Work machine

Abstract

Provided is a work machine capable of performing an appropriate work operation with an attachment according to the state of a work target. The work machine includes an attachment (33) that performs a work operation, a height detection unit that detects the height of a work target (60) at multiple detection positions (P1, P2), and a control unit that controls the work operation. The control unit acquires information about the state of the work target (60) on the basis of the detected heights, sets a target work trajectory on the basis of the state information, and controls the work operation such that the attachment (33) moves along the target work trajectory.

Description

Work machine

[0001] The present invention relates to a work machine.

[0002] Patent Document 1 discloses an automatic driving excavator, which includes a hydraulic excavator and an automatic driving input / output device built in the hydraulic excavator. The automatic driving input / output device repeats an operation that goes around from excavation to dumping by a playback operation, and the operation is taught in advance. Specifically, the automatic driving includes means for setting different repeatable numbers of excavation depths corresponding to the excavation limit depth, and means for repeating the operation that goes around a set number of times while increasing the excavation depth every time the reproduced operation goes around.

[0003] However, the operation disclosed in Patent Document 1 does not necessarily correspond to the shape of the work object at the excavation location and the like.

[0004] Japanese Patent Laid-Open No. 11-158933

[0005] An object of the present invention is to provide a work machine capable of causing an attachment to perform an appropriate work operation corresponding to the state of a work object.

[0006] Provided is a work machine, which includes an attachment capable of performing a work operation for performing work, a height detection unit that respectively detects the heights of a work object, which is the object of the work, at a plurality of positions, and a control unit that controls the work operation. The control unit performs a state information acquisition process for acquiring state information, which is information on a state of the work object related to the work operation, based on the heights of the work object detected at the plurality of positions, a trajectory setting process for setting a target work trajectory, which is a target of a trajectory of the attachment performing the work operation, based on the state information acquired by the state information acquisition process, and an operation control process for controlling the work operation of the attachment so that the attachment moves along the target work trajectory.

[0007] This is a side view of a work machine according to the first embodiment of the present invention. This is a block diagram showing a control system mounted on the work machine. This is a side view showing the initial target work trajectory according to the first embodiment. This is a side view showing an example of a target work trajectory set by the control unit according to the first embodiment. This is a side view showing a first example of a target work trajectory set by the control unit according to the second embodiment of the present invention. This is a side view showing a second example of a target work trajectory set by the control unit according to the second embodiment. This is a side view showing the initial target work trajectory according to the third embodiment of the present invention. This is a side view showing an example of a target work trajectory set by the control unit according to the third embodiment. This is a side view showing the state in which the lifting magnet of the work machine according to the third embodiment is attracting metal scrap. This is a side view showing the state in which the lifting magnet according to a comparative example is attracting metal scrap. This is a side view showing the initial target work trajectory according to the fourth embodiment of the present invention. This is a side view showing the initial target work trajectory according to the fifth embodiment of the present invention. This is a side view showing an example of a target work trajectory set by the control unit according to the fourth embodiment. This is a side view showing an example of a target work trajectory set by the control unit according to the fifth embodiment.

[0008] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0009] A first embodiment of the present invention will be described with reference to Figures 1 to 4.

[0010] Figure 1 shows a work machine 1 according to the first embodiment. The work machine 1 is a shovel. The work machine 1 comprises a lower traveling body 10, an upper rotating body 20 attached to the lower traveling body 10 so as to be able to rotate relative to the lower traveling body 10, and a work device 30 attached to the upper rotating body 20 so as to be able to raise and lower. The work machine according to the present invention may be a work machine other than a shovel.

[0011] The lower traveling body 10 illustrated in Figure 1 is a crawler-type traveling body including a pair of crawlers. However, the work machine according to the present invention is not limited to one equipped with a crawler-type traveling body.

[0012] The upper slewing body 20 includes a driver's cab 21 and a machine room 22. The driver's cab 21 allows an operator to board it for operation. The machine room 22 is located behind the driver's cab 21. An operating unit (not shown) is provided in the driver's cab 21, to which the operator can operate, for example, the lower traveling body 10, the upper slewing body 20, and the work device 30 and other elements. The upper slewing body 20 further includes a slewing device 24 shown in Figure 2. The slewing device 24 includes, for example, a slewing motor, which slewing the upper slewing body 20 relative to the lower traveling body 10.

