JPS59195938A - Linear excavation controller for oil-pressure shovel - Google Patents

Abstract

PURPOSE:To optionally alter the position of the cutting edge of a bucket even during the automatic operation period by a method in which detected values on the operation amount of a manual operating lever are put in the arithmetic unit of a linear excavation controller and added to speed command value during the automatic operation period. CONSTITUTION:On the basis of tangent speed signal Vt from the speed input pedal 19 of an input unit 9 and excavation angle signal phi from an angle setter 20, the speed components vx and vy at the tip of a bucket 4 are calculated in a bucket tip speed arithmetic block 15. Also, in an angle and angular velocity arithmetic block 16, on the basis of relative angle signals beta, alpha, and gamma of boom 2 and vx and vy, relative angular velocity signals betar, alphar, and gammar are calculated, and on the basis of these, the flow rate of pressure oil to cylinders C1-C3 is regulated by flow rate controllers 17 and 18, and the cutting edge of the bucket 4 is moved on the straight line W. When operating levers 21-23 are operated then, the manual command values alpha'M, beta'M, and gamma'M are put in the block 16, relative angular velocity signals betar, alphar, and gammar are corrected, and the bucket 4 can thus be moved to a desired direction.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an excavation locus control device for a hydraulic excavator, and more particularly to an excavation locus control device for a hydraulic excavator, and more specifically, an I/O device for controlling the motion locus of a packet cutting edge of a hydraulic excavator.
41.

[Background of the invention]

A hydraulic excavator generally consists of a boom installed on a revolving body, a boom cylinder that raises and raises the boom, an arm attached to the tip of the boom, an arm cylinder that swings the arm, a packet attached to the tip of the arm, and a boom cylinder that raises and raises the boom. It is equipped with a packet cylinder that can be oscillated. usually,
Each cylinder is operated by an operating lever placed in the driver's seat.

When performing simple excavation work using this hydraulic excavator packet, it is sufficient to operate each lever and each hydraulic cylinder in sequence, but when performing work such as finishing work on a slope or horizontally excavating the bottom of a trench, In order to move the packet cutting edge along a fixed straight line, levers corresponding to a plurality of cylinders must be operated simultaneously, which not only requires considerable skill but also reduces work efficiency.

In order to solve this problem, various measures have been proposed to automate the straight-line movement of the packet cutting edge in a hydraulic excavator, so-called straight-line excavation. One such solution is described in Japanese Patent Publication No. 54-37406. This linear excavation control device performs calculations based on commands from an operation panel consisting of an operation lever that determines the movement speed of the arm tip, dials that set the angle of the excavation surface and packet attitude angle, and an automatic/manual changeover switch. The control device calculates the operating angles of the boom, arm, and packet to achieve the desired excavation trajectory, and based on the calculation results, the hydraulic servo mechanism operates the boom.

This is to follow the operating angle of the arm and packet.

With this automatic excavation control device, the packet cutting edge can be moved along a straight line trajectory given by the operation panel, but during automatic excavation, a situation arises in which the driver wants to change the moving trajectory of the packet cutting edge according to his will. If
Temporarily stop automatic operation and switch to manual operation mode, move the packet cutting edge to the desired position using the manual operation lever,
After that, you have to go through the steps of switching to automatic mode and digging automatically. This operation is complicated and, in practice, it is impossible to interrupt manual operation during automatic operation.

[Purpose of the invention]

The present invention allows the vertical position of the packet cutting edge to be freely adjusted according to the driver's will, even during automatic excavation operation in which the packet tip is moved multiple times along a desired straight cutting path. The purpose of the present invention is to provide a linear excavation control device for a hydraulic excavator with functions that can be changed to

[1 Summary of the Invention] The linear excavation control device of the present invention detects the amount of operation of the manual operation lever of the hydraulic excavator, and directly inputs the detected value as a manual speed command value to the arithmetic and control device of the excavation control device. Hydraulic Noyobel's linear excavation city 1 has a function that allows the position of the packet cutting edge to be arbitrarily changed according to the driver's will even during automatic operation by adding it to the speed command value during automatic operation.
j# Realize the device.

Embodiment Fig. 1 shows the front mechanism of a hydraulic excavator equipped with a control device according to the invention. 3 is an arm attached to the tip of boom 2, 4 is an arm attached to the tip of boom 2,
is a packet attached to the tip of arm 3. These boom 2, arm 3, and packet 4 are operated by a boom cylinder c11, an arm cylinder C2, and a packet cylinder c3, respectively. These boom 2, arm 3
1 and the packet 4 are detected by detectors 5 to 7 provided at or near each pivot point.

