JPH076212B2 - Position control device for power shovel - Google Patents

Description

The present invention relates to a position control device for a power shovel.

[Conventional technology]

Generally, a hydraulic excavator is equipped with a boom 1, an arm 2, a bucket 3 and a boom cylinder 4, an arm cylinder 5 and a bucket cylinder 6 for driving these as shown in FIG. It is manually operated by an operation lever (not shown) provided in the cab. Then, the operator manually controls the posture of the working machine to set the bucket position. Therefore, the operator is required to have a high level of skill. In particular, leveling work by a bucket, that is, parallel movement control of the bucket is extremely difficult, and is almost impossible in leveling work on a slope.

FIG. 6 shows one prior art for solving such a problem.

In this configuration, paying attention to the tip point C of the arm 2 (rotational fulcrum of the bucket 3), the velocity components _c and _c in the x-axis and y-axis directions at the point C at the setters 10 and 11 are set to target values. ^It is set as ^ref _c ▼ and ▲ ^ref _c ▼.

Now, the position of each part of the working machine is defined as shown in FIG. That is, origin 0 (0,0): rotation fulcrum point of boom 1 B (x _b , y _b ): rotation fulcrum point of arm 2 C (x _c , y _c ): rotation fulcrum point D of bucket 3 (X _d , y _d ): The cutting edge point of the bucket 3. Here, x-axis: a line of intersection between a plane including points 0, B, C and D and a vehicle turning surface including point 0 y-axis: a straight line passing through the point 0 and perpendicular to the vehicle turning surface. In Fig. 7, L ₁ : Length between points 0 and B L ₂ : Length between points B and C L ₃ : Length between points C and D α: Angle between line segment 0B and y axis β: angle formed by the line segment BC with respect to the extension line of the line segment 0B γ: angle formed by the line segment CD with respect to the extension line of the line segment BC (blade angle) With the above definition, the coordinates (x _c ,
y _c ) is expressed by the following equation.

x _c = L ₁ sin α + L ₂ sin (α + β) (1) y _c = L ₁ cos α + L ₂ cos (α + β) (2) These equations (1) and (2) are differentiated with respect to time, and x at the point C When the velocity components _{c 1} and _{c 2 in} the axial and y-axis directions are obtained, the following equation is obtained. _c = L ₁ cos α + L ₂ (+) cos (α + β) ......
(3) _c = -L ₁ sin α-L ₂ (+) sin (α + β)
(4) where: time change of the angle α (rotation speed of the boom 1): time change of the angle β (rotation speed of the arm 2).

By solving these equations (3) and (4), the following equations are obtained to obtain the desired values _{c 1} and _{c 2} .

That is, in the coordinate conversion unit 13 in FIG. 6, the speed command for the arm tip point input from each of the setters 10 and 11
By performing the conversion shown in the above equation (5) based on ^ref _c ▼ and ▲ ^ref _c ▼, the angular velocity command of the boom 1 is issued.
^{The ref} and the angular velocity command ^{ref of the} arm 2 are output.

Then, each angular velocity command derived by the coordinate conversion unit 13
^ref , ^ref and the bucket angular velocity command ^ref set directly by the setter 12 are input to the respective addition points 14, 15 and 16. At each of the addition points 14, 15 and 16, the angular velocity commands ^ref , ^ref and ^ref respectively inputted and derived from the respective detection outputs of the angle sensor 19 installed in each working machine (boom, arm, bucket) are derived. Angular velocity detection value of work machine, and deviation ( ^ref −), ( ^ref −
) And ( ^ref −) are respectively calculated, and the derived deviations are input to the respective flow rate control devices 17.

In each flow rate control device 17, by controlling the pressure oil supply flow rate to the boom cylinder 20, the arm cylinder 21 and the bucket cylinder 22 so that each of these deviations becomes zero,
The rotation angles α, β and γ of each working machine at each time point are determined.

As described above, in this conventional apparatus, the boom rotation calculated based on the moving speed ( _c , _c ) given the moving speed (X _c , Y _c ) of the arm tip point C and the rotating speed of the bucket as command values. The movement of each work implement boom, arm, and bucket is controlled by the speed, the arm rotation speed, and the directly specified rotation speed of the bucket.

