Work vehicles

Abstract

This invention provides a work vehicle that reduces the workload of having to prepare a separate fertilization map for each of the multiple fields, and allows for flexible adjustment of the method for determining the amount of fertilizer to be applied for each field. [Solution] A work vehicle equipped with a fertilizer application device and a positioning device, which controls the amount of fertilizer applied based on the target amount of fertilizer for the plot corresponding to the vehicle's position, using a fertilizer application map in which the amount of fertilizer applied is set for each plot of field, and is equipped with a soil information acquisition unit that acquires soil information of the field and a control device that controls the fertilizer application device, wherein the soil information acquisition unit has a fertilization sensor and is configured to select at least one of a fertilizer application mode that uses a fertilizer application map to determine the amount of fertilizer applied, and a soil information utilization fertilizer application mode that determines the amount of fertilizer applied based on soil information, and is configured to create a soil information utilization fertilizer application map which maps the amount of fertilizer applied for each plot determined by the soil information utilization fertilizer application mode, and is configured to display at least one of the fertilizer application map and the soil information utilization fertilizer application map on a display unit.

Description

Technical Field

[0001] The present invention relates to a work vehicle that performs fertilization while traveling in a field.

Background Art

[0002] In recent years, as the aging of farmers and the shortage of labor force have been regarded as problems, the average farmland area per selling farmer household in Japan has been on an increasing trend, and this trend is predicted to continue in the future. In response to this, the interest in smart agriculture that realizes ultra-low labor and high-quality production by utilizing robot technology and ICT has been increasing.

[0003] In such a trend, in the technical field of work vehicles for agricultural operations, for example, as shown in Patent Document 1 below, by using a positioning satellite system such as GPS and driving the work vehicle unmanned in the field, the work is made smarter.

[0004] By the way, leveling the growth of crops throughout the field has been a conventional problem in preventing crop lodging and the like. However, in the field, the environment for growing crops is not uniform, and it is normal for the ease of crop growth to vary depending on the location in the field. The larger the field area, the more likely the growth degree is to vary. Therefore, in the field, by increasing the fertilization amount in places where crops grow easily and decreasing the fertilization amount in places where crops grow difficultly, the growth of crops throughout the field is leveled. For example, as described in Patent Document 2 below, in the technical field of work vehicles that can travel unmanned, there is a known technique of automatically adjusting the fertilization amount of the work vehicle according to the position in the field using the information of a fertilization plan map in which the target fertilization amount is set for each predetermined section of the field. This fertilization plan map is data in which the position information of each section of the field and the target fertilization amount are linked and recorded. In sections where crops grow easily, the fertilization amount is set low, and in sections where crops grow difficultly, the fertilization amount is set high.

[0005] Using the information from this fertilization plan map, conventional work vehicles acquire their own position information at predetermined time intervals while working, identify the section of the field where they are working, and automatically control the fertilizer application device to achieve the target fertilizer amount associated with the identified section. As a result, conventional work vehicles can automatically adjust the fertilizer application amount for each section of the field while automatically driving around the field. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 11-266608 [Patent Document 2] Japanese Patent Publication No. 2021-101667 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, with conventional work vehicles, when fertilizing multiple fields, a separate fertilization map had to be prepared for each field, leading to an increased workload. In particular, when fertilizing a newly developed field that was previously abandoned farmland, it can be difficult to prepare a fertilization map due to the lack of past data and practice.

[0008] Furthermore, when fertilizing multiple fields, in fields where the difference in topsoil depth (i.e., the depth of the topsoil layer) is greater than usual, fertilization using a fertilization map is not always effective, and seedlings may grow too large in areas with deep topsoil, leading to lodging. Therefore, there is a need to flexibly change the method for determining the amount of fertilizer to be applied for each field.

[0009] Therefore, the present invention aims to solve these problems, reduce the workload of having to prepare a fertilization map for each of the multiple fields, and provide a work vehicle that enables fertilization work by flexibly changing the method for determining the amount of fertilizer to be applied for each field. [Means for solving the problem]

[0010] To achieve the above objective, the first invention is: A work vehicle comprising a fertilizer application device and a positioning device for acquiring its own position, wherein the fertilizer application amount of the fertilizer application device is controlled based on the target fertilizer application amount for the section corresponding to the vehicle's position acquired by the positioning device, using a fertilizer application map in which the fertilizer application amount is set for each section of the field, The system further comprises 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 is equipped with a fertility sensor, The system is configured to allow selection of at least one of the following modes: a fertilization map-based fertilization mode that determines the amount of fertilizer based on the fertilization map, and a soil information-based fertilization mode that determines the amount of fertilizer based on soil information acquired from the soil information acquisition unit. A soil information utilization fertilization map is created by calculating and mapping the amount of fertilizer determined by the soil information utilization fertilization mode for each section. The present invention provides a work vehicle characterized in that at least one of the fertilization map and the soil information utilization fertilization map can be displayed on the display unit.

[0011] According to the first invention described above, by configuring the system to allow selection and execution of a fertilization mode using a fertilization map and a fertilization mode using soil information, the workload of having to prepare a separate fertilization map for each of the multiple fields can be reduced. Furthermore, it becomes possible to flexibly change the method for determining the amount of fertilizer to be applied for each field, enabling fertilization work.

[0012] The second invention is, in the first invention described above, The control device is characterized in that, while the fertilization map-based fertilization mode is running, if the topsoil depth measured by the topsoil depth sensor exceeds a preset threshold, it automatically switches to the soil information-based fertilization mode.

[0013] According to the second invention described above, in addition to the effects of the first invention, the fertilization mode is automatically switched, and fertilization is performed using the soil information utilization fertilization mode. As a result, fertilization can be performed using a method that takes into account the topsoil depth, thus effectively preventing lodging caused by overgrowth of seedlings.

[0014] The third invention is, in the first or second invention described above, It is equipped with a field group information management unit that manages information about managed fields, The aforementioned field group information management unit comprises a field group information creation unit for creating field group information, a field group analysis information creation unit for creating field group analysis information, and a field group information storage unit for storing information about managed fields. The field group information is comprised of information from the soil information utilization fertilization map created for multiple fields, The aforementioned field group analysis information generation unit is configured to calculate evaluation information indicating the fertility of the fields based on the aforementioned field group information and include it in the aforementioned field group analysis information. The field group analysis information is configured to be displayed on the display unit.

