Working machinery

Abstract

The present invention provides a work machine that, while appearing drivable from the outside, can ensure vehicle stability when traveling on terrain where vehicle stability may be compromised during operation. [Solution] The control device 40 includes a tilt index calculation unit 45 that calculates a tilt index of the area near the vehicle body 500 when the maximum difference in the axial direction of the pivot axis 120 of each surface position in the area near the vehicle body 500 falls below a predetermined first threshold; a tilt index holding unit 46 that holds the first tilt index, which is the tilt index calculated by the tilt index calculation unit 45, while the state in which the maximum difference is below the first threshold continues; and a vehicle body tilt fluctuation determination unit 47 that calculates a second tilt index, which is the tilt index of the vehicle body 3, and instructs the stabilization support device 55 to perform support operations to ensure the stability of the vehicle body 3 when the difference between the first tilt index held by the tilt index holding unit 46 and the second tilt index of the vehicle body 3 becomes greater than or equal to a predetermined second threshold.

Description

Technical Field

[0001] The present invention relates to a working machine such as a hydraulic excavator.

Background Art

[0002] A hydraulic excavator, which is a representative example of a working machine, includes a lower traveling body, an upper revolving body that is rotatably mounted on the lower traveling body and forms a vehicle body together with the lower traveling body, and a multi-articulated working device mounted on the revolving body. The working device has a boom rotatably attached to the upper revolving body, an arm rotatably attached to the boom, and a bucket rotatably attached to the arm. Therefore, the posture and the center of gravity position of the working machine change according to the direction of the upper revolving body and the angles of the boom and the like.

[0003] Such a working machine may have reduced vehicle body stability when affected by the ground during traveling. As a prior art document that discloses a technique for ensuring the traveling stability of a working machine during traveling, for example, there is Patent Document 1. Patent Document 1 discloses a technique that includes an imaging device and a distance sensor that acquire information on the surrounding ground, and a controller, and determines the traveling stability when the excavator travels on the ground based on the ground information acquired by the imaging device and the distance sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Patent Document 1 describes a system that uses image information of the area around the excavator to determine the degree of danger when the excavator travels on the ground, and displays this degree of danger to assist the operator. However, it is difficult to accurately determine the degree of danger from the appearance of the ground, and even on ground that is determined to have a low degree of danger, the stability of the vehicle may decrease if the ground is soft or if the terrain changes due to the weight of the work machine while it is traveling.

[0006] This invention has been made in view of the above-mentioned problems, and its purpose is to provide a work machine that can ensure the stability of the vehicle body when traveling on terrain that, although appearing to be drivable from the outside, may impair the stability of the vehicle body while traveling. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a work machine comprising: a lower traveling body; an upper rotating body rotatably attached to the lower traveling body around a pivot axis and constituting a vehicle body together with the lower traveling body; a work device attached to the upper rotating body; an operating device for operating the lower traveling body, the upper rotating body and the work device; an attitude detection device for detecting the attitude of the vehicle body; a terrain information acquisition device for acquiring terrain information around the vehicle body; and a control device for controlling the operation of the lower traveling body, the upper rotating body and the work device in accordance with the operation of the operating device, wherein the work machine is further equipped with a stabilization support device that performs support operations to ensure the stability of the vehicle body, the control device comprising: a ground area estimation unit for estimating the ground area from the terrain information acquired by the terrain information acquisition device, and from the ground area, The system includes: a vehicle proximity region extraction unit that extracts a vehicle proximity region including the region of the lower vehicle and the region near it; a tilt index calculation unit that calculates a tilt index for the vehicle proximity region when the maximum difference in the axial direction of the pivot axis of each surface position in the vehicle proximity region becomes less than or equal to a predetermined first threshold; a tilt index holding unit that holds a first tilt index, which is the tilt index calculated by the tilt index calculation unit, while the state in which the maximum difference is less than or equal to the first threshold continues; and a vehicle tilt fluctuation determination unit that calculates a second tilt index, which is the tilt index of the vehicle body, from the posture of the work machine detected by the posture detection device, and instructs the stabilization support device to perform the support operation when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to a predetermined second threshold. [Effects of the Invention]

[0008] According to the present invention, it is possible to ensure the stability of a work machine when it travels on terrain that, while appearing drivable from the outside, may compromise the stability of the machine during travel. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of a hydraulic excavator. [Figure 2] This is a diagram illustrating the configuration of the hydraulic system and control system installed in a hydraulic excavator. [Figure 3] This is a functional block diagram of the control device according to the first embodiment. [Figure 4] This is a side view showing the reference coordinate system along with the hydraulic excavator. [Figure 5] This is a rear view showing the reference coordinate system along with the hydraulic excavator. [Figure 6] This is a plan view showing the reference coordinate system along with the hydraulic excavator. [Figure 7] This diagram shows the reference coordinate system and grid map. [Figure 8] This is a flowchart showing the extraction process of the area near the moving object. [Figure 9] This flowchart shows the processes related to the stabilization support function. [Figure 10] This is a side view of a hydraulic excavator in a situation where the slope differs from the slope anticipated in advance due to the terrain. [Figure 11] This figure shows the region near the vehicle, including the slope surface. [Figure 12] This figure shows an example of the operation of the notification device according to the first embodiment. [Figure 13] This is a functional block diagram of the control device according to the second embodiment. [Figure 14] This figure shows the movement of a hydraulic excavator according to the second embodiment. [Figure 15] This figure shows an example of the operation of the notification device according to the second embodiment. [Figure 16] This is a diagram illustrating the configuration of the remote control system. [Figure 17] This diagram shows a hydraulic excavator loading a dump truck. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, as a working machine, a hydraulic excavator equipped with a bucket as a working tool (attachment) at the tip of a working device (front working device) will be exemplified, but the present invention may also be applied to a working machine equipped with an attachment other than a bucket. Further, as long as it has an articulated working device configured by connecting a plurality of front members (working tools, booms, arms, etc.) on a rotatable structure, it can also be applied to working machines other than hydraulic excavators.