[Problems to be solved by the invention]

However, according to this conventional technique, although the parallel movement of the arm front end point is easy, the parallel movement of the bucket front end point still largely depends on the operator's technique. For example, when performing horizontal excavation, if the operator does not operate the setter 12 in addition to the setter 10, the trajectory of the bucket blade tip will not be horizontal. Further, it is desirable to keep the bucket ground angle θ (see FIG. 7) constant during slope excavation.
Since it changes depending on the positions (α, β, γ) taken by the arm 2 and the bucket 3, the operator needs a considerably advanced technique to carry out excavation while keeping this constant.

The present invention has been made in view of such a situation,
An object of the present invention is to provide a position control device for a power shovel capable of performing operations such as direct excavation and slope excavation with high accuracy by a simple operation.

[Means and Actions for Solving Problems]

In the present invention, focusing on the bucket tip point (x _d , y _d ), the velocity components _{d 1} and _{d in} the x-axis and y-axis directions of the bucket tip point and the bucket ground angle − are given as command values, and these command values Based on the detected values of the actual angles of the boom, arm, and bucket, the respective target values of the boom rotation speed, the arm rotation speed, and the bucket rotation speed are derived, and the boom cylinders are respectively corresponding to the derived target values. , Control the flow rate of pressure oil supply to the arm cylinder and bucket cylinder. Note that the bucket rotation speed may be used as the command value instead of the bucket angular velocity minus the ground.

〔Example〕

 FIG. 1 shows an embodiment of the present invention.

In FIG. 1, the velocity command unit 30 has velocity components ▲ ^ref _d ▼, ▲ of the bucket blade tip point D in the x-axis direction and the y-axis direction.
command ^ref _d ▼ and bucket angular velocity- ^ref (see FIG. 7). If the speed command unit 30 is composed of an electric lever as shown, it is possible to output ▲ ^ref _d ▼, ▲ ^ref _d ▼ according to the inclination of the lever in the x-axis direction and the y-axis direction. It is possible to output ^-ref according to the rotation (torsion) of the lever itself. This electric lever 30
Is mounted so that the lever 31 is horizontal, so that the moving direction of each working machine and the moving direction of the lever 31 actually coincide with each other. If the lever 31 is neutral,
Each output becomes zero. Three command signal designated by the speed command portion _{^{30 ▲ ref d ▼, ▲ ref}} d ▼ and - ^ref is inputted to the coordinate transformation unit 40.

Here, the coordinates (x _d , y _d ) of the cutting edge point D of the bucket 3 are the seventh
From the positional relationship shown in the figure, the following equation is obtained.

x _d = L ₁ sin α + L ₂ sin (α + β) + L ₃ sin (α + β + γ)
_{...... (6) y d = L} 1 cosα + L 2 cos (α + β) + L 3 cos (α + β + γ)
.. (7) Further, the angle between the bucket 3 and the x-axis, that is, the ground angle .theta.

These equations (6), (7) and (8) are differentiated with respect to time, and the velocity components in the x-axis and y-axis directions at the point D are obtained.
_{When d} , _d and bucket angular velocity − are obtained, the following equation is obtained.

By solving the equation (9) for and, the following equation is obtained.

This expression (10) is the basic expression of the present embodiment, and the coordinate conversion unit 40 of FIG.
^{Based on ref} _d ▼, ▲ ^ref _d ▼ and − ^ref and the actual angles α, β and γ of each working machine, coordinate conversion according to the above equation (10) is performed, and the boom 1, arm 2 and bucket 3 are converted.
The respective angular velocity commands ^ref , ^ref and ^ref are output. As a configuration for this conversion, for example, a configuration using a microcomputer, or a hardware configuration using a trigonometric function generator, four arithmetic operations unit, etc. can be mentioned.

Each work machine output from the coordinate conversion unit 40 (boom 1, arm
2, angular velocity commands ^ref , ^ref and ^{ref of} bucket 3)
Are sent to the supply flow rate control systems 50, 60 and 70 of the respective cylinders that drive the respective work machines, and the flow rate of the pressure oil supplied to the respective cylinders is controlled in the respective supply flow rate control systems 50, 60 and 70.

For example, the boom angular velocity command ^ref is sent to the supply flow rate control system 50 of the boom cylinder 4 as a target value of the boom rotation speed, and at the addition point 51, the deviation between the target value ^ref and the actual boom rotation speed is obtained. That is, in the boom cylinder control system 50, the angle detector 52 detects the boom angle α with respect to the vehicle body by a potentiometer (not shown) attached to the rotation fulcrum 0 of the boom 1, and the angular velocity calculator 53 detects this. The actual rotation speed is obtained by differentiating the angle α, and this value is fed back to the addition point 61. The deviation ( ^ref −) calculated at the addition point 51 is the compensator 6
4, the pressure oil is supplied to the boom cylinder 4 so that the deviation ( ^ref −) becomes zero through the compensator 64 and the electric oil converter 65.

