Automated driving method, work vehicle, and automated driving system

Abstract

The present invention provides an automated driving method, a work vehicle, and an automated driving system that can perform appropriate automated driving based on an appropriate reference direction without being affected by the shift in positional information over time. [Solution] A tractor 1 that performs automatic straight-line driving based on a reference direction 103 set based on a first reference position 101 and a second reference position 102 is equipped with a reference information update unit 38 that updates the first reference position 101 and the second reference position 102 when performing automatic straight-line driving, and updates the reference direction 103 based on the updated first reference position 101 and second reference position 102.

Description

Technical Field

[0001] The present invention relates to an automatic driving method, a work vehicle, and an automatic driving system for a work vehicle that performs automatic driving based on a reference orientation set based on a first reference position and a second reference position.

Background Art

[0002] Conventionally, some work vehicles such as tractors and combines perform automatic driving (automatic straight driving) based on a linear reference orientation (reference line) connecting two predetermined points (a first reference position and a second reference position) in a field. Before performing automatic driving, the work vehicle sets the first reference position and the second reference position in the field during manual driving and acquires coordinates as position information of the first reference position and the second reference position.

[0003] For example, in the combine disclosed in Patent Document 1, the self-vehicle position of the combine is set as point A (the first reference position) in response to a selection operation of the point A setting button, and the self-vehicle position of the combine is set as point B (the second reference position) in response to a selection operation of the point B setting button. Further, in this combine, in response to a selection operation of the reference line determination button, the set points A and B are determined, and a reference line (reference orientation) of a straight line connecting points A and B is calculated. Then, this combine performs work by automatically driving straight along a work stroke parallel to the reference line composed of points A and B as automatic harvesting driving.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in work vehicles, position information is acquired using satellite positioning systems such as GNSS, but over time, the position information (coordinates) drifts, causing a discrepancy between the actual positions where the first and second reference positions are set and the stored (registered) position information of the first and second reference positions. In this case, the reference bearing used for automatic straight-line driving deviates from the reference bearing initially set. As a result, the driving path of automatic straight-line driving, which is performed according to the set reference bearing, may no longer be parallel to the initially set reference bearing or the actual work trajectory based on that reference bearing, or may not be at equal intervals.

[0006] The present invention aims to provide an automated driving method, a work vehicle, and an automated driving system that can perform appropriate automated driving based on an appropriate reference direction without being affected by the shift in positional information over time. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides an automatic driving method for a work vehicle that performs automatic driving based on a reference direction set based on a first reference position and a second reference position, characterized in that it includes an update step in which the first reference position and the second reference position are updated when performing the automatic driving, and the reference direction is updated based on the updated first reference position and the second reference position.

[0008] Furthermore, in order to solve the above problems, the present invention provides a work vehicle that automatically drives based on a reference direction set based on a first reference position and a second reference position, and is characterized by comprising a reference information update unit that updates the first reference position and the second reference position when performing the automatic driving, and updates the reference direction based on the updated first reference position and the second reference position.

[0009] Furthermore, in order to solve the above problems, the present invention provides an automatic driving system for a work vehicle that performs automatic driving based on a reference direction set based on a first reference position and a second reference position, characterized in that it includes a reference information update unit that updates the first reference position and the second reference position when performing the automatic driving, and updates the reference direction based on the updated first reference position and the second reference position. [Effects of the Invention]

[0010] The present invention provides an automated driving method, a work vehicle, and an automated driving system that can perform appropriate automated driving based on an appropriate reference direction without being affected by the shift in positional information over time. [Brief explanation of the drawing]

[0011] [Figure 1] This is a side view showing an example of a tractor according to an embodiment of the present invention. [Figure 2] This is a block diagram of a tractor according to an embodiment of the present invention. [Figure 3] This is a plan view showing an example of a field in which a tractor according to an embodiment of the present invention operates. [Figure 4] This is a plan view showing an example of a field in which a tractor according to an embodiment of the present invention operates. [Figure 5] This is a plan view showing an example of a field in which a tractor according to an embodiment of the present invention operates. [Figure 6] This flowchart shows an example of automatic straight-line driving operation in a tractor according to an embodiment of the present invention. [Modes for carrying out the invention]

[0012] The work vehicle of the present invention performs work by driving on a field while operating an implement, either automatically or manually. As an example of a work vehicle according to the embodiment of the present invention, a tractor 1 will be described with reference to Figure 1, etc. As shown in Figure 1, the tractor 1 comprises a body 2 and an implement 3, and is configured to perform work such as tilling with the implement 3 while driving on the body 2. Various implements 3 such as rotary tillers, harrows, loaders, plows, and box scrapers are attached to the body 2 of the tractor 1 as needed. Furthermore, as shown in Figure 2, the tractor 1 is equipped with a control device 4 that controls the operation of each part.

[0013] Tractor 1 is set to either manual driving mode or automatic driving mode. When manual driving mode is set, tractor 1 is driven manually within the field in response to the operator's operation of various controls (steering wheel, accelerator pedal, shift lever, etc.).

[0014] When the automatic driving mode is set, the tractor 1 sets a first reference position 101 and a second reference position 102 relative to the field 100 as basic information for automatic straight driving, as shown in Figure 3, in order to perform automatic straight driving (automatic straight driving). Based on the set first reference position 101 and second reference position 102 as basic information for automatic straight driving, the tractor 1 sets a reference direction 103 and performs automatic straight driving based on the set reference direction 103.

[0015] At this time, the tractor 1 is controlled by the control device 4 to automatically travel in a straight line parallel to a predetermined straight reference direction 103 (reference line) set in the field 100, controlling the vehicle speed and steering, etc. Alternatively, the tractor 1 may create a travel path 104 parallel to the set reference direction 103 at predetermined intervals and automatically travel in a straight line according to the travel path 104. In Figure 3, the reference direction 103 is shown as a dashed line, the travel path 104 created based on the reference direction 103 is shown as a dashed line, and the travel trajectory of the tractor 1 is shown as a solid line with an arrow indicating the direction of travel.

