Work vehicles

Abstract

To provide a work vehicle that can effectively prevent fertilizer from being missed during application within a field. [Solution] A work vehicle 1 comprises a fertilizer dispenser 4 that rotates a fertilizer dispensing roll with an electric motor 4m, a control device C that controls the amount of fertilizer dispensed by the fertilizer dispenser 4 by controlling the rotation speed of the electric motor 4m, and a positioning device 5. Based on the position of the vehicle acquired by the positioning device 5, the work vehicle 1 uses a fertilizer map Dh, to which the amount of fertilizer dispensed is set for each plot K of the field, to acquire a target amount of fertilizer dispensed for the plot to which the vehicle belongs, and controls the amount of fertilizer dispensed by the fertilizer dispenser. The above problem is solved by providing a work vehicle characterized in that the control device C acquires detection information from a rotation speed detection sensor that detects the rotation speed of the electric motor 4m, and when the rotation speed of the electric motor 4m falls below a set lower limit rotation speed during work travel, it intermittently drives the fertilizer applicator 4 for a predetermined time.

Description

Technical Field

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

Background Art

[0002] Conventionally, for example, as described in Patent Document 1 below, by acquiring position information, while automatically traveling in a field, based on the information of a fertilization plan map in which a target fertilization amount is set for each predetermined section of the field, a work vehicle that automatically controls a fertilization device so as to achieve a target fertilization amount according to the position of the vehicle body in the field is known.

[0003] Also, for this type of work vehicle, for example, as described in Patent Document 2 below, the fertilization amount can be adjusted by controlling a motor that drives the fertilization device. Here, generally, a motor-controlled fertilization device can adjust the fertilization amount more precisely than a mechanically driven type, but when fertilizer clogging occurs, there is a risk that fertilization will stop due to insufficient torque. Therefore, Patent Document 2 discloses a technique of executing a forward and reverse rotation process of alternately driving the motor forward and backward when it is determined that the motor is in an overload state, and rotating a rotating member that feeds out fertilizer forward and backward to eliminate fertilizer clogging.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with the conventional technology described above, by the time the motor is detected as being overloaded, it may have already stopped due to fertilizer clogging, potentially resulting in areas of the field where fertilizer has not been applied (hereinafter referred to as "unapplied areas"). Furthermore, if unapplied areas occur in the field due to fertilizer clogging, the operator must manually apply fertilizer to those areas, which is time-consuming. In addition, it is difficult for the operator to identify unapplied areas, which could lead to missed spots in the work area of ​​the field.

[0006] Therefore, the present invention aims to solve these problems and provide a work vehicle that can prevent motor stoppage due to fertilizer clogging during work operation and properly prevent fertilizer leakage in the work area within the field. [Means for solving the problem]

[0007] To achieve the above objective, the first invention is: A work vehicle comprising a fertilizer dispenser that rotates a fertilizer dispensing roll using an electric motor, a control device that controls the amount of fertilizer dispensed by the fertilizer dispenser by controlling the rotation speed of the electric motor, and a positioning device that acquires the vehicle's own position, and configured to control the amount of fertilizer dispensed by the fertilizer dispenser by acquiring a target amount of fertilizer set for the section to which the vehicle's position belongs, using a fertilizer map in which the amount of fertilizer dispensed for each section of the field is set based on the vehicle's own position acquired by the positioning device, The control device is configured to acquire detection information from a rotation speed detection sensor that detects the rotation speed of the electric motor, and to intermittently drive the fertilizer applicator for a predetermined time when the rotation speed of the electric motor falls below a set lower limit rotation speed during work travel.

[0008] According to the first invention described above, if the rotational speed of the electric motor falls below a set lower limit rotational speed during operation, the fertilizer applicator is intermittently driven for a predetermined time, thereby clearing fertilizer clogging. This prevents the electric motor from stopping due to fertilizer clogging, and as a result, it is possible to properly prevent fertilizer leakage in the work area within the field.

[0009] The first invention, in addition to the configuration of the first invention described above, The control device is configured to record the machine's position when the rotational speed of the electric motor falls below a set lower limit rotational speed, and further, even after intermittently driving the fertilizer applicator, if the rotational speed falls below the set lower limit rotational speed, it records the machine's position and stops the operation. The system is characterized by its configuration to calculate the unspreaded section, which indicates the area where fertilizer could not be spread properly, based on a preset working width and recorded information about the machine's position, after stopping the work run, and to display the calculated unspreaded section.

