JPS61225429A - Controller for working machine of power shovel - Google Patents

Abstract

PURPOSE:To make the operations of working machines easier by controlling such working machines as boom, arm, and bucket in such a way as to move the cutting edge of the bucket toward directions indicated by an operating lever with attitudes of lesser excavating resistance. CONSTITUTION:The angle between the straight-line portion 3a of the cutting edge of a bucket 3 and the advancing direction of the cutting edge is detected by an earth pressure meter 16 and a frictional force meter 17, and the signal is sent to an input port 41. Also, the angle between the tangent direction of the rear curved portion of the bucket 3 and the flowing direction of soil is detected by the meter 18 and a frictional force meter 19, and the signal is sent to the input port 41. On the basis of data from the input port 41, the rotational movement amounts of boom, arm, and bucket for moving the tip of the bucket toward a direction indicated by an operating lever while keeping the excavating resistance of the bucket at smaller values are calculated and the signals are sent out to oil-pressure circuits 70, 80, and 90.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a work machine control device for a work shovel.

[Conventional technology]

In order to move the bucket of the power shovel in the desired posture with less digging resistance and to move the bucket cutting edge in the desired direction or along the desired trajectory, it is necessary to
It is necessary to control the amount of rotation of each work equipment, such as the arm and bucket, but it requires considerable skill for the operator to do this by simultaneously or alternately operating the control levers that rotate each work equipment. was.

For this purpose, the movement trajectory of the bucket cutting edge (for example, a straight line, circular arc, etc.) and the attitude of the bucket relative to that trajectory are set in advance, and each work machine is automatically controlled so that the bucket moves in a predetermined attitude along this trajectory. Various types of work machine control devices for power shovels have been devised. However, this type of device has a problem in that the degree of freedom is small because the movement trajectory and the like must be taught in advance.

[Problem that the invention seeks to solve]

The present invention has been made in view of the above-mentioned circumstances, and provides a work equipment control device for a power shovel that can move the bucket in the optimum posture in the direction of movement when the direction of movement of the bucket cutting edge is specified. With the goal.

[Means for solving problems]

According to the present invention, the attitude of the bucket is determined based on the conditions that the excavation resistance of the bucket does not become large, that is, the soil flows smoothly inside the bucket, and the back surface of the bucket does not interfere with the soil. A control lever is provided for instructing the direction of movement of the boom, arm, and bucket, and each working machine of the boom, arm, and bucket is configured to move the bucket so that the bucket assumes the above-determined attitude and to move the bucket cutting edge in the direction specified by the control lever. I'm trying to control it.

[For production]

By simply instructing the moving direction of the bucket cutting edge using the operating lever, the bucket cutting edge can be moved in the specified direction while maintaining the optimum bucket posture with low digging resistance.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the principle of the present invention will be explained using FIGS. 1 and 2. In the excavation operation of a power shovel, the factors that increase excavation resistance include: 1) The angle α between the straight portion 3a of the bucket cutting edge and the advancing direction of the bucket cutting edge is not sufficiently small.

2) The rear curved portion 3b of the bucket 3 is used to press down the soil (stop the flow of soil) during excavation. That is, the angle β between the tangential force ~ of the rear curved portion 3b of the bucket 3 and the soil flow direction is not sufficiently small.

3) The back of the bucket collides with the excavated surface that has already been excavated (Figure 2).

etc.

Therefore, the above-mentioned factors 1) and 2) increase the excavation resistance.

To avoid 3), if you correct the amount of rotation of the bucket, or the boom and arm along with the bucket in 5, the bucket will at least be in a position with less digging resistance. Once the attitude of the bucket is determined in this way, the amount of rotation of each working device such as the boom, arm, and bucket required to move the tip in the desired direction is also determined.

FIG. 3 is a schematic configuration diagram showing an embodiment of a working machine control device for a power shovel according to the present invention. In the figure, the tachometers 10 and 11 are connected to the operating lever 8 (FIGS. 5 and 6).
It generates a signal indicating the direction of travel of the bucket cutting edge in relation to the operation shown in Figure).

Tachometers 10 and 11 generate signals indicative of the X and Y components of the direction of travel, respectively. In addition, the operation lever 8
As shown in FIG. 5, a joystick operating lever is placed in a cantilever shape at an appropriate position on the driver's seat, and the direction of movement of the bucket tip is instructed by the operating direction of the joystick operating lever.

The tachometers 12, 13, and 14 and the inclinometer 15 output signals necessary for calculating the position of the tip of the bucket with respect to a predetermined reference position of the excavator (for example, the rotational fulcrum of the poom 1). A total of 12 degrees 13 and 14 output signals indicating the rotation angle of each of the working machines of the pool 1, arm 2, and bucket 3, respectively, and the inclinometer 15 outputs a signal indicating the inclination angle of the arm shovel in the longitudinal direction. .

