JP2966642B2 - Vibration suppression control device for working equipment in hydraulic working machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control device for suppressing the vibration of a working device such as a boom or an arm when the working device is stopped or started in a hydraulic working machine such as a hydraulic excavator or a crane.

[0002]

2. Description of the Related Art In a hydraulic working machine, for example, a hydraulic shovel, as shown in FIG. 8, a flow command by operating an operation lever 3 is input to a flow control valve 4 as a pilot pressure signal, and the operation of the flow control valve 4 is performed. Thus, the flow rate of the pressure oil supplied from the hydraulic pump 1 to the head side or the rod side of the boom cylinder 2 is controlled to control the operating speed of the boom.

In such a hydraulic working machine, when the operation lever 3 is returned to the neutral position and the boom is suddenly stopped, even after the pilot pressure signal instructs the stop and the flow control valve returns to the neutral position, the boom maintains its inertia. Therefore, the pressure oil does not stop suddenly, and the pressure oil acts as a spring in the hydraulic circuit after the flow control valve 4 to generate vibration. This vibration is transmitted to the vehicle body, causing the vehicle body to oscillate under the influence of rattling of the vehicle body, and as a result, coupled vibration of the entire vehicle body-front is generated. Further, this vibration is hardly attenuated due to its large inertia, and the vibration cannot be stopped forever. As a result, even when a delicate operation such as positioning of the tip with the bucket is required, there is a problem that the tip vibrates forever and positioning cannot be performed.

To solve such a problem, Japanese Patent Laid-Open Publication No.
In the publication 788, in a flexible structure working machine, an acceleration at the time of operation of an arm is detected by an acceleration detector, and the detected acceleration signal is passed through a filter means to pass only a primary mode acceleration signal. There has been proposed a vibration suppression control device which controls the drive of a flow control valve so as to remove a mode acceleration signal to suppress the vibration of an arm.

[0005]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. Sho 62-3478
The prior art described in Japanese Patent Publication No. 8 controls the vibration generating force itself because acceleration is a source of the vibration generating force, and is effective in suppressing vibration. However, when this technology is applied to a hydraulic working machine having a working device that requires a relatively high operation speed, for example, a hydraulic shovel, the vibration is effectively suppressed, but only the vibrating force is controlled. When the actuator is operated with a large acceleration, such as when starting up, the acceleration is suppressed, and a large acceleration cannot be obtained. Therefore, it takes time to obtain a desired speed,
The problem that operability deteriorates arises.

SUMMARY OF THE INVENTION It is an object of the present invention to supplementally supply and discharge pressure oil to a hydraulic actuator according to the acceleration and speed of the hydraulic actuator, thereby suppressing vibration at the time of stopping and starting a working device and improving operability. An object of the present invention is to provide a vibration suppression control device of a working device in a hydraulic working machine that does not deteriorate.

[0007]

In order to achieve this object, a vibration suppression control device for a working device in a hydraulic working machine according to the present invention comprises: (a) detecting a first state quantity for obtaining a thrust of a hydraulic actuator; First detecting means for performing;
(B) second detection means for detecting a second state quantity for obtaining the speed of the actuator; (c) a first state quantity detected by the first detection means and the first state quantity A first filter means for filtering any one of the actuator thrusts obtained from the above and removing a vibration component having a frequency lower than a predetermined frequency; and (d) a second filter means for detecting the second thrust force detected by the second detection means.
A second filter means for performing a filtering process on one of the state quantity and the actuator speed obtained from the second state quantity to remove a vibration component having a frequency lower than a predetermined frequency; and (e) using the first detection means. Third filter means for performing a filtering process on either the detected first state quantity or the actuator thrust obtained from the first state quantity to remove a vibration component having a predetermined frequency or more; (f) the first state quantity; and respective actuators thrust and actuator velocity obtained after treatment with the second filter means, and calculating means for calculating a command value by multiplying the gain according to the output of said third filter means; (g) the instruction Flow rate control means for supplementarily controlling the flow rate of the pressure oil supplied to and discharged from the actuator according to the value .

Preferably, the first detecting means is a pressure sensor for detecting the pressure of the actuator as the first state quantity, and the second detecting means is a displacement sensor for detecting the displacement of the actuator as the second state quantity. It is total.

