Field work vehicle

Abstract

To provide a field working vehicle capable of properly recognizing the arrival at a levee side area where the direction change of a traveling machine body is performed and performing proper direction change traveling.SOLUTION: The working vehicle is equipped with a traveling machine body traveling in a field while changing the direction in a levee side area, a field working device for performing work to the field, a positioning unit for outputting positioning data showing the position of the own vehicle, and a levee side detection module for detecting the levee side based on at least one of the behavior of the working device and the behavior of the traveling machine body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a field work vehicle that includes a running body that runs within a field while changing direction in the ridge area, a field work device that performs work on the field, and a positioning unit that outputs positioning data indicating the vehicle's position. [Background technology]

[0002] Patent Document 1 discloses a rice transplanter, a field work vehicle that automatically travels along a target route using position information measured by a GPS device. This rice transplanter performs seedling planting work while autonomously traveling along a linear target route, and when the driver confirms that the vehicle has reached the ridge area, also known as the headland, the driver operates the turning control to change direction of the vehicle in the desired direction, and the vehicle automatically turns in the ridge area to change direction. Once the change of direction is complete, the vehicle resumes planting work while autonomously traveling along the linear target route again. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-092818 Summary of the Invention [Problem to be solved by the invention]

[0004] When precision is required for aligning adjacent work areas (travel trajectories), such as in rice transplanters, advanced vehicle position detection technology and automatic steering control technology are required to automatically perform accurate alignment when turning during autonomous driving on headland. However, when such turning is performed using automatic steering or manual steering, it is important to accurately recognize the timing of starting the turn, that is, when the rice transplanter has reached the ridge area, and to accurately align the starting point for the next work drive after the turn, but these are difficult driving operations for unskilled drivers. In view of this situation, there is a need for a field work vehicle that can at least properly recognize when it has reached a ridge area (headland) where the traveling body changes direction, and can properly change direction while traveling. [Means for solving the problem]

[0005] The field work vehicle according to the present invention comprises a running body that runs within a field while changing direction in the ridge area, a field work device that performs work on the field, a positioning unit that outputs positioning data indicating the vehicle's position, and a ridge detection module that detects the ridge based on at least one of the behavior of the field work device and the behavior of the running body. In addition, the field work vehicle according to the present invention comprises a running body that runs within the field while changing direction in the ridge area, a field work device that performs work on the field, a positioning unit that outputs positioning data indicating the vehicle's position, an automatic steering section that automatically steers the running body, and a ridge detection module that detects at least one of whether the running body has approached or reached the ridge area based on the vehicle's position or the position of the field work device, and the ridge area is set based on the behavior of the field work device. In addition, the field work vehicle according to the present invention comprises a running body that runs within the field while changing direction in the ridge area, a field work device that performs work on the field, a positioning unit that outputs positioning data indicating the vehicle's position, a manual steering section that steers the running body based on human operation, an automatic steering section that automatically steers the running body, and a ridge detection module that detects that the running body has reached the ridge area based on the vehicle's position.

[0006] With this configuration, positioning data indicating the vehicle's position can be obtained from a positioning unit using a GNSS (Global Navigation Satellite System) or GPS (Global Positioning System), so as long as the location of the ridge area is set in advance, the ridge detection module can detect when the vehicle has reached the ridge area and communicate this information to the driver and the automatic steering control system. As a result, the vehicle's arrival at the ridge area, which previously required visual confirmation by the driver, can now be detected stably and accurately, reducing the burden on the driver.

[0007] One method for presetting the location of the ridge area is to install map data of the field, including the ridge area, and set the ridge area in the map data. By matching a field map based on this map data with the vehicle's own position obtained from the positioning unit, the position of the traveling field work vehicle within the field can be calculated in real time. This makes it possible to notify the automatic steering control system and the driver of the time when the traveling vehicle will reach the ridge area. For this reason, in one preferred embodiment of the present invention, a field map storage unit that stores map data of the field is provided, and the ridge detection module detects that the traveling vehicle has reached the ridge area by map matching the vehicle's own position with the map data.

[0008] In actual field work by a field work vehicle, the vehicle's behavior differs when traveling in non-ridge areas (work areas: generally areas other than the headland of the field) where work is carried out and when traveling in ridge areas where direction changes are required. This vehicle behavior includes the behavior of the traveling machine body and the behavior of the field work implement. In particular, by detecting the vehicle behavior that occurs when entering a ridge area from a non-ridge area and the vehicle behavior that occurs when entering a ridge area from a ridge area, and combining this with the vehicle's position at the time of detection, the boundary point between the ridge area and the non-ridge area can be obtained. In a typical field, the distance between adjacent boundary points is approximately equal to the distance between the travel trajectories during round-trip work travel, i.e., the work width, so it is also possible to estimate the next boundary point from the first boundary point obtained. For this reason, in one preferred embodiment of the present invention, a vehicle behavior recording unit is provided that records the behavior of the traveling machine body or the field work implement, or both, as vehicle behavior in relation to the position of the traveling machine body, and the ridge detection module detects that the traveling machine body has reached the ridge area based on the vehicle behavior.

