Patent Publication Number: US-2023160171-A1

Title: System and method to support rotation operation of work tool

Description:
TECHNICAL FIELD 
     The present disclosure relates to work machines, and more particularly to construction machines equipped with a tilt rotator and a quick coupler, and systems, assemblies, and methods thereof. 
     BACKGROUND 
     Work machines, particularly those in construction, mining, earth moving, goods handling, forestry, agriculture, or other such industries, typically utilize a tool controlled by an operator to perform work. A variety of tools may be attached to an arm arrangement of a multipurpose machine via a coupling arrangement for performing different types of work. 
     The coupling arrangement may comprise a quick coupler, which can allow coupling and decoupling between a tool and the work machine in a particularly efficient and quick operation. The quick coupler typically may be controlled by an operator from a cabin of the work machine via a control system and associated actuators. The coupling arrangement may further comprise a tilt rotator, which can enable controlled rotation of the tool about a rotational axis and controlled tilt of the tool relative to a tilt axis. By way of the tilt rotator, flexible movement of the tool can be provided during operation of the work machine. 
     To safely attach the tool to the quick coupler or detach the tool from the quick coupler, it may be required to arrange the tilt rotator and the tool in an appropriate position during attachment or detachment of the tool. 
     U.S. Published Patent Document US2021/0095441A1 (“the US &#39;441 Publication”) describes an excavator provided with a tilt rotator and an excavator thumb, which may be pivotally attached to an arm of the excavator. According to the US &#39;441 Publication, a control system may be arranged to block maneuvering input for movement of at least one of the tilt rotator and the excavator thumb to reduce a risk of damaging the equipment. Also, the US &#39;441 Publication describes a quick command to put a tool in a correct position for cooperation with the excavator thumb. 
     However, for safety during attachment/detachment of the tool, it has been desired to be able to control a series of processing of rotation operation of the tilt rotator and rollup operation of the tool by guiding the operator&#39;s operation appropriately, in addition to automatically performed operation. 
     SUMMARY 
     According to an aspect a work machine is described or provided. The work machine can comprise a tilt rotator to control rotation of a tool about a rotational axis and to control tilt of the tool about a tilt axis, a coupler to couple and decouple the tool to/from the tilt rotator, a display to output information to an operator of the work machine, an operator interface to receive input from the operator, and processing circuitry. The processing circuitry is configured to output, on the display, a rotation instruction for the operator to initiate a rotation operation of the tilt rotator, in a case that the tilt rotator is determined to be in an incorrect position based on a rotation angle of the tilt rotator about the rotational axis, stop the rotation operation of the tilt rotator under a condition that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator about the rotational axis, the rotation operation being initiated by a rotation input via the operator interface, output, on the display, a rollup instruction for the tool to initiate a rollup operation. 
     In another aspect, a method for a work machine is disclosed or implemented. The method can comprise detecting a rotation angle of a tilt rotator, the tilt rotator controlling rotation of a tool about a rotational axis and controlling tilt of the tool about a tilt axis; outputting, on the display, a rotation instruction for the operator to initiate a rotation operation of the tilt rotator, in a case that the tilt rotator is determined to be in an incorrect position based on a rotation angle of the tilt rotator about the rotational axis; and stopping the rotation operation of the tilt rotator under a condition that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator about the rotational axis, the rotation operation being initiated by a rotation input via the operator interface. 
     And in another aspect a control system is disclosed or provided. The control system can comprise circuitry configured to detect a rotation angle of a tilt rotator, the tilt rotator controlling rotation of a tool about a rotational axis and controlling tilt of the tool about a tilt axis, output rotation instruction of the tilt rotator on a display, in a case that the tilt rotator is determined to be in an incorrect position based on the rotation angle of the tilt rotator, detect rotation operation of the tilt rotator, in response to a rotation input via an operator interface, automatically stop the rotation operation of the tilt rotator in a case that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator, and output rollup instruction of the tool on the display. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a side elevational view of a work machine according to one or more embodiments of the disclosed subject matter. 
         FIG.  2    is an exploded perspective view of a coupling arrangement comprising a tilt rotator and a quick coupler of the work machine of  FIG.  1    according to one or more embodiments of the disclosed subject matter. 
         FIGS.  3 A and  3 B  show top plan views of the work machine of  FIG.  1    according to one or more embodiments of the disclosed subject matter. 
         FIGS.  4 A and  4 B  show front elevational views of the coupling arrangement from a cabin of the work machine according to one or more embodiments of the disclosed subject matter. 
         FIG.  5    is a block diagram illustrating a configuration of an information processing or control system according to embodiments of the disclosed subject matter. 
         FIG.  6    is a flowchart of a method according to one or more embodiments of the disclosed subject matter. 
         FIG.  7    is a flowchart of a method according to one or more embodiments of the disclosed subject matter. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to work machines, and more particularly to construction machines equipped with a tilt rotator and a quick coupler, and systems, assemblies, and methods thereof. Generally, embodiments of the disclosed subject matter can implement the work machine that can guide an operator to control rotation operation of the tilt rotator until the machine detects a correct position of the tilt rotator, and/or that can guide the operator to control rollup operation of the tool, for instance, to avoid an unsafe condition during the attachment/detachment of the tool. 