The supply flow rate control systems 60 and 70 of the arm cylinder 5 and the bucket cylinder 6 are also configured in the same manner as the supply flow rate control system 50 of the boom cylinder 4, and respectively input the arm angular velocity command and the bucket angular velocity command to the respective target values. The same flow rate control as above is performed.

In the structure shown in FIG. 1, the bucket ground angle θ
When the horizontal excavation is performed with constant, the speed command unit 30 sets the lever 31 to be neutral in the rotating direction and the y direction, and tilts the lever 31 only in the x direction, so that the ground angle θ remains constant. The edge point of can be moved horizontally. If the lever 31 is tilted only in the y direction, the ground angle θ remains constant and the bucket 3
The edge point of can be moved vertically. Further, when excavating the slope, if the lever 31 is inclined in both the x direction and the y direction, the ground angle θ is kept constant at an angle determined by the speed ratio according to the inclination direction. The edge point of can be moved linearly.

By the way, in the configuration shown in FIG. 1 above, the command value that the operator directly commands is x of the bucket blade tip point.
The excavation angle ^ref and the bucket excavation speed υ ^ref may be used instead of the velocity components ▲ ^ref _d ▼ and ▲ ^ref _d ▼ in the axial and y-axis directions. In this case, these values ▲ ^ref _d ▼, ▲
^{Since ref} _d ▼, ^ref and υ ^ref have the following relation, As shown in FIG. 2, if a conversion unit 32 that performs conversion according to the above equation (11) is provided in front of the coordinate conversion unit 40, the coordinate conversion unit 40 has the same ▲ ^ref _d ▼, ▲ as described above. If y ^ref _d ▼ and −θ ^ref are input and the same arithmetic control as described above is performed thereafter, a function equivalent to that shown in FIG. 1 can be achieved.

FIG. 3 shows another embodiment of the present invention.

In the embodiment shown in FIG. 3 as well, focusing on the blade edge point D of the bucket 3 as in the previous embodiment, the velocity command section 35 indicates that the velocity components _{d 1 of} the bucket blade edge point D in the x-axis direction and the y-axis direction,
_{Although d} is output, the bucket angular velocity is set as another command element in the speed command unit 35 in this embodiment. Of these three command signals, _{d 1} ,
_d is input to the coordinate conversion unit 45.

Here, the coordinates (x _d , y _d ) of the blade point of the bucket 3 are represented by the following equations as shown in the equations (6) and (7).

x _d = L ₁ sin α + L ₂ sin (α + β) + L ₃ sin (α + β + γ)
_{...... (6) y d = L} 1 cosα + L 2 cos (α + β) + L 3 cos (α + β + γ)
... (7) These equations (6) and (7) are time-differentiated, and x at point D
When the velocity components _{d 1} and _{d 2 in} the axial and y-axis directions are obtained, the following equation is obtained.

Solving this equation (12) for, the following equation is obtained.

In the coordinate conversion section 45 of FIG. 3, based on the command signals ▲ ^ref _d ▼ and ▲ ^ref _d ▼ input from the speed command section 35 and the actual angles α, β and γ of each working machine, the above (13 ) performs a coordinate transformation in accordance with the equation, and outputs each angular velocity command ^ref and ^ref boom 1 and the arm 2. These angular velocity commands ^{ref 1} and ^{ref 2} are added points 51, 6 of each flow rate control system as described above
The deviation calculated by adding points 51 and 61 ( ^ref
Boom 1 and arm 2 are driven based on −) and ( ^ref −), respectively.

On the other hand, the bucket angular velocity ^ref set by the velocity setting unit 35
Is input to the addition point 71, and at the addition point 71, the target value
The deviation ( ^ref −) between ^ref and the actual bucket angular velocity is obtained. Then, similarly to the above, the bucket 3 is driven so that this deviation ( ^ref −) becomes zero.

That is, in this embodiment, the boom is calculated according to the following equation (14).
1, Angular velocity command for each of arm 2 and bucket 3
^Ref , ^ref and ^ref are ^calculated and these angular velocity commands
Drive the boom, arm and bucket according to ^ref , ^ref and ^ref .

