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

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-136015 Summary of the Invention [Problem to be solved by the invention]

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

[0005] Furthermore, if the system is configured to reset the driving standards 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 be deleted or that the system will be forced to manage multiple redundant driving standards, 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 that is 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 travel device, and a steering control unit that has a plurality of control modes and is capable of executing the automatic steering by controlling the travel device to automatically travel the vehicle in accordance with a travel standard, the plurality of control modes including a first automatic steering mode in which the automatic steering is performed based on the travel standard that has been set in advance, and a second automatic steering mode in which the automatic steering is performed as is in response to the travel standard being determined by traveling with the manual steering, and the steering control unit is configured to control the vehicle to travel in accordance with the travel standard being determined by the manual steering, a specified distance or a specified time and determining whether the aircraft has traveled straight or approximately straight over the entire the predetermined distance or the predetermined time In response to determining that the vehicle has traveled straight or approximately straight for a period of time, the driving reference for the first automatic steering mode and the driving reference for the second automatic steering mode are determined based on the direction of the straight or approximately straight traveling. and a mode switching unit that accepts a selection of whether the automatic steering is to be performed in the first automatic steering mode or the second automatic steering mode. It is characterized by: In addition, 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 that has a plurality of control modes and is capable of performing the automatic steering by controlling the traveling device to automatically travel the vehicle in accordance with a traveling standard, and the plurality of control modes include a first automatic steering mode in which the automatic steering is performed based on the predetermined traveling standard, and a second automatic steering mode in which the automatic steering is performed as is in accordance with the traveling standard determined by traveling with manual steering, and the steering control unit determines whether the vehicle has traveled straight or approximately straight over a predetermined interval, and in accordance with determining that the vehicle has traveled straight or approximately straight over the interval, determines the traveling standard for the first automatic steering mode and the traveling standard for the second automatic steering mode based on the direction of straight or approximately straight travel. In the present invention, it is preferable to include a display device and a display control unit that controls the display device to display a mode display unit that indicates the control mode. In the present invention, it is preferable that the display control unit controls the display device so that the first automatic steering mode and the second automatic steering mode are displayed distinguishably on the mode display unit depending on the current control mode. In the present invention, when the control mode is the first automatic steering mode or the second automatic steering mode, the display control unit preferably controls the display device to display the first automatic steering mode or the second automatic steering mode on the mode display unit, and to distinguishably display an automatic steering state indicating a state in which automatic steering is being executed in the first automatic steering mode or the second automatic steering mode, and a preparation state indicating a state in which manual steering is being used to prepare for the start of automatic steering in the first automatic steering mode or the second automatic steering mode. In the present invention, a detection unit is provided that detects the stop of work, and when the detection unit detects the stop of work while the automatic steering is being performed, the steering control unit terminates the automatic steering while maintaining the control mode, and the display control unit preferably controls the display device to display the first automatic steering mode or the second automatic steering mode on the mode display unit and to display the preparation state in response to the steering control unit having terminated the automatic steering while maintaining 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 multiple control modes, and the control mode can be switched between the first automatic steering mode and the second automatic steering mode, for example, by an operator operating a switching device. In the second automatic steering mode, automatic steering is performed after determining a driving standard by driving with manual steering. Therefore, for example, if an operator desires temporary automatic steering based on a standard other than a pre-set driving standard, the operator can easily perform temporary automatic steering by operating the switching device to switch the control mode to the second automatic steering mode. Therefore, the present invention does not require the operator or manager to delete a previously set driving standard or manage multiple unnecessary driving standards, thereby reducing the effort required for the operator or manager. This achieves a work vehicle capable of various automatic steering operations while reducing the effort required for setting driving standards.

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

[0010] This configuration enables 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 enables 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 and right ends of the boarding section and which accepts the manual steering by the passenger, and it is preferable that the switching operation device be provided on the side of the boarding section where the steering operation device is located.

