JP2013029331A - Control system of vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control system of a vibrator that synchronizes vibration forces of vibrating units in a high-frequency region.SOLUTION: The control system 1 of a vibrator 10 is configured to control operation of the vibrator 10 that vibrates a sample W placed on one vibration plate 20, by a hydraulic vibrating unit 30 that vibrates the sample W with a pressure difference PL of fluid and an electrodynamic vibrating unit 40 that vibrates the sample W by supplying a drive current to a drive coil 43 arranged in a magnetic field 40a. The control system includes a power synchronization control part 3 that actuates the electrodynamic vibrating unit 40 on the basis of the pressure difference PL to synchronize a phase T1 of the vibration force F1 of the hydraulic vibrating unit 30 with a phase T2 of a vibration force F2 of the electrodynamic vibrating unit 40.

Description

  The present invention relates to a vibration device control system that controls the operation of a vibration device that vibrates a specimen placed on one diaphragm by a fluid pressure vibration device and an electrodynamic vibration device. About.

Conventionally, when a specimen (for example, an automobile or the like) is vibrated and a state change or the like of the specimen is inspected, a vibratory apparatus is used.
The vibration device is provided by supplying a drive current to a fluid pressure type vibration device that vibrates a specimen by a differential pressure of a fluid (for example, oil or water) or a drive coil disposed in a magnetic field. There are electrodynamic excitation devices that vibrate a specimen.

Although the fluid pressure type vibration device can vibrate the specimen while achieving both high vibration force and high frequency vibration, the fluid is always supplied at the maximum pressure. For this reason, when the specimen is vibrated with an excitation force smaller than the maximum excitation force, the energy consumption increases.
The electrodynamic excitation device can adjust the excitation force by adjusting the excitation current value and the drive current value, so the energy consumption decreases according to the excitation force, but when the excitation force is increased The excitation speed will decrease. For this reason, it is impossible to achieve both high excitation force and high frequency excitation.

  Therefore, by synchronizing the excitation force of the hydraulic and electrodynamic excitation devices at high loads (excitation with high excitation force), the capacity of each excitation device is reduced, and the high excitation force and It is conceivable to use a hybrid excitation device that can achieve both high-frequency excitation and improve energy efficiency in accordance with the excitation force.

The fluid pressure type and the electrodynamic type vibration devices have different characteristics such as responsiveness (time from issuing a command signal to starting movement).
Therefore, when a command signal is issued simultaneously to the fluid pressure type and electrodynamic type vibration devices, a phase shift occurs in the vibration force of each vibration device, resulting in power loss. For this reason, there is a need for a control system that controls the operation of a hybrid type vibration apparatus that combines a fluid pressure type and an electrodynamic type vibration apparatus.

Patent Document 1 discloses a technique for synchronizing the rotation speed, rotation direction, and the like of the shafts of a plurality of motors that are individually driven.
In the technique disclosed in Patent Document 1, a position correction amount based on a common position command transmitted to each motor, the position of each motor, and the like is calculated. Then, among the position correction amounts, the position correction amount having the largest correction amount (for the motor with the slowest response) is set as the position correction amount for all the motors.

  When the technology disclosed in Patent Document 1 is applied, the control system, for example, outputs a common command signal to the fluid pressure type and electrodynamic type vibration devices to drive each vibration device, The configuration is such that the acceleration or the like of the other excitation axis is corrected with reference to the acceleration or the like of one of the excitation axes.

However, in such a configuration in which only the correction amount is fed back, the degree of influence of characteristics (such as responsiveness) of the fluid pressure type and electrodynamic type vibration devices increases as the frequency range increases. Therefore, in the high frequency region, there is a possibility that the phase of the excitation force of the hydrostatic and electrodynamic excitation devices is shifted.
That is, in the conventional technique, the phase of the excitation force of the fluid pressure type and the electrodynamic type excitation device cannot be synchronized in the high frequency region.

JP 2010-178510 A

  The present invention has been made in view of the situation as described above, and provides a control system for an excitation device that can synchronize the excitation force of each excitation unit in a high frequency region.