[0009] Vehicle behaviors that occur when entering a ridge area from a non-ridge area, vehicle behaviors that occur when entering a ridge area from a ridge area to a non-ridge area, and vehicle behaviors that occur when entering a ridge area from a ridge area to a non-ridge area vary depending on the type of field work vehicle and the work content. Common vehicle behaviors in planting and sowing work using a rice transplanter, tilling work using a tractor, and harvesting work using a combine include the start and stop of work by the field work implement, the transition of the field work implement to a work position and a non-work position, and the start and stop of turning the traveling body. Therefore, in one preferred embodiment of the present invention, the vehicle behavior recording unit records the start and stop of work by the field work implement as the vehicle behavior. In another embodiment, the vehicle behavior recording unit records the transition of the field work implement to a work position and a non-work position as the vehicle behavior. In yet another embodiment, the vehicle behavior recording unit records the start and stop of turning travel of the traveling machine body as the vehicle behavior. Of course, these embodiments may be applied in any combination.

[0010] Also, the boundary point between the non-ridge area and the ridge area may be determined manually. For this reason, one embodiment of the present invention includes a driving mode switching device that is manually operated when transitioning between driving in the ridge area (ridge driving mode) and driving outside the ridge area (non-ridge driving mode), and the vehicle behavior recording unit records the operation of the driving mode switching device as the vehicle behavior.

[0011] As described above, once the boundary between the non-ridge area and the ridge area is determined based on the vehicle behavior, it is possible to estimate the boundary between the non-ridge area and the ridge area thereafter. Therefore, in one preferred embodiment of the present invention, the ridge detection module has a ridge estimation unit that estimates the timing of the next arrival of the traveling vehicle into the ridge area based on the vehicle behavior on the previous adjacent work travel route. This makes it possible to calculate the state of approach to the ridge area while traveling in the non-ridge area, and to perform appropriate and necessary control before or after reaching the ridge area.

[0012] For example, if an approach warning command is output to warn of the approach to the ridge area before the arrival time estimated by the ridge estimation unit, the driver can make any necessary operations or checks in the ridge area with ample time to do so. Furthermore, to avoid inconveniences associated with the traveling vehicle's unexpected approach to the ridge area, an embodiment can be adopted in which a deceleration command to decelerate the traveling vehicle is output before the arrival time estimated by the ridge estimation unit. Furthermore, an embodiment can be adopted in which a vehicle stop command to stop the traveling vehicle is output when the vehicle has traveled a predetermined distance from the arrival time estimated by the ridge estimation unit, or an embodiment can be adopted in which a vehicle stop command to stop the traveling vehicle is output in response to the arrival time estimated by the ridge estimation unit.

[0013] Completely different steering is performed when traveling in non-ridge areas and when traveling in ridge areas where direction changes are required. Therefore, whether these two different types of driving are performed by automatic steering or manual steering depends on the type of field work vehicle, the type of field work, the driver's skill level, and other factors. For this reason, one preferred embodiment of the present invention is provided with a steering mode management unit that manages the manual steering mode in which manual steering is performed by the manual steering unit and the automatic steering mode in which automatic steering is performed by the automatic steering unit. With this configuration, if an appropriate algorithm is built in beforehand, it is possible to appropriately assign automatic steering and manual steering depending on the driving situation and surrounding conditions.

[0014] For example, if it is technically burdensome to automatically steer when turning, the steering mode management unit can be configured to select manual steering mode in the fringe area and automatic steering mode outside the fringe area.

[0015] In addition, when automatic steering and manual steering are to be applied flexibly, it is preferable to adopt an embodiment in which a steering mode switching device is provided for manually selecting between the automatic steering mode and the manual steering mode.

[0016] Positioning units that use radio waves from satellites, such as GNSS and GPS, can become inoperable due to poor reception or other reasons, resulting in the inconvenience of being unable to obtain positioning data. For this reason, a preferred embodiment of the present invention includes a travel distance calculation unit that calculates the travel distance based on the number of wheel rotations. When the positioning unit becomes inoperable, the ridge detection module detects that the traveling vehicle has reached the ridge area based on the travel distance calculated by the travel distance calculation unit. This allows the traveling vehicle to detect that it has reached the ridge area even if the positioning unit becomes temporarily inoperable. In this case, if the travel distance calculation unit detects that the traveling vehicle has reached the ridge area due to the inoperability of the positioning unit, the traveling vehicle may be stopped at that point.

