JPH11350536A - Controller of hydraulic working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly correct instruction current and flow-rate characteristics and precisely control the operation of a working device regardless of variation in every product of a hydraulic instrument and hydraulic mutual interference at the time when a plurality of hydraulic actuators are compositely operated and the operation of the working device is controlled. SOLUTION: The learning correction processing of instruction current and flow-rate characteristics is performed due to area limit excavation control by the composite operation of a boom and an arm by means of the composite operation correction calculation part of a control unit 9. The processing is changed over to a learning correction mode by a switch 7c in a state where a signal from a switch 7a instructs area limit excavation control, and the area limit excavation control is performed. The object of correction is the instruction current and flow-rate characteristics of a flow control valve for the boom 5a, and the irregularity of the instruction current and flow rate characteristics of a flow control valve 5a for the arm 5b is absorbed by the specific correction of the boom. In addition, operation speed is switched by an operation speed instruction switch 7d in the learning correction mode, and the correction value of the instruction current and flow-rate characteristics of the flow control valve 5a is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hydraulic working machine for controlling the operation of a working device by compoundly operating a plurality of hydraulic actuators, and more particularly to a multi-joint type front working machine, particularly an arm. The present invention relates to a control device for a hydraulic working machine such as a hydraulic shovel provided with a front working machine including front members such as a boom, a bucket, and the like.

[0002]

2. Description of the Related Art As an example of a hydraulic working machine that drives a working device by operating a plurality of hydraulic actuators in a complex manner,
There are construction machines such as hydraulic excavators. This construction machine
The vehicle includes a lower traveling structure, an upper revolving structure provided on the lower traveling structure, and a plurality of front members such as a boom, an arm, and a bucket, and a front working machine mounted on the upper revolving structure. In this type of construction machine, each of the front members constituting the front working machine is connected to each other by a joint and performs a rotational motion. Therefore, these front members are operated to perform straight excavation of a slope and burial of a pipe. Excavating a predetermined area in a straight line, such as depth-limited excavation, is a very difficult task.

[0003] In order to facilitate such operations, area-limited excavation control and trajectory control have been proposed. The region-limited excavation control is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-333768. In these controls, the pilot pressure of the flow control valve is adjusted by an electro-hydraulic conversion valve (for example, a proportional solenoid valve) to control the flow rate of the hydraulic oil supplied to the hydraulic cylinder and the hydraulic motor, thereby controlling the operation of the front work machine. Controlling.

In general, when operating a front working machine using an electro-hydraulic conversion valve or a flow control valve, a command value for driving a hydraulic cylinder or a hydraulic motor is based on input / output characteristics of the electro-hydraulic conversion valve or the flow control valve. Is set in the controller in advance, and is calculated and generated using the input / output characteristics. Japanese Patent Application Laid-Open No. 4-119203 proposes a method for correcting variations in input / output characteristics when calculating such a command value. In this conventional technique, an actual flow rate is obtained from an actual operation of an actuator when a certain reference command current value is given, and the actual flow rate is converted into a command current value by a command current-flow rate characteristic. Is obtained as a correction value, and the command current-flow rate characteristic is translated in parallel by the correction value to correct the variation. Further, the accuracy of correction is increased by setting a plurality of correction points.

[0005]

When performing region-limited excavation control or trajectory control, a command value for driving a hydraulic cylinder or a hydraulic motor depends on input / output characteristics of an electro-hydraulic conversion valve and a flow rate control valve preset in a controller. Therefore, in order to accurately calculate the command value and increase the control accuracy, it is necessary to accurately grasp the input / output characteristics of the electrohydraulic conversion valve and the flow control valve. However, it is inevitable that the electro-hydraulic conversion valve and the flow rate control valve have a certain degree of variation due to a processing error of the spool and the valve body and a variation in spring force. This variation appears as a decrease in control accuracy when performing the region-limited excavation control and the trajectory control.

The correction method described in Japanese Patent Application Laid-Open No. 4-119203 corrects the command current-flow rate characteristics of individual hydraulic actuators so as to match the actual characteristics. It is effective under the condition that the operation of the actuator is not interfered with, that is, in a machine having a hydraulic system with a flow control valve with pressure compensation, but the hydraulic pressure is such that the operation of an individual actuator is interfered with the operation of another actuator. The system has a problem that it is not always possible to know whether or not the correct correction has been made.

[0007] That is, the combined operation of the boom and the arm, which are the components of the front working machine, is essential in the area-limited excavation control and the trajectory control. When operating, a phenomenon occurs in which the hydraulic pressure between the respective actuators interferes. When the oil pressure between the actuators interferes like this,
There is no guarantee that the speed of each actuator will always be constant with respect to the command value due to the effect of the load acting on each actuator. In other words, the command current-flow rate characteristic usually differs between the single operation and the combined operation. As a result, when a combined operation of the boom and the arm is performed, the bucket at the tip of the arm moves on a trajectory different from the intended trajectory, and it becomes impossible to excavate the set excavation surface.

[0008] An object of the present invention is to control the operation of a working device by operating a plurality of hydraulic actuators in a combined manner, regardless of variations in hydraulic products and mutual interference of hydraulic pressure. An object of the present invention is to provide a hydraulic work machine control device that can appropriately correct the operation of a work device by appropriately correcting the operation.

[0009]

(1) In order to achieve the above object, according to the present invention, a command current value is calculated from a control value target value in accordance with a preset command current-control value characteristic,
A control device for a hydraulic work machine that controls the operation of a working device by operating a plurality of hydraulic actuators including the hydraulic actuator by operating a hydraulic actuator by switching a flow control valve using the value of the command current. In the composite operation correction instructing means, the composite operation maximum speed instruction means, and from the position information when controlling the operation of the working device by performing composite operation of the plurality of hydraulic actuators by a command from the composite operation correction instructing means A correction value calculating means for calculating an error in the control operation of the working device and obtaining a correction value of the command current-control amount characteristic based on the error; and correcting the command current-control amount characteristic using the correction value. When the correction value is obtained by the characteristic correction means and the correction value calculation means, the maximum speed specified by the composite operation maximum speed instruction means must not be exceeded. As shall and speed control means for controlling the combined operation speed of the plurality of hydraulic actuators.

As described above, the correction value is obtained from the error of the control operation of the working device by the combined operation of the plurality of hydraulic actuators by the correction value calculating means. The characteristic correction means corrects the command current-control amount characteristic by using a correction value that includes the effect of the load. The operation of the working device can be controlled with high accuracy even if there is mutual interference of hydraulic pressure due to operation.

When the correction value is obtained by the correction value calculating means, the composite operation speed of the plurality of hydraulic actuators is controlled by the speed control means so as not to exceed the maximum speed instructed by the composite operation maximum speed instruction means. Only the specific region of the command current-control amount characteristic is used in accordance with the specified maximum speed, the calculation accuracy of the correction value in the specific region is improved, and the speed control means is appropriately switched to change the correction value. , The calculation accuracy of the correction value is improved over a wide current range of the command current-control amount characteristic.

(2) To achieve the above object,
The present invention calculates a command current value from a target value of a control amount according to a preset command current-control amount characteristic, and switches a flow control valve by using the command current value to drive a hydraulic actuator. A hydraulic operation machine control device that controls the operation of a working device by performing a composite operation of a plurality of hydraulic actuators including the hydraulic actuator, wherein the composite operation correction instructing means, the composite operation speed instructing means, and the composite operation correcting instructing means are provided. From the position information at the time of controlling the operation of the working device by operating the plurality of hydraulic actuators in a combined manner, and calculating the control current error of the working device based on the error. Correction value calculating means for obtaining a correction value for the characteristic, characteristic correction means for correcting the command current-control amount characteristic using the correction value, and the correction value When determining the correction value calculation means,
Speed control means for controlling the composite operation speed of the plurality of hydraulic actuators so that the operation speed is instructed by the composite operation speed instruction means.

By providing the correction value calculating means and the characteristic correcting means in this way, as described in the above (1), there is a possibility that there is a variation between products of the hydraulic equipment and a mutual interference of hydraulic pressure due to a combined operation of a plurality of hydraulic actuators. However, the operation of the working device can be accurately controlled.

When the correction value is obtained by the correction value calculating means, the speed control means controls the composite operation speed of the plurality of hydraulic actuators so that the operation speed is instructed by the composite operation speed instruction means. Only a specific area of the command current-control amount characteristic is used in accordance with the speed, the calculation accuracy of the correction value in the specific area is improved, and the correction value is obtained by appropriately switching the speed control means. In addition, the accuracy of calculating the correction value is improved over a wide current range of the command current-control amount characteristic.