[0009] Preferably, the first and third filters are provided.
Filter means for filtering the actuator thrust obtained from each of the first state quantities, and
The filtering means is for filtering the actuator speed obtained from the second state quantity.

[0010] Preferably, the arithmetic means includes a value obtained by multiplying the actuator thrust obtained after the processing by the first filter means by a gain corresponding to the output of the third filter means, and a second filter means. The command value is obtained by adding a value obtained by multiplying the actuator speed obtained after the process (1) by a gain according to the output of the third filter means.

More preferably, each of the first and second filter means is a high-pass filter for passing a vibration component having a predetermined frequency or higher, and the third filter means is for passing a steady component having a predetermined frequency or lower. It is a low-pass filter. Also, preferably, the flow control means,
Auxiliary control of the pressure oil flow is performed by the flow control valve.

[0012]

The flow rate command value is obtained by multiplying each of the actuator thrust and the actuator speed obtained after the processing by the first and second filter means by a gain according to the output of the third filter means. When the hydraulic actuator attempts to move beyond the target position due to inertia by supplementarily controlling the flow rate of the hydraulic oil supplied to and discharged from the actuator in accordance with the pressure, the damper corresponding to the thrust and speed of the damper The action is given to the hydraulic actuator to suppress vibration. Also, in the case where the flow rate command value is determined only by the thrust and the vibration is suppressed, the acceleration of the actuator cannot be increased as in the related art.
Since the flow command value is determined using both the thrust and the speed, the degree to which the acceleration is suppressed is reduced, whereby the actuator can be quickly operated and the operability is improved. Further, the flow rate command value is obtained by multiplying each of the actuator thrust and the actuator speed by a gain according to the output of the third filter means, thereby multiplying each of the actuator thrust and the actuator speed by a constant gain. When the load of the hydraulic actuator is large, the shock at the time of starting / stopping becomes large when the output of the third filter means, that is, the first state quantity corresponding to the load or the steady component of the actuator thrust. Since the gain is selected in accordance with this, optimal vibration suppression control is performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 6 in which a hydraulic excavator is used as an example of a hydraulic working machine. In FIG. 1, a hydraulic drive circuit according to the present embodiment is driven by a hydraulic pump 1 and hydraulic oil discharged from the hydraulic pump 1, and is a hydraulic actuator that drives a boom 2A of a working device, for example, a hydraulic shovel, that is, a boom cylinder. 2, a first flow control valve connected between the hydraulic pump 1 and the hydraulic actuator 2 and controlled by a pilot pressure signal by operating the operation lever 3 to control the flow rate of the pressure oil supplied to the hydraulic actuator 2 And a relief valve 5 that opens when the pressure between the pump 1 and the first flow control valve 4 exceeds a set value.

The vibration suppression control device of this embodiment is provided in the above hydraulic drive circuit, and includes a control unit 7, pressure transducers 8, 9 for detecting the head side pressure and the rod side pressure of the boom cylinder 2, respectively. A displacement meter 10 for detecting the displacement of the boom cylinder 2, that is, the position of the piston;
An electromagnetic type second flow control valve 11 is provided, and the control unit 7 inputs detection signals from the pressure transducers 8 and 9 and the displacement meter 10 to calculate a flow command value for vibration suppression, and correspond to the input signal. The control signal is output to the second flow control valve 11. Second
Is connected between the hydraulic pump 1 and the boom cylinder 2 in the same manner as the first flow control valve, and is driven by a control signal from the control unit 7 so that the boom cylinder 2
Auxiliary control of the flow rate of pressure oil supplied to and discharged from

The control unit 7 is constituted by a microcomputer, and as shown in FIG. 2, converts the pressure signals output from the pressure transducers 8 and 9 and the displacement signal output from the displacement meter 10 into digital signals. / D converter 7a,
A central processing unit (CPU) 7b, a read-only memory (ROM) 7c for storing a control procedure program, a randem access memory (RAM) 7d for temporarily storing numerical values during the operation, and an I / O for output O interface 7e and amplifier 7 connected to the above-mentioned flow control valve 11
f, 7 g.

