Work machine control system

Abstract

A work machine control system according to the present invention comprises: a plurality of actuators; and a controller that receives a plurality of operation commands for operating the plurality of actuators and that controls at least one actuator among the plurality of actuators. The controller acquires a plurality of operation commands for causing one actuator to operate, and calculates action commands for the one actuator on the basis of the relationship between the plurality of operation commands and action commands for the one actuator which correspond to the plurality of operation commands.

Description

Control System of Working Machine

[0001] The present disclosure relates to a control system of a working machine.

[0002] In the technical field related to working machines, a hydraulic excavating vehicle as disclosed in Patent Document 1 is known. In Patent Document 1, when an operator selects a working mode at hand, the speed control method during combined operation is changed. Specifically, the magnitude or the ratio of the speed of the actuator operation during combined operation is changed.

[0003] Japanese Patent Application Laid-Open No. 2002-038533

[0004] When simultaneously operating a plurality of actuators of a working machine, an operator performs a combined operation of an operating device so that the plurality of actuators operate simultaneously. When moving a working device of a working machine along a target trajectory by combined operation, the proficiency of the operator is required.

[0005] An object of the present disclosure is to operate a working machine in accordance with the intention of an operator performing a combined operation.

[0006] According to the present disclosure, there are provided a plurality of actuators and a controller that receives a plurality of operation commands for operating the plurality of actuators and controls at least one of the plurality of actuators. A control system of a working machine is provided. The controller obtains a plurality of operation commands for operating one actuator, and calculates an operation command for one actuator based on the relationship between the plurality of operation commands and the operation command of one actuator corresponding to the plurality of operation commands.

[0007] According to the present disclosure, a working machine can be operated in accordance with the intention of an operator performing a combined operation.

[0008] Figure 1 is a side view showing a work machine according to an embodiment. Figure 2 is a diagram showing the cab of the work machine according to an embodiment. Figure 3 is a schematic diagram showing the control system of the work machine according to an embodiment. Figure 4 is a hardware configuration diagram showing the controller according to an embodiment. Figure 5 is a functional block diagram showing the controller according to an embodiment. Figure 6 is a diagram illustrating correlation data according to an embodiment. Figure 7 is a diagram illustrating the first correlation data according to an embodiment. Figure 8 is a diagram illustrating the fourth correlation data according to an embodiment. Figure 9 is a diagram illustrating a method for calculating the target operating speed of actuators when the operating device is operated in combination so that two actuators operate simultaneously according to an embodiment. Figure 10 is a diagram illustrating priority according to an embodiment. Figure 11 is a diagram illustrating a first example of a method for calculating the target operating speed of actuators when the operating device is operated in combination so that at least two actuators operate simultaneously according to an embodiment. Figure 12 is a diagram illustrating a second example of a method for calculating the target operating speed of actuators when the operating device is operated in combination so that at least two actuators operate simultaneously according to an embodiment. Figure 13 is a flowchart illustrating a control method for a work machine according to an embodiment. Figure 14 is a diagram illustrating the effects of the control method for a work machine according to an embodiment. Figure 15 is a diagram illustrating a method for changing correlation data according to an embodiment. Figure 16 is a schematic diagram showing a work machine cylinder according to an embodiment. Figure 17 is a flowchart showing a control method for a work machine according to an embodiment. Figure 18 is a diagram illustrating a method for calculating the flow rate of hydraulic fluid supplied to the boom cylinder when it is determined that a high-load combined operation state is in place according to an embodiment. Figure 19 is a diagram illustrating a method for calculating the flow rate of hydraulic fluid supplied to the arm cylinder when it is determined that a high-load combined operation state is in place according to an embodiment. Figure 20 is a flowchart showing a control method for a work machine according to an embodiment. Figure 21 is a schematic diagram showing a part of the control system for a work machine according to an embodiment. Figure 22 is a schematic diagram showing a part of the control system for a work machine according to an embodiment. Figure 23 is a schematic diagram showing a part of the control system for a work machine according to an embodiment.

[0009] [Work Machinery] Figure 1 is a side view showing work machine 1 according to an embodiment. Work machine 1 operates at the work site. Examples of work machine 1 include a hydraulic excavator, a wheel loader, and a bulldozer. In this embodiment, work machine 1 is a hydraulic excavator.

[0010] The work machine 1 comprises a traveling body 2, a rotating body 3, a work implement 4, a rotating motor 5, a work implement cylinder 6, a controller 7, an operating device 8, and a monitor 9.

[0011] In this embodiment, the slewing motor 5 is a hydraulic motor driven by hydraulic fluid. The slewing motor 5 may also be an electric motor. In this embodiment, the work machine cylinder 6 is a hydraulic cylinder driven by hydraulic fluid. The work machine cylinder 6 may also be an electric cylinder.

[0012] The running body 2 supports the rotating body 3. The running body 2 has a pair of tracks 2A. The working machine 1 moves as the tracks 2A rotate.

[0013] The slewing body 3 is positioned above the traveling body 2. The slewing body 3 is rotatably supported by the traveling body 2. The slewing body 3 has a cab 10. The operator of the work machine 1 is seated in the cab 10. The control device 8 and monitor 9 are located in the cab 10.

[0014] The work implement 4 is rotatably mounted on the slewing body 3. The work implement 4 includes a boom 4A, an arm 4B, and a bucket 4C. The boom 4A is rotatably connected to the front of the slewing body 3. The arm 4B is rotatably connected to the tip of the boom 4A. The bucket 4C is rotatably connected to the tip of the arm 4B.

[0015] The slewing motor 5 rotates the slewing body 3, which is supported by the traveling body 2. The slewing motor 5 is a hydraulic motor driven by hydraulic fluid. The slewing motor 5 is an example of an actuator driven by hydraulic fluid.

[0016] The work implement cylinder 6 operates the work implement 4 attached to the slewing body 3. The work implement cylinder 6 is a hydraulic cylinder driven by hydraulic fluid. The work implement cylinder 6 is an example of an actuator driven by hydraulic fluid. The work implement cylinder 6 has a cylinder tube, a piston that is movable inside the cylinder tube, and a rod fixed to the piston. The piston divides the inside of the cylinder tube into a head chamber and a bottom chamber. The work implement cylinder 6 retracts as hydraulic fluid flows into the head chamber and out of the bottom chamber. The work implement cylinder 6 extends as hydraulic fluid flows into the bottom chamber and out of the head chamber. The work implement cylinder 6 includes a boom cylinder 6A, an arm cylinder 6B, and a bucket cylinder 6C.

[0017] The boom cylinder 6A operates the boom 4A. The base end of the cylinder tube of the boom cylinder 6A is connected to the slewing body 3, and the tip of the rod of the boom cylinder 6A is connected to the boom 4A. The operation of the boom 4A includes raising and lowering movements. When hydraulic fluid flows into the bottom chamber of the boom cylinder 6A and the boom cylinder 6A extends, the boom 4A is raised. When hydraulic fluid flows into the head chamber of the boom cylinder 6A and the boom cylinder 6A retracts, the boom 4A is lowered.

[0018] The arm cylinder 6B operates the arm 4B. The base end of the cylinder tube of the arm cylinder 6B is connected to the boom 4A, and the tip of the rod of the arm cylinder 6B is connected to the arm 4B. The operation of the arm 4B includes digging and dumping operations. When hydraulic fluid flows into the bottom chamber of the arm cylinder 6B and the arm cylinder 6B extends, the arm 4B performs the digging operation. When hydraulic fluid flows into the head chamber of the arm cylinder 6B and the arm cylinder 6B retracts, the arm 4B performs the dumping operation.

[0019] The bucket cylinder 6C operates the bucket 4C. The base end of the cylinder tube of the bucket cylinder 6C is connected to the arm 4B, and the tip of the rod of the bucket cylinder 6C is connected to the bucket 4C via a link mechanism. The operation of the bucket 4C includes digging and dumping operations. When hydraulic fluid flows into the bottom chamber of the bucket cylinder 6C and the bucket cylinder 6C extends, the bucket 4C performs the digging operation. When hydraulic fluid flows into the head chamber of the bucket cylinder 6C and the bucket cylinder 6C retracts, the bucket 4C performs the dumping operation.

[0020] [Cab] Figure 2 is a diagram showing the cab 10 of the work machine 1 according to the embodiment. As shown in Figure 2, the operating device 8 and the monitor 9 are located in the cab 10. The operating device 8 is operated to operate at least one of the traveling body 2, the rotating body 3, and the work machine 4. The operating device 8 is operated by an operator who is seated in the cab 10. The operator can operate the operating device 8 while seated in the driver's seat 11 located in the cab 10.

[0021] The operating device 8 includes a left work lever 8A and a right work lever 8B, which are operated to operate the slewing body 3 and the work implement 4; a left travel lever 8C and a right travel lever 8D, which are operated to operate the traveling body 2; and a left foot pedal 8E and a right foot pedal 8F.

[0022] When the left work lever 8A is operated in the forward / backward direction, the arm 4B performs a dumping or digging operation. When the left work lever 8A is operated in the left / right direction, the slewing body 3 performs a left or right slewing operation. When the right work lever 8B is operated in the left / right direction, the bucket 4C performs an digging or dumping operation. When the right work lever 8B is operated in the forward / backward direction, the boom 4A performs a lowering or raising operation. Alternatively, when the left work lever 8A is operated in the forward / backward direction, the slewing body 3 may perform a right or left slewing operation. When the left work lever 8A is operated in the left / right direction, the arm 4B may perform a dumping or digging operation.

[0023] When the left travel lever 8C is operated in the forward or backward direction, the left track 2A of the vehicle 2 moves forward or backward. When the right travel lever 8D is operated in the forward or backward direction, the right track 2A of the vehicle 2 moves forward or backward.

[0024] The left foot pedal 8E is linked to the left travel lever 8C. The right foot pedal 8F is linked to the right travel lever 8D. By operating the left foot pedal 8E and the right foot pedal 8F, the vehicle 2 may move forward or backward.

[0025] The monitor 9 is positioned to the right and in front of the driver's seat 11. The monitor 9 includes a display device 9A and an input device 9B. The display device 9A displays display data. The display device 9A provides display data to the operator seated in the cab 10. An example of the display device 9A is a flat panel display such as a liquid crystal display or an organic EL display. The input device 9B is operated by the operator seated in the cab 10. The input device 9B generates input data when operated by the operator. An example of the input device 9B is a touch panel, a button switch, and a computer keyboard.

[0026] [Operated Amount] The operating device 8 is operated to operate the actuators of the work machine 1. The actuators include a slewing motor 5 and a work machine cylinder 6. As described above, the operating device 8 includes a left work lever 8A and a right work lever 8B which are operated to operate the slewing body 3 and the work machine 4. When the operating device 8 is operated, an operation command (electrical signal) is generated. The operation command of the operating device 8 is transmitted to the controller 7. The operation command of the operating device 8 includes the operated amount of the operating device 8. The operated amount may be considered as the signal strength of the operation command. The operated amount may be considered as the operating angle (tilting angle) of the left work lever 8A and the right work lever 8B. The controller 7 controls the actuators based on the operated amount of the operating device 8. The controller 7 receives multiple operation commands to operate multiple actuators and controls at least one of the multiple actuators.

[0027] In this embodiment, the operation command (operated quantity) is generated by operating the operating device 8, but the operation command may be generated by, for example, the controller 7. The operator may not operate the operating device 8, and the controller 7 may automatically generate the operation command. The operation command may be generated by a controller other than the controller 7. The other controller may be located outside the work machine 1. The operation command may be transmitted from the controller located outside the work machine 1 to the controller 7 mounted on the work machine 1. The operating device 8 may be located outside the work machine 1. The work machine 1 may be remotely controlled by a remote control device located outside the work machine 1. When the work machine 1 is remotely controlled by a remote control device, a remote controller connected to the remote control device may generate the operation command. The operation command generated by the remote controller may be transmitted to the controller 7 mounted on the work machine 1.

[0028] In the following description, the amount of force required to operate the boom cylinder 6A will be appropriately referred to as the boom operating amount. The amount of force required to operate the arm cylinder 6B will be appropriately referred to as the arm operating amount. The amount of force required to operate the bucket cylinder 6C will be appropriately referred to as the bucket operating amount. The amount of force required to operate the slewing motor 5 will be appropriately referred to as the slewing operating amount.

[0029] The boom control amount is an operation command for the boom cylinder 6A. The arm control amount is an operation command for the arm cylinder 6B. The bucket control amount is an operation amount for the bucket cylinder 6C. The slewing control amount is an operation command for the slewing motor 5.

