Work machine

Abstract

The work machine is provided with a plurality of hydraulic actuators that drive a work implement, and a controller that outputs control signals for controlling the hydraulic actuators based on speed commands for the actuators calculated at each calculation cycle. The controller is configured to calculate a speed command for a first hydraulic actuator at a current calculation cycle using an actual speed of the first hydraulic actuator at the current calculation cycle calculated based on a detection signal from a posture detection device, and a past history of speed commands for the first hydraulic actuator calculated at past calculation cycles compared with the current calculation cycle, in a case where the operation of the first hydraulic actuator is controlled based on the operation of a second hydraulic actuator under predetermined conditions, and output the control signal for the first hydraulic actuator based on the speed command for the first hydraulic actuator at the current calculation cycle.

Description

TECHNICAL FIELD

[0001] The present application relates to a work machine provided with a work device, and more particularly to a work machine that controls the operation of the work device under prescribed conditions. BACKGROUND

[0002] A work machine is provided with a work device that is driven by a hydraulic actuator. As a technique for improving the work efficiency of a work machine, there is a technique called Machine Control (MC). MC is a technique for assisting the operation of an operator by performing semi-automatic control that causes the work device to operate in accordance with predetermined conditions in a case where the operator has operated an operation device. In MC, for example, control is performed that causes the work device to operate along a predetermined reference surface. In this case, stable operation of the hydraulic actuator at the same speed as the target speed is sought. For example, when horizontal excavation is performed by MC in a hydraulic excavator that is provided with a multi-joint front work device that has a boom and a stick and the like coupled thereto, horizontal excavation is generally performed by a compound operation of stick retraction and boom raising, and therefore in order to move the front work device along the excavation target surface (reference surface), high-precision control of the speed of each hydraulic actuator that drives the stick and the boom is required.

[0003] For example, in Patent Literature 1, a technique is disclosed that prevents a delay in the response of MC (for example, an instruction for boom raising) with respect to the actual operation of a hydraulic actuator (for example, a stick hydraulic cylinder) that drives a work device, and aims at the stabilization of the behavior of the work device in MC. In the hydraulic excavator described in Patent Literature 1, in a case where a prescribed time or more has elapsed after the operation for the stick has started, the control device performs MC based on the stick hydraulic cylinder speed calculated from the detection value of a posture detection device; on the other hand, in a case where the operation for the stick has just started (the stick starts to operate), the control device performs MC based on the stick hydraulic cylinder speed calculated from the operation amount of the operation device. The speed calculated from the detection value of the posture detection device is generally closer to the actual speed than the speed calculated from the operation amount of the operation device. However, since the posture detection device cannot detect a change in posture if the work device is not actually operating, the response of MC is delayed with respect to the start of operation of the stick when MC is performed based on the detection value of the posture detection device. Therefore, MC is performed based on the stick hydraulic cylinder speed calculated from the operation amount of the operation device only in a case where the stick starts to operate.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: International Publication No. 2019 / 053814 SUMMARY

[0007] As described above, in the MC, it is required to control the speed of the hydraulic actuator with high precision. However, there is a problem that the actual speed of the hydraulic actuator is delayed in response to the speed command of the control device for driving the hydraulic actuator. This is because there are many processes from when the control signal of the control device is output to when the hydraulic actuator is actually driven at the speed corresponding to the speed command of the control device. For example, the pump displacement of the hydraulic pump is changed in accordance with the speed command for the hydraulic actuator, and the flow rate control valve corresponding to the hydraulic actuator is driven in accordance with the speed command. Also, the hydraulic oil discharged from the hydraulic pump after the pump displacement is changed is supplied to the hydraulic actuator via the driven flow rate control valve, the pressure in the hydraulic actuator rises, and thus the speed of the hydraulic actuator changes.

[0008] In the technology described in Patent Document 1, there is no countermeasure for the problem of the delay in response of the actual speed of the hydraulic actuator to the speed command, except for the situation where the hydraulic actuator starts to operate. That is, when the speed command of the other hydraulic actuator as a control target is calculated based on the speed of a certain hydraulic actuator calculated from the detection value of the posture detection device (MC is performed), at the point in time when the actual speed of the other hydraulic actuator as a control target becomes the speed command, the speed of the certain hydraulic actuator has already changed to a value different from the speed that becomes the basis for calculation of the speed command. In the MC, since it is sought to make the hydraulic actuator always operate at the same speed as the target speed, it is desirable that the delay in response of the actual speed of the hydraulic actuator to the speed command be addressed throughout the entire range from the start of operation of the hydraulic actuator to the end of operation.

[0009] In addition, in the technology described in Patent Document 1, when the hydraulic actuator starts to operate, the MC is performed based on the speed calculated from the operation amount of the operation device. However, the speed calculated from the operation amount of the operation device can have a large deviation from the actual speed of the hydraulic actuator. When the MC is performed based on such a speed, the operation accuracy of the front work device can deteriorate.

[0010] The present application has been achieved based on the above-described circumstances, and aims to provide a work machine capable of reducing the influence of the delay in response of the actual speed of the hydraulic actuator to the speed command and improving the operation accuracy of the work device in the MC.

[0011] The present application includes a plurality of solutions to the above problems, and if one example is cited, it is characterized by having: a work device that performs work; a plurality of hydraulic actuators that drive the work device; a hydraulic pump that supplies hydraulic oil to the plurality of hydraulic actuators; a plurality of control valves that respectively control the flow of hydraulic oil supplied from the hydraulic pump to each of the plurality of hydraulic actuators; a posture detection device that detects the posture of the work device; and a controller that calculates the speed command of each of the plurality of actuators at an operation cycle, and outputs a control signal for controlling each of the plurality of hydraulic actuators based on the speed command of each of the plurality of hydraulic actuators as a result of the calculation, the controller being configured to, in the case of controlling the operation of a first hydraulic actuator under a predetermined condition according to the operation of a second hydraulic actuator among the plurality of hydraulic actuators, calculate the actual speed of each of the plurality of hydraulic actuators at the current operation cycle based on a detection signal of the posture detection device, calculate the speed command of the first hydraulic actuator at the current operation cycle that satisfies the condition using the actual speed of each of the plurality of hydraulic actuators as a result of the calculation, and a past history of the speed command of each of the plurality of hydraulic actuators calculated at an operation cycle in the past compared to the current operation cycle, and output a control signal for controlling the first hydraulic actuator based on the speed command of the first hydraulic actuator at the current operation cycle as a result of the calculation.

[0012] Effects of the Invention

[0013] According to the present application, since the speed command of the first hydraulic actuator at the current operation cycle that satisfies the prescribed condition is calculated using the actual speed of each hydraulic actuator at the current operation cycle calculated based on the detection signal of the posture detection device, and the past history of the speed command of each hydraulic actuator calculated at an operation cycle in the past compared to the current operation cycle, the speed command of the first hydraulic actuator that takes into account the response delay of the actual speed with respect to the speed command can be calculated. Therefore, the influence of the response delay of the actual speed of the hydraulic actuator with respect to the speed command can be reduced, and the operation accuracy of the work device in the MC can be improved.

[0014] The above problems, structures, and effects other than the above can be made clear through the following embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a perspective view of a hydraulic excavator that represents the first embodiment of a work machine to which the present application is applied.

[0016] Figure 2 is a hydraulic circuit diagram that represents a hydraulic system mounted in the first embodiment of the work machine of the present application.

[0017] Figure 3 is a block diagram showing hardware and functions of a controller that constitutes a part of the work machine of the first embodiment of the present application.

[0018] Figure 4 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 3

[0019] Figure 5 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 4

[0020] Figure 6 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 4

[0021] Figure 7 is a block diagram showing functions of an MC arithmetic unit of the controller shown in

[0022] Figure 8 is a block diagram showing functions of an MC arithmetic unit of the controller that constitutes a part of the work machine of the second embodiment of the present application.

[0023] Figure 9 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 8

[0024] Figure 10 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 8

[0025] Figure 11 is a block diagram showing functions of an MC arithmetic unit of the controller shown in

[0026] Figure 12 is a block diagram showing functions of an MC arithmetic unit of the controller that constitutes a part of the work machine of the third embodiment of the present application.

[0027] Figure 13 is a block diagram showing functions of an MC arithmetic unit of the controller shown in Figure 12

[0028] Figure 14 is a block diagram showing functions of an MC arithmetic unit of the controller shown in​​​​​​Figure 12 A flowchart illustrating an example of the processing steps in the hydraulic pump control unit of the controller shown.

[0029] Figure 15 This is an explanatory diagram showing the relationship between the pilot pressure information of the control valve and the pump volume information of the hydraulic pump relative to the speed information of the hydraulic actuator when executing MC in the third embodiment of the working machine of the present invention. Detailed Implementation

[0030] Hereinafter, embodiments of the working machine of the present invention will be described using the accompanying drawings. In this embodiment, a hydraulic excavator will be described as an example of the working machine. In addition, in this specification, the words "upper," "above," or "below" used with terms indicating a shape (e.g., the excavation target surface) mean that "upper" refers to the "surface" of the shape, "above" refers to the "position higher than the surface" of the shape, and "below" refers to the "position lower than the surface" of the shape.

[0031] [First Implementation Method]

[0032] First, use Figure 1 The structure of a hydraulic excavator according to a first embodiment of the working machinery of the present invention will be described. Figure 1 This is a perspective view of a hydraulic excavator according to a first embodiment of the working machinery to which the present invention is applied. Here, the description is given from the perspective of the operator seated in the driver's seat.

[0033] exist Figure 1 In this example, the hydraulic excavator, as a working machine, has a front working device 1 for performing excavation and other operations, and a body 2 on which the front working device 1 is rotatably mounted. The body 2 consists of a self-propelled lower traveling body 3 and an upper rotating body 4 rotatably mounted on the lower traveling body 3.

[0034] The front working device 1 is a multi-joint type working device constructed by connecting multiple driven components in a manner that allows them to rotate in the vertical direction. The multiple driven components include, for example, a boom 11, a stick 12, and a bucket 13 as a working tool. The base end of the boom 11 is rotatably supported on the front of the upper rotating body 4 by means of a boom pin (not shown). The base end of the stick 12 is rotatably supported on the front end of the boom 11 by means of a stick pin (not shown). The bucket 13 is rotatably supported on the front end of the stick 12 by means of a bucket pin 13a. The boom 11, stick 12, and bucket 13 are driven by a boom hydraulic cylinder 15, a stick hydraulic cylinder 16, and a bucket hydraulic cylinder 17, respectively, which are hydraulic actuators. The bucket 13 is driven via a linkage member 18 that rotates in conjunction with the bucket 13.

[0035] The lower traveling body 3 is provided with, for example, crawler-type traveling devices 21 (only the left one is shown) on the left and right sides. The traveling device 21 is driven by a traveling hydraulic motor 21a as a hydraulic actuator.

[0036] The upper rotating body 4 is, for example, configured to be rotationally driven with respect to the lower traveling body 3 by a rotating hydraulic motor 6 as a hydraulic actuator. The upper rotating body 4 includes a cab 23 in which an operator rides and a machine room 24 in which various devices are accommodated.

[0037] In the cab 23, operation devices 25, 26 (see also the description of Figure 2 ) for operating the respective hydraulic actuators 6, 15 to 17, 21a are arranged. The operation device 25 has operation levers 25a, 25b that can be tilted forward and backward and left and right. The forward and backward direction operation and the left and right direction operation of the operation levers 25a, 25b are respectively assigned to the operations of different hydraulic actuators. For example, each operation of the operation levers 25a, 25b is assigned to the operation of the front working device 1 (boom hydraulic cylinder 15, arm hydraulic cylinder 16, bucket hydraulic cylinder 17), the rotation operation of the upper rotating body 4 (rotating hydraulic motor 6), and the like. The operation device 26 has left and right traveling pedals 26a, 26b and left and right traveling levers 26c, 26d that can be tilted forward and backward and are linked to the operations of the traveling pedals 26a, 26b. The left and right traveling pedals 26a, 26b and the traveling levers 26c, 26d are assigned to the traveling operations of the left and right traveling devices 21 (traveling hydraulic motors 21a). Details of the operation devices will be described later. In addition, in the cab 23, a display device 27 (see also the description of Figure 3 ) for displaying various information and setting screens related to the hydraulic excavator and the like is arranged.

[0038] In the machine room 24, a prime mover 41, a hydraulic pump 42, and a pilot pump 43 (see also the description of Figure 2 ) and the like are arranged. In addition, a control valve unit 44, which is a collection of a plurality of control valves including a flow control valve (see also the description of Figure 2 ) to be described later, is arranged.

[0039] On the boom 11, a boom angle sensor 31 that detects a physical quantity (attitude information) related to the attitude of the boom 11 is provided. The boom angle sensor 31 is, for example, a rotary potentiometer mounted on a boom pin that is a linking portion of the boom 11 and the upper rotating body 4, and detects a relative rotation angle (boom angle) of the boom 11 with respect to the upper rotating body 4.

[0040] A stick angle sensor 32 is provided on the stick 12 to detect physical quantities (posture information) related to the posture of the stick 12. The stick angle sensor 32 is, for example, a rotary potentiometer mounted on the stick pin, which is the connection part between the boom 11 and the stick 12, and detects the relative rotation angle (stick angle) of the stick 12 relative to the boom 11.

[0041] A bucket angle sensor 33 is provided on the bucket 13 to detect physical quantities (posture information) related to the posture of the bucket 13. The bucket angle sensor 33 is, for example, a rotary potentiometer mounted on the connecting rod assembly 18, which detects the relative rotation angle (bucket angle) of the bucket 13 relative to the stick 12.

[0042] A tilt angle sensor 34 is installed on the upper rotating body 4 to detect physical quantities (attitude information) related to the posture of the body 2. The tilt angle sensor 34 detects the tilt angle (body angle) of the upper rotating body 4 (body 2) relative to a reference plane (e.g., a horizontal plane).

[0043] The boom angle sensor 31, stick angle sensor 32, bucket angle sensor 33, and body tilt angle sensor 34 constitute a posture detection device 30 that detects physical quantities (posture information) related to the posture of the front working device 1. The controller 80 (described later) of each sensor 31-34 of the posture detection device 30 is also described later. Figure 3 The output device 1 outputs the detected values ​​(detection signals) of the posture information (boom angle, stick angle, bucket angle, and body angle) of the front working device 1. It should be noted that the angle sensors 31 to 33 can be replaced with tilt angle sensors, inertial measurement units (IMUs), or stroke sensors that can be installed on each hydraulic cylinder 15 to 17.

[0044] Next, use Figure 2 The structure of the hydraulic system in the first embodiment of the working machine of the present invention will be described. Figure 2 This is a hydraulic circuit diagram showing the hydraulic system in the first embodiment of the working machinery of the present invention.

[0045] exist Figure 2 In this context, the hydraulic excavator is equipped with a front working device 1, a lower traveling body 3, and an upper rotating body 4 driven by hydraulic pressure (see also...). Figure 1 The hydraulic system 40. It should be noted that, in Figure 2 Only the hydraulic circuits related to the hydraulic actuators driving the front working device 1, namely the boom hydraulic cylinder 15, stick hydraulic cylinder 16, and bucket hydraulic cylinder 17, are shown. The hydraulic circuits related to the travel hydraulic motor 21a driving the travel device 21 and the rotary hydraulic motor 6 driving the upper rotating body 4 are omitted.

