Work vehicles

Abstract

To provide a work vehicle capable of improving accuracy of control of a fertilizer application rate by using a fertilizer application map.SOLUTION: A work vehicle 1 comprises: a fertilizer application device 26; and a positioning device 130 for acquiring an own machine position. The work vehicle 1 is configured so that, on the basis of the own machine position acquired by the positioning device 130, using a fertilizer application map Dh for which a fertilizer application amount is set for a specific point, a fertilizer application amount of the fertilizer application device 26 is controlled. The work vehicle 1 travels on an outer periphery of a field H while acquiring position information, thereby generating a teaching field map Dq including a shape of the field and the position information, then uses the teaching field map Dq to correct the position information of the specific point recorded in the fertilizer application map Dh.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work vehicle for planting seedlings in a field. [Background technology]

[0002] Conventionally, work vehicles are known that acquire their own location information using a positioning device, and then, based on the acquired location information, control the amount of fertilizer to be applied by referring to a fertilizer application map in which the set amount of fertilizer to be applied for each point in the field is recorded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-101667 [Patent Document 2] Japanese Patent Application Publication No. 2019-187377 [Patent Document 3] Japanese Patent Application Publication No. 2019-41729 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with conventional work vehicles, there was a risk of an error occurring between the vehicle's own position obtained by a positioning device and the point at which the set fertilizer amount was obtained from the fertilizer map, which could reduce the accuracy of fertilizer amount control.

[0005] Therefore, an object of the present invention is to provide a work vehicle that can solve such problems and improve the accuracy of controlling the amount of fertilizer applied by using a fertilization map. [Means for solving the problem]

[0006] In order to achieve the above object, the first invention is: A work vehicle is provided with a fertilizer applicator and a positioning device that acquires its own position, and is configured to control the amount of fertilizer applied by the fertilizer applicator using a fertilization map in which the amount of fertilizer applied is set for each specific point based on the own position acquired by the positioning device, the work vehicle travels around the periphery of the field while acquiring position information, thereby creating a teaching field map including the shape and position information of the field; A work vehicle is provided that is configured to correct the position information of the specific point recorded in the fertilization map using the teaching field map.

[0007] According to the first aspect of the present invention, the accuracy of controlling the amount of fertilizer application using the fertilization map can be improved. In addition, the operator does not need to manually correct the position of the machine.

[0008] The second invention has the same configuration as the first invention, but also: The work vehicle is configured to create the teaching field map so as to include information on the field outline created from position information acquired by traveling around the periphery of the field, and to create a fertilization plan map including position information on the field outline created from the fertilization map by a predetermined operation of the operator, and to control the amount of fertilization by the fertilizer application device based on the set amount of fertilization set in the fertilization plan map; and further, The system is characterized in that it is configured to compare the position information of the field outline on the fertilization planning map with the position information of the field outline on the teaching field map, and correct the position information of the specific point.

[0009] According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, it is possible to correct the position information with higher accuracy.

[0010] The third invention, in addition to the configuration of the second invention, The method is characterized in that by comparing the position information of at least one corner of the field outline, the position information of the specific point is corrected so that the difference in position between the corners is minimized.

[0011] According to the third aspect of the invention, in addition to the effect of the second aspect of the invention, it is possible to correct the position information with higher accuracy.

[0012] The fourth invention is, in addition to the configuration of the second or third invention, When the set fertilizer amount obtained from the fertilizer planning map based on the location information exceeds the specified upper and lower fertilizer limit values, the set fertilizer amount is corrected so that it falls within the upper and lower fertilizer limit values.

[0013] According to the fourth invention, in addition to the effects of the second or third invention, the amount of fertilizer applied can be stabilized and the quality of the crop can be improved.

[0014] The fifth invention is, in addition to the configuration of the second or third invention, When the set fertilizer amount obtained from the fertilizer planning map based on the location information exceeds the specified upper and lower fertilizer limit values, the system switches to a real-time variable fertilizer mode that controls the fertilizer amount based on information about fertility obtained from the fertility sensor.

[0015] According to the fifth invention, in addition to the effects of the second or third invention, the amount of fertilizer applied can be stabilized and the quality of the crop can be improved. [Effects of the Invention]

[0016] According to the present invention, a work vehicle can be provided that can improve the accuracy of controlling the amount of fertilizer applied by using a fertilization map. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a left side view of a work vehicle 1 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a control block diagram relating to a control system of the work vehicle 1 of FIG. [Figure 3] 3 is a perspective view of a main part of the main speed change lever shown in FIG. 1. FIG. [Figure 4]FIG. 4 is a schematic plan view of a remote controller that remotely controls the work vehicle of FIG. [Figure 5] FIG. 5 is an explanatory diagram illustrating the flow of a work process of the work vehicle 1 of FIG. [Figure 6] FIG. 6 is an explanatory diagram illustrating the teaching process of the above. [Figure 7] FIG. 7 is a diagram showing a round trip in the automatic driving mode of the above-mentioned vehicle. [Figure 8] FIG. 8 is an explanatory diagram illustrating the automatic adjustment of the planting width during the reciprocating stroke of the above-mentioned method. [Figure 9] FIG. 9 is an explanatory diagram illustrating an inner periphery process in the automatic travel mode of the above embodiment. [Figure 10] FIG. 10 is a flowchart showing the processing of the control unit in the fertilization mode using the fertilization map. [Figure 11] FIG. 11 is an explanatory diagram for explaining a method for creating a fertilization plan map. [Figure 12] FIG. 12 is an explanatory diagram for explaining a method for creating a corrected fertilization plan map. [Figure 13] 13(a) and 13(b) are explanatory diagrams illustrating a method for correcting the field shape by the control unit. [Figure 14] FIG. 14 is an explanatory diagram illustrating an example of a method for determining the amount of movement in FIG. [Figure 15] FIG. 15 is an explanatory diagram of the same. [Figure 16] FIG. 16 is a flowchart showing the flow of control in the second planting mode according to the modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the basic configuration of the work vehicle will be described below.

