Technical Field
[0001] The present invention relates to a work area setting system for setting a work area
of a work machine.
Background Art
[0002] Patent Literature 1 discloses a technique of calculating a distance from a wheel
loader to the natural ground as an excavation object or an angle of repose of the
natural ground, based on measurement data provided by a three-dimensional measurement
device. The literature, however, does not disclose a technique for facilitating control
for making a work machine perform automatic operation to perform repeated work.
Citation List
Patent Literature
Summary of Invention
[0004] As to making a work machine perform automatic operation to perform repeated work,
dividing the motion of the work machine in the repeated work allows the control of
the work machine for the automatic operation to be easy. Specifically, setting a work
area around a work object (for example, earth-and-sand pile) facilitates the identification
of the work object in the automatic operation control or the like.
[0005] It is an object of the present invention to provide a work area setting system that
allows a work area of a work machine to be easily set.
[0006] Provided is a work area setting system for setting a work area in which a work machine
makes a work motion. The work machine includes a lower traveling body, an upper turning
body mounted on an upper part of the lower traveling body capably of turning around
a vertical turning center axis, and an attachment attached to the upper turning body
capably of rotational movement in a direction along a motion surface that is a plane
extending vertically to make the work motion. The work area setting system includes
a first straight line setting part, a second straight line setting part, and an area
setting part. The first straight line setting part sets a first straight line, which
is a straight line parallel to the motion surface in a plan view in which the work
machine is viewed from above and passes through a first point at which a tip of the
attachment is located when the upper turning body is oriented in a first direction.
The second straight line setting part sets a second straight line, which is a straight
line parallel to the motion surface in the plan view in which the work machine is
viewed from above and passes through a second point at which the tip of the attachment
is located when the upper turning body is oriented in a second direction that is different
from the first direction. The area setting part sets an area between the first straight
line and the second straight line in the plan view as the work area.
Brief Description of Drawings
[0007]
FIG. 1 is a side view of a work machine according to an embodiment.
FIG. 2 is a circuit diagram showing a plurality of components of a work area setting
system according to the embodiment.
FIG. 3 is a plan view of the work machine, showing a work area to be set for the work
machine when a first point and a second point are located on the same circle.
FIG. 4 is a plan view of the work machine, showing a first example of a work area
to be set when the first point and the second point are not on the same circle.
FIG. 5 is a plan view of the work machine, showing a second example of a work area
to be set when the first point and the second point are not on the same circle.
FIG. 6 is a plan view of a work machine according to a comparative example, showing
a rectangular work area that is set for the work machine.
Detailed Description
[0008] Below will be described a preferred embodiment of the present invention with reference
to the drawings.
[0009] According to the above embodiment, a work area of the work machine 20 shown in FIG.
1 is set by a work area setting system 1 shown in FIG. 2. FIG. 1 is a side view of
the work machine 20.
[0010] The work machine 20 according to the embodiment is a hydraulic excavator, including
a machine body 25, an attachment 30, and a work driving device 40. The attachment
30 makes a work motion.
[0011] The machine body 25 includes a lower traveling body 21 and an upper turning body
22. The lower traveling body 21 is a part that makes a traveling motion, for example,
including a pair of crawlers. The upper turning body 22 is mounted on the lower traveling
body 21 capably of turning around a vertical turning center axis through the turning
driving device 24. The turning driving device 24 is a device that turns the upper
turning body 22 with respect to the lower traveling body 21, for example, including
a hydraulic motor. The upper turning body 22 includes a cab (operation room) 23, which
is included in the front part of the upper turning body 22.
[0012] The attachment 30 is attached to the upper turning body 22 capably of rotational
movement in a direction along a motion surface that is a vertically extending plane,
namely, a vertical surface, the work motion including the rotational movement. The
attachment 30 includes a boom 31, an arm 32, and a bucket 33. The boom 31 is attached
to the upper turning body 22 capably of vertically rotational movement along the motion
surface with respect to the upper turning body 22. The arm 32 is attached to the boom
31 capably of vertically rotational movement along the motion surface with respect
to the boom 31. The bucket 33 is attached to the arm 32 capably of rotational movement
along the motion surface with respect to the arm 32. The bucket 33 is a tip attachment
to form a tip part of the attachment 30, being a part that makes the work motion on
earth and sand as a work target. The tip of the bucket 33, thus, corresponds to the
tip of the attachment 30. The work motion includes, for example, an excavation motion,
a leveling motion, and a scoop motion. The work object is not limited to earth and
sand but allowed to be also, for example, a stone or waste (such as industrial waste).
