JPH0559883A - Direction control method for shield excavator - Google Patents

Abstract

PURPOSE:To turn a shield excavator without applying excessive load and displacement to the ground by using a control system automatically judging the quality of the turning radius in consideration of the soil property. CONSTITUTION:When a shield excavator is turned for an excavation, the turning radius R and the turning center C are inputted to a control device 14 via an input device 16. When the turning radius R set by an operator is judged satisfactory by the control device, a shield jack 9 is driven and controlled by a shield sequencer 18 for an excavation along a circular arc specified by this turning radius R. When it is displayed on a display 17 that the set turning radius R is inadequate, the operator cancels the previous turning radius and sets a new turning radius. When it is judged satisfactory, the shield jack 9 is driven and controlled for an excavation along the circular arc specified by the new turning radius.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the direction of a shield excavator, and when the shield excavator is excavating while making a turn, it does not apply an excessive load to the surrounding ground, and the turning resistance moment associated with the turn is provided. It is designed to be small.

[0002]

2. Description of the Related Art Tunnels such as subways, water and sewage systems, electric power, communications, common channels for gas, and underground passageways are often constructed by a shield construction method. If you use the shield method,
It is possible to construct a tunnel while safely excavating and lining the inside of the shield while preventing the surrounding ground from collapsing.

An outline of the mechanical construction and operation of the mud-type shield excavator will be described with reference to FIG. As shown in FIG. 1, the excavator main body 1 has a tubular shape, a bulkhead 2 serving as a partition is attached to a front portion thereof, and a rotary cutter 3 is attached to a front surface of the bulkhead 2.
A space between the bulkhead 2 and the rotary cutter 3 becomes a chamber 4, and the kneaded soil generated by kneading the pressurized / injected mud material and the cut soil is taken into the chamber 4. The kneaded soil is discharged by the screw conveyor 5.
At this time, the earth pressure on the front face of the face is detected by the earth pressure gauge 6.

The tail of the excavator body 1 is provided with a tail packing 7.
It is fitted to the existing ring 8 via. A plurality of hydraulic shield jacks 9 are arranged in the excavator body 1 along the circumferential direction. When propelling the excavator body 1, pressure oil is supplied to the shield jack 9 to extend the shield jack 9 and push the ring 8. By doing so, the excavator body 1 is propelled by the reaction force from the ring 8, and excavation is performed by the rotary cutter 3 during propulsion. When one ring has been dug, the excavation is stopped and the shield jack 9 is contracted, and a new segment is carried into the gap formed by the contraction by the erector to assemble the ring 8.

The shield excavator described above has its course adjusted so as to proceed along a predetermined planned line. That is, the position of the shield excavator is actually measured using a laser measuring device, a level meter, or the like, the deviation between the measured data and the planned line is calculated by a computer, and the course is adjusted so that this deviation becomes zero. The course adjustment is realized by changing the turning moment acting on the excavator body 1 by adjusting the pressure oil supplied to the plurality of shield jacks during the excavation.

That is, when the shield excavator excavates straight, the thrust of each shield jack is made equal, but when turning along a curved planned line, the thrust by the shield jack is biased to one side to give a turning force. There is. To be more specific, when the twelve shield jacks 9a to 9l are provided as shown in FIGS. 2A and 2B, for example, the thrust of the shield jacks 9a to 9f is set to zero and the shield jacks 9g to 9g. The thrust is generated by 9 l to generate the turning force.

[0007]

By the way, conventionally, the control for turning the shield excavator is manually performed by the operator's empirical judgment.
That is, FIG. 3 is a plan view showing the excavation state of the shield excavator.
Suppose that the shield excavator turns from the position I-1 to the position I, this means that the shield excavator has a turning radius R about the turning center C _i-1.
It means the same as going along the arc of the circle of _i-1 . Conventionally, the method of taking the above-mentioned arc has been arbitrarily selected based on the experience of the operator.

