6, the two filter coefficients W0, W0, W are gradually moved up the error surface while rotating around the optimum point in a two-dimensional plane having the two filter coefficients W0, W1 as axes. Sequentially update W1. As a result, the secondary noise generated by the speaker 5 gradually increases. As a result, the secondary noise tends to diverge, and the error signal e gradually increases as shown at time t1 in FIG.

  Further, it is assumed that the temperature signal becomes larger than the third phase switching threshold as shown at time t2 in FIG. Then, the control state detection part 14 determines with a temperature signal being more than a 3rd phase switching threshold value by the arithmetic processing of FIG. 18 (step S501 “Yes”). Subsequently, the control state detection unit 14 outputs a signal for setting the phase correction amount by the phase setting unit 10 to a setting value α degrees, that is, other than 90 degrees, to the phase setting unit 10 (step S503). Then, as shown at time t2 in FIG. 19C, the phase setting unit 10 changes the phase change amount of the engine pulse signal to other than 90 degrees according to the signal.

  As a result, the phase difference between the first reference signal and the second reference signal can be other than 90 degrees. Therefore, as shown in FIG. 7, the contour lines of the error surface are elliptical. Therefore, the two filter coefficients W0 and W1 can be sequentially updated so that an elliptical trajectory is drawn around the optimum point on a two-dimensional plane having the two filter coefficients W0 and W1 as axes. As a result, when moving from the short side to the long side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 increases, and the divergence tendency of the filter coefficients W0 and W1 increases. As a result, the divergence tendency of the secondary noise increases, and the increase tendency of the error signal e, that is, the increase speed of the error signal e becomes larger as shown at time t2 in FIG.

Further, when moving from the long side to the short side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 decreases, and the divergence tendency of the filter coefficients W0 and W1 decreases. As a result, the tendency of the secondary noise to diverge is reduced, and the error signal e is reduced.
The filter coefficients W0 and W1 circulate around the elliptical trajectory, and the elliptical trajectory is moved alternately from the short side to the long side and from the long side to the short side. The increase and decrease in the output of the secondary noise appear alternately, and the secondary noise beats.

  Further, it is assumed that the error signal e becomes larger than the first divergence stop threshold as shown at time t3 in FIG. Then, the abnormality detection unit 15 determines that the error signal e is equal to or greater than the first divergence stop threshold by the arithmetic processing of FIG. 4 (step S201 “Yes”). Subsequently, the abnormality detection unit 15 stops the operation of the active noise control device 8 (step S202). Then, the speaker 5 stops generating secondary noise.

As a result, when the secondary noise tends to diverge, the generation of the secondary noise can be stopped early. As a result, the time during which the secondary noise that tends to diverge is generated can be shortened, and the secondary noise can be prevented from causing discomfort to the occupant.
In addition, when the secondary noise tends to diverge, it is possible to generate secondary noise with beating. Therefore, it is possible to inform the occupant that there is an abnormality in the active noise control device 8.
In the present embodiment, the temperature sensor 28 of FIG. 17 constitutes a temperature detection means. Similarly, the phase setting unit 10 and the control state detection unit 14 in FIG. 17 constitute a phase difference changing unit.

(Effect of this embodiment)
(1) In the present embodiment, when the temperature detected by the temperature detecting means is smaller than the seventh set value, the phase difference changing means sets the phase difference between the first reference signal and the second reference signal from 0 degrees. The value was set to be larger than 90 degrees.
According to such a configuration, the phase difference between the primary reference signal and the secondary reference signal can be set based on the vehicle temperature. Therefore, when it is expected that the error between the transfer function and the actual transfer characteristic is increased when the transfer function is generated, the primary reference signal and the secondary reference signal are changed. The phase difference between can be other than 90 degrees. As a result, when the transfer function changes due to the temperature change of the vehicle and a divergence tendency occurs in the secondary noise or the secondary vibration, the divergence tendency can be detected at an early stage.

(2) The temperature detecting means measures the temperature in the passenger compartment.
According to such a configuration, the phase difference between the primary reference signal and the secondary reference signal can be set based on the temperature in the passenger compartment. Therefore, when it is expected that the error between the transfer function and the actual transfer characteristic is increased when the transfer function is generated, the primary reference signal and the secondary reference signal are changed. The phase difference between can be other than 90 degrees. As a result, when the transfer function changes due to a temperature change in the passenger compartment and a divergence tendency occurs in the secondary noise or the secondary vibration, the divergence tendency can be detected early.
(3) Further, a temperature sensor of an A / C controller was used as the temperature detecting means.
According to such a structure, the A / C controller normally mounted in the vehicle can be used as the temperature detection means. Therefore, the manufacturing cost can be reduced.

