Control method for work machines, control program for work machines, control system for work machines, and work system

Abstract

The present invention provides a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work system that facilitate the implementation of a lift limiting function that restricts the upward movement of the work machine according to the conditions in which the work machine is placed. [Solution] The control method for the work machine includes controlling a lifting device that raises and lowers the work machine attached to the machine body (S3, S4). The control method for the work machine also includes enabling a lift limiting function that limits the upward movement of the work machine when the height of the work machine reaches a lift limit value, provided that predetermined conditions are met (S1: Yes) (S2).

Description

Technical Field

[0001] The present invention relates to a control method for a work machine that raises and lowers a working implement, a control program for a work machine, a control system for a work machine, and a work system.

Background Art

[0002] As related art, a tractor in which a working implement is attached to the rear part of a tractor via a link mechanism so as to be freely raised and lowered is known (see, for example, Patent Document 1). The tractor according to the related art includes a lifting cylinder for driving a lift arm to raise the working implement, and a height regulation dial for setting an upper limit of the vertical swing range of the lift arm at an arbitrary position. In the tractor according to the related art, when the lift arm rises to the position set by the height regulation dial, the upward movement of the working implement by the lifting cylinder is automatically stopped.

[0003] Further, the tractor according to the related art includes an upper limit detection sensor that detects that the working implement has risen to a position close to the tractor. In the tractor according to the related art, the upward movement of the working implement by the lifting cylinder is also automatically stopped by the detection signal of the upper limit detection sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the aforementioned related technologies, whether the upward movement of the implement is stopped using the height restriction dial or the upper limit detection sensor, the upward limiting function that restricts the upward movement of the implement is always active. Therefore, even when the implement is moving outside the field or not in operation, the upward movement of the implement is restricted, which presents a problem as the operator may not be able to raise or lower the implement as desired.

[0006] The object of the present invention is to provide a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work system that facilitate the implementation of a lifting limit function that restricts the lifting movement of the work machine according to the conditions in which the work machine is placed. [Means for solving the problem]

[0007] A control method for a work machine according to one aspect of the present invention comprises controlling a lifting device that raises and lowers a work machine attached to the body of the work machine. The control method comprises, when predetermined conditions are met, enabling a lift limiting function that limits the upward movement of the work machine when the height of the work machine reaches a lift limit value.

[0008] A control program for a work machine according to one aspect of the present invention causes one or more processors to execute a control method for the work machine.

[0009] A control system for a work machine according to one aspect of the present invention comprises a work control unit and a suppression processing unit. The work control unit controls a lifting device that raises and lowers a work machine mounted on the body of the work machine. The suppression processing unit activates a lift limiting function that restricts the upward movement of the work machine when the height of the work machine reaches a lift limit value, provided that predetermined conditions are met.

[0010] A work system according to one aspect of the present invention comprises a control system for the work machine and the body of the work machine. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a control method for a work machine, a control program for a work machine, a control system for a work machine, and a work system that facilitate the implementation of a lifting limit function that restricts the lifting movement of the work machine according to the circumstances in which the work machine is placed. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic side view showing the external appearance of the work machine according to Embodiment 1. [Figure 2] Figure 2 is a schematic block diagram of the work system according to Embodiment 1. [Figure 3] Figure 3 is a schematic diagram illustrating the raising and lowering of the mounting portion by the lifting device of the work system according to Embodiment 1. [Figure 4] Figure 4 is a schematic diagram showing an example of a display screen in the work system according to Embodiment 1. [Figure 5] Figure 5 is a schematic diagram showing another example of the display screen in the work system according to Embodiment 1. [Figure 6] Figure 6 is a flowchart showing an example of a control method for a work machine according to Embodiment 1. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be described below with reference to the attached drawings. The following embodiments are examples that embody the present invention and are not intended to limit the technical scope of the present invention.

[0014] (Embodiment 1) [1] Overall structure First, the overall configuration of the work system 100 according to this embodiment will be described with reference to Figures 1 and 2. The control system 1 for the work machine according to this embodiment (hereinafter also simply referred to as "control system 1") constitutes the work system 100 together with the body 11 of the work machine 10. The work machine 12 is mounted on the body 11. In other words, the work system 100 comprises the control system 1 for the work machine and the body 11 of the work machine 10.

[0015] In this embodiment, the control system 1 includes a control device 2 (see FIG. 2) mounted on the machine body 11 of the working machine 10 and a terminal device 3. The working machine 10 and the terminal device 3 can communicate with each other. "Communicable" as referred to in the present disclosure means that information can be exchanged directly or indirectly via a communication network (network) or a repeater or the like by an appropriate communication method such as wired communication or wireless communication (communication using radio waves or light as a medium). The communication network includes, for example, the Internet, LAN (Local Area Network), WAN (Wide Area Network), public telephone line, mobile phone line network, packet line network, or wireless LAN. It is not an essential configuration in the control system 1 that the working machine 10 and the terminal device 3 can communicate with each other.

[0016] The working machine 10 includes a machine body 11. The machine body 11 is configured to be able to mount a working machine 12. The machine body 11 has an automatic traveling function.

[0017] The working machine 10 performs some work in the target area F1 (see FIG. 1) by the working machine 12 while moving in the target area F1. "Work" as referred to in the present disclosure is work performed by the working machine 12 on the target area F1, and includes, for example, various agricultural operations such as tilling, leveling, seeding, fertilizing, pesticide spraying, planting (paddy field planting), or harvesting, and various works such as construction work. In this embodiment, as an example, the work performed by the working machine 10 is assumed to be a tilling operation.

[0018] The working machine 12 performs work in the target area F1 when the machine body 11 of the working machine 10 moves in the target area F1. In this embodiment, as an example, the working machine 12 is assumed to be a tilling machine such as a rotary tiller or a plow that performs a tilling operation.

[0019] This type of working machine 12 includes a directly mounted working machine directly attached to the three-point link, and a trailed working machine towed by the machine body 11. In this embodiment, as an example, the working machine 12 is a directly mounted rotary tiller that is removably attached to the machine body 11 of the working machine 10. Here, the working machine 12 is attached to the rear side of the machine body 11 (the side opposite to the forward direction of the machine body 11). That is, the (directly mounted) working machine 12 is connected to the rear side of the machine body 11 and performs work while moving forward together with the machine body 11 when the machine body 11 moves forward. In this embodiment, although the working machine 12 is included in the components of the working machine 10, since the working machine 12 is removable from the machine body 11, it may not be included in the components of the working machine 10.

[0020] The "working machine" referred to in the present disclosure means a machine that performs various operations in a target area F1 such as a field. As an example, it is an agricultural machine (agricultural implement) such as a tractor, a seeding machine, a rice transplanter, a spraying machine, a mist blower, a transplanter, and a harvester. The working machine 10 may be, for example, a construction machine (construction implement). Further, the working machine 10 may be a machine without wheels such as an aircraft or a ship in addition to a vehicle.

[0021] In this embodiment, unless otherwise specified, the case where the working machine 10 is a tractor equipped with a rotary tiller as the working machine 12 will be described as an example. That is, the working machine 10 is constituted by connecting a (directly mounted) rotary tiller as the working machine 12 to a tractor as the machine body 11. In this working machine 10, by the machine body 11 traveling in a target area F such as a field, tilling work in the target area F1 becomes possible.

[0022] Thus, in this embodiment, the machine body 11 is a type of vehicle that moves by traveling in the target area F1. Here, as shown in FIG. 1, the machine body 11 includes a steering wheel 111 composed of a pair of left and right front wheels and a pair of drive wheels 112 composed of a pair of left and right rear wheels, and travels in the target area F1 with these four wheels (a pair of steering wheels 111 and a pair of drive wheels 112).

[0023] Furthermore, in this embodiment, as an example, the work machine 10 is an automated machine that can be operated by automatic driving (autonomous driving, etc.) while still being capable of carrying an operator. However, it is not limited to this, and the work machine 10 may be an unmanned machine that drives automatically, or it may be operated by an operator (including remote control).

[0024] In this disclosure, the "target area" refers to an area where the work machine 10 moves and performs various operations such as tilling, leveling, sowing, fertilizing, pesticide spraying, planting (rice planting), or harvesting, and includes paddy fields, dry fields, orchards, and pastures. For example, if the target area F1 is a paddy field or dry field where crops (agricultural products) such as rice, wheat, soybeans, or buckwheat are grown, the crops grown in the target area F1 are agricultural products. Furthermore, if trees are grown in a nursery, the nursery becomes the target area F1, and if trees that will become timber are grown in a forest, as in forestry, the forest becomes the target area F1. In this case, the crops grown in the target area F1 are trees or shrubs. In this embodiment, unless otherwise specified, the work machine 10 is used for tilling work in a field (target area F1), and the explanation will be given using the example that the target area F1 is a paddy field for growing rice.

[0025] Furthermore, the target area F1 is not limited to fields; for example, if the work machine 10 is a construction machine, then the site where the construction machine performs its work becomes the target area F1. Also, if the work machine 10 is an aircraft or a ship, then the target area F1 becomes the site where the aircraft or ship performs its work while navigating.