[0046] The hydraulic system 40 has a hydraulic pump 42 driven by a prime mover 41, and a plurality of hydraulic actuators (boom hydraulic cylinder 15, stick hydraulic cylinder 16, bucket hydraulic cylinder 17) driven by hydraulic oil discharged from the hydraulic pump 42. Figure 2 The hydraulic pump 42 is, for example, a variable displacement type pump having a regulator 42a that controls the pump displacement. The regulator 42a adjusts the pump displacement, for example, in accordance with a control signal from a controller 80. The hydraulic oil discharged from the hydraulic pump 42 is supplied via flow control valves 45 to 47 corresponding to the respective hydraulic actuators 15 to 17.

[0047] The first flow control valve 45 controls the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 42 to the boom hydraulic cylinder 15. The first flow control valve 45 is of a hydraulic pilot type, and has pressure-receiving portions 45a, 45b on both sides for pilot pressure. The second flow control valve 46 controls the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 42 to the stick hydraulic cylinder 16. The second flow control valve 46 is of a hydraulic pilot type, and has pressure-receiving portions 46a, 46b on both sides for pilot pressure. The third flow control valve 47 controls the direction and flow rate of the hydraulic oil supplied from the hydraulic pump 42 to the bucket hydraulic cylinder 17. The third flow control valve 47 is of a hydraulic pilot type, and has pressure-receiving portions 47a, 47b on both sides for pilot pressure.

[0048] The hydraulic system 40 is basically configured to drive the boom hydraulic cylinder 15 by operation of a first operation device 51, drive the stick hydraulic cylinder 16 by operation of a second operation device 52, and drive the bucket hydraulic cylinder 17 by operation of a third operation device 53. The first operation device 51 and the third operation device 53, for example, share an operation lever 25b as shown in FIG. 1, and are configured as a cross operation type lever device 25 that indicates the operation of one of the boom hydraulic cylinder 15 and the bucket hydraulic cylinder 17 by tilting operation in the fore-aft direction, and indicates the operation of the other of the boom hydraulic cylinder 15 and the bucket hydraulic cylinder 17 by tilting operation in the left-right direction. In addition, the second operation device 52 and an operation device for rotation operation, not shown, for example, share an operation lever 25a as shown in FIG. 1, and are configured as a cross operation type lever device 25 that indicates the operation of one of the stick hydraulic cylinder 16 and the swing hydraulic motor 6 by tilting operation in the fore-aft direction, and indicates the operation of the other of the stick hydraulic cylinder 16 and the swing hydraulic motor 6 by tilting operation in the left-right direction. Figure 1 Figure 1

[0049] Each of the operation devices 51 to 53 is, for example, of a hydraulic pilot type, and is configured including a pair of pressure-reducing valves. Each of the operation devices 51 to 53 generates a pilot pressure (sometimes referred to as an operation pressure) corresponding to the operation amount and the operation direction of the operation lever 25a, 25b using the discharge pressure of a pilot pump 43 as a primary pressure. Note that, in the present embodiment, the operation devices 51 to 53 are configured to generate the pilot pressure by the pressure-reducing valves, but the present application is not limited to this. For example, the operation devices 51 to 53 can be configured to generate the pilot pressure by a proportional valve. Figure 2 ​​The pilot discharge line connecting the pilot pump 43 to each of the operation devices 51 to 53 is omitted.

[0050] On the first operation device 51, one of the pressure receiving portions 45a of the first flow control valve 45 is connected via one of the first pilot lines 55a, and the other of the pressure receiving portions 45b of the first flow control valve 45 is connected via the other of the first pilot lines 55b. The operation pressure (pilot pressure) output from the first operation device 51 is used as an operation signal (sometimes referred to as a first operation signal) for driving the first flow control valve 45.

[0051] The first electromagnetic proportional valve 61 (boom lowering deceleration valve) is provided on one of the first pilot lines 55a. The first electromagnetic proportional valve 61 reduces the pilot pressure (operation pressure) output from the first operation device 51 based on a control signal from the controller 80 and outputs the same as an operation signal (sometimes referred to as a second operation signal) to one of the pressure receiving portions 45a of the first flow control valve 45. When the pilot pressure (first operation signal or second operation signal) is applied to one of the pressure receiving portions 45a of the first flow control valve 45, hydraulic oil from the hydraulic pump 42 is supplied to the piston rod side of the boom hydraulic cylinder 15, the first flow control valve 45 is driven in the direction of the boom hydraulic cylinder 15 retraction drive, and a boom lowering operation is performed.

[0052] The discharge line 58 of the pilot pump 43 is connected to the other of the first pilot lines 55b via the first spool valve 71. The second electromagnetic proportional valve 62 (boom raising acceleration valve) is provided on the discharge line 58 connected to the first spool valve 71. The second electromagnetic proportional valve 62 outputs, as an operation signal (sometimes referred to as a second operation signal), a pilot pressure generated by reducing the discharge pressure of the pilot pump 43 based on a control signal from the controller 80 to the first spool valve 71. With regard to the first spool valve 71, the primary side port is connected to the first operation device 51 via the other of the first pilot lines 55b, and is connected to the secondary side of the second electromagnetic proportional valve 62 via the discharge line 58; the secondary side of the first spool valve 71 is connected to the other of the pressure receiving portions 45b of the first flow control valve 45 via the other of the first pilot lines 55b. That is, the first spool valve 71 selects the pilot pressure of the high pressure side between the pilot pressure (first operation signal) output from the first operation device 51 and the pilot pressure (second operation signal) output from the second electromagnetic proportional valve 62 and outputs the same to the other of the pressure receiving portions 45b of the first flow control valve 45. When the pilot pressure (first operation signal or second operation signal) is applied to the other of the pressure receiving portions 45b of the first flow control valve 45, hydraulic oil from the hydraulic pump 42 is supplied to the cylinder bottom side of the boom hydraulic cylinder 15, the first flow control valve 45 is driven in the direction of the boom hydraulic cylinder 15 elongation drive, and a boom raising operation is performed.

[0053] On the second operation device 52, the one side of the second flow control valve 46 is connected via one side of the second pilot line 56a, and the other side of the second flow control valve 46 is connected via the other side of the second pilot line 56b. The operation pressure (pilot pressure) output from the second operation device 52 is used as an operation signal (sometimes referred to as a first operation signal) for driving the second flow control valve 46.

[0054] The third electromagnetic proportional valve 63 (arm crowding down valve) is provided on the one side of the second pilot line 56a. The third electromagnetic proportional valve 63 reduces the pilot pressure (operation pressure) output from the second operation device 52 based on a control signal from the controller 80 and outputs it as an operation signal (sometimes referred to as a second operation signal) to the one side of the second flow control valve 46. When the pilot pressure (first operation signal or second operation signal) is applied to the one side of the second flow control valve 46, hydraulic oil from the hydraulic pump 42 is supplied to the piston rod side of the arm hydraulic cylinder 16, the second flow control valve 46 is driven in the direction of the arm retraction drive, and an arm crowding down operation is performed.

[0055] The fourth electromagnetic proportional valve 64 (arm recovery down valve) is provided on the other side of the second pilot line 56b. The fourth electromagnetic proportional valve 64 reduces the pilot pressure (operation pressure) output from the second operation device 52 based on a control signal from the controller 80 and outputs it as an operation signal (second operation signal) to the other side of the second flow control valve 46. When the pilot pressure (first operation signal or second operation signal) is applied to the other side of the second flow control valve 46, hydraulic oil from the hydraulic pump 42 is supplied to the cylinder bottom side of the arm hydraulic cylinder 16, the second flow control valve 46 is driven in the direction of the arm extension drive, and an arm recovery down operation is performed.

[0056] On the third operation device 53, the one side of the third flow control valve 47 is connected via one side of the third pilot line 57a, and the other side of the third flow control valve 47 is connected via the other side of the third pilot line 57b. The operation pressure (pilot pressure) output from the third operation device 53 is used as an operation signal (sometimes referred to as a first operation signal) for driving the third flow control valve 47.

[0057] A fifth electromagnetic proportional valve 65 (bucket discharge deceleration valve) is provided on the one third pilot line 57a. A discharge line 58 of the pilot pump 43 is connected to the portion of the one third pilot line 57a on the downstream side of the fifth electromagnetic proportional valve 65 via a second spool valve 72. A sixth electromagnetic proportional valve 66 (bucket discharge acceleration valve) is provided on the discharge line 58 connected to the second spool valve 72. The fifth electromagnetic proportional valve 65 reduces the pilot pressure (operation pressure) output from the third operation device 53 based on the control signal from the controller 80 and outputs it as an operation signal (second operation signal) to the second spool valve 72. The sixth electromagnetic proportional valve 66 outputs the pilot pressure generated by reducing the discharge pressure of the pilot pump 43 based on the control signal from the controller 80 as an operation signal (second operation signal) to the second spool valve 72. With respect to the second spool valve 72, the primary side port is connected to the secondary port side of the fifth electromagnetic proportional valve 65 via the one third pilot line 57a and to the secondary port side of the sixth electromagnetic proportional valve 66 via the discharge line 58; the secondary port side of the second spool valve 72 is connected to the one pressure receiving portion 47a of the third flow control valve 47 via the one third pilot line 57a. That is, the second spool valve 72 selects the pilot pressure on the high pressure side from among the pilot pressure (first operation signal or second operation signal) output from the fifth electromagnetic proportional valve 65 and the pilot pressure (second operation signal) output from the sixth electromagnetic proportional valve 66 and outputs it to the one pressure receiving portion 47a of the third flow control valve 47. When the pilot pressure (first operation signal or second operation signal) is applied to the one pressure receiving portion 47a of the third flow control valve 47, hydraulic oil from the hydraulic pump 42 is supplied to the piston rod side of the bucket hydraulic cylinder 17, the third flow control valve 47 is driven in the direction in which the bucket hydraulic cylinder 17 is retracted, the bucket discharge operation is performed.

[0058] A seventh electromagnetic proportional valve 67 (shovel recovery deceleration valve) is provided on the other party's third pilot line 57b. A discharge line 58 of the pilot pump 43 is connected to a portion of the other party's third pilot line 57b on the downstream side of the seventh electromagnetic proportional valve 67 via a third spool valve 73. An eighth electromagnetic proportional valve 68 (shovel recovery acceleration valve) is provided on the discharge line 58 connected to the third spool valve 73. The seventh electromagnetic proportional valve 67 reduces the pilot pressure (operation pressure) output from the third operation device 53 based on a control signal from the controller 80 and outputs the same to the third spool valve 73 as an operation signal (second operation signal). The eighth electromagnetic proportional valve 68 outputs the pilot pressure generated by reducing the discharge pressure of the pilot pump 43 based on a control signal from the controller 80 to the third spool valve 73 as an operation signal (second operation signal). With regard to the third spool valve 73, the primary side port is connected to the secondary port side of the seventh electromagnetic proportional valve 67 via the other party's third pilot line 57b and to the secondary port side of the eighth electromagnetic proportional valve 68 via the discharge line 58; the secondary side of the third spool valve 73 is connected to the other party's pressure receiving portion 47b of the third flow control valve 47 via the other party's third pilot line 57b. That is, the third spool valve 73 selects the pilot pressure of the high pressure side between the pilot pressure (first operation signal or second operation signal) output from the seventh electromagnetic proportional valve 67 and the pilot pressure (second operation signal) output from the eighth electromagnetic proportional valve 68 and outputs the same to the other party's pressure receiving portion 47b of the third flow control valve 47. When the pilot pressure (first operation signal or second operation signal) is applied to the other party's pressure receiving portion 47b of the third flow control valve 47, hydraulic oil from the hydraulic pump 42 is supplied to the cylinder bottom side of the shovel hydraulic cylinder 17, the third flow control valve 47 is driven in the direction in which the shovel hydraulic cylinder 17 is elongated, and a shovel recovery operation is performed.

[0059] Each of the electromagnetic proportional valves 61 to 68 is electrically connected to the controller 80 and controlled in opening degree by the exciting current (control signal) from the controller 80. The first, third, fourth, fifth, and seventh electromagnetic proportional valves 61, 63, 64, 65, and 67 are, for example, normally open electromagnetic valves whose opening degree is reduced to the minimum opening degree (e.g., opening degree 0) in proportion to an increase in the exciting current (control signal) from the controller 80. On the other hand, the second, sixth, and eighth electromagnetic proportional valves 62, 66, and 68 are normally closed electromagnetic valves whose opening degree is increased to the maximum opening degree in proportion to an increase in the exciting current (control signal) from the controller 80.

[0060] In this configuration, when the second, sixth, and eighth electromagnetic proportional valves 62, 66, 68 are driven in accordance with the control signal from the controller 80, the discharge pressure of the pilot pump 43 can be generated as the pilot pressure as the second operation signal without the operation of the operation devices 51, 53, even if the corresponding operation device 51, 53 is not operated, and the second operation signal can be applied to the pressure receiving portion 45b of the other side of the first flow control valve 45, the pressure receiving portions 47a, 47b of one or the other side of the third flow control valve 47. Thus, the boom raising operation, the bucket recovery / dispensing operation can be forcibly performed. In addition, when the electromagnetic proportional valves 61, 63, 64, 65, 67 are driven by the controller 80, the pilot pressure (second operation signal) reduced by the operation pressure generated by the operation of the operation devices 51 to 53 can be generated and applied to the pressure receiving portion 45a of one side of the first flow control valve 45, the pressure receiving portions 46a, 46b of one or the other side of the second flow control valve 46, the pressure receiving portions 47a, 47b of one or the other side of the third flow control valve 47. Thus, the speed of the boom lowering operation, the arm recovery / dispensing operation, the bucket recovery / dispensing operation can be forcibly reduced from the speed based on the operation amount of the operation devices 51 to 53.

[0061] The first and second pressure sensors 75a, 75b are provided on the first and second pilot lines 55a, 55b, respectively, to detect the pilot pressure (first operation signal) generated by the first operation device 51. The first and second pressure sensors 75a, 75b detect the pilot pressure generated by the first operation device 51 as the operation amount of the first operation device 51. The first pressure sensor 75a detects the operation amount of the boom lowering operation, and the second pressure sensor 75b detects the operation amount of the boom raising operation.

[0062] The third and fourth pressure sensors 76a, 76b are provided on the second and third pilot lines 56a, 56b, respectively, to detect the pilot pressure (first operation signal) generated by the second operation device 52. The third and fourth pressure sensors 76a, 76b detect the pilot pressure generated by the second operation device 52 as the operation amount of the second operation device 52. The third pressure sensor 76a detects the operation amount of the arm dispensing operation, and the fourth pressure sensor 76b detects the operation amount of the arm recovery operation.

[0063] The fifth and sixth pressure sensors 77a, 77b are provided on the third and fourth pilot lines 57a, 57b, respectively, to detect the pilot pressure (first operation signal) generated by the third operation device 53. The fifth and sixth pressure sensors 77a, 77b detect the pilot pressure generated by the third operation device 53 as the operation amount of the third operation device 53. The fifth pressure sensor 77a detects the operation amount of the bucket dispensing operation, and the sixth pressure sensor 77b detects the operation amount of the bucket recovery operation.

