JP3136325B2 - Hybrid dynamic vibration absorber - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid dynamic vibration absorber that suppresses vibration of a structure due to an earthquake, wind disturbance, or the like.

[Prior Art] Conventionally, the following two types of devices are generally known as dynamic vibration absorbers for suppressing vibration of a structure.

One of them is a movable additional mass at a predetermined position of a structure to be damped, and an actuator installed between the additional mass and the structure and supporting the additional mass movably in a horizontal direction. This is a so-called active dynamic vibration absorber having:

The other is a so-called passive dynamic vibration absorber that reduces the amplitude of a specific vibration mode of a structure by coupling a predetermined spring and a damper to the movable additional mass.

[Problems to be Solved by the Invention] However, the conventional dynamic vibration absorber has the following disadvantages.

That is, in the above-described active dynamic vibration absorber, since the vibration is controlled according to the vibration of the structure, it is necessary to supply all the energy necessary for absorbing the vibration from outside. That is the point. Therefore, when this dynamic vibration absorber is applied to a heavy structure such as a high-rise structure, an enormous amount of energy needs to be supplied, and at the current technical level, it is applied only to a relatively light structure. The reality is that you cannot do that.

In the passive dynamic vibration absorber as described above, since the amplitude of a specific vibration mode of the structure is reduced, it is not necessary to externally supply energy necessary for absorbing vibration, It has an effect only on a specific vibration mode, that is, a frequency range. Therefore, when a vibration mode over a wide frequency band is excited like an earthquake, the effect of reducing the vibration cannot be expected so much.

The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a hybrid dynamic vibration absorber that has a vibration suppression effect over a wide frequency range and can significantly reduce the amount of external energy supplied.

[Means for Solving the Problems] The present invention provides a method for reducing vibration at a predetermined position on a structure to be reduced.
The additional mass is movably provided, a spring and a fixed damper are provided between the additional mass and the structure, and the passive mass damper is configured by the additional mass, the spring, and the fixed damper. A variable damper and an actuator provided in parallel with the additional mass are installed between the additional mass and the structure, and an active dynamic vibration absorber is configured by the variable damper, the actuator, and the additional mass. The variable damper and the actuator generate a control force necessary for damping determined according to the state quantity of the mass, and the vibration of the structure is controlled by the control force. .

According to a second aspect of the present invention, a gain is set to be smaller when a control force is generated by the actuator than when a control force is generated by the variable damper.

[Operation] According to the hybrid dynamic vibration absorber of the present invention, since the active dynamic vibration absorber in which the actuator is installed is provided between the additional mass and the structure, a wide frequency range is provided. It is possible to exhibit a vibration suppressing effect over a range of At the same time, a structure as a passive dynamic vibration absorber having a spring and a fixed damper is provided between the movable mass and the structure, and the vibration generated in the structure is Some of the energy is absorbed by these additional masses and dampers and serves to control horizontal vibrations. Therefore, it is possible to reduce an external supply amount of energy required for driving the actuator.

Further, in the hybrid dynamic vibration absorber of the present invention, a variable damper is provided in parallel with the actuator, and when vibration is excited in a structure by an external force such as an earthquake or wind, the structure and the additional mass are provided. The variable damper and the actuator act on the basis of a predetermined control law based on the state quantity of the vehicle to determine the control force required for reducing the vibration. Then, from the relationship between the relative speed of the structure and the additional mass and the sign of the required control force, it is determined whether or not the variable damper can generate this control force. Generate control force. If not possible,
The control force is supplied by an actuator. Since the energy required to control the variable damper is smaller than the energy required to drive the actuator,
The energy to be supplied to the hybrid dynamic vibration absorber from the outside can be greatly reduced as compared with the case where all of the control force is generated by the actuator.

In particular, by setting the gain when the actuator generates the control force smaller than when the variable damper generates the control force as described in claim 2, the external energy supply amount can be further increased. It becomes possible to reduce.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings by showing examples.

FIG. 1 shows an embodiment of the hybrid dynamic vibration absorber of the present invention, in which the hybrid dynamic vibration absorber A is mounted on the top of a structure B.

The hybrid dynamic vibration absorber A is provided with an additional mass 1 movably provided between two columns 8, 9 projecting vertically upward at the top of the structure B, and between the column 8 and the additional mass 1, A spring 2 and a fixed damper 3 provided to connect them, a variable damper 4 and an actuator 5 provided in parallel between the column 9 and the additional mass 1 to connect them, and an upper end of the column 8 Sensors provided at the upper end of the section and the additional mass 1 to detect the speed and displacement of the structure B and the hybrid dynamic vibration absorber A, respectively.
7 and the main configuration.

The spring 2 and the fixed damper 3 have predetermined constants so as to be a passive dynamic vibration absorber near the natural frequency of the structure B. The variable damper 4 and the actuator 5 constitute an active dynamic vibration absorber. That is, in the hybrid dynamic vibration absorber A, the passive dynamic vibration absorber and the active dynamic vibration absorber that share the additional mass 1 are provided in a parallel relationship with each other.

