JPH0788673B2 - Power shovel work machine controller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a work machine control device for a power shovel, and particularly to a technique for automatic excavation.

[Conventional technology]

As is well known, a power shovel has a working machine such as a bucket, an arm, and a boom, and these working machines are individually driven by a bucket cylinder, an arm cylinder, and a boom cylinder to move the bucket in a desired trajectory and posture. Simultaneous control of expansion and contraction of each cylinder is essential.

Therefore, in order to move the bucket with a desired trajectory and posture, the operator must operate the operation levers corresponding to the bucket, the arm, and the boom simultaneously or alternately, which requires skill. .

In addition, unskilled personnel have caused unnecessary increase in excavation resistance by not directing the blade edge of the bucket in the traveling direction or interfering with the excavation surface after shaving the bucket bottom plate during excavation.

On the other hand, movement trajectories of the bucket blade tip (for example, straight lines, arcs, etc.) and bucket postures for these trajectories are set in advance, and the bucket, arm, and boom are automatically controlled so that the bucket blade tip moves along this trajectory. Various types of power shovel control devices have been proposed.

[Problems to be solved by the invention]

However, in these conventional devices, the excavation locus is fixed, and therefore, even when the bucket hits hard soil or an obstacle during excavation, the bucket moves according to the set excavation locus, resulting in relief loss. Occurs, and there is a problem in that efficiency is reduced.

The present invention has been made in view of such an actual situation, and reduces relief loss by correcting the set trajectory according to the actual load, and always excavates a certain amount of soil even when the trajectory is corrected. To get it.

[Means for solving problems]

Therefore, in the present invention, the reference movement trajectory of the bucket blade edge approximated by a plurality of points and each bucket attitude when the bucket blade edge is located at these plurality of points are preset,
Each bucket blade, arm and boom are divided by the plurality of points such that the bucket blade edge moves along the plurality of points from the designated excavation start position, and the bucket takes the set posture at the plurality of points. In a configuration that automatically rotates in units of excavation sections, load detection means for detecting a load, and when the detection value of the load detection means during the automatic excavation exceeds a first set value, the detection is performed. A first means for driving the boom upward until the value reaches a second set value smaller than the first set value, and restarting automatic excavation of the remaining section with the bucket blade position that has been driven upward as a restart point; After the automatic excavation is resumed, when the sub-automatic excavation is completed up to a predetermined section, the excavation volume from the beginning of the excavation to the predetermined section and the excavation volume of the remaining section are added to drive the boom upward. A second means for subtracting the added value from the excavation volume based on the reference movement trajectory when not touching, and adding a section for performing linear excavation for the volume corresponding to the subtracted value before the remaining section. To

[Action]

The first set value is set to a value slightly smaller than the relief pressure, for example. For this reason, when the work equipment load increases,
The boom rises before the oil relieves, reducing the load. The boom is stopped when the load is reduced to the second set value, and the automatic excavation of the remaining section is restarted after that position is restarted. Further, after that, when the automatic excavation ends up to a predetermined section such as an intermediate point, the second means adds a linear excavation section,
The amount of excavated soil can be kept constant even when the trajectory is modified.

〔Example〕

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

FIG. 2 shows a schematic configuration of the power shovel,
An upper swing body 2 is rotatably supported on the traveling body 1, one end of a boom 3 is pivotally supported by the swing body 2, and an arm 4 is pivotally supported by the other end of the boom 3. A bucket 5 is rotatably supported at the other end, and the boom 3, the arm 4 and the bucket 5 are rotationally driven separately by a boom cylinder 6, an arm cylinder 7 and a bucket cylinder 8.

Here, the length, angle, etc. of each part of the working machine are defined as shown in FIG. That is, the point A is the boom rotation point, the point B is the arm rotation point, the point C is the bucket rotation point, and the point D is the bucket blade tip point. The length between l ₁ ; points A and B l ₂ ; point B , C length l ₃ ; length between points C and D α: angle between line segment AB and vertical axis (boom angle) β; angle between line segment BC and extension line of line segment AB ( Arm angle) γ; Angle between line segment CD and extension of line segment BC (bucket angle) δ; Angle between excavation direction u and bucket bottom plate (excavation angle) ε; Excavation direction u and line segment CD Make it a corner. The bucket attitude is defined by the angle ε and the like.

