JPH11343095A - Boom type working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the pressure fluctuation of a hydraulic cylinder and the vibration of a boom and the total system by controlling on the basis of the manipulated variable input by an operator and the feedback amount calculated on the basis of the pressure of the hydraulic cylinder. SOLUTION: In a hydraulic crane, a hydraulic circuit for controlling the operation of a hydraulic motor 32 controls a flow rate and the feeding direction of the pressure oil supplied from a hydraulic pump 42 as a hydraulic source by a hydraulic pilot type control valve 40 mounted between the hydraulic motor 32 and the hydraulic pump 42. A controller 60 performs the feedback of the cylinder rod pressure PR and the cylinder rod pressure PR in addition to the manipulated variable ud from the operator to obtain a control signal to control the hydraulic motor 32. Whereby the vibration of the hydraulic cylinder 20 is attenuated, and further the vibration of a boom 10 hoisted and driven by the hydraulic cylinder 10, the vibration of the suspended load 16 and further the vibration of the total system can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom type working machine such as a hydraulic crane or a hydraulic shovel provided with a hanging hook or a hanging bucket suspended on a hoisting rope, and hoisting the hoisting rope. Also, the present invention relates to a boom type working machine provided with a vibration suppressing mechanism by controlling the operation speed of a hoisting drive unit that drives the lowering.

[0002]

2. Description of the Related Art FIG. 9 shows a general configuration of a hydraulic crane as an example of a conventional boom type working machine. As shown in this figure, a general hydraulic crane has a hydraulic cylinder 2
The hoisting rope 14 passed through the rope guide sheave 12 at the tip of the boom 10 is driven up / down by a hydraulic winch 30 to be suspended at the tip of the hoisting rope 14. Suspended load 1
6 is driven up and down.

A hydraulic winch 30 for driving the hoisting rope 14 up and down is driven by a hydraulic motor 32. The hydraulic motor 32 is connected to a hydraulic pump 4 as a hydraulic source.
The operation direction and speed are controlled by a control valve 40 provided between the control valve 2 and the control valve 2. The control valve 40 includes a remote control valve 59.
The operating lever 52 is connected to the hydraulic winch 30 via the control valve 40 and the like, and the hydraulic winch 30 is driven up / down.

[0004] Such a boom-type working machine includes a boom 1
Compressiveness of the hydraulic oil in the hydraulic cylinder 20 that drives the hydraulic rope 20 up and down, the elasticity and inertia of the boom 10 and the like, and the hoisting rope 14
Due to its elasticity and the like, the system as a whole has a characteristic of easily vibrating. Moreover, since there are few elements in the vibration system that attenuate the vibration, there is a characteristic that the vibration once generated is hardly attenuated.

[0005] Therefore, in such a boom type working machine, if the lifting load 16 is driven up and down by driving the hydraulic winch 30 up and down, and if the lifting load 16 is vibrated, the vibration is generated. Easily excites the vibration of the boom 10 and further excites the vibration of the entire system.

In particular, when such vibrations of the entire system occur, the vibrations are transmitted to the hands of the operator holding the operation lever 52 at the driver's seat, and transmitted to the lever operation against the operator's will, and a larger suspension is performed. This may cause a vicious cycle of causing the load 16 to vibrate vertically.

Therefore, the operator is required to perform an operation so that vibrations in the suspended load 16 are not generated as much as possible, and further, that vibrations generated in the suspended load do not excite resonance of the boom 10 and the entire system. There was a problem that operability was poor.

[0008]

As means for suppressing the vibration of such a boom type working machine, various proposals as described below have hitherto been made.

(1) For example, by adding a mass to a working device such as a boom 10 via a link mechanism so as to prevent resonance of the entire system, vibration is passively suppressed, that is, so-called dynamic operation. There is a vibration suppression method using the principle of a vibration damper (Dynamic Damper) (JP-A-51-76759).
issue).

However, in this method, it is necessary to add a mass to a working device such as the boom 10 or the like, and there is a problem that it is against the demand for weight reduction of such a boom type working machine.

(2) Also, the working device such as the boom 10
A so-called active mass damper, in which a damper and a mass that can be driven by an actuator for vibration suppression operation are attached and the actuator is feedback-controlled in accordance with the vibration of a speed sensor attached to a working device such as the boom 10 to suppress the vibration. (Japanese Patent Application Laid-Open No. 61-60594).

However, this method has a problem that the weight is increased due to the addition of a mass and a damper to the working device, and an actuator for a vibration suppressing operation is required, resulting in a large increase in cost.

(3) An accumulator is attached to the hydraulic cylinder 20 that drives the boom 10 up and down, and the vibration of the hydraulic cylinder is suppressed by the vibration suppressing action of the accumulator, thereby reducing the vibration of the boom 10 and the entire system. There is a method of suppressing this (Japanese Patent Application Laid-Open No. 63-3709).
5).

However, in this method, the elasticity of the hydraulic cylinder 20 in the direction of expansion and contraction is reduced by the accumulator, and the natural frequency of the dynamic characteristics of the direction of expansion and contraction of the hydraulic cylinder 20 is reduced. Is not suitable as a mechanism for suppressing the vibration accompanying the operation of the hydraulic winch 30.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simple structure without adding a mass or the like for suppressing vibration while operating a hoisting driving means such as a hydraulic winch. It is an object of the present invention to provide a boom-type working machine having excellent operability with respect to hoisting drive by suppressing vibration in the above.

[0016]

In order to solve the above problems, the present invention provides a boom, a hydraulic cylinder for driving the boom up and down, and a hoisting rope passed through a rope guide sheave provided on the boom. Hoisting drive means for driving the hoisting rope up or down, operation input means for instructing the hoisting speed or hoisting speed of the hoisting drive device, and an operation amount input to the operation input means. A hoisting drive control means for forming a control signal for controlling a hoisting speed or a lowering speed with respect to the hoisting drive device, a boom type working machine, wherein a pressure detecting means for detecting a pressure of the hydraulic cylinder; Calculating a feedback amount to the control signal for suppressing the vibration of the boom based on the pressure of the hydraulic cylinder detected by the pressure detecting means. And a fed back amount calculating means, the winding drive control means is one that is configured to perform a feedback control of the winding drive unit based on the feedback amount (claim 1).

