Work machine, and control method of work machine

Abstract

To reduce a risk of the occurrence of a behavior unintended by an operator in a work machine equipped with an external control interface that receives control commands from the outside.SOLUTION: When a state of a locking device is switched to an unlocked state that allows operation of an actuator, in a case when a switching device receives a switching operation for switching whether to control the actuator according to either an operation command from an operation device of a work machine or a control command received by an external control interface from the outside of the work machine, the work machine executes automatic stop control to stop the operation of the actuator until a predetermined release condition is established.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a work machine and a method for controlling a work machine. [Background technology]

[0002] In recent years, labor shortages in the civil engineering and construction industries have led to increased attention being paid to the remote or automatic control of work machines (hereinafter referred to as "remote automatic control"). One method for achieving remote automatic control of work machines is to open up the work machine's actuator control functions to the outside world via an API (Application Programming Interface), rather than directly modifying the work machine. With this method, instead of an on-board human interface, an interface unit (external control interface unit) that controls the work machine in response to external control commands is installed in the work machine beforehand. An external control device that generates remote automatic control commands is configured to suit the work site or work content, and is connected to the work machine. This results in a remote automatic control system. The work machine is remotely controlled by a computer external to the work machine or by a remote operator.

[0003] An example of a work machine is a construction vehicle. Even if the work machine is under remote automatic control, an operator may need to ride on the work machine to check its operation or monitor its operation.

[0004] Background art relating to automatic control systems when an operator is on board includes, for example, International Publication No. 2019 / 181872 (Patent Document 1) and Patent Publication No. 2021-139143 (Patent Document 2).

[0005] Patent document 1 states that "the control device is configured to autonomously execute the combined operation when a first switch provided in a cab installed on the upper rotating body is operated."

[0006] Patent Document 2 states that "the device comprises a work machine, an automatic control device that automatically controls the work machine in accordance with design information, an operating lever that manually controls the work machine, and an automatic switch that is attached to the operating lever and that selectively switches the automatic control between enabled and disabled, and the manual control of the work machine takes priority over the automatic control." [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2019 / 181872 Brochure [Patent Document 2] Japanese Patent Publication No. 2021-139143 Summary of the Invention [Problem to be solved by the invention]

[0008] The work machine has a switching device that accepts a switching operation to switch whether actuator control is to be performed in response to an operation command from an operating device of the work machine or a control command from outside the work machine (i.e., disabling or enabling the external control interface unit).In order to control the actuators of the work machine in response to an external control command, the switching device needs to accept a switching operation to enable the external control interface unit.

[0009] In addition, when an on-board operator uses a work machine under remote automatic control, it is desirable for the on-board operator to be able to temporarily suspend the remote automatic control in order to give priority to operation at the on-board operator's discretion.

[0010] A typical work machine is equipped with a locking device that switches between a locked state, which locks the operation of the actuator, and an unlocked state, which allows the actuator to operate. When the work machine is in the locked state, unintended behavior of the actuator can be prevented even if the on-board operator unintentionally touches the work lever. This locking device can be used as a temporary stopping means for remote automatic control. By releasing the locked state of the work machine with the locking device, it becomes possible to control the work machine remotely.

[0011] However, if the switching device accepts a switching operation when the work machine is in an unlocked state, the actuator may operate unintentionally for the on-board operator. For example, if the external control interface unit is enabled when the work machine is in an unlocked state, the actuator may operate before the on-board operator has completed checking the safety of the surrounding area. On the other hand, if the external control interface unit is disabled when the work machine is in an unlocked state, the actuator may operate unintentionally for the on-board operator if the on-board operator unintentionally touches the operating lever.

[0012] Therefore, in consideration of the above-mentioned problems, the present invention aims to reduce the risk of unintended behavior by an operator on a work machine equipped with an external control interface unit that receives control commands from the outside. [Means for solving the problem]

[0013] When the state of the locking device has been switched to an unlocked state that allows the actuator to operate, if the switching device accepts a switching operation, the work machine executes automatic stop control that stops the operation of the actuator until a specified release condition is met. [Effects of the Invention]

[0014] According to the present invention, it is possible to reduce the risk of an operator on a work machine that is equipped with an external control interface unit that receives control commands from the outside exhibiting unintended behavior. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a system block diagram of a first embodiment. [Figure 2] 1 is a diagram showing a work machine (shovel) according to a first embodiment. [Figure 3] 1 is a flowchart of the first embodiment. [Figure 4] 10 is a part of a flowchart of a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the following description, "memory" refers to one or more memory devices, typically a primary storage device. At least one memory device in the memory may be a volatile memory device or a non-volatile memory device.

