JPH11350537A - 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 5a for the boom, and the irregularity of the instruction current and flow-rate characteristics of a flow control valve 5b for the arm absorbed by the specific correction of the boom. In addition, the control coefficient K of the area limit excavation control is modified from K1 to smaller K2 in the learning correction mode.

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.
Further, a control value, for example, a target value of a flow rate is calculated by a control operation using a control coefficient, and a command current value is calculated from a target value of the control amount (flow rate) according to a preset input / output characteristic, for example, a command current-flow rate characteristic. Is calculated, and the flow control valve is switched by the proportional solenoid valve using the value of the command current.

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. Hydraulics that are effective under the condition that they are not interfered with by the operation of the actuator, that is, a machine having a hydraulic system with a flow control valve with pressure compensation, but in which 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, the present invention calculates a target value of a control amount by a control operation using a control coefficient, and sets a preset command current-control amount characteristic. Calculates the value of the command current from the target value of the control amount according to the following formula, switches the flow control valve using the value of the command current to drive the hydraulic actuator, thereby combining a plurality of hydraulic actuators including the hydraulic actuator. In a control device for a hydraulic work machine that controls the operation of a working device by operating, a composite operation correction instructing means, and a command from the composite operation correction instructing device, performs a combined operation of the plurality of hydraulic actuators to operate the working device. Of the control operation of the working device from position information at the time of controlling the control, and based on this error, a correction value for obtaining a correction value of the command current-control amount characteristic is calculated. Value calculating means, the command current using the correction value - and characteristic correction means for correcting the control quantity characteristics,
A control coefficient correcting means for changing a control coefficient used in the control calculation when there is a command from the composite operation correction instructing means.

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.

Further, when there is a command from the composite operation correction instructing means in the control coefficient correcting means, the control coefficient used in the control calculation is changed, so that the operation of the working device is controlled and the correction value is calculated by the correction value calculating means. When calculating, the error in the control operation of the working device due to the variation in the characteristics of the device becomes remarkable, and the calculation accuracy of the correction value is improved.

(2) In the above (1), preferably,
The control coefficient correction unit changes a control coefficient used in the control calculation to a value smaller than that in a normal control.

Accordingly, when the correction value is calculated by the correction value calculating means while controlling the operation of the work device, errors in the control operation of the work device due to variations in the characteristics of the equipment become remarkable, and the calculation accuracy of the correction value is reduced. improves.

(3) In the above (1), preferably, the correction value calculating means is configured to control the operation of the working device by operating the plurality of hydraulic actuators in a combined manner. And the target control range,
First computing means for computing whether the current position is outside the target control range and on which side outside the target control range, the command current-control amount based on the computation result of the first computing means Second calculating means for calculating a correction value of the characteristic.

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. The correction value of the command current-flow rate characteristic in the direction or the boom lowering direction is calculated. Thereby, the 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 dumping is obtained.

[0017]

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 corresponding to the operation amount and the operating direction of the operating lever 40 by the pilot pressure of the pilot pump 43, and this pilot pressure is generated. 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 has a boom 1a and an arm 1 which rotate vertically.
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 control device according to the present embodiment is provided with the above-described hydraulic shovel having 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 the learning correction mode of the composite operation in the area limited excavation control mode, and a boom 1a; Angle detectors 8a, 8b, 8c provided at respective pivot points of the arm 1b and the bucket 1c and detecting respective pivot angles as state quantities relating to the position and posture of the front work machine 1A;
The primary port side is connected to the pilot pump 43, the proportional solenoid valve 10a for reducing and outputting the pilot pressure from the pilot pump 43 according to the electric signal, and the pilot line 44a and the proportional solenoid valve 10a of the operating lever device 4a for the boom. Connected to secondary port side, pilot line 4
A shuttle valve 12a for selecting a high pressure side of the pilot pressure in the valve 4a and the control pressure output from the proportional solenoid valve 10a and leading it to the hydraulic drive unit 50a of the flow control valve 5a, and a pilot line 44b of the operating lever device 4a for the boom. And a proportional solenoid valve 10b for reducing and outputting a pilot pressure in a pilot line 44b in accordance with an electric signal, and pilot lines 45a and 45b of an operating lever device 4b for an arm.
And proportional solenoid valves 11a and 11b for reducing and outputting the pilot pressure in the pilot lines 45a and 45b in accordance with the electric signals.
a, 45b, and pressure detectors 61a, 61b for detecting the pilot pressure of the operation lever device 4b as an operation amount of the operation lever device 4b.
1b, signals from the area limit switch 7a, the setting switch 7b, the composite operation correction switch 7c and the angle detector 8
a, 8b, 8c and pressure detectors 61a, 61
and a control unit 9 for inputting the detection signal of b and outputting signals to the proportional solenoid valves 10a, 10b and 11a, 11b.