[0011] Also, in the following description, when there are a plurality of identical components, a lowercase letter of the alphabet may be added to the end of the reference numeral, but the lowercase letter of the alphabet may be omitted and the plurality of components may be collectively represented. For example, when there are three identical pumps 190a, 190b, and 190c, they may be collectively referred to as pump 190.

Example

[0012] FIG. 1 is a diagram schematically showing the configuration of a hydraulic excavator 1.

[0013] The hydraulic excavator 1 performs an operation of excavating an excavation target surface such as the ground (excavation operation) and an operation of loading excavated materials such as earth and sand into a loading machine such as a dump truck 200 (shown in FIG. 17) (loading operation). In this loading operation, the hydraulic excavator 1 performs an operation of transporting the excavated material above the loading platform of the loading machine (transport operation) and an operation of discharging the excavated material onto the loading platform of the loading machine (discharge operation). The hydraulic excavator 1 includes an articulated front working device 2 that holds an object and rotates in the vertical or front-rear direction, and a vehicle body 3 on which the front working device 2 is mounted. Note that the front working device 2 is an example of a working device provided in the working machine.

[0014] The vehicle body 3 comprises a lower traveling body 5 that is driven by hydraulic actuators, namely a right traveling hydraulic motor 4a and a left traveling hydraulic motor 4b, and an upper rotating body 7 that is attached to the upper part of the lower traveling body 5 via a rotating device (not shown) and rotates by a rotating hydraulic motor 6 (shown in Figure 2), which is a hydraulic actuator of the rotating device. The lower traveling body 5 includes a pair of left crawlers 21a and right crawlers 21b. In this embodiment, the left crawler 21a and right crawler 21b are collectively referred to as crawlers 21.

[0015] The front working device 2 is a multi-jointed working device composed of multiple front members attached to the front of the upper slewing body 7. The front working device 2 includes a boom 8 that is rotatably connected vertically to the front of the upper slewing body 7, an arm 9 that is rotatably connected vertically to the tip of the boom 8, and a bucket 10 that is rotatably connected vertically to the tip of the arm 9. A counterweight is provided at the rear of the upper slewing body 7.

[0016] The boom 8 is connected to the upper slewing body 7 by a boom pin 8a (not shown) and rotates by the extension and retraction of a boom cylinder 11, which is a hydraulic actuator. The arm 9 is connected to the tip of the boom 8 by an arm pin 9a and rotates by the extension and retraction of an arm cylinder 12, which is a hydraulic actuator. The bucket 10 is connected to the tip of the arm 9 by a bucket pin 10a and a bucket link 16 and rotates by the extension and retraction of a bucket cylinder 13, which is a hydraulic actuator.

[0017] A boom angle sensor 14 is attached to the boom pin 8a to detect the rotation angle of the boom 8 relative to the vehicle body 3 (upper slewing body 7). An arm angle sensor 15 is attached to the arm pin 9a to detect the rotation angle of the arm 9 relative to the boom 8. A bucket angle sensor 17 is attached to the bucket link 16 to detect the rotation angle of the bucket 10 relative to the arm 9.

[0018] Furthermore, the method for obtaining the rotation angles of the boom 8, arm 9, and bucket 10 is not limited to the means described above. They may also be obtained by detecting the angles of the boom 8, arm 9, and bucket 10 with respect to a reference plane such as a horizontal plane using an inertial measurement unit (IMU) and converting them into rotation angles. Alternatively, the rotation angles of the boom 8, arm 9, and bucket 10 may be obtained by detecting the strokes of the boom cylinder 11, arm cylinder 12, and bucket cylinder 13 using stroke sensors and converting them into rotation angles.

[0019] The upper rotating body 7 is equipped with an inclination angle sensor 18 that detects the inclination angle of the vehicle body 3 with respect to a reference plane such as a horizontal plane. The rotating device between the lower traveling body 5 and the upper rotating body 7 is equipped with a rotation angle sensor 19 that detects the rotation angle of the upper rotating body 7 with respect to the lower traveling body 5. The inclination angle of the lower traveling body 5 may be obtained by converting the value of the inclination angle sensor 18 attached to the upper rotating body 7 using the value of the rotation angle sensor 19, or it may be obtained from the inclination angle sensor 18 attached to the lower traveling body 5.

[0020] Here, the boom angle sensor 14, arm angle sensor 15, bucket angle sensor 17, tilt angle sensor 18, and slewing angle sensor 19 constitute an attitude detection device 53 that detects the rotation angles of each part of the front work device 2 and the slewing angle of the upper slewing body 7.

[0021] In the driver's cab 71 located in the upper slewing body 7, there is an operating device for operating multiple hydraulic actuators 4a, 4b, 6, 11-13. Specifically, the operating device includes a right travel lever 23a for operating the right travel hydraulic motor 4a, a left travel lever 23b for operating the left travel hydraulic motor 4b, a right operating lever 22a for operating the boom cylinder 11 and bucket cylinder 13, and a left operating lever 22b for operating the arm cylinder 12 and slewing hydraulic motor 6. In this embodiment, the right travel lever 23a and the left travel lever 23b are collectively referred to as the travel lever 23, and the right travel lever 23a, left travel lever 23b, right operating lever 22a, and left operating lever 22b are collectively referred to as the operating levers 22 and 23. For example, electric levers are used for the operating levers 22 and 23.

