1. An agricultural work vehicle that automatically travels in a field, comprising: a body position calculation unit (252a) configured to calculate a body position of a body (201) of the agricultural work vehicle in the field; a body direction calculation unit (252b) configured to calculate a direction in which the body (201) faces; an automatic travel control unit (206A) configured to cause the body (201) to automatically travel based on a travel route serving as a target for automatic travel; a work start point setting unit (293a) configured to set a work start point at which field work by automatic travel is started; and a start guide management unit (257) configured to, in response to the body (201) facing a specified direction at a specified position, permit the body (201) to automatically travel along a work start point guiding route that is a travel route for the body (201) to automatically travel to the work start point.

2. The agricultural work vehicle as claimed in claim 1, wherein the field is divided into a peripheral region extending along a boundary of the field and an inward region located inward of the peripheral region, the automatic travel work is performed in the inward region by repeatedly traveling straight forward in the inward region and turning in the peripheral region, the automatic travel work is performed in the peripheral region by traveling in a loop along the boundary in the peripheral region, and the work start point guiding route is set in the peripheral region.

3. The agricultural work vehicle as claimed in claim 2, wherein in response to the direction of the body, which is facing the work start point, matching a direction of the work start point guiding route bound for the work start point, the start guide management unit (257) permits the body (201) to automatically travel along the work start point guiding route to the work start point, regardless of the distance between the body (201) and the work start point.

4. The agricultural work vehicle as claimed in claim 2 or 3, wherein in response to a front portion or a rear portion of the body (201) reaching the boundary, and furthermore the distance between the body (201) and the work start point being a predetermined distance or more, the start guide management unit (257) permits the body (201) to automatically travel along the work start point guiding route to the work start point.

5. The agricultural work vehicle as claimed in any one of claims 1 to 4, wherein in response to the body (201) facing the specified direction at the specified position, a notification is given to indicate satisfaction of a condition for automatic travel along the work start point guiding route to the work start point.

6. The agricultural work vehicle as claimed in any one of claims 1 to 5, wherein the specified position is a position in the field in which work is to be performed, the specified direction is a direction in which the work start point guiding route extends, and in response to the body (201) being on the work start point guiding route, a notification is given to indicate satisfaction of a condition for automatic travel to the work start point.

Description:DESCRIPTION

AGRICULTURAL WORK VEHICLE

Technical Field
[0001] The present invention relates to an agricultural vehicle that performs field work while automatically traveling in a field.

Background Art
[0002] Background Art 1
An agricultural vehicle according to Patent Document 1 includes a boundary data management unit that manages boundary data indicating the map position of the boundary of a field, a vehicle position calculation unit that calculates the position of the vehicle with use of satellite navigation, a travel direction calculation unit that calculates the travel direction of the vehicle body from the vehicle position, a separation distance calculation unit that calculates, as a separation distance, the longitudinal separation distance from the vehicle body to the boundary in the travel direction, and a vehicle speed management unit that manages the vehicle speed in accordance with the separation distance. According to this work vehicle, the vehicle speed management unit manages the vehicle speed in accordance with the calculated separation distance, and therefore by reducing the vehicle speed or stopping before the work vehicle reaches the boundary, it is possible to avoid the case where the agricultural vehicle comes into contact with a ridge or the like that forms the boundary.
[0003] An agricultural vehicle according to Patent Document 2 includes a travel body that travels while alternatingly traveling straight forward in the inward region of a field and making a U-turn in a ridge proximity region through manual steering or automatic steering, a field work device that performs work on the field, and a ridge proximity detection module that detects that the travel body has reached a ridge proximity region based on a vehicle position calculated based on satellite positioning. According to this agricultural vehicle, by continuously comparing the vehicle position with the position of the end point of straight forward travel for work (ridge proximity region entrance point), it is possible to, for example, reduce the vehicle speed, give a warning alert, or stop the vehicle before the vehicle enters the ridge proximity region or after the vehicle has entered the ridge proximity region.
[0004] Background Art 2
Patent Document 3 (paragraphs [0092] to [0122]) discloses a rice transplanter that performs automatic travel work in a peripheral region whose outermost periphery is the boundary of a field (this automatic travel work is performed by traveling in a loop along the field boundary in the peripheral region), and performs automatic travel work in an inward region located inward of the peripheral region (this automatic travel work is performed by alternatingly traveling straight forward in the inward region and turning in the peripheral region). The rice transplanter performs this automatic work travel with use of a pre-generated travel route as a guide. The travel route is divided into a non-work travel route for traveling without performing work (a planting device is in a raised state) and a work travel route for traveling while performing work (the planting device is in a lowered state). When transitioning from traveling while performing work to traveling without performing work, the planting device automatically changes in orientation from the raised state to the lowered state. The completion of raising of the planting device and the completion of lowering of the planting device are announced using a speech output device.
[0005] Background Art 3
Patent Document 3 (paragraphs [0092] to [0114] and FIGS. 5 to 8) disclose a rice transplanter that travels automatically while performing planting work in a field bounded by a ridge proximity line (boundary) measured in advance, and the field is divided into an inward region in which planting is to be performed first, and a peripheral region in which planting is to be performed after planting in the inward region. When the rice transplanter stops at a position before entering/exiting the field, a travel route is set in order to travel to a work start position at which planting is to be started in the inward region. A driver then performs operations on an operation unit such that the rice transplanter travels from a standby position for automatic travel, passes through the entrance/exit, automatically travels along the travel route, and then stops at the work start position. The driver then performs another operation on the operation unit in order to start planting performed while traveling automatically.

Prior Art Documents
Patent Documents
[0006] Patent Document 1: JP 2019-106983A
Patent Document 2: JP 2017-123829A
Patent Document 3: JP 2018-000039A

Disclosure of the Invention
Problem to be Solved by the Invention
[0007] Problem 1
The following is a problem corresponding to Background Art 1.
While the agricultural vehicle performs work in a field, the vehicle body needs to travel adjacent to a boundary object such as a ridge for the replenishment of agricultural material, the discharge of a harvested product, the replenishment of fuel, or the like. The agricultural vehicle disclosed in Patent Document 1 or 2 automatically stops upon approaching the boundary set in the ridge proximity region, and therefore such control for preventing arrival at the boundary needs to be disabled in order to approach a ridge for replenishment or the like. At that time, if the operator forgets to disable the boundary arrival prevention control, the operator will become confused by sudden stopping of the vehicle body. With a rice transplanter in particular, seedling replenishment and the replenishment of a chemical in a chemical sprayer are performed frequently, and it is troublesome to disable the boundary arrival prevention control.
In light of the foregoing circumstances, an object of the present invention is to provide an agricultural work vehicle that allows the vehicle body to smoothly approach a boundary object during field work.
[0008] Problem 2
The following is a problem corresponding to Background Art 2.
With the rice transplanter disclosed in Patent Document 3, the planting device is lowered when there is a transition from traveling without performing work based on a non-work travel route to traveling while performing work based on a work travel route. For this reason, there is a problem that if there is inaccuracy in the distance between the set work travel route and a boundary object such as a ridge that bounds the field, the lowered planting device may interfere with the boundary object such as the ridge, and the planting device may become damaged.
[0009] Another object of the present invention is to provide an agricultural work vehicle that enables avoiding interference between a work device a boundary object or the like as much as possible during field work in which the work vehicle can travel automatically with the work device in a lowered state while performing work.
[0010] Problem 3
The following is a problem corresponding to Background Art 3.
Although the rice transplanter disclosed in Patent Document 3 is configured to automatically travel from a standby position to a work start position, the orientation of the rice transplanter at the standby position is not specified, and therefore there is a problem that the travel route for automatically traveling from the standby position to the work start position is different depending on the orientation of the rice transplanter, and the setting of the travel route is complex.
[0011] Another object of the present invention is to provide an agricultural work vehicle that enables easily setting a travel route for automatically traveling to a work start position in field work that is performed while traveling automatically.