(Application examples)
Next, an application example of the active noise control device 8 of the present embodiment will be described with reference to the drawings.
(1) In the present embodiment, an example in which the temperature sensor of an A / C controller that measures the temperature in the passenger compartment is used as the temperature sensor is shown, but other configurations may be employed. For example, a sensor that measures the temperature in the vicinity of the microphone 6 may be used as the temperature sensor 28.
The microphone 6 is arranged in the room trif. Since the roof trim is easily affected by solar radiation, the temperature rise is higher than other places in the passenger compartment. Therefore, there may be a case where there is no correlation between the temperature in other places in the vehicle interior and the temperature in the vicinity of the microphone 6. Therefore, by detecting the temperature in the vicinity of the microphone 6, the transfer function changes due to the temperature change in the vicinity of the microphone 6 as compared with the case of detecting the temperature in other places, and secondary noise or secondary vibration is detected. When a divergence tendency occurs, the divergence tendency can be detected early.

(2) Also, for example, a temperature sensor that measures the outside air temperature can be used.
In this application example, the temperature detection means detects the temperature outside the passenger compartment.
According to this structure, the temperature sensor for measuring the outside temperature normally mounted in the vehicle can be used as the temperature detection means. Therefore, the manufacturing cost can be reduced.

(Fourth embodiment)
Next, a fourth embodiment according to the present invention will be described with reference to the drawings.
In addition, about the structure similar to the said 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.
FIG. 20 is a block diagram illustrating the contents of arithmetic processing executed by the control device 7 of the fourth embodiment.
(Constitution)
The basic configuration of the vehicle of this embodiment is the same as that of the first embodiment. However, as shown in FIG. 20, a window opening / closing detection sensor 29 is provided. Then, the control state detection unit 14 controls the phase setting unit 10 based on the measurement result of the window opening sensor 29.
The window opening / closing detection sensor 29 detects whether the vehicle window and the sunroof are opened. Then, the detection result is output to the control state detection unit 14 as an open signal.
The control state detection unit 14 performs arithmetic processing based on the opening signal output from the window opening / closing detection sensor 29, and controls the operation of the phase setting unit 10 based on the result.

FIG. 21 is a flowchart showing a calculation process executed by the control state detection unit 14.
As shown in FIG. 21, first, in step S601, based on the opening signal output from the window opening / closing detection sensor 29, it is determined whether at least one of the vehicle window and the sunroof is open. If it is determined that at least one of the vehicle window and the sunroof is open (Yes), the process proceeds to step S603. If it is determined that both the vehicle window and the sunroof are closed (No), the process proceeds to step S602.

In step S602, a signal for changing the phase change amount by the phase setting unit 10 to 90 degrees is output to the phase setting unit 10, and the calculation process is terminated.
On the other hand, in step S603, a signal for setting the phase correction amount by the phase setting unit 10 to the set value α degrees is output to the phase setting unit 10, and the calculation process is terminated.
In the present embodiment, the window opening / closing detection sensor 29 of FIG. 20 constitutes a temperature detection means. Similarly, the phase setting unit 10 and the control state detection unit 14 in FIG. 20 constitute a phase difference changing unit.

(Operation)
First, in the active noise control device 8, the control state detection unit 14 executes the arithmetic processing of FIG. Here, it is assumed that both the vehicle window and the sunroof are closed. Then, the control state detection unit 14 determines that both the vehicle window and the sunroof are closed by the arithmetic processing of FIG. 21 (step S601 “No”). Subsequently, the control state detection unit 14 outputs a signal for setting the phase change amount by the phase setting unit 10 to 90 degrees to the phase setting unit 10 (step S602). Then, the phase setting unit 10 sets the phase change amount to 90 degrees according to the signal.

FIG. 22 is a diagram illustrating the operation of the active noise control device 8.
Here, it is assumed that the error between the transfer functions C0 and C1 and the actual transfer characteristic increases and the convergence of the filter coefficients W0 and W1 is lowered. Then, as shown in FIG. 6, the two filter coefficients W0, W0, W are gradually moved up the error surface while rotating around the optimum point in a two-dimensional plane having the two filter coefficients W0, W1 as axes. Sequentially update W1. As a result, the secondary noise gradually increases. As a result, the secondary noise tends to diverge, and the error signal e gradually increases as shown at time t1 in FIG.

