Patent Publication Number: US-11028557-B2

Title: Attachment grade control for work vehicle

Description:
FIELD OF THE DISCLOSURE 
     The present disclosure generally relates to work vehicles, such as skid steers, compact track loaders, and other agricultural and construction loaders, and more particularly to a grade control for an attachment of a work vehicle. 
     BACKGROUND OF THE DISCLOSURE 
     In order to control grade for a variety of attachments, manual operator controls are commonly used. 
     SUMMARY OF THE DISCLOSURE 
     In one embodiment, a work vehicle is disclosed. The work vehicle comprises a frame. At least one ground engaging device is coupled to the frame and configured to support the frame above a surface. A positioning receiver is coupled to the frame and configured to receive a geospatial positioning signal. A boom assembly is coupled to the frame. At least one boom cylinder is coupled to the frame and the boom assembly and configured to move the boom assembly. A boom position sensor is coupled to at least one of the frame, the boom assembly, and the boom cylinder and configured to transmit a boom position signal indicative of a position of the boom assembly. An attachment coupler is coupled to a distal portion of the boom assembly. At least one tilt cylinder is coupled to the boom assembly and the attachment coupler and configured to move the attachment coupler. An attachment position sensor is coupled to at least one of the boom assembly, the attachment coupler, and the tilt cylinder and configured to transmit an attachment position signal indicative of a position of the attachment coupler. An attachment is coupled to the attachment coupler. An identification device is coupled to the attachment and configured to transmit an attachment identification signal after an activation event. A display is communicatively coupled to the identification device and configured to display the attachment identification signal. The display comprises an operator input device configured to receive an operator input indicative of an attachment confirmation and a grade command. The work vehicle further comprises a work vehicle control comprising a standard configuration and an updated configuration. A controller is configured to receive the geospatial positioning signal, the boom position signal, the attachment position signal, and the operator input. The controller is configured to reference a memory device and change the work vehicle control between the standard configuration and the updated configuration. The controller is configured to control an elevation of the attachment according to the grade command. 
     In another embodiment, a work vehicle is disclosed. The work vehicle comprises a frame. At least one ground engaging device is coupled to the frame and configured to support the frame above a surface. A positioning receiver is coupled to the frame and configured to receive a geospatial positioning signal. A boom assembly is coupled to the frame. At least one boom cylinder is coupled to the frame and the boom assembly and configured to move the boom assembly. A boom position sensor is coupled to at least one of the frame, the boom assembly, and the boom cylinder and configured to transmit a boom position signal indicative of a position of the boom assembly. An attachment coupler is coupled to a distal portion of the boom assembly. At least one tilt cylinder is coupled to the boom assembly and the attachment coupler and configured to move the attachment coupler. An attachment position sensor is coupled to at least one of the boom assembly, the attachment coupler, and the tilt cylinder and configured to transmit an attachment position signal indicative of a position of the attachment coupler. An attachment is coupled to the attachment coupler. At least one of an IMU and a slope sensor is coupled to the attachment and configured to transmit a slope signal indicative of a slope of the attachment relative to the frame. The controller is configured to control the elevation and a slope of the attachment according to the grade command. An identification device is coupled to the attachment and configured to transmit an attachment identification signal after an activation event. A display is communicatively coupled to the identification device and configured to display the attachment identification signal. The display comprises an operator input device configured to receive an operator input indicative of an attachment confirmation and a grade command. The work vehicle further comprises a work vehicle control comprising a standard configuration and an updated configuration. A controller is configured to receive the geospatial positioning signal, the boom position signal, the attachment position signal, the slope signal, the attachment identification signal, and the operator input. The controller is configured to change the work vehicle control between the standard configuration and the updated configuration. The controller is configured to control an elevation and a slope of the attachment according to the grade command. 
