U.S. patent application number 16/941924 was filed with the patent office on 2020-11-12 for shovel and shovel management system.
The applicant listed for this patent is SUMITOMO CONSTRUCTION MACHINERY CO., LTD.. Invention is credited to Takashi NISHI.
Application Number | 20200354921 16/941924 |
Document ID | / |
Family ID | 1000005015827 |
Filed Date | 2020-11-12 |
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United States Patent
Application |
20200354921 |
Kind Code |
A1 |
NISHI; Takashi |
November 12, 2020 |
SHOVEL AND SHOVEL MANAGEMENT SYSTEM
Abstract
A shovel includes a lower traveling body, an upper turning body
turnably mounted on the lower traveling body, an attachment
attached to the upper turning body, and a hardware processor on the
upper turning body and configured to execute automatic control. The
hardware processor is configured to stop the automatic control when
information on the movement of the shovel or information on the
state of a nearby machine shows an unusual tendency.
Inventors: |
NISHI; Takashi; (Chiba,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SUMITOMO CONSTRUCTION MACHINERY CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
1000005015827 |
Appl. No.: |
16/941924 |
Filed: |
July 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2019/003201 |
Jan 30, 2019 |
|
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16941924 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E02F 3/32 20130101; E02F
3/439 20130101; E02F 9/2285 20130101; E02F 9/123 20130101; E02F
9/2004 20130101 |
International
Class: |
E02F 3/43 20060101
E02F003/43; E02F 3/32 20060101 E02F003/32; E02F 9/12 20060101
E02F009/12; E02F 9/22 20060101 E02F009/22; E02F 9/20 20060101
E02F009/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2018 |
JP |
2018-013970 |
Claims
1. A shovel comprising: a lower traveling body; an upper turning
body turnably mounted on the lower traveling body; an attachment
attached to the upper turning body; and a hardware processor on the
upper turning body and configured to execute automatic control,
wherein the hardware processor is configured to stop the automatic
control when information on a movement of the shovel or information
on a state of a nearby machine shows an unusual tendency.
2. The shovel as claimed in claim 1, wherein the information on the
movement of the shovel is information on an operation of an
operating apparatus mounted on the upper turning body, and the
hardware processor is further configured to determine that the
information on the movement of the shovel shows the unusual
tendency when the operating apparatus is rapidly operated.
3. The shovel as claimed in claim 1, wherein the automatic control
is automatic straight facing control or automatic complex turning
control, the information on the movement of the shovel is
information on an operation of an operating apparatus mounted on
the upper turning body, and the hardware processor is configured to
determine that the information on the movement of the shovel shows
the unusual tendency when an operation to turn the upper turning
body in a direction opposite to a direction of turning performed by
the automatic control.
4. The shovel as claimed in claim 1, further comprising: a switch
related to the automatic control, wherein the hardware processor is
further configured to execute the automatic control when the switch
is operated.
5. The shovel as claimed in claim 1, wherein the automatic control
is control to move a working part along an intended trajectory.
6. The shovel as claimed in claim 5, wherein the intended
trajectory is generated based on an output of a space recognition
device.
7. The shovel as claimed in claim 1, wherein a first operation
signal output by an operating signal generating part of an
operating lever is input to the hardware processor, and a second
operation signal is output to a solenoid valve controlling a pilot
pressure of a control valve, based on the input first operation
signal.
8. The shovel as claimed in claim 1, wherein the hardware processor
is configured to stop the automatic control when an operator
performs an arm opening operation out of reflex or when the
operator performs a boom lowering operation out of reflex.
9. A shovel comprising: a lower traveling body; an upper turning
body turnably mounted on the lower traveling body; an attachment
attached to the upper turning body; a space recognition device
attached to the upper turning body; a body tilt sensor configured
to detect a tilt of the upper turning body; and a hardware
processor on the upper turning body and configured to execute
automatic control, wherein the hardware processor is configured to
stop the automatic control based on an output of the body tilt
sensor or the space recognition device.
10. The shovel as claimed in claim 9, wherein the automatic control
is control to move a working part along an intended trajectory.
11. The shovel as claimed in claim 10, wherein the intended
trajectory is generated based on the output of the space
recognition device.
12. The shovel as claimed in claim 10, wherein the intended
trajectory is a trajectory related to a movement of an excavation
attachment in work of loading a bed of a dump truck with soil.
13. The shovel as claimed in claim 9, wherein a first operation
signal output by an operating signal generating part of an
operating lever is input to the hardware processor, and a second
operation signal is output to a solenoid valve controlling a pilot
pressure of a control valve, based on the input first operation
signal.
14. The shovel as claimed in claim 9, wherein the hardware
processor is configured to stop the automatic control when an
operator performs an arm opening operation out of reflex or when
the operator performs a boom lowering operation out of reflex.
15. The shovel as claimed in claim 9, wherein the hardware
processor is configured to perform feedback control based on a
turning angle.
16. A shovel management system comprising: a shovel configured to
store at least one of a time of a stoppage of automatic control
executed by the shovel, a location of the stoppage, an attitude of
the shovel at the time of the stoppage, and a peripheral image at
the time of the stoppage, and transmit the stored at least one of
the time, the location, the attitude, and the peripheral image; and
a management apparatus configured to receive the at least one of
the time, the location, the attitude, and the peripheral image, and
output at least one of the received attitude and peripheral image
when the management apparatus receives the at least one of the
attitude and the peripheral image.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application filed under
35 U.S.C. 111(a) claiming benefit under 35 U.S.C. 120 and 365(c) of
PCT International Application No. PCT/JP2019/003201, filed on Jan.
30, 2019 and designating the U.S., which claims priority to
Japanese patent application No. 2018-013970, filed on Jan. 30,
2018. The entire contents of the foregoing applications are
incorporated herein by reference.
BACKGROUND
Technical Field
[0002] The present disclosure relates to shovels and shovel
management systems.
Description of Related Art
[0003] An excavator that enables selective use of a manual control
mode and an automatic control mode has been known, where the manual
control mode causes only an arm to operate in response to the
operation of an aim operating lever and the automatic control mode
causes not only the arm but also a boom and a bucket to operate in
response to the operation of the arm operating lever. This
excavator can automatically move the attachment such that the
bucket moves along an inclined surface having a preset inclination
angle in the automatic control mode. Specifically, this excavator
can move the leading edge of the bucket in a straight line by
automatically operating the boom and the bucket in response to the
operation of the arm operating lever.
SUMMARY
[0004] According to an aspect of the present invention, a shovel
includes a lower traveling body, an upper turning body turnably
mounted on the lower traveling body, an attachment attached to the
upper turning body, and a hardware processor on the upper turning
body and configured to execute automatic control. The hardware
processor is configured to stop the automatic control when
information on the movement of the shovel or information on the
state of a nearby machine shows an unusual tendency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a side view of a shovel according to an embodiment
of the present invention;
[0006] FIG. 2 is a diagram illustrating an example configuration of
the basic system of the shovel of FIG. 1;
[0007] FIG. 3 is a diagram illustrating an example configuration of
a hydraulic system installed in the shovel of FIG. 1;
[0008] FIG. 4 is a block diagram illustrating an example of the
relationship between functional elements associated with the
execution of automatic control in a controller;
[0009] FIG. 5 is a block diagram illustrating an example
configuration of the functional element that calculates various
command values;
[0010] FIG. 6 is a diagram illustrating the state of the hydraulic
system when an arm opening operation has been performed during
automatic excavation control in the shovel where an emergency stop
function is disabled;
[0011] FIG. 7 is a diagram illustrating the movement of an
excavation attachment when an arm opening operation has been
performed during the automatic excavation control in the shovel
where the emergency stop function is disabled;
[0012] FIG. 8 is a diagram illustrating the state of the hydraulic
system when an aim opening operation has been performed during the
automatic excavation control in the shovel where the emergency stop
function is enabled;
[0013] FIG. 9 is a diagram illustrating the movement of the
excavation attachment when an aim opening operation has been
performed during the automatic excavation control in the shovel
where the emergency stop function is enabled;
[0014] FIG. 10 is a diagram illustrating the state of the hydraulic
system when a bool lowering operation has been performed during the
automatic excavation control in the shovel where the emergency stop
function is enabled;
[0015] FIG. 11 is a diagram illustrating the movement of the
excavation attachment when a boom lowering operation has been
performed during the automatic excavation control in the shovel
where the emergency stop function is enabled;
[0016] FIG. 12 is a block diagram illustrating another example of
the relationship between the functional elements associated with
the execution of automatic control in the controller;
[0017] FIG. 13 is a block diagram illustrating another example
configuration of the functional element that calculates various
command values;
[0018] FIG. 14 is a plan view of a work site, illustrating the
movement of the excavation attachment when a turning operation is
performed during automatic complex turning control;
[0019] FIG. 15 is a diagram illustrating the movement of the
excavation attachment when a counterclockwise turning operation is
performed during the clockwise turning of an upper turning body in
the shovel where the emergency stop function is enabled;
[0020] FIG. 16 is a diagram illustrating an example configuration
of an electric operation system; and
[0021] FIG. 17 is a schematic diagram illustrating an example
configuration of a shovel management system.
DETAILED DESCRIPTION
[0022] Normally, the excavator is used in various operating
environments. Therefore, the operating environment around the
excavator may change to an operating environment different from the
expected operating environment even when the automatic control mode
is in operation. In this case, the above-described excavator
continues operation in the automatic control mode even when the
operating environment changes. For example, when the operator
operates the arm operating lever with the intention to open the arm
to press the bucket against an upward inclined surface in an
emergency during the automatic control mode, the excavator may
automatically raise the boom in accordance with the opening of the
arm to move the bucket along the upward inclined surface. In this
case, the operator may be unable to press the bucket against the
upward inclined surface as intended.
[0023] Therefore, even during automatic control, it is desirable to
cause a shovel to perform operation different from the operation of
the automatic control when the operating environment of the shovel
changes to an operating environment different from the expected
operating environment.
[0024] According to an aspect of the present invention, it is
possible to cause a shovel to perform operation different from the
operation of automatic control when the operating environment of
the shovel changes to an operating environment different from the
expected operating environment even during the automatic
control.
[0025] FIG. 1 is a side view of a shovel 100 serving as an
excavator according to an embodiment of the present invention. An
upper turning body 3 is turnably mounted on a lower traveling body
1 of the shovel 100 via a turning mechanism 2. A boom 4 is attached
to the upper turning body 3. An arm 5 is attached to the distal end
of the boom 4, and a bucket 6 serving as an end attachment is
attached to the distal end of the arm 5.
[0026] The boom 4, the arm 5, and the bucket 6 form an excavation
attachment that is an example of an attachment. The boom 4 is
driven by a boom cylinder 7, the arm 5 is driven by an arm cylinder
8, and the bucket 6 is driven by a bucket cylinder 9.
[0027] Specifically, the boom cylinder 7 is driven in response to
tilting of a boom operating lever, the arm cylinder 8 is driven in
response to tilting of an arm operating lever, and the bucket
cylinder 9 is driven in response to tilting of a bucket operating
lever. Likewise, a right side traveling hydraulic motor 1R (see
FIG. 2) is driven in response to tilting of a right side travel
lever, a left side traveling hydraulic motor 1L (see FIG. 2) is
driven in response to tilting of a left travel lever, and a turning
hydraulic motor 2A (see FIG. 2) is driven in response to tilting of
a turning operating lever. Thus, a corresponding actuator is driven
in response to the operation of each lever, so that control of the
shovel 100 through an operator's manual operation (hereinafter
"manual control") is performed.
[0028] Furthermore, a boom angle sensor S1 is attached to the boom
4, an arm angle sensor S2 is attached to the arm 5, and a bucket
angle sensor S3 is attached to the bucket 6.