[0030] In the following description, when the manipulated amount is zero, that is, when the operating device for operating a certain actuator is not operated, the manipulated amount is considered to be 0%. When the absolute value of the manipulated amount is at its maximum, the manipulated amount is considered to be +100% or -100%. An example of an operating device that can generate a manipulated amount of +100% and a manipulated amount of -100% is an electronic lever that can change the operating angle (tilting angle) in at least two opposite directions from the neutral position.

[0031] [Combined Operation] The operating device 8 may be operated so that at least two of the multiple actuators of the work machine 1 operate simultaneously. For example, the operating device 8 may be operated so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously. For example, the operating device 8 may be operated so that the boom cylinder 6A, the arm cylinder 6B and the bucket cylinder 6C operate simultaneously. For example, the operating device 8 may be operated so that the boom cylinder 6A, the arm cylinder 6B and the slewing motor 5 operate simultaneously. In the following description, operating the operating device 8 so that at least two actuators operate simultaneously will be appropriately referred to as a combined operation. Also, the operation of at least two actuators simultaneously will be appropriately referred to as a combined operation.

[0032] Furthermore, operating the control device 8 so that only one of the multiple actuators of the work machine 1 operates is appropriately referred to as "single-actuator operation." Single-actuator operation includes boom single-actuator operation, in which the control device 8 is operated so that only the boom cylinder 6A operates; arm single-actuator operation, in which the control device 8 is operated so that only the arm cylinder 6B operates; bucket single-actuator operation, in which the control device 8 is operated so that only the bucket cylinder 6C operates; and slewing single-actuator operation, in which the control device 8 is operated so that only the slewing motor 5 operates.

[0033] In single-actuator operation, the controller 7 acquires an operation command (operated variable) to operate one actuator. In combined operation, the controller 7 acquires multiple operation commands (operated variables) to operate multiple actuators simultaneously. In combined operation, the controller 7 acquires multiple operation commands (operated variables) to operate, for example, the first actuator and the second actuator simultaneously.

[0034] [Control System] Figure 3 is a schematic diagram showing the control system 13 of the work machine 1 according to the embodiment. The control system 13 includes a hydraulic system that operates using hydraulic fluid. As shown in Figure 3, the control system 13 includes a controller 7, an operating device 8, a power source 14, a pump 15, a tank 16, a control valve 17, a load pressure sensor 18, a pump passage 19, a suction passage 20, a bottom passage 21, a head passage 22, a slewing motor 5, and a work machine cylinder 6.

[0035] The power source 14 is the power source for the work machine 1. A diesel engine is an example of the power source 14. However, the power source 14 may also be an electric motor. The power source 14 is connected to the pump 15. The power source 14 drives the pump 15.

[0036] Pump 15 is a hydraulic pump that discharges hydraulic fluid. Pump 15 discharges hydraulic fluid supplied to the actuators of the work machine 1. The actuators include a slewing motor 5 and a work machine cylinder 6. In this embodiment, the hydraulic fluid discharged from pump 15 is distributed to each of the multiple actuators. Pump 15 draws in hydraulic fluid contained in tank 16 via suction passage 20. Pump 15 discharges the hydraulic fluid drawn in from tank 16 into pump passage 19. Pump 15 is a swashplate type variable displacement pump. The capacity [cc / rev] of pump 15 is changed by changing the angle of the swashplate of pump 15.

[0037] The control valve 17 includes a directional control valve that controls the flow rate and direction of the hydraulic fluid supplied from the pump 15 to the actuators of the work machine 1. The control valve 17 is located in the bottom passage 21 and the head passage 22, respectively. Multiple control valves 17 are provided to control the flow rate of the hydraulic fluid supplied from the pump 15 to each of the multiple actuators. In this embodiment, the control valve 17 includes a first control valve 17A that controls the flow rate and direction of the hydraulic fluid supplied from the pump 15 to the boom cylinder 6A, a second control valve 17B that controls the flow rate and direction of the hydraulic fluid supplied from the pump 15 to the arm cylinder 6B, a third control valve 17C that controls the flow rate and direction of the hydraulic fluid supplied from the pump 15 to the bucket cylinder 6C, and a fourth control valve 17D that controls the flow rate and direction of the hydraulic fluid supplied from the pump 15 to the swing motor 5. The first control valve 17A is located in the first bottom passage 21A and the first head passage 22A. The second control valve 17B is located in the second bottom passage 21B and the second head passage 22B. The third control valve 17C is located in the third bottom passage 21C and the third head passage 22C. The fourth control valve 17D is located in the first motor passage 21D and the second motor passage 22D.

[0038] The work implement cylinder 6 extends and retracts to operate the work implement 4 when hydraulic fluid is supplied from the pump 15. When hydraulic fluid from the pump 15 is supplied to the bottom chamber 61 of the work implement cylinder 6 via the control valve 17, and the hydraulic fluid from the head chamber 62 of the work implement cylinder 6 is discharged to the tank 16 via the control valve 17, the work implement cylinder 6 extends. When hydraulic fluid from the pump 15 is supplied to the head chamber 62 of the work implement cylinder 6 via the control valve 17, and the hydraulic fluid from the bottom chamber 61 of the work implement cylinder 6 is discharged to the tank 16 via the control valve 17, the work implement cylinder 6 retracts.

[0039] When hydraulic fluid from pump 15 is supplied to the bottom chamber 61 of boom cylinder 6A via the first control valve 17A, boom cylinder 6A extends and boom 4A moves upward. When hydraulic fluid from pump 15 is supplied to the head chamber 62 of boom cylinder 6A via the first control valve 17A, boom cylinder 6A retracts and boom 4A moves downward.

[0040] When the hydraulic oil from the pump 15 is supplied to the bottom chamber 61 of the arm cylinder 6B via the second control valve 17B, the arm cylinder 6B extends and the arm 4B performs a digging operation. When the hydraulic oil from the pump 15 is supplied to the head chamber 62 of the arm cylinder 6B via the second control valve 17B, the arm cylinder 6B contracts and the arm 4B performs a dumping operation.

[0041] When the hydraulic oil from the pump 15 is supplied to the bottom chamber 61 of the bucket cylinder 6C via the third control valve 17C, the bucket cylinder 6C extends and the bucket 4C performs a digging operation. When the hydraulic oil from the pump 15 is supplied to the head chamber 62 of the bucket cylinder 6C via the third control valve 17C, the bucket cylinder 6C contracts and the bucket 4C performs a dumping operation.

[0042] The swing motor 5 rotates to swing the swing body 3 when the hydraulic oil from the pump 15 is supplied. When the hydraulic oil from the pump 15 is supplied to the first port 51 of the swing motor 5 via the fourth control valve 17D and the hydraulic oil flowing out from the second port 52 of the swing motor 5 is discharged to the tank 16 via the fourth control valve 17D, the swing motor 5 rotates counterclockwise and the swing body 3 swings counterclockwise. When the hydraulic oil from the pump 15 is supplied to the second port 52 of the swing motor 5 via the fourth control valve 17D and the hydraulic oil flowing out from the first port 51 of the swing motor 5 is discharged to the tank 16 via the fourth control valve 17D, the swing motor 5 rotates clockwise and the swing body 3 swings clockwise.

[0043] The control valve 17 has a meter-in opening for controlling the flow rate of the hydraulic oil flowing into the actuator and a meter-out opening for controlling the flow rate of the hydraulic oil flowing out from the actuator.

[0044] When the hydraulic oil flows into the actuator from the bottom flow path 21, the meter-in opening of the control valve 17 controls the flow rate of the hydraulic oil supplied from the bottom flow path 21 to the actuator, and the meter-out opening of the control valve 17 controls the flow rate of the hydraulic oil flowing out from the actuator to the head flow path 22.

[0045] When hydraulic oil flows from the head flow path 22 into the actuator, the meter-in opening of the control valve 17 controls the flow rate of the hydraulic oil supplied from the head flow path 22 to the actuator, and the meter-out opening of the control valve 17 controls the flow rate of the hydraulic oil flowing out from the actuator to the bottom flow path 21.

[0046] The load pressure sensor 18 is a pressure sensor that detects the load acting on the actuator. The load pressure sensor 18 detects the load pressure acting on the actuator. The load pressure sensor 18 is provided in each of the bottom flow path 21 between the control valve 17 and the actuator and the head flow path 22 between the control valve 17 and the actuator. The load pressure sensor 18 provided in the bottom flow path 21 detects the pressure of the hydraulic oil in the bottom flow path 21 between the control valve 17 and the actuator. The load pressure sensor 18 provided in the head flow path 22 detects the pressure of the hydraulic oil in the head flow path 22 between the control valve 17 and the actuator. The detection data of the load pressure sensor 18 is transmitted to the controller 7.

[0047] A plurality of load pressure sensors 18 are provided to detect the load pressure acting on each of the plurality of actuators. In the embodiment, the load pressure sensor 18 includes a first load pressure sensor 18A that detects the load pressure of the boom cylinder 6A, a second load pressure sensor 18B that detects the load pressure of the arm cylinder 6B, a third load pressure sensor 18C that detects the load pressure of the bucket cylinder 6C, and a fourth load pressure sensor 18D that detects the load pressure of the swing motor 5.

[0048] The first load pressure sensor 18A provided in the first bottom flow path 21A detects the pressure of the first bottom flow path 21A between the first control valve 17A and the boom cylinder 6A. The first load pressure sensor 18A provided in the first head flow path 22A detects the pressure of the first head flow path 22A between the first control valve 17A and the boom cylinder 6A.

[0049] The second load pressure sensor 18B, located in the second bottom passage 21B, detects the pressure in the second bottom passage 21B between the second control valve 17B and the arm cylinder 6B. The second load pressure sensor 18B, located in the second head passage 22B, detects the pressure in the second head passage 22B between the second control valve 17B and the arm cylinder 6B.

[0050] The third load pressure sensor 18C, located in the third bottom passage 21C, detects the pressure in the third bottom passage 21C between the third control valve 17C and the bucket cylinder 6C. The third load pressure sensor 18C, located in the third head passage 22C, detects the pressure in the third head passage 22C between the third control valve 17C and the bucket cylinder 6C.

[0051] The fourth load pressure sensor 18D, located in the first motor passage 21D, detects the pressure in the first motor passage 21D between the fourth control valve 17D and the swing motor 5. The fourth load pressure sensor 18D, located in the second motor passage 22D, detects the pressure in the second motor passage 22D between the fourth control valve 17D and the swing motor 5.

[0052] When hydraulic fluid flows into the actuator from the bottom passage 21, the load pressure sensor 18 provided in the bottom passage 21 functions as a meter-in sensor that detects the meter-in pressure, which indicates the pressure of the hydraulic fluid flowing into the actuator, and the load pressure sensor 18 provided in the head passage 22 functions as a meter-out sensor that detects the meter-out pressure, which indicates the pressure of the hydraulic fluid flowing out of the actuator.

[0053] When hydraulic fluid flows into the actuator from the bottom passage 21, the load pressure sensor 18 provided in the bottom passage 21 detects the load pressure acting on the actuator. When hydraulic fluid flows into the actuator from the head passage 22, the load pressure sensor 18 provided in the head passage 22 detects the load pressure acting on the actuator.

[0054] [Controller] Figure 4 is a hardware configuration diagram showing a controller 7 according to an embodiment. The controller 7 includes a computer 12. The computer 12 includes a processor 12A such as a CPU (Central Processing Unit), a main memory 12B including non-volatile memory such as ROM (Read Only Memory) and volatile memory such as RAM (Random Access Memory), a storage 12C, an input / output interface 12D including input / output circuits, and a communication interface 12E including communication circuits. The functions of the controller 7 are stored in the storage 12C as a computer program 12F. The processor 12A reads the computer program 12F from the storage 12C, loads it into the main memory 12B, and executes processing according to the computer program 12F. The computer program 12F may be distributed to the computer 12 via a network.

[0055] Figure 5 is a functional block diagram showing a controller 7 according to an embodiment. The controller 7 outputs control commands to control at least the pump 15 and the control valve 17. The controller 7 is connected to an operating device 8, a monitor 9 including an input device 9B, a load pressure sensor 18, and a rotation sensor 30. The rotation sensor 30 detects the rotation state of the rotation body 3. The rotation state of the rotation body 3 includes whether or not it is rotating (whether or not it is rotating), the rotation angle of the rotation body 3 relative to the traveling body 2, and the rotation speed of the rotation body 3 relative to the traveling body 2. A potentiometer is exemplified as the rotation sensor 30.

