Work machine control method, work machine control program, work machine control system, and work machine

Abstract

To provide a work machine control method, a work machine control program, a work machine control system, and a work machine with which the work machine is easy to be stably operated.SOLUTION: A control method of a work machine 3 includes performing fall prevention control of performing operation regulation of the work machine 3 on the basis of a fall possibility estimated from a state of the work machine 3. A control method of the work machine 3 further includes performing sensibility regulation control of reducing a response sensibility of operation regulation with respect to the fall possibility in the fall prevention control to be lower when the fall possibility is decreased than that when the fall possibility is increased.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control method for a work machine having a function of preventing lights from turning on in the work machine, a control program for a work machine, a control system for a work machine, and a work machine. [Background technology]

[0002] As a related technology, a work machine (shovel) is known that includes a traveling section (base), a rotating section (swivel body) rotatably mounted on the traveling section, and a work implement (attachment) that is attached to the rotating section, rotates together with the rotating section, and has a variable turning radius (see, for example, Patent Document 1).

[0003] In a work machine according to the related art, a control device determines whether the orientation of the work machine (relative to a slope) is within the tipping danger zone. If the control device determines that the orientation of the work machine is within the tipping danger zone, it decelerates the drive unit (swing electric motor) that rotates the swivel unit based on a forced deceleration command. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-189767 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned related technology, the forced deceleration command is turned on / off as the rotating unit turns, which can cause the rotation speed of the rotating unit to fluctuate regardless of the operator's intentions, making the operation of the rotating unit unstable (jerky).

[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 facilitate stable operation of the work machine. [Means for solving the problem]

[0007] A method for controlling a work machine according to one aspect of the present invention includes executing anti-tip control that restricts the operation of the work machine based on the possibility of tipping over estimated from the state of the work machine, and executing sensitivity restriction control that makes the response sensitivity of the operation restriction to the possibility of tipping over in the anti-tip control lower when the possibility of tipping over decreases than when the possibility of tipping over increases.

[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 an anti-toppling processing unit and a sensitivity restriction processing unit. The anti-toppling processing unit executes anti-toppling control that restricts the operation of the work machine based on the likelihood of tipping estimated from the state of the work machine. The sensitivity restriction processing unit lowers the response sensitivity of the operation restriction to the likelihood of tipping in the anti-toppling control when the likelihood of tipping decreases compared to when the likelihood of tipping increases.

[0010] A work machine according to one aspect of the present invention includes the work machine control system and a machine body. [Effects 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 make it easy to operate a work machine stably. [Brief explanation 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. [Figure 2] FIG. 2 is a schematic diagram showing a hydraulic circuit and the like of the work machine according to the first embodiment. [Figure 3] FIG. 3 is a schematic plan view of the work machine according to the first embodiment. [Figure 4] FIG. 4 is a schematic plan view of the work machine according to the first embodiment. [Figure 5] FIG. 5 is a schematic diagram showing the relationship between the evaluation value and speed scaling used in the control method for a work machine according to the first embodiment. [Figure 6] FIG. 6 is a schematic diagram showing a specific example of the lighting state of the indicator lamp of the work machine according to the first embodiment. [Figure 7] FIG. 7 is a schematic diagram showing a specific example of the display state of the display unit of the work machine according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of the operation of the work machine control system according to the first embodiment. [Figure 9] FIG. 9 is a schematic diagram showing the relationship between the swing angle, the evaluation value, and the speed scaling in the control method for a work machine according to the first embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of the operation of the work machine control system according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following description will discuss preferred embodiments of the present invention with reference to the accompanying drawings. The preferred embodiments are merely examples of the present invention and are not intended to limit the technical scope of the present invention.

[0014] (Embodiment 1) [1] Overall structure As shown in Figure 1, the work machine 3 according to this embodiment is equipped with a traveling section 31, a swivel section 32, and a work implement 33 on a machine body 30. The work machine 3 is further equipped with a work machine control system 1 (hereinafter simply referred to as the "control system 1") as shown in Figure 2. In addition, the machine body 30 is further equipped with a display device 2, an operating device 35, an indicator light 36, an attitude detection device 37, etc.

[0015] In this disclosure, the term "work machine" refers to various types of work machinery, and examples include work vehicles such as backhoes (including hydraulic excavators, mini excavators, etc.), wheel loaders, and carriers. The work machine 3 is equipped with a work implement 33 configured to be able to perform one or more tasks. The work machine 3 is not limited to a "vehicle," and may be, for example, a work vessel, a work air vehicle such as a drone or multicopters, etc. Furthermore, the work machine 3 is not limited to a construction machine (construction equipment), and may be, for example, an agricultural machine (farm equipment) such as a rice transplanter, tractor, or combine harvester. In this embodiment, unless otherwise specified, the work machine 3 is a riding-type backhoe that is capable of performing tasks such as lifting (crane work), excavation, leveling, trench digging, and loading.

[0016] Furthermore, in this embodiment, for ease 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-to-rear direction D2 and the left-to-right direction D3 are defined based on the direction as seen by the user (operator) aboard the work machine 3 (the driving unit 321 thereof). In other words, all directions used in this embodiment are directions defined based on the machine body 30 of the work machine 3, with the direction in which the machine body 30 moves when the work machine 3 moves forward being "forward" and the direction in which the machine body 30 moves when the work machine 3 moves backward being "rear". Similarly, the direction in which the front end of the machine body 30 moves when the work machine 3 turns right being "rightward", and the direction in which the front end of the machine body 30 moves when the work machine 3 turns left being "leftward". However, these directions are not intended to limit the direction in which the work machine 3 is used (the direction in 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 (light oil in this case) 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 hydraulic motors 43, 45 and hydraulic cylinder 44, etc.) in 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 from combustion or steam, or electricity, into mechanical power (power), and supplies power (hydraulic 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) aboard 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 operator's operation, and the work machine 3 operates in accordance with the operator's operation. 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, or an electric motor (electric motor), or a hybrid power source including an internal combustion engine and an electric motor.

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

[0020] Here, the driving section 321 of the machine body 30 is equipped with a display device 2, an operating device 35, etc., and the user can operate the operating 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 on the display device 2 information related to the operating state of the work machine 3 that is necessary for operating the operating device 35.

[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 traveling hydraulic motor 43 (hydraulic actuator) for driving the crawlers 311.

[0022] The swivel unit 32 is located above the travel unit 31 and is configured to be swivelable relative to the travel unit 31 about a rotation axis along the up-down direction D1. The swivel unit 32 has a hydraulic motor 45 (see FIG. 2) and the like as a hydraulic actuator for swivel. In addition to a driving unit 321, the swivel unit 32 is equipped with a prime mover, a hydraulic pump 41 and the like. Furthermore, a boom bracket 322 to which a work implement 33 is attached is provided at the front end of the swivel unit 32.

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

[0024] The work implement 33 further includes a boom 332, an arm 333, and a hydraulic actuator (including a hydraulic cylinder 44, a 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 (swivel section 32). Specifically, the boom 332 is rotatably supported by the boom bracket 322 around a horizontal rotation axis. 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. The arm 333 is supported by the boom 332 so as to be rotatable about a rotation axis that extends in the horizontal direction.

[0027] Particularly in this embodiment, the work implement 33 has an articulated structure in which the boom 332 and the arm 333 are configured to be independently rotatable. In other words, by each of the boom 332 and the arm 333 rotating about a horizontal rotation axis, the articulated work implement 33 including the boom 332 and the arm 333 can be extended or folded as a whole.

