TECHNICAL FIELD
[0001] The present invention relates to an apparatus for controlling an excavator such as
a small-bore-pipe excavator (trade name: Iron Mole) for burying water pipes, gas pipes
or the like.
BACKGROUND ART
[0002] In the field of underground excavators for performing tunnel excavation to bury underground
water pipes, gas pipes or the like, various controlling apparatuses have been developed
to automatically advance the excavation work in accordance with a planned line of
execution. As one of controlling apparatuses of this type, one disclosed in Japanese
Patent Application No. 332891/1991 is known, wherein, in an auger-type excavator of
a single-process construction method having actuators for direction correction, a
soil condition is inputted in advance, and the actuators are controlled by means of
fuzzy inference based on the inputted value and measured values of a positional offset,
an offset angle, thrust, and the like of the excavator.
[0003] However, the type of soil where the excavator is advanced is not actually fixed and
consecutively changes as the excavator is advanced. For this reason, if the actuators
are controlled primarily on the basis of the inputted soil condition, the precision
of advancing deteriorates, and there are cases where advancing itself becomes impossible.
Accordingly, it is desired to develop an apparatus capable of coping with the soil
condition which constantly changes, by ascertaining the consecutively changing soil
condition by using the inputted soil condition strictly as an initial value, and by
controlling the actuators on the basis of the ascertained soil condition. A first
aspect of the present invention has this as an object.
[0004] In addition, when the excavator is automatically operated, in light of improvement
of the reliability of the apparatus, it is required to be able to cope speedily with
a failure or the like by conducting a self-diagnostic check of the failure or the
like of each portion of the system. In the conventional practice, however, the situation
has been merely such that start-up inspection prior to the operation is conducted
at best. Yet, the more complicated the system of the excavator becomes, the more the
failure or the like occurs in each stage of operation including a stage prior to a
start-up, and the details of the failure or the like differ depending on each stage
of operation. An object of a second aspect of the present invention is to make it
possible to display a self-diagnostic check for each stage of operation and the details
of the check, and to perform the check appropriately and speedily, thereby remarkably
improving the reliability.
[0005] Furthermore, data on execution by the excavator is in many cases stored in a backup
memory so that its contents will not be lost even in the case of a power failure or
the like. In this case, as a method of its storage, it is desirable to ensure that
the essential operating efficiency will not be impaired. A third aspect of the present
invention is aimed at providing a method of storage which is suited to an auger-type
excavator of a single-process construction method.
DISCLOSURE OF THE INVENTION
[0006] Accordingly, in accordance with a first aspect of the present invention, there is
provided a controlling apparatus for an excavator having an excavating cutter at a
distal end thereof for excavating in the ground by rotating the cutter by means of
a cutter-rotating actuator and by advancing the excavator by means of an advancing
actuator, characterized by comprising:
input means for inputting a soil condition at a place where the excavator advances;
setting means for setting a reference number of revolutions of the cutter and a
reference advancing speed of the excavator in correspondence with the soil condition
inputted by the input means;
load-detecting means for detecting a load applied to each of the actuators;
number-of-revolutions controlling means for controlling the cutter-rotating actuator
so as to obtain the reference number of revolutions set by the setting means; and
speed-controlling means for controlling the advancing actuator so as to obtain
the reference advancing speed set by the setting means if it is detected by the load-detecting
means that the load on each of the actuators is within a predetermined range, and
for controlling the advancing actuator so as to decrease or increase the advancing
speed more than the reference advancing speed if it is detected by the load-detecting
means that the load on either of the actuators is outside the predetermined range.
[0007] In addition, in accordance with a second aspect of the present invention, there is
provided a controlling apparatus for an excavator having input means for inputting
data for operating the excavator, sensors for detecting states of various parts of
the excavator, actuators for driving the various parts of the excavator, a controller
for performing predetermined processing and controlling the driving of the actuators
on the basis of the data inputted by the input means and values detected by the sensors
so as to operate the excavator, and display means for displaying a result of processing
by the controller, wherein the excavator, the input means, the sensors, the actuators,
the controller, and the display means are connected by means of wire or radio transmission,
characterized in that:
if operation-stage data indicating a respective stage of operation is inputted
by the input means, or if the stage of operation is detected by a predetermined one
of the sensors, the controller conducts in correspondence with the inputted or detected
stage of operation a check of functions of the input means and each part of the controller,
an abnormality check of the values detected by the sensors on the basis of the values
detected by the sensors, a check of states of operation of the actuators on the basis
of the values detected by the sensors, or a check of a state of transmission of a
signal in the wire or radio transmission, and results of the checks are displayed
on the display means.
[0008] Furthermore, in accordance with a third aspect of the present invention, there is
provided a controlling apparatus for an excavator having an excavator which is advanced
in units of one stroke and in which a predetermined re-setup is provided after completion
of each stroke, sensors for detecting states of various parts of the excavator, an
actuator for advancing the excavator in units of one stroke, input means for inputting
data for operating the excavator, a controller for performing predetermined processing
and controlling the driving of the actuator on the basis of the data inputted by the
input means and values detected by the sensors so as to operate the excavator, and
a storage medium for storing results of processing by the controller, characterized
in that:
there is provided detecting means for detecting that the excavator has advanced
by one stroke; and that
the controller prepares execution data on the basis of the values detected by the
sensors, and each time the advance of the excavator by one stroke is detected by the
detecting means, the controller turns off the actuator and effects processing in which
the prepared execution data is written in the storage medium.