First, a method of setting an excavation trajectory during automatic excavation will be described. In this embodiment, the excavation locus for the bucket blade edge as shown in FIG. 4 is set. This locus is an arc locus having a radius R centered on a predetermined point 0, and the arc locus is approximated by _n points P ₁ , P ₂ , ..., P _n . At the time of setting the locus, the excavated soil amount V (hatched portion in the figure) for one time is obtained by multiplying the bucket full amount by a predetermined number k (= 1 to 3), and the excavation depth d is the length of the line segment CD ( = L ₃ ) and a predetermined number e (=
0.1 to 1.5) and the angle ψ is an appropriate value between 10 ° and 180 °. These values k, e, ψ and the radius R of the arc are values determined according to the soil quality, the bucket shape, the work content, etc., and the reference excavation locus is determined by specifying these values. Further, as described above, the n points P _{1 to} P _n are approximated to the excavation locus thus determined, and these points P _{1 to} P _n are set as the target position of the bucket blade edge for each unit excavation section. To do. The positions of the points P _{2 to} P _n are set based on the position of the excavation start point P ₁ . Then, each of these target positions P ₁
The bucket attitude, that is, the angles ε _{1 to} ε _n are determined in advance for each P _n . When determining the bucket attitude ε,
The excavation resistance is made as small as possible by reducing the excavation angle δ at the start of excavation and by reducing the excavation angle δ within the range where the back of the bucket does not interfere with the soil as much as possible during excavation. That is, in this excavation, by driving the boom, the arm, and the bucket at the same time, the virtual line OD is moved to the unit angle Δφ (=) so that the bucket follows the target positions P _{1 to} P _n with the postures ε _{1 to} ε _n.
ψ / n) rotate each.

The automatic excavation in this embodiment is executed according to the procedure shown in FIG. 5, and its outline will be described below. This device is provided with an operation pedal 10 for instructing an automatic excavation mode, in addition to two operation levers 11 and 12 for giving a rotation command and a rotation command for a boom, a bucket, and an arm. By (stepping on the pedal continuously), automatic excavation is performed along the arc locus.

First, the operator operates the operation levers 11 and 12 to move the blade edge of the bucket to a desired excavation start position (the fifth operation).
(A)) By depressing the operation pedal 10, the automatic excavation mode is selected and the excavation start position is designated (Fig. 5 (b)). That is, when the operation pedal 10 is stepped on, the bucket blade edge position at that time is obtained, and the obtained position is set as the excavation start position at the time of this excavation.

Now, set the excavation start position P ₁ with respect to the boom rotation point A (X ₁ ,
Y ₁ ), this position (X ₁ , Y ₁ ) can be calculated from the boom angle α ₁ , the arm angle β ₁ and the bucket angle γ ₁ at the time when the pedal 10 is stepped on by the following expression X ₁ = l ₁ cosα ₁ + l ₂ cos (α ₁ + β ₁ ) + l ₃ cos (α ₁ + β ₁ + γ ₁ ) Y ₁ = l ₁ sin α ₁ + l ₂ sin (α ₁ + β ₁ ) + l ₃ sin (α ₁ + β ₁ + γ ₁ ) …… (1 ) Can be obtained by In this embodiment, the positions of the plurality of set points P _{1 to} P _n with respect to the vehicle (boom rotation point A) are not all obtained at the start of excavation.
In each unit section, the next target position is calculated each time to reduce the storage capacity and to easily cope with the change of the trajectory.