  In claim 1, the fluid pressure type vibration unit that vibrates the specimen by the differential pressure of the fluid, and the electrodynamic type that vibrates the specimen by supplying a driving current to a driving coil disposed in the magnetic field. A vibration system control system for controlling an operation of a vibration device that vibrates the specimen placed on one diaphragm by a vibration unit, wherein the electrodynamic type is based on the differential pressure. A power synchronization control unit is provided that operates the vibration unit to adjust the phase of the excitation force of the electrodynamic excitation unit to the phase of the excitation force of the fluid pressure type excitation unit.

  The power synchronization control unit is calculated by the conversion unit that calculates a driving current value corresponding to the excitation force of the electrodynamic excitation unit based on the differential pressure of the fluid, and is calculated by the conversion unit. Generated by the feedforward unit that feeds forward the drive current value to the drive voltage value to the drive coil of the electrodynamic excitation unit and the electrodynamic excitation unit when the specimen is vibrated And a feedback unit that calculates the magnitude of the back electromotive voltage based on the acceleration of the specimen and feeds back the value to the drive voltage value to the drive coil of the electrodynamic excitation unit.

  The present invention makes it possible to match the phase of the excitation force of the electrodynamic excitation unit with the phase of the excitation force of the hydraulic excitation unit by using the differential pressure as a command signal to the electrodynamic excitation unit. Therefore, there is an effect that the excitation force of each excitation unit can be synchronized in the high frequency region.

The block diagram which shows the whole structure of the control system of a vibration apparatus. The block diagram which shows the structure of a power synchronous control part. The figure which shows the phase of the exciting force of the vibration apparatus of this embodiment and each vibration part. The figure which shows the equivalent circuit of an electrodynamic excitation part. The figure which shows the phase of the exciting force of each exciting part at the time of a counter electromotive voltage acting. Sectional drawing which shows the whole structure of a vibration apparatus. Sectional drawing which shows the structure of a hydraulic excitation part. The figure which shows the phase of the exciting force of each vibration part at the time of sending a command signal simultaneously to each vibration part.

  Below, the control system 1 of the vibration apparatus 10 of this embodiment is demonstrated.

  As shown in FIG. 1, the control system 1 (hereinafter simply referred to as “control system 1”) of the vibration exciter 10 (see FIG. 6) is a hybrid type that combines hydraulic and electrodynamic exciters. This is used to control the operation of the vibration exciter.

First, the configuration of the vibration device 10 will be described.
As shown in FIG. 6, the vibration device 10 is used for a vibration test or the like of the specimen W and vibrates the specimen W. The vibration device 10 includes a diaphragm 20, a hydraulic vibration unit 30, an electrodynamic vibration unit 40, and the like.

  In the following, for convenience of explanation, the “vertical direction of the vibration device 10” is defined with reference to the vertical direction of the paper surface in FIG.

  The upper part of the diaphragm 20 is formed in a substantially disc shape. The lower part of the diaphragm 20 extends downward from the upper part of the diaphragm 20 while reducing the diameter toward the center of the diaphragm 20. The lower end portion of the diaphragm 20 is connected to the upper end portion of the excitation shaft 33. A specimen W is placed on the upper surface of the diaphragm 20.

The specimen W of this embodiment is assumed to be an automobile having a different weight (for example, a small car or a large car), but is not limited to this.
When the specimen W is an automobile as in the present embodiment, each wheel of the automobile is placed on the diaphragm 20 of the plurality of vibration devices 10.

  The hydraulic exciter 30 excites the specimen W with hydraulic pressure. The hydraulic vibration unit 30 is located inside the electrodynamic vibration unit 40. As shown in FIG. 7, the hydraulic excitation unit 30 includes a cylinder sleeve 31, a piston 32, an excitation shaft 33, two bearings 34 and 34, two hydraulic servo valves 36 and 36, and two bypass valves 38 and 38.

  The cylinder sleeve 31 is a hollow substantially cylindrical member and is located below the diaphragm 20. The cylinder sleeve 31 accommodates the piston 32 inside thereof. The upper and lower outer peripheral surfaces of the cylinder sleeve 31 are opened to the outside in two places, and the respective opening portions and the hollow portions communicate with each other.