The control unit 7 calculates the thrust of the boom cylinder 2 from the pressure signals output from the pressure transducers 8 and 9 and the boom cylinder 2 from the displacement signal output from the displacement meter 10.
Actuators calculated by calculating the velocities of the boom cylinders 2 after passing them through a high-pass filter that blocks vibration components below a predetermined frequency, and then passing the thrust of the boom cylinder 2 through a low-pass filter that removes vibration components above a predetermined frequency. The flow rate command value is obtained by multiplying the gain according to the steady component of the thrust, and the corresponding control signal is transmitted to the second flow control valve 1.
Output to 1.

Hereinafter, the operation of this embodiment will be described in detail with reference to the flowchart of the control procedure program stored in the ROM 7c shown in FIG. First, in step 100, pressure transducers 8,9 output and the output of the displacement meter 10 inputted via the A / D converter, the head-side pressure of the boom cylinder 2 P ₁ and the rod-side pressure P ₂ and the boom cylinder 2 Is stored in the RAM 7d.

[0018] Next in step 110, by multiplying the head side pressure receiving area A ₁ and the rod-side pressure-receiving area A ₂ of the boom cylinder 2 to the head side pressure P ₁ and the rod-side pressure P ₂ of the boom cylinder 2, obtains the difference Thus, the thrust F of the boom cylinder 2 is calculated.

Next, in step 120, the difference between the current displacement _Xn of the boom cylinder 2 and the displacement _Xn-1 of the boom cylinder 2 one sample time earlier is divided by the sample time Δt to obtain the boom cylinder 2 displacement. The speed V is calculated.

Next, in step 130, the thrust F and the speed V of the boom cylinder 2 are respectively passed through a high-pass filter, and a vibration component (hereinafter, referred to as a high-frequency component) _Fh and a speed V of the thrust F of the boom cylinder 2 at a predetermined frequency or higher. of a predetermined frequency or more vibration component (hereinafter, a high frequency that component) calculates the V _h. That is, high-frequency components F _h , F _h , are processed using the high-pass filter arithmetic expressions F _h = f _HPF (F) and V _h = f _HPF (V) incorporated in the control program in advance.
Find V _h .

FIG. 4 shows the concept of processing the thrust F and the speed V by the high-pass filter. When the input u (stroke) of the operation lever 3 is changed as shown in FIG. 4A while the holding pressure of the boom cylinder 2A is, for example, 100 kg / cm ² , the speed V of the boom cylinder 2A is changed as shown in FIG. And the thrust F changes as shown in FIG. That is, when the boom cylinder 2A starts and stops, the boom 2
The thrust F changes as shown in FIG. 4D due to the own weight of A, the inertia of the weight supported by the A, and the spring action of the pressure oil in the hydraulic circuit after the flow control valve 4, and the speed V also changes accordingly. It changes as shown in FIG. Applying this to the high-pass filter, the vibration components below the predetermined frequency is cut off, only the vibration component V _h and F _h due to start and stop as shown in FIG. 4 (c) and (e) is obtained. The vibration of the thrust F and the vibration of the speed V have a phase shift of 90 °.

Here, the high-frequency component Fh of the thrust after the high-pass filter matches the value obtained by removing the effect of the holding pressure from the thrust F, and corresponds to the acceleration of the boom cylinder 2 on a one-to-one basis.
That is, in the present embodiment, instead of directly detecting the acceleration that is the source of the vibrating force, the acceleration is detected by passing the thrust F through a high-pass filter and obtaining a vibration component Fh of a predetermined frequency or higher. Further, it is preferable that the predetermined frequency of the high-pass filter be set to a frequency equal to or lower than the natural frequency of the working device to be controlled in consideration of the influence as the vibrating force. In this embodiment, since the working device to be controlled includes the boom 2A and the weight supported by the boom,
The frequency is equal to or lower than the natural frequency of the whole of them, and is a value generally in the range of 1 to 3 Hz depending on the size of the hydraulic shovel.

Next, in step 140, the thrust of the boom cylinder 2 is passed through a low-pass filter to calculate a steady component of the thrust F of the boom cylinder 2 below a predetermined frequency. FIG. _4F shows the signal component _Fl after passing through the low-pass filter. This signal component Fl coincides with the steady state holding pressure level, that is, the load. Here, the predetermined frequency of the low-pass filter is generally in the range of 0.1 to 1 Hz.