[0009] In accordance with the arrangement of the first aspect of the present invention,
the soil condition at the place where the excavator is advanced is inputted. Accordingly,
a reference number of revolutions of the cutter and a reference advancing speed of
the excavator are set in correspondence with the inputted soil condition. On the other
hand, a load applied to each actuator is detected. The cutter-rotating actuator is
controlled so as to allow the set reference number of revolutions to be obtained for
the cutter. If it is detected that the load on each of the actuators is within a predetermined
range, the advancing actuator is controlled so as to allow the set reference advancing
speed to be obtained for the excavator. However, if it is detected that the load on
either of the actuators is outside the predetermined range, this is the case where
the soil condition has changed, so that the advancing actuator is controlled so as
to decrease or increase the advancing speed more than the set reference advancing
speed. As the advancing actuator is thus controlled in correspondence with the consecutively
changing soil condition, it is possible to effect speed control capable of coping
with the change of the soil condition.
[0010] In a similar manner, in Claim 3, a change in the soil condition is ascertained from
the history of the position and attitude in the past, and control of direction correction
is effected correspondingly. In Claim 4, a pinch valve is controlled in correspondence
with the change in the soil condition, and, in Claim 5, water injection is controlled
in correspondence with the change in the soil condition.
[0011] In addition, in accordance with the second aspect of the present invention, operation-stage
data indicating a respective stage of operation is inputted by the input means, or
is detected by one of the sensors. In correspondence with the details of the inputted
or detected stage of operation, the controller conducts a check of functions of the
input means and each part of the controller, an abnormality check of the values detected
by the sensors on the basis of the values detected by the sensors, a check of states
of operation of the actuators on the basis of the values detected by the sensors,
or a check of a state of transmission of a signal in wire or radio transmission, and
results of the checks are displayed on the display means. Thus, checks are conducted
appropriately and speedily.
[0012] Furthermore, in accordance with the third aspect of the present invention, the advance
of the excavator by one stroke is detected, and each time the advance of the excavator
by one stroke is detected, the controller turns off the actuator and effects processing
in which data on execution during the advance by one stroke on the basis of the values
detected by the sensors is written in a storage medium. As a result, the execution
data for each stroke in the auger-type excavator of a single-process construction
method is stored consecutively during re-setups during which advancing is not effected,
so that the operating efficiency of the excavator is not impaired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
Fig. 1 is a diagram illustrating a horizontal cross section of a small-bore-pipe excavator
applied to an embodiment of a controlling apparatus for an excavator in accordance
with the present invention;
Fig. 2 is a block diagram illustrating a configuration of the controlling apparatus
in accordance with the embodiment;
Fig. 3 is a block diagram illustrating a configuration of a device for processing
execution data in accordance with the embodiment;
Figs. 4a and 4b are flowcharts illustrating a processing procedure of complex control
in accordance with the embodiment;
Fig. 5 is a flowchart illustrating a processing procedure of a blockage canceling
routine in accordance with the embodiment;
Fig. 6 is a flowchart illustrating a processing procedure of a direction correcting
routine in accordance with the embodiment;
Fig. 7 is a diagram used to explain calculation for determining an advancing speed
of the excavator in accordance with the embodiment;
Fig. 8 is a graph illustrating a change over time of a torque applied to a cutter
and a screw of the excavator in accordance with the embodiment;
Figs. 9a and 9b are flowcharts illustrating a processing procedure of processing of
a self-diagnosis and a malfunctional warning in accordance with another embodiment;
and
Fig. 10 is a flowchart illustrating a processing procedure of execution-data recording
processing in accordance with the embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
[0014] Referring now to the drawings, a description will be given of the embodiments of
a controlling apparatus for an excavator in accordance with the present invention.
[0015] Fig. 1 shows a horizontal cross section of a small-bore underground excavator 1 (hereafter
simply referred to as the "excavator 1") which is applied to the embodiment. Fig.
2 shows a block diagram of a configuration of a controlling apparatus of the embodiment.
Fig. 3 shows a block diagram of a device for analyzing execution data. It should be
noted that the excavator 1 functions as a leading pipe for a pipe to be buried, such
as a gas pipe.
[0016] As shown in these drawings, a laser theodolite 2 is disposed in a starting shaft
HL, whereby the present position and the present attitude angle of the excavator 1
are detected in correspondence with an irradiating position of a laser beam L which
is emitted toward a laser target 3 in the excavator 1. It should be noted that the
details of the position and attitude angle through the irradiation with this laser
beam are publicly known through, for instance, Japanese Patent Application No. 312199/1989
filed by the present applicant, and since they are not directly related to the main
gist of the present invention, description thereof will be omitted.
[0017] In Fig. 1, a cutter head 4 is disposed at a distal end of the excavator 1 in such
a manner as to be capable of being swung by a direction-correcting cylinder 5 which
is oriented to head toward upper and lower, and left and right directions, and its
swinging angle is detected by a proximity sensor 6. The angle detected by the proximity
sensor 6 is fed back to a leading-pipe controller 7, which controls the driving of
the direction-correcting cylinder 5 via a direction changeover valve 8 (see Fig. 2).
A cutter 9 is disposed at a distal end of the cutter head 4, and excavation is effected
as this cutter 9 rotates. The cutter 9 is formed integrally with a screw 10 (a so-called
auger) arranged in the longitudinal direction of the excavator 1, and this screw 10
serves to discharge in the rear direction the earth and sand at a working face excavated
by the cutter 9 as the screw 10 rotates together with the cutter 9.
[0018] The screw 10 is covered with a casing 11, and the removed earth and sand passes through
a passage 12 between the casing 11 and the screw 10. A pinch valve 13 for changing
the cross-sectional area of the passage 12 in correspondence with the pressure of
air applied is disposed midway in the passage 12.
[0019] In addition, an unillustrated water injection port is provided in the passage 12
forwardly of the pinch valve 13, and a slurry material or water is injected into the
passage 12 through this water injection port. The slurry material or the like is fed
to the water injection port by means of a water-injection changeover valve 14 (see
Fig. 2) disposed on the ground, for instance. When the water-injection changeover
valve 14 is operated and the slurry material is poured into the passage 12, the removed
sandy soil is set in the form of a slurry, so that the removed soil can pass through
the passage 12 without applying an excessively large load onto the screw 10. Similarly,
when the water-injection changeover valve 14 is operated and water is injected into
the passage 12, the removed soil is made aqueous when the removed soil is viscous,
so that the discharged soil can pass through the passage 12 without applying an excessively
large load onto the screw 10.
