JP3419231B2 - Active vibration control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention transmits a vibration to a support body by interfering with a vibration generated by a vibration body such as a vehicle engine, a control vibration generated by a control vibration source interposed between the vibration body and the support body. The present invention relates to an active vibration control device for reducing the vibrations generated, particularly in a control algorithm for driving a controlled vibration source that includes a transfer function between the controlled vibration source and a means for detecting residual vibration, It is intended to reduce energy consumption when identifying the transfer function.

[0002]

2. Description of the Related Art In the case of an active vibration control device such as the present invention, the transfer function between the control vibration source and the means for detecting residual vibration is determined by the device to which the active vibration control device is applied and the equipment to which it is applied. Since it varies slightly depending on the characteristic variation for each, and it may change from the initial state due to the characteristic change accompanying the use of the target device, etc. It is desirable to identify the transfer function after incorporating the active vibration control device into the application target device, or to identify the transfer function for each periodic inspection of the application target device.

Therefore, the applicant of the present invention previously disclosed in Japanese Patent Laid-Open No. 6-33.
A technique disclosed in Japanese Patent No. 2471 is proposed. That is, the conventional technique disclosed in this publication generates an identification sound or an identification vibration corresponding to an impulse signal from a control sound source or a control vibration source, and measures the response by means for detecting residual noise or residual vibration. , The transfer function necessary for the control algorithm of the active noise control device or the active vibration control device is identified. Then, by limiting the timing of generating the identification sound or the identification signal according to the impulse signal, just before transitioning to the state where noise or vibration does not occur from the noise source or the vibration source,
It has been possible to identify the transfer function without causing a large increase in the calculation load and without causing discomfort to humans or the like.

As another prior art, although it is not related to vibration reduction but to noise reduction technology,
There is one disclosed in Japanese Patent Laid-Open No. 3-259722. The device disclosed in this publication is a device for canceling noise generated in a compressor of a refrigerator and radiated to the outside through a machine room duct before being radiated from the machine room duct. It is equipped with a loudspeaker and a microphone to perform noise reduction by generating a control sound from the loudspeaker according to the driving state of the compressor, while preventing noise from degrading the noise control characteristics. The identification sound is generated according to the noise signal, the transfer function between the loudspeaker and the microphone is measured, and the filter is identified.

[0005]

Certainly, according to the prior art as described above, it is necessary to identify the transfer function required for control for each device to which the active vibration control device or the active noise control device is applied. Therefore, highly accurate vibration reduction control and the like can be expected.

On the other hand, in order to identify the transfer function in the above-mentioned prior art, it is necessary to generate an identification sound corresponding to the impulse signal or the white noise signal.
Since the impulse signal and the white noise signal are signals including components in the entire frequency band, even if the identification sound is generated, the output is dispersed in a wide frequency band. Then, unless the total output of the identification sound is made sufficiently high, the output for each frequency component becomes small and the identification of the transfer function becomes insufficient. Therefore, there is a demand that the identification sound must be generated with a high output so that the output for each frequency component can be sufficiently obtained.

[0007] For such a demand, for example, an active noise control device using a loudspeaker as a control sound source can easily be applied to a loudspeaker capable of large output as long as a space can be secured. It can be achieved relatively easily.

However, for example, the vibration transmitted from the vehicle engine to the vehicle body is reduced by generating an active supporting force by the engine mount disposed between the engine and the vehicle body. In the case of the vibration control device, there is a limit to the active supporting force that can be generated by the engine mount. Therefore, even if a large impulse signal or white noise signal is supplied to the engine mount as the control vibration source, the level of the identification sound that actually occurs is not so high, and as it is, it takes a long time to identify the transfer function. Will end up.

Further, in actual vibration reduction control such as when the vehicle engine is a vibration source, vibrations such as white noise over the entire frequency band do not occur, but at a specific frequency. Since concentrated vibration is generally generated, it may not be possible to identify a transfer function suitable for an actual use condition with an identification sound such as a white noise signal.

Further, considering the situation in which the transfer function is actually identified, for example, in the case of an active vibration control device for a vehicle, the transfer function for each vehicle equipped with the active vibration control device is on the factory line. In order to identify, the control vibration source must be driven by the battery mounted on the vehicle to identify the transfer function. Therefore, there is a demand to reduce the power consumption for identifying the transfer function as much as possible.

The present invention has been made by paying attention to the unsolved problem of the conventional technique as described above, and the transmission of the transfer function without adversely affecting the identification accuracy of the transfer function required for the vibration reduction control. It is an object of the present invention to provide an active vibration control device capable of reducing energy consumption when identifying a function.

[0012]

In order to achieve the above object, the invention according to claim 1 provides a control vibration source interposed between a vibrating body and a support body to generate control vibration, and a vibration of the vibrating body. Reference signal generating means for detecting the generation state and outputting it as a reference signal, residual vibration detecting means for detecting the residual vibration on the side of the support and outputting it as a residual vibration signal, and the control vibration based on the reference signal and the residual vibration signal. An active control means for driving the controlled vibration source so that the vibration is reduced by using a control algorithm including a transfer function between the source and the residual vibration detection means, and the controlled vibration source controls the controlled vibration. In an active vibration control device having a fluid resonance system for generating, an identification signal supply means for supplying a sinusoidal identification signal to the controlled vibration source by sequentially changing its frequency, Response signal reading means for reading the residual vibration signal when vibration according to a constant signal is emitted from the controlled vibration source, and identifying the transfer function based on the residual vibration signal read by the response signal reading means. The transfer function identifying means and the amplitude setting means for setting the amplitude of the identification signal such that the frequency of the identification signal is small for an identification signal whose frequency is far from the resonance frequency of the fluid resonance system.

According to a second aspect of the present invention, in the active vibration control device according to the first aspect of the present invention, the amplitude setting means sets the amplitude of the identification signal whose frequency is equal to the resonance frequency of the fluid resonance system. The amplitude of the identification signal, which is set to be large and whose frequency is far from the resonance frequency of the fluid resonance system, is set to be small.

According to a third aspect of the present invention, in the active vibration control device according to the first aspect of the present invention, the amplitude setting means sets the identification signal whose frequency is equal to the resonance frequency of the fluid resonance system. The amplitude is set to a predetermined amplitude that matches the amplitude of the drive signal supplied to the controlled vibration source by the active control unit when the frequency of the vibration generated in the vibrating body is equal to the resonance frequency, and the frequency is set to the fluid. The amplitude of the identification signal is gradually reduced with increasing distance from the resonance frequency of the resonance system.

According to a fourth aspect of the present invention, in the active vibration control device according to the first aspect of the present invention, the amplitude setting means determines the amplitude of the identification signal with respect to its frequency and the fluid resonance system. For the identification signal whose difference from the resonance frequency is less than a predetermined threshold value, the drive signal supplied to the controlled vibration source by the active control means when the frequency of the vibration generated in the vibrating body is equal to the resonance frequency. Is set to a predetermined amplitude that matches the amplitude of, and for an identification signal in which the difference between the frequency and the resonance frequency of the fluid resonance system is equal to or greater than the threshold value, the amplitude is set to be smaller than the predetermined amplitude. It has become.

