Virtual boundary systems for work machines.

Abstract

The machine (100) includes a frame (110), a plurality of traction devices (116) supporting the frame (110), an engine (118) and an operator cab (120) mounted to the frame (110), an implement system (130) configured to move a work tool (150) to a desired position, a position sensor (230), a tilt and turn system (160) configured to move the work tool (150) to a desired orientation, an orientation sensor (260), an operator interface (220), and a control module (210). The control module (210) is configured to receive a model of the work tool (150), receive boundary inputs (250) defining a virtual boundary (300), receive signals from the position sensor (230) and the orientation sensor (260), receive implement control inputs (240) from the driver interface (220), determine a position and orientation of the work tool (150) based on the signals and the model, determine whether the work tool (150) is approaching the virtual boundary (300) based on the position and orientation, the boundary inputs (250), and the implement control inputs (240), and automatically prevent the work tool (150) from crossing the virtual boundary (300).

Description

[Technical Field]

[0001] The present disclosure relates generally to work machines, and more particularly to methods and systems for providing a virtual boundary for a work machine having a work tool. [Background technology]

[0002] Excavators and other similar work machines must frequently operate in close proximity to obstacles and hazards, such as walls, power lines, roads, and buried utilities. These machines can include any number of construction, mining, agricultural, and industrial work machines, including, but not limited to, excavators, bulldozers, tractors, and the like, which often have work tools with wide ranges of motion that can come into contact with these hazards. The need to operate within restricted areas increases the risk of damage to the machine or its surroundings. Additionally, the need to constantly restrict the machine's movement places a strain on the operator.

[0003] The prior art has failed to adequately address this problem. While systems such as those disclosed by U.S. Patent No. 9,725,874 to Meguriya et al. provide some form of automatic motion constraint, these systems focus on automating the creation of reference surfaces at specific grades. Furthermore, they do not consider the three-dimensional orientation of the work tool or allow for complex three-dimensional boundaries. Additionally, previous boundary systems require assuming a spherical shape of the work tool, which limits accuracy.

[0004] Therefore, there is a need for a work machine with an improved boundary system. Summary of the Invention

[0005] According to one aspect of the present disclosure, a machine having a work tool is disclosed. The machine includes a frame, a plurality of traction devices supporting the frame, an engine mounted to the frame, an operator's cab mounted to the frame, an implement system configured to move the work tool to a desired position in three dimensions and having a plurality of position sensors, a tilt and turn system to move the work tool to a desired orientation in three dimensions and having a plurality of orientation sensors, a driver interface configured to receive boundary inputs and implement control inputs, and a control module. The control module is configured to receive a three-dimensional model of the work tool, receive boundary inputs from the driver interface defining a virtual boundary, receive signals from the plurality of position sensors and the plurality of orientation sensors, receive implement control inputs from the driver interface, determine a position and orientation of the work tool based on the signals and the model, determine whether the work tool is approaching the virtual boundary based on the position and orientation of the work tool, the boundary inputs, and the implement control inputs, and automatically prevent the work tool from crossing the virtual boundary.

[0006] According to another aspect of the present disclosure, a virtual boundary system for a machine having a work tool is disclosed. The system includes an implement system configured to move the work tool to a desired position in three dimensions and having a plurality of position sensors, a tilt and rotate system for moving the work tool to a desired orientation in three dimensions and having a plurality of orientation sensors, a driver interface configured to receive boundary inputs and implement control inputs, and a control module. The control module is configured to receive a three-dimensional model of the work tool, receive boundary inputs from the driver interface defining a virtual boundary, receive signals from the plurality of position sensors and the plurality of orientation sensors, receive implement control inputs from the driver interface, determine a position and orientation of the work tool based on the signals and the model, determine whether the work tool is approaching the virtual boundary based on the position and orientation of the work tool, the boundary inputs, and the implement control inputs, and automatically prevent the work tool from crossing the virtual boundary.

[0007] According to yet another aspect of the present disclosure, a method for controlling a work tool is disclosed, the method including receiving a three-dimensional model of the work tool, receiving boundary inputs defining a virtual boundary, receiving signals from a plurality of position sensors and a plurality of orientation sensors, receiving an implement control input from an operator interface, determining a position and orientation of the work tool based on the signals and the model, determining whether the work tool is approaching the virtual boundary based on the position and orientation of the work tool, the boundary inputs, and the implement control inputs, and automatically preventing the work tool from crossing the virtual boundary.