As described above, conventionally, the turning control is performed based on the experience of the operator. Moreover, the soil condition of the surrounding ground is not taken into consideration. Moreover, it is not clear what kind of turning resistance the ground excavator receives from the ground when turning. Therefore, if the operator excavates along an arc with a turning radius empirically selected, depending on the soil quality, an excessive load may be applied to the ground, which may damage the shield body or cause consolidation settlement when stress is released. there were.

In view of the above-mentioned conventional technique, the present invention provides a shield excavator direction control method capable of turning a shield excavator without giving an excessive load or displacement to the ground in consideration of the change and behavior of the ground. The purpose is to provide.

[0010]

According to the structure of the present invention for solving the above-mentioned problems, when a turning radius for defining a turning path is set, a displacement amount at each position of the shield excavator based on this turning radius and The slip amount is calculated, the relationship between the displacement amount and the ground reaction force and the relationship between the slip amount and the friction force are investigated in advance, and the ground reaction force corresponding to the calculated displacement amount is calculated using these relationships. In addition to the calculation, the frictional force according to the slip amount calculated is calculated, and the concentrated total thrust is calculated from the balanced total thrust that includes the calculated frictional force as a parameter along the axial direction of the shield excavator. The eccentricity, which is the distance between the point where the concentrated total thrust acts and the shaft center, is calculated from the balance equation of the moment acting on the shield excavator, which includes the thrust as a parameter, and the product of the concentrated total thrust and the eccentricity is within the allowable range. Within And, when the two conditions that the maximum value of the displacement amount is within the allowable range are satisfied, it is determined that the set turning radius is good, and the excavation is controlled along the turning path defined by the turning radius, When the above two conditions are not satisfied, it is determined that the set turning radius is inappropriate.

[0011]

In the present invention, the calculation is generally performed according to the following procedure to control the direction during turning. The course at the time of turning is defined and set by an arc of a circle having a turning radius R centering on the turning center C and the length on this arc. Predict the ground reaction force, deformation, frictional characteristics, etc. when excavating along the set turning path from the viewpoint of tera-mechanics (interaction between ground and machine) in consideration of the soil quality of the ground. (A) Predicted reaction force, deformation, friction, etc., (b) Concentrated total thrust F of the excavator, and an eccentricity amount m that the thrust action point on which the concentrated total thrust F acts is eccentric from the center of the excavator main body. ,
(C) With the set turning radius R and (d) each dimension of the excavator body as parameters, (e) the balance formula of the force along the axial direction of the excavator body and the turning moment around the turning center C. Create a balance formula. The concentrated total thrust F is obtained from the force balance formula, and the eccentricity m is obtained from the turning moment balance formula. It is determined whether the magnitude of the moment F · m, which is the product of F and m, is within the allowable range, and whether the lateral displacement of the excavator, that is, the amount of deformation applied to the ground is within the allowable range. When the above two conditions are cleared, the excavation is performed along the arc of the set radius R, and when the above two conditions cannot be cleared, the set radius is newly set.

[0012]

EXAMPLES Examples of the present invention will be specifically described below.
The method of the present invention is used for the shield excavator shown in FIG.

In the first embodiment, as shown in FIG. 4, a large number of earth pressure gauges 11 and friction force gauges 12 are provided on the peripheral surface of the excavator body 1. As shown in FIG. 5, an earth pressure gauge 11 for detecting earth pressure on the machine body peripheral surface, a friction force meter 12 for detecting friction force between the machine body peripheral surface and the ground, and an earth pressure gauge 6 for detecting earth pressure on the front face of the face. Each detection data is sent to the control device 14. Further, the control device 14 includes a detection device (laser measuring device, level meter, etc.) 15 for detecting the position and displacement of the shield excavator.
Sends the detection data. On the other hand, the input device 16 inputs the route data of the shield excavator to the control device 14, and the route data and the suitability of the set route are displayed on the display 17. The shield sequencer 18 controls the drive of the shield jack 9 so that the shield sequencer 18 digs along the route determined to be good by the control device 14. The control device 14,
The input device 16, the display 17, and the shield sequencer 18 are arranged in the excavator main body 1.

