Agricultural work vehicle, automatic travel control program, recording medium recording automatic travel control program, automatic travel control method

Abstract

An agricultural work vehicle includes a body position calculation unit (52) that calculates a position of a body in a field surface delimited by a boundary object, i.e., a body position; a boundary-crossing prevention control unit (57b) that prohibits the body from traveling beyond a boundary line set to avoid contact between the body and the boundary object, based on the boundary line and the body position; a turning trajectory estimation unit (57c) that estimates a trajectory of the body when turning, i.e., a turning trajectory; and a boundary-crossing determination unit (57d) that determines whether the body will cross the boundary line in actual turning travel, based on the estimated turning trajectory.

Description

Technical Field

[0001] This invention relates to an agricultural vehicle that can travel automatically on field grounds defined by boundary markers. Background Technology

[0002] The agricultural vehicle described in Patent Document 1 includes: a measuring device that uses a satellite positioning system to detect the position of the vehicle; an automatic driving control unit that enables the vehicle to automatically drive along a set operating route; and an automatic deceleration unit that stops the vehicle when it approaches the boundary line between the field surface and the field ridge, i.e., the ridge line.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-117559 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] Agricultural vehicles, in order to navigate across fields defined by boundaries such as field ridges, repeatedly move forward towards the boundaries and turn (direction change) as they approach them. During turns, depending on the start time of the turn, the surface condition of the field, and the vehicle speed, the vehicle may sometimes turn along a path different from the intended one. For example, in the automatically driven agricultural vehicle described in Patent Document 1, when turning near the boundary line, if the vehicle turns closer to the boundary line than the intended path, its position will reach the boundary line, and the vehicle will stop abruptly. If the vehicle stops abruptly during automatic driving, manual driving is required to turn without crossing the boundary line. Such boundary-avoidance turns are time-consuming, thus delaying operations.

[0008] Therefore, it is desirable to have an agricultural vehicle that can avoid the situation of the vehicle having to stop abruptly due to the vehicle crossing the boundary line during automatic turning.

[0009] Solution for solving the problem

[0010] The agricultural vehicle of the present invention can drive automatically on a field defined by boundary objects. It includes: a body position calculation unit that calculates the position of the body on the field, i.e., the body position; an anti-boundary control unit that prevents the body from crossing the boundary line based on the boundary line set to avoid contact between the body and the boundary objects and the body position; a turning trajectory estimation unit that estimates the trajectory of the body when turning, i.e., the turning trajectory; and a turning boundary determination unit that determines whether the body will cross the boundary line during actual turning based on the estimated turning trajectory.

[0011] According to this structure, when the machine is turning, the turning trajectory is pre-estimated. Therefore, based on the estimated turning trajectory, it is determined whether the machine will cross the boundary line during the actual turning. The trajectory estimation by the turning trajectory estimation unit and the boundary crossing determination by the turning-time determination unit can be performed either before or during the actual turning, or both. If a determination result indicates that the boundary line will be crossed, a recovery process is performed before the machine's movement is prohibited by the boundary crossing control unit. This recovery process can be manual or automatic. Compared to performing recovery processing after the machine's movement has been prohibited by the boundary crossing control unit, this recovery process is not only easier to perform but also reduces time loss.

[0012] The recovery process refers to pausing the planned turn before the machine crosses the boundary line and performing a boundary avoidance turn by moving the starting point of the turn or changing the turning radius. Therefore, in one preferred embodiment of the present invention, when the boundary avoidance determination unit determines that the machine will cross the boundary line during the turn, a boundary avoidance turn is performed.

[0013] In an example of avoiding a boundary crossing while turning, if the predetermined turning angle is less than the maximum turning angle, a turning trajectory using the maximum turning angle is presumed. If the boundary crossing determination result is good when turning based on this presumed turning trajectory, crossing the boundary line can be avoided by turning at the maximum turning angle. Therefore, in one preferred embodiment of the present invention, the boundary crossing avoidance turning includes turning at the maximum turning angle. To more reliably avoid crossing the boundary line, it is preferable to use a reversing direction change (a type of turning), generally referred to as a turnaround. Accordingly, in one preferred embodiment of the present invention, the boundary crossing avoidance turning includes reversing.

[0014] In most agricultural operations performed in fields by agricultural vehicles, the field surface to be worked on is divided into an outer perimeter area and an inner area located inside the outer perimeter area. Operations in the inner area are performed by repeatedly driving straight for work and turning (mainly U-turns) for directional changes without actual work. Consequently, it is not uncommon for the vehicle to temporarily stop before transitioning from straight driving in the inner area to turning in the outer perimeter area. To utilize this control, in one preferred embodiment of the present invention, the field surface is divided into an outer perimeter area along the boundary line and an inner area located inside the outer perimeter area. Automatic driving operations in the inner area are performed by repeatedly driving straight in the inner area and turning in the outer perimeter area. When transitioning from straight driving to turning, the vehicle is temporarily stopped. During this temporary stop, the turning trajectory is estimated and boundary violation is determined. This effectively utilizes the temporary stop of the vehicle that occurs when transitioning from straight driving to turning. It should be noted that the term "straight-line driving" used in this invention not only means driving in a straight line, but also includes driving in a curved direction with a large radius of curvature.

