JP2009185918A - Vibration damping device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damping device performing a function of damping the vibration of the same structure for forcible vibration components and natural vibrion components. <P>SOLUTION: The device is arranged adjacent to an object structure for damping the vibration of the object structure. It comprises a countermeasure device 20 including a vibrator 21 whose displacement to a predetermined direction is allowed and a driving means 25 for applying driving force directly to the vibrator 21, a sensor 40 for detecting the vibration of the object structure, and a controller 30 for controlling the operation of the driving means 25 in accordance with the vibration of the object structure detected by the sensor 40. The controller 30 extracts the forcible vibration component and the natural vibration component from the vibration of the object structure, sets driving conditions (a) of the countermeasure device corresponding to the forcible vibration component, sets driving conditions (b) of the countermeasure device corresponding to the natural vibration component, and controls the driving means in driving conditions (c) that the driving conditions (a) and the driving conditions (b) are added together. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vibration damping device, and more particularly, to a vibration damping device effective when a forced vibration having a frequency different from a resonance frequency occurs in a building, a facility, or the like.

Among the vibration control devices for structural vibrations, various devices and types have been proposed as devices for natural vibrations. For example, TMD (Tuned Mass Damper) and active devices that apply control force to it are put into practical use and commercialized.
The structural vibration damping device that is widely put into practical use produces an effect equivalent to reducing the resonance magnification in the structural vibration characteristics by vibrating the device in synchronization with the natural vibration of the target structure. On the other hand, a structural vibration damping device that has been put into practical use is not effective for forced vibrations that deviate from the natural frequency.

Thus, for example, Patent Document 1 proposes a damping device for forced vibration.
Patent Document 1 discloses that when a vibration control device installed in the vicinity of a vibration source activates a vibration sensor, a phase extraction unit, and a frequency extraction unit, the phase extraction unit and the phase extraction unit are detected from the vibration of the vibration source detected by the vibration sensor. The frequency extraction means extracts the phase and frequency of the vibration. And a frequency and a phase are adjusted by the action | operation of a control apparatus, and a vibration exciter is operated. Since the vibration exciter is attached to the vibration system, the vibration is transmitted to the vibration system by the operation of the vibration exciter, and the mass element is vibrated in the vertical direction.
Patent Document 1 assumes that the vibration frequency of the vibration source is limited to a predetermined range, and the resonance frequency of the vibration system is set within a substantially range of the vibration frequency. When approaching the resonance frequency of the vibration system, the vibration system vibrates greatly and generates a large excitation force (inertial force) that matches the vibration frequency of the shaker. The vibration of the vibration exciter is the same as the vibration frequency of the vibration source, and the vibration of the vibration source and the vibration of the vibration system are adjusted to have opposite phases. It is added to the installation surface with the opposite phase to the vibration. As a result, it is possible to generate a large excitation force by greatly vibrating the vibration system with a relatively small excitation force generated by the vibration exciter. Propagation will be prevented.

JP 2005-221054 A

Patent Document 1 discloses a vibration damping device having the same natural frequency as a forced frequency in order to save excitation energy. Therefore, although the countermeasure device drive power can be small, phase control is difficult. Since the step vibration (disturbance) due to “vertical glue”, which is a problem in Patent Document 1, is not performed at a constant rhythm, the phase difference of the response to the force changes. As a result, the portion of the vibration system that is unable to follow the fluctuating disturbance among the vibration force of the vibration system by the vibration damping device of Patent Document 1 does not work as a vibration damping effect, becomes a new vibration force, and the transient of the natural vibration component Produces a response.
Further, Patent Document 1 exhibits a vibration reduction effect for the forced vibration component. However, when vibration reduction is required for the natural vibration component of the same structure, a countermeasure device for the natural vibration component is separately provided. It becomes necessary, and the space and cost for installing the two types of countermeasure devices become problems.
The present invention has been made based on such a technical problem, and provides a vibration damping device that exhibits a damping function for a forced vibration component and a natural vibration component with a single device for the same structure. The purpose is to do.

