Work vehicle

Abstract

To provide a working vehicle which has high work efficiency by setting a reset turning path in the case where a turning path along which the working vehicle is traveling is deviated from a set turning path by a prescribed distance or longer.SOLUTION: A set route consists of a set circulating path (72A) along which the working vehicle is caused to circulate clockwise or counterclockwise, set straight paths (72B) along which the working vehicle is caused to travel straight, and set turning paths (72C) along which the working vehicle is caused to turn. If a turning path measured by a positioning unit, along which the working vehicle is traveling, is deviated from the set turning path (72C) by a prescribed distance or longer, a radius (R1) is set to be longer than a turning radius (R) of the set turning path (72C).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a work vehicle that automatically travels along a set path in a field.

Background Art

[0002] In conventional work vehicles, when the traveling turning path deviates from a set turning path by a predetermined distance or more, during the traveling turn of the work vehicle, a switching of the drive mode such as from two-wheel drive to four-wheel drive and a switching of the traveling direction such as from forward to reverse are performed. (Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology of Patent Document 1, when a work implement such as a manure spreader that spreads compost is connected to the PTO shaft of the work vehicle, the path during reverse travel cannot be determined to be a predetermined path, and there is a problem that the work efficiency is low because the reverse work takes time.

[0005] Therefore, the present invention provides a work vehicle with high work efficiency by setting a re-set turning path formed from an arc having a predetermined radius when the traveling turning path of the work vehicle deviates from a set turning path by a predetermined distance or more.

Means for Solving the Problems

[0006] The present invention that solves the above problems is as follows. That is, the invention according to claim 1 is a work vehicle including a controller (50) that automatically drives a work vehicle along a set path (72) set in a field, and a positioning unit (20) that measures the travel path of the work vehicle. The set path (72) is formed by a set circular path (72A) for circulating the work vehicle clockwise or counterclockwise, a set straight path (72B) for making the work vehicle go straight, and a set turning path (72C) for turning the work vehicle. When the travel turning path of the work vehicle measured by the positioning unit (20) deviates from the set turning path (72C) by a predetermined distance or more, Continuously for a predetermined number of times a first circle (76A) having a predetermined radius (R1) that contacts the work end side of the end portion of the travel straight path of the work vehicle, a third circle (76C) having a predetermined radius (R1) that contacts the work unfinished side of the start portion of the set straight path (72B) adjacent to the travel straight path, and a second circle (76B) having a predetermined radius (R1) that contacts the first circle (76A) and the third circle (76C) are formed. A first re-setting turning path (77A) that reaches the first contact point (S1) of the first circle (76A) and the second circle (76B) along the arc on the work unfinished side in the first circle (76A) from the end portion of the travel straight path, a second re-setting turning path (77B) that reaches the second contact point (S2) of the second circle (76B) and the third circle (76C) along the outer arc in the second circle (76B) from the first contact point (S1), and a third re-setting turning path (77C) that reaches the start portion of the set straight path (72B) along the arc on the work end side in the third circle (76C) from the second contact point (S2) are set. The radius (R1) is set to be larger than the turning radius (R) of the set turning path (72C). , set the interval (W) between the set straight path (72B) and the adjacent set straight path (72B) to a length obtained by subtracting a preset overlap width (W2) from the working width (W1) of the working machine connected to the PTO shaft (6) of the work vehicle, set the predetermined radius (R1) to a length obtained by adding the overlap width (W2) to the turning radius (R), and when the number is less than the predetermined number of times, a first reset straight path (75A) from the first point (P1) which is the end of the traveling turning path to the second point (P2) on the set straight path (72B), and a second reset straight path (75B) from the second point (P2) to the start of the set straight path (72B) are set The work vehicle is characterized by the above.

[0007]

[0008] Claim 2 The invention according to the description provides a deviation determination line (73) at a position facing the second re-setting turning path (77B) in the set circular path (72A). When the second re-setting turning path (77B) extends outside the deviation determination line (73), the automatic travel of the work vehicle is stopped. Claim 1 The work vehicle according to the description.