[0019] <Basic configuration of work vehicle> FIG. 1 is a left side view of a work vehicle 1 according to a preferred embodiment of the present invention, and FIG. 2 is a control block diagram relating to a control system of the work vehicle 1 of FIG.

[0020] 3 is a perspective view of the main part of the main speed change lever shown in FIG. 1, and FIG. 4 is a schematic plan view of a remote controller that remotely controls the work vehicle 1. As shown in FIG. In this specification, as shown by the arrow in Figure 1, the side in the direction of travel of the work vehicle 1 is referred to as the front, and unless otherwise specified, the left side in the direction of travel of the work vehicle 1 is referred to as the "left" and the opposite side is referred to as the "right."

[0021] The work vehicle 1 in this embodiment is configured as a so-called rice transplanter, and as shown in Figure 1, is equipped with a traveling body 2 (hereinafter simply referred to as the "body"), a seedling planting unit 63 attached to the rear of the traveling body 2, a status indicator light 55 that displays the status of the work vehicle 1, a fertilizer applicator 26 that supplies fertilizer to the field, a pair of left and right line-drawing markers 40 that form lines on the field that serve as a guide for the traveling position when traveling while planting seedlings, a receiving antenna 130 attached to the front of the traveling body 2, an orientation sensor 80 that detects the direction in which the traveling body 2 is facing, an auxiliary seedling frame 74 attached to the front of the traveling body 2 and that stores seedlings to be supplied to the seedling planting unit 63, and a remote controller 44 (see Figures 2 and 4) that remotely operates the work vehicle 1 from outside.

[0022] The receiving antenna 130 and the direction sensor 80 are covered by the antenna cover 50 shown in FIG.

[0023] The receiving antenna 130 is an antenna that receives radio waves from GNSS satellites, and is capable of acquiring vehicle position information. The acquired position information is transmitted to the navigation ECU 70 of the control unit 87 provided in the traveling vehicle body 2 (see FIG. 2). RTK-GNSS is used to acquire the position information, and highly accurate position information can be acquired by receiving correction information.

[0024] In this embodiment, the SPP (Serial Port Profile) of Bluetooth (registered trademark) is used as an input interface for correction information, and a mobile phone or a Bluetooth (registered trademark) converter is connected and input using its device name.

[0025] The remote controller 44 is used by the worker to remotely operate the work vehicle 1, and upon receiving predetermined operations, transmits instructions such as instructions to start work, go forward / backward, and stop to a remote control antenna 52 provided on the vehicle. The remote controller 44 is also equipped with a display unit 44a that can display various information, and the display unit 44a is configured as a touch panel display that can receive operations from the worker and acquire various information. If the remote controller 44 and the work vehicle 1 become separated by more than the communication distance, the work vehicle 1 will recognize this and automatically stop for safety reasons.

[0026] As shown in Figure 1, the running body 2 is equipped with a control unit 87 covered by a front cover 47, a main frame 3 arranged approximately in the center of the running body 2, a rear frame 6 attached to the rear end of the main frame 3 and extending in the width direction of the work vehicle 1, a floor step 60 arranged above the main frame 3, a driver's seat 48 provided above the floor step 60, a control unit 49, an engine 7 provided below the driver's seat 48, a pair of left and right front wheels 8 (steered wheels) and a pair of left and right rear wheels 9 as running wheels, and a transmission mechanism such as a transmission case 30 that transmits the power of the engine 7 to the pair of left and right front wheels 8 and rear wheels 9.

[0027] The control unit 49 includes a main speed change lever 35 for changing the forward / reverse movement and vehicle speed of the traveling vehicle body 2, a steering mechanism 43 including a steering wheel 56 for steering the pair of left and right front wheels 8, a straight-line assist lever 79 provided near the left side of the steering wheel 56, a monitor 61 having operation switches, and an operation unit 54 provided with various operation switches for operating the work vehicle 1.

[0028] The straight driving assist lever 79 is swung when starting or stopping straight driving control, which is one of the automatic driving modes.

[0029] The steering mechanism 43 includes the steering wheel 56, as well as a steering shaft 83, a pitman arm, and a tie rod (not shown).

[0030] On the other hand, the driving force output from the engine 7 is transmitted to the transmission case 30 via a belt-type power transmission mechanism 4 and a hydrostatic continuously variable transmission (HST) 25 provided below the floor step 60, as shown in FIG.

[0031] The hydrostatic continuously variable transmission 25 is equipped with a trunnion shaft (not shown), and is configured so that when the main shift lever 35 is operated, the opening of the trunnion shaft is adjusted by the drive of the HST servo motor 150 (see Figure 2), changing the output to the transmission case 30 and adjusting the vehicle speed; when traveling forward, that is, when the main shift lever 35 is positioned in the forward range shown in Figure 3(b), the further forward the main shift lever 35 is operated to a position, the higher the vehicle speed is adjusted to be.

