JPS5968437A - Automatic operator for straight-line excavation by hydraulic shovel - Google Patents

Abstract

PURPOSE:To automatically excavate the ground straightly by a bucket by a method in which the slope of a face of excavation is set up in advance, calculation is made on the basis of the detected values and set values for the operational positions of each movable part, and the movement of an hydraulic cylinder is controlled. CONSTITUTION:A bucket 4 is set at an optional position as an automatic operation start-up position. In this case, alpha value (relative angle between an arm 3 and a boom 2) and beta value (relative angle between the boom and the vehicular body), obtained from detectors 9 and 10, are set up as initial conditions for integrators I3 and I4. Subsequently, the slope phi of plane to be excavated is set and an operation lever is operated, whereupon horizontal and vertical components of excavation speed are sent out to an arithmetical circuit. In the arithmetical circuit, alpha and beta values necessary for excavation along the area from the automatic operation start-up point to the slope phi are calculated and sent out as input signal IP to a servo amplifier 8. In the servo amplifier 8, a deviation between the input signal IP and present values of alpha and beta is obtained, and according to the deviation, hydraulic control valves 13 and 14 are operated for automatic excavation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic linear excavation device for a hydraulic excavator.

As shown in Fig. 1, a hydraulic excavator generally includes a hydraulic boom cylinder c1 that raises and raises a boom 2 supported by the swinging weight, and a hydraulic boom cylinder c1 that swings an arm 3 attached to the tip of the boom 2. It is equipped with an arm cylinder C2 and a hydraulic bucket cylinder C3 for tilting a bucket l-4 attached to the tip of the arm 3, and each cylinder is operated by a lever placed on the driver's seat 5. Simple excavation work can be performed by sequentially operating these hydraulic cylinders, but when moving the bucket 4 along a fixed straight line, such as when finishing a slope or horizontally excavating the bottom of a trench, Each hydraulic cylinder must be operated simultaneously. Conventionally, such work has only been performed by highly skilled drivers, and in most cases the work has been done by hand, resulting in poor efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide an operating device that can automatically perform the above-mentioned linear excavation work that is performed on a hydraulic excavator.

An embodiment of the present invention will be described below with reference to the drawings.

In the hydraulic excavator shown in FIG. 1, in order to excavate along a straight line such as PQ (hereinafter referred to as bucket position F), the tip of arm 3, which is a representative point indicating the position of bucket 4, must be (hereinafter referred to as bucket position F) may be controlled along a moving trajectory along a straight line. The movement trajectory of the arm tip is controlled by boom 5 ring C
1. By simultaneously operating the arm cylinder C2, the attitude of the bucket 4 is controlled by operating the bucket I and the cylinder C3. However, in normal straight line excavation, bucket operations are often not performed in order to widen the excavation area as much as possible.

Now, if we choose the rotation center O of boom 2 as the origin and set the horizontal direction as the X axis and the vertical direction as the Y axis, the values of the coordinates (x, y) representing the bucket position F will be the same for arm 3 and boom 2. Relative angular displacement of /DCB-α (angular displacement corresponding to the displacement of arm cylinder C2) Angular displacement between the boom and the vehicle body, <AOB
= β (angular displacement corresponding to the displacement of boom cylinder C1) is expressed as a function as a variable, and conversely, if the values of (x, y,) are given, the corresponding values of α and β can be found. . That is, the bucket position F is set to an arbitrary position (x,
It is possible to obtain the values of α and β (therefore, the displacements of the boom cylinder C1 and the arm cylinder C2) necessary for positioning at the position (y). Therefore, the coordinates (x, ”
y), the momentary values of α and β required when the bucket position F moves along p/Q/ can be obtained. Taking these values as input signals, α.

If the displacement of boom cylinder C1 and arm cylinder C2 is controlled so that the value of β exactly matches the human power signal,
The movement trajectory that the bucket position F actually passes is P/Q/
matches.

Point F is a representative point indicating the bucket position, and point F is placed on the bucket 4 according to the magnitude of the bucket angular displacement zEF G -γ (bucket) (angular displacement relative to the displacement of cylinder C3), which is set as a constant angle in advance. It is clear that the configuration and effects of the present invention will not change at all even if the above is replaced with any predetermined point. First, an operating device for carrying out the above-described control will be explained with reference to FIG.

