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

Abstract

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 machine, which can easily improve the reliability of a determined work load.SOLUTION: A control method for a work machine 3 includes calculating a work load based on a monitored object related to the work machine 3, and transitioning to a calculation pause state in which calculation of a work load L1 is paused when a specific operating state of the work machine 3 is detected. The work load L1 is a load that is applied to a specific portion of the work machine 3 when work is performed using work implement 33 of the work machine 3.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a work machine control method, a work machine control program, a work machine control system, and a work machine, which are used in a work machine in which a work load is applied to a specific portion during work using the work machine. [Background technology]

[0002] As a related art, a work machine (hydraulic excavator combined with crane) is known in which an arm is rotatably attached to the tip of a boom that is rotatably attached to the body in the forward and backward directions, a bucket for excavation is rotatably attached to the tip of the arm, and a hook unit for lifting loads is attached to the bucket (see, for example, Patent Document 1). The work machine according to the related art is capable of performing load lifting work (crane work) and excavation work.

[0003] In the work machine according to the above-mentioned related art, the working load (suspension load) at the suspension position of the hook is calculated based on the pressure acting on the boom (boom pressure), the boom working angle, the arm working angle, and the like. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2000-87395 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned related technology, for example, if boom operation is suddenly stopped during lifting operations, pressure fluctuations will occur in the boom pressure, and the work load calculated based on the boom pressure, etc., may deviate from the actual work load.

[0006] An object of the present invention is to provide a work machine control method, a work machine control program, a work machine control system, and a work machine that can easily improve the reliability of the determined work load. [Means for solving the problem]

[0007] A method for controlling a work machine according to one aspect of the present invention includes calculating a work load based on a monitored object related to the work machine, and transitioning to a calculation pause state in which calculation of the work load is paused when a specific operating state of the work machine is detected. The work load is a load applied to a specific portion of the work machine when work is carried out using a working implement of the work machine.

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

[0009] A work machine control system according to one aspect of the present invention includes a calculation processing unit and a pause processing unit. The calculation processing unit calculates a work load applied to a specific portion of a work machine when a work is carried out using a work implement of the work machine, based on a monitored object related to the work machine. When a specific operating state of the work machine is detected, the pause processing unit transitions to a calculation pause state in which calculation of the work load by the calculation processing unit is paused.

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

[0011] According to the present invention, it is possible to provide a work machine control method, a work machine control program, a work machine control system, and a work machine that can easily improve the reliability of the determined work load. [Brief description of the drawings]

[0012] [Figure 1]FIG. 1 is a schematic perspective view showing the overall configuration of a work machine according to a first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing a hydraulic circuit and the like of the work machine according to the first embodiment. [Diagram 3] FIG. 3 is a schematic left side view of the work machine according to the first embodiment. [Figure 4] FIG. 4 is a schematic left side view of the work machine according to the first embodiment during lifting operation. [Diagram 5] FIG. 5 is an explanatory diagram that illustrates a schematic example of an operation of the work machine control system according to the first embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of the operation of the work machine control system according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example of the present invention, and is not intended to limit the technical scope of the present invention.

[0014] (Embodiment 1) [1] Overall structure As shown in Fig. 1, the work machine 3 according to this embodiment is equipped with a traveling section 31, a rotating section 32, and a work implement 33 on a body 30. Moreover, as shown in Fig. 2, the work machine 3 is further equipped with a work machine control system 1 (hereinafter also simply referred to as the "control system 1"). In addition, the body 30 is further equipped with a display device 2, an operating device 35, a sound output section, etc.

[0015] The term "working machine" in this disclosure means a machine for various works, and examples thereof include working vehicles such as backhoes (including hydraulic excavators, mini excavators, etc.), wheel loaders, and carriers. The working machine 3 is equipped with a working implement 33 configured to be able to perform one or more works. The working machine 3 is not limited to a "vehicle" and may be, for example, a work vessel, a work flying object such as a drone or a multicopter, etc. Furthermore, the working machine 3 is not limited to a construction machine (construction machinery), and may be, for example, an agricultural machine (farm machinery) such as a rice transplanter, a tractor, or a combine harvester. In this embodiment, unless otherwise specified, a case will be described in which the working machine 3 is a riding type backhoe and can perform lifting work (crane work), excavation work, ground leveling work, trench excavation work, loading work, etc. as work.

[0016] Also, in this embodiment, for convenience of explanation, the vertical direction when the work machine 3 is in a usable state is defined as the up-down direction D1. Furthermore, when the swivel unit 32 is in a non-swivel state, the front-rear direction D2 and the left-right direction D3 are defined based on the direction as seen by the user (operator) riding on the work machine 3 (the driving unit 321) of the work machine 3. In other words, each direction used in this embodiment is a direction defined based on the body 30 of the work machine 3, and the direction in which the body 30 moves when the work machine 3 moves forward is "forward", and the direction in which the body 30 moves when the work machine 3 moves backward is "rear". Similarly, the direction in which the front end of the body 30 moves when the work machine 3 turns right is "rightward", and the direction in which the front end of the body 30 moves when the work machine 3 turns left is "leftward". However, these directions are not intended to limit the use direction of the work machine 3 (direction during use).

[0017] The work machine 3 is equipped with a prime mover that serves as a power source. In this embodiment, as an example, the prime mover is a diesel engine. The prime mover is driven by fuel (here, diesel) supplied from a fuel tank. In the work machine 3, for example, the prime mover drives a hydraulic pump 41 (see FIG. 2 ), and hydraulic oil is supplied from the hydraulic pump 41 to hydraulic actuators (including a hydraulic motor 43 and a hydraulic cylinder 44, etc.) of each part of the machine body 30, thereby driving the machine body 30. The prime mover is a device that converts energy such as heat of combustion or steam, or electricity, into mechanical power (power), and supplies power (power oil) to each part of the machine body 30 of the work machine 3 to drive each part of the machine body 30.

[0018] Such a work machine 3 is controlled, for example, by a user (operator) riding on the driving section 321 of the machine body 30 operating an operating lever or the like of the operating device 35. In other words, the power generated by the prime mover is distributed to each part of the machine body 30 in accordance with the operation of the operator, and the work machine 3 operates in accordance with the operation of the operator. The prime mover that serves as the power source for the work machine 3 is not limited to a diesel engine, and may be, for example, an internal combustion engine (engine) other than a diesel engine, an electric motor (electric motor), or a hybrid power source including an internal combustion engine and an electric motor.

[0019] In this embodiment, since it is assumed that the work machine 3 is a riding type backhoe as described above, the work machine 33 is driven according to the operation of a user (operator) riding on the driving unit 321 to perform work such as lifting work. The driving unit 321 on which the user rides is provided on the rotating unit 32.

[0020] Here, the driving section 321 of the machine body 30 is equipped with a display device 2, an operation device 35, a sound output section, etc., and the user can operate the operation device 35 while viewing various information related to the work machine 3 displayed on the display device 2. As an example, information related to the operating state of the work machine 3, such as the cooling water temperature and hydraulic oil temperature, is displayed on the display screen of the display device 2, allowing the user to check information related to the operating state of the work machine 3, which is necessary for operating the operation device 35, on the display device 2.