Further, the invention according to claim 5 is the active vibration control device according to any one of claims 1 to 4, wherein the transfer function identifying means is the residual vibration signal read by the response signal reading means. Fourier transform means for performing Fourier transform on each of the identification signals to extract a component corresponding to the frequency of the identification signal, and correction means for correcting each frequency component extracted by the Fourier transform means with the amplitude of each identification signal, And an inverse Fourier transform means for obtaining an impulse response as the transfer function by performing an inverse Fourier transform on a combination of the results of the correction means.

The invention according to claim 6 is the active vibration control device according to any one of claims 1 to 5, wherein:
The control vibration source includes a supporting elastic body interposed between the vibrating body and the supporting body, a main fluid chamber defined by the supporting elastic body, and a variable volume auxiliary sub-unit communicating with the main fluid chamber via an orifice. A fluid chamber, a fluid enclosed in the main fluid chamber, the sub-fluid chamber, and an orifice, a movable member forming a part of a partition wall of the main fluid chamber, and the movable member changing the volume of the main fluid chamber. An actuator for displacing the fluid in the direction of movement, and the fluid resonance system is configured by an expansion direction spring of a partition wall that defines the main fluid chamber and a sub fluid chamber, and a fluid in the orifice. .

According to a seventh aspect of the present invention, in the active vibration control device according to the first to sixth aspects of the invention, the active control means includes an adaptive digital filter having a variable filter coefficient and the reference signal. Driving signal generating means for generating and outputting a driving signal for driving the controlled vibration source by filtering with the adaptive digital filter, and an update reference signal which is a response result when the reference signal is input to the transfer function. Update reference signal calculation means for calculating, and a filter coefficient update means for updating the filter coefficient of the adaptive digital filter according to the successive update type adaptive algorithm as the control algorithm based on the residual vibration signal and the update reference signal. Equipped with.

Further, the invention according to claim 8 is the one in which the active vibration control device according to any one of claims 1 to 7 is applied to a vehicle and the vibrating body is an engine. The resonance frequency of the resonance system was adjusted near the idle vibration frequency.

Further, the invention according to claim 9 is the one in which the active vibration control device according to any one of claims 1 to 7 is applied to a vehicle, and the vibrating body is an engine. The resonance frequency of the fluid resonance system was adjusted to a frequency slightly lower than the idle vibration frequency.

Here, in the invention according to claim 1,
Since the sinusoidal identification signal is supplied from the identification signal supply means to the control vibration source, the vibration (identification vibration) emitted from the control vibration source in response to the identification signal is a vibration that changes in a sinusoidal shape. Then, the frequency component of the identified vibration concentrates on the specific frequency corresponding to the frequency of the original sine wave, so even if there is a limit to the active bearing force that can be generated by the controlled vibration source, the response signal reading The residual vibration signal of a relatively high level can be read by the means, and the frequency of the identification signal is sequentially changed. Therefore, the transfer function identification means identifies the transfer function effective over a wide frequency band with high accuracy. be able to.

If the frequency component of the identified vibration is concentrated on the specific frequency, the residual vibration signal that needs to be read by the response signal reading means corresponds to the length required on the time axis as the transfer function (impulse response). Since it suffices to capture only the amount, the time during which the identification vibration is generated can be shorter than that in the case of identification by the white noise signal. In other words, in order to perform the identification calculation using the white noise signal, it is necessary to capture the identification vibration as the residual vibration signal while performing the adaptive calculation to identify the transfer function, so that the transfer function is identified with high accuracy. In order to achieve this, it is necessary to continue to generate the identification vibration for as long as possible. However, as in the invention according to claim 1, as long as it is configured to generate the sinusoidal identification vibration, it is included in the residual vibration signal. Of the frequency components to be identified, the level and phase of the component corresponding to the frequency of the sine wave that is the source of the identification signal need only be comprehended by, for example, Fourier transform processing, etc. After all, the time will be the time spent to acquire the required number of data, and it will be shorter than when the transfer function is identified by the white noise signal. That.

If the frequency component of the identification vibration is concentrated on the specific frequency, the calculation processing in the transfer function identification means can be performed with a relatively small calculation load such as Fourier transform or inverse Fourier transform. The processing is simpler than the case of identification by a noise signal, and the required controller also has relatively low capability.

Further, in the invention according to the first aspect, the control vibration source for generating the control vibration has the fluid resonance system in which the reciprocating motion of the fluid is generated when the control vibration is generated. The amplitude dependency of the fluid greatly affects the vibration generated by the controlled vibration source.

Therefore, at a frequency with a large amplitude dependence,
If the amplitude of the identification signal is small (the amplitude of the identification vibration is small), the spring constant becomes large, and if the amplitude of the identification signal is large (the amplitude of the identification vibration is large), the spring constant becomes small. The characteristics of the controlled vibration source differ greatly. Therefore, when the frequency of the identification signal has a large frequency dependence, it is effective for the vibration reduction control unless the identification vibration of the same magnitude as the control vibration generated when executing the vibration reduction control is generated. It is not possible to identify a specific transfer function.

On the other hand, at a frequency with a small amplitude dependence, the magnitude of the amplitude of the identification vibration does not significantly affect the characteristics of the controlled vibration source. Moreover, the energy consumption for generating the identification vibration decreases as the amplitude of the identification vibration decreases, and the amplitude of the identification vibration is proportional to the amplitude of the identification signal.

The amplitude dependency is large at the resonance frequency of the fluid resonance system and its vicinity, and becomes smaller as the distance from the resonance frequency increases. From the above, by the amplitude setting means, if the amplitude of the identification signal is set to be small for the identification signal whose frequency is far from the resonance frequency of the fluid resonance system, without degrading the identification accuracy of the transfer function, It is possible to reduce energy consumption when generating the identification vibration.

The level of control vibration generated when executing the vibration reduction control is often near the maximum level that can be generated by the control vibration source. This is because it is difficult to actually use a large-scale, large-capacity controlled vibration source that can generate a controlled vibration at exactly the same level as the vibration generated by the vibrating body, due to the installation space, cost, etc. This is because there is no choice but to use a small-sized, small-capacity controlled vibration source and use it at maximum output. Therefore,
When the amplitude setting means sets the amplitude of the identification signal as in the invention according to claim 2, the operation of the invention according to claim 1 can be more reliably exhibited.

And, in the invention according to claim 3,
The amplitude setting means causes the amplitude of the identification signal to gradually change. That is, the amplitude of the identification signal is set to the maximum predetermined amplitude where the frequency is equal to the resonance frequency of the fluid resonance system, and gradually decreases as the frequency deviates from the resonance frequency of the fluid resonance system. Therefore, the amplitude of the identification signal changes in accordance with the magnitude of the amplitude dependence of the fluid, so that the action of the invention according to claim 1 can be more reliably exhibited.

