Patent Publication Number: US-2023138107-A1

Title: Control system and method for a work tool on a utility vehicle

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to a utility vehicle. An embodiment of the present disclosure relates to a control system for work tool on utility vehicles. 
     BACKGROUND 
     Utility vehicles, such as motor graders, skid and track loaders, and dozer crawlers often move material along a surface using a work tool. Controlling an amount of pressure on the work tool towards a surface to move a desired amount of material is difficult and requires frequent adjustment. An improved system for controlling the pressure of the work tool on the work surface would help reduce operator fatigue and also reduce unnecessary and/or premature wear on parts of the utility vehicle. 
     SUMMARY 
     Various aspects of examples of the present disclosure are set out in the claims. 
     According to a first aspect of the present disclosure, a system for controlling a work tool for a utility vehicle, the system comprising the work tool, one or more movement mechanisms coupled with the work tool, an imaging apparatus, a non-transitory computer-readable memory storing operation information, and an electronic processor configured to apply the work tool to a surface during movement of a utility vehicle, wherein the work tool is in a first position exerting a first pressure towards the surface, capture, by the first imaging apparatus, a first image of the surface proximate the work tool, evaluate, by the electronic processor, the first image to determine an area of the surface affected by the work tool, and adjust, by the one or more moving mechanisms, the work tool to a second position exerting a second pressure towards the surface, based on the evaluation of the first image. 
     According to a second aspect of the present disclosure, a method of adjusting a pressure applied to a work tool on a surface, the method comprising applying the work tool to the surface during movement of a utility vehicle, wherein the work tool is in a first position exerting a first pressure towards the surface, capturing, by an imaging apparatus, a first image of the surface proximate the work tool, evaluating, by an electronic processor, the first image to determine an area of the surface affected by the work tool, and adjusting, by one or more moving mechanisms, the work tool to a second position exerting a second pressure towards the surface, based on the evaluation of the first image. 
     According to a third aspect of the present disclosure, work vehicle comprising a work tool, one or more movement mechanisms coupled with the work tool, an imaging apparatus, a non-transitory computer-readable memory storing operation information, and an electronic processor configured to apply the work tool to a surface during movement of the utility vehicle, wherein the work tool is in a first position exerting a first pressure towards the surface, capture, by the first imaging apparatus, a first image of the surface proximate the work tool, evaluate, by the electronic processor, the first image to determine an area of the surface affected by the work tool, and adjust, by the one or more movement mechanisms, the work tool to a second position exerting a second pressure towards the surface, based on the evaluation of the first image. 
     The above and other features will become apparent from the following description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description of the drawings refers to the accompanying figures in which: 
         FIG.  1    is a side view of a utility vehicle with a work tool, consistent with embodiments of the present disclosure; 
         FIG.  2    is a side view of the utility vehicle of  FIG.  1    with a first imaging apparatus proximate the work tool, consistent with embodiments of the present disclosure; 
         FIG.  3    is a side view of a utility vehicle with the work tool of a utility vehicle moving material, consistent with embodiments of the present disclosure; 
         FIG.  4    is an image of a display showing information related to the work tool control system, consistent with embodiments of the present disclosure; 
         FIG.  5    is a schematic diagram of the work tool control system, consistent with embodiments of the present disclosure; and 
         FIG.  6    is a flow diagram showing a method of moving material with a work tool, consistent with embodiments of the present disclosure. 
     
    
    
     Like reference numerals are used to indicate like elements throughout the several figures. 
     DETAILED DESCRIPTION 
     At least one example embodiment of the subject matter of this disclosure is understood by referring to  FIGS.  1  through  6    of the drawings. 
     While the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is not restrictive in character, it being understood that illustrative embodiment(s) have been shown and described and that all changes and modifications that come within the spirit of the present disclosure are desired to be protected. Alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the appended claims. 