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

FIG. 3 shows an outline of 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 memory for storing the calculated values (correction values) of the composite operation correction operation unit 9j, each having the functions of a valve command operation unit 9g, an output unit 9h, a composite operation correction operation unit 9j, and a feedback gain correction operation unit 9l. , For example, EEPRO
M9k.

In the area setting calculation 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) Furthermore, the origin is set on the straight line and the straight line is defined as one axis. , 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 each part of the front work 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 inputs the pilot pressure values detected by the pressure detectors 61a and 61b, obtains 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-based speed vector calculator 9d calculates the position of the bucket tip calculated by the front attitude calculator 9b, the arm cylinder speed calculated by the arm cylinder speed calculator 9c, and the L value stored in the control unit 9.
The velocity vector Vc of the tip of the bucket 1c by the arm is obtained from the dimensions of each part such as 1, L2, L3, and the like. At this time, the velocity vector Vc is first obtained as a value of the XY coordinate system shown in FIG. 4, and then this value is converted to the XaYa coordinate system using the conversion data to the XaYa coordinate system previously obtained by the area setting calculation unit 9a. By conversion, it is obtained as a value in the XaYa coordinate system. Here, X of the velocity vector Vc in the XaYa coordinate system
The a-coordinate value Vcx 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 vector component in a direction perpendicular to the boundary of the setting region of the speed vector Vc.

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. The calculation unit 9e includes a feedback gain correction calculation unit 91, and changes the control coefficient K, which is the feedback gain, from K1 to K2 (<K1) during the calculation process in the out-of-set-region conversion control when the learning correction mode is selected ( See below).

FIG. 6 is a flowchart showing an overall outline of the processing contents in the arithmetic section 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. 7 shows the 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

If Vcy is positive, since the bucket tip is a velocity vector in the direction away from the boundary of the set area, the procedure 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).

When the vertical vector component Vcy of the speed vector Vc at the tip of the bucket by the arm is corrected to Vcya by the above-described corrected speed vector Vcya ', when the tip of the bucket 1c approaches the boundary of the set area, FIG. As shown in (a), the speed vector Vc is corrected to Vca such that the decrease amount of the vertical vector component Vcy 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 setting area matches the vector component Vcx in the parallel direction.

When the tip of the bucket 1c moves away from the boundary of the set area, as shown in FIG. 9B, as the distance Ya decreases, the amount of decrease in the negative direction of the vector component Vcy in the vertical direction decreases. The velocity vector Vc is Vc
is corrected to a, and the trajectory of the bucket tip by Vca also becomes a curved shape that becomes parallel as approaching the boundary of the set area.

FIG. 10 shows the details of the process of the outside conversion of 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 110, it is determined whether or not a composite operation correction instruction is currently issued based on whether or not a signal from the composite operation correction switch 7c indicates selection of a learning correction mode for composite operation. If the instruction for composite operation correction has not been issued, the process proceeds to step 111a. The control coefficient (feedback gain) K used in steps 114 and 115 described below is set to K1, and if the instruction for composite operation correction has been issued, the process proceeds to step 111b. , Control coefficient K
Is K2. Here, K2 is smaller than K1 and K2
1 and K2 are both "1" or more. Also, the control coefficient K
1 is an arbitrary value determined from control characteristics, and the control coefficient K2 is an arbitrary value suitable for improving the accuracy of learning correction processing (described later).

The processing of steps 110, 111a, and 111b is performed by the feedback gain correction calculator 91 included in the calculator 9e.

Next, in step 112, step 10 in FIG.
Similarly to 0, 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, the component perpendicular to the boundary of the setting area of the velocity 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. Next, in step 116, Vcya '= Vcya-Vcy is calculated, and a correction speed vector Vcya' for obtaining Vcya is calculated.
Ask for.

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 process proceeds to step 115, where Y of the velocity vector Vc is determined.
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.