[0064] The pressure sensors 75a, 75b, 76a, 76b, 77a, 77b function as operation amount detection means 78 that detect operation amounts of the operation devices 51 to 53. As the operation amount detection means 78, each of the pressure sensors 75a, 75b, 76a, 76b, 77a, 77b is electrically connected to the controller 80 and outputs a detection value (detection signal) of a pilot pressure (first operation signal) of the operation devices 51 to 53 to the controller 80. Note that signal lines between each of the pressure sensors 75a, 75b, 76a, 76b, 77a, 77b and the controller 80 are omitted. Further, the calculation of the operation amount based on the pressure sensors 75a, 75b, 76a, 76b, 77a, 77b is merely an example, and for example, the operation amount can be detected using a position sensor (for example, a rotary encoder) that detects a rotational displacement of the operation lever 25a, 25b of each of the operation devices 51 to 53.

[0065] The controller 80 has a function of mechanical control (hereinafter referred to as MC) that, in a case where at least one of the first to third operation devices 51 to 53 for operating the front work device 1 is operated, intervenes in the operation under predetermined prescribed conditions to restrict the movement of the front work device 1. The MC is executed by controlling the first to eighth electromagnetic proportional valves 61 to 68 in accordance with the position of a control point (for example, a tooth tip of the bucket 13) of the front work device 1 and the operation condition of the operation devices 51 to 53. Details of the MC based on the controller 80 will be described later.

[0066] The MC switching means 28 is electrically connected to the controller 80. The MC switching means 28 is a switch for allowing the operator to select the effectiveness or ineffectiveness of the MC in an either-or manner, and is disposed in the cab 23 (see FIG. 1) inside the vehicle 10. The MC switching means 28 outputs an instruction signal (for example, an on signal or an off signal) indicating the selected effectiveness or ineffectiveness to the controller 80. Figure 1

[0067] ​In the above description, of the pilot pressures (operation signals) input to the pressure-receiving portions 45a, 45b, 46a, 46b, 47a, 47b of the flow control valves 45, 46, 47, the pilot pressure generated by operation of each of the operation devices 51 to 53 is referred to as a "first operation signal", and the pilot pressure generated by driving of each of the electromagnetic proportional valves 61 to 68 is referred to as a "second operation signal". In the second operation signal, there are included a pilot pressure generated by pressure-reducing correction of the pilot pressure (first operation signal) output from each of the operation devices 51 to 53 using the electromagnetic proportional valves 61, 63, 64, 65, 67, and a pilot pressure newly generated without using the first operation signal by pressure-reducing the discharge pressure of the pilot pump 43 using the electromagnetic proportional valves 62, 66, 68 without the aid of the operation devices 51 to 53.

[0068] The second operation signal is generated when the speed vector of the control point (for example, the tooth tip of the bucket) of the front work device 1 determined in accordance with the first operation signal violates a predetermined prescribed condition, and is generated as an operation signal that produces a speed vector of the control point of the front work device 1 that satisfies the prescribed condition. Note that, in the case where the first operation signal is generated with respect to one of the pressure-receiving portions of the same flow control valve 45, 46, 47, and the second operation signal is generated with respect to the other pressure-receiving portion, the second operation signal is given priority over the pressure-receiving portion. This can be achieved by cutting off the first operation signal using the electromagnetic proportional valve and inputting the second operation signal to the pressure-receiving portion. For the flow control valves 45 to 47 for which the second operation signal is calculated, control is performed based on the second operation signal; for the flow control valves for which the second operation signal is not calculated, control is performed based on the first operation signal; and for the flow control valves for which neither the first operation signal nor the second operation signal is generated, no control (driving) is performed. If the first operation signal and the second operation signal are defined as described above, the MC can be referred to as control of the flow control valves 45 to 47 based on the second operation signal.

[0069] Next, the functions of the controller in the first embodiment of the work machine of the present application will be described. Figure 3 is a block diagram showing the hardware and functions of the controller that constitutes part of the first embodiment of the work machine of the present application. Figure 3 is a block diagram showing the hardware and functions of the controller that constitutes part of the first embodiment of the work machine of the present application.

[0070] When the controller 80 receives a valid instruction (on signal) for the MC from the MC switching device 28, it executes the MC of the front working device 1. The MC of the front working device 1 controls its operation, for example, by inputting a digging operation (specifically, at least one of boom retraction, bucket retraction, and bucket extension) via the second or third operating devices 52, 53. A control signal (e.g., a control signal to extend the boom cylinder 15 and force a boom lifting action) is output to corresponding flow control valves 45, 46, 47, in a manner that forces at least one of the boom hydraulic cylinder 15, boom hydraulic cylinder 16, and bucket hydraulic cylinder 17 to move, based on the positional relationship between the control point of the front working device 1 (e.g., the tip of the bucket 13) and the target surface (not shown), so that the control point of the front working device 1 is held in the area on or above the target surface. This MC prevents the control point of the front working device 1 from encroaching below the target surface, allowing digging along the target surface regardless of the operator's skill level. It should be noted that the control point of the front working device 1 in MC only needs to be the front end of the front working device 1, and can be selected from the tip of the bucket 13, the bottom surface, or the outermost part of the connecting rod component 18 of the bucket 13, etc.

[0071] like Figure 3 As shown, the controller 80, as a hardware structure, includes, for example, a storage device 81 composed of RAM, ROM, etc., and a processing device 82 composed of CPU, MPU, etc. The storage device 81 pre-stores the programs and various information required to execute the MC of the front-end operation device 1. The processing device 82 appropriately reads the programs and various information from the storage device 81 and performs processing according to the programs to realize various functions, including the following.

[0072] The controller 80 has an MC calculation unit 91, a display control unit 92, an electromagnetic proportional valve control unit 93, and a regulator control unit 94, which are functions performed by the processing device 82.

[0073] The detection signal of the posture information (specifically, the boom angle, the arm angle, the bucket angle, and the body angle) of the front working device 1 detected by the posture detection device 30 is input to the MC arithmetic unit 91. In addition, the detection signal of the operation amount (specifically, the pilot pressure output from each of the operation devices 51 to 53) of each of the operation devices 51 to 53 detected by the operation amount detection device 78 is input. Further, the instruction signal (specifically, the on signal instructing the MC to be effective or the off signal instructing the MC to be ineffective) from the MC switch device 28 is input. In addition to these, the information of the target surface is input from the target surface setting device 101. The target surface setting device 101 is an interface that inputs the information of the target surface (specifically, the position information of the target surface, the inclination angle, and the like). The target surface setting device 101 can be connected to an external terminal (not shown) in which three-dimensional data of the target surface defined in a global coordinate system (absolute coordinate system) is stored, for example, and can input the three-dimensional data of the target surface from the external terminal. However, the target surface can also be input to the controller 80 by the operator manually via the target surface setting device 101.

[0074] The MC arithmetic unit 91 is a portion that performs an operation for executing the MC that forcibly moves or restricts the movement of at least one of the boom hydraulic cylinder 15, the arm hydraulic cylinder 16, and the bucket hydraulic cylinder 17 so that the front working device 1 moves in accordance with a predetermined prescribed condition in response to the operation of the operation devices 51 to 53 performed by the operator. The MC arithmetic unit 91 performs an operation for executing the MC in response to the operation of the operation devices 51 to 53 when the instruction signal (on signal) instructing the MC to be effective is input from the MC switch device 28, and performs an operation for executing a control corresponding to the operation of the operation devices 51 to 53 when the instruction signal (off signal) instructing the MC to be ineffective is input from the MC switch device 28. The MC arithmetic unit 91 finally calculates the position of the posture and the control point (for example, the position of the tooth tip of the bucket 13), the position of the target surface, the target pilot pressure of the flow control valves 45, 46, and 47 corresponding to each of the hydraulic actuators 15, 16, and 17, and the target pump displacement of the hydraulic pump 42 on the basis of the detection signal from the posture detection device 30, the detection signal from the operation amount detection device 78, and the information from the target surface setting device 101. Details of the functions of the MC arithmetic unit 91 will be described later.

[0075] The display control section 92 controls the display of the display device 27. The display control section 92 controls the display of the display device 27 based on the flag included in the input information from the MC arithmetic section 91, reading a prescribed program from the storage device 81. Specifically, the display control section 92 displays the positional relationship of the front work machine 1 and the target surface on the display screen of the display device 27 based on the posture of the front work machine 1, the position of the tooth tip of the shovel 13, and the position of the target surface as the operation result of the MC arithmetic section 91. The storage device 81 has a display ROM in which a large amount of display-related data including images and icons of the front work machine 1 is stored, and the display control section 92 uses various image data and the like stored in the display ROM.

[0076] The electromagnetic proportional valve control section 93 controls the operation (direction and speed) of the hydraulic actuators 15 to 17 that drive the front work machine 1 by means of the first to eighth electromagnetic proportional valves 61 to 68 of the hydraulic system 40. Specifically, the electromagnetic proportional valve control section 93 operates the opening degree command of the electromagnetic proportional valves 61 to 68 corresponding to the flow control valves 45 to 47 corresponding to the hydraulic actuators 15 to 17 based on the pilot pressure command (target pilot pressure) of each flow control valve 45 to 47 corresponding to the hydraulic actuators 15 to 17 as the operation result of the MC arithmetic section 91, and outputs a control signal (excitation current) corresponding to the operation result to each electromagnetic proportional valve 61 to 68.

[0077] The regulator control section 94 controls the pump displacement of the hydraulic pump 42 by means of the regulator 42a of the hydraulic pump 42. Specifically, the regulator control section 94 operates the displacement command for the regulator 42a of the hydraulic pump 42 based on the target pump displacement of the hydraulic pump 42 as the operation result of the MC arithmetic section 91, and outputs a control signal corresponding to the operation result to the regulator 42a.

[0078] Next, the detailed description of the functional structure of the MC arithmetic section of the controller in the first embodiment of the work machine of the present application will be described using Figure 4 and Figure 5 . Figure 4 is a block diagram showing the functions of the MC arithmetic section of the controller shown in Figure 3 . Figure 5 is an explanatory diagram showing the operation method of the speed and posture prediction section and the speed command operation section of the controller shown in Figure 4 .

[0079] In the above-described first embodiment of the work machine of the present application, the MC arithmetic section of the controller is configured to perform the operation of the speed and posture prediction section and the speed command operation section as described above. Figure 4In the embodiment, the MC arithmetic unit 91 of the controller 80 is detailed to have an MC determination unit 911, a posture arithmetic unit 912, a target surface arithmetic unit 913, an operation amount arithmetic unit 914, a speed and posture prediction unit 915, a speed command arithmetic unit 916, an actuator control unit 917, and a hydraulic pump control unit 918. Each of the functional units of the MC arithmetic unit 91 repeatedly performs various operations shown below in accordance with an operation cycle.

[0080] The MC determination unit 911 determines the validity or invalidity of the MC based on an instruction signal from the MC switching device 28. The MC switching device 28 outputs the determination result of the validity or invalidity of the MC to the speed and posture prediction unit 915.

[0081] The posture arithmetic unit 912 calculates the posture of the front working device 1 and the position of the control point based on a detection signal from the posture detection device 30. For example, the posture of the front working device 1 and the three-dimensional coordinates of the tooth tip position of the bucket 13 in the local coordinate system are calculated. Since this calculation is performed in accordance with general geometric relationships, detailed description is omitted. The calculation result of the posture arithmetic unit 912, i.e., the posture of the front working device 1 and the position of the control point, is output to the display control unit 92 and the speed and posture prediction unit 915.

[0082] The target surface arithmetic unit 913 calculates the position information of the target surface based on information from the target surface setting device 101. The position information of the target surface as the calculation result is output to the display control unit 92 and the speed and posture prediction unit 915. Note that the position information of the target surface can also be stored in the storage device 81.

[0083] The operation amount arithmetic unit 914 calculates the operation amounts of the respective operation devices 51 to 53 based on detection signals from the operation amount detection devices 78. The operation amount of the boom lowering is calculated based on the detection value of the first pressure sensor 75a, and the operation amount of the boom raising is calculated based on the detection value of the second pressure sensor 75b. The operation amount of the stick extension is calculated based on the detection value of the third pressure sensor 76a, and the operation amount of the stick retraction is calculated based on the detection value of the fourth pressure sensor 76b. The operation amount of the bucket extension is calculated based on the detection value of the fifth pressure sensor 77a, and the operation amount of the bucket retraction is calculated based on the detection value of the sixth pressure sensor 77b. The operation amounts of the respective operation devices 51 to 53 as the calculation result of the operation amount arithmetic unit 914 are output to the speed command arithmetic unit 916.

[0084] The speed and posture prediction unit 915 calculates predicted values of the speeds of the hydraulic actuators 15 to 17 of the front work implement 1 at a future time after a predetermined set time from the current time at which the calculation is performed (the current calculation cycle), and predicted values of the posture of the front work implement 1 and the position of the control point with respect to the target surface. Specifically, for example, the predicted values at the future time after the set time from the current time are calculated on the basis of the posture of the front work implement 1 and the position of the control point at the current time (the current calculation cycle) as the result of the calculation by the posture calculation unit 912, the position information of the target surface as the result of the calculation by the target surface calculation unit 913, and the past history (history) of the speed commands of the hydraulic actuators 15 to 17 that will be described later, which are calculated by the speed command calculation unit 916 from a past time (past calculation cycle) before the current time (the current calculation cycle) to the current time. As the set time, for example, a first time T1 that is substantially identical to the response delay of the actual speed of each hydraulic actuator 15 to 17 with respect to the speed command is set. The result of the calculation (the predicted value) by the speed and posture prediction unit 915 is output to the speed command calculation unit 916. However, the speed and posture prediction unit 915 is configured to perform the calculation of the predicted values in the case where the valid determination result of the MC is input from the MC determination unit 911, and not to perform the calculation of the predicted values in the case where the invalid determination result of the MC is input from the MC determination unit 911. The detailed calculation method of the speed and posture prediction unit 915 will be described later.

[0085] In the case where the determination result of the MC determination unit 911 is valid, the speed command calculation unit 916 calculates the speeds of the boom hydraulic cylinder 15 (the boom 11), the stick hydraulic cylinder 16 (the stick 12), and the bucket hydraulic cylinder 17 (the bucket 13) that are required at a future time after a set time from the current time (the current calculation cycle) as target speeds of the hydraulic actuators so that the control point of the front work implement 1 is positioned on the target surface at the future time after the set time from the current time (the current calculation cycle). This calculation is premised on the fact that the control point (for example, the tooth tip of the bucket 13) of the front work implement 1 is already positioned in the vicinity of the target surface, and is performed to control the operation of the front work implement 1 in such a manner that the control point of the front work implement 1 does not intrude below the target surface and moves along the target surface. In addition, this calculation is performed to control the operation of the boom hydraulic cylinder 15 on the basis of the operation of at least one of the stick hydraulic cylinder 16 and the bucket hydraulic cylinder 17 under the above condition. That is, in the present embodiment, the boom hydraulic cylinder 15 is targeted for the forced operation or the restricted operation on the basis of the MC.

