JPH04280308A - Earthquake isolation and vibration proof control method - Google Patents

Abstract

PURPOSE:To obtain an ideal attenuation characteristic by controlling the attenuation force of a variable attenuation damper from the relative speed of a substrate and an earthquake isolation or vibration proof object and the absolute speed of the earthquake proof or vibration proof object through the use of fuzzy inference. CONSTITUTION:An output signal from a sensor 8 measuring the absolute speed of a structure 2 is inputted to a controller for fuzzy controller 6. Simultaneously, the value of the sensor 8, and that of a sensor 9 measuring the absolute velocity of a foundation 1 itself are inputted to the controller 6 and a signal from a computing element 10 showing the relative velocity of the foundation 1 and the structure 2 is inputted to the controller 6. The controller 6 controls the attenuation coefficiency of the variable attenuation damper 4 through a power amplifier 7. The variable attenuation damper 4 gives the structure 2 control force in the horizontal direction between the foundation 1 and the structure 2. Thus, the variable attenuation damper 4 is fuzzy controlled and attenuation force which is proportional to the absolute velocity is given to a vibration system by adding not only the absolute velocity but the relative velocity.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method used for seismic isolation or vibration isolation control of structures, machine tools, etc.

0002

BACKGROUND OF THE INVENTION In recent years, in order to suppress the effects of earthquakes, buildings with so-called seismic isolation structures have been constructed in which buildings are supported by, for example, laminated rubber or various dampers. Conventional dampers used in buildings with this type of seismic isolation structure have a structure that provides the building with a damping force that is mainly proportional to the relative velocity between the ground and the building.

0003

[Problems to be Solved by the Invention] In the conventional seismic isolation or vibration isolation control method using the above-mentioned damping damper, the damper cannot provide a damping force proportional to the absolute velocity between the structure and the ground. There was a drawback that ideal damping characteristics could not be obtained.

That is, to explain this with reference to the general acceleration response magnification characteristic shown in FIG. 8, as can be seen from the figure, when the applied damping force is small, the response in the high frequency range becomes small; The response at the resonance point becomes larger. Conversely, when the applied damping force is increased, the response at the resonance point becomes smaller, but the response in the high frequency range becomes larger. The curve shown by the broken line in the figure is the ideal damping characteristic, which is obtained by applying a damping force proportional to the absolute speed to the vibration system. As described above, if only a damping force corresponding to the relative velocity between the structure and the ground is uniquely applied, it is not possible to obtain the ideal damping characteristics as shown by the broken line.

[0005]Although it is possible to apply active control using an actuator to provide a damping force corresponding to the absolute speed to the vibration system, active control has drawbacks in terms of reliability and economy.

The present invention has been made in view of the above-mentioned circumstances, and aims to provide a seismic isolation/vibration isolation control method that provides nearly ideal damping characteristics by applying a damping force proportional to absolute speed to a vibration system. purpose.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a variable attenuation damper between a base and an object to be seismically isolated or vibration-proofed placed above the base. At the same time as measuring the absolute speed of the seismically isolated or vibration-proofed object, the damping characteristics of the variable damping damper are controlled by fuzzy inference from the relative speed between the two and the absolute speed of the seismically isolated or vibration-proofed object. It is characterized by

[0008]

[Operation] By measuring the absolute speed of the base and the absolute speed of the seismically isolated or vibration-proofed object, taking into account not only the absolute speed of the seismically isolated or vibration-proofed object but also the relative speed between the two. , fuzzy control of variable damping damper,
Gives a damping force proportional to the absolute speed to the vibration system.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an example in which the method of the present invention is applied to a seismic isolation structure. In the figure, numeral 1 is the ground, 2 is a structure supported on the ground 1 via the laminated rubber 3, and 4 is the ground 1 and the structure 2.
This is a variable damper that is interposed between the structure and the structure to apply a horizontal restraining force to the structure. The damping coefficient of the variable damper 4 is controlled via a power amplifier 7 by a controller 6 for so-called fuzzy control, which will be described in detail later. The output signal from the sensor 8 that measures the absolute speed of the structure 2 is input to the controller 6, as well as the value of the sensor 8 and the value of the sensor 9 that measures the absolute speed of the ground 1 itself. An output signal from a calculator 10 that generates relative velocity in the form of an electrical signal is also input.

Various dampers such as an electromagnetic damper and an oil damper can be used as the variable damper 4, and here, as an example, a known electromagnetic damper 4 shown in FIG. 2 is used.
Use. This damper 4 has one mounting portion 14 attached to the casing 13, and the casing 13
The other mounting part 16 is attached to the cylindrical part 15 fixed to the cylindrical part 15, and a ball screw 18 is attached to the cylindrical part 15.
The ball screw 1
The rotor 20 made of aluminum rotates together with the shaft 19 attached to the shaft 19 , and a resistance force is generated between the rotor 20 and the magnet 22 and coil 23 in the casing 13 facing the rotor 20 .
This structure provides a predetermined damping force between 16 and 16. Note that the resistance force generated between the rotor 20 and the coil 23 changes depending on the magnitude of the current flowing through the coil 23.