When the start of excavation is designated, the coordinates of the next target position P ₂ advanced by a unit angle Δψ on the excavation locus determined according to the excavation start position are obtained. Moreover, since the attitude of the bucket is also definite depending on the target position P _2, boom angle alpha ₂ in the target position P _2, the arm angle beta ₂ and the bucket angle gamma ₂ can be determined uniquely. The target angle α ₂ of these work machines,
When β ₂ and γ ₂ are determined, the deviation from the current actual angle of each working machine is taken to obtain the target rotation angles Δα, Δβ of each working machine for moving the bucket blade edge to the point P ₂ . Δ
γ can be determined.

FIG. 6 is for explaining the calculation for obtaining Δα, Δβ, and Δγ, where ψ ₁ is the angle formed by the horizontal line and the line segment OD, and w ₁ is the line segment CD and the line segment at the excavation start point P _1. The angle formed by OD and w ₂ is the angle formed by the line segment CD and the line segment OD at the next target position P ₂ .

When the coordinates of P ₂ are (X ₂ , Y ₂ ), X ₂ = l ₁ cos (α ₁ + Δα) + l ₂ cos (α ₁ + β ₁ + Δα + Δβ) + l ₃ cos (α ₁ + β ₁ + γ ₁ + Δα + Δβ + Δγ) ≈X ₁ + Y ₁ Δα + {l ₂ cos (α ₁ + β ₁ ) + l ₃ cos (α ₁ + β ₁ + γ ₁ )} Δ
β + l ₃ cos (α ₁ + β ₁ + γ ₁ ) Δγ (2), and X ₂ can also be expressed as X ₂ = X ₁ + R · Δψ · sin (ψ ₁ + 0.5Δψ) …… (3) Yes, l ₂ cos (α ₁ + in equation (2) above
β ₁ ) + l ₃ cos (α ₁ + β ₁ + γ ₁ ) = l _a , l ₃ cos (α <sub>1
+ Β 1 + γ 1) ·</sub> Δγ = When l _b, the (2),
_{(3) Y 1 · Δα +} l a Δβ + l b Δγ = -R · Δψ · sin (ψ 1 + 0.5Δψ) ...... (4) is established from the equation.

Similarly, Y ₂ = Y ₁ + X ₁ Δα − {l ₂ sin (α ₁ + β ₁ ) l ₃ sin (α ₁ + β ₁ + γ ₁ )} Δβ −l ₃ sin (α ₁ + β ₁ + γ ₁ ) Δγ ...... _{(5) = Y 1 -R ·} Δψ · cos (ψ 1 + 0.5Δψ) ...... (6) is satisfied, the equation (5) _{l 2 sin (α 1 + β} 1) + l 3 sin
(Α ₁ + β ₁ + γ ₁ ) = l _c , l ₃ sin (α ₁ + β ₁ +
When γ ₁₎ Δγ = l _d, above (5), (6) X 1 Δα + l c Δβ + l d Δγ = RΔψ · cos (ψ 1 + 0.5Δψ) ...... (7) is established from the equation.

Further, ψ ₁ + w ₁ = α ₁ + β ₁ + γ ₁ −π / 2 (8) ψ ₁ + Δψ + w ₂ = α ₁ + β ₁ + γ ₁ + Δα + Δβ + Δγ −π / 2 ...... (9) Therefore, these ( From Equations 8) and (9), w ₂ −w ₁ = Δα + Δβ + Δγ−Δψ (10) is established.

In equations (4), (7), and (10), Δα, Δβ, Δ
Since all except γ are specified, these (4), (7),
By solving the equation (10), the excavation start point P ₁ to the next target point
The rotation angles Δα, Δβ, and Δγ of each work machine for moving the bucket blade edge to P ₂ can be obtained.