[0086] Specifically, the speed command operation section 916 operates the target speed of the boom hydraulic cylinder 15, the arm hydraulic cylinder 16, and the bucket hydraulic cylinder 17 at a future time after the first time Tl from the current time (current operation period) based on the operation amounts of the operation devices 52, 53 as the detection results of the operation amount detection section 78. In addition, the speed command operation section 916 operates the target speed of the boom hydraulic cylinder 15 at a future time after the first time Tl from the current time (current operation period) based on the predicted values of the speeds of the hydraulic actuators 15 to 17 and the predicted values of the posture of the front working device 1 and the position of the control point with respect to the target surface as the operation results of the speed and posture prediction section 915. The speed command operation section 916 outputs the target speeds of the hydraulic actuators 15 to 17 as operation results as the speed commands of the current time (current operation period) to the actuator control section 917 and the hydraulic pump control section 918. Details of the operation method of the speed command operation section 916 will be described later.

[0087] In addition, in a case where the determination result of the MC determination section 911 is invalid for the MC, the speed command operation section 916 operates the target speeds of the hydraulic actuators 15 to 17 based on the operation amounts of the operation devices 51 to 53 as the detection results of the operation amount detection section 78. That is, the operation of each of the hydraulic actuators 15 to 17 is controlled in accordance with the operation of the operation devices 51 to 53 by the operator, and the forced operation and the restricted operation of the boom hydraulic cylinder 15 that are not dependent on the operation of the operation device 51 by the operator are not performed.

[0088] The actuator control section 917 performs an operation for controlling each of the hydraulic actuators 15 to 17. Specifically, the target pilot pressures of the flow control valves 45 to 47 corresponding to the hydraulic actuators 15 to 17 are operated based on the speed commands of the hydraulic actuators 15 to 17 as the operation results of the speed command operation section 916. The actuator control section 917 is constituted by a boom control section 917a that controls the first flow control valve 45 corresponding to the boom hydraulic cylinder 15, an arm control section 917b that controls the second flow control valve 46 corresponding to the arm hydraulic cylinder 16, and a bucket control section 917c that controls the third flow control valve 47 corresponding to the bucket hydraulic cylinder 17.

[0089] The boom control unit 917a calculates the target pilot pressure of the first flow control valve 45 based on the speed command of the boom hydraulic cylinder 15, which is the result of the calculation by the speed command calculation unit 916, and outputs the calculated target pilot pressure as the pilot pressure command of the first flow control valve 45 to the electromagnetic proportional valve control unit 93. The stick control unit 917b calculates the target pilot pressure of the second flow control valve 46 based on the speed command of the stick hydraulic cylinder 16, which is the result of the calculation by the speed command calculation unit 916, and outputs the calculated target pilot pressure as the pilot pressure command of the second flow control valve 46 to the electromagnetic proportional valve control unit 93. The bucket control unit 917c calculates the target pilot pressure of the third flow control valve 47 based on the speed command of the bucket hydraulic cylinder 17, which is the result of the calculation by the speed command calculation unit 916, and outputs the calculated target pilot pressure as the pilot pressure command of the third flow control valve 47 to the electromagnetic proportional valve control unit 93.

[0090] The hydraulic pump control unit 918 performs calculations to control the pump volume of the hydraulic pump 42. Specifically, it calculates the target pump volume of the hydraulic pump 42 based on the speed commands of multiple hydraulic actuators 15-17, which are the calculation results of the speed command calculation unit 916. The calculated target pump volume of the hydraulic pump 42 is then output to the regulator control unit 94 as a pump volume command.

[0091] Next, use Figure 4-6 An example of the calculation method of the speed and posture prediction unit and the speed command calculation unit in the controller of the working machine constituting part of the first embodiment of the present invention will be described. Figure 5 It means Figure 4 A flowchart illustrating an example of the processing steps in the speed and attitude prediction unit and speed command calculation unit of the controller shown. Figure 6 It means Figure 4 The diagram illustrates the calculation methods of the speed and attitude prediction unit and the speed command calculation unit of the controller. It should be noted that... Figure 5 The flowchart shown illustrates the computational processing corresponding to one computation cycle. Figure 6 In the diagram, the upper image shows information related to the speed of the stick hydraulic cylinder, and the lower image shows information related to the speed of the boom hydraulic cylinder. Additionally, solid lines represent the actual speed of the hydraulic actuator, dashed lines represent the speed command of the hydraulic actuator, and single-dot lines represent the predicted speed of the hydraulic actuator.

[0092] Figure 4 The velocity and attitude prediction unit 915 in the MC calculation unit 91 shown first obtains the determination result of the MC determination unit 911. Figure 5 The flowchart shown in step S10) determines whether to execute MC based on the determination result (valid or invalid) obtained by the MC determination unit 911. Figure 5The step S20) shown. In the case where the determination result of the MC determination section 911 is valid (on), it is determined that the MC is executed (Yes); on the other hand, in the case where the determination result of the MC determination section 911 is invalid (off), it is determined that the MC is not executed (No). In the case where it is determined Yes in the step S20, the process proceeds to a step S30, and in the case where it is determined No, the process proceeds to a step S200.

[0093] In the case where it is determined Yes in the step S20, the speed and posture prediction section 915 acquires position information of the target surface (target surface 1) calculated by the target surface calculation section 913 based on the information from the target surface setting device 101 (step S30) shown. Figure 5

[0094] Moreover, information of the posture of the front working device 1 and the position of the control point (for example, the tip of the bucket 13) calculated by the posture calculation section 912 based on the detection signal of the posture detection device 30 is acquired (step S40) shown. Based on this acquired information, the actual speed of each hydraulic actuator 15 to 17 at the current time (current calculation cycle) is calculated (step S50) shown. Figure 5 Figure 5 Specifically, the speed of each hydraulic actuator 15 to 17 at the current time (actual speed) is calculated from the difference between the posture of each hydraulic actuator (boom hydraulic cylinder 15, stick hydraulic cylinder 16, bucket hydraulic cylinder 17) acquired in the current calculation cycle and the posture of each hydraulic actuator 15 to 17 acquired in the calculation cycle one cycle before the current calculation cycle. This calculation corresponds to the black dot in the upper diagram of FIG. 8 at the current time (current calculation cycle). However, in the case where the stick hydraulic cylinder 16 is shown in FIG. 8, Figure 6 Figure 6

[0095] Next, the speed and posture prediction section 915 calculates the history of the predicted value of the speed of each hydraulic actuator 15 to 17 from the current time (current calculation cycle) to the future time (hereinafter sometimes referred to as the first future time) after the elapse of the first time T1 (step S60) shown. Figure 5 ​​​​(See step S60). Specifically, the past history of the speed commands of each hydraulic actuator 15 to 17 calculated and output by the speed command calculation unit 916 during the period from a past time (hereinafter sometimes referred to as the first past time) before the current time (current operation cycle) to the current time (current operation cycle) is transferred relative to the speed (actual speed) of each hydraulic actuator 15 to 17 at the current time calculated in step S50, and the speed commands of each hydraulic actuator 15 to 17 output by the speed command calculation unit 916 at the first past time are made consistent with the speed (actual speed) of each hydraulic actuator 15 to 17 at the current time calculated in step S50. The history of the speed commands of each hydraulic actuator 15 to 17 in the past operation cycle after this transfer is regarded as the history of the predicted speed of each hydraulic actuator 15 to 17 from the current time to the first future time. That is, based on the current speed (actual speed) of each hydraulic actuator 15-17, and based on the past history of speed commands for each hydraulic actuator 15-17 output from the speed command calculation unit 916 during the period from the first past time to the present time, the future history of the speed of each hydraulic actuator 15-17 within the time interval from the present time to the first future time is predicted. This takes into account the case where the speed commands for each hydraulic actuator 15-17 are achieved as the actual speed of each hydraulic actuator 15-17 with a response delay of the first time T1.

[0096] This operation is equivalent to Figure 6 The I (transfer) portion shown. That is, in Figure 6 In the above diagram, it is equivalent to transferring the dashed line (speed commands of each hydraulic actuator 15-17) from the first past time (t0-T1) to the current time (t0) so that the black dot of the speed command at the first past time (t0-T1) aligns with the black dot of the actual speed at the current time (t0), thereby generating a single-dot line (predicted speed values ​​of each hydraulic actuator 15-17) from the current time (t0) to the first future time (t0+T1). However, in Figure 6 Only the case of the boom hydraulic cylinder 16 is shown. That is to say, the history of the speed prediction values ​​for the boom hydraulic cylinder 15 and the bucket hydraulic cylinder 17 is also compared with... Figure 6 The operation equivalent to I (transfer) shown is...

[0097] Next, the speed and attitude prediction unit 915 predicts the extension and retraction lengths of each hydraulic actuator 15-17 generated during the period from the current moment to the first future moment. Figure 5The step S70) shown. Specifically, the history of the predicted value of the speed of each hydraulic actuator 15 to 17 in the period from the current time to the first future time calculated in the step S60 is integrated in the time interval from the current time to the first future time, whereby the prediction of the extension / contraction length of each hydraulic actuator 15 to 17 generated in the period from the current time to the first future time is calculated.

[0098] This calculation corresponds to the portion II (integral = extension / contraction length) shown in the upper drawing of Figure 6 . That is, in the upper drawing of Figure 6 , the area of the oblique line portion enclosed by the time interval from the current time (to) to the first future time (to + Ti) and the single-dot chain line (history of the predicted value of the speed of each hydraulic actuator 15 to 17) corresponds to the predicted value of the extension / contraction length of each hydraulic actuator 15 to 17. However, in the lower drawing of Figure 6 , only the case of the boom cylinder 16 is shown. That is, the predicted value of the extension / contraction length of the arm cylinder 15 and the bucket cylinder 17 is also calculated by the calculation corresponding to the portion II (integral = extension / contraction length) shown in Figure 6 .

[0099] Further, the speed and posture prediction section 915 predicts the posture of the front working device 1 at the first future time and the position of the control point with respect to the target surface (for example, the distance from the control point to the target surface) (step S80 shown in Figure 5 ). Specifically, based on the posture of the front working device 1 at the current time (posture of the boom 11, the stick 12, and the bucket 13) and the position of the control point (for example, the tooth tip of the bucket 13) acquired in the step S40, the predicted value of the extension / contraction length of each hydraulic actuator 15 to 17 at the first future time calculated in the step S70, and the position information of the target surface acquired in the step S30, the posture of the front working device 1 at the first future time and the position of the control point with respect to the target surface (for example, the distance from the control point to the target surface) are calculated. The speed and posture prediction section 915 outputs the posture of the front working device 1 at the first future time and the position of the control point with respect to the target surface as the calculation result of the step S80, and the predicted value of the speed of each hydraulic actuator 15 to 17 at the first future time as the calculation result of the step S60 to the speed command calculation section 916.

[0100] Next, the speed command calculation section 916 calculates the target speed of the boom cylinder 15 required to satisfy the above-described condition at the first future time (step S90 shown in Figure 5The step S90) shown. Specifically, based on the predicted value of the posture of the front work implement 1 at the first future time and the predicted value of the position of the control point with respect to the target surface, which are calculated in the step S80, and the predicted value of the speed of each hydraulic actuator 15 to 17 at the first future time, which is calculated in the step S60, the speed of the boom hydraulic cylinder 15 that can make the control point of the front work implement 1 be on the target surface at the first future time is calculated as a target speed at the first future time.

[0101] Figure 5 The calculation of the steps S60 to S80 shown is equivalent to Figure 6 The part shown from I (transferred) through II (integrated = extension length) and III (target speed at future time) obtained by the arrow. This calculation is a part in which the command of the forced action of the boom hydraulic cylinder 15 based on the activation of the MC that is not dependent on the operation of the operation device 51 is calculated based on the operation of the operation device 52, 53, of at least one of the arm cylinder 16 and the bucket hydraulic cylinder 17.

[0102] Further, the speed command calculation section 916 acquires the calculation result of the operation amount calculation section 914, that is, the pilot pressure (first operation signal) Figure 5 shown in the step S100), and calculates the target speed of the arm hydraulic cylinder 16 at the first future time Figure 5 shown in the step S110) based on the acquired pilot pressure. For example, with reference to the characteristic map 916a Figure 5 shown, the target speed of the arm hydraulic cylinder 16 is calculated. In the characteristic map 916a Figure 5 shown, the target speed of the arm hydraulic cylinder 16 is set in such a manner that it is 0 when the pilot pressure (first operation signal) of the second operation device 52 is within a certain range (dead zone) including 0, it increases in proportion to the increase of the pilot pressure if the pilot pressure exceeds the dead zone, and thereafter, it becomes a constant value if the pilot pressure exceeds a certain value.

[0103] In this description, it is assumed that the boom hydraulic cylinder 15 is controlled by the MC in a case where the second operation device 52 for the arm hydraulic cylinder 16 is operated by the operator. Therefore, the operation amount of the third operation device 53 for the bucket hydraulic cylinder 17 is 0, and thus the description of the calculation of the target speed of the bucket hydraulic cylinder 17 is omitted. However, in a case where the third operation device 53 for the bucket hydraulic cylinder 17 is also operated, as in the case of the arm hydraulic cylinder 16, the pilot pressure (first operation signal) Figure 5The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). Figure 5 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110).

[0104] Finally, the speed command calculation section 916 outputs the target speed of the boom hydraulic cylinder 15 at the first future time calculated in step S90 as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle), and outputs the target speed of the stick hydraulic cylinder 16 at the first future time calculated in step S110 as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle). Figure 6 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). Figure 5 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). Figure 5 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). The speed command of each hydraulic actuator 15 to 17 is outputted to the actuator control section 917 and the hydraulic pump control section 918. With the end of step S120, the current calculation cycle ends, and the process returns to the start to start the next calculation cycle.

[0105] On the other hand, in the case where the determination in step S20 is NO, the speed command calculation section 916 acquires the calculation results of the operation amount calculation section 914, i.e., the pilot pressures as the operation amounts of each operation device 51 to 53 corresponding to each hydraulic actuator 15 to 17 (step S200), and calculates the target speeds of each hydraulic actuator 15 to 17 at the first future time on the basis of the acquired pilot pressures of each operation device 51 to 53 (step S210). Figure 5 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). Figure 5 The target speed of the boom hydraulic cylinder 15 at the first future time is outputted as the speed command of the boom hydraulic cylinder 15 at the current time (current calculation cycle) (step S90). The target speed of the stick hydraulic cylinder 16 at the first future time is outputted as the speed command of the stick hydraulic cylinder 16 at the current time (current calculation cycle) (step S110). Figure 5 The target speed of each hydraulic actuator 15 to 17 is calculated with reference to the characteristic map 916b shown in FIG. 9B, for example. Figure 5The characteristic map 916b shown is set in the same manner as the characteristic map 916a. In this case, the speed and posture prediction section 915 does not predict the posture of the front working device 1 and the position of the control point with respect to the target surface, and the speed of each hydraulic actuator 15 to 17 of the front working device 1. That is, the speed command calculation section 916 calculates the target speed of the boom hydraulic cylinder 15 corresponding to the boom raising pilot pressure or the boom lowering pilot pressure, calculates the target speed of the stick hydraulic cylinder 16 corresponding to the stick retracting pilot pressure or the stick extending pilot pressure, and calculates the target speed of the bucket hydraulic cylinder 17 corresponding to the bucket retracting pilot pressure or the bucket extending pilot pressure.