[0015] Even if the trajectory of the turn is estimated before the turn and it is determined that the machine will not cross the boundary, it is still possible for the machine to cross the boundary due to slippage or other reasons during the turn. To avoid this, a boundary determination is performed even during the turn based on the estimated turning trajectory at that time. If it is determined that a boundary crossing will occur, the machine needs to be temporarily stopped and a new turn that avoids the boundary crossing needs to be initiated. Therefore, in one preferred embodiment of the present invention, if the boundary determination unit determines that the machine will cross the boundary line when passing through the turn midway through the turn, the machine stops and explores a new turn to avoid the boundary crossing.

[0016] Since control to avoid interference with boundary objects is based on the boundary line and the aircraft position, the boundary line calculation and the aircraft position calculation are preferably performed in the same way. Therefore, in one preferred embodiment of the present invention, the aircraft position calculation unit uses satellite positioning to calculate the aircraft position, and the position of the boundary line is calculated based on the aircraft position (trajectory) when traveling around the outermost perimeter of the field.

[0017] Furthermore, the automatic driving control program of the present invention is used for agricultural vehicles that can drive automatically on fields defined by boundary objects, and includes: a body position calculation function, which calculates the position of the body on the field, i.e., the body position; an anti-boundary-crossing control function, which prohibits the body from crossing the boundary line based on the boundary line set to avoid the body from contacting the boundary object and the body position; a turning trajectory estimation function, which estimates the trajectory of the body when turning, i.e., the turning trajectory; and a turning boundary-crossing determination function, which determines whether the body will cross the boundary line during actual turning based on the estimated turning trajectory.

[0018] Furthermore, the recording medium of the present invention records an automatic driving control program for an agricultural vehicle that can drive automatically on a field defined by boundary objects. The program includes: a body position calculation function, which calculates the position of the vehicle on the field, i.e., the body position; an anti-boundary-crossing control function, which prohibits the vehicle from crossing the boundary line based on the boundary line set to avoid contact between the vehicle and the boundary object and the body position; a turning trajectory estimation function, which estimates the trajectory of the vehicle when turning, i.e., the turning trajectory; and a turning boundary-crossing determination function, which determines whether the vehicle will cross the boundary line during actual turning based on the estimated turning trajectory.

[0019] Furthermore, the automatic driving control method of the present invention is used for agricultural vehicles that can drive automatically on field surfaces defined by boundary objects, and includes: a body position calculation step, which calculates the position of the body on the field surface, i.e., the body position; an anti-boundary control step, which prohibits the body from crossing the boundary line based on the boundary line set to avoid contact between the body and the boundary object and the body position; a turning trajectory estimation step, which estimates the trajectory of the body when turning, i.e., the turning trajectory; and a turning boundary determination step, which determines whether the body will cross the boundary line during actual turning based on the estimated turning trajectory. Attached Figure Description

[0020] Figure 1 This is a side view of a rice transplanter, an example of an agricultural work vehicle.

[0021] Figure 2 This is a flowchart illustrating the process of seedling transplanting achieved through automated driving.

[0022] Figure 3 This is a schematic diagram showing the configuration of the obstacle detector.

[0023] Figure 4 This is an explanatory diagram showing the division of fields into areas for setting driving paths.

[0024] Figure 5 This is an explanatory diagram illustrating the driving path of the rice transplanter set in the outer perimeter area and the movement of the rice transplanter.

[0025] Figure 6 This is an explanatory diagram illustrating the reciprocating travel path set within the internal area and the movement of the rice transplanter.

[0026] Figure 7 This is a functional block diagram representing the control system of a rice transplanter.

[0027] Figure 8 This is a flowchart representing an example of a boundary protection routine. Detailed Implementation

[0028] As an embodiment of the agricultural work vehicle of the present invention, a ride-on rice transplanter is adopted and will be described below. This rice transplanter can automatically travel on field surfaces whose boundaries are defined by boundary objects. It should be noted that, unless otherwise specified, in this specification, "front" refers to the front in the forward-backward direction (travel direction) of the machine body, and "rear" refers to the rear in the forward-backward direction (travel direction) of the machine body. In addition, left-right direction or lateral direction refers to the transverse direction of the machine body (the width direction of the machine body) orthogonal to the forward-backward direction of the machine body. "Up" or "down" refers to the positional relationship in the vertical direction of the machine body, indicating the relationship of height above the ground.

[0029] Figure 1 This is a side view of a rice transplanter. The rice transplanter is a ride-on type with a four-wheel drive chassis (hereinafter referred to as chassis 1). Chassis 1 includes: a parallel four-bar linkage mechanism 11 connected to the rear of chassis 1 in a lifting and swinging manner; a hydraulic lifting cylinder 11a that drives the linkage mechanism 11 to swing; a seedling planting device 3 (an example of an agricultural material dispensing device) connected to the rear end of the linkage mechanism 11 in a left-right swinging manner; and a fertilizer application device 4 mounted from the rear end of chassis 1 to the seedling planting device 3, etc.