[0020] In the starting shaft HL, a pressing plate 15 formed integrally with the excavator
1 is disposed in such a manner as to be movable in the longitudinal direction of a
reaction-force bar 16. The pressing plate 15 is driven by an advancing cylinder 17
in the leftward direction as viewed in the drawing so as to advance the excavator
1. Here, the process in which the advancing cylinder 17 moves as far as it can reach
in the longitudinal direction of the reaction-force cover 16 is referred to as "one
stroke." When the excavator 1 is advanced by one stroke, a predetermined re-setup
is carried out in the starting shaft HL so as to advance the excavator 1 again by
another stroke. It should be noted that, depending on the type of excavator, there
are cases where a pipe to be buried is connected to the rear of the excavator after
completion of one stroke, and there are cases where the pipe to be buried is connected
after a plurality of strokes (e.g., two and a half strokes).
[0021] Meanwhile, a hydraulic motor 18 is disposed in the starting shaft HL, and as this
hydraulic motor 18 is driven, the screw 10 and the cutter 9 are rotated by means of
a predetermined transmitting mechanism.
[0022] In Fig. 2, an inverter motor 19 is a driving source of a hydraulic pump 20, and pressure
oil discharged from this hydraulic pump 20 is supplied to a group of hydraulic valves
21. The group of hydraulic valves 21 is mainly comprised of an advancing-jack changeover
valve 22 and a cutter-motor changeover valve 23. As the advancing-jack changeover
valve 22 and the cutter-motor changeover valve 23 are respectively operated as required,
the pressure oil is supplied to the advancing cylinder 17 and the hydraulic motor
18 for driving the cutter 9 and the screw 10, and they are driven.
[0023] Meanwhile, an air compressor 24 is a driving source of a pneumatic circuit, and air
discharged from this air compressor 24 is supplied to a group of pneumatic valves
25. The group of pneumatic valves 25 is mainly comprised of a pinch-valve-pressure
controlling valve 26, the aforementioned water-injection changeover valve 14, and
a pin-withdrawing changeover valve 27. Of these valves, when the pinch-valve-pressure
controlling valve 26 is operated, air of a predetermined pressure is applied to the
pinch valve 13, thereby changing the cross-sectional area of the aforementioned passage
12. In addition, when the water-injection changeover valve 14 is operated, water or
the slurry material is supplied to the passage 12, as described above, by means of
a pump 28 for water or a slurry material. Further, when the pin-withdrawing changeover
valve 27 is operated, a cylinder 29 for a re-setup is driven, whereby a re-setup after
completion of one stroke is effected. A lubricant pump 30 is provided for supplying
a lubricant to the surface of the excavator 1, and the lubricant is discharged to
the surface of the excavator 1 through a lubricant discharging port 31 (see Fig. 1)
during advancing, thereby allowing advancing to be effected smoothly.
[0024] Oil/air pressure sensors 32 are pressure sensors which are disposed in major portions
of the hydraulic circuit and the pneumatic circuit described above.
[0025] An operation panel 33 is located at a place which facilitates operation by an operator
in the starting shaft HL or on the ground, and is comprised of an operation panel
controller 34 which is mainly composed of a CPU and a memory; an input device 35 constituted
mainly by a keyboard; a display 36 such as a CRT having a display screen; an IC card
reader/writer 38 for writing in and reading from an IC card 37; and a warning lamp
39 which informs the operator to the effect that the excavator is being advanced as
the warning lamp 39 flashes.
[0026] The operation panel controller 34 has an input/output board 40, through which signals
from the various sensors are inputted and control signals for the various actuators
described above are outputted. Namely, detection signals from the oil/air pressure
sensors 32, together with failure signals, are inputted to the controller 34; a control
signal is outputted to the inverter motor 19; control signals are outputted to solenoids
of the group of pneumatic valves 25 and the group of hydraulic valves 21; and detection
signals concerning the position and attitude angle from the laser target 3, together
with error signals, are inputted to the controller 34. Then, the leading-pipe controller
7 is controlled via the input/output board 40, and at the same time error signals
are inputted to the controller 34. Further, a signal for flashing the warning lamp
39 is outputted via the input/output board 40, a control signal for writing is outputted
to the IC card reader/writer 38, and the contents which have been read are inputted
to the controller 34.
[0027] The input device 35 is for inputting data for operating the excavator 1 by means
of the keyboard, and the data is fetched into the controller 34. The controller then
displays a predetermined result of processing on the display 36, thereby imparting
necessary information to the operator.
[0028] Hereinafter, a description will be given of processing which is executed by the CPU
of the operation panel controller 34. It should be noted that it is assumed that a
processing program is stored in the memory of the CPU, and is executed as the operator
performs a keying operation on the keyboard, as required.
[0029] If it is assumed that the data on execution by the excavator 1 is stored in the IC
card 37, the operator is able to remove the IC card 37, carry it, and load it into
an IC card reader/writer 41 installed in a building for analyzing the execution data,
as shown in Fig. 3. Then, the operator is able to analyze the execution data by using
a general purpose computer comprising a personal computer 42, a floppy disk 45, a
floppy disk drive 44, and a printer 43.
♢ Complex Control of the Excavator
[0030] When a "start of execution of complex control" is instructed through the keying operation
on the keyboard, the CPU of the operation panel controller 34 starts the processing
shown in Figs. 4a and 4b. It should be noted that it is assumed that the execution
of this processing is started at the stage of an advancing start after the excavator
1 is set in the starting shaft HL.