Here, the value of K ·
h · Vcy or K · (−h) · Vcy becomes a velocity vector heading toward the boundary of the set area, which decreases as the absolute value of the distance Ya decreases. That is, it can be said that the control coefficient K is a kind of feedback gain.

The vertical vector component Vcy 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 ', and FIG.
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. 11 (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.

In the case where the tip of the bucket 1c approaches the boundary of the set area, as shown in FIG. 11B, 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.

The composite operation correction switch 7c is turned on.
When the composite operation correction instruction is given, the control coefficient K is set to a value K2 smaller than the normal coefficient K1, so that the value of the corrected vertical vector component Vcya becomes small, and the bucket tip becomes the set area. It is difficult to return to the boundary of.
For this reason, the command current −
In the flow rate characteristic learning correction process, a control operation error serving as a learning parameter becomes remarkable, and the calculation accuracy of the correction value can be increased (described later).

Correction target boom cylinder speed calculator 9f
Now, the correction speed vector Vcya 'obtained by the calculation unit 9e
The correction target cylinder speed of the boom cylinder 3a for obtaining the correction speed vector Vcya 'is calculated from the data and the tip 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. Also,
When the corrected speed vector Vcya 'is a positive value, the bucket vector is a speed vector in a direction in which the bucket tip moves away from the boundary of the set area. Therefore, the target cylinder speed for the boom raising direction (boom cylinder 3a) The target cylinder speed in the extension direction of the boom cylinder 3a is calculated, and when the corrected speed vector Vcya 'is a negative value, it is a speed vector in a direction in which the tip of the bucket approaches the boundary of the set area. The target cylinder speed in the boom lowering direction (the target cylinder speed in the contracting direction of the boom cylinder 3a) is calculated as the speed.

When the correction target cylinder speed of the boom cylinder 3a obtained by the calculation unit 9f is in the boom raising direction, the valve command calculation unit 9g obtains the boom raising target flow rate of the flow control valve 5a, and lowers the boom. In the case of the direction, the target flow rate for boom lowering is obtained, and the 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. Further, in order to accurately perform the above-described direction change control, it is preferable that the moving speed of the arm cloud or the arm dump itself is reduced as the bucket tip approaches the boundary of the excavation area. (For example, deceleration processing of a lever signal) (for example, Japanese Patent Laid-Open No. 9-5325).
No. 9). When the control device of this embodiment has such a deceleration processing function, the output unit 9h further outputs an electric signal for deceleration processing to the proportional solenoid valves 11a and 11b provided on the pilot lines 45a and 45b of the arms. I do. If the signal from the area restriction switch 7a does not indicate selection of the area restriction excavation control mode, the proportional solenoid valve 1
0a is fully closed, and an electric signal for fully opening the proportional solenoid valves 10b, 11a, 11b is output.

As described above, when the operating lever 40 of the operating lever device 4b is operated in the arm cloud direction, when the tip of the bucket approaches the boundary of the set area, the correction speed vector V
cya ′ is calculated as a positive value (step 102 in FIG. 7,
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 correction speed vector Vcya ′ is calculated as a positive value so that the bucket tip returns to the set area (step 11 in FIG. 10).
4, 116), the corresponding electric signal is output to the proportional solenoid valve 10a, and the boom is moved in the upward direction, and as shown in FIG. 11A, the bucket tip becomes parallel as it approaches the boundary of the set area. It is returned while moving. Thereby, the tip of the bucket can be moved along the boundary of the setting area.

With the tip of the bucket 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. 7), 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. 9B, 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. 10). , 117), and the corresponding electrical signal is proportional solenoid valve 10
The boom is moved in the raising direction by being output to a, and is returned while moving so that the tip of the bucket becomes parallel as it approaches the boundary of the set area, as shown in FIG. Thereby, the tip of the bucket can be moved along the boundary of the setting area.

In the latter direction change control by boom lowering, the operation of positioning the bucket tip near the boundary of the set area is performed by boom lowering range limiting 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.

The combined operation correction calculating section 9j learns the command current-flow rate characteristics of the boom raising and boom lowering shown in FIG. 12 used in the valve command calculating section 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 process of the present invention, the control mode is switched to the learning correction mode by turning on the composite operation correction switch 7c while the signal from the area restriction switch 7a indicates the selection of the area restriction excavation control 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, in the learning correction mode, the control coefficient K used in the direction conversion control outside the set area is changed from K1 to a small value of K2, the correction speed vector Vcya during the area limit control is reduced, and the bucket tip returns to the set area. It is also characterized in that the speed is reduced, the error of the control operation due to the variation in the command current-flow rate characteristic becomes remarkable, and the correction accuracy is improved.

