Patent Publication Number: US-2023134217-A1

Title: Apparatus and method for limiting movement of a work machine

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     N/A 
     BACKGROUND 
     Proper coupling of implements to work vehicle are critical to precision applications such as grade control. Conventional methods of verifying attachment require an operator to visually inspect for an identifying red flag through openings in a coupling assembly cover; and manually pressing the implement down to confirm attachment. This common practice may become problematic if the operator running the vehicle remotely, the work vehicle is running autonomously, or if debris clogs the opening in the coupling assembly thereby impacting visibility of the flags. Therein lies an opportunity for confirming the coupling between the implement and the work vehicle with ease when operated, remotely, autonomously or with an operator present. 
     SUMMARY 
     A method and a work vehicle with a non-transitory computer readable medium is disclosed. The work vehicle comprises a frame, a lift system with a movable arm secured to the frame and a coupling assembly. The coupling assembly is coupled to the movable arm operable via a linear actuator and attachable to a work implement. A proximity sensor is operatively coupled to the lift system and configured to send a proximity signal representative of a position of a first surface on the coupling assembly with a second surface on the work implement. The linear actuator sensor is operatively coupled to the coupling assembly and configured to send an extension signal indicative of the linear actuator is extended. A monitoring system includes a controller having a non-transitory computer readable medium with program instructions. The program instructions are configured to receive the proximity signal from the proximity sensor which indicates a position of a first surface on the coupling assembly with the second surface on the work implement. The instructions then determine a first condition of the first coupling step based on the proximity signal received. The first coupling step includes a proximity sensor status change when the distance between the first surface and the second surface cross a threshold. The non-transitory computer readable medium is then configured to perform a curling operation with the lift system to latch a top portion of the work implement with the coupling assembly to fully engage the first surface and the second surface when the proximity sensor status changes. Next, the linear actuator on the coupling assembly retracts in a second coupling step. The retraction moves at least one protrusion on the coupling assembly towards engagement with a catch on the work implement. The controller on the work vehicle receives an extension signal from the linear actuator indicating a length the linear actuator is extended. The non-transitory computer readable medium determines a second condition of the coupling step based on the extension signal received. The second coupling step includes a coupling status change upon reaching an extension threshold. 
     The non-transitory computer readable medium may further instruct reversing movement of the linear actuator if the linear actuator fails to full extend. 
     The non-transitory computer readable medium may further comprise outputting a signal indicating completion of coupling the work implement with the work vehicle when both the proximity sensor status and the coupling status change. 
     The non-transitory computer readable medium may send a request signal to repeat a cycle through the program instruction if one or more of the proximity sensor status and the coupling status fails to change. The proximity sensor may be one or more of a magnetic sensor, a lidar, an ultrasonic sensor, and an image sensor. 
     The curling operation may engage the coupling assembly with the work implement at a first and a second contact area. Retracting the linear actuator of the coupling assembly creates a third contact area with the work implement. 
     The method of indicating coupling of a work implement to a work vehicle comprises receiving proximity signals from a proximity sensor indicative of a position of first surface on the coupling assembly with a second surface on the work implement. In a next step, the method includes determining a first condition of a first coupling step based on the proximity signal received, the first coupling step including a proximity sensor status change when a distance between the first surface and the second surface crosses a threshold. Next, the method performs a curling operation with the lift system to latch a top portion of the work implement and fully engage the first surface and the second surface when the proximity sensor status changes. Then the method includes retracting the linear actuator on the coupling assembly in a second coupling step, the retraction moving at least one protrusion on the coupling assembly towards engagement with a catch on the work implement; and receiving an extension signal from the linear actuator sensor indicative of the length the linear actuator is extended. Finally, the method includes determining a second condition of the second coupling step based on the extension signal received, the second coupling step including a coupling status change upon reaching an extension threshold. 
     Other features and aspects of the disclosure will become apparent by consideration of the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is side elevation view of a work vehicle shown as a skid steer with an implement in the form of a bucket coupled thereto via a coupling assembly according to an embodiment in the disclosure. 
         FIG.  2    is a side view of a forward portion of the work vehicle shown in  FIG.  1   . 
         FIG.  3    is a partial elevated view perspective view of the forward portion of the work vehicle with the backside of the coupling assembly of  FIG.  1   . 
         FIG.  4    is a detailed perspective view of a movable arm, a coupling assembly, and the implement of  FIG.  1    illustrating the coupling assembly engaged with the implement. 
         FIG.  5 A  is a detailed rear view of the external surface of the coupling assembly in an unlocked position wherein the coupling assembly includes the quick attach cover. 
         FIG.  5 B  is a detailed rear view of the external surface of the coupling assembly in a locked position wherein the coupling assembly includes the quick attach cover. 
         FIG.  6 A  is a detailed rear view of the coupling assembly in an unlocked position wherein the coupling assembly does not include the quick attach cover. 
         FIG.  6 B  is a detailed rear view of the coupling assembly in a locked position wherein the coupling assembly does not include the quick attach cover. 