[0029] The boom angle sensor S1 is configured to detect the
rotation angle of the boom 4. According to this embodiment, the
boom angle sensor S1 is an acceleration sensor and can detect the
rotation angle of the boom 4 relative to the upper turning body 3
(hereinafter, "boom angle"). For example, the boom angle is
smallest when the boom 4 is lowest and increases as the boom 4 is
raised.
[0030] The arm angle sensor S2 is configured to detect the rotation
angle of the arm 5. According to this embodiment, the arm angle
sensor S2 is an acceleration sensor and can detect the rotation
angle of the arm 5 relative to the boom 4 (hereinafter, "arm
angle"). For example, the arm angle is smallest when the arm 5 is
most closed and increases as the arm 5 is opened.
[0031] The bucket angle sensor S3 is configured to detect the
rotation angle of the bucket 6. According to this embodiment, the
bucket angle sensor S3 is an acceleration sensor and can detect the
rotation angle of the bucket 6 relative to the arm 5 (hereinafter,
"bucket angle"). For example, the bucket angle is smallest when the
bucket 6 is most closed and increases as the bucket 6 is
opened.
[0032] Each of the boom angle sensor S1, the arm angle sensor S2,
and the bucket angle sensor S3 may alternatively be a potentiometer
using a variable resistor, a stroke sensor that detects the stroke
amount of a corresponding hydraulic cylinder, a rotary encoder that
detects a rotation angle about a link pin, an inertial measurement
unit, a gyroscope, a combination of an acceleration sensor and a
gyroscope, or the like.
[0033] A cabin 10 that is a cab is provided and a power source such
as an engine 11 is mounted on the upper turning body 3. A
controller 30, a display device 40, an input device 42, an audio
output device 43, a storage device 47, an emergency stop switch 48,
a body tilt sensor S4, a turning angular velocity sensor S5, an
image capturing device S6, a communications device T1, and a
positioning device P1 are attached to the upper turning body 3.
[0034] The controller 30 is configured to operate as a control
device to control the driving of the shovel 100. According to this
embodiment, the controller 30 is constituted of a computer
including a CPU, a RAM, a ROM, etc. Various functions provided by
the controller 30 are implemented by the CPU executing programs
stored in the ROM, for example. The various functions include, for
example, a machine guidance function to guide (give directions to)
an operator in manually operating the shovel 100 and a machine
control function to automatically assist the operator in manually
operating the shovel 100. A machine guidance device 50 included in
the controller 30 is configured to be able to execute the machine
guidance function and the machine control function.
[0035] The display device 40 is configured to display various kinds
of information. The display device 40 may be connected to the
controller 30 via a communications network such as a CAN or may be
connected to the controller 30 via a dedicated line.
[0036] The input device 42 is so configured as to enable the
operator to input various kinds of information to the controller
30. The input device 42 includes, for example, at least one of a
touchscreen, a knob switch, a membrane switch, etc., provided in
the cabin 10.
[0037] The audio output device 43 is configured to output audio
information. The audio output device 43 may be, for example, an
in-vehicle loudspeaker connected to the controller 30 or an alarm
such as a buzzer. According to this embodiment, the audio output
device 43 outputs various kinds of audio information in response to
a command from the controller 30.
[0038] The storage device 47 is configured to store various kinds
of information. Examples of the storage device 47 include a
nonvolatile storage medium such as a semiconductor memory. The
storage device 47 may store the output information of various
devices while the shovel 100 is in operation and may store
information obtained through various devices before the shovel 100
starts to operate. The storage device 47 may store, for example,
data on an intended work surface obtained through the
communications device T1, etc. The intended work surface may be set
by the operator of the shovel 100 or may be set by a work manager
or the like. The emergency stop switch 48 is configured to operate
as a switch for stopping the movement of the shovel 100. The
emergency stop switch 48 is, for example, a switch installed at
such a position as to be operable by the operator seated in an
operator seat in the cabin 10. According to this embodiment, the
emergency stop switch 48 is a foot switch installed at the
operator's feet in the cabin 10. When operated by the operator, the
emergency stop switch 48 outputs a command to an engine control
unit to stop the engine 11. The emergency stop switch 48 may also
be a hand switch installed around the operator seat.
[0039] The body tilt sensor S4 is configured to detect the
inclination of the upper turning body 3. According to this
embodiment, the body tilt sensor S4 is an acceleration sensor that
detects the inclination of the upper turning body 3 relative to a
virtual horizontal plane. The body tilt sensor S4 may be a
combination of an acceleration sensor and a gyroscope or may be an
inertial measurement unit or the like. The body tilt sensor S4
detects, for example, the upper turning body 3's tilt angle about
its longitudinal axis (roll angle) and tilt angle about its lateral
axis (pitch angle). For example, the longitudinal axis and the
lateral axis of the upper turning body 3 cross each other at right
angles at the shovel center point that is a point on the turning
axis of the shovel 100.
[0040] The image capturing device S6 is configured to capture an
image of an area surrounding the shovel 100. According to this
embodiment, the image capturing device S6 includes a front camera
S6F that captures an image of a space in front of the shovel 100, a
left camera S6L that captures an image of a space to the left of
the shovel 100, a right camera S6R that captures an image of a
space to the right of the shovel 100, and a back camera S6B that
captures an image of a space behind the shovel 100.
[0041] The image capturing device S6 is, for example, a monocular
camera including an imaging device such as a CCD or a CMOS, and
outputs captured images to the display device 40. The image
capturing device S6 may also be configured to operate as a space
recognition device S7. The space recognition device S7 is
configured to be able to detect an object present in a
three-dimensional space around the shovel 100. The object is, for
example, at least one of a person, an animal, a shovel, a machine,
a building, etc. The space recognition device S7 may also be
configured to be able to calculate the distance between the space
recognition device S7 or the shovel 100 and an object detected by
the space recognition device S7. The space recognition device S7
may be an ultrasonic sensor, a millimeter wave radar, a monocular
camera, a stereo camera, a LIDAR, a distance image sensor, an
infrared sensor, or the like.
[0042] The front camera S6F is attached to, for example, the
ceiling of the cabin 10, namely, the inside of the cabin 10. The
front camera S6F may alternatively be attached to the roof of the
cabin 10, namely, the outside of the cabin 10. The left camera S6L
is attached to the left end of the upper surface of the upper
turning body 3. The right camera S6R is attached to the right end
of the upper surface of the upper turning body 3. The back camera
S6B is attached to the back end of the upper surface of the upper
turning body 3. The communications device T1 is configured to
control communications with external apparatuses outside the shovel
100. According to this embodiment, the communications device T1
controls communications with external apparatuses via at least one
of a satellite communications network, a cellular phone network, a
short-range radio communications network, the Internet, etc.
[0043] The positioning device P1 is configured to be able to
measure the position of the upper turning body 3. The positioning
device P1 may also be configured to measure the orientation of the
upper turning body 3. The positioning device P1 is, for example, a
GNSS compass, and detects the position and orientation of the upper
turning body 3 to output detection values to the controller 30.
Therefore, the positioning device P1 can also operate as an
orientation detector to detect the orientation of the upper turning
body 3. The orientation detector may be an azimuth sensor attached
to the upper turning body 3. Furthermore, the position and
orientation of the upper turning body 3 may be measured with the
turning angular velocity sensor S5.
[0044] The turning angular velocity sensor S5 is configured to
detect the turning angular velocity of the upper turning body 3.
The turning angular velocity sensor S5 may also be configured to be
able to detect or calculate the turning angle of the upper turning
body 3. According to this embodiment, the turning angular velocity
sensor S5 is a gyroscope. The turning angular velocity sensor S5
may also be a resolver, a rotary encoder, an inertial measurement
unit, or the like.
[0045] FIG. 2 is a block diagram illustrating an example
configuration of the basic system of the shovel 100, in which a
mechanical power transmission line, a hydraulic oil line, a pilot
line, and an electric control line are indicated by a double line,
a solid line, a dashed line, and a dotted line, respectively.
[0046] The basic system of the shovel 100 mainly includes the
engine 11, a regulator 13, a main pump 14, a pilot pump 15, a
control valve 17, an operating apparatus 26, a discharge pressure
sensor 28, an operating pressure sensor 29, the controller 30, a
proportional valve 31, and a shuttle valve 32.
[0047] The engine 11 is a drive source of the shovel 100. According
to this embodiment, the engine 11 is a diesel engine that so
operates as to maintain a predetermined rotational speed. The
output shaft of the engine 11 is coupled to the respective input
shafts of the main pump 14 and the pilot pump 15.
[0048] The main pump 14 is configured to supply hydraulic oil to
the control valve 17 via a hydraulic oil line. According to this
embodiment, the main pump 14 is a swash plate variable displacement
hydraulic pump.
[0049] The regulator 13 is configured to control the discharge
quantity of the main pump 14. According to this embodiment, the
regulator 13 controls the discharge quantity of the main pump 14 by
adjusting the swash plate tilt angle of the main pump 14 in
response to a command from the controller 30. For example, the
controller 30 receives the outputs of the discharge pressure sensor
28, the operating pressure sensor 29, etc., and outputs a command
to the regulator 13 to vary the discharge quantity of the main pump
14 on an as-needed basis.
[0050] The pilot pump 15 is configured to supply hydraulic oil to
various hydraulic control apparatuses including the operating
apparatus 26 and the proportional valve 31 via a pilot line.
According to this embodiment, the pilot pump 15 is a fixed
displacement hydraulic pump. The pilot pump 15, however, may be
omitted. In this case, the function carried by the pilot pump 15
may be implemented by the main pump 14. That is, the main pump 14
may have the function of supplying hydraulic oil to the operating
apparatus 26, the proportional valve 31, etc., after reducing the
pressure of the hydraulic oil with a throttle or the like, apart
from the function of supplying hydraulic oil to the control valve
17.
[0051] The control valve 17 is a hydraulic control device that
controls a hydraulic system in the shovel 100.
[0052] According to this embodiment, the control valve 17 includes
control valves 171 through 176. The control valve 17 can
selectively supply hydraulic oil discharged by the main pump 14 to
one or more hydraulic actuators through the control valves 171
through 176. The control valves 171 through 176 control the flow
rate of hydraulic oil flowing from the main pump 14 to hydraulic
actuators and the flow rate of hydraulic oil flowing from hydraulic
actuators to a hydraulic oil tank. The hydraulic actuators include
the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the
left side traveling hydraulic motor 1L, the right side traveling
hydraulic motor 1R, and the turning hydraulic motor 2A. The turning
hydraulic motor 2A may alternatively be a turning electric motor
serving as an electric actuator.
[0053] The operating apparatus 26 is an apparatus that the operator
uses to operate actuators. The actuators include at least one of a
hydraulic actuator and an electric actuator. According to this
embodiment, the operating apparatus 26 supplies hydraulic oil
discharged by the pilot pump 15 to a pilot port of a corresponding
control valve in the control valve 17 via a pilot line. The
pressure of hydraulic oil supplied to each pilot port (pilot
pressure) is, in principle, a pressure commensurate with the
direction of operation and the amount of operation of the operating
apparatus 26 for a corresponding hydraulic actuator. At least one
of the operating apparatus 26 is configured to be able to supply
hydraulic oil discharged by the pilot pump 15 to a pilot port of a
corresponding control valve in the control valve 17 via a pilot
line and the shuttle valve 32.
[0054] The discharge pressure sensor 28 is configured to detect the
discharge pressure of the main pump 14. According to this
embodiment, the discharge pressure sensor 28 outputs the detected
value to the controller 30.
[0055] The operating pressure sensor 29 is configured to detect the
details of the operator's operation using the operating apparatus
26. According to this embodiment, the operating pressure sensor 29
detects the direction of operation and the amount of operation of
the operating apparatus 26 corresponding to each actuator in the
form of pressure and outputs the detected value to the controller
30 as operational data. The operation details of the operating
apparatus 26 may be detected using a sensor other than an operating
pressure sensor.
