Work vehicle

Abstract

To provide a work vehicle which can flexibly change a determination method of a fertilizer application amount per farm field among a plurality of farm fields to perform fertilization work.SOLUTION: A work vehicle comprises a fertilizing unit, and a positioning device for acquiring an own machine position, and is configured to acquire a target fertilizing amount set in a section to which the own machine position belongs, from a fertilization map based on the own machine position acquired by the positioning device and control a fertilizing amount of the fertilizing unit. The work vehicle further includes: a soil information acquisition part for acquiring soil information of a farm field; and a controller for controlling the fertilizing amount of the fertilizing unit. The soil information acquisition part includes a plowed soil depth sensor and a fertility degree sensor. The controller can select and execute: a fertilization map utilization fertilization mode for determining the fertilizing amount of the fertilizing unit based on information of the fertilization map; and a soil information utilization fertilization mode for determining the fertilizing amount of the fertilizing unit by using the soil information acquired by the soil information acquisition part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a work vehicle that applies fertilizer while traveling in a farm field. [Background technology]

[0002] In recent years, while the aging of agricultural workers and labor shortages have become issues, the area of ​​farmland managed per commercial farm in Japan has been on the rise, and this trend is expected to continue in the future. In response to this, interest in smart agriculture, which uses robotics and ICT to achieve ultra-labor-saving, high-quality production, is growing.

[0003] In the midst of this trend, in the technical field of work vehicles used for agricultural work, for example, as shown in Patent Document 1 below, efforts are being made to make work smarter by using positioning satellite systems such as GPS to operate work vehicles autonomously within fields.

[0004] Incidentally, leveling the growth of crops in the entire field has been a problem in the past in terms of preventing crops from lodging. However, the environment in which crops grow in a field is not uniform, and the ease with which crops grow usually varies depending on the location in the field, and the larger the area of ​​the field, the more likely it is that the degree of growth will vary. Therefore, in the field, the amount of fertilizer is increased in places where crops grow easily, and the amount of fertilizer is reduced in places where crops do not grow easily, thereby leveling the growth of crops in the entire field. For example, as described in the following Patent Document 2, in the technical field of work vehicles that can run by unmanned operation, a technology is known that automatically adjusts the amount of fertilizer applied by the work vehicle according to the position in the field using information on a fertilization plan map in which a target amount of fertilizer is set for each predetermined section of the field. This fertilization plan map is data that links the location information of each specified section of the field with the target amount of fertilizer to be applied, and a smaller amount of fertilizer is set in sections where crops are easy to grow, and a larger amount is set in sections where crops are difficult to grow.

[0005] Using this fertilization plan map information, a conventional work vehicle acquires its own position information at a specified time interval while traveling to identify the section of the field where it is working, and automatically controls the fertilizer device to apply the target amount of fertilizer associated with the identified section. This makes it possible for a conventional work vehicle to automatically adjust the amount of fertilizer applied for each section of the field while traveling automatically in the field. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-266608 [Patent Document 2] JP 2021-101667 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when fertilizing multiple fields with conventional work vehicles, a fertilization map must be prepared for each field, which increases the workload. In particular, when fertilizing a new field on an abandoned farmland, it can be difficult to prepare a fertilization map due to a lack of past data and practice.

[0008] In addition, when fertilizing multiple fields, in fields where the difference in plowed soil depth (i.e., the depth of the plowed soil layer) is larger than usual depending on the location, fertilization based on the fertilization map is not necessarily effective, and seedlings may grow too much in areas with deep plowed soil and fall over. Therefore, there is a need to be able to flexibly change the method of determining the amount of fertilizer to be applied for each field.

[0009] Therefore, the present invention aims to provide a work vehicle that solves such problems, reduces the workload of having to prepare a fertilization map for each field, and enables fertilization work by flexibly changing the method of determining the fertilizer amount for each field. [Means for solving the problem]

[0010] In order to achieve the above object, the first invention provides: A work vehicle comprising a fertilizer applicator and a positioning device that acquires its own position, and configured to acquire a target fertilizer amount set for a section to which the own position belongs by utilizing a fertilization map in which a fertilizer amount is set for each section of a field based on the own position acquired by the positioning device, and to control the fertilizer amount of the fertilizer applicator, The method further includes a soil information acquisition unit that acquires soil information of the field, and a control device that controls the amount of fertilizer applied by the fertilizer application device. The soil information acquisition unit includes a tilled soil depth sensor that measures the tilled soil depth of the soil and a fertility sensor that measures the fertility of the soil, The fertilization map utilizing fertilization mode is configured to be executable by selecting a fertilization amount of the fertilization device based on the information of the fertilization map, and a soil information utilizing fertilization mode is configured to determine a fertilization amount of the fertilization device using soil information acquired from the soil information acquisition unit, The control device provides a work vehicle characterized in that, when a fertilization mode using a fertilization map is being executed and the cultivated soil depth measured by a cultivated soil depth sensor becomes equal to or greater than a set depth, the control device automatically switches to a fertilization mode using soil information.

[0011] According to the first aspect of the present invention, a fertilization map-based fertilization mode and a soil information-based fertilization mode are selected. By configuring the system to be selectively executable, it is no longer necessary to prepare a fertilization map for each of multiple fields. This reduces the workload that must be spent on fertilizer application. This allows fertilization work to be performed by changing the fertilization mode. In addition, in areas where the cultivated soil depth is deep, the fertilization mode is automatically switched to fertilization using soil information. As a result, fertilization can be performed in areas where the cultivated soil depth is deep using a fertilizer amount determination method that takes the cultivated soil depth into account, which effectively prevents lodging caused by seedlings growing too deep due to the deep cultivated soil depth.

[0012] The second invention is the above-mentioned first invention, The fertilizer amount calculated by the soil information using fertilization mode is averaged for each field plot to create a soil information using fertilization map, and the system is configured to be able to display information about the fertilization map and information about the soil information using fertilization map on a display unit.

[0013] According to the second invention, in addition to the effects of the first invention, the fertilizer map information and the soil information-utilizing fertilization map information can be displayed on the display unit, which can be useful for analyzing fertilization of multiple fields.

[0014] The third invention is the second invention, The control device includes a soil information learning unit that learns the acquired soil information, The fertilization map utilizing fertilization mode is configured to be able to acquire the soil information from the soil information acquisition unit, and determines the amount of fertilization of the fertilization device based on information of the fertilization map, The soil information utilization fertilization mode is characterized in that the amount of fertilizer applied by the fertilizer application device is determined by comparing the soil information acquired from the soil information acquisition unit with the soil information learned by the soil information learning unit.

[0015] According to the third invention, in addition to the effect of the second invention, it becomes possible to carry out fertilization work by flexibly changing the method of determining the amount of fertilizer to be applied for each field.

[0016] The fourth invention is the first invention, A field group information management unit that manages information regarding managed fields, the group of fields information management unit includes a group of fields information creation unit that creates group of fields information, a group of fields analysis information creation unit that creates group of fields analysis information, and a group of fields information storage unit that stores information about managed fields; The control device is further configured to be able to execute a basic fertilizer amount fertilization mode in which a preset basic fertilizer amount is determined as the fertilizer amount of the fertilizer application device; A basic fertilizer amount setting unit that sets the basic fertilizer amount, The basic fertilizer amount setting unit is characterized in that, when an operator selects a standard field from among multiple fields included in the managed fields and sets a basic fertilizer amount, the basic fertilizer amount is automatically set for fields that were not selected as the standard field based on the field group analysis information.