[0030] As a mechanism for movement, the machine body 1 includes wheels 12, an engine 13, and a hydraulic continuously variable transmission (CVT) 14. The wheels 12 have steerable left and right front wheels 12A and non-steerable left and right rear wheels 12B. The engine 13 and the CVT 14 are mounted at the front of the machine body 1. Power from the engine 13 is supplied to the front wheels 12A, rear wheels 12B, etc., via the CVT 14.

[0031] One example of the seedling transplanting device 3 is an eight-row transplanting type. The seedling transplanting device 3 includes a seedling carrier platform 31, an eight-row transplanting mechanism 32, etc. It should be noted that the seedling transplanting device 3 can be changed to two-row transplanting, four-row transplanting, six-row transplanting, etc., by controlling the row clutches (not shown).

[0032] The seedling tray 31 is a platform for holding eight rows of blanket-shaped seedlings. The seedling tray 31 moves back and forth in the left-right direction with a fixed stroke corresponding to the left-right width of the blanket-shaped seedlings. The longitudinal conveying mechanism 33 conveys each blanket-shaped seedling on the seedling tray 31 longitudinally to its lower end at a predetermined interval each time the seedling tray 31 reaches the end of its left-right stroke. The eight planting mechanisms 32 are rotary and arranged in the left-right direction at fixed intervals corresponding to the planting row spacing. Furthermore, each planting mechanism 32, powered by the machine body 1, cuts one seedling from the lower end of each blanket-shaped seedling placed on the seedling tray 31 and plants it into the prepared soil.

[0033] The seedling transplanting device 3 has a seedling quantity adjustment function that adjusts the seedling quantity of the transplanting mechanism 32. The transplanting mechanism 32 passes through the seedling outlet formed by the guide rail that slides and guides the seedling carrier 31 at the lower end, and takes out one seedling for transplanting. The seedling quantity is adjusted by changing the position of the seedling carrier 31 and the guide rail that slides and guides the seedling carrier 31 at the lower end.

[0034] like Figure 1 As shown, the fertilization device 4 includes: a horizontally elongated hopper 41, a feeding mechanism 42, an electric blower 43, multiple fertilizer hoses 44, and furrow openers 45 installed in each row. The hopper 41 stores granular or powdered fertilizer. The feeding mechanism 42 operates using power transmitted from the engine 13, feeding two rows of fertilizer sequentially from the hopper 41. This fertilization device 4 has a feeding rate adjustment function to change the amount of fertilizer fed by the feeding mechanism 42.

[0035] Blower 43 operates using electricity from a battery (not shown) mounted on the main body 1, generating airflow to transport fertilizer delivered by each delivery mechanism 42 to the muddy surface of the field. The fertilizer application device 4 can switch between a working state, in which fertilizer stored in hopper 41 is supplied to the field in a predetermined amount, and a non-working state, in which the supply is stopped, by intermittently operating blower 43 and the like.

[0036] Each fertilizer hose 44 guides the fertilizer, delivered by a conveying air, to each furrow opener 45. Each furrow opener 45 is equipped with each land preparation float 15. Furthermore, each furrow opener 45 rises and falls together with each land preparation float 15. During operation, when each land preparation float 15 is on the ground, fertilizer furrows are formed in the soil of the paddy field, and fertilizer is guided into the fertilizer furrows.

[0037] The machine body 1 has a driver's section 20 at its rear. The driver's section 20 includes, as manual driving controls, a steering wheel 21 for front-wheel steering, a main gear lever 22 for adjusting vehicle speed via a continuously variable transmission (CVT) 14, a secondary gear lever 23 for operating the secondary transmission, and a control lever 25 for raising and lowering the seedling transplanting device 3 and switching its operating state. Furthermore, a universal terminal 9 is located in front of the driver's seat 16. The universal terminal 9 includes a notification device for displaying various information to inform the operator and a touch panel for accepting various information inputs. A driving mode switching control 24, operated by the driver, is located around the steering wheel 21. Additionally, a seedling preparation frame 17 for holding prepared seedlings is located in front of the driver's section 20.

[0038] The steering wheel 21 is connected to the front wheels 12A via a steering mechanism (not shown). Rotating the steering wheel 21 adjusts the steering angle of the front wheels 12A. The steering mechanism is also connected to a steering motor M1. During automatic driving, the steering motor M1 operates based on a steering signal, thereby adjusting the steering angle of the front wheels 12A. Furthermore, a shift control motor M2 is included for automatically operating the main shift lever 22. During automatic driving, the shift control motor M2 operates based on a shift signal, thereby adjusting the shift position of the continuously variable transmission 14.

[0039] An extension frame 17a extending upwards is provided on the upper part of the pre-seeded seedling frame 17.

