JPH08270720A - Vibration controller for structure - Google Patents

Abstract

PURPOSE: To surely lower the number of vibration even for a low mode of vibration of a structure. CONSTITUTION: A vibration controller is provided with an accelerometer 42, which detects the acceleration of a structure, a displacement detectors 45, which detects the horizontal movement (or displacement) of a weight 17, an anemometer 41, which is placed on the structure to detect the wind velocity in the direction of horizontal movement of the weight 17, and a controlling device 30, which draws fuzzy inference, based on an acceleration detection signal from the accelerometer 42, a displacement detection signal from the displacement detector 45, and a wind velocity detection signal from the anelometer 41, in order to output the quantity of driving of the weight 17 to a driving motor 21 for the weight 17. Accordingly, since the quantity of driving of the weight 17 is obtained by taking the wind velocity, or the mode of the number of vibration of the structure, in addition to the velocity and displacement of the structure into the fuzzy inference, a large quantity of driving of the weight 17 can be obtained even for the case of low number of vibration, so that the vibration of the structure can be restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for damping horizontal vibrations of structures such as bridge main towers, buildings and towers due to wind pressure and earthquakes.

[0002]

2. Description of the Related Art For example, as shown in FIG. 7, when a cable-stayed bridge is to be erected, a bridge main tower 1 is erected at a predetermined interval, and then a bridge girder 2 is horizontally moved from the bridge main tower 1. The bridge girder 2 and the bridge main tower 1, and a cable 3 is stretched between the bridge girder 2 and the bridge main tower 1 to keep the bridge girder 2 in a horizontal state. The bridge girders 2, 2 are integrally connected to each other between the bridge girders. However, during the construction work, the bridge girders 2 are easily vibrated by the working machine and wind pressure moving on the bridge girder 2, and the vibration state is left as it is. When,
Resonance phenomenon may occur and is very dangerous.
The vibration damping device 4 is arranged on the main bridge tower 1, and the vibration damping device 4 is also arranged on the structures such as the high-rise building 5 and the tower as shown in FIG. 8 for the same reason.

Conventionally, as the vibration damping device 4, there is a pendulum type as shown in FIG. In this, a pendulum 8 is pivotally supported by an upper girder 6a of a machine frame 6 via a pivot shaft 7, and a pendulum rod 8a of the pendulum 8 and longitudinal girders 6b, 6b of the machine frame 6 are respectively provided with predetermined longitudinal intervals. A spring 9 and a damper 10 are disposed between the engaging holes 14 formed in advance so as to be capable of changing the position in the vertical direction, and have a clutch for rotationally driving a gear 12 meshing with a tooth portion 11 formed on the lower end edge of the pendulum body 8b. Drive motor 1
3 is provided on the lower girder 6c of the machine casing 6.

In the above structure, the natural frequency of the structure such as the bridge main tower 1 and the high-rise building 5 in which the vibration damping device 4 is installed is
It is calculated by calculation at the design stage or by actual measurement with a vibration measuring device 15 such as an accelerometer or strain gauge at the site,
Based on the determined set value or measured value, the spring 9
Also, the position of the damper 10 is appropriately changed in the vertical direction so that the natural frequency of the pendulum 8 matches the natural frequency of the structure.

In this state, when the vibration damping device 4 is used as an active type, the damper 10 is deactivated, and the vibration speed and acceleration of the structure and the vibration displacement of the pendulum 8 are measured and detected. The value is multiplied by a constant gain to obtain the drive amount of the pendulum 8, and the drive motor 13 is driven. As a result, when the structure vibrates, the pendulum 8 vibrates at the same frequency as that of the structure, the vibration of the pendulum 8 is maintained by the expansion and contraction of the spring 9, and the driving force of the drive motor 13 causes the structure to move. The vibration of the structure is offset in phase and the vibration of the structure is damped.

When the vibration damping device 4 is used as a passive type due to a failure of the drive motor 13 or the like, the clutch of the drive motor 13 is disengaged and the damper 10 is activated. As a result, the pendulum 8 is vibrated at the same frequency as the structure by vibrating the structure, and the pendulum 8
Vibration is continued by the expansion and contraction action of the spring 9, and the damping action of the damper 10 shifts the phase of the vibration of the structure, and the vibration of the structure is damped.

