SWING CONTROL OF A CONSTRUCTION MACHINE

Technical Field

The disclosure relates to a method of providing swing control of a construction machine and a construction machine configured to provide swing control.

Background

Construction machines can be used to carry out a number of tasks on a worksite. Examples include excavating and grading profiles. Such tasks may involve repetitive actions, for example swinging an arm and excavator bucket of the construction machine to and fro from an excavation location, where the excavator bucket is filled, and a disposal location, where the excavator bucket is emptied. While repetitive the task can involve high levels of operator skill to ensure efficient, safe and accurate operation. Summary of the Disclosure

The present disclosure provides a method of providing swing control of a construction machine, the construction machine being of a type comprising:

- a worktool attached to a rotatable portion of the construction machine, the rotatable portion being rotatable about a swing axis;

- a controller configured to receive operational inputs input by an operator via a control interface and transmit said operational inputs to one or more control systems of the construction machine; and

- a graphical user interface;

the method comprising the steps of:

a) the controller displaying to the operator one or more lines providing longitudinal and latitudinal information of a worksite, the lines being displayed on the graphical user interface; b) the operator selecting one of the one or more lines using the graphical user interface;

c) the operator inputting operational inputs via the control interface requesting swing of the worktool about the swing axis;

d) the controller operating to swing the worktool about the swing axis using the one or more control systems in response to the operational inputs; and

e) the controller further operating to automatically stop the swing of the worktool about the swing axis when the worktool reaches a predefined angular orientation relative to the selected line.

The present disclosure further provides a construction machine comprising:

- a rotatable portion that is rotatable about a swing axis;

- a worktool mount for receiving a worktool, the worktool mount being attached to the rotatable portion;

- a control interface;

- one or more control systems for rotating the rotatable portion about the swing axis;

- a controller configured to receive operational inputs input by an operator via the control interface and transmit said operational inputs to the one or more control systems; and

- a graphical user interface;

wherein the controller is further configured:

a) to display to the operator one or more lines providing longitudinal and latitudinal information of a worksite, the lines being displayed on the graphical user interface;

b) to facilitate selection by the operator of one of the one or more lines using the graphical user interface;

c) to receive operational inputs from the control interface requesting swing of the worktool mount about the swing axis; d) to command swing of the worktool mount about the swing axis using the one or more control systems in response to the operational inputs; and e) to automatically stop the swing of the worktool mount about the swing axis when the worktool mount or a worktool mounted in use to the worktool mount reaches a predefined angular orientation relative to the selected line.

Brief Description Of The Drawings

Specific embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

Figure 1 shows a schematic illustration of a construction machine according to the present disclosure;

Figure 2 is a schematic illustration of a control architecture of the construction machine of Figure 1;

Figure 3 is a schematic illustration of a graphical user interface of the construction machine of Figure 1 ;

Figure 4 is another schematic illustration of the graphical user interface of Figure 3; and

Figure 5 is a flow chart of method steps implemented by the construction machine of Figure 1. Detailed Description

As illustrated schematically in Figure 1, there is provided a construction machine 10 which has a rotatable portion that is rotatable about a swing axis 60. The rotatable portion may be a body 11 rotationally mounted on a drive portion 12 that may comprise tracks or wheels for ground propulsion. The rotational portion may be a portion of the body 11 or the body 11 as a whole. The rotational portion may be a rotatable element provided on a body or other part of the construction machine 10 that is not itself rotatable relative to the drive portion 12. Rotational mounting allows rotation about the swing axis 60. The swing axis 60 may project normal to ground on which the drive portion 12 rests. The construction machine 10 may be, by way of example only, an excavator, a backhoe loader, a mining shovel, a material handler, or a motor grader.

The construction machine is also provided with a worktool mount 18 which may be configured to receive a worktool 19. The worktool mount 18 may be attached to the body 11 by an arm 14. The arm 14 may be, or may form a part of, the rotatable portion.