(3) In the above (1) or (2), preferably, the correction value calculating means operates the plurality of hydraulic actuators in combination to control the operation of the working device. First calculating means for comparing the current position with the target control range and calculating whether the current position is outside the target control range and on which side outside the target control range; And a second calculating means for calculating a correction value of the command current-control amount characteristic based on the result of the calculation.

As described above, when the operation of the working device is controlled by the composite operation of the plurality of hydraulic actuators by the first calculating means, the current position of the working device is compared with the target control range. By calculating whether it is out of the range or on which side outside the target control range, an error in the control operation of the working device due to the combined operation of the plurality of hydraulic actuators is obtained, and the second calculating means calculates the error. By calculating the correction value of the command current-control amount characteristic based on the calculation result, the correction value of the command current-control amount characteristic can be obtained based on the error of the control operation.

(4) In the above (3), preferably,
The working device includes a boom and an arm that constitute a multi-joint type front working machine of a construction machine, and the first arithmetic unit performs a combined operation using a boom raising / arm cloud or a boom lowering / arm dump to operate the working device. The operation is controlled by comparing the current position of the working device with the target control range when the operation is controlled, and the second calculation means determines the command current-control amount characteristic by raising the boom of the boom flow control valve. A correction value of the command current-flow rate characteristic in the direction or the boom lowering direction is calculated.

As a result, a correction value in the control operation of the working device by the combined operation of the boom raising / arm cloud or the boom lowering / arm dump is obtained.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, a hydraulic shovel is taken as an example of a hydraulic working machine, and the present invention is applied to a hydraulic shovel that performs region-limited excavation control by a combined operation of a boom and an arm.

In FIG. 1, a hydraulic drive device of a hydraulic shovel to which the present invention is applied includes a hydraulic pump 2 and a boom cylinder 3 driven by hydraulic oil from the hydraulic pump 2.
a, a plurality of hydraulic actuators including an arm cylinder 3b, a bucket cylinder 3c, a swing motor 3d, and left and right traveling motors 3e and 3f, and hydraulic actuators 3a to 3c.
f, a plurality of operating lever devices 4a to 4f provided corresponding to respective ones of the hydraulic pumps 2 and a plurality of hydraulic actuators 3a to 3f. The hydraulic actuators are controlled by operation signals of the operating levers 4a to 4f. 3a ~
A plurality of flow control valves 5a to 5f for controlling the flow rate of the pressure oil supplied to 3f; a hydraulic pump 2 and flow control valves 5a to 5f
And a relief valve 6 which opens when the pressure between the pressures exceeds a set value.

In the present embodiment, the operating levers 4a to 4f are of a hydraulic pilot type, and each of the operating levers 4a to 4f generates a pilot pressure according to the operation amount and the operating direction of the operating lever 40 by the pilot pressure of the pilot pump 43, and generates the pilot pressure. Pilot lines 44a, 44b; 45a, 45
b; 46a, 46b; 47a, 47b; 48a, 48
b; hydraulic drive units 50a, 50b; 51a, 51 of the hydraulic drive units of the corresponding flow control valves via 49a, 49b.
b; 52a, 52b; 53a, 53b; 54a, 54
b; 55a, 55b, and these flow control valves 5a to
5f is switched.

Here, as shown in FIG. 2, the hydraulic excavator includes a boom 1a and an arm 1 which rotate in a vertical direction.
b and a bucket 1c, a multi-joint type front work machine 1A, and a body 1B composed of an upper swing body 1d and a lower traveling body 1e, and a boom 1a of the front work machine 1A.
Is supported at the front part of the upper swing body 1d. The boom 1a, the arm 1b, the bucket 1c, the upper swing body 1d, and the lower traveling body 1e are respectively a boom cylinder 3a, an arm cylinder 3b, a bucket cylinder 3c, a swing motor 3
d and left and right traveling motors 3e and 3f, respectively, and their operations are instructed by the operation lever devices 4a to 4f.

The above-described hydraulic shovel is provided with the control device of the present embodiment, which is provided with a region-limited excavation control function and a composite operation correction function. The control device includes an area limit switch 7a for instructing selection of an area limit excavation control mode,
A setting switch 7b for instructing the setting of the excavation area (target excavation surface) in the area-limited excavation control mode, a composite operation correction switch 7c for instructing selection of a learning correction mode of the composite operation in the area-limited excavation control mode, and an area-limited excavation In the control mode, the operation speed indicating switch 7d for selecting and indicating two types of the maximum operation speed in the learning correction mode of the composite operation, the standard speed and the low speed, and the turning fulcrum of each of the boom 1a, the arm 1b, and the bucket 1c. Provided are angle detectors 8a, 8b, 8c for detecting respective rotation angles as state quantities relating to the position and posture of the front work machine 1A, and the primary port side is connected to the pilot pump 43, and the pilot pump 43 is connected to the pilot pump 43 in accordance with an electric signal. Proportional solenoid valve 10a for reducing and outputting the pilot pressure from the engine, and a pilot line for the operating lever device 4a for the boom. 4a is connected to the secondary port side of the proportional solenoid valve 10a and selects the high pressure side of the pilot pressure in the pilot line 44a and the control pressure output from the proportional solenoid valve 10a. A shuttle valve 12a for guiding, a proportional solenoid valve 10b installed on a pilot line 44b of an operation lever device 4a for a boom, and reducing and outputting a pilot pressure in the pilot line 44b according to an electric signal; and an operation lever for an arm. Device 4
b are respectively installed in the pilot lines 45a and 45b, and the pilot lines 45a and 45b
Proportional solenoid valve 11 that reduces and outputs pilot pressure in the chamber
a, 11b, pressure detectors 61a, 61b installed on the pilot lines 45a, 45b and detecting the pilot pressure as operation amounts of the operation lever device 4b, an area limit switch 7a, a setting switch 7b, and a composite operation correction switch 7c. , The signal from the operation speed instruction switch 7d, the detection signal of the angle detectors 8a, 8b, 8c and the pressure detector 61
a, 61b, and the proportional solenoid valves 10a, 1
0b and a control unit 9 for outputting signals to 11a and 11b.

Area limit switch 7a, setting switch 7
b, the composite operation correction switch 7c and the operation speed instruction switch 7d may be provided on the operation panel in front of the driver's seat together with other auxiliary means such as a display device, or the optional operation lever 40
May be provided on the grip.

FIG. 3 schematically shows the processing functions of the control unit 9. The control unit 9 includes an area setting operation section 9a, a front attitude operation section 9b, an arm cylinder speed operation section 9c, an arm speed vector operation section 9d, a direction conversion control correction speed vector operation section 9e, and a correction target boom cylinder speed operation section. 9f, a valve command calculation section 9g, an output section 9h, a composite operation correction calculation section 9j, an arm cylinder speed low speed command calculation section 91, and a composite operation correction calculation section 9j.
For storing the operation value (correction value) of, for example, EEPR
OM9k.

In the area setting operation section 9a, the setting switch 7
In cooperation with the front attitude calculation unit 9b in response to the instruction from b, the setting calculation of the excavation area where the tip of the bucket 1c can move is performed.
One example will be described with reference to FIG. In this embodiment, an excavation area is set in a vertical plane.

In FIG. 4, after the tip of the bucket 1c is moved to the position of the point P1 by the operator's operation, the tip position of the bucket 1c at that time is calculated by the instruction from the setting switch 7b, and then the setting switch 7b is operated. Then, a depth h1 from that position is input, and a point P1 * on the boundary of the excavation area to be set according to the depth is designated. Next, after the tip of the bucket 1c is moved to the position P2, the tip position of the bucket 1c at that time is calculated according to the instruction from the setting switch 7b, and the depth h from that position is similarly operated by operating the setting switch 7b.
2 to specify a point P2 * on the boundary of the excavation area to be set according to the depth. Then, a straight line equation connecting the two points P1 * and P2 * is calculated and used as the boundary of the excavation area.

The control unit 9 stores the dimensions of each part of the front work machine 1A and the vehicle body 1B. The control unit 9 stores these data and the rotation angles α, β detected by the angle detectors 8a, 8b, 8c. , Γ, two points P1, P2
Calculate the position of. At this time, the positions of the two points P1 and P2 are obtained, for example, as coordinate values (X1, Y1) (X2, Y2) in the XY coordinate system with the rotation fulcrum of the boom 1a as the origin. XY
The coordinate system is a rectangular coordinate system fixed to the main body 1B, and is assumed to be in a vertical plane. Coordinate values of XY coordinate system (X1, Y1)
(X2, Y2) is the rotation fulcrum of the boom 1a and the arm 1b.
If the distance between the rotation fulcrum of the arm 1b and the rotation fulcrum of the bucket 1c is L2, and the distance between the rotation fulcrum of the bucket 1c and the tip of the bucket 1c is L3,
From the rotation angles α, β, γ, it is obtained from the following equation.