[0016] For example, the predetermined interval is calculated by multiplying the working width of the tractor 1 by the number of travel routes (number of straight travel routes) from the reference orientation 103. Specifically, in the case of the travel route 104 adjacent to the reference orientation 103, since the number of travel routes is 1, the tractor 1 performs automatic straight travel along the travel route 104 at an interval of the working width from the reference orientation 103. Alternatively, the tractor 1 may perform automatic straight travel while adjusting its vehicle position so as to leave a predetermined interval from the set reference orientation 103.

[0017] Alternatively, when the automatic driving mode is set, instead of automatic straight travel, the tractor 1 may perform automatic driving such as reciprocating travel that reciprocates along a plurality of straight routes in the field 100 or circular travel that repeatedly circles around the straight route while shifting from the center side to the outer side of the field 100 under the control of the control device 4.

[0018] A pair of left and right front wheels 10 are provided on the lower front side of the vehicle body 2, and a pair of left and right rear wheels 11 are provided on the lower rear side of the vehicle body 2. A cabin 12 for an operator to board is provided on the upper part of the vehicle body 2, and a driver's seat and various operating tools (steering wheel, accelerator pedal, shift lever, etc.) are provided inside the cabin 12.

[0019] In particular, in this embodiment, as operating tools for performing the operation of automatic straight travel, the tractor 1 includes, as shown in FIG. 2, at least a first reference position operation unit 41 for operating the setting of the first reference position 101 and a second reference position operation unit 42 for operating the setting of the second reference position 102. The first reference position operation unit 41 and the second reference position operation unit 42 may be attached near the driver's seat so that an operator sitting on the driver's seat can operate them, or may be provided in an external device such as a portable terminal 5 owned by the operator.

[0020] The first reference position operation unit 41 transmits an instruction to set the first reference position 101 to the control device 4 according to a setting operation such as a pressing operation. In the control device 4, the vehicle position of the tractor 1 is set as the first reference position 101. The second reference position operation unit 42 transmits an instruction to set the second reference position 102 to the control device 4 according to a setting operation such as a pressing operation. In the control device 4, the vehicle position of the tractor 1 is set as the second reference position 102.

[0021] Also, as shown in FIG. 2, the tractor 1 includes an offset button 43 in order to shift (translate in parallel) by the amount of the offset value during automatic straight running. The offset button 43 may be attached near the driver's seat so that, for example, an operator sitting on the driver's seat can operate it, or may be provided in an external device such as a portable terminal 5 held by the operator.

[0022] Also, the vehicle body 2 is provided with a power unit 13, a working machine lifting mechanism 14, a positioning unit 15 (see FIG. 2), and a control device 4.

[0023] The power unit 13 includes an engine 16 and a transmission 17. The power of the engine 16 is transmitted to each front wheel 10 and each rear wheel after being shifted by the transmission 17. A pair of left and right lower links 18, a top link 19, and a PTO shaft 20 are connected to the rear part of the transmission 17. The working machine 3 is connected to the rear ends of the lower links 18, the top link 19, and the PTO shaft 20 and is driven by the PTO shaft 20.

[0024] The working machine lifting mechanism 14 includes a pair of left and right lift arms 21 and a lift cylinder 22 composed of a hydraulic cylinder. The tip of one lift arm is connected to one lower link 18 via a link member 23, and the tip of the other lift arm is connected to the other lower link 18 via a rolling cylinder 24. The working machine lifting mechanism 14 can change the height of the working machine 3 supported by the vehicle body 2 by driving the lift cylinder 22.

[0025] The implement 3 is, for example, a rotary tiller and includes a tilling cover 25 that extends in the left-right direction. A tilling rotary shaft 26, which has a rotating shaft that extends in the left-right direction, is rotatably mounted on the tilling cover 25, and the tilling rotary shaft 26 rotates by power transmitted from the PTO shaft 20. In addition, multiple tilling tines 27 are provided on the tilling rotary shaft 26 at intervals in the left-right direction. The implement 3 is configured so that the tilling tines 27, together with the tilling rotary shaft 26, rotate and till the soil of the field 100.

[0026] The positioning unit 15 is configured to acquire the position information (positioning point) of the tractor 1 using a satellite positioning system such as GNSS. It receives positioning signals from positioning satellites via a positioning antenna and acquires the position information of the positioning unit 15, i.e., the position information of the tractor 1, based on the positioning signals.

[0027] Next, the control unit 4 will be described. The control unit 4 is composed of a computer such as a CPU and, as shown in Figure 2, is connected to a storage unit 31 such as ROM, RAM, hard disk drive, and flash memory, and a communication unit 32 that communicates with external devices.

[0028] The memory unit 31 stores programs and data for controlling various components and functions of the tractor 1, and the control device 4 controls the various components and functions by performing calculations based on the programs and data stored in the memory unit 31. For example, the control device 4 controls the positioning unit 15 to obtain the position of the tractor 1.

[0029] The storage unit 31 stores field information of the field 100, which is the target of the tractor 1's work. This field information includes, for example, the shape, size, and position information (coordinates, etc.) of the field edges that constitute the outer perimeter of the field, and the shape, size, and position information (coordinates, etc.) of the work area of ​​the field 100. The field information also includes information such as the shape, size, and position information (coordinates, etc.) of unworked areas where work has not yet been performed, and completed work areas where work has already been completed. In this embodiment, the storage unit 31 stores at least the position information of a first reference position 101 and a second reference position 102 set in the field 100, and the position information of a straight reference direction 103 (reference line) passing through the first reference position 101 and the second reference position 102, as information used for automatic straight-line driving.

[0030] The communication unit 32 can communicate wirelessly with external devices such as the mobile terminal 5 held by the worker via a wireless communication antenna. The control device 4 controls the communication unit 32 to communicate wirelessly with the mobile terminal 5 and transmits and receives various information between the two devices.

[0031] The mobile terminal 5 is one of the components of the tractor 1 and is a terminal that can remotely control the tractor 1. It consists of, for example, a tablet terminal equipped with a touch panel or a notebook-type personal computer.

