Autonomous Driving Control System

Abstract

To accurately perform automatic travel along a target travel route.SOLUTION: Provided is an automatic travel control system for a work vehicle that performs automatic travel along a target travel route, wherein the target travel route generated by a travel route calculation unit includes a plurality of route elements and a target azimuth TD that is an azimuth along the target travel route in each route element, and a travel control unit combines traveling target azimuth, which is a target azimuth TD in the route element corresponding to a position P of the work vehicle body and a destination target azimuth, which is the target azimuth TD corresponding to each of the destination route elements LA, which is one or more route elements that will be passed thereafter and performs automatic travel control such that a driving azimuth of the work vehicle in the route element becomes a combined target azimuth TDM.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to an automatic driving control system for controlling the automatic driving of a work vehicle that automatically drives along a target driving route. [Background technology]

[0002] As disclosed in Patent Document 1, a work vehicle such as a rice transplanter works while automatically traveling along a target travel route generated in a field. Here, the target travel route includes a curved section, and the work vehicle changes its traveling direction at the curved section. When the work vehicle reaches the curved section (start position of the travel direction change), automatic steering control is performed so that the work vehicle travels along the target travel route. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-108611 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, automatic steering control can be difficult at places with sharp bends, and the work vehicle may deviate from the target driving path and not be able to drive automatically properly.

[0005] An object of the present invention is to perform automatic driving along a target driving route with high accuracy. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, an automatic driving control system according to one embodiment of the present invention is an automatic driving control system for a work vehicle that automatically drives along a target driving route, and includes a vehicle position calculation unit that calculates the position and driving direction of the work vehicle's body, a driving route calculation unit that generates the target driving route, and a driving control unit that controls the work vehicle to drive along the target driving route based on the position of the vehicle and the driving direction, wherein the target driving route generated by the driving route calculation unit includes a plurality of route elements and a target orientation that is an orientation along the target driving route in each of the route elements, and the driving control unit generates a composite target orientation by combining a driving target orientation that is the target orientation in the route element corresponding to the position of the vehicle's body of the work vehicle and a destination target orientation that is the target orientation corresponding to each of one or more of the route elements that are scheduled to be passed through later, and performs automatic driving control so that the driving orientation of the work vehicle in the route element becomes the composite target orientation.

[0007] In automated driving along a target driving route, when the direction of travel is changed, there may be a delay in starting to change the direction of travel relative to the target driving route.

[0008] A composite target heading is generated by combining the target heading during travel and the target heading to the destination, and steering control is performed so that the travel direction is oriented toward the composite target heading. As a result, since the target heading to the destination is taken into consideration, delays in starting to change the direction of travel are suppressed, and automatic travel along the target travel route can be performed with high accuracy.

[0009] In addition, it is preferable that the composite target orientation is formed by combining each of the destination target orientations and the in-travel target orientations at a predetermined proportional ratio, and that the proportional ratio of each of the destination target orientations becomes higher as the current position of the aircraft approaches the destination route element.

[0010] With this configuration, the weighting of the destination target orientation is increased as the vehicle approaches the start point of the change in direction of travel, and a composite target orientation is generated. Therefore, as the vehicle approaches the start point of the change in direction of travel on the target travel route, the steering control gradually progresses, and the vehicle can travel automatically along the target travel route with high accuracy.

[0011] In addition, it is preferable that the composite target orientation is obtained by combining the destination target orientation and the in-travel target orientation in the next destination route element that is scheduled to be passed through, at a proportional ratio determined according to the distance between the destination route element and the position of the aircraft.

[0012] With this configuration, the target orientations before and after the point where the direction of travel is changed can be combined to generate a combined target orientation. This prevents the direction of travel from starting too early, and the steering control gradually progresses as the vehicle approaches the starting point of the direction of travel on the target travel route, making it possible to perform automatic travel along the target travel route with high accuracy.

[0013] It is also preferable that the distribution ratio varies depending on the azimuth difference between the destination target azimuth and the current traveling target azimuth, and that the distribution ratio of the destination target azimuth becomes higher as the azimuth difference becomes larger.

[0014] With this configuration, the weighting of the destination target direction can be increased as the angle of the change in direction becomes larger, and the direction of travel is changed while taking the destination target direction into sufficient consideration. As a result, automatic travel along the target travel route can be performed with high accuracy.

[0015] Further, the driving route calculation unit divides each of the route elements at a predetermined distance to set divided route elements, and generates a divided target orientation for each of the divided route elements, and the driving control unit At least before and after the change in direction The divided target azimuths in the divided route elements may be combined to generate the combined target azimuth.

[0016] When the route element is long, steering control may be started too early with respect to the travel direction change point. According to the above configuration, the composite target orientation is generated a predetermined distance before the travel direction change point, so that the composite target orientation is generated with high accuracy, and automatic travel along the target travel route can be performed with high accuracy.

[0017] The distance may be variable depending on a direction difference between the destination target direction and the current traveling target direction, and may be longer as the direction difference increases.