[0015] According to the third invention described above, in addition to the effects of the first or second invention described above, it is possible to visually grasp the relative differences in fertility among multiple fields, which contributes to the examination and optimization of fertilization policies for the entire group of fields. [Effects of the Invention]

[0016] 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 the multiple fields, and enables fertilization work by flexibly changing the method for determining the amount of fertilizer to be applied for each field. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a left side view of a work vehicle according to an embodiment of the present invention. [Figure 2] Figure 2 is a schematic left side view of the fertilizer application device shown in Figure 1. [Figure 3]FIG. 3 is a schematic plan view of the mobile information terminal shown in FIG. 1 [Figure 4] FIG. 4 is a block diagram showing the configuration of the control system of the mobile information terminal shown in FIG. 3. [Figure 5] FIG. 5 is an explanatory diagram for explaining the information creation procedure of the fertilization map. [Figure 6] FIG. 6 is an explanatory diagram for explaining the data content of the soil information utilization fertilization map information. [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 for explaining the data content of the farm field group information and the farm field group analysis information. [Figure 9] FIG. 9 is a block diagram showing the configuration of the control system including the control device shown in FIG. 1. [Figure 10] FIG. 10 is an explanatory diagram for explaining the target travel route of the work vehicle. [Figure 11] FIG. 11 is a flowchart showing the flow of processing at the time of setting the basic fertilization amount. [Figure 12] FIG. 12 is a flowchart showing the flow of the fertilization mode automatic switching process.

MODE FOR CARRYING OUT THE INVENTION

[0018] [[ID=?]] Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings. [[ID=?]]

[0019] [[ID=?]] First, the basic configuration of the work vehicle 1 will be described below. [[ID=?]]

[0020] [[ID=?]] <Basic Configuration of Work Vehicle> FIG. 1 is a left side view of the work vehicle 1 according to a preferred embodiment of the present invention. [[ID=?]]

[0021] [[ID=?]] In this specification, as indicated by the arrow in FIG. 1, the side in the traveling direction of the work vehicle 1 is defined as the front. Unless otherwise specified, the left side in the traveling direction of the work vehicle 1 is referred to as "left", and the opposite side is referred to as "right". The work vehicle 1 is also simply referred to as the "airframe". It seems there are some tags with "?" in the original text which might be incorrect or incomplete. I've translated the text as accurately as possible based on the provided rules.

[0022] The work vehicle 1 according to this embodiment has the configuration of a rice transplanter, as an example. Specifically, as shown in Figure 1, its basic configuration includes a vehicle body 2 (hereinafter also simply referred to as "vehicle body") that travels on the field, and the vehicle body 2 is equipped with a seedling planting unit 3 for planting seedlings in the field, a fertilizer application device 4 for applying fertilizer to the field, a positioning device 5 for measuring the position of the machine, a soil information acquisition unit J for acquiring soil information of the field, and a control device C for controlling various mechanisms of the work vehicle 1. It is also equipped with a portable information terminal 6 (see Figures 3 and 5) for the operator to remotely operate the work vehicle 1.

[0023] <Structure of the running vehicle> The mobile body 2 is a mobile body that forms the main body of the work vehicle 1. This mobile body 2 comprises a main frame 2a that extends in the front-rear direction of the machine and forms the machine's frame, and a rear frame 2b that extends in the width direction and is attached to the rear end of the main frame 2a. A floor step 2c on which an operator can board is provided on the upper part of the main frame 2a, and a control unit 7 that controls operation and a cockpit 7g on which the operator sits are provided on this floor step 2c.

[0024] Furthermore, the engine E, which is the power source for the vehicle body 2, is located below the driver's seat 7g. The power output from the engine E is transmitted to the transmission case e3 via a belt-type power transmission mechanism e1 located below the floor step 2c, through a hydrostatic continuously variable transmission (HST) e2, as shown in Figure 1.

[0025] The hydrostatic continuously variable transmission e2 is a mechanism in which the opening of the trunnion shaft (not shown) is adjusted by the drive of the HST servo motor e4 (see Figure 2), thereby changing the output to the transmission case e3. This allows for adjustment of the vehicle speed.

[0026] The power transmitted to the transmission case e3 is shifted internally and then branched and transmitted to the pair of front wheels 9 and the pair of rear wheels 10 for driving, and to the seedling planting unit 3 for work. The driving power is transmitted to the pair of front wheels 9 via the front wheel final case e5 and the front wheel axle e6 (see Figure 1), and also to the pair of rear wheels 9 via the pair of rear wheel transmission shafts e7, the pair of rear wheel gear cases e8 and the rear wheel axle 82 shown in Figure 1. On the other hand, the work power is transmitted to a planting clutch (not shown) located at the rear of the vehicle body 2, and when the planting clutch is engaged by a predetermined operation, the power is further transmitted to the seedling planting unit 3.

[0027] The control unit 7 is equipped with various operating components for the operator to use. Specifically, it includes a main gear lever 7a for changing the forward / reverse movement and vehicle speed of the vehicle body 2, a steering wheel 7b for steering the pair of left and right front wheels 9, a straight-line assist lever 7c for starting or ending the straight-line control, which is one of the automatic driving functions, via the control device C, and a control panel 7d equipped with various operating switches. Furthermore, the control panel 7d is equipped with a monitor 7e capable of displaying various information. In addition to the steering wheel 7b, the control unit 7 is equipped with a steering mechanism for steering the work vehicle 1, including a steering shaft 7f, a pitman arm, and tie rods (not shown), and these mechanisms change the steering angle of the front wheels 9, which are the steering wheels, in accordance with the rotational operation of the steering wheel 7b. A driver's seat 7g is located behind the steering wheel 7b.

[0028] <Structure of the seedling planting section> The seedling planting unit 3 is attached to the rear of the vehicle body 2 via a lifting linkage device 11. The lifting linkage device 11 comprises an upper link arm 11a and a pair of lower link arms 11b on the left and right sides, and is configured to allow the seedling planting unit 3 to move up and down.

[0029] 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 upper and lower link arms 13 located below the seedling planting section 63.

[0030] Here, the control device C controls an electronic hydraulic valve (not shown), and when the lifting hydraulic cylinder 14 shown in Figure 1 is retracted hydraulically, the upper link arm 11a rotates upward and backward, causing the seedling planting unit 3 to rise to a non-working position. When the seedling planting unit 3 is in a non-working position, its lower end is at approximately the same height as the bottom of the main frame 2a.

[0031] In response, when the lifting hydraulic cylinder 14 is extended hydraulically, the upper link arm 11a rotates downward and backward, and the seedling planting unit 3 is lowered to a working position (the position shown in Figure 1) where seedling planting can be performed.

[0032] As shown in Figure 1, the seedling planting unit 3 includes a seedling stand 3a for propping up soil-covered mat-shaped seedlings (so-called seedling mats), a planting device 3b located behind and below the seedling stand 3a, a center float 3c located at the bottom of the seedling planting unit 3b, and side floats 3d positioned to the left and right of the center float 3c.

[0033] Multiple planting devices 3b are arranged in a line along the width of the work vehicle 1, and each planting device 3b is equipped with two pairs of planting tools 3e arranged in the front-to-back direction. When the planting clutch is engaged and the drive shaft 3f shown in Figure 1 is rotated, the front planting tool 3e and the rear planting tool 3e shown in Figure 1 rotate around the drive shaft 3f, alternately picking up seedlings located at the lower end of the seedling tray 3a and planting them in the field.

[0034] The center float 3c and side floats 3d are configured to glide and level the field as the work vehicle 1 moves, and seedlings are planted in the field leveled by each float 3c and 3d by each planting device 3b. In addition, the center float 3c and side floats 3d are configured to swing to conform to the unevenness of the field.

