TECHNICAL FIELD
The present disclosure relates generally to controlling machines, and more particularly, to systems and methods for determining blade paths for semi-autonomous and autonomous machines using constrained dozing techniques.
BACKGROUND
Machines such as, for example, track-type tractors, dozers, motor graders, wheel loaders, and the like, are used to perform a variety of tasks. For example, these machines may be used to move material and/or alter work surfaces at a worksite. In general, the machines may function in accordance with a work plan for a given worksite to perform operations, including digging, loosening, carrying, and any other manipulation of materials at the worksite. Furthermore, the work plan may often involve repetitive tasks that may be entirely or at least partially automated to minimize operator involvement. Accordingly, the machines may include not only manned machines, but also be autonomous or semi-autonomous vehicles that perform tasks in response to preprogrammed commands or commands delivered remotely or locally.
In such work environments, it is desirable to ensure that the machines perform work operations such that the materials are moved in an efficient and productive manner. In substantially automated work environments, the overall efficiency or productivity relies greatly on the predictability of each machine, or the ability of the machine to accurately execute the task according to the predetermined work plan. In dozing applications for instance, the predictability or the ability of the machine to accurately perform a cut along a given pass target can be affected by variations in the material being worked on, irregularities in the work surface, machine limitations, or any variety of other factors. Moreover, seemingly insignificant deviations in the initial few cuts may become compounded and pronounced after several iterations, which may require more time and effort to correct at the back end.
One way to improve predictability in dozing applications is to reduce the depth of each digging or cutting operation. More particularly, by lessening the load exerted on the machine, the machine behaves in a much more predictable and manageable manner. However, excessive reductions in the cutting depth may adversely affect overall efficiency and productivity. Thus, in at least dozing operations, it is important to define blade paths or blade positions that strike a careful balance between optimum productivity and predictability. Solutions exist, such as in U.S. Pat. No. 6,181,999 (“Yamamoto”), which provide machines that automatically vary blade position based on the load to provide smoother cuts and more predictable passes. Although Yamamoto may provide some benefit, it is still limited in that it functions in a manner that is localized and blind to the overall work plan.
Accordingly, there is a need for systems and methods which provide more intuitive means for planning implement or blade paths that not only improve machine predictability, but also improve overall efficiency and productivity. The present disclosure is directed at addressing one or more of the deficiencies and disadvantages set forth above. However, it should be appreciated that the solution of any particular problem is not a limitation on the scope of this disclosure or of the attached claims except to the extent express noted.
SUMMARY OF THE DISCLOSURE
In one aspect of the present disclosure, a computer-implemented method for determining an implement path for a machine implement at a worksite is provided. The computer-implemented method may include identifying a work surface and a pass target of the worksite, defining a loading profile based on one or more curves constrained to the work surface and the pass target, defining a carry profile based on the loading profile and the pass target, and designating the loading profile and the carry profile as the implement path.
In another aspect of the present disclosure, a control system for determining an implement path for a machine implement at a worksite is provided. The control system may include a memory configured to retrievably store one or more algorithms, and a controller in communication with the memory and, based on the one or more algorithms. The controller may be configured to at least identify a work surface and a pass target of the worksite, define a loading profile based on one or more curves constrained to the work surface and the pass target, and define a carry profile based on the loading profile and the pass target.