[0018] According to the above configuration, the larger the angle of the change in direction of travel, the earlier steering control can be started before the point at which the direction of travel is to be changed, making it easier to change the direction of travel to follow the destination route elements, and enabling automatic travel along the target travel route with high accuracy. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a left side view of the automatically-traveling rice transplanter. [Diagram 2] FIG. 2 is a diagram illustrating an example of a functional block configuration related to automated work driving. [Diagram 3] FIG. 1 is a schematic diagram illustrating the operation travel of the rice transplanter. [Figure 4] 11 is a diagram illustrating a change in the traveling direction during a circuit and generation of an outer circuit path. FIG. [Diagram 5] 11 is a diagram illustrating a change in the traveling direction during a circuit and generation of an outer circuit path. FIG. [Figure 6] FIG. 2 is a diagram illustrating the position of the aircraft. [Figure 7] FIG. 2 is a diagram illustrating automatic driving along a target driving route. [Figure 8] 11A and 11B are diagrams illustrating an example of generating a direction change route. [Figure 9] 11A and 11B are diagrams illustrating an example of generating a direction change route. [Figure 10] FIG. 13 is a diagram for explaining allocation rates. [Figure 11] FIG. 13 is a diagram for explaining a configuration example for generating a composite target azimuth in a divided route element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The following describes an example of a work vehicle of the present invention, which is a rice transplanter that plants seedlings in a field FL while automatically traveling.

[0021] For ease of understanding, in this embodiment, unless otherwise specified, "front" (the direction of arrow F shown in FIG. 1) means the front in the longitudinal direction (traveling direction) of the machine body, and "rear" (the direction of arrow B shown in FIG. 1) means the rear in the longitudinal direction (traveling direction) of the machine body. In addition, the left-right direction or lateral direction means the transverse direction of the machine body (machine body width direction) perpendicular to the longitudinal direction of the machine body, "left" means the direction toward the front of the paper in FIG. 1, and "right" means the direction toward the back of the paper in FIG. 1.

[0022] [Overall structure] As shown in Fig. 1, the rice transplanter is a riding type with a four-wheel drive body 1. The body 1 includes a parallel four-link type link mechanism 13 connected to the rear of the body 1 so as to be able to rise and fall and swing, a hydraulic lifting link 13a that drives the link mechanism 13 to swing, a seedling planting device 3 connected to the rear end region of the link mechanism 13 so as to be able to roll, and a fertilizer applicator 4 installed from the rear end region of the body 1 to the seedling planting device 3.

[0023] The machine body 1 is equipped with wheels 12 as a mechanism for traveling, an engine 2, and a hydraulic continuously variable transmission 9 as a main transmission. The continuously variable transmission 9 is, for example, an HST (Hydro-Static Transmission). The wheels 12 have left and right front wheels 12A that can be steered, and left and right rear wheels 12B that cannot be steered. Power output from the engine 2 is transmitted to the continuously variable transmission 9 via a traveling transmission mechanism, and is also transmitted from the continuously variable transmission 9 to the front wheels 12A, the rear wheels 12B, the working equipment 1C (seedling planting equipment 3, fertilizer application equipment 4, etc.), etc. The engine 2 and the continuously variable transmission 9 are mounted on the front of the machine body 1.

[0024] As an example, the seedling planting device 3 is configured for eight rows of planting. The seedling planting device 3 includes a seedling stand 21, eight rows of planting mechanisms 22, etc. The seedling planting device 3 can be changed to two-row, four-row, six-row, etc. planting by controlling the clutch for each row (not shown).

[0025] The seedling placement table 21 is a base on which eight rows of mat-shaped seedlings are placed. The seedling placement table 21 continuously moves back and forth (lateral feed) in the left and right direction at a constant stroke corresponding to the left and right width of the mat-shaped seedlings, and each time the seedling placement table 21 reaches the left and right stroke ends by a predetermined number of lateral feeds, each mat-shaped seedling on the seedling placement table 21 is vertically fed toward the lower end of the seedling placement table 21 at a predetermined pitch (vertical feed amount). The eight planting mechanisms 22 are rotary type and are arranged in the left and right direction at a constant interval corresponding to the spacing between the planting rows. Each planting mechanism 22 receives power from the engine 2 when a planting clutch (not shown) is shifted to a transmission state, and cuts out one seedling (a seedling to be planted) from the lower end of each mat-shaped seedling placed on the seedling placement table 21 and plants it in the muddy soil after the land is leveled at a predetermined spacing between the seedlings. As a result, when the seedling planting device 3 is in an operating state, the seedlings can be taken out of the mat-shaped seedlings placed on the seedling placement table 21 and planted in the muddy soil of the paddy field.

[0026] The fertilizer application device 4 has a hopper 25 (storage section) that stores granular or powdered fertilizer, a feed mechanism 26 that feeds the fertilizer from the hopper 25, and a fertilizer application hose 28 that transports the fertilizer fed by the feed mechanism 26 and discharges the fertilizer into the field FL (see FIG. 2). The fertilizer stored in the hopper 25 is fed in predetermined amounts by the feed mechanism 26 and sent to the fertilizer application hose 28, transported inside the fertilizer application hose 28 by the conveying wind of a blower 27, and discharged from a furrow former 29 into the field FL. In this way, the fertilizer application device 4 supplies fertilizer to the field FL.

[0027] As shown in FIG. 1, the machine body 1 is provided with a driving section 14 in the rear side area. The driving section 14 is provided with a steering handle 10 for steering the front wheels, a main speed change lever 7A for adjusting the vehicle speed by changing the speed of the continuously variable transmission 9, a sub-speed change lever 7B for changing the speed of the sub-speed change lever, a work operation lever 11 for enabling the raising and lowering operation of the seedling planting device 3 and switching of the operating state, a detachable information terminal 5 having a touch panel for displaying (notifying) various information and notifying (outputting) it to the operator and for receiving input of various information, and a driver's seat 16 for the operator (driver / worker). The sub-speed change lever 7B is used to switch the traveling vehicle speed between a working speed during work and a moving speed during movement. For example, movement between fields is performed at the moving speed, and planting work, etc. is performed at the working speed. Furthermore, in front of the driving section 14, a spare seedling storage device 17A for storing spare seedlings is supported on a spare seedling support frame 17.