In such a boom type working machine,
As described above, when the hoisting rope is driven up / down by the hoisting driving means, the suspended load, the boom, and the vibration of the entire system are generated. According to the boom type working machine according to the present invention, The vibration state of the boom is detected as the pressure of the hydraulic cylinder for raising and lowering the boom, and a feedback amount for suppressing the vibration of the boom is calculated based on the pressure. Then, the hoisting drive means is feedback-controlled by a control signal formed by adding the feedback amount to the operation amount input by the operator via the operation input means. Fluctuation is suppressed, and vibration of the boom and the like due to the pressure fluctuation of the hydraulic cylinder and vibration of the entire system are suppressed, so that the operator does not care about the vibration in the hoisting / lowering driving operation. High operability is obtained.

As the hoisting driving means provided with a mechanism for suppressing such vibrations, a hoisting drive means comprising a hydraulic winch for driving the hoisting rope up or down by using a hydraulic motor as a driving source may be mentioned. As the hoisting drive control means for controlling the hoisting drive means constituted by the hydraulic winch as described above, the hoisting drive control means is provided between the hydraulic motor and a hydraulic pump as a hydraulic pressure source and supplied to the hydraulic motor. A control valve for controlling the flow rate of the pressure oil, and valve control means for forming a control signal for the control valve in accordance with an operation amount input to the operation input means. The control valve may be configured to perform feedback control of the control valve based on Motomeko 2).

As the pressure of the hydraulic cylinder used for calculating the feedback amount, either the cylinder head pressure or the cylinder rod pressure may be used, but the cylinder head pressure of the hydraulic cylinder and the cylinder rod pressure are canceled. The load on the hydraulic cylinder,
Furthermore, since the vibration state of the boom can be detected, it is desirable to use the differential pressure between the cylinder head pressure and the cylinder rod pressure (claim 3).

When the pressure receiving area is different between the head side and the rod side of the hydraulic cylinder, it is desirable that the differential pressure between the cylinder head pressure and the cylinder rod pressure be determined in consideration of the ratio of these pressure receiving areas.

In the process of calculating the feedback amount from the hydraulic cylinder pressure thus detected, it is desirable to extract the fluctuation component from the hydraulic cylinder pressure and calculate the feedback amount based on the fluctuation component. Item 4).

With this configuration, the weight component of the hydraulic cylinder, such as the weight of the boom, is removed as a steady component, and the feedback amount is calculated based only on the fluctuation component representing the vibration state. In addition, the effect of suppressing the fluctuation of the boom by reducing the pressure fluctuation of the hydraulic cylinder is enhanced.

As described above, as a means for extracting a fluctuation component from the pressure of the hydraulic cylinder, a steady component such as a self-weight pressure component of a boom or the like is calculated from a work state such as a boom undulation angle or a hanging load detected by a sensor. A method of obtaining this value by subtracting this value from the detected value of the hydraulic cylinder pressure,
Alternatively, as a simple method, a method of performing a filtering process on a pressure of a hydraulic cylinder to remove a low-frequency component below a predetermined frequency including a steady-state component and extracting a fluctuation component in a high-frequency range can be cited. Item 5).

According to the method of performing the filtering process, since the steady-state component such as the self-weight pressure component of the boom changes every moment in accordance with the working state, the boom or the like depends on the working state detected by the above-described sensor. In the method of calculating the steady-state component such as the self-weight component, an error that easily occurs can be absorbed.

Specifically, as a filter for removing such a low-frequency component, a first-order advance element can be cited as a filter that can be simply configured (claim 6).

If the fluctuation component of the pressure of the hydraulic cylinder is extracted in this manner, a simple feedback amount calculating means may be a method of calculating the feedback amount by multiplying the fluctuation component by a feedback gain. Item 7).

Further, the boom type working machine having the above configuration further includes a working state detecting means for detecting a working state such as a boom angle, a boom length, a hanging load, an engine speed, and the like. It is desirable to calculate the feedback amount according to the work state.

In this way, under conditions where hunting is likely to occur, for example, when the hanging load is large or when the boom is long, the feedback amount is increased, or conversely, hunting is unlikely to occur. Under the conditions, it is possible to make adjustments to calculate the optimal feedback amount according to the work state that changes every moment, such as by configuring the feedback amount to be small.

More specifically, in the process of calculating the feedback amount from the pressure of the hydraulic cylinder by the feedback amount calculating means, if filter processing for removing low-frequency components is to be performed, parameters such as the time constant of this filter are used. If the configuration is such that the parameter is changed according to the state, or if the feedback amount is calculated by multiplying the feedback gain or the like, the parameter such as the feedback gain is configured to be changed according to the operation state. The feedback amount according to the state can be calculated.

Further, if the feedback amount is excessively large, the operation of the hydraulic winch for suppressing the vibration caused by the feedback becomes excessively large as compared with the operation of the hydraulic winch by the operation input of the operator, which causes an uncomfortable feeling for the operator. Conversely, it may impair operability and further cause higher-order self-excited vibration,
It is desirable that the feedback amount calculating means includes a limiter for setting an upper limit of the absolute value of the feedback amount.

The upper limit of the feedback amount set by the limiter may be set appropriately so as not to make the operator feel uncomfortable due to the vibration suppressing operation by the feedback and to prevent the occurrence of higher-order self-excited vibration.

The upper limit of the feedback amount may always be set to a constant value, but is preferably set according to the operation amount input by the operator.

With this arrangement, even when the operation amount of the operator is small, the operation of the hydraulic winch for suppressing the vibration due to the feedback becomes excessively large with respect to the operation of the hydraulic winch based on the operation amount. This can be prevented and operability can be improved.

Further, it is desirable that the limiter is configured such that when the operation amount of the operator is 0, the upper limit of the feedback amount is set to 0 (claim 11).

In this way, when the operator does not perform an operation input, the hydraulic winch is prevented from performing a lifting / lowering operation by feedback, and high operability and high safety are obtained. Can be.

It should be noted that the above-described configuration for suppressing vibration does not necessarily need to be applied to the operation of the hoisting drive means in both the hoisting and lowering directions, and may be applied only to the operation in one direction. Good. For example, the above configuration is applied only to the hoisting operation in which vibration is particularly a problem, and control is performed in accordance with the operation amount and the feedback amount of the operator.
For example, the control may be performed in accordance with only the operation amount input by the operator.

[0037]

FIG. 1 shows a hydraulic crane as a first embodiment of a boom type working machine according to the present invention.
Note that components having the same functions and effects as those of the conventional boom type working machine (hydraulic crane) described above are denoted by the same reference numerals.