In referring to the present invention, a damping mechanism for the natural vibration of a structure will be described with reference to FIG.
As shown in the upper part of FIG. 1, when a disturbance having a natural frequency of a structure is input and a countermeasure device having the same natural frequency as the natural frequency of the structure is installed, the structure is shaken by the disturbance. Since this vibration is resonant, the phase is delayed by 90 °, and the structure response displacement is delayed by 90 ° with respect to the disturbance as shown in the middle part of FIG. At this time, the structure response acceleration advances by 180 ° with respect to the structure response displacement. When the structure response acceleration is α, it can be considered that an inertial force of −mα is applied to a countermeasure device that is installed on the structure and is shaken when the structure is shaken. Here, m is the mass of the countermeasure device movable vibrator.
Since the countermeasure device for the natural vibration is adjusted so as to have the same natural frequency as the structure natural frequency, the response displacement of the countermeasure device when the force of -mα is applied is as shown in the lower part of FIG. In addition, it is delayed by 90 ° with respect to -mα. At this time, the countermeasure device response acceleration advances by 180 ° with respect to the countermeasure device response displacement.
Since the countermeasure device moves 90 ° behind the structure response, it works as a structure damping effect. Alternatively, when the way of thinking is changed, a device inertia force −mβ (where β is a response device response acceleration) generated by the response acceleration of the countermeasure device is input to the structure, and the disturbance is canceled by the device inertia force.

Next, as shown in the upper part of FIG. 2, when a disturbance other than the natural frequency of the structure is input, the structure is shaken at the same frequency as the forced frequency. Since this fluctuation is not resonance, the phase delay of the structure response displacement is not 90 ° as shown in the middle part of FIG. And a countermeasure apparatus is shaken with the shake of a structure. Since this shaking is resonance, the phase of the countermeasure device response displacement is delayed by 90 ° from the structure response.
The countermeasure device works as a damping effect of the structure because the countermeasure device moves so as to be delayed by 90 ° from the response of the structure. However, since the response of the countermeasure device is a frequency different from the natural frequency, there is almost no response reduction effect due to the application of damping.

  The vibration damping device of the present invention with respect to the above is disposed in the vicinity of the target structure and suppresses vibration generated in the target structure, and the vibration body allowed to be displaced in a predetermined direction and the vibration body A countermeasure device including a driving unit that directly applies a driving force to the vibrating body, a sensor that detects vibration of the target structure, and controls the operation of the driving unit based on the vibration of the target structure detected by the sensor. The controller extracts the forced vibration component and the natural vibration component from the vibration of the target structure, sets the driving condition a of the countermeasure device corresponding to the forced vibration component, and corresponds to the natural vibration component The driving means b is set, and the driving means is controlled by the driving condition c obtained by adding the driving condition a and the driving condition b.

  In the vibration damping device of the present invention, the controller simulates the response due to the forced vibration component of the countermeasure device when the driving means is driven under the driving condition a, and sets the driving condition a in consideration of the result of the simulation. Is preferred. Further, in the vibration damping device of the present invention, the controller simulates a response due to the natural vibration component of the countermeasure device when the driving means is driven under the driving condition b, and sets the driving condition b in consideration of the simulation result. More preferably.

According to the present invention, the drive condition a corresponding to the forced vibration component and the drive condition b corresponding to the natural vibration component are set, and the drive means of the countermeasure device is the drive condition c obtained by adding the drive condition a and the drive condition b. Therefore, it is possible to exert a damping function in consideration of both the forced vibration component and the natural vibration component with the same device with respect to the same structure.
Further, in the vibration damping device of the present invention, the simulation result of the response due to the forced vibration component of the countermeasure device when the driving means is driven under the driving condition a, and further, the inherent characteristic of the countermeasure device when the driving means is driven under the driving condition b By setting the driving condition a and the driving condition b in consideration of the simulation result of the response due to the vibration component, it is possible to obtain a more accurate damping effect.