[0040] The extended frame 17a is equipped with a stacked light 18 consisting of multiple colored lights arranged longitudinally to indicate the status of the rice transplanter, and a positioning unit 8. The positioning unit 8 outputs positioning data for calculating the position and orientation (body orientation) of the machine body 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 tilt and acceleration of the machine body 1 along its three axes.

[0041] Figure 2 This illustrates an example of the processing flow in a rice transplanting operation that combines automated and manual driving, implemented by this rice transplanter. Figure 2 In the example, the seedling planting operation includes pre-operation processing #A, map creation processing #B, boundary line calculation processing #C, path generation processing #D, operation start point guidance processing #E, inner reciprocating planting processing #F, and outer perimeter planting processing #H.

[0042] In pre-operation processing #A, communication checks are performed between the various units of the rice transplanter's control system, including the communication check of positioning unit 8. Furthermore, the use of remote control 90 (see reference) is also checked within the rice transplanter. Figure 1 Remote control of obstacle detector 80 (see reference) Figure 3The obstacle detection is implemented using [the system], therefore, the functional checks of the remote control 90 and the obstacle detector 80 are also performed as preprocessing. For example... Figure 3 As shown, the obstacle detector 80 in this embodiment is a sonar type, including four front sonars 80f that set the front of the body 1 as the detection range, two side sonars 80s that set the left and right sides of the body 1 as the detection range, and two rear sonars 80r that set the rear of the body 1 as the detection range.

[0043] Map production processing #B is the process of determining the shape of the field, which is the object of the operation, as a map. The rice transplanter calculates its travel trajectory along the outermost perimeter of the field, which is defined by boundary objects such as field ridges, based on the position signals obtained from the positioning unit 8 during manual driving (map production teaching driving). Based on this travel trajectory, the outline of the field, i.e., the field map, can be obtained as map information of the field.

[0044] like Figure 4 As shown, in boundary line calculation processing #C, based on the driving trajectory calculated through map creation processing #B, a boundary line representing the position of the machine body 1 is calculated as the limit to avoid contact between the rice transplanter and boundary objects in the field. During the normal operation of the rice transplanter, as long as the position of the machine body 1 does not cross this boundary line (also known as the boundary crossing line), the rice transplanter will not come into contact with boundary objects such as field ridges. If the position of the machine body 1 reaches the boundary line, the machine body 1 is forcibly stopped. Since the rice transplanter can drive automatically, a safety distance is added to determine the final position of the boundary line so that even if unexpected slippage, steering swaying, etc. occur, the rice transplanter will not come into contact with boundary objects such as field ridges.

[0045] In path generation process #D, a driving path is created within the field map created in map creation process #B, serving as the target for automated driving, according to a prescribed algorithm. The following explains the driving path generated for automated rice seedling planting operations.

[0046] like Figure 4 As shown, the field area defined by the field map is divided into an outer perimeter region and an inner region. The generated driving path includes a loop driving path set in the outer perimeter region (see...). Figure 5 ) and the reciprocating travel path set in the internal area (refer to Figure 6 The rice transplanter initially performs seedling planting operations in the inner area along a reciprocating travel path (a type of automatic travel operation) (referred to as the inner operation travel mode). Then, it performs seedling planting operations in the outer perimeter area along a circular travel path (referred to as the circular operation travel mode).

[0047] The circular driving path includes a straight path extending parallel to the field boundaries (field ridges) and paths involving forward and backward directional changes to connect the straight paths. It should be noted that... Figure 5 In this diagram, a straight path is designated R1, and a direction-changing path is designated R2. The reciprocating travel path includes many roughly parallel straight paths and U-shaped turning paths connecting these straight paths. Within each straight path, seedlings are planted starting at the planting beginning position (which is also the turning end position) and ending at the planting end position (which is also the turning beginning position). It should be noted that... Figure 6 In this system, the starting position of planting is assigned the symbol US, the ending position is assigned the symbol UF, the straight path is assigned the symbol R3, and the turning path is assigned the symbol R5. Figure 5 and Figure 6 In this context, the transition path used to change from a reciprocating travel path to a circular travel path is designated as R4. In this example, the transition path is similar to a turning path. Furthermore, in... Figure 5 and Figure 6 In the diagram, the working width of the rice transplanter is represented by the symbol W, and the entrance and exit of the rice transplanter into and out of the field are drawn with diagonal lines and given the symbol GA. Figure 6 The diagram shows the starting position of the journey from the entrance / exit to the reciprocating route (in...). Figure 6 The starting guide path (assigned by symbol S in the middle) Figure 6 The symbol R6 is used to indicate this. In turning paths, direction-changing paths, starting guidance paths, and turning paths, the rice transplanter travels without performing any work; therefore, these paths are represented by dashed lines. In looping straight paths and straight-line paths, the rice transplanter performs work while traveling; therefore, these paths are represented by solid lines.

[0048] In the operation start point guidance process #E, firstly, the rice transplanter manually drives through the entrance / exit into the field and stops at the designated location. Then, the rice transplanter automatically drives to the starting position along the starting guide path, which serves as the driving path to the starting point of the seedling planting operation.