[0008] These and other aspects and features of the present disclosure will be more readily understood after reading the following detailed description in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a work machine according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a block diagram of a virtual boundary system according to one aspect of the present disclosure. [Figure 3] FIG. 3 is a close-up of a work tool and virtual boundary of a shovel according to one embodiment of the present disclosure. [Figure 4] FIG. 4 is a side view of a shovel and a virtual boundary according to one embodiment of the present disclosure. [Figure 5] FIG. 5 is a side view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 6] FIG. 6 is a top view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 7] FIG. 7 is a perspective view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 8] FIG. 8 is a top view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 9] FIG. 9 is a side view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 10] FIG. 10 is a perspective view of a work machine and a virtual boundary according to one embodiment of the present disclosure. [Figure 11] FIG. 11 is a flow diagram of a method for restricting movement of a work tool according to one aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] Referring now to the drawings, and particularly to FIG. 1 , an exemplary work machine according to the present disclosure is designated by the reference numeral 100. Specifically, FIG. 1 shows an excavator, however, work machine 100 may also be other types of construction or mining machinery, such as a backhoe, front shovel, wheel loader, or another similar machine and material handling device. As shown in FIG. 1 , machine 100 includes a frame 110 having a lower section 112 and an upper section 114. Lower section 112 is supported by ground engaging devices 116, which may be tracks, wheels, or the like. An engine 118 and an operator's cab 120 are mounted on upper section 114.

[0011] Additionally, machine 100 has an implement system 130 configured to move work tool 150 to perform operations on machine 100. Implement system 130 may include a boom 132 and a stick 134. Boom 132 has a first end 133 connected to upper section 114 of frame 110 and pivotable vertically relative to frame 100. A second end 135 of boom 132 is connected to stick 134 and is also pivotable vertically. Boom 132 and stick 134 may be positioned by hydraulic cylinders 136, or any other mechanism capable of moving parts, as needed. Implement system 130 may also include a swivel system 140 (not shown) that enables rotational movement of implement system 130 about frame 110. Swivel system 140 is configured to rotate upper section 114 of frame 110 relative to lower section 112. This allows the lower section 112 of the frame 110 to maintain a stable base while the upper section 114 rotates the implement system 130 to the required angle. The swivel system 140 may also be operated by a hydraulic device 136.

[0012] The implement system 130 further includes a plurality of position sensors 230. The position sensors 230 may include displacement sensors on hydraulic cylinders, angle sensors at pivot joints, inclinometers, gyro sensors, tilt sensors, earth reference sensors, or any other sensors that may contribute to determining the position of the work tool. The position sensors 230 provide signals to the control module 210 (see FIG. 2).

[0013] The work tool 150 is attached to the end of the stick 134 farthest from the boom 132 via a tilt and rotate system 160 configured to allow the work tool 150 to tilt and rotate in multiple dimensions. The work tool 150 shown in the figures is a bucket, but may alternatively be any device used to perform a particular task, including, but not limited to, a fork arrangement, a blade, a shovel, or any other task-performing device. The tilt and rotate system 160 further includes multiple orientation sensors 260, including at least a rotation sensor 252 and a tilt sensor 254. The orientation sensors 260 may include displacement sensors on hydraulic cylinders, angle sensors at pivot joints, inclinometers, gyro sensors, tilt sensors, or any other sensors that may contribute to determining the orientation of the work tool 150.

[0014] Movement of the implement system is controlled by the control module 210 based on implement control input 240 from the operator in the operator cab 120 through the operator interface 220. The implement control input 240 may be provided by a joystick, buttons, a touch interface, or any other device effective for the purpose.

[0015] The controls and orientation sensor 260 for the tilt and rotate system 160 are integrated directly into the same control module 210 as the implement system 130. In this manner, the orientation of the work tool 150 is controlled by the tilt and rotate system 160 through the implement control input 240 to the operator interface 220 and the control module 210. In some other systems, similar tilt and rotate systems include a separate control module that interacts with the primary machine control module, which is a pass-through device for lever commands. If such a separate control module fails, the machine may become inoperable because it passes through the lever commands without reading them. The integration of the tilt and rotate system 160 within the control module 210 allows direct access to sensor information, preventing delays and enabling more effective diagnosis of errors. Specifically, the integration allows for partial shutdown and diagnosis in the event of a partial, rather than complete, machine failure.

[0016] Together, the implement system 130 and tilt and rotate system 160 allow the work tool 150 to be moved to any position and orientation within a three-dimensional range. However, in many applications, there may be portions of that range that should be avoided to prevent damage to obstacles and hazards in the area or for other reasons. Using the virtual boundary system 200, it is possible to automatically restrict the work tool from moving beyond a desired range with at least one virtual boundary 300. As shown in FIG. 2 , the virtual boundary system 200 includes a position sensor 230 of the implement system 130, an orientation sensor 260 of the tilt and rotate system 160, an operator interface 220, and a control module 210.