[0028] The work implement 33 operates by receiving power from a prime mover as a power source. Specifically, the prime mover drives a hydraulic pump 41, and hydraulic oil is supplied from the hydraulic pump 41 to hydraulic actuators (hydraulic cylinder 44, etc.) of the work implement 33, thereby operating each part of the work implement 33 (bucket 331, boom 332, and 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 lifting work. 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 lifting work in addition to excavation work using the bucket 331. For this reason, the work implement 33 is equipped with a hook for performing lifting work.

[0030] When performing a lifting operation, the work 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. Furthermore, by rotating the swivel unit 32 with the load suspended from the hook provided at the tip of the work machine 33, the load can be rotated around the rotation axis of the swivel unit 32.

[0031] When performing a lifting operation, a load corresponding to the weight of the lifted load is applied to the hook and bucket 331 as a "lifting load." The lifting load is an example of a working load. In this disclosure, the "working load" refers to a load that is 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 earth and sand when loading earth and sand or the like. In short, during a lifting operation, a "lifting load" corresponding to the weight of the lifted load is applied as a working load to the bucket 331, which is a "specific part" of the work machine 3. On the other hand, during loading earth and sand or the like, a "live load" corresponding to the weight of the earth and sand or the like is applied as a working load to the bucket 331, which is a "specific part" of the work machine 3.

[0032] Like 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 45 of the swivel unit 32, etc.

[0033] The actuators (hydraulic actuators including hydraulic motors 43, 45 and hydraulic cylinder 44 in this embodiment) provided in various parts 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, in response to operation of the operation device 35 by the user (operator), 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.

[0034] Fig. 2 schematically shows the hydraulic circuit and electrical circuit (electrical connection relationships) 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 electrical signal paths.

[0035] As shown in FIG. 2, the work machine 3 is equipped with a hydraulic pump 41, a hydraulic motor 43 for traveling (not shown in FIG. 2), a hydraulic cylinder 44 (not shown in FIG. 2), a hydraulic motor 45 for swinging, and a prime mover, as well as a pilot pump 42, a remote control valve 46, a first control valve 471, a cutoff switch 461, a cutoff lever 462, a directional control valve (control valve) 48, and the like.

[0036] Hydraulic oil from a hydraulic pump 41 driven by a prime mover is supplied to a hydraulic motor 43 of the traveling section 31, a hydraulic motor 45 of the swivel section 32, a hydraulic cylinder 44 of the work implement 33, etc. This drives hydraulic actuators such as the hydraulic motors 43, 45 and the hydraulic cylinder 44.

[0037] Hydraulic actuators such as the hydraulic motors 43, 45 and the hydraulic cylinder 44 are provided with a pilot-type directional control valve 48 that can switch 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.

[0038] Here, for example, a remote control valve 46 is provided in a supply path of pilot oil to a directional control valve 48 corresponding to the hydraulic motor 45 of the swivel section 32. The remote control valve 46 outputs a swing operation command for the swivel section 32 in response to operation of the operating device 35 (operation lever). The swing operation command instructs the swing operation (left swing, right swing, etc.) of the swivel section 32. In addition, the flow rate of pilot oil supplied from the pilot pump 42 to the remote control valve 46 can be adjusted by a first control valve 471 and a second control valve 472.

[0039] The first control valve 471 and the second control valve 472 are both electromagnetic control valves (solenoid valves) and are inserted in series between the remote control valve 46 and the pilot pump 42. The first control valve 471 is connected to a power source via a cut-off switch 461 and operates in response to a current supplied from the power source. The second control valve 472 is connected to the control system 1 and operates in response to a control signal (supply current) from the control system 1. Here, the first control valve 471 and the second control valve 472 are (electromagnetic) proportional control valves, but are not limited to this and may be, for example, an on-off valve that can switch between opening and closing a flow path.

[0040] Both the first control valve 471 and the second control valve 472 open the flow path of pilot oil when they are in an energized state, that is, when current is supplied as a control signal, and block the flow path of pilot oil when they are in a de-energized state, that is, when current is cut off as a control signal. Therefore, when the supply current (control signal) to at least one of the first control valve 471 and the second control valve 472 is cut off, the hydraulic actuator (hydraulic motor 45, etc.) corresponding to the remote control valve 46 becomes inoperable, and the hydraulic actuator is forcibly stopped regardless of the operation of the operating device 35.

[0041] Furthermore, the control system 1 can adjust the flow rate of pilot oil supplied from the pilot pump 42 to the remote control valve 46, for example, by adjusting the valve opening of the second control valve 472. As an example, by narrowing the valve opening of the second control valve 472, it is possible to reduce the flow rate of pilot oil supplied from the pilot pump 42 to the remote control valve 46 and slow down the operating speed of the hydraulic actuator (hydraulic motor 45, etc.).

[0042] Similarly, a remote control valve is also provided in the supply path for pilot oil to the 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 operation of the operating device 35 (operation lever). The travel operation command instructs the traveling operation (forward or reverse, etc.) of the traveling unit 31. Furthermore, a remote control valve is also provided in the supply path for pilot oil to the directional control valve corresponding to the hydraulic cylinder 44 of the work implement 33. This remote control valve outputs a work operation command for the work implement 33 in response to operation of the operating device 35 (operation lever). The work operation command instructs the work implement 33 to deploy, retract, etc.

[0043] A first control valve 471 and a second control valve 472 are also inserted between these remote control valves and the pilot pump 42. Therefore, the flow rate of pilot oil supplied from the pilot pump 42 to these remote control valves can be adjusted by the second control valve 472, and the operating speeds of the traveling part 31 (the hydraulic motor 43 thereof) and the work implement 33 (the hydraulic cylinder 44 thereof) can also be controlled by the second control valve 472.

[0044] The cutoff switch 461 is linked to a cutoff lever 462. The cutoff lever 462 is disposed in the driving section 321 of the machine body 30, and receives operational input from a user (operator). In this embodiment, as an example, the cutoff lever 462 is operable in the up-down direction D1. When the cutoff lever 462 is in the "up position," which is the upper end position of its movable range, the cutoff switch 461 is "off," and when the cutoff lever 462 is in the "down position," which is the lower end position of its movable range, the cutoff switch 461 is "on." The cutoff switch 461 is connected to the control system 1, and the on / off state of the cutoff switch 461, i.e., the operational state of the cutoff lever 462, is monitored by the control system 1.

[0045] Therefore, when the cutoff lever 462 is in the "down position," the first control valve 471 is energized, and the hydraulic actuator (hydraulic motor 45, etc.) is driven by operation of the operation device 35. In contrast, when the cutoff lever 462 is in the "up position," the first control valve 471 is deenergized, and the hydraulic actuator is forcibly stopped without operation of the operation device 35. Therefore, to drive the hydraulic actuator (hydraulic motor 45, etc.), the user (operator) needs to operate the cutoff lever 462 to the "down position."

[0046] Furthermore, since the traveling unit 31 and the working unit 33 each operate when hydraulic oil is supplied from the hydraulic pump 41 to a hydraulic actuator (hydraulic motor 43, etc.), when the cutoff lever 462 is in the "raised position", the traveling unit 31 and the working unit 33 are also disabled. In other words, when the cutoff lever 462 is in the "raised position", the swivel unit 32, traveling unit 31, and working unit 33 are all forcibly disabled from driving.

