Work machine

Abstract

To provide a work machine that can quickly perform excavation along a target excavation surface while making a work tool with 3-axis rotation freedom squarely face the target excavation surface.SOLUTION: A control device 28 includes a work point coordinate calculation unit 32 that calculates the coordinates of multiple work points 44a, 44b set on a work tool 46, a target point coordinate calculation unit 33 that calculates the coordinates of multiple target points 45a, 45b corresponding respectively to the multiple work points 44a, 44b, a work point deviation calculation unit 34 that calculates each deviation between the coordinates of the multiple work points 44a, 44b and the coordinates of the multiple target points 45a, 45b, a work point velocity vector calculation unit 35 that calculates respective velocity vectors 41a, 41b of the multiple work points 44a, 44b so that the sum of the deviations become small, and an actuator target velocity calculation unit 36 that calculates each target velocity of the multiple actuators 5, 6, 7, 23, 48, 50 based on the respective velocity vectors 41a, 41b.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a work machine such as a hydraulic excavator. [Background technology]

[0002] BACKGROUND ART Conventionally, there has been technology for controlling a tiltrotator bucket that enables the bucket angle to be kept parallel to slopes of any shape in order to improve the efficiency of construction work such as slope excavation.

[0003] For example, Patent Document 1 discloses a system for controlling a work machine that includes a support part operably supported on a vehicle body, a tiltrotator attached to the tip of the support part, and an attachment that has a cutting edge and is supported via the tiltrotator so that it can rotate about three axes that intersect with each other on different planes relative to the support part, the system including a processor that acquires measurement values ​​from a plurality of sensors, calculates the attitude of the attachment with respect to the vehicle body based on the measurement values, determines a virtual rotation axis based on the calculated attitude of the attachment, generates a control signal for the tiltrotator to rotate the attachment about the virtual rotation axis so that a design surface (target excavation surface) and the cutting edge of the attachment approach parallelism, and outputs the generated control signal. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-51363 A Summary of the Invention [Problem to be solved by the invention]

[0005] The system described in Patent Document 1 makes it easy to orient an attachment (work tool) directly toward a target excavation surface. However, when excavating with a work machine to which this system is applied, after performing the operation of orienting the attachment toward the target excavation surface, an additional operation must be performed to excavate with the attachment along the target excavation surface, leaving room for improvement in terms of work efficiency.

[0006] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a work machine that can quickly perform excavation along a target excavation surface while facing a work implement with three rotational degrees of freedom directly against the target excavation surface. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a work machine comprising a lower traveling body, an upper rotating body rotatably attached on the lower traveling body, an articulated work machine equipped with a work implement attached to the upper rotating body so as to be rotatable in the vertical direction and having three degrees of freedom of rotation at its tip, a plurality of actuators for driving the articulated work machine, an actuator speed sensor for detecting the respective speeds of the plurality of actuators, an attitude sensor for detecting the attitude of the upper rotating body and the articulated work machine, and a control device for controlling the plurality of actuators, wherein the control device comprises a work point coordinate calculation unit for calculating the coordinates of a plurality of work points set on the work implement based on detection values ​​of the attitude sensor, and a control unit for calculating the coordinates of a plurality of target points respectively corresponding to the plurality of work points. a working point deviation calculation unit that calculates each deviation between the coordinates of the plurality of working points calculated by the working point coordinate calculation unit and the coordinates of the plurality of target points calculated by the target point coordinate calculation unit; a working point velocity vector calculation unit that calculates each velocity vector of the plurality of working points so that the sum of the deviations calculated by the working point deviation calculation unit becomes small; an actuator target velocity calculation unit that calculates each target velocity of the plurality of actuators based on each velocity vector of the plurality of working points calculated by the working point velocity vector calculation unit; and an actuator control unit that controls the plurality of actuators so that each target velocity calculated by the actuator target velocity calculation unit matches each velocity detected by the actuator velocity sensor. [Effects of the Invention]

