Work vehicle

Abstract

To provide a work vehicle which can perform various types of automatic steering, while alleviating labor required for setting a travelling reference.SOLUTION: A work vehicle includes: a travelling device 11 which can be steered; and a steering control part 30 which has a plurality of control modes, and which can execute automatic steering for making a machine body travel automatically along a travelling reference, by controlling the travelling device 11.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a work vehicle. [Background technology]

[0002] For example, the work vehicle disclosed in Patent Document 1 (referred to as a "rice transplanter" in the document) is configured to be capable of traveling with automatic steering (referred to as an "automatic straight-line mode" in the document) based on a pre-set driving standard (referred to as a "teaching direction" in the document), and also with manual steering (referred to as a "manual mode" in the document). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-136015 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, if a configuration were available that allowed automatic steering even if it did not follow pre-set driving standards, it would be convenient because it would allow for a variety of automatic steering operations. However, with the configuration of the work vehicle disclosed in Patent Document 1, when performing automatic steering that does not follow pre-set driving standards, it is necessary to set the driving standards again, which makes the work before actually starting automatic steering cumbersome.

[0005] In addition, if the driving standards are reset when automatic steering that does not comply with the driving standards is temporarily performed, there is a risk that the already set driving standards will have to be deleted or that multiple unnecessary driving standards will have to be managed, which will require a lot of work for the operator or manager.

[0006] An object of the present invention is to provide a work vehicle capable of performing a variety of automatic steering operations while reducing the effort required to set driving standards. [Means for solving the problem]

[0007] The work vehicle of the present invention is a work vehicle that travels while switching between manual steering and automatic steering, and is equipped with a steerable traveling device, and a steering control unit having a plurality of control modes and capable of performing the automatic steering by controlling the traveling device to automatically travel the vehicle in accordance with a traveling criterion, the steering control unit being configured to be able to switch the control mode between a first automatic steering mode in which the automatic steering is performed based on the traveling criterion that has been set in advance, and a second automatic steering mode in which the automatic steering is performed after the traveling criterion has been determined by traveling with the manual steering, and is equipped with a switching operation device that accepts manual operation for switching the control mode.

[0008] According to the present invention, the steering control unit has a first automatic steering mode and a second automatic steering mode as a plurality of control modes, and for example, an operator can change the control mode between the first automatic steering mode and the second automatic steering mode by operating a switching operation tool. In the second automatic steering mode, automatic steering is performed after a driving criterion is determined by driving with manual steering. For this reason, for example, when an operator desires temporary automatic steering based on a criterion other than the previously set driving criterion, the operator can easily perform temporary automatic steering by operating the switching operation tool to switch the control mode to the second automatic steering mode. Therefore, the present invention does not require the operator or manager to delete the already set driving criterion once or to manage multiple extra driving criteria, and does not require much effort. This realizes a work vehicle capable of various automatic steering while reducing the effort required for setting the driving criterion.

[0009] In the present invention, it is preferable that the driving reference is a reference direction for performing the automatic steering.

[0010] This configuration makes it possible to perform automatic steering along a reference direction.

[0011] In the present invention, it is preferable that the driving reference is a route that serves as a reference for performing the automatic steering.

[0012] This configuration makes it possible to perform automatic steering along a reference route.

[0013] In the present invention, the vehicle is provided with a boarding section on which a passenger can board, and a steering operation device provided in an area on one of the left or right ends of the boarding section and which accepts the manual steering by the passenger, and it is preferable that the switching operation device is provided on the side of the boarding section where the steering operation device is located.

[0014] With this configuration, the operator (passenger) can easily see ahead from the boarding section, compared to a configuration in which the steering operation tool and the switching operation tool are provided in the left and right central area of ​​the boarding section. Also, with this configuration, the steering operation tool and the switching operation tool are provided together in an area on one left or right end side of the boarding section. Therefore, compared to a configuration in which the steering operation tool and the switching operation tool are provided separately on one left or right side and the other left or right side of the boarding section, the operator can use the steering operation tool and the switching operation tool selectively with only one hand.

[0015] In the present invention, it is preferable that the switching operation tool is provided above the steering operation tool.

[0016] With this configuration, the steering operation device and the switching operation device are arranged vertically, and the switching operation device is located above the steering operation device, so that the operator can operate the switching operation device by simply moving one hand above the steering operation device.

[0017] In the present invention, it is preferable that the switching operating device has a first operating unit that accepts manual operation to switch the control mode to the first automatic steering mode, and a second operating unit that accepts manual operation to switch the control mode to the second automatic steering mode.

[0018] With this configuration, for example, when an operator desires automatic steering based on a preset driving criterion, the operator can switch the control mode to the first automatic steering mode by operating the first operation unit. Also, when the operator desires temporary automatic steering based on a criterion other than the preset driving criterion, the operator can switch the control mode to the second automatic steering mode by operating the second operation unit. In other words, the operator can perform temporary automatic steering based on a criterion other than the preset driving criterion simply by operating the second operation unit. Therefore, there is no need to set an extra driving criterion again for temporary automatic steering, and the operator can easily handle the automatic steering function.

[0019] In the present invention, it is preferable that the first operating portion and the second operating portion are button-type switches indicated in different colors.

[0020] With this configuration, the first operating portion and the second operating portion are displayed in different colors, reducing the risk that the operator will press the wrong first operating portion or the second operating portion.

[0021] In the present invention, it is preferable that the switching operating device has a first indicating operating device that accepts manual operation for setting a starting point in teaching driving that pre-sets the driving standard to be used in the first automatic steering mode, and a second indicating operating device that accepts manual operation for setting an end point in the teaching driving.

[0022] According to this configuration, the start point and end point of the teaching travel can be set by operating the first and second indicating devices, and the first and second indicating devices are integrated into the switching device. Therefore, compared to a configuration in which the first and second indicating devices are not integrated into the switching device, it is easier for an operator or manager to remember the locations of the first and second indicating devices.

[0023] In the present invention, it is preferable that the switching operation device has a direction setting operation device that accepts manual operation for setting in advance the driving reference direction to be used in the first automatic steering mode.

[0024] With this configuration, an operator or manager can determine the driving reference by operating the direction control tool to set the direction of the driving reference in advance. Therefore, the operator or manager can easily set the driving reference without performing the teaching driving described above.

[0025] In the present invention, the first automatic steering mode includes a main mode in which the automatic steering is performed based on the predetermined driving criterion, and a secondary mode in which the automatic steering is performed based on the predetermined driving criterion or a secondary driving criterion that is automatically generated based on the driving criterion, and it is preferable that the switching operation device has a change operation device that accepts manual operation to switch between the main mode and the secondary mode.

[0026] With this configuration, different driving standards are newly generated based on the preset driving standards. This eliminates the need to run the aircraft to set new driving standards, making it easier to set multiple driving standards. In addition, the operator can select whether to use multiple driving standards by operating the change operation tool, so the operator can easily select various automatic steering methods. [Brief description of the drawings]

[0027] [Figure 1] FIG. [Diagram 2] FIG. 2 is a side view showing a steering operation device and a switching operation device arranged in the driving section of the combine harvester. [Diagram 3] 4 is a block diagram showing the input relationship between a switching operation tool and a control unit. FIG. [Figure 4] FIG. 4 is a diagram showing control modes in a steering control unit. [Diagram 5] FIG. 13 is a diagram showing how to set a main reference azimuth using a switching operation tool. [Figure 6] FIG. 13 is a diagram showing how to set a main reference azimuth using a switching operation tool. [Figure 7] 13 is a diagram showing a transition from a manual steering mode to a first automatic steering mode using a switching operation device. FIG. [Figure 8] 13 is a diagram showing a transition from the manual steering mode to the second automatic steering mode using a switching operation device. FIG. [Figure 9] 13 is a diagram showing how the display on the display device is switched to information about automatic steering using the screen switching button. [Figure 10] FIG. 13 is a diagram showing the display of a display device that displays information related to automatic steering. [Figure 11] FIG. 13 is a diagram showing the display of a display device that displays information related to automatic steering. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] An embodiment of the present invention will be described with reference to the drawings. In the following description, unless otherwise specified, the direction of the arrow F shown in Fig. 1 and Fig. 2 is "front" and the direction of the arrow B is "rear". The direction of the arrow L shown in Fig. 1 is "left" and the direction of the arrow R is "right". The direction of the arrow U shown in Fig. 2 is "up" and the direction of the arrow D is "down".