[0047] In this embodiment, the state of the cutoff lever 462 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 462 when it is in the "down position", i.e., when the work machine 3 can be operated, is defined as the "unlocked state".

[0048] In short, when the cutoff switch 461 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. When the cutoff lever 462 is in the "raised position" and the cutoff switch 461 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 462 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.

[0049] The operation device 35 is disposed in the driving section 321 of the machine body 30, and is a user interface for receiving operation inputs from a user (operator). The operation device 35 includes, for example, an operation lever, and controls the remote control valve 46 in accordance with the amount of operation of the operation lever. This enables the operator to operate the remote control valve 46 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.

[0050] The indicator light 36 lights up (emits light) according to the operating state of the work machine 3. For example, as shown in FIG. 1 , the indicator light 36 is arranged on the swivel section 32, outside the driving section 321 (for example, to the right rear of the driving section 321). The indicator light 36 arranged in this manner mainly provides indications to people around the work machine 3.

[0051] In particular, in this embodiment, the indicator light 36 has a plurality of light-emitting elements 361, 362, and 363 that emit light in different colors, and these plurality of light-emitting elements 361, 362, and 363 can be made to emit light individually. The plurality of light-emitting elements 361, 362, and 363 are each realized using a light source such as a light-emitting diode. As an example, the indicator light 36 has a green light-emitting element 361, a yellow light-emitting element 362, and a red light-emitting element 363, and these three color light-emitting elements 361, 362, and 363 are made to emit light in accordance with the operating state of the work machine 3.

[0052] The attitude detection device 37 includes various sensors, such as an acceleration sensor, an angular velocity (gyro) sensor, a cylinder stroke sensor, a boom angle sensor, an arm angle sensor, and a pressure sensor, which are attached to various parts of the machine body 30. The attitude detection device 37 can detect the attitude of the machine body 30 based on the outputs of these various sensors. The attitude detection device 37 outputs the outputs of the various sensors or information related to the attitude of the machine body 30 detected from the outputs of these sensors to the control system 1.

[0053] For example, since the lengths of the boom 332 and the arm 333 are known, it is possible to determine the attitude (working attitude) of the work implement 33 by determining the boom angle and the arm angle. Furthermore, it is also possible to determine the working load (suspended load in this embodiment) acting on the tip end (hook 334 and bucket 331) of the work implement 33 by utilizing moment balance based on the working attitude and the pressure on the bottom side of the hydraulic cylinder 44 for driving the boom 332 measured by a pressure sensor.

[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 explained in more 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 receiving operation inputs from a user (operator) and outputting various information to the user. The display device 2 receives various operations from the user, for example, by outputting electrical signals in response to the user's operations. This allows the user (operator) to view the display screen displayed on the display device 2 and to operate the display device 2 as necessary.

[0056] 2, the display device 2 includes a control unit 21, an operation unit 22, and a display unit 23. The display device 2 is configured to be able to communicate with the control system 1, and is able to send and receive data to and from 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] The control unit 21 controls the display device 2 in accordance with data from the control system 1. Specifically, the control unit 21 outputs an electrical signal in response to a user operation received by the operation unit 22, and displays a display screen generated by the control system 1 on the display unit 23.

[0058] The operation unit 22 is a user interface for receiving operation inputs by a user (operator) on a display screen displayed on the display unit 23. The operation unit 22 receives various operations by the user, for example, by outputting an electrical signal in response to the user's operation. The operation unit 22 may also include a touch panel, an operation dial, etc.

[0059] The display unit 23 is a user interface for presenting information to a user (operator), such as a liquid crystal display or an organic EL display that displays various types of information. The display unit 23 presents various types of information to the user by displaying them.

[0060] In addition to the above-mentioned components, the machine body 30 further comprises 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 attachments of the work machine 33, and is made up of a device (mechanism) such as a PTO (Power take-off) for extracting power from the prime mover as power for driving the attachments made up of hydraulic equipment. Furthermore, the machine body 30 is equipped with various sensors (including cameras) for detecting objects to be detected in the monitoring area around the work machine 33, such as a camera that captures images of the area around the machine body 30.

[0061] [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 swivel section 32, the work implement 33, etc.). In this embodiment, the control system 1 is a component of the work machine 3, and together with the machine body 30, etc., constitutes the work machine 3. In other words, the work machine 3 according to this embodiment comprises at least the control system 1 and the machine body 30.

[0062] As shown in Fig. 2, the control system 1 includes an evaluation processing unit 11, a tip-over prevention processing unit 12, a suppression processing unit 13, a sensitivity restriction processing unit 14, and a presentation processing unit 15. 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 (evaluation processing 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 separately in multiple housings, or may be provided in a single housing.

[0063] The control system 1 is configured to be able to communicate with devices provided in various parts of the airframe 30. That is, at least the display device 2, the indicator light 36, the attitude detection device 37, the cut-off switch 461, the first control valve 471, and the second control valve 472 are connected to the control system 1. This allows the control system 1 to control the display device 2, the indicator light 36, the first control valve 471, and the second control valve 472, and to acquire outputs from the attitude detection device 37, etc. Here, the control system 1 may exchange various information (data) with each device directly or indirectly via a repeater or the like. The control system 1 and the devices provided in various parts of the airframe 30 can communicate with each other using a communication method such as CAN (Controller Area Network), for example.

[0064] The evaluation processing unit 11 performs evaluation processing to evaluate the possibility of tipping over of the work machine 3. In this disclosure, "possibility of tipping over" refers to the possibility of the work machine 3 (machine body 30) tipping over due to a sudden change in the center of gravity position of the work machine 3 (machine body 30) or the influence of inertial forces caused by a sudden operation of the traveling unit 31, swivel unit 32 or work implement 33 of the work machine 3. In other words, if the tipping possibility is low, the work machine 3 is in a stable state where it is unlikely to tip over, and the higher the tipping possibility, the more unstable the work machine 3 is where it is likely to tip over.

[0065] In this embodiment, as an example, the evaluation processing unit 11 evaluates (estimates) the possibility of tipping over from the state of the work machine 3 identified by the output of the attitude detection device 37. The "state" of the work machine 3 here means the current state of the work machine 3, and includes, for example, the attitude, movement direction, movement speed, etc. of the work machine 3. Furthermore, in this embodiment, the evaluation processing unit 11 evaluates the possibility of tipping over by calculating an evaluation value related to the possibility of tipping over.

[0066] The tipping prevention processing unit 12 executes tipping prevention control to prevent tipping of the machine body 30 of the work machine 3. Here, the tipping prevention processing unit 12 prevents tipping of the machine body 30 of the work machine 3 by restricting the operation of the work machine 3 based on the possibility of tipping evaluated by the evaluation processing unit 11. In other words, for example, when there is a high possibility of tipping, the tipping prevention processing unit 12 executes tipping prevention control to restrict (restrain) the operation of each part of the machine body 30 (travel unit 31, swivel unit 32, work implement 33, etc.).

[0067] As one example, the anti-toppling processing unit 12 restricts the operation of the work machine 3 by reducing the operating speed or setting an upper limit value for the operating speed for at least one of the traveling operation of the travel unit 31, the swing operation of the swivel unit 32, and the operation of the work implement 33. Alternatively, the anti-toppling processing unit 12 may restrict the operation of the work machine 3 by stopping the operation of at least one of the travel unit 31, the swing unit 32, and the work implement 33. Specifically, the anti-toppling processing unit 12 controls the second control valve 472 and throttles down the second control valve 472, thereby restricting the operation of individual drive units (hydraulic actuators) such as the hydraulic motor 43 of the travel unit 31, the hydraulic motor 45 of the swivel unit 32, and the hydraulic cylinder 44 of the work implement 33.

