JPS59195939A - Linear excavation controller for oil-pressure shovel - Google Patents

Abstract

PURPOSE:To make a linear excavation control for an oil-pressure shovel by a method in which any change of the attitude of a bucket by an operator is allowed and also detected or estimated, and flow rate is obtained according to the effective pressure-receiving area of the cylinder of boom and arm. CONSTITUTION:The flow rate of pressure oil to be supplied to a boom cylinder C1, an arm cylinder C2, and a bucket cylinder C3 are obtained from freely settable excavating face slope angle phi, excavation speed Vt, bucket angle r', and relative angles alpha, beta, gamma of boom, arm, and bucket by an arithmetic unit 10. By output of limit switches Salpha, Sbeta, and Sgamma provided to the cylinders C1, C2, and C3, the effective pressure-receiving area A of the oil-pressure cylinder is selected, and flow rates to the boom cylinder C1 and the arm cylinder C2 are controlled according to the change input of the bucket angle while keeping the cutting edge of the bucket on desired straight line locus.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an excavation trajectory control device for a pump-controlled hydraulic novel, and more particularly to a device for controlling the motion trajectory of a packet cutting edge.

[Background of the invention]

A hydraulic excavator generally consists of a boom mounted on a revolving body, a boom/linda that raises and raises the boom, an arm attached to the tip of the boom, an arm/linda that swings this arm, and an arm/linda attached to the tip of the arm. It includes a packet and a packet cylinder that swings the packet.

Usually, each cylinder is operated by an operating lever located at the driver's seat.

When performing simple 7z excavation work using this hydraulic noyobell packet, it is sufficient to operate each hydraulic cylinder in sequence by operating each lever, but when performing simple 7z excavation work using the packet When moving the cutting edge along a fixed straight line, levers corresponding to a plurality of cylinders must be operated at the same time, which not only requires a considerable amount of heat, but also impairs work efficiency.

In order to solve this problem, various measures have been proposed to completely automate the straight-line movement operation of the packet cutting edge in a hydraulic excavator, so-called straight-line excavation. One such solution is the one described in Japanese Patent Publication No. 54-37406. This linear excavation control device controls the movement locus of the tip of the arm to follow a desired straight line, and also controls the attitude of the packet to maintain a constant value with respect to fixed coordinates (surface to be excavated).

This control method can improve excavation efficiency because it can always maintain the packet attitude at a cutting edge angle that provides good excavation efficiency with respect to the excavated surface, but conversely, the relative angle of the packet to the arm changes as excavation progresses. Therefore, when the packet approaches the vehicle body, the packet cylinder reaches the end of its stroke, which has the disadvantage that the range that can be excavated in a straight line becomes narrower. Furthermore, if the packet angle is changed by manual priority control during straight-line excavation, the excavation trajectory will deviate significantly from the desired straight line.

[Object of the Invention] An object of the present invention is to propose an excavation trajectory control device for a hydraulic excavator that can control the trajectory of the tip of the packet of a hydraulic excavator to follow a desired straight line in any packet posture.

[Summary of the invention]

The excavation trajectory control device of the present invention allows the packet attitude of the hydraulic excavator to be changed according to the driver's will even during straight excavation operation ((and also detects or predicts changes in the packet attitude to adjust the position of the boom and arm). The operation is controlled so that the movement trajectory of the packet tip follows the desired 11 lines, regardless of the packet orientation.

[Embodiments of the invention]

Fig. 1 shows a front machine mt of a hydraulic excavator equipped with an example of the control device of the present invention. The arm 4 is attached to the tip of the boom 2 and is attached to the packet attached to the tip of the arm 3. The boom 2, arm 3, and packet 4 of Kohachi are respectively a boom cylinder C1, an arm/cylinder C2, and a packet cylinder C.
Operated by 3. The relative angles of these boom 2, arm 3, and packet 4 are detected by detectors 5 to 7 provided at or near each cardinal point.