As shown in FIGS. 13A and 13B, the boom-up or boom-down command current-flow rate characteristics to be corrected are approximated by a plurality of 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, a straight line break point m of the command current-flow rate characteristic of the flow control valve 5a for raising the boom shown in FIG.
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, m4y) 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 + bly = 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 linear equation. The same applies to the case of boom lowering.

In order to calculate the error of the control operation due to the variation in the command current-flow rate characteristic, the target excavation surface is sandwiched as shown in FIG. Use to set the target control range. This target control range corresponds to an allowable range of control error. Further, the break points m1 to m8 of the straight line of the command current-flow rate characteristic
The current ranges 1 to 8 are set in accordance with.

When the tip of the bucket passes under the target excavation area in the area excavation control by the arm cloud and the boom raising operation, the command current in the current range at that time is insufficient. For example, in the case of the current range 3 in FIG. 13A, a large current value is output for the same target flow rate by correcting the point m3 to the right 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 values. 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. 15 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 power is turned on immediately after the control unit 9 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. 16 and 17 are flowcharts showing details of the correction value calculation / storage process in step 123.

First, in step 131, a signal is input from the pressure detector 61a to determine whether or not an arm cloud operation is instructed. If an arm cloud operation is 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. 17 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 or not 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. 13A or 13B.
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 is within the range shown in FIG. 13 (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, a correction value in the command current direction at the above-mentioned break points m1 to m8 is 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, in the control operation in the learning correction mode, the control coefficient K used in the direction conversion control outside the set area is K1 in the direction conversion control correction speed vector calculation section 9e.
To K2 (<K1) (step 1 in FIG. 10).
11b) When the boom raising is automatically performed by the arm cloud operation, the vertical vector component Vcya corrected by the boom raising (procedure 11 in FIG. 10).
When the boom lowering is automatically performed by the arm dump operation, the vertical vector component Vcy corrected by the boom lowering is used.
a (the value calculated in the procedure 115 in FIG. 10) becomes smaller. That is, it becomes difficult for the bucket tip to return to the boundary of the set area. Therefore, the error of the control operation due to the variation of the command current-flow rate characteristic becomes remarkable, and the frequency at which the bucket tip is located within the target control range shown in FIG. 14 decreases, that is, the bucket tip is below the target control range. The frequency increases, and as a result, the number of additions in the counters 1 to 8 in step 146 increases, and the accuracy of calculating the correction value obtained from the values of the counters 1 to 8 in step 149 improves.

After the correction value has been obtained in this way, the process 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. Make corrections.

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 constructed as described above, the operation value of the command current-control amount characteristic is obtained by actually controlling the operation of the working device by the combined operation of a plurality of hydraulic actuators. 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.

According to the present embodiment, when the correction value of the command current-control amount characteristic is obtained, the control coefficient K is set to the normal value K
Since the value is changed to a value K2 smaller than 1, the toe of the bucket hardly returns to the set area, the error due to the variation in the command current-flow rate characteristic becomes remarkable, and the correction accuracy 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 having a trajectory control function using an electric lever type operation lever device.

In FIG. 18, reference numerals 104a to 104f denote electric lever type operation lever devices provided corresponding to the hydraulic actuators 3a to 3f, respectively, and operation signals (electric signals) from these operation 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.

Reference numeral 7Aa denotes a trajectory control switch for instructing start / end of trajectory control. When the start of trajectory control is instructed, it is possible to instruct whether to select horizontal pull or horizontal push. . 7Ab is a setting switch for instructing the setting of the target excavation locus of the locus control, and 7c is a setting switch.
Is a composite operation correction switch for instructing selection of a learning correction mode for composite operation, as in the previous embodiment.