Hereinafter, the present invention will be described in detail based on the embodiments shown in FIGS.
The vibration damping device 10 according to the present embodiment is disposed in the vicinity of a target structure (for example, a dome stadium, a concert hall) to which forced vibration is applied as a disturbance. As shown in FIG. The controller 30, the target structure vibration sensor 40a, and the countermeasure device vibration sensor 40b are provided. In the present embodiment, it is assumed that the frequency of forced vibration as disturbance is known and constant. In the case of “vertical glue”, the frequency is 2 to 3 Hz.
The countermeasure device 20 includes a vibrating body 21 having a predetermined mass and a leaf spring 22 that defines the moving direction of the vibrating body 21 as components of the vibration system. One end of each leaf spring 22 is fixed to a pedestal 23 having a U-shaped cross section installed on the installation surface A. Further, the other end of each leaf spring 22 is fixed to the upper and lower ends of the vibrating body 21. Therefore, the vibrating body 21 can be displaced in the vertical (vertical) direction as indicated by an arrow in FIG. 3, but the displacement in the horizontal (horizontal) direction is restricted. Note that the natural frequency of the countermeasure device 20 can be adjusted by changing the number of leaf springs 22.

An actuator 25 is disposed between the gantry 23 and the vibrating body 21. The actuator 25 drives the vibrating body 21 in the vertical direction according to a command from the controller 30. The actuator 25 may be of any form as long as it drives the vibrating body 21 in the vertical direction. For example, a VCM (Voice Coil Motor) composed of a combination of an electromagnetic coil and a permanent magnet can be used.
A coil spring 24 is disposed between the gantry 23 and the vibrating body 21. The coil spring 24 supports the vibrating body 21 by being compressed by the weight of the vibrating body 21. When the vibrating body 21 is displaced in the vertical direction, a force corresponding to the amount of displacement is applied to the vibrating body 21.

As shown in FIG. 4, the controller 30 includes an FFT (Fast Fourier Transform) device 31, a forced vibration countermeasure controller 32, and a natural vibration countermeasure controller 33. The fast Fourier transform (FFT) is an algorithm that calculates a discrete Fourier transform (DFT) at high speed on a computer, as is well known.
The controller 30 obtains vibration information including the displacement and speed of the target structure from the target structure vibration sensor 40 installed in the target structure. This vibration information includes vibration information due to the vibration of the countermeasure device 20.
The controller 30 can separate and extract the vibration information acquired from the target structure vibration sensor 40 into a forced vibration component and a natural vibration component by performing an FFT process. Here, for the forced vibration component, a frequency having the largest response amplitude is extracted. In the present invention, this forced vibration component is defined as a main forced vibration component.

  FIG. 5 shows an example of the result of performing the FFT process. In FIG. 5, the frequency f1 corresponds to the main forced vibration component, and f2 corresponds to the natural vibration component. f2 (natural vibration component) is known information obtained in advance for the target structure. As shown in FIG. 5, the response amplitude is A1 (m) and the response phase is B1 (deg) for the main forced vibration component, the response amplitude is A2 (m) and the response phase is B2 (deg) for the natural vibration component. ) Can be extracted by FFT processing.

  In FIG. 4, the forced vibration countermeasure controller 32 generates a control command for the countermeasure device 20 based on the main forced vibration component obtained by the FFT processing. Further, the natural vibration countermeasure controller 33 generates a control command for the countermeasure device 20 based on the natural vibration component. The controller 30 adds the control command generated by the forced vibration countermeasure controller 32 and the control command generated by the natural vibration countermeasure controller 33, and outputs the result as the driving force of the actuator 25.