X = L1 sin α + L2 sin (α + β) + L3 sin (α + β + γ) (1) Y = L1 cos α + L2 cos (α + β) + L3 cos (α + β + γ) (2) In the control unit 9, two points P1 *,
The coordinate value of P2 * is obtained by performing the following calculation of the Y coordinate, Y1 * = Y1-h1 Y2 * = Y2-h2, respectively. A linear equation connecting two points P1 * and P2 * is calculated by the following equation.

Y = (Y2 * −Y1 *) X / (X2−X1) + (X2Y1 * −X1Y2 *) / (X2−X1) (3) Further, the origin is on the straight line, and the straight line is uniaxial. , For example, an XaYa coordinate system having a point P2 * as an origin, and conversion data from the XY coordinate system to the orthogonal coordinates is obtained.

In the front attitude calculating section 9b, the dimensions of the front working machine 1A and the vehicle body 1B stored in the control unit 9 as described above, and the rotation angles α, β, detected by the angle detectors 8a, 8b, 8c, are used. Using the value of γ, the position of a predetermined portion of the front work machine 1A, such as the tip position of the bucket, is calculated as a value in the XY coordinate system.

The arm cylinder speed calculator 9c receives the pilot pressure values detected by the pressure detectors 61a and 61b, calculates the discharge flow rate _VA of the flow control valve 5b, and further calculates the speed of the arm cylinder 3b from the discharge flow rate. Calculate Va. The control unit 9 stores the relationship between the pilot pressures P _AC , P _AD and the discharge flow rate _VA of the flow control valve 5b as shown in FIG. 5, and the arm cylinder speed calculator 9c uses this relationship. The discharge flow rate _VA of the flow control valve 5b is obtained. The relationship between the pilot pressures P _AC , P _AD calculated in advance and the arm cylinder speed Va may be stored in the control unit 9, and the arm cylinder speed Va may be directly obtained from the pilot pressures P _AC , P _AD .

The arm cylinder speed calculator 9c includes an arm cylinder speed lower speed command calculator 9l. When the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed, the pressure detector 61a is used. , 61b is a predetermined value P
If it is greater than or equal to o, the pilot pressure is set to Po, the discharge flow rate _VA of the flow control valve 5b is obtained from the pilot pressure Po using the relationship shown in FIG. 5, and the speed Va of the arm cylinder 3b is calculated.

FIG. 6 is a flowchart showing details of the processing contents of the arm cylinder speed calculating section 9c and the arm cylinder speed low speed command calculating section 9l. First, in step 81,
It is determined whether the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed. If the signal indicates a low speed, the process proceeds to step 82, where the pressure detector 61
a, the pilot pressure values P _AC , P _AD detected at 61b are smaller than the predetermined P _AC , P _AD , and are equal to or higher than the pilot pressure value Po corresponding to the low speed (that is, P _AC ≧ Po, P _AD ≧ P
o) to determine the pilot pressure value P _AC ,
If P _AD is equal to or greater than the value Po, the procedure proceeds to step 83, where the pilot pressure is set to the value Po, the discharge flow rate VA of the flow control valve 5b is calculated from the pilot pressure Po using the relationship shown in FIG. Calculates the arm cylinder speed Va from the discharge flow rate VA. On the other hand, in step 81, when the signal from the operation speed instruction switch 7d does not indicate a low speed, or in step 82, the pressure detector 61a,
If the pilot pressure values P _AC , P _AD detected in 61b are less than Po, the flow control valve is obtained from the pilot pressure values P _AC , P _AD detected as usual in step 84 using the relationship shown in FIG. 5b is calculated, and the procedure 8 is further performed.
In step 5, the arm cylinder speed Va is calculated from the discharge flow rate VA. Steps 81, 82, 83, and 85 correspond to the arm cylinder speed low speed command calculation unit 91.

In the arm-based speed vector calculator 9d, the tip position of the bucket determined by the front attitude calculator 9b and the arm cylinder speed Va determined by the arm cylinder speed calculator 9c are stored in the control unit 9 in advance. The velocity vector Vc of the tip of the bucket 1c by the arm is obtained from the dimensions of each part such as L1, L2 and L3. At this time,
The velocity vector Vc is first obtained as a value in the XY coordinate system shown in FIG. 4, and then this value is converted into the XaYa coordinate system by the area setting calculation unit 9a using the conversion data to the XaYa coordinate system previously obtained. To obtain a value in the XaYa coordinate system. Here, the Xa coordinate value Vcx of the speed vector Vc in the XaYa coordinate system is a vector in a direction parallel to the boundary of the setting region of the speed vector Vc, and the Ya coordinate value Vcy is a direction perpendicular to the boundary of the setting region of the speed vector Vc. The vector component of

Direction conversion control correction speed vector calculator 9e
In the case where the tip of the bucket 1c is near the boundary of the setting area, the setting area of the velocity vector Vc of the bucket tip by the arm is set so that the tip of the bucket 1c moves along the boundary of the setting area while approaching the boundary of the setting area. Speed vector Vcy for correcting the component in the direction approaching the boundary of
a 'is calculated.

FIG. 7 is a flowchart showing an overall outline of the processing contents in the arithmetic unit 9e. First, in step 90, XaYa is calculated from the XY coordinate system previously obtained by the area setting calculation section 9a.
Using the data converted into the coordinate system, the front attitude calculation unit 9
The tip position of the bucket 1c obtained in b is converted into the XaYa coordinate system, and the distance Ya between the tip of the bucket 1c and the boundary of the setting area is obtained from the Ya coordinate value. Next, at step 91, the sign of the distance Ya is determined. Here, if the distance Ya is positive, the tip of the bucket is within the set area, so the procedure proceeds to step 92, where the processing of the direction change control within the set area is performed. Distance Ya
If the value is negative, the bucket tip has come out of the boundary of the setting area, so the procedure goes to step 93 to perform the direction change control processing outside the setting area.

FIG. 8 shows details of the process of the direction conversion control in the set area in step 92. In this processing, when the velocity vector Vc at the tip of the bucket by the arm has a component in the direction approaching the boundary of the setting area, the correction velocity vector Vcya 'for correcting the vector component to decrease as approaching the boundary of the setting area. Is calculated.

First, in step 100, the bucket 1c
The coefficient h is calculated from the distance Ya between the tip of the set and the boundary of the set area using the relationship shown in FIG. Here, the coefficient h is 1 when the distance Ya is larger than the set value Ya1, and the coefficient h is
When a becomes smaller than the set value Ya1, the value becomes smaller than 1 as the distance Ya becomes smaller, and becomes 0 when the distance Ya becomes 0, that is, when the tip of the bucket reaches the boundary of the set area.
When the distance Ya becomes smaller than 0, that is, when the tip of the bucket goes out of the set area and the distance Ya becomes a negative value, the distance Ya becomes smaller as the distance Ya decreases (as the absolute value of the distance Ya increases). It is a value that becomes smaller (the absolute value becomes larger), and such a relationship between h and Ya is stored in the storage device of the control unit 9. In this calculation, the region of Ya ≧ 0 in FIG. 8 is used.

Next, in step 101, a component perpendicular to the boundary of the set area of the velocity vector Vc, that is, Xa
The sign of the Ya coordinate value Vcy in the Ya coordinate system is determined, and Vc
If y is negative, since the bucket tip is a velocity vector in the direction approaching the boundary of the set area, the procedure proceeds to step 102, where the Ya coordinate value Vcy of the velocity vector Vc is multiplied by a coefficient h, and this value is corrected. Vertical vector component Vcya
And

When Vcy is positive, since the tip of the bucket is a velocity vector in a direction away from the boundary of the set area, the process proceeds to step 104, where the Ya coordinate value Vcy of the velocity vector Vc is obtained.
Is multiplied by a coefficient -h as a corrected vertical vector component Vcya.

Next, in step 106, Vcya '=
Vcya−Vcy is calculated, and a corrected speed vector Vcva ′ for obtaining Vcya is obtained. Here, when Vcy is negative, the corrected speed vector Vcya 'has a positive value (a speed vector in a direction in which the tip of the bucket moves away from the boundary of the set area), and when Vcy is positive, the corrected speed vector Vc
ya 'is a negative value (a velocity vector in the direction in which the bucket tip approaches the boundary of the set area).