[0035] <Configuration of the fertilizer application device> Figure 2 is a schematic left side view of the fertilizer application device 4 shown in Figure 1.

[0036] The fertilizer application device 4 includes an air chamber 4a extending in the left-right direction of the machine, a blower 4b that pressurizes and sends air from left to right through the air chamber 4a, a fertilizer hopper 4c that stores fertilizer to be supplied to the field, a plurality of dispensing devices 4d located below the fertilizer hopper 27, a plurality of connecting pipes 4e located below each dispensing device 4d, the front end of which is connected to the air chamber 4a, and a plurality of fertilizer hoses 4f connected to the rear end of each connecting pipe 4e and extending to the lower part of the seedling planting section 3.

[0037] The blower 4b is equipped with an intake duct 4g, and when a blower motor (not shown) is driven, air is drawn in through the intake duct 4f and supplied into the air chamber 4a. The air supplied into the air chamber 4a is then pumped to the right and supplied to each fertilizer hose 4f through each connecting pipe 4e.

[0038] Each dispensing device 4d has an opening at the top to receive fertilizer supplied by dropping from the fertilizer hopper 4c, and inside it is a dispensing roll 4i having a dispensing groove 4h on its outer surface. As the dispensing shaft 4j, which is inserted through a hole (not shown) that penetrates each dispensing roll 4i in the left-right direction, rotates, the dispensing roll 4i rotates. As a result, the fertilizer in the dispensing groove 4h is dispensed downwards to the dispensing device 4d. The fertilizer dispensed by the dispensing 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 by passing through the fertilizer hose 6f with air supplied from the front air chamber 4a.

[0039] Here, the rotational speed of the fertilizer application rate adjustment motor 4m, which rotates the dispensing shaft 4j, is controlled by the control device C. That is, the amount of fertilizer dispensed by the dispensing device 4d is determined according to the rotational speed of the dispensing roll 4i, so the control device C can control the amount of fertilizer dispensed by the fertilizer application rate adjustment motor 4m. More specifically, the amount of fertilizer dispensed is the weight of fertilizer supplied per unit area of ​​the field, and is determined, for example, by the amount of fertilizer supplied in kilograms per 10 ares (1 acre). Therefore, the control device C controls the rotational speed of the dispensing roll 4i to be the target speed calculated based on the target amount of fertilizer dispensed, according to the target amount of fertilizer dispensed. The higher the target amount of fertilizer dispensed, the faster the rotational speed of the dispensing roll 4i is controlled, and the lower the target amount of fertilizer dispensed, the slower the rotational speed is controlled.

[0040] <Configuration of the positioning device> The positioning device 5 includes a GNSS receiver with a receiving antenna that receives radio waves from GNSS satellites, and an inertial measurement module that detects the tilt and acceleration of the three axes of the vehicle. This positioning device 5 is located at the front of the vehicle body 1, at the upper end of the frame material extending upward, and performs the function of acquiring the vehicle's 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. The position information measured by the positioning device 5 is transmitted to the control device C (see Figure 5).

[0041] <Configuration of the soil information acquisition unit> The soil information acquisition unit J acquires information indicating the soil's fertility (i.e., how easily crops can grow) by measuring the soil in the field (hereinafter referred to as soil information). The soil information acquisition unit J is equipped with a topsoil depth sensor j1 that measures the topsoil depth (i.e., the depth of the topsoil layer) and a soil fertility sensor j2 that measures the soil's fertility. The topsoil depth sensor j1 is an ultrasonic sensor installed at the front of the vehicle body 2, and it can measure the topsoil depth by measuring the depth to which the vehicle body sinks down to the hardpan. The soil fertility sensor j2 is installed on the front wheel 9, and it can measure the soil's fertility by passing a weak electric current through the soil and measuring the ions (nutrients) in the soil from its electrical conductivity (electrical resistance). More specifically, the SFV value (Soil Fertility Value) is measured as an indicator 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 (topsoil depth, SFV value) from the soil information acquisition unit J is linked to the location information (e.g., latitude, longitude) of the point measured by the positioning device 5 at predetermined time intervals and transmitted to the control device C.

[0042] <Configuration of a mobile information terminal> Figure 3 is a schematic plan view of the personal information terminal shown in Figure 1, and Figure 4 is a block diagram showing the configuration of the control system of the personal information terminal shown in Figure 3.

[0043] The portable information terminal 6 is an information processing device separate from the vehicle body 2, and is, for example, a smartphone or tablet, an information processing device that can be carried by an operator. Although not shown in the figure, this portable information terminal 6 is configured to include a CPU that performs calculations and memory that can read and write information necessary for calculations. The configuration shown as a functional block in Figure 4 is realized by the CPU operating according to various control programs stored in the memory.

[0044] As shown in Figures 3 and 4, the portable information terminal 6 comprises 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.

[0045] The display unit 6a has the function of outputting video and audio, and is composed of, for example, a liquid crystal panel with a speaker. The operation unit 6b is composed of multiple pressure-sensitive buttons, etc. The fertilization map 6c has the function of setting the fertilization map Dh, which will be described later, to the fertilization map storage unit 6c and the control device C. The data related to the fertilization map Dh may be configured to be acquired from an external server SV, or it may be configured to be able to generate data based on the operation of the operation unit 6b, and the data may be set by the operator's operation of the operation unit 6b related to setting the amount of fertilizer applied.

[0046] Furthermore, the fertilization map storage unit 6d is a memory equipped with a storage area, and is composed of RAM or the like, but may also be composed of a removable recording medium such as an SD card. The fertilization map storage unit 6c stores the data of the fertilization map Dh, which will be described later, in advance before the start of the operation.

[0047] The NDVI value acquisition unit 6e performs the function of acquiring the NDVI value (Normalized Vegetation Index) of the field to be worked on. The NDVI value is calculated for each point in the field based on infrared reflectance, etc., using satellite images of the field taken before harvest in the previous year, which show the field where seedlings will be planted. The satellite images of the field taken before harvest in the previous year, which show the field where seedlings will be planted, are acquired from an external server SV connected via a network NW. The NDVI value is represented as an integer value from 0 to 200, and the higher the value, the higher the estimated soil fertility. The information regarding the calculated field's NDVI value is linked to the data of the fertilization map Dh for each point in 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 regarding the field's NDVI value.

[0048] <Fertilization Map> The fertilization map creation unit 6d performs the function of creating information for the fertilization map Dh. Figure 5 is an explanatory diagram illustrating the procedure for creating information for the fertilization map. Referring to Figure 5, the procedure for creating the fertilization map Dh by the fertilization map creation unit 6d will be explained below.

[0049] First, the fertilization map creation unit 6d obtains information from the NDVI value acquisition unit 6e, specifically from the NDVI value map Dn. This NDVI value map Dn is data in which an NDVI value is set for each point P in the field, and consists of at least information indicating the field area, location information for each point in the field area, and information on the NDVI value set for each point in the field. Any point P within the roughly rectangular field area R, which indicates the field area, can be identified by its latitude and longitude and corresponding two-dimensional coordinates X and Y.