The piston 32 has a shape that can slide in the cylinder sleeve 31 in the vertical direction. A lower end portion of the excitation shaft 33 is connected to the upper side of the piston 32. A connecting shaft 35 having the same outer diameter as that of the excitation shaft 33 is connected to the lower side of the piston 32.
Note that the piston 32, the excitation shaft 33, and the connection shaft 35 may be configured integrally.

  The excitation shaft 33 is arranged such that its axial direction is parallel to the vertical direction. The excitation shaft 33 has an upper end connected to the diaphragm 20 and supports the diaphragm 20. The outer diameter of the excitation shaft 33 is smaller than the inner diameter of the cylinder sleeve 31. That is, a predetermined gap is formed between the outer peripheral surface of the excitation shaft 33 and the inner peripheral surface of the cylinder sleeve 31.

Inside the cylinder sleeve 31, a gap between the cylinder sleeve 31 and the excitation shaft 33 is divided in the vertical direction by the piston 32, and each divided gap is formed as an oil chamber.
In the present embodiment, the upper oil chamber sandwiching the piston 32 of the cylinder sleeve 31 is formed as a first oil chamber 31a, and the lower oil chamber is formed as a second oil chamber 31b.

  Each of the bearings 34 and 34 is an existing hydraulic hydrostatic bearing, and is disposed on the upper side and the lower side of the cylinder sleeve 31, and is applied to the vibration shaft 33 and the connection shaft 36 when the specimen W is vibrated. Supports lateral loads and moments.

  The hydraulic servo valves 36 and 36 supply fluid to the oil chambers 31a and 31b, respectively.

  In addition, although the fluid supplied to each oil chamber 31a * 31b shall be oil in this embodiment, it is not limited to this, For example, water etc. may be sufficient.

Each of the hydraulic servo valves 36 and 36 is attached to the outer peripheral surface of the cylinder sleeve 31 and communicates with a hydraulic pressure source via a hose, piping, and the like.
Each of the hydraulic servo valves 36 and 36 has an internal passage communicating with each of the oil chambers 31a and 31b on the inside thereof, and on the hydraulic source side of the internal passage (on the side away from the oil chambers 31a and 31b). A plurality of ports are formed at the end.

  The hydraulic exciter 30 opens and closes each port by moving a spool 37 provided inside the respective hydraulic servo valves 36 and 36 so as to be slidable in the vertical direction, and from each port to the oil chambers 31a and 31b. And the fluid is returned from the oil chambers 31a and 31b to the hydraulic pressure source. Due to the pressure difference between the oil chambers 31a and 31b, the piston 32 is slid in the vertical direction.

  In this way, the hydraulic vibration unit 30 functions as a fluid pressure vibration unit that vibrates the specimen W by the differential pressure of the fluid.

Each of the bypass valves 38 and 38 includes a first supply path C1 that is a path for supplying fluid to the first oil chamber 31a and a second supply path C2 that is a path for supplying fluid to the second oil chamber 31b. It communicates or cancels the communication state of each of the supply paths C1 and C2.
The bypass valves 38 are located between the hydraulic servo valves 36 and 36 and the cylinder sleeve 31 in the supply paths C1 and C2, respectively.

  The supply paths C1 and C2 branch toward the bypass valves 38 and 38 in the middle of the flow direction. The branching end communicates with each bypass valve 38.

Each bypass valve 38, 38 is provided with a lock block 39 that is slidable in the vertical direction on the inner side thereof. By sliding the lock block 39 in the vertical direction, each supply valve C1, C2 communicates with each other. A certain bypass path C3 / C3 is opened and closed.
The bypass valves 38 and 38 close the bypass paths C3 and C3 when the specimen W is vibrated by the hydraulic vibration unit 30, respectively.

  As shown in FIG. 6, the electrodynamic exciter 40 excites the specimen W by the action of the magnetic field 40 a and the drive coil 43. The electrodynamic exciter 40 is connected to the upper side of the hydraulic exciter 30 via an attachment member. The electrodynamic excitation unit 40 includes a main body 41, an excitation coil 42, and a drive coil 43.

