Work vehicle

Abstract

To suppress an occurrence of electricity run-out during automatic travelling as compared to a conventional technology in which a travelling route is registered beforehand.SOLUTION: On the basis of a measurement result of an electric power measurement unit (202) when work is performed while a work vehicle is travelling in a manual travelling mode, a control part (300) controls a power consumption value of an electric motor (4,M0) and a change rate of electric power in an automatic travelling mode so that work can be performed by automatic travelling with work contents in the manual travelling according to an actual state of a farm field, and an occurrence of electricity run-out in the automatic travelling can be suppressed as compared with a conventional technology in which a travelling route is registered beforehand.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle, and more particularly to a work vehicle in which a traveling device and a work implement are electrically driven. [Background technology]

[0002] A technology is known for an autonomously driven work vehicle that has a set travel route and automatically creates a travel route that moves to a pre-set charging station depending on the battery charge (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-27456 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology described in Patent Document 1, the driving route and the locations of charging stations are registered in advance. Therefore, when traveling along a set route, it is not possible to make detailed adjustments to the state of the field as in manned driving, and it is difficult to respond to load fluctuations that depend on the field conditions, such as localized soft ground. Therefore, there is a concern that the battery may run out of power earlier than expected, which is known as a lack of power.

[0005] The present invention has as its technical objective the prevention of power shortages occurring during automatic driving, compared to conventional technologies in which driving routes are registered in advance. [Means for solving the problem]

[0006] The above-mentioned problems of the present invention are solved by the following means. The invention described in claim 1 includes a vehicle body (1a), a work implement (18, 7, 252) supported by the vehicle body (1a) and operating during work in a field, an electric motor (4, M0) that drives a traveling device (2, 3) of the vehicle body (1a) and the work implement (18, 7, 252), a power meter (202) that measures the power consumption value and the rate of change of power in the electric motor (4, M0), and predetermined work information of the work implement (18, 7, 252) while the vehicle body (1a) is automatically traveling along a predetermined traveling route (401). and a control unit (300) that switches between an automatic driving mode in which the work implement (18, 7, 252) is controlled based on a measurement result of the power meter (202) when the vehicle body (1a) is driven while working in the manual driving mode, and a manual driving mode in which the work implement (18, 7, 252) is controlled while the vehicle body (1a) is driven in accordance with the operation of the operator, and the control unit (300) that controls the power consumption value and the rate of change of power of the electric motor (4, M0) in the automatic driving mode based on the measurement result of the power meter (202) when working in the manual driving mode while driving.

[0007] The invention described in claim 2 is the work vehicle described in claim 1, characterized in that it comprises: a work machine (18, 7) having a cutting device (18) that cuts grass in the field; a storage section (7) supported on the vehicle body (1a) and that stores grass cut by the cutting device (18), the storage section (7) being movable between a storage position where grass can be stored and a discharge position where the grass can be discharged; and a control section (300) that automatically drives the vehicle body (1a) based on driving information including information on the driving speed of the vehicle body (1a) and controls the storage section (7) based on work machine information including information on grass discharge positions (408, 409).

[0008] The invention described in claim 3 is the work vehicle described in claim 1, characterized in that, in the automatic driving mode, the control unit (300) reduces the driving speed so that the threshold value is not reached when at least one of the power consumption value and the rate of change reaches a predetermined threshold value based on the measurement results of the power measuring device (202).

[0009] The invention described in claim 4 is the work vehicle described in claim 1, characterized in that it comprises: a battery (5a) supported by the vehicle body (1a) and having power stored in the electric motor (4, M0); and the control unit (300) that, in the automatic traveling mode, based on traveling information including a charging position (411) in the field where the battery (5a) can be charged, sets a route for interrupting work and automatically traveling to the charging position (411) to charge the battery (5a) when the remaining charge of the battery (5a) falls below a predetermined value, and after charging is completed, aligns the traveling direction of the vehicle body (1a) with the traveling direction when work was interrupted, to set a route for automatically traveling to the position where work was interrupted.

[0010] The invention described in claim 5 is the work vehicle described in claim 4, characterized in that it comprises a power receiver (502) that is arranged at the charging position (411) and can receive power from an optical wireless power supply device (503) that transmits power by light, the power receiver (502) being supported on the vehicle body (1a), and the control unit (300) that performs work while charging within a range where the power receiver (502) can receive power from the optical wireless power supply device (503). [Effects of the Invention]

[0011] According to the invention of claim 1, the control unit (300) controls the power consumption value and the rate of change of power of the electric motor (4, M0) in the automatic driving mode based on the measurement result of the power meter (202) when working while driving in the manual driving mode, so that work can be performed in the automatic driving mode with the work content during manual driving that corresponds to the actual situation of the field, and it is possible to suppress the occurrence of power shortage during the automatic driving compared to the conventional technology in which the driving route is registered in advance.

[0012] According to the invention described in claim 2, in addition to the effects of the invention described in claim 1, by automatically driving at the driving speed included in the driving information and controlling the storage section (7) using the grass discharge position (408, 409) included in the work machine information, it is possible to perform work during automatic driving with the work content during manual driving that corresponds to the actual situation in the field.