[0056] The proportional valve 31 is placed in a conduit connecting
the pilot pump 15 and the shuttle valve 32, and is configured to be
able to change the flow area of the conduit. According to this
embodiment, the proportional valve 31 is a solenoid valve that
operates in response to a control command output by the controller
30. The proportional valve 31 operates as a control valve for
machine control. Therefore, the controller 30 can supply hydraulic
oil discharged by the pilot pump 15 to a pilot port of a
corresponding control valve in the control valve 17 via the
proportional valve 31 and the shuttle valve 32, independent of the
operator's operation of the operating apparatus 26.
[0057] The shuttle valve 32 includes two inlet ports and one outlet
port. Of the two inlet ports, one is connected to the operating
apparatus 26 and the other is connected to the proportional valve
31. The outlet port is connected to a pilot port of a corresponding
control valve in the control valve 17. Therefore, the shuttle valve
32 can cause the higher one of a pilot pressure generated by the
operating apparatus 26 and a pilot pressure generated by the
proportional valve 31 to act on a pilot port of a corresponding
control valve.
[0058] According to this configuration, the controller 30 can
operate a hydraulic actuator corresponding to a specific operating
apparatus 26 even when no operation is performed on the specific
operating apparatus 26.
[0059] Next, the machine guidance device 50 included in the
controller 30 is described. The machine guidance device 50 is
configured to execute the machine guidance function, for example.
According to this embodiment, the machine guidance device 50, for
example, notifies the operator of work information such as the
distance between the intended work surface and the working part of
the attachment. Data on the intended work surface are prestored in,
for example, the storage device 47. The data on the intended work
surface are expressed in, for example, a reference coordinate
system. The reference coordinate system is, for example, the world
geodetic system. The operator may set any point at a construction
site as a reference point and set the intended work surface based
on the relative positional relationship between each point of the
intended work surface and the reference point. The working part of
the attachment is, for example, the teeth tips of the bucket 6, the
back surface of the bucket 6, or the like. The machine guidance
device 50 provides guidance on operating the shovel 100 by
notifying the operator of the work information via at least one of
the display device 40, the audio output device 43, etc.
[0060] The machine guidance device 50 may execute the machine
control function to automatically assist the operator in manually
operating the shovel 100. For example, when the operator is
manually performing operation for excavation, the machine guidance
device 50 may automatically operate at least one of the boom 4, the
arm 5, and the bucket 6 such that the distance between the intended
work surface and the position of the leading edge of the bucket 6
is maintained at a predetermined value.
[0061] The machine guidance device 50, which is incorporated into
the controller 30 according to this embodiment, may be a control
device provided separately from the controller 30. In this case,
for example, like the controller 30, the machine guidance device 50
is constituted of a computer including a CPU, a RAM, a ROM, etc.
The CPU executes programs stored in the ROM or the like to
implement various functions provided by the machine guidance device
50. The machine guidance device 50 and the controller 30 are
connected by a communications network such as a CAN to be able to
communicate with each other.
[0062] Specifically, the machine guidance device 50 obtains
information from at least one of the boom angle sensor S1, the arm
angle sensor S2, the bucket angle sensor S3, the body tilt sensor
S4, the turning angular velocity sensor S5, the image capturing
device S6, the positioning device P1, the communications device T1,
the input device 42, etc. Then, the machine guidance device 50, for
example, calculates the distance between the bucket 6 and the
intended work surface based on the obtained information, and
notifies the operator of the shovel 100 of the size of the distance
between the bucket 6 and the intended work surface through at least
one of audio and light (image display).
[0063] To make it possible to execute the machine control function
that automatically assists in manual operation, the machine
guidance device 50 includes a position calculating part 51, a
distance calculating part 52, an information communicating part 53,
and an automatic control part 54.
[0064] The position calculating part 51 is configured to calculate
the position of a target. According to this embodiment, the
position calculating part 51 calculates the coordinate point of the
working part of the attachment in the reference coordinate system.
Specifically, the position calculating part 51 calculates the
coordinate point of the teeth tips of the bucket 6 from the
respective rotation angles of the boom 4, the arm 5, and the bucket
6. The position calculating part 51 may calculate not only the
coordinate point of the center of the teeth tips of the bucket 6
but also the coordinate point of the left end of the teeth tips of
the bucket 6 and the coordinate point of the right end of the teeth
tips of the bucket 6. In this case, the output of the body tilt
sensor S4 may be used.
[0065] The distance calculating part 52 is configured to calculate
the distance between two targets. According to this embodiment, the
distance calculating part 52 calculates the vertical distance
between the teeth tips of the bucket 6 and the intended work
surface. The distance calculating part 52 may calculate the
distance (for example, the vertical distance) between the intended
work surface and the coordinate point of each of the left end and
the right end of the teeth tips of the bucket 6 so that the machine
guidance device 50 can determine whether the shovel 100 is facing
straight to the intended work surface.
[0066] The information communicating part 53 is configured to
communicate various kinds of information to the operator of the
shovel 100. According to this embodiment, the information
communicating part 53 notifies the operator of the shovel 100 of
the size of each of the various distances calculated by the
distance calculating part 52. Specifically, the information
communicating part 53 notifies the operator of the shovel 100 of
the size of the vertical distance between the teeth tips of the
bucket 6 and the intended work surface, using visual information
and aural information.
[0067] For example, the information communicating part 53 may
notify the operator of the size of the vertical distance between
the teeth tips of the bucket 6 and the intended work surface, using
intermittent sounds through the audio output device 43. In this
case, the information communicating part 53 may reduce the interval
between intermittent sounds as the vertical distance decreases. The
information communicating part 53 may use a continuous sound and
may represent variations in the size of the vertical distance by
changing the pitch, loudness, or the like of the sound.
Furthermore, when the teeth tips of the bucket 6 are positioned
lower than the intended work surface, the information communicating
part 53 may issue an alarm. The alarm is, for example, a continuous
sound significantly louder than the intermittent sounds.
[0068] The information communicating part 53 may display the size
of the vertical distance between the teeth tips of the bucket 6 and
the intended work surface on the display device 40 as work
information. For example, the display device 40 displays the work
information received from the information communicating part 53 on
a screen, together with image data received from the image
capturing device S6. The information communicating part 53 may
notify the operator of the size of the vertical distance, using,
for example, an image of an analog meter, an image of a bar graph
indicator, or the like.
[0069] The automatic control part 54 is configured to assist the
operator in manually operating the shovel 100 by automatically
moving actuators. For example, the automatic control part 54 may
automatically extend or retract at least one of the boom cylinder
7, the arm cylinder 8, and the bucket cylinder 9 such that the
distance between the intended work surface and the teeth tips of
the bucket 6 is maintained at a predetermined value, while the
operator is manually performing an arm closing operation. In this
case, for example, by only operating the arm operating lever in a
closing direction, the operator can close the arm 5 while keeping
the distance between the intended work surface and the teeth tips
of the bucket 6. This automatic control may be executed in response
to the depression of a predetermined switch that is included in the
input device 42. That is, the automatic control part 54 may switch
the operating mode of the shovel 100 from a manual control mode to
an automatic control mode in response to the pressing of a
predetermined switch. The manual control mode means an operating
mode in which manual control is performed. The automatic control
mode means an operating mode in which automatic control is
performed. The predetermined switch is, for example, a machine
control switch (hereinafter, "MC switch 42A"), and may be placed at
the handle of an operating lever. In this case, the operator may
switch the operating mode of the shovel 100 from the automatic
control mode to the manual control mode by re-pressing the MC
switch 42A or may switch the operating mode of the shovel 100 from
the automatic control mode to the manual control mode by pressing a
machine control stop switch (hereinafter, "MC stop switch 42B")
that is a switch different from the MC switch 42A. The MC stop
switch 42B may be placed next to the MC switch 42A or may be placed
at the handle of another operating lever. Alternatively, the MC
stop switch 42B may be omitted.
[0070] Such automatic control may be performed while the MC switch
42A is being pressed. In this case, the operator can close the arm
5 while maintaining the distance between the intended work surface
and the teeth tips of the bucket 6 by only operating the arm
operating lever in the arm closing direction while pressing the MC
switch 42A at the handle of the arm operating lever, for example.
This is because the boom cylinder 7 and the bucket cylinder 9
automatically follow and move in response to the aim closing
operation caused by the arm cylinder 8. Furthermore, the operator
can stop the automatic control by only moving a finger out of
contact with the MC switch 42A. In the following, control to
automatically operate the excavation attachment while maintaining
the distance between the intended work surface and the teeth tips
of the bucket 6 is referred to "automatic excavation control" that
is one of automatic control processes (machine control
functions).
[0071] The automatic control part 54 may automatically rotate the
turning hydraulic motor 2A to cause the upper turning body 3 to
face straight to the intended work surface when a predetermined
switch such as the MC switch 42A is pressed. In this case, the
operator can cause the upper turning body 3 to face straight to the
intended work surface by only pressing the predetermined switch or
by only operating the turning operating lever while pressing the
predetermined switch. Alternatively, by only pressing the
predetermined switch, the operator can cause the upper turning body
3 to face straight to the intended work surface and start the
machine control function, namely, get the shovel 100 ready to
perform automatic control. Hereinafter, control to cause the upper
turning body 3 to face straight to the intended work surface is
referred to as "automatic straight facing control" that is one of
automatic control processes (machine control functions). According
to the automatic straight facing control, the machine guidance
device 50 determines that the shovel 100 is facing straight to the
intended work surface, for example, when the left end vertical
distance between the coordinate point of the left end of the teeth
tips of the bucket 6 and the intended work surface is equal to the
right end vertical distance between the coordinate point of the
right end of the teeth tips of the bucket 6 and the intended work
surface. The machine guidance device 50, however, may also
determine that the shovel 100 is facing straight to the intended
work surface when the difference between the left end vertical
distance and the right end vertical distance is less than or equal
to a predetermined value instead of when the left end vertical
distance and the right end vertical distance are not equal, namely,
instead of when the difference is zero.
[0072] The automatic control part 54 may also be configured to
automatically perform boom raising and turning or boom lowering and
turning in response to the pressing of a predetermined switch such
as the MC switch 42A. In this case, by only pressing the
predetermined switch or by only operating the turning operating
lever while pressing the predetermined switch, the operator can
start boom raising and turning or boom lowering and turning.
Hereinafter, control to automatically start boom raising and
turning or boom lowering and turning is referred to as "automatic
complex turning control" that is one of automatic control processes
(machine control functions).
[0073] According to this embodiment, the automatic control part 54
can individually and automatically operate actuators by
individually and automatically controlling pilot pressures acting
on control valves corresponding to the actuators. For example,
according to the automatic straight facing control, the automatic
control part 54 may operate the turning hydraulic motor 2A based on
the difference between the left end vertical distance and the right
end vertical distance. Specifically, when the turning operating
lever is operated with the predetermined switch being pressed, the
automatic control part 54 determines whether the turning operating
lever is operated in a direction to cause the upper turning body 3
to face straight to the intended work surface. For example, when
the turning operating lever is so operated as to turn the upper
turning body 3 in a direction to increase the vertical distance
between the teeth tips of the bucket 6 and the intended work
surface (upward slope), the automatic control part 54 does not
perform the automatic straight facing control. When the turning
operating lever is so operated as to turn the upper turning body 3
in a direction to decrease the vertical distance between the teeth
tips of the bucket 6 and the intended work surface (upward slope),
the automatic control part 54 performs the automatic straight
facing control. As a result, it is possible to operate the turning
hydraulic motor 2A such that the difference between the left end
vertical distance and the right end vertical distance is reduced.
