JPS61200226A - Position control device for power shovel - Google Patents

Abstract

PURPOSE:To facilitate linear excavation and slope excavation through provision of arbitrary locus of the edge point of a bucket, by providing a position control part which comprises a speed instruction part, a coordinate conversion part, a boom cylinder, an arm cylinder, and the flow rate control systems of a bucket cylinder. CONSTITUTION:A position control device comprises a speed instruction part 30, a coordinate conversion part 40, a boom cylinder 4, an arm cylinder 5, and flow rate control systems 50, 60, and 70 of a bucket cylinder 6. In the case of horizontal excavation, a lever 31 of the speed instruction part 30 is brought into a neutral position in relation to a rotation direction and a direction (y), and only in the case of a direction (x), horizontal excavation is performed in a state to incline a lever 31. If the lever 31 is inclined only in the direction (y), the edge point of the bucket 3 is moved in a vertical direction. In the case of slope excavation, if the lever 31 is inclined in the directions (x) and (y), the edge point of the bucket 3 is linearly moved at an angle, determined by a speed ratio depending upon an inclination direction, as an angle 0 to earth is left to be kept at a constant value.

Description

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

[Conventional technology]

Generally, a hydraulic power excavator has a poom 1 as shown in Fig. 5. Arm 2. Bucket 3 and boom cylinder 4 that drives them. Arm cylinder 5゜Bucket cylinder 6
Each of the cylinders 4 to 6 is manually operated by a control lever (not shown) K provided within the operating chamber. Then, the operator manually controls the attitude of the working machine and sets the bucket position. Therefore, advanced skills are required of the operator.

In particular, grading work using a bucket, that is, controlling the parallel movement of the bucket, is extremely difficult, and almost impossible in grading work on slopes.

FIG. 6 shows one conventional technique for solving such problems.

In this configuration, focusing on the tip point C of the arm 2 (rotation fulcrum of the bucket 30), each setting device 10 and 11 calculates the velocity component X in the X-axis and y-axis directions at the end point C.

and Yc as target value Xc and @ref K is set to be set as Yc.

Now, the positions of each part of the working machine are defined as shown in FIG. That is, origin 0 (0, 0): rotation fulcrum point B (zb, y
b): Rotation fulcrum point C of arm 2 (“c,!/c): Rotation fulcrum point D (xd, ya) of bucket 3: Point of cutting edge of bucket 3. Here, X axis: Point o , B, C, and D and the vehicle turning plane including point 0. Y-axis: A straight line passing through point O and perpendicular to the vehicle turning plane. In FIG. 7, Ll: point 0. Length between B L2: Length between points B and C, length between two points C and D α: Angle formed by line segment OB with respect to the y-axis β Formation of line segment BC with respect to the extension line of two line segments OB Angle γ: Angle (cutting edge angle) formed by the line segment CD with respect to the extension line of the line segment BC. Defined as above, the coordinates of point C ("c,
yc) is expressed as follows.

3: c=L, sin α+L2 sin (α+β) --
−・−・(1) yC=L, cosα+L, cos(α+
β)・・・・・・・・・(2) Differentiate these equations (1) and (2) with respect to time to find the velocity component in the become that way.

;. =L, acosα+L, (&10k) cos (α
+β)...(3) 31c=-L1asinα-L2(C1+79)s
in (α+β)... (4) where h: temporal change in angle α (rotating speed of poom 1) λ
: Temporal change in angle β (rotational speed V of arm 2).

If we solve these equations (3) and (4) for &, we get the following equation: ``c + : Mi to obtain /c, λ
is required.

(5) That is, in the coordinate conversion section 13 in FIG. 6, each setting device 10
The angular velocity command α of the poom 10 and the angular velocity command β of the arm 2 are outputted by performing the conversion shown in the above equation (5) based on the speed fingers APXc and Yc of the arm tip points inputted from 11 and 11, respectively.

Then, each angular velocity command α, β derived by this coordinate conversion unit 13 and the bucket angular velocity command γ directly set by the setting device ]2 are added to each addition point 14°15 and 1
6, respectively. Each addition point 14, 15 and 1
6, the respective input angular velocity commands α,
β and γ and each work equipment (boom).

Deviations from the angular velocity detection values &, λ, and n of each work machine derived from the detection outputs of the angle sensors 19 installed on the arms and buckets (, ref, ”), <Table”-;
i) and (, +1 ref , ++ >, respectively) and input the derived deviations to the respective flow rate control devices 17 .

Each flow rate control device 17 controls the pressure oil supply flow rate to the boom cylinder application, the arm cylinder 21, and the bucket cylinder n so that each of these deviations becomes zero, thereby adjusting the rotation angle α of each work machine at each point in time. , β and γ.