[0014] With this configuration, the operator (passenger) can more easily see ahead from the riding section, compared to a configuration in which the steering operation device and the switching operation device are provided in the left-right central region of the riding section. Also, with this configuration, the steering operation device and the switching operation device are provided together in a region on one of the left and right ends of the riding section. Therefore, compared to a configuration in which the steering operation device and the switching operation device are provided separately on one of the left and right sides of the riding section, the operator can use the steering operation device and the switching operation device 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, with the switching operation device positioned above the steering operation device, so the operator can operate the switching operation device simply by 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, if the 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 operating unit. Furthermore, if the operator desires temporary automatic steering based on a criterion different from the preset driving criterion, the operator can switch the control mode to the second automatic steering mode by operating the second operating unit. In other words, the operator can perform temporary automatic steering based on a criterion different from the preset driving criterion simply by operating the second operating unit. Therefore, there is no need to set additional driving criteria for temporary automatic steering, and the operator can easily use 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 section and the second operating section are displayed in different colors, reducing the risk that the operator will mistakenly press either the first operating section or the second operating section.

[0021] In the present invention, it is preferable that the switching operating device has a first indicating operating device that accepts manual operation to set 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 to set an end point in the teaching driving.

[0022] According to this configuration, the start point and end point of teaching travel can be set by operating the first and second indicating devices, and the first and second indicating devices are combined into the switching device. Therefore, compared to a configuration in which the first and second indicating devices are not combined 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 traveling 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 driving reference direction in advance, which allows the operator or manager to easily set the driving reference without having to perform 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 standard, and a secondary mode in which the automatic steering is performed based on the predetermined driving standard or a secondary driving standard automatically generated based on the driving standard, 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 preset driving standards. This eliminates the need to run the aircraft to set new driving standards, making it easier to set multiple driving standards. Furthermore, because the operator can select whether to use multiple driving standards by operating the change operating tool, the operator can easily select a variety of automatic steering options. [Brief explanation of the drawings]

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

[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 arrow F shown in Figures 1 and 2 will be referred to as "front" and the direction of arrow B as "rear." Furthermore, the direction of arrow L shown in Figure 1 will be referred to as "left" and the direction of arrow R as "right." Furthermore, the direction of arrow U shown in Figure 2 will be referred to as "up" and the direction of arrow D as "down."

[0029] [Overall configuration of the combine] As shown in Figure 1, a standard combine harvester 1, which is an example of a work vehicle, will be described. The combine harvester 1 has a body 10 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 conveying 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 also remotely operate the combine harvester 1 from outside the combine harvester 1.

[0031] The harvesting unit 15 is provided at the front of the machine body 10. The transporting unit 16 is provided behind the harvesting unit 15. The harvesting unit 15 and the transporting unit 16 are configured to be able to move up and down relative to the main body of the machine body 10 (the traveling device 11, the riding unit 12, the threshing device 13, the grain tank 14, etc.) via a cylinder (not shown). In other words, the harvesting unit 15 and the transporting unit 16 are configured to be able to move up and down 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 unit 15 harvests crops in the field. The combine 1 is capable of reaping travel, traveling on the traveling device 11 while reaping planted stalks in the field with the harvesting unit 15. Note that "work travel" in this embodiment specifically refers to reaping travel. Note that "work travel" may also refer to performing work other than reaping planted stalks 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 needed. 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 able to display 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 combine harvester travels by manual steering by the operator. Automatic steering travel means that the combine harvester travels by automatic steering. Automatic steering means that the combine harvester 1 steers automatically.

[0036] The automatic steering driving may or may not include large direction changes such as α-turns, U-turns, etc. Furthermore, 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 being manually steered or automatically steered, the speed of the combine harvester 1 changes when the operator operates the main speed change lever 40. In other words, when the combine harvester 1 is being manually steered or automatically steered, 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 that moves the combine harvester 1 forward while changing its speed, a neutral position that stops the combine harvester 1, or a reverse operating position that moves the combine harvester 1 backward while changing its speed.

[0038] The auxiliary speed change switch 41 is configured to be able to switch an auxiliary speed change device (not shown, for example, a multi-stage speed change device) between a speed change state for traveling and a speed change state for working. The auxiliary speed change switch 41 is provided at the free end of the main speed change lever 40, but may be provided at a location other than the main speed change lever 40. The auxiliary 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 lift 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" in this invention.