[0031] First, data on the soil condition at the place where the advancing of the excavator
1 is carried out is inputted by means of the input device 35. Here, it is assumed
that the soil condition data referred to includes data which literally represents
the type of soil, indicating that the soil at the working face is sand, sandy soil,
clayish soil, or the like, and in a case where water is contained at the working face,
the soil condition data includes at least data on the pressure of water acting on
the front face of the excavator 1 (cutter 9), i.e., the so-called water pressure (Step
101).
[0032] Then, a determination is made as to whether or not predetermined control is to be
effected, depending on the details of the inputted soil condition data.
[0033] Namely, if the type of soil is sand or sandy soil, and if the water pressure is equal
to or greater than a predetermined threshold value, this condition is classified as
a soil condition (1). Then, a determination is made that control is to be executed
for varying the cross-sectional area of the passage 12 by means of the pinch valve
13 (hereafter this control will be referred to as "pinch valve control"), and a determination
is made that control is to be executed for supplying the slurry material to the passage
12 by means of the water-injection changeover valve 14. As a result, the water-injection
changeover valve 14 is operated, and the slurry material is supplied to the passage
12 to set the removed sandy soil in the form of a slurry, so that the removed soil
can pass through the passage 12 without applying an excessively large load onto the
screw 10 (Step 102).
[0034] Meanwhile, if the type of soil is clayish soil, and if the water pressure is smaller
than the aforementioned threshold value, this condition is classified as a soil condition
(3). Then, a determination is made that the aforementioned pinch valve control is
not to be executed, and a determination is made that control is to be executed for
supplying water to the passage 12 by means of the water-injection changeover valve
14 (hereafter this control will be referred to as "water injection control"). As a
result, the air pressure at the pinch valve 13 thereafter remains zero, so that the
cross-sectional area of the passage 12 becomes maximum (Step 104).
[0035] On the other hand, in the case of a soil condition which belongs to neither of the
aforementioned soil conditions (1) and (3), that soil condition is classified as a
soil condition (2). Then, a determination is made that neither the pinch valve control
nor the water injection control is to be executed. As a result, the cross-sectional
area of the passage 12 becomes maximum, and no water is supplied to the passage 12
(Step 103).
[0036] Next, a reference number of revolutions, n, of the cutter 9 is set in correspondence
with the details of the inputted soil condition data. This is based on the fact that,
if the soil differs, the relative difficulty of excavation differs, and the number
of revolutions of the cutter 9 needs to be changed correspondingly. The numbers of
revolution, n, corresponding to the types of soil are stored in the memory in advance,
and a corresponding n is read out. It should be noted that data representing the reference
number of revolutions, n, corresponding to the soil at the site may be directly inputted
from the input device 35 (Step 105).
[0037] Next, the advancing speed v of the excavator 1 is similarly set in correspondence
with the details of the soil condition data. This is also based on the fact that,
if the soil differs, the relative difficulty of advancing differs, and the advancing
speed v needs to be changed correspondingly. Here, the following relation holds with
respect to a cross-sectional area of excavation, i.e., an area A of the cutter 9,
a cross-sectional area a of the screw 10, a pitch l of the screw 10, and the advancing
speed v:
where k is a coefficient.
[0038] Accordingly, the coefficient k is set as shown below in correspondence with the soil
conditions (1), (2), and (3):
♢ In the case of the soil condition (1): k = 1 (Step 106).
♢ In the case of the soil condition (2): k is set in the range of 0 < k < 1, and in
the vicinity of an intermediate value therebetween (Step 107).
♢ In the case of the soil condition (3): k is set in the range of 0 < k < 1, and at
a value smaller than in the case of the soil condition (2) (Step 108).
[0039] Then, the coefficient set in Steps 106 to 108 is substituted in Formula (1) above
to determine the reference advancing speed v. It should be noted that, as the reference
advancing speed v, a value corresponding to the type of soil at the site may be inputted
directly from the input device 35. The reference advancing speed v thus obtained changes
in correspondence with the change at the working face as the excavator advances (Step
109).
[0040] Advancing is subsequently started (Step 110), and in the case of the soil condition
(1), i.e., if it is determined that the pinch valve control is to be executed, the
reference pressure of the pinch valve 13 is set to a predetermined value p. Here,
it is assumed that the pinch-valve reference pressure p is set by being classified
into small groups in correspondence with the details of the inputted soil condition
even in the same soil condition (1). It should be noted that the pinch-valve reference
pressure p corresponding to the type of soil at the site may be inputted directly
from the input device 35 (Step 111).
[0041] As advancing is started, measured values from various sensors are consecutively inputted
(Step 112), and the various actuators are controlled. Here, the reference number of
revolutions, n, set in Step 105 above is set as a targeted value of the number of
revolutions of the cutter 9, and the hydraulic motor 18 is controlled in such a manner
that the number of revolutions is maintained constantly at this targeted value. In
addition, the reference advancing speed v set in Step 109 above is set as a targeted
value of the advancing speed, and the advancing cylinder 17 is controlled in such
a manner that the advancing speed is maintained constantly at this targeted value
(Step 113). Additionally, in the case of the soil condition (1) in which the pinch
valve control is effected, the reference pressure p set in Step 111 above is set as
a targeted value of the pressure of the pinch valve 13, and the pinch valve 13 is
controlled in such a manner that the pressure is maintained constantly at the reference
pressure p (Step 114).
[0042] Next, a determination is made as to whether or not a rotation stall has occurred
at the cutter 9 on the basis of the detection signal from the sensor for detecting
the torque of the cutter 9, i.e., a load T, among the oil/air pressure sensors 32.
