Autonomous driving system

Abstract

An autonomous travel system has a path generating section, an advance control section, a retreat control section, and a turn control section. The path generating section generates a plurality of straight paths. The advance control section autonomously performs at least steering manipulation to travel the rice transplanter along the straight paths while the rice transplanter is performing work. After an operator stops the rice transplanter traveling toward a field edge, the retreat control section does not cause the rice transplanter to perform work and retreats the rice transplanter autonomously or according to an operator's operation. With a condition that the rice transplanter retreated by the retreat control section is stopped by the operator or autonomously and there is an advance instruction by the operator, the turn control section does not cause the rice transplanter to perform work and turns the rice transplanter along a straight path designated in advance by autonomously performing at least steering manipulation.

Description

[0001] This application is a divisional application of application number 201980082708.7, which entered the national phase on June 11, 2021, and is entitled "Autonomous Driving System". Technical Field

[0002] This invention mainly relates to an autonomous driving system that enables work vehicles to drive autonomously. Background Technology

[0003] Patent Document 1 discloses a structure that generates a driving path including straight paths arranged in a field and turning paths connecting the straight paths, and enables a work vehicle to drive autonomously along the driving path. Furthermore, the work vehicle performs work on the field while traveling along the straight paths, and does not perform work on the field while traveling along the turning paths.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-117560

[0005] However, in cases where the turning of the work vehicle begins at a predetermined position, as in Patent Document 1, a position with a margin of safety is set as the starting position for the turn in order for the work vehicle to turn reliably and properly. As a result, the area in which the work vehicle operates along a straight path in the field becomes narrower. Summary of the Invention

[0006] The present invention was made in view of the above-mentioned reasons, and its main objective is to provide a structure in an autonomous driving system that enables the work vehicle to drive autonomously in the field, which can expand the area in which the work vehicle operates along a straight path.

[0007] The problem that this invention aims to solve is as described above. The means used to solve this problem and their effects will be explained below.

[0008] According to the technical solution of the present invention, an autonomous driving system with the following structure is provided. That is, the autonomous driving system includes a path generation unit, a forward control unit, a reverse control unit, and a turning control unit. The path generation unit generates multiple straight paths arranged side-by-side in a field. The forward control unit, while enabling the work vehicle to perform operations, autonomously performs steering maneuvers to make the work vehicle travel along the aforementioned straight paths. After the operator stops the work vehicle traveling towards the edge of the field, the reverse control unit prevents the work vehicle from performing operations and, based on the operator's operation, autonomously reverses the work vehicle. If, after the work vehicle reversing with the aid of the reverse control unit is stopped by the operator or autonomously, and there is a forward instruction based on the operator, the turning control unit prevents the work vehicle from performing operations and, at least autonomously, performs steering maneuvers to make the work vehicle turn towards the pre-designated straight path.

[0009] Therefore, by having the operator stop the work vehicle near the edge of the field, work can be carried out until the work vehicle stops near the edge of the field more autonomously. As a result, the area where the work vehicle can work along a straight path can be expanded. In addition, by making the forward instruction from the operator one of the conditions for starting a turn, the operator's instructions can be simplified, and turns can be started at an earlier time.

[0010] In the aforementioned autonomous driving system, preferably, the aforementioned turning control unit causes the aforementioned work vehicle to turn along the turning path by setting a turning path connected to the aforementioned pre-specified straight path.

[0011] Therefore, by setting a turning path, the work vehicle can be turned onto a straight path more reliably.

[0012] In the aforementioned autonomous driving system, preferably, the aforementioned reversing control unit does not cause the aforementioned work vehicle to perform work, but at least autonomously performs steering operations to cause the aforementioned work vehicle to reverse along the aforementioned straight path.

[0013] Therefore, since the working vehicle passes through approximately the same position when moving forward and backward, it is possible to prevent the generation of driving tracks in unnecessary locations.

[0014] In the aforementioned autonomous driving system, the following structure is preferred: The autonomous driving system includes a calculation unit and a reporting unit. The calculation unit calculates the distance traveled by the work vehicle, i.e., a first distance, during the period when the measurement conditions are met, while the work vehicle is traveling towards the edge of the field. The reporting unit reports information related to the stopping position of the work vehicle to the operator based on the first distance while the work vehicle is reversing using the reversing control unit.

[0015] Therefore, when the operator stops the work vehicle while reversing, the system can notify the operator of the position where the work vehicle should stop.

[0016] In the aforementioned autonomous driving system, the following structure is preferred: The calculation unit, based on the first distance, also calculates a condition related to the distance from the work vehicle to the edge of the field, i.e., a distance condition. This distance condition is also included as a condition for the turning control unit to initiate a turn of the work vehicle.

[0017] Thus, for example, one can avoid starting a turn when too close to the edge of a field, thereby preventing forced turns from occurring. Attached Figure Description

[0018] Figure 1 This is a side view of a rice transplanter that becomes the object of autonomous driving in the autonomous driving system according to the first embodiment.