[0032] Furthermore, the control device 4 operates as a reference information setting unit 35, a route creation unit 36, an automatic driving control unit 37, and a reference information update unit 38 by executing a program stored in the memory unit 31. The reference information setting unit 35, the route creation unit 36, the automatic driving control unit 37, and the reference information update unit 38 realize the reference information setting process, route creation process, automatic driving control process, and reference information update process of the automatic driving method according to the present invention.

[0033] The reference information setting unit 35 sets the basic information for automatic straight-line driving when the tractor 1 is manually driven in the field 100. Normally, in the manual driving process of the tractor 1, in which a reference direction 103 is set for automatic straight-line driving, a first reference position 101 is set at the start of straight-line driving and a second reference position 102 is set at the end of straight-line driving. The reference information setting unit 35 sets the first reference position 101 and the second reference position 102 within the field 100 according to the operator's operation.

[0034] For example, the reference information setting unit 35 acquires the position of the tractor 1 by the positioning unit 15 in response to the setting operation of the first reference position operation unit 41, and stores and sets it as the first reference position 101 in the storage unit 31. The reference information setting unit 35 acquires the position of the tractor 1 by the positioning unit 15 in response to the setting operation of the second reference position operation unit 42, and stores and sets it as the second reference position 102 in the storage unit 31.

[0035] Furthermore, after setting the first reference position 101, the reference information setting unit 35 may accept a setting operation from the second reference position operation unit 42 and enable the setting of the second reference position 102, using the condition that the tractor 1's own position is more than a predetermined distance away from the first reference position 101 as the setting condition for the second reference position 102.

[0036] Furthermore, upon completion of setting the second reference position 102, the reference information setting unit 35 creates a straight reference direction 103 (reference line) passing through the first reference position 101 and the second reference position 102 based on the set first reference position 101 and second reference position 102, and stores and sets it in the storage unit 31. In addition, after setting the second reference position 102, the reference information setting unit 35 may make it possible to set the reference direction 103 by setting the condition that the first reference position 101 and the second reference position 102 are separated by a predetermined distance or more.

[0037] The route creation unit 36 ​​creates a travel route 104 based on the reference direction 103 set by the reference information setting unit 35. For example, the route creation unit 36 ​​creates multiple travel routes 104 that are straight lines parallel to the reference direction 103 and are arranged at intervals for each working width from the reference direction 103. Alternatively, the route creation unit 36 ​​creates multiple travel routes 104 consisting of a straight line parallel to the reference direction 103 that passes through the position of the tractor 1 and multiple straight lines arranged at intervals for each working width from that straight line. Alternatively, the route creation unit 36 ​​may create a travel route 104 consisting only of a straight line parallel to the reference direction 103 that passes through the position of the tractor 1.

[0038] The automatic driving control unit 37 controls the power unit 13 and the implement 3 to control the speed and steering of the tractor 1 so that it automatically drives in a straight line parallel to a straight reference direction 103 set in the field 100. Alternatively, the automatic driving control unit 37 may control the automatic straight-line driving according to a driving path 104 created parallel to the set reference direction 103, or it may control the automatic straight-line driving by adjusting its own position to maintain a predetermined distance from the set reference direction 103. Below, an example in which the tractor 1 automatically drives in a straight line according to a driving path 104 parallel to the reference direction 103 will be described.

[0039] For example, when the tractor 1 meets the conditions for starting automatic straight-line driving, the automatic driving control unit 37, in response to the instruction to start automatic straight-line driving, acquires a driving path 104 based on the reference direction 103, and, based on the position information of the tractor 1 measured by the positioning unit 15, executes automatic straight-line driving so that the tractor 1 moves in a straight line along the driving path 104.

[0040] The automatic driving control unit 37 uses as start conditions, for example, that a first reference position 101 and a second reference position 102 and a reference direction 103 have been set, that a driving path 104 has been created based on the reference direction 103, and that the tractor 1 is located within a predetermined distance and direction from the driving path 104 (for example, a designated driving path 104 or the driving path 104 closest to the tractor 1).

[0041] Furthermore, in response to the operation of the offset button 43, the automatic driving control unit 37 performs an offset operation to move the tractor 1 diagonally from the driving trajectory in order to change the position of the machine in the left-right direction by shifting it by the amount of the set path offset target value.

[0042] The reference information update unit 38 updates the set first reference position 101 and second reference position 102 when the tractor 1 is performing automatic straight-line driving, and updates the set reference direction 103 based on the updated first reference position 101 and second reference position 102. In the tractor 1, after setting the first reference position 101 and second reference position 102 whose position information is acquired by the positioning unit 15, a shift (drift) in the position information (coordinates) may occur over time. In this case, as shown in Figure 4, the position information of the first reference position 101' and second reference position 102' stored (registered) will be different from the actual positions where the first reference position 101 and second reference position 102 were set, causing the reference direction 103' and driving path 104' to be shifted. To address such discrepancies in positional information, the reference information update unit 38 updates the original first reference position 101' and second reference position 102' to the first reference position 101 and second reference position 102 based on the actual driving trajectory, as shown in Figure 5, and also updates the reference direction 103. The route creation unit 36 ​​then creates a driving route 104 based on the updated reference direction 103.

[0043] The reference information update unit 38 acquires the position information of the first reference position 101 to be updated at the start of straight driving in automatic straight driving along the driving path 104 based on the reference direction 103, and acquires the position information of the first reference position 101 to be updated at the end of straight driving.

[0044] Specifically, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 in accordance with a predetermined update timing during automatic straight-line driving on the driving path 104 based on the reference direction 103, and also updates the reference direction 103 in accordance with the updates of the first reference position 101 and the second reference position 102.

[0045] The reference information update unit 38 sets the timing for updating the first reference position 101 as when the first action or operation of the tractor 1 is performed, and updates the first reference position 101 with the position information of the tractor 1 acquired when the first action or operation is performed. Here, the first action of the tractor 1 is, for example, the operation of lowering the implement 3 or the operation of starting automatic driving, and the first operation of the tractor 1 is, for example, the operation of lowering the implement 3 or the operation of starting automatic driving. If the implement 3 is linked to automatically lowering in conjunction with the operation of starting automatic driving, the timing for updating the first reference position 101 is set as the operation of starting automatic driving or the operation of lowering the implement 3.