  The main body 41 is a substantially cylindrical member that can accommodate the hydraulic excitation unit 30 therein. The upper side of the main body 41 is formed as an accommodating portion 41 a that protrudes inward in the radial direction of the main body 41.

The accommodating portion 41a is formed with a hollow portion that is formed substantially continuously in an annular shape along the shape of the accommodating portion 41a while the cross-sectional shape along the cylinder axis direction of the main body 41 is substantially rectangular. A gap portion 41b is formed on the upper side of the housing portion 41a.
The clearance 41b is an opening of the main body 41 that is formed in a substantially annular shape when the main body 41 is viewed from above, and communicates with the hollow portion of the housing portion 41a.
The accommodating part 41a is comprised with a magnetic body (for example, iron etc.).

  The exciting coil 42 is annularly arranged in the accommodating portion 41a in a state of being arranged along the vertical direction, and an exciting current (DC current) is supplied from a predetermined power source.

  The upper end of the drive coil 43 is coupled to the outer end of the diaphragm 20 via a coil holder 43a. The lower end portion of the drive coil 43 is disposed in a gap formed between the accommodating portion 41a and the exciting coil 42 through the gap portion 41b.

The electrodynamic exciter 40 excites the accommodating part 41 a by supplying an exciting current to the exciting coil 42, and forms a magnetic field 40 a orthogonal to the gap 41 b by the exciting coil 42. At this time, the drive coil 43 is disposed in the magnetic field 40a orthogonal to the gap 41b.
Then, the electrodynamic excitation unit 40 reciprocates the drive coil 43 in the vertical direction by supplying a drive current to the drive coil 43 to vibrate the specimen W.

  In this way, the vibration device 10 vibrates the specimen W placed on one diaphragm 20 by the vibration units 30 and 40.

The maximum excitation force of each of the excitation units 30 and 40 is set to be smaller than the maximum excitation force of the excitation device 10. Each of the vibration units 30 and 40 according to the present embodiment is configured to be able to vibrate up to 50% of the maximum vibration force of the vibration device 10.
Accordingly, each of the vibration units 30 and 40 has a smaller capacity than each of the vibration units 30 and 40 that can output a vibration force corresponding to the maximum vibration force of the vibration device 10.

  The vibration exciter 10 according to the present embodiment is configured to apply each vibration when the load is high (more specifically, when the specimen W is vibrated with a vibration force larger than the maximum vibration force of the hydraulic vibration unit 30). The specimen W is vibrated with the vibration units 30 and 40. At this time, the specimen W is vibrated by synchronizing the vibration forces F1 and F2 of the vibration units 30 and 40.

  That is, the vibration device 10 is a hybrid vibration device that can achieve both high vibration force and high-frequency vibration, and can improve energy efficiency in accordance with the vibration force.

  Here, “synchronizing the excitation forces F1 and F2 of the excitation units 30 and 40” means that the excitation forces F1 and F2 of the excitation units 30 and 40 have phases T1 and F2, as shown in FIG. This means that T2s are matched with each other or each phase difference is reduced to a practical range.

As shown in FIG. 6, when the specimen W is vibrated by each of the vibrators 30 and 40, the hydraulic vibrator 30 vibrates the specimen W with the maximum vibratory force, The vibration unit 40 supplements the remaining vibration force (see the vibration force F of the vibration device 10 and the vibration forces F1 and F2 of the vibration units 30 and 40 shown in FIG. 6).
For example, when the specimen W is vibrated with 120% of the maximum vibration force of the hydraulic vibration unit 30, the hydraulic vibration unit 30 is 100%, and the electrodynamic vibration unit 40 is the remaining 20%. % Excitation force is output.

Here, the vibration units 30 and 40 have different characteristics such as responsiveness (time from issuing a command signal to starting movement).
Therefore, when a command signal is simultaneously output to each of the vibration units 30 and 40, as shown in FIG. 8, a shift occurs in the phases T1 and T2 of the vibration forces F1 and F2 of the vibration units 30 and 40. That is, the excitation forces F1 and F2 of the excitation units 30 and 40 cannot be synchronized, and power loss occurs.

  The control system 1 controls the operation of the vibration exciter 10. As shown in FIG. 1, the control system 1 includes a hydraulic pressure control unit 2 and a power synchronization control unit 3.