[0008] According to the present invention, the operation of facing a work tool having three degrees of rotational freedom toward the target excavation surface and the operation of bringing the work tool to the target excavation surface are performed simultaneously in parallel, making it possible to quickly excavate along the target excavation surface while facing the work tool toward the target excavation surface. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view schematically showing the appearance of a hydraulic excavator, which is an example of a work machine according to a first embodiment. [Figure 2]FIG. 1 is a schematic diagram of a tiltrotator bucket according to a first embodiment. [Figure 3] FIG. 2 is a functional block diagram schematically showing a part of the processing functions of the control device of the hydraulic excavator according to the first embodiment. [Figure 4A] FIG. 3 is a diagram showing a method for facing the tiltrotator bucket and the target excavation surface in the xz plane according to the first embodiment. [Figure 4B] FIG. 3 is a diagram showing a method for facing the tiltrotator bucket and the target excavation surface on the xy plane according to the first embodiment. [Figure 4C] FIG. 3 is a diagram showing a method for facing the tiltrotator bucket and the target excavation surface in the yz plane according to the first embodiment. [Figure 5] 4 is a flowchart showing the processing contents of the control device according to the first embodiment. [Figure 6] FIG. 10 is a functional block diagram schematically showing part of the processing functions of a control device for a hydraulic excavator according to a second embodiment. [Figure 7] FIG. 10 is a schematic diagram showing a method for setting a target point according to a second embodiment. [Figure 8] 10 is a flowchart showing the processing contents of a control device according to a second embodiment. [Figure 9] FIG. 10 is a functional block diagram schematically showing part of the processing functions of a control device for a hydraulic excavator according to a third embodiment. [Figure 10] 10 is a flowchart showing the processing contents of a control device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, a hydraulic excavator equipped with a front working implement (working device) will be described as an example of a work machine, but the present invention can also be applied to other machines equipped with mechanisms that include multiple rotational movements, such as industrial or medical robot arms. [Example]

[0011] A first embodiment of the present invention will be described with reference to FIGS.

[0012] Fig. 1 is a perspective view showing a typical appearance of a hydraulic excavator, which is an example of a work machine according to this embodiment, Fig. 2 is a typical view of a tiltrotator bucket according to this embodiment, and Fig. 3 is a functional block diagram showing a typical portion of the processing functions of a control device for the hydraulic excavator according to this embodiment.

[0013] 1 and 2, the hydraulic excavator 100 includes a front working machine (articulated working machine) 24 configured by connecting a plurality of driven members (a boom 8, an arm 9, and a bucket (work implement) 10) that each rotate in a vertical direction, and an upper rotating body 22 and a lower traveling body 20 that form a vehicle body, and the upper rotating body 22 is provided so as to be able to rotate relative to the lower traveling body 20 via a swing mechanism 21. The swing mechanism 21 includes a swing motor 23 and an attitude sensor 26D, and the swing motor 23 drives the upper rotating body 22 to swing relative to the lower traveling body 20, and the attitude sensor 26D detects the swing angle relative to the lower traveling body 20.

[0014] The base end of a boom 8 of the front working implement 24 is supported at the front of the upper rotating body 22 so as to be rotatable in the vertical direction, one end of an arm 9 is supported at an end (tip) different from the base end of the boom 8 so as to be rotatable in the vertical direction, and a bucket (work implement) 10 is supported at the other end of the arm 9 so as to be rotatable in the vertical direction. The boom 8, arm 9, bucket 10, upper rotating body 22, and lower traveling body 20 are driven by hydraulic actuators, namely, a boom cylinder 5, an arm cylinder 6, a bucket cylinder 7, a swing motor 23, and left and right traveling motors 3 (only one traveling motor is shown), respectively.

[0015] Here, a vehicle body coordinate system is set up with the intersection of the rotation center axis 25 of the upper rotating body 22 and the underside of the upper rotating body 22 as the origin, the z-axis being positive upward along the rotation center axis 25, the x-axis being positive forward in the fore-and-aft direction from the origin perpendicular to the z-axis, and the y-axis being positive rightward in the left-right direction from the origin perpendicular to the z-axis and x-axis.

[0016] A cab 2 on which an operator sits is mounted on the front left side of the upper rotating body 22. A control device 28 that controls the overall operation of the hydraulic excavator 100 is also disposed on the upper rotating body 22. The cab 2 is provided with operation levers (operation devices) 2a, 2b that output operation signals for operating the hydraulic actuators 5 to 7, 23. Although not shown, the operation levers 2a, 2b can each be tilted forward, backward, left, and right, and include a detection device (not shown) that electrically detects the amount of tilt of the lever, which is the operation signal, i.e., the lever operation amount, and outputs the lever operation amount detected by the detection device to the control device 28 (described below) via electrical wiring. In other words, the operation of the hydraulic actuators 5 to 7, 23 is assigned to the forward, backward, left, and right directions of the operation levers 2a, 2b, respectively.

[0017] The operation of the boom cylinder 5, arm cylinder 6, bucket cylinder 7, swing motor 23, and left and right traveling motors 3 is controlled by using a control valve or the like to control the direction and flow rate of hydraulic oil supplied to each of the hydraulic actuators 3, 5 to 7, 23 from a hydraulic pump device driven by a prime mover such as an engine or electric motor (not shown). The operation of the control valve is controlled by a control device 28 based on operation signals from operation levers 2a and 2b, thereby controlling the operation of each of the hydraulic actuators 5 to 7, 23.