[0013] As shown in Figure 1, the work device 30 includes a boom 31, an arm 32, an attachment 33, a boom cylinder 34, an arm cylinder 35, and an attachment cylinder 36.

[0014] The boom 31 has a boom base end and a boom tip on the opposite side, and the boom base end is rotatably connected to the upper slewing body 20 so that the boom 31 can perform luffing movements relative to the upper slewing body 20. The arm 32 has an arm base end and an arm tip on the opposite side, and the arm base end is rotatably connected to the boom tip. The attachment 33 is rotatably connected to the arm tip and is capable of performing work movements. In the work machine 1 illustrated in Figure 1, the attachment 33 is a bucket.

[0015] Each of the boom cylinder 34, the arm cylinder 35, and the attachment cylinder 36 is a hydraulic cylinder capable of extending and retracting. The boom cylinder 34 extends and retracts to cause the boom 31 to perform the luffing motion relative to the upper slewing body 20. The arm cylinder 35 extends and retracts to cause the arm 32 to rotate relative to the boom 31. The attachment cylinder 36 extends and retracts to cause the attachment 33 to rotate relative to the arm 32.

[0016] The aforementioned work machine 1 further comprises the control system shown in Figure 2. The control system includes a control unit 40, a storage unit 42, a detection unit 44, a plurality of angle sensors, a GNSS 48, a compass 50, a video camera 52, and an input / output device 54.

[0017] The control unit 40 is located in the driver's cab 21 and controls the operation of the work machine 1 during automatic operation. For example, the control unit 40 controls the work operation of the attachment 33 and the movement of the work machine 1. Specifically, the control unit 40 controls the rotation operation of the upper rotating body 20, the travel operation of the lower traveling body 10, and the work operation of the work device 30, respectively.

[0018] The control unit 40 includes a computer. The control unit 40 may be included in a device such as a tablet or a notebook PC. The control unit 40 may be configured to control the operation of the work machine 1 by transmitting control commands to the work machine 1 via wired communication or wireless communication.

[0019] The detection unit 44 acquires information about the state of the front of the work machine 1. The detection unit 44 is positioned, for example, on the outer surface of the top wall of the operator's cab 21. The detection unit 44 according to the present invention is composed of a 3D-LiDAR that acquires three-dimensional point cloud information. The detection unit 44 may also include a stereo camera. The information acquired by the detection unit 44 is input to the control unit 40.

[0020] The GNSS 48 and the compass 50 constitute a position information acquisition unit that acquires information about the position of the upper rotating body, and the information includes the latitude, longitude, altitude of the reference position of the upper rotating body 20, and the bearing of the upper rotating body 20. The bearing of the upper rotating body 20 is also the bearing of the work device 30 attached to the upper rotating body 20. The information acquired by the position information acquisition unit is input to the control unit 40. The control unit 40 controls the movement of the work machine 1 by controlling the drive of the lower traveling body 10 based on a predetermined procedure (route) and the position information acquired by the position information acquisition unit. The control unit 40 also controls the rotation operation of the upper rotating body 20 during excavation work, etc., based on information input from a plurality of sensors provided on the upper rotating body 20.

[0021] The position at which the boom 31 is connected to the upper slewing body 20 is constant on the upper slewing body 20. Therefore, the control unit 40 can determine the position of the boom 31 with respect to the reference position of the upper slewing body 20.

[0022] The plurality of sensors include a boom angle sensor 37, an arm angle sensor 38, and an attachment angle sensor 39, which detect the inclination angles of the boom 31, the arm 32, and the attachment 33, respectively. Specifically, the boom angle sensor 37 acquires the inclination angle of the boom 31 relative to the upper slewing body 20, the arm angle sensor 38 acquires the inclination angle of the arm 32 relative to the boom 31, and the attachment angle sensor 39 acquires the inclination angle of the tip of the attachment 33 relative to the arm 32.

[0023] The memory unit 42 stores information necessary for control, and this information includes the lengths of the boom 31, the arm 32, and the attachment 33, respectively. This information, along with the position of the boom 31 and the orientation of the upper slewing body 20, which are information obtained by the control unit 40, enables the control unit 40 to control the drive of the work device 30, that is, to control the work operation of the attachment 33 based on the posture of the work device 30.