     Turning to the figures,  FIG.  1    is a side elevational view of a work machine according to one or more embodiments of the disclosed subject matter. The work machine  1  may comprise a body  10  and an arm arrangement  30  to which a tool  15  may be connected via a coupling arrangement  60 . 
     The body  10  of the work machine  1  can be or include a chassis, frame, and exterior panels of the work machine  1  and can be configured to support and house various components of the work machine  1 , such as an engine  11 , a pump  12 , tracks  13 , and a cabin  14 . 
     The engine  11  can be a combustion, electric, or other type of engine configured to produce mechanical energy. The pump  12  can be a hydraulic pump connected to the engine  11  and can be powered thereby. In some examples, the pump  12  can be connected to one or more valves for controlling and distributing hydraulic fluid to various hydraulic actuators of the work machine  1 , such as a first hydraulic actuator  18 , a second hydraulic actuator  19 , and a third hydraulic actuator  21 . The tracks  13  can be a set of movable tracks powered by the engine  11  and connected to the body. The tracks  13  can be operable by the engine  11  to move the work machine. 
     The cabin  14  can be connected to the body  10  and configured to enclose an operator therein. For example, the cabin  14  can include an operator&#39;s seat  101 , a monitor  102 , an operator interface  103  (e.g., an operation lever such as a joystick) and a control system for controlling the operation of the engine  11 , the pump  12 , the tracks  13 , and the arm arrangement  30  and the coupling arrangement  60  to control the tool  15  (e.g., a bucket). In the embodiment, the operator of the work machine  1  can receive information shown on the monitor  102  and appropriately control the work machine  1  by the operator interface  103 , for instance, a switch  104  which may be mounted on the operator interface  103 . The switch  104  on the operator interface  103 , as used herein, can include only one switch or multiple switches. The cabin  14  may further comprise foot pedals and one or more switches arranged inside cabin  14  to control the work machine  1 . The detail of the control system will be described with reference to  FIG.  5   . 
     The arm arrangement  30  may comprise a boom  16 , which may be referred as a first arm, pivotally attached to the body  10 , and a stick  17 , which may be referred as a second arm, pivotally attached to the boom  16 . The boom  16  can be connected to the body  10  and the stick  17 , and the stick  17  can further be connected to the coupling arrangement  60 . Each of the first hydraulic actuator  18 , the second hydraulic actuator  19 , and the third hydraulic actuator  21  can be connected to and powered by the pump  12 , as noted above. The first hydraulic actuator  18  can be connected to the body  10  and the boom  16 ; the second hydraulic actuator  19  can be connected to the boom  16  and the stick  17 ; and the third hydraulic actuator  21  can be connected to the stick  17  and the coupling arrangement  60 . 
     The arm arrangement  30  may also comprise a linkage arrangement  20 , which may enable the coupling arrangement  60  to be pivotally attached to the arm arrangement  30 , particularly to the stick  17 . The third hydraulic actuator  21  may be connected between the stick  17  and linkage arrangement  20  to pivot the linkage arrangement  20  and the coupling arrangement  60  relative to the stick  17 . The linkage arrangement  20  may comprise at least one first link  22  pivotally attached to the third hydraulic actuator  21  and the stick  17 . The linkage arrangement  20  may comprise at least one second link  23  pivotally attached to the coupling arrangement  60  and pivotally attached to the third hydraulic actuator  21  and at least one first link  22 . 
     The coupling arrangement  60  may comprise the tilt rotator  40  and a quick coupler  50  to couple the tool  15  of the work machine  1  at one end. The quick coupler  50  may be an assembly to easily couple an attachment (e.g., the tool  15 ) without using a conventional fastening member (e.g., bolt), for shortening replacement time required for replacing the attachment. The arrangement of the tilt rotator  40  and the quick coupler  50  will be described with reference to  FIG.  2   . 
     The tool  15  may be attached to the arm arrangement  30  of the work machine  1  via the coupling arrangement  60  for performing various types of work. It is noted that embodiments of the disclosed subject matter are not limited to a bucket as the tool  15  as shown in  FIG.  1   . For instance, embodiments of the disclosed subject matter can include any other suitable accessories or tools than a bucket, such as such as a fork, hammer, plow, handling arm, multi-processor, pulveriser, saw, shears, blower, grinder, tiller, compactor, trencher, winch, auger, blade, broom, cutter, planer, delimber, felling head, grapple, mulcher, ripper, or the like. 
     In operation of some examples, an operator can use the controls within the cabin  14  to move the work machine  1  using the tracks  13 . The operator can further articulate the boom  16  and the stick  17  to position the tool  15  relative to the body  10 . The operator can control to use the tilt rotator  40  to tilt, rotate, and scoop or curl the tool  15  to perform various tasks, such as moving dirt and other materials during an excavating process. 