The worktool 19 may be, by way of example only, a bucket, a blade, a shovel, an auger, a drill, or a compactor. The worktool 19 may have one or more side cutting faces 21 and one or more front cutting faces/edges 22 which may be perpendicular to each other. For example, when the worktool 19 is a bucket the bucket may have two parallel side cutting faces 21 joined together by a curved rear face that may terminate at a distal point in a front cutting edge 22. The front cutting edge 22 may be perpendicular to the side cutting faces 21.

The arm 14 may comprise a first section 15 and a second section 16 which may be pivotally connected to one another by a first pivot 17. A distal end of the first section 15 and a proximal end of the second section 16 may be coupled by the first pivot 17. A proximal end of the first section 15 may be pivotally connected to the body 11 via a second pivot (not shown). A distal end of the second section 16 may comprise, or be coupled to, the worktool mount 18.

An axis of the first pivot 17 may be parallel to an axis of the second pivot. The axis of the first pivot 17 and the axis of the second pivot may be horizontal when the ground on which the drive portion 12 rests is horizontal.

A mechanism for moving the arm 14 and or the worktool 19 may be provided. Hydraulic actuators 23 may be provided for this function. The hydraulic actuators 23 may allow the arm 14 and or the worktool 19 to be swung about the swing axis 60. The hydraulic actuators 23 may allow the worktool 19 to be moved towards or away from the body 11 and may allow the arm 14 and or the worktool 19 to be raised and lowered relative to the ground level.

The hydraulic actuators 23 may permit one or more of: rotation of the first section 15 relative to the body 11 about one or more axes; rotation of the second section 16 relative to the first section 15 about one or more axes; rotation of the worktool 19 relative to the second section 16 about one or more axes.

The body 11 may comprise a cab 13 from which an operator may control both ground propulsion of the construction machine 10 and movement of the worktool 19 relative to the body 11.

The construction machine 10 may be provided with a location sensor for determining longitudinal and latitudinal information of the

construction machine 10. The construction machine 10 may also have a rotational posture sensor for determining rotational posture information of the construction machine 10, for example the rotational posture of the body 11, the arm 14 and or the worktool 19. The location sensor and the rotational posture sensor may be separate or may be a combined sensor(s). In the illustrated example the location sensor and the rotational posture sensor comprise one, two or more Global Navigation Satellite System (GNSS) sensors 24 mounted to the body 11. The GNSS sensors 24 may be, for example, GPS, Glonass, Beidou or Galileo system sensors. One, two or more of the GNSS sensors 24 may be used in combination with other rotational and or heading sensors provided on the construction machine 10.

As illustrated schematically in Figure 2, the construction machine 10 further comprises a control interface 32, one or more control systems 34 for rotating the body 11 and or the arm 14 about the swing axis 60, a graphical user interface (GUI) 31, and a controller 30. The GUI 31 may be provided in the cab 13 to permit operation of the GUI 31 by the operator at the same time as operating other controls of the construction machine 10.

The controller 30 is configured to receive operational inputs input by an operator via the control interface 32 and transmit said operational inputs to the one or more control systems 34.

The controller 30 may comprise hardware and/or software. The controller 30 may comprise a control unit or may be a computer program running on a dedicated or shared computing resource. The controller 30 may comprise a single unit or may be composed of a plurality of sub-units that are operatively connected. The controller 30 may be located on one processing resource or may be distributed across spatially separate processing resources. The controller 30 may comprise a microcontroller, one or more processors (such as one or more microprocessors), memory, configurable logic, firmware, etc.

The controller 30 may also be configured to receive location and or posture information 35. The location and or posture information 35 may be provided to the controller 30 by the GNSS sensors 24.

The control interface 32 may include one or more of: a control lever, a joystick, a button, a switch, a wheel, a yoke, a pedal, a keyboard, a touchscreen, and a microphone.

The control interface 32 may include, or be operatively connected with, a swing override commander 36, the function of which will be described below.

The control systems 34 may comprise the one or more hydraulic actuators 23 which may be controlled to move the first section 15 and the second section 16 of the arm 14 and the worktool 19. The control systems 34 may also comprise one or more motors or hydraulic actuators for driving rotation of the body 11 about the drive portion 12. The control systems 34 may further comprise one more sensors providing positional feedback of the rotatable portion of the body 11, arm 14 and or worktool 19 to the controller 30 - for example angle sensors, accelerometers, electro-optical sensors.

