[0001]The present invention relates to a working vehicle, for example.
[BACKGROUND ART]
[0002] Conventionally, an agricultural working machine such as disclosed in Patent
Document 1 has been known. The agricultural working machine in Patent Document 1 has a
traveling machine body that travels along a set traveling line parallel to a traveling reference
line, either one of manual traveling by using manual steering and automatic traveling by using
automatic steering being determined as the traveling of the traveling machine body, and a
changeover switch switchable between a manual traveling setting state and an automatic
traveling setting state. Also, the agricultural working machine has a right instruction button
and a left instruction button such that, during traveling thereof along a ridge, a start point of
the traveling reference line is set by pressing the right instruction button, and an end point of
the traveling reference line is set by pressing the left instruction button. That is, the traveling
reference line is set before using automatic steering.
[RELATED ART DOCUMENTS]
[PATENT DOCUMENTS]
[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2017-123803
[DISCLOSURE OF THE INVENTION]
[PROBLEMS TO BE SOLVED BY THE INVENTION]
[0004] In the agricultural working machine of Patent Document 1, by switching of the
changeover switch from the manual traveling setting state to the automatic traveling setting
state, the automatic traveling can be easily performed. The set traveling line in Patent
Document 1 has a constant interval, which cannot be arbitrarily changed.
Thus, in view of the above-described problem, an object of the present invention is to
provide a working vehicle allowing automatic steering to be easily performed in
correspondence to the working situation.
2

[MEANS OF SOLVING THE PROBLEMS]
[0005] Technical means of the present invention to solve this technical problem have the
following points as characteristics.
A working vehicle includes a vehicle body to travel either by manual steering with a steering wheel or by automatic steering with the steering wheel, a reference registering unit which registers a traveling reference line based on a position of the vehicle body caused to travel by the manual steering, a traveling line setting unit configured or programmed to set, based on the traveling reference line, a plurality of scheduled traveling lines for traveling using the automatic steering, and an automatic steering control unit to control the automatic steering based on the scheduled traveling lines. The traveling line setting unit is configured or programmed to change an adjacency width between the scheduled traveling lines adjoining each other among the plurality of scheduled traveling lines.
[0006] The working vehicle further includes a changing operation member operable to
issue therefrom an instruction for changing of the adjacency width. The traveling line
setting unit is configured or programmed to change the adjacency width when the instruction for the changing is issued from the changing operation member.
The working vehicle further includes a calculation unit to calculate a work count that is a count of times of performing a ground work. The traveling line setting unit is configured or programmed to change the adjacency width based on a predetermined count reached by the work count calculated by the calculation unit.
[0007] The working vehicle further includes a display device having a reference input
portion to input a reference adjacency width, which is a reference width between the scheduled traveling lines adjoining each other, and a variation input portion to input a variation adjacency width. The traveling line setting unit is configured or programmed to change the adjacency width based on the reference adjacency width and the variation adjacency width.
The working vehicle further includes a display device having a reference input
portion to input a reference adjacency width, which is a reference width between the
3

scheduled traveling lines adjoining each other, and a variation input portion to input a
variation adjacency width. The traveling line setting unit is configured or programmed to
change the adjacency width to a value obtained by adding the variation adjacency width to the
reference adjacency width when the instruction for the changing is issued from the changing
operation member, and set the reference adjacency width as the adjacency width when the
instruction for the changing is not issued from the changing operation member.
[0008] The working vehicle further includes a reference input portion to input a reference
adjacency width, which is a reference width between the scheduled traveling lines adjoining
each other, and a variation input portion to input a variation adjacency width. The traveling
line setting unit is configured or programmed to change the adjacency width to a value
obtained by adding the variation adjacency width to the reference adjacency width when the
work count calculated by the calculation unit reaches a predetermined count, and set the
reference adjacency width as the adjacency width when the work count does not reach the
predetermined count.
[0009] The working vehicle further includes a first assist control unit configured or
programmed so that, when the adjacency width is unchanged, the first assist control unit
automatically guides, after the automatic steering is terminated, the vehicle body to the
scheduled traveling lines with the unchanged adjacency width, and a second assist control unit
configured or programmed so that, when the adjacency width is changed, the second assist
control unit automatically guides, after the automatic steering is terminated, the vehicle body
to the scheduled traveling lines with the changed adjacency width.
The working vehicle further includes a display device to display information about
the vehicle body, and a display control unit to cause the display device to display the
scheduled traveling line on which the vehicle body travels and a next-scheduled traveling line
adjoining the scheduled traveling line. When an adjacency width between scheduled
traveling lines adjoining each other is changed, the display control unit causes the display
device to display the next-scheduled traveling line to be scheduled after the changing.
[EFFECTS OF THE INVENTION]
4

[0010] According to the present invention, automatic steering in correspondence to the working situation can be easily performed. [BRIEF DESCRIPTION OF THE DRAWINGS]
[0011]
FIG. 1 is a view depicting a configuration of a tractor and depicting a control block diagram.
FIG. 2 is a descriptive diagram for describing automatic steering.
FIG. 3 is a descriptive diagram for describing the operation of automatic steering.
FIG. 4 is a diagram depicting one example of an operation screen M1, a guidance screen M2, and a setting screen M3.
FIG. 5 is a diagram depicting one example of a turn guidance screen M2a and an interrow guidance screen M2b.
FIG. 6A is a schematic diagram briefly depicting turn traveling J1 from straight-forward traveling.
FIG. 6B is a diagram depicting a state in which an azimuth (vehicle-body azimuth) F1 of a forwarding direction and an azimuth (line azimuth) F2 of a traveling reference line L1 are different.
FIG. 7 A is a diagram depicting one example of the turn guidance screen M2a when an azimuth difference AF3 indicates matching.
FIG. 7B is a diagram depicting one example of the turn guidance screen M2a when the azimuth difference AF3 indicates a difference.
FIG. 7C is a diagram depicting one example of the turn guidance screen M2a when the azimuth difference AF3 is within a threshold value after turning.
FIG. 8 is a diagram depicting one example of a home setting screen M3a.
FIG. 9 is a diagram a state in which switching is made from the home setting screen M3a to a detail setting screen M3b.
FIG. 10A is a diagram depicting one example of a detail setting screen M3b1.
FIG. 10B is a diagram depicting one example of a detail setting screen M3b2.
5

FIG. 10C is a diagram depicting one example of a detail setting screen M3b3.
FIG. 11 is a diagram depicting an operation flow by operation on an input button.
FIG. 12 is a diagram depicting a traveling path of the tractor with a start point and an end point of automatic steering being set.
FIG. 13 is a diagram depicting a flow of changing an adjacency width L10 by a changing operation member.
FIG. 14 is a diagram depicting a flow of automatically changing the adjacency width L10.
FIG. 15A is a diagram depicting an interrow assist when the adjacency width L10 is not changed.
FIG. 15B is a diagram depicting an interrow assist when the adjacency width L10 is changed.
FIG. 16 is a diagram depicting operation of a notification device.
FIG. 17 is a diagram depicting the periphery of the operator's seat.
FIG. 18 is a general view of the tractor. [BEST MODE FOR CARRYING OUT THE INVENTION]
[0012] In the following, one embodiment of the present invention is described based on
the drawings.
FIG. 18 is a side view depicting one embodiment of a working vehicle 1, and FIG. 18
is a plan view depicting one embodiment of the working vehicle 1. In the present
embodiment, the working vehicle 1 is a tractor. However, the working vehicle 1 is not
limited to a tractor but may be agricultural machine (agricultural vehicle) such as a combine
or a transplanter or may be construction machine (construction vehicle) or the like such as a
loader.
[0013] FIG. 18 is a side view depicting the working vehicle 1. By using FIG. 18 and so
forth, the tractor (working vehicle) 1 is described. In the following, description is made by
taking a front side of an operator sitting on an operator's seat 10 of the tractor (working
vehicle) 1 as forward, a rear side of the operator as rearward, a left side of the operator as
6

leftward, and a right side of the operator as rightward. Also, description is made by taking a
horizontal direction, which is a direction orthogonal to a fore-and-aft direction of the working
vehicle 1, as a vehicle body width direction.
[0014] As depicted in FIG. 18, the tractor 1 includes a vehicle body 3, a prime mover 4, a
transmission 5. The vehicle body 3 has a traveling device 7 and is capable of traveling.
The traveling device 7 is a device having front wheels 7F and rear wheels 7R. The front
wheels 7F may be of a tire type or a crawler type. Also, the rear wheels 7R may be of a tire
type or a crawler type.
The prime mover 4 is a diesel engine, an electric motor, or the like. In this
embodiment, the prime mover 4 is a diesel engine. The transmission 5 is capable of
switching the driving force of the traveling device 7 by speed shifting, and is also capable of
switching between forward traveling and rearward traveling of the traveling device 7. The
operator's seat 10 is provided in the vehicle body 3.
[0015] Also, a coupling portion 8 is provided at a rear portion of the vehicle body 3. A
three-point linkage mechanism or the like serves as the coupling portion 8. The working
device 2 is attachable to and detachable from the coupling portion 8. By coupling the
working device 2 to the coupling portion 8, the working device 2 can be towed by the vehicle
body 3. The working device 2 is a tiller for tilling, a fertilizer spreader for spreading
fertilizer, an agricultural chemical spreader for spreading agricultural chemicals, a harvester
for harvesting, a mower for mowing grass or the like, a ridger for ridging, or the like, and is a
device for performing a work (ground work) on a ground such as an agricultural field.
[0016] As depicted in FIG. 1, the transmission 5 includes a main shaft (propeller shaft) 5a,
a main speed shifting unit 5b, a sub-speed shifting unit 5c, a shuttle unit 5d, a PTO power
transmission unit 5e, and a front speed shifting unit 5f. The propeller shaft 5a is rotatably
supported by a housing case (transmission case), and power from the crank shaft of the prime
mover 4 is transmitted to the propeller shaft 5a. The main speed shifting unit 5b has a
plurality of gears and a shifter for changing connection of the gears. By changing the
connection (engagement) of the plurality of gears as appropriate with the shifter, the main
7