[0026] Furthermore, the work machine 10 can move automatically not only within the target area F1 (in this case, the field) but also on roads such as off-field routes outside the target area F1. Based on the position information of the work machine 10's current position, which is determined by the positioning device 15, the work machine 10 is configured to automatically travel (move) along pre-set target routes (including off-field routes) both within and outside the target area F1. Off-field routes are, for example, inter-field connecting roads that connect multiple target areas F1 (fields). Inter-field connecting roads may be farm roads, forest roads, public roads, private roads, or automobile roads, and may be roads exclusively for the work machine 10 or roads that are accessible to general vehicles (passenger cars, etc.).

[0027] Furthermore, the term "autonomous driving" as used in this disclosure includes "autonomous driving," in which the work machine 10 moves autonomously without operator intervention, and "semi-autonomous driving," in which only steering is automated, such as with straight-line assist.

[0028] "Autonomous driving" is a driving mode in which, for example, the steering wheels 111 are automatically steered, and the vehicle speed and other parameters are also automatically controlled, so that the work machine 10 travels along a target path. "Straight-line assist" is a driving mode in which, for example, the steering wheels 111 are automatically steered, and the vehicle speed and other parameters are controlled by the operator, so that the work machine 10 travels along a straight path parallel to a reference straight line (reference line). In other words, in "semi-automatic driving," the work machine 10 cannot move without operator operation, but the burden of steering is reduced for the operator, and it leads to improved work efficiency because it can travel along a target path such as a straight path. And in both autonomous driving and semi-automatic driving, the steering wheels 111 are automatically steered, so it can be said that this is a form of "automatic steering mode".

[0029] In automatic steering mode, the steering wheel 111 is automatically steered by an automatic steering mechanism including a steering motor. In other words, instead of the operator operating the steering control unit 41 (see Figure 1), automatic steering is achieved by changing the direction of the steering wheel 111 with the output of the steering motor. In short, the machine body 11 of the work machine 10 according to this embodiment has an automatic steering function that automatically steers the steering wheel 111.

[0030] In this embodiment, as an example, terminal device 3 is composed of a general-purpose terminal such as a tablet terminal, smartphone, or laptop computer. Terminal device 3, which is a general-purpose terminal, has dedicated application software (program) installed on it, and by starting this application software, terminal device 3 functions as terminal device 3 of control system 1.

[0031] [2] Configuration of the work machine Next, the configuration of the work machine 10 according to this embodiment will be described in detail with reference to Figures 1 and 2.

[0032] In this embodiment, for the sake of explanation, the vertical direction when the work machine 10 is in a usable state is defined as the up-down direction D1 (see Figure 1). The forward-backward direction D2 and left-right direction are defined based on the direction as seen from the driver (operator) sitting on the machine body 11 (operator's unit 5) of the work machine 10. The left side of the left-right direction refers to the left side when the machine body 11 is moving forward, and the right side of the left-right direction refers to the right side when the machine body 11 is moving forward. However, these directions are not intended to limit the direction of use (direction during use) of the work machine 10.

[0033] As shown in Figure 2, the work machine 10 includes a machine body 11 and a work machine 12, as well as a control device 2, a traveling device 13, a steering device 14, a positioning device 15, a detection device 16, a communication device 17, a power source 18, and a lifting device 6. The control device 2, traveling device 13, steering device 14, positioning device 15, detection device 16, communication device 17, power source 18, and lifting device 6 are all mounted on the machine body 11.

[0034] The machine body 11 has a control room 5 (see Figure 1) on which an operator can board. The control room 5 is equipped with a steering control unit 41, an operating lever 42, and pedals 43, etc., which are part of the steering system 14. The steering control unit 41, the operating lever 42, and the pedals 43, etc., are controls operated by the operator. Therefore, the work machine 10 is configured to be able to travel not only automatically but also manually by the operator.

[0035] A work implement coupling section 46, consisting of a three-point linkage mechanism, is provided at the rear of the machine body 11. A work implement 12 can be attached to the work implement coupling section 46. Power generated by the power source 18 can be transmitted to the towed work implement 12 via the transmission 44 and the power take-off shaft (PTO shaft) 7 (see Figure 3) located at the rear of the machine body 11. Here, since the work implement 12 is detachably connected to the work implement coupling section 46, it is also possible to connect a device other than the work implement 12 to the machine body 11.

[0036] In this embodiment, the implement 12 is a directly mounted rotary tiller, so tilling can be performed on the field, which is the target area F1, when the machine body 11 is moving forward. The relative position (relative height) of the implement 12 in the vertical direction D1 with respect to the machine body 11 is variable by the lifting device 6 (see Figure 3). As a result, the height of the implement 12 is variable when the field surface, which is the ground surface of the target area F1, is used as a reference. For example, by raising the implement 12 to a height away from the ground surface of the target area F1, the machine 10 can also travel in a non-working state when the implement 12 is not performing any work.

[0037] As shown in Figure 1, the running gear 13 is a device that drives the work machine 10 by driving the drive wheels 112, which consist of a pair of rear wheels (left and right). The running gear 13 includes a transmission 44 and transmits the power generated by the power source 18 to the drive wheels 112 via the transmission 44, thereby moving the machine body 11 forward or backward. Furthermore, the running gear 13 includes a brake device and can also decelerate or stop the machine body 11. In this embodiment, the drive wheels 112 are ordinary wheels, but it is not limited to this, and for example, a half-crawler type machine body 11 may be used in which crawlers (tracks) are used for the drive wheels 112. Alternatively, for example, a full-crawler type machine body 11 may be used in which the steering wheel 111 and the drive wheel 112 are combined into a single crawler, as will be described later.

[0038] As shown in Figure 1, the steering device 14 is a device that steers the steering wheels 111, which consist of a pair of front wheels (left and right). The steering device 14 includes a steering control unit 41 and steers the steering wheels 111 in accordance with the operator's operation of the steering control unit 41. The pair of steering wheels 111 have a reference posture in a plan view where they are facing in the front-rear direction D2, that is, a posture where the axis of rotation is aligned in the left-right direction, and the steering device 14 steers them so that they tilt to the left or right from the reference posture. In other words, the steering device 14 steers the steering wheels 111 by changing the orientation of the pair of steering wheels 111.

[0039] When the steering control unit 41 is operated clockwise from the position of the pair of steering wheels 111, the steering device 14 steers the pair of steering wheels 111 (front ends) to the right, causing the aircraft 11 to turn to the right when moving forward. On the other hand, when the steering control unit 41 is operated counterclockwise from the position of the pair of steering wheels 111, the steering device 14 steers the pair of steering wheels 111 (front ends) to the left, causing the aircraft 11 to turn to the left when moving forward. In this embodiment, the operator operates the steering control unit 41 during manual steering, but this is not limited to this, and manual steering may be performed by the operator operating, for example, an operating lever.

[0040] With the running gear 13 and steering gear 14, the aircraft 11 can move within the target area F1 in the longitudinal direction D2 and the lateral direction. For example, when the driving wheels 112 are driven by the running gear 13 and the aircraft 11 is moving forward, if the angle of the steering wheels 111 is changed by the steering gear 14, the aircraft 11 will turn in the lateral direction and the direction of travel of the aircraft 11 will be changed.

[0041] The positioning device 15 determines the current position (latitude, longitude, and altitude, etc.) of the aircraft 11. Specifically, the positioning device 15 is, for example, positioned on the LOPS frame 113 and calculates the current position (latitude and longitude) of the aircraft 11 using a satellite positioning system such as GNSS (Global Navigation Satellite System). In other words, the positioning device 15 has a positioning antenna that receives positioning signals from multiple satellites and calculates the current position based on the positioning signals. Furthermore, the positioning device 15 includes an inertial sensor and can also detect the attitude of the aircraft 11, such as its current bearing.

[0042] Furthermore, the positioning device 15 employs a relatively high-precision positioning method, such as RTK (Real Time Kinematic) positioning, which calculates the current position of the work machine 10 by utilizing correction information corresponding to a base station (reference station) close to the work machine 10. The current position of the aircraft 11 may be the same as the positioning position (position of the positioning antenna), or it may be a position shifted from the positioning position, such as the center position of the aircraft 11 in a plan view. For example, a mobile phone terminal, smartphone, tablet terminal, or quantum compass may be used as the positioning device 15.

[0043] The detection device 16 detects obstacles in the detection area. The detection device 16 includes an obstacle sensor and a detection processing unit. The obstacle sensor may include various sensors such as a camera (image sensor), sonar sensor, human presence sensor, radar, or LiDAR (Light Detection and Ranging). The obstacle sensor may be a 3D sensor that measures the distance to an object (obstacle) using the TOF (Time Of Flight) method, which measures the distance to the distance measurement point based on the round-trip time it takes for light or sound to reach the distance measurement point and return. The detection processing unit detects obstacles based on the measurement information obtained from the obstacle sensor. Here, the detection processing unit may only detect the presence or absence of obstacles, or it may detect the position, shape, number, or attributes (including type, etc.) of the obstacles.