[0018] Attitude sensors 26A, 26B, and 26C are attached to the base of the boom 8, the connection between the boom 8 and the arm 9, and the connection between the arm 9 and the bucket 10, respectively, and an attitude sensor 26D is attached to the upper rotating structure 22. As shown in FIG. 3 , attitude sensor 26A measures the angle between the longitudinal direction of the boom 8 (a line connecting the rotation centers at both ends) and the xy plane and transmits the measured value to the control device 28. Attitude sensor 26B measures the angle between the longitudinal direction of the boom 8 (a line connecting the rotation centers at both ends) and the longitudinal direction of the arm 9 (a line connecting the rotation centers at both ends) and transmits the measured value to the control device 28. Attitude sensor 26C measures the angle between the longitudinal direction of the arm 9 (a line connecting the rotation centers at both ends) and the longitudinal direction of the bucket 10 (a line connecting the rotation center and the toe) and transmits the measured value to the control device 28. Attitude sensor 26D measures the tilt angle of the upper rotating structure 22 and transmits the measured value to the control device 28.

[0019] In this embodiment, the swing center 27 of the front working implement 24 (the connection point between the boom 8 and the upper rotating body 22) is described as being located at a position different from the central axis of rotation 25, but the central axis of rotation 25 and the swing center 27 may also be located so that they intersect.

[0020] Furthermore, as shown in FIG. 2, the hydraulic excavator 100 according to this embodiment is provided with a tiltrotator bucket (work implement) 46, instead of the standard bucket 10, which is provided with a tilt cylinder 48, which is a hydraulic actuator for controlling the tilt angle, and a rotary motor 50, which is a hydraulic actuator for controlling the rotary angle. An attitude sensor 26E for measuring the tilt angle and rotary angle of the tiltrotator bucket 46 is attached to the rotating portion of the tiltrotator bucket 46. The left and right interlocking tilt cylinders 48 are swung up and down by operation of the operator, causing the tiltrotator bucket 46 to swing left and right about the tilt axis 47. The rotary motor 50 is also rotated 360 degrees by operation of the operator, causing the tiltrotator bucket 46 to rotate about the tiltrotator rotation axis 49. By making full use of these mechanisms, it is possible to flexibly respond to a target excavation surface 42 composed of multiple planes.

[0021] In this embodiment, it is assumed that mechanical angle sensors such as potentiometers are used as the attitude sensors 26A to 26E, but an inertial measurement unit (IMU) may also be used.

[0022] The actuators 5 to 7, 23, 48, and 50 are provided with actuator speed sensors 5S, 6S, 7S, 23S, 48S, and 50S that detect the speeds of the actuators 5 to 7, 23, 48, and 50. The actuator speed sensors 5S, 6S, 7S, 23S, 48S, and 50S are composed of a rotation angle sensor, a stroke sensor, and the like.

[0023] 3, the control device 28 includes a working point coordinate calculation unit 32, a target point coordinate calculation unit 33, a working point deviation calculation unit 34, a working point velocity vector calculation unit 35, an actuator target velocity calculation unit 36, and an actuator control unit 37. The control device 28 includes a calculation unit such as a CPU, storage devices such as a ROM and RAM, an input / output interface for inputting and outputting signals to and from external devices, and the functions of each unit are realized by executing a program stored in the ROM or the like.

[0024] The working point coordinate calculation unit 32 calculates the coordinates of each of the specified working points 44a, 44b in a global coordinate system or a local coordinate system based on the work machine, based on the posture information detected by the posture sensors 26A to 26E and the coordinates of at least two points within the components of the work implement set by the operator via the user interface (input device) 29, and transmits these to the target point coordinate calculation unit 33 and the working point deviation calculation unit 34. A specific method for setting each of the working points 44a, 44b will be described later.

[0025] Based on the coordinates of each working point 44a, 44b calculated by the working point coordinate calculation unit 32 and the design information 31 of the construction target input via the user interface 29, the target point coordinate calculation unit 33 calculates the coordinates of the point where the distance between each working point 44a, 44b and the target excavation surface 42 is shortest in a global coordinate system or a local coordinate system based on the work machine, and transmits these as target points 45a, 45b to the working point deviation calculation unit 34. The specific calculation method for each target point 45a, 45b will be described later.

[0026] The work point deviation calculation unit 34 calculates the deviation between the coordinates of each work point 44a, 44b calculated by the work point coordinate calculation unit 32 and the coordinates of each target point 45a, 45b calculated by the target point coordinate calculation unit 33, and transmits it to the work point velocity vector calculation unit 35.

[0027] The working point velocity vector calculation unit 35 generates velocity vectors 41a, 41b directed toward each target point 45a, 45b for each working point 44a, 44b from the deviation between each working point 44a, 44b and each target point 45a, 45b calculated by the working point deviation calculation unit 34, and transmits these to the actuator target velocity calculation unit 36. The velocity vectors 41a, 41b can be obtained by dividing the deviation between each working point 44a, 44b and each target point 45a, 45b by the control period of the control device 28.

