JP4640668B2 - Structure damping method and damping system - Google Patents

Description

  The present invention relates to a structure damping method and damping system.

Conventionally, various methods have been proposed as a vibration control method for suppressing vibration of a structure. For example, in Patent Document 1, the actuator installed in the vicinity of the base of the tower-like structure is controlled to control the vibration of the tower-like structure by generating a force in a direction to restrain the strain generated in the tower-like structure. A vibration damping device is disclosed. Further, in Patent Document 2, a vibration damping method in which a vibration damping device including a piezoelectric sensor and a piezoelectric actuator is attached to the surface of a satellite structure panel, and vibrations that cancel vibrations generated in the satellite structure panel are generated in the piezoelectric actuator. And a damping device is disclosed.
JP 2003-221807 (page 2-3, FIG. 1) JP 2002-321700 A (page 2-4, FIG. 4)

However, in the case of damping the structure, in the conventional damping device and damping method described in Patent Document 1 and Patent Document 2, if there is a deviation between the vibration direction of the structure and the excitation direction of the actuator, There is a problem that the vibration control effect cannot be obtained. In addition, the control system design is often complicated and cannot be said to be highly reliable.
The present invention has been made in view of the above-described problems, and provides a vibration damping method and a vibration damping system for a structure that have a large vibration damping effect, high reliability, and easy control system configuration. With the goal.

In order to achieve the above object, in the vibration damping method for a structure according to the present invention, when the deflection of the structure is increased, the axial direction is vertically lowered from the center of gravity of the structure in a stationary state toward the base end surface of the structure. In addition , the bending force is controlled by inputting an exciting force having a constant amplitude and a constant period to the structure body and bending the structure body in a direction approaching the axis .
Here, the structure is a general term for objects including equipment and structures. The constant amplitude means that the maximum amplitude is constant, and the constant period means that the period is constant.
When an excitation force is input to the structure, the structure vibrates in the input direction of the excitation force or a direction close thereto. In other words, the structure has a characteristic that it vibrates so as to approach the excitation direction, and the flexure approaches the excitation direction. The present invention utilizes this principle (hereinafter referred to as the first principle).
Therefore, in the case where the bending of the tip end portion of the cantilever beam whose base end portion is fixedly supported as shown in FIG. 1 is increasing, the base end portion of the cantilever beam has an X-axis direction (structure in a stationary state). By inputting a constant amplitude and constant period excitation force from the center of gravity of the body in the direction of the axis perpendicular to the base end surface of the structure, the cantilever is Controls to suppress (decrease) the increase in deflection of the tip of the cantilever because it vibrates so as to approach the force input direction or a direction close to it, that is, the X-axis direction (structure axis method). Is possible.

Further, in the structure damping method according to the present invention, when the bending of the structure is reduced, the centrifugal force about the axis perpendicular to the base end surface of the structure from the center of gravity of the structure in a stationary state is applied. The bending is controlled by inputting to the structure and bending the structure away from the axis .
Here, the input of centrifugal force may be a positive / negative inversion input or a rotational input in only one direction. Further, it may be a constant rotation angle (the maximum rotation angle is constant) and a fixed cycle input, or may not be a fixed rotation angle or a fixed cycle input.
When a centrifugal force is input to the structure, the structure tries to move away from the center of rotation of the centrifugal force. The present invention utilizes this principle (hereinafter referred to as the second principle). Therefore, when the bending of the distal end portion of the cantilever beam whose base end portion is fixedly supported as shown in FIG. 2 is decreasing, the centrifugal force around the X axis is input to the proximal end portion of the cantilever beam. Thus, according to the second principle, the tip of the cantilever beam tends to move away from the rotational center of the centrifugal force, that is, the X axis, so that braking is applied to the decrease in bending of the tip of the cantilever beam. It can be controlled.