[0007]

In the conventional pendulum type vibration damping device 4 described above, when used as an active type, the drive amount of the pendulum 8 depends on the vibration speed of the structure, the acceleration, and the vibration displacement of the pendulum 8. Since it is obtained by multiplying by a constant gain, the value of the gain is determined in a high frequency mode of the structure, that is, a high speed mode. Therefore, in the low frequency mode, the pendulum 8 should be moved sufficiently large. However, there is a problem that the vibration damping performance is deteriorated.

The present invention solves the above problems,
It is an object of the present invention to provide a vibration damping device capable of reliably damping the frequency even in a mode in which the structure has a low frequency.

[0009]

In order to solve the above-mentioned problems, a structure vibration damping device of the present invention is a vibration damping device for horizontally moving a weight to suppress vibration of a structure. Driving means for horizontally moving the weight, speed detecting means for detecting the speed of the structure, displacement detecting means for detecting horizontal movement displacement of the weight, and horizontal displacement of the weight installed on the structure. Fuzzy inference is performed based on the wind speed detection means for detecting the wind speed in the moving direction, the speed detection signal of the speed detection means, the displacement detection signal of the displacement detection means, and the wind speed detection signal of the wind speed detection means, and the drive means. It is characterized in that it is provided with a control means for outputting the driving amount of the weight.

[0010]

With the above construction, in addition to the speed and displacement of the structure, the wind speed correlated with the frequency of the structure is taken into the fuzzy inference to obtain the drive amount of the weight. Therefore, even when the frequency is low, a large amount of drive is obtained, and the vibration of the structure is suppressed.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. 1 and 2 show a vibration damping device 4 according to an embodiment of the present invention, which is a machine frame 16 attached to a structure such as a bridge main tower 1 shown in FIG. 7 or a high-rise building 5 shown in FIG. A weight 17 horizontally movably disposed on the machine frame 16, a swing lever 18 pivotally supported on the machine frame 16, and a damper disposed between the swing lever 18 and the machine frame 16. 19 and a spring device 20, and a drive motor (drive device) 21 with an electromagnetic clutch 21a for horizontally moving the weight 17 is provided.

The weight 17 is horizontally movably mounted on a pair of guide rails 22 disposed on the lower girder 16a of the machine frame 16 via linear bearings, and is driven by a rack 23 fixed to the lower surface thereof. The pinion 24, which is normally and reversely rotated by the motor 21, is meshed, and the vibration damping device 4 can be used as an active type by inserting the clutch 21a to drive the drive motor 21. The vibration damping device 4 can be used as a passive type by making it possible to freely move horizontally.

The swing lever 18 is an upper girder 16b of the machine frame 16.
An upper end portion is pivotally supported by a pivot shaft 26 erected on a pair of lever main bodies 18a which engage a roller 28 disposed on a side surface of the weight 17 with a long groove 27 formed in a bifurcated lower end portion thereof; It is composed of a connecting frame 18b arranged between both lever bodies 18a, and swings around the pivot shaft 26 in conjunction with the horizontal movement of the weight 17.

As shown in FIG. 3, the damper 19 is composed of a cylinder 19a and a piston 19b slidably arranged in the cylinder 19a, and when the vibration damping device 4 is used as a passive type, The damping action shifts the phase of the vibration of the weight 17 from that of the structure,
When the vibration damping device 4 is used as an active type, the electromagnetic clutch 21 is activated by the connection signal e from the control device 30.
At the same time as turning on a, the solenoid directional control valve 31 is actuated by the actuation signal f from the control device 30, and the cylinder 19a
Front and rear chambers 29a, 29 partitioned by a piston 19b inside
b is communicated through the oil passage 29c to make the damper 19 inoperative.

As shown in FIG. 1, the spring device 20 includes a cylinder 32, a piston 33 slidably disposed in the cylinder 32, the piston 33 and the cylinder 32.
It is composed of a pair of springs 34 arranged between the front and rear end plate portions, and the vibration of the weight 17 is sustained by the expansion and contraction action of the springs 34.

As shown in FIGS. 1 and 2, the swing lever 1
A large number of through holes 35 are provided at predetermined intervals along the vertical direction in the connecting frame 18b of No. 8 and the side plate 16c provided in the longitudinal girder of the machine frame 16 facing the connecting frame 18b. Piston rods 19c, 33 of device 20
a and the cylinder rods 19d and 32a, the brackets 36 and 37 rotatably connected to the through holes 3
By fixing the bolts and nuts 38 and 39 to the position 5, the positions of the damper 19 and the spring device 20 can be changed in the vertical direction, thereby matching the natural frequency of the weight 17 with the natural frequency of the structure. Is able to. In FIG. 1, 40 is a safety stopper fixed to the machine frame 16 so as to face the front and rear surfaces of the weight 17.