[0009] Claim 3 The invention described in the claim is the work vehicle described in the claim formed by the positioning unit (20), a positioning satellite (21), a base station (22), and a mobile station (26) provided on the work vehicle. 1 or 2 It is the work vehicle described in the claim.

Effect of the Invention

[0010] According to the invention described in claim 1, the set route (72) is formed from a set circular route (72A) for circulating the work vehicle clockwise or counterclockwise, a set straight route (72B) for moving the work vehicle straight, and a set turning route (72C) for turning the work vehicle. When the traveling turning route of the work vehicle measured by the positioning unit (20) deviates from the set turning route (72C) by a predetermined distance or more, a first circle (76A) having a predetermined radius (R1) that contacts the work completion side at the end of the traveling straight route, a third circle (76C) having a predetermined radius (R1) that contacts the work unfinished side at the start of the set straight route (72B) adjacent to the traveling straight route, and a second circle (76B) having a predetermined radius (R1) that contacts the first circle (76A) and the third circle (76C) are formed. A first re-setting turning route (77A) from the end of the traveling straight route along the arc on the work unfinished side of the first circle (76A) to the first contact point (S1) between the first circle (76A) and the second circle (76B), a second re-setting turning route (77B) from the first contact point (S1) along the outer arc of the second circle (76B) to the second contact point (S2) between the second circle (76B) and the third circle (76C), and a third re-setting turning route (77C) from the second contact point (S2) along the arc on the work completion side of the third circle (76C) to the start of the set straight route (72B) are set. The radius (R1) is set larger than the turning radius (R) of the set turning route (72C). Continuously for a predetermined number of times Therefore, the work vehicle can be preferably automatically traveled from the end of the traveling turning route to the start of the set straight route (72B) adjacent to the traveling straight route via the first contact point (S1) and the second contact point (S2) without reverse travel or sharp turning, and the work efficiency such as compost spraying can be improved. , set the interval (W) between the set straight path (72B) and the adjacent set straight path (72B) to a length obtained by subtracting a preset overlap width (W2) from the working width (W1) of the working machine connected to the PTO shaft (6) of the work vehicle, set the predetermined radius (R1) to a length obtained by adding the overlap width (W2) to the turning radius (R), and when the number is less than the predetermined number of times, a first reset straight path (75A) from the first point (P1) which is the end of the traveling turning path to the second point (P2) on the set straight path (72B), and a second reset straight path (75B) from the second point (P2) to the start of the set straight path (72B) are set

[0011] Work ​The work vehicle can be more suitably automatically driven, and the working efficiency such as compost spreading can be further enhanced. Also, the work vehicle can be quickly returned from the first point (P1) which is the end of the traveling turning path to the second point (P2) on the set straight path (72B).

[0012] Claim 2 According to the invention described in claim 1 In addition to the effects of the invention described in claim

[0013] Claim 3 According to the invention described in claim 1 or 2 In addition to the effects of the invention described in claim

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0015] As shown in FIGS. 1 to 3, a work vehicle such as a tractor is provided with a pair of left and right front wheels 2 at the front lower side of the body frame 1, and a pair of left and right rear wheels 3 at the rear lower side of the body frame 1.

[0016] A bonnet 4 for mounting an engine E is provided at the front upper side of the body frame 1, a cockpit 5 for an operator to board is provided at the rear side of the bonnet 4, and a PTO shaft 6 extending in the front-rear direction for transmitting the output rotation of the engine E is provided at the lower rear side of the cockpit 5. A work implement 7 such as a manual spreader for spreading compost in the field is connected to the rear part of the PTO shaft 6.

[0017] The cockpit 5 is provided with a steering wheel 12 at the front side of the driver's seat 11, a touch panel 13 for displaying the output rotation speed of the engine E is provided at the front side of the steering wheel 12, and a clutch pedal 15 is provided at the lower part of a steering column 14 that houses a steering shaft.

[0018] As shown in FIG. 4, a positioning unit 20 using the RTK-GPS positioning method is composed of a positioning satellite 21, a base station 22 provided at a known position, and a mobile station 26 provided on the work vehicle. Thereby, the position of the mobile station 26, that is, the position of the work vehicle, can be accurately obtained from the position information transmitted from the positioning satellite 21 to the mobile station 26 and the correction position information transmitted from the base station 22 to the mobile station 26.