[0106] The speed command calculation section 916 finally outputs the target speed of each hydraulic actuator 15 to 17 at the first future time calculated in step S210 as the speed command of each hydraulic actuator 15 to 17 at the current time (current calculation cycle) to the actuator control section 917 and the hydraulic pump control section 918 (step S220). Figure 5 That is, the MC calculation section 91 calculates the speed command instructing the operation of each hydraulic actuator 15 to 17 in accordance with the operation of the operating devices 51 to 53. The current calculation cycle ends with the end of step S220, and returns to the start to start the next calculation cycle.

[0107] Next, the use of the characteristic map 916b will be described. Figure 5 and Figure 5 The operation and effects of the first embodiment of the working machine of the present application will be described. Figure 5 is an explanatory diagram showing the relationship between the target speed, the speed command, and the actual speed of each hydraulic actuator when the MC is executed in response to the stick retracting operation of the second operating device in the first embodiment of the working machine of the present application. In Figure 5 , the upper diagram shows the time history of the operation amount of the second operating device for the stick operation, the middle diagram shows the time history of the target speed, the speed command, and the actual speed of the stick hydraulic cylinder, and the lower diagram shows the time history of the target speed, the speed command, and the actual speed of the boom hydraulic cylinder.

[0108] Here, a case where the MC-based horizontal digging operation is performed by the stick retracting operation of the second operating device 52 input by the operator will be described. In this case, the MC switching device 28 is switched to the active position.

[0109] In Figure 5 , the first period SI is a period in which the operator does not perform the operation of the second operating device 52. The second period S2 is a period in which the operation of the second operating device 52 is performed, but the operation of the second operating device 52 does not cause the operation of the stick hydraulic cylinder due to the influence of the response delay. The third period S3 is a period in which the stick hydraulic cylinder is operated by the operation of the second operating device 52.

[0110] Controller 80 in Figure 5 If the determination in step S20 of the flowchart shown is yes, then the processing steps S30 to S120 are executed.

[0111] During the first period S1, the second operating device 52 was not operated. Therefore, the speed (actual speed) of each hydraulic actuator 15-17 at the current moment, as calculated by the speed and posture prediction unit 915, is 0. Figure 5 As shown in step S50), the predicted speeds of each hydraulic actuator 15-17 at the first future time (the future time after the first time T1 from the current time) are also 0. Figure 5 (See step S60). Based on the calculation results of these speed and attitude prediction units 915, the predicted value (calculation result) of the extension length of each hydraulic actuator 15-17 at the first future moment is 0 ( Figure 8-11 In step S70 shown, the predicted value (calculation result) of the posture of the front working device 1 and the position of the control point relative to the target surface at the first future time has not changed compared to the posture of the front working device 1 and the position of the control point relative to the target surface at the current time (current calculation cycle), and is the same value. Figure 8 (Step S80 shown). Therefore, the target speed of the boom hydraulic cylinder 16 and the boom hydraulic cylinder 15, which are the results of the calculation by the speed command calculation unit 916, is 0 ( Figure 9 (See steps S90 to S110). Therefore, during the first period S1, the speed command calculation unit 916 outputs the target speed of 0 as the speed command for the current moment.

[0112] During the second period S2, since the stick recovery operation of the second operation device 52 was input, the speed command calculation unit 916, based on the operation amount detection device 78, performs the operation command calculation based on the operation amount detection device 78. Figure 8 The target velocity of the first future moment of the boom hydraulic cylinder 16 is calculated by using the detection signal of the fourth pressure sensor 76b (shown) and the corresponding boom recovery pilot pressure. Figure 10 The steps S100 to S110 are shown, and the target speed of the calculation result is output as the speed command of the boom hydraulic cylinder 16 at the current moment (current calculation cycle). Figure 8 (See step S120). That is, during the second period S2, a speed command is output for the stick hydraulic cylinder 16 corresponding to the stick retraction operation of the second operating device 52. However, due to the effect of the response delay of the actual speed of the stick hydraulic cylinder 16 relative to the speed command, the operation of the stick hydraulic cylinder 16 does not begin. It should be noted that, in this description, since the third operating device 53 for bucket operation is not operated, the target speed and speed command of the bucket hydraulic cylinder 17 at the first future moment are always 0.

[0113] Furthermore, since the boom hydraulic cylinder 16 has not yet started moving, the current speed (actual speed) of each hydraulic actuator 15-17, as calculated by the speed and attitude prediction unit 915, is 0. Figure 11 (See step S50). On the other hand, the past history of the speed command of the boom hydraulic cylinder 16 output by the speed command calculation unit 916 during the period from the first past moment (a past moment before the first time T1 compared to the current moment) to the current moment is not 0 in the second period S2 as described above. Therefore, based on the past history of the speed command of the boom hydraulic cylinder 16, the history of the predicted value of the speed of the boom hydraulic cylinder 16 from the current moment to the first future moment is calculated. Figure 8-11 Step S60 is shown. Based on the calculation results of these speed and attitude prediction units 915, the predicted values ​​of the extension and retraction lengths of each hydraulic actuator 15 to 17 at the first future moment are calculated. Figure 1-7 Step S70 (as shown) is performed, and the predicted values ​​of the posture of the front working device 1 and the position of the control point relative to the target surface at the first future time are calculated. Figure 8 Step S80 (as shown).

[0114] The speed command calculation unit 916 calculates the target speed of the boom hydraulic cylinder 15 at the first future moment based on these predicted values, which meets the specified conditions. Figure 9 (Step S90 shown). The target speed of the boom hydraulic cylinder 15 at the first future moment, obtained from the calculation, is output as the speed command at the current moment (current calculation cycle). Figure 10 (See step S120). That is, even if the first operating device 51 for boom operation is not operated, a command to force the boom hydraulic cylinder 15 to operate under specified conditions is generated. In addition, the history of the speed command of the boom hydraulic cylinder 15 output from the speed command calculation unit 916 in the second period S2 is used to calculate the predicted value of the speed of the boom hydraulic cylinder 15 at the first future time, the predicted value of the extension length of the boom hydraulic cylinder 15, the posture of the front working device 1, and the predicted value of the position of the control point relative to the target surface.

[0115] Thus, in the second period S2, the boom cylinder 16 does not start to act in response to the bucket cylinder retraction operation of the second operating device 52 due to the influence of the response delay. However, in the present embodiment, by predicting the actuation of each hydraulic actuator 15 to 17 at a first future time after the elapse of the first time Tl from the operation period in which the speed command of each hydraulic actuator 15 to 17 is calculated, the speed command of the boom cylinder 15 at the current time (current operation period) taking into account the response delay of the actual speed of each hydraulic actuator 15 to 17 with respect to the speed command can be output. That is, in the case where the second operating device 52 is operated, even before the boom cylinder 16 actually starts to act, by outputting in advance the speed command of the boom cylinder 15 corresponding to the predicted actuation of the boom cylinder 16, the execution of the MC taking into account the response delay of each hydraulic actuator 15 to 17 can be realized.

[0116] In addition, in the third period S3, the bucket cylinder retraction operation of the second operating device 52 is continued, and the time of the response delay (approximately the first time Tl) has elapsed from the start of the bucket cylinder retraction operation. Therefore, the boom cylinder 16 acts in response to the bucket cylinder retraction operation with the time of the response delay.

[0117] In this case, the speed command calculation section 916 calculates the target speed of the boom cylinder 16 at the first future time corresponding to the bucket cylinder retraction operation, and outputs the target speed of the calculation result as the speed command of the boom cylinder 16 at the current time (current operation period) as in the case of the second period S2 (steps S100 to S120 shown in FIG. 10). Figure 9

[0118] In addition, unlike the case of the second period S2, the boom cylinder 16 and the boom cylinder 15 are being actuated, and therefore the speed and posture prediction section 915 calculates the speed of each hydraulic actuator 15 to 17 at the current time (not 0) (step S50 shown in FIG. 11). Moreover, based on the past history of the speed of each hydraulic actuator 15 to 17 at the current time of the calculation result and the speed command of each hydraulic actuator 15 to 17 output by the speed command calculation section 916, the history of the predicted value of the speed of each hydraulic actuator 15 to 17 is calculated (step S60 shown in FIG. 11). From these calculation results of the speed and posture prediction section 915, the predicted value of the extension length of each hydraulic actuator 15 to 17 at the first future time is calculated (step S70 shown in FIG. 11), and the predicted value of the posture of the front working device 1 and the position of the control point with respect to the target surface at the first future time is calculated (step S80 shown in FIG. 11). Figure 10 Figure 8 Figure 9 Figure 9 ​​​​The step S80) shown. That is, the prediction operation of the speed and posture prediction section 915 also includes the influence of the actual operation (actual speed) of the hydraulic actuators 15 to 17, unlike the case of the second period S2.

[0119] The speed command operation section 916, as in the case of the second period S2, operates the target speed of the boom hydraulic cylinder 15 at the first future time that satisfies the prescribed condition based on each of the prediction values (operation results) of the speed and posture prediction section 915. Figure 9 The step S90) shown, and outputs the target speed of the boom hydraulic cylinder 15 at the first future time as the speed command of the current time (current operation period) (S91) of the operation section 920. Figure 10 The step S120) shown. In this case, the command of the forced operation of the boom hydraulic cylinder 15 that includes the influence of the actual operation (actual speed) of the hydraulic actuators 15 to 17 is generated.

[0120] As described above, in the third period S3, the operation of each of the hydraulic actuators 15 to 17 at the first future time is predicted based on the speed (actual speed) of each of the hydraulic actuators 15 to 17 at the current time (current operation period) and the past history of the speed command of the stick hydraulic cylinder 16, and thus the speed command of the boom hydraulic cylinder 15 at the current time (current operation period) that takes into account the response delay of the actual speed of each of the hydraulic actuators 15 to 17 with respect to the speed command can be output. That is, in the case where the second operation device 52 is operated and the stick hydraulic cylinder 16 is in the actual operation, by outputting in advance the speed command of the boom hydraulic cylinder 15 corresponding to the predicted operation of the stick hydraulic cylinder 16, the execution of the MC that takes into account the response delay of each of the hydraulic actuators 15 to 17 can be realized.

[0121] As described above, in the third period S3, the operation of each of the hydraulic actuators 15 to 17 at the first future time is predicted based on the speed (actual speed) of each of the hydraulic actuators 15 to 17 at the current time (current operation period) and the past history of the speed command of the stick hydraulic cylinder 16, and thus the speed command of the boom hydraulic cylinder 15 at the current time (current operation period) that takes into account the response delay of the actual speed of each of the hydraulic actuators 15 to 17 with respect to the speed command can be output. That is, in the case where the second operation device 52 is operated and the stick hydraulic cylinder 16 is in the actual operation, by outputting in advance the speed command of the boom hydraulic cylinder 15 corresponding to the predicted operation of the stick hydraulic cylinder 16, the execution of the MC that takes into account the response delay of each of the hydraulic actuators 15 to 17 can be realized.

[0122] The hydraulic excavator (work machine) of the first embodiment of the present application described above is provided with: a front work implement 1 (work implement) that performs a work; boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators) that drive the front work implement 1 (work implement); a hydraulic pump 42 that supplies hydraulic oil to the boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators); first to third flow control valves 45, 46, and 47 (a plurality of control valves) that respectively control the flow of the hydraulic oil supplied from the hydraulic pump 42 to each of the boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators); a posture detection device 30 that detects the posture of the front work implement 1 (work implement); and a controller 80 that calculates the speed command of each of the boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators) at each calculation cycle, and outputs a control signal for controlling each of the boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators) based on the speed command of each of the boom hydraulic cylinders 15, arm hydraulic cylinders 16, and bucket hydraulic cylinders 17 (a plurality of hydraulic actuators) calculated as a result of the calculation. In a case where the operation of the boom hydraulic cylinders 15 (first hydraulic actuators) is controlled under a predetermined condition in accordance with the operation of the arm hydraulic cylinders 16 (second hydraulic actuators) among the plurality of hydraulic actuators 15, 16, and 17, the controller 80 calculates the actual speed of each of the plurality of hydraulic actuators in the current calculation cycle based on the detection signal of the posture detection device 30, calculates the speed command of the boom hydraulic cylinders 15 (first hydraulic actuators) in the current calculation cycle that satisfies the condition using the actual speed of each of the plurality of hydraulic actuators 15, 16, and 17 calculated as a result of the calculation, and the past history of the speed command of each of the plurality of hydraulic actuators 15, 16, and 17 calculated in a calculation cycle that is past compared to the current calculation cycle, and outputs a control signal for controlling the boom hydraulic cylinders 15 (first hydraulic actuators) based on the speed command of the boom hydraulic cylinders 15 (first hydraulic actuators) in the current calculation cycle calculated as a result of the calculation.

[0123] According to this configuration, since the speed command of the boom hydraulic cylinder 15 (first hydraulic actuator) in the current calculation cycle that satisfies the prescribed condition is calculated using the actual speed of each hydraulic actuator 15, 16, 17 in the current calculation cycle calculated based on the detection signal of the posture detection device 30 and the past history of the speed command of each hydraulic actuator 15, 16, 17 calculated in the past calculation cycle compared to the current calculation cycle, the speed command of the boom hydraulic cylinder 15 (first hydraulic actuator) in the current calculation cycle that takes into account the response delay of the actual speed with respect to the speed command can be calculated. Therefore, the motion accuracy of the front working device 1 (working device) in the MC can be improved while reducing the influence of the response delay of the actual speed of the hydraulic actuators 15, 16, 17 with respect to the speed command.

[0124] In addition, the controller 80 of the present embodiment is configured to calculate the predicted value of the speed of each of the plurality of hydraulic actuators 15, 16, 17, the predicted value of the posture of the front working device 1 (working device), and the predicted value of the position of the control point of the front working device 1 (working device) with respect to the target surface after the first time T1 from the current calculation cycle, using the actual speed of each of the plurality of hydraulic actuators 15, 16, 17 in the current calculation cycle obtained based on the detection signal of the posture detection device 30 and the past history of the speed command of each of the plurality of hydraulic actuators 15, 16, 17 calculated in the period from the past calculation cycle before the first time T1 compared to the current calculation cycle to the current calculation cycle, calculate the target speed of the first hydraulic actuator that makes the control point of the front working device 1 (working device) be on the target surface after the first time T1 from the current calculation cycle as the speed command of the boom hydraulic cylinder 15 (first hydraulic actuator) in the current calculation cycle based on the calculation results of the predicted value of the speed, the predicted value of the posture, and the predicted value of the position, and output a control signal for controlling the boom hydraulic cylinder 15 (first hydraulic actuator) based on the speed command of the boom hydraulic cylinder 15 (first hydraulic actuator) in the current calculation cycle of the boom hydraulic cylinder 15 (first hydraulic actuator) based on the calculation results.