[0056] The controller 7 has multiple storage units and multiple functional units. The functions of the storage units of the controller 7 are performed by the storage 12C. The functions of the functional units of the controller 7 are performed by the processor 12A. The storage units of the controller 7 include a correlation data storage unit 71, a priority storage unit 72, and a threshold storage unit 73. The functional units of the controller 7 include an operation variable acquisition unit 74, a high load determination unit 75, a calculation unit 76, a control unit 77, a correlation data modification unit 78, and a threshold modification unit 79.

[0057] The correlation data storage unit 71 stores correlation data showing the relationship between the manipulated amount for each of the multiple actuators and the target operating speed of the actuator. The correlation data is predetermined and stored in the correlation data storage unit 71. However, the correlation data may be determined arbitrarily.

[0058] Correlation data is used to determine the target operating speed of a target actuator among multiple actuators. There is a one-to-one correspondence between the target operating speed of the target actuator and the target flow rate of the hydraulic fluid supplied to it. The flow rate of the hydraulic fluid supplied to the actuator and the actuator's operating speed are substantially proportional. Determining the target operating speed of the target actuator includes determining the target flow rate for that actuator.

[0059] Figure 6 is a diagram illustrating correlation data according to an embodiment. In this embodiment, the actuator includes a boom cylinder 6A (first actuator), an arm cylinder 6B (second actuator), a bucket cylinder 6C (third actuator), and a slewing motor 5 (fourth actuator).

[0060] The correlation data includes first correlation data showing the relationship between the boom maneuver amount, the arm maneuver amount, and the target operating speed (operation command) of the boom cylinder 6A. The correlation data includes second correlation data showing the relationship between the boom maneuver amount, the bucket maneuver amount, and the target operating speed of the boom cylinder 6A. The correlation data includes third correlation data showing the relationship between the boom maneuver amount, the slewing maneuver amount, and the target operating speed of the boom cylinder 6A. Each of the first, second, and third correlation data is used to determine the target operating speed (target cylinder speed) of the boom cylinder 6A, which is the target actuator.

[0061] The correlation data includes a fourth correlation data showing the relationship between the arm operation amount, the boom operation amount, and the target operating speed of the arm cylinder 6B. The correlation data includes a fifth correlation data showing the relationship between the arm operation amount, the bucket operation amount, and the target operating speed of the arm cylinder 6B. The correlation data includes a sixth correlation data showing the relationship between the arm operation amount, the slewing operation amount, and the target operating speed of the arm cylinder 6B. The fourth, fifth, and sixth correlation data are each used to determine the target operating speed (target cylinder speed) of the arm cylinder 6B, which is the target actuator.

[0062] The correlation data includes a seventh correlation data showing the relationship between the bucket maneuver, the boom maneuver, and the target operating speed of the bucket cylinder 6C. The correlation data includes an eighth correlation data showing the relationship between the bucket maneuver, the arm maneuver, and the target operating speed of the bucket cylinder 6C. The correlation data includes a ninth correlation data showing the relationship between the bucket maneuver, the slewing maneuver, and the target operating speed of the bucket cylinder 6C. The seventh, eighth, and ninth correlation data are each used to determine the target operating speed (target cylinder speed) of the bucket cylinder 6C, which is the target actuator.

[0063] The correlation data includes a 10th correlation data showing the relationship between the slewing operation amount, the boom operation amount, and the target operating speed of the slewing motor 5. The correlation data includes a 11th correlation data showing the relationship between the slewing operation amount, the arm operation amount, and the target operating speed of the slewing motor 5. The correlation data includes a 12th correlation data showing the relationship between the slewing operation amount, the bucket operation amount, and the target operating speed of the slewing motor 5. Each of the 10th, 11th, and 12th correlation data is used to determine the target operating speed (target slewing speed) of the slewing motor 5, which is the target actuator.

[0064] In other words, the correlation data for determining the target operating speed of the target actuator shows the relationship between the amount of manipulation applied to the target actuator, the amount of manipulation applied to the actuator other than the target actuator, and the target operating speed of the target actuator when the target actuator and another actuator are operated in combination.

[0065] Figure 7 is a diagram illustrating the first correlation data according to the embodiment. Figure 8 is a diagram illustrating the fourth correlation data according to the embodiment. As shown in Figures 7 and 8, correlation data can be represented as three-dimensional map data. In Figure 7, the plane passing through the thick solid line represents the three-dimensional map data. On the plane representing the three-dimensional map data, there exists a line La and points Ra1 and Ra2. In Figure 8, the plane passing through the thick solid line represents the three-dimensional map data. On the plane representing the three-dimensional map data, there exists a line Lb and points Rb1 and Rb2.

[0066] When the arm operation amount for excavating arm 4B is set to a positive value, the arm operation amount for dumping arm 4B is set to a negative value, the boom operation amount for raising boom 4A is set to a positive value, and the boom operation amount for lowering boom 4A is set to a negative value, Figures 7 and 8 show the correlation data when both the arm operation amount and the boom operation amount are positive values.

[0067] As shown in Figure 7, the first correlation data shows the relationship between the boom operating amount, the arm operating amount, and the target operating speed of the boom cylinder 6A. The first correlation data is used to determine the target operating speed of the boom cylinder 6A when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously. In Figure 7, line La shows the target operating speed of the boom cylinder 6A when the boom operating amount and the arm operating amount are the same. Point Ra1 shows the target operating speed of the boom cylinder 6A when the boom operating amount and the arm operating amount are both 50%. Point Ra2 shows the target operating speed of the boom cylinder 6A when the boom operating amount and the arm operating amount are both 100%. In the example shown in Figure 7, when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously, the first correlation data is determined such that, when the boom operating amount is constant, the target operating speed of the boom cylinder 6A decreases as the absolute value of the arm operating amount increases.

[0068] As shown in Figure 8, the fourth correlation data shows the relationship between the arm operating amount, the boom operating amount, and the target operating speed of the arm cylinder 6B. The fourth correlation data is used to determine the target operating speed of the arm cylinder 6B when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously. In Figure 8, line Lb shows the target operating speed of the arm cylinder 6B when the boom operating amount and the arm operating amount are the same. Point Rb1 shows the target operating speed of the arm cylinder 6B when the boom operating amount and the arm operating amount are both 50%. Point Rb2 shows the target operating speed of the arm cylinder 6B when the boom operating amount and the arm operating amount are both 100%. In the example shown in Figure 8, when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously, the fourth correlation data is determined such that, when the arm operating amount is constant, the target operating speed of the boom cylinder 6A decreases as the absolute value of the boom operating amount increases.

[0069] The priority storage unit 72 stores the priority of multiple correlated data as described with reference to Figure 6. The priority is predetermined. The threshold storage unit 73 stores the threshold used to control the actuator.

[0070] The manipulated variable acquisition unit 74 acquires operation commands for the operating device 8. When the operating device 8 is operated in a complex manner, the manipulated variable acquisition unit 74 acquires multiple manipulated variables that operate multiple actuators simultaneously.

[0071] The high-load determination unit 75 determines whether a high-load combined operation state exists, where the load pressure of at least one actuator is equal to or greater than a pressure threshold, when the operating device 8 is being operated in a combined manner so that multiple actuators operate simultaneously. The high-load determination unit 75 can determine whether a high-load combined operation state exists based on the detection data from the load pressure sensor 18 and the amount of operation of the operating device 8. The pressure threshold is a predetermined value and is stored in the threshold storage unit 73.

[0072] The calculation unit 76 calculates an actuator operation command based on the relationship between multiple operation commands and the operation command of one actuator corresponding to the multiple operation commands. Calculating the actuator operation command includes calculating the target operating speed of the actuator. The calculation unit 76 calculates the target operating speed of the actuator based on multiple operation quantities and correlation data. The control unit 77 outputs a control command to control at least one of the pump 15 and the control valve 17 based on the target operating speed calculated by the calculation unit 76.

[0073] The correlation data modification unit 78 modifies the correlation data stored in the correlation data storage unit 71 based on the input data from the input device 9B. The threshold value modification unit 79 modifies the pressure threshold value if predetermined modification conditions are met. The threshold value modification unit 79 modifies the pressure threshold value based on the rotation state of the rotating body 3.

[0074] [Method for calculating target operating speed when operating devices are operated in combination] Next, we will explain how to calculate the target operating speed of the actuators when the operating device 8 is operated in combination so that two actuators operate simultaneously.

[0075] Figure 9 illustrates a method for calculating the target operating speed of an actuator when the operating device 8 is operated in combination to allow two actuators to operate simultaneously according to the embodiment. Below, an example of calculating the target operating speed of the arm cylinder 6B when the operating device 8 is operated in combination to allow the boom cylinder 6A and the arm cylinder 6B to operate simultaneously will be described. The actuator for which the target operating speed is calculated is the arm cylinder 6B. When calculating the target operating speed of the arm cylinder 6B when the operating device 8 is operated in combination to allow the boom cylinder 6A and the arm cylinder 6B to operate simultaneously, the three-dimensional map data described with reference to Figure 8 is used.

[0076] The three-dimensional map data described with reference to Figure 8 is generated by combining the two two-dimensional table data shown in Figure 9. That is, the three-dimensional map data described with reference to Figure 8 can be decomposed into two two-dimensional table data. The two two-dimensional table data include a first table data and a second table data. In Figure 9, the first table data shows the relationship between the arm operating amount and the target operating speed of the arm cylinder 6B during arm-only operation. The second table data shows the relationship between the boom operating amount and the gain. Each of the first and second table data can be arbitrarily determined in advance.

[0077] In the first table data, the arm operation amount for excavating arm 4B is set to a positive value, and the arm operation amount for dumping arm 4B is set to a negative value. In the second table data, the boom operation amount for raising boom 4A is set to a positive value, and the boom operation amount for lowering boom 4A is set to a negative value.

[0078] In the second table data, the manipulated variables are defined as a first positive value P1, a second positive value P2, a first negative value N1, and a second negative value N2. The first positive value P1 and the second positive value P2 are positive values ​​greater than 0%. The second positive value P2 is greater than the first positive value P1. The first negative value N1 and the second negative value N2 are negative values ​​less than 0%. The second negative value N2 is less than the first negative value N1. The absolute value of the second negative value N2 is greater than the absolute value of the first negative value N1. Between the first positive value P1 and the first negative value N1, the gain is 1. Between the first positive value P1 and the second positive value P2, the gain decreases as the manipulated variable increases. Between the second positive value P2 and 100%, the gain is a constant value less than 1. Between the first negative value N1 and the second negative value N2, the gain decreases as the absolute value of the manipulated variable increases. Between the second positive value P2 and -100%, the gain is a constant value less than 1.

[0079] The operation amount acquisition unit 74 acquires arm operation amount Aa and boom operation amount Ab as multiple operation amounts. Based on the multiple operation amounts, the first table data and the second table data, the calculation unit 76 calculates the target operating speed Va_b of the arm cylinder 6B when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously.

[0080] The calculation unit 76 calculates the target operating speed Va of the arm cylinder 6B during arm-only operation based on the arm operation amount Aa and the first table data. For example, when the arm operation amount Aa for operating arm 4B is input into the first table data, the target operating speed Va during arm-only operation is output.

[0081] The calculation unit 76 calculates a gain Gb for determining the target operating speed Va_b of the arm cylinder 6B based on the boom operating amount Ab and the second table data. When the boom operating amount Ab for operating the boom 4A is input into the second table data, the gain Gb for determining the target operating speed Va_b of the arm cylinder 6B is output.

[0082] In this embodiment, the calculation unit 76 calculates the target operating speed Va_b of the arm cylinder 6B when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously, by multiplying the target operating speed Va in arm-only operation by a gain Gb determined based on the boom operating amount Ab.

[0083] As explained above, when the control device 8 is operated in combination to operate two actuators simultaneously, the target operating speeds of each of the two actuators are calculated based on the two control quantities and correlation data (3D map data). The correlation data shows the relationship between the control quantity for the target actuator for which the target operating speed is calculated, the control quantity for an actuator other than the target actuator, and the target operating speed of the target actuator. By calculating the target operating speeds of each of the two actuators based on multiple control quantities and correlation data, the target operating speed for operating the work machine 1 in accordance with the intentions of the operator who is performing the combined operation of the control device 8 is calculated. The work machine 1, controlled based on the target operating speed, can operate in accordance with the intentions of the operator who is performing the combined operation of the control device 8.