[0019] The base station 22 is composed of a fixed communication device 23, a fixed GPS antenna 24 that receives position information from the positioning satellite 21, and a fixed data transmission antenna 25 that transmits correction position information to the mobile station 26.

[0020] The mobile station 26 is composed of a mobile communication device 27, a mobile GPS antenna 28 that receives position information from the positioning satellite 21, and a mobile data transmission antenna 29 that receives correction position information from the base station 22. The mobile GPS antenna 28 and the mobile data transmission antenna 29 are provided at the front part of the upper wall of the cabin 16 of the operation unit 5.

[0021] As shown in FIG. 5, the output rotation of the engine E is transmitted to the speed increasing gear 31 via the clutch 30. The output rotation whose speed is increased or decreased by the speed increasing gear 31 is transmitted to the hydraulic continuously variable transmission 32. The output rotation whose speed is increased or decreased and the output rotation direction is switched by the hydraulic continuously variable transmission 32 is output from the first output shaft 32A and the second output shaft 32B.

[0022] The output rotation of the first output shaft 32A is increased or decreased by the gearbox 33. The output rotation of the gearbox 33 is transmitted to the output shaft 35 via the gear 34. The output rotation of the output shaft 35 is transmitted to a pair of left and right rear wheels 3 via the rear-wheel differential gear 36.

[0023] The output rotation of the second output shaft 32B is transmitted to the PTO relay shaft 39 via the PTO clutch 38. The output rotation of the PTO relay shaft 39 is transmitted to the PTO shaft 41 via the gear 40. Also, the output rotation of the PTO 41 is increased or decreased by the PTO transmission 42.

[0024] The output rotation of the output shaft 35 is transmitted to the front-wheel rear-side relay shaft 45 via the gear 44. The output rotation of the front-wheel rear-side relay shaft 45 is transmitted to the front-wheel front-side relay shaft 47 via the drive switching device 46. The output rotation of the front-wheel front-side relay shaft 47 is transmitted to a pair of left and right front wheels 2 via the front-wheel differential gear 48.

[0025] The drive switching device 46 is a device that switches between four-wheel drive and two-wheel drive, and also switches the drive mode to rotate the front wheels 2 at a higher speed than the rear wheels 3 during four-wheel drive.

[0026] When the front clutch 46A of the drive switching device 46 is connected and the connection of the rear clutch 46B is released, the output rotation of the output shaft 35 is transmitted to the front wheels 2 and the rear wheels 3, resulting in four-wheel drive. Also, the output rotation transmitted to the drive switching device 46 is not speeded up, and the front wheels 2 and the rear wheels 3 rotate at the same speed.

[0027] When the connection of the front clutch 46A of the drive switching device 46 is released and the rear clutch 46B is connected, the output rotation of the output shaft 35 is transmitted to the front wheels 2 and the rear wheels 3, resulting in four-wheel drive. Also, the output rotation transmitted to the drive switching device 46 is speeded up, and the front wheels 2 rotate at a higher speed than the rear wheels 3.

[0028] When the connection of the front clutch 46A of the drive switching device 46 is released and the connection of the rear clutch 46B is released, the output rotation of the output shaft 35 is transmitted only to the rear wheels 3, resulting in two-wheel drive.

[0029] As shown in FIG. 6, the controller 50 is formed by a processing unit 51 composed of a CPU or the like, a storage unit 52 composed of a ROM, a RAM, a hard disk drive, a flash memory, etc., and a communication unit 53 for data communication with the outside.

[0030] The processing unit 51 performs settings such as setting the reference path 71 described later and setting the set path 72 based on the reference path 71.

[0031] The storage unit 52 stores the number of laps N, the interval W, the set reference path 71, and the set path 72 input from the touch panel 13 described later.

[0032] The communication unit 53 communicates information with the base station 22 via an external portable controller or the mobile communication device 27.

