WO2014192088A1 - Active vibration damping device and active vibration damping method - Google Patents

Abstract

Provided is a low-cost active vibration damping device with which vibration can be reduced in a device for which the influence of vibration must be eliminated. This vibration damping device, which is attached to a structure for which vibration must be reduced, is characterized by being equipped with multiple identical vibration detection means that detect distortion at a portion of the subject structure, multiple identical vibration generation means that generate distortion at a different portion of the subject structure, and a control means that, on the basis of signals from the vibration detection means, generates a control signal that sets the driving force of the vibration generation means, with the condition of the control signal for setting the driving force of the vibration generation means being changed with respect to changes in the frequency and magnitude of the vibration of the subject as detected by the vibration detection means.

Description

Active damping device and active damping method

The present invention relates to an active vibration damping device and an active vibration damping method.

Generally, in a device having a vibration source such as a motor, this vibration often has an adverse effect on controlling a target object of the apparatus. In order to suppress this vibration, there is provided a vibration detecting means for detecting the vibration, and processing the detection signal indicating the vibration detected by the vibration detecting means to drive the vibration generating means so as to suppress the vibration. It has been known.

Conventionally, as such an apparatus, a technique is known in which vibration detection means is attached to one side of a panel to be subjected to vibration suppression, and vibration generation means is provided on the other side (back side) of the panel.

In this technique, the vibration generating means is composed of a flat element that generates distortion and is affixed to one side of the panel, and the vibration detecting means is provided on the other side of the panel when there is a step-like variation. On the (back side), the panel is disposed in an area on the panel where the initial displacement direction and the steady displacement direction coincide. Such a technique is described in, for example, Japanese Patent Application Laid-Open No. 2006-215993.

JP 2006-215993 A

Here, the vibration suppression will be described with a specific example. In order to suppress the vibration of the apparatus whose influence should be eliminated, for example, in an information storage device equipped with a plurality of recording devices, the vibration is caused by the vibration. This leads to performance degradation of the information storage device. Here, a description will be given using a storage device equipped with an HDD (Hard Disk Drive) as a commonly used recording device. The HDD itself generates vibrations by operating the internal actuator and the spindle of the disk. This vibration is transmitted through the housing of the storage device to another HDD that is attached to the storage device that is not performing input / output, and the HDD that is not performing input / output also vibrates. The vibrations from the HDDs that are not performing input / output overlap multiple times and are transmitted as external vibrations to the HDDs that are performing input / output, thereby affecting the operation of the HDDs that are performing input / output, and the amount of input / output It will adversely affect. Moreover, in order to cool the apparatus, a fan for forcibly circulating air to dissipate heat is often mounted. In this case, there is a case where the vibration generated by the operation of the fan is transmitted as external vibration to the HDD performing input / output via the housing of the storage device.

In addition, vibration such as measuring equipment such as electron microscopes, manufacturing equipment that performs ultra-fine processing, and the like, which require high-accuracy imaging of extremely small areas, reduces the performance of the device. In an apparatus that should be eliminated, suppressing vibration is an important issue. In addition, the vibration of the structure can be a source of noise, which can reduce the added value of the device.

In order to reduce the vibration, an active vibration control device that detects the vibration of the object, generates a control signal that suppresses the vibration, drives the vibration generating means, and reduces the vibration. (Hereinafter, this device is referred to as an active vibration control device.) On the other hand, since the active vibration control device is difficult to design, it is necessary to design it specially for the application target. Unless the target is to be produced in large quantities, the cost as a vibration control device is high. Furthermore, it is not suitable for mass-produced products, which have high vibration damping effects, but are also greatly affected by changes in the frequency of vibrations of interest.

In such vibration suppression, when the vibration detection means and the vibration generation means are arranged in the same place as in the above-described prior art, for example, when the target structure is a substantially box-shaped housing or the like, In suppressing vibration, there is a problem that the vibration generating means for suppressing vibration cannot be arranged efficiently. For example, in the case of a roughly box-shaped structure, the vibration mode presents an overall complex aspect, so a position where the amplitude of the target vibration can be detected effectively and a driving force applied to suppress the vibration are applied. This is because the position suitable for this is not always the same. That is, in the above prior art, for example, when the target structure is a substantially box-shaped housing or the like, the vibration generating means for suppressing the vibration cannot be disposed at an efficient position in order to suppress the vibration.