     Currently, in certain scenarios utility vehicle operators often encounter situations where it is challenging to determine the amount of pressure (i.e., downward force) to be applied to a work tool to achieve a desired amount of material movement. Some operators allow the work tool to “float” where no downward pressure is exerted by the work tool controls (e.g., no pressure by hydraulic cylinders forcing the work tool downward). This is helpful for accommodating variations in the surface being traveled by the work tool. However, this can often increase the wear on the work tool as there is no adjustment of the downward force; it is just gravity pulling the work tool towards the surface. It can be advantageous to allow for better control of the pressure exerted by the work tool on the surface. 
     For example, when plowing snow in winter, a motor grader is often used to clear snow from road surfaces (e.g., gravel, cement, asphalt, etc.). It is beneficial to use the “right” amount of downward pressure exerted by the work tool (e.g., a blade, bucket, etc.) on the surface. Often, the right amount of pressure minimizes wear on the work tool (e.g., wear on a work tool edge, fixed or replaceable) while maximizing the amount of material moved along the surface. 
     In another example, when tilling cropland, shallower tillage results in more crop residue remaining on the surface of the field where deeper tillage results in less crop residue remaining on the field surface. Maintaining an optimal or desired amount of crop residue may be desired but could be challenging based on variable soil conditions in a field, which would require frequent adjustment of tillage settings by an operator. 
     Achieving the desired amount of material movement and/or removal often requires frequent adjustment of the downward pressure of the work tool on the surface (e.g., frequent adjustment of the downward force by various work tool controls, such as hydraulic cylinders). 
     This can be because of changes on the profile of the surface (e.g., bumps, cracks, high/low spots in the surface) or differing properties of the material on the surface that is being moved/removed. For example, when removing snow, fresh, soft snow may require less downward pressure of the work tool on the surface when old, hard packed snow may require more downward pressure of the work tool to achieve the desired result. 
     In some situations, an operator may want to spread material while moving in reverse, depositing some of the material that accumulated on the blade during the forward grading pass. Again, this becomes a manual operation where the operator is required to, after completing a forward grading pass, to lift the blade some amount when reverse is engaged to spread the material while reversing. 
     Advantages for the embodiments described herein include increased productivity and reduction of operator fatigue as the operator doesn&#39;t have to change make as many adjustments of the work took downward pressure while moving material from a surface. 
       FIG.  1    is a side view of a utility vehicle with a work tool, consistent with embodiments of the present disclosure.  FIG.  1    illustrates a utility vehicle in the form of a motor grader  10 . Although a utility vehicle is illustrated and described as the motor grader  10 , the utility vehicle may include, for example, bulldozers, crawlers, feller bunchers, scrapers, excavators, skid and track loaders, tractors, or any other utility vehicle that uses a work tool (e.g., a bucket, a blade, a moldboard, field cultivator, disk cultivator, tillage tool, etc.) to move material such as dirt, sand, gravel, rock, etc. 
     Motor grader  10  includes a main frame  12  and an articulated frame  14  which is pivotable with respect to main frame  12  about articulation joint  17 , which includes vertical pivot  16  ( FIG.  2   ). Such articulation effects steering of the vehicle  10  left and right using a right articulation cylinder  19  and a left articulation cylinder (not shown, but understood to be arranged symmetrically to right cylinder  19  about fore-aft axis A of vehicle  10 ). These left and right articulation cylinders are coupled to and extend between the main frame  12  and articulated frame  14 , as shown, such that extension and contraction of the articulation cylinders reconfigures frames  12 ,  14  from a straight orientation to a turned orientation. Terms such as “left” and “right” are relative to a central fore-aft axis A of the vehicle  10 . 
     Operator cab  13  is mounted atop articulated frame  14 . Operator cab  13  includes operator controls, such as display unit  70  shown in  FIG.  4    and described in detail below, such that a human operator can control the vehicle  10 . 