Here, Fig. 8 illustrates the relationship between the time t and the torque T of the
cutter 9. The torque T rises from the start of rotation, and, in a steady state, the
torque fluctuates with a predetermined width of torque fluctuation. In this case,
the sensor measures a mean value of the width of torque fluctuation. In due course
of time, when the removed soil is stuck in the passage 12, and the passage 12 is blocked,
a rotation stall occurs in the cutter 9 and the screw 10. This causes the torque T
to reach the relief pressure, thereby making it impossible to excavate and remove
the soil. Therefore, when the measured torque T reaches the predetermined threshold
value or more, a determination is made that an rotation stall has occurred (Step 115).
[0043] If it is determined that the torque T is equal to or greater than the aforementioned
threshold value (YES in the determination in Step 115), the operation proceeds to
the "blockage canceling routine" shown in Fig. 5 so as to avoid a situation in which
excavation or removal of soil becomes impossible (Step 116).
[0044] In the "blockage canceling routine," control is first effected to completely stop
the advancing of the excavator 1 and the rotation of the cutter 9, thereby preventing
the aggravation of the situation (Step 201). Subsequently, in the case of the soil
condition (1) in which the pinch valve control is effected, the pinch valve 13 is
controlled in such a manner that the cross-sectional area of the passage 12 becomes
minimum (Step 202). Then, the removal of the filled earth and sand is promoted by
controlling the rotation of the screw 10 in the forward or reverse direction, as required
(Step 203). Subsequently, the rotation of the screw 10 is set in the forward direction
(Step 204), and a determination is made as to whether or not a rotation stall has
occurred again (Step 205). As a result, if the rotation stall has been overcome (NO
in the determination in Step 205), the pinch-valve reference pressure is reset in
such a manner as to be greater than the reference pressure p set in Step 111, and
control is effected such that the cross-sectional area of the passage 12 becomes smaller
in correspondence with the reset pressure. In other words, a measure is provided to
ensure that the rotation stall will not occur again (Step 206). Then, the stoppage
of the advancing of the excavator 1 and of the rotation of the cutter 9 is canceled,
and advancing is resumed (Step 207).
[0045] Meanwhile, if the rotation stall has not yet been overcome (YES in the determination
in Step 205), the rotation is stopped again, and similar processing is repeatedly
executed.
[0046] On the other hand, in the cases of the soil conditions (2) and (3) in which the pinch
valve control is not executed, this is the case where the removed soil is stuck even
when the cross-sectional area is maximum, so that the screw 10 is moved in and out,
i.e., is moved relatively in the longitudinal direction of the excavator 1, so as
to remove the earth and sand (Step 208). The rotation of the cutter 9 is then turned
on (Step 209). Thereafter, in the same way as in the case of the soil condition (1),
a determination is made as to the presence or absence of the occurrence of a rotation
stall (Step 205), and if the rotation stall has been overcome, advancing is resumed
(Step 207).
[0047] After completion of the "blockage canceling routine," the operation returns to Step
117 to determine whether or not one stroke has been completed, i.e., whether or not
the pressing plate 15 has moved as far as it can reach in the longitudinal direction
of the reaction-force bar 16. The completion of one stroke may be detected by a predetermined
sensor, and the determination may be made from a detection signal therefrom. Alternatively,
the operator may enter data representing the "completion of one stroke" by means of
the keyboard, and the determination may be made from that input data. If one stroke
is completed (YES in the determination in Step 117), advancing is stopped, and a re-setup
such as the connection of a pipe to be buried to the rear of the leading pipe 1 is
required, so that this processing which is required only during the execution of advancing
ends.
[0048] Meanwhile, if it is determined that one stroke has not yet been completed (NO in
the determination in Step 117), the operation returns to Step 112, and processing
such as the inputting of measured values of the respective sensors is repeatedly executed.
[0049] Now, if it is determined in Step 115 that a rotation stall has not occurred, processing
corresponding to the soil condition (1), (2) or (3) is executed without executing
the "blockage canceling routine."
[0050] First, in the case of the soil condition (2) in which neither the pinch valve control
nor the water injection control is executed, only the control for varying the reference
advancing speed v (hereafter this control will be referred to as the "advancing speed
control") is carried out in correspondence with the situation at the working face
which changes as the excavator advances. Namely, on the basis of a detection signal
from a sensor for detecting the thrust F of the excavator 1 among the oil/air pressure
sensors 32, a determination is made as to whether or not the thrust F is equal to
or greater than a preset upper limit, or equal to or less than a preset lower limit.
Meanwhile, a determination is made as to whether or not the detected torque T is equal
to or greater than a preset upper limit, or equal to or less than a preset lower limit.
[0051] Therefore, if it is determined that the detected torque T has become equal to or
greater than the upper limit, or the detected thrust F has become equal to or greater
than the upper limit (YES in the determination in Step 118), this is the case where
the load on the excavator 1 is large and excavation is difficult. Accordingly, the
reference advancing speed is reset to a value smaller than the reference advancing
speed v set in Step 109 above, and the advancing speed of the excavator 1 is maintained
constantly at this reset reference advancing speed v (Step 119). Then, the operation
proceeds to a "direction correcting routine" which is shown in Fig. 6 and will be
described later, so as to control the driving of the direction-correcting cylinder
5 to allow the excavator 1 to advance in a direction along a reference planned line
(Step 120).
[0052] On the other hand, if it is determined that the detected torque T has become equal
to or less than the lower limit, or the detected thrust F has become equal to or less
than the lower limit (YES in the determination in Step 121), this is the case where
the load on the excavator 1 is small, and there is leeway in advancing. Hence, the
reference advancing speed is reset to a value greater than the reference advancing
speed v set in Step 109 above, and the advancing speed of the excavator 1 is maintained
constantly at this reset reference advancing speed v (Step 122). Then, the operation
proceeds to the aforementioned "direction correcting routine" (Step 120).
[0053] Furthermore, if it is determined that the detected torque T is in a range greater
than the lower limit and smaller than the upper limit, and that the detected thrust
F is in a range greater than the lower limit and smaller than the upper limit (NO
in both determinations in Steps 118 and 121), this is the case where advancing is
being effected smoothly at the reference advancing speed v set in Step 109 above.