[0021] The traveling unit 31 has a traveling function and is configured to be able to travel (including turn) on the ground. The traveling unit 31 has, for example, a pair of left and right crawlers 311 and a blade 312. The traveling unit 31 further has a hydraulic motor 43 (hydraulic actuator) for driving the crawlers 311 and the like.

[0022] The swivel unit 32 is located above the travel unit 31, and is configured to be rotatable relative to the travel unit 31 about a rotation axis along the up-down direction D1. The swivel unit 32 has a hydraulic motor (hydraulic actuator) for rotation, etc. In addition to a driving unit 321, the swivel unit 32 is equipped with a prime mover, a hydraulic pump 41, etc. Furthermore, a boom bracket 322 to which a work machine 33 is attached is provided at the front end of the swivel unit 32.

[0023] The work machine 33 is configured to be able to perform one or more tasks. The work machine 33 is supported by the boom bracket 322 of the swivel section 32, and performs tasks. The work machine 33 has a bucket 331. The bucket 331 is a type of attachment (working tool) attached to the body 30 of the work machine 3, and is made up of any tool selected from multiple types of attachments depending on the content of the task. As an example, the bucket 331 is removably attached to the body 30, and is replaced depending on the content of the task. As attachments for the work machine 3, in addition to the bucket 331, for example, various tools such as a breaker, an auger, a crusher, a fork, a fork claw, a steel frame cutter, an asphalt cutter, a grass cutter, a ripper, a mulcher, a tilt rotator, and a tamper can be used.

[0024] The work machine 33 further includes a boom 332, an arm 333, and a hydraulic actuator (including the hydraulic cylinder 44 and the hydraulic motor), etc. The bucket 331 is attached to the tip of the arm 333.

[0025] The boom 332 is rotatably supported by a boom bracket 322 provided on the machine body 30 (the rotating section 32). Specifically, as shown in Fig. 3, the boom 332 is rotatably supported by the boom bracket 322 around a rotation axis Ax1 along the horizontal direction. The boom 332 has a shape that extends upward from a base end supported by the boom bracket 322.

[0026] The arm 333 is connected to the tip of the boom 332. As shown in Fig. 3, the arm 333 is supported by the boom 332 so as to be rotatable about a rotation axis Ax2 that extends in the horizontal direction.

[0027] Particularly in this embodiment, the work machine 33 has a multi-joint structure in which the boom 332 and the arm 333 are configured to be rotatable individually. That is, as shown in Fig. 3, the boom 332 and the arm 333 each rotate about a horizontal rotation axis Ax1, Ax2, and thereby the multi-joint work machine 33 including the boom 332 and the arm 333 can be extended or folded as a whole.

[0028] The work machine 33 operates by receiving power from a prime mover as a power source. Specifically, a hydraulic pump 41 is driven by the prime mover, and hydraulic oil is supplied from the hydraulic pump 41 to hydraulic actuators (hydraulic cylinders 44, etc.) of the work machine 33, thereby operating each part of the work machine 33 (a bucket 331, a boom 332, and an arm 333).

[0029] Here, the work machine 3 according to this embodiment is configured so that the work implement 33 can perform a plurality of tasks including a lifting task. In this embodiment, the work machine 3 is a backhoe with a lifting function, and the work implement 33 is configured so that it can perform a lifting task in addition to an excavation task using a bucket 331. For this reason, the work implement 33 is provided with a hook 334 for performing the lifting task, as shown in FIG. 4.

[0030] 4, hook 334 is disposed at the tip of working machine 33. Specifically, hook 334 is provided so as to protrude downward from bucket 331. When lifting work is not being performed, hook 334 is housed, for example, in bucket link 335 connecting arm 333 and bucket 331, so that hook 334 is unlikely to get in the way when excavation work or the like is performed using bucket 331.

[0031] When performing a lifting operation, the working machine 33 can load and unload the load (object) by operating the boom 332 and the arm 333 with the load (object) suspended from the hook 334. Furthermore, with the load suspended from the hook 334 provided at the tip of the working machine 33, the swivel unit 32 can rotate to rotate the load around the rotation axis of the swivel unit 32.

[0032] When performing a lifting operation, a load corresponding to the weight of the lifted load is applied to the hook 334 and the bucket 331 as a "lifting load". The lifting load is an example of a working load L1 (see FIG. 4). In the present disclosure, the "working load" is a load applied to a specific part of the work machine 3 when performing work using the work implement 33 of the work machine 3, and includes, in addition to the lifting load, for example, a live load of soil and sand in loading work of soil and sand. In short, during a lifting operation, a "lifting load" corresponding to the weight of the lifted load is applied to the hook 334 and the bucket 331 as the "specific part" of the work machine 3 as the working load L1. On the other hand, during loading work of soil and sand, a "live load" corresponding to the weight of soil and sand is applied to the bucket 331 as the "specific part" of the work machine 3 as the working load L1.

[0033] Here, the machine body 30 is provided with a boom angle sensor 52 (see FIG. 2) and an arm angle sensor 53 (see FIG. 2) that detect at least the angles of the boom 332 and the arm 333 (boom angle and arm angle), respectively.

[0034] The boom angle sensor 52 is electrically connected to the control system 1 and outputs the detected boom angle to the control system 1. The boom angle here refers to the rotation angle of the boom 332 about the rotation axis Ax1 along the left-right direction D3 relative to the boom bracket 322 of the machine body 30.

[0035] The arm angle sensor 53 is electrically connected to the control system 1 and outputs the detected arm angle to the control system 1. The arm angle here refers to a rotation angle of the arm 333 about a rotation axis Ax2 along the left-right direction D3 relative to the boom 332.

[0036] Furthermore, since the respective lengths of the boom 332 and the arm 333 are known, it is possible to specify the posture (working posture) of the work implement 33 by specifying the boom angle and the arm angle.

[0037] The machine body 30 is further provided with a bottom pressure sensor 51 (see FIG. 2) disposed on the bottom side of the hydraulic cylinder 44 that drives the boom 332. The bottom pressure sensor 51 is electrically connected to the control system 1, and outputs the detected pressure (hydraulic pressure) on the bottom side of the hydraulic cylinder 44 to the control system 1.

[0038] Similarly to the work machine 33, each of the traveling unit 31 and the swivel unit 32 receives power from a prime mover as a power source and operates. That is, the swivel unit 32 and the traveling unit 31 operate when hydraulic oil is supplied from the hydraulic pump 41 to the hydraulic motor 43 of the traveling unit 31 and the hydraulic motor of the swivel unit 32, etc.

[0039] The actuators (hydraulic actuators including the hydraulic motor 43, hydraulic cylinder 44, etc. in this embodiment) provided in each part of the machine body 30 operate in response to operation of the operation device 35. In other words, the work machine 3 according to this embodiment is equipped with actuators that operate in response to operation of the operation device 35. Therefore, the work machine 3 performs various operations such as forward and backward movement by the traveling unit 31, rotation by the swivel unit 32, and lifting work by the work implement 33 in response to operation of the operation device 35 by a user (operator).

[0040] Fig. 2 shows a schematic diagram of the hydraulic circuit and the electric circuit (electrical connection relationship) of the work machine 3 according to this embodiment. In Fig. 2, solid lines indicate high-pressure oil passages (for hydraulic oil), dotted lines indicate low-pressure oil passages (for pilot oil), and dashed arrows indicate paths of electric signals.