[0017] In the following description, a "persistent storage device" refers to one or more persistent storage devices. A persistent storage device is typically a non-volatile storage device (e.g., an auxiliary storage device), and specifically, for example, an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0018] Also, in the following description, "storage" may be memory, or memory and persistent storage.

[0019] In the following description, a "processor" refers to one or more processor devices. The at least one processor device is typically a microprocessor device such as a CPU (Central Processing Unit), but may also be other types of processor devices such as a GPU (Graphics Processing Unit). The at least one processor device may be a single-core or multi-core. The at least one processor device may also be a processor core. The at least one processor device may also be a processor device in a broader sense, such as a hardware circuit (e.g., an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit)) that performs part or all of the processing.

[0020] In the following description, functions may be described using the expression "yyy unit." However, the functions may be realized by one or more computer programs executed by a processor, by one or more hardware circuits (e.g., FPGAs or ASICs), or by a combination thereof. When a function is realized by a program executed by a processor, the specified processing is performed using a storage device and / or an interface device, etc., as appropriate, and therefore the function may be considered to be at least a part of the processor. Processing described using a function as the subject may be processing performed by a processor or a device having the processor. A program may be installed from a program source. The program source may be, for example, a computer from which the program is distributed or a computer-readable recording medium (e.g., a non-transitory recording medium). The description of each function is an example, and multiple functions may be combined into one function, or one function may be divided into multiple functions.

[0021] Some examples will be described below. [Example]

[0022] FIG. 1 is a system block diagram of the first embodiment.

[0023] The work machine 100 comprises a work machine body, an actuator 120, an operating lever 101, a pilot shutoff lever 102, an external control permission / denial device 103, and a control device 110. The control device 110 comprises a communication interface device, a storage device, and a processor connected to these, and the processor may realize functions such as a control command arbitration unit 111, an external control interface unit 112, an actuator control unit 113, a lock command unit 114, and an automatic stop determination unit 115.

[0024] The work machine body is the main part of the work machine 100. For example, if the work machine 100 is an excavator as shown in FIG. 2, the work machine body is the vehicle body 180. The excavator is made up of an upper rotating body 202 including a cab 201 and a counterweight 207, a crawler-type lower traveling body 206, and a work implement including a boom 203, an arm 204, and a bucket 205. Examples of the actuator 120 are a boom cylinder 213, an arm cylinder 214, a bucket cylinder 215, a swing motor 212 (a motor that swings the upper rotating body 202 relative to the lower traveling body 206), and a travel motor 216 (a motor that moves the lower traveling body 206).

[0025] The control lever 101 is an example of an operation device (a device that outputs an operation command to operate the actuator in accordance with the amount of operation) serving as a human interface that accepts an operation that causes the actuator 120 to behave. The pilot shutoff lever 102 is an example of a locking device (a device that switches between a locked state that locks the actuator's operation and an unlocked state that allows the actuator's operation) serving as a human interface that accepts an input to enable lock (a state in which the actuator's operation is locked) or an input to unlock the lock. The external control enabling / disabling device 103 is an example of a switching device serving as a human interface that accepts a switching operation between enabling and disabling the external control interface unit 112 (a switching operation that switches whether control of the actuator 120 is performed in accordance with an operation command from the control lever 101 of the work machine 100 or a control command from outside the work machine). The operation device and the locking device may be other types of human interfaces instead of levers. The switching device may also be a lever, or a type of human interface other than a lever.

[0026] When the operation lever 101 is operated by the onboard operator, an operation command according to the content of the operation accepted by the operation lever 101 is transmitted to the control command arbitration unit 111. For convenience, the operation command from the operation lever 101 will be referred to as a "manual control command" hereinafter.

[0027] The external control interface unit 112 receives control commands from a computer system external to the work machine 100, or from an information processing terminal external to the work machine 100 that is operated by a remote operator. The work machine 100 may be automatically remotely controlled in accordance with control commands from an external computer system, or may be manually remotely controlled in accordance with control commands from an information processing terminal operated by an external remote operator. The control commands received by the external control interface unit 112 are transmitted to the control command arbitration unit 111. Hereinafter, the control commands received by the external control interface unit 112 will be referred to as "external control commands."

[0028] The external control permission / non-permission device 103 receives a switching operation from the on-board operator to switch between enabling and disabling the external control interface unit 112. In response to the switching operation, the external control permission / non-permission device 103 enables or disables the external control interface unit 112. When the external control interface unit 112 is enabled, an actuator control command (a control command for controlling the actuator) is generated based on an external control command, not a manual control command. On the other hand, when the external control interface unit 112 is disabled, the actuator control command is generated based on a manual control command, not an external control command.