The operation panel 6 includes dials for setting the slope of the excavated surface and an operation lever for specifying the excavation speed. The excavation speed is decomposed into a horizontal component and a vertical component depending on the slope of the excavation surface, and a voltage signal proportional to each speed component is sent to the calculation device 7.

The arithmetic unit 7 integrates each velocity component and calculates the bucket position F(
(x, y), and calculates the operation amount (input signal) of each hydraulic cylinder necessary to position the bucket at such a position.

These input signals are sent to the servo amplifier 8 and the angular displacement corresponding to the respective hydraulic cylinder displacement is detected by the detector 9.10.
FB is compared with the feedback signal FB obtained from the detection circuit 12 from . If there is an error between the input signal IP and the feedback signal FB, it is amplified by the servo amplifier 8, and the output is used to control the hydraulic control valves 13 and 14 that operate the boom cylinder C1 and the arm cylinder C2 in a direction that eliminates the error. drive In this way, the displacement of each hydraulic cylinder is controlled in accordance with the 12 input signals generated from the computing device 7, and automatic excavation is performed.

The operation panel 6 and calculation bag 7 shown in FIG. 2 will be explained in more detail.

The operation panel 6 is a part that generates voltage signals corresponding to the horizontal component υX, vertical component υy of the excavation speed, the slope angle φ of the excavation surface (see FIG. 1), etc. used by the arithmetic unit 7.

FIG. 5 shows the electric circuit inside the operation panel 6. The potentiometer P1 is linked to the operation lever 16 for giving the excavation speed, and the operational amplifier OF+ generates a voltage e1 proportional to the amount of operation of the lever 16. This voltage is reversed in sign by operational amplifier OP2 and becomes -e1, e
l and -01 are applied across potentiometer P2. Potentiometer P2 is for trigonometric function generation.If the voltage applied to the terminal is el, and the rotation angle of the input shaft is θ, then the two brushes have e 1 cos θ and e s si
A voltage corresponding to nθ appears. Therefore, if the dial 17 is set so that the rotation angle of the input shaft is equal to the slope angle φ of the excavation surface, the two brushes of the potentiometer P2 will have elcO8φ and ellll.
A voltage corresponding to nφ is generated, which has a horizontal component υX and a vertical component υy of the voltage corresponding to the excavation speed υ.

The potentiometer P3 is operated in conjunction with the potentiometer P2 by a dial 17 that sets the slope angle φ of the excavated surface, and a voltage corresponding to the angle φ is generated at its brush portion.

The three types of voltage signals generated in this manner are sent to the arithmetic unit 7 and used to calculate input signals for the control system.

In FIG. 1, the angles and lengths of each part are determined as follows.

/hoc=δ1 1BOX-δ2, II:0CD
=δ3 jFICH=δ4 These four corners are constant angles determined only by the dimensions of each part.

jD(1-α/AOB-β/EFG-γ These three angles are angular displacements corresponding to the displacements of the arm cylinder C2, boom cylinder C1, bucket) and cylinder C3.

Surface-e1 Tehyaku=h Fu-e3 Furthermore, QC,
CH, PQ, are horizontal lines OX, l! : Let the angles formed be positive in the direction shown in FIG. 1, and let ωl, ω2, φ respectively, and the angle at which FG becomes PQ be ψ.

First, a calculation circuit for obtaining input signals α and β required for positioning the bucket position F to a target position having coordinates (x, y) will be described. Using the symbols defined above, x, y,
The following formula holds between α, β, etc.

x = (J 1cowω1+Il'+cosωz+6
3slnω2(1)y = l 1sinωs + 1
12 sinωz-4-6acosω2(2), 1:β
−δ, −δ2 (3) ω2 − (ω1 + π) − α − δ3 − δ4 (4) Calculate using the steepest descent method to find the values of α and β as function values of x and y from the above equations. . Equation 1 is transformed as %(2) (5) (6) and becomes P: εX2+εy2 (7
), if we choose the values of α and β so that the value of P becomes minimum, we will find a solution such that εX and εy are zero, i.e., satisfying equations (1) and (2). can get.

Therefore, if we take α, β, and P as functions of time and take their differential values, we get the following (8). For P to be the minimum value, P −≦0 ・・・・・・・・・・・・・・・・・・・・・
・・・・・・・・・・・・・・・・・・・・・・・・
(9) The condition dt must always hold. Therefore, number one =
-K (εX busy εy 倶勺 (10) d
α dt α aα U= 1 ((ε knee + ε a) Tazoshi K>0...
・(11) It is sufficient if the condition of aεX ney dt flight aβ is satisfied. Here j-'-= hsinω1-/13coso)z
(12) aα ” ” =-# 2 (!O8ω2-e3!I+nω2
(13)) α Jgx (1,
i) Sa β Pregnancy - ε A + X (15) a
β. Therefore, equations (10) and (11) become d? −K[εX(εy+y)+εy(εx+x)l
(17) Formulas (1) to (4), (16), (1
7), α corresponding to the target position (x, y)
, β values are determined.