[0017] In particular, when traveling under automatic steering, it is difficult for the automatic steering control system to keep track of various vehicle conditions while traveling. One of the important vehicle conditions when traveling in a field is the attitude of the traveling vehicle body. The attitude of the traveling vehicle body is essentially determined by the inclination of the traveling vehicle body relative to the ground. In particular, pitching angles and rolling angles greater than a predetermined value have an adverse effect on traveling. For this reason, in one preferred embodiment of the present invention, an attitude determination unit is provided that determines the attitude of the traveling vehicle body, and if the attitude deviates from a predetermined condition, a braking command (including a stop command or a deceleration command) is output to slow down or stop the traveling vehicle body. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a schematic diagram illustrating the basic principle of vehicle control employed in a field work vehicle according to the present invention; [Figure 2] 1 is a schematic diagram illustrating the basic principle of vehicle control employed in a field work vehicle according to the present invention; [Figure 3] 1 is a side view of a rice transplanter that is one embodiment of a field work vehicle according to the present invention. [Figure 4] 1 is a plan view of a rice transplanter that is one embodiment of a field work vehicle according to the present invention. [Figure 5] FIG. 1 is a schematic diagram showing the steering system of a rice transplanter. [Figure 6] FIG. 2 is a functional block diagram showing functions related to travel control of the rice transplanter. [Figure 7] FIG. 2 is an explanatory diagram showing an example of a recorded vehicle behavior. DETAILED DESCRIPTION OF THE INVENTION

[0019] Before describing specific embodiments of the field work vehicle according to the present invention, the basic principles of vehicle control employed in the field work vehicle will be described with reference to FIG. In Figure 1, the field work vehicles are assumed to be a rice transplanter, a seed drill, a tractor, and a combine harvester. As the field work implements, the rice transplanter is equipped with a planting device, the seed drill is equipped with a sowing device, the tractor is equipped with a tilling device, and the combine harvester is equipped with a reaping device. These field work implements are connected to their respective traveling bodies so that they can be raised and lowered between a working position and a non-working position.

[0020] This field work vehicle (hereafter simply referred to as the vehicle) travels in a field bounded by parallel upper and lower ridges in Figure 1, repeatedly traveling back and forth in a straight line with 180-degree turns (U-turns) in between. An upper ridge edge area is set near the upper ridge, and a lower ridge edge area is set near the lower ridge. The vehicle turns in the ridge edge areas and travels in a straight line in the rest of the field.

[0021] The vehicle is equipped with a positioning unit that outputs positioning data indicating its own position. Furthermore, the vehicle is equipped with not only a manual steering unit that manually steers the traveling machine body, but also an automatic steering unit that automatically steers the traveling machine body. The positioning data output from the positioning unit is based on the antenna position, but in this case, the vehicle position is corrected to an appropriate position of the vehicle, such as the ground action point of a field work implement, rather than the antenna position.

[0022] An example of field travel in this field is shown below. First, the vehicle climbs over the lower ridge and enters the field, and at point A1, the driver operates the field work implement to lower it to a work position, commencing linear work travel (outbound). This descent of the field work implement is recorded as vehicle behavior indicating the start of work, along with positioning data indicating the position of point A1. After linear work travel, the vehicle reaches a direction change area at point B1, and the driver operates the field work implement to raise it to a non-work position, transitioning to a 180-degree direction change. This raising of the field work implement is recorded as vehicle behavior indicating the stop of work, along with positioning data indicating the position of point B1.

[0023] Once the vehicle has completed the turnaround in the ridge-edge area, it lowers the field work implement again to the work position at point A2 and starts the linear work travel (returning). This descent of the field work implement is also recorded as vehicle behavior indicating the start of work, along with positioning data indicating the position of point A2. The position of point A2 can be estimated from the position of point B1, taking into account the interval between the round-trip work travel equivalent to the work width (planting width or tilling width). Therefore, if the vehicle approaches the estimated point A2 while turning in the ridge-edge area, the driver can be notified of this and prompted to lower the field work implement to the work position. It is also possible to automatically lower the field work implement to the work position when the vehicle reaches the estimated point A2. The position where the vehicle again starts the linear work travel (returning) is set as the final point A2.

[0024] Point B2, which is the end point of this linear work run (return trip), i.e., the point where the vehicle will again reach the ridge area, can also be estimated from the position of point A1. Therefore, as the vehicle approaches point B2, it is possible to notify the driver that the field work implement should be raised to a non-working position before reaching the ridge area and preparations for turning can be made. It is also possible to automatically raise the field work implement to a non-working position when the vehicle reaches the estimated point B2. Once the vehicle reaches the ridge area, it will automatically or manually transition to turning within the ridge area. Once the turning trip is complete, the linear work run (return trip) will begin again from point A3.

[0025] In this way, work driving and direction-changing driving are repeated, passing through points B3, A4, B5, A6, etc. In this case, if point A1 is set, points B2, A3, etc. can be estimated from point A1, taking into account the interval between round-trip work driving. However, when estimating point A3, it can be estimated from point A1, but since point B2 is detected as the position where the vehicle actually transitioned from work driving to direction-changing driving, it is also possible to estimate point A3 from point B2. In particular, if the actual ridge area does not extend in a straight line but extends diagonally or in stages, the boundary point of such a ridge area can be correctly detected by estimating from a point newly set along the way.