[0028] The actuator target velocity calculation unit 36 ​​calculates the target velocity of each actuator based on the velocity vectors 41a, 41b of each working point 44a, 44b calculated by the working point velocity vector calculation unit 35, and transmits the calculated target velocity to the actuator control unit 37. Here, there is a method for calculating the target velocity of the actuator so as to minimize the deviation between each working point 44a, 44b and each target point 45a, 45b by using the deviation between each working point 44a, 44b and each target point 45a, 45b as an evaluation function, such as in model predictive control (MPC).

[0029] The actuator control unit 37 operates the control valves of the actuators 5 to 7, 23, 48, and 50 based on the target speeds of the actuators 5 to 7, 23, 48, and 50 calculated by the actuator target speed calculation unit 36, and matches the speeds of the actuators 5 to 7, 23, 48, and 50 to the target speeds based on the responses of the actuators 5 to 7, 23, 48, and 50 calculated by the actuator speed sensors 5S, 6S, 7S, 23S, 48S, and 50S.

[0030] 4A to 4C are diagrams showing how tiltrotator bucket 46 according to the first embodiment faces the target excavation surface on each plane.

[0031] First, a method for specifying the work points 44a and 44b will be described. Input to the control device 28 is performed by preparing a user interface 29 having a device such as a touch monitor, and specifying two or more points on a schematic diagram of the tiltrotator bucket 46 displayed on the screen. As shown in FIGS. 4A to 4C , for example, one method is to prepare models of the tiltrotator bucket 46 in the x-z plane, x-y plane, and y-z plane, and specify the work points 44a and 44b on each plane. Alternatively, a 3D model of the tiltrotator bucket 46 may be prepared, and the work points 44a and 44b may be specified by moving or rotating the 3D model. Furthermore, while it is possible to select two or more work points 44a and 44b, the calculation load on the control device 28 increases as the number of work points 44a and 44b increases. Therefore, the limit on the number of work points 44a and 44b that can be specified is determined by the computing power of the control device 28. Note that if it is difficult to specify two or more work points 44a, 44b for some reason, care must be taken because, depending on the shape of the target excavation surface 42, it may not be possible to generate the expected operation.

[0032] Next, a method for calculating the target points 45a, 45b will be described. First, based on information on the target excavation surface 42, the shortest distance from each of the working points 44a, 44b to the target excavation surface 42 is calculated while maintaining the distance between each of the working points 44a, 44b at the current time. Specifically, assuming that the x-coordinate, y-coordinate, and z-coordinate of working point 44a are Xax, X_ay, and X_az, respectively, the x-coordinate, y-coordinate, and z-coordinate of working point 44b are Xbx, Xby, and Xbz, respectively, and further that the x-coordinate, y-coordinate, and z-coordinate of target point 45a are ξax, ξay, and ξaz, respectively, and the x-coordinate, y-coordinate, and z-coordinate of target point 45b are ξbx, ξby, and ξbz, respectively, target points 45a and 45b are set so that the sum of the deviation between working point 44a and target point 45a and the deviation between working point 44b and target point 45b (equation 2) is smallest under the condition that the distance between working points 44a and 44b is equal to the distance between target points 45a and 45b (equation 1).

[0033]

number

[0034]

number

[0035] Next, the calculation process of the working point deviation calculation unit 34 and the method of generating the velocity vectors 41a, 41b will be described. Like the target point coordinate calculation unit 33, the working point deviation calculation unit 34 calculates each deviation between the working points 44a, 44b and the target points 45a, 45b. The working point velocity vector calculation unit 35 generates velocity vectors 41a, 41b at each working point 44a, 44b by dividing each deviation calculated by the working point deviation calculation unit 34 by the control period. Note that one method for further improving control performance is to calculate the deviation between the working points 44a, 44b and the target points 45a, 45b for N steps of the control period and adjust the velocity vectors 41a, 41b. Specifically, this method predicts the position to which the current working points 44a, 44b will move after N control cycle steps, and adjusts the velocity vectors 41a, 41b so as to reduce the difference between the working points 44a, 44b and the target points 45a, 45b after N control cycle steps.