Further, as shown in FIG. 3, the structure such as the bridge main tower 1 and the skyscraper 5 is mounted on the structure in the direction perpendicular to the structure axis (weight 1
An anemometer 41 for measuring the wind speed in the horizontal movement direction 7) is provided, and the wind speed signal v _W of the anemometer 41 and the acceleration signal a _S of the accelerometer 42 of the vibration measuring device 15 are input to the control device 30. There is. Further, the infrared light emitting diode 43 is attached downward at the center of the side surface of the weight 17, and the visible light cut filter / collector which is fixed upward at the center of displacement of the weight 17 facing the infrared light emitting diode 43. P with optical lens
A displacement detector 45 for the weight 17 composed of SD44 is provided, and its displacement signal x _d is input to the control device 30. Further, a selection switch 46 for selecting a method of using the vibration damping device 4, that is, a case where the vibration damping device 4 is used as an active type and a case where it is used as a passive type is provided in the vicinity of the control device 30, and the selection signal d is input to the control device 30. Has been done.

FIG. 4 shows the configuration of the control device 30. An amplifier 51, which amplifies the signals v _W , a _S , and x _d , respectively,
52, 53 and the acceleration signal a _S amplified by the amplifier 52.
And an amplified signal v _W , a
_S , x _d and the output signal of the integrator 54, that is, the speed signal v
An A / D converter 55 for converting _S to digital, and a fuzzy controller 5 for forming a control signal c for the motor 21 from the signals v _W , a _S , x _d , v _S converted into digital signals.
6 (details will be described later) and D for converting the motor control signal c output from the fuzzy controller 56 into an analog signal.
/ A converter 57, a driver 58 for driving the motor 21 based on the motor control signal c converted into an analog signal, a connection signal e for the electromagnetic clutch 21a, and an electromagnetic signal based on the selection signal d from the selection switch 46. It is composed of a judging device 59 (details of which will be described later) that outputs an operation signal f of the switching valve 31. The fuzzy controller 56 and the judging device 5
Reference numeral 9 is formed by a microcomputer.

The fuzzy controller 56 receives the speed signal v _S and the acceleration signal a _S as a first fuzzy rule section 61.
And a second fuzzy rule unit 62 which receives the displacement signal x _d and the speed signal v _S , and the wind speed signal v _W and the speed signal v _S
It is composed of a third fuzzy rule section 63 which receives as input and an inference section 64 which obtains an output value (control signal c of the motor 21) from the inferred values of these fuzzy rule sections 61, 62 and 63. Since the wind speed signal v _W is correlated with the vibration frequency of the structure, the driving amount inferred from the vibration frequency and speed of the structure is obtained by the third fuzzy rule unit 63.

The fuzzy control rules of the fuzzy rule units 61, 62 and 63 are shown in Tables 1, 2 and 3, and the membership function is shown in FIG.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

31 kinds of fuzzy rule parts 61, 33 kinds of fuzzy rule parts 62 and 2 kinds of fuzzy rule parts 63
A fuzzy set is obtained by the min-max method according to each of the eight rules, and the center of gravity (motor drive amount) and the fitness of the union of these fuzzy sets are output.

The inference unit 64 includes three rule units 61, 6
Each of the centroids respectively input from Nos. 2 and 63 is multiplied by the goodness of fit and then added, and the respective suitable values are added, and the added value of the multiplied value is divided by the added value of the respective suitable values, that is, The control signal c of the motor 21 is output.

When the active type is selected by the selection signal d, the judging device 59 outputs a connection signal e for connecting the clutch 21a to connect the motor 21 to the weight 17 and to connect the electromagnetic switching valve 31. An actuation signal f for actuation is output, and the two front and rear chambers 29a, 29b partitioned by the piston 19b in the cylinder 19a are communicated with each other via the oil passage 29c, and the damper 19 is deactivated.

Further, when the passive type is selected by the selection signal d, the judging device 59 turns off the connection signal e to the clutch 21A to cut off the drive of the motor 21, and the operation signal f to the electromagnetic switching valve 31. Is turned off to activate the damper 19.

Explaining the damping principle based on the above-mentioned structure, the natural frequency of the structure such as the bridge main tower 1 and the high-rise building 5 in which the damping device 4 is installed is calculated at the design stage or at the site. Indexing is performed by actual measurement using a vibration measuring device 15 such as an accelerometer or strain gauge, and the positions of the damper 19 and the spring device 20 are appropriately changed in the vertical direction based on the indexed set values or measured values to uniquely identify the weight 17. Match the frequency with the natural frequency of the structure.

