JPH09228404A - Work machine control method of construction machine and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contrive to enhance finishing accuracy and uniform the hardness of a finished surface in the formation of a slope by a work machine of a construction machine. SOLUTION: A position following feedback control system consists of an operation lever 33, a controller 21, a control valve 38 feedback loops 18bm, 18st and 18bk from transmitted each of angle sensors 16bm, 16st and 16bk and so forth. Pressure sensors 32bm and 32st and a rolling power setting apparatus 42 are provided on this control system where the pressure sensors are designed to detect the load of the work machine by detecting a cylinder load pressure applied to work machine operation cylinders 14bm, 14st and 14bk while the rolling pressure setting apparatus 42 is designed to control the load of this work machine for a specified target value. The position control system control the elevation of the work machine so that the load of the work machine detected with the pressure sensors 32bm and 32st may conform to a value predetermined by the rolling pressure setting apparatus 42 in automatic mode and lifts the work machine, thereby lowering the rolling pressure and lowers the work machine, thereby raising the rolling pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine control method and apparatus for construction machines such as hydraulic excavators and backhoes.

[0002]

2. Description of the Related Art FIG. 4 shows a system configuration diagram of a conventional hydraulic excavator. In this hydraulic excavator, an upper swing body 12 is provided on a lower traveling body 11, and a front working machine 13 is provided on the upper swing body 12.

In the front working machine 13, a base end of a boom 15bm which is rotated by a boom cylinder 14bm is pivotally supported by the upper swing body 12, and the stick cylinder 14 is attached to the tip of the boom 15bm.
The vicinity of the base end of the stick 15st rotated by the st is pivotally supported, and the bucket cylinder 14bk is attached to the tip of the stick 15st.
A bucket 15bk pivoted by is pivotally supported.

The boom forming the front linkage
The rotation angles of 15bm, stick 15st and bucket 15bk are the angle sensors 16bm, 16st, 16bk such as resolvers.
Is detected by, and the angle detection signal is input to a controller 21 including a microcomputer via feedback loops 18bm, 18st, 18bk connected to a signal converter 17 mounted on the upper swing body 12.

A display switch panel 22 as an input / output device is connected to the controller 21, and a control switch 23 for starting automatic control or for controlling engine speed provided on an operating lever and an engine speed sensor 24a. Engine pump controller 24 for controlling the engine and pump based on the engine speed detected by the pressure sensor for detecting the position of the operating lever
25, a tilt angle sensor 26 for detecting the tilt angle of the vehicle, etc. are connected to the input terminals of the controller 21, respectively. Further, the solenoid valve 27 is connected to the output terminal of the controller 21.

The controller 21 includes a boom cylinder 14
bm, stick cylinder 14st and bucket cylinder 14
Boom with closed loop control compensator for controlling bk and fed back from angle sensors 16bm, 16st, 16bk
The operating stroke of each cylinder is constantly grasped from the rotation angle detection signals of 15bm, stick 15st and bucket 15bk, and the actual position and speed of boom 15bm, stick 15st and bucket 15bk are fed back in relation to the command signal from the operating lever. The feedback control system for position tracking is controlled.

The controller 21 performs closed-loop control compensation so as to eliminate the error between the target signal for each cylinder operation calculated by the microcomputer for performing water averaging work and slope shaping work and the feedback signal. Electromagnetic proportional valve (not shown) with the signal calculated by the device
Is controlled electrically, and the control valve (not shown) is pilot-controlled by the pilot pressure generated from this solenoid proportional valve, whereby the boom cylinder 14bm, the stick cylinder 14st and the bucket cylinder 14bk are respectively expanded and contracted to control the water average. It is possible to automatically perform the trajectory control of the bucket tip and the constant control of the bucket angle in the bending work and the illustrated slope shaping work.

As described above, the conventional hydraulic excavator uses the microcomputer to automatically perform the trajectory control of the bucket tooth tips and the constant control of the bucket angle in the water averaging work and the slope shaping work. Boom 15bm, Stick 15st and Bucket 15 that make up the linkage
The closed loop control is performed by feeding back the detection signals obtained from the angle sensors 16bm, 16st, 16bk of the rotating parts of the front linkage to the controller 21 so that the displacements of the bk cylinders 14bm, 14st, 14bk follow the target displacement. Is going.

[0009]

In this case, the bucket 15
The load of bk is regarded as a disturbance, and the rolling pressure on the excavated surface is not actively controlled. Therefore, not only is there no guarantee that the hardness of the finished surface will be uniform, but also the accuracy of finishing will deteriorate due to fluctuations in the excavating force and the work efficiency will deteriorate due to the cylinder speed decreasing during overload.