     In yet another embodiment, a work vehicle is disclosed. The work vehicle comprises a frame. At least one ground engaging device is coupled to the frame and configured to support the frame above a surface. A positioning receiver is coupled to the frame and configured to receive a geospatial positioning signal. A boom assembly is coupled to the frame. At least one boom cylinder is coupled to the frame and the boom assembly and configured to move the boom assembly. A boom position sensor is coupled to at least one of the frame, the boom assembly, and the boom cylinder and configured to transmit a boom position signal indicative of a position of the boom assembly. An attachment coupler is coupled to a distal portion of the boom assembly. At least one tilt cylinder is coupled to the boom assembly and the attachment coupler and configured to move the attachment coupler. An attachment position sensor is coupled to at least one of the boom assembly, the attachment coupler, and the tilt cylinder and configured to transmit an attachment position signal indicative of a position of the attachment coupler. A dozer blade is coupled to the attachment coupler. At least one of an IMU and a slope sensor is coupled to the dozer blade and configured to transmit a slope signal indicative of a slope of the dozer blade relative to the frame. The controller is configured to control the elevation and a slope of the dozer blade according to the grade command. An identification device is coupled to the dozer blade and configured to transmit an attachment identification signal after an activation event. A boom lock is coupled to at least one of the frame and the boom assembly. The boom lock is configured to move from an unlocked position where the boom assembly is moveable to a locked position where the boom assembly is locked to the frame in a lowered position when the attachment identification signal indicates the dozer blade. A display is communicatively coupled to the identification device and configured to display the attachment identification signal. The display comprises an operator input device configured to receive an operator input indicative of an attachment confirmation and a grade command. The work vehicle further comprises a work vehicle control comprising a standard configuration and an updated configuration. A controller is configured to receive the geospatial positioning signal, the boom position signal, the attachment position signal, the slope signal, the attachment identification signal, and the operator input. The controller is configured to change the work vehicle control between the standard configuration and the updated configuration. The controller is configured to control an elevation and a slope of the dozer blade according to the grade command. 
     Other features and aspects will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a work vehicle with a boom lock. 
         FIG. 2A  is a schematic of a work vehicle control of the work vehicle of  FIG. 1  in a standard configuration. 
         FIG. 2B  is a schematic of a work vehicle control of the work vehicle of  FIG. 1  in an updated configuration. 
         FIG. 3  is a perspective view of the work vehicle of  FIG. 1  with a boom assembly in a lowered position and a raised position. 
         FIG. 4  is a side view of a work vehicle with a dozer blade. 
         FIG. 5A  is a bottom view of the work vehicle of  FIG. 1 , showing the boom lock according to one embodiment. 
         FIG. 5B  is a bottom view of the work vehicle of  FIG. 1 , showing the boom lock according to another embodiment. 
         FIG. 5C  is a bottom view of the work vehicle of  FIG. 1 , showing the boom lock according to yet another embodiment. 
         FIG. 6A  is a perspective view of a work vehicle with forks. 
         FIG. 6B  is a perspective view of a work vehicle with a trencher. 
         FIG. 7  is a perspective view of the work vehicle of  FIG. 1 , showing the boom assembly in a dump position. 
         FIG. 8  is a schematic of the work vehicle with the boom lock. 
         FIG. 9A  is a schematic of an illustrative method for locking a boom assembly of a work vehicle to a frame of the work vehicle. 
         FIG. 9B  is a schematic of an illustrative method for maintaining a cutting edge on a cutting plane in both an operating position and a dump position of a work vehicle. 
     
    
    
     Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Further embodiments of the invention may include any combination of features from one or more dependent claims, and such features may be incorporated, collectively or separately, into any independent claim. 
     As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “at least one of” or “one or more of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C). 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a work vehicle  10  having a frame  15 . The work vehicle  10  is illustrated as a compact track loader  20 . Other types of work vehicles  10  are contemplated by this disclosure including skid steers and other types of agricultural, construction, or forestry loaders, for example. At least one ground engaging device  25  is coupled to the frame  15  and configured to support the frame  15  above a surface  30  and to move the work vehicle  10  along the surface  30 . The illustrated ground engaging device  25  is a pair of tracks  35 . Alternatively, the ground engaging device  25  may be wheels (not shown). 
     An operator&#39;s station  40  having a door  45  is coupled to the frame  15 . An operator interface  50  may be positioned in the operator&#39;s station  40  or remote from the work vehicle  10 . The operator interface  50  may be a display  55  that may comprise an operator input device  60  configured to set or change a work vehicle setting or parameter  65  ( FIG. 8 ) such as a grade command  70  ( FIG. 8 ). For example, the display  55  may be a touch screen  75 . The operator input device  60  may be separate from the display  55 . For example, the operator input device  60  may be a keypad  80  or a sealed switch module (“SSM”)  85 . 
