Work vehicle

Abstract

To provide a work vehicle that can continue the work while automatically adjusting a fertilization amount even when position information of the own machine cannot be acquired during the work travel.SOLUTION: A work vehicle 1 comprises a fertilization device 4 and a positioning device 5 for acquiring the own machine position, and is configured to use a fertilization map where a fertilization amount is set for each section of a farm field on the basis of the own machine position acquired by the positioning device 5, acquire the target fertilization amount set to the section to which the own machine position belongs, and control the fertilization amount of the fertilization device. The work vehicle further comprises: a soil information acquisition unit J which acquires soil information of the farm field; and a control device C which controls the fertilization amount of the fertilization device 4. The work vehicle is configured to be able to selectively execute: a fertilization map-based fertilization mode which determines the fertilization amount of the fertilization device 4 on the basis of the information on the fertilization map; and a soil information-based fertilization mode which determines the fertilization amount of the fertilization device 4 through comparison between soil information acquired from the soil information acquisition unit J and soil information learned by a soil information learning unit.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 the information of this fertilization plan map, a conventional work vehicle acquires the position information of its own vehicle at predetermined time intervals during work driving, thereby identifying the section of the field where the vehicle is working, and automatically controlling the fertilizer application device so that the amount of fertilizer applied reaches the target amount associated with the identified section. As a result, the conventional work vehicle can automatically adjust the amount of fertilizer applied for each section of the field while automatically driving through the field.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, when a conventional work vehicle cannot obtain its own position information during work driving due to poor reception of a positioning satellite system such as GPS, it cannot identify the section of the field where the vehicle is located, so it cannot automatically adjust the amount of fertilizer applied. As a result, the work may be interrupted, and there is a risk of a significant decrease in work efficiency.

[0008] Therefore, an object of the present invention is to solve such problems and provide a work vehicle that can continue working while automatically adjusting the amount of fertilizer applied even when its own position information cannot be obtained during work driving.

Means for Solving the Problems

[0009] To achieve the above object, a first invention is An agricultural vehicle comprising a fertilizer application device and a positioning device for acquiring the position of the vehicle itself, and configured to control the fertilizer application amount of the fertilizer application device by obtaining the target fertilizer application amount set for the section to which the vehicle position belongs using a fertilizer application map in which the fertilizer application amount is set for each section of the farm field based on the vehicle position acquired by the positioning device. The agricultural vehicle further comprises a soil information acquisition unit for acquiring soil information of the farm field and a control device for controlling the fertilizer application amount of the fertilizer application device. The soil information acquisition unit includes a tillage depth sensor for measuring the tillage depth of the soil and a fertility sensor for measuring the fertility of the soil. The control device includes a soil information learning unit for learning the acquired soil information. The agricultural vehicle is configured to be able to acquire the soil information from the soil information acquisition unit, and Based on the information of the fertilizer application map, a fertilizer application map utilization fertilization mode for determining the fertilizer application amount of the fertilizer application device and a soil information utilization fertilization mode for determining the fertilizer application amount of the fertilizer application device by comparing the soil information acquired from the soil information acquisition unit with the soil information learned by the soil information learning unit are selectable and executable. An agricultural vehicle is provided.

[0010] According to the first invention, even when the position information of the vehicle itself cannot be acquired, the fertilizer application amount can be automatically adjusted by selecting and executing the soil information utilization fertilization mode, and as a result, a decrease in work efficiency can be prevented.

[0011] A second invention is the first invention, wherein When the control device determines that the positioning device has poor reception during the fertilizer application map utilization fertilization mode, the control device is configured to automatically switch from the fertilizer application map utilization fertilization mode to the soil information utilization fertilization mode.

[0012] According to the second invention, in addition to the effect of the first invention, even when poor reception of the positioning device occurs and a problem occurs in fertilization by the fertilizer application map utilization fertilization mode, the fertilization work can be continued smoothly, and a decrease in work efficiency can be prevented.

[0013] The third invention is, in the second invention described above, further, after the control device automatically switches from the fertilization map - based fertilization mode to the soil - information - based fertilization mode, when it determines that the reception failure of the positioning device has been resolved, it is configured to automatically switch from the soil - information - based fertilization mode to the fertilization map - based fertilization mode.

[0014] According to the third invention described above, in addition to the effects of the second invention, when the reception failure of the positioning device is resolved, it can quickly return to the fertilization map - based fertilization mode, so the convenience can be improved.

[0015] The fourth invention is, in the first invention described above, further provided with a portable information terminal for storing the information of the fertilization map, the control device is configured to be able to acquire the information of the fertilization map from the portable information terminal through communication, and when it determines that communication between the control device and the portable information terminal has become impossible during the fertilization map - based fertilization mode, it is configured to automatically switch from the fertilization map - based fertilization mode to the soil - information - based fertilization mode.

[0016] According to the fourth invention described above, in addition to the effects of the first invention, when it determines that communication between the control device and the portable information terminal has become impossible, by automatically switching from the fertilization map - based fertilization mode to the soil - information - based fertilization mode, the fertilization operation can be continued smoothly, and a decrease in work efficiency can be prevented.

[0017] The fifth invention is, in the fourth invention described above, further, after the control device automatically switches from the fertilization map - based fertilization mode to the soil - information - based fertilization mode, when it determines that communication between the control device and the portable information terminal has become possible, it is configured to automatically switch from the soil - information - based fertilization mode to the fertilization map - based fertilization mode.

[0018] According to the fifth invention described above, in addition to the effects of the fourth invention, When the communication failure between the control device and the portable information terminal is resolved, it can quickly return to the fertilization mode using the fertilization map, thus improving convenience.

[0019] The sixth invention is the invention according to the fourth or fifth invention, The control device is further configured to be able to execute a basic fertilization amount fertilization mode in which a preset basic fertilization amount is determined as the fertilization amount of the fertilization device. When it is determined that soil information cannot be obtained from the soil information acquisition unit during the fertilization mode using soil information, it is automatically configured to switch from the fertilization mode using soil information to the basic fertilization amount fertilization mode.

[0020] According to the sixth invention, in addition to the effects of the fourth or fifth invention, when it is determined that soil information cannot be obtained from the soil information acquisition unit, by automatically switching from the fertilization mode using soil information to the basic fertilization amount fertilization mode, the fertilization operation can be continued smoothly, and a decrease in work efficiency can be prevented.