[0033] On the input side of the controller 50, a mobile GPS antenna 28 for receiving position information from the positioning satellite 21, a mobile data transmission antenna 29 for receiving correction position information from the base station 22, a touch panel 13 for inputting the number of laps N, the interval W, etc., a reference path switch 17 for setting the reference path 71, a set path switch 18 for setting the set path 72 based on the reference path 71, and a travel switch 19 for switching the work vehicle to automatic travel are connected via a predetermined input interface circuit.

[0034] On the output side of the controller 50, an automatic travel switch 60 for automatically traveling the work vehicle, a reset straight path switch 61 for resetting the set straight path 71B, a reset turning path switch 62 for resetting the set turning path 71C, and an alarm switch 63 for sounding an alarm are connected via a predetermined output interface circuit.

[0035] <Set Path> As shown in FIG. 7, the operator moves the work vehicle into the field 70 from the loading entrance 70A of the field 70. The operator turns on the reference path switch 17 provided in the control unit 5 and makes the work vehicle travel in a counterclockwise direction along the inside of the ridges of the field 70. The controller 50 sets the reference path 71 along which the operator makes the work vehicle travel based on the input information from the mobile GPS antenna 28 and the mobile data transmission antenna 29 and records it in the storage unit 52. Note that the circular travel can also be clockwise.

[0036] After the operator makes the work vehicle travel in a circle, the operator turns on the set path switch 18 provided in the control unit 5. The controller 50 sets the set path 72 for automatically traveling the work vehicle based on the reference path 71 and records it in the storage unit 52.

[0037] The set path 72 is formed by a set circumferential path 72A that circulates counterclockwise along the inside of the reference path 71, a set linear path 72B that travels straight downward from the end of the set circumferential path 72A, and a semicircular set turning path 72C that connects the end of the set linear path 72B and the start of the set linear path 72B adjacent to the end with a predetermined radius. Thereby, the set path 72 for automatically driving the work vehicle according to each field 70 can be set efficiently. Note that the number of turns N of the set circumferential path 72A is input by the operator from the touch panel 13. Also, the circumferential travel can be clockwise.

[0038] The work vehicle that has completed the automatic travel and has automatically traveled to the end of the set path 72 is operated by the operator and carried out of the field 70 from the loading entrance 70A. Also, in FIG. 7, the reference path 71 and the like along which the operator drives the work vehicle are shown by solid lines, and the set path 72 is shown by a broken line.

[0039] <Set linear path> As shown in FIG. 8, the interval between the set linear paths 71B adjacent to each other is set to an interval W3 obtained by subtracting the overlap width W2 from the working width W1 of the working machine 7 connected to the PTO shaft 41 of the work vehicle. Thereby, it is possible to suppress the non-spread portion of the compost scattered from the working machine 7 over the entire area of the field 70. Note that the working width W1 and the overlap width W2 are input by the operator from the touch panel 13.

[0040] In this embodiment, the interval between the set circumferential paths 71A adjacent to each other is also set to the interval W, and the intervals between the innermost set circumferential path 71A and the start and end of the set linear path 71B are also set to the interval W. Also, the deviation determination line 73 described later is set at a portion extending in the left-right direction facing the set turning path 72C in the innermost set circumferential path 71A.

[0041] As shown in FIG. 9, the fourth and fifth driving turning paths of the automatically driving work vehicle deviate significantly continuously from the set turning path 72C. In this embodiment, when the radius R1 of the driving turning path becomes larger than the overlap width W2 or more of 1 / 2 (W1 - W2) of the radius (the "turning radius" in the claims) R of the set turning path 72C, that is, when the radius R1 is 1 / 2 (W1 + W2) or more, it is determined that the driving turning path has deviated from the set turning path 72C, and when the radius R1 is less than 1 / 2 (W1 + W2), it is determined that the driving turning path has not deviated from the set turning path 72C. In FIG. 9, the path traveled by the work vehicle during automatic driving is shown by a solid line, and the set path 82 is shown by a dashed line.