The hydraulic crane includes a boom 10 driven up and down by a hydraulic cylinder 20.
The hoisting rope 14 passed through the rope guide sheave 12 provided at a substantially end of the hoist 0 is driven up / down by a hydraulic winch 30 having a hoisting drum 34 driven by a hydraulic motor 32. By driving the hydraulic winch 30, the suspended load 16 suspended at the tip of the hoisting rope 14 is driven up and down.

As shown in the figure, the hydraulic circuit for controlling the operation of the hydraulic motor 32 controls the flow rate and the direction of the hydraulic oil supplied from the hydraulic pump 42 as a hydraulic source by controlling the hydraulic motor 32 and the hydraulic pump. The control valve 40 is configured to be controlled by a hydraulic pilot type control valve 40 disposed between the control valve 42 and the control valve 42.

The control valve 40 is controlled by electromagnetic proportional pilot pressure reducing valves 44 and 46. The pilot pressure reducing valves 44 and 46 are controlled by a control signal from a controller 60 constituted by an electronic computer. Has become.

On the other hand, the operator operates the operation lever 52 which is an operation input means, so that the hydraulic motor 32 is operated.
Command the supply flow rate of hydraulic oil to The operation amount u _d inputted to the operation lever 52, are input is detected by the lever sensor 54 to the controller 60. That is, in this apparatus, the operation amount u _d by the operator, the pilot reducing valve 44, 46 via the controller 60, control valve 40, is transmitted to the hydraulic motor 32, hoisting / winding under operation of the hoisting rope 14 Is performed, and the suspended load 16 is configured to operate in the vertical direction.

The hydraulic cylinder 20 is configured to be controlled by a hydraulic circuit (not shown), and the boom 10 is moved to a desired angle by the hydraulic cylinder 20. A cylinder head pressure sensor 24 and a cylinder rod pressure sensor 26 are disposed as pressure detection means in the head-side and rod-side conduits of the hydraulic cylinder 20, respectively. The cylinder head pressure P _H and the cylinder rod pressure P _R detected by these sensors are used to detect the vibration state of the hydraulic cylinder 20 and, consequently, the vibration state of the boom 10 from the change over time. _H and the cylinder rod pressure P _R is adapted to be input to the controller 60.

[0043] This device, as will be described later, the controller 60, in addition to the operation amount u _d from the operator described above, the control signal by feeding back these cylinder head pressure P _H and the cylinder rod pressure P _R By controlling the hydraulic motor 32 with this control signal,
The vibration of the hydraulic cylinder 20 is attenuated, and the vibration of the boom 10 driven up and down by the hydraulic cylinder 20, the vibration of the suspended load 16 suspended on the hoisting rope 14, and the vibration of the entire system are obtained. It has become.

Further, in this apparatus, a boom angle sensor 71 for detecting a boom angle θ and a boom length sensor 7 for detecting a boom length R are provided as working state detecting means.
2. A suspension load sensor 73 for detecting the suspension load T and an engine speed sensor 74 for detecting the engine speed ω are provided. The detection signals of these sensors 71, 72, 73, 74 are also input to the controller 60. Is done.

In FIG. 1, reference numeral 36 denotes the suspended load 16.
Counterbalance valve to prevent sudden drop
Reference numerals 5 and 47 denote amplifiers for amplifying the control amount u output from the controller 60 and transmitting the amplified control amount u to the pilot pressure reducing valves 44 and 46.

Next, the controller 60 will be described. The controller 60 controls each of the sensors 24, 26, 5
A / D converter for digitally converting signals input from 4, 71, 72, 73, 74, an arithmetic circuit, a storage device, and a D / A converter for analog-converting a control amount u to pilot pressure reducing valves 44, 46 It is composed of

FIG. 2 shows an outline of a process of calculating the control amount u in the controller 60.

As shown in FIG.
In the process of calculating the control amount u at 0, the cylinder head pressure P
A cylinder pressure calculation process 61 calculates the hydraulic cylinder differential pressure P _L from the _H and the cylinder rod pressure P _R, the variation component extraction process 62 to extract the fluctuation component [Delta] P _L from the cylinder pressure difference P _L, the cylinder a gain adjustment process 63 for calculating the feedback amount u _fb multiplied by the feedback gain K _PL on the differential pressure fluctuation component [Delta] P _L, a limiter process 64 for adjusting the amount of feedback u _fb below a predetermined upper limit value,
It consists control amount calculating step 65. for calculating a control amount u feedback quantity u _fb thus calculated by subtracting from the operation amount u _d by the operator.

Hereinafter, each of these steps will be described.

The cylinder differential pressure calculating step 61 calculates the cylinder differential pressure P _L from the cylinder head pressure P _H detected by the cylinder head pressure sensor 24 and the cylinder rod pressure P _R detected by the cylinder rod pressure sensor 26. This is the process of calculating.

The cylinder head pressure P _H and the cylinder rod pressure P _R are pressures that apply a driving force to the rod 22 in the hydraulic cylinder 20 in directions opposite to each other.
The cylinder differential pressure P _L calculated as the difference indicates the magnitude of the load applied from the boom 10 to the hydraulic cylinder 20.

Therefore, in order to obtain the cylinder pressure difference P _L by canceling the driving forces in the opposite directions caused by the cylinder head pressure P _H and the cylinder rod pressure P _R , the cylinder head side pressure receiving area A _H , taking into account the case where the pressure receiving area a _R of the side are different, the cylinder pressure difference P _L is calculated from the following equation.

[0053]

P _L = P _H − (A _R / A _H ) · P _R (1) The controller 60 detects the pressure of the hydraulic cylinder 20 at the point of performing the cylinder pressure difference calculation process 61. It forms part of the pressure detecting means.

The variable component extracting step 62 calculates the variable component ΔP _L from the cylinder differential pressure P _L calculated as described above.
Is the process of extracting

The hydraulic cylinder 2 for driving the boom 10 up and down
At 0, the weight of the boom 10 and the suspended load 16 and the like acts even in the stop state, so that the pressure (self-weight pressure) due to the weight of the boom 10 and the like constantly acts on the hydraulic cylinder 20. are but component representing the vibration of the hydraulic cylinder 20 (vibration component of the boom 10), of the cylinder differential pressure P _L, which is the fluctuation component is removed such self pressure component (stationary component).

Therefore, in this variable component extraction process 62,
By removing the own weight component from the cylinder differential pressure P _L calculated as described above, a fluctuation component ΔP _L representing the vibration of the hydraulic cylinder 20 is extracted.