  The hydraulic control unit 2 operates the hydraulic excitation unit 30. The hydraulic control unit 2 generates a command signal (servo command) based on a control signal such as an acceleration signal or a displacement signal (see the control device and S / V shown in FIG. 1). Then, the hydraulic control unit 2 operates the hydraulic excitation unit 30 based on the command signal (see H-ACT shown in FIG. 1).

  The control system 1 feeds back the speed (dx / dt) of the specimen W to the hydraulic vibration unit 30, and feeds back the position vector x, speed, etc. of the specimen W to the control signal, and responds to the command signal. Performs vibration operation.

When the vibration force F1 of the hydraulic vibration unit 30 is P1, the pressure of the first oil chamber 31a, the pressure of the second oil chamber 31b is P2, the differential pressure is PL, and the effective sectional area of the piston 32 is A. It is calculated | required by the following formula | equation (1) (refer FIG. 7).
F1 = (P1-P2) × A = PL × A (1)

That is, in the hydraulic excitation unit 30, the excitation force F1 corresponds to the differential pressure PL.
In the control system 1, the differential pressure PL is measured by an existing pressure sensor or the like. Further, the measured differential pressure PL is input to the conversion unit 4 of the power synchronization control unit 3.

  The power synchronization control unit 3 adjusts the phase T2 of the excitation force F2 of the electrodynamic excitation unit 40 to the phase T1 of the excitation force F1 of the hydraulic excitation unit 30 and uses a desired excitation force for the specimen. The operation of the electrodynamic excitation unit 40 is controlled so as to vibrate W. As shown in FIG. 2, the power synchronization control unit 3 includes a conversion unit 4, a feedforward unit 5, an electrodynamic control unit 6, and the like, and a feedback unit 7.

  The conversion unit 4 uses the differential pressure PL as an input value, calculates the magnitude of the excitation force F2 of the electrodynamic excitation unit 40 based on the input differential pressure PL, and calculates the calculated electrodynamic excitation unit A drive current value i corresponding to 40 excitation force F2 is output.

The excitation force F2 of the electrodynamic excitation unit 40 is such that the magnetic flux density of the gap 41b is B, the length of the drive coil 43 is l, the drive current value is i, the magnetic flux density B and the length l of the drive coil 43 are When the product of Ψ is Ψ, the following equation (2) is obtained.
F2 = B × l × i = Ψ × i (2)

The electrodynamic exciter 40 excites the specimen W by supplying a drive current to the drive coil 43 disposed in the magnetic field 40a. That is, the magnetic flux density B and the length l of the drive coil 43 are constant values.
That is, in the electrodynamic excitation unit 40, the excitation force F2 corresponds to the drive current value i.

When the specimen W is vibrated by each of the vibrators 30 and 40, the vibration force F2 of the electrodynamic vibrator 40 is equal to the vibration force F when the specimen W is vibrated and the hydraulic vibrator. 30 excitation force F1.
Specifically, when the test specimen W is vibrated with a 10 KN vibration force, if the hydraulic vibration unit 30 outputs a vibration force of 8 KN, the electrodynamic vibration unit 40 generates 2 KN vibration. Output force.

  Hereinafter, the ratio of the excitation force F2 of the electrodynamic excitation unit 40 to the excitation force F1 of the hydraulic excitation unit 30 will be referred to as “distribution coefficient γ”.

The converter 4 calculates the excitation force F2 of the electrodynamic excitation unit 40 based on the differential pressure PL and the distribution coefficient γ. Specifically, the excitation force F1 of the hydraulic excitation unit 30 is calculated from the differential pressure PL based on the above equation (1), and the calculation result is multiplied by the distribution coefficient γ.
And the conversion part 4 outputs the drive current value i corresponding to the excitation force F2 of the electrodynamic excitation part 40 calculated based on the said Formula (2).
The output drive current value i is input to the feedforward unit 5.

The feedforward unit 5 feeds the drive current value i calculated by the conversion unit 4 to the drive voltage value e to the drive coil 43 of the electrodynamic excitation unit 40.
The feedforward unit 5 performs a predetermined calculation on the input drive current value i and outputs a drive voltage value e. The output drive voltage value e is input to the electrodynamic control unit 6.
The contents of calculation by the feedforward unit 5 will be described later.