In yet another aspect of the present disclosure, a controller for determining an implement path for a machine implement at a worksite is provided. The controller may include a work surface identification module configured to identify a work surface of the worksite, a pass target identification module configured to identify a pass target of the worksite, a loading profile module configured to define a loading profile based on one or more curves constrained to the work surface and the pass target, and a carry profile module configured to define a carry profile based on the loading profile and the pass target.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a pictorial illustration of one exemplary disclosed worksite;
FIG. 2 is a diagrammatic illustration of one exemplary control system that may be used at a worksite;
FIG. 3 is a diagrammatic illustration of one exemplary controller that may be used at a worksite;
FIG. 4 is a diagrammatic illustration of exemplary pass targets and loading profiles that may be generated by a control system of the present disclosure using constrained dozing techniques;
FIG. 5 is a diagrammatic illustration of one exemplary blade path being composed of a loading profile and a carry profile defined by a control system of the present disclosure using constrained dozing techniques;
FIG. 6 is a diagrammatic illustration of one exemplary loading profile being adjusted based on a load extent value as determined by a control system of the present disclosure using constrained dozing techniques;
FIG. 7 is a flowchart depicting one exemplary disclosed method for determining an implement path based on constrained dozing techniques that may be performed by a control system of the present disclosure; and
FIG. 8 is a flowchart depicting one exemplary disclosed method for determining a load extent value based on constrained dozing techniques that may be performed by a control system of the present disclosure.
DETAILED DESCRIPTION
Although the following sets forth a detailed description of numerous different embodiments, it should be understood that the legal scope of protection is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining the scope of protection.
It should also be understood that, unless a term is expressly defined herein, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to herein in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning.
Referring now to FIG. 1, one exemplary worksite 100 is illustrated with one or more machines 102 performing predetermined tasks. The worksite 100 may include, for example, a mine site, a landfill, a quarry, a construction site, or any other type of worksite. The predetermined task may be associated with altering the geography at the worksite 100, such as a dozing operation, a grading operation, a leveling operation, a bulk material removal operation, or any other type of operation that results in geographical modifications within the worksite 100. The machines 102 may be mobile machines configured to perform operations associated with industries related to mining, construction, farming, or any other industry known in the art. The machines 102 depicted in FIG. 1, for example, may embody earth moving machines, such as dozers having blades or other work tools or implements 104 movable by way of one or more actuators 106. The machines 102 may also include manned machines or any type of autonomous or semi-autonomous machines.
The overall operations of the machines 102 and the machine implements 104 within the worksite 100 may be managed by a control system 108 that is at least partially in communication with the machines 102. Moreover, each of the machines 102 may include any one or more of a variety of feedback devices 110 capable of signaling, tracking, monitoring, or otherwise communicating relevant machine information to the control system 108. For example, each machine 102 may include a locating device 112 configured to communicate with one or more satellites 114, which in turn, may communicate to the control system 108 various information pertaining to the position and/or orientation of the machines 102 relative to the worksite 100. Each machine 102 may additionally include one or more implement sensors 116 configured to track and communicate position and/or orientation information of the implements 104 to the control system 108. The implement sensors 116 may also communicate information pertaining to any sensed load on the implement 116, such as the relative weight of any material that is loaded into or carried by the blade of a dozing machine for instance.
The control system 108 may be implemented in any number of different arrangements. For example, the control system 108 may be at least partially implemented at a command center 118 situated locally or remotely relative to the worksite 100 with sufficient means for communicating with the machines 102, for example, via satellites 114, or the like. Additionally or alternatively, the control system 108 may be implemented using one or more computing devices 120 with means for communicating with one or more of the machines 102 or one or more command centers 118 that may be locally and/or remotely situated relative to the worksite 100. In still further alternatives, the control system 108 may be implemented on-board any one or more of the machines 102 that are also provided within the worksite 100. Other suitable modes of implementing the control system 108 are possible and will be understood by those of ordinary skill in the art.
Using any of the foregoing arrangements, the control system 108 may generally be configured to monitor the positions of the machines 102 and/or machine implements 104 relative to the worksite 100 and a predetermined target operation, and provide instructions for controlling the machines 102 and/or machine implements 104 in an efficient manner in executing the target operation. In certain embodiments, the machines 102 may be configured to excavate areas of a worksite 100 according to one or more predefined excavation plans. The excavation plans can include, among other things, determining the location, size, and shape of a plurality of cuts into an intended work surface 122 at the worksite 100 along one or more slots 124. In such embodiments, the control system 108 may be used to plan not only the overall excavation, but also to define an implement or blade path within the slots 124 or any other areas of the work surface 122. For a given work surface 122 and pass target, for instance, the control system 108 may define a blade path, composed of a loading profile and a carry profile, best suited to guide the machines 102 in an efficient, productive and predictable manner. Although described in connection with planning and profiling blade paths, the control system 108 may similarly be employed in conjunction with other types of tasks.