The present invention has been made in view of the above point, and improves the finishing accuracy by finishing the position of the working machine and automatically controlling the working machine load such as excavation force and rolling force. An object of the present invention is to provide a work machine control method for a construction machine and a device therefor capable of achieving uniform surface hardness.

[0011]

According to a first aspect of the present invention, there is provided a work machine control method for a construction machine including a position control feedback control system for a work machine working cylinder, wherein a cylinder load applied to the work machine working cylinder is provided. A working machine control method for a construction machine, wherein a working machine load is detected by detecting pressure, and a target value of a position tracking feedback control system is determined based on a feedback signal related to the working machine load.

Then, the working machine load such as the rolling force is detected by detecting the cylinder load pressure, and the position of the working machine operating cylinder is controlled so that a predetermined rolling force can be obtained. For example, the rolling force is lowered by raising the bucket position, and the rolling force is raised by lowering the bucket position.

According to a second aspect of the present invention, in the work machine control method for a construction machine according to the first aspect, the target value of the work machine load control is set with priority in relation to the position tracking control. It was done.

When importance is attached to work implement load control, the priority is set to a large value so that a target constant rolling force can be obtained.

According to a third aspect of the present invention, in the work machine control method for a construction machine according to the first or second aspect, the rolling force is detected as the work machine load, and the work machine position is controlled in the vertical direction. It controls the rolling force.

The position control feedback control system controls the work implement position in the vertical direction, so that the rolling pressure as the work implement load is also feedback controlled.

According to a fourth aspect of the present invention, in a control device for a working machine for excavation equipped with a feedback control system for tracking the position of a working machine working cylinder, the cylinder load pressure applied to the working machine working cylinder is detected. A load pressure detecting means for detecting a work implement load, and a work implement load setting device for determining a target value of the position tracking feedback control system based on a relationship between the load pressure detecting means and a feedback signal relating to the work implement load detected by the load pressure detecting means. It is a working machine control device for a construction machine provided.

Then, the working machine height is automatically adjusted so that the working machine load detected by the load pressure detecting means becomes a value preset by the working machine load setter, and the rolling force is adjusted by, for example, raising the working machine. Lower the working machine to raise the rolling force.

According to a fifth aspect of the present invention, in the work machine control device for a construction machine according to the fourth aspect, the work machine load control is prioritized between the position tracking control and the target value input section relating to the work machine load. A priority setting device for setting the degree is provided.

When the work implement load control is prioritized by the priority setter, a target constant work implement load is obtained, and the priority setter lowers the work implement load control priority. By relatively prioritizing the position tracking control, the position tracking accuracy can be improved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a boom cylinder 14bm and a stick cylinder 14st are attached to a front linkage composed of a boom 15bm, a stick 15st and a bucket 15bk.
A front working machine is configured by attaching a bucket cylinder 14bk (hereinafter, these cylinders may be collectively referred to as a working machine operating cylinder 14).

A stick operation lever 33 for instructing the target speed of the bucket tooth tip in the excavation direction to the input side of the controller 21, which is the center when controlling the front working machine.
And a slope angle setter 41 for setting a target finishing slope angle θ in the shaping work of the slope A, and a working machine load setting for setting a target rolling pressure (cylinder target load pressure) by the bucket 15bk. Rolling force setting device 42 and slope angle setting device
Bucket tip trajectory control and rolling force setter set in 41
Priority (weight) in control of rolling force set in 42
And a priority setting unit 43 for setting.

Further, on the output side of the controller 21, an electromagnetic proportional valve 35 for outputting a pilot pressure proportional to an input electric signal, and a hydraulic pressure source by a spool whose displacement is controlled by the pilot pressure from the electromagnetic proportional valve 35 (see FIG. A control valve 36 for controlling the hydraulic pressure and the amount of oil supplied from each work machine operating cylinder 14 (not shown).

Further, angle sensors 16bm, 16st, 16bk such as resolvers for detecting the respective rotation angles of the boom 15bm, the stick 15st and the bucket 15bk (hereinafter, these angle sensors may be collectively referred to as the respective angle sensors 16). Therefore, the closed loop control system is configured by providing the position tracking feedback loops 18bm, 18st, and 18bk (hereinafter, these loops are collectively referred to as the feedback loop 18) to the controller 21.

Pressure sensors 32bm, 32st as load pressure detecting means are provided for the hydraulic oil supply / discharge lines 31bm, 31st to the boom cylinder 14bm and stick cylinder 14st, respectively, and the boom cylinder 14bm and stick are provided by these pressure sensors 32bm, 32st. Detects cylinder load pressure of cylinder 14st. In particular, when detecting the rolling force obtained when the bucket 15bk is moved up and down, it is preferable to mainly detect the cylinder load pressure of the boom cylinder 14bm.