[0013] According to the invention of claim 3, in addition to the effect of the invention of claim 1, when at least one of the power consumption value and the rate of change reaches a threshold, the traveling speed is reduced so that the threshold is not reached, thereby preventing excessive load on the work vehicle.

[0014] According to the invention of claim 4, in addition to the effect of the invention of claim 1, when the remaining charge of the battery (5a) falls below a predetermined value, work can be interrupted and the battery (5a) can be automatically charged. Furthermore, after charging is completed, the vehicle body (1a) is automatically driven to the position where work was interrupted by aligning its traveling direction with the traveling direction when work was interrupted, allowing work to be smoothly resumed.

[0015] According to the invention of claim 5, in addition to the effect of the invention of claim 4, charging is possible wirelessly, and work can be performed while charging within the range where the receiver (502) can receive power from the optical wireless power supply device (503), thereby improving work efficiency. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment. [Figure 2] FIG. 2 is a functional block diagram of the control unit according to the embodiment. [Figure 3] FIG. 3 is an explanatory diagram of an example of a travel route according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram of an example in which charging is performed during automatic driving. [Figure 5] FIG. 5 is an explanatory diagram of a work vehicle during charging. [Figure 6] FIG. 6 is an explanatory diagram of a flowchart of the automatic driving mode processing of the tractor according to the embodiment. [Figure 7] FIG. 7 is an explanatory diagram of a flowchart of the automatic driving mode processing of the tractor according to the embodiment, and is a continuation of FIG. [Figure 8] FIG. 8 is an explanatory diagram of a work vehicle according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] FIG. 1 is an explanatory diagram of a tractor as an example of a work vehicle according to an embodiment. In Figure 1, a tractor 1, which is an example of a work vehicle of the present invention, is equipped with front wheels 2, 2 and rear wheels 3, 3 at the front and rear of a traveling body (an example of a vehicle main body) 1a. A traveling motor 4, which is an example of a first electric motor, is mounted below a driver's seat 8 at the rear of the traveling body 1a. The rotational power of the traveling motor 4 is appropriately reduced by a speed change device in a transmission case (not shown) and is configured to be transmitted to the front wheels 2, 2 and rear wheels 3, 3. In this specification, the left and right sides of the tractor 1 when viewed in the forward direction are referred to as the left and right sides, respectively, and the forward direction is referred to as the front side, and the backward direction is referred to as the rear side.

[0018] A container 7, which is an example of a work machine and an example of a storage section, is supported at the rear of the body of the tractor 1. Cut grass is stored in the container 7. Note that, instead of the container 7, a work machine such as a tiller that tills the ground (field) behind the tractor 1 can be attached to the rear of the tractor 1. A grass collector (not shown) is disposed at the front of the container 7. Power is transmitted to the grass collector via a PTO shaft (rear PTO shaft) (not shown). The grass collector sends (transports) the cut grass into the container 7. Drive is transmitted to the PTO shaft in this embodiment from a PTO motor M0, which is an example of a second electric motor, via a first clutch or the like.

[0019] In the tractor 1 of the embodiment, a lawnmower 18, which is an example of a work machine and an example of a mower, is supported between the front wheels 2 and rear wheels 3. The lawnmower 18 performs mowing work by mowing grass (lawn) in a field. Power is transmitted to the lawnmower 18 via a second PTO shaft (mid-PTO shaft) and a second clutch (not shown). The second PTO shaft is driven by a PTO motor M0, but a separate motor dedicated to the second PTO shaft can also be installed. The lawnmower 18 of the embodiment can be raised and lowered, and its height can be adjusted using a lifting cylinder (not shown), to prevent contact with the road surface when traveling on the road and to adjust its height relative to the field.

[0020] A driver's seat (operating seat) 8 is disposed at the top of the traveling vehicle body 1a, and a steering wheel 10 is disposed in front of the driver's seat 8. Also disposed in front of the driver's seat 8 are a display panel (meter panel) for a speedometer (not shown) and various operation switches (not shown). Disposed below and in front of the driver's seat 8 are driving operation devices such as a brake pedal 12 and an accelerator pedal 13 having a forward pedal and a reverse pedal.

[0021] In Figure 1, lift arms 15, 15 are pivotally mounted to the rear of the traveling vehicle body 1a. Lift rods (not shown) are interposed and connected between the lift arms 15, 15 and lower links 16, 16. A container 7 is attached to the lift arms 15 and the lower links 16, but instead of the container 7, a work machine such as a tiller can be attached.

[0022] The lift arms 15 are driven by hydraulic cylinders (not shown). When the hydraulic pressure in the hydraulic cylinders increases and the lift arms 15, 15 are rotated upward, the work machine (container 7) is raised via the lift rod, lower link 16, etc. When the hydraulic oil is discharged and the hydraulic pressure decreases, the lift arms 15, 15 are lowered. Therefore, when the grass collected in the container 7 is to be discharged, the lift arms 15 are raised, the rear end of the container 7 is turned downward, and the grass is discharged from the rear end. The working machines that can be attached to the rear of the traveling vehicle body 1a include rotary tillers for agricultural work, plows, seed sowing machines, seedling transplanters, fertilizer spreaders, chemical sprayers, and the like.