     A work vehicle control  90  may also be positioned in the operator&#39;s station  40  or remote from the work vehicle  10 . With reference to  FIGS. 2A and 2B , the work vehicle control  90  may include a first joystick  95 , a second joystick  100 , and any combination of a plurality of switches  102  (e.g., rotary wheel) and a plurality of buttons  103  (e.g., pushbutton) or other control devices (e.g., dials, knobs). For example, the first joystick  95  may have the plurality of buttons  103  and the second joystick  100  having a switch  102  and the plurality of buttons  103 . Other switch  102  and button  103  configurations are contemplated by this disclosure. The functions of the work vehicle control  90  may be re-assignable from a standard configuration  105  to an updated configuration  110 . For example, from a standard configuration  105  like a compact track loader mode  115  to an updated configuration  110  like a dozer mode  120  or other mode (e.g., fork mode, trencher mode). 
     In the standard configuration  105 , the updated configuration  110 , the compact track loader mode  115 , and the dozer mode  120 , the first joystick  95  may have the same operation and functions: push the first joystick  95  forward for forward  125  movement of the work vehicle  10 , push the first joystick  95  rearward for reverse  130  movement of the work vehicle  10 , push the first joystick  95  right to turn right  135 , and push the first joystick  95  left to turn left  140 . 
     In the standard configuration  105  and the compact track loader mode  115 , the second joystick  100  may have the same operation and functions: push the second joystick  100  forward for boom down  145 , push the second joystick  100  rearward for boom up  150 , push the second joystick  100  right for bucket down  155 , and push the second joystick  100  left for bucket up  160 . 
     In the updated configuration  110  and the dozer mode  120 , the second joystick  100  may have the same operation and functions: push the second joystick  100  forward for blade down  165 , push the second joystick  100  rearward for blade up  170 , push the second joystick  100  right for blade tilt right  175 , push the second joystick  100  left for blade tilt left  180 , push the switch  102  forward for blade angle right  185 , and push the switch  102  rearward for blade angle left  190 . 
     Referring to  FIG. 1 , a boom assembly  195  is coupled to the frame  15 . The boom assembly  195  comprises a pair of upper links  200  pivotally coupled to the frame  15 . A pair of lower links  205  are pivotally coupled to the frame  15 . A pair of boom cylinders  210  are pivotally coupled to the frame  15  with one per side of the work vehicle  10 . The boom cylinders  210  may be hydraulic actuators  215  or electronic actuators  220 . A pair of boom arms  225  are pivotally coupled to the upper links  200  and the lower links  205  and positioned one per side of the work vehicle  10 . The pair of boom arms  225  are pivotally coupled to the boom cylinders  210 . With reference to  FIGS. 1 and 3 , the boom cylinders  210  are configured to move the boom assembly  195  from a lowered position  230  to a raised position  235 . Other boom assembly  195  configurations are contemplated by this disclosure. 
     Referring to  FIG. 1 , a boom position sensor  240  is coupled to at least one of the frame  15 , the boom assembly  195 , and the boom cylinder  210 . The boom position sensor  240  is configured to transmit a boom position signal  245  ( FIG. 8 ) indicative of a position of the boom assembly  195 . The boom position sensor  240  may be a rotary sensor, cylinder position sensor, or other type of sensor. 
     With reference to  FIG. 4 , an attachment coupler  250  is coupled to a distal portion  255  of the boom assembly  195 . A pair of tilt cylinders  260  are coupled to the boom assembly  195  and the attachment coupler  250  with one per side of the work vehicle  10 . The tilt cylinders  260  may be hydraulic actuators  265  or electronic actuators  270 . The tilt cylinders  260  are configured to move or tilt the attachment coupler  250 . 
     Referring to  FIGS. 1 and 4 , a hydraulic system  275  is fluidly coupled to the boom cylinders  210  and the tilt cylinders  260 . The hydraulic system  275  comprises a hydraulic pump  280  and a hydraulic valve  285  (e.g., electrohydraulic valve) to control hydraulic fluid flow to the boom cylinders  210  and tilt cylinders  260  after receiving input from at least one of the operator interface  50  and the work vehicle control  90 . With reference to  FIGS. 2A, 2B, and 4 , in the updated configuration  110  the functions of the first joystick  95 , the second joystick  100 , the switches  102 , and the buttons  103  may be changed to control different aspects of the hydraulic system  275 . For example, the second joystick  100  that controlled the boom cylinders  210  in the forward boom down  145  and reverse boom up  150  directions in the compact track loader mode  115  may now be changed to control the tilt cylinders  260  in the forward blade down  165  and reverse blade up  170  directions in the dozer mode  120 . This disclosure contemplates other aspects of the hydraulic system  275  may be controlled by other changes to the first joystick  95 , the second joystick  100 , switches  102 , and buttons  103 . 