Means for Solving Problem
[0012] The following is a means for solving Problem 1.
An agricultural work vehicle according to an aspect of the present invention is capable of automatically traveling on a field surface bounded by a boundary object, and includes: a body position calculation unit configured to calculate a body position; a boundary-cross prevention control unit configured to prohibit travel across a boundary set to avoid contact with the boundary object, based on the boundary and the body position; a boundary-cross permission unit configured to permit crossing of the boundary by a body of the agricultural work vehicle, in accordance with a boundary-cross permission command; and a boundary-cross permission command unit configured to output the boundary-cross permission command to the boundary-cross permission unit based on at least one travel control state.
[0013] According to this configuration, the boundary-cross permission command that is output from the boundary-cross permission command unit based on the travel control state is used to make traveling across the boundary possible rather than being prohibited by the boundary-cross prevention control unit. This allows the agricultural work vehicle to approach a boundary object such as a ridge or a farm road without stopping. If a travel control state in which the body approaches a boundary object in the field such as a ridge or a farm road in order to replenish an agricultural material, discharge a harvested product, replenish fuel, or the like is detected during work performed in the field, the boundary-cross permission command that permits the body to cross the boundary is output, thus allowing the approach to be made smoothly. Note that the term “straight forward traveling” used in this specification does not strictly mean traveling in straight line, but rather includes traveling along a curve having a large radius of curvature, for example.
[0014] As a method of enabling traveling across a set boundary line, the boundary may be extended, or the boundary itself may be disabled. In view of this, in a preferred embodiment of the present invention, the boundary-cross permission command is an extension command to extend the boundary toward the boundary object or a disable command to disable the boundary, and the boundary-cross permission unit extends the boundary toward the boundary object based on the extension command, and disables the boundary based on the disable command. From a control point of view, extending the boundary to infinity is synonymous with disabling the boundary. Therefore, in the following description of the present application, extension of the boundary includes disabling the boundary. It may be possible to select in advance whether the boundary is extended or the boundary is disabled based on the boundary-cross permission command, or only one of them may be adopted. Alternatively, a selection may be made according to the travel control state.
[0015] As described above, there are several states included as travel control states serving as a trigger for extending (disabling) the boundary. In normal work travel in a field, the body changes direction (makes a turn) before reaching the boundary, regardless of whether the body is traveling automatically or being driven manually. On the other hand, if the agricultural work vehicle approaches a boundary object in the field, such as a ridge or a farm road, in order to perform agricultural material replenishment or the like, the agricultural work vehicle approaches the boundary and then continues to travel forward. Such a travel control state can be used as a trigger for extending the boundary. In view of this, in a preferred embodiment of the present invention, the at least one travel control state includes a straight approach state in which a distance from the body position to the boundary reaches a predetermined distance in straight travel toward the boundary object, and the boundary-cross permission command is output in response to detection of the straight approach state.
[0016] Some agricultural work vehicles capable of automatic traveling include a remote controller that enables performing operations such as starting and stopping automatic travel and giving minor travel instructions, for example. Since the remote controller is operated manually, a safety check by the operator is a prerequisite for traveling using the remote controller. In view of this, a travel control state of traveling based on a remote control operation can be used as a trigger for extending the boundary. In view of this, in a preferred embodiment of the present invention, the at least one travel control state includes a remote control approach traveling state of approaching the boundary object in accordance with a remote control operation, and the boundary-cross permission command is output in response to detection of the remote control approach traveling state.
[0017] It is also possible for a worker to perform a manual operation to cause the agricultural work vehicle to approach a ridge, a farm road, or the like in order to perform agricultural material replenishment or the like. In this case, the worker uses a manual travel operation tool to repeatedly perform minor travel operations to cause the agricultural work vehicle to approach the ridge, the farm road, or the like. In view of this, a travel control state in which the agricultural work vehicle is caused to approach a ridge, a farm road, or the like by an operation performed on the manual travel operation tool can be used as a trigger for extending the boundary. In view of this, in a preferred embodiment of the present invention, the at least one travel control state includes a manual approach traveling state of approaching the boundary object in accordance with an operation performed on a manual travel operation tool, and the boundary-cross permission command is output in response to detection of the manual approach traveling state.
[0018] In many types of agricultural work performed in a field by an agricultural work vehicle, the field surface targeted for work is divided into a peripheral region and an inward region located inward of the peripheral region, and work is performed in the inward region by repeatedly traveling straight forward and then making a turn (mainly making a U-turn) to change direction. At this time, the turning is performed in the peripheral region. Work in the peripheral region is carried out by traveling in a loop along a boundary object such as a ridge or a farm road. In the case of an agricultural work vehicle that performs harvesting work, such as a combine, work travel is first performed in the peripheral region, and then work travel is performed in the inward region. In the case of a rice transplanter, a fertilizer device, a chemical sprayer, or the like, work travel is first performed in the inward region, and then work travel is performed in the peripheral region. If agricultural material replenishment, harvest product discharge, or the like is to be performed during the work travel performed in the inward region, rather than making a turn in the peripheral region, the agricultural work vehicle continues to travel forward and approaches a ridge, a farm road, or the like. In view of this, a travel control state in which the work vehicle continues to travel straight from the inward region to the peripheral region can be used as a trigger for extending the boundary. In view of this, in a preferred embodiment of the present invention, the field surface is divided into a peripheral region extending along the boundary and an inward region located inward of the peripheral region, the agricultural work vehicle is provided with a loop work travel mode of performing work in the peripheral region while traveling in a loop along the peripheral region, and an inward work travel mode of performing work in the inward region while repeatedly traveling straight forward and making a U-turn, and in response to the body traveling straight forward up to the peripheral region in the inward work travel mode and then the inward work travel mode being suspended, the boundary is extended by the boundary-cross permission unit.
[0019] Work travel in the inward work travel mode is suspended, the body approaches a ridge, a farm, or the like, agricultural material replenishment, harvested product discharge, or the like is performed, and then the body again returns to the inward region, and work travel in the inward work travel mode is resumed. When the work travel in the inward work travel mode is resumed, the extended boundary needs to be restored to the original state. It is convenient if this restoration of the boundary is also controlled automatically. In view of this, in a preferred embodiment of the present invention, extension or disabling of the boundary by the boundary-cross permission unit is canceled in response to resumption of the inward work travel mode that was suspended.
[0020] Control is performed based on the boundary and the body position in order to avoid interference with a boundary object, and therefore it is preferable that the boundary and the body position are calculated accurately and quickly by the same method. In view of this, in a preferred embodiment of the present invention, the body position and a position of the boundary are calculated using satellite positioning. At this time, the boundary can be calculated based on a travel path obtained by satellite positioning when the agricultural work vehicle is caused to travel along the boundary object. At this time, when the final boundary position is determined, it is convenient if a safety distance is added (the boundary is offset toward the field interior) such that the agricultural work vehicle does not come into contact with a boundary object such as a ridge even if unexpected slipping or steering wobbling occurs. In view of this, in a preferred embodiment of the present invention, the boundary is offset inward, relative to the field, from the boundary object by a predetermined distance.
[0021] The following is a means for solving Problem 2.
An agricultural work vehicle according to an aspect of the present invention is an agricultural work vehicle that automatically travels in a field, including: a work device raisable and lowerable relative to a body of the agricultural work vehicle; a body position calculation unit configured to calculate a body position of the body in the field; a travel route generation unit configured to generate a travel route serving as a target for automatic travel, based on a field map; an automatic travel control unit configured to cause the body to automatically travel based on the travel route; a driving control state detection unit configured to detect an automatic pause according to which the body stops before a transition from non-work travel with the work device in a raised state to automatic work travel with the work device in a lowered state; and an automatic work travel management unit configured to include a pre-commencement operation performed by a driver as an automatic work travel start condition for transitioning from the automatic pause to the automatic work travel in response to detection of the automatic pause.
[0022] According to this configuration, when the agricultural work vehicle is automatically paused in accordance with a stop performed before a transition to automatic work travel, the driver needs to perform a pre-commencement operation in order for automatic work travel to be started. This pre-commencement operation performed by the driver is an operation that indicates that it has been confirmed that a work device will not interfere with a boundary object or the like even if the work device is lowered. Due to such an operation indicating safety confirmation being included in the automatic work start condition, even if other start conditions are satisfied, if the operation indicating safety confirmation has not been performed, automatic work travel is not started, and consequently the work device is not lowered. During the automatic pause, the driver can check whether or not the work device will not interfere with a boundary object or the like even if the work device is lowered. If it is confirmed that interference will not occur, the driver performs an operation to allow the work device to be lowered. Accordingly, the agricultural work vehicle transitions from the automatic pause state to automatic work travel. If the driver determines that the work device and a boundary object or the like will interfere with each other, the driver takes an interference avoidance action to avoid such interference.
[0023] If the driver confirms that the work device will not interfere with a boundary object or the like even if the work device is lowered, a transition from the automatic pause state to automatic work travel can be performed, and the work device may be lowered. In view of this, it is convenient to adopt a work device lowering operation performed by the driver as the pre-commencement operation. Accordingly, in a preferred embodiment of the present invention, the pre-commencement operation is a lowering operation for lowering the work device.
[0024] Of course, even if the driver does not perform the work device lowering operation, if an operation indicating that the driver confirmed that the work device will not interfere with a boundary object or the like even if lowering has been performed, the work device may be automatically lowered, and automatic work travel may be started. Accordingly, in a preferred embodiment of the present invention, the pre-commencement operation is an operation indicating that a lowered position of the work device was confirmed.
[0025] One example of an interference avoidance action taken when the driver determines that the work device and a boundary object or the like will interfere with each other is an operation in which the driver changes the next travel route for automatic work travel to a travel route that avoids interference between the work device and a boundary object or the like. If such a change in the travel route is performed, interference between the lowered work device and a boundary object or the like is avoided. In other words, a travel route change operation is a preferable pre-commencement operation for starting automatic work travel in the case where the driver has determined that interference will occur between the work device and a boundary object or the like. In view of this, in a preferred embodiment of the present invention, the pre-commencement operation includes changing the travel route in order to change the lowered position. At that time, if the work device and the boundary object or the like will not interfere with each other, it is not necessary to change the travel route, and therefore the driver performs an operation that does not require changing the travel route.
[0026] In the present invention, in order to transition from the automatic pause state to automatic work travel, a pre-commencement operation needs to be performed by the driver, and the driver needs to be made aware of such an operation. In view of this, in a preferred embodiment of the present invention, the automatic work travel management unit is further configured to give a notification requesting the driver to perform the pre-commencement operation.
[0027] In a preferred embodiment of the present invention, the field is divided into a peripheral region extending along a boundary of the field and an inward region located inward of the peripheral region, the automatic travel work is performed in the inward region by repeatedly traveling straight forward in the inward region and turning in the peripheral region, the automatic travel work is performed in the peripheral region by traveling in a loop along the boundary in the peripheral region, and the pre-commencement operation is included as the automatic work travel start condition in response to a transition to the automatic work travel in the peripheral region. In an agricultural work vehicle that performs work in a field, incidents such as damage to the lowered work device occur most often when starting loop travel along a boundary defined by a ridge or the like in the peripheral region. In view of this, it is rational if the pre-commencement operation is used a start condition for transitioning from the automatic pause state to automatic work travel in the case where there is a transition to automatic work travel in the peripheral region.
[0028] Incidents such as damage to the work device due to being lowered occur also in the case where there is a travel obstacle that will interfere with work travel in the field. In other words, if the accuracy of the travel route for avoiding a travel obstacle is insufficient, the lowered work device and the travel obstacle will interfere with each other, and the work device will be damaged. In view of this, in a preferred embodiment of the present invention, the pre-commencement operation is included as the automatic work travel start condition in response to a transition to the automatic work travel in an obstacle avoidance travel route for avoiding a travel obstacle located in the field.
[0029] The following is a means for solving Problem 3.
An agricultural work vehicle according to an aspect of the present invention is an agricultural work vehicle that automatically travels in a field, including: a body position calculation unit configured to calculate a body position of a body of the agricultural work vehicle in the field; a body direction calculation unit configured to calculate a direction in which the body faces; an automatic travel control unit configured to cause the body to automatically travel based on a travel route serving as a target for automatic travel; a work start point setting unit configured to set a work start point at which field work by automatic travel is started; and a start guide management unit configured to, in response to the body facing a specified direction at a specified position, permit the body to automatically travel along a work start point guiding route that is a travel route for the body to automatically travel to the work start point.
[0030] According to this configuration, in the case where the agricultural work vehicle is stopped at a standby position for automatic travel (automatic travel start position), only if the body position and the body direction satisfy a preset specific condition, the agricultural work vehicle is permitted to automatically travel along a work start point guiding route to a work start point. If the agricultural work vehicle is permitted to automatically travel along the work start point guiding route (work start point guidance travel), the agricultural work vehicle starts to automatically travel with use of the work start point guiding route as a target route, and arrives at the work start point. Upon reaching the work start point, the agricultural work vehicle starts to perform field work while automatically traveling with use of a pre-generated travel route as a target route. The specified position and the specified direction are set such that the agricultural work vehicle, which is waiting for the start of automatic travel, can smoothly transition to the work start point guidance route, and thus work start point guiding travel is performed smoothly, and the time required for such travel is appropriate.
[0031] In a preferred embodiment of the present invention, the field is divided into a peripheral region extending along a boundary of the field and an inward region located inward of the peripheral region, the automatic travel work is performed in the inward region by repeatedly traveling straight forward in the inward region and turning in the peripheral region, the automatic travel work is performed in the peripheral region by traveling in a loop along the boundary in the peripheral region, and the work start point guiding route is set in the peripheral region. An agricultural work vehicle such as a rice transplanter or a fertilizer distributer enters a field through an entrance/exit, performs work travel in an inward region, then performs work travel in a peripheral region, and then exits the field through the entrance/exit. Due to performing work travel in this way, a worked region is not damaged in work travel that is performed at a later time. If the work start point guiding route is set in the peripheral region, and the direction and the position of the agricultural work vehicle are limited in order to easily transition to the work start point guiding route, the agricultural work vehicle that is waiting in the vicinity of the entrance/exit can efficiently automatically travel from the standby position to the work start position.
[0032] In order to facilitate the transition to the work start point guiding route, it is preferable that the traveling direction of the agricultural work vehicle stopped at the standby position matches the direction of the work start point guidance route. In view of this, in a preferred embodiment of the present invention, in response to the direction of the body, which is facing the work start point, matching a direction of the work start point guiding route bound for the work start point, the start guide management unit permits the body to automatically travel along the work start point guiding route to the work start point, regardless of the distance between the body and the work start point. Here, the directions do not need to match exactly, and a difference of around several tens of degrees is allowed. For example, if the direction of the work start point guiding route and the direction of the body are opposite to each other, a complex transition route for reaching the work start point guiding route needs to be added to the work start point guiding route, and therefore work start point guiding travel based on the work start point guiding route is prohibited. According to this configuration, regardless of where the rice transplanter is waiting on the straight work start point guiding route, work start point guiding travel is permitted as long as the rice transplanter is facing the work start point, and therefore flexibility is improved.
[0033] However, with an agricultural work vehicle such as a rice transplanter or a fertilizer distributer, in order to perform field material replenishment before starting field work, it is often the case that, after entering the field, the agricultural work vehicle travels until the front portion or the rear portion of the body reaches a boundary such as a ridge. Since the material replenishment position and the work start position are normally located in a region on the same side in the peripheral region, as long as there is enough space for cutbacks, by performing cutback travel (including reverse turning) using a standardized pattern, the traveling direction of the vehicle can be smoothly aligned with the work start position. In view of this, in a preferred embodiment of the present invention, in response to a front portion or a rear portion of the body reaching the boundary, and furthermore the distance between the body and the work start point being a predetermined distance or more, the start guide management unit permits the body to automatically travel along the work start point guiding route to the work start point. A standardized cutback travel route is applied to the work start point guiding route used in this case.
[0034] In order to start the work start point guiding travel to the work start point, the driver needs to perform a manual operation for transitioning to automatic travel. For this reason, it is preferable to notify the driver that the agricultural work vehicle has reached a position where automatic travel along the work start point guiding route is possible. In view of this, in a preferred embodiment of the present invention, in response to the body facing the specified direction at the specified position, a notification is given to indicate satisfaction of a condition for automatic travel along the work start point guiding route to the work start point. In another more preferred embodiment of the present invention, the specified position is a position in the field in which work is to be performed, the specified direction is a direction in which the work start point guiding route extends, and in response to the body being on the work start point guiding route, a notification is given to indicate satisfaction of a condition for automatic travel to the work start point.

Brief Description of the Drawings
[0035] FIG. 1 shows a first embodiment (the same applies up to FIG. 9), and is a side view of a rice transplanter, which is one example of an agricultural work vehicle.
FIG. 2 is a flowchart showing a flow of seedling planting work performed while traveling automatically.
FIG. 3 is a schematic view of an arrangement of obstacle detectors.
FIG. 4 is an illustrative view of the division of regions in a field in which travel routes are set.
FIG. 5 is an illustrative diagram for describing a loop travel route set in a peripheral region and the traveling of the rice transplanter.
FIG. 6 is an illustrative diagram for describing a back-and-forth travel route set in an inward region and the traveling of the rice transplanter.
FIG. 7 is a function block diagram of a control system of the rice transplanter.
FIG. 8 is an illustrative diagram for describing the extension of a boundary based on the travel control state.
FIG. 9 is a plan view of a remote controller.
FIG. 10 shows a second embodiment (the same applies up to FIG. 19), and is a side view of a rice transplanter, which is one example of an agricultural work vehicle.
FIG. 11 is a flowchart showing a flow of seedling planting work performed while traveling automatically.
FIG. 12 is a schematic view of an arrangement of obstacle detectors.
FIG. 13 is an illustrative view of the division of regions in a field in which travel routes are set.
FIG. 14 is an illustrative diagram for describing a loop travel route set in a peripheral region and the traveling of the rice transplanter.
FIG. 15 is an illustrative diagram for describing a back-and-forth travel route set in an inward region and the traveling of the rice transplanter.
FIG. 16 is an illustrative diagram for describing non-work travel along a straight route in a back-and-forth travel route.
FIG. 17 is an illustrative diagram for describing an example of lowering safety check control.
FIG. 18 is an illustrative diagram for describing another example of lowering safety check control.
FIG. 19 is a function block diagram for describing function units of a control system of the rice transplanter.
FIG. 20 shows a third embodiment (the same applies up to FIG. 29), and is a side view of a rice transplanter, which is one example of an agricultural work vehicle.
FIG. 21 is a flowchart showing a flow of seedling planting work performed while traveling automatically.
FIG. 22 is a schematic view of an arrangement of obstacle detectors.
FIG. 23 is an illustrative view of the division of regions in a field in which travel routes are set.
FIG. 24 is an illustrative diagram for describing a loop travel route set in a peripheral region and the traveling of the rice transplanter.
FIG. 25 is an illustrative diagram for describing a back-and-forth travel route set in an inward region and the traveling of the rice transplanter.
FIG. 26 is an illustrative diagram for describing one permission condition for traveling automatically with use of a work start point guiding route.
FIG. 27 is an illustrative diagram for describing another permission condition for traveling automatically with use of a work start point guiding route.
FIG. 28 is an illustrative diagram for describing non-work travel along a straight route in a back-and-forth travel route.
FIG. 29 is a function block diagram for describing function units of a control system of the rice transplanter.