[0019] Figure 2 This is a top view of a rice transplanter.

[0020] Figure 3 This is a block diagram of a rice transplanter and a wireless communication terminal.

[0021] Figure 4 It is a diagram representing the driving path generated by the path generation unit.

[0022] Figure 5 This is a flowchart illustrating the process of making the rice transplanter turn near the edge of the field.

[0023] Figure 6 It is a diagram showing how a rice transplanter turns near the edge of a field.

[0024] Figure 7 This is a diagram showing the processing performed in another turning process.

[0025] Figure 8 This is a block diagram of the rice transplanter and wireless communication terminal according to the second embodiment.

[0026] Figure 9 This is a flowchart illustrating the process of turning the rice transplanter near the edge of the field in the second embodiment.

[0027] Figure 10 This diagram shows the rice transplanter turning near the edge of the field in the second embodiment. Detailed Implementation

[0028] Next, embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a side view of the rice transplanter 1 used in the autonomous driving system 100 according to the first embodiment of the present invention. Figure 2 This is a top view of rice transplanter 1. Figure 3 This is a block diagram of the rice transplanter 1 and the wireless communication terminal 7.

[0029] The autonomous driving system 100 of this embodiment uses a rice transplanter 1 as a work vehicle for operating in the field, and the operator gives instructions using a wireless communication terminal 7 or the like, thereby enabling the rice transplanter 1 to drive autonomously while performing agricultural operations (such as seedling transplanting). Alternatively, autonomous driving instructions can be given by operating a control device installed on the rice transplanter 1 or other work vehicle instead of operating the wireless communication terminal 7. Furthermore, the work vehicle in this invention is not limited to a rice transplanter 1; for example, a seeder, tractor, combine harvester, etc., can be used.

[0030] Autonomous driving refers to controlling the driving-related devices using the control unit of the rice transplanter 1, thereby autonomously performing steering maneuvers to follow a predetermined path. Alternatively, it can also involve autonomously adjusting vehicle speed or operating the machine based on steering maneuvers. Autonomous driving includes both situations where a person is riding in the rice transplanter 1 and situations where a person is not riding in the rice transplanter 1.

[0031] like Figure 1 and Figure 2 As shown, the rice transplanter 1 includes a body section 11, front wheels 12, rear wheels 13, and a planting section (operating section) 14. The front wheels 12 and the rear wheels 13 are respectively provided in a left and right pair relative to the body section 11.

[0032] The vehicle body 11 has an engine hood 21. The engine hood 21 is located at the front of the vehicle body 11. An engine 22 is located inside the engine hood 21.

[0033] The power generated by the engine 22 is transmitted to the front wheels 12 and the rear wheels 13 via the gearbox housing 23. This power is also transmitted to the mounting section 14 via the gearbox housing 23 and the PTO shaft 24 located at the rear of the vehicle body 11.

[0034] The vehicle body 11 also includes a driver's seat 25 and multiple operating components. An operator can sit in the driver's seat 25. The driver's seat 25 is positioned between the front wheels 12 and the rear wheels 13 in the longitudinal direction of the vehicle body 11. The multiple operating components include a steering wheel 26, a gear shift pedal 27, a main gear lever 28, and a clutch lever 29.

[0035] The rice transplanter 1 can be steered by operating the steering wheel 26. The travel speed (vehicle speed) of the rice transplanter 1 can be adjusted by operating the gear shift pedal 27. The main gear lever 28 is configured to select "forward," "reverse," and "stop," for example. When the main gear lever 28 is operated to the "forward" position, power is transmitted to the rear wheel 13 in the direction that propels the rice transplanter 1 forward. Conversely, when the main gear lever 28 is operated to the "reverse" position, power is driven to the rear wheel 13 in the direction that propels the rice transplanter 1 backward. When the main gear lever 28 is operated to the "stop" position, power transmission to the front wheel 12 and rear wheel 13 is cut off. Furthermore, the "forward" position can be divided into a "low speed" for driving within the field and a "high speed" for driving outside the field. By operating the insertion clutch lever 29, it is possible to switch between the power transmission state of the insertion clutch transmitting power to the PTO shaft 24 (i.e., insertion part 14) and the cut-off state of the insertion clutch not transmitting power to the PTO shaft 24 (i.e., insertion part 14).

[0036] The insertion part 14 is located at the rear of the vehicle body part 11. The insertion part 14 is connected to the vehicle body part 11 via a lifting linkage mechanism 31. The lifting linkage mechanism 31 is composed of parallel links including an upper link 31a and a lower link 31b.

[0037] In the lifting linkage mechanism 31, a lifting cylinder 32 of the lifting device is connected to the lower linkage 31b. The aforementioned lifting device can raise and lower the insertion part 14 relative to the vehicle body part 11 by extending and retracting the lifting cylinder 32. In this embodiment, the lifting cylinder 32 is a hydraulic cylinder, but it can also be an electric cylinder. In addition, the aforementioned lifting device can also raise and lower the insertion part 14 by means of an actuator other than the cylinder.