[0022] Furthermore, an ambient information acquisition device 54 (terrain information acquisition device) is mounted on the upper rotating body 7, for example, on top of the operator's cab 71, to acquire information about objects (including terrain and ground surface) around the hydraulic excavator 1. The ambient information acquisition device 54 may be, for example, a LiDAR (Light Detection and Ranging) or a stereo camera. Multiple ambient information acquisition devices 54 may be mounted on the hydraulic excavator 1. Alternatively, the information acquired by an ambient information acquisition device 54 installed at the work site rather than on the hydraulic excavator 1 may be acquired via a communication device.

[0023] Figure 2 is a diagram showing the configuration of the hydraulic system and control system installed on hydraulic excavator 1.

[0024] As shown in Figure 2, the engine 103, which is the prime mover mounted on the upper slewing body 7, drives the hydraulic pump 102 and the pilot pump 104. The control device 40 controls the rotational movement of the front work device 2, the travel movement of the lower traveling body 5, and the slewing movement of the upper slewing body 7 according to the operation information (operation amount and direction) of the operation levers 22 and 23 by the operator. Specifically, the control device 40 detects the operation information (operation amount and direction) of the operation levers 22 and 23 by the operator using operation detection devices 52a to 52f, and outputs control commands to the electromagnetic proportional valves 51a to 51l according to the detected operation information. The electromagnetic proportional valves 51a to 51l are located on the pilot line 100 and operate when a control command is input from the control device 40, outputting pilot pressure to the flow control valve 101 and operating the flow control valve 101.

[0025] The flow control valve 101 controls the pressurized oil supplied from the hydraulic pump 102 to the swing hydraulic motor 6, arm cylinder 12, boom cylinder 11, bucket cylinder 13, travel right hydraulic motor 4a, and travel left hydraulic motor 4b, respectively, according to the pilot pressure from the electromagnetic proportional valves 51a to 51l.

[0026] The boom cylinder 11, arm cylinder 12, and bucket cylinder 13 extend and retract using supplied pressurized oil, respectively, to rotate the boom 8, arm 9, and bucket 10. This changes the position and orientation of the bucket 10. The slewing hydraulic motor 6 rotates using supplied pressurized oil to slewing the upper slewing body 7. The right travel hydraulic motor 4a and the left travel hydraulic motor 4b rotate using supplied pressurized oil to move the lower travel body 5. Even when the operator does not operate the control levers 22 and 23, the control device 40 can activate the electromagnetic proportional valves 51a to 51l and the flow control valve 101 to drive the hydraulic actuators 4a, 4b, 6, 11 to 13. Furthermore, even when the operator operates the control levers 22 and 23, the control device 40 can limit the amount of operation performed by the operator.

[0027] Figure 3 is a functional block diagram showing the processing functions of the control device 40 along with their related configurations. Figure 4 is a side view showing the reference coordinate system together with the hydraulic excavator, Figure 5 is a rear view, and Figure 6 is a top view.

[0028] The control device 40, although not shown in the diagram, is a computer in which a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), and external I / F (Interface) are interconnected via a bus. The external I / F of the control device 40 is connected to an electromagnetic proportional valve 51, an operation detection device 52, an attitude detection device 53, an ambient information acquisition device 54 (terrain information acquisition device), a notification device 55 (stabilization support device), and a storage device (e.g., a hard disk drive or high-capacity flash memory) which are not shown in the diagram.

[0029] The notification device 55 is a device that notifies the operator of information from the control device 40. The notification device 55 is, for example, a display. The notification device 55 may also be equipped with a speaker and provide notifications using sound.

[0030] In Figure 3, the control device 40 includes a coordinate transformation unit 41, an object detection unit 42, a ground area estimation unit 43, a vehicle proximity area extraction unit 44, a tilt index calculation unit 45, a tilt index holding unit 46, and a vehicle tilt fluctuation determination unit 47.

[0031] The control device 40 is pre-set with a reference coordinate system 300 that specifies the position and orientation of the components of the hydraulic excavator 1. In this embodiment, the reference coordinate system 300 is defined as a right-handed coordinate system with its origin at the point where the pivot axis 120 of the upper rotating body 7 intersects with the ground contact surface G of the lower traveling body 5, as shown in Figures 4, 5, and 6. In the reference coordinate system 300, the forward direction of the lower traveling body 5 is defined as the positive direction of the X axis. In the reference coordinate system 300 in this embodiment, the direction in which the pivot axis 120 extends upward is defined as the positive direction of the Z axis. In the reference coordinate system 300 in this embodiment, the left side is defined as the positive direction of the Y axis, which is perpendicular to both the X and Z axes.

[0032] Furthermore, in the reference coordinate system 300 of this embodiment, the rotation angle of the upper slewing body 7 is defined as 0 degrees when the front working device 2 is parallel to the X axis. When the rotation angle of the upper slewing body 7 is 0 degrees, the operating plane of the front working device 2 is parallel to the XZ plane, the upward movement direction of the boom 8 is in the positive direction of the Z axis, and the dumping direction of the arm 9 and bucket 10 is in the positive direction of the X axis.

[0033] Furthermore, the inclination of the lower vehicle 5 in the longitudinal direction relative to the direction of gravity is defined as the lower vehicle pitch angle θlp, the inclination in the lateral direction is defined as the lower vehicle roll angle θlr, the inclination of the upper rotating body in the longitudinal direction is defined as the upper rotating body pitch angle θup, and the inclination angle in the lateral direction is defined as the upper rotating body roll angle θur. When the rotation angle is 0 degrees, the pitch angle θlp of the lower vehicle coincides with the pitch angle θup of the upper rotating body, and the roll angle θlr of the lower vehicle coincides with the roll angle θur of the upper rotating body. Figures 4 and 5 show the situation where the rotation angle is 0 degrees and the pitch angle θlp of the lower vehicle coincides with the pitch angle θup of the upper rotating body, and the roll angle θlr of the lower vehicle coincides with the roll angle θur of the upper rotating body.