Best Mode for Carrying out the Invention
[0036] First Embodiment
The following describes a riding rice transplanter as an example of an embodiment of an agricultural work vehicle according to the present invention. This rice transplanter can automatically travel on the surface of a field that is bounded by boundary objects. Note that in the present specification, unless specified otherwise, “front” means the front side in the front-rear direction of the body of the rice transplanter (traveling direction), and “rear” means the rear side in the front-rear direction of the body of the rice transplanter (traveling direction). Also, the left-right direction and the lateral direction mean the transverse direction of the body (body width direction) that is orthogonal to the front-rear direction of the body. Also, the terms “up” and “down” are in a positional relationship along the perpendicular direction of the vehicle body (vertical direction), and indicate a relationship regarding ground height.
[0037] FIG. 1 is a side view of the rice transplanter. The rice transplanter includes a riding type of four-wheel-drive travel body (hereinafter called the body 1). The body 1 includes a parallel quadruple link type of link mechanism 11 that is coupled to the rear portion of the body 1 so as to be able to swing up and down, a hydraulic lift cylinder 11a that drives the link mechanism 11 to swing, a seedling planting device 3 (an example of an agricultural material dispensing device) that is rollably coupled to a rear end portion of the link mechanism 11, and a fertilizer application device 4 that extends from a rear end portion of the body 1 to the seedling planting device 3, for example.
[0038] The body 1 includes wheels 12, an engine 13, and a hydraulic continuously variable transmission 14 as mechanisms for traveling. The wheels 12 include left and right front wheels 12A that can be steered and left and right rear wheels 12B that cannot be steered. The engine 13 and the continuously variable transmission 14 are arranged in a front portion of the body 1. Motive power is supplied from the engine 13 to the front wheels 12A, the rear wheels 12B, and the like via the continuously variable transmission 14 and the like.
[0039] The seedling planting device 3 is configured as an eight-row planting type of device, for example. The seedling planting device 3 includes a seedling stand 31, planting mechanisms 32 corresponding to eight rows, and the like. Note that the seedling planting device 3 can be changed to two-row planting, four-row planting, six-row planting, and the like by controlling row clutches (not shown).
[0040] The seedling stand 31 is a platform on which seedlings for eight rows are placed in a mat. The seedling stand 31 moves back and forth in the left-right direction with a certain stroke that corresponds to the left-right width of the seedling mat, and each time the seedling stand 31 reaches the left and right stroke ends, a vertical feed mechanism 33 vertically feeds seedlings in the mat on the seedling stand 31 toward the lower end of the seedling stand 31 at a predetermined pitch. The eight planting mechanisms 32 are rotary-type mechanisms, and are arranged in the left-right direction at regular intervals corresponding to the spaces between the planting rows. Using motive power from the body 1, each planting mechanism 32 cuts one seedling from the lower end of the seedling mat placed on the seedling stand 31, and plants the cut seedling in a leveled mud region.
[0041] The seedling planting device 3 includes a seedling amount adjusting function for adjusting the amount of seedlings that are to be fed by the planting mechanisms 32. Each planting mechanism 32 feeds and plants a seedling for one plant through a seedling feed port formed in a guide rail that guides the sliding of the lower end of the seedling stand 31. The amount of seedlings is adjusted by changing the vertical positions of the seedling stand 31 and the guide rail that guides the sliding of the lower end of the seedling stand 31.
[0042] As shown in FIG. 1, the fertilizer application device 4 includes a wide hopper 41, feeding mechanisms 42, an electric blower 43, a plurality of fertilizer application hoses 44, and a furrow maker 45 provided for each row. The hopper 41 stores granular or powdered fertilizer. The feeding mechanisms 42 are operated by motive power transmitted from the engine 13, and feed out a predetermined amount of fertilizer for two rows from the hopper 41. The fertilizer application device 4 has a feeding amount adjusting function for changing the amount of fertilizer that is fed by the feeding mechanisms 42.
[0043] The blower 43 is operated by electric power from a battery (not shown) provided in the body 1, and generates transport wind for transporting fertilizer delivered by the feeding mechanisms 42 toward the mud surface of the field. By starting/stopping the operation of the blower 43 or the like, the fertilizer application device 4 can switch between an operating state in which a predetermined amount of fertilizer stored in the hopper 41 is supplied to the field and a non-operating state in which the supply is stopped.
[0044] The fertilizer application hoses 44 guide the fertilizer transported by the transport wind to corresponding furrow makers 45. Each furrow maker 45 is arranged on a leveling float 15. The furrow makers 45 move up and down together with the leveling floats 15 to form fertilizer furrows in mud regions of a paddy field and guide the fertilizer into the fertilizer furrows while the work vehicle travels with the leveling float 15 in contact with the ground.
[0045] The body 1 includes a driver section 20 on the rear portion side. The driver section 20 includes manual travel operation tools such as a steering wheel 21 for steering the front wheels, a main shift lever 22 for adjusting the vehicle speed by performing shift operation of the continuously variable transmission 14, an auxiliary shift lever 23 that enables shift operation of an auxiliary transmission device, and a work operation lever 25 that enables the raising and lowering of the seedling planting device 3 and the switching of the operating state of the same, for example. Also, a general-purpose terminal 9 is provided in front of a driver seat 16. The general-purpose terminal 9 includes a notification device that displays various types of information and gives notifications to the operator, and a touch panel that accepts the input of various types of information. A driving mode switching operation tool 24 for operation by the driver is provided in the vicinity of the steering wheel 21. Also, a backup seedling frame 17 for accommodating backup seedlings is provided in front of the driver section 20.
[0046] The steering wheel 21 is coupled to the front wheels 12A via a steering mechanism (not shown), and the steering angle of the front wheels 12A is adjusted by rotating the steering wheel 21. A steering motor M1 is also coupled to the steering mechanism, and, during automatic travel, the steering angle of the front wheels 12A is adjusted by the steering motor M1 operating based on a steering signal. A shift operation motor M2 for automatically operating the main shift lever 22 is also provided, and, during automatic travel, the shift position of the continuously variable transmission 14 is adjusted by the shift operation motor M2 operating based on a shifting signal.
[0047] An extension frame 17a that extends upward is provided on an upper portion of the backup seedling frame 17. The extension frame 17a has attached thereto a tower lamp 18 in which a plurality of color lamps for notifying the state of the rice transplanter are arranged in the vertical direction, and a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position and direction (body direction) of the body 1. The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from satellites in the Global Navigation Satellite System (GNSS) and an inertial measurement unit 8B that detects the tilt and acceleration of the body 1 in three axes.
[0048] FIG. 2 shows an example of a processing procedure in which the rice transplanter performs seedling planting work by a combination of automatic travel and manual travel. In the example of FIG. 2, the seedling planting work includes work pre-processing #A, map creation processing #B, boundary calculation processing #C, route generation processing #D, work start point guidance processing #E, inward back-and-forth planting processing #G, and peripheral planting processing #H. Also, seedling replenishment processing #F is performed in the inward back-and-forth planting processing #E. The seedling replenishment processing #F may also be performed in the peripheral planting processing #G.
[0049] In the work pre-processing #A, a communication check is performed regarding communication between the units of the control system of the rice transplanter, and a communication check is performed for the positioning unit 8, for example. Also, since the rice transplanter can be remotely controlled using a remote controller 90 (see FIG. 1) and performs obstacle detection using obstacle detectors 80 (see FIG. 3), function checks are also performed for the remote controller 90 and the obstacle detectors 80 in pre-processing. As shown in FIG. 3, the obstacle detectors 80 in the embodiment are sonar-type detectors, and include four front sonar devices 80f whose detection ranges are regions in front of the body 1, two side sonar devices 80s whose detection ranges are regions on the left and right of the body 1, and two rear sonar devices 80r whose detection ranges are regions in front of the body 1.
[0050] The map creation processing #B is processing for creating a map of the field targeted for work, that is to say measuring the outer shape of the field surface. A travel path is calculated based on position signals from the positioning unit 8 obtained when the rice transplanter approaches a boundary object such as a ridge that bounds the field surface and is then manually driven along the boundary object (map creation teaching traveling). Field contour lines serving as map information regarding the field surface (i.e., a field map) is obtained based on the travel path.
[0051] As shown in FIG. 4, the boundary calculation processing #C is processing for calculating, based on the travel path calculated in the map creation processing #B, a boundary that indicates the limit of positions of the body 1 for the rice transplanter to avoid contact with a boundary object in the field. In normal traveling of the rice transplanter, the rice transplanter does not come into contact with a boundary object such as a ridge unless the position of the body 1 crosses the boundary (also called a cross-border line). When the position of the body 1 reaches the boundary, the body 1 is forcibly stopped. Since the rice transplanter can travel automatically, when the final boundary position is determined, a safety distance is added such that the rice transplanter does not come into contact with a boundary object such as a ridge even if unexpected slipping or steering wobbling occurs. In other words, the boundary is offset toward the interior of the field by a predetermined distance from the boundary object of the field.
[0052] In the route generation processing #D, a travel route serving as an automatic travel target set in the field map created in the map creation processing #B is created using a predetermined algorithm. A travel route generated for seedling planting work performed by automatic traveling will be described below.
[0053] As shown in FIG. 4, the field surface defined by the field map is divided into a peripheral region and an inward region. The generated travel route includes a loop travel route set in the peripheral region (see FIG. 5) and a back-and-forth travel route set in the inward region (see FIG. 6). The rice transplanter first performs seedling planting work in the inward region while traveling along the back-and-forth travel route (hereinafter called an “inward work travel mode”), and then performs seedling planting work in the peripheral region while traveling along the loop travel route (hereinafter called a “loop work travel mode”).
[0054] The loop travel route is made up of loop straight routes that extend parallel to a field boundary object (ridge) and direction change routes that involve forward travel and reverse travel to connect loop straight routes to each other. In FIG. 5, the reference sign R1 is assigned to loop straight routes, and the reference sign R2 is assigned to direction change routes. The back-and-forth travel route is made up of a large number of straight routes that are substantially parallel to each other and turning routes (U-turn routes) that connect straight routes to each other. In each straight route, the planting of seedlings is started at a planting start position (which is also a turning end position), and the planting of seedlings is ended at a planting end position (which is also a turning start position). In FIG. 6, the reference sign US is assigned to the planting start position, the reference sign UF is assigned to the planting end position, R3 is assigned to a straight route, and the reference sign R5 is assigned to a turning route. In FIGS. 5 and 6, the reference numeral R4 is assigned to a transition route for transitioning from a back-and-forth travel route to a loop travel route. In this example, the transition route is similar to a turning route. Also, in FIGS. 5 and 6, the working width of the rice transplanter is indicated by the reference sign W, the region for the rice transplanter to enter/exit the field is indicated by diagonal lines and assigned the reference sign GA. FIG. 6 shows a start guide route (assigned the reference numeral R6 in FIG. 6) for traveling from the entrance/exit to a travel start position (assigned the reference numeral S in FIG. 6) of a back-and-forth travel route. In the turning routes, the direction change routes, the start guide route, and the transition routes, the rice transplanter travels without performing work, and thus these routes are shown by dashed lines. In the loop straight routes and the straight routes, the rice transplanter performs work while traveling, and thus these routes are shown by solid lines.
[0055] In the work start point guidance processing #E, after map creation teaching traveling has ended and the rice transplanter has stopped in the vicinity of the entrance/exit, the rice transplanter automatically travels to the travel start position along the start guide route, which is a travel route to the travel start position, which is the start point of seedling planting work.
[0056] In the inward back-and-forth planting processing #F, the travel mode is set to the inward work travel mode, the rice transplanter automatically travels along the back-and-forth travel route shown in FIG. 6, and seedling planting work is performed in the inward region. If the inward region is large, the seedling replenishment processing #G for loading seedling boxes into the backup seedling frame 17 is performed during back-and-forth travel. In the seedling replenishment processing #G, the rice transplanter temporarily stops before transitioning from a straight route to a turning route. Thereafter, using the remote controller 90, a manual operation tool, or the like, the rice transplanter is caused to perform forward approach travel for bringing the front end (i.e., the backup seedling frame 17) close to a ridge. In the forward approach travel, the body 1 travels to a position just before contact with the ridge. Therefore, in order to prevent the body 1 from making an emergency stop due to the position of the body 1 crossing the boundary, the boundary is extended in the seedling replenishment processing #G. After seedling replenishment ends, the rice transplanter automatically travels to the straight route that is scheduled next after the straight route that was exited, and then resumes seedling planting work along the target straight route. When the next straight route is acquired and the seedling planting work resumes during automatic travel, the boundary that had been temporarily extended is restored to its original state.
[0057] Note that if fertilizer application work or chemical spraying work is to be performed at the same time as the seedling planting work, fertilizer replenishment or chemical replenishment is also required during the execution of the inward back-and-forth planting processing #F. In such replenishment work as well, similarly to the seedling replenishment work, the rice planter is manually driven so as to approach a ridge, and then returns through automatic traveling. However, if it is necessary to move the rear end of the body 1 toward the ridge during fertilizer replenishment or chemical replenishment, the body 1 stops just before entering the next straight route after a turning route, the ridge is approached by reverse travel, replenishing is performed, and then the body 1 travels forward to return to the target straight route.
[0058] When the inward back-and-forth planting processing #F ends, the traveling mode is set to the loop work travel mode, and the peripheral planting processing #H, which is processing for performing seedling planting work along loop travel route shown in FIG. 5, is executed. In this embodiment, the loop travel route includes an inner loop travel route for first traveling along a full inward loop, and an outer loop travel route for subsequently traveling along a full outward loop. Basically, since the end position of the outer loop travel route is the entrance/exit of the field, after performing seedling planting work along the outer loop travel route, the rice transplanter exits the field through the entrance/exit. Seedling planting work along the inner loop travel route is performed by traveling automatically. Seedling planting work along the outer loop travel route requires precise traveling, and therefore even if automatic travel is performed, it is preferable that manned automatic travel is performed in which a driver is on board as a monitor.
[0059] FIG. 7 shows a control block diagram of the control system of the rice transplanter. The control system of the rice transplanter includes a control device 100 that controls various operations of the rice transplanter, the general-purpose terminal 9 that can exchange data with the control device 100, and the remote controller 90. Signals from the positioning unit 8, the driving mode switching operation tool 24, a travel sensor group 28, a work sensor group 29, and the obstacle detectors 80 are input to the control device 100. Control signals from the control device 100 are output to a travel device group 1A and a work device group 1B.
[0060] The travel device group 1A includes, for example, the steering motor M1 and the shift operation motor M2, and the control device 100 outputs control signals to control the steering motor M1 to adjust the steering angle and to control the shift operation motor M2 to adjust the vehicle speed.
[0061] The work device group 1B includes, for example, the lift cylinder 11a for raising and lowering the seedling planting device 3, a seedling amount adjuster for adjusting the amount of seedlings to be fed by the planting mechanisms 32, and a feeding amount adjuster for adjusting the amount of fertilizer fed by the feeding mechanisms 42.
[0062] The travel sensor group 28 includes various sensors that detect states of the steering angle, the vehicle speed, the engine speed, and the like, as well as set values for the same. The work sensor group 29 includes various sensors that detect states of the link mechanism 11, the seedling planting device 3, and the fertilizer application device 4.
[0063] The control device 100 includes a travel control unit 6, a work control unit 51, a body position calculation unit 52, a travel route management unit 53, a driving control state detection unit 55, a boundary management unit 56, an input signal processing unit 50a, and a communication unit 50b.
[0064] The input signal processing unit 50a processes signals from various sensors, switches, levers, and the like provided in the rice transplanter, and transfers the processed signals to function units configured in the control device 100. The communication unit 50b has a wireless communication function, performs data communication with an external device such as the remote controller 90, and transfers received data to the input signal processing unit 50a.
[0065] The travel control unit 6 includes an automatic travel control unit 6A, a manual travel control unit 6B, and a control management unit 6C. The automatic travel control unit 6A performs speed control and steering control during automatic traveling. Lateral deviation and directional deviation are calculated by comparing the target travel route set by the travel route management unit 53 with the body position calculated by the body position calculation unit 52, and steering control is performed so as to reduce the lateral deviation and the directional deviation.
[0066] In addition to the automatic travel mode of automatically traveling along a target travel route, the rice transplanter includes a straight maintenance driving mode of automatically traveling straight forward so as to maintain the direction of a reference line defined by at least two points. A straight travel route managed by the travel route management unit 53 can be additionally used as the reference line used in the straight maintenance driving mode.
[0067] In a manual driving mode, the manual travel control unit 6B controls the steering motor M1 based on operation of the steering wheel 21. The control management unit 6C selects the automatic travel mode, the straight maintenance driving mode, or the manual driving mode based on a signal from the driving mode switching operation tool 24.
[0068] In automatic travel, the work control unit 51 automatically controls the work device group 1B based on a program given in advance, whereas in manual travel, the work control unit 51 controls the work device group 1B based on operations performed by the driver. The body position calculation unit 52 calculates map coordinates (the body position) of the body 1 based on satellite positioning data sequentially transmitted by the positioning unit 8.
[0069] In this embodiment, the general-purpose terminal 9 includes a field information storage unit 91, a field map creation unit 92, a travel route generation unit 93, a boundary calculation unit 94, and a travel path generation unit 95. The field information storage unit 91 stores information regarding the field, such as the planted seed, the entrance (exit) position of the field, and the position where seedlings can be replenished. The field map creation unit 92 performs the map creation processing described with reference to FIG. 2. The travel route generation unit 93 divides the field into a peripheral region and an inward region based on the field map created by the field map creation unit 92, and generates a loop travel route for traveling in the peripheral region and a back-and-forth travel route for the inward region. The boundary calculation unit 94 performs the boundary calculation processing described with reference to FIG. 2. The map creation processing performed by the field map creation unit 92 and the boundary calculation processing performed by the boundary calculation unit 94 require the travel path in map creation teaching traveling. The travel path generation unit 95 generates a travel path for the body 1 based on the body positions calculated by the body position calculation unit 52.
[0070] The travel route management unit 53 receives the travel routes generated by the travel route generation unit 93 from the general-purpose terminal 9 and manages the received travel routes, and also sequentially sets target travel routes for steering the body in the automatic travel mode.
[0071] The driving control state detection unit 55 detects travel control states and work control states based on control information handled by the control device 60. The following states are included among the travel control states detected by the driving control state detection unit 55.
(a) Straight approach state: the distance from the position of the body 1 (body position) to the boundary has reached a predetermined distance when the body 1 exits the inward region and travels straight toward a ridge (one type of boundary object) for seedling replenishment or the like.
(B) Remote control approach traveling state: the body 1 exits the inward region and approaches a ridge through remote control operation performed using the remote controller 90.
(C) Manual approach traveling state: the body 1 exits the inward region and approaches a ridge in accordance with operations performed on a manual travel operation tool.
(D) Peripheral region turn traveling state: the body 1 performs direction change travel (U-turn travel or the like) with a predetermined steering angle or more in the peripheral region.