[0026] For example, as shown in Figure 2, if the ridge area has a step, it is necessary to extend the straight-line work travel beyond the estimated point B4. If the straight-line work travel is being performed using automatic steering, the automatic steering is disengaged and the straight-line work travel is continued using manual steering until a position suitable for turning (newly set point B4) is reached. Once point B4 is newly set, the next point A5 is estimated from point B4.

[0027] The points A1, A2, ..., which are the start points of the work travel, can be automatically set based on a specific vehicle behavior. Suitable examples of such specific vehicle behavior include a work start command to the field work implement, detection of a change in the position of the field work implement to a work position, and detection of the engagement of a power transmission clutch for the field work implement. Furthermore, the state of an operating tool operated by the driver may be used as the specific vehicle behavior. Similarly, the points B1, B2, ..., which are the end points of the work travel (start points of turning travel), can also be automatically set based on a specific vehicle behavior. Suitable examples of such specific vehicle behavior include a work stop command to the field work implement, detection of a shift of the field work implement to a non-work position, and detection of the engagement of a power transmission clutch for the field work implement. Furthermore, the state of an operating tool operated by the driver may be used as the specific vehicle behavior.

[0028] If the initial work driving path defined by points A1 and B1 is taken as the reference work driving path, the target work driving path for subsequent automatic steering can be calculated based on this reference work driving path. Because work driving is generally straight-line driving and requires easier steering than turning driving, it is advantageous from a control perspective to perform work driving with automatic steering and turning driving with manual steering. If the field shape is a simple rectangle, once points A1 and B1 are set, the timing of the transition between subsequent work driving and turning driving, i.e., the timing of reaching the ridge area and the timing of leaving the ridge area, can be estimated from points A1 and B1.

[0029] If the vehicle enters the ridge area from a straight-line work drive (returning route) but does not change direction for some reason, the vehicle may end up on the ridge. To avoid this, it is important to estimate and record points B2, B3, B4, etc., which are the end points of the straight-line work drive (returning route). The positioning unit can calculate the vehicle's position, which can then be constantly compared with the end point of the work drive (returning route) (the point where the vehicle enters the ridge area). This makes it possible to slow down the vehicle, issue a warning, or stop the vehicle before and after it enters the ridge area.

[0030] In the example described above, points A1 and B1 were set during the first work drive, and points A2, A3, B2, B3, etc. between the subsequent work drive and the turn drive (the points where the vehicle reaches the ridge area and leaves the ridge area) were estimated from points A1 and B1. If the vehicle is equipped with a field map storage unit that stores map data of the field, map matching can be performed using the vehicle's position and the map data to detect when the vehicle has reached the ridge area or left the ridge area, making it unnecessary to set points A1 and B1 and to estimate other points from points A1 and B1.

[0031] Next, one specific embodiment of a field work vehicle according to the present invention will be described with reference to the drawings. Fig. 3 is a side view of a riding rice transplanter, which is an example of a field work vehicle, and Fig. 4 is a plan view. This rice transplanter is equipped with a traveling body C and a field work device that performs work on the field. The field work device here is a seedling planting device W that is capable of planting seedlings in the field. Note that arrow F shown in Fig. 4 indicates the "front" of the traveling body C, arrow B indicates the "rear" of the traveling body C, arrow L indicates the "left" of the traveling body C, and arrow R indicates the "right" of the traveling body C.

[0032] 3, the traveling device is provided with a pair of left and right front wheels 10 and a pair of left and right rear wheels 11. The traveling machine body C is provided with a steering unit U that can steer the left and right front wheels 10 of the traveling device.

[0033] As shown in Figures 3 and 4, an openable hood 12 is provided at the front of the traveling vehicle body C. An engine 13 is provided inside the hood 12. The traveling vehicle body C is provided with a frame-shaped vehicle body frame 15 that extends along the front-to-rear direction. A support column frame 16 is erected at the front of the vehicle body frame 15.

[0034] As shown in Figure 3, the seedling planting device W is connected to the rear end of the traveling body C so that it can be raised and lowered via a link mechanism 21 that is raised and lowered by the extension and contraction of a lifting cylinder 20 composed of a hydraulic cylinder. The seedling planting device W is equipped with four transmission cases 22, rotating cases 23 rotatably supported on the left and right rear sides of each transmission case 22, a pair of rotary planting arms 24 provided at both ends of each rotating case 23, multiple floats 25 for leveling the field surface, and a seedling loading platform 26 on which mat-like seedlings for planting are placed. In other words, the seedling planting device W is configured as an eight-row planting type.