The tip attachment is not limited to the bucket 33 but allowed to be, for example,
a grapple or a lifting magnet.
[0013] The work driving device 40 hydraulically causes each of the boom 31, the arm 32,
and the bucket 33 to make rotational movement. The work driving device 40 includes
a plurality of hydraulic cylinders, namely, a boom cylinder 41, an arm cylinder 42,
and a bucket cylinder 43, each of which is capable of making expansion and contraction
motions.
[0014] The boom cylinder 41 makes the expansion and contraction motions to rotationally
move the boom 31 with respect to the upper turning body 22. The boom cylinder 41 has
a proximal end and a distal end opposite to the proximal end. The proximal end is
rotatably coupled to the upper turning body 22. The distal end is rotatably coupled
to the boom 31.
[0015] The arm cylinder 42 makes the expansion and contraction motions to rotationally move
the arm 32 with respect to the boom 31. The arm cylinder 42 has a proximal end and
a distal end opposite to the proximal end. The proximal end is rotatably coupled to
the boom 31. The distal end is rotatably coupled to the arm 32.
[0016] The bucket cylinder 43 makes the expansion and contraction motions to rotationally
move the bucket 33 with respect to the arm 32. The bucket cylinder 43 has a proximal
end and a distal end opposite to the proximal end. The proximal end is rotatably attached
to the arm 32. The distal end is rotatably attached to a link member 34, which is
rotatably attached to the bucket 33.
[0017] The work machine 20 further includes a turning angle detector 52 and a posture detector
60.
[0018] The turning angle detector 52 detects the turning angle of the upper turning body
22 with respect to the lower traveling body 21. The turning angle detector 52 is,
for example, an encoder, a resolver, or a gyro sensor. In the present embodiment,
the turning angle of the upper turning body 22 with the frontward direction of the
upper turning body 22 coincident with the frontward direction of the lower traveling
body 21 is 0°.
[0019] The posture detector 60 detects the posture of the attachment 30. The posture detector
60 according to the embodiment includes a boom inclination angle sensor 61, an arm
inclination angle sensor 62, and a bucket inclination angle sensor 63.
[0020] The boom inclination angle sensor 61 is attached to the boom 31 to detect the posture
of the boom 31. The boom inclination angle sensor 61 is a sensor that acquires an
inclination angle of the boom 31 with respect to a horizontal line, for example, being
an inclination sensor, an acceleration sensor, a rotation angle sensor that detects
a rotation angle of a boom foot pin in a proximal end of the boom 31, or a stroke
sensor that detects a stroke of the boom cylinder 41.
[0021] The arm inclination angle sensor 62 is attached to the arm 32 to detect the posture
of the arm 32. The arm inclination angle sensor 62 is a sensor that acquires an inclination
angle of the arm 32 with respect to a horizontal line, for example, being an inclination
sensor, an acceleration sensor, a rotation angle sensor that detects a rotation angle
of an arm connection pin at a proximal end of the arm 32, or a stroke sensor that
detects a stroke of the arm cylinder 42.
[0022] The bucket inclination angle sensor 63 is attached to the link member 34 to detect
the posture of the bucket 33. The bucket inclination angle sensor 63 is a sensor that
acquires an inclination angle of the bucket 33 with respect to a horizontal line,
for example, being an inclination sensor, an acceleration sensor, a rotation angle
sensor that detects a rotation angle of a bucket connection pin in a proximal end
of the bucket 33, or a stroke sensor that detects a stroke of the bucket cylinder
43.
[0023] FIG. 2 is a circuit diagram showing a plurality of components of the work area setting
system 1. The plurality of components include a controller 11 and a storage device
13.
