JPH10318879A - Compensation apparatus for influence of disturbance in vibration testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compensation apparatus which can compensate an influence on the response waveform of a vibration base with reference to a load change and to a disturbance applied to the vibration base by a method wherein disturbance- estimation compensator which generates an input used to compensate and offset the disturbance applied to the vibration base by means of the feedback of a displacement is installed at a feedback circuit. SOLUTION: When a desired value is applied as a voltage from a vibration signal device 11, the voltage is converted into a current so as to be amplified by a servoamplifier 12 which is composed of adders 7, 8 and of an amplifier 6, and the current is supplied to a servo valve 3. The acceleration of a table detected by an acceleration detector 5 and a speed which is converted by integrating an acceleration by using a feedback control device 9 which is composed of an integrator 12, of a accelerometer 14 and of a displacement meter 15 are fed back to the adders as voltage signals. When a disturbance is applied to the table, an acceleration signal is sent to a disturbance observer 10, the disturbance observer 10 compares the acceleration signal with a deviation due to the vibration signal device and due to a feedback signal, and a signal which offsets the disturbance is superposed on the adder 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vibration device for a vibration table.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Patent Laid-Open No. 49-115568.
JP-A No. 1993-2009, the "compensation device for load effects in a vibration tester" detects the differential pressure between the oil chambers at both ends of the cylinder that drives the shaking table, which is one of the vibration test devices, and adds this to the conventional feedback circuit. The influence of the load on the shaking table caused by the load is removed.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a control circuit for controlling a shaking table by controlling the influence of a fluctuation in load on the shaking table on a shaking table response waveform and the influence of a disturbance applied to the shaking table on a shaking table response waveform. It is eliminated by providing a compensator for estimating and compensating the disturbance inside.

[0004]

According to the present invention, a disturbance observer for estimating and compensating for a disturbance is provided in a control circuit for controlling the shaking table.

[0005]

FIG. 1 is a control mechanism diagram of a shaking table provided with a disturbance compensator. In FIG. 1, when a target value is applied as a voltage from an excitation signal unit 11, a servo amplifier 12 including adders 7, 8 and an amplifier 6 converts and amplifies the voltage into a current, and the current is supplied to a servo valve 3. Supplied.
The servo valve 3 supplies the pressurized oil from the hydraulic source to the vibrator 2 by the current, and vibrates the table 1 by displacing the vibrator 2.

On the other hand, the acceleration of the table 1 detected by the acceleration detector 5 and the speed obtained by integrating and converting the acceleration by the feedback control device 9 including the integrator 13, the acceleration clock 14 and the displacement meter 15 are respectively shown. The voltage signal is fed back to the adder 7.

When a disturbance d is applied to the table 1, an acceleration signal is detected by the acceleration detector 5 and sent to a disturbance observer 10 as an acceleration signal. The disturbance observer 10 compares the acceleration signal with a deviation caused by the excitation signal unit 11 and the feedback signal, and cancels the influence of the disturbance on the servo valve 3 by superimposing a signal for canceling the disturbance on the adder 8. A signal is added.

[0008] A disturbance observer is configured for a vibrating table in which the rigidity of the joint in the vibrator is sufficiently large and the displacement Za of the vibrator is assumed to be equal to the table displacement. The equation of motion of the shaking table is given by Equation 1 to Equation 5.

Relational expression between input signal 11 and current of servo amplifier 6

[0010]

[ _Equation 1] i = K _amp · e ( _Equation 1)

[0011]

[Number 2] _{e = r-K adv · z} a ... ( Equation 2) wherein the linearized pressure-flow characteristics of the servo valve 3 by the operating point near

[0012]

Equation 3] _{q = K sq · i-C} sl · p m ... ( Equation 3) continuity equation which ignores the compressibility of the oil

[0013]

(Equation 4)

Equation of motion of shaker 2 (or table 1)

[0015]

(Equation 5)

[0016] Here, e: Deviation Input r: Input signal [V] K _adv: vibrator feedback gain [V / m] z _a: shaker displacement [m] i: output current of the servo amplifier [mA ] _Kamp : Servo amplifier gain [mA / V] q: Servo valve flow rate [m ³ / s] K _sq : Servo valve flow rate gain [m ³ / (mA · s)] C _sl : Servo valve leak flow rate coefficient ^{[m 3 / (Pa · s} )] p sm: differential pressure _{[Pa] a a · (dz} a / dt) = a a · v a: wherein the vibrator flow [m ³
/ _S] A s: shakers piston pressure receiving area _{^{[m 2] (dz a /}} dt) = v a: shakers piston speed [m / s] M: vibrators movable part mass [kg] (d ² z _a / dt ² ): The acceleration of the shaker [m / s ² ].