[0084] [Method for Calculating Target Operating Speed ​​Considering Priority] Next, a method for calculating the target operating speed of an actuator when the operating device 8 is operated in a combined manner so that at least three actuators operate simultaneously will be described. When the operating device 8 is operated in a combined manner so that at least three actuators operate simultaneously, correlation data is adjusted based on the priority stored in the priority storage unit 72. When the operating amount acquisition unit 74 acquires multiple operating amounts that operate the first actuator (target actuator), the second actuator, and the third actuator simultaneously, the calculation unit 76 calculates the target operating speed of the first actuator (target actuator) based on the multiple operating amounts and the correlation data adjusted based on the priority.

[0085] Figure 10 is a diagram illustrating the priority according to the embodiment. Multiple correlation data are stored in the priority storage unit 72 with predetermined priorities. In this embodiment, priority refers to the priority of use of correlation data used when calculating the target operating speed of the target actuator.

[0086] As described above, the correlation data for determining the target operating speed of the target actuator shows the relationship between multiple manipulator values ​​when the target actuator and another actuator are operated in combination, and the target operating speed of the target actuator. The priority is determined based on the other actuator. In this embodiment, the correlation data where the other actuator is the boom cylinder 6A has the highest priority, the correlation data where the other actuator is the arm cylinder 6B has the second highest priority, the correlation data where the other actuator is the bucket cylinder 6C has the third highest priority, and the correlation data where the other actuator is the slewing motor 5 has the fourth highest priority.

[0087] In other words, as shown in Figure 10, when the target actuator is a boom cylinder 6A, the priority of the first correlation data is the highest among the first, second, and third correlation data used to determine the target operating speed of the boom cylinder 6A, followed by the second correlation data, and finally the third correlation data.

[0088] When the target actuator is the arm cylinder 6B, among the fourth, fifth, and sixth correlation data used to determine the target operating speed of the arm cylinder 6B, the fourth correlation data has the highest priority, followed by the fifth correlation data, and the sixth correlation data has the lowest priority.

[0089] When the target actuator is a bucket cylinder 6C, among the seventh, eighth, and ninth correlation data used to determine the target operating speed of the bucket cylinder 6C, the seventh correlation data has the highest priority, followed by the eighth correlation data, then the ninth correlation data, and finally the tenth correlation data.

[0090] When the target actuator is a slewing motor 5, among the 10th, 11th, and 12th correlation data used to determine the target operating speed of the slewing motor 5, the 10th correlation data has the highest priority, followed by the 11th correlation data, and finally the 12th correlation data has the lowest priority.

[0091] For example, when the operation amount acquisition unit 74 acquires multiple operation amounts that simultaneously operate the boom cylinder 6A, arm cylinder 6B, bucket cylinder 6C, and swing motor 5, the calculation unit 76 calculates the target operating speed of the arm cylinder 6B based on the multiple operation amounts acquired by the operation amount acquisition unit 74 and correlation data adjusted based on the priority shown in Figure 10.

[0092] <First Example of Method for Calculating Target Operating Speed ​​Considering Priority> Below, a first example of a method for calculating the target operating speed of an actuator when the operating device 8 is operated in a complex manner so that at least three actuators operate simultaneously will be described. In the first example, for example, when the first correlation data is set to have a higher priority than the second correlation data, the calculation unit 76, when it obtains multiple operation commands to operate the first actuator and the second actuator simultaneously, calculates the target operating speed of the first actuator based on the multiple operation commands and the first correlation data, regardless of the content of the operation command for the third actuator. When the calculation unit 76 obtains multiple operation commands to operate the first actuator and the third actuator simultaneously and not operate the second actuator, it calculates the target operating speed of the first actuator based on the multiple operation commands and the second correlation data.

[0093] Figure 11 illustrates a first example of a method for calculating the target operating speed of actuators when the operating device 8 is operated in combination so that at least two actuators operate simultaneously according to the embodiment.

[0094] Referring to Figure 11, an example will be described of calculating the target operating speed of the arm cylinder 6B when the operating device 8 is operated in a combined manner so that multiple actuators operate simultaneously. The actuator for which the target operating speed is calculated is the arm cylinder 6B. As described above, when the target actuator is the arm cylinder 6B, among the fourth, fifth, and sixth correlation data for determining the target operating speed of the arm cylinder 6B, the fourth correlation data is given a higher priority than the fifth correlation data, and the fifth correlation data is given a higher priority than the sixth correlation data.

[0095] For example, if the operation amount acquisition unit 74 acquires multiple operation amounts that simultaneously operate the target actuator, the arm cylinder 6B, the boom cylinder 6A, the bucket cylinder 6C, and the slewing motor 5, the calculation unit 76 calculates the target operating speed of the arm cylinder 6B based on the multiple operation amounts acquired by the operation amount acquisition unit 74 and the fourth correlation data which has the highest priority when the target cylinder is the arm cylinder 6B. That is, as shown in Figure 11, if the arm operation amount that operates the arm cylinder 6B is acquired, the boom operation amount that operates the boom cylinder 6A is acquired, the bucket operation amount that operates the bucket cylinder 6C is acquired, and the slewing operation amount that operates the slewing motor 5 is acquired, the fourth correlation data is used. The target operating speed of the arm cylinder 6B reflects the arm operation amount and the boom operation amount, but does not reflect the bucket operation amount and the slewing operation amount.

[0096] For example, if the operation amount acquisition unit 74 acquires multiple operation amounts that simultaneously operate the target actuator, the arm cylinder 6B, the bucket cylinder 6C, and the slewing motor 5, the calculation unit 76 calculates the target operating speed of the arm cylinder 6B based on the multiple operation amounts acquired by the operation amount acquisition unit 74 and the fifth correlation data, which has the second highest priority after the fourth correlation data when the target cylinder is the arm cylinder 6B. That is, as shown in Figure 11, if the arm operation amount that operates the arm cylinder 6B is acquired, the boom operation amount that does not operate the boom cylinder 6A is acquired, the bucket operation amount that operates the bucket cylinder 6C is acquired, and the slewing operation amount that operates the slewing motor 5 is acquired, the fifth correlation data is used. The target operating speed of the arm cylinder 6B reflects the arm operation amount and the bucket operation amount, but does not reflect the slewing operation amount. If the boom operation amount is zero, the boom operation amount is also not reflected in the target operating speed of the arm cylinder 6B.

[0097] For example, if the operation amount acquisition unit 74 acquires multiple operation amounts that simultaneously operate the target actuator, the arm cylinder 6B, and the slewing motor 5, the calculation unit 76 calculates the target operating speed of the arm cylinder 6B based on the multiple operation amounts acquired by the operation amount acquisition unit 74 and the sixth correlation data, which has the second highest priority after the fifth correlation data when the target cylinder is the arm cylinder 6B. That is, as shown in Figure 11, if an arm operation amount that operates the arm cylinder 6B is acquired, a boom operation amount that does not operate the boom cylinder 6A is acquired, a bucket operation amount that does not operate the bucket cylinder 6C is acquired, and a slewing operation amount that operates the slewing motor 5 is acquired, the sixth correlation data is used. The target operating speed of the arm cylinder 6B reflects the arm operation amount and the slewing operation amount. If the boom operation amount and bucket operation amount are zero, the boom operation amount and bucket operation amount are not reflected in the target operating speed of the arm cylinder 6B.

[0098] As shown in Figure 11, the fourth correlation data is used when the arm operation amount for operating the arm cylinder 6B is obtained, the boom operation amount for operating the boom cylinder 6A is obtained, the bucket operation amount for operating the bucket cylinder 6C is obtained, and the slewing operation amount without operating the slewing motor 5 is obtained.

[0099] As shown in Figure 11, the fourth correlation data is used when the arm operation amount that operates the arm cylinder 6B is obtained, the boom operation amount that operates the boom cylinder 6A is obtained, the bucket operation amount that does not operate the bucket cylinder 6C is obtained, and the slewing operation amount that operates the slewing motor 5 is obtained.

[0100] As shown in Figure 11, the fourth correlation data is used when the arm operation amount that operates the arm cylinder 6B is obtained, the boom operation amount that operates the boom cylinder 6A is obtained, the bucket operation amount that does not operate the bucket cylinder 6C is obtained, and the slewing operation amount that does not operate the slewing motor 5 is obtained.

[0101] As shown in Figure 11, the fifth correlation data is used when an arm operation amount that operates the arm cylinder 6B is obtained, a boom operation amount that does not operate the boom cylinder 6A is obtained, a bucket operation amount that operates the bucket cylinder 6C is obtained, and a slewing operation amount that does not operate the slewing motor 5 is obtained.

[0102] <Second Example of Method for Calculating Target Operating Speed ​​Considering Priority> Below, a second example of a method for calculating the target operating speed of actuators when the operating device 8 is operated in a combined manner so that at least two actuators operate simultaneously will be described. In the second example, for example, if the first correlation data has a higher priority than the second correlation data, the calculation unit 76 modifies the first correlation data based on the operation command for the third actuator and the second correlation data if the operation command for the second actuator is within a specified range that includes an operation command value that does not operate the second actuator. The calculation unit 76 calculates the target operating speed of the first actuator based on the multiple operation commands and the modified first correlation data. If the operation command for the second actuator is outside the specified range, the calculation unit 76 calculates the target operating speed of the first actuator based on the multiple operation commands and the first correlation data.

[0103] In the second example, for example, if the first correlation data is given a higher priority than the second correlation data, and the operation amount acquisition unit 74 acquires multiple operation amounts that simultaneously operate the first actuator (target actuator), the second actuator, and the third actuator among multiple actuators, the calculation unit 76 calculates the target operating speed of the first actuator based on the multiple operation amounts and the first correlation data corrected based on the second correlation data, if the operation amount that operates the second actuator is within a specified range including zero. If the operation amount that operates the second actuator is outside the specified range, the calculation unit 76 calculates the target operating speed of the first actuator based on the multiple operation amounts and the first correlation data.

[0104] Figure 12 illustrates a second example of a method for calculating the target operating speed of actuators when the operating device 8 is operated in a combined manner so that at least two actuators operate simultaneously according to the embodiment.

[0105] Referring to Figure 12, an example will be described of calculating the target operating speed of the arm cylinder 6B when the operating device 8 is operated in a combined manner so that the boom cylinder 6A, arm cylinder 6B, bucket cylinder 6C, and slewing motor 5 operate simultaneously. The actuator for which the target operating speed is calculated is the arm cylinder 6B. As described above, when the target actuator is the arm cylinder 6B, among the fourth, fifth, and sixth correlation data for determining the target operating speed of the arm cylinder 6B, the fourth correlation data is given a higher priority than the fifth correlation data, and the fifth correlation data is given a higher priority than the sixth correlation data.

[0106] As shown in Figure 12, the fourth correlation data, the fifth correlation data, and the sixth correlation data each include the second table data as described with reference to Figure 9. The fourth correlation data includes the first table data and the second table data.

[0107] The second table of the fourth correlation data shows the relationship between boom control amount and gain. In the second table of the fourth correlation data, the boom control amount required to raise boom 4A is considered a positive value, and the boom control amount required to lower boom 4A is considered a negative value.

[0108] The second table of the fifth correlation data shows the relationship between bucket manipulation amount and gain. In the second table of the fifth correlation data, the bucket manipulation amount required to perform an excavation operation on bucket 4C is defined as a positive value, and the bucket manipulation amount required to perform a dumping operation on bucket 4C is defined as a negative value.

[0109] The second table of the sixth correlation data shows the relationship between the rotation operation amount and the gain. In the second table of the sixth correlation data, the rotation operation amount for turning the rotating body 3 to the left is set as a positive value, and the rotation operation amount for turning the rotating body 3 to the right is set as a negative value.

[0110] The calculation unit 76 calculates a gain Gt for correcting the fifth correlation data based on the rotation operation amount At and the second table data of the sixth correlation data. For example, when the rotation operation amount At for rotating the rotating body 3 to the left is input into the second table data of the sixth correlation data, a gain Gt for correcting the second table data of the fifth correlation data is output.

