Control system and control method of agricultural tractor capable of autonomous work

Abstract

The present invention relates to a control system and a control method of an agricultural tractor capable of autonomous work. The present invention provides a control system and a control method of an agricultural tractor capable of autonomous work. The control system of an agricultural tractor capable of autonomous work comprises a turning driving control unit for selectively operating one of a first brake or a second brake when a steering device is operated to move the agricultural tractor while turning from any one straight working path (hereinafter referred to as an "immediately preceding straight working path") included in an autonomous working path to another adjacent straight working path (hereinafter referred to as a "next straight working path"). According to the present invention, there is an effect of providing convenience for turning driving when moving between straight working paths for autonomous work.

Description

Control system and control method for an agricultural tractor capable of autonomous operation

[0001] The present invention relates to an agricultural tractor capable of autonomous operation and concerns control technology for the agricultural tractor.

[0002] Recently, as a solution to address labor shortages and the aging workforce in the agricultural sector, active research is being conducted on agricultural tractors that can directly assist with farming tasks, going beyond autonomous driving that operates without operator intervention.

[0003] Agricultural tractors capable of such autonomous work (hereinafter referred to as "autonomous work tractors") can be classified into several stages depending on the level of worker intervention and the level of automation of the agricultural tractor, ranging from a stage where autonomous work limited to some functions is supported while a worker is on board the agricultural tractor to a stage where all functions are performed autonomously in an unmanned state.

[0004] The most basic autonomous work mode performed by the autonomous work tractor is AB Line Mode.

[0005] AB Mode sets point A, the starting point of the agricultural work, and point B, the ending point, as a reference line. When straight work paths parallel to the reference line are generated based on the reference line, it supports the autonomous work tractor in driving along the straight work paths to perform the work.

[0006] However, AB Mode does not support fully autonomous operation but rather autonomous operation limited to straight paths. In AB Mode, when an autonomous work tractor moves to an adjacent straight path after completing a task on one straight path, turning maneuvers must be performed, which require direct intervention from an operator.

[0007] However, autonomous work tractors are not only larger than conventional vehicles to tow implements for agricultural work, but their turning radius is also larger than 3 m. In other words, since the turning radius of an autonomous tractor is substantial, it is difficult to turn in one go by simply operating the steering wheel, which caused inconveniences such as taking a wider path or reversing.

[0008] Conventional agricultural tractors are equipped with an offset braking function to control the brakes on the left and right rear wheels to operate independently, in order to minimize the turning radius.

[0009] The autonomous work tractor is also equipped with a single brake function, but in order to properly use the manual single brake function, operation to operate the aforementioned brakes individually along with the steering wheel must be involved, so the operator's attention is required every time.

[0010] When turning the autonomous work tractor to move it to a straight work path for the next autonomous task, even if the side brake function is used, it operates only to the extent of the operator's intuition, so it may be difficult to accurately position the autonomous work tractor on the next straight work path depending on the operator's skill level.

[0011] When an autonomous work tractor performs autonomous work in AB mode and requires operator intervention during turning, the tractor will inevitably deviate from the predetermined work path if the operator misses the turning timing or turns inaccurately.

[0012] If the autonomous work tractor deviates from the predetermined work path, it is inevitable that the work completion time will be delayed by the amount of time required to return to the straight work path it intended to travel.

[0013] If an autonomous work tractor resumes autonomous operation while deviating from a predetermined work path, problems such as work omissions or duplicate work may occur.

[0014] In these autonomous work tractors, the maneuvering method dependent on the operator needs to be improved not only in terms of operator convenience but also in terms of work efficiency.

[0015] This invention was conceived from the consideration of ensuring high work precision while minimizing operator intervention for turning maneuvers.

[0016] To achieve this purpose, a control system for an agricultural tractor capable of autonomous operation according to one embodiment of the present invention comprises: a driving unit (100) for driving an agricultural tractor (T); and an integrated controller (300) for generating an autonomous operation path and controlling the operation of the driving unit (100) so that the agricultural tractor (T) can perform autonomous operation along the generated autonomous operation path; wherein the driving unit (100) comprises: a steering unit (130) for changing the driving direction of the agricultural tractor (T); and a brake device (150) for applying braking force to at least one of a first driving wheel (121c) and a second driving wheel (121d) having the agricultural tractor (T); and wherein the brake device (150) comprises a first brake (151b) for executing braking of the first driving wheel (121c); and a second brake (152b) for executing braking of the second drive wheel (121d); and the integrated controller (300) may include: a path generation unit (310) for generating an autonomous work path; an autonomous work control unit (320) for controlling the drive unit (100) to drive the autonomous work path generated by the path generation unit (310) and perform autonomous work; and a turning driving control unit (330) for selectively operating either the first brake (151b) or the second brake (152b) when the steering unit (130) is operated to turn and move from one straight work path (hereinafter referred to as the 'previous straight work path') included in the autonomous work path to another adjacent straight work path (hereinafter referred to as the 'next straight work path').

[0017] The above-described turning driving control unit (330) includes a steering detection part (331) that detects the steering angle of the steering handle (131) of the steering device (130); and when the steering angle detected by the steering detection part (331) is greater than or equal to a preset value, the turning driving control unit (330) can selectively operate the first brake (151b) or the second brake (152b) based on a brake pressure determined according to the width between the straight work paths, which is the gap between the previous straight work path and the next straight work path.

[0018] The above-mentioned turning driving control unit (330) includes a steering detection part (331) that detects the steering angle of the steering handle (131) of the steering device (130); and the turning driving control unit (330) can selectively operate the first brake (151b) or the second brake (152b) based on a brake pressure determined according to the width of the implement mounted on the agricultural tractor (T) when the steering angle detected by the steering detection part (331) is greater than or equal to a preset value.