Thereafter, when the difference becomes less than or equal to a
predetermined value or zero, the automatic control part 54 stops
the turning hydraulic motor 2A. The automatic control part 54 may
also set a turning angle that causes the difference to be less than
or equal to a predetermined value or zero as a target angle and
perform turning angle control such that the angular difference
between the target angle and a current turning angle (detected
value) is zero. In this case, the turning angle is, for example,
the angle of the longitudinal axis of the upper turning body 3 to a
predetermined reference direction.
[0074] The automatic control part 54 may also be configured to stop
automatic control when a predetermined condition is satisfied.
"When a predetermined condition is satisfied" may include "when
information on the movement of the shovel 100 shows an unusual
tendency." Hereinafter, a function to stop automatic control when a
predetermined condition is satisfied is referred to as "emergency
stop function."
[0075] The "information on the movement of the shovel 100" is, for
example, "information on operation on the operating apparatus 26."
For example, the automatic control part 54 may be configured to
determine that the "information on the movement of the shovel 100
shows an unusual tendency" when the operating apparatus 26 is
rapidly operated. The "information on the movement of the shovel
100" may also be "information on operation on the turning operating
lever mounted on the upper turning body 3". In this case, the
automatic control part 54 may be configured to determine that the
"information on the movement of the shovel 100 shows an unusual
tendency," for example, when an operation to turn the upper turning
body 3 in a direction opposite to that of turning performed by the
automatic straight facing control or the automatic complex turning
control as automatic control. The automatic control part 54 may
also be configured to stop automatic control in response to
determining that the "information on the movement of the shovel 100
shows an unusual tendency."
[0076] "When a predetermined condition is satisfied" may also
include "when the shovel 100 is more unstable" such as "when the
tilt of the upper turning body 3 is in a predetermined state."
"When the tilt of the upper turning body 3 is in a predetermined
state" includes, for example, "when the pitch angle of the upper
turning body 3 is a predetermined angle," "when the absolute value
of the changing speed (change rate) of the pitch angle is more than
or equal to a predetermined value," and "when the amount of change
of the pitch angle is more than or equal to a predetermined value."
The same is true for the roll angle. In this case, the automatic
control part 54 may also be configured to stop automatic control
based on the output of the body tilt sensor S4. Specifically, in
response to detecting that the pitch angle of the upper turning
body 3 is a predetermined angle based on the output of the body
tilt sensor S4, the automatic control part 54 may stop automatic
control and switch the operating mode of the shovel 100 from the
automatic control mode to the manual control mode.
[0077] Furthermore, "when a predetermined condition is satisfied"
may also include "when the emergency stop switch 48, which is a
foot switch installed at the operator's feet, is stepped on."
[0078] Next, an example configuration of a hydraulic system
installed in the shovel 100 is described with reference to FIG. 3.
FIG. 3 illustrates an example configuration of the hydraulic system
installed in the shovel 100 of FIG. 1. In FIG. 3, a mechanical
power transmission line, a hydraulic oil line, a pilot line, and an
electric control line are indicated by a double line, a solid line,
a dashed line, and a dotted line, respectively, the same as in FIG.
2.
[0079] The hydraulic system circulates hydraulic oil from a left
main pump 14L driven by the engine 11 to the hydraulic oil tank via
a left center bypass conduit 40L or a left parallel conduit 42L,
and circulates hydraulic oil from a right main pump 14R driven by
the engine 11 to the hydraulic oil tank via a right center bypass
conduit 40R or a right parallel conduit 42R. The left main pump 14L
and the right main pump 14R correspond to the main pump 14 of FIG.
2.
[0080] The left center bypass conduit 40L is a hydraulic oil line
that passes through the control valves 171 and 173 and control
valves 175L and 176L placed in the control valve 17. The right
center bypass conduit 40R is a hydraulic oil line that passes
through the control valves 172 and 174 and control valves 175R and
176R placed in the control valve 17. The control valves 175L and
175R correspond to the control valve 175 of FIG. 2. The control
valves 176L and 176R correspond to the control valve 176 of FIG.
2.
[0081] The control valve 171 is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the left main pump 14L to the left side traveling hydraulic
motor 1L and to discharge hydraulic oil discharged by the left side
traveling hydraulic motor 1L to the hydraulic oil tank.
[0082] The control valve 172 is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the right main pump 14R to the right side traveling hydraulic
motor 1R and to discharge hydraulic oil discharged by the right
side traveling hydraulic motor 1R to the hydraulic oil tank.
[0083] The control valve 173 is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the left main pump 14L to the turning hydraulic motor 2A and to
discharge hydraulic oil discharged by the turning hydraulic motor
2A to the hydraulic oil tank.
[0084] The control valve 174 is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the right main pump 14R to the bucket cylinder 9 and to
discharge hydraulic oil in the bucket cylinder 9 to the hydraulic
oil tank.
[0085] The control valve 175L is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the left main pump 14L to the boom cylinder 7.
[0086] The control valve 175R is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the right main pump 14R to the boom cylinder 7 and to discharge
hydraulic oil in the boom cylinder 7 to the hydraulic oil tank.
[0087] The control valve 176L is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the left main pump 14L to the arm cylinder 8 and to discharge
hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.
[0088] The control valve 176R is a spool valve that switches the
flow of hydraulic oil in order to supply hydraulic oil discharged
by the right main pump 14R to the arm cylinder 8 and to discharge
hydraulic oil in the arm cylinder 8 to the hydraulic oil tank.
[0089] The left parallel conduit 42L is a hydraulic oil line
parallel to the left center bypass conduit 40L. When the flow of
hydraulic oil through the left center bypass conduit 40L is
restricted or blocked by any of the control valves 171, 173 and
175L, the left parallel conduit 42L can supply hydraulic oil to a
control valve further downstream. The right parallel conduit 42R is
a hydraulic oil line parallel to the right center bypass conduit
40R. When the flow of hydraulic oil through the right center bypass
conduit 40R is restricted or blocked by any of the control valves
172, 174 and 175R, the right parallel conduit 42R can supply
hydraulic oil to a control valve further downstream.
[0090] A left regulator 13L is configured to be able to control the
discharge quantity of the left main pump 14L. According to this
embodiment, the left regulator 13L controls the discharge quantity
of the left main pump 14L, for example, by adjusting the swash
plate tilt angle of the left main pump 14L in accordance with the
discharge pressure of the left main pump 14L. A right regulator 13R
is configured to be able to control the discharge quantity of the
right main pump 14R. According to this embodiment, the right
regulator 13R controls the discharge quantity of the right main
pump 14R, for example, by adjusting the swash plate tilt angle of
the right main pump 14R in accordance with the discharge pressure
of the right main pump 14R. The left regulator 13L and the right
regulator 13R correspond to the regulator 13 of FIG. 2. The left
regulator 13L, for example, reduces the discharge quantity of the
left main pump 14L by adjusting its swash plate tilt angle,
according as the discharge pressure of the left main pump 14L
increases. The same is the case with the right regulator 13R. This
is for preventing the absorbed power of the main pump 14 expressed
by the product of the discharge pressure and the discharge quantity
from exceeding the output power of the engine 11.
[0091] A discharge pressure sensor 28L, which is an example of the
discharge pressure sensor 28, detects the discharge pressure of the
left main pump 14L, and outputs the detected value to the
controller 30. The same is the case with a discharge pressure
sensor 28R.
[0092] Here, negative control adopted in the hydraulic system of
FIG. 3 is described.
[0093] A left throttle 18L is placed between the most downstream
control valve 176L and the hydraulic oil tank in the left center
bypass conduit 40L. The flow of hydraulic oil discharged by the
left main pump 14L is restricted by the left throttle 18L. The left
throttle 18L generates a control pressure for controlling the left
regulator 13L. A left control pressure sensor 19L is a sensor for
detecting the control pressure, and outputs the detected value to
the controller 30. A right throttle 18R is placed between the most
downstream control valve 176R and the hydraulic oil tank in the
right center bypass conduit 40R. The flow of hydraulic oil
discharged by the right main pump 14R is restricted by the right
throttle 18R. The right throttle 18R generates a control pressure
for controlling the right regulator 13R. A right control pressure
sensor 19R is a sensor for detecting the control pressure, and
outputs the detected value to the controller 30.
[0094] The controller 30 controls the discharge quantity of the
left main pump 14L by adjusting the swash plate tilt angle of the
left main pump 14L in accordance with the control pressure. The
controller 30 decreases the discharge quantity of the left main
pump 14L as the control pressure increases, and increases the
discharge quantity of the left main pump 14L as the control
pressure decreases. The discharge quantity of the right main pump
14R is controlled in the same manner.
[0095] Specifically, as illustrated in FIG. 3, in a standby state
where none of the hydraulic actuators is operated in the shovel
100, hydraulic oil discharged by the left main pump 14L arrives at
the left throttle 18L through the left center bypass conduit 40L.
The flow of hydraulic oil discharged by the left main pump 14L
increases the control pressure generated upstream of the left
throttle 18L. As a result, the controller 30 decreases the
discharge quantity of the left main pump 14L to a minimum allowable
discharge quantity to reduce pressure loss (pumping loss) during
the passage of the discharged hydraulic oil through the left center
bypass conduit 40L. In contrast, when a hydraulic actuator is
operated, hydraulic oil discharged by the left main pump 14L flows
into the operated hydraulic actuator via a control valve
corresponding to the operated hydraulic actuator. The flow of
hydraulic oil discharged by the left main pump 14L that arrives at
the left throttle 18L is reduced in amount or lost, so that the
control pressure generated upstream of the left throttle 18L is
reduced. As a result, the controller 30 increases the discharge
quantity of the left main pump 14L to circulate sufficient
hydraulic oil to the operated hydraulic actuator to ensure driving
of the operated hydraulic actuator. The same is the case with
hydraulic oil discharged by the right main pump 14R.
[0096] According to the configuration as described above, the
hydraulic system of FIG. 3 can reduce unnecessary energy
consumption in each of the left main pump 14L and the right main
pump 14R in the standby state. The unnecessary energy consumption
includes pumping loss that hydraulic oil discharged by the left
main pump 14L causes in the left center bypass conduit 40L and
pumping loss that hydraulic oil discharged by the right main pump
14R causes in the right center bypass conduit 40R. Furthermore, in
the case of actuating hydraulic actuators, the hydraulic system of
FIG. 3 can supply necessary and sufficient hydraulic oil from each
of the left main pump 14L and the right main pump 14R to hydraulic
actuators to be actuated.
[0097] Next, a configuration for causing an actuator to
automatically operate is described. A boom operating lever 26A is
an example of the operating apparatus 26 and is used to operate the
boom 4. The boom operating lever 26A uses hydraulic oil discharged
by the pilot pump 15 to cause a pilot pressure commensurate with
the details of an operation to act on pilot ports of the control
valves 175L and 175R. Specifically, when operated in a boom raising
direction, the boom operating lever 26A causes a pilot pressure
commensurate with the amount of operation to act on the right pilot
port of the control valve 175L and the left pilot port of the
control valve 175R. When operated in a boom lowering direction, the
boom operating lever 26A causes a pilot pressure commensurate with
the amount of operation to act on the right pilot port of the
control valve 175R.
[0098] An operating pressure sensor 29A, which is an example of the
operating pressure sensor 29, detects the details of the operator's
operation of the boom operating lever 26A in the form of pressure,
and outputs the detected value to the controller 30. Examples of
the operation details include the direction of operation and the
amount of operation (the angle of operation).