  Further, as shown at time t2 in FIG. 22B, it is assumed that the occupant opens the vehicle window. Then, the control state detection part 14 determines with the window of a vehicle being open by the arithmetic processing of FIG. 21 (step S601 "Yes"). Subsequently, the control state detection unit 14 outputs a signal for setting the phase correction amount by the phase setting unit 10 to a setting value α degrees, that is, other than 90 degrees, to the phase setting unit 10 (step S603). Then, as shown at time t2 in FIG. 22 (c), the phase setting unit 10 changes the phase change amount of the engine pulse signal to other than 90 degrees according to the signal.

  As a result, the phase difference between the first reference signal and the second reference signal can be other than 90 degrees. Therefore, as shown in FIG. 7, the contour lines of the error surface are elliptical. Therefore, the two filter coefficients W0 and W1 can be sequentially updated so that an elliptical trajectory is drawn around the optimum point on a two-dimensional plane having the two filter coefficients W0 and W1 as axes. As a result, when moving from the short side to the long side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 increases, and the divergence tendency of the filter coefficients W0 and W1 increases. As a result, the tendency of divergence of the secondary noise increases, and the increasing tendency of the error signal e, that is, the increasing speed of the error signal e becomes larger as shown at time t2 in FIG.

Further, when moving from the long side to the short side of the elliptical orbit, the distance between the optimum point and the filter coefficients W0 and W1 decreases, and the divergence tendency of the filter coefficients W0 and W1 decreases. As a result, the tendency of the secondary noise to diverge is reduced, and the error signal e is reduced.
The filter coefficients W0 and W1 circulate around the elliptical trajectory, and the elliptical trajectory is moved alternately from the short side to the long side and from the long side to the short side. The increase and decrease in the output of the secondary noise appear alternately, and the secondary noise beats.

  Further, it is assumed that the error signal e becomes larger than the first divergence stop threshold as shown at time t3 in FIG. Then, the abnormality detection unit 15 determines that the error signal e is greater than or equal to the first divergence stop threshold by the arithmetic processing of FIG. 4 (step S201 “Yes”). Subsequently, the abnormality detection unit 15 stops the operation of the active noise control device 8 (step S202). Then, the speaker 5 stops generating secondary noise.

As a result, when the secondary noise tends to diverge, the generation of the secondary noise can be stopped early. As a result, the time during which the secondary noise that tends to diverge is generated can be shortened, and the secondary noise can be prevented from causing discomfort to the occupant.
In addition, when the secondary noise tends to diverge, it is possible to generate secondary noise with beating. Therefore, it is possible to inform the occupant that there is an abnormality in the active noise control device 8.

(Effect of this embodiment)
(1) In the present embodiment, the phase difference changing means calculates the phase difference between the first reference signal and the second reference signal when the open / close detection means detects the opening of at least one of the vehicle window and the sunroof. The value is larger than 0 degree and smaller than 90 degrees.
According to such a configuration, the phase difference between the primary reference signal and the secondary reference signal can be set based on the open / closed state of at least one of the vehicle window and the sunroof. Therefore, when the error between the transfer function and the actual transfer characteristic is expected to increase, unlike the open state of the window and sunroof assumed when the transfer function is generated, the primary reference signal and 2 The phase difference from the next reference signal can be other than 90 degrees. As a result, when the transfer function changes due to a change in the open state of the window and the sunroof, and a divergence tendency occurs in the secondary noise or the secondary vibration, the divergence tendency can be detected early.

1 is a vehicle, 2 is an engine (vibration source), 3 is a rotation frequency detection device (frequency detection means), 5 is a speaker (secondary noise vibration generation means), 6 is a microphone (error signal detection means), and 9 is a first. Reference signal generation unit (first reference signal generation unit), 10 is a phase setting unit (phase setting unit), 11 is a second reference signal generation unit (second reference signal generation unit), and 14 is a control state detection unit (phase setting unit). Means), 15 is an anomaly detector (divergence tendency determining means), 16 is a first one-tap adaptive filter (first one-tap adaptive filter), and 17 is a second one-tap adaptive filter (second one-tap adaptive). Filter), 18 is a synthesis control signal calculation unit (synthesis control signal generating means), 19 is a first transfer element (transfer function), 20 is a second transfer element (transfer function), and 21 is a third transfer element (transfer function). , 22 is the fourth transfer element (transfer function) 23 is a first synthesized signal generator (simulated reference signal generator), 24 is a second synthesized signal generator (simulated reference signal generator), 25 is a first adaptive control algorithm calculator (filter coefficient setting unit), and 26 is Second adaptive control algorithm computing unit (filter coefficient setting means), 27 is a signal level estimation unit (control signal level estimation means), 28 is a temperature sensor (temperature detection means), 29 is a window open / close detection sensor (open / close detection means), First divergence stop threshold (first set value), first phase switch threshold (second set value), second phase switch threshold (third set value, fifth set value), second divergence stop threshold (fourth set) Value, sixth set value), third phase switching threshold (seventh set value), third divergence stop threshold (eighth set value)