[0019] The above setting value may be 80% of the maximum rotation angle at which the steering wheel (131) can rotate in the forward or reverse direction.

[0020] The above-mentioned turning driving control unit (330) may further include: a storage portion (332) in which reference data for determining a side brake pressure is stored; a calculation portion (333) for calculating a side brake pressure to be applied to the first brake or the second brake from the reference data; and a side brake control portion (334) for controlling the brake device (150) so that the first brake (151b) or the second brake (152b) operates with a braking force corresponding to the side brake pressure calculated in the calculation portion (333).

[0021] The above reference data includes a correlation of the uneven brake pressure according to the width between straight work paths or a correlation of the uneven brake pressure according to the width of the work implement, and in the above reference data, the width between the straight work paths or the width of the work implement may have an inverse relationship with the uneven brake pressure.

[0022] The above brake device (150) includes a brake valve (154) for controlling at least one of the braking force applied by the first brake (151b) to the first drive wheel (121c) and the braking force applied by the second brake (152b) to the second drive wheel (121d); and the single brake control part (334) can control the operation of the brake valve (154) so ​​that the braking force applied to the first drive wheel (121c) or the second drive wheel (121d) by the first brake (151b) or the second brake (152b) which functions as a single brake is adjusted.

[0023] The above agricultural tractor (T) further includes a setting unit (200) for setting an autonomous work mode, wherein the autonomous work mode includes an AB Line Mode, and the path generation unit (310) can generate the autonomous work path according to the autonomous work mode set by the setting unit (200).

[0024] Meanwhile, to achieve the above-mentioned purpose, a control method for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention comprises: a path generation step (S100) for generating an autonomous work path including a plurality of straight work paths parallel to a reference straight line; an autonomous operation step (S200) in which an agricultural tractor (T) drives on one of the straight work paths (hereinafter referred to as the 'previous straight work path') in the autonomous work path generated in the path generation step and performs work; and a turning driving step (S300) in which, when a steering device (130) is operated to turn and move toward a straight work path adjacent to the previous straight work path (hereinafter referred to as the 'next straight work path'), either a first brake (151b) or a second brake (152b) configured in a brake device (150) is selectively operated. and may include an additional autonomous work step (S400) in which, when the agricultural tractor (T) is positioned on a straight work path for the next autonomous work through the turning drive step, the agricultural tractor (T) drives on the straight work path where it is positioned and performs work.

[0025] The above turning driving step (S300) may include: a steering detection step (S310) for detecting the steering angle of the steering handle (131) of the steering device (130); and a turning driving control step (S320) for controlling the agricultural tractor (T) to turn according to the steering angle detected in the steering detection step (S310).

[0026] The above turning driving control step (S320) can selectively operate the first brake (151b) or the second brake (152b) based on a differential brake pressure determined by the width between the straight work paths, which is the interval between the previous straight work path and the next straight work path, when the steering angle is greater than or equal to a preset value.

[0027] In the above turning driving step (S300), if the steering angle is greater than or equal to a preset value, the first brake (151b) or the second brake (152b) may be selectively operated based on the single brake pressure determined according to the width of the straight work path and the implement mounted on the agricultural tractor (T).

[0028] The above setting value may be 80% of the maximum rotation angle at which the steering wheel (131) can rotate in the forward or reverse direction.

[0029] The above turning driving control step (S320) may include: a calculation step (S321) for calculating a unilateral brake pressure to be applied to the first brake (151b) or the second brake (152b) from reference data for determining the unilateral brake pressure; and a unilateral brake control step (S322) for controlling the brake device (150) so that the first brake (151b) or the second brake (152b) is operated with a braking force corresponding to the unilateral brake pressure calculated in the calculation step (330).

[0030] The above reference data includes a correlation of the uneven brake pressure according to the width between straight work paths or a correlation of the uneven brake pressure according to the width of the work implement, and in the above reference data, the width between the straight work paths or the width of the work implement may have an inverse relationship with the uneven brake pressure.

[0031] As explained above, according to the present invention, the following effects can be derived.

[0032] First, it can provide convenience for turning when moving between straight work paths for autonomous work.

[0033] Second, high work precision can be guaranteed.

[0034] Third, work continuity can be ensured.

[0035] Fourth, it can contribute to improving work efficiency by minimizing wasted time during turning.

[0036] Ultimately, it is expected to serve as a starting point for solving rural labor problems by enabling high production volumes with minimal labor.

[0037] FIGS. 1 to 3 are block diagrams illustrating a control system for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention.

[0038] FIGS. 4 and 6 are reference diagrams for explaining a control system of an agricultural tractor capable of autonomous operation according to an embodiment of the present invention.

[0039] Figures 5 and 7 illustrate reference data used in the control system of an agricultural tractor capable of autonomous operation, as exemplified in Figure 3.

[0040] FIG. 8 is a flowchart illustrating a control method for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention.

[0041] FIGS. 9a and 9b are reference drawings for explaining the utility of the present invention.

[0042] Preferred embodiments according to the present invention are described with reference to the accompanying drawings, provided that for the sake of brevity, descriptions of well-known configurations are omitted or compressed as much as possible.

[0043] The term "autonomous work" as used in the present invention means that an agricultural tractor performs at least one of driving and working while minimizing the intervention of a worker.

[0044] The agricultural tractor capable of autonomous operation mentioned in the present invention includes both models produced to enable autonomous operation and agricultural tractors equipped with an autonomous operation kit to support certain autonomous operation modes.

