Vibration control device

Abstract

To provide a vibration control device having a simple structure, and capable of obtaining a high vibration reduction effect with a small mass.SOLUTION: A vibration control device comprises: a lower frame; an upper frame having one end rotatably supported on the lower frame, and extending horizontally; an elastic member supporting the other end of the upper frame on the lower frame; a movable mass supported on the upper frame, and slidable horizontally; a drive mechanism that displaces the position of the movable mass; a vibration sensor that is provided on the lower frame, and detects vibration; and a control unit that calculates the position of the movable mass suitable for vibration control based on a dominant frequency obtained from a detection signal of the vibration sensor, and controls the drive mechanism.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vibration damping device that suppresses vibration of a structure. [Background technology]

[0002] The floors of a building vibrate (vertical vibration) due to disturbances. Disturbances include, for example, vibrations due to earthquakes, vibrations due to walking, and vibrations propagating from inside or outside the building. A vibration control device is known as a device for suppressing such floor vibrations. For example, a vibration control device has been disclosed in which a compression coil spring that springs in the vertical direction and a damping means that damps the force in the vertical direction are provided together, a mass (weight) is placed on these, and a damping means is further provided between the mass and the floor (see Patent Document 1). Also, an active floor vibration control device has been disclosed that includes a sensor for detecting vibrations of a floor to be damped, a controller for determining an actuator operation amount that can reduce vibrations and solid-borne sound from a detection signal by the sensor and a dynamic characteristic model of the vibration control target, and controlling the actuator, and an actuator that is driven and controlled by the controller to generate a vibration force (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-252253 [Patent Document 2] JP 2005-276118 A Summary of the Invention [Problem to be solved by the invention]

[0004] The vibration control device described in Patent Document 1 is a tuned mass damper (TMD) that tunes the mass and coil to the natural vibration frequency of the floor or beam, so the mass needs to be sufficiently large to achieve a high vibration reduction effect, which inevitably leads to a large size and weight, resulting in high costs. Therefore, the mass of the mass is usually designed to be about 1 to 3% of the mass of the target object, which causes a problem that a sufficient vibration reduction effect cannot be obtained. The vibration control device described in Patent Document 2 is an active mass damper (AMD) that detects vibration with a sensor and dynamically moves the mass with an actuator, and since it is necessary to precisely control the actuator to cancel the acting excitation force, the high cost is also a problem.

[0005] In view of the above problems, one object of the present invention is to provide a vibration damping device that has a simple structure and is capable of achieving a high vibration reduction effect with a small mass. [Means for solving the problem]

[0006] A vibration control device according to one embodiment of the present invention comprises a lower frame, an upper frame having one end rotatably supported on the lower frame and extending horizontally, an elastic member supporting the other end of the upper frame on the lower frame, a movable mass supported on the upper frame and slidable horizontally, a drive mechanism for displacing the position of the movable mass, a vibration sensor provided on the lower frame for detecting vibrations, and a control unit for calculating a position of the movable mass suitable for vibration control based on a dominant frequency obtained from the detection signal of the vibration sensor and controlling the drive mechanism.

[0007] In one embodiment of the present invention, the upper platform may have a cantilever structure supported in a cantilever state at a freely rotating fulcrum.

[0008] In one embodiment of the present invention, the control unit may have a function of controlling the drive mechanism to displace the position of the movable mass so that the dominant frequency coincides with the natural vibration frequency of the vibration damping device.

[0009] In one embodiment of the present invention, the mass of the movable mass may be less than 0.1 to 3% of the mass of the object to be damped.

