JP2009257486A - Response control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an effective and proper passive-response-control system utilizing an electromagnetic-induction action. <P>SOLUTION: An additional vibration system added to a main vibration system is composed by a DC power generating mechanism (a DC motor 2), which is vibrated by vibration of the main vibration system and generates electromotive force by an electromagnetic-induction action, and an electric circuit 3 that controls resistance force F by controlling a current I flowing in the DC power generating mechanism. The electric circuit is configured from a coil, a capacitor, and a resistor. An inductance L of the coil, capacitance C of the capacitor, and a resistance value R of the resistor are determined by using coefficients K<SB>1</SB>, K<SB>2</SB>being characteristic values of the DC power generating mechanism. Consequently, it is possible to allow the additional vibration system to function as a damper mechanism provided with a spring element of equivalent spring rigidity k, an inertial-mass element of inertial mass ψ, and a damping element of a damping coefficient c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a response control system for vibration systems such as buildings and equipment racks, and in particular, the effect of improving the resonance characteristics in the natural frequency band and the cutoff effect in the specific frequency band by a damper mechanism using electromagnetic induction. The present invention relates to an obtained response control system.

As a damper mechanism using an electromagnetic induction action, a power generation braking type damper as shown in Patent Document 1 and a power generation type vibration suppression apparatus as shown in Non-Patent Document 1 are known.
Japanese Utility Model Publication No. 62-13282 Sagoda, Otake, Matsuoka, "Research on Power Generation Vibration Suppressor", Transactions of the Japan Society of Mechanical Engineers, August 2005

The dynamic braking damper shown in Patent Document 1 is one that exhibits (or does not exhibit) a damper effect in a specific frequency band by a so-called LCR circuit, but Patent Document 1 conceptually describes the principle thereof. However, there is no disclosure about a specific configuration of the LCR circuit and a specific setting method of the frequency band.
The power generation type vibration suppression device disclosed in Non-Patent Document 1 does not generate a variable damping force by changing the load resistance between both terminals of a generator, particularly for the purpose of suppressing minute vibrations of equipment in outer space. However, even if this is added, the natural frequency of the vibration system does not change, so even if it is applied to a structure such as a building as it is, a sufficient effect cannot be obtained. Nor is it widely applicable.
As described above, the effective and appropriate damper mechanism using the electromagnetic induction action and the effective and appropriate response control system using the electromagnetic induction action have only been proposed in principle at present, and have been put into practical use. There is no actual situation.

  In view of the above circumstances, an object of the present invention is to realize an effective and appropriate response control system capable of effectively controlling responses of various vibration systems using electromagnetic induction.

According to the first aspect of the present invention, an additional vibration system is installed for the main vibration system composed of at least two structures that vibrate relatively, and the resistance force F generated in the additional vibration system due to the vibration of the main vibration system is used as a braking force. Is a passive type response control system for controlling the vibration, wherein the additional vibration system is vibrated by the vibration of the main vibration system so that the excitation speed x · (· is attached to the upper part of x) by electromagnetic induction action. A DC power generation mechanism that generates a proportional electromotive force E, and an electric current that is attached to the DC power generation mechanism and controls a resistance value F that is generated in proportion to the current value I by controlling the current value I flowing through the DC power generation mechanism. And the electric circuit is composed of a coil, a capacitor, and a resistor, and an inductance L of the coil, a capacitance C of the capacitor, and a resistor of the resistor. A value R, the coefficient K ₂ wherein the ratio of the resistance force F for the coefficients K _1, and the current value I is the ratio of the electromotive force E with respect to vibration speed x · as characteristic value of the direct current power generating mechanism By using and determining the relationship according to the following equations, the additional vibration system can function as a damper mechanism having a spring element with an equivalent spring stiffness k, an inertial mass element with an inertial mass ψ, and a damping element with a damping coefficient c. It is characterized by.

  The invention according to claim 2 is the response control system according to claim 1, wherein the additional vibration system is made to function as a tuned mass damper for improving the resonance characteristics in the natural frequency band of the main vibration system. A response control system characterized in that a coil and a capacitor in the electric circuit are connected in series and the natural frequency of the additional vibration system is tuned to the natural frequency of the main vibration system.