By correcting the vector component Vcy in the vertical direction of the speed vector Vc at the tip of the bucket by the arm to Vcya using the corrected speed vector Vcya ', when the tip of the bucket 1c approaches the boundary of the set area, FIG. As shown in (a), the velocity vector Vc is corrected to Vca such that the decrease amount of the vector component Vcy in the vertical direction increases as the distance Ya decreases. As a result, the movement trajectory of the tip of the bucket by Vca becomes a curved shape that becomes parallel as approaching the boundary of the set area,
The corrected velocity vector Vca on the boundary of the set area matches the parallel component Vcx.

When the tip of the bucket 1c moves away from the boundary of the set area, as shown in FIG. 10B, as the distance Ya decreases, the negative direction of the vector component Vcy in the vertical direction decreases.
The velocity vector Vc is V so that the amount of decrease in the direction is small.
is corrected to ca, and the trajectory of the tip of the bucket by Vca also becomes a curved shape that becomes parallel as it approaches the boundary of the set area.

FIG. 11 shows the details of the processing for the direction conversion control outside the set area in step 93. This processing is for correcting the movement of the bucket tip so that when the tip of the bucket 1c goes outside the boundary of the setting area, the bucket tip returns to the setting area in relation to the distance from the boundary of the setting area. This is for calculating the corrected cylinder speed Vcya '.

First, in step 112, step 1 in FIG.
Similarly to 00, the coefficient h is calculated from the distance Ya between the tip of the bucket 1c and the boundary of the set area using the relationship shown in FIG. In this calculation, the area of Ya <0 in FIG. 8 is used.

Next, in step 113, a component perpendicular to the boundary of the setting region of the speed vector Vc at the tip of the bucket by the arm, that is, the Ya coordinate value Vc in the XaYa coordinate system
It is determined whether y is positive or negative. If Vcy is negative, since the bucket tip is a velocity vector in a direction away from the boundary of the set area, the procedure proceeds to step 114, where the above-described coefficient h and K is multiplied, and this value is set as a corrected vertical vector component Vcya. The coefficient K is an arbitrary value determined from control characteristics, and is a kind of feedback gain. Then, in step 116,
Vcya '= Vcya-Vcy is calculated, and a corrected speed vector Vcya' for obtaining Vcya is obtained.

If Vcy is positive in step 113, since the tip of the bucket is a velocity vector in the direction approaching the boundary of the set area, the flow advances to step 115 to determine the velocity vector Vc as Y.
The a-coordinate value Vcy is multiplied by the above-mentioned coefficients -h and K, and this value is set as a corrected vertical vector component Vcya. Next, in step 117, Vcya '= Vcya-Vc
y to calculate a corrected speed vector V for obtaining Vcya
cya 'is obtained. However, if Vcya '> 0, Vc
It is assumed that ya '= 0. This is because this operation is an operation for controlling the boom lowering, and the control for the boom lowering is not performed when Vcya 'is a positive value.

The vector component Vcy in the vertical direction of the speed vector Vc at the tip of the bucket by the arm is corrected to Vcya by the above corrected speed vector Vcya '.
As shown in (a) and (b), the movement trajectory of the bucket tip becomes parallel as approaching the boundary of the set area,
The speed vector Vc is corrected to Vca.

That is, when the tip of the bucket 1c is away from the boundary of the set area, as shown in FIG. 12 (a), assuming that the velocity vector Vc of the bucket tip by the arm is constant obliquely downward, The vector component Vcx in the parallel direction is constant, and the vector component Vc in the vertical direction is
cy is Vcy by Vcya ′ (= Vcya−Vcy).
a (= K · h · Vcy). As a result, the vertical component Vcy decreases as the tip of the bucket 1c approaches the set area (as the distance Ya decreases).
The movement trajectory of the bucket tip based on the corrected target speed vector Vca, which is a combination of the two, has a curved shape that becomes parallel as approaching the boundary of the setting region, and the corrected speed vector Vca on the boundary of the setting region has a parallel component. Vcx.

Also in the case where the tip of the bucket 1c approaches the boundary of the set area, as shown in FIG. 12B, the vector component Vcy in the vertical direction is Vcya '(= Vcya-
Vcy) is corrected to Vcya (= KhVcy). As a result, the vertical component Vcy decreases as the tip of the bucket 1c approaches the set area (as the distance Ya decreases). Vca
The movement locus of the bucket tip due to is a curved shape that becomes parallel as approaching the boundary of the set area.

Correction target boom cylinder speed calculator 9f
Now, the correction speed vector Vcya 'obtained by the calculation unit 9e
The correction target cylinder speed Vbr of the boom cylinder 3a for obtaining the correction speed vector Vcya 'is calculated from the data and the front end position of the bucket obtained by the front attitude calculation unit 9b. This is the inverse operation of the velocity vector calculation unit 9d by the arm except that the arm has changed to a boom.
When the correction speed vector Vcya 'is a positive value, the bucket tip is a speed vector in a direction away from the boundary of the set area, so that the correction target cylinder speed Vbr of the boom cylinder 3a is set as the target cylinder speed in the boom raising direction ( When the corrected speed vector Vcya 'is a negative value, the bucket tip is a speed vector in a direction in which the bucket tip approaches the boundary of the set area, so that the correction of the boom cylinder 3a is performed. The target cylinder speed in the boom lowering direction (the target cylinder speed in the contraction direction of the boom cylinder 3a) is calculated as the target cylinder speed for use.

In the valve command calculating section 9g, the correction target cylinder speed V of the boom cylinder 3a obtained by the calculating section 9f is obtained.
If br is in the boom raising direction, the flow control valve 5
a, the boom raising target flow rate Q _BU is obtained, and in the case of the boom lowering direction, the boom lowering target flow rate Q _BD is obtained,
Further, a command value (command current) for the proportional solenoid valves 10a and 10b is calculated from these target flow rates.

Here, the control unit 9 has command current-flow characteristics of the proportional solenoid valve 10a and the flow control valve 5a and command current-flow characteristics of the proportional solenoid valve 10b and the flow control valve 5a as shown in FIG. Boom raising command current I _BU and target flow Q _BU and boom lowering command current I _BD and target flow Q
The relationship with _BD is stored, and the valve command calculation unit 9g calculates the command current of the proportional solenoid valves 10a and 10b using this relationship.

The control unit 9 stores the relationship between the boom raising command current and the target cylinder speed and the boom lowering command current and the target cylinder speed calculated in advance, and directly outputs the command current from the target cylinder speed. You may ask. The control unit 9 stores the relationship between the target pilot pressure for boom raising and the target flow rate I _BU and the relationship between the target pilot pressure for boom lowering and the target flow rate I _BD, and stores the flow control valve 5.
a, the target pilot pressure is calculated once from the discharge flow rate (target flow rate), and the proportional solenoid valve 10a,
The command current of 10b may be calculated.

In the output section 9h, when the signal from the area limit switch 7a indicates the selection of the area limit excavation control mode, the command value calculated by the valve command calculation section 9g is amplified by an amplifier and converted into an electric signal. Proportional solenoid valves 10a, 10
b. When the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed, the pilot pressure of the arm is set to the above-mentioned predetermined value Po, and provided on the pilot lines 45a and 45b of the arm. The pilot pressure P is applied to the proportional solenoid valves 11a and 11b.
Outputs an electrical signal corresponding to o. Area limit switch 7
When the signal from a does not instruct the selection of the region limited excavation control mode, the proportional solenoid valve 10a is fully closed and an electric signal for fully opening the proportional solenoid valves 10b, 11a, 11b is output.

FIG. 14 is a flowchart showing details of the processing contents of the output unit 9h. First, in step 151, it is determined whether the signal from the area limit switch 7a indicates the area limit excavation control mode, and if the signal indicates the control mode, the process proceeds to step 152, where the operation speed instruction switch 7d outputs It is determined whether the signal indicates a low speed as the maximum operation speed. If the signal does not indicate a low speed, the process proceeds to step 153, and the command current values I _BU and I _BD calculated by the valve command calculation unit 9g are performed. _Is amplified and output as an electric signal to the proportional solenoid valves 10a and 10b, and the proportional solenoid valves 11a and 11b fully open the electric signal I _ACmax ,
_Outputs I _ADmax .