[0044] The detection results from the detection device 16 are output to the control device 2. When the detection device 16 detects an obstacle during the automatic driving of the work machine 10, the control device 2 outputs an alarm (including notification by sound and / or light) and performs obstacle avoidance processing (including detour, deceleration, or stopping) by controlling the driving device 13 and steering device 14. Furthermore, the control device 2 may output the location information of the obstacle and the execution history of the avoidance processing to the terminal device 3 and display it on the terminal device 3.

[0045] The communication device 17 is a communication interface for connecting the work machine 10 (control device 2 and positioning device 15, etc.) to an external device by wire or wireless connection, and for performing data communication with the external device in accordance with a predetermined communication protocol. In this embodiment, the communication device 17 is capable of communicating with at least the external device, which is the terminal device 3. For example, a mobile phone terminal, smartphone, or tablet terminal may be used as the communication device 17.

[0046] The power source 18 is a drive source that supplies power to at least the running gear 13. The power source 18 is located at the front of the machine body 11, covered by a bonnet 45. The power source 18 is the drive source for the work machine 10, and is, for example, a diesel engine. However, the power source 18 of the work machine 10 is not limited to a diesel engine, but may be an engine such as a gasoline engine, an electric motor, or a hybrid system of an engine and an electric motor.

[0047] Furthermore, the power source 18 drives a hydraulic pump, which supplies hydraulic fluid to the hydraulic cylinders and other components of the power steering mechanism of the steering device 14. In other words, the power source 18 is configured to also supply power to the power steering mechanism.

[0048] The transmission 44 is located behind the power source 18 and below the driver's compartment 5. The transmission 44 includes a power transmission device. The rotational power of the power source 18 is transmitted to at least one of the steering wheels 111 and the drive wheels 112 (in this embodiment, the drive wheels 112) via the power transmission device in the transmission 44.

[0049] The driver's unit 5 is located behind the power source 18 in the aircraft body 11. The driver's unit 5 includes a driver's seat and a dashboard 52, etc. The driver's seat is where the driver sits. The dashboard 52 also serves as the steering column and is located in front of the driver's seat.

[0050] The steering control unit 41 is, for example, a steering wheel operated by a driver seated in the driver's seat. The steering control unit 41 is rotatably supported by a steering shaft located within the dashboard 52. The steering control unit 41 is located in front of the driver's seat and above the dashboard 52. The aircraft 11 can change the direction (steering angle) of the steering wheels 111 by rotating the steering control unit 41.

[0051] In addition, the driver's unit 5 is equipped with, for example, operating levers 42 and pedals 43 operated by the driver, and a meter that indicates the speed of the work machine 10. The operating levers 42 may include multiple types of levers, such as a main gear lever, a sub-gear lever, a work lever for driving the work machine 12, or a lifting lever for raising and lowering the work machine 12. The pedals 43 may also include multiple types of pedals, such as an accelerator pedal and a brake pedal.

[0052] In this embodiment, the work machine 10 is equipped with a rops frame 113 at the rear of the driver's seat. The rops frame 113 protects the driver in the event that the work machine 10 tips over. The work machine 10 is not limited to a rops specification equipped with a rops frame 113, but may also be a cabin specification in which the driver's seat is covered by a cabin.

[0053] The control device 2 primarily consists of a computer system having one or more processors such as a CPU (Central Processing Unit) and one or more memories such as ROM (Read Only Memory) and RAM (Random Access Memory), and performs various processes (information processing). In this embodiment, since the control device 2 primarily consists of a computer system having one or more processors, the control device 2 is realized when one or more processors execute a control program for the work machine. In this embodiment, the control device 2 is an integrated controller that controls the entire work machine 10, and consists of, for example, an electronic control unit (ECU). However, the control device 2 may be provided separately from the integrated controller.

[0054] The control device 2 is configured to communicate with devices provided in various parts of the machine body 11. In other words, the control device 2 is electrically connected to the work equipment 12, the travel equipment 13, the steering equipment 14, the positioning device 15, the detection device 16, the communication device 17, the power source 18, and the lifting device 6, etc. As a result, the control device 2 can control the work equipment 12, the travel equipment 13, the steering equipment 14, and the lifting device 6, etc., and acquire the outputs of the positioning device 15 and the detection device 16, etc. Here, the control device 2 may exchange various types of information (data) directly with each device, or it may do so indirectly via a relay or the like.

[0055] In this embodiment, the control device 2, as shown in Figure 2, includes a driving control unit 21, a steering control unit 22, a work control unit 23, and a storage unit 24.

[0056] The driving control unit 21 controls the driving device 13 and the power source 18. At least during autonomous driving, the driving control unit 21 controls the driving device 13 and the power source 18 to bring the vehicle speed, engine speed, etc., closer to target values, on behalf of the operator. The driving control unit 21 can also control the brake device of the driving device 13 to decelerate or stop the machine 11.

[0057] The steering control unit 22 controls the steering device 14. The steering control unit 22 has two operating modes: an automatic steering mode and a manual steering mode, and is configured to be switchable between the automatic steering mode and the manual steering mode. The manual steering mode is a mode in which the operator performs steering by operating the steering control unit 41. At least during autonomous or semi-autonomous driving, the steering control unit 22 operates in automatic steering mode and controls the steering device 14 to bring the steering angle of the steering wheels 111 closer to the target steering angle, on behalf of the operator.

[0058] In particular, during autonomous driving, the steering control unit 22, together with the driving control unit 21, controls the work machine 10 based on the current position of the machine body 11 so that the machine body 11 travels along the target path. The target path for autonomous driving of the work machine 10 is generated, for example, in the terminal device 3. That is, the work machine 10 obtains path data corresponding to the target path from the terminal device 3 and performs autonomous driving according to the target path.

[0059] The work control unit 23 controls the lifting device 6 that raises and lowers the work implement 12 attached to the body 11 of the work machine 10, and the work implement 12 itself. At least during autonomous driving, the work control unit 23 controls the work implement 12 based on the current position of the body 11 on the target path. Specifically, if the work machine 10 is traveling along a work path on the target path in which work is to be performed by the work implement 12, the work control unit 23 controls the lifting device 6 to lower the work implement 12 to the work position and perform work with the work implement 12. On the other hand, if the work machine 10 is traveling along a non-work path on the target path in which work is not to be performed by the work implement 12, the work control unit 23 controls the lifting device 6 to raise the work implement 12 to the non-work position and stop work with the work implement 12.

[0060] Furthermore, the work control unit 23 also controls the work implement 12 in response to the operator's actions, even when the machine is manually operated. Specifically, when the work implement 10 approaches the work path, the operator lowers the work implement 12. The work control unit 23 then controls the lifting device 6 in response to this operation, lowering the work implement 12 and setting it in the work position. On the other hand, when the work implement 10 approaches a non-work path, the operator raises the work implement 12. The work control unit 23 then controls the lifting device 6 in response to this operation, raising the work implement 12 to the non-work position.

[0061] The memory unit 24 is a non-volatile memory that stores various data such as control programs for the work machine and target path information related to the target path. In other words, the driving control unit 21 and the steering control unit 22 can, for example, perform autonomous driving along the target path based on the target path information stored in the memory unit 24. The memory unit 24 also stores the lift limit value that is referenced in the lift limit function described later.

[0062] In addition to the above-described configuration, the work machine 10 is further equipped with a battery, fuel tank, and various sensors. The battery supplies power for operation to various parts of the work machine 10, such as the control device 2. In particular, electronic devices such as the control device 2, steering device 14, positioning device 15, detection device 16, and communication device 17 can operate even when the power source 18 is stopped, as they are powered by the battery.

[0063] [3] Configuration of terminal device Next, the configuration of the terminal device 3 according to this embodiment will be described in detail with reference to Figures 1 and 2.

[0064] In this embodiment, the terminal device 3 is capable of communicating with the work machine 10 as described above, and together with the control device 2 of the work machine 10, constitutes the control system 1. In other words, the components of the control system 1 are distributed and provided in at least the work machine 10 and the terminal device 3. However, the configuration is not limited to this, and for example, the functions of the control device 2 may be provided in the terminal device 3, in which case the components of the control system 1 will be realized by the terminal device 3 alone.

[0065] In this embodiment, as an example, the terminal device 3 is composed of a general-purpose terminal such as a tablet terminal, smartphone, or laptop computer. The terminal device 3 is positioned in a location easily visible to the operator, such as the operating unit 5 of the work machine 10. As shown in Figure 2, the terminal device 3 includes an information processing unit 31, a display unit 32, an operation unit 33, and a communication unit 34. Furthermore, the terminal device 3 also includes a sound output unit that outputs sound (including voice) to the user (operator), and a battery, etc.

[0066] The information processing unit 31 primarily consists of a computer system having one or more processors such as a CPU and one or more memories such as ROM and RAM, and performs various processes (information processing). In this embodiment, since the information processing unit 31 primarily consists of a computer system having one or more processors, the information processing unit 31 is realized when one or more processors execute a control program for the work machine. In other words, the control system 1 is realized through the cooperation of the control device 2 and the terminal device 3, as one or more processors of the control device 2 included in the control system 1 and one or more processors of the information processing unit 31 each execute a control program for the work machine.