[0010] In one embodiment of the present invention, the drive mechanism may be composed of an actuator or a linear motor. Effect of the Invention

[0011] According to one embodiment of the present invention, the position of the movable mass suitable for vibration control is calculated based on the dominant frequency obtained from the detection signal of the vibration sensor, and the position of the movable mass is controlled by a drive mechanism, thereby making it possible to obtain a high vibration reduction effect while keeping the mass of the movable mass small. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing a configuration of a vibration damping device according to an embodiment of the present invention; [Diagram 2] 4 is a graph showing the relationship between the position of a movable mass and the natural vibration frequency in a vibration damping device according to an embodiment of the present invention. [Diagram 3] 4 is a graph illustrating the vibration reduction effect of a vibration control device (difference in damping due to a damping device). [Figure 4] 4 is a graph illustrating the vibration damping effect of the vibration damping device (difference in attenuation due to the natural vibration frequency of the vibration damping device). [Diagram 5] 1 is a diagram showing an example of the structure of a vibration damping device according to an embodiment of the present invention; [Figure 6] 5 is a flowchart showing an example of a processing flow for a pre-shipment inspection of a vibration damping device according to an embodiment of the present invention. [Figure 7] 5 is a schematic diagram for explaining the contents of a pre-shipment inspection process for a vibration damping device according to an embodiment of the present invention. FIG. [Figure 8] 5 is a schematic diagram for explaining the contents of a pre-shipment inspection process for a vibration damping device according to an embodiment of the present invention. FIG. [Figure 9]5 is a flowchart illustrating an example of a process flow when a vibration damping device according to an embodiment of the present invention is installed on a vibration damping target. [Figure 10] 5A and 5B are schematic diagrams illustrating the contents of a process when a vibration damping device according to an embodiment of the present invention is installed on a vibration damping target. [Figure 11] 5 is a flowchart illustrating an example of a processing flow when a vibration damping device according to an embodiment of the present invention is operating. [Figure 12] 5A and 5B are schematic diagrams illustrating the contents of a process when a vibration damping device according to an embodiment of the present invention is installed on a vibration damping target. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different aspects, and should not be interpreted as being limited to the description of the embodiments exemplified below. In the drawings, the width, thickness, shape, etc. of each part may be shown schematically compared to the actual aspect in order to make the explanation clearer, but it is merely an example and does not limit the interpretation of the present invention. In this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals (or reference numerals with A, B, etc. added after the numerals) and detailed explanations may be omitted as appropriate. Furthermore, the letters "first" and "second" added to each element are convenient marks used to distinguish each element, and have no further meaning unless otherwise explained.

[0014] 1 shows the configuration of a vibration damping device 100 according to one embodiment of the present invention. The vibration damping device 100 is a device that reduces disturbances, such as vertical vibrations of a floor caused by walking or equipment inside a building. The vibration damping device 100 has a cantilever-type vibration system in which an upper frame 104 is supported in a cantilever state on a lower frame 102 at a freely rotating fulcrum.

[0015] In addition, the vibration control target of the vibration control device 100 is not limited to a floor, but a beam can also be the vibration control target. In the following, the floor or beam that is the vibration control target will be called the "vibration control target", and the vibration control target can be read as the "floor" or the "beam", etc.

[0016] The upper base 104 has a structure extending in the horizontal direction, with a first end S1 supported by a rotatable fulcrum 108 and a second end S2 on the opposite side of the first end S1 supported by an elastic member 110 on the lower base 102. Note that in this embodiment, "rotation" refers not only to rotation in one direction but also to rotation in both forward and reverse directions. A movable mass 106 is placed on the upper base 104 and is movable in the horizontal direction. The movable mass 106 is adjusted by a drive mechanism 112.

[0017] The vibration damping device 100 has a vibration sensor 116, which is installed at at least one location on the lower frame 102. The vibration sensor 116 may also be additionally installed on the movable mass 106. The vibration measured by the vibration sensor 116 is output to a control unit 118. The control unit 118 has a function of determining the predominant frequency of the vibration of the object to be damped from the vibration data detected by the vibration sensor 116, calculating the optimal position of the movable mass 106 from the vibration data, and outputting a signal to the driving mechanism 112 to control the position of the movable mass 106.