[0072] The boundary management unit 56 manages the boundaries (boundary data) calculated by the boundary calculation unit 94, and thus includes a boundary storage unit 56a, a boundary-cross prevention control unit 56b, a boundary-cross permission unit 56c, and a boundary-cross permission command unit 56d. The boundary storage unit 56a stores boundaries received from the boundary calculation unit 94. The boundary-cross prevention control unit 56b determines whether or not the body 1 will cross a boundary based on the body position, and gives a stop command, which is for prohibiting the body 1 from traveling across the boundary, to the travel control unit 6. The boundary-cross permission unit 56c temporarily extends a boundary stored in the boundary storage unit 56a toward a ridge. By extending the boundary, the body 1 can approach a position just before a ridge. The boundary is set to maintain a safe distance between the rice transplanter and a boundary object such as a ridge, but the extended boundary is set at a position where the rice transplanter can reach a position just before the boundary object without coming into contact with the boundary object. Accordingly, in order to avoid interference between the body 1 and the ridge, the approaching travel must be performed at low speed and manually.
[0073] When a certain travel control state is detected by the driving control state detection unit 55, the boundary-cross permission command unit 56d gives a boundary-cross permission command to the boundary-cross permission unit 56c to extend the boundary toward the ridge. In this embodiment, the boundary-cross permission command unit 56d gives a boundary-cross permission command to the boundary-cross permission unit 56c in the case where the above-mentioned remote control approach traveling state is detected by the driving control state detection unit 55. If seedling replenishment needs to be performed while seedling planting work is being performed in the inward region through unmanned automatic traveling, the monitor operates the remote controller 90 to temporarily suspend the automatic traveling in the inward work travel mode, and causes the body 1 to approach the ridge as shown in FIG. 8. In FIG. 8 as well, R3 is assigned to straight routes, the reference sign R5 is assigned to turning routes, and the reference sign UF is assigned to the planting end position (turning start position). After entering the peripheral region from the planting end position, if the body 1 travels straight forward instead of turning in accordance with a remote control operation, the boundary is extended in accordance with a boundary-cross permission command, and the body 1 approaches the ridge instead of stopping. When seedling replenishment is complete, the monitor operates the remote controller 90 to give a command for returning to automatic traveling. Accordingly, the body 1 reverses and returns to the planting end position through automatic traveling. At this stage, back-and-forth travel in the inward region that had been performed in the suspended inward work travel mode is resumed, the extension of the boundary is cancelled, and the position of the boundary is restored to the original position.
[0074] The following describes a procedure of seedling replenishment processing performed in unmanned automatic traveling. During seedling replenishment processing, the rice transplanter is controlled by remote control operations performed by a monitor who is outside of the field. The remote controller 90 includes seven buttons and two indicators, as shown in FIG. 9. A first button 90a is a power ON/OFF button. A second button 90b is used to temporarily stop the body 1 when simply pressed, and to end the automatic traveling when pressed simultaneously with a function button 90g. A third button 90c is used to increase the speed of the body 1 when simply pressed, and to cause the body 1 to travel slowly forward when pressed simultaneously with the function button 90g. A fourth button 90d is used to decrease the speed of the body 1 when simply pressed, and to cause the body 1 to travel slowly rearward when pressed simultaneously with the function button 90g. A fifth button 90e is used to start automatic travel when pressed simultaneously with the function button 90g. A sixth button 90f is used to start planting work when pressed simultaneously with the function button 90g. A first indicator 90x indicates the battery level, and changes in display color from green to red when the battery level is low. A second indicator 90y indicates when communication is being performed or not.
[0075] The following describes a procedure of seedling replenishment processing performed using remote control operations in the case where seedling replenishment is required during seedling planting work in back-and-forth straight travel.
(1) In back-and-forth travel in the inward region, the body 1 is temporarily stopped at the planting end position at the end of the straight route, before starting turning travel toward the next straight route. Seedling replenishment processing is started at the timing when the front portion of the body 1 reaches an orientation facing the ridge where seedling replenishment is to be performed.
(2) First, when the operator simultaneously presses the function button 90g and the third button 90c of the remote controller 90, the body 1 travels slowly forward along an extension line of the straight route toward the ridge instead of traveling along the turning route.
(3) At the same time, the boundary-cross permission command unit 56d gives a boundary-cross permission command to the boundary-cross permission unit 56c, and the boundary is extended.
(4) When the front end of the body 1 has approached the ridge, the operator stops pressing the function button 90g and the third button 90c, and thus stops the body 1.
(5) An appropriate number of seedling boxes are loaded into the backup seedling frame 17 (seedling replenishment is completed).
(6) Next, when the operator simultaneously presses the function button 90g and the fifth button 90e of the remote controller 90, post-seedling-replenishment automatic travel is started.
(7) In this post-seedling-replenishment automatic travel, the body 1 moves in reverse along an extension line of the straight route and returns to the planting end position at the end of the straight route where the seedling replenishment processing was started.
(8) After the body 1 has returned to the planting end position, automatic travel along a back-and-forth travel route is resumed, and the body 1 starts to turn along the target turning route.
(9) At the same time, the boundary-cross permission command given by the boundary-cross permission command unit 56d is canceled, and the extended boundary returns to the original position.
[0076] In seedling replenishment, the front portion of the body 1 needs to approach the ridge, but in chemical replenishment or the like, the rear portion of the body 1 needs to approach the ridge. The following describes a procedure of seedling replenishment processing performed using remote control operations in the case where seedling replenishment is required during seedling planting work in back-and-forth straight travel.
(1) In back-and-forth travel in the inward region, the body 1 temporarily stops at the planting start position at the beginning of a straight route when entering the straight route from a turning route. Seedling replenishment processing is started at the timing when the rear portion of the body 1 reaches an orientation facing the ridge where seedling replenishment is to be performed.
(2) First, when the operator simultaneously presses the function button 90g and the fourth button 90d of the remote controller 90, the body 1 travels slowly rearward along an extension line of the straight route toward the ridge.
(3) At the same time, the boundary-cross permission command unit 56d gives a boundary-cross permission command to the boundary-cross permission unit 56c, and the boundary is extended.
(4) When the rear end of the body 1 has approached the ridge, the operator stops pressing the function button 90g and the fourth button 90d, and thus stops the body 1.
(5) Chemical replenishment is performed (chemical replenishment is completed).
(6) Next, when the operator simultaneously presses the function button 90g and the fifth button 90e of the remote controller 90, post-chemical-replenishment automatic travel is started.
(7) In this post-chemical-replenishment automatic travel, the body 1 travels forward along an extension line of the straight route and returns to the planting start position at the beginning of the straight route where the chemical replenishment processing was started.
(8) After the body 1 has returned to the planting start position, automatic travel along a back-and-forth travel route is resumed, the seedling planting device 3 is lowered, and the body 1 starts to perform seedling planting work on the straight route.
(9) At the same time, the boundary-cross permission command given by the boundary-cross permission command unit 56d is canceled, and the extended boundary returns to the original position.
[0077] The traveling of the body 1 is controlled using the remote controller 90 during seedling replenishment work and chemical replenishment work described above, but the body 1 can be controlled manually by the monitor sitting in the driver seat 16 during manned automatic traveling. In this case, instead of using the buttons on the remote controller 90, control is performed using operation functions assigned to buttons displayed on a touch panel of the general-purpose terminal 9 and operation tools such as the driving mode switching operation tool 24.
[0078] Variations of First Embodiment
(1) In the above embodiment, when the boundary-cross permission command is output from the boundary-cross permission command unit 56d, the boundary-cross permission unit 56c extends the boundary by a predetermined value that has been set in advance. The predetermined value may be changed depending on the field condition and environmental conditions such as the weather. Also, the extension of the boundary may be limited to the peripheral region of the body 1, or the entire boundary may be extended. Moreover, as mentioned at the beginning, extending the concept of boundary extension to infinity leads to the disabling of the boundary. Accordingly, the boundary-cross permission command in the above embodiment includes an extension command for extending the boundary toward the boundary object and a disable command for disabling the boundary.
(2) In the above embodiment, the field map creation unit 92, the travel route generation unit 93, and the boundary calculation unit 94 are configured in the general-purpose terminal 9, but may be configured in the control device 60 or may be configured in an external management computer that can exchange data with the control device 100.
(3) During control by the automatic travel control unit 6A, the steering angle on a turning route may be controlled so as to follow a generated turning route, or may be controlled using a steering angle determined in advance so as to achieve a predetermined turning route.
(4) In the above embodiment, a rice transplanter is adopted as the agricultural work vehicle, but the agricultural work vehicle may be a combine harvester, a tractor, a direct seeding machine, a spraying (dispersion) management machine, or the like.
[0079] Note that the configurations disclosed in the above embodiment (including the variations, which shall similarly apply hereinafter) can be applied in combination with configurations disclosed in other embodiments as long as no contradiction arises; the embodiments disclosed in the present specification are examples; and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.
[0080] Second Embodiment
The following describes a riding rice transplanter as an example of an embodiment of an agricultural work vehicle according to the present invention. This rice transplanter can automatically travel on the surface of a field that is bounded by boundary objects. Note that in the present specification, unless specified otherwise, “front” means the front side in the front-rear direction of the body of the rice transplanter (traveling direction), and “rear” means the rear side in the front-rear direction of the body of the rice transplanter (traveling direction). Also, the left-right direction and the lateral direction mean the transverse direction of the body (body width direction) that is orthogonal to the front-rear direction of the body. Also, the terms “up” and “down” are in a positional relationship along the perpendicular direction of the vehicle body (vertical direction), and indicate a relationship regarding ground height.
[0081] FIG. 10 is a side view of the rice transplanter. The rice transplanter includes a riding type of four-wheel-drive travel body (hereinafter called the body 101). The body 101 includes a parallel quadruple link type of link mechanism 111 that is coupled to the rear portion of the body 101 so as to be able to swing up and down, a hydraulic lift cylinder 111a that drives the link mechanism 111 to swing, a seedling planting device 103 (an example of an agricultural material dispensing device) as an example of a work device that is rollably coupled to a rear end portion of the link mechanism 111, and a fertilizer application device 104 that extends from a rear end portion of the body 101 to the seedling planting device 103, for example.
[0082] The body 101 includes wheels 112, an engine 113, and a hydraulic continuously variable transmission 114 as mechanisms for traveling. The wheels 112 include left and right front wheels 112A that can be steered and left and right rear wheels 112B that cannot be steered. The engine 113 and the continuously variable transmission 114 are arranged in a front portion of the body 101. Motive power is supplied from the engine 113 to the front wheels 112A, the rear wheels 112B, and the like via the continuously variable transmission 114 and the like.
[0083] The seedling planting device 103 is configured as a 8-row planting type of device, for example. The seedling planting device 103 includes a seedling stand 131, planting mechanisms 132 corresponding to eight rows, and the like. Note that the seedling planting device 103 can be changed to two-row planting, four-row planting, six-row planting, and the like by controlling row clutches (not shown).
[0084] The seedling stand 131 is a platform on which seedlings for eight rows are placed in a mat. The seedling stand 131 moves back and forth in the left-right direction with a certain stroke that corresponds to the left-right width of the seedling mat, and each time the seedling stand 131 reaches the left and right stroke ends, a vertical feed mechanism 133 vertically feeds seedlings in the mat on the seedling stand 131 toward the lower end of the seedling stand 131 at a predetermined pitch. The eight planting mechanisms 132 are rotary-type mechanisms, and are arranged in the left-right direction at regular intervals corresponding to the spaces between the planting rows. Using motive power from the body 101, each planting mechanism 132 cuts one seedling from the lower end of the seedling mat placed on the seedling stand 131, and plants the cut seedling in a leveled mud region.
[0085] The seedling planting device 103 includes a seedling amount adjusting function for adjusting the amount of seedlings that are to be fed by the planting mechanisms 132. Each planting mechanism 132 feeds and plants a seedling for one plant through a seedling feed port formed in a guide rail that guides the sliding of the lower end of the seedling stand 131. The amount of seedlings is adjusted by changing the vertical positions of the seedling stand 131 and the guide rail that guides the sliding of the lower end of the seedling stand 131.
[0086] As shown in FIG. 10, the fertilizer application device 104 includes a wide hopper 141, feeding mechanisms 142, an electric blower 143, a plurality of fertilizer application hoses 144, and a furrow maker 145 provided for each row. The hopper 141 stores granular or powdered fertilizer. The feeding mechanisms 142 are operated by motive power transmitted from the engine 113, and feed out a predetermined amount of fertilizer for two rows from the hopper 141. The fertilizer application device 104 has a feeding amount adjusting function for changing the amount of fertilizer that is fed by the feeding mechanisms 142.
[0087] The blower 143 is operated by electric power from a battery (not shown) provided in the body 101, and generates transport wind for transporting fertilizer delivered by the feeding mechanisms 142 toward the mud surface of the field. By starting/stopping the operation of the blower 143 or the like, the fertilizer application device 104 can switch between an operating state in which a predetermined amount of fertilizer stored in the hopper 141 is supplied to the field and a non-operating state in which the supply is stopped.
[0088] The fertilizer application hoses 144 guide the fertilizer transported by the transport wind to corresponding furrow makers 145. Each furrow maker 145 is arranged on a leveling float 115. The furrow makers 145 move up and down together with the leveling floats 115 to form fertilizer furrows in mud regions of a paddy field and guide the fertilizer into the fertilizer furrows while the work vehicle travels with the leveling float 115 in contact with the ground.
[0089] The body 101 includes a driver section 120 on the rear portion side. The driver section 120 includes manual travel operation tools such as a steering wheel 121 for steering the front wheels, a main shift lever 122 for adjusting the vehicle speed by performing shift operation of the continuously variable transmission 114, an auxiliary shift lever 123 that enables shift operation of an auxiliary transmission device, and a work operation instrument 125 constituted by a manual operation tool that enables the raising and lowering of the seedling planting device 103 and the switching of the operating state of the same, for example. Also, a general-purpose terminal 109 is provided in front of a driver seat 116. The general-purpose terminal 109 includes a notification device that displays various types of information and gives notifications to the operator, and a touch panel that accepts the input of various types of information. Also, a backup seedling frame 117 for accommodating backup seedlings is provided in front of the driver section 120.
[0090] The steering wheel 121 is coupled to the front wheels 112A via a steering mechanism (not shown), and the steering angle of the front wheels 112A is adjusted by rotating the steering wheel 121. A steering motor M11 is also coupled to the steering mechanism, and, during automatic traveling, the steering angle of the front wheels 112A is adjusted by the steering motor M11 operating based on a steering signal. A shift operation motor M12 for automatically operating the main shift lever 122 is also provided, and, during automatic traveling, the shift position of the continuously variable transmission 114 is adjusted by the shift operation motor M12 operating based on a shifting signal.
[0091] An extension frame 117a that extends upward is provided on an upper portion of the backup seedling frame 117. The extension frame 117a has attached thereto a tower lamp 118 in which a plurality of color lamps for notifying the state of the rice transplanter are arranged in the vertical direction, and a positioning unit 108. The positioning unit 108 outputs positioning data for calculating the position and direction (body direction) of the body 101. The positioning unit 108 includes a satellite positioning module 108A that receives radio waves from satellites in the Global Navigation Satellite System (GNSS) and an inertial measurement unit 108B that detects the tilt and acceleration of the body 101 in three axes.
[0092] FIG. 11 shows an example of a processing procedure in which the rice transplanter performs seedling planting work by a combination of automatic traveling and manual traveling. This processing procedure includes work pre-processing #A1, map creation processing #B1, boundary calculation processing #C1, route generation processing #D1, work start point guidance processing #E1, inward back-and-forth planting processing #F1, and peripheral planting processing #H1. Note that the term “straight” in the present invention does not strictly mean traveling in a completely straight line, but also includes traveling in a large curve and meandering.
[0093] In the work pre-processing #A1, a communication check is performed regarding communication between the units of the control system of the rice transplanter, and a communication check is performed for the positioning unit 108, for example. Also, since the rice transplanter can be remotely controlled using a remote controller 190 (see FIG. 10) and performs obstacle detection using obstacle detectors 180 (see FIG. 12), function checks are also performed for the remote controller 190 and the obstacle detectors 180 in pre-processing. As shown in FIG. 12, the obstacle detectors 180 in the embodiment are sonar-type detectors, and include four front sonar devices 180f whose detection ranges are regions in front of the body 101, two side sonar devices 180s whose detection ranges are regions on the left and right of the body 101, and two rear sonar devices 180r whose detection ranges are regions in front of the body 101.
[0094] The map creation processing #B1 is processing for creating a map of the field targeted for work, that is to say measures the outer shape of the field surface. As shown in FIG. 13, a travel path (teaching travel path) is calculated based on position signals from the positioning unit 108 obtained when the rice transplanter is manually driven along a boundary object such as a ridge that bounds the field surface, that is to say along the outermost periphery of the field surface (map creation teaching traveling). Field contour lines serving as map information regarding the field surface (i.e., a field map) is generated based on the travel path.
[0095] As shown in FIG. 13, the boundary calculation processing #C1 is processing for calculating, based on the travel path calculated in the map creation processing #B1, a boundary that indicates the limit of positions of the body 101 for the rice transplanter to avoid contact with a boundary object in the field. In normal traveling of the rice transplanter, the rice transplanter does not come into contact with a boundary object such as a ridge unless the position of the body 101 crosses the boundary (also called a cross-border line). When the position of the body 101 reaches the boundary, the body 101 is forcibly stopped. When the final boundary position is determined, a safety distance is added such that the rice transplanter does not come into contact with a boundary object such as a ridge even if unexpected slipping or steering wobbling occurs.
[0096] In the route generation processing #D1, a travel route serving as an automatic traveling target set in a field defined by the field map created in the map creation processing #B1 is created using a predetermined algorithm. A travel route generated for seedling planting work performed by automatic traveling will be described below.
[0097] As shown in FIG. 13, the field surface defined by the field map is divided into a peripheral region and an inward region as a result. The generated travel route includes a loop travel route set in the peripheral region (see FIG. 14) and a back-and-forth travel route set in the inward region (see FIG. 15). A work start point guiding route (see FIG. 15) is also set on one side of the peripheral region. The rice transplanter first performs seedling planting work in the inward region while traveling along the back-and-forth travel route (hereinafter called an “inward work travel mode”), and then performs seedling planting work in the peripheral region while traveling along the loop travel route (hereinafter called a “loop work travel mode”).
[0098] The loop travel route shown in FIG. 14 is made up of loop straight routes that extend parallel to a field boundary object (ridge) and direction change routes that involve forward travel and reverse travel to connect loop straight routes to each other. In FIG. 14, the reference sign R11 is assigned to loop straight routes, and the reference sign R12 is assigned to direction change routes. The back-and-forth travel route shown in FIG. 15 is made up of a large number of straight routes that are substantially parallel to each other and turning routes (U-turn routes) that connect straight routes to each other. In FIG. 15, R13 is assigned to straight routes, and the reference sign R15 is assigned to turning routes. In each straight route, the planting of seedlings is started at a work start point, which is the point at which planting work is started, and the planting of seedlings is ended at a work end point (also the turning start position), which is the point at which planting work is ended along the straight route. In FIG. 15, the reference sign WS1 is assigned to the work start point, which is the start position of the planting work in the inward region, and the reference sign WE1 is assigned to the planting end point, which is the end position of the planting work in the inward region. Also, FIG. 15 shows a work start point guiding route (assigned the reference sign R16 in FIG. 15) for traveling from the standby position of the rice transplanter near the entrance/exit to the work start point, which is the travel start position of a back-and-forth travel route.