speed shifting unit 5b changes and outputs rotation inputted from the propeller shaft 5a
(changes speed).
[0017] Similar to the main speed shifting unit 5b, the sub-speed shifting unit 5c has a
plurality of gears and a shifter for changing connection of the gears. By changing the
connection (engagement) of the plurality of gears as appropriate with the shifter, the
sub-speed shifting unit 5c changes rotation speed and outputs the speed-changed rotation
inputted from the main speed shifting unit 5b.
The shuttle unit 5d has a shuttle shaft 12 and a forward-rearward traveling switching
unit 13. The power outputted from the sub-speed shifting unit 5c is transmitted to the shuttle
shaft via gears and the like. The forward-rearward traveling switching unit 13 includes, for
example, a hydraulic clutch or the like, which is clutched on and off to switch the rotating
direction of the shuttle shaft 12, that is, set whether forward traveling or rearward traveling of
the tractor 1. The shuttle shaft 12 is connected to a rear-wheel differential device 20R. The
rear-wheel differential device 20R rotatably supports a rear axles 21R to which the rear
wheels 7R are attached.
[0018] The PTO power transmission unit 5e has a PTO propeller shaft 14 and a PTO
clutch 15. The PTO propeller shaft 14 is rotatably supported, and is capable of transmitting
power from the propeller shaft 5a. The PTO propeller shaft 14 is connected to a PTO shaft
16 via gears or the like. The PTO clutch 15 is, for example, a hydraulic clutch or the like,
which is configured to be engaged and disengaged to switch a transmission state between a
state of transmitting power of the propeller shaft 5a to the PTO propeller shaft 14 and a state
of not transmitting power of the propeller shaft 5a to the PTO propeller shaft 14.
[0019] The front speed shifting unit 5f has a first clutch 17 and a second clutch 18. The
first clutch 17 and the second clutch 18 are capable of transmitting power from the propeller
shaft 5a and power from the shuttle shaft 12 is transmitted via gears and a line shaft. Power
from the first clutch 17 and the second clutch 18 can be transmitted via a front line shaft 22 to
a front axle shaft 21F. Specifically, the front line shaft 22 is connected to a front-wheel
differential device 20F, and the front-wheel differential device 20F rotatably supports the front
8

axle shaft 21F to which the front wheels 7F are attached.
[0020] The first clutch 17 and the second clutch 18 are hydraulic clutches or the like. A
fluid passage connected to the first clutch 17 is connected to a first actuation valve 25 which
is supplied with hydraulic fluid delivered from a hydraulic pump 33. The first clutch 17 is
switched between a clutch-on state and a clutch-off state depending on the opening degree of
the first actuation valve 25. A fluid passage connected to the second clutch 18 is connected
to a second actuation valve 26. The second clutch 18 is switched between a clutch-on state
and a clutch-off state depending on the opening degree of the second actuation valve 26.
The first actuation valve 25 and the second actuation valve 26 are, for example, solenoid
two-position changeover valves having solenoids each of which is excited and unexcited to
switch the corresponding first or second actuation valve 25 or 26 between the clutch-on state
and the clutch-off state.
[0021] When the first clutch 17 is in the clutch-off state and the second clutch 18 is in the
clutch-on state, power of the shuttle shaft 12 is transmitted via the second clutch 18 to the
front wheels 7F. This makes a four-wheel drive (4WD) mode in which the front wheels 7F
and the rear wheels 7R are driven by the driving power, and the rotation speeds of the front
wheels 7F and the rear wheels 7R are substantially equal to each other (an equal-speed 4WD
state). On the other hand, when the first clutch 17 is in the clutch-on state and the second
clutch 18 is in the clutch-off state, the vehicle is set in a four-wheel drive mode in which the
rotation speed of the front wheels 7F becomes faster than the rotation speed of the rear wheels
7R (an acceleration 4WD state). Also, when the first clutch 17 and the second clutch 18 are
in the clutch-off state, power of the shuttle shaft 12 is not transmitted to the front wheels 7F,
and thus the vehicle is set in a two-wheel drive (2WD) mode in which only the rear wheels 7R
are driven by the driving power.
[0022] The tractor 1 includes a positioning device 40. The positioning device 40 is
capable of detecting its own position (positioning information including latitude and
longitude) with a satellite positioning system (positioning satellite) such as D-GPS, GPS,
GLONASS, HOKUTO, GALILEO, and MICHIBIKI. That is, the positioning device 40
9

receives a satellite signal transmitted from the positioning satellite (such as the position of the
positioning satellite, transmission time, and correction information), and detects the position
(for example, latitude and longitude) based on the satellite signal. The positioning device 40
has a receiver 41 and an inertial measurement unit (IMU: Inertial Measurement Unit) 42.
The receiver 41 is a device having an antenna or the like to receive satellite signals
transmitted from the positioning satellite, and is attached to the vehicle body 3 separately
from the inertial measurement unit 42. In this embodiment, the receiver 41 is disposed
above the roof of the cabin via a supporting member. Note that the attachment location of
the receiver 41 is not limited by the embodiment.
[0023] The inertial measurement unit 42 has an acceleration sensor to detect acceleration,
a gyro sensor to detect angular velocity, and so forth. The vehicle body 3 is provided, for
example, below the operator's seat 10 or the like. By the inertial measurement unit 42, the
roll angle, pitch angle, yaw angle, and so forth of the vehicle body 3 can be detected.
As depicted in FIG. 1, the tractor 1 includes a steering device 11. The steering
device 11 is a device capable of performing manual steering of the vehicle body 3 with
steering operation by the operator and automatic steering of the vehicle body 3 without
steering operation by the operator.
[0024] The steering device 11 has the steering wheel 30 and a steering shaft (rotation
shaft) 31 rotatably supporting the steering wheel 30. Also, the steering device 11 has an
assist mechanism (power steering device) 32. The assist mechanism 32 assists the rotation
of the steering shaft 31 (steering wheel 30) with hydraulic pressure or the like. The assist
mechanism 32 includes the hydraulic pump 33, a control valve 34 to which a hydraulic fluid
delivered from the hydraulic pump 33 is supplied, and a steering cylinder 35 which is actuated
by the control valve 34. The control valve 34 is, for example, a three-position changeover
valve that is switchable with the movement of a spool or the like, and is switched in
accordance with the steering direction (rotating direction) of the steering shaft 31. The
steering cylinder 35 is connected to an arm (knuckle arm) for changing the orientation of the
front wheels 7F.
10

[0025] Therefore, when the operator holds and operates the steering wheel 30 in one
direction or the other direction, the switching position and the opening degree of the control
valve 34 are switched in accordance with the rotating direction of the steering wheel 30 and,
with the steering cylinder 35 extending or contracting to left or right in accordance with the
switching position and the opening degree of the control valve 34, the steering direction of the
front wheels 7F can be changed. That is, in the vehicle body 3, the forwarding direction can
be changed to left or right by manual steering of the steering wheel 30.
[0026] As depicted in FIG. 2, to perform automatic steering, a traveling reference line L1
is first set. After the traveling reference line L1 is set, a scheduled traveling line L2 parallel
to the traveling reference line L1 is set, thereby allowing automatic steering to be performed.
In automatic steering, steering of the tractor 1 (vehicle body 3) in the forwarding direction is
automatically performed so that the vehicle-body position measured by the positioning device
40 matches the scheduled traveling line L2.
[0027] Specifically, before performing automatic steering, the tractor 1 (vehicle body 3)
is moved to a predetermined position in an agricultural field (S1), and the operator operates a
steering changeover switch (registration switch) 52 provided in the tractor 1 at a
predetermined position (S2). Accordingly, the vehicle-body position measured by the
positioning device 40 is set as a start point P10 of the traveling reference line L1 (S3).
Further, the tractor 1 (vehicle body 3) is moved from the start point P10 of the traveling
reference line L1 (S4), and the operator operates the steering changeover switch (registration
switch) 52 at a predetermined position (S5). Accordingly, the vehicle-body position
measured by the positioning device 40 is set as an end point P11 of the traveling reference
line L1 (S6). Therefore, a straight line connecting the start point P10 and the end point P11
is set as the traveling reference line L1.
[0028] After the traveling reference line L1 is set (after S6), for example, the tractor 1
(vehicle body 3) is moved to a location different from the location where the traveling
reference line L1 is set (S7), and the operator operates the steering changeover switch 52 (S8).
Accordingly, the scheduled traveling line L2 is set, which is a straight line parallel to the
11

traveling reference line L1 (S9). After the scheduled traveling line L2 is set, automatic
steering is started, and the forwarding direction of the tractor 1 (vehicle body 3) varies along
the scheduled traveling line L2. For example, the front wheels 7F are steered to right when
the current vehicle-body position is on the left side with respect to the scheduled traveling line
L2, and the front wheels 7F are steered to left when the current vehicle-body position is on the
right side with respect to the scheduled traveling line L2. Note that during automatic
steering, the traveling speed (vehicle speed) of the tractor 1 (vehicle body 3) can be changed
by the operator who manually changes the operation amount of an accelerator (accelerator
pedal, accelerator lever) 210 or changes the speed stage of the transmission 5 with a
speed-shift member (speed-shift lever, speed-shift switch) 211.
[0029] Also, after the automatic steering starts, the operator can terminate the automatic
steering by operating the steering changeover switch at any location. That is, the end point
of the scheduled traveling line L2 can be set by terminating the automatic steering with
operation of the steering changeover switch 52. That is, the length from the start point to the
end point of the scheduled traveling line L2 can be set longer or shorter than the traveling
reference line L1. In other words, the scheduled traveling line L2 is not associated with the
length of the traveling reference line L1, and the scheduled traveling line L2 allows traveling
to a distance longer than the length of the traveling reference line L1 during performing the
automatic steering.
[0030] As depicted in FIG. 1, the steering device 11 has an automatic steering mechanism
37. The automatic steering mechanism 37 is a mechanism for automatic steering of the
vehicle body 3 based on the position of the vehicle body 3 (vehicle-body position) detected by
the positioning device 40. The automatic steering mechanism 37 includes a steering motor
38 and a gear mechanism 39. The steering motor 38 is a motor capable of controlling the
rotating direction, rotation speed and rotation angle, and so forth based on the vehicle-body
position. The gear mechanism 39 includes a gear provided on the steering shaft 31 to rotate
with the steering shaft 31 and a gear provided on the rotation shaft of the steering motor 38 to
rotate with the rotation shaft. When the rotation shaft of the steering motor 38 rotates, the
12