As a method for extracting the cylinder differential pressure fluctuation component ΔP _L , the cylinder differential pressure P _{L at} each time is determined based on the work state such as the boom undulation angle θ detected by each sensor.
The specific weight value of the self-weight component is calculated, and the self-weight component thus calculated is subtracted from the cylinder pressure difference P _L to extract the fluctuation component ΔP _L. However, in this method, it is difficult to accurately obtain the own weight component at each time due to a detection error of a work state that changes with time, and the obtained fluctuation component ΔP _L includes a relatively large error. There is a problem that it is easy to become something.

[0058] Therefore, here, as a method capable of absorbing such an error, the cylinder pressure difference P with respect to _L, by using a high-pass filter except for the predetermined frequency or lower frequency components, cylinder differential pressure variation component [Delta] P _L Is extracted.

The cylinder pressure difference fluctuation component ΔP _L can be extracted by such a high-pass filter in general because the own weight pressure component is a low-frequency component having a small change rate, while the fluctuation component causing vibration is This is because it is a high frequency component.

As a specific high-pass filter, a filter having a simple configuration composed of a first-order advanced element having a time constant of T as represented by the following equation can be given.

[0061]

## EQU2 ## G (s) = Ts / (1 + Ts) (2) Even when such a filter composed of a primary lead element is used, the boom undulation angle θ, the boom length R, the suspension load In order to calculate the feedback amount according to the work state such as T and the engine speed ω, it is desirable to adjust the time constant T according to the work state. For example, when the boom undulation angle θ is small, when the boom length R is long, when the hanging load T is large, vibration is likely to occur, so the time constant T is increased to increase the vibration suppression effect, and in other cases, desirably it is configured to enhance the response to the operation amount u _d to enter the operator to reduce the time constant T since hardly occurs vibration.

[0062] Gain adjustment process 63, multiplied by the feedback gain K _PL to the cylinder differential pressure fluctuation component [Delta] P _L which is calculated as described above, the magnitude of the feedback amount u _fb with respect to the operation amount u _d entered by the operator Is the process of adjusting.

Specifically, the feedback amount u _fb is calculated by the following equation.

[0064]

U _fb = K _PL · ΔP _L (3) The feedback gain K _PL may be fixed to a constant value as long as the feedback gain K _PL can suppress vibration of the hydraulic cylinder 20. It is desirable to adjust the magnitude of the feedback gain K _PL according to the work state such as the undulation angle θ and calculate the feedback amount u _fb according to the work state. For example, the feedback gain K _PL is increased in the work state in which the vibration is likely to occur as described above to increase the vibration suppression effect, and in the work state in which the vibration is unlikely to occur, the feedback gain K _PL is reduced to reduce the input to the operator. It is desirable to increase responsiveness.

The limiter processing step 64 is a step of adjusting the feedback amount u _fb calculated as described above to a predetermined upper limit value u _lim or less.

[0066] The apparatus, in the control of the hydraulic winch 30, by performing the pressure P _H of the hydraulic cylinder _20, a feedback based on P _R, vibration and thus the boom 10 of the hydraulic cylinder 20, to suppress the vibration of the entire system, the operator of it is aimed at achieving improved operability of the operation of the hydraulic winch 30, with respect to the operation amount u _d inputting operator via the operation lever 52, is excessively larger feedback amount u _fb for suppressing the vibration On the contrary, the operator feels strange and the operability is deteriorated. Also,
If a very large feedback amount u _fb is allowed, this feedback may cause higher-order self-excited vibration.

Therefore, here, the operation amount u of the operator is
Set the upper limit u _lim of the feedback amount according to _d ,
When the feedback amount u _fb obtained by the process of calculating the above exceeds the upper limit value u _lim is the upper limit value u _lim feedback quantity u _fb.

[0068] Figure 3 shows an example of the setting of the upper limit value u _lim feedback quantity with respect to the operation amount u _d operator.

[0069] According to the settings shown in FIG. 3, if the operator of the operation amount u _d is 0, or if the operation amount u _d is very small, the upper limit value of the feedback amount u _fb is 0, No feedback is provided. This prevents the hydraulic winch 30 from automatically operating due to feedback for suppressing vibration when the operator is not performing an operation or performing only a very small operation, and high safety is achieved. Property is obtained.

[0070] The operator in the case of the operation amount u _d is small, the manipulated variable u _d feedback amount upper limit value u _lim allowed to correspond to the even is set smaller, the amount of feedback u _fb operator manipulated variable u It does not exceed _d , does not give an uncomfortable feeling to the operator, and has high operability.

[0071] Further, even when the operator of the operation amount u _d is large, the feedback amount u _fb is limited below a certain upper limit, to prevent excessive feedback,
High operability is obtained, and the occurrence of higher-order self-excited vibration due to feedback is prevented.

[0072] Control amount calculation process 65, the process of calculating the control quantity u by the by the operation amount u _d input via the operation lever 52 from the operator, pulling the feedback amount u _fb which is calculated as described above It is.

Specifically, the control amount u is calculated by the following equation.

[0074]

Equation 4] _{u = u d -u fb ... (} 4) Thus, by subtracting the component representing the vibration of the hydraulic cylinder 20 to the operation amount u _d by the operator to calculate the control variable u, hydraulic with this control quantity u By operating the winch 30 to perform the hoisting / unwinding operation of the hoisting rope 14, the vibration of the hydraulic cylinder 20, that is, the boom 10, and the vibration of the entire system can be suppressed.

Next, the vibration suppression effect by the above-described feedback control will be verified using a theoretical model.

FIG. 4 shows a hydraulic cylinder 20 for raising and lowering the boom 10 of the hydraulic crane and a hoisting rope 14 for hoisting / lifting.
3 shows a model of a system including a hydraulic winch (hoisting drum 34) that is driven down. In this model, the crane main body 19 is fixed to the ground by outriggers 18, 18, and the boom 10 is supported by pins on the crane main body 19. The hydraulic cylinder 20 has a head side connected to the crane body 19 and a rod side connected to an intermediate position of the boom 10 by a pin.
0 is driven up and down. On the other hand, the hydraulic winch (the hoisting drum 34) is attached to the crane body 19, and the rope guide sheave 1
The hoisting rope 14 for suspending the suspended load 16 from 2 is driven up / down to move the suspended load 16 in the vertical direction.