         FIG.  7    is a flow diagram illustrating conditional states for indicating whether the implement of  FIG.  1    is securely coupled to the coupler. 
     
    
    
     DETAILED DESCRIPTION 
     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 supporting other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     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 “one or more of” or “at least one 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). 
     As used herein, the term “controller” is a computing device including a processor and a memory. The “controller” may be a single device or alternatively multiple devices. The controller may further refer to any hardware, software, firmware, electronic control component, processing logic, processing device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
     The term “processor” is described and shown as a single processor. However, two or more processors can be used according to particular needs, desires, or particular implementations of the controller and the described functionality. The processor may be a component of the controller, a portion of the object detector, or alternatively a part of another device. Generally, the processor can execute instructions and can manipulate data to perform the operations of the controller, including operations using algorithms, methods, functions, processes, flows, and procedures as described in the present disclosure. 
       FIGS.  1 - 2    illustrate an embodiment of a work vehicle  100 . The work vehicle  100  is shown as a skid steer but may be, for example, a front end load, a backhoe, a tractor, a riding lawn mower, or other work vehicle with coupling capacity to an implement  116 . The work vehicle  100  includes a frame  106 , a power source, a lift system  113  and a coupling assembly  118  for attaching an implement  116  to the work vehicle  100 . The lift system  113  of the exemplary embodiment, includes a movable arm  114  on each side of the frame  106  (one each on a left side and a right side) pivotally coupled to the frame  106  and moveable relative to the frame  106  by a pair of boom linear actuators (not shown). The implement  116 , detachably coupled to the work vehicle via the coupling assembly  118  as will be described further herein, may be moved in a direction of pitch by actuating a pair of tilt actuators  120  (shown in  FIG.  4   ) and boom linear actuators of the lift system  113 . The pair of boom linear actuators may also be conventionally referred to as a pair of lift cylinders (one coupled to each movable arm  114 ) for a skid steer enabling movement of the implement  116  in either a radial direction or a vertical direction. The coupling assembly  118  may be coupled to a forward section, or portion, of the pair of movable arms  114 . The coupling assembly  118  may be moveable relative to the frame  110  by a pair of tilt actuator assemblies  120  in a direction of pitch  190 . Note, in other embodiments, such as an excavator, the arm  114  may be a single boom arm coupled to the frame of the work vehicle  100 . 
     The lift system  113  serves to manipulate the implement  116 , described and illustrated herein as a bucket. Other exemplary implements  116  may include a grapple, a scraper, a pallet fork, a snowplow, or the like for performing a specific task. 
     In operation, a work vehicle operator may wish to exchange a first implement  116  in use with the work vehicle  100  for a second implement  116 .  FIGS.  3  and  4    detail the area the coupling assembly attaches to one or more of the movable arms  114  and the frame  106 . An overhang, hook, or catch  134  defined in a portion of the implement  116  is sized to receive a protrusion  136  on the coupling assembly  118 . The coupling of the protrusion  136  with the overhang or hook  134  is a first attachment area  305 . 
     A proximity sensor is  310  operatively coupled to a portion of the lift system  113  and configured to send a proximity signal  315  representative of a position of a first surface  320  on the coupling assembly  118  with a second surface on  330  the implement  116 . That is, the proximity sensor  310  verifies if the gap between the implement  116  and the surface  320  of the coupling assembly  118  falls within the range to enable coupling at the first attachment area  305 . In the exemplary embodiment shown, the first surface  320  is a forward surface of the coupling assembly  118 , and the second surface  330  is a rear surface on the implement  116 . The proximity sensor  310  may be one or more of a magnetic sensor, an ultrasonic sensor, a lidar, an image sensor, or any other means of detection not requiring contact. This advantageously eliminates the physical requirement of contact such as compression of a button, or the visual verification by the operator sitting in an operator cab, for coupling at this first area of attachment  305 . 
     Now turning to  FIGS.  5 A  (locked position) and  5 B (unlocked position), a cross-sectional view of the coupling assembly  118  with implement  116  with the quick attach cover  335  is shown. The quick attach cover  335  protects the inner mechanism from impact damage, jamming due to introduction of contaminants such as dirt, and the like. As seen in  FIG.  5 B , a conventional method of verifying coupling at the third attachment area  340  (i.e. the locking mechanism) requires the operator to look for colored flags  345  (shown cross-hatched) through openings on the quick attach cover  335 . Another conventional method includes placing an upward vertical force on the implement by lowering the movable arms  114 , pressing the implement  116  against the ground to check for detachment. However, both of these methods may be inaccurate or difficult to confirm at times because debris from the environment may obscure visibility of the flag  345 , or alternatively if debris cakes onto a surface of the implement  116  or coupling assembly  118 , coupling may be partial or incomplete because the debris may h the first surface  320  and the second surface  330  from engaging with the functional range.  FIGS.  6 A and  6 B  illustrate the inner mechanism of the coupling assembly  118  without the quick attach cover shown  335  in  FIGS.  5 A and  5 B . The coupling assembly  118  include locking arms  610  operably movable between a retracted position ( FIG.  6 A ) and an extended position ( FIG.  6 B ) by the linear actuator  605 . As the linear actuator  605  of the coupling assembly  118  extends, the pivotable links  615  with red flags  345  rotates. One or more resilient members (e.g. a spring) are positioned such that the locking arms  610  are biased toward the extended position once the linear actuator  605  is extended, thereby reinforcing coupling with the implement  116  at the third attachment area  340 . The locking arms  610  extend through an aperture  620  of the quick attach cover  335  to detachably couple with the implement  116 . That is, the linear actuator  605  activates to rotate the locking arms  610  toward one of the retracted  635  or extended position  640 . 