[0035] The left and right sides of the hood 12 of the traveling body C are provided with a plurality of (e.g., four) regular spare seedling trays 28 on which spare seedlings to be replenished to the seedling planting device W can be placed, and one rail-type spare seedling tray 29 on which spare seedlings to be replenished to the seedling planting device W can be placed. The left and right sides of the hood 12 of the traveling body C are also provided with a pair of left and right spare seedling frames 30 that support each regular spare seedling tray 28 and the rail-type spare seedling tray 29, and a connecting frame 31 that connects the upper parts of the left and right spare seedling frames 30. The connecting frame 31 is U-shaped in front view. The left and right ends of the connecting frame 31 are connected to the upper parts of the left and right spare seedling frames 30 via connecting brackets 32, respectively.

[0036] A driving section 40 where various driving operations are performed is provided in the center of the traveling vehicle body C. The driving section 40 is provided with a driver's seat 41 where the driver can sit, a control tower 42, a steering handle 43 consisting of a steering wheel for manually steering the front wheels 10, a main speed change lever 44 that can switch between forward and reverse travel and change the traveling speed, an operating lever 45, etc. The driver's seat 41 is provided in the center of the traveling vehicle body C. The steering handle 43 and main speed change lever 44 are provided on the control tower 42 so that they can be freely operated. A boarding step 46 is provided at the foot of the driving section 40.

[0037] An operating lever 45 is provided on the right side below the steering handle 43. When the operating lever 45 is operated to the up position, a planting clutch (not shown), which is a type of work clutch, is disengaged and the seedling planting device W rises. When the operating lever 45 is operated to the down position, the planting clutch (not shown) is disengaged and the seedling planting device W descends. When the central float 25 touches the paddy field surface, the seedling planting device W touches the paddy field surface and comes to a stop.

[0038] As shown in FIG. 5, the steering unit U includes the above-mentioned steering handle 43, a steering operation shaft 54 ​​operatively connected to the steering handle 43, a pitman arm 55 that swings in conjunction with the rotation of the steering operation shaft 54, left and right linking mechanisms 56 operatively connected to the pitman arm 55, a steering motor 58, and a gear mechanism 57 operatively connecting the steering motor 58 to the steering operation shaft 54.

[0039] The steering unit U can operate in an automatic steering mode and a manual steering mode. In the manual steering mode, an auxiliary force corresponding to the operation of the steering wheel 43 by the steering motor 58 is applied to the operating force applied by the driver to operate the steering wheel 43, thereby rotating the steering shaft 54 ​​and changing the steering angle of the front wheels 10. On the other hand, in the automatic steering mode, the steering motor 58 is automatically controlled, and the driving force of the steering motor 58 is used to rotate the steering shaft 54 ​​and change the steering angle of the front wheels 10. In this embodiment, the steering wheel 43 and the steering motor 58 function as components of a manual steering section that manually steers the traveling machine body C. In addition, the automatic steering control function that automatically steers the traveling machine body C is built into a control device 8 (see FIG. 6 ), which will be described later, and the steering motor 58 is driven based on a control command from the control device 8. In addition, when the operational displacement of the steering wheel 43 is not directly transmitted to the steering operation shaft 54 ​​but is detected by a sensor and the steering motor 58 is driven based on the detected value, that is, when a so-called by-wire system is adopted, a control function for manual steering is also built into the control device 8.

[0040] The traveling machine body C is equipped with a positioning unit 61, and the traveling machine body C's own position is determined from the positioning data from the positioning unit 61. The positioning unit 61 includes a satellite navigation module configured as a GNSS module, and an inertial navigation module configured as a module incorporating a gyro acceleration sensor and a magnetic direction sensor. A satellite antenna for receiving GPS signals and GNSS signals is connected to the satellite navigation module. At least this satellite antenna is attached to a location with good radio wave reception sensitivity, which in this embodiment is the connecting frame 31. The satellite navigation module and the inertial navigation module may be provided in different locations.

[0041] FIG. 6 shows the control device 8 equipped on this rice transplanter. Of the functional units configured in the control device 8, FIG. 6 mainly shows the functional units related to steering. This control device 8 employs the basic principles of automatic steering and manual steering explained using FIG. 1 and FIG. 2. The control device 8 is connected to a positioning unit 61, a vehicle state detection sensor group 9, a contact detector 90, a driving mode switching operation device 65, and a steering mode switching operation device 66 via an input signal processing unit 8a. The control device 8 is also connected to the notification device 7, a vehicle driving equipment group 71, and a work equipment group 72 via an output signal processing unit 8b. The driving mode switching operation device 65 and the steering mode switching operation device 66 are configured as switches or buttons.

[0042] The vehicle state detection sensor group 9 consists of various sensors and switches provided to detect the movement and posture of the traveling machine body C and the movement and posture of the seedling planting device W as a field work device. The contact detector 90 is well known and is not shown in Figures 3 and 4, but it has a structure for detecting contact between the rice transplanter and an obstacle. When the contact detector 90 detects contact between the rice transplanter and an obstacle, the rice transplanter makes an emergency stop. The steering mode switching device 66 is a switch that selects either an automatic steering mode in which the rice transplanter travels with automatic steering or a manual steering mode in which the rice transplanter travels with manual steering. For example, operating the steering mode switching device 66 while traveling with automatic steering switches the rice transplanter to traveling with manual steering, and operating the steering mode switching device 66 while traveling with manual steering switches the rice transplanter to traveling with automatic steering.