[0099] Proportional valves 31AL and 31AR constitute a boom
proportional valve 31A, which is an example of the proportional
valve 31. Shuttle valves 32AL and 32AR constitute a boom shuttle
valve 32A, which is an example of the shuttle valve 32. The
proportional valve 31AL operates in response to a current command
controlled by the controller 30. The controller 30 controls a pilot
pressure generated by hydraulic oil introduced to the right pilot
port of the control valve 175L and the left pilot port of the
control valve 175R from the pilot pump 15 via the proportional
valve 31AL and the shuttle valve 32AL. The proportional valve 31AR
operates in response to a current command controlled by the
controller 30. The controller 30 controls a pilot pressure
generated by hydraulic oil introduced to the right pilot port of
the control valve 175R from the pilot pump 15 via the proportional
valve 31AR and the shuttle valve 32AR. The proportional valves 31AL
and 31AR can control the pilot pressures such that the control
valves 175L and 175R can stop at a desired valve position.
[0100] According to this configuration, during the automatic
excavation control, the controller 30 can supply hydraulic oil
discharged by the pilot pump 15 to the right pilot port of the
control valve 175L and the left pilot port of the control valve
175R through the proportional valve 31AL and the shuttle valve
32AL, independent of the operator's boom raising operation. That
is, the controller 30 can automatically raise the boom 4.
Furthermore, the controller 30 can supply hydraulic oil discharged
by the pilot pump 15 to the right pilot port of the control valve
175R through the proportional valve 31AR and the shuttle valve
32AR, independent of the operator's boom lowering operation. That
is, the controller 30 can automatically lower the boom 4.
[0101] An arm operating lever 26B is an example of the operating
apparatus 26 and is used to operate the aim 5. The arm operating
lever 26B uses hydraulic oil discharged by the pilot pump 15 to
cause a pilot pressure commensurate with the details of an
operation to act on pilot ports of the control valves 176L and
176R. Specifically, when operated in an arm opening direction, the
arm operating lever 26B causes a pilot pressure commensurate with
the amount of operation to act on the left pilot port of the
control valve 176L and the right pilot port of the control valve
176R. When operated in an aim closing direction, the arm operating
lever 26B causes a pilot pressure commensurate with the amount of
operation to act on the right pilot port of the control valve 176L
and the left pilot port of the control valve 176R.
[0102] An operating pressure sensor 29B, which is an example of the
operating pressure sensor 29, detects the details of the operator's
operation of the aim operating lever 26B in the form of pressure,
and outputs the detected value to the controller 30.
[0103] Proportional valves 31BL and 31BR constitute an arm
proportional valve 31B, which is an example of the proportional
valve 31. Shuttle valves 32BL and 32BR constitute an arm shuttle
valve 32B, which is an example of the shuttle valve 32. The
proportional valve 31BL operates in response to a current command
controlled by the controller 30. The controller 30 controls a pilot
pressure generated by hydraulic oil introduced to the right pilot
port of the control valve 176L and the left pilot port of the
control valve 176R from the pilot pump 15 via the proportional
valve 31BL and the shuttle valve 32BL. The proportional valve 31BR
operates in response to a current command controlled by the
controller 30. The controller 30 controls a pilot pressure
generated by hydraulic oil introduced to the left pilot port of the
control valve 176L and the right pilot port of the control valve
176R from the pilot pump 15 via the proportional valve 31BR and the
shuttle valve 32BR. The proportional valves 31BL and 31BR can
control the pilot pressures such that the control valves 176L and
176R can stop at a desired valve position.
[0104] According to this configuration, the controller 30 can
supply hydraulic oil discharged by the pilot pump 15 to the right
pilot port of the control valve 176L and the left pilot port of the
control valve 176R through the proportional valve 31BL and the
shuttle valve 32BL, independent of the operator's arm closing
operation. That is, the controller 30 can automatically close the
arm 5. Furthermore, the controller 30 can supply hydraulic oil
discharged by the pilot pump 15 to the left pilot port of the
control valve 176L and the right pilot port of the control valve
176R through the proportional valve 31BR and the shuttle valve
32BR, independent of the operator's arm opening operation. That is,
the controller 30 can automatically open the arm 5.
[0105] Because of this, according to the automatic excavation
control, the arm cylinder 8 and the boom cylinder 7 automatically
operate in accordance with the amount of operation of the am
operating lever 26B, so that the speed or position of the working
part is controlled.
[0106] The shovel 100 may also be configured to automatically turn
the upper turning body 3 clockwise and counterclockwise, be
configured to automatically open and close the bucket 6, and be
configured to automatically move the lower traveling body 1 forward
and backward. In this case, part of the hydraulic system related to
the turning hydraulic motor 2A, part of the hydraulic system
related to the operation of the bucket cylinder 9, part of the
hydraulic system related to the operation of the left side
traveling hydraulic motor 1L, and part of the hydraulic system
related to the operation of the right side traveling hydraulic
motor 1R may be configured the same as part of the hydraulic system
related to the operation of the boom cylinder 7, etc.
[0107] Next, automatic control executed by the controller 30 is
described in detail with reference to FIG. 4. FIG. 4 is a block
diagram illustrating an example of the relationship between
functional elements F1 through F6 associated with the execution of
automatic control in the controller 30.
[0108] As illustrated in FIG. 4, the controller 30 includes the
functional elements F1 through F6 associated with the execution of
automatic control. The functional elements may be constituted of
software, hardware, or a combination of software and hardware.
[0109] The functional element F1 is configured to analyze an
operation tendency that is the tendency of the operator's manual
operation. According to this embodiment, the functional element F1
analyzes the operation tendency based on operational data output by
the operating pressure sensor 29, and outputs the analysis result
together with the operational data. Examples of operation
tendencies includes an operation tendency to rectilinearly move the
teeth tips of the bucket 6 toward the body, an operation tendency
to rectilinearly move the teeth tips of the bucket 6 away from the
body, an operation tendency to rectilinearly raise the teeth tips
of the bucket 6, and an operation tendency to rectilinearly lower
the teeth tips of the bucket 6. The functional element F1 outputs
whether a current operation tendency matches any of the operation
tendencies as the analysis result.
[0110] The functional element F2 is configured to generate an
intended trajectory. According to this embodiment, the functional
element F2 refers to design data stored in the storage device 47
and generates a trajectory to be followed by the teeth tips of the
bucket 6 during slope finishing work.
[0111] The functional element F3 is configured to be able to switch
the operating mode of the shovel 100. According to this embodiment,
the functional element F3 switches the operating mode of the shovel
100 from the manual control mode to the automatic control mode in
response to receiving an ON command from the MC switch 42A, and
switches the operating mode of the shovel 100 from the automatic
control mode to the manual control mode in response to receiving an
OFF command from the MC stop switch 42B.
[0112] Furthermore, the functional element F3 may switch the
operating mode of the shovel 100 from the automatic control mode to
the manual control mode based on the analysis result of the
operation tendency that is the output of the functional element F1.
For example, the functional element F3 may switch the operating
mode of the shovel 100 from the automatic control mode to the
manual control mode in response to determining that the
"information on the movement of the shovel 100 shows an unusual
tendency" as described above based on the analysis result of the
operation tendency that is the output of the functional element
F1.
[0113] When the automatic control mode is selected, the operational
data and the analysis result of the operation tendency that are the
outputs of the functional element F1 are supplied to the functional
element F5. When the manual control mode is selected, the
operational data among the outputs of the functional element F1 are
supplied to the functional element F6.
[0114] The functional element F4 is configured to calculate a
current teeth tips position. According to this embodiment, the
functional element F4 calculates the coordinate point of the teeth
tips of the bucket 6 as a current teeth tips position, based on a
boom angle .alpha. detected by the boom angle sensor S1, an arm
angle .beta. detected by the arm angle sensor S2, and a bucket
angle .gamma. detected by the bucket angle sensor S3. The
functional element F4 may use the output of the body tilt sensor S4
in calculating the current teeth tips position.
[0115] The functional element F5 is configured to calculate the
next teeth tips position when the automatic control mode is
selected. According to this embodiment, when the automatic control
mode is selected, the functional element F5 calculates a teeth tips
position after a predetermined time as an intended teeth tips
position, based on the operational data and the analysis result of
the operation tendency output by the functional element F1, the
intended trajectory generated by the functional element F2, and the
current teeth tips position calculated by the functional element
F4.
[0116] The functional element F6 is configured to calculate a
command value for operating an actuator.
[0117] According to this embodiment, when the automatic control
mode is selected, the functional element F6 calculates at least one
of a boom command value .alpha.*, an arm command value .beta.*, and
a bucket command value .gamma.* based on the intended teeth tips
position calculated by the functional element F5, in order to move
the current teeth tips position to the intended teeth tips
position.
[0118] Furthermore, when the manual control mode is selected, the
functional element F6 calculates at least one of the boom command
value .alpha.*, the aim command value .beta.*, and the bucket
command value .gamma.* based on the operational data in order to
achieve the movement of the actuator corresponding to the
operational data.
[0119] When the automatic control mode is selected, the functional
element F6 calculates the boom command value .alpha.* on an
as-needed basis even when the boom operating lever 26A is not
operated, in order to automatically operate the boom 4. The same is
true for the aim 5 and the bucket 6.
[0120] When the manual control mode is selected, the functional
element F6 does not calculate the boom command value .alpha.* when
the boom operating lever 26A is not operated. This is because
according to the manual control mode, the boom 4 is not operated
unless the boom operating lever 26A is operated. The same is true
for the aim 5 and the bucket 6.
[0121] Next, the functional element F6 is described in detail with
reference to FIG. 5. FIG. 5 is a block diagram illustrating an
example configuration of the functional element F6 that calculates
various command values.
[0122] As illustrated in FIG. 5, the controller 30 further includes
functional elements F11 through F13, F21 through F23, and F31
through F33 associated with generation of command values. The
functional elements may be constituted of software, hardware, or a
combination of software and hardware.
[0123] The functional elements F11 through F13 are functional
elements associated with the boom command value .alpha.*. The
functional elements F21 through F23 are functional elements
associated with the arm command value .beta.*. The functional
elements F31 through F33 are functional elements associated with
the bucket command value .gamma.*.
[0124] The functional elements F11, F21, and F31 are configured to
generate a current command output to the proportional valve 31.
According to this embodiment, the functional element F11 outputs a
boom current command to the boom proportional valve 31A (see FIG.
3), the functional element F21 outputs an arm current command to
the arm proportional valve 31B (see FIG. 3), and the functional
element F31 outputs a bucket current command to a bucket
proportional valve 31C.
[0125] The functional elements F12, F22, and F32 are configured to
calculate the amount of displacement of a spool that is a
constituent of a spool valve. According to this embodiment, the
functional element F12 calculates the amount of displacement of a
boom spool that is a constituent of the control valve 175
pertaining to the boom cylinder 7 based on the output of a boom
spool displacement sensor S11. The functional element F22
calculates the amount of displacement of an arm spool that is a
constituent of the control valve 176 pertaining to the arm cylinder
8 based on the output of an arm spool displacement sensor S12. The
functional element F13 calculates the amount of displacement of a
bucket spool that is a constituent of the control valve 174
pertaining to the bucket cylinder 9 based on the output of a bucket
spool displacement sensor S13.
[0126] The functional elements F13 through F23 are configured to
calculate the rotation angle of a working body. According to this
embodiment, the functional element F13 calculates the boom angle
.alpha. based on the output of the boom angle sensor S1. The
functional element F23 calculates the arm angle .beta. based on the
arm angle sensor S2. The functional element F33 calculates the
bucket angle .gamma. based on the output of the bucket angle sensor
S3.
[0127] Specifically, the functional element F11 basically so
generates the boom current command to the boom proportional valve
31A as to eliminate the difference between the boom command value
.alpha.* generated by the functional element F6 and the boom angle
.alpha. calculated by the functional element F13. At this point,
the functional element F11 so adjusts the boom current command as
to eliminate the difference between an intended boom spool
displacement amount derived from the boom current command and the
boom spool displacement amount calculated by the functional element
F12. The functional element F11 outputs the adjusted boom current
command to the boom proportional valve 31A.