Next, an operation procedure of the vibration damping device 10 will be described with reference to FIG.
For example, when a vertical slack occurs in a concert, the controller 30 acquires a response (vibration information) of the target structure measured by the target structure vibration sensor 40 (S101). The FFT unit 31 of the controller 30 performs frequency analysis by performing FFT processing on the acquired vibration information (S103). This result is, for example, as shown in FIG.
The controller 30 refers to the result of the FFT process and separates the main forced vibration component and the natural vibration component (S105). The main forced vibration component is sent to the forced vibration countermeasure controller 32, and the natural vibration component is sent to the natural vibration countermeasure controller 33.

  The forced vibration countermeasure controller 32 specifies, for example, that the main forced vibration component has the frequency f1 (Hz), the amplitude is A1 (m), and the phase is B1 (deg) (S107). The forced vibration countermeasure controller 32 obtains a disturbance from this main forced vibration component by back calculation. Disturbance refers to stepping vibration caused by “vertical glue”, for example, as described above. In order to obtain the disturbance by back calculation, the forced vibration countermeasure controller 32 has, for example, a table shown in FIG. The table shown in FIG. 7 describes the amplitude ratio (m / N) and phase difference (deg) for each vibration frequency of the target structure. For example, when the frequency is f1, the response when the disturbance is 1N is a1 (m), and the phase is shifted by b1 (deg) from the disturbance. If the amplitude ratio (m / N) and the phase difference (deg) for each vibration frequency of the target structure are calculated in advance for the target structure and stored in the memory device of the forced vibration countermeasure controller 32. Good.

The forced vibration countermeasure controller 32 identifies the main forced vibration components (frequency: f1 (Hz), amplitude: A1 (m), phase: B1 (deg)), and then refers to the above-described table to reduce the disturbance. Obtained by reverse calculation (S109). When main forced vibration components are frequency: f1 (Hz), amplitude: A1 (m), and phase: B1 (deg), the disturbance amplitude and phase are A1 / a1 (N) and B1-b1 (deg), respectively. ).
Next, the forced vibration countermeasure controller 32 sets a countermeasure force for canceling the disturbance obtained by the reverse calculation (S111). This countermeasure force is set as a vibration having the same amplitude as the disturbance amplitude and having a phase shifted by 180 °. That is, the countermeasure force is set to frequency: f1 (Hz), amplitude: β * A1 / a1 (N), and phase: B1-b1-180 (deg). In addition, (beta) is an arbitrary coefficient and is set in the range of 0.0-1.0. 1.0 means that a countermeasure force for completely canceling the disturbance is given, and 0.0 means that a countermeasure force is not given. However, normally, when β is set to 1.0, there arises a problem of control stability, and a large motor power is required. Therefore, a value less than 1.0 is set.

Assuming that the countermeasure device 20 is driven with the countermeasure force determined as described above, it is necessary to consider the vibration caused by the driving of the countermeasure device 20 in order to calculate the actual countermeasure force.
That is, the simulation is performed by adding the set countermeasure force (amplitude: β * A1 / a1 (N), phase: B1-b1-180 (deg)) and the main forced vibration component separated and extracted in S105. Is performed (S113). The main forced vibration components to be added can be A1 and B1 in the case of f1 (Hz). However, all the target frequency bands of the forced vibration component may be included without fixing the frequency to f1 (Hz). For example, when a frequency band of 2 to 3 Hz is dominant as disturbance, the amplitude and phase corresponding to disturbance fluctuation within the range can be obtained. For example, in the disturbance of a concert hall, the frequency fluctuates because a person is the excitation source. This is due to fluctuations according to the frequency of the music and variations in human movement. For this reason, it is preferable that a certain disturbance frequency range is assumed so that it can be dealt with.
As a result, the force to be input to the countermeasure device model simulating the countermeasure device 20 is the sum of the inertial force input due to the movement of the installation base of the countermeasure device 20 and the force applied by the countermeasure device 20 itself as a control force. is there.
For example, assume that a constant disturbance having a frequency of 2.5 Hz has occurred. In this case, if the countermeasure device 20 generates countermeasure force of the same amplitude and opposite phase so as to cancel this disturbance, the movement of the target structure stops. However, since constant disturbance continues, it is necessary to continue to apply countermeasures even if the movement of the structure response stops. Therefore, considering not only the response of the target structure but also the influence of the countermeasure force generated by itself, the original disturbance is estimated by the simulation of S113, and a constant countermeasure force is generated in accordance with the constant disturbance.