[0038] The planting section 14 includes a planting input box 33, multiple planting units 34, a seedling platform 35, multiple floats 36, and a pre-planting platform 37. The planting section 14 can sequentially supply seedlings to each planting unit 34 from the seedling platform 35, and continuously plant seedlings.

[0039] Each insertion unit 34 has an insertion transmission box 41 and a rotation box 42. Power is transmitted to the insertion transmission box 41 via the PTO shaft 24 and the insertion input box 33.

[0040] The rotating housing 42 is rotatably mounted on the insertion transmission housing 41. The rotating housing 42 is arranged on both sides of the insertion transmission housing 41 in the vehicle width direction. Two insertion claws 43 are mounted on one side of each rotating housing 42.

[0041] Two planting claws 43 are arranged in the direction of travel of the rice transplanter 1. The two planting claws 43 are displaced as the rotating box 42 rotates. By displacing the two planting claws 43, one row of seedlings is planted.

[0042] A seedling tray 35 is positioned above and in front of multiple planting units 34. The seedling tray 35 is capable of holding seedling mats. The seedling tray 35 is configured to supply seedlings placed on the seedling mats to each planting unit 34.

[0043] Specifically, the seedling platform 35 is configured to move laterally in a reciprocating manner in the vehicle width direction (it can slide laterally). In addition, the seedling platform 35 is configured to intermittently feed and transport the seedling pads downward longitudinally at the reciprocating end of the seedling platform 35.

[0044] The float 36 is oscillatingly disposed at the lower part of the planting section 14. In order to stabilize the planting posture of the planting section 14 relative to the field surface, the lower surface of the float 36 can be in contact with the field surface.

[0045] A pair of pre-planting seedling platforms 37 are provided on the left and right sides relative to the vehicle body 11. The pre-planting seedling platforms 37 are located on the outer side of the engine hood 21 in the vehicle width direction. The pre-planting seedling platforms 37 can hold seedling boxes that contain prepared pad-shaped seedlings.

[0046] The upper parts of a pair of left and right preparatory seedling platforms 37 are connected to each other by a connecting frame 15 extending in the vertical and horizontal directions and the vehicle width direction. A frame 16 is provided in the center of the connecting frame 15 in the vehicle width direction. A positioning antenna 61, an inertial measurement device 62, and a communication antenna 63 are provided inside the frame 16.

[0047] The positioning antenna 61 is capable of receiving radio waves from positioning satellites that constitute a satellite positioning system (GNSS). By performing known positioning calculations based on these radio waves, the position of the rice transplanter 1 can be obtained.

[0048] The inertial measurement device 62 has three gyroscope sensors (angular velocity sensors) and three accelerometer sensors. By using the angular velocity and acceleration of the rice transplanter 1 detected by the inertial measurement device 62 as an auxiliary means, the accuracy of the positioning results of the rice transplanter 1 is improved.

[0049] Communication antenna 63 is used for communication with Figure 3 The wireless communication terminal 7 shown has an antenna for wireless communication. Additionally, the rice transplanter 1 is equipped with a mobile communication antenna (not shown) for communication using mobile phone lines and networks.

[0050] like Figure 3As shown, the control unit 50 includes an arithmetic unit (not shown), a storage unit, and an input / output unit. Various programs and data are stored in the storage unit. The arithmetic unit can read from the storage unit and execute various programs. Through the cooperation of the aforementioned hardware and software, the control unit 50 can operate as a forward control unit 51, a reverse control unit 52, a turning control unit 53, and a work machine control unit 54. The control unit 50 can be a single piece of hardware or multiple pieces of hardware capable of communicating with each other. Furthermore, in addition to the aforementioned inertial measurement device 62, the control unit 50 is also connected to a position acquisition unit 64, a communication processing unit 65, a vehicle speed sensor 66, a steering angle sensor 67, and a clutch engagement sensor 68.

[0051] The position acquisition unit 64 is electrically connected to the positioning antenna 61. The position acquisition unit 64 acquires the position of the rice transplanter 1 based on the positioning signal received by the positioning antenna 61, such as latitude and longitude information. The position acquisition unit 64 performs positioning using the known GNSS-RTK method after receiving a positioning signal from a reference station (not shown) through an appropriate method. However, it can also be replaced by positioning using differential GNSS, single-point positioning, etc. Alternatively, position acquisition based on radio wave intensity such as wireless LAN, or position acquisition based on inertial navigation, etc., can also be performed.

[0052] The communication processing unit 65 is electrically connected to the communication antenna 63. The communication processing unit 65 is capable of performing modulation or demodulation processing in an appropriate manner to transmit and receive data with the wireless communication terminal 7.

[0053] The vehicle speed sensor 66 can detect the speed of the rice transplanter 1. The vehicle speed sensor 66 is set at an appropriate position on the rice transplanter 1, such as the axle of the front wheel 12. In this case, the vehicle speed sensor 66 generates pulses corresponding to the rotation of the axle of the front wheel 12. The detection result data obtained by the vehicle speed sensor 66 is output to the control unit 50.