Earth pressure gauges 16, 18, and 20 and friction force gauges 17 and 19 are respectively placed at appropriate locations on the package and door, as shown in FIG. Note that the soil pressure gauge 20 is disposed on the back of the bucket, and the others are disposed inside the bucket. Further, the earth pressure gauge 16 and the friction force gauge 17, and the earth pressure gauge 18 and the friction force gauge 19 are arranged offset in the width direction of the notebook.

The soil pressure gauge 16 and the friction force gauge 17 are used to detect the angle α (see Fig. 1) formed between the straight portion 3a of the bucket cutting edge and the traveling direction of the bucket cutting edge. The pressure P1 in the direction perpendicular to the straight line portion 3a is detected, and the friction force meter 17 detects the friction force Fl of the palanquin flowing here.
Detect.

Similarly, the earth pressure gauge 18 and the friction force gauge 19 are connected to the Nonoket 3.
This is to detect the angle β (see Fig. 1) between the tangential direction of the rear curved portion 3b and the direction of soil flow.
is the pressure P of the soil flowing here in the direction perpendicular to the above tangential direction
2, and the friction force meter 19 specifically detects the friction force F of the inflowing soil.

The earth pressure gauge 20 detects whether the back surface of the bucket has collided with an excavated surface that has already been excavated, and detects the pressure Q3 in the right angle direction applied to the back surface of the bucket.

The output signals of the tachometer, inclinometer, earth pressure meter, and friction force meter are respectively converted into digital signals by A/D converters 30 to 40 and applied to the input port 41.

The storage/calculation device 42 uses the poom 1 and the arm 2 to move the tip of the bucket in the direction instructed by the operating lever 8 while maintaining the excavation resistance of the bucket 3 at a small value based on various data from the input port 41. Then, the amount of rotation of each working machine of the bucket 3 is calculated, and a signal indicating the flow rate of oil to the poom cylinder 5, arm cylinder 6, and bucket cylinder 7 necessary for the amount of rotation is outputted via the output port 43. Note that details of this storage/arithmetic device 42 will be described later.

The relay switches 61t62y63 are actuated as appropriate by signals applied from the output port 43 indicating the direction in which pressure oil flows to each cylinder, and are connected to the hydraulic circuit. A signal for switching each electromagnetic switching valve of 0.80.90 is output. on the other hand,
Signals indicating the flow rate to each cylinder output from the output port 43 are applied to control amplifiers 63, 64, 65 via D/A converters 50, 51, 52, respectively, where they are appropriately amplified and sent to the hydraulic circuit. 0.80.90 is added to the electromagnetic proportional switching valve that constitutes each proportional flow control valve.

Here, details of the hydraulic circuits 70, 80, and 90 will be explained. Note that since each hydraulic circuit has the same configuration, only the hydraulic circuit 70 will be explained.

FIG. 4 shows a detailed example of the hydraulic circuit 70, which includes a pump 71, an electromagnetic switching valve 72, and an electromagnetic proportional switching valve 7.
3. Decompression expansion pressure compensation valve 74, return filter 75, oil cooler 76, main relief valve 77 and safety valve 7
It consists of 8.79.

The electromagnetic switching valve 72 switches the direction of flow of pressure oil to the boom cylinder 5, and the solenoid 72m is a relay switch,
When energized by a signal from Chiro 0, it is switched to position ■, supplying pressure oil in the direction of extending the boom cylinder 5, and solenoid 72b is activated by a signal from Chiro 0, which switches to position ■. Pressure oil is supplied in the direction in which the boom cylinder 5 is retracted. Also, solenoid 72a*? When neither 2b nor 2b is biased, the return spring switches the position to the neutral position (3), and no pressure oil flows into or out of the boom cylinder 5.

On the other hand, the electromagnetic proportional switching valve 73 and the pressure reduction expansion pressure compensation valve 74 constitute a proportional flow rate control valve, and the spool position of the electromagnetic proportional switching valve 73 is controlled by the signal from the control amplifier f63, and the pressure flowing into and out of the boom cylinder 5 is controlled. Control oil flow rate.

The boom cylinder 5, arm cylinder 6 and bucket cylinder 7 are expanded and contracted by the hydraulic circuits 70, 80 and 90, respectively, and the boom 1, arm 2 and bucket 3 are expanded and contracted.
is rotated appropriately.

Next, the operation of the storage/arithmetic device 42 will be described in detail with reference to charts 70 shown in FIGS. 8 and 9.