[0040] The steering lever 42 is a stick-type lever that swings forward, backward, 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 left or right, a speed difference occurs 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] Furthermore, when the operator operates the steering lever 42 in the forward / backward 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 unit" of the present invention, and the second operation button 43B corresponds to the "second operation unit" of the present invention.

[0043] In this embodiment, the color of the letters and figures on the first operation button 43A, the first command operation button 43C, the second command operation button 43D, the azimuth setting operation button 43E, and the change operation button 43F are the same, green. The color of the letters and figures on the second operation button 43B is different from the color of the letters and figures on the first operation button 43A, 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 letters and figures on the sensitivity switching button 43G and the screen switching button 43H is different from the color of the letters and figures on the first operation button 43A and the second operation button 43B, white or gray. The first command operation button 43C corresponds to the "first command operation tool" in this invention, and the second command operation button 43D corresponds to the "second command operation tool" in this invention. The azimuth setting operation button 43E corresponds to the "azimuth setting operation tool" in this 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 unit 81 shown in FIG. 3. The satellite positioning device 80 receives positioning signals from artificial satellites (not shown) used in GNSS (Global Satellite Navigation Systems, such as GPS, GLONASS, Galileo, QZSS, and BeiDou). The inertial measurement unit 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 axis directions over time. In other words, the inertial measurement unit 81 complements the satellite navigation provided by the satellite positioning device 80. The inertial measurement unit 81 may be incorporated into the satellite positioning device 80 or may be located 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 control unit 20 and 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] The control unit 20 receives as input a positioning signal from the satellite positioning unit 80 and a detection result from the inertial measurement unit 81. The positioning signal from the satellite positioning unit 80 is sent to the vehicle position calculation unit 22. The detection result from the inertial measurement unit 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 able to transmit power to both 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 unit 15. Therefore, the harvesting height sensor 45 is configured to be able to detect whether the harvesting unit 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 body 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 body 10.

[0052] The vehicle orientation calculation unit 23 receives the position coordinates of the machine body 10 from the vehicle position calculation unit 22. Then, the vehicle orientation calculation unit 23 calculates the attitude orientation of the machine body 10 based on the detection results from 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 has traveled for a certain period of time after the initial attitude and orientation is 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 travel.

[0054] Then, the vehicle orientation calculation unit 23 updates the calculated orientation by adding the calculated amount of change in orientation to the initial attitude orientation. After that, the amount of change in attitude orientation is similarly calculated at regular time intervals, and the calculated results of attitude orientation are successively updated. 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 depending on 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 screen 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 able to perform automatic steering, which controls the traveling device 11 to automatically travel the vehicle 10 along an automatic steering target line GL, which will be described later. 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 based on the automatic steering control signal so that the combine 1 performs automatic steering traveling. The first automatic steering mode is a control mode in which automatic steering is performed based on a preset main reference heading TA1. 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 traveling straight ahead with manual steering. The main reference heading TA1 and the reference heading TB correspond to the "traveling reference" of the present invention. In addition, the secondary reference heading TA2 and the automatic steering target line GL described below also correspond to the "traveling reference" of the present invention. Note that "straight traveling" 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. Alternatively, 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 , and a travel control unit .

[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 over a predetermined distance.

[0064] The orientation determination unit 33 determines a main reference orientation TA1 for executing automatic steering when the steering control unit 30 is in the first automatic steering mode. Furthermore, the orientation determination unit 33 determines a reference orientation TB for executing 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 driving control unit 35 is configured to be able to control the driving device 11 so that the vehicle 10 travels straight along the automatic steering target line GL. The driving control unit 35 controls the driving device 11 to control the driving of the vehicle 10.

[0065] [Method for determining the reference direction] In this embodiment, when the vehicle 10 travels straight ahead 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. Traveling the vehicle 10 in a straight ahead direction for a predetermined distance to set the main reference orientation TA1 is referred to as "teaching travel."

[0066] Teaching travel in this embodiment will be described with reference to Figure 5. When the operator presses the first instruction operation button 43C, the position of the aircraft 10 at the time of operating 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 teaching travel, which sets in advance the main reference heading TA1 used in the first automatic steering mode.