[0028] Furthermore, the aircraft 1 is equipped with a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position and orientation of the aircraft 1. The positioning unit 8 includes a satellite positioning module 8A that receives radio waves from satellites of the Global Navigation Satellite System (GNSS), and an inertial measurement module 8B that detects the inclination and acceleration of the three axes of the aircraft 1. The positioning unit 8 is supported on the upper part of the spare seedling support frame 17. Based on the positioning data acquired by the positioning unit 8, the position P of the aircraft is continuously calculated and stored.

[0029] [Autonomous Driving] The automatic operation travel in which the rice transplanter performs seedling planting work in the farm field FL by automatic travel will be described with reference to FIG. 1 and with reference to FIGS. 2 to 7. FIG.

[0030] First, the functional configuration for automatic operation travel of the rice transplanter will be described with reference to FIG. 2.

[0031] The rice transplanter includes a control unit 30 that controls automatic work travel in the machine body 1. The control unit 30 is capable of data communication with the positioning unit 8, the steering handle 10, the wheels 12, the work device 1C, etc. The control unit 30 includes a machine body position calculation unit 33, a travel path calculation unit 35, a travel control unit 37, a work control unit 38, and a memory unit 40.

[0032] The aircraft position calculation section 33 acquires positioning data from the positioning unit 8, and calculates the aircraft position P and the traveling direction of the aircraft 1 at the aircraft position P intermittently at predetermined time intervals based on the positioning data.

[0033] The travel path calculation unit 35 generates a field map based on the position P of the machine calculated during peripheral travel along the outer periphery (outer edge) of the field FL. Furthermore, the travel path calculation unit 35 generates a target travel path TL for automatic travel. The target travel path TL includes multiple route elements, and includes a target orientation TD, which is a direction along the route element, for each route element.

[0034] The driving control unit 37 performs steering control and drive control in automatic driving and manual driving. In steering control, the driving control unit 37 controls the front wheels 12A so that the vehicle travels along the target driving route TL in automatic driving, and controls the front wheels 12A in response to the driver's operation of the steering wheel 10 in manual driving. In automatic driving, the driving control unit 37 controls the driving direction of the vehicle 1 so that the vehicle travels in agreement with the target direction TD corresponding to the route element during driving.

[0035] The work control unit 38 controls the operation of the working device 1C according to the operation of the driver or a preset program.

[0036] The storage unit 40 stores various information such as the generated target travel path TL, a program for automatically controlling the working device 1C, and the position P of the device.

[0037] Next, a configuration for generating a target driving route TL and performing automatic driving (automatic steering) along the target driving route TL will be described with reference to Figs. 2 to 7.

[0038] The rice transplanter in this embodiment can selectively perform manual travel and automatic travel. Manual travel (manual work travel) and automatic travel (automatic work travel) are selected by switching an automatic / manual changeover switch (not shown) arranged in the driving unit 14.

[0039] When the rice transplanter performs seedling planting work, first, the driver manually drives the rice transplanter along the periphery (outer edge) of the field FL (periphery driving). As shown in Fig. 3, the driving path calculation unit 35 generates the peripheral shape (field map) of the field FL by this peripheral driving, and divides the field FL into an outer peripheral area OA and an inner area IA. At this time, one side or specified multiple sides of the outer periphery of the field FL are set as a supply side SL for supplying agricultural materials such as mat-shaped seedlings, fertilizer, chemicals, and fuel to the rice transplanter.

[0040] As shown in Figs. 2 to 5, when the field map is generated, the travel path calculation unit 35 sets a target travel path TL along which the rice transplanter will travel for work. The target travel path TL includes a plurality of path elements set on the target travel path TL, and a target orientation TD (see Fig. 7) which is a direction along the target travel path TL in each path element. The path elements are formed from straight lines (approximate straight lines) connecting at least two nodes LN. The nodes LN correspond to at least a part of the position P of the machine that is intermittently calculated based on the positioning data acquired by the positioning unit 8.

[0041] In the internal area IA, an internal round-trip path IPL and a turning path are generated as a target travel path TL. The internal round-trip path IPL is a path element that is approximately parallel to one side of the field FL, and the turning path is a path that connects the two internal round-trip paths IPL. The internal round-trip path IPL is a travel path that performs work travel throughout the entire internal area IA. Automatic work travel is performed along the internal round-trip path IPL. The turning travel of the turning path that connects the internal round-trip paths IPL is performed by automatic travel using a predetermined method. Note that the internal round-trip path IPL may be bent, in which case the internal round-trip path IPL will include multiple path elements.

[0042] In the outer peripheral area OA, a peripheral planting run is performed by going around the outer peripheral area OA one or more times along the outer periphery (outer edge) of the field FL. For example, two running routes, an inner circular route IRL and an outer circular route ORL, are generated as a route (target running route TL) for the peripheral planting run. The entire outer peripheral area OA is run by running the inner circular route IRL and the outer circular route ORL. The inner circular route IRL is run by unmanned automatic running or manned automatic running (automatic running with a person on board), and the outer circular route ORL is run by manual running or manned automatic running. In addition, a configuration may be adopted in which the inner circular route IRL is run by manual running or the outer circular route ORL is run by unmanned automatic running, depending on the mode selection.