Next, in step 150, the high frequency component Fh of the thrust F of the boom cylinder 2 and the high frequency component V of the speed V
_As shown in FIG. 5, _h is _multiplied by predetermined gains K _f and K _v according to the load F _l , and the two are added to calculate a flow command value Δq. Output to the control valve 11 and return to the beginning.

Next, the operation and effect of this embodiment will be described with reference to FIGS. FIG. 6 shows the input u (pilot pressure) of the operation lever 3, the displacement X of the boom cylinder 2, the speed V of the boom cylinder 2, and the speed u when the boom is suddenly stopped in a hydraulic drive circuit having no conventional vibration suppression control device. The time change of the thrust F of the boom cylinder 2 is shown, and the control input Δq is also shown for reference. First, when the operation lever 3 is returned to the neutral state in order to suddenly stop the boom 2A from the state in which the boom lowering operation is being performed at a constant speed, FIG.
As shown in (a), the input u becomes 0, and the flow control valve 4 also returns to neutral. Accordingly, the boom cylinder 2 which was operating in the downward direction at a constant speed V and thrust F until then.
Attempt to stop, but due to inertia, the boom 2A does not stop suddenly and continues to lower beyond the target position as shown in FIG. 6 (c).
And the thrust F also changes as shown in FIGS. 6 (d) and 6 (e). Thereafter, in the hydraulic circuit after the flow control valve 4, the pressure oil acts as a spring, and the boom cylinder 2 is pushed back upward, the displacement X starts to increase, the speed V turns to a positive value, and the thrust F Starts to decrease. When the boom cylinder 2 is pushed back to a predetermined position, the reverse boom cylinder 2 is similarly pushed back again by the spring action of the pressure oil, the displacement X starts decreasing, the speed V turns to a negative value, and the thrust F starts to increase. The above is repeated,
Vibration occurs in the front system including the boom 2A. This vibration is applied to the vehicle body, causing the vehicle body to swing due to the backlash of the vehicle body and the like, and as a result, coupled vibration of the entire vehicle body-front is generated.

On the other hand, in the present embodiment, by passing the speed V and the thrust F of the boom cylinder 2 through a high-pass filter, a vibration component having a speed V equal to or higher than a predetermined frequency as shown by hatching in FIG. and V _h, determined vibration components F _h of the predetermined frequency or more thrust F as indicated by hatching in FIG. 7 (e), the constant component of the thrusts represented in each of these FIGS 7 (f) (load) according to F _l By multiplying the gains K _f and K _v and adding the two, a flow command value Δq as shown in FIG. 7B is calculated, and a corresponding control signal is output to the second flow control valve 11. .

In response to this signal, the flow control valve 11 is driven to a predetermined opening to supply a flow rate corresponding to the flow rate command value Δq from the hydraulic pump 1 to the rod side of the boom cylinder 2 and to release the pressure oil on the head side. It is discharged to the tank 12. This allows
A damper action is given to the boom cylinder 2, and the generation of vibration due to the compressibility of the pressure oil is suppressed, and the boom cylinder 2 stops.

In accordance with the present embodiment, not only the high frequency components F _h of thrust F to determine the flow rate command value Δq for vibration suppression, since also using the high-frequency component V _h of the velocity V, the following effects Is obtained.

In order to suppress the vibration, it is sufficient to determine the flow command value Δq only from the high-frequency component (acceleration) of the thrust, which is the source of the vibrating force, if attention is paid only to the purpose. However, for example, when the boom cylinder 2 is started, if the flow rate command value Δq is determined only from the high frequency component of the thrust, the acceleration is directly controlled, so that the vibration is suppressed and the acceleration itself is suppressed. Therefore, in this case, the acceleration cannot be increased, the time required to reach the desired speed becomes longer, and the operability deteriorates. In contrast, in this embodiment, not only the high-frequency component of the thrust, since the determined flow rate command value Δq also using the high-frequency component V _h of the velocity V is the result of vibration, the degree of acceleration is suppressed It becomes small, and a large acceleration can be obtained at the time of starting.