According to the configuration shown in FIG. 3, for example, when performing horizontal excavation, the speed command unit 35 sets the lever 31 to be neutral in the y direction, gives a constant rotation in the rotation direction, and has a constant angle in the x direction. By inclining, the blade tip point of the bucket 3 can be moved in the horizontal direction. In this case, the ground angle θ is not constant. At this time, the bucket 3 may be fixed depending on the excavation conditions.

In such a configuration, since the movement of the blade edge point of the bucket is controlled, it is possible to obtain an accurate trajectory of the blade edge point of the bucket.

Even in this embodiment, as shown in FIG.
The bucket excavation speed υ ^ref , the excavation angle ψ ^ref, and the bucket angular velocity are used as command values, and the command value υ is calculated in the conversion unit 32.
^{The ref} and the excavation angle ψ ^ref are converted into velocity components ▲ ^ref _d ▼ and ▲ ^ref _d ▼ of the bucket blade tip in the x-axis and y-axis directions, and the converted values _d , _d and the bucket angular velocity are input to the coordinate conversion unit 45. You may do it.

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

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

〔The invention's effect〕

As described above, according to the present invention, since the trajectory of the bucket blade tip point is controlled, the operator can obtain an arbitrary trajectory of the bucket blade tip point with a simple operation, which makes the conventional difficulty. It becomes possible to easily perform the work such as the direct excavation and the slope excavation which have been performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention, FIG. 2 is a block diagram for explaining a modification of the first embodiment, and FIG. 3 is a second embodiment of the present invention. 4 is a block diagram for explaining the second embodiment, FIG. 5 is a diagram showing a configuration of a hydraulic power shovel, and FIG. 6 is a block showing a configuration example of a conventional device. FIG. 7 and FIG. 7 are explanatory views for defining the coordinate position and the like 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 unit, 30,35 ... Speed setting unit, 50, 60, 70 ... Supply flow control system, 51, 61 , 71 …… Additional points.

Claims (4)

[Claims] 1. An x-component speed setting means for setting a moving speed component of a bucket blade tip point in the x-axis direction with a plane including a boom, an arm and a bucket as a coordinate plane, and a y-axis direction of the bucket blade tip point in the coordinate plane. Y component speed setting means for setting a moving speed component, ground angular velocity setting means for setting an angular velocity of the bucket with respect to the x-axis direction, and angle detection for detecting a boom angle, an arm angle and a bucket angle. Means, the x component, the y component, the respective set values respectively set by the angular velocity setting means for ground, and the respective detected values of the angle detecting means, the boom rotating speed and the arm rotating corresponding to the set values. The coordinate conversion means for calculating and outputting the target values of the speed and the bucket rotation speed, and the boom cylinder and the arm shaft according to the respective target values derived by these coordinate conversion means. Sunda and excavators of the position control device with a flow control system for each for controlling the pressure oil supply flow rate to the bucket cylinder. 2. The x component and y component velocity setting means,
Based on the input excavation speed and excavation angle, the moving speed components of the bucket blade point in the x-axis and y-axis directions are calculated, and these calculated values are used as the set values in the x-component and y-component speed setting means to perform the coordinate conversion. The position control device for the power shovel according to claim (1), wherein the position control device outputs the position to the means. 3. An x-component speed setting means for setting a moving speed component of a bucket blade tip point in the x-axis direction with a plane including a boom, an arm and a bucket as a coordinate plane, and a bucket blade tip point in the y-axis direction on the coordinate plane. Y-component speed setting means for setting a moving speed component, bucket angular speed setting means for setting a rotation speed of a bucket, respective angle detecting means for detecting a boom angle, an arm angle and a bucket angle, the x-component and y-component Based on each set value set by the component speed setting means and each detected value of the angle detecting means, respective coordinates for calculating and outputting the target values of the boom rotating speed and the arm rotating speed corresponding to the set value. The converting means, and the boom cylinder and the arm according to the respective target values derived by these coordinate converting means and the bucket rotation speed set by the bucket angular speed setting means. A position control device for a power shovel, comprising a flow rate control system for controlling the flow rate of hydraulic pressure supplied to a cylinder and a bucket cylinder. 4. The x component and y component velocity setting means,
Based on the input excavation speed and excavation angle, the moving speed components of the bucket blade point in the x-axis and y-axis directions are calculated, and these calculated values are used as the set values in the x-component and y-component speed setting means to perform the coordinate conversion. The position control device for the power shovel according to claim (3), wherein the position control device outputs the power to the means.