[0032] The power transmitted to the transmission case 30 is changed speed inside it and transmitted separately as power for running to the pair of left and right front wheels 8 and the pair of left and right rear wheels 9, and power (driving power) for driving the seedling planting section 63.

[0033] The power for driving is transmitted to a pair of left and right front wheels 8 via a front wheel final case 13 and a front wheel axle 31 (see Figure 1), and is also transmitted to a pair of left and right rear wheels 9 via a pair of left and right rear wheel transmission shafts 14, a pair of left and right rear wheel gear cases 51, and an axle 82 shown in Figure 1.

[0034] On the other hand, the driving power is transmitted to a planting clutch (not shown) provided at the rear of the traveling body 2, and is further transmitted to the seedling planting section 63 when the planting clutch is engaged.

[0035] As shown in Figure 1, the seedling planting unit 63 is attached to the traveling vehicle body 2 via a lifting link device 5. The lifting link device 5 includes an upper link arm 85 and a pair of left and right lower link arms 86, and is configured to be able to raise and lower the seedling planting unit 63.

[0036] The front ends of the upper link arm 85 and the lower link arm 86 are attached to a link base frame 10 fixed to the rear frame 6, and the other ends are attached to upper and lower link arms 11 located at the bottom of the seedling planting section 63.

[0037] When the electronic hydraulic valve 88 (see Figure 2) is controlled by the control unit 87 and the lifting hydraulic cylinder 12 shown in Figure 1 is hydraulically contracted, the upper link arm 85 is rotated upward and rearward, and the seedling planting unit 63 is raised to the non-working position. When the seedling planting unit 63 is in the non-working position, its lower end is positioned at approximately the same height as the bottom of the main frame 3.

[0038] In contrast, when the lifting hydraulic cylinder 12 is extended by hydraulic pressure, the upper link arm 85 is rotated backward and downward, and the seedling planting section 63 is lowered to a working position (the position shown in Figure 1) where seedling planting work can be performed.

[0039] As shown in Figures 1 and 2, the seedling planting section 63 comprises a platform 65 on which mat-shaped seedlings with soil (hereinafter referred to as "seedling mat") are placed, a plurality of planting devices 64 provided behind and below the platform 65, a center float 38 provided at the bottom of the seedling planting section 63, and side floats 39 arranged on the left and right sides of the center float 38.

[0040] The multiple planting devices 64 are arranged in the width direction of the work vehicle 1, and each planting device 64 is equipped with two pairs of planting tools 69, one on each side, aligned in the front-to-back direction. When the planting clutch is engaged and the drive shaft 67 shown in Figure 1 is rotated, the front planting tool 69 and the rear planting tool 69 shown in Figure 1 rotate around the drive shaft 67, alternately picking up seedlings located at the bottom end of the platform 65 and planting them in the field.

[0041] The center float 38 and the side floats 39 are each configured to glide over the field and level the ground as the work vehicle 1 travels, and seedlings are planted by each planting device 64 in the field leveled by each float 38, 39. The center float 38 and the side floats 39 each swing in accordance with the unevenness of the field.

[0042] Each of the pair of left and right line drawing markers 40 shown in Figure 1 comprises a line drawing body 41 that rolls on the field to form a line when the traveling vehicle body 2 is traveling, and a marker rod 42 that is L-shaped when viewed from the front and connects the line drawing body 41 and the traveling vehicle body 2, and is configured to be switchable between an active position in which the line drawing body 41 contacts the field and a non-active position in which the line drawing body 41 does not contact the field.

[0043] When the work vehicle 1 drives straight on the field to plant seedlings, the line drawing marker 40 of the pair of left and right line drawing markers 40 that is for the next row to plant seedlings (after turning) is driven straight while in the active position, thereby forming a line on the field that serves as a guide for the driving position when driving straight after turning. Note that Figure 1 shows the left line drawing marker 40 in the active position and the right line drawing marker 40 in the non-active position.

[0044] As shown in Figures 1 and 2, a center mascot 18 is provided at the front and center of the width of the work vehicle 1.When the work vehicle 1 turns on the field and drives straight on the next row, the driver can plant seedlings in the appropriate position by driving straight while operating the steering wheel 56 so that the center mascot 18 passes over the line formed by the line-drawing marker 40.

[0045] The auxiliary seedling frame 74 is attached to the front of the traveling body 2 via a frame 77 that supports the auxiliary seedling frame 74, as shown in Figure 1, in order to accommodate seedling mats to be replenished on the platform 65.

[0046] <Control system configuration> As shown in FIG. 2, the control unit 87 includes a navigation ECU 70 and a steering ECU 71.

[0047] The navigation ECU 70 calculates the route for automatic driving (automatic driving) during work based on position information from GNSS satellites and field shape information, and transmits appropriate steering information to the steering ECU 71 according to the route.

[0048] In addition, when the remote control antenna 52 receives an operation signal from the remote controller 44, the operation signal is transmitted to the navigation ECU 70, and the navigation ECU 70 drives the HST servo motor 150 to change the vehicle speed or control the hydraulic equipment based on the operation information obtained from the remote controller 44.

[0049] During autonomous driving, the steering ECU 71 controls the steering motor 57 based on information output from the navigation ECU 70. During manual driving mode, a steer-by-wire system is adopted, in which the steering motor 57 is driven based on the steering angle of the steering wheel 56.