[0049] In the inner reciprocating insertion treatment #F, the driving mode is the internal operation driving mode, along... Figure 6 The system automatically travels along the indicated reciprocating path to plant rice seedlings in the internal areas. When seedlings need to be replenished, a seedling replenishment process (#G) is performed.

[0050] When the inner reciprocating insertion treatment #F ends, the driving mode is switched to the circumferential operation driving mode, and the operation proceeds along... Figure 5The seedling planting operation along the illustrated circular driving path is referred to as the outer perimeter planting process #H. In this embodiment, the circular driving path includes an inner circular driving path for the initial inner loop and an outer circular driving path for the subsequent outer loop. Essentially, the outer circular driving path ends at the field's entrance / exit; therefore, after the seedling planting operation along the outer circular driving path, the rice transplanter leaves the field through the entrance / exit. The seedling planting operation along the inner circular driving path is performed under automatic driving conditions. The seedling planting operation along the outer circular driving path requires precise driving; therefore, even with automatic driving, it is preferable to have a manned automatic driving system with a driver acting as a monitor.

[0051] Figure 7 A control block diagram of the rice transplanter's control system is shown. The control system includes a control device 100 that controls various actions of the rice transplanter, a universal terminal 9 that can exchange data with the control device 100, and a remote controller 90. Signals from the positioning unit 8, driving mode switching operation unit 24, driving sensor group 28, work sensor group 29, and obstacle detector 80 are input into the control device 100. Control signals from the control device 100 are output to the driving equipment group 1A and the work equipment group 1B.

[0052] The driving equipment group 1A includes, for example, a steering motor M1 and a transmission operation motor M2. Based on the control signal from the control device 100, the steering angle is adjusted by controlling the steering motor M1 and the vehicle speed is adjusted by controlling the transmission operation motor M2.

[0053] The operating equipment group 1B includes, for example, a lifting cylinder 11a for adjusting the height of the seedling transplanting device 3, a seedling quantity adjustment device for adjusting the seedling quantity of the transplanting mechanism 32, and a delivery quantity adjustment device for changing the fertilizer delivery quantity of the delivery mechanism 42.

[0054] The driving sensor group 28 includes various sensors that detect states such as steering angle, vehicle speed, and engine speed, as well as their corresponding set values. The operation sensor group 29 includes various sensors that detect the states of the linkage mechanism 11, the seedling transplanting device 3, and the fertilization device 4.

[0055] The control device 100 includes a driving control unit 6, an operation control unit 51, a body position calculation unit 52, a driving path management unit 53, a driving control status sensing unit 55, a boundary crossing management unit 57, an input signal processing unit 50a, and a communication unit 50b.

[0056] The input signal processing unit 50a processes signals from various sensors, switches, rods, etc., installed on the rice transplanter and forwards them to the functional units constructed in the control device 100. The communication unit 50b has wireless communication capabilities, performs data communication with external devices, such as with the remote controller 90, and forwards the received data to the input signal processing unit 50a.

[0057] The driving control unit 6 includes an automatic driving control unit 6A, a manual driving control unit 6B, and a control management unit 6C. The automatic driving control unit 6A performs speed control and steering control during automatic driving. Steering control is performed by comparing the target driving path set by the driving path management unit 53 with the body position calculated by the body position calculation unit 52 to calculate the lateral deviation and azimuth deviation, thereby reducing the lateral deviation and azimuth deviation.

[0058] In addition to the automatic driving mode, which automatically travels along a target driving path, this rice transplanter also has a straight-line maintaining driving mode that automatically travels straight while maintaining the orientation of a baseline defined by at least two points. The baseline used in the straight-line maintaining driving mode can be the straight-line driving path managed by the driving path management unit 53.

[0059] In manual driving mode, the manual driving control unit 6B controls the steering motor M1 based on the amount of steering wheel 21 operation. The control management unit 6C selects one of the following modes based on the signal from the driving mode switching operation unit 24: automatic driving mode, straight-line maintaining driving mode, or manual driving mode.

[0060] The operation control unit 51 automatically controls the work equipment group 1B based on a pre-provided program during automatic driving, and controls the work equipment group 1B based on the driver's operation during manual driving. The body position calculation unit 52 calculates the map coordinates (body position) of the body 1 based on satellite positioning data sequentially sent from the positioning unit 8.

[0061] In this embodiment, the general-purpose terminal 9 includes a field information storage unit 91, a field map generation unit 92, a driving path generation unit 93, a boundary line calculation unit 94, and a driving trajectory generation unit 95. The field information storage unit 91 stores information related to the field, such as the type of crops planted, the location of the field's entrance (exit), and the location where seedlings can be replenished. The field map generation unit 92 performs... Figure 2 The map creation process has been explained. The driving path generation unit 93 divides the field into outer and inner areas based on the field map created by the field map creation unit 92, generating a circular driving path for driving in the outer area and a reciprocating driving path for driving in the inner area. The boundary line calculation unit 94 performs... Figure 2The boundary line calculation process has been explained. In the map production process implemented by the field map production unit 92 and the boundary line calculation process implemented by the boundary line calculation unit 94, it is necessary to produce a driving trajectory for the map production demonstration. The driving trajectory generation unit 95 generates the driving trajectory of the machine 1 based on the machine position calculated by the machine position calculation unit 52.