The flow rate command for each working machine cylinder is determined based on the rotation angles Δα, Δβ, and Δγ thus obtained. At this time, the sum Q _s (= Q) of the pressure oil flow rates supplied to each working machine is determined.
_bm + Q _am + Q _bt ; Q _bm , flow rate for boom, Q _am , flow rate for arm, Q _bt , flow rate for bucket) is the discharge flow rate of the pump at that time, and determines the flow rate command for each work machine . That is, the rotation angles Δα, Δβ,
The flow rate distribution ratio required by each working machine is determined based on Δγ, and the pump at the maximum output is calculated from the constant horsepower relationship between the pump flow rate Q and the pump pressure P shown in FIG. 7 and the actual pump pressure P _d at the present time. The flow rate _Qd is obtained, and the flow rate command value for each working machine is determined by distributing this pump flow rate _Qd by the determined distribution ratio. Further, at this time, the boom, the arm, and the bucket simultaneously move to the target angles α ₂ , β ₂ ,
To reach γ ₂ , boom angle, arm angle,
The actual flow rate supplied to the square working machine is obtained based on the bucket angle, and the distribution ratio is adjusted as needed based on the calculated actual flow rate. The excavation for each unit section ends when the arm reaches the target angle β ₂ , and when the arm angle reaches the target value β ₂ , the control for the next section is performed. In the next section as well, in the same way as above, first, the target position of the bucket blade edge
P ₃ and the bucket attitude angle ε ₃ are determined, and the rotation angles Δα, Δβ, and Δγ are determined based on these determined values.
The flow rate command for each work machine is determined by the flow rate distribution corresponding to Δβ and Δγ. When the arm reaches the target angle β ₃ , the control of this section ends, and the control proceeds to the next section. By repeatedly executing such control up to the end point P _n , the bucket blade tip is moved from the initial position P ₁ (α ₁ , β ₁ , γ ₁ ) to the target position on the arc locus ... P _{8 as shown in FIG.}
(Α ₈ , β ₈ , γ ₈ ) ... P ₁₅ (α ₁₅ , β ₁₅ , γ ₁₅ ) ... P
It moves along ₂₀ (α ₂₀ , β ₂₀ , γ ₂₀ ) (FIG. 5 (C)).

FIG. 9 shows a conceptual configuration of the arithmetic control. That is, in this automatic excavation, the coordinate position of the next target point is calculated at the beginning of each unit section, and the actual flow rate value is fed back to the flow rate command obtained from these target positions at an appropriate cycle. The flow rate command to the machine is corrected at any time so that the bucket can move accurately on the excavation trajectory set in the proper posture.

When the operation pedal 10 is returned during excavation, the flow rate command for each work machine is set to zero and each work machine is immediately stopped unless manual operation is performed by the operation levers 11 and 12. .

Also, if a command from the manual levers 11 and 12 is input during automatic excavation, the manual one is given priority for safety and the automatic excavation is restarted from the point where the lever operation was stopped. .

By the way, during the automatic excavation, the load is detected by detecting the working machine pump pressure, and two different set values C ₁ and C ₂ are set for this pump pressure as shown in FIG. Set value C ₁ should be a little smaller than the relief pressure,
The set value C ₂ is smaller than C ₁ by several to several 10 kg / cm ² . Then, during the automatic excavation, when the working machine pump pressure becomes larger than the set value C ₁ , the pump pressure is set to the set value C ₂
I try to raise the boom until it becomes below. This boom raising stops when the load reaches the set value C ₂ . At the time of this boom raising operation, regarding the arm and the bucket, both of the target angles Δβ calculated at the beginning of this section,
Rotate until reaching Δγ. Then stop the boom and set the bucket and arm to the desired angle Δ as described above.
The bucket blade edge position rotated by γ and Δβ is calculated, and the automatic excavation of the remaining section is restarted using the calculated position as the restart point. Specifically, as shown in FIG. 11, when the restart point after the boom is raised is P _g , the target position is calculated with the point P _g as the start point of the excavation section this time. Therefore, the center of the arcuate locus moves from the point O to O ′, and the locus after restarting is a locus in which the locus at the beginning of excavation is shifted upward by an amount corresponding to the boom raising amount. In this way, even after restarting, the automatic excavation is performed so that the virtual line OD is rotated by the unit angle Δφ about the point O ′.

It is considered that the amount of excavated soil is smaller when the trajectory is corrected as described above than when the trajectory is not corrected. Therefore, in this embodiment, the amount of excavated soil is crossed in FIG. 12 so that the amount of excavated soil is always constant. A horizontal excavation section I indicated by hatching is provided.