[0018] The natural vibration frequency of the vibration damping device 100 changes depending on the position of the movable mass 106. Specifically, the natural vibration frequency of the vibration damping device 100 becomes higher as the movable mass 106 approaches the first end S1, and becomes lower as the movable mass approaches the second end S2. Fig. 2 is a diagram for explaining the change in the natural vibration frequency with respect to the position of the movable mass of a vibration damping device having a cantilever-type vibration system in which a movable mass is used, and shows in a graph the relationship of the natural vibration frequency with respect to the position from the fulcrum of the movable mass.

[0019] As shown in the legend and the inserted diagram of the graph in Figure 2, the vibration control device to be evaluated has a mass of the upper frame w0 = 10 kg, a mass of the movable mass wd of 40 kg, a spring constant ks of the spring (elastic body) of 26.6 kg / cm, a distance Ls to the spring (elastic member) of 40 cm, and a distance Lo to the center of gravity of the upper frame of 20 cm. As shown in the graph in Figure 2, it can be seen that the natural vibration frequency decreases as the distance Ld to the movable mass increases. In addition, the natural vibration frequency of the vibration control device can be adjusted by the mass of the movable mass, the spring constant and mounting position of the spring (elastic member), and the adjustment range can be expanded by changing the length of the upper frame.

[0020] For example, in terms of damping floor vibration, if the natural vibration frequency of the vibration damping device 100 matches the natural vibration frequency of the floor or the predominant frequency of the excitation force acting on the floor, it is possible to suppress the floor vibration to a very low level. Therefore, the vibration damping device 100 measures the floor vibration with the vibration sensor 116, calculates the natural vibration frequency of the floor or the predominant frequency of the excitation force of the acting disturbance, and adjusts the position of the movable mass 106 so that the natural vibration frequency of the vibration damping device 100 matches this value. The adjustment of the movable mass 106 is performed by the functions of the control unit 118 and the drive mechanism 112, as described above.

[0021] Figure 3 shows the acceleration transmission characteristics of a floor on which a vibration control device is installed. In the graph shown in Figure 3, the horizontal axis shows the ratio of the dominant frequency of the disturbance to the natural vibration frequency of the floor, and the vertical axis shows the ratio of the floor acceleration to the disturbance excitation force. Note that the floor weight is 10 ton, the mass weight of the vibration control device is 0.02 ton, and the natural vibration frequency of the vibration control device is the same as the natural vibration frequency of the floor.

[0022] As shown in the graph in Figure 3, when there is no vibration control device, the acceleration transmission characteristics of the floor are such that the vibration is at its maximum (curve <1> ) Conventional tuned mass dampers (TMDs) have a damping device (damper) attached, and by optimizing the damping amount of the damping device (damper), the damping characteristics are adjusted to be relatively flat even if the dominant frequency of the disturbance fluctuates (curve <4> ) In other words, the curve shown in Figure 3 <4> In the figure, the same vibration reduction effect is obtained at the position B1 of the resonance frequency and at the position B2 shifted from the resonance frequency. On the other hand, if the damping amount of the damper is larger than the optimal value, a sufficient vibration reduction effect cannot be obtained (curve <5> ), if the damping amount is smaller than the optimum value, the vibration at the resonance frequency becomes small, and two peaks appear at frequencies before and after the resonance frequency, impairing the flat characteristics (curve <3> ).

[0023] On the other hand, if the damping amount of the damping device (damper) is set to zero, a valley is formed at the resonance frequency, and the vibration can be minimized, but the peaks that appear at frequencies before and after the resonance frequency become large (curve <2> In this way, when the natural vibration frequency of the vibration control device is constant, and the predominant frequency of the disturbance and the natural vibration frequency of the floor coincide, a large vibration reduction effect can be achieved, but when the predominant frequency of the disturbance or the natural vibration frequency of the floor changes, the vibration reduction effect can be greatly reduced.