On the other hand, in the invention according to claim 4, the amplitude setting means changes the amplitude of the identification signal in two steps, large and small. That is, the amplitude of the identification signal is
The frequency is set to a maximum predetermined amplitude within a range in which the frequency does not largely deviate from the resonance frequency of the fluid resonance system, and is set to an amplitude smaller than the predetermined amplitude when the frequency greatly deviates from the resonance frequency of the fluid resonance system. Also by this, the amplitude of the identification signal changes so as to substantially reflect the magnitude of the amplitude dependency of the fluid, so that the action of the invention according to claim 1 can be exerted. Moreover, if the amplitude of the identification signal only changes in two steps, the amplitude setting means can set the amplitude of the identification signal by a simpler process.

The invention according to claim 5 is the above-mentioned claims 1 to 4.
The transfer function identifying means in the invention according to claim 1 is further specified, wherein the Fourier transforming means Fourier transforms the residual vibration signal corresponding to each sine wave, and corresponds to the frequency of each sine wave in each residual vibration signal. Since the component to be extracted is extracted, the frequency component represents the transfer function for each sine wave.

However, since the level of the residual vibration signal read by the response signal reading means is affected by the amplitude of the identification signal being set individually for each frequency,
If the transfer function is obtained as it is, the difference in the amplitude of each sine wave is taken into the transfer function as the characteristic of the vibration transfer system. However, in the invention according to claim 5, the correction means is the Fourier transform means. Since the result is corrected by the amplitude of each sine wave (for example, each result of the Fourier transform means is divided by the amplitude of the original sine wave), it is possible to prevent the difference in the amplitude of each sine wave from affecting the transfer function. .

Since the signal corrected by the correction means is inverse Fourier transformed by the inverse Fourier transformation means, the impulse response as a transfer function is obtained. The invention according to claim 6 is a further specific form of the controlled vibration source according to the invention according to any one of claims 1 to 5, wherein a main fluid chamber is defined by a supporting elastic body, and the main fluid chamber is provided with an orifice. To the sub-fluid chamber, and the main fluid chamber, the orifice and the sub-fluid chamber are filled with fluid,
When the movable member is displaced by the actuator to positively deform the expansion direction spring of the support elastic body to generate an active support force, the fluid flowing between the main fluid chamber and the sub fluid chamber through the orifice is Utilizing the resonance effect,
The supporting force acting between the vibrating body and the support can be increased.

The invention according to claim 7 is the above-mentioned claims 1 to 6.
The active control means in the invention according to claim 1 is further specified, and a sequential update type adaptive algorithm (for example, LMS algorithm) is applied as a control algorithm. Therefore, the drive signal generating means generates a drive signal by filtering the reference signal with the adaptive digital filter, and the drive signal is supplied to the control vibration source to generate control vibration, while the filter coefficient updating means ,
Since the filter coefficient of the adaptive digital filter is sequentially updated according to the adaptive algorithm based on the residual vibration signal and the update reference signal, the filter coefficient of the adaptive digital filter is set to the optimum value that can reduce the vibration due to the control vibration generated from the control vibration source. Converge towards. Then, after the filter coefficient of the adaptive digital filter converges to the optimum value, the vibration is reduced by the control vibration generated from the control vibration source. Moreover, since the transfer function for generating the updating reference signal is identified with high accuracy by the actions of the invention according to claims 1 to 6, good vibration reduction control is executed.

According to the eighth aspect of the present invention, in the active vibration control device applied to the vehicle, the resonance frequency of the fluid resonance system is adjusted to be near the idle vibration frequency, so that it is relatively large near the idle vibration frequency. Since it becomes possible to generate an active supporting force, idle vibration can be effectively reduced.

On the other hand, according to the ninth aspect of the invention, in the active vibration control device applied to a vehicle, the resonance frequency of the fluid resonance system is set to be slightly higher than the idle vibration frequency (several H).
z) Since the frequency is adjusted to a low frequency, a relatively large active supporting force can be generated in the vicinity of the idle vibration frequency, and it is relatively effective in reducing engine shake. Idle vibration frequency is 20 to 3 for normal vehicles
Since the engine shake frequency is about 0 to about 15 Hz, which is lower than that, about 5 to 15 Hz, the resonance frequency of the fluid resonance system is about 1 to 5 Hz lower than the idle vibration frequency.
If the frequency is adjusted to about 5 to 25 Hz, in addition to the action substantially equivalent to that of the invention according to the eighth aspect, a damping force for reducing the engine shake is generated when the engine shake occurs.

[0037]

As described above, according to the present invention,
Since the identification signal is a sinusoidal signal and the amplitude setting means for appropriately setting the amplitude of the identification signal is provided, the transfer function can be identified with high accuracy, and the identification accuracy of the transfer function is deteriorated. Without having to do so, the effect of saving labor can be obtained. In particular, with the invention according to claims 2 to 4, the above effects can be more reliably obtained.

Further, according to the inventions of claims 8 and 9,
Since the idle vibration can be effectively reduced, the vehicle ride comfort can be improved, and the invention according to claim 9 can also effectively reduce the engine shake, so that the vehicle ride comfort is improved. It can be improved.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing a first embodiment of the present invention, and FIG. 1 is a schematic side view of a vehicle to which an active vibration control device according to the present invention is applied.

First, the structure will be described. An engine 30 is supported by a vehicle body 35 composed of suspension members and the like via an active engine mount 1 capable of generating an active supporting force according to a drive signal. . In addition, actually, between the engine 30 and the vehicle body 35, in addition to the active engine mount 1, a plurality of engine mounts that generate a passive supporting force according to the relative displacement between the engine 30 and the vehicle body 35 are also interposed. is doing. Examples of the passive engine mount include a normal engine mount that supports a load with a rubber-like elastic body, and a known fluid-filled mount in which a fluid is enclosed inside the rubber-like elastic body so that damping force can be generated. Insulator etc. can be applied.

On the other hand, the active engine mount 1 is constructed, for example, as shown in FIG. That is, the active engine mount 1 in this embodiment has a cap 2 integrally provided with a bolt 2a for mounting on the engine 30 in the upper part, and having a hollow inside and an open lower part. The upper end of the inner cylinder 3 whose axis faces the up-down direction is caulked.

The inner cylinder 3 has a shape in which the lower end side is reduced in diameter, and the lower end portion is horizontally bent inward,
A circular opening 3a is formed here. A diaphragm 4 is disposed inside the inner cylinder 3 so as to vertically divide the space inside the cap 2 and the inner cylinder 3 into two parts, which are sandwiched between the cap 2 and the inner cylinder 3 by caulking. There is. The space above the diaphragm 4 communicates with the atmospheric pressure by forming a hole in the side surface of the cap 2.

Further, an orifice structure 5 is arranged inside the inner cylinder 3. In the present embodiment, a thin-film elastic body (the outer peripheral portion of the diaphragm 4 may be extended) between the inner surface of the inner cylinder 3 and the orifice structure 5.
Is interposed, whereby the orifice constituting body 5 is firmly fitted inside the inner cylinder 3.