       FIG.  2    is an exploded perspective view of a coupling arrangement comprising the tilt rotator  40  and the quick coupler  50  of the work machine of  FIG.  1    according to one or more embodiments of the disclosed subject matter. As shown in  FIG.  2   , the coupling arrangement  60  may comprise the tilt rotator  40  and the quick coupler  50  coupled to the lower end of the tilt rotator  40 . The lower end of the tilt rotator  40  may comprise a rotatable manipulator table  44 , to which the quick coupler  50  can be fastened. The tilt rotator  40  may further comprise tilting cylinders  41   a  and  41   b  to tilt the quick coupler  50  up to a predetermined angle (e.g., 40 degrees). The tilt rotator  40  may further comprise a rotating actuator  43  to actuate the rotatable manipulator table  44  about a predefined range (e.g., 360 degrees), for example by hydraulic power. 
     The tilt rotator  40  may comprise an upper attachment part  42  to hold interaction with an upper fastening part  31  of the arm arrangement  30 , which can be attached to the end of the stick  17 . The upper attachment part  42  may comprise at least one intermediate coupling element  45  corresponding to at least one first coupling element  35  of the upper fastening part  31  of the arm arrangement  30 . As one embodiment of the subject matter,  FIG.  2    shows that the upper attachment part  42  can comprise intermediate coupling elements  45   a  and  45   b  each corresponding to first coupling elements  35   a  and  35   b  of the upper fastening part  31 , respectively. 
     The upper fastening part  31  and the upper attachment part  42  may be configured to selectively engage the first and intermediate coupling elements  35   a ,  35   b ,  45   a ,  45   b , so as to couple the arm arrangement  30  to the coupling arrangement  60 . 
     As is evident from  FIG.  2   , at least one of the intermediate coupling elements  45   a  and  45   b  of the upper attachment part  42  of the tilt rotator  40  may be an attachment pin, wherein the at least one of the intermediate coupling elements  45   a  and  45   b  can be arranged to fit in a corresponding recess provided by at least one of the first coupling elements  35   a  and  35   b  of the upper fastening part  31 . In the corresponding way, the quick coupler  50  of the coupling arrangement  60  may comprise at least one second coupling element  51  (e.g., an attachment pin) to attach and detach the tool  15 . The tool  15  may comprise at least one tool coupling element  52  (e.g., a recess) to be selectively connected with the at least one second coupling element  51 . As one embodiment of the subject matter,  FIG.  2    shows that the quick coupler  50  can comprise the second coupling elements  51   a ,  51   b ,  51   c  and  51   d  corresponding to the tool coupling elements  52   a ,  52   b  and  52   c  of the tool  15 . 
     In particular, the quick coupler  50  may comprise at least one locking actuator to selectively engage the at least one second coupling element  51  with the at least one tool coupling element  52 . For example, the at least one locking actuator may be configured to extend or retract the pin provided by the second coupling element  51 , from the recess provided by the tool coupling element  52 . The pin may be spring biased into the extended orientation. The locking actuator may comprise an electric actuator, such as an electronically activated solenoid, and/or a hydraulic actuator, such as a piston and cylinder. The at least one second coupling elements  51  and at least one tool coupling element  52  may be of any other suitable type known in the art and may, for example, comprise at least one wedge, pin, hook or the like. Some of the at least one second coupling elements  51  and at least one tool coupling element  52  may be configured to only provide support during coupling and are not actuatable. For example, one or more of the at least one second coupling elements  51  and at least one tool coupling element  52  may comprise corresponding fixed pin(s) or wedge(s) and support recess(es) or mount(s). 
     In this embodiment, by the at least one locking actuator of the quick coupler  50  and a locking attachment (e.g., spring), the tool  15  can be coupled to the tilt rotator  60  in a lock state so that the locking actuator (e.g., cylinder) cannot move by unintentional cause. On the other hand, the quick coupler  50  can be unlocked by releasing the locking attachment from the at least one locking actuator of the quick coupler  50 , and the tool  15  may be detachable when the quick coupler  50  is unlocked (i.e., in an unlock state). The transition between the lock state and the unlock state of the quick coupler  50  may be controlled by the control system which will be described with reference to  FIG.  5   . 
     It is noted that embodiments of the disclosed subject matter are not limited to the specific arrangement of the coupling elements as shown in  FIG.  2   . For instance, embodiments of the disclosed subject matter can include more or less coupling elements to engage the quick coupler  50  and the tool  15 . 
     Here, when the work machine  1  attaches or detaches the tool  15  to or from the quick coupler  50 , the position of the tool  15  relative to the work machine  1  may be regulated by a certain rule (or rules) in a work area. For example, in North America, it may be regulated that the tool  15  should be faced the front surface of the body  10  of the work machine  1  without rotation angles or tilt angles by the tilt rotator  40  and curled up, when the tool  15  is attached to and/or detached from the quick coupler  50 . In that area, if the tool  15  is detached from the quick coupler  50  in an incomplete state (e.g., the tool  15  is rotated and/or tilted, i.e., offset from the correct position(s)), it may cause unsafe condition, such as an unexpected fall of the tool  15  from the quick coupler  50 . 
     On the other hand, it may be hard for the operator of the work machine  1  to stop the tilt rotator  40  in the correct position completely by a manual maneuvering operation. Therefore, an appropriate support by the work machine  1  to the operator to control the tilt rotator  40  in the correct position may be desired. 