[0024] If we can change the natural vibration frequency of the vibration control device in response to such characteristics, as shown in Figure 4, we can change the position where the vibration reduction effect is maximized in response to disturbance. In other words, Figure 4 shows the case where the natural vibration frequency of the vibration control device and the natural vibration frequency of the floor are resonating (curve <30> ), when the natural vibration frequency of the vibration control device is 5% lower than the floor natural vibration frequency, the position of the valley where the vibration reduction effect is maximum shifts to the left (the side where the dominant frequency of the disturbance is lower), and when the natural vibration frequency of the vibration control device is 5% higher than the floor natural vibration frequency, the position of the valley where the vibration reduction effect is maximum shifts to the right (the side where the dominant frequency of the disturbance is higher). This type of change is also seen in the characteristics shown in the graph in Figure 3, and by changing the natural vibration frequency of the vibration control device, the curve <2> It is possible to change the position of the valley of the vibration, thereby obtaining a very large vibration reduction effect. The vibration damping device 100 according to this embodiment focuses on such characteristics and is configured without a damping device (damper), and has a function of detecting the vibration frequency of the vibration of the object to be damped and changing the natural vibration frequency of the vibration damping device 100 accordingly, as described with reference to Fig. 1.

[0025] As shown in Fig. 1, the vibration damping device 100 according to this embodiment has a cantilever type vibration system and can change the position of the movable mass 106, so that the natural vibration frequency can be easily changed. The movable mass 106 can be slid on the upper frame 104, so that the position can be changed continuously, and accordingly, the natural vibration frequency can be changed continuously. It is also possible to change the natural vibration frequency by changing the spring constant and the position of the elastic member 110. Therefore, it is also possible to adopt a configuration in which the natural vibration frequency is changed by changing both the position of the movable mass 106 and the position of the elastic member 110.

[0026] Since the vibration damping device 100 according to this embodiment does not use a damper, when its natural vibration frequency coincides with the dominant frequency of a disturbance acting on the vibration damping target, it can suppress vibration to a very small value (see the curve in FIG. 3). <2> (See A1 of ). By utilizing this state, the mass of the movable mass can be made much smaller than that of a conventional tuned mass damper (TMD). In general, the mass of a conventional tuned mass damper (TMD) is set to 1 to 3% of the mass of the object to be damped, but the mass of the movable mass 106 of the vibration damping device 100 according to this embodiment can be set to less than 0.1 to 3% of the mass of the object to be damped, and preferably to about 0.1 to 0.3%.

[0027] When no disturbance is acting, the vibration of the object to be damped tends to increase at the primary natural vibration frequency. Therefore, the natural vibration frequency of the vibration damping device 100 is initially set to the primary natural vibration frequency of the object to be damped.

[0028] On the other hand, the dominant frequencies of disturbances acting on the vibration control target are different for walking, facility equipment, etc. If the natural vibration frequency of the vibration control device 100 remains fixed, the dominant frequency of the disturbance and the natural vibration frequency of the vibration control device 100 will differ, and the vibration of the vibration control target may become large (see the curve in FIG. 3). <2> (In this state, the vibration damping device 100 is put into a state of A2 in FIG. 1). To solve this problem, the position of the movable mass 106 is adjusted by the driving mechanism 112 so that the natural vibration frequency of the vibration damping device 100 matches the predominant frequency of the disturbance, and the natural vibration frequency of the vibration damping device 100 is controlled to match the predominant frequency of the disturbance. Then, when the disturbance subsides, the position of the movable mass 106 is again adjusted by the driving mechanism 112 so that the natural vibration frequency of the vibration damping target matches the natural vibration frequency of the object to be damped, thereby changing the natural vibration frequency of the vibration damping device 100.

[0029] The vibration damping device 100 according to this embodiment does not constantly vibrate the mass in accordance with the vibration of the target to be damped as in the active control method, but only changes the position of the movable mass 106 to change the characteristics of the vibration system. Therefore, the force required by the drive mechanism 112 only needs to be greater than the frictional resistance, and the speed of change can be slow and the number of changes is not frequent, so a large-scale and complex drive mechanism 112 is not required. Therefore, the vibration damping device 100 requires only a small mass of the movable mass 106 and a small capacity of the drive mechanism 112, so that despite its small overall mass, it can exhibit vibration reduction performance equivalent to that of a tuned mass damper (TMD) with a large mass.