[0041] As shown in FIG. 2, the work machine 3 is equipped with a hydraulic pump 41, a hydraulic motor 43 (not shown in FIG. 2), a hydraulic cylinder 44, and a prime mover, as well as a pilot pump 42, a remote control valve 45, a control valve 461, a cutoff switch 462, a cutoff lever 463, a directional control valve (control valve) 48, and the like.

[0042] Hydraulic oil from a hydraulic pump 41 driven by a prime mover is supplied to a hydraulic motor 43 of the traveling part 31, a hydraulic motor of the rotating part 32, a hydraulic cylinder 44 of the work machine 33, etc. This drives hydraulic actuators such as the hydraulic motor 43 and the hydraulic cylinder 44.

[0043] Hydraulic actuators such as the hydraulic motor 43 and the hydraulic cylinder 44 are provided with a pilot-type directional control valve 48 capable of switching the direction and flow rate of hydraulic oil from the hydraulic pump 41. The directional control valve 48 is driven by the supply of pilot oil, which serves as an input command, from the pilot pump 42.

[0044] Here, for example, a remote control valve 45 is provided in a supply path of pilot oil to a directional control valve 48 corresponding to a hydraulic cylinder 44 of the work machine 33. The remote control valve 45 outputs a work operation command for the work machine 33 in response to operation of an operating device 35 (operation lever). The work operation command instructs operations such as extending and retracting the work machine 33. In addition, the flow rate of pilot oil supplied from the pilot pump 42 to the remote control valve 45 can be adjusted by a control valve 461.

[0045] The control valve 461 is an electromagnetic control valve (solenoid valve) and is inserted between the remote control valve 45 and the pilot pump 42. The control valve 461 is connected to a power source via a cut-off switch 462 and operates according to a current supplied from the power source. The control valve 461 is assumed to be an (electromagnetic) proportional control valve here, but is not limited to this and may be, for example, an opening / closing valve that can switch between opening and closing a flow path.

[0046] The control valve 461 opens the flow path of the pilot oil when it is energized, that is, when a current is being supplied as a control signal, and blocks the flow path of the pilot oil when it is de-energized, that is, when the current as a control signal is cut off. Therefore, when the supply current (control signal) to the control valve 461 is cut off, the hydraulic actuator (hydraulic cylinder 44, etc.) corresponding to the remote control valve 45 becomes inoperable, and the hydraulic actuator is forcibly stopped regardless of the operation of the operating device 35.

[0047] Similarly, a remote control valve is provided in a supply path of pilot oil to a directional control valve corresponding to the hydraulic motor 43 of the traveling unit 31. This remote control valve outputs a travel operation command for the traveling unit 31 in response to the operation of the operating device 35 (operation lever). The travel operation command instructs the traveling motion (forward or backward, etc.) of the traveling unit 31. Furthermore, a remote control valve is provided in a supply path of pilot oil to a directional control valve corresponding to the hydraulic motor of the swivel unit 32. This remote control valve outputs a swing operation command for the swivel unit 32 in response to the operation of the operating device 35 (operation lever). The swing operation command instructs the swing motion (left swing or right swing, etc.) of the swivel unit 32. A control valve 461 is also inserted between these remote control valves and the pilot pump 42.

[0048] The cutoff switch 462 is linked to the cutoff lever 463. The cutoff lever 463 is disposed in the driving section 321 of the machine body 30, and receives an operation input by a user (operator). In the present embodiment, as an example, the cutoff lever 463 can be operated along the up-down direction D1. When the cutoff lever 463 is in the "up position" which is the upper end position of the movable range, the cutoff switch 462 is "off", and when the cutoff lever 463 is in the "down position" which is the lower end position of the movable range, the cutoff switch 462 is "on". The cutoff switch 462 is connected to the control system 1, and the on / off state of the cutoff switch 462, that is, the operation state of the cutoff lever 463, is monitored by the control system 1.

[0049] Therefore, when the cutoff lever 463 is in the "down position", the control valve 461 is energized, and the hydraulic actuator (hydraulic cylinder 44, etc.) is driven by operation of the operation device 35. In contrast, when the cutoff lever 463 is in the "up position", the control valve 461 is deenergized, and the hydraulic actuator is forcibly stopped without operation of the operation device 35. Therefore, to drive the hydraulic actuator (hydraulic cylinder 44, etc.), the user (operator) needs to operate the cutoff lever 463 to the "down position".

[0050] Furthermore, since each of the swivel unit 32 and the traveling unit 31 is operated by hydraulic oil being supplied from the hydraulic pump 41 to a hydraulic actuator (hydraulic motor 43, etc.), when the cutoff lever 463 is in the "raised position", the swivel unit 32 and the traveling unit 31 are also disabled. In other words, when the cutoff lever 463 is in the "raised position", the working machine 33, the swivel unit 32 and the traveling unit 31 are all forcibly disabled from being driven.

[0051] In this embodiment, the state of the cutoff lever 463 when it is in the "up position", i.e., when the work machine 3 cannot be operated, is defined as the "locked state". On the other hand, the state of the cutoff lever 463 when it is in the "down position", i.e., when the work machine 3 can be operated, is defined as the "unlocked state".

[0052] In short, when the cutoff switch 462 is off, it is in a "locked state" in which the operation of the work machine 3 is restricted (including prohibited), and when it is on, it is in an "unlocked state" in which the operation of the work machine 3 is not restricted. And when the cutoff lever 463 is in the "raised position" and the cutoff switch 462 is in a locked state (off), the operation of the work machine 3 is forcibly restricted without the operation of the operating device 35. The cutoff lever 463 is a lever that is operated when locking the operation of the work machine 3 in this way, and is synonymous with a gate lock lever.

[0053] The operation device 35 is disposed in the driving section 321 of the machine body 30, and is a user interface for receiving operation input from a user (operator). The operation device 35 includes, for example, an operation lever, and controls the remote control valve 45 according to the amount of operation of the operation lever. This allows the operator to operate the remote control valve 45 by operating the operation device 35, to specify the direction and flow rate of hydraulic oil from the hydraulic pump 41, and to operate the work machine 3.

[0054] The control system 1 mainly comprises a computer system having one or more processors, such as a CPU (Central Processing Unit), and one or more memories, such as a ROM (Read Only Memory) and a RAM (Random Access Memory), and executes various processes (information processing). In this embodiment, the control system 1 is an integrated controller that controls the entire work machine 3, and is composed of, for example, an electronic control unit (ECU). However, the control system 1 may be provided separately from the integrated controller, or may be mainly composed of one processor or multiple processors. The control system 1 will be described in detail in the section "[2] Configuration of the control system".

[0055] The display device 2 is disposed in the driving section 321 of the machine body 30, and is a user interface for presenting (displaying) various information to the user. Furthermore, the display device 2 accepts various operations by the user, for example, by outputting an electrical signal in response to the user's operation. This allows the user (operator) to visually check the display screen displayed on the display device 2, and also allows the user to operate the display device 2 as necessary.

[0056] The display device 2 is configured to be able to communicate with the control system 1, and is able to send and receive data between the control system 1. In this embodiment, as an example, the display device 2 is a dedicated device used in the work machine 3.