[0067] The information processing unit 31 is configured to communicate with each part of the terminal device 3 (display unit 32, operation unit 33, and communication unit 34). In other words, the information processing unit 31 is electrically connected to the display unit 32, operation unit 33, and communication unit 34, etc. This allows the information processing unit 31 to control the display of the display unit 32 and to acquire operation inputs for the operation unit 33. Here, the information processing unit 31 may exchange various types of information (data) directly with each part, or indirectly via a relay or the like.

[0068] Such a terminal device 3 is a user interface for receiving operation input from a user (operator) and outputting various information to the user. For example, the terminal device 3 outputs various information to the user by displaying various screens on the display unit 32. Furthermore, the terminal device 3 accepts various operations from the user by outputting electrical signals corresponding to the user's operations on the operation unit 33. In this disclosure, "screen" means the image (video) displayed on the display unit 32, etc., of the terminal device 3, and includes illustrations, figures, photographs, text, and videos. The screens displayed on the terminal device 3 include not only still images but also images (videos) that change moment by moment.

[0069] The display unit 32 is a user interface equipped with a display device such as a liquid crystal display or an organic EL display that displays various types of information. The display unit 32 displays the progress of work in the target area F1, as well as the operating status of the work machine 10, including the target path of the work machine 10, the (actual) movement trajectory, the current position and movement speed, thereby enabling remote monitoring of the work machine 10 during automated operation by the operator.

[0070] The control unit 33 is a user interface equipped with input means such as a touch panel, mouse, keyboard, mechanical switch, or encoder for receiving operations. The control unit 33 can receive instructions from the operator to start or stop the automatic movement of the work machine 10. The terminal device 3 can remotely control the work machine 10 by transmitting these start or stop instructions to the work machine 10. Therefore, the operator can remotely control the work machine 10.

[0071] In this embodiment, as an example, the display unit 32 and the operation unit 33 are integrated and constitute a touch panel display. The operator can set (register) various information by operating the operation unit 33 on the operation screen displayed on the display unit 32. This allows, for example, the operator to set automatic driving information (including target route information) related to the automatic driving of the work machine 10 using the terminal device 3.

[0072] The communication unit 34 is a communication interface for connecting the terminal device 3 to the work machine 10 by wire or wireless connection and for performing data communication with the work machine 10 in accordance with a predetermined communication protocol. In this embodiment, the communication unit 34 can communicate with at least the work machine 10 (its communication device 17) via a communication network. Furthermore, since the communication unit 34 can connect to the communication network at least wirelessly, it is possible to communicate with the work machine 10 at any time, even when the communication unit 34 is located at a sufficiently distant location from the work machine 10.

[0073] In this embodiment, the information processing unit 31 includes a suppression processing unit 311 and a storage unit 312, as shown in Figure 2. In addition to the suppression processing unit 311, the information processing unit 31 also includes, for example, a generation processing unit, an execution processing unit, and a display processing unit. The generation processing unit performs the process of generating a target path for the work machine 10 to automatically travel in the target area F1. The execution processing unit performs the process of causing the work machine 10 to execute specific operations, such as operations related to the automatic travel of the work machine 10. The display processing unit performs the process of displaying various information on the display unit 32.

[0074] In this embodiment, as an example, the information processing unit 31 mainly consists of a computer system having one or more processors, so these multiple functional units (suppression processing unit 311, etc.) are realized by one or more processors executing a control program for a work machine. These multiple functional units included in the information processing unit 31 may be distributed across multiple housings or may be provided in a single housing.

[0075] The memory unit 312 is a non-volatile memory that stores various data such as control programs for work machines and target path information related to target paths. Furthermore, the memory unit 312 can store various data such as work machine information, work machine information, PTO shaft information, field information, and work information. Work machine information is information about work machines 12 attached to the machine body 11, and includes information such as the type of work machine 12, identification information, model name, model number, and size (dimensions). Work machine information is information about the machine body 11 (vehicle body) of the work machine 10, and includes information such as the type of machine body 11 (e.g., full crawler type / half crawler type / wheel type, etc.), identification information, model name, model number, and size (dimensions). In addition, PTO shaft information is information about the PTO shaft 7 provided on the machine body 11, and includes information such as the type of PTO shaft 7, identification information, shaft name, rated rotational speed, load capacity, model number, and size (dimensions). Field information refers to information about the field designated as the target area F1, and includes information such as field identification information, field name, location, shape, size, work start position (travel start position) where work begins, work end position (travel end position) where work ends, and work direction. Work information refers to information about the work performed by the work machine 10, and includes information such as the type of work and how the work will be performed in detail. Furthermore, information such as whether or not coordinated work will be performed by the work machine 10, the width of the headland, and the width of the uncultivated land may also be included in the work information.

[0076] The information stored in the memory unit 312 (target route information, implement information, work machine information, field information, and work information, etc.) is set (registered) by user (operator) input to the operation unit 33 or by acquisition from the work machine 10. For example, the type of implement 12 in the implement information may be specified by the user by operating the operation unit 33, or the work machine 10 may automatically identify the implement 12 attached to the machine body 11 and transmit it to the terminal device 3. The terminal device 3 may also acquire this information from external devices other than the work machine 10 (e.g., a server, external storage medium, or other terminal device).

[0077] The suppression processing unit 311 performs the process of enabling the rise limit function described later in "[5.1] Rise Limit Function" when predetermined conditions are met. The suppression processing unit 311 will be explained in detail later in "[5.2] Suppression Function".

[0078] Terminal device 3 may be able to access the website (agricultural support site) of the agricultural support service provided by the server via a communication network. In this case, terminal device 3 can function as an operating terminal for the server by having a browser program executed by the information processing unit 31. The server then has the above-mentioned processing units and executes each of them.

[0079] [4] Configuration of the lifting device Next, the configuration of the work equipment connecting section 46, along with the configuration of the lifting device 6 for raising and lowering the work equipment 12, will be explained in detail using Figures 1 and 3. As shown in Figures 1 and 3, the work equipment connecting section 46 comprises one top link 461, a pair of lower links 462 (only one side is shown in Figures 1 and 3) located below the top link 461, and a mounting section 463 to which the work equipment 12 can be attached.

[0080] The top link 461 is located in the center of the width direction of the machine body 11 when viewed from the rear to the front of the machine body 11. The pair of lower links 462 are located on either side of the top link 461 when viewed from the rear to the front of the machine body 11, and are located below the top link 461. In other words, the top link 461 and the pair of lower links 462 are arranged to form a triangle when viewed from the rear to the front of the machine body 11, and support the work implement 12 attached to the mounting section 463 at three points.

[0081] Furthermore, each of the pair of lower links 462 has its first end (in this case, the front end) fixed to the machine body 11, and is configured to rotate clockwise or counterclockwise when viewed from the left or right direction, with respect to the fixed first end as the axis. Therefore, as the pair of lower links 462 rotate, the relative position (relative height) of the work implement 12 attached to the mounting part 463 in the vertical direction D1 relative to the machine body 11 becomes variable. Specifically, when the pair of lower links 462 rotate in the first direction (counterclockwise in Figure 1), the work implement 12 rises. Conversely, when the pair of lower links 462 rotate in the second direction (clockwise in Figure 1), the work implement 12 descends.

[0082] The mounting portion 463 is, for example, a fastener (hitch) for attaching the work implement 12, and is attached to one end of the top link 461 and to one end of each of the pair of lower links 462. Note that the mounting portion 463 is not limited to a fastener, and may consist of one end of the top link 461 and one end of each of the pair of lower links 462. In this case, the work implement 12 is directly attached to one end of the top link 461 and to one end of each of the pair of lower links 462.

[0083] As shown in Figure 3, the lifting device 6 comprises a pair of left and right lift arms 61 (only one side is shown in Figure 3), a pair of left and right lift rods 62 (only one side is shown in Figure 3), and a pair of left and right hydraulic cylinders 63 (only one side is shown in Figure 3). The lifting device 6 also comprises a pair of left and right angle sensors 64 (only one side is shown in Figure 3).

[0084] Each of the pair of lift arms 61 has its first end (in this case, the front end) fixed to the machine body 11, and is configured to rotate clockwise or counterclockwise when viewed from the left or right direction, with respect to the fixed first end as the axis. The first end (in this case, the upper end) of each of the pair of lift arms 61 is fixed to the second end (in this case, the rear end) of each of the pair of lift rods 62. The second end (in this case, the lower end) of each of the pair of lift rods 62 is fixed to the middle part of a pair of lower links 462.

[0085] Each of the pair of hydraulic cylinders 63 has its first end (in this case, the lower end) fixed to the machine body 11, and its second end (in this case, the upper end) fixed to the middle part of the pair of lift arms 61. The lifting device 6 raises and lowers the work equipment 12 by extending and retracting the pair of hydraulic cylinders 63 in response to the operation of the lifting lever located in the driver's unit 5, or in response to the lifting operation of the work equipment 12 in the terminal device 3.