The detection signals of the detectors 5 to 7 are transmitted to the input side by the detection circuit 8. A human power device 9 is installed in the driver's seat (not shown) of the hydraulic excavator. This input device 9 is the excavation surface W
The excavator is equipped with dials for setting the slope, control levers for setting the excavation speed, and control levers for operating the hydraulic excavator in a conventional manner. The excavation speed is determined by the input device 9 as a secular component V! according to the slope of the excavation surface. and a vertical component v, and the signal is sent to the arithmetic unit 10.

The arithmetic unit 10 calculates the velocity component vx at the tip of the packet.

From v, packet destination 4 (x, y) is the desired excavation trajectory,
In other words, passing through the excavation start point (Xo + Yo), lf is expressed as the angle φ set with the excavation angle setting dial.
Boom cylinder C1 required to move along the i-line
and the operating speed of the arm cylinder C2, and further calculate the flow rate of the pressure oil to be supplied to each cylinder, that is, the pump swash plate tilting position input, from the effective pressure receiving area of each cylinder. These input signals are sent to the pump controller 11.

Furthermore, in the present invention, the packet 4 is characterized in that it can be operated in a normal manner, so the flow rate to be supplied to the nokkerato cylinder C3 is determined independently of the excavation trajectory, and the pump required to realize it is determined independently of the excavation trajectory. A swashplate tilt device input signal is sent to pump controller 11 .

The pump control device 11 is a hydraulic pump 12, 13, respectively.
．． Detectors 15, 16.1 for detecting the tilted position of the swash plate 14
The swash plate tilt position signal obtained from 7 and the pump swash plate tilt position input signal are compared, and if there is an error between the two, the swash plate tilt of each pump 12 to 14 is adjusted in the direction that reduces the error. Control position. The pressure oil discharged from the hydraulic pumps 12 to 14 is directly led to the respective nolinders 01 to C3. In addition, the tip of the packet 4 of the hydraulic excavator moves along a desired linear trajectory. In the hydraulic circuit shown in Figure 1, the hydraulic pump and single-rod hydraulic cylinder are directly connected and shown as 7 for simplicity, but in an actual hydraulic circuit, the pump discharge flow rate and suction flow that occur as the hydraulic cylinder expands and contracts. It is equipped with a charge pump and flushing hydraulic equipment to compensate for excess or deficiency in flow rate.

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. The arithmetic and control unit 10 includes a packet tip speed calculation block 15,
Angular angular velocity calculation block 116, servo control block 1
7. It is composed of a pump flow rate conversion block 18.

The packet tip speed calculation block 15 is a part that calculates the velocity components vx and vy of the packet tip from the connection speed signal Vt from the speed input lever 19 of the input device 9 and the excavation angle signal φ from the angle setting dial 20, The input/output relationship in this calculation block 15 can be expressed as follows. That is, vx −V (CO3−(1
) V, ”=V t 5illφ (2) The angular velocity calculation block 16 calculates the packet tip velocity components vx, va, which are the outputs of the packet tip velocity calculation block 15, and the packet angular velocity command value from the packet operation lever 21 of the input device 9. ?, and relative angle signals β, α, and γ of the boom 2, arm 3, and nokkerato 4 from the detection circuit 8, the relative angular velocity command signals β1, , and n of the boom 2, arm 3, and packet 4 are , and the relative angle β1.α
,.

γ, is calculated and output.

In order to execute this calculation, the angles and lengths of each part of the hydraulic excavator are determined as follows based on FIG. The boom foot pin position O constitutes an X, Y coordinate system in the horizontal and vertical directions as the origin of all coordinates. Rotation fulcrum of arm 3 with respect to boom 2 is A1 Rotation fulcrum of packet 40 with respect to arm 3 'CB z The tip of the bucket is P /AOX-β /BAO-90°-α /PBA-90°-γ Shin-Lb AB= L.

B P = L a By determining the angle and length in this way, the velocity component at the tip of the kerato P, V, V, the angular velocity of the kerato rotation, the angular velocity β of the boom 2, the angular velocity of the arm 3, and The relationship can be expressed as the following equation.