[0030] Figures 5(A) and (B) show an example of the structure of a vibration damping device 100 according to one embodiment of the present invention. Figure 5(A) shows a plan view of the vibration damping device 100, and Figure 5(B) shows a side view of the vibration damping device 100. Note that for the sake of explanation, the X-axis direction, the Y-axis direction, and the Z-axis direction are shown in Figures 5(A) and (B).

[0031] The lower frame 102 is composed of a plurality of frames. Specifically, the lower frame 102 is composed of two frames extending in the X-axis direction and two frames extending in the Y-axis direction. As shown in FIG. 5(A), the lower frame 102 is composed of these frames so as to have a rectangular frame shape in a plan view. Note that the number of frames constituting the lower frame 102 is not limited, and more frames than the number shown in the figure may be used. Although not shown, the lower frame 102 may be formed of a plate-shaped member, or may be composed of a combination of a plate-shaped member and a frame. In any case, it is preferable that the lower frame 102 has a shape and structure that allows it to be installed horizontally so as not to wobble in the installed position.

[0032] Supports 1081a and 1081b forming a rotatable fulcrum 108 are provided on one end side of the lower base 102. The supports 1081a and 1081b protrude upward from the lower base 102 and have a height capable of supporting the upper base 104 in a state separated from the lower base 102.

[0033] The upper frame 104 has a shape capable of supporting the movable mass 106. The upper frame 104 is composed of, for example, a first frame 1041 and a second frame 1042 extending in the X-axis direction, and a third frame 1043 and a fourth frame 1044 extending in the Y-axis direction. The first frame 1041 and the second frame 1042 are arranged so as to overlap with the frame of the lower frame 102 extending in the X-axis direction. The third frame 1043 and the fourth frame 1044 are bridged between the first frame 1041 and the second frame 1042 arranged in parallel at a distance from each other. With this configuration, the upper frame 104 has a rectangular shape in a plan view, and has a structure that does not deform or twist.

[0034] The first end S1 of the upper base 104 is provided with flanges 1045a and 1045b extending downward. The flanges 1045a and 1045b are arranged at positions overlapping the supports 1081a and 1081b, respectively, when the upper base 104 is arranged on the lower base 102, and form a rotatable fulcrum 108. At the rotatable fulcrum 108, a shaft 1082 is inserted through the supports 1081a and 1081b and the flanges 1045a and 1045b. The upper base 104 is rotatably supported by the shaft 1082, so that the positions in the X-axis direction, the Y-axis direction, and the Z-axis direction are fixed on the lower base 102. In addition, the upper base 104 is supported by the shaft 1082 extending in the Y-axis direction, so that the second end S2 is rotatable in the Z-axis direction (up and down direction).

[0035] Elastic members 110a and 110b are attached to the second end S2 of the upper base 104. The elastic members 110a and 110b are installed from above the lower base 102 toward the top, and are provided so as to support the upper base 104 from below. The elastic members 110a and 110b are, for example, springs, and may be coil springs, leaf springs, disc springs, or the like. The elastic members 110a and 110b may also be formed of a rubber material. In this way, the first end S1 side of the upper base 104 is supported by the rotatable fulcrum 108, and the second end S2 is supported by the elastic members 110a and 110b, so that the first frame 1041 and the second frame 1042 are provided horizontally.

[0036] 5(A) and (B) show a state in which the elastic members 110a, 110b are connected between the lower frame 102 and the upper frame 104 and their positions are fixed, but the elastic members 110a, 110b may be attached with a configuration in which their positions can be displaced in the X-axis direction. For example, the lower frame 102 and the upper frame 104 may be provided with guide rails, and the connection positions of the elastic members 110a, 110b may be displaced in the X-axis direction by a drive mechanism (not shown).