[0043] The driving mode switching operation device 65 is a teaching switch for instructing the control device 8 about the boundary between the ridge area and the non-ridge area, and in this embodiment, the driving mode switching operation device 65 has a button A and a button B. The driver presses button A when the vehicle is to transition from turning driving to work driving, and presses button B when the vehicle is to transition from work driving to turning driving.

[0044] The notification device 7 includes a lamp and a buzzer, and outputs various information to be notified to the driver visually or audibly, such as approaching a ridge area or deviation from a target driving route during automatic steering, based on commands from the control device 8. Furthermore, if the notification device 7 includes a flat panel display or the like, it is also possible to provide text information.

[0045] The vehicle travel equipment group 71 includes various operating and control equipment for travel that is mounted on the travel body C, such as operating equipment such as the steering motor 58 that constitutes the steering unit U, control equipment that adjusts the engine speed, transmission operating equipment such as a clutch and shifter, and brake operating equipment. In this embodiment, the work travel equipment group includes operating equipment such as the lifting cylinder 20 that raises and lowers the seedling planting device W mounted as a field work device, and a planting clutch that functions as a work clutch for the seedling planting device W.

[0046] The control device 8 includes a furrow detection module 81, an automatic steering unit 82, a vehicle behavior recording unit 83, a steering mode management unit 84, a driving path calculation unit 85, a driving distance calculation unit 86, an attitude determination unit 87, and the like, which are essentially constructed using computer programs.

[0047] The ridge detection module 81 detects whether the traveling vehicle C has reached the ridge based on the travel path reference points set in the first work travel—point A1, where travel in the ridge area transitions to work travel, point B1, where work travel transitions to turning travel in the ridge area, and the vehicle position obtained from the positioning data of the positioning unit 61. As explained using FIGS. 1 and 2, point A1 is detected by the seedling planting device (working device) W descending to its lowered position (working position), and point B1 is detected by the seedling planting device W ascending to its raised position (non-working position), and each is recorded as a vehicle behavior in the vehicle behavior recording unit 83. The travel path (generally a straight line) between points A1 and B1 is the reference work travel path. Whether the vehicle is automatically steered or manually steered, the next work travel path can be obtained by sequentially translating this reference work travel path by the round-trip work travel interval. That is, points B2, A3, B4, A5, etc. corresponding to point A1, and points A2, B3, B4, A4, B5, etc. corresponding to point B1 are estimated. This estimation algorithm is implemented in the ridge estimation unit 810. Because the method for estimating the points indicating the boundaries of the ridge area differs depending on the shape of the field, it is preferable to have a configuration that allows an appropriate estimation algorithm to be selected for each field shape. By comparing each of these points with the vehicle's position, the distance until the traveling vehicle C reaches the ridge area during work is detected, and the control device 8 can output commands such as an approach alert when the traveling vehicle C approaches the ridge area by a predetermined distance, an arrival alert when the traveling vehicle C reaches the ridge area, decelerate the traveling vehicle C, or stop the traveling vehicle C.

[0048] The driving route calculation unit 85 calculates driving route data required for subsequent work driving using automatic steering from the above-mentioned standard work driving route. The automatic steering unit 82 calculates the deviation between the driving route data calculated by the driving route calculation unit 85 and the vehicle position, generates an automatic steering command, and outputs it to the steering unit U.

[0049] The steering mode management unit 84 manages the manual steering mode, in which the vehicle travels by manual steering, and the automatic steering mode, in which the vehicle travels by automatic steering. For example, it is possible to set the system so that the manual steering mode is selected in the ridge area, and the automatic steering mode is selected outside the ridge area (generally, when traveling for work in a straight line). It is also possible to forcibly select between the manual steering mode and the automatic steering mode by issuing a switching command from the steering mode switching operation device 66. Furthermore, it is also possible to set the system so that the automatic steering mode is forcibly switched to the manual steering mode by operating the steering wheel 43.

[0050] The vehicle behavior recording unit 83 records the conditions that occur in the vehicle, in particular vehicle behaviors relating to the start and end of work travel, based on various sensor detection signals and operation signals from various operation devices input via the input signal processing unit 8a, and control signals output via the output signal processing unit 8b to the vehicle travel equipment group 71 and the work device equipment group 72. At that time, each vehicle behavior is recorded together with the vehicle position obtained when the vehicle behavior occurred.