     With reference to  FIGS. 5A, 5B, and 5C , a boom lock  290  may be coupled to at least one of the frame  15  and the boom assembly  195 . The boom lock  290  is configured to move from an unlocked position  295  where the boom assembly  195  is moveable to a locked position  300  where the boom assembly  195  is locked to the frame  15  in the lowered position  230  ( FIG. 3 ). The boom lock  290  may comprise a receiving device  305  coupled to at least one of the boom assembly  195  and the frame  15 . The receiving device  305  is configured to receive a movable shaft  310  (e.g., sliding shaft, rotating shaft) coupled to at least one of the other of the boom assembly  195  and the frame  15 . In some embodiments, the receiving device  305  may be configured to receive a sliding block  315  or a rotating latch  320  or wedge  325 . The movable shaft  310  may be a hydraulic actuator  330  or an electronic actuator  335 . 
     Referring to  FIGS. 1, 4, 5A, 5B, 5C, 6A and 6B , an attachment  340  may be coupled to the attachment coupler  250 . The attachment  340  may be a bucket  345 , a dozer blade  350 , forks  355 , trencher  360 , or other attachment  340  (e.g., grapple, auger). The attachment  340  may comprise a cutting edge  365  ( FIG. 1 ). 
     With reference to  FIG. 4 , an attachment position sensor  370  may be coupled to at least one of the boom assembly  195 , the attachment coupler  250 , and the tilt cylinder  260  and configured to transmit an attachment position signal  375  ( FIG. 8 ) indicative of a position of the attachment coupler  250 . The attachment position sensor  370  may be a rotary sensor, cylinder position sensor, or other type of sensor. 
     An inertial measurement unit (“IMU”)  380  or a slope sensor  385  may be coupled to the attachment  340  and configured to transmit a slope signal  390  ( FIG. 8 ) indicative of a slope of the attachment  340  relative to the frame  15  or the surface  30 . Slope corresponds with the blade tilt right  175  and blade tilt left  180  in the updated configuration  110  ( FIG. 2B ) and dozer mode  120  ( FIG. 2B ). 
     With reference to  FIGS. 1 and 8 , an identification device  395  may be coupled to the attachment  340  and configured to transmit an attachment identification signal  400  after an activation event  405 . The identification device  395  may be a beacon assembly  410 . The attachment identification signal  400  may comprise attachment dimensions  415 . The activation event  405  may comprise the work vehicle  10  contacting the attachment  340  with a minimum force where the attachment  340  remains stationary. Alternatively, the activation event  405  may comprise the identification device  395  receiving an activation signal  420  from an activation sensor  425  coupled to the work vehicle  10 . The operator interface  50  or display  55  may be communicatively coupled to the identification device  395  and configured to display the attachment identification signal  400 . The operator interface  50 , display  55 , or the operator input device  60  may be configured to receive an operator input indicative of an attachment confirmation  430  and the grade command  70 . The operator interface  50  or display  55  may show the attachment identification signals  400  of the attachments  340  in order of the strength of the attachment identification signals  400  starting with the strongest signal of the various signals coming from a variety of attachments  340 . The operator interface  50  or display  55  may also show the attachment identification signals  400  of the attachments  340  starting with the most recently used or previously used attachments  340 . Other attachment identification signal  400  display orders are contemplated by this disclosure. 
     A positioning receiver  435  may be coupled to the frame  15  or operator&#39;s station  40  and configured to receive a geospatial positioning signal  440  (“GPS”) (e.g., GNSS, GLONASS) to locate a position of the work vehicle  10 . 
     A grade control system  445  may be communicatively coupled to the operator input device  60  and configured to receive the grade command  70  and define a cutting plane  450 . The grade control system  445  may be a laser  455  coupled to the frame  15  and configured to receive the grade command  70  and project the cutting plane  450  on the surface  30 . Alternatively, the grade control system  445  may be an internal on-board system  460  that does not project the cutting plane  450  but is communicatively coupled to the operator input device  60  and configured to receive the grade command  70 . 
     A controller  465  may be coupled to the work vehicle  10 . In dozer mode  120  ( FIG. 2B ), the controller  465  may be configured to receive an operator signal  470  from the operator interface  50 , transmit a boom lower signal  475  to the hydraulic system  275  to lower the boom assembly  195  to the frame  15 , and transmit a boom lock signal  480  to a hydraulic actuator  330  or an electronic actuator  335  of the boom lock  290  to move the boom lock  290  to the locked position  300  ( FIGS. 5A, 5B, 5C ) after the boom assembly  195  is lowered to the frame  15 . The controller  465  may receive and send signals wirelessly (e.g., Bluetooth) via a work vehicle wireless communication device  485  or by way of a communication bus  490 . The controller  465  may comprise an electronic data processor  495 . 