[0050] As shown in FIG. 2, the input system of the work vehicle 1 includes a main speed change lever sensor 36 that detects the operating position of the main speed change lever 35 (see FIGS. 1 and 3), which changes the forward / reverse movement and vehicle speed of the work vehicle 1; a straight-line assist lever sensor 81 that detects the operation of the straight-line assist lever 79, which is operated to swing up or down when acquiring position information of the traveling body 2 or when starting or stopping straight-line control; a finger lever sensor 16 that detects the swing operation of the finger lever 23 that raises and lowers the seedling planting unit 63; a planting on / off switch 19 that switches the seedling planting operation on and off; a monitor 61 shown in FIG. 8; a marker switch 28 that switches the position of each of the left and right line-drawing markers 40; and a swing control switch 17 that sets the swing control. The marker switch 28 and the swing control switch 17 are provided in the operating unit 54. The finger lever 23 and the planting on / off switch 19 are provided in the main speed change lever 35 shown in FIG. 3.

[0051] In this embodiment, the straight-travel assist lever 79 can be swung upward and downward, and is configured so that after being swung in either the up or down direction, it automatically returns to its original up or down position by a spring.

[0052] As shown in Figure 2, the drive system of the work vehicle 1 includes a throttle motor 97 that adjusts the intake volume of the engine 7 located below the driver's seat 48, an electronic hydraulic valve 88 that extends and retracts the lifting hydraulic cylinder 12 when the seedling planting section 35 is raised and lowered, an HST servo motor 150 that adjusts the opening of the trunnion shaft in the hydrostatic continuously variable transmission 25 to change the forward / reverse movement and vehicle speed of the work vehicle 1, a steering motor 57 that rotates the steering shaft 83 and steering wheel 56, an electromagnetic valve 103 that engages and disengages the side clutch of the rear wheels 9, power steering 108, a planting clutch motor 27 that activates the planting clutch, a marker motor 34 that oscillates each of the pair of left and right line drawing markers 40, and a fertilizer amount adjustment motor 66 that adjusts the amount of fertilizer applied to the field by the fertilizer applicator 26.

[0053] The steering motor 57 is controlled by the control unit 87 for the purposes of straight-line control, turning control, and automatically rotating the steering wheel 56 in the unmanned automatic driving mode.

[0054] In addition, the control unit 87 is configured to be able to calculate the current height (vertical position) of the seedling planting unit 35 based on the output signal from the link sensor 89.

[0055] In addition, when the work vehicle 1 is traveling over the field while planting seedlings, the control unit 87 controls the electronic hydraulic valve 88 based on the detection signal from the float sensor 33 to extend and retract the lifting hydraulic cylinder 12 shown in Figure 1 and raise and lower the seedling planting unit 63 shown in Figure 1, thereby maintaining a constant planting depth of the seedlings in the field.

[0056] <Work process> FIG. 5 is an explanatory diagram illustrating the flow of a work process of the work vehicle 1. The work process of the work vehicle 1 according to this embodiment consists of four processes: a teaching process, a round-trip process, an inner circumference process, and a finishing process. In the first teaching process, a worker rides on three sides of the periphery of the field H (excluding the one side where seedlings are supplied) in teaching mode to plant rice. Position information is acquired via the receiving antenna 130 while the rice planting work is being carried out. This information is then used by the control unit 87 to create a teaching information map Dq, which is information indicating the shape of the field. Once this teaching information map Dq is created, a planned travel route is calculated based on the map, including information such as the preset work width, to indicate the position information of the trajectory of the travel path of the work vehicle 1 during the following round-trip process and the inner circumference process. This enables the work vehicle 1 to travel autonomously without a driver during the round-trip process and the inner circumference process, and the work vehicle 1 plants rice while automatically traveling along the calculated planned travel route. In the final finishing process, a worker rides on the remaining outer circumference side to plant rice, completing the rice planting work.

[0057] More specifically, the work proceeds according to the following steps. (1) Start The main switch of the work vehicle 1 is turned, the entire system is started up, and acquisition of position information using the receiving antenna 130 begins. (2) Azimuth angle recognition The worker turns the main switch of the work vehicle 1 to start, starts the engine 7, and drives the work vehicle 1 for about 2 m. This allows the work vehicle 1 to recognize the orientation of the vehicle body. This operation can be performed in either forward or reverse, and is completed in about 2 m. Therefore, the recognition is completed by simply entering the field as usual. (3) Entering the field and preparation for teaching The movement from entering the field to the teaching start position (work start position) is the same as that of a normal rice transplanter. In addition, the planting depth and the amount of seedlings removed can be adjusted in the same way as with a regular rice transplanter. Since the seedlings are actually planted during the teaching process, it is necessary to check the number of seedlings and the amount of fertilizer and herbicide used before starting work. (4) Teaching FIG. 6 is an explanatory diagram illustrating the teaching process. In addition, in teaching, the necessary processing is executed in the control unit 87 by switching from the manual operation mode to the teaching mode through a predetermined operation by the operator.

[0058] The teaching process involves manually moving along the ridges on the three outer edges of the field H (ln1, ln2, ln3) while planting seedlings. The work implement is manually raised and lowered to ensure that no seedlings are left unplanted. During this process, the receiving antenna 130 acquires positional information while traveling, and information on a teaching field map Dq (described later) is also created as appropriate and stored in the control unit 87.