[0045] Agricultural tractors capable of autonomous operation are fundamentally equipped with position sensors; additionally, object detection sensors to recognize the surrounding environment, attitude detection sensors to detect the posture of the tractor and implements, and operation detection sensors to detect the operating status of the implements may be configured. These sensors communicate with the integrated controller described later and provide information necessary for the operation of the agricultural tractor during autonomous operation. Since these are elements recommended for smooth autonomous operation, specific details are omitted in the following description.

[0046] In the case of an agricultural tractor capable of autonomous operation, the configuration of a conventional agricultural tractor may be added to, subtracted from, or replaced depending on the level of operator intervention and automation. The aforementioned sensors may also be added to, subtracted from, or replaced depending on the level of operator intervention and automation.

[0047] In the case of the present invention, the description is intended to be limited to an agricultural tractor that provides the most basic autonomous operation mode, AB Line Mode, but the technical features are not limited thereto.

[0048] Below, we will explain the control system of an agricultural tractor capable of autonomous operation.

[0049] <Explanation of the control system for autonomous agricultural tractors>

[0050] FIG. 1 is a block diagram illustrating a control system for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention; FIG. 2 is a block diagram illustrating a drive unit in the control system for an agricultural tractor capable of autonomous operation illustrated in FIG. 1; FIG. 3 is a block diagram illustrating an integrated controller in the control system for an agricultural tractor capable of autonomous operation illustrated in FIG. 1; FIG. 4 and FIG. 6 are reference diagrams for explaining a control system for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention; and FIG. 5 and FIG. 7 illustrate reference data utilized in the control system for an agricultural tractor capable of autonomous operation illustrated in FIG. 3.

[0051] Referring to FIGS. 1 to 4, a control system (10) of an agricultural tractor capable of autonomous operation according to one embodiment of the present invention includes a driving unit (100), a setting unit (200), and an integrated controller (300).

[0052] The drive unit (100) is configured to drive an agricultural tractor (T). Refer to FIGS. 2 and FIGS. 4 in this regard.

[0053] The drive unit (100) is equipped with components related to driving and working of the agricultural tractor (T).

[0054] The drive unit (100) includes a drive source (110), a connecting device (PTO), a driving device (120), a steering device (130), a transmission (140), and a braking device (150).

[0055] The driving source (110) generates driving force.

[0056] The driving force generated from the driving source (110) is rotational force.

[0057] The driving force generated by the driving source (110) can be used as driving power by the driving machine (120) or as working power by the working machine (W).

[0058] As a driving source (110), at least one of a driving motor operated by an engine or a battery may be applied.

[0059] The connecting device (PTO) is configured to transmit the driving force of the driving source (110) to the implement (W) mounted on the agricultural tractor (T).

[0060] The driving device (120) is provided for driving the agricultural tractor (T).

[0061] The driving device (120) is driven by the driving force of the driving source (110).

[0062] The driving device (120) has a plurality of driving wheels (121a, 121b, 121c, 121d).

[0063] Multiple drive wheels (121a, 121b, 121c, 121d) are configured to drive on the work site and can be divided into front wheels (FW) and rear wheels (RW).

[0064] The drive wheels (121a, 121b) positioned as front wheels (FW) function as steering wheels for changing the direction of travel. The remaining drive wheels (121c, 121d) are positioned as rear wheels (RW).

[0065] The steering device (130) is configured to change the direction of the driving device (120).

[0066] The steering device (130) includes a steering handle (131) and a steering valve (132).

[0067] The steering handle (131) is provided in the form of a steering wheel.

[0068] The steering wheel (131) can be operated by a worker.

[0069] The steering valve (132) adjusts the steering angle of the front wheel (FW).

[0070] The steering valve (132) may be a proportional control valve that can be electronically controlled.

[0071] The steering valve (132) steers the front wheel (FW) by an amount corresponding to the amount of rotation of the steering wheel (131).

[0072] The amount of rotation of the steering wheel (132), i.e., the steering angle, can be obtained from a steering sensor (not shown) for detecting this.

[0073] The steering sensor provides a detection value for the steering angle of the steering wheel (132) to the integrated controller (300) in real time.

[0074] The steering valve (132) may steer the front wheel (FW) by the control of an integrated controller (300) to support autonomous operation of the agricultural tractor (T).

[0075] The transmission (140) transmits the driving force of the driving source (110) to the driving device (120).

[0076] The transmission (140) can change the rotational speed during the process of transmitting driving force to the driving machine (120) and transmit it to the driving machine (120). When the rotational speed is changed by the transmission (140), the driving speed of the driving machine (120) is also changed proportionally.

[0077] The transmission (140) can be controlled electronically.

[0078] The transmission (140) may include an operating part (141) and a transmission execution part (142).

[0079] The control part (141) is configured to command a gear shift by the operator's operation.

[0080] The operating part (141) may include a forward / reverse operating means (141a) and a gear shift operating means (141b).

[0081] A worker command for forward or reverse driving of the agricultural tractor can be input by operating the forward / reverse driving means (141a).

[0082] A worker command to change the driving speed of the driving device (120) can be input by operating the gear shifting means (141b).

[0083] The forward / reverse operation means (141a) and the gear shift operation means (141b) can each be provided as a gear shift lever and a gear shift pedal.

[0084] It is also possible for both the forward / reverse operation means (141a) and the gear shift operation means (141b) to be provided as gear shift pedals. In this case, the operation part (141) may be provided as a plurality of gear shift pedals for commanding forward shifting and reverse shifting, respectively.