[0068] The suppression processing unit 13 executes suppression control that suppresses the anti-toppling control performed by the anti-toppling processing unit 12. Here, the suppression processing unit 13 suppresses the restriction of operation of the work machine 3 by the anti-toppling control when the evaluation value related to the possibility of tipping exceeds a threshold value. In this disclosure, "suppression" refers to processing that acts in some way to suppress the restriction of operation of the work machine 3. In other words, when the suppression processing is executed, the restriction of operation of the work machine 3 by the anti-toppling control is basically released or relaxed. Relaxation of the operation restriction is achieved, for example, by reducing the strength of the operation restriction. For example, if the operation speed has been reduced by the anti-toppling control, the suppression processing will release the reduction in operation speed or reduce the extent of the reduction in operation speed (deceleration rate).

[0069] That is, when the overturn prevention processing unit 12 is restricting the operation of the work machine 3 through overturn prevention control, the restriction on operation of the work machine 3 through overturn prevention control is restricted by the restriction processing unit 13 executing the restriction processing. In other words, the state is such that the operation of the work machine 3 is not restricted through overturn prevention control, or the restriction on operation is relaxed.

[0070] The sensitivity regulation processor 14 executes sensitivity regulation processing to regulate the response sensitivity of the motion restriction in the fall prevention control to the likelihood of tipping. In the sensitivity regulation processing, the sensitivity regulation processor 14 lowers the response sensitivity of the motion restriction to the likelihood of tipping when the likelihood of tipping decreases compared to when the likelihood of tipping increases. In the present disclosure, "response sensitivity" refers to the sensitivity of the response of the motion restriction by the fall prevention control that changes in response to a decrease or increase in the likelihood of tipping. For example, when the motion speed is reduced by the fall prevention control, if the response sensitivity is high, the amount of reduction in the motion speed (deceleration rate) changes sensitively in response to changes in the likelihood of tipping, whereas if the response sensitivity is low, the amount of reduction in the motion speed (deceleration rate) changes insensitively in response to changes in the likelihood of tipping.

[0071] In this embodiment, the response sensitivity is not constant, but differs between when the likelihood of tipping decreases and when the likelihood of tipping increases. Specifically, the sensitivity regulation processing unit 14 lowers the response sensitivity when the likelihood of tipping decreases compared to when the likelihood of tipping increases. In other words, the sensitivity regulation processing unit 14 increases the response sensitivity when the likelihood of tipping increases compared to when the likelihood of tipping decreases.

[0072] The presentation processing unit 15 executes a presentation process to present presentation information including the execution status of the fall prevention control. In this embodiment, the presentation processing unit 15 presents the presentation information by displaying the presentation information on the display unit 23 and / or the indicator lamp 36 of the display device 2.

[0073] The manner of presentation by the presentation processing unit 15 is not limited to displaying on the display unit 23 and / or the indicator light 36. For example, in addition to or instead of displaying, the presentation processing unit 15 may present the presentation information by sound output (from a sound output unit), printing, transmitting to another terminal, writing to a non-transitory recording medium, or a combination of these.

[0074] [3] Control method for work machine An example of a control method for the work machine 3 (hereinafter simply referred to as a "control method") that is mainly executed by the control system 1 will be described below with reference to FIGS.

[0075] The control method according to this embodiment is executed by a control system 1 whose main component is a computer system, 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 working together.

[0076] 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).

[0077] [3.1] Fall prevention measures Hereinafter, with reference to FIGS. 3 to 7, the process related to the tip-over prevention process in the control method according to this embodiment will be described.

[0078] In this embodiment, as described above, the overturn prevention processing unit 12 executes overturn prevention control to prevent the work machine 3 from overturning by restricting the operation of the work machine 3 based on the possibility of overturning evaluated by the evaluation processing unit 11. Basically, when there is a high possibility of overturning, that is, when the work machine 3 is in an unstable state where it is likely to overturn, the overturn prevention processing unit 12 prevents the work machine 3 from overturning by restricting the operation of the work machine 3 through overturn prevention control.

[0079] Here, the evaluation processing unit 11 evaluates the possibility of tipping over by calculating an evaluation value related to the possibility of tipping over, and the tipping prevention processing unit 12 restricts the operation of the work machine 3 based on this evaluation value. The "evaluation value" referred to in this disclosure is a numerical representation of the possibility of tipping over, and the magnitude of the evaluation value represents the possibility of tipping over. In this embodiment, as an example, the evaluation value is expressed as a percentage that varies between 0% and 100%, and the larger the value, the higher the possibility of tipping over (i.e., the work machine 3 is in an unstable state where it is likely to tip over).

[0080] More specifically, as shown in Fig. 3, the evaluation value is defined by the positional relationship between a focus point P1, which is the center of gravity position or ZMP (Zero Moment Point) of the machine body 30 of the work machine 3, and a tipping boundary A1, which is set with the work machine 3 as the reference. The center of gravity position or ZMP of the machine body 30 is identified using, for example, the current attitude of the work machine 3 detected by the attitude detection device 37, the work load, etc. The tipping boundary A1 is a boundary line that defines a critical point (limit point) such that, in a planar view, if the focus point P1 is inside the tipping boundary A1, the work machine 3 will not tip, and if the focus point P1 is outside the tipping boundary A1, the work machine 3 will tip.

[0081] The tipping boundary A1 is set, for example, based on a polygonal (quadrilateral) support base surface A2 formed by the contact of a pair of left and right crawlers 311 of the traveling unit 31 with the ground in a plan view. Specifically, the tipping boundary A1 is an oval (track-shaped) having a length in the front-to-rear direction D2, and the tipping boundary A1 is set based on the support base surface A2 so that the support base surface A2 circumscribes the tipping boundary A1. As shown in FIG. 3 , the support base surface A2 is determined by the positions of the wheels 313 (drive sprockets and tension rollers) of the crawlers 311 arranged at the four corners in a plan view. More specifically, the support base surface A2 is a quadrangle determined by the rotation axes of the wheels 313 in the front-to-rear direction D2 and the outer surfaces of the wheels 313 in the left-to-right direction D3.

[0082] In other words, the evaluation value of the possibility of tipping is determined based on the positional relationship of the attention point P1, which is the center of gravity position or ZMP of the aircraft 30, with respect to the tipping boundary A1, which is set based on the support base plane A2. Here, the evaluation value is determined by the distance from the tipping boundary A1 to the attention point P1 when the attention point P1 is inside the tipping boundary A1, and the evaluation value increases as the distance decreases. That is, as shown in FIG. 3, when the attention point P1 is located at the center of the tipping boundary A1, the distance from the tipping boundary A1 to the attention point P1 is at its maximum, so the evaluation value is 0%. On the other hand, as shown in FIG. 4, when the attention point P1 moves toward the tipping boundary A1, the distance from the tipping boundary A1 to the attention point P1 decreases, so the evaluation value increases. Then, when the attention point P1 reaches the tipping boundary A1, the distance from the tipping boundary A1 to the attention point P1 is at its minimum (0), so the evaluation value is 100%.