[0024] To the controller 11 is input turning angle information, which is information on
the turning angle (posture) of the upper turning body 22 with respect to the lower
traveling body 21 and is acquired by the turning angle detector 52. To the controller
11 is input boom posture information, which is information on the posture of the boom
31 and is acquired by the boom inclination angle sensor 61. To the controller 11 is
input arm posture information, which is information on the posture of the arm 32 and
is acquired by the arm inclination angle sensor 62. To the controller 11 is input
bucket posture information, which is information on the posture of the bucket 33 and
is acquired by the bucket inclination angle sensor 63.
[0025] For the automatic operation of the work machine 20, the controller 11 automatically
controls the motions of the work machine 20. Specifically, the controller 11 controls
the motions of the upper turning body 22 and the attachment 30 so as to make the upper
turning body 22 and the attachment 30 perform repeated work. More specifically, the
controller 11 automatically controls the turning drive of the upper turning body 22
by the turning driving device 24 and the drive of the attachment 30 by the work driving
device 40 based on the information acquired by the turning angle detector 52 and the
posture detector 60. In the present embodiment, the repeated work is work of excavating
earth and sand and discharging it.
[0026] The storage device 13 stores information necessary for the automatic control. The
information includes respective coordinates of the first point PA and the second point
PB which are described later.
[0027] The controller 11 can serve as a first straight line setting part, which sets a first
straight line L1 shown in FIG. 3. FIG. 3 is a plan view of the work machine 20. In
a plan view in which the work machine 20 is viewed from above, the first straight
line L1 is a straight line parallel to the motion surface, that is, a straight line
parallel to the longitudinal direction of the attachment 30, passing through a first
point PA at which the tip of the bucket 33 is located, when the upper turning body
22 is oriented in a first direction, which is a right oblique direction in the example
shown in FIG. 3.
[0028] The controller 11 can also serve as a second straight line setting part, which sets
a second straight line L2 shown in FIG. 3. In the plan view, the second straight line
L2 is a straight line parallel to the motion surface, that is, a straight line parallel
to the longitudinal direction of the attachment 30, passing through a second point
PB at which the tip of the bucket 33 is located, when the upper turning body 22 is
oriented in a second direction different from the first direction, the second direction
being a left oblique direction in the example shown in FIG. 3.
[0029] Respective positions of the first and second straight lines L1 and L2, each of which
is a straight line parallel to the motion surface, with respect to the width direction
of the attachment 30 is not particularly limited. The width direction of the attachment
30 is a direction orthogonal to the motion surface, that is, a direction orthogonal
to each of the longitudinal direction and the vertical direction of the attachment
30. Specifically, as to the width direction, each of the first and second straight
lines L1 and L2 may be either a straight line passing through the widthwise center
of the attachment 30, or a straight line passing through the end in the width direction,
that is, a straight line along the side surface of the attachment 30.
[0030] The controller 11 can also serve as a coordinate calculation part. Specifically,
the controller 11 calculates a plurality of coordinates of the first point PA for
setting the first straight line L1 and calculates a plurality of coordinates of the
second point PB for setting the second straight line L2. In detail, the controller
11 obtains respective R-coordinates, Z-coordinates and θ-coordinates of the first
point PA and the second point PB. The R-coordinate is the coordinate in the front-rear
direction of the upper turning body 22, that is, the coordinate in the turning radial
direction of the upper turning body 22, and the Z-coordinate is the coordinate in
the vertical direction of the lower traveling body 21, and the θ-coordinate is the
coordinate in the turning direction of the upper turning body 22.
[0031] Respective coordinates in the front-rear direction of the first point PA and the
second point PB, namely, the R-coordinates, and respective coordinates in the vertical
direction, namely, the Z-coordinates, can be calculated, for example, from the posture
of the attachment 30. The posture of the attachment 30 can be obtained from the information
acquired by each of the boom inclination angle sensor 61, the arm inclination angle
sensor 62, and the bucket inclination angle sensor 63. The coordinates of the first
point PA and the second point PB in the turning direction, namely, the θ-coordinate,
can be calculated, for example, from a turning posture that is the posture of the
upper turning body 22 with respect to the lower traveling body 21. The turning posture
can be obtained from the information acquired by the turning angle detector 52.