  A third aspect of the present invention is the response control system according to the second aspect of the present invention, wherein the additional vibration system is used as a tuned mass damper for improving resonance characteristics in each natural frequency band of the main vibration system. In order to make it function, a coil and a capacitor in the electric circuit are connected in series, and a plurality of the series connection circuits are connected in parallel corresponding to each natural frequency band, and each natural vibration of the additional vibration system is connected. The number is tuned to each natural frequency of the main vibration system.

  A fourth aspect of the present invention is the response control system according to the first aspect of the present invention, wherein the additional vibration system is a coil in the electric circuit so as to function as a vibration isolation mechanism for a specific frequency band of the main vibration system. And a capacitor are connected in parallel, and the resonance frequency of the additional vibration system and the main vibration system is tuned to the cutoff frequency.

  A fifth aspect of the present invention is the response control system according to the fourth aspect of the present invention, wherein the additional vibration system is used in the electric circuit to function as a vibration cutoff mechanism for each frequency band of the main vibration system. A coil and a capacitor are connected in parallel, and a plurality of parallel connection circuits corresponding to each frequency band are connected in series, and each resonance frequency of the additional vibration system and the main vibration system is set to each order. It is characterized by being tuned to the cut-off frequency.

  A sixth aspect of the present invention is the response control system according to any one of the first to fifth aspects of the present invention, wherein the rotating shaft is driven by the vibration of the main vibration system as the DC power generation mechanism in the additional vibration system. It is characterized by using a DC motor that is rotated to generate an electromotive force.

  The invention according to claim 7 is the response control system according to claim 6, wherein a ball screw mechanism is used as a transmission mechanism for transmitting the vibration of the main vibration system to a DC motor as a DC power generation mechanism. The ball screw mechanism converts the vibration of the main vibration system into a rotational motion to rotate the rotating shaft of the DC motor, and the resistance force (torque) generated in the DC motor is transferred to the main vibration system via the ball screw mechanism. It is characterized by transmitting to.

  The invention according to claim 8 is the response control system according to claim 7, wherein a speed increasing mechanism is installed between the ball screw mechanism as the transmission mechanism and the DC motor as the DC power generation mechanism, and the increase The vibration of the main vibration system is accelerated by a speed mechanism and transmitted to the DC motor, and the resistance force of the DC motor is expanded by the speed increase mechanism and transmitted to the main vibration system.

The response control system of the present invention is provided with an additional vibration system mainly composed of a DC power generation mechanism that is excited by vibration of the main vibration system and generates electromotive force by electromagnetic induction, and current flowing through the DC power generation mechanism is generated by an LCR circuit. By controlling the vibration using the resistance force as a braking force by controlling with an electric circuit, the additional vibration system can function as a damper mechanism having an equivalent spring element, inertial mass element, and damping element.
In other words, only by appropriately setting the capacity of the resistors, coils, and capacitors in the electric circuit that electrically controls the DC power generation mechanism according to the characteristics of the DC power generation mechanism, the damping coefficient that is the specification of the mechanical vibration, The same effects as the installation of spring rigidity and inertial mass can be obtained, and the specifications can be set appropriately.
Therefore, according to the present invention, the additional vibration system can function as a tuned mass damper (TMD: dynamic vibration absorber) to improve the resonance characteristics of the main vibration system, or the additional vibration system can function as a vibration isolating mechanism. The vibration isolation characteristics in the band can be improved, and it is possible to improve the higher-order (multiple) mode resonance characteristics and obtain higher-order (multiple) mode vibration isolation characteristics with a single damper mechanism by the configuration of the LCR circuit. It is.

In the present invention, since the electric circuit in the additional vibration system is composed of simple electronic parts, it does not require complicated and high-precision mechanical parts unlike various conventional mechanical dampers. Since the circuit has no moving parts, there is no fear of mechanical deterioration or damage, and the entire mechanism can be made sufficiently simple and simple.
Of course, even if the DC power generation mechanism is controlled by an electric circuit, it is passive control, and does not require any control or operation other than setting various specifications of the electric circuit. No power is required.
Moreover, these electronic components can be easily obtained at low cost and with high quality and reliability, and can be freely used with variable characteristics such as variable resistors and variable capacitors (variable capacitors). Therefore, it is possible to freely and widely control the characteristics and performance as a damper mechanism.

"Basic principles of the present invention"
First, the basic principle of the present invention will be described with reference to FIG.
In FIG. 1A, reference numerals A and B are structures that vibrate relative to each other, and reference numeral 1 denotes a damper as an additional vibration system that is added to the main vibration system composed of the structures A and B. Mechanism.