[0057] In addition to the above-mentioned configuration, the machine body 30 further includes a drive unit, a communication terminal, a fuel tank, a sound output unit, a battery, etc. The drive unit is a device for supplying power to the attachment of the work machine 33, and is made up of a device (mechanism) such as a PTO (Power take-off) for extracting power from a prime mover as power for driving an attachment made up of hydraulic equipment. Furthermore, the machine body 30 is equipped with various sensors (including cameras) for detecting detection targets in a monitoring area around the work machine 33, such as a camera for capturing images of the periphery of the machine body 30.

[0058] [2] Control system configuration Next, the configuration of the control system 1 according to this embodiment will be described with reference to Fig. 2. The control system 1 controls each part of the machine body 30 (including the traveling section 31, the rotating section 32, the work implement 33, etc.). In this embodiment, the control system 1 is a component of the work machine 3, and constitutes the work machine 3 together with the machine body 30, etc. In other words, the work machine 3 according to this embodiment includes at least the control system 1 and the machine body 30.

[0059] As shown in Fig. 2, the control system 1 includes a status monitoring unit 11, an arithmetic processing unit 12, a pause processing unit 13, and an output processing unit 14. In this embodiment, as an example, the control system 1 is mainly configured as a computer system having one or more processors, and these multiple functional units (status monitoring unit 11, etc.) are realized by the one or more processors executing a work machine control program. These multiple functional units included in the control system 1 may be provided distributed across multiple housings, or may be provided in a single housing.

[0060] The control system 1 is configured to be able to communicate with devices provided in each part of the machine body 30. That is, at least a bottom pressure sensor 51, a boom angle sensor 52, an arm angle sensor 53, a display device 2, a cut-off switch 462, and the like are connected to the control system 1. This allows the control system 1 to control the display device 2, etc., and to acquire outputs from the bottom pressure sensor 51, the boom angle sensor 52, the arm angle sensor 53, and the like. Here, the control system 1 may directly exchange various information (data) with each device, or may indirectly exchange information (data) with each device via a repeater, etc. The control system 1 and the devices provided in each part of the machine body 30 can communicate with each other by a communication method such as CAN (Controller Area Network), for example.

[0061] The status monitoring unit 11 performs a status monitoring process to monitor the operating status of the work machine 3. The operating status here includes the operating status of each of the traveling unit 31, the swivel unit 32, and the work implement 33 of the work machine 3, and includes, for example, the traveling state of the work machine 3 caused by the traveling unit 31.

[0062] The calculation processing unit 12 performs calculation processing to calculate the work load L1 applied to a specific portion of the work machine 3 when work is performed using the work implement 33 of the work machine 3. Here, the calculation processing unit 12 calculates the work load L1 based on a monitored object related to the work machine 3. In this embodiment, as described above, during lifting work, the "hoisting load" corresponding to the weight of a load suspended from the hook 334 and bucket 331, which are the "specific portion" of the work machine 3, is an example of the work load L1.

[0063] The "monitoring target" in this disclosure refers to a physical quantity measured by various sensors provided in each part of the machine body 30, and includes, for example, the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332 measured by the bottom pressure sensor 51. Furthermore, the "monitoring target" includes the posture (working posture) of the work implement 33 identified from the boom angle measured by the boom angle sensor 52 and the arm angle measured by the arm angle sensor 53.

[0064] In short, the control system 1 according to this embodiment does not directly detect the work load L1 (the hanging load in this embodiment) with a sensor or the like, but indirectly determines it by calculation in the calculation processor 12 based on the monitored object. For example, if the bottom side pressure of the hydraulic cylinder 44 for driving the boom 332 measured by the bottom pressure sensor 51 and the working posture are known, it is possible to calculate the work load L1 applied to the tip of the work implement 33 (the hook 334 and the bucket 331) by utilizing the balance of moments.

[0065] The pause processing unit 13 performs pause processing to transition to a calculation pause state in which calculation of the work load L1 is paused when a specific operating state of the work machine 3 is detected. That is, in this embodiment, the calculation processing unit 12 does not always perform calculation to obtain the work load L1, but pauses (stops) the calculation to obtain the work load L1 during the period in the calculation pause state.

[0066] The "specific operating state" in the present disclosure is a specific operating state that satisfies a predetermined condition among the operating states of the work machine 3. In the present embodiment, as an example, the specific operating state includes a sudden stop, a sudden start, a traveling state, and the like of the work machine 33.

[0067] The output processing unit 14 performs output processing to output the work load L1. As an example in this embodiment, the output processing unit 14 is configured to output the work load L1 to the display device 2, thereby causing the display device 2 to display the work load L1. The manner of output by the output processing unit 14 is not limited to output to the display device 2. For example, in addition to or instead of outputting to the display device 2, the output processing unit 14 may output the work load L1 by means of outputting to a printing device, outputting to a sound output unit, transmitting to another terminal, writing to a non-transitory recording medium, or a combination of these.

[0068] [3] Control method for work machine An example of a control method for the work machine 3 executed mainly by the control system 1 (hereinafter simply referred to as a "control method") will be described below with reference to Figs. 5 and 6.

[0069] The control method according to this embodiment is executed by a control system 1 having a computer system as its main component, and in other words is embodied in a work machine control program (hereinafter simply referred to as a "control program"). In other words, the control program according to this embodiment is a computer program for causing one or more processors to execute each process related to the control method. Such a control program may be executed, for example, by the control system 1 and the display device 2 in cooperation with each other.

[0070] Here, the control system 1 executes the various processes described below relating to the control method when a specific, preset start operation is performed to execute the control program. The start operation is, for example, an operation to start the prime mover of the work machine 3 (ignition on). On the other hand, the control system 1 ends the various processes described below relating to the control method when a specific, preset end operation is performed. The end operation is, for example, an operation to stop the prime mover of the work machine 3 (ignition off).

[0071] The control method according to this embodiment includes determining the work load L1 by calculation based on a monitored object related to the work machine 3, and transitioning to a calculation pause state in which calculation of the work load L1 is paused when a specific operating state of the work machine 3 is detected. The work load L1 is a load that is applied to a specific portion of the work machine 3 when work is performed using the work implement 33 of the work machine 3.

[0072] In short, basically, the calculation processing unit 12 of the control system 1 performs calculation processing to calculate the working load L1 applied to a specific portion of the work machine 3 based on a monitoring target related to the work machine 3. In this embodiment, the "suspension load" applied to a specific portion (hook 334 and bucket 331) of the work machine 3 during suspension work is an example of the working load L1. The calculation processing unit 12 calculates the working load L1 (suspension load) based on the "monitoring target" including, for example, the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332 measured by the bottom pressure sensor 51, and the posture (working posture) of the work implement 33. Here, the working posture can be identified from the boom angle measured by the boom angle sensor 52 and the arm angle measured by the arm angle sensor 53.

[0073] In this way, in the control method according to this embodiment, the working load L1 is indirectly calculated based on the monitored object by the calculation processing unit 12. Therefore, for example, if the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332 measured by the bottom pressure sensor 51 and the working posture are known, it is possible to calculate the working load L1 using the balance of moments. Therefore, for example, even if a rod pressure sensor for measuring the pressure on the rod side of the hydraulic cylinder 44 for driving the boom 332 is not provided, the working load L1 can be calculated by a one-sensor method using one pressure sensor (bottom pressure sensor 51).