In this state, when the vibration damping device 4 is used as the active type, the active type is selected by the selection switch 46, and the damper 19 is deactivated by the actuation signal f of the electromagnetic switching valve 31 of the control device 30. At the same time, the clutch 21a is turned on by the connection signal e, and the drive motor 21 is driven according to the control signal c of the motor 21 by fuzzy reasoning. As a result, when the structure vibrates, the weight 17 vibrates at the same frequency as that of the structure, the vibration of the weight 17 is sustained by the expansion and contraction of the spring 34, and the driving force of the drive motor 21 causes the vibration. The phase of the vibration of the structure is shifted and the vibration of the structure is damped.

FIG. 6 shows an example of measurement results of the displacement of the structure and the displacement of the weight 17. As can be seen from the measurement results, the high-frequency mode has the same damping effect as the conventional one, and in the present invention, the drive amount of the weight 17 based on the wind speed, that is, the frequency of the structure is determined. By adding
In the low frequency mode, the weight 17 can be driven more greatly than in the conventional case, and the vibration of the structure can be suppressed as compared with the conventional case.

Further, the natural frequency of the weight 17 can be changed only by changing the positions of the spring 34 and the damper 19 in the vertical direction, and when the active type is used, the expansion and contraction action of the spring 34 is reduced. Since it can be used, the energy consumption of the drive motor 21 can be made extremely small, and since the swing lever 18 and the weight 17 are connected in an edge-cutting state in which the swing and horizontal movement thereof are not restricted, the natural vibration of the weight 17 is achieved. The number can be easily changed over a wide range irrespective of the length of the rocking lever 18, and has the advantage of the pendulum type vibration damping device, and the drawback thereof can be eliminated.

When the vibration damping device 4 is used as a passive type due to a failure of the drive motor 21, the passive type is selected by the selection switch 46 and the connection signal e is turned off to disengage the clutch 21a. By turning off the operation signal f of the electromagnetic switching valve 31, the damper 19 is brought into the operation state shown in FIG. As a result, when the structure vibrates, the weight 17 vibrates at the same frequency as that of the structure, the vibration of the weight 17 is sustained by the expansion and contraction of the spring 34, and the damper 19 damps the structure. The phase of the vibration of the object is shifted and the vibration of the structure is damped.

[0033]

As described above, according to the present invention, in addition to the velocity and displacement of the structure, the wind speed, that is, the mode of the frequency of the structure is taken into the fuzzy inference to obtain the drive amount of the weight. By doing so, even when the frequency is low, a large amount of driving of the weight can be obtained, and vibration of the structure can be suppressed.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a structure vibration damping device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a vibration damping device for the structure.

FIG. 3 is a control configuration diagram of the vibration damping device for the structure.

FIG. 4 is a configuration diagram of a control device of the vibration damping device for the structure.

FIG. 5 is a membership function diagram of the control device of the vibration damping device for the structure.

FIG. 6 is a characteristic diagram showing a measurement result of the vibration damping device for the structure.

FIG. 7 is a schematic diagram showing an example of an installed state of a structure vibration damping device.

FIG. 8 is a schematic view showing another example of the installed state of the structure vibration damping device.

FIG. 9 is a front view of a conventional structure vibration damping device.

[Explanation of symbols]

 16 Machine frame 17 Weight 18 Swing lever 19 Damper 21 Drive motor 21a Clutch 26 Pivot shaft 30 Control device 31 Electromagnetic switching valve 34 Spring 41 Anemometer 42 Accelerometer 45 Displacement detector 46 Selector switch 54 Integrator 56 Fuzzy controller 59 Judgment device

Claims (1)

[Claims] 1. A vibration damping device for horizontally moving a weight to suppress vibration of a structure, comprising: driving means for horizontally moving the weight; speed detecting means for detecting a speed of the structure; Displacement detecting means for detecting horizontal displacement of the weight, and installed on the structure,
Based on the wind speed detecting means for detecting the wind speed in the horizontal movement direction of the weight, the speed detecting signal of the speed detecting means, the displacement detecting signal of the displacement detecting means, and the wind speed detecting signal of the wind speed detecting means, fuzzy inference is performed. A vibration damping device for a structure, comprising: a control unit that outputs a driving amount of a weight to the driving unit.