[0067] To prevent an erroneous operation by the operator, when the operator presses the first command 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 end of one second may be registered as the first point Y1. When the first point Y1 is registered, the lamp 43c (see FIG. 3) of the first command operation button 43C lights up.

[0068] After registering the first point Y1, the operator manually moves the vehicle 10 in a straight line (or approximately straight line) from the first point Y1. At this time, the straight-line movement determination unit 32 shown in FIG. 3 determines whether the vehicle 10 has moved in a straight line in the same direction over a predetermined distance D1 in manual steering mode. More specifically, a signal indicating the operation state of the steering lever 42 is sent from the steering lever 42 to the steering control unit 30 via the detection unit 21. Based on this signal, the straight-line movement 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, one meter.

[0069] Furthermore, 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 moving 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 moving determination unit 32 determines that the vehicle 10 has moved straight in the same direction for the predetermined distance D1. If the calculated movement distance does not reach the predetermined distance D1, the straight-line moving 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 determines that the machine 10 has traveled straight in the same direction for 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 to set the second point Y2 in the teaching travel.

[0071] In order to prevent erroneous operation by the operator, a configuration may be adopted in which, when the operator presses the second instruction operation button 43D for a long time, for example, 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, if the operator presses the second instruction operation button 43D when the first point Y1 has not been set, neither the first point Y1 nor the second point Y2 is set.

[0072] Then, the direction determining unit 33 determines the main reference direction 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 command operation button 43C and the second command operation button 43D for a long time, for example, for one second, in a state in which the main reference direction TA1 has been determined based on the direction of the line connecting the first point Y1 and the second point Y2, the setting of the main reference direction TA1 is canceled. At this time, the lamps 43c and 43d are turned off.

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

[0075] The main reference heading TA1 can also be set by the method shown in Fig. 6. When the operator presses the heading setting operation button 43E of the switching operation device 43, the display control unit 24 controls the display device 4 to display the heading setting screen 52 based on the operation signal from the heading setting operation button 43E. In other words, the heading setting operation button 43E accepts a manual operation for setting in advance the heading of the main reference heading TA1 to be used in the first automatic steering mode. The heading setting screen 52 is configured so that it can also 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 the 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 the 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 direction TA1 has been determined based on the numerical value set by the operator on the direction setting screen 52, and turns off when the main reference direction TA1 has not been determined based on the numerical value set by the operator on the direction 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 the north, south, east, and west 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 heading TA1 can be set by the operator operating the first instruction operation button 43C and the second instruction operation button 43D, or by the operator setting a numerical value for the heading displayed on the heading setting screen 52. The control mode of the steering control unit 30 when the main reference heading TA1 is set may be either a manual steering mode or an automatic steering mode.

[0080] As described above, the control unit 20 includes a storage device (not shown). Once 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] After determining the main reference azimuth TA1, the azimuth determination unit 33 also sets a secondary reference azimuth TA2 as shown in FIG. 5. The secondary reference azimuth TA2 faces a direction shifted by 90 degrees from the main reference azimuth TA1. In other words, the secondary reference azimuth TA2 is automatically set to face a direction shifted by 90 degrees from the main reference azimuth TA1. As will be described in detail 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 azimuth TA2 is used in the secondary mode. Note that the azimuth determination unit 33 may be configured to set the secondary reference azimuth TA2 when the control mode of the steering control unit 30 is switched to the secondary mode. The set secondary reference azimuth TA2 is stored in a storage device (not shown). The secondary reference azimuth TA2 corresponds to the "secondary driving reference" of the present invention.

[0082] [First automatic steering mode] The first automatic steering mode will be described with reference to Figures 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 Figures 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 of the first operation button 43A (see Figure 3) lights up.