[0023] (Explanation of the control unit of Tractor 1) FIG. 2 is a functional block diagram of the control unit according to the embodiment. The tractor 1 of the embodiment has a control unit 300 that controls each function. The control unit 300 has an input / output interface I / O that performs input and output of signals with the outside. The control unit 300 also has a read-only memory (ROM) that stores programs and information for performing necessary processing. The control unit 300 also has a random access memory (RAM) for temporarily storing necessary data. The control unit 300 also has a central processing unit (CPU) that performs processing according to the programs stored in the ROM or the like. Therefore, the control unit 300 of the embodiment is configured with a small information processing device, a so-called microcomputer. Therefore, the control unit 300 can realize various functions by executing programs stored in the ROM or the like.

[0024] The control unit 300 receives signals from a display panel (not shown), which is an example of an input unit and an example of a display unit, and is configured as a touch panel, as well as from signal input elements such as a positioning device 201, a power meter 202, an automatic driving switch 203, a battery remaining capacity measuring means 204, and various other sensors not shown.

[0025] The positioning device 201 has a GNSS (Global Navigation Satellite System) receiver 201a and an IMU (Inertial Measurement Unit: an example of an inclination measurement component) 201b. The GNSS receiver 201a receives positioning signals from artificial satellites and can measure the current position of the tractor 1. The IMU 201b measures acceleration and angular velocity and can measure the direction (direction of travel) and attitude (left-right tilt and front-back tilt) of the tractor 1. Therefore, by correcting the measurement results of the GNSS receiver 201a with the IMU 201b, the current position can be measured with higher accuracy than when the current position is measured using only the GNSS system.

[0026] The power meter 202 measures the power supplied from the battery 5a (see FIG. 1) inside the hood 5 to the travel motor 4 and the PTO motor M0. As an example, an ammeter can be used as the power meter 202, and an ammeter connected to the output terminal of the battery 5a can be used. In the embodiment, the ammeters are individually arranged according to the power supply system so as to individually measure the power supplied to each of the travel motor 4 and the PTO motor M0, but this is not limited to this. It is also possible to adopt a mode in which the sum of the output currents is measured. Furthermore, although the embodiment measures current, it is also possible to measure voltage, or any parameter linked to power.

[0027] An automatic travel switch 203 is operated to input a signal to start automatic travel. The remaining battery capacity measuring means 204 measures the remaining capacity (remaining amount of power) of the battery 5a.

[0028] The control unit 300 sends control signals to the power supply circuit E as an example of a controlled element, the travel motor 4, the PTO motor M0, the hydraulic cylinder S1, the lifting cylinder S2, the first clutch CL1, the second clutch CL2, etc., to control the running / stopping and running speed of the tractor 1, the operation / stopping and operating speed of the lawn mowing device 18, the raising and lowering of the container 7 attached to the lift arm 15 (rising to the discharge position and lowering to the storage position), and the operation / stopping of the grass collector (an example of a work machine) 252, etc. The control unit 300 can also output a control signal to a display monitor, which is an example of a display unit, to display work information, work status, the vehicle position, and the like.

[0029] The tractor 1 of this embodiment is equipped with a total of two electric motors 4, M0, including the travel motor 4 and the PTO motor M0. The number of electric motors is not limited to two, and it is possible to have a total of three (or more) motors by providing a PTO motor for the lawn mower 18 and one for the grass collector 252, or it is possible to use the power of the travel motor 4 to drive the lawn mower 18 and the grass collector 252, thereby using only one travel motor 4 as the electric motor.

[0030] The positioning means 301 measures the current position of the tractor 1 based on the measurement results of the positioning device 201 . The work information storage means 302 has a travel information storage means 302a and a work implement information storage means 302b, and stores information about work in the field.

[0031] FIG. 3 is an explanatory diagram of an example of a travel route according to the embodiment. The travel information storage means 302a stores information related to the travel of the tractor 1 when working in a field. In Fig. 3, in this embodiment, examples of travel information include information on a travel route 401 and information on travel speed. The information on the travel route 401 also includes a work start position 402, a work end position 403, a turning position 404, and, if there is a switch between forward and reverse (a change of direction), a change of direction position. The information on the travel speed is not limited to a fixed set speed, and the travel speed is stored for each section of a predetermined length along the travel route in the field.

[0032] The work machine information storage means 302b stores information relating to the operation and stoppage of work machines (mower 18 and container 7) when working in the field. In this embodiment, examples of work machine information stored include the coordinates in the field of the raised positions 404a, 406 to which the mower 18 is raised and the lowered positions 404b, 407 to which it is lowered, the coordinates of the discharge start position 408 and discharge end position 409 for discharging grass from the container 7, and the operating speeds of the mower 18 and grass collector 252. The operating speeds of the mower 18 and grass collector 252 are preferably stored for each section of a predetermined length, similar to the traveling speed.

[0033] In this embodiment, the travel route, travel speed, raised and lowered positions of the lawnmower 18, etc. are measured and stored based on the travel route and other information from previous manual travels of the tractor 1. It is also possible to set the turning start position 404a as the raised position and the turning end position 404b as the lowered position. Alternatively, if the lawnmower 18 is manually raised or lowered along the travel route 401 due to localized unevenness in the field, the raised position 406 and lowered position 407 are stored as information. In the embodiment, the work information storage means 302 also stores, as an example of travel information, charging positions 411 where charging devices are located.