[0029] [Overall configuration of the combine] As shown in Fig. 1, a typical combine harvester 1, which is an example of a work vehicle, will be described. The machine body 10 of the combine harvester 1 is equipped with a crawler-type traveling device 11, a riding section 12, a threshing device 13, a grain tank 14, a harvesting section 15, a transport section 16, and a grain discharge device 18.

[0030] The traveling device 11 is driven by power from an engine (not shown). The traveling device 11 may be wheels. An operator (passenger) who operates or monitors the combine harvester 1 can ride on the riding section 12. The riding section 12 is provided with a seat 12A, and the operator can sit on the seat 12A. The operator may remotely operate the combine harvester 1 from outside the combine harvester 1.

[0031] The harvesting section 15 is provided at the front of the machine body 10. The transport section 16 is provided behind the harvesting section 15. The harvesting section 15 and the transport section 16 are configured to be able to rise and fall relative to the main body of the machine body 10 (the traveling device 11, the riding section 12, the threshing device 13, the grain tank 14, etc.) via a cylinder (not shown). In other words, the harvesting section 15 and the transport section 16 are configured to be able to rise and fall between a working position where they descend into the field and can harvest crops in the field, and a non-working position where they are separated above the field and cannot harvest crops in the field.

[0032] The harvesting section 15 harvests crops in the field. The combine 1 is capable of reaping travel, traveling on the traveling device 11 while reaping planted culms in the field with the harvesting section 15. Note that the "work travel" in this embodiment specifically refers to reaping travel. Note that the "work travel" may involve performing work other than reaping planted culms while traveling.

[0033] The reaped stalks harvested by the harvesting section 15 are transported to the rear of the machine body by the transport section 16. As a result, the reaped stalks are transported to the threshing device 13. The reaped stalks are threshed by the threshing device 13. The grains obtained by the threshing process are stored in the grain tank 14. The grains stored in the grain tank 14 are discharged outside the machine by the grain discharge device 18 as necessary. The threshing device 13, the grain tank 14, etc. may be included in the machine body 10.

[0034] 1 and 2, a display device 4 is disposed on the riding section 12. The display device 4 is, for example, a liquid crystal monitor or an organic LED monitor, and is configured to be capable of displaying various information. In this embodiment, the display device 4 is fixed to the riding section 12. However, the present invention is not limited to this, and the display device 4 may be configured to be detachable from the riding section 12, or the display device 4 may be located outside the combine harvester 1.

[0035] Here, the combine harvester 1 is configured to be capable of manual steering travel and automatic steering travel. Manual steering travel means that the travel is performed by manual steering by an operator. Automatic steering travel means that the travel is performed by automatic steering. Automatic steering means that the steering is performed automatically.

[0036] The automatic steering driving may or may not include large direction changes such as α-turns and U-turns. In addition, the automatic steering driving may or may not include reverse driving.

[0037] The riding section 12 is provided with a main speed change lever 40 and an auxiliary speed change switch 41 (see FIG. 3). The main speed change lever 40 is provided in the left side area of ​​the riding section 12. When the combine harvester 1 is running under manual steering or automatic steering, if the operator operates the main speed change lever 40, the speed of the combine harvester 1 changes. In other words, when the combine harvester 1 is running under manual steering or automatic steering, the operator can change the speed of the combine harvester 1 by operating the main speed change lever 40. The operator can operate the main speed change lever 40 to a forward operating position for moving the combine harvester 1 forward while changing its speed, a neutral position for stopping the combine harvester 1, and a reverse operating position for moving the combine harvester 1 backward while changing its speed.

[0038] The sub-speed change switch 41 is configured to be able to switch an unillustrated sub-speed change device (e.g., a multi-stage type speed change device) between a speed change state for traveling and a speed change state for working. The sub-speed change switch 41 is provided at the free end portion of the main speed change lever 40, but may be provided at a location other than the main speed change lever 40. The sub-speed change switch 41 may also be, for example, a lever-type operating device.

[0039] 1 and 2, the boarding section 12 is provided with a steering lever 42 and a switching operation device 43. The steering lever 42 is supported by a pillar at the right front of the boarding section 12. The steering lever 42 is adjacent to the front of the ascent door in the boarding section 12. In other words, the steering lever 42 is provided in the right area of ​​the boarding section 12. The switching operation device 43 is provided in the right area of ​​the boarding section 12 (the side where the steering lever 42 is located), and is provided above the steering lever 42. The steering lever 42 corresponds to the "steering operation device" of the present invention.

[0040] The steering lever 42 is a stick-type lever that swings back and forth and left and right, and accepts manual steering (artificial steering) by the operator. When the combine harvester 1 is traveling with manual steering, if the operator operates the steering lever 42 in the left and right direction, a speed difference is generated between the left and right crawlers of the traveling device 11. This causes the machine body 10 to turn. In other words, when the combine harvester 1 is traveling with manual steering, the operator can steer the machine body 10 by operating the steering lever 42.

[0041] In addition, when the operator operates the steering lever 42 in the forward / rearward direction of the machine body 10, the harvesting unit 15 and the transport unit 16 move up and down. When the operator operates the steering lever 42 in the forward direction, the harvesting unit 15 moves down to the working position, and when the operator operates the steering lever 42 in the rearward direction, the harvesting unit 15 moves up to the non-working position.

[0042] 3, the switching operation device 43 is provided with a first operation button 43A, a second operation button 43B, a first instruction operation button 43C, a second instruction operation button 43D, a direction setting operation button 43E, a change operation button 43F, a sensitivity switching button 43G, and a screen switching button 43H. In this embodiment, the switching operation device 43 is provided with eight push buttons. The first operation button 43A corresponds to the "first operation section" of the present invention, and the second operation button 43B corresponds to the "second operation section" of the present invention.

[0043] In this embodiment, the colors of the characters and figures on the first operation button 43A, the first instruction operation button 43C, the second instruction operation button 43D, the azimuth setting operation button 43E, and the change operation button 43F are the same and are green. The color of the characters and figures on the second operation button 43B is different from the color of the characters and figures on the first operation button 43A and is blue. In other words, the first operation button 43A and the second operation button 43B are button-type switches shown in different colors. The color of the characters and figures on the sensitivity switching button 43G and the screen switching button 43H is different from the color of the characters and figures on the first operation button 43A and the second operation button 43B and is white or gray. The first instruction operation button 43C corresponds to the "first instruction operation tool" of the present invention, and the second instruction operation button 43D corresponds to the "second instruction operation tool" of the present invention. The azimuth setting operation button 43E corresponds to the "azimuth setting operation tool" of the present invention. The change operation button 43F corresponds to the "change operation tool" of the present invention.

[0044] The combine harvester 1 is equipped with a satellite positioning device 80 shown in Fig. 2 and an inertial measurement device 81 shown in Fig. 3. The satellite positioning device 80 receives positioning signals from artificial satellites (not shown) used in GNSS (Global Satellite Navigation System, such as GPS, GLONASS, Galileo, QZSS, BeiDou, etc.). The inertial measurement device 81 is, for example, a gyro acceleration sensor or a magnetic direction sensor, and detects the angular velocity of the yaw angle of the body 10 of the combine harvester 1 and the acceleration in three mutually orthogonal axial directions over time. In other words, the inertial measurement device 81 complements the satellite navigation by the satellite positioning device 80. The inertial measurement device 81 may be incorporated in the satellite positioning device 80 or may be disposed in a location separate from the satellite positioning device 80.

[0045] [Configuration of the control unit] 3, the combine harvester 1 includes a control unit 20. The control unit 20 includes a detection unit 21, a vehicle position calculation unit 22, a vehicle orientation calculation unit 23, a display control unit 24, and a steering control unit 30. Each element of the control unit 20, such as the steering control unit 30, may be a physical device such as a microcomputer, a software module, or a combination of a device and software.

[0046] Although not shown, the control unit 20 includes a storage device. This storage device is preferably a non-volatile memory (e.g., a flash memory). The storage device temporarily or permanently stores data generated by each functional unit of the control unit 20.

[0047] A positioning signal from a satellite positioning device 80 and a detection result from an inertial measurement device 81 are input to the control unit 20. The positioning signal from the satellite positioning device 80 is sent to the vehicle position calculation unit 22. The detection result by the inertial measurement device 81 is sent to the vehicle orientation calculation unit 23.

[0048] Furthermore, the main speed change lever 40, the sub-speed change switch 41, the steering lever 42, the reaping / threshing clutch 44, and the harvest height sensor 45 are each configured to output a signal when operated, and each signal is input to the detection unit 21 of the control unit 20. In other words, the detection unit 21 detects the signals from the main speed change lever 40, the sub-speed change switch 41, the steering lever 42, the reaping / threshing clutch 44, and the harvest height sensor 45. These signals are sent from the detection unit 21 to the steering control unit 30.