[0125] According to this configuration, since the various predicted values after the first time Tl from the current calculation cycle are calculated using the past history of the speed command of each hydraulic actuator 15, 16, 17 calculated in the period from the past calculation cycle before the first time Tl compared with the current calculation cycle to the current calculation cycle, by setting the first time Tl to be substantially in accordance with the time of the response delay of the actual speed of each hydraulic actuator 15, 16, 17 with respect to the speed command, the various predicted values considering the response delay of the actual speed with respect to the speed command can be obtained. Also, based on the various predicted values considering the response delay of the actual speed with respect to the speed command, the target speed of the boom hydraulic cylinder 15 (first hydraulic actuator) such that the control point of the front working device 1 (working device) is located on the target surface after the first time Tl from the current calculation cycle is calculated as the speed command of the current calculation cycle, and thus the speed command of the boom hydraulic cylinder 15 (first hydraulic actuator) satisfying the prescribed condition can be obtained while the response delay of the actual speed with respect to the speed command is considered. Thus, the influence of the response delay of the actual speed of each hydraulic actuator 15, 16, 17 with respect to the speed command in the MC can be reduced, and thus the operation accuracy of the front working device 1 (working device) is improved, and the control point of the front working device 1 (working device) can be moved along the target surface.

[0126] [Second Embodiment]

[0127] Next, the second embodiment of the work machine of the present application will be described. Figure 10 The second embodiment of the work machine of the present application will be described. Figure 9 is a block diagram showing the function of the MC calculation section of the controller constituting the second embodiment of the work machine of the present application. Figure 10 is a flowchart showing an example of the processing steps of the calculation in the speed and posture prediction section and the speed command calculation section of the controller shown in Figure 10 Figure 6 is an explanatory diagram showing the calculation method of the speed and posture prediction section and the speed command calculation section of the controller shown in Figure 6 Figure 9 is an explanatory diagram showing the relationship between the target speed, the speed command, and the actual speed of each hydraulic actuator when the MC is executed with respect to the bucket lever recovery operation in the second embodiment of the work machine of the present application. Note that in Figure 10 , the same reference numerals as those shown in Figure 10 are attached to the same parts, and thus the detailed description thereof is omitted.

[0128] Figure 10 ​​The second embodiment of the work machine of the present application shown differs from the first embodiment in that the operation method of the speed and posture prediction section 915A and the speed command operation section 916A in the MC operation section 91A of the controller 80A is different. The speed and posture prediction section 915 and the speed command operation section 916 in the MC operation section 91 of the controller 80 of the first embodiment operate on the premise that the time of response delay of the actual speed of each hydraulic actuator 15 to 17 with respect to the speed command is approximately the first time Tl. In contrast, the speed and posture prediction section 915A and the speed command operation section 916A of the present embodiment operate on the premise that the time of response delay of the actual speed of the boom hydraulic cylinder 15 with respect to the speed command is approximately the second time T2, and the time of response delay of the actual speed of the stick hydraulic cylinder 16 with respect to the speed command is approximately the third time T3. However, the present embodiment is applied only in the case where the third time T3 is longer than the second time T2.

[0129] The speed and posture prediction section 915A of the present embodiment operates on the predicted values of the speed of each hydraulic actuator 15 to 17 of the front work device 1, and the predicted values of the posture of the front work device 1 and the position of the control point with respect to the target surface at a future time (hereinafter sometimes referred to as a second future time) after the second time T2 from the current time (current operation cycle). Specifically, based on the posture of the front work device 1 and the position of the control point at the current time (current operation cycle) as the operation result of the posture operation section 912, the position information of the target surface as the operation result of the target surface operation section 913, the past history of the speed command of the boom hydraulic cylinder 15 output from the speed command operation section 916A in the period from a past time (hereinafter sometimes referred to as a second past time) that is the second time T2 before the current time (current operation cycle) to the current time (current operation cycle), and the past history of the speed command of the stick hydraulic cylinder 16 and the bucket hydraulic cylinder 17 (hydraulic actuators of the front work device 1 other than the boom hydraulic cylinder 15) output from the speed command operation section 916A in the period from a past time (hereinafter sometimes referred to as a third past time) that is the third time T3 before the current time (current operation cycle) to a past time that is the second time T2 after the third past time, the above-mentioned predicted values at the second future time are operated. The detailed operation method of the speed and posture prediction section 915A will be described later.

[0130] If the MC determination unit 911 determines that the MC is valid, the speed command calculation unit 916A calculates the target speed of the boom hydraulic cylinder 15 (boom 11) required at the second future time, after a second time T2 compared to the current time (current calculation cycle), such that the control point (e.g., the tip of the bucket 13 tooth) of the front working device 1 is located on the target surface. Additionally, it calculates the target speeds of the stick hydraulic cylinder 16 (stick 12) and the bucket hydraulic cylinder 17 (bucket 13) at the third future time (hereinafter sometimes referred to as the third future time), after a third time T3 compared to the current time (current calculation cycle). Specifically, the speed command calculation unit 916A calculates the target speed of the boom hydraulic cylinder 15 at the second future time, based on the predicted speeds of each hydraulic actuator 15-17, the predicted posture of the front working device 1, and the predicted position of the control point relative to the target surface, which are the calculation results of the speed and posture prediction unit 915A. Furthermore, based on the operation quantities of the operation devices 52 and 53, which are the detection results of the operation quantity detection device 78, the target speeds of the boom hydraulic cylinder 16 and the bucket hydraulic cylinder 17 at the third future moment are calculated. The speed command calculation unit 916A outputs the target speeds of each hydraulic actuator 15 to 17, which are the calculation results, as the speed command for the current moment (current calculation cycle).

[0131] Next, use Figure 10 and Figure 9 An example of the calculation method of the speed and posture prediction unit and the speed command calculation unit of the controller in the second embodiment of the working machine of the present invention will be described in detail. Figure 9 The flowchart shown represents one computation cycle. Figure 9 In the diagram, the upper image shows information related to the speed of the stick hydraulic cylinder, and the lower image shows information related to the speed of the boom hydraulic cylinder. Additionally, solid lines represent the actual speed of the hydraulic actuator, dashed lines represent the speed command of the hydraulic actuator, and single-dot lines represent the predicted speed of the hydraulic actuator.

[0132] Figure 10 The velocity and attitude prediction unit 915A shown firstly determines the execution of MC (MC) based on the determination result (valid or invalid) of MC determination unit 911, similar to the case in the first embodiment. Figure 9 The flowchart shown includes steps S10 to S20. If the determination in step S20 is yes, the processing of steps S30 to S120, including steps S60A to S90A, is performed; on the other hand, if the determination in step S20 is no, the processing of steps S200 to S220, which are the same as in the first embodiment, is performed.

[0133] If the determination is yes in step S20, similarly to the case in the first embodiment, the velocity and attitude prediction unit 915A obtains the position information of the target surface from the target surface calculation unit 913. Figure 9 (See step S30). Furthermore, the posture of the front working device 1 and the position of the control point at the current moment are obtained from the posture calculation unit 912, and the actual speed of each hydraulic actuator 15-17 at the current moment (current calculation cycle) is calculated based on the obtained information. Figure 9 The steps S40 to S50 shown are used to calculate the actual speed. Figure 10 The black dot in the above image represents the current time (current computation cycle). However, in Figure 11 Only the case of boom hydraulic cylinder 16 is shown in the image.

[0134] Next, the speed and attitude prediction unit 915A calculates the history of the predicted speeds of each hydraulic actuator 15 to 17 from the current time (current calculation cycle) to a future time after the second time T2 (second future time). Figure 11 (See step S60A). Specifically, the past history of the speed command of the boom hydraulic cylinder 16 calculated and output by the speed command calculation unit 916A during the period from a past time (third past time) before the current time (current calculation cycle) to the past current time (past calculation cycle) after the second time T2 is transferred relative to the speed (actual speed) of the boom hydraulic cylinder 16 at the current time calculated in step S50, and the speed command of the boom hydraulic cylinder 16 output by the speed command calculation unit 916A at the third past time is made consistent with the speed (actual speed) of the boom hydraulic cylinder 16 at the current time calculated in step S50. The past history of the transferred speed command of the boom hydraulic cylinder 16 is regarded as the history of the predicted value of the speed of the boom hydraulic cylinder 16 from the current time to the second future time. That is, based on the current speed (actual speed) of the boom hydraulic cylinder 16, and based on the past history of the speed commands of the boom hydraulic cylinder 16 output from the speed command calculation unit 916A during the period from the third past time to the past time after the second time T2, the future history of the speed of the boom hydraulic cylinder 16 during the time interval from the current time to the second future time is predicted.

[0135] This operation is equivalent to Figure 11 The I (transfer) portion shown. That is, in Figure 9In the diagram above, the dashed line (speed commands of each hydraulic actuator 15 to 17) from the third past time (t0-T3) to the past time (t0-T3+T2) after the second time T2 is transferred in such a way that the black dot of the speed command at the third past time (t0-T3) is consistent with the black dot of the actual speed at the current time (t0). This generates a single-dot line (predicted speed value of each hydraulic actuator 15 to 17) from the current time (t0) to the second future time (t0+T2).

[0136] It should be noted that the calculation of the predicted speed of the boom hydraulic cylinder 15 is similar to the calculation method in the first embodiment, except that the set time is changed from the first time T1 to the second time T2. That is, based on the current speed (actual speed) of the boom hydraulic cylinder 15, the future speed of the boom hydraulic cylinder 15 within the time interval from the current time to the second future time is predicted based on the past history of the speed commands of the boom hydraulic cylinder 15 output from the speed command calculation unit 916A during the period from the second time T2 before the current time (current calculation cycle) to the current time (current calculation cycle). Figure 9 Then Figure 9 The first time T1 is changed to the second time T2. That is, based on the current time (current calculation cycle) t0, the first future time (t0+T1) is changed to the second future time (t0+T2), and the first past time (t0-T1) is changed to the second past time (t0-T2). This takes into account that the speed command of the boom hydraulic cylinder 15 is achieved with a response delay of approximately the second time T2, and the speed command of the stick hydraulic cylinder 16 is achieved with a response delay of approximately the third time T3.

[0137] Next, the speed and attitude prediction unit 915A predicts the extension and retraction lengths of each hydraulic actuator 15 to 17 during the period from the current moment to the second future moment. Figure 11 (See step S70A). Specifically, the history of the predicted speeds of each hydraulic actuator 15 to 17 calculated in step S60A during the period from the current time to the second future time is integrated over the time interval from the current time to the second future time, thereby predicting the extension length of each hydraulic actuator 15 to 17 generated during the period from the current time to the second future time.

[0138] This prediction operation is equivalent to Figure 9 The portion II (integral = stretching length) shown. That is, in Figure 11In the above figure, the area of ​​the diagonal line segment enclosed by the time interval from the current time (t0) to the second future time (t0+T2) and the single-dotted line (the history of the predicted speed values ​​of each hydraulic actuator 15-17) corresponds to the predicted extension length of each hydraulic actuator 15-17. However, in Figure 9 Only the case of the boom hydraulic cylinder 16 is shown. That is to say, the predicted extension lengths of the boom hydraulic cylinder 15 and the bucket hydraulic cylinder 17 are also compared with... Figure 11 The operation equivalent to II (integral = stretch length) shown is shown.

[0139] Furthermore, the speed and attitude prediction unit 915A predicts the attitude of the front working device 1 and the position of the control point relative to the target surface at a second future moment. Figure 12-15 (See step S80A). Specifically, based on the current posture (posture of boom 11, stick 12, and bucket 13) and control point position of the front working device 1 obtained in step S40, the predicted extension length of each hydraulic actuator 15-17 at the second future time calculated in step S70A, and the target surface position information obtained in step S30, the posture of the front working device 1 and the position of the control point relative to the target surface (e.g., the distance from the control point to the target surface) at the second future time are calculated. The speed and posture prediction unit 915A outputs the posture of the front working device 1 and the position of the control point relative to the target surface at the second future time, which is the result of the calculation in step S80A, and the predicted speed of each hydraulic actuator 15-17 at the second future time, which is the result of the calculation in step S60A, to the speed command calculation unit 916A.

[0140] Next, the speed command calculation unit 916A calculates the target speed of the boom hydraulic cylinder 15 required to meet the specified conditions at the second future time. Figure 12 (See step S90A). Specifically, based on the predicted values ​​of the posture of the front working device 1 at the second future time calculated in step S80A, the predicted values ​​of the position of the control point relative to the target surface, and the predicted values ​​of the speeds of each hydraulic actuator 15 to 17 at the second future time calculated in step S60A, the speed of the boom hydraulic cylinder 15, which enables the control point of the front working device 1 to be located on the target surface at the second future time, is calculated as the target speed at the second future time.

[0141] Figure 12 The operations shown in steps S60A to S90A are equivalent to starting from... Figure 12The portion shown by the arrow from I (transferred) via II (integral = extension length) to III (target speed at future time) is a portion in which the operation is performed based on the operation of the operation device 52, 53. This operation is a portion in which the command of the forced operation of the boom hydraulic cylinder 15 based on the activation of the MC that is independent of the operation of the operation device 51 is calculated based on the operation of at least one of the arm hydraulic cylinder 16 and the bucket hydraulic cylinder 17.

[0142] Further, the speed command operation portion 916A, as with the case of the first embodiment, acquires the pilot pressure (P2) as the operation amount of the second operation device 52 from the operation amount operation portion 914 (step S100 shown by the arrow), and calculates the target speed of the arm hydraulic cylinder 16 at the third future time based on the acquired pilot pressure (step S110 shown by the arrow). Figure 1-11 The target speed of the arm hydraulic cylinder 16 at the third future time is calculated based on the operation of the second operation device 52. Figure 12 The target speed of the bucket hydraulic cylinder 17 at the third future time is also calculated in the case where the third operation device 53 is also operated.

[0143] Finally, the speed command operation portion 916A outputs the target speed of the boom hydraulic cylinder 15 at the second future time calculated in step S90A as the speed command at the current time (current operation cycle) of the boom hydraulic cylinder 15, and outputs the target speed of the arm hydraulic cylinder 16 calculated in step S110 as the speed command at the current time of the arm hydraulic cylinder 16 (step S120 shown by the arrow). Figure 13 The relationship between the target speed of the boom hydraulic cylinder 15 and the speed command in this step S120 corresponds to the portion of the white arrow from the black dot of III (target speed at future time) toward the black dot of IV (output of speed command at current time) shown by the arrow. Figure 13 This takes into account the case where the actual speed of the boom hydraulic cylinder 15 is reached with a response delay of the second time T2 after the output of the speed command of the boom hydraulic cylinder 15. With the end of step S120, the current operation cycle ends, and the process returns to the start to start the next operation cycle.

[0144] Next, the operation of the second embodiment of the working machine of the present application will be described. Figure 12 The operation of the second embodiment of the working machine of the present application will be described. In the second embodiment, the operation of the second operation device 52 is used for the arm operation. Figure 14 In the second embodiment, the operation of the second operation device 52 is used for the arm operation. In the second embodiment, the operation of the second operation device 52 is used for the arm operation.

[0145] In the second embodiment, the operation of the second operation device 52 is used for the arm operation. In the second embodiment, the operation of the second operation device 52 is used for the arm operation. Figure 14In this context, the first period S1 is the period during which the operator does not operate the second operating device 52. The second period S2 is the period during which, although the second operating device 52 is operated, the stick hydraulic cylinder is not activated due to the response delay of the second operating device 52. It should be noted that period S2(a) in the second period S2 is a period during which, due to the difference between the response delay time of the boom hydraulic cylinder 15 (approximately the second time T2) and the response delay time of the stick hydraulic cylinder 16 (approximately the third time T3), the speed command of the boom hydraulic cylinder 15 is 0 even if a speed command (not a 0 value) is output for the stick hydraulic cylinder 16. On the other hand, period S2(b) in the second period S2 is a period during which a speed command (not a 0 value) for the boom hydraulic cylinder 15 is output in response to the output of the speed command for the stick hydraulic cylinder 16. The third period S3 is the period during which the stick hydraulic cylinder 16 is activated by the operation of the second operating device 52. Regarding the first period S1, since it is the same as in the first embodiment, its description is omitted.