[0034] The travel control means 303 controls the travel motor 4 to control the travel (acceleration / deceleration, steering, braking) of the tractor 1. During manual travel (when working in manual travel mode), the travel control means 303 controls the travel motor 4 in accordance with inputs to the accelerator pedal 13, brake pedal 12, steering wheel 10, a speed change lever (not shown), etc., to control the travel (acceleration / deceleration, steering, braking) of the tractor 1. During automatic travel, the travel control means 303 controls the travel motor 4, accelerator pedal 13, brake pedal 12, steering wheel 10, a speed change lever (not shown), etc., based on the measurement results of the positioning means 301 and the travel information and work machine information stored in the work information storage means 302, to control the automatic travel (acceleration / deceleration, steering, braking) of the tractor 1.

[0035] The work machine control means 304 controls the PTO motor M0, hydraulic cylinder S1, lift cylinder S2, and clutches CL1 and CL2 to control the operation of the lawn mower 18, container 7, and grass collector 252. During manual travel, the work machine control means 304 in this embodiment controls the PTO motor M0, etc. in accordance with inputs to work machine switches and work speed setting switches (not shown), to control the operation of the lawn mower 18, container 7, and grass collector 252. During automatic travel, the work machine control means 304 controls the PTO motor M0, etc. based on measurement results from the positioning means 301 and travel information and work machine information stored in the work information storage means 302 to control the operation of the lawn mower 18, container 7, and grass collector 252.

[0036] It is preferable to enhance safety by providing the tractor 1 with a sensor for detecting obstacles, and by having the driving control means 303 stop automatic driving when an obstacle is detected during automatic driving and resume automatic driving when the obstacle is removed. Here, it is preferable that when automatic driving is stopped, the work machine control means 304 control the lawnmower 18 and grass collector 252 to stop until automatic driving resumes, thereby reducing unnecessary power consumption. It is preferable that while an obstacle is detected, a notification means such as a buzzer, lamp, or voice guidance is used to notify those in the vicinity.

[0037] The power measurement means 305 measures the power consumption of the travel motor 4 and the PTO motor M0 based on the measurement results of the power meter 202. Note that in this embodiment, the power measurement means 305 measures the power consumption of the travel motor 4 and the power consumption of the PTO motor M0. The travel control means 303 requests power supply to the travel motor 4 so that the vehicle travels at a target speed according to operation, and therefore, as the travel load increases, the amount of power requested of the travel motor 4 increases to maintain the target speed. Therefore, by monitoring the power consumption of the travel motor 4, it is possible to monitor the load on the travel motor 4. Similarly, the work machine control means 304 requests power supply to the PTO motor M0 so that the work machine (the lawn mower 18 or the grass collector 252) operates at a target operating speed, and therefore, as the work load increases, the amount of power requested of the PTO motor M0 increases. Therefore, by monitoring the power consumption of the PTO motor M0, it is possible to monitor the load on the PTO motor M0. Therefore, the power measurement means 305 of the embodiment also has a function of measuring the load during travel and the load on the work machine through the power consumption.

[0038] The power measurement result storage means 306 stores the measurement results of the power measurement means 305. In this embodiment, the power measurement result storage means 306 stores current consumption values, which are an example of power consumption values ​​measured by the power measurement means 305, and the rate of change of the current consumption values ​​(amount of change per unit time). The power measurement result storage means 306 stores the current consumption values ​​and rate of change at each coordinate in the field along the travel route during manual travel as reference values. The power measurement result storage means 306 also stores the current consumption values ​​and rate of change during automatic travel as work history information. This makes it possible to check the power consumption during automatic travel later. In particular, if power consumption history information is recorded for each section, it becomes possible to check the power consumption when the lawnmower 18 is operating and when it is not operating (while traveling within the field) for each section and area.

[0039] In addition, when working in multiple fields consecutively, the operator can check the past power consumption for each field from the history information of the power measurement results and determine whether the remaining charge in the battery 5a is sufficient to work in the next field without charging, or whether it is better to charge the battery before moving to the next field. Therefore, it can also be used to create work plans.

[0040] The power supply control means 307 controls the power supply circuit E to control the power supply to each part of the tractor 1. During manual travel, the power supply control means 307 supplies power to the travel motor 4, PTO motor M0, etc. in accordance with the operator's manual operation. That is, it supplies power to the travel motor 4 so that the travel speed set by manual operation is achieved. It also supplies power in accordance with the operation to start / stop the lawn mower 18 and grass collector 252. It also supplies operating power to the hydraulic cylinder S1, etc. in accordance with the operation to discharge grass from the container 7.

[0041] In addition, during automatic driving, the power supply control means 307 controls the power supply (current consumption value and rate of change) based on the measurement results from the positioning means 301, the driving information and work equipment information stored in the work information storage means 302, and the reference values ​​for the current consumption value and rate of change stored in the power measurement result storage means 306, so that the current consumption value and rate of change are the reference values ​​depending on the position of the field.