[0050] Next, a conversion NDVI value map Dn2 is created to convert the information in the NDVI value map Dn into the information in the fertilization map Dh. Here, the fertilization map Dh is data in which the target amount of fertilizer is set for each plot of the field, and consists of at least information indicating the area of ​​the field, location information for each point in the area of ​​the field, and information on the target amount of fertilizer set for each plot of the field.

[0051] In detail, as shown in Figure 5, the fertilization map Dh allows any point within the roughly rectangular field area R, which represents the field area, to be identified by its latitude and longitude and corresponding two-dimensional coordinates X and Y. This configuration allows for the identification of points within the field area R from the positional information indicating the latitude and longitude of the machine located within the field.

[0052] Furthermore, the field area R is divided into rectangular sections K2 of a predetermined size in a matrix. The fertilization map Dh is composed of information for each section K2, including a section number to identify the section, the two-dimensional coordinate range of the section (range X, range Y), and the target fertilization amount M and NDVI value set for that section K. The target fertilization amount M is the target amount of fertilizer (control amount) for the fertilization device 4, and is set, for example, in kilograms of fertilizer per 10 ares. With this data configuration, the control device C can, by referring to the fertilization map Dh, identify the section K2 to which any point in the field being worked belongs from the location information of that point, obtain the target fertilization amount M set for the identified section, and control the amount of fertilizer applied by the fertilization device 4 to match the obtained target fertilization amount M.

[0053] Therefore, the conversion NDVI value map Dn2 is configured to divide the field area R of the NDVI value map Dn into a matrix according to the fertilization map Dh, assign a plot number to each plot K, calculate the average value of the NDVI values ​​of the points included in that plot, and set the average NDVI value, which is the calculated average value.

[0054] Next, a fertilization map Dh is created for each plot K by converting the average NDVI value into a target fertilizer application amount M. Here, the target fertilizer application amount M for each plot K2 is determined by a predetermined calculation method based on the average NDVI value of each plot K2. The higher the average NDVI value, the more fertile the soil in that plot is estimated to be, so the target fertilizer application amount M is set lower. The target fertilizer application amount M for each plot K2 in the fertilization map Dh can be changed as needed by the operator using the portable information terminal 6. This makes it possible to set fertilizer application amounts that take into account soil fertility, etc., for each plot in the field. 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.

[0055] <Soil Information-Based Fertilization Map> The soil information utilization fertilization map creation unit 6e performs the function of creating the soil information utilization fertilization map Dj. Figure 6 is an explanatory diagram illustrating the data content of the information in the soil information utilization fertilization map Dj. As shown in Figure 6, the soil information utilization fertilization map Dj divides the field area R into rectangular sections K3 of a predetermined size in a matrix, corresponding to section K2 of the fertilization map Dh. That is, the size and range of sections K2 and K3 are designed to be the same. Then, a soil information utilization fertilization amount M2 is set for each section K3.

[0056] Here, the soil information-based fertilizer application amount M2 is set by calculating the average value for each field section from the fertilizer application amount calculated by the calculation method of the soil information-based fertilizer application mode described later. In other words, the soil information-based fertilizer map creation unit 6e acquires the fertilizer application amount calculated by the calculation method of the soil information-based fertilizer application mode from the control device C at predetermined time intervals, along with location information, determines which section K3 it belongs to from the machine's location information, aggregates the fertilizer application amount for each section K3, calculates the average value, and sets the calculated average value as the soil information-based fertilizer application amount M2 for each section K3, thereby enabling the creation of the soil information-based fertilizer map Dj. The created soil information-based fertilizer map Dj is stored in the field group information management unit 6f described later. Furthermore, the portable information terminal 6 is configured so that the operator can display and compare the fertilizer map Dh and the soil information-based fertilizer map Dj stored in the field group information management unit 6f on the display unit 6a by performing predetermined operations. This allows for the comparison of fertilizer application rates calculated using different methods, which can be used to analyze the most suitable fertilization method for each field.

[0057] The field group information management unit 6f performs the function of managing information about multiple fields that are the target of work (hereinafter also referred to as "managed fields"). A field group refers to multiple fields. The field group information management unit 6f comprises 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 managed fields.

[0058] Figure 7 is a schematic plan showing an example of a managed field, and Figure 8 is an explanatory diagram illustrating the data contents of the field group information and field group analysis information. The field group information DG created by the field group information creation unit 6g summarizes information about managed fields, and for each field, it summarizes information such as a topsoil depth map Ds, an NDVI value map Dn, a fertilization map Dh, a soil information utilization fertilization map Dj, a lodging location map Ds, basic fertilization amount, total fertilization amount, and total yield, which are mapped by summarizing the measured values ​​obtained by the topsoil depth sensor j1 along with location information. The lodging location map Dj is a map showing the lodging location of seedlings, and is created, for example, by image analysis of satellite images of the field before harvest in the previous year, which shows the field where seedlings will be planted. In the illustrated example, information on the three fields H1, H2, and H3 shown in Figure 7 is compiled into field group information DG shown in Figure 8.

[0059] 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 confirm it on the display unit 6a by performing a predetermined operation. This makes it possible to analyze fertilization methods suitable for each of multiple fields. The field group analysis information DA includes, for example, the average value of the NDVI value map Dn, which shows the average value of the NDVI value for the entire field; the average value of the fertilization map Dh, which shows the average value of the target fertilization amount M for the entire field; and fertilization rank (for example, a five-level evaluation of S, A, B, C, D) which shows the evaluation of the field's fertility based on the values ​​of the average value of the NDVI value map and the average value of the fertilization map.

[0060] The created field group information DG and field group analysis information DA are stored in the field group information storage unit 6i, and the system is configured so that the operator can display and confirm them on the display unit 6a by performing a predetermined operation. This makes it possible to analyze fertilization methods suitable for each of multiple fields. In addition, the field group analysis information DA is compiled for each field (fields H1, H2, and H3), but data combining multiple fields may also be created. For example, by creating data in which the values ​​of fields H1, H2, and H3 are added together or the average value is calculated and recorded, it can be used to analyze the entire field (fields H1, H2, and H3). The operator may also select fields from multiple fields to calculate the sum or average value (for example, fields H1 and H3) and have the data created accordingly. This makes it easier to analyze fields in different locations (for example, multiple fields belonging to region 1 and multiple fields belonging to region 2) even when there are multiple fields located far apart (for example, region 1 and region 2).

[0061] Furthermore, the portable information terminal 6, via the communication control unit 6f, can send and receive various information wirelessly with the work vehicle 1 and the external server SV via the network NW. The operation information from the operation unit 6b is transmitted to the control device C of the work vehicle 1, and the control device C performs various processes according to the acquired operation information. As a result, the worker can remotely give various instructions and make various settings such as starting work, starting to drive, moving forward and backward, and stopping, without having to board the work vehicle 1, by operating the portable information terminal 6.