[0021] The seventh invention is the invention according to any one of the first or sixth inventions, The control device is configured to be able to select and execute a hybrid fertilization mode in which the fertilization amount determined by the fertilization mode using the fertilization map and the fertilization amount determined by the fertilization mode using soil information are added after weighting respectively.

[0022] According to the seventh invention, in addition to the effects of any one of the first or sixth inventions, fine variable fertilization according to the needs of the operator can be realized. Also, the quality of fertilization can be improved by a comprehensive evaluation of the field.

[0023] The eighth invention is the invention according to any one of the first or seventh inventions, The work vehicle is configured to be capable of automatically traveling on a preset target travel route, and further, a plurality of stop positions for temporarily stopping the automatic travel are preset on the target travel route. When the portable information terminal is subjected to a predetermined operation during the automatic travel of the work vehicle, it is configured to skip the preset stop positions.

[0024] According to the eighth invention described above, in addition to the effects of the first or seventh invention, it is possible to realize fine variable fertilization according to the needs of the operator. Further, the quality of fertilization can be improved by a comprehensive evaluation of the field.

[0025] A ninth invention is the first invention described above, characterized in that learning of soil information by the soil information learning unit can be started or ended by an operation of the portable information terminal.

[0026] According to the ninth invention described above, in addition to the effects of the first invention, soil information can be learned at a desired location and timing of the operator, thus improving convenience.

Advantages of the Invention

[0027] According to the present invention, it is possible to provide a work vehicle that can continue work while automatically adjusting the fertilization amount even when the position information of the own vehicle cannot be obtained during work travel.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, the basic configuration of the work vehicle 1 will be described below.

[0030] <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. In this specification, as shown 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". Also, the work vehicle 1 is simply referred to as the "airframe".

[0031] The work vehicle 1 according to this embodiment has, as an example, the configuration of a rice transplanter. Specifically, as shown in FIG. 1, as its basic configuration, it includes a traveling vehicle body 2 (hereinafter also simply referred to as the "vehicle body") that travels in the field, a seedling planting unit 3 that plants seedlings in the field, a fertilizer application device 4 that applies fertilizer to the field, a positioning device 5 that measures the position of the airframe, 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. Also, it is provided with a portable information terminal 6 (see FIGS. 3 and 5) for an operator to remotely operate the work vehicle 1.

[0032] <Configuration of Traveling Vehicle Body> The traveling body 2 is a travelable body that forms the main body of the work vehicle 1. This traveling body 2 includes a main frame 2a that extends in the longitudinal direction of the machine body and forms the machine body skeleton, and a rear frame 2b that extends in the width direction and is attached to the rear end portion of the main frame 2a. A floor step 2c on which an operator can board is provided above the main frame 2a, and a control unit 7 that controls the operation and a control seat 7g on which the operator sits are provided on the floor step 2c.

[0033] Further, the engine E, which is the power source of the traveling body 2, is disposed below the control seat 7g. As shown in FIG. 1, the power output from the engine E is transmitted from the hydrostatic continuously variable transmission (HST) e2 to the transmission case e3 via a belt-type power transmission mechanism e1 provided below the floor step 2c.

[0034] The hydrostatic continuously variable transmission e2 is a mechanism in which the opening degree 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, the vehicle speed can be adjusted.

[0035] The power transmitted to the transmission case e3 is shifted inside it, and further branched and transmitted to the driving power for the pair of left and right front wheels 9 and the pair of left and right rear wheels 10 and the working power for the seedling planting unit 3. The driving power 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). In addition, it is transmitted to the pair of left and right rear wheels 9 via the pair of left and right rear wheel drive 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 unit 3.

[0036] The control unit 7 is equipped with various operating members for the operator to operate. Specifically, it includes a main shift lever 7a for changing the forward and backward movement and vehicle speed of the traveling vehicle body 2, a steering wheel 7b for steering a pair of left and right front wheels 9, a straight - ahead assist lever 7c for starting or ending straight - ahead control (one of the automatic driving modes) in the control device C, and an operation panel 7d provided with various operation switches. Further, a monitor 7e capable of displaying various information is provided on this operation panel 7d. Also, as a steering mechanism for steering the work vehicle 1, in addition to the steering wheel 7b, the control unit 7 includes a steering shaft 7f, a pitman arm, and tie rods (not shown), etc. By these mechanisms, according to the rotation operation of the steering wheel 7b, the steering angle of the front wheels 9, which are the steering wheels, is changed. Also, a driver's seat 7g is arranged behind the steering wheel 7b.

[0037] <Configuration of the seedling planting unit> The seedling planting unit 3 is attached to the rear part of the traveling vehicle body 2 via a lifting link device 11. The lifting link device 11 includes an upper link arm 11a and a pair of left and right lower link arms 11b, and is configured to be able to lift the seedling planting unit 3.

[0038] The front - side 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 at the lower part of the seedling planting unit 63.

[0039] Here, when an 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 to the rear, and the seedling planting unit 3 is configured to be lifted to the non - working position. When the seedling planting unit 3 is in the non - working position, its lower end is located at substantially the same height as the bottom of the main frame 2a.

[0040] On the other hand, when the lifting hydraulic cylinder 14 is extended hydraulically, the upper link arm 11a is rotated downward backward, and the seedling planting section 3 is lowered to a working position (the position shown in FIG. 1) where the seedling planting operation is possible.

[0041] As shown in FIG. 1, the seedling planting section 3 includes a seedling placing table 3a for leaning a mat-shaped seedling with soil (hereinafter referred to as "seedling mat"), a planting device 3b provided behind and below the seedling placing table 3a, a center float 3c provided at the lower part of the seedling planting section 3b, and side floats 3d arranged on the left and right of the center float 3c.

[0042] A plurality of planting devices 3b are provided side by side in the width direction of the work vehicle 1, and each planting device 3b includes a pair of left and right 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 and alternately take out the seedlings located at the lower end of the seedling placing table 3a and plant them in the field.