[0042] In the tractor 1 of this embodiment, the power supply control means 307 controls the power supply so that the current consumption value and rate of change are at reference values, but if at least one of the current consumption value and rate of change measured by the power measurement means 305 reaches a predetermined threshold value during power supply, the power supply to the traveling motor 4 is controlled to slow down the traveling speed (the supply current is reduced). In other words, if the load on the traveling motor 4 or PTO motor M0 reaches an upper limit (threshold value) during automatic traveling, the power supply is limited to prevent the load from becoming any more excessive, thereby preventing damage to the traveling motor 4, PTO motor M0, lawnmower 18, grass collector 252, etc.

[0043] The charge control means 308 controls the charging of the battery 5a based on the remaining charge of the battery 5a measured by the battery remaining charge measuring means 204. In this embodiment, the charge control means 308 determines that it is time to charge the battery 5a when the remaining charge of the battery 5a falls below a predetermined value (charge determination value). During manual driving, if the charge control means 308 determines that it is time to charge, it displays a message urging the user to charge. Furthermore, if the charge control means 308 determines that it is time to charge during automatic driving, it controls the travel motor 4 and the like via the travel control means 303, work machine control means 304, and power supply control means 307 to interrupt work and autonomously drive the tractor 1 to a charging position 411 to charge the battery 5a. The charge control means 308 in this embodiment includes work interruption position storage means 308a, charge route creation means 308b, positioning means 308c, and return route creation means 308d.

[0044] FIG. 4 is an explanatory diagram of an example in which charging is performed during automatic driving. The work interruption position storage means 308a stores a work interruption position 421 where work is interrupted when it is determined that it is time to charge during automatic traveling. In Fig. 4, the work interruption position storage means 308a in the embodiment stores the coordinates of the work interruption position 421 in the field and the traveling direction (the direction of the tractor 1) as information on the work interruption position 421.

[0045] The charging path creation means 308b creates charging path 422, which is a travel path from the work interruption position 421 to the charging position 411. In this embodiment, the charging path creation means 308b selects the nearest (shortest) charging position 411 based on the coordinates of the work interruption position 421, and creates charging path 422 from the work interruption position 421 to the charging position 411. In this embodiment, charging path 422 is created so as to pass through unworked areas and not through areas where work has been completed. Note that there is a possibility that weeds have been removed in areas where work has been completed, and if the tractor 1 travels through an area where weeds have been removed, this is not preferable as it may disturb the removed grass. However, if weeds have not been removed or if it is acceptable for the tractor 1 to pass over removed grass, it is also possible to create a path that passes through an area where work has been completed.

[0046] FIG. 5 is an explanatory diagram of a work vehicle during charging. The positioning means 308c aligns the position of a power receiving coil 431 (see FIG. 5) as an example of a power receiver of the tractor 1 with a power transmitting coil 433 as an example of a power transmitter of the charging device 432. The positioning means 308c of the embodiment aligns the position by running the tractor 1 so that the positions match based on the current position of the tractor 1 measured by the positioning means 301 and the pre-registered coordinates of the power transmitting coil 433 of the charging device 432.

[0047] It is also possible to mount a positioning device on the charging device 432, and have the charging device 432 and the tractor 1 communicate with each other, allowing the tractor 1 to acquire information on the current location of the charging device 432 and perform positioning. It is also preferable to have a terminal such as a tablet that remotely controls the tractor 1 display the current location of the tractor 1 and the location of the charging device 432 on a map, making it easier for the worker to check. In addition, in the embodiment, the tractor 1 is charged wirelessly, but this is not limiting. After the tractor 1 stops at the charging position 411, an operator aboard the tractor 1 or an operator waiting at the charging position 411 can connect the charging device 432 and the tractor 1 with a charging cable to charge the tractor 1 via a wired connection.

[0048] Furthermore, in the embodiment, the power receiving coil 431 is installed on the underside of the container 7 at the rear of the tractor 1, but this is not limiting. The power receiving coil 431 can be installed at any position, such as on the underside of the traveling body 1a or in front of the traveling body 1a. It is preferable that the power receiving coil 431 can be used as a power transmitting coil not only when charging the battery 5a but also when supplying power from the battery 5a to the outside in an emergency such as a disaster. Since the coils 431 and 433 are expected to be used in a disaster or outdoors, they are preferably covered with resin or the like so that they can withstand water damage.

[0049] Furthermore, when transmitting power wirelessly using coils 431 and 433, it is preferable to transmit power at a frequency higher than the frequency of the AC power supply, as this increases the efficiency of wireless power transmission. Furthermore, in the embodiment, an example has been given in which one tractor 1 travels in a field, but this is not limiting. In a large field, it is also possible to have a configuration in which multiple tractors 1 travel. In this case, it is preferable that, among the multiple charging devices 432, information on the charging device 432 that is in use is shared with other tractors 1 that are working but not charging.

[0050] After charging is completed, the return path creation means 308d creates a return path 423 (see FIG. 4) that returns from the charging position 411 to the work interruption position 421. In this embodiment, the return path 423 is created so that the approach direction to the work interruption position 421 on the return path 423 matches the traveling direction at the work interruption position 421 when work was interrupted. In the embodiment, the return route 423 is created, but the present invention is not limited to this. It is also possible to reduce the process of creating the return route 423 by traveling in the opposite direction along the charging route 422 to return to the work interruption position.