[0074] Furthermore, when the pause processing unit 13 of the control system 1 detects a specific operating state of the work machine 3, the pause processing unit 13 transitions to a calculation pause state in which the calculation of the work load L1 is paused. In this embodiment, the specific operating state is a sudden stop, a sudden start, a traveling state, etc. of the work implement 33. In other words, when the pause processing unit 13 detects (by the state monitoring unit 11) a specific operating state such as a sudden stop, a sudden start, or a traveling state of the work implement 33, the pause processing unit 13 transitions to a calculation pause state and pauses (stops) the calculation of the work load L1 (suspension load) in the calculation processing unit 12. As a result, when a specific operating state is detected, the calculation of the work load L1 (suspension load) based on the "monitoring target" including the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332 and the posture (working posture) of the work implement 33 is not performed.

[0075] Therefore, for example, when the operation of the boom 332 is suddenly stopped during lifting work (sudden stop), in a situation where the pressure (boom pressure) of the hydraulic cylinder 44 for driving the boom 332 included in the monitoring target is likely to fluctuate, the calculation of the work load L1 based on the monitoring target is not performed. For example, when the boom 332 suddenly stops, the kinetic energy of the working fluid (hydraulic oil) supplied to the hydraulic cylinder 44 is converted into elastic energy, which propagates through the pipe as a pressure wave, and at this time, a sudden pressure fluctuation (surge pressure) may occur. In the control method according to this embodiment, under such a situation, the calculation of the work load L1 based on the monitoring target is stopped from the beginning, so that it is possible to avoid a situation where the work load L1 calculated based on the boom pressure, etc. deviates from the actual work load L1.

[0076] As a result, the control method according to this embodiment has the advantage that it is easy to improve the reliability of the work load L1 to be determined. Hereinafter, the control method will be described in more detail.

[0077] In this embodiment, the working load L1 calculated by calculation is displayed on the display device 2 to be presented to the user (operator). That is, the output processing unit 14 of the control system 1 outputs the working load L1 calculated by the calculation processing unit 12 to the display device 2, and causes the display device 2 to display the working load L1. Various modes are possible for displaying the working load L1 on the display device 2, and for example, the working load L1 may be displayed numerically or as a graph. The working load L1 may also be displayed by displaying a comparison result between the working load L1 (suspension load) and the rated load. That is, the display device 2 may display the working load L1 as a percentage of the rated load, or whether the working load L1 exceeds the rated load.

[0078] The control system 1 has two operating states: a steady state in which the calculation processor 12 determines the work load L1 by calculation, and a calculation pause state in which the calculation of the work load L1 is paused as described above.

[0079] In the steady state, the calculation processing unit 12 calculates the work load L1 periodically, for example, at a predetermined calculation cycle (for example, several hundred ms), and records the calculation results in memory as needed. Then, the output processing unit 14 outputs the work load L1 calculated by the calculation processing unit 12 as needed. As a result, the work load L1 displayed on the display device 2 is updated as needed, and the work load L1 is displayed in real time. Therefore, when there is a change in the work load L1, the work load L1 displayed on the display device 2 also changes.

[0080] On the other hand, in the calculation pause state, the calculation processing unit 12 does not calculate the work load L1. Therefore, the work load L1 displayed on the display device 2 is not updated, and the work load L1 is not displayed in real time. Therefore, even if there is a change in the work load L1, the work load L1 displayed on the display device 2 does not change.

[0081] In the control system 1 according to this embodiment, when the calculation is paused, a fixed value is output as the work load L1. Therefore, even when the calculation is paused, the work load L1 is displayed on the display device 2. However, the work load L1 displayed on the display device 2 at this time is a fixed value and does not change even if the actual work load L1 changes.

[0082] That is, in a computation pause state in which the computation processor 12 pauses computation of the work load L1, the work load L1 is fixed to a certain value (fixed value). This makes it possible to prevent the work load L1 from changing based on the monitored object in a situation in which fluctuations are likely to occur in the pressure (boom pressure) of the hydraulic cylinder 44 for driving the boom 332, which is included in the monitored object, such as when the operation of the boom 332 is suddenly stopped (at the time of sudden stop) during lifting work.

[0083] Here, the fixed value is a value determined from the history of the work load L1. In this embodiment, as an example, the work load L1 determined by calculation in the calculation processing unit 12 immediately before the steady state transitions to the calculation pause state, that is, the "previous value" of the work load L1, from the history of the work load L1 recorded in the memory, is used as the fixed value. As a result, in the calculation pause state, a fixed value determined from the history of the work load L1, such as the previous value, is output as the work load L1 and displayed on the display device 2.

[0084] Therefore, even in the calculation pause state, a completely random work load L1 is not output, but a fixed value based on the history of the work load L1 calculated by calculation before the transition to the calculation pause state is output as the work load L1. As a result, there is an advantage in that it is easy to improve the reliability of the work load L1.

[0085] Here, the objects to be monitored include the pressure of the cylinder operated by the working fluid. In the present embodiment, as an example, the objects to be monitored include the bottom pressure of the hydraulic cylinder 44 for driving the boom 332. With regard to the pressure of such a cylinder (hydraulic cylinder 44), a pressure fluctuation (surge pressure) may occur, for example, when the operation of the boom 332 is suddenly stopped (at the time of sudden stop).

[0086] Therefore, for example, when a specific operating state in which such pressure fluctuations may occur is detected, the work load L1 calculated by the calculation based on the monitored object is likely to deviate from the actual work load L1. In the control method according to the present embodiment, under such circumstances, the calculation of the work load L1 based on the monitored object is stopped from the beginning, so that it is possible to prevent the work load L1 calculated by the calculation based on the monitored object from deviating from the actual work load L1.

[0087] Further, the specific operation state is detected based on the acceleration applied to a specific part of the work machine 3. Specifically, in the present embodiment, as an example, the specific operation state includes a sudden stop and a sudden start of the work implement 33. For example, a sudden stop of the work implement 33 can be detected based on an angular acceleration obtained by further applying a differential operation to an angular velocity obtained by performing a differential operation on the boom angle measured by the boom angle sensor 52. In other words, when the angular acceleration (acceleration) applied to the boom 332, which is an example of a specific part of the work machine 3, exceeds a judgment threshold value, it is possible to detect a sudden stop of the boom 332. Similarly, a sudden start of the work implement 33 can also be detected based on the angular acceleration (acceleration) of the boom 332.

[0088] In a specific operating state detected based on such acceleration, as described above, fluctuations are likely to occur in the monitored object, such as pressure fluctuations (surge pressure) in the bottom pressure of the hydraulic cylinder 44 for driving the boom 332. When a specific operating state in which such pressure fluctuations may occur is detected, the work load L1 calculated based on the monitored object is likely to deviate from the actual work load L1. In the control method according to this embodiment, under such circumstances, the calculation of the work load L1 based on the monitored object is stopped from the start, so that it is possible to prevent the work load L1 calculated based on the monitored object from deviating from the actual work load L1.