[0017] According to the fourth invention, in addition to the effects of the first invention, when setting basic fertilizer amounts for multiple fields, even for fields that were not selected as standard fields, the amount can be automatically set based on field group analysis information, thereby reducing the burden on workers and improving convenience. Effect of the Invention

[0018] According to the present invention, it is possible to provide a work vehicle that reduces the workload of having to prepare a fertilization map for each of a plurality of fields, and enables fertilization work by flexibly changing the method of determining the amount of fertilizer to be applied for each field. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a left side view of a work vehicle according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic left side view of the fertilizer application device of FIG. [Diagram 3] FIG. 3 is a schematic plan view of the portable information terminal of FIG. [Figure 4] FIG. 4 is a block diagram showing the configuration of a control system of the portable information terminal of FIG. [Diagram 5] FIG. 5 is an explanatory diagram for explaining the procedure for creating fertilization map information. [Figure 6] FIG. 6 is an explanatory diagram for explaining the data contents of the information of the soil information-based fertilization map. [Figure 7] FIG. 7 is a schematic plan view showing an example of a managed farm field. [Figure 8] FIG. 8 is an explanatory diagram illustrating the data contents of the group of farm fields information and group of farm fields analysis information. [Figure 9] FIG. 9 is a block diagram showing the configuration of a control system including the control device of FIG. [Figure 10] FIG. 10 is an explanatory diagram for explaining a target travel route of a work vehicle. [Figure 11] FIG. 11 is a flowchart showing the flow of processing when setting a basic fertilizer amount. [Figure 12] FIG. 12 is a flowchart showing the flow of the fertilization mode automatic switching process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0021] First, the basic configuration of the work vehicle 1 will be described below.

[0022] <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.

[0023] In this specification, the side in the traveling direction of the work vehicle 1 is defined as the front as shown by the arrow in Figure 1, and unless otherwise specified, the left side in the traveling direction of the work vehicle 1 is referred to as the "left" and the opposite side is referred to as the "right." The work vehicle 1 is also referred to simply as the "machine body."

[0024] The work vehicle 1 according to this embodiment has the configuration of a rice transplanter, as an example. Specifically, as shown in Fig. 1, the basic configuration includes a traveling vehicle body 2 (hereinafter, simply referred to as "vehicle body") that travels in a field, and the traveling vehicle body 2 is equipped with a seedling planting unit 3 that plants seedlings in the field, a fertilizer applicator 4 that fertilizes the field, a positioning device 5 that measures the position of the vehicle body, a soil information acquisition unit J that acquires soil information of the field, and a control device C that controls various mechanisms of the work vehicle 1. In addition, the work vehicle 1 is equipped with a mobile information terminal 6 (see Figs. 3 and 5) that allows the worker to remotely operate the work vehicle 1.

[0025] <Configuration of the running vehicle> The traveling body 2 is a travelable body that forms the main body of the work vehicle 1. This traveling body 2 is equipped with a main frame 2a that forms the vehicle body skeleton and extends in the fore-and-aft direction of the vehicle, and a rear frame 2b that is attached to the rear end of this main frame 2a and extends in the width direction. A floor step 2c on which an operator can board is provided on the upper part of this main frame 2a, and a control unit 7 that controls operation and a control seat 7g in which the operator sits are provided on this floor step 2c.

[0026] In addition, the engine E, which is the power source of the traveling vehicle body 2, is arranged below the driver's seat 7g, and the power output from the engine E is transmitted from a hydrostatic continuously variable transmission (HST) e2 to a transmission case e3 via a belt-type power transmission mechanism e1 provided below the floor step 2c, as shown in Figure 1.

[0027] The hydrostatic continuously variable transmission e2 is a mechanism in which the opening of a trunnion shaft (not shown) is adjusted by the drive of an HST servo motor e4 (see FIG. 2) to change the output to the transmission case e3, thereby making it possible to adjust the vehicle speed.

[0028] The power transmitted to the transmission case e3 is changed in speed therein, and is then branched and transmitted to a pair of left and right front wheels 9 and a pair of left and right rear wheels 10 for traveling, and to the seedling planting section 3 for working. The power for traveling is transmitted to the pair of left and right front wheels 9 via the front wheel final case e5 and the front wheel axle e6 (see FIG. 1), and is also transmitted to the pair of left and right rear wheels 9 via the pair of left and right rear wheel transmission shafts e7, the pair of left and right rear wheel gear cases e8, and the rear wheel axle 82 shown in FIG. 1. On the other hand, the working power is transmitted to a planting clutch (not shown) provided at the rear of the traveling body 2, and when the planting clutch is engaged by a predetermined operation, it is further transmitted to the seedling planting section 3.

[0029] The control section 7 is provided with various operating members that are operated by the operator. Specifically, it is provided with a main speed change lever 7a that changes the forward / reverse movement and vehicle speed of the traveling body 2, a steering wheel 7b that steers a pair of left and right front wheels 9, a straight-line assist lever 7c that causes the control device C to start or end straight-line control, which is one of the automatic driving methods, and an operation panel 7d provided with various operation switches. Furthermore, the operation panel 7d is provided with a monitor 7e that can display various information. In addition to the steering wheel 7b, the control section 7 is provided with a steering shaft 7f, a pitman arm, a tie rod (not shown), and the like as a steering mechanism for steering the work vehicle 1, and these mechanisms change the steering angle of the front wheels 9, which are steered wheels, in response to the rotation operation of the steering wheel 7b. In addition, a driver's seat 7g is provided behind the steering wheel 7b.

[0030] <Configuration of the seedling planting section> The seedling planting section 3 is attached to the rear of the traveling body 2 via a lifting link device 11. The lifting link device 11 includes an upper link arm 11a and a pair of lower link arms 11b on the left and right, and is configured to be able to lift and lower the seedling planting section 3.

[0031] The front ends of the upper link arm 11a and the lower link arm 11b are attached to a link base frame 12 fixed to the rear frame 2d, and the other ends are attached to the upper and lower link arms 13 located at the bottom of the seedling planting section 63.

[0032] Here, when the electronic hydraulic valve (not shown) is controlled by the control device C and the lifting hydraulic cylinder 14 shown in Fig. 1 is hydraulically contracted, the upper link arm 11a is rotated upward and rearward, and the seedling planting unit 3 is raised to the non-working position. When the seedling planting unit 3 is in the non-working position, its lower end is located at approximately the same height as the bottom of the main frame 2a.

[0033] In contrast, when the lifting hydraulic cylinder 14 is hydraulically extended, the upper link arm 11a is rotated backward and downward, and the seedling planting section 3 is lowered to a working position (the position shown in Figure 1) where seedling planting work can be performed.

[0034] As shown in Figure 1, the seedling planting section 3 is equipped with a seedling support 3a on which mat-like seedlings with soil (so-called seedling mats) are placed, a planting device 3b provided behind and below the seedling support 3a, a center float 3c provided at the bottom of the seedling planting section 3b, and side floats 3d arranged on the left and right sides of the center float 3c.

[0035] The planting devices 3b are arranged in a line in the width direction of the work vehicle 1, and each planting device 3b is equipped with two pairs of planting tools 3e arranged in the front-rear direction. When the planting clutch is engaged and the drive shaft 3f shown in Fig. 1 is rotated, the front planting tool 3e and the rear planting tool 3e shown in Fig. 1 rotate around the drive shaft 3f, alternately picking up seedlings located at the lower end of the seedling carrier 3a and planting them in the field.

[0036] The center float 3c and the side float 3d are each configured to slide over the field and level the ground as the work vehicle 1 travels, and seedlings are planted by each planting device 3b in the field leveled by each float 3c, 3d. In addition, the center float 3c and the side float 3d are each configured to be able to swing in accordance with the unevenness of the field.

[0037] <Fertilizer application device configuration> FIG. 2 is a schematic left side view of the fertilizer application device 4 shown in FIG.