[0059] When planting work on the three outer edges (ln1, ln2, ln3) is completed, the operator can switch to automatic operation mode by performing a predetermined operation. For example, by simultaneously pressing the circle F switch and the start + circle F switch on the remote controller 44, the control unit 87, which acquires this operation information, executes the necessary processing, thereby starting automatic travel on the round trip and inner circumference strokes.

[0060] (5) Round trip (automatic driving) FIG. 7 is a diagram showing a round trip in the automatic driving mode. After disembarking, the worker performs a predetermined operation using the remote controller 44 after the teaching process, and the control unit 87, which acquires this operation information, executes the necessary processing and starts automatic driving for the round trip process.

[0061] During the round trip, the work vehicle 1 is configured to automatically travel back and forth along the planned travel route, alternately traveling back and forth between a straight route and a turning route. When the work vehicle 1 reaches the end of the straight route (the edge of the field H), it automatically turns along the turning route and its travel is controlled so that it enters the next straight route. In order to ensure space for turning, the work vehicle 1 automatically moves backwards about 1 meter before turning. At this time, the seedling planting unit 63 is also automatically raised and lowered (raised when traveling on the turning route, and lowered when traveling on the straight route). In this way, by repeating the above procedure during the round trip, the work vehicle 1 automatically performs rice planting work while traveling back and forth within field H.

[0062] (6) Automatic planting width adjustment FIG. 8 is an explanatory diagram illustrating automatic adjustment of the planting width during the reciprocating stroke. Depending on the size of the field, row tacking or empty running may be performed on the penultimate round trip. The system is configured to automatically tacking rows and adjust planting width on the penultimate outbound or inbound trip.

[0063] If the strip-tack work is performed on the outbound trip, the return trip will skip one stroke and be performed as an empty run, after which the work for the final round trip will be performed.

[0064] (7) Inner Circumference (Automatic Travel) FIG. 9 is an explanatory diagram illustrating the inner periphery process in the automatic travel mode. When the work vehicle 1 is in automatic driving mode, after completing the round trip, it moves to the inner periphery process, where it plants while traveling on the inner periphery remaining between the teaching process and the round trip. At this time, seedlings and fertilizer are replenished and the headland rotor is set as necessary.

[0065] In this way, after the inner circumferential process is completed, seedlings are planted in the manual travel mode along the supply path and in the area where automatic planting was performed (the lower part of the drawing in Figure 9).

[0066] <Fertilization amount adjustment means> Next, the fertilizer application amount adjusting means of the work vehicle 1 will be described. The control device 87 of the work vehicle 1 is configured to be able to switch between two modes with different methods of determining and adjusting the amount of fertilizer: a fertilization mode based on a fertilization map and a real-time variable fertilization mode. In other words, the control device 87 is configured to control the fertilizer amount adjustment motor 66 with different control amounts in the fertilization mode based on a fertilization map and the real-time variable fertilization mode. The fertilization mode based on a fertilization map and the real-time variable fertilization mode can be switched between at any timing by the operator through a predetermined operation (for example, operating a button on the remote controller 44).

[0067] <Fertilization mode based on fertilization map> The fertilization mode according to the fertilization map Dh will be described with reference to FIGS. Fig. 10 is a flowchart showing the processing of the control unit 87 in the fertilization mode using the fertilization map Dh. Fig. 11 is an explanatory diagram for explaining a method for creating the fertilization plan map Dp, and is an explanatory diagram for explaining a method for creating a corrected fertilization plan map.

[0068] The fertilization mode using the fertilization map is a mode in which the amount of fertilization is determined and adjusted (controlled) using the fertilization map Dh, in which the amount of fertilization is set for each specific point (section). When the fertilization mode using the fertilization map Dh is selected by a predetermined operation, the control unit 87 acquires information about the fertilization map Dh (step S10).

[0069] As shown in FIG. 11, the fertilization map Df is configured with rectangular sections of a predetermined size arranged in a matrix. Each section corresponds to a specific area including the field and its surroundings. The fertilization map Df is digitized so that each section can be identified by two-dimensional coordinates. The position of any point Pm is identified by coordinates X and Y, and a set fertilizer amount value M is set for each coordinate. The fertilization map Df may be stored in advance in the control unit 87, or may be configured to be acquired from an external storage device via a network. The data on this fertilization map Df is color-coded according to the amount of the set fertilizer amount value M. In the case of FIG. 11, the data is color-coded into five levels: color 1 is 65, color 2 is 57, color 3 is 45, color 4 is 35, and color 5 is 32. The unit of amount is kg / 10a.

[0070] Next, the control unit 87 acquires information on the geographic map Dt (step S11). The geographical map Dt is map information about the area around the field, and the map information also includes location information corresponding to the map. The geographical map Dt may be stored in the control unit 87 in advance, or may be configured to be acquired from an external storage device via a network. After acquiring the geographical map Dt, the control unit 87 displays the map on the display unit 44a of the remote controller 44, accepts an operation from the operator, and acquires information about the outline Hg of the field H (field outline information) (step S12). That is, the operator can input the outline Hg of the field by tracing the displayed map with his / her finger. Note that the field outline Hg may be input not only via the remote controller 44, but also by displaying the map on the monitor 61 and accepting input via an operation on the monitor 61.