[0043] The center float 3c and the side floats 3d are each configured to slide on the field and level the ground as the work vehicle 1 travels, and the seedlings are planted in the field leveled by each float 3c, 3d by each planting device 3b. Further, the center float 3c and the side floats 3d are each configured to be swingable in accordance with the unevenness of the field.

[0044] <Configuration of Fertilizer Applicator> FIG. 2 is a schematic left side view of the fertilizer applicator 4 shown in FIG. 1. The fertilizer applicator 4 includes an air chamber 4a extending in the left-right direction of the machine body, a blower 4b for pumping air from the left to the right through the air chamber 4a, a fertilizer hopper 4c for storing fertilizer to be supplied to the field, a plurality of feeding devices 4d provided below the fertilizer hopper 27, a plurality of connecting pipes 4e provided below each feeding device 4d and having the front end 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.

[0045] The blower 4b is provided with an intake duct 4g. When a blower motor (not shown) is driven, the air sucked through the intake duct 4f is supplied into the air chamber 4a. The air supplied into the air chamber 4a is supplied into each fertilizer hose 4f through each connecting pipe 4e while being pumped to the right.

[0046] Each feeding device 4d is provided with an opening at the upper part for receiving the fertilizer dropped and supplied from the fertilizer hopper 4c, and is internally provided with a feeding roll 4i having a feeding groove 4h on the outer peripheral surface. As the feeding shaft 4j inserted through a hole (not shown) penetrating the feeding roll 4i in the left - right direction rotates, the feeding roll 4i rotates. Thereby, the fertilizer in the feeding groove 4h is fed downward of the feeding device 4d. The fertilizer fed by the feeding roll 4i is supplied into the connecting pipe 4e. At this time, the fertilizer supplied into the connecting pipe 4e is supplied to the field through the fertilizer hose 6f by the air supplied from the front air chamber 4a.

[0047] Here, the fertilization amount adjustment motor 4m for rotating the feeding shaft 4j has its rotation speed controlled by the control device C. That is, since the amount of fertilizer fed by the feeding device 4d is determined according to the rotation speed of the feeding roll 4i, the control device C can control the fertilization amount of the fertilization device 4 by controlling the fertilization amount adjustment motor 4m. The fertilization amount, more specifically, is the weight of the fertilizer supplied per unit area of the field, and is determined, for example, by the kg of the fertilizer supplied per 10a (1 are). Therefore, the control device C controls the rotation speed of the feeding roll 4i to be the target speed calculated based on the target fertilization amount according to the target fertilization amount. Note that the rotation speed of the feeding roll 4i is controlled to be faster as the target fertilization amount is larger and slower as the target fertilization amount is smaller.

[0048] <Configuration of the 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. This positioning device 5 is disposed at the upper end of a frame material that extends upward in the front part of the traveling body 1, and serves the function of acquiring position information of the vehicle. Here, position information refers to information that indicates the position of the work vehicle 1, and includes at least information that indicates the latitude and longitude of the vehicle. The position information measured by the positioning device 5 is transmitted to the control device C (see FIG. 5).

[0049] <Configuration of soil information acquisition unit> The soil information acquisition unit J measures the soil in the field to determine the soil fertility (i.e., The soil information acquisition unit J acquires information indicating the degree of soil fertility (the degree of soil fertility). 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 vehicle body 2, and is capable of measuring the cultivated soil depth by measuring the depth to which the vehicle body sinks 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. The SFV value is a numerical value equivalent to the EC value (Electric Conductivity), and is expressed in units of 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.

[0050] <Mobile information terminal configuration> FIG. 3 is a schematic plan view of the portable information terminal of FIG. The portable information terminal 6 is an information processing device separate from the traveling vehicle body 2, and is, for example, an information processing device that can be carried by an operator, such as a smartphone or a tablet. This portable information terminal 6 includes a display unit 6a, an operation unit 6b, a fertilization map storage unit 6c, a fertilization map setting unit 6c, a fertilization map storage unit 6d, an NDVI value acquisition unit 6e, and a communication control unit 6f (see FIG. 5). Regarding the fertilization map Dh, details will be described later.

[0051] The display unit 6a has a function of outputting video and audio, and is configured by, for example, a liquid crystal panel having a speaker. The operation unit 6b is composed of a plurality of pressure detection type buttons and the like. The fertilization map 6c serves to set the fertilization map Dh, which will be described later, in the fertilization map storage unit 6c and the control device C. The data regarding such a fertilization map Dh may be configured to be acquired from an external server SV, or may be configured to be able to generate data based on the operation of the operation unit 6b, and may be configured to be set by the operation of the operation unit 6b related to the fertilization amount setting by the operator.

[0052] The fertilization map storage unit 6d is a memory having a storage area, and is composed of a RAM or the like, but may be composed of a detachable recording medium such as an SD card. The data of the fertilization map Dh, which will be described later, is stored in advance in this fertilization map storage unit 6c before the start of work.

[0053] The NDVI value acquisition unit 6e functions to acquire the NDVI value (Normalized Difference Vegetation Index) of the field to be worked on. The NDVI value is calculated from the reflectance of infrared rays, etc. for each location in the field, based on, for example, a satellite image of the field before harvest in the previous year in which the field where the seedlings are to be planted is shown. Also, the satellite image of the field before harvest in the previous year in which the field where the seedlings are to be planted is shown is acquired from an external server SV connected via the network NW. The NDVI value is represented by an integer value from 0 to 200, and it is presumed that the higher the value, the higher the fertility of the soil. Information regarding the calculated NDVI value of the field is linked to the data of the fertilization map Dh for each location 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 NDVI value of the field.

[0054] Also, the mobile information terminal 6 can transmit and receive various information via wireless communication with the work vehicle 1 and the external server SV via the network NW by 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. As a result, the operator can remotely give various instructions and make various settings such as work start, travel start, forward and backward movement, and stop without boarding the work vehicle 1 by operating the mobile information terminal 6.

[0055] <Fertilization Map> FIG. 4 is a conceptual diagram of the data configuration of the fertilization map Dh. The fertilization map Dh is data in which the 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 location in the area of the field, and information on the target fertilization amount set for each section of the field.

[0056] Specifically, as shown in FIG. 4, in the fertilization map Dh, any point P within a substantially 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 that point P (in the illustrated example, X = 210, Y = 10). That is, it is configured such that the point P within the field area R can be specified from the position information indicating the latitude and longitude of the aircraft within the field.