If the signal from the operation speed instruction switch 7d indicates a low speed, the flow proceeds to step 154.
The command current values I _AC and I _AD of the proportional solenoid valves 11a and 11b corresponding to the pilot pressure Po are calculated from the predetermined pilot pressure Po. In step 155, the command current values I _BU and I _BU calculated by the valve command calculation unit 9g are calculated. The _IBD is amplified and output as an electric signal to the proportional solenoid valves 10a and 10b.
The command current values I _AC and I _AD calculated in step 4 are amplified and output as electric signals to the proportional solenoid valves 11a and 11b. Thereby, the arm cylinder speed Va is calculated from the pilot pressure Po by the arm cylinder speed low speed command calculation unit 9l (FIG. 5).
83, 85), the corrected speed vector Vcya 'is determined by the direction conversion control corrected speed vector calculator 9e based on the arm cylinder speed, and the command current values I _BU , I to realize the corrected speed vector Vcya' are determined by the valve command calculator 9g. _According to the calculated _BD , the actual arm cylinder speed is changed to pilot pressure Po
Limited to the speed corresponding to.

If the signal from the area limit switch 7a does not indicate the area limit excavation control mode in step 151, the _flow advances to step 156 to output an electric signal I _BUmin for fully closing the proportional solenoid valve 10a. Proportional solenoid valve 10
b, 11a, the electric signal I _BDmax to fully open the 11b, I
_ACmax and _IADmax are output.

As described above, when the operation lever 40 of the operation lever device 4b is operated in the arm cloud direction, when the bucket tip approaches the boundary of the set area, the correction speed vector V
cya ′ is calculated as a positive value (step 102 in FIG. 8,
106), the corresponding electric signal is output to the proportional solenoid valve 10a, and the boom is moved in the upward direction.
As described in (a), the bucket tip moves so as to be parallel as approaching the boundary of the setting area, and finally moves along the boundary of the setting area. If the bucket tip goes out of the setting area beyond the boundary of the setting area,
The corrected speed vector Vcya 'is calculated as a positive value so that the tip of the bucket returns to the set area (step 11 in FIG. 11).
4, 116), the corresponding electric signal is output to the proportional solenoid valve 10a, and the boom is moved in the upward direction, and becomes parallel as the bucket tip approaches the boundary of the set area as shown in FIG. It is returned while moving. Thereby, the tip of the bucket can be moved along the boundary of the setting area.

With the bucket tip positioned near the boundary of the set area, the operating lever 40 of the operating lever device 40a is fully operated in the boom lowering direction, and at the same time, the operating lever 40 of the operating lever device 4b is arm dumped. When the bucket is operated in the direction, when the tip of the bucket moves away from the boundary of the set area, the corrected speed vector Vcya 'is calculated as a negative value (steps 104 and 106 in FIG. 8), and the corresponding electric signal is sent to the proportional solenoid valve 10b. By being output, the pilot pressure of the full operation in the boom lowering direction is reduced and output, whereby the boom is moved in the lowering direction,
As described in FIG. 10B, the tip of the bucket moves so as to be parallel as approaching the boundary of the setting area, and finally moves along the boundary of the setting area. If the bucket tip goes out of the set area beyond the boundary of the set area, the corrected speed vector Vcya 'is calculated as a positive value so as to return the bucket tip to the set area (step 115 in FIG. 11). , 117), and the corresponding electric signal is proportional solenoid valve 1
By outputting to 0a, the boom is moved in the raising direction, and as shown in FIG. 12B, is returned while moving so that the bucket tip becomes parallel as approaching the boundary of the set area. Thereby, the tip of the bucket can be moved along the boundary of the setting area.

In the latter direction conversion control by boom lowering, the operation of positioning the bucket tip near the boundary of the set area is performed by boom lowering range limit control. In this boom lowering range limit control, the operation lever device 40
When the operating lever 40a is operated in the boom lowering direction, the proportional solenoid valve 10b is opened, and when the bucket tip reaches near the boundary of the set area, the proportional solenoid valve 10b is closed to stop the boom lowering. Note that this control is not directly related to the present invention, and thus details are omitted.

In the above-described direction change control, if the signal from the operation speed instruction switch 7d does not indicate a low speed, that is, if it indicates a standard speed, the pilot generated by the operation lever device 4b is generated. The direction change control is performed based on the pressure. When the bucket tip can be moved at a speed corresponding to the operation amount of the operation lever 40 of the operation lever device 4b and the signal from the operation speed instruction switch 7d indicates a low speed, the pilot pressure Po set in advance is set. , The tip of the bucket can be moved at a speed corresponding to the pilot pressure Po regardless of the operation amount of the operation lever 40 of the operation lever device 4b. In the learning correction process of the flow characteristic, the calculation accuracy of the correction value can be improved (described later).

The combined operation correction calculation unit 9j learns the command current-flow rate characteristics of the boom raising and boom lowering shown in FIG. 13 used in the valve command calculation unit 9g in the area limited excavation control by the combined operation of the boom and the arm. Perform correction processing.

First, the concept of the learning correction processing of the present invention will be described.

In the learning correction processing of the present invention, the composite operation correction switch 7c is turned on while the signal from the area restriction switch 7a indicates selection of the area restriction excavation control mode, and the control mode is switched to the learning correction mode. This is characterized in that the control is performed while performing control (region limited excavation control) for restricting a region in which the front work machine 1A can move. The correction target is the command current-flow rate characteristic of the boom raising direction and the command current-flow rate characteristic of the boom lowering direction of the boom flow control valve 5a shown in FIG. It is also characterized in that the variation in the flow characteristics is absorbed by the correction of the boom command current-flow characteristics. Further, when performing the learning correction processing, the operation speed instruction switch 7d is appropriately switched to instruct two types of the standard operation speed and the low operation speed as the maximum operation speed, and the operation lever is fully operated to obtain the command current-flow rate characteristic. Another feature is that the calculation accuracy of the correction value is improved over a wide current range.

As shown in FIGS. 15A and 15B, the boom-up or boom-down command current-flow rate characteristics to be corrected are approximated by a plurality of straight lines, for example, four straight lines. The command current-flow rate characteristics are corrected by correcting the straight line break points m1 to m8.

For example, as shown in FIG. 15A, a straight line break point m of the command current-flow rate characteristic of the boom raising flow control valve 5a.
It is assumed that 1 to m4 are represented by (x, y) coordinates as follows.

M1 → (m1x, m1y) m2 → (m2x, m2y) m3 → (m3x, m3y) m4 → (m4x, m4v) Further, a straight line between m1 and m2, a straight line between m2 and m3, m3
The straight lines between −m4 are represented by the following equations.

Y = a1x + bl y = a2x + b2 y = a3x + b3 In the conversion from the target flow rate to the command current during the control calculation in the valve command calculation section 9g, the current value is obtained by using the above-mentioned straight line equation. The same applies to the case of boom lowering.

In order to calculate an error in the control operation due to the variation in the command current-flow rate characteristics, the target excavation plane is sandwiched between the boundary of the set area of the area limited excavation control, that is, the target excavation plane as shown in FIG. Use to set the target control range. This target control range corresponds to an allowable range of control error. In addition, a break point m1 of the straight line of the command current-flow rate characteristic
The current ranges 1 to 8 are set in accordance with .about.m8.

When the bucket tip passes below the target excavation area in the area limitation excavation control by the arm cloud and boom raising operations, the command current in the current range at that time is insufficient. For example, in the case of the current range 3 in FIG. 15A, a large current value is output for the same target flow rate by correcting the point m3 rightward or downward. In the present embodiment, m1 to m4 are corrected left and right, and m1x
The correction values for .about.m4x are dmlx to dm4x.

There are several ways to store the correction value. For example, a method of storing dm1x to dm4x as it is, or adding m1x + dm1x to m4x + dm4x to m1
There is a method of storing as x to m4x. In the former, the stored dm1x to dm4x are read out, the x-coordinate value of the break point is corrected to m1x + dm1x to m4x + dm4x, and a1, b1, a2, b2, a
By calculating 3 and b3 and calculating the linear expression of each straight line,
Correct the command current-flow rate characteristics. In the latter, the memorized m
1x to m4x are read out and directly a1, b1, a2, b
2, a3, b3 are obtained and a linear expression of each straight line is calculated to correct the command current-flow rate characteristic. The valve command calculation unit 9g uses the corrected characteristics when performing the control calculation.

FIG. 17 is a flowchart showing the entire learning correction process in the composite operation correction calculation section 9j.