As shown in FIG. 19, the control unit 9A has the functions of a normal operation section 90a, a setting / control operation section 90b, a switching output section 90c, and an output section 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 sets a target excavation trajectory, trajectory control,
Each arithmetic processing for learning correction of the composite operation is performed (described later). The switching output unit 90c is the output unit 9h shown in FIG.
When the signal from the trajectory control switch 7Aa does not indicate selection of the trajectory control mode,
The command value calculated by the normal operation unit 90a is selected as the command value of the proportional solenoid valves 150a and 150b for the boom and the proportional solenoid valves 151a and 151b for the arm, and the command value is amplified and output to select the trajectory control mode. If so,
Set as command values for the boom proportional solenoid valves 150a, 150b and the arm proportional solenoid valves 151a, 151b.
The command value calculated by the control calculation unit 90b is selected, amplified and output. The output unit 90d amplifies and outputs the command value of the proportional solenoid valve other than the boom and the arm calculated by the normal operation unit 90a.

FIG. 20 shows an outline of the processing functions of the setting / control calculation section 90b. The setting / control calculation unit 90b includes a target excavation locus setting unit 90f and an excavation locus control unit 90g. The setting unit 90f includes a target excavation locus setting calculation unit 9Aa. The control unit 90g includes a front posture calculation unit 9b and a target Speed vector calculator 9n, target boom angular speed calculator 9p, target arm angular speed calculator 9q, target boom cylinder speed calculator 9r, target arm cylinder speed calculator 9s, feedback control amount calculator 9t, valve command calculator 9g, composite A memory having the functions of the operation correction operation unit 9Aj and the feedback gain correction operation unit 9l and storing the operation value (correction value) of the composite operation correction operation unit 9j, for example, an EEPROM
9k.

The target excavation trajectory setting calculating section 9Aa cooperates with the front attitude calculating section 9b in response to an instruction from the setting switch 7Ab to perform a setting operation of the target excavation trajectory in which the tip of the bucket 1c moves. The calculation of the target excavation trajectory is the same as the calculation of setting the excavation area in the area limited excavation control in the previous embodiment described with reference to FIG.
A linear equation connecting two points of 2 * (see FIG. 4) is calculated by the following equation (Equation (3)), and this is set as a target excavation locus.

Y = (Y2 * 1-Y1 *) X / (X2-X
1) Ten (X2Y1 * 1-X1Y2 *) / (X2-X1) The front attitude calculation unit 9b detects the detected rotation angles α, β,
The position and orientation of the front work machine 1A are calculated based on γ and the dimensions of each part of the front work machine 1A which have been input in advance, and the position of a predetermined portion of the front work machine 1A, for example, the tip position of the bucket 1c is calculated. This calculation is the same as the calculation of the calculation unit 9b in the previous embodiment.

The target speed vector calculator 9n calculates a target speed vector Vc at the tip of the bucket 1c. The gradient θ of the target speed vector Vc is determined by the target excavation trajectory setting calculation unit 9A.
It is a linear slope of the target excavation trajectory obtained in a.
The absolute value of the target speed vector Vc is set to a value Vca set in advance.

The target boom angular velocity calculating section 9p and the target arm angular velocity calculating section 9q include a target speed vector calculating section 9A.
target velocity vector V at the tip of bucket 1c calculated in b
c is decomposed in the X and Y directions using the gradient θ and the absolute value Vca. The calculation formula to be decomposed is as follows.

Vcx = Vca × cos θ Vcy = Vca × sin θ Further, the equations (1) and (2) described in the previous embodiment are differentiated, and the target boom angular velocity αc ′,
When the target arm angular velocity βc ′ is obtained, it is as follows. The angular velocity of the bucket is 0.

Αc ′ = (M4 · Vcx + M2 · Vcy) / (M1 · M4−M2 · M3) βc ′ = (− M3 · Vcx−M1 · Vcy) / (M1 · M4−M2 · M3) where M1 = L ₁ · cos α + L ₂ · cos (α + β) + L ₃ · cos (α + β + γ) M2 = L ₂ · cos (α + β) + L ₃ · cos (α + β + γ) M3 = L ₁ · sin α + L ₂ · sin (α + β) + L ₃ · sin (α + β + γ ) M4 = L 2 · sin (α + β) + L 3 · sin (α + β + γ) to.

The target boom cylinder speed calculator 9r and the target arm cylinder speed calculator 9s perform link correction based on the target boom angular speed αc ′ and the target arm angular speed βc ′ to obtain the target boom cylinder speed _Vbc1 and the target arm cylinder speed. _Find V _ac1 .