[0111] In the second table data of the fifth correlation data, the gain within the specified range of the bucket manipulation variable, including zero, between the second negative value N2 and the second positive value P2 is modified by the gain Gt. In the second table data of the fifth correlation data, the unmodified gain between the first positive value P1 and the first negative value N1 is 1. The gain between the first positive value P1 and the first negative value N1 is modified from 1 to Gt. Between the first positive value P1 and the second positive value P2, the gain decreases from Gt as the manipulation variable increases. Between the first negative value N1 and the second negative value N2, the gain decreases from Gt as the absolute value of the manipulation variable increases. Between the second positive value P2 and 100%, the gain is not modified. Between the second positive value P2 and -100%, the gain is not modified. The specified range of the bucket manipulation variable between the second negative value N2 and the second positive value P2 corresponds to the fine-tuning range of the bucket manipulation variable. The gain within the specified range of the second table data of the fifth correlation data is affected by the gain Gt. Gains outside the specified range for the second table data of the fifth correlation data are not affected by the gain Gt.

[0112] Note that the second table data of the fifth correlation data shown in Figure 12 is just an example. For example, if the absolute value of the manipulated variable increases between the first positive value P1 and the second positive value P2, the gain may increase from Gt. Similarly, if the absolute value of the manipulated variable increases between the first negative value N1 and the second negative value N2, the gain may increase from Gt.

[0113] The calculation unit 76 calculates a gain Gk for correcting the fourth correlation data based on the bucket operation amount Ak and the second table data of the corrected fifth correlation data. For example, when the bucket operation amount Ak for excavating bucket 4C is input into the second table data of the corrected fifth correlation data, a gain Gk for correcting the second table data of the fourth correlation data is output.

[0114] In the second table data of the fourth correlation data, the gain within the specified range of the boom control amount, including zero, between the second negative value N2 and the second positive value P2, is modified by the gain Gk. In the second table data of the fourth correlation data, the unmodified gain between the first positive value P1 and the first negative value N1 is 1. The gain between the first positive value P1 and the first negative value N1 is modified from 1 to Gk. Between the first positive value P1 and the second positive value P2, the gain decreases from Gk as the control amount increases. Between the first negative value N1 and the second negative value N2, the gain decreases from Gk as the absolute value of the control amount increases. Between the second positive value P2 and 100%, the gain is not modified. Between the second positive value P2 and -100%, the gain is not modified. The specified range of the boom control amount between the second negative value N2 and the second positive value P2 corresponds to the fine control range of the boom control amount. The gain within the specified range of the second table data of the fourth correlation data is affected by the gain Gk. Gains outside the specified range for the second table data of the fourth correlation data are not affected by the gain Gk.

[0115] Note that the second table data of the fourth correlation data shown in Figure 12 is just an example. For example, if the absolute value of the manipulated variable increases between the first positive value P1 and the second positive value P2, the gain may increase from Gt. Similarly, if the absolute value of the manipulated variable increases between the first negative value N1 and the second negative value N2, the gain may increase from Gt.

[0116] The calculation unit 76 calculates a gain Gb for determining the target operating speed Va_b of the arm cylinder 6B based on the boom operation amount Ab and the second table data of the corrected fourth correlation data. For example, when the boom operation amount Ab for raising and operating the boom 4A is input into the second table data of the corrected fourth correlation data, the gain Gb for determining the target operating speed Va_b of the arm cylinder 6B is output. The calculation unit 76 calculates the target operating speed Va_b of the arm cylinder 6B by multiplying the target operating speed Va in arm-only operation by the gain Gb determined based on the boom operation amount Ab.

[0117] As explained with reference to Figure 12, if the boom operating amount Ab that operates the boom cylinder 6A is within a specified range including zero between the second negative value N2 and the second positive value P2, the calculation unit 76 calculates the target operating speed Va_b of the arm cylinder 6B based on the boom operating amount Ab and the fourth correlation data modified based on the gain Gk of the fifth correlation data. If the boom operating amount Ab is outside the specified range, the calculation unit 76 calculates the target operating speed Va_b of the arm cylinder 6B based on the boom operating amount Ab and the fourth correlation data unaffected by the gain Gk.

[0118] In the second example, as explained with reference to Figure 12, when the bucket or boom maneuver amount, which has a higher priority, is slightly increased, the sudden and abrupt decrease in gain that can occur in the first example is eliminated, and the gain Gb for determining the target operating speed Va_b of the arm cylinder 6B can change continuously in accordance with the continuous change in the higher priority maneuver amount. In other words, the gain within the specified range continuously asymptotically approaches the gain outside the specified range in accordance with the maneuver amount.

[0119] [Control Method] Figure 13 is a flowchart showing the control method of the work machine 1 according to the embodiment. The calculation unit 76 acquires correlation data from the correlation data storage unit 71 (step SA1). The manipulated variable acquisition unit 74 acquires multiple manipulated variables (step SA2).

[0120] When the manipulated amount acquisition unit 74 acquires multiple manipulated amounts that operate at least two actuators simultaneously, the calculation unit 76 adjusts the correlation data for calculating the target operating speed of the target actuator based on the priority stored in the priority storage unit 72 (step SA3).

[0121] The calculation unit 76 calculates the target operating speed of each of the multiple actuators based on the multiple manipulated variables acquired by the manipulated variable acquisition unit 74 and correlation data adjusted based on priority (step SA4).

[0122] The control unit 77 outputs a control command so that the ratio of the actual operating speeds of the multiple actuators becomes the ratio of the target operating speeds calculated in step SA4. The control unit 77 calculates the target flow rate of the hydraulic fluid supplied to each of the multiple actuators by multiplying the target operating speed calculated in step SA4 by the pressure-receiving area of ​​the hydraulic actuator. The actuator pressure-receiving area refers to the area of ​​the piston facing the cylinder rod chamber or head chamber in the case of a cylinder, and the displacement volume of the motor in the case of a hydraulic motor. The control unit 77 outputs a control command to control the control valve 17 so that the ratio of the flow rates of the hydraulic fluid supplied to each of the multiple actuators becomes the ratio of the target flow rates (step SA5).

[0123] [Effect] As described above, when the control device 8 is operated in a complex manner so that multiple actuators operate simultaneously, the target operating speed of each of the multiple actuators is calculated based on the multiple control quantities and correlation data (3D map data). The correlation data shows the relationship between the control quantity for the target actuator for which the target operating speed is calculated, the control quantity for an actuator other than the target actuator, and the target operating speed of the target actuator. By calculating the target operating speed of each of the multiple actuators based on the multiple control quantities and correlation data, the target operating speed for operating the work machine 1 in accordance with the intention of the operator who is operating the control device 8 in a complex manner is calculated. The work machine 1 controlled based on the calculated target operating speed can operate in accordance with the intention of the operator who is operating the control device 8 in a complex manner.

[0124] Figure 14 is a diagram illustrating the effect of the control method for the work machine 1 according to the embodiment. Figure 14 is a diagram illustrating the amount of operation of the operating device 8 and the operation of the work machine 4 in the embodiment and comparative example when performing digging work to level the ground using the work machine 4. In the graphs for the embodiment and comparative example, the horizontal axis is time, and the vertical axis is the amount of operation of the operating device 8 or the cutting edge position of the bucket 4C. In the graphs for the embodiment and comparative example, line Lc is the amount of lever operation, line Ld is the amount of arm operation, and line Le is the cutting edge position of the bucket 4C. In digging work, the boom 4A moves upward while the arm 4B digs. In the graph shown in Figure 14, the boom operation amount for moving the boom 4A upward is set as a positive value, and the arm operation amount for moving the arm 4B digs is set as a positive value.

[0125] In both the examples and comparative examples, the operating device 8 is operated in combination so that the boom operating amount and the arm operating amount are both 100%.

[0126] The embodiment shows an example in which, as described in the embodiment described above, the target operating speeds of the boom cylinder 6A and the arm cylinder 6B are calculated based on multiple manipulated variables and correlated data (3D map data), and the boom cylinder 6A and the arm cylinder 6B are controlled based on the calculated target operating speeds.

[0127] The comparative example shows a case where correlation data (3D map data) is not used, and the boom cylinder 6A and arm cylinder 6B are controlled so that their operating speeds are proportional to the operating speeds of each cylinder during individual operation. In other words, in the comparative example, the cutting edge position of the bucket 4C is determined by the combined operation of the boom cylinder 6A and the arm cylinder 6B when operated individually.

[0128] In this embodiment, when the operating device 8 is operated in combination so that the boom operating amount and the arm operating amount are both 100%, the cutting edge position of the bucket 4C moves almost parallel to the horizontal plane. As shown in the right-hand figure of Figure 14, the target trajectory of the cutting edge of the bucket 4C is parallel to the horizontal plane, and the actual trajectory of the cutting edge of the bucket 4C approximates the target trajectory.

[0129] In the comparative example, when the operating device 8 is operated in combination so that the boom operating amount and the arm operating amount are both 100%, the cutting edge position of the bucket 4C moves non-parallel to the horizontal plane. As shown in the right-hand figure of Figure 14, the actual trajectory of the cutting edge of the bucket 4C is below the target trajectory, causing the bucket 4C to dig into the ground.

[0130] As shown in Figure 14, in this embodiment, a target operating speed is calculated based on correlation data (3D map data) so that the work machine 4 operates in accordance with the intentions of the operator performing the combined operation of the control device 8. By controlling the work machine 4 based on the calculated target operating speed, the work machine 4 of the work machine 1 can operate in accordance with the intentions of the operator performing the combined operation of the control device 8.

[0131] In the comparative example, the supply flow rate during combined operation is approximately proportional to the supply flow rate during single operation; therefore, the relationship between the manipulated amount and the operating speed during combined operation depends on the relationship between the manipulated amount and the operating speed during single operation. Furthermore, the relationship between the manipulated amount and the operating speed in the comparative example is often determined by considering the trade-off between operability during single operation and operability during combined operation; therefore, operability during combined operation is often not optimized.

[0132] In this embodiment, suitable speed control becomes possible in both the high-speed and low-speed ranges of the working machine 4's operating speed, thereby improving the position controllability of the working machine 4 during combined operations. For example, the magnitude of the actuator speed, the speed ratio of multiple actuators, and the speed gradient can be suitably controlled.

[0133] Furthermore, in the embodiment, when the operating device 8 is operated in combination so that at least three actuators operate simultaneously, correlation data is adjusted based on a predetermined priority. Based on the multiple operating amounts and the correlation data adjusted based on the priority, the target operating speed of the actuators is calculated, so that the work machine 1 can operate in accordance with the intentions of the operator who performs the combined operation of the operating device 8. For example, when the operating amounts of the boom cylinder 6A, arm cylinder 6B, and bucket cylinder 6C are all the same, the working machine cylinders 6 that affect the cutting edge position of the bucket 4C are most influenced by the boom cylinder 6A (1st), then the arm cylinder 6B (2nd), and finally the bucket cylinder 6C (3rd). Also, the influence of the slewing motor 5 on the cutting edge position of the bucket 4C is small. As described above, the priority is determined based on an actuator other than the target actuator. Therefore, when controlling the cutting edge position of the bucket 4C is important in a combined operation, the priority is set such that the correlation data where another actuator is the boom cylinder 6A has the highest priority, the correlation data where another actuator is the arm cylinder 6B has the second highest priority, the correlation data where another actuator is the bucket cylinder 6C has the third highest priority, and the correlation data where another actuator is the slewing motor 5 has the fourth highest priority. This allows the cutting edge position of the bucket 4C to be moved in accordance with the operator's intentions.

[0134] [Changing the Correlation Data] The correlation data can be changed arbitrarily. Figure 15 is a diagram illustrating a method for changing the correlation data according to an embodiment. The correlation data changing unit 78 can change the correlation data stored in the correlation data storage unit 71 based on input data from the input device 9B. The feel of operating the operating device 8 is determined by the correlation data. The operator can change the correlation data arbitrarily by operating the input device 9B. The operator can change the value of the first positive value P1, the value of the second positive value P2, the value of the first negative value N1, and the value of the second negative value N2. The operator can also change the gain in the first positive value P1, the gain in the second positive value P2, the gain in the first negative value N1, and the gain in the second negative value N2. The correlation data may also be changed based on input data from an external device 90 located outside the work machine 1. The input data from the external device 90 may be input to the controller 7 via a communication device.

[0135] [Control method when the work machine cylinder reaches the stroke end] Next, a control method for the work machine 1 when at least one work machine cylinder 6 reaches the stroke end, in a case where the operating device 8 is operated in combination to operate multiple work machine cylinders 6 simultaneously, will be described. The stroke end refers to the end position of the movable range of the rod of the work machine cylinder 6. That is, the stroke end refers to the position of the rod when the work machine cylinder 6 is most retracted or when the rod is most extended.

[0136] In the following section, we will describe the control method when the work implement cylinder 6 has reached the end of its stroke. However, the same applies to situations where the work implement cylinder 6 is difficult to move due to external resistance such as soil resistance, or when a large amount of energy is consumed to move the work implement cylinder 6.