On the other hand, based on the natural vibration component, the natural vibration countermeasure controller 33 sets a countermeasure force for the natural vibration component (S115).
In the present embodiment, this countermeasure power is specified by skyhook control. Skyhook control means that if a damper (skyhook damper) is installed between the virtual wall in the absolute coordinate system and the target structure, the absolute acceleration response value of the target structure can be reduced. Is a control method that reproduces with a damper that is actually installed between the ground and the target structure.
In the case of the present embodiment, the product mα of the mass m of the vibration body 21 of the countermeasure device 20 and the absolute acceleration α of the vibration body 21 is the damper force. The countermeasure force (driving force) of the actuator 25 of the countermeasure device 20 necessary for that is set.
For example, when the damping coefficient C1 (N · s / m) that gives the necessary damping characteristics is set, the countermeasure force against the natural vibration component is amplitude: A2 / C1 (N), phase: B2-b2-180 °. Given in.

  As described above, when the countermeasure force for the main forced vibration component and the countermeasure force for the natural vibration component are set, these are added (S117). The countermeasure force for the main forced vibration component is amplitude: β * A1 / a1 (N), phase: B1-b1-180 (deg), and the countermeasure force for the natural vibration component is amplitude: γ * A2 / C1 (N) Since the phase is γ * B2-b2-180 (deg), the countermeasure force input to the actuator 25 of the countermeasure device 20 is set to the above total value.

  As described above, the vibration damping device 10 according to the present embodiment separates and extracts the main forced vibration component and the natural vibration component, and the countermeasure force corresponding to the main forced vibration component and the countermeasure corresponding to the natural vibration component. After each force is set, these are added together to determine the final countermeasure power. Therefore, according to the vibration damping device 10, the main forced vibration component and the natural vibration component are separated and extracted by a single device, and the countermeasure power corresponding to each component is set and then added. By providing the control logic, it is possible to take a vibration suppression measure for both the forced vibration component and the natural vibration component. Therefore, it is possible to save the installation space of the vibration suppression device 10 and to suppress an increase in installation cost.

The vibration damping device 10 uses a countermeasure device 20 configured to directly transmit the force of the actuator 25 to the vibrating body 21. Therefore, the countermeasure device 20 can exhibit a damping function against the countermeasure force obtained by adding the countermeasure force corresponding to the main forced vibration component and the countermeasure force corresponding to the natural vibration component. On the other hand, the vibration method using the rotating mass disclosed in Patent Document 1 cannot exhibit a vibration suppression function that follows the countermeasure force obtained by adding the above two types of countermeasure forces. Note that the countermeasure device 20 applicable to the present invention is not limited to the form in which the vibrating body 21 is supported by the leaf spring 22, and may be any countermeasure apparatus that directly transmits force to the vibrating body. For example, the device shown in FIG. 1 of Patent Document 2 or the device shown in FIG. 1 of Patent Document 3 can be applied as the countermeasure device of the present invention.
In the present embodiment, an example in which the vibrating body 21 is displaced in the vertical (vertical) direction has been described. However, the present invention is not limited to this, and any countermeasure device having a vibrating body that is displaced in the horizontal direction can be used. It can be applied to a countermeasure device having a vibrating body that is displaced in a direction that coincides with the vibration direction.

JP-A-2-296975 JP-A-6-288119

  In the above, the example in which the skyhook control is applied to the setting of the countermeasure force for the natural vibration component has been described. However, the present invention is not limited to this, and the setting of the countermeasure force for the natural vibration component can be performed by applying a known LQ control. It can be carried out. Hereinafter, this example will be described with reference to FIG. In FIG. 8, the same processes as those in FIG. 6 are denoted by the same reference numerals (S101 to S113, S117) as those in FIG.