In the feedback control amount calculating section 9t, the position deviation Δ between the position of the tip of the bucket 1c and the target excavation locus is calculated.
Correction calculation by position feedback is performed according to D.
Here, it is assumed that all causes of the position deviation are caused by the boom, and the correction by the position feedback is performed only for the boom cylinder speed. For example, in the case of the horizontal pulling operation by the arm cloud operation, when the deviation ΔD is +, that is, when the tip of the bucket 1c is on the target excavation trajectory, the extension operation of the boom cylinder (boom raising operation) is fast. A value obtained by multiplying ΔD by a feedback gain K (described later) is subtracted from the target boom cylinder speed V _bc1 , and conversely, when the deviation ΔD is −, that is, when the tip of the bucket 1c is below the target excavation locus, the extension operation of the boom cylinder is performed. (Boom raising operation) is slow, the deviation ΔD
_Is multiplied by the gain K to obtain the target boom cylinder speed V _bc1
, The target boom cylinder speed _Vbc1 is corrected so as to cancel the deviation from the target excavation trajectory. The operation unit 9t includes a feedback gain correction operation unit 9l.
When the learning correction mode is selected, the feedback gain K is changed from K1 to K2 (<K1).

FIG. 21 is a flowchart specifically showing the overall outline of the processing contents in the arithmetic unit 9t. Steps 110, 111a, and 111b in FIG. 21 are the same as steps 110, 111a, and 111b in FIG. 10 according to the previous embodiment. That is, in step 110, it is determined whether or not the signal from the composite operation correction switch 7c indicates a composite operation correction instruction. If the composite operation correction instruction has not been issued, the feedback gain K is set to K1 in step 111a, and If an operation correction instruction has been given, the feedback gain K is set to K2 in step 111b. K2 is a value smaller than K1. Further, the feedback gain K1 is an arbitrary value determined from characteristics in control, and the gain K1
If the value is too large, the control becomes oscillating, but if the value is too small, there is little correction by feedback, and control accuracy cannot be improved. Therefore, it is necessary to select an appropriate value for the gain K1. The feedback gain K2 is an arbitrary value smaller than K1 suitable for improving the accuracy of the learning correction process.

The processing of steps 110, 111a, and 111b is performed in the feedback gain correction calculator 91 included in the calculator 9e.

Next, the routine proceeds to step 200, where the position deviation ΔD between the tip position of the bucket 1c and the target excavation locus is calculated. The tip position of the bucket 1c is calculated by the front attitude calculation unit 9b, and the target excavation trajectory is set data of the setting calculation unit Aa.

Next, proceeding to step 201, it is determined whether or not the signal from the trajectory control switch 7Aa indicates horizontal pulling. If horizontal pulling is specified, the procedure determines in step 202 whether the difference ΔD is positive or negative. If ΔD is positive, the tip of the bucket 1c is on the target excavation trajectory and the extension operation (boom raising) of the boom cylinder is fast, and thus the deviation ΔD is multiplied by the coefficient K as described above in step 203. The value KΔD is subtracted from the target boom cylinder speed V _bc1 , and if the deviation ΔD is negative, the tip of the bucket 1c is below the target excavation locus and the extension operation (boom raising) of the boom cylinder is slow. As described above, the value KΔD obtained by multiplying the deviation ΔD by the feedback gain K as described above is added to the target boom cylinder speed V _bc1 to cancel the deviation from the target excavation locus. The target boom cylinder speed _Vbc1 is corrected as described above.

On the other hand, if the signal from the trajectory control switch 7Aa does not indicate horizontal pulling, the process proceeds to step 205, where it is determined whether the signal from the trajectory control switch 7Aa indicates horizontal pressing, and Is determined, the sign of the deviation ΔD is determined in step 206, and the deviation Δ
If D is positive, since the tip of the bucket 1c is on the target excavation locus and the contraction operation (boom lowering) of the boom cylinder is slow, the value KΔD obtained by multiplying the deviation ΔD by the coefficient K in step 207 is set as the target. If the deviation ΔD is negative in addition to the boom cylinder speed V _bc1 , the tip of the bucket 1c is below the target excavation trajectory, and the contraction operation (boom lowering) of the boom cylinder is fast. pull the value KΔD multiplied by the feedback gain K from the target boom cylinder speed V _bc1, it corrects the respective so as to cancel the deviation between the target excavation locus target boom cylinder speed V _bc1.