[0086] Specifically, when an operation to raise the work implement 12 is received, the pair of hydraulic cylinders 63 extend upward, causing the pair of lift arms 61 to rotate in a first direction (counterclockwise in Figure 3). As the pair of lift arms 61 rotate in the first direction, the pair of lift rods 62 move upward in conjunction with the rotation of the pair of lift arms 61. Then, as the pair of lift rods 62 move upward, the pair of lower links 462 rotate in the first direction. As a result, the mounting portion 463 rises in conjunction with the rotation of the pair of lower links 462 in the first direction, and the work implement 12 attached to the mounting portion 463 rises.

[0087] Furthermore, when the system receives a command to lower the work implement 12, the pair of hydraulic cylinders 63 retract downwards, causing the pair of lift arms 61 to rotate in a second direction (clockwise in Figure 3). As the pair of lift arms 61 rotate in the second direction, the pair of lift rods 62 move downward in conjunction with the rotation of the lift arms 61. As the pair of lift rods 62 move downward, the pair of lower links 462 rotate in the second direction. As a result of the rotation of the pair of lower links 462 in the second direction, the mounting portion 463 descends, and the work implement 12 attached to the mounting portion 463 descends.

[0088] Each of the pair of angle sensors 64 is either a potentiometer or an encoder, and is mounted on the axis of each of the pair of lift arms 61. Each of the pair of angle sensors 64 detects the rotation angle α of the corresponding lift arm 61. The detection result of each of the pair of angle sensors 64 is referenced in the lifting and lowering control of the work equipment 12 by the lifting device 6. Specifically, the lifting device 6 controls the extension and retraction of the pair of hydraulic cylinders 63 so that the detection results of each of the pair of angle sensors 64 approach the same value. This allows the lifting device 6 to raise and lower the work equipment 12 while maintaining balance in the width direction (in this case, the left-right direction).

[0089] [5] Control method for working machinery The following describes an example of a control method (hereinafter simply referred to as "control method") for the work machine 10, which is mainly performed by the control system 1 (control device 2 and terminal device 3), with reference to Figures 3 to 6.

[0090] The control method according to this embodiment is executed by a control system 1, which mainly consists of a computer system; in other words, it is implemented by a control program for work vehicles (hereinafter simply referred to as the "control program"). That is, the control program according to this embodiment is a computer program that causes one or more processors to execute each process related to the control method.

[0091] Here, the control system 1 executes the following various processes related to the control method when a specific pre-set start operation is performed to run the control program. The start operation is, for example, the operation to start the application program (control program for work vehicles) on the terminal device 3. On the other hand, the control system 1 terminates the following various processes related to the control method when a specific pre-set end operation is performed. The end operation is, for example, the operation to terminate the application program (control program for work vehicles) on the terminal device 3.

[0092] [5.1] Upper limit function First, the lift limiting function performed by the control system 1 according to this embodiment will be explained with reference to Figures 1 and 3. The lift limiting function is a process that stops the lifting of the work implement 12 when its height reaches a preset lift limit value. In this embodiment, the height of the work implement 12 is defined by the rotation angle α of each of the pair of lift arms 61. Specifically, with the rotation angle α at the initial position (lowest position) of the pair of lift arms 61 set to zero, the larger the rotation angle α, the higher the height of the work implement 12, and the smaller the rotation angle α, the lower the height of the work implement 12.

[0093] In this embodiment, the height of the work machine 12 in the terminal device 3 is represented by the height of each of the pair of lift arms 61 (referred to as "lift height" in Figures 4 and 5), as shown in Figures 4 and 5. "Lift height" is expressed as a percentage, with the initial position (lowest position) of each of the pair of lift arms 61 being 0% and the position when rotated to the upper limit of the allowable rotation angle α being 100%. Alternatively, "lift height" may be expressed as the value of the rotation angle α of each of the pair of lift arms 61.

[0094] In this embodiment, the lift limit is defined by the rotation angle α of each of the pair of lift arms 61. Therefore, when the rotation angle α of each of the pair of lift arms 61 reaches a preset rotation angle (lift limit), the lifting device 6 restricts (prohibits) further extension of the pair of hydraulic cylinders 63, thereby limiting the lifting of the work machine 12 further. The rotation angle α of each of the pair of lift arms 61 is detected by a pair of angle sensors 64.

[0095] In this embodiment, the lift limit value in the terminal device 3 is represented by the height of each of the pair of lift arms 61 (referred to as "lift height (lift limit)" in Figures 4 and 5), as shown in Figures 4 and 5. "Lift height (lift limit)" is expressed as a percentage, with the initial position (lowest position) of each of the pair of lift arms 61 being 0% and the position when rotated to the upper limit of the allowable rotation angle α being 100%. Alternatively, "lift height (lift limit)" may be expressed as the value of the rotation angle α of each of the pair of lift arms 61.

[0096] Here, we will explain the reason for performing the lift limiting function. In order to drive the work implement 12, as shown in Figure 3, the PTO shaft 7, which is a drive shaft located at the rear of the machine body 11, and the driven shaft 9 located on the work implement 12 are connected by a transmission device 8. The transmission device 8 drives the driven shaft 9 by transmitting the rotation of the PTO shaft 7, which is driven by the power generated by the power source 18, to the driven shaft 9. In this way, it is possible to drive the work implement 12 by driving the PTO shaft 7.

[0097] The transmission device 8 includes a first universal joint 81, a second universal joint 82, and an intermediate shaft 83. Both the first universal joint 81 and the second universal joint 82 are universal joints. The first universal joint 81 is connected to one end (in this case, the rear end) of the PTO shaft 7 and to the first end (in this case, the front end) of the intermediate shaft 83. The second universal joint 82 is connected to the second end (in this case, the rear end) of the intermediate shaft 83 and to one end (in this case, the front end) of the driven shaft 9. The intermediate shaft 83 transmits the rotation of the first universal joint 81, which occurs with the rotation of the PTO shaft 7, to the second universal joint 82. As a result, the driven shaft 9 rotates with the rotation of the second universal joint 82, and the power generated by the power source 18 is transmitted to the work implement 12.

[0098] The transmission device 8 changes position as the work implement 12 is raised and lowered. Specifically, the intermediate shaft 83 of the transmission device 8 rotates clockwise or counterclockwise as the work implement 12 is raised and lowered, when viewed from the left and right directions, around the connection point between the PTO shaft 7 and the first universal joint 81. Hereinafter, the angle between the axial direction (front-back direction D2) of the PTO shaft 7 and the axial direction of the intermediate shaft 83, when viewed from the left and right directions, will be referred to as the swing angle of the universal joint (hereinafter simply "swing angle β"). In the example shown in Figure 3, as shown in <Initial position (lowest position)>, when the rotation angle α of each of the pair of lift arms 61 is zero, the swing angle β is also zero. On the other hand, as shown in <When raised>, as the rotation angle α of each of the pair of lift arms 61 increases, the swing angle β also increases. Thus, there is a positive correlation between the rotation angle α of each of the pair of lift arms 61, that is, the height of the work implement 12, and the swing angle β.

[0099] Here, if raising the work implement 12 causes the swing angle β to exceed the allowable upper limit, an excessive load will be placed on the PTO shaft 7 via the transmission device 8, potentially causing the PTO shaft 7 to bend or malfunction. For this reason, the work implement 10 performs a lift limiting function to prevent the swing angle β from exceeding the allowable angle. In other words, when the height of the work implement 12 reaches the lift limit value, further raising of the work implement 12 may cause the swing angle β to exceed the allowable angle, so the lifting of the work implement 12 is limited. This prevents excessive load from being placed on the PTO shaft 7 as the work implement 12 rises.

[0100] Incidentally, according to the related technology described above, in the work machine 10, when an operator sets a lift limit value using a height control dial that sets the rotation angle α of each of the pair of lift arms 61 to an arbitrary value, the upper limit limit processing becomes effective. Furthermore, according to the related technology described above, in the work machine 10, the upper limit limit processing becomes effective using the detection result of an upper limit detection sensor that detects when the work machine 12 has risen and reached a position close to the machine body 11.

[0101] However, whether the height restriction function is enabled using the height restriction dial or the upper limit detection sensor, the height restriction function is always active. As a result, even when the work machine 10 is moving outside the field or not working, the upward movement of the work machine 12 is restricted, which presents a problem in that the operator may not be able to raise or lower the work machine 12 as desired.

[0102] In this embodiment, a control method, a control program for a work machine, a control system 1 for a work machine, and a work system 100 are realized that make it easy to implement a lifting limit function that restricts the lifting movement of the work machine 12 according to the situation in which the work machine 12 is placed, through the "suppression function" described below.

[0103] [5.2] Suppression function Next, the suppression function in the control method according to this embodiment will be described with reference to Figures 4 to 6. The suppression function is a function that enables the rise limiting function when predetermined conditions are met. Specifically, the suppression processing unit 311 disables the rise limiting function until the predetermined conditions are met, and enables the rise limiting function thereafter. Furthermore, even if the state transitions from one where the predetermined conditions are met to one where they are not, the suppression processing unit 311 disables the rise limiting function until the predetermined conditions are met again.