[0057] Furthermore, the field area R is divided into rectangular sections K of a predetermined size in a matrix form. The fertilization map Dh includes, for each section K, a section number for specifying the section, a range (range X, range Y) on the two-dimensional coordinates of the section, and information on the target fertilization amount M and NDVI value set for that section K. In the illustrated example, in the case of section K1, the section number is P31, the range is X coordinate: 200 to 300, Y coordinate: 0 to 100, and the target fertilization amount is 30. Note that the target fertilization amount M is set, for example, as the number of Kg of fertilizer per 10a (are).

[0058] Note that the NDVI value of each section of the fertilization map Dh is linked and recorded with the NDVI value of that section acquired by the NDVI value acquisition unit 6e. The NDVI value of each section acquired by the NDVI value acquisition unit 6e is updated, for example, every year by the acquisition of new NDVI value information by the NDVI value acquisition unit 6e, and it is possible to compare the transition of the NDVI value for each section of the field (if it is updated every year, the NDVI values for the current and past years). More specifically, the average value of the NDVI values measured at a plurality of points belonging to each section is recorded as the NDVI value of the entire section.

[0059] With such a data configuration, the control device C can, by referring to the fertilization map Dh, identify the section K to which a point in the field to be worked belongs from the position information of any point in the field, obtain the information on the target fertilization amount M set for the identified section, and control the fertilization amount of the fertilizer applicator 4 so as to achieve the obtained target fertilization amount M. Note that the target fertilization amount M for each section of the fertilization map Dh can be set in advance by the operator through the operation of the portable information terminal 6. Thereby, it is possible to set the fertilization amount considering the fertility, etc. for each section of the field.

[0060] That is, for each section of the fertilization plan map Dh, as the target fertilization amount M, the fertilization amount of the fertilizer to be applied to the corresponding area of the field is input and set. This target fertilization amount M may be obtained, for example, according to the distribution of the grain harvest amount last year, or may be determined by the operator based on experience, and is determined by an arbitrary method.

[0061] <Configuration of the control device> FIG. 5 is a block diagram showing the configuration of a control system including the control device C of the work vehicle 1. The control device C is an information processing device configured by combining a plurality of ECUs (Electronic Control Units). Each of these plurality of ECUs is configured to include a CPU that performs arithmetic processing and a memory that can read and write information necessary for the arithmetic processing. The CPU operates according to various control programs stored in the memory, thereby realizing the configuration described as functional blocks in FIG. 2.

[0062] As shown in FIG. 5, the control device C includes an output processing unit c1, a communication processing unit c2, an input processing unit c3, a traveling control unit c4, an information storage unit c5, a traveling management unit c6, a fertilization amount setting unit c7, and a fertilizer applicator control unit c8, and these are configured to be able to transmit and receive information to and from each other via a communication bus BA.

[0063] The output processing unit c1 serves the function of an input / output interface and is connected to a group of traveling system devices M1 that control the traveling functions such as the traveling, stopping, and changing of the traveling direction of the work vehicle 1, a group of working system devices M2 that control the working functions such as fertilizing and planting, and a monitor 7e that outputs video and audio. For example, in the present embodiment, the group of traveling system devices M1 includes mechanisms such as a steering actuator, an engine E, a transmission, and a brake, and the group of working system devices M2 includes mechanisms such as a PTO clutch, a PTO transmission, a braking device, and a lift hydraulic cylinder 14.

[0064] The communication processing unit c2 is a communication mechanism that connects to external devices physically separated from the control device C via a network NW and exchanges information through communication. In the present embodiment, the communication processing unit c2 is connected to, for example, a portable information terminal 6 and is capable of transmitting and receiving various types of information.

[0065] The input processing unit c3 is a mechanism that receives input of information from connected external devices and is capable of acquiring various types of information such as positioning information and detection information. In the present embodiment, the input processing unit c3 is connected to a positioning device 5, a traveling system detection sensor S1 including a steering angle detection means, various sensors that detect the operating states of a seedling planting unit 3 and a fertilizer applicator 4, and a working system detection sensor S2 including a soil information acquisition unit J.

[0066] Further, the control device C includes a traveling control unit c4 that controls the traveling of the work vehicle A, an information storage unit c5 that stores various types of information, and a route management unit c6 that performs processing related to a target traveling route L.

[0067] The traveling control unit c4 is a mechanism that includes a program and various circuits for controlling the traveling of the work vehicle 1 during automatic traveling (automatic steering) and manual traveling (manual steering), and includes an automatic traveling control device c41 that controls the group of traveling system devices M1 during automatic traveling and a manual traveling control device c42 that controls the group of traveling system devices M1 during manual traveling.

[0068] The automatic travel control device c41 includes a self-vehicle position calculation unit c411 that calculates the position of the own vehicle in the field by acquiring the positioning information (position information) of the positioning device 5, a self-vehicle azimuth calculation unit c412 that calculates the azimuth of the own vehicle, a deviation calculation unit c413 that calculates a deviation, and a steering angle calculation unit c414 that calculates a steering angle from the detection information of the travel system detection sensor group S1. The automatic travel control device c41 configured in this way calculates a deviation by the deviation calculation unit c413, and based on the calculated deviation, calculates the steering angle of the steering wheel 7b appropriate for the work vehicle 1 to travel along the target travel route L, and controls the steering actuator so as to obtain the calculated steering angle, enabling automatic travel of the work vehicle 1 on the target travel route L.

[0069] The information storage unit c5 is a storage device capable of storing various information, and is composed of, for example, an HDD (Hard Disc Drive) or an SSD (Solid State Drive). The information storage unit c5 includes a field information storage unit c51 that stores information about the field (hereinafter referred to as "field information"), a route information storage unit c52 that stores information about 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 related to the 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 operator. Thereby, the operator can analyze the field and the work.

[0070] The field information storage unit c51 is a storage area for storing field information. Here, the field information includes, for example, information such as the size, shape, and position of the field to be worked, and the position data of the ridges that define the boundary line of the field.

[0071] The route information storage unit c52 is a storage 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.