[0054] The steering angle sensor 67 can detect the steering angle of the front wheel 12. The steering angle sensor 67 is installed at an appropriate location on the rice transplanter 1, for example, on the kingpin (not shown) of the front wheel 12. Alternatively, the steering angle sensor 67 can also be installed on the steering wheel 26. The detection data obtained by the steering angle sensor 67 is output to the control unit 50.

[0055] The insertion clutch sensor 68 is a sensor that detects the position of the insertion clutch lever 29. The detection result of the insertion clutch sensor 68 is output to the control unit 50. The control unit 50 can determine whether an insertion operation is in progress based on the detection result of the insertion clutch sensor 68. The data of the detection result obtained by the insertion clutch sensor 68 is output to the control unit 50. In addition, the insertion clutch sensor 68 can also determine whether an insertion operation is in progress based on the state of other components (e.g., whether the PTO shaft 24 located downstream of the insertion clutch is rotating) instead of the insertion clutch lever 29.

[0056] The forward control unit 51, the reverse control unit 52, and the turning control unit 53 are capable of performing controls related to the movement of the rice transplanter 1 (e.g., speed control and steering control). The forward control unit 51 performs controls related to the forward movement of the rice transplanter 1. The reverse control unit 52 performs controls related to the backward movement of the rice transplanter 1. The turning control unit 53 performs controls related to the turning of the rice transplanter 1. In the following description, the forward control unit 51, the reverse control unit 52, and the turning control unit 53 are sometimes collectively referred to as the "movement control unit." The movement control unit performs controls related to the autonomous movement of the rice transplanter 1. Furthermore, the movement control unit can also control the movement of the rice transplanter 1 according to the operator's commands. Moreover, the movement control unit can, for example, perform autonomous steering and change the speed according to the operator's commands.

[0057] When the vehicle speed is changed autonomously, the driving control unit controls the current vehicle speed, which is obtained based on the detection result of the vehicle speed sensor 66, to approach the target vehicle speed. This control is achieved by changing at least one of the gear ratio of the transmission device in the gearbox 23 and the rotational speed of the engine 22. In addition, the vehicle speed control also includes control to bring the vehicle speed to zero so as to stop the rice transplanter 1.

[0058] When steering is performed autonomously, the driving control unit controls the current steering angle, obtained from the detection result of the steering angle sensor 67, to approach the target steering angle. This control is achieved, for example, by driving a steering actuator mounted on the rotation axis of the steering wheel 26. Furthermore, regarding steering control, the driving control unit can also directly adjust the steering angle of the front wheels 12 of the rice transplanter 1, instead of the rotation angle of the steering wheel 26.

[0059] The machine control unit 54 can control the operation of the planting unit 14 (lifting or planting operation, etc.) based on predetermined conditions.

[0060] The wireless communication terminal 7 is a tablet terminal, comprising a communication antenna 71, a communication processing unit 72, a display unit 73, an operation unit 74, and a control unit 80. Furthermore, the wireless communication terminal 7 is not limited to a tablet terminal; it could also be a smartphone or a laptop. The wireless communication terminal 7 performs various processes related to the autonomous movement of the rice transplanter 1 as described later, but the control unit 50 of the rice transplanter 1 can also perform at least some of these processes. Conversely, the wireless communication terminal 7 can also perform at least some of the various processes related to autonomous movement performed by the control unit 50 of the rice transplanter 1.

[0061] The communication antenna 71 is a short-range communication antenna used for wireless communication with the rice transplanter 1. The communication processing unit 72 is electrically connected to the communication antenna 71. The communication processing unit 72 can perform modulation or demodulation processing in an appropriate manner to transmit and receive data with the rice transplanter 1. As described above, the rice transplanter 1 can be connected to a mobile phone line, therefore the wireless communication terminal 7 can be connected to the mobile phone line via the rice transplanter 1. Therefore, for example, a portion of the information stored in the control unit 50 or control unit 80 can be stored on an external server. Furthermore, the mobile communication antenna can be provided on the wireless communication terminal 7 instead of the rice transplanter 1.

[0062] The display unit 73 is a liquid crystal display or an organic EL display, etc., configured to display images. The display unit 73 can display, for example, information related to autonomous driving, information related to the settings of the rice transplanter 1, detection results from various sensors, and warning messages. The operation unit 74 includes a touch panel and hardware keys. The touch panel is overlapped with the display unit 73 and can detect operations based on the operator's fingers, etc. The hardware keys are located on the side of the frame of the wireless communication terminal 7 or around the display unit 73, etc., and can be operated by the operator by pressing them. Alternatively, the wireless communication terminal 7 may also have only one of the touch panel and hardware keys.

[0063] The control unit 80 includes an arithmetic unit (not shown), a storage unit, and an input / output unit. The storage unit stores various programs and data. The arithmetic unit can read and execute various programs from the storage unit. Through the cooperation of the aforementioned hardware and software, the control unit 80 can operate as both a storage unit 81 and a path generation unit 82. The processing performed by each part of the control unit 80 will be described later.