[0010] According to the second invention described above, in addition to the effects of the first invention described above, the control device displays information regarding the calculated non-spreading sections, allowing the operator to understand the sections where fertilizer could not be spread properly. By applying additional fertilizer to these sections, it is possible to appropriately prevent fertilizer leakage in the work area within the field.

[0011] The third invention, in addition to the configuration of the second invention described above, The system is configured such that, after stopping work movement, upon receiving an instruction to resume work, it refers to the recorded information regarding the position of the machine, automatically reverses to a point where the rotation speed of the electric motor falls below a set lower limit rotation speed, and then resumes work movement.

[0012] According to the third invention described above, in addition to the effects of the second invention described above, it is possible to reduce the workload on workers, apply fertilizer to areas where it has not been applied, and more effectively prevent fertilizer leakage in the work area within the field.

[0013] The fourth invention, in addition to the configuration of the first invention, The control device is configured to store information about multiple fertilization maps, linked to a set value indicating the reliability of each fertilization map. Before the operation begins, it excludes fertilization maps with a reliability below a predetermined value from the list of candidates, allows the operator to select a fertilization map to use, and if multiple fertilization maps are selected, it creates a composite fertilization map by weighting the fertilization amounts in each section of the selected maps. Fertilization is then performed based on the created composite fertilization map.

[0014] The fourth invention provides, in addition to the effects of the first invention, By optimizing the amount of fertilizer applied by the fertilizer application device through fertilization based on a synthetic fertilization map, it is possible to prevent fertilizer leakage due to nutrient deficiencies.

[0015] The fifth invention provides, in addition to the effects of the first invention, The fertilizer applicator is equipped with a height detection sensor that detects the height of the top surface of the fertilizer stored in it, and the control device is configured to acquire the measurement information from the height detection sensor, and the control device is configured to calculate the actual weight of the fertilizer consumed during operation from the number of rotations of the fertilizer applicator and the change in the top surface height.

[0016] The fifth invention provides, in addition to the effects of the first invention, By calculating the actual weight of fertilizer consumed during operation, it is possible to prevent fertilizer leakage due to running out of fertilizer. [Effects of the Invention]

[0017] According to the present invention, even if the vehicle loses the ability to acquire its own position information while working, it is possible to provide a work vehicle that can continue working while automatically adjusting the amount of fertilizer applied. [Brief explanation of the drawing]

[0018] [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 in Figure 1. [Figure 3] Figure 3 is a perspective view of the main part of the same. [Figure 4] Figure 4 is a conceptual diagram of the data structure of the fertilizer application map. [Figure 5] Figure 5 is a block diagram showing the configuration of the control system including the control device in Figure 1. [Figure 6] Figure 6 is an explanatory diagram for explaining the target travel route of the work vehicle. [Figure 7] Figure 7 is a flowchart showing the processing of the work travel execution unit during work travel. [Figure 8] Figure 8 is a graph showing an example of the change in the rotational speed of the electric motor when fertilizer clogging occurs. [Figure 9] Figure 9 is an explanatory diagram for explaining the operation of the work vehicle during work travel. [Figure 10] Figure 10 is the same explanatory diagram. [Figure 11] Figure 11 is a flowchart showing the flow of the fertilizer application map selection process. [Figure 12] Figure 12 is an explanatory diagram for explaining the method of creating a synthetic fertilizer application map.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, based on the accompanying drawings, preferred embodiments of the present invention will be described in detail. First, the basic configuration of the work vehicle 1 will be described below. ​​​​​​​​​ 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 for the operator to remotely operate the work vehicle 1.

[0022] <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.

[0023] 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.

[0024] 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.

[0025] 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 to the pair of rear wheels 10, 10 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.

[0026] 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 straight-line control, which is one of the automatic driving functions, via the control device C, and an operation panel 7d equipped with various operation switches. Furthermore, the operation panel 7d is equipped with a monitor 7e capable of displaying various information. The monitor 7e also functions as a touch panel and is configured to receive input operations from the operator. 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). 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.

[0027] <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.

[0028] 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 2b, and the other ends are attached to upper and lower link arms 13 located at the bottom of the seedling planting section 3.

[0029] 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.

[0030] 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.

[0031] As shown in Figure 1, the seedling planting unit 3 includes a seedling stand 3a for propping up soil-covered mat-shaped seedlings (hereinafter referred to as "seedling mats"), a planting device 3b located behind and below the seedling stand 3a, a center float 3c located below the planting device 3b, and side floats 3d positioned to the left and right of the center float 3c.

[0032] 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.

[0033] 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.