[0036] The actuator target velocity calculation unit 36 ​​integrates the multiple velocity vectors 41a and 41b obtained from the working point velocity vector calculation unit 35 to calculate the target velocities of the boom cylinder 5, arm cylinder 6, bucket cylinder 7, swing motor 23, tilt cylinder 48, and rotary motor 50. First, in the case of FIG. 4A, because the side of the tiltrotator bucket 46 is parallel to the xz plane, priority is given to the operation of the boom cylinder 5, arm cylinder 6, and bucket cylinder 7 based on the velocity vectors 41a and 41b. On the other hand, in the case of FIG. 4B, it can be seen that velocity vector 41a is greater than velocity vector 41b. In other words, because the movement amount of working point 44a of the tiltrotator bucket 46 is greater than that of working point 44b, rotational movement around the z-axis (in this case, rotary movement) is required. Here, because it is difficult for the operation of the swing motor 23 to move working points 44a and 44b to reach target points 45a and 45b, priority is given to the operation of the rotary motor 50. 4C, as in the case of FIG. 4B, it can be seen that velocity vector 41a of working point 44a is greater than velocity vector 41b of working point 44b. In other words, because the movement amount of working point 44a of tiltrotator bucket 46 is greater than that of working point 44b, a rotational movement about the x-axis (a tilting movement in this case) is required. Because it is difficult to make working points 44a and 44b reach target points 45a and 45b with the combination of boom cylinder 5, arm cylinder 6, and bucket cylinder 7, the tilting movement of tilt cylinder 48 takes priority.

[0037] FIG. 5 is a flowchart showing the processing contents of the control device according to the first embodiment.

[0038] 5, in the control device 28, the operator specifies working points 44a, 44b via the user interface 29 (step S110), and the operator inputs design information 31 via the user interface 29 (step S120). The attitude of each actuator is detected using an inertial measurement unit, a rotation angle sensor, a stroke sensor, etc. (step S130), and the coordinates of the working points 44a, 44b specified in step S110 are calculated (step S140). Based on the coordinates of the working points 44a, 44b calculated in step S140, the coordinates of the target points 45a, 45b are calculated (step S150), the deviations between each of the working points 44a, 44b and each of the target points 45a, 45b are calculated (step S160), and velocity vectors 41a, 41b directed from each of the working points 44a, 44b to each of the target points 45a, 45b are generated (step S170). The actuator speed is calculated based on the generated velocity vectors 41a, 41b (step S180), and the actuator is operated (step S190). Through the above processing, tiltrotator bucket 46 can be made to face directly at and reach target excavation surface 42.

[0039] (summary) In the first embodiment, the multi-joint work machine 24 includes a lower traveling body 20, an upper rotating body 22 rotatably attached to the lower traveling body 20, an articulated work machine 24 rotatably attached to the upper rotating body 22 in the vertical direction and having a work implement 46 at its tip with three degrees of freedom of rotation about three axes, a plurality of actuators 5 to 7, 23, 48, 50 that drive the articulated work machine 24, and actuator speed sensors 5S, 6S, 7S, 23S, 48S, 5 for detecting the speeds of the plurality of actuators 5, 6, 7, 23, 48, 50. In a work machine (100) having a rotating body (22) and an articulated work implement (24), attitude sensors (26A-26E) for detecting the attitude of the rotating body (22) and the articulated work implement (24), and a control device (28) for controlling a plurality of actuators (5, 6, 7, 23, 48, 50, the control device (28) has a work point coordinate calculation unit (32) for calculating the coordinates of a plurality of work points (44a, 44b) set on a work implement (46) based on the detected values ​​of the attitude sensors (26A-26E), and a control device (28) for calculating the coordinates of a plurality of target points (45a, 45b) corresponding to the plurality of work points (44a, 44b), respectively. a target point coordinate calculation unit 33 for calculating coordinates; a working point deviation calculation unit 34 for calculating deviations between the coordinates of the plurality of working points 44a, 44b calculated by the working point coordinate calculation unit 32 and the coordinates of the plurality of target points 45a, 45b calculated by the target point coordinate calculation unit 33; a working point velocity vector calculation unit 35 for calculating velocity vectors 41a, 41b of the plurality of working points 44a, 44b so that the sum of the deviations calculated by the working point deviation calculation unit 34 is small; The actuator control unit 37 includes an actuator target speed calculation unit 36 ​​that calculates target speeds for the plurality of actuators 5, 6, 7, 23, 48, and 50 based on the respective speed vectors 41a and 41b of the points 44a and 44b, and an actuator control unit 37 that controls the plurality of actuators 5, 6, 7, 23, 48, and 50 so that the target speeds calculated by the actuator target speed calculation unit 36 ​​coincide with the respective speeds detected by the actuator speed sensors 5S, 6S, 7S, 23S, 48S, and 50S.

[0040] According to the first embodiment configured as described above, the operation of facing the work tool 46, which has three degrees of rotational freedom, directly toward the target excavation surface 42 and the operation of making the work tool 46 reach the target excavation surface 42 are performed simultaneously in parallel, making it possible to quickly excavate along the target excavation surface 42 while facing the work tool 46 directly toward the target excavation surface 42.