[0083] As shown in Figure 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 to start 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. When the control mode of the steering control unit 30 is switched from the manual steering mode to the first automatic steering mode, the system 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 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. In addition, when operation #01 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 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 determines whether condition #01 or 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 prompting the operator to perform an operation to transition to the automatic steering state. At this time, the operator manually operates the combine harvester 1 to prepare the conditions for transitioning to the automatic steering state. In other words, based on the preparation state of the first automatic steering mode, the operator performs manual steering to align the heading attitude of the machine body 10 with the primary reference heading TA1 or the secondary reference heading TA2. Figure 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] Condition #01 and 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: The vehicle 10 is moving forward based on the calculation result of the vehicle position calculation unit 22. Condition item No. 2: The main speed change lever 40 provided on the riding section 12 is set to the forward operation position described above. Condition item No. 3: The auxiliary speed change switch 41 is in the above-described work speed change state (the auxiliary speed change device (not shown) is in the work speed change 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 unit 15 is lowered to the above-mentioned working position.

[0090] The first automatic steering mode of this embodiment includes a primary mode and a secondary mode. The primary mode is a mode in which automatic steering is performed based on a preset primary reference orientation TA1. The secondary mode is a mode in which automatic steering is performed based on the primary reference orientation TA1 or a secondary reference orientation TA2 that is automatically generated based on the primary reference orientation 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. In other words, each time operation #03 is performed, the main mode and the sub mode are switched alternately. 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 lights up 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. Condition #01 for transitioning from the first automatic steering mode to the 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 Nos. 1 to 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 heading TA1 and the secondary reference heading 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 heading TA1 and the secondary reference heading TA2, the heading that has the smaller heading deviation from the attitude heading of the aircraft 10 calculated by the vehicle heading 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 unit 30 is set to the sub mode, the condition #02 for transitioning from the first automatic steering mode 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 the selected one of the main reference direction TA1 and the secondary reference direction TA2 is within a predetermined angle (e.g., 3 degrees).

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

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

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

[0102] When the first automatic steering mode transitions to the automatic steering state, the path generation 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. Information indicating the automatic steering target line GL is then sent from the path generation 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 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 path generation unit 34. More specifically, the travel control unit 35 controls the travel of the machine body 10 so that reaping travel is performed by automatic steering 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 above-mentioned forward operating position, the vehicle speed of the combine harvester 1 changes while automatic steering continues.

[0104] In this way, 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. "State #01" is a state related to the stop of work. That is, the detection unit 21 detects the stop of work. State #01 includes the following state items No. 1 to No. 6.

[0106] Status item No. 1: The main speed change lever 40 is operated to an operating position other than the forward operating position. Status item No. 2: The auxiliary speed change switch 41 is no longer in the work speed change state (the auxiliary speed change device (not shown) is no longer in the work speed change state). Status item No. 3: The reaping / threshing clutch 44 is in a state where power is not transmitted 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 harvest 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 to the left or right by more than a preset operation amount.

[0107] In other words, 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. In other words, if the detection unit 21 detects that work has stopped 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 the 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 primary 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 immediately after only being temporarily stopped.

[0109] In this way, the detection unit 21 is configured to detect the stop of work when a predetermined stop condition is satisfied, which 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 auxiliary speed change device (not shown) is no longer in the operating 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 is moved to a non-working position; an operation for moving the harvesting unit 15 to a non-working position is performed; and the steering lever 42 is operated.

[0110] Furthermore, if 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, if 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 lit when the control mode of the steering control unit 30 is the first automatic steering mode, and is extinguished 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, automatic steering based on the first automatic steering mode is particularly useful when the field is rectangular. When the combine harvester 1 performs reapering travel by moving back and forth within the inside of the field, the straight traveling direction during reapering 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 reapering travel. Also, when the combine harvester 1 performs in-between travel in the field (reapering 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 seeing ahead of the machine body 10, 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] [Regarding the second automatic steering mode] The second automatic steering mode will be described with reference to Figures 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, automatic steering based on the second automatic steering mode is possible even if the main reference heading TA1 is not set in advance. Furthermore, even if the main reference heading TA1 is set in advance, automatic steering is possible based on a reference heading TB that is 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 FIGS. 4 and 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 system 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 of the second operation button 43B (see FIG. 3) lights up.

[0116] As shown in Figure 4, similar to 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 to start 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. 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 the 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 determines whether the condition #03 for transitioning to the automatic steering state is satisfied. At the same time, the display control unit 24 displays a guidance screen on the display device 4 to prompt the operator to perform an operation to transition to the automatic steering state. At this time, the operator manually operates the combine harvester 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 Figure 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 Figure 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 Nos. 1 to 5.