     Turning now to  FIGS.  3 A and  3 B ,  FIGS.  3 A and  3 B  show a top plan view of the work machine  1  according to one or more embodiments of the disclosed subject matter. 
       FIG.  3 A  shows the top plan view of the work machine  1  when the tilt rotator  40  is in the correct position (about a rotational axis  72 ). More specifically, in the correct position, a tool vertical reference plane (i.e., a face  70  of the tool  15 ) may face a front surface  71  of the body  10  of the work machine  1  as shown in  FIG.  3 A . For instance, the face  70  of the tool  15  and the front surface  71  of the body  10  of the work machine  1  may be in parallel without any rotation angles with respect to the rotational axis  72  in a plane which is given by X- and Y- coordinates as shown in  FIG.  3 A . 
     Alternatively, in case that the front surface  71  of the body  10  of the work machine  1  may not be straight, the correct position of the tool  15  in the top plan view may be defined by the face  70  of the tool  15  being orthogonal to a forward running direction of the work machine  1 , or the face  70  of the tool  15  may be perpendicular to the boom  16  of the work machine  1 . 
     Optionally or alternatively, in case that the face  70  of the tool  15  may not be straight, the tool vertical reference plane may be defined with other values, such as reference values of coordinates in the X- and Y- coordinates. 
       FIG.  3 B  shows the top plan view of the work machine  1  when the tilt rotator  40  is in a rotated position, i.e., an incorrect position (about the rotational axis  72 , for instance, offset from a predetermined rotation angle). More specifically, in  FIG.  3 B , the face  70  of the tool  15  can be rotated with respect to the rotational axis  72  at a rotation angle  73 . In other words, the rotation angle  73  may be an angle between the face  70  of the tool  15  and the front surface  71  of the body  10  of the work machine  1  in the plane which is given by X- and Y- coordinates as shown in  FIG.  3 B . In the embodiment, the rotation angle  73  can be implemented as 360 degrees. 
     Alternatively, in case that the front surface  71  of the body  10  of the work machine  1  may not be straight, the rotation angle  73  can be defined as the angle rotated from a plane which may be orthogonal to a forward running direction of the work machine  1 , or a plane may be perpendicular to the boom  16  of the work machine  1 , in the top plan view of the work machine  1 . 
     In this embodiment, the rotated position of the tilt rotator  40  about the rotational axis  72  as shown in  FIG.  3 B  may be determined as the incorrect position, for example, which is not suitable for a bucket close/curl operation in case that the tool  15  is a bucket, since the bucket does not face the front of the work machine  1 . 
     Optionally or alternatively, the correct position of the tilt rotator  40  in the top plan view of the work machine  1  can be defined as a range of the rotational angle  73  which is less than a predetermined threshold value. In that case, the incorrect position of the tilt rotator  40  in the top plan view of the work machine  1  may be defined as a range of the rotational angle  73  which is equal to or larger than the predetermined threshold value. 
     Turning now to  FIGS.  4 A and  4 B ,  FIGS.  4 A and  4 B  show a front elevational view of the coupling arrangement  60  from the cabin  14  of the work machine  1  according to one or more embodiments of the disclosed subject matter. In both of  FIGS.  4 A and  4 B , the tool  15  may be arranged in the correct position in the top plan view of the work machine  1  as  FIG.  3 A , so the face  70  of the tool  15  may face the front surface  71  of the body  10  of the work machine  1 . Alternatively, in case that the front surface  71  of the body  10  of the work machine  1  may not be straight, the face  70  of the tool  15  may be orthogonal to a forward running direction of the work machine  1 , or the face  70  of the tool  15  may be perpendicular to the boom  16  of the work machine  1 . 
       FIG.  4 A  shows the front elevational view of the coupling arrangement  60  from the cabin  14  of the work machine  1  when the tilt rotator  40  is in the correct position (about a tilt axis  75 ). For instance, in the correct position in the front elevational view of the coupling arrangement  60  from the cabin  14  of the work machine  1 , a tool horizontal reference plane (e.g., a top surface  74  of the tool  15 ) may be parallel to the ground without any tilt angles with respect to the tilt axis  75  in a plane which is given by X- and Z- coordinates as shown in  FIG.  4 A . 
     Optionally or alternatively, in case that the top surface  74  of the tool  15  may not be straight, the tool horizontal reference plane may be defined with other values, such as a surface of the rotatable manipulator table  44 , or reference values of coordinates in the X- and Z- coordinates. 
       FIG.  4 B  shows the front elevational view of the coupling arrangement  60  from the cabin  14  of the work machine  1  when the tilt rotator  40  is in the tilted position, i.e., an incorrect position (about the tilt axis  75 , for instance, offset from a predetermined tilt angle). More specifically, in  FIG.  4 B , the top surface  74  of the tool  15  can be tilted with respect to the tilt axis  75  at a tilt angle  76 . In other words, the tilt angle  76  may be an angle of the top surface  74  of the tool  15  from a horizontal plane may in the plane which is given by X- and Z- coordinates as shown in  FIG.  4 B . In the embodiment, the tilt angle  76  can be implemented as 40 degrees at maximum in each side of the tilt rotator  40 . 