[0137] Figure 16 is a schematic diagram showing the work machine cylinder 6 according to the embodiment. Figure 16 corresponds to a diagram that extracts a part of the control system 13 described with reference to Figure 3. For example, when the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously, when the boom cylinder 6A reaches the stroke end, the boom cylinder 6A becomes immobile. If the combined operation of the operating device 8 is not released even though the boom cylinder 6A has reached the stroke end and is immobile, and hydraulic fluid continues to be supplied to the boom cylinder 6A, the pressure of the hydraulic fluid supplied to the boom cylinder 6A will increase, a large amount of fluid energy will be wasted, and the fluid energy supplied to the arm cylinder 6B will decrease. Therefore, the amount of hydraulic fluid supplied to the arm cylinder 6B will not increase, the operating speed of the arm cylinder 6B will decrease, and as a result, the work efficiency will decrease. For this reason, when the boom cylinder 6A has reached the stroke end and is immobile, the controller 7 outputs a control command to reduce the flow rate of hydraulic fluid supplied to the boom cylinder 6A. Outputting a control command to reduce the flow rate of hydraulic fluid supplied to the boom cylinder 6A includes outputting a control command to reduce the operating speed of the boom cylinder 6A.

[0138] In this embodiment, the high-load determination unit 75 determines whether a high-load combined operation state exists in which the load on at least one actuator is greater than or equal to a load threshold when the operating device 8 is being operated in a combined manner so that multiple actuators are operating simultaneously. The high-load determination unit 75 determines that the actuator whose load is greater than or equal to the load threshold is a high-load actuator that has reached its stroke end and can no longer move. The control unit 77 outputs a control command to reduce the operating speed of the high-load actuator. The control unit 77 intervenes in speed control to reduce the operating speed of the high-load actuator.

[0139] In this embodiment, the high-load determination unit 75 determines whether a high-load combined operation state exists in which the load pressure of at least one actuator is equal to or greater than a pressure threshold when the operating device 8 is being operated in a combined manner so that multiple actuators are operating simultaneously. The high-load determination unit 75 determines that the actuator whose load pressure is equal to or greater than the pressure threshold is a high-load actuator that has reached its stroke end and is no longer able to move. The control unit 77 outputs a control command to reduce the flow rate of hydraulic fluid supplied to the high-load actuator. The control unit 77 intervenes in speed control to reduce the flow rate of hydraulic fluid supplied to the high-load actuator.

[0140] Figure 17 is a flowchart showing the control method for the work machine 1 according to the embodiment. Below, the control method when the boom cylinder 6A reaches the stroke end will be described in the case where the operating device 8 is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously.

[0141] The high load determination unit 75 acquires the load pressure of the work machine cylinder 6. That is, the high load determination unit 75 acquires the detection data of the load pressure sensor 18. In this embodiment, the high load determination unit 75 acquires the detection data of the first load pressure sensor 18A and the second load pressure sensor 18B (step SB1).

[0142] The maneuvering amount acquisition unit 74 acquires multiple maneuvering amounts of the operating device 8, which is operated in combination so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously (step SB2).

[0143] The high-load determination unit 75 determines whether a high-load combined operation state exists, where the load pressure of at least one of the work machine cylinders 6, the boom cylinder 6A and the arm cylinder 6B, is equal to or greater than a predetermined pressure threshold, while the operating device 8 is operated so that the boom cylinder 6A and the arm cylinder 6B operate simultaneously. The pressure threshold is a predetermined value and is stored in the threshold storage unit 73 (step SB3).

[0144] In step SB3, if it is determined that, for example, the load pressure of the boom cylinder 6A is equal to or greater than a predetermined pressure threshold (step SB3: Yes), the control unit 77 intervenes to control the first control valve 17A, which controls the flow rate of the hydraulic fluid supplied to the boom cylinder 6A (step SB4).

[0145] Intervention control of the control valve 17 means controlling the control valve 17 so that it operates under predetermined conditions while the operating device 8 is being operated. In other words, intervention control of the first control valve 17A means that, while the boom operating amount is being acquired by the operating amount acquisition unit 74, the control unit 77 outputs a control command so that the first control valve 17A operates under predetermined conditions, regardless of the boom operating amount.

[0146] The control unit 77 outputs a control command to intervene and control the first control valve 17A so that the flow rate of hydraulic fluid supplied to the boom cylinder 6A, which is a high-load actuator, decreases. In other words, the control unit 77 outputs a control command so that the meter-in opening area of ​​the first control valve 17A becomes smaller.

[0147] If the high-load determination unit 75 determines in step SB3 that a high-load combined operation state is in effect, the control unit 77 outputs a control command to reduce the flow rate of hydraulic fluid supplied to the boom cylinder 6A, based on the load pressure of the boom cylinder 6A, which is a high-load actuator, and the amount of arm movement that operates the arm cylinder 6B, which is a low-load actuator whose load pressure is below the pressure threshold. Specifically, the larger the arm movement amount, the greater the amount the control unit 77 reduces the flow rate of hydraulic fluid supplied to the boom cylinder 6A. In other words, the larger the target operating speed of the arm cylinder 6B, the greater the reduction in the operating speed of the boom cylinder 6A. Furthermore, the larger the load pressure of the boom cylinder 6A, the greater the flow rate of hydraulic fluid supplied to the boom cylinder 6A. In other words, the larger the load pressure of the boom cylinder 6A, the greater the reduction in the operating speed of the boom cylinder 6A. When the arm operation amount is large, the flow rate of hydraulic fluid to be supplied to the arm cylinder 6B is large, so the meter-in opening area of ​​the first control valve 17A is made sufficiently small to limit the flow rate of hydraulic fluid supplied to the boom cylinder 6A so that the flow rate of hydraulic fluid supplied to the arm cylinder 6B is large. When the load pressure of the boom cylinder 6A is large, the operating speed of the boom cylinder 6A may decrease, so the meter-in opening area of ​​the first control valve 17A is made small to limit the flow rate of hydraulic fluid supplied to the boom cylinder 6A.

[0148] Figure 18 is a diagram illustrating a method for calculating the target flow rate of hydraulic fluid supplied to the boom cylinder 6A when it is determined that a high-load combined operation state is in place according to the embodiment. The 13th correlation data shown by line Lf and the 14th correlation data shown by line Lg in Figure 18 are predetermined and stored in the correlation data storage unit 71. The 13th correlation data shows the relationship between the arm operation amount that operates the arm cylinder 6B, which is a low-load actuator, and the first adjustment gain. The 14th correlation data shows the relationship between the load pressure of the boom cylinder 6A, which is a high-load actuator, and the second adjustment gain. The 13th correlation data shows a relationship in which the larger the arm operation amount, the smaller the first adjustment gain. The 14th correlation data shows a relationship in which the higher the load pressure of the boom cylinder 6A, the smaller the second adjustment gain. The control unit 77 inputs the arm operation amount to the 13th correlation data and the load pressure of the boom cylinder 6A to the 14th correlation data. When the arm operation amount is input to the 13th correlation data, the first adjustment gain is output. When the load pressure of the boom cylinder 6A is input to the 14th correlation data, a second adjustment gain is output. The control unit 77 calculates the target flow rate of the hydraulic fluid supplied to the boom cylinder 6A by multiplying the larger of the first and second adjustment gains by the target flow rate calculated in step SA5 based on the target operating speed of the boom 4A.

[0149] If the high-load determination unit 75 determines in step SB3 that a high-load combined operation state is in effect, the control unit 77 outputs a control command to increase the flow rate of hydraulic fluid supplied to the arm cylinder 6B, which is a low-load actuator whose load pressure is below the pressure threshold. The control unit 77 outputs a control command to intervene and control the second control valve 17B so that the flow rate of hydraulic fluid supplied to the arm cylinder 6B, which is a low-load actuator, increases. In other words, the control unit 77 outputs a control command to increase the meter-in opening area of ​​the second control valve 17B.

[0150] If the high-load determination unit 75 determines in step SB3 that a high-load combined operation state is in effect, the control unit 77 outputs a control command to increase the flow rate of hydraulic fluid supplied to the arm cylinder 6B, based on the load pressure of the boom cylinder 6A, which is a high-load actuator whose load pressure is above the pressure threshold, and the amount of arm operation that operates the arm cylinder 6B, which is a low-load actuator. Specifically, the control unit 77 increases the flow rate of hydraulic fluid supplied to the arm cylinder 6B more the larger the amount of arm operation. That is, the control unit 77 increases the amount of increase in the flow rate of hydraulic fluid supplied to the arm cylinder 6B more the larger the target operating speed of the arm cylinder 6B. Furthermore, the control unit 77 increases the amount of increase in the flow rate of hydraulic fluid supplied to the arm cylinder 6B more the higher the load pressure of the boom cylinder 6A.

[0151] When the arm operation amount is large, the flow rate of hydraulic fluid to be supplied to the arm cylinder 6B is large, so the meter-in opening area of ​​the second control valve 17B is increased to increase the flow rate of hydraulic fluid supplied to the arm cylinder 6B. When the load pressure of the boom cylinder 6A is large, the meter-in opening area of ​​the second control valve 17B is increased to increase the flow rate of hydraulic fluid supplied to the arm cylinder 6B so that the operating speed of the arm cylinder 6B does not decrease.

[0152] Figure 19 is a diagram illustrating a method for calculating the target flow rate of hydraulic fluid supplied to the arm cylinder 6B when it is determined that a high-load combined operation state is in place according to the embodiment. The 15th correlation data, shown by line Lh in Figure 19, and the 16th correlation data, shown by line Li, are predetermined and stored in the correlation data storage unit 71. The 15th correlation data shows the relationship between the arm operation amount that operates the arm cylinder 6B, which is a low-load actuator, and the third adjustment gain. The 16th correlation data shows the relationship between the load pressure of the boom cylinder 6A, which is a high-load actuator, and the fourth adjustment gain. The 15th correlation data shows a relationship in which the larger the arm operation amount, the larger the third adjustment gain. The 16th correlation data shows a relationship in which the higher the load pressure of the boom cylinder 6A, the larger the fourth adjustment gain. The control unit 77 inputs the arm operation amount to the 15th correlation data and the load pressure of the boom cylinder 6A to the 16th correlation data. When the arm operation amount is input to the 15th correlation data, the third adjustment gain is output. When the load pressure of the boom cylinder 6A is input to the 16th correlation data, a fourth adjustment gain is output. The control unit 77 calculates the target flow rate of the hydraulic fluid supplied to the arm cylinder 6B by multiplying the smaller of the third adjustment gain and the fourth adjustment gain by the target flow rate calculated in step SA5 based on the target operating speed of the arm 4B.

[0153] If it is determined in step SB3 that the high-load combined operation state is not present (step SB3: No), the control valve 17 is controlled in step SA4 based on the target operating speed calculated based on multiple manipulated quantities and correlation data (step SB5).

[0154] It is determined whether or not a high-load combined operation state is in place. If it is determined that a high-load combined operation state is in place, i.e., the flow rate of hydraulic fluid supplied to the high-load actuator is reduced. As a result, when the work machine cylinder 6 reaches the stroke end and becomes a high-load actuator, and the hydraulic fluid supplied to the work machine cylinder 6 is relieved and discharged into the tank 16, the relief flow rate is suppressed, reducing hydraulic fluid loss and improving energy efficiency. In addition, a control command is output to increase the flow rate of hydraulic fluid supplied to the low-load actuator. This increases the flow rate of hydraulic fluid supplied to the low-load actuator, decreases the discharge pressure of the pump 15, increases the discharge volume of hydraulic fluid from the pump 15, and ultimately increases the flow rate of hydraulic fluid supplied to the low-load actuator. This increases the operating speed of the low-load actuator and improves work efficiency.

[0155] Furthermore, the same effect can be obtained not only when the work implement cylinder 6 reaches the end of its stroke, but also when the work implement cylinder 6 is difficult to move due to external resistance such as soil resistance, or when a large amount of energy is consumed to move the work implement cylinder 6.

[0156] [Control method when the slewing body is unable to rotate] Next, we will explain the control method for the work machine 1 when the slewing body 3 is unable to rotate, in a case where the operating device 8 is operated in combination so that the slewing motor 5 and the work machine cylinder 6 operate simultaneously. For example, due to contact between the slewing body 3 and an object, or contact between the work machine 4 and an object, a situation may arise in which the slewing body 3 is unable to rotate even though the operating device 8 is operated to allow the slewing body 3 to rotate.