[0046] Furthermore, the reference information update unit 38 sets the timing for updating the second reference position 102 as when the second action or operation of the tractor 1 is performed, and updates the second reference position 102 with the position information of the tractor 1 acquired when the second action or operation is performed. Here, the second action of the tractor 1 is, for example, the raising of the implement 3 or the termination of automatic driving, and the second operation of the tractor 1 is, for example, the raising of the implement 3 or the termination of automatic driving. If the implement 3 is linked to automatically raising in conjunction with the termination of automatic driving, the timing for updating the first reference position 101 is set to the termination of automatic driving or the raising of the implement.

[0047] Furthermore, when the tractor 1 is performing automatic straight-line driving, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 at predetermined intervals according to the update timing described above. Here, the reference information update unit 38 may acquire the position information of the first reference position 101 and the second reference position 102 as a process to update the driving path 104 that is currently being driven in an automatic straight line after the predetermined period has elapsed, or it may acquire the position information of the first reference position 101 and the second reference position 102 as a process to update the next driving path 104 after the driving path 104 that is currently being driven in an automatic straight line after the predetermined period has elapsed. In other words, the predetermined period is a condition for determining the timing of the driving path 104 (process) for which the position information of the first reference position 101 and the second reference position 102 is acquired for updating.

[0048] For example, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 each time automatic straight-line driving starts, as a predetermined period. At this time, the reference information update unit 38 considers the time when automatic straight-line driving starts on a driving path 104 adjacent to the reference direction 103 (the first path from the reference direction 103) to be the time when the predetermined period has elapsed, and updates the first reference position 101 and the second reference position 102 according to the update timing on the driving path 104. In other words, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 for each driving path 104.

[0049] Alternatively, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 each time it completes automatic driving on a predetermined number of travel routes 104 based on the reference direction 103 and starts automatic straight-line driving on the next travel route 104, which is set as a predetermined period. In this case, if the predetermined number is n (an integer), the reference information update unit 38 considers the time when automatic straight-line driving starts on the (n+1)th travel route 104 (step) from the reference direction 103 to be the time when the predetermined period has elapsed, and updates the first reference position 101 and the second reference position 102 according to the update timing on that travel route 104. The predetermined number may be a number set in advance, or a number set according to the operator's arbitrary operation. That is, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 for every (n+1) travel routes 104.

[0050] Alternatively, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 at intervals of a predetermined time elapsed since the previous setting of the first reference position 101 and the second reference position 102. At this time, the reference information update unit 38 may update the first reference position 101 and the second reference position 102 according to the update timing in the travel route 104 where automatic straight-line travel is being performed when the first predetermined time has elapsed, or it may update the first reference position 101 and the second reference position 102 according to the update timing in the next travel route 104 after the travel route 104 where automatic straight-line travel is being performed when the first predetermined time has elapsed.

[0051] Here, the previous setting of the first reference position 101 and the second reference position 102 includes the previous update of the first reference position 101 and the second reference position 102. Also, the previous setting (update) of the first reference position 101 and the second reference position 102 is when the setting (update) of the first reference position 101 and the second reference position 102 was completed last time, that is, when the setting (update) of the second reference position 102 was completed. Alternatively, the previous setting (update) of the reference bearing 103 may be used instead of the previous setting of the first reference position 101 and the second reference position 102. The first predetermined time may be a time set in advance based on the predicted time for the occurrence of a deviation (drift) in the position information (coordinates) measured by the positioning unit 15, or it may be a time set according to the operator's arbitrary operation.

[0052] Incidentally, if the first reference position 101 and the second reference position 102 have not been updated since their last setting, and the second predetermined time has elapsed beyond the first predetermined time, it can be inferred that the first action or operation to update the first reference position 101, or the second action or operation to update the second reference position 102, was not performed when the update occurred due to the elapsed first predetermined time. Furthermore, in this case, it can be inferred that the predicted time for the occurrence of a deviation (drift) in the position information (coordinates) measured by the positioning unit 15 has been exceeded. For example, this situation may occur if an operator temporarily interrupts work performed by automatic straight-line driving.

[0053] Therefore, when a second predetermined time, which is longer than the first predetermined time, has elapsed since the last setting of the first reference position 101 and the second reference position 102, the reference information update unit 38 provides notification prompting manual driving to update the first reference position 101 and the second reference position 102.

[0054] The reference information update unit 38 may provide notification prompting this update via a screen display on a display device 44 provided on the tractor 1, or via audio output from a speaker 45 provided on the tractor 1. Alternatively, the reference information update unit 38 may provide notification prompting this update via a screen display on a display device provided on a mobile terminal 5 that is communicatively connected to the tractor 1, or via audio output from a speaker provided on the mobile terminal 5. The second predetermined time may be a time set in advance based on the predicted time for the occurrence of a deviation (drift) in the position information (coordinates) measured by the positioning unit 15, or it may be a time set according to the operator's arbitrary operation. It is preferable that the difference between the second predetermined time and the first predetermined time be set to be equal to or greater than the travel time of one to two travel routes 104 based on the previously set reference bearing 103.

[0055] Furthermore, since the reference information update unit 38 can estimate that a discrepancy has occurred in the position information measured by the positioning unit 15 after the second predetermined time has elapsed, if the first reference position 101 and the second reference position 102 are not updated by manual driving, the automatic driving control unit 37 may prohibit the start of automatic straight driving.

[0056] Furthermore, when the tractor 1 is performing automatic straight-line driving, the reference information update unit 38 will update the first reference position 101 and the second reference position 102 if the predetermined permission conditions are met in addition to the predetermined period and update timing conditions described above. Here, the reference information update unit 38 may store the first position information acquired for the first reference position 101 and the second position information acquired for the second reference position 102, and update the first position information and the first position information as the first reference position 101 and the second reference position 102, respectively, if the permission conditions are met. In addition, if the reference information update unit 38 has passed a predetermined number of driving routes 104 without meeting the permission conditions, it may issue a notification prompting the updating of the first reference position 101 and the second reference position 102 by manual driving.