[0049] The reaping / threshing clutch 44 is configured to be capable of transmitting power to each of the threshing device 13 and the harvesting section 15. The reaping / threshing clutch 44 is configured to be switchable between a power transmission state in which power is transmitted to the threshing device 13 and the harvesting section 15, and a power non-transmission state in which power is not transmitted to the threshing device 13 and the harvesting section 15.

[0050] The harvesting height sensor 45 detects the height of the harvesting section 15. For this reason, the harvesting height sensor 45 is configured to be able to detect a state in which the harvesting section 15 is located at the working position or the non-working position.

[0051] The vehicle position calculation unit 22 calculates the position coordinates of the machine 10 over time based on the positioning data output by the satellite positioning device 80. In this way, the vehicle position calculation unit 22 acquires the position coordinates of the machine 10.

[0052] The vehicle orientation calculation unit 23 receives the position coordinates of the machine body 10 from the vehicle position calculation unit 22. The vehicle orientation calculation unit 23 then calculates the attitude orientation of the machine body 10 based on the detection results by the inertial measurement unit 81 and the position coordinates of the machine body 10. The attitude orientation of the machine body 10 is the orientation in which the machine body 10 moves forward or backward when the speed difference between the left and right crawlers of the traveling device 11 is zero or approximately zero.

[0053] More specifically, first, while the vehicle 10 is traveling, the vehicle orientation calculation unit 23 calculates an initial attitude and orientation based on the current position coordinates of the vehicle 10 and the position coordinates of the vehicle 10 at the point where the vehicle 10 was traveling immediately before. Next, when the vehicle 10 travels for a certain period of time after the initial attitude and orientation are calculated, the vehicle orientation calculation unit 23 calculates the amount of change in orientation by integrating the angular velocity detected by the inertial measurement unit 81 during the certain period of traveling.

[0054] Then, the vehicle orientation calculation unit 23 updates the calculated orientation by adding the amount of change in the orientation thus calculated to the initial attitude orientation. After that, the amount of change in the attitude orientation is similarly calculated at regular time intervals, and the calculated attitude orientation is updated sequentially. With the above configuration, the vehicle orientation calculation unit 23 calculates the orientation of the aircraft 10.

[0055] The display control unit 24 controls the display device 4 so that the display device 4 displays various screens according to the state of the combine harvester 1. In this embodiment, the display control unit 24 is configured to be able to control switching of the screens displayed on the display device 4 based on the control mode of the steering control unit 30 and an operation signal from the switching operation device 43.

[0056] The steering control unit 30 is configured to be capable of performing automatic steering for controlling the traveling device 11 to automatically travel the vehicle 10 along an automatic steering target line GL described below. As shown in Fig. 4, the steering control unit 30 has a plurality of control modes for steering control of the traveling device 11. This control mode can be switched between a plurality of modes including a manual steering mode in which automatic steering is not performed, and an automatic steering mode in which automatic steering can be performed.

[0057] Furthermore, as shown in Fig. 4, there are two types of automatic steering modes, a first automatic steering mode and a second automatic steering mode. In this embodiment, the multiple types of automatic steering modes include the first automatic steering mode and the second automatic steering mode.

[0058] When the control mode of the steering control unit 30 is the manual steering mode, a control signal corresponding to the operation of the steering lever 42 is input to the steering control unit 30. The steering control unit 30 controls the traveling device 11 in response to this manual steering control signal, thereby controlling the traveling of the machine body 10. As a result, when the control mode of the steering control unit 30 is the manual steering mode, the combine harvester 1 performs manual steering traveling.

[0059] When the control mode of the steering control unit 30 is the first automatic steering mode or the second automatic steering mode, the steering control unit 30 controls the traveling device 11 so that the combine 1 performs automatic steering traveling based on the automatic steering control signal. The first automatic steering mode is a control mode in which automatic steering is performed based on a preset main reference direction TA1. The second automatic steering mode is a control mode in which automatic steering is performed based on the reference direction TB immediately after the reference direction TB is determined by traveling straight ahead with manual steering. The main reference direction TA1 and the reference direction TB correspond to the "traveling reference" of the present invention. In addition, the auxiliary reference direction TA2 and the automatic steering target line GL described later also correspond to the "traveling reference" of the present invention. Note that "straight running" also includes a traveling mode in which the combine 1 travels approximately straight ahead.

[0060] The control mode of the steering control unit 30 is initially set to the manual steering mode when the engine of the combine harvester 1 is started or the power is turned on. Also, the control mode of the steering control unit 30 may be initially set to the first automatic steering mode or the second automatic steering mode when the engine of the combine harvester 1 is started or the power is turned on.

[0061] As shown in FIG. 3, the steering control unit 30 includes a mode switching unit 31, a straight-line determination unit 32, a direction determination unit 33, a route generation unit 34, and a driving control unit 35.

[0062] The mode switching unit 31 is configured to be able to switch the control mode of the steering control unit 30. The mode switching unit 31 switches the control mode of the steering control unit 30 based on an operation signal from the switching operation device 43 and the state of the harvesting unit 15. The switching operation device 43 accepts a manual operation (human operation) for switching the control mode of the steering control unit 30. The first operation button 43A accepts a manual operation for switching the control mode of the steering control unit 30 to the first automatic steering mode. The second operation button 43B accepts a manual operation for switching the control mode of the steering control unit 30 to the second automatic steering mode.

[0063] The straight-line determination unit 32 determines whether the aircraft 10 has traveled straight in the same direction for a predetermined distance.

[0064] The orientation determination unit 33 determines the main reference orientation TA1 for performing automatic steering when the steering control unit 30 is in the first automatic steering mode. Also, the orientation determination unit 33 determines the reference orientation TB for performing automatic steering when the steering control unit 30 is in the second automatic steering mode. The path generation unit 34 generates an automatic steering target line GL that extends in a straight line along the determined driving reference (main reference orientation TA1, reference orientation TB, etc.). The automatic steering target line GL is a path that serves as a reference for performing automatic steering. The traveling control unit 35 is configured to be able to control the traveling device 11 so that it travels straight along the automatic steering target line GL. The traveling control unit 35 controls the traveling device 11 to control the traveling of the vehicle 10.

[0065] [Method of determining the reference direction] In this embodiment, when the vehicle 10 travels straight in the same direction for a predetermined distance under manual steering, the orientation determination unit 33 is configured to be able to determine the main reference orientation TA1. The main reference orientation TA1 is an orientation that serves as a reference for automatic steering. The vehicle 10 travels straight in the same direction for a predetermined distance to set the main reference orientation TA1 is referred to as "teaching travel."

[0066] The teaching travel in this embodiment will be described with reference to Fig. 5. When the operator presses the first instruction operation button 43C, the position of the vehicle 10 at the time of operation of the first instruction operation button 43C is registered as a first point Y1. The first point Y1 is the starting point of the teaching travel. In other words, the first instruction operation button 43C accepts a manual operation for setting the first point Y1 in the teaching travel in which the main reference heading TA1 used in the first automatic steering mode is set in advance.

[0067] In order to prevent an erroneous operation by the operator, when the operator presses the first instruction operation button 43C for a long time, for example, for one second, the position of the aircraft 10 at the start of the long press or at the time when one second has elapsed may be registered as the first point Y1. When the first point Y1 is registered, the lamp 43c (see FIG. 3) of the first instruction operation button 43C is turned on.

[0068] After the first point Y1 is registered, the operator manually drives the vehicle 10 in a straight line (or approximately straight line) from the first point Y1. At this time, the straight line determination unit 32 shown in FIG. 3 determines whether the vehicle 10 has driven in a straight line in the same direction over a predetermined distance D1 in the manual steering mode. In detail, a signal indicating the operation state of the steering lever 42 is sent from the steering lever 42 via the detection unit 21 to the steering control unit 30. Based on this signal, the straight line determination unit 32 determines over time whether the steering lever 42 is being operated in the left or right direction. The predetermined distance D1 is not particularly limited, but may be, for example, 1 meter.

[0069] In addition, the position coordinates of the vehicle 10 are sent from the vehicle position calculation unit 22 to the steering control unit 30. Then, the straight-line determination unit 32 calculates the movement distance of the vehicle 10 while the steering lever 42 is not being operated, based on the position coordinates of the vehicle 10 received from the vehicle position calculation unit 22. If the calculated movement distance reaches a predetermined distance D1, the straight-line determination unit 32 determines that the vehicle 10 has moved straight in the same direction for the predetermined distance D1. In addition, if the calculated movement distance does not reach the predetermined distance D1, the straight-line determination unit 32 determines that the vehicle 10 has not moved straight for the predetermined distance D1.