[0042] <Reset straight path> As shown in FIG. 10, when the controller 50 determines that the driving turning path has deviated from the set turning path 72C, it turns off the automatic driving switch 60 to stop the automatic driving of the work vehicle, then turns on the reset straight path switch 61 to set the first reset straight path 75A, etc. After setting the first reset straight path 75A, etc., it turns off the reset straight path switch 61 and turns on the automatic driving switch 60 to resume the automatic driving of the work vehicle. In FIG. 10, the path traveled by the work vehicle during automatic driving is shown by a solid line, and the set path 82 is shown by a chain line.

[0043] As shown in FIG. 10(a), the automatically driving work vehicle travels along a driving turning path with a radius R1 from the end portion of the set straight path 72B and automatically drives to the first point P1 where the virtual line L passing through the start portion of the set straight path 72B adjacent to the end portion of the set straight path 72B intersects the driving turning path.

[0044] As shown in FIG. 10(b), the controller 50 sets a first re-setting straight path 75A that forms an intersection angle θ with the set straight path 72B starting from the first point P1. The intersection angle θ is input by the operator from the touch panel 13 and is generally set to 15 to 30 degrees. Thereby, the controller 50 resumes the automatic travel of the work vehicle, causes the work vehicle to travel along the first re-setting straight path 75 from the first point P1, and can automatically travel the work vehicle to the second point P2 where the set straight path 72B and the first re-setting straight path 75A intersect.

[0045] As shown in FIG. 10(c), the controller 50 sets a second re-setting straight path 75B that connects the second point P2 and the starting end of the set straight path 72B. Thereby, the controller 50 resumes the automatic travel of the work vehicle and can automatically travel the work vehicle from the second point P2 to the end of the second re-setting straight path 75B, that is, the starting end of the set straight path 72B.

[0046] As shown in FIG. 10(d), the controller 50 turns off the re-setting straight path switch 61 and turns on the automatic travel switch 60. Thereby, the controller can cause the work vehicle to automatically travel again from the starting end of the set straight path 72B.

[0047] <Re-setting turning path> When the controller 50 determines that the traveling turning path has continuously deviated from the set turning path 72C and the number of consecutive deviations M has reached or exceeded a certain value, the controller turns off the automatic travel switch 60 to stop the automatic travel of the work vehicle, then turns on the re-setting turning path switch 62 to set the re-setting turning path 77. After setting the re-setting turning path 77, the controller turns off the re-setting turning path switch 62 and turns on the automatic travel switch 60 to resume the automatic travel of the work vehicle. The re-setting turning path 77 is formed by a first re-setting turning path 77A, a second re-setting turning path 77B, and a third re-setting turning path 77C, which will be described later. The number of consecutive deviations M is input by the operator from the touch panel 13. In FIG. 11, the path traveled by the work vehicle during automatic travel is shown as a solid line, and the set path 82 is shown as a dashed line.

[0048] Figure 11(a) shows a method for setting a reset turning path 77 of a work area where the virtual line L extends horizontally, that is, a work area where the sides facing the start and end portions of the set straight path in the work area for spreading compost are horizontal. Note that the left side of the path along which the work vehicle has traveled automatically in Figure 11(a) is the work completed side where compost spreading has ended, and the right side is the work uncompleted side where compost will be spread from now on.

[0049] The controller 50 sets a first circle 76A with a radius R1 that is tangent to the left side of the end portion of the path along which the work vehicle has traveled automatically, and a third circle 76C with a radius R1 that is tangent to the right side of the start portion of the set straight path 72B adjacent to the path along which the work vehicle has traveled automatically. Next, a second circle 76B with a radius R1 that has a center outside the virtual line L and is tangent to the first circle 76A and the third circle 76C is set. Note that the radius R1 is the radius R1 of the driving turning path that has deviated from the above-described set turning path 72C.

[0050] Figure 11(b) shows a method for setting a reset turning path 77 of a work area where the virtual line L slopes downward to the right, that is, a work area where the sides facing the start and end portions of the set straight path in the work area for spreading compost slope downward to the right. Note that the left side of the path along which the work vehicle has traveled automatically in Figure 11(b) is the work completed side where compost spreading has ended, and the right side is the work uncompleted side where compost will be spread from now on.