[0043] Here, when changing the traveling direction of the machine body 1 at a corner of the field FL or the like during manual traveling around the periphery of the field FL (hereinafter simply referred to as "changing the traveling direction"), the machine body 1 travels as follows. As illustrated in FIG. 4, when changing the traveling direction at a corner of the field FL, first, the machine body 1 travels along the periphery of the field FL to the vicinity of the end (corner) of the field FL. The traveling at this time is as shown by the traveling trajectory ML1. Next, the machine body 1 moves backward as shown by the traveling trajectory ML2. Next, the steering handle 10 is operated, and the machine body 1 travels forward as shown by the traveling trajectory ML3. Then, the steering handle 10 is operated, and the machine body 1 travels backward to the terminal position of the traveling trajectory ML1 as shown by the traveling trajectory ML4. In FIG. 4, the backward traveling is indicated by a dashed line. This completes the change in the traveling direction of the machine body 1, and the machine body 1 travels along the periphery of the field FL as a traveling locus ML5, with the end position of the traveling locus ML1 becoming the starting position of the traveling locus ML5.

[0044] In addition, during the outer periphery travel, the vehicle position calculation unit 33 intermittently calculates the vehicle position P based on the positioning data acquired by the positioning unit 8, and stores it in the storage unit 40. Therefore, the vehicle position P is connected to a position along the travel trajectory (ML1 to ML5). The travel path calculation unit 35 does not use the vehicle position P on the travel trajectory (ML2 to ML4) related to the change in the traveling direction, but generates the outer circuit path ORL from an approximate straight line (previous travel path) calculated from a node LN that is at least a part of the vehicle position P on the travel trajectory ML1, and an approximate straight line (previous travel path) calculated from a node LN that is at least a part of the vehicle position P on the travel trajectory ML5. Therefore, the outer circuit path ORL is a path that approximately matches the travel trajectory ML1 and the travel trajectory ML5. That is, the outer circuit route ORL is generated along the travel locus ML1 and the travel locus ML5 that were actually traveled in a straight line during the outer periphery traveling, without taking into consideration the travel locus (ML2 to ML4) related to the change in traveling direction during the outer periphery traveling.

[0045] The travel route calculation unit 35 may extract the node LN from the calculated vehicle position P by any method, or may extract a predetermined number of vehicle positions P to be used as the node LN. The travel route calculation unit 35 may also generate a straight line connecting the vehicle positions P in the order of travel, and based on the angle between adjacent straight lines, delete the vehicle positions P whose angle with the straight line is equal to or smaller than a predetermined angle, thereby generating the node LN. In this case, when the vehicle 1 travels in a line close to a straight line, the nodes LN corresponding to the start and end positions are generated in the generated route elements.

[0046] In addition to the corners of the field FL, the outer periphery of the field FL may bend, and the traveling direction may be changed along the bent path. Also, there may be an obstacle OB (see FIG. 9) such as a water inlet at the edge of the field FL, and the traveling direction may be changed to avoid the obstacle OB during traveling around the periphery. For example, as shown in FIG. 5, when the outer periphery of the field FL is bent, the machine 1 travels straight along the outer periphery of the field FL (traveling path ML6), and then, near the bent part of the outer periphery, the steering wheel 10 is operated to change the traveling direction by moving forward (traveling path ML7), and then travels straight along the outer periphery of the field FL again (traveling path ML8).

[0047] 5, the travel path calculation unit 35 does not use the position P of the machine during travel related to the change in the traveling direction, but generates the outer circuit path ORL using at least a part of the position P of the machine on the travel path ML6 and the position P of the machine on the travel path ML8, which is the position P of the machine during straight line travel, as the node LN. That is, the outer circuit path ORL is generated from an approximate straight line (previously traveled travel path) calculated from the node LN on the travel path ML6 and an approximate straight line (previously traveled travel path) calculated from the node LN on the travel path ML8.

[0048] In peripheral travel in an area where the outer periphery of the field FL is curved or in peripheral travel to avoid an obstacle OB, the change in traveling direction is not limited to a change in traveling direction by moving forward, but may be a change in traveling direction by repeatedly moving forward and backward. In this case, too, the traveling path calculation unit 35 does not use the machine's position P (node ​​LN) related to the change in traveling direction in generating the outer circuit path ORL, but generates the outer circuit path ORL using the machine's position P on the traveling trajectory ML6 and the machine's position P (node ​​LN) on the traveling trajectory ML8.

[0049] Here, the outer circuit route ORL is not limited to being generated based on the travel path of the outer periphery travel as described above, but may also be generated based on a generated farm field map, similar to the inner circuit route IRL.

[0050] As shown in Fig. 6, the vehicle position calculation unit 33 converts the positioning data acquired by the positioning unit 8 to calculate the center of gravity CP of the vehicle 1 to be the vehicle position P. Since automatic driving is performed based on the vehicle position P, this center of gravity CP becomes the control point of the vehicle 1 during automatic driving. The center of gravity CP of the vehicle 1 is, for example, the center of the rear axle.

[0051] 7, during automatic traveling along a target traveling route TL, the traveling control unit 37 controls automatic traveling (automatic steering) based on a target orientation TD for a route element on the target traveling route TL and an orientation (traveling direction of the vehicle 1) of the vehicle 1 traveling along the route element. Specifically, the traveling control unit 37 automatically steers the vehicle 1 so that the orientation (traveling direction of the vehicle 1) of the vehicle 1 coincides with the target orientation TD in the route element corresponding to the position P of the traveling vehicle.

[0052] In the example of Fig. 7, while traveling along the first route element TL1 of the target travel route TL, the travel control unit 37 performs automatic steering so that the orientation of the vehicle 1 (travel direction of the vehicle 1) faces the target orientation TD1 in the first route element TL1. Then, when the vehicle 1 reaches the end position of the first route element TL1 (start position of the second route element TL2), which is the position where the target orientation TD changes (bending position, starting position of the travel direction change), the travel control unit 37 performs automatic steering (changing the travel direction) so that the orientation of the vehicle 1 (travel direction of the vehicle 1) faces the target orientation TD2 in the second route element TL2. In this way, the vehicle 1 automatically travels along the target travel route TL.