[0089] Furthermore, in this embodiment, the calculation pause state continues at least while the specific operation state continues. That is, the pause processing unit 13 transitions (from the steady state) to the calculation pause state when it detects a specific operation state of the work machine 3, and thereafter maintains the calculation pause state at least as long as the specific operation state continues. For example, if the calculation pause state is transitioned to when a sudden stop of the work machine 33 is detected as a specific operation state, the calculation pause state is maintained at least until a sudden stop of the work machine 33 is no longer detected.

[0090] This makes it possible to prevent the work load L1 from changing based on the monitored object in a situation where fluctuations are likely to occur in the pressure (boom pressure) of the hydraulic cylinder 44 for driving the boom 332, which is included in the monitored object, such as when operation of the boom 332 is suddenly stopped (sudden stop) during lifting work.

[0091] On the other hand, in this embodiment, when the specific operation state is resolved, a transition is made from the calculation pause state to the steady state. In other words, the pause processing unit 13 transitions to the calculation pause state while detecting the specific operation state of the work machine 3, and then ends the calculation pause state and transitions to the steady state when the specific operation state is resolved.

[0092] Furthermore, as another example, the calculation pause state may not be changed to the steady state simply by the elimination of the specific operation state, but may be terminated and changed to the steady state when a return operation state different from the specific operation state is detected. Specifically, for example, when the boom 332 suddenly decelerates and stops during a hoisting operation, if the sudden stop (sudden deceleration and stop) is detected as a specific operation state, the pause processing unit 13 continues the calculation pause state while detecting the specific operation state. In this case, even if it is determined that the specific operation state is eliminated when the boom 332 completely stops and the angular acceleration (acceleration) applied to the boom 332 becomes equal to or less than the judgment threshold, the steady state is not changed by itself. In short, the calculation pause state is terminated and changed to the steady state only when an operation state different from the specific operation state, which is determined as a return operation state, such as (re)operation of the boom 332, is detected.

[0093] In this way, in the control method according to the present embodiment, when a specific operation state is detected and the control method transitions to a calculation pause state, the calculation pause state may be continued until a return operation state different from the specific operation state is detected. This makes it possible to more reliably prevent the work load L1 from changing based on the monitored object in a situation where the pressure (boom pressure) of the hydraulic cylinder 44 for driving the boom 332, which is included in the monitored object, is likely to fluctuate, for example, when the operation of the boom 332 is suddenly stopped (at the time of sudden stop) during lifting work.

[0094] The control method according to the present embodiment further includes terminating the calculation pause state when the calculation pause state continues for a timeout period. That is, after transitioning to the calculation pause state (from the steady state), the pause processing unit 13 forcibly terminates the calculation pause state and transitions to the steady state when a predetermined timeout period has elapsed. This makes it possible to avoid the calculation of the work load L1 being paused for a long period of time.

[0095] FIG. 5 is an explanatory diagram that diagrammatically illustrates an overview of the control method according to this embodiment.

[0096] 5, while in the steady state ST1, the calculation processor 12 calculates the work load L1 based on the monitored object to update the work load L1 from time to time. Then, when an operation to stop the operation of the boom 332 is performed and a condition C1 is satisfied that the angular acceleration of the boom 332 is equal to or less than the judgment threshold value or the boom 332 is in operation, the steady state continues.

[0097] On the other hand, when the boom 332 suddenly stops, an operation to stop the movement of the boom 332 is performed, and condition C2 is satisfied that the angular acceleration of the boom 332 exceeds the judgment threshold, the pause processing unit 13 transitions from the steady state ST1 to a calculation pause state ST2. During the calculation pause state ST2, the calculation processing unit 12 pauses the calculation (update) of the work load L1 based on the monitored object, and the work load L1 is held as the previous value, that is, the history of the work load L1 calculated by the calculation immediately before transitioning to the calculation pause state ST2.

[0098] Then, in the calculation pause state ST2, if a condition C3 is satisfied that the boom 332 moves or a timeout time has elapsed, the calculation pause state ST2 is shifted to the steady state ST1.

[0099] Furthermore, in this embodiment, the specific operating state includes the traveling state of the work machine 3. With regard to the traveling state, it is possible to detect vibrations that occur during traveling based on acceleration detected by an acceleration sensor or the like.

[0100] In other words, in the control method according to this embodiment, even when the work machine 3 is in a traveling state in which the monitored object is likely to become unstable due to vibration of the machine body 30, the calculation of the work load L1 based on the monitored object is paused, thereby making it possible to avoid a situation in which the work load L1 calculated by the calculation based on the monitored object deviates from the actual work load L1.

[0101] In this embodiment, the specific operation state includes an independent operation state of the arm 333 (an arm independent operation state). That is, the work machine 33 has a boom 332 and an arm 333 supported at the tip of the boom 332. The specific operation state includes an arm independent operation state in which the arm 333 is driven while the boom 332 is fixed. That is, even in an arm independent operation state in which only the arm 333 of the boom 332 and the arm 333 is operating, the pause processing unit 13 transitions to a calculation pause state as a specific operation state. The arm independent operation can be detected, for example, based on the boom angle measured by the boom angle sensor 52 and the arm angle measured by the arm angle sensor 53.

[0102] That is, in an arm-only operating state in which only the arm 333 of the boom 332 and arm 333 is operating, the bottom pressure of the hydraulic cylinder 44 for driving the boom 332 may not be a value corresponding to the work load L1, and therefore, in this embodiment, this situation is excluded from the calculation of the work load L1. Therefore, it is possible to avoid a situation in which the work load L1 calculated based on the monitored object deviates from the actual work load L1.

[0103] Incidentally, when the calculation processing unit 12 calculates the working load L1, it would normally measure the pressure on the rod side as well as the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332, and calculate the thrust of the hydraulic cylinder 44 from these two pressures. However, in this embodiment, a rod pressure sensor for measuring the pressure on the rod side of the hydraulic cylinder 44 for driving the boom 332 is not provided, and the working load L1 is calculated by a one-sensor method using one pressure sensor (bottom pressure sensor 51). Specifically, the calculation processing unit 12 performs a differential operation on the boom angle measured by the boom angle sensor 52 to calculate the angular velocity of the boom 332, and estimates the rod pressure based on the angular velocity. As a result, even with the one-sensor method using one pressure sensor (bottom pressure sensor 51), it is possible to accurately calculate the working load L1.

[0104] Here, when the boom 332 is in operation, the balance of forces is lost, and the estimation accuracy of the rod pressure decreases, which may decrease the calculation accuracy of the work load L1. Therefore, the calculation processing unit 12 performs correction so as to suppress the deviation of the rod pressure.

[0105] Specifically, when the boom 332 is raised, there is a correlation that is approximated by a quadratic curve between the angular velocity of the boom 332 and the pressure (rod pressure) on the rod side of the hydraulic cylinder 44 for driving the boom 332. Therefore, in this embodiment, when the boom 332 is raised, it is possible to estimate the rod pressure from the angular velocity of the boom 332 based on the correlation, for example, by mapping the correlation.

[0106] On the other hand, when the boom 332 is stationary or lowered, there is a linear correlation between the angular velocity of the boom 332 and the pressure (rod pressure) on the rod side of the hydraulic cylinder 44 for driving the boom 332. Therefore, in this embodiment, when the boom 332 is stationary or lowered, it is possible to estimate the rod pressure from the angular velocity of the boom 332 based on this correlation.