     It is noted that embodiments of the disclosed subject matter are not limited to the specific arrangement of the tilt angle  76  as shown in  FIG.  4 B . For instance, embodiments of the disclosed subject matter can arrange the tilt angle  76  in different values based on the type of the tool  15 . 
     Alternatively, in case that the ground may not be straight, the tilt angle  76  can be defined as the angle tilted from a plane which may be parallel to a horizontal direction, or a plane may be parallel to a bottom surface of the stick  17  of the work machine  1 , in the front elevational view of the coupling arrangement  60  from the cabin  14  of the work machine  1 . 
     Optionally or alternatively, the correct position of the tilt rotator  40  in the front elevational view of the coupling arrangement  60  can be defined as a range of the tilt angle  76  which is equal to or less than a predetermined threshold value. In that case, the incorrect position of the tilt rotator  40  in the front elevational view of the coupling arrangement  60  may be defined as a range of the tilt angle  76  which is larger than the predetermined threshold value. 
     Turning now to  FIG.  5   ,  FIG.  5    shows a block diagram illustrating a configuration of an information processing system  81  of the work machine  1  according to one or more embodiments of the disclosed subject matter. As illustrated in  FIG.  5   , the information processing system  81  can include an input unit  82 , a communication unit  83 , a storage unit  84 , a display unit  85 , an audio unit  86 , a sensor unit  87 , and a controller  88 . Controller  88 , as used herein, can include only one controller or multiple controllers. 
     The input unit  82  can have a function of receiving an input of operation information from a user of the information processing system  81 . In this embodiment, for example, the input unit  82  can be implemented as the operator interface  103 , the switch  104  on the operator interface  103 , a touch panel of the monitor  102 , foot pedals, other switches and a keyboard arranged in the cabin  14  shown in  FIG.  1   . For instance, the input unit  82  can receive input information of rotation operation of the tilt rotator  40  provided by the operator, via the switch  104 , and transmit the input information to the controller  88 . Also, the input unit  82  can receive input information of attachment/detachment of the tool  15  from the quick coupler  50  provided by the operator, via the switch  104  or the other switches, and transmit the input information to the controller  88 . 
     The communication unit  83  can have a communication interface that has a function as a transmitter and a receiver performing communication with an external apparatus, on the basis of the control from the controller  88 . In this embodiment, the communication unit  83  can be configured using a communication device such as a local CAN, a wired or wireless LAN, a communication card for Bluetooth, a router for communication, and a modem for communication. 
     The storage unit  84  can have a function of storing a variety of information used by the controller  88 . For example, the storage unit  84  can store position information of the tilt rotator  40 , such as the rotation angle and/or the tilt angle, and input information acquired by the input unit  82 . The storage unit  84  also can store a predetermined rotation angle and/or a predetermined tilt angle for comparison to the rotation angle and/or the tilt angle of the movement of the tilt rotator  40 . The storage unit  84  can be configured using a storage device such as a magnetic storage device, a semiconductor storage device, and an optical storage device. 
     The display unit  85  can have a function of displaying a variety of information, on the basis of control from the controller  88 . For example, the display unit  85  can display the input information acquired by the input unit  82 , and guidance information or a message to guide the operator to execute a certain operation of the work machine  1 . The display unit  85  can be configured using a display device such as a liquid crystal display, a plasma display, and an organic EL display. The display unit  85  can be implemented as the monitor  102  and can be equipped with a touch panel to input information to the controller  88 . Optionally, the display unit  85  can display virtual movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15  in 3D space in synchronization with real-time-time movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15 . In this embodiment, optionally, the display unit  85  can display indication that may include or be part of instruction to the operator of the work machine  1  to initiate the rotation operation and/or the rollup operation. 
     The audio unit  86  can have a function of outputting sound based on control from the controller  88 . In this embodiment, the audio unit  86  can be implemented as a horn or a speaker of the work machine  1 . In this embodiment, optionally, the audio unit  86  can output sound that may include or be part of instruction to the operator of the work machine  1  to initiate the rotation operation and/or the rollup operation. 
     The sensor unit  87  can detect various information of the work machine  1 . For example, a triaxial acceleration sensor (including an acceleration sensor, a gravity detection sensor, and a fall detection sensor) or a triaxial gyro sensor (including an angular velocity sensor, and a geomagnetic sensor) can be used as the sensor unit  87 . In this embodiment, the sensor unit  87  can detect the rotation angle  73  and the tilt angle  76  of the tilt rotator  40  shown in  FIGS.  3 B and  4 B . 
     The controller  88  can have a function of controlling an entire operation of the information processing system  81  (i.e., the work machine  1 ). For example, the controller  88  can control the operation of the work machine  1 , on the basis of the operation information output from the input unit  82 . The controller  88  can include a CPU, a ROM, and a RAM. 