[0038] The fertilizer application device 4 comprises an air chamber 4a extending in the left-right direction of the body, a blower 4b that pressurizes air from left to right through the air chamber 4a, a fertilizer application hopper 4c that stores fertilizer to be supplied to the field, a plurality of feed devices 4d provided below the fertilizer hopper 27, a plurality of connecting pipes 4e provided below each feed device 4d and with front ends connected to the air chamber 4a, and a plurality of fertilizer application hoses 4f connected to the rear ends of each connecting pipe 4e and extending to the bottom of the seedling planting section 3.

[0039] The blower 4b includes an intake duct 4g, and when a blower motor (not shown) is driven, air is sucked in through the intake duct 4f and supplied into the air chamber 4a. The air supplied into the air chamber 4a is supplied into each of the fertilizer hoses 4f through each of the connecting pipes 4e while being pumped to the right.

[0040] Each of the payout devices 4d has an opening at the top to receive the fertilizer dropped from the fertilizer hopper 4c, and has a payout roll 4i with a payout groove 4h on its outer circumferential surface. The payout roll 4i rotates as the payout shaft 4j inserted in a hole (not shown) penetrating each payout roll 4i in the left-right direction rotates. As a result, the fertilizer in the payout groove 4h is paid out downward from the payout device 4d. The fertilizer paid out by the payout roll 4i is supplied into the connecting pipe 4e. At this time, the fertilizer supplied into the connecting pipe 38 is supplied to the field through the fertilizer hose 6f by air supplied from the air chamber 4a in front.

[0041] Here, the rotation speed of the fertilizer amount adjustment motor 4m that rotates the payout shaft 4j is controlled by the control device C. That is, since the amount of fertilizer paid out by the payout device 4d is determined according to the rotation speed of the payout roll 4i, the control device C can control the amount of fertilizer applied by the fertilizer application device 4 by controlling the fertilizer amount adjustment motor 4m. The amount of fertilizer is, more specifically, the weight of fertilizer supplied per unit area of ​​the field, and is determined, for example, by kg of fertilizer supplied per 10a (1 are). Therefore, the control device C controls the rotation speed of the payout roll 4i according to the target amount of fertilizer application so that it becomes a target speed calculated based on the target amount of fertilizer application. The rotation speed of the payout roll 4i is controlled so that the greater the target amount of fertilizer application, the faster the speed becomes, and the smaller the target amount of fertilizer application, the slower the speed becomes.

[0042] <Configuration of positioning device> The positioning device 5 is configured to include a GNSS receiver with a receiving antenna that receives radio waves from GNSS satellites, and an inertial measurement module that detects the inclination and acceleration of the three axes of the vehicle body. This positioning device 5 is disposed at the upper end of a frame material that extends upward in the front part of the traveling vehicle body 1, and serves the function of acquiring vehicle body position information. Here, position information refers to information indicating the position of the work vehicle 1, and includes at least information indicating the latitude and longitude of the vehicle body. The position information measured by the positioning device 5 is transmitted to the control device C (see FIG. 5).

[0043] <Configuration of soil information acquisition unit> The soil information acquisition unit J acquires information (hereinafter referred to as soil information) indicating the fertility of the soil (i.e., the ease of growing crops) by measuring the soil in the field. The soil information acquisition unit J includes a cultivated soil depth sensor j1 that measures the cultivated soil depth (i.e., the depth of the cultivated soil layer) and a fertility sensor j2 that measures the fertility of the soil. The cultivated soil depth sensor j1 is an ultrasonic sensor provided at the front of the traveling body 2, and is capable of measuring the cultivated soil depth by measuring the depth to which the vehicle body has sunk to the hard bed. The fertility sensor j2 is provided at the front wheel 9, and is capable of measuring the fertility of the soil by passing a weak current through the soil and measuring the ions (nutrients) in the soil from the electrical conductivity (electrical resistance). More specifically, the SFV value (Soil Fertility Value) is measured as an index of fertility. This SFV value is a numerical value equivalent to the EC value (Electric Conductivity), and its unit is mS / cm (milliSiemens). The measurement information (cultivated soil depth, SFV value) of the soil information acquisition unit J is linked to the position information (for example, latitude, longitude) of the point measured by the positioning device 5 and transmitted to the control device C at a predetermined time interval.

[0044] <Mobile information terminal configuration> 3 is a schematic plan view of the portable information terminal of FIG. 1, and FIG. 4 is a block diagram showing the configuration of a control system of the portable information terminal of FIG.

[0045] The mobile information terminal 6 is an information processing device separate from the traveling vehicle body 2, and is, for example, a smartphone, tablet, or other information processing device that can be carried by an operator. Although not shown, the mobile information terminal 6 is configured with a CPU that performs arithmetic processing and a memory that can read and write information required for the arithmetic processing, and the configuration shown as functional blocks in Fig. 4 is realized by the CPU operating according to various control programs stored in the memory.

[0046] As shown in Figures 3 and 4, the portable information terminal 6 is equipped with a display unit 6a, an operation unit 6b, an NDVI value acquisition unit 6c, a fertilization map creation unit 6d, a soil information utilization fertilization map creation unit 6e, a field information management unit 6f, and a communication control unit 6j.

[0047] The display unit 6a has a function of outputting video and audio, and is constituted, for example, by a liquid crystal panel having a speaker. The operation unit 6b is constituted by a plurality of pressure-detecting buttons, etc. The fertilization map 6c serves to set a fertilization map Dh, which will be described later, in the fertilization map storage unit 6c and the control device C. Data relating to the fertilization map Dh may be configured to be acquired from an external server SV, or may be configured to be capable of generating data based on the operation of the operation unit 6b, and configured to be set by the operator's operation of the operation unit 6b related to setting the fertilizer amount.

[0048] The fertilization map storage unit 6d is a memory having a storage area, and is configured with a RAM or the like, but may be configured with a removable recording medium such as an SD card. In the fertilization map storage unit 6c, data of a fertilization map Dh, which will be described later, is stored in advance before the start of work.

[0049] The NDVI value acquisition unit 6e has a function of acquiring an NDVI value (Normalized Difference Vegetation Index) of the field to be worked on. The NDVI value is calculated from the infrared reflectance and the like for each point of the field based on, for example, a satellite image of the field before the harvest of the previous year in which the field where the seedlings are planted is captured. The satellite image of the field before the harvest of the previous year in which the field where the seedlings are planted is captured is acquired from an external server SV connected via a network NW. The NDVI value is expressed as an integer value of 0 to 200, and it is estimated that the larger the value, the higher the fertility of the soil. Information on the calculated NDVI value of the field is linked to the data of the fertilization map Dh for each point of the field and stored in the fertilization map storage unit 6d. As a result, the data of the fertilization map Dh is configured to include information on the NDVI value of the field.

[0050] <Fertilization map> The fertilization map creation unit 6d has a function of creating information of the fertilization map Dh. Fig. 5 is an explanatory diagram for explaining the procedure for creating the information of the fertilization map. The procedure for creating the fertilization map Dh by the fertilization map creation unit 6d will be described below with reference to Fig. 5.

[0051] First, the fertilization map creation unit 6d acquires information on the NDVI value map Dn from the NDVI value acquisition unit 6e. This NDVI value map Dn is data in which an NDVI value is set for each point P of the field, and is configured to include at least information indicating the field area, position information of each point in the field area, and information on the NDVI value set for each point in the field. Any point P in the approximately rectangular field area R indicating the field area can be specified by two-dimensional coordinates X and Y corresponding to the latitude and longitude of the point P.

[0052] Next, a conversion NDVI value map Dn2 is created to convert the information of the NDVI value map Dn into information of the fertilization map Dh. Here, the fertilization map Dh is data in which a target fertilization amount is set for each section of the field, and is configured to include at least information indicating the area of ​​the field, position information of each point in the area of ​​the field, and information on the target fertilization amount set for each section of the field.