[0070] When the operator presses the second instruction operation button 43D after the straight-line determination unit 32 has determined that the machine 10 has traveled straight in the same direction over the predetermined distance D1, the position of the machine 10 at the time of operating the second instruction operation button 43D is registered as the second point Y2. The second point Y2 is the end point of the teaching travel. In other words, the second instruction operation button 43D accepts a manual operation for setting the second point Y2 in the teaching travel.

[0071] In order to prevent an erroneous operation by the operator, when the operator presses the second instruction operation button 43D for a long time, for example, for one second, the position of the aircraft 10 at the start of the long press or at the end of one second may be registered as the second point Y2. When the second point Y2 is registered, the lamp 43d (see FIG. 3) of the second instruction operation button 43D lights up. In addition, when the operator presses the second instruction operation button 43D in a state where the first point Y1 has not been set, neither the first point Y1 nor the second point Y2 is set.

[0072] Then, the orientation determining unit 33 determines the main reference orientation TA1 based on the direction of the line connecting the first point Y1 and the second point Y2.

[0073] In addition, when the operator presses at least one of the first instruction operation button 43C and the second instruction operation button 43D for a long time, for example, for one second, in a state in which the main reference azimuth TA1 is determined based on the direction of the line connecting the first point Y1 and the second point Y2, the setting of the main reference azimuth TA1 is cancelled. At this time, the lamps 43c and 43d are turned off.

[0074] In this way, lamps 43c, 43d are turned on when the main reference orientation TA1 has been determined based on the direction of the line connecting the first point Y1 and the second point Y2, and are turned off when the main reference orientation TA1 has not been determined based on the direction of the line connecting the first point Y1 and the second point Y2.

[0075] The main reference azimuth TA1 can also be set by the method shown in Fig. 6. When the operator presses the azimuth setting operation button 43E of the switching operation device 43, the display control unit 24 controls the display device 4 to display the azimuth setting screen 52 based on the operation signal from the azimuth setting operation button 43E. That is, the azimuth setting operation button 43E accepts a manual operation for setting in advance the azimuth of the main reference azimuth TA1 used in the first automatic steering mode. The azimuth setting screen 52 is configured to be able to be displayed by the operator operating a button (not shown, for example, a cross button) provided on the display device 4.

[0076] The azimuth setting screen 52 displayed on the display device 4 is a screen for setting a numerical value within a range of 0 to 360 degrees clockwise, with true north being 0 degrees. The operator can manually set a numerical value within a range of 0 to 360 degrees. When the operator completes this setting, the azimuth determination unit 33 determines the main reference azimuth TA1 based on the numerical value set by the operator within a range of 0 to 360 degrees. At this time, the lamp 43e (see FIG. 3) of the azimuth setting operation button 43E lights up.

[0077] Lamp 43e lights up when the main reference orientation TA1 has been determined based on the numerical value set by the operator on the orientation setting screen 52, and turns off when the main reference orientation TA1 has not been determined based on the numerical value set by the operator on the orientation setting screen 52.

[0078] The orientation setting screen 52 is not limited to a configuration in which true north is displayed as 0 degrees, and may be configured to display any of east, west, north, south, etc. as 0 degrees. The orientation setting screen 52 may also be configured to set a range of 0 to 360 degrees counterclockwise.

[0079] In this way, the main reference orientation TA1 can be set by the operator operating the first instruction operation button 43C and the second instruction operation button 43D, or can be set by the operator setting a numerical value for the orientation displayed on the orientation setting screen 52. The control mode of the steering control unit 30 when the main reference orientation TA1 is set may be a manual steering mode or an automatic steering mode.

[0080] As described above, the control unit 20 includes a storage device (not shown). When the main reference orientation TA1 is determined, the main reference orientation TA1 is stored in the storage device. The storage device may be configured to temporarily store the main reference orientation TA1, or may be configured to permanently store the main reference orientation TA1.

[0081] When the direction determination unit 33 determines the main reference direction TA1, it also sets the secondary reference direction TA2 as shown in FIG. 5. The secondary reference direction TA2 faces a direction shifted by 90 degrees from the main reference direction TA1. In other words, the secondary reference direction TA2 is automatically set to face a direction shifted by 90 degrees from the main reference direction TA1. Although details will be described later, the first automatic steering mode of this embodiment includes a main mode and a secondary mode as shown in FIG. 4, and the secondary reference direction TA2 is used in the secondary mode. Note that the direction determination unit 33 may be configured to set the secondary reference direction TA2 when the control mode of the steering control unit 30 is switched to the secondary mode. The set secondary reference direction TA2 is stored in a storage device (not shown). The secondary reference direction TA2 corresponds to the "secondary driving reference" of the present invention.

[0082] [About the first automatic steering mode] The first automatic steering mode will be described with reference to Figs. 3, 4 and 7. The first operation button 43A accepts a manual operation for switching the control mode of the steering control unit 30 to the first automatic steering mode. The operation of pressing the first operation button 43A is shown as "operation #01" in Figs. 4 and 7. When operation #01 is performed, the mode switching unit 31 switches the control mode of the steering control unit 30 from the manual steering mode to the first automatic steering mode. At this time, the lamp 43a (see Fig. 3) of the first operation button 43A lights up.

[0083] As shown in Fig. 4, the first automatic steering mode has a preparation state and an automatic steering state. The preparation state is a state in which preparations are made for starting automatic steering, and manual steering by the operator continues in this preparation state. The automatic steering state is a state in which automatic steering is actually being performed. At the timing when the control mode of the steering control unit 30 is switched from the manual steering mode to the first automatic steering mode, the vehicle first transitions to the preparation state for the first automatic steering mode. In other words, the first automatic steering mode starts from the preparation state.

[0084] When operation #01 is performed while the control mode of the steering control unit 30 is the first automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 from the first automatic steering mode to the manual steering mode, as shown in Fig. 4. In addition, when operation #01 is performed while the control mode of the steering control unit 30 is the second automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 to the first automatic steering mode, as shown in Fig. 4. In this case as well, the first automatic steering mode starts from the preparation state.

[0085] Furthermore, when the first automatic steering mode is in a ready state and the main reference heading TA1 has not been set (determined), a guidance screen may be displayed on the display device 4 to prompt the operator to set (determine) the main reference heading TA1.

[0086] 7 shows a state in which operation #01 is performed at point P1 and the control mode of the steering control unit 30 is switched from the manual steering mode to the first automatic steering mode. From point P1, the system transitions to a preparation state for the first automatic steering mode.

[0087] When the first automatic steering mode is in the preparation state, the steering control unit 30 judges whether the condition #01 or the condition #02 for transitioning to the automatic steering state is satisfied. At the same time, the display control unit 24 causes the display device 4 to display a guidance screen that prompts the operator to perform an operation for transitioning to the automatic steering state. At this time, the operator manually operates the combine 1 to prepare the conditions for transitioning to the automatic steering state. That is, based on the preparation state of the first automatic steering mode, the operator performs manual steering to align the azimuth attitude of the machine body 10 with the main reference azimuth TA1 or the secondary reference azimuth TA2. FIG. 7 shows a state in which the machine body 10 is traveling between points P1 and P3 based on manual steering when the first automatic steering mode is in the preparation state.

[0088] The condition #01 and the condition #02 for the first automatic steering mode to transition from the preparation state to the automatic steering state include the following condition items No. 1 to No. 5.

[0089] Condition item No. 1: A state in which the machine body 10 is moving forward based on the calculation result of the vehicle position calculation unit 22. Condition item No. 2: The state of the main shift lever 40 provided in the riding section 12 is set to the forward operating position described above. Condition item No. 3: The auxiliary transmission switch 41 is in the above-mentioned work transmission state (the auxiliary transmission device (not shown) is in the work transmission state). Condition item No. 4: The clutch for transmitting power to the harvesting unit 15 is in a power transmitting state. Condition item No. 5: The harvesting part 15 is lowered to the above-mentioned working position.

[0090] The first automatic steering mode of this embodiment includes a main mode and a sub-mode. The main mode is a mode in which automatic steering is performed based on a preset main reference azimuth TA1. The sub-mode is a mode in which automatic steering is performed based on the main reference azimuth TA1 or a sub-reference azimuth TA2 that is automatically generated based on the main reference azimuth TA1.