  The damper mechanism 1 in the illustrated example includes a DC motor 2 as a DC power generation mechanism fixed to the structure A, an electric circuit 3 attached to the DC motor 2, and vibration of the main vibration system with respect to the DC motor 2. It consists of a ball screw mechanism 4 as a transmission mechanism for transmitting (relative vibration generated between the structures A and B) and rotating the rotary shaft.

The direct current motor 2 as a direct current power generation mechanism functions as a power generator by electromagnetic induction by rotating a rotating shaft in the same manner as the power generators shown in Patent Document 1 and Non-Patent Document 1, and is built in that case. An electromotive force (voltage) is generated between both terminals of the coil, and a current corresponding to the electromotive force flows.
In this case, the electromotive force generated in the DC motor 2 is proportional to the rotational speed of the rotating shaft, and therefore, the electromotive force is transmitted to the DC motor 2 via the ball screw mechanism 4. It will be proportional to ・.
Note that the excitation speed should be represented by a symbol with a mark at the top of x as shown in FIG. 1 (a), but in the text, it is represented as x. For convenience. . The same applies to the description in claim 1 and other symbols.

The ball screw mechanism 4 is a known mechanism including a ball screw shaft 5 and a ball nut 6. One end of the ball screw shaft 5 is rotatably supported by a bearing 7, passes through the structure A and is connected to the rotating shaft of the DC motor 2, and the other end penetrates the structure B. It is arranged in the hole in a loosely inserted state. The ball nut 6 is fixed to the structure B in a state of being screwed to the ball screw shaft 5.
Therefore, in the ball screw mechanism 4, when relative vibration in a direction in which the structures A and B are separated from each other is generated, the ball nut 6 is displaced in the axial direction with respect to the ball screw shaft 5, whereby the ball screw The shaft 5 is forcibly rotated, and the rotating shaft of the DC motor 2 connected thereto is rotated. In other words, the ball screw mechanism 4 converts the vibration of the main vibration system into a rotational motion and transmits it to the DC motor 2, thereby forcibly rotating the rotating shaft of the DC motor 2 to function as a generator to generate an electromotive force. It will cause.
In addition, by installing an appropriate speed increasing mechanism such as a speed increasing gear using a planetary gear between the ball screw shaft 5 and the DC motor 2, the vibration of the main vibration system is increased and the DC motor 2 is increased. It may be communicated.

  The electric circuit 3 is a so-called LCR series circuit in which a coil, a capacitor, and a resistor are connected in series, and the direct current motor 2 is controlled by controlling a current I flowing between both terminals when an electromotive force is generated in the direct current motor 2. Is the resistance force F that causes the braking force, that is, the braking force for the main vibration system.

FIG. 1B is an explanatory diagram of the basic function (action) of the additional vibration system as the damper mechanism 1 having the above-described configuration.
That is, when an axial displacement occurs in the damper mechanism 1 (additional vibration system) due to the vibration of the main vibration system, the rotating shaft of the DC motor 2 is rotated via the ball screw mechanism 4, and the DC motor 2 is moved by electromagnetic induction. An electromotive force (voltage) is generated by functioning as a generator.
A current value I generated by the electromotive force is controlled by an electric circuit 3 (motor load circuit) including an LCR circuit, and a torque corresponding to the current value I is mainly transmitted via a ball screw mechanism 4 as a damper reaction force (resistance force F). This is transmitted to the vibration system, and the resistance force F acts as a braking force to obtain a braking effect against the damper displacement (vibration of the main vibration system).

  Based on the above basic principle, in the present invention, the specifications of each element of the electric circuit 3 in the additional vibration system, that is, the inductance L of the coil, the capacitance C of the capacitor, and the resistance value R of the resistor are used as a DC power generation mechanism. By appropriately setting according to the characteristics of the direct current motor 2, an additional vibration system constituted by a direct current power generation mechanism (direct current motor 2), a transmission mechanism (ball screw mechanism 4), and an electric circuit 3 (LCR series circuit) Is operated as a damper mechanism equivalent to a mechanical vibration model as shown in FIG. 1C, that is, a damper mechanism including a spring element, an inertial mass element, and a damping element. The response of the main vibration system can be effectively controlled by adding the additional vibration system as such a damper mechanism to the main vibration system.