[0037] A first guide rail 114a is provided on the upper surface of the first frame 1041, and a second guide rail 114b is provided on the upper surface of the second frame 1042. The movable mass 106 is provided so as to be movable on the first guide rail 114a and the second guide rail 114b. The movable mass 106 is moved on the first guide rail 114a and the second guide rail 114b by the driving mechanism 112, and the position of the movable mass 106 in the X-axis direction on the upper frame 104 is displaced.

[0038] 5(A) and (B) show an example in which the driving mechanism 112 is an electric actuator composed of a ball screw and a motor that drives the ball screw. Although not shown in FIGS. 5(A) and (B), a bearing that supports the ball screw may be provided. The driving mechanism 112 is not limited to a ball screw type, and may be a combination of a rack and pinion and a motor, or may be composed of a hydraulic or pneumatic cylinder. The driving mechanism 112 may also be composed of a linear actuator driven by a linear motor.

[0039] The vibration sensor 116 is attached to an arbitrary position on the lower frame 102. The vibration sensor 116 may be provided at multiple positions on the lower frame 102. Furthermore, one of the vibration sensors 116 may be provided on the movable mass 106. The vibration sensor 116 is a sensor that detects vibrations in the up-down direction (Z-axis direction). When the vibration damping device 100 is installed on a target to be damped, the vibration sensor 116 detects vibrations of the target to be damped.

[0040] The control unit 118 receives a detection signal from the vibration sensor 116, performs arithmetic processing based on the detection signal, and outputs a signal to the drive mechanism 112 to adjust the position of the movable mass 106. The control unit 118 is composed of hardware resources such as a CPU and memory, and software resources for executing the arithmetic processing. The control unit 118 may be realized by a dedicated microcomputer or a general-purpose personal computer.

[0041] As described above, vibration damping device 100 according to one embodiment of the present invention is composed of lower frame 102, upper frame 104 having first end S1 supported on lower frame 102 by free pivoting fulcrum 108, movable mass 106, and elastic members 110a and 110b. The position of movable mass 106 in the X-axis direction (horizontal direction) can be adjusted by drive mechanism 112 that changes the position of movable mass 106, vibration sensor 116 that measures vibration of an object to be damped, and control unit 118 that calculates the optimal position of movable mass 106 and controls drive mechanism 112.

[0042] A conventional TMD (Tuned Mass Damper) is composed of a mass, a spring, and a damper (damping device), but the vibration damping device 100 according to this embodiment does not have a damper (damping device). As described with reference to Fig. 3, if the natural vibration frequency of the vibration damping device 100 matches the natural vibration frequency of the object to be damped or the dominant frequency of the excitation force of the acting disturbance, the vibration of the object to be damped can be suppressed to a very low level. Since the natural vibration frequency of the vibration damping device 100 can be continuously changed by the displacement of the movable mass 106, the vibration reduction effect can be achieved even if the excitation force of the disturbance acts on the object to be damped.

[0043] Next, an example of a procedure from the stage of shipping such a vibration damping device 100 to the stage of installing and operating the vibration damping target will be described. Note that the procedure shown below is an example, and should not be interpreted as being limited solely by the contents of the description.

[0044] After the vibration damping device 100 is manufactured, an inspection is performed before shipping from the factory in order to grasp the characteristics of each device. Fig. 6 shows an example of the flow of a pre-shipment inspection process.

[0045] First, the inspection vibration sensor 120 is installed on the upper frame 104 (or the movable mass 106) to make it possible to measure the vibration of the upper frame 104 (S200 to S202, see FIG. 7). The inspection vibration sensor 120 may be substituted by simply removing the vibration sensor 116 provided on the lower frame 102 of the vibration damping device 100 and installing it on the upper frame 104.