[0091] The switching operation device 43 has a change operation button 43F. The change operation button 43F accepts a manual operation for switching between the main mode and the sub mode. The operation of pressing the change operation button 43F is shown as "operation #03" in FIG. 4. That is, each time operation #03 is performed, the main mode and the sub mode are alternately switched. Note that operation #03 can also be accepted in the manual steering mode. A lamp 43f (see FIG. 3) of the change operation button 43F is lit when the control mode of the steering control unit 30 is set to the sub mode, and is turned off when the control mode of the steering control unit 30 is set to the main mode.

[0092] When the control mode of the steering control unit 30 is set to the main mode, the main reference heading TA1 is used for automatic steering in the first automatic steering mode. The condition #01 for the first automatic steering mode to transition to an automatic steering state includes the following condition item No. 6.

[0093] Condition item No. 6: The difference between the attitude direction of the aircraft 10 calculated by the vehicle direction calculation unit 23 and the main reference direction TA1 is within a preset angle (for example, 3 degrees).

[0094] That is, in this embodiment, condition #01 for the first automatic steering mode to transition to the automatic steering state is that all of condition items No. 1 to No. 6 are satisfied.

[0095] When the control mode of the steering control unit 30 is set to the secondary mode, one of the main reference azimuth TA1 and the secondary reference azimuth TA2 is used for automatic steering in the first automatic steering mode. In the secondary mode, the steering control unit 30 selects, from the main reference azimuth TA1 and the secondary reference azimuth TA2, the one that has a smaller azimuth deviation from the attitude azimuth of the aircraft 10 calculated by the host vehicle azimuth calculation unit 23.

[0096] That is, in the primary mode, only the primary reference azimuth TA1 is selected, and in the secondary mode, one of the primary reference azimuth TA1 and the secondary reference azimuth TA2, which has the smaller azimuth deviation from the attitude azimuth of the aircraft 10, is selected.

[0097] When the control mode of the steering control section 30 is set to the sub mode, the condition #02 for the first automatic steering mode to transition to the automatic steering state includes the following condition item No. 7.

[0098] Condition item No. 7: The difference between the attitude direction of the aircraft 10 calculated by the vehicle direction calculation unit 23 and a selected one of the main reference direction TA1 and the secondary reference direction TA2 is within a preset angle (for example, 3 degrees).

[0099] That is, in this embodiment, the condition #02 for the first automatic steering mode to transition to the automatic steering state is that all of the condition items Nos. 1 to 5 and 7 are satisfied.

[0100] When the first autosteering mode is in a ready state and condition #01 or condition #02 is satisfied, switching to the autosteering state is possible. If the vehicle 10 travels a predetermined distance D2 in this state, the path generating unit 34 generates the autosteering target line GL, and the first autosteering mode transitions from the ready state to the autosteering state.

[0101] 7 shows a state in which condition #01 or condition #02 is satisfied at point P3, and the machine 10 travels a predetermined distance D2 between point P3 and point P4. The predetermined distance D2 is not particularly limited, and may be, for example, 1 meter.

[0102] When the first automatic steering mode transitions to the automatic steering state, the path generating unit 34 generates an automatic steering target line GL, as shown in Fig. 7. The automatic steering target line GL passes through a specific reference point K on the aircraft 10 in a planar view and extends in a direction along a selected one of the main reference orientation TA1 and the secondary reference orientation TA2. Then, information indicating the automatic steering target line GL is sent from the path generating unit 34 to the cruise control unit 35.

[0103] When the control mode of the steering control unit 30 is the first automatic steering mode and the first automatic steering mode is in an automatic steering state, the travel control unit 35 controls the travel of the combine harvester 1 based on the position coordinates of the machine body 10 received from the vehicle position calculation unit 22, the attitude direction of the machine body 10 received from the vehicle direction calculation unit 23, and information indicating the automatic steering target line GL received from the route generation unit 34. More specifically, the travel control unit 35 controls the travel of the machine body 10 so that the harvesting travel is performed by automatic steering travel along the automatic steering target line GL. At this time, the travel control unit 35 controls the travel of the machine body 10 so that, for example, the reference point K is located on the automatic steering target line GL. At this time, if the operator fine-tunes the main speed change lever 40 within the range of the forward operation position described above, the vehicle speed of the combine harvester 1 changes while the automatic steering continues.

[0104] In this manner, the steering control unit 30 performs automatic steering so as to automatically travel along the selected one of the primary reference heading TA1 and the secondary reference heading TA2.

[0105] A method for canceling the automatic steering state will now be described. When the detection unit 21 detects "State #01" shown in Fig. 4 while automatic steering is being performed, the steering control unit 30 ends the automatic steering. "Status #01" is a status related to the stop of work. That is, the detection unit 21 detects the stop of work. Status #01 includes the following status items No. 1 to No. 6.

[0106] Status item No. 1: The main shift lever 40 is operated to an operating position other than the forward operating position. Status item No. 2: The auxiliary transmission switch 41 is no longer in the work speed change state (the auxiliary transmission device (not shown) is no longer in the work speed change state). Status item No. 3: The reaping and threshing clutch 44 is in a non-power transmitting state to the harvesting section 15. Status item No. 4: The harvesting section 15 moves to a non-working position (the non-working position is detected by the harvesting height sensor 45). Status item No. 5: An operation is performed to move the harvesting unit 15 to a non-working position (the steering lever 42 is operated rearward). Status item No. 6: The steering lever 42 is operated in the left / right direction beyond a preset operation amount.

[0107] That is, state #01 means that any one of state items No. 1 to 6 is detected by the detection unit 21. In other words, state #01 means that the operator performs any one of state items No. 1 to 6. When state #01 is detected by the detection unit 21, automatic steering is released, and the first automatic steering mode transitions from the automatic steering state to the preparation state. That is, when the detection unit 21 detects the stop of work while automatic steering based on the first automatic steering mode is being performed, the steering control unit 30 ends the automatic steering while maintaining the control mode in the first automatic steering mode. At this time, the lamp 43a of the first operation button 43A remains lit.

[0108] For this reason, for example, if an operator performs an operation corresponding to state #01 at the edge of a field to temporarily stop automatic steering, then turns the machine 10 by 90 degrees or 180 degrees and travels along the selected one of the main reference heading TA1 and the secondary reference heading TA2, it becomes possible to satisfy the above-mentioned condition #01 or condition #02. As a result, automatic steering is resumed as it is with only a temporary stop of automatic steering.

[0109] In this way, the detection unit 21 is configured to detect the stop of work in response to the satisfaction of a predetermined stop condition. The stop condition includes at least one of the following: the main speed change lever 40 is operated to an operating position other than the forward operating position, the sub-speed change device (not shown) is no longer in the working speed change state, the reaping and threshing clutch 44 for transmitting power to the harvesting unit 15 is in a power non-transmitting state, the harvesting unit 15 moves to a non-working position, an operation is performed to move the harvesting unit 15 to a non-working position, and the steering lever 42 is operated.

[0110] Furthermore, when the operator presses the first operation button 43A (operation #01) while the steering control unit 30 is performing automatic steering in the first automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 from the first automatic steering mode to the manual steering mode, as shown in Fig. 4, and the automatic steering of the steering control unit 30 ends. In other words, when the first operation button 43A of the switching operation device 43 is operated while automatic steering based on the first automatic steering mode is being performed, the steering control unit 30 ends the automatic steering, and the control mode switches to the manual steering mode. At this time, the lamp 43a of the first operation button 43A is turned off.

[0111] The lamp 43a is turned on when the control mode of the steering control unit 30 is the first automatic steering mode, and is turned off when the control mode of the steering control unit 30 is not the first automatic steering mode.

[0112] When automatic steering is released, the steering amount output from the steering control unit 30 to the traveling device 11 becomes zero, and the speed difference between the left and right crawlers of the traveling device 11 becomes zero or approximately zero. This causes the traveling device 11 to always travel straight. In other words, the steering control unit 30 controls the traveling device 11 to travel straight when automatic steering ends.

[0113] In this way, the automatic steering based on the first automatic steering mode is particularly easy to use when the field is rectangular. When the combine harvester 1 performs reap travel while traveling back and forth inside the field, the straight-line direction during reap travel is consistent, so even if the operator is a beginner, the operator can easily make the machine body 10 travel straight (or approximately straight) during reap travel. Also, when the combine harvester 1 performs middle-cut travel in the field (reap travel while moving forward with unharvested crops on both the left and right sides of the combine harvester 1), even if the front is covered with crops and the operator has difficulty in seeing the front of the machine body 10, the automatic steering based on the first automatic steering mode allows the machine body 10 to travel accurately along the automatic steering target line GL.