Hereinafter, the method for setting the specifications of the electric circuit 3 will be described in detail.
Since the electromotive force E generated in the DC motor 2 is proportional to the excitation speed x ·, the electromotive force E is expressed by the following equation using the coefficient K ₁ .
Here, the coefficient K ₁ is a proportionality constant (unit: V · s / m) representing the ratio of the electromotive force E to the excitation speed x ·, which is a characteristic of the mechanism by the DC motor 2 and the ball screw mechanism 4. It is a constant that is uniquely determined as a value (including the characteristics of a speed increasing mechanism when it is provided).

In an electric circuit in which a coil, a capacitor, and a resistor are connected in series, the electromotive force E (voltage) and the current value I are in the relationship of the following expression.

Assuming that the vibration of the main vibration system, that is, the vibration to the additional vibration system is performed by sinusoidal vibration, the displacement x and the current value I due to vibration are set as x = x ₀ e ^iωt and I = I ₀ e ^iωt. The following equation holds.

On the other hand, the resistance force F DC motor 2 occurs is expressed by the following equation using the coefficient K ₂ relating to resistance force caused by the magnetic force generated from the current. Here factor K ₂ is a proportional constant (unit: N / A) representing the ratio of the resistance force F for the current value I is, this is proportional to the torque constant of the DC motor 2, the coefficient of the K ₁ and Similarly, it is a constant that is uniquely determined as a characteristic value of the mechanism by the DC motor 2 and the ball screw mechanism 4 (and the speed increasing mechanism).

The above equation are those that the last term, the damper generates reaction force proportional to the displacement x, the damper is proportional to the velocity x · = iωx, was a damper which is proportional to the acceleration x ‥ = -ω ² x arranged in series Is equivalent to.
That is, as shown in FIG. 1C, this additional vibration system has a viscous damping having a spring element having a spring stiffness k inversely proportional to the coil inductance L and a damping coefficient c inversely proportional to the resistance value R of the resistor. It functions as a damper mechanism including a damper and an inertial mass damper having an inertial mass ψ proportional to the capacitance C of the capacitor.
In other words, the above-described coefficients K ₁ and K ₂ that determine the inductance L of the coil, the capacitance C of the capacitor, and the resistance value R of the resistor as the characteristic values of the DC motor 2 and the ball screw mechanism 4 (and the speed increasing mechanism) are By using and determining by the relationship of the following equations, the additional vibration system can be made to function as a damper mechanism having a spring element with spring stiffness k, an inertia mass element with inertia mass ψ, and a damping element with damping coefficient c. Become.

As described above, in the present invention, the specifications L, C, and R of the coil, capacitor, and resistor constituting the electric circuit 3 are the specifications k, ψ, This corresponds to c.
This means that a capacitor without inertia mass produces a mass effect, a resistor without viscous damping produces a damping effect, and a coil without spring stiffness produces rigidity.
Then, by freely combining these elements, an excellent response control effect for the main vibration system can be obtained by simply connecting the electric circuit 3 having no actual state as a mechanical device to the DC motor 2 (DC power generation mechanism). The mechanism can be configured.

For example, when the coil is omitted from the electric circuit 3, L → 0 and k → ∞, which is equivalent to not providing a spring. Further, when the resistance is omitted, R → 0 is changed to c → ∞, which is equivalent to not providing a viscous damping damper. Further, when the capacitor is omitted, C → 0 is changed to ψ → 0, which is equivalent to not providing an inertia mass damper. Conversely, when only a coil, only a resistor, and only a capacitor are provided independently, each of those electrical elements must be provided independently corresponding to mechanical elements such as a spring, a damping, and an inertial mass damper, respectively. Is equivalent. Of course, when all of them are omitted, it is equivalent to connecting with a rigid body that does not cause displacement (additional vibration system = no damper mechanism is installed).
In this way, it becomes equivalent to a mechanical vibration model in which the coils, capacitors, and resistors in the electric circuit diagram are replaced with corresponding springs, inertial masses, and viscous damping so as to have the same arrangement.

  As described above, the response control system of the present invention can constitute a damper mechanism in which an inertial mass, damping, and a spring are arranged in series by a DC power generation mechanism and an LCR electric circuit. A specific embodiment when applied as a response control mechanism for a body will be described.

