Work vehicle

Abstract

To improve workability.SOLUTION: In a working vehicle that includes: a steering member for performing a steering operation of a traveling vehicle body; a position information acquisition device for acquiring position coordinates of the traveling vehicle body; an automatic traveling device for operating the steering member to cause the traveling vehicle body to automatically travel; and a control device for controlling each part, a first reference position registered at one point of a field and a second reference position registered at another point of the field can be registered, a line connecting the first reference position and the second reference position is travel reference data to be referenced to at traveling, and an operation part for performing on / off operation of automatic travel is provided, wherein the operation part is a lever member. In a case where the travel reference data is registered, when the lever member is operated to one side, the automatic travel becomes "ON"; when the second reference position is registered, the second reference position is not registered if a distance from a position at which the first reference position is acquired is less than a predetermined distance.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, for example, in a work vehicle that travels in a field with a traveling vehicle body and performs ground work with a work device mounted on the traveling vehicle body, the work device acquires position information at the start and end of work when it is turned on and off, creates a reference line from the acquired work start position and work end position, and has a function of automatically steering the steering wheel along the created reference line (see, for example, Patent Document 1).

[0003] In such a work vehicle, since the positions where the work device is turned on and off are acquired as the work start position and the work end position, the operation of acquiring the work start position and the work end position becomes unnecessary.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the conventional work vehicle as described above does not consider the possibility of incorrect operation in the process of creating the reference line.

[0006] For example, there is a problem that the operator accidentally touches the automatic straight-ahead setting member and the reference line becomes shorter.

[0007] The present invention has been made in view of the above, and an object thereof is to provide a work vehicle capable of improving workability.

Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, in the work vehicle (1) including a steering member (35) for steering the traveling vehicle body (2), a position information acquisition device (200) for acquiring the position coordinates of the traveling vehicle body (2), an automatic driving device (205) for operating the steering member (35) to automatically drive the traveling vehicle body (2), and a control device (100) for controlling each part, it is possible to register a first reference position (A) registered at one point in the field and a second reference position (B) registered at another point in the field, and a line connecting the first reference position (A) and the second reference position (B) is traveling reference data serving as a reference for traveling. An operation unit for performing an on / off operation of the automatic driving is provided, the operation unit is a lever member, and when the traveling reference data is registered, in the first direction when the lever member is operated, the automatic driving is "on", and when registering the second reference position (B), if the distance from the position where the first reference position (A) is acquired is less than a predetermined distance, the second reference position (B) is not registered.

[0009] The work vehicle according to claim 2 is the work vehicle according to claim 1, wherein in the second direction when the lever member is operated for a predetermined time, the line connecting the registered first reference position (A) and second reference position (B) is deleted.

[0010] The work vehicle according to claim 3 is the work vehicle according to claim 1 or 2, including a work device mounted on the traveling vehicle body and performing work in the field, and when the position information acquisition device (200) recognizes that it is a ridging operation which is the final process of work in the field, the line connecting the registered first reference position (A) and second reference position (B) is deleted.

Advantages of the Invention

[0011] According to the work vehicle of the present invention, workability in registering and deleting the automatic straight traveling reference can be improved.

Brief Description of the Drawings

[0012]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0013] Hereinafter, embodiments of the work vehicle disclosed in the present application will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited by the embodiments shown below.

[0014] With reference to FIGS. 1 and 2, the overall configuration of a work vehicle (seedling transplanter) 1 according to an embodiment will be described. FIG. 1 is a left side view of the work vehicle (seedling transplanter) 1. FIG. 2 is a plan view of the work vehicle (seedling transplanter) 1. In FIG. 2, for convenience of explanation, wheels (front wheels, rear wheels), etc. are omitted. Further, hereinafter, as the work vehicle 1, a seedling transplanter that plants seedlings in a field while traveling in the field will be described as an example.

[0015] In the following description, the front-rear direction is the traveling direction when the work vehicle (hereinafter referred to as the seedling transplanter) 1 travels straight. The front side in the traveling direction is defined as "front", and the rear side is defined as "rear". The traveling direction of the seedling transplanter 1 is the direction from the driver's seat 41 to the steering member (hereinafter referred to as the steering wheel) 35 when traveling straight (see Fig. 1).

[0016] The left-right direction is a direction that is horizontally orthogonal to the front-rear direction. Hereinafter, the left and right are defined toward the "front" side. That is, with the operator (also referred to as the driver) sitting on the driver's seat 41 and facing forward, the left hand side is "left" and the right hand side is "right". The up-down direction is the vertical direction. The front-rear direction, the left-right direction, and the up-down direction are orthogonal to each other.

[0017] These directions are defined for convenience in order to make the description easier to understand, and the present invention is not limited by these directions. In the following, the seedling transplanter 1 may be referred to as the machine body.

[0018] The riding-type seedling transplanter 1 shown in Fig. 2 as the work vehicle according to the embodiment has an 8-row planting configuration, but such a configuration may be used for a rice transplanter with a different number of planting rows. As shown in Figs. 1 and 2, the seedling transplanter 1 has a seedling planting unit that takes seedlings from the seedling tank 53 and plants the seedlings in the field with a plurality of seedling planting devices 55, a seeding device that supplies seeds, or a working device 4 such as a rotary tiller that tills the field, which is provided so as to be able to move up and down via a lift link mechanism 3 on the rear side of the traveling vehicle body 2, and the main body portion of the fertilizer applicator 5 is arranged on the upper rear portion of the traveling vehicle body 2.

[0019] First, the main frame 15 that constitutes the traveling vehicle body 2 will be described. As shown in Fig. 3, the main frame 15 includes a front side beam frame 16 at the front of the machine body, a rear side beam frame 17 at the rear of the machine body, a central beam frame 18 provided between the front and rear of the front side beam frame 16 and the rear side beam frame 17, and the front side beam frame 16 and the central beam frame 18 are connected by a pair of left and right front side connecting frames 19, 19, and the central beam frame 18 and the rear side beam frame 17 are connected by a pair of left and right rear side connecting frames 20, 20.

[0020] Note that the front side beam frame 16, the center beam frame 18, and the rear side beam frame 17 have the left - right direction as the longitudinal direction, and the front side connecting frames 19 and the rear side connecting frames 20 have the front - rear direction as the longitudinal direction. The left - right intervals between the left and right front side connecting frames 19, 19 and the rear side connecting frames 20, 20 are set to be substantially the same. Also, the left - right lengths of the center beam frame 18 and the rear side beam frame 17 are configured to be longer than the left - right length of the front side beam frame 16. Since the left and right front side connecting frames 19, 19 and the rear side connecting frames 20, 20 are welded at the lower part of the center beam frame 18, the left and right front side connecting frames 19, 19 and the rear side connecting frames 20, 20 may be formed of an integral metal angle member.

[0021] In the space formed by the front side beam frame 16, the center beam frame 18, and the left and right front side connecting frames 19, 19, a transmission case 13 that transmits driving force to the left and right front wheels 10, 10, rear wheels 11, 11, working device 4, etc., and a hydrostatic transmission (HST) 14 that outputs the driving force supplied from the engine 30 to the transmission case 13 are provided. Then, at the rear part of the rear side beam frame 17, left and right lifting frames 21, 21 are provided so as to protrude rearward at an interval narrower than the left - right interval between the left and right rear side connecting frames 20, 20, and a rear support frame 22 is attached to the lower parts of the left and right lifting frames 21, 21.

[0022] On both the left and right sides of the rear support frame 22, rear wheel transmission cases 11a, 11a for driving the left and right rear wheels 11, 11 of the traveling vehicle body 2 are provided, and on the upper part of the rear support frame 22, left and right link frames 23, 23 for supporting the lifting link mechanism 3 are provided facing upward.

[0023] The lifting link mechanism 3 is configured by providing a pair of left and right lower link arms 24, 24 between the lower sides of the left and right link frames 23, 23 and between the left and right, providing a lifting cylinder 25 between the left and right lower link arms 24, 24, and providing an upper link arm 26 above the lifting cylinder 25. Note that the ends of the left and right lower link arms 24, 24, the lifting cylinder 25, and the upper link arm 26 on the side opposite to the traveling vehicle body 2 are attached to the front side of the body of the working device 4.

[0024] Furthermore, front wheel transmission cases 10a, 10a for transmitting power to the left and right front wheels 10, 10 of the traveling vehicle body 2 are respectively provided in front of the left and right ends of the central beam frame 18 and on the left and right outer sides of the left and right front side connection frames 19, 19. The left and right end portions of the central beam frame 18 and the rear side beam frame 17 are respectively connected by left and right extension frames 27, 27. The left and right extension frames 27, 27 have their longitudinal directions in the front-rear direction.