steering shaft 31 automatically rotates (revolves) via the gear mechanism 39 to allow the front
wheels 7F to be steered to change their direction so that the vehicle-body position matches the
scheduled traveling line L2.
[0031] As depicted in FIG. 1, the tractor 1 includes a setting switch 51. The setting
switch 51 is a switch switchable to at least a setting mode in which setting is allowed to be
performed before starting automatic steering. In the setting mode before starting automatic
steering, various settings relating to the automatic steering, and, for example, a start point and
end point of the traveling reference line L1, and so forth can be performed.
The setting switch 51 can be turned on and off. The setting switch 51, when turned
on, outputs a signal indicating that the setting mode is enabled and the setting switch 51, when
turned off, outputs a signal indicating that the setting mode is disabled. Also, the setting
switch 51, when turned on, outputs, to the display device 45, a signal indicating that the
setting mode is enabled, and the setting switch 51, when turned off, outputs to the display
device 45 a signal indicating that the setting mode is disabled.
[0032] The tractor 1 includes the steering changeover switch 52. The steering
changeover switch 52 is a switch switchable between a state for start of automatic steering
and a state for termination of automatic steering. Specifically, the steering changeover
switch 52 is shiftable upward, downward, forward, and rearward from a neutral position. In
a state where the setting mode is enabled, the steering changeover switch 52, when shifted
downward from the neutral position, outputs a signal for start of automatic steering. In the
state where the setting mode is disabled, the steering changeover switch 52, when shifted
upward from the neutral position, outputs a signal for termination of automatic steering.
Also, in the state where the setting mode is enabled, the steering changeover switch 52, when
shifted rearward from the neutral position, outputs setting of the start point P10 of the
traveling reference line L1. In the state where the setting mode is enabled, the steering
changeover switch 52, when shifted forward from the neutral position, outputs setting of the
end point P11 of the traveling reference line L1. That is, the steering changeover switch 52
serves as a registration switch for setting a start position (start point P10) and an end position
13

(end point P11) of the traveling reference line L1 and a switch for selecting either start or termination of automatic switching.
[0033] As depicted in FIG. 1, the tractor 1 includes a plurality of controllers 60. The
plurality of controllers 60 are devices to perform control over a traveling system, control over a working system, calculation of the vehicle-body position, and so forth in the tractor 1. The plurality of controllers 60 are a first controller 60A, a second controller 60B, and a third controller 60C.
The first controller 60A receives a satellite signal (reception information) received by the receiver 41 and measurement information (acceleration and angular velocity) obtained by measurement by the inertial measurement device 42, and finds the vehicle-body position based on the received information and the measurement information.
[0034] Also, the first controller 60A has a reference registering unit 150. The reference
registering unit 150 is configured of an electric and electronic circuit provided in the first controller 60A, a program stored in a CPU or the like, or so forth. As described above, the reference registering unit 150 registers the traveling reference line L1, that is, sets the start point P10 and the end point P11. In a situation where the tractor 1 is caused to travel by manual steering while the setting mode is set, the reference registering unit 150 sets the vehicle-body position as the start point P10 of the traveling reference line L1 by operating the steering changeover switch 52 to a start-point setting side, and the reference registering unit 150 sets the vehicle-body position as the end point P11 of the traveling reference line L1 by operating the steering changeover switch 52 to an end-point setting side.
[0035] The second controller 60B has an automatic steering control unit 200. The
automatic steering control unit 200 is configured of an electric and electronic circuit provided in the second controller 60B, a program stored in a CPU or the like, or so forth. The automatic steering control unit 200 controls the steering motor 38 of the automatic steering mechanism 37 so that the vehicle body 3 travels along the scheduled traveling line L2.
As depicted in FIG. 3, when the steering changeover switch 52 is operated to an
automatic steering start side, the automatic steering control unit 200 causes automatic steering
14

of the tractor 1 (vehicle body 3) based on the scheduled traveling line L2 parallel to the traveling reference line L1. When a deviation between the vehicle-body position and the scheduled traveling line L2 is equal to or smaller than a threshold value, the automatic steering control unit 200 keeps the rotation angle of the rotation shaft of the steering motor 38. When the deviation (positional deviation) between the vehicle-body position and the scheduled traveling line L2 is equal to or larger than the threshold value and the tractor 1 is positioned on the left side with respect to the scheduled traveling line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the tractor 1 is steered rightward. That is, the automatic steering control unit 200 sets a steering angle in the right direction so that the positional deviation becomes zero. When the deviation between the vehicle-body position and the scheduled traveling line L2 is equal to or larger than the threshold value and the tractor 1 is positioned on the right side with respect to the scheduled traveling line L2, the automatic steering control unit 200 rotates the rotation shaft of the steering motor 38 so that the tractor 1 is steered leftward. That is, the automatic steering control unit 200 sets a steering angle in the left direction so that the positional deviation becomes zero.
[0036] In the above-described embodiment, the steering angle of the steering device 11 is changed based on the deviation between the vehicle-body position and the scheduled traveling line L2. Alternatively, when the azimuth of the scheduled traveling line L2 and an azimuth (vehicle-body azimuth) F1 of the tractor 1 (vehicle body 3) in the forwarding direction (traveling direction) are different, that is, when an angle 9g of the vehicle-body azimuth F1 with respect to the scheduled traveling line L2 is equal to or larger than a threshold value, the automatic steering control unit 200 may set a steering angle so that the angle 9g becomes zero (the vehicle-body azimuth F1 matches the azimuth of the scheduled traveling line L2). Also, the automatic steering control unit 200 may set a final steering angle in automatic steering based on the steering angle found based on the deviation (positional deviation) and a steering angle found based on the azimuth (azimuth deviation). Setting of the steering angle in
automatic steering in the above-described embodiment is one example and is not meant to be
15

restrictive. Note that the azimuth (vehicle-body azimuth) F1 of the vehicle body 3 can be
found by the positioning device 40.
[0037] Also, when the accelerator 210 is operated during automatic steering being
performed by the automatic steering control unit 200, the second controller 60B changes the
rotation speed of the prime mover 4 (prime mover rotation speed) in accordance with the
operation amount of the accelerator 210. Also, when the speed-shift member 211 is operated
during automatic steering being performed by the automatic steering control unit 200, the
second controller 60B changes the speed-shifting stage of the transmission 5.
[0038] The third controller 60C causes the coupling portion 8 to be lifted up and down in
accordance with the operation of an operating member provided on the periphery of the
operator's seat 10. Note that the first controller 60A, the second controller 60B, and the third
controller 60C may be integrated. Also, the above-described control over the traveling
system, control over the working system, and calculation of the vehicle-body position are not
meant to be restrictive. As described above, by the controllers 60, the tractor 1 (vehicle
body 3) can be automatically steered.
[0039] As depicted in FIG. 1, the tractor 1 includes the display device 45. The display
device 45 is a device capable of displaying various information regarding the tractor 1 and
capable of displaying at least operation information of the tractor 1. The display device 45 is
provided forward of the operator's seat 10.
The display device 45 includes a control unit (display control unit) 46 and a display
unit 47. The control unit 46 performs various controls regarding screen display of the
display device 45 and so forth. The control unit 46 is configured of an electric and
electronic circuit provided in the display device 45, a program stored in a CPU or the like, or
so forth. The display unit 47 is configured of a liquid-crystal panel or the like to display
various information in accordance with control by the control unit 46. Note that description
is hereinafter made by assuming that the control unit 46 controls the screen and so forth of the
display device 45.
[0040] As depicted in FIG. 4, when a predetermined operation is performed, the display
16

device 45 (control unit 46) displays an operation screen M1, a guidance screen M2, and a plurality of setting screens M3.
The operation screen M1 includes a rotation indicating graphic 62 for displaying the rotation speed of the prime mover 4 (prime mover rotation speed). The rotation indicating graphic 62 includes a level indicating graphic 62a which displays the prime mover rotation speed with a bar or the like and a numerical indicating graphic 62b which indicates the prime mover rotation speed by numbers. If setting of the traveling reference line L1 has been completed, the operation screen M1 displays a symbol mark 63a indicating that setting of the start point P10 of the traveling reference line L1 has been completed and a symbol mark 63b indicating that setting of the end point P1 1 of the traveling reference line L1 has been completed.
[0041] As depicted in FIG. 5, the guidance screen M2 includes a turn guidance screen M2a and an interrow guidance screen M2b. As depicted in FIG. 6A, after setting the end point P1 1 of the traveling reference line L1 or after the termination of automatic steering at a point P12, to start automatic steering, it is required to satisfy a condition for automatic steering after performing turn-traveling J1 of the tractor 1 with manual operation or the like. For example, as depicted in FIG. 6B, after turning of the tractor 1 and before automatic steering, if an azimuth difference AF3, which is a difference between an azimuth (vehicle-body azimuth) F1 of the tractor 1 in the forwarding direction and an azimuth (line azimuth) F2 of the traveling reference line L1 (scheduled traveling line L2) becomes greatly large, it is difficult to steer the tractor 1 along the scheduled traveling line L2 parallel to the traveling reference line L1 even if automatic steering starts. Note that the azimuth (line azimuth) F2 of the traveling reference line L1 (scheduled traveling line L2) matches a direction in which the line extends, and may be in a direction of the line from one end to the other end or in a direction of the line from the other end to one end. In other words, matching of the vehicle-body azimuth F1 and the line azimuth F2 (with no azimuth difference AF3) means a state in which the forwarding direction of the tractor 1 matches the direction in
which the traveling reference line L1 (scheduled traveling line L2) extends.
17

[0042] Thus, as depicted in FIG. 7A to FIG. 7C, the turn guidance screen M2a displays the azimuth difference AF3, which is a condition for a start of automatic steering. The operator can grasp that the condition for automatic steering is satisfied when the small azimuth difference AF3 is displayed on the turn guidance screen M2a.
The turn guidance screen M2a is described by using FIG. 7A to FIG. 7C. In the following description, the current scheduled traveling line L2 on which the tractor 1 (vehicle body 3) is traveling or the scheduled traveling line L2 immediately before the tractor 1 (vehicle body 3) terminates automatic steering may be represented as a "scheduled traveling line L2b" and the next-scheduled traveling line L2 after next automatic steering may be represented as a "scheduled traveling line L2c".
[0043] The turn guidance screen M2a includes a vehicle-body azimuth indicating graphic 64, a vehicle-body indicating graphic 65, and a reference azimuth indicating graphic 66. Note that for convenience of description, the vehicle-body azimuth indicating graphic 64 is indicated by a dotted line.
The vehicle-body azimuth indicating graphic 64 is an image indicating the vehicle-body azimuth F1, and is indicated by a straight line (straight line vertically extending on the turn guidance screen M2a) on the turn guidance screen M2a. The display position of the vehicle-body azimuth indicating graphic 64 is fixed on the turn guidance screen M2a and the position is not changed. The vehicle-body indicating graphic 65 is an image graphically indicating the vehicle body 3 and superposed on the vehicle-body azimuth indicating graphic 64. The vehicle-body indicating graphic 65 has a polygonal shape including a tip portion 65a with a pointed tip, and the tip portion 65a indicates a front portion of the tractor 1 (vehicle body 3).
[0044] The reference azimuth indicating graphic 66 is a portion indicating the azimuth F2 of the traveling reference line L1 (next-scheduled traveling line L2), and is indicated by a straight line on the turn guidance screen M2a. As depicted in FIG. 7A, when the vehicle-body azimuth F1 matches the line azimuth F2, the vehicle-body azimuth indicating
graphic 64 and the reference azimuth indicating graphic 66 are displayed as superposed.
18