β-[-v! (L-sin(β-toα) LdCO5
(β 10 α + γ month 10 vy (L, CO3 (β 10 α) + Lds
in(β+α+r))L-LaCO3r・Chest/CL
b(LmcoS(10L dsin (α+γ month)...
...(3)" -Cv x (L bcO3β+L
a5in(βtenα)-ri, C03(βtenα+γmonth-Vy
(Lbsinβ+L & CO3(β+α)+Ldsi
n(β+a-+-r))(Lb L asin'((1
+r)+L , :[,dcosγ)]/[Lb(coS
a+L dsin (α10γ month) ------
-(4) Also, the relationship between the angular velocity "+ 7+ r and the angles α, β, and γ is as follows: If time is t and the initial value of angles α, β, and γ (1st shift at the start of automatic operation) rα0.A0.γ0 It is obvious that α(t)−f,” ;x dτ×α0 ・
...(5) β (t) - fJ) dτ + β0
......(6) γ(t)=f, "'r
d r+ro −・−・・(7).

FIG. 4 is a block diagram representing the calculations of the relationships in equations (3) to (7).

As the input device 9 and the output cuff 'r, Vx, yk input of the packet tip speed calculation block 15, the target angular velocities β1.R2.9 of the poom 2, arm 3, and hippacket 4 of the hydraulic noyobel and the target square box β1.9 are input. It calculates and outputs α and r.

In FIG. 4, AD represents an addition block, IVU a multiplication block, DI a division block, IN an integral block, SI a sine function block, CO a cosine function block, and K 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 symbols in the figure are the same as in FIG. 4, where AD represents a Gallo calculator and K represents a coefficient multiplier. That is, to explain the arm system, the angular angular velocity calculation block 16
The arm angle if command value α, which is the output of
The light result obtained by multiplying by a is added to the arm angular velocity command value which is the output of the angular angular velocity calculation block 16, and a new arm angular velocity command 1-direction α is output. The same process is applied to the boom system and packet system to obtain the boom angular velocity command value β.
and outputs the packet angular velocity command value γ.

Next, the pump flow rate conversion block 18 will be explained using FIG. 6. In FIG. 6, reference numerals 21 to 23 designate function generators that 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.

When the arm angle α is input to the t-line b1 function generator 21, the arm/linda speed Z2 relative to that α is obtained.

The arm/linda speed Z1 and the packet 7 cylinder speed Z3 are obtained in the same manner. Multiplying these cylinder speeds by the pressure receiving area of the hydraulic cylinders C1, C2, and Cs gives the flow rate to be discharged by the hydraulic pumps 12, 13, and 14, but since the hydraulic cylinder used in the hydraulic noyobell is a single rod cylinder, , the area on the head side is selected as the pressure receiving area of the hydraulic cylinder, but the question is whether to select the area on the rod side.

Since the pump control system for a hydraulic excavator has been explained as a typical example, a method for determining the total effective pressure receiving area of the hydraulic pressure/cylinder based on the position of the flushing valve provided in the hydraulic closed circuit will be explained.

FIG. 7 is a circuit diagram of a hydraulic circuit including the arm cylinder C2 and the hydraulic pump 13. This circuit includes a charge pump 24 for compensating for the shortage of pressure oil in the circuit that occurs when the one-rod cylinder cylinder C2 is pushed out and for the leakage that flows out from the hydraulic closed circuit to the outside, and a charge pump 24 that occurs when the hydraulic cylinder is retracted. Flushing valve 25, low pressure relief valve 26, check valve 27.287 for returning excess pressure oil to the tank
z is provided.

The brushing valve 25 is connected to the rod π(υ
Connect either the lower circuit on the head side to the low pressure relief valve. Therefore, the moving speed of the hydraulic cylinder C2 depends on the discharge flow rate of the hydraulic pop 13, whether it is on the head side or the rod side.
It is 1 shift divided by the pressure receiving surface fault on either 4% pressure side.

Now install the limit switch 29 on the flushing valve 25Q
A. When the pressure on the head side is good, that is, when the 7 latching valve is in a working condition, the signals S and X should be output. In this state, the effective pressure receiving area of the hydraulic cylinder C2 is the area kla on the head side; otherwise, the signal S. When there is no output, the effective pressure receiving area of the hydraulic cylinder C2 is the pressure receiving area on the rod side. becomes.