As described above, the target boom cylinder speed V
_bc1 corrected by moving the boom cylinder and the arm cylinder in the target arm cylinder speed V _ac1 calculated between the target boom cylinder speed V _bc1 calculating unit 9s, bucket tip is as move along the target excavation locus.
When the composite operation correction switch 7c is ON and a composite operation correction instruction is given, the value KΔD obtained by multiplying the deviation ΔD by the feedback gain K is used to set the control coefficient K to a value K2 smaller than the normal coefficient K1. Becomes smaller, and even if there is a deviation ΔD between the tip of the bucket 1c and the target excavation trajectory, the correction acting on the operating speed of the boom to cancel the deviation is weakened. Therefore, the composite operation correction operation unit 9j
In the learning correction process of the command current-flow rate characteristic in
The error of the control operation that becomes a parameter of learning becomes remarkable,
The calculation accuracy of the correction value can be improved (described later).

In the valve command calculation section 9g, if the correction target cylinder speed of the boom cylinder 3a obtained in the calculation section 9t is in the boom raising direction, the flow control valve 105a
The boom raising target flow rate is calculated, and if the boom is in the boom lowering direction, the boom lowering target flow rate is determined, and the command values (command currents) of the proportional solenoid valves 150a and 150b are calculated from these target flow rates.

Here, the control unit 9A includes the command current-flow characteristics of the proportional solenoid valve 150a and the flow control valve 105a, and the command current-flow characteristics of the proportional solenoid valve 150b and the flow control valve 105a. Similarly, 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 as shown in FIG. 12 are stored. The command current of the proportional solenoid valves 150a and 150b is calculated using the relationship.

In the composite operation correction calculation 9j, learning correction processing of the command current-flow rate characteristics used in the valve command calculation unit 9g is performed by the trajectory control by the boom and the arm. The concept of the learning correction process is the same as the concept of the case where the learning correction process is performed in the area limited excavation control in the above embodiment.

That is, in the learning correction processing of this embodiment, the control mode is switched to the learning correction mode by turning on the composite operation correction switch 7c while the signal from the trajectory control switch 7Aa indicates the start of trajectory control. It is characterized in that it is performed while performing trajectory control. The correction target is a command current of the boom flow control valve 105a in the boom raising direction.
The flow characteristic and the command current-flow characteristic in the boom lowering direction are also characterized in that the variation in the command current-flow characteristic of the arm flow control valve 105b is absorbed by the correction of the command current-flow characteristic of the boom. Further, in the learning correction mode, the feedback gain K used in the feedback control amount calculation unit 9t is changed from K1 to a small value of K2, the correction amount of the feedback calculation at the time of the trajectory control is reduced, and the command current-flow rate characteristic varies. Another feature is that the error in the control operation is remarkable and the correction accuracy is improved.

The method of correcting the command current-flow rate characteristic of the boom is the same as that described with reference to FIGS. 13 (a), 13 (b) and 14 in the previous embodiment. However, FIG.
The boundary of the set area in 4 is a target excavation trajectory, and a target control range is set with the target excavation trajectory interposed therebetween in order to calculate a control operation error due to a variation in the command current-flow rate characteristic.

The contents of the learning correction processing in the composite operation correction calculation section 9Aj are substantially the same as those described in the previous embodiment with reference to FIGS. However, FIG.
Of the correction value calculation shown in the flowchart of FIG.
33A. That is, in step 131A, the signal from the trajectory control switch 7Aa is input, and it is determined whether or not the horizontal pulling operation is instructed. If the horizontal pulling operation is instructed, the process proceeds to step 132, where the learning correction processing for the boom raising is performed. If not, the process proceeds to step 133A, where it is determined whether or not the signal from the trajectory control switch 7Aa indicates a horizontal push operation. If the horizontal push operation is instructed, the process proceeds to step 134 to lower the boom. A learning correction process is performed.