Turning to FIG. 2, one exemplary embodiment of a control system 108 that may be used in conjunction with the worksite 100 and the machines 102 of FIG. 1 is diagrammatically provided. As shown, the control system 108 may generally include, among other things, a controller 126, a memory 128, and a communications device 130. More specifically, the controller 126 may be configured to operate according to one or more algorithms that are retrievably stored within the memory 128. The memory 128 may be provided on-board relative to the controller 126, external to the controller 126, or otherwise in communication therewith. The communications device 130 may be configured to enable the controller 126 to communicate with one or more of the machines 102, and receive information pertaining to the position and/or orientation of the machines 102 and the machine implements 104, for example, via satellites 114, or any other suitable means of communication. Moreover, the controller 126 may be implemented using any one or more of a processor, a microprocessor, a microcontroller, or any other suitable means for executing instructions stored within the memory 128. Additionally, the memory 128 may include non-transitory computer-readable medium or memory, such as a disc drive, flash drive, optical memory, read-only memory (ROM), or the like.
As further shown in FIG. 3, the controller 126 may be configured to determine an implement or blade path, or at least a loading profile thereof, for a machine implement or blade 104 at a worksite 100 according to one or more preprogrammed algorithms which may be generally categorized into, for example, a work surface identification module 132, a pass target identification module 134, a loading profile module 136, a carry profile module 138, and an implement path module 140. With further reference to the exemplary diagram of FIG. 4, the work surface identification module 132 may configure the controller 126 to initially identify the work surface 122 to be worked on, such as in terms of its position relative to the worksite 100, position relative to the machines 102, elevation, slope, curvature, volume, terrain or material composition, or any other relevant information. As shown for example in FIG. 4, a given work surface 122 may generally be defined as the section of terrain along a slot 124 extending between an alignment gap 142 at a first end and a crest 144 at the second end. Information pertaining to the work surface 122 and/or changes thereto may be communicated to the controller 126 via manual entries, programmed entries, periodically updated entries, real-time entries, or any combination thereof. Moreover, the work surface identification module 132 may configure the controller 126 to map the work surface 122 in a two-dimensional format, such as shown in FIG. 4, or alternatively, in a three-dimensional format.
The pass target identification module 134 of FIG. 3 may configure the controller 126 to identify the carry surfaces or pass targets 146 that are ultimately desired. As with the work surface identification module 132, the pass target identification module 134 may identify a pass target 146 in terms of its location or position relative to the worksite 100, position relative to the machines 102, position relative to the work surface 122, elevation, slope, relative volume, terrain or material composition, or any other relevant information. Additionally, a pass target 146 may generally extend the length of the work surface 122 between the alignment gap 142 and the crest 144. The pass targets 146 may be identified using any number of different techniques. As shown for instance in FIG. 4, the pass targets 146 may be identified or defined based on two-dimensional user-defined curves that is positioned, superimposed or otherwise mapped relative to the work surface 122. Moreover, information defining the pass targets 146 may be manually input, programmed or preprogrammed into the controller 126. In other alternative embodiments, the pass targets 146 may be identified based on a two-dimensional cross-section or a lengthwise slice of a three-dimensional model of the pass targets 146. In still further modifications, the controller 126 may be configured to identify the work surface 122 and the pass targets 146 using three-dimensional models, or the like.