In order to move the target position (x, y) at a constant gradient (angle φ,), the voltages of the horizontal component υX and vertical component υy of the degree of excavation obtained from the operation panel 6 are determined by integrating them.

The above is summarized in one arithmetic circuit as shown in Fig. 3. The integral RiFf+, I2 is the part that calculates the target position (x, y) of the bucket position F from each component of the excavation speed, and the integrator 3.14 calculates the values on the right side of equations (16) and (17). This is the part that calculates α and β by integrating. Integrator ■3,
For the initial value of I4, the signals α and β obtained from the detector installed on the actual hydraulic excavator are used, and the integrators ■1 and I2 are used.
The initial values of x and y calculated by entering the above initial values of α and β into equations (1) to (4) are used. The arithmetic circuit shown in FIG. 3 can obtain the values of the input signals α and β when the bucket position F is linearly moved at a speed given from the operation panel 6. In the figure, A+-n0 is an adder, If
-I4 is an integrator, SC1 to S Ce is a code converter, M4
-M4 is a multiplier, and FG1 to FG4 are trigonometric function units.

Since the contents of the operation panel and the arithmetic unit have been clarified with reference to FIGS. 3 to 5, the operation of the automatic driving system according to the present invention will be explained in detail again.

The driver operates each hydraulic cylinder by normal manual operation and sets the bucket 4 at an arbitrary position (depending on the work) as the automatic operation starting point. At this time, the α and β voltage signals obtained from the detector are set as the initial conditions of the integrators 3 and I4 in FIG. Next, the slope of the plane to be excavated φ
When set with the dial 17 and operating the operating lever, voltage signals corresponding to each angle and horizontal and vertical components of the excavation speed proportional to the amount of lever operation are sent to the calculation circuit.

The arithmetic circuit calculates the bucket position at that time from the initial conditions set in the integrator, and calculates α required to excavate at a given speed along the slope φ set at that position as the excavation starting point. , β are calculated and sent to the servo amplifier 8.

On the other hand, detectors 9.1 installed in each part of the hydraulic excavator
0 always detects the current values of α and β, and the values are sent to the servo amplifier 8 as a feedback signal. The servo amplifier 8 calculates the deviation between the input signal iP and the feedback signal FB, amplifies it, and uses the amplified voltage to operate the hydraulic control valves 14 and 13 for operating the arm cylinder and boom cylinder, thereby generating α and β. control so that it always follows the input signal. Therefore, after the operator sets the required value with the dial on the operation panel 6, he only needs to give the excavation speed using the automatic operation lever, and each hydraulic cylinder will be automatically operated and straight-line excavation will be performed at the given speed. .

The above is the operation in the case of automatic operation, but such a hydraulic excavator must also be able to perform excavation work by normal manual operation. Therefore, a device that performs a switching operation between automatic operation and normal manual operation using the above-mentioned operating device will be described.

FIG. 6 shows an automatic driving device including a switching mechanism between manual operation and automatic operation, and the same reference numerals as those in the previously explained figures in the figure indicate the same parts. Pressure oil flowing into each hydraulic cylinder C1, C2, C3 is controlled by solenoid valves 21A, 21
The oil passages are switched by B and 21C, and in the case of manual operation, they are controlled by manual switching valves 22A, 22B, and 22C, and in the case of automatic operation, they are controlled by hydraulic control valves 13, 14, and 15. The solenoid valves 21A, 21B, and 2IC are always switched to the manual switching valves 22A, 22B, and 22C by springs, respectively, and only when current is applied to the hydraulic control valves 13, 14, and 15, respectively.
can be switched to the side. Switching of the solenoid valve is performed using a switch on the operation panel 6. That is, in addition to the circuit shown in Figure 5, there is another switch on the operation panel 6, and when that switch is operated at the start of automatic operation, the solenoid valve is switched in the direction in which the hydraulic control valve circuit is connected, and the other switches are switched in the direction in which the hydraulic control valve circuit is connected. In this case, a manual switching valve is connected. Therefore, the manual switching valve is normally in an operable state, and the excavator can be operated manually in exactly the same way as a general hydraulic excavator. Further, the automatic operation device operates only while the switch on the operation panel 6 is pressed.