[0030] Here, on the contrary, in the case of obtaining the flow rate command value Δq from only the high frequency component V _h of the velocity V it is is impossible to completely suppress the vibration since the speed V is the result of vibration . Therefore, it is necessary to use both thrust of high-frequency components F _h and the speed of the high frequency component V _h in order to effectively suppress the vibration while obtaining the desired acceleration. The degree of influence of the vibration suppression of a high frequency component V _h and thrust of high-frequency components F _h of the speed is determined by the gain K _v, K _f,
Gain K _v, K _f is determined by the balance between the operability and improve the vibration suppression according to stationary component (load) F _l thrust.

According to this embodiment, the flow command value Δq
Gain used to determine the K _v, since K _f is determined according to the stationary component (load) F _l thrust, the following effects can be obtained.

The result of the study by the present inventors, when multiplied by a constant gain on each of the high frequency component V _h of the high frequency components F _h and the speed V of the thrust F obtaining the flow rate command value, the load of the hydraulic actuator is increased It turned out that the shock at the time of starting and stopping became large. Thrust F of the high frequency components F _h and each thrust stationary component of the high frequency component V _h of the speed V (load) gain corresponding to F _l K _v, by obtaining the flow rate command value Δq over K _f, hydraulic actuator Even when the load on the motor becomes large, the shock at the time of starting and stopping is kept small, and the optimal vibration suppression control is performed.

Therefore, according to this embodiment, the vibration of the working device can be effectively suppressed without sacrificing responsiveness and without generating a shock at the time of starting / stopping. Further, by performing a filtering process on the feedback signal, it is possible to realize a control system that does not affect the steady-state characteristics. Therefore, the vibration of the boom 2A due to the speed change (acceleration) of the boom cylinder 2 at the time of starting or stopping the boom cylinder 2 is optimally suppressed according to the load. Is required, reliable positioning can be performed, and operability is significantly improved.

In the above embodiment, a separate flow control valve from the first flow control valve 4 is provided as a flow control valve for supplementarily controlling the flow rate of the pressure oil supplied to and discharged from the hydraulic cylinder 2 according to the flow command value. Although the second flow control valve 11 is provided, the first flow control valve 4 also serves as the second flow control valve, and transmits a control signal including an operation signal from the operation lever 3 and a flow command value to the first flow rate. You may make it supply to the control valve 4. In this case, the first flow control valve 4 is preferably constituted by an electromagnetic control valve.

Further, in the above-described embodiment, the high-pass filter is incorporated as a part of the control program and configured as software. However, an external high-pass filter including an electric circuit may be used. In this case, the detection signal may be input to the external high-pass filter, and the processed vibration components F _h , F _l , and V _h may be input to the control unit to determine the flow rate command value Δq.

Further, in the above embodiment, the high-pass filter and the low-pass filter are used. However, since it is only necessary to cut off a vibration component which is not related to the vibration and is lower than a predetermined frequency, another filter such as a band-pass filter is used. Is also good.

In the embodiment shown in FIG. 1, the thrust is obtained by detecting the pressure of the boom cylinder. However, the thrust may be directly detected by using a force sensor, or an accelerometer may be provided instead of obtaining the thrust. Alternatively, the acceleration may be detected. Further, in the above embodiment, the speed was obtained by detecting the displacement of the boom cylinder, but a speedometer may be arranged to directly obtain the speed,
An actuator speed may be obtained by applying an observer of modern control theory based on the operation signal from the operation means and the actuator thrust.

In the above embodiment, the filter processing is performed after obtaining the actuator thrust, the actuator speed, and the gain from the detected state quantity. However, the filter processing is directly performed on the detected state quantity, and the filter processing is performed. The high-frequency components of the actuator thrust and the actuator speed and the gain may be obtained from the quantities.

[0039]

According to the present invention, vibrations when the speed suddenly changes, such as when the working device is stopped or started, are optimally suppressed according to the load, so that delicate operations such as positioning of the working device can be performed. Reliable positioning can be performed when necessary, and operability is significantly improved. In addition, the vibration can be effectively suppressed without sacrificing responsiveness. Furthermore, a control system that does not affect the steady-state characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a boom vibration suppression control device in a hydraulic working machine according to one embodiment of the present invention, together with a hydraulic drive circuit thereof.