The right side of FIG. 6 is a block for determining the flow rate q to be discharged by the hydraulic pump using this principle. That is, the signals from the limit switches, S, , Sβ, S, &
Therefore, the coefficient machine corresponding to the area to be multiplied by the hydraulic cylinder speeds Z2, Z+, and Za is switched to obtain a correct discharge miscarriage.

In this way, the flow rate command signals qα, 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, 14 discharges a flow rate according to the flow rate command signal.

When the hydraulic excavator's linear excavation node is configured in this way, the packet tip of the hydraulic excavator moves on a straight line trajectory with an inclination φ at a speed given by the operating lever 19 of the input device 9, and furthermore, The attitude angle γ of the packet 4 can be controlled at any time using the packet operating lever 21 of the human-powered device 9. Even if the attitude angle γ of the packet 4 is arbitrarily changed, the tip of the packet 4 will not deviate from the desired linear trajectory.

In addition, in the above explanation, the contents of the arithmetic and control device 10 are as follows.
For the sake of clarity, the explanation has been given in analog terms; however, it does not depart from the spirit of the present invention even if the arithmetic and control unit 10 is configured by digital means such as a microcomputer.

In addition, in the explanation of the actual flow example, a variable discharge amount pump was used as a means for controlling the flow rate supplied to the hydraulic cylinder, but it should be noted that the control device of the present invention can also be configured using a hydraulic control valve (subo valve). not.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to change the attitude of the packet at any time during the process of automatic linear excavation, and even if the attitude of the packet is changed, the trajectory of the packet tip will not deviate from the desired linear trajectory. do not have. Hence the straight-line drilling strike.

In addition to being able to take a longer load, the operability of the hydraulic excavator is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of a hydraulic circuit of a hydraulic excavator that is fully equipped with an example of the control device 4 of the present invention, FIG. 2 is a functional block diagram of the arithmetic and control device used in the present invention, and FIG. FIG. 4 is a block diagram showing the execution processing contents of the angular velocity calculation block constituting the present invention, and FIG. 5 shows the execution processing contents of the servo control block constituting the present invention. FIG. 6 is a block diagram showing the content of execution processing of the flow rate conversion block constituting the present invention, and FIG. 7 is a circuit configuration diagram of a hydraulic closed circuit including a single-rod norinda. 1... Swivel body, 2... Boom, 3... Arm, 4
... Packet, 5-7... Detector, 8... Detection circuit, 9... Input device, 10... Arithmetic control device, 11
...Pump control device, 12-14...Hydraulic pump,
cl...poom cylinder, C2...arm/'linter\C3...packet cylinder.

Claims (1)

[Claims] 1. A boom which is a structure of a hydraulic excavator. The arm and packet are each operated by a cylinder,
In the device for moving the cutting edge of the packet on a desired linear trajectory, there is provided a pressure oil flow rate 11 control means for controlling the flow rate of pressure oil to be supplied to each cylinder, and an optionally settable slope of the excavation surface, excavation speed, and packet. an input means for giving an angle condition, and pressure oil to each cylinder in which the packet cutting edge moves in a desired linear trajectory based on the conditions from this input means and the relative angle layers of the boom, arm, and packet of the front structure. In addition to calculating the flow rate, the present invention also includes calculation control means for calculating the flow rate of pressure oil to the boom cylinder and the arm cylinder until the packet cutting edge moves from a desired linear trajectory in accordance with input changes in the packet angle. Features a linear excavation control device for hydraulic excavators. 2. The calculation control means includes a calculation unit that calculates the packet tip speed based on the slope of the excavation surface and excavation speed conditions from the input unit, the packet tip speed from this calculation unit, the packet angle command from the input unit, and each part of the front mechanism. A calculation unit that calculates target speeds and target angular velocities of the boom, arm, and packet based on the actual splice angle of The first claim characterized in that
A linear excavation control device for a hydraulic excavator as described in Section 1.