[0034] The coordinate transformation unit 41 converts the point cloud data obtained from the surrounding information acquisition device 54 into point cloud data in the reference coordinate system 300, using the position and orientation of the surrounding information acquisition device 54 relative to the hydraulic excavator 1 and the rotation angle of the upper rotating body 7.

[0035] The object detection unit 42 uses point cloud data in the reference coordinate system 300 to detect objects with height that exist around the hydraulic excavator 1. The objects to be detected here include other work machines and rocks, and are any objects that obstruct the movement of the hydraulic excavator 1.

[0036] The ground area estimation unit 43 estimates the area that constitutes the ground around the hydraulic excavator 1 (ground area) by removing the area where an object has been detected from around the hydraulic excavator 1. The ground area also includes substantially planes with a slope different from the substantially plane on which the hydraulic excavator 1 is located. For example, if the substantially plane on which the hydraulic excavator 1 is located is a substantially horizontal plane (a substantially plane that is not inclined with respect to the direction of gravity), then the slope surface connected to that substantially horizontal plane (a substantially plane that is inclined with respect to the direction of gravity) is also included in the ground area.

[0037] The object detection unit 42 and the ground area estimation unit 43 may perform processing on grid data 400, which is obtained by dividing the area surrounding the hydraulic excavator 1 into a grid, with the reference coordinate system 300 as the origin, as shown in Figure 7. This reduces the computational load on the control device 40 and allows for centralized management of ground area information using grid data 400.

[0038] The vehicle proximity region extraction unit 44 extracts the vehicle proximity region 500, which is the region encompassing the lower vehicle 5 and its vicinity, from the ground region estimated by the ground region estimation unit 43. The size of the vehicle proximity region 500 is, for example, the range in which the lower vehicle 5 can move during the calculation cycle of the control device 40. The vehicle proximity region 500 is shown by a dashed line in Figure 7. The vehicle proximity region extraction unit 44 also determines whether the vehicle proximity region 500 is a single substantially plane. Specifically, it is determined that the vehicle proximity region 500 is a single substantially plane if the maximum difference in the direction of the pivot axis 120 of each surface position of the vehicle proximity region 500 is less than or equal to a predetermined threshold (first threshold).

[0039] When the vehicle proximity region extraction unit 44 determines that the vehicle proximity region 500 is a single substantially flat plane, the inclination index calculation unit 45 calculates the sum of the squares of the pitch angle and roll angle of the lower vehicle 5 as the inclination index of the vehicle proximity region 500. Note that the inclination index can be any value that indicates the magnitude of the inclination, and is not limited to the sum of the squares of the pitch angle and roll angle of the lower vehicle 5.

[0040] The inclination index holding unit 46 determines that the lower traveling body 5 is moving on a substantially plane having the same inclination index while the hydraulic excavator 1 is moving, that is, while the crawler 21 is being driven, as long as the traveling body proximity region extraction unit 44 determines that the traveling body proximity region 500 is a single substantially plane, and continues to hold the inclination index of the traveling body proximity region 500 calculated by the inclination index calculation unit 45 at the time it was first determined that the traveling body proximity region 500 is a single substantially plane.

[0041] The vehicle body tilt fluctuation determination unit 47, when the tilt index holding unit 46 holds the tilt index of the area 500 near the vehicle body, calculates the sum of the squares of the pitch angle and roll angle of the lower vehicle body 5 from the attitude detection device 53 as the tilt index of the vehicle body 3 (second tilt index), calculates the difference between the held tilt index of the area 500 near the vehicle body (first tilt index) and the second tilt index, and if the difference is greater than or equal to a predetermined threshold (second threshold), it determines that a tilt of the lower vehicle body 5 different from that predicted from the terrain beforehand has occurred, and activates the stabilization support function.

[0042] Next, the notification process in this embodiment will be explained using the flowcharts shown in Figures 8 and 9. Figure 8 is a flowchart showing the extraction process of the area 500 near the vehicle, and Figure 9 is a flowchart showing the process related to the stabilization support function.

[0043] First, in Figure 8, in step S1, the coordinate transformation unit 41 transforms the 3D point cloud data acquired by the surrounding information acquisition device 54 into the reference coordinate system 300 of the hydraulic excavator 1.

[0044] In step S2, the object detection unit 42 detects objects around the hydraulic excavator 1.

[0045] In step S3, the ground area estimation unit 43 estimates the area that will be the ground around the hydraulic excavator 1.

[0046] In step S4, the vehicle proximity region extraction unit 44 extracts the vehicle proximity region 500, which is the region in the vicinity of the lower vehicle 5.

[0047] In step S5, the vehicle proximity region extraction unit 44 determines whether the vehicle proximity region 500 is a single substantially plane. If it is determined to be a single substantially plane, the process proceeds to step S6. If it is not determined to be a single substantially plane, the process proceeds to step S1.

[0048] In step S6, the inclination index calculation unit 45 calculates the inclination index of the area 500 near the vehicle.

[0049] In steps S7 and S8, as long as the area 500 near the vehicle is a single substantially plane, the inclination index of the area 500 near the vehicle is held by the inclination index holding unit 46, and the process proceeds to step S7. If the area 500 near the vehicle is no longer a single substantially plane, the inclination index of the area 500 near the vehicle is discarded, and the process proceeds to step S9. The extraction process of the area 500 near the vehicle and the determination process of whether or not the area 500 near the vehicle is a single substantially plane are continued.

[0050] In step S9, the inclination indicator holding unit 46 discards the inclination indicator in the area 500 near the vehicle.

[0051] In Figure 9, in step S100, the vehicle body tilt fluctuation determination unit 47 determines whether the tilt index of the area 500 near the vehicle body is maintained. If it is maintained, the process proceeds to step S101. If it is not maintained, the process ends.