[0051] (Flowchart explanation) Next, the processing of the tractor 1 according to the embodiment will be described using a flow chart. It should be noted that various processes of the tractor 1 other than those explained in the flowchart are processed in parallel, and detailed explanations and illustrations thereof will be omitted.

[0052] (Explanation of the automatic driving mode processing of Tractor 1) FIG. 6 is an explanatory diagram of a flowchart of the automatic driving mode processing of the tractor according to the embodiment. FIG. 7 is an explanatory diagram of a flowchart of the automatic driving mode processing of the tractor according to the embodiment, and is a continuation of FIG. The processing in FIGS. 6 and 7 is initiated when the tractor 1 is started. In ST1 of Fig. 6, it is determined whether an input operation to start the automatic driving mode has been performed. If the answer is yes (Y), proceed to ST2, and if the answer is no (N), repeat ST1.

[0053] In ST2, work information (travel information and work equipment information) and reference information (reference values ​​for current consumption and rate of change) are read in. Then, the process proceeds to ST3. In ST3, the robot starts automatic travel to the work start position 402. Then, the robot proceeds to ST4. In ST4, it is determined whether or not the tractor 1 has arrived at the work start position 402 based on the current position of the tractor 1 and the coordinate information of the work start position 402. If yes (Y), proceed to ST5, and if no (N), repeat ST4. In ST5, the following steps (1) to (3) are executed, and the process proceeds to ST6. (1) Based on the travel information and reference information, travel begins along the travel route 401 at a travel speed. (2) Lower the lawn mower 18. (3) Activate the lawn mower 18 or grass collector 252.

[0054] In ST6, it is determined whether the lawnmower 18 has reached the raised position 404a, 406. If yes (Y), proceed to ST7, and if no (N), proceed to ST10. In ST7, the following processes (1) and (2) are executed, and the process proceeds to ST8. (1) Raise the lawn mower 18. (2) Stop the lawn mower 18. In ST8, it is determined whether the lawnmower 18 has reached the lowering position 404b, 407. If yes (Y), proceed to ST9; if no (N), repeat ST8. In ST9, the following processes (1) and (2) are executed, and the process returns to ST6. (1) Lower the lawn mower 18. (2) Activate the lawn mower 18.

[0055] In ST10, it is determined whether or not the container 7 has arrived at the grass discharge start position 408. If yes (Y), proceed to ST11, and if no (N), proceed to ST12. In ST11, the container 7 is raised and grass discharge begins. In this embodiment, grass cutting continues even while grass is being discharged, but it is also possible to have a configuration in which the lawn mower 18 or grass collector 252 is stopped. Then, the process returns to ST6. In ST12, it is determined whether or not the container 7 has arrived at the grass discharge end position 409. If yes (Y), proceed to ST13, and if no (N), proceed to ST14 in FIG. In ST13, the container 7 is lowered to finish weed discharge, and the process returns to ST6.

[0056] 7, it is determined whether the remaining capacity of the battery 5a has decreased. If the answer is yes (Y), the process proceeds to ST15, and if the answer is no (N), the process proceeds to ST26. In ST15, the following steps (1) to (4) are executed, and the process proceeds to ST16. (1) The coordinates and traveling direction of the work interruption position 421 are stored. (2) Raise the lawn mower 18. (3) Stop the lawn mower 18 and the grass collector 252. (4) A driving route (charging route 422) to the charging position 411 is created. In ST16, the vehicle starts traveling along charging path 422 to charging position 411. Then, the vehicle proceeds to ST17.

[0057] In ST17, it is determined whether or not the vehicle has arrived at the charging position 411. If yes (Y), the process proceeds to ST18, and if no (N), ST17 is repeated. In ST18, the coils 431 and 433 are aligned, and then the process proceeds to ST19. In ST19, it is determined whether or not alignment of the coils 431 and 433 is complete. If yes (Y), proceed to ST20; if no (N), repeat ST19. In ST20, charging of the battery 5a begins, and the process then proceeds to ST21. In ST21, it is determined whether charging is complete. If yes (Y), proceed to ST22, and if no (N), repeat ST21.

[0058] In ST22, a return route 423 is created based on the coordinates and travel direction of the work interruption position 421. Then, the process proceeds to ST23. In ST23, the vehicle starts traveling from the charging position 411 toward the work interruption position 421 along the return route 423. Then, the vehicle proceeds to ST24. In ST24, it is determined whether or not the work interruption position 421 has been reached. If yes (Y), proceed to ST25, and if no (N), repeat ST24. In ST25, the following steps (1) to (3) are executed, and the process returns to ST6 in FIG. (1) Based on the travel information and reference information, travel begins at the travel speed along the travel route 401 from the work interruption position 421. (2) Lower the lawn mower 18. (3) Activate the lawn mower 18 or grass collector 252.

[0059] In ST26, it is determined whether or not the robot has arrived at the work end position 403. If yes (Y), the process proceeds to ST27, and if no (N), the process returns to ST6 in FIG. In ST27, the following steps (1) to (3) are executed, and the process returns to ST1 in FIG. (1) Stop the travel of the tractor 1. In the embodiment, the travel is stopped, but the present invention is not limited to this, and it is also possible to automatically travel the tractor to a predetermined position outside the field or to travel to the next field. (2) Raise the lawn mower 18. (3) Stop the lawn mower 18 and the grass collector 252.