[0017] Before starting work, the control module 210 receives a three-dimensional model of the work tool 150. The model includes the dimensions of the work tool 150, including details of its external shape. This allows the system to determine whether the work tool 150 is approaching a virtual boundary 300 based on its actual shape, rather than an approximation, as shown in FIG. 3. If the work tool 150 is a bucket or similar tool with an interior space, the model does not need to include the interior shape. In the bucket example, the system may determine whether a corner of a tooth or the rear of the bucket is near the virtual boundary.

[0018] The control module 210 also receives boundary input 250 that defines a virtual boundary 300. The boundary input 250 may be provided via the operator interface 220. The virtual boundary 300 is configured as a plane that can be oriented in several ways. The horizontal plane may be below the machine 100 as a floor, as shown in FIG. 4, or above the machine 100 as a ceiling (FIG. 5). The vertical plane may be parallel to the boom and stick of the machine 100 to prevent lateral movement (FIG. 6), in front of the machine 100 (FIG. 7), or at any angle between the side and front walls, one such embodiment of which is shown in FIG. 8. The vertical plane may also be used to protect the operator cab 120, as shown in FIG. 9. Finally, the virtual boundary 300 may be neither vertical nor horizontal, but instead a plane that forms a slope, as shown in FIG. 10. Other boundaries 300 may be devised, which may include curved or other complex shapes.

[0019] The virtual boundary 300 may be programmed into the control module 210 as a boundary input either manually using measurements including offset, slope, and cross slope, or by placing the bucket at a series of points and setting a plane relative to those locations. Of course, other methods of providing boundary parameters may be used. The boundary 300 may be indicated relative to the machine 100 or as a global reference. A global reference may use the earth's position and orientation from a GNSS, or less information (e.g., only elevation or heading, such as from a compass). Multiple boundaries may be entered to completely define the work area.

[0020] As machine 100 operates, control module 210 receives signals from a plurality of position sensors 230 and a plurality of orientation sensors 260. These signals enable control module 210 to determine the precise three-dimensional position and orientation of work tool 150. In combination with a model of work tool 150, the positions of all edges and tips of work tool 150 can be precisely understood.

[0021] The control module 210 also receives implement control inputs 240 from the driver interface 220. These inputs represent actions that the driver instructs the implement system 130 and tilt and turn system 160 to take.

[0022] The control module then determines whether the work tool 150 is approaching the virtual boundary 300 based on the determined position and orientation of the work tool 150 and the boundary input 250 and the implement control input 240 .

[0023] Finally, the work tool 150 is automatically prevented from crossing the virtual boundary 300. This is accomplished by stopping movement of the implement system 130 or tilt and rotate system 160, regardless of any further implement control input 240 in that direction by the operator. Implement control inputs 240 directing movement away from the virtual boundary 300 are unaffected.

[0024] Virtual boundary system 200 may further include an alert when work tool 150 comes within a threshold distance of virtual boundary 300. The alert may be a visual or audible indicator in operator cab 120. [Industrial Applicability]

[0025] Work machines, such as excavators and other earthmoving and construction equipment, must frequently operate in close proximity to obstacles and hazards, such as walls, power lines, roads, and buried utilities. The need to work within confined areas places a strain on the operator, who must constantly monitor the machine's movements. Furthermore, these conditions pose an increased risk of damage to the machine, its surroundings, and even bystanders. The virtual boundary system 200 may be useful in any application where a work tool must operate within a confined space. This may include construction, mining, agriculture, and similar industries.

[0026] The virtual boundary system 200 uses the following method 400, shown in Figure 11. Before work begins, the control module 210 receives a three-dimensional model of the work tool 150 (block 410). The model includes the work tool's dimensions, including geometric details. This allows the system to determine whether the work tool is approaching a barrier based on its actual shape and three-dimensional orientation, rather than an approximation.

[0027] Control module 210 also receives boundary input from the operator interface (block 420), which defines virtual boundary 300. Virtual boundary 300 may be defined by offsets, grades, and cross slopes, which may be entered manually as measurements, or by placing a work tool at multiple points across a plane. Measurements may be defined relative to machine 100 or as an earth reference. Virtual boundary 300 may have a planar shape.

[0028] As machine 100 operates, control module 210 receives signals from the plurality of position sensors 230 and the plurality of orientation sensors 260 (block 430). Control module 210 also receives implement control inputs from operator interface 220, as shown in block (440). These inputs represent actions that the operator instructs implement system 130 and tilt and turn system 160 to perform.