[0052] In step S101, the vehicle body tilt change determination unit 47 calculates the sum of the squares of the pitch angle and roll angle of the lower traveling body 5 (second tilt index).

[0053] In step S102, the system compares whether the difference between the inclination index of the area 500 near the held vehicle (first inclination index) and the calculated sum of the squares of the pitch angle and roll angle of the lower vehicle 5 (second inclination index) is greater than or equal to the second threshold. If it is greater than or equal to the second threshold, the system proceeds to step S103; otherwise, the process ends.

[0054] In step S103, the stabilization support function is activated. In this embodiment, the stabilization support function is a notification function provided by the notification device 55.

[0055] This explains the effects of performing this type of processing.

[0056] As shown in Figure 10, when the hydraulic excavator 1 is traveling on terrain that appears to be a single, nearly flat plane (terrain where the inclination of the hydraulic excavator 1 is not expected to change), if the lower traveling body 5 actually reaches that terrain, the inclination of the hydraulic excavator 1 may change due to reasons such as the terrain being soft or prone to collapse, potentially reducing the stability of the hydraulic excavator 1. In this embodiment, if the inclination of the hydraulic excavator 1 that is predicted to occur based on prior terrain information differs from the inclination that actually occurs on the hydraulic excavator 1, the operator is notified, making it easy for the operator to notice the inclination of the hydraulic excavator 1 and ensuring the stability of the hydraulic excavator 1. Even if the absolute values ​​of the pitch angle and roll angle of the hydraulic excavator 1 with respect to gravity are small, it is possible to notify the operator if they differ from the inclination angle predicted from prior terrain information.

[0057] Furthermore, by using the sum of the squares of the pitch angle and roll angle of the lower vehicle 5 as the inclination index, it is possible to handle cases where turning is performed on a sloping surface or when the orientation of the lower vehicle changes relative to the surface on the slope during travel. The lower vehicle pitch angle θlp, lower vehicle roll angle θlr, upper turning body pitch angle θup, upper turning body roll angle θur, and turning angle θswg have the following relationships.

[0058]

number

[0059]

number

[0060] Squaring both sides of the two equations above and adding the left sides together and the right sides together,

[0061]

number

[0062] Thus, it can be seen that the sum of squares is preserved regardless of the turning angle θswg. Here, the turning angle θswg can also be considered as the orientation of the lower vehicle 5 with respect to the slope surface. In other words, the sum of squares of the pitch angle θlp and roll angle θlr of the lower vehicle 5 is preserved regardless of the orientation of the lower vehicle 5 with respect to the slope surface.

[0063] If only the pitch angle θlp and roll angle θlr of the lower vehicle 5 are considered, it is not possible to distinguish whether a change in these angles is due to a change in the orientation of the lower vehicle 5 relative to the slope surface, or due to a change in the terrain as a result of its movement. However, if only the orientation of the lower vehicle 5 changes, the sum of the squares of the pitch angle θlp and roll angle θlr of the lower vehicle 5 is preserved, so it is possible to distinguish between a change in the orientation of the lower vehicle 5 relative to the slope surface and a change in the shape of the terrain.

[0064] Figure 11 shows the case where the hydraulic excavator 1 is positioned in a nearly horizontal plane and the slope surface is included in the area 500 near the traveling body. Figure 11(a) shows a side view, and Figure 11(b) shows the grid data 400 in that case. In the grid data 400 in Figure 11(b), the shaded area represents the slope surface.

[0065] As shown in Figure 11, if the area 500 near the vehicle body includes a slope surface that is presumed to be the ground but has a different incline than the approximately plane on which the lower vehicle body 5 is located, the area 500 near the vehicle body is not determined to be a single approximately plane. Therefore, the incline index of the area 500 near the vehicle body is not maintained, and the stabilization support function does not operate. With this configuration, the stabilization support function will not operate when the lower vehicle body 5 enters a slope surface or enters an approximately horizontal surface from a slope surface. In other words, if a change in the incline of the lower vehicle body 5 is expected from the terrain beforehand, the stabilization support function will not operate, thereby reducing the operator's discomfort.

[0066] Figure 12 shows an example of the operation of the notification device 55. Regardless of the pitch angle or roll angle of the hydraulic excavator 1, if a slope different from the slope predicted from the terrain occurs, a notification is issued.

[0067] Furthermore, the notification device 55 may notify the operator of the results of the extraction of the area 500 near the vehicle body by the vehicle body proximity area extraction unit 44. Since the extraction of the area 500 near the vehicle body is performed on an area presumed to be the ground, this configuration allows the operator to easily understand that there are no obstacles near the lower vehicle body 5.

[0068] Furthermore, the notification device 55 may also notify whether or not the tilt indicator holding unit 46 is holding the tilt indicator of the vehicle body 3. This allows the operator to know in advance whether or not the stabilization support function is likely to operate.