Next, the function of the controller 6 will be explained while explaining a seismic isolation control method for a structure using the variable attenuation damper. When the structure 2 is shaken due to an earthquake or the like, the absolute velocities of the structure 2 and the ground 1 are measured by sensors 8 and 9, respectively, and the measured values are sent to the controller 6 and the calculator 10, respectively. The computing unit 10 calculates the relative velocity between the structure 2 and the ground 1, and sends these values to the controller 6 in the form of electrical signals.

The controller 6 performs so-called fuzzy control. In other words, an example of the rule is shown in Figure 3(a).
, (b), and shown in FIGS. 4(a) and (b). Figure 3(a), (
c) is the antecedent part of the velocity membership function, and Figure 3 (
b) shows the attenuation coefficient membership function which is the consequent part. The rules for Figure 3 (a) antecedent part - Figure 3 (b) consequent part are shown in Figure 4 (a), and Figure 3 (c) antecedent part - Figure 3
(b) The rule for the consequent part is shown in FIG. 4(b). Here, PB stands for positive big, PM stands for positive middle, PS stands for positive small, ZO stands for zero, NB stands for negative big, NM stands for negative middle, and NS stands for negative small. According to this rule, when the absolute velocity of structure 2 is large and the relative velocity between structure 2 and ground 1 is small, a large damping coefficient is applied, and conversely, when the absolute velocity of structure 2 is small and the relative velocity between structure 2 and ground 1 is small, a large damping coefficient is applied. The controller 6 issues a predetermined output signal to the variable damper 4 so as to provide a small damping coefficient when the relative speed between the two is large. The actual control is shown in Figure 4 above.
This is done by combining the rules (a) and (c).

FIG. 5 shows the acceleration response magnification when the fuzzy control described above is actually performed. The conditions are that a structure weighing 2 tons (natural period 1.3 seconds) is made of laminated rubber (damping 1.5 seconds).
%), and the results of a simulation analysis on this are shown. FIG. 5(a) shows the amplitude, and FIG. 5(b) shows the damping coefficient. As shown in these figures, it can be seen that by introducing the above-described fuzzy control, ideal damping characteristics can be obtained compared to the case without a damper or when a passive damper is used. Figure 6
and Figure 7 show different types of seismic waves (100Ga
A comparative example of changes in acceleration response waveforms and damping coefficients (0 to 100%) when a passive damper is used and when fuzzy control is performed is shown when given (standardized to l). Although there are some differences in effectiveness depending on the input wave, it can be seen that the response is generally reduced to about 80% of that when using a bassive damper. Note that the object to which the present invention is applied is not limited to any structure, and it goes without saying that the present invention can also be applied to, for example, a machine tool.

[0014]

As explained above, according to the method of the present invention, the absolute speed of the base is measured, and the absolute speed of the target for seismic isolation or vibration isolation is measured, and the absolute speed of the target for seismic isolation or vibration isolation is measured. In addition, by taking into account the relative speed between the two, it is possible to perform fuzzy control on the variable damping damper and apply a damping force proportional to the absolute speed to the vibration system, thereby achieving ideal damping without introducing active control. has become possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view showing one embodiment of the method of the present invention.

FIG. 2 is a sectional view showing an example of a variable attenuation damper used when carrying out the method of the present invention.

[Figure 3] Figures 3 (a) and (c) are diagrams showing the velocity membership function of the antecedent part of fuzzy control, and Figure 3 (b) is a diagram showing the damping coefficient membership function of the consequent part of the same control. It is.

FIGS. 4(a) and 4(b) are diagrams each explaining the rules of the fuzzy control.

FIGS. 5A and 5B are diagrams showing simulation results when the above-mentioned fuzzy control is implemented, respectively. FIGS.

FIG. 6 is a diagram showing a comparative example between a case where a passive damper is used and a case where fuzzy control is performed when seismic wave input is applied.

FIG. 7 is a diagram showing a comparative example similar to the above when another type of seismic wave input is applied.

FIG. 8 is a diagram showing a general acceleration response magnification of a vibration system.

[Explanation of symbols]

1 Base (ground) 2 Seismic isolation or vibration isolation object (structure) 3 Laminated rubber 4 Variable damping damper 6 Controller 8 Speed sensor 9 Speed sensor

Claims (1)

[Claims] Claim 1: A variable attenuation damper is provided between a base and a seismically isolated or vibration-proofed object placed above the base, and the absolute speed of the base is measured and the A seismic isolation/vibration isolation control method comprising: measuring an absolute velocity, and controlling the damping force of the variable damper by fuzzy reasoning from the relative velocity between the two and the absolute velocity of an object to be isolated or vibration-isolated.