[0085] The gear shift execution part (142) is configured to execute gear shifts according to the operator's command coming through the operation part (141).

[0086] The transmission execution part (142) may be appropriately controlled by the control of an integrated controller (300) to support autonomous operation of the agricultural tractor (T).

[0087] When a control command for forward or reverse driving of an agricultural tractor (T) is input through the operation part (141) or the integrated controller (300), the transmission execution part (142) switches the rotational direction of the driving force generated from the driving source (110) to forward (forward) or reverse (reverse) and transmits it to the driving device (120) so that the rotational direction of the driving wheels (121a, 121b, 121c, 121d) is switched to forward rotation (forward) or reverse rotation (reverse).

[0088] When a control command for the driving speed of an agricultural tractor (T) is input through the operation part (141) or the integrated controller (300), the transmission execution part (142) transmits the rotational speed of the driving force generated from the driving source (110) to the driving device (120) so as to correspond to the driving speed.

[0089] The braking device (150) is configured to brake the vehicle (120).

[0090] The brake device (150) can be controlled electronically.

[0091] The brake device (150) includes a first brake operating means (151), a second brake operating means (152), a differential locking means (153), and a brake valve (154).

[0092] The first brake operating means (151) is configured to apply braking force to one of the plurality of drive wheels (121a, 121b, 121c, 121d) (hereinafter referred to as the 'first drive wheel (121c)').

[0093] The first brake operating means (151) includes a first brake pedal (151a) and a first brake (151b).

[0094] The first brake pedal (151a) is configured to command braking by operation of the operator.

[0095] The first brake (151b) is configured to perform braking of the first drive wheel (121c).

[0096] The first brake (151b) can perform braking of the first drive wheel (121c) according to a worker command coming through the first brake pedal (151a).

[0097] When the operator steps on the first brake pedal (151a), the first brake (151b) is actuated by the components linked thereto, and the rotation of the first drive wheel (121c) positioned on the rear wheel (RW) of the agricultural tractor can be decelerated or stopped.

[0098] The first brake (151b) can be controlled by the integrated controller (300) to perform braking of the first drive wheel (131c). This will be explained again in the description of the integrated controller (300).

[0099] The second brake operating means (152) is configured to apply braking force to one of the multiple drive wheels (121a, 121b, 121c, 121d) (hereinafter referred to as the 'second drive wheel (121d)').

[0100] The second brake operating means (152) includes a second brake pedal (152a) and a second brake (152b).

[0101] The second brake pedal (152a) is configured to command braking by operation of the operator.

[0102] The second brake (152b) is configured to perform braking of the second drive wheel (121d) in accordance with a worker command coming through the second brake pedal (152a).

[0103] When the operator steps on the second brake pedal (152a), the second brake (152b) is actuated by the components linked thereto, and the rotation of the second drive wheel (121d) positioned on the rear wheel (RW) of the agricultural tractor can be decelerated or stopped.

[0104] The second brake (152b) may be controlled by the integrated controller (300) to perform braking of the second drive wheel (131d). This will be explained again in the description of the integrated controller (300).

[0105] The differential locking means (153) is configured to regulate the operation of the first brake operating means (151) and the second brake operating means (152) so that they operate in conjunction with each other.

[0106] When the operation of the first brake operating means (151) and the second brake operating means (152) by the differential locking means (153) is restricted, the first brake operating means (151) and the second brake operating means (152) operate together.

[0107] When the regulation of the first brake operating means (151) and the second brake operating means (152) by the differential locking means (153) is released, the first brake operating means (151) or the second brake operating means (152) of the brake device (150) can operate independently.

[0108] In this case, the brake device (150) functions as a selective brake that applies braking force to either the first drive wheel (121c) or the second drive wheel (121d).

[0109] When the brake device (150) functions as a single brake, the agricultural tractor (T) rotates with the drive wheel to which the braking force is applied as the approximate center of rotation.

[0110] For reference, when the side brake function is automatically operated by the control of the integrated controller (300) without the intervention of a worker, the restriction by the differential locking means (153) may be temporarily released.

[0111] For example, the automatic differential braking function by the integrated controller (300) is performed when the steering wheel (131) is recognized as being turned almost completely in the forward or reverse direction, and when this state of the steering wheel (131) is recognized, the regulation of the differential locking means (153) may be implemented to be automatically released.

[0112] When turning driving under the control of the integrated controller (300) is completed, the regulation of the first brake operating means (151) and the second brake operating means (152) by the differential locking means (153) can be resumed.

[0113] Of course, when the differential brake function is used manually by the operator, the regulation of the differential locking means (153) is determined according to the operator's intention.

[0114] The brake valve (154) controls the braking force provided to at least one of the first drive wheel (121c) and the second drive wheel (121d).

[0115] The brake valve (154) may be an electro-hydraulic brake valve that can be electronically controlled.

[0116] The brake valve (154) can be controlled by the integrated controller (300).

[0117] The integrated controller (300) adjusts the braking force applied to the first drive wheel (121c) or the second drive wheel (121d) by the first brake (151a) or the second brake (152b) which functions as a single brake.

[0118] For example, the integrated controller (300) calculates an appropriate brake pressure by referring to reference data stored in the storage portion (332) to be described later, and appropriately controls the hydraulic pressure supplied from the brake valve (154) to the first brake (151b) or the second brake (152b) so that a braking force corresponding to the calculated brake pressure can be generated.

[0119] In controlling the operation of the brake valve (154) by the integrated controller (300), information on the brake pressure applied to each drive wheel (121c, 121d) positioned on the rear wheel (RW) and monitoring information on the operating status of the brake valve (154) may be referenced. This information may be collected by detection sensors (not shown) installed on the agricultural tractor (T) and provided to the integrated controller (300).