[0032] The coordinates of the first point PA and the coordinates of the second point PB
using the upper turning body 22 as a reference can be calculated by a simple calculation,
for example, compared with the calculation of the position information by use of coordinates
based on a work site.
[0033] In the work site illustrated in FIG. 3, there is an earth-and-sand pile 70. The earth-and-sand
pile 70 is laid between the first point PA and the second point PB and frontward of
the upper turning body 22. In other words, the first point PA and the second point
PB are set so as to locate the earth-and-sand pile 70 therebetween.
[0034] In the present embodiment, the earth and sand of the earth-and-sand pile 70 can be
excavated by moving the attachment 30 along the motion surface at the turning angle
at which the tip of the bucket 33 is located at the first point PA. Similarly, the
earth and sand of the earth-and-sand pile 70 can be excavated by moving the attachment
30 along the motion surface at the turning angle at which the tip of the bucket 33
is located at the second point PB.
[0035] Each of the first point PA and the second point PB, alternatively, may be a position
greatly deviated from the earth-and-sand pile 70. The first and second points PA and
PB, thus, are not limited to excavation allowing positions, which are respective positions
at which the earth and sand of the earth-and-sand pile 70 can be excavated by moving
the attachment 30 at respective turning angles at which the tip of the bucket 33 is
located at the first and second points PA and PB.
[0036] The controller 11 can also serve as an area setting part that sets a work area 80
for the work machine 20. Specifically, the controller 11 sets an area between the
first straight line L1 and the second straight line L2 in the plan view as the work
area 80.
[0037] In the present embodiment, upon the setting of the first straight line L1 and the
second straight line L2, an excavation motion is actually made. The excavation motion
is not a special motion only for purpose of setting the work area 80 but serves also
as a motion for excavation work. This eliminates the necessity for making the work
machine 20 perform a special motion for setting the work area 80. Besides, special
calculation is not required for determining a specific graphic, for example, a rectangle,
in order to set the work area 80. This allows the work area 80 to be easily set.
[0038] The setting of the first and second points PA and PB for determining the first and
second straight lines L1 and L2 is not limited to one performed by an actual excavation
motion. For example, the first point PA and the second point PB may be taught by teaching
or the like. Alternatively, the first point PA and the second point PB may be set
either based on an image captured by a camera installed on or around the work machine
20 or by the input of a numerical value by an operator or the like.
[0039] Respective parallels of the first straight line L1 and the second straight line L2,
each of which is the boundary of the work area 80, to the motion surface of the attachment
30 allow the tip of the bucket 33 to be moved along the boundary of the work area
80 without the turn of the upper turning body 22. This reduces the necessity of making
the work machine 20 perform a complicated motion such as a motion of excavation or
earth removal with turning the upper turning body 22 in order to prevent the tip of
the bucket 33 from protruding beyond the work area 80. Besides, the allowability of
moving the tip of the bucket 33 along the boundary of the work area 80 with no requirement
for the turn of the upper turning body 22 reduces work left undone (e.g., earth left
unexcavated) in the work area 80.
[0040] In the example shown in FIG. 3, the first point PA and the second point PB are located
on the same circle Cc centered on a turning center axis Xs, which is the turning axis
of the upper turning body 22 with respect to the lower traveling body 21. In this
case, the controller 11 as the area setting part sets, in the plan view, an arc 81
interconnecting the first point PA and the second point PB along the same circle Cc
as an outer boundary of the work area 80 with respect to the turning radius direction
of the upper turning body 22.
[0041] The height of the first point PA and the height of the second point PB do not have
to be coincident with each other. The arc 81 interconnects the first point PA and
the second point PB smoothly in a side view in which the work machine 20 is viewed
from the side.
[0042] Setting the arc 81 as the boundary of the work area 80 provides the following effects.