[0120] Condition item No. 8: The straight-line determination unit 32 determined that the machine body 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 ready state, the orientation determination unit 33 stores the transition of the position coordinates of the vehicle 10 while the steering lever 42 is not being operated left or right, based on the position coordinates of the vehicle 10 received from the host vehicle position calculation unit 22. Then, when the straight-line traveling 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 from the stored position coordinates as a first point Y3 and a second point Y4.

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

[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 direction determination unit 33 determines a reference direction 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 extending from the first point Y3 to the second point Y4. Here, the direction of the straight line extending 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 second point Y4, and the vehicle 10 travels a predetermined distance D3 between first point Y3 and second point Y4. When the second autosteer mode is in a ready state and condition #03 for switching to the second autosteer mode is satisfied, the path generation unit 34 generates an autosteer target line GL, and the second autosteer mode transitions from a ready state to an autosteer state.

[0128] At this time, the path generation unit 34 generates an automatic steering target line GL so that it passes through a specific reference point K on the aircraft 10 in a planar view and extends in a direction along the reference heading 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 performs automatic steering so as to automatically travel straight ahead along the reference heading 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 now 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 terminates automatic steering. "State #01" is a state related to the stoppage of work, and is when any of the above-mentioned state items No. 1 to 6 is detected by the detection unit 21. In other words, state #01 is when the operator performs an operation of any of state items No. 1 to 6. In other words, the detection unit 21 detects the stoppage 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, if the detection unit 21 detects that work has stopped while automatic steering based on the second automatic steering mode is being performed, the steering control unit 30 ends 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, if the operator temporarily stops automatic steering by performing an operation corresponding to state #01 at the edge of a field, then turns the machine 10 and then drives it straight ahead, it is possible to satisfy condition #03 described above. As a result, automatic steering is only temporarily stopped, and then resumes.

[0133] Furthermore, if 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 automatic steering by the steering control unit 30 ends. In other words, if 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 heading such as the main reference heading TA1 is not set in advance, the reference heading TB is determined when the vehicle is traveling straight ahead, 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, triangular fields or fields with polygonal shapes of pentagons or more. The operator can also use the first automatic steering mode in the in-between traveling described above in the description of the first automatic steering mode, and the second automatic steering mode in traveling other than in-between traveling. In this way, in this embodiment, the operator can selectively use the first automatic steering mode and the second automatic steering mode.

[0138] Although the second autopilot mode is configured to set one reference heading TB, it may also be configured to set the reference heading TB and another reference heading perpendicular to the reference heading TB. For example, if a 90-degree turn is expected after autopiloting is performed along the reference heading TB, the reference heading TB and the other reference heading may also be set. With this configuration, after autopiloting is performed along the reference heading TB, the operator can turn the aircraft 10 90 degrees and then easily align the attitude heading of the aircraft 10 to a heading perpendicular to the reference heading TB, making it easier to resume autopiloting based on the second autopilot mode along the other reference heading.

[0139] [About the automatic steering screen] 9, the display control unit 24 is capable of controlling 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, which accepts a manual operation for switching the display on 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 on the display device 4 switches to the guidance screen 51.

[0140] Note that the display device 4 may be configured so that 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 switches to the status screen 50. In other words, the display on the display device 4 may be configured so that the display on the display device 4 alternates 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 configured to be linked to the display and non-display of the guidance screen 51. The guidance screen 51 may also be displayed by the operator operating a button (not shown, for example, a cross button) provided on the display device 4.

[0141] The status screen 50 displays, on the entire screen, information such as the vehicle speed of the combine 1, 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. 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 center left and right at the top of the status screen 50. The mode display section 50A displays the current control mode of the steering control section 30. 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 areas divided into an upper and lower section. A status display area 51A is displayed in the lower section of the guidance screen 51. Information about 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 in the grain tank 14, etc., is displayed in the status display area 51A, similar to what is displayed on the guidance screen 51. An automatic steering area 51B is displayed in the upper section of the guidance screen 51. Information about automatic steering is displayed in the automatic steering area 51B. In other words, the display control unit 24 displays information about traveling and work in the lower status display area 51A of the guidance screen 51, which divides the entire screen into two, and also displays information about automatic steering in the automatic steering area 51B.