In this way, in this conventional device, each work equipment boom, arm, The movement of the buckets is controlled individually.

[Problem that the invention seeks to solve]

However, according to this prior art, although it is easy to move the arm end point in parallel, parallel movement of the bucket end point still relies heavily on the skill of the operator. For example, when performing horizontal excavation, unless the operator operates the setting device 12 in addition to the setting device 10, the locus of the bucket cutting edge point will not be horizontal.

Also, when excavating a slope, is it desirable to keep the bucket ground angle θ (see Fig. 7) constant? The positions taken by arm 2 and bucket 3 (α.

β, γ), so the operator needs quite advanced skills to keep these values constant during excavation.

This invention was made in view of these circumstances.
The present invention aims to provide a position control device for a power shovel that can perform tasks such as straight line excavation, slope excavation, etc. with high precision and simple operation.

[Means and effects for solving the problem] In this invention, we focus on the bucket tip point (,rd, yd), give it as speed command values in the X-axis and y-axis directions of the bucket tip point, and calculate these command values. Based on the detected values of the actual angles of the boom, arm, and bucket, target values of boom rotation speed α, arm rotation speed β, and bucket rotation speed γ are derived, and each of these derived target values is The flow rate of pressure oil supplied to the boom cylinder, arm cylinder, and bucket cylinder is controlled accordingly. In addition, the bucket-to-ground angular velocity station -
Instead of θ, the rotation speed of the bucket can also be used as the command value.

〔Example〕

FIG. 1 shows an embodiment of the present invention.

In Figure 1, on the speed command unit side, the bucket cutting edge point DO
Velocity components in the x-axis and y-axis directions, r, d.

It commands the departure ef and the bucket ground angular velocity -δref (see FIG. 7). If the speed control unit I is configured with an electric lever as shown in the figure, it can output xd and yd according to the inclination of the lever in the X-axis direction and the y-axis direction, and furthermore, it can output the rotation of the lever itself. It is possible to output 10 according to (torsion).

This electric lever is installed so that the lever 31 is in the horizontal direction, so that the movement direction of each work machine and the lever 31 are
The moving directions of 1 actually match. When the lever 31 is in the neutral position, each output becomes zero. The three command parts -ref " ref 'd, 'ld and -θ designated on the speed command part side are input to the coordinate transformation part 40.

Here, the coordinates of the tip of the bucket 3 (Xd.

ya) is expressed by the following equation based on the positional relationship shown in FIG.

xd2 LISI+1α+L2sir+ (α+β)+L
3SIJ1 (α+β+γ)・・・・・・(6) ,! / d -” L + C06α 1■ノ, t, w
(α+β)+L 8. N6(α+β+γ)−・・・
(The force and the angle between the bucket 3 and the x-axis, that is, the angle θ relative to the ground, are given by the following formula from FIG. 7).

θ=−π−(α+β+γ) ・・・・・・
(8) Differentiate these equations (6), (7), and (8) with respect to time to obtain the velocity component Jl'd in the X-axis and y-axis directions at the point.

yd and the bucket ground angular velocity −〇 are calculated as follows.

11, (Go (α + β) + L, 0) S (α + β + γ) L
t 5In(α+β)−L3sin(α+β+γ) When this equation (9) is solved for α, β, and γ, the following equation is obtained.

−L, ■(α+β) L, cosα+L t ” (α+β) −L, ■α (However, trace β←0) This (10 formula is the basic formula of this embodiment, and the coordinate transformation unit 40 in Figure @1 Command signal input from the speed command section
d, yd and −〇 and the actual angle α of each work machine,
Based on β and γ, coordinate transformation is performed according to equation (10) above, and boom 1. Erno@ref Angular velocity command α of each of 2 and bucket 3.

Output β and rref. for this conversion'
Examples of the ref configuration include a configuration using a microcomputer, or a hardware configuration using a trigonometric function generator, an arithmetic unit, and the like.

Angular velocity fingers 4a'' of each working machine (boom 1, arm 2, bucket 3) output from the coordinate conversion unit 40.

β and rref each drive each work machine.”
ref is sent to the supply flow rate control system (equipment) of each cylinder, 60 and 70, and between the supply flow rate control systems 60 and 70, the flow rate of pressure oil supplied to each cylinder is controlled.