[0025] Also, a central connection frame 28 in the front-rear direction is provided at the lower parts of the central beam frame 18, the rear side beam frame 17, and the rear support frame 22. Front and rear support plates 29, 29 for supporting the engine 30 are provided between the front and rear of the central beam frame 18 and the rear side beam frame 17 and between the left and right rear side connection frames 20, 20.

[0026] Receiving plates 29a for receiving the engine 30 are respectively provided on both the left and right sides of the central connection frame 28 on the front and rear support plates 29, 29. Left and right auxiliary frames 31, 31 that pass below the rear side beam frame 17 and protrude rearward are provided on both the left and right sides of the front and rear support plates 29, 29, and the rear portions of the left and right auxiliary frames 31, 31 are connected by a rear portion auxiliary frame 32 in the left-right direction. Note that the rear end portions of the left and right auxiliary frames 31, 31 are connected to the left and right rear wheel transmission cases 11a, 11a.

[0027] As described above, the main frame 15 is configured. Among the main frame 15, the front-to-rear width from the front side beam frame 16 to the rear side beam frame 17, and the left-to-right width of the left and right front side connecting frames 19, 19 and the rear side connecting frames 20, 20 are covered by the floor step 33 on which the operator rides. The floor step 33 is integrally formed to improve strength or reduce the number of parts, or is configured to be divisible into the front side and the rear side, and the left side and the right side, respectively, to facilitate attachment and detachment.

[0028] In the above, as shown in FIG. 3, the peripheries of the left and right both ends of the central beam frame 18 and the rear side beam frame 17, and the left and right extension frames 27, 27 are not covered by the floor step 33 and are exposed. At this time, the floor step 33 may be enlarged to cover the entire main frame 15, but in order to share the floor step 33 among airframes with different sizes and the number of planting operation rows, left and right extension steps 34, 34 are respectively arranged on the left and right both sides of the floor step 33.

[0029] With the above configuration, since the main frame 15 is configured by connecting a plurality of frame structures, the strength is improved compared to the prior art. In addition, the central connecting frame 28 is arranged below the lower parts of the front and rear support plates 29, 29 on which the engine 30 is mounted, and by connecting the front and rear support plates 29, 29 to the left and right rear auxiliary frames 32, 32, the heavy engine 30 can be firmly held.

[0030] On the front side of the traveling vehicle body 2, as shown in FIGS. 1 and 2, there is provided a bonnet 39 having, at the upper part, a handle 35 for steering the airframe, a shift operation lever 36 for operating the continuously variable transmission 14 and the working device 4, a sub-shift operation lever 37 for operating a sub-shift switching device (not shown) for switching the traveling transmission of the traveling vehicle body 2, and a control panel 38 for operating each part of the airframe. A front cover 40 that can be opened and closed is provided on the front side of the bonnet 39, and inside the front cover 40, there are installed a fuel tank, a battery, and an interlocking mechanism (not shown) for rotating the lower sides of the left and right front wheels 10, 10 and the left and right front wheel transmission cases 10a, 10a for steering the handle 35.

[0031] In front of the front cover 40, a center mascot 70 is provided to display various information such as the working state of the working device 4, the reduction of working materials consumed during work, and the operation and non-operation of the automatic steering device 205 described later by lighting an LED or the like. The center mascot 70 is composed of, for example, a work display portion 71 disposed on the lower side of the machine body and on the rear side of the machine body in a side view, and an automatic straight-ahead display portion 72 disposed on the upper side of the machine body and on the front side of the machine body.

[0032] An engine cover 30a that covers the upper and side portions of the engine 30 is provided behind the bonnet 39 and above the engine 30, and a driver's seat 41 on which an operator sits is provided on the upper portion of the engine cover 30a.

[0033] Furthermore, behind the driver's seat 41, specifically, on the rear end side of the main frame 15, the fertilizer applicator 5 is loaded. The driving force of the fertilizer applicator 5 is transmitted by a fertilizer transmission mechanism 5a disposed from one side of the left and right rear wheel transmission cases 11a toward the fertilizer applicator 5.

[0034] In front of the transmission case 13, a front transmission shaft (not shown) that transmits power to the left and right front wheel transmission cases 10a, 10a is provided, and on the rear portion of the transmission case 13, left and right drive shafts 42, 42 that transmit power to the left and right rear wheel transmission cases 11a, 11a are provided. Side clutch mechanisms 43, 43 for engaging and disengaging the transmission to the left and right drive shafts 42, 42 are disposed on the upper side in the transmission direction than the left and right drive shafts 42, 42. When the steering wheel 35 is turned to operate the traveling vehicle body 2 to turn, the side clutch mechanism 43 located on the inner side of the turn is disengaged to stop the transmission to the rear wheel 11 on the inner side of the turn.

[0035] As shown in FIG. 3, left and right clutch engagement / disengagement shafts 44, 44 are provided vertically near the left and right centers on the rear side of the transmission case 13, and clutch engagement / disengagement arms 45, 45 facing outward of the machine body are provided at the upper portions of the left and right clutch engagement / disengagement shafts 44, 44, respectively. And at the lower front side of the driver's seat 41 and on one side of the left and right, side clutch pedals 43a, 43a for engaging and disengaging the left and right side clutch mechanisms 43, 43 are provided.

[0036] Also, as shown in FIGS. 1 and 2, a center float 62C that contacts the field surface and slides, and left and right side floats 62L, 62R are provided below the working device 4, and a leveling rotor 63 for leveling the unevenness of the field surface is provided in front of the center float 62C and the left and right side floats 62L, 62R on the front side of the machine body. The driving force to the leveling rotor 63 is transmitted by a leveling transmission shaft 65 provided in the rear wheel transmission case 11a on one side of the left and right. Further, a leveling clutch for engaging and disengaging the transmission to the leveling rotor 63 is provided in the rear wheel transmission case 11a on one side of the left and right.

[0037] A rotation potentiometer 64 (see FIG. 6) for detecting the rotation angle of the center float 62C is provided on the center float 62C. When the rotation angle of the rotation potentiometer 64 changes by a predetermined angle or more, it is determined that the depth of the field has changed, and the control device 100 expands and contracts the lifting cylinder 25 to rotate the lifting link mechanism 3 up and down, so that the vertical height of the working device 4, that is, the working position, corresponds to the depth of the field.

[0038] When performing operations such as seedling planting, seed sowing, or topdressing and weeding after the growth of seedlings using the working device 4 in the field, it is common to drive the traveling vehicle body 2 straight from one side of the field to the other side. However, when the wheels of the traveling vehicle body 2 face a direction deviated from the straight-ahead direction due to the unevenness of the plowed pan of the field and the viscosity of the topsoil, the vehicle body may gradually move in the deviated direction. Also, depending on the operator's driving skills, the traveling vehicle body 2 may not be aligned in the straight-ahead direction and may be moved in a direction deviated from the straight-ahead direction.

[0039] As a result, the working trajectories such as seedling planting, seeding, weeding, and top dressing become diagonal, and the areas where seedling planting and seeding can originally be carried out become empty spaces, which requires the operator to manually perform planting and seeding later, causing extra labor for the operator. Also, the row spacing for seedling planting and seeding becomes narrower than the row spacing of the working device 4, resulting in poor ventilation and the possible occurrence of pests and diseases. Alternatively, when performing operations in the subsequent processes after planting and seeding, such as weeding and top dressing operations, the seedlings may be crushed, leading to a decrease in yield, or the problem of reducing work efficiency may occur by operating so as not to crush the seedlings.

[0040] To solve these problems, it is conceivable to install a so-called automatic straight-ahead system that automatically steers the traveling vehicle body 2 and maintains a straight-ahead traveling posture without relying on the operator's hand.

[0041] First, as shown in FIGS. 1 and 2, an antenna frame 201 for mounting a GPS (GNSS) antenna 200 as a position information acquisition device is provided on the traveling vehicle body 2. The antenna frame 201 is composed of a front frame 201a in a portal shape when viewed from the front, which mounts the left and right bases on the left and right antenna stays 202, 202 provided on the front side of the main frame 15, and a rear frame 201b that extends from the left and right central portions of the front frame 201a toward the rear of the machine body and toward the left and right central portions on the rear side of the traveling vehicle body 2. It should be noted that the bonnet 39 and the driver's seat 41 are located behind the space portion of the portal-shaped front frame 201a.

[0042] Also, the vertical height of the antenna frame 201 is made the highest in the machine body. To prevent the operator from hitting their head while standing on the floor step 33 and to improve the reception accuracy, the upper end of the antenna frame 201 is positioned at about 2.5 to 3.5 m from the ground surface. As a result, the operator can easily move on the floor step 33, improving work efficiency, and the GPS antenna 200 can be separated upward from the ground surface, thereby improving the reception accuracy.