In the case of performing repeated work with the turn of the upper turning body 22
while keeping the tip of the bucket 33 located most frontward with respect to the
front-rear direction, i.e., most outward with respect to the turning radial direction,
the work can be performed along the outer boundary of the work area 80. This eliminates
the need for a complicated calculation for revising the position of the tip of the
bucket 33 with the progress of the repeated work. Besides, the work can be restrained
from being left undone, for example, soil can be restrained from being left unexcavated,
in an outer section of the work area 80.
[0043] On the other hand, in the case where the first point PA and the second point PB are
not located on the same circle centered on the turning center axis, specifically,
as illustrated in FIG. 4, in the case where the first point PA is located on a first
circle Ca centered on the turning center axis whereas the second point PB is located
on a second circle Cb centered on the turning center axis, the first circle Ca and
the second circle Cb having different radii, the controller 11 as the area setting
part sets an arc-shaped curve 82 that smoothly interconnects the first point PA and
the second point PB in the plan view in which the work machine 20 is viewed from above
as the outer boundary of the work area 80 with respect to the turning radial direction.
In FIG. 4, the radius Ra of the circle passing through the first point PA is larger
than the radius Rb of the circle passing through the second point PB.
[0044] Also in the example shown in FIG. 4, the height of the first point PA and the height
of the second point PB do not have to be coincident with each other. The arc-shaped
curve 82 interconnects the first point PA and the second point PB smoothly in the
side view in which the work machine 20 is viewed from the side.
[0045] The arc-shaped curve 82 is set, for example, as follows. As shown in FIG. 4, in the
case where the length of the attachment 30 with the tip of the bucket 33 located at
the second point PB, namely, the radius (turning radius) Rb of the second circle Cb,
is smaller by ΔR than the length of the attachment 30 with the tip of the bucket 33
located at the first point PA, namely, the radius (turning radius) Ra of the first
circle Ca, in summary, in the case where Rb = Ra - ΔR, and where the turning angle
of the upper turning body 22 from the first point PA to the second point PB is an
angle θmax, the position R of the tip of the bucket 33 with respect to the front-rear
direction when the upper turning body 22 has been turned from the first point PA by
an angle θ is set so that R = R + θ/θmax × (-ΔR). The curve 82 that smoothly interconnects
the first point PA and the second point PB is thereby set.
[0046] Setting the curve 82 as the outer boundary of the work area 80 with respect to the
turning radial direction can smooth the movement of the tip of the bucket 33 in the
front-rear direction accompanying the turn of the upper turning body 22 in the repeated
work that is performed while changing the position of the tip of the bucket 33 in
the turning direction by the turn of the upper turning body 22, thereby reducing the
sense of incongruity to be imparted to a worker.
[0047] In the case where the first point PA and the second point PB are not on the same
circumference with the turning center axis as the center as described above, that
is, the case where the radius Ra of the first circle Ca on which the first point PA
is located is different from the radius Rb of the second circle Cb on which the second
point PB is located, the controller 11 may set the outer boundary of the work area
80 as shown in FIG. 5.
[0048] In FIG. 5, the controller 11 initially sets a third point PC located between the
first point PA and the second point PB. The third point PC may be set either by actual
performance of the motion of the attachment 30 corresponding to excavation work or
by teaching or the like. The third point PC may be located at either a just intermediate
position between the first point PA and the second point PB in the turning direction
of the upper turning body 22 or a position closer to the first point PA or the second
point PB than the just intermediate position.
[0049] Next, based on the position of the first point PA, the controller 11 sets a first-point-side
portion of the boundary of the work area 80, which is a portion closer to the first
point PA than the third point PC, in the plan view. Specifically, the controller 11
sets the first-point-side portion to the arc that passes through the first point PA
and has a radius equal to the radius Ra of the first circle Ca passing through the
first point PA, that is, the turning radius corresponding to the first point PA.
[0050] On the other hand, in the plan view, the controller 11 sets a second-point-side portion
of the boundary of the work area 80, which is a portion closer to the second point
PB than the third point PC, based on the position of the second point PB. Specifically,
the controller 11 sets the second-point-side portion to the arc that passes through
the second point PB and has a radius equal to the radius Rb of the second circle Cb
passing through the second point PB, that is, the turning radius corresponding to
the second point PB.