[0064] Next, refer to Figure 4This section describes the field and the driving path generated within it. The field includes a work area and a field edge area. The work area is located in the center of the field and is used for performing tasks. The field edge area is located outside the work area and is used to properly perform tasks within the work area. For example, the field edge area is used to move a rice transplanter 1 entering the field to the starting position of the work area. Furthermore, the field edge area is also used for turning the rice transplanter 1. Alternatively, a driving path can be generated without distinguishing between the work area and the field edge area.

[0065] In this embodiment, a travel path for enabling the rice transplanter 1 to move autonomously is pre-generated. Figure 4 The driving path 91 is shown. Driving path 91 is generated by the path generation unit 82. (As shown...) Figure 4 As shown, the driving path 91 is composed of multiple straight paths 91a. The driving path 91 is a path designed for autonomous driving only in straight sections. Furthermore, in this embodiment, turns are made at positions corresponding to the operator's actions, as described later, so turning paths are not pre-generated. However, the path generation unit 82 may pre-generate turning paths. In this case, the driving path includes straight paths and turning paths connecting the straight paths to each other.

[0066] The straight path 91a is a straight path, for example, parallel to one side (e.g., the shorter side) of the outline of the field or work area. The length of the straight path 91a is not particularly limited. For example, the path generation unit 82 can generate a straight path 91a that is contained within the aforementioned work area, or it can generate a straight path 91a that extends outside the work area or outside the field. The arrangement interval of the straight paths 91a is determined, for example, based on the work width, the overlap length (indicating the length by which adjacent work areas are repeated in the vehicle width direction), and the work interval (indicating the length by which adjacent work areas are separated in the vehicle width direction).

[0067] Next, refer to Figures 5-7 The process of turning the rice transplanter 1 near the edge of the field (field ridge) in this embodiment will be described. Furthermore, the flowcharts shown in the first and second embodiments are examples; the order of processing can be changed, and multiple processes can be performed in parallel. Additionally, some processes can be omitted, and others can be added.

[0068] As described above, in Patent Document 1, in order to enable the turning of the work vehicle to autonomously begin at a predetermined turning start position, and to ensure that the work vehicle turns reliably and appropriately, a position with a margin is set as the turning start position. As a result, the area in the field where the work vehicle operates along a straight path becomes narrower. Therefore, when not operating in the field edge area, the area that can be operated becomes smaller, and the field cannot be used effectively. In addition, even when operating in the field edge area, the field edge area widens, thereby increasing, for example, the number of times the field edge area is circled. Considering the above, in this embodiment, by operating until near the edge of the field and turning near the edge of the field, the range of operation of the rice transplanter 1 along a straight path can be expanded. As a result, for example, the number of times the field edge area is circled can be reduced (for example, from 2 times to 1 time). The specific processing will be described below.

[0069] After the operator stops the rice transplanter 1 at a predetermined position on the straight path 91a, for example, a predetermined operation is performed on the wireless communication terminal 7. As a result, the forward control unit 51 begins autonomous driving of the rice transplanter 1 along the straight path 91a (S101). Figure 6 (The forward movement). During the forward movement, steering is performed autonomously while the work based on the insertion unit 14 is carried out. In addition, during the forward movement, the vehicle speed can be changed autonomously or by operating the shift pedal 27 with the help of the operator (specifically, by operating the shift pedal 27). Alternatively, a shift lever can be provided instead of the shift pedal 27, and the vehicle speed can be changed by the operator operating the shift lever.

[0070] The rice transplanter 1 autonomously travels along a straight path 91a, moving towards the edge of the field. When the transplanter 1 reaches near the edge of the field, the operator performs a stopping operation (e.g., removing their foot from the gear shift pedal 27), bringing the transplanter 1 to a stop. Furthermore, in... Figure 6Although the forward movement is described as "stop: operator operation," this indicates that stopping the rice transplanter 1 near the edge of the field is not autonomous but an operator's action (in other words, the operator decides when to stop). Therefore, stopping in other situations (e.g., an abnormal situation) can be performed autonomously. By making the stopping operation of the rice transplanter 1 near the edge of the field an operator's action, the rice transplanter 1 can be brought closer to the edge of the field compared to stopping the rice transplanter 1 autonomously. As a result, the area for operation along the straight path 91a can be expanded. In addition, the operator performs the operation to stop the operation before and after stopping the rice transplanter 1, that is, the operation to switch the position of the planting clutch lever 29. Furthermore, the planting clutch can be switched from the transmission state to the cut-off state without the operator's operation on the planting clutch lever 29. Specifically, when the control unit 50 detects that the rice transplanter 1 has stopped or has switched from forward to reverse, it switches the planting clutch from the transmission state to the cut-off state. For example, it can detect whether the rice transplanter 1 has stopped or switched from forward to reverse based on the detection value of the vehicle speed sensor 66 or the position of the main gear lever 28.