[0099] In the work start point guidance processing #E1, after map creation teaching traveling has ended and the rice transplanter has stopped at a standby position in the vicinity of the entrance/exit, the rice transplanter automatically travels to the travel start position along the work start point guiding route, which is a travel route to the travel start position, which is the start point of seedling planting work. At that time, automatic traveling along the work start point guiding route (work start point guiding travel) is permitted if the condition that the rice transplanter body 101 at the standby position is facing a specified direction at a predetermined specified position is satisfied.
[0100] In the inward back-and-forth planting processing #F1, the travel mode is set to the inward work travel mode, the rice transplanter automatically travels along the back-and-forth travel route shown in FIG. 15, and automatic travel work (seedling planting work) in the inward region is performed from the work start point to the planting end point by repeatedly traveling forward (work travel) and turning (non-work travel). Note that if the field is large, the seedling replenishment processing #G1 is included in the inward back-and-forth planting processing.
[0101] When the inward back-and-forth planting processing #F1 ends at the planting end point, the traveling mode is set to the loop work travel mode, and the peripheral planting processing #H, which is processing for performing automatic travel work (seedling planting work) in the peripheral region along the loop travel route shown in FIG. 14, is executed. In this embodiment, the loop travel route includes an inner loop travel route for first traveling along a full inward loop, and an outer loop travel route for subsequently traveling along a full outward loop. Basically, since the end position of the outer loop travel route is the entrance/exit of the field, after performing seedling planting work along the outer loop travel route, the rice transplanter exits the field through the entrance/exit. Seedling planting work along the inner loop travel route is performed by traveling automatically. Seedling planting work along the outer loop travel route requires precise traveling, and therefore even if automatic traveling is performed, it is preferable that manned automatic traveling is performed in which a driver is on board as a monitor.
[0102] In the travel route patterns shown in FIGS. 14 and 15, the planting end point of a back-and-forth travel route, the start point of a loop travel route, and the end point of a loop travel route are located near the entrance/exit of the field. It is better if the number of straight routes in the back-and-forth travel route is even, but if the number of straight routes is odd, the planting end point of the back-and-forth travel route is on the side opposite to the entrance/exit. To avoid a problem, as shown in FIG. 16, a straight route other than the final straight route (assigned the reference sign Ln in FIG. 16), such as the straight route denoted by the reference sign Ln-1 in FIG. 16, is traveled without performing work (without performing seedling planting work), then the next straight route (the final straight route denoted by reference sign Ln in FIG. 16) is traveled, and then seedling planting work is performed while traveling on the straight route on which work was not performed. As a result, the planting end point of the final straight route is switched to the entrance/exit side. In the example of FIG. 16, the position of the planting end point moves by an amount corresponding to the planting width. To avoid this, another straight route may be selected as the non-work straight route.
[0103] Since the outer loop travel route is created so as to match the travel path in the map creation teaching traveling, the body 101 will not come into contact with a ridge or the like as long as it travels while accurately following the outer loop travel route. However, whereas the body 101 travels with the seedling planting device 103 in the raised state in the map creation teaching traveling, the body 101 travels with the seedling planting device 103 in the raised state while traveling on the outer loop travel route. For this reason, depending on the position of the body 101, if the seedling planting device 103 is lowered at the start of traveling on the outer loop travel route, the seedling planting device 103 may possibly come into contact with a ridge. In order to avoid this, in the traveling on the outer loop travel route, traveling is automatically paused at a position before transitioning to work travel, and the driver checks whether the seedling planting device 103 can be safely lowered. During the automatic pause, the seedling planting device 103 is in the raised state.
[0104] With reference to FIG. 17, the following describes an example of lowering safety check control, which includes automatic pausing, a lowering safety check performed by the driver, and the start of the automatic work travel after safety confirmation. In FIG. 17, before the body 101 enters the field corner, at a point P11, the seedling planting device 103 is raised, and direction change traveling is performed by automatic traveling without performing work. The direction change traveling is performed using, as travel targets, a straight travel route R121 from the point P11 to a point P12, and a reverse turning travel route R122 from the point P12 to a point P13. At the point P13, the next loop straight route following the outer loop travel route has been acquired, and thus automatic work travel can be performed with the seedling planting device 103 in the lowered state, but at point P13, the body 101 is temporarily stopped. In this automatic pause state, a notification is given to request that the driver determine whether the seedling planting device 103 can be safely lowered. If the driver determines that there is no problem, the driver performs an operation for lowering the seedling planting device 103 (a work device lowering operation that is an example of a pre-commencement operation, which is an operation performed before the start of automatic travel). Due to this operation, the start of automatic work travel is permitted.
[0105] This lowering safety check control is executed in a region where an outer loop travel route has been set, when transitioning from non-work travel with the seedling planting device 103 in the raised state (may be automatic traveling or manual traveling) to automatic work travel with the seedling planting device 103 in the lowered state.
[0106] Next, with reference to FIG. 18, the following describes an example of lowering safety check control executed in a region other than a region where an outer loop travel route has been set. FIG. 18 shows lowering safety check control performed on an obstacle avoidance travel route for avoiding a travel obstacle located in a straight route of the back-and-forth travel route in the inward region. When the automatic straight work travel, which is bound for a straight route in the back-and-forth travel route, is performed up to a point Q11 in front of a travel obstacle, the seedling planting device 103 is raised, then reverse turning traveling is performed up to a point Q12 using a reverse turning travel route R131, which is non-work automatic traveling, and then forward turn traveling is performed to a point Q13 using a forward turning travel route R132. At the point Q13, the next straight route is acquired, and thus automatic work travel with the seedling planting device 103 in the lowered state can be started, but the body 101 is temporarily stopped at the point Q13. In this automatic pause state, a notification is given to request that the driver determine whether or not the lowered seedling planting device 103 would come into contact with the travel obstacle if automatic work travel were carried out in the current state. If the driver determines that there is no problem, the driver performs an operation for lowering the seedling planting device 103 (pre-commencement operation). Due to this operation, the start of automatic work travel is permitted.
[0107] FIG. 19 shows a control block diagram of the control system of the rice transplanter. The control system of the rice transplanter includes a control device 160 that controls various operations of the rice transplanter, a general-purpose terminal 109 that can exchange data with the control device 160, and a remote controller 190. Signals from a positioning unit 108, a work operation instrument 125, a travel sensor group 128, a work sensor group 129, and obstacle detectors 180 are input to the control device 160. Control signals from the control device 160 are output to a travel device group 101A and a work device group 101B.
[0108] The travel device group 101A includes, for example, a steering motor M11 and a shift operation motor M12, and the control device 160 outputs control signals to control the steering motor M11 to adjust the steering angle and to control the shift operation motor M12 to adjust the vehicle speed.
[0109] The work device group 101B includes, for example, a lift cylinder 111a for raising and lowering the seedling planting device 103, a seedling amount adjuster for adjusting the amount of seedlings to be fed by the planting mechanisms 132, and a feeding amount adjuster for adjusting the amount of fertilizer feed by the feeding mechanisms 142.
[0110] The travel sensor group 128 includes various sensors that detect states of the steering angle, the vehicle speed, the engine speed, and the like, as well as set values for the same. The work sensor group 129 includes various sensors that detect states of the link mechanism 111, the seedling planting device 103, and the fertilizer application device 104.
[0111] The control device 160 includes a travel control unit 106, a work control unit 151, a body position calculation unit 152, a travel route management unit 153, a driving control state detection unit 155, an automatic work travel management unit 156, an input signal processing unit 150a, and a communication unit 150b.
[0112] The general-purpose terminal 109, which is connected to the control device 160 via an in-vehicle LAN, includes a field information storage unit 191, a field map creation unit 192, a travel route generation unit 193, a boundary calculation unit 194, and a travel path generation unit 195. The field information storage unit 191 stores information regarding the field, such as the planted seed, the entrance (exit) position of the field, and the position where seedlings can be replenished. The field map creation unit 192 performs the map creation processing described with reference to FIG. 11.
[0113] The travel route generation unit 193 divides the field into a peripheral region and an inward region based on the field map created by the field map creation unit 192, and generates a loop travel route for traveling in the peripheral region and a back-and-forth travel route for the inward region. An outer loop travel route in the loop travel route is created using the travel path in the map creation teaching traveling. Also, if a travel obstacle is detected in the field in the map creation teaching traveling, the travel route generation unit 193 also creates a travel route for avoiding the travel obstacle.
[0114] The boundary calculation unit 194 performs the boundary calculation processing described with reference to step #C1 in FIG. 11. The map creation processing performed by the field map creation unit 192 and the boundary calculation processing performed by the boundary calculation unit 194 require the travel path in map creation teaching traveling. The travel path generation unit 195 generates a travel path for the body 101 based on the body positions calculated by the body position calculation unit 152.
[0115] The input signal processing unit 150a processes signals from various sensors, switches, levers, and the like provided in the rice transplanter, and transfers the processed signals to function units configured in the control device 160. The communication unit 150b has a wireless communication function, performs data communication with an external device such as the remote controller 190, and transfers received data to the input signal processing unit 150a.
[0116] The travel control unit 106 includes an automatic travel control unit 106A, a manual travel control unit 106B, and a control management unit 106C. The automatic travel control unit 106A performs speed control and steering control in automatic traveling. Lateral deviation and directional deviation are calculated based on the body position and the target travel route set by the travel route management unit 153, and steering control is performed so as to reduce the lateral deviation and the directional deviation.
[0117] In automatic traveling, the work control unit 151 automatically controls the work device group 101B based on a program given in advance, whereas in manual traveling, the work control unit 151 controls the work device group 101B based on operations performed by the driver. Note that in the lowering safety check control described above, in the automatic travel mode, the seedling planting device 103 is lowered by an operation performed by the driver using the work operation instrument 125.
[0118] The body position calculation unit 152 calculates map coordinates (the body position) of the body 101 based on satellite positioning data sequentially transmitted by the positioning unit 108. The travel route management unit 153 receives the various travel routes generated by the travel route generation unit 193 from the general-purpose terminal 109 and manages the received travel routes, and also sequentially sets target travel routes for steering the body in the automatic travel mode.
[0119] The driving control state detection unit 155 detects travel control states and work control states based on control information handled by the control device 160. In particular, the driving control state detection unit 155 detects an automatic pause according to which the body stops before a transition from non-work travel with the seedling planting device 103, which is a working device, in the raised state to automatic work travel with the seedling planting device 103 in the lowered state. This automatic pause is detected based on the travel route on which the body 101 is traveling, the body position, and detection signals from the travel sensor group 128 and the work sensor group 129.
[0120] When an automatic pause is detected by the driving control state detection unit 155, the automatic work travel management unit 156 determines whether or not an automatic work travel condition, which is for shifting from the automatic pause state to automatic work travel, has been satisfied. The automatic work travel start condition includes the conditions that: various signals required for automatic work travel have been input to the control device 160; the travel route for automatic work travel has been acquired; and an operation for lowering the seedling planting device 103 (an example of a pre-commencement operation) has been performed by the driver on the work operation instrument 125 as a pre-commencement operation.
[0121] Also, when an automatic pause is detected, the automatic work travel management unit 156 gives a notification for requesting the driver to perform a safety check and operate the work operation instrument 125 so as to lower the seedling planting device 103. This notification is given using a speaker, the display the general-purpose terminal 109, or the like.
[0122] Variations of Second Embodiment
(1) In the above embodiment, the pre-commencement operation is an operation performed on the work operation instrument 125 for lowering the seedling planting device 103, but may be another operation performed regarding the seedling planting device 103, such as a row clutch operation. Another example of a pre-commencement operation is an operation for changing the travel route in order to change the lowered position of the seedling planting device 103. If it is not necessary to change the lowered position of the seedling planting device 103, an operation that does not require changing the travel route is performed as the pre-commencement operation. The pre-commencement operation that serves as an operation confirming that there is no problem with the lowered position of the work device may be an input operation performed on the touch panel of the general-purpose terminal 109.
(2) In the above embodiment, the field map creation unit 192, the travel route generation unit 193, the boundary calculation unit 194, and the travel path generation unit 195 are configured in the general-purpose terminal 109, but at least some of such units may be configured in the control device 160 or may be configured in an external management computer that can exchange data with the control device 160. On the other hand, the automatic work travel management unit 156 and the driving control state detection unit 155 may be configured in the general-purpose terminal 109.
(3) During control by the automatic travel control unit 106A, the steering angle on a turning route may be controlled so as to follow a generated turning route, or may be controlled using a steering angle determined in advance so as to achieve a predetermined turning route.
(4) In the above embodiment, a rice transplanter is adopted as the agricultural work vehicle, but the agricultural work vehicle may be a fertilizer distributer, a tractor, a direct seeding machine, a spraying (dispersion) management machine, or the like.
[0123] Note that the configurations disclosed in the above embodiment (including the variations, which shall similarly apply hereinafter) can be applied in combination with configurations disclosed in other embodiments as long as no contradiction arises; the embodiments disclosed in the present specification are examples; and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.
[0124] Third Embodiment
The following describes a riding rice transplanter as an example of an embodiment of an agricultural work vehicle according to the present invention. This rice transplanter can automatically travel on the surface of a field that is bounded by boundary objects. Note that in the present specification, unless specified otherwise, “front” means the front side in the front-rear direction of the body of the rice transplanter (traveling direction), and “rear” means the rear side in the front-rear direction of the body of the rice transplanter (traveling direction). Also, the left-right direction and the lateral direction mean the transverse direction of the body (body width direction) that is orthogonal to the front-rear direction of the body. Also, the terms “up” and “down” are in a positional relationship along the perpendicular direction of the vehicle body (vertical direction), and indicate a relationship regarding ground height.
[0125] FIG. 20 is a side view of the rice transplanter. The rice transplanter includes a riding type of four-wheel-drive travel body (hereinafter called the body 201). The body 201 includes a parallel quadruple link type of link mechanism 211 that is coupled to the rear portion of the body 201 so as to be able to swing up and down, a hydraulic lift cylinder 211a that drives the link mechanism 211 to swing, a seedling planting device 203 (an example of an agricultural material dispensing device) that is rollably coupled to a rear end portion of the link mechanism 211, and a fertilizer application device 204 that extends from a rear end portion of the body 201 to the seedling planting device 203, for example.
[0126] The body 201 includes wheels 212, an engine 213, and a hydraulic continuously variable transmission 214 as mechanisms for traveling. The wheels 212 include left and right front wheels 212A that can be steered and left and right rear wheels 212B that cannot be steered. The engine 213 and the continuously variable transmission 214 are arranged in a front portion of the body 201. Motive power is supplied from the engine 213 to the front wheels 212A, the rear wheels 212B, and the like via the continuously variable transmission 214 and the like.
[0127] The seedling planting device 203 is configured as an eight-row planting type of device, for example. The seedling planting device 203 includes a seedling stand 231, planting mechanisms 232 corresponding to eight rows, and the like. Note that the seedling planting device 203 can be changed to two-row planting, four-row planting, six-row planting, and the like by controlling row clutches (not shown).
[0128] The seedling stand 231 is a platform on which seedlings for eight rows are placed in a mat. The seedling stand 231 moves back and forth in the left-right direction with a certain stroke that corresponds to the left-right width of the seedling mat, and each time the seedling stand 231 reaches the left and right stroke ends, a vertical feed mechanism 233 vertically feeds seedlings in the mat on the seedling stand 231 toward the lower end of the seedling stand 231 at a predetermined pitch. The eight planting mechanisms 232 are rotary-type mechanisms, and are arranged in the left-right direction at regular intervals corresponding to the spaces between the planting rows. Using motive power from the body 201, each planting mechanism 232 cuts one seedling from the lower end of the seedling mat placed on the seedling stand 231, and plants the cut seedling in a leveled mud region.
[0129] The seedling planting device 203 includes a seedling amount adjusting function for adjusting the amount of seedlings that are to be fed by the planting mechanisms 232. Each planting mechanism 232 feeds and plants a seedling for one plant through a seedling feed port formed in a guide rail that guides the sliding of the lower end of the seedling stand 231. The amount of seedlings is adjusted by changing the vertical positions of the seedling stand 231 and the guide rail that guides the sliding of the lower end of the seedling stand 231.
[0130] As shown in FIG. 20, the fertilizer application device 204 includes a wide hopper 241, feeding mechanisms 242, an electric blower 243, a plurality of fertilizer application hoses 244, and a furrow maker 245 provided for each row. The hopper 241 stores granular or powdered fertilizer. The feeding mechanisms 242 are operated by motive power transmitted from the engine 213, and feed out a predetermined amount of fertilizer for two rows from the hopper 241. The fertilizer application device 204 has a feeding amount adjusting function for changing the amount of fertilizer that is fed by the feeding mechanisms 242.
[0131] The blower 243 is operated by electric power from a battery (not shown) provided in the body 201, and generates transport wind for transporting fertilizer delivered by the feeding mechanisms 242 toward the mud surface of the field. By starting/stopping the operation of the blower 243 or the like, the fertilizer application device 204 can switch between an operating state in which a predetermined amount of fertilizer stored in the hopper 241 is supplied to the field and a non-operating state in which the supply is stopped.
[0132] The fertilizer application hoses 244 guide the fertilizer transported by the transport wind to corresponding furrow makers 245. Each furrow maker 245 is arranged on a leveling float 215. The furrow makers 245 move up and down together with the leveling floats 215 to form fertilizer furrows in mud regions of a paddy field and guide the fertilizer into the fertilizer furrows while the work vehicle travels with the leveling float 215 in contact with the ground.
[0133] The body 201 includes a driver section 220 on the rear portion side. The driver section 220 includes manual travel operation tools such as a steering wheel 221 for steering the front wheels, a main shift lever 222 for adjusting the vehicle speed by performing shift operation of the continuously variable transmission 214, an auxiliary shift lever 223 that enables shift operation of an auxiliary transmission device, and a work operation lever 225 that enables the raising and lowering of the seedling planting device 203 and the switching of the operating state of the same, for example. Also, a general-purpose terminal 209 is provided in front of a driver seat 216. The general-purpose terminal 209 includes a notification device that displays various types of information and gives notifications to the operator, and a touch panel that accepts the input of various types of information. A driving mode switching operation tool 224 for operation by the driver is provided in the vicinity of the steering wheel 221. Also, a backup seedling frame 217 for accommodating backup seedlings is provided in front of the driver section 220.
[0134] The steering wheel 221 is coupled to the front wheels 212A via a steering mechanism (not shown), and the steering angle of the front wheels 212A is adjusted by rotating the steering wheel 221. A steering motor M21 is also coupled to the steering mechanism, and, during automatic traveling, the steering angle of the front wheels 212A is adjusted by the steering motor M21 operating based on a steering signal. A shift operation motor M22 for automatically operating the main shift lever 222 is also provided, and, during automatic traveling, the shift position of the continuously variable transmission 214 is adjusted by the shift operation motor M22 operating based on a shifting signal.