In particular, when an acceleration sensor is used as the vibration detection means, when the vibration source is inside the target as in the example of the information storage device described above, the vibration to be reduced by the active vibration control device is this vibration. . However, since the acceleration sensor picks up external vibrations, the stability and vibration control performance of the control system cannot be obtained.

Therefore, the present invention is to reduce the influence of vibration, and to realize a vibration damping device having high vibration damping performance at low cost in a case where a casing is vibrated by an internal vibration source. An object of the present invention is to provide an active vibration damping device and an active vibration damping method.

In order to achieve the above object, according to the present invention, a vibration detecting means provided in a part of a structure for detecting vibration, a vibration generating means for generating strain in a part different from the part of the structure, and vibration detection Control means for generating a control signal for determining the driving force of the vibration generating means in response to a signal from the means, and with respect to changes in the frequency and magnitude of the vibration of the object detected by the vibration detecting means. The mode of the control signal that determines the driving force of the vibration generating means is changed.

One example is a vibration damping device that is attached to a target structure whose vibration is to be reduced, and includes a plurality of identical vibration detection means for detecting distortion of a part of the target, and parts of the target that are different locations. A plurality of the same vibration generating means for generating a strain on the surface, and a control means for generating a control signal for determining the driving force of the vibration generating means based on a signal from the vibration detecting means, and the vibration detecting means The aspect of the control signal that determines the driving force of the vibration generating means is changed with respect to the change in the frequency and magnitude of the detected vibration of the object.

Issues, configurations, and effects other than those described above will be clarified by the following description of the embodiments.

According to the present invention, since the arrangement of the vibration generating means is determined according to the characteristics of the target, it is possible to generate a driving force that can efficiently reduce the vibration of the target.

It is a figure which shows Example 1 of the active damping device in this invention. FIG. 6 is a diagram illustrating an operation of the first embodiment. 1 is a block diagram of Embodiment 1. FIG. 3 is an enlarged view of the vicinity of the piezoelectric sensor 3 of Example 1. FIG. FIG. 3 is an enlarged view of the vicinity of the piezoelectric actuator 4 according to the first embodiment. FIG. 6 is a diagram illustrating a method for adjusting control characteristics according to the first embodiment. FIG. 6 is a diagram showing Example 2. 6 is an enlarged view of the vicinity of a piezoelectric sensor 3 of Example 3. FIG.

In the following description of the embodiments, the object whose vibration is to be reduced will be described as an information storage device using, for example, a RAID device.

FIG. 1 is a diagram showing the first embodiment. FIG. 1 shows an example in which an active vibration damping device 1 of the present invention is mounted on a target storage device 2. Piezoelectric sensors 3 a and 3 b are attached to the structural plate 6 on the side surface of the housing of the storage device 2. Further, plate-like piezoelectric actuators 4 a, 4 b, 4 c are attached to the other parts of the structural plate 6, and the piezoelectric sensors 3 a, 3 b and the piezoelectric actuators 4 a, 4 b, 4 c are connected to the controller 5.

A mechanism for reducing vibration of the structural plate 6 of the storage device 2 will be described with reference to FIG. FIG. 2 is a simplified illustration of the case where the structural plate 6 is subjected to bending vibration. The dotted line in this figure represents the original shape of the storage device 2. When the storage device 2 vibrates, deformation indicated by a solid line occurs, and the structural plate 6 bends, so that the piezoelectric sensors 3a and 3b are deformed as the structural plate 6 is deformed, and output a voltage output 7 corresponding to the amount of strain. . This is an input to the controller 5. In the controller 5, the feedback circuit shown in FIG. 3 is formed so that the voltage output 7 becomes zero at the target vibration frequency, whereby the control output 8 is sent to the piezoelectric actuators 4 a, 4 b, 4 c. . In response to the control output 8, the piezoelectric actuators 4a to 4c generate distortion and deform the structural plate 6 so as to suppress vibration. Thereby, the vibration generated in the structural plate 6 is reduced.

In this example, two sensors are used like the piezoelectric sensors 3a and 3b. However, when the number of target vibrations is large, that is, when the number of vibration modes to be dealt with in the storage device 2 is large. Is preferable because a plurality of vibrations can be detected by increasing the number of piezoelectric sensors 3. This is because which part vibrates greatly depending on the vibration mode, and even if one sensor detects this, there is a vibration mode that is difficult to detect depending on the position of the sensor. Further, in the case of a roughly box-shaped enclosure like the storage device 2 of this example, the vibration mode has a complicated aspect (FIG. 2 is simplified for the sake of explanation). Therefore, it is desirable to affix the piezoelectric sensor 3 not only to the structural plate 6 which is one component but also to other components.