[0060] In the tractor 1 of the embodiment having the above configuration, power control during automatic driving is performed based on the current consumption value and rate of change during manual driving. Therefore, automatic driving is performed based on the current consumption and rate of change that correspond to the results of operations performed by the operator in accordance with the field conditions during manual driving, that is, the driving and work load during manual driving. With conventional technology that travels along a predetermined travel route, it is difficult to respond to actual conditions in the field only after detecting the load, and it is difficult to predict the load and respond in advance. Therefore, compared to when responding in advance, power consumption is likely to be higher, and there is a concern that the battery will run out of power sooner. In contrast, in the embodiment, the work content that is performed during manual driving can be achieved during automatic driving as is, and automatic driving is possible with detailed operation content that corresponds to the actual situation of the field during manual driving. Therefore, compared to conventional technology, power consumption during automatic driving is reduced, and the occurrence of power shortages is suppressed.

[0061] In addition, in the tractor 1 of the embodiment, the lifting and lowering of the lawn mower 18 and the range of weed removal (from the discharge start position 408 to the discharge end position 409) are also stored as work contents during manual driving, and the same work as during manual driving can be automatically performed during automatic driving. Furthermore, in the tractor 1 of the embodiment, if the remaining charge of the battery 5a becomes low during automatic travel, the tractor 1 suspends work and automatically travels to the charging position 411 to charge. This prevents the tractor 1 from becoming stranded due to a lack of power while working in the field. In particular, in the embodiment, after charging is complete, when the tractor 1 travels along the return route 423 to return to the work interruption position 421, its direction of travel is aligned with the direction of travel at the time of interruption, allowing the tractor 1 to smoothly resume work from the work interruption position 421.

[0062] FIG. 8 is an explanatory diagram of a work vehicle according to another embodiment. In the embodiments shown in FIGS. 1 and 5, the power receiving coil 431 is installed on the underside of the container 7, but the present invention is not limited to this embodiment. As shown in FIG. 8, a solar cell panel 502 as an example of a power receiver can be installed on the top of the ROPS 501. The solar cell panel 502 generates electricity by receiving external light (including sunlight) and can charge the battery 5a. In the embodiment shown in FIG. 8, the solar cell panel 502 is configured so that its light receiving surface faces outward in the horizontal direction and can receive light from all directions of 360 degrees. A configuration capable of receiving light from all directions of 360 degrees can be a configuration in which multiple flat panels are combined, or it is also possible to use a solar cell that can be formed into a curved surface, such as a perovskite solar cell.

[0063] The charging device 432′ is also provided with an irradiator (an example of an optical wireless power supply device) 503 that irradiates light toward the solar cell panel 502 for generating power in the solar cell panel 502. Therefore, the solar cell panel 502 and the irradiator 503 enable wireless transmission of power from the charging device 432′ to the battery 5a using light. The light (an example of electromagnetic waves) output from the irradiator 503 is preferably laser light in terms of reach, but illumination light or microwaves can also be used from the viewpoint of safety.

[0064] Therefore, from a safety standpoint, it is preferable to emit laser light only after it has been confirmed that the solar cell panel 502 is within a range where power can be received. Therefore, when using laser light, it is preferable to provide a sensor camera 504 between the irradiator 503 and the solar cell panel 502 that detects the intrusion of an object, and to control the light emission to be interrupted when the intrusion of an object is detected. Specifically, it is preferable to interrupt the light emission when the sensor camera 504 detects an object within a cylindrical range whose central axis is a straight line connecting the irradiator 503 and the solar cell panel 502. This is because irradiating an object with laser light may ignite or cause a fire, and in the case of a human, this may result in burns or blindness. It is preferable that the range for detecting the intrusion of an object be equal to or greater than the range where power can be received.

[0065] Although the direction of the irradiator 503 can be set to a specific direction, it is preferable to make the direction of light irradiation changeable horizontally or vertically. If the configuration allows light to be irradiated only in a specific direction, charging may be difficult unless the tractor 1 moves to the charging position 411. However, by making the direction of light irradiation changeable, charging is possible anywhere within the range of the light in the field, and there is no need for the tractor 1 to move to the charging position 411. Furthermore, the current position of the tractor 1 is transmitted to the charging device 432' as needed, and the charging device 432' changes the direction of irradiation of the irradiator 503 so that it tracks the tractor 1, allowing the tractor 1 to work while charging. This reduces the number of times work needs to be interrupted to charge, improving work efficiency. Note that in order to accommodate fluctuations in the height of the solar cell panel 502 due to unevenness in the field, it is also possible to increase the height of the solar cell panel 502 or to install a marker on the tractor 1 to indicate the height, and then detect the unevenness of the field from the height of the marker and change the direction of light irradiation up or down.