Proceeding while excavating the shield excavator
When, for example, from the position of I-1 to the position of I in FIG.
When turning up to, the operator must first make an arc.
Turning radius R that defines the specified turning path_i-1And turning center C
_i-1To the control device 14 by the input device 16 shown in FIG.
input. The control device 14 determines the set turning radius R_{i- 1}
When excavating along the arc specified by
Soil displacement, required shield thrust, etc.
To calculate and make a prediction (this prediction calculation method is
I will describe). And the predicted ground displacement is within the allowable range.
The ground will not be plastically deformed and an excavator will be generated.
When it is determined that the turning moment is within the allowable range
Is the turning radius R set by the operator_i-1Is good
To determine. In this way, the turning radius R_i-1Is good
When judged, this turning radius R _i-1Stipulated by
Shield sequencer 18
Thus, the drive control of the shield jack 9 is performed.

On the other hand, when excavating along an arc defined by the set turning radius R _i-1 , the control device 14 determines that the plastic deformation of the ground will occur or the turning moment is too large, and the set turning is set. The display 17 indicates that the radius R _i-1 is inappropriate. At this time, the excavation by the shield jack 9 does not start. In this case, the operator cancels the previous turning radius and sets a new turning radius. When it is determined that the new turning radius is good, the shield jack 9 is set so as to dig along the arc defined by the new turning radius.
Drive control is performed. Of course, when it is determined that the new turning radius is inappropriate, another new turning radius is set and a good turning radius is obtained.

Before describing the determination method by the control device 14, the coordinate system and the dimensions, the type of external force acting on the shield excavator, the displacement-earth pressure characteristic, and the sliding displacement frictional force characteristic are described. I will explain.

First, the dimensions and coordinate system will be described with reference to FIGS.
To do. As shown in the figure, L is the total length of the excavator body 1, and Q is the action.
Thrust is applied by the surface, that is, the shield jack 9.
Surface, l ₁Is the distance from the tail end of the main body 1 to the working surface Q, l₂
Is the distance from the tip of the main body 1 to the working surface Q, D is the excavator book
The diameter of the body 1, β is the angle of a point taken on the peripheral surface. Also
The three-dimensional coordinate system (x, y, z) seen from the excavator body 1
The central axis of the machine is the x-axis, and the lateral direction perpendicular to this is the y-axis.
The axis and the vertical direction are defined as the z axis. Origin O is x-axis and working surface
At the intersection with Q. Also, as shown in FIG.
The standard systems X, Y, and Z (Z is the direction perpendicular to the paper surface) are taken.

Further, as shown in FIG. 6, the concepts of concentrated total thrust F, eccentricity m, and thrust action point M are introduced. In other words, when turning, the turning behavior is considered by assuming that the total thrust F of the shield jack 9 acts concentrated on point M, and the distance between points M and O is taken as the eccentricity amount m. There is. Conversely, the concentrated total thrust F introduced as a concept
And the eccentricity amount m, the actual output patterns of the many shield jacks 9 can be obtained. In the determination method described later, the concentrated total thrust F acts only on the xy plane, in other words, the thrust action point M is a point that can move only on the y axis, and the description will proceed. Therefore, it is assumed that the shield excavator moves (yaws) only on the xy plane.

Next, referring to FIG. 7, various external forces acting on the shield excavator for excavating the ground are shown. In other words, is the driving force of the excavator, is the earth pressure on the front face of the face, is the earth pressure due to the overburden, is the ground reaction force due to the lateral displacement, and is the frictional force on the outer peripheral surface of the excavator body.

Next, the relationship between the lateral displacement S _y and the ground reaction force P _y will be described with reference to FIG. The lateral displacement amount S _y is a displacement amount (mm) along the y direction when the excavator main body 1 turns on the xy plane, and the ground reaction force P _y is the excavator main body 1
Is the reaction force (kgf / cm ² ) received from the ground along the y direction when is displaced in the y direction.

As shown in FIG. 8, the position of the body is stationary.
From the ground side (S_yGround reaction force increases if displaced to> 0)
Then, it eventually becomes a passive state and the ultimate ground reaction force P_ymaxWorks
It The direction away from the ground (S_yDisplace to <0)
And ground reaction force decreases and active earth pressure Q _y2Works.