[0034] <Configuration of the fertilizer application device> Figure 2 is a schematic left side view of the fertilizer application device 4 shown in Figure 1, and Figure 3 is a perspective view of the main parts of the same device. As shown in Figure 2, the fertilizer application device 4 includes an air chamber 4a extending in the left-right direction of the machine, a blower 4b that pumps 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 4c, 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.

[0035] The blower 4b is equipped with an intake duct 4g, and when a blower motor (not shown) is driven, air drawn in through the intake duct 4g is supplied into the air chamber 4a. The air supplied into the air chamber 4a is then pumped to the right and supplied into each fertilizer hose 4f through each connecting pipe 4e.

[0036] 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 4e is supplied to the field by passing through the fertilizer hose 4f with air supplied from the front air chamber 4a.

[0037] Here, the electric motor 4m that rotates the dispensing shaft 4j is controlled by the control device C in terms of rotation speed (rpm) and rotation direction (forward or reverse). In other words, the amount of fertilizer dispensed by the dispensing device 4d is determined according to the rotation speed of the dispensing roll 4i, so the control device C can control the amount of fertilizer dispensed by the fertilizer dispenser 4 by controlling the rotation speed of the electric 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 rotation speed of the electric motor 4m (in other words, the number of rotations per unit time) to become the target rotation speed (hereinafter referred to as the target rotation speed V) calculated based on the set target amount of fertilizer dispensed (hereinafter referred to as the target amount of fertilizer dispensed). In other words, the electric motor 4m is automatically controlled so that the target rotation speed increases as the set target amount of fertilizer dispensed increases, and decreases as the set target amount of fertilizer dispensed decreases. Although not shown in the diagram, the rotational speed (rpm) of the electric motor 4m is detected by a rotational speed detection sensor, and the control device C is configured to acquire information regarding the detected value.

[0038] Furthermore, as shown in Figure 3, a coupling 4k is interposed between the output shaft of the electric motor 4m and the dispensing shaft 4j. This coupling allows for misalignment between the two, thereby preventing overload and enabling stable fertilization.

[0039] <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 2, 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 vehicle's latitude and longitude. The position information measured by the positioning device 5 is transmitted to the control device C (see Figure 5).

[0040] <Configuration of the soil information acquisition unit> The soil information acquisition unit J measures the soil in the field to determine the soil's fertility (i.e., The system acquires information indicating the ease with which crops can grow (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 fertility. The topsoil depth sensor j1 is an ultrasonic sensor installed at the front of the vehicle body 2, and it is possible to 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 is possible to measure the soil fertility by passing a weak electric 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 indicator of soil 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.

[0041] <Configuration of a mobile information terminal> The portable information terminal 6 is an information processing device separate from the vehicle body 2, and is a portable information processing device that can be carried by the operator, such as a smartphone or tablet. This portable information terminal 6 has a display unit 6a and an operation unit 6b on the outside of the device, and has a map data acquisition unit 6c that acquires map data for creating a fertilization map Dh, a fertilization map creation instruction unit 6d that transmits the acquired map data to the control device C (described later) and instructs the creation of the fertilization map Dh, and a communication unit 6f on the inside of the device (see Figure 4). Details of the fertilization map Dh will be described later.

[0042] 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., and receives various operations from the operator. When the operator performs a predetermined operation on the operation unit 6b, the map data acquisition unit 6c acquires the map data from the external server SV, and the fertilization map creation instruction unit 6d transmits the acquired map data to the control device C (described later) and also transmits a control signal instructing the creation of the fertilization map Dh.

[0043] Furthermore, the portable information terminal 6 is connected to the network NW via the communication unit 6f, enabling it to send and receive various information wirelessly with the work vehicle 1 and the external server SV. 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.

[0044] <Fertilization Map> Figure 4 is a conceptual diagram of the data structure of the fertilization map Dh. The fertilization map Dh is data in which the target amount of fertilizer is set for each plot of field, and consists of at least information indicating the area of ​​the field, location information for each point within the area of ​​the field, and information on the target amount of fertilizer set for each plot of field.

[0045] More specifically, as shown in Figure 4, the fertilization map Dh allows any point P within the roughly rectangular field area A, which represents the area of ​​the field, to be identified by its latitude and longitude and corresponding two-dimensional coordinates X and Y (in the example shown, X=210, Y=10). In other words, it is configured so that point P within field area A can be identified from the positional information indicating the latitude and longitude of the machine located in the field.