[0104] Therefore, the control method according to this embodiment has the advantage that the lift limiting function is easily executed depending on the situation in which the work machine 10 is placed, as the lift limiting function is enabled only when predetermined conditions are met and disabled when the predetermined conditions are not met. Specifically, for example, the lift limiting function can be enabled while the work machine 10 is performing work using the work implement 12, and disabled when the work machine 10 is not performing work using the work implement 12. In this case, since there is no restriction on the upward movement of the work implement 12 when it is not working, the operator can raise and lower the work implement 12 as desired.

[0105] Here, the predetermined conditions may include, for example, drive conditions relating to the driving state of the PTO shaft 7 that transmits the power generated by the power source 18 to the work implement 12. The drive conditions include, for example, that the PTO shaft 7 is being driven. Specifically, if the predetermined condition is that the PTO shaft 7 is being driven, the suppression processing unit 311 enables the lift limiting function when the driving of the PTO shaft 7 starts, and disables the lift limiting function when the driving of the PTO shaft 7 stops. In other words, in this case, the suppression processing unit 311 enables the lift limiting function only while the PTO shaft 7 is being driven.

[0106] Furthermore, the driving conditions include, for example, the start of driving of the PTO shaft 7. Specifically, if the predetermined condition is the start of driving of the PTO shaft 7, the suppression processing unit 311 activates the lift limiting function when the driving of the PTO shaft 7 starts, and maintains the active state of the lift limiting function until, for example, the power to the work machine 10 is turned off. In other words, in this case, the suppression processing unit 311 activates the lift limiting function once the PTO shaft 7 is driven, and keeps the lift limiting function active even if the PTO shaft 7 stops until the power to the work machine 10 is turned off.

[0107] Furthermore, the predetermined conditions may include positional conditions relating to the location of the work machine 10. The positional conditions include, for example, that the current position of the work machine 10, as determined by the positioning device 15, is within the target area F1 (in this case, the field). Specifically, if the predetermined condition is that the current position of the work machine 10 is within the target area F1, the suppression processing unit 311 activates the rise limiting function when the work machine 10 enters the target area F1, and deactivates the rise limiting function when the work machine 10 leaves the target area F1. In other words, in this case, the suppression processing unit 311 activates the rise limiting function only when the work machine 10 is within the target area F1, or in other words, when the work machine 10 is working.

[0108] Furthermore, the predetermined conditions may include a switch in the operating mode from manual steering mode to automatic steering mode. Specifically, while the operating mode is manual steering mode, the suppression processing unit 311 disables the rise limit function. Then, when the steering control unit 22 switches the operating mode from manual steering mode to automatic steering mode, the suppression processing unit 11 enables the rise limit function. In other words, in this case, the suppression processing unit 311 enables the rise limit function only when the operating mode is automatic steering mode.

[0109] In this embodiment, the suppression processing unit 311 further has the capability to automatically set the rise limit value used in the rise limit function without operator intervention. Specifically, the rise limit value is set in advance, for example, during the manufacturing of the work machine 10, and stored in the storage unit 312. When the suppression processing unit 311 enables the rise limit function, it reads the rise limit value stored in the storage unit 312 and references the rise limit value in the rise limit function. This has the advantage of preventing operators from forgetting to set the rise limit value, as they do not have to manually set it themselves.

[0110] As already mentioned, there is a positive correlation between the rotation angle α of each of the pair of lift arms 61, that is, the height of the work machine 12, and the swing angle β. However, the rotation angle α and the swing angle β are not always the same. For example, in the example shown in Figure 3, as shown in <initial position (lowest position)>, both the rotation angle α and the swing angle β are zero degrees, but it is also possible that the swing angle β is greater than the rotation angle α. Also, for example, if the rotation angle α is 30 degrees, the swing angle β may be less than 30 degrees or greater than 30 degrees. Furthermore, for example, if there is an increase or decrease of a predetermined angle in the rotation angle α, the increase or decrease in the swing angle β may be greater than or less than the predetermined angle. The correlation between the rotation angle α and the swing angle β may vary depending on the specifications of the PTO shaft 7, the work machine 10, or the work machine 12.

[0111] Therefore, if the operator were to set the lift limit value, the correlation between the rotation angle α and the swing angle β would be unknown, and the operator would have to set a lift limit value that does not place an excessive load on the PTO shaft 7, based on their experience. To solve the above problem, the lift limit value may be set automatically as follows. The process of setting the lift limit value is executed, for example, when the work machine 10 is started for the first time. The lift limit function is then executed by referring to the set lift limit value. In other words, the process of setting the lift limit value basically only needs to be executed once. If there is a change in the information referenced when setting the lift limit value, the lift limit value may be updated by executing the process of setting the lift limit value again.

[0112] For example, the height of the work implement 12 has a defined range of settings that can be set as a lift limit value, and the initial value of the lift limit value may be set to the lower limit of that setting range. Specifically, the lift limit value has a defined range of settings that can be set, and it is possible to set it to any value within that setting range. In this case, the initial value of the lift limit value is automatically set to the lower limit of that setting range. For example, if the setting range of the lift limit value is 20% to 80% as expressed by the "lift height" already mentioned, the initial value of the lift limit value will be automatically set to the lower limit of 20%. Setting the initial value of the lift limit value to the lower limit of the setting range in this way has the advantage that the lift limit function is more likely to be executed before excessive load is placed on the PTO shaft 7, regardless of the specifications of the PTO shaft 7.

[0113] For example, if the initial value of the upward limit is set to a relatively large value such as 50%, depending on the specifications of the PTO shaft 7, an excessive load may be placed on the PTO shaft 7 when it is driven, and the upward limit function may not be fully effective. In contrast, if the initial value of the upward limit is set to the lower limit of the set range, the possibility of an excessive load being placed on the PTO shaft 7 when it is driven is reduced.

[0114] Furthermore, for example, the lift limit may be automatically set based on information relating to at least one of the PTO shaft 7, the work machine 10, and the work machine 12. In particular, the lift limit may be automatically set based on information relating to the allowable angle of the swing angle β of the universal joint (here, the first universal joint 81).

[0115] Here, the information relating to the PTO shaft 7 is, for example, PTO shaft information stored in the memory unit 312, and includes information such as the type of PTO shaft 7, identification information, shaft name, rated rotational speed, load capacity, model, and size (dimensions). The information relating to the work machine 10 is, for example, work machine information stored in the memory unit 312, and includes information such as the type of machine body 11 (e.g., full crawler type / half crawler type / wheel type, etc.), identification information, model name, model, and size (dimensions). The information relating to the work machine 12 is, for example, work machine information stored in the memory unit 312, and includes information such as the type of work machine 12, identification information, model name, model, and size (dimensions).

[0116] Other information regarding the PTO shaft 7 may include, for example, the position where the first universal joint 81 is attached to the PTO shaft 7, and the position where the second universal joint 82 is attached to the driven shaft 9. Information regarding the implement 12 may include, for example, the position where the top link 461 and the pair of lower links 462 of the implement 12 are attached, or the depth of the implement 12 relative to the target area F1 (in this case, the field).

[0117] As an example, the lift limit value may be calculated using a function that uses at least one of the variables x1, x2, and x3, where variable x1 represents information about the PTO shaft 7, variable x2 represents information about the work machine 10, and variable x3 represents information about the work machine 12. Specifically, the control system 1 reads this information stored in the memory unit 312, and calculates the lift limit value by substituting this read information as variables x1, x2, and x3 into the function and performing calculations. This function can be determined, for example, by conducting experiments to see whether an excessive load is placed on the PTO shaft 7 for a large number of combinations of this information and the lift limit value. Note that variables x1, x2, and x3 are not limited to one variable each, but may be multiple variables.

[0118] As an example, the lift limit value may also be determined by referring to correlation data pre-stored in the memory unit 312. The correlation data is data showing the correlation between a combination of one or more pieces of information about the PTO shaft 7, one or more pieces of information about the work machine 10, and one or more pieces of information about the work machine 12, and the lift limit value. Specifically, the control system 1 reads out this information and the correlation data stored in the memory unit 312, and determines the lift limit value by comparing this information with the correlation data. This correlation data can be obtained, for example, by conducting experiments to see whether an excessive load is applied to the PTO shaft 7 for a large number of combinations of this information and the lift limit value.

[0119] As described above, the system automatically sets the lifting limit based on information about at least one of the PTO shaft 7, the work machine 10, and the work machine 12. This has the advantage of making it easy to set a lifting limit that does not place an excessive load on the PTO shaft 7, regardless of the operator's experience level.

[0120] As already mentioned, a universal joint (in this case, a first universal joint 81) is attached to the PTO shaft 7. If the swing angle β of the universal joint exceeds the allowable angle, an excessive load may be placed on the PTO shaft 7. Therefore, for example, the lift limit value may be automatically set according to the allowable angle of the swing angle β of the universal joint input by the operator. Here, the allowable angle refers to the allowable range of the swing angle β of the universal joint connected to the PTO shaft 7. In this embodiment, when the control system 1 receives input from the operator regarding the allowable angle of the swing angle β of the universal joint, it is configured to automatically set the lift limit value according to the input allowable angle of the swing angle β. Specifically, the control system 1 uses the input allowable angle of the swing angle β as a variable and calculates the lift limit value using a function that uses this variable. This function can be determined by conducting experiments to see whether or not an excessive load is placed on the PTO shaft 7 for a large number of combinations of the allowable angle of the swing angle β and the lift limit value.