[0053] As described above, the traveling control unit 37 controls the automatic traveling along the target traveling route TL based on the target direction TD and the traveling direction of the vehicle 1 (the traveling direction of the vehicle 1). The target direction TD and the traveling direction of the vehicle 1 are determined based on the position P of the vehicle during traveling, so that the steering control (changing the traveling direction) based on the target direction TD2 in the second route element TL2 is started only when the vehicle 1 reaches the starting position (bending position, starting position of the traveling direction change) of the second route element TL2. Therefore, when traveling on the second route element TL2 is started, the steering control may be started with a delay, and if the angle (angle difference = bending angle) between the target direction TD of the adjacent route element corresponding to the angle between the adjacent route elements becomes large, the traveling direction may not be changed appropriately, and traveling along the route element after the traveling direction change may be difficult, especially at the beginning of traveling.

[0054] Therefore, when the traveling direction is changed based on the target heading TD, steering control is performed so that the traveling direction is appropriately changed. An embodiment of the steering control will be described below.

[0055] [Embodiment 1] Hereinafter, the steering control according to the first embodiment will be described with reference to FIGS. 2 to 5, 8 and 9. FIG.

[0056] In this embodiment, when traveling around the outer periphery, the steering angle SA of the steering wheel 10 is stored as a steering situation together with the vehicle position P. Then, when traveling automatically along a previously traveled route, automatic traveling control (steering control) is performed taking into account the steering angle SA at least when changing the traveling direction.

[0057] As shown in FIG. 5, there is a case where the vehicle changes its traveling direction from straight traveling along the field FL to an arc-like arc, and then starts traveling straight again. Since a linear traveling path is generated as the target traveling path TL, two linear outer circuit paths ORL are generated when the vehicle travels in this manner. However, when the traveling direction is changed, the actual traveling trajectory ML7 is located inside the outer circuit path ORL, as in the vehicle's position Pn. In other words, when traveling on the outer periphery, the traveling direction change starts just before the intersection of the two outer circuit paths ORL. As a result, when steering control is performed along the outer circuit path ORL, the traveling direction change starts from the intersection of the two outer circuit paths ORL, and the traveling direction change is delayed.

[0058] According to this embodiment, at least when changing the traveling direction, the steering angle SA of the steering wheel 10 during traveling on the outer circumference can be taken into consideration, so that the position where the steering wheel 10 starts to be operated can be taken into consideration and the steering control for changing the traveling direction can be started before the intersection point (the starting position of the traveling direction change) of the two outer loop routes ORL. As a result, the delay in the steering control is suppressed, and it becomes possible to perform automatic traveling along the target traveling route TL with high accuracy.

[0059] Specifically, as shown in FIG. 2, the control unit 30 further includes a steering situation acquisition section 50 (situation acquisition section).

[0060] The steering state acquisition unit 50 acquires the steering angle SA (steering state) of the steering wheel 10 during manual driving around the outer perimeter, and stores the acquired steering angle SA (steering state) in the memory unit 40 in association with the position P of the vehicle.

[0061] The driving control unit 37 has a normal mode and a steering consideration mode when performing automatic driving. The normal mode is a mode in which steering control is performed so that the target direction TD corresponding to the route element at the position P of the vehicle while traveling coincides with the traveling direction of the vehicle 1. The steering consideration mode is a mode in which steering control is performed taking into account the steering angle SA in addition to the position P and traveling direction of the vehicle 1 at least when changing the traveling direction.

[0062] During perimeter travel, when the machine body 1 is traveling along a straight portion of the perimeter of the field FL, the steering angle SA of the steering wheel 10 is in the fine adjustment range. During perimeter travel, when the machine body 1 is traveling along a curved area of ​​the perimeter of the field FL, the steering angle SA of the steering wheel 10 becomes large.

[0063] Therefore, while traveling on the outer loop route ORL, which is a previously traveled travel route, the traveling control unit 37 refers to the steering angle SA corresponding to the position P of the traveling body stored in the memory unit 40, and when it reaches a position where the steering angle SA is equal to or greater than a predetermined angle, or a predetermined distance before it reaches the position, it recognizes that it is an area where the traveling direction should be changed, and transitions to the steering consideration mode. Then, the traveling control unit 37 starts steering control so that the traveling direction is changed toward the target direction TD on the next outer loop route ORL (previously traveled travel route).

[0064] As a result, the change in direction of travel begins just before the starting point of the direction change, which is the intersection of adjacent outer loop routes ORL (route elements), thereby preventing delays in the start of the direction change and enabling accurate automatic travel along the outer loop route ORL after the direction change.

[0065] In addition, the transition to the steering consideration mode may not only be performed when the steering angle SA of the steering wheel 10 is equal to or greater than a predetermined angle, but may also be performed when the amount of change per unit time in the steering angle SA of the steering wheel 10 is equal to or greater than a predetermined value.

[0066] In addition, the transition to the steering consideration mode is not limited to the case where it is performed based on the steering angle SA of the steering wheel 10, but may be performed based on the target travel route TL, and the steering angle SA of the steering wheel 10 may be considered in the steering control in the steering consideration mode. In this case, the transition to the steering consideration mode is performed, for example, when the angle formed by the route elements before and after the intersection (start position of the travel direction change) of the adjacent outer loop routes ORL (route elements), or the angle formed by the target orientation TD corresponding to the route elements before and after the intersection (start position of the travel direction change) of the adjacent outer loop routes ORL (route elements) is a predetermined angle or more. Then, when the angle formed by the route elements before and after the intersection (start position of the travel direction change) of the adjacent outer loop routes ORL (route elements) or the angle formed by the target orientation TD is a predetermined angle or more, the traveling control unit 37 transitions to the steering consideration mode and starts changing the travel direction before the start position of the travel direction change in consideration of the steering angle SA.