[0046] Furthermore, the field area R is divided into rectangular sections K of predetermined size in a matrix. The fertilization map Dh is composed of information for each section K, including the section number to identify the section, the range of the section on two-dimensional coordinates (range X, range Y), and the target fertilizer amount set for that section K. In the illustrated example, section K1 is section number 31, its range is X coordinate: 200~300, Y coordinate: 0~100, and the target fertilizer amount is 30. The target fertilizer amount is set as a numerical value indicating, for example, the number of kilograms of fertilizer per 10 ares.

[0047] With this data structure, the control device C can identify the section K to which any point in the field being worked on belongs, based on the location information of that point, by referring to the fertilization map Dh. It can then obtain information on the target fertilization amount set for that identified section and control the fertilization amount of the fertilizer applicator 4 to match the obtained target fertilization amount. This makes it possible to set the fertilization amount for each section K of the field, taking into account factors such as soil fertility. In other words, each section of the fertilization plan map Dh has a target fertilization amount set, which is the amount of fertilizer to be applied to the corresponding area of ​​the field.

[0048] <Control device configuration> Figure 5 is a block diagram showing the configuration of the control system, including the control device C, of ​​the work vehicle 1. 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.

[0049] As shown in Figure 5, the control device C comprises an output processing unit c1, a communication processing unit c2, an input processing unit c3, a travel control unit c4, an information storage unit c5, a work travel management unit c6, a fertilizer map management unit c7, and a fertilizer device control unit c8, which are configured to send and receive information from each other via a communication bus BA.

[0050] 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.

[0051] 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.

[0052] 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 the positioning device 5, the driving system detection sensor group S1 including the steering angle detection means, the seedling planting unit 3, the rotation speed detection sensor of the fertilizer application device 4, and the work system detection sensor group S2 including the soil information acquisition unit J.

[0053] 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.

[0054] 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. The automatic driving control device c41 configured in this way calculates the deviation using the deviation calculation unit c413, calculates an appropriate steering angle of the steering wheel 7b for the work vehicle 1 to travel along the target driving path R based on the calculated deviation, and controls the steering actuator to achieve the calculated steering angle, thereby enabling the work vehicle 1 to automatically travel along the target driving path L (described later).

[0055] 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 confirmation by the worker. This allows the worker to analyze the field and the work.

[0056] 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.

[0057] Route information storage unit c52 is a memory area for storing route information. Here, route information includes, For example, it includes information about the travel route of the work vehicle 1, such as position information indicating the target travel route L described later.

[0058] The work information storage unit c53 is a memory area for storing work information. Here, the work information includes: For example, it includes information about the work performed by work vehicle 1, such as the work width W pre-set by the worker, the type of work (fertilization, planting, etc.), acquired data maps, and created fertilization maps Dh.

[0059] The work travel management unit c6 is a program that manages the work travel of the work vehicle 1 (i.e., automatic travel for fertilization work), and includes a route calculation unit c61 that calculates the travel route during work travel, and a work travel execution unit c62 that determines the operation of the work vehicle 1 during work travel.

[0060] The route calculation unit c61 calculates the target travel route R based on field information and work information, etc. Figure 6 is an explanatory diagram illustrating the target travel path R of the work vehicle 1. Here, the target travel path R refers to the travel path that the work vehicle 1 aims for during automated driving, and the information indicating the target travel path R includes, for example, position information indicating the trajectory of the target travel path R. The route calculation unit c61 calculates the target travel path R using, for example, the following design procedure.

[0061] First, field information is acquired, and the field area A to be worked on is divided into a headland area A1 where work is performed by traveling in a circular pattern, and a straight-line area A2 where work is performed by traveling in a straight line. Here, the headland area A1 is set as a frame-shaped area based on a predetermined working width W, and the rectangular straight-line area A2 is set inside this headland area A1. In the illustrated example, field area A is the area inside the field ridges.

[0062] Next, a headland travel path that travels in a circular manner within the headland travel area A1 is designed, followed by the design of multiple straight travel paths that travel in a straight line within the straight travel area A2, and the starting point P1 and ending point P2 of the work travel in the straight travel area A2 are determined. Here, in order to prevent work from being performed on the same point by overlapping the straight travel paths, a distance approximately equal to the work width W is provided between them.

[0063] Next, non-working routes are designed, which are routes that do not involve any work during travel, such as moving between straight travel routes in a single continuous line, turning between straight travel routes, and moving from a straight travel route to a headland travel route. The information indicating the target travel route R calculated in this manner is stored in the route information storage unit c52. As a result, the automatic travel control unit c41 can automatically travel within the field by appropriately referring to the information indicating the target travel route R stored in the route information storage unit c52.