[0121] As described above, the system automatically sets the lift limit value based on the allowable angle of the swing angle β. This has the advantage that the operator can easily set a lift limit value that prevents excessive load on the PTO shaft 7 simply by inputting the allowable angle of the swing angle β. In this case, the operator can check the allowable angle of the swing angle β to be input by referring to, for example, the catalog of the PTO shaft or shaft coupling.

[0122] Figure 4 shows an example of a setting screen Dp1 for setting the lift limit value. The setting screen Dp1 is displayed on the display unit 32 (display device) when, for example, an operator performs a first specific operation on the terminal device 3. As shown in Figure 4, the setting screen Dp1 displays the string "Work equipment lift limit" and a toggle switch A1 located to the right of the string. The toggle switch A1 is a switch for setting whether to enable or disable the suppression function that enables the lift limit function when predetermined conditions are met. The setting screen Dp1 also displays the string "Current lift height" and a numerical value A2 located to the right of the string. The numerical value A2 indicates the current height of each of the pair of lift arms 61 (i.e., the height of the work equipment 12).

[0123] When the operator turns the toggle switch A1 to "ON", the suppression function is activated, and as shown in the upper part of Figure 4, the setting screen Dp1 displays the string "Lift Height (Lift Limit)" and the lift limit value A3 located to the right of the string. When the suppression function is activated, as shown in the upper part of Figure 4, the setting screen Dp1 displays the string "Allowable Angle of Swing" and an input box A4 for inputting the allowable angle of swing β located to the right of the string. When the operator inputs the allowable angle of swing β into the input box A4, the lift limit value A3 calculated according to that allowable angle is displayed to the right of "Lift Height (Lift Limit)".

[0124] Thus, when the suppression function is enabled, the operator can set the ascent limit by inputting the allowable angle of the swing angle β. In this case, when the predetermined conditions are met, the ascent limit function using the set ascent limit becomes enabled.

[0125] On the other hand, if the operator turns the toggle switch A1 to "OFF", the suppression function is disabled, and as shown in the lower part of Figure 4, the setting screen Dp1 does not display "Lift Height (Lift Limit)" and "Allowable Angle of Swing". In this case, even if the predetermined conditions are met, the lift limit function will not be enabled. In other words, the lift limit function is not executed while the suppression function is disabled.

[0126] As described above, in the control method according to this embodiment, the enable / disable of the suppression function, which enables the upward limiting function when predetermined conditions are met, may be set according to the first setting operation. Here, the first setting operation is, for example, the ON or OFF operation of the toggle switch A1. This has the advantage that the operator can freely set whether to enable or disable the suppression function, thereby improving the ease of use of the lifting and lowering operation of the work equipment 12.

[0127] Of course, the lift limit value may be set manually by the operator. Specifically, when the control system 1 receives an input of a lift limit value from the operator, it may execute the lift limit function using the input lift limit value. For example, the input of the lift limit value may be performed on the operation screen Dp2 for operating the work equipment 12 shown in Figure 5.

[0128] The operation screen Dp2 is displayed on the display unit 32 (display device) when, for example, an operator performs a second specific operation on the terminal device 3. As shown in Figure 5, the operation screen Dp2 displays a first screen B1 that accepts an operation to change the height of the work machine 12, and a second screen B2 that accepts an operation to change the depth of the work machine 12 relative to the target area F1.

[0129] The first screen B1 is displayed to the left of the operation screen Dp2. The first screen B1 displays the text "Work implement up / down dial," a round bar-shaped gauge B3 located below the text that represents the height of the work implement 12, and an icon B4 located to the right of the gauge B3 that accepts the operation to change the height of the work implement 12. In the gauge B3, the arrow represents the current height of the work implement 12, and the bar represents the currently set upward limit.

[0130] The second screen B2 is displayed to the right of the first screen B1 on the operation screen Dp2. The second screen B2 displays the text "Depth Dial" and a round bar-shaped gauge B5 located below the text, which represents the depth of the work implement 12 relative to the target area F1. To the right of the gauge B5, an icon B6 is displayed that accepts the operation to change the depth of the work implement 12.

[0131] In the example shown in Figure 5, the bar in gauge B3 on the first screen B1 is set to a position corresponding to the "lift height (upward limit)" (i.e., the upward limit value). Here, the operator can change the position of the bar vertically, that is, change the "lift height (upward limit)" to any value, by, for example, touching the bar on gauge B3 and moving their finger up and down.

[0132] As described above, in the control method according to this embodiment, the lift limit value may be set according to the second setting operation. Here, the second setting operation is, for example, an operation to change the position of the bar in gauge B3 on the first screen B1 above up or down. This has the advantage that the operator can freely set the lift limit value, which improves the ease of use of the lifting and lowering operation of the work machine 12.

[0133] Furthermore, in the operation screen Dp2 shown in Figure 5, a screen equivalent to the settings screen Dp1 shown in Figure 4 is displayed in the lower left area B7. Therefore, by performing operations in area B7, the operator can make the same settings as those on the settings screen Dp1 shown in Figure 4. Note that area B7 does not necessarily have to be displayed on the operation screen Dp2.

[0134] Furthermore, the lift limit value is displayed in both the setting screen Dp1 shown in Figure 4 and the operation screen Dp2 shown in Figure 5. In the setting screen Dp1, the lift limit value is displayed to the right of "Lift Height (Lift Limit)". In the operation screen Dp2, the lift limit value is displayed by a bar on the gauge in the first screen B1. Both the setting screen Dp1 and the operation screen Dp2 are screens that display information related to the work machine 10.

[0135] Thus, in the control method according to this embodiment, information regarding the work machine 10 may be displayed on a display device (in this case, a display unit 32), and the lift limit value may also be displayed on the display device. This has the advantage that the operator can easily check whether the lift limit value is set correctly, as they can view information regarding the work machine 10 while checking the lift limit value.

[0136] Next, the overall flow of the suppression function will be explained with reference to Figure 6. In the following explanation, it will be assumed that the suppression function is enabled. First, until a predetermined condition is met (S1: No), the suppression processing unit 311 maintains a state in which the rise limit function is disabled. Then, when the predetermined condition is met (S1: Yes), the suppression processing unit 311 enables the rise limit function (S2).

[0137] Suppose that after the height limiting function is activated, the height of the work implement 12 reaches the height limit value (S3). At this time, since the height limiting function is activated, the lifting device 6 restricts (prohibits) further extension of the pair of hydraulic cylinders 63, thereby limiting the further rise of the work implement 12 (S4). Note that if the height limiting function is disabled, the lifting device 6 does not restrict further extension of the pair of hydraulic cylinders 63, so it is possible to raise the work implement 12 beyond the height limit value. Thereafter, the process in step S4 is executed each time the height of the work implement 12 reaches the height limit value.

[0138] However, the flowchart shown in Figure 6 is merely an example, and processes may be added or omitted as appropriate, and the order of processes may be changed as appropriate.

[0139] Incidentally, in the control method according to this embodiment, the following processing may be performed separately from the above-mentioned lift limit function. That is, if the height of the work implement 12 exceeds the lift limit value at the start of driving the PTO shaft 7, the control system 1 may disable the driving of the PTO shaft 7. Specifically, when the operator starts driving the work implement 12 using the terminal device 3, the control system 1 determines whether or not the height of the work implement 12 exceeds the lift limit value. If the control system 1 determines that the height of the work implement 12 exceeds the lift limit value, it disables the driving of the PTO shaft 7.

[0140] This has the advantage that, when starting to drive the work implement 12, if the height of the work implement 12 has already exceeded the lift limit, the work implement 12 will not be driven, thereby preventing excessive load from being placed on the PTO shaft 7. In this case, if the PTO shaft 7 is made inoperable, the control system 1 may display a message on the display unit 32 of the terminal device 3 indicating that the work implement 12 cannot be driven because its height exceeds the lift limit. In this case, there is the advantage that it becomes easier for the operator to take action to lower the work implement 12.

[0141] Furthermore, the control system 1 starts driving the PTO shaft 7 if the height of the work implement 12 does not exceed the lift limit value at the start of driving the PTO shaft 7. In this case, it is possible to drive the work implement 12 without placing an excessive load on the PTO shaft 7.

[0142] Furthermore, in the control method according to this embodiment, information regarding the restriction of the rise of the work implement 12 may be notified based on the correlation between the height of the work implement 12 and the rise limit value. Specifically, for example, when the height of the work implement 12 reaches the rise limit value, the control system 1 may display a message indicating that the height of the work implement 12 has reached the rise limit value on the display unit 32 of the terminal device 3 as information regarding the restriction of the rise of the work implement 12. Also, for example, when the height of the work implement 12 reaches near the rise limit value, the control system 1 may display a message on the display unit 32 of the terminal device 3 as information regarding the restriction of the rise of the work implement 12, such as a warning that the height of the work implement 12 will soon reach the rise limit value. Here, near the rise limit value is, for example, a value of about 80-90% of the rise limit value. This has the advantage that it makes it easier for the operator to understand that the height of the work implement 12 is about to hit the rise limit.

