JPS5836135B2 - Kutsusakuki ni Okeru Kutsusakufukasano Seigiyohouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling the depth of excavation in an excavator equipped with a plurality of articulated movable parts, such as a hydraulic shovel or a excavator.

FIG. 1 shows an example of an excavator embodying the present invention, which is constructed as follows.

Is Boom 1 a book? 3 via a rotating shaft 2, and an arm 5 is connected to the tip of the boom 1 via a rotating shaft 4.

A packet I is connected to the tip of the arm 5 via a rotating shaft 6.

The boom 1 is rotated by a boom cylinder C1 whose base end is supported by the main body 3, and the arm 5 is rotated by an arm cylinder C1 connected between the intermediate part of the boom 1 and one end of the arm 5.
The packet 7 is rotated by a packet cylinder C3 connected between the base end side of the arm 5 and the base side of the packet 7.

Excavation work is performed by rotating the boom 1, arm 5, and packet 7 using cylinders.

In this case, since the boom 1, arm 5, and packet 7 each move in an arc, considerable skill is required to operate the packet 7 so that the cutting edge of the packet 7 is at a constant depth, and it is necessary to improve the accuracy. Efficiency decreases.

In order to eliminate this drawback, we installed a simulator that performs operations similar to those of the boom 1, arm 5, and packet 7, and when the tip of the packet of the simulator reaches a certain depth, a signal is emitted so that the packet 7 Methods such as raising the boom 1 so that it does not fall below a certain depth are used.

However, this method has a limited accuracy due to the mechanism for driving the simulator, the limit switch mounting mechanism for the simulator to generate signals, etc.
Setting the depth is not easy0 An object of the present invention is to provide a method that allows easy setting of the depth of excavation and control of the depth of excavation with high precision.

The excavation depth control method for an excavator according to the present invention includes a plurality of articulated movable parts sequentially connected so as to rotate, and an actuator for actuating each articulated movable part. Operate the actuators of the jointed movable parts, detect the rotation angle of each jointed movable part with a detector, calculate the angle of each jointed movable part with respect to the horizontal plane from the detection angle of each detector, and calculate the angle of each jointed movable part with respect to the horizontal plane. The product of the sine and the length of each articulated movable part, the height from the ground of the rotation axis between the fixed part of the excavator body and the articulated movable part connected to it, and the set value of the excavation depth. Y is determined, and the actuator of the articulated movable part that is different from the operated articulated movable part is actuated according to the value of Y to cause vertical movement of the different articulated movable part until the value of Y is zero. First, the principle of this invention will be explained with reference to the diagram in FIG. 2.

The boom 8 corresponds to the boom 1 in FIG.
This is expressed by a straight line connecting the rotation axis 4 and the rotation axis 4.

Arm 9 corresponds to arm 5 in FIG.
This is represented by a straight line connecting the rotation axis 6 and the rotation axis 6.

Packet 10 corresponds to packet 7 in FIG. 1 and is represented by a straight line connecting rotary shaft 6 and the cutting edge of packet I.

The length of the boom 8 is l1, the length of the arm 9 is l2, the length of the packet 10 is l3, and the height of the rotating shaft 2 from the ground is y.
.

Let θ1 be the angle between the boom 8 and the horizontal such that the angle with the horizontal when the boom 8 is above the horizontal is positive and the angle with the horizontal when the boom 8 is below the horizontal is negative. , the angle between the extension line of the boom 8 and the arm 9 is θ2J-the angle between the extension line of the boom 9 and the packet 10 is θ3, and the height of the cutting edge of the packet 10 from the ground surface is y.
y=/1sinθ1+71!2sin(θ1−θ2)+
13sin(θ1-θ2-θ3)+yO.

Since the excavation depth becomes a constant value D at the point where y becomes -D, the point at depth D is expressed as y==-D.

Therefore, Y = l1 sin θ1 + l2 sin (
θ1-θ2)-}-l3sin(θ1-θ2-θ3)+
If yo+D, then when Y is positive, the excavation depth is shallower than D, when Y is zero, the excavation depth is exactly D, and when Y is negative, the excavation depth is deeper than D, so Y
The excavation depth can be controlled by determining .

Next, an example of an arithmetic device for calculating the above Y will be explained with reference to FIG.

The angle θ1 of the boom 8 is detected by a detector 11 such as a potentiometer attached to the rotating shaft 2 directly or via a coupling mechanism.

Since the mounting angle of this detector 11 does not correctly match the reference direction of θ2, the output of the detector 11 is applied to the correction circuit 12 for correction to obtain a correct value.

Similarly, the output of the detector 13 that detects the angle of the arm 9 is corrected by the correction circuit 14 to obtain θ2.

Further, the output of the detector 15 that detects the angle of the packet 10 is corrected by the correction circuit 16 to obtain θ2.

The output θ1 of the correction circuit 12 is applied to the sine circuit 17.