[0069] (summary) In the first embodiment, a hydraulic excavator 1 (working machine) comprises a lower traveling body 5, an upper rotating body 7 that is rotatably mounted on the lower traveling body 5 around a pivot axis and forms a vehicle body together with the lower traveling body 5, a working device 2 attached to the upper rotating body 7, operating devices 22, 23 for operating the lower traveling body 5, the upper rotating body 7 and the working device 2, an attitude detection device 53 for detecting the attitude of the vehicle body 3, a terrain information acquisition device 54 for acquiring terrain information around the vehicle body 3, and a control device 40 that controls the operation of the lower traveling body 5, the upper rotating body 7 and the working device 2 in response to the operation of the operating levers 22, 23 (operating devices), and further comprises a stabilization support device 55 that performs support operations to ensure the stability of the vehicle body 3, and the control device 40 includes a ground area estimation unit 43 that estimates the ground area from the terrain information acquired by the terrain information acquisition device 54, and the ground area The system includes: a vehicle body proximity region extraction unit 44 that extracts a vehicle body proximity region 500 from the area, including the region of the lower vehicle body 5 and the region near it; a tilt index calculation unit 45 that calculates a tilt index of the vehicle body proximity region 500 when the maximum difference in the axial direction of the pivot axis 120 of each surface position in the vehicle body proximity region 500 becomes less than or equal to a predetermined first threshold; a tilt index holding unit 46 that holds the first tilt index, which is the tilt index calculated by the tilt index calculation unit 45, while the state in which the maximum difference remains less than or equal to the first threshold continues; and a vehicle body tilt fluctuation determination unit 47 that calculates a second tilt index, which is the tilt index of the vehicle body 3, from the attitude of the hydraulic excavator 1 detected by the attitude detection device 53, and instructs the stabilization support device 55 to perform the support operation when the difference between the first tilt index held by the tilt index holding unit 46 and the second tilt index of the vehicle body 3 becomes greater than or equal to a predetermined second threshold.

[0070] According to the first embodiment configured as described above, when the vehicle body 3 deviates from the inclination index of the vehicle body 3 while traveling in a single, substantially flat area 500 near the vehicle body, the stabilization support device 55 assists in stabilizing the vehicle body 3. This makes it possible to ensure the stability of the vehicle body 3 when the hydraulic excavator 1 travels over terrain that appears drivable externally but where the stability of the vehicle body 3 may be compromised during travel.

[0071] Furthermore, the tilt index calculation unit 45 according to the first embodiment calculates the sum of the squares of the pitch angle θlp and roll angle θlr of the lower traveling body 5 as the tilt index of the region 500 near the traveling body, and the vehicle body tilt fluctuation determination unit 47 calculates the sum of the squares of the pitch angle θlp and roll angle θlr of the lower traveling body 5 as the tilt index of the vehicle body 3. This makes it possible to distinguish and detect tilt fluctuations of the vehicle body 3 caused by deformation of the ground from tilt fluctuations of the vehicle body 3 caused by a change in the orientation of the lower traveling body 5. Moreover, by calculating the sum of the squares of the pitch angle θup and roll angle θur of the upper rotating body 7, the sum of the squares of the pitch angle θlp and roll angle θlr of the lower traveling body 5 can be calculated, making it possible to install the attitude detection device 53 together with the control device 40 on the upper rotating body 7. As a result, it becomes unnecessary to run the wiring for the attitude detection device 53 through the rotating device to the lower traveling body 5.

[0072] Furthermore, in the first embodiment, the hydraulic excavator 1 is equipped with a driver's cab 71 located on the upper rotating body 7, and the stabilization support device 55 is equipped with a notification device 55 located in the driver's cab 71. The vehicle body tilt fluctuation determination unit 47 instructs the notification device 55 to notify that an unexpected tilt has occurred in the vehicle body 3 when the difference between the first tilt index held by the tilt index holding unit 46 and the second tilt index of the vehicle body 3 exceeds the second threshold. This makes it possible to prompt the operator to take action to ensure the stability of the vehicle body 3 when an unexpected tilt occurs in the vehicle body 3.

[0073] Furthermore, the notification device 55 according to the first embodiment displays the area 500 near the vehicle body extracted by the vehicle body proximity area extraction unit 44. This allows the operator to easily understand that there are no obstacles near the lower vehicle body 5.

[0074] Furthermore, the notification device 55 according to the first embodiment notifies whether or not the first tilt indicator is being held by the tilt indicator holding unit 46. This allows the operator to know in advance whether or not the stabilization support function is likely to operate. [Examples]

[0075] In a second embodiment of the present invention, a configuration is described that includes a function to intervene in the operation of the operating devices 22 and 23 as a stabilization support function. Note that the same parts as in the first embodiment will not be described.

[0076] Figure 13 is a functional block diagram of the control device 40 in this embodiment. Compared to the first embodiment (shown in Figure 3), an operation control unit 48 has been added. Furthermore, the electromagnetic proportional valve 51 and the notification device 55 are configured to receive commands from the operation control unit 48.

[0077] The motion control unit 48 calculates the difference between the inclination index of the area near the held traveling body and the sum of the squares of the pitch angle and roll angle of the lower traveling body 5 from the attitude detection device 53, using the vehicle body tilt fluctuation determination unit 47. If this difference exceeds a predetermined threshold (second threshold), the operation of the hydraulic excavator 1 is restricted. Here, the second threshold in this embodiment is a larger value than the threshold (second threshold) used to determine notification in the first embodiment.

[0078] The operation controlled by the motion control unit 48 is, for example, the travel operation of the hydraulic excavator 1. When the difference between the inclination index of the area near the held travel body and the sum of the squares of the pitch angle and roll angle of the lower travel body 5 from the attitude detection device 53 exceeds a second threshold, the operation control limits the amount of operation. In other words, the amount of operation of the travel lever 23 is limited.

[0079] The operation controlled by the motion control unit 48 is, for example, the operation of the front working device 2 of the hydraulic excavator 1. When the difference between the inclination index of the area near the held vehicle and the sum of the squares of the pitch angle and roll angle of the lower vehicle 5 from the attitude detection device 53 exceeds a second threshold, the boom 8 is automatically lowered without operator intervention, the position of the bucket 10 is lowered, and the hydraulic excavator 1 is made easier to support.