That is, assuming that the excavation section has advanced to the intermediate point after the trajectory correction by boom raising, if the bucket blade edge cuts up to the present point and the horizontal excavation section is not provided, the bucket blade edge will attempt to cut out thereafter. Calculate the volume VB and. If the excavation volume based on the reference trajectory when the trajectory is not corrected is V and the volume of the horizontal excavation section I is VI, the volume V can also be obtained in advance, and thus VI can be determined by the following equation.

VI = V- (VA + VB) When VI is determined in this way, the excavation depth d can be determined from the bucket blade edge position at this time, so the horizontal excavation section length l = (V / d) must be determined. You can Then, the horizontal excavation section having the calculated length l is inserted in front of the remaining section so that the excavated soil amount is always constant.

Further, in this case, the end of the excavation is detected based on the pump pressure value of the hydraulic pump, and the time when the pump pressure of the hydraulic pump exceeds the predetermined value in the latter half of the excavation where the excavation section has advanced to some extent. We recognize that it is the end of excavation. After this recognition, the boom is raised and the bucket is tilted to the horizontal state to finish excavation. In this way, since the end of excavation is detected by detecting the load by the hydraulic pump pressure, it is possible to prevent waste excavation. After the completion of this excavation, the mode shifts to the bucket horizontal holding mode in which the bucket inclination is always kept horizontal (FIG. 5 (d)). In this bucket horizontal holding mode, the bucket angle γ is set so that α + β + γ = 3 / 2π is satisfied in response to input commands from the boom operation lever and the arm operation lever.
The upper surface of the bucket is always kept horizontal by automatic control. Further, in the horizontal holding mode, the operation of the automatic excavation operation pedal 10 is invalid. By such control, the load is prevented from being spilled, and the operation during the loading work is simplified (the bucket operation is unnecessary).

The automatic excavation mode is released when the bucket is rotated toward the dump side by a predetermined amount or more in the bucket horizontal holding mode. That is, when the operator rotates the bucket toward the dump side by a predetermined amount or more for soil removal during the bucket holding mode, the automatic excavation mode is released (FIG. 5 (e)).

In this excavation, the bucket is not always in the optimum posture at the start of excavation, but in such a case, the bucket posture is not suddenly corrected to the optimum posture by the next section, but an appropriate number. Sections are provided, and the angle is gradually corrected to an optimum angle between these sections.

FIG. 1 shows an example of a control configuration for realizing the above-mentioned functions. Whether or not the automatic excavation mode designation pedal 10 is depressed is detected by the pedal operation detector 17, and the detection signal is input to the controller 20. . The operation direction and the operation amount of the bucket boom operating lever 11 is detected by a lever position detector 13 and 15, respectively from these detectors 13 and 15 to the bucket rotation command _r and the boom rotation command _r switches 30 and 32 s Is entered. Further, the operation direction and operation amount of the arm operation lever 12 are detected by the lever position detector 14, and an arm rotation command _r which is a detection signal thereof is detected.
Is input to switch 31. The command signals _{r 1} , _{r 2} , _{r 3 from} these operating levers 11.12 are also input to the controller 20.

The switches 30.31 and 32 perform the switching operation based on the switching control signals SL ₁ , SL ₂ and SL ₃ input from the controller 20, respectively, and the command signals _{c 1} , _{c 2} , Command signal for manual excavation input from _c and lever position detector 13.14.15
_{r 1} , _{r 2} and _{r 3} are selectively switched.

The bucket control system 40 includes an angle sensor 41 that detects a bucket angle γ, a differentiator 42 that differentiates the bucket angle γ to detect an actual bucket rotation speed, and a signal that indicates a target value and an actual bucket rotation speed. And a flow rate control valve 44 that supplies pressure oil having a flow rate according to the deviation signal to the bucket cylinder 4 so that the deviation signal from the addition point 43 becomes zero.

Similarly, the arm control system 50 and the boom control system 60 have an angle sensor 51.61, a differentiator 52.62, an addition point 53.63, and a flow rate control valve 54.64, respectively, in the same manner as the bucket control system 40, so as to match the command value. Controls the rotation of the arm and boom.