The S _y -P _y characteristic curve shown in FIG. 8 varies depending on the soil quality. When the earth pressure gauge 11 is provided as shown in FIG. 4, the ground reaction force P _y at the time of displacement is measured by the earth pressure gauge 11 during actual excavation, the measurement data is taken in, and the figure is obtained from a large number of measurement data. The characteristic curve shown in 8 is made. The characteristic curve created in this way will be corrected by taking in new measurement data as the excavation progresses, and by so-called learning control, it will become more accurate depending on the soil quality actually excavated. .. First of the present invention
In the embodiment, employing the techniques we make the S _y -P _y characteristics by learning control.

The characteristic shown in FIG. 8, that is, S_yAnd P_ySeki
The coefficient can be expressed by a mathematical formula such as an exponential function.
Therefore, by using an excavator equipped with an earth pressure gauge 11, various types of soil
Of P _y-S_yBuild a database by accumulating characteristics
If you don't actually measure the reaction force, boring data and easy
P of the soil that is being excavated just by performing a simple hole loading test. _y
-S_yThe characteristic can be expressed by a mathematical formula. The present invention
In 2 examples, just by examining the soil quality, accumulation in advance
From the database_y-S_yNumerical expression indicating the characteristic (example
(For example, exponential function), and the lateral displacement S_yIn response
Ground reaction force P _yI am trying to ask.

Next, referring to FIG. 9, the slip displacement δ (x,
The relationship between y) and the frictional force f _x (f _y ) is shown. When the aircraft turns and slides in the x and y directions, the amount of slip is a few mm to a few cm
The frictional forces f _x and f _y change during the period up to, but in many cases, the frictional force becomes almost constant when the amount of slip exceeds a certain value.

The δ-f characteristic curve shown in FIG. 9 varies depending on the soil quality and vertical earth pressure. As shown in FIG. 4, earth pressure gauge 11
When equipped with the friction force meter 12, during actual excavation,
The frictional forces f _x and f _y are measured by the frictional force meter 12 and the measurement data is taken in, and a characteristic curve as shown in FIG. 9 is created from a large number of measurement data. The characteristic curve created in this way will be corrected by taking in new measurement data as the excavation progresses, and by so-called learning control, it will become more accurate depending on the soil quality actually excavated. ..
The first embodiment of the present invention employs a method of creating a δ-f characteristic by learning control.

The characteristic shown in FIG. 9 can be expressed by a simple mathematical expression if the slip start section is ignored. Therefore,
By excavator equipped with friction force meter 12, δ-of various soil types
If f characteristics are accumulated and a database is constructed, the δ-f characteristics of the excavated soil can be calculated by mathematical formulas without boring data being measured and boring data or simple hole loading tests. Can be shown. In the second embodiment of the present invention, only by inspecting the soil quality, a mathematical expression showing the δ-f characteristic is taken out from the database accumulated in advance,
The frictional force f _x f _y corresponding to the slip displacement δ is calculated.

Next, with reference to FIG. 10, the determination method of the control device 14 in the first embodiment of the present invention will be described.

In step 1 of FIG. 10, the turning center C _i-1 ,
When the turning radius R _i-1 is input, the lateral displacement amount S _y and the slip amount δ at each position of the excavator body 1 are geometrically determined by calculation (step 2).

The lateral displacement amount S _y using the measured data (FIG. 8)
The ground reaction force P _y is obtained from the above (step 3), and the frictional force f is obtained from the slip amount δ using the measured data (FIG. 9) (step 4).

From the balance formula of the force in the X direction, the concentrated total thrust F
Ask for. That is, F is obtained by solving the following equation (1) (step 5).

[0031]

[Equation 1]

The eccentricity amount m is calculated from the moment balance equation. That is, m is calculated by solving the following equation (2) (step 6). In the following equation (2), the first item is the turning moment, and the sum of the second, third, fourth and fifth items is the turning resistance moment.