[0051] Also in this example, the height of the first point PA and the height of the second
point PB do not have to be coincident with each other. Out of the boundary of the
work area 80, the controller 11 may set the height of the first-point-side portion
based on the height of the first point PA while sets the height of the second-point-side
portion based on the height of the second point PB.
[0052] Such setting of the boundary of the work area 80 allows an appropriate work area
80 to be set in accordance with respective situations around the work machine 20 corresponding
to the first-point-side portion and the second-point-side portion, even if the situations
are different from each other.
[0053] For example, in the case of presence of an obstacle 90 such as a column near the
second straight line L2 passing through the second point PB as shown in FIG. 5, setting
the second point PB so as to avoid the obstacle 90 involves a difference between the
radius Ra of the first circle Ca passing through the first point PA and the radius
Rb of the second circle Cb passing through the second point PB. In such a case, setting
the outer boundary of the work area 80 based on the position of the second point PB
makes it possible to make the work machine 20 perform repeated work with avoidance
of the obstacle 90.
[0054] FIG. 6 shows a comparative example for explaining the advantage of the work area
80 shown in FIGS. 3 to 5, in which example a rectangular work area 85 is set around
the earth-and-sand pile 75. Among four vertices Pa, Pb, Pc, and Pd that define the
work area 85, respective positions of the pair of vertices Pa and Pc that are diagonal
to each other are taught to the controller by actually positioning the tip of the
bucket 33 in each of the vertices Pa, Pc. The controller determines the remaining
two vertices Pb, Pd by calculation based on the pair of vertices Pa, Pc. The work
area 85 is thus determined.
[0055] Such setting requires making the work machine perform a special motion that is quite
different from normal excavation motion or loading motion, being complicated. The
calculation for determining the rectangular work area 85 based on the pair of vertices
Pa and Pc is also complicated.
[0056] In contrast, the work area setting system 1 according to the embodiment can set the
work area 80 during the flow of the repeated work by use of the first straight line
L1 that is set when the upper turning body 22 is oriented in the first direction and
the second straight line L2 that is set when the upper turning body 22 is oriented
in the second direction. This eliminates the necessity for making the work machine
20 perform a special motion for only the purpose of setting the work area 80 and the
necessity for performing a complicated calculation for setting the work area 80. These
allow the work area 80 to be easily set.
[0057] The parallel of each of the first straight line L1 and the second straight line L2,
which are boundaries of the work area 80, to the motion surface of the attachment
30 enables the tip of the bucket 33 to be moved along the boundary of the work area
80 even without the turn of the upper turning body 22. This can reduce the necessity
for making the work machine 20 perform complicated motions such as excavation and
earth removal while turning the upper turning body 22 in order to prevent the tip
of the bucket 33 from protruding beyond the work area 80. Besides, the tip of the
bucket 33 can be moved along the boundary of the work area 80 without the turn of
the upper turning body 22, which reduces the work left undone in the work area 80,
for example, reduces the soil left unexcavated.
[0058] The embodiment of the present invention having been described above is merely an
illustrated example, not intended to limit the present invention thereto, allowing
a specific configuration or the like to be modified as appropriate. The actions and
effects described about the embodiments of the invention are merely listing most suitable
actions and effects provided by the present invention, and the actions and effects
of the invention are not limited to those described in the embodiments of the present
invention.
[0059] As has been described, there is provided a work area setting system that allows a
work area of a work machine to be easily set.
[0060] Provided is a work area setting system for setting a work area in which a work machine
makes a work motion. The work machine includes a lower traveling body, an upper turning
body mounted on an upper part of the lower traveling body capably of turning around
a vertical turning center axis, and an attachment attached to the upper turning body
capably of rotational movement in a direction along a motion surface that is a plane
extending vertically to make the work motion. The work area setting system includes
a first straight line setting part, a second straight line setting part, and an area
setting part. The first straight line setting part sets a first straight line, which
is a straight line parallel to the motion surface in a plan view in which the work
machine is viewed from above and passes through a first point at which a tip of the
attachment is located when the upper turning body is oriented in a first direction.