[0064] Returning to Figure 5, the work travel execution unit c62 determines the operation of the work vehicle 1 during work travel. The details of the processing of this work travel execution unit c62 will be described later.

[0065] The fertilization map management unit c7 is a program that performs the function of managing the fertilization map Dh. The fertilization map management unit c7 includes a fertilization map creation unit c71 that creates a fertilization map Dh based on acquired map data, and a reliability setting unit c71 that sets a reliability level for each created fertilization map Dh.

[0066] Here, the map data includes, at a minimum, map information including the location information of the field, and data related to the amount of fertilizer applied, linked to the location information of each point in the field. Various types of data can be used to calculate the target amount of fertilizer applied to each section of the field using a predetermined algorithm. Examples of map data that can be used include growth map data that records the growth rate of crops in the field in the previous year for each location, weed map data that records the growth rate of weeds in the field in the previous year for each location, soil fertility map data that records the soil fertility for each location in the field, and soil sensing data that records the measurement information of the soil information acquisition unit J during the previous work run for each location in the field.

[0067] When the fertilization map creation unit c71 receives a control signal from the portable information terminal 6 instructing the creation of a fertilization map Dh, along with map data, it creates a fertilization map Dh from the acquired map data using a predetermined algorithm and stores the created fertilization map Dh in the work information storage unit c53. A separate fertilization map Dh is created for each type of acquired map data. The fertilization map creation unit c71 may also be configured to create a fertilization map Dh by obtaining map data from an external server SV when the operator performs a predetermined operation on the monitor 7e.

[0068] The reliability setting unit c72 displays a predetermined setting screen on the display unit 6a or monitor 7e of the portable information terminal 6 and accepts input operations from the operator via the operation unit 6b or monitor 7e of the portable information terminal 6, thereby performing the function of setting a reliability value for each fertilization map Dh created by the fertilization map creation unit c71. The set reliability value for each fertilization map Dh is stored in the work information storage unit c53. Here, reliability is a numerical value indicating the reliability of the fertilization map Dh, and is represented by a number (integer) from 1 to 5, for example, with a higher number indicating higher data reliability. The operator can evaluate the reliability of the data for each fertilization map Dh and set any value from 1 to 5 as the reliability value. Furthermore, using a similar procedure, the value of the weighting coefficient, which serves as an evaluation index for the fertilization map Dh when creating the composite fertilization map Dg described later, can also be set for the same fertilization map Dh. The weighting coefficient can be set by a number (integer) from 1 to 10, for example.

[0069] The fertilizer application control unit c81 transmits a control signal to the fertilizer application device 4 that includes a control amount for controlling the amount of fertilizer applied. This is a program that controls the rotational speed (in other words, the number of rotations per unit time) of the electric motor 4m that rotates the dispensing shaft 4j. As a result, the control device C can control the amount of fertilizer applied by the fertilizer application device 4 during operation.

[0070] The fertilizer application amount determination unit c82 is a program capable of executing multiple fertilization modes with different methods for determining the fertilizer application amount. By passing information on the fertilizer application amount (control amount) of the fertilizer application device 4 to the fertilizer application amount control unit c81, it performs the function of determining the fertilizer application amount of the fertilizer application device 4 during fertilization work.

[0071] The fertilization mode execution unit c82 includes two executable fertilization modes (programs): fertilization map utilization mode c821 and soil information utilization mode c822. Each mode is described below.

[0072] The fertilization map-based fertilization mode c821 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 (or the combined fertilization map Dg). Details on how the amount of fertilizer applied by the fertilizer applicator 4 is determined while the fertilization map-based fertilization mode c821 is running (i.e., while the fertilization map-based fertilization mode is selected) will be described later.

[0073] This fertilization map-based fertilization mode c821 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 (or the combined fertilization map Dg), compares the position information on the fertilization map Dh (or the combined fertilization map Dg) with the position information acquired from the positioning device 5, and identifies a section K on the fertilization map Dh (or the combined fertilization map Dg). Next, it acquires information on the target fertilization amount set for the identified section K, thereby determining the target fertilization amount of the fertilization device 4. Accordingly, the target fertilization amount (control amount) of the fertilization amount control unit c81 is determined. By optimizing the fertilization amount of the fertilization device based on the combined fertilization map Dg, it is possible to prevent fertilizer leakage due to fertilizer depletion.