     The electronic data processor  495  may be arranged locally as a part of the work vehicle  10  or remotely away from the work vehicle  10 . In various embodiments, the electronic data processor  495  may comprise a microprocessor, a microcontroller, a central processing unit, a programmable logic array, a programmable logic controller, an application specific integrated circuit, a logic circuit, an arithmetic logic unit, or other suitable programmable circuitry that is adapted to perform data processing and/or system control operations. In other embodiments, the electronic data processor  495  can manage the transfer of data to and from a remote processing system via a network and wireless infrastructure. For example, the electronic data processor can collect and process signal data from the communication bus  490  for transmission either in a forward or rearward direction (i.e., to or from the remote processing system). 
     A memory device  500  stores information and data for access by the electronic data processor  495 , the communication bus  490 , or the vehicle wireless communication device  485 . The memory device  500  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. 
     For two-dimensional automatic control of the attachment  340 , the controller  465  may be configured to receive the geospatial positioning signal  440  from the positioning receiver  435 , the boom position signal  245 , the attachment position signal  375 , the operator signal  470  or input, and reference the memory device  500  and change the work vehicle control  90  between the standard configuration  105  and the updated configuration  110 . The controller  465  may be configured to control an elevation of the attachment  340  according to the grade command  70  by controlling the hydraulic system  275 . 
     Alternatively, for three-dimensional automatic control of the attachment  340 , the controller  465  may be configured to receive the geospatial positioning signal  440  from the positioning receiver  435 , the boom position signal  245 , the attachment position signal  375 , the slope signal  390 , the attachment identification signal  400 , the operator signal  470  or input, and change the work vehicle control  90  between the standard configuration  105  and the updated configuration  110 . The controller  465  may be configured to control an elevation and a slope of the attachment  340  according to the grade command  70 . 
     The controller  465  may be configured to control the hydraulic system  275  to control the elevation and the slope of the attachment  340  according to the grade command  70 . The controller  465  may be configured to control the hydraulic system  275  to maintain the cutting edge  365  on the cutting plane  450 . The controller  465  may be configured to receive the boom position signal  245 , the attachment position signal  375 , and the grade command  70 , and maintain the cutting edge  365  on the cutting plane  450  in both an operating position  505  ( FIG. 3 ) and a dump position  510  ( FIG. 7 ). 
     In operation, an operator may enter the operator&#39;s station  40  or access the work vehicle  10  remotely via the work vehicle wireless communication device  485  or the communication bus  490 . The operator may turn on the work vehicle  10  with the operator input device  60  such as the SSM  85 . The operator may move the work vehicle  10  towards an attachment  340  using the work vehicle control  90 . When the work vehicle  10  contacts, but before it moves the attachment  340 , the activation event  405  occurs and the identification device  395  sends the attachment identification signal  400 . Alternatively, the activation event  405  may occur when the activation sensor  425  sends the activation signal  420  to the identification device  395  causing the identification device  395  to send the attachment identification signal  400 . The operator interface  50  or display  55  may show the attachment identification signal  400  or, if more than attachment  340  is present with the identification devices  395  activated, the operator interface  50  or display  55  may show the attachment identification signals  400  in order of strength of the attachment identification signals  400  starting with the strongest signal representing the closest attachment  340  to the work vehicle  10 . 
     The operator would position the work vehicle  10  to couple to the attachment  340 . After the attachment  340  is coupled to the work vehicle  10 , the operator interface  50  or display  55  may request the operator to provide the operator input indicative of the attachment confirmation  430  or the grade command  70 . The operator interface  50  or display  55  may show the attachment dimensions  415  and the type of attachment  340  such as the bucket  345 , dozer blade  350 , the forks  355 , the trencher  360 , or other attachment  340  (e.g., grapple, auger) as a part of the attachment confirmation  430 . The operator may enter the operator input with the display  55  or the operator input device  60 . 