[0062] <Control device configuration> Figure 9 is a block diagram showing the configuration of the control system including the control device C of the work vehicle 1.

[0063] Control device C is an information processing device composed of multiple ECUs (Electronic Control Units). Each of these ECUs is equipped with a CPU for performing calculations and memory capable of reading and writing information necessary for those calculations. The CPU operates according to various control programs stored in the memory, thereby realizing the configuration shown as a functional block in Figure 2.

[0064] As shown in Figure 5, the control device C includes 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 application amount setting unit c7, and a fertilizer application device control unit c8, which are configured to send and receive information from each other via a communication bus BA.

[0065] The output processing unit c1 functions as an input / output interface and is connected to the driving system equipment group M1, which controls driving functions such as driving, stopping, and changing the direction of driving of the work vehicle 1; the work system equipment group M2, which controls work functions such as fertilizing and planting; and the monitor 7e, which outputs video and audio. For example, in this embodiment, the driving system equipment group M1 includes mechanisms such as a steering actuator, engine E, transmission, and brakes, and the work system equipment group M2 includes mechanisms such as a PTO clutch, PTO transmission, braking system, and lifting hydraulic cylinder 14.

[0066] 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 portable information terminal 6, enabling the sending and receiving of various types of information.

[0067] The input processing unit c3 is a mechanism that receives information input from connected external devices and is capable of acquiring various types of information such as positioning information and detection information. In this embodiment, the input processing unit c3 is connected to a positioning device 5, a driving system detection sensor S1 including a steering angle detection means, various sensors that detect the operating status of the seedling planting unit 3 and the fertilizer application device 4, and a work system detection sensor S2 including a soil information acquisition unit J.

[0068] Furthermore, the control device C includes a travel control unit c4 that controls the movement 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.

[0069] The driving control unit c4 is a mechanism that includes a program and various circuits for controlling the movement of the work vehicle 1 during automatic driving (automatic steering) and manual driving (manual steering), and includes 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.

[0070] The automatic driving control device c41 includes a vehicle position calculation unit c411 that calculates the vehicle's position in the field by acquiring positioning information (location information) from the positioning device 5, a vehicle direction calculation unit c412 that calculates the vehicle's direction, a deviation calculation unit c413 that calculates the deviation, and a steering angle calculation unit c414 that calculates the steering angle from the detection information of the driving system detection sensor group S1. With the automatic driving control device c41 configured in this way, the deviation calculation unit c413 calculates the deviation, and based on the calculated deviation, it calculates the appropriate steering angle of the steering wheel 7b for the work vehicle 1 to travel along the target driving path L, and controls the steering actuator to achieve the calculated steering angle, thereby enabling the work vehicle 1 to travel automatically along the target driving path L.

[0071] The information storage unit c5 is a storage device capable of storing various types of information, and is composed of, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The information storage unit c5 includes a field information storage unit c51 for storing field information (hereinafter referred to as "field information"), a route information storage unit c52 for storing route information of the work vehicle 1 (hereinafter referred to as "route information"), and a work information storage unit c53 for storing setting information related to work (hereinafter referred to as "field information"). The information stored in the information storage unit c5 can be acquired by the portable information terminal 6 via the network NW, and the acquired information can be displayed on the display unit 6a for the worker. This allows the worker to analyze the field and the work.

[0072] The field information storage unit c51 is a memory area for storing field information. Here, the field information includes, for example, information such as the size, shape, and location of the field being worked on, and the location data of the ridges that define the boundaries of the field.

[0073] The route information storage unit c52 is a memory area for storing route information. Here, the route information includes, for example, position information indicating the target travel route L described later, and other information related to the travel route of the work vehicle 1.

[0074] The work information storage unit c53 is a memory area for storing work information. Here, the work information includes, for example, setting information related to the work of the work vehicle 1, such as the work width W and the type of work (fertilization, planting, etc.) that are set in advance by the worker.

[0075] 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.

[0076] The route calculation unit c61 calculates the target travel route L based on field information and work information, etc.

[0077] Figure 10 is an explanatory diagram illustrating the target travel path of the work vehicle 1. Here, the target travel path L refers to the travel path that the work vehicle 1 aims for during automated driving, and the information indicating the target travel path L consists of positional information that shows the trajectory of the target travel path L. The route calculation unit c61 calculates the target travel path L using, for example, the following design procedure.

[0078] First, field information is acquired, and the field area R is divided into a headland area R1 where work is performed by traveling in a circular motion, and a straight-line area R2 where work is performed by traveling in a straight line. Here, the headland area R1 is set as a frame-shaped area with a working width W, and the rectangular straight-line area R2 is set inside the headland area R1. The field area R is an area that represents a field, and the shape and size of the area are designed to correspond to the shape and size of the field.

[0079] Next, a headland travel path l1 is designed that travels in a circular manner within the headland travel area R1 (work paths VI to IX). Subsequently, multiple straight travel paths l2 are designed that travel in a straight line within the straight travel area R2 (work paths I to V). Here, to prevent work from being performed on multiple straight travel paths l2 at the same point, a distance approximately equal to the work width W is provided between them.

[0080] Next, a non-working path l3 is designed, which is a path where no work is performed, for moving between straight-line travel paths l2 in a single continuous line, as well as for turning between straight-line travel paths l2 and moving from straight-line travel path l2 to headland travel path l1. The information indicating the target travel path L calculated in this manner is stored in the path information storage unit c52.

[0081] 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 routes (work routes I to IX in the illustrated example), which are the routes for performing the tasks included in the target travel route L. This travel order is set based on predetermined rules, but the operator can also change it to any travel order by operating the portable information terminal 6 or the control panel 7d. This travel order setting information, along with the information indicating the target travel route L, is stored in the route information storage unit c52.

[0082] For example, in the example shown in Figure 10, the travel order is set as follows: 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 direction of the arrows for the headland travel path l1 and straight travel path l2 shown in the figure indicates the direction of travel of the work vehicle 1, but it is not necessarily limited to this direction depending on the travel order. When the automatic travel of the work vehicle 1 begins, 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 driven automatically based on the position information of the work start point Ps. Furthermore, when the work vehicle 1 reaches the work end point PE of the straight travel path l2 in Figure 6, it is configured to travel 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 travel in the opposite direction, from the headland travel path l1 to the straight travel path l2.

[0083] The stop position setting unit c63 sets the position where the work vehicle 1 will temporarily stop during automatic driving along the target driving path L. These stop positions are set based on predetermined rules, but the operator can also change the set stop positions by operating the portable information terminal 6 or the control panel 7d. Information regarding the set stop positions is stored in the route information storage unit c52. When the work vehicle 1 reaches a stop position during automatic driving, it temporarily stops the automatic driving. After the temporary stop, the system is configured to resume automatic driving by instructing the operator to resume driving through a predetermined operation on the portable information terminal 6. This allows the operator to check the remaining amount of fuel, fertilizer, seedlings, etc. in the work vehicle 1 at the stop position and replenish materials if necessary.