The bucket angle r. Arm angle. Detected by the angle sensor 41.51.61 of these flow rate control systems. β. The boom angle α is also input to the controller 20. Further, the pump pressure of the work implement pump (not shown) is detected by the hydraulic pressure sensor 70, and the detected pressure is input to the controller 20.

The operation of this configuration will be described with reference to the flowchart shown in FIG. When the operation pedal 10 is depressed, this is detected by the pedal operation detector 17, this detection signal is input to the controller 20, and the controller 20 starts control in the automatic excavation mode (step 100).

When the automatic mode is started, the controller 20 outputs the output .gamma .. of the angle sensor 41.51.61. β. Based on α, the bucket blade tip position P ₁ at the start time is obtained (see the equation (1)). Subsequently, the controller 20 substitutes the calculated excavation start position P ₁ into the calculation program created from the equations (4), (7) and (10), and the bucket determines the bucket attitude ε ₂ at the next target position P ₂ . The required rotation angle Δα. Of each work machine that moves the bucket blade edge from P ₁ to P ₂ . Δβ. Calculate Δγ (step 110). Next, the controller 20 determines these rotation angles Δα. Δβ. Determining the distribution ratio of oil to be supplied to the respective working machines from [Delta] [gamma] (step 120), further obtains the pump pressure P _d from the output of the oil pressure sensor 70 at this time, the pump pressure from the relationship shown in FIG. 7 P _d command signal for each working machine by seeking the pump flow rate Q _d at the maximum output corresponding, the pump flow rate Q _d distributing with a said distribution ratio that the _{c. c.}
asked to _c, the finger command signal _{c. c.} a _c switch 32.31.
Output to 30 (step 130). When the automatic mode is selected, each contact of the switch 30.31.32 is switched to the controller 20 side by the switching control signals SL ₁ , SL ₂ and SL ₃ of the controller 20, and the command signal _c from the controller 20. . _{c. c} is input to the boom control system 60. arm control system 50. bucket control system 40 via these switches 32.31.30.

In the next step 140, the controller 20 determines whether or not the pedal 10 is stepped on the basis of the output of the pedal operation detector 17, and when the return of the pedal 10 is detected, a designated signal to be input to each flow rate control system _{c. c.} immediately to zero _c (step 150). Also, the manual command by the operation of the operation lever 11.12 in step 160 _{r. R. R} is determined whether or not the input, giving priority to manual commands, if it has been entered (step 170). That is, when a manual command is input, the command signal from the operation lever side is switched to the corresponding flow rate by switching the switch of the working machine corresponding to the input manual command among the switches 30.31.32 to the operation lever side. Supply it to the control system.

Further, in step 180, it is determined whether or not the pump pressure detected by the hydraulic pressure sensor 70 exceeds the set value C ₁ (step 180). The judgment is "YES" at the beginning of excavation.
Therefore, the procedure normally moves to step 200.

Thus, the command signal _c from the controller 20 in accordance with the operation mode of the operation pedal 10 operation lever 11.12. _{C. C}
(Zero when the operation pedal is off) or manual lever 1
Command signal _r from 1.12. _R. Flow control _{system r} corresponding
Input to 60.40.50, which causes the bucket, arm, and boom to rotate. The controller 20 is the angle sensor 4
Based on the output of 1.51.61, the actual flow rate of oil supplied to each cylinder 8.7.6 is obtained, and the distribution ratio is sequentially adjusted according to these actual flow rate values (step 200).

Next, the controller 20 determines whether or not the arm has reached the target angle β ₂ based on the detection output β of the angle sensor 51 (step 210). If the target angle β ₂ has not been reached, the process returns to step 120, The same control as above is repeated. If the arm reaches the target angle β ₂ , it is then determined whether or not the excavation has reached the intermediate point (step 220). If it is not the intermediate point, the process returns to step 110 and the bucket blade tip position is changed to the next target position P. _The arithmetic control to move to ₃ is performed in the same manner as above. Similarly, the bucket blade edge is moved along the target positions P ₄ , P _5, ... Until the intermediate point is determined in step 220.