[0057] For example, when the reference information update unit 38 acquires position information for the first reference position 101 and the second reference position 102 that satisfy the update timing conditions described above, in a travel route 104 to be updated that satisfies the predetermined period conditions described above, it may set as an authorization condition that the distance between the first reference position 101 and the second reference position 102 is greater than or equal to a predetermined length.

[0058] As a prerequisite for such permission conditions, if the distance between the newly acquired first reference position 101 and the second reference position 102 is too short, the straight line passing through these two reference positions may not be parallel to the desired reference direction 103. Therefore, if the distance between the newly acquired first reference position 101 and the second reference position 102 is too short, the reference information update unit 38 will consider the calculation of the position of the first reference position 101 or the second reference position 102 and the reference direction 103 to be inappropriate, and will not update the first reference position 101 and the second reference position 102 or the reference direction 103. The predetermined length may be a length set in advance, or a length calculated from a predetermined ratio to the distance between the first reference position 101 and the second reference position 102 that was initially set, or a length set according to the operator's arbitrary operation.

[0059] Furthermore, the reference information update unit 38 may, when it acquires position information for the first reference position 101 and the second reference position 102 that satisfy the update timing conditions described above, in a travel route 104 to be updated that satisfies the predetermined period conditions described above, set as an permission condition that the travel trajectory from the first reference position 101 to the second reference position 102 is within a predetermined meander with respect to the straight line connecting the first reference position 101 and the second reference position 102, and is recognized as a straight line. Here, a predetermined meander includes being within the error range of the positioning accuracy with respect to the straight line connecting the first reference position 101 and the second reference position 102, and may also include being within a predetermined separation distance, or being oblique within a predetermined angle, etc.

[0060] As a prerequisite for these permission conditions, if the travel trajectory from the newly acquired first reference position 101 to the second reference position 102 is significantly meandering, the straight line passing through the first reference position 101 and the second reference position 102 may not be parallel to the desired reference direction 103. Therefore, if there is a significant meander in the travel route 104 to be updated that deviates significantly from the straight line connecting the first reference position 101 and the second reference position 102, the reference information update unit 38 will not update the first reference position 101 and the second reference position 102.

[0061] Furthermore, when the reference information update unit 38 acquires position information for the first reference position 101 and the second reference position 102 that satisfy the update timing conditions described above, in the travel route 104 to be updated that satisfies the predetermined period conditions described above, it may set as a permission condition that the vehicle has not made a temporary stop during the automatic straight-line travel from the first reference position 101 to the second reference position 102. Here, a temporary stop refers to a state in which the vehicle has stopped traveling with the work equipment 3 lowered.

[0062] As a prerequisite for these permission conditions, if the vehicle has temporarily stopped between the newly acquired first reference position 101 and the second reference position 102, a discrepancy may occur in the position information measured by the positioning unit 15. Therefore, if the vehicle has temporarily stopped between the first reference position 101 and the second reference position 102 in the travel route 104 to be updated, the reference information update unit 38 will not update the first reference position 101 and the second reference position 102.

[0063] Furthermore, the reference information update unit 38 may, when it acquires position information for the first reference position 101 and the second reference position 102 that satisfy the update timing conditions described above, in the travel route 104 to be updated that satisfies the predetermined period conditions described above, set as a permission condition that the lifting and lowering operations of the work equipment 3 have not been performed more than a predetermined number of times during the intermediate stages of automatic straight travel.

[0064] As a prerequisite for these permission conditions, if the raising and lowering operations of the work implement 3 are performed repeatedly, there is a possibility that travel and work will be performed that differs from the desired automatic straight-line travel according to the set reference direction 103. Therefore, if the raising and lowering operations of the work implement 3 are performed more than a predetermined number of times between the first reference position 101 at the start stage and the second reference position 102 at the end stage in the travel path 104 to be updated, the reference information update unit 38 will not update these first reference position 101 and second reference position 102. The reference information update unit 38 may count the combination of raising and lowering operations of the work implement 3 as one operation for each predetermined number of operations.

[0065] As described above, the raising of the implement 3 is the second action of the tractor 1, which is the timing for updating the second reference position 102, and the lowering of the implement 3 is the first action of the tractor 1, which is the timing for updating the first reference position 101. Therefore, in the automatic straight-line travel path 104, the reference information update unit 38 acquires the first reference position 101 at the start stage in response to the first action or operation of the tractor 1, and acquires the second reference position 102 at the end stage in response to the second action or operation of the tractor 1. On the other hand, if the raising and lowering of the implement 3 is performed at an intermediate stage, the unit will also acquire the second reference position 102 and the first reference position 101 at that intermediate stage.

[0066] In this case, if the raising and lowering operations of the work machine 3 at intermediate stages are within a predetermined number of times, the reference information update unit 38 may consider the raising and lowering operations of the work machine 3 at intermediate stages as the update timing for the second reference position 102 and the update timing for the first reference position 101, and set a plurality of reference lines connecting the first reference position 101 and the second reference position 102 in order, based on the first reference position 101 at the starting stage, the second reference position 102 and the first reference position 101 at intermediate stages, and the second reference position 102 at the ending stage, and set a linear reference direction 103 based on the plurality of reference lines.

[0067] Alternatively, the reference information update unit 38 may set a linear reference direction 103 using the first reference position 101 at the start stage and the second reference position 102 at the end stage, without considering the raising and lowering operations of the work machine 3 at intermediate stages as the update timing for the second reference position 102 and the update timing for the first reference position 101.

[0068] Furthermore, the reference information update unit 38 may, when it acquires position information for the first reference position 101 and the second reference position 102 that satisfy the update timing conditions described above, in the travel route 104 to be updated that satisfies the predetermined period conditions described above, set as a permission condition that no offset operation or offset movement is performed during the automatic straight-line travel from the first reference position 101 to the second reference position 102.

[0069] As a prerequisite for these permission conditions, if an offset operation is performed during automatic straight-line driving, there is a possibility that driving and work different from the desired automatic straight-line driving according to the set reference direction 103 may have occurred. Therefore, if an offset operation or offset movement is performed between the first reference position 101 and the second reference position 102 in the driving path 104 to be updated, the reference information update unit 38 will not update the first reference position 101 and the second reference position 102.