Since the vehicle-body azimuth indicating graphic 64 and the reference azimuth indicating graphic 66 are differently colored, the operator and any other person can visually recognize that the vehicle-body azimuth F1 matches the line azimuth F2.
[0045] As depicted in FIG. 7B, when the turn-traveling J1 of the tractor 1 (vehicle body 3) causes increase of the azimuth difference AF3 between the vehicle-body azimuth F1 and the line azimuth F2, the control unit 46 changes the display position of the linear reference azimuth indicating graphic 66 in accordance with the azimuth difference AF3. Specifically, when the vehicle-body indicating graphic 65 is taken as a center O1, the reference azimuth indicating graphic 66 revolves about the center O1 of the vehicle-body indicating graphic in accordance with the magnitude of the azimuth difference AF3. The display device 45 (control unit 46) increases an angle 91 between the reference azimuth indicating graphic 66 and the vehicle-body indicating graphic 65 according to increase of the azimuth difference AF3, and decreases the angle 91 between the reference azimuth indicating graphic 66 and the vehicle-body indicating graphic 65 according to decrease of the azimuth difference AF3. As depicted in FIG. 7C, when a next line indicating graphic 68a or 68b and the vehicle-body indicating graphic 65 superpose each other, this indicates that the condition for automatic steering is satisfied. In other words, when the azimuth difference AF3 becomes equal to or smaller than a predetermined value, the condition for automatic steering is satisfied. [0046] Also, the turn guidance screen M2a displays the next line indicating graphics 68a and 68b. The line indicating graphic 68b is displayed when an adjacency width is changed as described further below. The next line indicating graphic 68a is an image indicating at least a next scheduled traveling line L2c as one next to the scheduled traveling line L2b on which the tractor 1 (vehicle body 3) has traveled, and indicates a straight-forwarding region on which the tractor 1 (vehicle body 3) forwards straight while using automatic steering. The line indicating graphic (straight-forwarding region) 68a is indicated at a position having a predetermined distance from the vehicle-body azimuth indicating graphic 64 on the turn guidance screen M2a.
[0047] As depicted in FIG. 5, the interrow guidance screen M2b is a screen indicating
19

that, while the condition for automatic steering is satisfied, the tractor 1 (vehicle body 3) is
being guided toward the next scheduled traveling line L2c by automatic steering separately
from the automatic steering control unit 200. The interrow guidance screen M2b includes
the next line indicating graphic 68a and a guide indicating graphic 69 indicating that the
tractor 1 (vehicle body 3) is being guided to the next line indicating graphic 68a by automatic
steering (an interrow assist is being performed).
[0048] As depicted in FIG. 8 to FIG. 10C, the plurality of setting screens M3 include a
home setting screen M3a and a detail setting screen M3b. For the home setting screen M3a
and the detail setting screen M3b, setting information is information relating to the vehicle
body 3, that is, information relating to automatic steering.
As depicted in FIG. 8, the home setting screen M3a displays setting items 70a to 70h
and set values 71a to 70h.
[0049] The setting item 70a is an item indicating sensitivity of automatic steering as the
set value 71a, and sensitivity can be set at any of three set values: sensitive, normal, and
insensitive. When the set value is set as sensitive, the automatic steering is performed with
large steering angles in correspondence to deviation (positional deviation, azimuth deviation)
during use of automatic steering. When the set value is set as insensitive, the automatic
steering is performed with small steering angles in correspondence to deviation (positional
deviation, azimuth deviation) during use of automatic steering. When the set value is set as
normal, the automatic steering is performed with steering angles that are between steering
angles when set as insensitive and steering angles when set as sensitive in correspondence to
deviation (positional deviation, azimuth deviation) during use of automatic steering. That is,
sensitivity indicates a degree of response to a change in steering angle in correspondence to
deviation (positional deviation, azimuth deviation).
[0050] The setting item 70b is an item indicating the turn guidance screen M2a (turn
guidance), and the set value 71b indicates ON/OFF indicating whether to display the turn
guidance screen M2a after automatic steering. When the set value 71b indicates "ON", the
turn guidance screen M2a is displayed. When the set value 71b indicates "OFF", the turn
20

guidance screen M2a is not displayed. That is, the set value 71b is to set whether to perform
turn guidance with the turn guidance screen M2a. The turn guidance screen M2a becomes
hidden at the time of starting automatic steering.
[0051] The setting item 70c is an item indicating the interrow guidance screen M2b
(interrow assist), and the set value 71c indicates ON/OFF indicating whether to display the
interrow guidance screen M2b at the time of starting automatic steering. When the set value
71c indicates "ON", the interrow guidance screen M2b is displayed. When the set value 71c
indicates "OFF", the interrow guidance screen M2b is not displayed. That is, the set value
71c is to set whether to perform an interrow assist by automatic steering.
[0052] The setting item 70d is an item indicating a count of times of turning by manual
steering (turn counter), i.e., the work count that is the number of times of work using
automatic steering along with the scheduled traveling line L2, and the set value 71d indicates
ON/OFF indicating whether to calculate the work count. When the set value 71d is "ON",
the work count is calculated. When the set value 71d is "OFF", the work count is not
calculated.
The setting item 70e is an item indicating what kind of work, and the set value 71e is
indicated as one selected from farm work names such as cultivation, puddling, ridge
plastering, and seeding. The setting item 70f is an item indicating a reference adjacency
width L11, and a numerical value of the reference adjacency width L11 is set in the set value
71f as a set value. The setting item 70g is an item indicating a variation adjacency width
(adjacent extension width) L12, and the set value 71g is indicated as a numerical value
representing the variation adjacency width L12. The setting item 70h is an item indicating
position correction (GPS position correction), and the set value 71h is indicated as a
numerical value of position correction.
[0053] The detail setting screen M3b is a screen for setting (inputting) and displaying the
set values 71a to 70h. When a predetermined operation is performed on the home setting
screen M3a, as depicted in FIG. 9, the home setting screen M3a is transited to the detail
setting screen M3b. The detail setting screen M3b includes a list display portion 72 for
21

displaying a list of the setting items 70a to 70h, and a cursor K10 is displayed on the list
display portion 72.
[0054] Among the plurality of setting items 70a to 70h, when a predetermined setting
item is selected with the cursor K10, the detail setting screen M3b proceeds to a screen for
inputting a set value corresponding to the selected setting item. For example, as depicted in
FIG. 9, when the setting item 70a indicating sensitivity is selected on the detail setting screen
M3b, as depicted in FIG. 10A, the detail setting screen M3b transits to a detail setting screen
M3b1 for changing sensitivity. On the detail setting screen M3b1, three set values, i.e.,
sensitive, normal, and insensitive, are displayed and, by selecting one set value pointed by the
cursor K10, the set value can be changed.
[0055] Also, on the detail setting screen M3b, when the set item 70f indicating the
reference adjacency width L11 is selected, as depicted in FIG. 10B, the detail setting screen
M3b transits to a detail setting screen M3b2 for changing the reference adjacency width L11.
On the detail setting screen M3b2, a reference input portion 75 for inputting the reference
adjacency width L11 is displayed. The reference input portion 75 includes a plurality of
digit input portions for inputting numerical values corresponding to respective digits,
including, for example, a first-digit input portion 75a for inputting a numerical value of the
first digit, a second-digit input portion 75b for inputting a numerical value of the second digit,
a third-digit input portion 75c for inputting a numerical value of the third digit, and a
determination portion 75d for determining a numerical value. Note that while the digit input
portions for inputting three-digit numbers are described for the reference input portion 75 in
this embodiment, the number of digits is not restrictive.
[0056] Also, when the setting item 70g indicating the variation adjacency width (adjacent
extension width) L12 is selected on the detail setting screen M3b depicted in FIG. 9, the detail
setting screen M3b transits to a detail setting screen M3b3 for adjusting the variation
adjacency width L12. On the detail setting screen M3b3, a variation input portion 76 for
inputting the variation adjacency width L12 is displayed. The variation input portion 76 is
configured of a plurality of digit input portions for inputting numerical values corresponding
22

to respective digits, including, for example, a first-digit input portion 76a for inputting a
numerical value of the first digit, a second-digit input portion 76b for inputting a numerical
value of the second digit, and a determination portion 75d for determining a numerical value.
Note that while the digit input portions for inputting two-digit numbers are described for the
variation input portion 76 in this embodiment, the number of digits is not restrictive.
[0057] As depicted in FIG. 1 and FIG. 17, the tractor 1 (vehicle body 3) includes an input
button 80. The input button 80 is connected to the display device 45 (control unit 46). The
input button 80 is, for example, an automatic-return-type push button (pressure button)
capable of being turned on and off. With a first operation and a second operation, the input
button 80 is capable of transiting the screen, moving the cursor K10, and setting a set value in
the plurality of setting screens M3.
[0058] As depicted in FIG. 17, the input button 80 can perform a short-press operation
with a push time (pressurization time, a time for keeping the button turned on) T10 being
short as a first operation, and can perform a long-press operation with the pressurization time
T10 being long as a second operation.
Note that the input button 80 is attached to, for example, a front cover (operation
console cover) 151 provided forward of the operator's seat 10. The display device 45, the
setting switch 51, the steering changeover switch 52, a correction switch 53, a shuttle lever 91,
and so forth are also attached to the operation console cover 151.
[0059] The display device 45 (control unit 46) performs transition among the plurality of
setting screens M3 when a long-press operation is performed, performs movement of the
cursor K10 to a desired setting item preselected from among the plurality of setting items 70a
to 70h when a short-press operation is performed on the setting screen M3 after the transition,
and further makes a determination of the desired setting item by performing a long-press
operation with the cursor K10 positioned at the desired setting item.
[0060] Specifically, as depicted in FIG. 8, on the home setting screen M3a, when a
long-press operation is performed on the input button 80, as depicted in FIG. 8 and FIG. 9, the
home setting screen M3a transits to the detail setting screen M3b. As depicted in FIG. 9, on
23