The detected values of the detectors 5 to 7 are transmitted to the input side by a detection circuit 8. An input device 9 is installed in the driver's seat (not shown) of the hydraulic excavator.・This human-powered device 9 is an excavation surface lol
It is equipped with dials for setting the slope of the excavation, a foot pedal for setting the excavation speed, and operation levers for operating the hydraulic excavator in a conventional manner. is the linear excavation speed vt1
Inclination of excavation surface φ, operation amount of manual lever” M + I
M l r M is input.

The arithmetic and control unit 1o calculates the velocity component of the packet tip based on the linear excavation speed V and the slope φ of the excavation surface W, and determines whether the packet tip P (X, y) is on the desired excavation trajectory, that is, the start of excavation. Point Po(Xo.

yo), and calculates the operating speed of the boom cylinder C□ and arm cylinder c2 required to move along the straight line expressed by the excavation angle φ (and calculates the operating speed of the boom cylinder C□ and the arm cylinder c2 required to move along the straight line expressed by the excavation angle The operating speeds of the hydraulic oil pumps connected to the hydraulic cylinders are added together, and the flow rate of the pressure oil to be supplied to each cylinder is calculated based on the effective pressure receiving area of each cylinder. Control the speed of the hydraulic cylinder by changing the flow rate,
The present invention will be described in detail by taking a so-called pump control system as an example.

In the case of a pump control system, the output of the computer controller 10 is sent to the pump controller 11.

Pump Will 641 device 11 rotates around the swash plate 1 of each hydraulic pump 12, 13, 14 and pump swash plate with swash plate tilting position 16 obtained from detectors 12a, 13a, 14a which leak It. It is compared with the tilting vertical position manual signal (pump discharge flow rate signal), and if there is an error between the two, the swash plate tilting position of each pump 12 to 14 is controlled Iti in a direction that reduces the error.

The pressure oil discharged by the hydraulic pumps 12 to 14 is directly
It is guided to each cylinder 01 to C3. As a result, the tip of the packet 4 of the hydraulic excavator moves along a desired linear trajectory. If the manual operation lever is operated midway, the tip of the packet 4 is controlled to deviate from the original straight line according to the driver's will. Note that in the hydraulic circuit shown in Figure 1, the hydraulic pump and single rond cylinder are shown as being directly connected for simplicity, but in an actual hydraulic circuit, the pump discharge flow rate and suction flow rate exceed the amount that occurs as the hydraulic cylinder expands and contracts. It is equipped with hydraulic equipment such as charge pumps and flushing valves to compensate for deficiencies.

The arithmetic and control unit 10 shown in FIG. 1 will be explained in more detail.

FIG. 2 is a functional block diagram of the arithmetic and control device 100. Arithmetic control unit 10 - Kukerato tip speed calculation block 15
, angular velocity calculation block 16, servo control block 1
7. IA is constructed from the pump flow rate conversion block 18.

In the packet tip speed calculation block 15, the speed components v1 and v of the packet tip are calculated from the tangential speed signal vt from the speed large dial 19 of the input device 9 and the excavation angle signal φ from the angle setting dial 20. One relationship between input and output in this calculation block can be expressed as follows.

V knee tcO8φ ・・・・・・・・・
(1) V t sinφ...
(2) The angular velocity calculation block 16 calculates the packet tip velocity components v, , vy, which are the outputs of the packet tip velocity calculation block 15, and the manual operation levers 21, 22° 23
Based on the arm angular velocity manual command value αM1 from the poom angular velocity manual command value IM and the packet angular velocity manual command value 7M and the relative angles 1g of the poom 2, arm 3, and packet 4 from the detection circuit 8, 2. Arm 3
, relative angular velocity command signal of packet 4 Table 2. (1,, r
r and relative angle command signal β1. α2. γ, is calculated and output.

In order to perform this calculation, the angles and lengths of each part of the hydraulic excavator are determined as follows based on FIG. Horizontal, with position 0 of the poom foot pin as the origin of coordinates.
A four-axis X and Y coordinate system is created in the vertical direction. Rotation fulcrum of arm 3 with respect to poom 2 &A, rotation fulcrum of packet 4 with respect to arm 3 as B1 packet tip as P /AOX=β /BAO-90°-α /PBA-90°-γ OA=L b AB =L.