Since a sine circuit produces a value at its output that is proportional to the sine of its input, the output of sine circuit 17 is proportional to sin θ1.

The output of the sine circuit 17 is added to the potentiometer 18, and θ
Correlate the value of sin θ1 when 1 = 90° with the length greater than or equal to the longest length that occurs during the calculation, and calculate that value with 7?1
By dividing the pressure with the potentiometer 18 to the ratio of
The output voltage of the potentiometer 18 becomes a voltage corresponding to /1 sin θ1.

The output θ1 of the correction circuit 12 is also applied to the adder 19 along with the output θ2 of the correction circuit 14, and an operation is performed to subtract 02 from θ1 to produce θ1 - θ2 in the output of the adder 19, and the output is sent to the sine circuit 20. sin (θ1
-θ2) is obtained, and the output is applied to the potentiometer 21 to divide the pressure to a partial pressure ratio corresponding to l2.
2 sin (θ1 - θ2) is obtained. The output θ, - θ2 of the adder 19 is the output θ of the correction circuit 16.
3 is also added to the adder 22, and θ1θ2 to θ3
The output of the adder 22 is calculated to reduce θ1−θ2−
θ3 is generated, its output is applied to the sine circuit 23 to obtain a value proportional to sin (θ1-θ2-θ3), and the output is applied to the potentiometer 24 to divide the voltage into a voltage division ratio corresponding to l3. , A! 2 stn (θ1−θ2−
θ3) is obtained.

Output A of potentiometer 18, output l2sin (θ1-θ2) of potentiometer 21, output l3sin (θ1-θ2θ3) of potentiometer 24, y
The output y of the potentiometer 25 is divided to produce an output corresponding to o.

, and the output D of the potentiometer 26, which has been divided to produce an output corresponding to D, is added to the adder 2T to obtain the value Y at the output of the adder 27.

Normally, when excavating, the arm control lever 28 is operated and the arm cylinder C2 is actuated by the flow rate control mechanism 29 such as a directional switching valve to swing the arm 5 in FIG. 1 in the direction of the main body 3. Y output from adder 27 during excavation
If the value of Y is positive, the boom cylinder C1 is operated to lower the boom 1, and if the value of Y is negative, the boom is By operating the cylinder C1 in the direction of raising the boom 1, horizontal excavation to a depth D can be automatically controlled.

By excluding the control to lower the boom when the value of Y is positive, and only controlling to raise the boom 1 when the value of Y is negative, it is possible to excavate with a depth limit that does not excavate deeper than depth D. .

In the above control, if a servo valve or a proportional solenoid valve is used as the flow rate control mechanism 31 instead of the ON-OFF solenoid valve, the raising and lowering of the boom 1 can be controlled by proportional control, and even more precise horizontal control at depth D can be achieved. Excavation becomes possible.

Although an excavator equipped with three articulated movable parts, a boom 1, an arm 5, and a packet 7, has been described as an embodiment of the present invention, the present invention can also be applied to cases in which there are two articulated movable parts, or four or more articulated movable parts. The same can be applied.

According to the invention described above, setting of the excavation depth becomes extremely easy, and horizontal excavation to a constant depth or limitation of the excavation depth can be easily and accurately performed.

[Brief explanation of drawings]

Fig. 1 is a side view showing an example of an excavator implementing this invention, Fig. 2 is an explanatory diagram for explaining the principle of this invention, and Fig. 3 is a system diagram showing one embodiment of this invention. . 2, 4, 6...rotation axis, 8...boom, 9...arm, 10...packet,
11... Detector for detecting the angle of the boom, 12
, 14, 16... Correction circuit, 13...
Detector for detecting the angle of the arm, 15...Detector for detecting the angle of the packet, 17, 20, 23...
...Sine circuit, 18, 21, 24, 25, 26.
...Potentiometer, 19, 22, 27...
... Adder, 28 ... Arm operation lever 2
9...Flow rate control mechanism, 30...Servo amplifier, 31...Flow rate control mechanism, C1...
...Boom cylinder, C2...Arm cylinder.

Claims (1)

[Claims] 1. In an excavator equipped with a plurality of articulated movable parts sequentially connected so as to rotate, and an actuator that operates each articulated movable part, the actuator of at least one articulated movable part is actuated, and each joint The rotation angle of each articulated movable part is detected by a detector, the angle of each articulated movable part with respect to the horizontal plane is determined from the detection angle of each detector, and the product of the sine of the obtained angle and the length of each articulated movable part, A value Y is obtained by adding the height from the ground of the rotating shaft between the fixed part of the excavator body and the articulated movable part connected thereto, and the setting value of the excavation depth, and the above-mentioned operation is performed according to the value of Y. The actuator of the articulated movable part different from the operated articulated movable part is actuated to control the vertical movement of the different articulated movable part so that the value of Y becomes zero. How to control the depth of excavation.