the detail setting screen M3b, the position of the cursor K10 is changed every time a short-press operation is performed on the input button 80, and the cursor K10 can be positioned at a desired setting item preselected from among the plurality of setting items 70a to 70h.
[0061] In FIG. 9, when a long-press operation is performed on the input button 80 with
the cursor K10 being positioned at the setting item 70a indicating sensitivity, the setting item 70a indicating sensitivity is determined and, as depicted in FIG. 10A, the detail setting screen M3b transits to the detail setting screen M3b1 for setting sensitivity.
Also, in FIG. 9, when a long-press operation is performed on the input button 80 with the cursor K10 being positioned at the setting item 70f indicating the reference adjacency width L11, the setting item 70f indicating the reference adjacency width L11 is determined and, as depicted in FIG. 10B, the detail setting screen M3b transits to the detail setting screen M3b2 for setting sensitivity.
[0062] Also, in FIG. 9, when a long-press operation is performed on the input button 80
with the cursor K10 being positioned at the setting item 70g indicating the variation adjacency width L12, the setting item 70g indicating the variation adjacency width L12 is determined and, as depicted in FIG. 10C, the detail setting screen M3b transits to the detail setting screen M3b3 for setting sensitivity.
As depicted in FIG. 10A, on the setting screen for setting a set value (detail setting
screen M3b1), when a short-press operation is performed, the display device 45 causes the
cursor K10 to be moved to any of the plurality of set values (sensitive, normal, insensitive)
and, when a long-press operation is performed with the cursor K10 positioned at a
predetermined set value, makes a determination of the desired set value. For example, when
a long-press operation is performed with the cursor K10 moved to sensitive with a short-press
operation, the set value can be set in a sensitive manner.
[0063] As depicted in FIG. 10B and FIG. 10C, on the setting screen for setting a set value
(detail setting screen M3b2, detail setting screen M3b3), when a short-press operation is
performed, the display device 45 causes the cursor K10 to be moved to a desired digit
24

preselected from among the plurality of digits as a set value, and when a long-press operation
is performed with the cursor K10 positioned at the desired digit, makes a determination of the
desired digit and, furthermore, changes the numerical value of the desired digit when a
short-press operation is performed after the desired digit is determined.
[0064] As depicted in FIG. 10B, on the reference input portion 75 of the detail setting
screen M3b2, when a short-press operation is performed on the input button 80, the cursor
K10 can be moved to any of the first-digit input portion 75a, the second-digit input portion
75b, the third-digit input portion 75c, and the determination portion 75d. For example, on
the third-digit input portion 75c, when a long-press operation is performed on the input button
80, the third digit is determined. After the third digit is determined, every time a short-press
operation is performed on the input button 80, the number is count up by one, and the third
digit number can be changed to any of 0 to 9. On the reference input portion 75, after
numerical values are inputted to the first-digit input portion 75a, the second-digit input
portion 75b, and the third-digit input portion 75c, a long-press operation is performed with the
cursor K10 moved to the determination portion 75d, thereby allowing the numerical values
inputted to the first-digit input portion 75a, the second-digit input portion 75b, and the
third-digit input portion 75c to be set as the reference adjacency width L11.
[0065] Also, as depicted in FIG. 10C, on the variation input portion 76 of the detail
setting screen M3b3, when a short-press operation is performed on the input button 80, the
cursor K10 can be moved to any of the first-digit input portion 76a, the second-digit input
portion 76b, and the determination portion 76c. When a long-press operation is performed
on the input button 80, the first-digit input portion 76a or the second-digit input portion 76b
can be determined. After the first-digit input portion 76a or the second-digit input portion
76b is determined, when a short-press operation is performed on the input button 80, the
number can be changed to any of 0 to 9. On the variation input portion 76, after numerical
values are inputted to the first-digit input portion 76a and the second-digit input portion 76b, a
long-press operation is performed with the cursor K10 moved to the determination portion
76c, thereby allowing the numerical values inputted to the first-digit input portion 76a and the
25

second-digit input portion 76b to be set as the variation adjacency width L12.
[0066] FIG. 11 is a diagram summarizing an operation flow by operation of the input
button 80.
In FIG. 11, when a short-press operation is performed (aas2, YES) on any of the
operation screen M1, the guidance screen M2, and the home setting screen M3a (S1),
transition is sequentially performed among the operation screen M1, the guidance screen M2,
and the home setting screen M3a (S3). When not a short-press operation but a long-press
operation is performed (S2, No), it is determined whether the present screen when the
long-press operation is performed is the home setting screen M3a (S4). When the present
screen is the home setting screen M3a (S4, Yes), the screen is transited to the detail setting
screen M3b (S5). On the detail setting screen M3b, when a short-press operation is
performed (S6, Yes), the cursor K10 is moved, that is, moved to a predetermined setting item
from among the plurality of setting items 70a to 70h (S7). When not a short-press operation
but a long-press operation is performed (S6, No), the desired setting item is determined, and
the screen is transited to one of the detail setting screens M3b1 to M3b3 in accordance with
the desired setting item (S8). When the detail setting screen M3b2 or M3b3 is displayed (S9,
Yes), it is determined whether the performed operation is a short-press operation (S10).
When the performed operation is a short-press operation (S10, Yes), the cursor K10 is moved
to a desired digit preselected from among a plurality of digits (S11). When a short-press
operation but a long-press operation is performed (S10, No), the desired digit is determined
(S12). When a short-press operation is performed (S13, Yes), a numerical value of the
desired digit is counted up (S14). When not a short-press operation but a long-press
operation is performed (S13, No), the numerical value of the desired digit is determined (S15).
When a long-press operation is performed with the cursor K10 moved to the determination
portion 75d or the determination portion 76c, the reference adjacency width L11 or the
variation adjacency width L12 can be set (S16). Note that the steps S11 to S15 can be
repeatedly performed.
[0067] When neither the detail setting screen M3b2 nor M3b3 is displayed, that is, the
26

detail setting screen M3b1is displayed (S9, No), it is determined whether the performed
operation is a short-press operation (S17). When the performed operation is a short-press
operation (S17, Yes), the cursor K10 is moved to a desired set value (sensitivity) preselected
from among the plurality of set values (sensitivity) (S19). When not a short-press operation
but a long-press operation is performed (S17, No), the desired set value (sensitivity) is
determined (S18).
[0068] As described above, with a short-press operation and a long-press operation on
one input button 80, it is possible to not only transit the screen among the plurality of setting
screens M3 but also change the set value. Note that the input button 80 can cause transition
to another screen, other than the transition among the plurality of setting screens M3. For
example, transition between the operation screen M1 and the guidance screen M2 can be
performed.
Meanwhile, when a work (ground work) is performed in an agricultural field H1, the
working device 2 corresponding to the work is coupled to the tractor 1, and the tractor 1 with
the working device 2 coupled thereto is caused to travel in the agricultural field H1. As
depicted in FIG. 12, for example, when a ground work is performed in the agricultural field
H1, the work is performed as straight forwarding and turning are repeated as indicated by the
scheduled traveling line L2. That is, the tractor 1 goes straight forward after turning when
approaching a furrow end, and turns again to approach an opposite furrow end and then goes
straight forward. Note that at the time of turning, the working device 2 in a working posture
is raised, and no work is performed in the turning region.
[0069] In this manner, in performing the work as repeatedly turning, automatic steering is
performed in straight-forwarding regions SLn (n is equal to 1, 2, 3...) represented as the
scheduled traveling line L2. For example, in a first straight-forwarding region SL1, the
operator operates the steering changeover switch 52 so that automatic steering starts at a start
position ST1 (STn: n is equal to 1). Then, the operator, while viewing a working state,
operates the steering changeover switch 52 so that automatic steering terminates at an end
position EN1 (ENn: n is equal to 1). Also, the operator operates the correction switch 53 in
27

accordance with the situation of automatic steering in the first straight-forwarding region SL1,
thereby finely adjusting the vehicle-body position of the tractor 1, and the operator operates
the accelerator 210 and the speed-shift member 211 in accordance with the work situation to
adjust the vehicle speed of the tractor 1.
[0070] Also, after termination of automatic steering at the end position EN1, the operator
performs manual steering of the tractor 1 for turning and operates the steering changeover
switch 52 in a second straight-forwarding region SL2 to start automatic steering at a start
position ST2, and operates the steering changeover switch 52 to terminate automatic steering
at an end position EN2. That is, in the agricultural field H1, the tractor 1 is manually steered
to travel in a turning region RLn connected with the straight-forwarding regions.
[0071] As described above, by operating the steering changeover switch 52 at the start
positions STn (n is equal to 1, 2, 3...) and the end positions ENn (n is equal to 1, 2, 3...), the
work is performed while automatic steering and manual steering are alternately repeated.
The scheduled traveling line L2 is set by a traveling line setting unit 201. The
traveling line setting unit 201 is configured of an electric and electronic circuit provided in the
second controller 60B, a program stored in a CPU or the like, or so forth. Note that the
traveling line setting unit 201 may be provided in the first controller 60A or the third
controller 60C and is not restrictive. The traveling line setting unit 201 sets the scheduled
traveling line L2 based on the traveling reference line L1. That is, the traveling line setting
unit 201 sets the straight-forwarding region SLn parallel to the traveling reference line L1
every time automatic steering is started. For example, when the first automatic steering is
started (in the case of n is equal to 1), the traveling line setting unit 201 sets the
straight-forwarding region SL1 that has a predetermined distance from the traveling reference
line L1. An adjacency width L10 between the traveling reference line L1 and the
straight-forwarding region SL1 is set at the reference adjacency width L11. Also, for
example, when the second automatic steering onward is started (in the case of n is equal to 2
or larger), the traveling line setting unit 201 sets the straight-forwarding region SLn (n is
equal to 2 or larger) that has a predetermined distance from the traveling reference line L1.
28