[0071] Next, the control unit 87 creates a fertilization plan map Dp based on the acquired fertilization map Df and the input information about the outline Hg of the field H. The fertilization plan map Dp is data created by cutting out the fertilization map Df along the outline Hg of the field H. More specifically, the control unit 87 calculates position information for the field outline Hg from the input outline Hg of the field H, and creates a fertilization plan map Dp in which the fertilization map Df contains the fertilization amount set values M for the sections that belong to positions within the field outline Hg, along with their position information. As a result, the fertilization plan map Dp includes at least the position information P1 (X1, X2), P2 (X2, Y2), P3 (X3, Y3), and P4 (X4, Y4) of the four corners of the field H to be worked on, and information about the fertilization amount set value M for each of the sections X and Y within the field outline Hp connecting these four corners. The position information P1 (X1, X2), P2 (X2, Y2), P3 (X3, Y3), and P4 (X4, Y4) of the four corners of the field H are calculated from the positions of the four corners of the input outline Hg of the field H.

[0072] Thereafter, the control unit 87 acquires the teaching field map Dq (step S13), and creates a corrected fertilization plan map Dpq from the fertilization plan map Dp and the teaching field map Dq (step S14). This corrected fertilization plan map Dpq is obtained by correcting the fertilization plan map Dp based on the information in the teaching field map Dq.

[0073] Here, the teaching field map Dq is data including the shape and position information of the field H, which is created during the teaching process by manually moving along the ridges around the three outer edges (ln1, ln2, ln3) of the field H while planting seedlings, while acquiring position information using the receiving antenna 130. As shown in Fig. 12, the teaching field map Dq is created by traveling along the first edge ln1 of the field H to obtain position information for the travel trajectory L (L1), then traveling along the second edge ln2 to obtain position information for the travel trajectory L (L2), and traveling along the third edge ln3 to obtain position information for the travel trajectory L (L3).

[0074] The position information Q1 (x1, y1) of the first corner Q1 of the field shape Hq can be, for example, the position information obtained by the receiving antenna 130 when the seedling planting section 63 is lowered after switching from manual operation mode to teaching mode.

[0075] The position information Q2 (x2, y2) of the second corner Q2 of the field shape Hq can be, for example, the position information obtained by the receiving antenna 130 when the work vehicle 1 travels along the first edge ln1 of the field H, raises the seedling planting section 63, and then lowers it again.

[0076] In a similar manner, the position information Q3 (x3, y3) of the third corner Q3 of the field shape Hq can be the position information obtained by the receiving antenna 130, for example, when the work vehicle 1 travels along the second edge ln2 of the field H, raises the seedling planting section 63, and then lowers it again.

[0077] Furthermore, the position information Q4 (x4, y4) of the fourth corner Q4 of the field shape Hq can be, for example, the position information obtained by the receiving antenna 130 when the work vehicle 1 runs along the third side ln3 of the field H and then raises the seedling planting section 63.

[0078] In this way, when the control unit 87 obtains the positional information of the first to fourth corners Q1 to Q4 of the field shape Hq, it connects these to calculate the field shape Hq, thereby obtaining a teaching field map Dq that includes the shape and positional information of the field H.

[0079] Next, a revised fertilization plan map Dpq is created by correcting the fertilization plan map Dp based on the teaching field map Dq. More specifically, as shown in Fig. 12, the position information X, Y in the fertilization plan map Dp is translated by ΔX, ΔY. As a result, for example, in the fertilization plan map Dp, the fertilization amount setting value M at point Pm becomes the fertilization amount setting value from position (X, Y) to position (X + ΔX, Y + ΔY) through translation.

[0080] Once the corrected fertilization plan map Dpq is created, the control unit 87 controls the fertilizer amount while traveling to work, while acquiring position information as appropriate, so that the fertilizer amount matches the fertilizer amount set value M of the corrected fertilization plan map Dpq (step S15). That is, the control unit 87 acquires position information, acquires the fertilizer amount set value M corresponding to that position on the corrected fertilization plan map Dpq from the position information, and controls the fertilizer amount adjustment motor 66 so that the acquired fertilizer amount set value M matches. In this way, by controlling fertilization based on the corrected fertilization plan map Dpq, which is modified based on the field position information acquired by the fertilizer itself, instead of the fertilization plan map Dp, it is possible to correct any deviation in the fertilizer's position on the fertilization plan map Dp, thereby improving the accuracy of the fertilizer amount. In addition, by translating the position information X and Y in the fertilization plan map Dp by ΔX and ΔY, it is possible to eliminate the need for the operator to manually correct the fertilizer's position on the fertilization plan map Dp to match the field position in the fertilization plan map Dp at the start of work. That is, in the past, when position information was acquired at the start of work, if there was a discrepancy between the machine's own position on the fertilization plan map Dp and the actual field position, the operator had to manually reset the machine's own position to eliminate the discrepancy, but the above configuration can eliminate this hassle. Note that, in the past, the cause of a certain discrepancy between the machine's own position on the fertilization plan map Dp and the actual field position was that the correspondence between the position information included in the fertilization plan map Dp and the position information acquired by the machine itself via the receiving antenna 130 did not necessarily match, and errors occurred due to various factors. The above configuration can effectively eliminate such errors.

[0081] 13(a) and 13(b) are explanatory diagrams illustrating a method for correcting the field shape Hq by the control unit 87. As shown in FIG. 13(a), in the process of step S13 in FIG. 10 above, the control unit 87 may be configured to merge two sides of the field shape Hq if the angle α between one side and another adjacent side is equal to or greater than a certain angle. This allows the field shape Hq to be created with high accuracy. Furthermore, as shown in FIG. 13(b), the control unit 87 may be configured to delete a specific side of the field shape Hq if the distance between the specific side is equal to or less than a certain value. This simplifies the field shape Hq and shortens the processing time.