[0051] FIG. 7 shows an example of vehicle behavior recorded in chronological order by the vehicle behavior recording unit 83 during travel in a simplified farm field such as that shown in FIG. 1. In this example, the items recorded by the vehicle behavior recording unit 83 include a record number, behavior time, vehicle position, and behavior content. The behavior time is the time (timestamp) at which the vehicle behavior was detected. The vehicle position is the vehicle position at the time the vehicle behavior was detected. The behavior content identifies the detected vehicle behavior, and in this case, the operation content of the travel mode switching operating device 65 (A means operation of button A, and B means operation of button B), the positions of the seedling planting device W and float 25, the state of the planting clutch (work clutch), and the steering state (steering from straight ahead to turning, or steering from turning to straight ahead). In Figure 7, the vehicle position for each vehicle behavior is the same, but the timing of raising and lowering the seedling planting device W and the steering timing when turning are different, so the vehicle position varies.However, here, the recorded vehicle position is corrected to replace it with the reference position of a specific vehicle.

[0052] As can be seen from FIGS. 1 and 7, the vehicle behavior recording unit 83 records various states of the traveling machine body C and the seedling planting device W, which is a work device, particularly the start and end of work. As the first process of seedling planting work using this rice transplanter, the vehicle enters the ridge from the paddy field into the ridge-edge area, and record number "0001" is recorded when it leaves the ridge-edge area. The contents of record number "0001" are a record of point A1 in FIG. 1 and include the behavior time, vehicle position, and behavior details at that time. The behavior details include the traveling operation mode being "A," the seedling planting device position being "down," the float position being "grounded," and the clutch state being "on." In reality, the timing at which these behavior details are detected varies slightly, but here, they are assumed to be the same. In other words, when record number "0001" was recorded, the driver pressed button A on the traveling mode switching device 65, and the vehicle was set up for work traveling.

[0053] After this, the vehicle travels in a straight line, and when it reaches the edge of the field, record number "0002" is recorded. Record number "0002" is a record of point B1 in Figure 1, and includes the time of the behavior, the vehicle's position, and the behavior details at that time. The behavior details include the travel operation mode being "B," the seedling planting device position being "raised," the float position being "disengaged," the clutch state being "disengaged," and the steering being "straight to turning." In other words, when record number "0002" was recorded, the driver pressed button B on the travel mode switching device 65, and the vehicle was set to turn. By operating buttons A and B on the travel mode switching device 65 in this way, the positions of points A1 and B1 are recorded. The line connecting points A1 and B1 can be used as a reference travel route for estimating the travel route for subsequent work travel. Therefore, no operation of the travel mode switching device 65 is required except at points A1 and B1.

[0054] When the vehicle completes turning in the ridge area, exits the ridge area, and begins work driving, record number "0003" is recorded. The contents of record number "0003" are records of point A2 in FIG. 1 , and include the time of the behavior, the vehicle's position, and the behavior details at that time. Note that, if the field is a field like that of FIG. 1 , the position of point A2 is estimated from point B1 by the ridge estimation unit 810 using the round-trip work driving interval. Therefore, when the vehicle's position acquired from the positioning unit 61 approaches or coincides with the estimated point B1, the work driving can be automatically set. Alternatively, the vehicle can be notified that it is approaching point B1, prompting the driver to set up work driving. Similarly, the position of point B2 is also estimated from point A1. Therefore, when the vehicle's position acquired from the positioning unit 61 approaches or coincides with the estimated point B2, the turn-around driving can be automatically set. Alternatively, the driver can be notified that the vehicle is approaching point B2 and prompted to set up a turnaround.

[0055] As explained above, the timing of arrival at and departure from the ridge can be determined by changes in the position of the seedling planting device W or float 25, the operation of the work clutch, and changes in steering angle. Therefore, the driving mode switching device 65 is not required as a teaching device for recognizing the boundary of the ridge. The boundary of the ridge can be determined by one or a combination of the vehicle behaviors described above. For example, if the seedling planting device W's characteristic of descending to the field surface at the start of work and rising from the field surface at the end of work is utilized, the transition point of the vehicle from the ridge to the working area (non-ridge area) can be determined based on a status signal indicating the seedling planting device W's descent from a raised position to a lowered position. The transition point of the vehicle from the working area (non-ridge area) to the ridge can also be determined based on a status signal indicating the seedling planting device W's ascent from a lowered position to a raised position.

[0056] The control device 8 can be equipped with an algorithm that outputs various commands to execute various operations based on the determination result of the ridge detection module 81 regarding the vehicle's arrival at the ridge area. Some of these are listed below. (1) If the vehicle reaches a point where a recorded vehicle behavior is scheduled to be executed but the vehicle behavior is not executed, the vehicle is decelerated, the engine is stopped, or the like. (2) When driving in a field, the location and time at which each vehicle behavior to be recorded occurs can be limited to a specific range. Therefore, vehicle behavior outside the specific range is not recorded, thereby improving recording accuracy. (3) When the vehicle is detected to have entered the edge of a field, automatic steering is prohibited. (4) If the steering behavior of the vehicle in the ridge area, such as the steering angle and turning radius, differs from that of turning, recording to the vehicle behavior recording unit 83 is stopped. For example, if the turning radius is large, it is not considered turning, but rather driving that is not normal work driving, such as driving to leave the field. (5) When a specific vehicle behavior occurs, if a vehicle speed inappropriate for that vehicle behavior is detected, the vehicle is forcibly stopped.