From the viewpoint of damping performance, it is better that the number of piezoelectric sensors 3 is larger. However, in practice, it is desirable that the number of piezoelectric sensors 3 is small in terms of cost and man-hours to be attached. Accordingly, the necessary and sufficient number of piezoelectric sensors 3 is sufficient based on the number of vibration modes to be controlled. The piezoelectric sensor 3 used in the present embodiment has the same shape and properties according to the same standard, and this enables better measurement of the vibration state of the target, while the same standard improves the productivity of the sensor. Thus, the part cost can be reduced.

Similarly, with respect to the piezoelectric actuator 4 having the role of deforming the structural plate 6 so as to reduce the vibration, in order to obtain a driving force large enough to cause the structural plate 6 to be deformed with respect to the target vibration mode, It is desirable to use a plate-like piezoelectric element having a larger area. However, there is a problem that it is sometimes difficult to secure a place where a large-area plate-like piezoelectric element is pasted, and a large-area piezoelectric element is expensive due to difficulty in manufacturing. Therefore, in the apparatus of the present invention, the plate-like piezoelectric actuator 4 has the same shape and performance according to the same standard, and by using a plurality of these, the driving force as a whole is ensured and vibration is generated according to the characteristics of the target. By determining the number and arrangement of means in advance, it is possible to generate a driving force that can efficiently reduce the vibration of the object. Furthermore, component costs can be reduced for the same reason as described above.

Since the active damping device is specially designed for each individual device, the cost of the damping device tends to be high unless the application target is mass-produced. The vibration damping device can reduce the cost as a vibration damping device additionally used by using only the standardized sensor and actuator.

In this embodiment, the piezoelectric sensor 3 and the piezoelectric actuator 4 are installed at different locations on the structural plate 6. There is also a method of arranging the sensor and actuator in the same place. However, if the target structure is a roughly box-shaped housing, etc., the vibration mode has an overall complex aspect, so the amplitude of the target vibration is effective. The position that can be detected automatically and the position that is suitable for applying the driving force so as to suppress the vibration are not necessarily the same. Therefore, in the present invention, the piezoelectric sensor 3 and the piezoelectric actuator 4 can be arranged at positions where vibrations are detected or suppressed more effectively.

FIG. 4 shows an enlarged view of the piezoelectric sensor 3 used in the first embodiment. The piezoelectric sensor 3 is formed by forming a piezoelectric element such as PZT into a thin plate shape, and affixing the structure plate 6 with an adhesive 9. In order to detect the strain state of the structural plate 6 with high accuracy, it is desirable to use a highly rigid adhesive 9. In this embodiment, the type having the electrodes 13 on both sides is used and the signal line 14 is taken out by soldering, but other types can be used. It is effective to attach the piezoelectric sensor 3 to a portion having a large strain in the target vibration mode.

As an advantage of the method of detecting strain, by detecting the strain at the position where the piezoelectric sensor 3 is installed, only deformation in the target vibration mode can be detected, and the influence of external vibration can be reduced. can give.

FIG. 5 shows an enlarged view of the piezoelectric actuator 4 used in the first embodiment. The structure of the piezoelectric actuator 4 is similar to that of the piezoelectric sensor 3, and a plate-shaped piezoelectric element is attached to the structure plate 6 using an adhesive 9. By disposing the piezoelectric actuator 4 where the curvature of bending deformation increases in the target vibration mode, the piezoelectric actuator 4 is likely to cause distortion of the structural plate 6 and is highly effective in reducing vibration.

While active vibration control devices have higher vibration control capability than passive vibration control devices, they are also subject to large variations due to changes in the frequency of vibrations targeted for vibration control. There is also a problem that it is not suitable. On the other hand, in this embodiment, in the controller 5 that generates a control signal 8 for determining the driving force generated in the piezoelectric actuator 4 by the signal from the piezoelectric sensor 3, the internal parameters are adjusted in accordance with the vibration characteristics of the target structural plate 6. Take a way to change. That is, the controller 5 changes the center frequency and gain of the digital filter of the feedback circuit in the controller 5 in response to changes in the frequency and magnitude of the target vibration detected by the piezoelectric sensor 3 to change the mode of the control signal 8. Thus, the control signal 8 from which the influence of the variation is automatically removed can be created. As a result, even if the vibration characteristics of the target structural plate 6 change, an optimum vibration damping performance can be obtained following the change. Further, by adopting this configuration, it becomes possible to correct even if the vibration characteristics of the object are different from those at the time of design due to manufacturing variations of the storage device 2, and it is possible to save time for redesign and adjustment. The cost when introducing the active vibration control device can be reduced.