[0062] The driving path management unit 53 receives the driving path generated by the driving path generation unit 93 from the general terminal 9 for management, and sequentially sets the driving path as the target for the machine body to turn in automatic driving mode.

[0063] The driving control status sensing unit 55 senses the driving control status and the operation control status based on the control information processed by the control device 100.

[0064] The boundary management unit 57 has the function of preventing the machine body 1 from coming into contact with boundary objects such as field ridges because the machine body 1 crosses the boundary line (boundary line data) calculated by the boundary line calculation unit 94.

[0065] Therefore, the boundary management unit 57 includes a boundary line storage unit 57a, a boundary crossing prevention control unit 57b, a turning trajectory estimation unit 57c, and a boundary crossing determination unit 57d when turning.

[0066] Boundary line storage unit 57a stores the boundary lines received from boundary line calculation unit 94. Anti-boundary control unit 57b determines whether the machine 1 will cross the boundary line based on its position and sends a stop command to driving control unit 6, prohibiting the machine 1 from crossing the boundary line. Anti-boundary control unit 57b has a straight-line anti-boundary mode for preventing the machine 1 from crossing the boundary line while traveling straight and a turning anti-boundary mode for preventing the machine 1 from crossing the boundary line while turning.

[0067] In the straight-ahead anti-boundary mode, the anti-boundary control unit 57b calculates the distance between the vehicle body 1 and the boundary line based on the vehicle body position received from the vehicle body position calculation unit 52 and the boundary line opposite to the vehicle body read from the boundary line storage unit 57a. If the calculated distance is within a specified distance, the anti-boundary control unit 57b sends a stop command to the driving control unit 6.

[0068] When turning, the rear or front end of the machine body 1 swings laterally. Therefore, instead of using anti-crossing control based on spacing calculations, as in the straight-line anti-crossing mode, anti-crossing control is implemented using a turning anti-crossing mode. In this turning anti-crossing mode, anti-crossing control based on the estimated turning trajectory of the machine body 1 is performed using a turning trajectory estimation unit 57c and a turning-time cross-boundary determination unit 57d. The turning trajectory estimation unit 57c estimates the trajectory of the machine body 1 during turning, i.e., the turning trajectory. The turning-time cross-boundary determination unit 57d determines, based on the estimated turning trajectory, whether the machine body will cross the boundary line during the actual turning.

[0069] Next, use Figure 8 The flowchart below explains the anti-boundary control routine (anti-boundary routine) implemented by the boundary management unit 57. In this routine, firstly, it checks whether the start of turning is approaching (#01) based on the set driving path for automatic driving.

[0070] If the start of the turn is not imminent, repeat step #01. If the turn is about to begin (#01 is a branch), further check whether at least a portion of the vehicle 1 has entered a pre-defined boundary crossing prevention zone (in the embodiment, this may be the area between the boundary crossing prevention line and a boundary object such as a field ridge, located on the inner side of the boundary crossing line, or the aforementioned outer perimeter area) (#02). If the vehicle 1 is outside the boundary crossing prevention zone (#02 "outer" branch), return to step #01. If the vehicle 1 is inside the boundary crossing prevention zone (#02 "inner" branch), perform the following boundary crossing determination process before the turn.

[0071] In the pre-turn boundary determination process, the turning trajectory during the turn is estimated by the turning trajectory estimation unit 57c based on the machine's position and the steering angle used during the turn (#11). Then, the turning boundary determination unit 57d determines whether the machine 1 will cross the boundary line during the actual turn based on the estimated turning trajectory (#12). If the boundary determination result is "no boundary crossing" (#12 "no boundary crossing" branch), the turn is allowed (#21), and the turn begins (#22).

[0072] If the boundary violation determination result is "boundary violation" (#12 "boundary violation" branch), the boundary violation prevention control unit 57b sets a first boundary violation avoidance turn to avoid boundary violation (#13), and the turning trajectory under this set boundary violation avoidance turn is estimated by the turning trajectory estimation unit 57c (#14). Based on the estimated turning trajectory, it is determined whether the machine 1 will cross the boundary line during the boundary violation avoidance turn (#12). If the boundary violation determination result is "no boundary violation" (#12 "no boundary violation" branch), then the boundary violation avoidance turn is allowed (#21), and the turn begins (#22). If the boundary violation determination result is "boundary violation" (#12 "boundary violation" branch), then return to step #13 and set a second boundary violation avoidance turn. Boundary violation avoidance using reversing (so-called turnaround) is reliable boundary violation avoidance, but time loss occurs. Only forward boundary violation avoidance (turning using the maximum steering angle and the speed difference between the left and right wheels) is not reliable boundary violation avoidance, but there is no time loss. Therefore, the first boundary avoidance turn uses only forward boundary avoidance driving, while the second boundary avoidance turn uses reverse boundary avoidance driving.