[0084] The stopping position can be set at the end of work paths I to IX. In the illustrated example, it is set at the end positions Pm1 and Pm2 of work paths II and IV on one end of the field (i.e., the side easily visible to the worker). Alternatively, it may be set at the end positions of work paths I, III, and V on the other end of the field.

[0085] Furthermore, the stop position setting unit c63 is configured to skip (continue automatic driving without stopping) a set stop position when a predetermined operation is performed on the portable information terminal 6 while the work vehicle 1 is automatically driving. The number of skips can be accumulated and reserved before reaching a stop position, and the number of skips is stored in the work information storage unit c53 each time. For example, pressing the "F" button and the "Right" and "OK" buttons on the operation unit 6b simultaneously can increase the number of stop position skips by one. Furthermore, pressing the "F" button and the "Left" and "Back" buttons on the operation unit 6b simultaneously can decrease the number of stop position skips by one. This allows for flexible adjustment of the number of stops for material replenishment, for example, depending on the size of the field.

[0086] The fertilizer application amount setting unit c7 is a program that performs the function of setting the fertilizer application amount, and includes a basic fertilizer application amount setting unit c71 and a soil information learning unit c72.

[0087] The basic fertilizer application rate setting unit c71 is a program that performs the function of setting the basic fertilizer application rate. This basic fertilizer application rate can be set by operating the portable information terminal 6 or the control panel 7d, and the set value of the basic fertilizer application rate is stored in the work information storage unit c53 and referred to when necessary during fertilization work. Here, the basic fertilizer application rate is the basic amount of fertilizer to be applied to the field being worked on, or in other words, the basic value of the amount of fertilizer to be set for each field. The basic fertilizer application rate is set, for example, in kilograms of fertilizer per 10 ares (ares).

[0088] <Setting the basic fertilizer application rate> Figure 11 is a flowchart showing the processing flow when setting the basic fertilizer application rate.

[0089] The basic fertilizer application rate setting unit c71 allows for the setting of basic fertilizer application rates for multiple fields (managed fields) at once, following the procedure described below.

[0090] As shown in Figure 1, first, a field to be set (standard field) is selected from the managed fields (Step #1). Once a standard field is selected (for example, field H1 in Figure 7), a reference fertilizer application amount, which is used as a reference when setting the basic fertilizer application amount, is displayed on the display unit 6e or monitor 7e (Step #2). The reference fertilizer application amount is, for example, the average value of the fertilizer map included in the field group analysis information DA of the field selected as the standard field (for example, in the case of Figure 8, 35 kg / 10a).

[0091] Next, when the operator inputs the basic fertilizer application rate for a standard field, this is set in the field information storage unit c51. Based on the information regarding the input and set basic fertilizer application rate, the data content of the basic fertilizer application rate item in the field group information DG of the field group information storage unit 6i is also updated (step #3).

[0092] Next, based on the standard fertilizer application rate set in the input settings for the standard field, candidate basic fertilizer application rates for fields other than the standard field (for example, fields H1 and H2 in Figure 7) are calculated (Step #4). The candidate basic fertilizer application rates calculated at this time are calculated, for example, by comparing the average values ​​of the NDVI value map of the field group analysis information DA. In the example in Figure 8, the basic fertilizer application rate for standard field H1 is entered as 40, the average value of the NDVI value map for field H1 is 120, and for field H2 it is 100, so the candidate basic fertilizer application rate for field H2 is calculated as 40 × 120 / 100 = 48. Note that the calculation method is not limited to this. Candidate basic fertilizer application rates for field H3 are calculated in a similar manner.

[0093] Next, the basic fertilizer application rate setting unit c71 determines whether the calculated candidate basic fertilizer application rate is within the range of the set upper limit and set lower limit (step #5). These set upper and lower limits are set by the operator to their desired values; for example, the set upper limit may be set to 80 kg / 10a and the set lower limit to 30 kg / 10a.

[0094] The basic fertilizer application rate setting unit c71, if it determines that the calculated candidate basic fertilizer application rate is outside the range between the set upper and lower limits (N in step #5), corrects the candidate so that it falls within the range between the set upper and lower limits (step #6). For example, if the candidate basic fertilizer application rate exceeds the set upper limit of 80, it is corrected to 80, and if it falls below the set lower limit 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 check it. This prevents the setting of a basic fertilizer application rate value that deviates from the appropriate range.

[0095] Finally, the basic fertilizer application rate setting unit c71 sets the calculated candidate basic fertilizer application rate (when Y is selected in step #5) or the modified candidate basic fertilizer application rate (when N is selected in step #5) as the basic fertilizer application rate for each field other than the standard field (fields H2 and H3) in the information storage unit c51. It also updates the data content of the basic fertilizer application rate item in the field group information DG of the field group information storage unit 6i based on the information regarding the set basic fertilizer application rates (step #3). With this configuration, when managing multiple fields, the effort of setting a basic fertilizer application rate for each field is eliminated, reducing the workload on the operator and improving convenience, while also enabling the setting of an appropriate basic fertilizer application rate.

[0096] <Learning (Teaching) Soil Information> The soil information learning unit c72 is a program that performs 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 (topsoil depth, SFV value) acquired from the soil information acquisition unit J during learning in the work information storage unit c53. Furthermore, whenever soil information (topsoil depth, SFV value) is acquired, it calculates a growth evaluation value W using the topsoil depth and SFV value and stores it in the work information storage unit c53. Here, the growth evaluation value W indicates an evaluation value of how easily seedlings can grow in the soil, and a larger value indicates easier growth.

[0097] The growth evaluation value W can be calculated, for example, by the following formula (1).

[0098] (Equation 1) W = α × SFV value + β × topsoil depth α and β are weighting coefficients. As a result, the growth evaluation value W becomes larger as the SFV value increases and as the topsoil depth increases.

[0099] The soil information learning unit c72 begins learning soil information when the pre-set start conditions are met, and ends learning soil information when the pre-set end conditions are met. The start and end conditions for learning soil information are pre-set and stored in the work information storage unit c53, but the operator can change these settings by operating the portable information terminal 6 or the control panel 7d.

[0100] The conditions for starting soil information learning can be, for example, when automatic driving begins. Alternatively, it can be when the vehicle reaches the start of one of the work routes I to IX (which can be selected and set by the operator) on the target driving route L (see Figure 6). Alternatively, it can be when the vehicle reaches the start of one of the pre-set work routes I to IX on the target driving route L.

[0101] The completion condition for learning soil information can be, for example, when the automated driving is completed (driving stops). Alternatively, it can be when the system reaches the end of one of the work routes I to IX (which can be selected and set by the operator) on the target driving route L. Alternatively, it can be when the system reaches the end of one of the pre-set work routes I to IX on the target driving route L.

[0102] Preferably, the system is configured to start and end learning soil information when the start of the third step (work path III) of the straight-line travel path l2 is reached after the start of work by automated driving, and to end when 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, it may be the first or fourth step, and the operator can select and set any step. This is because learning soil information in one work step within the straight-line travel area R2 allows for more accurate learning of soil information for the entire field. Conversely, if soil information is learned near the edge of the field, the measured values ​​of the soil information may be biased due to the presence of, for example, a waterway next to the field, and may not necessarily reflect the entire field.