[0120] As the brake valve (154) is controlled by the integrated controller (300), the agricultural tractor (T) can turn and drive with an appropriate turning radius without the intervention of a worker and be positioned accurately on the next straight work path.

[0121] For reference, although the driving wheels to which the first brake operating means (151) and the second brake operating means (152) mentioned above apply braking force are described as driving wheels (121c, 121d) positioned on the rear wheels (RW) of the agricultural tractor (T), they are not limited thereto and can, of course, be arranged to apply braking force to driving wheels (121a, 121b) positioned on the front wheels (FW). In this case, each component of the brake device (150) applies braking force to at least one of the driving wheels (121a, 121b) positioned on the front wheels (FW) under the control of the integrated controller (300).

[0122] The setting unit (200) is configured to set the autonomous work mode of the agricultural tractor (T).

[0123] The setting unit (200) can be provided as a human-machine interface (HMI) device.

[0124] The setting unit (200) is provided in the form of an operating panel that allows the operator to display on a screen not only the overall condition of the agricultural tractor but also the driving and work conditions, and to input the overall driving conditions as well as the setting of the autonomous work mode of the agricultural tractor (T) through the screen.

[0125] The autonomous work mode includes AB mode. In addition, multiple autonomous work modes may be included to support the autonomous operation of the agricultural tractor (T), such as ABCD mode, which generates an autonomous work path and performs autonomous work when the boundaries of the work area are set.

[0126] For reference, when the operator selects AB mode through the setting unit (200), setting instructions for the reference line are displayed on the screen.

[0127] The operator sets points A and B to be set as a reference line through the screen, and when the setting of points A and B by the operator is completed, the path generation unit (310) of the integrated controller (300) generates an autonomous work path composed of multiple straight work paths parallel to the reference line based on this.

[0128] When an autonomous work path is generated, the agricultural tractor (T) performs autonomous work along the autonomous work path under the control of the integrated controller (300).

[0129] The integrated controller (300) generates an autonomous work path and controls the operation of the drive unit (100) so that the agricultural tractor (T) can perform autonomous work along the generated autonomous work path. Refer to FIGS. 3, 4, and 6 in this regard.

[0130] The integrated controller (300) includes a path generation unit (310), an autonomous work control unit (320), and a turning driving control unit (330).

[0131] The path generation unit (310) generates an autonomous work path.

[0132] The path generation unit (310) generates an autonomous work path according to the autonomous work mode set in the setting unit (200).

[0133] For example, if the autonomous work mode set in the setting unit (200) is AB mode, the path generation unit (310) generates straight autonomous work paths.

[0134] When point A (shown as A in FIG. 4) and point B (shown as B in FIG. 4) are set by a worker through the setting unit (200) before the path generation unit (310) generates straight autonomous work paths, the path generation unit (310) generates an autonomous work path composed of multiple straight work paths parallel to a reference line based on this.

[0135] If the setting of points A and B, i.e., reference points, is omitted by the worker, the path generation unit (310) can also generate an autonomous work path based on the status of previous work performed at that location.

[0136] When the path generation unit (310) generates straight work paths, the width length, which is the interval between the straight work paths, can be determined by reflecting tractor information such as the width of the agricultural tractor (T), turning radius, maximum steering angle, and specifications of the brake valve (154), and implement information such as the width of the implement (W).

[0137] The above tractor information may be stored in the integrated controller (300).

[0138] However, since the work device (W) is configured to be replaceable depending on the type of agricultural work, at least one of the type and width of the work device (W) can be input by the worker through the setting unit (200).

[0139] If all information regarding implements that can be connected to the corresponding agricultural tractor (T) is stored in the integrated controller (300), the operator only needs to select the type of implement (W) to be used through the setting unit (200). In this case, the integrated controller (300) receives the type of implement (W) selected by the operator from the setting unit (200) and provides the corresponding implement information to the path generation unit (310).

[0140] The autonomous work control unit (320) controls the drive unit (100) to perform autonomous work by driving along the autonomous work path generated by the path generation unit (310).

[0141] The autonomous work control unit (320) controls each component of the drive unit (100) so that the agricultural tractor (T) can work while driving in a straight line at an appropriate speed along the straight work paths generated by the path generation unit (310).

[0142] When the agricultural tractor (T) completes work on one straight work path by control by the autonomous work control unit (320), it moves to another straight work path adjacent to it (hereinafter referred to as the 'next straight work path').

[0143] The autonomous work control unit (320) resumes autonomous work on the next straight work path when the agricultural tractor (T) moves to the next straight work path.

[0144] The turning driving control unit (330) allows the agricultural tractor (T) to turn and move from one straight work path (hereinafter referred to as the 'previous straight work path') included in the autonomous work path to an adjacent next straight work path by selectively operating either the first brake (151b) or the second brake (152b) so as to move from the previous work path to the next straight work path.

[0145] The turning driving control unit (330) includes a steering detection unit (331), a storage unit (332), a calculation unit (333), and a side brake control unit (334).

[0146] The steering detection part (331) detects the steering angle of the steering handle (131) of the steering device (130).

[0147] The steering detection part (331) receives the detection value detected from the steering sensor in real time and compares the detection value with a preset setting value.

[0148] The steering detection part (331) also determines whether the rotation direction of the steering wheel (131) is forward or reverse based on the detection value. The rotation direction of the steering wheel (131) contributes to determining the configuration that functions as a bias brake among the first brake (151b) or the second brake (152b).