     If the attachment  340  is a dozer blade  350 , the operator may lock the boom assembly  195  to the frame  15  with the boom lock  290 . The operator may activate the boom lock  290  by entering the operator input with the operator interface  50  or display  55  or the operator input device  60  causing the controller  465  to receive the operator signal  470 . Upon receiving the operator signal  470 , the controller  465  may transmit the boom lower signal to the hydraulic system  275  to lower the boom assembly  195  to the frame  15 . The controller  465  may transmit the boom lock signal  480  to the hydraulic actuator  330  or the electronic actuator  335  to move the boom lock  290  to the locked position  300 . Once the dozer blade  350  is attached to the work vehicle  10  and the boom lock  290  is in the locked position  300 , the operator may provide operator input to the operator interface  50  or the operator input device  60  to select dozer mode  120  thus reconfiguring the work vehicle control  90  to be more like that of a standard dozer or crawler. 
     When the dozer blade  350  is coupled to the attachment coupler  250  a load path  515  does not pass through the lower links  205  of the boom assembly  195 . The load path  515  may pass through the dozer blade  350 , the boom assembly  295 , the boom lock  290 , and the frame  15 . The tilt cylinders  260  are configured to move or tilt the attachment  340  in both the unlocked position  295  and the locked position  300 . For example, in the locked position  300 , the tilt cylinders  260  may raise the attachment  340  off of the surface  30 . The tilt cylinders  260  may move the attachment  340  from the operating position  505  to the dump position  510 . As the attachment  340  is raised from the operating position  505  to the dump position  510 , the attachment  340  may be rotated to maintain the cutting edge  365  on the cutting plane  450 . For example, if the attachment  340  is the bucket  345 , the bucket  345  may be configured to dump and spread contents or a material in the dump position  510 . The standard configuration  105  may be for controlling the bucket  345  and the updated configuration  110  may be for controlling the dozer blade  350  or other attachments  340 . 
     The grade control system  445  may receive the grade command  70  and define the cutting plane  450 . The controller  465  may receive the grade command, the geospatial positioning signal  440 , the boom position signal  245 , the attachment position signal  375 , and the slope signal  390 , to automatically control the elevation and slope of the attachment  340  as the work vehicle  10  traverses the surface  30 . 
     A method for locking a boom assembly  195  of a work vehicle  10  to a frame  15  of the work vehicle  10  is illustrated in  FIG. 9A . In Step  520 , the boom assembly  195  is coupled to an attachment coupler  250  that is coupled to an attachment  340 . In Step  525 , the method further comprises providing a movable shaft  310  coupled to at least one of the boom assembly  195  and the frame  15 , providing a receiving device  305  coupled to at least one of the other of the boom assembly  195  and the frame  15 , moving the movable shaft  310  from an unlocked position  295  to a locked position  300  where the receiving device  305  receives the movable shaft  310 . In Step  530  the method comprises creating a load path  515  that passes through the attachment  340 , the attachment coupler  250 , the boom assembly  195 , the movable shaft  310 , the receiving device  305 , and the frame  15 . 
     In Step  535  the method further comprises providing a controller  465  to receive an operator signal  470  from an operator interface  50  positioned in an operator&#39;s station  40  coupled to the frame  15 , transmitting a boom lower signal  475  to a hydraulic system  275  configured to lower the boom assembly  195  to the frame  15 , and transmitting a boom lock signal  480  to a hydraulic actuator  330  or an electronic actuator  335  to cause the receiving device  305  to receive the movable shaft  310 . 
     In Step  540  the method comprises the attachment  340  is a dozer blade  350  and the load path  515  passes through the dozer blade  350 , the attachment coupler  250 , the boom assembly  195 , the movable shaft  310 , the receiving device  305 , and the frame  15 . 
     In Step  545  the method further comprises tilting the attachment  340  with at least one tilt cylinder  260  coupled to the boom assembly  195  and the attachment coupler  250  to raise the attachment  340  from a surface  30  without changing the load path  515 . 
     A method for maintaining a cutting edge  365  on a cutting plane  450  in both an operating position  505  and a dump position  510  of a work vehicle  10  is illustrated in  FIG. 9B . In Step  550  the method comprises providing a work vehicle  10  comprising a frame  15 , a boom assembly  195  coupled to the frame  15 , an attachment coupler  250  coupled to a distal portion  255  of the boom assembly  195 , and an attachment  340  coupled to the attachment coupler  250 . In Step  555  the method further comprises receiving a boom position signal  245  indicative of a position of the boom assembly  195 , receiving an attachment position signal  375  indicative of a position of the attachment coupler  250 , receiving a grade command  70  and defining a cutting plane  450 , and maintaining the cutting edge  365  on the cutting plane  450 . In Step  560  the method comprises maintaining the cutting edge  365  on the cutting plane  450  in the dump position  510  by rotating the attachment  340 .