An example of the GUI 31 is illustrated schematically in Figures 3 and 4. The GUI 31 may comprise a display panel which may be a touchscreen 40. Alongside the touchscreen 40 there may be provided a control panel 41 containing a plurality of hardware buttons 42, e.g. physical buttons, switches, dials, etc.

The touchscreen 40 may be divided into a plurality of functional zones. One functional zone may be a plurality of buttons 43 shown on the right hand side of the touchscreen 40. The buttons 43 may be icons that are touch sensitive. One functional zone may be an information panel 44 shown at a bottom of the touchscreen 40. One functional zone may be a line selection zone 45 that is shown to the top-left of the touchscreen 40. The size and relative positions as well as the number of functional zones may be varied.

The buttons 43 may provide access to menu options for navigating through functional and display options of the GUI 31.

The information panel 44 may display to the operator information such as the current location and or posture of the construction machine 10.

The line selection zone 45 may be used to display to the operator mapping information of a worksite in which the construction machine 10 is located.

The controller 30 is configured to display to the operator one or more lines 50 providing longitudinal and latitudinal information of the worksite, the lines being displayed on the GUI 31.

The lines 50 may be straight and or curved.

The lines 50 provide longitudinal and latitudinal information but preferably do not contain height information i.e. the lines 50 may be

representations of lines of the worksite when viewed from above in plan view.

The lines 50 may represent current features of the worksite or may represent target features of the worksite. Alternatively, the lines 50 may represent a target excavation line(s) that the operator is to dig along.

The lines 50 may be 2D lines, 3D lines and or lines formed by two surfaces joining (also referred to as“breaklines”).

The lines 50 may be displayed in the line selection zone 45. A machine icon 53 may be displayed illustrating the location of the construction machine 10 within the portion of the worksite displayed in the line selection zone 45 of the GUI 31. The rotational orientation of the machine icon 53 may be varied by the controller 30 to convey information to the operator regarding the current swing posture of the construction machine 10 and or arm 14 and or worktool 19 relative to the lines 50.

At least some of the lines are selectable by the operator using the GUI 31. Normally one line may be selected at one time. Selection may be by manually touching the required line 50 on the touchscreen 40. In Figure 3 one of the lines 50 (in this example a 2D line) has been selected and is shown emboldened and represents a selected line 51.

The GUI 31 may optionally display a perpendicular guide line 52 emanating from the selected line 51 as an operational guide for the operator.

The controller 30 is further configured to receive operational inputs from the control interface 32 requesting swing of the worktool mount 18 about the swing axis 60 and to command swing of the worktool mount 18 about the swing axis 60 using the one or more control systems 34 in response to the operational inputs.

The controller 30 is further configured to automatically stop the swing of the worktool mount 18 about the swing axis 60 when the worktool mount 18 or the worktool 19 mounted in use to the worktool mount 18 reaches a predefined angular orientation relative to the selected line 51.

The predefined angular orientation may be such that a cutting face of the worktool 19 is at a predefined angle to the selected line 51 as measured in a longitudinal-latitudinal plane.

The predefined angle may be 90 degrees when the cutting face is a side cutting face 21 of the worktool 19 or wherein the predefined angle may be 0 degrees when the cutting face is the front face or front cutting edge 22 of the worktool 19.

Other predefined angles may be selected. The controller 30 may have a default value for the predetermined angle. The predetermined angle may be selectable by the operator by making inputs on the GUI 31.

The controller may utilise locational and or rotational posture information to automatically stop the swing of the worktool mount 18 about the swing axis 60 at the desired point. This information may be derived by the controller 30 from the GNSS sensors 24.

The swing override commander 36 may be used to swing the worktool mount 18 past the predefined angular orientation relative to the selected line 51. Where the control interface 32 comprises a control lever the swing override commander 36 may comprise that control level and issuing a swing override command may comprise moving the control lever from a first swing position back to a neutral position and then returning the control lever to the first swing position. Alternatively, the swing override commander 36 may comprise a button and the swing override command may comprise operating the button.