  The electrodynamic control unit 6 operates the electrodynamic excitation unit 40 based on the input drive voltage value e.

  As shown in FIG. 4, in the equivalent circuit of the electrodynamic excitation unit 40, the resistance R of the drive coil 43 and the inductance L of the drive coil 43 are arranged in series, and the drive coil 43 with respect to the drive voltage value e. The counter electromotive voltage Eb (self-induced electromotive force that hinders increase / decrease in drive current) acts on.

  The counter electromotive voltage Eb is obtained by the product of the length l of the drive coil 43, the magnetic flux density B, and the speed of the specimen W.

For this reason, when the position vector of the specimen W is x and the time is t, the drive voltage value e applied to the equivalent circuit of the electrodynamic exciter 40 is obtained by the following equation (3).
e = L × di / dt + R × i + Eb = L × di / dt + R × i + Ψ × dx / dt (3)
The calculation performed by the electrodynamic control unit 6 shown in FIG. 2 corresponds to the right side of the above equation (3) (that is, the portion of “L × di / dt + R × i + Ψ × dx / dt” in the above equation (3)). doing. Note that “S” shown in FIG. 2 is a Laplace operator.

As described above, in the power synchronization control unit 3, the drive current value i corresponding to the differential pressure PL is calculated by the conversion unit 4, and the drive voltage value e corresponding to the calculated drive current value i is calculated by the feedforward unit 5. .
Then, the drive voltage corresponding to the drive voltage value e is applied to the equivalent circuit of the electrodynamic exciter 40 by the electrodynamic controller 6, and the drive current value i corresponding to the differential pressure PL is supplied to the drive coil 43. (Refer to the drive current value i, which is the output value of the electrodynamic control unit 6 shown in FIG. 2).
Thus, the electrodynamic excitation unit 40 vibrates the specimen W with the excitation force F2 corresponding to the differential pressure PL (see Ψ and the excitation force F2 shown in FIG. 2).

  That is, the control system 1 does not feed back the correction amount based on the acceleration of the specimen W or the like to the drive voltage value e, but feeds forward the drive voltage value e corresponding to the differential pressure PL in advance. The unit 40 is configured to operate.

As a result, the control system 1 can match the phase of the drive current value i to the phase of the differential pressure PL without being affected by the characteristics (responsiveness, etc.) of the excitation units 30 and 40.
The differential pressure PL and the drive current value i correspond to the excitation forces F1 and F2 of the excitation units 30 and 40, respectively. For this reason, there is no phase difference between the excitation forces F1 and F2 of the excitation units 30 and 40, and the excitation forces F1 and F2 of the excitation units 30 and 40 can be synchronized.

  Thus, as shown in FIG. 3, the power synchronization control unit 3 operates the electrodynamic excitation unit 40 based on the differential pressure PL and sets the phase T1 of the excitation force F1 of the hydraulic excitation unit 30. The phase T2 of the excitation force F2 of the electrodynamic excitation unit 40 is matched (or each phase difference is reduced until the practical range is reached).

If the magnitude of the excitation force F applied to the specimen W changes, the drive current value i that is an input value to the feedforward unit 5 also changes depending on the distribution coefficient γ.
When the frequency changes, the differential pressure PL input to the conversion unit 4 of the power synchronization control unit 3 changes according to the frequency.

  That is, the control system 1 synchronizes the excitation forces F1 and F2 of the excitation units 30 and 40 without being affected by the characteristics of the excitation units 30 and 40 in any excitation force region or frequency region. it can.

  According to this, the control system 1 can synchronize the excitation forces F1 and F2 of the excitation units 30 and 40 with each other in the high frequency region, and can vibrate the specimen W without generating power loss (see FIG. 3). (See the phase T of the excitation force F of the excitation device 10 shown).

As described above, in the electrodynamic control unit 6, the counter electromotive voltage Eb acts on the drive voltage value e (see the above formula (3)).
That is, in the electrodynamic control unit 6, the transfer characteristic from the drive voltage value e to the drive current value i changes depending on the counter electromotive voltage Eb (that is, the load on the specimen W).