The second straight line setting part sets a second straight line, which is a straight
line parallel to the motion surface in the plan view and passes through a second point
at which a tip of the attachment is located when the upper turning body is oriented
in a second direction that is different from the first direction. The area setting
part sets an area between the first straight line and the second straight line in
the plan view as the work area.
[0061] The area setting system allows the work area to be easily set by use of the first
straight line that is set when the upper turning body is oriented in the first direction
and the second straight line that is set when the upper turning body is oriented in
the second direction, during the flow of the repeated work. Specifically, the setting
of the work area eliminates the necessity for making the work machine perform a special
motion for only the purpose of setting the work area and the need for a special calculation.
[0062] The parallel of each of the first straight line and the second straight line, each
of which is the boundary of the work area, to the motion surface of the attachment
enables the tip of the attachment to be moved along the boundary of the work area
while not requiring any turn of the upper turning body. This can reduce the necessity
for making the work machine perform a complicated motion such as a motion of performing
excavation or earth removal while turning the upper turning body so as to prevent
the tip of the attachment from protruding beyond the work area. Besides, the ability
to move the tip of the attachment along the first and second straight lines, each
of which is the boundary of the work area, without the turn of the upper turning body
can reduce work left undone in the work area, for example, the soil left unexcavated.
[0063] Specifically, for the case where both the first point and the second point are located
on the same circle centered on the turning center axis in the plan view, the area
setting part is preferably configured to set an arc that interconnects the first point
and the second point along the same circle as an outer boundary of the work area with
respect to the turning radial direction of the upper turning body. This allows the
work involving movement of the tip of the attachment along the outer boundary of the
work area to be easily performed by a simple motion of only turning the upper turning
body without changing the position of the tip of the attachment in the turning radial
direction, that is, the front-rear direction of the attachment. Specifically, eliminated
is the need for a complicated calculation for revising the position of the tip of
the attachment in the front-rear direction (turning radial direction) with the progress
of the repeated work. Besides, can be reduced work left undone in the work area, for
example, the soil left unexcavated, near an outer section of the work area.
[0064] In the case where the first point and the second point are not in the same circle
centered on the turning center axis in the plan view, specifically, the case where
the first point is located on a first circle centered on the turning center axis whereas
the second point is located on a second circle centered on the turning center axis,
the first circle having a radius different from a radius of the second circle, the
area setting part may set an arc-shaped curve that interconnects the first point and
the second point as an outer boundary of the work area with respect to the turning
radius direction. This can smooth the variation in the position of the tip of the
attachment with respect to the turning radial direction in association with the turn
of the upper turning body to thereby reduce the sense of incongruity to be imparted
to a worker.
[0065] In the above case, the area setting part may be configured to set a third point between
the first point and the second point and configured to set a first-point-side portion,
which is a portion closer to the first point than the third point out of the outer
boundary of the work area, based on the position of the first point and set a second-point-side
portion, which is a portion closer to the second point than the third point out of
the outer boundary of the work area, based on the position of the second point. This
enables different outer boundaries to be set on both sides of the third point, respectively,
allowing an appropriate work area to be set in accordance with respective situations
around the work machine corresponding to the first-point-side portion and the second-point-side
portion, even if the situations are different from each other.
[0066] Preferably, the work area setting system further includes a coordinate calculation
part that calculates a plurality of coordinates for each of the first point and the
second point, the plurality of coordinates including coordinates in a front-rear direction
of the upper turning body, coordinates in a vertical direction of the lower traveling
body, and coordinates in a turning direction of the upper turning body. The coordinates
in the front-rear direction of the upper turning body 22 and the coordinates in the
vertical direction of the lower traveling body can be calculated, for example, from
the posture of the attachment, and the coordinates in the turning direction of the
upper turning body can be calculated, for example, from the posture of the upper turning
body 22 with respect to the lower traveling body 21. Hence, the plurality of coordinates
of the first point and the second point can be calculated by a simpler calculation
than, for example, the calculation of position information using the coordinates based
on the work site.