As shown for example in FIG. 5, once the work surface 122 and the pass target 146 have been identified, the loading profile module 136 may configure the controller 126 to define a loading profile 148. Specifically, the loading profile 148 may be defined based one or more curves, such as half-Gaussian or otherwise partial Gaussian curves, which are generated according to preprogrammed and/or environmental constraints. In one example, the loading profile 148 may be defined using two adjoined half-Gaussian curves or tail ends of Gaussian curves, each having different standard deviations, heights, or other properties. Furthermore, the Gaussian curves may be constrained such that the resulting loading profile 148 is tangent to the work surface 122 at a start point 150 thereof, or the cut location, and tangent to the pass target 146 at an end point 152 thereof. Additionally or optionally, the loading profile module 136 may configure the controller 126 to ensure that the general slope of the loading profile 148 is not too steep and is less than a predefined threshold. As shown for example in FIG. 6, and as discussed in more detail with respect to FIG. 8 further below, if the general slope of the loading profile 148-1 is determined to be greater than desired for the given worksite 100 and/or the particular machine 102 being used, the loading profile module 136 may adjust the slope based on a slope extent parameter, or the like, and define a new loading profile 148-2 based on the adjusted slope.
The carry profile module 138 of FIG. 3 may correspondingly configure the controller 126 to generally define the carry profile 154 as the portion of the pass target 146 following the loading profile 148, for example, extending from the end point 152 of the loading profile 148 to the crest 144. The carry profile 154 may take the form of a straight line, piece-wise line or curve, a continuous curve, such as a parabola, or the like. Other types of curves, combinations of curves, constraints, parameters and/or techniques may also be used to appropriately define the loading profile 148 and/or the carry profile 154 between the work surface 122 and the pass target 146 and will be apparent to those of ordinary skill in the art. In addition, the implement path module 140 of FIG. 3 may configure the controller 126 to define the implement path 156 as shown for instance in FIG. 5. In a dozing application, for example, the implement path module 140 may designate the entirety of the loading profile 148 together with the carry profile 154 as the blade path 156. Moreover, the blade path 156 may be indicative of the desired depth along which the machine 102 should be operated to dig, cut or carry material within a slot 124, or correspondingly the desired blade height that should be set as the machine 102 travels along a single pass.
Using this blade path 156 as a guide, or lower-bound, for the blade 104, for example, the controller 126 may engage the appropriate actuators 106 associated with the blade 104 of a dozing machine 102 to perform more predictable cuts. Furthermore, in dozing machines 102 with implement sensors 116 or other load-sensing capabilities, the controller 126 may enable features, which when used in conjunction with the blade path 156, can provide smoother slot surfaces. Specifically, the controller 126 may enable sensor-based implement controls to monitor the load of the blade 104 during a cutting operation, and automatically raise the blade 104 once the blade 104 is full or nearly full. When used in relation to a lower-bound that is defined by the blade path 156, for example, a dozing machine 102 may generally cut and load material into the blade 104 for approximately the first two-thirds of the loading profile 148 or until capacity is reached, and automatically raise the loaded blade 104 to a predetermined blade height to be carried along the remaining distance of the loading profile 148 and the carry profile 154. More particularly, the blade height may be predefined such that the blade 104 is at least partially in contact with the terrain as it is carried along the carry surface of the slot 124 in a way that smooths the surface and further promotes predictability for subsequent passes.
Other variations and modifications to the algorithms or methods will be apparent to those of ordinary skill in the art. Exemplary algorithms or methods by which the controller 126 may be operated to determine an implement path 156 for a machine implement 104 as well as to determine an appropriate slope for the loading profile 148 is discussed in more detail below.
INDUSTRIAL APPLICABILITY
In general, the present disclosure sets forth methods, devices and systems for planning implement or blade paths, or at least loading profiles thereof, where there are motivations to promote predictability and improve overall efficiency and productivity. Although applicable to any type of machine, the present disclosure may be particularly applicable to autonomously or semi-autonomously controlled dozing machines where the dozing machines are controlled along particular travel routes within a worksite to excavate materials. Moreover, the present disclosure produces more predictable results by reducing the load that is exerted on the machines and enabling the machines to execute cleaner passes, which further promotes the predictability of successive passes. Furthermore, by enabling smoother passes that are in better agreement with the work plan, the time and resources typically spent on correcting deviations from the work plan are substantially reduced, and overall efficiency is significantly improved.