[0072] The work information storage unit c53 is a storage 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 preset by the operator and the type of work (fertilization, planting, etc.) is included.

[0073] The travel management unit c6 is a program for managing 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.

[0074] The route calculation unit c61 calculates a target travel route L based on field information, work information, etc. FIG. 6 is an explanatory diagram for explaining the target travel route of the work vehicle 1. Here, the target travel route L refers to the travel route that the work vehicle 1 aims for during automatic travel, and the information indicating the target travel route L is composed of position information indicating the trajectory of the target travel route L. The route calculation unit c61 calculates the target travel route L by, for example, the following design procedure.

[0075] First, field information is acquired, and the inside of the field area R is divided into a headland travel area R1 where the vehicle travels in a circular manner to perform work and a straight travel area R2 where the vehicle travels in a straight line to perform work. Here, the headland travel area R1 is set as a frame-shaped area having a work width W, and a rectangular straight travel area R2 is set inside the headland travel area R1. Note that the field area R is an area indicating the field, and the shape and size of the area are designed corresponding to the shape and size of the field.

[0076] Next, a headland travel route l1 that travels in a circular manner inside the headland travel area R1 is designed (work routes VI to IX). Subsequently, a plurality of straight travel routes l2 that travel in a straight line inside the straight travel area R2 are designed (work routes I to V). Here, in order to prevent the work from overlapping at one point between the straight travel routes l2, an interval substantially the same as the work width W is provided.

[0077] Next, the straight driving routes l2 are moved in one stroke, and a non-operation route l3, which is a route where no operation is performed for turning the straight driving routes l2 and moving from the straight driving routes l2 to the headland driving route l1, is designed. Information indicating the target driving route L calculated as described above is stored in the route information storage unit c52.

[0078] The driving order setting unit c62 acquires information indicating the target driving route L calculated by the route calculation unit c61, and sets the driving order of the operation routes (in the illustrated example, operation routes I to IX), which are the routes for performing the operations included in the target driving route L. Such a driving order is set based on a predetermined rule, but the operator can also change it to an arbitrary driving order by operating the portable information terminal 6 or the operation panel 7d. The setting information of such a driving order is stored in the route information storage unit c52 together with the information indicating the target driving route L.

[0079] For example, in the illustrated example of FIG. 6, the driving order is set in the order of operation route I, operation route II, operation route III, operation route IV, operation route V, operation route VI, operation route VII, operation route VIII, and operation route IX. Note that the arrow directions of the headland driving route l1 and the straight driving route l2 shown in the figure indicate the driving direction of the work vehicle 1, but depending on the driving order, it is not necessarily limited to this direction. At the start of the automatic driving of the work vehicle 1, the work vehicle 1 is moved to the vicinity of the work start point Ps. Such movement is performed by the operator's driving, but based on the position information of the work start point Ps, the work vehicle 1 may be automatically driven. Further, although the work vehicle 1 is configured to shift to driving on the headland driving route l1 from the straight driving route l2 when it reaches the work end point Pe of the straight driving route l2 in FIG. 6, depending on the driving order, it can also be configured to shift to driving on the straight driving route l2 from the headland driving route l1.

[0080] The stop position setting unit c63 sets the position where the work vehicle 1 temporarily stops during automatic driving on the target driving route L. Such a stop position is set based on a predetermined rule, but the operator can also change the set stop position by operating the portable information terminal 6 or the operation panel 7d. Information regarding the set stop position is stored in the route information storage unit c52. When the work vehicle 1 reaches the stop position during automatic driving, it temporarily stops the automatic driving. After the temporary stop, it is configured to resume automatic driving by instructing the resumption of driving through a predetermined operation of the portable information terminal 6. Thereby, the operator can check the remaining amounts of fuel, fertilizer, seedlings, etc. of the work vehicle 1 at the stop position, and can replenish materials if necessary.

[0081] The stop position can be set at the end positions of working routes I to IX. In the illustrated example, it is set at the end positions Pm1 and Pm2 of working routes II and IV on one end side of the field (that is, the side where the operator can easily check). Note that it may also be set at the end positions of working routes I, III, and V on the other end side of the field.

[0082] Also, when the portable information terminal 6 is subjected to a predetermined operation during the automatic driving of the work vehicle 1, the stop position setting unit c63 is configured to skip the set stop position (continue automatic driving without stopping). The number of skips can be reserved by accumulating the number before reaching the stop position, and such number of skips is stored in the work information storage unit c53 each time. For example, it can be configured such that pressing the "F" button of the operation unit 6b and the "right" and "enter" buttons simultaneously increases the number of skips of the stop position by one. Furthermore, it can be configured such that pressing the "F" button of the operation unit 6b and the "left" and "back" buttons simultaneously decreases the number of skips of the stop position by one. Thereby, for example, according to the size of the field, the number of stops for material replenishment can be flexibly changed. It can be done.

[0083] The fertilization amount setting unit c7 is a program that performs the function of setting the fertilization amount, and includes a basic fertilization amount setting unit c71 and a soil information learning unit c72.

[0084] The basic fertilization amount setting unit c71 is a program that performs the function of setting the basic fertilization amount. The setting of such a basic fertilization amount can be performed by operating the portable information terminal 6 or the operation panel 7d, and the set value of the basic fertilization amount is stored in the work information storage unit c53 and referred to when necessary in the fertilization work. Here, the basic fertilization amount is the basic fertilization amount for the field to be worked, and in other words, it is the basic value of the fertilization amount set for each field. The basic fertilization amount is set, for example, in kg of fertilizer per 10a (are).

[0085] <Learning (Teaching) of 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 the learning of soil information, and stores the soil information (cultivation depth, SFV value) acquired from the soil information acquisition unit J during the learning in the work information storage unit c53. Furthermore, each time the soil information (cultivation depth, SFV value) is acquired, a growth evaluation value W using the cultivation depth and the SFV value is calculated and stored in the work information storage unit c53. Here, the growth evaluation value W indicates an evaluation value of the ease of growth of seedlings in the soil, and the larger the value, the easier the growth is represented.

[0086] The growth evaluation value W can be calculated, for example, by the following formula (1). (Formula 1) W = α × SFV value + β × cultivation depth α and β are weighting coefficients. Thereby, the growth evaluation value W becomes a larger value as the SFV value is larger and as the cultivation depth is deeper.