[0114] [About the second automatic steering mode] The second automatic steering mode will be described with reference to Figs. 3, 4 and 8. As described above, the second automatic steering mode is a control mode in which automatic steering is performed based on the reference heading TB immediately after the reference heading TB is determined by driving straight ahead with manual steering. Therefore, even if the main reference heading TA1 is not set in advance, automatic steering based on the second automatic steering mode is possible. Also, even if the main reference heading TA1 is set in advance, automatic steering is possible based on a reference heading TB different from the main reference heading TA1 without erasing the stored main reference heading TA1.

[0115] The second operation button 43B accepts a manual operation for switching the control mode of the steering control unit 30 to the second automatic steering mode. The operation of pressing the second operation button 43B is shown as "operation #02" in Fig. 4 and Fig. 8. Fig. 8 shows a state in which operation #02 is performed at point P5 and the control mode of the steering control unit 30 is switched from the manual steering mode to the second automatic steering mode. From point P5, the mode transitions to a preparation state for the second automatic steering mode. In other words, when operation #02 is performed, the mode switching unit 31 switches the control mode of the steering control unit 30 from the manual steering mode to the second automatic steering mode. At this time, the lamp 43b (see Fig. 3) of the second operation button 43B is turned on.

[0116] As shown in Fig. 4, like the first automatic steering mode, the second automatic steering mode has a preparation state and an automatic steering state. The preparation state is a state in which preparations are made for starting automatic steering, and manual steering by the operator continues in this preparation state. The automatic steering state is a state in which automatic steering is actually being performed. At the timing when the control mode of the steering control unit 30 is switched from the manual steering mode to the second automatic steering mode, the vehicle first transitions to a preparation state for the second automatic steering mode. In other words, the second automatic steering mode starts from the preparation state.

[0117] When the second automatic steering mode is in the preparation state, the steering control unit 30 judges whether the condition #03 for transitioning to the automatic steering state is satisfied. At the same time, the display control unit 24 causes the display device 4 to display a guidance screen that prompts the operator to perform an operation for transitioning to the automatic steering state. At this time, the operator manually operates the combine 1 to prepare the conditions for transitioning to the automatic steering state.

[0118] When operation #02 is performed while the control mode of the steering control unit 30 is in the second automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 from the second automatic steering mode to the manual steering mode, as shown in Fig. 4. When operation #02 is performed while the control mode of the steering control unit 30 is in the first automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 to the second automatic steering mode, as shown in Fig. 4. In this case as well, the second automatic steering mode starts from the preparation state.

[0119] Condition #03 for switching the second automatic steering mode from the preparation state to the automatic steering state includes the following condition item No. 8 in addition to the above-mentioned condition items No. 1 to No. 5.

[0120] Condition item No. 8: The straight-line determination unit 32 has determined that the aircraft 10 has traveled straight in the same direction for a predetermined distance D3.

[0121] That is, in this embodiment, condition #03 for the second automatic steering mode to transition from the preparation state to the automatic steering state is to satisfy all of condition items Nos. 1 to 5 and 8. The predetermined distance D3 is not particularly limited, but may be, for example, 1 meter.

[0122] When the second automatic steering mode is in a preparation state, the orientation determination unit 33 stores the transition of the position coordinates of the vehicle 10 while the steering lever 42 is not operated in the left or right direction, based on the position coordinates of the vehicle 10 received from the vehicle position calculation unit 22. Then, when the straight-line determination unit 32 determines that the vehicle 10 has traveled straight in the same direction over a predetermined distance D3, the orientation determination unit 33 determines two points among the stored position coordinates as a first point Y3 and a second point Y4.

[0123] At this time, the direction determination unit 33 determines the position coordinates of the aircraft 10 at the time when the straight-line determination unit 32 determines that the aircraft 10 has traveled straight in the same direction over the predetermined distance D3 as the second point Y4. The direction determination unit 33 also determines the position coordinates of the aircraft 10 at the start of the straight-line travel over the predetermined distance D3 as the first point Y3.

[0124] In other words, the start point and end point of the straight line traveled over the predetermined distance D3 are determined as the first point Y3 and the second point Y4, respectively.

[0125] Then, the orientation determination unit 33 determines a reference orientation TB for automatic steering based on the first point Y3 and the second point Y4.

[0126] More specifically, the orientation determination unit 33 calculates the direction of a straight line from the first point Y3 to the second point Y4. Here, the direction of the straight line from the first point Y3 to the second point Y4 is equal to the direction of straight travel over the predetermined distance D3. That is, the orientation determination unit 33 calculates the direction of straight travel over the predetermined distance D3. Then, the orientation determination unit 33 determines the calculated direction as the reference orientation TB.

[0127] 8 shows a state in which condition #03 is satisfied at the second point Y4, and the vehicle 10 travels a predetermined distance D3 between the first point Y3 and the second point Y4. When the second autosteer mode is in a preparation state and condition #03 for switching to the second autosteer mode is satisfied, the path generating unit 34 generates the autosteer target line GL, and the second autosteer mode transitions from the preparation state to the autosteer state.

[0128] At this time, the path generating unit 34 generates an automatic steering target line GL so as to pass through a specific reference point K on the vehicle 10 in a planar view and extend in a direction along the reference orientation TB, as shown in Fig. 8. Then, information indicating the automatic steering target line GL is sent from the steering control unit 30 to the traveling control unit 35. In other words, the steering control unit 30 executes automatic steering so as to automatically travel straight along the reference orientation TB.

[0129] The control mode of the travel control unit 35 when the control mode of the steering control unit 30 is the second automatic steering mode is the same as the control mode of the travel control unit 35 when the control mode of the steering control unit 30 is the first automatic steering mode. In other words, the travel control unit 35 controls the travel of the combine 1 based on the position coordinates of the machine body 10 received from the vehicle position calculation unit 22, the attitude orientation of the machine body 10 received from the vehicle orientation calculation unit 23, and information indicating the automatic steering target line GL received from the steering control unit 30.

[0130] A method for canceling the second automatic steering mode will be described. When "state #01" shown in Fig. 4 is detected by the detection unit 21 while automatic steering is being performed, the steering control unit 30 ends the automatic steering. "State #01" is a state related to the stop of work, and any of the above-mentioned state items No. 1 to 6 is detected by the detection unit 21. In other words, state #01 is the operator performing any of the operations of state items No. 1 to 6. That is, the detection unit 21 detects the stop of work.

[0131] When state #01 is detected by the detection unit 21, automatic steering is released and the second automatic steering mode transitions from the automatic steering state to the preparation state. In other words, when the detection unit 21 detects the stop of work while automatic steering based on the second automatic steering mode is being performed, the steering control unit 30 ends the automatic steering while maintaining the control mode in the second automatic steering mode. At this time, the lamp 43b of the second operation button 43B remains lit.

[0132] For this reason, for example, if the operator performs an operation corresponding to state #01 at the edge of a farm field to temporarily stop automatic steering, then turns the machine 10 and drives it straight ahead, it is possible to satisfy condition #03 described above. As a result, automatic steering is resumed after only a temporary stop of the automatic steering.

[0133] Furthermore, when the operator presses the second operation button 43B (operation #02) while the steering control unit 30 is performing automatic steering in the second automatic steering mode, the mode switching unit 31 switches the control mode of the steering control unit 30 from the second automatic steering mode to the manual steering mode, as shown in Fig. 4, and the automatic steering by the steering control unit 30 ends. In other words, when the second operation button 43B of the switching operation device 43 is operated while automatic steering based on the second automatic steering mode is being performed, the steering control unit 30 ends the automatic steering, and the control mode switches to the manual steering mode. At this time, the lamp 43b of the second operation button 43B is turned off.

[0134] The lamp 43b is turned on when the control mode of the steering control unit 30 is the second automatic steering mode, and is turned off when the control mode of the steering control unit 30 is not the second automatic steering mode.

[0135] When automatic steering is released, the steering amount output from the steering control unit 30 to the traveling device 11 becomes zero, and the speed difference between the left and right crawlers of the traveling device 11 becomes zero or approximately zero. This causes the traveling device 11 to always travel straight. In other words, the steering control unit 30 controls the traveling device 11 to travel straight when automatic steering ends.