[0057] The traveling distance calculation unit 86 calculates the traveling distance of the traveling vehicle C based on a detection signal from a sensor (one of the vehicle state detection sensors 9) that detects the rotation speed of the rear wheels 11 or the rotation speed of the transmission system to the rear wheels 11. At this time, the traveling distance can be calculated more accurately by taking into account the slip ratio estimated from the state of the field. In the case of the positioning unit 61, which calculates the vehicle's position based on radio signals from a satellite, if the reception sensitivity of the radio signals decreases for some reason, the positioning data cannot be output. The traveling distance calculation unit 86 is used to recover from this. For example, if the positioning data from the positioning unit 61 is not input, the ridge detection module 81 can detect that the traveling vehicle C has reached the ridge area based on the traveling distance calculated by the traveling distance calculation unit.

[0058] The attitude determination unit 87 compares the attitude of the traveling machine body C with a predetermined inclination threshold based on a detection signal from an inclination sensor (one of the vehicle state detection sensors 9) that detects the inclination angle (rolling angle and pitching angle) of the traveling machine body C. In this embodiment, when the attitude of the traveling machine body deviates from a predetermined condition, the attitude determination unit 87 issues a braking command to a braking device, which is one of the vehicle traveling device group 71, to slow down or stop the traveling machine body.

[0059] Specific control operations based on the determination results of the attitude determination unit 87 are listed below. (1) When the detected tilt angle exceeds the tilt threshold, an alarm is issued, the vehicle is decelerated, and the vehicle is stopped. (2) Prohibit automatic steering if the detected lean angle frequently exceeds the lean threshold. (3) If the detected inclination angle exceeds the inclination threshold for a certain period of time, the system issues a warning, decelerates, and stops the vehicle. This period of time is determined based on the vehicle speed and field depth. If the field depth exceeds a certain value, the system prohibits the vehicle from coming to a complete stop to prevent the vehicle from sinking. (4) The change in acceleration of the incline is calculated, and when the incline changes suddenly, automatic steering is prohibited even if the incline is below the incline threshold.

[0060] [Another embodiment] (1) In the above-described embodiment, points A1 and B1, which are the boundary points between the ridge area where turning is performed and the non-ridge area where work is performed, are determined by operating button A and button B of the driving mode switching device, and the subsequent points A2, A3, etc. and points B2, B3, etc. are estimated from point A1 and point B1 and confirmed based on vehicle behavior. To simplify control, points A2, A3, etc. and points B2, B3, etc. are estimated from point A1 and point B1 without using vehicle behavior, and if a position different from the estimated position is to be determined as the official position, button A or button B of the driving mode switching device may be operated again to confirm the point. (2) The functional units in the functional block diagram shown in Figure 6 are separated primarily for explanatory purposes. In reality, each functional unit in Figure 6 can be integrated with other functional units or separated into multiple functional units. The independent functional units are connected to each other via an in-vehicle LAN or the like. (3) In the case of a rice transplanter, in addition to the above, the vehicle behavior recorded in the vehicle behavior recording unit 83 may also include the posture of the marker. In addition, vehicle behavior occurring at the boundary between the ridge area and the non-ridge area is also included in the vehicle behavior to be recorded in the vehicle behavior recording unit 83. [Industrial Applicability]

[0061] In addition to the riding rice transplanter described above that is equipped with a seedling planting device as a working device, the present invention can also be applied to various other work vehicles, such as a riding direct seeding machine that is a planting-type paddy field work vehicle equipped with a sowing device as a working device, a tractor equipped with a plow or the like as a working device, or an agricultural work vehicle such as a combine harvester equipped with a harvesting section or the like as a working device, or a construction work vehicle equipped with a bucket or the like as a working device. [Explanation of symbols]

[0062] 7: Notification device 25: Float 26: Seedling tray 43: Steering wheel 44: Main shift lever 45: Control lever 61: Positioning unit 65: Driving mode switching device 66: Steering mode switching device 71: Vehicle running equipment group 72: Working equipment equipment group 8: Control device 8a: Input signal processing section 8b: Output signal processing section 81: Ridge detection module 810: Ridge edge estimation part 82: Automatic steering unit 83: Vehicle behavior recording unit 84: Steering mode management unit 85: Route calculation unit 86: Travel distance calculation unit 87: Posture determination section 9: Vehicle state detection sensors 90: Contact detector U: Steering unit W: Seedling planting device (field work device)

Claims

[Claim 1] A traveling machine that travels within the field while changing direction in the ridge area, a field work device that performs work on the field; a positioning unit that outputs positioning data indicating the vehicle's position; a ridge detection module that detects a ridge based on at least one of the behavior of the field work implement and the behavior of the traveling machine body.

Images