The hydraulic cylinder / winch system having such a configuration includes a boom 10, a crane body 19, and a suspended load 16.
Inertia, bending elasticity of the boom 10, hydraulic cylinder 20
Due to the compression elasticity of the working oil inside and the elasticity of the outriggers 18, 18 and the hoisting rope 14, etc., it is configured as a complex vibration system with few damping elements. Therefore, the hydraulic cylinder / hydraulic winch system forming the complicated vibration system will be replaced with a simple orthogonal cylinder system model composed of only the main vibration elements, and the discussion will proceed.

FIG. 5 shows a model of this orthogonal cylinder system. This model is composed of a vibration system composed of the inertia of the suspended load 16 expressed as a mass point and the compression elasticity of the hydraulic oil in the hydraulic cylinder 20, and the suspended load 16 moves up and down with the operation of the hydraulic winch 30. If it operates, this suspended load 16
The tension of the hoisting rope 14 fluctuates due to the above operation, and the hydraulic cylinder 20 supporting the tension of the hoisting rope 14 moves up and down.

Here, the winding amount of the hydraulic winch 30 is l,
Assuming that the absolute displacement of the hydraulic cylinder 20 is y, the suspended load 16
Is absolute displacement y + 1. Moreover, mass m of the suspended load 16, a gravitational acceleration g, both A / 2 the pressure receiving area of the head side and the rod side of the hydraulic cylinder 20, if the differential pressure on the head side and the rod side and p _a, vertical The following equation is obtained from the balance of the forces.

[0080]

In Equation 5] ^{m · d 2 (y + l} ) / dt 2 + mg = Ap a ... (5) This equation, the left side second term "mg" represents the weight of the suspended load 16. This self-weight mg, the cylinder pressure difference p _a hydraulic cylinder 20, even when the suspended load 16 is stationary, the own pressure component p ₀ in the following equation acts by the own weight mg.

[0081]

[6] _{p 0 = mg / A ... (} 6) i.e., of the cylinder pressure difference p _a in the formula (5), directly represent component vertical vibration of the suspended load 16, the cylinder pressure difference a fluctuation component excluding the self pressure component p _0. The fluctuation component p of the cylinder differential pressure is expressed by the following equation.

[0082]

P = p _a −p ₀ (7) Therefore, the equation (5) can be rewritten into the following equation by using the equations (6) and (7) and the fluctuation component p of the cylinder differential pressure. .

[0083]

M · d ² (y + 1) / dt ² = Ap (8) On the other hand, the state in which the hydraulic cylinder 20 is not performing the up / down driving of the boom 10, that is, the flow rate of the hydraulic oil in the hydraulic cylinder 20 is zero. Assuming the state, the cylinder speed d
Cylinder head side (or rod side) according to y / dt
And the rate of change of cylinder differential pressure dp / dt,
The following relationship holds.

[0084]

A (dy / dt) + Vβ (dp / dt) = 0 (9) Here, the volume of the hydraulic cylinder 20 is V, and the bulk modulus of the working oil is β.

Here, the output v in this system is set to the speed d (y + 1) / dt of the suspended load 16 as shown in the following equation.

[0086]

V = d (y + 1) / dt (10) The lifting load speed v, which is the output of this system, is the hoisting / unwinding speed dl /
dt, the hoisting / unwinding speed dl / dt of the hydraulic winch 30 is calculated by the hydraulic pump 42 as shown in the following equation.
The control amount u for the flow control valve 41 provided on the pipeline from the hydraulic winch 30 to the hydraulic motor 32 is determined.

[0087]

U = dl / dt (11) Here, the input in this system is the suspended load 16 which is the output.
Rate of d (y + l) / dt (= v) as a target value of the operation amount u _d inputting operator via the operation lever 52
And then, first, the control variable u for the hydraulic winch 30, as determined solely by the operation amount u _d by the operator, i.e., if the operator controls the flow rate control valve 41 directly (control quantity u = manipulated variable u _d) To consider.

At this time, these equations (10) and (1)
If the cylinder displacement y and the hydraulic winch hoisting amount 1 are eliminated from the equations (8) and (9) using the equation (1), the following 2 is obtained.
An expression is obtained.

[0089]

M · dv / dt = Ap (12)

[0090]

A (v−u) + Vβ (dp / dt) = 0 (13) If the cylinder differential pressure p is eliminated by Laplace transforming the equations (12) and (13), the control amount u becomes The transfer function G ₁ (s) to the suspended load speed v is obtained as in the following equation.

[0091]

[Equation 14]

The transfer function G ₁ (s) of this system shown in the equation (14) thus obtained is unstable because the first-order term of s is missing in the denominator showing the characteristic equation. It can be seen that the system easily generates vibration. In such a second-order system, the coefficient of the first-order term indicates the magnitude of the attenuation characteristic. However, since this system does not have the first-order term, it has a characteristic that is very hard to attenuate. You can see that.

Although the above discussion assumes a simple model that takes into account only the inertia of the suspended load 16 and the elasticity of the hydraulic oil in the hydraulic cylinder 20, the suspended load 1
This indicates that the actual response to an input assuming the speed of 6 is unstable, that vibration is likely to occur, and that it has characteristics that it is difficult to attenuate. Therefore, further comprising a number of vibrating element, in the actual hydraulic crane complex vibration occurs, to drive the hydraulic winch 30 only by the operation amount u _d inputted to the operation lever 52 configured (controlled variable u = manipulated variable u _d ), The operator operates with the assumption of the suspended load speed v.
The response of the actual suspended load speed v is expected to have characteristics that it is easy to vibrate and hardly attenuated.

Next, the control amount u for the hydraulic winch 30
Next, a configuration having a control side that feeds back the cylinder differential pressure p of the hydraulic cylinder 20 will be considered. Specifically, as shown in the following equation, the control variable u to the flow control valve 41 for speed command to the hydraulic winch 30 (hydraulic motor 32), the operator of the operation amount u _d, the vibration of the system The feedback amount u _fb obtained by multiplying the cylinder pressure difference p of the hydraulic cylinder 20 by the feedback gain K _p is subtracted.

[0095]

The Equation 15] _{u = u d -K p · p} ... (15) control law of equation (15), into Equation (13), if the same operation as described above, the operation amount by the operator u _d
The transfer function G ₂ (s) from to the load speed v is given by

[0096]

(Equation 16)

The transfer function G ₂ (s) thus determined
Compared to the transfer function G ₁ (s) shown in the equation (14), it can be seen that the first order term of s is added to the denominator showing the characteristic equation, and that it has a vibration damping effect. That is, it can be seen that the feedback effect of the cylinder differential pressure p achieves the same damping effect as in the state in which a damper having viscosity is added.