First, when the operating lever 8 is operated (ste, floo)
, input a signal indicating the operating direction, that is, the traveling direction of the bucket cutting edge, and calculate the current position of the bucket cutting edge based on the output signals of the tachometer 12, 13, 14 and the inclinometer 15 (fl 10 ), This current position is input (step 101).

Next, as shown in FIG.
The movement target position B is set from the movement direction (direction of arrow AH) indicated by and the predetermined movement amount (ΔL) of the vehicle per unit time (Stella f102).

In the Stella f104, the current position, the previous target position stored in step 103, and the target position after the previous correction stored in step 106 are input, and in the Stella 7'105, from these positions, a correction value d=[ (Target position after previous correction + (previous target position - current position)/G1) - current position) XGK (1) is calculated, and the moving target position is corrected accordingly.

The above correction value d is for compensating for the fact that the bucket is not necessarily moving in the commanded direction due to load conditions and the like. In addition.

G is an integral compensation gain, and G is a position compensation gain.

Next, the current position of the bucket cutting edge, the corrected movement target position, and the rotation of each work machine to move the bucket cutting edge to the corrected movement target position are set on the condition that the bucket 3 is moved without changing its posture. Calculates the amount of movement, that is, the flow rate of oil to each cylinder, and outputs a command signal to supply that flow rate to each cylinder (Stella: 7'107)
. Note that the attitude of the bucket 3 at the current position (for example, the angle formed between the straight portion 3a of the bucket cutting edge and the horizontal plane) is determined by the tachometer 12913.14. Of course, it is detected from the output signal of the inclinometer 15.

The electromagnetic switching valve of the hydraulic circuit of each working machine and the susol of the flow control valve are controlled according to the above command signal (Stella 7'l O
8), an appropriate flow rate is supplied to each cylinder, and each cylinder expands and contracts (Step 7'109).

On the other hand, at step 7°200, the process shown in the flowchart of FIG. 9 is performed, and a command signal for correcting the attitude of the bucket 3, etc. is output.

That is, soil pressure gauge 16. i8*20 and friction force meter 17
．． 19 to pressure pl, pl, pm and frictional force F
1wF goose input step 201), Stella f202
In and 203, -α and -β are respectively determined by the following equations, pl -α=-... (2). -α and -β are the tangents of the angles α and β shown in FIG. 1, and are parameters indicating the smoothness of soil flow in the straight portion 3& of the bucket cutting edge and the rear curved portion 3b of the bucket 3, respectively.

Then, in steps 204 and 205, the calculated -α and -β respectively are predetermined range concavities with small excavation resistance, 0≦-α≦tu20' (4) 0≦-β≦-2
0°... Determine whether it falls within (5). When -α is within the range shown in equation (4) above, the correction dyne Kl for correcting the angle of the bucket cutting edge is set to O (step 206), and when it is outside the range, it is set to the correction dyne! The following formula, K1=kl (tanα−-20°) ... (
6) (step 207). Similarly, when -β is within the range shown in item (5) 2 above, the correction gain is used for rotating the bucket rear curved portion! If it is outside the range, set the correction gain to 1 using the following formula, K! =kl (tanβ--20°) ... (
7) (Ste, Gu 209).

On the other hand, in Step 210, it is determined whether the pressure P3 is 0 or not, and when Ps is O, the correction dyne Ks for avoiding interference on the back of the bucket is set to O (Step 211), and Ps is 0.
If not, the modified dyne is set to 3 and a certain constant gain is set to 3 (step 212).

Next, in step 7'213, the flow rate to each cylinder of the boom, arm, and bucket necessary for correcting the angle of the bucket cutting edge based on the above correction dyne is 1Δt1°K, Δt2a
e Calculate K1Δ'Sm. Similarly, step 21
4, the flow rate to each cylinder for rotating the bucket rear curved portion is 2Δt1b l based on the modified gain of 2.
K2Δt2b t Calculate K2Δtsb, step,
In 15, based on the correction gain 3, the flow rate to each cylinder to avoid interference on the back of the bucket is 3ΔL1c + 3Δt
2ce Calculate K5Δt3c. Note that the above Δt1
a~ΔLS* eΔt1b~ΔL5bt and Δt1c
~Δt3c is a spring e4 that differs depending on the movement of the bucket to be corrected, but even for the same correction movement, it differs depending on the position and posture of the blade edge of the bucket.

Therefore, the flow rate (Δt1a to ΔL
s c, ) is read out as appropriate from a memory table stored for each correction operation and according to the position and posture of the blade edge of the bucket, for example.

For each corrective action as described above, the flow rate to each cylinder is added for each cylinder as shown in the following equation.

A command signal indicating these flow rates is output (step 21
6).