[0072] Here, the traveling line setting unit 201 can change the adjacency width L10
between adjacent scheduled traveling lines L2 among the plurality of scheduled traveling
lines L2. That is, the traveling line setting unit 201 can change the adjacency width L10
between an immediately-previous straight-forwarding region SLn-1 (n is equal to 2 or larger)
and an adjacent straight-forwarding region SLn (n is equal to 2 or larger) adjacent to the
immediately-previous straight-forwarding region SLn-1 (n is equal to 2 or larger).
[0073] As depicted in FIG. 1, the tractor 1 includes a changing operation member 81.
The changing operation member 81 is an ON/OFF switch, which issues therefrom an
instruction for changing the adjacency width L10 when it is turned on, and which does not
issues therefrom an instruction for changing the adjacency width L10 when it is turned off.
When an instruction for changing is issued from the changing operation member 81,
when a change instruction is issued, the traveling line setting unit 201 changes the adjacency
width L10. For example, when a change instruction is issued while the automatic steering is
performed, the traveling line setting unit 201 changes the adjacency width L10 between the
straight-forwarding region SLn-1 (n is equal to 2 or larger) where current automatic steering
is being performed and the next straight-forwarding region SLn (n is equal to 2 or larger). In
more detail, the traveling line setting unit 201 sets a value obtained by adding the variation
adjacency width L12 to the reference adjacency width L11 as the adjacency width L10 (L10 is
equal to L11 plus L12). For example, when automatic traveling is performed in the third
straight-forwarding region SL3 and a the changing operation member 81 is turned on to issue
a changing instruction that is an instruction for changing of the adjacency width, the traveling
line setting unit 201 determines the adjacency width L10 between the third
straight-forwarding region SL3 where current automatic steering is performed and the next
fourth straight-forwarding region SL4 as not equal to L11 but equal to L11 plus L12. When
the changing instruction is not issued for the next fourth straight-forwarding region SL4, the
adjacency width L10 from the fifth straight-forwarding region SL5 is returned to the reference
adjacency width L11.
[0074] Note that also when the changing operation member 81 is operated at a time
29

before start of automatic steering, e.g., during turning after termination of preceding
automatic steering, the traveling line setting unit 201 sets the adjacency width L10 between
the immediately-preceding straight-forwarding region SLn-1 (“n” is equal to 2 or larger)
where automatic traveling has already been performed and the next straight-forwarding region
SLn at L10 being equal to L11 plus L12. Also, when the changing instruction is not issued
from the changing operation member 81, the traveling line setting unit 201 determines the
reference adjacency width L11 as the adjacency width L10.
[0075] FIG. 13 is a diagram depicting a flow of changing the adjacency width L10 by the
changing operation member 81.
In FIG. 13, either during automatic steering or after automatic steering is terminated,
it is determined whether the changing instruction is issued (S20). When the changing
instruction is issued (S20, Yes), the traveling line setting unit 201 changes the adjacency
width L10 to a value obtained by adding the variation adjacency width L12 to the reference
adjacency width L11 as the adjacency width L10 in the next-scheduled traveling line L2c
(S21). When the changing instruction is not issued (S20, Yes), the traveling line setting unit
201 fixes the adjacency width L10 at the reference adjacency width L11 and does not make a
change in the next-scheduled traveling line L2c (S22). When the work ends (S23, Yes), the
traveling line setting unit 201 ends the process. When the work does not end, the process
returns to S20. As depicted in FIG. 13, the adjacency width L10 of the next-scheduled
traveling line L2c is allowed to change when the changing instruction is issued, and the
adjacency width L10 of the next-scheduled traveling line L2c is not allowed to change when
no change is made in the changing instruction.
[0076] Note that the correction switch 53 may serve as the changing operation member
81. The correction switch 53 is a switch for correcting the vehicle-body position
(positioning position) found by the positioning device 40, and is a switch swingable to one
side (left side) and the other side (right side). The correction switch 53 is, for example, a
switch configured so that, when it is short-pressed to swing to the left side, the positionally
detected position is correctly shifted to the right side of the vehicle body 3 so as to cause the
30

tractor 1 (vehicle body 3) to turn to the left side by automatic steering, and when it is
short-pressed to swing to the right side, the positionally detected position is correctly shifted
to the left side of the vehicle body 3 so as to cause the tractor 1 (vehicle body 3) to turn to the
right side by automatic steering. The changing instruction may be issued when the
correction switch 53 is long-pressed to swing to the left or right side.
[0077] Also, the display device 45 may serve as the changing operation member 81. For
example, an adjacency width change icon may be provided on the screen of the display device
45 and a changing instruction may be issued when the icon is pressed.
Meanwhile, while the adjacency width L10 is changed by manually operating the
changing operation member 81 in the above-described embodiment, the adjacency width L10
may be changed automatically.
[0078] The tractor 1 includes a calculation unit 202. The calculation unit 202 calculates
a work count of performing a ground work (the number of ground works). For example,
since the tractor 1 performs a work (ground work) as going straight forward, a total of the
number of traveling reference lines L1 and the number of straight-forwarding regions SLn can
be taken as a number of works (work count) WTi in the agricultural field H1. That is, the
work count WTi can be represented as being equal to the number of traveling reference lines
L1 plus the number of straight-forwarding regions SLn. Note that since the traveling
reference line L1 may be set without performing a work, the work count WTi may be the
number of straight-forwarding regions SLn without including the number of traveling
reference lines L1.
[0079] Specifically, the calculation unit 202 takes the number of times of switching of the
steering changeover switch 52 to either of the position for start of automatic steering and the
position for termination of automatic steering as the work count WTi. For example, after
setting of the traveling reference line L1 is completed, the calculation unit 202 sets the
number of times of selecting a start of automatic steering by use of the steering changeover
switch 52 (start switching count) as the work count WTi. In other words, calculation unit
202 sets the number “n” of the start position STn at the work count WTi.
31

[0080] Alternatively, after setting of the traveling reference line L1 is completed, the
calculation unit 202 sets the number of times of selecting a termination of automatic steering by use of the steering changeover switch 52 (termination switching count) as the work count WTi. In other words, calculation unit 202 sets the number “n” of the end position ETn at the work count WTi.
Alternatively, the calculation unit 202 may set the number of times of turnings of the
vehicle body 3 by manual steering (termination switching count) as the work count WTi.
For example, after the traveling reference line L1 is set, the calculation unit 202 determines
whether manual steering is being performed. When determining that manual steering is
being performed, the calculation unit 202 monitors the steering angle of the steering device 11
in manual steering. Then, when the steering angle of the steering device 11 in manual
steering becomes equal to or larger than a turn threshold value (value allowing a
determination that turning is being performed), it is determined that the vehicle body 3 turns
and the turn count is kept. In other words, the calculation unit 202 sets the number “n” of
the turn region RLn on the scheduled traveling line L2 at the work count WTi.
[0081] Note that which of the start switching count, termination switching count, and
termination switching count is set at the work count WTi can be set on the setting screen or the like of the display device 45. As depicted in FIG. 7A to FIG. 7C, on the turn guidance screen M2a, the work count WTi may be displayed in a count display portion 90.
When the work count WTi calculated by the calculation unit 202 reaches a
predetermined count, the traveling line setting unit 201 changes the adjacency width L10.
Specifically, the traveling line setting unit 201 changes the adjacency width L10 to a value
obtained by adding the variation adjacency width L12 to the reference adjacency width L11
when the work count WTi reaches the predetermined count, and changes the reference
adjacency width L11 to the adjacency width L10 when the work count WTi does not reach the
predetermined count. For example, when the work count WTi in the straight-forwarding
region SLn-1 (n is equal to or larger than 2) where current automatic steering is being
performed is ten and the predetermined count is ten, the adjacency width L10 between the
32

straight-forwarding region SLn-1 (n is equal to or larger than 2) and the next
straight-forwarding region SLn (n is equal to or larger than 2) is set at not L10 being equal to
L11 but L10 being equal to L11 plus L12.
[0082] FIG. 14 is a diagram depicting a flow of automatically changing the adjacency
width L10.
In FIG. 14, the work count WTi is calculated by the calculation unit 202 (S30). It is
determined whether the work count WTi has reached a predetermined count defined in
advance (S31). If the work count WTi has reached the predetermined count (S31, Yes), the
traveling line setting unit 201 changes the adjacency width L10 to a value obtained by adding
the variation adjacency width L12 to the reference adjacency width L11 in the next scheduled
traveling line L2c (S32). After changing the adjacency width L10, the traveling line setting
unit 201 resets the work count WTi (S33). If the work count WTi has not reached the
predetermined count (S31, No), the traveling line setting unit 201 fixes the adjacency width
L10 at the reference adjacency width L11 and does not make a change in the next scheduled
traveling line L2c (S34). When the work ends (S35, Yes), the traveling line setting unit 201
ends the process. When the work does not end, the process returns to S30. As depicted in
FIG. 14, for each work count, the adjacency width L10 of the next scheduled traveling line
L2c can be changed. Note that the predetermined count can be set on the setting screen of
the display device 45.
[0083] As depicted in FIG. 7A to FIG. 7C, when the adjacency width L10 is changed,
that is, when the variation adjacency width L12 is added to the reference adjacency width L11,
the next line indicating graphic 68b different from the next line indicating graphic 68a is
displayed on the turn guidance screen M2a. The next line indicating graphic 68a is the
straight-forwarding region SLn-1 (n is equal to 2 or larger) when the adjacency width L10 is
the reference adjacency width L11, and the next line indicating graphic 68b is the
straight-forwarding region SLn (n is equal to 2 or larger) when the adjacency width L10 is the
reference adjacency width L11 added with the variation adjacency width L12. With this,
when the next line indicating graphic 68b is displayed on the turn guidance screen M2a, the
33