[0144] The automatic steering area 51B is displayed in the upper region of the guidance screen 51. Therefore, 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 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 located in the upper right corner of the automatic steering area 51B. The field condition display section 51D displays information about the field condition, displaying either "normal" or "damp paddy 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 "damp paddy field." Furthermore, when the traveling control section 35 of the steering control section 30 controls the steering of the traveling device 11, the control gain of the automatic steering is switched depending on whether the field condition is "normal" or "damp paddy field." That is, the sensitivity switching button 43G accepts 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 "damp paddy field" is selected.

[0148] The background colors of the mode display units 50A and 51C differ between the first automatic steering mode and the second automatic steering mode. The background color is green in the first automatic steering mode, and blue in the second automatic steering mode. The character colors of the mode display units 50A and 51C may also differ 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 differ 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 that one is in a ready state, condition information indicating the conditions for starting 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 No. 8, and is displayed in a switchable manner according to the above-mentioned conditions #01 to #03. Items that satisfy the conditions are displayed in a different color from items that do not satisfy the conditions, or are displayed in a flashing color. This makes it easier for the operator to visually identify items that satisfy the conditions.

[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 ready 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 primary 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 primary reference heading TA1 and the secondary reference heading TA2 is displayed on the screen, and the primary reference heading TA1 and the secondary reference heading TA2 are not displayed simultaneously. This allows the operator to easily recognize whether the attitude heading of the aircraft 10 is closer to the primary reference heading TA1 or the secondary reference heading TA2.

[0151] Incidentally, if condition item No. 7 is always displayed in the automatic steering area 51B, the operator may find it annoying. 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 area 51B when the difference between the attitude direction of the aircraft 10 and the primary reference direction TA1 (or 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 prompt the operator to operate the steering lever 42 depending on the azimuth deviation of the aircraft 10. For example, in Figure 7, if the aircraft 10 at point P1 has an azimuth deviation to the left with respect to the primary reference azimuth TA1 or the secondary reference azimuth TA2, the display control unit 24 displays a message or the like prompting the operator to turn right in the automatic steering area 51B. Also, if the aircraft 10 at point P2 has an azimuth deviation to the right with respect to the primary reference azimuth TA1 or the secondary reference azimuth TA2, the display control unit 24 displays a message or the like prompting the operator to turn 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 "north 27 degrees east"), 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 the preparation state to the automatic steering state. As shown in Fig. 10, while the vehicle 10 is traveling the predetermined distance D2 or the predetermined distance D3, the display control unit 24 displays a screen in the automatic steering area 51B notifying the start of automatic steering. The display format of the screen notifying 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 a numerical value (for example, the number of seconds).

[0155] As shown in FIG. 11, when automatic steering actually starts, the display control unit 24 displays in the automatic steering area 51B that automatic steering is in progress. On the screen during automatic steering, guidance on the 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 status item No. 5. Furthermore, on the screen during automatic steering, "Automatic steering stopped when the main speed change lever is in the neutral position" may be displayed, or "Automatic steering stopped when the auxiliary speed change switch is in the travel mode" may be displayed, or "Automatic steering stopped when the reaping clutch is disengaged" may be displayed, or "Automatic steering stopped when the steering lever is tilted to the left or right."

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

[0157] Other examples of messages that may be 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 indicating the start or end of the first automatic steering mode is displayed in the automatic steering area 51B. Furthermore, when the operator presses the second operation button 43B while the automatic steering area 51B is displayed on the display device 4, a message indicating the start or end of 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 indicating switching to the primary mode or secondary mode is displayed in the automatic steering area 51B.

[0158] An icon 53 is displayed in the lower 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 vehicle is in preparation for the automatic steering mode (first automatic steering mode, second automatic steering mode), or when the vehicle is in the automatic steering state of the automatic steering mode. The icon 53 is also displayed with a different color when the control mode is the first automatic steering mode and when the vehicle is in 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 using 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 exemplified 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 also 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. This embodiment is not limited to this, and 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 period of time. In this case, if the straight-line determination unit 32 determines that the combine 1 has traveled straight in the same direction for a predetermined period of 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 over the predetermined period of time. The predetermined period of time is not particularly limited, and may be, for example, one second.