As a control law of the hybrid dynamic vibration absorber A, the sensors 6 and 7 detect the speed and displacement of the structure B and the hybrid dynamic vibration absorber A, and the control force to be applied to the structure B based on the optimal control theory. Is adopted to determine the feedback. Then, the control force is used as the reaction force of the additional mass 1 and the actuator 5 or the
To the structure B.

Next, as shown in FIG. 2, a model in which a dynamic vibration absorber is installed on the top of a building made up of one mass point will be considered and its operation will be described.

In FIG. 2, reference numeral 10 denotes a first mass point, which is movably connected to a fixed wall by a first spring 11 and a first fixed damper 12, whereby the first mass point is obtained.
This shows a state in which vibrations due to external forces such as earthquakes and winds are excited in a building composed of ten. In addition, a second mass 13 is movably provided between the two columns 20, 21 protruding vertically upward from the top of the first mass 10, and the second mass 13 and the column 20 are provided. In between, a second spring 14 and a second fixed damper 15 are provided, and between the second mass 13 and the support column 21, a variable damper 16 and an actuator 17 parallel thereto are provided, Thus, a model in which a dynamic vibration absorber is installed at the first mass point 10 is shown.

When an external force F due to wind is applied to this model, the equation of motion of this model is represented by the following equation.

In the above equation, m ₁ and m ₂ are the masses of the building (first mass point 10) and the additional mass (second mass point 13, respectively), c ₁ and k ₁
Are the damping and the spring constant of the building (first mass point 10), respectively. Similarly, c ₂ and k ₂ are a damping and a spring constant connecting the building (first mass point 10) and the dynamic vibration absorber (second mass point 13). u is a control force generated by the actuator 17 or the variable damper 16, and is generally given by the following equation in the case of feedback control.

Here, the feedback gains gv ₁ , gv ₂ , gd ₁ , gd ₂ are
For example, it is determined by an optimal control law. Normally, this control force is realized only by the actuator 17, but in the present invention, it is realized by both the control force ud by the variable damper 16 and the control force ua by the actuator 17. Each control force is given by the following equation.

In the above equation, α is a reduction coefficient (0 ≦ α ≦ 1) for the actuator 17, and if this value is reduced, the necessary energy to be supplied from the outside is reduced. However, since the vibration suppression effect is reduced, this is determined from the balance between the capability of the actuator 17 and the required performance for the main vibration absorber. As described above, by mainly using the variable damper 16 to generate the control force, it is possible to greatly reduce the required energy.

Next, results of a simulation analysis performed by the present inventors to verify the effects of the present invention will be described. The constants used for the analysis are as follows.

Structure Hybrid dynamic vibration absorber (period 3 seconds) (period 3.289 seconds) m ₁ = 25.51 ton / cm / sec ² m ₂ = 0.5102 ton / cm / sec ² c ₁ = 1.07 ton / cm / sec c ₂ = 0.1368 ton / cm / sec k ₁ = 111.90 ton / cm k ₂ = 1.862 ton / cm The external wind force was given by the following equation.

F = 3p sin (ωt) + 7p sin (2ωt) + 5p sin (3ωt) + 4p sin (4ωt) (6) where p is a maximum external force of 2.551 ton (that is, Fmax / m
₁ = 100 cm / sec ² ). Ω is the natural frequency of the building. In this model, ω is 2.09 rad /
sec. FIG. 3 shows the time history of the input waveform. The control force u was given by the following equation.

Reduction factor α for control force ua by actuator 17
Was calculated for three types of 0.1, 0.5, and 1.0.

FIG. 4 shows the displacement (cm) of the first mass point 10 and the acceleration (cm / se) of the first mass point 10 when α = 0.1.
c ^2), the control force ua + ud (ton), the control force ua (ton), the control force
The power (watt) required to generate ua is shown in order.

Similarly, FIG. 5 shows a case where α = 0.5, and FIG. 6 shows a case where α = 1.0. In FIG. 6, however, it is assumed that ua = u and the control force is supplied by the actuator 17 in all cases. Incidentally, when there is no control, the maximum response acceleration of the building is close to 1000 cm / sec ² .

As is clear from these figures, it is understood that the power for driving the actuator 17 can be reduced without significantly reducing the vibration suppression effect by reducing the reduction coefficient. Since the energy required for controlling the variable damper 16 is very small as compared with the actuator 17, the dynamic vibration absorber according to the present invention may be a device capable of greatly reducing the required energy. Understand.

As described above, according to the hybrid dynamic vibration absorber A of the present embodiment, the actuator 5 is provided between the movable mass 1 and the structure B, and the spring 2 and the fixed damper are provided. Since the device 3 is provided, it has both a configuration as an active dynamic vibration absorber and a configuration as a passive dynamic vibration absorber. Therefore, it is possible to exhibit the vibration suppressing effect over a wide frequency range, and at the same time, the additional mass 1 and the fixed damper 3 absorb a part of the vibration energy generated in the structure B, and Acting to control the vibration in the direction, it is possible to reduce the amount of energy supply required for driving the actuator 5. Therefore, it is possible to effectively control the vibration of the entire frequency band caused by the external force such as an earthquake or a strong wind, and to apply to a heavy structure such as a high-rise building. It is possible to ensure the safety measures in the event of high winds.