[0149] If the steering angle of the steering handle (131) included in the detected value through the steering detection part (331) is determined to be less than the set value, the integrated controller (300) does not intervene in turning driving so that the agricultural tractor (T) can be driven according to the operator's intention.

[0150] When it is determined through the steering detection part (331) that the steering angle of the steering handle (131) included in the detected value reaches a set value or has a value greater than that, the first brake (151b) or the second brake (152b) is selectively operated by the calculation part (333) and the differential brake control part (334).

[0151] The selective operation of the first brake (151b) or the second brake (152b) by the turning driving unit (330), that is, the execution of the automatic side brake function, can be based on the side brake pressure determined by the width between the straight work paths (shown as d in FIG. 4), which is the interval between the previous straight work path and the next straight work path.

[0152] The execution of the automatic side brake function by the turning drive unit (330) may be based on the side brake pressure determined according to the width (shown as Wd in FIG. 6) of the implement (W) mounted on the agricultural tractor (T).

[0153] In this regard, referring to FIG. 6, when the path generation unit (310) generates an autonomous work, the width (d) between the straight work paths is determined such that the two end portions partially overlap based on the width (Wd) of the work device (W) (the overlapping portion is shown as Od in FIG. 6). Consequently, since the width (d) between the straight work paths is determined by considering the width (Wd) of the work device (W), it may be desirable for the single brake pressure to be determined based on the width (Wd) of the work device (W).

[0154] The setting value may be set to 80% of the maximum rotation angle at which the steering wheel (131) can rotate in the forward or reverse direction.

[0155] The setting value may be set to the maximum rotation angle when the steering wheel (131) is turned to the end of one direction.

[0156] The design of the side brake function to operate automatically based on the set value is intended to prevent safety issues caused by misinterpreting the normal turning motion of the agricultural tractor (T).

[0157] Reference data for determining the brake pressure is stored in the storage portion (332).

[0158] Examples regarding reference data are illustrated in FIGS. 5 and 7. However, as this is merely an example, it is understood that it may vary depending on at least one of the tractor information, implement information, and the method of generating the reference data.

[0159] Figure 5 illustrates reference data regarding the correlation between single brake pressure and the width between straight work paths, where the width between straight work paths has an inverse relationship with single brake pressure. Referring to the correlation in the reference data, the single brake pressure is calculated to be higher as the width between straight work paths narrows.

[0160] Figure 7 illustrates reference data regarding the correlation between the uneven brake pressure and the width of the implement, where the width of the implement has an inverse relationship with the uneven brake pressure. Referring to the correlation in the reference data, the uneven brake pressure is calculated to be higher as the width of the implement decreases.

[0161] When generating reference data, at least one of tractor information and implement information may be considered.

[0162] For example, reference data can be generated by collecting differential brake information, such as turning radius and differential brake pressure, collected when the differential brake function is performed by an operator during actual or simulated driving, classifying the accumulated collected data by information type, and processing the data.

[0163] As another example, reference data can also be generated using a simulation program.

[0164] The calculation part (333) calculates the differential brake pressure to be applied to the first brake (151b) or the second brake (152b) from the reference data.

[0165] The calculation section (333) calculates the corresponding side brake pressure by reflecting the width between straight work paths or the width of the work machine among the autonomous work paths generated by the path generation section (310) in the reference data.

[0166] The single brake control section (334) controls the brake device (150) so that the first brake (151b) or the second brake (152b) operates with a braking force corresponding to the single brake pressure calculated in the calculation section (333).

[0167] More specifically, the single brake control section (334) controls the operation of the brake valve (154) so ​​that the braking force applied to the first drive wheel (121c) or the second drive wheel (121d) by the first brake (151b) or the second brake (152b) functioning as a single brake is adjusted to a braking force corresponding to the single brake pressure calculated in the calculation section (333).

[0168] The agricultural tractor (T), having completed turning by the single brake control section (334), can be accurately positioned on the next straight path of work.

[0169] When the agricultural tractor (T) is positioned on a straight work path for the next work after turning, autonomous work can be resumed by the autonomous work control unit (320).

[0170] Consequently, the present invention provides convenience in turning driving because, when an agricultural tractor (T) performs autonomous work in AB mode, the operator can accurately position itself on the next straight work path simply by turning the steering wheel (131) by a certain amount or more when moving from the previous straight work path to the next straight work path.

[0171] Below, we intend to conceptually explain the control method of an agricultural tractor capable of autonomous operation with reference to the drawings.

[0172] <Explanation of Control Methods for Agricultural Tractors Capable of Autonomous Operation>

[0173] FIG. 8 is a flowchart for explaining a control method for an agricultural tractor capable of autonomous operation according to an embodiment of the present invention, and FIG. 9a to 9b are reference diagrams for explaining the utility of the present invention.

[0174] Hereinafter, with reference to FIGS. 8, 9a, and 9b, a control method for an agricultural tractor capable of autonomous operation proposed by the present invention will be described. For reference, since the control method for an agricultural tractor capable of autonomous operation is executed by each component included in the control system (10) of the agricultural tractor capable of autonomous operation described above, a description that overlaps therewith is omitted.

[0175] 1. Path generation stage <s100>

[0176] The path generation step (S100) is a step of generating an autonomous work path that includes a plurality of straight work paths parallel to a reference straight line.

[0177] In the path generation step (S100), the path generation unit (310) can generate an optimal autonomous work path by considering tractor information, implement information and area information of the work target site, etc.

[0178] 2. Autonomous work stage <s200>

[0179] The autonomous work stage (S200) is a stage in which an agricultural tractor (T) performs work by driving along one of the straight work paths (hereinafter referred to as the ‘straight straight work path’) in the autonomous work path generated in the path generation stage.