[0053] In detail, as shown in Fig. 5, the fertilization map Dh is configured such that any point within a substantially rectangular field area R indicating the field area can be specified by two-dimensional coordinates X, Y corresponding to the latitude and longitude of the point. This allows a point within the field area R to be specified from position information indicating the latitude and longitude of the machine within the field.

[0054] Furthermore, the field region R is divided into rectangular sections K2 of a predetermined size in a matrix. The fertilization map Dh is configured to include, for each section K2, a section number for identifying the section, the section's range on the two-dimensional coordinate system (range X, range Y), and information on the target fertilizer amount M and NDVI value set for the section K. The target fertilizer amount M is the target fertilizer amount (control amount) of the fertilizer application device 4, and is set, for example, in kilograms of fertilizer per 10 a (ares).

[0055] With this data configuration, the control device C can refer to the fertilization map Dh to identify the section K2 to which any point in the field to be worked belongs from the position information of the point, obtain information on the target fertilizer amount M set for the identified section, and control the amount of fertilizer applied by the fertilizer application device 4 so that the obtained target fertilizer amount M is achieved.

[0056] Therefore, the conversion NDVI value map Dn2 is configured to divide the field area R of the NDVI value map Dn into a matrix shape in accordance with the fertilization map Dh, assign a partition number to each partition K, calculate the average value of the NDVI values ​​of the points included in that partition, and set an average NDVI value which is the calculated average value.

[0057] Next, the fertilization map Dh is created by converting the average NDVI value into the target fertilization amount M for each section K. Here, the target fertilization amount M for each section K2 is determined by a predetermined calculation method based on the average NDVI value of each section K2. The higher the average NDVI value, the more fertile the soil of the section is estimated to be, so the value of the target fertilization amount M is set lower. The target fertilization amount M for each section K2 of the fertilization map Dh can be changed by the operator as appropriate by operating the mobile information terminal 6. This makes it possible to set the fertilization amount for each section of the field, taking into account fertility, etc. The information of the fertilization map Dh created in this way is stored in the field group information management unit 6f, which will be described later. It is also transmitted to the control device C and stored in the information storage unit c5, which will be described later.

[0058] <Fertilization map using soil information> The soil information-based fertilization map creation unit 6e functions to create a soil information-based fertilization map Dj. Fig. 6 is an explanatory diagram explaining the data contents of the information of the soil information-based fertilization map Dj. As shown in Fig. 6, in the soil information-based fertilization map Dj, the field area R is divided into rectangular sections K3 of a predetermined size in a matrix pattern corresponding to the sections K2 of the fertilization map Dh. In other words, the sizes and ranges of the sections K2 and K3 are designed to be the same. A soil information-based fertilization amount M2 is then set for each section K3.

[0059] Here, the soil information-based fertilization amount M2 is set by calculating the average value of the fertilization amount calculated by the calculation method of the soil information-based fertilization mode described later for each section of the field. That is, the soil information-based fertilization map creation unit 6e acquires the fertilization amount calculated by the calculation method of the soil information-based fertilization mode from the control device C at a predetermined time interval together with the position information, determines which section K3 the machine belongs to based on the position information of the machine, calculates the average value by accumulating the fertilization amount for each section K3, and sets the calculated average value as the soil information-based fertilization amount M2 for each section K3, thereby making it possible to create the soil information-based fertilization map Dj. The created soil information-based fertilization map Dj is stored in the field group information management unit 6f described later. In addition, the mobile information terminal 6 is configured so that the operator can display the fertilization map Dh and the soil information-based fertilization map Dj stored in the field group information management unit 6f on the display unit 6a and compare them by performing a predetermined operation. This makes it possible to compare fertilizer amounts calculated using different calculation methods and to analyze the fertilization method that is most suitable for each field.

[0060] The field group information management unit 6f has the function of managing information about multiple fields (hereinafter also referred to as managed fields) that are the target of work. Note that a group of fields means multiple fields. The field group information management unit 6f includes a field group information creation unit 6g that creates field group information DG, a field group analysis information creation unit 6h that creates field group analysis information DA, and a field group information storage unit 6i that stores information about the managed fields.

[0061] Fig. 7 is a schematic plan view showing an example of a managed field, and Fig. 8 is an explanatory diagram explaining the data contents of the field group information and the field group analysis information. The field group information DG created by the field group information creation unit 6g is a compilation of information on the managed fields, and for each field, information such as a cultivated soil depth map Ds, which is a map of measurements acquired by the cultivated soil depth sensor j1 compiled together with position information, an NDVI value map Dn, a fertilization map Dh, a soil information-based fertilization map Dj, a lodging position map Ds, a basic fertilization amount, a total fertilization amount, and a total yield is compiled. The lodging position map Dj is a map showing the lodging position of seedlings, and is created, for example, by image analysis of a satellite image of a field before harvesting in the previous year, in which the field where seedlings are planted is captured. In the illustrated example, information on the three fields H1, H2, and H3 shown in FIG. 7 is compiled into field group information DG shown in FIG.

[0062] The field group analysis information creation unit 6h creates field group analysis information DA based on the field group information DG. The created field group analysis information DA is configured so that the operator can display and check it on the display unit 6a by a predetermined operation. This can be useful for analyzing fertilization methods suitable for each of a plurality of fields. The field group analysis information DA includes, for example, an NDVI value map average value indicating the average NDVI value of the entire field in the NDVI value map Dn, a fertilization map average value indicating the average target fertilization amount M of the entire field in the fertilization map Dh, and a fertility rank (for example, a five-level evaluation of S, A, B, C, and D) indicating an evaluation of the fertility of the field determined from the values ​​of the NDVI value map average value and the fertilization map average value.

[0063] The created field group information DG and field group analysis information DA are stored in the field group information storage unit 6i, and are configured so that the worker can display and check them on the display unit 6a by a predetermined operation. This can be useful for analyzing the fertilization method suitable for each of the multiple fields. The field group analysis information DA is data compiled for each field (fields H1, H2, and H3), but data that summarizes multiple fields may be created. For example, data is created by adding up or calculating the average value of the values ​​of the fields H1, H2, and H3, which can be used to analyze the entire field (fields H1, H2, and H3). The worker may select the fields for which the sum or average value is to be calculated from the multiple fields (for example, fields H1 and H3) and create data. This makes it easy to analyze the fields in each location (e.g., multiple fields belonging to area 1 and multiple fields belonging to area 2) even when there are multiple fields located far apart (e.g., area 1 and area 2).

[0064] Furthermore, the mobile information terminal 6 can transmit and receive various information to and from the work vehicle 1 and the external server SV by wireless communication via the network NW using the communication control unit 6f. The operation information of the operation unit 6b is transmitted to the control device C of the work vehicle 1, and the control device C executes various processes according to the acquired operation information. This allows the worker to operate the mobile information terminal 6 to remotely give various instructions and make various settings, such as starting work, starting travel, moving forward / backward, and stopping, without getting on the work vehicle 1.

[0065] <Control device configuration> FIG. 9 is a block diagram showing the configuration of a control system including the control device C of the work vehicle 1. As shown in FIG.

[0066] The control device C is an information processing device configured by combining multiple ECUs (Electronic Control Units). Each of the multiple ECUs is configured with a CPU that performs arithmetic processing and a memory that can read and write information required for the arithmetic processing, and the configuration shown as functional blocks in Fig. 2 is realized by the CPU operating according to various control programs stored in the memory.

[0067] As shown in Figure 5, the control device C is equipped with an output processing unit c1, a communication processing unit c2, an input processing unit c3, a driving control unit c4, an information storage unit c5, a driving management unit c6, a fertilizer amount setting unit c7, and a fertilizer application device control unit c8, and these are configured to be able to send and receive information to each other via a communication bus BA.