“First Embodiment: Application as TMD (1)”
As shown in FIG. 2A, the above damper mechanism is installed as an additional vibration system for the main vibration system supported in a state where the structure is relatively vibrated via the spring rigidity ks with respect to the support structure. To do.
Then, the natural frequency f ₀ and the damping constant h ₀ of the additional vibration system are determined by the relationship of the following equation, and the natural frequency f ₀ of the additional vibration system is tuned to the natural frequency f ₁ of the structure. The vibration system functions as a TMD (tuned mass damper: dynamic vibration absorber), and can greatly improve the resonance characteristics of the structure in the natural frequency band.

As a specific design example, the DC motor has a voltage of 24V, an output of 40W, an internal resistance of 1.7Ω, and a ball screw (planetary reducer) via a speed increasing mechanism (planetary speed reducer) with a speed increasing gear ratio of 5 times. An example of connecting a ball screw mechanism of 5mm lead) is shown.
In this case, the coefficient K ₁ as a characteristic of the DC motor is K ₁ = 0.074 × (2π / 0.005) × 5 = 465 V · s / m, and the coefficient K ₂ is K ₂ = (0.074 / 0.94) × (2π / 0.005) X5 = 495 N / A.
The mass m of the structure is 10 tons, the spring stiffness of the structure is ks = 99 kN / cm, and the damping constant h is 0.01.
The natural frequency f ₁ of the structure is 5 Hz. Therefore, the natural frequency f ₀ = f ₁ = 5 Hz of the damper mechanism of the additional vibration system and ω ₀ = 2πf ₀ = 31.4 rad / s.
If the capacitance C of the capacitor is 4.35 mF, the equivalent inertial mass ψ = CK ₁ K ₂ = 1001 N · s ² / m.
If the electrical resistance of the circuit including the internal resistance of the DC motor is R = 3.0Ω, the equivalent damping coefficient c = (1 / R) K ₁ K ₂ = 76700 N · s / m = 767 N / kine, equivalent to the inertial mass The attenuation coefficient h _{0 is} 1.22.
If the inductance L of the coil is 230 mH, the equivalent spring stiffness k = (1 / L) K ₁ K ₂ = 10 kN / cm.

  FIG. 2B shows the response magnification (ratio of response amplitude to excitation amplitude) when the above-described damper mechanism is installed. By installing the damper mechanism as described above (shown as the damper of the present invention in the figure), the response characteristic at the time of resonance is greatly improved as in the case of installing the normal TMD mechanism (the maximum response value is 91). %), And it can be seen that a large response control effect is exhibited.

In addition, each specification in the above design example can be configured only by a commercially available general DC motor, a ball screw mechanism, a speed increasing mechanism, and an electronic component, and thus, a compact and lightweight having an excellent function as a TMD. The damper mechanism can be easily and inexpensively realized.
In particular, high-quality and highly reliable electronic components can be obtained at low cost and easily. For example, by adopting variable characteristics such as variable resistors and variable capacitors (variable capacitors), the damper mechanism It is possible to freely and widely control the characteristics and performance. That is, the tuning operation of the natural frequency in the case of functioning as a TMD as in the present embodiment can be easily performed by making the capacitor capacity variable, and the adjustment for giving the optimum attenuation is also a variable resistor. Can be easily performed. Of course, those adjustments can be performed not only at the time of installing the damper but also at an appropriate time after the installation and at the time of maintenance, and readjustment and change can be freely performed as necessary.

“Second Embodiment: Application as TMD (2)”
By connecting a plurality of coils and capacitors connected in series in the first embodiment in parallel as shown in FIG. 3A, not only the first order but also the higher order natural frequencies are obtained by one damper mechanism. The TMD can also suppress the resonance characteristics at the same time.
Specifically, the natural frequency f _i of each order of the additional vibration system (i is the order. I = 1, 2,...) And the damping coefficient h _0i of each order are tuned to the frequency for which the resonance characteristics are desired to be improved. Therefore, it is determined by the following equation. The reason _why the setting of f _i is not equal is that it is advantageous to tune f _i to a slightly higher frequency side by the damping effect.