[0128] The boom proportional valve 31A changes the opening area in
accordance with the boom current command to cause a pilot pressure
commensurate with the size of the boom current command to act on a
pilot port of the control valve 175. The control valve 175 moves
the boom spool in accordance with the pilot pressure to cause
hydraulic oil to flow into the boom cylinder 7. The boom spool
displacement sensor S11 detects the displacement of the boom spool
and feeds the detection result back to the functional element F12
of the controller 30. The boom cylinder 7 extends or retracts
according as hydraulic oil flows in to move up or down the boom 4.
The boom angle sensor S1 detects the rotation angle of the
vertically moving boom 4 and feeds the detection result back to the
functional element F13 of the controller 30. The functional element
F13 feeds the calculated boom angle .alpha. back to the functional
element F4.
[0129] The functional element F21 basically so generates the arm
current command to the arm proportional valve 31B as to eliminate
the difference between the arm command value .beta.* generated by
the functional element F6 and the arm angle .beta. calculated by
the functional element F23. At this point, the functional element
F21 so adjusts the arm current command as to eliminate the
difference between an intended arm spool displacement amount
derived from the arm current command and the arm spool displacement
amount calculated by the functional element F22. The functional
element F21 outputs the adjusted arm current command to the arm
proportional valve 31B.
[0130] The arm proportional valve 31B changes the opening area in
accordance with the arm current command to cause a pilot pressure
commensurate with the size of the arm current command to act on a
pilot port of the control valve 176. The control valve 176 moves
the arm spool in accordance with the pilot pressure to cause
hydraulic oil to flow into the arm cylinder 8. The arm spool
displacement sensor S12 detects the displacement of the arm spool
and feeds the detection result back to the functional element F22
of the controller 30. The arm cylinder 8 extends or retracts
according as hydraulic oil flows in to open or close the arm 5. The
arm angle sensor S2 detects the rotation angle of the opening or
closing arm 5 and feeds the detection result back to the functional
element F23 of the controller 30. The functional element F23 feeds
the calculated arm angle .beta. back to the functional element
F4.
[0131] Likewise, the functional element F31 basically so generates
the bucket current command to the bucket proportional valve 31C as
to eliminate the difference between the bucket command value
.gamma.* generated by the functional element F6 and the bucket
angle .gamma. calculated by the functional element F33. At this
point, the functional element F31 so adjusts the bucket current
command as to eliminate the difference between an intended bucket
spool displacement amount derived from the bucket current command
and the bucket spool displacement amount calculated by the
functional element F32. The functional element F31 outputs the
adjusted bucket current command to the bucket proportional valve
31C.
[0132] The bucket proportional valve 31C changes the opening area
in accordance with the bucket current command to cause a pilot
pressure commensurate with the size of the bucket current command
to act on a pilot port of the control valve 174. The control valve
174 moves the bucket spool in accordance with the pilot pressure to
cause hydraulic oil to flow into the bucket cylinder 9. The bucket
spool displacement sensor S13 detects the displacement of the
bucket spool and feeds the detection result back to the functional
element F32 of the controller 30. The bucket cylinder 9 extends or
retracts according as hydraulic oil flows in to open or close the
bucket 6. The bucket angle sensor S3 detects the rotation angle of
the opening or closing bucket 6 and feeds the detection result back
to the functional element F33 of the controller 30. The functional
element F33 feeds the calculated bucket angle .gamma. back to the
functional element F4.
[0133] As described above, the controller 30 forms a three-stage
feedback loop for each working body. That is, the controller 30
forms a feedback loop associated with the amount of spool
displacement, a feedback loop associated with the rotation angle of
a working body, and a feedback loop associated with the teeth tips
position. Therefore, the controller 30 can control the movement of
the teeth tips of the bucket 6 with high accuracy during automatic
control.
[0134] Next, an effect produced by the emergency stop function is
described with reference to FIGS. 6 through 9. FIGS. 6 through 9
relate to the movement of the shovel 100 when part LP (see FIG. 7)
of the ground supporting the shovel 100 collapses during slope
finishing work. Specifically, FIGS. 6 through 9 relate to the
movement of the shovel 100 when the operator performs an arm
opening operation out of reflex to prevent the tipping of the
shovel 100 in response to the forward tilting of the shovel 100 due
to the collapse of the part LP of the ground under the front end of
the lower traveling body 1. The operator intends to stop the
forward tilting of the shovel 100 by causing the bucket 6 to
contact the slope by opening the arm 5.
[0135] More specifically, FIG. 6 is a diagram illustrating the
state of the hydraulic system when an arm opening operation has
been performed during the automatic excavation control in the
shovel 100 where the emergency stop function is disabled, and
corresponds to FIG. 3. FIG. 7 is a diagram illustrating the
movement of the excavation attachment when an aim opening operation
has been performed during the automatic excavation control in the
shovel 100 where the emergency stop function is disabled, and
corresponds to FIG. 1.
[0136] In the case where the emergency stop function is disabled,
when the arm operating lever 26B is operated in the arm opening
direction with the MC switch 42A being pressed as illustrated in
FIG. 6, the hydraulic system increases a pilot pressure that acts
on each of the left pilot port of the control valve 176L and the
right pilot port of the control valve 176R in order to retract the
arm cylinder 8 to open the arm 5. Therefore, the arm 5 opens as
intended by the operator as indicated by arrow AR1 of FIG. 7.
[0137] At this point, the controller 30 detects the operation of
the aim operating lever 26B in the arm opening direction based on
the output of the operating pressure sensor 29B. As the shovel 100
tilts forward, the teeth tips of the bucket 6 move toward the
intended work surface. Therefore, the controller 30 performs a boom
raising operation to prevent the teeth tips of the bucket 6 from
moving down below the intended work surface. Specifically, the
controller 30 outputs a control command to the proportional valve
31AL to cause a predetermined pilot pressure to act on each of the
right pilot port of the control valve 175L and the left pilot port
of the control valve 175R, in order to extend the boom cylinder 7
to raise the boom 4 according as the arm 5 opens. Therefore,
contrary to the operator's intention, the boom 4 rises as indicated
by arrow AR2 of FIG. 7, and the vertical distance between the teeth
tips of the bucket 6 and an intended work surface TS is maintained
at a value Dl against the operator's intention as illustrated in
FIG. 7. That is, the operator cannot support the shovel 100 by
causing the bucket 6 to contact the slope. As a result, the shovel
100 further tilts forward as indicated by arrow A3 of FIG. 7.
[0138] In contrast, in the case where the emergency stop function
is enabled, the controller 30 can prevent the excavation attachment
from automatically moving against the operator's intention as
described above. FIG. 8 is a diagram illustrating the state of the
hydraulic system when an arm opening operation has been performed
during the automatic excavation control in the shovel 100 where the
emergency stop function is enabled, and corresponds to FIG.
[0139] 3. FIG. 9 is a diagram illustrating the movement of the
excavation attachment when an arm opening operation has been
performed during the automatic excavation control in the shovel 100
where the emergency stop function is enabled, and corresponds to
FIG. 1.
[0140] In the case where the emergency stop function is enabled,
when the arm operating lever 26B is operated in the arm opening
direction as illustrated in FIG. 8, the hydraulic system increases
a pilot pressure that acts on each of the left pilot port of the
control valve 176L and the right pilot port of the control valve
176R in order to retract the arm cylinder 8 to open the arm 5, the
same as in the case where the emergency stop function is disabled.
Therefore, the arm 5 opens as intended by the operator as indicated
by arrow AR4 of FIG. 9.
[0141] At this point, the controller 30 detects the operation of
the arm operating lever 26B in the arm opening direction based on
the output of the operating pressure sensor 29B. Then, the
controller 30 determines whether a predetermined condition for
stopping automatic control is satisfied. For example, the
controller 30 determines that the predetermined condition is
satisfied when the operation speed of the arm operating lever 26B
in the arm opening direction exceeds a predetermined speed. In
response to determining that the predetermined condition is
satisfied, the controller 30 stops automatic control. Thus, even
during automatic control, the controller 30 can switch the
operating mode of the shovel 100 from the automatic control mode to
the manual control mode.
[0142] When automatic control is stopped, unlike in the case where
the emergency stop function is disabled, the controller 30 does not
output a control command to the proportional valve 31AL. Therefore,
the controller 30 does not cause a predetermined pilot pressure to
act on each of the right pilot port of the control valve 175L and
the left pilot port of the control valve 175R. That is, the
controller 30 does not extend the boom cylinder 7 and does not
raise the boom 4 according as the arm 5 opens. That is, as
illustrated in FIG. 9, the boom 4 does not rise contrary to the
operator's intention. As a result, the vertical distance between
the teeth tips of the bucket 6 and the intended work surface TS is
reduced as the arm 5 opens as intended by the operator, and becomes
zero when the arm angle reaches a certain angle. That is, the
operator can prevent the shovel 100 from further tilting forward by
causing the teeth tips of the bucket 6 to contact the slope as
illustrated in FIG. 9.
[0143] Next, the same effect produced by the emergency stop
function is described with reference to FIGS. 10 and 11. FIGS. 10
and 11 relate to the movement of the shovel 100 when the part LP of
the ground supporting the shovel 100 collapses during slope
finishing work with an arm closing operation. Specifically, FIGS.
10 and 11 relate to the movement of the shovel 100 when the
operator performs a boom lowering operation out of reflex to
prevent the tipping of the shovel 100 in response to the forward
tilting of the shovel 100 due to the collapse of the part LP of the
ground under the front end of the lower traveling body 1. The
operator intends to stop the forward tilting of the shovel 100 by
causing the bucket 6 to contact the slope by lowering the boom
4.
[0144] In the case where the emergency stop function is enabled,
the controller 30 can prevent the excavation attachment from
automatically moving against the operator's intention when the
operator has performed a boom lowering operation out of reflex, the
same as in the case where the operator has performed an arm opening
operation out of reflex. FIG. 10 illustrates the state of the
hydraulic system when a boom lowering operation has been performed
during the automatic excavation control in the shovel 100 where the
emergency stop function is enabled. FIG. 11 illustrates the
movement of the excavation attachment when a boom lowering
operation has been performed during the automatic excavation
control in the shovel 100 where the emergency stop function is
enabled.
[0145] In response to detecting the operation of the boom operating
lever 26A in the boom lowering direction based on the output of the
operating pressure sensor 29A, the controller 30 determines whether
a predetermined condition for stopping automatic control is
satisfied. For example, the controller 30 determines that the
predetermined condition is satisfied when the operation speed of
the boom operating lever 26A in the boom lowering direction exceeds
a predetermined speed. In response to determining that the
predetermined condition is satisfied, the controller 30 stops
automatic control.
[0146] When automatic control is stopped, the hydraulic system
increases a pilot pressure that acts on the right pilot port of the
control valve 175R in order to retract the boom cylinder 7 to lower
the boom 4, in response to the operation of the boom operating
lever 26A in the boom lowering direction as illustrated in FIG. 10.
Therefore, the boom 4 lowers as intended by the operator as
indicated by arrow AR5 of FIG. 11. The arm 5 does not automatically
move as the boom 4 lowers.
[0147] As a result, the distance between the teeth tips of the
bucket 6 and the intended work surface TS is reduced as the boom 4
lowers as intended by the operator, and becomes zero when the arm
angle reaches a certain angle. That is, the operator can prevent
the shovel 100 from further tilting forward by causing the teeth
tips of the bucket 6 to contact the slope as illustrated in FIG.
11.