[0070] Furthermore, the reference information update unit 38 may update the first reference position 101 and the second reference position 102 if, in addition to the above-mentioned permission conditions, other permission conditions are met.

[0071] Furthermore, the reference information update unit 38 may allow the operator to select from the various permission conditions described above, and may update the first reference position 101 and the second reference position 102 when the selected permission conditions are met.

[0072] For example, in the above description, the reference information update unit 38 determined that the permission conditions were not met when an offset operation or offset movement was performed, and therefore did not update the first reference position 101 and the second reference position 102. However, even when an offset movement is performed during automatic straight-line driving, it is possible that the driving and work were performed within a predetermined error range relative to the desired automatic straight-line driving according to the set reference direction 103. Therefore, the reference information update unit 38 may update the first reference position 101 and the second reference position 102 when other permission conditions are met, without making the absence of an offset operation or offset movement a permission condition.

[0073] Next, an example of the automatic straight-line driving operation of the tractor 1 of this embodiment will be explained with reference to the flowchart in Figure 6. Note that the tractor 1 performs its work operations as needed in the field 100, but this will be omitted from the explanation below.

[0074] First, the operator manually drives the tractor 1 and operates the first reference position operation unit 41 and the second reference position operation unit 42, thereby causing the reference information setting unit 35 to set the first reference position 101 and the second reference position 102, and set the reference direction 103 based on these first reference position 101 and second reference position 102 (step S1).

[0075] Furthermore, the route creation unit 36 ​​creates multiple travel routes 104 that are straight lines parallel to the set reference direction 103 and are arranged with intervals of working width from the reference direction 103 (step S2).

[0076] Next, when the operator initiates the automatic straight-line driving start operation, the automatic driving control unit 37 controls the automatic straight-line driving according to the driving path 104 based on the reference direction 103 (step S3).

[0077] When the tractor 1 is performing automatic straight-line driving, if the first action or operation is performed (step S4: Yes), the reference information update unit 38 acquires the first position information.

[0078] When the tractor 1 is performing automatic straight-line driving, if a second action or operation is performed (step S5: Yes), the reference information update unit 38 acquires second position information.

[0079] If the first position information is not acquired (Step S4: No), or if the second position information is not acquired (Step S5: No), and the second predetermined time has elapsed (Step S6: Yes), the reference information update unit 38 will notify the user via the display device 44 and speaker 45 to update the first reference position 101 and the second reference position 102 by manual driving (Step S7). In this case, the user will return to Step S1 and restart the manual driving. The reference information update unit 38 will wait to acquire the first position information and the second position information until the second predetermined time has elapsed.

[0080] Furthermore, if the automatic straight-line driving operation on the driving path 104 is not moved to the next driving path 104 (Step S8: No), the automatic straight-line driving operation by tractor 1 is completed.

[0081] If the vehicle is to proceed to the next travel route 104 (Step S8: Yes), the reference information update unit 38 determines whether a predetermined period has elapsed (Step S9). If the predetermined period has not elapsed (Step S9: No), the vehicle returns to Step S3 without updating the first reference position 101 and the second reference position 102, and proceeds to automatic straight-line driving on the next travel route 104.

[0082] If a predetermined period has elapsed (Step S9: Yes), the reference information update unit 38 determines whether or not the permission conditions are met (Step S10). If the permission conditions are not met (Step S10: No), the first reference position 101 and the second reference position 102 are not updated, and the system returns to Step S3 to proceed to automatic straight-line driving on the next driving route 104.

[0083] If the permit conditions are met (Step S10: Yes), the reference information update unit 38 updates the first position information and the second position information as the first reference position 101 and the second reference position 102, respectively (Step S11). The reference information update unit 38 also updates the reference bearing 103 based on the updated first reference position 101 and the second reference position 102 (Step S12).

[0084] Then, returning to step S2, the route creation unit 36 ​​creates a driving route 104 based on the updated reference direction 103, and then, in step S3, in response to the automatic straight-line driving start operation, the automatic driving control unit 37 performs automatic straight-line driving according to the driving route 104 based on the updated reference direction 103.

[0085] As described above, according to this embodiment, the work vehicle is a tractor 1 that performs automatic straight-line driving (automatic driving) based on a reference direction 103 set based on a first reference position 101 and a second reference position 102, and includes a reference information update unit 38 that updates the first reference position 101 and the second reference position 102 when performing automatic straight-line driving, and updates the reference direction 103 based on the updated first reference position 101 and the second reference position 102.

[0086] In other words, in the present invention, an automatic driving method for a work vehicle such as a tractor 1 that performs automatic straight-line driving (automatic driving) based on a reference direction 103 set based on a first reference position 101 and a second reference position 102 includes an update step in which the first reference position 101 and the second reference position 102 are updated when performing automatic straight-line driving, and the reference direction 103 is updated based on the updated first reference position 101 and the second reference position 102.

[0087] In work vehicles such as tractor 1, after the positioning unit 15 sets the first reference position 101 and the second reference position 102, a shift (drift) in position information (coordinates) may occur over time. In contrast, according to the present invention, when tractor 1 performs automatic straight-line driving, it updates the first reference position 101 and the second reference position 102, as well as the reference direction 103. This suppresses the occurrence of automatic straight-line driving that is not parallel to the driving trajectory when the reference direction 103 was first set, or the actual driving trajectory of automatic straight-line driving based on the initially set reference direction 103, or automatic straight-line driving that is not at equal intervals. In this way, it is possible to provide an automatic driving method and automatic driving system for work vehicles that can perform appropriate automatic straight-line driving based on an appropriate reference direction 103 without being affected by the shift in position information over time.

[0088] Furthermore, according to the tractor 1 of this embodiment, the reference information update unit 38 updates the first reference position 101 in accordance with the first movement or first operation of the tractor 1 when performing automatic straight-line driving, and updates the second reference position 102 in accordance with the second movement or second operation of the tractor 1.