[0143] In addition to the above-mentioned method of displaying a message on the display unit 32, the notification may also be provided by causing a light-emitting element such as an LED (Light Emitting Diode) to emit light in a specific pattern, or by sounding a specific sound from a buzzer or the like.

[0144] [6] Variant The following lists some modifications of Embodiment 1. The modifications described below can be combined and applied as appropriate.

[0145] In the above embodiment 1, the height of the work implement 12 is defined by the rotation angle α of each of the pair of lift arms 61, but is not limited to this. For example, the height of the work implement 12 may be defined by the extension and retraction length of each of the pair of hydraulic cylinders 63. Alternatively, for example, the height of the work implement 12 may be defined by the rotation angle of each of the pair of lower links 462.

[0146] The control system 1 in this disclosure includes a computer system. The computer system mainly consists of one or more processors and one or more memories as hardware. The functions of the control system 1 in this disclosure are realized by the processor executing a program (a control program for a work machine) recorded in the memory of the computer system. The program may be pre-recorded in the memory of the computer system, provided via a telecommunications line, or provided on a non-temporary recording medium such as a memory card, optical disk, or hard disk drive that can be read by the computer system. Furthermore, some or all of the functional parts included in the control system 1 may be composed of electronic circuits.

[0147] Furthermore, it is not essential for control system 1 to have at least some of its functions integrated into a single enclosure; the components of control system 1 may be distributed across multiple devices (e.g., control device 2 and terminal device 3). Conversely, functions that are distributed across multiple devices in Embodiment 1 may be integrated into a single enclosure. Moreover, at least some of the functions of control system 1 may be implemented by the cloud (cloud computing) or the like.

[0148] Furthermore, the terminal device 3 is not limited to general-purpose terminals such as tablet terminals, smartphones, or laptop computers, but may also consist of dedicated terminals. Moreover, multiple terminal devices 3 may be associated with one work machine 10, in which case multiple terminal devices 3 can control one work machine 10. Conversely, one terminal device 3 may be associated with multiple work machines 10, in which case one terminal device 3 can control multiple work machines 10.

[0149] For example, terminal device 3 may be a portable terminal device 3 not installed on the work machine 10. In this case, the operator can use the portable terminal device 3 to remotely control the work machine 10 or to view various information about the work machine 10. Also, for example, if there are two terminal devices 3, one of them may be a terminal device 3 installed on the work machine 10 and the other may be a portable terminal device 3. In this case, the operator can use the terminal device 3 installed on the work machine 10 to directly operate the work machine 10 or to view various information about the work machine 10. Furthermore, the operator can also use the portable terminal device 3 to remotely control the work machine 10 or to view various information about the work machine 10.

[0150] [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.

[0151] <Note 1> Controlling the lifting device that raises and lowers the work equipment attached to the body of the work machine, The system includes a function that, when certain conditions are met, enables a height limit function to restrict the upward movement of the work implement when its height reaches a height limit value. A method for controlling industrial machinery.

[0152] <Note 2> The predetermined conditions include driving conditions relating to the driving state of the power take-off shaft that transmits the power generated by the power source to the work implement. Control method for the work machine described in Appendix 1.

[0153] <Note 3> The aforementioned driving conditions include the power take-off shaft being driven. Control method for the work machine described in Appendix 2.

[0154] <Note 4> The aforementioned predetermined conditions include positional conditions relating to the position of the work machine, A control method for the work machine described in any one of the appendices 1 to 3.

[0155] <Note 5> The system further includes automatically setting the aforementioned upper limit value without operator intervention. A control method for the work machine described in any one of the appendices 1 to 4.

[0156] <Note 6> The height of the aforementioned work machine is defined as a settable range that can be set as the aforementioned upward limit value. The initial value of the aforementioned upward limit is set to the lower limit of the set range. Control method for the work machine described in Appendix 5.

[0157] <Note 7> The aforementioned lift limit value is automatically set based on information regarding the power take-off shaft that transmits power generated by the power source to the work implement, the work implement, and at least one of the work implements. Control method for the work machine described in Appendix 5.

[0158] <Note 8> It further has the ability to accept input for an acceptable angle, The aforementioned allowable angle is the allowable range of the swing angle of the universal joint connected to the power take-off shaft that transmits the power generated by the power source to the work machine, The aforementioned upward limit value is automatically set according to the allowable angle. Control method for the work machine described in Appendix 5.

[0159] <Note 9> The system further includes enabling / disabling the suppression function, which enables the upward limiting function when the aforementioned predetermined conditions are met, according to a first setting operation. A control method for the work machine described in any one of the appendices 1 to 8.

[0160] <Note 10> The system further includes setting the upper limit value in accordance with the second setting operation. A control method for the work machine described in any one of the appendices 1 to 9.

[0161] <Note 11> The system further includes displaying information related to the aforementioned work machine on a display device, The display device displays the upper limit value. A control method for the work machine described in any one of the appendices 1 to 10.

[0162] <Note 12> The power take-off shaft, which transmits power generated by the power source to the work implement, is further configured to disable the drive of the power take-off shaft if the height of the work implement exceeds the lift limit value at the start of the drive of the power take-off shaft. A control method for the work machine described in any one of the appendices 1 to 11.

[0163] <Note 13> The system further provides information regarding the limit on the upward movement of the work implement based on the correlation between the height of the work implement and the upward movement limit value. A control method for the work machine described in any one of the appendices 1 to 12.

[0164] <Note 14> The control method for the work machine described in any one of the appendices 1 to 13, A control program for a work machine to be executed by one or more processors.

[0165] <Note 15> A work control unit that controls a lifting device for raising and lowering a work implement attached to the body of a work machine, The system includes a suppression processing unit that enables a height limiting function to restrict the upward movement of the work implement when the height of the work implement reaches a height limit value, provided that predetermined conditions are met. Control system for industrial machinery.

[0166] <Note 16> The control system for the work machine described in Appendix 15, Equipped with the machine body of the work machine, Work system. [Explanation of Symbols]

[0167] 1. Control system for industrial machinery 10 Working Machines 11 aircraft 12 Work Machines 18 Power source 23 Work Control Unit 311 Suppression Processing Unit 32 Display section (display device) 6. Lifting device 7 Power Takeoff Axis 81. First universal joint (universal joint)

Claims

1. Controlling the lifting device that raises and lowers the work equipment attached to the body of the work machine, The system includes a function that, when certain conditions are met, enables a height limit function to restrict the upward movement of the work implement when its height reaches a height limit value. A method for controlling industrial machinery.

2. The predetermined conditions include driving conditions relating to the driving state of the power take-off shaft that transmits the power generated by the power source to the work implement. A method for controlling a work machine according to claim 1.

3. The aforementioned driving conditions include the power take-off shaft being driven. A method for controlling a work machine according to claim 2.

4. The aforementioned predetermined conditions include positional conditions relating to the position of the work machine, A method for controlling a work machine according to any one of claims 1 to 3.

5. The system further includes automatically setting the aforementioned upper limit value without operator intervention. A method for controlling a work machine according to any one of claims 1 to 3.

6. The height of the aforementioned work machine is defined as a settable range that can be set as the aforementioned upward limit value. The initial value of the aforementioned upward limit is set to the lower limit of the set range. A method for controlling a work machine according to claim 5.

7. The aforementioned lift limit value is automatically set based on information regarding the power take-off shaft that transmits power generated by the power source to the work implement, the work implement, and at least one of the work implements. A method for controlling a work machine according to claim 5.

8. It further has the ability to accept input for an acceptable angle, The aforementioned allowable angle is the allowable range of the swing angle of the universal joint connected to the power take-off shaft that transmits the power generated by the power source to the work machine, The aforementioned upward limit value is automatically set according to the allowable angle. A method for controlling a work machine according to claim 5.

9. The system further includes enabling / disabling the suppression function, which enables the upward limiting function when the predetermined conditions are met, according to a first setting operation. A method for controlling a work machine according to any one of claims 1 to 3.

10. The system further includes setting the upper limit value in accordance with the second setting operation. A method for controlling a work machine according to any one of claims 1 to 3.

11. The system further includes displaying information related to the aforementioned work machine on a display device, The display device displays the upper limit value. A method for controlling a work machine according to any one of claims 1 to 3.

12. The power take-off shaft, which transmits power generated by the power source to the work implement, is driven at the start of the drive, and if the height of the work implement exceeds the lift limit value, the power take-off shaft is further disabled. A method for controlling a work machine according to any one of claims 1 to 3.

13. The system further provides information regarding the limit on the upward movement of the work implement based on the correlation between the height of the work implement and the upward movement limit value. A method for controlling a work machine according to any one of claims 1 to 3.

14. A method for controlling a work machine according to any one of claims 1 to 3, A control program for a work machine to be executed by one or more processors.

15. A work control unit that controls a lifting device for raising and lowering a work implement attached to the body of a work machine, The system includes a suppression processing unit that enables a height limiting function to restrict the upward movement of the work implement when the height of the work implement reaches a height limit value, provided that predetermined conditions are met. Control system for industrial machinery.

16. A control system for a work machine according to claim 15, Equipped with the machine body of the work machine, Work system.

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