[0148] According to the above-described configuration, the
controller 30 stops automatic control when the boom operating lever
26A or the arm operating lever 26B is rapidly operated. The
controller 30, however, may stop automatic control in response to
detecting that the pitch angle of the upper turning body 3 is more
than or equal to a predetermined angle based on the output of the
body tilt sensor S4. The controller 30 may also stop automatic
control when the emergency stop switch 48, which is a foot switch
installed at the operator's feet in the cabin 10, is stepped on.
The controller 30 may also stop automatic control when the MC stop
switch 42B is pressed. In these cases as well, the operator can
stop the forward tilting of the shovel 100 by causing the bucket 6
to contact the slope by opening the aim 5 or by lowering the boom
4, for example.
[0149] Thus, the shovel 100 according to an embodiment of the
present invention includes the lower traveling body 1, the upper
turning body 3 turnably mounted on the lower traveling body 1, the
excavation attachment serving as an attachment attached to the
upper turning body 3, and the controller 30 mounted on the upper
turning body 3 to serve as a control device that can perform
automatic control. The controller 30 is configured to stop
automatic control when information on the movement of the shovel
100 or information on the state of a nearby machine shows an
unusual tendency. When the information on the movement of the
shovel 100 shows an unusual tendency corresponds to, for example,
when the operator may be unable to press the bucket 6 against an
upward inclined surface as intended by the operator. The automatic
control may be, for example, the automatic excavation control. The
automatic control may also be, for example, control to move the
working part along an intended trajectory. This configuration
enables the shovel 100 to move as intended by the operator even
during automatic control.
[0150] The "information on the movement of the shovel 100" may be,
for example, information on the operation of the operating
apparatus 26 mounted on the upper turning body 3. The controller 30
may be configured to determine that the "information on the
movement of the shovel 100 shows an unusual tendency" when the
operating apparatus 26 is rapidly operated, for example. "When the
operating apparatus 26 is rapidly operated" includes, for example,
when the amount of operation per unit time of the arm operating
lever serving as the operating apparatus 26 exceeds a predetermined
value. The amount of operation per unit time of the arm operating
lever may be, for example, the inclination angle per unit time of
the arm operating lever.
[0151] The automatic control may be, for example, either the
automatic straight facing control or the automatic complex turning
control. The "information on the movement of the shovel 100" may be
information on the operation of the turning operating lever mounted
on the upper turning body 3. In this case, the controller 30 may be
configured to determine that the "information on the movement of
the shovel 100 shows an unusual tendency" when an operation to turn
the upper turning body 3 in a direction opposite to that of turning
performed by automatic control is performed.
[0152] Next, automatic control executed by the controller 30 is
described in detail with reference to
[0153] FIGS. 12 and 13. FIG. 12 is a block diagram illustrating
another example of the relationship between the functional elements
F1 through F6 associated with the execution of automatic control in
the controller 30, and corresponds to FIG. 4. FIG. 13 is a block
diagram illustrating another example configuration of the
functional element F6 that calculates various command values.
[0154] The configuration of FIG. 12 is different in that the
functional element F2 generates the intended trajectory based on
the output of the space recognition device S7, that the functional
element F4 obtains a turning angle .delta., and that the functional
element F6 calculates a turning command value .delta.* from, but
otherwise equal to, the configuration of FIG. 4. Furthermore, the
configuration of FIG. 13 is different in including a functional
element associated with automatic control of the turning hydraulic
motor 2A from, but otherwise equal to, the configuration of FIG. 5.
Therefore, the description of a common portion is omitted, and
differences are described in detail.
[0155] According to the illustration of FIGS. 12 and 13, the
functional element F2 generates a trajectory to be followed by the
teeth tips of the bucket 6 as an intended trajectory, based on
object data detected by the space recognition device S7. The object
data are, for example, information on an object present in an area
surrounding the shovel 100, such as the position, shape, etc., of a
dump truck.
[0156] The functional element F4 calculates the coordinate point of
the bucket 6 as a current teeth tips position, based on the boom
angle .alpha., the arm angle .beta., the bucket angle .gamma., and
the turning angle .delta. calculated from the output of the turning
angular velocity sensor S5. The functional element F4 may use the
output of the body tilt sensor S4 in calculating the current teeth
tips position.
[0157] When the automatic control mode is selected, the functional
element F6 calculates at least one of the boom command value
.alpha.*, the arm command value .beta.*, the bucket command value
.gamma.*, and the turning command value .delta.* based on the
intended teeth tips position calculated by the functional element
F5, in order to move the current teeth tips position to the
intended teeth tips position.
[0158] Functional elements F41 through F43 are functional elements
associated with the turning command value .delta.*. Specifically,
the functional element F41 outputs a turning current command to a
turning proportional valve 31D. The functional element F42
calculates the amount of displacement of a turning spool that is a
constituent of the control valve 173 pertaining to the turning
hydraulic motor 2A based on the output of a turning spool
displacement sensor S14. The functional element F43 calculates the
turning angle .delta. based on the output of the turning angular
velocity sensor S5.
[0159] The functional element F41 basically so generates the
turning current command to the turning proportional valve 31D as to
eliminate the difference between the turning command value .delta.*
generated by the functional element F6 and the turning angle
.delta. calculated by the functional element F43. At this point,
the functional element F41 so adjusts the turning current command
as to eliminate the difference between an intended turning spool
displacement amount derived from the turning current command and
the turning spool displacement amount calculated by the functional
element F42. The functional element F41 outputs the adjusted
turning current command to the turning proportional valve 31D.
[0160] The turning proportional valve 31D changes the opening area
in accordance with the turning current command to cause a pilot
pressure commensurate with the size of the turning current command
to act on a pilot port of the control valve 173. The control valve
173 moves the turning spool in accordance with the pilot pressure
to cause hydraulic oil to flow into the turning hydraulic motor 2A.
The turning spool displacement sensor S14 detects the displacement
of the turning spool and feeds the detection result back to the
functional element F42 of the controller 30. The turning hydraulic
motor 2A rotates according as hydraulic oil flows in to turn the
upper turning body 3. The turning angular velocity sensor S5
detects the rotation angle of the turning upper turning body 3 and
feeds the detection. result back to the functional element F43 of
the controller 30. The functional element F43 feeds the calculated
turning angle .delta. back to the functional element F4.
[0161] As described above, the controller 30 according to FIGS. 12
and 13 forms a three-stage feedback loop with respect to not only
the boom angle .alpha., the aim angle .beta., and the bucket angle
.gamma., but also the turning angle .delta.. That is, the
controller 30 forms a feedback loop associated with the turning
spool displacement amount, a feedback loop associated with the
rotation angle of the upper turning body 3, and a feedback loop
associated with the teeth tips position. Therefore, the controller
30 can control the movement of the teeth tips of the bucket 6 with
high accuracy during automatic control.
[0162] Next, the automatic complex turning control is described
with reference to FIGS. 14 and 15. FIGS. 14 and 15 illustrate the
movement of the excavation attachment during the work of loading
the bed of a dump truck DT with soil. FIG. 14 is a plan view of a
work site. FIG. 15 is a side view of the work site as seen from the
+Y side. For clarification, FIG. 15 omits graphical representation
of the shovel 100 (except for the bucket 6).
[0163] In FIGS. 14 and 15, the excavation attachment indicated by a
solid line shows the state of the excavation attachment at the
completion of an excavating operation, the excavation attachment
indicated by a dotted line shows the state of the excavation
attachment during a turning operation, and the excavation
attachment indicated by a one-dot chain line shows the state of the
excavation attachment immediately before performance of a soil
dumping operation.
[0164] Point P11 indicates the central point of the back surface of
the bucket 6 at the completion of an excavating operation. Point
P12 indicates the central point of the back surface of the bucket 6
during a turning operation. Point P13 indicates the central point
of the back surface of the bucket 6 immediately before performance
of a soil dumping operation. The thick dashed line connecting Point
P11, Point P12, and Point P13 indicates a trajectory followed by
the central point of the back surface of the bucket 6. The soil
dumping operation is an operation to dump soil in the bucket 6 onto
the bed of the dump truck DT.
[0165] According to the automatic complex turning control, for
example, the automatic control part 54 automatically extends or
retracts at least one of the boom cylinder 7, the arm cylinder 8,
and the bucket cylinder 9 such that the central point of the back
surface of the bucket 6 moves along a predetermined trajectory,
while the operator is manually performing a turning operation. The
predetermined trajectory is, for example, an intended trajectory
calculated based on information on the dump truck DT including the
position, shape, etc., of the dump truck DT. The information on the
dump truck DT as a nearby machine is obtained based on, for
example, the output of at least one of the space recognition device
S7, the communications device T1, etc. In this case, by only
operating the turning operating lever, the operator can move the
central point of the back surface of the bucket 6 along the
predetermined trajectory. That is, by only operating the turning
operating lever, the operator can move the bucket 6 near the ground
to a position over the bed of the dump truck DT at a height Hd
while preventing contact between the excavation attachment and the
dump truck DT. By operating the turning operating lever, the
operator can move the bucket 6 over the bed of the dump truck DT at
the height Hd to a position near the ground while preventing
contact between the excavation attachment and the dump truck DT. A
trajectory used during clockwise turning (during boom raising and
turning) may be either equal to or different from a trajectory used
during counterclockwise turning (during boom lowering and
turning).
[0166] Next, the emergency stop function associated with the
automatic complex turning control is described. This emergency stop
function is executed, for example, in response to the shovel 100
operator's reflexive counterclockwise turning operation when the
dump truck DT starts to move while the operator is performing a
clockwise turning operation to load the bed of the dump truck DT
with soil. Specifically, this emergency stop function is executed,
for example, in response to the operator's reflexive
counterclockwise turning operation to prevent contact between the
shovel 100 and the dump truck DT when the dump truck DT that has
been stopped suddenly starts to move backward. In this case, the
operator intends to move the bucket 6 away from the dump truck DT
while maintaining the height of the bucket 6 by turning the upper
turning body 3 turning clockwise in the opposite counterclockwise
direction.
[0167] For example, when the turning operating lever is rapidly
operated in a opposite direction, the automatic control part 54
determines that the "information on the movement of the shovel 100
shows an unusual tendency" and stops the automatic complex turning
control.
[0168] When the emergency stop function is disabled, that is, when
the automatic complex turning control is not stopped, the automatic
control part 54 moves the central point of the back surface of the
bucket 6 along the predetermined trajectory even when the turning
operating lever is rapidly operated leftward, and therefore lowers
the bucket 6 contrary to the operator's intention. The figure
indicated by crosshatching in FIG. 15 indicates the position of the
bucket 6 whose height is reduced. That is, FIG. 15 illustrates that
the bucket 6 at the height of a figure indicated by a dotted line
lowers to the height of the figure indicated by crosshatching.
[0169] In contrast, when the emergency stop function is enabled,
that is, when the automatic complex turning control is stopped, the
automatic control part 54 can cause the central point of the back
surface of the bucket 6 to deviate from the predetermined
trajectory to move the bucket 6 in response to the leftward rapid
operation of the turning operating lever. Therefore, the automatic
control part 54 can move the bucket 6 leftward while maintaining
the height of the bucket 6 as intended by the operator instead of
lowering the bucket 6 against the operator's intention. The figure
indicated by oblique line hatching in FIG. 15 indicates the
position of the bucket 6 that has been moved leftward while keeping
the height. That is, FIG. 15 illustrates that the bucket 6 at the
height of a figure indicated by a dotted line moves to the position
of the figure indicated by oblique line hatching while remaining at
the same height.
[0170] Thus, in the case where the emergency stop function is
enabled, when the operator performs a counterclockwise turning
operation out of reflex, the controller 30 can prevent the
excavation attachment from automatically moving against the
operator's operation.