[0082] <How to determine the amount of movement> Next, a method for determining the amount of movement D (ΔX, ΔY) indicated by the arrow in FIG. 12 when translating the position information X, Y in the fertilization plan map Dp by ΔX, ΔY in step S14 in FIG. 10 above will be described. The control unit 87 can determine the amount of movement D, for example, as follows. Using any of the following methods, it is possible to prevent an error from occurring between the machine's own position acquired by the receiving antenna 130 and the point where the set fertilizer amount is acquired from the fertilization map, thereby improving the accuracy of fertilizer amount control using the fertilization map. In addition, it eliminates the need for the operator to manually correct the machine's own position.

[0083] (1) Example 1 of how to determine the movement amount D FIG. 14 is an explanatory diagram illustrating an example of a method for determining the movement amount D in FIG. As shown in Figure 14, the movement amount D (ΔX, ΔY) can be determined so that the field shape Hq is inside the field outline Hg. Here, after the teaching process, the own machine position A is inside the field shape Hq, and by having the field shape Hq enter the field outline Hg, the own machine position A can be reliably positioned inside the field outline Hg. This prevents a situation in which, for example, at the start of a round trip, the position information of the field outline Hg is deviated from the correct position due to factors such as an error in the calculation process, causing the own machine position A to be located outside the field outline Hg and making it impossible to obtain the correct fertilizer amount from the fertilization plan map Dp. This allows the control unit 87 to reliably obtain the fertilizer amount set value M and control the fertilizer amount based on the position information. In this case, as shown in FIG. 15, the reference field shape Hq may be determined based on the orientation of the vehicle body and the distance from the vehicle's own position A.

[0084] (2) Example 2 of how to determine the amount of movement D The movement amount D(ΔX, ΔY) may be determined so as to minimize the sum of the difference in position between P1 and Q1 (|X1-x1|, |Y1-y1|), the difference in position between P2 and Q2 (|X2-x2|, |Y2-y2|), the difference in position between P3 and Q3 (|X3-x3|, |Y3-y3|), and the difference in position between P4 and Q4 (|X4-x4|, |Y4-y4|). This allows the movement amount D(ΔX, ΔY) to be determined so that the position information of the field shape Hq and the field outline Hg are superimposed. As a result, the own machine position A can be positioned inside the field shape Hq, and the fertilizer amount setting value M can be obtained and the fertilizer amount can be controlled appropriately based on the position information.

[0085] (3) Example 3 of how to determine the movement amount D The movement amount D(ΔX, ΔY) may be determined so as to minimize any one of the following: the difference in position between P1 and Q1 (|X1-x1|, |Y1-y1|), the difference in position between P2 and Q2 (|X2-x2|, |Y2-y2|), the difference in position between P3 and Q3 (|X3-x3|, |Y3-y3|), and the difference in position between P4 and Q4 (|X4-x4|, |Y4-y4|). This allows, for example, during the teaching process, even at a stage where only the position information of Q1 has been acquired, to determine the movement amount D(ΔX, ΔY) so as to minimize the difference in position between P1 and Q1 (|X1-x1|, |Y1-y1|). Therefore, during the teaching process, the robot's own position A can be positioned inside the field shape Hq, and the fertilizer amount setting value M can be acquired and the fertilizer amount can be controlled appropriately based on the position information.

[0086] (4) Example 4 of how to determine the movement amount D The system may be configured to update the movement amount D (ΔX, ΔY) in real time during the teaching process, and accordingly, move the corrected fertilization plan map Dpq backward. For example, when the position information of Q1 is acquired, the corrected fertilization plan map Dpq is created with the movement amount D that minimizes the difference in position between P1 and Q1 (|X1-x1|, |Y1-y1|). Next, when the position information of Q2 is acquired, the movement amount D (ΔX, ΔY) is determined so that the sum of the difference in position between P1 and Q1 (|X1-x1|, |Y1-y1|) and the difference in position between P2 and Q2 (|X2-x2|, |Y2-y2|) is minimized, and the corrected fertilization plan map Dpq is updated. In a similar manner, when the position information of Q3 is acquired, and when the position information of Q3 is acquired, the corrected fertilization plan map Dpq is updated. As a result, even during the teaching process, the machine position A can be positioned appropriately inside the field shape Hq, and the fertilizer amount setting value M can be obtained appropriately based on the position information, allowing the amount of fertilizer to be controlled.

[0087] <Automatic adjustment of fertilizer amount> The control unit 87 is configured to automatically adjust the amount of fertilizer applied so that it falls within the upper and lower limits of fertilization, if the fertilization setting value obtained using the corrected fertilization plan map Dpq based on the obtained position information exceeds the upper and lower limits of fertilization that the fertilizer application device 26 can deliver (for example, an upper limit of 80 kg / 10 a and a lower limit of 10 kg / a). More specifically, the amount of fertilizer applied is corrected (the range is narrowed) so that it falls within the upper and lower limits of fertilization, reducing the deviation from a predetermined basic fertilizer amount. This makes it possible to control the amount of fertilizer applied appropriately while preventing malfunctions. At this time, the control unit 87 may be configured to issue a warning to the operator using a buzzer or the like.