[0074] The soil information utilization fertilization mode c822 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 the soil information utilization fertilization mode c822 is running (i.e., while the soil information utilization fertilization mode is selected), the control device C acquires soil information from the soil information acquisition unit J at predetermined time intervals and calculates, for example, the amount using the following formula (1).

[0075] (Formula 1) Fertilizer amount = Standard fertilizer amount × (100-fertilization reduction rate (%)) / 100 However, the amount of fertilizer applied is the basic amount of fertilizer to be calculated in advance by the worker, and the fertilizer reduction rate is determined by calculating a growth evaluation value (an evaluation value indicating soil fertility) using topsoil depth and SFV value from soil information acquired by the soil information acquisition unit J, and then determining the fertilizer reduction rate (%) based on the calculated growth evaluation value.

[0076] <Processing procedure for the work vehicle execution unit> Next, the processing of the work travel execution unit c62 will be explained with reference to Figures 7 to 10. Figure 7 is a flowchart showing the processing of the work drive execution unit during work drive, Figure 8 is a graph showing an example of the change in rotation speed of the 4m electric motor when fertilizer clogging occurs, Figure 9 is an explanatory diagram explaining the operation of the work vehicle during work drive, and Figure 10 is an explanatory diagram of the same.

[0077] As shown in Figure 7, when the operation is started by the operator performing a predetermined operation on the operator's portable information terminal 6, the operation execution unit c62 acquires information regarding the detected value of the rotation speed detection sensor of the electric motor 4m at predetermined time intervals and determines whether the rotation speed of the electric motor 4m is below the set lower limit rotation speed (step #101). Here, the set lower limit rotation speed is the lower limit of the rotation speed of the electric motor 4m at which it can be determined that the fertilizer applicator 4 is operating normally, and therefore, a value smaller than the target rotation speed V is set in advance by the operator (for example, 5 rpm). In other words, when the rotation speed of the electric motor 4m falls below the set lower limit rotation speed during operation, it can be determined that the fertilizer applicator 4 is not operating normally due to fertilizer clogging or the like.

[0078] When the rotational speed of the electric motor 4m is greater than the set lower limit rotational speed (Y in step #101), the fertilizer applicator 4 is determined to be operating normally. Therefore, unless there is an instruction to end the work via the operator's portable information terminal 6 (N in step #111), the applicator continues to operate and returns to step #101. If an instruction to end the work is given (Y in step #111), the applicator stops operating (step #112) and the work is completed.

[0079] When the rotation speed of the electric motor 4m is below the set lower limit rotation speed (Y in step #101), it can be determined that the fertilizer applicator 4 is not operating normally due to factors such as fertilizer clogging. Therefore, the work travel execution unit c62 records the current position of the machine using position information acquired from the positioning device 5 (step #102), and then sends a control command to the fertilizer amount control unit c81 to intermittently drive the fertilizer applicator 4, and drives the fertilizer applicator 4 intermittently (step #103). Now, with reference to Figure 8, the intermittent driving of the fertilizer applicator 4 will be explained.

[0080] Figure 8 shows an example of the changes in the rotational speed V (detected value) of the electric motor 4m during operation, as shown in graphs g1 to g4. The vertical axis represents the rotational speed V of the electric motor 4m, and the horizontal axis represents time t. In Figure 8, time t1 is the time when fertilizer clogging occurred in the fertilizer applicator 4, time t2 is the time when intermittent driving started, time t3 is the time when intermittent driving ended, time t4 is the time when a predetermined set time has elapsed since the end of intermittent driving, and time t5 is the time when operation was stopped. Furthermore, graph g1 shows the changes in rotational speed V when the fertilizer applicator 4 is operating normally, graph g2 shows the changes in rotational speed V during intermittent driving, graph g3 shows the changes in rotational speed V when the fertilizer clogging was resolved by intermittent driving, and graph g4 shows the changes in rotational speed V when the fertilizer clogging was not resolved.

[0081] Intermittent drive is a driving method in which the rotation of the electric motor 4m is performed intermittently, and the fertilizer applicator 4 is controlled to repeat the driving and stopping of the electric motor 4m in a predetermined cycle (for example, 2 seconds of stopping and 2 seconds of driving, totaling 4 seconds) for a predetermined time T1 (for example, 10 seconds). This effectively eliminates fertilizer clogging.