B P = L a When the angle and length are determined in this way, the relationship between the velocity components V z , V y at the packet tip P, the packet rotation angular velocity i, and the angular velocity β of the poom 2 and the angular velocity α of the arm 3 is expressed by the following equation: It can be written as:

1-[-v, (L, 5in(β+α)-Ldcos
(β+α+γ))+v,+L,CO3(β+α)
+Ldsin (β+α+γ))L−La cosγ
+ 7'] / [Lb (La cosα+Ldsi
n Ca+r) l)・・・・・・・・・(3) ;””CVx (LbCOSβ+L, 5in(β+α
)-LdCO8(β+α+γ) l %+, (-L
bsinβ+L acos (β+α)+Ldsin(
β+α+γ)) (Lb La5in(α+γ)+L
, LdCO3γ) )/(Lb (CO3α+Ld
sin(CI+4) l)・・・・・・・・・(4) −t, that is, if the angular velocities of boom 2 and arm 3 and β are controlled as in equations (3) and (4), respectively, The packet tip P moves on a straight line. Furthermore, when the angular velocity manual command values βM, C'M, and γM of each member are input, (3
) and (4) are calculated by adding βM and αM to obtain the corrected angle command values β1 and C1. Further, since the packet angle γ can only be moved manually, the packet angular velocity command value 7:r is equal to the manual command value γM.

As described above, if the angular velocities of boom 2, arm 3, and packet 4 are controlled, the packet tip P moves on a straight line trajectory when no manual operation command value is input, and when a manual operation command value is input, the packet tip P moves accordingly. Although linear excavation trajectory control in which P deviates from the initial linear trajectory can be realized, in reality, the desired movement cannot always be obtained due to various control errors. ．． β1. It is also necessary to calculate γ, compare it with the actual angles α, β, and γ, and correct it.

Momentary target angle α1. β2. γ1 is C1°7r17
'r and initial value α. , β0. αr(t) using γ0
= f α, dτ+α0 ・・・・・・・・・(
5) β, (t) −f βrdτ+β0 ・・
・・・・・・・・・(6) γ, (t)−f γ, dτ+
γ0 It can be calculated as (7).

FIG. 4 represents the above operations in the form of a block diagram. That is, the outputs "M, /'M of the input device 9 and the packet tip speed calculation block 15.

γM+vx+Vy and the initial values β0 of the boom, arm, and packet angles at the start of excavation obtained from the detection device 8;
As the C0, γat input, the target angular velocity β of the boom 2, arm 3, and packet 4 of the hydraulic excavator, , (1,, 7,
It also calculates and outputs target angles β...α...γr. In FIG. 4, AD is the addition block,
MU represents a multiplication block, DI represents a division block, IN represents an integral block, S represents a sine function block, CO represents a cosine function block, and K represents a coefficient block.

Next, the servo control block 17 will be explained in detail.

FIG. 5 is a block diagram showing processing in the servo control block 17. The symbol in the figure is A as in Figure 4.
D represents an adder, and K represents a coefficient unit. That is, to explain the arm system, the arm angle command value α, which is the output of the angular angular velocity calculation block 16, and the actual arm angle α
and take the difference, and add coefficients K and x to the value εσ.
The result of the multiplication is added to the arm angular velocity command value obtained from the angular velocity calculation block 16, and a new arm angular velocity command value α is output. Boom type.

Similar processing is performed for the packet system to output the boom angular velocity command value β and the packet angular velocity command value i.

Next, the pump flow rate conversion block 18 will be explained using FIG. 6. In FIG. 6, reference numerals 24 to 26 are function generators which input angle signals α, β, and γ of each member of the excavator and output the ratio between the cylinder velocity and angular velocity of each member.

That is, when arm angle α is input to the function generator 24, the ratio of cylinder speed Z2 and arm angular velocity α to that α is output. Multiplying this z 2/a K i,
The arm cylinder speed Z2 at that time is obtained. The boom cylinder speed Z1 and bagut cylinder speed Z3 are obtained in the same manner. Hydraulic cylinder C at these cylinder speeds
1, C2, and the pressure receiving part 4* of Ca, the hydraulic pump 12
, 13.14 are obtained, but since the hydraulic cylinder used in a hydraulic excavator is a single-rond cylinder, it is difficult to choose whether to select the area on the head side or the area on the rond side as the pressure receiving area of the hydraulic cylinder. It becomes a problem. Since the pump 1σ1] dual method has been described as an example of a hydraulic excavator, a method for determining the effective pressure receiving area of a hydraulic cylinder based on the position of the seven lasing valves provided in the hydraulic closed circuit will be described.

FIG. 7 is a circuit diagram of a hydraulic circuit including the cylinder C2 and the hydraulic pump 13. This circuit has a group L that compensates for the shortage of pressure oil in the circuit that occurs when the single rod/cylinder C2 is pushed out, and the leakage that flows out from the hydraulic closed circuit to the outside.
A charge pump 27 for returning the excess pressure oil generated when the hydraulic cylinder is retracted 1 to the tank 5, a flushing valve 28, a low pressure relief valve 29, and a check valve 3
0.31 etc. are provided.

The flushing valve 28 connects the lower circuit of either the rod side or the head side of the hydraulic cylinder C2 to the low pressure relief valve. Hence the hydraulic/linda.