     In an exemplary implementation, information processing system  81  of the work machine  1 , or portions thereof, can be implemented using circuitry or processing circuitry that can include general purpose processors, special purpose processors, integrated circuits, ASICs (“Application Specific Integrated Circuits”), CPU (a Central Processing Unit), a micro processing unit (MPU), conventional circuitry and/or combinations thereof which are configured or programmed to perform the disclosed functionality. Processors can be considered processing circuitry or circuitry as they include transistors and other circuitry therein. The processor may be a programmed processor which executes a program stored in a memory. In the disclosure, the circuitry, units, or means can be hardware that carry out or are programmed to perform the recited functionality. The hardware may be any hardware disclosed herein or otherwise known which is programmed or configured to carry out the recited functionality. When the hardware is a processor which may be considered a type of circuitry, the circuitry, means, or units can be a combination of hardware and software, the software being used to configure the hardware and/or processor. 
     INDUSTRIAL APPLICABILITY 
     As noted above, the present disclosure relates to work machines, and more particularly to construction machines equipped with a tilt rotator and a quick coupler, and systems, assemblies, and methods thereof. 
       FIG.  6    is a flowchart of a method of controlling a tilt rotator  40  to a correct position before attachment/detachment of the tool  15  from the quick coupler  50  according to one or more embodiments of the disclosed subject matter. 
     The process of controlling the tilt rotator  40  to the correct position may be initiated by the operator of the work machine  1  via the input unit  82 , for instance, at end of certain work by the tool  15  at the work site and a replacement of the tool may be needed for next work. Alternatively, the process of controlling the tilt rotator  40  to the correct position may be initiated by the operator of the work machine  1  via the input unit  82 , for instance, at beginning of transportation of the work machine  1 . For instance, as one embodiment, the operator of the work machine  1  may input “command of coupler detachment/attachment” may be input from the operator of the work machine  1  by the switch  104  on the operator interface  103 . 
     As shown in  FIG.  6   , the controller  88  may determine whether the tilt rotator  40  is attached to the work machine  1  (S1). In step S1, for example, the controller  88  may detect whether the tilt rotator  40  is attached to the work machine  1  by the sensor unit  87  as shown in  FIG.  5   . The controller  88  may start the step S1 in response to an instruction input from the operator via the input unit  82 , which can instruct or command to start attachment or detachment of the tool  15  to or from the quick coupler  50 . 
     Next, in the case where the determination of step S1 is YES, the controller  88  may detect the rotation angle  73  of the tilt rotator  40  (S2). More specifically, the controller  88  may start the detection of the rotation angle  73  of the tilt rotator  40  when the controller  88  receives input from the operator via the input unit  82 . For example, the controller  88  may detect the rotation angle  73  of the tilt rotator  40  by the sensor unit  87  as shown in  FIG.  5   . 
     On the other hand, in the case where the determination of step S1 is NO, i.e., the tilt rotator  40  is not attached to the work machine  1  by the sensor unit  87  as shown in  FIG.  5   , the processing may move on to step S8 of the processing shown in  FIG.  7   . Embodiments of the disclosed subject matter may include or be limited to only some or all of the operations of  FIG.  6   . 
     Next, the controller  88  can determine whether the tilt rotator  40  faces the front of the work machine  1  in the correct position, based on the detected rotation angle of the tilt rotator  40  (S3). In step S3, for example, the controller  88  may determine that the tilt rotator  40  faces the front of the work machine  1  in the correct position in the case where the detected rotation angle  73  of the tilt rotator  40  by the sensor unit  87  is equal to or less than a predetermined threshold (e.g., zero), as shown in  FIG.  3 A . Alternatively, as described above with  FIG.  3 B , the rotation angle  73  may be defined as the angle rotated from a plane which may be orthogonal to a forward running direction of the work machine  1 , or a plane may be perpendicular to the boom  16  of the work machine  1 , in the top plan view of the work machine  1 . 
     Next, in the case where the determination of step S3 is NO, the controller  88  may output instruction of rotation of the tilt rotator  40  to the operator of the work machine  1  (S4). More specifically, the controller  88  may output guidance information or a message which indicates to perform rotation operation of the tilt rotator  40  to the operator, via the display unit  85 , such as the monitor. Optionally or alternatively, the controller  88  may output the guidance information or the message which indicates to perform rotation operation of the tilt rotator  40  to the operator, via the audio unit  86 , such as the speaker. 
     On the other hand, in the case where the determination of step S3 is YES, the processing may move on to step S8 of the processing shown in  FIG.  7   . 
     Optionally, in addition to detection of the rotation angle  73 , the controller  88  may detect the tilt angle  76  of the tilt rotator  40  and may confirm that the tilt rotator  40  is not tilted as shown in  FIG.  4 A . More specifically, after the determination of step S3 (YES) and before step S8 shown in  FIG.  7   , the controller  88  may detect the tilt angle  76  of the tilt rotator  40  by the sensor unit  87  and determine whether the tilt rotator  40  is positioned in the correct position with respect to the tilt angle  76 . For example, the tilt rotator  40  may be determined as to be in the correct position in a case where the detected tilt angle  76  of the tilt rotator  40  is equal to or less than a predetermined threshold (e.g., zero), such as shown in  FIG.  4 A . After determination of the tilt angle  76 , the processing may move on to step S8 of the processing shown in  FIG.  7   . 