If the back electromotive force Eb is not taken into account in the feedforward unit 5, the excitation force F2 of the electrodynamic excitation unit 40 is reduced by the amount that the counter electromotive voltage Eb acts, and the phase T2 is also shifted. End up.
That is, as shown in FIG. 5, in the phase T2 of the excitation force F2 of the electrodynamic excitation unit 40, the amplitude becomes smaller than the desired amplitude (the electrodynamic type indicated by the two-dot chain line in FIG. 5). (See phase T2 of excitation force F2 of excitation unit 40). Further, the phase T2 of the excitation force F2 of the electrodynamic excitation unit 40 is shifted from the phase T1 of the excitation force F1 of the hydraulic excitation unit 30 by a predetermined time.

  That is, when the drive voltage value e corresponding to the differential pressure PL is fed forward to the electrodynamic control unit 6 as in the present embodiment, the control system 1 preliminarily considers the influence level of the counter electromotive voltage Eb. Must be input to the electrodynamic control unit 6.

As shown in FIG. 2, the feedback unit 7 is for correcting fluctuations in the drive voltage value e due to the back electromotive voltage Eb.
The control system 1 measures the acceleration a of the specimen W using an existing acceleration sensor, and inputs the measured acceleration a to the feedback unit 7.

The feedback unit 7 calculates the velocity by integrating the acceleration a of the specimen W with time (see 1 / S shown in FIG. 2).
Then, the feedback unit 7 calculates the magnitude of the back electromotive voltage Eb from the product of the length l of the drive coil 43, the magnetic flux density B, and the calculated speed (see Ψ shown inside the feedback unit 7 in FIG. 2). ). The calculation result is added to the drive voltage value e that is the output value of the feedforward unit 5.

Thus, the feedback unit 7 calculates the magnitude of the back electromotive voltage Eb generated by the electrodynamic excitation unit 40 when the specimen W is vibrated based on the acceleration a of the specimen W.
The feedback unit 7 feeds back the calculated back electromotive voltage Eb to the drive voltage value e to the drive coil 43.

In this way, the feedback unit 7 corrects the fluctuation of the drive voltage value e due to the counter electromotive voltage Eb. That is, the feedback unit 7 cancels the influence of the counter electromotive voltage Eb that acts on the drive voltage value e.
By performing such feedback control of the back electromotive force Eb, the above equation (3) can be transformed into the following equation (4).
e = L × di / dt + R × i (4)

  As is clear from the above equation (4), by performing feedback control of the counter electromotive voltage Eb, the feedforward unit 5 does not need to consider the influence of the counter electromotive voltage Eb.

  Therefore, the feedforward unit 5 may calculate the drive voltage value e corresponding to the drive current value i based on the above equation (4). That is, the feedforward unit 5 calculates the inverse transfer function of the above equation (4).

  According to this, the electrodynamic control unit 6 has a drive current value i (electrodynamic) having the same magnitude as the drive current value i (the drive current value i that is an input value of the feedforward unit 5) corresponding to the differential pressure PL. A drive current value i) that is an output value of the control unit 6 can be supplied to the drive coil 43.

Therefore, the control system 1 can control the operation of the electrodynamic excitation unit 40 so as to vibrate the specimen W with a desired excitation force F2. That is, as shown in FIG. 3, a desired amplitude can be set in the phase T2 of the excitation force F2 of the electrodynamic excitation unit 40.
Further, the deviation of the phase T2 of the excitation force F2 of the electrodynamic excitation unit 40 from the phase T1 of the excitation force F1 of the hydraulic excitation unit 30 can be reduced.

The control system 1 does not use the drive voltage value e as a command signal for the hydraulic exciter 30 but uses the differential pressure PL as a command signal for the electrodynamic exciter 40 as in this embodiment. It is preferable.
This is because the response of the electrodynamic excitation unit 40 is higher than the response of the hydraulic excitation unit 30, and the electrodynamic excitation unit 40 has linearity (that is, the drive current value). This is because the desired excitation force F2 is reliably obtained only by changing i).