As described above, since the magnitude of the coefficient of the first-order term of s in the characteristic equation represents the damping effect, the larger the feedback gain _Kp , the larger the damping effect.

Next, a configuration in which a feedback amount u _fb is calculated by performing a filtering process using a high-pass filter will be considered.

The filtering process using the high-pass filter extracts a fluctuation component representing the vibration of the hydraulic cylinder 20 from the component of the cylinder differential pressure p, excluding the self-weight component due to the weight of the boom 10 and the like. . Here, as such a high-pass filter,
It is assumed that a filter of a primary advance element of the time constant T is used.

[0101]

The [expression 17] G (s) = Ts / ( 1 + Ts) ... (17) cylinder pressure difference p _a detected by the sensor or the like, extracts the variation component through the filter of the first order lead element, this fluctuation component calculating a feedback amount u _fb by multiplying the feedback gain K _p, the feedback amount u _fb, by subtracting from the operation amount u _d of operator inputs to determine the control variable u to the flow rate control valve. This control law is expressed by the following equation.

[0102]

(Equation 18)

[0103] At this time, by performing the same operation as described above, the transfer function G ₃ from the operation amount u _d by the operator to the cylinder speed dy / dt (s) is given by the following equation.

[0104]

[Equation 19]

However,

[0106]

(Equation 20)

Here, the stability of the transfer function G ₃ (s) will be examined by the Hurwitz stability discrimination method. The characteristic equation of the transfer function G ₃ (s) is as follows.

[0108]

S ³ + a ₁ s ² + a ₂ s + a ₃ = 0 (21) In order for this system to be stable, all the coefficients of the characteristic equation (21) need to be positive values. Constant A,
Since V, β, and m are all positive values, if the time constant T and the feedback gain K _p of the primary advance element are set to positive values,
These coefficients are all positive values.

In order for the system to be stable, the determinant (a ₁ · a ₂ −
It is necessary that the value of a ₃ ) is positive. In this characteristic equation (21), the value of this determinant is positive as shown in the following equation.

[0110]

A ₁ · a ₂ -a ₃ = AK _p / (Vβ)> 0 (22) Therefore, if the time constant T of the primary advance element and the feedback gain K _p are set to positive values, the cylinder differential pressure By performing feedback using a high-pass filter consisting of a first-order element for p, it can be said that the stability of this system is guaranteed.

As described above, the fluctuation component is extracted from the cylinder differential pressure p of the hydraulic cylinder 20 by using the high-pass filter (Equation (17)) composed of the first-order advance element, and the feedback gain K _p is added to the fluctuation component. calculates the feedback amount u _fb by multiplying, by constituting a system for calculating a controlled variable u from the operation amount u _d by subtracting the feedback amount u _fb to be input by the operator, the stability of the system is guaranteed, vibration It can be seen that can be suppressed.

[0112] Second Embodiment Next, in the first embodiment described above, in order to prevent the relative operation amount u _d to operator input, excessive feedback is performed, electric in the controller 60 A description will be given of a second embodiment in which the limiter (limiter processing step 64) configured as a typical arithmetic processing step is realized by the configuration of a hydraulic circuit.

FIG. 6 shows a hydraulic circuit configuration of the second embodiment. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and redundant description will be omitted.

First, in this figure, looking at the hydraulic circuit configuration on the winding side of the hydraulic winch 30 of the control valve 40, the electromagnetic proportional pilot pressure reducing valve 44 on the winding side is shown.
Is directly controlled by an operation lever 55 operated by an operator. That is, the operation on the winding side is configured not to perform feedback for suppressing vibration. This is because, in a hydraulic crane or the like, the operation of hoisting the hydraulic winch 30 is less likely to generate vibrations than the operation of lowering it. This is for simplicity.

As described above, the boom type working machine according to the present invention employs a structure for suppressing vibration on only one of the hoisting side and the lowering side of the hydraulic winch 30 which is more necessary, and as a whole, The configuration may be simplified.

Next, considering the hydraulic circuit configuration for lowering the hydraulic winch 30 of the control valve 40, the lowering-side electromagnetic proportional pilot pressure reducing valve 46
As in the above-described first embodiment, the opening is controlled by the control amount u output from the controller 60. Then, the operation amount is input to the operation lever 56 from the operator u _d is inputted through the pressure sensor 58 as a secondary pressure of the hydraulic remote control valve 57 to the controller 60, the control variable u of the controller 60 outputs, this the operator of the operation amount u _d, is adapted to be calculated by adding the cylinder head pressure P _H and the feedback amount u _fb based on the cylinder rod pressure P _R or the like of the hydraulic cylinder 20.

[0117] Therefore, usually, as with the first embodiment described above, so as to suppress the vibration of the hydraulic cylinder 20 by this feedback, the operator of the operation amount u _d
The hydraulic winch 30 is controlled in accordance with.

However, the configuration of the hydraulic circuit on the lowering side of the second embodiment is based on the operation amount u input by the operator.
_d is temporarily output as the secondary pressure of the hydraulic remote control valve 57, and the secondary pressure of this hydraulic remote control valve is
This is different from the embodiment.

[0119] According to the hydraulic circuit configuration of such a lowering side, when the control quantity u of the controller 60 outputs is larger than the operation amount u _d for operator input, ie,
Even if the operator of the operation amount u _d control variable u excessive feedback amount u _fb is applied against is output, the pilot reducing valve 46, the operation amount of the operator u _d
Since the the secondary pressure of the hydraulic remote control valve 57 which is set according to the hydraulic pressure source, it does not output exceeding the operation amount u _d operator from the pilot reducing valve 46 is made. That is, since the hydraulic remote control valve 57 serving as the input means of the operator and the pilot pressure reducing valve 46 on the lowering side are connected in series, excessive feedback is prevented from being performed. Functions as a limiter.

As described above, in the above-described first embodiment, various arithmetic operations configured to be electrically performed in the controller 60 are performed, for example, with respect to the limiter in the second operation.
As shown in the embodiment, the present invention may be realized by a configuration of a hydraulic circuit. Alternatively, it may be realized by another mechanical configuration.

In the first and second embodiments, only the structure in which a hydraulic winch using a hydraulic motor as a driving source is applied as a hoisting drive means for hoisting / lowering a hoisting rope has been described. The hoisting drive means in the boom type working machine according to the present invention is not limited to such a hydraulic winch. For example, the hoisting rope is driven up / down by using an electric motor or an internal combustion engine as a drive source. The driving means may be employed.