Further, since the variable damper 4 is provided in parallel with the actuator 5, when vibration is excited in the structure A by an external force due to an earthquake, wind, or the like, the state quantity of the structure A or the additional mass 1 is changed. Alternatively, the variable damper 4 and the actuator 5 act on the basis of a predetermined control law from an external force vector or the like to determine a control force required for reducing vibration. Then, based on the relationship between the relative speed between the structure A and the additional mass 1 and the sign of the required control force, it is determined whether or not the variable damper 4 can generate this control force. 4 generates the necessary control force. If it is not possible, the actuator 5 supplies a control force. Since the energy required for controlling the variable damper 4 can be smaller than the energy required for driving the actuator 5, compared to a case where all of the control force is generated by the actuator 5, its vibration suppressing effect is maintained. Externally this hybrid dynamic vibration absorber A
Energy to be supplied to the vehicle can be greatly reduced.

In particular, if the gain in the case where the actuator 5 generates the control force is set to be smaller than that in the case where the variable damper 4 generates the control force, it is clear from the result of the simulation analysis. In this way, it is possible to further reduce the amount of external energy supply. Therefore, the present invention can be applied to a heavy structure such as a high-rise building, and a very economically advantageous vibration control can be performed.

[Effects of the Invention] As described above, according to the hybrid dynamic vibration absorber of the present invention, a passive dynamic vibration absorber is provided by providing a spring and a fixed damper between the additional mass and the structure, while the additional mass Since the passive dynamic vibration absorber described above constitutes an active dynamic vibration absorber sharing an additional mass by providing a variable damper and an actuator in parallel with the structure between the passive dynamic vibration absorber and the passive dynamic vibration absorber It has a function as a so-called hybrid type dynamic vibration absorber that has both the characteristics of a dynamic vibration absorber and the characteristics of an active dynamic vibration absorber. That is, it is possible to exhibit the vibration suppression effect over a wide frequency range,
The amount of energy supply required for driving the actuator can be reduced.

Further, according to the hybrid dynamic vibration absorber of the present invention, since the variable damper is provided in parallel with the actuator, a control force for controlling vibration is generated by the variable damper and the actuator. The energy required to control the variable damper is extremely small compared to the energy required to drive the actuator,
Compared to the case where all control forces are generated by the actuator, the amount of external energy supply can be reduced while maintaining the vibration suppression effect.

In particular, if the gain when the actuator generates the control force is set to be smaller than when the variable damper generates the control force, the amount of external energy supply is further reduced. It is possible to do. Therefore, vibration can be suppressed very economically, and the invention can be applied to a heavy structure such as a high-rise building.

[Brief description of the drawings]

1 to 6 show an embodiment of the hybrid dynamic vibration absorber of the present invention. FIG. 1 is a schematic explanatory view of the hybrid dynamic vibration absorber, FIG. 2 is a diagram of a vibration model, FIG. 3
FIGS. 4A to 4C are graphs showing the time histories of the input waveforms, and FIGS. 4 to 6 are graphs showing the characteristics when the reduction coefficient is changed. ) And FIG. 6 (a) are graphs showing response displacement when the reduction coefficient is changed, and FIGS. 4 (b), 5 (b) and 6 (b) are reduction coefficients. FIG. 4 (c), (d), and FIG. 5 (c) showing the response accelerations when the pressure is changed.
(D), FIGS. 6 (c) and 6 (d) show the control force when the reduction coefficient is changed, FIGS. 4 (e), 5 (e) and 6 (c).
FIG. 7E is a graph showing the actuator power when the reduction coefficient is changed. A: hybrid dynamic vibration absorber, B: structure, 1 ... additional mass, 2 ... spring, 2 ... fixed damper, 4 ... variable damper, 5 ... actuator

Continuation of the front page (56) References JP-A-63-156171 (JP, A) JP-A-63-5331 (JP, A) JP-A-60-57029 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16F 15/02 E04H 9/02 341

Claims (2)

(57) [Claims] 1. A method according to claim 1, further comprising the steps of:
An additional mass is movably provided, a spring and a fixed damper are provided between the additional mass and the structure, and a passive dynamic vibration absorber is configured by the additional mass, the spring, and the fixed damper. A variable damper and an actuator provided in parallel with the additional mass are installed between the additional mass and the structure, and an active dynamic vibration absorber is configured by the variable damper, the actuator, and the additional mass. A hybrid dynamic vibration absorber characterized in that the variable damper and the actuator generate a control force required for damping determined according to the state quantity of the mass, and the vibration of the structure is controlled by the control force. vessel. 2. The hybrid system according to claim 1, wherein a gain when the control force is generated by the actuator is set smaller than a case where the control force is generated by the variable damper. Vibration absorber.