[0146] During the second period S2, the stick retraction operation of the second operating device 52 is input. Consequently, the speed command calculation unit 916A calculates the target speed of the stick hydraulic cylinder 16 after the third time T3 based on the stick retraction pilot pressure corresponding to the detection signal from the operation amount detection device 78. Figure 12 (Steps S100 to S110 are shown). Furthermore, the speed and posture prediction unit 915A calculates the predicted values ​​of the posture of the front working device 1 and the position of the control point relative to the target surface, as well as the predicted values ​​of the speeds of each hydraulic actuator 15 to 17, based on the past history of speed commands output by each hydraulic actuator 15 to 17 in the second future time. Figure 15 Steps S60A to S80A are shown. The speed command calculation unit 916A calculates the target speed of the boom hydraulic cylinder 15 at a second future moment that satisfies predetermined conditions, based on the predicted values ​​obtained from the calculation results of the speed and posture prediction unit 915A. Figure 15 (Step S90A shown).

[0147] In the present embodiment, since the second time T2 that is substantially in agreement with the response delay time of the boom hydraulic cylinder 15 is shorter than the third time T3 that is substantially in agreement with the response delay time of the arm hydraulic cylinder 16, in a period S2(a) in the second period S2 that corresponds to the difference between the third time T3 and the second time T2, the operation result of the target speed of the boom hydraulic cylinder 15 at the second future time after the second time T2 is 0. The speed command operation portion 916A outputs the target speed (value of 0) of the boom hydraulic cylinder 15 after the second time T2 (second future time) as the speed command of the boom hydraulic cylinder 15 that should be output at the current time to the actuator control portion 917, and outputs the target speed (value corresponding to the operation amount of the operation device 52) of the arm hydraulic cylinder 16 after the third time T3 as the speed command of the boom hydraulic cylinder 15 to the actuator control portion 917. Therefore, as shown in FIG. 9, in the period S2(a), the speed command of the arm hydraulic cylinder 16 is output in correspondence with the operation of the operation device 52, and on the other hand, the speed command of the boom hydraulic cylinder 15 is 0. Figure 15

[0148] In the period S2(b) in the second period, as in the period S2(a), the speed command operation portion 916A operates the target speed of the boom hydraulic cylinder 15 at the second future time after the second time T2 that satisfies the prescribed condition (step S90A shown in FIG. 9) based on each of the predicted values at the second future time after the second time T2 as the operation result of the posture prediction portion 915A. In the period S2(b), since a time has passed after the output of the speed command of the arm hydraulic cylinder 16 in correspondence with the operation of the operation device 52, a value other than 0 is operated as the target speed of the boom hydraulic cylinder 15 at the second future time after the second time T2. The speed command operation portion 916A outputs the target speed (value other than 0) of the boom hydraulic cylinder 15 after the second time T2 (second future time) as the speed command of the boom hydraulic cylinder 15 that should be output at the current time, and outputs the target speed (value corresponding to the operation amount of the operation device 52) of the arm hydraulic cylinder 16 after the third time T3 as the speed command of the boom hydraulic cylinder 15. Therefore, as shown in FIG. 9, in the period S2(b), the speed command of the arm hydraulic cylinder 16 is output in correspondence with the operation of the operation device 52, and the speed command of the boom hydraulic cylinder 15 corresponds to the predicted action that takes into account the response delay time (second time T2) of the boom hydraulic cylinder 15 itself and also takes into account the response delay time (third time T3) of the arm hydraulic cylinder 16 with respect to the speed command. Figure 15 Figure 15

[0149] ​​​During the third period S3, the boom hydraulic cylinder 16 and the boom hydraulic cylinder 15 operate in response to the output of the speed command. In this case, the speed command calculation unit 916A calculates the target speed of the boom hydraulic cylinder 15 at the second future time after the second time T2, based on the predicted values ​​of each hydraulic actuator 15-17 after the second time T2, which also take into account the speed of each actuator 15-17 at the current time, as the result of the calculation by the speed and posture prediction unit 915A. Figure 15 (as shown in step S90A). Therefore, in the third period S3, as... Figure 15 As shown, similar to the case in period S2(b), the speed command of the boom hydraulic cylinder 16 is output in response to the operation of the operating device 52, and the speed command of the boom hydraulic cylinder 15 corresponds to a predicted action that takes into account both its own response delay time (second time T2) and the response delay time of the boom hydraulic cylinder 16 relative to the speed command (third time T3).

[0150] Thus, in this embodiment, even if the response delay time of the boom hydraulic cylinder 15 differs from that of the stick hydraulic cylinder 16, if the second time T2 corresponding to the response delay time of the boom hydraulic cylinder 15 is shorter than the third time T3 corresponding to the response delay time of the stick hydraulic cylinder 16 (second time T2 < third time T3), then speed commands for the hydraulic actuators 15-17 that take into account the response delay time can still be output. Therefore, the impact of the response delay of the actual speed of the hydraulic actuators 15-17 relative to the target speed can be reduced.

[0151] The controller 80A of the second embodiment of the work machine of the present application described above is configured to calculate a predicted value of the speed of each of the plurality of hydraulic actuators 15, 16, 17, a predicted value of the posture of the working device, and a predicted value of the position of the control point of the front working device 1 (working device) with respect to the target surface, from the actual speed of each of the plurality of hydraulic actuators 15, 16, 17 for the current calculation cycle obtained based on the detection signal of the posture detection device 30, the past history of the speed command of the boom cylinder 15 (first hydraulic actuator) calculated over the period from the past calculation cycle before the prescribed second time T2 compared to the current calculation cycle to the current calculation cycle, and the past history of the speed command of each of the hydraulic actuators 16, 17 other than the boom cylinder 15 (first hydraulic actuator) calculated over the period from the past calculation cycle before the prescribed third time T3 which is a longer time than the second time T2 compared to the current calculation cycle to the past calculation cycle after the second time T2, using the predicted values as the basis, calculate the target speed of the boom cylinder 15 (first hydraulic actuator) that will bring the control point of the front working device 1 (working device) onto the target surface after the second time T2 from the current calculation cycle as the speed command of the boom cylinder 15 (first hydraulic actuator) for the current calculation cycle of the boom cylinder 15 (first hydraulic actuator) based on the calculation results of the predicted values of the speed, the predicted value of the posture, and the predicted value of the position, and output a control signal for controlling the boom cylinder 15 (first hydraulic actuator) based on the speed command of the boom cylinder 15 (first hydraulic actuator) for the current calculation cycle of the boom cylinder 15 (first hydraulic actuator) based on the calculation results.

[0152] According to this structure, since the past history of the speed command of the boom cylinder 15 (first hydraulic actuator) calculated in the period from the past operation cycle before the second time T2 compared to the current operation cycle to the current operation cycle, and the past history of the speed command of the stick cylinder 16 and the bucket cylinder 17 (other than the boom cylinder 15) calculated in the period from the past operation cycle before the third time T3 compared to the current operation cycle to the past operation cycle after the second time T2 are used to calculate the various predicted values after the second time T2 from the current operation cycle, even in the case where the response delay times of the actual speeds of the boom cylinder 15 (first hydraulic actuator) and the stick cylinder 16 (second hydraulic actuator) with respect to the speed commands are different, by setting the second time T2 to be substantially in agreement with the response delay time of the boom cylinder 15 (first hydraulic actuator) and setting the third time T3 to be substantially in agreement with the response delay time of the stick cylinder 16 (second hydraulic actuator), it is also possible to obtain the various predicted values that take into account the different response delays of the hydraulic actuators 15, 16, 17. Moreover, based on the various predicted values that take into account the different response delays of the hydraulic actuators 15, 16, 17, the target speed of the boom cylinder 15 (first hydraulic actuator) that makes the control point of the front working device 1 (working device) be located on the target surface after the second time T2 from the current operation cycle is calculated as the speed command of the current operation cycle, and thus it is possible to obtain the speed command of the boom cylinder 15 (first hydraulic actuator) that satisfies the prescribed condition while taking into account the response delay of the boom cylinder 15 (first hydraulic actuator). Thus, it is possible to reduce the influence of the different response delays of the hydraulic actuators 15, 16, 17 in the MC, and thus the operation accuracy of the front working device 1 (working device) is improved, and it is possible to move the control point of the front working device 1 (working device) along the target surface.

[0153] [Third Embodiment]

[0154] Next, the function structure of the MC operation unit of the controller in the third embodiment of the work machine of the present application will be described. ​ The third embodiment of the work machine of the present application will be described. First, the function structure of the MC operation unit of the controller in the third embodiment of the work machine of the present application will be described. ​ The function structure of the MC operation unit of the controller in the third embodiment of the work machine of the present application will be described. ​ is a block diagram showing the function of the MC operation unit of the controller that constitutes a part of the third embodiment of the work machine of the present application. Note that in ​ , the same parts as those shown by the reference numerals in ​ are denoted by the same reference numerals, and thus detailed description thereof will be omitted.

[0155] ​The third embodiment of the work machine of the present application shown differs from the second embodiment in the timing of output of the command corresponding to the operation results of the actuator control section 917B and the hydraulic pump control section 918B of the controller 80B. The actuator control section 917 and the hydraulic pump control section 918 of the controller 80 of the first embodiment respectively output, as the pilot pressure command of the flow control valves 45 to 47 and the pump volume command of the hydraulic pump 42 for the flow control valves 45 to 47 for the current time (the current operation cycle), the target pilot pressure of the flow control valves 45 to 47 and the target pump volume of the hydraulic pump 42 as the operation results of the flow control valves 45 to 47 for the current operation cycle. In contrast, the actuator control section 917B and the hydraulic pump control section 918B of the controller 80B of the present embodiment respectively take into account the time of response delay of the actual pilot pressure of the flow control valves 45 to 47 with respect to the pilot pressure command and the time of response delay of the actual volume of the hydraulic pump 42 with respect to the pump volume command, and output, as the pilot pressure command of the flow control valves 45 to 47 and the pump volume command of the hydraulic pump 42, the target pilot pressure of the flow control valves 45 to 47 and the target pump volume of the hydraulic pump 42 for the current operation cycle, which are delayed.

[0156] Specifically, the actuator control section 917B sets the delay time based on the fourth time T4 that is substantially identical to the response delay time of the actual pilot pressure of the flow control valves 45 to 47 with respect to the pilot pressure command, and outputs, as the pilot pressure command, the target pilot pressure of the flow control valves 45 to 47 as the operation result for the current operation cycle after the delay time. That is, the target pilot pressure of the flow control valves 45 to 47 calculated in the past operation cycle that is the delay time before the current operation cycle is output as the pilot pressure command for the current time (the current operation cycle). The delay time is, for example, the time (T3-T4) obtained by subtracting the fourth time T4 from the third time T3 that is substantially identical to the response delay time of the actual speed of the boom hydraulic cylinder 16 with respect to the speed command. However, the present embodiment can be applied only in the case where the fourth time T4 is shorter than the third time T3.

[0157] Further, the hydraulic pump control section 918B sets a delay time based on the fifth time T5 which is substantially identical to the response delay time of the actual displacement of the hydraulic pump 42 with respect to the pump displacement command, and outputs the target pump displacement of the hydraulic pump 42 as the operation result of each operation cycle as the pump displacement command to the regulator control section 94 after the delay time. That is, the target pump displacement of the hydraulic pump 42 calculated in the past operation cycle before the delay time compared to the current operation cycle is output as the pump displacement command at the current time (current operation cycle). The delay time is, for example, a time (T3-T5) obtained by subtracting the fifth time T5 from the third time T3. However, this embodiment can be applied only in the case where the fifth time T5 is shorter than the third time T3.

[0158] Next, using ​ An example of the processing steps of the operation in the actuator control section of the controller of the third embodiment will be described. ​ is a flowchart showing an example of the processing steps of the operation in the actuator control section of the controller. ​ is a flowchart showing an example of the processing steps of the operation in the actuator control section of the controller.

[0159] The actuator control section 917B first sets a delay time of the output of the pilot pressure command (step S310). Specifically, the delay time is, as described above, a time (T3-T4) obtained by subtracting the fourth time T4 from the third time T3. Next, the speed command of each hydraulic actuator 15 to 17 as the operation result of the speed command operation section 916A is acquired (step S320), and the target pilot pressure of the flow control valve 45 to 47 corresponding to each hydraulic actuator 15 to 17 is operated based on the acquired speed command of each hydraulic actuator 15 to 17 (step S330). Thereafter, the target pilot pressure calculated in the past operation cycle corresponding to the delay time (T3-T4) set by the step S310 is output as the pilot pressure command at the current time to the electromagnetic proportional valve control section 93 (step S340). If the processing of the step S340 is ended, the processing of the steps S320 to S340 is performed again (next operation cycle).

[0160] Next, using ​ An example of the processing steps of the operation in the hydraulic pump control section of the controller of the third embodiment will be described. ​ is a flowchart showing an example of the processing steps of the operation in the hydraulic pump control section of the controller. ​ is a flowchart showing an example of the processing steps of the operation in the hydraulic pump control section of the controller.

[0161] The hydraulic pump control section 918B first sets a delay time of the output of the pump displacement command (step S410). Specifically, the delay time is a time (T3-T5) obtained by subtracting the fifth time T5 from the third time T3 as described above. Next, the speed commands of the hydraulic actuators 15 to 17 that are the operation results of the speed command operation section 916A are acquired (step S420), and the target pump displacement of the hydraulic pump 42 is operated based on the acquired speed commands of the hydraulic actuators 15 to 17 (step S430). Thereafter, the target pump displacement operated in the past operation period corresponding to the delay time (T3-T5) set by step S410 is outputted as the pump displacement command of the current time to the regulator control section 94 (step S440). If the processing of step S440 ends, the processing of steps S420 to S440 is performed again (next operation period).

[0162] Next, the pump displacement of the hydraulic pump 42 is operated based on the target pilot pressure of the flow control valve 40 (step S430). The pump displacement of the hydraulic pump 42 is outputted as the pump displacement command of the current time to the regulator control section 94 (step S440). If the processing of step S440 ends, the processing of steps S420 to S440 is performed again (next operation period). ​ The operation and effects of the third embodiment of the working machine of the present application will be described. ​ is an explanatory view showing the relationship of the pilot pressure information of the control valve and the pump displacement information of the hydraulic pump with respect to the speed information of the hydraulic actuator at the time of executing MC in the third embodiment of the working machine of the present application. In ​ , the upper layer view shows the time history of the target speed, the speed command, and the actual speed of the hydraulic actuator, the middle layer view shows the time history of the target pilot pressure and the pilot pressure command of the flow control valve, and the lower layer view shows the time history of the target pump displacement and the pump displacement command of the hydraulic pump. Here, as in the case of the second embodiment, the case where the horizontal digging operation based on MC is performed by the bucket lever retracting operation of the second operation device 52 for the bucket lever operation inputted by the operator will be described.