[0087] When the preset start condition is satisfied, the soil information learning unit c72 starts learning the soil information, and when the preset end condition is satisfied, the soil information learning unit c72 ends the learning of the soil information. The start condition and end condition for learning the soil information are set and stored in the work information storage unit c53 in advance, but the operator can change the settings by operating the portable information terminal 6 or the operation panel 7d.

[0088] The start condition for learning soil information can be, for example, that the automatic driving has started. Also, it can be conditioned on reaching the start point of any one of work routes I to IX (which can be selected and set by the operator), which are the routes for performing work, on the target driving route L (see Fig. 6). Further, it can be conditioned on reaching the start point of any one of the work routes I to IX that is preset on the target driving route L.

[0089] The end condition for learning soil information can be, for example, that the automatic driving has ended (the driving has stopped). Also, it can be conditioned on reaching the end point of any one of work routes I to IX (which can be selected and set by the operator), which are the routes for performing work, on the target driving route L. Further, it can be conditioned on reaching the end point of any one of the work routes I to IX that is preset on the target driving route L.

[0090] As preferable start and end conditions for learning soil information, for example, after the start of work by automatic driving, learning of soil information is started on the condition of reaching the start point of the third step (work route III) of the straight driving route l2, and learning of soil information is ended on the condition of reaching the end point of the third step (work route III) of the straight driving route l2. Note that the third step is an example, and depending on the size of the field, it may be the first step or the fourth step, and the operator can select and set any step. This is because by learning soil information in one work step within the straight driving area R2, more accurate soil information for the entire field can be learned. Conversely, if soil information is learned near the edge of the field, for example, due to the presence of a water channel beside the field, the measured value of the soil information may be a biased value and may not necessarily reflect the entire field.

[0091] In addition, regardless of the above conditions, the soil information learning unit c72 is configured to be able to start or end the learning of soil information at the desired timing of the operator by a predetermined operation (for example, a button pressing operation) of the mobile information terminal 6 or the operation panel 7d. Thereby, since the soil information can be learned at the desired location and timing of the operator, the convenience is improved.

[0092] When the learning of the soil information is completed, the soil information learning unit c72 calculates the average values of the soil cultivation depth, the SFV value, and the growth evaluation value W during the learning 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 is referred to as the growth evaluation value W based on the learning result in the following description.

[0093] The fertilizer application device control unit c8 includes a fertilizer application amount control unit c81, a fertilizer application mode execution unit c82, and a fertilizer application mode management unit c83.

[0094] The fertilizer application amount control unit c81 is a program that transmits a control signal for controlling the fertilizer application amount to the fertilizer application device 4, thereby fulfilling the function of controlling the fertilizer application amount of the fertilizer application device 4.

[0095] The fertilizer application mode execution unit c82 is a program capable of executing a plurality of fertilizer application modes with different methods for determining the fertilizer application amount. By passing the information on the fertilizer application amount (control amount) of the fertilizer application device 4 to the fertilizer application amount control unit c81, it fulfills the function of determining the fertilizer application amount of the fertilizer application device 4 during the fertilizer application operation.

[0096] The fertilizer application mode execution unit c82 includes a basic fertilizer application amount application mode c821, a fertilizer application map utilization application mode c822, a soil information utilization application mode c823, and a hybrid application mode c824 as executable fertilizer application modes (programs).

[0097] <Basic Fertilizer Application Amount Application Mode> The basic fertilization rate application mode c821 is a mode that determines the fertilization rate of the fertilizer applicator 4 as a preset basic fertilization rate. That is, during the execution of the basic fertilization rate application mode c821 (i.e., when the basic fertilization rate application mode is selected), the fertilization rate of the fertilizer applicator 4 is controlled to be the basic fertilization rate, so it is usually constant. Note that the basic fertilization rate appropriately refers to the value set in the work information storage unit c53. When the value set in the work information storage unit c53 is changed, the fertilization rate of the fertilizer applicator 4 is also changed.

[0098] <Fertilization map utilization fertilization mode> The fertilization map utilization fertilization mode c822 is a mode that determines the fertilization rate of the fertilizer applicator 4 based on the information of the fertilization map Dh. That is, during the execution of the basic fertilization rate application mode c821 (i.e., when the fertilization map utilization fertilization mode is selected), the fertilization rate of the fertilizer applicator 4 is determined according to the following procedure.

[0099] This fertilization map utilization fertilization mode c822 acquires the position information (latitude, longitude) of the own machine from the positioning device 5 at a predetermined time interval, and each time it refers to the information of 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 the section K on the fertilization map Dh. Next, it acquires the information of the target fertilization rate M set for the identified section K, and determines the acquired fertilization rate as the fertilization of the fertilizer applicator 4.

[0100] <Soil information utilization fertilization mode> The soil information utilization fertilization mode c823 is a mode that determines the fertilization rate of the fertilizer applicator 4 based on soil information. That is, during the execution of the soil information utilization fertilization mode c821 (i.e., when the soil information utilization fertilization mode is selected), the fertilization rate of the fertilizer applicator 4 is determined according to the following procedure.

[0101] The soil information-based fertilization mode c823 acquires soil information from the soil information acquisition unit J at a predetermined time interval, and calculates the 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 based on the learning result stored in the work information storage unit c53, and the fertilization amount of the fertilizer applicator 4 is determined according to the comparison result. The fertilization amount determined by the soil information-based fertilization mode c823 can be calculated, for example, by the following formula (2).

[0102] (Formula 2) Fertilization amount = Basic fertilization amount × (100 - Fertilizer reduction rate (%)) / 100 However, when the growth evaluation value W > the growth evaluation value W based on the learning result, the fertilizer reduction rate (%) = 20 × the calculated growth evaluation value W / the growth evaluation value W based on the learning result; when the growth evaluation value W < the growth evaluation value W based on the learning result, the fertilizer reduction rate (%) = 0.