Hence, the set reference advancing speed v is kept as it is, and the operation proceeds
to the aforementioned "direction correcting routine" (Step 120).
[0054] The "direction correcting routine" shown in Fig. 6 is basically similar to the direction
control disclosed in Japanese Patent Application No. 179641/1990 filed by the present
applicant, but technically differs from the same in that a targeted attitude angle
is determined on the basis of the history of direction correction in the past.
[0055] That is, at the laser target 3, the consecutive attitude angle of the excavator 1
from the advancing start to the present is detected, and is consecutively stored in
the memory. In addition, the consecutive position of the excavator 1 is also detected,
a deviation of this consecutive position from a consecutive targeted position is determined,
and a consecutive positional offset is stored. Further, an average value of the consecutively
detected attitude angles is calculated. In addition, an amount of change of the consecutive
positional offset is calculated (Step 301). Then, a counterbalancing attitude K (°)
required for the straight advance of the excavator 1 is calculated on the basis of
the details calculated in Step 301 (Step 302).
[0056] Meanwhile, the present position of the excavator 1 is obtained on the basis of an
output signal from the laser target 3, and a deviation of this present position from
a present targeted position is obtained as a present positional offset H (Step 303).
Then, from the attitude K calculated in Step 302 and the present positional offset
H calculated in Step 303 and by using f( ) as a predetermined function (which may
be a constant), a present targeted attitude angle ϑ
m is set in accordance with the following Formula (2):
[0057] In addition, the present attitude angle of the excavator 1 is obtained from the output
signal from the laser target 3, and an offset angle ϑ
n of the present attitude angle with respect to a present targeted advancing direction
(planned line) is calculated (Step 305). Then, a deviation ϑ
m - ϑ
n of the targeted attitude angle ϑ
m obtained in Step 304 from the offset angle ϑ
n obtained in Step 305 is calculated (Step 306).
[0058] The targeted attitude angle ϑ
m calculated in Step 304 is consecutively stored in the memory from the advancing start
to the previous time (m - 1). Similarly, the offset angle ϑ
n calculated in Step 305 is consecutively stored in the memory up to the present (n).
Accordingly, deviations of the previous targeted attitude angle ϑ
m-1 from the present offset angle ϑ
n are added (integrated) up to the present as

. The aforementioned integral value means a "direction-correcting speed" (Step 307).
[0059] Then, an amount of driving the direction-correcting cylinder 5 is calculated from
fuzzy inference based on the aforementioned deviation ϑ
m - ϑ
n and the direction-correcting speed

. It should be noted that this fuzzy inference itself is disclosed in the aforementioned
Japanese Patent Application No. 179641/1990, and since it is not directly related
to the main gist of the present invention, a description thereof will be omitted (Step
308). Then, an amount of manipulation Y
m of the direction changeover valve 8 for driving the direction-correcting cylinder
5 is calculated, and by imparting this amount of manipulation Y
m to the changeover valve 8, the excavator 1 is advanced along the planned line without
deviations (Step 309).
[0060] The operation then returns to Step 117 in Fig. 4a, and a determination is made as
to the completion of one stroke in the same way as described above.
[0061] Next, a description will be given of the case of the soil condition (3) in which
the water injection control is executed.
[0062] If it is determined in Step 115 that a rotation stall has not occurred, a determination
is made as to whether or not the detected torque T is equal to or greater than the
predetermined upper limit and the detected thrust F is equal to or less than the predetermined
upper limit. Here, it should be noted that since the upper limit of the detected torque
T is a threshold value for determining whether or not water injection is to be carried
out, the upper limit of the detected torque T is set to a value equal to or lower
than the upper limit in Step 118 (Step 123).
[0063] If YES is the answer in the determination in Step 123, this is the case where there
is no problem in advancing itself and a load is being applied to the screw 10 due
to the viscous soil, so that water injection control is executed to overcome this
situation. As a result, the viscosity is eliminated, and the removal of soil is made
smooth, thereby preventing an excessively large load from being applied onto the screw
10 (Step 124). Then, the operation proceeds to Step 118 to execute the above-described
advancing speed control and direction correction control. Meanwhile, if NO is the
answer in the determination in Step 123, an excessively large load is not being applied
onto the screw 10, and it is unnecessary to inject water, so that the operation proceeds
to Step 118 to execute the advancing speed control and the direction correction control.
[0064] Next, a description will be given of the case of the soil condition (1) in which
the pinch valve control is executed.
[0065] If it is determined in Step 115 that a rotation stall has not occurred, a determination
is made as to whether or not the fluctuation of the detected torque T is within a
predetermined range (Step 125), and a determination is made as to whether or not the
value of

representing the direction-correcting speed described above is equal to or less
than a predetermined value. It should be noted that, in order to determine the direction-correcting
speed, a parameter other than that, such as the advancing speed, may also be incorporated
(Step 126). If YES is the answer in either of the determinations in Step 125 and 126
above, it is determined that the excavator 1 is tending to slightly rise upward, and
that the advance along the planned line is becoming difficult. Hence, to overcome
this situation, the pinch-valve reference pressure is reset to a value greater than
the pinch-valve reference pressure p set in Step 111, and the pinch valve 13 is controlled
in such a manner as to be maintained at this reset value (Step 130). Then, the operation
proceeds to Step 118 in which the above-described advancing speed control and direction
correction control are executed.
[0066] Meanwhile, if NO is the answer in both determinations in Steps 125 and 126 above
(YES in the determinations in Steps 127 and 128), it is determined that the excavator
1 is advancing smoothly along the planned line and there is leeway. Hence, the pinch-valve
reference pressure is reset to a value smaller than the pinch-valve reference pressure
p set in Step 111, and the pinch valve 13 is controlled in such a manner as to be
maintained at this reset value (Step 129). Then, the operation proceeds to Step 118
in which the above-described advancing speed control and direction correction control
are executed.