[0089] This reduces the burden on the operator by updating the first reference position 101 and the second reference position 102 in relation to the operation and control of the tractor 1 when it is performing automatic straight-line driving. Alternatively, the reference information update unit 38 may be able to update the first reference position 101 and the second reference position 102 in response to the operation of the first reference position operation unit 41 and the second reference position operation unit 42 during automatic straight-line driving.

[0090] Furthermore, according to the tractor 1 of this embodiment, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 at predetermined intervals when performing automatic straight-line driving.

[0091] Specifically, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 each time automatic straight-line driving starts, as per a predetermined period.

[0092] Alternatively, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 each time it completes a predetermined number of automatic straight-line driving routes based on the reference direction 103 and starts automatic straight-line driving of the next route, as defined by a predetermined period.

[0093] Alternatively, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 at intervals of a predetermined time elapsed since the previous setting of the first reference position 101 and the second reference position 102.

[0094] This reduces the burden on the operator by automatically updating the first reference position 101 and the second reference position 102 at predetermined intervals. Furthermore, when performing automatic straight-line driving, updating the first reference position 101 and the second reference position 102 at predetermined intervals and updating the reference direction 103 accordingly can suppress the occurrence of automatic straight-line driving that is not parallel to the driving trajectory when the reference direction 103 was first set, or the actual driving trajectory of automatic straight-line driving based on the initially set reference direction 103, or automatic straight-line driving that is not at equal intervals.

[0095] Furthermore, according to the tractor 1 of this embodiment, the reference information update unit 38 provides notification prompting manual driving to update the first reference position 101 and the second reference position 102 when a second predetermined time, which is longer than the first predetermined time, has elapsed since the previous setting of the first reference position 101 and the second reference position 102.

[0096] As a result, if a second predetermined time elapses during automatic straight-line driving without the first reference position 101 and the second reference position 102 being updated, and there is a possibility that the occurrence of a deviation in the position information measured by the positioning unit 15 cannot be suppressed, the operator can be prompted to update the first reference position 101 and the second reference position 102 by manual driving.

[0097] According to the tractor 1 of this embodiment, the reference information update unit 38 updates the first reference position 101 and the second reference position 102 when performing automatic straight-line driving and when predetermined permission conditions are met.

[0098] This prevents the first reference position 101 and the second reference position 102 from being updated by location information acquired under inappropriate conditions.

[0099] In the above-described embodiment, the setting and updating of data related to automatic straight-line driving was explained in an example in which the reference information setting unit 35, route creation unit 36, and reference information update unit 38 are executed by the control device 4 provided in the tractor 1. However, the present invention is not limited to this example. For example, in another example, the reference information setting unit 35, route creation unit 36, and reference information update unit 38 may be configured to be executed by a computer provided in a mobile terminal 5.

[0100] In other words, according to this embodiment, the automatic driving system for a work vehicle such as a tractor 1 only needs to include a reference information setting unit 35, a route creation unit 36, and a reference information update unit 38. Here, the reference information setting unit 35, the route creation unit 36, and the reference information update unit 38 may be executed by the control device 4 of the tractor 1, or they may be executed by the computer of the mobile terminal 5.

[0101] In the embodiments described above, an example was explained in which the work vehicle is composed of a tractor 1, but the present invention is not limited to this example. For example, the work vehicle of the present invention may be composed of other agricultural machinery such as a combine harvester, rice transplanter, or lawnmower, or it may be composed of other work vehicles other than agricultural machinery.

[0102] Furthermore, the present invention may be modified as appropriate, provided that it does not contradict the gist or idea of ​​the invention as can be inferred from the claims and the specification as a whole. Automated driving methods, work vehicles, and automated driving systems that involve such modifications are also included in the technical concept of the present invention.

[0103] [Notes on the invention] The following is an overview of the invention extracted from the above-described embodiments. Note that each configuration and processing function described below can be selected and combined as desired.

[0104] <Note 1> An automatic driving method for a work vehicle that drives automatically based on a reference direction set based on a first reference position and a second reference position, An automated driving method characterized by having an update step in which the first reference position and the second reference position are updated when performing the automated driving, and the reference direction is updated based on the updated first reference position and the second reference position.

[0105] <Note 2> The automatic driving method according to Appendix 1, characterized in that the update step updates the first reference position in accordance with the first movement or operation of the work vehicle when performing the automatic driving, and updates the second reference position in accordance with the second movement or operation of the work vehicle.

[0106] <Note 3> The automatic driving method according to Appendix 1 or 2, characterized in that the update step updates the first reference position and the second reference position at predetermined intervals when performing the automatic driving.

[0107] <Note 4> The automatic driving method according to Appendix 3, characterized in that the update step is performed by updating the first reference position and the second reference position each time the automatic driving starts, as defined by the predetermined period.

[0108] <Note 5> The automatic driving method according to Appendix 3, characterized in that the update step is performed each time the automatic driving of a predetermined number of routes based on the reference direction is completed and the automatic driving of the next route is started, the first reference position and the second reference position are updated during the predetermined period.

[0109] <Note 6> The automatic driving method according to Appendix 3, characterized in that the update step updates the first reference position and the second reference position at intervals of a first predetermined time elapsed since the previous setting of the first reference position and the second reference position, which is the predetermined period.

[0110] <Note 7> The automatic driving method according to Appendix 6, characterized in that the update step provides notification prompting manual driving to update the first reference position and the second reference position when a second predetermined time, which is longer than the first predetermined time, has elapsed since the previous setting of the first reference position and the second reference position.

[0111] <Note 8> The automatic driving method according to any one of the appendices 1 to 7, characterized in that the update step updates the first reference position and the second reference position when the automatic driving is performed and predetermined permission conditions are met.

[0112] <Note 9> A work vehicle that automatically drives based on a reference direction set based on a first reference position and a second reference position, A work vehicle characterized by comprising a reference information update unit that updates the first reference position and the second reference position when performing the aforementioned automatic driving, and updates the reference direction based on the updated first reference position and the second reference position.