[0067] In addition, an example has been described in which, in the steering consideration mode, the direction change starts just before the intersection of adjacent outer loop paths ORL (route elements). However, in the steering consideration mode, the start position of the direction change may not be changed, and steering control to change the direction of the aircraft 1 to the target orientation TD on the outer loop path ORL after the direction change may be performed more abruptly than in the normal mode.

[0068] In addition, the steering consideration mode is implemented when there is any change in the traveling direction, such as when the traveling direction is changed around a corner in the field FL.

[0069] For example, as shown in FIG. 4, when the vehicle is around a corner of a farm field FL, forward and reverse movements are repeated while the steering wheel 10 is operated.

[0070] During automatic travel on the outer loop path ORL, which is a previously traveled travel path, if the travel control unit 37 confirms that the steering situation is travel in which forward and reverse travel has been performed while the steering wheel 10 is operated, it can determine that the location is where a travel direction change has occurred and transition to a steering consideration mode. In addition, in the steering consideration mode, the travel control unit 37 can perform steering control such as starting steering control early or steering sharply according to the steering situation of forward and reverse travel and the amount of operation of the steering wheel 10 at that time (the steering angle SA, the amount of change in the steering angle SA, etc.).

[0071] [Another embodiment of the first embodiment] (1) The steering consideration mode is not limited to a configuration that adjusts steering control, and may be a configuration that corrects the target driving route TL. In other words, in order to perform automatic driving with high accuracy along the target driving route TL (outer loop route ORL) after the change in traveling direction, the driving control unit 37 may correct the outer loop route ORL (route element) before and after the change in traveling direction based on the steering situation so as to smoothly connect the outer loop route ORL (route element) before and after the change in traveling direction.

[0072] For example, as shown in Fig. 4, in the corner of the field FL, forward and backward travel is performed while operating the steering wheel 10 along trajectories such as travel trajectories ML2, ML3, and ML4 during peripheral travel. However, the outer circuit path ORL (path element) in the target travel path TL is calculated as an approximate straight line of the travel trajectories ML1 and ML5, as described above. Therefore, it is difficult to appropriately change the traveling direction, and automatic travel along the target travel path TL cannot be performed with high accuracy in some cases.

[0073] 5, in an area where the outer periphery of the field FL is curved, when traveling around the outer periphery, the direction of travel is changed while the steering wheel 10 is operated along a trajectory such as the traveling trajectory ML7. However, as described above, the outer circuit path ORL (path element) in the target traveling path TL is calculated as an approximate straight line of the traveling trajectory ML6 and the traveling trajectory ML8. Therefore, it is difficult to appropriately change the direction of travel, and automatic traveling along the target traveling path TL cannot be performed with high accuracy in some cases.

[0074] In the steering consideration mode in this embodiment, the driving control unit 37 predicts a driving route during outer circumference driving from the operation state of the steering wheel 10 during outer circumference driving. Then, the driving control unit 37 corrects the route elements before and after the change in traveling direction and the target direction TD based on the predicted driving route so as to smoothly connect the route elements before and after the change in traveling direction.

[0075] With this configuration, even if the target direction TD suddenly changes at an intersection of the driving routes, the target driving route TL is corrected so that the target direction TD changes gradually, so that the direction of travel can be appropriately changed and automatic driving can be performed along the target driving route TL with high accuracy.

[0076] (2) The steering consideration mode is not limited to a configuration in which steering control is adjusted, and may be a configuration in which a target driving path TL is generated when changing the traveling direction based on the steering situation.

[0077] When generating the target driving route TL, the driving route calculation unit 35 reads out the steering angle SA (steering situation) stored in the storage unit 40, and detects the traveling direction change point where the steering consideration mode should be changed as described above. When generating the target driving route TL at the traveling direction change point where it is determined that the steering consideration mode should be changed, the driving route calculation unit 35 generates the target driving route TL including the route elements related to the traveling direction change and the target direction TD as the steering consideration mode based on the steering situation.

[0078] For example, when a change in traveling direction is made by moving forward as shown in Fig. 5 during outer circumference traveling, the traveling route calculation unit 35 generates, in the steering consideration mode, one or more direction change routes TLR (previous traveling routes) that connect two outer loop routes ORL along the traveling route ML7 based on the steering situation during traveling along the traveling route ML7, as shown in Fig. 8. The direction change route TLR includes route elements and a target orientation TD corresponding to the route elements.

[0079] The travel route calculation unit 35 generates a direction change route TLR (previously traveled route) by sequentially connecting at least a portion of the vehicle positions P that were not used when generating the outer loop route ORL.

[0080] Similarly, when a change in direction of travel is made during outer periphery travel by moving forward and backward as shown in Figure 4, the travel path calculation unit 35 generates one or more direction change paths TLR along the travel trajectory ML2, the travel trajectory ML3, and the travel trajectory ML4.

[0081] By generating such a direction change route TLR, it is possible to generate a target driving route TL that is close to the driving locus in the outer circumference driving. As a result, automatic driving can be performed along the target driving route TL with high accuracy.

[0082] Here, in the outer circumference traveling, the traveling direction may be changed to avoid the obstacle OB. Since the obstacle OB needs to be avoided in the actual automatic traveling, it is appropriate to generate the direction change route TLR as the target traveling route TL.