The orifice structure 5 is formed in a substantially columnar shape in alignment with the inner space of the inner cylinder 3, and has a circular recess 5a formed on the upper surface thereof. The recess 5a and the portion of the bottom surface facing the opening 3a communicate with each other via the orifice 5b. The orifice 5b is, for example, a groove that extends spirally along the outer peripheral surface of the orifice structure 5 and one end of the groove is a recess 5a.
And a flow path that allows the other end of the groove to communicate with the opening 3a.

On the other hand, the outer peripheral surface of the inner cylinder 3 is vulcanized and adhered to the inner peripheral surface of a thick-walled cylindrical support elastic body 6 having a slightly raised inner peripheral surface side. The outer peripheral surface is vulcanized and adhered to the upper part of the inner peripheral surface of the outer cylinder 7 whose upper end side is expanded in diameter.

The lower end of the outer cylinder 7 is caulked to the upper end of a cylindrical actuator case 8 having an open upper surface, and the lower end of the actuator case 8 is used for mounting on the vehicle body 35 side. The mounting bolt 9 is protruding. The head portion 9a of the mounting bolt 9 is housed in the central hollow portion 8b of the flat plate member 8a arranged in a state of being attached to the inner bottom surface of the actuator case 8.

Further, inside the actuator case 8, a cylindrical iron yoke 10A and the yoke 10A are provided.
Exciting coil 10B wound around the center of the magnet with its axis oriented vertically, and a permanent magnet 1 fixed with its poles oriented vertically on the upper surface of the portion of the yoke 10A surrounded by the exciting coil 10B.
An electromagnetic actuator 10 composed of 0C is provided.

Further, the upper end portion of the actuator case 8 is a flange portion 8A formed in a flange shape,
The lower end portion of the outer cylinder 7 is crimped to the flange portion 8A so that both are integrated, and the peripheral portion (end portion) of the circular metal leaf spring 11 is sandwiched between the crimping prevention portions. A magnetic path member 12 that can be magnetized by a rivet 11a is fixed to the electromagnetic actuator 10 side of the central portion of the leaf spring 11. The magnetic path member 12
Is an iron disc with a diameter slightly smaller than that of the yoke 10A,
The bottom surface is formed to have a thickness close to the electromagnetic actuator 10. The leaf spring 11 and the magnetic path member 12 constitute a movable member.

Further, at the caulking prevention portion, the ring-shaped thin film elastic body 13 and the flange portion 14a of the force transmitting member 14 are sandwiched between the flange portion 8A and the leaf spring 11.
And are supported. Specifically, on the flange portion 8A of the actuator case 8, the thin film elastic body 13, the flange portion 14a of the force transmission member 14, and the leaf spring 11 are superposed in this order, and the overlapped whole is covered with an outer cylinder. The lower end of 7 is caulked to be integrated.

The force transmitting member 14 is a short cylindrical member that surrounds the magnetic path member 12. The upper end portion of the force transmitting member 14 is a flange portion 14a, and the lower end portion thereof is on the upper surface of the yoke 10A of the electromagnetic actuator 10. Are connected. Specifically, the lower end portion of the force transmission member 14 is fitted into a circular groove formed in the peripheral edge portion of the upper end surface of the yoke 10A so that the both are joined. Further, the spring constant of the force transmitting member 14 during elastic deformation is set to a value larger than the spring constant of the thin film elastic body 13.

Here, in this embodiment, the supporting elastic body 6 is used.
The main fluid chamber 15 is formed in the portion defined by the lower surface of the plate spring 11 and the upper surface of the leaf spring 11, and the diaphragm 4 and the recess 5a.
A sub-fluid chamber 16 is formed in a portion defined by the above, and the main fluid chamber 15 and the sub-fluid chamber 16 communicate with each other via an orifice 5b formed in the orifice structure 5. A fluid such as oil is enclosed in the main fluid chamber 15, the sub fluid chamber 16 and the orifice 5b.

Therefore, in the active engine mount 1, the expansion spring of the supporting elastic body 6 that defines the main fluid chamber 15 and the diaphragm 4 that forms the auxiliary fluid chamber 16 are used as spring elements, and the orifice 5b is provided. A fluid resonance system having a fluid as a mass is configured, and the resonance frequency of the fluid resonance system is adjusted to an idle vibration frequency (20 Hz in this embodiment). That is, the spring constant of the support elastic body 6 and the diaphragm 4 and the orifice 5 are adjusted so that the resonance frequency of the fluid resonance system matches the idle vibration frequency.
The volume of b, etc. is appropriately selected.

The exciting coil 10B of the electromagnetic actuator 10 is adapted to generate a predetermined electromagnetic force according to the drive signal y which is a current supplied from the controller 25 through the harness 23a. Controller 25
Is a microcomputer, necessary interface circuit, A / D converter, D / A converter, amplifier, ROM, R
When the idle vibration, the muffled sound vibration, and the vibration during acceleration are input to the vehicle body 35, the active engine support 1 is configured to include a storage medium such as AM and reduce the vibration. Drive signal y to the active engine mount 1 is generated and output.

Here, idle vibration and muffled sound vibration are
For example, in the case of a reciprocating 4-cylinder engine, the engine rotation 2
The main cause is that the engine vibration of the next component is transmitted to the vehicle body 35. Therefore, if the drive signal y is generated and output in synchronization with the engine rotation secondary component, the vehicle side vibration can be reduced. . Therefore, in the present embodiment, the engine 30
Is provided with a pulse signal generator 26 that generates an impulse signal in synchronization with the rotation of the crankshaft (for example, in the case of a reciprocating 4-cylinder engine, one every time the crankshaft rotates 180 degrees) and outputs it as a reference signal x. However, the reference signal x is supplied to the controller 25 as a signal indicating the vibration generation state of the engine 30.

On the other hand, the yoke 1 of the electromagnetic actuator 10
So that it is sandwiched between the lower end surface of 0A and the upper surface of the flat plate member 8a forming the bottom surface of the actuator case 8,
A load sensor 22 for detecting an exciting force transmitted from the engine 30 through the support elastic body 6 is arranged, and a detection result of the load sensor 22 is supplied to the controller 25 as a residual vibration signal e through the harness 23b. ing. As the load sensor 22, specifically, a piezoelectric element, a magnetostrictive element, a strain gauge, or the like can be applied.

Then, the controller 25, based on the supplied residual vibration signal e and the reference signal x, is a synchronous type Filtered which is one of the adaptive algorithms of the successive update type.
By executing the -XLMS algorithm, the driving signal y for the active engine mount 1 is calculated, and the driving signal y is output to the active engine mount 1.

Specifically, the controller 25 has an adaptive digital filter W with a variable filter coefficient W _i (i = 0, 1, 2, ..., I-1: I is the number of taps), and the latest The adaptive digital filter W at a predetermined sampling clock interval from the time when the reference signal x is input.
Of one of outputting a filter coefficient W _i in the order as the drive signal y, it is adapted to execute a process of appropriately updating the filter coefficient W _i of the adaptive digital filter W based on the reference signal x and the residual vibration signal e.