     Furthermore, in operation, an implement  116  may be disconnected from the coupling assembly  118  on the work vehicle  100 . To do so, the work vehicle positions the implement  116  on the ground. The locking arms  610  are then moved to the retracted position by actuating the linear actuator  605  to a retracted state  635 , thereby moving the locking arms  610  clear of the latch on the implement  116 . Once the locking arms  610  are retracted, the work vehicle may manipulate the coupling assembly  118  relative to the frame by actuating the tilt actuator assemblies  120  to pivot the coupling assembly  118  relative to the implement  116 . 
       FIG.  7    illustrates a method and conditional states for identifying whether an implement  116  is properly secured to the coupling assembly  118  using a monitoring system having a non-transitory computer readable medium having program instructions. Specifically, when the work vehicle is in use, the controller  104  (or its processor) has program instructions that may be iterative. Using the controller  104 , the method  700  includes receiving data/signals from sensors to determine the coupling status of the implement. In a first step  705 , initiating coupling of the implement with the work vehicle is initiated by either an operator, or through a sequence of work instructions if done autonomously. In step  710 , the processor may receive a proximity signal  315  from the proximity sensor indicative of a position of a first surface  320  on the coupling assembly  118  with a second surface  330  on the implement  116 . In step  715 , the processor may then determine a first condition of a first coupling step based on the proximity signal  315  received. The first coupling step includes iteratively receiving the proximity signal  315  until a proximity sensor status change occurs. The proximity sensor status changes when the distance between the first surface and the second surface crosses a threshold, the threshold indicating sufficient proximity between both surfaces for engagement. The processor in step  720 , performs a curling operation with the lift system of the work vehicle to latch a top portion of the work implement with the coupling assembly and fully engage the first surface and the second surface. The curling operation engages the coupling assembly with the work implement at a first and a second contact area. That is full engagement ensures the first and the second contact areas are sufficiently flush with one another such that the next step of extending the linear actuator on the coupling assembly in a second coupling step safeguards the locking of the implement with the coupling assembly. In step  725 , the extension of the linear actuator sequentially moves the locking arms on the coupling assembly towards engagement with a catch  134  on the work implement. Extending the linear actuator of the coupling assembly creates a third contact area with the work implement. As this occurs, the processor in step  730  receives an extension signal from the linear actuator sensor  607  indicative of a length the linear actuator is extended. In step  735 , the processor determines a second condition of the second coupling step based on the extension signal received, the second coupling step including a coupling status change upon reaching an extension threshold. That is, if the processor determines that the proximity sensor is in a closed state, and that the linear actuator is fully extended (through the linear actuator sensor  607 ), the processor identifies that the work implement is in a “attached and connected” configuration. 
     In step  740 , the monitoring system  700  further comprises reversing movement of the linear actuator  605  of the coupling assembly  118  if the coupling status fails to change when the linear actuator fails to fully extend. The processor sends a request signal to repeat a cycle through the program instructions if one or more of the proximity sensor  310  status and the coupling status fail to change. 
     However, in step  745 , if the processor receives a coupling status change, indicating the linear actuator  605  is fully extended, the processor outputs a signal indicating completion of the attachment of the work implement  116  to the work vehicle  100 . 
     The reversal is true as well. The controller  104  continuously receives data/signals from the proximity sensor  310  and the linear actuator sensor  607  during and/or after detachment. If the controller  176  determines through the first and the second conditions have changed, the controller  104  identifies as in the ‘unattached and retracted’ configuration. 
     Although the given example begins with the controller  104  identifying the coupling of the implement  116  using the monitoring system  700  in the ‘attached and connected’ configuration C 1 , the controller  104  may execute program instruction when the monitoring system  700  is in either of attachment or detachment process. For instance, rather than a work vehicle operator wishing to exchange a first implement  116  for a second implement  116 , a work vehicle operator may bring the work vehicle  100  out of storage, in which case the work vehicle  100  may not have an implement  116  securely coupled or attached to the coupling assembly  118 . In this instance, with the linear actuator  605  may be in the retracted position, and the controller  104  may cycle through the program instructions from the beginning. 
     Various features of the disclosure are set forth in the following claims.