[0024] The video camera 52 captures images for monitoring the area ahead and inputs them to the control unit 40. The video camera 52 is positioned, for example, on the outer surface of the ceiling wall of the driver's cab 21.

[0025] The work machine 1 further comprises a plurality of control valves for controlling the drive of the work device 30 by the control unit 40. The plurality of control valves include a boom control valve, an arm control valve, an attachment control valve, a boom pilot pressure operating valve, an arm pilot pressure operating valve, and an attachment pilot pressure operating valve. The boom control valve is configured as a pilot-operated hydraulic switching valve and changes the pressure of the hydraulic fluid supplied to the boom cylinder 34 in accordance with the boom pilot pressure input to the boom control valve. The arm control valve is configured as a pilot-operated hydraulic switching valve and changes the pressure of the hydraulic fluid supplied to the arm cylinder 35 in accordance with the arm pilot pressure input to the arm control valve. The attachment control valve is configured as a pilot-operated hydraulic switching valve and changes the pressure of the hydraulic fluid supplied to the attachment cylinder 36 in accordance with the attachment pilot pressure input to the attachment control valve. The boom pilot pressure operating valve changes the boom pilot pressure input to the boom control valve in accordance with an electrical signal input from the control unit 40. The arm pilot pressure operating valve changes the arm pilot pressure input to the arm control valve in response to an electrical signal input from the control unit 40. The attachment pilot pressure operating valve changes the attachment pilot pressure input to the attachment control valve in response to an electrical signal input from the control unit 40.

[0026] The input / output device 54 allows an operator to input an operation to set the attachment operating speed, which is the speed at which the attachment 33 operates, and inputs an instruction signal corresponding to that operation to the control unit 40. The input / output device 54 is composed of, for example, a portable terminal such as a tablet. The input / output device 54 includes a touch panel screen, and conditions necessary for the automatic operation of the work machine 1 are input to the control unit 40 by touch operations and other operations on the screen provided by the operator. An image of the work object is displayed on the screen as needed.

[0027] The detection unit 44 functions as a height detection unit that detects the height of the work object at each of the multiple detection positions. The operator can input information for identifying the multiple detection positions into the input / output device 54 by operating the input / output device 54. The information for identifying the detection positions includes the furthest detection position and the interval between detection positions. The furthest detection position is the detection position furthest from the work machine 1 among the multiple detection positions, and the interval between detection positions is the interval between the multiple detection positions that are lined up between the furthest detection position and the work machine 1.

[0028] The input / output device 54 inputs the information set and input by the operator through the operation, namely the information for identifying the plurality of detection positions, to the control unit 40. Thus, the input / output device 54 in this embodiment functions as an input unit that inputs the information for identifying the plurality of detection positions, in this embodiment the furthest detection position and the interval between the detection positions, to the control unit 40.

[0029] The input unit is not limited to a portable device such as the tablet, but may also be an input device fixed inside the driver's cab 21, for example.

[0030] Next, the control of the work operation of the attachment 33 performed by the control unit 40 will be explained with reference to Figure 3. For convenience, only the attachment 33 (the bucket in this embodiment) of the work machine 1 is shown in Figures 3 to 6.

[0031] The memory unit 42 stores a predetermined target work trajectory (initial target work trajectory) as information necessary for the control unit 40 to control the work operation of the attachment 33. The target work trajectory is the target trajectory of the control target part of the attachment 33, in this embodiment the attachment tip 33F which is the tip of the attachment 33, as it moves on the virtual surface 62 shown in Figure 3 in conjunction with the work operation. In other words, the goal of controlling the work operation is for the attachment tip 33F to move along the target work trajectory. The virtual surface 62 is a surface that is virtually set as the surface of the ground which is the work target 60 shown in Figure 3, and Figure 3 shows a horizontal virtual surface (initial virtual surface) 62).

[0032] The storage unit that stores the target work trajectory may be a cloud server or the like. In this case, the control unit 40 may be configured to acquire information about the target work trajectory via the network when controlling the work operation of the attachment 33.