[0122]

EXAMPLE Next, the hydraulic circuit configuration of the first embodiment (FIG. 1) is applied to a rough terrain crane with a maximum lifting load of 25 ton, and an experiment of the vibration suppression effect is actually performed to verify the effect.

The experimental conditions were as follows: boom length 16 m, suspended load 2
tf, engine speed 1500 rpm, undulation angle 55 de
g. It has been found that when the hydraulic winch 30 is driven down under this condition, a vibration of 2.8 Hz easily occurs in this system.

[0124] Therefore, this system vibration of 2.8Hz occurs, this vibration is transmitted to the operation amount u _d of the operation lever 52 via the operator input including vibration elements 2.8Hz have been made Assuming a case, the vibration state of the system with respect to the input including the vibration element is detected, and it is evaluated whether or not the resonance of the system can be prevented with respect to the input including the vibration element.

First, for comparison, a case will be examined in which the feedback of the pressure of the hydraulic cylinder 20 is not performed by setting the upper limit of the feedback amount u _fb to always be 0 by the limiter (limiter processing means 64). .

FIG. 7 shows the result when no feedback is performed.

[0127] FIG. 7 (a) represents the lever operation amount u _d by the operator. The vertical axis, the magnitude of the manipulated variable u _d, the horizontal axis represents time. As shown in this figure, the operation amount u _d by the operator, 2.8H substantially stepwise input
A vibration element of z is added.

FIG. 7B shows the feedback amount u _fb calculated based on the pressure of the hydraulic cylinder 20. Since we did not provide feedback in this experiment,
This feedback amount u _fb is always 0.

[0129] Thus, in this experiment, lever operation amount u _d is intact control valve 4 shown in FIG. 7 (a)
The control amount u becomes 0, and the hydraulic motor 32 of the hydraulic winch 30 is driven to lower based on the control amount u.

FIG. 7C shows the angular velocity d of the hoisting drum 34 of the hydraulic winch 30 with respect to the input of the control amount u.
The time response of 1 / dt is shown. As shown in this figure, the angular velocity dl /
dt, although there is an influence of the delay in the vibration and response generated in the system, it has a response that follows approximately the lever operation amount u _d.

FIG. 7D shows such a hydraulic winch 3.
0 when the operation of the hydraulic cylinder 20 is performed.
Shows the variation component [Delta] P _L of the cylinder differential pressure P _L. This fluctuation component ΔP _L is obtained by performing a high-pass filter process using a first-order advance element on the cylinder differential pressure P _L , and can be said to represent the vibration state of the boom 10 in which the hydraulic cylinder 20 is driven up and down. . As shown in this figure, this cylinder differential pressure fluctuation component ΔP _L has generated a large vibration since the drive of the hoisting winch 30 was started, and it is understood that a large vibration has occurred in the boom 10.

As assumed in this experiment, the lifting / lowering drive of the hydraulic winch 30 causes the suspended load 16 to move up and down, causing vibrations in the system. In some cases, however, in this experiment, the system resonates due to the input including this vibration, causing even larger vibration. Therefore, the operator
In order to avoid such vibrations, it is necessary to detect the generated vibrations and operate the operation lever 52 so as to suppress the vibrations, which indicates that the operability is poor.

Next, the upper limit u of the feedback amount u _fb
The _lim, the relationship shown in FIG. 3, the operation amount of the operator u _d
The case where the limiter (limiter processing means 64) is configured so as to be set according to the above and feedback of the pressure of the hydraulic cylinder 20 is considered.

FIG. 8 shows the result of this feedback.

FIG. 8A shows the operation amount u by the operator.
represents _d . The operation amount u _d is identical in input and the case without the above feedback.

FIG. 8 (b) shows the cylinder differential pressure fluctuation component ΔP
_L indicates the feedback amount u _fb calculated based on _L (FIG. 8D described later). Note that, as shown in this figure, the amplitude of the feedback amount u _fb is suppressed within a predetermined range, but this is controlled by a limiter process.
This is because the feedback amount u _fb is adjusted to be equal to or less than the predetermined upper limit value u _lim so as not to impair operability due to excessive feedback.

[0137] When performing this feedback control amount u to the control valve 40 is formed by combining a feedback quantity u _fb, and a manipulated variable u _d by the operator shown in FIG. 8 (a).

FIG. 8C shows the angular velocity d of the hoisting drum 34 of the hydraulic winch 30 in response to the input of the control amount u.
The time response of 1 / dt is shown.

As shown in FIG.
The angular velocity dl / dt, is similar to the case of not performing a feedback operation with respect to a point that is a response that follows approximately the lever operation amount u _d (the case of FIG. 7 (c)), did not do so feedback The amplitude is much smaller than in the case where That is, it is understood that a high vibration suppression effect is obtained by performing the feedback.

FIG. 8D shows such a hydraulic winch 3.
0 when the operation of the hydraulic cylinder 20 is performed.
Shows the variation component [Delta] P _L of the cylinder differential pressure P _L. This fluctuation component ΔP _L is a basis for calculating the feedback amount u _fb , and represents the vibration state of the boom 10 as described above. Also from this figure, the amplitude of the cylinder differential pressure fluctuation component ΔP _L is very small as compared with the case shown in FIG. 7D in which the feedback is not performed. It can be seen that the effect is obtained.

[0141] Thus, a high vibration suppression effect can be obtained by performing a feedback based on cylinder pressure difference variation component [Delta] P _L of the hydraulic cylinder 20, the operation amount u _d containing the vibration component is input by the operator Even in this case, the resonance of the system is prevented without amplifying the input including the vibration component. Therefore, the operator who actually performs the crane operation only has to operate the operation lever 52 while considering only obtaining a desired suspended load speed without worrying about such vibration. That is, by performing such feedback, high operability of the hydraulic winch 30 can be obtained.

[0142]

As described above, according to the boom type working machine of the present invention, the hoisting drive means is operated by the operator through the operation input means and the hydraulic cylinder representing the vibration state of the boom. Therefore, high operability can be obtained by suppressing pressure fluctuations of the hydraulic cylinder, and consequently suppressing vibration of the boom and the entire system. At this time, since the feedback system based on the pressure of the hydraulic cylinder plays the effect of suppressing vibration, it is not necessary to add a mass element, an actuator, an accumulator, etc. for suppressing vibration, and a simple configuration is required. Can be.