[0068] The output processing unit c1 functions as an input / output interface, and is connected to a traveling system device group M1 that controls traveling functions such as driving, stopping, and changing the traveling direction of the work vehicle 1, a working system device group M2 that controls work functions such as fertilizing and planting, and a monitor 7e that outputs video and audio. For example, in this embodiment, the traveling system device group M1 includes mechanisms such as a steering actuator, an engine E, a transmission, and a brake, and the working system device group M2 includes mechanisms such as a PTO clutch, a PTO transmission, a braking device, and a lifting hydraulic cylinder 14.

[0069] The communication processing unit c2 is a communication mechanism that connects to an external device physically separated from the control device C via a network NW and exchanges information through communication. In this embodiment, the communication processing unit c2 is connected to, for example, a mobile information terminal 6, and is capable of sending and receiving various information.

[0070] The input processing unit c3 is a mechanism for receiving information input from a connected external device, and is capable of acquiring various information such as positioning information, detection information, etc. In this embodiment, the input processing unit c3 is connected to the positioning device 5, the traveling system detection sensor S1 including the steering angle detection means, the seedling planting unit 3, the work system detection sensor S2 including various sensors for detecting the operating state of the fertilizer application device 4, and the soil information acquisition unit J.

[0071] The control device C also includes a travel control unit c4 that controls the travel of the work vehicle A, an information storage unit c5 that stores various information, and a route management unit c6 that performs processing related to the target travel route L.

[0072] The driving control unit c4 is a mechanism including a program and various circuits that control the driving of the work vehicle 1 during automatic driving (automatic steering) and manual driving (manual steering), and is equipped with an automatic driving control device c41 that controls the driving system equipment group M1 during automatic driving, and a manual driving control device c42 that controls the driving system equipment group M1 during manual driving.

[0073] The automatic driving control device c41 includes an own vehicle position calculation unit c411 that calculates the own vehicle position in the field by acquiring positioning information (position information) from the positioning device 5, an own vehicle orientation calculation unit c412 that calculates the own vehicle orientation, a deviation calculation unit c413 that calculates a deviation, and a steering angle calculation unit c414 that calculates a steering angle from detection information of the driving system detection sensor group S1. The automatic driving control device c41 configured in this manner calculates a deviation using the deviation calculation unit c413, calculates a steering angle of the steering wheel 7b appropriate for the work vehicle 1 to travel along the target driving path L based on the calculated deviation, and controls the steering actuator to achieve the calculated steering angle, thereby enabling the work vehicle 1 to automatically travel on the target driving path L.

[0074] The information storage unit c5 is a storage device capable of storing various information, and is configured, for example, with an HDD (Hard Disc Drive) or SSD (Solid State Drive). The information storage unit c5 includes a field information storage unit c51 that stores information on the field (hereinafter referred to as "field information"), a route information storage unit c52 that stores information on the travel route of the work vehicle 1 (hereinafter referred to as "route information"), and a work information storage unit c53 that stores setting information on the work (hereinafter referred to as "field information"). The information stored in the information storage unit c5 can be acquired by the mobile information terminal 6 via the network NW, and the acquired information can be displayed on the display unit 6a to enable the worker. This allows the worker to analyze the field and the work.

[0075] The field information storage unit c51 is a memory area for storing field information, which includes, for example, the size, shape, and position of the field to be worked on, as well as the position data of the ridges that define the boundaries of the field.

[0076] The route information storage unit c52 is a storage area for storing route information. Here, the route information includes information related to the travel route of the work vehicle 1, such as position information indicating a target travel route L described below.

[0077] The work information storage unit c53 is a memory area for storing work information. Here, the work information includes setting information related to the work of the work vehicle 1, such as the work width W preset by the worker, the type of work (fertilization, planting, etc.), etc.

[0078] The travel management unit c6 is a program that manages the travel of the work vehicle 1, and includes a route calculation unit c61, a travel order setting unit c62, and a stop position setting unit c63.

[0079] The path calculation unit c61 calculates a target travel path L based on the field information, the work information, and the like.

[0080] 10 is an explanatory diagram for explaining a target driving route of the work vehicle 1. Here, the target driving route L refers to a driving route that is a target of the work vehicle 1 during automatic driving, and information indicating the target driving route L includes position information indicating the trajectory of the target driving route L. The route calculation unit c61 calculates the target driving route L, for example, in the following design procedure.

[0081] First, field information is acquired and the field area R is divided into a headland traveling area R1 where work is performed by traveling in a circular manner, and a straight-line traveling area R2 where work is performed by traveling in a straight line. Here, the headland traveling area R1 is set as a frame-shaped area having a working width W, and a rectangular straight-line traveling area R2 is set inside the headland traveling area R1. The field area R is an area that indicates the field, and the shape and size of the area are designed to correspond to the shape and size of the field.

[0082] Next, a headland travel path l1 that travels in a circular manner within the headland travel area R1 is designed (work paths VI to IX). Then, a plurality of straight-line travel paths l2 that travel in a straight line within the straight-line travel area R2 are designed (work paths I to V). Here, the straight-line travel paths l2 are spaced apart at approximately the same interval as the work width W to prevent overlapping work from being performed at the same point.

[0083] Next, a non-work route l3 is designed, which is a route that does not involve work, for moving between the straight-line travel routes l2 in a single stroke, turning between the straight-line travel routes l2, and moving from the straight-line travel route l2 to the headland travel route l1. Information indicating the target travel route L calculated as above is stored in the route information storage unit c52.

[0084] The travel order setting unit c62 acquires information indicating the target travel route L calculated by the route calculation unit c61, and sets the travel order of the work route (work routes I to IX in the illustrated example) which is a route along which work is performed that is included in the target travel route L. The travel order is set based on a predetermined rule, but the worker can also change it to an arbitrary travel order by operating the mobile information terminal 6 or the operation panel 7d. The setting information of the travel order is stored in the route information storage unit c52 together with information indicating the target travel route L.

[0085] For example, in the illustrated example of FIG. 10, the travel order is set in the order of work path I, work path II, work path III, work path IV, work path V, work path VI, work path VII, work path VIII, and work path IX. The directions of the arrows of the headland travel path l1 and the straight travel path l2 shown in the figure indicate the direction of travel of the work vehicle 1, but depending on the travel order, the direction is not necessarily limited to this direction. When the automatic travel of the work vehicle 1 starts, the work vehicle 1 is moved to the vicinity of the work start point Ps. This movement is performed by the operator, but the work vehicle 1 may be automatically traveled based on the position information of the work start point Ps. In addition, when the work vehicle 1 reaches the work end point PE of the straight travel path l2 in FIG. 6, it is configured to move from the straight travel path l2 to the headland travel path l1 via the non-work path l3, but depending on the travel order, it can also be configured to move from the headland travel path l1 to the straight travel path l2.

[0086] The stop position setting unit c63 sets a position where the work vehicle 1 temporarily stops during automatic driving on the target driving route L. The stop position is set based on a predetermined rule, but the worker can also change the set stop position by operating the mobile information terminal 6 or the operation panel 7d. Information about the set stop position is stored in the route information storage unit c52. When the work vehicle 1 reaches a stop position during automatic driving, the automatic driving is temporarily stopped. After the temporary stop, the automatic driving is resumed by instructing the work vehicle 1 to resume driving by a predetermined operation of the mobile information terminal 6. This allows the worker to check the remaining amount of fuel, fertilizer, seedlings, etc. of the work vehicle 1 at the stop position, and to replenish materials if necessary.

[0087] The stop positions can be set at the terminal positions of work paths I to IX, and in the illustrated example, are set at terminal positions Pm1 and Pm2 of work paths II and IV on one end of the field (i.e., the side that is easy for the worker to see). Note that the stop positions may also be set at the terminal positions of work paths I, III, and V on the other end of the field.