[0083] Furthermore, in this embodiment, during overturn prevention control, the overturn prevention processing unit 12 restricts the operation of the work machine 3 by reducing the operating speed of the work machine 3 in accordance with the possibility of overturning. In other words, when the possibility of overturning increases, the overturn prevention processing unit 12 controls the second control valve 472 and throttles down the second control valve 472, thereby slowing the operating speed of the work machine 3 below normal. Therefore, for example, by reducing the operating speed of the work machine 3 when there is a high possibility of overturning, it is possible to prevent overturning while continuing to operate the work machine 3.

[0084] In this embodiment in particular, the overturn prevention processing unit 12 reduces the operating speed of the work machine 3 by adjusting the speed scaling (deceleration rate) of the operating speed of the work machine 3 in accordance with the evaluation value related to the likelihood of overturning. "Speed ​​scaling" here is a value that expresses the ratio of the operating speed to the normal operating speed as a percentage; if the speed scaling is 0%, the operating speed of the work machine 3 will be 0 and the work machine 3 will stop, and if the speed scaling is 100%, no deceleration control will be performed (i.e., the normal operating speed will remain the same). In other words, the smaller the speed scaling, the greater the reduction in operating speed (deceleration rate), and the greater the speed scaling, the smaller the reduction in operating speed (deceleration rate).

[0085] 5 shows an example of the relationship between the evaluation value (horizontal axis) related to the likelihood of tipping and the speed scaling (vertical axis). In this embodiment, the evaluation value is a value determined by the distance from the tipping boundary A1 to the attention point P1, so the horizontal axis in FIG. 5 is synonymous with the distance from the tipping boundary A1 to the attention point P1. As shown in FIG. 5, if the evaluation value is equal to or less than a specified value X1, the speed scaling is fixed at 100%, and if the evaluation value exceeds the specified value X1 (for example, 30%), the speed scaling decreases.

[0086] As is clear from Fig. 5, in this embodiment, the overturn prevention processing unit 12 determines the speed scaling according to the evaluation value so that the speed scaling decreases as the evaluation value increases. Here, in the region where the evaluation value exceeds a specified value X1, the speed scaling gradually decreases, and when the evaluation value is 100%, it reaches a lower limit value V1 (15%, for example). The lower limit value V1 of the speed scaling can be set arbitrarily by the operator.

[0087] As explained above, in the control method according to this embodiment, the operation of the work machine 3 is restricted by reducing the operating speed of the work machine 3 based on the possibility of tipping over. As a result, when there is a high possibility of tipping over, that is, when the work machine 3 is in an unstable state where it is likely to tip over, the operating speed of the work machine 3 is reduced by the tipping prevention control, thereby preventing the work machine 3 from tipping over.

[0088] For example, when the operator operates the control device 35 to rotate the swivel unit 32, if the anti-tip control is not functioning, i.e., when the anti-tip control is disabled, the operating speed (swivel speed) of the swivel unit 32 is controlled to a "normal speed" according to the amount of operation of the control device 35. In contrast, even if the operator operates the control device 35 in the same way, the anti-tip control reduces the operating speed of the swivel unit 32 to a speed obtained by multiplying the normal speed by speed scaling. Therefore, if there is a high possibility of tipping, the operating speed of the swivel unit 32 and the like is reduced, and tipping of the machine body 30 is prevented.

[0089] Here, the possibility of tipping over is evaluated based on the positional relationship between a focus point P1, which is the center of gravity position or ZMP of the work machine 3, and a tipping boundary A1, which is set based on the work machine 3. Therefore, by identifying the focus point P1, the possibility of tipping over can be evaluated in real time, and appropriate tipping prevention control can be performed according to the current center of gravity position or ZMP of the work machine 3.

[0090] In this embodiment, presentation information according to the execution status of the anti-toppling control is presented as shown in Fig. 6 and Fig. 7. That is, the presentation processing unit 15 presents presentation information including the execution status of the anti-toppling control through the presentation process.

[0091] Specifically, the presentation processing unit 15 displays the execution status of the fall prevention control based on the lighting state of the indicator light 36, as shown in Fig. 6. As an example, if the evaluation value is 0%, only the green light-emitting unit 361 lights up as in the first example from the left in Fig. 6, if the evaluation value is 50%, only the yellow light-emitting unit 362 lights up as in the second example from the left in Fig. 6, and if the evaluation value is 100%, only the red light-emitting unit 363 lights up as in the third example from the left in Fig. 6.

[0092] However, this is not limiting, and for example, the presentation processing unit 15 may change the lighting state of the indicator light 36 according to the control amount of the fall prevention control, that is, the speed scaling. In this case, as an example, if the speed scaling is 100%, only the green light-emitting unit 361 lights up as in the first example from the left in Fig. 6, if the speed scaling is 50%, only the yellow light-emitting unit 362 lights up as in the second example from the left in Fig. 6, and if the speed scaling is the lower limit value V1, only the red light-emitting unit 363 lights up as in the third example from the left in Fig. 6.

[0093] In this way, the lighting state (e.g., color) of the indicator light 36 changes depending on the execution status of the anti-tip control (e.g., evaluation value or control amount of the anti-tip control), thereby making it possible to notify, for example, the operator and people around the aircraft 30 of the execution status of the anti-tip control.

[0094] Furthermore, the presentation processing unit 15 displays the execution status of the fall prevention control on the display screen of the display unit 23 of the display device 2, as shown in Fig. 7. Fig. 7 shows an example of a bar graph (indicator) on the display screen displayed on the display unit 23. Here, the bar graph not only changes its display amount (height) depending on the value, but also has a gradation in which the color differs depending on the area. As an example, if the evaluation value is 30%, a bar graph with a green area is displayed as in the first example from the left in Fig. 7, and if the evaluation value is 90%, a bar graph with a green area, a yellow area, and a red area is displayed as in the second example from the left in Fig. 7.

[0095] However, the present invention is not limited to this example. For example, the presentation processing unit 15 may change the display state of the display unit 23 (on its display screen) according to the control amount of the fall prevention control, that is, the speed scaling. In this case, as an example, if the speed scaling is 70%, a bar graph in the green region is displayed as in the first example from the left in Fig. 7, and if the speed scaling is near the lower limit value V1, bar graphs in the green region, yellow region, and red region are displayed as in the second example from the left in Fig. 7.

[0096] In this way, the display state (e.g., color) of the display unit 23 changes depending on the execution status of the anti-tip control (e.g., evaluation value or control amount of the anti-tip control), thereby making it possible to inform the operator, for example, of the execution status of the anti-tip control.

[0097] Furthermore, it is not essential to reduce the operating speed of the work machine 3 in accordance with the possibility of tipping over, and the tipping prevention processing unit 12 may set an upper limit for the operating speed of the work machine 3 in accordance with the possibility of tipping over during tipping prevention control. In other words, when the possibility of tipping over (evaluation value) increases, the tipping prevention processing unit 12 sets an upper limit for the operating speed of the work machine 3. Furthermore, by gradually lowering the upper limit in accordance with an increase in the evaluation value, the upper limit for the operating speed of the work machine 3 can be suppressed. In this case, as long as the operating speed is within a range below the upper limit, the work machine 3 can operate at an operating speed consistent with the operator's operation, thereby suppressing any deviation in the operating feel caused by tipping prevention control.

[0098] In the tip-over prevention control, it may be possible to arbitrarily switch between a mode in which the operating speed of the work machine 3 is reduced according to the possibility of tipping, and a mode in which an upper limit value for the operating speed of the work machine 3 is set according to the possibility of tipping.