FIG. 2 is a diagram showing a configuration of a control unit of the vibration suppression control device shown in FIG.

FIG. 3 is a flowchart of a control procedure program stored in a ROM of the control unit shown in FIG. 2;

FIG. 4 is a diagram illustrating the operation of a high-pass filter.

FIG. 5 is a table function for determining a control gain used in the processing in the flowchart shown in FIG. 3;

FIG. 6 shows an operation lever input in a conventional hydraulic working machine,
Control input, actuator displacement, actuator speed,
5 is a time chart showing a time change of an actuator thrust.

FIG. 7 is a time chart showing time changes of an operation lever input, a control input, an actuator displacement, an actuator speed, and an actuator thrust in the embodiment shown in FIG. 1;

FIG. 8 is a diagram showing a hydraulic drive circuit of a conventional hydraulic working machine.

[Explanation of symbols]

 Reference Signs List 1 hydraulic pump 2 boom cylinder 2A boom (working device) 7 control unit (filter means and calculation means) 8, 9 pressure transducer (first detection means) 10 displacement meter (second detection means) 11 flow control valve ( Control means)

Continuation of the front page (72) Inventor Kiyotaka Ohara 650, Kandamachi, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (56) References JP-A-4-189925 (JP, A) JP-A-5-163746 ( JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) E02F 9/20-9/22 F16F 15/02 G05D 19/02

Claims (8)

(57) [Claims] 1. A hydraulic pump, a hydraulic actuator driven by hydraulic oil discharged from the hydraulic pump and driving a working device, and connected between the hydraulic pump and the hydraulic actuator in response to an operation signal from an operation means. A vibration control device for a working device in a hydraulic working machine having a hydraulic drive circuit having a flow control valve for controlling the flow rate of hydraulic oil supplied to the hydraulic actuator. First
(B) second detection means for detecting a second state quantity for obtaining the speed of the actuator; (c) detection by the first detection means A first filter means for applying a filtering process to either the first state quantity thus obtained or the actuator thrust obtained from the first state quantity to remove a vibration component having a frequency lower than a predetermined frequency; and (d) the second filter. (E) second filter means for performing filter processing on either the second state quantity detected by the detection means or the actuator speed obtained from the second state quantity to remove a vibration component having a frequency lower than a predetermined frequency; A third filter for filtering the first state quantity detected by the first detection means or the actuator thrust obtained from the first state quantity to remove a vibration component having a predetermined frequency or more; (F Calculating means for multiplying each of the actuator thrust and actuator speed obtained after the processing by the first and second filter means by a gain according to the output of the third filter means to obtain a command value; And b) a flow control means for supplementarily controlling the flow rate of the pressure oil supplied to and discharged from the actuator in accordance with the command value. 2. The control device according to claim 1, wherein said first detecting means is a pressure sensor for detecting a pressure of said actuator as said first state quantity. A vibration suppression control device characterized by the above-mentioned. 3. The vibration suppression control device for a working device in a hydraulic working machine according to claim 1, wherein said second detecting means is a displacement meter for detecting a displacement of said actuator as said second state quantity. A vibration suppression control device characterized by the above-mentioned. 4. The control device for suppressing vibration of a working device in a hydraulic working machine according to claim 1, wherein
The filter means filters the actuator thrust obtained from the first state quantity ,
Wherein the filter means performs a filtering process on the actuator speed obtained from the second state quantity. 5. The control device according to claim 1, wherein said arithmetic means includes a third filter means for applying an actuator thrust obtained after processing by said first filter means to said third filter means. And a value obtained by multiplying the actuator speed obtained after the processing by the second filter means by a gain according to the output of the third filter means. A vibration suppression control device for obtaining the command value. 6. The vibration suppression control device for a working device in a hydraulic working machine according to claim 1, wherein
Wherein each of the filter means is a high-pass filter that passes a vibration component having a frequency equal to or higher than a predetermined frequency. 7. The vibration control apparatus for a working device in a hydraulic working machine according to claim 1, wherein said third filter means is a low-pass filter that passes a steady component having a predetermined frequency or less. Suppression control device. 8. The control device according to claim 1, wherein said flow control means performs auxiliary control of a flow rate of said pressure oil by said flow control valve. Vibration suppression control device.