[0051] The controller 50 sets a first circle 76A with a radius R1 that is tangent to the left side of the end portion of the path along which the work vehicle has traveled automatically, and a third circle 76C with a radius R1 that is tangent to the right side of the start portion of the set straight path 72B adjacent to the path along which the work vehicle has traveled automatically. Next, a second circle 76B with a radius R1 that has a center outside the virtual line L and is tangent to the first circle 76A and the third circle 76C is set. In the present embodiment, the third circle 76C is set below and to the right of the first circle 76A.

[0052] FIG. 11(c) shows a method of setting the re-setting turning path 77 of the right-ascending working area, that is, the side facing the start or end of the set straight path in the working area where the compost is sprayed is right-ascending. Note that the left side of the path along which the work vehicle has traveled automatically in FIG. 11(c) is the work completion side where the spraying of the compost has ended, and the right side is the work unfinished side where the compost will be sprayed from now on.

[0053] The controller 50 sets a first circle 76A with a radius R1 that is in contact with the left side of the end of the path along which the work vehicle has traveled automatically, and a third circle 76C with a radius R1 that is in contact with the right side of the start of the set straight path 72B adjacent to the path along which the work vehicle has traveled automatically. Next, a second circle 76B with a radius R1 that has a center outside the virtual line L and is in contact with the first circle 76A and the third circle 76C is set. In the present embodiment, the third circle 76C is set above and to the right of the first circle 76A.

[0054] FIG. 12 explains the form in which the virtual line L in FIG. 11(a) extends horizontally. The same applies to the form in which the virtual line L in FIG. 11(b) is descending to the right and the form in which the virtual line L in FIG. 11(c) is ascending to the right.

[0055] As shown in FIG. 12(a), the controller 50 sets a first circle 76A with a radius R1 that is in contact with the end of the path along which the work vehicle has traveled automatically, a third circle 76C with a radius R1 that is in contact with the start of the set straight path 72B adjacent to the path along which the work vehicle has traveled automatically, and a second circle 76B with a radius R1 that is in contact with the first circle 76A and the third circle 76C.

[0056] As shown in FIG. 12(b), the controller 50 sets a first re-setting turning path 77A from the end of the path along which the work vehicle has traveled automatically to the contact point of the first circle 76A and the second circle 76B along the right arc of the first circle 76A. Thereby, the controller 50 can resume the automatic driving of the work vehicle and smoothly drive it automatically from the end of the path along which the work vehicle has traveled automatically to the first contact point S1, which is the contact point of the first circle 76A and the second circle 76B, along the right arc of the first circle 76A without reversing or making a sharp curve.

[0057] As shown in FIG. 12(c), the controller 50 sets a second reset turning path 77B from the first contact point S1 along the outer arc of the second circle 76B to the contact point between the second circle 76B and the third circle 76C. Thereby, the controller 50 resumes the automatic traveling of the work vehicle and can smoothly automatically travel the traveling vehicle from the first contact point S1 along the outer arc of the second circle 76B to the second contact point S2 which is the contact point between the second circle 76B and the third circle 76C without reverse traveling or sharp curves.

[0058] Further, the controller 50 determines whether or not the second reset turning path 77B extends outside the deviation determination line 73. When it is determined that the second reset turning path 77B extends outside the deviation determination line 73, the alarm switch 63 is turned on to sound an alarm, and the setting of the third reset turning path 77C is aborted. Thereby, it is possible to suppress the radius R1 of the second reset turning path 77B from becoming excessively large and prevent the work vehicle from colliding with the ridges in the field.

[0059] As shown in FIG. 12(d), the controller 50 sets a third reset turning path 77C from the second contact point S2 along the left arc of the third circle 76C to the start end of the set straight path 72B. Thereby, the controller 50 resumes the automatic traveling of the work vehicle and can smoothly automatically travel the traveling vehicle from the second contact point S2 along the left arc of the third circle 76C to the start end of the set straight path 72B without reverse traveling or sharp curves.

[0060] As shown in FIG. 12(e), the controller 50 turns off the reset straight path switch 61 and turns on the automatic traveling switch 60. Thereby, the controller can again automatically travel the work vehicle from the start end of the set straight path 72B.