[0080] The operation controlled by the motion control unit 48 is the rotational movement of the upper slewing body 7 of the hydraulic excavator 1. For example, as shown in Figure 14, suppose that the upper slewing body 7 rotates 90 degrees to the right and the lower traveling body 5 is moving forward, and the difference between the inclination index of the area near the traveling body being held and the sum of the squares of the pitch angle and roll angle of the lower traveling body 5 from the attitude detection device 53 exceeds a second threshold, and as a result of comparing the roll angle and pitch angle of the lower traveling body 5 before and after exceeding the second threshold, it is determined that the lower traveling body 5 has a downward-sloping pitch angle that is not expected from the terrain information. At this time, if the center of gravity of the upper slewing body 7 is on the opposite side of the front working device (counterweight side), the rotational movement of the upper slewing body 7 to the right is restricted. The center of gravity can be calculated based on the information from the attitude detection device 53. Also, as shown in Figure 15, the operation controlled by the motion control unit 48 may be notified by the notification device 55.

[0081] Furthermore, as shown in Figure 16, the hydraulic excavator 1 may be configured to be remotely controlled by a remote control device 600 located away from the hydraulic excavator 1 and configured to transmit operation commands to the control device 40, a wireless transmitter 601 that transmits operation commands from the remote control device 600, and a wireless receiver 602 that receives commands transmitted from the wireless transmitter 601. In this case, the remote control device 600 may generate a reaction force in the opposite direction to the operating direction when the operation control unit 48 intervenes in the operation of the remote control device 600.

[0082] In extracting the area near the vehicle body 500, the area near the vehicle body 500 may be extracted in such a way that the bench edge 211 is not included in the area near the vehicle body 500. Here, the bench edge 211 is the edge of the bench 210 on which the hydraulic excavator 1 is positioned when the hydraulic excavator 1 is performing loading work onto the dump truck 200, as shown in Figure 17. Since the area near the vehicle body 500 does not include the area beyond the bench edge 211, when the bench edge 211 is near the lower vehicle body 5, displaying the extraction result of the area near the vehicle body 500 makes it easy for the operator to notice the presence of the bench edge 211.

[0083] (summary) In the second embodiment, the stabilization support device 48 has an operation control unit 48 provided in the control device 40 as a function to intervene in the operation of the operating devices 22 and 23, and the vehicle body tilt fluctuation determination unit 47 instructs the operation control unit 48 to intervene in the operation of the operating devices 22 and 23 so as to suppress the tilt fluctuation of the vehicle body 3 when the difference between the first tilt index, which is a tilt index held by the tilt index holding unit 46, and the second tilt index, which is a tilt index of the vehicle body 3, becomes greater than or equal to a predetermined second threshold.

[0084] According to the second embodiment configured as described above, if an unexpected tilt occurs in the vehicle body 3, the hydraulic excavator 1 operates in such a way that the tilt fluctuation of the vehicle body 3 is suppressed, thereby ensuring the stability of the vehicle body 3.

[0085] In the second embodiment, the stabilization support device 48 has an operation control unit 48 provided in the control device 40 as a function to intervene in the operation of the operating device 23, and the vehicle body tilt fluctuation determination unit 47 instructs the operation control unit 48 to intervene in the operation of the lower traveling body 5 by the operating device 23 so as to suppress the tilt fluctuation of the vehicle body 3 when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body 3 becomes greater than or equal to the second threshold. As a result, when an unexpected tilt occurs in the vehicle body 3, the lower traveling body 5 operates in such a way as to suppress the tilt fluctuation of the vehicle body 3, thereby ensuring the stability of the vehicle body 3.

[0086] In the second embodiment, the stabilization support device 48 has an operation control unit 48 provided in the control device 40 as a function to intervene in the operation of the operating device 22, and the vehicle body tilt fluctuation determination unit 47 instructs the operation control unit 48 to intervene in the operation of the upper slewing body 7 or the work device 4 by the operating device 22 so as to suppress the tilt fluctuation of the vehicle body 3 when the difference between the first tilt index held by the tilt index holding unit 46 and the second tilt index of the vehicle body 3 becomes greater than or equal to the second threshold. As a result, when an unexpected tilt occurs in the vehicle body 3, the upper slewing body 7 or the work device 4 operates in such a way as to suppress the tilt fluctuation of the vehicle body 3, thereby ensuring the stability of the vehicle body 3.

[0087] In the second embodiment, the hydraulic excavator 1 (working machine) is equipped with a remote control device 600 located outside the vehicle body, and the control device 40 has the function of controlling the lower traveling body 5, the upper rotating body 7, and the working machine 4 in response to the operation of the remote control device 600. This makes it possible to ensure the stability of the vehicle body 3 when the remotely controlled hydraulic excavator 1 travels over terrain that appears to be drivable from the outside but where the stability of the vehicle body 3 may be compromised during travel.

[0088] In the second embodiment, the operation control unit 48 has a function to intervene in the operation of the remote control device 600, and the vehicle body tilt fluctuation determination unit 47 instructs the operation control unit 48 to intervene in the operation of the remote control device 600 so as to suppress the tilt fluctuation of the vehicle body 3 when the difference between the first tilt index held by the tilt index holding unit 46 and the second tilt index of the vehicle body 3 becomes greater than or equal to the second threshold, and the remote control device 600 generates a reaction force in the opposite direction to the direction of operation of the remote control device 600 while the operation control unit 48 is intervening in the operation of the remote control device 600. This makes it possible to inform the operator that the direction of operation of the remote control device 600 is reducing the stability of the vehicle body 3.