[0157] In this embodiment, the state in which the slewing body 3 is unable to rotate means a state in which it cannot rotate at a rotation speed above a predetermined speed threshold. The speed threshold may be a value greater than zero. The state in which the slewing body 3 is unable to rotate includes a state in which the slewing body 3 cannot rotate at all, and a state in which a high load acts on the slewing body 3 and it rotates at a very slow rotation speed. An example of a state in which a high load acts on the slewing body 3 and it rotates at a very slow rotation speed is a groove digging operation in an oblique direction that involves rotation. From the start to the end of the groove digging operation, the slewing body 3 rotates at a very slow rotation speed with a small rotation angle.

[0158] The high-load determination unit 75 determines that the slewing body 3 is in a high-load combined operation state if it determines that the load pressure of the slewing motor 5 is equal to or greater than the pressure threshold, the amount of operation required to rotate the slewing body 3 is equal to or greater than the operation amount threshold, and the slewing speed of the slewing body 3 is less than the speed threshold, and that these conditions have persisted for a specified period of time. The pressure threshold, operation amount threshold, and speed threshold are predetermined values ​​and are stored in the threshold storage unit 73.

[0159] In other words, if the load pressure of the slewing motor 5 is above the pressure threshold, the amount of operation required to rotate the slewing body 3 is above the operation amount threshold, and the slewing speed of the slewing body 3 is below the speed threshold, and this condition persists for a specified time, the high-load determination unit 75 determines that a situation has occurred where the slewing body 3 cannot rotate despite the operation device 8 being operated to rotate the slewing body 3, and determines that the slewing body 3 is in a high-load combined operation state.

[0160] Furthermore, as described above, the high-load determination unit 75 determines that the work machine 4 is in a high-load combined operation state if the load pressure of the work machine cylinder 6 is equal to or greater than the pressure threshold.

[0161] The threshold change unit 79 changes the pressure threshold based on the rotation state of the slewing body 3. That is, the threshold change unit 79 changes the pressure threshold based on the detection data of the rotation sensor 30. When the slewing body 3 is stopped and the work implement 4 is operating, the threshold change unit 79 sets the pressure threshold for the work implement cylinder 6 to a first value, and when the slewing body 3 is rotating and the work implement 4 is operating, it sets the pressure threshold for the work implement cylinder 6 to a second value which is smaller than the first value.

[0162] When the working implement 4 is operating while the slewing body 3 is stopped, the working implement 4 may be performing heavy-load operations such as excavation. When the working implement 4 is performing heavy-load operations, if the pressure threshold is set to a low value, it may be determined that a high-load combined operation state is occurring even though the working implement cylinder 6 has not reached the stroke end (even though the working implement cylinder 6 is performing normal operations), and the control valve 17 may intervene to reduce the flow rate of hydraulic fluid supplied to the working implement cylinder 6. As a result, work efficiency may decrease. Therefore, when the working implement 4 is operating while the slewing body 3 is stopped, the pressure threshold for the working implement cylinder 6 is set to a high first value.

[0163] When the working implement 4 is operating while the slewing body 3 is slewing, the working implement 4 may simply be moving in the air without performing any work. When the working implement 4 is moving in the air, it is preferable to set the pressure threshold to a low value so that when the working implement cylinder 6 reaches the end of its stroke, it is immediately determined that the working implement cylinder 6 is in a high-load combined operation state. That is, when the working implement 4 is moving in the air and the working implement cylinder 6 reaches the end of its stroke, it is preferable that the amount of hydraulic fluid supplied to the working implement cylinder 6 is immediately reduced and the amount of hydraulic fluid supplied to the slewing motor 5 is increased. By increasing the amount of hydraulic fluid supplied to the slewing motor 5, the decrease in the slewing speed of the slewing body 3 is suppressed, and thus the decrease in work efficiency is suppressed. For this reason, when the working implement 4 is operating while the slewing body 3 is slewing, the pressure threshold for the working implement cylinder 6 is set to a low second value.

[0164] As mentioned above, this applies not only when the work implement cylinder 6 reaches the end of its stroke, but also when the work implement cylinder 6 is difficult to move due to external resistance such as soil resistance, or when a large amount of energy is consumed to move the work implement cylinder 6.

[0165] The lower second value may be set to detect when the stroke end is reached, or, by setting the pressure value during the pressure rise before reaching the stroke end, intervention control can be started with a margin, thereby preventing a decrease in the operating speed of the swing motor 5 and other actuators when the stroke end is reached.

[0166] Figure 20 is a flowchart showing the control method for the work machine 1 according to the embodiment. The high load determination unit 75 acquires the load pressure of the work machine cylinder 6 and the load pressure of the swing motor 5. That is, the high load determination unit 75 acquires the detection data of the load pressure sensor 18 (step SC1).

[0167] The manipulated amount acquisition unit 74 acquires multiple manipulated amounts of the operating device 8, which is operated in a combined manner so that multiple actuators operate simultaneously (step SC2).

[0168] The high-load determination unit 75 acquires the rotation state of the rotating body 3. That is, the high-load determination unit 75 acquires detection data from the rotation sensor 30 (step SC3). Based on the detection data from the rotation sensor 30, the high-load determination unit 75 determines whether or not the rotating body 3 is rotating. Alternatively, the high-load determination unit 75 may determine whether or not the rotating body 3 is rotating based on the rotation operation amount acquired by the operation amount acquisition unit 74 (step SC4).

[0169] In step SC4, if it is determined that the slewing body 3 is not slewing (step SC4: No), the threshold value change unit 79 sets the pressure threshold related to the load pressure of the work machine cylinder 6 to a first value (step SC5). In step SC4, if it is determined that the slewing body 3 is slewing (step SC4: Yes), the threshold value change unit 79 sets the pressure threshold related to the load pressure of the work machine cylinder 6 to a second value which is smaller than the first value (step SC6).

[0170] The high-load determination unit 75 determines whether the slewing body 3 is in a high-load combined operation state. That is, the high-load determination unit 75 determines whether the load pressure of the slewing motor 5 is above a pressure threshold, the amount of slewing operation to rotate the slewing body 3 is above an operation amount threshold, and the slewing speed of the slewing body 3 is below a speed threshold, and whether this state has continued for a specified time (step SC7).

[0171] In step SC7, if it is determined that the slewing body 3 is in a high-load combined operation state (step SC7: Yes), the control unit 77 intervenes to control the fourth control valve 17D, which controls the flow rate of hydraulic fluid supplied to the slewing motor 5. The control unit 77 outputs a control command to intervene and control the fourth control valve 17D so that the flow rate of hydraulic fluid supplied to the slewing motor 5 decreases. That is, the control unit 77 outputs a control command so that the meter-in opening area of ​​the fourth control valve 17D becomes smaller (step SC9).

[0172] In step SC7, if it is determined that the slewing body 3 is not in a high-load combined operation state (step SC7: No), the high-load determination unit 75 determines whether or not the work implement 4 is in a high-load combined operation state. That is, the high-load determination unit 75 determines whether or not the load pressure of the work implement cylinder 6 is above a pressure threshold (step SC8).

[0173] In step SC8, if it is determined that the work machine cylinder 6 is in a high-load combined operation state (step SC8: Yes), the control unit 77 intervenes to control the control valve 17 that controls the flow rate of hydraulic fluid supplied to the work machine cylinder 6. For example, if it is determined that the boom cylinder 6A is in a high-load combined operation state, the control unit 77 outputs a control command to intervene and control the first control valve 17A so that the flow rate of hydraulic fluid supplied to the boom cylinder 6A decreases. That is, the control unit 77 outputs a control command so that the meter-in opening area of ​​the first control valve 17A becomes smaller (step SC9).

[0174] If it is determined in step SC8 that the high-load combined operation state is not present (step SC8: No), the control valve 17 is controlled based on multiple manipulated quantities and correlated data (step SC10).

[0175] When the slewing body 3 is not slewing, the pressure threshold related to the load pressure of the work machine cylinder 6 is set to a high first value, and when the slewing body 3 is slewing, the pressure threshold related to the load pressure of the work machine cylinder 6 is set to a low second value.

[0176] When the working implement 4 is operating while the slewing body 3 is stopped, the working implement 4 may be performing heavy-load operations such as excavation. When the working implement 4 is performing heavy-load operations, if the pressure threshold is set to a low value, it may be determined that a high-load combined operation state is occurring even though the working implement cylinder 6 has not reached the stroke end (even though the working implement cylinder 6 is performing normal operations), and the control valve 17 may intervene to reduce the flow rate of hydraulic fluid supplied to the working implement cylinder 6. As a result, work efficiency may decrease. When the working implement 4 is operating while the slewing body 3 is stopped, the pressure threshold for the working implement cylinder 6 is set to a high first value, so the decrease in work efficiency is suppressed.

[0177] When the working implement 4 is operating while the slewing body 3 is slewing, the working implement 4 may simply be moving in the air without performing any work. When the working implement 4 is moving in the air, it is preferable to set the pressure threshold to a low value so that when the working implement cylinder 6 reaches the end of its stroke, it is immediately determined that the working implement cylinder 6 is in a high-load combined operation state. That is, when the working implement 4 is moving in the air, it is preferable that when the working implement cylinder 6 reaches the end of its stroke, the amount of hydraulic fluid supplied to the working implement cylinder 6 is immediately reduced and the amount of hydraulic fluid supplied to the slewing motor 5 is increased. By increasing the amount of hydraulic fluid supplied to the slewing motor 5, the decrease in the slewing speed of the slewing body 3 is suppressed, and thus the decrease in work efficiency is suppressed. When the working implement 4 is operating while the slewing body 3 is slewing, the pressure threshold for the working implement cylinder 6 is set to a low second value, so the decrease in work efficiency is suppressed.

[0178] As mentioned above, this applies not only when the work implement cylinder 6 reaches the end of its stroke, but also when the work implement cylinder 6 is difficult to move due to external resistance such as soil resistance, or when a large amount of energy is consumed to move the work implement cylinder 6.

[0179] [Other Embodiments] Figure 21 is a schematic diagram showing a part of the control system 13 of the work machine 1 according to an embodiment. Similar to the control system 13 shown in Figure 16, in the control system 13 shown in Figure 21, the hydraulic fluid discharged from the pump 15 is distributed to the boom cylinder 6A and the arm cylinder 6B. In the example shown in Figure 21, a discharge pressure sensor 31 is provided to detect the pressure of the hydraulic fluid discharged from the pump 15. The first load pressure sensor 18A and the discharge pressure sensor 31 detect the differential pressure ΔPa across the first control valve 17A. The second load pressure sensor 18B and the discharge pressure sensor 31 detect the differential pressure ΔPb across the second control valve 17B. The first load pressure sensor 18A and the discharge pressure sensor 31 function as pressure sensors to detect the differential pressure ΔPa across the first control valve 17A. The second load pressure sensor 18B and the discharge pressure sensor 31 function as pressure sensors to detect the differential pressure ΔPb across the second control valve 17B. The calculation unit 76 calculates the target flow rate of hydraulic fluid supplied to the work machine cylinders 6 (6A, 6B) based on the target operating speed of the work machine cylinders 6 (6A, 6B). The control unit 77 controls the multiple control valves 17 (17A, 17B) such that the ratio of the product of the opening area of ​​each meter-in opening of each control valve 17 (17A, 17B) and the square root of the differential pressure ΔP (ΔPa, ΔPb) across the meter-in opening becomes the ratio of the target flow rate of hydraulic fluid supplied to each of the work machine cylinders 6 (6A, 6B).

[0180] Figure 22 is a schematic diagram showing a part of the control system 13 of the work machine 1 according to an embodiment. Similar to the control system 13 shown in Figure 16, in the control system 13 shown in Figure 22, the hydraulic fluid discharged from the pump 15 is distributed to the boom cylinder 6A and the arm cylinder 6B. In the example shown in Figure 22, pressure compensation valves 32 (32A, 32B) are provided to compensate for the pressure of the hydraulic fluid supplied from a plurality of control valves 17 (17A, 17B) to the work machine cylinders 6 (6A, 6B). Pressure compensation valve 32A is positioned between the boom cylinder 6A and the first control valve 17A. Pressure compensation valve 32B is positioned between the arm cylinder 6B and the second control valve 17B. Check valves 33 (33A, 33B) are positioned between the pressure compensation valve 32 and the control valve 17. Check valve 33A prevents hydraulic fluid from flowing from the pressure compensation valve 32A to the first control valve 17A. The check valve 33B prevents hydraulic fluid from flowing from the pressure compensation valve 32B to the second control valve 17B. A shuttle valve 34 is positioned between the pressure compensation valve 32A and the pressure compensation valve 32B. The calculation unit 76 calculates the target flow rate of hydraulic fluid supplied to the work machine cylinders 6 (6A, 6B) based on the target operating speed of the work machine cylinders 6 (6A, 6B). The control unit 77 controls the multiple control valves 17 (17A, 17B) so that the ratio of the opening areas of the meter-in openings of the multiple control valves 17 (17A, 17B) matches the ratio of the target flow rate of hydraulic fluid supplied to the work machine cylinders 6 (6A, 6B).