In the case of LQ control, the countermeasure force against the natural vibration component is obtained using the state quantity xi with respect to the gain Ki that gives the control force. Here, Ki is a constant obtained as a parameter that gives a necessary damping constant as a coupled system of the target structure and the countermeasure device, and is determined in advance. It is the LQ control theory that the countermeasure force F = −ΣKi × xi is obtained by this constant (gain). This gain value is obtained by numerical analysis in consideration of the required vibration reduction effect and the like.
In the LQ control, the control force is obtained by using the respective state quantities (for example, displacement / speed) of the target structure and the countermeasure device 20, but in the case of the LQ control gain for the natural vibration component, the disturbance of the natural vibration component and the countermeasure force Considering the influence of the, it is designed to operate stably. On the contrary, the forced vibration countermeasure force applied to the countermeasure device 20 as a control force is a disturbance for the LQ control and contributes to destabilization. Therefore, it is desired to specify the response of the countermeasure device 20 excluding the forced vibration countermeasure force, which is a disturbance, but in actuality, only the response of the countermeasure device 20 to which the total countermeasure force is applied can be measured by the countermeasure device vibration sensor 40b. The response due to the natural vibration component is estimated by simulation. In the simulation of S117, as the force input to the countermeasure device 20, the resultant force of inertia force acting on the countermeasure device 20 due to the movement of the target structure and the countermeasure force obtained by the LQ control for the natural vibration component is used as the countermeasure device model. give.

It is a figure for demonstrating the damping effect when the disturbance of a natural frequency is input into the structure. It is a figure for demonstrating the damping effect when the disturbance of a forced frequency is input into the structure. It is a figure which shows the structure outline of the damping device which concerns on this embodiment. It is a figure which shows the control outline | summary of the damping device which concerns on this embodiment. It is a figure which shows an example of the result of having performed the FFT process on the vibration detected by the sensor. It is a flowchart which shows the process sequence of the controller which concerns on this embodiment, and has shown the example which sets the drive condition corresponding to a natural vibration component by skyhook control. It is a figure which shows an example of the table which describes the amplitude ratio for every vibration frequency of a target structure, and a phase difference which a controller hold | maintains. It is a flowchart which shows the process sequence of the controller which concerns on this embodiment, and has shown the example which sets the drive condition corresponding to a natural vibration component by LQ control. The

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Damping device, 20 ... Countermeasure device, 21 ... Vibrating body, 25 ... Actuator, 30 ... Controller,
31 ... Fast Fourier Transformer, 32 ... Forced vibration countermeasure controller, 33 ... Natural vibration countermeasure controller,
40a ... object structure vibration sensor, 40b ... countermeasure device vibration sensor

Claims (3)

A device that is disposed in proximity to a target structure and that suppresses vibrations generated in the target structure,
A countermeasure device including a vibrating body that is allowed to be displaced in a predetermined direction and a driving unit that directly applies a driving force to the vibrating body;
A sensor for detecting vibration of the target structure;
A controller for controlling the operation of the driving means based on the vibration of the target structure detected by the sensor,
The controller is
Extracting a forced vibration component and a natural vibration component from the vibration of the target structure,
Set the driving condition a of the countermeasure device corresponding to the forced vibration component,
Set the driving condition b of the countermeasure device corresponding to the natural vibration component,
A vibration damping device characterized in that the driving means is controlled under a driving condition c obtained by adding the driving condition a and the driving condition b. The controller is
Simulating the response by the forced vibration component of the countermeasure device when the driving means is driven under the driving condition a,
The vibration damping device according to claim 1, wherein the driving condition a is set in consideration of a result of the simulation. The controller is
Simulating the response due to the natural vibration component of the countermeasure device when the driving means is driven under the driving condition b,
The vibration control device according to claim 1, wherein the driving condition b is set in consideration of a result of the simulation.

Images