Further, in the structure damping method according to the present invention, when the deflection of the structure increases, the axis of gravity of the structure in a stationary state from the center of gravity of the structure toward the base end surface of the structure has a constant amplitude and A constant-period excitation force is input to the structure to bend the structure in a direction approaching the axis, and when the bending of the structure is reduced, a centrifugal force around the axis is input to the structure to The bending of the structure is controlled by bending the structure in a direction away from the axis .
The present invention uses the first principle and the second principle, and when the deflection of the structure is increased, a constant amplitude and constant period excitation force is input to the structure to reduce the deflection of the structure. Sometimes a greater damping effect can be obtained by inputting centrifugal force around the axis to the structure.

Further, in the structure damping method according to the present invention, when the bending increases, the product of the bending of the structure tip and the bending speed of the structure tip becomes positive or zero. enter the exciting force of constant amplitude and fixed cycle in the axial direction in the structure, also, because the product of the speed deflection the deflection and the is negative when the deflection is reduced, the axis around which case The centrifugal force may be input to the structure.
The base end portion shown in FIG. 3 will be described using a cantilever beam fixedly supported. In the figure, the deflection in the Y-axis direction (direction perpendicular to the X-axis) at the tip of the cantilever is Py, and the deflection speed in the Y-axis direction is Vy.
When Py is positive, the tip of the cantilever is on the positive side of the Y axis. At this time, if Vy is positive, the tip of the cantilever beam is going away from the X axis (the deflection increases) (see FIG. 3A). Conversely, when Py is negative, the tip of the cantilever is on the negative side of the Y axis. At this time, if Vy is negative, the tip of the cantilever beam is going away from the X axis (the deflection increases). That is, when PyVy ≧ 0, it means that the bending of the tip of the cantilever increases. Therefore, in this case, if an excitation force having a constant amplitude and a constant period is input to the cantilever in the X-axis direction, an increase in bending of the tip of the cantilever is suppressed.
Also, if Py is positive (the tip of the cantilever is on the positive side of the Y-axis), if Vy is negative, the tip of the cantilever is approaching the X-axis (the deflection is reduced). (See FIG. 3B). Conversely, when Py is negative (the tip of the cantilever is on the negative side of the Y-axis), if Vy is positive, the tip of the cantilever is approaching the X-axis (the deflection is reduced). It will be. That is, when PyVy <0, it means that the bending of the tip of the cantilever is reduced. Therefore, in this case, if the centrifugal force around the X-axis is input to the cantilever, the decrease in the bending of the tip of the cantilever is suppressed.

In the structure damping method according to the present invention, it is preferable to perform zero correction of an input value prior to inputting the excitation force and the centrifugal force to the structure.
In the control for switching the excitation force and the centrifugal force according to the bending state of the structure, it is assumed that the initial value of the translation position and the rotation angle of the actuator that generates the excitation force or the centrifugal force is zero. However, normally, when switching between the excitation force and the centrifugal force, the initial value of the actuator is unlikely to be zero. As a result, the deviation of the origin of the actuator is accumulated. Therefore, in the present invention, the input value is zero-corrected prior to the input of the excitation force and the centrifugal force to the structure.

In the structure damping method according to the present invention, it is preferable that the excitation force and / or the centrifugal force is input as a periodic vibration input using a sine wave .
Since the periodic vibration only defines that the period is constant, the waveform having any shape is a periodic vibration if the waveform is repeated at a constant period. However, depending on the shape of the waveform, there are cases where it is not preferable for the control system, such as exciting a spike phenomenon in the structure. Therefore, in the present invention, a sine wave is suitable as the fixed-period vibration input.

Further, in the structure damping system according to the present invention, an axial excitation force that is vertically lowered from the center of gravity of the structure in a stationary state toward the base end surface of the structure is input to the structure. An actuator capable of deflecting the structure in a direction approaching the axis and inputting a centrifugal force around the axis to the structure to bend the structure in a direction away from the axis. And a sensor for detecting the bending of the structure is provided at the distal end of the structure.
In the present invention, an actuator that can input an excitation force and a centrifugal force to the structure is provided at the base end of the structure, and a sensor that detects the bending of the structure is provided at the tip of the structure. Thus, it is possible to realize a vibration suppression system that switches between an excitation force and a centrifugal force according to the bending of the structure.