[0181] Figure 23 is a schematic diagram showing a part of the control system 13 of the work machine 1 according to an embodiment. In the control system 13 shown in Figure 23, the same number of pumps 15 are provided as the number of actuators. One pump 15 is connected to each of the multiple actuators. In the example shown in Figure 23, the pumps 15 include a pump 15A connected to the boom cylinder 6A and a pump 15B connected to the arm cylinder 6B. The calculation unit 76 calculates the target flow rate of hydraulic fluid supplied to the work machine cylinders 6 (6A, 6B) based on the target operating speed of the work machine cylinders 6 (6A, 6B). The control unit 77 controls the discharge flow rate of hydraulic fluid discharged from the multiple pumps 15 (15A, 15B) so that the actual flow rate of hydraulic fluid supplied to the multiple work machine cylinders 6 (6A, 6B) becomes the respective target flow rate. On the other hand, if the dischargeable flow rate of at least one pump 15 is insufficient for the target flow rate of the connected actuator due to the hardware characteristics (pump capacity) of the pumps, the discharge flow rates of the hydraulic fluid discharged from the multiple pumps 15 (15A, 15B) are controlled so that the ratio of the actual flow rates of the hydraulic fluid supplied to the multiple work machine cylinders 6 (6A, 6B) becomes the ratio of the target flow rates.

[0182] 1...Working machine, 2...Traction unit, 2A...Track, 3...Slewing unit, 4...Working machine, 4A...Boom, 4B...Arm, 4C...Bucket, 5...Slewing motor, 6...Working machine cylinder, 6A...Boom cylinder, 6B...Arm cylinder, 6C...Bucket cylinder, 7...Controller, 8...Operating device, 8A...Left working lever, 8B...Right working lever, 8C...Left travel lever, 8D...Right travel lever, 8E...Left foot pedal, 8F...Right foot pedal, 9...Monitor, 9A...Display device, 9B...Input device 10...Cab, 11...Driver's seat, 12...Computer, 12A...Processor, 12B...Main memory, 12C...Storage, 12D...Input / Output interface, 12E...Communication interface, 12F...Computer program, 13...Control system, 14...Power source, 15...Pump, 15A...Pump, 15B...Pump, 16...Tank, 17...Control valve, 17A...First control valve, 17B...Second control valve, 17C...Third control valve, 17D...Fourth control valve, 18...Load pressure sensor, 18A...First load pressure sensor, 18B...Second load pressure sensor, 18C...Third load pressure sensor, 18D...Fourth load pressure sensor, 19...Pump passage, 20...Suction passage, 21...Bottom passage, 21A...First bottom passage, 21B...Second bottom passage, 21C...Third bottom passage, 21D...First motor passage, 22...Head passage, 22A...First head passage, 22B...Second head passage, 22C...Third head passage, 22D...Second motor passage, 30...Swivel sensor, 31...Discharge pressure sensor, 32...Pressure compensation Valve, 32A...pressure compensation valve, 32B...pressure compensation valve, 33...check valve, 33A...check valve, 33B...check valve, 34...shuttle valve, 71...correlation data storage unit, 72...priority storage unit, 73...threshold storage unit, 74...operation variable acquisition unit, 75...high load determination unit, 76...calculation unit, 77...control unit, 78...correlation data modification unit, 79...threshold modification unit, 90...external device, La...line, Lb...line, Lc...line, Ld...line, Le...line, Ra1...point, Ra2...point, Rb1...point, Rb2...point.

Claims

1. A control system for a work machine comprising: a plurality of actuators; a controller that receives a plurality of operation commands for operating the plurality of actuators and controls at least one of the plurality of actuators, wherein the controller acquires the plurality of operation commands for operating one of the actuators and calculates an operation command for one of the actuators based on the relationship between the plurality of operation commands and the operation commands of one of the actuators corresponding to the plurality of operation commands.

2. The actuator includes a first actuator, a second actuator, and a third actuator, and the relationship includes first correlation data showing the relationship between an operation command for the first actuator, an operation command for the second actuator, and an operation command for the first actuator, and second correlation data showing the relationship between an operation command for the first actuator, an operation command for the third actuator, and an operation command for the first actuator, and the controller obtains the priority of the first correlation data and the second correlation data, and when it obtains a plurality of operation commands to operate at least two actuators, including the first actuator, simultaneously, it calculates an operation command for the first actuator based on the plurality of operation commands and the correlation data adjusted based on the priority, the control system for a work machine according to claim 1.

3. The control system for a work machine according to claim 2, wherein the first correlation data is assigned a higher priority than the second correlation data, and the controller, when it receives a plurality of operation commands to operate the first actuator and the second actuator simultaneously, calculates an operation command for the first actuator based on the plurality of operation commands and the first correlation data, regardless of the content of the operation command for the third actuator, and when it receives a plurality of operation commands to operate the first actuator and the third actuator simultaneously and not operate the second actuator, calculates an operation command for the first actuator based on the plurality of operation commands and the second correlation data.

4. A control system for a work machine according to claim 2, wherein the first correlation data is assigned a higher priority than the second correlation data, and the controller modifies the first correlation data based on the operation command for the third actuator and the second correlation data if the operation command for the second actuator is within a specified range that includes an operation command value that does not operate the second actuator, calculates an operation command for the first actuator based on the multiple operation commands and the modified first correlation data, and calculates an operation command for the first actuator based on the multiple operation commands and the first correlation data if the operation command for the second actuator is outside the specified range.

5. The relationship is correlation data indicating the relationship between an operation command for the first actuator, an operation command for the second actuator, and an operation command for the first actuator, and the control system for a work machine according to claim 2, comprising an input device for changing the correlation data, wherein the controller changes the correlation data based on input data from the input device.

6. The control system for a work machine according to claim 1, wherein the controller controls the operating speed of the actuator based on the operation command.

7. The control system for a work machine according to claim 6, wherein the operation command is a target operating speed of the actuator, and the controller outputs a control command such that the ratio of the actual operating speeds of the plurality of actuators is the ratio of the target operating speeds.

8. A control system for a work machine according to claim 7, wherein a portion of the plurality of actuators is a plurality of hydraulic actuators driven by hydraulic fluid, and comprises the same number of pumps as the hydraulic actuators for discharging the hydraulic fluid supplied to the hydraulic actuators, one pump connected to each of the plurality of hydraulic actuators, and the controller calculates a target flow rate of hydraulic fluid supplied to the hydraulic actuators based on the target operating speed, and controls the discharge flow rate of hydraulic fluid discharged from the plurality of pumps so that the ratio of the flow rates of hydraulic fluid supplied to the plurality of hydraulic actuators is the ratio of the target flow rate.

9. A control system for a work machine according to claim 7, wherein a portion of the plurality of actuators is a plurality of hydraulic actuators driven by hydraulic fluid, comprising: a pump for discharging the hydraulic fluid supplied to the hydraulic actuators; a plurality of control valves including meter-in openings for controlling the flow rate of the hydraulic fluid supplied from the pump to each of the plurality of hydraulic actuators; and a pressure compensation valve for compensating the pressure of the hydraulic fluid supplied from the control valves to each of the hydraulic actuators, wherein the controller calculates a target flow rate of the hydraulic fluid supplied to the hydraulic actuators based on the target operating speed, and controls the plurality of control valves such that the ratio of the opening areas of the meter-in openings of the plurality of control valves matches the ratio of the target flow rate.

10. A control system for a work machine according to claim 7, wherein a portion of the plurality of actuators is a plurality of hydraulic actuators driven by hydraulic fluid, comprising: a pump for discharging the hydraulic fluid supplied to the hydraulic actuators; a plurality of control valves including meter-in openings for controlling the flow rate of the hydraulic fluid supplied from the pump to each of the plurality of hydraulic actuators; and a pressure sensor for detecting the differential pressure across each of the meter-in openings of the plurality of control valves, wherein the controller calculates a target flow rate of hydraulic fluid supplied to the hydraulic actuators based on the target operating speed, and controls the plurality of control valves such that the ratio of the product of the opening area of ​​each of the plurality of meter-in openings and the square root of the differential pressure across the meter-in openings matches the ratio of the target flow rate.

11. A control system for a work machine comprising: a plurality of actuators; and a controller that receives a plurality of operation commands for operating the plurality of actuators and controls at least one of the plurality of actuators, wherein the controller, when it has received a plurality of operation commands so that the plurality of actuators operate simultaneously and at least one of the actuators is in a high-load state, outputs a control command to reduce the operating speed of the high-load actuator indicating the high-load actuator.

12. A control system for a work machine according to claim 11, comprising a pressure sensor for detecting the load of the actuator, wherein the controller determines whether or not a high load state is present based on the detection data of the pressure sensor.

13. The control system for a work machine according to claim 11, wherein the actuator includes a slewing motor for slewing a slewing body and a work machine cylinder for operating a work machine, and the controller changes the determination of a high load state based on the slewing state of the slewing body.

14. The control system for a work machine according to claim 13, wherein the controller determines the high load state based on a load threshold for the load, sets the load threshold for the work machine cylinder to a first value when the work machine is operating while the slewing body is stopped, and sets the load threshold for the work machine cylinder to a second value smaller than the first value when the work machine is operating while the slewing body is rotating.

15. The control system for a work machine according to claim 11, wherein the actuator includes a slewing motor for slewing a slewing body and a work machine cylinder for operating a work machine, and is equipped with a speed sensor for detecting the slewing speed of the slewing body, and the controller determines the high load state based on a load threshold for the load, determines that it is a high load combined operation state if the load of the work machine cylinder is equal to or greater than the load threshold, and determines that it is a high load state if the load of the slewing motor is equal to or greater than the load threshold, the target slewing speed of the slewing body corresponding to the operation command for slewing the slewing body is equal to or greater than the target speed threshold, and the state in which the slewing speed of the slewing body detected by the speed sensor is less than the speed threshold continues for a specified time.

16. The control system for a work machine according to claim 11, wherein the controller determines the high load state based on a load threshold for the load, and when it has received multiple operation commands so that multiple actuators operate simultaneously and at least one actuator is in a high load state, it outputs a control command to reduce the operating speed of the high load actuator based on the load of the high load actuator and an operation command to operate a low load actuator indicating an actuator whose load is less than the load threshold.

17. The control system for a work machine according to claim 16, wherein the controller increases the amount of reduction in the operating speed of the high-load actuator as the target operating speed of the low-load actuator corresponding to the operation command for operating the low-load actuator increases, or increases the amount of reduction in the operating speed of the high-load actuator as the load on the high-load actuator increases.

18. A control system for a work machine comprising: a plurality of actuators; a load pressure sensor for detecting the load pressure of the actuators; and a controller for receiving a plurality of operation commands for operating the plurality of actuators and controlling at least one of the plurality of actuators, wherein the controller, when it has received a plurality of operation commands for the plurality of actuators to operate simultaneously and at least one of the actuators is in a high-load state, outputs a control command to increase the flow rate of hydraulic fluid supplied to a low-load actuator that is not in a high-load state.

19. The control system for a work machine according to claim 18, wherein the controller determines the high load state based on a pressure threshold for load pressure, and when it has received multiple operation commands so that multiple actuators operate simultaneously, and at least one actuator is in a high load state, it outputs a control command to increase the flow rate of hydraulic fluid supplied to the low load actuator based on the load pressure of the high load actuator, which indicates the actuator whose load pressure is equal to or greater than the pressure threshold, and an operation command to operate the low load actuator.

20. The control system for a work machine according to claim 19, wherein the controller increases the amount of increase in the flow rate of the hydraulic fluid supplied to the low-load actuator as the target operating speed of the low-load actuator corresponding to the operation command for operating the low-load actuator increases, or increases the amount of increase in the flow rate of the hydraulic fluid supplied to the low-load actuator as the load pressure of the high-load actuator increases.

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