[0033] In the first embodiment described above, since the attachment 33 is a bucket used for excavation work, the storage unit 42 stores the trajectory for the movement of the bucket to hold soil and sand in the bucket during the excavation work as the target work trajectory. The storage unit 42 further stores angle control information, which is information about the angles of the boom 31, the arm 32, and the attachment 33, respectively, so that the attachment tip 33F (the tip of the bucket in this example) moves along the target work trajectory (initial target work trajectory) indicated by the solid arrow A3 in Figure 3 with respect to the virtual surface 62.

[0034] Next, the control of the work operations of the attachment 33 performed by the control unit 40 for automatic driving will be explained with reference to Figure 4. As explained earlier, the movement of the work machine 1 to the pre-designated excavation site, i.e., the site where the excavation work will be performed, is carried out by the control unit 40 controlling the drive of the lower traveling body 10 based on position information obtained from the GNSS 48, etc. The control described below is performed when the work machine 1 has already arrived at the excavation site. Figure 4 shows the work state after the first excavation has been completed at the excavation site, and more specifically, it shows the state of the actual surface 60s of the ground, which is the work target 60.

[0035] The control unit 40 determines the height of the surface 60s at multiple detection positions based on the information acquired by the detection unit 44 (3D-LiDAR in this example), which functions as the height detection unit.

[0036] The aforementioned plurality of detection positions include the furthest detection position P1 specified as described above, and at least one detection position arranged at a predetermined detection position interval d from the furthest detection position P1 toward the work machine 1, wherein the at least one detection position is only detection position P2 in the example shown in Figure 4. In other words, in Figure 4, the ground height is detected at the two detection positions P1 and P2.

[0037] Next, the control unit 40 performs a state information acquisition process to acquire state information based on the height detected at each of the plurality of detection positions P1 and P2. The state information is information about the state of the ground which is the work target 60 and is related to the working operation of the attachment 33.

[0038] Specifically, the control unit 40 identifies the lowest detection position (position P2 in this example), which is the detection position with the smallest detected height among the detection positions P1 and P2, and the height at that lowest detection position, as state information.

[0039] The control unit 40 may be configured to cause the video camera 52 to capture an image of the minimum detection position (position P2 in Figure 4) identified in this manner, and to display the image on the screen of the input / output device 54. In other words, the work machine 1 may further include a display unit (the input / output device 54 in Figure 2) that displays information about the minimum detection position P2 and its height.

[0040] Next, the control unit 40 performs a trajectory setting process to change the pre-set target work trajectory according to the state information, and in this embodiment, the height of the work target 60 at the lowest detection position P2, and an operation control process to control the work operation of the attachment 33 so that the controlled portion of the attachment 33 (attachment tip 33F in Figure 4) moves along the changed, i.e., newly set, target work trajectory, specifically the trajectory shown by the solid arrow A4 in Figure 4.

[0041] Specifically, at the start of control, an initial target work trajectory for causing the attachment 33 to perform a work operation based on the virtual surface 62 is already stored in the storage unit 42, and the control unit 40 modifies the target work trajectory based on the height at the lowest detection position P2. The control unit 40 controls the work operation of the attachment 33 so that the tip of the attachment 33F moves along the target work trajectory thus modified.

[0042] In the first embodiment, the starting position of the motion control process in the forward and backward direction is the furthest detection position P1, and the control unit 40 sets the position obtained by projecting the furthest detection position P1 vertically onto the virtual surface 62 as the actual starting position of the motion control process.

[0043] However, the starting position of the motion control process is not limited to the furthest position P1. The control unit 40 may, for example, set the starting position to the position with the smallest height among the plurality of detection positions, i.e., the lowest detection position P2.

[0044] According to the work machine 1 according to the first embodiment described above, since the target operation trajectory for scooping up the work target 60 (the ground in this example) is set based on the lowest detection position P2 among the work targets 60, the earth and sand on the ground, which is the work target 60, can be sufficiently introduced into the bucket which is the attachment 33. That is, the operation of the attachment 33 is appropriately controlled so as to enable scooping that can obtain a stable amount of excavated soil according to the shape of the surface 60s of the ground which is the work target 60.

[0045] In the present invention, the specific number of the plurality of detection positions is not limited, and the number may be 3 or more. For example, two or more detection positions may be set between the farthest detection position P1 and the work machine 1.