In the present invention, the exciting force in the axial direction perpendicular to the base end surface of the structure body from the center of gravity of the structure body in a stationary state or the centrifugal force around the axis line is input to the structure body. Therefore, the damping effect does not depend on the vibration direction of the structure, and it is not necessary to consider interference with the vibration of the structure. As a result, it is possible to obtain a high damping performance without greatly changing the damping performance depending on the vibration direction of the structure.
In addition, according to the present invention, a greater vibration damping effect can be obtained by inputting an axial excitation force when the structure is increased in bending and a centrifugal force around the axis when the structure is decreased in bending. Obtainable.
Furthermore, in the present invention, the control input may be an excitation force or a centrifugal force having a constant amplitude and a constant period, so that the configuration of the control system becomes simple. As a result, the reliability of the vibration suppression system is improved.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a structure damping method and a damping system according to the present invention will be described with reference to the drawings.
FIG. 4 is a schematic diagram showing an example of an embodiment of a structure damping system according to the present invention.
As shown in FIG. 4, in the structure damping system 1 according to the present embodiment, a translational actuator 3 and a rotary actuator 4 are provided at the base end of a rod-like structure 2. On the other hand, a sensor 5 is attached to the tip of the rod-like structure 2.
Hereinafter, for the sake of convenience, the axial direction perpendicular to the center of gravity of the structure 2 in the stationary state from the base end surface of the structure 2 is defined as the X-axis direction, and the direction orthogonal to the X-axis is defined as the Y-axis direction.

The translation actuator 3 can input an excitation force in the X-axis direction to the structure 2 by expanding and contracting its tip in the X-axis direction. The rotary actuator 4 can input centrifugal force around the X axis to the structure 2 by rotating around the X axis.
The sensor 5 measures the deflection P _y in the Y-axis direction and the deflection speed V _y in the Y-axis direction at the tip of the structure 2. Usually, by integrating the acceleration of the structure 2 detected by the sensor 5, the bending and the bending speed are obtained.

Next, a method of damping the structure 2 using the structure damping system 1 according to the present embodiment will be described.
FIG. 5 is a diagram showing a control flow of the structure damping method according to the present invention.
In the vibration damping method and the vibration damping system for a structure according to the present invention, the deflection P _{y of the} distal end portion of the structure 2 is equal to or less than the deflection target value e _P and the deflection velocity V _y of the distal end portion of the structure 2 is the deflection velocity target value. Control to make e _V or less is performed (S1).
First, it is checked whether or not the deflection P _{y in} the Y-axis direction of the distal end portion of the structure 2 is equal to or less than the deflection target value e _P and whether or not the deflection speed V _y is equal to or less than the deflection speed target value e _V ( S2). If the deflection P _y is equal to or less than the deflection target value e _P and the deflection speed V _y is equal to or less than the deflection speed target value e _V , the control ends there, but if the deflection P _y exceeds the deflection target value e _P , or, if the deflection velocity V _y is greater than the deflection speed target value e _V proceeds to step S3.
In step S3, it is checked whether or not the product of the deflection P _y and the deflection speed V _y is zero or more. When the product of the deflection P _y and the deflection speed V _y is equal to or greater than zero, the deflection of the structure 2 is increasing, and the translation actuator 3 applies a constant amplitude and constant period excitation force to the structure 2. Input (S4). At the same time, zero correction of the input value of the rotary actuator 4 is performed (S5).
On the other hand, when the product of the bending P _y and the bending speed V _y is negative, the bending of the structure 2 is reduced, and the rotating actuator 3 applies a centrifugal force having a constant rotation angle and a fixed period to the structure 2. (S6). At the same time, zero correction of the input value of the translation actuator 3 is performed (S7).
The sensor 5 measures the deflection P _y and the deflection speed V _y at the tip of the structure 2 (S8). Thereafter, the above control is repeated until the bending P _y and the bending speed V _y become equal to or less than the target values e _P and e _V.