[0180] In the autonomous work stage (S200), the autonomous work control unit (320) controls each component of the drive unit (100) so that the agricultural tractor (T) can work while driving in a straight line at an appropriate speed along the straight work paths generated by the path generation unit (310).

[0181] 3. Turning stage <s300>

[0182] The turning driving stage (S300) is a stage in which, when the steering device (130) is operated by an operator to turn and move the agricultural tractor (T) to a straight work path adjacent to the previous straight work path (hereinafter referred to as the 'next straight work path'), either the first brake (151b) or the second brake (152b) is selectively operated to enable movement from the previous straight work path to the next straight work path.

[0183] The turning driving step (S300) includes a steering detection step (S310) and a turning driving control step (S320).

[0184] The steering detection step (S310) is a step of detecting the steering angle of the steering wheel (131).

[0185] In the steering detection step (S310), the steering detection part (331) receives the steering angle of the steering handle (131) detected from the steering sensor and compares the received steering angle with a preset value.

[0186] In the steering detection step (S310), if the steering angle is determined to be less than the set value by the steering detection part (331), the integrated controller (300) does not intervene so that the agricultural tractor (T) can turn and drive according to the operator's intention. In this case, the agricultural tractor (T) that has turned and driven by the operator is positioned on the next straight work path and performs the additional autonomous work step (S400) to be described later.

[0187] In the steering detection step (S310), if the steering angle of the steering wheel (131) is determined by the steering detection part (331) to have reached a set value or to have a value greater than that, then turning driving is performed under the control of the integrated controller (300) through the turning driving control step (S320) to be described later.

[0188] The turning driving control step (S320) is a step of controlling the agricultural tractor (T) to turn according to the steering angle detected in the steering detection step (S310).

[0189] The turning driving control step (S320) includes a calculation step (S321) and a side brake control step (S322).

[0190] The calculation step (S321) is a step of calculating the unilateral brake pressure to be applied to the first brake (151b) or the second brake (152b) from reference data for determining the unilateral brake pressure.

[0191] In the calculation step (S321), the calculation part (333) calculates the corresponding side brake pressure by reflecting the width between straight work paths or the width of the work machine among the autonomous work paths generated by the path generation part (310) in the reference data.

[0192] The single brake control step (S322) is a step of controlling the brake device (150) so that the first brake (151b) or the second brake (152b) is actuated by a braking force corresponding to the single brake pressure calculated in the calculation step (330).

[0193] In the single brake control step (S322), the single brake control part (334) controls the operation of the brake valve (154) so ​​that the braking force applied to the first drive wheel (121c) or the second drive wheel (121d) by the first brake (151b) or the second brake (152b) functioning as a single brake is adjusted to a braking force corresponding to the single brake pressure calculated in the calculation step (S321).

[0194] When the turning drive is completed through the single brake control step (S322), the agricultural tractor (T) is positioned on the next straight work path.

[0195] 4. Additional autonomous work stage <s400>

[0196] The additional autonomous work stage (S400) is a stage in which, when the agricultural tractor (T) is positioned on a straight work path for the next autonomous work through the turning drive stage (S300), the agricultural tractor (T) drives on the straight work path where it is located and performs the work.

[0197] The additional autonomous work step (S400) can be performed by the autonomous work control unit (320).

[0198] When the additional autonomous work step (S400) is completed, turning is performed or the autonomous work is terminated depending on whether there is a next straight work path.

[0199] The utility of the present invention will be explained below with reference to the drawings.

[0200] FIG. 9a illustrates the driving path of a typical agricultural tractor (T) when turning while performing autonomous work in AB mode.

[0201] FIG. 9b illustrates the driving path of an agricultural tractor (T) in which an automatic side brake function is performed by an integrated controller (300) when turning while performing autonomous work in AB mode.

[0202] In the case of FIG. 9a, it can be seen that when turning from the previous straight work path due to the large turning radius of the agricultural tractor (T), the agricultural tractor (T) is positioned outside the next straight work path.

[0203] In the case of FIG. 9b, when the agricultural tractor (T) turns on the previous straight work path, the side brake function is automatically performed by control by the integrated controller (300), and it can be confirmed that the agricultural tractor (T) is accurately positioned on the next straight work path.

[0204] As confirmed in FIGS. 9a and 9b, by utilizing the present invention, the agricultural tractor (T) can be accurately moved to the next straight work path where the next autonomous work is scheduled, regardless of the operator's skill level, by utilizing the correlation between the width of the straight work path or the width of the implement and the single brake pressure, thereby ensuring high work precision.

[0205] The embodiments described above are merely preferred examples of the present invention and may have various applications. Therefore, the present invention should not be understood as being limited only to the contents described above. Instead, the scope of the present invention should be understood as the separately described claims and their equivalents.