[0082] After a predetermined time T1 has elapsed since the start of intermittent driving and the intermittent driving has ended, after a predetermined set time T2 (for example, 2 seconds), information regarding the detected value of the rotation speed detection sensor is acquired again, and it is determined whether the rotation speed of the electric motor 4m is below the set lower limit rotation speed (step #104). If it is determined that the rotation speed of the electric motor 4m is greater than the set lower limit rotation speed (N in step #104), it can be determined that the fertilizer blockage has been resolved, and the process proceeds to step #111. In this way, during work travel, it is determined whether the rotation speed of the electric motor 4m is below the set lower limit rotation speed, and when it is below the set lower limit rotation speed, the electric motor 4m is driven intermittently, thereby preventing the electric motor 4m from stopping due to fertilizer blockage, and as a result, leakage of fertilizer in the work area within the field can be appropriately prevented.

[0083] On the other hand, if it is determined that the rotation speed of the electric motor 4m is below the set lower limit rotation speed (Y in step #104), it can be determined that the fertilizer blockage (or other abnormality) has not been resolved by intermittent driving. Therefore, the work travel execution unit c62 sends a control command to the travel control unit c4 and the fertilizer application device control unit c8 to stop the work travel, and stops the work travel of the work vehicle 1 (step #105). At this time, the abnormality is notified to the operator by a warning output (alarm sound, etc.). Subsequently, after recording the current position of the machine using the position information acquired from the positioning device 5 (step #106), the non-spreading section is calculated, and information regarding the calculated non-spreading section is visually displayed on the monitor 7e or the display unit 6a of the portable information terminal 6 (step #107).

[0084] Now, let's refer to Figure 9 and explain the undispersed interval U. The non-spreading section U is, in detail, the area representing the spread section from the occurrence of fertilizer clogging (or other abnormality) until the operation is stopped, indicating the section where fertilizer could not be spread properly. That is, as shown in Figure 9, the non-spreading section U can be derived as a roughly rectangular area in plan view from the work width W (the work width for fertilization) and the distance L (the difference between the position of the machine recorded in step #102 and the position of the machine recorded in step #106) traveled by the work vehicle from the occurrence of fertilizer clogging until it stops. The control device C visually displays the information regarding the calculated non-spreading section on the monitor 7e or the display unit 6a of the portable information terminal 6, so that the operator can understand the section where fertilizer could not be spread properly, and by applying additional fertilizer to that section, it is possible to appropriately prevent fertilizer leakage in the work area within the field.

[0085] Next, once the operator has completed maintenance work on the fertilizer applicator 4 and has given the instruction to resume operation via a predetermined operation on the operator's portable information terminal 6 (step #108, Y), the operation execution unit c62 transmits a control command to the operation control unit c4 and the fertilizer applicator control unit c8. As shown in Figure 10, the machine automatically reverses to the point recorded in step #3, i.e., the point where an abnormality such as fertilizer clogging occurred (step #109), and then resumes operation (step #110). This reduces the workload on the operator while allowing fertilizer to be applied to the unapplied section. This further improves the prevention of missed fertilizer application within the work area of ​​the field. If no instruction is given to resume work (N in step #108), the work will be terminated.

[0086] <Method for determining the amount of fertilizer applied by a fertilizer application device> Next, we will explain how the amount of fertilizer applied by the fertilizer application device 4 is determined when the fertilizer application mode using a fertilizer map is selected. When the fertilizer application mode using a fertilizer map is selected, the fertilizer map selection process is executed to determine which fertilizer map Dh to be used. Figure 11 is a flowchart showing the flow of the fertilizer map selection process, and Figure 12 is an explanatory diagram for explaining how to create a composite fertilizer map Dg.

[0087] When the fertilization map selection process is executed, as shown in Figure 11, the control device C (fertilization map utilization fertilization mode c821) obtains (references) the confidence level of each fertilization map Dh stored in the work information storage unit c53 (step #201). Subsequently, fertilization maps Dh with a confidence level lower than a predetermined value (for example, 2 or less) are excluded from the selection candidates (step #202).

[0088] Next, a list of candidate fertilization maps Dh is displayed on the display unit 6a, and the operator selects the fertilization map to be used for the current operation from the candidate fertilization maps Dh by performing a predetermined operation (step #203). When only one fertilization map Dh is selected by the operator (N in step #204), fertilization is performed based on the selected fertilization map Dh (step #205).

[0089] On the other hand, when there are two or more selected fertilization maps Dh, the control device C uses the fertilization map creation unit c71 to create a composite fertilization map Dg by weighting and averaging the fertilization amounts for each section of the multiple selected fertilization maps Dh (steps #206 to #207), and fertilization is carried out based on the created composite fertilization map Dg (step #208).