[0046] Next, a second embodiment of the present invention will be described with reference to FIG. 5. FIG. 5, like FIG. 4, shows the state after the first excavation is completed.

[0047] In the second embodiment, similar to the first embodiment, the height of the work target 60 at a plurality of detection positions is detected. The plurality of detection positions according to the present embodiment are three detection positions P3, P4, and P5 shown in FIG. 5, and the three detection positions P3 to P5 are arranged along a surface inclined with respect to the horizontal plane among the surfaces 60s.

[0048] The work machine according to the second embodiment also includes a control unit 40, a storage unit 42, and a detection unit like the control unit 40, the storage unit 42, and the detection unit 44 according to the first embodiment. The control unit 40 obtains the inclination of the surface 60s of the ground which is the work target 60 based on the height detected for each of the plurality of detection positions P3 to P5 as information on the state of the work target 60. That is, the state information obtained in the second embodiment is the inclination of the surface 60s. The inclination can be calculated, for example, by obtaining a straight line passing through the vicinity of the plurality of detection positions P3, P4, and P5 by the least squares method or the like using latitude, longitude, altitude, etc. as coordinate axes.

[0049] Next, the control unit 40, as part of the trajectory setting process, changes the predetermined initial target work trajectory to a new target work trajectory corresponding to the inclination specified by the height of the detection positions P3 to P5. Specifically, the control unit 40 changes the virtual surface 62 used to identify the target work trajectory from a horizontal plane shown in Figure 3 to an inclined surface corresponding to the inclination as shown in Figure 5, thereby changing the target work trajectory from the initial target work trajectory corresponding to the horizontal virtual surface 62 (the trajectory indicated by arrow A3 in Figure 3) to a target work trajectory corresponding to the inclined surface (the trajectory indicated by arrow A5 in Figure 5).

[0050] Next, the control unit 40 controls the operation of the attachment 33 as an operation control process, so that the attachment tip 33F moves along the target work trajectory (arrow A5 in Figure 5) that has been changed by the trajectory change process.

[0051] According to the work machine 1 of the second embodiment described above, the bucket, which is the attachment 33, scoops up the work object, such as soil, in accordance with the slope of the ground surface 60s, which is the work object 60. Therefore, the work operation of the attachment 33 is controlled in such a way that a sufficient amount of soil is allowed to enter the bucket, enabling scooping that yields a stable amount of excavated soil.

[0052] The shape of the work object 60 to which the control according to the second embodiment is applied is not limited to those shown in Figures 4 and 5. The control can also be applied to a work object 60 having a shape such as that shown in Figure 6, i.e., a mound of earth and sand that is higher than the surrounding ground.

[0053] In this example as well, the heights of the predetermined multiple detection positions P3, P4, and P5 are detected, and based on these heights, the control unit 40 can perform state information acquisition processing to acquire the inclination of the surface 60a of the soil pile, which is the work target 60; trajectory setting processing to set the target work trajectory to the target work trajectory shown by arrow A6 in Figure 6 based on the inclination; and motion control processing to control the work operation of the attachment 33 so that the tip of the attachment 33F moves along the target work trajectory.

[0054] Next, a working machine according to the third embodiment of the present invention will be described with reference to Figures 7 to 10.

[0055] In the first and second embodiments, the attachment 33 is a bucket, whereas in the third embodiment, the work machine includes an attachment 33 made of a lifting magnet. The lifting magnet has an adsorption surface 33s made of a magnet capable of attracting metal scraps and the like by magnetic force. Also, as with Figures 3 to 6, only the attachment 33 of the work machine is shown in Figures 7, 9 and 10.

[0056] The work machine comprises a control unit 40, a storage unit 42, and a detection unit 44 similar to those in the first embodiment. The storage unit 42 stores a predetermined initial target work trajectory for sliding the attachment 33, which consists of the lifting magnet, along a horizontal virtual surface 62 that is virtually provided as the surface of the work object 60, as shown by arrow A7 in Figure 7. This trajectory corresponds to the operation for the lifting magnet to attract the work object, and more specifically, corresponds to a trajectory for moving the suction surface 33s of the lifting magnet parallel to the surface of the work object in order to attract the work object.