[0029] Based on the signals, the control module 210 determines the three-dimensional position and orientation of the work tool 150 (block 450). Next, as shown in block 460, the control module determines whether the work tool 150 is approaching the virtual boundary 300 based on the position and orientation of the work tool 150 (determined in block 450) and the boundary input and the implement control input. If the work tool is approaching the virtual boundary (block 470), the work tool 150 is automatically prevented from crossing the virtual boundary 300, as shown in block 480. This is accomplished by stopping movement of the implement system 130 or tilt and rotate system 160, regardless of any further operator input in that direction. On the other hand, if the work tool is not approaching the virtual boundary, normal operation of the machine 100 continues (block 490). Operator inputs directing movement away from the virtual boundary 300 are unaffected.

[0030] While the foregoing text has provided detailed descriptions of many different embodiments, it should be understood that the legal scope of protection is defined by the language of the claims at the end of this patent. The detailed description should be construed as merely exemplary and will not describe every possible embodiment, as doing so would be impractical, if not impossible. Numerous alternative embodiments can be implemented, using either current technology or technology developed after the filing date of this patent, and still fall within the scope of the claims that define the scope of protection.

Claims

1. A machine (100) comprising: A frame (110); a plurality of traction devices (116) supporting the frame (110); an engine (118) mounted on the frame (110); a driver's cab (120) attached to the frame (110); an implement system (130) connected to the frame (110), the implement system (130) being configured to move a work tool (150) to a desired position in three dimensions and having a plurality of position sensors (230); a tilt and rotate system (160) configured to move the work tool (150) to a desired orientation in three dimensions, the tilt and rotate system having a plurality of orientation sensors (260); a driver interface (220) configured to receive boundary inputs (250) and implement control inputs (240); A control module (210) comprising: receiving a three-dimensional model of the work tool (150); receiving the boundary input (250) from the driver interface (220) defining a virtual boundary (300); receiving signals from the plurality of position sensors (230) and the plurality of orientation sensors (260); receiving the implement control input (240) from the driver interface (220); determining a position and orientation of the work tool (150) based on the signals and the three-dimensional model; determining whether the work tool (150) is approaching the virtual boundary (300) based on the position and orientation of the work tool (150), the boundary input (250), and the tool control input (240); a control module (210) configured to automatically prevent the work tool (150) from crossing the virtual boundary (300).

2. The machine (100) of claim 1, wherein controls and sensors for the tilt rotation system (160) are integrated directly into the control module (210).

3. The machine (100) of claim 1, wherein a plurality of virtual boundaries (300) are defined.

4. The machine (100) of claim 1, wherein the virtual boundary (300) is planar.

5. The machine (100) of claim 1, wherein the virtual boundary (300) is defined by an offset, a slope, and a cross slope.

6. The machine (100) of claim 1, wherein the virtual boundary is defined relative to the machine.

7. The machine (100) of claim 1, wherein the virtual boundary (300) is defined by an earth reference.

8. A virtual boundary system (200) for a machine (100) having a work tool (150), comprising: an implement system (130) configured to move the work tool (150) to a desired position in three dimensions and having a plurality of position sensors (230); a tilt and rotate system (160) configured to move the work tool (150) to a desired orientation in three dimensions, the tilt and rotate system having a plurality of orientation sensors (260); a driver interface (220) configured to receive boundary inputs (250) and implement control inputs (240); A control module (210) comprising: receiving a three-dimensional model of the work tool (150); receiving the boundary input (250) from the driver interface (220) defining a virtual boundary (300); receiving signals from the plurality of position sensors (230) and the plurality of orientation sensors (260); receiving the implement control input (240) from the driver interface (220); determining a position and orientation of the work tool (150) based on the signals and the three-dimensional model; determining whether the work tool (150) is approaching the virtual boundary (300) based on the position and orientation of the work tool (150), the boundary input (250), and the tool control input (240); a control module (210) configured to automatically prevent the work tool (150) from crossing the virtual boundary (300).

9. The system (200) of claim 8, wherein controls and sensors for the tilt and rotate system (160) are integrated directly into the control module (210).

10. The system (200) of claim 8, wherein a plurality of virtual boundaries (300) are defined.

11. The system (200) of claim 8, wherein the virtual boundary (300) is planar.

12. The system (200) of claim 8, wherein the virtual boundary (300) is defined by an offset, a slope, and a cross slope.

13. The system (200) of claim 8, wherein the virtual boundary is defined relative to the machine.

14. The system (200) of claim 8, wherein the virtual boundary (300) is defined by an earth reference.

15. The system (200) of claim 8, wherein the plurality of orientation sensors (260) includes a tilt sensor and a rotation sensor.

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