  That is, by using the differential pressure PL as a command signal for the electrodynamic excitation unit 40, the configuration of the control system 1 can be simplified, and the phase difference between the excitation forces F1 and F2 of the excitation units 30 and 40 can be simplified. Can be made smaller.

Moreover, it is preferable that the electrodynamic excitation part 40 is a structure which switches an exciting current value in steps according to the magnitude | size of the excitation force F2 from a viewpoint that energy efficiency can be improved more.
If the exciting current value is changed, the magnitude of the magnetic flux density B changes. In this case, it is necessary to change the drive current value i by the amount of the changed magnetic flux density B (see the above formula (2)).

Even in such a case, according to the control system 1, the drive voltage value e can be calculated with the magnetic flux density B changed in the feedforward unit 5. That is, even when the excitation current value is switched according to the magnitude of the excitation force F2 of the electrodynamic excitation unit 40, the operation of the excitation device 10 can be controlled by the control system 1.
Therefore, the energy efficiency of the vibration exciter 10 whose operation is controlled by the control system 1 can be further improved.

Here, in the prior art, it is necessary to measure acceleration and the like with each of the fluid pressure type and the electrodynamic type vibration devices. Therefore, it has two input points for the specimen W.
In this case, it is not possible to manage how much acceleration and displacement are applied at each input point due to the influence of the characteristics (for example, mass, spring constant, etc.) of the specimen W.

  On the other hand, in the control system 1 of the present embodiment, in order to synchronize the excitation forces F1 and F2 of the respective excitation units 30 and 40, it is not necessary to measure the acceleration and the like by each of the excitation units 30 and 40.

Therefore, the vibration exciter 10 whose operation is controlled by the control system 1 can have one input point from each of the vibration units 30 and 40 to the specimen W. That is, it can be configured to vibrate the specimen W placed on one diaphragm 20 (see FIG. 6).
According to this, the desired vibration can be given to the specimen W in consideration of the characteristics of the specimen W (specifically, by the inverse transfer function of the transfer function from the input point to the output point).

  When the frequency region is low, the control system 1 may feed back the drive current value i of the drive coil 43 and compare it with the drive current value i corresponding to the differential pressure PL.

If the fed back drive current value i is different from the drive current value i corresponding to the differential pressure PL, the control system 1 considers this difference and the feedforward unit 5 drives the drive voltage value e. Is recalculated.
By comprising in this way, the phase difference of the exciting force F1 * F2 of each exciting part 30 * 40 can be made smaller.

DESCRIPTION OF SYMBOLS 1 Control system 3 Power synchronous control part 4 Conversion part 5 Feed forward part 7 Feedback part 10 Excitation apparatus 20 Diaphragm 30 Hydraulic type vibration part (fluid pressure type vibration part)
40 Electrodynamic excitation unit 40a Magnetic field 43 Drive coil e Drive voltage value i Drive current value PL Differential pressure T1 Phase of the excitation force of the hydraulic excitation unit T2 Phase of the excitation force of the electrodynamic excitation unit W Specimen

Claims (2)

A fluid pressure type vibration unit that vibrates the specimen by the differential pressure of the fluid, and an electrodynamic type vibration unit that vibrates the specimen by supplying a drive current to a drive coil disposed in the magnetic field, A vibration device control system for controlling the operation of a vibration device that vibrates the specimen placed on one diaphragm,
A power synchronous control unit that operates the electrodynamic excitation unit based on the differential pressure and matches the phase of the excitation force of the electrodynamic excitation unit with the phase of the excitation force of the fluid pressure excitation unit Comprising
Exciter control system. The power synchronization controller is
A conversion unit that calculates a drive current value corresponding to the excitation force of the electrodynamic excitation unit based on the differential pressure of the fluid;
A feedforward unit that feeds forward the drive current value calculated by the conversion unit to a drive voltage value to a drive coil of the electrodynamic excitation unit;
The magnitude of the back electromotive force generated in the electrodynamic excitation unit when the sample is vibrated is calculated based on the acceleration of the specimen, and the drive coil of the electrodynamic excitation unit is calculated. A feedback unit that feeds back to the drive voltage value;
Comprising
The control system of the vibration apparatus according to claim 1.

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