Then, the rolling pressure is calculated by multiplying the cylinder load pressure of the boom cylinder 14bm by the substantial pressure receiving area in the cylinder, and the cylinder load pressure of the stick cylinder 14st is multiplied by the substantial pressure receiving area in the cylinder. The excavating force can be calculated by.

Further, a working machine load feedback loop 44 of the cylinder load pressure detected by the pressure sensors 32bm, 32st is provided from the pressure sensors 32bm, 32st to the controller 21.

The controller 21 is a working cylinder for each working machine.
Closed loop control compensator 52bm for controlling 14 respectively,
52st, 52bk, and the actual position and speed of these front linkages by the rotation angle detection signals of the boom 15bm, the stick 15st, and the bucket 15bk detected by the angle sensors 16 and fed back, and their angular velocity signals. Indirectly, each working machine operating cylinder 14
The boom 15bm, stick 15st and bucket 15bk are controlled via the solenoid proportional valve 35 so that the boom 15bm, stick 15st and bucket 15bk follow the position and speed command signals from the slope angle setter 41 and the operating lever 33. The valve 36 is feedback-controlled.

That is, the feedback control of the controller 21 eliminates the error between the feedback signal and the target signal for each cylinder operation calculated by the microcomputer for performing the water averaging work and the slope shaping work. The electromagnetic proportional valves 35 for boom, stick and bucket are electrically controlled by the signals calculated by the closed loop control compensators 52bm, 52st and 52bk.

These solenoid proportional valves 35 pilot-control the spools of the boom, stick and bucket control valves 36 by the pilot pressure output, and control the spools by the operating oil pressures output from the control valves 36. The work machine operating cylinders 14 are respectively controlled to expand and contract to automatically perform trajectory control of bucket tip and constant control of bucket angle in water averaging work and illustrated slope shaping work.

As shown in FIG. 2, the pressure sensors 32bm and 32st provided as load pressure detecting means for the boom cylinder 14bm and the stick cylinder 14st respectively extend toward the extension side (head side) of each cylinder. It consists of a pressure sensor 32h provided and a pressure sensor 32r provided on the contraction side (rod side). The extension side load pressure detected by the pressure sensor 32h and the contraction side load pressure detected by the pressure sensor 32r The differential pressure, that is, the cylinder load pressure is detected.

The feedback loop 44 of the cylinder load pressure and the rolling pressure setting device 42 are connected to a comparator 45, and the comparator 45 is connected to a computing device 46 for calculating a vertical target velocity of the bucket tooth tip. A multiplier for connecting and multiplying the output line of the computing unit 46 with the signal from the priority setting unit 43
A limiter 48 is provided via 47, and the upper and lower limits of the bucket tip vertical direction target speed related to the rolling force are set by the limiter 48.

The stick operating lever 33, the slope angle setting device 41, and the limiter 48 are used as working machine operating cylinders.
It is connected to a calculator 51 for calculating 14 target positions and speeds by a microcomputer.

The target value line from the calculator 51 is connected to the closed loop control compensator 52. This closed loop control compensator
52 is a feedback loop for the target signals (boom, stick, and bucket target positions and speeds) output from the calculator 51 for water averaging work, slope shaping work, and rolling work. It has a compensation circuit that improves the control characteristics (stability, responsiveness and steady-state deviation) necessary for the detection signals (boom, stick, bucket actual position and speed) fed back via 18 to follow accurately. Boom, stick, and bucket electromagnetic proportional valves 35 are controlled by the output electric signals.

Next, a specific control method will be described with reference to FIGS.

First, by setting the finishing slope angle θ in the shaping operation of the slope A by the slope angle setting device 41, the stick operation lever 33 is moved to set the digging direction target speed of the bucket tooth tip. When instructed, the calculator 51 calculates and outputs the target position and speed of each working machine operating cylinder 14.

On the other hand, in order that the rolling pressure of the excavation surface becomes a preset value, the differential pressure between the pressure sensors 32h and 32r provided on the extension side and the contraction side of each working machine operating cylinder 14 is
The value set by the rolling pressure setter 42 is compared with the value set by the comparator 45, and the bucket height position is automatically adjusted so that the differential pressure becomes the set value.

That is, the rolling force of the excavation surface is lowered by raising the position of the bucket 15bk, and the rolling force is raised by lowering the position of the bucket.

At this time, the bucket tooth tip position deviates from the preset target trajectory, but the cylinder load pressure control (working machine load control) that follows the differential pressure of the cylinder and the conventional bucket tooth tip trajectory control (cylinder load control). By setting the priority (weight) with respect to position tracking control) by the priority setting unit 43, the error from the target locus can be adjusted.