FIG. 6 shows a method of changing the control characteristic of the controller 5 in response to the change of the vibration characteristic of the object.

In step 601, the response is measured by the sweep input sensor by the plate-like piezoelectric actuators 4a to 4c. In step 602, it is determined whether frequency / gain <specified value. If the frequency / gain is less than the specified value, in step 603, the filter is changed according to the difference. On the other hand, it is determined whether frequency / gain <specified value. If the frequency / gain is smaller than the specified value, this flow is finished as it is. That is, in this flow, a sinusoidal wave input is applied to the plate-like piezoelectric actuator 4 to perform vibration, sweeping around the target frequency, and the peak frequency and gain of the target vibration are within a predetermined range. For example, the digital filter inside the controller 5 is not changed. When the specified range is exceeded, the center frequency and gain of the digital filter are changed so as to reduce the difference according to the difference from a preset value. By doing in this way, the high damping capability which an active damping device has can be exhibited effectively, even if the vibration characteristic of object shifts.

This embodiment solves the problem that the cost of conventional active vibration control devices is high by reducing the cost of parts for sensors and actuators, while adjusting the controller characteristics with respect to the target vibration characteristics. In this way, it is possible to reduce the introduction cost and to solve the design difficulties that must be specially designed for the target. Compared to widely used passive vibration control devices, active vibration control devices that are difficult to introduce from the viewpoint of cost and design man-hours despite their high vibration control performance can be applied to a wide variety of devices. It will become apparent with reference to this embodiment that this is possible.

In the present embodiment, the RAID device which is an information storage device has been described as an example, but it goes without saying that it can be applied to other types of devices.

Example 2 will be described. A description will be given centering on differences from the first embodiment. That is, description of the same parts as those in the first embodiment is omitted. FIG. 7 shows a second embodiment of the present invention. The acceleration sensor 10 is used as vibration detection means. In this case, since external vibration is picked up, noise processing is required. Therefore, in this embodiment, in order to compensate for the stability and damping performance of the control system, the high-pass filter 11 is set before the controller 5, and other vibration components that become noise from the acceleration sensor 10 are passed through the filter. To reduce the influence of external vibration. The reason why the high-pass filter is used is that the vibration component from the outside generally has a lower frequency than the vibration mode of the target storage device 2.

The advantage of using the acceleration sensor 10 is that it is not easily affected by temperature or the like. Moreover, vibration can be detected effectively by installing the acceleration sensor 10 where the vibration amplitude of the structural plate 6 is large. Since the location where the vibration amplitude is large can be measured relatively easily by using various displacement meters, speedometers, and accelerometers, the active vibration damping device of the present invention is used to reduce vibrations after confirming the vibration state of the actual machine. There is also an advantage that workability is high when applying. Further, as in the first embodiment, as the vibration generating means, by using the plate-like piezoelectric actuator 4, it directly acts on the deformation state of the vibration mode and reduces the vibration amplitude.

FIG. 8 shows an enlarged view of the piezoelectric sensor 3 in the third embodiment of the present invention. In vibration detection for detecting strain, it is conceivable that the output is affected by changes in environmental temperature. In order to compensate for this, the temperature sensor 12 is provided, and thereby the output of the piezoelectric sensor 3 is compensated, whereby the influence of temperature can be suppressed. Other configurations are the same as those of the first embodiment.

In the first embodiment, a change in the target vibration characteristic due to a temperature change is regarded as a variation and compensated by a characteristic change in the feedback circuit of the controller 5. On the other hand, when there is a change in the characteristics of the piezoelectric sensor 3 itself due to a temperature change, it is not possible to distinguish between a change in the output signal due to this and a change in the output signal due to a change in the target temperature characteristic. Therefore, this problem can be solved by arranging the temperature sensor 12 in the vicinity of the piezoelectric sensor 3 and correcting the output of the piezoelectric sensor 3 with respect to the temperature at this portion according to the temperature correction map defined in advance. it can.