Claims

A drive unit (100) for driving an agricultural tractor (T); and An integrated controller (300) that generates an autonomous work path and controls the operation of the drive unit (100) so that the agricultural tractor (T) can perform autonomous work along the generated autonomous work path; The above driving unit (100) is, A steering device (130) for changing the driving direction of the above agricultural tractor (T); and A brake device (150) for applying braking force to at least one of the first drive wheel (121c) and the second drive wheel (121d) of the agricultural tractor (T); comprising, The above brake device (150) is, A first brake (151b) for braking the first drive wheel (121c); and A second brake (152b) for executing braking of the second drive wheel (121d); comprising, The above integrated controller (300) is, Path generation unit (310) that generates an autonomous work path; An autonomous work control unit (320) that controls the driving unit (100) to perform autonomous work while driving the autonomous work path generated by the path generation unit (310); and A turning driving control unit (330) that selectively operates either the first brake (151b) or the second brake (152b) when the steering device (130) is operated to turn and move the agricultural tractor (T) from one straight work path (hereinafter referred to as the 'previous straight work path') included in the autonomous work path to another adjacent straight work path (hereinafter referred to as the 'next straight work path'); Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 1, The above-mentioned turning driving control unit (330) is, A steering sensing portion (331) for detecting the steering angle of the steering handle (131) having the above-mentioned steering device (130); comprising, The above-described turning driving control unit (330) selectively operates the first brake (151b) or the second brake (152b) based on a differential brake pressure determined by the width between the straight work paths, which is the interval between the previous straight work path and the next straight work path, when the steering angle detected by the steering detection unit (331) is greater than or equal to a preset value. Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 1, The above-mentioned turning driving control unit (330) is, A steering sensing portion (331) for detecting the steering angle of the steering handle (131) having the above-mentioned steering device (130); comprising, The above turning driving control unit (330) selectively operates the first brake (151b) or the second brake (152b) based on a side brake pressure determined according to the width of the implement mounted on the agricultural tractor (T) when the steering angle detected by the steering detection unit (331) is greater than or equal to a preset value. Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 2 or 3, The above setting value is 80% of the maximum rotation angle at which the steering wheel (131) can rotate in the forward or reverse direction. Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 2 or 3, The above-mentioned turning driving control unit (330) is, A storage portion (332) in which reference data for determining the brake pressure is stored; A calculation part (333) for calculating the differential brake pressure to be applied to the first brake or the second brake from the reference data above; and A brake control portion (334) that controls the brake device (150) so that the first brake (151b) or the second brake (152b) operates with a braking force corresponding to the brake pressure calculated in the above calculation portion (333); further comprising Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 5, The above reference data includes the correlation of uneven brake pressure according to the width between straight work paths or the correlation of uneven brake pressure according to the width of the work implement, and In the above reference data, the width between the straight work paths or the width of the work implement is inversely proportional to the single brake pressure. Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 5, The above brake device (150) is, A brake valve (154) for controlling at least one of the braking force applied by the first brake (151b) to the first drive wheel (121c) and the braking force applied by the second brake (152b) to the second drive wheel (121d); The above-mentioned single brake control portion (334) controls the operation of the brake valve (154) so ​​that the braking force applied to the first drive wheel (121c) or the second drive wheel (121d) by the first brake (151b) or the second brake (152b) which functions as a single brake is adjusted. Control system (10) for an agricultural tractor capable of autonomous driving. In paragraph 1, It further includes a setting unit (200) for setting the autonomous work mode of the agricultural tractor (T), and The above autonomous operation mode includes AB Line Mode, and The path generation unit (310) generates the autonomous work path according to the autonomous work mode set in the setting unit (200). Control system (10) for an agricultural tractor capable of autonomous driving. A path generation step (S100) for generating an autonomous work path including a plurality of straight work paths parallel to a reference line; An autonomous work step (S200) in which an agricultural tractor (T) performs work while driving on one of the straight work paths (hereinafter referred to as the 'straight straight work path') in the autonomous work path generated in the path generation step; A turning driving step (S300) in which, when the steering device (130) is operated to move the agricultural tractor (T) by turning toward a straight work path adjacent to the previous straight work path (hereinafter referred to as the 'next straight work path'), either the first brake (151b) or the second brake (152b) configured in the brake device (150) is selectively operated; and An additional autonomous work step (S400) comprising: when the agricultural tractor (T) is positioned on a straight work path for the next autonomous work through the turning drive step, driving on the straight work path where the agricultural tractor (T) is located and performing the work. Control method for an autonomous agricultural tractor. In Paragraph 9, The above turning driving step (S300) is, A steering detection step (S310) for detecting the steering angle of the steering handle (131) having the above-mentioned steering device (130); and A turning driving control step (S320) for controlling the agricultural tractor (T) to turn according to the steering angle detected in the steering detection step (S310); comprising Control method for an autonomous agricultural tractor. In Paragraph 10, The above turning driving control step (S320) selectively operates the first brake (151b) or the second brake (152b) based on a differential brake pressure determined by the width between the straight work paths, which is the interval between the previous straight work path and the next straight work path, when the steering angle is greater than or equal to a preset value. Control method for an autonomous agricultural tractor. In Paragraph 10, The above turning driving step (S300) selectively operates the first brake (151b) or the second brake (152b) based on a differential brake pressure determined according to the width of the straight work path and the implement mounted on the agricultural tractor (T) when the steering angle is greater than or equal to a preset value. Control method for an autonomous agricultural tractor. In Article 11 or Article 12, The above setting value is 80% of the maximum rotation angle at which the steering wheel (131) can rotate in the forward or reverse direction. Control method for an autonomous agricultural tractor. In Article 11 or Article 12, The above turning driving control step (S320) is A calculation step (S321) for calculating the differential brake pressure to be applied to the first brake (151b) or the second brake (152b) from reference data for determining the differential brake pressure; and A side brake control step (S322) for controlling the brake device (150) so that the first brake (151b) or the second brake (152b) is actuated by a braking force corresponding to the side brake pressure calculated in the above calculation step (330); comprising Control method for an autonomous agricultural tractor. In Paragraph 14, The above reference data includes the correlation of uneven brake pressure according to the width between straight work paths or the correlation of uneven brake pressure according to the width of the work implement, and In the above reference data, the width between the straight work paths or the width of the work implement is inversely proportional to the single brake pressure. Control method for an autonomous agricultural tractor.

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