[0066] 8 illustrates an example in which the solar cell panel 502 is installed on the ROPS 501, but the present invention is not limited to this. It is also possible to install it on the top of the container 7. Alternatively, in a work vehicle with a cabin, it is possible to install it on the upper surface of the cabin ceiling. It is preferable to position the solar cell panel 502 away from the area where the driver is present, but it is also possible to install it on the side of the cabin, etc., after taking safety measures. Furthermore, the solar cell panel 502 is preferably configured to receive light in all directions, but is not limited to this. It may also be configured to receive light from a specific direction, or a flat panel may be configured to be rotatable 360 ​​degrees using a rotation device.

[0067] In the above embodiment, the tractor 1 is explained as being operated by the electric motor 4, M0, but is not limited to this. The present invention can also be applied to a tractor 1 equipped with an electric motor 4, M0 and an internal combustion engine (engine), i.e., a tractor equipped with a so-called hybrid engine. In this case, it is also possible to use a configuration in which the traveling and working equipment are driven by power from the engine, and the electric motor 4, M0 is used as an assist (auxiliary).

[0068] If an engine is installed, it is desirable to provide a function for calculating the amount of CO2 (carbon dioxide) emissions during use. The amount of CO2 emissions can then be displayed on a display panel or a tablet device that can communicate with the tractor 1. At this time, by allowing the user to input the type of fuel used (gasoline, diesel, biofuel, e-fuel, etc.) and its blend ratio, it is also possible to calculate and display the amount of CO2 emissions according to the type of fuel. This makes it possible to disclose the exact amount of CO2 emitted during crop production. For example, if HVO fuel (hydrogenated vegetable oil fuel), which is made by hydrotreating waste oil, or e-fuel, a synthetic liquid fuel made from carbon dioxide and hydrogen, is used, it is possible to convert CO2 emissions to "0" because these are 100% carbon-neutral fuels. It is also possible to reduce the need for manual input by providing a sensor for determining the type of fuel.

[0069] It is also preferable to register and manage the amount of CO2 emitted during the manufacture of materials used during work, such as chemical fertilizers, in association with the amount of CO2 emitted during the travel and operation of the tractor 1. By managing the amount of CO2 emitted for each material used for each field based on the location information measured by the positioning means 301, or by each task such as soil preparation, tilling, and sowing, it becomes possible to disclose the amount of CO2 emitted during the production of each crop harvested in each field. [Explanation of symbols]

[0070] 1...Work vehicle, 1a...Vehicle body, 2,3...Travel gear, 4,M0...Electric motor, 5a…battery, 7...accommodation section, 18...Reaping device, 18,7,252...Work equipment, 202...Power measuring device, 300...control unit, 401...Travel route, 408,409...Discharge position, 411...charging position, 502...Power receiver, 503...Optical wireless power supply device.

Claims

1. A vehicle body (1a), a work implement (18, 7, 252) supported on the vehicle body (1a) and operable during work in a field; an electric motor (4, M0) for driving the traveling device (2, 3) of the vehicle body (1a) and the working machine (18, 7, 252); a power meter (202) for measuring the power consumption value and the rate of change of the power in the electric motor (4, M0); a control unit (300) that switches between an automatic driving mode in which the vehicle body (1a) automatically travels along a predetermined travel route (401) and controls the work machine (18, 7, 252) based on predetermined work information of the work machine (18, 7, 252), and a manual driving mode in which the work machine (18, 7, 252) is controlled while traveling in accordance with an operator's operation, and the control unit (300) controls the power consumption value and the rate of change in power of the electric motor (4, M0) in the automatic driving mode based on a measurement result of the power meter (202) when work is performed while traveling in the manual driving mode; A work vehicle (1) comprising:

2. the work machine (18, 7) having a reaping device (18) that performs work of reaping grass in the field, and a storage section (7) that is supported by the vehicle body (1a) and that stores grass cut by the reaping device (18), the storage section (7) being movable between a storage position where the grass can be stored and a discharge position where the grass can be discharged; the control unit (300) that automatically drives the vehicle body (1a) based on driving information including information on the driving speed of the vehicle body (1a) and controls the storage unit (7) based on work machine information including information on grass discharge positions (408, 409); 2. The work vehicle according to claim 1, further comprising:

3. the control unit (300) that, in the automatic driving mode, when at least one of the power consumption value and the rate of change reaches a predetermined threshold based on the measurement result of the power meter (202), reduces the driving speed so as not to reach the threshold; 2. The work vehicle according to claim 1, further comprising:

4. a battery (5a) supported by the vehicle body (1a) and storing power in the electric motor (4, M0); the control unit (300) that, in the automatic traveling mode, when the remaining charge of the battery (5a) falls below a predetermined value based on traveling information including a charging position (411) in the field where the battery (5a) can be charged, interrupts work and sets a route for automatically traveling to the charging position (411) to charge the battery (5a), and after charging is completed, sets a route for automatically traveling to the position where work was interrupted by aligning the traveling direction of the vehicle body (1a) with the traveling direction at the time of interruption of work; 2. The work vehicle according to claim 1, further comprising:

5. a power receiver (502) that is arranged at the charging position (411) and can receive power from an optical wireless power supply device (503) that transmits power by light, the power receiver (502) being supported on the vehicle body (1a); the control unit (300) that performs work while charging within a range in which the power receiver (502) can receive power from the optical wireless power supply device (503); 5. The work vehicle according to claim 4, further comprising:

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