[0041] In the first embodiment, the multiple working points 44a, 44b set on the work tool 46 include a first working point 44a and a second working point 44b, and the multiple target points 45a, 45b corresponding to the multiple working points 44a, 44b, respectively, include a first target point 45a corresponding to the first working point 44a and a second target point 45b corresponding to the second working point 44b, and the target point coordinate calculation unit 33 sets the first target point 45a and the second target point 45b so that the distance between the first target point 45a and the second target point 45b is equal to the distance between the first working point 44a and the second working point 44b and the sum of the deviation between the first working point 44a and the first target point 45a and the deviation between the second working point 44b and the second target point 45b is minimized. This makes it possible for the tip of the work tool 46 to face directly at and reach the target excavation surface 42 as quickly as possible. [Example]

[0042] A second embodiment of the present invention will be described with reference to FIGS.

[0043] In the first embodiment, the operator specified the positions of the working points 44a and 44b via the user interface 29, but in this embodiment, the tiltrotator bucket 46 is aligned with the toe direction specified by the operator via the user interface (input device) 29, and excavation is performed quickly along the target excavation surface 42 while facing the tiltrotator bucket 46 directly toward the target excavation surface 42.

[0044] Fig. 6 is a functional block diagram showing a part of the processing functions of the control device 28 mounted on the hydraulic excavator 100 in the second embodiment. Fig. 7 is a schematic diagram showing a method for setting a target point in the second embodiment. Fig. 8 is a flowchart showing the processing contents of the control device in the second embodiment. In the figure, the same members as those in the first embodiment are given the same reference numerals, and their explanation will be omitted.

[0045] As shown in FIG. 6 , the operator uses the user interface 29 to input the toe direction of the tiltrotator bucket 46, which is the direction in which the operator wants to operate (requested direction). Specifically, for input to the control device 28, a user interface 29 having a device such as a touch monitor is prepared, and the toe direction of the tiltrotator bucket 46 is specified on a schematic diagram of the tiltrotator bucket 46 displayed on the screen. For example, one method is to prepare a model of the tiltrotator bucket 46 on the xy plane, and have the operator refer to an overhead video image and specify the toe direction of the tiltrotator bucket 46 on the xy plane. Alternatively, a 3D model of the tiltrotator bucket 46 may be prepared, and the toe direction of the tiltrotator bucket 46 may be specified while moving or rotating the 3D model of the tiltrotator bucket 46.

[0046] In this embodiment, the working point coordinate calculation unit 32 calculates the coordinates of at least two working points 44a, 44b within a predetermined component of the tiltrotator bucket 46. Note that, since the calculation load on the control device 28 increases as the number of calculated working points 44a, 44b increases, a limit on the number of calculated working points 44a, 44b is determined based on the calculation capacity of the control device 28.

[0047] FIG. 7 is a schematic diagram showing a method for setting a target point according to the second embodiment.

[0048] As shown in FIG. 7 , target point coordinate calculation unit 33 calculates the coordinates of each of target points 45 a, 45 b based on toe direction 51 of tiltrotator bucket 46 and design information 31 obtained from user interface 29, and the coordinates of at least two working points 44 a, 44 b within the constituent members of tiltrotator bucket 46 calculated by working point coordinate calculation unit 32. Specifically, the tiltrotator bucket 46 is virtually rotated so that the cutting edge direction of the tiltrotator bucket 46 coincides with the toe direction 51 specified via the user interface 29, and each of the working points 44a, 44b on the virtually rotated tiltrotator bucket 46 is set as virtual working points 44aX, 44bX, and the first target point 45a and the second target point 45b are set so that the distance between the first target point 45a and the second target point 45b is equal to the distance between the first virtual working point 44aX and the second virtual working point 44bX and so that the sum of the deviation between the first virtual working point 44aX and the first target point 45a and the deviation between the second virtual working point 44bX and the second target point 45b is minimized.

[0049] The other configurations are the same as those of the first embodiment.

[0050] FIG. 8 is a flowchart showing the processing contents of the control device according to the second embodiment.

[0051] 8, the operator specifies the tiptoe direction of the tiltrotator bucket 46 via the user interface 29 (step S210), and the operator inputs design information 31 via the user interface 29 (step S220). The control device 28 detects the attitude of each actuator using an inertial measurement unit, a rotation angle sensor, a stroke sensor, etc. (step S230), and calculates the coordinates of a plurality of predetermined working points 44a, 44b (step S240). Based on the coordinates of the working points 44a, 44b calculated in step S240, the toe direction of the tiltrotator bucket 46 obtained in step S210, and the design information 31 obtained in step S220, the coordinates of the target points 45a, 45b are calculated (step S250), the deviations between each working point 44a, 44b and each target point 45a, 45b are calculated (step S260), and velocity vectors 41a, 41b directed from each working point 44a, 44b to each target point 45a, 45b are generated (step S270). The velocity of the actuator is calculated based on each generated velocity vector 41a, 41b (step S280), and the actuator is operated (step S290).