By the way, if the pump pressure detected by the hydraulic pressure sensor 70 exceeds the set value C ₁ during such automatic excavation (step 180), the controller 20 causes the controller 20 to operate as shown in FIGS.
As shown in the figure, the trajectory is corrected by raising the boom until the pump pressure drops to the set value C ₂ . (Step
190). When the boom is raised, the arm and the bucket rotate at the rotation angle Δβ. Rotate by Δγ, and stop the boom when the pump pressure drops to the set value C ₂ . After that, the automatic excavation is restarted with this point as a restart point. In this way, if the excavation is completed up to the intermediate point (step 220), it is determined whether or not the trajectory is corrected (step 230). If the trajectory is corrected, use the previous FIG. The horizontal excavation section described above is added, and the work machine is driven by the horizontal excavation (step 240). That is, the controller 20 stores the bucket blade edge position calculated from the output of the angle sensor 41.51.61 at each time point, and the controller 20 cuts with the bucket blade edge from the beginning of excavation to the intermediate point based on the stored data. Calculate the volume VA, and then the volume of the remaining section
VB is calculated from the preset reference movement locus and the current bucket blade edge position. Then, the volume VI of the horizontal excavation section I is obtained by subtracting the added value of these excavation volumes VA and VB from the excavation volume V without trajectory correction, and the volume V is calculated from the output of the angle sensor 41.51.61. The section length l is determined by dividing by the excavation depth d.

When this horizontal excavation is completed, it is judged whether or not the excavation is completed (step 260). If it is not completed, step 110
Return to and excavate the remaining section. In this case, the time when the excavation section is in the latter half and the output value of the hydraulic pressure sensor 70 exceeds a predetermined value is detected as the end of excavation. When a manual command is input during automatic excavation, the controller 20 returns the procedure to step 110 when the manual command is stopped, and the switch corresponding to the work machine to which the manual command was input. To the controller 20 side,
All work machines are re-driven by a command signal from the controller 20 with the point where the manual operation is stopped as a restart point.

When the end of excavation is determined in step 260, the controller 20 shifts to the bucket horizontal holding mode for horizontally controlling the bucket tilt angle (step 270). In this horizontal holding mode, the switch 31.32 is switched to the manual lever 11.12 side, the switch 30 is directly connected to the controller 20 side, and the boom and arm are driven according to the manual command. With respect to the bucket, the controller 20 outputs the command signal _c so as to satisfy α + β + γ = 3 / 2π so that the bucket tilt angle is always horizontal even if the boom and the arm are arbitrarily manually operated. If the bucket is rotated to the dump side by a predetermined angle or more during the bucket horizontal holding mode, the controller 20 cancels the automatic mode (step 280).

In the above embodiment, when the pump pressure exceeds a predetermined set value in the latter half of the excavation, that is, when the load applied to the working machine exceeds a certain value, the excavation is terminated, and the procedure is followed by the bucket horizontal holding mode. However, the number of divided sections may be simply counted, and when the excavation of a predetermined number of sections is completed, the excavation may be completed.Furthermore, the absolute attitude of the bucket is determined, and the bucket absolute attitude is almost horizontal. The approaching may be determined to be the end of excavation.

Further, in the above embodiment, when correcting the trajectory due to the boom rising,
Both the bucket and the arm rotate until they reach the target angle, and the bucket blade tip point at that time is set as the restart point, but the bucket blade tip position at the time when the arm reaches the target angle after the boom stops rising is reset. It may be used as a starting point.

Further, the horizontal excavation may be performed not only at the intermediate point but also at an arbitrary excavation point, and the horizontal excavation may be appropriately added even when the trajectory correction by the boom rise is not performed.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform efficient full-automatic excavation control along an excavation locus by a simple operation of only automatic mode designating means such as an operation pedal and an operation button. At the same time, the excavation resistance is low during this excavation, there is no load spillage, and the work machine is controlled to make effective use of the pump output, so work efficiency can be improved and excavation time can be shortened. it can.