[0088] In addition, the stop position setting unit c63 is configured to skip the set stop position (continue automatic driving without stopping) when the mobile information terminal 6 is operated in a predetermined manner during automatic driving of the work vehicle 1. The number of skips can be accumulated and reserved before reaching the stop position, and the number of skips is stored in the work information storage unit c53 each time. For example, the number of skips for the stop position can be increased by one by simultaneously pressing the "F" button, the "Right" and the "Decision" buttons on the operation unit 6b. Furthermore, the number of skips for the stop position can be decreased by one by simultaneously pressing the "F" button, the "Left" and the "Back" buttons on the operation unit 6b. This allows the number of stops for material supply to be flexibly changed depending on the size of the field, for example.

[0089] The fertilizer amount setting unit c7 is a program that serves to set the amount of fertilizer, and includes a basic fertilizer amount setting unit c71 and a soil information learning unit c72.

[0090] The basic fertilizer amount setting unit c71 is a program that performs the function of setting a basic fertilizer amount. The basic fertilizer amount can be set by operating the mobile information terminal 6 or the operation panel 7d, and the set value of the basic fertilizer amount is stored in the work information storage unit c53 and is referred to when necessary during fertilization work. Here, the basic fertilizer amount is the basic fertilizer amount for the field to be worked on, in other words, the basic value of the fertilizer amount set for each field. The basic fertilizer amount is set, for example, in kilograms of fertilizer per 10 ares.

[0091] <Setting the basic fertilizer amount> FIG. 11 is a flowchart showing the flow of processing when setting a basic fertilizer amount.

[0092] The basic fertilizer amount setting unit c71 is capable of setting basic fertilizer amounts collectively for a plurality of fields (managed fields) by the following procedure.

[0093] As shown in Fig. 1, first, a field to be set (standard field) is selected from the managed fields (step #1). When a standard field is selected (for example, field H1 in Fig. 7), a reference fertilizer amount to be used as a reference when setting the basic fertilizer amount is displayed on the display unit 6e or monitor 7e (step #2). The reference fertilizer amount is, for example, the fertilizer map average value included in the field group analysis information DA of the field selected as the standard field (for example, 35 kg / 10a in the case of Fig. 8).

[0094] Next, when the operator inputs the basic fertilizer amount for the standard field, this is set in the field information storage unit c51, and based on the information regarding the input and set basic fertilizer amount, the data contents of the basic fertilizer amount item in the field group information DG in the field group information memory unit 6i are also updated (step #3).

[0095] Next, based on the basic fertilizer amount of the standard field that has been input, candidates for the basic fertilizer amount of fields other than the standard field (for example, fields H1 and H2 in FIG. 7) are calculated (step #4). The candidate basic fertilizer amount calculated at this time is calculated, for example, by comparing the average NDVI value map value of the field group analysis information DA. In the example of FIG. 8, the basic fertilizer amount of the standard field H1 is input as 40, and the average NDVI value map value of field H1 is 120 and that of field H2 is 100, so the candidate basic fertilizer amount of field H2 is calculated as 40×120 / 100=48. Note that the calculation method is not limited to this. In a similar manner, a candidate basic fertilizer amount is also calculated for field H3.

[0096] Next, the basic fertilizer amount setting unit c71 determines whether the calculated candidate for the basic fertilizer amount is within the range from the upper limit value to the lower limit value (step #5). The upper limit value and the lower limit value are set to desired values ​​by the operator. For example, the upper limit value is set to 80 kg / 10a, and the lower limit value is set to 30 kg / 10a.

[0097] When the basic fertilizer amount setting unit c71 determines that the calculated candidate basic fertilizer amount is not within the range from the set upper limit value to the set lower limit value (N in step #5), it corrects the candidate basic fertilizer amount so that it is within the range from the set upper limit value to the set lower limit value (step #6). For example, if the candidate basic fertilizer amount exceeds the set upper limit value of 80, it is corrected to 80, and if it is below the set lower limit value of 30, it is corrected to 30. At this time, for reference, the value before correction is also displayed on the display unit 6e or monitor 7e so that the operator can confirm it. This makes it possible to prevent a basic fertilizer amount value that deviates from the appropriate range from being set.

[0098] Finally, the basic fertilizer amount setting unit c71 sets the calculated basic fertilizer amount candidate (when Y in step #5) or the corrected basic fertilizer amount candidate (when N in step #5) as the basic fertilizer amount for each of the fields other than the standard field (fields H2, H3) in the information storage unit c51, and also updates the data content of the basic fertilizer amount item in the field group information DG in the field group information storage unit 6i based on the information on the set basic fertilizer amount (step #3). With the above configuration, when managing multiple fields, it is possible to eliminate the effort of setting a basic fertilizer amount for each field, reduce the workload of the worker, improve convenience, and set an appropriate basic fertilizer amount.

[0099] <Soil information learning (teaching)> The soil information learning unit c72 is a program that serves the function of learning (teaching) soil information. The soil information learning unit c72 manages the start and end of soil information learning, and stores the soil information (cultivated soil depth, SFV value) acquired from the soil information acquisition unit J during learning in the work information storage unit c53. Furthermore, each time soil information (cultivated soil depth, SFV value) is acquired, a growth evaluation value W is calculated using the cultivated soil depth and SFV value, and stored in the work information storage unit c53. Here, the growth evaluation value W indicates an evaluation value of the ease of seedling growth in the soil, and the higher the value, the easier the growth.

[0100] The growth evaluation value W can be calculated, for example, by the following formula (1).

[0101] (Formula 1) W = α × SFV value + β × soil depth α and β are weighting coefficients. As a result, the growth evaluation value W becomes larger as the SFV value becomes larger and as the cultivated soil depth becomes deeper.

[0102] The soil information learning unit c72 starts learning soil information when a preset start condition is satisfied, and ends learning soil information when a preset end condition is satisfied. The start and end conditions for learning soil information are set and stored in advance in the work information storage unit c53, but the worker can change the settings by operating the mobile information terminal 6 or the operation panel 7d.

[0103] The condition for starting learning soil information may be, for example, that automatic traveling has started. Alternatively, the condition may be that the start of any one of the work routes I to IX (which can be selected and set by the worker) on the target traveling route L, which is a route on which work is performed, has been reached (see FIG. 6). Alternatively, the condition may be that the start of any one of the work routes I to IX, which has been set in advance, has been reached on the target traveling route L.

[0104] The condition for ending the learning of soil information may be, for example, that automatic traveling has ended (traveling has stopped). Also, the condition may be that the end of any one of the work routes I to IX (which can be selected and set by the worker) on the target traveling route L, which is a route along which work is performed, has been reached. Also, the condition may be that the end of any one of the work routes I to IX on the target traveling route L that has been set in advance has been reached.

[0105] As a preferable condition for starting and ending the learning of soil information, for example, it is preferable to start learning soil information on the condition that the start of the third step (work path III) of the straight-line travel path l2 is reached after the start of the work by automatic travel, and end learning soil information on the condition that the end of the third step (work path III) of the straight-line travel path l2 is reached. Note that the third step is an example, and depending on the size of the field, the first step or the fourth step may be selected and set by the operator. This is because by learning soil information in one work step within the straight-line travel area R2, more accurate soil information of the entire field can be learned. Conversely, if soil information is learned near the edge of the field, for example, the measured value of the soil information may be biased due to the presence of a waterway beside the field, and it may not necessarily reflect the entire field.

[0106] Furthermore, regardless of the above conditions, the soil information learning unit c72 is configured to be able to start or end soil information learning at a timing desired by the operator through a predetermined operation (for example, pressing a button) of the mobile information terminal 6 or the operation panel 7d. This allows the operator to learn soil information at a place and time desired by the operator, improving convenience.