[0136] In this way, in the second automatic steering mode, even if a reference direction such as the main reference direction TA1 is not set in advance, the reference direction TB is determined when the vehicle travels straight ahead on the spot, enabling automatic steering. For this reason, the second automatic steering mode enables easier automatic steering than the first automatic steering mode.

[0137] The second automatic steering mode is easy to use in, for example, a triangular field or a polygonal field having pentagons or more sides. Also, the operator can use the first automatic steering mode in the in-between traveling described above in the description of the first automatic steering mode, and can use the second automatic steering mode in traveling other than the in-between traveling. In this way, in this embodiment, the operator can use the first automatic steering mode and the second automatic steering mode selectively.

[0138] In the second automatic steering mode, one reference direction TB is set, but the reference direction TB and another reference direction perpendicular to the reference direction TB may be set. For example, if a 90-degree turn is expected after automatic steering is performed along the reference direction TB, the reference direction TB and the other reference direction may be set. With this configuration, after automatic steering is performed along the reference direction TB, the operator can easily turn the aircraft 10 by 90 degrees and then align the attitude direction of the aircraft 10 to a direction perpendicular to the reference direction TB, and can easily resume automatic steering based on the second automatic steering mode along the other reference direction.

[0139] [About the automatic steering screen] 9, the display control unit 24 can control the display device 4 to selectively display a plurality of screens including a status screen 50 and a guidance screen 51 for displaying information related to automatic steering. The switching operation device 43 in this embodiment has a screen switching button 43H, and the screen switching button 43H accepts a manual operation for switching the display of the display device 4 to the guidance screen 51. When the operator presses the screen switching button 43H while the status screen 50 is displayed on the display device 4, the display of the display device 4 switches to the guidance screen 51.

[0140] Incidentally, when the operator presses the screen switching button 43H while the guidance screen 51 is displayed on the display device 4, the display on the display device 4 may be switched to the status screen 50. In other words, the display on the display device 4 may be switched alternately between the status screen 50 and the guidance screen 51 every time the operator presses the screen switching button 43H. In this case, a lamp 43h (see FIG. 3) provided on the screen switching button 43H may be linked to the display and non-display of the guidance screen 51. Also, the guidance screen 51 is configured to be able to be displayed by the operator operating a button (not shown, for example, a cross button) provided on the display device 4.

[0141] On the entire screen of the status screen 50, information such as the vehicle speed of the combine 1, the engine RPM, the position of the harvesting section 15 (working position or non-working position), the remaining amount of fuel and / or urea water, the opening degree of the chaff sieve (not shown), the amount of storage in the grain tank 14, etc. is displayed. In other words, the status screen 50 displays information related to travel and work on the entire screen.

[0142] Also, a mode display section 50A is present in the central left-right portion at the top of the status screen 50. The current control mode of the steering control section 30 is displayed in the mode display section 50A. That is, one of the manual steering mode, the first automatic steering mode, and the second automatic steering mode is displayed in the mode display section 50A according to the current control mode.

[0143] The guidance screen 51 has two regions divided into upper and lower parts. A status display region 51A is displayed in the lower region of the guidance screen 51. The status display region 51A displays information on the speed of the combine 1, the engine RPM, the position of the harvesting section 15, the remaining amount of fuel, the opening degree of the chaff sieve, the storage amount of the grain tank 14, and the like, similar to what is displayed on the guidance screen 51. An automatic steering region 51B is displayed in the upper region of the guidance screen 51. Information on automatic steering is displayed in the automatic steering region 51B. That is, the display control unit 24 displays information on traveling and work in the lower status display region 51A of the guidance screen 51, which divides the entire screen into two, and displays information on automatic steering in the automatic steering region 51B.

[0144] The automatic steering area 51B is displayed in the upper region of the guidance screen 51. For this reason, compared to a configuration in which the automatic steering area 51B is displayed in the lower region of the guidance screen 51, it is easier for the operator to notice the automatic steering area 51B.

[0145] Furthermore, a mode display section 51C is present in the upper left portion of the automatic steering area 51B. The mode display section 51C displays the same information as that displayed in the mode display section 50A.

[0146] In addition, a field condition display section 51D is present in the upper right part of the automatic steering area 51B. The field condition display section 51D displays information about the field condition, and displays either "normal" or "wet field". This display is switched in conjunction with the operation of the sensitivity switching button 43G of the switching operation device 43. That is, each time the operator presses the sensitivity switching button 43G, the display in the field condition display section 51D alternates between "normal" and "wet field". Also, when the traveling control section 35 of the steering control section 30 steers and controls the traveling device 11, the control gain of the automatic steering is switched depending on whether the field condition is "normal" or "wet field". That is, the sensitivity switching button 43G accepts a manual operation for switching the control gain of the automatic steering.

[0147] The lamp 43g (see Figure 3) of the sensitivity switching button 43G is turned off when the control gain for when the field condition is "normal" is selected, and is turned on when the control gain for when the field condition is "wet paddy field" is selected.

[0148] The background colors of the mode display unit 50A and the mode display unit 51C differ between the first automatic steering mode and the second automatic steering mode. In the first automatic steering mode, the background color is green, and in the second automatic steering mode, the background color is blue. The character colors of the mode display unit 50A and the mode display unit 51C may be different between the first automatic steering mode and the second automatic steering mode. Furthermore, the background colors and character colors of the status display area 51A, the automatic steering area 51B, and the field condition display area 51D may also be different between the first automatic steering mode and the second automatic steering mode.

[0149] For example, when the control mode of the steering control unit 30 is one of the first automatic steering mode and the second automatic steering mode, and the one of them is in a preparation state, condition information indicating the start condition of automatic steering is displayed in the automatic steering area 51B. For example, the condition information is at least one of the above-mentioned condition items No. 1 to 8, and is switched and displayed according to the above-mentioned conditions #01 to #03. An item that satisfies the condition is displayed in a color different from that of an item that does not satisfy the condition, or is displayed in a flashing color. This makes it easier for the operator to visually recognize the items that satisfy the condition.

[0150] When the control mode of the steering control unit 30 is the first automatic steering mode and the first automatic steering mode is in a preparation state, the above-mentioned condition item No. 6 or condition item No. 7 is displayed in the automatic steering area 51B. When the above-mentioned main mode is set, condition item No. 6 is displayed, and when the above-mentioned secondary mode is set, condition item No. 7 is displayed. In this embodiment, when condition item No. 7 is displayed in the automatic steering area 51B, a selected one of the main reference orientation TA1 and the secondary reference orientation TA2 is displayed on the screen, and the main reference orientation TA1 and the secondary reference orientation TA2 are not displayed simultaneously. This allows the operator to easily recognize whether the attitude orientation of the aircraft 10 is closer to the main reference orientation TA1 or the secondary reference orientation TA2.

[0151] Incidentally, if condition item No. 7 is always displayed in the automatic steering region 51B, the operator may feel bothered. To avoid such inconvenience, the display control unit 24 may be configured to display the above-mentioned condition item No. 7 in the automatic steering region 51B when the difference between the attitude direction of the aircraft 10 and the main reference direction TA1 (or the secondary reference direction TA2) is equal to or less than a preset threshold. The threshold is set to, for example, 10 degrees.

[0152] In addition, the display control unit 24 displays guidance in the automatic steering area 51B to encourage the operator to operate the steering lever 42 according to the azimuth deviation of the aircraft 10. For example, in Fig. 7, when the aircraft 10 at point P1 has an azimuth deviation to the left relative to the main reference azimuth TA1 or the secondary reference azimuth TA2, the display control unit 24 displays a message or the like encouraging a turn operation to the right in the automatic steering area 51B. Also, when the aircraft 10 at point P2 has an azimuth deviation to the right relative to the main reference azimuth TA1 or the secondary reference azimuth TA2, the display control unit 24 displays a message or the like encouraging a turn operation to the left in the automatic steering area 51B.

[0153] The display format of the attitude direction of the aircraft 10, the main reference direction TA1, and the secondary reference direction TA2 is not particularly limited, but may be, for example, a format based on north, south, east, and west (e.g., "north" or "27 degrees east of north"), or may be a unit vector in a coordinate system.

[0154] When the above-mentioned condition #01, condition #02 or condition #03 is satisfied and the conditions for starting automatic steering are met, the state in the first automatic steering mode or the second automatic steering mode transitions from a preparation state to an automatic steering state. As shown in Fig. 10, while the vehicle 10 is traveling a predetermined distance D2 or a predetermined distance D3, the display control unit 24 displays a screen informing the driver of the start of automatic steering in the automatic steering area 51B. The display format of the screen informing the driver of the start of automatic steering is not particularly limited, and may be, for example, a progress bar extending from one side to the other side over time, or may be a numerical value (for example, the number of seconds).