operator can grasp that the adjacency width L10 is extended (changed) for the next-scheduled
traveling line L2c.
[0084] Meanwhile, when the adjacency width L10 is changed, the interrow assist for
guiding the tractor 1 (vehicle body 3) to the next-scheduled traveling line L2c by automatic
steering becomes different. As depicted in FIG. 1, the tractor 1 includes a first assist control
unit 204 and a second assist control unit 205. The first assist control unit 204 and the second
assist control unit 205 are configured of electric and electronic circuits provided in the second
controller 60B, a program stored in a CPU or the like, or so forth. Note that they may be
provided in the first controller 60A or the third controller 60C and are not restrictive.
[0085] As depicted in FIG. 15A, when the adjacency width L10 is unchanged, after
automatic steering is terminated, separately from the automatic steering control unit 200, the
first assist control unit 204 automatically guides the vehicle body 3 to a next-scheduled
traveling line L2c1 (straight-forwarding region SLn-1 (“n” is equal to 2 or larger)) with the
unchanged adjacency width L10. The first assist control unit 204 refers to the vehicle-body
position detected by the positioning device 40 to automatically change the steering angle so
that the vehicle-body position approaches the next-scheduled traveling line L2c1 and match
the vehicle-body position with the next-scheduled traveling line L2c1.
[0086] As depicted in FIG. 15B, when the adjacency width L10 is changed, after
automatic steering is terminated, separately from the automatic steering control unit 200, the
second assist control unit 205 automatically guides the vehicle body 3 to a next-scheduled
traveling line L2c2 (straight-forwarding region SLn (“n” is equal to 2 or larger)) with the
changed adjacency width L10. The second assist control unit 205 refers to the vehicle-body
position detected by the positioning device 40 to automatically change the steering angle so
that the vehicle-body position approaches the next-scheduled traveling line L2c2 and matches
the vehicle-body position with the next-scheduled traveling line L2c2.
[0087] While the automatic steering during forward traveling of the tractor 1 (vehicle
body 3) has been described in the above-described embodiment, it is also possible to perform
the automatic steering during rearward traveling of the tractor 1 (vehicle body 3). When
34

rearward traveling by the automatic steering is to be performed, the shuttle lever 91 disposed in the vicinity of the operator's seat 10 is first switched from a neutral position to a rearward-traveling side, and a forward-rearward traveling switching portion 13 is switched to a rearward-traveling side. During the rearward traveling, the operator performs manual steering to satisfy the condition for automatic steering so as to make the azimuth difference AF3 between the vehicle-body azimuth F1 and the line azimuth F2 equal to or smaller than a predetermined value, in the same way as that during forward traveling. [0088] When forward traveling by the automatic steering is to be performed, the operator viewing the display device 45 disposed forward of the driver’s seat 10 performs manual steering so as to satisfy the condition for automatic steering. On the other hand, when rearward traveling by the automatic steering is to be performed, the operator viewing rearward performs manual steering so as to satisfy the condition for automatic steering, and thus it is difficult to view the display device 45 disposed forward of the operator's seat 10. Thus, the tractor 1 includes a notification device 95 for issuing a notification of information about automatic steering aside from the display device 45 disposed forward of the operator's seat 10. The notification device 95 is configured of a device outputting sound (voice), e.g., a loudspeaker or a buzzer, or for a device outputting light, e.g., a lamp or an LED, or the like. The notification device 95 is disposed in the perimeter of the operator's seat 10 when the device is the loudspeaker or the buzzer, and is disposed on a lateral side or rearward of the operator's seat 10 when the device is the lamp or the LED.
[0089] When rearward traveling by the automatic steering is to be performed, the notification device 95 issues a notification, by using sound or light, as to whether the condition for starting automatic steering is satisfied. For example, as depicted in a section T1 of FIG. 16, as the azimuth difference AF3 decreases, an ON (output)/OFF (stop) interval of the loudspeaker, buzzer, lamp, or LED is shortened. That is, as the azimuth difference AF3 decreases, the interval of outputting sound is shortened for the loudspeaker or the buzzer, or the interval of lighting is shortened for the lamp or the LED. As depicted in a section T2
of FIG. 16, when the azimuth difference AF3 is equal to or smaller than the predetermined
35

value and the condition for automatic steering is satisfied, the ON/OFF interval of the
loudspeaker, buzzer, lamp, or LED is retained. That is, as depicted in the sections T1 and T2,
the notification device 95 makes the sound or light mode after the condition for automatic
steering is satisfied different from the sound or light mode before the condition for automatic
steering is satisfied. As depicted in a section T3 of FIG. 16, when rearward traveling using
automatic steering is started, the notification device 95 stops (turns OFF) outputting.
[0090] Note that as depicted in FIG. 18, in addition to the notification device 95, a
notification device 96 may be provided at a rear portion of the tractor 1 (vehicle body 3) to
notify the outside that the tractor 1 is to travel rearward by automatic steering. Also, the
notification device 95 may serve as the notification device 96. When serving as the above,
the notification device 95 does not stop outputting.
When forward traveling using automatic steering is to be performed, for example,
when the shuttle lever 91 is switched to a forward-traveling side after the traveling reference
line L1 is registered, the display device 45 displays the turn guidance screen M2a indicating
the condition to be satisfied for starting automatic steering. On the other hand, when
rearward traveling using automatic steering is to be performed, for example, when the shuttle
lever 91 is switched to a rearward traveling side after the traveling reference line L1 is
registered, the display device 45 displays a screen at least different from the turn guidance
screen M2a, for example, the operation screen M1 or a screen M5 for encouraging a look
rearward. On the screen M5, for example, a display is made indicating “Please look
rearward because of rearward traveling using automatic steering”, or the like. In this manner,
when rearward traveling using automatic steering is to be performed, the operator attends not
to the display device 45 but to the notification device 95, thereby improving operability of
automatic-steering during rearward traveling.
[0091] The working vehicle 1 includes the vehicle body 3 capable of traveling either by
manual steering with the steering wheel 30 or by automatic steering with the steering wheel
30, the reference registering unit 150 which registers the traveling reference line L1 based on
the position of the vehicle body 3 caused to travel by the manual steering, the traveling line
36

setting unit 201 to set, based on the traveling reference line L1, the plurality of scheduled
traveling lines L2 for traveling using the automatic steering, and the automatic steering
control unit 200 to control the automatic steering based on the scheduled traveling lines L2.
The traveling line setting unit 201 is configured or programmed to change the adjacency
width L10 between scheduled traveling lines L2 adjoining each other among the plurality of
scheduled traveling lines L2. According to this, for example, in a situation in which a work
is performed by using automatic steering, the adjacency width L10 can be changed in
accordance with the working situation and so forth. For example, when a passage is
required for traveling of another tractor (vehicle body) in the agricultural field to perform
pest control, the adjacency width is increased or decreased in accordance with the size of the
other tractor, thereby allowing the passage for the subsequent work or the like to be allocated.
Alternatively, automatic steering can be performed in accordance with various situations, such
as when it is required to partially change the ridge width.
[0092] The working vehicle 1 includes the changing operation member 81 operable to
issue an instruction for changing of the adjacency width L10. The traveling line setting unit
201 is configured or programmed to change the adjacency width L10 when the instruction for
the changing is issued from the changing operation member 81. According to this, the
adjacency width L10 can be changed only when the instruction for the changing is issued by
the changing operation member 81 used by the operator or the like.
The working vehicle 1 includes the calculation unit 202 to calculate the work count
WTi that is a count of times of performing a ground work. The traveling line setting unit
201 is configured or programmed to change the adjacency width L10 based on a
predetermined count reached by the work count WTi calculated by the calculation unit 202.
According to this, the adjacency width L10 can be automatically changed every time the work
count WTi becomes the predetermined count.
[0093] The working vehicle 1 includes the display device 45 having the reference input
portion 75 to input the reference adjacency width L11, which is a reference width between the
scheduled traveling lines L2 adjoining each other, and the variation input portion 76 to input
37

the variation adjacency width L12. The traveling line setting unit 201 is configured or
programmed to change the adjacency width based on the reference adjacency width L11 and
the variation adjacency width L12. According to this, for example, each of the reference
adjacency width L11 and the variation adjacency width L12 can be easily set, and the
adjacency width L10 can be easily changed with the variation adjacency width L12 only when
it is required to change the adjacency width L10 while automatic steering is performed with
the reference adjacency width L11.
[0094] The traveling line setting unit 201 is configured or programmed to change the
adjacency width L10 to a value obtained by adding the variation adjacency width L12 to the
reference adjacency width L11 when the instruction for the changing is issued by the
changing operation member 81, and set the reference adjacency width L11 as the adjacency
width L10 when the instruction for the changing is not issued by the changing operation
member 81. According to this, for example, each of the reference adjacency width L11 and
the variation adjacency width L12 can be easily set, and the adjacency width L10 can be
easily changed with the variation adjacency width L12 only when the instruction for the
changing is issued from the changing operation member 81 by the operator or the like while
automatic steering is performed with the reference adjacency width L11.
[0095] The traveling line setting unit 201 is configured or programmed to change the
adjacency width L10 to a value obtained by adding the variation adjacency width L12 to the
reference adjacency width L11 when the work count WTi calculated by the calculation unit
202 reaches the predetermined count, and set the reference adjacency width L11 as the
adjacency width L10 when the work count WTi does not reach the predetermined count.
According to this, for example, each of the reference adjacency width L11 and the variation
adjacency width L12 can be easily set, and the adjacency width L10 can be easily changed
automatically with the variation adjacency width L12 every time the work count WTi
becomes the predetermined count, while automatic steering is performed with the reference
adjacency width L11.
[0096] The working vehicle 1 includes the first assist control unit 204 configured or
38

programmed so that, when the adjacency width L10 is unchanged, the first control unit 204
automatically guides, after the automatic steering is terminated, the vehicle body 3 to the
scheduled traveling lines L2 with the unchanged adjacency width L10, and the second assist
control unit 205 configured or programmed so that, when the adjacency width L10 is changed,
the second assist control unit 205 automatically guides, after the automatic steering is
terminated, the vehicle body 3 to the scheduled traveling lines L2 with the changed adjacency
width L10. According to this, it is possible to not only facilitate entry of the working vehicle
1 into the scheduled traveling line L2 corresponding to the reference adjacency width L11 but
also facilitate entry of the working vehicle 1 into the scheduled traveling line L2 with the
changed adjacency width L10.
[0097] The working vehicle 1 includes the vehicle body 3 capable of traveling, the
coupling portion 8 provided on the vehicle body 3 and configured to couple the work device
to the vehicle body 3, the display device 45 capable of displaying the plurality of setting
screens M3 for inputting or displaying setting information including the setting items 70a to
70h and the set values 71a to 71h regarding settings regarding the vehicle body 3, and the
input button 80 for inputting setting information and transition among the plurality of setting
screens M3 with the first operation and the second operation. According to this, with only
two operations, the first operation and the second operation, it is possible to input setting
information including the setting items 70a to 70h and the set values 71a to 71h and the
setting screens M3. That is, screen transition and setting can be performed with the least
number of buttons (input button 80), and it is thus possible not only to decrease the number of
members but also to make the space of the input button and so forth compact.
[0098] The input button 80 is configured to be operated by the first operation, which is a
short-press operation performed for a short pressurization time, or the second operation,
which is a long-press operation performed for a long pressurization time that is longer than
the first operation. According to the long-press operation, the display device 45 performs
transition among the plurality of setting screens M3. According to the short-press operation,
on the setting screen M3 after the transition, the cursor moves to a desired setting item
39