[0107] In this way, the work load L1 is calculated by adding the correction value to the object to be monitored. In this embodiment, the correction value is a coefficient that indicates the correlation between the angular velocity of the boom 332 and the rod pressure, and the work load L1 is calculated using the rod pressure calculated by adding the coefficient to the angular velocity of the boom 332 as the object to be monitored. When the operation of the work implement 33 satisfies a specific condition, the correction value is determined according to the speed of the work implement 33.

[0108] The "specific condition" in the present disclosure is, for example, the lifting operation of the boom 332. That is, when the boom 332 is lifted, the correction value is changed according to the lifting speed of the boom 332 based on the correlation approximated by the quadratic curve, and the rod pressure is estimated from the angular speed of the boom 332 using the correction value. In short, it becomes possible to correct the imbalance in the calculated balance between the work load L1 and the bottom pressure, which increases as the lifting speed of the work implement 33 increases. This makes it possible to accurately determine the work load L1 even with a one-sensor method using one pressure sensor (bottom pressure sensor 51).

[0109] Furthermore, when the operation of the work implement 33 does not satisfy the specific condition, the correction value is determined regardless of the speed of the work implement 33. In other words, when the operation of the work implement 33 does not satisfy the specific condition, such as when the boom 332 is stationary or lowering, the correction value becomes a predetermined constant value. This makes it possible to accurately determine the work load L1 even in a one-sensor system using one pressure sensor (bottom pressure sensor 51).

[0110] In addition, in the control method according to the present embodiment, a time lag is provided between the timing of calculating the work load L1 to be displayed on the display device 2 and the timing of detecting (determining) the specific operation state. In fact, the change in the bottom pressure of the hydraulic cylinder 44 for driving the boom 332 occurs prior to the change in the boom angle and the arm angle. In other words, when operating the work implement 33, after the change in the bottom pressure, the work implement 33 operates and the boom angle and the arm angle change. Therefore, at a certain time point (t), a specific operation state such as a sudden stop of the boom 332 is detected based on the boom angle measured by the boom angle sensor 52 and the arm angle measured by the arm angle sensor 53 at the time point (t). On the other hand, the work load L1 displayed on the display device 2 at the time point (t) is the calculation result at the time point (t-1) one cycle (calculation cycle) before the time point (t).

[0111] This reduces the effect of the response time difference between the pressure of the hydraulic cylinder 44 and the boom angle and arm angle on the calculated work load L1. However, this is not limiting, and the work load L1 calculated at a timing several cycles (calculation cycles) before the timing at which the specific operating state is detected may be displayed on the display device 2 in accordance with the response time difference between the pressure of the hydraulic cylinder 44 and the boom angle and arm angle.

[0112] Next, the main process flow of the control method according to this embodiment will be described with reference to the flowchart of FIG.

[0113] As a premise, when the prime mover of the work machine 3 is started (the ignition is turned on), the control system 1 starts the processing from step S1 onwards, and thereafter repeatedly executes the processing from step S1 to S5.

[0114] In step S1, since the steady state is reached, the calculation processing unit 12 of the control system 1 obtains the working load L1 (suspended load) by calculation based on the monitored object related to the work machine 3, and updates the working load L1 as necessary. In step S2, the pause processing unit 13 of the control system 1 determines whether the operating state of the work machine 3 is in a specific operating state (such as a sudden stop, a sudden start, or a traveling state of the work implement 33). If a specific operating state is detected (S2: Yes), the pause processing unit 13 transitions to a calculation pause state, pauses the calculation of the working load L1, and holds the previous time as the working load L1 (S3). On the other hand, if a specific operating state is not detected (S2: No), the control system 1 returns the process to step S1.

[0115] In step S4, the pause processing unit 13 of the control system 1 determines whether or not the operating state of the work machine 3 has ended the specific operating state. When the specific operating state has ended (S4: Yes), the control system 1 returns the process to step S1. On the other hand, when the specific operating state has not ended (S4: No), the control system 1 determines whether or not a timeout time has elapsed (S5). When the timeout time has elapsed (S5: Yes), the control system 1 returns the process to step S1. On the other hand, when the timeout time has not elapsed (S5: No), the control system 1 returns the process to step S3.

[0116] The control system 1 repeatedly executes the processes of steps S1 to S5 described above. However, the flowchart shown in Fig. 6 is merely an example, and processes may be added or omitted as appropriate, and the order of processes may be changed as appropriate.

[0117] [4] Variations Below, we will list some modified examples of the embodiment 1. The modified examples explained below can be applied in appropriate combinations.

[0118] The control system 1 in the present disclosure includes a computer system. The computer system is mainly composed of one or more processors and one or more memories as hardware. The processor executes a program recorded in the memory of the computer system, thereby realizing the functions of the control system 1 in the present disclosure. The program may be pre-recorded in the memory of the computer system, may be provided through a telecommunication line, or may be recorded and provided in a non-transitory recording medium such as a memory card, an optical disk, or a hard disk drive that can be read by the computer system. In addition, some or all of the functional units included in the control system 1 may be configured with electronic circuits.

[0119] Furthermore, it is not essential for the control system 1 that at least some of the functions of the control system 1 are concentrated in one housing, and the components of the control system 1 may be distributed across multiple housings. Conversely, in the first embodiment, functions distributed across multiple devices (e.g., the control system 1 and the display device 2) may be concentrated in one housing. Furthermore, at least some of the functions of the control system 1 may be realized by the cloud (cloud computing) or the like.

[0120] Furthermore, the operation lever of the operation device 35 may be an electric operation device configured to accept various operations by a user (operator) by outputting an electric signal (operation signal) in response to the operation of the user to the control system 1. In this case, the control system 1 can control the hydraulic actuator, for example, by controlling a control valve (solenoid valve) provided in place of the remote control valve 45 in response to the operation of the operation device 35 (operation lever).

[0121] The display device 2 is not limited to a dedicated device, and may be, for example, a general-purpose terminal such as a laptop computer, a tablet terminal, or a smartphone. Furthermore, the display unit 23 is not limited to a mode that directly displays a display screen, such as a liquid crystal display or an organic EL display, and may be configured to display a display screen by projection, such as a projector.

[0122] Furthermore, the actuators of each part of the machine body 30 are not limited to hydraulic actuators, but may be, for example, pneumatic actuators driven by air pressure such as compressed air, or electric actuators driven by a power supply, or a combination of these.

[0123] Furthermore, it is not essential that the one-sensor system uses one pressure sensor (bottom pressure sensor 51); in addition to the bottom pressure sensor 51, a rod pressure sensor that measures the pressure on the rod side of the hydraulic cylinder 44 for driving the boom 332 may be provided.

[0124] (Embodiment 2) The control method according to this embodiment differs from the control method according to the first embodiment in that it includes control for preventing overturning of the work machine 3 based on the work load L1. Hereinafter, common reference symbols are used for configurations similar to those in the first embodiment, and descriptions thereof will be omitted as appropriate.

[0125] That is, in this embodiment, the output processing unit 14 outputs the work load L1 (suspension load) calculated by the calculation processing unit 12 in a form usable for controlling each part of the machine body 30 to prevent tipping over (anti-tip control). When a specific operating state is detected and a transition is made to a calculation pause state, the work load L1 (previous value) calculated immediately before that is used for the anti-tip control of the work machine 3.