The updating formula of the adaptive digital filter W is F
The following equation (1) follows the iltered-X LMS algorithm. W _i (n + 1) = W _i (n) −μR ^T e (n) (1) Here, the terms with (n) and (n + 1) represent values at sampling times n and n + 1, μ is a convergence coefficient. Further, theoretically, the update reference signal R ^T is
The reference signal x is a value obtained by filtering the transfer function C between the electromagnetic actuator 10 of the active engine mount 1 and the load sensor 22 with a transfer function filter C ^ modeled by a finite impulse response type filter. Is "1", which corresponds to the sum at the sampling time n of the impulse response waveforms when the impulse responses of the transfer function filter C ^ are generated one after another in synchronization with the reference signal x.

Further, theoretically, the reference signal x is filtered by the adaptive digital filter W to generate the drive signal y. However, since the magnitude of the reference signal x is "1", the filter coefficient W _{Even if i} is sequentially output as the drive signal y, the same result as when the filter processing result is used as the drive signal y is obtained.

Further, while the controller 25 executes the vibration reducing process using the adaptive digital filter W as described above, it also executes the process of identifying the transfer function C necessary for the vibration reducing control. ing.

That is, the controller 25 has a transfer function C
The identification process start switch 28 that is operated at the timing of starting the identification process is provided, and when the operator operates the identification process start switch 28 in the final process of the manufacturing line or at the time of regular inspection by the dealer, for example. , Transfer function C in controller 25
The identification process is executed. Note that normal vibration reduction processing is not executed during the identification processing of the transfer function C.

That is, the controller 25 controls the normal running state in which the vehicle ignition is turned on,
The vibration reduction process according to the synchronous Filtered-X LMS algorithm is executed. When the identification process start switch 28 is operated, the vibration reduction process is stopped and the transfer function C identification process is executed. There is.

Further, in the present embodiment, the identification processing of the transfer function C is performed by using a sinusoidal identification signal. Specifically, the sine wave identification signal is continuously output to the active engine mount 1 for a predetermined time instead of the drive signal y, and the residual vibration signal e is read, while the frequency of the identification signal is sequentially changed. The result obtained by repeatedly executing and performing FFT processing on each number sequence of the residual vibration signal e obtained by each data reading process to extract a component corresponding to the frequency of the identification signal and synthesizing each extracted frequency component is an inverse FFT. By processing, the impulse response as the transfer function C is obtained. The obtained impulse response is used as a transfer function filter C ^ of finite impulse response type, and the transfer function filter C ^ up to that time is used.
It is designed to be replaced with.

However, the amplitude A ₀ of the identification signal is set individually according to the frequency f ₀ of each identification signal, and the relationship between the frequency f ₀ and the amplitude A ₀ is determined by the active engine mount. It is set so as to follow the amplitude dependency of the fluid enclosed in the unit 1. Specifically, the amplitude A _{0 of the} identification signal whose frequency f ₀ is equal to the resonance frequency of the fluid resonance system in the active engine mount 1 is set to a predetermined amplitude which matches the maximum value of the drive signal y. , The amplitude A ₀ gradually decreases as the frequency f ₀ moves away from the resonance frequency of the fluid resonance system.

Corresponding to the variable amplitude A _{0 according} to the frequency f ₀ , the controller 25 divides each frequency component obtained by the FFT processing by the amplitude A ₀ of the corresponding identification signal. Correction processing is performed, the results of the correction processing are combined, and the inverse FFT processing is executed.

Next, the operation of this embodiment will be described. That is, as a result of adjusting the resonance frequency of the fluid resonance system in the active engine mount 1 to 20 Hz, a certain damping force is generated in the active engine mount 1 even when an engine shake, which is a vibration of 5 to 15 Hz, occurs. Therefore, the engine shake generated on the engine 30 side is damped to some extent by the active engine mount 1, and the engine shake is damped also by another fluid-filled engine mount or the like (not shown). Will be reduced. For engine shake,
In particular, it is not necessary to positively displace the movable plate 12.

On the other hand, when a vibration having a frequency equal to or higher than the idle vibration frequency is input, the controller 25 executes a predetermined arithmetic process, outputs a drive signal y to the electromagnetic actuator 10, and outputs the drive signal y to the active engine mount 1. Generates an active bearing force that can reduce vibration.

This will be specifically described with reference to FIG. 3, which is a flow chart showing the outline of the processing executed in the controller 25 when the idle vibration and the muffled sound vibration are input.
First, after a predetermined initialization is performed in step 101, the process proceeds to step 102, and the update reference signal R ^T is calculated based on the transfer function filter C ^. In this step 102, the update reference signals R ^T for one cycle are collectively calculated.

Then, after shifting to step 103 and the counter i is cleared to zero, the routine proceeds to step 104,
I-th filter coefficient W _{i of the} adaptive digital filter W
Is output as the drive signal y.

When the drive signal y is output in step 104, the process proceeds to step 105 and the residual vibration signal e is read. Then, in step 106, the counter j is cleared to zero, then in step 107, the j-th filter coefficient W _{j of} the adaptive digital filter W is updated according to the above equation (1).

When the updating process in step 107 is completed, the routine proceeds to step 108, where it is judged whether or not the next reference signal x is inputted. If it is judged here that the reference signal x is not inputted, , The process proceeds to step 109 in order to update the next filter coefficient of the adaptive digital filter W or output the drive signal y.

In step 109, it is determined whether or not the counter j has reached the number of output times T _y (to be precise, the counter j starts from 0, so the value obtained by subtracting 1 from the number of output times T _y ). In this determination, it is determined whether the filter coefficient W _i of the adaptive digital filter W is output as the drive signal y in step 104 and then the filter coefficient W _i of the adaptive digital filter W is updated by the necessary number as the drive signal y. It is for judging. Therefore, if the determination in step 109 is “NO”, step 11
After incrementing the counter j by 0, step 1
Returning to 07, the above processing is repeatedly executed.

However, the determination in step 109 is "YE
In the case of “S”, it can be determined that the updating process of the necessary number of filter coefficients as the drive signal y among the filter coefficients of the adaptive digital filter W has been completed.
After shifting to 1 and incrementing the counter i, after executing the processing of step 104, wait until the time corresponding to the interval of the predetermined sampling clock elapses, and when the time corresponding to the sampling clock elapses. Then, the processing returns to step 104 and the above-mentioned processing is repeatedly executed.

On the other hand, when it is determined in step 108 that the reference signal x is input, the process proceeds to step 112, and the counter i (to be precise, since the counter i starts from 0, 1 is added to the counter i). Value) is stored as the latest output count T _y , and then the process returns to step 102 and the above-described processing is repeatedly executed.

As a result of repeatedly executing the processing shown in FIG. 3, the controller 25 moves the active engine mount 1
For the electromagnetic actuator 10 of, from the time when the reference signal x is input, at the sampling clock interval,
The filter coefficient W _i of the adaptive digital filter W is sequentially supplied as the drive signal y.