Claims (13)

Frequency detection means for detecting the frequency of noise or vibration having periodicity generated by a vibration source;
First reference signal generation means for generating a first reference signal synchronized with the frequency detected by the frequency detection means;
A first one-tap adaptive filter that generates a first control signal based on the first reference signal generated by the first reference signal generator;
Second reference signal generating means for generating a second reference signal synchronized with the frequency detected by the frequency detecting means and having a phase difference of 90 degrees with the first reference signal;
A second one-tap adaptive filter that generates a second control signal based on the second reference signal generated by the second reference signal generator;
Combined control signal generating means for generating a combined control signal by combining the first control signal generated by the first 1-tap adaptive filter and the second control signal generated by the second 1-tap adaptive filter;
Secondary noise vibration generating means for generating secondary noise that interferes with the noise or secondary vibration that interferes with the vibration based on the combined control signal generated by the combined control signal generating means;
Error signal detection means for detecting an error signal based on residual noise generated by interference between the noise and the secondary noise, or residual vibration generated by interference between the vibration and the secondary vibration;
Based on the first reference signal and the second reference signal, a first simulation reference signal and a second simulation are generated using a transfer function that simulates a transfer characteristic from the secondary noise vibration generating means to the error signal detecting means. Simulated reference signal generating means for generating a reference signal;
Based on the first simulation reference signal and the second simulation reference signal generated by the simulation reference signal generation means and the error signal detected by the error signal detection means, the first 1 Filter coefficient setting means for sequentially setting a filter coefficient of a tap adaptive filter and a filter coefficient of the second one-tap adaptive filter;
At least one of an error signal detected by the error signal detection unit, a synthesis control signal generated by the synthesis control signal control unit, an output of the first one-tap adaptive filter, and an output of the second one-tap adaptive filter Based on the divergence tendency determination means for determining whether the secondary noise or the secondary vibration has a divergence tendency;
An active noise vibration control device comprising: phase difference changing means for changing a phase difference between the first reference signal and the second reference signal to a value larger than 0 degree and smaller than 90 degrees.   2. The active type according to claim 1, wherein the phase difference changing unit changes the phase difference stepwise when changing the phase difference between the first reference signal and the second reference signal. Noise vibration control device.   2. The active type according to claim 1, wherein when the phase difference between the first reference signal and the second reference signal is changed, the phase difference changing unit continuously changes the phase difference. Noise vibration control device. The divergence tendency determination means determines that the secondary noise or the secondary vibration has a divergence tendency when the error signal detected by the error signal detection means is equal to or greater than a first set value.
The phase difference changing unit is provided between the first reference signal and the second reference signal when the error signal detected by the error signal detecting unit is equal to or larger than a second set value that is smaller than the first set value. 2. The active noise vibration control device according to claim 1, wherein the phase difference is changed to a value larger than 0 degree and smaller than 90 degrees. The divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the synthesized control signal generated by the synthesized control signal control means is equal to or greater than a third set value;
The phase difference changing unit is configured to output the first reference signal and the second reference signal when the synthesis control signal generated by the synthesis control signal control unit is equal to or greater than a fourth setting value that is smaller than the third setting value. 2. The active noise vibration control device according to claim 1, wherein the phase difference between them is changed to a value larger than 0 degree and smaller than 90 degrees. Control signal level estimation means for estimating the combined control signal from the output of the first one-tap adaptive filter and the output of the second one-tap adaptive filter;
The divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the combined control signal output by the combined control signal level estimation means is equal to or greater than a fifth set value;
The phase difference changing unit is configured to output the first reference signal, the second reference signal, and the second reference signal when the combined control signal output from the combined control signal level estimation unit is equal to or greater than a sixth set value that is smaller than the fifth set value. The active noise vibration control apparatus according to claim 1, wherein the phase difference between the two is changed to a value larger than 0 degree and smaller than 90 degrees. The active noise vibration control device according to any one of claims 1 to 3, configured for mounting on a vehicle,
Temperature detecting means for detecting the temperature of the vehicle,