[0057] In this embodiment, the work object 60 is a pile of materials, including metal scrap 64 (Figure 9) that can be attracted by magnetic force using the lifting magnet, as shown in Figures 8 and 9. For such a work object 60, as in the second embodiment, the detection unit 44 (3D-LiDAR in this example), which functions as a height detection unit, detects the height of the work object at a plurality of detection positions P6, P7, and P8, and the control unit 40 performs a state information acquisition process to acquire state information based on the height. The state information in this embodiment is also the inclination of the surface 60a of the work object 60, and the control unit 40 acquires the inclination of the surface 60a as state information based on the height of each of the plurality of detection positions P6 to P8, as in the second embodiment. The inclination can be calculated, as in the second embodiment, for example, by determining a straight line passing through the vicinity of the plurality of detection positions P3, P4, and P5 using latitude, longitude, altitude, etc. as coordinate axes, as described earlier, by the least squares method or the like.

[0058] Next, the control unit 40, similar to the second embodiment, performs a trajectory setting process to set the target work trajectory based on the virtual surface 62, which is inclined from a horizontal plane as shown in Figure 7 to an inclined surface corresponding to the inclination as shown in Figure 8, and an operation control process to slide the adsorption surface 33s of the lifting magnet, which is the controlled part of the attachment 33, along the virtual surface 62, as shown by the solid double arrow A8 in Figure 8. As a result, as shown in Figure 9, metal scraps 64 and the like included in the work object 60 can be evenly adsorbed by the lifting magnet. The sliding operation may be a reciprocating operation along the virtual surface 62, or it may be a single operation in only one direction.

[0059] On the other hand, as shown in Figure 10 as a comparative example, in a control that reciprocates the attachment 33, which is the lifting magnet attachment 33, in a position where the suction surface 33s of the lifting magnet is facing downwards regardless of the inclination of the surface 60a of the work object 60, metal scraps 64, etc. can only be attracted to a very small portion of the suction surface 33s. Therefore, the work machine according to the third embodiment can efficiently capture more metal scraps 64, etc. from the piled work material compared to the comparative example. That is, the control unit 40 can cause the lifting magnet (attachment 33) to perform a work operation that is suitable for the inclination of the surface 60a of the work object 60, which is the piled work material, and that can attract metal scraps 64, etc. with high uniformity over the entire suction surface 33s of the lifting magnet.

[0060] Next, the working machines according to the fourth and fifth embodiments of the present invention will be described with reference to Figures 11 to 14.

[0061] The work machine according to the fourth embodiment includes an attachment 33 consisting of a grapple as shown in Figures 11 and 13, and the work machine according to the fifth embodiment includes an attachment 33 consisting of a breaker as shown in Figures 12 and 14. The grapple is an attachment capable of gripping a work object 60, and the work object 60 of the grapple shown in Figure 13 is a pile of scrap or the like. The breaker is capable of crushing the work object 60 by impacting it, and the work object 60 of the breaker shown in Figure 14 is a rock or the like.

[0062] The work machines according to the fourth and fifth embodiments are each equipped with a control unit 40, a storage unit 42, and a detection unit 44 similar to those according to the first embodiment. The storage unit 42 stores, as a predetermined initial target work trajectory, an insertion trajectory for inserting the attachment 33 (the grapple shown in Figure 11 or the breaker shown in Figure 12) in the direction normal to a virtual surface 62 that is virtually given as the surface of the work object 60, as shown by arrows A11 and A12 in Figures 11 and 12, respectively. The withdrawal operation of the attachment 33 is also performed along the same trajectory (in the opposite direction to the insertion operation). The insertion trajectory can also be applied to specific attachments other than the grapple or breaker, such as a fork.

[0063] The detection unit 44 (in this example, 3D-LiDAR) functions as a height detection unit that detects the height of the work object 60 at multiple detection positions P9, P10, and P11, respectively, and the control unit 40 acquires state information based on the heights detected at the multiple detection positions P9 to P11. The state information in this embodiment is also the inclination of the surface 60a of the work object 60, similar to the second and third embodiments. This inclination can also be calculated by determining a straight line passing through the vicinity of the multiple detection positions P3, P4, and P5 using the least squares method or the like, with latitude, longitude, altitude, etc. as coordinate axes.