[0099] Furthermore, the anti-tip control can be switched between enabled and disabled as desired using the display device 2 or another operating unit. Here, operation of the work machine 3 is restricted based on the evaluation value (likelihood of tipping) only when the anti-tip control is set to enabled. Furthermore, whether the anti-tip control is enabled or disabled may be displayed, for example, by the lighting state of a blue light-emitting element. As one example, the blue light-emitting element lights up when the anti-tip function is enabled, and flashes (or goes out) when the anti-tip function is disabled.

[0100] [3.2] Inhibitory control Hereinafter, with reference to FIGS. 5 to 8, the process related to the suppression control in the control method according to this embodiment will be described.

[0101] The control method according to this embodiment further comprises executing suppression control in addition to executing anti-tip control that restricts the operation of the work machine 3 based on the possibility of tipping over estimated from the state of the work machine 3. The suppression control is control that suppresses the restriction of the operation of the work machine 3 by the anti-tip control when the evaluation value related to the possibility of tipping over exceeds a threshold value.

[0102] That is, in this embodiment, the operation of the work machine 3 is not restricted by the anti-toppling control under all circumstances, but rather the restriction on the operation of the work machine 3 by the anti-toppling control is restricted (released or relaxed) by executing the restriction processing depending on the situation. As a result, for example, when the possibility of the work machine 3 tipping over increases significantly and the work machine 3 is about to tip over, the restriction on the operation of the work machine 3 by the anti-toppling control can be restricted (released or relaxed) by executing the restriction processing. As a result, for example, the traveling unit 31, swivel unit 32 and / or work implement 33 can be quickly operated in accordance with the operation of the operating device 35 by the operator, and operation can be performed to prevent the work machine 3 from tipping over. This has the advantage that the work machine 3 is less likely to tip over.

[0103] In this embodiment, the suppression processing unit 13 suppresses (suppression control) the operation restriction of the work machine 3 by anti-toppling control by canceling the operation restriction of the work machine 3 by anti-toppling control. In other words, when the suppression control is enabled in a state in which the speed scaling is reduced and the operation speed of the work machine 3 is reduced by anti-toppling control, the speed scaling becomes 100% and the reduction in the operation speed of the work machine 3 is released.

[0104] Here, in this embodiment, the threshold value is a value that will cause the work machine 3 to tip over if the evaluation value continues to exceed the threshold value. In other words, if no operation is performed on the work machine 3 when the evaluation value related to the possibility of tipping exceeds the threshold value, the work machine 3 will tip over. In this embodiment, as an example, as shown in FIG. 5, the threshold value X2 for the evaluation value is set to "100%". Therefore, for example, in the example of FIG. 5, in the area where the evaluation value exceeds the threshold value X2 (= 100%), the speed scaling is 100%.

[0105] In this embodiment, as described above, the evaluation value is defined by the positional relationship between attention point P1, which is the center of gravity position or ZMP of the work machine 3, and tipping boundary A1, which is set based on the work machine 3. When attention point P1 is outside tipping boundary A1, the evaluation value exceeds threshold value X2.

[0106] In short, when the attention point P1 goes outside the tipping boundary A1, the evaluation value exceeds the threshold X2, the suppression processing unit 13 executes the suppression control, and the suppression control becomes effective. When the suppression control becomes effective, the speed scaling becomes 100%, and the reduction in the operating speed of the work machine 3 is released. Therefore, it becomes possible to release the suppression control and release the tipping prevention control only when the risk of tipping has truly increased.

[0107] Furthermore, the control method according to this embodiment further includes disabling the suppression control when the evaluation value becomes equal to or less than the specified value X1 while the suppression control is active. In other words, once the suppression control is active because the evaluation value exceeds the threshold value X2, the suppression control does not remain active forever, but is automatically disabled when the evaluation value becomes equal to or less than the specified value X1. Therefore, for example, even if the suppression control is enabled and the anti-toppling control is released when the likelihood of tipping over increases significantly, the anti-toppling control can be restored when the likelihood of tipping over subsequently decreases.

[0108] Here, the specified value X1 can be set arbitrarily and may be, for example, the same value as the threshold value X2 or may be smaller than the threshold value X2. In this embodiment, as shown in Fig. 5, the specified value X1 is a value smaller than the threshold value X2. This makes it possible to avoid frequent switching between the enabled and disabled states of the suppression control even if the evaluation value fluctuates around the threshold value X2.

[0109] In other words, the control method according to this embodiment further includes disabling the suppression control when the attention point P1 moves further inward from the return boundary A3 (see FIG. 4) that is set inside the tipping boundary A1 while the suppression control is active. In other words, although the suppression control becomes active when the attention point P1 moves outside the tipping boundary A1, the suppression control is not disabled simply by moving the attention point P1 inside the tipping boundary A1; the suppression control is disabled only when the attention point P1 moves further inward to the return boundary A3.

[0110] More specifically, the evaluation value at which operation restriction by anti-toppling control begins to take effect is set to the specified value X1. In other words, if the evaluation value is smaller than the specified value X1, the speed scaling is 100% and the operation speed of the work machine 3 is not reduced by anti-toppling control, and if the evaluation value exceeds the specified value X1, the speed scaling is reduced and the operation speed of the work machine 3 is reduced by anti-toppling control. By adopting such a specified value X1, the suppression control is disabled only when the work machine 3 has reached a more stable state, making it easier to prevent the work machine 3 from tipping over.

[0111] Furthermore, the control method according to this embodiment further includes disabling the suppression control when a reset operation is performed while the suppression control is active. The "reset operation" here refers to, for example, a specific operation by the operator on the operation device 35 or the display device 2. This allows the operator to intentionally reset the suppression control when the possibility of tipping over increases significantly and the anti-tip control is released, for example, if the possibility of tipping over subsequently decreases.

[0112] 6 and 7, in this embodiment, the presentation information presented by the presentation processing unit 15 includes whether the inhibitor control is enabled or disabled. That is, the presentation information displayed on the indicator light 36 or the display unit 23 includes not only the execution status of the anti-tip control but also whether the inhibitor control is enabled or disabled. This makes it possible to notify the operator and / or people around the machine body 30 whether the inhibitor control is enabled or disabled.

[0113] Specifically, as shown in Fig. 6, the presentation processing unit 15 displays whether the suppression control is enabled or disabled depending on the lighting state of the indicator light 36. For example, when the suppression control is enabled, all of the light-emitting elements 361, 362, and 363 of the indicator light 36 are lit, as shown in the first example from the right in Fig. 6. In other words, when the suppression control is enabled and the operation restriction by the fall prevention control is released, all of the light-emitting elements 361, 362, and 363 of the indicator light 36 are lit.

[0114] Similarly, the presentation processing unit 15 displays whether the suppression control is enabled or disabled on the display screen of the display unit 23 of the display device 2, as shown in Fig. 7. For example, when the suppression control is enabled, the entire bar graph is displayed in red, as shown in the first example from the right in Fig. 7.

[0115] Thus, in this embodiment, the presentation of the presentation information includes a display by the display unit (indicator light 36 or display unit 23) that indicates the execution status of anti-toppling control when suppression control is disabled. When suppression control is enabled, the display mode of the display unit (indicator light 36 or display unit 23) is changed. In other words, the display unit (indicator light 36 or display unit 23) that indicates the execution status of anti-toppling control also serves to indicate that suppression control is enabled, so there is no need to provide a new display unit just for indicating whether suppression control is enabled or disabled.