[0043] Near the connection part of the front frame 201a and the rear frame 201b, the GPS antenna 200 is mounted. Note that the connection part of the front frame 201a and the rear frame 201b is near the front and rear between the bonnet 39 and the driver's seat 41, and is near the central part in the front-rear direction of the traveling vehicle body 2.

[0044] As described above, since the mounting position of the GPS antenna 200 is near the central part in the front-rear and left-right directions of the machine body, the coordinates of the machine body obtained are less likely to deviate from the actual position of the machine body, the setting of the straight-ahead traveling position by the automatic straight-ahead system becomes appropriate, and the working accuracy is improved.

[0045] Also, since the driver's seat 41 is located behind the space part of the front frame 201a, it is possible to prevent the antenna frame 201 from blocking the operator's view, so the visibility is improved, the alignment before straight-ahead traveling becomes accurate, and the state of the field and obstacles in front of the machine body can be found earlier. Therefore, it is possible to switch to manual operation by the operator and suppress the deviation of the working position safely. The GPS antenna 200 is preferably one suitable for the area where the work is performed among the single-point positioning method, the DGPS (differential GPS) method, the RTK (real-time kinematic) method, etc.

[0046] However, if the ground height of the GPS antenna 200 fluctuates due to the influence of the inclination and vibration of the machine body, a coordinate position different from the actual machine body position is measured, the reception accuracy decreases, and there is a problem that the machine body travels in a direction deviated from straight-ahead.

[0047] To prevent this, as shown in FIG. 6, in addition to the GPS antenna 200, an IMU (inertial measurement unit) 203 is provided. The IMU 203 corrects the position coordinates obtained by the GPS antenna 200 to the control device 100 based on the difference in height from the ground surface to the GPS antenna 200 when the traveling vehicle body 2 is in an inclined posture and the height from the ground surface to the GPS antenna 200 when it is not inclined.

[0048] Note that the height from the ground surface to the GPS antenna 200 is determined by measuring the behavior such as the inclination of the traveling vehicle body 2 with a three-axis acceleration sensor and an angular velocity sensor built in the IMU 203.

[0049] In addition to this, an azimuth sensor 204 is provided to more surely cause the control device 100 to determine whether the traveling direction of the aircraft by the automatic straight-ahead system is correct. Note that the correction of the position coordinates at this time is as shown in S101 to S105 in FIG. 7. Thereby, since the route of the aircraft can be determined by the measured azimuth, the accuracy of straight-ahead traveling is further improved.

[0050] The position information acquired by the GPS antenna 200 is corrected by the control device 100 based on the information detected by the IMU 203 and the azimuth sensor 204. Then, the control device 100 compares the current position information with the previously acquired position information, and if the difference in the position information exceeds the allowable range, the left and right front wheels 10, 10 are steered in the left-right direction to return the aircraft to the straight-ahead traveling position.

[0051] An automatic steering device 205 is provided to rotate the steering wheel 35 with a steering actuator 206 in order to automate the steering of the left and right front wheels 10, 10 or the turning in place of a crawler or the like. As shown in S201 to S204 in FIG. 8, the automatic steering device 205 turns the steering wheel 35 left and right based on the difference between the X coordinate of the current position information calculated by the control device 100 and the X coordinate of the reference position information acquired previously, and varies the operating amount of the steering actuator 206 to direct the aircraft toward the straight-ahead traveling position. When the aircraft reaches the straight-ahead traveling position, the steering actuator 206 is stopped and the automatic steering of the steering wheel 35 is stopped.

[0052] Note that the steering actuator 206 is composed of an electric or hydraulic motor or a cylinder.

[0053] With the above configuration, the steering wheel 35 is automatically steered in accordance with the difference in the X coordinate of the calculated position information, and the airframe can be automatically aligned with the straight-ahead driving position. Therefore, it is possible to prevent the working position of the working device 4 from shifting in the left-right direction, and it is less likely that there will be areas in the field where no work is performed. As a result, there is no need to manually perform work later in areas where work was not done, reducing the labor of the operator.

[0054] In addition, since it is possible to prevent the working positions of the working strips in the previous process and the current working strip from overlapping, it is possible to prevent the excessive consumption of working materials such as seedlings, seeds, and fertilizers. This reduces the working cost and prevents the occurrence of poor growth due to the excessive supply of working materials.

[0055] Note that a tractor equipped with a tiller, a seedling transplanter, or a seeder travels to the field edge of the working strip and turns approximately 180 degrees to move to the next working strip. If the automatic straight-ahead system is operating during the turning travel, it may be determined that the airframe is displaced from the position where it should travel straight ahead, and the steering actuator 206 may be activated, possibly disturbing the turning trajectory. Therefore, the automatic straight-ahead system needs to be configured to turn off when the airframe is turned. Although it is also conceivable to configure the automatic straight-ahead system to turn off when the steering wheel 35 is turned, when the traveling direction of the airframe is significantly displaced due to the condition of the field or the operator operates the steering wheel 35 more greatly than a turning operation to avoid an obstacle, the automatic straight-ahead system turns off. As a result, the operator has to turn on the automatic steering system again during straight-ahead travel, increasing the operator's effort. In addition, there is a problem that the operator may not notice that the automatic straight-ahead system has turned off, and the airframe may travel with the working position displaced, resulting in a decrease in working accuracy.

[0056] In addition, it is conceivable to turn on the automatic straight - driving system by an operation of returning the steering wheel 35 from a turning operation to a straight - driving operation. However, when returning from a turn to a straight - driving operation, in order to align the aircraft body with the straight - driving position in the next working section, it is necessary to perform a fine steering operation of the steering wheel 35. If the automatic steering system is turned on during this operation, when the control device 100 determines that the aircraft body has deviated from the straight - driving position, the steering actuator 206 will operate, and there will be a problem that the position of the aircraft body cannot be aligned with the position where it should originally drive straight.

[0057] An automatic straight - driving system that can prevent the occurrence of such problems, drive the aircraft body straight in an appropriate direction, and operate in an appropriate section will be described with reference to FIGS. 6, 8 to 11. Note that the longitudinal position coordinates of the traveling vehicle body 2 are set as the Y - coordinate, and the position coordinates in the direction orthogonal to the longitudinal direction of the traveling vehicle body 2, that is, the left - right direction, are set as the X - coordinate.

[0058] First, the traveling vehicle body 2 is provided with an automatic straight - driving setting member 207 that acquires the coordinates of one side of the field, which is the starting point of automatic straight - driving, and the other side of the field, which is the end point of automatic straight - driving, and turns the automatic straight - driving system on and off. The automatic straight - driving setting member 207 is configured to mount at least one member that can be operated in at least two directions, such as the up - down direction, the left - right direction, the pushed - in state, and the returned state, or to mount two or more operation members.

[0059] In this embodiment, as the automatic straight - driving setting member 207, as shown in FIG. 4, a finger - up lever that can be operated in the up - down direction is mounted, but a toggle switch, a push switch, a joystick, etc. may also be used. As a result, the number of parts can be reduced, and for the operation of acquiring the reference positions (the first reference position A and the second reference position B) and the operation of turning the automatic steering device 205 on and off, the automatic straight - driving setting member 207 can be operated with one hand on the same side, improving the operability.

[0060] As shown in FIG. 4, when the automatic straight-ahead setting member 207 is operated in the first direction W1, which is upward of the aircraft in this embodiment, the GPS antenna 200 is acquired at the operated position, and the position coordinates calculated by the control device 100 using the detection results of the IMU 203 and the azimuth sensor 204 are recorded. Note that the operation of the automatic straight-ahead setting member 207 in the first direction W1 corresponds to the operation of the reference position acquisition member.

[0061] When the automatic straight-ahead setting member 207 is operated, as shown in S301 to S302 of FIG. 9, when there is no record of other position coordinates, the calculated position coordinates are recorded as the first reference point A, and when the first reference point A is already recorded, the calculated position coordinates are recorded as the second reference point B. When the automatic straight-ahead setting member 207 is operated when the first reference point A and the second reference point B are already recorded, no position coordinates are recorded.

[0062] Note that during work in the field, when automatic straight-ahead cannot be performed accurately, etc., it is necessary to reacquire the first reference point A and the second reference point B. Therefore, as shown in FIG. 10 (S401 to S406), at this time, if the automatic straight-ahead setting member 207 is operated in the first direction W1 for a predetermined time (for example, 2 to 3 seconds), it is preferable to set the recorded first reference point A and second reference point B to be deleted. Alternatively, a button for deleting the record (not shown) that deletes the first reference point A and the second reference point B when operated may be provided.

[0063] The first reference point A and the second reference point B, which are the reference positions for straight-ahead travel of the automatic straight-ahead system, have a smaller deviation in the X coordinate as the distance between them is closer. However, if the distance between the two points is short, approximate straight-ahead travel is possible without using automatic straight-ahead. Also, when the distance between the two points becomes short, a situation may occur where the operator accidentally touches the automatic straight-ahead setting member 207 and acquires the second reference point B.