Furthermore, calculation mode control of the calculation circuit is performed in synchronization with the switching of the hydraulic circuit as described above. That is, the four integrators 11 to 4 of the arithmetic circuits in FIG. 3 are in the reset state in which the computer 1 actually performs the integration operation and the state and initial conditions are set.

It is necessary to convert the calculation mode to , and this conversion is performed by turning on the switch on the operation panel 6, that is, synchronizing with the start of automatic operation, the computer enters the computer 1 state, and the beam is set in the normal manual operation state. In addition, in FIG. 3, A1 to A
+o is an adder, SC1 to 8Cs are code converters, M1 to M
4 is a multiplier, and FGJ to FG4 are trigonometric function calculators.

As described above, the manual operation function of the conventional hydraulic excavator is not impaired at all, and operation switching between automatic operation and manual operation can be easily performed with a single switch.

When performing straight-line excavation using the above-mentioned automatic operation device, as the excavation progresses, the arm cylinder C2 or the boom cylinder C1 reaches the end of its stroke, and straight-line excavation is no longer possible. Which cylinder reaches the stroke end first depends on the shape of the excavated surface and cannot be determined in advance. In any case, when one of the hydraulic cylinders reaches the end of its stroke, it is no longer possible to excavate in a straight line, so it is desirable that the automatic operation device automatically stop its operation when such a state is reached.

A device that performs this automatic stop will be described next.

Whether the hydraulic cylinder has reached the stroke end is determined by the output of the arithmetic circuit, that is, the input signals for α and β. Since the range of angular displacement in which α and β can move in response to the displacement of arm cylinder C2 and boom cylinder CI is determined, the input signals of α and β generated from the arithmetic circuit are their upper or lower limit values. It can be determined that the cylinder has reached the end of its stroke when it reaches . Therefore, it is sufficient to provide a circuit that compares the α and β input signals with their respective upper and lower limit values, and when any one point exceeds the limit, it is considered that that portion has reached the stroke end first. However, if you select the value set in the comparison circuit exactly equal to the limit value and perform automatic excavation from one stroke end of a hydraulic cylinder to the opposite stroke end, it is possible to There is a risk that the comparison circuit will operate.
The limit values set for each comparison circuit are a value slightly larger (by δ) than the respective upper limit and a value slightly smaller (by δ) than the lower limit. Thereby, the comparator circuit operates when the input signals α and β further exceed the upper or lower limit value, that is, when the input signals for each of the arm cylinder and boom cylinder exceed the end of stroke.

- When it is determined that the limit of the linear excavation range has been reached as described above, automatic excavation must be stopped accordingly. This corresponds to each solenoid valve 21 in FIG.
This is done by cutting off the current flowing through A, 21B, and 21C to switch the manual switching valves 22A, 22B, and 22C to the operating side, and then resetting the calculation mode of the calculation circuit from Compute to return to the manual operation state. The switching circuit of FIG. 6 also includes the above comparison circuit, the contents of which are as shown in FIG.

The four comparators 23A, 23B, 23C, and 23D determine whether the input signals α and β obtained from the arithmetic circuit exceed their respective upper limit values or lower limit values. The outputs of these comparison circuits are combined with the automatic operation start signal obtained from the switch PS on the operation panel 6, and a logic circuit determines whether the automatic operation state or the manual operation state is present. In the automatic operation state, the output of the logic circuit is amplified by the amplifier 24 to control the calculation mode of the calculation device 7 and at the same time operate the relay 26 for exciting the electromagnetic valve solenoid 25.

26R indicates a relay contact.

Both α and β are within the upper and lower limits, and a logical operation is performed so that when the switch PS of the operation panel 6 is on, the automatic operation state is set, and all other operations are set to the manual operation state. However, if the hydraulic cylinder reaches the end of its stroke and changes from automatic operation to manual operation, it will not return to automatic operation even if the switch PS on the operation panel 6 is kept in the on state. .

According to the present invention as described above, straight line excavation work such as slope forming work and horizontal surface excavation work at the bottom of a trench can be automatically performed by a hydraulic excavator, thereby eliminating the complexity of operation and further reducing the operating time. is shortened and work efficiency is improved. Moreover, the manual operation function is not impaired at all, and switching between automatic operation and manual operation can be easily performed with a single switch.