preselected from among the plurality of setting items 70a to 70h. Furthermore, when the
long-press operation is performed and the cursor is positioned on the setting item, the desired
setting item is determined. According to this, by the long-press operation, the transition
among the plurality of setting screens M3 and determination of one of the setting items 70a to
70h can be performed. When the short-press operation is performed, the desired setting item
can be selected from among the plurality of setting items 70a to 70h. Operability can be
improved because only one button is required.
[0099] The display device 45 is capable of displaying a screen different from the setting
screens M3. The input button 80 is switched by a short-press operation to transit the setting
screen to another screen. According to this, a screen other than the setting screens M3 for
inputting setting information can be displayed by a short-press operation and, also in view of
this, operability can be improved.
The display device 45 moves the cursor K10 to a predetermined digit among the
plurality of digits of the set value when a short-press operation is performed on the setting
screen for setting the set value (detail setting screen M3b2, detail setting screen M3b3); with
the cursor K10 being positioned at a predetermined digit, determines that predetermined digit
when a long-press operation is performed; and, furthermore, after determining the
predetermined digit, when a short-press operation is performed, changes the numerical value
of the predetermined digit. According to this, when a set value having a plurality of digits is
set, a predetermined digit can be determined among the plurality of digits with a long-press
operation, and the predetermined digit and the numerical value can be changed with a
short-press operation. That is, only with one button, a set value configured of a plurality of
digits can be set with a long-press operation and a short-press operation.
[0100] The vehicle body 3 is capable of traveling by either manual steering with the
steering wheel 30 or automatic steering with the steering wheel 30, and the display device 45
displays the setting items 70a to 70h and the set values 71a to 71h regarding automatic
steering as setting information. According to this, it is possible to not only easily confirm
the setting items 70a to 70h and the set values 71a to 71h regarding automatic steering but
40

also easily set the set values 71a to 71h for automatic steering with the input button 80.
[0101] The working vehicle 1 includes the reference registering unit 150, the traveling
line setting unit 201, and the automatic steering control unit 200. According to this, it is
possible to easily set the traveling reference line L1, the scheduled traveling line L2 and
perform automatic steering.
The display device 45 displays the setting screen M3 for setting the adjacency width
L10 between scheduled traveling lines L2 adjoining each other from among the plurality of
scheduled traveling lines L2. According to this, with combination of the setting screen M3
and the input button 80, the set value of the adjacency width L10 can be easily displayed and
set.
[0102] The working vehicle 1 includes the vehicle body 3, the reference registering unit
150, the automatic steering control unit 200, the display device 45 configured or programmed
to display information about automatic steering when rearward traveling by the automatic
steering is to be performed, the notification device 95 configured or programmed to issue a
notification about automatic steering aside from the display device 45 when rearward
traveling by the automatic steering is to be performed. According to this, when forward
traveling by the automatic steering is to be performed, the operator who watches the display
device 45 can confirm information about the automatic steering, and additionally, when
rearward traveling by the automatic steering is to be performed, the operator who does not
watch the display device 45 can use the notification device 95 to confirm information about
the automatic steering.
[0103] The working vehicle 1 includes the steering changeover switch 52 operable to
selectively start or terminate the automatic steering. After the automatic steering is
terminated, and when forward traveling by the automatic steering is to be performed, the
display device 45 displays a guidance screen (turn guidance screen M2a) indicating the
condition to be satisfied for starting the automatic steering. When rearward traveling by the
automatic steering is to be performed, the notification device 95 issues a notification, by using
sound or light, as to whether the condition for starting the automatic steering is satisfied.
41

According to this, when forward traveling by the automatic steering is to be performed, the operator who watches the guidance screen (turn guidance screen M2a) can confirm the condition to be satisfied for starting the automatic steering, and when rearward traveling by the automatic steering is to be performed, the operator also can confirm the condition to be satisfied for starting the automatic steering due to the sound or light. [0104] The display device 45 displays a state in which the condition for starting automatic steering is satisfied on the guidance screen (turn guidance screen M2a) in accordance with the azimuth difference AF3 between the azimuth of the traveling reference line L1 and the azimuth of the vehicle body 3. According to this, when forward traveling using automatic steering is performed, the operator can easily confirm the situation of the azimuth difference AF3 between the azimuth of the traveling reference line L1 and the azimuth of the vehicle body 3 by viewing the guidance screen (turn guidance screen M2a). [0105] The notification device 95 issues a notification as to whether the condition for starting automatic steering by changing the mode of sound or light in accordance with the azimuth difference AF3 between the azimuth of the traveling reference line L1 and the azimuth of the vehicle body 3. According to this, when rearward traveling by the automatic steering is to be performed, the operator can easily confirm the situation of the azimuth difference AF3 due to the sound or light.
When rearward traveling by the automatic steering is to be performed, the display device 45 displays a screen at least different from the guidance screen (turn guidance screen M2a). According to this, the operator who intends to satisfy the condition for starting the automatic steering for rearward traveling is prevented from viewing the guidance screen (turn guidance screen M2a) for forward traveling.
[0106] When rearward traveling by the automatic steering is to be performed, the display device 45 displays the screen M5 for encouraging a look rearward. According to this, when the operator watches the screen to satisfy the condition for starting rearward traveling by the automatic steering, attention can be called (encouraged) rearward, and the rearward traveling
by the automatic steering can be smoothly performed.
42

The embodiment disclosed herein should be construed as being an example in all aspects and not being restrictive. The scope of the present invention is indicated not by the above description but by the scope of claims, and is intended to include all modifications in the scope of claims and the meanings and scopes of equivalents.
[0107] In the above-described embodiment, the adjacency extension width is set as the
variation adjacency width L12 and, when an instruction for the changing is issued from the changing operation member 81, the traveling line setting unit 201 is configured or programmed to change the adjacency width L10 to a value obtained by adding the variation adjacency width L12 to the reference adjacency width L11. However, it may be configured that a predetermined adjacency width is set as the variation adjacency width L12 and, when an instruction for the changing is issued by the changing operation member 81, the traveling line setting unit 201 changes the adjacency width L10 to the value of the variation adjacency width L12.
[DESCRIPTION OF THE REFERENCE NUMERAL]
[0108]

1 Working vehicle (tractor)
3 Vehicle body
30 Steering wheel
45 Display device
46 Control unit
75 Reference input portion
76 Variation input portion
81 Changing operation member
150 Reference registering unit
200 Automatic steering control
201 Traveling line setting unit
202 Calculation unit
43

204 First assist control unit
205 Second assist control unit L1 Traveling reference line L10 Adjacency width
L11 Reference adjacency width L12 Variation adjacency width L2 Scheduled traveling line L2b Scheduled traveling line L2c Scheduled traveling line L2c1 Scheduled traveling line L2c2 Scheduled traveling line WTi Work count

WE CLAIMS

A working vehicle, comprising:
a vehicle body to travel either by manual steering with a steering wheel or by automatic steering with the steering wheel;
a reference registering unit which registers a traveling reference line based on a position of the vehicle body caused to travel by the manual steering;
a traveling line setting unit configured or programmed to set, based on the traveling reference line, a plurality of scheduled traveling lines for traveling using the automatic steering; and
an automatic steering control unit to control the automatic steering based on the scheduled traveling lines, wherein
the traveling line setting unit is configured or programed to change an adjacency width between the scheduled traveling lines adjoining each other among the plurality of scheduled traveling lines.
2. The working vehicle according to claim 1, further comprising:
a changing operation member operable to issue therefrom an instruction for changing of the adjacency width, wherein
the traveling line setting unit is configured or programmed to change the adjacency width when the instruction for the changing is issued from the changing operation member.
3. The working vehicle according to claim 1 or 2, further comprising:
a calculation unit to calculate a work count that is a count of times of performing a ground work, wherein
the traveling line setting unit is configured or programmed to change the adjacency width based on a predetermined count reached by the work count calculated by the calculation unit.
45

4. The working vehicle according to any one of claims 1 to 3, further comprising:
a display device having a reference input portion to input a reference adjacency width, which is a reference width between the scheduled traveling lines adjoining each other, and a variation input portion to input a variation adjacency width, wherein
the traveling line setting unit is configured or programmed to change the adjacency width based on the reference adjacency width and the variation adjacency width.
5. The working vehicle according to claim 2 or 4, further comprising:
a display device having a reference input portion to input a reference adjacency width, which is a reference width between the scheduled traveling lines adjoining each other, and a variation input portion to input a variation adjacency width, wherein
the traveling line setting unit is configured or programmed to change the adjacency width to a value obtained by adding the variation adjacency width to the reference adjacency width when the instruction for the changing is issued from the changing operation member, and set the reference adjacency width as the adjacency width when the instruction for the changing is not issued from the changing operation member.
6. The working vehicle according to claim 3 or 4, further comprising:
a reference input portion to input a reference adjacency width, which is a reference width between the scheduled traveling lines adjoining each other, and a variation input portion to input a variation adjacency width, wherein
the traveling line setting unit is configured or programmed to change the adjacency width to a value obtained by adding the variation adjacency width to the reference adjacency width when the work count calculated by the calculation unit reaches a predetermined count, and set the reference adjacency width as the adjacency width when the work count does not reach the predetermined count.
7. The working vehicle according to claim 1 to 5, further comprising:
46

a first assist control unit configured or programmed so that, when the adjacency width is unchanged, the first assist control unit automatically guides, after the automatic steering is terminated, the vehicle body to the scheduled traveling lines with the unchanged adjacency width; and
a second assist control unit configured or programmed so that, when the adjacency width is changed, the second assist control unit automatically guides, after the automatic steering is terminated, the vehicle body to the scheduled traveling lines with the changed adjacency width.
8. The working vehicle according to claim 1 to 7, further comprising:
a display device to display information about the vehicle body; and a display control unit to cause the display device to display a scheduled traveling line
on which the vehicle body travels and a next-scheduled traveling line adjoining the scheduled
traveling line, wherein
when an adjacency width between scheduled traveling lines adjoining each other is
changed, the display control unit causes the display device to display the next-scheduled
traveling line to be scheduled after the changing.