[0135] An extension frame 217a that extends upward is provided on an upper portion of the backup seedling frame 217. The extension frame 217a has attached thereto a tower lamp 218 in which a plurality of color lamps for notifying the state of the rice transplanter are arranged in the vertical direction, and a positioning unit 208. The positioning unit 208 outputs positioning data for calculating the position and direction (body direction) of the body 201. The positioning unit 208 includes a satellite positioning module 208A that receives radio waves from satellites in the Global Navigation Satellite System (GNSS) and an inertial measurement unit 208B that detects the tilt and acceleration of the body 201 in three axes.
[0136] FIG. 21 shows an example of a processing procedure in which the rice transplanter performs seedling planting work by a combination of automatic traveling and manual traveling. This processing procedure includes work pre-processing #A2, map creation processing #B2, boundary calculation processing #C2, route generation processing #D2, work start point guidance processing #E2, inward back-and-forth planting processing #F2, and peripheral planting processing #H2. Note that if the field is large, the seedling replenishment processing #G2 is included in the inward back-and-forth planting processing.
[0137] In the work pre-processing #A2, a communication check is performed regarding communication between the units of the control system of the rice transplanter, and a communication check is performed for the positioning unit 8, for example. Also, since the rice transplanter can be remotely controlled using a remote controller 290 (see FIG. 20) and performs obstacle detection using obstacle detectors 280 (see FIG. 22), function checks are also performed for the remote controller 290 and the obstacle detectors 280 in pre-processing. As shown in FIG. 22, the obstacle detectors 280 in the embodiment are sonar-type detectors, and include four front sonar devices 280f whose detection ranges are regions in front of the body 201, two side sonar devices 280s whose detection ranges are regions on the left and right of the body 201, and two rear sonar devices 280r whose detection ranges are regions in front of the body 201.
[0138] The map creation processing #B2 is processing for creating a map of the field targeted for work, that is to say measures the outer shape of the field surface. As shown in FIG. 23, a travel path (teaching travel path) is calculated based on position signals from the positioning unit 208 obtained when the rice transplanter is manually driven along a boundary object such as a ridge that bounds the field surface, that is to say along the outermost periphery of the field surface (map creation teaching traveling). Field contour lines serving as map information regarding the field surface (i.e., a field map) is generated based on the travel path.
[0139] As shown in FIG. 23, the boundary calculation processing #C2 is processing for calculating, based on the travel path calculated in the map creation processing #B2, a boundary that indicates the limit of positions of the body 201 for the rice transplanter to avoid contact with a boundary object in the field. In normal traveling of the rice transplanter, the rice transplanter does not come into contact with a boundary object such as a ridge unless the position of the body 201 crosses the boundary (also called a cross-border line). When the position of the body 201 reaches the boundary, the body 201 is forcibly stopped. When the final boundary position is determined, a safety distance is added such that the rice transplanter does not come into contact with a boundary object such as a ridge even if unexpected slipping or steering wobbling occurs.
[0140] In the route generation processing #D2, a travel route serving as an automatic traveling target set in a field defined by the field map created in the map creation processing #B2 is created using a predetermined algorithm. A travel route generated for seedling planting work performed by automatic traveling will be described below.
[0141] As shown in FIG. 23, the field surface defined by the field map is divided into a peripheral region and an inward region as a result. The generated travel route includes a loop travel route set in the peripheral region (see FIG. 24) and a back-and-forth travel route set in the inward region (see FIG. 25). Also, the work start point guiding route (see FIG. 25) is also set on one side of the peripheral region. The rice transplanter first performs seedling planting work in the inward region while traveling along the back-and-forth travel route (hereinafter called an “inward work travel mode”), and then performs seedling planting work in the peripheral region while traveling along the loop travel route (hereinafter called a “loop work travel mode”).
[0142] The loop travel route shown in FIG. 24 is made up of loop straight routes that extend parallel to a field boundary object (ridge) and direction change routes that involve forward travel and reverse travel to connect loop straight routes to each other. In FIG. 24, the reference sign R21 is assigned to loop straight routes, and the reference sign R22 is assigned to direction change routes. The back-and-forth travel route shown in FIG. 25 is made up of a large number of straight routes that are substantially parallel to each other and turning routes (U-turn routes) that connect straight routes to each other. In FIG. 25, R23 is assigned to straight routes, and the reference sign R25 is assigned to turning routes. In each straight route, the planting of seedlings is started at a work start point, which is the point at which planting work is started, and the planting of seedlings is ended at a work end point (also the turning start position), which is the point at which planting work is ended along the straight route. Note that in FIG. 25, the reference sign WS2 is assigned to the work start point, which is the start position of the planting work in the inward region, and the reference sign WE2 is assigned to the planting end point, which is the end position of the planting work in the inward region. Also, FIG. 25 shows a work start point guiding route (assigned the reference sign R26 in FIG. 25) for traveling from the standby position of the rice transplanter near the entrance/exit to the work start point, which is the travel start position of a back-and-forth travel route. Note that the term “straight” in the present invention does not strictly mean traveling in a completely straight line, but also includes traveling in a large curve and meandering.
[0143] In the work start point guidance processing #E2, after map creation teaching traveling has ended and the rice transplanter has stopped at a standby position in the vicinity of the entrance/exit, the rice transplanter automatically travels to the travel start position along the work start point guiding route, which is a travel route to the travel start position, which is the start point of seedling planting work. At that time, automatic traveling along the work start point guiding route (work start point guiding travel) is permitted if the condition that the rice transplanter body 201 at the standby position is facing a specified direction at a predetermined specified position is satisfied.
[0144] One permission condition for work start point guiding travel is shown in FIG. 26. In FIG. 26, the body 201 is stopped in a state where the front portion of the body 201 face the work start point, on one side of the peripheral region where the work start point guiding route has been generated. The stop position of the body 201 is a standby position for performing automatic traveling. Here, the permission condition is that the difference between the forward direction of the body 201 and the direction of the work start point guiding route is less than or equal to a predetermined angle difference θ. If the permission condition is satisfied, the body 201 automatically travels from the standby position to the work start point along the work start point guiding route that has been additionally provided with a guide travel route (indicated by dashed lines in FIGS. 26 and 27 and assigned the reference sign FL) that enables entrance to the work start point guiding route.
[0145] Another permission condition for work start point guiding travel is shown in FIG. 27. In FIG. 27, in order to perform seedling replenishment before seedling planting work is performed, the body 201 approaches a ridge so as to abut the front portion of the body 201 against the ridge, and then stops. The stop position of the body 201 is a standby position for performing automatic traveling. In other words, the body 201 does not satisfy the permission condition shown in FIG. 26, which is that the difference between the forward direction of the body 201 and the direction of the work start point guiding route is less than or equal to the predetermined angle difference θ. In the state where the body 201 is in an orientation in which the front portion of the body 201 is abutted against a ridge, the permission condition is that the body 1 is located in an area where automatic driving can be started (assigned the reference sign ADA in FIGS. 26 and 27). The condition that the body 201 is in the automatic driving startable area can be replaced with the condition that the body 201 is located at a predetermined distance or more from the work start point in the peripheral region on the side where the work start point has been set. The rice transplanter frequently becomes located at such a standby position in the case of performing seedling replenishment before seedling planting work, and therefore from this orientation, the guide travel route that guides the body 201 to the work start point guiding route can be made into a standard pattern as a so-called cutback travel route, which includes a combination of rearward movement and forward movement. In consideration of the fact that seedling replenishment is performed in the vicinity of the entrance/exit after the rice transplanter has finished the map creation teaching traveling, the area where automatic driving can be started is set to an area extending for several meters from the entrance/exit toward the work start point in the peripheral region.
[0146] Although not illustrated, in order to perform fertilizer replenishment or chemical replenishment before performing fertilizing or chemical spraying, the permission condition in FIG. 27 can also be applied to the case where the body 201 approaches a ridge such that the rear portion of the body 201 is abutted against the ridge, and then stops. In this case, the guide travel route that guides the body 201 to the work start point guiding route is a forward 90-degree turning route.
[0147] In the inward back-and-forth planting processing #F2, the travel mode is set to the inward work travel mode, the rice transplanter automatically travels along the back-and-forth travel route shown in FIG. 25, and automatic travel work (seedling planting work) in the inward region is performed from the work start point to the planting end point by repeatedly traveling forward (work travel) and turning (non-work travel).
[0148] When the inward back-and-forth planting processing #F2 ends at the planting end point, the traveling mode is set to the loop work travel mode, and the peripheral planting processing #H2, which is processing for performing automatic travel work (seedling planting work) in the peripheral region along the loop travel route shown in FIG. 24, is executed. In this embodiment, the loop travel route includes an inner loop travel route for first traveling along a full inward loop, and an outer loop travel route for subsequently traveling along a full outward loop. Basically, since the end position of the outer loop travel route is the entrance/exit of the field, after performing seedling planting work along the outer loop travel route, the rice transplanter exits the field through the entrance/exit. Seedling planting work along the inner loop travel route is performed by traveling automatically. Seedling planting work along the outer loop travel route requires precise traveling, and therefore even if automatic traveling is performed, it is preferable that manned automatic traveling is performed in which a driver is on board as a monitor.
[0149] In the travel route patterns shown in FIGS. 24 and 25, the planting end point of a back-and-forth travel route, the start point of a loop travel route, and the end point of a loop travel route are located near the entrance/exit of the field. It is better if the number of straight routes in the back-and-forth travel route is even, but if the number of straight routes is odd, the planting end point of the back-and-forth travel route is on the side opposite to the entrance/exit. To avoid a problem, as shown in FIG. 28, a straight route other than the final straight route (assigned the reference sign Ln in FIG. 28), such as the straight route denoted by the reference sign Ln-1 in FIG. 28, is traveled without performing work (without performing seedling planting work), then the next straight route (the final straight route denoted by reference sign Ln in FIG. 28) is traveled, and then seedling planting work is performed while traveling on the straight route on which work was not performed. As a result, the planting end point of the final straight route is switched to the entrance/exit side. In the example of FIG. 28, the position of the planting end point moves by an amount corresponding to the planting width. To avoid this, another straight route may be selected as the non-work straight route.
[0150] FIG. 29 shows a control block diagram of the control system of the rice transplanter. The control system of the rice transplanter includes a control device 260 that controls various operations of the rice transplanter, a general-purpose terminal 209 that can exchange data with the control device 260, and a remote controller 290. Signals from a positioning unit 208, a driving mode switching operation tool 224, a travel sensor group 228, a work sensor group 229, and obstacle detectors 280 are input to the control device 260. Control signals from the control device 260 are output to a travel device group 201A and a work device group 201B.
[0151] The travel device group 201A includes, for example, a steering motor M21 and a shift operation motor M22, and the control device 260 outputs control signals to control the steering motor M21 to adjust the steering angle and to control the shift operation motor M22 to adjust the vehicle speed.
[0152] The work device group 201B includes, for example, a lift cylinder 211a for raising and lowering the seedling planting device 203, a seedling amount adjuster for adjusting the amount of seedlings to be fed by the planting mechanisms 232, and a feeding amount adjuster for adjusting the amount of fertilizer feed by the feeding mechanisms 242.
[0153] The travel sensor group 228 includes various sensors that detect states of the steering angle, the vehicle speed, the engine speed, and the like, as well as set values for the same. The work sensor group 229 includes various sensors that detect states of the link mechanism 211, the seedling planting device 203, and the fertilizer application device 204.
[0154] The control device 260 includes a travel control unit 206, a work control unit 251, a body position calculation unit 252a, a body direction calculation unit 252b, a travel route management unit 253, a driving control state detection unit 255, a boundary-cross management unit 256, a start guide management unit 257, an input signal processing unit 250a, and a communication unit 250b.
[0155] The general-purpose terminal 209, which is connected to the control device 260 via an in-vehicle LAN, includes a field information storage unit 291, a field map creation unit 292, a travel route generation unit 293, a boundary calculation unit 294, and a travel path generation unit 295. The field information storage unit 291 stores information regarding the field, such as the planted seed, the entrance (exit) position of the field, and the position where seedlings can be replenished. The field map creation unit 292 performs the map creation processing described with reference to FIG. 21.
[0156] The travel route generation unit 293 includes a work start point setting unit 293a and a start point guiding route generation unit 293b. The travel route generation unit 293 divides the field into a peripheral region and an inward region based on the field map created by the field map creation unit 292, and generates a loop travel route for traveling in the peripheral region and a back-and-forth travel route for the inward region. The work start point setting unit 293a, which functions as a unit for setting a work start point, sets the start point of the generated back-and-forth travel route as the work start point (planting start point) at which field work by automatic traveling is started. The end point of the generated back-and-forth travel route is the planting end point. Note that a configuration is possible in which the work start point and the planting end point are initially set in the inward region, and a back-and-forth travel route is generated so as to connect the work start point and the planting end point. The start point guiding route generation unit 293b generates a work start point guiding route, which is a travel route for causing the body 201, which is waiting after teaching traveling, to automatically travel to the work start point.
[0157] The boundary calculation unit 294 performs the boundary calculation processing described with reference to step #C2 in FIG. 21. The map creation processing performed by the field map creation unit 292 and the boundary calculation processing performed by the boundary calculation unit 294 require the travel path in map creation teaching traveling. The travel path generation unit 295 generates a travel path for the body 201 based on the body positions calculated by the body position calculation unit 252a.
[0158] The input signal processing unit 250a processes signals from various sensors, switches, levers, and the like provided in the rice transplanter, and transfers the processed signals to function units configured in the control device 260. The communication unit 250b has a wireless communication function, performs data communication with an external device such as the remote controller 290, and transfers received data to the input signal processing unit 250a.
[0159] The travel control unit 206 includes an automatic travel control unit 206A, a manual travel control unit 206B, and a control management unit 206C. The automatic travel control unit 206A performs speed control and steering control in automatic traveling. Lateral deviation and directional deviation are calculated by comparing the target travel route set by the travel route management unit 253 with the body position and the body direction calculated by the body position calculation unit 252a and the body direction calculation unit 252b, and steering control is performed so as to reduce the lateral deviation and the directional deviation.
[0160] In addition to the automatic travel mode of automatically traveling along a target travel route, the rice transplanter includes a straight maintenance driving mode of automatically traveling straight forward so as to maintain the direction of a reference line defined by at least two points. A straight travel route managed by the travel route management unit 253 can be additionally used as the reference line used in the straight maintenance driving mode.
[0161] In a manual driving mode, the manual travel control unit 206B controls the steering motor M21 based on operation of the steering wheel 221. The control management unit 206C selects the automatic travel mode, the straight maintenance driving mode, or the manual driving mode based on a signal from the driving mode switching operation tool 224.
[0162] In automatic traveling, the work control unit 251 automatically controls the work device group 201B based on a program given in advance, whereas in manual traveling, the work control unit 251 controls the work device group 201B based on operations performed by the driver. The body position calculation unit 252a calculates map coordinates (the body position) of the body 201 based on satellite positioning data sequentially transmitted by the positioning unit 208. The body direction calculation unit 252b calculates the direction (traveling direction) of the body 201 from the time series of body positions calculated by the body position calculation unit 252a.
[0163] The travel route management unit 253 receives the various travel routes generated by the travel route generation unit 293 from the general-purpose terminal 209 and manages the received travel routes, and also sequentially sets target travel routes for steering the body in the automatic travel mode.
[0164] The driving control state detection unit 255 detects travel control states and work control states based on control information handled by the control device 260.
[0165] The boundary-cross management unit 256 has a function of avoiding the case where the body 201 comes into contact with a boundary object such as a ridge due to the body 201 crossing the boundary (exceeding the boundary data) calculated by the boundary calculation unit 294. For example, the boundary-cross management unit 256 determines whether or not the body 201 will not cross the boundary based on body position, and gives, to the travel control unit 206, a stop command that prohibits the body 201 from crossing the boundary.
[0166] The start guide management unit 257 determines whether or not the body 201 at the standby position is to be caused to automatically travel to the work start point using the work start point guiding route. In this embodiment, as described above, the conditions for starting automatic travel are: (1) the body 201 is facing the work start point in a region on one side of the peripheral region where the work start point guiding route has been set, and furthermore the difference between the body direction and the direction of the work start point guiding route is less than or equal to the predetermined angle; (2) the front portion or the rear portion of the body 201 is facing a boundary object such as a ridge defining the boundary, and even if the body 201 is in an orientation in which the body direction and the direction of the work start point guiding route are substantially orthogonal to each other, the body 201 is located in an automatic driving startable area; and (3) the body 201 is located in a field targeted for work, the direction of the body 201 corresponds to the direction of the start point guiding route, and the body 201 is on the start point guiding route.
[0167] Note that the conditions for starting automatic traveling are not limited to the above conditions (1), (2), and (3). The condition for starting automatic traveling can be that the standby position of the body 201, which has been stopped in order to start automatic traveling using the work start point guiding route, is facing a specified direction at a specified position that has been set as desired.
[0168] If such an automatic traveling start condition is satisfied, the general-purpose terminal 209 or a speaker or lamp (not shown) is used to give a notification that automatic traveling from the current standby position to the work start point is permitted. In view of this, when the driver performs an operation for starting automatic traveling, automatic traveling performed using the work start point guiding route is started. If the driver performs an operation for starting automatic traveling even though the automatic traveling start condition is not satisfied, a notification is given to indicate that automatic traveling cannot be started at the current standby position, and a position and body direction at which automatic traveling can be started are displayed on the display of the general-purpose terminal 209.
[0169] Variations of Third Embodiment
(1) In the above embodiment, the field map creation unit 292, the travel route generation unit 293, the boundary calculation unit 294, and the travel path generation unit 295 are configured in the general-purpose terminal 209, but at least some of such units may be configured in the control device 260 or may be configured in an external management computer that can exchange data with the control device 260.
(2) During control by the automatic travel control unit 206A, the steering angle on a turning route may be controlled so as to follow a generated turning route, or may be controlled using a steering angle determined in advance so as to achieve a predetermined turning route.
(3) In the above embodiment, a rice transplanter is adopted as the agricultural work vehicle, but the agricultural work vehicle may be a combine harvester, a tractor, a direct seeding body, a spraying (dispersion) management body, or the like.
[0170] Note that the configurations disclosed in the above embodiment (including the variations, which shall similarly apply hereinafter) can be applied in combination with configurations disclosed in other embodiments as long as no contradiction arises; the embodiments disclosed in the present specification are examples; and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