For example, the boom angular velocity command α is sent to the supply flow rate control system of the boom cylinder 4 as the target value of the boom rotation speed α, and at the addition point 51, the difference between the α target value meter 1 and the actual boom rotation speed α is is required. That is, between the boom cylinder control system, the angle detector 52 detects the boom angle α relative to the vehicle body using a potentiometer (not shown) attached to the rotation fulcrum O of the boom 1, and the angular velocity calculator 53 detects this detection. Differentiate the angle α to find the actual rotational speed α
is calculated, this value α is fed back to the addition point 61, and “r
ef”. The deviation (α − α) calculated at the addition point 51 is input to the compensator 64, and the compensator 64 and the electro-hydraulic converter 6
5, pressure oil is supplied to the boom cylinder 4 so that the deviation (α - α) becomes zero.

The supply flow rate control systems 60 and 70 of the arm cylinder 5 and bucket cylinder 6 are also configured in the same manner as the supply flow rate control system of the boom cylinder 4, and the arm angular velocity command β and baguette angular velocity command inputted thereto, respectively. The flow rate control is performed in the same manner as described above, using each target value.

In the configuration shown in FIG. 1, the bucket ground angle θ
When performing horizontal excavation while keeping the angle θ constant, if the lever 31 in the speed command unit 30 is set neutral in the rotating direction and the y direction, and the lever 31 is tilted only in the The cutting edge point can be moved horizontally. Furthermore, by tilting the lever 31 only in the y direction, the cutting edge point of the bucket 3 can be moved in the vertical direction while keeping the ground angle θ constant.

Furthermore, when excavating a slope, move the lever 31 in the X and Y directions.
By tilting the bucket 3 in both directions, the tip of the bucket 3 can be linearly moved at an angle determined by the speed ratio corresponding to the tilt direction while keeping the ground angle θ constant.

By the way, in the configuration shown in FIG. 1 above, the command values directly commanded by the operator include the excavation angle ψ and the bucket excavation angle instead of the velocity components Z a'' and y a'' of the bucket cutting edge point in the X-axis and y-axis directions. The speed υref may also be used. In this case, these values “d, yd
, ψ and υ as shown in the following equation, the above (11) is applied before the coordinate transformation unit 40 as shown in FIG.
If the conversion section 32 is provided to perform conversion according to the formula, "d + ef yd and -0" are input to the coordinate conversion section 40 as described above, and the same arithmetic control as described above is performed from then on. For example, a function equivalent to that shown in FIG. 1 can be achieved.

FIG. 3 shows another embodiment of the invention.

In the embodiment shown in FIG. 3, as in the previous embodiment, attention is paid to the point of the cutting edge of the bucket 3, and the speed command section Akara shows the velocity components of the point of the bucket's cutting edge in the X-axis direction and the y-axis direction. d
, 3'd are output, but in this embodiment, the bucket angular velocity n is set as another command element in the speed command section A. Of these three command signals, "d" and "yd" are input to the coordinate conversion section 45.

Here, the coordinates (xd, ya) of the cutting edge point of the bucket 3 are expressed by the following equation as shown in the above (6) and (force equation).

xd=L, sLnα+L, sin (α+β)+Ls
=(α+β+r)-(6)3'd=L1"'α+L
2 × α + β) + L, − (α + β + γ) ・(7) Differentiate these equations (6) and (7) with time to find the velocity components in the X-axis and y-axis directions at the point −”d, yd and becomes as follows.

Solving this equation (12) for α and β gives the following equation L
11(α+β)-LsCoS(α+β+γ)1.1ao
aα+L−叡α+β)+L,■(d+β+γ)The coordinate conversion unit 45 in FIG.
, β, and γ, coordinate transformation according to the above equation (13) is performed, and angular velocity commands α and β of boom 1, ref, and arm 2 are output.

These angular velocity commands α and β are added to the addition points 51 and 61 of each flow control system as described above, and the deviations (α − α) and (β
-β), the poom 1 and the arm 2 are respectively driven.

On the other hand, the bucket angular velocity "rr" set for the speed setting section
ef is input to the addition point 71, and "r" is input to the addition point 71.
ef, the target value γ, the actual bucket angular velocity γ, and "r
The deviation (γ - γ) of ef'' is determined. Then, as before, the bucket 3 is driven so that this deviation (rref -2) becomes 07.

That is, in this embodiment, boom 1. Angular velocity command α of arm 2 and bucket 3
, β and ref, and these ref
' ref ' ref ' ref ' re
boom according to f angular velocity commands α, β and γ;
Make the arm and bucket drive.

L t a-s (α+β)-L3co8(α+β+γ
)L, cys(1+L2., (α+β)+Ls
ccs (α + β + γ)@3 According to the configuration shown in Figure 3, when performing horizontal excavation, for example, the lever 31 at the speed command unit is set neutral in the y direction and given constant rotation in the rotation direction. , by tilting at a constant angle with respect to the X direction, the point of the cutting edge of the bucket 3 can be moved in the horizontal direction. In this case, the ground angle θ is not constant. At this time, depending on the excavation conditions, bucket 3
may be fixed.