First, in step 121, it is determined whether or not the control unit 9 is to be started immediately after the power is turned on. If not, the process proceeds to step 122, where the signal from the composite operation correction switch 7c is used as the composite signal. It is determined whether or not the selection of the learning correction mode of the operation is instructed. If it is instructed to select the learning correction mode, the process proceeds to step 123, where the calculation and storage processing of the correction value by the learning correction process is performed. If the selection of the learning correction mode is not instructed, the process in the calculation cycle is performed. finish. If it is determined in step 121 that the control unit 9 is at the time of startup, the process proceeds to step 124, and
The correction process of the command current-flow rate characteristic is performed using the correction value calculated and stored in step 3.

FIGS. 18 and 19 are flowcharts showing details of the correction value calculation / storage processing in step 123.

First, in step 131, a signal from the pressure detector 61a is input to determine whether or not an arm cloud operation has been instructed. If an arm cloud operation has been instructed, the flow advances to step 132 to perform learning correction for boom raising. Do the processing,
If not instructed, the signal from the pressure detector 61b is inputted in step 133 to determine whether or not the arm dump operation is instructed. If the arm dump operation is instructed, the process proceeds to step 134 to perform the boom lowering learning correction. Perform processing.

FIG. 19 is a flowchart showing details of the learning correction processing for raising and lowering the boom in steps 132 and 134.

First, it is determined in step 141 whether a predetermined time, for example, 3 seconds, has elapsed after the instruction of the arm cloud operation or the arm dump operation. This is to ensure that the bucket tip is controlled to move along the target excavation surface. In the case of an arm dumping operation in which the bucket tip moves away from the target excavation surface, as described above, the operation lever 40 of the operation lever device 4a is simultaneously fully operated in the boom lowering direction to perform the boom lowering. To be controlled to move along.

If it is determined in step 141 that the predetermined time has elapsed, the flow advances to step 142 to determine whether the tip of the bucket is below the target control range shown in FIG. If so, proceed to step 143; otherwise, proceed to step 144. In step 144, it is determined whether the tip of the bucket is above the target control range. If the tip of the bucket is above the target control range, the procedure proceeds to step 145.

In step 143, it is determined whether the command current value currently output to the proportional solenoid valve 10a or 10b falls within the range shown in FIG. 15 (a) or (b).
Increments one of the counters 1 to 8 corresponding to the command current range.

In step 145, as in step 143, it is determined whether the command current value currently output to the proportional solenoid valve 10a or 10b falls within the range shown in FIG. 15 (a) or (b). At 147, one of the counters 1 to 8 corresponding to the command current range is decremented by one.

In step 148, it is determined whether or not one control operation by one arm cloud operation or one arm dump operation has been completed.
Repeat ~ 147.

As described above, when the control calculation for learning correction is advanced, the control operation ends at a certain point. For example, when raising the boom automatically by the arm cloud operation, the boom raising operation ends when the arm passes perpendicular to the target excavation surface, and when the boom is lowered automatically by the arm dump operation Finally, the operation ends when the arm cylinder reaches the stroke end. Step 1
At 48, it is determined whether one control operation has been completed based on whether or not such a state has been attained. When one control operation is completed, the process proceeds to step 149.

In step 149, the correction values in the direction of the command current at the break points m1 to m8 are calculated according to the final values of the counters 1 to 8. For example, if the counter 1 corresponding to the point m1 is finally +10, the frequency at which the bucket tip is below the target control range is high in this command current range, and the boom must be raised a little more in this command current range. Must be done. That is, a value of + with respect to the point m1 is set as a correction value. Similarly, at points m2 to m8, a correction value of + or-is obtained according to whether the value of the counters 2 to 8 is + or-. When the counter is 0, there is no need to perform correction, so the correction value is 0. Here, if the correction value is set to an excessively large value, it is necessary to perform the correction in the opposite direction in the next learning. Therefore, it is preferable to set the correction value to a relatively small value. For example, if the command current is about 600 mA at the maximum, one correction value is corrected little by little to about 2 to 3 mA. In this case, the correction value may be constant regardless of the value of the counter, or the correction value may be changed according to the value of the counter.

Here, when a combined operation of horizontal pulling and horizontal pushing is performed by the region limited excavation control, which of the command current ranges in FIG. 15 is used depends on the operation speed. Specifically, in the case of horizontal pulling, if the operation speed is high, the current ranges 3 and 4 in FIG. 15A are mainly used for raising the boom, and if the operation speed is low, the current ranges 1 and 2 are mainly used. In the case of horizontal pressing, if the operation speed is high, the current ranges 7 and 8 in FIG. 15B are mainly used for lowering the boom, and if the operation speed is low, the current ranges 5 and 6 are mainly used.

Therefore, in order to correct the command current-flow rate characteristic in the entire current range, it is necessary to calculate the correction value in a wide range by changing the operating speed of the lever. However, the lever operation differs depending on the operator, and it is difficult for the same operator to always operate in the entire current range evenly. In the present embodiment, the operation speed is determined by an instruction from the operation speed instruction switch 7d.
When the operation lever 40 of the operation lever device 4b for the arm is fully operated by appropriately switching the operation speed instruction switch 7d, almost all the currents of the command current-flow rate characteristics are indicated. Can be operated in a range. Therefore, each break point m1 of the command current-flow rate characteristic
It is possible to easily increase the calculation accuracy of the correction value for .about.m8.

After the correction value has been obtained in this way, the procedure proceeds to step 150, and the command current-flow rate characteristic is corrected using the correction value in the above-described manner.

The same control is performed again, and the command current-flow rate characteristic is corrected little by little each time a control operation is performed, and learning is performed until the bucket tip finally falls within the target control range in the entire command current range. Perform correction processing.

When the learning correction of the command current-flow rate characteristic is completed, the correction value is finally stored in the memory 9k of the control unit 9, and when the control unit 9 starts up, the correction value is stored in the procedure 124 of the flowchart shown in FIG. It reads from the memory 9k and corrects the command current-flow rate characteristics for boom raising and boom lowering shown in FIG.

In this embodiment configured as described above, since the operation of the working device is actually controlled by the combined operation of the plurality of hydraulic actuators to obtain the correction value of the command current-control amount characteristic, the obtained correction value The operation of the working device can be controlled with high accuracy even if there is a variation in the product of the hydraulic equipment or mutual interference of the hydraulic pressure due to the combined operation of a plurality of hydraulic actuators. Further, since this correction is automatically performed during the normal control operation by turning on the composite operation correction switch 7c, it can be performed in a short time without any trouble. Further, this correction can be applied regardless of the difference in the hydraulic system whether or not pressure compensation is performed.

Further, according to the present embodiment, by performing control by switching the operation speed instruction switch 7d, the calculation accuracy of the correction value is improved over a wide current range of the command current-control amount characteristic, and the accuracy of the learning correction process is improved. Is improved.

Another embodiment of the present invention will be described with reference to FIGS. 1 and 3 according to the previous embodiment.
The same reference numerals are given to members and functions equivalent to those shown in FIG. In this embodiment, the present invention is applied to a hydraulic drive device using an electric lever type operation lever device.

In FIG. 20, reference numerals 104a to 104f denote operating lever devices of the electric lever type provided corresponding to the hydraulic actuators 3a to 3f, respectively, and operating signals (electric signals) from the operating lever devices 104a to 104f. Is input to the control unit 9A, subjected to predetermined processing, and then output as a command signal. Flow control valve 1
05a to 105f are electro-hydraulic conversion means for converting an electric signal into a pilot pressure, for example, proportional solenoid valves 150a, 150
This is an electric / hydraulic operation type valve having b to 155a and 155b at both ends, and a command signal output from the control unit 9A is input to the proportional solenoid valve.

As shown in FIG. 21, the control unit 9A has the functions of a normal operation unit 90a, a setting / control operation unit 90b, a switching output unit 90c, and an output unit 90d.

The normal operation section 90a includes the operation lever device 104
a to 104f are supplied to the proportional solenoid valves 150a, 1
The command values are converted into command values of 50b to 155a and 155b. The setting / control calculation unit 80b performs each calculation process of setting the boundary (target digging surface) of the digging region, controlling the region-limited digging, and learning correction of the compound operation described in the above embodiment (described later). The switching output unit 90c corresponds to the output unit 9h shown in FIG. 3 of the previous embodiment, and the proportional solenoid valves 150a, 150 for the boom are used.
0b and the command value of the arm proportional solenoid valves 151a, 151b may be either the command value calculated by the normal calculation unit 90a or the command value calculated by the setting / control calculation unit 90b according to the signal from the area limit switch 7a. Is selected, amplified and output (described later). The output unit 90d is the normal operation unit 9
The command value of the proportional solenoid valve other than the boom and the arm calculated at 0a is amplified and output.