[0163] In ​ , when the bucket lever retracting operation is inputted, the speed command operation section 916A operates the target speed of the bucket hydraulic cylinder 16 after the third time T3 based on the operation, and outputs the target speed as the speed command of the current time (current operation period).

[0164] The actuator control section 917B operates the target pilot pressure based on the speed command of the current time (current operation period) that is the output of the speed command operation section 916A, and outputs the target pilot pressure of the operation result as the pilot pressure command from the current time (current operation period) with a delay of the delay time (third time T3-fourth time T4) set by S310. That is, as ​As shown, the pilot pressure command of the actuator control section 917B is output with a delay time (third time T3 - fourth time T4) from the output of the speed command of the speed command calculation section 916A, which is the basis of the calculation of the pilot pressure command. At this time, the actual pilot pressure input to each of the flow control valves 45 to 47 varies according to the pilot pressure command, but is substantially uniform with a delay time of the fourth time T4 from the output of the pilot pressure command.

[0165] In addition, the hydraulic pump control section 918B calculates the target pump displacement based on the speed command of the current time (current calculation cycle) as the output of the speed command calculation section 916A, and outputs the calculated target pump displacement as the pump displacement command from the current time (current calculation cycle) with a delay time (third time T3 - fifth time T5) set by S410. That is, as shown in ​ As shown, the pump displacement command of the hydraulic pump control section 918B is output with a delay time (third time T3 - fifth time T5) from the output of the speed command of the speed command calculation section 916A, which is the basis of the calculation of the pump displacement command. At this time, the actual pump displacement of the hydraulic pump 42 varies according to the pump displacement command, but is substantially uniform with a delay time of the fifth time T5 from the output of the pump displacement command.

[0166] Thus, in the present embodiment, even in the case where the response delay time of the actual pilot pressure of the flow control valves 45 to 47 with respect to the pilot pressure command is different from the response delay time of the actual pump displacement of the hydraulic pump 42 with respect to the pump displacement command, if the fourth time T4 corresponding to the response delay time of the flow control valves 45 to 47 is shorter than the third time T3 corresponding to the response delay time of the boom hydraulic cylinder 16, and the fifth time T5 corresponding to the response delay time of the hydraulic pump 42 is shorter than the third time T3 corresponding to the response delay time of the boom hydraulic cylinder 16 (fourth time T4 < third time T3 and fifth time T5 < third time T3), the pilot pressure command of the flow control valves 45 to 47 and the pump displacement command of the hydraulic pump 42 that take the response delay into account can be output. Therefore, as shown in the upper graph of ​ the influence of the response delay of the actual speed of the boom hydraulic cylinder 16 with respect to the speed command can be reduced.

[0167] In the third embodiment of the work machine of the present application described above, the plurality of flow control valves 45, 46, 47 (control valves) are each a hydraulic pilot type driven by the action of a pilot pressure. In addition, the controller 80B is configured to calculate a target pilot pressure for driving the flow control valves 45, 46, 47 (control valves) corresponding to the plurality of hydraulic actuators 15, 16, 17, respectively, in response to the speed commands of the plurality of hydraulic actuators 15, 16, 17, and output the target pilot pressure of the calculation result as a pilot pressure command from the current calculation cycle with a time delay obtained by subtracting a prescribed fourth time T4 from the third time T3 or later.

[0168] According to this structure, by setting the fourth time T4 to be substantially the same as the response delay time of the actual pilot pressure of the flow control valves 45, 46, 47 (control valves) with respect to the pilot pressure command, the pilot pressure command of each of the flow control valves 45, 46, 47 can be output taking into account the response delay of the flow control valves 45, 46, 47 and the relationship between the response delay of the flow control valves 45, 46, 47 and the response delay of the boom hydraulic cylinder 16, and thus the influence of the response delay of the actual speed of each of the hydraulic actuators 15, 16, 17 with respect to the speed command can be reduced.

[0169] In addition, in the present embodiment, the hydraulic pump 42 has a regulator 42a that can change the pump displacement. The controller 80B is configured to calculate a target pump displacement of the hydraulic pump 42 in response to the speed commands of the plurality of hydraulic actuators 15, 16, 17 of the calculation result, and output the target pump displacement of the calculation result as a pump displacement command to the regulator 42a with a time delay obtained by subtracting a prescribed fifth time T5 from the third time T3 or later from the current calculation cycle.

[0170] According to this structure, by setting the fifth time T5 to be substantially the same as the response delay time of the actual pump displacement of the hydraulic pump 42 with respect to the pump displacement command, the pump displacement command of the hydraulic pump 42 can be output taking into account the response delay of the hydraulic pump 42 and the relationship between the response delay of the hydraulic pump 42 and the response delay of the boom hydraulic cylinder 16, and thus the influence of the response delay of the actual speed of each of the hydraulic actuators 15, 16, 17 with respect to the speed command can be reduced.

[0171] [Other Embodiments]

[0172] Furthermore, the present application is not limited to the above-described embodiments, but includes various modifications. The above-described embodiments are described in detail for the purpose of easily understanding the present application, and are not limited to necessarily having all the structures described. A part of the structure of one embodiment can be replaced with the structure of another embodiment, and in addition, the structure of one embodiment can be added with the structure of another embodiment. In addition, addition, deletion, and replacement of other structures can be made with respect to a part of the structure of each embodiment.

[0173] For example, in the above-described first to third embodiments, a hydraulic excavator provided with a shovel 13 as a work tool (attachment) of the front end of the front work apparatus 1 (work apparatus) is exemplified. However, the present application can also be applied to a hydraulic excavator provided with an attachment other than the shovel 13, such as a rock breaker or a magnet. In addition, as long as the work apparatus is of a multi-joint type having a plurality of driven members (the boom 11, the arm 12, the attachment, and the like) linked, the present application can also be applied to various work machines other than the hydraulic excavator.

[0174] In addition, in the above-described embodiments, the control of forcibly operating the boom hydraulic cylinder 15 in the case where the arm retracting operation of the second operating device 52 is input by the operator is described. However, the present application can also be applied to an unmanned work machine that performs work by the front work apparatus 1 without relying on the operation of the operator. That is, under a prescribed condition, the present application can be applied to control of forcibly operating at least one of the remaining hydraulic cylinders corresponding to the operation of any one of the boom hydraulic cylinder 15, the arm hydraulic cylinder 16, and the shovel hydraulic cylinder 17 that does not depend on the operation of the operating devices 51 to 53.

[0175] Further, in the third embodiment described above, the following example is shown: the delay time of the response of the actual speed of the boom hydraulic cylinder 15 to the speed command is assumed to be substantially the second time T2, and the delay time of the response of the actual speed of the arm hydraulic cylinder 16 to the speed command is assumed to be substantially the third time T3 (the case of the second embodiment), and the delay time of the command output of the actuator control section 917B and the hydraulic pump control section 918B of the controller 80B is set. In contrast to this, it is also possible to set the delay time of the command output of the actuator control section 917B and the hydraulic pump control section 918B of the controller 80B on the assumption that the delay time of the response of the actual speed of the boom hydraulic cylinder 15 and the arm hydraulic cylinder 16 to the speed command is common and substantially the first time Tl (the case of the first embodiment). In this case, the delay time set by the actuator control section 917B is a time (Tl - T4) obtained by subtracting the above-mentioned fourth time T4, which is substantially in agreement with the delay time of the response of the actual pilot pressure of each flow control valve 45 to 47 to the pilot pressure command, from the above-mentioned first time Tl, which is substantially in agreement with the delay time of the response of the actual speed of the arm hydraulic cylinder 16 to the speed command. Further, the delay time set by the hydraulic pump control section 918B is a time (Tl - T5) obtained by subtracting the above-mentioned fifth time T5, which is substantially in agreement with the delay time of the response of the actual displacement of the hydraulic pump 42 to the pump displacement command, from the above-mentioned first time Tl. In this case, the same effects as those of the third embodiment can be obtained.

[0176] BRIEF DESCRIPTION OF DRAWINGS

[0177] 1: front work implement (work implement), 11: boom, 12: arm, 15: boom hydraulic cylinder (first hydraulic actuator), 16: arm hydraulic cylinder (second hydraulic actuator), 17: bucket hydraulic cylinder (hydraulic actuator), 30: posture detection device, 42: hydraulic pump, 42a: regulator, 45: first flow control valve (control valve), 46: second flow control valve (control valve), 47: third flow control valve (control valve), 80, 80A, 80B: controller.

Claims

1. A work machine characterized by, Possessing: a work device that performs work; a plurality of hydraulic actuators that drive the work device; a hydraulic pump that supplies hydraulic oil to the plurality of hydraulic actuators; a plurality of control valves that respectively control the flow of hydraulic oil supplied from the hydraulic pump to each of the plurality of hydraulic actuators; a posture detection device that detects the posture of the work device; and a controller that calculates the speed command of each of the plurality of hydraulic actuators at each calculation cycle, and outputs a control signal for controlling each of the plurality of hydraulic actuators based on the speed command of each of the plurality of hydraulic actuators at the current calculation cycle as a result of the calculation, the controller is configured to: in a case where the operation of a second hydraulic actuator among the plurality of hydraulic actuators is controlled under a predetermined condition in accordance with the operation of a first hydraulic actuator, calculate the actual speed of each of the plurality of hydraulic actuators at the current calculation cycle based on a detection signal of the posture detection device, calculate the speed command of the first hydraulic actuator at the current calculation cycle that satisfies the condition using the actual speed of each of the plurality of hydraulic actuators as a result of the calculation, and a past history of the speed command of each of the plurality of hydraulic actuators calculated in a past calculation cycle compared to the current calculation cycle, and output a control signal for controlling the first hydraulic actuator based on the speed command of the first hydraulic actuator at the current calculation cycle as a result of the calculation, the condition is to position a predetermined control point of the work device on a predetermined target surface, the controller is configured to: shift the past history of the speed command of each of the plurality of hydraulic actuators calculated from the past calculation cycle before a prescribed first time until the current calculation cycle with respect to the actual speed of each of the plurality of hydraulic actuators at the current calculation cycle based on the detection signal of the posture detection device, and make the speed command of each of the plurality of hydraulic actuators in the past calculation cycle before the first time coincide with the actual speed of each of the plurality of hydraulic actuators at the current calculation cycle, thereby calculating a predicted value of the speed of each of the plurality of hydraulic actuators, a predicted value of the posture of the work device, and a predicted value of the position of the control point of the work device with respect to the target surface after the first time from the current calculation cycle, calculate a target speed of the first hydraulic actuator that positions the control point of the work device on the target surface after the first time from the current calculation cycle as the speed command of the first hydraulic actuator at the current calculation cycle based on the predicted value of the speed, the predicted value of the posture, and the predicted value of the position as a result of the calculation, and output a control signal for controlling the first hydraulic actuator based on the speed command of the first hydraulic actuator at the current calculation cycle as a result of the calculation.

2. The work machine according to claim 1, characterized in that, ​ The plurality of control valves are each a hydraulic pilot type driven by a pilot pressure, The controller is configured to: calculate a target pump displacement of the hydraulic pump based on the speed commands of the plurality of hydraulic actuators according to the calculation results, and cause the target pump displacement of the calculation result to be output as a pump displacement command to the regulator from the current calculation cycle with a time delay obtained by subtracting a prescribed fourth time from the first time or later from the first time.

3. The working machine according to claim 1, wherein the hydraulic pump has a regulator capable of changing a pump displacement, the controller is configured to: calculate a target pump displacement of the hydraulic pump based on the speed commands of the plurality of hydraulic actuators according to the calculation results, and cause the target pump displacement of the calculation result to be output as a pump displacement command to the regulator from the current calculation cycle with a time delay obtained by subtracting a prescribed fifth time from the first time or later from the first time.

4. The working machine according to claim 1, wherein the working device is a front working device including a boom and a stick, the first hydraulic actuator is a boom cylinder that drives the boom, the second hydraulic actuator is a stick cylinder that drives the stick.

5. A work machine characterized by, provided with: a working device that performs work; a plurality of hydraulic actuators that drive the working device; a hydraulic pump that supplies hydraulic oil to the plurality of hydraulic actuators; a plurality of control valves that respectively control the flow of hydraulic oil supplied from the hydraulic pump to each of the plurality of hydraulic actuators; a posture detection device that detects a posture of the working device; and a controller that calculates speed commands of the plurality of hydraulic actuators in calculation cycles and outputs control signals for controlling each of the plurality of hydraulic actuators based on the speed commands of the plurality of hydraulic actuators according to the calculation results, the controller is configured to: in a case where the operation of a second hydraulic actuator among the plurality of hydraulic actuators is controlled under a predetermined condition with respect to the operation of a first hydraulic actuator, calculate actual speeds of the plurality of hydraulic actuators in the current calculation cycle based on a detection signal of the posture detection device, calculate a speed command of the first hydraulic actuator in the current calculation cycle that satisfies the condition using the actual speeds of the plurality of hydraulic actuators according to the calculation results and a past history of the speed commands of the plurality of hydraulic actuators calculated in a calculation cycle that is past compared to the current calculation cycle, and output a control signal for controlling the first hydraulic actuator based on the speed command of the first hydraulic actuator in the current calculation cycle according to the calculation results, the condition is to position a predetermined control point of the working device on a predetermined target surface, the controller is configured to: ​ using the actual speed of each of the plurality of hydraulic actuators obtained based on a detection signal of the posture detection device, a past history of the speed command of the first hydraulic actuator calculated in a period from a past calculation cycle before a prescribed second time compared to the current calculation cycle to the current calculation cycle, and a past history of the speed command of each of the hydraulic actuators other than the first hydraulic actuator calculated in a period from a past calculation cycle before a prescribed third time compared to the current calculation cycle to a past calculation cycle after the second time, which is a longer time than the second time, based on the calculated predicted values of the speed, the posture, and the position, calculating a target speed of the first hydraulic actuator for bringing the control point of the work device onto the target surface as the speed command of the first hydraulic actuator for the current calculation cycle, and outputting a control signal for controlling the first hydraulic actuator based on the calculated speed command of the first hydraulic actuator for the current calculation cycle.

6. The work machine according to claim 5, wherein the plurality of control valves are hydraulic pilot valves each driven by a pilot pressure, the controller is configured to: calculate a target pilot pressure for driving the control valve corresponding to each of the plurality of hydraulic actuators based on the calculated speed command of each of the plurality of hydraulic actuators, and cause the calculated target pilot pressure to be output as a pilot pressure command from the current calculation cycle with a time delay obtained by subtracting a prescribed fourth time from the third time or less from the third time.

7. The work machine according to claim 5, wherein the hydraulic pump has a regulator capable of changing a pump displacement, the controller is configured to: calculate a target pump displacement of the hydraulic pump based on the calculated speed command of each of the plurality of hydraulic actuators, and cause the calculated target pump displacement to be output as a pump displacement command to the regulator from the current calculation cycle with a time delay obtained by subtracting a prescribed fifth time from the third time or less from the third time.

8. The work machine according to claim 5, wherein the work device is a front work device including a boom and a stick, the first hydraulic actuator is a boom cylinder driving the boom, the second hydraulic actuator is a stick cylinder driving the stick.

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