[0103] 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 fertile the location where the soil information was acquired is presumed to be compared to the average fertility of the entire field. Therefore, the fertilizer reduction rate (%) is increased, and accordingly, the fertilization amount is determined to be reduced. Conversely, when the calculated growth evaluation value W is lower than the growth evaluation value W based on the learning result, the location where the soil information was acquired is presumed to be less fertile than the average fertility of the entire field. Therefore, the fertilizer reduction rate (%) is set to 0, and the basic fertilization amount is determined as the fertilization amount without reducing the fertilizer. According to the soil information-based fertilization mode c824 configured in this way, variable fertilization can be performed by increasing or decreasing the fertilization amount while reflecting the real-time measured soil information.

[0104] In addition, when the soil information-based fertilization mode c824 is immediately after the start of work and the soil information learning by the soil information learning unit c72 has not been performed yet, and there is no information on the growth evaluation value W based on the learning result in the work information storage unit c53, the fertilizer reduction rate (%) is set to 0 until the soil information learning by the soil information learning unit c72 is completed, and the basic fertilization amount is determined as the fertilization amount of the fertilizer applicator 4.

[0105] <Hybrid fertilization mode> The hybrid fertilization mode c824 is a mode that determines the fertilization amount of the fertilizer applicator 4 by using the information of the fertilization map and the soil information. More specifically, during the execution of the hybrid fertilization mode c824 (that is, when the hybrid fertilization mode is selected), the fertilization amount determined by the fertilization map utilization fertilization mode c822 and the fertilization amount determined by the soil information utilization fertilization mode c824 are combined to determine the fertilization amount.

[0106] Specifically, assuming that the fertilization amount determined by the fertilization map utilization fertilization mode c822 is M1 (kg / 10a) and the fertilization amount M2 (kg / 10a) determined by the soil information utilization fertilization mode c823, the fertilization amount determined by the hybrid fertilization mode c824 can be calculated, for example, by the following formula (3).

[0107] (Formula 3) Fertilization amount = (γ1 × M1 + γ2 × M2) / 2 However, γ1 and γ2 are weighting factors that can be arbitrarily set by the operator, and γ1 + γ2 = 1. In the setting of the weighting factor, if the value of γ1 is increased, the fertilization amount M1 determined by the fertilization map utilization fertilization mode c822 is more emphasized, and if the value of γ2 is increased, the fertilization amount M2 determined by the soil information utilization fertilization mode c823 is more emphasized. Thereby, fine variable fertilization according to the needs of the operator can be realized. In addition, the quality of fertilization can be improved by a comprehensive evaluation of the field.

[0108] The fertilization mode management unit c83 functions to manage the fertilization mode executed by the control device C, and includes a fertilization mode selection switching unit c831 and a fertilization mode automatic switching unit c832.

[0109] The fertilization mode selection switching unit c831 is a program that enables the operator to select the fertilization modes executable by the above-mentioned fertilization mode execution unit c82 through a predetermined operation. For example, a list of selectable fertilization modes is displayed on the display unit 6a of the portable information terminal 6 or the monitor 7e, and the operator is allowed to select the desired fertilization mode by operating the operation unit 6b or the operation panel 7d, and the selected fertilization mode is executed by the fertilization mode execution unit c82.

[0110] <Automatic switching process for fertilization mode> The automatic fertilization mode switching unit c832 is a program that performs the function of automatically switching the fertilization mode (hereinafter referred to as the automatic fertilization mode switching function). 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.

[0111] Figure 7 is a flowchart showing the flow of the automatic fertilization mode switching process. When starting the automatic fertilization mode switching process, the automatic fertilization mode switching unit c832 executes the fertilization mode using the fertilization map c822 (step #1). Thereby, fertilization is performed in the fertilization mode using the fertilization map.

[0112] Next, it is determined whether there is a reception failure in the positioning device 5 (step #2). If it is determined that there is a reception failure in the positioning device 5, the fertilization mode using soil information c823 is executed (step #3). Thereby, the fertilization mode is automatically switched, and fertilization is performed in the fertilization mode using soil information. As a result, even when a reception failure occurs in the positioning device 5 and a problem occurs in fertilization in the fertilization mode using the fertilization map, the fertilization work can be continued smoothly, and a significant decrease in work efficiency can be prevented.

[0113] Subsequently, the automatic fertilization mode switching unit c832 determines whether the reception failure of the positioning device 5 has been resolved (step #4). If it has been resolved (Y in step #4), the fertilization mode using the fertilization map c822 is executed (step #1). Thereby, it is possible to quickly return to fertilization in the fertilization mode using the fertilization map in response to a temporary reception failure of the positioning device 5.

[0114] Also, if the reception failure of the positioning device 5 is not resolved (N in step #4), the soil information-based fertilization mode is continued, and it is determined whether soil information cannot be acquired (step #5). If it is determined that the soil information can be acquired without problems (N in step #5), the soil information-based fertilization mode is continued (step #3).

[0115] On the other hand, if the soil information cannot be acquired (Y in step #5), that is, if it is determined that the control device C cannot acquire the soil information from the soil information acquisition unit J and some malfunction has occurred, the basic fertilization amount fertilization mode c821 is executed (step #6). As a result, the fertilization mode is automatically switched, and fertilization is performed according to the basic fertilization amount fertilization mode. Consequently, even if some malfunction occurs in the soil information acquisition unit J and there is a problem in the progress of fertilization according to the soil information-based fertilization mode, the fertilization work can be smoothly continued, and a significant decrease in work efficiency can be more suitably prevented.

[0116] Thereafter, returning to step #4, if the reception failure of the positioning device 5 is resolved, the fertilization returns to the fertilization using the fertilization map mode (step #1), and if it is determined that the soil information can be acquired without problems (N in step #5), the fertilization returns to the soil information-based fertilization mode (step #3).

[0117] The embodiments of the present invention have been described above. The present invention is not limited only to the aspects of the above-described embodiments. Needless to say, it can be appropriately changed within the scope of the technical idea. For example, in the embodiment described in FIG. 7, in step #2, it is configured to determine whether a reception failure has occurred in the positioning device 5, but it may be configured to determine whether communication between the control device C and the portable information terminal 6 has become impossible. That is, when any problem occurs in the communication between the control device C and the portable information terminal 6, the control device C cannot obtain the information of the fertilization map Dh from the portable information terminal 6. Further, at this time, when it is determined that communication between the control device C and the portable information terminal 6 has become possible after automatically switching from the fertilization map utilization fertilization mode to the soil information utilization fertilization mode due to a communication problem, it is preferably configured to automatically switch from the soil information utilization fertilization mode to the fertilization map utilization fertilization mode. Thereby, when the communication failure is resolved, it is possible to quickly switch to the fertilization map utilization fertilization mode, improving convenience.