When the equations (1) to (5) are put together, a block diagram of the control object in FIG. 2 is obtained.

The inside of the broken line in FIG.

[0019]

(Equation 6)

As a first embodiment, a disturbance observer based on displacement feedback is constructed.

Deriving the estimated value d _{0 of the} disturbance from Equation 6

[0022]

(Equation 7)

Is obtained. By inserting a filter into Equation 7, the following equation is obtained.

[0024]

(Equation 8)

Ω ₀ in Equation 8 represents a band of disturbance suppression by the disturbance observer.

FIG. 3 is a block diagram of a disturbance compensator for removing the influence of disturbance by feedback of displacement. FIG.
FIG. 9 shows a simulation result of a response of the shaking table to a step disturbance as a first embodiment. FIG. 5 shows a simulation result of a response of the shaking table to a frequency disturbance as a first embodiment.

As a second embodiment, a disturbance observer based on acceleration feedback is constructed. Transforming equation 7

[0028]

(Equation 9)

Is obtained. When constructing a disturbance observer from Equation 9,

[0030]

(Equation 10)

## EQU1 ## FIG. 6 shows a block diagram of a disturbance compensator for removing the influence of disturbance by feedback of acceleration. FIG. 7 shows a simulation result of a response of the shaking table to a step disturbance as a second embodiment. FIG. 8 shows a simulation result of a response of the shaking table to frequency disturbance as a second embodiment.

As a third embodiment, a disturbance observer based on acceleration and displacement feedback is constructed. Transforming equation 7

[0033]

[Equation 11]

Is obtained. When constructing a disturbance observer from Equation 11,

[0035]

(Equation 12)

## EQU1 ## FIG. 9 is a block diagram of a disturbance compensator for removing the influence of disturbance by feedback of acceleration and displacement. FIG. 10 shows a simulation result of a response of the shaking table to a step disturbance as a third embodiment. FIG. 11 shows a simulation result of a response of the shaking table to frequency disturbance as a third embodiment.

[0037]

According to the present invention, by providing a disturbance compensator for compensating disturbance in a control circuit for controlling a shaking table, the influence of disturbance generated during a vibration test can be eliminated. 4, 5, 7, 8, 10, and 11 also show that the disturbance observer can compensate for the influence of the disturbance.

[Brief description of the drawings]

FIG. 1 is a control mechanism diagram of a vibration table including a disturbance compensator in a vibration device of the present invention.

FIG. 2 is a block diagram of a control target.

FIG. 3 is a block diagram of a disturbance compensator that removes the influence of disturbance by feedback of displacement.

FIG. 4 is a characteristic diagram of a step disturbance simulation according to the first embodiment of the present invention.

FIG. 5 is a characteristic diagram of a frequency disturbance simulation according to the first embodiment of the present invention.

FIG. 6 is a block diagram of a disturbance compensator that removes the influence of disturbance by feedback of acceleration.

FIG. 7 is a characteristic diagram of a step disturbance simulation according to the second embodiment of the present invention.

FIG. 8 is a characteristic diagram of a frequency disturbance simulation according to the second embodiment of the present invention.

FIG. 9 is a block diagram of a disturbance compensator that removes the influence of disturbance by feedback of acceleration and displacement.

FIG. 10 is a characteristic diagram of a step disturbance simulation according to the third embodiment of the present invention.

FIG. 11 is a characteristic diagram of a frequency disturbance simulation according to the third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Table 2 ... Exciter, 3 ... Servo valve, 4 ... Displacement detector, 5 ... Acceleration detector, 6 ... Amplifier, 7, 8 ... Adder, 9 ... Feedback control device, 10 ... Disturbance observer, 11 ... Excitation signal device, 12 servo amplifier, 13 integrator, 14 accelerometer, 15 displacement meter, d disturbance.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masato Kobayashi 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref.

Claims (1)

[Claims] 1. A cylinder for driving a shaking table, a servo valve for controlling pressure oil supplied to the cylinder, an excitation signal generator for transmitting a target value corresponding to a displacement of the shaking table as a voltage signal, A feedback circuit having a shaking table displacement detector and an acceleration detector for converting the feedback element of the table displacement, velocity, and acceleration into a voltage and feeding it back;
An electro-hydraulic comprising an adder for calculating a difference between voltage signals from the signal generator and the feedback circuit and detecting a deviation, and an amplifier for amplifying the deviation signal from the adder and adding the amplified signal to a servo valve. In a vibration testing machine equipped with a servo mechanism, a disturbance estimation compensator that generates an input for compensating and canceling a disturbance applied to a vibration table by displacement feedback is provided in the feedback circuit. For compensating for disturbance in the vehicle.