In the structure damping method and damping system according to the present embodiment, an excitation force in the X-axis direction or a centrifugal force around the X-axis is input to the structure 2, so that the damping effect is in the vibration direction of the structure 2. There is no dependence, and there is no need to consider interference with the vibration of the structure 2. As a result, the vibration damping performance does not change greatly depending on the vibration direction of the structure 2, and a high vibration damping performance can be obtained.
Further, in the vibration damping method and vibration damping system of the structure according to the present embodiment, an excitation force having a constant amplitude and a constant period in the X axis direction when the deflection of the structure 2 is increased, and around the X axis when the deflection of the structure 2 is decreased. By inputting the centrifugal force of 2 to the structure 2, a greater vibration damping effect can be obtained.
Furthermore, in the structure damping method and damping system according to the present embodiment, the control input may be an excitation force or a centrifugal force having a constant amplitude and a constant period, so that the configuration of the control system is simplified. As a result, the reliability of the vibration suppression system is improved.

  The embodiments of the structure damping method and the damping system according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the scope of the present invention. is there. For example, in the above-described embodiment, the present invention is applied to a rod-shaped structure, but the scope of the present invention is not limited to a rod-shaped structure, such as a triangular pyramid or a cone-shaped structure. Needless to say, it can also be applied.

It is a conceptual diagram which shows the method of controlling the bending of the said structure at the time of the bending increase of a structure. It is a conceptual diagram which shows the method of controlling the bending of the said structure at the time of the bending reduction of a structure. It is a conceptual diagram which shows the method of controlling the bending of a structure, (a) respond | corresponds at the time of the bending increase of a structure, and (b) respond | corresponds at the time of the bending reduction of a structure, respectively. It is the schematic which shows an example of embodiment of the damping system of the structure which concerns on this invention. It is a figure which shows the flow of control of the vibration damping method of the structure which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Damping system of structure 2 Structure 3 Translation actuator 4 Rotation actuator 5 Sensor

Claims (7)

When the deflection of the structure increases, a constant amplitude and constant period excitation force is input to the structure in the axial direction perpendicular to the base end surface of the structure from the center of gravity of the structure in a stationary state. A structure damping method , wherein the bending is controlled by bending the structure in a direction approaching the axis . When the bending of the structure is reduced, a centrifugal force around the axis perpendicular to the base end surface of the structure is input from the center of gravity of the structure in a stationary state to the structure, and the structure is separated from the axis. A structure damping method , wherein the bending is controlled by bending in a direction . When the deflection of the structure increases, a constant amplitude and constant period excitation force is input to the structure in the axial direction perpendicular to the base end surface of the structure from the center of gravity of the structure in a stationary state. The structure is bent in a direction approaching the axis, and when the bending of the structure decreases, by inputting a centrifugal force around the axis to the structure and bending the structure in a direction away from the axis , A vibration damping method for a structure, wherein the bending of the structure is controlled. When the product of the bending of the structure tip and the bending speed of the structure tip is positive or zero and the bending of the structure increases, an excitation force having a constant amplitude and a constant period is applied in the axial direction. Fill in the structure
4. The structure according to claim 3, wherein a centrifugal force around the axis is input to the structure when the product of the bending and the bending speed is negative and the bending of the structure decreases . Vibration control method. 5. The structure damping method according to claim 4, wherein zero correction of input values is performed prior to input of the excitation force and the centrifugal force to the structure. Said input of excitation force and / or the centrifugal force, vibration damping method of a structure according to any one of claims 1 to 5, characterized in that the periodic vibration input by a sine wave. It is possible to input an excitation force in the axial direction perpendicular to the base end surface of the structure from the center of gravity of the structure in a stationary state to bend the structure in a direction approaching the axis. In addition, an actuator that can input a centrifugal force around the axis to the structure and bend the structure in a direction away from the axis is provided at the base end of the structure.
A vibration damping system for a structure, comprising a sensor for detecting a bending of the structure at a tip portion of the structure.

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