[0103] Furthermore, the soil information learning unit c72 is configured to allow the operator to start or stop learning soil information at their desired timing by performing a predetermined operation (for example, pressing a button) on the portable information terminal 6 or the control panel 7d, regardless of the above conditions. This improves convenience by allowing the operator to learn soil information at their desired location and timing.

[0104] When the soil information learning unit c72 has finished learning the soil information, it calculates the average values ​​of the topsoil depth, SFV value, and growth evaluation value W during the learning process and stores them in the work information storage unit c53. At this time, the average value of the growth evaluation value W calculated and stored in the work information storage unit c53 will be referred to as the growth evaluation value W based on the learning results in the following explanation.

[0105] The fertilizer application device control unit c8 comprises a fertilizer application amount control unit c81, a fertilizer application mode execution unit c82, and a fertilizer application mode management unit c83.

[0106] The fertilizer application control unit c81 is a program that transmits control signals to the fertilizer application device 4 to control the amount of fertilizer applied, thereby performing the function of controlling the amount of fertilizer applied by the fertilizer application device 4.

[0107] The fertilization mode execution unit c82 is a program capable of executing multiple fertilization modes with different methods for determining the amount of fertilizer to be applied. By passing information on the amount of fertilizer applied (control amount) of the fertilizer application device 4 to the fertilizer application amount control unit c81, it performs the function of determining the amount of fertilizer applied by the fertilizer application device 4 during fertilization work.

[0108] The fertilization mode execution unit c82 includes the following executable fertilization modes (programs): basic fertilizer amount fertilization mode c821, fertilization map utilization fertilization mode c822, soil information utilization fertilization mode c823, and hybrid fertilization mode c824.

[0109] <Basic fertilizer application rate and fertilizer application mode> The basic fertilizer application mode c821 is a mode in which a preset basic fertilizer application amount is determined as the fertilizer application amount of the fertilizer application device 4. That is, while the basic fertilizer application mode c821 is running (i.e., while the basic fertilizer application mode is selected), the fertilizer application amount of the fertilizer application device 4 is controlled to be the basic fertilizer application amount, and therefore remains constant under normal circumstances. The basic fertilizer application amount is determined by appropriately referring to the value set in the work information storage unit c53. If the value set in the work information storage unit c53 is changed, the fertilizer application amount of the fertilizer application device 4 is also changed.

[0110] <Fertilization map-based fertilization mode> The fertilization map-based fertilization mode c822 is a mode in which the amount of fertilizer applied by the fertilizer applicator 4 is determined based on the information in the fertilization map Dh. In other words, while the basic fertilization mode c821 is running (i.e., while the fertilization map-based fertilization mode is selected), the amount of fertilizer applied by the fertilizer applicator 4 is determined by the following procedure.

[0111] This fertilization map-based fertilization mode c822 acquires the position information (latitude and longitude) of the unit from the positioning device 5 at predetermined time intervals. Each time, it 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, it acquires information on the target fertilization amount M set for the identified section K, and determines the acquired fertilization amount as the fertilization amount for the fertilization device 4.

[0112] <Soil information-based fertilization mode> Soil information utilization fertilization mode c823 is a mode in which the amount of fertilizer applied by the fertilizer application device 4 is determined based on soil information. That is, while soil information utilization fertilization mode c821 is running (i.e., while soil information utilization fertilization mode is selected), the amount of fertilizer applied by the fertilizer application device 4 is determined by the following procedure.

[0113] The soil information utilization fertilization mode c823 acquires soil information from the soil information acquisition unit J at predetermined time intervals and calculates the growth evaluation value W using the above formula (1). Next, the calculated growth evaluation value W is compared with the growth evaluation value W based on the learning results stored in the work information storage unit c53, and the amount of fertilizer applied by the fertilizer application device 4 is determined based on the magnitude of the two values. The amount of fertilizer applied by the soil information utilization fertilization mode c823 can be calculated, for example, by the following formula (2).

[0114] (Formula 2) Fertilization amount = Basic fertilizer amount × (100-fertilization reduction rate (%)) / 100 However, when the growth evaluation value W > the growth evaluation value W obtained from learning, the fertilizer reduction rate (%) = 20 × the calculated growth evaluation value W / the growth evaluation value W obtained from learning, and when the growth evaluation value W < the growth evaluation value W obtained from learning, the fertilizer reduction rate (%) = 0.

[0115] In other words, the higher the calculated growth evaluation value W is compared to the growth evaluation value W obtained from the learning results, the more fertile the location where the soil information was obtained is presumed to be compared to the average fertility of the entire field. Therefore, the fertilizer reduction rate (%) is increased, and the amount of fertilizer applied is reduced accordingly. Conversely, if the calculated growth evaluation value W is lower than the growth evaluation value W obtained from the learning results, the less fertile the location where the soil information was obtained is presumed to be compared to the average fertility of the entire field. Therefore, the fertilizer reduction rate (%) is set to 0, and the base amount of fertilizer is determined as the amount of fertilizer applied without reduction. With the soil information utilization fertilization mode c824 configured in this way, it is possible to increase or decrease the amount of fertilizer applied, i.e., variable rate fertilization, while reflecting soil information measured in real time.

[0116] In addition, in the soil information utilization fertilization mode c824, immediately after the start of work, if the soil information learning unit c72 has not yet learned the 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 (%) will be set to 0 and the basic fertilizer amount will be determined as the fertilizer amount of the fertilizer application device 4 until the soil information learning unit c72 has completed learning the soil information.

[0117] Furthermore, even when the soil information utilization fertilization mode c824 is not running, the control device C is configured to calculate the amount of fertilizer applied using the method described above in the soil information utilization fertilization mode c823 at predetermined time intervals and to transmit the calculated amount of fertilizer applied along with location information to the mobile information terminal 6. As a result, the mobile information terminal 6 is able to create the soil information utilization fertilization map Dj.

[0118] <Hybrid fertilization mode> Hybrid fertilization mode c824 is a mode in which the amount of fertilizer applied by the fertilizer application device 4 is determined using information from the fertilization map and soil information. More specifically, while hybrid fertilization mode c824 is running (i.e., while hybrid fertilization mode is selected), the amount of fertilizer applied is determined by combining the amount of fertilizer determined by the fertilization map-based fertilization mode c822 and the amount of fertilizer determined by the soil information-based fertilization mode c824.

[0119] 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), then the amount of fertilizer determined by the hybrid fertilization mode c824 can be calculated, for example, by the following formula (3).

[0120] (Formula 3) Fertilization amount = (γ1×M1+γ2×M2) / 2 However, γ1 and γ2 are weighting coefficients that can be arbitrarily set by the operator, and γ1 + γ2 = 1. When setting the weighting coefficients, increasing the value of γ1 will give more weight to the amount of fertilizer M1 determined by the fertilization map-based fertilization mode c822, and increasing the value of γ2 will give more weight to the amount of fertilizer M2 determined by the soil information-based fertilization mode c823. This enables fine-grained variable fertilization according to the operator's needs. In addition, the quality of fertilization can be improved through multifaceted evaluation of the field.