     Motor grader  10  has two leanable front traction wheels  20  and four non-leanable rear fraction wheels  18 . All of wheels  18 ,  20 , and  21  are operably coupled to engine  212  such that wheels  18 ,  20 ,  21  may be selectively driven to propel frames  12  and  14  respectively along the ground. In particular, main frame  12  supports internal combustion engine  212  (e.g., a diesel engine) of the vehicle  10 , and a tandem  25  on each side of the vehicle  10 , only the right tandem being shown. 
     The articulated frame  14  includes a moldboard  26  (e.g., a blade) mounted thereto. The blade  26  is configured for spreading, leveling, or otherwise moving earthen or other material. In order to facilitate such operations, blade  26  is mounted to frame  14  such that blade  26  is selectively moveable in a number of directions. A draft frame  22  is coupled to articulated frame  14  toward the front via a ball-and-socket joint. A circle frame  28  is coupled to the draft frame  22  to rotate relative thereto by use of a circle drive  38  mounted to the draft frame  22 . A tilt frame  40  holds the blade  26  and is coupled pivotally to the circle frame  28  for pivotal movement of the tilt frame  40  and the blade  26  held thereby relative to the circle frame  28  about a tilt axis by use of a tilt cylinder  30  ( FIG.  2   ). 
     Tilt cylinder  30  is connected to circle frame  28  and tilt frame  40 , such that actuation of tilt cylinder  30  changes the pitch of tilt frame  40  (and thus the moldboard  26 ) relative to circle frame  28 . As best seen in  FIG.  2   , left and right blade-lift cylinders  34  (i.e., hydraulic lift cylinders) are connected to saddle  36  (which in turn is fixed to articulation frame  14 ) and draft frame  22  such that actuation of cylinders  34  raises and lowers the sides of draft frame  22 , and thus the moldboard  26 , relative to articulation frame  14 . A circle side-shift cylinder  35  is connected to the saddle  36  and the draft frame  22 , such that actuation of cylinder  35  effects a side-shift of draft frame  22  and circle frame  28 , and thus the moldboard  26 , relative to the articulation frame  14 . A moldboard side-shift cylinder  32  is connected to the tilt frame  40  and the moldboard  26 , such that actuation of cylinder  32  laterally translates moldboard  26  relative to tilt frame  40  along a longitudinal axis of moldboard  26 . A grader circle motor  38  is coupled to draft frame  22  and operates upon grader circle  24 , such that actuation of motor  38  rotates grader circle  24 . The moldboard  26  is coupled to the circle frame  28  through the tilt frame  40 , and grader circle  24  is fixed to circle frame  28  such that moldboard  26  rotates with circle frame  28  relative to the draft frame  22 . 
       FIG.  2    is a side view of the utility vehicle of  FIG.  1    with a first imaging apparatus proximate the work tool, consistent with embodiments of the present disclosure. The utility vehicle  10  can include a first imaging apparatus  50 . The first imaging apparatus  50  can be coupled with, for example, the main frame  12  or other location (e.g., under the operator cab  13  or on the articulated frame  14 ) at a first position  52 , where the first position  52  is rearward of the blade  26  (i.e., behind the blade  26 ; closer to the rear wheels  18 ). The position of the first imaging apparatus  50  can be any suitable location proximate the work tool (e.g., the first position  52  can be located in other locations beyond main frame  12 ). The first imaging apparatus  50  can be positioned to generally view the back lower portion (i.e., the side closer to the rear wheels  18 ) of the blade  26  and the ground proximate the blade  26  that has just been passed over by the blade. 
     The first imaging apparatus  50  can comprise a camera or other similar imaging device (e.g., radar, lidar, etc.) to capture images of a ground surface proximate the work tool (e.g., blade). Software stored in a non-transitory memory in a controller of a work tool control system (see additional information and discussion below for work tool control system  80 ) can analyze (i.e., evaluate) the images to determine how much the work tool (e.g., blade) needs to be raised (i.e., lifted above the ground) to reduce the amount of material being graded or lowered (i.e., brought closer above the ground) to increase the amount of material being graded. 