[0029] The control command arbitration unit 111 arbitrates between manual control commands and external control commands depending on whether the external control interface unit 112 is enabled or disabled. Specifically, when the external control interface unit 112 is enabled, the control command arbitration unit 111 does not accept a manual control command (or invalidates the manual control command), creates an actuator control command based on the external control command from the external control interface unit 112, and transmits the actuator control command to the actuator control unit 113. On the other hand, when the external control interface unit 112 is disabled, the control command arbitration unit 111 does not accept an external control command (or invalidates the external control command), creates an actuator control command based on the manual control command from the operating lever 101, and transmits the actuator control command to the actuator control unit 113.

[0030] The pilot shutoff lever 102 can be switched between a locked position (a position for inputting a locked state) and an unlocked position (a position for inputting an unlocked state) by operation of the onboard operator. The position of the pilot shutoff lever 102 is detected by a lock command unit 114.

[0031] Lock command unit 114 outputs a lock command to actuator control unit 113 when it detects that pilot shutoff lever 102 has been placed in the locked position.

[0032] Based on the actuator control command, the actuator control unit 113 controls the actuator 120. When the actuator control unit 113 receives a lock command from the lock command unit 114, the actuator control unit 113 prioritizes the lock command over the actuator control command from the control command arbitration unit 111 (i.e., stops the actuator 120).

[0033] The automatic stop determination unit 115 determines whether an automatic stop is necessary or not, depending on the outputs of the external control permission / prohibition device 103 and the pilot shutoff lever 102. "Automatic stop" means automatically stopping the operation of the actuator 120. If the automatic stop determination unit 115 determines that an automatic stop is necessary, it sends a lock command to the actuator control unit 113 via the lock command unit 114.

[0034] The processing of the automatic stop determination unit 115 and the lock command unit 114 in this embodiment is shown in the flowchart of FIG. 3. This flowchart begins execution simultaneously with the start of the excavator and is repeatedly executed at a predetermined cycle (for example, the same cycle as the control cycle of the actuator 120). Hereinafter, this embodiment will be described with reference to this flowchart. In this embodiment, a flag (or other type of information) may be prepared in the storage device of the control device 110 for each of the lock, automatic stop, and external control interface unit 112. Specifically, for example, locking can be enabled (set) by setting the lock flag f1 (for example, f1 = 1), locking can be maintained by not changing f1 = 1, and locking can be disabled (released) by releasing the flag f1 (for example, f1 = 0). Automatic stop can be enabled by setting the automatic stop flag f2 (for example, f2 = 1), and automatic stop can be disabled by releasing the flag f2 (for example, f2 = 0). The external control interface unit 112 can be enabled by setting the flag f3 of the external control interface unit 112 (for example, f3=1), and can be disabled by clearing the flag f3 (for example, f3=0).

[0035] In step 301, automatic stop determination unit 115 determines whether pilot shutoff lever 102 is in the unlocked position. If it is in the unlocked position (step 301: Yes), the process proceeds to step 302. If pilot shutoff lever 102 is not in the unlocked position but in the locked position (step 301: No), automatic stop determination unit 115 disables automatic stop (step 307), and lock command unit 114 sets or maintains the lock (step 306).

[0036] In step 302, automatic stop determination unit 115 determines whether automatic stop is already enabled. Even if pilot shutoff lever 102 is in the unlocked position, if automatic stop is enabled (step 302: Yes), lock command unit 114 maintains the lock (step 306). If pilot shutoff lever 102 is in the unlocked position and automatic stop is disabled (step 302: No), the process proceeds to step 303.

[0037] In step 303, automatic stop determination unit 115 determines whether the state of external control interface unit 112 has been switched from enabled to disabled or from disabled to enabled through external control permission / non-permission device 103. If a switch is detected (step 303: Yes), automatic stop determination unit 115 enables automatic stop (step 304), and lock command unit 114 maintains the lock even though pilot shutoff lever 102 is in the unlocked position (step 306). If a switch is not detected (step 303: No), lock command unit 114 releases the lock (step 305).

[0038] As described above, when the pilot shutoff lever 102 is in the unlocked position (step 301: Yes) and the external control permission / non-permission device 103 accepts a switching operation (step 303: Yes), the control device 110 executes an automatic stop (step 304) that stops the operation of the actuator 120 until a predetermined release condition is met (for example, until the pilot shutoff lever 102 is switched to the locked position). This reduces the risk of the working machine 100 equipped with the external control interface unit 112 behaving in a way that is unintended by the operator.

[0039] Specifically, if automatic stop is disabled (step 302: No) and an operation to enable or disable the external control interface unit 112 is accepted (step 303: Yes), the control device 110 enables automatic stop (step 304) and sets a lock (step 306).