Industrial Applicability
[0171] The present invention is applicable to an agricultural work vehicle that can travel automatically.

Description of Reference Signs
[0172] First Embodiment
1 Body
3 Seedling planting device
4 Fertilizer application device
6 Travel control unit
6A Automatic travel control unit
6B Manual travel control unit
6C Control management unit
8 Positioning unit
9 General-purpose terminal
24 Driving mode switching operation tool
51 Work control unit
52 Body position calculation unit
53 Travel route management unit
54 Travel path generation unit
55 Driving control state detection unit
56 Boundary management unit
56a Boundary storage unit
56b Boundary-cross prevention control unit
56c Boundary-cross permission unit
56d Boundary-cross permission command unit
80 Obstacle detector
90 Remote controller
92 Field map creation unit
93 Travel route generation unit
94 Boundary calculation unit
100 Control device
[0173] Second Embodiment
101 Body
103 Seedling planting device (agricultural material dispensing device, work device)
106 Travel control unit
106A Automatic travel control unit
106B Manual travel control unit
106C Control management unit
108 Positioning unit
125 Work operation instrument
151 Work control unit
152 Body position calculation unit
153 Travel route management unit
155 Driving control state detection unit
156 Automatic work travel management unit
180 Obstacle detector
190 Remote controller
191 Field information storage unit
192 Field map creation unit
193 Travel route generation unit
194 Boundary calculation unit
195 Travel path generation unit
160 Control device
[0174] Third Embodiment
201 Body
201A Travel device group
201B Work device group
203 Seedling planting device
204 Fertilizer application device
206A Automatic travel control unit
208 Positioning unit
208A Satellite positioning module
208B Inertial measurement unit
209 General-purpose terminal
231 Seedling stand
252a Body position calculation unit
252b Body direction calculation unit
253 Travel route management unit
257 Start guide management unit
292 Field map creation unit
293 Travel route generation unit
293a Work start point setting unit
293b Start point guiding route generation unit
295 Travel path generation unit
260 Control device
θ Predetermined angle difference
, Claims:WE CLAIM:

1. An agricultural work vehicle that automatically travels in a field, comprising:
a body position calculation unit (252a) configured to calculate a body position of a body (201) of the agricultural work vehicle in the field;
a body direction calculation unit (252b) configured to calculate a direction in which the body (201) faces;
an automatic travel control unit (206A) configured to cause the body (201) to automatically travel based on a travel route serving as a target for automatic travel;
a work start point setting unit (293a) configured to set a work start point at which field work by automatic travel is started; and
a start guide management unit (257) configured to, in response to the body (201) facing a specified direction at a specified position, permit the body (201) to automatically travel along a work start point guiding route that is a travel route for the body (201) to automatically travel to the work start point.

2. The agricultural work vehicle as claimed in claim 1,
wherein the field is divided into a peripheral region extending along a boundary of the field and an inward region located inward of the peripheral region,
the automatic travel work is performed in the inward region by repeatedly traveling straight forward in the inward region and turning in the peripheral region,
the automatic travel work is performed in the peripheral region by traveling in a loop along the boundary in the peripheral region, and
the work start point guiding route is set in the peripheral region.

3. The agricultural work vehicle as claimed in claim 2,
wherein in response to the direction of the body, which is facing the work start point, matching a direction of the work start point guiding route bound for the work start point, the start guide management unit (257) permits the body (201) to automatically travel along the work start point guiding route to the work start point, regardless of the distance between the body (201) and the work start point.

4. The agricultural work vehicle as claimed in claim 2 or 3,
wherein in response to a front portion or a rear portion of the body (201) reaching the boundary, and furthermore the distance between the body (201) and the work start point being a predetermined distance or more, the start guide management unit (257) permits the body (201) to automatically travel along the work start point guiding route to the work start point.

5. The agricultural work vehicle as claimed in any one of claims 1 to 4,
wherein in response to the body (201) facing the specified direction at the specified position, a notification is given to indicate satisfaction of a condition for automatic travel along the work start point guiding route to the work start point.

6. The agricultural work vehicle as claimed in any one of claims 1 to 5,
wherein the specified position is a position in the field in which work is to be performed,
the specified direction is a direction in which the work start point guiding route extends, and
in response to the body (201) being on the work start point guiding route, a notification is given to indicate satisfaction of a condition for automatic travel to the work start point.