Figure 5 illustrates an example work flow for a method of providing swing control of the construction machine 10 of the present disclosure.

In step 100 the controller displays to the operator one or more lines 50 providing longitudinal and latitudinal information of a worksite, the lines 50 being displayed on the GUI 31. The lines 50 may be 2D lines, 3D lines and or lines formed by two surfaces joining. The one or more lines 50 may be displayed in the line selection zone 45 of the touchscreen 40.

In step 110 the operator selects one of the one or more lines 50 using the GUI 31. The chosen line selected by the operator may be called the selected line 51. The selected line 51 may be given a distinct appearance in the line selection zone 45. For example, the selected line 51 may be shown in a different colour from the other lines 50 and or may be emboldened and or may flash. The operator may select the selected line 51 by touching the touchscreen 40 with a finger, or by using an input stylus or a connected input device for example a mouse or trackball operatively connected to the controller 30.

In step 120 the operator inputs operational inputs via the control interface 32 requesting swing of the worktool 19 about the swing axis 60. For example the operator may push a control lever to the left from a neutral position to swing the worktool 19 to the left and likewise push the control lever to the right from the neutral position to swing the worktool 19 to the right.

In step 130 the controller 30 operates to swing the worktool 19 about the swing axis 60 using the one or more control systems 34 in response to the operational inputs. For example the controller 30 may operate to command the hydraulic actuators 23 and or motor to rotate the rotatable portion of the body 11 about the drive portion 12. In addition or alternatively, the controller 30 may operate to command the hydraulic actuators to swing the arm 14 and or the worktool 19 relative to the body 11 and or drive portion 12. In step 140 the controller 30 further operates to automatically stop the swing of the worktool 19 about the swing axis 60 when the worktool 19 reaches a predefined angular orientation relative to the selected line 51. The controller 30 may receive locational and posture information from the one, two or more GNSS sensors 24 (and optionally one or more rotational and or heading sensors) and use this to determine when to stop movement of the worktool 19 at the correct point. For example, the controller 30 may determine longitudinal and latitudinal information of the construction machine 10 from a location sensor and rotational posture information of the construction machine 10 from a rotational posture sensor.

The predefined angular orientation may be such that a cutting face of the worktool is at a predefined angle to the selected line as measured in a longitudinal-latitudinal plane.

The predefined angle may be 90 degrees when the cutting face is the side face 21 of the worktool 19, for example the side of an excavator bucket. The predefined angle may be 0 degrees when the cutting face is the front cutting edge 22 of the worktool 19, for example the front edge of an excavator bucket. Other angles than 0 or 90 degrees may be used as the predefined angle. The controller 30 may have a default value for the predefined angle, for example 90 degrees. The operator may enter a different angle for the predefined angle using the GUI 31.

In optional step 150 the operator may input a swing override command via the control interface 32 to swing the worktool 19 past the predefined angular orientation relative to the selected line 51 The swing override command may be input using the control lever or a dedicated button or switch.

The swing override command may comprise moving the control lever from a first swing position back to a neutral position and then returning the control lever to the first swing position. An example of this would be moving the control lever to the left to swing the worktool 19 to the left until it reaches and stops at the predefined angle to the selected line 51, then returning the control lever back to the neutral position and finally moving the control lever again to the left to swing the worktool 19 further to the left‘through’ the predefined angle to the selected line 51.

Industrial Applicability

The present disclosure finds application in providing construction machines where a worktool may be swung about a swing axis with a high degree of accuracy in a repeatable manner. The present disclosure may allow increased operator efficiency by efficiently stopping the swing of the worktool at the right point, for example when the worktool is being used for grading or excavating slopes or profiles. Use of the controller to automatically stop the worktool at the predefined angle to the selected line may save operator effort, time, fuel and reduce wear on components of the construction machine 10. In particular using the controller 30 to return the worktool to the correct point eveiy time can lead to a reduction in the time taken to carry out this repetitive movement.

The present disclosure may also allow the worktool to be returned to the right point relative to the selected line even where there is movement of the drive portion of the construction machine during or between swing movements. This may increase efficient excavation or grading along a required line of construction.