For example, as shown in the dotted line along the ground in FIG. 3A, when the bucket tip locus control is prioritized (when the weight of the locus control is increased), the bucket tip locus (accuracy of finishing surface) Can be improved. At this time,
As shown by the solid line in FIG. 3 (B), the excavating force tends to fluctuate.

On the other hand, when the weight of the rolling force control is increased as shown by the thick dotted line along the target excavation force in FIG. 3B (when the priority of the rolling force is increased), the excavation force is kept substantially constant. However, the rolling force can be accurately controlled.
At this time, as shown by the dotted line at the uppermost position in FIG.

As described above, the target bucket tooth locus is set by the slope angle setting device 41, and the rolling force setting device is set.
Set the target rolling pressure (cylinder target load pressure) with 42,
Then, by setting the priority (weight) between the rolling force control and the bucket tooth tip trajectory control by the priority setting device 43, the hardness of the finished surface and the finishing accuracy are adjusted or selected depending on the priority. it can.

Then, according to the priority, the bucket 15bk under the semi-automatic linear excavation control moves up and down to control the rolling pressure. I.e. bucket 15bk
Moves along the finished surface and also operates in a direction perpendicular to the finished surface to compress the finished surface to a predetermined hardness.

[0045]

According to the first aspect of the present invention, in the position following feedback control system, the cylinder load pressure applied to the working machine operating cylinder is detected, and the working machine load such as excavating force and rolling force is set. Since the value is feedback-controlled, the original position-following feedback control system can improve the finishing accuracy, and the work implement load feedback control system controls the work implement load such as rolling force to improve the hardness of the finished surface. Can be made uniform.

According to the second aspect of the present invention, by setting the priority of the work implement load control in relation to the position follow-up control, for example, the hardness of the finished surface increases as the priority of the work implement load control increases. Can be made uniform. Further, at the time of overload, the work implement load control is prioritized over the position following control to prevent the cylinder speed from decreasing, so that the work efficiency can be prevented from decreasing.

According to the third aspect of the present invention, by controlling the position of the working machine in the vertical direction by the position following feedback control system, the rolling pressure as the working machine load can also be feedback-controlled.

According to the fourth aspect of the present invention, the load pressure detecting means for detecting the load of the work implement and the work implement load setting device for setting the work implement load are set by using the position tracking feedback control system. The feedback control system for position tracking ensures the desired finishing accuracy by the position tracking control, and the work machine load feedback control system controls the work machine load such as rolling force to finish the finished surface. Can be made uniform in hardness.

According to the fifth aspect of the present invention, the priority setting device can be used to select the control that gives priority to the work implement load control and the control that does not have that, that is, the control that gives priority to the position tracking control, according to the work situation. It is possible to deal with the work that emphasizes the uniformity of the excavating force or the rolling force and the work that emphasizes the position tracking accuracy such as the accuracy of the slope angle in the slope excavation.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an outline of a work machine control device for a construction machine according to the present invention.

FIG. 2 is a block diagram showing an embodiment of the above control device.

FIG. 3A is an explanatory view showing an example of bucket tooth tip trajectories that differ depending on the priority of bucket tooth tip trajectory control and rolling force control, and FIG. is there.

FIG. 4 is an explanatory diagram showing a system configuration of a conventional hydraulic excavator.

[Explanation of symbols]

 14bm, 14st, 14bk Working machine working cylinder 32bm, 32st Pressure sensor as load pressure detection means 42 Rolling force setter as working equipment load setter 43 Priority setter

Claims (5)

[Claims] 1. A work machine control method for a construction machine comprising a feedback control system for tracking the position of a work machine working cylinder, wherein the work machine load is detected by detecting a cylinder load pressure applied to the work machine working cylinder, A work machine control method for a construction machine, comprising: determining a target value of a position tracking feedback control system based on a feedback signal related to the work machine load. 2. The work machine control method for a construction machine according to claim 1, wherein a priority is set for the target value of the work machine load control in relation to the position following control. 3. The method for controlling a working machine of a construction machine according to claim 1, wherein the rolling machine force is detected as a working machine load, and the rolling machine pressure is controlled by vertically controlling the position of the working machine. . 4. A work machine control device for a construction machine, comprising a feedback control system for tracking the position of a work machine working cylinder, wherein a load pressure for detecting a work machine load by detecting a cylinder load pressure applied to the work machine working cylinder. Construction comprising a detection means and a work implement load setter that determines a target value of a position tracking feedback control system based on a relationship between a feedback signal relating to the work implement load detected by the load pressure detection means. Machine work equipment control device. 5. The construction according to claim 4, wherein the target value input section for the work implement load is provided with a priority setting device for setting the priority of the work implement load control with respect to the position following control. Machine work equipment control device.