As a result, the driving signal y is applied to the exciting coil 10B.
However, since a constant magnetic force is already applied to the magnetic path member 12 by the permanent magnet 10C,
It can be considered that the magnetic force generated by the exciting coil 10B acts to strengthen or weaken the magnetic force of the permanent magnet 10C. That is, in the state where the drive signal y is not supplied to the exciting coil 10B, the magnetic path member 12 is displaced to a neutral position where the supporting force of the leaf spring 11 and the magnetic force of the permanent magnet 10C are balanced. When the drive signal y is supplied to the exciting coil 10B in this neutral state, if the magnetic force generated in the exciting coil 10B by the drive signal y is in the opposite direction to the magnetic force of the permanent magnet 10C, the magnetic path member 12 is generated.
Is displaced in the direction in which the clearance with the electromagnetic actuator 10 increases. On the contrary, if the magnetic force generated in the exciting coil 10B is in the same direction as the magnetic force of the permanent magnet 10C, the magnetic path member 12 is displaced in the direction in which the clearance with the electromagnetic actuator 10 decreases.

As described above, the magnetic path member 12 can be displaced in both the forward and reverse directions. If the magnetic path member 12 is displaced, the main main fluid chamber 1
The volume of 5 changes, and the supporting elastic body 6
The expansion spring is deformed, so that the active engine mount 1 is actively supported in both forward and reverse directions.

Then, each filter coefficient W _i of the adaptive digital filter W which becomes the drive signal y is a synchronous filter.
Since it is sequentially updated by the above equation (1) according to the red-X LMS algorithm, after a certain amount of time has passed and each filter coefficient W _i of the adaptive digital filter W has converged to the optimum value, the drive signal y is By being supplied to the active engine mount 1, idle vibration and muffled sound vibration transmitted from the engine 30 to the vehicle body 35 side via the active engine mount 1 are reduced.

The above is the operation of the vibration reduction process executed when the vehicle is traveling. On the other hand, when the operator operates the identification process start switch 28 in the final process of the production line before the vehicle is shipped, for example, the identification process of the transfer function C as shown in FIG. 4 is executed.

That is, when the identification process of the transfer function C is started, first in step 201, the frequency f ₀ of the identification signal is set to the idle vibration frequency f _id (in this case, the frequency at which the identification process is started). 20Hz).
The idle vibration frequency f _id is set as the frequency at which the identification process is started because the vibration reduction control is executed in the situation where the vibration equal to or higher than the idle vibration frequency is input as described above.
This is because vibration reduction control is not particularly executed for vibrations smaller than that.

[0081] Then, the process proceeds to step 202, by referring to the map as shown in FIG. 5 stored in the nonvolatile memory, reads the amplitude A ₀ corresponding to the frequency f _0,
In step 203, a sine wave having a frequency f ₀ and an amplitude A ₀ is supplied to the active engine mount 1 as an identification signal. Then, the electromagnetic actuator 10 in the active engine mount 1 is driven by the identification signal to generate identification vibration, and the identification vibration propagates through each member and reaches the load sensor 22.

Therefore, the routine proceeds to step 204, where the residual vibration signal e is read, then proceeds to step 205, and it is judged whether or not a sufficient number of residual vibration signals e have been read. Since the value set as a sufficient number of residual vibration signals e is obtained as the impulse response of the transfer function C, the time required for the impulse response to be sufficiently attenuated is divided by the sampling clock. It should be greater than or equal to the value. However, since the FFT operation is performed later on the residual vibration signal e captured as a time series,
It is desirable that the number of captured residual vibration signals e be a power of 2, and if the residual vibration signals e are read in an extremely large amount, the read time becomes long and the time required for the FFT calculation also increases. Since there is also a problem that it becomes long, the value set as a sufficient number of residual vibration signals e is a width of 2 that exceeds the number required when the impulse response is sufficiently attenuated divided by the sampling clock. It is desirable to set the minimum value of the power values. For example, if the sampling clock is 2 msec and the impulse response decays sufficiently for 0.2 sec
In this case, 0.2 sec / 2 msec = 100, so the value set in step 205 is 128.

If the determination in step 205 is "NO", the process returns to step 203 and the identification signal output process (step 203) and the residual vibration signal e reading process (step 204) are repeatedly executed.

Then, the determination in step 205 is "YE
When it becomes "S", the process proceeds to step 206. The residual vibration signal e read one after another in step 204 is
It is stored as time series data corresponding to the frequency f ₀ .

Next, the routine proceeds to step 206, where a new frequency f ₀ is calculated by adding the increment Δf to the current frequency f ₀ . The increment Δf may be appropriately determined according to the precision required for the transfer function filter C ^.
Desirably, it is set to about 2 to 4 Hz.

Next, the routine proceeds to step 207, where it is judged whether or not the new frequency f ₀ exceeds the maximum value f _{max of the} frequency for performing the identification processing. The maximum value f _max may be set to the maximum frequency of the vibration that is the target of the vibration reduction processing. For example, in the case of a reciprocating 4-cylinder engine, the maximum value of the engine speed in the normal use range is 6000 to 750.
Since the number of rotations is 0 and the maximum frequency of vibration is about 200 to 250 Hz, the maximum value f _max is set to about 200 to 250 Hz.

If the determination in step 207 is "NO", the process returns to step 202 and the above-mentioned processing is executed again. Therefore, the series of processes in steps 202 to 206 is executed until the determination in step 207 becomes “YES”. That is, the process of steps 202 to 204 is executed for each frequency f _{0 that} changes by the increment Δf in the range from the idle vibration frequency f _id to the maximum value f _max , and thus the process of step 207 is “ At the time point of “YES”, the residual vibration signal e stored as the time series data by the process of step 204 has the frequency f _0.
It means that the same number is stored as the number of types.

Therefore, the determination in step 207 is "YE
S ”, the process proceeds to step 208 and the frequency f ₀
The FFT operation is performed on each of the time series data of the residual vibration signal e stored for each, and the frequency component of each time series data is extracted. However, what is needed here is not the components of all the frequencies for each time series data, but only the components corresponding to the frequency of the original sine wave determined by the corresponding frequency f ₀ . On the other hand, rather than performing a strict FFT calculation, only a calculation sufficient for obtaining the component of the frequency f ₀ corresponding to each time series may be performed.

Next, in step 209, a correction calculation for correcting the magnitude of each frequency component obtained in step 208 is performed. Specifically, the correction operation performed here is an operation of dividing the frequency component by the amplitude of the corresponding sine wave. For example, when the amplitude of the identification signal when the frequency f ₀ is equal to the idle vibration frequency f _id is 1, and when the amplitude of the identification signal is 0.5 at other frequencies f ₀ , the frequency component is 0.5. Divide by (double). This changes the amplitude A ₀ of the identification signal to its frequency f _0.
Since the difference of the amplitude A ₀ is included in the result of the FFT calculation, if the transfer function C is obtained as it is, the difference of the amplitude A ₀ of the vibration transfer system is also obtained. This is because the characteristic is incorporated into the transfer function C.

Then, the process proceeds to step 210, where the combined frequency components are subjected to inverse FFT operation to be converted into an impulse response on the time axis, then the process proceeds to step 211 and the impulse response obtained in step 210 is converted. It is stored as a new transfer function filter C ^. When the storage of the transfer function filter C ^ is completed, the identification process of the transfer function C this time is ended.