[0088] <Real-time variable fertilization> Figure 16 is a flowchart showing the processing of the control unit 87 in the real-time variable fertilization mode. As shown in Figure 16, in the real-time variable fertilization mode 87, information about fertility is appropriately acquired from a fertility sensor that detects fertility (SFV: Soil Fertility Value) attached to the front wheel 8, along with position information (steps S21 to S22), and the amount of fertilization is controlled (increased or decreased) in real time based on the acquired fertility value (step S24). The setting of the amount of fertilization relative to the fertility value is stored in advance in the control unit 87.

[0089] <Automatic switching between fertilization mode based on fertilization map and real-time variable fertilization mode> The control unit 87 may be configured to automatically switch between a fertilization mode based on the fertilization map and real-time variable fertilization. For example, if the fertilization setting value acquired by using the correct fertilization plan map Dpq during the fertilization mode based on the fertilization map Dh exceeds the upper or lower limit of fertilization that can be delivered by the fertilizer applicator 26 (for example, upper limit 80 kg / 10 a, lower limit 10 kg / a), the control unit 87 may be configured to automatically switch to the real-time variable fertilization mode instead of automatically adjusting the fertilizer amount.

[0090] The embodiments of the present invention have been described above. The present invention is not limited to the above-described embodiments. It goes without saying that the present invention can be modified appropriately within the scope of the technical concept. [Explanation of symbols]

[0091] 1 Work vehicle 2 Running vehicle 3. Mainframe 4 Belt-type power transmission mechanism 5 Lifting link device 6 Rear frame 7 Engine 8 front wheels 9 rear wheels 10 Link base frame 11 Upper and lower link arms 12 Lifting hydraulic cylinder 13 Front wheel final case 14 Rear wheel drive shaft 15 Power transmission mechanism 16 Finger lever sensor 17 Swivel control switch 18 Center Mascot 19 Planting on / off switch 20 Sub-transmission mechanism 21 Front wheel rotation sensor 23 Finger Lever 24 Sub-gear lever 25 Hydrostatic continuously variable transmission 26 Fertilizer application equipment 27 Planting clutch motor 28 Marker Switch 29 Rear wheel rotation sensor 30 Mission Case 31 Front axle 32 Display 33 Float sensor 34 Marker Motor 35 Main gear shift lever 36 Main shift lever sensor 37 Tilt detection sensor 38 Center Float 39 Side Float 40 Line Marker 41 Linear 42 Marker Rod 43 Steering mechanism 44 Remote Controller 45 Steering sensor 46 frames 47 Front cover 48 cockpit 49 Control Unit 50 Antenna cover 51 Rear wheel gear case 52 Remote control antenna 54 Control section 55 Status indicator light 56 Steering wheel 57 Steering motor 60 Floor Steps 61 Monitor 62 Operation switch 63 Seedling planting department 64 Planting equipment 66 Fertilizer amount adjustment motor 67 Drive shaft 68 Plate 69 Planting tools 70 Navigation ECU 71 Steering ECU 74 Auxiliary seedling frame 79 Straight-line assist lever 80 Orientation sensor 81 Straight-line assist lever sensor 82 rear wheel axle 83 Steering shaft 85 upper link arm 86 Lower link arm 87 Control Unit 88 Electronic Hydraulic Valve 89 Link Sensor 96 Engine revolution sensor 97 Throttle motor 102 indicator 103 Solenoid valve 108 Power steering 110 Seat switch 111 Torque sensor 112 speakers 150 HST servo motor

Claims

1. A work vehicle is provided with a fertilizer applicator and a positioning device that acquires its own position, and is configured to control the amount of fertilizer applied by the fertilizer applicator by using a fertilization map in which a target amount of fertilizer is preset for each specific point, and by identifying points on the fertilization map based on the vehicle's own position acquired by the positioning device, the work vehicle travels around the periphery of the field while acquiring position information, thereby creating a teaching field map including the shape and position information of the field; A work vehicle characterized in that it is configured to use the created teaching field map to correct the position information of the specific point recorded in the fertilization map so that the outline of the field on the fertilization map overlaps with the outline of the field on the teaching field map.

2. The work vehicle is configured to create the teaching field map so as to include information on the field outline created from position information acquired by traveling around the periphery of the field, and to create a fertilization plan map including position information on the field outline created from the fertilization map by a predetermined operation of the operator, and to control the amount of fertilization by the fertilizer application device based on the set amount of fertilization set in the fertilization plan map; and further, The work vehicle according to claim 1, characterized in that it is configured to compare position information of the field outline of the fertilization planning map with position information of the field outline of the teaching field map, and correct the position information of the specific point.

3. The work vehicle according to claim 2, characterized in that the position information of the specific point is corrected by comparing the position information of at least one corner of the field outline so that the difference in position between the corners is minimized.

4. A work vehicle as described in claim 2 or claim 3, characterized in that when the set fertilizer amount obtained from the fertilizer planning map based on location information exceeds predetermined upper and lower fertilizer limit values, the set fertilizer amount is corrected so that it falls within the upper and lower fertilizer limit values.

5. A work vehicle as described in claim 2 or claim 3, characterized in that when the set fertilizer amount obtained from the fertilizer planning map based on location information exceeds predetermined fertilizer upper and lower limit values, the vehicle switches to a real-time variable fertilization mode in which the fertilizer amount is controlled based on information about fertility obtained from a fertility sensor.

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