FIG. 22 shows an outline of the processing functions of the setting / control calculation section 90b. The setting / control operation unit 90b includes an area setting operation unit 9a, a front attitude operation unit 9b, an arm cylinder speed operation unit 9Ac, and an arm speed vector operation unit 9
d, a direction conversion control correction speed vector calculation unit 9e, a correction target boom cylinder speed calculation unit 9f, a valve command calculation unit 9Ag, a composite operation correction calculation unit 9j, and an arm cylinder speed low speed command calculation unit 9Al. Further, it has a memory for storing the operation value (correction value) of the composite operation correction operation section 9j, for example, an EEPROM 9k.

The processing functions of the area setting calculation section 9a and the front attitude calculation section 9b are the same as those shown in FIG. 3 according to the previous embodiment.

The arm cylinder speed calculator 9Ac receives an arm operation signal (electric signal) S _A from the arm operation lever device 104b and outputs the operation signal S _{A from} the level range of the operation signal S _A. after classifying the one of the operation signal S _AD operation signal S _AC and arm dumping of the cloud, the same operation signal S _AC to that shown in FIG. 5 stored in the control unit 9A, the S _AD and flow control valve 105b the relationship between the discharge flow rate V _a, determine the discharge flow rate V _a of the flow control valve 105b corresponding to the operation signal S _AC or S _AD, further target speed of the arm cylinder 3b from the discharge flow rate (hereinafter, referred to as the target arm cylinder speed ) Calculate Var. The control unit 9A of the operation signal S _AC, stores the relationship between the S _AD and the target arm cylinder speed Var, operation signals S _AC,
It may be obtained directly target arm cylinder speed Var from S _AD.

The arm cylinder speed calculator 9Ac includes an arm cylinder speed lower speed command calculator 9Al. When the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed, the operation signal S _AC instead of the S _AD, using the value So of low speed corresponding operation signal previously determined, calculates target arm cylinder speed Var from this value So.

FIG. 23 shows an arm cylinder speed calculator 9Ac.
The details of the processing content of the arm cylinder speed low speed command calculation unit 9Al are shown in a flowchart. First, in step 87, the operation signal S _A is converted into the arm cloud operation signal S _AC and the arm dump operation signal S _AD according to the level range _.
Then, in step 81, it is determined whether or not the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed. If the signal indicates a low speed, the process proceeds to step 83. Calculates the discharge flow rate VA of the flow control valve 105b from the predetermined operation signal value So corresponding to the low speed, and further calculates the discharge flow rate VA in step 85A.
From the target arm cylinder speed Var. on the other hand,
In step 81, if the signal from the operation speed instruction switch 7d does not indicate a low speed, the discharge flow rate VA of the flow control valve 105b is calculated from the operation signals S _AC and S _AD detected as usual in step 84A. In step 85A, the target arm cylinder speed Var is calculated from the discharge flow rate VA. Steps 81, 83, and 85A correspond to the arm cylinder speed low speed command calculation unit 91.

In the example shown in FIG. 23, when the signal from the operation speed instruction switch 7d indicates a low speed as the maximum operation speed, regardless of the operation signals S _AC and S _AD. Although the predetermined value So of the operation signal corresponding to the low speed is used, similar to the previous embodiment shown in FIG.
Only when the operation signals S _AC and S _AD exceed So, the value So of the operation signal corresponding to the low speed may be used.

The processing contents of the arm-based speed vector calculation unit 9d, the direction conversion control correction speed vector calculation unit 9e, and the correction target boom cylinder speed calculation unit 9f are the same as the calculation units 9d, 9e, Same as 9f. However, the velocity vector calculating section 9d for the arm calculates the velocity vector Vc at the tip of the bucket 1c from the target arm cylinder velocity Var instead of the arm cylinder velocity Va.

In the valve command calculation section 9Ag, the calculation section 9f
From the correction target cylinder speed Vbr of the boom cylinder 3a obtained in the above, the command current I of the proportional solenoid valves 150a and 150b is obtained.
_BU, computes the I _BD, and the proportional solenoid valve from the target cylinder speed Var of the arm cylinder 3b obtained in the calculating portion 9ac 1
Calculate the command currents I _AC and I _AD for 51a and 151b.

FIG. 24 shows the details of the processing contents of the valve command calculating section 9Ag. First, in step 171, obtains a target flow rate Q _BU boom-up of the flow control valve 105a if the correction target cylinder speed Vbr of the boom cylinder 3a is of boom-up direction, when those of boom-down direction Obtain the target flow _QBD for boom lowering, and
In these, the proportional solenoid valves 150a, 150a,
The command currents I _BU and I _BD of 150b are calculated.

The control unit 9A shown in FIG. 13 shows command current-flow characteristics of the proportional solenoid valve 150a and the flow control valve 105a and command current-flow characteristics of the proportional solenoid valve 150b and the flow control valve 105a. The relationship between the boom raising command current I _BU and the target flow rate Q _BU and the boom lowering command current I _BD and the target flow rate Q _BD are stored, and in step 172, the proportional solenoid valves 150a, 150a, 1
The command currents I _BU and I _BD of the 50b are calculated.

Next, in step 173, when the target cylinder speed Var of the arm cylinder 3b is in the arm cloud direction, the target flow rate Q _AC of the arm cloud of the flow control valve 105b is obtained, and the target flow rate is in the arm dump direction. obtains a target flow rate Q _AD of the arms dump in the case, step 17
4, the proportional solenoid valve 151 is calculated from these target flow rates.
a, 151b of the command current I _AC, computes the I _AD. In this case as well, the control unit 9A includes the command current I _AC and the target flow rate Q as command current-flow characteristics of the proportional solenoid valve 151a and the flow control valve 105b and command current-flow characteristics of the proportional solenoid valve 151b and the flow control valve 105b. The relationship between the _AC and the command current I _AD and the target flow rate Q _AD is stored, and the procedure 174 calculates the command currents I _AC and I _AD using this relationship.

The control unit 9 stores the relationship between the command current and the target cylinder speed for the boom raising, boom lowering, arm cloud, and arm dump, respectively.
The command current may be obtained directly from the target cylinder speed. The control unit 9 stores the relationship between the target pilot pressure and the target flow rate for the boom raising, the boom lowering, the arm cloud, and the arm dump, and temporarily sets the target pilot pressure from the discharge flow rate (the target flow rate) of the flow control valve. Then, the command current of the proportional solenoid valve may be calculated from the target pilot pressure.

The combined operation correction calculation unit 9j uses the same boom raising and boom lowering command currents as shown in FIG. 13 and is used by the valve command calculating unit 9Ag in the area limited excavation control by the combined operation of the boom and the arm. -Perform learning correction processing of flow characteristics. The processing contents of the operation unit 9j are the same as those of the operation unit 9j of FIG. 3 according to the above embodiment.

FIG. 25 shows details of the processing contents of the switching output unit 90c. First, in step 181, it is determined whether or not the signal from the area limit switch 7a instructs selection of the area limited excavation control mode. If not, the procedure proceeds to step 182 and the boom The normal operation unit 90 generates command values for the proportional solenoid valves 150a and 150b for the arm and the proportional solenoid valves 151a and 151b for the arm.
If the command currents I _BU , I _BD , I _AC , and I _AD calculated in step a are selected, amplified and output, and the instruction to select the region-limited excavation control mode is given, the process proceeds to step 183 and the boom Currents I _BU , I _BD , I _AC , I _AD calculated by the setting / control calculation unit 90b as command values of the proportional solenoid valves 150a, 150b for the arm and the proportional solenoid valves 151a, 151b for the arm _.
And amplifies and outputs this.

According to the present embodiment having the above-described configuration, in the hydraulic drive device using the operating lever device of the electric lever type, when the area-limited excavation control is performed by the combined operation of the boom and the arm, each product of the hydraulic device is controlled. Regardless of the above-described variation and mutual interference of hydraulic pressure, the same effect as in the previous embodiment can be obtained, such as that the command current-flow rate characteristic can be appropriately corrected and the operation of the front work machine 1A can be accurately controlled.

In particular, also in this embodiment, the arm cylinder speed calculating section 9c is provided with the arm cylinder speed low speed command calculating section 9l, and the signal from the operating speed instruction switch 7d indicates the low operating speed as the maximum operating speed. Sets the target arm cylinder speed to a low speed and performs the direction change control based on the low target arm cylinder speed. Therefore, the operation speed instruction switch 7d is appropriately switched to operate the operation lever of the operation lever device 104b for the arm. Can be operated in almost the entire current range of the command current-flow characteristic, and the calculation accuracy of the correction value for each break point m1 to m8 of the command current-flow characteristic shown in FIG. This makes it possible to increase the accuracy of the learning correction process.