[0067] Described above are the details of the complex control of the excavator 1. It should
be noted that although, in this embodiment, the advancing speed control, direction
correction control, pinch-valve control, and water injection control are executed
in a complex manner, these items of control may be implemented independently. For
instance, only any one of the advancing speed control, direction correction control,
pinch-valve control, and water injection control may be executed by omitting other
items of control, or arbitrary ones of these items of control may be combined and
implemented, as required. At any rate, in accordance with each item of control of
the embodiment, the actuators are not controlled primarily on the basis of an initially
set soil condition, but the situation at the working face which changes every moment
is ascertained by the sensors, and the actuators are controlled while correcting the
soil condition. Therefore, the excavation by the excavator 1 is performed with a high
degree of precision, and the operating efficiency improves substantially.
[0068] There are various stages in the operation by the above-described excavator 1, and
can be classified into the following stages in terms of the execution procedure:
(a) An operation-starting stage in which the excavator 1 and peripheral devices are
interconnected (hereafter referred to as the "stage of starting the operation"),
(b) A stage in which the excavator 1 and the peripheral devices are installed in the
starting shaft HL, and advancing is about to be started (hereafter referred to as
the "stage of starting advancing"),
(c) A stage in which advancing by the excavator 1 is actually started and excavation
is being carried out (hereafter referred to as the "stage of executing advancing"),
and
(d) A stage in which advancing by the excavator 1 is completed by one stroke (hereafter
referred to as the "stage of completion of one stroke").
[0069] The technology itself is known which, for the purpose of improving the reliability
of a system, carries out self-diagnosis and issues a malfunctional warning by monitoring
the system on the basis of outputs from various sensors, thereby improving the reliability
of the system. However, with the system of the excavator, the details to be diagnosed
and the details for which a warning is to be issued differ for each stage of operation,
respectively. Accordingly, an embodiment which is described below is designed to effect
only the necessary diagnosis and warning in correspondence with each stage of operation
so as to attain speedy processing.
[0070] That is, as shown in Figs. 9a and 9b, at the stage of starting the operation, the
respective devices are interconnected by signal lines, and a power supply is then
turned on. The transmission of signals between the devices may be effected by means
of radio transmission, as required (Step 401). As the power supply is turned on, the
operation proceeds to a "start-up inspection routine." Incidentally, the operation
may proceed to the "start-up inspection routine" as the operator enters data representing
the "stage of starting the operation" by performing a keying operation on the keyboard
of the input device 35. In this "start-up inspection routine," self-diagnosis and
malfunctional warning which are adapted for the stage of starting the operation are
conducted. As for the details of self-diagnosis, whether the elements of the system
are properly connected and the elements operate properly are mainly checked. For instance,
a check is made as to whether or not signals from the sensors are being properly inputted
to and outputted from the operation panel controller 34 by means of the input/output
board (Step 402). As a result, if it is determined that there is an abnormality (YES
in the determination in Step 403), the details of the error are displayed on the screen
of the display 36 to give a warning to the operator (Step 404), and the operation
of the system is stopped.
[0071] Subsequently, required inspection is performed, the system is restarted, and the
power supply is turned on again in Step 401.
[0072] If there is no abnormality at the stage of starting the operation (NO in the determination
in Step 403), preparation for an advancing start is made. If the operator enters data
representing the "stage of starting advancing" by performing a keying operation on
the keyboard of the input device 35 (YES in the determination in Step 405), the operation
proceeds to a "swinging-motion confirming routine." In this "swinging-motion confirming
routine," self-diagnosis and malfunctional warning which are adapted for the stage
of starting advancing are conducted. As for the details of self-diagnosis, the operation
of the actuators necessary for advancing is mainly checked. For example, a control
signal for driving the direction-correcting cylinder 5 is outputted, as required,
and a determination is made as to whether or not the swinging motion of the cutter
head 4 is being performed properly on the basis of a detection signal from the proximity
sensor 6 (Step 406). As a result, if it is determined that there is an abnormality
(YES in the determination in Step 407), the operation returns to the aforementioned
Step 404, and an error is displayed on the screen of the display 36.
[0073] Meanwhile, if NO is the answer in the determination in Step 405 or NO is the answer
in the determination in Step 407, it is determined that the check of swinging motion
is completed. Then, detected values from the various sensors such as the laser target
3 and failure signals from the oil/air pressure sensors 32 are inputted (Step 408),
and a determination is made as to whether or not a failure has occurred (Step 409).
If it is determined that a failure has occurred, a determination is made as to whether
or not it is serious under a predetermined standard (Step 410). If it is serious,
the operation returns to Step 404, and an error to that effect is displayed. On the
other hand, if the failure is not serious, a failure flag is set (Step 411), and measured
values of the various sensors are displayed (Step 412).
[0074] Meanwhile, if it is determined in Step 409 that a failure has not occurred, the failure
flag is reset (Step 413), and the operation proceeds to Step 412 to display measured
values of the various sensors.
[0075] Next, a menu key is checked (Step 414), and a determination is made as to whether
or not a warning reference is to be made (Step 415). As a result, if a warning reference
is to be made, advice on a countermeasure is displayed (Step 416), and after the end
of displaying (YES in the determination in Step 417), the operation returns to Step
408.
[0076] In a case where a warning reference is not to be made, if the operator performs a
keying operation on the keyboard of the input device 35 and enters data representing
the "stage of executing advancing" (YES in the determination in Step 418), the actuators
are driven and controlled to start advancing (Step 419). Then, self-diagnosis and
malfunctional warning which are adapted for the stage of executing advancing are conducted.