[0040] Specifically, when the automatic stop is enabled and the lock is set, if a lock input is received (step 301: No), the control device 110 disables the automatic stop (step 307) and maintains the lock (step 306). If a lock release input is received thereafter (for example, in the next cycle) (step 301: Yes), the control device 110 releases the lock (step 305). In other words, in order to move the actuator 120 when enabling or disabling the external control interface unit 112, it is necessary to first move the pilot shutoff lever 102 to the lock position and then move it to the unlock position. This makes it possible to prevent the work machine 100 (for example, the vehicle body) from starting to move simultaneously with enabling or disabling the external control interface unit 112.

[0041] In this embodiment, enabling or disabling the external control interface unit 112 may be synonymous with enabling or disabling remote control or automatic control. [Example]

[0042] A description will be given of Example 2. Differences from Example 1 will be mainly described, and explanations of commonalities with Example 1 will be omitted or simplified.

[0043] FIG. 4 is a part of a flowchart of the second embodiment.

[0044] If pilot shutoff lever 102 is in the unlocked position, automatic stop is disabled (step 302: No), and an operation to switch between enabling and disabling external control interface unit 112 has not been received (step 303: No), automatic stop determination unit 115 determines whether external control interface unit 112 is enabled in step 401. If external control interface unit 112 is disabled (step 401: No), lock command unit 114 releases the lock (step 305).

[0045] On the other hand, if the external control interface unit is enabled (step 401: Yes), in step 402, automatic stop determination unit 115 determines whether the unlocking elapsed time, which is the time elapsed since pilot shutoff lever 102 transitioned from the locked position to the unlocked position, is equal to or greater than a predetermined time. If the unlocking elapsed time is less than the predetermined time (step 402: No), lock command unit 114 sends a lock command (step 306). If the unlocking elapsed time is equal to or greater than the predetermined time (step 402: Yes), lock command unit 114 releases the lock (step 305).

[0046] As described above, if external control interface unit 112 is enabled in advance, when control device 110 receives an input to release the lock, it does not immediately disable the lock, but keeps the lock enabled until a predetermined time has elapsed since the input to release the lock was received. This prevents remote control (manual or automatic remote control) from starting immediately when the position of pilot shutoff lever 102 is changed to the unlock position.

[0047] Although several embodiments have been described above, these are merely examples for explaining the present invention, and it is not intended that the scope of the present invention be limited to only these embodiments. The present invention can be implemented in various other forms. For example, instead of or in addition to a shovel, the present invention can be applied to various work machines (for example, construction work machines such as construction vehicles, or other work machines). Furthermore, the processing of the flowcharts in FIGS. 3 and 4 may be performed by a device other than the control device 110 (for example, a remote device such as a server capable of communicating with the work machine 100). [Explanation of symbols]

[0048] 100 Work Machinery 101 Operating lever (an example of an operating device) 102 Pilot shut-off lever (an example of a locking device) 103 External control permission device (an example of a switching device) 110 Control device 120 Actuator

Claims

1. An actuator; an operating device that outputs an operation command for the actuator in accordance with an operation amount; a locking device that switches between a locked state that locks the operation of the actuator and an unlocked state that allows the operation of the actuator; a control device having an external control interface unit that receives a control command to operate the actuator from the outside, and that controls the actuator in accordance with the operation command output from the operating device or the control command received by the external control interface control unit; a switching device that accepts a switching operation to switch whether control of the actuator by the control device is to be executed in accordance with the operation command from the operating device or the control command from the outside that is accepted by the external control interface, When the switching device receives the switching operation while the locking device has switched to the unlocked state, the control device executes automatic stop control to stop operation of the actuator until a predetermined release condition is met.

2. The predetermined release condition includes that the locking device is switched to the locked state.

2. The work machine according to claim 1.

3. When the locking device receives a command to switch to the locked state in the unlocked state, the control device disables the automatic stop control.

2. The work machine according to claim 1.

4. When the locking device accepts the switch to the unlocked state, the automatic stop control is disabled, and the external control interface unit is enabled, the control device maintains the locked state until a predetermined unlocking time has elapsed, which is the time elapsed since the switch to the unlocked state was accepted.

2. The work machine according to claim 1.

5. A control method for a work machine including an external control interface unit that receives control commands from outside the work machine, and controls an actuator in accordance with an operation command output from an operating device of the work machine or a control command received by the external control interface unit from the outside, comprising: When the state of the work machine is an unlocked state which allows operation of the actuator, if a switching operation is received to switch whether to control the actuator in accordance with an operation command from an operating device of the work machine or a control command from outside the work machine, an automatic stop control is executed to stop operation of the actuator until a predetermined release condition is met. A method for controlling a work machine.

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