     Subsequently to step S4, in response to input of the rotation operation of the tilt rotator  40  provided by the operator via the input unit  82 , the controller  88  may monitor the rotation operation of the tilt rotator  40  (S5). In step S5, the controller  88  may also detect the rotation angle  73  of the tilt rotator  40  continuously. Optionally, the controller  88  may control to display, on the display unit  85 , virtual movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15  in 3D space in synchronization with real-time movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15 , during the rotation operation of the tilt rotator  40  provided by the operator via the input unit  82 . 
     Next, the controller  88  may determine whether the tilt rotator  40  faces the front of the work machine  1  in the correct position, based on the detected rotation angle  73  of the tilt rotator  40  (S6). In step S6, for example, the controller  88  may determine that the tilt rotator  40  faces the front of the work machine  1  in the correct position in the case where the monitored rotation angle  73  of the tilt rotator  40  by the sensor unit  87  is equal to or less than a predetermined threshold (e.g., zero), as shown in  FIG.  3 A . Alternatively, as described above with  FIG.  3 B , the rotation angle  73  may be defined as the angle rotated from a plane which may be orthogonal to a forward running direction of the work machine  1 , or a plane may be perpendicular to the boom  16  of the work machine  1 , in the top plan view of the work machine  1 . 
     Next, in the case where the determination of step S6 is YES, the controller  88  may automatically stop the rotation operation of the tilt rotator  40  (S7). For example, the controller  88  may automatically control hydraulic system of the tilt rotator  40  to stop the rotation operation of the tilt rotator  40  without input indicating stop instruction from the operator via the input unit  82 . In the embodiment, alternatively or optionally, the controller  88  may ignore instruction input or commands, from the operator, of further rotation operation of the tilt rotator  40 , or may disable the further rotation operation of the tilt rotator  40 . 
     As described above, generally, to stop the rotation operation of the tilt rotator  40  in the correct position by the operator with manual maneuvering input may not be accurate. Therefore, in this embodiment, the controller  88  may perform the step S7 instead of the operator to improve accuracy of the operation and safety of the work machine  1 . 
     On the other hand, in the case where the determination of step S6 is NO, the processing may return to step S4 and continue the processing shown in steps S5 and S6 until the determination of step S6 turns YES. 
     Optionally or alternatively, in a case that the sensor unit  87  detects an error during detection of the rotation angle  73  and/or the tilt angle  76  shown in  FIG.  6   , the controller  88  may terminate the processing for safety of the work machine  1 . 
       FIG.  7    is a flowchart of controlling rollup operation of the tool  15  for attachment/detachment of the quick coupler  50  according to one or more embodiments of the disclosed subject matter. The processing shown in  FIG.  7    may be performed subsequently to the processing of stop of the rotation operation of the tilt rotator  40  (S7) described with reference to  FIG.  6   . 
     As shown in  FIG.  7   , the controller  88  may output instruction of rollup of the tool  15  to the operator of the work machine  1  (S8). More specifically, in step S8, the controller  88  may output guidance information or a message which indicates to perform rollup operation of the tool  15  to the operator, via the display unit  85 , such as the monitor. Optionally or alternatively, the controller  88  may output the guidance information or the message which indicates to perform rollup operation of the tool  15  to the operator, via the audio unit  86 , such as the speaker. 
     Subsequently to step S8, in response to input of the rollup operation of the tool  15  provided by the operator via the input unit  82 , the controller  88  may monitor the rollup operation (S9). In step S9, the controller  88  may also detect position of the tool  15  continuously. Optionally, the controller  88  may control to display, on the display unit  85 , virtual movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15  in 3D space in synchronization with real-time movements of the arm arrangement  30 , the coupling arrangement  60  and the tool  15 , during the rollup operation provided by the operator via the input unit  82 . 
     Next, the controller  88  may determine whether the tool  15  is in a final position (S10). For instances, in the case where the tool  15  is a bucket, the controller  88  may detect a position of the bucket and determine that the tool is in the final position (“rolled up”) when the state of the bucket is “bucket curl” and “bucket cylinder relief” in step S10. Optionally or alternatively, the controller  88  may determine that the tool  15  is in the final position when the controller receives input from the operator via the input unit  82 . 
     In the case where the determination of step S10 is NO, the processing may return to step S8 and continue the processing shown in steps S9 and S10 until the determination of step S10 turns YES. 
     Next, in the case where the determination of step S10 is YES, the controller  88  may perform unlocking of the quick coupler  50  (S11). By unlocking the quick coupler  50 , a state of the quick coupler  50  may be transited to the unlock state from the lock state, and the tool  15  can be decoupled from the quick coupler  50  and replaceable by the operator. More specifically, the controller  88  may control the at least one locking actuator of the quick coupler  50 , so that the tool  15  can be decoupled from the quick coupler  50  in the unlock state. 
     Next, the controller  88  may output guidance information or a message which indicates the unlock state of the quick coupler  50  to the operator (S12) and the processing may end. For instance, in step S12, the controller  88  may output the guidance information or the message which indicates the unlock state of the quick coupler  50  to the operator via the display unit  85 , such as the monitor. Optionally or alternatively, the controller  88  may output the guidance information or the message which indicates the unlock state of the quick coupler  50  to the operator, via the audio unit  86 , such as the speaker. 