[0073] When a turn begins, the system checks whether the turn has ended (#23) based on information from the driving control state sensing unit 55. If the turn has ended (#23 is a branch), the system returns to step #01 and repeats the boundary crossing prevention routine. If the turn is in progress (#23 is a no branch), the following boundary crossing determination process is performed.

[0074] In the boundary violation determination process during a turn, firstly, an actual boundary violation determination is performed to determine whether at least a part of the machine body 1 has crossed the boundary at the current position (#31). If the result of the actual boundary violation determination is "not crossed the boundary" (#31 "not crossed the boundary" branch), then the process returns to step #23 and continues turning. If the result of the actual boundary violation determination is "crossed the boundary" (#12 "crossed the boundary" branch), then the boundary violation prevention control unit 57b sends a stop command to the driving control unit 6, and the machine body 1 stops (#33). Next, the boundary violation prevention control unit 57b sets a boundary avoidance turn that uses reversing to move away from the boundary line (#34), and the turning trajectory under this set boundary avoidance turn is estimated by the turning trajectory estimation unit 57c (#35). Based on the estimated turning trajectory, it is determined whether the machine body 1 will cross the boundary line during the boundary avoidance turn (#36). If the boundary violation determination result is "no boundary violation" (#36 "no boundary violation" branch), then the boundary violation is allowed to avoid turning, turning resumes (#37), and control returns to step #23.

[0075] If the boundary violation determination result is "boundary violation" (#12 "boundary violation" branch), a warning (#41) is reported via general terminal 9 that the machine 1 cannot detach from the boundary line under automatic driving. At the same time, the automatic driving is deactivated (#42), ending the boundary violation prevention routine. Then, the boundary violation prevention control is disconnected, and the machine 1 is manually driven, carefully moving it away from the boundary line while avoiding interference with boundary objects.

[0076] In step #02, if the state of machine 1 is about to start turning and machine 1 has entered the anti-crossing zone, machine 1 can be temporarily stopped before proceeding to the next step.

[0077] [Other Implementation Methods]

[0078] (1) In the above embodiment, in steps #13, #14 and #15, as a boundary avoidance turning, the first boundary avoidance turning with only forward movement and the second boundary avoidance turning with backward movement are used in sequence, but the second boundary avoidance turning can also be used only.

[0079] (2) In the above embodiment, the field map generation unit 92, the driving path generation unit 93, the boundary line calculation unit 94, and the driving trajectory generation unit 95 are constructed in the general terminal 9, but at least a part of them may be constructed in the control device 100. Moreover, they may also be constructed in an external management computer that can exchange data with the control device 100.

[0080] (3) The steering angle in the turning path implemented by the automatic driving control unit 6A can be controlled by controlling along the generated turning path, or it can be controlled by controlling a predetermined steering angle, so as to obtain a specified turning path.

[0081] (4) In the above embodiments, a rice transplanter is used as the working vehicle, but it can also be a combine harvester, tractor, direct seeding machine, spray (dispersing) management machine or other agricultural working vehicle.

[0082] (5) It can also be configured as an automatic driving control program that enables the computer to perform the functions of each component in the above embodiments. Furthermore, it can be configured as a recording medium that records the automatic driving control program that enables the computer to perform the functions of each component in the above embodiments. Additionally, it can be configured as an automatic driving control method that performs the work done by each component in the above embodiments through one or more steps.

[0083] It should be noted that the structures disclosed in the above embodiments (including other embodiments, and the same applies below) can be used in combination with the structures disclosed in other embodiments as long as there is no conflict. In addition, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope without departing from the purpose of the present invention.

[0084] Industrial availability

[0085] This invention can be applied to agricultural vehicles that can drive automatically.

[0086] Explanation of reference numerals in the attached figures:

[0087] 1: Body

[0088] 6: Driving Control Unit

[0089] 8: Positioning Unit

[0090] 8A: Satellite Positioning Module

[0091] 8B: Inertial Measurement Module

[0092] 9: General-purpose terminal

[0093] 52: Body Position Calculation Unit

[0094] 53: Driving Route Management Department

[0095] 55: Driving control status sensing unit

[0096] 57: Boundary Management Department

[0097] 57a: Boundary Line Storage Unit

[0098] 57b: Border Crossing Control Unit

[0099] 57c: Turning trajectory estimation section

[0100] 57d: Boundary crossing detection unit during turning

[0101] 94: Boundary Line Calculation Department

[0102] 95: Driving trajectory generation unit

[0103] 100: Control device.