[0155] As shown in FIG. 11, when automatic steering is actually started, the display control unit 24 displays in the automatic steering area 51B that automatic steering is in progress. On the screen during automatic steering, a guide to an operation method for canceling automatic steering is displayed. For example, in FIG. 11, "Automatic steering stopped when harvesting section is raised" is displayed, which corresponds to the above-mentioned state item No. 5. Also, on the screen during automatic steering, "Automatic steering stopped when the main speed change lever is in the neutral position", "Automatic steering stopped when the sub-speed change switch is in the driving mode", "Automatic steering stopped when the reaping clutch is disengaged", or "Automatic steering stopped when the steering lever is tilted to the left or right" may be displayed.

[0156] When automatic steering based on the first automatic steering mode or the second automatic steering mode is ended and the automatic steering state shown in FIG. 4 is shifted to a preparation state, an automatic steering end message is displayed in the automatic steering area 51B.

[0157] Other examples of messages displayed in the automatic steering area 51B are shown below. When the operator presses the first operation button 43A while the automatic steering area 51B is displayed on the display device 4, a message for starting or ending the first automatic steering mode is displayed in the automatic steering area 51B. Also, when the operator presses the second operation button 43B while the automatic steering area 51B is displayed on the display device 4, a message for starting or ending the second automatic steering mode is displayed in the automatic steering area 51B. In addition, when the operator presses the change operation button 43F while the automatic steering area 51B is displayed on the display device 4 and the control mode of the steering control unit 30 is the first automatic steering mode, a message for switching to the main mode or sub mode is displayed in the automatic steering area 51B.

[0158] An icon 53 is displayed at the bottom right corner of each of the status screen 50 and the guidance screen 51, and the icon 53 indicates the control mode of the steering control unit 30. The icon 53 is displayed with a different pattern when the control mode is the manual steering mode, when the control mode is in a preparation state for the automatic steering mode (first automatic steering mode, second automatic steering mode), and when the automatic steering state of the automatic steering mode is being performed. Also, the icon 53 is displayed with a different color when the control mode is the first automatic steering mode and when the control mode is the second automatic steering mode.

[0159] By displaying icon 53 at the bottom right corner of the screen, the operator can check the current control mode of the steering control unit 30 from icon 53 even when the automatic steering area 51B is not displayed on the display device 4.

[0160] [Another embodiment] The present invention is not limited to the configurations exemplified in the above-described embodiments, and other representative embodiments of the present invention will be described below.

[0161] (1) The control modes of the steering control unit 30 include a first automatic steering mode and a second automatic steering mode, but there may be an automatic steering mode that is different from the first automatic steering mode and the second automatic steering mode.

[0162] (2) In the above-described embodiment, the straight-line determination unit 32 is configured to determine whether the machine 10 has traveled straight in the same direction for the predetermined distances D1, D2, and D3. The straight-line determination unit 32 may be configured to determine whether the machine 10 has traveled straight in the same direction for a predetermined time without being limited to this embodiment. In this case, when the straight-line determination unit 32 determines that the combine 1 has traveled straight in the same direction for a predetermined time, the orientation determination unit 33 may be configured to determine the main reference orientation TA1 and the reference orientation TB based on the direction of the straight-line travel performed for the predetermined time. The predetermined time is not particularly limited, and may be, for example, 1 second.

[0163] (3) In the above embodiment, the steering lever 42 is provided at the right front part of the riding section 12, but the present invention is not limited to this embodiment. For example, the steering lever 42 may be provided at the left front part of the riding section 12. That is, the steering lever 42 may be provided in an area on one of the left and right ends of the riding section 12. The steering lever 42 may also be provided in a left and right central area of ​​the riding section 12. Furthermore, the switching operation device 43 may not be provided on the side of the riding section 12 where the steering lever 42 is located. In addition, the steering lever 42 may be a handle. The handle may be provided in the left and right central part of the riding section 12, or may be provided at the left and right ends of the riding section 12.

[0164] (4) In the above embodiment, the switching operation device 43 is provided above the steering lever 42. However, the switching operation device 43 may be provided below the steering lever 42 or on the left or right side thereof.

[0165] (5) In this embodiment, the reference point K is the center position in the left-right direction of the front end portion of the harvesting unit 15. Without being limited to this embodiment, the reference point K may be, for example, the position of the satellite positioning device 80.

[0166] (6) In the above embodiment, the first operation button 43A and the second operation button 43B are shown in different colors, but the first operation button 43A and the second operation button 43B may be shown in the same color. In addition, the first operation button 43A, the second operation button 43B, the first instruction operation button 43C, the second instruction operation button 43D, the azimuth setting operation button 43E, the change operation button 43F, the sensitivity switching button 43G, and the screen switching button 43H do not have to be buttons and may be, for example, lever-type switches.

[0167] (7) In the above embodiment, the first instruction operation button 43C and the second instruction operation button 43D are provided on the switching operation device 43, but the first instruction operation button 43C and the second instruction operation button 43D may be disposed at a location other than the switching operation device 43. Moreover, the first instruction operation button 43C and the second instruction operation button 43D do not have to be buttons and may be, for example, a lever-type switch. Furthermore, the first instruction operation button 43C and the second instruction operation button 43D may be configured as one operation device (for example, a lever-type switch). In addition, the first instruction operation button 43C and the second instruction operation button 43D may not be provided, and the first instruction operation device and the second instruction operation device may be configured as a voice input device.

[0168] (8) The orientation setting operation button 43E may not be provided.

[0169] (9) The first automatic steering mode includes a main mode and a sub mode, but may be configured so that only the main mode exists and no sub mode exists. In this case, the change operation button 43F may not be provided.

[0170] (10) The main reference orientation TA1, the sub-reference orientation TA2, and the reference orientation TB do not have to have a direction from one side to the other. For example, the main reference orientation TA1, the sub-reference orientation TA2, and the reference orientation TB may indicate the inclination of a line in a coordinate system (for example, the inclination of a line passing through the first point Y1 and the second point Y2), may indicate the line itself in a coordinate system (for example, the line itself passing through the first point Y1 and the second point Y2), or may indicate a direction based on the east-west-north-south directions (for example, the "north-south direction" or the "east-west direction").

[0171] (11) In the above-described embodiment, the second automatic steering mode is a control mode in which automatic steering is performed based on the reference heading TB immediately after the reference heading TB is determined by driving straight ahead with manual steering. This is not limited to the embodiment, and for example, the second automatic steering mode may be configured to determine the reference heading TB and then perform automatic steering based on the reference heading TB after other conditions are met. The second automatic steering mode may be configured to perform automatic steering based on the reference heading TB after the reference heading TB is determined by driving straight ahead with manual steering.

[0172] (12) The above-mentioned first operation button 43A and second operation button 43B may be configured as one operation tool (for example, a lever-type switch). Also, the first operation button 43A and the second operation button 43B may not be provided, and the first operation unit and the second operation unit may be configured as a voice input device or function.

[0173] The configurations disclosed in the above-mentioned embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, unless a contradiction occurs. In addition, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments, and can be appropriately modified within the scope of the present invention. [Industrial Applicability]

[0174] The present invention is applicable to work vehicles, and therefore is not limited to the general-purpose combine harvester exemplified in this embodiment, but can also be applied to head-feeding combine harvesters, various harvesters (e.g., corn harvesters, sugarcane harvesters, potato harvesters, beet harvesters, carrot harvesters, etc.), tractors, rice transplanters, fertilizer management machines, self-propelled spreaders, self-propelled grass cutters, etc. [Explanation of symbols]

[0175] 11: Running gear 12: Boarding section 30: Steering control unit 42: Steering lever (steering device) 43: Switching device 43A: First operation button (first operation part) 43B: Second operation button (second operation part) 43C: First instruction operation button (first instruction operation device) 43D: Second instruction operation button (second instruction operation tool) 43E: Orientation setting operation button (orientation setting operation tool) 43F: Change operation button (change operation tool) GL: Automatic steering target line (driving reference) TA1: Main reference direction (driving reference) TA2: Secondary reference direction (driving reference, secondary driving reference) TB: Reference direction (driving reference) Y1: First point (starting point) Y2: Second point (end point)

Claims

[Claim 1] A work vehicle that travels while switching between manual steering and automatic steering, A steerable running device; A steering control unit having a plurality of control modes and capable of executing the automatic steering that controls the traveling device to automatically travel the vehicle in accordance with a traveling standard.

Images