[0083] For example, as shown in FIG. 9, when the direction of travel is changed by repeatedly moving forward and backward while operating the steering wheel 10 to avoid an obstacle OB, the travel path calculation unit 35 generates a direction change path TLR that follows the travel trajectory of the change in direction of travel based on the steering situation.

[0084] With this configuration, the target travel route TL is generated as a route that avoids the obstacle OB, and automatic travel along the target travel route TL can be performed to avoid the obstacle OB.

[0085] (3) In the first embodiment and each of the other embodiments, the steering situation can be the operation angle (steering angle SA) of the steering wheel 10 or the operation amount (change amount of the steering angle SA, etc.) of the steering wheel 10. In addition, the transition to the steering consideration mode may be performed not only by the steering situation but also by considering at least one of the steering situation, the wheel situation, and the vehicle orientation situation. The wheel situation is the steering angle (turn angle) of the front wheels 12A and the difference in the rotation speed of the left and right front wheels 12A. The vehicle orientation situation is the change situation of the traveling direction of the vehicle 1, and may be obtained from the change in the traveling direction of the vehicle 1 in the traveling trajectory in manual traveling obtained from the change in the vehicle position P, or may be obtained from the difference in the target orientation TD in the target traveling route TL. In this case, the control unit 30 includes a situation acquisition unit that acquires the wheel situation and the vehicle orientation situation. The steering situation acquisition unit 50 is an example of a situation acquisition unit, and the situation acquisition unit acquires at least one of the steering situation, the wheel situation, and the vehicle orientation situation. Furthermore, when crawlers are provided as a running device instead of the wheels 12, the difference in the rotation speed between the left and right crawlers is acquired as the wheel status. Also, a steering tool such as an operating lever may be used instead of the steering wheel 10, and the operating angle and operating amount of the steering tool can be used as the steering status.

[0086] (4) In the first embodiment and each of the other embodiments described above, the previously traveled travel route for implementing the steering consideration mode may be not only a route element along the travel route of the outer periphery travel, but also a route element along the travel route when traveling in the field FL before the work travel. For example, the inner round trip route IPL or the inner circular route IRL traveled in the rice planting work of the previous year or earlier may be set as the target travel route TL for the work travel to be performed this time. In this case, the steering situation when traveling on the inner round trip route IPL or the inner circular route IRL of the previous year or earlier is used in the steering consideration mode.

[0087] [Embodiment 2] Hereinafter, the steering control according to the second embodiment will be described with reference to FIG. 2, FIG. 10, and FIG.

[0088] In this embodiment, during automatic driving along the target driving route TL, a target orientation TD (current driving target orientation) in the currently traveling route element LC, which is the route element being driven, is combined with a target orientation TD (destination target orientation) in one or more route elements (destination route element LA) that are scheduled to be passed through later to generate a composite target orientation TDM, and automatic driving (automatic steering) is controlled so that the traveling direction of the vehicle 1 (see Figure 1) is aligned with the composite target orientation TDM in the currently traveling route element.

[0089] For example, the traveling control unit 37 generates a composite target orientation TDM by combining the target orientation during traveling and the destination target orientation of the next route element (destination route element LA) to be passed (adjacent in the traveling direction) and stores it in the storage unit 40. Then, the traveling control unit 37 controls the automatic traveling (automatic steering) so that the traveling direction of the vehicle 1 coincides with the composite target orientation TDM at the current traveling position.

[0090] With this configuration, the target direction TD (destination target direction) of the destination route element LA is taken into consideration when changing the direction of travel, so that a sudden change in direction of travel is prevented from occurring at the direction-changing point.

[0091] In the above configuration, the traveling control unit 37 may be further configured to generate the composite target direction TDM only when the lengths of the route elements before and after the change in traveling direction are equal to or shorter than a predetermined length.

[0092] Alternatively, the driving control unit 37 may set the target heading during driving and the target heading to a predetermined pro rata rate The ratio may be determined according to the distance between the current vehicle position P and the destination route element LA (starting point of the change in direction of travel), which is the route element to be traveled next.

[0093] In this case, as shown in FIG. 10, the closer the current vehicle position P is to the destination route element LA, the smaller the destination target heading becomes. pro rata rate increases. For example, when the distance from the current position P of the aircraft to the travel destination route element LA is n1, the pro rata rate : of the travel destination target azimuth pro rata rate = 80%: 20%, and when it is n2 (<n1), the pro rata rate : of the travel destination target azimuth pro rata rate = 70%: 30%, and when it is n3 (<n2), the pro rata rate : of the travel destination target azimuth pro rata rate = 60%: 40%. At the end of the travel route element LC during travel, the pro rata rate : of the travel destination target azimuth pro rata rate = 50%: 50%.

[0094] With such a configuration, at a position far from the travel destination route element LA, the influence of the travel destination target azimuth becomes small. Therefore, the combined target azimuth TDM gradually approaches the travel destination target azimuth, and a sharp change in the traveling direction is suppressed, and the traveling direction is appropriately changed. As a result, it is suppressed that the aircraft 1 deviates from the travel destination route element LA, and automatic travel along the target travel route TL is performed with high accuracy. Therefore, it is suppressed that the aircraft 1 bulges outward with respect to the travel destination route element LA, and contact with the ridges or obstacles OB (see FIG. 9) of the farm field FL is suppressed.

[0095] Note that when a plurality of travel destination target azimuths are combined, the travel control unit 37 sets the travel destination target azimuth that is farther from the travel route element LC during travel pro rata rate lower.