Note that the present invention is not limited to the above embodiment, and various modifications are possible. For example, in the above embodiment, an angle detector is used as a means for detecting a state quantity related to the position and posture of the front work machine 1A, but a stroke gauge for detecting a stroke of a cylinder may be used.

Although the command current-flow rate characteristic is approximated by four straight lines, it may be approximated by more or less straight lines. Further, the correction value is determined based on whether the counter is + or-. However, a dead zone may be provided in the counter value, and the correction value may be determined when the counter value is a certain value or more.

In the above-described embodiment, the correction value is stored in the memory 9k in the learning correction mode, and the command current-control amount characteristic is corrected using the correction value in the control mode. Command current-
The control amount characteristic is corrected, and the corrected command current −
The control amount characteristic may be stored in the memory 9k, and the corrected command current-control amount characteristic may be used in the control mode.

Further, in the above embodiment, the instruction speed by the operation speed instruction switch 7d is two types, but there may be more types of speeds.

In the above embodiment, the command current-flow rate characteristic is corrected. However, when the valve command calculation sections 9g and 9Ag use the command current-actuator speed characteristic instead of the command current-flow rate characteristic, the command current-actuator speed characteristic is used. Other characteristics such as speed characteristics may be corrected.

Further, in the above embodiment, the present invention is applied to a hydraulic excavator that performs region-limited excavation control. However, the present invention may be applied to a hydraulic excavator that performs trajectory control or other control.

[0119]

According to the present invention, since the operation of the working device is actually controlled by the combined operation of a plurality of hydraulic actuators to obtain the correction value of the command current-control amount characteristic, the accuracy of the obtained correction value is high. The operation of the working device can be controlled with high accuracy even when there is high product-to-product variation of hydraulic equipment and mutual interference of hydraulic pressure due to combined operation of a plurality of hydraulic actuators. In addition, since this correction is automatically performed during a normal control operation, it can be performed in a short time without any trouble. Further, this correction can be applied irrespective of the difference in the hydraulic system whether or not pressure is compensated, and is excellent in versatility.

When the correction value of the command current-control amount characteristic is obtained, the correction value can be obtained by appropriately switching the speed control means. Therefore, the calculation accuracy of the correction value can be obtained over a wide current range of the command current-control amount characteristic. Is improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a control device of a hydraulic working machine according to an embodiment of the present invention, together with a hydraulic drive device thereof.

FIG. 2 is a diagram showing the appearance of a hydraulic shovel to which the present invention is applied and the shape of a setting area around the hydraulic shovel.

FIG. 3 is a block diagram illustrating a control function of a control unit.

FIG. 4 is a diagram illustrating a method of setting a coordinate system and an area used in the area limited excavation of the embodiment.

FIG. 5 is a diagram showing a relationship between a pilot pressure and a discharge flow rate of a flow control valve for an arm.

FIG. 6 is a flowchart showing the entire processing contents in an arm cylinder speed calculation unit and an arm cylinder speed low speed command calculation unit.

FIG. 7 is a flowchart showing the entire processing content in a direction conversion control correction speed vector calculation unit.

FIG. 8 is a flowchart showing a process of a direction conversion control calculation in a set area in a direction conversion control correction speed vector calculation unit.

FIG. 9 is a diagram illustrating a relationship between a distance Ya between a bucket tip and a boundary of a setting area and a coefficient h in a direction conversion control calculation.

10A and 10B are diagrams illustrating an example of a trajectory when a bucket tip is controlled to change direction in a set area. FIG. 10A illustrates a case where the bucket tip approaches a boundary of the set area, and FIG. Is away from the boundary of.

FIG. 11 is a flowchart showing the processing contents of a direction conversion control calculation outside a set area in a direction conversion control correction speed vector calculation unit.

12A and 12B are diagrams illustrating an example of a trajectory when the direction of the bucket tip is controlled to change direction within the set area. FIG. 12A illustrates a case where the bucket tip is separated from the boundary of the set area, and FIG. In this case.

FIG. 13 shows a relationship between a target flow rate for boom raising and a command current,
FIG. 4 is a diagram illustrating a relationship between a target flow rate for boom lowering and a command current.

FIG. 14 is a flowchart illustrating the entire processing content in an output unit.

FIG. 15 is a diagram illustrating a concept of correcting a command current-flow rate characteristic.

FIG. 16 is a diagram showing a target control range used for obtaining a correction value of a command current-flow rate characteristic.

FIG. 17 is a flowchart illustrating the entire processing content of a learning correction process in a composite operation correction calculation unit.

FIG. 18 is a flowchart illustrating a learning mode process.

FIG. 19 is a flowchart illustrating details of a boom-up / boom-down learning correction process in the learning mode process.

FIG. 20 is a view similar to FIG. 1, showing a control device for a hydraulic working machine according to another embodiment of the present invention.

FIG. 21 is a block diagram illustrating a control function of a control unit.

FIG. 22 is a block diagram illustrating processing functions of a setting / control calculation unit of the control unit.

FIG. 23 is a flowchart showing the processing contents of an arm cylinder speed calculator and an arm cylinder speed lower speed command calculator.

FIG. 24 is a flowchart showing the processing contents of a valve command calculation unit.

FIG. 25 is a flowchart showing processing contents of a switching output unit.

[Explanation of symbols]

 Reference Signs List 1A Front work machine 1B Body 1a Boom 1b Arm 1c Bucket 1d Upper swing body 1e Lower traveling body 2 Hydraulic pump 3a to 3f Hydraulic actuator 4a to 4f Operating lever device 5a to 5f Flow control valve 6 Relief valve 7a Area limit switch 7b Setting switch 7c Composite operation correction switch 7d Operation speed instruction switch 8a, 8b, 8c Angle detector 9 Control unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomita ▲ Sada ▼ Hisa Tsuchiura-machi, Tsuchiura-shi, Ibaraki Pref.

Claims (4)

[Claims] A method of calculating a command current value from a target value of a control amount in accordance with a preset command current-control amount characteristic, and switching a flow control valve by using the command current value to drive a hydraulic actuator. A composite operation correction instruction unit, a composite operation maximum speed instruction unit, and the composite operation correction unit. In accordance with a command from the instruction means, an error in the control operation of the working device is calculated from position information when controlling the operation of the working device by performing a combined operation of the plurality of hydraulic actuators, and based on the error, the command current- Correction value calculation means for obtaining a correction value of the control amount characteristic; and characteristic correction means for correcting the command current-control amount characteristic using the correction value; When the correction value is calculated by the correction value calculating means, a speed control means for controlling a composite operation speed of the plurality of hydraulic actuators so as not to exceed a maximum speed instructed by the composite operation maximum speed instruction means is provided. Control device for hydraulic working machine. 2. A method of calculating a command current value from a target value of a control amount in accordance with a preset command current-control amount characteristic, and switching a flow control valve by using the command current value to drive a hydraulic actuator. A hydraulic operating machine control device that controls the operation of the working device by performing a composite operation of a plurality of hydraulic actuators including the hydraulic actuator, wherein: a composite operation correction instruction unit; a composite operation speed instruction unit; In accordance with a command from the means, an error in the control operation of the working device is calculated from position information when controlling the operation of the working device by operating the plurality of hydraulic actuators in combination, and based on the error, the command current-control is calculated. Correction value calculating means for obtaining a correction value of the amount characteristic; characteristic correcting means for correcting the command current-control amount characteristic using the correction value; A hydraulic control unit for controlling a composite operation speed of the plurality of hydraulic actuators so as to obtain an operation speed instructed by the composite operation speed instruction unit when a correction value is obtained by the positive value calculation unit. Work machine control device. 3. The control device for a hydraulic working machine according to claim 1, wherein said correction value calculating means controls the operation of said working device by operating said plurality of hydraulic actuators in combination. Is compared with the target control range, and whether the current position is outside the target control range,
First calculating means for calculating which side is outside the target control range; and second calculating means for calculating a correction value of the command current-control amount characteristic based on the calculation result of the first calculating means. A control device for a hydraulic work machine, comprising: 4. The control device for a hydraulic work machine according to claim 3, wherein said work device includes a boom and an arm which constitute an articulated front work machine of a construction machine, and
The calculating means performs the calculation by comparing the current position of the working device and the target control range when controlling the operation of the working device by a combined operation by boom raising / arm cloud or boom lowering / arm dumping, The second operation means calculates a correction value of the command current-flow rate characteristic of the boom flow control valve in the boom raising direction or the boom lowering direction as the command current-control amount characteristic. apparatus.