[0118] Also, for example, in the embodiment described in FIG. 7, the execution priority of the fertilization mode is the fertilization map utilization fertilization mode, the soil information utilization fertilization mode, and the basic fertilization amount fertilization mode, but it is not limited thereto, and the execution priority of the fertilization mode can also be the soil information utilization fertilization mode, the fertilization map utilization fertilization mode, and the basic fertilization amount fertilization mode (at this time, in the embodiment of FIG. 7, steps #1 and #3, and steps #2 and #4 are interchanged). Further, this priority may be configured to be selectable by an operator through a predetermined operation. Thereby, it is possible to perform fertilization according to the detailed needs of the operator.

Explanation of Reference Numerals

[0119] 1 Work vehicle 2 Traveling vehicle body 2a Main frame 2b Rear frame 2c Floor step 3 Seedling planting unit 3a Seedling mounting table 3b Planting device 3c Center float 3D side float 3E planter 3F drive shaft 4 Fertilizer applicator 4A air chamber 4B blower 4C fertilizer hopper 4D feeding device 4E connecting pipe 4F fertilizer hose 4G intake duct 4H feeding groove 4I feeding roll 4J feeding shaft 4M fertilizer rate adjustment motor 5 Positioning device 6 Portable information terminal 7 Control unit 7A main transmission lever 7B steering wheel 7C straight-ahead assist lever 7D operation panel 7E monitor 7F steering shaft 7G operator's seat 9 Front wheels 10 Rear wheels 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 unit

Claims

Claim 1 A work vehicle comprising a fertilizer application device and a positioning device for acquiring the position of the vehicle itself, and configured to acquire the target fertilizer application amount set for the section to which the vehicle position belongs by using a fertilizer application map in which the fertilizer application amount is set for each section of the farm field based on the vehicle position acquired by the positioning device, and to control the fertilizer application amount of the fertilizer application device, further comprising a soil information acquisition unit for acquiring soil information of the farm field and a control device for controlling the fertilizer application amount of the fertilizer application device, the soil information acquisition unit includes a soil tillage depth sensor for measuring the soil tillage depth of the soil and a fertility sensor for measuring the fertility of the soil, the control device includes a soil information learning unit for learning the acquired soil information, configured to be able to acquire the soil information from the soil information acquisition unit, and configured to be able to select and execute a fertilizer application map utilization fertilizer application mode for determining the fertilizer application amount of the fertilizer application device based on the information of the fertilizer application map, and a soil information utilization fertilizer application mode for determining the fertilizer application amount of the fertilizer application device by comparing the soil information acquired from the soil information acquisition unit with the soil information learned by the soil information learning unit. Further, during learning, the soil information learning unit is configured to calculate a growth evaluation value indicating the ease of seedling growth in the soil each time based on the acquired soil information, and to calculate a first growth evaluation value that is the average value of the growth evaluation values calculated during learning when the learning is completed, the control device is configured to calculate a second growth evaluation value each time based on the soil information acquired from the soil information acquisition unit during the execution of the soil information utilization fertilizer application mode, when the calculated second growth evaluation value is lower than the first growth evaluation value, determining the value of the preset basic fertilizer application amount as the fertilizer application amount, and when the calculated second growth evaluation value is higher than the first growth evaluation value, determining the value obtained by subtracting the preset basic fertilizer application amount as the fertilizer application amount. A work vehicle characterized by this. Claim 2 The control device is configured to automatically switch from the fertilizer application map utilization fertilizer application mode to the soil information utilization fertilizer application mode when it determines that the positioning device has received poor signals during the fertilizer application map utilization fertilizer application mode. The work vehicle according to claim 1, characterized by this. Claim 3 Furthermore, after the control device automatically switches from the fertilization map - based fertilization mode to the soil - information - based fertilization mode, when it determines that the reception failure of the positioning device has been resolved, the work vehicle according to claim 2 is characterized in that it automatically switches from the soil - information - based fertilization mode to the fertilization map - based fertilization mode.

4. The work vehicle further comprises a portable information terminal for storing information of the fertilization map, The control device is configured to be able to acquire information of the fertilization map from the portable information terminal through communication, and when it determines that communication between the control device and the portable information terminal has become impossible during the fertilization map - based fertilization mode, the work vehicle according to claim 1 is characterized in that it is configured to automatically switch from the fertilization map - based fertilization mode to the soil - information - based fertilization mode.

5. Furthermore, after the control device automatically switches from the fertilization map - based fertilization mode to the soil - information - based fertilization mode, when it determines that communication between the control device and the portable information terminal has become possible, the work vehicle according to claim 4 is characterized in that it is configured to automatically switch from the soil - information - based fertilization mode to the fertilization map - based fertilization mode.

6. The control device is further configured to be able to execute a basic fertilization amount fertilization mode in which a preset basic fertilization amount is determined as the fertilization amount of the fertilization device. During the soil - information - based fertilization mode, when it determines that soil information cannot be obtained from the soil information acquisition unit, the work vehicle according to claim 4 or claim 5 is characterized in that it is configured to automatically switch from the soil - information - based fertilization mode to the basic fertilization amount fertilization mode.

7. The control device is configured to be able to select and execute a hybrid fertilization mode in which the fertilization amount is determined by adding, after weighting, the fertilization amount determined by the fertilization map - based fertilization mode and the fertilization amount determined by the soil - information - based fertilization mode. The work vehicle according to claim 1 is characterized by this.

8. The work vehicle is configured to be able to automatically travel on a preset target travel route. Furthermore, a plurality of stop positions for temporarily stopping the automatic travel are preset on the target travel route. During the automatic travel of the work vehicle, when the portable information terminal storing information of the fertilization map is subjected to a predetermined operation, the work vehicle according to claim 1 is characterized in that it is configured to skip the preset stop positions.

9. The work vehicle according to claim 4, characterized in that learning of the soil information by the soil information learning unit can be started or terminated by operating the portable information terminal.

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