[0107] When the soil information learning unit c72 finishes learning the soil information, it calculates the average values ​​of the cultivated soil depth, the SFV value, and the growth evaluation value W during the learning, and stores them in the work information storage unit c53. In the following description, the average value of the growth evaluation value W calculated and stored in the work information storage unit c53 is referred to as the growth evaluation value W based on the learning result.

[0108] The fertilizer application device control unit c8 includes a fertilizer amount control unit c81, a fertilization mode execution unit c82, and a fertilization mode management unit c83.

[0109] The fertilizer amount control unit c81 is a program that transmits a control signal for controlling the amount of fertilizer to the fertilizer application device 4, thereby performing the function of controlling the amount of fertilizer applied by the fertilizer application device 4.

[0110] The fertilization mode execution unit c82 is a program capable of executing multiple fertilization modes with different methods for determining the fertilizer amount, and performs the function of determining the fertilizer amount of the fertilizer application device 4 during fertilization operations by passing information on the fertilizer amount (control amount) of the fertilizer application device 4 to the fertilizer amount control unit c81.

[0111] The fertilization mode execution unit c82 has, as executable fertilization modes (programs), a basic fertilization amount fertilization mode c821, a fertilization map usage fertilization mode c822, a soil information usage fertilization mode c823, and a hybrid fertilization mode c824.

[0112] <Basic fertilizer amount fertilization mode> The basic fertilizer amount fertilization mode c821 is a mode in which a preset basic fertilizer amount is determined as the fertilizer amount of the fertilizer application device 4. That is, while the basic fertilizer amount fertilization mode c821 is being executed (i.e., while the basic fertilizer amount fertilization mode is selected), the fertilizer amount of the fertilizer application device 4 is controlled to be the basic fertilizer amount, and is therefore usually constant. Note that the basic fertilizer amount appropriately refers to a value set in the work information storage unit c53. When the value set in the work information storage unit c53 is changed, the fertilizer amount of the fertilizer application device 4 is also changed.

[0113] <Fertilization mode using fertilization map> The fertilization map-based fertilization mode c822 is a mode in which the amount of fertilization by the fertilizer applicator 4 is determined based on information in the fertilization map Dh. That is, while the basic fertilizer amount fertilization mode c821 is being executed (i.e., while the fertilization map-based fertilization mode is selected), the amount of fertilization by the fertilizer applicator 4 is determined by the following procedure.

[0114] In this fertilization map-using fertilization mode c822, the fertilization device 4 acquires its own position information (latitude, longitude) from the positioning device 5 at predetermined time intervals, and each time, refers to the information on the fertilization map Dh, compares the position information on the fertilization map Dh with the position information acquired from the positioning device 5, and identifies a section K on the fertilization map Dh. Next, information on a target fertilization amount M set for the identified section K is acquired, and the acquired amount of fertilization is determined as the fertilization to be performed by the fertilization device 4.

[0115] <Fertilization mode using soil information> The soil information-based fertilization mode c823 is a mode for determining the amount of fertilization by the fertilizer application device 4 based on soil information. That is, while the soil information-based fertilization mode c821 is being executed (i.e., while the soil information-based fertilization mode is selected), the amount of fertilization by the fertilizer application device 4 is determined by the following procedure.

[0116] The soil information-based fertilization mode c823 acquires soil information from the soil information acquisition unit J at a predetermined time interval, and calculates a growth evaluation value W according to the above formula (1). Next, the calculated growth evaluation value W is compared with the growth evaluation value W according to the learning result stored in the work information storage unit c53, and the amount of fertilization by the fertilizer application device 4 is determined based on which is larger. The amount of fertilization determined by the soil information-based fertilization mode c823 can be calculated, for example, according to the following formula (2).

[0117] (Formula 2) Fertilization amount = Basic fertilizer amount × (100-fertilization reduction rate (%)) / 100 However, when the growth evaluation value W > the growth evaluation value W based on the learning results, the fertilizer reduction rate (%) = 20 x calculated growth evaluation value W / growth evaluation value W based on the learning results, and when the growth evaluation value W < the growth evaluation value W based on the learning results, the fertilizer reduction rate (%) = 0.

[0118] That is, the higher the calculated growth evaluation value W is compared to the growth evaluation value W based on the learning result, the more likely it is that the point where the soil information was acquired is more fertile than the average fertility of the entire field, so the fertilizer reduction rate (%) is increased and the amount of fertilizer applied is reduced. Conversely, if the calculated growth evaluation value W is lower than the growth evaluation value W based on the learning result, the point where the soil information was acquired is less fertile than the average fertility of the entire field, so the fertilizer reduction rate (%) is set to 0 and the basic amount of fertilizer is determined as the amount of fertilizer applied without reducing fertilizer. According to the soil information-based fertilization mode c824 configured in this way, it is possible to increase or decrease the amount of fertilizer applied, i.e., perform variable fertilization, while reflecting soil information measured in real time.

[0119] In addition, in the soil information using fertilization mode c824, immediately after work has started, when the soil information learning unit c72 has not yet learned soil information and the work information storage unit c53 does not contain information on the growth evaluation value W based on the learning results, the fertilizer reduction rate (%) = 0 and the basic fertilizer amount is determined as the fertilizer amount of the fertilizer application device 4 until the soil information learning unit c72 has completed learning of the soil information.

[0120] Note that the control device C is configured to calculate the amount of fertilization by the above-mentioned method in the soil information using fertilization mode c823 at predetermined time intervals even when the soil information using fertilization mode c824 is not being executed, and transmit the calculated amount of fertilization together with the location information to the mobile information terminal 6. This enables the mobile information terminal 6 to create the soil information using fertilization map Dj.

[0121] <Hybrid fertilization mode> The hybrid fertilization mode c824 is a mode in which the fertilization amount of the fertilizer application device 4 is determined using fertilization map information and soil information. More specifically, while the hybrid fertilization mode c824 is being executed (i.e., while the hybrid fertilization mode is selected), the fertilization amount is determined by combining the fertilization amount determined by the fertilization map-use fertilization mode c822 and the fertilization amount determined by the soil information-use fertilization mode c824.

[0122] Specifically, if the amount of fertilizer determined by the fertilization map-based fertilization mode c822 is M1 (kg / 10a) and the amount of fertilizer determined by the soil information-based fertilization mode c823 is M2 (kg / 10a), the amount of fertilizer determined by the hybrid fertilization mode c824 can be calculated, for example, by the following formula (3).

[0123] (Formula 3) Fertilization amount = (γ1×M1+γ2×M2) / 2 Here, γ1 and γ2 are weighting coefficients that can be set arbitrarily by the operator, and γ1+γ2=1. In setting the weighting coefficients, if the value of γ1 is increased, more importance is placed on the fertilizer amount M1 determined by the fertilization map-based fertilization mode c822, and if the value of γ2 is increased, more importance is placed on the fertilizer amount M2 determined by the soil information-based fertilization mode c823. This allows for finely tuned variable fertilization according to the operator's needs. In addition, the quality of fertilization can be improved by evaluating the field from multiple angles.

[0124] The fertilization mode management unit c83 performs the function of managing the fertilization mode executed by the control device C, and is equipped with a fertilization mode selection switching unit c831 and an automatic fertilization mode switching unit c832.

[0125] The fertilization mode selection switching unit c831 is a program that allows the operator to select a fertilization mode that can be executed by the above-mentioned fertilization mode execution unit c82 through a specified operation.For example, a list of selectable fertilization modes is displayed on the display unit 6a or monitor 7e of the mobile information terminal 6, and the operator can select the desired fertilization mode by operating the operation unit 6b or operation panel 7d, and the selected fertilization mode is executed by the fertilization mode execution unit c82.

[0126] <Fertilization mode automatic switching process> The automatic fertilization mode switching unit c832 is a program that performs a function of automatically switching the fertilization mode (hereinafter referred to as the automatic fertilization mode switching function), and the automatic fertilization mode switching function can be appropriately turned on and off by a predetermined operation of the operator. When the automatic fertilization mode switching function is turned on, the automatic fertilization mode switching unit c832 performs the following automatic fertilization mode switching process.