[0071] Next, the operator performs a reverse operation to move the rice transplanter 1 backward, that is, by pressing the shift pedal 27 of the main gear lever 28 to the "reverse" position. When the reverse control unit 52 detects that the operator has performed a reverse operation (S102), it moves the rice transplanter 1 backward (S103, reverse operation). No operations based on the planting unit 14 are performed during the reverse operation. Furthermore, steering can be performed autonomously or by the operator during the reverse operation. Additionally, the speed can be changed autonomously or by the operator during the reverse operation. Figure 6 The "Stop: Operator Operation" entry for the reversing process has the same meaning as the entry for the advancing process.

[0072] After the operator reverses the rice transplanter 1 to a position where it can turn without touching the edge of the field, they perform the aforementioned stopping operation to bring the rice transplanter 1 to a stop. Furthermore, as described later, the operator can also autonomously stop the rice transplanter 1 during the reversing process. Next, the operator performs a forward operation to move the rice transplanter 1 forward, that is, by pressing the shift pedal 27 on the main gear lever 28 when it is in the "forward" position. When the turning control unit 53 detects that the operator has performed a forward operation (S104), it moves the rice transplanter 1 forward while autonomously turning (S105, turning operation). At this time, in this embodiment, turning based on autonomous driving begins without any operator intervention in the wireless communication terminal 7. Therefore, the need for operator instructions is reduced.

[0073] To explain in more detail, the turning control unit 53 initiates a turn based on autonomous driving when several conditions (turning start conditions) are met. One of the turning start conditions is that the operator has performed a forward operation. Other conditions may include, for example, the rice transplanter 1 being close to the edge of the field, or the rice transplanter 1 stopping after reversing. By adding these conditions, it is possible to prevent the rice transplanter 1 from turning in the center of the field. Furthermore, it is possible to determine whether the rice transplanter 1 is near the edge of the field by comparing the position of the rice transplanter 1 with the position of the field.

[0074] During the turning process, no operation based on the insertion part 14 is performed. Furthermore, during the turning process, steering is performed autonomously. Additionally, during the turning process, the vehicle speed can be changed either autonomously or by operator intervention.

[0075] In this embodiment, the rice transplanter 1 autonomously turns to the next pre-designated straight path 91a as follows. Furthermore, whether the rice transplanter 1 turns to reach the adjacent straight path 91a or to reach a further separated straight path 91a is predetermined.

[0076] In this embodiment, the turning control unit 53 first turns until the orientation of the rice transplanter 1 reaches a predetermined angle. Figure 6 In the example shown, the rice transplanter 1 is turned until its orientation is perpendicular to the straight path 91a (in other words, the rice transplanter 1 turns 90°). Next, the turning control unit 53 causes the rice transplanter 1 to autonomously travel towards the next straight path 91a (specifically, point 1 on the straight path 91a). Thus, the rice transplanter 1 can turn to the next straight path 91a.

[0077] Alternatively, the rice transplanter 1 can be turned to the next straight path 91a by other methods. Specifically, such as... Figure 7 As shown, a first turning path 91b is generated during the pre-defined path generation. This first turning path 91b is generated at a position with a margin to allow the rice transplanter 1 to turn reliably and appropriately. Therefore, in step S105, the turning control unit 53 sets a second turning path 91c that moves the first turning path 91b based on the current position of the rice transplanter 1. Typically, the second turning path 91c is closer to the edge of the field than the first turning path 91b. Therefore, the turning control unit 53 enables the rice transplanter 1 to autonomously travel along this second turning path 91c. This allows the rice transplanter 1 to turn onto the next straight path 91a.

[0078] Upon reaching the next straight path 91a, the forward control unit 51 again enables the rice transplanter 1 to autonomously travel along the straight path 91a (S101, forward operation). This process is repeated until the rice transplanter 1 reaches its destination. By turning the rice transplanter 1 using the method of this embodiment, the rice transplanter 1 can operate near the edge of the field, thus expanding the area that can be operated along the straight path. As a result, for example, the number of times the transplanter circumnavigates the field edge area can be reduced (e.g., from 2 times to 1 time).

[0079] Next, refer to Figures 8-10 The autonomous driving system 100 of the second embodiment will be described. In the description of the second embodiment, components that are the same as or similar to those in the first embodiment described above are sometimes marked with the same reference numerals in the drawings, and the description is omitted.

[0080] like Figure 8 As shown, the control unit 80 of the second embodiment can operate as a calculation unit 83 and a reporting unit 84 through the cooperation of the hardware and software described above.

[0081] exist Figure 9 The diagram shows the processing related to autonomous driving (especially turning near the edge of a field) performed by the autonomous driving system 100 of the second embodiment. Figure 9 Steps S201, S203, and S204 in the flowchart shown are related to Figure 5 Steps S101, S102, and S103 are the same, so their description is omitted. However, in the second embodiment, the calculation unit 83 performs a first distance measurement (S202) during the forward movement. The first distance is a length that serves as an indicator of how close the rice transplanter 1 is to the edge of the field. Specifically, the distance traveled by the rice transplanter 1 during the period when the measurement conditions are met is the first distance. Furthermore, the first distance is... Figure 10 It is shown as L1 in the diagram.