[0064] In order to prevent the occurrence of such problems, when the second reference point B is obtained by operating the automatic straight-ahead setting member 207, if the distance from the position where the first reference point A is obtained is less than a predetermined distance, for example, less than 8 to 12 m, the control device 100 shall delete the second reference point B and not record it. After that, if the automatic straight-ahead setting member 207 is operated again and the distance from the position where the first reference point A is obtained is equal to or greater than the predetermined distance, the control device 100 shall record the second reference point B.

[0065] In addition, as shown in FIG. 11 (S501 to S505), when the steering wheel 35 is operated by a predetermined amount or more within a predetermined time without obtaining the second reference point B in a state where the first reference point A is obtained and the traveling vehicle body 2 is turned, the control device 100 deletes the recorded first reference point A. After that, when the automatic straight-ahead setting member 207 is operated in the first direction W1, the control device 100 records the position coordinates of that location obtained by the GPS antenna 200 as the first reference point A, and may be configured to prevent the line connecting the Y coordinate of the first reference point A and the Y coordinate of the second reference point B from becoming non-linear.

[0066] Thereby, the first reference point A and the second reference point B can be set at predetermined positions at one end and the other end of the field, for example, the position where the traveling vehicle body 2 starts to turn after finishing straight-ahead travel and the position where the working device 4 is lowered and straight-ahead travel is started after the turn is completed. The automatic straight-ahead system is activated at the position where the working device 4 is lowered and straight-ahead travel is performed, enabling highly accurate work with no lateral deviation of the working position with respect to the traveling direction.

[0067] In addition, it is possible to prevent the second reference point B from being actually set at a position different from the position to be set due to an operator's incorrect operation. Therefore, it is not necessary to re-obtain the first reference point A and the second reference point B in the next working condition, the number of working conditions using automatic straight-ahead can be increased, and the working accuracy in the field can be further improved.

[0068] In the operation strip where the operation is first performed after entering the field, since it is essential to operate the automatic straight-ahead setting member 207 in the first direction W1 at a predetermined position to obtain the above-described first reference point A and second reference point B, the operator operates the steering wheel 35 without using automatic straight-ahead to drive the vehicle body straight ahead.

[0069] As described above, when the first reference point A and the second reference point B are obtained by operating the automatic straight-ahead setting member 207, the reference line R connecting the Y coordinates of the first reference point A and the second reference point B becomes the reference line for automatic straight-ahead, and it is determined whether the X coordinate of the position coordinate of the vehicle body during travel matches the X coordinate of the reference line for automatic straight-ahead. If they do not match, the steering wheel 35 is automatically steered in the matching direction by the automatic steering device 205, thereby realizing automatic straight-ahead driving.

[0070] The above automatic straight-ahead driving is started by operating the automatic straight-ahead setting member 207 in the second direction W2, in this embodiment, downward toward the vehicle body, with the first reference point A and the second reference point B recorded. When the automatic straight-ahead setting member 207 is operated in the second direction W2, the control device 100 compares the Y coordinate of the position coordinate acquired by the GPS antenna 200 with the Y coordinate of the reference line R, activates the steering actuator 206 to rotate the steering wheel 35 in the left-right direction, and starts control to move the traveling vehicle body 2 to the position where it should drive straight ahead. Note that the operation of the automatic straight-ahead setting member 207 in the second direction W2 corresponds to the operation of the switching member.

[0071] This automatic steering control ends when the steering wheel 35 is operated to an angle at which the traveling vehicle body 2 is turned within a predetermined time, or when the automatic straight-ahead setting member 207 is operated in the second direction W2. The steering angle of the steering wheel 35 is detected by the steering wheel potentiometer 35a. Note that the automatic straight-ahead control may be configured to end when the traveling vehicle body 2 reaches a location that coincides with the Y coordinate of the first reference point A or the second reference point B.

[0072] As described above, the automatic straight travel control is terminated by turning the steering wheel 35 or reaching near the starting point of the turning travel at the edge of the field. Since the position where the traveling vehicle body 2 turns is close to the edge of the field, if the operator performs operations other than steering while leaving the automatic straight travel control, the turning operation will be delayed, the seedlings will be planted at an unexpected position, and the traveling vehicle body 2 will move to the edge of the field, requiring the vehicle to reverse to the position where it can turn, resulting in a problem of reduced work efficiency. Note that FIG. 12 is a schematic diagram showing the first reference position A, the second reference position B, the reference line R, and the target position and the current position of the machine body.

[0073] To prevent such problems, as shown in FIG. 6 and the like, a work detection sensor 209 for detecting the engagement (operation) and disengagement (stop) of the tilling clutch 63 to thereby detect the engagement and disengagement of the tilling rotor 63 is provided. When the work detection sensor 209 detects the engagement (operation) of the tilling rotor 63, the control device 100 acquires the target position coordinates (end reference position), which are the position coordinates (X coordinate and Y coordinate) of the traveling vehicle body 2. Note that the target position coordinates can be simultaneously held in at least two locations in the control device 100 or in a memory area associated with the control device 100.

[0074] Note that the acquisition of the target position coordinates (end reference position) by the work detection sensor 209 may be configured to be performed on the condition of the raising or lowering of the work device 4, the engagement or disengagement of the transmission to the work device 4, the start or end of the turning steering of the steering wheel 35, etc., instead of the engagement and disengagement of the tilling rotor 63.

[0075] Then, when operating the automatic steering device 205 to make the traveling vehicle body 2 travel straight automatically in the next work row after the work row where the position coordinates are acquired, the control device 100 sequentially calculates the distance from the Y coordinate of the current position coordinates acquired by the GPS antenna 200 to the Y coordinate of the target position coordinates acquired in the immediately preceding work row (the nearest work row). At this time, the control device 100 may be configured to correct the X coordinate of the target position coordinates to the X coordinate of the current position coordinates.

[0076] When the traveling vehicle body 2 reaches the notification position where the distance from the current position coordinates to the target position coordinates becomes a predetermined distance, for example, 8 to 12 m, it means that the traveling vehicle body 2 is approaching the edge of the field. To inform the operator that it is necessary to operate the automatic straight-ahead setting member 207 in the second direction W2 to end the automatic straight-ahead control, an alarm device 208 is configured to operate, such as a buzzer, a lamp, or a device that displays numerical values or characters on a screen.

[0077] Note that, as for displaying numerical values or characters on the alarm device 208, a configuration in which a display panel (not shown) is provided on the traveling vehicle body 2 or a configuration in which information is transmitted to an information terminal (such as a smartphone or a tablet) brought in by the operator for display is conceivable.

[0078] Also, in a work condition where the target position coordinates have not been acquired, since the distance between the traveling vehicle body 2 and the target position cannot be calculated, the operator needs to visually check the edge of the field and operate the automatic straight-ahead setting member 207 at a position where it is determined that automatic straight-ahead control is not required.

[0079] Regarding the distance from the current position coordinates to the target position coordinates, rear-wheel rotation sensors 210, 210 for detecting the rotation of the left and right drive shafts 42, 42 to the left and right rear wheels 11, 11 are provided. Based on the number of rotations detected by the rear-wheel rotation sensors 210, 210 from the position where the tilling rotor 63 is engaged, the control device 100 calculates the moving distance, calculates the distance from the moving distance to the Y coordinate position of the position where the tilling rotor 63 is engaged, and if it is within a predetermined distance, the alarm device 208 may be configured to operate.

[0080] However, even if the alarm device 208 operates, if the operator does not notice and end the automatic straight-ahead control, the traveling vehicle body 2 cannot be turned at an appropriate position. To address this, when the traveling vehicle body 2 travels forward without the automatic straight-ahead setting member 207 being operated in the second direction W2 for a predetermined distance (for example, 2 to 5 m) after the alarm device 208 operates, the control device 100 rotates the trunion shaft 14a of the continuously variable transmission 14 to decelerate the traveling vehicle body 2.

[0081] Alternatively, instead of the distance, when the traveling vehicle body 2 travels forward without the automatic straight-ahead setting member 207 being operated in the second direction W2 for a predetermined time (for example, 2 to 5 seconds) after the notification device 208 operates, the control device 100 reduces the output of the continuously variable transmission 14 and decelerates the traveling vehicle body 2.

[0082] The deceleration of the traveling vehicle body 2 described above is performed by operating an HST servo motor 211 that rotates the trunnion shaft 14a of the continuously variable transmission 14 via a trunnion arm (not shown) and rotating the trunnion shaft 14a to the deceleration side.