As described above, according to the present embodiment, the transfer function C is identified at an arbitrary timing after being mounted on the vehicle, and the transfer function filter C ^ is identified by the identified transfer function C.
Therefore, the transfer function filter C ^ with high accuracy is used for vibration reduction control compared to the case where the transfer function C obtained in the laboratory is applied to all vehicles. By identifying the transfer function C for each inspection, it is possible to respond to changes in the vibration transfer system due to changes over time in each component.
Good vibration reduction control can be executed.

The transfer function C can be obtained even when an identification signal based on a white noise signal is generated, but when the white noise signal is supplied to the electromagnetic actuator 10 to cause the identification vibration, The output of the identification vibration is dispersed in a wide frequency band as shown by the broken line in FIG. 6, and each frequency component becomes extremely small. Therefore, in order to obtain the transfer function C with high accuracy, an adaptive calculation based on the white noise signal and the identification vibration generated by the white noise signal must be performed for a relatively long time. On the other hand, in the present embodiment using the identification signal generated based on the sine wave, the output of the identification vibration is concentrated at a specific frequency as shown by the solid line in FIG. Not only the calculation time for each frequency is shortened, but also the entire calculation time is shortened as compared with the case where the identification is performed by the white noise signal.

As a result, the transfer function C can be identified in a relatively short time even with the controller 25 having a relatively low capacity mounted on the vehicle. Therefore, for example, even if the identification process start switch 28 is operated to perform the identification process of the transfer function C in the final process of the manufacturing line, the line speed does not have a great influence, or the dealer regularly performs the process. Even if the identification process start switch 28 is operated during the inspection to perform the identification process of the transfer function C, it is possible to avoid a significant increase in the work time.

Here, the spring constant of the active engine mount 1 having the fluid resonance system as shown in FIG. 2 largely varies depending on the magnitude of the amplitude as shown in FIG. 7 due to the influence of the fluid amplitude dependency. come. Specifically, the spring constant K
Has a small value over a wide frequency band when the amplitude is large, but has a large value at the resonance frequency and its vicinity when the amplitude is small. Then, the amplitude of the control vibration generated in the active engine mount 1 when the vibration reduction control is actually executed must be increased in order to sufficiently reduce the vibration generated in the engine 30.

However, as can be seen from FIG. 7, the spring constant K greatly differs depending on the magnitude of the amplitude at the resonance frequency of the fluid resonance system and its vicinity, and the magnitude of the amplitude increases as the distance from the resonance frequency increases. The influence on the magnitude of the spring constant K becomes smaller.

This means that for frequencies far from the resonance frequency, the accuracy of the obtained transfer function C is not significantly affected by increasing or decreasing the amplitude of the identification signal.
It means that.

Therefore, as in the present embodiment, the amplitude A _{0 of the} identification signal is individually set based on its frequency f ₀ with the characteristics shown in FIG. 5, and the correction calculation in step 209 is performed. It is possible to reduce power consumption when executing the identification processing without adversely affecting the accuracy of the transfer function C to be identified.

Moreover, since the amplitude A _{0 of the} identification signal is smoothly changed so as to follow the amplitude dependency of the fluid, the spring constant K when performing the identification process and the vibration reduction control when actually performing the vibration reduction control are performed. Can be made extremely small over the entire frequency band, and the accuracy of the identified transfer function C is not adversely affected at all.

If the power consumption is low, the load of the battery mounted on the vehicle can be reduced.
This is particularly useful for the configuration of the present embodiment in which the identification process is performed when the engine 30 is stopped, and it is possible to further reduce the possibility that the identification process becomes unexecutable due to a battery exhaustion or a battery voltage drop. Of.

Here, in the present embodiment, the engine 30
Corresponds to the vibrating body, the vehicle body 35 corresponds to the supporting body, the active engine mount 1 corresponds to the controlled vibration source, the pulse signal generator 26 corresponds to the reference signal generating means, and the load sensor 2
2 corresponds to the residual vibration detecting means, the processing of FIG. 3 corresponds to the active control means, and steps 201, 203 and 205 of FIG.
The processing of ˜207 corresponds to the identification signal supplying means, the processing of step 204 of FIG. 4 corresponds to the response signal reading means,
The processing of steps 208 to 210 in FIG. 4 corresponds to the transfer function identifying means, the processing of step 202 in FIG. 4 and the map as shown in FIG. 5 correspond to the amplitude setting means, and the processing of step 208 in FIG. 4 is Fourier. 4 corresponds to the correction unit, the process of Step 210 of FIG. 4 corresponds to the inverse Fourier transform unit, and the process of Step 104 of FIG. 3 corresponds to the drive signal generation unit. Then, the process of step 102 of FIG. 3 corresponds to the updating reference signal generating means, and the process of step 107 of FIG. 3 corresponds to the filter coefficient updating means.

FIG. 8 is a diagram showing a second embodiment of the present invention. As with FIG. 5 in the first embodiment, FIG. 8 shows the relationship between the frequency f _{0 of the} identification signal and the amplitude A _0. Shows. Note that the overall configuration, the content of the vibration reduction process, and the identification process are the same as those in the first embodiment, and thus the duplicated description will be omitted.

That is, in the present embodiment, the amplitude A _{0 of the} identification signal is changed in two steps, large and small, according to the frequency f ₀ . That is, if the difference (| f ₀ −f _id |) between the frequency f ₀ and the idle vibration frequency f _id is less than the predetermined threshold f _th , the amplitude A ₀ of the identification signal is large, and the difference is the predetermined threshold. The amplitude A ₀ of the identification signal having a value of f _th or more is set to be small. Note that the amplitude A ₀ when it is large
Is a predetermined amplitude that matches the maximum value of the amplitude of the drive signal y,
The amplitude A ₀ when it is small is, for example, half of the maximum value of the amplitude of the drive signal y.

Even with such a configuration, the amplitude A _{0 of the} identification signal is set so as to substantially reflect the magnitude of the amplitude dependency of the fluid, and therefore the same operational effect as in the first embodiment described above. Can be obtained.

Moreover, the relationship between the frequency f ₀ and the amplitude A ₀ as shown in FIG. 8 does not need to be stored as a map in particular, and the threshold value f _th and the two values of the amplitude A ₀ are stored. Since this is all that is required, it can contribute to a reduction in memory capacity.

[0105] The value of the amplitude A ₀ also, the ratio of the amplitude A ₀ of the time smaller the amplitude A ₀ when it is larger 2: if set to 1, the correction in step 209 to be executed after the operation However, it suffices to double the frequency component corresponding to the identification signal having a small amplitude A ₀ , and the calculation for doubling actually only shifts one bit, so the calculation load is also reduced. There is also the advantage of being done.

Other functions and effects are similar to those of the first embodiment. In each of the above-described embodiments, the resonance frequency of the fluid resonance system in the active engine mount 1 is made to match the idle vibration frequency f _id , which utilizes the resonance of the fluid resonance system. However, even if the resonance frequency of the fluid resonance system and the idle vibration frequency f _id do not completely match, the fluid resonance can be used for vibration reduction.