[0061] <Method for setting the reset path> As shown in FIG. 13, in step S1, the processing unit 51 of the controller 50 determines whether the reference path switch 17 for setting the reference path is ON. If it is determined that the reference path switch 17 is ON, the process proceeds to step S2. If it is determined that the reference path switch 17 is not ON, step S1 is repeated.

[0062] In step S2, the processing unit 51 of the controller 50 determines whether the setting path switch 18 for setting the set path for automatically driving the work vehicle is ON. If it is determined that the setting path switch 18 is ON, the process proceeds to step S3. If it is determined that the setting path switch 18 is not ON, step S2 is repeated.

[0063] In step S3, the processing unit 51 of the controller 50 determines whether the travel switching switch 19 for automatically driving the work vehicle is ON. If it is determined that the travel switching switch 19 is ON, the process proceeds to step S4. If it is determined that the travel switching switch 19 is not ON, step S3 is repeated.

[0064] In step S4, the processing unit 51 of the controller 50 turns on the automatic travel switch 60 for automatically driving the work vehicle and proceeds to step S5.

[0065] In step S5, the processing unit 51 of the controller 50 compares the radius R1 of the travel turning path along which the work vehicle has automatically traveled with the radius R of the set turning path 72C stored in the storage unit 52, and determines whether the radius R1 is equal to or greater than the radius R by a predetermined range or more. If it is determined that the radius R1 is less than the radius R by a predetermined range, the process proceeds to step S6. If it is determined that the radius R1 is equal to or greater than the radius R by a predetermined range, the process proceeds to step S7. In the present embodiment, when the radius R1 is less than the overlap width W2 with respect to the radius R, the process proceeds to step S6. When it is determined that the radius R1 is equal to or greater than the overlap width W2 with respect to the radius R, the process proceeds to step S7.

[0066] In step S6, the processing unit 51 of the controller 50 substitutes 0 into the counter K stored in the storage unit 52 and returns to step S4.

[0067] In step S7, the processing unit 51 of the controller 50 adds 1 to the counter K stored in the storage unit 52 and proceeds to step S8.

[0068] In step S8, the processing unit 51 of the controller 50 determines whether the counter K stored in the storage unit 52 is less than the number of consecutive deviation times M. If it is determined that the counter K stored in the storage unit 52 is less than the number of consecutive deviation times M, the process proceeds to step S9. If it is determined that the counter K stored in the storage unit 52 is equal to or greater than the number of consecutive deviation times M, the process proceeds to step S10. In this embodiment, if it is determined that the counter K stored in the storage unit 52 is less than 2, the process proceeds to step S9. If it is determined that the counter K stored in the storage unit 52 is 2 or more, the process proceeds to step S10.

[0069] In step S9, the processing unit 51 of the controller 50 turns on the reset straight path switch 61, sets a first reset straight path 75A from the first point P1, which is the end portion of the traveling turning path, to the second point P2 on the set straight path 72B, and sets a first reset straight path 75A from the second point P2 to the start portion of the set straight path 72B, and then returns to step S4. Thereby, the work vehicle can be quickly returned from the end portion of the traveling turning path onto the set straight path 72B, and compost can be spread over the entire working area of the farm field.

[0070] In step S10, the processing unit 51 of the controller 50 turns on the reset turning path switch 62, and after setting the first circle 76A with a radius R1 that touches the end of the straight driving path, the third circle 76C with a radius R1 that touches the start of the set straight path 72B adjacent to the straight driving path, and the second circle 76B that touches the first circle 76A and the third circle 76C, it sets the first reset turning path 77A that goes from the end of the driving turning path along the right arc of the first circle 76 to the first contact point S1 which is the contact point of the first circle 76A and the second circle 76B, sets the second reset turning path 77B that goes from the outer arc of the second circle 76B to the second contact point S2 which is the contact point of the second circle 76B and the third circle 76C, and sets the third reset turning path 77C that goes from the second contact point S2 along the left arc of the third circle 76C to the start of the set straight path 72B adjacent to the straight driving path, and then proceeds to step S11. As a result, the work vehicle can be smoothly automatically driven from the end of the driving turning path to the start of the set straight path 72B adjacent to the straight driving path via the first contact point S1 and the second contact point S2 without reversing or making sharp curves.