[0083] As a result, when approaching the field edge, the traveling speed of the traveling vehicle body 2 decreases, so that the operator can recognize that the turning position at the field edge is approaching, and turning travel can be performed along an appropriate trajectory. Therefore, the working device 4 can perform ground work repeatedly on the four sides of the outer periphery of the field, that is, on the so-called headlands, and it is possible to prevent excessive consumption of working materials (such as seedlings, fertilizers, and chemicals).

[0084] In addition, since the position where the leveling rotor 63 is turned on and the leveling work is started after turning can be adjusted to the position where the leveling work was completed before turning, it is possible to prevent the occurrence of a portion where the leveling work by the leveling rotor 63 is not performed and the occurrence of a portion where the ground work by the working device 4 is not performed. As a result, it is possible to prevent problems such as the planting depth of the seedlings being disturbed, the penetration of the fertilizer being different, and the traveling being disturbed at the portion where the leveling work was not performed, and it is not necessary for the operator to perform the work manually at the position where the ground work was not performed, thus reducing the labor of the operator.

[0085] Regarding the above automatic deceleration, if it is configured such that the traveling speed gradually decreases over time and is decelerated gently, it is possible to prevent a decrease in the ground work accuracy by the working device 4 and the leveling accuracy of the leveling rotor 63, and the operator from being shaken. Alternatively, if it is configured to perform sudden deceleration once or multiple times at predetermined time intervals after the start of automatic deceleration, the operator can easily notice the approach to the field edge due to the shaking of the traveling vehicle body 2.

[0086] Further, when the automatic straight-ahead control is canceled by operating the automatic straight-ahead setting member 207 within a predetermined time (second predetermined time) during which the automatic deceleration control is being performed, the control device 100 may be configured to maintain the traveling speed at that time. Thereby, since the work traveling does not stop, it is possible to promptly shift to the turning traveling at the field edge, and a decrease in work efficiency is prevented.

[0087] Alternatively, the control device 100 may be configured to operate the HST servo motor 211 of the continuously variable transmission 14 to rotate the trunnion shaft 14a toward the speed increasing side so as to shift to a preset traveling speed or the traveling speed at the time when the automatic deceleration is started. Since the traveling speed is automatically increased, there is no need for the operator to operate the speed change operation lever 36 to increase the traveling speed, and thus the operability is improved.

[0088] In addition to the operation of the notification device 208, it is expected that the traveling vehicle body 2 recognizes the field edge, specifically, the turning position near the field edge, by the automatic deceleration control of the traveling vehicle body 2. However, it is assumed that the operator is engaged in another work or the operator loses consciousness, etc., and may not notice the automatic deceleration of the traveling speed.

[0089] Therefore, the automatic deceleration control of the traveling vehicle body 2 is performed until the continuously variable transmission 14 enters a neutral state in which it does not increase or decrease the traveling speed in either forward or reverse. At this time, the engine 30 is not stopped. Thereby, the traveling vehicle body 2 can be stopped on the spot, so that it is possible to prevent the vehicle body from advancing until it contacts the field edge, that is, the so-called ridge, and the damage of the vehicle body and the distance for reversing the vehicle body to resume work can be suppressed.

[0090] When the traveling of the traveling vehicle body 2 automatically stops due to approaching the field edge, when the speed increase / decrease and forward / backward movement of the traveling vehicle body 2 are operated and the shift operation lever 36 is returned to the neutral position, the control device 100 enables the continuously variable transmission device 14 to accept the speed increase / decrease operation. Then, when the shift operation lever 36 is operated to the forward side, the traveling of the traveling vehicle body 2 is restarted. Naturally, when the sub-shift operation lever 37 is operated to the neutral position and the driving force is not transmitted to the traveling system, the traveling is not started until the sub-shift operation lever 37 is operated to the position where the traveling transmission is performed.

[0091] The first reference point A, the second reference point B, which are the reference for the above automatic straight-ahead control, and the reference line R connecting the first reference point A and the second reference point B are necessary when performing straight-ahead working travel from one end of the field to the other end and straight-ahead working travel from the other end of the field to one end.

[0092] However, although the working travel on the four sides of the field, so-called headlands, is straight-ahead working travel, there is one working side with a traveling direction different from the above straight-ahead working travel, and on that working side, even if the reference line R is used, automatic straight-ahead control cannot be performed.

[0093] Also, outside the field, when moving the machine body to the loading platform of a transport truck or the like for transfer or when storing it in a shed, etc., if the automatic straight-ahead setting member 207 is accidentally operated in the second direction W2 to make the automatic steering device 205 operable, when moving the machine body, the X coordinate of the reference line R and the X coordinate of the machine body will be inconsistent, and it will be determined that it is deviated from the straight-ahead traveling position, and the automatic steering device 205 may automatically steer the steering wheel 35. As a result, the course of the machine body will be at a position deviated from the course where it should originally travel, and extra labor will be required for the loading and storage work of the machine body.

[0094] As an example for preventing this, there is a method of erasing the first reference point A, the second reference point B, and the reference line R before the vehicle body exits the field. As shown in FIGS. 6 and 13 (S601 to S606), when the traveling vehicle body 2 travels on three sides including at least one side in the traveling direction orthogonal to the traveling direction of straight-ahead work traveling among the four sides of the field, it is determined that the ridging work has been performed, and the control device 100 causes the first reference point A, the second reference point B, and the reference line R to be deleted.

[0095] The traveling direction of the traveling vehicle body 2 on the ridged field is determined by the continuous change of the X-axis coordinate or the Y-axis coordinate among the position coordinates of the traveling vehicle body 2 acquired by the GPS antenna 200. Thereby, since the first reference point A, the second reference point B, and the reference line R can be deleted while the vehicle body is traveling in the field, even if the automatic straight-ahead setting member 207 is operated after exiting the field, automatic straight-ahead traveling will not be performed, and it is possible to prevent traveling in a direction deviated from the planned traveling direction, prevent a decrease in work efficiency, and improve work safety.

[0096] Further, when the vehicle body is moved to another field, since it is possible to prevent automatic straight-ahead control from being performed based on the reference line R not suitable for the field during work due to the first reference point A, the second reference point B, and the reference line R not being recorded, the accuracy of automatic straight-ahead traveling is improved.

[0097] When moving outside the field, the sub-shift operation lever 37 is operated to the traveling position so as to move to a transport truck in a short time or to move to a storage shed. A sub-shift position detection switch 37a for detecting the operation of the sub-shift operation lever 37 to this traveling position is provided, and when the sub-shift position detection switch 37a detects that the sub-shift operation lever 37 has been operated to the traveling position, the first reference point A, the second reference point B, and the reference line R may be configured to be deleted.

[0098] By performing the deletion of the first reference point A, the second reference point B, and the reference line R based on the operation of the sub-shift operation lever 37 to a traveling position not used in the field, when the first reference point A, the second reference point B, and the reference line R are not deleted during headland travel, they can be surely deleted. Thus, automatic straight travel control is not performed during the movement of the traveling vehicle body 2 or during the work in another field, and a decrease in work accuracy is prevented.

[0099] Also, since it is possible to prevent the first reference point A, the second reference point B, and the reference line R from being erroneously deleted in the field due to an erroneous operation of the sub-shift operation lever 37, it is prevented that automatic straight travel cannot be used in the work condition of reacquiring the first reference point A and the second reference point B, and the work accuracy is improved. Alternatively, when the traveling vehicle body 2 assumes a forward-upward inclination posture at a predetermined angle or more (for example, 10 to 15 degrees) using the IMU203 or the inclination sensor 212 that detects the inclination of the traveling vehicle body 2 in the front-rear and left-right directions, the control device 100 may be configured to delete the first reference point A, the second reference point B, and the reference line R.

[0100] When exiting the field, the traveling vehicle body 2 passing through the entrance / exit of the field assumes a forward-upward inclination posture at an angle that is substantially impossible during work. Therefore, when this inclination angle is detected, it can be determined that it is the time of exiting the field. Thereby, when the first reference point A, the second reference point B, and the reference line R are not deleted during headland travel, they can be surely deleted. Thus, automatic straight travel control is not performed during the movement of the traveling vehicle body 2 or during the work in another field, and a decrease in work accuracy is prevented.

[0101] Note that depending on the field and the content of the work, it is also conceivable to reverse the traveling vehicle body 2 and exit from the entrance / exit. Therefore, not only the forward-upward inclination angle but also a control configuration for deleting the first reference point A, the second reference point B, and the reference line R based on the rear-upward inclination angle may be used.

[0102] Also, when moving to another field to work after finishing work in a field, if the reference line R (i.e., the travel reference data) used in the work of the previous field remains at the start of work in the other field, for example, if the automatic steering function is accidentally turned on, the vehicle will travel in a direction not suitable for the field during work, resulting in a decrease in work efficiency. Also, since the direction in which the vehicle body travels is also a direction unintended by the operator, the operator will be forced to make extra operations.