Here, the first to third embodiments are summarized as follows. In the active vibration damping device, the cost as the vibration damping device is high unless the application target is mass-produced, and further, the frequency change of the target vibration is increased. However, in this example, the vibration state of the target can be determined by providing multiple vibration detection means that have the same shape and properties according to the same standard. While better measurements can be made, productivity can be improved and costs can be reduced. Also, the driving force that can efficiently reduce the vibration of the target is determined by predetermining the number and arrangement of the vibration generating means according to the characteristics of the target by aligning the shape and performance of the vibration generating means according to the same standard. Can be generated. Furthermore, the cost can be reduced for the same reason as described above.

In addition, in the case where the target structure is a substantially box-shaped housing or the like, the vibration generating means for suppressing the vibration is more improved than the case where the vibration detecting means and the vibration generating means are disposed at the same place. It can be placed in an efficient position. In general, in the case of a roughly box-shaped structure, the vibration mode presents an overall complex aspect, so a position where the amplitude of the target vibration can be detected effectively and a driving force applied to suppress the vibration are applied. This is because the position suitable for this is not always the same.

Furthermore, when an acceleration sensor is used as the vibration detection means, noise from the outside is also picked up because it picks up vibrations from the outside. In this embodiment, the strain at the position installed on the vibration detection means is detected. Thus, only the deformation in the target vibration mode can be detected, and the influence of external vibration can be reduced. Further, the vibration generating means also directly affects the deformation state of the vibration mode by using means such as a plate-like piezoelectric element that generates strain at the target position, and reduces the vibration amplitude.

In the vibration detection means for detecting strain, the output may be affected by changes in environmental temperature. In order to compensate for this, the temperature detection means is provided, and thereby the output of the vibration detection means is compensated, whereby the influence can be suppressed.

A more preferable method is that the control means for generating a control signal for determining the driving force to be generated by the vibration generating means based on the signal from the vibration detecting means, the frequency and magnitude of the vibration of the object detected by the vibration detecting means. By changing the mode of the control signal that determines the driving force of the vibration generating means in response to the change in the control signal, it is possible to automatically create a control signal from which the influence has been removed. Furthermore, by adopting this configuration, even if the target vibration characteristics are different from those at the time of design due to variations, correction can be performed, and costs at the time of introduction can be reduced.

Note that the present invention is not limited to the first to third embodiments described above, and includes various modifications. For example, the first to third embodiments described above are described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 Active damping device 2 Memory | storage device 3a, 3b Piezoelectric sensor 4a, 4b, 4c Plate-shaped piezoelectric actuator 5 Controller 6 Structure board 7 Voltage output 8 Control signal 9 Adhesive material 10 Acceleration sensor 11 High pass filter 12 Temperature sensor 13 Electrode 14 Signal line

Claims (6)

1. Vibration detecting means provided on a part of the structure for detecting vibration; vibration generating means for generating distortion in a part different from the part of the structure; and the vibration in accordance with a signal from the vibration detecting means Control means for generating a control signal for determining the driving force of the generating means, and the driving force of the vibration generating means is changed with respect to changes in the frequency and magnitude of the vibration of the object detected by the vibration detecting means. An active vibration damping device characterized by changing a mode of a control signal to be determined.
   
2. 2. The structure according to claim 1, wherein the structure includes a plurality of vibration detection means, a plurality of vibration generation means, a signal from the plurality of vibration detection means is sent to the control means, and a control signal from the control means is transmitted. An active vibration damping device that is sent to the plurality of vibration generating means.
   
3. 2. The vibration according to claim 1, wherein the target is a substantially box-shaped structure, and vibration detecting means for detecting the vibration of the target is installed in a portion where the vibration amplitude of the target structure is large to cause distortion in a part of the target. An active vibration damping device characterized in that the generating means is installed near a place where the curvature of a target vibration mode is maximum.
   
4. The vibration detection unit according to claim 1, wherein the vibration detection unit detects strain of a part of the target, further includes a temperature measurement unit, and the control unit generates the vibration according to the temperature of the target measured by the temperature measurement unit. An active vibration damping device characterized in that the mode of a control signal for determining the driving force of the means is changed.
   
5. 2. The vibration detection unit according to claim 1, wherein the vibration detection unit is configured as a plurality of identical detection units that detect a strain of a part of the target, and the vibration generation unit generates a plurality of strains at a part of the target that is a different location. An active vibration control device characterized by being configured as the same generating means.
   
6. Vibration is detected by a vibration detection means provided in a part of the structure, and the change in the frequency and magnitude of the target vibration detected by the vibration detection means is changed to a part different from the part in the structure. An active damping method in which the control means supplies a control signal to the vibration generating means so that the vibration generating means causes distortion.

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