[0116] Furthermore, at least one of the anti-tip control and the suppression control is enabled / disabled depending on the state of the cutoff lever 462. For example, when the cutoff lever 462 is in the "up position," the swivel unit 32, the travel unit 31, and the work implement 33 are all forcibly placed in a non-driveable state, and therefore the anti-tip control and / or the suppression control may be disabled when the cutoff lever 462 is in the "up position."

[0117] Next, the flow of main processes related to the suppression control of the control method according to this embodiment will be described with reference to the flowchart of FIG.

[0118] In step S1, the tip-over prevention processing unit 12 of the control system 1 executes tip-over prevention control to restrict the operation of the work machine 3 based on an evaluation value related to the possibility of tipping. In step S2, the suppression processing unit 13 of the control system 1 compares the evaluation value with a threshold value X2. If the evaluation value is equal to or less than the threshold value X2 (S2: No), the control system 1 returns the processing to step S1. On the other hand, if the evaluation value exceeds the threshold value X2 (S2: Yes), the suppression processing unit 13 executes suppression control to suppress the operation restriction by the tip-over prevention control (S3).

[0119] In step S4, the suppression processing unit 13 of the control system 1 compares the evaluation value with a specified value X1. If the evaluation value is equal to or less than the specified value X1 (S4: Yes), the control system 1 ends the suppression control and returns the process to step S1. On the other hand, if the evaluation value exceeds the specified value X1 (S4: No), the suppression processing unit 13 proceeds to step S5 and detects whether a return operation has been performed. If a return operation has not been performed (S5: No), the suppression processing unit 13 continues to perform suppression control that suppresses movement restriction by the tip-over prevention control (S3). If a return operation has been performed (S5: Yes), the control system 1 ends the suppression control and returns the process to step S1.

[0120] The control system 1 repeatedly executes the processes of steps S1 to S5 above. However, the flowchart shown in Fig. 8 is merely an example, and processes may be added or omitted as appropriate, and the order of processes may be changed as appropriate.

[0121] [3.3] Sensitivity regulation control Hereinafter, with reference to FIGS. 9 and 10, processing related to sensitivity regulation control in the control method according to this embodiment will be described.

[0122] The control method according to this embodiment further comprises executing sensitivity restriction control in addition to executing tip-over prevention control that restricts the operation of the work machine 3 based on the possibility of tip-over estimated from the state of the work machine 3. Sensitivity restriction control is control that makes the response sensitivity of the operation restriction in the tip-over prevention control to the possibility of tip-over lower when the possibility of tip-over decreases than when the possibility of tip-over increases.

[0123] That is, in this embodiment, the response sensitivity of the operation restriction to the possibility of tipping in the tip-over prevention control is not constant, and the response sensitivity is lower (less sensitive) when the possibility of tipping decreases compared to when the possibility of tipping increases. As a result, for example, even if the deployment possibility increases or decreases as the swivel unit 32 rotates, the swivel speed of the swivel unit 32 becomes less responsive when the possibility of tipping decreases, suppressing fluctuations in the swivel speed of the swivel unit 32 and making it easier to stabilize the operation of the swivel unit 32. Therefore, the control method according to this embodiment has the advantage of making it easier to operate the work machine 3 stably.

[0124] In this embodiment, the sensitivity restriction processing unit 14 sets the response sensitivity of the operation restriction in the anti-tip control to 0 when the likelihood of tipping decreases, so that the control amount of the anti-tip control does not change when the likelihood of tipping decreases. Specifically, if the speed scaling is reduced by the anti-tip control as the likelihood of tipping increases, the sensitivity restriction processing unit 14 does not increase the speed scaling even if the likelihood of tipping subsequently decreases. For example, if the speed scaling is reduced from 100% to 60% as the likelihood of tipping increases by the anti-tip control, the speed scaling will remain at 60% even if the likelihood of tipping subsequently decreases.

[0125] In other words, as shown in Fig. 9, even if the evaluation value related to the likelihood of tipping over fluctuates in accordance with the rotation of the rotation unit 32, the speed scaling will decrease unilaterally. Fig. 9 shows an example of the relationship between the rotation angle (horizontal axis) and the evaluation value and speed scaling when the rotation unit 32 is rotated in one direction at a constant speed. In other words, the horizontal axis in Fig. 9 is synonymous with the time axis.

[0126] As shown in Fig. 9, when the evaluation value increases with the rotation of the rotation unit 32, the speed scaling decreases due to the overturn prevention control so as to follow the increase in the evaluation value. On the other hand, after the rotation angle θ1 in Fig. 9, the speed scaling should normally increase due to the overturn prevention control so as to follow the decrease in the evaluation value (graph G2), but the speed scaling is maintained at a constant value due to the sensitivity restriction control (graph G1).

[0127] Furthermore, after the turning angle θ2 in Fig. 9, the speed scaling is further reduced by the anti-toppling control to follow the increase in the evaluation value. On the other hand, after the turning angle θ3 in Fig. 9, the speed scaling should normally increase by the anti-toppling control to follow the decrease in the evaluation value (graph G2), but instead the speed scaling is maintained at a constant value by the sensitivity restriction control (graph G1).

[0128] In this way, in sensitivity restriction control, the strength of the operation restriction is maintained when the possibility of tipping decreases. In other words, the control amount (speed scaling) of the tipping prevention control is maintained when the possibility of tipping decreases, thereby suppressing fluctuations in the control amount of the tipping prevention control. Therefore, for example, fluctuations in the operation speed of the work machine 3 are suppressed, making it easier to stabilize the operation of the work machine 3.

[0129] Incidentally, the sensitivity restriction control is only effective during specific operations of the work machine 3. In other words, as described above, when the possibility of tipping decreases, the response sensitivity becomes lower (less sensitive) compared to when the possibility of tipping increases, not for all operations of the work machine 3, but only during specific operations of the work machine 3. For this reason, the sensitivity restriction control is disabled for operations other than the specific operations of the work machine 3, and the response sensitivity is the same when the possibility of tipping decreases as when the possibility of tipping increases. Therefore, for operations other than the specific operations of the work machine 3, the control amount of the tipping prevention control can be varied to follow the decrease in the evaluation value, even when the possibility of tipping decreases, making it possible to avoid unnecessary restriction of operation by the tipping prevention control. As a result, an improvement in the work efficiency of the work machine 3 can be expected.

[0130] Here, the work machine 3 comprises a travel unit 31 and a swivel unit 32 that is disposed above the travel unit 31 and is rotatable relative to the travel unit 31 in a plan view. The specific operation is the swivel operation of the swivel unit 32. In other words, when the likelihood of tipping decreases, the response sensitivity becomes lower (less sensitive) only for the swivel operation of the swivel unit 32 compared to when the likelihood of tipping increases. Therefore, for example, sensitivity restriction control is disabled for the operation of the travel unit 31 or the work implement 33, and the response sensitivity becomes the same when the likelihood of tipping decreases as when the likelihood of tipping increases. Therefore, improved work efficiency by the work machine 3 can be expected.

[0131] Furthermore, the control method according to this embodiment further includes disabling the sensitivity restriction control if a cancellation condition is met while the sensitivity restriction control is active. In other words, even if the swivel section 32 is rotated, the sensitivity restriction control does not remain active thereafter, but is automatically disabled when the cancellation condition is met. Therefore, for example, it is possible to avoid unnecessary operation restrictions due to the anti-tip control being imposed by the sensitivity restriction control. As a result, improved work efficiency by the work machine 3 can be expected.