Therefore, if the resonance frequency of the fluid resonance system is adjusted to a frequency lower than the idling vibration frequency f _id by several Hz (preferably a frequency between the idling vibration frequency f _id and the engine shake frequency), the engine shake is generated. The active engine mount 1 can be used more effectively as well. For example, the idle vibration frequency f _id is 20 Hz and the engine shake frequency is 1
If the frequency is 0 Hz, the resonance frequency of the fluid resonance system is set near 15 Hz, which is an intermediate frequency between the two, to reduce idle vibration (slightly lower than the case of each of the above embodiments). However, it can effectively function as an active engine mount 1 that generates an active supporting force, and can more effectively function as a fluid-filled engine mount that passively generates a damping force with respect to an engine shake.

Further, in each of the above embodiments, the residual vibration is detected by the load sensor 22 incorporated in the active engine mount 1, but the present invention is not limited to this. An acceleration sensor for detecting floor vibration may be provided, and the output signal of the acceleration sensor may be the residual vibration signal e.

The object to which the present invention is applied is not limited to the vehicle, and the present invention can be applied to an active vibration control device for reducing the vibrations other than the engine 30. It is possible to obtain the same operational effects as those of the above-described embodiments regardless of the target. For example, the present invention can be applied to a device that reduces vibrations transmitted from a machine tool to a floor or a room.

Further, in each of the above embodiments, the synchronous filtere is used as an algorithm for generating the drive signal y.
Although the d-X LMS algorithm is applied, the applicable algorithm is not limited to this, and may be, for example, a normal Filtered-X LMS algorithm.

[Brief description of drawings]

FIG. 1 is a schematic side view of a vehicle showing a first embodiment.

FIG. 2 is a sectional view showing an example of an active engine mount.

FIG. 3 is a flowchart showing an outline of vibration reduction processing.

FIG. 4 is a flowchart showing an outline of transfer function identification processing.

FIG. 5 is a diagram showing a relationship between frequency and amplitude of an identification signal.

FIG. 6 is a frequency characteristic diagram illustrating a difference between a case where a sine wave is used as an identification signal and a case where a white noise signal is used.

FIG. 7 is a diagram showing the relationship between the magnitude of the amplitude and the spring constant.

FIG. 8 is a diagram showing a relationship between a frequency and an amplitude of an identification signal in the second embodiment.

[Explanation of symbols]

1 Active engine mount (controlled vibration source) 5b orifice 10 Electromagnetic actuator 11 leaf spring 12 Magnetic path member 15 Main fluid chamber 16 Sub-fluid chamber 22 Load sensor (residual vibration detection means) 25 controller 26 pulse signal generator (reference signal generating means) 28 Identification process start switch 30 engine (vibrating body) 35 Car body (support)

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05D 19/02 F16F 15/02 G10K 11/16 G10K 11/178

Claims (9)

(57) [Claims] 1. A control vibration source interposed between a vibrating body and a support to generate control vibration, reference signal generating means for detecting a vibration occurrence state of the vibrating body and outputting it as a reference signal; The residual vibration detecting means for detecting the residual vibration and outputting it as a residual vibration signal, and the vibration using a control algorithm including a transfer function between the control vibration source and the residual vibration detecting means based on the reference signal and the residual vibration signal. And an active control means for driving the controlled vibration source so that the controlled vibration source has a fluid resonance system for generating the controlled vibration. Identification signal supply means for sequentially changing the frequency of a wavy identification signal and supplying it to the control vibration source, and the residual when vibration according to the identification signal is emitted from the control vibration source. A response signal reading means for reading the vibration signal, a transfer function identification means for identifying the transfer function on the basis of the residual vibration signal read by the response signal reading means,
An active vibration control device comprising: an amplitude setting unit that sets the amplitude of the identification signal so that the frequency of the identification signal becomes smaller for an identification signal whose frequency deviates from the resonance frequency of the fluid resonance system. 2. The amplitude setting means sets a large amplitude of the identification signal whose frequency is equal to the resonance frequency of the fluid resonance system, and sets the amplitude of the identification signal whose frequency is far from the resonance frequency of the fluid resonance system. The active vibration control device according to claim 1, wherein the active vibration control device is set small. 3. The amplitude control means sets the amplitude of the identification signal whose frequency is equal to the resonance frequency of the fluid resonance system, and the active control means when the frequency of vibration generated in the vibrating body is equal to the resonance frequency. Is set to a predetermined amplitude that matches the amplitude of the drive signal supplied to the controlled vibration source, and the amplitude of the identification signal is gradually reduced as the frequency deviates from the resonance frequency of the fluid resonance system. Item 1. The active vibration control device according to item 1. 4. The amplitude setting means generates an amplitude of the identification signal in the vibrating body for an identification signal in which the difference between the frequency and the resonance frequency of the fluid resonance system is less than a predetermined threshold value. When the frequency of the vibration to be set is equal to the resonance frequency, the active control means sets a predetermined amplitude that matches the amplitude of the drive signal supplied to the control vibration source, and the frequency and the resonance frequency of the fluid resonance system The active vibration control device according to claim 1, wherein an identification signal whose difference is equal to or more than the threshold value is set to an amplitude smaller than the predetermined amplitude. 5. The Fourier transform means for transforming the residual vibration signal read by the response signal reading means by Fourier transforming each of the identification signals to extract a component corresponding to the frequency of the identification signal. A correction means for correcting each frequency component extracted by the Fourier transform means with the amplitude of each identification signal, and an inverse Fourier transform of a combination of the results of the correction means to obtain an impulse response as the transfer function. An active vibration control device according to any one of claims 1 to 4, further comprising Fourier transforming means. 6. The control vibration source communicates with the main fluid chamber via an orifice, a support elastic body interposed between the vibrating body and the support body, a main fluid chamber defined by the support elastic body. A variable volume sub-fluid chamber, a fluid enclosed in the main fluid chamber, the sub-fluid chamber and an orifice, a movable member forming a part of a partition wall of the main fluid chamber, and the movable member being the main fluid. An actuator that displaces in a direction that changes the volume of the chamber, and the fluid resonance system includes an expansion direction spring of a partition wall that defines the main fluid chamber and an auxiliary fluid chamber, and a fluid in the orifice. The active vibration control device according to any one of claims 1 to 5. 7. The active control means generates an adaptive digital filter having a variable filter coefficient, and a drive signal for generating and outputting a drive signal for driving the controlled vibration source by filtering the reference signal with the adaptive digital filter. Generating means, updating reference signal calculating means for calculating an updating reference signal which is a response result when the reference signal is input to the transfer function, and the control algorithm based on the residual vibration signal and the updating reference signal. 7. The active vibration control device according to claim 1, further comprising a filter coefficient updating unit that updates the filter coefficient of the adaptive digital filter according to the successive update adaptive algorithm. 8. The active vibration according to claim 1, which is applied to a vehicle, the vibrating body is an engine, and a resonance frequency of the fluid resonance system is adjusted to be near an idle vibration frequency. Control device. 9. The method according to claim 1, which is applied to a vehicle, the vibrating body is an engine, and the resonance frequency of the fluid resonance system is adjusted to a frequency slightly lower than an idle vibration frequency. Active vibration control device.