As a specific example in that case, an example in which a damper mechanism is installed in the lowermost layer as shown in FIG.
The horizontal natural frequency of the structure is first order: 2.2 Hz, second order: 6.3 Hz, third order: 9.0 Hz, and the structural damping for the first order is h = 0.02.
Since the influence of the tertiary mode is small, the control is performed only for the primary mode and the secondary mode, and the coefficient α = K ₁ K ₂ = 2.3 kNΩ / kine for the DC motor is set.
ψ ₁ = 10 tons, so C ₁ = ψ ₁ / α = 44 mF. k ₁ ′ = 25 kN / cm, and therefore L ₁ = α / k ₁ ′ = 92 mH. R = 0.5Ω. ψ ₂ = 10 tons, so C ₂ = ψ ₂ / α = 44 mF. k ₂ ′ = 390 kN / cm, and therefore L ₂ = α / k ₂ ′ = 5.9 mH.
As for the resistance R, only one LC series circuit may be installed in series with respect to the parallel LC series circuit as shown in (a). Alternatively, as shown in (b), each resistor is connected to each LC series circuit. A resistor R may be installed in parallel with each capacitor.

The response magnification in the above case is shown in FIG. From this figure, it can be seen that the resonance characteristics are improved not only in the primary mode but also in the secondary mode.
Although it is possible to provide the same function by using conventional TMD, in that case, it is necessary to parallel a plurality of TMDs composed of a mass and a spring corresponding to each target frequency. On the other hand, in the present embodiment, a TMD mechanism corresponding to a plurality of vibration frequencies can be realized by a single damper only by setting an electric circuit, and therefore, an effect equivalent to or higher than that obtained by a conventional TMD can be obtained at a lower cost. There is an advantage that the number of installations and space can be reduced.

As described above, the present invention can function as a TMD. For that purpose, it is premised on that a coil and a capacitor in an electric circuit are connected in series.
In addition, in the present invention, it is also possible to connect a coil and a capacitor in parallel, and in that case, it can be applied not as a TMD but as a vibration isolation mechanism for obtaining a vibration isolation effect in a specific frequency band. This is possible and will be described below with reference to FIG.
Even when the coil and the capacitor are connected in parallel as shown in FIG. 4A, the additional vibration system has a spring element having a spring stiffness k that is inversely proportional to the inductance L of the coil, as shown in FIG. In this case, it functions as a damper mechanism having a viscous damping damper having a damping coefficient c inversely proportional to the resistance value R of the resistor and an inertial mass damper having an inertial mass ψ proportional to the capacitance C of the capacitor. The resistance force F by the direct current motor is as follows. In the formula, α = K ₁ K ₂ .

This resistance force F is equivalent to a resistance force F = 0 and no damper at a frequency determined by the relationship of ω ² = k / ψ, regardless of the excitation speed x ·. If the structure is supported, vibration can be cut off in the frequency band.
Hereinafter, a specific embodiment when applied as such a vibration isolation mechanism will be described.

“Third Embodiment: Application as Vibration Isolation Mechanism (1)”
As shown in FIG. 5, a damper mechanism by an LC parallel circuit in which a coil and a capacitor are connected in parallel is installed as an additional vibration system in parallel with the structure rigidity k _1, and the cutoff frequency f _{0 of the} main vibration system and the additional vibration system is set. The damping constant h ₀ of the additional vibration system is determined by the following equation.

As a specific design example, when the natural frequency f ₁ of the main vibration system is 5 Hz, the coefficient α = K ₁ K ₂ = 2.3 kNΩ / kine by the DC motor and the cutoff frequency f ₀ = 2f ₁ = 10 Hz.
If the capacitance C of the capacitor is 21.8 mF, the equivalent inertial mass ψ = 5 tons. Assuming that the coil inductance L is 23 mH, the equivalent spring stiffness k is 100 kN / cm. If the resistance value R = 0.35Ω, the equivalent attenuation coefficient c = 6.6 KN / kine.
The equivalent damping coefficient h ₀ = 2.0 and the structural damping is h = 0.01.

FIG. 5B shows the response magnification (ratio of the response speed x · to the excitation speed y ·) in the above case. From this figure, it can be seen that a response control effect in the cutoff frequency band can be obtained.
This response magnification is the ratio of the structure amplitude to the excitation amplitude when the vibration is applied from the fixed end. From the Maxwel reciprocity theorem, the excitation force when the structure is vibrated as shown in (c). The ratio F / P of the fixed-end reaction force with respect to is also the same.