[0126] Specifically, the control system 1 uses the work load L1 to identify the center of gravity position or ZMP (Zero Moment Point) of the machine body 30, and thereby executes anti-tip control to control the attitude of the work machine 3 to prevent tipping of the machine body 30. The work load L1 used at this time is determined by calculation in the calculation processing unit 12 in a steady state, and is the work load L1 determined immediately before in a calculation pause state.

[0127] This prevents the center of gravity position or ZMP of the machine body 30 from being identified accurately due to an inability to calculate an accurate work load L1 caused by, for example, pressure fluctuations in the hydraulic cylinder 44 due to disturbances of large angular acceleration, leading to improved accuracy in the control of the prevention of tipping over of the work machine 3.

[0128] Furthermore, the work machine 3 according to this embodiment is equipped with a rod pressure sensor that measures the pressure on the rod side of the hydraulic cylinder 44 for driving the boom 332, in addition to the bottom pressure sensor 51 that measures the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332. In other words, the calculation processing unit 12 is able to calculate the work load L1 using both the bottom pressure and the rod pressure.

[0129] In this embodiment, when a specific operating state is detected, it is preferable to pause the calculation of the working load L1 by the calculation processing unit 12 until at least a specified time (for example, several hundred ms) has elapsed. In other words, even if the specific operating state is resolved in the calculation pause state, if the specified time has not elapsed, the system waits until the specified time has elapsed before transitioning to the steady state. Furthermore, if the specific operating state continues after the specified time has elapsed, the specified time is added, and transition to the steady state is only made when the specific operating state has been resolved at the next specified time elapsed.

[0130] As a result, for example, during a period in which the calculation error becomes relatively large immediately after a large angular acceleration is input, the calculation of the work load L1 by the calculation processor 12 is paused, thereby making it possible to suppress the calculation error of the work load L1 to a small value. The configuration according to the second embodiment can be adopted in appropriate combination with the various configurations (including modified examples) described in the first embodiment.

[0131] [Appendix to the invention] The following will provide an overview of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0132] <Appendix 1> determining, by calculation, a work load applied to a specific portion of a work machine when a work is performed using a work implement of the work machine, based on a monitoring target related to the work machine; transitioning to a calculation pause state in which calculation of the work load is paused when a specific operating state of the work machine is detected; A method for controlling a work machine.

[0133] <Appendix 2> The computation pause state is continued at least while the specific operation state continues. 2. A method for controlling a work machine as described in claim 1.

[0134] <Appendix 3> The monitored object includes a pressure of a cylinder operated by a hydraulic fluid. 3. A method for controlling a work machine according to claim 1 or 2.

[0135] <Appendix 4> The specific operating state is detected based on an acceleration applied to a specific part of the work machine. A control method for a work machine according to any one of appendices 1 to 3.

[0136] <Appendix 5> The work load is calculated by adding a correction value to the monitored object, When the operation of the work machine satisfies a specific condition, the correction value is determined according to the speed of the work machine. A control method for a work machine according to any one of appendices 1 to 4.

[0137] <Appendix 6> When the operation of the work machine does not satisfy the specific condition, the correction value is determined regardless of the speed of the work machine. 6. A method for controlling a work machine as described in appendix 5.

[0138] <Appendix 7> The specific operating state includes a traveling state of the work machine. A control method for a work machine according to any one of appendices 1 to 6.

[0139] <Appendix 8> The work machine has a boom and an arm supported on a tip portion of the boom, The specific operation state includes an arm alone operation state in which the boom is fixed and the arm is driven. A control method for a work machine according to any one of appendices 1 to 7.

[0140] <Appendix 9> In the calculation pause state, a fixed value is output as the work load. A control method for a work machine according to any one of appendices 1 to 8.

[0141] <Appendix 10> The fixed value is a value determined from the history of the work load. 10. A method for controlling a work machine as described in Supplementary Note 9.

[0142] <Appendix 11> and performing a tipping prevention control of the work machine based on the work load. A control method for a work machine according to any one of appendices 1 to 10.

[0143] <Appendix 12> and terminating the computation pause state if the computation pause state continues for a timeout period. A control method for a work machine according to any one of appendices 1 to 11.

[0144] <Appendix 13> When the specific operation state is detected and the operation state transitions to the calculation pause state, the calculation pause state is continued until a return operation state different from the specific operation state is detected. A control method for a work machine according to any one of appendices 1 to 12.

[0145] <Appendix 14> A method for controlling a work machine according to any one of appendices 1 to 13, A control program for a work machine for execution by one or more processors. [Explanation of symbols]

[0146] 1. Control system for work machines 3. Work Machinery 12 Processing unit 13. Pause Processing Unit 30 Aircraft 33 Work equipment 332 Boom 333 Arm L1 Working load

Claims

1. When performing work using a working machine of a work machine, obtaining, by calculation, a work load applied to a specific part of the work machine based on a monitoring target related to the work machine; When detecting a specific operating state of the work machine, shifting to an operation suspension state in which the calculation of the work load is suspended. A control method for a work machine.

2. At least during the continuation of the specific operating state, the operation suspension state is continued. The control method for a work machine according to Claim 1.

3. The monitoring target includes the pressure of a cylinder operated by a working fluid. The control method for a work machine according to Claim 1 or 2.

4. The specific operating state is detected based on an acceleration applied to a specific part of the work machine. The control method for a work machine according to Claim 1 or 2.

5. The work load is obtained by taking into account a correction value for the monitoring target. When the operation of the work machine satisfies specific conditions, the correction value is determined according to the speed of the work machine. The control method for a work machine according to Claim 1 or 2.

6. When the operation of the work machine does not satisfy the specific conditions, the correction value is determined regardless of the speed of the work machine. The control method for a work machine according to Claim 5.

7. The specific operating state includes the traveling state of the work machine. The control method for a work machine according to Claim 1 or 2.

8. The work machine has a boom and an arm supported at the tip of the boom. The specific operating state includes an arm-alone operation state in which the arm is driven with the boom fixed. The control method for a work machine according to Claim 1 or 2.

9. In the operation suspension state, a fixed value is output as the work load. The control method for a work machine according to Claim 1 or 2.

10. The fixed value is a value obtained from the history of the work load. The control method for a work machine according to Claim 9.

11. Further comprising performing anti-tip control of the work machine based on the work load. The control method for a work machine according to Claim 1 or 2.

12. Further comprising ending the operation suspension state when the operation suspension state continues for a timeout period. The control method for a work machine according to Claim 1 or 2.

13. When the specific operating state is detected and the operation suspension state is entered, the operation suspension state is continued until a return operation state different from the specific operating state is detected. The control method of the working machine according to claim 1 or 2.

14. A control program for a working machine for causing one or more processors to execute the control method of the working machine according to claim 1 or 2.

15. An arithmetic processing unit that obtains, by arithmetic operation, a working load applied to a specific part of the working machine during work using a working device of the working machine, based on a monitoring target related to the working machine; A pause processing unit that, when a specific operating state of the working machine is detected, shifts to a pause operation state in which the arithmetic operation of the working load by the arithmetic processing unit is paused. A control system for a working machine.

16. A working machine comprising the control system for a working machine according to claim 15 and a machine body. A working machine.

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