     For example, when removing snow from a road surface (e.g., asphalt, gravel, concrete) the work tool is generally scraping the road surface and removing some snow (or ice, etc.), but maybe not all of the snow. As the work vehicle is moving along and removing snow, the first imaging apparatus can capture a first image of the road surface immediately after the work tool has passed over that portion of the road surface (e.g., a first road surface portion or section). Software stored in the non-transitory memory can evaluate the first image by, for example, analyzing the first image for light areas(i.e., lighter portions of the surface) (e.g., snow) and dark areas (i.e., darker portions of the surface) (e.g., the road surface). A road surface can often have a different texture (i.e., a surface texture) from material being removed (e.g., road surface can be rougher texture compared to snow or ice). A road surface can also have different reflection characteristics (i.e., surface reflection) based on the type of material on the surface. A road surface may give a first reflection amount of light and a material (e.g., snow, ice, etc.) may give a second reflection amount of light. 
     Based on these comparisons between portions of the surface in an image, the system can vary the amount of downforce (e.g., apply more or less downforce) to one or both of the left and right blade-lift cylinders (i.e., movement mechanisms) to adjust the amount of material being removed from the surface. The adjustments in downforce can be made frequently (e.g., on the fly while operating) to adjust for variations in the surface being cleared as the utility vehicle moves along a surface. Other types of movement mechanisms are possible in various applications, including worm gears, and rack and pinion arrangements. 
     The analysis of the images can include comparison of a first image to reference image and/or comparison of a first image to a second image. For the comparison of a first image to a reference image, a database of exemplary images can be stored in the non-transitory computer-readable memory and accessed, by the work tool control system, during evaluation of the first image. The first image could also be evaluated with respect to a threshold. For example, the first image may be evaluated to determine if 50% of the surface potentially in contact with the blade has had material moved (e.g., 50% of the road surface still has snow after the blade has passed over that portion of the road surface). An average of the amount of surface in contact with the blade (i.e., the amount of surface graded) could also be calculated as an average over a period of time (e.g., during a shift, over the last 10 minutes, etc.). 
     Based on the analysis of the images, the work tool control system could automatically adjust the blade cylinder pressures to adjust the downward pressure of the blade  26  on the surface  66  depending on the ratio of roadway  66 A to material  66 B in each image captured by the first imaging apparatus  50 . The left and right blade lift cylinder pressures can be monitored by cylinder pressure sensors (not shown) on the left and right blade lift cylinders  34 . 
     The downward pressure of the blade  26  can also be adjusted based on cylinder position sensors without the blade cylinder pressure. The left and right blade lift cylinders  34  can each contain a cylinder position sensor to detect a current position of each cylinder  34 . Based on geometry of the work vehicle  10 , evaluation of the images captured by the first imaging apparatus  50 , signals can be sent to change the position of the left and right blade lift cylinders  34  to increase and/or decrease the amount of material being moved by the blade  26  along the surface  66 . 
     In some embodiments, different portions of the images can be compared. For example, on a motor grader, the blade can be adjusted up and down on each side (e.g., the left side and the right side using the left and right blade lift cylinders  34 ). This could allow for comparison of a left section (i.e., a first section) of a first image with a left section (i.e., a second section) of a second image and comparison of a right section of a first image with a right section of a second image. The image could be divided into any desired number of sections for analysis (e.g., 2 sections, 3 sections, 4 sections, 5 sections, etc.) The downward pressure on the left side of the blade (e.g., by adjusting the left blade cylinder) could be independently adjusted with respect to the downward pressure of the right side of the blade (e.g., by adjusting the right blade cylinder). 
     The side-shift cylinder  35  could be used to expand the area of coverage of the blade as it clears the ground surface as the side-shift cylinder adds some extra range of coverage of the blade to the left or to the right. For example, a position of the work tool could be adjusted based on a width of the surface. The work tool control system could be configured to evaluate images from the first imaging apparatus to see if there are areas of the ground surface outside of the current area of blade coverage and, through the non-transitory computer-readable memory storing instructions, adjust the blade using the side-shift cylinder  35  to the left or the right as needed. 