“Fourth Embodiment: Application as Vibration Isolation Mechanism (2)”
By further connecting the LC parallel circuit in the third embodiment in series, a damper having a plurality of cutoff frequencies is obtained.
That is, as shown in FIG. 6 (a), a plurality of LC parallel circuits are connected in series corresponding to the respective cutoff frequencies, and the respective cutoff frequencies pf _{i of the} additional vibration system and the main vibration system, Each order attenuation constant h _0i of the additional attenuation system is determined by the relationship of the following equation.

FIG. 6B shows the response magnification when the specifications of each LC parallel circuit are set as in the illustrated example.
In the case of natural frequency f ₁ = 5 Hz of the main vibration system, the case of ignoring the structure stiffness k ₁ in the main vibration system (k ₁ = 0), the setting of _{L 1, C 1 pf 1 =} 7.1Hz (ξ ₁ = pf ₁ / f ₁ = 1.42) is set as the primary cutoff frequency, and pf ₂ = 12.71 Hz (ξ ₂ = pf ₂ / f ₁ = 2.54) is set as the secondary cutoff frequency according to the L ₂ and C ₂ settings. By setting as a number, it can be seen that a vibration cutoff effect can be obtained at both the primary cutoff frequency and the secondary cutoff frequency as indicated by the broken line in the figure.
Conventionally, in order to provide vibration isolation characteristics at two frequencies in this manner, two layers of cutoff layers must be provided in series. However, according to the present invention, only one electrical circuit is set and a single damper is used. For example, it can be installed in a seismic isolation layer to block both the natural primary frequency of the building and the natural frequency of the equipment. Of course, it is possible to provide three or more LC parallel circuits to cope with three or more vibration modes.

Although made of the setting of cut-off frequency is complicated when considering the structure rigidity k _1, cut-off frequency is shifted somewhat compared to the case of ignoring the structure rigidity k ₁ as shown by the solid line in FIG. In addition, the above-described primary cutoff frequency and secondary cutoff frequency have the same response as that without a damper, and a cutoff characteristic can be obtained at a slightly higher frequency.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various designs as listed below, for example, are included within the scope of the present invention. Changes and applications are possible.

  Each of the above embodiments is a control system for the purpose of improving the resonance characteristics and isolating vibration of a structure such as a building. Needless to say, the present invention can be widely applied as a control system for various purposes for various vibration systems, and can be applied to vibrations in the horizontal direction as well as the vertical direction.

In the above embodiment, a DC motor is used as the DC power generation mechanism. However, the present invention is not limited to this, and any DC power generator may be used as long as it can generate electric power by electromagnetic induction and use the resistance force as a braking force for vibration control.
When a DC motor is used as the DC power generation mechanism, it is preferable to use a type having a large number of commutators and a small voltage fluctuation when the speed is constant (when acceleration is zero). When voltage fluctuation occurs at a constant speed, current flows through the capacitor and resistance is generated by the magnetic force of the coil. Therefore, it is assumed that the characteristics as an inertial mass damper may deviate from the equivalent model described above, which is not preferable. .

In the above embodiment, the ball screw mechanism is used as a transmission mechanism for transmitting the vibration of the main vibration system to the damper mechanism and transmitting the resistance force (braking force) of the damper mechanism to the main structure. The transmission mechanism is not necessarily limited to the ball screw mechanism, and other types of transmission mechanisms may be employed as long as they function similarly. Furthermore, depending on various conditions such as the specifications of the vibration system to be controlled, the control purpose, the required control amount, the configuration of the DC power generation mechanism, etc., the transmission mechanism is omitted and the vibration of the main vibration system is transferred to the DC power generation mechanism. However, it is not impossible to transmit the resistance directly to the main vibration system from the DC power generation mechanism.
Further, it is preferable to provide a speed increasing mechanism between the DC power generation mechanism and the transmission mechanism as in the above embodiment, whereby the power generation efficiency of the DC power generation mechanism can be improved, and a large resistance force can be applied to the main vibration system. However, the speed increasing mechanism is not essential and may be omitted if unnecessary.
In any case, when the transmission mechanism and the speed increasing mechanism are provided, the coefficient K ₁ considering not only the characteristics of the DC power generation mechanism but also the characteristics of the transmission mechanism and the speed increasing mechanism when determining the specifications of the electric circuit. , K ₂ may be used.

  In the above embodiment, description of the internal resistance and internal inductance of the DC power generation mechanism is omitted. However, since the attenuation of the additional vibration system changes depending on the value of the internal resistance, the evaluation is performed by adding to the resistance R of the LCR circuit. It is desirable to do. The internal inductance is negligible because it hardly affects the spring stiffness of the additional vibration system when the vibration is 20 Hz or less, which is the target of the vibration of the structure.