[0163] (3) In the above-described embodiment, the steering lever 42 is provided at the right front of the riding section 12, but this is not limiting. For example, the steering lever 42 may be provided at the left front 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-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-right central area of ​​the riding section 12, or may be provided at the left or right end of the riding section 12.

[0164] (4) In the above embodiment, the switching operation device 43 is provided above the steering lever 42, but it may also 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 at the front end of the harvesting unit 15. However, without being limited to this embodiment, the reference point K may be the position of the satellite positioning device 80, for example.

[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-described embodiment, the first instruction operation button 43C and the second instruction operation button 43D are provided on the switching operation device 43. However, the first instruction operation button 43C and the second instruction operation button 43D may be disposed in a location separate from the switching operation device 43. The first instruction operation button 43C and the second instruction operation button 43D do not have to be buttons and may be, for example, lever-type switches. Furthermore, the first instruction operation button 43C and the second instruction operation button 43D may be configured as a single 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 primary mode and a secondary mode, but may be configured so that only the primary mode exists and no secondary mode exists. In this case, the change operation button 43F may not be provided.

[0170] (10) The primary reference orientation TA1, the secondary reference orientation TA2, and the reference orientation TB do not have to have a direction from one to the other. For example, the primary reference orientation TA1, the secondary reference orientation TA2, and the reference orientation TB may indicate the gradient of a line in a coordinate system (for example, the gradient of a line passing through the first point Y1 and the second point Y2), or may indicate the line itself in the 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 four 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 a limitation, and the second automatic steering mode may be configured, for example, 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 determine the reference heading TB by driving straight ahead with manual steering and then perform automatic steering based on the reference heading TB.

[0172] (12) The first operation button 43A and the second operation button 43B may be configured as a single 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-described embodiments (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments, unless a contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these, and can be modified as appropriate within the scope of the purpose 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 illustrated 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 control device) 43: Switching operation tool 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: Azimuth setting operation button (azimuth 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

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 machine body in accordance with a traveling standard; The plurality of control modes include a first automatic steering mode in which the automatic steering is performed based on the preset driving criterion, and a second automatic steering mode in which the automatic steering is performed as is in response to the driving criterion being determined by driving with the manual steering, the steering control unit determines whether the aircraft has traveled straight or approximately straight for a predetermined distance or a predetermined time, and in response to determining that the aircraft has traveled straight or approximately straight for the predetermined distance or the predetermined time, determines the traveling standard for the first automatic steering mode and the traveling standard for the second automatic steering mode based on the direction of the straight or approximately straight traveling; A work vehicle equipped with a mode switching unit that accepts a selection of whether the automatic steering is to be performed in the first automatic steering mode or the second automatic steering mode.

2. a display device; The work vehicle according to claim 1, further comprising: a display control unit that controls the display device to display a mode display unit that indicates the control mode.

3. 3. The work vehicle according to claim 2, wherein the display control unit controls the display device so that the first automatic steering mode and the second automatic steering mode are displayed distinguishably on the mode display unit according to the current control mode.

4. 4. The work vehicle according to claim 2 or 3, wherein the display control unit, when the control mode is the first automatic steering mode or the second automatic steering mode, displays the first automatic steering mode or the second automatic steering mode on the mode display unit, and controls the display device to distinguishably display an automatic steering state indicating a state in which automatic steering is being performed in the first automatic steering mode or the second automatic steering mode, and a preparation state indicating a state in which manual steering is being used to prepare for the start of automatic steering in the first automatic steering mode or the second automatic steering mode.

5. A detection unit is provided to detect the stop of work, When the detection unit detects that work has stopped while the automatic steering is being performed, the steering control unit terminates the automatic steering while maintaining the control mode, The work vehicle according to claim 4, wherein the display control unit controls the display device to display the first automatic steering mode or the second automatic steering mode on the mode display unit and to display the preparation state in response to the steering control unit ending the automatic steering while maintaining the control mode.

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