[0096] 〔Another Embodiment of Embodiment 2〕 (1) In Embodiment 2, as shown in FIG. 11, the travel control unit 37 may divide the travel route element LC during travel or the travel route element LC during travel and the travel destination route element LA at predetermined distances to generate a plurality of divided route elements TLD having predetermined lengths. The travel control unit 37 sets the divided target azimuth TDD of each divided route element TLD to the target azimuth TD of the travel route element LC during travel or the travel destination route element LA that is the division source.

[0097] Then, the driving control unit 37 generates a composite target heading TDM by combining the divided target headings TDD at least in the divided route elements TLD before and after the change in traveling direction. The driving control unit 37 controls the automatic driving (automatic steering) so that the traveling direction of the vehicle 1 becomes the composite target heading TDM in the divided route element TLD during traveling.

[0098] As in the second embodiment, the driving control unit 37 may set a proportional distribution ratio when generating the composite target direction TDM, and may change the proportional distribution ratio according to the distance to the traveling direction change point.

[0099] As described above, by dividing the route element to generate the divided route element TLD and generating the composite target heading TDM for the divided route element TLD, steering control can be performed closer to the travel direction change, and a more appropriate composite target heading TDM can be generated without being excessively influenced by the travel destination target heading. As a result, automatic travel along the target travel route TL can be performed with higher accuracy.

[0100] (2) In the above-mentioned alternative embodiment (1), the length of the divided route element TLD may be variable. For example, the length of the divided route element TLD may be shortened as it approaches the travel direction change point. This allows the composite target heading TDM to be generated with higher accuracy without being excessively affected by the travel destination target heading.

[0101] In addition, or at the same time, the length of the divided route element TLD may be increased as the difference in direction between the destination target direction of the destination route element LA and the current target direction of the current route element LC increases. This allows steering control to be started before the direction change as the angle of the direction change increases, and allows automatic driving along the target driving route TL to be performed with greater accuracy.

[0102] (3) In the above-mentioned embodiment 2 and other embodiments (1) and (2), the composite target direction TDM is not limited to being synthesized by the driving control unit 37, but may be synthesized by any functional block such as the driving route calculation unit 35. Similarly, the generation of the divided route elements TLD is not limited to being generated by the driving control unit 37, but may be synthesized by any functional block such as the driving route calculation unit 35.

[0103] [Another embodiment] (1) In each embodiment including the alternative embodiments, some or all of the functional blocks constituting the control unit 30 are not limited to being provided in the aircraft 1, but may be provided in an information terminal 5 or a management computer or the like that is provided outside the aircraft 1 and capable of communicating with the aircraft 1.

[0104] (2) In each embodiment including other embodiments, the control unit 30 is not limited to being composed of the above-mentioned functional blocks, and may be composed of any functional blocks. For example, each functional block of the control unit 30 may be further subdivided, or conversely, some or all of the functional blocks may be combined. In addition, the functions of the control unit 30 are not limited to the above-mentioned functional blocks, and may be realized by a method executed by any functional block. In addition, some or all of the functions of the control unit 30 may be composed of software. A program related to the software is stored in any storage device such as the storage unit 40, and is executed by a processor such as a CPU included in the control unit 30 or a processor provided separately. [Industrial Applicability]

[0105] The present invention can be applied not only to rice transplanters, but also to the automatic travel of various types of work vehicles that automatically travel on work land, including combine harvesters and tractors. [Explanation of symbols]

[0106] 1 Aircraft 33 Aircraft position calculation unit 35 Travel route calculation unit 37 Driving control unit LA Destination route element LC Running Route Element P Aircraft position TD target direction TDD split target direction TDM composite target orientation TL Target driving route TLD split path element

Claims

1. An automatic driving control system for a work vehicle that automatically drives along a target driving route, A vehicle position calculation unit that calculates the vehicle position and traveling direction of the vehicle; A travel route calculation unit that generates the target travel route; a travel control unit that controls the work vehicle to travel along the target travel route based on the vehicle body position and the travel direction, the target travel route generated by the travel route calculation unit includes a plurality of route elements and a target orientation that is an orientation along the target travel route for each of the route elements; The driving control unit generates a composite target orientation by combining the in-driving target orientation, which is the target orientation in the route element corresponding to the position of the work vehicle's body, and the destination target orientation, which is the target orientation corresponding to each of the destination route elements, which are one or more of the route elements that the work vehicle is scheduled to pass through later, and performs automatic driving control so that the driving orientation of the work vehicle in the route element becomes the composite target orientation.

2. The automatic driving control system of claim 1, wherein the composite target orientation is formed by combining each of the destination target orientations and the in-travel target orientations at a predetermined ratio, and the ratio of each of the destination target orientations becomes higher as the current position of the vehicle approaches the destination route element.

3. The automatic driving control system of claim 1, wherein the composite target orientation is a combination of the destination target orientation and the in-travel target orientation in the next destination route element that is scheduled to be passed, at a ratio determined according to the distance between the destination route element and the position of the vehicle.

4. 4. The automatic driving control system according to claim 2, wherein the allocation rate varies depending on a direction difference between the destination target direction and the current driving target direction, and the allocation rate of the destination target direction becomes higher as the direction difference becomes larger.

5. the travel route calculation unit divides each of the route elements at predetermined distances to set divided route elements, and generates a divided target orientation for each of the divided route elements; The automatic driving control system according to claim 1 , wherein the driving control unit generates the composite target orientation by combining the divided target orientations in at least the divided route elements before and after a change in the traveling direction.

6. The automatic driving control system according to claim 5 , wherein the distance varies depending on a difference in direction between the destination target direction and the current driving target direction, and the greater the difference in direction, the longer the distance becomes.

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