[Brief explanation of the drawing]

Figure 1 is a side view of the hydraulic excavator, Figure 2 is an explanatory diagram showing the outline of the automatic operation device according to the present invention, and Figure 3 is the input necessary to control the position of the arm tip in Figure 2. Fig. 4 is a calculation circuit diagram for obtaining the input signal necessary to control the attitude of the bucket shown in Fig. 2. Fig. 5 is a calculation circuit diagram for obtaining the input signals shown in Fig. 3 and Fig. 4. Fig. 6 is an explanatory diagram showing a switching device used to switch the automatic operation device according to the present invention to manual operation, and Fig. 7 is an electric circuit diagram inside the operation panel that generates the voltage signal necessary for performing the operation. FIG. 2 is an explanatory diagram showing a circuit for switching the automatic driving device between automatic driving and manual driving according to the present invention. 2...Boom 3...Arm 4...Bucket 6
...Operation panel 7...Arithmetic device 8...Servo amplifier 9-10...Detector 12...Detection circuit 13
~15... Hydraulic control... Constant voltage generator 20... Adder 21A, 21B, 21C... Solenoid valve 22A, 2
2B. 22C...Manual switching valve 23A, 23B, 23C, 2
3D... Comparator 24... Amplifier 25... Solenoid valve solenoid 26... Relay 26R... Relay contact C1... Boom cylinder C2... Arm cylinder C3... Bucket cylinder FB...Feedback signal IP...Input signal PI-P3...
Potentiometer OPI, OP2... operational amplifier 1
1~■4...Integrator PS...Push button switch procedure amendment (method) // 7 This month's f date in 1980 Mr. Haruki Shimada, Commissioner of the Patent Office 1, Indication of the case 1982 Patent t @ No. 50479 2. Name of the invention: Hydraulic excavator automatic driving device for linear excavation 3. Name of the person making the correction (552) Hitachi Construction Machinery Co., Ltd. Representative: Bunpei Nishimoto 4, Agent Address: Marunouchi, Chiyoda-ku, Tokyo, 100 Chome 5-1
Address: Hitachi, Ltd. Internal telephone: Tokyo 212-1111 (main representative) 7.1 =+ilt in "Brief explanation of drawings" is corrected as follows. ``Figure 1 is a side view of the hydraulic excavator, Figure 2 is an explanatory diagram showing the outline of the automatic operation device according to the present invention, and Figure 3 shows the input signals necessary to control the position of the arm tip in Figure 2. Figure 4 is an electrical circuit diagram of the operation panel that generates the voltage signal necessary to perform the calculations shown in Figure 3. Figure 5 shows how the automatic operation device according to the present invention is switched to manual operation. FIG. 6 is an explanatory diagram showing a switching device used in the present invention, and FIG. 6 is an explanatory diagram showing a circuit for switching the automatic operation device according to the present invention between automatic operation and manual operation. 2...Boom 3...Arm 4 ...Packet 6...Operation panel 7...Arithmetic unit 8...
Servo amplifier 9-10...Detector 12...Detection circuit 13-15...Hydraulic control valve 16...Operation lever 17...Dial 19...Constant voltage generator
20... Adder 21A, 21B, 21C... Solenoid valve 22A, 22B, 22C... Manual switching valve
23A, 23B, 23C, 23D... Comparator 24.
...Intensifier 25...Magnetic solenoid 26...
・Relay 26R...Relay contact C1...Boom cylinder C2...Arm cylinder C3...Packet cylinder FB...Feedback signal IF・
...Input signal P1-P3...Potentiometer O
PI, OF2...6i [Increase rlJ device 11-I4
...Integrator PS...Push button switch 179-

Claims (1)

[Claims] In a hydraulic excavator that carries out excavation work by pivoting a work attachment consisting of movable members sequentially and rotationally connected to a revolving body and operating hydraulic cylinders for operating each movable member, the slope φ of the excavation surface is set in advance. means for instructing the magnitude of excavation speed; means for detecting the operating position of each movable member; and positioning of the bucket at the position where linear excavation is to be performed based on the set values, indicated values, and detected values of each of the above-mentioned means. Linear excavation for a hydraulic excavator, characterized in that it is equipped with a calculation device that sequentially calculates the amount of operation of each hydraulic cylinder, and a means for controlling the movement of each hydraulic cylinder using the calculation results obtained from the calculation device as an input signal. Automatic driving device.