     A display (e.g., a monitor) can be used to display information related to the work tool control system. See below for additional details. 
       FIG.  3    is side view of a utility vehicle with the work tool of a utility vehicle moving material, consistent with embodiments of the present disclosure. The operator, by way of the operator interface, (or a remote operator or an autonomous operator system) can cause the work vehicle  10  to move forward to spread/move material  66  with the blade  26 . The first imaging apparatus  50  can view the surface  54  proximate the blade  26  after the blade  26  has passed over the surface  54 . 
       FIG.  4    is an image of a display showing information related to the work tool control system, consistent with embodiments of the present disclosure. A display  70  can show, for example, whether the work tool control system  50  is engaged or disengaged (i.e., turned on or turned off), a current operator setting, left and right cylinder pressures, left and right cylinder positions, percentage of downforce being applied by the left and right cylinders. The display can also show a percentage of a surface  66  being graded (i.e., cleared of snow) in real-time. For example, the display could show that the surface is 20% graded, 50% graded, 73% graded. Any percentage from 0-100% is possible. As the display shows the surface  66 , areas of different material coverage could be shown. For example, the surface  66  could include a roadway  66 A (e.g., asphalt, gravel, concrete) with material  66 B (e.g., snow, sand, dirt, etc.) on the roadway. In some instances, the system could be set for 100% downforce, yet the surface may not be 100% of material after the work tool has passed. This is an indication that 100% removal is outside of the system limitations at that location. 
     As the utility vehicle  10  moves along while using the work tool control system, historical material removal data could be stored (e.g., locally in non-transitory computer-readable memory, or on a server in the cloud, to be accessed at a later time but one utility vehicle or multiple utility vehicles). The historical material removal data could include (a) information about the percentage of material moved on a surface and the amount of downward pressure required to achieve that result, (b) information about the percentage of material moved on a surface and the blade position required to achieve that result, (c) information about (a) and/or (b) along with location information tied to specific images captured by the work tool control system (d) information about (a), and/or (b), and/or (c) along with time of day, and (e) environmental conditions. 
     For example, the time of day could affect how much force is required to achieve a certain percentage of material removal from a roadway (e.g., during the daytime, sunlight could make snow softer, allowing for easier removal with less force compared to nighttime, where lack of sunlight would make the snow harder requiring more force for a similar percentage of snow removed from a surface). 
     As the blade  26  (including left blade end  26 A and right blade end  26 B) moves along the surface  66 , different amount of material  66 B will be moved or left behind, depending on the downward pressure of the blade and variations in the shape of the surface  66 . As described herein, the work tool control system can evaluate the images captured by the first imaging apparatus  50  based on the differences of each image as the work vehicle travels along the surface  66 . 
     The display  70  can also include information about the blade  26  position, such as, whether the blade  26  is in a grading position (e.g., generally in contact with the ground (e.g., material) and cutting into the surface) or in a lifted position (e.g., generally not in contact with the ground (e.g., material) and lifted higher than the grading position. The display  70  can include one or more of text characters (i.e., letters and/or numbers), and graphical images related to the information described above. 
       FIG.  5    is a schematic diagram of the work tool control system, consistent with embodiments of the present disclosure. In  FIG.  5   , the various inputs and outputs of the work tool control system  80  are shown. Inputs to the work tool control system  80  can include an operator interface  88 , a first imaging apparatus  50 , a blade position of the work tool  26  (e.g., from left and right blade-lift cylinders  34 ), a pressure being exerted by the blade on the ground surface (via pressure sensors on the left and right blade-lift cylinders  34 ). Additional inputs could include a vehicle location (e.g., GPS data), time of day, ambient temperature and other weather data or environmental conditions. 
     The operator interface  88  could be used to input or set thresholds or ranges with regards to the work tool control system  80 . For example, the operator interface could be used to set a range for the percentage of the surface  66  to be cleared of material  66 A (e.g., a minimum of 50% and a maximum of 80%; or a minimum of 60% and a maximum of 90%, etc.). 