Further, since the set locus is corrected according to the actual load, relief loss is suitably reduced and at the same time,
Since the horizontal excavation section having the length corresponding to the actual excavation volume is provided, the excavated soil volume can be made uniform at all times.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an external view of a power shovel, FIG. 3 is a diagram used to define the length and angle of a working machine, and FIG. FIG. 5 is a diagram for explaining a method of setting an automatic excavation locus, FIG. 5 is a process diagram for explaining an automatic excavation procedure, and FIG. 6 is Δα. Δβ. FIG. 7 is a diagram used to explain a method for obtaining Δγ, FIG. 7 is a diagram showing a constant horsepower curve, FIG. 8 is a diagram showing an example of movement of each working machine during automatic excavation, and FIG. 9 is calculation of a target position. And FIG. 10 is a diagram conceptually showing the output mode of the command signal, FIG. 10 is a diagram for explaining the relationship between the pump pressure and the set value, FIG. 11 is a diagram showing changes in the trajectory when the boom is raised, and FIG. FIG. 13 is a diagram for explaining an example of excavation in which a horizontal excavation section is provided, and FIG. 13 is a flowchart used for explaining the operation of the controller of FIG. 1 ... Crawler track, 2 ... Upper swing body, 3 ... Boom, 4 ...
Arm, 5 ... Bucket, 6 ... Boom cylinder, 7 ...
... Arm cylinder, 8 ... Bucket cylinder, 10 ... Automatic excavation operation pedal, 11 ... Bucket boom operation lever, 12 ... Arm rotation operation lever, 13.14.15 ... Lever position detector, 17 ... Pedal Operation detector, 20 …… Controller, 30.31.32 …… Switch, 40 …… Bucket control system,
41.51.61 …… Angle sensor, 42.52.62 …… Differentiator, 43.53.
63 …… Addition point, 44.54.64 …… Flow control valve, 50 …… Arm control system, 60 …… Boom control system, 70 …… Hydraulic sensor.

Claims (3)

[Claims] 1. A reference movement locus of a bucket blade tip approximated by a plurality of points and respective bucket postures when the bucket blade tip is positioned at these plurality of points are preset, and the plurality of points are set from a designated excavation start position. A power shovel that automatically drives the bucket, the arm, and the boom in each excavation section unit divided by the plurality of points so that the bucket blade edge moves along the plurality of points and the bucket takes the set posture at the plurality of points. In the work implement control device, the load detection means for detecting the load, and when the detection value of the load detection means during the automatic excavation becomes equal to or more than the first set value, the detected value is smaller than the first set value. The boom is driven up to the second set value, and the raised bucket edge position is restarted to restart the automatic excavation of the remaining section. Excavators of the work machine control apparatus comprising and. 2. The work implement control device for a power shovel according to claim 1, wherein the first set value is a value slightly smaller than the relief pressure. 3. A reference movement locus of a bucket blade edge approximated by a plurality of points and respective bucket postures when the bucket blade edge is located at these plurality of points are preset, and the plurality of points are set from a designated excavation start position. A power shovel that automatically drives the bucket, the arm, and the boom in each excavation section unit divided by the plurality of points so that the bucket blade edge moves along the plurality of points and the bucket takes the set posture at the plurality of points. In the work implement control device, the load detection means for detecting the load, and when the detection value of the load detection means during the automatic excavation becomes equal to or more than the first set value, the detected value is smaller than the first set value. The boom is driven to rise to the second set value, and the automatic excavation of the remaining section is restarted with the raised bucket blade edge position as the restart point. First means for resuming excavation, and when the automatic excavation ends up to a predetermined section after restarting the automatic excavation, the excavation volume from the beginning of excavation to the predetermined section and the excavation volume in the remaining section are added to raise the boom. Second means for subtracting the additional value from the excavation volume based on the reference movement trajectory when the driving is not performed, and adding a section for performing linear excavation for the volume corresponding to the subtracted value in front of the remaining section. Work excavator work equipment control device.