It is a figure for demonstrating the basic principle (when an electric circuit is a LC series circuit) of this invention. It is a figure which shows 1st Embodiment. It is a figure which shows 2nd Embodiment same as the above. It is a figure for demonstrating the basic principle (when an electric circuit is LC parallel circuit) of this invention. It is a figure which shows 3rd Embodiment same as the above. It is a figure which shows 4th Embodiment.

Explanation of symbols

A, B structure (main vibration system)
1 Damper mechanism (additional vibration system)
2 DC motor (DC power generation mechanism)
3 Electric circuit 4 Ball screw mechanism (transmission mechanism)
5 Ball screw shaft 6 Ball nut 7 Bearing

Claims (8)

Passive response control in which an additional vibration system is installed for the main vibration system composed of at least two structures that vibrate relatively, and the response is controlled using the resistance force F generated in the additional vibration system due to the vibration of the main vibration system as a braking force. A system,
A DC power generation mechanism that generates an electromotive force E proportional to an excitation speed x · (• is attached to the upper portion of x) by electromagnetic induction by exciting the additional vibration system by vibration of a main vibration system; An electric circuit that is attached to the DC power generation mechanism and controls the resistance value F generated in proportion to the current value I by controlling the current value I flowing through the DC power generation mechanism;
The electric circuit is composed of a coil, a capacitor, and a resistor, and an inductance L of the coil, a capacitance C of the capacitor, and a resistance value R of the resistor are added as characteristic values of the DC power generation mechanism. By adding the coefficient K ₁ that is the ratio of the electromotive force E to the vibration velocity x · and the coefficient K ₂ that is the ratio of the resistance force F to the current value I, respectively, A response control system that causes a vibration system to function as a damper mechanism having a spring element having an equivalent spring stiffness k, an inertial mass element having an inertial mass ψ, and a damping element having a damping coefficient c.

The response control system according to claim 1,
In order to make the additional vibration system function as a tuned mass damper for improving the resonance characteristics in the natural frequency band of the main vibration system, a coil and a capacitor in the electric circuit are connected in series, and the natural vibration of the additional vibration system A response control system that tunes the number to the natural frequency of the main vibration system. The response control system according to claim 2,
In order to make the additional vibration system function as a tuned mass damper for improving the resonance characteristics in the respective natural frequency bands of the main vibration system, the coil and the capacitor in the electric circuit are connected in series, and the series connection circuit thereof In response to the natural frequency band of each order, and the natural frequency of each order of the additional vibration system is tuned to the natural frequency of each order of the main vibration system. system. The response control system according to claim 1,
In order to make the additional vibration system function as a vibration cutoff mechanism for a specific frequency band of the main vibration system, a coil and a capacitor in the electric circuit are connected in parallel, and the additional vibration system and the resonance frequency of the main vibration system A response control system characterized by tuned to the cutoff frequency. The response control system according to claim 4,
In order to make the additional vibration system function as a vibration isolation mechanism for each frequency band of the main vibration system, the coil and the capacitor in the electric circuit are connected in parallel, and the parallel connection circuit is set to each frequency band. A response control system, wherein a plurality of series connections are made in correspondence with each other, and each resonance frequency of the additional vibration system and the main vibration system is tuned to each cutoff frequency. The response control system according to any one of claims 1 to 5,
A response control system using a DC motor that generates an electromotive force by rotating a rotating shaft by vibration of a main vibration system as the DC power generation mechanism in the additional vibration system. The response control system according to claim 6,
A ball screw mechanism is used as a transmission mechanism for transmitting the vibration of the main vibration system to the DC motor as the DC power generation mechanism, and the ball screw mechanism converts the vibration of the main vibration system into a rotational motion to A response control system characterized by rotating a rotating shaft and transmitting a resistance force generated in the DC motor to a main vibration system via the ball screw mechanism. The response control system according to claim 7, comprising:
A speed increasing mechanism is installed between the ball screw mechanism as the transmission mechanism and the direct current motor as the direct current power generation mechanism, and the speed increasing mechanism accelerates the vibration of the main vibration system and transmits it to the direct current motor. A response control system, wherein a resistance force of a DC motor is expanded by the speed increasing mechanism and transmitted to a main vibration system.

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