[0171] The controller 30 may be configured to detect the start of
the movement (for example, the start of the backward travel) of the
dump truck DT based on the output of the space recognition device
S7. In this case, after identifying what work a currently performed
work is based on the outputs of various sensors, the controller 30
obtains information on the normal state of a nearby machine
associated with the work, recorded in advance work by work. For
example, in the case of having successfully identified that the
currently performed work is loading work that loads the bed of the
dump truck DT with soil, the controller 30 obtains information that
the normal state of the dump truck DT that is a nearby machine
associated with the loading work is a stopped state. When the dump
truck DT starts to move during the loading work, the controller 30
can determine that the dump truck DT is in a state different from
the normal state. Based on this determination result, the
controller 30 can stop automatic control.
[0172] Furthermore, the operating mode of the shovel 100 may
include a stop mode, apart from the manual control mode and the
automatic control mode. According to this configuration, when the
teeth tips of the bucket 6 as the working part are in a region
other than the region above the bed of the dump truck DT, the
controller 30 may stop automatic control and thereafter switch the
operating mode of the shovel 100 from the automatic control mode to
the stop mode, in response to detecting the start of the movement
of the dump. truck DT. During the stop mode, the controller 30 may
stop the movement of the working part in a space between Point P11,
indicating the central point of the back surface of the bucket 6 at
the completion of an excavating operation, and the dump truck DT,
irrespective of whether the operating apparatus 26 is operated.
This is for preventing contact between the working part and the
dump truck DT by keeping the working part on standby until the dump
truck DT stops, namely, by forcibly arresting the movement of the
working part until the dump truck DT stops.
[0173] Thus, when detecting the start of the movement of the dump
truck DT during the loading work, the controller 30 may switch the
operating mode of the shovel 100 from the automatic control mode to
the stop mode.
[0174] The operating mode of the shovel 100 may include an
avoidance mode, apart from the manual control mode and the
automatic control mode. The controller 30 may switch the operating
mode of the shovel 100 from the automatic control mode to the
avoidance mode, for example, when detecting the start of the
movement of the dump truck DT during the loading work and the teeth
tips of the bucket 6 as the working part are within a region above
the bed of the dump truck DT. During the avoidance mode, the
controller 30 may move the teeth tips of the bucket 6 aside to a
space between Point P11, indicating the central point of the back
surface of the bucket 6 at the completion of an excavating
operation, and the dump truck DT, by automatically moving various
hydraulic actuators, irrespective of whether the operating
apparatus 26 is operated. This is for preventing contact between
the working part and the dump truck DT by forcing the working part
to move from inside and stay outside a region above the bed of the
dump truck DT until the dump truck DT stops.
[0175] Thus, when detecting the start of the movement of the dump
truck DT during the loading work, the controller 30 may switch the
operating mode of the shovel 100 from the automatic control mode to
the avoidance mode.
[0176] The shovel 100 may include a switch related to automatic
control, such as the MC switch 42A. In this case, the controller 30
may be configured to execute automatic control when the switch is
operated.
[0177] Furthermore, the illustration of FIG. 3 discloses a
hydraulic operation system including a hydraulic pilot circuit. For
example, according to a hydraulic pilot circuit associated with the
boom operating lever 26A, hydraulic oil supplied from the pilot
pump 15 to a remote control valve 27A is supplied to a pilot port
of the control valve 175 at a flow rate commensurate with the
opening degree of the remote control valve 27A opened by the tilt
of the boom operating lever 26A. According to a hydraulic pilot
circuit associated with the arm operating lever 26B, hydraulic oil
supplied from the pilot pump 15 to a remote control valve 27B is
supplied to a pilot port of the control valve 176 at a flow rate
commensurate with the opening degree of the remote control valve
27B opened by the tilt of the aim operating lever 26B.
[0178] Instead of a hydraulic operation system including such a
hydraulic pilot circuit, however, an electric operation system
including an electric operating lever may be adopted. In this case,
the amount of lever operation of the electric operating lever is
input to the controller 30 as an electrical signal. Furthermore, a
solenoid valve is placed between the pilot pump 15 and a pilot port
of each control valve. The solenoid valve is configured to operate
in response to an electrical signal from the controller 30.
[0179] According to this configuration, when a manual operation
using the electric operating lever is performed, the controller 30
can move each control valve by increasing or decreasing a pilot
pressure by controlling the solenoid valve with an electrical
signal commensurate with the amount of lever operation.
[0180] When an electric operation system including an electric
operating lever is adopted, the controller 30 can easily switch the
manual control mode and the automatic control mode. When the
controller 30 switches the manual control mode to the automatic
control mode, control valves may be independently controlled in
response to an electrical signal commensurate with the amount of
lever operation of a single electric operating lever.
[0181] FIG. 16 illustrates an example configuration of an electric
operation system. Specifically, the electric operation system of
FIG. 16 is an example of a boom operation system, and mainly
includes the pilot pressure-operated control valve 17, the boom
operating lever 26A serving as an electric operating lever, the
controller 30, a solenoid valve for boom raising operation, and a
solenoid valve for boom lowering operation. The electric operation
system of FIG. 16 may also be likewise applied to an arm operation
system, a bucket operation system, etc.
[0182] The pilot pressure-operated control valve 17 includes the
control valve 175 (see FIG. 2) pertaining to the boom cylinder 7,
the control valve 176 (see FIG. 2) pertaining to the arm cylinder
8, the control valve 174 (see FIG. 2) pertaining to the bucket
cylinder 9, etc. A solenoid valve 60 is configured to be able to
adjust the flow area of a conduit connecting the pilot pump 15 and
the raising-side pilot port of the control valve 175. A solenoid
valve 62 is configured to be able to adjust the flow area of a
conduit connecting the pilot pump 15 and the lowering-side pilot
port of the control valve 175.
[0183] When a manual operation is performed, the controller 30
generates a boom raising operation signal (an electrical signal) or
a boom lowering operation signal (an electrical signal) in
accordance with an operation signal (electrical signal) output by
an operation signal generating part 26Aa of the boom operating
lever 26A. The operation signal output by the operation signal
generating part 26Aa of the boom operating lever 26A is an
electrical signal that changes in accordance with the amount of
operation and the direction of operation of the boom operating
lever 26A.
[0184] Specifically, when the boom operating lever 26A is operated
in the boom raising direction, the controller 30 outputs a boom
raising operation signal (an electrical signal) commensurate with
the amount of lever operation to the solenoid valve 60. The
solenoid valve 60 adjusts the flow area in accordance with the boom
raising operation signal (electrical signal) to control a pilot
pressure that acts on the raising-side pilot port of the control
valve 175. Likewise, when the boom operating lever 26A is operated
in the boom lowering direction, the controller 30 outputs a boom
lowering operation signal (an electrical signal) commensurate with
the amount of lever operation to the solenoid valve 62. The
solenoid valve 62 adjusts the flow area in accordance with the boom
lowering operation signal (electrical signal) to control a pilot
pressure that acts on the lowering-side pilot port of the control
valve 175.
[0185] In the case of executing automatic control, for example, the
controller 30 generates a boom raising operation signal (an
electrical signal) or a boom lowering operation signal (an
electrical signal) in accordance with a correcting operation signal
(an electrical signal) instead of the operation signal output by
the operation signal generating part 26Aa of the boom operating
lever 26A. The correcting operation signal may be either an
electrical signal generated by the controller 30 or an electrical
signal generated by an external control device different than the
controller 30.
[0186] Furthermore, information obtained by the shovel 100 may be
shared with a manager, other shovel operators, etc., through a
shovel management system SYS as illustrated in FIG. 17. FIG. 17 is
a schematic diagram illustrating an example configuration of the
shovel management system SYS. The management system SYS is a system
that manages the shovel 100. According to this embodiment, the
management system SYS is constituted mainly of the shovel 100, an
assist device 200, and a management apparatus 300. Each of the
shovel 100, the assist device 200, and the management apparatus 300
constituting the management system SYS may be one or more in
number. According to the illustration of FIG. 17, the management
system SYS includes the single shovel 100, the single assist device
200, and the single management apparatus 300.
[0187] The assist device 200 is typically a portable terminal
device, and is, for example, a computer including a processor, such
as a notebook PC, a tablet PC, or a smartphone carried by a worker
or the like at a construction site. The assist device 200 may also
be a computer carried by the operator of the shovel 100. The assist
device 200, however, may also be a stationary terminal device.
[0188] The management apparatus 300 is typically a stationary
terminal device, and is, for example, a server computer including a
processor and installed in a management center or the like outside
a construction site. The management apparatus 300 may also be a
portable computer including a processor (for example, a portable
terminal device such as a notebook PC, a tablet PC, or a
smartphone).
[0189] At least one of the assist device 200 and the management
apparatus 300 (hereinafter, "assist device 200, etc.") may include
a monitor and an operating apparatus for remote control. In this
case, the operator operates the shovel 100 using the operating
apparatus for remote control. The operating apparatus for remote
control is connected to the controller 30 through, for example, a
communications network such as a radio communications network.
[0190] According to the shovel management system SYS as described
above, the controller 30 of the shovel 100 may transmit information
on at least one of the time, location, etc., of the stoppage of
automatic control to the assist device 200, etc. At this point, the
controller 30 may transmit a peripheral image that is an image
captured by the image capturing device S6 to the assist device 200,
etc. The peripheral image may be multiple peripheral images
captured within a predetermined period including the time of the
stoppage of automatic control. Furthermore, the controller 30 may
transmit data on the work details of the shovel 100, data on the
attitude of the shovel 100, data on the posture of the excavation
attachment, etc., within a predetermined period including the time
of the stoppage of automatic control to the assist device 200, etc.
This is for enabling a manager using the assist device 200, etc.,
to obtain information on a work site as illustrated in FIGS. 9, 11,
14 and 15. That is, this is for enabling the manager to analyze the
cause of such an operation as to stop automatic control having been
performed, etc., and further for enabling the manager to improve
the work environment of the shovel 100 based on the results of the
analysis.
[0191] Thus, the management system SYS of the shovel 100 according
to the embodiment of the present invention includes the shovel 100
that stores at least one of the time, location, attitude, and
peripheral image of the stoppage of automatic control executed by
the shovel 100 in the storage device 47 and transmits the stored at
least one of the time, location, attitude, and peripheral image to
the outside with desired timing, and the management apparatus 300
that receives the at least one of the time, location, attitude, and
peripheral image transmitted by the shovel 100 and outputs at least
one of the received attitude and peripheral image. The attitude is,
for example, at least one of the attitude of the shovel 100 when
automatic control is stopped and the posture of the excavation
attachment when automatic control is stopped. The management
apparatus 300 enables the manager to recognize the attitude of the
shovel 100 by, for example, displaying an illustration image on the
monitor. The management apparatus 300 may also enable the manager
to recognize the attitude of the shovel 100 by, for example,
outputting audio information.
[0192] An embodiment of the present invention is described in
detail above. The present invention, however, is not limited to the
above-described embodiment. Various variations, substitutions,
etc., may be applied to the above-described embodiment without
departing from the scope of the present invention. Furthermore, the
separately described features may be suitably combined as long as
no technical contradiction is caused.
[0193] For example, according to the above-described embodiment,
the controller 30 causes the upper turning body 3 to face straight
to the intended work surface by automatically operating the turning
hydraulic motor 2A. The controller 30, however, may also cause the
upper turning body 3 to face straight to the intended work surface
by automatically operating a turning motor generator.
[0194] Furthermore, the operational data, which are generated in
accordance with the operating apparatus or the operating apparatus
for remote control, may also be automatically generated by a
predetermined operation program.
[0195] Furthermore, the controller 30 may also cause the upper
turning body 3 to face straight to the intended work surface by
operating other actuators. For example, the controller 30 may cause
the upper turning body 3 to face straight to the intended work
surface by automatically operating the left side traveling
hydraulic motor 1L and the right side traveling hydraulic motor
1R.
* * * * *