[0089] Although embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above and includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to add parts of the configuration of one embodiment to the configuration of another embodiment, and it is also possible to delete parts of the configuration of one embodiment or replace parts of parts of another embodiment. [Explanation of Symbols]

[0090] 1...Hydraulic excavator (working machine), 2...Front working device, 3...Body, 4a...Right travel hydraulic motor, 4b...Left travel hydraulic motor, 5...Lower travel body, 6...Slewing hydraulic motor, 7...Upper slewing body, 8...Boom, 8a...Boom pin, 9...Arm, 9a...Arm pin, 10...Bucket, 10a...Bucket pin, 11...Boom cylinder, 12...Arm cylinder, 13...Bucket cylinder, 14...Boom angle sensor, 15...Arm angle sensor, 16...Bucket link, 17...Bucket angle sensor, 18...Tilt angle sensor, 19...Slewing angle sensor, 21a...Left crawler, 21b...Right crawler, 22a...Right operating lever (operating device), 22b...Left operating lever (operating device), 23a...Right travel lever (operating device), 23b...Left travel lever Lever (operating device), 40...control device, 41...coordinate transformation unit, 42...object detection unit, 43...ground area estimation unit, 44...vehicle proximity area extraction unit, 45...tilt index calculation unit, 46...tilt index holding unit, 47...vehicle tilt change judgment unit, 48...operation control unit (stabilization support device), 51a~51l...solenoid proportional valve, 52a~52f...operation detection device, 53...attitude detection device, 54...surrounding information acquisition device (terrain information acquisition device), 55...notification device (stabilization support device), 71...driver's cab, 100...pilot line, 101...flow control valve, 102...hydraulic pump, 103...engine, 104...pilot pump, 120...swing axis, 200...dump truck, 300...reference coordinate system, 400...grid data, 500...vehicle proximity area, G...ground surface.

Claims

1. Lower running body and An upper slewing body is attached to the lower traveling body so as to be rotatable around a pivot axis, and together with the lower traveling body, constitutes the vehicle body. A work device attached to the upper rotating body, An operating device for operating the lower traveling body, the upper slewing body, and the work device, A posture detection device for detecting the posture of the vehicle body, A terrain information acquisition device that acquires terrain information around the vehicle body, A work machine comprising a control device that controls the operation of the lower traveling body, the upper slewing body, and the work device in accordance with the operation of the aforementioned operating device, The vehicle is equipped with a stabilization support device that performs support actions to ensure the stability of the vehicle body, The control device is A ground area estimation unit that estimates the ground area from the topographic information acquired by the aforementioned topographic information acquisition device, A vehicle proximity region extraction unit extracts a vehicle proximity region from the ground region, which includes the region of the lower vehicle and the region near it. A tilt index calculation unit calculates a tilt index for the region near the traveling body when the maximum difference in the axial direction of the pivot axis of each surface position in the region near the traveling body becomes less than or equal to a predetermined first threshold, While the state in which the maximum difference is less than or equal to the first threshold continues, the slope index holding unit holds the first slope index, which is the slope index calculated by the slope index calculation unit, The system includes a vehicle body tilt fluctuation determination unit that calculates a second tilt index, which is a tilt index of the vehicle body, from the posture of the work machine detected by the posture detection device, and instructs the stabilization support device to perform the support operation when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to a predetermined second threshold. A work machine characterized by the following features.

2. In the work machine described in claim 1, The tilt index calculation unit calculates the sum of the squares of the pitch angle and roll angle of the lower traveling body as the tilt index for the region near the traveling body, The vehicle body tilt fluctuation determination unit calculates the sum of the squares of the pitch angle and roll angle of the lower running body as the vehicle body tilt index. A work machine characterized by the following features.

3. In the work machine described in claim 1, The upper rotating body is equipped with a driver's cab, The stabilization support device has a notification device installed in the driver's cab, The vehicle body tilt fluctuation determination unit instructs the notification device to notify that an unexpected tilt has occurred in the vehicle body when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to the second threshold. A work machine characterized by the following features.

4. In the work machine described in claim 3, The notification device displays the area near the vehicle body extracted by the area near the vehicle body extraction unit. A work machine characterized by the following features.

5. In the work machine described in claim 3, The notification device notifies whether or not the first inclination indicator is being held by the inclination indicator holding unit. A work machine characterized by the following features.

6. In the work machine described in claim 1, The stabilization support device has an operation control unit provided in the control device as a function to intervene in the operation of the operating device, The vehicle body tilt fluctuation determination unit instructs the operation control unit to intervene in the operation of the operating device so as to suppress the tilt fluctuation of the vehicle body when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to the second threshold. A work machine characterized by the following features.

7. In the work machine described in claim 1, The stabilization support device has an operation control unit provided in the control device as a function to intervene in the operation of the operating device, The vehicle body tilt fluctuation determination unit instructs the operation control unit to intervene in the operation of the lower traveling body by the operating device so as to suppress the tilt fluctuation of the vehicle body when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to the second threshold. A work machine characterized by the following features.

8. In the work machine described in claim 1, The stabilization support device has an operation control unit provided in the control device as a function to intervene in the operation of the operating device, The vehicle body tilt fluctuation determination unit instructs the motion control unit to intervene in the operation of the upper rotating body or the work device by the operating device so as to suppress the tilt fluctuation of the vehicle body when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to the second threshold. A work machine characterized by the following features.

9. In the working machine according to any one of claims 6 to 8, The vehicle body is equipped with a remote control device located on the outside of the vehicle body, The control device has the function of controlling the lower traveling body, the upper rotating body, and the work device in response to the operation of the remote control device. A work machine characterized by the following features.

10. In the work machine described in claim 9, The aforementioned operation control unit has a function to intervene in the operation of the remote control device, The vehicle body tilt fluctuation determination unit, when the difference between the first tilt index held by the tilt index holding unit and the second tilt index of the vehicle body becomes greater than or equal to the second threshold, instructs the operation control unit to intervene in the operation of the remote control device so as to suppress the tilt fluctuation of the vehicle body. The remote control device generates a reaction force in the opposite direction to the operating direction of the remote control device when the motion control unit intervenes in the operation of the remote control device. A work machine characterized by the following features.

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