[0046] The driving mechanism 112 drives the movable mass 106 to the position X mim The farthest position from X max The movable mass 106 is moved at minute intervals Δx to the target position, and vibration is applied to the upper platform 104 each time (S204). The vibration may be applied by a vibrator or may be applied intentionally by an operator. j Then, X j is expressed by equation (1) (see FIG. 7). X j =X j-1 +Δx(j=1~N) (1) Where: N=L / Δx L=X max -X min X 0 =X min , X N =X max Δx is a value that can be set appropriately, and for example, a value such as 1 mm can be set.

[0047] The vibration data measured by the vibration sensor 120 is subjected to a spectrum analysis (S206). The spectrum analysis is performed by a separately prepared device, but may be performed by the control unit 118 of the vibration damping device 100. For example, when a vibration waveform as shown in FIG. 8(A) is measured, the spectrum analysis is performed to obtain the vibration waveform of each position (X j ) is obtained, the frequency at which the amplitude is maximum at that position X j The natural vibration frequency f of the vibration damping device 100 j The data is acquired as follows. This process is repeated for each position j=1 to N (S208).

[0048] The position X of the movable mass 106 obtained in step S206 j and the natural vibration frequency at that position, f j From the N data, the position X of the movable mass 106 j and natural vibration frequency f j The function is set as shown in equation (2) (S210). f j = G(x) X j (2)

[0049] The parameter G(x) of the function shown in equation (2) is stored in the control unit 118 (S214). j The natural vibration frequency f of the vibration damping device 100 j is set.

[0050] Next, a procedure for installing the vibration damping device 100 on a target to be damped will be described with reference to FIGS.

[0051] First, the vibration control device 100 is installed on the object to be controlled (S220 to S222). For example, if the object to be controlled is a floor of a building, the vibration control device 100 is installed in a location where floor vibrations are large (i.e., near the center). The vibration control device 100 may be installed on or under the floor. Then, the object to be controlled is subjected to vibration control for a certain period of time (T 0 seconds:T 0 The vibration is measured by the vibration sensor 116. For example, if the object to be damped is a floor of a building, the floor is vibrated. The vibration of the floor may be caused by a vibrator or by a person walking or stamping. By performing such an operation, for example, a vibration waveform as shown in FIG. 10(A) can be obtained.

[0052] Next, a spectrum analysis is performed on the obtained vibration data to find the frequency at which the amplitude is maximum (S226, see FIG. 10(B)). This spectrum analysis is executed by the function of the control unit 118. The frequency at which the amplitude is maximum is then determined as the natural vibration frequency f 0 Let us assume that.

[0053] From the parameter G(x) of the function of equation (2) obtained in step S210, the natural vibration frequency of the vibration damping device 100 is f 0 The position X of the movable mass 106 is 0 Here, the control unit 118 calculates the position X from the formula (3) (S228). 0 Request. X 0 =(1 / G(x))×f 0 (3)

[0054] Then, the driving mechanism 112 moves the position of the movable mass 106 to X 0 The driving mechanism 112 is controlled by a signal from the control unit 118 (S230).

[0055] The natural vibration frequency f of the vibration control target obtained in the above steps0 and the position X of the movable mass 106 0 are stored in the control unit 118 as reference values ​​(reference value of the natural vibration frequency of the vibration damping device 100 and reference value of the position of the movable mass 106) (S232), and the adjustment work is completed (S234). It is preferable to update these reference values ​​periodically by performing a vibration analysis of the object to be damped. The updating frequency may be, for example, once a month or once a year. It is also preferable to update the reference values ​​whenever there is a change in the characteristics or use of the object to be damped.

[0056] Next, with reference to Fig. 11, an operation of the vibration damping device 100 when it is in operation will be described. When control is started (S240), the vibration sensor 116 measures vibration data of the vibration damping target (S242), and the control unit 118 performs a spectrum analysis of the vibration data (S244). The spectrum analysis is performed in the control unit 118, for example, on vibration data measured by the vibration sensor 116 every T1 seconds for the past T2 seconds (see Fig. 12(A)). The lengths of T1 and T2 are arbitrary, and can be, for example, T1 = 0.5 to 1.0 seconds, and T2 = 1.0 to 2.0 seconds.