Turning now to FIG. 7, one exemplary algorithm or computer-implemented method 158 for determining an implement or blade path 156 for a machine implement or blade 104 within a worksite 100 is diagrammatically provided, according to which, for example, the control system 108 and the controller 126 may be configured to operate. As shown, the controller 126 in block 158-1 may initially be configured to identify the work surface 122, such as in terms of position relative to the worksite 100, position relative to the machines 102, elevation, slope, curvature, volume, terrain or material composition, or any other relevant information. For a work surface 122 provided along a slot 124, as shown for instance in FIGS. 1, 4 and 5, the controller 126 may additionally identify the locations of the alignment gap 142 and the crest 144. Moreover, the controller 126 may be configured to receive profile information relating to the work surface 122 and/or changes thereto via manual user input, programmed input, periodically updated input, real-time input, or combinations thereof.
Once information regarding the work surface 122 has been sufficiently identified, mapped or otherwise obtained, the controller 126 may further identify the pass target 146 according to block 158-2 of FIG. 7. Specifically, the controller 126 may be configured to identify the pass target 146 in terms of position relative to the worksite 100, position relative to the machines 102, position relative to the work surface 122, elevation, slope, relative volume, terrain or material composition, or any other relevant information. In general, the pass target 146 may extend the length of the work surface 122 between the alignment gap 142 and the crest 144. While the pass target 146 may be identified using any number of different techniques, the controller 126 may identify or define the pass target 146 based on a two-dimensional representation that is positioned, superimposed or otherwise mapped relative to the work surface 122, as shown for example in FIG. 4. Information regarding the pass target 146 may be manually input, programmed or preprogrammed into the controller 126, or alternatively, identified based on a two-dimensional cross-section or slice of a three-dimensional model of the pass target 146. In other alternatives, the controller 126 may be configured to identify the work surface 122 and the pass target 146 using three-dimensional models.
According to block 158-3 of FIG. 7, the controller 126 may define a loading profile 148. The controller 126 may define the loading profile 148 based one or more curves, such as half-Gaussian or otherwise partial Gaussian curves, which are generated according to preprogrammed and/or environmental constraints. For example, the controller 126 may define the loading profile 148 using two adjoined half-Gaussian curves or tail ends of Gaussian curves, each having different standard deviations, heights, or other properties. The controller 126 may constrain the Gaussian curves such that the loading profile 148 is tangent to the work surface 122 at a start point 150 thereof, or the cut location, and tangent to the pass target 146 at an end point 152 thereof. Additionally or optionally, the controller 126 in block 158-4 may be configured to provide slope correction if the general slope of the loading profile 148 is determined to be too steep for the given worksite 100 and/or machine 102 being used. In general, and as illustrated in FIG. 6, the controller 126 may determine the slope of the loading profile 148-1 determined in block 158-3, compare the slope to a predetermined maximum threshold, and define a new loading profile 148-2 if the slope of the original loading profile 148-1 exceeds the threshold.
Once the loading profile 148 has been determined, the controller 126 in block 158-5 of FIG. 7 may be configured to define a carry profile 154 based on the location of the loading profile 148 and the location of the pass target 146. For example, the controller 126 may define the carry profile 154 as generally extending along the pass target 146 from the end point 152 of the loading profile 148 to the crest 144. The carry profile 154 may take the form of a straight line, piece-wise line or curve, a continuous curve, such as a parabola, or the like. In other alternatives, the controller 126 may be configured to employ any other types of curves, combinations of curves, constraints, parameters and/or techniques to define the loading profile 148 and/or the carry profile 154. Furthermore, the controller 126 in block 158-6 may be configured to define the implement or blade path 156 based on the loading profile 148 and the carry profile 154. More specifically, the controller 126 may designate the length of the loading profile 148 together with the carry profile 154 as the implement or blade path 156 for a given pass. In a dozing application, for example, the blade path 156 may correspond to the lower-bound depth to which the blade 104 of the machine 102 should be constrained while executing a cut and carrying material in a given pass along the slot 124. In other alternatives, the controller 126 may use the blade path 156 as other means of reference for guiding the blade 104 along the slot 124.