The details of self-diagnosis are the check of trouble in execution, in addition to
the check of the aforementioned failure. That is, measured values of the various sensors
are read out (Step 420), and if a failure has occurred (YES in the determination in
Step 421) and if it is serious (YES in the determination in Step 422), the operation
returns to Step 404 to display an error. Meanwhile, if the failure is not serious
(NO in the determination in Step 422), a failure flag is set (Step 423), measured
values are displayed, control signals are outputted to the actuators, and advancing
is resumed (Step 424).
[0077] In addition, a determination is made as to trouble in execution on the basis of the
measured values of the sensors. For example, a decision is made as to whether the
detected attitude angle has become abnormally large, and whether the detected thrust
has become abnormally large, in which case a determination is made that trouble in
execution has occurred (YES in the determination in Step 425). If it is determined
that the trouble in execution is serious under a predetermined standard (YES in the
determination in Step 426), advancing is stopped for the sake of safety, and required
inspection is carried out (Step 427). Meanwhile, if the trouble in execution is not
serious, a trouble flag is set (Step 428), and the operation proceeds to Step 424
to resume excavation.
[0078] If it is determined that trouble in execution has not occurred (NO in the determination
in Step 425), the trouble flag is reset (Step 429), and the operation proceeds to
Step 424 to resume advancing.
[0079] Next, if the completion of one stroke is detected by the sensor (YES in the determination
in Step 430), a malfunctional warning which is adapted for the stage of completion
of one stroke is issued.
[0080] Namely, a determination is made as to whether or not the failure flag and/or the
trouble flag is set (Step 431), and if either of the flags is set, there is a possibility
of occurrence of a serious failure or serious trouble in execution during an ensuing
stroke. Hence, a warning to that effect is displayed (Step 432), and the operation
returns to Step 408. Meanwhile, if neither of the two flags is set (NO in the determination
in Step 431), there is particularly no problem, so that the operation returns to Step
408 without displaying the aforementioned warning. It should be noted that the warning
lamp 39 is made to flash for the purpose of safety during the execution of advancing.
[0081] Next, referring to Fig. 10, a description will be given of processing for recording
execution data in the IC card.
[0082] Namely, if the stage of executing advancing is indicated by a keying operation, processing
is started, and detection signals from various sensors are inputted (Step 501), and
measured values are displayed (Step 502). Then, the key input is read out (Step 503),
and a determination is made as to whether or not advancing has been actually started
(Step 504). If advancing has not been started, a determination is made as to whether
or not data reference is to be made (Step 505). As a result, if data reference is
not to be made, the operation returns to Step 501 to input detection signals.
[0083] If it is determined that data reference is to be made (YES in the determination in
Step 505), the execution data is prepared, and the history of execution is displayed
(Step 506). Then, key input is read out (Step 507), and a determination is made as
to whether or not displaying has ended (Step 508). If the displaying has not ended,
the operation returns to Step 506 to repeatedly execute the displaying of the execution
data and the history. If the displaying has ended, the operation proceeds to Step
501 to conduct the inputting of detection signals again.
[0084] If it is determined in Step 504 that advancing has been started by key input, control
signals are outputted to the actuators to start advancing (Step 509). Thereafter,
detection signals from the sensors are inputted during excavation (Step 510), and
control signals are outputted to the actuators (Step 511). Then, execution data is
prepared in the meantime on the basis of the detection signals from the sensors. Unless
the stage of completion of one stroke is detected by the sensor for detecting the
completion of one stroke (NO in the determination in Step 512), processing of Steps
510 and 511 is repeatedly executed. However, if the completion of one stroke is detected
(YES in the determination in Step 512), the control signals for the actuators are
turned off to stop advancing (Step 513).
[0085] In due course of time, the execution data prepared in the IC card 37 by means of
the IC card reader/writer 38 is transferred (Step 514), and new execution data is
recorded by being added to the execution data recorded up until now (Step 515). Here,
advancing is stopped, and the execution data is transferred at a stage in which a
re-setup is being executed. Accordingly, the actual excavation work is not affected
by the transfer (the time required for it). In other words, the operating efficiency
is not impaired. Moreover, since the execution data in units of one stroke is consecutively
recorded, data management suitable for the excavator of a single-process type can
be effected.
[0086] Then, a determination is made as to whether or not the execution has ended. If the
"end of execution" is instructed by, for instance, a keying operation, processing
ends. Unless the "end of execution" is instructed, the operation returns to Step 501
to repeatedly execute similar processing.
[0087] Thus, when the execution data is consecutively recorded in the IC card 37, the operator
removes the IC card 37 from the IC card reader/writer 38, carries it, and sets it
in the IC card reader/writer 41 in the building. Then, the operator is able to conduct
analysis and the like of the record of execution in units of, for instance, one week,
by means of the computer system shown in Fig. 3. It should be noted that a recording
medium for recording the execution data is not confined to the IC card, and an arbitrary
recording medium may be used insofar as it is portable and the contents of the record
are not lost even when the power supply is turned off.
[0088] In addition, although, in the embodiments, it is assumed that a small-bore-pipe excavator
is used as the excavator, the present invention is not limited to the same, and may
be applied to an arbitrary underground excavator such as a tunnel-boring machine and
the like.
INDUSTRIAL APPLICABILITY
[0089] As described above, in accordance with the present invention, since the actuators
are controlled by ascertaining changes in the soil condition, excavation can be carried
out with a high degree of precision, and the operating efficiency improves remarkably.
In addition, since a self-diagnostic check and a malfunctional warning corresponding
to each stage of the operation of the excavator are conducted, such a check and the
like are conducted speedily and appropriately, so that the reliability apparatus improves
remarkably. Furthermore, since execution data can be automatically recorded for each
stroke, the recording of the execution data can be effected without impairing the
operating efficiency in the so-called excavator of a single-process type, data management
suited to the excavator of a single-process type can be carried out, and the operating
efficiency improves remarkably.