[0103] To prevent this, when a predetermined condition is satisfied, the control device 100 automatically performs control to erase the reference line R. In the automatic erasure control of the reference line R to be described hereinafter, it is possible to detect the headland more accurately than the above-described automatic erasure control. Next, with reference to FIGS. 14 to 17, the automatic erasure of the reference line R will be described. FIGS. 14 to 17 are flowcharts showing control for automatically erasing the reference line (travel reference data). Note that the following control by the control device 100 is control when the vehicle body is performing ground work in the field.

[0104] As shown in FIG. 14, the control device 100 detects the automatic straight-ahead travel of the vehicle body (travel vehicle body 2) (step S701). When the vehicle body is in automatic straight-ahead travel (step S701: Yes), the control device 100 detects the travel state other than the straight-ahead travel of the vehicle body by the detection means (step S702). When the control device 100 detects the travel state other than the straight-ahead travel of the vehicle body by the detection means (step S702: Yes), the control device 100 performs control to erase the acquired reference line R (step S703).

[0105] In the process of step S701, when the control device 100 does not detect the automatic straight-ahead travel of the vehicle body (step S701: No), this process is repeated until the automatic straight-ahead travel is detected. Also, in the process of step S702, when the control device 100 does not detect the travel state other than the straight-ahead travel of the vehicle body (step S702: No), this process is repeated until the travel state other than the straight-ahead travel is detected.

[0106] According to such a configuration, when a traveling state set other than the straight traveling of the aircraft is detected by the detection means, the reference line R is erased, so that the reference line R of the previous field is not used in the work in other fields. Therefore, it is possible to prevent the automatic steering from acting in a direction unsuitable for the field during work or in a direction unintended by the operator. Thereby, workability can be improved, and the occurrence of extra operations can be prevented to achieve labor saving.

[0107] Further, for example, the control device 100 detects a traveling state other than the straight traveling of the aircraft by detecting the deviation angle of the aircraft from the reference line R. In this case, when the detection means detects a deviation angle of a predetermined value (for example, 45 degrees) or more from the reference line R, the control device 100 determines it as the above-described traveling state.

[0108] In this case, as shown in FIG. 15, when the aircraft is in the automatic straight traveling state (step S801: Yes), the control device 100 detects, by the detection means, a deviation angle equal to or more than a predetermined value with respect to the reference line R (step S802). When the control device 100 detects, by the detection means, a deviation angle equal to or more than a predetermined value with respect to the reference line R (step S802: Yes), the control device 100 performs control to erase the acquired reference line R (step S803).

[0109] In the process of step S801, when the control device 100 does not detect the automatic straight traveling of the aircraft (step S801: No), this process is repeated until the automatic straight traveling is detected. Further, in the process of step S802, when the control device 100 does not detect a deviation angle equal to or more than a predetermined value (step S802: No), this process is repeated until a traveling state other than the straight traveling is detected.

[0110] Further, the control device 100 may also erase the first reference position A and the second reference position B in addition to the reference line R acquired in the field.

[0111] In addition, as the detection means for detecting the deviation angle of the aircraft body exceeding a predetermined value from the reference line R, in addition to the means for determining by calculating the traveling route from the position information acquired by the GPS antenna 200, an azimuth sensor 204, an inclination sensor 212 (see FIG. 6), etc. can be used.

[0112] According to such a configuration, by detecting the deviation angle of the aircraft body exceeding a predetermined value with respect to the reference line R, for example, it is possible to recognize the operation of planting the outer edge in the field, which is the final process of the planting operation in the field, so-called headland planting operation. By recognizing the headland planting operation, it can be seen that straight-ahead traveling of the aircraft body in the field during the operation is no longer necessary. Therefore, by erasing the reference line R, it is possible to prevent the automatic steering from acting in a direction not suitable for the field during operation or in a direction unintended by the operator when moving to another field or working in another field, and the workability can be improved. In addition, since it is not necessary to manually erase the reference line R, the labor related to the reference line R can be saved. Thereby, the operability can be improved.

[0113] Further, in addition to the traveling state of the aircraft body, when the aircraft body is automatically traveling straight, the working state of the working device 4 may be detected (recognized) to erase the reference line R. As shown in FIG. 16, the control device 100 detects the automatic straight-ahead traveling of the aircraft body (step S901). When the aircraft body is automatically traveling straight (step S901: Yes), the control device 100, when detecting a deviation angle of the aircraft body exceeding a predetermined value with respect to the reference line R by the detection means (step S902: Yes), detects the working state set as the working state of the working device by the detection means (step S903). When detecting the working state set as the working state of the working device 4 by the detection means (step S903: Yes), the control device performs control to erase the acquired reference line R (step S904).

[0114] In addition, in the process of step S901, when the control device 100 does not detect the automatic straight running of the aircraft (step S901: No), this process is repeated until the automatic straight running is detected. Also, in the process of step S902, when the control device 100 does not detect a deviation angle equal to or greater than a predetermined value (step S902: No), this process is repeated until a deviation angle equal to or greater than the predetermined value is detected. Further, in the process of step S903, when the control device 100 does not detect the working state of the working device 4 (step S903: No), this process is repeated until the working state is detected.

[0115] According to such a configuration, by detecting the working state of the working device 4 (the headland planting work), it is possible to recognize the headland planting work of planting the outer edge in the field, which is the final process of the planting work in the field. By recognizing the headland planting work, it can be seen that the straight running of the traveling vehicle body 2 in the field during work is no longer necessary. Therefore, by erasing the reference line R, it is possible to prevent the automatic steering from acting in a direction not suitable for the field during work or in a direction unintended by the operator when moving to another field or working in another field, and the workability can be improved. Also, since there is no need to manually erase the reference line R, the labor required for erasing the reference line R can be saved. Thereby, the operability can be improved.

[0116] Further, the control device 100 may detect (recognize) the working state of the working device 4 and then, when detecting that the aircraft is traveling at or above a predetermined value, erase the reference line R. As shown in FIG. 17, the control device 100 detects whether the aircraft is in automatic straight running (step S1001). When the aircraft is in automatic straight running (step S1001: Yes), the control device 100, if a deviation angle equal to or greater than a predetermined value with respect to the reference line R is detected by the detection means (step S1002: Yes), detects the working state set as the working state of the working device by the detection means (step S1003). When the control device 100 detects the working state set as the working state of the working device 4 by the detection means (step S1003: Yes), it detects continuous running of the aircraft equal to or greater than a predetermined value (for example, 5 m) (step S1004). When the control device 100 detects continuous running of the aircraft equal to or greater than a predetermined value (step S1004: Yes), it performs control to erase the acquired reference line R (step S1005).

[0117] In the process of step S1001, if the control device 100 does not detect the automatic straight running of the aircraft (step S1001: No), this process is repeated until automatic straight running is detected. Also, in the process of step S1002, if the control device 100 does not detect a deviation angle equal to or greater than a predetermined value (step S1002: No), this process is repeated until a deviation angle equal to or greater than a predetermined value is detected. Also, in the process of step S1003, if the control device 100 does not detect the working state of the working device 4 (step S1003: No), this process is repeated until the working state is detected. Also, in the process of step S1004, if the control device 100 does not detect running of the aircraft equal to or greater than a predetermined value (step S1004: No), this process is repeated until running equal to or greater than a predetermined value is detected.

[0118] Note that, as the detection means for detecting running of the aircraft equal to or greater than a predetermined value, a rear wheel rotation sensor 210 (see FIG. 6) or the like can be used.

[0119] Further, the detection means detects the working state of the working device 4 by turning on and off the work detection sensor 209 (see FIG. 6). In this case, as the detection means for detecting the working state of the working device 4, for example, it is preferable to be a planting clutch on / off sensor that detects the on / off of the planting clutch. By the planting clutch on / off sensor turning on, it is possible to recognize that the above-described working state is a state where the headland planting work has started.

[0120] Further, when the machine body is in automatic straight running, the control device 100 detects the running state other than the straight running of the machine body by the detection means, and then, when the detection means detects the working state set as the working state of the working device 4, the acquired reference line R may be erased.

[0121] According to such a configuration, by detecting the working state of the working device 4 and detecting the running of the machine body at a predetermined value or more, it is possible to more reliably recognize the headland planting work of planting the outer edge in the field, which is the final process of the planting work in the field. By recognizing the headland planting work, it can be understood that the straight running of the machine body in the working field is no longer necessary. Therefore, by erasing the reference line R, it is possible to prevent the automatic steering from acting in a direction not suitable for the working field or in a direction unintended by the operator during the movement to another field or during the work in another field, and the workability can be improved. Further, since it is not necessary to manually erase the reference line R, the labor for erasing the reference line R can be saved. Thereby, the operability can be improved.