     As a result, the operator can safely detach the tool  15  from the quick coupler  50  and/or attach new tool to the quick coupler  50  after the processing shown in  FIGS.  6  and  7   . 
     It is noted that embodiments of the disclosed subject matter are not limited to the specific arrangement of the processing steps as shown in  FIGS.  6  and  7   . For instance, embodiments of the disclosed subject matter can add more processing steps to control the tilt rotator  40  and the quick coupler  50  of the work machine  1 . 
     Optionally or alternatively, in a case that the sensor unit  87  can detect an error during detection of the rotation angle  73 , the controller  88  may skip the steps S2 to S10 and perform unlock the quick coupler  50  as shown in step S11. In that case, subsequently to step S11, the controller  88  may output an error message indicating the fault in addition to the guidance information or the message which indicates the unlock state of the quick coupler  50  to the operator in step S12. 
     Optionally or alternatively, in a case that adjustment of a position of the tool  15  may be required after step S12, the tilt rotator can be rotatable and/or tiltable in a low speed mode. Embodiments of the disclosed subject matter may include or be limited to only some or all of the operations of  FIG.  7   . 
     Thus, according to embodiments of the disclosed subject matter, a work machine can comprise a tilt rotator to control rotation of a tool about a rotational axis and to control tilt of the tool about a tilt axis, a coupler to couple and decouple the tool to/from the tilt rotator, a display to output information to an operator of the work machine, an operator interface to receive input from the operator, and processing circuitry. The processing circuitry is configured to output, on the display, a rotation instruction for the operator to initiate a rotation operation of the tilt rotator, in a case that the tilt rotator is determined to be in an incorrect position based on a rotation angle of the tilt rotator about the rotational axis, stop the rotation operation of the tilt rotator under a condition that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator about the rotational axis, the rotation operation being initiated by a rotation input via the operator interface, output, on the display, a rollup instruction for the tool to initiate a rollup operation. 
     The work machine can detect the rotation angle of the tilt rotator in response to instruction of detachment of the tool from the coupler, via the operator interface. Optionally, the operator interface may be mounted on a joystick of the work machine. 
     Moreover, the work machine can determine that the tilt rotator is in the correct position when the rotation angle of the tilt rotator is equal or less than a predetermined threshold (e.g., zero). 
     Here, the rotation angle may be an angle between a face of the tool and a front surface of a body of the work machine in a top plan view of the work machine. 
     Furthermore, the work machine can determine that the tilt rotator is in the correct position when the face of the tool and the front surface of the body of the work machine are arranged in parallel in the top plan view of the work machine. 
     Optionally, the work machine can detect a tilt angle of the tilt rotator in advance to detecting the rotation angle of the tilt rotator, and control the tilt angle of the tilt rotator to be less than a predetermined threshold (e.g., zero). The tilt angle may be an angle of a top surface of the tool from a horizontal plane in a front view of the work machine. 
     Optionally, the work machine can display, on the display, virtual movements of the tilt rotator and the tool in 3D space in synchronization with real-time movements of the tilt rotator and the tool during the rotation operation. 
     Optionally, the work machine can display, on the display, virtual movements of the tilt rotator and the tool in 3D space in synchronization with real-time movements of the tilt rotator and the tool during the rollup operation. 
     Optionally, the work machine can detect an end of the rollup operation of the tool and output, on the display, information of an unlock state of the coupler which indicates that the tool is detachable from the coupler. 
     With these features, the work machine can guide the operator of the work machine to initiate rotation operation and rollup operation at an appropriate point respectively, and control to stop the rotation operation automatically. Thus, embodiments of the disclosed subject matter can increase safety and work efficiency of the work machine. 
     According to the embodiments, it is possible to control a series of processing of rotation operation of the tilt rotator and rollup operation of the tool by guiding the operator&#39;s operation appropriately, in addition to automatically performed operation. 
     In another aspect, a method for a work machine is disclosed or implemented. The method can comprise detecting a rotation angle of a tilt rotator, the tilt rotator controlling rotation of a tool about a rotational axis and controlling tilt of the tool about a tilt axis; outputting, on the display, a rotation instruction for the operator to initiate a rotation operation of the tilt rotator, in a case that the tilt rotator is determined to be in an incorrect position based on a rotation angle of the tilt rotator about the rotational axis; and stopping the rotation operation of the tilt rotator under a condition that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator about the rotational axis, the rotation operation being initiated by a rotation input via the operator interface. 
     And in another aspect a control system is disclosed or provided. The control system can comprise circuitry configured to detect a rotation angle of a tilt rotator, the tilt rotator controlling rotation of a tool about a rotational axis and controlling tilt of the tool about a tilt axis, output rotation instruction of the tilt rotator on a display, in a case that the tilt rotator is determined to be in an incorrect position based on the rotation angle of the tilt rotator, detect rotation operation of the tilt rotator, in response to a rotation input via an operator interface, automatically stop the rotation operation of the tilt rotator in a case that the tilt rotator is determined to be in a correct position based on the rotation angle of the tilt rotator, and output rollup instruction of the tool on the display. 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, assemblies, systems, and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.