[0113] <Note 10> The work vehicle according to Appendix 9, characterized in that the reference information update unit updates the first reference position in accordance with the first movement or operation of the work vehicle when performing the automatic driving, and updates the second reference position in accordance with the second movement or operation of the work vehicle.

[0114] <Note 11> The work vehicle according to Appendix 9 or 10, characterized in that the reference information update unit updates the first reference position and the second reference position at predetermined intervals when performing the automatic driving.

[0115] <Note 12> The work vehicle according to Appendix 11, characterized in that the reference information update unit updates the first reference position and the second reference position each time the automatic driving starts, as defined by the predetermined period.

[0116] <Note 13> The work vehicle according to Appendix 11, characterized in that the reference information update unit updates the first reference position and the second reference position each time it completes the automatic driving of a predetermined number of routes based on the reference direction and starts the automatic driving of the next route, as defined in the predetermined period.

[0117] <Note 14> The work vehicle according to Appendix 11, characterized in that the reference information update unit updates the first reference position and the second reference position every first predetermined time elapsed since the previous setting of the first reference position and the second reference position, which is the predetermined period.

[0118] <Note 15> The work vehicle according to Appendix 14, characterized in that the reference information update unit provides notification prompting manual driving to update the first reference position and the second reference position when a second predetermined time, which is longer than the first predetermined time, has elapsed since the previous setting of the first reference position and the second reference position.

[0119] <Note 16> The work vehicle according to any one of the appendices 9 to 15, characterized in that the reference information update unit updates the first reference position and the second reference position when the predetermined permission conditions are met during the automatic driving.

[0120] <Note 17> An automated driving system for a work vehicle that automatically drives based on a reference direction set based on a first reference position and a second reference position, An automated driving system characterized by comprising a reference information update unit that updates the first reference position and the second reference position when performing the automated driving, and updates the reference direction based on the updated first reference position and the second reference position.

[0121] <Note 18> The automatic driving system according to Appendix 17, characterized in that the reference information update unit updates the first reference position in accordance with the first movement or operation of the work vehicle when performing the automatic driving, and updates the second reference position in accordance with the second movement or operation of the work vehicle.

[0122] <Note 19> The automatic driving system according to Appendix 17 or 18, characterized in that the reference information update unit updates the first reference position and the second reference position at predetermined intervals when performing the automatic driving.

[0123] <Note 20> The automatic driving system according to Appendix 19, characterized in that the reference information update unit updates the first reference position and the second reference position each time the automatic driving starts, as defined by the predetermined period.

[0124] <Note 21> The automatic driving system according to Appendix 19, characterized in that the reference information update unit updates the first reference position and the second reference position each time it finishes automatic driving of a predetermined number of routes based on the reference direction and starts automatic driving of the next route, as defined in the predetermined period.

[0125] <Note 22> The automatic driving system according to Appendix 19, characterized in that the reference information update unit updates the first reference position and the second reference position every first predetermined time elapsed since the previous setting of the first reference position and the second reference position, which is the predetermined period.

[0126] <Note 23> The automatic driving system according to Appendix 22, characterized in that the reference information update unit provides notification prompting manual driving to update the first reference position and the second reference position when a second predetermined time, which is longer than the first predetermined time, has elapsed since the previous setting of the first reference position and the second reference position.

[0127] <Note 24> The automatic driving system according to any one of the appendices 17 to 23, characterized in that the reference information update unit updates the first reference position and the second reference position when predetermined permission conditions are met during the automatic driving. [Explanation of symbols]

[0128] 1. Tractor (work vehicle) 2 car bodies 3. Work equipment 4. Control device 5 Mobile devices 15 Positioning Units 31 Storage section 32 Communications Department 35. Standard Information Setting Unit 36 Route Creation Section 37 Automatic Driving Control Unit 38 Standard information update department 41 1st reference position operation section 42 2nd reference position operation section 43 Offset Buttons 44 Display device 45 speakers 100 fields 101, 101' 1st reference position 102, 102' 2nd reference position 103, 103' Reference direction Route 104, 104'

Claims

1. An automatic driving method for a work vehicle that drives automatically based on a reference direction set based on a first reference position and a second reference position, An automated driving method characterized by having an update step in which the first reference position and the second reference position are updated when performing the automated driving, and the reference direction is updated based on the updated first reference position and the second reference position.

2. The automatic driving method according to claim 1, characterized in that the update step updates the first reference position in accordance with the first movement or first operation of the work vehicle when performing the automatic driving, and updates the second reference position in accordance with the second movement or second operation of the work vehicle.

3. The automatic driving method according to claim 1, characterized in that the update step updates the first reference position and the second reference position at predetermined intervals when performing the automatic driving.

4. The automatic driving method according to claim 3, characterized in that the update step is performed by updating the first reference position and the second reference position each time the automatic driving starts, as the predetermined period.

5. The automatic driving method according to claim 3, characterized in that the update step is performed each time the automatic driving of a predetermined number of routes based on the reference direction is completed and the automatic driving of the next route is started, the first reference position and the second reference position are updated during the predetermined period.

6. The automatic driving method according to claim 3, characterized in that the update step is performed by updating the first reference position and the second reference position at intervals of a first predetermined time elapsed since the previous setting of the first reference position and the second reference position, which is the predetermined period.

7. The automatic driving method according to claim 6, characterized in that the update step provides notification prompting manual driving to update the first reference position and the second reference position when a second predetermined time, which is longer than the first predetermined time, has elapsed since the previous setting of the first reference position and the second reference position.

8. The automatic driving method according to claim 1, characterized in that the update step updates the first reference position and the second reference position when the automatic driving is performed and predetermined permission conditions are met.

9. A work vehicle that automatically drives based on a reference direction set based on a first reference position and a second reference position, A work vehicle characterized by comprising a reference information update unit that updates the first reference position and the second reference position when performing the aforementioned automatic driving, and updates the reference direction based on the updated first reference position and the second reference position.

10. An automated driving system for a work vehicle that automatically drives based on a reference direction set based on a first reference position and a second reference position, An automated driving system characterized by comprising a reference information update unit that updates the first reference position and the second reference position when performing the automated driving, and updates the reference direction based on the updated first reference position and the second reference position.

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