[0052] (summary) In the second embodiment, the work machine 100 is provided with an input device 29 for specifying the toe direction of the work implement 46, and the plurality of work points 44a, 44b set on the work implement 46 include a first work point 44a and a second work point 44b, and the plurality of target points 45a, 45b corresponding to the plurality of work points 44a, 44b respectively include a first target point 45a corresponding to the first work point 44a and a second target point 45b corresponding to the second work point 44b, and the target point coordinate calculation unit 33 calculates the toe direction of the work implement 46 by calculating the toe direction 51 specified by the input device 29. The work tool 46 is virtually rotated as shown above, and the first work point 44a and the second work point 44b on the virtually rotated work tool 46 are set as a first virtual work point 44aX and a second virtual work point 44bX. The first target point 45a and the second target point 45b are set so that the distance between the first target point 45a and the second target point 45b is equal to the distance between the first virtual work point 44aX and the second virtual work point 44bX and so that the sum of the deviation between the first virtual work point 44aX and the first target point 45a and the deviation between the second virtual work point 44bX and the second target point 45b is minimized.

[0053] According to the second embodiment configured as described above, it is possible to align the toe direction of the work tool 46, which has three degrees of rotational freedom, in the direction intended by the operator, and to quickly perform excavation along the target excavation surface 42 by facing the tip of the work tool 46 directly toward the target excavation surface 42 as quickly as possible. [Example]

[0054] A third embodiment of the present invention will be described with reference to FIGS.

[0055] In the second embodiment, the operator specified the tiptoe direction of the tiltrotator bucket 46 via the user interface 29, but in this embodiment, based on design information 31 of the construction target and a motion path 53 of the tiltrotator bucket 46 obtained from an input unit 52 of not only the user interface 29 but also another control device or the like, the tiltrotator bucket 46 is moved along the motion path 53, and excavation is performed quickly along the target excavation surface 42 while the tiltrotator bucket 46 is positioned directly against the target excavation surface 42.

[0056] Fig. 9 is a functional block diagram showing a part of the processing function of the control device of the hydraulic excavator according to the third embodiment. Also, Fig. 10 is a flowchart showing the processing contents of the control device according to the third embodiment. In the figure, the same members as those in the first and second embodiments are given the same reference numerals, and the description thereof will be omitted.

[0057] As shown in FIG. 9, the control device 28 acquires design information and a movement path 53 input by the operator as the path (trajectory) along which the operator wants to move the bucket 46 via an input unit 52, such as a user interface 29 or another control device. The target point coordinate calculation unit 33 calculates multiple target points along the path based on the acquired movement path 53 and the design information. The movement path 53 is composed of two points, a work start point and a work end point, or a work start point, a work end point, and one or more relay points. The target point coordinate calculation unit 33 calculates target points 45a, 45b corresponding to each of the work points 44a, 44b for each of the work start point, work end point, and relay point within the movement path 53, establishes virtual relay points according to the control cycle of the control device 28, and sets target points 45a, 45b for each virtual relay point.

[0058] FIG. 10 is a flowchart showing the processing contents of the control device according to the third embodiment.

[0059] 10, the control device 28 acquires the motion path 53 from the input unit 52 of the user interface 29, another control device, or the like (step S310), and acquires the design information from the input unit 52 of the user interface 29, another control device, or the like (step S320).The control device 28 detects the attitude of each actuator using an inertial measurement unit, a rotation angle sensor, a stroke sensor, or the like (step S330), and calculates the coordinates of a plurality of predetermined working points 44a, 44b (step S340). Based on the coordinates of the working points 44a, 44b calculated in step S340, the motion path 53 obtained in step S310, and the design information 31 obtained in step S320, the coordinates of the target points 45a, 45b are calculated (step S350), the deviations between each working point 44a, 44b and each target point 45a, 45b are calculated (step S360), and velocity vectors 41a, 41b directed from each working point 44a, 44b to each target point 45a, 45b are generated (step S370). The velocity of the actuator is calculated based on each generated velocity vector 41a, 41b (step S380), and the actuator is operated (step S390).

[0060] The other configurations are the same as those of the first and second embodiments.

[0061] (summary) In the third embodiment, the target point coordinate calculation unit 33 acquires the movement path 53 of the work tool 46 and the design information 31 of the construction target, sets a virtual relay point on the movement path 53 according to the control cycle of the control device 28, and sets target points 45a, 45b at the start point of the movement path 53, the virtual relay point, and the end point of the movement path 53, respectively, based on the design information 31.