[0033]

[Equation 2]

In step 7, it is judged whether or not the moment F · m, which is the product of F and m obtained from the equations (1) and (2), is within the allowable range. The allowable range is determined by the strength and propulsion force of the excavator body. Further, it is determined whether or not the maximum value of the lateral displacement is within the allowable range, for example, within the range α in FIG.
Within the range α, the ground will not be plastically deformed and will not adversely affect the ground. Range α depends on the soil type.

When the two conditions are satisfied in step 7, it is determined that the initial setting is good (step 8), and when the two conditions are not satisfied, the setting is performed again (step 9).

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, the earth pressure gauge 1 as shown in FIG.
1 and the friction force meter 12 are not used, the relational expression showing the S _y -P _y relation and the relational expression showing the δ-f relation are taken out from the database accumulated in advance,
The ground reaction force P _y corresponding to the lateral displacement amount S _y is calculated (step 3), and the frictional forces f _y and f corresponding to the slip amount δ are calculated.
_{Find x} (step 3). The other steps are the same as those in the first embodiment shown in FIG.

Here, an example of the relational expression (3) showing the relation between the lateral displacement amount S _y and the ground reaction force P _y is shown below.

[0038]

[Equation 3]

Next, the relational expression (4) showing the frictional force is shown below.

[0040]

[Equation 4]

[0041]

[Equation 5]

[0042]

[Equation 6]

[0043]

According to the present invention as described in detail with reference to the above embodiments, when the shield excavator turns, whether or not the turning radius is appropriate is determined in consideration of the soil quality. , The optimum turning radius can be taken without loosening the surrounding ground or applying an excessive load to the body of the shield excavator.

[Brief description of drawings]

FIG. 1 is a sectional view showing a shield excavator.

FIG. 2 is an explanatory diagram showing an arrangement and an output pattern of a shield jack.

FIG. 3 is an explanatory view showing a turning situation.

FIG. 4 is a perspective view showing an arrangement of an earth pressure gauge and a friction force meter.

FIG. 5 is a block diagram showing a connection state of various measuring instruments and control devices.

FIG. 6 is a perspective view showing dimensions and coordinates.

FIG. 7 is an explanatory diagram showing an external force acting on the excavator.

FIG. 8 is a characteristic diagram showing the relationship between lateral displacement and ground reaction force.

FIG. 9 is a characteristic diagram showing the relationship between sliding displacement and frictional force.

FIG. 10 is a flowchart showing the operation of the first embodiment.

FIG. 11 is a flowchart showing the operation of the second embodiment.

[Explanation of symbols] 1 excavator main body 6 earth pressure gauge 9 shield jack 11 earth pressure gauge 12 friction force meter 14 control device 15 position / displacement detection device 16 input device 17 display 18 shield sequencer R turning radius C turning center F concentrated total thrust m eccentricity M thrust acting point Q thrust acting surface O origin S _y lateral displacement P _y subgrade reaction δ sliding displacement f _x, f _y frictional force

Claims (1)

[Claims] 1. When a turning radius that defines a turning path is set, a displacement amount and a slip amount at each position of the shield excavator are calculated based on the turning radius, and the relationship between the displacement amount and the ground reaction force is calculated. , The relationship between the slip amount and the friction force is investigated in advance, and by using these relationships, the ground reaction force corresponding to the displacement amount calculated is calculated, and the friction force corresponding to the slip amount calculated by the calculation is calculated. The concentrated total thrust is calculated from the balance equation of the force along the axial direction of the shield excavator that includes the calculated frictional force as a parameter, and the balance of the moments acting on the shield excavator that includes the calculated total concentrated thrust as a parameter From the formula, find the amount of eccentricity, which is the distance between the point on which the concentrated total thrust acts and the shaft center, and the product of the concentrated total thrust and the eccentricity is within the allowable range, and
When the two conditions that the maximum value of the displacement amount is within the allowable range are satisfied, it is determined that the set turning radius is good,
A method for controlling a direction of a shield excavator, characterized by controlling to excavate along a turning path defined by the turning radius, and determining that the set turning radius is inappropriate when the two conditions are not satisfied.