SU1219754A1 - Method of monitoring the position of dragline excavator bucket - Google Patents

Description

112

The invention relates to the automatic measurement of the operational parameters of a dragline excavator during the performance of unmanned transport work and, in particular, is intended to control the position of the bucket in the plane of the boom.

The purpose of the invention is to simplify and increase the reliability of the determination of the danger zone where the bucket is located.

Indeed, from the condition of the equilibrium of forces and efforts in the hauling and lifting cables for point K (Fig. 1) along the axis O, the following equation can be written:

S cos (; -) S sin (90 ° -, -I J

(one)

for OY axis:

q) (t, -) - OS (, () sin () 4COS (Е; -,)

or

-Rc)

S sin i + Gg)

can be written (figure 1)

(five)

 t.- cos (fi,) (6)

IT.

(7)

H j ri

then expression (5) with regard to (7) can be rewritten as follows:

TO:

RP UK, - GS, F ,; sin (0 (8)

According to the theorem of sines, we have:

.l

E.

Tt

t .; (9)

- 1 sin (90 -%)

fhi

4i

(ten)

from where

sin g

(eleven)

sin (H + H /) ---- {- (12)

c Tr

4I

S .m (, - J P, (yO ° f ,,

 -c 2)

where S, S are the forces in the towing and lifting ropes;

f M the angles of gathering of the rope and hoisting rope from the guide pulleys; R. - bucket mass;

Р - Ц.С actual angle of the boom to the horizon; f f / - angles of the boom and turntable to the horizon. From FIG. 1 it follows that

. with

t - cos (., -y,) (3)

after substituting (3) into (2) and conversions, we have

 P.i

(four)

then

to: - | j5- .. -1N «1 Е .. (13) I d d | L

The current value of the abscess of a moving bucket in the plane of the boom is determined by the formula:

k, n -, c ± f., -) +

+ d. sin (f) (14)

Where

Lh,

- - f r, -)

jji

2L

(15)

and, f ",, + Кц" - o, i2e,., (16)

 fr; tKTi + T 0.49f., (17)

(18)

d 14, - L ,,.

lengths of overhanging and lifting parts

ropes;

lengths of lifting and traction chains;

radii of rotation of points

descending from the lifting and hauling rope pulleys;

3

L is the distance between the points of the descent and the hoisting ropes from the guide pulleys (conventionally the axis of the boom).

It should be noted that the value determined by formula (14) takes into account the actual angle of inclination of the plane of the platform to the horizon. those. The coordinate factor K takes into account the corresponding change in the allowable position of the bucket and boom depending on the value of € ,;

In excavators, for constructive reasons, the ratio of

h mox

 1.5 P,

those. The maximum force in the hoisting rope S is equal to one and a half times the mass (nominal value) of the loaded bucket. It follows that the limit value of the coordinate. coefficient is equal to

1 1.5

 0.666

Therefore, with K 0,666 protection should be triggered and disable the main drives.

It was established experimentally that when K; 0.75-0.7 (depending on the design features of the excavator) it is enough to give the excavator driver a signal that the bucket is in the danger zone and he manages to take the necessary measures to bring the bucket to a safe trajectory of movement.

FIG. 1 shows a design diagram for determining a coordinate factor; in fig. 2 is a block diagram of a system that implements a method for controlling the position of an excavator dragline bucket.

The proposed method includes the following basic operations: during the excavation process, the length of the overhanging part of the haul rope (|) is measured; measured during the excavation process, the length of the hanging part of the hoisting rope (RK); measure the angle of inclination of the plane of the turntable (f ,,,); determine the current abscissa value of the moving bucket in the boom plane () by formulas (14) - (18); determine the current value of the coordinate

9754

K coefficient ;; by the formula (13) i form the signal of the presence of the bucket in the danger zone

5 sign 03 1,

if K 0.75 - 0.7.

Thus, in the process of excavation, signals are generated that the bucket is in the danger zone. The driver, using these signals, promptly dumps the bucket into a safe area, thereby ensuring the safety of operation of the excavator. It should be noted that

5 according to the proposed method in determining the abscissa of a moving bucket U. | angle of inclination

turntable to horizonf ...