[0122] Further, when the control device 100 detects the deviation angle of the machine body from the reference line R, when it detects the working state of the working device 4, or when it detects both of these, it erases the running distance set for detecting the running at a predetermined value or more. Thereby, it is possible to prevent malfunction in the work after erasing the reference line R.

[0123] Further, when the control device 100 erases the reference line R, the notification device 208 (see FIG. 6) may be controlled to emit a notification sound for a predetermined time (about 2 seconds), for example. Thereby, the operator can recognize that the reference line R has been erased. Further, when the control device 100 erases the reference line R, for example, it may be controlled to display characters or the like on the monitor. Thereby, the operator can recognize that the reference line R has been erased.

[0124] Note that although the working device 4 is configured to be able to perform seedling planting and seeding simultaneously in a plurality of rows, a plurality of partial row clutches (also referred to as ridge clutches) for turning on and off the operation of the device for each working row are provided, and when stopping the drive of a part of all the working rows of the working device 4 and performing the work with only the remaining part of the working rows, based on detecting that a part of the partial row clutches is in the off state by the detection means, it may be configured to erase the reference line R. The detection means in such a configuration may be configured to detect the off state of the partial row clutch in addition to the detection function of the detection means described above.

[0125] Also, with reference to FIG. 18, another example of the work vehicle (seedling transplanter) will be described. FIG. 18 is a left side view showing another example of the work vehicle (seedling transplanter). As shown in FIG. 18, the seedling transplanter according to another example includes a back camera 400 and a monitor (tablet monitor) 401 instead of or in addition to a rearview mirror or the like. The back camera 400 is provided on the rear frame 201b of the antenna frame 201 to which the GPS antenna 200 is attached. The monitor 401 is provided on the front frame 201a of the antenna frame 201.

[0126] According to such a configuration, in addition to checking the rear of the machine body, it is possible to check the planting marks behind the machine body in the field and the straight-ahead state of the machine body. Further, by processing the image captured by the back camera 400, it is possible to recognize continuous missing plants behind the machine body. Note that, for example, when there are continuous missing plants, the notification device 208 (see FIG. 6) may be made to emit a notification sound. Thereby, the operator can recognize that continuous missing plants have occurred.

[0127] In addition, the seedling transplanter according to another example is provided with a seedling reduction switch 403 for detecting a decrease in the loaded seedlings in the working device (planting device) 4. When the seedling reduction switch 403 detects a decrease in seedlings during the seedling planting operation while the machine body is automatically traveling straight, for example, the control device 100 (see FIG. 6) controls the HST (electric HST) 14 to automatically decelerate the machine body. According to such a configuration, the machine body can be safely refilled with seedlings at a safe speed (for example, a speed of 0.3 m / s or less).

[0128] In addition, the seedling transplanter according to another example detects the rolling of the machine body by, for example, a gyro sensor in the GPS antenna 200. When the rolling of the machine body exceeds a predetermined value due to unevenness of the field or the like during the seedling planting operation while the machine body is automatically traveling straight, for example, the control device 100 controls the HST (electric HST) 14 to automatically decelerate the machine body to a predetermined speed (for example, 0.5 m / s). According to such a configuration, the straight traveling stability of the machine body can be improved.

[0129] Also, as shown in FIGS. 3, 4, 5A, and 5B, even when the traveling vehicle body 2 is automatically traveling straight by the automatic steering device 205, when replenishing the working materials consumed by the working device 4 or the like, or when some problem occurs in the machine body or the field, etc., the operator needs to stop the traveling. This traveling stop operation can be achieved by operating the shift operation lever 36 to the neutral position to neutralize the continuously variable transmission 14, stepping on the brake pedal to apply the brake, or stepping on the side clutch pedal 43a to disengage the side clutch mechanism 43.

[0130] Even when the traveling of the traveling vehicle body 2 is stopped by any of the above methods, the control device 100 is configured not to stop the automatic steering device 205. As a result, when the traveling stop is released by, for example, operating the shift operation lever 36 forward or releasing the operations of the brake pedal and the side clutch pedal 43a, the machine can immediately resume automatic straight traveling, preventing a decrease in work efficiency.

[0131] However, if the steering wheel 35 is manually steered while the vehicle is stopped, or if the automatic steering device 205 is activated and the steering wheel 35 is automatically steered, the traveling direction at the restart of the automatic straight-ahead driving may deviate from the traveling direction at the stop, and the traveling direction of the traveling vehicle body 2 may not be straight. In particular, when the traveling vehicle body 2 is stopped, the position coordinates acquired by the GPS antenna 200 are easily affected by the rotation of the earth, the revolution of GPS satellites, etc., and may acquire position coordinates different from the actual position where the traveling vehicle body 2 exists, and are easily misrecognized as being at a position away from the reference line R.

[0132] To prevent this, a lever potentiometer 36a for detecting the operation position of the shift operation lever 36 and a depression detection switch 213 for detecting the depression operation of the brake pedal and the clutch pedal are provided. When an operation for stopping the traveling is detected during the automatic straight-ahead driving, the control device 100 is configured not to reflect the steering operation of the steering wheel 35 or to keep the steering wheel 35 from moving.

[0133] The configuration of not reflecting the steering operation of the steering wheel 35 means that even if the X coordinate of the position coordinates of the traveling vehicle body 2 at the time of stopping deviates from the X coordinate of the reference line R by a predetermined value or more, the steering actuator 206 is not activated. Also, the configuration of keeping the steering wheel 35 from moving means increasing the operating torque of the steering actuator 206 to put it in a steering wheel locked state.

[0134] With the above configuration, it is possible to prevent the traveling direction from deviating after the restart of traveling, so that the work traveling is performed in a straight line and the work accuracy can be improved.

[0135] The steering wheel 35 is automatically steered by the steering actuator 206 during the automatic straight-ahead driving. However, in situations where the condition of the field on the travel route is not suitable for the automatic straight-ahead driving (rough, deep field depth, etc.) or there are obstacles, it is necessary to take an avoidance action by manual operation. The steering operation of the steering wheel 35 by the steering actuator 206 is performed according to the following configuration. An input gear 352 is provided at the lower part of the steering wheel shaft 351 that rotates in conjunction with the steering operation of the steering wheel 35, and an output gear 353 is provided on the steering actuator 206.

[0136] The input gear 352 and the output gear 353 are installed inside a steering gear case 354 disposed below the steering wheel 35 and the steering actuator 206. And a relay gear 355 for changing the transmission ratio and transmitting the driving force is provided between the input gear 352 and the output gear 353.

[0137] The gear ratios of the input gear 352, the output gear 353, and the relay gear 355 are set to gear ratios that increase the torque by manual operation even when the steering actuator 206 is operating, so as to prevent interference with the manual operation of the steering wheel 35. Thereby, even during automatic straight running, it is possible to prevent an increase in the force required for manual operation of the steering wheel 35, so that the operability is improved, and it is possible to surely avoid fields and obstacles in a state that may affect running, so that the work safety is ensured.

[0138] In addition, in the seedling transplanter 1, a GNSS unit incorporating a GPS antenna 200 (see FIG. 1) is disposed on the traveling vehicle body 2. The GNSS unit can acquire position information on the earth at predetermined intervals by acquiring GNSS coordinates at predetermined time intervals with the GPS antenna 200. Further, in addition to the GPS antenna 200, the GNSS unit incorporates, for example, an inertial navigation device using a gyro sensor and an acceleration sensor, and a control board for controlling these.

[0139] FIGS. 19A and 19B are explanatory views of the antenna frame 201. Note that FIG. 19A shows the front of the seedling transplanter 1, and FIG. 19B shows the left side surface of the seedling transplanter 1. Further, FIG. 20A is a front view of the antenna frame 201. FIG. 20B is a perspective view of the antenna frame 201. FIG. 20C is a perspective view of the antenna frame 201 from below.

[0140] As shown in FIGS. 19A and 19B, the GNSS unit incorporating the GPS antenna 200 is attached to the top of the antenna frame 201 whose base end is connected to the front end side of the traveling vehicle body 2 so as to be positioned directly above the axle 10b of the front wheel 10. The height of the antenna frame 201 in the normal state is set to a height such that even when a standard average male stands up on the floor step 33, it does not interfere with the head.

[0141] As shown in FIGS. 20A to 20C, the antenna frame 201 is composed of lower parts of the left and right front frames 201a (front lower frames 201aa), upper parts of the front frames 201a (front upper frames 201ab), an upper L-shaped frame 201c, and a rear frame 201b.

[0142] A pair of brackets 201e, 201e are provided at the base ends of the left and right front lower frames 201aa, 201aa, and the front lower frame 201aa is attached to the bumper 500 of the traveling vehicle body 2 via such brackets 201e, 201e.