Claims

1. An agricultural vehicle that can travel automatically on field ground bounded by boundary markers, characterized in that, have: The machine body position calculation unit calculates the machine body's position on the field surface, i.e., the machine body position. The boundary crossing control unit, based on the boundary line set to avoid the machine body from contacting the boundary object and the position of the machine body, prohibits the machine body from crossing the boundary line; The turning trajectory estimation unit estimates the turning trajectory of the machine body during turning; and The boundary crossing determination unit, based on the estimated turning trajectory, determines whether the machine will cross the boundary line during actual turning. The turning trajectory estimation unit estimates the turning trajectory, and the boundary violation determination unit determines the turning trajectory at any one or both before the actual turning and during the actual turning. If the boundary determination unit determines that the machine body has crossed the boundary line when passing through the turn, the machine body will perform a boundary avoidance turn before the boundary control unit prohibits the machine body from moving.

2. An agricultural vehicle that can travel automatically on field ground bounded by boundary markers, characterized in that: have: The machine body position calculation unit calculates the machine body's position on the field surface, i.e., the machine body position. The boundary crossing control unit, based on the boundary line set to avoid the machine body from contacting the boundary object and the position of the machine body, prohibits the machine body from crossing the boundary line; The turning trajectory estimation unit estimates the turning trajectory of the machine body during turning; and The boundary crossing determination unit, based on the estimated turning trajectory, determines whether the machine will cross the boundary line during actual turning. If the boundary determination unit determines that the machine will cross the boundary line during the turn, a boundary avoidance turn is performed, which includes turning at the maximum steering angle.

3. The agricultural operation vehicle according to claim 1 or 2, characterized in that, The phrase "avoiding the boundary while turning" includes reversing.

4. The agricultural vehicle according to claim 1 or 2, characterized in that, The field is divided into an outer perimeter area along the boundary line and an inner perimeter area located inside the outer perimeter area. The automatic driving operation in the inner perimeter area is carried out by repeatedly performing straight driving in the inner perimeter area and turning driving in the outer perimeter area. When changing from straight driving to turning driving, the machine is temporarily stopped. During the temporary stop, the turning trajectory is estimated and boundary crossing is determined when turning.

5. The agricultural operation vehicle according to claim 1 or 2, characterized in that, If, during the course of a turn, the boundary determination unit determines that the machine will cross the boundary line, the machine will stop and explore a new way to avoid the turn.

6. The agricultural operation vehicle according to claim 1 or 2, characterized in that, The aircraft position calculation unit uses satellite positioning to calculate the aircraft position, and the position of the boundary line is calculated based on the aircraft position when traveling around the outermost perimeter of the field.

7. An automatic driving control program for an agricultural vehicle capable of automatic driving on field grounds defined by boundary markers, characterized in that, include: The machine body position calculation function calculates the machine body's position on the field surface, i.e., the machine body's position. The boundary crossing control function, based on the boundary line set to avoid the machine body from contacting the boundary object and the position of the machine body, prohibits the machine body from crossing the boundary line; The turning trajectory estimation function estimates the turning trajectory of the machine body during turning; and The boundary crossing detection function during turning determines whether the machine will cross the boundary line during actual turning based on the estimated turning trajectory. The turning trajectory estimation function and the boundary violation determination function during the turn are performed at either or both before the actual turn and during the actual turn. If the boundary crossing determination function determines that the machine body has crossed the boundary line when turning, the machine body will perform a boundary avoidance turn before the boundary crossing control function is used to prohibit the machine body from driving.

8. A recording medium containing an automatic driving control program, wherein the program is used to automatically drive an agricultural vehicle on field ground defined by boundary markers, characterized in that, The automatic driving control program includes: The machine body position calculation function calculates the machine body's position on the field surface, i.e., the machine body's position. The boundary crossing control function, based on the boundary line set to avoid the machine body from contacting the boundary object and the position of the machine body, prohibits the machine body from crossing the boundary line; The turning trajectory estimation function estimates the turning trajectory of the machine body during turning; and The boundary crossing detection function during turning determines whether the machine will cross the boundary line during actual turning based on the estimated turning trajectory. The turning trajectory estimation function and the boundary violation determination function during the turn are performed at either or both before the actual turn and during the actual turn. If the boundary crossing determination function determines that the machine body has crossed the boundary line when turning, the machine body will perform a boundary avoidance turn before the boundary crossing control function is used to prohibit the machine body from driving.

9. An automatic driving control method for an agricultural vehicle capable of automatic driving on field surfaces defined by boundary objects, characterized in that, include: The steps for calculating the body position are as follows: calculate the body's position on the field surface, i.e., the body position. The boundary crossing control steps, based on the boundary line set to avoid the machine body from contacting the boundary object and the position of the machine body, prohibit the machine body from crossing the boundary line; The turning trajectory estimation step involves estimating the trajectory of the machine body during turning, i.e., the turning trajectory; and The boundary crossing determination step during turning involves determining, based on the estimated turning trajectory, whether the machine will cross the boundary line during actual turning. The step of estimating the turning trajectory and the step of determining the boundary violation during the turn are performed either before the actual turn or during the actual turn, or both. If the boundary determination step determines that the machine body has crossed the boundary line when turning, the machine body will perform a boundary avoidance turn before the boundary control step prohibits the machine body from moving.

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