[0057] From the vibration spectrum, the frequency f 1 , f 2 The frequency f where the amplitude is maximum in the range i and its frequency f i Amplitude d at i (S246, see FIG. 12(B)). 1 , f 2 is defined by the following equations (4) and (5). f 1 =A1×f 0 (4) f 2 =A2×f 0 (5) Here, f 0 is the natural vibration frequency reference value of the vibration damping device 100 calculated in step S226, and A1 and A2 are constants that can be set appropriately. For example, A1=0.5 and A2=1.5.

[0058] It is possible to automatically find the maximum amplitude value using data from the entire frequency range, but in that case, if there are multiple points with similar amplitudes, the wrong selection may be made. 0 By narrowing down the range of data close to and searching for the maximum value, you can prevent erroneous selection.

[0059] Next, f calculated in step S246 i From equation (2), the position X of the movable mass 106 is i (Step S248). Then, the amplitude d i is the preset value d 0 It is determined whether the amplitude d i is the preset value d 0 If it is larger, the driving mechanism 112 moves the movable mass 106 to the position X i (S252), and then it is determined whether or not to continue the control (S254). i is the set value d 0 If it is less than this, the position of the movable mass 106 is left as it is, and a determination is made as to whether or not to continue the control (S254). In determining whether or not to continue the control (S254), if the control is to be continued, the process returns to step S242, and if the control is to be stopped, the operation of the control device 100 is stopped.

[0060] According to the adjustment and control method of the vibration damping device 100 shown in Figures 6, 9 and 11, the relationship between the natural vibration frequency of the vibration damping device 100 and the position of the movable mass 106 is obtained, so the device characteristics can be understood, and even if the vibration damping device 100 is installed in any location, the natural vibration frequency at that location can be easily checked because the vibration damping device 100 is equipped with a vibrometer and a control unit, and the vibration damping device 100 can be set to a state that maximizes (optimizes) the vibration reduction effect. Even if vibrations are generated by external disturbances, a high vibration reduction effect can be achieved by precisely changing the natural vibration frequency of the vibration damping device 100 in response to the disturbance. [Explanation of symbols]

[0061] 100: vibration damping device, 102: lower frame, 104: upper frame, 1041: first frame, 1042: second frame, 1043: third frame, 1044: fourth frame, 1045a, 1045b: flange, 106: movable mass, 108: free pivot point, 1081a, 1081b: support, 1082: shaft, 110, 110a, 110b: elastic member, 112: drive mechanism, 114a, 114b: first and second guide rails, 116: vibration sensor, 118: control unit, 120: vibration sensor, S1: first end, S2: second end

Claims

1. A lower stand; an upper platform having one end rotatably supported on the lower platform and extending in a horizontal direction; an elastic member supporting the other end of the upper frame on the lower frame; A movable mass supported by the upper frame and slidable in a horizontal direction; A drive mechanism that displaces the position of the movable mass; A vibration sensor provided on the lower frame for detecting vibrations; a control unit that calculates a position of the movable mass suitable for vibration damping based on a dominant frequency obtained from a detection signal of the vibration sensor and controls the drive mechanism; A vibration damping device comprising:

2. 2. The vibration damping device according to claim 1, wherein the upper platform has a cantilever structure supported in a cantilever state at a freely rotating fulcrum.

3. The vibration damping device according to claim 1 , wherein the control unit controls the drive mechanism to displace the position of the movable mass so that the dominant frequency coincides with a natural vibration frequency of the vibration damping device.

4. 2. The vibration damping device according to claim 1, wherein the mass of the movable mass is less than 0.1 to 3% of the mass of an object to be damped.

5. The vibration damping device according to claim 1 , wherein the drive mechanism is an actuator or a linear motor.

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