The divergence tendency determining means determines that the secondary noise or the secondary vibration has a divergence tendency when the error signal detected by the error signal detection means is a seventh set value or more,
The phase difference changing means increases the phase difference between the first reference signal and the second reference signal to greater than 0 degrees and 90 degrees when the temperature detected by the temperature detection means is equal to or higher than an eighth set value. An active noise / vibration control device for a vehicle characterized by changing to a smaller value.   The vehicle active vibration control device according to claim 7, wherein the temperature detection unit measures a temperature in the vehicle interior.   The vehicle active noise vibration control device according to claim 7, wherein the temperature detection unit measures a temperature in the vicinity of the error signal detection unit.   8. The active noise / vibration control device for a vehicle according to claim 7, wherein the temperature detecting means is a temperature sensor of an A / C controller. An active noise and vibration control device according to any one of claims 1 to 3 configured for mounting on a vehicle;
Temperature detecting means for detecting the temperature outside the passenger compartment,
The divergence tendency determination means determines that the secondary noise or the secondary vibration has a divergence tendency when the error signal detected by the error signal detection means is a seventh set value or more,
The phase difference changing means increases the phase difference between the first reference signal and the second reference signal to greater than 0 degrees and 90 degrees when the temperature detected by the temperature detection means is equal to or higher than an eighth set value. An active noise / vibration control device for a vehicle characterized by changing to a smaller value. An active noise and vibration control device according to any one of claims 1 to 3 configured for mounting on a vehicle;
Open / close detecting means for detecting whether the vehicle window and sunroof are open,
The divergence tendency determination means determines that the secondary noise or the secondary vibration has a divergence tendency when the error signal detected by the error signal detection means is equal to or greater than a first set value.
The phase difference changing means sets the phase difference between the first reference signal and the second reference signal from 0 degrees when the open / close detection means detects the opening of at least one of a vehicle window and a sunroof. An active noise and vibration control device for a vehicle, characterized in that the value is changed to a value less than 90 degrees. A frequency detecting step for detecting a frequency of noise or vibration having periodicity generated by the vibration source;
A first reference signal generation step for generating a first reference signal synchronized with the frequency detected in the frequency detection step;
A first control signal generating step of generating a first control signal by multiplying the first reference signal generated in the first reference signal generating step by a filter coefficient of a first one-tap adaptive filter;
A second reference signal generation step for generating a second reference signal that is synchronized with the frequency detected in the frequency detection step and has a phase difference of 90 degrees with the first reference signal;
A second control signal generating step of generating a second control signal by multiplying the second reference signal generated in the second reference signal generating step by a filter coefficient of a second one-tap adaptive filter;
A combined control signal generating step for generating a combined control signal by combining the first control signal generated in the first control signal generating step and the second control signal generated in the second control signal generating step;
A secondary noise vibration generating step for generating a secondary noise that interferes with the noise or a secondary vibration that interferes with the vibration by a secondary noise vibration generating means based on the combined control signal generated in the combined control signal generating step; ,
An error signal detection step of detecting an error signal by error signal detection means based on residual noise generated by interference between the noise and the secondary noise, or residual vibration generated by interference between the vibration and the secondary vibration;
Based on the first reference signal and the second reference signal, a first simulation reference signal and a second simulation are generated using a transfer function that simulates a transfer characteristic from the secondary noise vibration generating means to the error signal detecting means. A simulated reference signal generation step for generating a reference signal;
Based on the first simulation reference signal and the second simulation reference signal generated in the simulation reference signal generation step, and the error signal detected in the error signal detection step, the first 1 is set so that the error signal is minimized. A filter coefficient setting step for sequentially setting a filter coefficient of a tap adaptive filter and a filter coefficient of the second one-tap adaptive filter;
The error signal detected in the error signal detection step, the synthesis control signal generated in the synthesis control signal control step, the first control signal generated in the first control signal generation step, and the second control signal generation step A divergence tendency determination step for determining whether the secondary noise or the secondary vibration has a divergence tendency based on at least one of the second control signals;
And a phase difference changing step of changing a phase difference between the first reference signal and the second reference signal to a value larger than 0 degree and smaller than 90 degrees. .

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