     Outputs from the work tool control system  80  can include a signal to the left and right blade-lift cylinders  34  (e.g., to the hydraulic valves for those cylinders to raise or lower the blade  26 . The signal to the left blade-lift cylinder  34  or the right blade-lift cylinder  34  can include adjusting the corresponding pressure valves to change the amount of pressure applied to cylinders  34 . Another output from the electronic processor  86  can include one or more signals to a display monitor. 
     The blade control system  80  also has a non-transitory computer-readable memory  82  that stores image data  84 . The non-transitory computer-readable memory  82  may comprise electronic memory, nonvolatile random-access memory, an optical storage device, a magnetic storage device, or another device for storing and accessing electronic data on any recordable, rewritable, or readable electronic, optical, or magnetic storage medium. 
     The second image  60  can be compared, by a program stored on the non-transitory computer-readable memory  82 , to the first image  58 . The display  70  can also show one or more of the first image,  58 , the second image  60 , the comparison of the first image  58  and the second image  60  the ground surface proximate the blade  26  (i.e., work tool). 
     An electronic processor  86  is provided and configured to perform an operation by controllably adjusting a position of the work tool  26  relative to the utility vehicle  10  and capturing and processing images from the first imaging apparatus  50 . The electronic processor  86  may be arranged locally as part of the utility vehicle  10  or remotely at a remote processing center (not shown). In various embodiments, the electronic processor  86  may comprise a processor, a microprocessor, a microcontroller, a controller, a central processing unit, a programmable logic array, a programmable logic controller, or other suitable programmable circuitry that is adapted to perform data processing and/or system control operations. The electronic processor  86  executes or otherwise relies upon computer software applications, components, programs, objects, modules, or data structures, etc. Software routines resident in the included memory of the electronic processor  86  or other memory are executed in response to signals received. 
     The computer software applications, in other embodiments, may be located in the cloud. The executed software includes one or more specific applications, components, programs, objects, modules, or sequences of instructions typically referred to as “program code”. The program code includes one or more instructions located in memory and other storage devices which execute the instructions which are resident in memory, which are responsive to other instructions generated by the system, or which are provided by an operator interface  88  operated by the user (e.g., located in the operator cab or at a remote location). The electronic processor  86  is configured to execute the stored program instructions. 
       FIG.  6    is a flow diagram showing a method of moving material with a work tool, consistent with embodiments of the present disclosure. The method  100  can include a step  102  of applying the work tool to the surface during movement of a utility vehicle, wherein the work tool is in a first position exerting a first pressure towards the surface, a step  104  of capturing, by an imaging apparatus, a first image of the surface proximate the work tool, a step  106  of evaluating, by a processor, the first image to determine an area of the surface affected by the work tool, and a step  108  of adjusting, by one or more moving mechanisms, the work tool to a second position exerting a second pressure towards the surface, based on the evaluation of the first image. 
     The second position can include, for example, a position that places the work tool closer to the surface based on a higher pressure exerted towards the surface. In one embodiment, the first position might be a first portion of a pass over a surface being graded with the work vehicle having a blade in a the first grading position and moving forward, then based on image analysis of the surface during grading, the blade could move to a second position above the surface in a second portion of the pass where the blade is closer to the surface due to an increase in downward pressure on the blade, resulting in additional material being moved by the blade. 
     The second position can also include, for example, a position that places the work tool further from the surface based on a lower pressure exerted towards the surface. In this embodiment, the first position might be a first portion of a pass over a surface being graded with the work vehicle having a blade in a the first grading position and moving forward, then based on image analysis of the surface during grading, the blade could move to a second position above the surface in a second portion of the pass where the blade is further from the surface due to a decrease in downward pressure on the blade, resulting in less material being moved by the blade. 
     The method  100  can further comprise the step  110  of displaying on a display (e.g., display  70 ) one or more of the automatic work tool lift system status, the distance from the work tool to the surface, the first position of the work tool, and the second position of the work tool.