[0071] In step S11, the processing unit 51 of the controller 50 determines whether or not the second reset turning path 77B extends outside the deviation determination line 73. If the second reset turning path 77B does not extend outside the deviation determination line 73, it returns to step S4. If the second reset turning path 77B extends outside the deviation determination line 73, it proceeds to step S12.

[0072] In step S12, the processing unit 51 of the controller 50 turns off the automatic driving switch 60 and returns to step S1. As a result, it is possible to suppress the radius R1 of the second reset turning path 77B from becoming excessively large and prevent the work vehicle from colliding with the ridges of the field.

Explanation of Signs

[0073] 6 PTO shaft 20 Positioning unit 21 Positioning satellite 22 Base station 26 Mobile station 50 Controllers 72 Setting Routes 72A Setting Circular Routes 72B Setting Straight Routes 72C Setting Turning Routes 73 Deviation Judgment Line 76A First Circle 76B Second Circle 76C Third Circle 77A First Re - setting Turning Route 77B Second Re - setting Turning Route 77C Third Re - setting Turning Route R Radius (Turning Radius) R1 Radius S1 First Contact Point S2 Second Contact Point W Interval W1 Working Machine Width W2 Overlap Width

Claims

1. In a work vehicle including a controller (50) that automatically drives the work vehicle along a set path (72) set in a field, and a positioning unit (20) that measures the travel path of the work vehicle, The set path (72) is formed from a set circular path (72A) that causes the work vehicle to circle in a clockwise or counterclockwise direction, a set straight path (72B) that causes the work vehicle to travel straight, and a set turning path (72C) that causes the work vehicle to turn. When the travel turning path of the work vehicle measured by the positioning unit (20) deviates continuously a predetermined number of times by a predetermined distance or more from the set turning path (72C), a first circle (76A) having a predetermined radius (R1) that contacts the work end side of the end portion of the travel straight path, a third circle (76C) having a predetermined radius (R1) that contacts the work unfinished side of the start portion of the set straight path (72B) adjacent to the travel straight path, and a second circle (76B) having a predetermined radius (R1) that contacts the first circle (76A) and the third circle (76C) are formed. A first re-setting turning path (77A) that reaches a first contact point (S1) between the first circle (76A) and the second circle (76B) along the arc on the work unfinished side in the first circle (76A) from the end portion of the travel straight path, a second re-setting turning path (77B) that reaches a second contact point (S2) between the second circle (76B) and the third circle (76C) along the outer arc in the second circle (76B) from the first contact point (S1), and a third re-setting turning path (77C) that reaches the start portion of the set straight path (72B) along the arc on the work end side in the third circle (76C) from the second contact point (S2) are set. The radius (R1) is set to be larger than the turning radius (R) of the set turning path (72C). The interval (W) between the set straight path (72B) and the set straight path (72B) adjacent thereto is set to a length obtained by subtracting a preset overlap width (W2) from the working width (W1) of a working machine connected to the PTO shaft (6) of the work vehicle. The predetermined radius (R1) is set to a length obtained by adding the overlap width (W2) to the turning radius (R). When the number of times is less than the specified number of times, a first re-setting straight path (75A) from a first point (P1) which is the end portion of the traveling turning path to a second point (P2) on the set straight path (72B), and a second re-setting straight path (75B) from the second point (P2) to the start portion of the set straight path (72B) are set. The work vehicle is characterized by this.

2. A deviation determination line (73) is provided at a position facing the second re-setting turning path (77B) in the set turning path (72A). When the second re-setting turning path (77B) extends outside the deviation determination line (73), the automatic traveling of the work vehicle is stopped. The work vehicle according to Claim 1.

3. The positioning unit (20) is formed by a positioning satellite (21), a base station (22), and a mobile station (26) provided on the work vehicle. The work vehicle according to Claim 1 or 2.

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