[0064] Next, the control unit 40 changes the target work trajectory based on the inclination. Specifically, the control unit 40 changes the horizontal virtual surface 62 shown in Figures 11 and 12 to an inclined surface viewed inclined in accordance with the inclination shown in Figures 13 and 14, and changes the target work trajectory based on the changed virtual surface 62. Specifically, it sets the target work trajectory (the insertion trajectory) in a direction along the normal direction of the inclined virtual surface 62.

[0065] Then, as shown in Figures 13 and 14, the control unit 40 controls the operation of the attachment 33 so that the controlled portion of the attachment 33 (for example, the tip of the attachment 33) moves along the target work trajectory indicated by arrows A13 and A14 in Figures 13 and 14, respectively. This control makes it possible to bring the attachment 33, which consists of the grapple and the breaker, closer to the work target 60 in a preferred direction that matches the inclination of its surface 60a.

[0066] The present invention is not limited to the embodiments described above. Modifications and improvements to the above embodiments are also included within the technical scope of the invention, which will be apparent to those skilled in the art from the claims.

[0067] For example, the trajectory setting process in each of the above embodiments involves changing a predetermined initial target work trajectory to a new target work trajectory. However, the process may also involve setting the target work trajectory directly based on the state information without first determining the initial target work trajectory.

[0068] As described above, a work machine is provided that can cause an attachment to perform appropriate work actions that are appropriate to the state of the work object. The work machine comprises an attachment capable of performing work actions to perform work, a height detection unit that detects the height of the work object at multiple positions, and a control unit that controls the work actions. The control unit performs a state information acquisition process to acquire state information, which is information about the state of the work object and related to the work actions, based on the height of the work object detected at the multiple positions, a trajectory setting process to set a target work trajectory, which is the target of the trajectory of the attachment that performs the work actions, based on the state information acquired by the state information acquisition process, and an action control process to control the work actions of the attachment so that the attachment moves along the target work trajectory.

[0069] Preferably, the work machine further includes an input unit that inputs information for identifying the plurality of detection positions to the control unit.

[0070] For example, the state information is information about the inclination of the surface of the work object, and the trajectory setting process is a process of setting the target work trajectory corresponding to the inclination.

[0071] Alternatively, the state information may be information about the height at the lowest detection position, which is the lowest detection position among the plurality of detection positions, and the trajectory setting process may be a process for setting the target work trajectory corresponding to the height at the lowest detection position.

[0072] In this case, it is preferable that the work machine further includes a display unit that displays the lowest detection position or the height at the lowest detection position.

[0073] The attachment is, for example, a bucket for excavation work, and the target work trajectory is the target trajectory to which the controlled portion of the bucket should move during the excavation work.

[0074] The attachment may be a lifting magnet capable of magnetically attracting objects included in the workpiece. In this case, it is preferable that the target work trajectory is the trajectory of the lifting magnet when it performs an attraction operation that enables it to attract the objects.

[0075] The attachment may be selected from among a grapple, a fork, and a breaker. In this case, the work track is preferably a track for inserting the attachment into the work object.

Claims

1. A work machine comprising: an attachment capable of performing work operations for performing work on a work object; a height detection unit for detecting the height of the work object at a plurality of detection positions; and a control unit for controlling the work operations of the attachment, wherein the control unit performs: a state information acquisition process for acquiring state information which is information about the state of the work object and related to the work operations based on the heights detected at the plurality of detection positions; a trajectory setting process for setting a target work trajectory which is a target for the trajectory of the attachment performing the work operations based on the state information; and an operation control process for controlling the work operations of the attachment so that the attachment moves along the target work trajectory.

2. A work machine according to claim 1, further comprising an input unit for inputting information for identifying the plurality of detection positions to the control unit.

3. A work machine according to claim 1, wherein the state information is information about the inclination of the surface of the work object, and the trajectory setting process is a process of setting the target work trajectory corresponding to the inclination.

4. A work machine according to claim 1, wherein the state information is information about the height at the lowest detection position, which is the lowest detection position of the work object among the plurality of detection positions, and the trajectory setting process is a process of setting the target work trajectory corresponding to the height at the lowest detection position.

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