The above command signal is superimposed on a command signal for moving the bucket cutting edge in a specified direction without changing the attitude of the bucket, and is used to control the electromagnetic switching valve of the hydraulic circuit of each work machine and the spool of the flow control valve. (step 108)
).

Then, each cylinder expands and contracts, and the tachometer reaches 12°13114
When the output changes, the current position of the bucket is calculated from this changed output (Step 110), and the above process is executed again based on the current position and the command for the direction of movement of the cutting edge.

In this way, by simply operating the operating lever 8 in the desired direction, the 1o(lator) adjusts the attitude of the bucket to keep the resistance of the soil flowing into the bucket within a predetermined range and to avoid interference with the back of the bucket. The bucket can be moved in any desired direction.

In this embodiment, a cantilever-shaped joystick is used as the operation lever, but the joystick is not limited to this, and any type of joystick may be used as long as it indicates the direction of movement of the bucket. In addition, although the resistance due to soil flowing into the bucket is detected at two locations, the straight part of the bucket blade edge and the curved part at the rear of the bucket, it is also possible to detect only the straight part of the bucket blade edge, and the resistance due to soil cannot be detected here. In addition to the method of detecting the angle α based on the outputs of the earth pressure meter and friction force meter in this embodiment, the angle (
This angle may be determined based on the rotating direction (which can be detected from the tachometer 12+13t14 and the inclinometer 15) and the advancing direction of the bucket cutting edge indicated by the operating lever.

In addition, as a corrective action of the bucket, for example, if you want to primarily reduce the resistance due to soil, you may extend the bucket cylinder, and if you want to avoid interference on the back of the bucket, you may retract the bucket cylinder. When it is necessary to simultaneously reduce the amount of interference and avoid interference on the back surface of the bucket, one of them (for example, avoidance of interference on the back surface of the bucket) may be given priority.

〔Effect of the invention〕

As described above, according to the present invention, the bucket can be moved in a desired direction with less digging resistance by simply instructing the moving direction of the bucket cutting edge using the operating lever, making the operation extremely simple.

[Brief explanation of drawings]

1 and 2 are diagrams used to explain the principle of the present invention, respectively, and FIG. 3 is a schematic configuration diagram showing an embodiment of a work machine control device for a work shovel according to the present invention. Figure 4 is a circuit diagram showing details of the hydraulic circuit in Figure 3; Figure 5;
6 and 7 are diagrams respectively used to show the mounting positions of the respective detectors in FIG. 3, FIG. 8 is a flowchart showing the processing operation of the device of the present invention, and FIG. A flowchart showing the details of the main part of the processing operation, FIG.
FIG. 3 is a diagram used to explain a method of setting a bucket movement target position in the flowchart of the figure. l...boom, 2...arm, 3...bucket,
4...Boom cylinder, 5...Arm cylinder, 6
... Bucket cylinder, 10-14 ... Tachometer, 1
5... Inclinometer, 16, 18.20... Earth pressure gauge, t7
．． t9... Friction force meter, 42... Memory/calculation device, 7
0.80°90... Hydraulic circuit. Fig. 1 Fig. 4 Arm cylinder etc. Fig. 5 j Bagut construction pressure revision Fig. 8

Claims (4)

[Claims] (1) An operating lever for instructing the moving direction of the bucket cutting edge of a power shovel, a position detecting means for detecting the current position of the bucket cutting edge, and an instruction using the current position of the bucket cutting edge detected by the position detecting means and the operating lever. a first calculation for calculating rotation commands for the boom, arm, and bucket of the power shovel in order to move the bucket blade in the specified movement direction without changing the attitude of the bucket based on the specified movement direction of the bucket blade; a smoothness detection means for detecting the smoothness of soil flow at a suitable position inside the bucket; a collision detection means for detecting a collision between the back surface of the bucket and an excavated surface that has already been excavated; The detected smoothness falls within the preset range,
and second calculation means for calculating an attitude correction amount for correcting at least the attitude of the bucket in a direction in which the collision detection means does not detect a collision; A work equipment control device for a power shovel, comprising: and drive means for controlling the rotation of each bucket. (2) The working machine control device for a power shovel according to claim 1, wherein the operating lever is a joystick arranged in a cantilevered manner, and the operating direction of the joystick instructs the moving direction of the bucket cutting edge. (3) The working machine control device for a power shovel according to claim 1, wherein the soil flow detected by the smoothness detection means is a cutting edge portion and a rear curved portion inside the bucket. (4) The smoothness detection means includes a detection means for detecting vertical soil pressure P and frictional force F at the detection position, and an angle of the following formula based on the soil pressure P and frictional force F, tan^-^1( A work machine control device for a power shovel according to claim (1), comprising means for calculating P/F).