[0082] The period during which the measurement conditions are met refers to the period from when the measurement start condition is met to when the measurement end condition is met. Examples of measurement start conditions include the distance from the rice transplanter 1 to the edge of the field falling below a threshold, or an operator switching from autonomous to manual driving. Examples of measurement end conditions include the rice transplanter 1 stopping, the rice transplanter 1 reversing, an operation switching the planting clutch lever 29 from the working position to the non-working position, and the planting section 14 rising. Furthermore, it is possible to set which of these measurement start and end conditions to apply.

[0083] After calculating the distance traveled by the rice transplanter during the period when the measurement conditions are met, i.e., the first distance, the calculation unit 83 also calculates the reporting distance (S102). The reporting distance refers to the distance used in the reversing process to report to the operator that the starting position of the turn is close. For example, by using the first distance and the position of the field, it is possible to determine how close the rice transplanter 1 is to the edge of the field without touching it. In addition, the amount of space required in front of the rice transplanter 1 when turning can be determined based on information related to the body of the rice transplanter 1. Therefore, by using the first distance, the minimum distance required to turn the rice transplanter 1 close to the edge of the field without touching it can be determined. Furthermore, the minimum distance can be used as the reporting distance, or a value that is slightly increased or decreased from the minimum distance can be used as the reporting distance.

[0084] During the reversing process, the reporting unit 84 determines whether the distance from the edge of the field to the rice transplanter 1 is greater than or equal to the reporting distance (S205). If it is greater than or equal to the reporting distance, it reports to the operator that the turning start position is near (S206). Furthermore, there are various methods for reporting to the operator, such as generating a warning sound or displaying a warning on the display unit 73. Thus, the operator can be notified of the appropriate time to stop the rice transplanter 1 (in other words, the appropriate turning start position).

[0085] Furthermore, in the first embodiment, the operator's action is a prerequisite for stopping the reversing process. In contrast, in the second embodiment, distance-related information such as minimum distance and reported distance is obtained. Therefore, the rice transplanter 1 can also be stopped autonomously by means of the control unit 50. Additionally, in both the first and second embodiments, the switch from the forward to the reverse process is performed by the operator positioning the main gear lever 28 in the "reverse" position. In contrast, after the rice transplanter 1 stops, a predetermined actuator can be used to automatically switch the rice transplanter 1 to the reverse state and begin the reversing process.

[0086] Furthermore, even in the second embodiment, similar to the first embodiment, the operator's forward movement is one of the turning start conditions (S207). However, in the second embodiment, a distance condition related to the distance to the edge of the field is also set as one of the turning start conditions. The distance condition refers to the condition related to the distance required to turn the rice transplanter 1 without contacting the edge of the field. Therefore, the distance condition is, for example, that the current distance from the rice transplanter 1 to the edge of the field is greater than the minimum distance mentioned above. In addition, some margin is required, so the distance condition can also be set by slightly increasing the value of the minimum distance. After the operator's forward movement, the reporting unit 84 determines whether the distance condition is met (S208). If the distance condition is not met, it reports to the operator that it is difficult to turn (S209). In the case of difficulty in turning, the control unit 50 stops the rice transplanter 1 (S210). In this case, the operator moves the rice transplanter 1 back to a position where it can turn, and then turns the rice transplanter 1. In addition, after the rice transplanter 1 has moved back, the processing after step S207 can be performed again. Thus, in the second embodiment, by performing processing related to distance conditions, even when the reverse distance of the rice transplanter 1 is insufficient, the situation of forced turning and autonomous operation can be prevented.

[0087] Furthermore, since the distance condition is met, it is equivalent to meeting the turning start condition. Therefore, the turning control unit 53 causes the rice transplanter 1 to turn autonomously to the next straight path 91a (S211).

[0088] Furthermore, only a portion of the features of the second embodiment may be applied to the first embodiment. For example, if the distance conditions for initiating autonomous driving are predetermined and it is not necessary to measure the first distance, only features such as including the distance condition in the turning start conditions may be applied to the first embodiment.

[0089] As explained above, the autonomous driving system 100 of the above embodiment includes a path generation unit 82, a forward control unit 51, a reverse control unit 52, and a turning control unit 53. The path generation unit 82 generates multiple straight paths 91a arranged side by side in the field. The forward control unit 51, while enabling the rice transplanter 1 to perform operations, at least autonomously performs steering maneuvers to make the rice transplanter 1 travel along the straight paths 91a. After the operator stops the rice transplanter 1, which is traveling towards the edge of the field, the reverse control unit 52 does not enable the rice transplanter 1 to perform operations, but reverses the rice transplanter 1 according to the operator's operation or autonomously. If the rice transplanter 1, which is reversing with the aid of the reverse control unit 52, is stopped by the operator or autonomously, and there is a forward instruction based on the operator, the turning control unit 53 does not enable the rice transplanter 1 to perform operations, but at least autonomously performs steering maneuvers to make the rice transplanter 1 turn towards a pre-specified straight path.