[0062] According to the third embodiment configured as described above, the work tool 46, which has three rotational degrees of freedom, can be moved along the operating path 53, and the work tool 46 can be quickly brought directly facing the target excavation surface 42, allowing for quick excavation along the target excavation surface 42.

[0063] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments are presented to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. [Explanation of symbols]

[0064] DESCRIPTION OF SYMBOLS 2...cab, 2a, 2b...operating levers, 3...travel motor (actuator), 5...boom cylinder (actuator), 5S...actuator speed sensor, 6...arm cylinder (actuator), 6S...actuator speed sensor, 7...bucket cylinder (actuator), 7S...actuator speed sensor, 8...boom, 9...arm, 10...bucket (work implement), 20...lower traveling body, 21...swing mechanism, 22...upper rotating body, 23...swing motor (actuator), 23S...actuator speed sensor, 24...front working implement, 25...swing central axis, 26A to 26E...attitude sensors, 27...swing center, 28...control device, 29...user interface (input device), 32...working point coordinate calculation unit, 33...target point coordinate calculation unit, 34...working point deviation calculation unit , 35...working point velocity vector calculation unit, 36...actuator target velocity calculation unit, 37...actuator control unit, 41a, 41b...velocity vector, 42...target excavation surface, 44a...working point (first working point), 44aX...virtual working point (first virtual working point), 44b...working point (second working point), 44bX...virtual working point (second virtual working point), 45a...target point (first target point), 45b...target point (second target point), 46...tiltrotator bucket (work tool), 47...tilt axis, 48...tilt cylinder (actuator), 48S...actuator speed sensor, 49...tiltrotator rotate axis, 50...rotary motor (actuator), 50S...actuator speed sensor, 51...toe direction, 52...input unit, 53...motion path, 100...hydraulic excavator (work machine).

Claims

1. a lower running body; an upper rotating body rotatably attached on the lower traveling body; a multi-joint working machine that is attached to the upper rotating body so as to be rotatable in the vertical direction and has a working tool at its tip that has three degrees of rotational freedom; a plurality of actuators for driving the articulated working machine; an actuator speed sensor for detecting the speed of each of the plurality of actuators; a posture sensor for detecting the postures of the upper rotating body and the articulated work machine; a control device for controlling a plurality of the actuators, The control device a work point coordinate calculation unit that calculates the coordinates of a plurality of work points set on the work tool based on the detection values ​​of the attitude sensor; a target point coordinate calculation unit that calculates the coordinates of a plurality of target points corresponding to the plurality of work points; a working point deviation calculation unit that calculates deviations between the coordinates of the plurality of working points calculated by the working point coordinate calculation unit and the coordinates of the plurality of target points calculated by the target point coordinate calculation unit; a working point velocity vector calculation unit that calculates velocity vectors of the plurality of working points so that the sum of the deviations calculated by the working point deviation calculation unit becomes small; an actuator target velocity calculation unit that calculates target velocities of the actuators based on the velocity vectors of the working points calculated by the working point velocity vector calculation unit; an actuator control unit that controls the plurality of actuators so that each target speed calculated by the actuator target speed calculation unit coincides with each speed detected by the actuator speed sensor; A work machine characterized by:

2. 2. The work machine according to claim 1, the plurality of working points include a first working point and a second working point; the plurality of target points include a first target point corresponding to the first working point and a second target point corresponding to the second working point; The target point coordinate calculation unit sets the first target point and the second target point so that a distance between the first target point and the second target point is equal to a distance between the first working point and the second working point, and a sum of a deviation between the first working point and the first target point and a deviation between the second working point and the second target point is minimized. A work machine characterized by:

3. 2. The work machine according to claim 1, an input device for specifying the tip direction of the work tool; the plurality of working points include a first working point and a second working point; the plurality of target points include a first target point corresponding to the first working point and a second target point corresponding to the second working point; The target point coordinate calculation unit The work tool is virtually rotated so that the tip direction of the work tool coincides with the tip direction specified by the input device; the first working point and the second working point on the virtually rotated work tool are defined as a first virtual working point and a second virtual working point; The first target point and the second target point are set so that the distance between the first target point and the second target point is equal to the distance between the first virtual work point and the second virtual work point, and the sum of the deviation between the first virtual work point and the first target point and the deviation between the second virtual work point and the second target point is minimized. A work machine characterized by:

4. 4. The work machine according to claim 3, The target point coordinate calculation unit Acquire the operation path of the work tool and design information of the construction target; providing a virtual relay point on the operation path in accordance with a control cycle of the control device; Based on the design information, the target points are set at the start point of the motion path, the virtual relay point, and the end point of the motion path. A work machine characterized by:

Images