[0090] Specifically, as shown in Figure 12, based on the weighting coefficients set for each of the multiple fertilization maps Dh, the target fertilization amount for each plot K in the field is calculated by weighting and averaging, thereby creating a composite fertilization map Dg.

[0091] <About the fertilizer application rate adjustment mechanism> The work vehicle 1 may be equipped with a fertilizer application rate adjustment mechanism that adjusts the amount of fertilizer applied by the fertilizer application device 4 based on the amount of fertilizer actually consumed during operation. Specifically, a height detection sensor for detecting the height of the top surface of the fertilizer is provided in the fertilizer hopper 4c, and the control device C is configured to be able to acquire the measurement information from the height detection sensor. Furthermore, the control device C is configured to be able to calculate the weight of the amount of fertilizer actually consumed from the number of rotations of the fertilizer application device 4 and the change in the height of the top surface of the fertilizer (for example, by calculating the consumed volume from the area of ​​the top surface of the fertilizer × the decrease in height, and then multiplying the consumed volume by the weight of fertilizer per unit volume). Furthermore, the control device C may be configured to calculate the actual weight (kg) of fertilizer consumed per unit area (for example, 1a) from the working area in the field (for example, calculated from the working width W × travel distance), compare this with the ideal consumption amount (weight of fertilizer) calculated from the target fertilizer application amount, and adjust the amount of fertilizer applied by the fertilizer application device 4 so that the actual weight of fertilizer consumed approaches the ideal consumption amount. In this way, the work vehicle 1 is configured to calculate the actual weight of fertilizer consumed during work travel, thereby preventing fertilizer leakage due to fertilizer depletion.

[0092] <Other> The work vehicle 1 can be configured to memorize the tilt angle and speed of the HST lever and reflect this in the trial fertilizer dispensing operation, thereby improving the accuracy of the fertilizer filling rate and dispensing amount into the roller section installed below the fertilizer tank. This allows for adjustment and visualization of the filling rate within the roller, enabling responses to rising material costs and the spread of lighter organic fertilizers. [Explanation of Symbols]

[0093] 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 4K coupling 4p motor output shaft 4m electric 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 dispenser that rotates a fertilizer dispensing roll using an electric motor, a control device that controls the amount of fertilizer dispensed by the fertilizer dispenser by controlling the rotation speed of the electric motor, and a positioning device that acquires the vehicle's own position, and configured to control the amount of fertilizer dispensed by the fertilizer dispenser by acquiring a target amount of fertilizer set for the section to which the vehicle's position belongs, using a fertilizer map in which the amount of fertilizer dispensed for each section of the field is set based on the vehicle's own position acquired by the positioning device, The control device is configured to acquire detection information from a rotation speed detection sensor that detects the rotation speed of the electric motor, and to intermittently drive the fertilizer applicator for a predetermined time when the rotation speed of the electric motor falls below a set lower limit rotation speed during work travel.

2. The control device is configured to record the machine's position when the rotational speed of the electric motor falls below a set lower limit rotational speed, and further, even after intermittently driving the fertilizer applicator, if the rotational speed falls below the set lower limit rotational speed, it records the machine's position and stops the operation. The work vehicle according to claim 1, characterized in that, after stopping work travel, it calculates an unspreaded section indicating the section in which fertilizer could not be spread properly, based on a preset work width and recorded information on the position of the machine, and displays the calculated unspreaded section.

3. The work vehicle according to claim 2, characterized in that, after stopping work movement and receiving an instruction to resume work, it is configured to automatically reverse to a point where the rotation speed of the electric motor falls below a set lower limit rotation speed by referring to the recorded information regarding the position of the machine, and then resume work movement.

4. The control device is configured to store information on multiple fertilization maps linked to information on a set value indicating the reliability of each fertilization map, and before the work vehicle is driven, it excludes fertilization maps from the multiple fertilization maps whose reliability is less than or equal to a predetermined value from the selection candidates, and has the operator select a fertilization map to be used, and if there are multiple selected fertilization maps, it creates a composite fertilization map by weighting the amount of fertilizer applied to each section of the multiple selected fertilization maps, and fertilization is performed based on the created composite fertilization map, as described in claim 1.

5. The work vehicle according to claim 1, further comprising a height detection sensor for detecting the height of the top surface of fertilizer stored in the fertilizer applicator, wherein the control device is configured to acquire the measurement information from the height detection sensor, and the control device is configured to calculate the actual weight of fertilizer consumed during operation from the number of rotations of the fertilizer applicator and the change in the top surface height.

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