[0090] Therefore, by having the operator stop the rice transplanter 1 near the edge of the field, operations can continue until the transplanter 1 stops relatively autonomously near the edge of the field. As a result, the area where the rice transplanter 1 can operate along a straight path can be expanded. In addition, by making the forward instruction from the operator one of the conditions for starting a turn, the operator's instructions can be simplified, and turns can be started at an earlier time.

[0091] In addition, in the autonomous driving system 100 of the above embodiment, the turning control unit 53 sets a turning path (second turning path 91c) that is connected to the pre-specified straight path 91a, and causes the rice transplanter 1 to turn along the second turning path 91c.

[0092] Therefore, by setting the second turning path 91c, the rice transplanter 1 can more reliably turn to the straight path 91a.

[0093] Furthermore, in the autonomous driving system 100 of the above embodiment, the reversing control unit 52 does not cause the rice transplanter 1 to perform operations, but at least autonomously performs steering operations to cause the rice transplanter 1 to reverse along the straight path 91a.

[0094] Therefore, since the rice transplanter 1 passes through approximately the same position when moving forward and backward, it is possible to prevent the generation of travel tracks in unnecessary locations.

[0095] Furthermore, the autonomous driving system 100 of the second embodiment includes a calculation unit 83 and a reporting unit 84. The calculation unit 83 calculates the distance traveled by the rice transplanter 1 during the period when the measurement conditions are met, i.e., a first distance, while the rice transplanter 1 is moving towards the edge of the field. The reporting unit 84 reports information related to the stopping position of the rice transplanter 1 to the operator based on the first distance while the rice transplanter 1 is reversing using the reversing control unit 52.

[0096] Therefore, when the operator stops the rice transplanter 1 while it is reversing, the operator can be notified of the position where the rice transplanter 1 should be stopped.

[0097] Furthermore, in the autonomous driving system 100 of the second embodiment, the calculation unit 83 calculates a condition related to the distance from the rice transplanter 1 to the edge of the field, i.e., a distance condition, based on the first distance. The distance condition is also included as a condition for the turning control unit 53 to start turning the rice transplanter 1.

[0098] Thus, for example, one can avoid starting a turn when too close to the edge of a field, thereby preventing forced turns from occurring.

[0099] The preferred embodiments of the present invention have been described above, but the above structure can be modified, for example, as follows.

[0100] In the above embodiment, the forward movement automatically begins after the turning process is completed. However, the rice transplanter 1 can also be temporarily stopped after the turning process is completed. This allows the operator to replenish the pesticide placed on the field ridge to the pesticide tank at the rear of the rice transplanter 1. Furthermore, it is possible to set whether the rice transplanter 1 is temporarily stopped after the turning process. Additionally, the temporary stop of the rice transplanter 1 after the turning process can be set to occur only once per multiple occurrences (or only at a predetermined location).

[0101] Explanation of reference numerals in the attached figures

[0102] 1… Rice transplanter (operating vehicle); 51… Forward control unit; 52… Reverse control unit; 53… Turning control unit; 82… Path generation unit; 83… Calculation unit; 100… Autonomous driving system.

Claims

1. An autonomous driving system, characterized in that, have: Switch the control unit to switch the forward and reverse directions of the work vehicle; The reversing control unit reverses the work vehicle that is stopped at the edge of the field, provided that the reversing operation of the switching operation unit is present. as well as The turning control unit, after causing the work vehicle to stop autonomously while reversing using the reversing control unit, at least autonomously performs steering maneuvers to turn the work vehicle. After turning with the help of the turning control unit, the vehicle can move at least autonomously by steering.

2. The autonomous driving system according to claim 1, characterized in that, After the turning control unit causes the work vehicle, which is reversing with the aid of the reversing control unit, to stop autonomously, the work vehicle turns if there is a forward instruction based on the operator. During the reversing of the work vehicle using the reversing control unit, the work vehicle will not turn even if there is a forward instruction based on the operator.

3. An autonomous driving system, characterized in that, have: The reverse control unit reverses the work vehicle that has stopped at the edge of the field; and The turning control unit, after causing the work vehicle to stop autonomously while reversing using the reversing control unit, at least autonomously performs steering maneuvers to turn the work vehicle. The turning control unit does not turn the work vehicle during the reversing process of the work vehicle using the reversing control unit and before it comes to an autonomous stop, even if there is a forward instruction based on the operator. Instead, it turns the work vehicle at least after the work vehicle, which is reversing using the reversing control unit, comes to an autonomous stop, when conditions including the presence of the forward instruction based on the operator are met.

4. The autonomous driving system according to claim 3, characterized in that, It also has: The reporting department shall report when the turning of the work vehicle, which is operated by the turning control unit, becomes difficult.

5. The autonomous driving system according to claim 3 or 4, characterized in that, The reversing control unit reverses the work vehicle that is stopped at the edge of the field when conditions, including the presence of a reversing instruction based on the operator, are met.

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