[0127] FIG. 12 is a flowchart showing the flow of the fertilization mode automatic switching process.

[0128] When the fertilization mode automatic switching unit c832 starts the fertilization mode automatic switching process, it executes the fertilization map utilization fertilization mode c822 (Step #11). As a result, fertilization is performed in the fertilization map utilization fertilization mode.

[0129] Next, it is determined whether the cultivated soil depth acquired by the soil information acquisition unit J (cultivated soil depth sensor j1) is equal to or greater than the set depth (step #12). If it is determined that the cultivated soil depth is equal to or greater than the set depth, the soil information-based fertilization mode c823 is executed (step #13). The set depth is set in advance by the operator. As a result, at points where the cultivated soil depth is deep, the fertilization mode is automatically switched to fertilization using the soil information-based fertilization mode. As a result, fertilization can be performed at points where the cultivated soil depth is deep by a method for determining the amount of fertilizer that takes the cultivated soil depth into account, so that lodging caused by overgrowth of seedlings due to deep cultivated soil depth can be effectively prevented. If the cultivated soil depth subsequently falls below the set depth, the fertilization mode using the fertilization map is resumed (N in step #12).

[0130] Furthermore, if soil information cannot be acquired (Y in step #14), that is, if the control device C cannot acquire soil information from the soil information acquisition unit J and it is determined that some malfunction has occurred, the fertilization mode automatic switching unit c832 executes the basic fertilizer amount fertilization mode c821 (step #15). This automatically switches the fertilization mode, and fertilization is performed in the basic fertilizer amount fertilization mode. As a result, even if some malfunction occurs in the soil information acquisition unit J and a malfunction occurs in the progress of fertilization in the soil information use fertilization mode, the fertilization work can be continued smoothly, and a decrease in work efficiency can be preferably prevented.

[0131] Thereafter, the process returns to step #14, and if it is determined that the soil information can be acquired without any problems (N in step #14), the process returns to the soil information-based fertilization mode (step #13).

[0132] The above describes the embodiments of the present invention. The present invention is not limited to the above-mentioned embodiments. It goes without saying that appropriate modifications may be made within the scope of the technical concept. For example, the basic fertilizer amount in the soil information-based fertilization mode may be determined using the fertilization map average value (see FIG. 8) of the field being worked on. Fields often have different geology, etc., depending on the region, and by determining the basic fertilizer amount taking into account the characteristics of each region and information obtained from outside (satellite), etc., it is possible to set an appropriate basic fertilizer amount for each region.

[0133] The basic fertilizer amount setting unit c71 may be configured to set the basic fertilizer amount for a standard field by referring to the basic fertilizer amount set for the field closest to the standard field. For example, in the illustrated example of FIG. 7, when the standard field is field H1, the distance D1 to field H2 and the distance D2 to field H3 are compared, and if the basic fertilizer amount is set for the closer field H2, this can be set as the basic fertilizer amount for field H1 of the standard field. This can improve convenience.

[0134] <Other> The following configurations can also be added:

[0135] In the robotic rice transplanter, when a specific remote control operation is performed after ridge-building, the robot transitions to a state in which it can replenish herbicides. By being able to replenish herbicides using the following procedure, the robotic rice transplanter is more convenient than ever before. (1) After furrowing, a specific operation (e.g., selection from the remote control menu screen) will switch to the herbicide supply state. (2) The turn will begin and then automatically pause at the appropriate time. (3) Adjust the position of the rice transplanter by controlling the forward and backward movement using the remote control, and lower the planting part by pressing the confirmation button. (4) Once herbicide replenishment is complete, press the F+Start button to resume automatic driving.

[0136] When the robotic rice transplanter transitions to herbicide supplying mode, it starts turning and is automatically paused "after the planting part starts to be lowered and before planting begins." After pausing, the herbicide supplying mode is canceled when the back button is pressed and held. Or, after the planting part is lowered, automatic driving is resumed when the F button + start button are pressed and held. Until then, the automatic driving resumption operation (F button + start button) is not accepted. [Explanation of symbols]

[0137] 1 Work vehicle 2 Running vehicle 2a Mainframe 2b Rear frame 2c Floor Step 3 Seedling planting department 3a Seedling stand 3b Planting equipment 3c Center Float 3d side float 3e planting tools 3f Drive shaft 4 Fertilizer application equipment 4a Air Chamber 4b Blower 4c Fertilizer hopper 4d feeding device 4e Connecting pipe 4f Fertilizer hose 4g Intake duct 4h feeding groove 4i Payout roll 4j Payload shaft 4m Fertilizer amount adjustment motor 5 Positioning device 6. Mobile Information Terminals 7. Control Section 7a Main gear shift lever 7b Steering wheel 7c Straight-line assist lever 7d control panel 7e Monitor 7f Steering shaft 7g Cockpit 9 Front Wheel 10 Rear wheel 11 Lifting link device 11a Upper link arm 11b Lower link arm 12 Link base frame 13 Upper and lower link arms 14 Lifting hydraulic cylinder C Control device E-Engine J Soil Information Acquisition Department

Claims

1. A work vehicle comprising a fertilizer applicator and a positioning device that acquires its own position, and configured to acquire a target fertilizer amount set for a section to which the own position belongs by utilizing a fertilization map in which a fertilizer amount is set for each section of a field based on the own position acquired by the positioning device, and to control the fertilizer amount of the fertilizer applicator, The method further includes a soil information acquisition unit that acquires soil information of the field, and a control device that controls the amount of fertilizer applied by the fertilizer application device. The soil information acquisition unit includes a tilled soil depth sensor that measures the tilled soil depth of the soil and a fertility sensor that measures the fertility of the soil, The fertilization map utilizing fertilization mode is configured to be executable by selecting a fertilization amount of the fertilization device based on the information of the fertilization map, and a soil information utilizing fertilization mode is configured to determine a fertilization amount of the fertilization device using soil information acquired from the soil information acquisition unit, The control device of the work vehicle is characterized in that, when the cultivated soil depth measured by the cultivated soil depth sensor becomes equal to or greater than a set depth while the fertilization map-based fertilization mode is being executed, the control device automatically switches to the soil information-based fertilization mode.

2. The work vehicle described in claim 1, characterized in that a soil information using fertilization map is created by calculating the average amount of fertilizer calculated by the soil information using fertilization mode for each plot of a field, and information about the fertilization map and information about the soil information using fertilization map are displayed on a display unit.

3. The control device includes a soil information learning unit that learns the acquired soil information, The fertilization map utilizing fertilization mode is configured to be able to acquire the soil information from the soil information acquisition unit, and determines the amount of fertilization of the fertilization device based on information of the fertilization map, The work vehicle according to claim 2, characterized in that the soil information utilization fertilization mode determines the amount of fertilization by the fertilizer application device by comparing soil information acquired from the soil information acquisition unit with soil information learned by the soil information learning unit.

4. A field group information management unit that manages information regarding managed fields, the group of fields information management unit includes a group of fields information creation unit that creates group of fields information, a group of fields analysis information creation unit that creates group of fields analysis information, and a group of fields information storage unit that stores information about managed fields; The control device is further configured to be able to execute a basic fertilizer amount fertilization mode in which a preset basic fertilizer amount is determined as the fertilizer amount of the fertilizer application device; A basic fertilizer amount setting unit that sets the basic fertilizer amount, The work vehicle described in claim 1, characterized in that when an operator selects a standard field from a plurality of fields included in the managed fields and sets a basic fertilizer amount, the basic fertilizer amount setting unit is configured to automatically set a basic fertilizer amount for fields that were not selected as the standard field based on the field group analysis information.

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