[0132] Here, the release condition includes a specific operation being performed. The "specific operation" here is, for example, a specific operation by the operator on the operation device 35 or the display device 2. As an example, the specific operation is an operation to return the operation device 35 (operation lever) for rotating the rotating part 32 to neutral. This allows the operator to intentionally disable the sensitivity restriction control, for example, even if the sensitivity restriction control is enabled and operation is restricted more than necessary by the anti-tip control.

[0133] Next, the flow of main processes related to the suppression control of the control method according to this embodiment will be described with reference to the flowchart of FIG.

[0134] In step S11, the tip-over prevention processing unit 12 of the control system 1 executes tip-over prevention control to restrict the operation of the work machine 3 based on the evaluation value related to the tip-over possibility. In step S12, the sensitivity restriction processing unit 14 of the control system 1 determines whether the swivel unit 32 is currently rotating. If the swivel unit 32 is not currently rotating (S12: No), the control system 1 returns the processing to step S11. On the other hand, if the swivel unit 32 is currently rotating (S12: Yes), the sensitivity restriction processing unit 14 executes sensitivity restriction control (S13) to lower the response sensitivity when the tip-over possibility is decreasing compared to when the tip-over possibility is increasing.

[0135] In step S14, the sensitivity regulation processing unit 14 of the control system 1 determines the position of the operating lever (swivel lever) for operating the swivel unit 32 in the operating device 35. If the swivel lever is in neutral (N) (S14: Yes), the control system 1 ends the sensitivity regulation control and returns the process to step S11. On the other hand, if the swivel lever is not in neutral (S14: No), the sensitivity regulation processing unit 14 continues to execute the sensitivity regulation control (S13).

[0136] The control system 1 repeatedly executes the processes of steps S11 to S14. However, the flowchart shown in Fig. 10 is merely an example, and processes may be added or omitted as appropriate, and the order of processes may be changed as appropriate.

[0137] [4] Variation Below, we will list some modified examples of embodiment 1. The modified examples explained below can be applied in appropriate combinations.

[0138] The control system 1 in the present disclosure includes a computer system. The computer system is primarily composed of one or more processors and one or more memories as hardware. The functions of the control system 1 in the present disclosure are realized by the processor executing a program 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 by being recorded on a non-transitory recording medium such as a memory card, optical disk, or hard disk drive that is readable 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.

[0139] 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 (for example, 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.

[0140] Furthermore, the operation lever of the operation device 35 may be an electric operation device configured to accept various operations by the 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 46 in response to the operation of the operation device 35 (operation lever).

[0141] The display device 2 is not limited to a dedicated device, but may be a general-purpose terminal such as a laptop computer, a tablet terminal, a smartphone, etc. Furthermore, the display unit 23 is not limited to a device that directly displays a display screen, such as a liquid crystal display or an organic EL display, but may be configured to display a display screen by projection, such as a projector.

[0142] 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.

[0143] [Appendix to the invention] The following is a summary 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.

[0144] <Appendix 1> Executing a tipping prevention control that restricts the operation of the work machine based on the possibility of tipping estimated from the state of the work machine; and executing sensitivity restriction control to make a response sensitivity of the operation restriction to the possibility of tipping lower when the possibility of tipping is decreasing than when the possibility of tipping is increasing in the tipping prevention control. A method for controlling a work machine.

[0145] <Appendix 2> In the sensitivity restriction control, when the possibility of tipping over decreases, the strength of the operation restriction is maintained. 2. A method for controlling a work machine as set forth in claim 1.

[0146] <Appendix 3> The method further includes disabling the sensitivity restriction control when a release condition is satisfied while the sensitivity restriction control is enabled. 3. A method for controlling a work machine according to claim 1 or 2.

[0147] <Appendix 4> The cancellation condition includes a specific operation being performed. 4. A method for controlling a work machine as set forth in appendix 3.

[0148] <Appendix 5> the anti-tip control reduces the operating speed of the work machine in accordance with the possibility of tipping over; A control method for a work machine according to any one of Supplementary Notes 1 to 4.

[0149] <Appendix 6> In the overturn prevention control, an upper limit value of the operating speed of the work machine is set in accordance with the possibility of overturning. A control method for a work machine according to any one of Supplementary Notes 1 to 4.

[0150] <Appendix 7> The possibility of tipping over is evaluated based on the positional relationship between a point of interest that is the center of gravity position or ZMP of the work machine and a tipping boundary that is set based on the work machine. A control method for a work machine according to any one of Supplementary Notes 1 to 6.

[0151] <Appendix 8> The sensitivity regulation control is effective only during a specific operation of the work machine. A control method for a work machine according to any one of Supplementary Notes 1 to 7.

[0152] <Appendix 9> The work machine includes a traveling unit and a turning unit that is disposed above the traveling unit and is capable of turning relative to the traveling unit in a plan view, The specific operation is a rotation operation of the rotation unit. 9. A method for controlling a work machine as set forth in appendix 8.

[0153] <Appendix 10> A control method for a work machine according to any one of appendices 1 to 9, A control program for a work machine to be executed by one or more processors. [Explanation of symbols]

[0154] 1. Work machine control system 3. Work machinery 12 Fall prevention processing section 14 Sensitivity regulation processing section 30 aircraft 31 Running part 32 Swivel section A1 Fall boundary P1 Highlights

Claims

1. Executing a tipping prevention control that restricts the operation of the work machine based on the possibility of tipping estimated from the state of the work machine; and executing sensitivity restriction control to make a response sensitivity of the operation restriction to the possibility of tipping lower when the possibility of tipping is decreasing than when the possibility of tipping is increasing in the tipping prevention control. A method for controlling a work machine.

2. In the sensitivity restriction control, when the possibility of tipping over decreases, the strength of the operation restriction is maintained. A method for controlling a work machine according to claim 1.

3. The method further includes disabling the sensitivity restriction control when a release condition is satisfied while the sensitivity restriction control is enabled. A control method for a work machine according to claim 1 or 2.

4. The cancellation condition includes a specific operation being performed. The method for controlling a work machine according to claim 3.

5. the anti-tip control reduces the operating speed of the work machine in accordance with the possibility of tipping over; A control method for a work machine according to claim 1 or 2.

6. In the overturn prevention control, an upper limit value of the operating speed of the work machine is set in accordance with the possibility of overturning. A control method for a work machine according to claim 1 or 2.

7. The possibility of tipping over is evaluated based on the positional relationship between a focus point formed by the center of gravity position or ZMP of the work machine and a tipping boundary set based on the work machine. A control method for a work machine according to claim 1 or 2.

8. The sensitivity regulation control is effective only during a specific operation of the work machine. A control method for a work machine according to claim 1 or 2.

9. The work machine includes a traveling unit and a turning unit that is disposed above the traveling unit and is capable of turning relative to the traveling unit in a plan view, The specific operation is a rotation operation of the rotation unit. A method for controlling a work machine according to claim 8.

10. A control method for a work machine according to claim 1 or 2, A control program for a work machine for execution by one or more processors.

11. a tipping prevention processing unit that executes tipping prevention control to restrict the operation of the work machine based on the possibility of tipping estimated from the state of the work machine; a sensitivity restriction processing unit that reduces the response sensitivity of the operation restriction to the possibility of tipping in the tipping prevention control when the possibility of tipping decreases compared to when the possibility of tipping increases, Control systems for work machines.

12. A control system for a work machine according to claim 11; and Work machinery.

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