[0143] The front upper frame 201ab is a substantially U-shaped frame in plan view having left and right vertical frames 2011, 2012 whose base ends are rotatably connected to the left and right front lower frames 201aa, 201aa via rotation connectors 201f, 201f respectively.

[0144] As shown in FIGS. 20A to 20C, the left and right rotation connectors 201f, 201f are connected and fixed by a knob bolt 201g, and a reinforcing frame 201h (see FIG. 19B) is spanned between the rotation connectors 201f, 201f and the front cover 40 (see FIG. 19B). In this way, rattling of the front lower frames 201aa, 201aa and the left and right vertical frames 2011, 2012 is prevented with a simple configuration.

[0145] The left and right front lower frames 201aa, 201aa are obliquely erected inward so that the upper end sides do not contact the front cover 40 as shown in FIG. 19A. Therefore, a space is formed between the control unit 41 and the spare seedling platforms 501, 501 arranged on the left and right sides of the machine body, for example, a space large enough for the operator M to move between the front of the machine body and the floor step 33.

[0146] And a GNSS unit (GPS antenna 200) is disposed on the aluminum block 201i spanned between the upper parts of the left and right vertical frames 2011, 2012. In this way, by interposing the aluminum block 201i between the GNSS unit and the steel pipe antenna frame 201, the reception sensitivity is improved compared to directly attaching to the GPS antenna 200.

[0147] The upper L-shaped frame 201c has its tip connected to the rear end of the front upper frame 201ab, and wiring such as a harness extending from the GNSS unit is routed along the upper L-shaped frame 201c.

[0148] The rear frame 201b has its lower end connected to the rear step at the rear part of the driver's seat 41. Storage hoppers 5b of the fertilizer applicator 5 are respectively arranged on the left and right behind the driver's seat 41. Since the rear frame 201c is positioned between the left and right storage hoppers 5b, there is no interference when opening and closing the storage hoppers 5b.

[0149] In this way, the antenna frame 201 for disposing the GNSS unit is connected to the bumper 500 and the front cover 40 at the front side and to the rear step at the rear side, and is supported at three points for structural stability. Therefore, it can be attached to the traveling vehicle body 2 in a very stable state.

[0150] At the upper end of the rear frame 201b, a connecting portion 201j is provided for detachably connecting the other end of the upper L-shaped frame 201c, and the upper L-shaped frame 201c is detachably connected. The connecting portion 201j may be constituted by, for example, pin insertion holes (not shown) respectively formed at the connecting ends of the upper L-shaped frame 201c and the rear frame 201b, and a fastening pin (not shown) that can be inserted into and removed from such pin insertion holes. In this way, the upper L-shaped frame 201c and the rear frame 201b can be detachably connected with a simple configuration.

[0151] In this way, by detaching the upper L-shaped frame 201c from the rear frame 201b and, as shown in Fig. 20B, by a simple operation of rotating the front upper frame 201ab and the upper L-shaped frame 201c downward to the rear with respect to the front lower frames 201aa, 201aa by the rotary connectors 201f, 201f, the height of the antenna frame 201 can be reduced as shown in Fig. 19B.

[0152] Therefore, for example, when transporting the seedling transplanter 1 or storing it in a shed or the like, when the thickness of the GNSS unit becomes a height obstacle, the overall vehicle height can be reduced without removing the GNSS unit.

[0153] Also, as a configuration for rotating the antenna frame 201 (the front upper frame 201ab and the upper L-shaped frame 201c), since a simple configuration with the rotary connectors 201f is adopted, an increase in cost can be suppressed, and rattling of the entire antenna frame 201 can be minimized. Moreover, it has the convenience of being able to perform the rotation operation in one action.

[0154] Also, as shown in Fig. 19B, a frame receiver 201k formed in a substantially Y shape is provided near the upper end of the rear frame 201b. Therefore, when folding the antenna frame 201 to reduce the height, the upper L-shaped frame 201c can be stably held by locking it to the frame receiver 201k.

[0155] Further, as shown in FIGS. 20A and 20B, the upper portions of the front frames 201a, 201a of the antenna frame 201, i.e., the front upper frames 201aa, 201aa, are formed so that the interval becomes narrower in a front view toward the upper L-shaped frame 201c on the tip side. Thereby, the strength of the antenna frame 201 is increased.

[0156] In addition, the seedling transplanter 1 includes a monitor 300 in the control unit for notifying the operator of the above-described automatic straight-ahead state. FIG. 21 is an explanatory diagram of the monitor 300. The monitor 300 is provided with a straight-ahead assist lamp 301 that lights up when the machine body performs automatic straight-ahead running, an A-point lamp 302, and a B-point lamp 303. The monitor 300 notifies the operator of various information regarding the automatic straight-ahead state based on the display modes of the three lamps 301, 302, and 303. Therefore, the monitor 300 can be configured simply and inexpensively.

[0157] In the monitor 300, for example, when the orientation of the machine body is shifted to the right side, the A-point lamp 302 blinks. By blinking the A-point lamp 302, the operator is prompted to turn the steering wheel 35 (see FIG. 1) to the left. Further, in the monitor 300, for example, when the orientation of the machine body is shifted to the left side, the B-point lamp 303 blinks. By blinking the B-point lamp 303, the operator is prompted to turn the steering wheel 35 to the right. In this way, by making the display modes of the A-point lamp 302 and the B-point lamp 303 the same as those of a direction indicator, the direction in which the operator should turn the steering wheel 35 can be clearly conveyed.

[0158] Further, in the monitor 300, when the machine body is in a state where automatic straight-ahead running is possible, both the A-point lamp 302 and the B-point lamp 303 light up. Also, when entering automatic straight-ahead running, for example, when the tilling rotor 63 is off, automatic straight-ahead running cannot be entered. In this case, for example, a notification sound (warning sound) is emitted from a notification device 208 (see FIG. 6), and the central straight-ahead assist lamp 301 blinks, for example, twice. By such a display mode, the operator is notified that automatic straight-ahead running is not possible. Therefore, the monitor 300 can be configured simply and inexpensively.

[0159] Also, in the monitor 300, when the vehicle body is in a state where it can automatically drive straight, both the point A lamp 302 and the point B lamp 303 light up. Further, when entering the automatic straight-ahead driving, for example, in the case of poor GPS reception by the GPS antenna 200, the automatic straight-ahead driving cannot be entered. In this case, for example, an alarm sound (warning sound) is emitted from the notification device 208 (see FIG. 6), and the central straight-ahead assist lamp 301 blinks, for example, three times. By such a display mode, the operator is notified that the automatic straight-ahead driving is not possible. For this reason, the monitor 300 can be configured simply and inexpensively. Also, by changing the number of blinks of the straight-ahead assist lamp 301 from that at other times of warning, the warning content can be notified to the operator by the display mode.

[0160] Also, a GPS lamp 304 is provided on the monitor 300. The GPS lamp 304 has three display lamps and changes the number of display lamps according to the GPS reception state. In the monitor 300, the operator is notified of the GPS reception state by such a display mode. For this reason, it is possible to prevent automatic straight-ahead driving in a state of poor GPS reception. Note that each of the lamps 301, 302, 303, 304 and the notification device 208 described above is controlled by the control device 100 (see FIG. 6).

[0161] Further effects and modifications can be easily derived by those skilled in the art. For this reason, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described as above. Therefore, various changes can be made without departing from the spirit or scope of the general inventive concept defined by the appended claims and their equivalents.

Explanation of Reference Numerals

[0162] 1 Work vehicle (seedling transplanter) 2 Traveling vehicle body 35 Steering wheel (steering member) 100 Control device 200 GPS antenna (position information acquisition device) 205 Automatic Steering Device (Automatic Straight-Ahead Device) A First Reference Position B Second Reference Position

Claims

1. A steering member for steering the traveling vehicle body; A position information acquisition device for acquiring position coordinates of the traveling vehicle body; In a work vehicle including an automatic driving device that operates the steering member to automatically drive the traveling vehicle body, and a control device that controls each part, A first reference position can be registered at one point in the field and a second reference position can be registered at another point in the field, a line connecting the first reference position and the second reference position is driving reference data serving as a reference for driving; An operation unit for turning on and off the automatic driving is provided, the operation portion is a lever member, When the driving reference data is registered, the automatic driving is turned on when the lever member is operated in a first direction, A work vehicle characterized in that, when registering the second reference position, if the distance from the position where the first reference position was obtained is less than a predetermined distance, the second reference position is not registered.

2. 2. The work vehicle according to claim 1, wherein when the lever member is operated in a second direction for a predetermined period of time, the line connecting the registered first reference position and the second reference position is deleted.

3. A work device is attached to the traveling vehicle body and performs work in a field, The work vehicle according to claim 1 or 2, characterized in that when the position information acquisition device recognizes that headland work, which is the final step of work in a field, is being performed, the line connecting the registered first reference position and second reference position is deleted.

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