Also, in the processing procedure in the learning correction mode in steps 141 to 149 of the flowchart shown in FIG. 17 of the present embodiment, the feedback gain K used in the trajectory control is K1 in the feedback control amount calculating section 9t.
To K2 (<K1) (step 1 in FIG. 21).
11b) In both the case where the horizontal pull is automatically performed by the arm cloud and the boom raising operation, and the case where the horizontal pushing is automatically performed by the arm dump and the boom lowering, the feedback gain K is added to the deviation ΔD. (The value used in steps 203 and 204 in FIG. 21) becomes smaller, and even if a deviation ΔD between the tip of the bucket 1c and the target excavation trajectory occurs, the operation speed of the boom is canceled so as to cancel the deviation. Working correction is weakened. For this reason,
An error in the control operation due to the variation in the command current-flow rate characteristic becomes remarkable, and the frequency at which the bucket tip is located within the target control range shown in FIG. 14 decreases, that is, the frequency at which the bucket tip is below or above the target control range. Increases, and as a result, FIG.
In steps 146 and 147 of step 7, the number of additions and the number of subtractions in the counters 1 to 8 increase, and in step 149, the counters 1 to 8
The calculation accuracy of the correction value obtained from the value of is improved.

According to the present embodiment configured as described above, the same effects as those of the above embodiment can be obtained in a hydraulic drive device having a trajectory control function using an electric lever type operation lever device.

That is, 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, and at that time, the feedback gain is lowered to perform the control. Variations in the current-control amount characteristic appear remarkably as control deviations, and the accuracy of the correction value obtained based on this deviation is high. The operation of the working device can be controlled with high accuracy even when there is mutual interference of hydraulic pressure due to the combined operation of the actuator. 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.

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.

In the above embodiment, the command current-flow rate characteristic is corrected. However, if the command current-actuator speed characteristic is used instead of the command current-flow rate characteristic in the valve command calculation units 9g and 9Ah, the command current-actuator speed characteristic is corrected. 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 area-limited excavation control and trajectory control. However, the present invention may be applied to a hydraulic excavator that performs other control.

[0122]

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.

Further, when the correction value of the command current-control amount characteristic is obtained, the control coefficient is changed to a value smaller than the normal value, so that the error due to the variation of the command current-flow rate characteristic becomes remarkable, and the correction accuracy is improved. I do.

[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 illustrating the entire processing contents in a direction conversion control correction speed vector calculation unit.

FIG. 7 is a flowchart illustrating a process of a direction conversion control calculation in a set area in a direction conversion control correction speed vector calculation unit.

FIG. 8 is a diagram illustrating a relationship between a distance Ya between a tip of a bucket and a boundary of a setting area and a coefficient h in a direction conversion control calculation.

FIGS. 9A and 9B 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. 9A illustrates a case where the bucket tip approaches the boundary of the set area, and FIG. Is away from the boundary of.

FIG. 10 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.

11A and 11B 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. 11A illustrates a case where the bucket tip is separated from the boundary of the set area, and FIG. In this case.

FIG. 12 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. 13 is a diagram illustrating a concept of correcting a command current-flow rate characteristic.

FIG. 14 is a diagram showing a target control range used for obtaining a correction value of a command current-flow rate characteristic.

FIG. 15 is a flowchart illustrating the entire processing content of a learning correction process in a composite operation correction calculation unit.

FIG. 16 is a flowchart showing a learning mode process.

FIG. 17 is a flowchart illustrating details of learning correction processing for boom raising and boom lowering in the learning mode processing.

FIG. 18 is a view similar to FIG. 1, showing a control device for a hydraulic work machine according to another embodiment of the present invention.

FIG. 19 is a block diagram illustrating a control function of the control unit.

FIG. 20 is a block diagram illustrating processing functions of a setting / control calculation unit among the control functions of the control unit.

FIG. 21 is a flowchart illustrating processing contents of a feedback control amount calculation unit.

FIG. 22 is a flowchart showing a learning mode process.

[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 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] 1. A target value of a control amount is calculated by a control operation using a control coefficient, and a command current value is calculated from the target value of the control amount according to a preset command current-control amount 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. An error in the control operation of the working device from position information when controlling the operation of the working device by performing a combined operation of the plurality of hydraulic actuators according to a command from the combined operation correction instructing device. Correction value calculating means for calculating a correction value of the command current-control amount characteristic based on the error; characteristic correction means for correcting the command current-control amount characteristic using the correction value; When there is a command from the operation correction instructing means, a control coefficient correcting means for changing a control coefficient used in the control calculation is provided. Hydraulic work machine control device. 2. A hydraulic work machine according to claim 1, wherein said control coefficient correction means changes a control coefficient used in said control calculation to a value smaller than that in a normal control. 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 controlling the operation of said working device by compoundly operating said plurality of hydraulic actuators. A first calculating means for comparing the 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 And a second calculating means for calculating a correction value of the command current-control amount characteristic based on a calculation result. 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.