In this configuration, since pressure is applied to control the movement of the blade edge point of the bucket, a highly accurate locus of the blade edge point of the bucket can be obtained.

In addition, also in this embodiment, as shown in FIG.
Using the bucket excavation speed υ, excavation angle ψref, and bucket angular velocity γ as command values, the conversion unit 32 converts the command value υ and excavation angle ψ into velocity components 'ref xd and yd of the bucket cutting edge point in the X-axis and y-axis directions. Then, this converted value “d”,
yd and the bucket angular velocity γ may be input to the coordinate conversion unit 45.

In the above embodiment, an electric lever that can give commands regarding three elements with one lever is used as the speed setting means, but of course, a configuration using a normal three levers may also be adopted.

Further, in the above embodiment, the angular velocity of each working machine is determined by differential calculation, but a detector for detecting the angular velocity may be attached to each working machine.

〔Effect of the invention〕

As explained above, according to the present invention, an operator who wants to control the trajectory of the bucket cutting edge point can obtain an arbitrary trajectory of the bucket cutting edge point with a simple operation, which was previously considered difficult. Work such as direct excavation and slope excavation, which had previously been carried out, can now be carried out easily.

[Brief explanation of drawings]

FIG. 81 is a block diagram showing a first embodiment of the invention, FIG. 2 is a block diagram illustrating a modification of the first embodiment, and FIG. 3 is a block diagram showing a second embodiment of the invention. FIG. 4 is a block diagram for explaining the second embodiment, FIG. 5 is a diagram showing the configuration of a hydraulic power shovel, and FIG. 6 is a block diagram showing an example of the configuration of a conventional device. , FIG. 7 is an explanatory diagram for defining the coordinate positions, etc. of each part of the power shovel. 1...Boom, 2...Arm, 3...Bucket,
4...Boom cylinder, 5...Arm cylinder, 6
...Bucket cylinder, 13, 40, 45...
Coordinate conversion section, Shu, 35... Speed setting section, 50, 60
, 70... Supply flow rate control system, 51° Fig. 5 (0,0) Fig. 6

Claims (4)

[Claims] (1) An x-component speed setting means for setting a moving speed component of the bucket tip point in the x-axis direction using a plane including the boom, arm, and bucket as a coordinate plane, and a moving speed of the bucket tip point in the y-axis direction on the coordinate plane. Set the components y
component velocity setting means; ground angular velocity setting means for setting the angular velocity of the bucket with respect to the x-axis direction; angle detection means for detecting the boom angle, arm angle, and bucket angle; and the x-component; Based on each set value set by the y component and ground angular velocity setting means, and each detected value of the angle detection means, the boom rotation speed, arm rotation speed, and bucket rotation speed corresponding to the set values are determined. Respective coordinate conversion means that calculate and output each target value, and each flow control system that controls the flow rate of pressure oil supplied to the boom cylinder, arm cylinder, and bucket cylinder according to each target value derived by these coordinate conversion means, respectively. A power shovel position control device equipped with (2) The x-component and y-component speed setting means calculates moving speed components of the bucket cutting edge point in the x-axis and y-axis directions, respectively, based on the input excavation speed and excavation angle, and converts these calculated values into the x-axis and y-axis directions, respectively. The position control device for a power shovel according to claim 1, wherein the position control device for a power shovel is outputted to the coordinate conversion means as set values in the component and y-component speed setting means. (3) an x-component speed setting means for setting a moving speed component of the bucket cutting edge point in the x-axis direction using a plane including the boom, arm, and bucket as a coordinate plane; and a moving speed of the bucket cutting edge point in the y-axis direction in the coordinate plane. Set the components y
component speed setting means; bucket angular speed setting means for setting the rotating speed of the bucket; angle detection means for detecting the boom angle, arm angle, and bucket angle; and the x-component and y-component speed setting means, respectively. coordinate conversion means for calculating and outputting target values of boom rotation speed and arm rotation speed corresponding to the set values based on the set values set and the detected values of the angle detection means; and a flow rate control system that controls the flow rate of pressure oil supplied to the boom cylinder, arm cylinder, and bucket cylinder in accordance with each target value derived by the means and the bucket rotation speed set by the bucket angular speed setting means. Power excavator position control device. (4) The x-component and y-component speed setting means calculates moving speed components of the bucket cutting edge point in the x-axis and y-axis directions based on the input excavation speed and excavation angle, and converts these calculated values into the x-axis and y-axis directions, respectively. The position control device for a power shovel according to claim 3, wherein the position control device for a power shovel is outputted to the coordinate conversion means as set values in the component and y-component speed setting means.