If the pressure difference between the inlet pressure and the outlet pressure of the hydraulic oil supplied to the hydraulic cylinder is used as the pressure of the hydraulic cylinder, the hydraulic cylinder excluding the offset between the inlet pressure and the outlet pressure can be used. The magnitude of such a load can be detected, and the accuracy of vibration suppression by feedback can be increased.

Further, a fluctuation component representing vibration is extracted from the pressure of the hydraulic cylinder, and a feedback amount is calculated based on the fluctuation component. And the like are removed as steady components, so that a higher pressure fluctuation reduction effect can be obtained.

Further, if the filtering process for removing the low frequency components below a predetermined frequency is performed on the pressure of the hydraulic cylinder, it may occur when a variable component is extracted by using the own weight component obtained from the working state. Absorb easy calculation errors,
The fluctuation component can be extracted more accurately.

Further, there is provided a work state detecting means for detecting a work state such as a boom hoisting angle, a boom length, a hanging load, an engine speed, etc., and a feedback amount is calculated according to the work state thus detected. Then, for example, under conditions where vibrations are likely to occur, the feedback amount is increased, and conversely, under conditions where vibrations are unlikely to occur, the feedback amount is reduced. Can be adjusted to calculate the optimal feedback amount in accordance with the changing work state.

In addition, if a limiter for setting the upper limit of the absolute value of the feedback amount is provided, it is possible to prevent the operability from being deteriorated due to excessive feedback and the occurrence of higher-order self-excited vibration.

In particular, if the limiter is configured so that the upper limit of the feedback amount is set according to the operation amount input by the operator, high operability can be obtained even when a minute operation is performed by the operator. Can be.

Further, if the limiter is configured such that the upper limit of the feedback amount is set to 0 when the operation amount of the operator is 0, the hydraulic winch operates by feedback when the operator does not input the operation. By doing so, high operability and high safety can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a first embodiment of a boom type working machine according to the present invention.

FIG. 2 is a configuration diagram showing a calculation process in a controller 60 of the device.

3 is a glove showing an example of the relationship between the operator of the operation amount u _d and the feedback amount upper limit value u _lim in limiter process 64 of the apparatus.

FIG. 4 is a configuration diagram showing a model of a hydraulic cylinder / hydraulic winch system of the hydraulic crane.

FIG. 5 is a configuration diagram showing a model of an orthogonal cylinder system.

FIG. 6 is a schematic view showing a second embodiment of the boom type working machine according to the present invention.

FIG. 7 is a graph showing a time response such as a cylinder differential pressure when feedback is not performed.

FIG. 8 is a graph showing a time response such as a cylinder differential pressure when feedback is performed.

FIG. 9 is a schematic view of a conventional general hydraulic crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Boom 12 Rope guide sheave 14 Hoisting rope 16 Suspended load 20 Hydraulic cylinder 24 Head side pressure sensor (pressure detecting means) 26 Rod side pressure sensor (pressure detecting means) 30 Hydraulic winch 32 Hydraulic motor 40 Control valve 42 Hydraulic pump 44, 46 Electromagnetic proportional pilot pressure reducing valve (valve control means) 52 Operation lever (operation input means) 60 Controller (valve control means, pressure detection means)

Claims (11)

[Claims] 1. A boom, a hydraulic cylinder for driving the boom up and down, a hoisting rope passed through a rope guide sheave provided on the boom, and a hoisting drive for driving the hoisting rope up and down. Means, operation input means for instructing a hoisting speed or a lowering speed of the hoisting drive device, and a hoisting speed or a lowering speed for the hoisting drive device according to an operation amount input to the operation input means. A hoisting drive control means for forming a control signal for controlling the pressure of the hydraulic cylinder, the pressure detection means for detecting the pressure of the hydraulic cylinder, the pressure of the hydraulic cylinder detected by the pressure detection means And a feedback amount calculating means for calculating a feedback amount to the control signal for suppressing the vibration of the boom based on the hoisting drive control. Stage, boom type working machine, characterized in that it is configured to perform a feedback control of the winding drive unit based on the feedback amount. 2. The boom type working machine according to claim 1, wherein the hoisting drive means is constituted by a hydraulic winch that drives the hoist rope up or down using a hydraulic motor as a drive source. A control valve provided between the hydraulic motor and a hydraulic pump as a hydraulic pressure source for controlling a flow rate of pressure oil supplied to the hydraulic motor; and an operation amount input to the operation input means. A boom-type work machine, comprising: valve control means for generating a control signal for the control valve in accordance with the control signal, wherein the valve control means performs feedback control of the control valve based on the feedback amount. 3. The boom type according to claim 1, wherein said pressure detecting means is configured to detect, as the pressure of said hydraulic cylinder, a differential pressure between a cylinder head pressure of said hydraulic cylinder and a cylinder rod pressure. Work machine. 4. The system according to claim 1, wherein the feedback amount calculating unit calculates a pressure of the hydraulic cylinder detected by the pressure detecting unit.
The system according to claim 1, wherein the variable component is extracted, and the feedback amount is calculated based on the variable component.
4. The boom type working machine according to any one of 3. 5. The feedback amount calculating means extracts a fluctuation component of the pressure of the hydraulic cylinder detected by the pressure detecting means by performing a filtering process for removing a low frequency component below a predetermined frequency. 5. The boom type working machine according to claim 4, wherein the feedback amount is calculated based on the fluctuation component. 6. The feedback amount calculating means extracts a fluctuating component of the hydraulic cylinder pressure detected by the pressure detecting means by performing a filtering process using a first-order advance element. The boom type working machine according to claim 5, wherein the feedback amount is calculated on the basis of: 7. The feedback amount calculating means is configured to calculate a value obtained by multiplying the fluctuation component by a feedback gain as the feedback amount.
7. The boom type working machine according to any one of to 6 above. 8. The boom type working machine according to claim 1, further comprising a work state detecting means for detecting a work state such as a boom angle, a boom length, a hanging load, an engine speed, and the like. A boom-type work machine configured to calculate the feedback amount according to the work state detected by the work state detection unit; 9. The boom type working machine according to claim 1, wherein said feedback amount calculating means includes a limiter for setting an upper limit of an absolute value of said feedback amount. 10. The boom type working machine according to claim 9, wherein the limiter is configured to set an upper limit of an absolute value of the feedback amount according to an operation amount of the operation input unit. 11. The boom type working machine according to claim 9, wherein the limiter is configured to set the feedback amount to 0 when the operation amount of the operation input unit is 0.