[0121] The fertilization mode management unit c83 performs the function of managing the fertilization mode executed by the control device C, and includes a fertilization mode selection switching unit c831 and an automatic fertilization mode switching unit c832.

[0122] 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 fertilization mode execution unit c82 through a predetermined operation. For example, it displays a list of selectable fertilization modes on the display unit 6a or monitor 7e of the portable information terminal 6, and allows the operator to select the desired fertilization mode by operating the operation unit 6b or control panel 7d, and then causes the fertilization mode execution unit c82 to execute the selected fertilization mode.

[0123] <Automatic fertilization mode switching process> The fertilization mode automatic switching unit c832 is a program that performs the function of automatically switching the fertilization mode (hereinafter referred to as the fertilization mode automatic switching function), and the fertilization mode automatic switching function can be turned on or off as appropriate by the operator's prescribed operation. When the fertilization mode automatic switching function is turned on, the fertilization mode automatic switching unit c832 performs the following fertilization mode automatic switching process.

[0124] Figure 12 is a flowchart showing the flow of the automatic fertilization mode switching process.

[0125] When the automatic fertilization mode switching unit c832 starts the automatic fertilization mode switching process, it executes the fertilization map-based fertilization mode c822 (step #11). As a result, fertilization is performed using the fertilization map-based fertilization mode.

[0126] Next, the soil information acquisition unit J (topsoil depth sensor j1) determines whether the topsoil depth is greater than or equal to the set depth (step #12). If it is determined that the topsoil depth is greater than or equal to the set depth, the soil information utilization fertilization mode c823 is executed (step #13). The set depth is predetermined by the operator. As a result, in locations with deep topsoil, the fertilization mode is automatically switched, and fertilization is performed using the soil information utilization fertilization mode. Consequently, in locations with deep topsoil, fertilization can be performed using a method that takes the topsoil depth into account, thus effectively preventing lodging caused by overgrowth of seedlings due to deep topsoil. Subsequently, when the topsoil depth falls below the set depth, the system returns to the fertilization map utilization fertilization mode (step #12, N). Furthermore, if the automatic fertilization mode switching unit c832 determines that soil information cannot be acquired (Y in step #14), that is, that the control device C has not been able to acquire soil information from the soil information acquisition unit J and that some kind of malfunction has occurred, it executes the basic fertilization rate mode c821 (step #15). As a result, the fertilization mode is automatically switched and fertilization is performed using the basic fertilization rate mode. Consequently, even if some kind of malfunction occurs in the soil information acquisition unit J and a problem occurs in the progress of fertilization using the soil information utilization mode, the fertilization work can be continued smoothly, and a decrease in work efficiency can be effectively prevented.

[0127] After that, the system returns to step #14, and if it is determined that soil information can be acquired without any problems (N in step #14), it returns to the soil information utilization fertilization mode (step #13).

[0128] The embodiments of the present invention have been described above. The present invention is not limited to the embodiments described above. It goes without saying that modifications can be made as appropriate within the scope of the technical idea. For example, the basic fertilizer amount in the soil information utilization fertilization mode may be determined using the average value of the fertilization map of the field being worked on (see Figure 8). Fields often differ in soil type and other characteristics from region to region, and by determining the basic fertilizer amount while taking into account the characteristics of each region and adding information obtained from external sources (satellites), etc., an appropriate basic fertilizer amount can be set for each region.

[0129] The basic fertilizer application rate setting unit c71 may be configured to set the basic fertilizer application rate for a standard field by referencing the basic fertilizer application rate set for the field closest to that standard field. For example, in the example shown in Figure 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 application rate is set for the closer field H2, this can be set as the basic fertilizer application rate for field H1 of the standard field. This improves convenience.

[0130] <Other> The following configurations can also be added.

[0131] In this robotic rice transplanter, a specific remote control operation after ridging will initiate a transition to herbicide replenishment mode. The herbicide replenishment process can be performed using the following procedure, improving convenience compared to conventional methods. (1) After the ridges are closed, the system switches to herbicide replenishment mode through a specific operation (such as selecting from the remote control menu screen). (2) The turning starts and then automatically stops at the appropriate time. (3) Adjust the position of the rice transplanter by moving it forward and backward using the remote control, and lower the planting unit with the OK button. (4) Once the herbicide replenishment is complete, press the F + Start button to resume automatic driving.

[0132] When the robot transitions to herbicide replenishment mode, it starts turning and automatically pauses at the point "after the planting unit begins to lower but before planting begins." After pausing, pressing and holding the back button cancels the herbicide replenishment mode. Alternatively, after the planting unit lowering operation is performed, pressing and holding the F button + start button resumes automatic operation. Until then, the system does not accept the automatic operation restart operation (F button + start button). [Explanation of Symbols]

[0133] 1. Work vehicles 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 floats 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 feed roll 4j feeding shaft 4m Fertilizer application rate adjustment motor 5. Positioning device 6. Mobile Information Terminals 7. Control Unit 7a Main shift lever 7b Steering wheel 7c Straight-line assist lever 7d control panel 7e Monitor 7f Steering shaft 7g cockpit 9 Front wheels 10 Rear wheels 11. Lifting linkage 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 application device and a positioning device for acquiring its own position, wherein the fertilizer application amount of the fertilizer application device is controlled based on the target fertilizer application amount for the section corresponding to the vehicle's position acquired by the positioning device, using a fertilizer application map in which the fertilizer application amount is set for each section of the field, The system further comprises 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 is equipped with a fertility sensor, The system is configured to allow selection of at least one of the following modes: a fertilization map-based fertilization mode that determines the amount of fertilizer based on the fertilization map, and a soil information-based fertilization mode that determines the amount of fertilizer based on soil information acquired from the soil information acquisition unit. A soil information utilization fertilization map is created by calculating and mapping the amount of fertilizer determined by the soil information utilization fertilization mode for each section. A work vehicle characterized in that at least one of the fertilization map and the soil information utilization fertilization map can be displayed on the display unit.

2. The work vehicle according to claim 1, characterized in that the control device automatically switches to the soil information utilization fertilization mode when the topsoil depth measured by the topsoil depth sensor exceeds a preset threshold while the fertilization map utilization fertilization mode is being executed.

3. It is equipped with a field group information management unit that manages information about managed fields, The aforementioned field group information management unit comprises a field group information creation unit for creating field group information, a field group analysis information creation unit for creating field group analysis information, and a field group information storage unit for storing information about managed fields. The field group information is comprised of information from the soil information utilization fertilization map created for multiple fields, The aforementioned field group analysis information generation unit is configured to calculate evaluation information indicating the fertility of the fields based on the aforementioned field group information and include it in the aforementioned field group analysis information. The work vehicle according to claim 1 or 2, characterized in that the field group analysis information is configured to be displayed on the display unit.

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