(so when determining the current

0 values of the coordinate coefficient K | 5 also takes into account the angle j. Since the boundary of the danger zone is defined at. O, then taking into account the actual values of the module and the sign of ygaf, j

5 allows you to generate a signal that the bucket is in the danger zone. Sign 03 1 is always at the calculated point of danger, eons, the value of which is determined in the interval 0.7-0.75. Thus, the angle of inclination of the turntable HP. affects the error in determining the boundary of the danger zone, i.e. the reliability of the method increases. An example of the technical implementation of the method is shown in FIG. 2

The system includes sensors of the length of the hanging parts of the lifting 1 and traction 2 ropes, sensor 3 of the angle of inclination of the plane of the turntable to the horizon, calculator 5, output indicator 5. Sensors 1-3 are connected to the corresponding inputs of the calculator 4, the output of which is connected to the input indicator 5.

The calculator 4 contains the following

five

Functional nodes: node 6 for determining the length of a branch of a hoisting rope, node 7 for determining the length of a branch of a haul rope, node 8 for summation

angles, node 9 for determining the projection of a branch of a hoisting rope, node 10 for determining the distance of the center of the body of the bucket from the conventional axis of the boom, node 11 for determining the abscissa of the bucket position, node 12 for determining

the value of the coordinate coefficient, the node 13 of forming the bucket signal in the danger zone. Output

node 6 is connected to the inputs of nodes 9, 10 and 12 ,. the output of node 7 is connected to the input of node 9, the output of node 8 is connected to the input of node 11, the output of node 9 is connected to the inputs of nodes 10 and 11, the output of node 10 is connected to the inputs of nodes 11 and 12. Other inputs of node 12 are connected to the output of node 11 and to the input of the node 9. The output of the node 12 is connected to the input of the node 13.

The system works as follows.

In the process of excavation, when the bucket is moved in the boom plane, the outputs of the sensors 1-3 and the input of the calculator 4 receive signals proportional to the lengths of the hanging parts of the lifting f and traction kg1 of the ropes, and the angle of inclination of the turntable y. Node 6 generates the output signal, proportional to the length f. branches of the hoisting rope (16) At the output of the node 7, a signal is formed proportional to the length of the branches of the haul rope (17).

At the output of node 8, a signal fj is generated, proportional to the sum of the angles of the boom E and the turntable i. As a result of entering the inputs of the node 9 values, e - L signal is formed, the proportion of the L, (15), which is fed to the inputs of nodes 10 and 11. At the output of node 10 a signal is formed, the proportions d; (18), and the output of node 11 is a signal proportional to

(14). At the exit node 12 vyrabaty

There is a signal proportional to the non-origin of the coordinate coefficient (13). Node 13 analyzes value K; and, if K: t is 0.75–0.7, the bucket is in the danger zone in the danger zone Sign, which arrives at output indicator 3.

The excavator driver, having received a signal that the bucket is in the danger zone, urgently switches the drives of the pulling and lifting gears to the modes, ensuring the unwinding of the pull and hoisting ropes from the drums of the respective winches.

Practical use of the method allows to increase the operational performance of the dragline both by reducing the likelihood of accidents (hitting the bucket on the boom, tightening the bucket attachment elements to the pickup unit or to the head pulley), and by moving

bucket with a maximum speed in the vicinity of the bucket stretching zone without the need for the excavator to continuously analyze the bucket and boom relative position and predict their relative position at the nearest time point. The latter circumstance, in addition, reduces the fatigue of the excavator driver, which also contributes to an increase in the operational performance of the excavator.

rig. Z

Claims (2)

METHOD FOR CONTROL POSITION OF THE EXCAVATOR-DRAGLINE BUCKET, including measuring the length of the hanging parts of the traction and lifting ropes, generating a signal for the bucket to be in the danger zone, characterized in that, in order to simplify and increase reliability, they measure the angle of the plane of the turntable, determine the current value of the abscissa of the moving platform bucket in the boom plane according to the formula ^U Ki = ^r n - ^L hi ^{COS (£} c) + + d, 'sin (6 _C + f _hi ), determine the current value of the coordinate coefficient fto to the formula _k = Jm. . __ZUiL 'd, L and the signal of the bucket in the danger zone is formed at the values K - <0.75 - 0.7, where s. t rct ^gt d; 2L ^ κτί + tut ⁺ 0.49g _Th , the length of the hanging parts of the hoisting and traction ropes; lengths of lifting and traction chains; radii of rotation of vanishing points from guide pulleys of hoisting and traction ropes; distance between vanishing points of traction and hoisting ropes from guide pulleys; boom and turntable angles. SU ... 1219754