The moving speed of C2 is calculated by dividing the discharge flow rate of the hydraulic pump 13 by the pressure receiving area of either the head side or the rod side, whichever is the high pressure side.
Become direct.

A limit switch 32 is provided on the flushing valve 28 so that when the pressure on the head side is high, a signal S= is output σ when the flushing valve is in the state (2). In this state, the effective pressure receiving area of the hydraulic cylinder C2 is the area A1a on the head side, and when this is not the case, that is, when the signal Sa is not output, the effective pressure receiving area of the hydraulic cylinder C2 is the pressure receiving area A2.1 on the rod side.

The right side of FIG. 6 is a block for calculating the flow rate qα to be discharged by the hydraulic pump using this principle. That is, the hydraulic cylinder speed Z2. The configuration is such that a correct discharge flow rate can be obtained by switching the coefficient unit corresponding to the area to which Zt and Za should be multiplied.

In this way, the flow rate command signals qa, qβ+qr obtained by the arithmetic and control device 10 are sent to the pump control device 11, respectively.

The pump control device 11 controls the tilting position of the swash plate of each pump so that each pump 12, 13, and 14 discharges a flow rate according to this flow rate command signal.In this way, the hydraulic/yovel linear excavation control is performed. When the device is configured, the tip of the hydraulic excavator moves on a straight line trajectory of φ at the speed given by the foot pedal 19 of the input device 9, and moreover, during automatic direct excavation operation,
If, for some reason, the driver decides that he wants to change the packet tip trajectory from the original straight line trajectory,
All of this can be achieved by creating 23 corresponding manual actuation levers. Therefore, since the driver's will is reflected at any time while the automatic direct excavation control device is used, continuous rotation can be performed without any discomfort.

In the above description, the content of the arithmetic control device 10 has been explained in analog form to make it easier to understand. This does not deviate from the main idea.

In addition, in the explanation of the four friends, A of the pressure oil co-supplied to the hydraulic nolinda.
Although a variable discharge amount pump was used as the four-way control means, it goes without saying that the control device of the present invention can be constructed using hydraulic pressure and a control valve (servo valve).

〔Effect of the invention〕

As mentioned above, when the linear excavation control device for a hydraulic excavator according to the present invention is used, the position of the packet cutting edge can be arbitrarily changed by manual operation according to the will of the driver during the process of automatic linear excavation. The operability is significantly improved compared to the conventional manual/automatic switching system.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a hydraulic excavator equipped with an example of the control device of the present invention and one sub-example of the configuration of its hydraulic circuit, FIG. 2 is a functional block diagram of the arithmetic and control device constituting the present invention, and FIG. What's the diagram? FIG. 4 is a block diagram showing the execution processing contents of the angular velocity calculation block constituting the present invention, and FIG. 5 is a diagram showing the execution processing of the servo control block constituting the present invention. A block diagram showing the contents,
FIG. 6 is a block diagram showing the operational details of a flow rate variable block that embodies the present invention, and FIG. 7 is a circuit configuration diagram of a hydraulic closed circuit including a single rod cylinder. 1... Swivel body, 2... Boom, 3... Arm, 4...
...Packet, 5-7... Production device, 8... Production circuit, 9... Input device, 10... Arithmetic control device, 11.
...Pump control device, 12-14...Hydraulic pump, C
1...Boom cylinder, C2...Arm cylinder,
C3...Bucket l/Linda.

Claims (1)

[Claims] l. The boom is the front mechanism of a hydraulic excavator. Manipulate each packet and packet with a cylinder,
In the apparatus for moving the cutting edge of the packet on a desired linear trajectory, there is provided a pressure oil flow rate control means for controlling the flow t of pressure oil to be supplied to each cylinder, and an arbitrarily settable slope of the excavation surface, excavation speed, and front. In order for the packet cutting edge to move along a desired straight line trajectory based on input means for providing conditions for the relative angles of each part of the mechanism, conditions for the slope of the excavation surface, excavation speed, and relative angles of each part of the front mechanism from this input means. Pressure oil flow to each cylinder: ijtk is calculated, and the flow rate of pressure oil to each cylinder is calculated to cause the packet cutting edge to deviate from the desired linear trajectory based on the relative angle command of each part of the front mechanism from the input means. A linear excavation control device for a hydraulic excavator, characterized in that it is equipped with a control means. 2. The arithmetic control means adds the relative angle commands of each part of the front mechanism from the input means to the target value of the pressure oil flow rate for straight @ excavation, and controls the packet cutting edge in its position even during automatic straight excavation operation Tfm. Claim 1, characterized in that the flow rate of pressure oil to each cylinder is calculated to deviate from the trajectory.
Direct excavation control device for a hydraulic excavator as described in Section 1.