Based on the blade path 156, the controller 126 may be able to instruct the machine 102 to dig, cut and carry material along the slot 124 in accordance with block 158-7 of FIG. 7. For example, the controller 126 may engage the machine 102 and/or the actuators 106 for the blade 104 thereof to maintain a blade height that corresponds to the lower-bound identified by the blade path 156. Furthermore, the controller 126 in block 158-8 may enable any sensor-based implement controls that may be available on the machine 102. For example, the controller 126 may enable a load-based blade control feature which monitors the load of the blade 104 during a cutting operation, and automatically raises the blade 104 once the blade 104 is full or nearly full. When used in relation to the lower-bound defined by the blade path 156 for instance, a dozing machine 102 may generally cut and load material into the blade 104 for approximately the first two-thirds of the loading profile 148 or until capacity is reached, and automatically raise the loaded blade 104 to a predetermined blade height to be carried along the remaining distance of the loading profile 148 and the carry profile 154. The predetermined blade height may be defined such that the blade 104 is at least partially in contact with the terrain as it is carried along the carry surface of the slot 124 in a way that smooths the surface and further promotes predictability for subsequent passes.
Turning now to FIG. 8, one exemplary sub-algorithm, algorithm or computer-implemented method 160 for correcting the general slope of a loading profile 148 is provided. As referenced in block 158-4 of FIG. 7, for example, the controller 126 may further determine whether the determined loading profile 148 is too steep for the given worksite 100, the machines 102 being used, or other relevant conditions, and if so, make adjustments to the loading profile 148 accordingly. With reference to the illustration in FIG. 6 for instance, the controller 126 may initially determine or locate the start point 150 and the end point 152 of the given loading profile 148-1 in block 160-1. Based on the start and end points 150, 152 and basic calculations, the controller 126 in block 160-2 may be able to determine the general slope of the loading profile 148-1 relative to the surrounding geographies of worksite 100, work surface 122, slot 124, or the like. In block 160-3, the controller 126 may further compare the slope of the loading profile 148-1 to a predetermined slope threshold. The slope threshold may be preprogrammed value that is specific to the worksite 100 and/or machine 102. Alternatively, the slope threshold may be made variable based on one or more characteristics associated with the worksite 100, machine 102, or the like.
If the general slope of the given loading profile 148-1 is determined to be within acceptable limits, the controller 126 in block 160-4 of FIG. 8 may deem that the loading profile 148-1 is not too steep and instruct the machine 102 to proceed as planned. If, however, the general slope of the given loading profile 148-1 exceeds the predetermined slope threshold, the controller 126 in block 160-5 may be configured to determine a load extent value to correct the slope of the loading profile 148-1. The load extent value may correspond to one or more parameters that can be interpreted by the controller 126 to define a new loading profile 148-2 that meets the slope requirements for the given worksite 100 and/or machine 102. In one example, the load extent value may be determined by calculating the new end point 152-2 which forms a slope with the original start point 150 that satisfies the slope requirements. Additionally, while the start point 150 remains constant, the new end point 152-2 may be constrained to lie along the pass target 146 as shown in FIG. 6. Furthermore, based on the load extent value or at least the new end point 152-2, the controller in block 160-6 may define the new loading profile 148-2 in a manner similar to how the original loading profile 148-1 was created in block 158-3 of FIG. 7 for instance. Specifically, the controller 126 may define the new loading profile 148-2 based one or more curves, such as Gaussian curves, or the like, which are constrained to be tangent to the work surface 122 at the start point 150 thereof, and tangent to the pass target 146 at the new end point 152-2 thereof.
From the foregoing, it will be appreciated that while only certain embodiments have been set forth for the purposes of illustration, alternatives and modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit and scope of this disclosure and the appended claims.
Patent Application
20160201298
